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qfGT-8OoznFJIrIe	Contemporary Families in the US: An Equity Lens 2e	5.4 Culture and Families Monica Olvera and Elizabeth Torres As discussed in Chapter 2, culture, broadly defined, is the set of beliefs, values, symbols, means of communication, religion, logics, rituals, fashions, etiquette, foods, and art that unite a particular society. Cultural elements are learned behaviors; children learn them while growing up in a particular culture as older members teach them how to live. As such, culture is passed down from one generation to the next. Culture is intertwined with both ethnicity, religion, and spirituality. Ethnicity refers to the shared social, cultural, and historical experiences stemming from common national, ancestral, or regional backgrounds that make subgroups of a population different from one another. Similarly, an ethnic group is a subgroup of a population with a set of shared social, cultural, and historical experiences; relatively distinctive beliefs, values, and behaviors and some sense of identity or belonging to the subgroup. Pan-ethnicity is the grouping together of multiple ethnicities and nationalities under a single label. For example, people in the United States with Vietnamese, Cambodian, Japanese, and Korean backgrounds could be grouped together under the pan-ethnic label Asian American. The United States has five pan-ethnic groups, including Native Americans, African Americans, Asian Americans, European Americans, and Latinos. The grouping together of multiple ethnicities or nationalities under one umbrella term can be helpful, but it can also be problematic—these groups may share geography, but they have differing values, beliefs, and rituals. In addition to ethnicity, other terms are used to refer to this aspect of cultures, such as majority and minoritized or marginalized cultures, dominant and nondominant cultures, or macro- and microcultures. Some groups relate to social identities based on regions (the South, the East Coast, urban, rural) or affiliation (street gangs, NASCAR fans, college students). Such groups are not necessarily distinct cultures but rather groups of people who share concerns and who might perceive similarities due to common interests or characteristics (Lustig & Koester, 2010). Religion is a collection of cultural systems, belief systems, and worldviews that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions, and sacred histories that are intended to give meaning to life or to explain the origin of life or the universe. People may affiliate with religions, beliefs, or a general sense of spirituality. In Focus: What Brings Us Together My whole family has such a close relationship and tight bond because we do a lot as a group, including working together. I would say that our religion and culture do play a big role in this. In our culture, food is a big thing, and we always work together to cook for the family. We are also always willing to help one another whenever one needs a hand, and that’s where religion comes in. Being Catholic, we are just always taught to be nice and respectful toward everyone, especially your family. Families maintain traditions, rituals, and routines that are heavily influenced by the cultural spaces that any kinship group occupies. But families are also made up of individuals, and while a kinship group may share a culture, individuals may embrace different cultures, ethnic identities, and religious or spiritual beliefs, which creates complexities in family life. For example, for immigrant and refugee families in the United States, religiosity can be a protective factor when adapting to another culture. Religiosity and spirituality, often integrated with one’s ethnic identity, rituals, and traditions, appear to play a significant role as protective factors in the immigrant paradox among Latino and Somali youth (Areba, 2015; Ruiz & Steffen, 2011). What happens when individuals within a family have differing beliefs? People who grew up in families where parents had different religions from one another report less overall religiosity (McPhail, 2019). Children may grow up with differing religious or spiritual beliefs from those of their parents. Especially in the case of children who identify as LGBTQIA+ within a family whose religious or moral beliefs negate these identities, children can experience dissonance and a lack of connection within their family. Belonging While there are many definitions and conceptualizations of belonging, one definition is when a person experiences a subjective feeling that they are an integral part of their surrounding systems, including their friends, family, school and work environments, communities, cultural groups, and physical places (Hagerty et al., 1992). The need for belonging, “to connect deeply with other people and secure places, to align with one’s cultural and subcultural identities, and to feel like one is a part of the systems around them,” is a very basic human need (Allen et al., 2021). Connection with others, physical safety, and well-being are inextricably linked and are crucial for survival (Boyd & Richardson, 2009). A greater sense of belonging is associated with positive psychosocial outcomes. The benefits and potential protective factors derived from a sense of belonging are especially potent for individuals who identify with marginalized or minoritized groups, including people who identify as sexually or gender diverse, people with disabilities, or those who experience mental health issues (Gardner et al., 2019; Harrist & Bradley, 2002; Rainey et al., 2018; Spencer et al., 2016; Steger & Kashdan, 2009). Among college students from minoritized communities, social belonging interventions are associated with positive impacts on academic and health outcomes (Walton & Cohen, 2011). Other positive effects include having a healthy sense of belonging, including more positive social relationships, academic achievement, occupational success, and better physical and mental health (Allen et al., 2018; Goodenow & Grady, 1993; Hagerty et al., 1992). In contrast to the benefits of feeling a sense of belonging, a lack of belonging has been linked to an increased risk for mental and physical health problems (Cacioppo et al., 2015). The health risks associated with social isolation can be the equivalent to smoking 15 cigarettes a day and are twice as harmful as obesity (Holt-Lunstad et al., 2015). Social isolation across the lifespan is associated with poor sleep quality, depression, cardiovascular difficulties, rapid cognitive decline, reduced immunity, increased risk for mental illness, lowered immune functioning, antisocial behavior, physical illness, and early mortality (Cacioppo & Hawkley, 2003; Cacioppo et al., 2011; Choenarom et al., 2005; Cornwell & Waite, 2009; Hawkley & Capitanio, 2015; Holt-Lunstad, 2018; Leary, 1990; Slavich et al., 2010; O’Donovan et al., 2010). Belonging can be fostered at the individual and social level. Figure 5.8 provides a framework for understanding and fostering belonging. A sense of belonging can be impacted by one’s competencies, opportunities, perceptions, and motivations (Allen et al., 2021). Competency refers to having a set of skills and abilities that are needed to connect and relate to others, develop a sense of identity, and ensure one’s behavior aligns with social norms and cultural values. Opportunities to belong come from the availability of groups, people, places, times, and spaces to connect with others in ways that allow belonging to occur. Individuals from isolated or rural areas, first- and second-generation immigrants, and refugees may experience circumstances that limit opportunities to foster belonging. The lack of opportunities for belonging was sharply felt during the COVID-19 pandemic when shelter-in-place orders and social distancing measures limited human interactions. But despite opportunities to connect in person, technologies such as gaming and social media quickly became more favored opportunities for connection, especially for youth, those who are shy, or people who experience social anxiety (Allen et al., 2014; Amichai-Hamburger et al., 2002; Davis, 2012; Moore & McElroy, 2012; Seabrook et al., 2016; Seidman, 2013). Motivations to belong consist of the need or desire to connect with others or the fundamental need to feel accepted, belong, and seek social interactions and connections (Leary & Kelly, 2009). Individuals have varying perceptions of belonging within their kinship groups and within chosen or assigned cultures. Perceptions of belonging are related to one’s subjective feelings and cognitions regarding their experiences and are informed by past experiences. A person’s negative perceptions of self or others, stereotypes, and negative experiences, such as feeling left out, can affect the desire to connect with others. Cultural Erasure and Cultural Persistence Cultural erasure is the practice of a dominant culture contributing to the erasure of a non-dominant or minoritized culture. An example of active cultural erasure would be that of Native American children being forced to attend residential boarding schools, where they might be punished for speaking their heritage language, forced to wear uniforms that were stripped of makers of their community and identity, and harshly mistreated, even to the point of starvation or being beaten (figure 5.9). The strategy of not allowing the children to speak their communities’ languages or learn and practice their communities’ traditions and rituals was an active cultural erasure. Passive cultural erasure could include the histories of communities not being included in historical textbooks or the passing of laws that prohibit people from wearing jewelry, hairstyles, clothing, or other items that are indicators of one’s cultural identity. Cultural persistence, then, is the very opposite of cultural erasure. Cultural persistence is when elements of culture (such as language, rituals, foodways, and traditions) persist despite efforts to blot out those cultural practices and identities. Among Black Caribbean immigrants, gatherings of family and friends called “liming” sessions reinforce family and cultural identities through storytelling (Brooks, 2013). Another example of cultural persistence is that of language revitalization programs among Indigenous communities, such as the Chinuk Wawa language program supported by Lane Community College (LCC) in Eugene, Oregon. This program consists of a collaboration between Lane Community College, the Confederated Tribes of Grand Ronde, and the Northwest Indian Language Institute of the University of Oregon (UO). This program, which has operated for nearly a decade, provides language classes for tribal members, LCC and UO students, and members of the Grand Ronde Community. Comprehension Self Check Licenses and Attributions for Culture and Families Open Content, Original “Culture and Families” and all subsections except those noted below by Monica Olvera. License: CC BY 4.0. “In Focus: What Brings Us Together” By Elizabeth Torres. License: CC BY-NC-ND 4.0. Figure 5.8 “Four Components of Belonging” designed by Monica Olvera and Michaela Willi Hooper. License: CC BY 4.0. Based on ideas from “Belonging: A Review of Conceptual Issues, an Integrative Framework, and Directions for Future Research” by K.-A. Allen, M. L. Kern, C. S. Rozek, D. M. McInerney, & G. M. Slavich in Australian Journal of Psychology. Open Content, Shared Previously The definition of culture in the first paragraph is from “Culture” in “Sociology” by Libre Texts. License: CC BY-SA. The definitions of ethnicity and ethnic groups in the second paragraph are from “Ethnicity and Religion” in “Social Justice Studies” by Libre Texts. License: CC BY-NC-SA. The definition of religion in the 5th paragraph is from” The Nature of Religion ” in “Sociology” by Libre Texts. License: CC BY-SA. Figure 5.7 “Photo“ by Jeswin Thomas on unsplash.com. License: Unsplash License. Figure 5.9 “Tom Torlino – Navajo” by Carlisle Indian School Digital Resource Center. License: CC BY-NC-SA. References Brooks, L. J. (2013). The Black survivors: Courage, strength, creativity and resilience in the cultural traditions of Black Caribbean immigrants. In J.D. Sinnott (Ed.) Positive Psychology (pp. 121-134). New York: Springer. Lustig, M., & Koester, J. (2010). Intercultural communication: interpersonal communication across cultures. J. Koester.–Boston: Pearson Education. What Census Calls Us. (2020, May 30). Pew Research Center. https://www.pewresearch.org/interactives/what-census-calls-us/ the shared meanings and shared experiences passed down over time by individuals in a group, such as beliefs, values, symbols, means of communication, religion, logics, rituals, fashions, etiquette, foods, and art that unite a particular society. the shared social, cultural, and historical experiences, stemming from common national, ancestral, or regional backgrounds, that make subgroups of a population different from one another. a subgroup of a population with a set of shared social, cultural, and historical experiences; relatively distinctive beliefs, values, and behaviors; and some sense of identity of belonging to the subgroup. the grouping together of multiple ethnicities and nationalities under a single label. can include the emotional significance of an action or way of being; the intention or reason for doing something; something that we create and feel; closely linked to motivation. the geographical location where a person was born and spent (at least) their early years in. the social structure that ties people together (whether by blood, marriage, legal processes, or other agreements) and includes family relationships. a sense of self that is derived from a sense of belonging to a group, a culture, and a particular setting. influenced by personal experiences and opinions. a socially constructed expression of a person’s sexual identity which influences the status, roles, and norms for their behavior. the visible or hidden and temporary or permanent conditions that create barriers or challenges in one’s life. the state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity. a state of mind characterized by emotional well-being, behavioral adjustment, relative freedom from anxiety and disabling symptoms, and a capacity to establish relationships and cope with the ordinary demands and stresses of life. a wide range of mental health disorders that affect your mood, thinking, and behavior. the practice of a dominant or hegemonic culture actively or passively contributing to the erasure, or disappearing, of a non-dominant or minoritized culture. a systematic investigation into a particular topic, examining materials, sources, and/or behaviors.	2,866	common-pile/pressbooks_filtered	https://openoregon.pressbooks.pub/contempfamilies2e/chapter/oo5-4/	pressbooks	pressbooks-0000.json.gz:42640	https://openoregon.pressbooks.pub/contempfamilies2e/chapter/oo5-4/
I8fITgNp_UCBSH2G	2.2: Visible and Near Infrared Optical Spectroscopic Sensors for Biosystems Engineering	2.2: Visible and Near Infrared Optical Spectroscopic Sensors for Biosystems Engineering Nathalie Gorretta University of Montpellier, INRAe and SupAgro Montpellier, France Aoife A. Gowen UCD School of Biosystems and Food Engineering University College Dublin, Ireland Variables Introduction Optical sensors are a broad class of devices for detecting light intensity. This can be a simple component for notifying when ambient light intensity rises above or falls below a prescribed level, or a highly sensitive device with the capacity to detect and quantify various properties of light such as intensity, frequency, wavelength, or polarization. Among these sensors, optical spectroscopic sensors, where light interaction with a sample is measured at many different wavelengths, are popular tools for the characterization of biological resources, since they facilitate comprehensive, non-invasive, and non-destructive monitoring. Optical sensors are widely used in the control and characterization of various biological environments, including food processing, agriculture, organic waste sorting, and digestate control. The theory of spectroscopy began in the 17th century. In 1666, Isaac Newton demonstrated that white light from the sun could be dispersed into a continuous series of colors (Thomas, 1991), coining the word spectrum to describe this phenomenon. Many other researchers then contributed to the development of this technique by showing, for example, that the sun’s radiation was not limited to the visible portion of the electromagnetic spectrum. William Herschel (1800) and Johann Wilhelm Ritter (1801) showed that the sun’s radiation extended into the infrared and ultraviolet, respectively. A major contribution by Joseph Fraunhofer in 1814 laid the foundations for quantitative spectrometry. He extended Newton’s discovery by observing that the sun’s spectrum was crossed by a large number of fine dark lines now known as Fraunhofer lines. He also developed an essential element of future spectrum measurement tools (spectrometers) known as the diffraction grating, an array of slits that disperses light. Despite these major advances, Fraunhofer could not give an explanation as to the origin of the spectral lines he had observed. It was only later, in the 1850s, that Gustav Kirchoff and Robert Bunsen showed that each atom and molecule has its own characteristic spectrum. Their achievements established spectroscopy as a scientific tool for probing atomic and molecular structure (Thomas, 1991; Bursey, 2017). Many terms are used to describe the measurement of electromagnetic energy at different wavelengths, such as spectroscopy, spectrometry, and spectrophotometry. The word spectroscopy originates from the combination of spectro (from the Latin word specere , meaning “to look at”) with scopy (from the Greek word skopia , meaning “to see”). Following the achievements of Newton, the term spectroscopy was first applied to describe the study of visible light dispersed by a prism as a function of its wavelength. The concept of spectroscopy was extended, during a lecture by Arthur Schuster in 1881 at the Royal Institution, to incorporate any interaction with radiative energy according to its wavelength or frequency (Schuster, 1911). Spectroscopy, then, can be summarized as the scientific study of the electromagnetic radiation emitted, absorbed, reflected, or scattered by atoms or molecules. Spectrometry or spectrophotometry is the quantitative measurement of the electromagnetic energy emitted, reflected, absorbed, or scattered by a material as a function of wavelength. The suffix “- photo” (originating from the Greek term phôs , meaning “light”) refers to visual observation, for example, printing on photographic film, projection on a screen, or the use of an observation scope, while the suffix “- metry” (from the Greek term metria , meaning the process of measuring) refers to the recording of a signal by a device (plotter or electronic recording). Spectroscopic data are typically represented by a spectrum, a plot of the response of interest (e.g. reflectance, transmittance) as a function of wavelength or frequency. The instrument used to obtain a spectrum is called a spectrometer or a spectrophotometer. The spectrum, representing the interaction of electromagnetic radiation with matter, can be analyzed to gain information on the identity, structure, and energy levels of atoms and molecules in a sample. Two major types of spectroscopy have been defined, atomic and molecular. Atomic spectroscopy refers to the study of electromagnetic radiation absorbed or emitted by atoms, whereas molecular spectroscopy refers to the study of the light absorbed or emitted by molecules. Molecular spectroscopy provides information about chemical functions and structure of matter while atomic spectroscopy gives information about elemental composition of a sample. This chapter focuses on molecular spectroscopy, particularly in the visible-near infrared wavelength region due to its relevance in biosystems engineering. Concepts Light and Matter Interaction Spectroscopy is based on the way electromagnetic energy interacts with matter. All light is classified as electromagnetic radiation consisting of alternating electric and magnetic fields and is described classically by a continuous sinusoidal wave-like motion of the electric and magnetic fields propagating transversally in space and time. Wave motion can be described by its wavelength $\lambda$ (nm), the distance between successive maxima or minima, or by its frequency ν (Hz), the number of oscillations of the field per second (Figure 2.2.1). Wavelength is related to the frequency via the speed of light c (3 × 10 8 m s −1 ) according to the relationship given in Equation 2.2.1. \[ \lambda = \frac{c}{v} \] Sometimes it is convenient to describe light in terms of units called “wavenumbers,” where the wavenumber is the number of waves in one centimeter. Thus, wavenumbers are frequently used to characterize infrared radiation. The wavenumber, $\bar{\nu}$ is formally defined as the inverse of the wavelength, $\lambda$ expressed in centimeters: \[ \bar{\nu}=\frac{1}{\lambda} \] The wavenumber is therefore directly proportional to frequency, ν: \[ v = c\bar{\nu} \] leading to the following conversion relationships: \[ \bar{\nu} (\text{cm}^{-1}) = \frac{10^{7}}{\lambda{\text{(nm)}}} \] \[ \lambda{\text{(nm)} = \frac{10^{7}}{\bar{\nu}(\text{cm}^{-1})}} \] The propagation of light is described by the theory of electromagnetic waves proposed by Christian Huygens in 1878 (Huygens, 1912). However, the interaction of light with matter (emission or absorption) also leads to the particle nature of light and electromagnetic waves as proposed by Planck and Einstein in the early 1900s. In this theory, light is considered to consist of particles called photons, moving at the speed c . Photons are “packets” of elementary energy, or quanta, that are exchanged during the absorption or emission of light by matter. \| Wavelength $\lambda$ \| Wavenumber $\bar{\nu}$ \| Relation \| \| \|---\|---\|---\|---\| \| Unit \| cm \| cm −1 \| $\bar{\nu}= \frac{1}{\lambda}$ \| \| nm \| cm −1 \| $\bar{\nu}= \frac{10^{7}}{\lambda}$ \| The energy of photons of light is directly proportional to its frequency, as described by the fundamental Planck relation (Equation 2.2.6). Thus, high energy radiation (such as X-rays) has high frequencies and short wavelengths and, inversely, low energy radiation (such as radio waves) has low frequencies and long wavelengths. \[ E =h\nu=\frac{hc}{\lambda}=hc\bar{\nu} \] where E = energy of photons of light (J) h = Plank’s constant = 6.62607004 × 10 −34 J·s ν = frequency (Hz) c = speed of light (3 ×10 8 m s −1 ) $\lambda$ = wavelength (m) The electromagnetic spectrum is the division of electromagnetic radiation according to its different components in terms of frequency, photon energy or associated wavelengths, as shown in Figure 2.2.2. The highest energy radiation corresponds to the γ-ray region of the spectrum. At the other end of the electromagnetic spectrum, radio frequencies have very low energy (Pavia et al., 2008). The visible region only makes up a small part of the electromagnetic spectrum and ranges from 400 to about 750 nm. The infrared (IR) spectral region is adjacent to the visible spectral region and extends from about 750 nm to about 5 × 10 6 nm. It can be further subdivided into the near-infrared region (NIR) from about 750 nm to 2,500 nm which contains the short wave-infrared (SWIR) from 1100–2500 nm, the mid-infrared (MIR) region from 2,500 nm to 5 × 10 4 nm, and the far-infrared (FIR) region from 5 × 10 4 nm to 5 × 10 6 nm (Osborne et al., 1993). When electromagnetic radiation collides with a molecule, the molecule’s electronic configuration is modified. This modification is related to the wavelength of the radiation and consequently to its energy. The interaction of a wave with matter, whatever its energy, is governed by the Bohr atomic model and derivative laws established by Bohr, Einstein, Planck, and De Broglie (Bohr, 1913; De Broguie, 1925). Atoms and molecules can only exist in certain quantified energy states. The energy exchanges between matter and radiation can, therefore, only be done by specific amounts of energy or quanta $ \Delta{E} =h\nu $. These energy exchanges can be carried out in three main ways (Figure 2.2.3): absorption, emission, or diffusion. In absorption spectroscopy, a photon is absorbed by a molecule, which undergoes a transition from a lower-energy state E i to a higher energy or excited state E j such that E j – E i = h ν. In emission spectroscopy, a photon can be emitted by a molecule that undergoes a transition from a higher energy state E j to a lower energy state E i such that E j – E i = h ν. In diffusion or scattering spectroscopy, a part of the radiation interacting with matter is scattered in many directions by the particles of the sample. If, after an interaction, the photon energy is not modified, the interaction is known as elastic . This corresponds to Rayleigh or elastic scattering, which maintains the frequency of the incident wave. When the photon takes or gives energy to the matter and undergoes a change in energy, the interaction is called inelastic , corresponding, respectively, to Stokes or anti-Stokes Raman scattering. Transitions between energy states are referred to as absorption or emission lines for absorption and emission spectroscopy, respectively. Absorption Spectrometry In absorption spectrometry, transitions between energy states are referred to as absorption lines . These absorption lines are typically classified by the nature of the electronic configuration change induced in the molecule (Sun, 2009): - • Rotation lines occur when the rotational state of a molecule is changed. They are typically found in the microwave spectral region ranging between 100 μm and 1 cm. - • Vibrational lines occur when the vibrational state of the molecule is changed. They are typically found in the IR, i.e., in the spectral range between 780 and 25,000 nm. Overtones and combinations of the fundamental vibrations in the IR are found in the NIR range (Figure 2.2.2). - • Electronic lines correspond to a change in the electronic state of a molecule (transitions of the energetic levels of valence orbitals). They are typically found in the ultraviolet (approx. 200–400 nm) and visible region (approx. 200–400 nm). In the visible region (350–800 nm), molecules such as carotenoids and chlorophylls absorb light due to their molecular structure. This visible spectral range is also used to evaluate color (for instance, of food or vegetation). In the ultraviolet spectral range, fluorescence and phosphorescence can be observed. While fluorescence and phosphorescence are both spontaneous emission of electromagnetic radiation, they differ in the way the excited molecule loses its energy after it has been irradiated. The glow of fluorescence stops right after the source of excitatory radiation is switched off, whereas for phosphorescence, an afterglow can last from fractions of a second to hours. The spectral ranges selected for measurement and analysis depend on the application and the materials to be characterized. Absorption spectroscopy in the visible and NIR is commonly used for the characterization of biological systems due to the many advantages associated with this wavelength range, including rapidity, non-invasivity, non-destructive measurement, and significant incident wave penetration. Moreover, the NIR range enables probing of molecules containing C-H, N-H, S-H, and O-H bonds, which are of particular interest for characterization of biological samples (Pasquini, 2018; 2003). In addition to the chemical characterization of materials, it is possible to quantify the concentration of certain molecules using the Beer-Lambert law, described in detail below. Beer-Lambert Law Incident radiation passing through a medium undergoes several changes, the extent of which depends on the physical and chemical properties of the medium. Typically, part of the incident beam is reflected, another part is absorbed and transformed into heat by interaction with the material, and the rest passes through the medium. Transmittance is defined as the ratio of the transmitted light intensity to the incident light intensity (Equation 2.2.7). Absorbance is defined as the logarithm of the inverse of the transmittance (Equation 2.2.8). Absorbance is a positive value, without units. Due to the inverse relationship between them, absorbance is greater when the transmitted light is low. \[ T= \frac{I}{I_{0}} \] \[ A=log(\frac{1}{T})=log(\frac{I_{0}}{I}) \] where T = transmittance I = transmitted light intensity I 0 = incident light intensity A = absorbance (unitless) The Beer-Lambert law (Equation 2.2.9) describes the linear relationship between absorbance and concentration of an absorbing species. At a given wavelength λ , absorbance A of a solution is directly proportional to its concentration ( C ) and to the length of the optical path ( b ), i.e., the distance over which light passes through the solution (Figure 2.2.4, Equation 2.2.9). When the concentration is expressed in moles per liter (mol L −1 ), the length of the optical path in centimeters (cm), the molar absorptivity or the molar extinction coefficient ε is expressed in L mol −1 cm −1 . Molar absorptivity is a measure of the probability of the electronic transition and depends on the wavelength but also on the solute responsible for absorption, the temperature and, to a lesser extent, the pressure. \[ A=\epsilon bC \] where A = absorbance (unitless) ε = molar absorptivity or molar extinction coefficient = Beer-Lambert proportionality constant (L mol −1 cm −1 ) b = path length of the sample (cm) C = concentration (mol L −1 ) Beer-Lambert Law Limitations Under certain circumstances, the linear relationship between the absorbance, the concentration, and the path length of light can break down due to chemical and instrumental factors. Causes of nonlinearity include the following: - • Deviation of absorptivity coefficient: The Beer-Lambert law is capable of describing the behavior of a solution containing a low concentration of an analyte. When analyte concentration is too high (typically >10 mM), electrostatic interactions between molecules close to each other result in deviations in absorptivity coefficients. - • High analyte concentrations can also alter the refractive index of the solution which in turn could affect the absorbance obtained. - • Scattering: Particulates in the sample can induce scattering of light. - • Fluorescence or phosphorescence of the sample. - • Non-monochromatic radiation due to instrumentation used. Non-linearity can be detected as deviations from linearity when the absorbance is plotted as a function of concentration (see example 1). This is usually overcome by reducing analyte concentration through sample dilution. Spectroscopic Measurements Spectrometers are optical instruments that detect and measure the intensity of light at different wavelengths. Different measurement modes are available, including transmission, reflection, and diffuse reflection (Figure 2.2.5). In transmission mode, the spectrometer captures the light transmitted through a sample, while in reflectance mode, the spectrometer captures the light reflected by the sample. In some situations, e.g., for light-diffusing samples such as powders, reflected light does not come solely from the front surface of the object; radiation that penetrates the material can reappear after scattering of reflection within the sample. These radiations are called diffuse reflection. Spectrometers share several common basic components, including a source of light energy, a means for isolating a narrow range of wavelengths (typically a dispersive element), and a detector. The dispersive element must allow light of different wavelengths to be separated (Figure 2.2.6). The light source is arguably the most important component of any spectrophotometer. The ideal source is a continuous one that contains radiation of uniform intensity over a large range of wavelengths. Other desirable properties are stability over time, long service life, and low cost. Quartz-tungsten halogen lamps are commonly used as light sources for the visible (Vis) and NIR regions, and deuterium lamps or high-powered light emitting diodes may be used for the ultraviolet region. The light produced by the light source is then focused and directed to the monochromater by an entrance slit. A grating diffraction element is then used to split the white light from the lamp into its components. The distance between the lines on gratings (“grating pitch”) is of the same order of magnitude as the wavelength of the light to be analyzed. The separated wavelengths then propagate towards the sample compartment through the exit slit. Depending on the technology used for the detector, the sample can be positioned before or after the monochromater. For simplicity, this chapter describes a positioning of the sample after the monochromater; the entire operation described above is valid regardless of the positioning of the sample. In some spectrometers, an interferometer (e.g. Fabry-Pérot or Fourier-transform interferometer for UV and IR spectral range, respectively) is used instead of a diffraction grating to obtain spectral measurements. In this case, the initial beam light is split into two beams with different optical paths by using mirror arrangements. These two beams are then recombined before arriving at the detector. If the optical path lengths of the two beams do not differ by too much, an interference pattern is produced. A mathematical operation (Fourier transform) is then applied to the obtained interference pattern (interferogram) to produce a spectrum. Once the light beams have passed through the samples, they will continue to the detector or photodetector. A photodetector absorbs the optical energy and converts it into electrical energy. A photodetector is a multichannel detector and can be a photodiode array, a charge coupled device (CCD), or a complementary metal oxide semiconductor (CMOS) sensor. While photodetectors can be characterized in many different ways, the most important differentiator is the detector material. The two most common semiconductor materials used in Vis-NIR spectrometers are silicon (Si) and indium gallium arsenide (InGaAs). Spectral Imaging Spectral imaging is a technique that integrates conventional imaging and spectroscopy to obtain both spatial and spectral information from an object. Multispectral imaging usually refers to spectral images in which <10 spectral bands are collected, while hyperspectral imaging is the term used when >100 contiguous spectral bands are collected. The term spectral imaging is more general. Spectral images can be represented as three-dimensional blocks of data, comprising two spatial and one wavelength dimension. Two sensing modes are commonly used to acquire hyperspectral images, i.e., reflectance and transmission modes (Figure 2.2.7). The use of these modes depends on the objects to be characterized (e.g., transparent or opaque) and the properties to be determined (e.g. size, shape, chemical composition, presence of defects). In reflectance mode, the hyperspectral sensor and light are located on the same side of the object and the imaging system acquires the light reflected by the object. In this mode, the lighting system should be designed to avoid any specular reflection. Specular reflection occurs when a light source can be seen as a direct reflection on the surface of an object. It is characterized by an angle of reflection being equal to the angle of incidence of the incoming light source on the sample. Specular reflection appears as bright saturated spots on acquired images impacting their quality. In transmittance mode, the detector is located in the opposite side of the light source and captures the transmitted light through the sample. Applications Vegetation Monitoring in Agriculture The propagation of light through plant leaves is governed primarily by absorption and scattering interactions and is related to chemical and structural composition of the leaves. Spectral characteristics of radiation reflected, transmitted, or absorbed by leaves can thus provide a more thorough understanding of physiological responses to growth conditions and plant adaptations to the environment. Indeed, the biochemical components and physical structure of vegetation are related to its state of growth and health. For example, foliar pigments including chlorophyll a and b, carotenoids, and anthocyanins are strong absorbers in the Vis region and are abundant in healthy vegetation, causing plant reflectance spectra to be low in the Vis relative to NIR wavelength range (Asner, 1998; Ollinger, 2011) (Figure 2.2.8). Chlorophyll pigments absorb violet-blue and red light for photosynthesis, the process by which plants use sunlight to synthesize organic matter. Green light is not absorbed by photosynthesis and reflectance spectra of green vegetation in the visible range are maximum around 550 nm. This is why healthy leaves appear to be green. The red edge refers to the area of the sudden increase in the reflectance of green vegetation between 670 and 780 nm. The reflectance in the NIR plateau (800–1100 nm) is a region where biochemical absorptions are limited and is affected by the scattering of light within the leaf, the extent of which is related to the leaf’s internal structure. Reflectance in the short wave-IR (1100–2500 nm) is characterized by strong water absorption and minor absorptions of other foliar biochemical contents such as lignin, cellulose, starch, protein, and cellulose. Stress conditions on plants, such as drought and pathogens, will induce changes in reflectance in the Vis and NIR spectral domain due to degradation of the leaf structure and the change of the chemical composition of certain tissues. Consequently, by measuring crop reflectance in the Vis and NIR regions of the spectrum, spectrometric sensors are able to monitor and estimate crop yield and crop water requirements and to detect biotic or abiotic stresses on vegetation. Vegetation indices (VI), which are combinations of reflectance images at two or more wavelengths designed to highlight a particular property of vegetation, can then be calculated over these images to monitor vegetation changes or properties at different spatial scales. The normalized difference vegetation index (NDVI) (Rouse et al., 1974) is the ratio of the difference between NIR and red reflectance, divided by the sum of the two: \[ NDVI = \frac{R_{NIR}-R_{R}}{R_{NIR}+R_{R}} \] where R NIR = reflectance in the NIR spectral region (one wavelength selected over the 750–870 nm spectral range) and R R = reflectance in the red spectral region (one wavelength selected over 580–650 nm spectral range). Dividing by the sum of the two bands reduces variations in light over the field of view of the image. Thus, NDVI maintains a relatively constant value regardless of the overall illumination, unlike the simple difference which is very sensitive to changes in illumination. NDVI values can range between −1 and +1, with negative values corresponding to surfaces other than plant cover, such as snow or water, for which the red reflectance is higher than that in the NIR. Bare soils, which have red and NIR reflectance about the same order of magnitude, NDVI values are close to 0. Vegetation canopies have positive NDVI values, generally in the range of 0.1 to 0.7, with the highest values corresponding to the densest vegetation coverage. NDVI can be correlated with many plant properties. It has been, and still is, used to characterize plant health status, identify phenological changes, estimate green biomass and yields, and in many other applications. However, NDVI also has some weaknesses. Atmospheric conditions and thin cloud layers can influence the calculation of NDVI from satellite data. When vegetation cover is low, everything under the canopy influences the reflectance signal that will be recorded. This can be bare soil, plant litter, or other vegetation. Each of these types of ground cover will have its own spectral signature, different from that of the vegetation being studied. Other indices to correct NDVI defects or to estimate other vegetation parameters have been proposed, such as the normalized difference water index or NDWI (Gao, 1996), which uses two wavelengths located respectively in the NIR and the SWIR regions (750–2500 nm) to track changes in plant moisture content and water stress (Eq. 2.2.11). Both wavelengths are located in a high reflectance plateau (Fig. 2.2.8) where the vegetation scattering properties are expected to be about the same. The SWIR reflectance is affected by the water content of the vegetation. The combination of the NIR and the SWIR wavelength is thus not sensitive to the internal structure of the leaf but is affected by vegetation water content. The normalized difference water index is: \[ NDWI=\frac{R_{NIR}-R_{SWIR}}{R_{NIR}+R_{SWIR}} \] where R NIR is the reflectance in the NIR spectral region (one wavelength selected over the 750–870 nm spectral range) and R SWIR is the reflectance in the SWIR spectral region around 1240 nm (water absorption band). Gao (1996) proposed using R NIR equal to reflectance at 860 nm and R SWIR at 1240 nm. Absorption spectroscopy is widely used for monitoring and characterizing vegetation at different spatial, spectral, and temporal scales. Sensors are available mainly for broad-band multispectral or narrow-band hyperspectral data acquisition. Platforms are space-borne for satellite-based sensors, airborne for sensors on manned and unmanned airplanes, and ground-based for field and laboratory-based sensors. Satellites have been used for remote sensing imagery in agriculture since the early 1970s (Bauer and Cipra, 1973; Doraiswamy et al., 2003) when Landsat 1 (originally known as Earth Resources Technology Satellite 1) was launched. Equipped with a multispectral scanner with four wavelength channels (one green, one red and two IR bands), this satellite was able to acquire multispectral images with 80 m spatial resolution and 18-day revisit time (Mulla 2013). Today, numerous multispectral satellite sensors are available and provide observations useful for assessing vegetation properties far better than Landsat 1. Landsat 8, for example, launched in 2013, offers nine spectral bands in the Vis to short-wave IR spectral range (i.e., 400–2500 nm) with a spatial resolution of 15–30 m and a 16-day revisit time. Sentinel-2A and Sentinel-2B sensors launched in 2015 and 2017, respectively, have 13 spectral bands (400–2500 nm) and offer 10–30 m multi-spectral global coverage and a revisit time of less than 10 days. Hyperspectral sensors, however, are still poorly available on satellites due to their cost and their relatively short operating life. Among them, Hyperion (EO-1 platform) has 220 spectral bands over the 400–2500 nm spectral range, a spatial resolution of 30 m, and a spectral resolution of 10 nm. The next generation, such as PRISMA (PRecursore IperSpettrale della Missione Applicativa) with a 30 m spatial resolution and a wavelength range of 400–2505 nm and the EnMAP (Environmental Mapping and Analysis Program) with a 30 m spatial resolution and a wavelength range of 400–2500 nm (Transon et al., 2018), indicate the future for this technology. Some companies now use satellite images to provide a service to help farmers manage agricultural plots. Farmstar (www.myfarmstar.com/web/en) and Oenoview ( https://www.icv.fr/en/viticulture-oenology-consulting/oenoview ), for example, support management of inputs and husbandry in cereal and vine crops, respectively. However, satellite-based sensors often have an inadequate spatial resolution for precision agriculture applications. Some farm management decisions, such as weed detection and management, require images with a spatial resolution in the order of one centimeter and, for emergent situations (such as to monitor nutrient stress and disease), a temporal resolution of less than 24 hours (Zhang and Kovacs, 2012). Airborne sensors are today able to produce data from multispectral to hyperspectral sensors with wavelengths ranging from Vis to MIR, with spatial resolutions ranging from sub-meter to kilometers and with temporal frequencies ranging from 30 min to weeks or months. Significant advancements in unmanned aerial vehicle (UAV) technology as well as in hyperspectral and multispectral sensors (in terms of both weight and image acquisition modes) allow for the combination of these tools to be used routinely for precision agricultural applications. The flexibility of these sensors, their availability and the high achievable spatial resolutions (cm) make them an alternative to satellite sensors. Multispectral sensors embedded on UAV platforms have been used in various agricultural studies, for example, to detect diseases in citrus trees (Garcia-Ruiz et al., 2013), grain yield in rice (Zhou et al., 2017) and for mapping vineyard vigor (Primicerio et al., 2012). UAV systems with multispectral imaging capability are used routinely by companies to estimate the nitrogen needs of plants. This information, given in near real-time to farmers, helps them to make decisions about management. Information extracted from airborne images are also used for precision farming to enhance planning of agricultural interventions or management of agricultural production at the scale of farm fields. Ground-based spectroscopic sensors have also been developed for agricultural purposes. They collect reflectance data from short distances and can be mounted on tractors or held by hand. For example, the Dualex Force A hand-tool leaf clip ( https://www.force-a.com/fr/produits/dualex ) is adapted to determine the optical absorbance of the epidermis of a leaf in the ultraviolet (UV) optical range through the differential measurement of the fluorescence of chlorophyll as well as the chlorophyll content of the leaf using different wavelengths in the red and NIR ranges. Using internal model calibration, this tool calculates leaf chlorophyll content, epidermal UV-absorbance and a nitrogen balance index (NBI). This information could then be used to obtain valuable indicators of nitrogen fertilization, plant senescence, or pathogen susceptibility. Other examples are the nitrogen sensors developed by Yara ( https://www.yara.fr/fertilisation/outils-et-services/n-sensor/ ) that enable adjustment of the nitrogen application rate in real time and at any point of the field, according to the crop’s needs. Food-Related Applications Conventional, non-imaging, spectroscopic methods are widely used for routine analysis and process control in the agri-food industry. For example, NIR spectroscopy is commonly used in the prediction of protein, moisture, and fat content in a wide range of raw materials and processed products, such as liquids, gels, and powders (Porep et al., 2015). Ultraviolet-Vis (UV-Vis) spectroscopy is a valuable tool in monitoring bioprocesses, such as the development of colored phenolic compounds during fermentation of grapes in the process of winemaking (Aleixandre-Tudo et al., 2017). The Beer-Lambert law (Equation 2.2.9) can be used to predict the concentration of a given compound given its absorbance at a specific wavelength. While conventional spectroscopic methods are useful for characterizing homogeneous products, the lack of spatial resolution leads to an incomplete assessment of heterogeneous products, such as many foodstuffs. This is particularly problematic in the case of surface contamination, where information on the location, extent, and distribution of contaminants over a food sample is required. Applications of Vis-NIR spectral imaging for food quality and safety are widespread in the scientific literature and are emerging in the commercial food industry. The heightened interest in this technique is driven mainly by the non-destructive and rapid nature of spectral imaging, and the potential to replace current labor- and time-intensive analytical methods in the production process. This section provides a brief overview of the range and scope of such applications. For a more comprehensive description of these and related applications, several informative reviews have been published describing advances in hyperspectral imaging for contaminant detection (Vejarano et al., 2017), food authentication (Roberts et al., 2018), and food quality control (Gowen et al. 2007; Baiano, 2017). Contaminant Detection The ability of spectral imaging to detect spatial variations over a field of view, combined with chemical sensitivity, makes it a promising tool for contaminant detection. The main contaminants that can be detected in the food chain using Vis-NIR include polymers, paper, insects, soil, bones, stones, and fecal matter. Diffuse reflectance is by far the most common mode of spectral imaging utilized for this purpose, meaning that primarily only surface or peripheral contamination can be detected. Of concern in the food industry is the growth of spoilage and pathogenic microorganisms at both pre-harvest and post-harvest processing stages, since these result in economic losses and potentially result in risks to human health. Vis-NIR spectral imaging methods have been demonstrated for pre-harvest detection of viral infection and fungal growth on plants, such as corn (maize) and wheat. For instance, decreases in the absorption of light in wavebands related to chlorophyll were found to be related to the destruction of chloroplasts in corn ears due to Fusarium infection (Bauriegel et al., 2011). Fecal contamination acts as a favorable environment for microbial growth, thus many studies have focused on the detection of such contamination over a wide variety of foods, including fresh produce, meat, and poultry surfaces. For example, both fluorescence and reflectance modalities have been shown to be capable of detecting fecal contamination on apples with high accuracy levels (Kim et al., 2007). Recent studies have utilized spectral imaging transmittance imaging for insect detection within fruits and vegetables, resulting in high detection levels (>80% correct classification) (Vejarano et al., 2017). Food Authentication Food ingredient authentication is necessary for the ever expanding global supply chain to ensure compliance with labeling, legislation, and consumer demand. Due to the sensitivity of vibrational spectroscopy to molecular structure and the development of advanced multivariate data analysis techniques such as chemometrics, NIR and MIR spectroscopy have been used successfully in authentication of the purity and geographical origin of many foodstuffs, including honey, wine, cheese, and olive oil. Spectral imaging, having the added spatial dimension, has been used to analyze non-homogeneous samples, where spatial variation could improve information on the authentication or prior processing of the food product, for example, in the detection of fresh and frozen-thawed meat or in adulteration of flours (Roberts et al., 2018). Food Quality Control Vis-NIR spectral imaging has been applied in a wide range of food quality control issues, such as bruise detection in mushrooms, apples, and strawberries, and in the prediction of the distribution of water, protein, or fat content in heterogeneous products such as meat, fish, cheese, and bread (Liu et al., 2017). The dominant feature in the NIR spectrum of high moisture foods is the oxygen-hydrogen (OH) bond-related peak centered around 1450 nm. The shape and intensity of this peak is sensitive to the local environment of the food matrix, and can provide information on changes in the water present in food products. This is useful since many deteriorative biochemical processes, such as microbial growth and non-enzymatic browning, rely on the availability of free water in foods. Vis-NIR spectral imaging has also been applied to quality assessment of semi-solid foods, as reviewed by Baiano (2017). For instance, transmittance spectral imaging has been used to non-destructively assess the interior quality of eggs (Zhang et al., 2015), while diffuse reflectance spectral imaging has been used to study the microstructure of yogurt (Skytte et al., 2015) and milk products (Abildgaard et al., 2015). Examples Example $\PageIndex{1}$ Example 1: Using the Beer-Lambert law to predict the concentration of an unknown solution Problem: Data were obtained from a UV-Vis optical absorption instrument, as shown in Table 2.2.2. Light absorbance was measured at 520 nm for different concentrations of a compound that has a red color. The path length was 1 cm. The goal is to use the Beer-Lambert law to calculate the molar absorptivity coefficient and determine the concentration of an unknown solution that has an absorbance of 1.52. \| Concentration (mol L −1 ) \| Absorbance at 520 nm \| \|---\|---\| \| 0.001 \| 0.21 \| \| 0.002 \| 0.39 \| \| 0.005 \| 1.01 \| \| 0.01 \| 2.02 \| Solution The first step required in calculating the molar absorptivity coefficient is to plot a graph of absorbance as a function of concentration, as shown in Figure 2.2.9. The data follow a linear trend, indicating that the assumptions of the Beer-Lambert law are satisfied. To calculate the molar absorptivity coefficient, it is first necessary to calculate the line of best linear fit to the data. This is achieved here using the “add trendline” function in Excel. The resultant line of best fit is shown in Figure 2.2.10. The equation of this line is y = 201.85x. Compare this equation to the Beer-Lambert law (Equation 2.2.9): $ A=\epsilon bC $ (Equation $\PageIndex{9}$ where A = absorbance (unitless) ε = molar absorptivity or molar extinction coefficient = Beer-Lambert proportionality constant (L mol −1 cm −1 ) b = path length of the sample (cm) C = concentration (mol L −1 ) In this example, ε b = 201.85, where b is the path length, defined in the problem as 1 cm. Consequently, ε = 201.85 (L mol −1 cm −1 ). To calculate the concentration of the unknown solution, substitute the absorbance of the unknown solution (1.52) into the equation of best linear fit, resulting in a concentration of 0.0075 mol L −1 . This type of calculation can be used for process or quality control in the food industry or for environmental monitoring such as water quality assessment. Example $\PageIndex{2}$ Example 2: Calculation of vegetation indices from a spectral image Problem: The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) developed by the National Aeronautics and Space Administration (NASA) is one of the foremost spectral imaging instruments for Earth remote sensing (NASA, n. d.). An agricultural scene was gathered by flying over the Indian Pines test site in northwestern Indiana (U.S.) and consists of 145 × 145 pixels and 224 spectral reflectance bands in the wavelength range 400–2500 nm. The Indian Pines scene (freely available at https://doi.org/10.4231/R7RX991C ; Baumgardner et al., 2015) contains two-thirds agricultural land and one-third forest or other natural perennial vegetation. There are also two major dual lane highways and a rail line, as well as some low-density housing, other structures, and smaller roads present in the scene. The ground truth image shows the designation of various plots and regions in the scene, and is designated into sixteen classes, as shown in Figure 2.2.11. The average radiance spectrum of four classes of land cover in the scene is plotted in Figure 2.2.12. Table 2.2.3 shows the data corresponding to the plots shown in Figure 2.2.11. Using the mean radiance values, calculate the NDVI and NDWI for each class of land cover. Please note: In this example, the mean radiance values are being used for illustration purposes. This simplification is based on the assumption that the radiation receipt is constant across all wavebands so radiance is assumed to be linearly proportional to reflectance (ratio of reflected to total incoming energy). Typically, vegetation indices are calculated from pixel-level reflectance spectra. \| Grass-Pasture \| Grass-Trees \| Grass-Pasture-Mowed \| Hay-Windrowed \| Stone-Steel Towers \| \| \|---\|---\|---\|---\|---\|---\| \| NDVI \| 0.38 \| 0.24 \| 0.03 \| 0.09 \| −0.25 \| \| NDWI \| 0.5 \| 0.38 \| 0.45 \| 0.35 \| 0.35 \| By applying the calculation to each pixel spectrum in the image, it is possible to create images of the NDVI and NDWI, as shown in Figure 2.2.13. The NDVI highlights regions of vegetation in red, regions of crop growth and soil in light green-blue, and regions of stone in darker blue. The NDWI, sensitive to changes in water content of vegetation canopies, shows regions of high water content in red, irregularly distributed in the wooded regions. Image Credits Figure 1. Gorretta, N. (CC By 4.0). (2020). Schematic of a sinusoidal wave described by its wavelength. Figure 2. Gorretta, N. (CC By 4.0). (2020). Electromagnetic spectrum. Figure 3. Gorretta, N. (CC By 4.0). (2020). Simplified energy diagram showing (a) absorption, (b) emission of a photon by a molecule, (c) diffusion process. Figure 4. Gorretta, N. (CC By 4.0). (2020). Absorption of light by a sample. Figure 5. Gorretta, N. (CC By 4.0). (2020). Schematic diagram showing the path of light for different modes of light measurement, i.e. (a) transmission, (b) reflection, and (c) diffuse reflection. Figure 6. Gorretta, N. (CC By 4.0). (2020). Spectrometer configuration: transmission diffraction grating. Figure 7. Gorretta, N. (CC By 4.0). (2020). Hyperspectral imaging sensing mode: (a) reflectance mode, (b) transmission mode. Figure 8. Gorretta, N. (CC By 4.0). (2020). A green vegetation spectrum. Figure 9. Gowen, A. A. (CC By 4.0). (2020). Plot of absorbance at 520 nm as a function of concentration. Figure 10. Gowen, A. A. (CC By 4.0). (2020). Plot of absorbance at 520 nm as a function of concentration showing line and equation of best linear fit to the data. Figure 11. Gowen, A. A. (CC By 3.0). (2015). Indian Pines ground truth image showing various plots and regions in the scene, designated into sixteen classes. Citation might be: Baumgardner, M. F., L. L. Biehl, and D. A. Landgrebe. 2015. “220 Band AVIRIS Hyperspectral Image Data Set: June 12, 1992 Indian Pine Test Site 3.” Purdue University Research Repository. doi:10.4231/R7RX991C. This item is licensed CC BY 3.0. Figure 12. Gowen, A. A. (CC By 4.0). (2020). Indian Pines average reflectance spectrum of four classes of land cover in the scene shown in figure 11. Figure 13. Gowen, A. A. (CC BY 4.0). (2020). NDVI and NDWI calculation of Indian Pines images. References Abildgaard, O. H., Kamran, F., Dahl, A. B., Skytte, J. L., Nielsen, F. D., Thomsen, C. L., . . . Frisvad, J. R. (2015). Non-invasive assessment of dairy products using spatially resolved diffuse reflectance spectroscopy. Appl. Spectrosc. , 69 (9), 1096–1105. https://doi.org/10.1366/14-07529 . Aleixandre-Tudo, J. L., Buica, A., Nieuwoudt, H., Aleixandre, J. L., & du Toit, W. (2017). Spectrophotometric analysis of phenolic compounds in grapes and wines. J. Agric. Food Chem. , 65 (20), 4009-4026. https://doi.org/10.1021/acs.jafc.7b01724 . Asner, G. P. (1998). Biophysical and biochemical sources of variability in canopy reflectance. Remote Sensing Environ. , 64 (3), 234-253. https://doi.org/10.1016/S0034-4257(98)00014-5 . Baiano, A. (2017). Applications of hyperspectral imaging for quality assessment of liquid based and semi-liquid food products: A review. J. Food Eng. , 214 , 10-15. https://doi.org/10.1016/j.jfoodeng.2017.06.012 . Bauer, M. E., & Cipra, J. E. (1973). Identification of agricultural crops by computer processing of ERTS MSS Data. Proc. Symp. on Significant Results Obtained from the Earth Resources Technology Satellite. Retrieved from http://agris.fao.org/agris-search/search.do?recordID=US201302721443 . Baumgardner, M. F., Biehl, L. L., & Landgrebe, D. A. (2015). 220 Band AVIRIS hyperspectral image data set: June 12, 1992 Indian Pine Test Site 3. Purdue University Research Repository. https://doi.org/10.4231/R7RX991C . Bauriegel, E., Giebel, A., & Herppich, W. B. (2011). Hyperspectral and chlorophyll fluorescence imaging to analyse the impact of Fusarium culmorum on the photosynthetic integrity of infected wheat ears. Sensors , 11 (4), 3765-3779. https://doi.org/10.3390/s110403765 . Bohr, N. (1913). I. On the constitution of atoms and molecules. London Edinburgh Dublin Philosophical Magazine J. Sci. , 26 (151), 1-25. https://doi.org/10.1080/14786441308634955 . Bursey, M. M. (2017). A brief history of spectroscopy. Access Science . https://doi.org/10.1036/1097-8542.BR0213171 . De Broguie, L. V. 1925. On the theory of quanta. Paris, France. Doraiswamy, P. C., Moulin, S., Cook, P. W., & Stern, A. (2003). Crop yield assessment from remote sensing. Photogrammetric Eng. Remote Sensing , 69 (6), 665-674. doi.org/10.14358/PERS.69.6.665. 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Treatise on light. Macmillan. Retrieved from http://archive.org/details/treatiseonlight031310mbp . Kim, M. S., Chen, Y.-R., Cho, B.-K., Chao, K., Yang, C.-C., Lefcourt, A. M., & Chan, D. (2007). Hyperspectral reflectance and fluorescence line-scan imaging for online defect and fecal contamination inspection of apples. Sensing Instrumentation Food Qual. Saf. , 1 (3), 151. doi.org/10.1007/s11694-007-9017-x. Liu, Y., Pu, H., & Sun, D.-W. (2017). Hyperspectral imaging technique for evaluating food quality and safety during various processes: A review of recent applications. Trends Food Sci. Technol. , 69 , 25-35. doi.org/10.1016/j.jpgs.2017.08.013. Mulla, D. J. (2013). Twenty five years of remote sensing in precision agriculture: Key advances and remaining knowledge gaps. Biosyst. Eng. , 114 (4), 358-371. https://doi.org/10.1016/j.biosystemseng.2012.08.009 . NASA (n. d.). Airborne visible/infrared imaging spectrometer: AVIRIS overview. NASA Jet Propulsion Laboratory, California Institute of Technology. https://www.jpl.nasa.gov/missions/airborne-visible-infrared-imaging-spectrometer-aviris/ . Ollinger, S. V. (2011). Sources of variability in canopy reflectance and the convergent properties of plants. New Phytol. , 189 (2), 375-394. doi.org/10.1111/j.1469-8137.2010.03536.x. Osborne, B. G., Fearn, T., Hindle, P. H., & Osborne, B. G. (1993). Practical NIR spectroscopy with applications in food and beverage analysis (Vol. 2). Longman Scientific & Technical. Pasquini, C. (2003). Near infrared spectroscopy: Fundamentals, practical aspects and analytical applications. J. Brazilian Chem. Soc. , 14 (2), 198-219. https://doi.org/10.1590/S0103-50532003000200006 . Pasquini, C. (2018). Near infrared spectroscopy: A mature analytical technique with new perspectives: A review. Anal. Chim. Acta , 1026 , 8-36. https://doi.org/10.1016/j.aca.2018.04.004 . Pavia, D. L., Lampman, G. M., Kriz, G. S., & Vyvyan, J. A. (2008). Introduction to spectroscopy. Cengage Learning. Porep, J. U., Kammerer, D. R., & Carle, R. (2015). On-line application of near infrared (NIR) spectroscopy in food production. Trends Food Sci. Technol. , 46 (2, Part A), 211-230. doi.org/10.1016/j.jpgs.2015.10.002. Primicerio, J., Di Gennaro, S. F., Fiorillo, E., Genesio, L., Lugato, E., Matese, A., & Vaccari, F. P. (2012). A flexible unmanned aerial vehicle for precision agriculture. Precision Agric. , 13 (4), 517-523. doi.org/10.1007/s11119-012-9257-6. Roberts, J., Power, A., Chapman, J., Chandra, S., & Cozzolino, D. (2018). A short update on the advantages, applications and limitations of hyperspectral and chemical imaging in food authentication. Appl. Sci. , 8 (4), 505. https://doi.org/10.3390/app8040505 . Rouse Jr., J. W., Haas, R. H., Schell, J. A., & Deering, D. (1974). Monitoring vegetation systems in the Great Plains with ERTS. NASA Special Publ. 351. Schuster, A. (1911). Encyclopedia Britannica, 2 :477. Skytte, J., Moller, F., Abildgaard, O., Dahl, A., & Larsen, R. (n. d.). Discriminating yogurt microstructure using diffuse reflectance images. Proc. Scandinavian Conf. on Image Analysis (pp. 192-203). Springer. doi.org/10.1007/978-3-319-19665-7_16. Sun, D.-W. (2009). Infrared spectroscopy for food quality analysis and control. Academic Press. Thomas, N. C. (1991). The early history of spectroscopy. J. Chem. Education , 68 (8), 631. https://doi.org/10.1021/ed068p631 . Remote Sensing, 10 (2). https://doi.org/10.3390/rs10020157. Vejarano, R., Siche, R., & Tesfaye, W. (2017). Evaluation of biological contaminants in foods by hyperspectral imaging: A review. Int. J. Food Properties , 20 (sup2), 1264-1297. doi.org/10.1080/10942912.2017.1338729. Zhang, C., & Kovacs, J. M. (2012). The application of small unmanned aerial systems for precision agriculture: A review. Precision Agric. , 13 (6), 693-712. doi.org/10.1007/s11119-012-9274-5. Zhang, W., Pan, L., Tu, S., Zhan, G., & Tu, K. (2015). Non-destructive internal quality assessment of eggs using a synthesis of hyperspectral imaging and multivariate analysis. J. Food Eng. , 157 , 41-48. https://doi.org/10.1016/j.jfoodeng.2015.02.013 . Zhou, X., Zheng, H. B., Xu, X. Q., He, J. Y., Ge, X. K., Yao, X., . . . Tian, Y. C. (2017). Predicting grain yield in rice using multi-temporal vegetation indices from UAV-based multispectral and digital imagery. ISPRS J. Photogrammetry Remote Sensing , 130 , 246-255. https://doi.org/10.1016/j.isprsjprs.2017.05.003 .	10,060	common-pile/libretexts_filtered	https://eng.libretexts.org/Bookshelves/Biological_Engineering/Introduction_to_Biosystems_Engineering_(Holden_et_al.)/02%3A_Information_Technology_Sensors_and_Control_Systems/2.02%3A_Visible_and_Near_Infrared_Optical_Spectroscopic_Sensors_for_Biosystems_Engineering	libretexts	libretexts-0000.json.gz:14849	https://eng.libretexts.org/Bookshelves/Biological_Engineering/Introduction_to_Biosystems_Engineering_(Holden_et_al.)/02%3A_Information_Technology_Sensors_and_Control_Systems/2.02%3A_Visible_and_Near_Infrared_Optical_Spectroscopic_Sensors_for_Biosystems_Engineering
01ytgWGi-Y-_Ge1u	19.4: Anatomy of Lymphatic Organs and Tissues	19.4: Anatomy of Lymphatic Organs and Tissues By the end of this section, you will be able to: - Describe the structure and function of the primary and secondary lymphatic organs - Describe the structure, function, and location of lymphoid tissues Lymphoid organs are distinct structures consisting of multiple tissue types. The category can be further subdivided into primary lymphoid organs, which support lymphocyte production and development, and secondary lymphoid organs, which support lymphocyte storage and function. Lymphoid tissues are concentrations of lymphocytes and other immune cells within other organs of the body. Primary Lymphoid Organs and Lymphocyte Development The differentiation and development of B and T cells is critical to the adaptive immune response. When the body is exposed to a new pathogen, lymphocytes of the adaptive immune response must "learn" the new antigen associated with the pathogen, mount an effective response to eradicate the pathogen, and "remember" the antigen in case the body is exposed again in the future by forming memory cells. It is also through this process that the body (ideally) learns to destroy only pathogens and leaves the body’s own cells relatively intact. The primary lymphoid organs are the bone marrow and thymus gland. The lymphoid organs are where lymphocytes proliferate and mature. Bone Marrow Yellow bone marrow consists of adipose tissue, consisting largely of fat cells for energy storage (Figure $\PageIndex{1}$) and is primarily located in the medullary cavity of adult long bones. Red bone marrow is a loose collection of cells where hematopoiesis (blood cell formation) occurs surrounding a framework of reticular connective tissue. Red bone marrow is primarily located surrounding the trabeculae of spongy bone. Hematopoiesis is summarized in Figure $\PageIndex{2}$ and was covered in more detail in the blood chapter. In the embryo, blood cells are made in the yolk sac. As development proceeds, this function is taken over by the spleen, lymph nodes, and liver. Later, the red bone marrow takes over most hematopoietic functions, although the final stages of the differentiation of some cells may take place in other organs. The B cell undergoes nearly all of its development in the red bone marrow, whereas the immature T cell, called a thymocyte , leaves the bone marrow and matures largely in the thymus gland. Thymus The thymus gland is a bilobed organ found in the space between the sternum and the aorta of the heart (Figure $\PageIndex{3}$) that serves as a specialized structure in which T lymphocytes mature. The thymus is most active early in life as you are exposed to and build immunity to many pathogens. After puberty, the thymus slowly but continuously decreases in activity and size as its tissue is replaced with a mix of fibrous and adipose connective tissues. In the thymus, the maturation of T lymphocytes begins with thymocytes. Thymocytes travel through the bloodstream from the red bone marrow to the thymus. Thymocytes are precursors to T lymphocytes that lack the surface proteins mature T lymphocytes use to recognize an antigen and coordinate an adaptive immune response. There is a multi-step physiological process by which T lymphocytes mature into naïve T lymphocytes ready to be activated for an adaptive immune response. Dense irregular connective tissue holds the lobes of the thymus closely together but also separates them and forms a fibrous capsule. The fibrous capsule further divides the thymus into lobules via extensions called trabeculae. Blood vessels and nerves are routed within the trabeculae. The outer region of each lobule is known as the cortex and here the structure of the thymus forms a blood-thymus barrier to prevent the thymocytes from being exposed to antigens from the bloodstream before they mature. The densely packed thymocytes in the cortex stain more intensely than the rest of the thymus (see Figure $\PageIndex{3}$). The medulla contains a less dense collection of thymocytes, epithelial cells, macrophages, and dendritic cells, so it appears more lightly stained in the micrograph. Thymocytes move from the cortex to the medulla as they mature where the lack of the blood-thymus barrier allows them to enter the bloodstream and travel to other lymphatic structures to await activation for an adaptive immune response. AGING AND THE... Immune System By the year 2050, 25 percent of the population of the United States will be 60 years of age or older. The CDC estimates that 80 percent of those 60 years and older have one or more chronic diseases associated with deficiencies of the immune systems. This loss of immune function with age is called immunosenescence. To treat this growing population, medical professionals must better understand the aging process. One major cause of age-related immune deficiencies is thymic involution, the shrinking of the thymus gland that begins after puberty, at a rate of about three percent tissue loss per year, and continues until 35–45 years of age, when the rate declines to about one percent loss per year for the rest of one’s life. At that pace, the total loss of thymic epithelial tissue and thymocytes would occur at about 120 years of age. Thus, this age is a theoretical limit to a healthy human lifespan. Thymic involution has been observed in all vertebrate species that have a thymus gland. Animal studies have shown that transplanted thymic grafts between inbred strains of mice involuted according to the age of the donor and not of the recipient, implying the process is genetically programmed. There is evidence that the thymic microenvironment, so vital to the development of naïve T cells, loses thymic epithelial cells according to the decreasing expression of the FOXN1 gene with age. It is also known that thymic involution can be altered by hormone levels. Sex hormones such as estrogen and testosterone enhance involution, and the hormonal changes in pregnant women cause a temporary thymic involution that reverses itself, when the size of the thymus and its hormone levels return to normal, usually after lactation ceases. What does all this tell us? Can we reverse immunosenescence, or at least slow it down? The potential is there for using thymic transplants from younger donors to keep thymic output of naïve T cells high. Gene therapies that target gene expression are also seen as future possibilities. The more we learn through immunosenescence research, the more opportunities there will be to develop therapies, even though these therapies will likely take decades to develop. The ultimate goal is for everyone to live and be healthy longer, but there may be limits to immortality imposed by our genes and hormones. DISORDERS OF THE... Immune System: Autoimmune Responses The worst cases of the immune system over-reacting are autoimmune diseases. Somehow, tolerance breaks down and the immune systems in individuals with these diseases begin to attack their own bodies, causing significant damage. The trigger for these diseases is, more often than not, unknown and the treatments are usually based on resolving or minimizing the symptoms using immunosuppressive and anti-inflammatory drugs such as steroids. These diseases can be localized and crippling, as in rheumatoid arthritis, or diffuse in the body with multiple symptoms that differ in different individuals, as is the case with systemic lupus erythematosus (Figure $\PageIndex{4}$). Environmental triggers seem to play large roles in autoimmune responses. One explanation for the breakdown of tolerance is that, after certain bacterial infections, an immune response to a component of the bacterium cross-reacts with a self-antigen. This mechanism is seen in rheumatic fever, a result of infection with Streptococcus bacteria, which causes strep throat. The antibodies to this pathogen’s M protein cross-react with an antigenic component of heart myosin, a major contractile protein of the heart that is critical to its normal function. The antibody binds to these molecules and activates complement proteins, causing damage to the heart, especially to the heart valves. On the other hand, some theories propose that having multiple common infectious diseases actually prevents autoimmune responses. The fact that autoimmune diseases are rare in countries that have a high incidence of infectious diseases supports this idea. There are genetic factors in autoimmune diseases as well. Overall, there are more than 80 different autoimmune diseases, which are a significant health problem in the elderly. Table $\PageIndex{1}$ lists several of the most common autoimmune diseases, along with the antigens that are targeted and symptoms of the disease. \| Disease \| Autoantigen \| Symptoms \| \|---\|---\|---\| \| Celiac disease \| Tissue transglutaminase \| Damage to small intestine \| \| Diabetes mellitus type I \| Beta cells of pancreas \| Low insulin production; inability to regulate serum glucose \| \| Graves’ disease \| Thyroid-stimulating hormone receptor (antibody blocks receptor) \| Hyperthyroidism \| \| Hashimoto’s thyroiditis \| Thyroid-stimulating hormone receptor (antibody mimics hormone and stimulates receptor) \| Hypothyroidism \| \| Lupus erythematosus \| Nuclear DNA and proteins \| Damage to many body systems \| \| Myasthenia gravis \| Acetylcholine receptor in neuromuscular junctions \| Debilitating muscle weakness \| \| Rheumatoid arthritis \| Joint capsule antigens \| Chronic inflammation of joints \| Secondary Lymphoid Organs and their Roles in Immune Responses Lymphocytes develop and mature in the primary lymphoid organs, but they mount immune responses from the secondary lymphoid organs . A naïve lymphocyte is one that has left the primary organ and entered a secondary lymphoid organ. Naïve lymphocytes are fully functional immunologically, sometimes referred to as immunocompetency, but have yet to encounter an antigen to which to respond. In addition to circulating in the blood and lymph, lymphocytes concentrate in secondary lymphoid organs, which include the lymph nodes, spleen, and lymphoid tissues associated with several organs in the body. All of these tissues have many features in common, including the following: - An internal structure of reticular connective tissue with associated fixed macrophages - The presence of lymphoid follicles , collections of lymphocytes, with specific B cell-rich and T cell-rich areas - Germinal centers , which are the sites of activated (rapidly dividing) B lymphocytes and plasma cells, with the exception of the spleen - Specialized post-capillary vessels known as high endothelial venules ; the cells lining these venules are thicker and more columnar than normal endothelial cells, which allow cells from the blood to directly enter these tissues Lymph Nodes As described in the previous section, lymph nodes are positioned at regular intervals along the length of lymphatic vessels. Lymph nodes function to remove debris and pathogens from the lymph, and are thus sometimes referred to as the “filters of the lymph” (Figure $\PageIndex{5}$). Any bacteria that infect the interstitial fluid are taken up by the lymphatic capillaries and transported to a regional lymph node. Dendritic cells and macrophages within this organ internalize and kill many of the pathogens and debris that pass through, thereby removing them from the body. The lymph node is the most common site of activation of adaptive immune responses mediated by T cells, B cells, and accessory cells of the adaptive immune system. This is why swollen lymph nodes can be a sign of infection. Like the thymus, the bean-shaped lymph nodes are surrounded by a tough capsule of dense connective tissue and are separated into compartments by trabeculae, extensions of the capsule. In addition to the structure provided by the capsule and trabeculae, the structural support of the lymph node is provided by a series of reticular fibers laid down by fibroblasts of its reticular connective tissue framework. Several afferent lymphatic vessels deliver lymph into the convex side of a lymph node and a one-way valve in each vessel near where it connects with the lymph node prevents back-flow of lymph. One or two efferent lymphatic vessels allow lymph to flow out of the concave hilum of the lymph node. The tissue inside the lymph node consists of two generalized regions: the cortex and the medulla. The cortex is nearest the convex side of the node and contains lymphoid follicles where activated lymphocytes proliferate. The medulla, nearest the hilum of each node, is rich with lymphocytes (T cells, B cells, and plasma cells), as well as macrophages and dendritic cells. Spleen The spleen is located inferior and medial to the curve of the diaphragm and lateral to the stomach in the upper left quadrant of the abdomen. It is built on a framework of reticular connective tissue and surrounded by a capsule of dense irregular connective tissue that invaginates into trabeculae to divide the spleen into nodules (Figure $\PageIndex{6}$). Upon entering the spleen, the splenic artery splits into several arterioles and eventually into sinusoid capillaries. Blood from the capillaries subsequently collects in venules that drain into the splenic vein. Within each splenic nodule is a large area of red pulp surrounding the sinusoid capillaries that is so-called because it consists mainly of erythrocytes. The red pulp consists of reticular fibers with fixed macrophages attached, free macrophages, and other formed elements of the blood, including some lymphocytes. The red pulp primarily functions in phagocytosis of worn-out erythrocytes and bloodbourne pathogens. Aside from the blood vessels, the remaining tissue of each nodule is called the white pulp , so-called because it lacks the erythrocytes found in the red pulp. The white pulp surrounds the arteriole and resembles the lymphoid follicles of the lymph nodes. It consists of germinal centers of dividing B cells surrounded by T cells and accessory cells, including macrophages and dendritic cells. Germinal centers function as a site of T cell and B cell activation. The marginal zone is the region where the white pulp transitions to the red pulp and their functions mix. Lymphoid Nodules The other lymphoid tissues, lymphoid nodules , have a simpler architecture than the spleen and lymph nodes in that they consist of a dense cluster of lymphocytes on a framework of reticular connective tissue without a surrounding fibrous capsule. These nodules are associated with the mucus membranes of the respiratory and digestive tracts, areas routinely exposed to environmental pathogens. Tonsils are lymphoid nodules located along the inner surface of the pharynx and are important in developing immunity to oral pathogens (Figure $\PageIndex{7}$). - The pharyngeal tonsil , sometimes referred to as the adenoid, is located in the superoposterior of the nasopharynx - The palatine tonsils are in the lateral wall of the oropharynx - The lingual tonsil faces the oropharynx in the wall at the posterior of the tongue Swelling of the tonsils is an indication of an active immune response to infection. Histologically, tonsils do not contain a complete capsule, and the epithelial layer invaginates deeply into the interior of the tonsil to form tonsillar crypts. The crypts allow all sorts of materials taken into the body through eating and breathing to accumulate in the tonsils, actually “encouraging” pathogens to penetrate deep into the tonsillar tissues where T cells and B cells in the germinal centers can be activated for an adaptive immune response. This seems to be the major function of tonsils—to help children’s bodies recognize, destroy, and develop immunity to common environmental pathogens so that they will be protected in their later lives. Tonsils are often removed in those children who have recurring throat infections, especially those involving the palatine tonsils on either side of the throat, whose swelling may interfere with their breathing and/or swallowing. Mucosa-associated lymphoid tissue (MALT) consists of an aggregate of lymphoid follicles directly associated with the mucous membrane epithelia. MALT makes up dome-shaped structures found underlying the mucosa of the gastrointestinal tract, breast tissue, lungs, and eyes. Peyer’s patches, a type of MALT in the small intestine, are especially important for immune responses against ingested substances (Figure $\PageIndex{8}$). Peyer’s patches contain specialized endothelial cells called M (or microfold) cells that sample material from the intestinal lumen and transport it to nearby follicles so that adaptive immune responses to potential pathogens can be mounted. Concept Review Lymphoid organs are comprised of multiple tissues forming a distinct structure in the body. Primary lymphoid organs include bone marrow and the thymus. Lymphocytes and other blood cells are produced in red bone marrow while lipids are stored for long-term energy in yellow bone marrow. B lymphocytes remain in red bone marrow to develop into naïve B lymphocytes. The thymus is the organ in which immature T lymphocytes are stored and develop into naïve T lymphocytes. Naïve T and B lymphocytes travel to secondary lymphoid organs, lymph nodes and the spleen, from where they can be activated for the adaptive immune response. Lymph nodes filter lymph for invaders, abnormal cells, and debris as it drains to the bloodstream through lymphatic vessels. The spleen, in the white pulp, filters the blood for invaders, abnormal cells, and debris as it circulates through the bloodstream. The red pulp of the spleen also filters the blood and serves to remove worn-out red blood cells from circulation. Concentrations of lymphocytes and other immune cells within mucus membranes of other organ systems are called lymphoid tissues or nodules. The tonsils surround the pharynx while mucosa-associated lymphoid tissue (MALT) are found in mucus membranes of the gastrointestinal tract, breast tissue, lungs, and eyes. Review Questions Q. Which of the lymphoid nodules is most likely to see food-bourne antigens first? A. tonsils B. Peyer’s patches C. bronchus-associated lymphoid tissue D. mucosa-associated lymphoid tissue - Answer - Answer: A Critical Thinking Questions Q. Compare and contrast functions of the lymph nodes and the spleen. - Answer - A. Both lymph nodes and the spleen filter transport fluids in the body for pathogens, abnormal cells, and debris. Lymph nodes are positioned at intervals along lymphatic vessels to filter lymph as it travels through the lymphatic vessels. The spleen filters blood as it travels through the blood stream. Both lymph nodes and the spleen are secondary lymphoid organs meaning they contain concentrations of naïve lymphocytes and other immune cells from which an adaptive immune response can be mounted. Glossary - afferent lymphatic vessels - lead into a lymph node - bone marrow - tissue found inside bones; the site of all blood cell differentiation and maturation of B lymphocytes - efferent lymphatic vessels - lead out of a lymph node - germinal centers - clusters of rapidly proliferating B cells found in secondary lymphoid tissues - high endothelial venules - vessels containing unique endothelial cells specialized to allow migration of lymphocytes from the blood to the lymph node - lingual tonsil - lymphoid nodule in the anterior wall of the oropharynx posterior to the tongue - lymph node - one of the bean-shaped organs found associated with the lymphatic vessels - lymphoid nodules - unencapsulated patches of lymphoid tissue found throughout the body - mucosa-associated lymphoid tissue (MALT) - lymphoid nodule associated with the mucosa - palatine tonsils - lymphoid nodules in the right and left lateral walls of the oropharynx - pharyngeal tonsil (adenoid) - lymphoid nodule in the superoposterior wall of the nasopharynx - primary lymphoid organ - site where lymphocytes mature and proliferate; red bone marrow and thymus gland - red pulp - region of a spleen nodule that is so-called because it is filled with many erythrocytes that surrounds the sinusoid capillaries and functions primarily to remove worn-out erythrocytes from circulation - secondary lymphoid organs - sites where lymphocytes mount adaptive immune responses; examples include lymph nodes and spleen - spleen - secondary lymphoid organ that filters pathogens from the blood (white pulp) and removes degenerating or damaged blood cells (red pulp) - thymocyte - immature T cell found in the thymus - thymus - primary lymphoid organ; where T lymphocytes proliferate and mature - tonsils - lymphoid nodules associated with the pharynx - white pulp - region of a spleen nodule that is filled with germinal centers surrounding the arteriole that functions to activate B cells and T cells Contributors and Attributions - OpenStax Anatomy & Physiology (CC BY 4.0). 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2IfoD7CrVfTZGDOw	BC Reads: Adult Literacy Fundamental English - Reader 1	8 Canada’s Tallest Tree Click play on the following audio player to listen along as you read this section. A man named Randy liked to hunt trees. He looked for big trees and old trees. He made maps to show where these trees were. He did not want to cut them down. He wanted people to take care of them. Randy was told of a very tall tree on Vancouver Island. The tree was said to be 314 feet tall. That would make it the tallest tree in Canada. Randy set out to find the tree. But someone else found it first. It was found by a logger. Loggers wanted to cut down Canada’s tallest tree and all the trees around it. Randy made a path in the forest so people could see the tall tree. The tree was so big and beautiful it would fill them with awe. More and more people wanted to save that forest. Thanks to these people, that forest is now a park. Canada’s tallest tree is still there. There may still be a bigger tree out there. Maybe you will find it. But there are only a few old forests left in BC. Many are still at risk of being cut down.	270	common-pile/pressbooks_filtered	https://opentextbc.ca/abealfreader1/chapter/canadas-tallest-tree/	pressbooks	pressbooks-0000.json.gz:144	https://opentextbc.ca/abealfreader1/chapter/canadas-tallest-tree/
ulTLm1MKllKPr9ak	Chemistry v. 1 backup	17.4 Shifting Equilibria: Le Châtelier’s Principle Learning Objectives - Describe the ways in which an equilibrium system can be stressed - Predict the response of a stressed equilibrium using Le Châtelier’s principle As we saw in the previous section, reactions proceed in both directions (reactants go to products and products go to reactants). We can tell a reaction is at equilibrium if the reaction quotient (Q) is equal to the equilibrium constant (K). Next we address what happens when a system at equilibrium is disturbed so that Q is no longer equal to K. If a system at equilibrium is subjected to a perturbance or stress (such as a change in concentration) the position of equilibrium changes. Since this stress affects the concentrations of the reactants and the products, the value of Q will no longer equal the value of K. To re-establish equilibrium, the system will either shift toward the products (if Q < K) or the reactants (if Q > K) until Q returns to the same value as K. This process is described by Le Châtelier's principle: When a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance. As described in the previous paragraph, the disturbance causes a change in Q; the reaction will shift to re-establish Q = K. Predicting the Direction of a Reversible Reaction Le Châtelier’s principle can be used to predict changes in equilibrium concentrations when a system that is at equilibrium is subjected to a stress. However, if we have a mixture of reactants and products that have not yet reached equilibrium, the changes necessary to reach equilibrium may not be so obvious. In such a case, we can compare the values of Q and K for the system to predict the changes. Effect of Change in Concentration on Equilibrium A chemical system at equilibrium can be temporarily shifted out of equilibrium by adding or removing one or more of the reactants or products. The concentrations of both reactants and products then undergo additional changes to return the system to equilibrium. The stress on the system in Figure 17.4a is the reduction of the equilibrium concentration of SCN− (lowering the concentration of one of the reactants would cause Q to be larger than K). As a consequence, Le Châtelier’s principle leads us to predict that the concentration of Fe(SCN)2+ should decrease, increasing the concentration of SCN− part way back to its original concentration, and increasing the concentration of Fe3+ above its initial equilibrium concentration. The effect of a change in concentration on a system at equilibrium is illustrated further by the equilibrium of this chemical reaction: The numeric values for this example have been determined experimentally. A mixture of gases at 400 °C with [H2] = [I2] = 0.221 M and [HI] = 1.563 M is at equilibrium; for this mixture, Qc = Kc = 50.0. If H2 is introduced into the system so quickly that its concentration doubles before it begins to react (new [H2] = 0.442 M), the reaction will shift so that a new equilibrium is reached, at which [H2] = 0.374 M, [I2] = 0.153 M, and [HI] = 1.692 M. This gives: We have stressed this system by introducing additional H2. The stress is relieved when the reaction shifts to the right, using up some (but not all) of the excess H2, reducing the amount of uncombined I2, and forming additional HI. Effect of Change in Pressure on Equilibrium Sometimes we can change the position of equilibrium by changing the pressure of a system. However, changes in pressure have a measurable effect only in systems in which gases are involved, and then only when the chemical reaction produces a change in the total number of gas molecules in the system. An easy way to recognize such a system is to look for different numbers of moles of gas on the reactant and product sides of the equilibrium. While evaluating pressure (as well as related factors like volume), it is important to remember that equilibrium constants are defined with regard to concentration (for Kc) or partial pressure (for KP). Some changes to total pressure, like adding an inert gas that is not part of the equilibrium, will change the total pressure but not the partial pressures of the gases in the equilibrium constant expression. Thus, addition of a gas not involved in the equilibrium will not perturb the equilibrium. Check out this video to see a dramatic visual demonstration of how equilibrium changes with pressure changes. Watch Volume Effect on Equilibrium – LeChatelier’s Principle Lab Extension (0:43 min) Video Source: North Carolina School of Science and Mathematics. (2011, December 14). Volume effect on equilibrium – LeChatelier’s Principle lab extension [Video]. As we increase the pressure of a gaseous system at equilibrium, either by decreasing the volume of the system or by adding more of one of the components of the equilibrium mixture, we introduce a stress by increasing the partial pressures of one or more of the components. In accordance with Le Châtelier’s principle, a shift in the equilibrium that reduces the total number of molecules per unit of volume will be favoured because this relieves the stress. The reverse reaction would be favoured by a decrease in pressure. Consider what happens when we increase the pressure on a system in which NO, O2, and NO2 are at equilibrium: The formation of additional amounts of NO2 decreases the total number of molecules in the system because each time two molecules of NO2 form, a total of three molecules of NO and O2 are consumed. This reduces the total pressure exerted by the system and reduces, but does not completely relieve, the stress of the increased pressure. On the other hand, a decrease in the pressure on the system favours decomposition of NO2 into NO and O2, which tends to restore the pressure. Now consider this reaction: Because there is no change in the total number of molecules in the system during reaction, a change in pressure does not favour either formation or decomposition of gaseous nitrogen monoxide. Effect of Change in Temperature on Equilibrium Changing concentration or pressure perturbs an equilibrium because the reaction quotient is shifted away from the equilibrium value. Changing the temperature of a system at equilibrium has a different effect: A change in temperature actually changes the value of the equilibrium constant. However, we can qualitatively predict the effect of the temperature change by treating it as a stress on the system and applying Le Châtelier’s principle. When hydrogen reacts with gaseous iodine, heat is evolved. Because this reaction is exothermic, we can write it with heat as a product. Increasing the temperature of the reaction increases the internal energy of the system. Thus, increasing the temperature has the effect of increasing the amount of one of the products of this reaction. The reaction shifts to the left to relieve the stress, and there is an increase in the concentration of H2 and I2 and a reduction in the concentration of HI. Lowering the temperature of this system reduces the amount of energy present, favours the production of heat, and favours the formation of hydrogen iodide. When we change the temperature of a system at equilibrium, the equilibrium constant for the reaction changes. Lowering the temperature in the HI system increases the equilibrium constant: At the new equilibrium the concentration of HI has increased and the concentrations of H2 and I2 decreased. Raising the temperature decreases the value of the equilibrium constant, from 67.5 at 357 °C to 50.0 at 400 °C. Temperature affects the equilibrium between NO2 and N2O4 in this reaction The positive ΔH value tells us that the reaction is endothermic and could be written At higher temperatures, the gas mixture has a deep brown colour, indicative of a significant amount of brown NO2 molecules. If, however, we put a stress on the system by cooling the mixture (withdrawing energy), the equilibrium shifts to the left to supply some of the energy lost by cooling. The concentration of colourless N2O4 increases, and the concentration of brown NO2 decreases, causing the brown colour to fade. \| Disturbance \| Observed Change as Equilibrium is Restored \| Direction of Shift \| Effect on K \| \|---\|---\|---\|---\| \| reactant added \| added reactant is partially consumed \| toward products \| none \| \| product added \| added product is partially consumed \| toward reactants \| none \| \| decrease in volume/increase in gas pressure \| pressure decreases \| toward side with fewer moles of gas \| none \| \| increase in volume/decrease in gas pressure \| pressure increases \| toward side with more moles of gas \| none \| \| temperature increase \| heat is absorbed \| toward products for endothermic, toward reactants for exothermic \| changes \| \| temperature decrease \| heat is given off \| toward reactants for endothermic, toward products for exothermic \| changes \| Catalysts Do Not Affect Equilibrium As we learned during our study of kinetics, a catalyst can speed up the rate of a reaction. Though this increase in reaction rate may cause a system to reach equilibrium more quickly (by speeding up the forward and reverse reactions), a catalyst has no effect on the value of an equilibrium constant nor on equilibrium concentrations. The interplay of changes in concentration or pressure, temperature, and the lack of an influence of a catalyst on a chemical equilibrium is illustrated in the industrial synthesis of ammonia from nitrogen and hydrogen according to the equation A large quantity of ammonia is manufactured by this reaction. Each year, ammonia is among the top 10 chemicals, by mass, manufactured in the world. About 2 billion pounds are manufactured in the United States each year. Ammonia plays a vital role in our global economy. It is used in the production of fertilizers and is, itself, an important fertilizer for the growth of corn, cotton, and other crops. Large quantities of ammonia are converted to nitric acid, which plays an important role in the production of fertilizers, explosives, plastics, dyes, and fibres, and is also used in the steel industry. Fritz Haber In the early 20th century, German chemist Fritz Haber (Figure 17.4c) developed a practical process for converting diatomic nitrogen, which cannot be used by plants as a nutrient, to ammonia, a form of nitrogen that is easiest for plants to absorb. The availability of nitrogen is a strong limiting factor to the growth of plants. Despite accounting for 78% of air, diatomic nitrogen (N2) is nutritionally unavailable due the tremendous stability of the nitrogen-nitrogen triple bond. For plants to use atmospheric nitrogen, the nitrogen must be converted to a more bioavailable form (this conversion is called nitrogen fixation). Haber was born in Breslau, Prussia (presently Wroclaw, Poland) in December 1868. He went on to study chemistry and, while at the University of Karlsruhe, he developed what would later be known as the Haber process: the catalytic formation of ammonia from hydrogen and atmospheric nitrogen under high temperatures and pressures. For this work, Haber was awarded the 1918 Nobel Prize in Chemistry for synthesis of ammonia from its elements. The Haber process was a boon to agriculture, as it allowed the production of fertilizers to no longer be dependent on mined feed stocks such as sodium nitrate. Currently, the annual production of synthetic nitrogen fertilizers exceeds 100 million tons and synthetic fertilizer production has increased the number of humans that arable land can support from 1.9 persons per hectare in 1908 to 4.3 in 2008. In addition to his work in ammonia production, Haber is also remembered by history as one of the fathers of chemical warfare. During World War I, he played a major role in the development of poisonous gases used for trench warfare. Regarding his role in these developments, Haber said, “During peace time a scientist belongs to the World, but during war time he belongs to his country.”[1] Haber defended the use of gas warfare against accusations that it was inhumane, saying that death was death, by whatever means it was inflicted. He stands as an example of the ethical dilemmas that face scientists in times of war and the double-edged nature of the sword of science. Like Haber, the products made from ammonia can be multifaceted. In addition to their value for agriculture, nitrogen compounds can also be used to achieve destructive ends. Ammonium nitrate has also been used in explosives, including improvised explosive devices. Ammonium nitrate was one of the components of the bomb used in the attack on the Alfred P. Murrah Federal Building in downtown Oklahoma City on April 19, 1995. Indigenous Perspective: The Three Sisters Also in relation to nitrogen-fixation, a number of Indigenous communities have used another method for nitrogen fixation for hundreds of years. Termed “The Three Sisters”, corn, squash and beans are co-planted, and their symbiotic relationship allows for all three plants to produce optimum yields. The corn stalks provide support, giving the bean plants a vertical space to grow upwards. The squash plant’s large leaves help maintain soil moisture and can prevent weeds. The bean plants are a natural source of nitrogen-fixation, which helps supports all of the plants. Briefly, the bean plants host the microbe, rhizobia, that converts nitrogen from the air into ammonia. This ammonia can then be absorbed by the plant roots. To learn more about the Three Sisters, Watch Three Sisters: Companion Planting of North American Indigenous Peoples (10:54 min): Video Source: GRIN-U Education. (2021, November 16). Three Sisters: Companion planting of North American Indigenous Peoples [Video]. YouTube. It has long been known that nitrogen and hydrogen react to form ammonia. However, it became possible to manufacture ammonia in useful quantities by the reaction of nitrogen and hydrogen only in the early 20th century after the factors that influence its equilibrium were understood. To be practical, an industrial process must give a large yield of product relatively quickly. One way to increase the yield of ammonia is to increase the pressure on the system in which N2, H2, and NH3 are at equilibrium or are coming to equilibrium. The formation of additional amounts of ammonia reduces the total pressure exerted by the system and somewhat reduces the stress of the increased pressure. Although increasing the pressure of a mixture of N2, H2, and NH3 will increase the yield of ammonia, at low temperatures, the rate of formation of ammonia is slow. At room temperature, for example, the reaction is so slow that if we prepared a mixture of N2 and H2, no detectable amount of ammonia would form during our lifetime. The formation of ammonia from hydrogen and nitrogen is an exothermic process: Thus, increasing the temperature to increase the rate lowers the yield. If we lower the temperature to shift the equilibrium to favour the formation of more ammonia, equilibrium is reached more slowly because of the large decrease of reaction rate with decreasing temperature. Part of the rate of formation lost by operating at lower temperatures can be recovered by using a catalyst. The net effect of the catalyst on the reaction is to cause equilibrium to be reached more rapidly. In the commercial production of ammonia, conditions of about 500 °C, 150–900 atm, and the presence of a catalyst are used to give the best compromise among rate, yield, and the cost of the equipment necessary to produce and contain high-pressure gases at high temperatures (Figure 17.4d). Exercise 17.4a Check Your Learning Exercise (Text Version) Based on the following chemical equation, how can you increase the equilibrium concentration of hydrazine, N2H4? N2(g) + 2H2(g) ↔ N2H4(g) ∆H = 95 kJ - Add more N2 - Add more H2 - Increase temperature - All of the above Check Your Answer[2] Source: “Exercise 17.4a” is adapted from “Exercise 13.3-7” in General Chemistry 1 & 2, a derivative of Chemistry (Open Stax) by Paul Flowers, Klaus Theopold, Richard Langley & William R. Robinson, licensed under CC BY 4.0. Links to Interactive Learning Tools Explore LeChatelier’s Principle from the Physics Classroom. Attribution & References change to a reaction’s conditions that may cause a shift in the equilibrium concentrations or partial pressures of components of a reaction at equilibrium (commonly used to describe conditions before a disturbance) when a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance	3,546	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/enhancedchemistryv1/chapter/lechateliers-principle/	pressbooks	pressbooks-0000.json.gz:60081	https://ecampusontario.pressbooks.pub/enhancedchemistryv1/chapter/lechateliers-principle/
mCe1cVHvp9fYoFWG	2.22: Introduction to Measures of Center	2.22: Introduction to Measures of Center What you’ll learn to do: Use mean and median to describe the center of a distribution. In this section, we define three different measures of center: mean, median, and mode, all of which are different ways to define an average. Casually speaking, the “typical” value in the distribution can be roughly represented by these measures of center. Depending on the data and its distribution, one measure of center might be most informative or most representative of the “typical” value. In analyzing quantitative data, the measure of center will be one key component. Contributors and Attributions CC licensed content, Shared previously - Concepts in Statistics. Provided by : Open Learning Initiative. Located at : http://oli.cmu.edu . License : CC BY: Attribution	163	common-pile/libretexts_filtered	https://stats.libretexts.org/Courses/Lumen_Learning/Concepts_in_Statistics_(Lumen)/02%3A_Summarizing_Data_Graphically_and_Numerically/2.22%3A_Introduction_to_Measures_of_Center	libretexts	libretexts-0000.json.gz:50679	https://stats.libretexts.org/Courses/Lumen_Learning/Concepts_in_Statistics_(Lumen)/02%3A_Summarizing_Data_Graphically_and_Numerically/2.22%3A_Introduction_to_Measures_of_Center
kBY3vXROe4Qic_nu	The Wild Turkey and Its Hunting	Produced by Charlene Taylor, JoAnn Greenwood, and the Online Distributed Proofreading Team at http://www.pgdp.net Transcriber's Note: Obvious typographical errors have been repaired. _Underscores_ surround italicized text. [Illustration: The grandest bird of the American continent] THE WILD TURKEY AND ITS HUNTING BY EDWARD A. McILHENNY _Illustrated from Photographs_ GARDEN CITY NEW YORK DOUBLEDAY, PAGE & COMPANY 1914 _Copyright, 1912, 1913, 1914, by_ THE OUTDOOR WORLD PUBLISHING COMPANY _Copyright, 1914, by_ DOUBLEDAY, PAGE & COMPANY _All rights reserved, including that of translation into foreign languages, including the Scandinavian_ CONTENTS PAGE Introduction ix CHAPTER I. My Early Training with the Turkeys 3 II. Range, Variation, and Name 12 III. The Turkey Prehistoric 26 IV. The Turkey Historic 39 V. Breast Sponge--Shrewdness 104 VI. Social Relations--Nesting--The Young Birds 111 VII. Association of Sexes 119 VIII. Its Enemies and Food 134 IX. Habits of Association and Roosting 152 X. Guns I Have Used on Turkeys 163 XI. Learning Turkey Language--Why Does the Gobbler Gobble 170 XII. On Callers and Calling 181 XIII. Calling Up the Lovelorn Gobbler 198 XIV. The Indifferent Young Gobbler 213 XV. Hunting Turkey with a Dog 218 XVI. The Secret of Cooking the Turkey 233 XVII. Camera Hunting for Turkeys 238 LIST OF ILLUSTRATIONS The grandest bird of the American continent. _Frontispiece_ FACING PAGE Plate I. Figs. 1 to 5. Types: _M. antiqua_; _M. celer._ Marsh 30 Plate II. Figs. 6 to 10. Views of the skulls of wild turkeys 45 Plate III. Fig. 11. Left lateral view of the skull of an old male wild turkey 60 Plate IV. Figs. 12 to 16. Views of the cranium and skull of the turkey 75 Plate V. Figs. 17 to 19. Views of the skull of wild turkeys, and skeleton of the left foot of a wild turkey 80 Plate VI. Figs. 20 to 23. Eggs of wild turkey 90 Plate VII. Fig. 24. Nest of a wild turkey _in situ_ 102 Note the full chest of the gobbler on the left. This is the breast sponge 106 Nest located in thick brush on top of a ridge in Louisiana 112 Hen, wild turkey, and three young 116 The beginning of the strut 124 The chief of all his enemies is the "genus homo" 142 An ideal turkey country. They will go a long way to roost in trees growing in water 156 A hermit. It would take an expert turkey hunter to circumvent this bird 160 Big woods in Louisiana where the old gobblers roam at will. A delightful place in which to camp 174 Jordan's Turkey Call (cut in text) 183 I soon saw the old gobbler stealing slowly through the brush 190 "Cluck," "put," "put," there stands a gobbler, within twenty paces to the left 202 Suddenly there was a "Gil-obble-obble-obble," so near it made me jump 206 The soft, gentle quaver of the hen has no effect on the ear of the young gobbler 216 INTRODUCTION Although many eminent naturalists and observers have written of the turkey from the date of its introduction to European civilization to the present time, there has been no very satisfactory history of the intimate life of this bird, nor has there been a satisfactory analysis of either the material from which our fossil turkeys are known, or the many writings concerning the early history of the bird and its introduction to civilization. I have attempted in this work to cover the entire history of this very interesting and vanishing game bird, and believe it will fill a long-felt want of hunters and naturalists for a more detailed description of its life history. This work was begun by Chas. L. Jordan and would have been completed by him, except for his untimely death in 1909. Mr. Jordan for more than sixty years was a careful observer and lover of the wild turkey, and for many years the study of this bird occupied almost his entire time. I feel safe in saying that Mr. Jordan knew more of the ways of the wild turkey in the wilds than any man who ever lived. No more convincing example of his patience and perseverance in his study of the bird can be given than the accompanying photographs, all of which were taken of the wild birds in the big outdoors by Mr. Jordan. At the time of Mr. Jordan's death he was in his sixty-seventh year and was manager of the Morris game preserve of over 10,000 acres, near Hammond, La. He had been most successful in attracting to this preserve a great abundance of game, and was very active in suppressing poaching and illegal hunting. His activity in this cause brought about his death, as he was shot in the back by a poacher during the afternoon of February 24, 1909, for which Allen Lagrue, his murderer, is now serving a life sentence in the penitentiary. I had known Mr. Jordan for a number of years before his death and was much interested in his work with the turkey, as I, for years, had been carrying on similar studies. After Mr. Jordan's death, through the kindness of Mr. John K. Renaud, I secured his notes, manuscript, and photographic plates of the wild turkey, and with these, and my knowledge of the bird, I have attempted to compile a work I think he would have approved. Mr. Jordan from time to time wrote articles on the wild turkey for sporting magazines, among them _Shooting and Fishing_, and parts of his articles are brought into the present publication. I have carried out the story of the wild turkey as if told by Mr. Jordan, as his full notes on the bird enable me to do this. I am indebted to Dr. R. W. Shufeldt for his chapter on the fossil turkey, the introduction of the turkey to civilization, and photographs accompanying his two chapters, written at my request especially for this work. E. A. M. THE WILD TURKEY AND ITS HUNTING CHAPTER I MY EARLY TRAINING WITH THE TURKEYS My father was a great all-round hunter and pioneer in the state of Alabama, once the paradise of hunters. He was particularly devoted to deer hunting and fox hunting, owning many hounds and horses. He knew the ways and haunts of the forest people and from him my brothers and I got our early training in woodcraft. I was the youngest of three sons, all of whom were sportsmen to the manner born. My brothers and myself were particularly fond of hunting the wild turkey, and were raised and schooled in intimate association with this noble bird; the fondness for this sport has remained with me through life. I therefore may be pardoned when I say that I possess a fair knowledge of their language, their habits, their likes and dislikes. In the great woods surrounding our home there were numbers of wild turkeys, and I can well remember my brother Frank's skill in calling them. Every spring as the gobbling season approached my brothers and myself would construct various turkey calls and lose no opportunity for practising calling the birds. I can recall, too, when but a mere lad, coming down from my room in the early morning to the open porch, and finding assembled the family and servants, including the little darkies and the dogs, all in a state of great excitement. I hastened to learn the cause of this and was shown with admiration a big gobbler, and as I looked at the noble bird, with its long beard and glossy plumage, lying on the porch, I felt it was a beautiful trophy of the chase. "Who killed it?" I asked. "Old Massa, he kill 'im," came from the mouths of half a dozen excited little darkies. A few days later my brothers brought in other turkeys. This made me long for the time when I would be old enough to hunt this bird, and these happy incidents inspired me with ambition to acquire proficiency in turkey hunting, and to learn every method so that I might excel in that sport. As I grew older, but while still a mere lad, I would often steal to the woods in early morning on my way to school, and, hiding myself in some thick bush, sitting with my book in my lap and a rude cane joint or bone of a turkey's wing for a call in my hand, I would watch for the turkeys. When they appeared I would study every movement of the birds, note their call, yelp, cluck, or gobble, and I gradually learned each sound they made had its meaning. I would study closely the ways of the hens and their conduct toward the young and growing broods; I would also note their attention to the old or young gobblers, and the mannerisms of the male birds toward the females. All this time I would be using my call, attempting to imitate every note that the turkeys made, and watching the effect. These were my rudimentary and earliest lessons in turkey lore and lingo, and what I have often called my schooling with the turkeys. At this age I had not begun the use of a rifle or shotgun on turkeys, although I had killed smaller game, such as squirrels, rabbits, ducks, and quail. I was sixteen years of age when I began to hunt the wild turkeys. I discovered then that although I was able to do good calling I had much more to learn to cope successfully with the wily ways of this bird. It took years of the closest observation and study to acquire the knowledge which later made me a successful turkey hunter, and I have gained this knowledge only after tramping over thousands of miles of wild territory, through swamps and hummocks, over hills and rugged mountain sides, through deep gulches, quagmires, and cane brakes, and spending many hours in fallen treetops, behind logs or other natural cover, not to be observed, but to observe, by day and by night, in rain, wind, and storm. I have hunted the wild turkeys on the great prairies and thickets of Texas, along the open river bottoms of the Brazos, Colorado, Trinity, San Jacinto, Bernardo, as well as the rivers, creeks, hills, and valleys of Alabama, Florida, Mississippi, and Louisiana. With all modesty, I believe I have killed as many old gobblers with patriarchal beards as any man in the world. I do not wish to say this boastfully, but present it as illustrative of the experience I have had with these birds, and particularly with old gobblers, for I have always found a special delight in outwitting the wary old birds. I doubt not many veteran turkey hunters have in mind some old gobbler who seemed invincible; some bird that had puzzled them for three or four years without their learning the tricks of the cunning fellow. Perhaps in these pages there may be found some information which will enable even the old hunter to better circumvent the bird. I am aware that there are times when the keenest sportsmen will be outwitted, often when success seems assured. How well I know this. Many times I have called turkeys to within a few feet of me; so near that I have heard their "put-put." And they would walk away without my getting a shot. Often does this occur to the best turkey hunter, on account of the game approaching from the rear, or other unexpected point, and suddenly without warning fly or run away. No one can avoid this, but the sportsman who understands turkeys can exercise care and judgment and kill his bird, where others unacquainted with the bird fail. I believe I can take any man or boy who possesses a good eye and fair sense, and in one season make a good turkey hunter of him. I know of many nefarious tricks by which turkeys could be easily secured, but I shall not tell of any method of hunting and capturing turkeys but those I consider sportsmanlike. Although an ardent turkey hunter, I have too much respect for this glorious bird to see it killed in any but an honorable way. The turkey's fate is hard enough as it is. The work of destruction goes on from year to year, and the birds are being greatly reduced in numbers in many localities. The extinction of them in some states has already been accomplished, and in others it is only a matter of time; but there are many localities in the South and West, especially in the Gulf-bordering states, where they are still plentiful, and with any sort of protection will remain so. Some of these localities are so situated that they will for generations remain primeval forests, giving ample shelter and food to the turkey. A novice might think it an easy matter to find turkeys after seeing their tracks along the banks of streams or roads, or in the open field, where they lingered the day before. But these birds are not likely to be in the same place the following day; they will probably be some miles away on a leafy ridge, scratching up the dry leaves and mould in quest of insects and acorns, or in some cornfield gleaning the scattered grain; or perhaps they might be lingering on the banks of some small stream in a dense swamp, gathering snails or small crustacea and water-loving insects. To be successful in turkey hunting you must learn to rise early in the morning, ere there is a suspicion of daylight. At such a time the air is chilly, perhaps it looks like rain, and on awakening you are likely to yawn, stretch, and look at the time. Unless you possess the ardor of a sportsman it is not pleasant to rise from a comfortable bed at this hour and go forth into the chill morning air that threatens to freeze the marrow in your bones. But it is essential that you rise before light, and if you are a born turkey hunter you will soon forget the discomforts. It has been my custom, when intending to go turkey hunting, never to hesitate a moment, but, on awakening in the morning, bound out of bed at once and dress as soon as possible. It has also been my custom to calculate the distance I am to go, so as to reach the turkey range by the time or a little before day breaks. I have frequently risen at one or two o'clock in the morning and ridden twelve miles or more before daybreak for the chance to kill an old gobbler. Early morning from the break of day until nine o'clock is the very best time during the whole day to get turkeys; but the half hour after daybreak is really worth all the rest of the day; this is the time when everything chimes with the new-born day; all life is on the move; diurnal tribes awakening from night's repose are coming into action, while nocturnal creatures are seeking their retreats. Hence at this hour there is a conglomeration of animal life and a babel of mingled sounds not heard at any other time of day. This is the time to be in the depths of the forest in quest of the wild turkey, and one should be near their roosting place if possible, quietly listening and watching every sound and motion. If in the autumn or winter you are near such a place, you are likely to hear, as day breaks, the awakening cluck at long intervals; then will follow the long, gentle, quavering call or yelp of the mother hen, arousing her sleeping brood and making known to them that the time has arrived for leaving their roosts. If in the early spring, you will listen for the salutation of the old gobbler. CHAPTER II RANGE, VARIATION, AND NAME When America was discovered the wild turkey inhabited the wooded portion of the entire country, from the southern provinces of Canada and southern Maine, south to southern Mexico, and from Arizona, Kansas, and Nebraska, east to the Atlantic Ocean and the Gulf of Mexico. As the turkey is not a migratory bird in the sense that migration is usually interpreted, and while the range of the _species_ is one of great extent, as might be expected, owing to the operation of the usual causes, a number of _subspecies_ have resulted. At the present time, ornithologists recognize four of these as occurring within the limits of the United States, as set forth in Chapter IV beyond. In countries thickly settled, as in the one where I now write, there is a great variety of wild turkeys scattered about in the woods of the small creeks and hills. Many hybrid wild turkeys are killed here every year. The cause of this is: every old gobbler that dares to open its mouth to gobble in the spring is within the hearing of farmers, negroes, and others, and is a marked bird. It is given no rest until it is killed; hence there are few or no wild turkeys to take care of the hens, which then visit the domestic gobbler about the farm-yards. Hence this crossing with the wild one is responsible for a great variety of plumages. I once saw a flock of hybrids while hunting squirrels in Pelahatchie swamp, Mississippi, as I sat at the root of a tree eating lunch, about one o'clock, with gun across my lap, as I never wish to be caught out of reach of my gun. Suddenly I heard a noise in the leaves, and on looking in that direction I saw a considerable flock of turkeys coming directly toward me in a lively manner, eagerly searching for food. The moment these birds came in sight I saw they had white tips to their tails, but they had the form and action of the wild turkey, and it at once occurred to me that they were a lot of mixed breeds, half wild, half tame, with the freedom of the former. I noticed also among them one that was nearly white and one old gobbler that was a pure wild turkey; but it was too far off to shoot him. Dropping the lunch and grasping the gun was but the work of a second; then the birds came round the end of the log and began scratching under a beech tree for nuts. Seeing two gobblers put their heads together at about forty yards from me, I fired, killing both. The flock flew and ran in all directions. One hen passed within twenty paces of me and I killed it with the second barrel. A closer examination of the dead birds convinced me that there had been a cross between the wild and the tame turkeys. The skin on their necks and heads was as yellow as an orange, or more of a buckskin, buff color, while the caruncles on the neck were tinged with vermilion, giving them a most peculiar appearance; all three of those slain had this peculiar marking, and there was not a shadow of the blue or purple of the wild turkey about their heads, while all other points, save the white-tipped feathers, indicated the wild blood. Shortly after the foregoing incident, while a party of gentlemen, including my brother, were hunting some five miles below the same creek, they flushed a flock of wild turkeys, scattering them; one of the party killed four of them that evening, two of which (hens) were full-blood wild ones. One of the remaining two, a fine gobbler, had as red a head as any tame gobbler, and the tips of the tail and rump coverts were white. The other bird (a hen) was also a half-breed. There was no buff on their heads and necks, but the purple and blue of the wild blood was apparent. Early the next morning my brother went to the place where the turkeys were scattered the previous afternoon, and began to call. Very soon he had a reply, and three fine gobblers came running to him, when he killed two, one with each barrel; now these were full-blood wild ones. I have noted that a number of wild turkeys in the Brazos bottoms are very different in some respects from the turkeys of the piney woods in the eastern section of that state. In Trinity County, Texas, I found the largest breed of wild turkeys I have found anywhere, but in the Brazos bottoms the gobblers which I found there in 1876, in great abundance, were of a smaller stature, but more chunky or bulky. Their gobble was hardly like that of a wild turkey, the sound resembling the gobble of a turkey under a barrel, a hoarse, guttural rumble, quite different in tone from the clear, loud, rolling gobble of his cousin in the Trinity country. The gobblers of the Brazos bottoms were also distinguishable by their peculiar beards. In other varieties of turkeys three inches or less of the upper end of the beard is grayish, while those of the Brazos bottoms were more bunchy and black up to the skin of the breast. There is a variety of turkeys in the San Jacinto region, in the same state, which is quite slender, dark in color, and has a beard quite thin in brush, but long and picturesque. His gobble is shrill. This section is a low plain, generally wet in the spring, partly timbered and partly open prairie. It is a great place for the turkey. Since the days of Audubon it has been prophesied that the wild turkey would soon become extinct. I am glad to say that the prophecies have not been realized up to the present time, even with the improved implements of destruction and great increase of hunters. There is no game that holds its own so well as the wild turkey. This is particularly true in the southern Gulf States, where are to be found heavily timbered regions, which are suited to the habits of this bird. Here shelter is afforded and an ample food supply is provided the year round. In the states of Florida, Alabama, Mississippi, North Carolina, Georgia, Louisiana, Texas, Arkansas, Missouri, and the Indian Territory the wild turkey is still to be found in reasonable abundance, and if these states will protect them by the right sort of laws, I am of the opinion that the birds will increase rapidly, despite the encroachment of civilization and the war waged upon them by sportsmen. It is not the legitimate methods of destruction that decimate the turkey ranks, as is the case with the quail and grouse, but it is the nefarious tricks the laws in many states permit, namely, trapping and baiting. The latter is by far the most destructive, and is practised by those who kill turkeys for the market, and frequently by those who want to slaughter these birds solely for count. No creature, however prolific, can stand such treatment long. The quail, though shot in great numbers by both sportsmen and market hunters, and annually destroyed legitimately by the thousands, stands it better than the wild turkey, although the latter produces and raises almost as many young at a time as the quail. There are two reasons for this: one is, the quail are not baited and shot on the ground; the other reason is that every bobwhite in the spring can, and does, use his call, thus bringing to him a mate; but the turkey, if he dares to gobble, no matter if he is the only turkey within a radius of forty miles, has every one who hears him and can procure a gun, after him, and they pursue him relentlessly until he is killed. Among the turkeys the hens raised are greatly in excess of the gobblers. This fact seems to have been provided for by nature in making the male turkey polygamous; but as the male turkey is, during the spring, a very noisy bird, continually gobbling and strutting to attract his harem, and as he is much larger and more conspicuous than the hens, it is only natural that he is in more danger of being killed. Suppose the proportion of gobblers in the beginning of the spring is three to fifteen hens, in a certain stretch of woods. As soon as the mating season begins, these gobblers will make their whereabouts known by their noise; result--the gunners are after them at once, and the chances are ten to one they will all be killed. The hens will then have no mate and no young will be produced; whereas, if but one gobbler were left, each of our supposed fifteen hens would raise an average of ten young each, and we would also have 150 new turkeys in the fall to yield sport and food. It has always been my practice to leave at least one old gobbler in each locality to assist the hens in reproduction. If every hunter would do this the problem of maintaining the turkey supply would be greatly solved. The greatest of all causes for the decrease of wild turkeys lies in the killing of all the old gobblers in the spring. Some say the yearling gobblers will answer every purpose. I say they will not; they answer no purpose except to grow and make gobblers for the next year. The hens are all right--you need have no anxiety about them; they can take care of themselves; provided you leave them a male bird that gobbles, they will do the rest. Any suitable community can have all the wild turkeys it wants if it will obtain a few specimens and turn them into a small woodland about the beginning of spring, spreading grain of some sort for them daily. The turkeys will stay where the food is abundant and where there is a little brush in which to retire and rest. Some hunters, or rather some writers, claim that the only time the wild turkey should be hunted is in the autumn and winter, and not in the spring. I have a different idea altogether, and claim that the turkey should not be hunted before November, if then, December being better. By the first of November the young gobbler weighs from seven to nine pounds, the hens from four to seven pounds; in December and January the former weighs twelve pounds and the latter nine pounds. There you are. But suppose you did not hunt in the spring at all. How many old, long-bearded gobblers (the joy and delight above every sort of game on earth to the turkey hunter) would you bag in a year, or a lifetime? Possibly in ten years you would get one, unless by the merest accident, as they are rarely, if ever, found in company with the hens or young gobblers, but go in small bands by themselves, and from their exclusive and retiring nature it is a rare occasion when one is killed except in the gobbling season. Take away the delight of the gobbling season from the turkey hunter, and the quest of the wild turkey would lose its fascination. In so expressing myself, I do not advise that the gobblers be persecuted and worried all through the gobbling season, from March to June, but believe they could be hunted for a limited time, namely, until the hens begin to lay and the gobblers to lose their fat--say until the first of April. Every old turkey hunter knows where to stop, and does it without limitation of law. Old gobblers are in their best condition until about the first of April, then they begin to lose flesh very rapidly. At this time hunting them should be abandoned altogether. In my hunting trips after this bird I have covered most of the southern states, and have been interested to note that all the Indians I have met called the turkey "Furkee" or "Firkee"; the tribes I have hunted with include the Choctaws, Chickasaws, Creeks, Seminoles, and the Cherokees, who live east of the Mississippi River, and the Alabams, Conchattas, and Zunis of the west. Whether their name for the bird is a corruption of our turkey, or whether our word is a corruption of their "Furkee," I am not prepared to state. It may be that we get our name direct from the aboriginal Indians. All of the Indian tribes I have hunted with have legends concerning the turkey, and to certain of the Aztec tribes it was an object of worship. An old Zuni chief once told me a curious legend of his people concerning this bird, very similar to the story of the flood. It runs: Ages ago, before man came to live on the earth, all birds, beasts, and fishes lived in harmony as one family, speaking the same language, and subsisting on sweet herbs and grass that grew in abundance all over the earth. Suddenly one day the sun ceased to shine, the sky became covered with heavy clouds, and rain began to fall. For a long time this continued, and neither the sun, moon, nor stars were seen. After a while the water got so deep that the birds, animals, and fishes had either to swim or fly in the air, as there was no land to stand on. Those that could not swim or fly were carried around on the backs of those that could, and this kept up until almost every living thing was almost starved. Then all the creatures held a meeting, and one from each kind was selected to go to heaven and ask the Great Spirit to send back the sun, moon, and stars and stop the rain. These journeyed a long way and at last found a great ladder running into the sky; they climbed up this ladder and found at the top a trapdoor leading into heaven, and on passing through the door, which was open, they saw the dwelling-place of man, and before the door were a boy and girl playing, and their playthings were the sun, moon, and stars belonging to the earth. As soon as the earth creatures saw the sun, moon, and stars, they rushed for them and, gathering them into a basket, took the children of man and hurried back to earth through the trapdoor. In their hurry to get away from the man whom they saw running after them, the trapdoor was slammed on the tail of the bear, cutting it off. The blood spattered over the lynx and trout, and since that time the bear has had no tail, and the lynx and trout are spotted. The buffalo fell down and hurt his back and has had a hump on it ever since. The sun, moon, and stars having been put back in their places, the rain stopped at once and the waters quickly dried up. On the first appearance of land, the turkey, who had been flying around all the time, lit, although warned not to do so by the other creatures. It at once began to sink in the mud, and its tail stuck to the mud so tight that it could hardly fly up, and when it did get away the end of its tail was covered with mud and is stained mud color to this day. The earth now having become dry and the children of man now lords of the earth, each creature was obliged to keep out of their way, so the fishes took to the waters using their tails to swim away from man, the birds took to their wings, and the animals took to their legs; and by these means the birds, beasts, and fishes have kept out of man's way ever since. Before dealing with the wild turkeys as they are to-day, it will be well to make a short study of their prehistoric and historic standing; this has been ably done for me by Dr. R. W. Shufeldt of Washington, D. C., who has very kindly written for this work the next two chapters entitled "The Turkey Prehistoric," and "The Turkey Historic." THE TURKEY PREHISTORIC Probably no genus of birds in the American avifauna has received the amount of attention that has been bestowed upon the turkeys. Ever since the coming to the New World of the very first explorers, who landed in those parts where wild turkeys are to be found, there has been no cessation of verbal narratives, casual notices, and appearance of elegant literature relating to the members of this group. We have not far to seek for the reason for all this, inasmuch as a wild turkey is a very large and unusually handsome bird, commanding the attention of any one who sees it. Its habits, extraordinary behavior, and notes render it still more deserving of consideration; and to all this must be added the fact that wild turkeys are magnificent game birds; the hunting of them peculiarly attractive to the sportsman; while, finally, they are easily domesticated and therefore have a great commercial value everywhere. The extensive literature on wild and domesticated turkeys is by no means confined to the English language, for we meet with many references to these fowls, together with accounts and descriptions of them, distributed through prints and publications of various kinds, not only in Latin, but in the Scandinavian languages as well as in French, German, Spanish, Italian, and doubtless in others of the Old World. Some of these accounts appeared as long ago as the early part of the sixteenth century, or perhaps even earlier; for it is known that Grijalva discovered Mexico in 1518, and Gomarra and Hernandez, whose writings appeared soon afterward, gave, among their descriptions of the products of that country, not only the wild turkey, but, in the case of the latter writer, referred to the wild as well as to the domesticated form, making the distinction between the two. In order, however, to render our history of the wild turkeys in America as complete as possible, we must dip into the past many centuries prior to the discovery of the New World by those early navigators. We must go back to the time when it was questionable whether man existed upon this continent at all. In other words, we must examine and describe the material representing our extinct turkeys handed us by the paleontologists, or the fossilized remains of the prehistoric ancestors of the family, of which we have at hand a few fragments of the greatest value. These I shall refer to but briefly for several reasons. In the first place, their technical descriptions have already appeared in several widely known publications, and in the second, what I have here to say about them is in a popular work, and technical descriptions are not altogether in place. Finally, such material as we possess is very meagre in amount indeed, and such parts of it as would in any way interest the general reader can be referred to very briefly. The fossil remains of a supposed extinct turkey, described by Marsh[1] as _Meleagris altus_ from the Post-pliocene of New Jersey, is, from the literature and notices on the subject, now found to be but a synonym of the _Meleagris superba_ of Cope from the Pleistocene of New Jersey. At the present writing I have before me the type specimen of _Meleagris altus_ of Marsh, for which favor I am indebted to Dr. Charles Schuchert of the Peabody Museum of Yale University. My account of it will be published in another connection later on. Some years after Professor Marsh had described this material as representing a species to which I have just said he gave the specific name of _altus_, it would appear that I did not fully concur in the propriety of doing so, as will be seen from a paper I published on the subject about fifteen years ago[2]. This will obviate the necessity of saying anything further in regard to _M. superba_. So far as my knowledge carries me, this leaves but two other fossil wild turkeys of this country, both of which have been described by Professor Marsh and generally recognized. These are _Meleagris antiqua_ in 1871, and _Meleagris celer_ in 1872. My comments on both of these species will be found in the _American Naturalist_ for July, 1897, on pages 648, 649.[3] [Illustration: PLATE I Types: _M. antiqua_; _M. celer_. Marsh Fig. 1. Anconal aspect of the distal extremity of the right humerus of "_Meleagris antiquus_" of Marsh. Fig. 2. Palmar aspect of the same specimen shown in Fig. 1. Fig. 3. Anterior aspect of the proximal moiety of the left tarso-metatarsus of _Meleagris celer_ of Marsh. Fig. 4. Posterior aspect of the same fragment of bone shown in Fig. 3. Fig. 5. Outer aspect of the same fragment of bone shown in Figs. 3 and 4. All figures natural size. Reproduced from photographs made _direct_ from the specimens by Dr. R. W. Shufeldt.] It will be noted, then, that _Meleagris antiqua_ of Marsh is practically represented by the _imperfect_ distal extremity of a right humerus; and that _Meleagris celer_ of the same paleontologist from the Pleistocene of New Jersey is said to be represented by the bones enumerated in a foregoing footnote. In this connection let it be borne in mind that, while I found fossil specimens of _Meleagris g. silvestris_ in the bone caves of Tennessee, I found no remains of fossil turkeys in Oregon, from whence some classifiers of fossil birds state that _M. antiqua_ came (A. O. U. Check-Listed, 1910, p. 388[4]). On the 19th of April 1912, I communicated by letter with Dr. George F. Eaton, of the Museum of Yale University, in regard to the fossils described by Marsh of _M. antiqua_ and _M. celer_, with the view of borrowing them for examination. Dr. Eaton, with great kindness, at once interested himself in the matter, and wrote me (April 20, 1912) that "We have a wise rule forbidding us to lend type material, but I shall be glad to ask Professor Schuchert to make an exception in your favor." In due time Prof. Charles Schuchert, then curator of the Geological Department of the Peabody Museum of Natural History of Yale University, wrote me on the subject (May 2, 1912), and with marked courtesy granted the request made of him by Dr. Eaton, and forwarded me the type specimen of Marsh of _M. antiqua_ and _M. celer_ by registered mail. They were received on the 3rd of May, 1912, and I made negatives of the two specimens on the same day. It affords me pleasure to thank both Professor Schuchert and Dr. Eaton here for the unusual privilege I enjoyed, through their assistance, in the loan of these specimens;[5] also Dr. James E. Benedict, Curator of Exhibits of the U. S. National Museum, and Dr. Charles W. Richmond of the Division of Birds of that institution, for their kindness in permitting me to examine and make notes upon a mounted skeleton of a wild turkey (_M. g. silvestris_) taken by Prof. S. F. Baird at Carlisle, Penn., many years ago. Mr. Newton P. Scudder, librarian of the National Museum, likewise has my sincere thanks for his kindness in placing before me the many volumes on the history of the turkey I was obliged to consult in connection with the preparation of this chapter. From what has already been set forth above, it is clear that Marsh's specimen (for he attached but scant importance to the _other fragments_ with it), upon which he based "_Meleagris antiquus_" was not taken in Oregon, but in Colorado.[6] Both of these fossils I have very critically compared with the corresponding parts of the bones represented in each case in the skeleton of an adult wild turkey (_Meleagris g. silvestris_) in the collection of mounted bird skeletons in the U. S. National Museum. Taking everything at my command into consideration as set forth above, as well as the extent of Professor Marsh's knowledge of the osteology of existing birds--not heretofore referred to--I am of the opinion, that in the case of his _Meleagris antiqua_, the material upon which it is based is altogether too fragmentary to pronounce, with anything like certainty, that it ever belonged to a turkey at all. In the first place, it is a very _imperfect_ fragment (Plate 1, Figs. 1 and 2); in the second, it does not typically present the "characteristic portions" of that end of the humerus in a turkey, as Professor Marsh states it does. Thirdly, the distal end of the humerus is by no means a safe fragment of the skeleton of hardly any bird to judge from. Finally, it is questionable whether the genus _Meleagris_ existed at all, as such, at the time the "Miocene clay deposits of northern Colorado" were deposited. That this fragment may have belonged to the skeleton of some big gallinaceous fowl the size of an adult existing _Meleagris_--and long ago extinct--I in no way question; but that it was a _true turkey_, I very much doubt. Still more uncertain is the fragment representing _Meleagris celer_ of Marsh. (Plate 1, Figs. 3-5.) The tibia mentioned I have not seen, and of them Professor Marsh states that they only "probably belonged to the same individual" (see _antea_). As to this proximal moiety of the tarso-metatarsus, it is essentially different from the corresponding part of that bone in _Meleagris g. silvestris_. In it the _hypotarsus_ is twice grooved, longitudinally; whereas in _M. g. silvestris_ there is but a single median groove. In the latter bird there is a conspicuous osseous ridge extending far down the shaft of the bone, it being continued from the internal, thickened border of the hypotarsus. This ridge is only _indicated_ on the fossil bone, having either been broken off or never existed at all. In any event it is not present in the specimen. The general _facies_ of the fossil is quite different from that part of the tarso-metatarsus in an existing wild turkey, and to me it does not seem to have come from the skeleton of the pelvic limb of a meleagrine fowl at all. It may have belonged to a bird of the galline group, not essentially a turkey; while on the other hand it may have been from the skeleton of some large wader, not necessarily related to either the true herons or storks. Some of the herons, for example, (_Ardea_) have "the hypotarsus of the tarso-metatarsus three-crested, graduated in size, the outer being the smaller; the tendinal grooves pass between them."[7] As just stated, the hypotarsus of the tarso-metatarsus in _Meleagris celer_ of Marsh is three-crested, and the tendinal grooves pass between them. In _M. g. silvestris_ this process is but two-crested and the median groove passes between them. The _sternum_ of the turkey, if we have it practically complete, is one of the most characteristic bones of the skeleton; but Professor Marsh had no such material to guide him when he pronounced upon his fossil turkeys. Had I made new species, based on the fragments of fossil long bones of all that I have had for examination, quite a numerous little extinct avifauna would have been created. "It is often a positive detriment to science, in my opinion, to create new species of fossil birds upon the distal ends of long bones, and surely no assistance whatever to those who honestly endeavor to gain some idea of the avian species that really existed during prehistoric times."[8] FOOTNOTES: [1] Marsh, O. C. Proc. Acad. Nat. Sci., Phila., 1870, p. 11. Also Am. Jour. Sci., IV, 1872, 260. In a letter to me under date of April 25, 1912, Dr. George F. Eaton of the Museum of Yale University, New Haven, Conn., writes that "Type of _Meleagris altus_ is in Peabody Museum with other types of fossil _Meleagris_." At the present writing I am not informed as to what these "other types" are; and I am writing of the opinion that the museum referred to by Doctor Eaton has no fossil meleagrine material that has not, up to date, been described. See also Amer. Nat., Vol. IV, p. 317. Cope, E. D. "Synopsis of Extinct Batrachia, etc." _Meleagris superbus_ (Trans. Amer. Philos. Soc., N. S. XIV, Pt. 1, 1870, 239). A long and careful description of _M. superbus_ [superba] will be found here, where the species is said to be "established on a nearly perfect right tibia, an imperfect left one, a left femur with the condyles broken off, and a light coracoid bone, with the distal articular extremity imperfect." [2] Shufeldt, R. W., "On Fossil Bird-Bones Obtained by Expeditions of the University of Pennsylvania from the Bone Caves of Tennessee." The Amer. Nat., July, 1897, pp. 645-650. Among those bones were many belonging to _M. g. silvestris_. Professor Marsh declined to allow me to even see the fossil bones upon which he based the several alleged new species of extinct _Meleagridæ_ which he had described. [3] Marsh, O. C. [Title on page 120.] _Meleagris antiqua._ Amer. Journ. Sci., ser. 3, II, 1871, 126. From this I extract the following description, to wit:-- _Meleagris antiquus_, sp. nov. A large Gallinaceous Bird, approaching in size the wild Turkey, and probably belonging to the same group, was a contemporary of the _Oreodon_ and its associates during the formation of the Miocene lake deposits east of the Rocky Mountains. The species is at present represented only by a few fragments of the skeleton, but among these is a distal end of a right humerus, with the characteristic portions all preserved. The specimen agrees in its main features with the humerus of _Meleagris gallopavo_ Linn., the most noticeable points of difference being the absence in the fossil species of the broad longitudinal ridge on the inner surface of the distal end, opposite the radial condyle, and the abrupt termination of the ulnar condyle at its outer, superior border. Measurements Greatest diameter of humerus at distal end 12. lines Transverse diameter of ulnar condyle 3.4 " Vertical diameter of same 4. " Transverse diameter of radial condyle 4.25 " The specimens on which this species is based were discovered by Mr. G. B. Grinnell of the Yale party, in the Miocene clay deposits of northern Colorado. _Ibid._ IV, 1878, 261. [Title on p. 256.] "Art XXX. Notice of some new Tertiary and Post-Tertiary Birds." From this article by Professor Marsh I extract the following: _Meleagris celer_, sp. nov. A much smaller species of the same genus is represented by two tibiae and the proximal half of a tarso-metatarsal, which were found together, and probably belonged to the same individual. The tibia is slender, and has the shaft less flattened from before backward than in the last species [_M. altus_]. The distal half of the shaft has its anterior face more distinctly polygonal. From the head of the tibia a sharp ridge descends a short distance on the posterior face, where it is met by an external ridge of similar length. The tarso-metatarsal has the external ridge of the proximal end more prominent, and the posterior tendinal crest more ossified than in the larger species. The remains preserved indicate a bird about half the bulk of _M. altus_. Measurements. Length of tibia 183. mm Greatest diameter of proximal end 34. " Transverse diameter of shaft at middle 9.6 " Transverse diameter of distal end 16.5 " Antero-posterior diameter of outer condyle 10. " Transverse diameter of proximal end of tarso-metatarsus 19. " Antero-posterior diameter 14. " On page 260 is described _Meleagris altus_: _Meleagris altus_ [Marsh]. Proc. Phila. Acad. 1870, p. 11, and Amer. Nat., Vol. IV, p. 317. (_M. superbus_ Cope, Synopsis Extinct Batrachia etc., p. 239.) (Followed by description and the following measurements of the fossil bones.) Length (approx.) of humerus 159.5 mm Greatest diameter proximal end 42. " Greatest diameter distal end 33. " Length of coracoid 122. " Transverse diameter of lower end 37.5 " Length of femur 150. " Transverse diameter of distal end 31. " Length of tibia 243. " Transverse diameter of distal end 18. " Length of tarso-metatarsus 176. " Transverse diameter of proximal end 23. " Distance from proximal end to spur 110. " (A number of differences as compared with existing species are enumerated) [4] Shufeldt, R. W. A Study of the Fossil Avifauna of the Equus Beds of the Oregon Desert. Journ. Acad. Nat. Sci., Phila., ser. 2, IX, 1892, pp. 389-425. Pls. XV-XVII. Advance abstracts of this memoir were published in The Auk (Vol. VIII, No. 4, October, 1891, pp. 365-368). The American Naturalist (Vol. XXV, No. 292, Apr., 1891, pp. 303-306, and _ibid._ No. 297, Sept., 1891, pp. 818-821) and elsewhere. Although no turkeys were discovered among these fossils, there were bones present of extinct grouse. [5] Upon examining this material after it came into my hands, I found first, in a small tube closed with a cork, the distal end of the right humerus of some large bird. The cork was marked on the side, "Type," on top "_Mel. antiquus_. G. Ranch. Col. G. B. G. August 6, 1870." The specimen is pure white, thoroughly fossilized, and imperfect. The second of the two specimens received is in a small pasteboard box, marked on top "Birds. Meleagris, sp. nov. N. J., _Meleagrops celer_ (type)." The specimen is the imperfect, proximal moiety of the left tarso-metatarsus of a rather large bird. It is thoroughly fossilized, earth-brown in color, with the free borders of the proximal end considerably worn off. On its postero-external aspect, written in ink, are the words "_M. celer_." [6] In making this statement, I take the words of Dr. Geo. Bird Grinnell as written on the cork of the bottle containing the specimen to be correct, and not the locality given elsewhere. (The A. O. U. Check-List of North American Birds. Third Edition, 1910, p. 388.) Moreover, the specimen is pure white, which is characteristic of the fossils found in the White River region of Colorado. This is confirmed by Professor Marsh in his article quoted above. [7] Shufeldt, R. W. "Osteological Studies of the Subfamily Ardeinæ." Journ. Comp. Med. and Surg., Vol. X, No. 4, Phila., October, 1889, pp. 287-317. [8] Shufeldt, R. W. Amer. Nat, July. 1897. p. 648. I have had no occasion to change my opinion since. CHAPTER IV THE TURKEY HISTORIC Having disposed of such records as we have of the extinct ancestors of the American turkeys--the so-to-speak meleagrine records--we can now pass to what is, comparatively speaking, the modern history of these famous birds, although some of this history is already several centuries old. We have seen in the foregoing chapter that all the described fossil species of turkeys have been restricted to the genus _Meleagris_, and this is likewise the case with the existing species and subspecies. Right here I may say that the word _Meleagris_ is Greek as well as Latin, and means a guinea-fowl. This is due to the fact that when turkeys were first described and written about they were, by several authors of the early times, strangely mixed up with those African forms, and the two were not entirely disentangled for some time, as we shall see further on in this chapter. In modern ornithology, however, the generic name of _Meleagris_ has been transferred from the guinea-fowls to the turkeys. These last, as they are classified in "The A. O. U. Check-List of the American Ornithologists' Union," which is the latest authoritative word upon the subject, stand as follows: Family MELEAGRIDÆ. Turkeys. Genus MELEAGRIS Linnæus. _Meleagris_ Linnæus, Syst. Nat., ed. 10, 1, 1758, 156. Type, by subs, desig., _Meleagris gallopavo_ Linnæus (Gray, 1840). _Meleagris gallopavo_ (Linnæus). Range.--Eastern and south central United States, west to Arizona and south to the mountains of Oaxaca. a. [Meleagris gallopavo gallopavo. Extralimital.] b. Meleagris gallopavo silvestris Vieillot. Wild Turkey [310_a_]. _Meleagris silvestris_ Vieillot Nouv., Dict. d'Hist. Nat., IX, 1817, 447. Range.--Eastern United States from Nebraska, Kansas, western Oklahoma, and eastern Texas east to central Pennsylvania, and south to the Gulf coast; formerly north to South Dakota, southern Ontario, and southern Maine. c. Meleagris gallopavo merriami Nelson. Merriam's Turkey [310]. _Meleagris gallopavo merriami_ Nelson, Auk, XVII, April, 1900, 120. (47 miles southwest of Winslow, Arizona.) Range.--Transition and Upper Sonoran zones in the mountains of southern Colorado, New Mexico, Arizona, western Texas, northern Sonora, and Chihuahua. d. Meleagris gallopavo osceola Scott. Florida Turkey [310_b_]. _Meleagris gallopavo osceola_ Scott, Auk, VII, Oct., 1890, 376. (Tarpon Springs, Florida.) Range.--Southern Florida. e. Meleagris gallopavo intermedia Sennett. Rio Grande Turkey [310_c_]. _Meleagris gallopavo intermedia_ Sennett. Bull. U. S. Geol. & Geog. Surv. Terr., V, No. 3, Nov., 1879, 428. (Lomita, Texas.) Range.--Middle northern Texas south to northeastern Coahuila, Nuevo Leon, and Tamaulipas. The presenting of the above list here does away with giving, in the history of the wild turkeys, any of the very numerous changes that have taken place through the ages which led up to its adoption. The discussion of these changes, as a part of meleagrine history, would make an octavo volume of two hundred pages or more. It may be said here, however, that the word _gallopavo_ is from the Latin, _gallus_ a cock, and _pavo_ a peafowl, while the meanings of the several words _silvestris_, _merriami_, _osceola_, and _intermedia_ are self-evident and require no definitions. Audubon, who gives the breeding range of the wild turkey as extending "from Texas to Massachusetts and Vermont" (Vol. V., p. 56), says of them in his long account: "I have ascertained that some of these valuable birds are still to be found in the states of New York, Massachusetts, Vermont, and Maine. In the winter of 1832-33, I purchased a few fine males in the city of Boston"; and further, "At the time when I removed to Kentucky, rather more than a fourth of a century ago, turkeys were so abundant that the price of one in the market was not equal to that of a common barn-fowl now. I have seen them offered for the sum of three pence each, the birds weighing from ten to twelve pounds. A first-rate turkey, weighing from twenty-five to thirty pounds avoirdupois, was considered well sold when it brought a quarter of a dollar."[9] From these remarks we may imagine how plentiful wild turkeys must have been on the North American continent, when Aristotle wrote his work "On Animals," over three hundred years before the birth of Christ, upward of twenty-three centuries ago! A good many changes can take place in the avifauna of a country in that time. How these big, gallinaceous fowls ever got the name of "turkey" has long been a matter of dispute; and not a few ornithologists and writers of note in the 16th and 17th centuries erroneously conceived that the term had something to do either with the Turks or their country. But this idea has now been entirely abandoned, for it has become quite clear that, during the times mentioned, the turkey was strangely confused with the guinea-fowl, a bird to which the name turkey was originally applied. Later on, both these birds became more abundant, as more of them were domesticated and reared in captivity, and the fact was gradually realized that they were entirely different species of fowls. During these times, the word turkey was finally applied only to the New World species, and the West African form was thereafter called "Guinea-fowl."[10] After the word turkey was more generally applied to the bird now universally so known, some believe that there was another reason as to how it came about, and this "possibly because of its reputed call-note," says Newton, "to be syllabled _turk, turk, turk_, whereby it may be almost said to have named itself." (Notes and Queries, ser. 6, III, pp. 23, 369.)[11] [Illustration: PLATE II Fig. 6. Superior view of the skull of an old male wild turkey; lower jaw removed. No. 9695, Coll. U. S. National Museum. Fig. 7. Lower jaw or mandible of the skull shown in Fig. 6., seen from above. Fig. 8. Superior view of a skull of a wild turkey and probably a female. Lower jaw removed and shown in Fig. 9. No. 19684, Coll. U. S. National Museum. Fig. 9. Lower jaw of the skull shown in Fig. 8. Superior aspect. Fig. 10. Upper view of the skull of a wild Florida turkey (_Meleagris g. osceola_); lower jaw removed and not figured. Female. No. 18797, Coll. U. S. National Museum. All the figures in this plate are reproductions of photographs of the specimens made natural size by Dr. Shufeldt. Reduced about one-fourth.] So much for the origin of the name _turkey_; and when one comes to search through the literature devoted to this fowl to ascertain who first described the wild species, the opinion seems to be pretty general that this was done by Oviedo in the thirty-sixth chapter of his "Summario de la Natural Historia de las Indias," which it is stated appeared about the year 1527. Professor Spencer F. Baird, apparently quoting Martin, says: "Oviedo speaks of the turkey as a kind of peacock abounding in New Spain, which had already in 1526 been transported in a domestic state to the West India Islands and the _Spanish Main_, where it was kept by the Christian colonists."[12] In an elegant and comprehensive article on "The Wild Turkey," Bennett states: "Oviedo, whose Natural History of the Indies contains the earliest description extant of the bird, and whose acquaintance with the animal productions of the newly discovered countries was surprisingly extensive. He speaks of it as a kind of Peacock found in New Spain, of which a number had been transported to the islands of the Spanish Main, and domesticated in the houses of the Christian inhabitants. His description is exceedingly accurate, and proves that before the year 1526, when his work was published at Toledo, the turkey was already reduced to a state of Domestication."[13] Again, in a very elaborate and now thoroughly classical contribution, Pennant states: "The first precise description of these birds is given by Oviedo, who, in 1525, drew up a summary of his greater work, the History of the Indies, for the use of his monarch Charles V.[14] This learned man had visited the West Indies and its islands in person, and paid particular regard to the natural history. It appears from him, that the Turkey was in his days an inhabitant of the greater islands and of the mainland. He speaks of them as Peacocks; for being a new bird to him, he adopts that name from the resemblance he thought they bore to the former. 'But,' says he, 'the neck is bare of feathers, but covered with a skin which they change after their phantasie into diverse colours. They have a horn (in the Spanish Peçon corto) as it were on their front, and hairs on the breast.' (In Purchas, III, 995.) He describes other birds which he also calls Peacocks. They are of the gallinaceous genus, and known by the name of Curassao birds, the male of which is black, the female ferruginous."[15] Dr. Coues, who has also written an article on the history of the wild turkey, which, by the way, is mainly composed of a lengthy quotation from the above cited article of Bennett's, says: "Linnæus, however, knew perfectly well that the turkey was American. He says distinctly: 'Habitat in America septentrionali,' and quotes as his first reference (after Fn. Soec. 198), the _Gallopavo sylvestris novæ angliæ_, or New England Wild Turkey of Ray. Brisson distinguished the two perfectly, giving an elaborate description, a copious synonomy, and a good figure of each; and from about this time it may be considered that the history of the two birds, so widely diverse, was finally disentangled, and the proper habitat ascribed to each." (Refers to first describers of the pintado and turkey.)[16] So much for the earliest describers of the wild turkey, and I shall now pass on to the general history of the bird, and, through presenting what has been collected for us by the best authors on the subject, endeavor to show how, after the wild turkey was found in America by different navigators and explorers, it was brought, from time to time, to several of the countries of the Old World--chiefly Spain and Great Britain--from whence it probably was taken, upon different occasions, into other countries of the continent. Wild turkeys have always been easy to capture, and we are aware of the fact that they are quite capable of crossing the Atlantic on shipboard in comfort and safety, landing in as good a condition--if properly cared for during the voyage--as when they left America. Josselyn (1672) in his _New England Rarities_ (p. 9) has not a little to say on this point. As already stated, the literature and bibliography of the turkey is quite sufficient to fill a good many volumes. Nothing of importance, however, has been added to it, gainsaying what we now have as a truthful account of the bird's introduction into Europe. Indeed Buffon (Ois, II, pp. 132-162), Broderip (_Zool. Recreat._ pp. 120-137), Pennant (_Arct. Zool._ pp. 291-300), and others, practically cleared up nearly all the points on this part of the turkey's history, making but a few statements that are not wholly reliable and worthy of acceptance. Pennant very properly ignored in his work Barrington's essay (_Miscellanies_, pp. 127-151) in which the latter attempted to prove that turkeys were known before America was discovered, and that they were shipped over there subsequently to its discovery! I have already cited above Pennant's article in the Philosophical Transactions of the Royal Society of London (1781), and quoted from it to some extent. It is one of the standard writings on the wild turkey invariably referred to by all authors when writing on the history of that bird. As it is only accessible to the few, and so full of reliable information, I propose to give here, somewhat in full, those paragraphs in it having special reference to the historical side of our subject, and in doing so I retain the spelling and composition of the original production. "Belon, ('Hist. des Oys.,' 248) the earliest of those writers," says Pennant, "who are of the opinion that these birds were natives of the old world, founds his notion on the description of the Guinea-fowl, the Meleagrides of Strabo, Athenæus, Pliny, and others of the ancients. I rest the refutation on the excellent account given by Athenæus, taken from Clytus Milesius, a disciple of Aristotle, which can suit no other than that fowl. 'They want,' says he, 'natural affection towards their young; their head is naked, and on the top is a hard round body like a peg or nail; from their cheeks hangs a red piece of flesh like a beard. It has no wattles like the common poultry. The feathers are black, spotted with white. They have no spurs; and both sexes are so alike as not to be distinguished by the sight.' Varro (Lib. III. c. 9.) and Pliny (Lib. X. c. 26) take notice of the spotted plumage and the gibbous substance on the head. Athenæus is more minute, and contradicts every character of the Turkey, whose females are remarkable for their natural affection, and differ materially in form from the males, whose heads are destitute of the callous substance, and whose heels (in the males) are armed with spurs." "Aldrovandus, who died in 1605, draws his arguments from the same source as Belon; I therefore pass him by, and take notice of the greatest of our naturalists Gesner (Av. 481.), who falls into a mistake of another kind, and wishes the Turkey to be thought a native of India. He quotes Ælian for that purpose, who tells us, 'That in India are very large poultry not with combs, but with various coloured crests interwoven like flowers, with broad tails either bending or displayed in a circular form, which they draw along the ground as peacocks do when they do not erect them; and that the feathers are partly of a gold colour, partly blue, and of an emerald colour.' (De Anim. lib. XVI, c. 2.). "This in all probability was the same bird with the Peacock Pheasant of Mr. Edwards, _Le Baron de Tibet_ of M. Brisson, and the _Pavo bicalcaratus_ of Linnæus. I have seen this bird living. It has a crest, but not so conspicuous as that described by Ælian; but it has not those striking colours in form of eyes, neither does it erect its tail like the Peacock (Edw. II. 67.), but trails it like the Pheasant. The _Catreus_ of Strabo (Lib. XV. p. 1046) seems to be the same bird. He describes it as uncommonly beautiful and spotted, and very like a Peacock. The former author (De Anim. lib. XVII, c. 23.) gives more minute account of this species, and under the same name. He borrows it from Clitarchus, an attendant of Alexander the Great in all his conquests. It is evident from his description that it was of this kind; and it is likewise probable that it was the same with his large Indian poultry before cited. He celebrates it also for its fine note; but allowance must be made for the credulity of Ælian. "The _Catreus_, or Peacock Pheasant, is a native of Tibet, and in all probability of the north of India, where Clitarchus might have observed it; for the march of Alexander was through that part which borders on Tibet, and is now known by the name of Penj-ab or five rivers." "I shall now collect from authors the several parts of the world where Turkies are unknown in the state of nature. Europe has no share in the question; it being generally agreed that they are exotic in respect to that continent." "Neither are they found in any part of Asia Minor, or the Asiatic Turkey, notwithstanding ignorance of their true origin first caused them to be named from that empire. About Aleppo, capital of Syria, they are only met with, domesticated like other poultry. (Russel, 63). In Armenia they are unknown, as well as in Persia; having been brought from Venice by some Armenian merchants into that empire (Tavernier, 145), where they are still so scarce as to be preserved among other rare fowls in the royal menagery" (Bell's Travels, I. 128). "Du Halde acquaints us that they are not natives of China; but were introduced there from other countries. He errs from misinformation in saying that they are common in India." "I will not quote Gemelli Careri, to prove that they are not found in the Philippine Islands, because that gentleman with his pen traveled round the world in his easy chair, during a very long indisposition and confinement, (Sir James Porter's Obs. Turkey, I, 1, 321), in his native country." "But Dampier bears witness that none are found in Mindanao" (Barbot in Churchill's Coll., V. 29). "The hot climate of Africa barely suffers these birds to exist in that vast continent, except under the care of mankind. Very few are found in Guinea, except in the hands of the Europeans, the negroes declining to breed any on account of the great heats (Bosman, 229). Prosper Alpinus satisfies us they are not found either in Nubia or in Egypt. He describes the Meleagrides of the ancients, and only proves that the Guinea hens were brought out of Nubia, and sold at a great price at Cairo (Hist. Nat. Ægypti. I, 201); but is totally silent about the turkey of the moderns." "Let me in this place observe that the Guinea hens have long been imported into Britain. They were cultivated in our farm-yards; for I discover in 1277, in the Grainge of Clifton, in the parish of Ambrosden in Buckinghamshire, among other articles, six _Mutilones_ and six _Africanæ foeminæ_ (Kennett's Parochial Antiq. 287), for this fowl was familiarly known by the names of Afra Avis and Gallina Africana and Numida. It was introduced into Italy from Africa, and from Rome into our country. They were neglected here by reason of their tenderness and difficulty of rearing. We do not find them in the bills of fare of our ancient feasts (neither in that of George Nevil nor among the delicacies mentioned in the Northumberland household book begun in the beginning of the reign of Henry VIII); neither do we find the turkey; which last argument amounts almost to a certainty, that such a hardy and princely bird had not found its way to us. The other likewise was then known by its classical name; for that judicious writer Doctor Caius describes in the beginning of the reign of Elizabeth, the Guinea-fowl, for the benefit of his friend Gesner, under the name of Meleagris, bestowed on it by Aristotle" (CAII Opusc. 13. Hist. An., lib. VI. c. 2). "Having denied, on the very best authorities, that the Turkey ever existed as a native of the old world, I must now bring my proofs of its being only a native of the new, and of the period in which it first made its appearance in Europe." "The next who speaks of them as natives of the mainland of the warmer parts of America is Francusco Fernandez, sent there by Philip II, to whom he was physician. This naturalist observed them in Mexico. We find by him that the name of the male was Huexolotl, of the female Cihuatotolin. He gives them the title of Gallus Indicus and Gallo Pavo. The Indians, as well as the Spaniards, domesticated these useful birds. He speaks of the size by comparison, saying that the wild were twice the magnitude of the tame; and that they were shot with arrows or guns (Hist. Av. Nov. Hisp. 27). I cannot learn the time when Fernandez wrote. It must be between the years 1555 and 1598, the period of Philip's reign." "Pedro de Ciesa mentions Turkies on the Isthmus of Darien (Seventeen Years Travels, 20). Lery, a Portuguese author, asserts that they are found in Brazil, and gives them an Indian name (In De Laet's Descr. des Indes, 491); but since I can discover no traces of them in that diligent and excellent naturalist Marcgrave, who resided long in that country, I must deny my assent. But the former is confirmed by that able and honest navigator Dampier, who saw them frequently, as well wild as tame, in the province of Yucatan (Voyages, Vol II, part II, pp. 65, 85, 114), now reckoned part of the Kingdom of Mexico." "In North America they were observed by the very first discoverers. When Rene de Landonniere, patronized by Admiral Coligni, attempted to form a settlement near where Charlestown now stands, he met with them on his first landing in 1564, and by his historian has represented them with great fidelity in the fifth plate of the recital of his voyage (Debry): from his time the witnesses to their being natives of the continent are innumerable. They have been seen in flocks of hundreds in all parts from Louisiana even to Canada; but at this time are extremely rare in a wild state, except in the more distant parts, where they are still found in vast abundance." "It was from Mexico or Yucatan that they were first introduced into Europe; for it is certain that they were imported into England as early as the year 1524, the 15th of Henry VIII. (Baker's Chr. Anderson's Dict., Com. 1, 354. Hackluyt, II, 165, makes their introduction about the year 1532. Barnaby Googe, one of our early writers on Husbandry, says they were not seen here before 1530. He highly commends a Lady Hales of Kent for her excellent management of these fowl, p. 166.) "We probably received them from Spain, with which we had great intercourse till about that time. They were most successfully cultivated in our Kingdom from that period; insomuch that they grew common in every farm-yard, and became even a dish in our rural feasts by the year 1585; for we may certainly depend on the word of old Tusser in his Account of the Christmas Husbandrie Fare." (Five Hundred Points of good Husbandrie, p. 57.) "Beefe, Mutton, and Porke, shredpiece of the best, Pig, Veale, Goose, and Capon, and Turkie well drest, Cheese, Apples and Nuts, jolie carols to heare, As then in the countrie, is counted good cheare." "But at this very time they were so rare in France, that we are told, that the very first which was eaten in that Kingdom appeared at the nuptial feast of Charles IX. in 1570 (Anderson's Dict. Com. 1, 410)."[17] [Illustration: PLATE III Fig. II. Left lateral view of the skull of an old male wild turkey (_Meleagris gallopavo_). See Plate II, Fig. 6, No. 9695, Coll. U. S. National Museum. Photo natural size by Dr. Shufeldt. _pmx_, premaxillary; _n_, nasal bone; _l_, lacrymal bone; _eth_, ethmoid; _p_, parietal; _so_, supraoccipital; _pl_, palatine; _ju_, jugal; _ty_, tympanic; _q_, quadrate; _a_, angular of lower jaw; _d_, dentary. There are many more bones in the skull than those indicated, while the latter serve to invite attention to the principal ones as landmarks.] A little later on Bartram in his travels in the South published some notes on the wild turkey [now _M. g. osceola_] as he found them in Florida during the latter part of the eighteenth century. The original edition of his book, which I have not seen, appeared in 1791. I have, however, examined the edition of 1793, wherein on page 14 he says: "Our turkey of America is a very different species from the Meleagris of Asia and Europe; they are nearly thrice their size and weight. I have seen several that have weighed between twenty and thirty pounds, and some have been killed that have weighed near forty." And further on in the same work he adds [Florida, p. 81]: "Having rested very well during the night, I was awakened in the morning early by the cheering converse of the wild turkey-cocks (Meleagris occidentalis) saluting each other from the sun-brightened tops of the lofty Cupressus disticha and Magnolia grandiflora. They begin at early dawn and continue till sunrise, from March to the last of April. The high forests ring with the noise, like the crowing of the domestic cock, of these social sentinels; the watchword being caught and repeated, from one to another, for hundreds of miles around, insomuch that the whole country is for an hour or more in a universal shout. A little after sunrise, their crowing gradually ceases, they quit then their high lodging places, and alight on the earth, where, expanding their silver-bordered train, they strut and dance round about the coy female, while the deep forests seem to tremble with their shrill noise."[18] Another of the early writers (1806), who paid some attention to the history and distribution of the wild turkeys was Barton. I find the following having reference to some of his observations, viz.: "A memoir has been read before the American Philosophical Society in which the author has shown that at least two distinct species of Meleagris, or turkey, are known within the limits of North America. These are the _Meleagris gallopavo_, or Common Domesticated Turkey, which was wholly unknown in the countries of the Old World before the discovery of America; and the Common Wild Turkey of the United States, to which the author of the memoir has given the name _Meleagris Palawa_--one of its Indian names. "The same author has rendered it very probable that this latter species was _domesticated_ by _some_ of the Indian tribes living within the _present_ limits of the United States, before these tribes had been visited by the Europeans. It is certain, however, that the turkey was not domesticated by the _generality_ of the tribes, within the limits just mentioned, until _after_ the Europeans had taken possession of the countries of North America."[19] Nine or ten years after Barton wrote, De Witt Clinton, who was a candidate for President of the United States in 1812, and a son of James Clinton, was one of the writers of that time on the wild turkey. He pointed out how birds, the turkey included, change their plumage after domestication, and, after giving what he knew of the introduction of the turkey into Spain from America and the West Indies, he adds: "From the Spanish turkey, which was thus spread over Europe, we have obtained our domestic one. The wild turkey has been frequently tamed, and his offspring is of a large size." (p. 126.)[20] Nearly a quarter of a century after Clinton's article appeared, the _anatomy_ of the wild turkey began to attract some attention. Among the first articles to appear on this part of the subject was one by the late Sir Richard Owen, who, apparently taking the similarity of the vernacular names into account, made anatomical comparisons of the organs of smell in the turkey and the turkey buzzard. Naturally, he found them very different,--quite as different, perhaps, as are the olfactory organs of an owl and an ostrich, which I, for one, would not undertake to make a comparison of for publication, simply for the fact that in both these birds their vernacular name begins with the letter o.[21] Even twenty years after this paper appeared there were those who still entertained doubts as to the origin of the domesticated turkeys, and believed that they had nothing to do with the wild forms. Among the doubters, no one was more prominent than Le Conte, who published the following as his opinion at the time, stating: "The conviction that these two birds were really distinct species has long existed in my mind. More than fifty years ago, when I first saw a Wild Turkey, I was led to conclude that one never could have been produced from the other." [Bases it on differences of external characters] (p. 179), adding toward the close of his article: "I defy anyone to show a Turkey, even of the first generation, produced from a pair hatched from the eggs of a wild hen," etc. "I repeat, contrary to the assertions of many others, that no one has ever succeeded in domesticating our Wild Turkey," etc. "Thoroughly believe that the tame and wild bird are different species, and the latter not the ancestor of the tame one." (p. 181.)[22] During the year 1856, the papers Gould published on the wild turkeys attracted considerable attention, and they have been widely quoted since. In one of his first papers on the subject he quotes from Martin the same paragraph which Baird quoted in his article in the Report of the Commissioner of Agriculture (1866 _antea_), while Baird in his article misquotes Gould by saying that the turkey was introduced into England in 1541; whereas Gould states the introduction took place in 1524.[23] Before passing to the more recent literature on these birds, and what I will have to say further on about their comparative osteology and their eggs, it will be as well to reproduce here a few more statements made by Bennett, whose work, "The Gardens and Menagerie of the Zoölogical Society Delineated," I have already quoted.[24] Bennett was also of the opinion that "Daines Barrington was the last writer of any note who denied the American origin of the turkey, and he seems to have been actuated more by a love of paradox than by any conviction of the truth of his theory. Since the publication of his Miscellanies, in 1781, the knowledge that has been obtained of the existence of large flocks of turkeys, perfectly wild, clothed in their natural plumage, and displaying their native habits, spread over a large portion of North America, together with the certainty of their non-existence in a similar state in any other part of the globe, have been admitted on all hands to be decisive of the question." (p. 210). I have already cited the evidence above to prove that it was Oviedo who first published an accurate description of the wild turkey,--his work being published at Toledo in about the year 1526, at which time the turkey had already become domesticated. In other words, it was the Spaniards who first reduced the bird to a state of domestication, and very soon thereafter it was introduced into England. Spain and England were the great maritime nations of those times, and this fact will amply account for the early introduction of the bird into the latter country. Singularly enough, however, we have no account of any kind whatever through which we can trace the exact time when this took place. As others have suggested, it is just possible that it may have been Cabot, the explorer of the then recently discovered coasts of America, who first transported wild turkeys into England. Baker quotes the popular rhyme in his Chronicle: "Turkeys, carps, hoppes, picarel and beer, Came into England all in one year," that is, about 1524, or the 15th of the reign of Henry VIII.[25] What was said by the German author Heresbach was translated by a writer on agricultural subjects, Barnaby Googe, who published it in his work. This appeared in the year 1614, and he refers to "those outlandish birds called Ginny-Cocks and Turkey-Cocks," stating that "before the yeare of our Lord 1530 they were not seene with us!" Further, Bennett points out that "A more positive authority is Hakluyt, who in certain instructions given by him to a friend at Constantinople, bearing date of 1582, mentions, among other valuable things introduced into England from foreign parts, 'Turkey-Cocks and hennes' as having been brought in 'about fifty years past.' We may therefore fairly conclude that they became known in this country about the year 1530."[26] Guinea-fowls were extremely rare in England throughout the sixteenth century, while tame turkeys became very abundant there, forming by no means an expensive dish at festivals,--the first were obtained from the Levant, while the latter were to be found in poultry yards nearly everywhere. In one of the Constitutions of Archbishop Cranmer it was ordered that of fowls as large as swans, cranes, and turkey-cocks, "there should be but one in a dish."[27] When in 1555 the serjeants-at-law were created, they provided for their inauguration dinner two turkeys and four turkey chicks at a cost each of only four shillings, swans and cranes being ten, and half a crown each for capons. At this rate, turkeys could not have been so very scarce in those parts.[28] "Indeed they had become so plentiful in 1573," continues Bennett, "that honest Tusser, in his 'Five Hundred Points of Good Husbandrie,'" enumerates them among the usual Christmas fare at a farmer's table, and speaks of them as "ill neighbors" both to "peason" and to hops. (pp. 212, 213.) "A Frenchman named Pierre Gilles has the credit of having first described the turkey in this quarter of the globe, in his additions to a Latin translation of Ælian, published by him in 1535. His description is so true to nature as to have been almost wholly relied on by every subsequent writer down to Willoughby. He speaks of it as a bird that he has seen; and he had not then been further from his native country than Venice; and states it to have been brought from the New World. "That turkeys were known in France at this period is further proved by a passage in Champier's 'Treatise de Re Cibaria,' published in 1560, and said to have been written thirty years before. This author also speaks of them as having been brought but a few years back from the newly discovered Indian islands. From this time forward their origin seems to have been entirely forgotten, and for the next two centuries we meet with little else in the writings of ornithologists concerning them than an accumulation of citations from the ancients, which bear no manner of relation to them. In the year 1566 a present of twelve turkeys was thought not unworthy of being offered by the municipality of Amiens to their king, at whose marriage, in 1570, Anderson states in his History of Commerce, but we know not on what authority, they were first eaten in France. Heresbach, as we have seen, asserts that they were introduced into Germany about 1530; and that a sumptuary law made at Venice in 1557, quoted by Zanoni, particularizes the tables at which they were permitted to be served. "So ungrateful are mankind for the most important benefits that not even a traditionary vestige remains of the men by whom, or the country from whence, this most useful bird was introduced into any European states. Little therefore is gained from its early history beyond the mere proof of the rapidity with which the process of domestication may sometimes be effected." (pp. 213, 214.) Some ten or more years ago, at a time when I was the natural history editor of _Shooting and Fishing_, in New York City, I published a number of criticisms and original articles upon turkeys, both the wild and domesticated forms.[29] About twelve years ago, Mr. Nelson contributed a very valuable article on wild turkeys, portions of which are eminently worthy of the space here required to quote them.[30] He says among other things in this article that "All recent ornithologists have considered the wild turkey of Mexico and the southwestern United States (aside from _M. gallopavo intermedia_) as the ancestor of the domesticated bird. This idea is certainly erroneous, as is shown by the series of specimens now in the collection of the Biological Survey. When the Spaniards first entered Mexico they landed near the present city of Vera Cruz and made their way thence to the City of Mexico. [Illustration: PLATE IV Fig. 12. Superior view of the cranium of a large male tame turkey, with right nasal bone (_n_) attached _in situ_. Specimen in Dr. Shufeldt's private collection. Fig. 13. Left lateral view of the skull of a female turkey, probably a wild one. No. 19684, Coll. U. S. National Museum. (See Fig. 8, Pl. II.) _e_, bony entrance to ear. Compare contour line of cranium with Fig. 14. Fig. 14. Left lateral view of the cranium of a tame turkey; male. Dr. Shufeldt's private collection. Fig. 15. Direct posterior view of the cranium of a tame turkey, probably a female. _pf_, postfrontal. Specimen in Dr. Shufeldt's collection. Fig. 16. Skull of a wild Florida turkey, seen from below (_M. g. osceola_). (See Fig. 10, Pl. II.) Bones named in Fig. 18. Photo natural size by Dr. Shufeldt and considerably reduced.] "At this time they found domesticated turkeys among the Indians of that region, and within a few years the birds were introduced into Spain.[31] "The part of the country occupied by the Spanish during the first few years of the conquest in which wild turkeys occur is the eastern slope of the Cordillera in Vera Cruz, and there is every reason to suppose that this must have been the original home of the birds domesticated by the natives of that region. "Gould's description of the type of _M. mexicana_ is not sufficiently detailed to determine the exact character of this bird, but fortunately the type was figured in Elliot's "Birds of North America."... In addition Gould's type apparently served for the description of the adult male _M. gallopavo_ in the 'Catalogue of Birds Brit. Mus.' (xxii, p. 387), and an adult female is described in the same volume from Ciudad Ranch Durango.... Thus it will become necessary to treat _M. gallopavo_ and _M. mexicana_ as at least subspecifically distinct. Whatever may be the relationship of _M. mexicana_ to _M. gallopavo_, the _M. g. merriami_ is easily separable from _M. g. mexicana_ of the Sierra Madre of western Mexico, from Chihuahua to Colima. Birds from northern Chihuahua are intermediate." In this article Mr. Nelson names _M. g. merriami_ and gives full descriptions of the adult male and female in winter plumage. What has thus far been presented above on the first discovery of the American wild turkeys, their natural history in the New World, their introduction into Spain, England, France, and elsewhere, is practically all we have on this part of our subject up to date. What I have given is from the very best ornithological and other authorities. Domesticated turkeys are now found in nearly all parts of the world, while in only a very few instances has any record been kept of the different times of their introduction. With the view of accumulating such data, one would have to search the histories of all the countries of all the civilized and semi-civilized peoples of the world, which would be the labor of almost a man's entire lifetime, and in only too many instances his search would be in vain, for the several records of the times of introducing these birds were not made. Apart from the description of the wild turkeys, there is still a very large literature devoted to the domesticated forms of turkeys as they occur in this country and abroad, as well as descriptions of their eggs. I have gone over a large part of this literature, but shall be able to use only a small, though nevertheless essential, part of it here. This I shall complete with an account of _turkey eggs_, which will be presented quite apart from anything to do with their nests, nesting habits, and much else which will be fully treated in other chapters of this book. In some works we meet with the literature of all these subjects together, others have only a part, while still others are confined to one thing, as the eggs.[32] Darwin in his works paid considerable attention to the wild and tame turkeys. He states that "Professor Baird believes (as quoted in Tegetmeier's 'Poultry Book,' 1866, p. 269) that our turkeys are descended from a West Indian species, now extinct. But besides the improbability of a bird having long ago become extinct in these large and luxuriant islands, it appears, as we shall presently see, that the turkey degenerates in India, and this fact indicates that this was not aboriginally an inhabitant of the lowlands of the tropics. "F. Michaux," he further points out, "suspected in 1802 that the common domestic turkey was not descended from the United States species alone, but was likewise from a southern form, and he went so far as to believe that English and French turkeys differed from having different proportions of the blood of the two parent-forms.[33] "English turkeys are smaller than either wild form. They have not varied in any great degree; but there are some breeds which can be distinguished--as Norfolks, Suffolks, Whites, and Copper-Coloured (or Cambridge), all of which, if precluded from crossing with other breeds, propagate their kind truly. Of these kinds, the most distinct is the small, hardy, dull-black Norfolk turkey, of which the chickens are black, with occasionally white patches about the head. The other breeds scarcely differ except in colour, and their chickens are generally mottled all over with brownish-grey.[34] "In Holland there was formerly, according to Temminick, a beautiful buff-yellow breed, furnished with an ample white topknot. Mr. Wilmot has described a white turkey-cock with a crest formed of 'feathers about four inches long, with bare quills, and a tuft of soft down growing at the end.'[35] Many of the young birds whilst young inherited this kind of crest, but afterwards it either fell off or was pecked out by the other birds. This is an interesting case, as with care a new breed might probably have been formed; and a topknot of this nature would have been, to a certain extent, analogous to that borne by the males in several allied genera, such as _Euplocomus_, _Lophophorus_, and _Pavo_."[36] Darwin has further pointed out that "The tuft of hair on the breast of the wild turkey-cock cannot be of any use, and it is doubtful whether it can be ornamental in the eyes of the female birds; indeed, had the tuft appeared under domestication, it would have been called a monstrosity. "The naked skin on the head of a vulture is generally considered as a direct adaptation for wallowing in putridity; and so it may be, or it may possibly be due to the direct action of putrid matter; but we should be very cautious in drawing any such inference, when we see that the skin on the head of the clean-feeding male turkey is likewise naked."[37] [Illustration: PLATE V Fig. 17. Left lateral view of the skull, including lower jaw, of a wild turkey; probably a female. No. 19684, Coll. U. S. National Museum. (See Fig. 8, Pl. II, and Fig. 13.) _ena_, external narial aperture. Fig. 18. Skull of wild Florida turkey. (See Fig. 16.) _pmx_, premaxillary; _l_, lacrymal; _pt_, pterygoids; _q_, quadrate; _c_, occipital condyle; _mxp_, maxillo-palatine; _pl_, palatines. Fig. 19. Skeleton of the left foot of a wild turkey (female?) No. 19684, Coll. U. S. National Museum. Several views of the skull of this individual are given above. The shortest toe is the hind toe or hallux, and has a claw and a joint; then there are 3, 4, and 5 phalangeal joints to the second, third, and fourth toes respectively--that is in the inner, middle, and outer one. This count includes the distal or claw joints (ungual joints). All three figures photo natural size by Dr. Shufeldt and considerably reduced in reproduction.] Newton has pointed out that the topknotted turkeys were figured by Albin in 1738, and that it "has been suggested with some appearance of probability that the Norfolk breed may be descended from the northern form, _Meleagris gallopavo_ or _americana_, while the Cambridgeshire breed may spring from the southern form the _M. mexicana_ of Gould (P. Z. S. 1856, p. 61), which indeed it very much resembles, especially in having its tail-coverts and quills tipped with white or light ochreous--points that recent North American ornithologists rely upon as distinctive of this form. If this supposition be true, there would be reason to believe in the double introduction of the bird into England at least, as already hinted, but positive information is almost wholly wanting." (_Ibid._, p. 996.). It is an interesting fact that the males of both the wild and tame forms of turkeys frequently lack spurs;[38] and Henshaw has pointed out that in the case of _M. g. merriami_ "A few of the gobblers had spurs; in one instance these took the form of a blunt, rounded knob half an inch long. In others, however, it was much reduced, and in others still the spur was wanting; though my impression is that all the old males had this weapon."[39] One of the best articles which have been contributed to the present part of our subject, appeared several years ago from the pen of that very excellent naturalist, the late Judge Caton of Chicago. This contribution is rather a long one, and I shall only select such paragraphs from it as are of special value in the present connection.[40] It is a well-known fact that the author of this work made a long series of observations on wild turkeys which he kept in confinement. He raised many from the eggs of the wild turkey taken in nature and hatched out by the common hen on his own preserves. At one time he had as many as sixty such birds, and he lost no opportunity to study their habits. They were of the pure stock with all their characters as in the wild form. These turkeys became very tame when thus raised from the eggs of the wild birds, and they did not deteriorate, either in size or in their power of reproduction. "This magnificent game bird," says Caton, "was never a native of the Pacific Coast. I have at various times sent in all about forty to California, in the hope that it may be acclimatized in the forests. Their numerous enemies have thus far prevented success in this direction, but they have done reasonably well in domestication, and Captain Rodgers of the United States Coast Survey has met with remarkable success in hybridizing them with the domestic bronze turkey. Last spring I sent some which were placed on Santa Clara Island, off Santa Barbara. They remained contentedly about the ranch building and, as I am informed, raised three broods of young which are doing well. As there is nothing on the island more dangerous to them than a very small species of fox, we may well hope that they will in a few years stock the whole island, which is many miles in extent. As the island is uninhabited except by the shepherds who tend the immense flocks of sheep there, they will soon revert to the wild state, when I have no doubt they will resume markings as constant as is observed in the wild bird here, but I shall be disappointed if the changed condition of life does not produce a change of color or in the shades of color, which would induce one unacquainted with their history to pronounce them specifically different from their wild ancestors here. Results will be watched with interest. "My experiments in crossing the wild with the tame have been eminently successful." (Followed by a long account, p. 329.) "My experiments establish first that the turkey may be domesticated, and that each succeeding generation bred in domestication loses something of the wild disposition of its ancestors. "Second, that the wild turkey bred in domestication changes its form and the color of its plumage and of its legs, each succeeding generation degenerating more and more from these brilliant colors which are so constant on the wild turkey of the forest, so that it is simply a question of time--and indeed a very short time--when they will lose all of their native wildness and become clothed in all the varied colors of the common domestic turkey; in fact be like our domestic turkey,--yes, be our domestic turkey. "Third, that the wild turkey and the domestic turkey as freely interbred as either does with its own variety, showing not the least sexual aversion always observed between animals of different species of the same genus, and that the hybrid progeny is as vigorous, as robust, and fertile as was either parent. "It must be already apparent that I, at least, have no doubt that our common domestic turkey is a direct descendant of the wild turkey of our forests, and that therefore there is no specific difference between them. If such marked changes in the wild turkey occur by only ten years of domestication, all directly tending to the form, habits, and colorings of the domestic turkey,--in all things which distinguish the domestic from the wild turkey,--what might we not expect from fifty or a hundred years of domestication? I know that the best ornithological authority at the present time declares them to be of a different species, but I submit that this is a question which should be reconsidered in the light of indisputable facts which were not admitted or established at the time such decision was made. "There has always been diffused among the domestic turkeys of the frontiers more or less of the blood of the wild turkey of the neighboring forests, and as the wild turkey has been driven back by the settlement of the country, the domestic turkey has gradually lost the markings which told of the presence of the wild; though judicious breeding has preserved and rendered more or less constant some of this evidence in what is called the domestic bronze turkey, as the red leg and the tawny shade dashed upon the white terminals of the tail feathers and the tail-coverts, the better should the stock be considered, because it is the more like its wild ancestor. "That the domestic turkey in its neighborhood may be descended from or largely interbred with the wild turkey of New Mexico, which in its wild state more resembles the common domestic turkey than our wild turkey does, may unquestionably be true, and it may be also that the wild turkey there has a large infusion of the tame blood, for it is known that not only our domestic turkey, but even our barnyard fowls, relapse to the wild state in a single generation when they are reared in the woods and entirely away from the influence of man, gradually assuming uniform and constant colorings. But I will not discuss the question whether the Mexican wild turkey is of a different species from ours or merely a variety of the same species, only with differences in color which have arisen from accidental causes, and certainly I will not question that the Mexican turkey is the parent of many domestic turkeys, but I cannot resist the conclusion that our wild turkey is the progenitor of our domestic turkey." We have now come to where we can study the eggs of these birds, and in the same article I have just quoted so extensively from, Judge Caton says on page 324 of it, "The eggs of the wild turkey vary much in coloring and somewhat in form, but in general are so like those of the tame turkey that no one can select one from the other. The ground color is white, over which are scattered reddish-brown specks. These differ in shades of color, but much more in numbers. I have seen some on which scarcely any specks could be detected, while others were profusely covered with specks, all laid by the same hen in the same nest. The turkey eggs are more pointed than those of the goose or the barnyard fowl, and are much smaller in proportion to the size of the bird." This, in the main, is a fair description of the eggs of _Meleagris_, while at the same time it may be said that the ground color is not always "white," nor the markings exactly what might be denominated "specks." Turkey eggs of all kinds, laid by hens of the wild as well as by those of the domesticated birds, have been described and figured in a great many popular and technically scientific books and other works, in this country as well as abroad. A large part of this literature I have examined, but I soon became convinced of the fact that _no general description_ would begin to stand for the different kinds of eggs that turkeys lay. They not only differ in size, form, and markings, but in ground colors, numbers to the clutch, and some other particulars. Then it is true that no wild turkey hen, of any of the known subspecies or species of this country, has ever laid an egg but what some hen of the domestic breeds somewhere has not laid one practically exactly like it in all particulars. In other words, the eggs of our various breeds of tame turkeys are like the eggs of the several forms of the wild bird, that is, the subspecies known to science in the United States avifauna. Therefore I have not thought it necessary to present here any descriptions of the eggs of the tame turkeys or reproductions of photographs of the same. Among the most beautiful of the wild turkey eggs published are those which appear in Major Bendire's work. They were drawn and painted by Mr. John L. Ridgway of the United States Geological Survey.[41] These very eggs I have not only examined, studied and compared, but, thanks to Dr. Richmond of the Division of Birds of the Museum, and to Mr. J. H. Riley, his assistant, I had such specimens as I needed loaned me from the general collection of the Museum, in that I might photograph them for use in the present connection. Dr. Richmond did me a special kindness in selecting for my study the four eggs here reproduced from my photograph of them in Plate VI. These are all of _M. g. silvestris_. Of these, figures 20 and 21 are from the same clutch, and doubtless laid by the same bird. (Nos. 30014, 30014.) They were collected by J. H. Riley at Falls Church, Va. Figure 20 is an egg measuring 66 mm. x 45 mm., the color being a pale buffy-brown, finely and nearly evenly speckled all over with umber-brown, with very minute specks to dots measuring a millimetre in diameter. The finest speckling, with no larger spots, is at the greater end (butt) for a third of the egg. [Illustration: PLATE VI Eggs of wild turkey (_M. g. silvestris_) Names and descriptions given in the text. All the specimens photo natural size by Dr. Shufeldt and somewhat reduced in reproduction. Fig. 20. Upper left-hand one. Fig. 21. Upper right-hand one. Fig. 22. Lower left-hand one. Fig. 23. Lower right-hand one.] Figure 21 measures 63 mm. x 45 mm., the ground color being a pale cream, speckled somewhat thickly and uniformly all over with fine specks of light brown and lavender, with larger spots and ocellated marks of lavender moderately abundant over the middle and the apical thirds, with none about the larger end or remaining third. Figure 22 (Plate VI) is No. 31185 of the collection of the U. S. National Museum (ex Ralph Coll.); it was collected at Bridgeport, Michigan, by Allan Herbert (376, 4700, '77) and measures 68 x 46. It is of a rather deep buffy-brown or ochre, very thickly and quite uniformly speckled all over with more or less minute specks of dark brown. Figure 23 was collected by H. R. Caldwell (91310), the locality being unrecorded (Coll. U. S. Nat. Museum, No. 32407), and measures 63 x 48. It is of a pale buffy-brown or pale _café au lait_ color, quite thickly speckled all over with fine dots and specks of light brown. Some few of the specks are of noticeably larger size, and these are confined to the middle and apical thirds. Speckling of the butt or big end extremely fine, and the specks of lighter color. Referring to the wild turkey (_M. g. silvestris_) Bendire says (_loc. cit._, p. 116): "In shape, the eggs of the Wild Turkey are usually ovate, occasionally they are elongate ovate. The ground color varies from pale creamy white to creamy buff. They are more or less heavily marked with well-defined spots and dots of pale chocolate and reddish brown. In an occasional set these spots are pale lavender. Generally the markings are all small, ranging in size from a No. 6 shot to that of dust shot, but an exceptional set is sometimes heavily covered with both spots and blotches of the size of buckshot, and even larger. The majority of eggs of this species in the U. S. National Museum collection, and such as I have examined elsewhere, resemble in coloration the figured type of _M. gallopavo mexicanus_, but average, as a rule, somewhat smaller in size. "The average measurement of thirty-eight eggs in the U. S. National Museum collection is 61.5 by 46.5 millimetres. The largest egg measures 68.5 by 46, the smallest 59 by 45 millimetres." At the close of his account of _M. g. mexicanus_ Bendire states that "The only eggs of this species in the U. S. National Museum collection, about whose identity there can be no possible doubt, were collected on Upper Lynx Creek, Arizona, in the spring of 1870, by Dr. E. Palmer, whose name is well known as one of the pioneer naturalists of that Territory. "The eggs are ovate in shape, their ground color is creamy white, and they are profusely dotted with fine spots of reddish brown, pretty evenly distributed over the entire egg. The average measurements of these eggs is 69 by 49 millimetres. The largest measures 70.5 by 49, the smallest 67 by 48 millimetres. "The type specimen (No. 15573, U. S. National Museum collection, Pl. 3, Fig. 15) is one of the set referred to above" (_loc. cit._ p. 119). This set of three eggs I have personally studied; they are of _M. g. merriami_, and I find them to agree exactly with Captain Bendire's description just quoted.[42] In the Ralph Collection (U. S. Nat. Mus. No. 27232; orig. No. 10/6) I examined six (6) eggs of _M. g. intermedia_. They are of a pale ground color, all being uniformly speckled over with minute dots of lightish brown. These eggs are rather large for turkey eggs. They were collected at Brownsville, Texas, May 26, 1894. Another set of _M. g. intermedia_ collected by F. B. Armstrong (No. 25765, coll. U. S. Nat. Mus.) are practically _unspotted_, and such spots as are to be found are very faint, both the minute and the somewhat large ones. In Dr. Ralph's collection (U. S. Nat. Mus. No. 27080) eggs of _M. g. intermedia_ are _short_, with the large and fine dots of a pale _orange yellow_. I examined a number of eggs and sets of eggs of _M. g. osceola_, or Florida turkey. In No. 25787 the eggs are short and broad, the ground color being pale whitish, slightly tinged with brown. Some of the spots on these eggs are unusually large, in a few places, three or four running together, or are more or less confluent; others are isolated and of medium size; many are minute, all being of an earth brown, varying in shades. In the case of No. 25787 of this set, the dark-brown spots are more or less of a size and fewer in number; while one of them (No. 25787) is exactly like the egg of Plate VI, Fig. 22; finally, there is a pale one (No. 25787) with _fine_ spots, few in number in middle third, very numerous at the ends. There are _scattered large spots_ of a dark brown, the surface of each of which latter are raised with a kind of incrustation. Another egg (No. 27869) in the same tray (_M. g. osceola_) is _small_, pointed; pale ground color with very fine spots of light brown (coll. W. L. Ralph). Still another in this set (No. 27868) is markedly _roundish_, with minute brown speckling uniformly distributed. There are nine (9) eggs in this clutch (No. 27868), and apart from the differences in form, they all closely resemble each other; and this is by no means always the case, as the same hen may lay any of the various styles enumerated above, either as belonging to the same clutch, or at different seasons. As it is not the plan of the author of the present work to touch, in this chapter, upon the general habits of wild turkeys--their courtship, their incubation, the young at various stages, nesting sites, and a great deal more having to do with the natural history of the family and the forms contained in it--it would seem that what has been set forth above in regard to the eggs of the several subspecies in our avifauna pretty thoroughly covers this part of the subject. Shortly after the last paragraph was completed I received a valuable photograph of the nest and eggs of _M. g. merriami_, and this I desire to publish here with a few notes, although in so doing it constitutes a departure from what I have just stated above in regard to the nests of turkeys. This photograph was kindly furnished me by my friend Mr. F. Stephens of the Society of Natural History of San Diego, California, with permission to use it in the present connection. It has not to my knowledge been published before, though the existence of the negative from which it was printed has been made known to ornithologists by Major Bendire, who says, in his account of the "Mexican Turkey" in his _Life Histories of North American Birds_ (_loc. cit._ p. 118): "That well-known ornithologist and collector, Mr. F. Stephens, took a probably incomplete set of nine fresh eggs of this species, on June 15th, 1884. He writes me: 'I was encamped about five miles south of Craterville, on the east side of the Santa Rita Mountains in Arizona; the nest was shown to my assistant by a charcoal burner. On his approach to it the bird ran off or flew before he got within good range. He did not disturb it but came to camp, and in the afternoon we both went, and I took my little camera along and photographed it. The bird did not show up again. The locality was on the east slope of the Santa Rita Mountains, in the oak timber, just where the first scattering pines commenced, at an altitude of perhaps 5000 feet.' "A good photograph, kindly sent me by Mr. Stephens, shows the nest and eggs plainly. It was placed close to the trunk of an oak tree on a hillside, near which a good-size yucca grew, covering, apparently, a part of the nest; the hollow in which the eggs were placed was about 12 inches across and 3 inches deep. Judging from the photograph the nest was fairly well lined." In order to complete my share of the work, I will now add here a few paragraphs and illustrations upon the skeletal differences to be found upon comparison of that part of the anatomy of wild and domesticated turkeys. This is a subject I wrote upon many years ago; what I then said I have just read over, and I find I can do no better than quote the part contained in the "Analytical Summary" of the work. It is more or less technical and therefore must be brief, though it is none the less necessary to complete the subject of the present treatise.[43] 1. As a rule, in adult specimens of _M. g. merriami_, the posterior margins of the nasal bones indistinguishably fuse with the frontals; whereas, as a rule, in domesticated turkeys these sutural traces persist with great distinctness throughout life. 2. As a rule, in wild turkeys we find the craniofrontal region more concaved and wider across than it is in the tame varieties. 3. The parietal prominences are apt to be more evident in _M. g. merriami_ than they are in the vast majority of domesticated turkeys; and the median longitudinal line measured from these to the nearest point of the occipital ridge is longer in the tame varieties than it is in the wild birds. Generally speaking, this latter character is very striking and rarely departed from. 4. The figure formed by the line which bounds the occipital area is, as a rule, roughly semicircular in a domesticated turkey, whereas in _M. g. merriami_ it is nearly always of a cordate outline, with the apex upward. In the case of the tame turkeys I have found it to average one exception to this in every twelve birds; in the exception, the bounding line of the area made a cordate figure as in wild turkeys. 5. Among the domesticated turkeys, the interorbital septum almost invariably is pierced by a large irregular vacuity; as a rule this osseous plate is entire in wild ones. 6. The descending process of a lacrymal bone is more apt to be longer in a wild turkey than in a tame one; and for the average the greater length is always in favor of the former species. 7. In _M. g. merriami_ the arch of the superior margin of the orbit is more decided than it is in the tame turkey, where the arc formed by this line is shallowed, and not so elevated. 8. We find, as a rule, that the pterygoid bones are rather longer and more slender in wild turkeys than they are among the tame ones. 9. At the occipital region of the skull, the osseous structures are denser and thicker in the tame varieties of turkeys; and, as a whole, the skull is smoother, with its salient apophyses less pronounced in them than in the wild types. There is a certain delicacy and lightness, very difficult to describe, that stamps the skull of a wild turkey, and at once distinguishes it from any typical skull of a tame one. 10. I have predicted that the average size of the brain cavity will be found to be smaller and of less capacity in a tame turkey than it is in the wild one. In the case of this class of domesticated birds, as pointed out above, this would seem to be no more than natural, for the domestication of the turkey has not been of such a nature as to develop its brain mass through the influences of a species of education; its long contact with man has taught it nothing--quite the contrary, for the bird has been almost entirely relieved from the responsibilities of using its wits to obtain its food, or to guard against danger to itself. These factors are still in operation in the case of the wild types, and the advance of civilization has tended to sharpen them. From this point of view, then, I would say that mentally the average wild turkey is stronger than the average domesticated one, and I believe it will be found that in all these long years the above influences have affected the size of the brain-mass of the latter species in the way above indicated, and perhaps it may be possible some day to appreciate this difference. Perhaps, too, there may have been also a slight tendency on the part of the brain of the wild turkey to increase in size, owing to the demands made upon its functions due to the influence of man's nearer approach, and the necessity of greater mental activity in consequence. Recently I examined a mounted skeleton of a female wild turkey in the collection of the United States National Museum, and apart from the skull it presented the following characters: There were fifteen vertebræ, the last one having a pair of free ribs, before we arrived at the fused vertebræ of the dorsum. Of these latter there were three coössified into one piece. The sixteenth vertebra supports a pair of free ribs that fail to meet the sternum, there being no costal ribs for them. They bear uncinate processes. Next we find four pairs of ribs that articulate with hæmapophyses, and through them with the sternum. There are two free vertebræ between the consolidated dorsal ones and the pelvis; and the pelvis bears a pair of free ribs, the costal ribs of which articulate by their anterior ends with the posterior border of the pair of costal ribs in front of them. A kind of long abutment exists at the middle point on each, there to accommodate the articulation. There are six free tail vertebræ plus a long pointed pygostyle. The os furcula is rather slender, being of a typical V-shaped pattern, with a small and straight hypocleidium. With a form much as we find it in the fowl, the pelvis is characterized by _not_ having the ilia meet the sacral crista in front. The prepubis is short and stumpy. The external pair of xiphoidal processes of the sternum are peculiar in that their posterior ends are strongly bifurcated. [Illustration: PLATE VII Fig. 24. Nest of a wild turkey _in situ_. (_M. g. merriami._) Photo by Mr. F. Stephens, San Diego, California.] In the skeleton of the manus, the pollex metacarpal projects forward and upward as a rather conspicuous process. Its phalanx does not bear a claw, and on the index metacarpal the indicial process is present and overlaps the shaft of the next metacarpal behind it. In the leg the fibula is free, and extends halfway down the tibiotarsal shaft. The hypotarsus of the tarso-metatarsus is grooved mesially for the passage of tendons behind, and is also once perforated near its middle for the same purpose. As I have already stated, the remainder of the skeleton of this bird is characteristically gallinaceous and need not detain us longer here. I would add, however, that the "tarsal cartilages" in the turkey extensively ossify. FOOTNOTES: [9] Audubon, J. J. "The Birds of America," Vol. V, pp. 54-55. Even in Audubon's time the wild turkeys were being rapidly exterminated. At this time _M. g. silvestris_ does not occur east of central Pennsylvania. [10] Columella. (_De Re Rustica_, VIII, cap. 2.) Edwards (_Gleanings_, II, p. 269). 1760? [11] Newton, Alfred. _A Dictionary of Birds._ (Assisted by Hans Gadow, with contributions from Richard Lydekker, Chas. S. Roy, and Robert W. Shufeldt, M. D.) Pt. IV, 1896, p. 994. The quotation is from the Art. "Turkey," and in further reference to its name, Professor Newton remarks, "The French _Coq_ and _Poule d'Inde_ (whence _Dindon_) involve no contradiction, looking to the general idea of what India then was. One of the earliest German names for the bird, _Kalekuttisch Hiim_ (whence the Scandinavian _Kalkun_) must have arisen through some mistake at present inexplicable; but this does not refer, as is generally supposed, to Calcutta, but to Calicut on the Malabar coast (Notes and Queries, ser. 6, X, p. 185). "But even Linnæus could not clear himself of the confusion, and, possibly following Sibbald, unhappily misapplied the name _Meleagris_, undeniably belonging to the guinea-fowl, as the generic term for what we now know as the turkey, adding thereto as its specific designation the word _gallopavo_, taken from the _Gallopavus_ of Gesner, who, though not wholly free from error, was less mistaken than some of his contemporaries and even successors." [12] Baird, Spencer F. _The Origin of the Domestic Turkey._ Rep. of the Comm. of Agricul. for the year 1866. Washington Gov. Printing Office, 1867, pp. 288-290. In this article Professor Baird undertakes to demonstrate "that there are two species of wild turkey in North America; one confined to the more eastern and southern United States, the other to the southern Rocky Mountains and adjacent part of Texas, New Mexico, and Arizona; that the latter extends along eastern Mexico as far south at least as Orizaba, and that it is from this Mexican species and not from that of eastern North America that this domestic turkey is derived." [Reprinted in Hist. of N. Amer. Birds, III, p. 411, footnote.] [13] Bennett, E. T. "The Gardens and Menagerie of the Zoölogical Society delineated." [The Drawings by William Harvey; Engr. by Branston and Wright, assisted by other artists] London, 1835. Further on, this article will be quoted on other points, as it treats of the entire history of the wild turkey. [14] In the original work, here quoted, names of persons and some other nouns are printed in capitals--an old custom which publishers of the present work decided not to follow. My MS. was made to agree with the original in all particulars. R. W. S. [15] Pennant, Thos. Esqr. F. R. S. "An Account of the Turkey." Phil. Trans. of the Royal Society of London. Vol. LXXI for the year 1781. London [Art.] No. 1. Communicated by Joseph Banks, Esqr., P. R. S. Read December 21, 1781, pp. 77, 78. Pennant's contribution fills a large place in the literature of the wild turkey, and further on I shall take occasion to quote still more extensively from it. It starts in by giving in brief the characters of the turkey, and in describing the wild turkey he cites the previous works of Josselyn (Voyage); Clayton (Virginia); Catesby, Belon, Gesner, Aldrovandus, Ray, Buffon, and others. He gives a "Description" of the bird, especially the "Tail," and adds that a "White Turkey"--"A most beautiful kind has of late been introduced into England of a snowy whiteness, finely contrasting with its red head. These I think came from Holland, probably bred from an accidental white pair; and from them preserved pure from any dark or variegated birds." (p. 68.) He presents variation in "Size," quoting Josselyn (New-Eng. Rarities); Lawson (History of Carolina); and Clayton (Phil. Trans.). Also their "Manners"; their being "Gregarious"; "Their Haunts," "Place," and much else, having more to do with their habits than their history, and consequently not legitimately to be touched upon in this chapter. [16] Coues, Elliott. "History of the Wild Turkey." _Forest and Stream_, XIII, January 1, 1879, p. 947. Another work I have examined on this part of our subject is D. G. Elliot's "Game Birds of America," and the turkey cuts in this book were copied by Coues into the last edition of his "Key to North American Birds," and very poorly done. Dr. D. G. Elliot's superb work, illustrated by magnificent colored plates by the artist Wolfe, on "A Monograph of the Phasianidæ or the Family of the Pheasants," I have not examined. The copy in the Library of Congress was out on a loan when I made application for it. Several plates of different species of wild turkeys are to be found in it. [17] Pennant's article is illustrated by a folding plate giving the leg of a turkey bearing a supernumery toe situated in front of the tibiotarsus with the claw above. The note in reference to it is here reproduced in order to complete the article. Philos. Trans., Vol. LXXI, Ab. III, p. 80: "To this account I beg leave to lay before you the very extraordinary appearance on the thigh of a turkey bred in my poultry yard, and which was killed a few years ago for the table. The servant in plucking it was very unexpectedly wounded in the hand. On examination the cause appeared so singular that the bird was brought to me. I discovered that from the thigh-bone issued a short upright process, and to that grew a large and strong toe, with a sharp and crooked claw, exactly resembling that of a rapacious bird." [18] Bartram, William. Travels through North and South Carolina, Georgia, East and West Florida, the Cherokee Country, the Extensive Territories of the Muscogalges or Creek Confederacy, and the Country of the Choctaws. Containing an account of the soil and Natural Productions of those regions; together with the observations on the manners of the Indians. Embellished with Copper Plates. The original edition of Bartram is cited in the _Third Instalment of American Ornithological Bibliography_ by Elliott Coues (the references being pp. 83 and 290 _bis_). Bull. U. S. Geol. and Geogr. Surv. Terr. 1879, p. 810, Govm't Printing Office. It is here in this work of his that Bartram designates the domestic turkey as _Meleagris gallopavo_, Linn.; and the wild turkey of this country (_M. occidentalis_) (p. 83) as _M. americanus_ (p. 290 _bis_). [19] Barton, P. S. _The Philadelphia Medical and Physical Journal_, Vol. II, 1806, pp. 162-164. Coues, in his _Ornitho. Biblio._, cited above, omits the words, "The Philadelphia," which gives trouble to find the work in a library; he also has the year wrong, giving 1805 for 1806--the latter being correct. The copy I consulted had no Pl. 1, with the article, that I happened to see. [20] Clinton, De Witt. _Trans. Lit. and Philos. Soc._, New York, 1, 1815, pp. 21-184. Note S. pp. 125-128. [21] Owen, R. P. Z. S., V. 1837, pp. 34, 35. [22] Le Conte, John. _Proc. Acad. Nat. Sci. of Phila._ IX, 1857, pp. 179-181. The distinctive characters and the habits, as given by this author of the wild and domesticated turkeys of the United States, are doubtless of some value; but the deductions he draws from the comparisons made are, as we know, quite erroneous. I have not examined the article by E. Roger in the _Bull. Soc. Acclim._ cited by Coues in his _Ornitho. Biblio._ as having appeared in the "2c Ser. VII, 1870, pp. 264-266." Either the year or the pagination, or both, of the citation is wrong, and as many of the copies were out at the time of my search, and the others distributed through several libraries, I failed to obtain it. R. W. S. [23] Gould, J. 2. On a new turkey, _Meleagris Mexicana_. P. Z. S. XXIV, 1856, pp. 61-63. (In his _Ornithol. Bibliogr._) Coues remarks upon this as follows: "Subsequently determined to be the stock whence the domestic bird descended, and hence a synonym of _M. gallopavo_, Linn." This paper was extensively republished at the time, generally under the title of "A new species of turkey from Mexico" [all citing the P. Z. S. article]. One journal quoted it as follows: "Mr. Gould exhibited a specimen of turkey which he had obtained in Mexico, and which differed materially from the wild turkey of the United States. At the same time this turkey so closely resembled the domesticated turkey of Europe that he believed naturalists were wrong in attributing its origin to the United States species. The present specimen was therefore a new species, and he proposed to call it _Meleagris Mexicana_, which, if his theory was correct, must henceforth be the designation of the common turkey." Amer. Jour. Sci. XXII, 1856, p. 139. Under the same title this latter was reprinted in Edinb. _New Philos. Journ._ n. s., iv, 1856, pp. 371, 372. See also Bryant, H. "_Remarks on the supposed new species of turkey, Meleagris Mexicana, recently described by Mr. Gould._" Proc. Bost. Soc. Nat. Hist. vi, 1857, pp. 158, 159. "In the Proceedings of the Zoölogical Society of London for 1856, page 61," says Professor Baird, "Mr. Gould characterizes as new a wild turkey from the mines of Real del Norte, in Mexico, under the name of _Meleagris Mexicana_, and is the first to suggest that it is derived from the domesticated bird, and not from the common wild turkey of eastern North America, on which he retains the name of _M. gallopavo_, of Linnæus. He stated that the peculiarities of the new species consist chiefly in the creamy white tips of the tail feathers and of the upper tail coverts, with some other points of minor importance. I suggest that the wild turkey of New Mexico, as referred to by various writers, belongs to this new species, and not to the _M. gallopavo_." (loc. cit. p. 289.) Compare the above with what Professor Baird states in the series of the _Pacif. Railroad Reports_, vol. ix, p. 618, with the remainder of the above quoted article, which is too long to reproduce here. [24] Bennett, E. T. "Publ. with the sanction of the council under the superintendence of the Secretary and Vice Secretary of the Society. Birds. Vol. II. London, 1835, pp. 209-224." There is a very excellent wood-cut of a turkey illustrating this article (left lateral view), of which the author says: "Our own figure is taken from a young male, in imperfect plumage, brought from America by Mr. Audubon. Another specimen, in very brilliant plumage, but perhaps not purely wild, forms a part of the Society's Museum" (p. 223). Bennett derived most of his information about the habits of the wild turkey in nature "from an excellent memoir by M. Charles Lucien Bonaparte, in his continuation of Wilson's American Ornithology." "In that work M. Bonaparte claims credit for having given the first representation of the wild turkey;* and justly so, for the figures introduced into a landscape in the account of De Laudonniere's Voyage to Florida in De Bry's Collection, and that published by Bricknell in his Natural History of North Carolina, cannot with certainty be referred to the native bird. They are besides too imperfect to be considered as characteristic representations of the species. Much about the same time with M. Bonaparte's figure appeared another, in M. Viellot's Galerie des Oiseaux, taken from a specimen in the Paris Museum. "It is somewhat singular that so noble a bird, and in America at least by no means a rare one, should have remained unfigured until within five years of the present time; all the plates in European works being manifestly derived from domestic specimens." Bennett was aware that Audubon's Plates were published about this time, for he mentions them. He also was well informed in matters regarding the crossing of the wild male turkey with the female domestic one, and with the improvement in the breed thus obtained. * Note: Newton disputes this and says: "In 1555 both sexes were characteristically figured by Belon (Oiseaux, p. 249), as was the cock by Gesner in the same year, and these are the earliest representations of the bird known to exist." (Dict. of Birds, pp. 995, 996.) [25] Newton states that this assertion "is wholly untrustworthy," as carp, pickerel (and other commodities) both lived in this country (England) long before 1524, "if indeed they were not indigenous to it." (Dict. of Birds, p. 995). [26] No two authors seem to agree upon the exact date when the turkey was really introduced into England. Here Bennett states positively 1530; Professor Baird has it 1541; Alfred Newton 1524, and so on. [27] Leland's Collectanea, (1541). [28] _Dugdale._ "Origines Juridiciales." [29] Shufeldt, R. W. "The Ancestry of the American Turkey," _Shooting and Fishing_, Vol. 24, No. 13, New York, July 14, 1898, p. 246. "Wild and Domesticated Turkeys," _Ibid._ No. 17, August 11, 1898, p. 331. "A Reply to the Turkey Hunters," _Ibid._ No. 23, September 22, 1898, pp, 451, 452. "The Wild Turkey of Arizona," _Ibid._ Vol. 32, No. 5, New York, May 22, 1902, pp. 108, 109. [30] Nelson, E. W. "Description of a New Subspecies of _Meleagris gallopavo_ and proposed changes in the nomenclature of certain North American birds." Auk, XVII, April 1900, pp. 120-123. [31] Among the luxuries belonging to the high condition of civilization exhibited by the Mexican nation at the time of the Spanish conquest was the possession of Montezuma by one of the most extensive zoölogical gardens on record, numbering nearly all the animals of that country, with others brought at much expense from great distances, and it is stated that turkeys were supplied as food in large numbers daily to the beasts of prey in the menagerie of the Mexican Emperor. (Baird, _ibid._ pp. 288, 289.) [32] Ogilvie-Grant, W. R. "A Hand-book to the Game-Birds." (Lloyd's Nat. Hist., London, 1897, pp. 103-111.) Genus _Meleagris_. Describes briefly some of the North American Turkeys, and also _M. ocellata_ (full page colored figure). Nest and eggs of all described in brief. [33] Michaux, F. "Travels in N. Amer." 1802 Eng. Trans., p. 217. See also the following: Blyth, E., "Ann. and Mag. of Nat. Hist.," 1847, vol. xx., p 391. This author points out that these turkeys in India are flightless, black in color, small, and the appendage over the bill of great size. [34] Dixon, E. S. "Ornamental Poultry," 1818, p. 34. This author also noted the interesting fact that the female of the domesticated turkey sometimes has the tuft of hair on her breast like the male. Bechstein refers to the old German fable or superstition that a hen turkey lays as many eggs as the gobbler has feathers in the under tail-coverts, which, as we know, vary in number. (Naturgesch. Deutschlands, B iii, 1793, s. 309.). [35] "Gardener's Chronicle," 1852, p. 699. [36] Darwin, Charles. "Animals and Plants Under Domestication," Vol. 1, 1868, pp. 352-355. Other facts of this character are set forth here which are of interest in the present connection. [37] Darwin, Charles. "The Origin of Species," 1880, pp. 70, 158. He also shows that the young of wild turkey are instinctively wild. [38] Woodhouse, Dr. (Amer. Nat. vii, 1873, p, 326.). [39] Henshaw, H. W. Rept. Geogr. and Geol. Expl. and Surv. West of the 100th meridian. 1875. Chap. III. The Ornith. Coll. 1871-1874, p. 435. [40] Caton, J. D. "The Wild Turkey and Its Domestication." Amer. Nat. xi, No. 6, 1877, pp. 321-330, also _Ibid._ vii, 1873, where this author states that "The vision of the wild turkey is very acute but the sense of smell is very dull." (p. 431.) [41] Bendire, Charles, "Life Histories of North American Birds with Special Reference to Their Breeding Habits and Eggs." Washington, Govmt. Printing Office, 1892. [42] Some of the English books contain descriptions of the eggs of our wild turkeys, as for example "A Hand-book to the Game-birds." By W. R. Ogilvie-Grant. (Lloyd's Nat. Hist.) London, 1897, pp. 103-111. [43] Shufeldt, R. W. "Osteology of Birds," Education Dept. Bull. No. 447, Albany, N. Y., May 15, 1909. N. Y. State Mus. Bull. 130, pp. 222-224; based upon a former contribution which appeared in _The Journal of Comparative Medicine and Surgery_, July, 1887, entitled "A Critical Comparison of a Series of Skulls of the Wild and Domesticated Turkeys." (_Meleagris gallopavo silvestris_ and _M. domestica_.) CHAPTER V BREAST SPONGE--SHREWDNESS Nature has provided the old gobbler with a very useful appendage. Audubon calls it the "breast sponge," and it covers the entire upper part of the breast and crop-cavity. This curious arrangement consists of a thick mass of cellular tissue, and its purpose is to act as a reservoir to hold surplus oil or fat. It is quite interesting to study its function, and it is a very important one for the gobbler. This appendage is not found on the hen or yearling gobbler. At the beginning of the gobbling season, about March 1st, this breast sponge is full of rich, sweet fat, and the gobbler is plump in flesh; but as the season advances and he continues to gobble, strut, and worry the hens, his plumpness is reduced, and finally the bird becomes emaciated and lean. Often during the whole day he gobbles and struts about, making love to the hens, and at this time he eats almost nothing, being kept alive largely by drawing on his reservoir of fat. As the gobbler begins to grow lean, his flesh becomes rank and wholly unfit for food, and one should never be killed at this time. It is a fact that the young male turkeys gobble but seldom, if at all, the first year. Neither do these young birds possess the breast sponge, or reservoir to hold fat, and consequently they are unfit to mate with the hens. The hens visit the males every day or alternate days; consequently, if among the gobblers there are no mature birds, the eggs laid are not fertile. I wish every hunter, sportsman, and farmer could read these lines, and recognize the importance of sparing at least one of the adult male turkeys in each locality. The benefit of such a policy would soon be apparent in the increase of the turkeys. I dwell at length on this point in order to make clear the necessity of sparing some old gobblers in each section. It has frequently been stated that the wild turkey will not live and propagate within the haunts of man. This depends upon how the birds are treated. No bird or animal can survive eternal persecution. There is no trouble about the birds thriving in a settled community, if the proper territory is set apart for their use, and proper protection given. The territory should consist of a few acres of woodland, or of some broken ground, thicket, or swamp to afford a little cover. In such a retreat, a trio of wild turkeys may be turned loose, and in a few years, if properly protected, the vicinity would be stocked with them. I have ample evidence that wild turkeys will not shrink from civilization. It is the trapping, snaring, baiting, and killing of all old gobblers that decimates their numbers, not the legitimate hunting by sportsmen. [Illustration: Note the full chest of the gobbler on the left. This is the breast sponge. (Photographed in March)] The shrewdness of the turkey is shown by his having no fear of the peaceable farmer at the plow, no more than the crow or the blackbird has. The wild turkey will go into the open field and glean food from the stubble or upturned furrows in full view of the plowman. This I have often seen, and I will cite one incident of this kind, which came under my observation some time ago when hunting in the State of Mississippi. It was a clear, beautiful morning in the month of March. Three old turkeys were gobbling in different directions, along a creek in a swamp, which was about half a mile wide, with fields on each side. Having selected the one I thought the oldest and biggest, I approached it as near as I dared; then, hiding myself in the brush, I began to call. In a short time the other two birds quit gobbling and came quickly to the call, while the one I had chosen continued his gobbling, but in the same place as when first heard. Suddenly I heard "_Put-put_" directly behind me; turning my head, I saw, within twenty paces of me, a fine gobbler. "_Put_"--then he was gone. This caused the one gobbling in front of me to become suspicious. He refused to come an inch nearer, and, having heard that alarm, "_put_," he began to make a detour in order to gain a certain heavily wooded ridge. To do this, without getting too near the spot where he heard the warning cry of his comrade, he had to go over a high rail fence, going through a part of the field just plowed up, while the plowman was there at work in his shirt sleeves, not over one hundred yards away and in full view of the gobbler. The man was moving all the time and frequently holloaing to his mules, "Whoa," "Gee," or "Haw," in such a loud voice that one could hear him a long distance. The turkey would gobble every time the plowman would holloa. He appeared to be perfectly fearless of the plowman, but was employing all his sagacity to avoid the spot where I was. I could not understand this at first, but discovered the reason a little later. The bird had reached the field and was flanking me, but I could not see it on account of the undergrowth. I rose, and by making a detour of about two hundred yards around the angle of the field, keeping well in the woods, I finally discovered the gobbler striding sedately across the field between me and the plowman, who was busily engaged in attending to his furrows, still loudly holloaing from time to time. The gobbler at intervals stopped, strutted, gobbled, and then proceeded on its way. Seeing that I could get no nearer to him, I waited until he was about to cross the fence, when I dropped by a stump, lifted my rifle, and waited for him to mount the fence. This he was some time in doing, but I finally heard the _flop, flop_, when his fine form with long, pendent beard was seen broadside on by me on the top rail, about eighty-five yards away. In a second the bead of my rifle covered the spot at the wing, and, as I fired, the bird tumbled dead into the field. It was a grand old specimen, and on examining it dry blood was discovered where a buckshot had passed through its leg. There was another shot across the rump, and a third had creased the back of the neck near the head. In my opinion, the bird hearing the "_put-put_" of the gobbler who came up behind me suspected a hidden enemy, and, having lately been wounded, thought it best to give suspicious places a wide berth. There are thousands of acres in the South which were once cultivated, but which are now abandoned and growing up with timber, brush, and grass. Such country affords splendid opportunity for the rearing and perpetuation of the wild turkey. These lands are vastly superior for this purpose than are the solid primeval forests, inasmuch as they afford a great variety of summer food, such as green, tender herbage, berries of many kind, grasshoppers by the million, and other insects in which the turkeys delight. Such a country also affords good nesting retreats, with brier-patches and straw where the nest may be safely hidden, and where the young birds may secure safe hiding places from animals and birds of prey; but alas! at present not from trappers, baiters, and pot hunters. Check these, and the abandoned plantations of the South would soon be alive with turkeys. CHAPTER VI SOCIAL RELATIONS--NESTING--THE YOUNG BIRDS The wild turkey differs in its domestic relations from the majority of birds, for it does not take one partner or companion, or pair off in the spring, as do most gallinaceous birds. Charles Hallock has stated that turkeys pair off in the spring. I beg to differ with Mr. Hallock. The male turkey does not confine himself to one mate. He is a veritable Mormon or Turk, polygamous in the extreme, and desires above all a well-filled harem. He cares not a bit for the rearing or training of his family; in fact, it has been alleged that he follows his mates to their nests and destroys and eats the eggs. This I do not believe, nor will I accuse him of such conduct. He is a vain bird and craves admiration, and acts as if he were a royal prince and a genuine dude, and he will have admiration though it costs him his life. He is a gay Lothario and will covet and steal his neighbors' wives and daughters; and if his neighbors protest, will fight to the finish. He is artful, cunning, and sly, at the same time a stupendous fool. One day no art can persuade him to approach you, no matter how persuasively or persistently you call; the next day he will walk boldly up to the gun at the first call and be shot. He has no sentiment beyond a dudish and pompous admiration for himself, and he covets every hen he sees. He will stand for hours in a small sunny place, striving to attract the attention of the hens by strutting, gobbling, blowing, and whining, until he nearly starves to death. I believe he would almost rather be dead than to have a cloudy day, when he is deprived of seeing the sun shining on his glossy plumage; and if it rains, he is the most disconsolate creature on the face of the earth. [Illustration: Nest located in thick brush on top of a ridge in Louisiana] The methods employed by the wild turkey hen in nesting and rearing a family do not differ materially from those of the tame turkey. The nest itself is a simple affair, fashioned as if made in a hurry, and consists of a depression scratched in the earth to fit her body comfortably, then a few dry leaves are scratched in to line the excavation. Again, the nest may be under an old fallen treetop or tussock of tall grass, or beside an old log, against which sundry brush, leaves, and grass have drifted, or in an open stubble field or prairie. There is one precaution the hen never neglects, however slovenly the nest is built; this is to completely cover her eggs with leaves or grass on leaving the nest. This is done to protect them from predaceous beasts and birds, particularly from that ubiquitous thief and villain, the crow. The eggs, usually from eight to fifteen in number, are quite pointed at one end, a little smaller than the eggs of the domesticated turkey, showing considerable variation in size and shape. In color they are uniform cream, sometimes yellowish, and, when quite fresh, with a decided pink cast, spotted and blotched all over with reddish brown and sometimes lilac. The period of incubation is four weeks. On its first appearance the young wild turkey is covered with a suit of light gray fluffy down, dotted with dusky spots, and with two dusky stripes from the top of the head, down the sides of the back to the rump; but this is soon replaced by a covering of deciduous feathers, and this in turn by the permanent suit at molting in August and September. The first crop of feathers which takes the place of the down grow very rapidly, assuming in their maturity the precise shape and color of the subsequent and permanent growth, and at three months the turkey is in appearance the same as one of nine months. The young bird of two or three pounds weight has the same outline of form as the yearling, but the little fellow in down bears a striking resemblance to a young ostrich. The deciduous feathers mature quickly, and the quill-ends dry before the young bird is a quarter grown; hence the feathers grow no more. But the bird grows until molting-time arrives, when the young fowl, if a gobbler, will weigh from seven to nine pounds. The molting season comes on apace, and the bird is out of humor; for its clothes, as it were, do not fit, the mosquitoes and ticks bite it, and the deciduous quills of the wings begin to get loose and drop out, one at a time at long intervals, so that some feathers are growing while others are falling. This is also true of the body covering. The tail becomes snaggled and awry, and at the time the young turkey presents anything but a pleasing appearance. The molting begins in August, and it is the last of December before the full second suit of feathers is completed. It is the irregular growth of the feathers that often deceives the hunter as to the age of the fowl. Once a friend of mine and I, after a morning's hunt, stopped to rest and got into our boat. He had three fine turkeys, the time being early in November, and he remarked that he wished he had killed at least one gobbler to put with his hens. On examination I showed him that two of his three were young gobblers and the third an old hen, although the birds were about the same size and the plumage almost identical. The tuft or beard does not appear on the young gobbler even in the Southern climate until late in October or November, nor have I known them to gobble or strut at this early age, although the tame ones sometimes do. The gobbler's beard grows quite rapidly until the end of the third year, and then slowly until eleven or twelve inches long, when it seems to stop. It may be owing to its wearing off at the lower end by dragging on the ground while feeding; but a close inspection will not substantiate this, for the hairs at the extreme end of the beard are blunt and rounding, and do not indicate wear from friction. The young gobbler's beard is two inches long by the end of November of the first year of his life. By March it is three inches long and stands out of the feathers one inch. At the end of the second year it is five inches long, and at three years about eight inches long. [Illustration: Hen, wild turkey, and three young. On account of the extreme shyness of the mother, young turkeys are very hard to photograph] Hens have beards only in rare cases, but not in one out of a hundred will a hen be found with one and then never more than four inches long. I have seen gobblers with two or three beards, and one at Eagle Lake, Texas, with five separate, long and distinct beards; but such cases are freaks. I once called up and killed a turkey hen on the banks of the Trinity River, in Texas, which was covered with precisely the same bronze feathers that distinguish the gobbler--the same thick, velvety black satin breast, and the same beautifully decorated neck and head, except the white turban cap of the gobbler. She had a five-inch beard and looked in every way like a gobbler, except being smaller in size. She weighed twelve pounds and had the form of the hen, the legs of a hen, and was a hen, but the most gaudy and beautiful specimen I ever saw. Possibly this was a barren hen, as she had all the visible characteristics of the male, but she did not gobble, she yelped. The parasite which troubles the turkey is much larger than those which infest chickens. It is yellow in color and crawls rapidly. Turkeys have a habit of rolling themselves in dust and ashes to remove vermin from the skin and feathers; but I believe a bath of dry wood ashes, where an old log or stump has been burned, is preferred by them on account of the cleansing effect of the ashes. When the young turkeys are four or five months old they are fairly independent of their mother, and become quite self-reliant, so far as roosting, feeding, and flying into trees is concerned. They are not, however, entirely independent of their mother's care until fully grown, but usually the entire brood remains under her guidance more or less until December or January. At this time the young males begin to follow the ways of the old gobbler, separating from the females and going in bands by themselves; therefore there are at this time three classes of turkeys socially (if I may use the term) in the same district. These flocks will incidentally meet, and will feed and scratch together for an hour or so; they then separate into their respective classes and disappear in different directions with great system and little ado. CHAPTER VII ASSOCIATION OF SEXES Once I saw fifteen gobblers feeding in a hollow between two ridges. I dismounted from my horse, crawling to the brow of the hill in order that I might peep over and have a good look at them. I had no gun with me at the time, so I lay upon the ground and watched the turkeys feeding and scratching for about two hours. They were apparently all of one flock; but finally a party of nine, all of which were old gobblers, having long beards that trailed upon the ground as they fed, withdrew in one direction, while the other six, which were young or yearling gobblers and beardless, departed in another direction. This was done without any signal that I could discern. A few days later, as I was passing the same place with my rifle, I found, right on the identical spot, the same fifteen gobblers, nine old ones and six young ones, scratching and feeding as before. They soon began to feed away from me, and as I saw they were to pass over a ridge, I fired at the nearest, which was about one hundred and twenty-five yards away, tumbling him over, and the rest of the flock ran away. Two weeks after this incident I was driving in the same woods for deer. The hounds flushed one detachment of this flock of turkeys (the nine old gobblers), which took refuge in the trees; and my brother, who was on a stand near where they lit, shot two of the turkeys as they perched in the tall pines within rifle shot of him. These birds were noble fellows, weighing twenty-one pounds each, and they were fat. This was in January. As shown, the young gobbler will occasionally associate with the old ones, but he seldom remains long in their company. Why this is so I do not know, as I have never known them to quarrel, jostle, fight, or disagree in any way. I have come to the conclusion that the cause of the separation must be the want of congeniality between old age and youth. This division and separation into classes embraces about three months, December, January, and February, and part of March. The hens are more sociable and gregarious in their ways than the males, collecting in immense flocks. The flocks of the gobblers are seldom more than fifteen or twenty, while I have seen from thirty to seventy-five hens in a single flock in which there was not a single male. I imagine the greater size of the flocks containing females to be on account of the gobblers being killed in far greater numbers than the hens. Just before the time of the final separation of the sexes, the young males, their sisters, their mothers, and other old hens that have lost their broods, associate in a very sociable manner, traveling and roosting together. Audubon says: "The turkey is irregularly migratory, as well as irregularly gregarious. In relation to the first of these circumstances, I have to state that whenever the mast in one part of the country happens to exceed that of another, the turkeys are insensibly led to that spot by gradually meeting in their haunts with more fruit the nearer they advance toward the places of greatest plenty. In this manner flock follows flock until one district is entirely deserted while another is overflowed by them, but as these migrations are irregular, and extend over vast expanse of country, it is necessary that I should describe the manner in which they take place. About the beginning of October, when scarcely any seed and fruit has yet fallen from the trees, the birds assemble in flocks and gradually move toward the rich bottom lands of the Ohio and the Mississippi. The males, or as they are commonly called, gobblers, associate in parties from ten to one hundred, and search for food apart from the females, while the latter are singly advancing, each with its brood about two thirds grown, or in connection with other families, often amounting to seventy or eighty individuals all intent on shunning the old cocks, which, even when the young brood have attained this size, will fight and often destroy them by repeated blows on the head." This last assertion of the great author I feel obliged to criticise. In my vast experience with the turkey I have never met with anything to justify such a statement. I have never seen an old gobbler attempt to fight a young one, from the egg to maturity. It is wholly unnatural from the fact that the old birds are never in a bellicose temper except during the love season or gobbling time in the spring, when jealousies arise from sexual instincts. Not in any instance, however, have I known of one turkey killing another. I have often seen two old gobblers strut up to each other, blow, puff, and rub their sides together. I watched, expecting to see a crash, but there was not a motion to strike, and this was in the love season while there was a bevy of hens all around. They do not fight in the summer, fall, and winter, but of course now and then old gobblers will fight in the beginning of the mating season. The young broods and their mothers do not associate at any time with the old gobblers, except as I have described, neither do they run away from them in fear. If all that Audubon and other writers say about the wild gobbler were believed, he would be universally regarded as the most bellicose and brutal villain in the bird world; for, according to various writers, he spends the greater part of his time making war on his own kind, besides murdering his tender offspring. Certainly there is no bird more affectionate to its female under the same condition, or more gallant and proud of her company, and it does not seem likely that he would wilfully destroy in cold blood his own family. The old hens that have not succeeded in raising a brood of their own will join hens who have, and assist in rearing the young. Again, Audubon says: "When they come upon a river they partake themselves to the highest eminence, and there often remain a day or two as if in consultation. During this time the males are heard gobbling, calling, and making much ado, and are seen strutting about as if to raise the courage to a pitch before the emergency of crossing." [Illustration: The beginning of the strut. These gobblers are strutting before the camera hidden by brush in an endeavor to attract the hen turkey whose love call the camera man is imitating with his "caller."] I will say in this connection that turkeys may so act in rare instances, if the stream be exceptionally wide, thus delaying their progress for an hour; for turkeys do not like to fly under any conditions, nor will they use their wings save when necessary. But I have never seen a river that they could not easily cross, starting at the water's edge, rising as they fly, and alighting in the tops of the trees on the opposite bank. Mr. J. K. Renaud, of New Orleans, and I, while paddling a skiff up a small lake in Alabama, once counted a flock of sixteen turkeys flying across the lake some distance ahead of us. We noticed that they just barely skimmed over the water and rose to the top of a higher ridge on the opposite side, where they alighted, and not even one touched the water. This lake was probably three hundred yards wide. Audubon says: "Even the females and young assume something of the pompous demeanor, spreading their tails and running around each other, purring loudly, and making extravagant leaps. I have seen this running round, purring, dancing, and 'ring-around a rosy' in the spring, but not to any extent at any other time." As many of my readers have never had the opportunity or pleasure of reading the beautiful and expressive lines of Audubon on the wild turkey, I will be pardoned if I introduce some extracts from this great author. He says: "As early as the middle of February they [the turkeys] begin to experience the impulse of propagation. The females separate and fly from the males. The latter strenuously pursue and begin to gobble, or utter the notes of exultation. The sexes roost apart, but at no great distance from each other. When a female utters a call-note, all the gobblers within hearing return the sound, rolling note after note with as much rapidity as if they intended to emit the last and first together, not with the spread tails as when fluttering round the hens on the ground, or practising on the branches of trees on which they have roosted for the night, but much in the manner of the domestic turkey when an unusual noise elicits its singular hubbub." By this he means, when the wild gobbler on the roost hears the call of the hen, he gobbles, and dances on the limb without strutting, the same as the tame gobbler will gobble when hearing a shrill whistle or other sudden acute sound, without evincing any amorous feelings; but it is not always so. I have often seen the wild gobbler strut on his roost, and I have shot them in such an act when in full round strut. Audubon also says: "If the call of the hen is from the ground, all the males immediately fly toward the spot, and the moment they reach it, whether the hen be in sight or not, spread out and erect their tails, draw the head back on the shoulders, depress the wings with a quivering motion, and strut pompously about, emitting at the same time successions of puffs from their lungs, stopping now and then to listen and look, but whether they spy females or not, continue to puff and strut, moving with as much celerity as their ideas of ceremony seem to admit." Now, here are some of the greatest errors of the great naturalist in all his turkey lore, or else the wild turkey gobbler has materially changed his ways. The gobblers do not immediately fly to the call of the hen, and no turkey hunter of experience will admit this. There are perhaps instances, extremely rare ones though, when a gobbler will fly instantly to a hen on hearing her call, or even at sight of her. Only in two instances in my life have I witnessed it, and on both occasions the gobblers were young birds two years old, and acted a good deal like a schoolboy with his first sweetheart--who smiles and laughs at everything she says and does. With the young turkey it may be his first gobble on hearing the quaver of the hen. He is made crazy, and may unceremoniously rush to any sound that in the least resembles the cry of the hen, without a thought of what he is about or of the possible consequences. This is generally the kind of gobbler the novice in calling bags as his first, a two-year-old with a five-inch beard. In the early morning, during the spring, a gobbler will fly from his roost to the ground, strutting and gobbling, whether a hen is in sight or not; this is done to attract the hens, and it is then you will hear the puffs to which Audubon refers. This sound is produced by the gobbler in expelling the air from its lungs, at the beginning of the strut, the sounds and motions of which have never been satisfactorily described. While going through the strut the gobbler produces a number of notes and motions that are of interest; first, the wings are drooped until the first six or eight feathers at the end of the wings touch the ground; at the same time the tail is spread until like an open fan and erected at right angles to the body; the neck is drawn down and back until the head rests against the shoulder feathers, and the body feathers are all thrown forward until they stand about at right angles to their normal place. At the same time the body is inflated with air, which, with the drooping wings, spread tail, and ruffled feathers, gives the bird the appearance of a big ball. Having blown himself up to the full capacity of his skin, the gobbler suddenly releases the air, making a puff exactly as if a person, having inflated the cheeks to their full capacity, suddenly opens the mouth. As the puff is given, the bird steps quickly forward four or five paces, dragging the ends of the stiff wing feathers along the ground, making a rasping sound; he throws forward his chest, and, gradually contracting the muscles, forces the air from his body with a low, rumbling boom, the feathers resuming their normal position as the air is expelled. Three distinct sounds are produced: "_Puff, cluck, b-o-o-r-r-r-m-i_." At the termination of the gobbling season the primaries of the wings, which are used to produce the cluck, are badly worn by the continued dragging on the ground. "While thus occupied," continues Audubon, "the males often encounter each other, and desperate battles take place, ending in bloodshed and often in the loss of many lives, the weaker falling under repeated blows inflicted upon their heads by the stronger. I have often been much diverted while watching two males in fierce conflict by seeing them move alternately back and forth as either had obtained a better hold, their wings dropping, tails partly raised, body feathers ruffled, and heads covered with blood. If in their struggle and gasps for breath one of them should lose his hold, his chance is over, for the other, still holding fast, hits him violently with his spurs and wings and in a few moments brings him to the ground. The moment he is dead the conqueror treads him underfoot; but what is stranger, not with hatred, but with all the emotions he employed in caressing the female." I differ with Audubon, not in the case of the conqueror using affectionate conduct upon a fallen foe, should he get him down, as that is truly a freak with them; but I have not seen such a performance with wild birds, although I have noticed the domestic gobbler act similarly toward the body of a dead wild gobbler that I had placed before him on the ground. I have very often brought such a bird into the presence of a tame one, when, at the very sight of the dead bird on my back, the tame one would begin to droop his wings, purr, bow his neck, and bristle for a fight, and at once pounce upon the dead bird, even pounding me until I laid it down and allowed him to vent his rage by pounding it. After this he would begin to strut and gobble, and the red of his head becoming intense he would go through the caressing motions. More often though, under the circumstances, the tame bird would, at the sight of the dead wild gobbler, retire a little way and strut in a furious manner for an hour or two. This does not apply to one instance or individual, but many times in many places. I must differ with Audubon as to the results of these conflicts ever being fatal. I have seen many encounters as he describes, but have never in all my life seen one gobbler killed by another, or even crippled, although I have seen two or three birds fight together for hours at a time. Nor have I ever found a gobbler dead in the woods as a result of such an encounter, or even in a worried condition. I have killed many old gobblers and found their heads and necks covered with blood, with spur punctures all over their breasts; but this never stopped them from gobbling, nor are these wounds deep, as the spur, which is an inch and a quarter long in the oldest of them, can only penetrate the skin of the body after passing through the heavy mail of thick, tough feathers. Another proof that the gobblers in my hunting grounds were not killed this way is that I should have missed them. How would you know? you might ask. In the same way that a stock owner knows when he misses a yearling from his herd. Being constantly in the woods, I knew every gobbler and his age (at least the length of his beard) within a radius of several miles, although there be three in one locality and five in another. During the time they were in flocks or bands, if one were missing, surely I would find it out ere long; and it has never yet happened that, when one was missing, I could not trace it to a gunshot and not to turkey homicide. I will not flatly dispute that there have been such incidents as cited by Audubon, met with by others; but I do claim that murder is not common among turkeys, and such incidents must be extremely rare, or I would have witnessed them. I can see no way by which one turkey can kill another; for, as I have said before, the spur is not long enough except to barely penetrate the thick feathers, and the biting and pinching of the tough skin on the neck and head could not cause contusion sufficient to produce death, nor are the blows from the wings sufficiently severe to break bones. CHAPTER VIII ITS ENEMIES AND FOOD No bird on earth can boast of more or a greater variety of enemies than the wild turkey. The chief of them all is the genus _Homo_, with his sundry and sure methods of destruction. After man comes a host of wild beasts and birds, including the lynx, coyote, wolf, fox, mink, coon, skunk, opossum, rat, both golden and white-headed eagles, goshawk, Cooper's and other hawks, horned owl, crow, etc., all of whom prey more or less upon the poor birds from the egg to maturity. There is never a moment in the poor turkey's life that eternal vigilance is not the price of its existence. Still, many pass the gauntlet and live to a great age, the limit of which no man has discovered. I have been a lifelong hunter of all sorts of game indigenous to the Southern States, and I have never seen or heard of a wild turkey dying a natural death, nor have I heard of any disease or epidemic among them; and were it not for the eternal war upon this fast-diminishing species, especially by man, they would be as plentiful now as fifty years ago. The first in the list of natural enemies of the turkey, if we admit the testimony and belief of nearly every turkey hunter, is the common lynx or wildcat, often known as bobcat. Many hunters believe that of all the enemies of the wild turkey the wildcat is the chief. In all my experience I have never seen a turkey attacked by a cat, nor have I ever seen the skeleton of a turkey which had been killed and eaten by cats. I have never seen a cat crouching and creeping up on a turkey, nor have I had one of them come to me while calling, and I have had more than fifty years' experience in turkey hunting in all the Gulf States where the cat is common. Numerous persons of undoubted veracity, however, have assured me that they have seen cats creep up near them while calling turkeys, and in some instances the evidence seems conclusive that the cat had no other business than to steal up and pounce upon the turkey. Like any other carnivorous beast, the lynx may partake of turkey as an occasional repast, if they are thrown in his way, but this is an exception and not the rule. My brother, who is a well-known turkey hunter in Mississippi, has furnished me with the following incident: As he sat on the bank of a small lagoon, in the early morning, with his back against a log that lay across the lagoon, calling a gobbler which was slow to come, he heard the soft tread of something on the log very near his head, on the side next to the lagoon. Turning slowly, he saw a large cat within three feet of him, apparently having crossed the water in an attempt to spring upon the supposed turkey that had been yelping on that side. When my brother faced the cat, it beat a rapid retreat, and my brother, springing to his feet, waited until the cat left the log, thus turning its side toward him, when he fired, killing it on the spot. There is little doubt but that in another minute the cat would have jumped on my brother's head. Another time he was sitting calling a gobbler, when suddenly he heard a growling and purring noise in the cane near him. Presently there appeared three large cats, but they seemed to be playing or having a love feast, as they walked about, sprang upon each other, squalled, scratched, springing up the trees, then down again, until he broke up the fun by a couple of shots that laid out a brace of them. Another time he was calling a gobbler which was gobbling vehemently, when suddenly there was a great commotion among the turkeys, clucking and flying up in trees. A cat then appeared out of the cane and was shot. Now, does this prove, in either of the last two cases, that the cats were trying to catch the turkeys? By no means. For, had the cats been trying to get a turkey, they would not have shown themselves. I believe the cats were simply lounging about in quest of rabbits or squirrels, and happened to pass near the birds, which became frightened at the appearance of so uncanny a visitor. In the last incident, had the cat been attempting to seize or pounce upon the turkeys, they would not have gobbled again, but would have left the place in a hurry. Another reason why I claim that wildcats do not habitually feed on turkeys is, that one may find a given number of turkeys in a piece of woodland, and never miss one from the flock, unless trapped or killed by a gun--that is, after they are grown. I will cite another incident connected with the habits of the lynx or wildcat that came under my observation while in quest of wild turkeys in the State of Alabama, in company with my friend John K. Renaud, of New Orleans, an enthusiastic and inveterate sportsman. We were in the Tombigbee Swamp, and one morning, while sitting together in a fallen treetop, calling turkeys, our backs against a log, I felt something soft against my hip. As it felt a little warmer than the earth should feel, I pulled away the leaves with my hands, and there lay an immense cane rabbit dead. Upon pulling it out, I found its head was eaten off close to the shoulders, with no other part touched. This was the work of a lynx. Two days after, we were sitting by another log, not over a hundred yards from the first spot, and for the same purpose. I found there a similar object, a large rabbit freshly killed and half eaten, the head and forepart of the body gone. That was the work of a cat. There were plenty of turkeys frequenting that ridge every day, but never one of them was taken by a lynx, as I knew positively just how many gobblers and hens there were in that piece of woods. I do not think wildcats ever eat the eggs of the turkey when they come across a nest of them; they may catch the sitting birds, but all other animals named in the foregoing list eagerly eat the eggs, if they are lucky enough to find the nests; this is also true of the crow, who, on locating a nest, will watch until the mother leaves it in search of food, when it will quickly destroy as many eggs as possible. All the animals and birds named will catch the young turkeys, and the larger birds and animals will kill grown turkeys when they can catch them. Snakes give the turkey very little trouble. I do not believe any snake we have can swallow a turkey egg, except possibly the largest of the colubers (chicken snakes). I have never met one that was guilty of it, although I have seen them swallow the eggs of the tame turkey. Mr. John Hamilton, who has had great experience as a turkey hunter, tells me of seeing horned owls catch turkeys in the Brazos Bottoms in Texas, a number of times, as follows: On going into the woods before daylight, and, taking a stand near some known turkey roost, to be ready to call them on their leaving the roost, he has, a number of times, been led directly to the tree in which the turkeys were roosting by a horned owl who was after a turkey for breakfast. By walking quietly under the tree, and getting the birds outlined against the sky, he could see what was going on. Turkeys prefer to roost on limbs parallel to the ground, and the owl, selecting a hen perched on a suitable limb, would alight on the same limb between her and the trunk of the tree, moving sedately along the limb toward the victim, and when very near her would voice a low "_who, who_." The turkey, not liking the nearness of such a neighbor, who spoke in such sepulchral tones, would reply, "_Quit, quit_," and move farther out on the limb. After a few moments the owl would again sidle up to the hen, repeating his first question, "_Who, who_." "_Quit, quit_," would answer Miss Turkey, moving a little farther out on the limb. This would be kept up until the end of the limb was reached and the turkey would be obliged to fly, and then the owl would catch her. From personal observation I know horned owls always push chickens from the roosts and catch them while on the wing. A great destroyer of the turkey is rain and long wet spells, just after they are hatched in the months of May and June. I have always noticed that, if these months were reasonably dry, there would be plenty of turkeys and quail the following fall. After all, the weather controls the crops of turkeys more than all else. The local range of the wild turkey varies in proportion as the food supply is generous or scanty. If food is plentiful, the turkey remains near where hatched, and does not make extensive rambles, its daily journeys being limited to a mile or so, and often to not a fourth of that distance. I can not agree with writers who claim that wild turkeys are constantly on the move, travelling the country over with no intention of ever stopping. Of course, when the food supply is limited and scant, as during the seasons of dearth of mast, the turkeys are necessarily compelled to wander farther in order to secure sufficient food; but they will always return to their native haunts when their appetites are appeased. [Illustration: The chief of all his enemies is the "Genus homo"] In the early morning, all things being favorable, their first move after leaving the roost is in search of food, which search they undertake with characteristic vigor and energy, scratching and turning over the dry leaves and decaying vegetation. Two kinds of food are thus gained: various seed or mast, fallen from the trees and bushes, and all manner of insects, of both of which they are very fond, and which constitute a large part of their food supply. There is no bird of the gallinaceous order that requires and destroys more insects than wild turkeys. They will scratch with great earnestness over a given space, then, all at once, start off, moving rapidly, sometimes raising their broad wings and flapping them against their sides, as if to stretch, while others leap and skip and waltz about. Then they will go in one direction for some distance. Suddenly, one finds a morsel of some kind to eat, and begins to scratch among the leaves, the whole flock doing likewise, and they will keep this up until a large space, perhaps half an acre of land, is so gone over. What induces them to scratch up one place so thoroughly and leave others untouched would seem a mystery to the inexperienced; but close observation will show that such scratching indicates the presence of some kind of food under the leaves. It may be the nuts of the beech, oak, chestnut, chinquapin, black or sweet gum tree, pecan nut, grape, or muscadine seed. If one will observe the scratchings, it will be seen that they occur under one or another of such trees or vines. Thus they travel on, stopping to scratch at intervals until their crops are filled. Under certain conditions, wild turkeys are compelled to seek numerous sources to obtain a supply of food, as when there is a failure of the mast crop, which affords the principal supply of their food, or when there is an overflow of the great swamps or river bottoms, which turkeys so often inhabit. When such overflows occur, the turkeys are either forced to take up their abode in the trees, or to leave their feeding ground and retreat to the high lands that are not overflowed. In the latter case there is little trouble in procuring food by scratching in the dry leaves or gleaning in the grain fields. But turkeys are hard to drive from their haunts, even by high waters, and more often than not they will stubbornly remain in the immediate locality of their favorite swamps and river bottoms by taking to the trees until the waters have subsided; they will persistently remain in the trees even for two or three months, with the water five to twenty-five feet in depth beneath them. At such times they subsist upon the green buds of the trees upon which they perch, and the few grapes and berry seeds that may remain attached to the vines which they can reach from the limbs. It is truly remarkable how long these birds can subsist and keep in fair flesh under such conditions. There is a critical time during these overflows, when turkeys are hard pressed in that they may obtain sufficient food to sustain life; this is when the rivers overflow in December, January, or February, before the buds have appeared or have become large enough to be of any value as food. Under these conditions they must fly from tree to tree until they reach dry ground, or starve to death. Although I have never known of a gobbler being thus starved to death, I have seen them so emaciated they could hardly stand. One incident of this sort I will relate: I found four very large old gobblers in an overflowed swamp on the Tombigbee River in Alabama, and as it was in February, it was too early in the year for herbage to begin the spring growth. The river had overflowed the bottoms suddenly, and it was a long way to dry land, perhaps three miles, so the turkeys could get little or nothing to sustain life. I shot one of these gobblers, not thinking of their probable condition, and found I had bagged a skeleton. If the bottoms are not over three miles wide, turkeys will usually, on approach of rising water, start for the dry ridges farther back from the river, and there remain until the waters steal upon them, when they will fly into the trees. Sometimes a ridge is an island at sundown when they go to roost, but is covered during the night, and when the morning comes there is no dry land in sight for the poor birds to alight upon. This is bewildering to them and presents a new state of affairs. If there be an old mother hen in the flock, she will at once take in the situation, and by certain significant clucks and a peculiar cackle, which is a part of their elaborate language, she will take wing and fly two or three hundred yards in the direction of dry land, alighting in the trees, when, after a rest, with another cluck or two, the party will continue in the same direction. This is kept up until the dry land is reached, when, with wild acclaim and a general cackle of exultation, they all alight on the ground and proceed at once, at a fearful rate, to scratch up the leaves in search of food. The hunter, aware of these habits after the swamps begin to overflow, will lose no opportunity for an early visit to the hummock at the margin of the backwaters. The turkeys do not remain near the edge of the overflow for any length of time, but very soon extend their range farther into the high forests and fields. They seem to know instinctively that it is unsafe to linger near the edge of the water. In case the overflow occurs in March or April, when the trees are full of fresh buds and blossoms, the turkeys have an easy time, living in the treetops, fluttering from branch to branch, gathering the tender buds and young leaves of such trees as the ash, hackberry, pin oak, and the yellow bloom of the birch, all of which are favorite foods, while of the beech and some other trees it is the fringe-like bloom they eat. They will remain in the trees out of sight of land for months if they have plenty of buds and young leaves to eat, and keep in fair flesh; but the flesh is not so palatable as when feeding on mast or grain. I once knew a flock of fifteen turkeys to remain in trees above an overflow for two months. I could see them daily from my cabin on the bank of a lake in Alabama, and could sit at my table and watch them fluttering as they fed on the hackberry buds. They were in sight of a dry, piney wood, and a flight of three hundred yards across a lake would have taken them to the dry land, but not once did they seem inclined to go to it. They remained in the trees until the water went down, and the next I saw of them was in an open plantation, with the lake on one side and the river on the other. The water had barely left the surface in places, and it was muddy and sloppy. They never once went to dry land, but returned to their swamp haunts as the water abated. On one occasion, as I was going down the river in my skiff, I saw and passed a great number of wild turkeys, one hundred or more, in small flocks in the timber near and along the river banks. The adjoining swamps were overflowed, with no land above the water. Most of these turkeys were sitting in cottonwood trees immediately on the river banks or a little way out in the timber, eating the buds. Many of them were in the trees that hung over the river, and, although most of the trees were leafless, thus exposing the turkeys to view, they remained there quite unconcerned while steamboats passed right by them. As I had three turkeys already in my boat, I felt no desire to molest them as I drifted by and under them. I passed right under some fine gobblers on their perches, not over thirty feet up, and they only looked curiously down at me; they seemed to be busily engaged in feeding, and sailed from tree to tree, keeping up a great stir and racket. It is a beautiful sight to watch a flock of wild turkeys budding, especially on beech buds. The branches of the beech trees are long and so limber that the birds with all their efforts can barely hold on to the tiny twigs while they gather their food; hence they are kept in a constant wobble and flutter, bobbing up and down with their wings spread out to sustain an equilibrium, and their broad tails waving and tossing, bringing them into all manner of attitudes, thus enabling the hunter to see and hear them a quarter of a mile through the timber. Some get upon very small limbs, then stretch out their long necks and pick the buds; others will spread out both wings for support and lie prone on a bunch of twigs while they feed. There is little or no trouble for the hunter to approach a flock so engaged and pick off his choice. They are so bent on eating that they take no note of what is going on around them; even if over dry land they will often remain in the trees half a day eating buds, if other food is scarce, and when tired or satiated they will sit calmly on some large limb and go to sleep or preen their feathers. This is one of the best opportunities afforded the crafty hunter with his good rifle to steal up behind a tree and deliberately drop one, as at this time the leaves are too small to afford much cover, and the turkeys are exposed to open view, giving the prettiest shots imaginable for the rifle. While this is one of the most successful and easiest ways of securing turkeys, there are few hunters who know enough about it to take advantage of it. Persons will often pass under trees in a turkey locality, when suddenly one or more turkeys will fly out. The hunter looks up, but sees only the turkeys on the wing, and cannot understand why they were in the trees at that time of day, as he has not flushed any. He wonders how they came to be there and does not know they were up there budding, having probably been there all the morning. The budding season lasts but a short time, if the birds are not forced to it by an overflow. On dry land it lasts a month or six weeks, for by that time the buds have matured into full-grown leaves, and are too old and tough for the birds to eat. CHAPTER IX HABITS OF ASSOCIATION AND ROOSTING After obtaining a supply of food, the wild turkeys become moody and careless, lounging about the sunny slopes if the weather be cool, or if it be hot, seeking the shade of the hummock or thicket, preening their feathers or wallowing in the dust. They thus pass the middle hours of the day in social harmony and restful abandon. About three or four o'clock in the afternoon the line of march is resumed in the direction of the roosting place, and they gather their evening meal as they journey along. They are excellent timekeepers, usually winding up the day at one of their favourite roosts; but in case this calculation is faulty and sundown overtakes them a mile or so from the desired spot, they will start on a run in single file, the old hens leading, and keep going rapidly until their destination is reached. They will then stop suddenly in a close group, peer about, uttering low purring sounds, while having a breathing spell from the long run. Having regained their composure, the old hens will sound several clucks in rapid succession, terminating in a guttural cackle, when the whole of the flock will take wing. With a wild roar, up they go in different directions, alighting in the largest trees with seldom more than two or three turkeys in a single tree. If they are not satisfied with their first selection of a roosting place, they will fly from tree to tree until a satisfactory place is found; then they settle down quietly for the night. Wild turkeys have a preference for roosting over water, and they will often go a long way in order to secure such a roost. The backwater from the overflowing streams, when it spreads out widely through the standing timber of the river bottoms, affords them great comfort; also the cypress ponds to be found in our Southern river districts. They evidently fancy that there is greater safety in such places. The turkey is happy when it can traverse the ridges, glades, and flats in a day's ramble from one watercourse to another, having a roosting place at one ridge one night and the next night at another. This sort of arrangement suits them admirably, as they dislike to roost in the same trees two or more consecutive nights. I have known them to make such regular changes as to roost in three or four different places in a week, bringing up at the same place not exceeding once or twice a week, and that on or about certain days. These are facts peculiar to the wild turkey, especially if localities are favorably arranged. But often they will roost very many nights near the same place. If the range is unlimited, however, they will seldom roost oftener than twice a week at a given spot. There are exceptions though, for I have known positively of old gobblers who took up their abode at a certain spot and roosted, if not in the same tree, in the same clump of trees, night after night and year after year with the persistent regularity of the peacock, which will roost on the same limb of a tree for ten or twenty years if undisturbed. When an old gobbler does take to this hermitlike custom, he is the most difficult bird to bag in the world. His life seems immune from attacks of any nature, and he seems to know the tactics of every hunter in the vicinity of his range. He keeps aloof from any old logs or stumps where an enemy may lurk, and never gobbles until daylight, so that he can take in every inch of his surroundings. I have killed from four to six old gobblers, in a given range, while trying to bag a certain stubborn old chap whose vigilance and good luck have saved him from bullets for years; but through patience and dogged persistence in the hunter he succumbed at last. Although some hold out longer in their reserved and retired course, I can truthfully say that I have yet to encounter one that can not be brought to the gun by fair and square calling. Many experienced and worthy hunters will criticise this assertion, and are honest in their convictions that I am in error; but I will take the dissenter to the haunts of the most astute old gobbler he may select, and call the turkey right up to the muzzle of his gun, or near enough to see the glint of his eye. A flock may be met one morning on the skirts of the backwater from an overflow river bottom, probably a flock of hens and gobblers together. There would be a great commotion among them and a general mixing up, yelping, and gobbling. On visiting this place the next morning one would not be seen or heard. Crossing to another lake or backwater, one might find the whole flock, or possibly the gobblers, with not a hen around. If in the gobbling season, and the males are gobbling, in less than half an hour the hens would be among them, but if not in the gobbling season the former may not meet the latter again for a month, as in the spring the sexes have no more attraction for each other than were they birds of entirely different groups. Except in the spring you may flush and scatter a flock of hens and gobblers, and after a reasonable wait begin to call with the notes of the hen. Not a gobbler will answer or notice you at all, but the hens will reply by yelping, squealing, and clucking. The gobblers meantime are as stolid as an Indian and as silent as a dead stump. Wait until the hens have gone, then begin the lingo of the gobbler and you find another result. [Illustration: An ideal turkey country. They will go a long way to roost in trees growing in water] Usually there are plenty of wild turkeys in the Southern river bottoms, in fall and winter, and there they remain until driven to the uplands by overflows, where they must subsist on pine mast, or remain in the trees over the water, and live on the young buds and tender leaves. I have repeatedly noticed this in the Tombigbee swamps in the State of Alabama. Those that do not go to the hills and pine forests will hug the margin of the overflow until the waters subside, when they will immediately return to their former haunts, however wet and muddy. When incubating time comes they seek the higher, dryer, and more open places, grassy and brush-covered abandoned plantations, there to carry out the duties of reproduction. After the season of incubation is at an end the gobblers cease, almost entirely, associating with the hens, collecting, as the summer advances, in bands of from two to a dozen. Thus they remain all through the summer, autumn and winter, acting the rôle of old bachelors or widowers, and never separating unless disturbed by an enemy. The females care for and rear the young broods, returning to the swamps or hummocks in the fall, where their favorite food has matured and shed. One of the last seasons I spent in the vicinity of the Tombigbee country in Alabama there were no grapes or muscadines in the bottoms, but a good pin oak crop of acorns, such as the turkeys like. In the higher woods there was a heavy black gum and berry crop, and there the turkeys were, while in the oak bottoms there was scarcely a flock. During the summer months, old gobblers, like old bucks, having banded together, become very friendly and attached to each other, feeding in perfect harmony. They stroll together wherever their inclinations may lead them, and are then very shy and retiring. One seldom sees them in the summer, but when they do it is generally in an open prairie or old field, eating blackberries, wallowing in an old ash hole, or chasing grasshoppers. These old bachelors do not get fat until fall, although they have an ample supply of food. They are lean and ugly and forlorn looking until after the molting season is over, in August and September, and their new bronze suits are donned; they then begin to fatten, and by December are in excellent condition of flesh and feathers, continuing to improve until the gobbling season returns next spring. These confirmed old bachelors will not associate with the other turkeys, but the old hens that have had their nests broken up and have reared no broods will associate all winter with the young broods and their mothers. I have often observed that these old patriarchs, as a rule, never associate with any other age or sex of turkeys. In summer you will often see an old gobbler or two with a flock of hens early in the morning; but see the same flock three hours later and he is not with them. In the early morning hours of spring, while there is a general gobbling and strutting parade, all ages and sexes mingle in the exuberance of the season and hour; but when this outburst of frolic and revelry is over, the different bands return to the sterner business of the day, that of searching for food. The old gobblers remain gobbling, strutting, gyrating round, picking at and teasing each other, or strumming now and then with the tip of wings, until a riot is precipitated and a fight ensues, in which two become engaged, while the more peaceful or timid quickly leave the vicinity. The gladiators then begin a tug of war, and after a few blows and jams with wings and spurs, one seizes another by the loose skin of the head, which is very limp, affording an excellent hold; then No. 2 gets his opponent by the nape of the neck, and they pull, push, and shove, standing on tiptoes, prancing and hauling away, each endeavoring to stretch his neck as high as possible, as if determined to pull the other's head off, while both necks are twisted around each other, their wattles aglow with the red sign of anger, while their hazel eyes sparkle with wrath. They writhe, twist, and haul away, until perhaps a quarter of an acre of earth is trampled, and keep it up until the foolish combat ends from sheer exhaustion, when one of them runs away. The victor, if not too much used up, having recovered breath and strength, will set up a gobbling and strutting that will cause the leaves of the trees to tremble. He thus proclaims his victory and assumes the rôle of monarch of all he surveys. [Illustration: A hermit. It would take an expert turkey hunter to circumvent this bird] By these fights one gobbler establishes his claim as lord of a certain range, which no other gobbler will dispute during the rest of the season. Sometimes, though rarely, I have known an old monarch to take a companion gobbler into the very bosom of his harem, however strange this may appear. I have known of half a dozen instances of this nature where two old gobblers have formed an inseparable alliance and remained together staunch friends for years. Hens are seldom seen in their company and they are extremely difficult to call. I hunted one such brace three years, killing many other gobblers in the long effort to bag these two; never did I call them within gunshot, until one day by some accident they got separated, when it was no trouble to call and kill one of them; the other is, for all I know, alive now. Such fights as I have described break up the social ring of old bachelors, and until the love season is over each male takes up a range to himself, calling to his side as many of the females within hearing of his voice as will come to him. Several gobblers can be heard in the morning gobbling within a radius of a few hundred yards, but each keeps to himself, and by frequent and persistent gobbling and strutting secures the society of such hens as may favor him with their presence. After the disbanding of the old gobblers is the best time in the whole season to bring them to call, as they will come to almost any call, yelp, or cluck; except the mogul himself. His bigotry and vanity render him most indifferent to the seductive coquetry of the females, much less to human imitators. Being assured of, and satisfied with, a well-filled harem, he gives little care to the discordant piping of the hunter, or even the gentle quaver of a hen. In this latitude--from 30 degrees to 33 degrees north--the gobbling season begins about the first week of March, ending the last of May, embracing about three months, though the time depends much on the thermal conditions of the spring. If the weather be dry and pleasant the season will not last as long as if wet and chilly. CHAPTER X GUNS I HAVE USED ON TURKEYS The rifle is, _par excellence_, the arm for hunting the wild turkey under nearly all conditions. It matters little what calibre rifle is used. Years ago when I began to hunt turkeys the muzzle-loading round ball rifle was the only arm thought fit, and it surely did the work well and satisfactorily. It is said that Davy Crockett when a boy was compelled by his father to shoot enough game in the morning to supply his dinner, and was allowed one load of powder and a ball to do it with. If he missed and got no game he got no dinner. In the old days the .38 calibre, shooting a round ball, was about the proper size, with not too much twist in the rifle; one twist or turn in five feet was about the thing. Those rifles were reliable and did not lacerate the flesh unless too much powder was used. Next came the breech-loading rifle with small charge of powder and heavy bullet; like the Winchester model '66 and Frank Wesson's single shot. These guns shot with remarkable correctness at short range, especially the Frank Wesson rifle; but none of them had enough velocity to do as fine shooting as is required in turkey shooting above 75 to 100 yards. With me the .38 calibre Wesson rifle did more certain work on old gobblers than any other rifle I have ever seen or used, nor was the powder charge sufficient to tear the flesh severely, but it would drive the bullet through two old gobblers. The next best gun, and the best all-round shooting gun I ever used on turkeys was a .32-20 Winchester, model '73, but this gun tore the flesh badly. The points to be desired in a turkey rifle are these: A bullet that will kill under ordinary conditions and at the same time leave a minimum trace through the bird; and a flat trajectory for fine shooting at 125 or 150 yards, as that is as far as one will be apt to risk a shot at them. I found that the .32 calibre killed as well as the .50 calibre--I mean the .32-20--if the shot was placed right. It must be remembered that the skin of birds is very thin and delicate; the flesh under it, especially the breast, is extremely tender and juicy, and a rifle bullet passing through it with great velocity will spatter the flesh like soft butter, the bullet having mushroomed against the thick, hard feathers, or even on striking the flesh itself. I believe the best rifle that could be made for turkey shooting would be .30 or .32 calibre, with about 15 grains of powder, and the weight of the bullet reduced as much as possible without injury to accuracy. It would have ample force and not tear the flesh and give even greater penetration than the .32-20. A turkey rifle should not mushroom its bullets, for, although the turkey possesses remarkable vitality, he is easily killed if shot in the right place. As to shotguns, there is little choice so far as the shooting is concerned. Any good modern choke bored gun will answer--the choked being greatly to be preferred, as it concentrates its shot--which is a desirable quality in scoring--on the head or neck, the only mark for a shotgun on a turkey. No. 6 is by all means the size shot for this purpose; one barrel with No. 6 for the head, the other No. 3 or 4 for the body, is the proper thing. Wing shooting turkey is so out of line with my idea of turkey hunting under any conditions that I have little to offer in that respect. To see a big, fine gobbler with his rich bronze plumage all messed up by shot and grime, legs and wings all broken and bloody, dangling about, is a disgusting sight to the true turkey hunter. The turkey is not built or in any way adapted to being so shot, but there are men so nervous and excitable that they cannot still-hunt turkeys. Such men must be going all the time, and their only chance is to scare up the birds and shoot them on the wing. They are not of the stuff that make good turkey hunters, and they will never succeed, no matter how they try. They have no patience to wait on the movement of a turkey when coming to the call, but can sit around a hotel all day spinning yarns, talking politics, and perhaps playing cards all night. This type of man can never become a quiet, contemplative, thoughtful turkey hunter. Unless killed or wing broken, a turkey may receive while on the wing a mortal hurt and yet be lost, for it has such vitality that it will prolong its flight to such a distance as to be lost. At short range turkeys on the wing are easily dropped with a shotgun, but then the whole body is usually filled with shot. Hallock says: "If the hunter be so fortunate as to get within reach of a turkey, let him take deliberate aim at the head if he has a rifle, but the possessor of a shotgun should cover the whole body." To me this seems absurd, for it is the reverse of this that I would suggest to successfully kill the bird. Should the man of average nerve and excitability take aim at the head of a turkey with a rifle he will miss it. I have done it myself under certain conditions, and under ordinary circumstances I would not suggest that any sportsman take such chances. The turkey hunter who uses his rifle gets more real enjoyment out of the sport than with any other arm. He gets more chances to kill the bird, because of the greater killing range of the rifle, and consequently is surer of his game, particularly if he is a marksman with a cool head, steady hand, and good vision. If one desires to be a first-class, all-round turkey hunter, my advice is to employ the rifle, and when a turkey is found, aim for the body, and that part of it that covers the vitals. If you do not do this you are likely to see your game running away as fast as his legs can carry him, for, unless your bullet has passed through his body, striking a vital part, the bird is likely to escape. If circumstances are such that you cannot procure a rifle, or are wedded to a shotgun, I should advise the use of No. 6 shot, and would recommend aiming at the head of the bird, unless they are young birds and quite near enough to make sure your shot. Do not use buckshot if you can procure any other. Should you use No. 5 or 6 shot and aim at the head, you will be surprised to learn at what range you can kill a turkey. Some hunters who use a shotgun prefer No. 6 in one barrel and No. 4 in the other, using one for the head and the other for the body. The reason that I do not recommend the use of buckshot in turkey hunting is because the vital parts of the turkey are very small, and at forty yards the chances of reaching these parts with buckshot are slim. Those who have tried buckshot at this range note that they have knocked their birds over nearly every time, but are surprised to see them get up and run away. This never happens if the sportsman uses a good rifle and places his bullet in the right place. CHAPTER XI LEARNING TURKEY LANGUAGE--WHY DOES THE GOBBLER GOBBLE To learn to imitate the cry of a turkey is no great feat, if you have something to call with and know the sounds you wish to imitate. One can become proficient in the use of the call with reasonable effort; but to expect to call intelligently, without a proper knowledge of the interpretation of the notes produced, is as absurd as to read a foreign language and not know the meaning of the words. Unless you know the meaning of the gobble, the yelp, and cluck, in all their variations, you cannot expect to use the turkey language intelligently. Without such knowledge you will fail to interest the bird you try to call, unless by accident or sheer good luck you brought the cautious thing within sight. It is not desirable, though, that we depend upon luck; one should prefer skill in calling, so that he can at all times depend with a degree of certainty on accomplishing his purpose of fooling the bird. I was once hunting with a friend, and as we sat together by White Rock Creek calling an old gobbler; two or three other hunters, at different points but within hearing, were also calling, keeping the turkey continually gobbling. My friend asked why I did not call oftener, fearing the others would decoy the turkey away from us. I told him that I had already put in my call and the gobbler understood it, and the other fellows were calling by simply making sounds with no apparent meaning or reason, and when the gobbler got ready he would come to us. I then took out my pipe and had a smoke. Meantime the calling by the other hunters was going on at a terrific rate, and the gobbler was apparently tickling their ambition with his constant rattle and strut. Ere long he came directly to us and we shot him. I have known men who could in practice yelp almost as well as the turkey, but when attempting to call the wild bird would do little better than the veriest novice. If such persons' confidence and ability to call did not fail them, their judgment would, and the opportunity would be spoiled by some absurd act. It is not so much what one should do in calling, but what one should not do, as it is better to leave things undone unless done right. This subject requires the most minute and careful knowledge of turkey lore, and will require much of your patience before you are proficient, and I trust you will find in these lines more for your contemplation than you might suspect. The conditions under which you call are daily varied, while the methods to be employed each time are quite complex. In spring the males are gobbling, and the love-call of the hen is then the one to use. In the fall and winter, when the turkeys are in flocks and do not gobble, this not being the love season, you do not then make love-call, but such as suits the occasion and the temper of the game. First, as to gobbling: We will analyze that feature, as it involves great interest to the hunter. As a matter of fact, more people hunt the turkey during the gobbling season than at any other time, and strange to say get fewer turkeys, simply from the fact that the call is not understood. Why do they go in quest of turkeys at that season? For the reason that they are much more easily located, as the gobbling of the turkey indicates its whereabouts, removing the necessity of spending much time in search of them; hence, were it not for the gobbling many hunters would never attempt to hunt the birds, knowing too well it would be useless. The first and most important thing that you should impress on your mind is, that the turkey-cocks gobble for a reason. Why does the gobbler stand in one spot and make a great ado? Every turkey, whether born in Florida or Mexico, does the same, and at the same period of the year, because his gobbling and strutting is to let the hens know where he is, and if he keeps it up every hen in hearing will come to him. The gobble of the male turkey is his love-call. In the early spring, when nature begins to unfold its latent energies and develop its dormant resources for creating new life, the old gobbler feels its impulses, and is not slow in asserting his place as leader of the grand aggregation of noisy choristers that make the deep solitudes of the forests ring to the echo. From some tall pine or cypress he loudly proclaims the approach of dawn. "_Gil-obble-obble-obble, quit, quit cut_," comes the love-call from his excited throat, so suddenly and unexpectedly that all the smaller species within a hundred yards are dazed with fright. I often thought that, if he possessed any faculty of humor, he must be greatly amused at the commotion he creates all by himself. [Illustration: Big woods in Louisiana where the old gobblers roam at will. A delightful place in which to camp] He stands erect on his high perch, peering in all directions to determine the next thing to do, or to ascertain the result of that already done, and it often happens that this is the last and only gobble he will produce that morning, owing to its being accidental. But he will stand upon the limb of his roost quietly looking about, and after preening his plumage for a few moments, and seeing that no enemy lurks near, he stoops, spreading his great curved wings, and silently as a summer's breeze leaves the tree and sails to the earth fifty to seventy-five yards from his perch. He stands perfectly still some moments until satisfied all is well, then he carefully places the tip of one wing on the other across his back once or twice, and walks slowly away to feed. A few mornings later, if the air be crisp, clear, and not too cold, he will gobble lustily many times before he flies down, for the first warm days of spring begin to arouse his animal instincts and he longs for the society of his mates. He is now in the prime of turkeyhood, in his finest feather and flesh. He is fat and plump, hence this is the stage at which the hunter, most of all, prefers to bag him; but he is no easy game to secure just now. If he ever were afraid of his own voice, step, or shadow, it is at this time; but the forest is ringing with a din of bird song, and it is impossible to restrain his impulse to "_gil-obble-obble-obble_." Making one or two quick steps, he raises his head and says "_put-put_," then stands perfectly still, his great hazel eyes scanning every leaf or bird that moves. Why does he gobble? It is the call of nature to break up his loneliness and secure the society of his mates. Turkeys do not mate in pairs, they are polygamous, loving many wives. I wish to direct attention to the common and erroneous belief, even among expert turkey hunters, that it is the call-note of the hen that brings the sexes together. This is incorrect. It is the call of the male. It was after years of study that I discovered this fact, which, once plain to my mind, assured my success as a turkey hunter. I found that the gobbler was doing the same thing I was doing; I was struggling with all my ability and tact to draw him out, while he was playing the same game on me; it was a question of who had the greater patience. If I remained and insisted on his approach, he would yield and come to me. Here is his customary method: At the very break of day, the weather being favorable, he begins to gobble in the tree in which he is roosting. The gobbling is produced at very irregular intervals, sometimes with long, silent spaces between, at others in rapid succession. Some turkeys gobble a great deal more than others. Some will gobble but once or twice before they come down, and gobble no more that day; others will not gobble until they fly down, and then keep it up for hours. Some will gobble all day from sunrise to sunset. All these various idiosyncrasies the knowledge of the hunter must meet. Some will come to the yelp or cluck at the first imitation of the sound, while others will take hours to make up their minds whether to come at all. Take it all together, the gobbler has most obstinate ways, purposely or not; the wily hunter must bring all his faculties to bear if he would outwit him. If the old turkey begins to gobble on the roost at the early dawn and to strut (although all do not strut in the trees), he will gobble, watch, and wait, hoping he may catch sight of the female--located by her responsive yelp or cluck--that may be roosting in a tree near him, or one approaching on foot or flying toward him through the timber. If not so fortunate, he will usually fly to the ground, scan the surroundings with his keen eye a moment or so, then drop his wings, spread his semicircular tail, strut, and gobble. Then he lets his dress slowly down as the spasmodic paroxysm subsides, listens, and looks, gobbles a time or two, listens again, and struts, and so on. If he sees no hen or hears no sound resembling that which he desires, he begins to calmly walk toward his feeding grounds, gobbling at long intervals; he then usually stops for the day. This applies to the first weeks of the gobbling season, and he is quite easily called then, as it is too early for the hen to crave his attentions; but later it all changes. The hens seek his presence as the procreative impulses begin to stir them. The gobbler then will take up a chosen territory in a certain piece of woods, the most favorable to required conditions, and roost in the vicinity nearly every night, that is, in case he has secured a fair harem of six or eight hens; but if he is not so fortunate he will run all about the country, having no special place to spend the night. But now we are contemplating the gobbler who has been so fortunate as to secure a fair-sized harem, and has confined himself to one locality, in which he will peaceably and contentedly remain all the gobbling season. I have heard them gobble late in June when they have one or two hens with them, who evidently have had their nests and eggs destroyed and are again associating with the males. It is usual for the hen to visit the gobbler every morning, staying in his company only for a short time; and when she departs he follows her slowly a few steps, then begins to strut and gobble violently until she is out of sight. He knows his complement of hens, and does not cease to strut and gobble until all hens come to him; he then quits gobbling and strutting and steals away to feed on tender leaves, buds, and grasshoppers. At such times the hunter, by piping seductive quavers, may tickle his vanity and stir anew his passion, when he will stop in his hunt for food and commence to gobble, strut, and gyrate enough to exhaust your patience, but if you call properly and are cool and quiet he will come. The turkey's gobble is easily heard at a distance of from one to two miles if the air is still and clear. These are the rules that apply to turkeys in general, but there are exceptions; for instance, some old gobblers never secure the favor of even one hen during the whole season, but will run and prowl the country over, seeking such stray females as may be met with, even visiting the grangers' domestic flocks, which is not an unfrequent circumstance in settled neighborhoods. These solitary old birds when met with are easy prey to the expert caller. CHAPTER XII ON CALLERS AND CALLING There are in use by all hunters who still-hunt the turkey, instruments used for imitating the call-notes of this bird; a few lines on these useful implements will not be amiss here. The box or trough call, the splinter and slate, the leaf call, all have their merits, and can be made to imitate the different notes of the hens and young gobblers. The leaf call is simply a tender leaf from particular trees, held between the lips, and when well executed, the call with it is good. The box call is said to make excellent imitation of the hen call, but I have yet to see one that satisfied me. The box call is made by taking a piece of wood, preferably poplar, or some other soft wood, about four inches long, two inches deep, by one and a quarter thick. Mortise a square hole in this block, leaving the ends one half inch thick, one side one eighth, the other quite thin. The mortise is one and a half inches deep. A piece of slate some four inches long by half an inch wide is drawn across the thin edge of this box in various positions, and one skilled in the use of this call can obtain very good results. The call most in use by the backwoods turkey hunters in the Southern States, and one that causes the death of more turkeys than all other call devices put together, is simply the hollow wing bone from the second joint of a hen turkey, with both ends cut off to allow free passage of air. One end is held with the lips in such a manner that the inside portion of the lips covers the end of the bone. The breath is then drawn in sharply, and when one is skilled in its use the different call-notes of the hen turkey can be produced perfectly. There are several other devices much after this order, but I have never found use for any of them; in fact their defects prompted me to invent a call of my own, which I prefer. First, get the smaller bone from the wing of a wild hen turkey: the radius of the forearm. Hallock says the larger bone, but he is wrong. The bone should be thoroughly cleansed of all its marrow. After cutting off nearly one half inch from each end of the bone, the ends are made quite smooth with a file, all rough surface removed, and the bone finished with fine sandpaper or emery. The round end of this bone is packed and glued into the end of a piece of reed cane joint two inches long and three-eighths in diameter. Then a nice nickel-plated ferrule or thimble is fitted on the cane to prevent splitting, and the sloping end is wrapped with silk. Next, get another joint of cane that the first piece will just fit into and glue them tightly together; then cut off until the right tone is produced. The flat end of the bone is used as the mouth-piece. The end of the bone that is inserted in the cane is wrapped with tissue paper wet with glue and pushed firmly into the cane three quarters of an inch, and care must be taken to make this call air-tight at the joints; when the glue dries, it will be strong, air-tight, and durable. The bands or ferrules are intended to make the instrument doubly strong, as well as to improve its looks. It is a tedious job to make a good call, but when you have one properly made, it will last a great while, and I think this particular call is the best in the world. [Illustration: JORDAN'S TURKEY CALL] There is one objection to the box, slate, or similar calls: they make quite a noise near by but can not be heard any distance. The instrument I make can be heard a half or three quarters of a mile away. This call is used by taking the flat bone end between the lips and by measured sucking motion the notes are produced. The cluck is produced by placing the tip of the tongue on the end of the mouth-piece, and giving a sudden jerk and suck. This, according to my opinion, is the most natural cluck that was ever made by any instrument, and it can be modulated so as to seduce or alarm at the will of the operator. It is necessary to practise the use of a caller until proficiency is attained, the same as you would do in playing a flute or violin. Calling, in my opinion, is the most important thing to be considered when in quest of the turkey, and the knowledge of how to do it is difficult to impart to others. There are four distinct calls of the wild turkey one should become familiar with to become an expert turkey hunter; these are the call of the young hen, the old hen, the young gobbler, and the gobble of the old male bird. The latter is almost impossible to learn, and I have seen but two or three men in my life who could imitate the gobble. The sound is made with the throat, and I know of no way it can be taught. The notes of the hen turkey consist of a variety of quavering sounds such as are given by the domestic fowl, but which require study and practice, with the best devised caller, to imitate. The plain yelp or "_keow-keow_" are the chief notes to learn, and once mastered and employed in concert with the cluck, will usually be all that is necessary in calling turkey, be it a flock of scattered individuals or an old gobbler (in the gobbling season), but it would avail nothing on the latter at any other time. "_Keow-keow-keow_," or "_keow-kee-kee_," "_cut_," "_cut_"--these are the variety of notes, and each has its meaning, however singular that may appear. The turkey has no song, and the notes it employs are either conversational, call, distress, or alarm notes. Early morning, when they are dropping down from their roost, is the best time to study their language as well as their habits. If you go near a flock of tame turkeys and begin to yelp and cluck, they will reply and keep it up as long as you do, so you can soon learn their language. If the turkeys be wild ones, keep well out of sight, for they will stand no familiarity. I am not, however, a stickler about keeping out of sight when calling. I prefer to sit in front of a tree that is on the side from which the turkey is expected to approach, rather than to get behind it. I sit in front of the tree in such a manner that a turkey with the keenest eye in the world will not identify me, if properly fixed, clothed, and motionless. The explanation of this is that the gobbler is not looking for a person, but for another turkey; and as it can think of but one thing at a time, it sees nothing that does not resemble that which it is in quest of; but if you move, its keen eye will quickly detect you. The turkeys seem to have no special power of smell, so if the hunter's clothes are gray or drab, he may sit at the base of a tree, and by keeping quiet, the turkey will many times come within ten or twenty feet, and, although looking directly at him, will fail to make him out and walk leisurely away. I once had a flock of wild turkeys come very near me, and some of them jumped up and stood on the log I was resting my back against; one hen was within three feet of me, and she stood for a few minutes purring and looking me over, finally leaping off. Then a young gobbler came in front and took a good look at me. He seemed to have a suspicion that I was not a stump, for he walked back a little and stopped to meditate. Not being satisfied with his first investigation, he came up again and took a better look; after satisfying himself he walked leisurely away. He looked so quizzically at me that I could scarcely refrain from laughing. At the same time these inquisitive birds were looking me over, my rifle was trained on an immense gobbler within eighty yards strutting in plain view. Upon him my attention was chiefly fastened, and in a few minutes the old fellow came to bag. A dead grass colored suit is not so good for a turkey hunting suit as one gray or brown. If the game you seek be an old gobbler, and the time spring, you will employ the call fully as much as when calling the scattered brood in fall or winter. I generally use the plain, quaint, easy measured yelp or quaver and cluck of the female; this same call has a hundred variations, but it is not necessary that you employ all of them. The simple "cluck-cluck-cluck" and now and then plain "keow-keow," when properly done, is generally effective. I have called as loud as I could, so as to be heard a mile away, while an old gobbler was standing near enough for me to see the light of his eyes without alarming him. Again I have called very low, just as a test, with the same result. Sometimes the old bird is unusually cautious; then the less calling the better; then, after you have engaged the attention of the turkey so that it will stop and gobble and strut, the less you call him the better, for the reason that in gobbling and strutting it is using all its own persuasive power to draw you to him, thinking you are a hen. Under these conditions so long as you continue to call or reply he will remain and gobble, and insist on your coming to him. But if you have commanded his attention and stop calling and wait, he will make up his mind to come to you, as he has come to the conclusion that the hen is indifferent to his company and is moving away from him; this will excite his anxiety and cause him to make haste toward you. Under such circumstances, and they occur very often, the hunter will very soon note, after he has quit calling, the gobbler will gobble oftener, more furiously, and strut with greater vigor. This is the time when most turkey hunters make a fatal mistake, for if you call after the gobbler starts toward you, he will stop a while at that point, and go through all the maneuvers he has been worrying you with for some time, march back and forth to his recent stand and give you another hour or two of waiting, or perhaps he will go away to return no more. Do not make this mistake, but keep still, wait, and watch. Let the gobbler do the gobbling and strutting, and you do nothing but keep your eye on your rifle sights and watch for his appearance. When he suddenly stops gobbling and strutting look sharp and keep your gun leveled in the direction from which he is expected, but by no means have your gun in such a position that you will have to move it after the turkey is in sight. Some men have a habit of moving their guns about, although they have their heads and bodies hidden and quiet. They might as well get up and say "hello." [Illustration: I soon saw the old gobbler stealing slowly through the brush] If a gobbler stops, and gobbles and struts in one place some time, while you are calling him, this is good evidence that he will come to you, if you have but patience and keep quiet; nine hunters out of ten, however, take the opposite view of it, and for the lack of good understanding of the turkey, and of patience, get up and go home at the very time when success would have crowned their efforts. Now, if a hen has gone to the gobbler, as will often occur, and they are out of your sight in the brush, you will know this to be the case by the long interval between gobbles; if it be fifteen to twenty minutes, you may be certain a hen is with him. You cannot always be sure that a cessation of gobbling is for the purpose of attending the hen or of coming to you, but you will soon find out if you wait, as the turkey is sure to strut and gobble near the place after the caress is over; this has been my experience hundreds of times; in fact it is characteristic and habitual, and it rarely happens otherwise. Here is an instance: Two young men accompanied me once to a creek near the margin of a large prairie in Texas to see me call an old gobbler. At the dawn of day the gobbler broke forth into a lively gobbling, when we proceeded to an old fallen pine log to call him. Having waited for him to fly down from his roost, I began the regulation series of calls, clucks, etc. The turkey was a great gobbler and did his share of it, but he would not come immediately to the call. After a while one of the boys remarked that he heard a hen yelping near the gobbler, and then all gobbling ceased, and the boys remarked he had gone off with the hen. I said, "No, he is there yet." This silence lasted fifteen or twenty minutes, while the mosquitoes were covering the faces of the boys; but they were bent on seeing the play out and would squirm and rub off the pests, then listen and look, as they lay prone on the pine straw and peered over the log. Once in a while I would yelp, but no response came until the gobbler's attention to the hen had ceased; he then began to gobble again as vigorously as though nothing had occurred. Then I began calling again, but he would not come to me, and soon another hen came flying and lighted in a tree near him, and a moment or two after flew down to him. This caused another long wait. When through with the second hen there was another long strutting and then another hen paid him a visit. By this time the boys had become impatient, and were anxious to go home; the mosquitoes were biting them severely and their stomachs were craving nourishment; so was mine, but I knew what I was about, and in a low whisper remarked: "Boys, if you can endure it no longer we will go home, but it is hard to have come this far before daylight, six miles, and have such a fine gobbler within our grasp, then give it up and go home without him." "Oh, well," both said in a whisper, "if you think you will get him, we will stay all day." "That is all I ask," I replied. "On these terms he goes home with us." By this time the gobbler had finished his attention to the third hen and was gobbling furiously in the same spot. I began to call again and the gobbler responded lustily. Having given him a few well-meant calls, I put the caller in my pocket. Seeing this move, one of the boys asked me if I was going to give up. "No," I replied, "it is his turn to parley and he will come now if no other hen comes to him, so you fellows keep still as death, but keep a careful watch." Very soon, after a series of rapid and excited gobbling, all was still. My rifle got into position, and I whispered to the boys to peer over the log, but to keep their heads still, as the gobbler was coming and would soon be in sight. The woods had been burned and the low scrub in our region was black and charred, save small spots that had escaped the fire. I soon saw the white top of the old gobbler's head stealing slowly through the dead brush a hundred yards away, but the boys could not see him until he walked upon a small mound some three feet in height, that brought his whole form above the dead bushes. His feathers were all down, lying close to his body, and his long beard hung low; a noble bird he was. The most thrilling and picturesque object to my eye is the long beard of the turkey; just as the big horns of a buck are to the deer hunter. In a low whisper I asked the boys if they saw him. "Yes, yes," both answered in a trembling whisper. Then the rifle cracked and the bird sprang into the air and fell back dead. The two boys, wild with delight, sprang to their feet and went crashing through the burned underbrush to get hold of the fallen turkey. One of the young men, quite a hunter, remarked: "That beats all the maneuvering with a gobbler I have ever seen and was well worth the long ride to witness." So presenting him with the big twenty-two pound bird, we went home. As soon as possible select a place to call from. To a novice there is no special rule by which one can at all times be governed in calling old gobblers. Each bird is possessed of some peculiarity different from its neighbor, and all individual variations the hunter must meet with good judgment. When out very early in the morning in the vicinity of turkeys, get some elevated position, a ridge if possible, and, as the dawn is breaking, listen for the gobble. The first sounds one is apt to hear are the hooting of the owls; the next, as the light grows apace, is the note of the cardinal, found in all southern woodlands. As a roseate glow begins to replace the gray dawn, one will hear the "_gil-obble-obble-obble_." It may be within one hundred yards of you or perhaps a mile away. You should wait until the turkey gobbles again to be certain of his direction, then make all haste to him, and get as near as you wish before he flies down from his roost. When within one hundred and fifty yards of the gobbler, stop, and be careful lest he sees you, as his ever watchful eyes look everywhere, especially at things on the ground. As soon as possible select a place to call from. To a novice an old treetop or log is best, but to me the front of a tree is preferable, with an open space in front that the gobbler may come into to be shot. But whatever the place selected, get into position as soon as possible, and let it always be an attitude that will not cramp you should you have to remain a long time, and where you can have easy action for your arms and gun. That is why I prefer the side of a tree next to the game. If the gobbler is still gobbling after you have seated yourself, sit quietly until he flies down; that is best. But if you cluck or yelp to him in the tree, let it be but once or twice to attract attention and no more; no matter how much he gobbles, you must keep still until he leaves his roost, and even then wait a few moments for him to gobble or strut, which he is sure to do on reaching the ground, after taking a look around. After this you can give him a cluck or yelp, or several of them, no matter how many, provided they are well delivered. If you are not yet an expert at calling, best make as few calls as possible; for he will surely reply by either gobbling or strutting, or both. Do not be in a hurry, for generally he is in no hurry, but has all day to worry you, and will surely do it if you continue calling after you have said enough. If you desire to get your shot at the gobbler as early as possible, call as little as you can after you have got him interested. If you continue to yelp every time he gobbles, he will stop in one place and gobble anywhere from two to six hours, exhausting all your patience and temper. In selecting a place to call from, there is one caution that should never be forgotten: never get behind a tree so that you will have to look from one side to point the gun; the turkey is sure to see you and run away before you can shoot. CHAPTER XIII CALLING UP THE LOVELORN GOBBLER There is a wide difference between the old gobbler and the young gobbler, and the tactics to be employed in hunting them are quite different. At two years old he can be distinguished by his beard, which is then about five inches in length, the tip having a burned appearance; his spurs are about five eighths of an inch long, are not pointed, while the average weight of the bird is about sixteen to eighteen pounds. At three years this burned appearance disappears and the beard is seven or eight inches long, straight, black, and glossy, the spurs being an inch or more and pointed. The bird may now be considered full grown, and weighs from nineteen to twenty-two pounds. Henceforth there is no way I know of to tell his age. He continues to grow for several years, taking on fat as he gets older, while the beard will attain to a length of twelve to thirteen inches, when it wears off at the tip on account of dragging on the ground while the bird feeds. But the beard does not indicate the size of the turkey, as some very small gobblers have extremely long ones. The largest turkey I ever saw had an eight-inch beard and weighed twenty-four pounds even though quite lean; he would have weighed thirty-one or thirty-three pounds if he had been fat, and he may have been twenty years old, for he was known to have inhabited one locality for more than fifteen years. You must first ascertain where the gobblers are to be found, and then be on the ground before there is the least sign of daybreak to select a place where you can sit hidden and in comfort. If satisfied that gobblers are in the vicinity, wait until dawn approaches, and if then you do not hear them, hoot like the barred owl. If there is an old gobbler within hearing, nine times out of ten he will gobble when the owl hoots; but if you get no response, "owl" again, or give a low cluck; the old gobbler may be on his roost within sight of you. If still no response, cluck louder, and repeat at intervals, adding a few short, spirited yelps; if you fail, move quickly a half or quarter mile away and call loudly with a cluck and yelp or two. Proceed in this manner until you have traversed the range of your proposed hunt. In this way I have encountered several old gobblers in a morning's tramp, while there was not one within hearing of the point first selected. If turkeys have begun gobbling at dawn, you must choose a place to call from. My choice is in front of a tree a little larger than one's body, facing the turkey. If possible have your back to a thicket with open ground in front, or you may prefer to get behind a log or stump, or in a fallen treetop. Do not make a blind, for the obstruction will hide the game which is as apt to approach from one direction as another; generally the unexpected way. If you sit out in an open place by a tree, and stick up two or three short bushes in front, he will never see you until near enough for you to shoot. If the old gobbler is in the tree before you take your position, do not approach nearer than one hundred to one hundred and fifty yards of him; he may possibly see you or he may fly behind you, or alight at your side when you call, and run away before you can shoot. This may look like a small matter to consider, but you will find it amounts to much in dealing with old gobblers, as I have learned from experience. I have had them fly right over my head, so close that I could have touched them with my gun barrel, or alight at my side and run away in a twinkling. One flew so near my brother once as to flip his hat brim with its wing. The most remarkable instance I ever knew occurred to a Mr. Daughty in Alabama. He was calling a turkey that was gobbling in a tall pine, and finding the call would not bring him down, Mr. Daughty took off his old brown felt hat and gave it a flop or two over his knees. Before he had time to think the gobbler was upon him, and he had to drop his gun and ward it off with his hands. He told me the gobbler had stretched out his feet to alight on his head and frightened him so he never thought of his gun, and was so dazed that the gobbler was gone before he recovered his wits. I once called one down, and as he stretched his legs to alight, he saw me, and with a loud "_put-put_," checked his flight and shot up like a rocket. A gobbler will invariably alight within fifty to seventy-five yards of the roosting tree, according to the height they are perched from the ground; therefore one hundred and fifty yards is sufficiently near if your purpose is to call; but if you intend to stalk and shoot him in the tree, you will do best if you show no part of your body; and especially keep the gun barrel out of sight. Many hunters will hide themselves but expose their gun, which is a great mistake, as the bird will surely see the glint of light on the barrel. It is best, in my opinion, not to call while the gobblers are in the trees, for the reason that the gobbler is expecting the hen to come to him; and it will often happen that as long as you call, so long will he remain in the tree and gobble and strut. I have had gobblers sit on their roost until 9 o'clock and gobble because I kept yelping. [Illustration: "Cluck," "put," "put," there stands a gobbler, within twenty paces to the left; he has approached from the rear] Having got into position, wait until your nerves are cool. The turkey hunter must have time. Give a low, soothing cluck, then listen carefully, as the turkey may gobble the instant he hears the cluck; perhaps two may answer, but we will confine our attention to one. If a two-year-old bird, he will gobble before he thinks; but we will not allow you such an easy job as a two-year-old. Suppose the gobbler is three years or over--he will straighten up his long neck and listen some moments. He is not sure it was a genuine cluck, but he thinks it was, and duly drops his broad wings, partly spreads his tail, and listens; then, "_Vut-v-r-r-o-o-o-m-m-i_" comes the booming strut, and "_Gil-obble-obble-obble_," if he dares this it is to elicit a call or cluck from you to make sure he is not deceived. Now call, "_Cluck, cluck, keow, keow, keow_," at once he answers "_Gil-obble-obble-obble_" two or three times in a breath so loud and shrill that it rings out like thunder in the quiet of the forest. Now give a low quaver, "_Keow, keow, keow_," just audible to him, yet low, then stop right there. He will yell out in a fierce and prolonged rattle that will make the squirrels quit their feeding and spring to the trunk of the tree, and arouse the herons from the margin of the rivers and swamp ponds. Then comes the heavy booming strut, and if he gobbles again, be quiet and let him talk to his heart's content. Unless you yelp or cluck at this time, he becomes more and more nervous and restless, and even dances on the limb. Keep quiet; he will now give a few lusty gobbles, and then there is a short pause. Look out now. There is a rustle in the tree, a flip, flip, and you see his big dark form leave the tree and sail to the ground, giving his broad wings a flop or two to ease up the impetus, and as he strikes the earth a cloud of leaves arise in a circle to settle around him. The royal bird straightens up his matchless form, and while his fine hazel eyes scan the surroundings, you gaze with admiration at his symmetry and beauty. More likely than not he has alighted to one side; if so, beware! Probably, too, if the woods are not very open, you will not see him on the ground and must judge as to his movements. If there be but one gobbler, wait a few minutes after he is down, as he is listening and watching; then make a few yelps softly, but rapidly, and a cluck or two. He will gobble and strut vehemently. Be sure your cluck is a perfect assembly cluck, or he may take it as an alarm "_put_." Your cluck, if made at all, should have a reassuring accent, or better not attempt it, depending on the yelp or quaver. The cluck and "_put_" are so nearly similar in sound to the ear that they are difficult to distinguish; but one is a call note and the other is an alarm, hence it were better to omit both rather than disturb the confidence of the bird you are calling. While the two notes are impossible to describe in words, they can readily be produced by an expert caller with a good instrument. Give the gobbler two or three quick little yelps, "_Keow, keow, kee, kee_," in a kind of an interrogatory tone; this is sure to make him gobble and strut, or probably to strut only. I prefer that he strut, although the gobble is more exhilarating to one's ear, but does not signify as much. The strut is the better sign every time; it shows he has leisure and passion. Your "_Cluck, keow, ku-ku_," brings forth at once "_Gil-obble-obble-obble. Cluck-v-r r-o-o-o-mi._" Hush, hear that? "_Cut-o-r-r-r_," "_Cut, cut keow, keow, keow_." What is it? Is some one else calling? No; the sound is too perfect. Hark! how he gobbles and struts with renewed vigor, for it is the siren note of the real hen who has gone to him. You might as well now keep quiet for fifteen or twenty minutes, for he will not answer as long as he is with a hen. As soon as she is out of sight, however, he will listen to you. Here, reader, is the most important lesson to be learned and the most valuable in all turkey lore--patience. [Illustration: Suddenly there was a "Gil-obble-obble-obble," so near it made me jump, and there within twenty paces of me was the gobbler] Fifteen minutes is usually ample time with the lusty turkey. You keep up the call and tease at proper intervals until sufficient zeal is restored, which can be determined by the vigor of his gobble; then do not call any more, no matter what he does. Keep still and watch his manoeuvres, and presently he will begin to gobble and strut with great stress, gyrate, and swerve from side to side, right to left, his big tail, doing everything to fetch the new hen whose voice he hears; but you must not break the spell by any false move. All at once he stops and everything is still again. Maybe another hen has come to his court, maybe not. But do not yelp or cluck; he may be coming to you, for he knows precisely where you are, and if he is not caressing another hen he is surely approaching you. This may take fully an hour, sometimes six. "_Cluck, put, put_," there stands a young gobbler within twenty paces to the left: he has approached from the rear. Make no motion. He has not identified you. "_Put, put._" Keep still. "_Put, o-r-r-r-r._" He begins to step high, turning to one side, then to the other. "_C-r-r-r-r._" He pulls out the tip of one wing and places it on the other. Note that. He is going to walk away. "_Put, c-r-r-r-r._" He is gone; but let him go, and good riddance, for he has created a distrust in the old gobbler's mind that will take some time to remove. You are now compelled to change your place and call again. "_Gil-obble-obble-obble._" Gracious! he is off to the right and fifty yards nearer. If there is sufficient cover, make a detour of from one hundred and fifty to two hundred yards and get ahead of him; then sit down, give a yelp or two, and end with a cluck. That will reassure him at once, and he will most surely gobble in reply; if so, you sit still. Have your rifle in readiness so that no move be made when he comes into view. Very likely you have waited some time since he gobbled last, and apparently he has quit all strutting. There is another ominous pause, but you are ready for him and on the sharp lookout. You are sorely vexed, but your good judgment keeps you alert while the other hunters have long since gone home. "_Gil-obble-obble-obble._" Sh-e-e-e-e. There he is within thirty paces to the right at a half strut. What a bird! See his noble bearing, the bronzed coat, the glint in the keen eye. You can't move now, for he sees you, but he has not made you out. Be still and let him pass behind that big oak, then turn quickly before he comes into view again. Ah! that low green bush has obscured him; he has passed out of sight and does not reappear. Your nerves begin to run like the wheels of a clock with the balance off. Your disappointment is inconsolable. "_Gil-obble-obble-obble_," nearly one hundred yards on his way. This is discouraging, but the educated turkey hunter never gives up so long as a gobbler will argue with him. Get up at once and make a rapid detour, taking in two hundred yards; get ahead of him again and on his line of march. Then sit down and call as soon as possible to attract his attention. This done your chances are as good as ever. "_Gil-obble-obble-obble._" You have estimated well. The gobbler is one hundred yards back yet, which gives you a breathing spell. He begins to rehearse the old rôle of gobbling and strutting, but with greater force, as he has had a long rest. Now give another call and cluck to see where he is; no response, and you are becoming as restless as a raccoon robbing a yellow-jacket's nest, and crazy for just one more call; but I advise not; have patience, and wait. Another call would only cause delay if not other harm. He is the one now to get nervous, for that hen may escape. A crow gives a sudden caw in a neighboring tree, and, "_Gil-obble-obble-obble_," says the turkey, now only seventy-five yards away. But you are silent. Again comes a long pause, and you think he has detected you and gone. A red tail hawk darts screaming through the timber, and, "_Gil-obble-obble-obble cluck v-r-r-r-o-o-m-i_," goes your bird thirty yards nearer; then all is silent again. He has made a strenuous effort to draw your call, but you are deaf. Another long pause and you are in a tremor all over. He has quit making any noise, and the stillness is painful for, save a solitary red bird trilling his carol in yon elm, and a gray squirrel nibbling the buds on that slender maple, all is still. Two chameleons are racing on the log behind which you are crouching, and, springing suddenly to the dry leaves, they startle you with the clattering they make, so highly strung are your nerves; but you dare not move. Why this insufferable silence? The gobbler is coming, but when will he appear? Your rifle is in position, cocked, your eye running along the glistening barrel, but that is all of you which is allowed to move. A distant dead tree falls with a heavy thud that shakes the earth. "_Gil-obble-obble-obble_," breaks upon your ear and sends a thrill through your nerves, and the timid squirrel wiggling and scampering to his hole in a hollow gum. The sound comes from the oblique left. Your eyes turn slowly that way. Ah! there he stands, half erect, half concealed in the brush. You see the white top of his head, the crimson wattles of his arched neck, the long beard and the glint of his eye, for he is only forty paces away; but do not fire, as the least twig may deflect the ball. He has not made you out, although in plain view, nor will he, unless you make a sudden move. You have carefully brought the rifle to bear on him. He is meditative and somewhat listless; but note that tail going up: he is going to strut, and that will bring him into an open space. "_Cluck v-r-r-r-o-o-o-m-i._" There! he is broadside on. See that crease that runs along his neck ending near the butt of the wing? Drop your bead on the butt of the wing opposite where that crease ends. That will kill him every time, as behind lies his heart; while if you aim for the centre of the body the bullet will go through the viscera, making a mess of it, and while a fatal wound, he may get away and be lost to you, for it will not always knock him down. If he stands quartering, aim at the centre of the breast next to you. It will at once be fatal. If the back is presented, which is not once in a hundred times, draw upon the centre of it. Unless turkeys are very plentiful, and you care little about losing a good chance, don't shoot at his head with a rifle. CHAPTER XIV THE INDIFFERENT YOUNG GOBBLER Of all stages, conditions, and peculiarities of these fowls, the young gobbler is the most difficult to understand. He is absolutely unique, hence you must employ entirely different tactics when you go in quest of him. He has little education, but he possesses a great native shrewdness, and I have sometimes thought him more difficult to get than either the old gobbler or hen; this may be a fool's luck, or it may be the result of stupidity or reticence, but I have killed ten old gobblers to one young one. As I have before stated, while the young males are with their mothers and sisters in the flock there is little difficulty in bringing them to the call after the flock is scattered. But after the separation of the sexes they are extremely hard to call, for the reason that they have abandoned the society of the females altogether, and do not pay any attention to their voices. Lack of information and a reckless carelessness have caused the loss of many young gobblers that otherwise might have been secured. After the young males have been separated some time from the females, and are banded together, they are hard to find and hard to bag when found. Instead of flushing at once into the tree at the approach of an enemy, they usually take to their legs and run some distance before stopping, making their pursuit difficult and unreliable. If once flushed and scattered, and the hunter understands how to call them, he can usually get one or two out of the flock if he is familiar with their peculiar ways. Thus after December we have three distinct classes of turkey society, the old gobblers, the young gobblers, and the hens; and no matter what the number of them is, they persistently maintain this separation the rest of the winter. The soft, gentle quaver of the hen has no effect on the ear of the young gobbler at this season, and he will hearken to no other note or call than that of the young gobbler. Even were a flock of hens to pass beneath the tree on which he is perched, he would regard them with no more interest than he would a flock of crows; hence neither the hen nor her yelp would be a decoy to him, but the call of another young gobbler will enlist his attention. The call of the young gobbler, like that of the average boy as he is developing into manhood, is changeable and erratic; at times it is ridiculous from its awkwardness, and hard to imitate or even to identify. It consists of an irregular hoarse and discordant croak and a coarse muffled cluck that sounds like an acorn falling into a pool of water, or the gentle tap of a stick on a log. If this yelp or cluck is properly and timely made, it will bring the young gobbler to the hunter, but usually he is in no haste to come even then. They have ample time to spare for all their movements, and it requires the greatest patience and dogged determination of which a sportsman is capable to sit and wait their pleasure; but if the hunter has a band of young gobblers well scattered, if he has a good caller and is expert in its use, and will make up his mind to sit quiet and talk turkey, he will usually be rewarded. He should use only one or two low, coarse clucks, well measured and some time apart; then the low, muffled "_Croc, croc_." The young gobbler may be sitting on the limb of a tall cypress, hidden from view by a festoon of Spanish moss; or, if in a pine, hidden by the limbs, as still as a part of the tree. "_Croc, croc_," and one low, hoarse cluck, as if a nut had struck the bark of a dead log in falling, are the only sounds you dare to make. He is not so reckless in regard to the call or answers as the hens, and not so nervous. While he sits and contemplates, he measures notes; so that you have to be careful if you would fool him. Now call, "_Croc, croc_." His fears begin to dissipate, and running his beak through his feathers, he makes his toilet. This over, he slowly raises his long neck and head and replies, "_Croc, croc_." "_Cong, cong, croc, croc, cluck._" He turns his head with one side earthward, and gives himself a convulsive shake--"_Croc, croc_." He lifts up one foot and then slowly puts it down; lifts one wing, placing its tip on top of the other, then slips that one out and laps it on the first. "_Croc, croc, kee, kee._" He looks around again to be reassured. Now there is a rustle in the top of the tree, and you see the leaves move, for he has turned on the limb and you may see a portion of his body. You dare not shoot or risk a bullet through that brush. Wait. "_Croc, croc_"; he walks along the limb a few feet, but you still get only glimpses. "_Croc, croc_," and down he sails to the earth. A cloud of dry leaves arises around him and settles again as he closes his broad wings and straightens up. Now is your chance; bag him. [Illustration: The soft, gentle quaver of the hen has no effect on the ear of the young gobbler] When the young gobbler once makes up his mind to go to your call, there is little or no stopping on his part. He walks boldly along, as if he had no fear of anything. But be careful; he will see you surely if you make an unnecessary motion, and there is no compromising a mistake with him. His adieu is final. He is a bird of the fewest words at any time, and stands upon the idea that absolute silence is safety. His habits are exclusive and retiring, seldom showing himself in openings, although at times he is fond of open pastures or prairies where he can see all around him. CHAPTER XV HUNTING TURKEY WITH A DOG I do not believe there is any safer way of bringing a turkey to bag than by the judicious employment of a good turkey dog, and by that I mean a dog trained especially to hunt turkeys. The hunter, too, who employs a dog must know and act his part well to be successful. Of all times to hunt the wild turkey with a dog, the autumn and winter months are the best. The dog should be a natural bird dog, either pointer or setter. My choice, next to the pointers or setters, are the terriers, either Scotch or fox. The Scotch terrier makes an excellent turkey dog, due to its intelligence, patience, courage, and snap. I have had dogs lie by my side when turkeys were gobbling and strutting within a few feet, and never move a muscle until the gun was fired, when they would be upon the bird instantly. If you employ a dog in gobbling time, he must be thoroughly educated to distinctly know his part, which is to keep at heel or lie at your side and watch without a sound until the bird is called to gun and shot; then the dog is allowed to go and seize the quarry if it is not killed by the shot and making off with a broken wing. In Alabama I once saw a large gobbler coming slowly to my call over a pine hill about ninety yards away. I fired at him with my rifle as he was moving in a full strut. At the shot, my gobbler tumbled over, but quickly got up and made off at a lively run with one wing hanging. I started after him, at the same time calling to my brother (who was below me on a creek, calling another turkey) to let go his dog. In a moment I saw a gray streak shoot out from the thicket on the creek, and start up the hill in pursuit of the running gobbler. It was my brother's Scotch terrier, and within one hundred and fifty yards the dog overhauled the gobbler, to my great satisfaction, and held him until I arrived. Had I not had the services of a dog at this time the turkey would have escaped, as he could get up the high, rocky slope faster than I. It is best to take a young dog six or eight months old. The training is easy enough, provided the preceptor knows his part. Like educating a dog for quail, he must get the rudiments before he ever sees the live game, for once a lesson is spoiled a dog is also spoiled. Give him a few lessons before taking him into the woods to hunt turkeys. He must know the turkey is his quest ere he is let loose; and do not loose him until you have found unmistakably fresh signs; for one mistake at such a time will take months to repair. Teach him to lie down, the same as in quail lessons, no matter if he is a pointer, terrier, or hound. Having taught him to lie down, take him walking where there are trees, logs, and fences, and every now and then suddenly sit or squat down by some tree or fence, calling him quickly to you by soft words and motion of the hand. Make him lie down close to your hip, better the left side if you are right handed, so that by any unexpected move he may not destroy your aim at a critical moment. Teach him to lie on his belly or with his head prone between his forepaws. This is easily done, and will insure a motionless attitude as a turkey is approaching. If he whines under excitement, as some will, tap him lightly with a small switch on the head; this will also make him put his head down, and he will soon understand the meaning of it. Next get a dead wild turkey, hen if possible, as it is lighter. Take the dog into the yard or field where there are no dogs or children to bother him. Let him play with the turkey a little, while you encourage him, then have some one drag the turkey from him by the head a short distance, while you hold and encourage the dog to go. Let the turkey be hung up in a tree or bush out of his reach; then let him go and take the trail and tree the bird, and encourage him to bark and jump against the tree. Then have it fixed so that after he has jumped and barked a while you can fire a gun or pistol and the carcass falls to the ground and he pounces upon it. Repeat this as often as you have an opportunity. You may keep a wing cut off at the second joint, using that for several lessons before it becomes tainted, but by no means allow him to tear the wing or bite the flesh of the turkey. You might set him after a tame turkey now and then, but this might bring him some day to grief by a load of shot from your good neighbor. Take the dog with you on a few hunts in the woods for turkeys. If you find a flock, put him after them at once and let him flush them, which he will hardly fail to do. Then, if you can kill one over him, your turkey dog is well-nigh made. Having had your turkeys flushed, you can walk slowly and cautiously in the direction they flew, looking into every tree, and you will soon see one or two of them perched upon a limb. To get your bird now is easy if you have a good rifle; and you had better not be out if you haven't one, as no kind of shooting requires better marksmanship than turkey shooting, especially in the timber. Having treed your turkey, you may get several shots, and meantime the dog is allowed to trot around and bark as he sees fit, as the more noise he makes the more is the attention of the birds diverted from you to him; but after you have looked among the trees in a few hundred yards of the flush, if you have not secured your bird, select a good place to call. Sit down with your back against a tree, or behind a log or fallen tree if that suits you better. Sit quite flat and low, bringing the knees nearly up to the eyes. Call the dog to you at once by a whisper and wave of the hand, and make him lie snugly at your side, looking in the direction you look. After a few minutes, when everything is still, you begin to call at short intervals. Now and then a low yelp, at first, and if you get a reply, cease calling until the results begin to show up, either by one or more turkeys coming to your call, or in their collecting together in another direction, which is more likely to be the case, from the fact that the mother hen is doing more effective calling than you, or they are inclined to go that way anyhow. In such a case you must get up at once and proceed in the direction you see them flying. Go quickly to where they are collecting. Put the dog after them again and into the trees they will go; you then proceed as at first and continue these tactics until you have got what you want, or have lost them entirely. This is excellent and exciting sport, and the dog loves it and soon becomes an expert in the chase. But of all methods of hunting the turkey it is the most disastrous, next to baiting, not so much in the number of birds killed, but the turkey has a great dread of a dog, and if too frequently chased by one it will drive the birds out of the locality. It should seldom be practised in the same locality or upon the same flock of turkeys more than once in a season. The rifle is preëminently the gun to employ in this method of hunting, and there is a great satisfaction in taking a fine bird from its lofty perch in a tall pine, gum, or cypress at one hundred to one hundred and fifty yards, where it would be safe from any shotgun. Dogs trained to hunt turkeys must not be allowed to run squirrels, hares, deer, or any woodland game. It makes no difference as to quail or prairie game, but in the timber his work belongs to the turkey alone. In teaching the young dog to grasp a turkey, it should be trained to seize the bird by the neck every time, and not touch the body, as his teeth will lacerate the tender skin and tear the flesh--a thing no true sportsman would tolerate. It is easy to teach the dog not to mouth the game by making him take the neck in his mouth every time an opportunity is afforded. If he takes hold of the body, or mouths the feathers, make him let go and take the neck. He will soon learn this. The common fox hound also makes a good turkey dog, and takes naturally to it, but he is too noisy. A turkey dog must not yelp or bark on the track before he sees the birds as the hound does. Turkeys are alarmed easily and prefer to run instead of to fly, and if the dog barks on the trail they will run for miles, all the time probably not one hundred yards in advance of the dog. So the dog for turkeys must keep silent until in sight of them, and then bark savagely until they are all flushed. This the pointer, setter, or terrier will do. Be sure to encourage your dog to bark at the turkeys in the trees. Audubon says: "In the spring when the males are much emaciated by their attention to the hens, it sometimes happens that, in plain, open ground they may be overtaken by a swift dog, in which case they squat and allow themselves to be seized, either by the dog or the hunter, who has followed on a good horse." I have heard of such occurrences, but I never saw an instance of the kind. Good dogs scent the turkeys when in large flocks at a great distance; I may venture to say half a mile away, if the wind is right. Should the dog be well trained to the sport, he will set off at full speed on getting the scent and in silence until he sees the birds, when he instantly barks, and, running among them, forces the whole flock to take to the trees in different directions. This is of great advantage to the hunter, for, should all the turkeys go one way, they would soon leave the perches and run again; but when they are separated by the dog, a person accustomed to the sport finds the birds easily and shoots them at pleasure. No turkey is going to run very long ahead of a dog, if the dog is in sight and chasing him. A pack of mouthy beagles, or an old, slow deer-hound, giving mouth continually, might keep a turkey in a trot until fatigued; it is possible then that a quick, swift dog like the Scotch terrier or the pointer might rush on and catch him. But the first impulse of the turkey, on the near approach of an enemy, is to fly and not to depend on its legs; though on seeing an enemy at some distance, turkeys will run away and not fly at all. In the open prairie it is quite another matter. On seeing a turkey or flock of them on a wide prairie, one can, by riding in a circuitous direction, as if passing in ignorance of them, get near and start them into a trot, and keep them trotting by keeping between them and the nearest timber. In this way, although you ride slowly, you will soon run them down. The first indication of exhaustion to be noted will be the dropping of their wings, and when the hunter sees that, he knows that they cannot rise to fly; he then closes in and easily rides the birds down. This is, or used to be, a favorite sport with the cowboys of Texas, in which they sometimes employed a lariat, catching the birds as they would a calf, or shooting them with a revolver. In case neither the revolver nor lariat is handy, they take a bullet, partly split with a knife, and then let the tip of their cow whiplash into the cleft of the bullet; clamping the lead tightly on the lash. Thus armed, they pursue the turkeys until they drop their wings, when, dashing among them, they strike the neck of the turkey with the lash, a foot from the end of the tip, which sends the bullet whizzing around the neck four to six times; and ere the turkey can recover, the cowboy dismounts and secures it. If there is snow on the ground there is little trouble in following the turkeys by their tracks. I have done but little of such hunting, as sufficient snow seldom falls in the South to make good tracking. When you hunt turkeys on the snow, all there is to do is to find their tracks and follow them carefully until the birds are seen; then observe the same tactics as in stalking them on the bare earth. In the South they are unprepared for much cold, and at such times will likely be found grouped together on the sunny slopes of hills, or behind some log or fence, to avoid the bitter winds, especially if the sun is not shining. They will then often remain on their roosts half a day rather than alight on the cold snow. If you attempt to stalk an old gobbler when he is gobbling it is quite easy if you learn the course he is taking and get ahead of him and simply wait. Some men hunt no other way and are successful; but it requires the greatest care, and a thorough knowledge of the woods you are in, so that you may take advantage of ridges, ravines, gulches, thickets, etc. When you have discovered a flock of turkeys at some distance from you, stop and wait a few moments. If they are feeding, and you are unobserved by them, carefully note in what direction they are moving. It is hard to tell if they are going or coming two hundred yards away, but there is one way by which their movements can readily be determined and that is by their color. If they are approaching, you will notice the blackness of their breasts; or rather the birds will appear almost black; and if a majority so appear, you may be sure they are coming; in other words, if you see one or two of them straighten up, and they look quite dark or black, you can then be certain of their approach. On the other hand, if you notice that they look a lightish gray or brown color, they are going the other way. But do not be deceived, as sometimes a flock has stopped to feed, and they will be turning and facing in all directions while so engaged; occasionally one will straighten up, flop his wings, and look back. Have an eye to the band and you will see if many of them look black or gray. If there are gobblers in the bunch, note their breasts which are blacker than the hens. There is another way to find the direction in which the turkeys are moving if you cannot see them. When you have found fresh signs in the woods, note the scratches carefully to see which way most of them incline. This is easily determined by the direction in which the leaves are thrown by the birds' feet. Sometimes, if the scratches are made late in the evening, they will look fresh the next morning and thus deceive the oldest hunter. I once saw scratches on an open pin oak and cane ridge; then others at twenty paces, and again at fifty paces still others. After a careful examination of the scratches, I concluded there must be two old gobblers that had made the signs; and, although I knew of twenty or thirty hens and some young gobblers on that ridge, I had no suspicion before that there were any old gobblers. Now, reader, what caused me to suspect from these scratchings that old gobblers were about, and that there were two of them was this: there were but few scratches and at long intervals. The scratches were very large, almost two feet across, while the leaves had been thrown five or six feet back, indicating long legs and large feet with a great stroke. I noticed there were two separate lines of scratches some ten feet apart on the main trend; also the scratches were twenty to fifty yards apart in the direction the birds were going, which indicated that the two birds were walking along at a brisk pace and keeping pretty well in a straight line, feeding as they went. I believe no man alive or dead has killed more "old gobblers" than I have, and yet the heaviest I ever bagged weighed twenty-four pounds gross. This bird might have reached thirty or thirty-three pounds had he been fat, but it was late in the gobbling season, when the winter fat is run off by constant love affairs, leaving them greatly reduced in weight. This specimen was killed in Trinity County, Texas, where I have found the turkeys to average heavier than anywhere else I have hunted. Audubon said the wild turkey would soon become extinct in the United States, sixty or seventy years ago; but to date his prophecy has failed in so far as the Southern or Gulf States are concerned. Although here as elsewhere hunted and persecuted without consideration, they are remarkably plentiful still. There are localities in the Gulf States that will not be cleared up or utilized for agricultural purposes in ages to come--if then. The immense swamps--annually overflowed--great hummocks, and the broken, untenable pine hills, will afford suitable retreats for the turkey for generations to come. Wild turkeys are less understood by the average sportsman or even naturalist than any other of our game birds. It is common to read of the acute olfactory powers of the turkey; that he scents the hunter at one hundred to three hundred yards; the truth is it must be a pungent odor to have a turkey detect it at ten paces. CHAPTER XVI THE SECRET OF COOKING THE TURKEY Of matters with which the average sportsman has to do, there is none so little understood as that of cooking game, and especially the turkey. Thousands of sportsmen go into the hunting camp expecting to play the rôle of cook without the knowledge of the simplest requirements and as a consequence are in perpetual trouble and disappointment on account of the blunders that are the inevitable results of lack of information. In the solitude of the forest the hunter should not be at loss for methods of cooking even if he has but a frying-pan; a log for a table; his plate, a section of bark or large leaf. The turkey is supposed to be a bird of dry meat, but this is so only when all juices are boiled or baked out of it. The usual manner in which turkeys are cooked is by roasting or baking. If the turkey is an old one, the first process is to parboil until the flesh is tender; then it is stuffed with sundry things, such as bread-crumbs, oysters, shrimp, shallots, onions, garlic, truffles, red and black pepper, wine and celery to destroy the natural flavor of the bird. It is a mistake to disguise the rich, delicate flavor of turkey meat with the odor of fish, but it is done and called roast turkey. If the turkey is a young one, cook it in the way usual to stove-baking, after first filling its cavity with a suitable dressing of bread-crumbs, pepper, salt, and onions chopped fine, moistened with fresh country butter. This is the best dressing that can be made, and will detract nothing from the flavor of the bird nor add to it. If an old turkey, parboil it until the flesh is quite tender, then stuff and bake. In the forest camp I neither bake nor roast the turkey. Imagine a gobbler dressed and lying on a log or piece of bark beside you. Take a sharp knife, run the blade down alongside the keel bone, removing the flesh from one end of that bone to the other. By this process each half breast can be taken off in two pieces. Lay this slab of white meat skin side down, then begin at the thick end and cut off steaks, transversely, one half inch thick, until all the slab is cut. Now sprinkle with salt and pepper and pile the steaks up together; thus the salt will quickly penetrate. Do not salt any more than you want for one meal; the meat would be ruined if allowed to stand over for the next meal before cooking. Just as soon as the salt dissolves and the juice begins to flow, spread out the steaks in a pan, sprinkle dry flour lightly on both sides evenly, taking care to do this right, or you will get the flour on too thick. Give the pan a shake and the flour will adjust itself. This flour at once mixes with the juices of the meat, forming a crust around the steak, like batter. Have the frying-pan on the fire with plenty of grease, and sizzling hot so the steak will fry the moment it touches the hot grease. Put the steaks in until the bottom of the pan is covered, but never have one steak lap another. If the grease is quite hot the steak will soon brown, and when brown on one side, turn, and the moment it is brown on both sides take out of the pan. By this method you retain almost every particle of the juice of the meat, and at the same time it is brown and crisp, and will nearly melt in the mouth. The flour around the steak does not only prevent the escape of the juice, but also prevents any grease penetrating the meat. If you like gravy, have the frying-pan hot and about a teaspoonful of the grease in which the meat was fried left in it; take a half pint of cold water and pour into the pan. Let this boil about five minutes, when you will have a rich, brown gravy, which season with salt and pepper and pour hot over the steak. You don't want a thing else to eat except some good bread and a cup of creole coffee. Having eaten turkey thus cooked you would not care for baked or roast turkey again. The bony portions of your turkey may be cut up at the joints, and all available put into a pot or saucepan having a lid, with a few slices of pork or bacon for seasoning, or fresh butter. No matter how fat any game is a little pork improves it. Put in a pod or two of red pepper and add a little water; let this boil and simmer until quite done. I am giving directions now for making a stew. For the thickening, take an onion or two and cut into small pieces, a pod of red pepper broken up, a tablespoonful of flour sifted, and some salt. Put all into a pan and pour in a cup of cold water, stir until the lumps of the flour disappear, then put the mixture into the pot with the turkey. Stir occasionally until it boils, and if there is not sufficient gravy in the vessel where the stew is cooking, add more water. Boil thirty minutes, then serve. In this stew you get the finest and most wholesome dish imaginable, and at very little expense and trouble. There are many who can prepare food but never understand the reasons for doing things. Not one in a hundred knows why meal, flour, or cracker-crumbs are put on fish or meat while frying. They tell you it helps to brown the flesh; it does no such thing, but prevents browning while the meat is being cooked. Leave off the flour or meal, and by the time the meat is cooked it will be dry and hard as pine bark and as indigestible. When fish is rolled in flour or meal, the fish is not browned, but the covering is. CHAPTER XVII CAMERA HUNTING FOR TURKEYS During the past ten years, while the season was open on wild turkeys, I have made a rule to leave the gun at home and hunt the turkey with the "camera" instead. On countless occasions I have sat on the bank of a beautiful creek in Alabama watching and waiting for these noble birds to appear and pose. Time and patience, that's what it takes; likewise to know the ways of the bird. On one occasion I had found their great tracks on the sandbank, and, noting it as a favorite crossing, made an impromptu blind to mask the camera lest the birds get the least glimpse of it or myself. It took me over two months to get an opportunity for the picture which I secured at last one afternoon as the sun was getting low. I had been calling at intervals, and just when least expected, there they were, moving slowly but watchfully toward the creek and across the scope of the lens. My finger was quick to reach the button as they stepped to the sandy bank, and turned to note that no enemy lurked behind. The click of the shutter startled them but little, and they walked quietly away. I knew I had a good negative, as the late afternoon sun shone brightly on their gorgeous plumage, and they were barely fifteen feet from where I sat. Not one man in a million has ever had the opportunity of viewing one of these birds in life in the woods at ten to fifteen feet--nor ever will, and to these I hope the photographs will be a pleasure; for to see a ten-year-old gobbler so near, when he is not frightened--and you without gun or other means to injure him--so you may enjoy the most majestic bird the eye of man ever rested on, is not only a feast for the eye, but a pleasant memory that will be with you forever. In November, 1899, in Alabama, I began to hunt with the camera, and for six months--with the exception of one day only, on which a terrific storm raged--not a day passed that I was not after turkey pictures, sometimes not seeing one in two or three weeks, then again encountering twenty-five to forty in one day. I spoiled several hundred plates in this time, snapping at every chance that occurred. There is no possibility of a time exposure on such sensitive birds, and one twenty-fifth of a second is scarcely quick enough. Often the click of the shutter, so like the snap of a gun when missing fire, sent them whirling into the air or scattered them, pellmell, afoot. I have stalked and crawled to their scratching places and sat concealed with camera masked on an old log or in a hollow stump, till sundown; all day, and the next and the next. I have made three or four exposures in a day, gone home, developed the negatives, and found nothing on them but shadows--taken in shade; but at other times there was the just reward when all the plates came out with every image "perfect." Then, again, it would rain almost daily for a month or two. Still I went, camera slung over my shoulder, covered with a rubber sheet, hoping for sunshine. Once I discovered a bearded hen and tried five weeks to catch her with the lens, and never saw her but twice during that time. The next season I found her again in company with three other hens. I called them within ten or twelve feet. This time it had been sunlight all day, but just a minute before they came near enough a thin haze covered the sun. Still, I pressed the button and got a dim negative of her and of one of her playmates, and have not seen her since. To successfully photograph wild turkeys the greatest care must be taken in having a blind perfectly natural in appearance. Once in the blind, do not move; never mind the wind; wild turkeys cannot smell you any farther than you can them, but they can outsee anything except the heron, crane, and hawk, and you must get within fifteen or twenty feet of them in the bright sunshine, or no picture. Find their scratching places and hide behind a log, or make a blind of brush and green leaves, etc. Be sure to hide all the camera save the disk of the lens, and they will see that nearly every time. I have had them discover the lens and approach within two feet and peer at it with curious wonder, whine and purr, until satisfied it would not harm them, then walk serenely away. At times when I saw a flock or an individual feeding at a distance, I would take my call and invite them to advance, "stand up and look pleasant," and if in the humor they would often comply. I have a friend living in New Orleans with whom a hundred happy hours have been spent in the camp, wild woods, and along the stream, chiefly in quest of these noble fowls. He and I have exchanged letters once a week for the past quarter of a century. Of course I regale him with every new photograph taken of turkeys. One day I mailed him several that set him afire, and on a certain day friend Renaud came to me with his old 10-gauge which has served him thousands of times. The next morning when day broke we sat on the crest of a pine ridge adjacent to the hummock bordering the "Big-bee" river swamps, over which the turkeys roosted at night. Ere long the gray of the eastern horizon began to melt in to a rosy hue, and suddenly out of the deep swamp came the shrill, guttural but mighty pleasing "_Gil-obble-obble-obble_," of a turkey, echoing along the slopes and through the vales of the surrounding forests. After a while we heard him gobble on the ridge, so I took my call and began to pipe a few words in turkey vernacular, which the old gentleman seemed to comprehend by the way he gave ready reply. By this time the turkeys had all flown down, several gobbling in as many directions. Several were approaching slowly, and we could hear them below the crest of the hill. Luck favored us, so far as nothing yet had disturbed them, and they gradually came nearer, until presently a remark from my companion, "Old Gobbler in sight?" "See him coming, two of them, yes, three"; and on they came, their great black breasts glowing in the bright sun, while their long beards swung from side to side. Suddenly, when within thirty paces of us, one of them spied Renaud's new drab corduroy cap, which contrasted vividly with the black and charred log behind which we were hid, and "_Put_," "_put_;" all were gone, helter-skelter. Renaud's heart was broken--mine wrecked. "Why in the d-dickens didn't you shoot?" I asked, mad as a hornet. "I wanted to get them in position to get the two largest ones." "Gee! you ought to have made sure of that fellow with the immense beard, and chance another on the rise or run;" but just as we were waxing into a fine quarrel, R. remarked in a whisper, "They are coming back." "Yes," I replied, "and several others with them--some old ones and some yearlings; so make no mistake this time, and be sure of one of the old ones." They were very near now, and as I made a low call all stopped and some gobbled; then on they came in a careless manner, neither strutting nor exhibiting any special passion. I quickly got in my camera work, and ducked my head in time to see the beautiful things walking away from the gun; then two well-measured reports--and the smoke clearing away showed two grand old patriarchs flopping over on the pine straw and soon lying still. I am not sure which was the proudest--I as _particeps criminis_ or he as executioner. THE END [End logo] THE COUNTRY LIFE PRESS GARDEN CITY, N. J.	64,212	common-pile/project_gutenberg_filtered	46542	project gutenberg	project_gutenberg-dolma-0008.json.gz:188	https://www.gutenberg.org/ebooks/46542.txt.utf-8
RFrkhyeVn7e91f9T	Flint and Feather	Canadian Born The Legend of Qu’Appelle Valley I am the one who loved her as my life, Had watched her grow to sweet young womanhood; Won the dear privilege to call her wife, And found the world, because of her, was good. I am the one who heard the spirit voice, Of which the paleface settlers love to tell; From whose strange story they have made their choice Of naming this fair valley the “Qu’Appelle.” She had said fondly in my eager ear— “When Indian summer smiles with dusky lip, Come to the lakes, I will be first to hear The welcome music of thy paddle dip. I will be first to lay in thine my hand, To whisper words of greeting on the shore; And when thou would’st return to thine own land, I’ll go with thee, thy wife for evermore.” Not yet a leaf had fallen, not a tone Of frost upon the plain ere I set forth, Impatient to possess her as my own— This queen of all the women of the North. I rested not at even or at dawn, But journeyed all the dark and daylight through— Until I reached the Lakes, and, hurrying on, I launched upon their bosom my canoe. Of sleep or hunger then I took no heed, But hastened o’er their leagues of waterways; But my hot heart outstripped my paddle’s speed And waited not for distance or for days, But flew before me swifter than the blade Of magic paddle ever cleaved the Lake, Eager to lay its love before the maid, And watch the lovelight in her eyes awake. So the long days went slowly drifting past; It seemed that half my life must intervene Before the morrow, when I said at last— “One more day’s journey and I win my queen!” I rested then, and, drifting, dreamed the more Of all the happiness I was to claim,— When suddenly from out the shadowed shore, I heard a voice speak tenderly my name. “Who calls?” I answered; no reply; and long I stilled my paddle blade and listened. Then Above the night wind’s melancholy song I heard distinctly that strange voice again— A woman’s voice, that through the twilight came Like to a soul unborn—a song unsung. I leaned and listened—yes, she spoke my name, And then I answered in the quaint French tongue, “Qu’Appelle? Qu’Appelle?” No answer, and the night Seemed stiller for the sound, till round me fell The far-off echoes from the far-off height— “Qu’Appelle?” my voice came back, “Qu’Appelle? Qu’Appelle?” This—and no more; I called aloud until I shuddered as the gloom of night increased, And, like a pallid spectre wan and chill, The moon arose in silence in the east. I dare not linger on the moment when My boat I beached beside her tepee door; I heard the wail of women and of men,— I saw the death-fires lighted on the shore. No language tells the torture or the pain, The bitterness that flooded all my life,— When I was led to look on her again, That queen of women pledged to be my wife. To look upon the beauty of her face, The still closed eyes, the lips that knew no breath; To look, to learn,—to realize my place Had been usurped by my one rival—Death. I started up—and bending o’er my dead, Asked when did her sweet lips in silence close. “She called thy name—then passed away,” they said, “Just on the hour whereat the moon arose.” Among the lonely Lakes I go no more, For she who made their beauty is not there; The paleface rears his tepee on the shore And says the vale is fairest of the fair. Full many years have vanished since, but still The voyageurs beside the campfire tell How, when the moonrise tips the distant hill, They hear strange voices through the silence swell. The paleface loves the haunted lakes they say, And journeys far to watch their beauty spread Before his vision; but to me the day, The night, the hour, the seasons are all dead. I listen heartsick, while the hunters tell Why white men named the valley The Qu’Appelle.	907	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/flintandfeather/chapter/the-legend-of-quappelle-valley/	pressbooks	pressbooks-0000.json.gz:17134	https://pressbooks.library.torontomu.ca/flintandfeather/chapter/the-legend-of-quappelle-valley/
yVHRo6T02QXqW0fX	Philosophy-A Short History3	54 Soren Kierkegaard: Fear and Trembling Sören Kierkegaard is one of the towering Christian existential thinkers of the mid-nineteenth century. While his literary style was experimental, his writings call for Christian morality; a defense of faith and religion. Among his many books are Training in Christianity, Sickness Unto Death, and Fear and Trembling. Translated by Walter Lowrie. Published by Princeton University Press, 1941. This material was prepared for Religion Online by Ted and Winnie Brock. SUMMARY (ENTIRE BOOK) The great mid-nineteenth century Danish poet-philosopher, in this classic philosophical text, explores, through the story of Abraham and his willing sacrifice of his son Issac, the nature of belief. It is in this text that Kierkegaard most clearly reveals his philosophical “leap of faith.” Chapters - PrefaceKierkegaard, writing under a pseudonym (Johannes De Silentio), aims ironic criticism his own work. He claims the “writer” is nothing of a philosopher, has not understood “the System,” and does not know whether it actually exists. - PreludeThe story of Abraham is given a Kierkegaardian turn, full of paradoxes and inconsistencies. Abraham could not comprehend that it was a sin to be willing to offer to God the best thing he possessed — his own son Isaac. - Chapter 1: A Panegyric Upon AbrahamThe beginnings of a reverie – sermon on the sacrifice of Isaac by his father Abraham. - Chapter 2: Preliminary ExpectorationThe story of Abraham has the remarkable property that it is always glorious, however poorly one may understand it. The ethical expression for what Abraham did is that he would murder Isaac, and the religious expression is that he would sacrifice Isaac. Abraham had to live with this contradiction which could make a man sleepless. But Abraham is not what he is without this dread. - Chapter 3: Problem One: Is There Such a Thing as a Teleological Suspension of the Ethical?The dialectical consequences in the story of Abraham are expressed here in the form of problemata in order to see what a tremendous paradox faith is, for this story presents the paradox which gives Isaac back to Abraham, which no thought can master, because faith begins precisely there where thinking leaves off. - Chapter 4: Problem Two: Is There Such a Thing as an Absolute Duty Toward God?The knight of faith is obliged to rely upon himself alone, he feels the pain of not being able to make himself intelligible to others, but he feels no vain desire to guide others. - Chapter 5: Problem Three: Was Abraham Ethically Defensible in Keeping Silent About His Purpose?Abraham’s conduct is indefensible for he paid no heed to the intermediate ethical determinants. But in the face of his concealment, we are in the presence of a paradox which cannot be mediated, for it rests on the fact that the individual is higher than the universal. - EpilogueFaith is the highest passion in a man. There are perhaps many in every generation who do not even reach it, but no one gets further. But for the man also who does not so much as reach faith, life has tasks enough, and if one loves them sincerely, life will by no means be wasted. Feedback/Errata	686	common-pile/pressbooks_filtered	https://pressbooks.cuny.edu/philosophyashorthistory3/chapter/fear-and-trembling-religion-online/	pressbooks	pressbooks-0000.json.gz:84961	https://pressbooks.cuny.edu/philosophyashorthistory3/chapter/fear-and-trembling-religion-online/
WMBoJkCVNKLJkxE_	Curriculum Essentials: A Journey	16 Curriculum Innovations “Curriculum holds an outstanding place when seeking to promote innovation in education, as it reflects the vision for education by indicating knowledge, skills, and values to be taught to students. It may express not only what should be taught to students, but also how the students should be taught.”-– Kiira Kärkkäinen Introduction Innovation means doing things in new ways, and in curriculum, it means adopting different designs for learning to help make learning more meaningful for 21st-century learners. Some practices in education have become outmoded, and learning experiences should be redesigned to be more relevant to student interests, abilities, and cultures. An additional challenge is that with a more diverse population of students who have a broad range of abilities, innovations must be linked to curriculum goals as well as being challenging and differentiated to provide for an array of learning experiences. Essential Questions - What are the three main models of curriculum innovation? How are they the same? How are they different? - What are the most important change agents in a school? - What are the STEM and STEAM initiatives? - What are the implications regarding what has been learned about curriculum in the past ten years according to Sal Khan? Curriculum Change From Curriculum Studies, pp. 108-113 Curriculum change is inevitable in any society. These changes occur because there is not perfect curriculum, and there is most often a need to adjust to the economic, technological, social, political, and ideological needs in the society. Change can be perceived at three levels. Minor changes involve re-arrangement of subject content, learning activities, re-organization of personnel, addition of topics or methods in the curriculum project. Medium changes involve not only organizing of content, materials or facilities, but it involves integration of subjects or new approaches to the existing subjects. On the other hand; Major change involves an overhaul of the existing curriculum. It may entail a complete re-organization of the conceptual design of the curriculum, changes in structure, content, methods and approaches. Changes in resources and facilities can also lead to a totally new curriculum plan or program. For curriculum change to occur, there are certain agencies involved in the process. Let us examine some of them. Agencies of Curriculum Change Agencies of change include institutes of education, curriculum development centers, research institutes, schools, colleges, universities, departments of education, publishing companies, school districts, school boards, and communities. Curriculum Innovations Innovation involves the introduction of something new in curriculum that deviates from the standard practice, often because society has changed and so must the curriculum. To meet these changes, innovations are created. An innovation must fit in with the goals and objectives of education which usually reflect the needs, interests, values and problems of the society. An innovation must be appropriate, economical in terms of time, space and resources and be aligned with the philosophy of the society and the school and rooted in sound educational theory. Models of Curriculum Innovation Various scholars have proposed different models of innovation. For instance, Ronald Havelock (1969) identified three main models of innovation: - Research, Development, and Diffusion (RD&D) model - Social Interaction (SI) model - Problem-Solving (PS) model The Research, Development and Diffusion (RD&D) Model In this model, an idea or practice is conceived at the central planning unit and then fed into the system. RD&D is effective where curriculum development is done on a large scale and ideas have to reach wide geographical areas and isolated users. It is a highly organized, rational approach to innovation. Following is a logical sequence of activities in using the RD&D model: - basic research by a central project team which develops a new curriculum, devises and designs prototyped materials, - field trials of the prototyped materials, and redesigns them where necessary, - mass production of the modified prototyped materials, - mass dissemination or diffusion of the innovation through courses, conferences, and workshops, and - implementation of the innovation by the users (school, teachers, and pupils). The model can be summarized as follows: This model is used in areas that have centralized systems of education, such as universities or departments of education. The Social Interaction (SI) Model The model grew out of the progressive education movement in the 1930s when it split into two camps: one that focused on the individual student as a learner and the other on society as an education laboratory (Ellis, 2004). This view sees students as capable of reforming society with support from leadership to provide a curriculum that may become “a classroom without walls” and a community where students and teachers can ultimately change the world (Ellis, 2004). This model operates through social interaction and emphasizes communication. It stresses the importance of interpersonal networks of information, opinion of leadership, personal contacts, and social integration. The model also has its roots in the notion of democratic communities “helping students to be as well as to become.” (Sergiovanni, 1994). The SI model also stresses the relationship of the individual to other people and society, and the instructional methods used by teachers in the classroom to facilitate group work. The model is student-centered, and students are encouraged to interact with each other in a structured setting. When implementing this strategy, students often serve as facilitators of content and help their peers construct meaning. The students are to question, reflect, reconsider, seek help and support, and participate in group discussions. The three most common strategies include: - group projects, - group discussions, and - cooperative learning (Patel, 2013). The interactions are often face-to-face but may also be interactive using online tools and technologies. The steps of instruction using social interaction often vary, but they have these steps: The Problem Solving (PS) Model The PS model is based on the assumption that innovation is part of a problem-solving process. The following steps are characteristic of the PS model. The PS model is referred to as a “periphery-center” approach to innovation. The innovations are initiated, generated, and applied by the teachers and schools based on their needs. Such innovations have strong user commitment and the best chance for long term survival. In this model, the receiver is actively involved in finding an innovation to solve their own unique problem. The model is flexible enough to encompass all types of innovations, including materials, methods, and groupings of learners. Thus, the PS model is local in nature, usually limited in size, and may not be of high quality compared with more centralized approaches to curriculum development. The following STEM and STEAM initiatives incorporate innovative strategies to promote problem-solving as part of the science, technology, engineering, and mathematics curriculums. STEM Initiative The term “STEM” was introduced as a way to refer to careers and curriculum centered around Science, Technology, Engineering, and Mathematics. These curriculum disciplines are closely connected to many industries in the U.S. and other countries. The government and private companies are continually challenged to develop cutting-edge technological innovations to stay competitive globally. For this reason, the integration of more STEM education in school curriculums has gained a lot of traction (Thomas, 2020). The STEM initiative falls under the first innovation model, RD&D, because of the various components of the initiative that are research-based. One of the innovative strategies that has been successful in spreading is the Student-Centered Active Learning Environment with Upside-down Pedagogies (SCALE-UP). This modifies the way of teaching and the classroom design so that interaction and activity-based learning is maximized (Foote, et al, 2014). STEM Explained From Wikipedia Science, technology, engineering, and mathematics In 2018, Pew Research revealed that Americans identified several issues that influence STEM education, including unconcerned parents, disinterested students, obsolete curriculum materials, and too much focus on state parameters. More than 50 percent of survey respondents pointed out that one main problem of STEM is the lack of students’ concentration during learning. The National Assessment of Educational Progress (NAEP) recently included Technology and Engineering Literacy (TEL) assessment measures that reported how students could apply technology and engineering skills to real-life situations. TEL uses interactive scenario-based tasks to gauge what students know and can do. The TEL assessment was given in 2018 to approximately 15,400 students in grade 8. The report showed a gap of 28 points between low-income students and their high-income counterparts. The same report also indicated a 38-point difference between white and black students (NAEP, 2021). The Smithsonian Science Education Center (SSEC) announced the release of a five-year strategic plan by the Committee on STEM Education of the National Science and Technology Council on December 4, 2018. The plan is entitled “Charting a Course for Success: America’s Strategy for STEM Education.” The objective is to propose a federal strategy anchored on a vision for the future so that all Americans are given permanent access to premium-quality education in STEM. In the end, the United States can emerge as a world leader in STEM mastery, employment, and innovation. The goals of this plan are building foundations for STEM literacy; enhancing diversity, equality, and inclusion in STEM; and preparing the STEM workforce for the future. Employment in STEM occupations has grown 79 percent since 1990, from 9.7 million to 17.3 million, outpacing overall U.S. job growth. There’s no single standard for which jobs count as STEM, and this may contribute to several misperceptions about who works in STEM and the difference that having a STEM-related degree can make in workers’ pocketbooks. National funding for K-12 STEM programs increased from $700 million to almost $1 billion from 2005 to 2007 alone (US DOE, Report of the Academic Competitiveness Council, 2007, p. 51). STEM education is more than just a new name for the traditional approach to teaching science and mathematics because it crosses the traditional barriers between the four disciplines by integrating them into a cohesive means of teaching and learning. The engineering component emphasizes the process and design of solutions instead of just the solutions themselves. This allows students to explore math and science in a more meaningful context and helps students develop critical thinking skills that can be applied to their work and academic lives. The technology component allows students to apply what they have learned, by using computers with specialized and professional applications like CAD and computer animation. These and other applications of technology allow students to explore STEM subjects in greater detail and in a practical manner (National High School Alliance, 2010). Many STEM programs focus on post-secondary education, but there is an increasing number that focus on K-12 programs. This is a serious STEM challenge at the K-12 level. What are the characteristics of high-quality STEM programs? Research has identified the following characteristics of effective STEM programs: - Programs should broadly address student learning, including core content knowledge and critical thinking skills as defined by the relevant standards from professional organizations such as the following: International Technology and Engineering Educators Association (ITEA), - International Society for Technology in Education (ISTE), - National Research Council (NRC), the National Council for Teachers of Mathematics (NCTM), - National Science Teachers Association (NSTA). - Programs should address student engagement (by illustrating the value of STEM in students’ lives, as well as building interest in STEM fields and encouraging students to pursue STEM-related careers). - Programs should have an over-arching STEM “framework” which maps standards for knowledge, skills, and dispositions to curricular activities. - Programs should integrate the teaching of all four STEM areas into a “meta-discipline.” STEM in Action From BIO-MED Science Academy STEM School One example of an exemplary STEM school is the Bio-Med Science Academy in Ohio which opened in 2012. This STEM school serves students in grades 2nd-12th on three campuses, and the students experience STEM learning within the framework of a balanced curriculum that integrates the arts, humanities, and sciences. Additionally, BMSA leverages our region’s great scientific, medical, academic, and business assets to engage students directly with practicing professionals. Students gain exposure to a range of industries through speakers, internships, field experiences, and other opportunities that prepare them for real-world living and working. The result is an inquiry-based, individualized learning experience that positions students to succeed in any number of career fields, including, perhaps, fields yet to be created. The Academy seeks to produce not just future mathematicians, engineers, doctors, and scientists, but leaders in all fields. - The first class of 69 ninth graders came from 27 school districts across 5 counties, and the school received formal STEM designation in 2013. It is a member of the Ohio STEM Learning Network (OSLN), and is recognized with other STEM schools across the state and the nation. The Academy is the only STEM school in the United States housed on an academic health center campus, and one of few located in a rural area. This unique positioning gives rural Ohio students and their teachers direct access to sophisticated research laboratories, scientists, professors, and medical professionals. The environment creates a dynamic learning experience for the Academy students. There are many excellent STEM programs across the country. ILA 16.0 OER Commons has an overwhelming amount of STEM resources. Finding STEM OER that works for you can be quite a task. Access the OER Commons website and utilize the following STEM OER Commons Scavenger Hunt to guide you through strategies for accessing the different STEM resources OER Commons has to offer. Have fun! STEM OER Scavenger Hunt STEAM Education After STEM became a force in the world of education, a new, and very similar term emerged — STEAM. The “A” in steam refers to arts. And this addition plays a critical role in how we need to be preparing our youth for the future. Why Add Art to The STEM Framework? To provide a better understanding of how STEAM came about and the importance of implementing a STEAM learning environment, it is important to look at what the “A” or art brings to the table, and how educators can implement this framework to enhance students’ education and development. STEAM is a progression of the original STEM acronym, with an additional element: art. Why the change? The integration of the arts into STEM learning has allowed educators to expand the benefits of hands-on education and collaboration in a variety of ways, promoting creativity and curiosity at the core. (Thomas, 2020). Another reason for the addition of arts is that creative scientists are needed in a world with a greater population, global interconnection, technological advancement, and more large-scale problems than ever before in human history. Complex problems require sophisticated problem-solving skills and innovative, complicated solutions (Madden, et. al, 2013). In the United States, scientists are educated in colleges and universities using an approach that began decades ago, even though there are now different demands on science with new challenges. Traditional science training is built on a solid foundation of facts and basic science techniques, but it seldom includes creative, cross-disciplinary problem identification, and solving skills (Madden, et. al, 2013). Many leading corporations are eager to identify ways to promote creativity in science that encourage innovations and will be needed to solve complex problems. It is important to empower students with creativity and critical thinking skills because it will give them additional opportunities to be successful in real-world, professional settings, and problem-solving situations (Thomas, 2020). In a report titled “Critical Evidence: How the ARTS Benefit Student Achievement,” the National Assembly of State Arts Agencies (NASAA) shared data showing why it is important to keep the arts strong in schools, and how students benefit from the integration of arts in the curriculum. In the study, researchers found that students scored higher on standardized tests when they were more active in the arts — compared to those who were less active in the arts. The same students reportedly also watched less TV, felt less bored in school, and participated in more hours of community service (Thomas, 2020). RD&D Initiative That Supports PS and SI There are several examples of the RD&D curriculum model, but one of the most established initiatives that is research-based and designed to support K-12 curricula is the Center for Innovation in Engineering and Science Education or CIESE at the Stevens Institute of Technology in New Jersey. For the past 20 years, it has strengthened the STEM initiative by designing and promoting multidisciplinary STEM curricula for educators that can be accessed globally for K-12 school curriculums. The lessons and projects are research-based, and also promote problem-based learning, collaboration, higher-order thinking skills, and critical analysis through the integration of science, technology, engineering, mathematics as well as language arts and social studies. Many of the CIESE projects use real-time data from scientific and government databases. These curricula engage students in global collaboration using pooled data from shared databases, and also involve student publishing on the Web. Unique and primary source information is available to students. One of the innovative features of the CIESE program, the Real-World Learning Objects, has a library of instructional activities that supports the teaching of discrete topics such as exponential functions in mathematics or genetic traits in biology that are appropriate for high school (CIESE, Stevens Institute of Technology, 2020). Access the catalog of projects, lessons, and activities that are currently offered as part of the CIESE K-12 Curriculum and Resources for more information. The interdisciplinary STEM projects that make use of online real-time data focus on collaborative projects that connect students to peers and experts around the world, so there is an element of the SI as well as the PS models. This initiative fits into all three categories of curriculum innovation at varying levels. The project catalog is organized by science (life, Earth, physical, environmental); technology (real-time data, online collaboration, primary sources, robotics); engineering (systems, civil, mechanical, electrical, general); math (numbers and operations, algebra, geometry, trigonometry, data analysis). Most of the projects overlap more than one category. SI Technology With the swift progression of in-class to online teaching, technology has taken center stage with online learning platforms, remote class and small group meetings, and individual student-teacher conferences, and a host of tech tools that are being developed. Since the SI model depends on the students interacting with each other, technology can support learning in other ways such as discussion forums and chat rooms. Teachers can monitor students, promote on-task behaviors, and help students through e-conversations. The primary source of information is the internet which opens the door to a vast amount of data that may or may not be accurate or relevant. It is up to the teacher to show students strategies for sifting this information. Since the curriculum is based on social issues and democracy in the classroom, students must have a say in the curriculum (Bean, 1997). It also requires students to practice social skills so they can learn effectively in a group. Innovative Curriculums Can Be Built by Teams The Alain Locke PK-8 Charter School in Chicago, Illinois, has been designated as a demonstration site for urban schools. The school’s goal is to produce globally competitive students. It has a learner-centered approach that prepares students for college, as well as an extended day center, and a year-round academic program with a short summer break. Ninety-four percent of the students qualify for free and reduced lunch prices. The curriculum includes Spanish, technology, the arts, music, library, and physical education as well as personal and social development. It has an additional 10 days of instruction per year with three-in-a-half extra hours of instruction a day. The Alain Lock School was profiled by the U.S. Department of Education for making significant growth towards closing the achievement gap in their community. Pat Ryan, co-founder of the Alain Locke Charter School has stated that there are three counterintuitive truths about great schools: Figure 16.6 – Three Counterintuitive Truths about Great Schools Visit the Alain Lock School for more information. In another interpretation of Great Schools, Dr. John Hattie of Melbourne University believes there are many great schools that “invite kids to learn” and they are the schools that students find inviting because they are a great place to learn. Students get information on their progress, and teachers know they can influence character development and a moral purpose. It is the effort that makes the difference. The excellent teachers are the ones who make an impact on students by helping them achieve and also build character. Dr. Hattie explains this in more detail in What Great Schools Do – John Hattie – VASSP2012. Innovations Can Be Built by One Person (The following is taken from an interview with Sal Khan from The Harvard Business School Alumni Stories by Garry Emmons in 2012). Sal Khan had three degrees from M.I.T. and an MBA from Harvard and was working for a hedge fund in Boston when he got a phone call from his nine-year-old cousin, Nadia. “Sal,” she asked, “can you please help me with my homework?” That simple question led to amazing and dynamic innovation in education. Using Yahoo! Doodle as a shared notepad, Sal tutored Nadia in math via computer and telephone. Soon, other cousins and their schoolmates wanted help, too. Khan said, “It was getting crazy, so in 2006, a friend suggested that rather than reteaching the same points over and over again to different kids, he should make videos of each lesson and put them on YouTube.” He was skeptical. YouTube was for cats playing the piano, not serious mathematics! Then he had an idea and made a couple of videos. The initial feedback from the cousins was good so he kept going. By 2009, Khan had quit his job to work on the videos—and the software—full time. To date, he has made around 3,000 videos—and loves doing them—on dozens of subject areas, ranging from physics to finance to history. It’s all free to everyone and anyone, and all kinds of learners seem to like them. As the website says, the tally as of early February is now “119,074,255 lessons delivered.” What is the Secret of the Success of the Videos? Khan tries not to talk down or be judgmental, and he is off-camera—the less distraction the better—so it’s just a voice-over—and informal and without a script. He does his best to give students a deeper understanding rather than just learning things by rote. The screen image is of a chalkboard, simulated through software, and he “writes” on it as the lesson develops. His cousins have told him they like this “virtual Sal” better than the real-life one. In response Sal said, “They can start and stop and repeat me at will.” The Khan Academy and Experimentation with Nearby Schools The Los Altos school system, which is close to where Khan lives, is using his Academy on an experimental basis. It’s early, but the results look promising. Students spend part of class time—and some time at home—working at their own pace on videos and exercises. They get immediate feedback, and there are game mechanics—points and badges—to provide even more motivation. Every interaction with the system is logged, and this data is used to give students, teachers, and parents real-time reports on student progress. In the same classroom, there will be some fifth graders working on trigonometry and some reviewing basic arithmetic. The teacher no longer spends class time lecturing but focusing instead on small-group interactions with students who need help. The students also teach each other. Every student is working at their own pace, and time is freed up in class to work on more open-ended projects. Khan says that even more than the student-to-teacher ratio, this optimizes the student-to-valuable-time-with-the-teacher ratio. This model gels with the best learning experiences Khan had in his own public school in Louisiana. “Whether it was being on the math team, the school paper, or the wrestling team, the teachers in those situations were more like mentors with whom you worked collaboratively to achieve personal and team goals. Teammates would help, too. Everybody was trying to get the best possible result, without that teacher versus student antagonism. That’s the way learning should happen.” Future Plans for the Khan Academy Khan plans to eventually open a brick-and-mortar school because he believes they are effective, but it will have a different environment and setup because he believes that traditional schools “can be dehumanizing, and students are sometimes belittled, not allowed to talk, interact or be creative. They don’t allow students to move at their own pace.” Khan also believes that he and his team of about 20 people are creating something that hasn’t existed before (true innovation!) that will still be around in 200 or 300 years. He wants his website to be something that has the content and tools of a world-class that is free or provides a low-cost education for everyone, the way clean drinking water and electricity are today. His website is free, but he knows there is a cost for computers and bandwidths, which are relatively inexpensive and are becoming cheaper. Sal Khan believes there is a hunger for deep learning, and he wants to remain a not-for-profit so Khan Academy is accessible to everyone who wants to learn. In fact, he would like to feel that he has helped give “billions of people around the world access to a truly first-rate education.” What Have We Learned About Curriculum in the Last Decade? As an innovator, Sal Khan sums up what he thinks we have learned about curriculum in the past decade: Insight 16 It is inspiring to find out about the many innovations that are taking place in education today. Some are the result of changes in society, some are born out of a simple question like, “Can you please help me with my homework?” It is interesting to me, as an educator with several decades of teaching experience, to find out that innovators in education see teachers as the “unwavering center of schooling,” and that students need a grade-level curriculum that is rigorous. Despite today’s challenges, public schools are making progress. The new, not-so-secret piece of the puzzle that also helps make it work for everyone is the ethic that education can and should be available to all people who want to learn at low or no cost, such as the Khan Academy and other Open Educational Resources. As an educator, I am excited to see these innovations in education. It makes my personal curriculum journey very interesting and one well worth continuing. Summary Curriculum changes occur because societies have new needs and issues. These changes may be in response to curriculum evaluations or reviews, or the culture. Curriculum may also change in response to economic, social, and political issues as well as access to technology and curricular innovations. On the other hand, it is the introduction of something new that makes the difference from previous practices. Exemplary initiatives, programs, and schools make use of innovations. STEM and STEAM curriculums can support students to achieve in the sciences, technology, engineering, and mathematics, as well as art, social studies, and literacy by integrating these subjects. Many exemplary schools focus on closing the achievement gap for students who live in high needs areas. Sal Khan is an innovator who has a vision for the future of education that will benefit people in the U.S. and globally.	5,882	common-pile/pressbooks_filtered	https://oer.pressbooks.pub/curriculumessentials/chapter/chapter-curriculum-innovations/	pressbooks	pressbooks-0000.json.gz:31093	https://oer.pressbooks.pub/curriculumessentials/chapter/chapter-curriculum-innovations/
1py7QBbMrF5Yf69a	Report of the American committee on electrolysis, 1921.	Library Copies of this report m£y be purchased at one dollar eaoh from the Secretary of . the American Institute of Electrical Engineers, 33 West 39th Street, New York, N.Y. destructive effects due to electrolysis. The Committee, through its Research Subcommittee, has established a close working relationship with the National Bureau of Standards, which has been distinctly advantageous. The Committee regrets to chronicle the death in Washington on May 17, 1921, of its secretary, Dr. Edward B. Rosa, Chief Physicist of the National Bureau of Standards, one of its most efficient and esteemed members. A. ELECTROLYSIS IN GENERAL. 1. Electrolysis is the process whereby an electric current passing from an electrode to an electrolyte or vice versa causes chemical changes to take place in the electrolyte. Electrolysis also includes any chemical changes at the surface of an electrode resulting from the chemical changes in the electrolyte. Electrolysis is independent of the heating effect of the electric current. NOTE. These changes usually occur in a water solution of an acid, alkali, or salt. By the passage of an electric current through it, water (containing a trace of acid) is decomposed into hydrogen and oxygen, copper is deposited from a solution of copper sulphate, silver from solutions of silver salts. Electroplating, electrotyping, and refining of metals by electrodeposition are useful applications of electrolysis in the arts. Electrolysis is involved in the charge and discharge of storage batteries, and in the operation of primary batteries. current. 2. Electrolyte, Electrode, Anode, Cathode. The electrolyte is the solution (or fused salt) through which the electric current flows; the conducting terminals are the electrodes; the terminal by which the current enters the solution is the anode; the terminal by which it leaves is the cathode. NOTE. The chemical changes caused by the current may affect both the electrolyte and the electrodes. In the case of a solution of copper sulphate with copper plates as electrodes, copper is removed from the anode by the current and carried into solution; an equal amount of copper is deposited upon the cathode. In general the metal travels with the current toward the cathode. 3. Amount of Chemical Action. (Faraday's Law.) The amount of chemical action taking place at the anode and also at the cathode (as expressed by Faraday's Law) is proportional to (1) the strength chemical equivalent weights of the substances. NOTE. Otherwise expressed, the quantity of metal or other substance separated is proportional to the total quantity of electricity passing and the electro-chemical equivalent of the substance or substances concerned. The electro-chemical equivalent of a metal is proportional to its atomic weight divided by its valence. Faraday's Law is so exactly realized in practice under favorable conditions that it is used as the basis for the definition of the international ampere, one of the fundamental electrical units. (See Passivity, Paragraph 15.) 4. Cause of Current Flow. The current flowing through the electrolyte may be due (1) to an external electromotive force or (2) to the difference of potential due to the use of electrodes of different materials or to solutions of different concentrations. NOTE. The first case is illustrated by electrolysis of dilute sulphuric acid using two lead plates and an external battery; the second by the electrolysis of the same solution using a zinc and a copper plate, which touch each other inside or outside the solution. The first occurs in charging a storage battery; the second in the discharging of a primary battery or a storage battery. 5. Electrolysis by Local Action. Instead of two plates of different metals the same result may follow with one plate if it is chemically impure or otherwise heterogeneous, when immersed in an electrolyte. NOTE. Such a plate excites local currents and a loss of metal occurs at all the anode areas. This local action causes impure zinc to dissolve rapidly in a solution which has no action on pure zinc. electrolysis at the anode. NOTE. When iron is anode the iron is carried into solution by the current, the first product being a salt of iron, the nature of which depends upon the character of the electrolyte. In dilute sulphuric acid, ferrous sulphate is formed ; in hydrochloric acid, ferrous chloride, etc. These first products of electrolysis are frequently modified by secondary reactions. sometimes followed by other reactions. NOTE. Ferrous hydroxide formed by the union of iron with hydroxyl ions set free at the anode, is subsequently converted into iron oxide due to the reactions with oxygen dissolved in the electrolyte. When lead is cathode in an alkali soil or solution, the alkali metal (such as sodium or potassium) reacts with water at the cathode and forms alkali hydroxide, setting hydrogen free. This hydroxide may react with the lead chemically and form lead hydroxide (especially after the current ceases), which in turn may combine with carbon dioxide, forming lead carbonate. 8. Calhodic Corrosion is the term applied to the corrosion due to the secondary reactions of the cathodic products of electrolysis, as described in the preceding paragraph. The metal of the cathode is not removed directly by the electric current but may be dissolved by a secondary action of alkali produced by the current. NOTE. The anodic corrosion is more common and more serious; cathodic corrosion, however, sometimes occurs on lead and other metals that are soluble in alkali. Cathodic corrosion never occurs in the case of iron. B. ELECTROLYSIS OF UNDERGROUND STRUCTURES. 9. General. As used in this report, the term "electrolysis" embraces the entire process of accelerated corrosion of underground metallic structures due to stray current. In the electrolysis of gas arid water pipes, cable sheaths, and other underground metallic structures, and the rails of electric railways, the moisture of the soil with its dissolved acids, salts, and alkalis is the electrolyte, and the metal pipes, cable sheaths and rails are the electrodes. NOTE. Wherever the current flows away from the pipes they serve as anodes and the metal is corroded. Metal or gas or alkali, according to the nature of the soil, will be set free at the cathode. . 10. Self Corrosion is the term applied when a pipe or other mass of impure or heterogeneous metal buried in the soil is corroded due to electrolysis by local action. NOTE. This is called "self corrosion" because the electric current originates on the metal itself, without any external agency to cause the current to flow. Self corrosion may also be due to direct chemical action. 18 PRINCIPLES AND DEFINITIONS lower its resistance as an electrolyte, and also by cinders, coke or some other conducting particles of different electric potential which augment the local electric currents. In the latter case the metal need not be heterogeneous. certain soils. 12. Stray Current is that current which has leaked from the return circuit of an electric railway system and flows through the earth and metallic structures embedded therein. 13. Anodic and Self Corrosion. Anodic corrosion due to stray currents and self corrosion due to local action may occur simultaneously, and the former may accelerate the latter. NOTE. Hence the corrosion due to a given current plus the increased self corrosion induced by that current may give a greater total corrosion than called for by Faraday's Law. This explains how the coefficient of corrosion may exceed unity. 14. Coefficient of Corrosion. The coefficient of electrolytic corrosion (sometimes called corrosion efficiency) is the quotient of the total loss of metal due to anodic corrosion (after deducting the amount of self corrosion if any) divided by the theoretical loss of metal, as calculated by Faraday's Law, on the assumption that the corrosion of the anode is the only reaction involved. NOTE. In practice it is found that the coefficient of corrosion varies widely from unity, being sometimes as low as 0.2 and sometimes even above 1.5, but commonly between 0.5 and 1,1. 15. Passivity is the name given to the phenomenon in which a current flows through an electrolyte without producing the full amount of anodic corrosion which would occur under normal conditions. NOTE. This restricted definition of passivity has regard only to its effect in electrolysis. Many conditions affect the degree of passivity attained, an initial large current density being favorable to it. Plunging iron into fuming nitric acid renders it temporarily passive. A satisfactory explanation of passivity has not been given. 16. Polarization Voltage (sometimes called polarization potential) is the temporary change in the difference o'f potential "between an electrode and the electrolyte in contact with it due to the passage of a current to or from the electrode. This change in potential difference is due to the change in the conditions of the surface of the electrode or change in the concentration of the electrolyte (or both), and under some conditions is approximately proportional to the current flowing, but in many cases is not so proportional. The magnitude of the polarization voltage also depends on the material of the electrode, the nature of the electrolyte, and the direction of the current. 17. Alternating or Frequently Reversing Direct Currents. If alternating currents (or frequently reversing direct currents) flow through the soil between pipes or other underground metallic structures, the metal removed during the half cycles when a pipe is anode may be in part replaced when it is cathode. Hence, the total loss of metal on a given pipe may be less than is indicated by computing the loss on the basis of the positive part of the cycle only, and in the case of alternating current at commercial frequency may be less than 1% of such computed values. NOTE. In slow reversals of current the recovery effect is less, but the loss will be less than with direct current continuously in the same direction (excepting possibly where the phenomenon of passivity may affect the result). 18. Action on Underground Metallic Structures. Faraday's Law applies to electrolysis of metallic structures in soil as elsewhere, the total chemical action being proportional to the average current strength and the time the current flows and to the electrochemical equivalent of the metal of other substances concerned. Although local action and passivity affect the loss of metal and so apparently modify Faraday's Law, it is still true that the total chemical action resulting from the current flow is proportional to the total current when local currents are included. NOTE. Sometimes this chemical action is concerned only with corroding the anode; sometimes it is concerned with breaking up the electrolyte, as when the anode is a noble metal or in the passive state (as iron and lead sometimes are) : sometimes both these effects occur. The theoretical loss of iron per year per ampere is about twenty pounds and of lead is 3.7 times this amount or about seventy-four pounds. The loss in volume of lead is 2.4 to 2.6 times that of iron. The greater loss in lead is due to the higher electrochemical equivalent of that metal. through the earth and the metallic structures buried in the earth, (2) the reduction of the anode areas of such structures to a minimum, where the current is not substantially eliminated in order to reduce the area of destructive corrosion as far as possible. NOTE. The current in the underground metallic structures will be decreased, other conditions remaining the same, by (1) increasing the conductance of the return circuit, (2) increasing the resistance of the leakage path to earth, (3) increasing the resistance between the earth and the underground metallic structures, (4) increasing the resistance of the underground metallic structures. The anode areas of the underground metallic structures will be decreased, other conditions remaining the same, by providing suitably placed metallic conductors for leading the current out of the underground structures so that the flow of the current directly to the earth shall be minimized. This will change a portion of the anode area to cathode. 20. Electrolysis Survey. An electrolysis survey is the operation of determining by means of proper measurements all relevant facts pertaining to electrolysis conditions, such as the voltage drop in the grounded railway return; the location and extent of the areas in which the metallic structures are in danger from stray currents; the condition of the structures and adjacent soil in the danger areas, and the extent of any damage that may have occurred; the seriousness of electrolytic action in progress and the source of the stray current producing the damage, its course and magnitude and the conditions in neighboring structures tending to produce electrolysis. If will generally be found desirable to make some preliminary tests for the purpose of indicating the lines along which the complete survey should be made. 21. Overall Potential Measurements. Overall potential measurements are measurements which are made to determine the difference in electric potential between points in the tracks at the feed limits of the station and the point in the tracks which is lowest in potential, and are obtained by means of pressure wires and indicating or recording voltmeters. This is most commonly applied to measurements of voltage between the point of lowest potential in the grounded portion of a railway return system and the points of approximately highest potential on its various branches. 23. Potential Difference. In electrolysis work the term "potential difference" usually means the difference in potential which exists between nearby points on separate systems of conductors, or between conductors and the earth, e.g., between pipes and rails, lead sheaths and rails, lead sheaths and earth, etc. values of the same polarity. 25. Algebraic Average. The algebraic average value of a current or potential is the algebraic sum of all the instantaneous values, divided by the number of such values. 26. Positive and Negative Areas. Positive areas are those areas where the current is in general leaving the pipes or other underground metallic structures for the earth. Such areas are often called danger areas. flowing to the pipes or other underground metallic structures. NOTE. As the current often flows from one underground metallic structure to another, it is evident that within a positive area there are local negative areas and vice versa. Hence the terms are applied somewhat loosely, and according to which condition predominates. Besides the positive and negative areas there are areas of more or less indefinite extent in which the current flow between metallic underground structures and earth normally reverses between positive and negative values. These areas are called neutral areas or neutral zones. 27. Drainage System. A drainage system is one in which wires or cables are run from a negative return circuit of an electric railway and attached to the underground pipes, cable sheaths or other underground metallic structures which tend to become positive to earth, so as to conduct current from such structures to the power station, thereby tending to reduce the flow of current from such 'structures to earth. NOTE. Three kinds of drainage systems may be distinguished : (1) where direct ties with wires or cables are made between underground metallic structures and tracks, (2) where uninsulated negative feeders are run from the negative bus to underground metallic structures, (3) where separate insulated structures. 28. Uninsulated Track Feeder System. An uninsulated track feeder system is one in which the return feeders are electrically in parallel with the tracks. Under such circumstances the cables may be operating very inefficiently as current conductors and as a means of reducing track voltage drop, particularly where voltage drops in the grounded portion of the return are maintained at the low values usually required for good electrolysis conditions. (See Chapter 2, Reinforcement of Rail Conductivity.) 29. Insulated Negative Feeder System. An insulated negative feeder system, sometimes called an insulated return feeder sysem, or insulated track feeder system, is one in which insulated wires or cables are run from the insulated negative bus in a railway power station and attached at such places to the rails of the track as to take current from the track and conduct it to the station in such a manner as to reduce the potential gradients in the tracks and the differences of potential between underground metallic structures and rails, thereby reducing the flow of current in underground metallic structures. (See Chapter 2, Insulated Negative Feeder System.) NOTE. The insulated negative feeders may run separately from the negative bus to various points in the track network, or a smaller number of cables may be used with suitable resistance taps made to tracks at various places. MAINTENANCE The practical electrolysis problem is due to stray current from electric railways. Instances of stray direct currents from other sources sometimes occur, but such cases are not specifically considered in this report. Currents straying to earth from electric railway tracks frequently find their way to water and gas pipes, telephone and power cables, and other underground structures. When this current leaves these structures through earth, corrosion results. Thus not only are the structures of many different companies subject to injury, but by reason of the different public services dependent on such structures, the public as a whole has a direct interest in this type of electrical interference. The problem, therefore, is one which is preeminently adapted to cooperative treatment. In many cities it has been found advantageous to form joint committees, composed of technical representatives of the several utilities concerned, to investigate the local electrolysis situation and determine by agreement a course of procedure to be followed. Such committees should attack the problem in an open and fairminded manner with the object of effecting, in the most economical way, mitigation of all the troubles resulting from the presence of stray currents in the earth, including corrosion, fire and explosion hazards, heating of power cables, and operating losses and difficulties. To this end, they should be composed of men, or have men associated with them, who are trained in the technique of electrolysis. Active committees of the kind described are now existent in Chicago, Kansas City, Omaha, St. Paul, New Haven, Milwaukee, and Syracuse. The principle of cooperation has been recognized by the Railroad Commission of Wisconsin in an order authorizing an Electrolysis Committee in the City of Milwaukee. Such committees act as clearing houses of information and keep all the interested companies informed as to changes in their systems which may affect the electrolysis situation. Under the direction of such a committee joint electrolysis surveys may be conducted and unified methods of mitigation installed and maintained. 24 DESIGN, CONSTRUCTION, OPERATION, ETC. In general, the same factors that determine the amount of stray currents are those that have a direct bearing on the economy of railway operation. A good example is that of an insufficient number of substations, which results both in large stray currents and poor railway economy. Similar results follow from defective bonding, rails of inadequate size, or failure to interconnect tracks. For this reason, it is believed that many existing railway systems can be modified in such a way as to increase their own economy of operation, while at the same time securing important reduction in stray current. Measures of this character, which are essential to the most economic operation of the railway, should be regarded as a prerequisite of the application, either to the railway or to the affected structures, of measures specifically for electrolysis mitigation. or more of the following measures should be taken : (a) Applicable to Railways. (1) Additional substations, (2) Insulated negative feeders, (3) A modified system of power distribution such as a three-wire system. 1. Track Construction and Bonding. (a) Importance of Rail Circuit. Stray current is increased by A [ insufficient rail weights and imperfectly bonded track joints, p While the major portion of the current of a grounded return railway generally returns through the tracks and return feeders to the power station, a portion finds a parallel path through the earth and its buried metallic structures. As the current flowing in each path is inversely proportional to the resistance of that path, it is of prime importance to make the resistance of the track and proper bonding. (b) Rail Bond Resistance and Tests. The contact resistance of the bond terminal connection to the rail may be a considerable part of the resistance of the joint if the bond is not properly installed and maintained and it is therefore essential in selecting the type of bond to be used, that special consideration be given this feature. It is the usual practice to measure the resistance of the bonded joint including three feet of rail in terms of a length of continuous rail. The equivalent length of a properly bonded joint including three feet of rail, varies from 3 to 6 feet, depending upon the size of the rail, and the type, length and cross sectional area of the bonds. On some electrified steam roads it is the practice to bond so that the joint alone will have an equivalent resistance of 20 \|\| inches of continuous rail and to rebond when this resistance " increases to 42 inches. On street railway systems bonding to an equivalent length of 3 to 6 feet is common practice where short .bonds are used, rebonding when the joint resistance including three feet of rail increases to that of 10 feet of rail. A single No. 0000 long bond, installed around the splice plates will have with three feet of rail, a resistance equivalent to from 8 to 15 feet of continuous rail, depending upon the size of the rail. Practice varies widely as to the frequency of testing rail bonds but most railway companies make complete tests of all bonds at least once each year and more frequent tests on tracks subject to excessive traffic or deterioration. Good practice would require annual tests of all bonds, and semi-annual on tracks in which the bond failures exceed five per cent annually. Single or Multiple Stud. There is a further distinction between exposed and concealed bonds, the latter being used where the prevention of theft is a serious consideration, in which case the bonds are installed underneath the splice plates. Local conditions will largely determine the type of bonding to be used. Consideration should be given to the economy of construction, maintenance, costs, facilities for using bonding equipment, tools, etc. In recent years there has been a marked tendency toward the more general use of all types of welded bonds with almost complete abandonment of soldered bonds and those mechanically applied to the head of the rail. Pin-terminal and compressed-terminal bonds are still extensively used for application to the web of the rail but even here the welded type is finding favor with many companies. One reason for the increasing use of oxy-acetylene and electric alloy welded bonds is to be found in the lighter, cheaper, and more portable tools for their application, some of the newer methods and apparatus which have been developed for this class of work being far superior to those formerly employed. Soldered Bonds are applied to the head, base or web of the rail by means of solder, a blow torch being used to heat the rail" to a soldering temperature. The difficulty of securing a permanent and low resistance contact has caused practically all railway companies to abandon this type of bond. gas flame. . The Resistance Weld of bond to rail is accomplished by clamping a carbon block against the head of the bond and heating this block to a high temperature by the passage of a large electric current or by drawing an arc on the face of the block. In the Electric Arc process the arc is drawn directly on the rail and bond terminal. In both the resistance and arc methods of welding or brazing the rail and bond terminals are brought to a welding or brazing heat and united in a solid mass by filling in metal, thus forming a mechanical and electrical union. The filling in metal may be a copper or iron wire used as an electrode. When the bond terminal is steel, the latter metal is used. Several methods, differing somewhat in the equipment used and the methods of applying the heat to the bond and rail, are in use, and the selection of the most suitable of these will depend upon a number of factors and often upon local conditions. flame from a blow torch. These methods give a connection of low resistance and short t\ bonds can be applied to the head of the rail without much danger \ \ of theft due to the small amount of copper involved and the tenacious contact between bond and rail. Pin Expanded Terminal Bonds have a hole in each terminal through which a tapered drift pin is driven to expand it into a hole drilled in the web of the rail after which a pin, slightly larger than the drift pin, is driven into the hole and left there to prevent contraction. This type of bond requires great care and accuracy in manufacture and in installation, but when properly installed makes a very efficient and satisfactory construction. The essential features are a carefully and accurately milled terminal and a perfectly clean, circular-drilled hole, reamed to proper diameter, in the rail. Care should be used to brighten the terminal with emery paper just before installing and to avoid contact with the fingers which will cause corrosion between the terminal and the rail. Holes should be drilled dry and bonding should not be done except in fair weather so there will be no moisture to induce corrosion. This type of bond is usually applied to the web of the rail. As it requires only small portable tools it has been found to be particularly well adapted to main line tracks under operating conditions. Compressed Terminal Bonds are of two kinds, one being a single solid terminal bond applied to the web of the rail in a manner similar to the Pin Expanded Terminal bonds described above except that contact with the rail is secured by means of a heavy screw or hydraulic compressor applied to each end of the terminal, causing it to compress longitudinally and expand laterally, bringing the copper into firm contact with the steel. The screw compressors used for compressed terminal bonds are objectionable where fast traffic is maintained on the tracks as they clamp over the head of the rail, making a dangerous condition due to the possibility of causing derailment. The other is a single or multiple stud terminal bond applied to the head of the rail, the terminal studs being set in holes and expanded into contact by hammer blows. This type of bond has been largely superseded by the modern types of brazed- and welded head bonds. (d) Welded Rail Joints. The difficulties and uncertainties attending the proper maintenance of rail joints and bonds have been eliminated to a large degree by the successful use of several modern types of welded joints, such as electric resistance and arc welding, cast welding, and thermit welding. The welded joint in one form or another has been adopted as a standard of construction in nearly every large city in the United States. Most types of welded joints have a conductivity equal to or greater than the continuous rail and are less subject to failure than any form of rail bond. They must be considered, therefore as a most important factor in the reduction of stray current. Electric Rail Welding is performed by clamping heavy iron bars to the web of the rail and bringing the bars and the adjacent rail to a white heat by means of an electric current. The process requires a heavy and expensive plant and is usually carried out by contract on a comparatively large scale. For this reason it is not well suited to installations on small systems. It is well adapted to the reclaiming of old track as well as for new work and has been applied on open T-rail construction where expansion joints are installed at intervals to provide for expansion and contraction. Arc Welding. There are several forms of arc welding where the splice bars are welded to the rail at a number of points by the use of an electric arc. Electric arc welding may be done under traffic conditions and is more extensively used in maintenance work than other methods. Cast Welding is accomplished by setting a mould around the rail joint and pouring molten iron from a crucible around the joint. This process requires transporting a portable cupola along the street adjacent to the work. On account of the improvement in similar types of joints with more portable equipment, this method is not now used as much as formerly. aluminum, which is ignited in a crucible. Cast welding is used chiefly on new construction and cannot be done under traffic. The renewal of a cast weld joint requires cutting in a short length of new rail which adds another joint to the track. (e) Cross-bonding. The important objects of cross-bonding are to equalize the current flow between the rails, thus reducing the voltage drop and also to insure continuity of the return circuit in case of a broken length of rail or a broken bond in any rail. It is good practice to place cross-bonds at intervals of 1,000 to 2,000 feet on suburban railways and not to exceed 500 feet on urban railways. Cross-bonding between parallel tracks is in some cases installed with the same frequency as between .the rails of the single track; in other cases at less frequent intervals. Some companies make a practice of installing cross-bonds under each feeder tap to the trolley wire or at every fourth or fifth span wire, thus enabling them to conveniently preserve a record of their locations. In cases where the track has been carefully insulated cross-bonds should preferably be rubber insulated so as to increase their electrical resistance to earth, and where subject to damage from track tools and to other mechanical injury the insulation should be protected by circular loom or conduit. The common practice of electrified steam railroads is to use cross-bonds with a conductance equal to one track rail, or of about 1,000,000 circular mils cross-section. Street and interurban railways employ bonds having a cross-section of from 200,000 to 500,000 circular mils. (f) Special Track Work Bonding. It is good practice to provide jumpers at switches, frogs and at other special track work to insure that the electrical continuity of the bonded rail will be maintained. This is usually accomplished by jumpers extending around the special work, and in such cases the frogs are bonded into the track system, or where practicable the special work is bonded as other track rails. The size of the jumper cables to be used will depend upon the nature of the traffic. On tracks bearing heavy traffic a separate cable is usually provided for each rail, while for light traffic a single jumper connecting to all rails on both sides of the special work is sometimes used. In all cases the jumpers should be proportioned to the current carried in the track and in no case less than a No. 0000 for one track. In cases where the track has been carefully insulated the best practice provides for the use of insulated cables for jumpers, except in dry locations, as for instance, on bridges or on other elevated structures where the ties are not in contact with earth or ballast. The electrical leakage from one bare track juniper to damp earth has been known to offset the effect of many miles of most careful track insulation. Under such conditions, if positive to the earth, the bond is gradually destroyed by electrolysis. (g) Bonding Tracks with Signal Systems. In determining the location of cross-bonds and jumpers in connection with alternating current track signal circuits, a departure from ideal spacing becomes necessary, owing to the fact that cross-bonds are permissible only at the reactance bonds. The signal reactance bonds are located between the signal block sections, and these sections are more or less fixed for train operating conditions. The method used where tracks carry heavy currents is to crossbond at all signal reactance bonds and install additional crossbonds with reactance bonds at intermediate locations to obtain the most satisfactory resistance conditions in the sections fixed by the signal system. (h) Conductivity and Composition of Rails. The conductivity of the track rails used by several interurban and electrified steam railroads has been found to be equivalent to about Jfi that of copper, and this figure generally holds approximately true for girder types of rails, except when alloy steel is used, in which case higher resistivities are found. The track rails are specified for their mechanical qualities, and where these interfere with the electrical requirements, it is customary to give the mechanical qualities preference. The composition of rails for heavy service used by one of the large electrified steam railroads, in percentage, is as follows : 2. Track Insulation. (a) Degrees of Insulation. Under this sub-heading have been considered, (1) Substantial Insulation, in which the type of construction largely prevents the escape of stray current, and (2) Partial Insulation, which comprises using such means as are available to insulate from the earth the running rails of ordinary street railways insofar as practicable. Substantial Insulation. Interurban and electrified steam roads generally require the rail to be supported on wooden ties set in well drained broken stone or gravel ballast. Such construction affords a very high resistance between the tracks and earth and reduces the danger of electrolysis to a minimum. With 10 volts between rail and ground the leakage in some instances is found to be as low as 0.00016 amperes per rail per tie under dry weather conditions, increasing to 0.0055 amperes when wet. On double track with ties spaced 2 feet apart these values represent 0.32 and 11.0 amperes, respectively, per 1,000 feet, or 31 and 0.91 ohms respectively for 1,000 feet. On steel structures where the ties are only partially in contact with the ground and cannot become waterlogged, this leakage is even less. The substantial insulation of a ballasted roadbed has, in some installations, been rendered ineffective by bare negative cables in damp earth or by metallic connections between the tracks and steel supporting structures. Conditions are found to be very favorable for rail insulation where the tracks are in subways or under cover protected from the weather, permitting the ballast and ties to become permanently dry. Partial Insulation. Tracks placed in city streets where rails are depressed to the surface of the ground and have only their upper surface exposed can be but partially insulated. The character of the material in immediate contact with the rails has a large influence on the resistance to ground, but it has been repeatedly demonstrated that coating the rails with an insulating material is not advisable, and the best plan is to provide a roadbed, which, taken as a whole, is of an insulating character. The use of well drained broken stone or gravel ballast results not only in a good roadbed, but also affords a much higher resistance to the escape of stray current than does a roadbed of concrete. It is desirable to keep vegetation down and otherwise keep the ballast dry and prevent foreign material from washing into it. Salt, which is frequently used to prevent freezing at switches and thereby facilitates the escape of stray current. Electric railways have experienced some damage due to the corrosion of the base of the rail or of elevated structures connected to the rails in districts where the stray current leaves the structure for the earth. Cases are on record where this corrosion is serious and where steps have been taken to reduce the damage to elevated structures by insulating the rail from the steel structure. Any measure which tends to insulate the track from the soil or any mitigative system which tends to reduce stray current will tend to retard the electrolytic corrosion of the base of the rails and other grounded steel structures. (b) Leakage to be Expected. Under conditions of substantial insulation and where the roadbed is of open construction the leakage varies widely depending upon the character of the ballast and whether it is wet or dry. In dry weather the resistance may be from 10 to 15 ohms or even more per 1,000 feet of single track. In wet weather this may drop to 3 to 5 ohms. If ties are treated with a 3 to 1 mixture of gas oil and creosote, the resistance may be double the above values whereas with ties treated with zinc chloride or other chemical salts the resistance may be one-half of these values. The leakage where tracks are only partially insulated will not only be much greater than where they are substantially insulated but will vary over a much wider range. This is because the type of roadbed, character of soil, and drainage conditions vary greatly. It is known that well drained crushed stone ballast with a Tarvia finish will have a resistance from 2 ohms to 5 ohms per 1 ,000 feet of single track. On the other hand the resistance of roadbeds with solid concrete ballast in contact with the rails and also earth roadbeds, in which the ties are embedded and therefore in a more or less moist condition, are much lower and may be only from 0.5 to 1.5 ohms for 1,000 feet of single track. 3. Reinforcement of RaiL Conductivity. Early track construction practice in this country often included bare wire laid between the rails and connected to each bond. Sometimes one such wire was used for each rail, sometimes one for each track, and sometimes one served for a double track. The wires varied from No. 4 to No. 1, and were either of copper or galvanized iron. Their conductivity was small and they were subject to electrolytic corrosion and mechanical injury. This construction has practically gone out of use. It is, however, common to find the rails in the vicinity of supply stations supplemented by large conductors connected in parallel with the rails. This is not infrequently accomplished by the use of bare copper wire or cable buried between rails, and hence in full contact with the earth. Old rails, bolted and bonded together and buried beneath or beside the track, have also been used in some cases. Such buried conductors increase the leakage from the tracks and should be avoided. Supplementary conductors in parallel with the track and connected to it at frequent intervals tend greatly to insure the continuity of the return circuit, where the track bonds cannot be well maintained. Where copper cables are so used the occasional failure of bonds does not materially affect the track drop and their use may be justified where tracks are laid on filled or spongy ground or where the proper maintenance is unusually difficult. Buried bare conductors, however, increase the contact area between the return circuit and the earth, and the tendency to augment stray currents thus caused offsets to a greater or less extent the benefits attained by the reduction of drop. Copper installed in this manner is in parallel with the rails, and therefore has the same drop as exists in the rails. As track gradients rarely exceed two or three volts per thousand feet, this would mean that the drop on such cables would not exceed two or three volts per thousand feet, which corresponds to a current density of about 190 or 280 amperes respectively, per 1,000,000 circular mils. It will be seen that these densities are so low that such use of the copper is very uneconomical and for this reason this method of reinforcement of the rail conductivity should not ordinarily be used. Conductors are regarded as being in parallel with the rails when both ends are connected to the tracks or when one end is connected to the track and the other to a station busbar which is connected directly to the rail by a conductor of negligible resistance. The use of such conductors should not be confused with the insulated negative feeder system. 4. Power Supply. Among the various features of railway construction which tend to reduce stray current none has made more rapid advancement during recent years than the development of multiple feeding points, principally from use of additional substations supplying the railway systems. Increasing the number of .substations will reduce the feeding distances and effect a saving in distribution copper and in line and return losses, and will also reduce the amount of current to be returned to any one point. The general effect is to reduce the track voltage drops, thereby reducing the amount of current which will stray from the rails to subsurface metallic structures. If The ordinary street railway system employs direct current ( at from 550 to 750 volts. Some interurban lines operate at 1200 volts direct current and voltages as high as 3000 volts are used on the electrified sections of some railroads. (a) High Voltage D. C. Railways. Railway systems of higher potentials than the ordinary 550-750 volt systems may cause more or may cause less stray currents than the latter, depending upon conditions. With the same -spacing of substations the current will be less in proportion as the voltage is greater. Usually, however, advantage is taken of the higher potential to locate the power supply stations farther apart, maintaining approximately the same current density in the tracks with the usual jj voltage drops which tend to increase the stray currents. In making comparison of high voltage and low voltage systems from an electrolysis standpoint, the difference in conditions must be taken into account. As a rule high voltage direct current is used principally on roads having a private right-of-way with rails on ties supported on well drained rock ballast. Moreover, the major portion of such lines are located in country districts with no buried metallic structures paralleling them, but in some cases such lines pass through cities or towns, or at least enter their suburbs, in which event suitable measures to prevent injury by electrolysis should be taken. (b) Source of Stray Currents. A single trolley electric railway system with an adjacent buried pipe line is illustrated in Fig. 1, in which the underground network of pipes is represented by a pipe parallel to the tracks. At points remote from the power supply station, the current which reaches the rails from the cars will divide between the several possible paths, and the amount flowing along any path will be inversely proportional to the resistance of that path. A portion of the current, therefore, will leave the rails at points remote from the station and pass through the earth to the adjacent pipes, then flow along the pipes toward the station, leaving the pipes near the station and returning through the earth to the rails and thence to the station as indicated by the arrows in Fig. 1 . The region near the station where the pipes are positive to the surrounding earth, and where the current leaves the pipes to return to the rails, is the region where damage by electrolysis will occur, and is called the danger or positive area. Fig. 2. If the cars are uniformly distributed along the line, and if the track is of uniform resistance throughout its length, the voltage profile along the track will be as shown in Fig. 2. This curve is a parabola with a vertical axis and with its apex at the end of the line. The potential drop from the end of the line to any point on the line is therefore proportional to the square of the distance from the end of the line. The slope of this curve is a measure of the potential gradient. If the resistance of the track is^known, seen to be negative to the rails and near* the station they are positive to the rails. Ordinarily the positive area extends from 30 to 40 per cent of the distance from the supply station to the end of the line. At the neutral point where no potential difference exists between the pipes and the earth the stray current in the earth and underground structures is a maximum. overall voltage drop than of the potential gradient at any point. While high potential gradients extending over a considerable length of track will result in a high overall voltage with correspondingly large stray currents, the existence of a high gradient on a comparatively short section of track is of much less consequence. The reduction of feeding distances and overall potentials has such a marked influence on stray currents that a rather full treatment of this subject is here given. (c). Relation of Feeding Distance to Stray Currents and Overall Voltages. The effects of the reduction of feeding distances on stray currents and overall potential drops are illustrated in Figs. 4 and 5. The stray current curves are calculated from the formulas found in Technologic Paper No. 63 of the Bureau of Standards, entitled "Leakage Currents from Electric Railways." They represent conditions on a typical line having the following characteristics: Double track, 72-lb. rails; length of line, 20,000 feet; calculated resistance of the track, 0.004 ohm per 1,000 feet (this figure allows for a 10 per cent increase in the resistance of 72 Ib. rails, due to the bonds; it corresponds approximately to the resistance of 2.5 million circular mils of copper). The leakage resistance is taken as 0.4 ohm for 1,000 feet, of double track which is a fair average for city tracks in paved streets with a crushed stone foundation. An average load of 40 amperes per 1,000 feet, corresponding to a headway of 4 minutes each way, is considered uniformly distributed along the line. The total average load is, therefore, 800 amperes, corresponding to a station capacity of 1,000 kw., on the assumption that the peak load is double the average load. Calculations of stray current have been made for both the insulated bus and the grounded bus conditions. This latter occurs only when all of the stray current returns to the negative bus without re-entering the track system, a condition which does not ordinarily occur in practice. An approach to a grounded bus would be a system where extensive pipe drainage existed with a large portion of the current returning to the bus from the underground piping and cable systems. Another condition which simulates a grounded bus is often found where bare copper cables which are used to connect the negative bus with the nearby rails are permitted to come in contact with wet earth or are laid in a stream or river bed. Railway stations generating direct current are often located in low ground or on rivers where condensing water is available and unless special precautions are taken to insulate negative cables entering such stations they are likely to pickup considerable current from the earth, thereby establishing the condition of a semi-grounded bus. Fig. 4 shows the total current returning to a single supply station located at the end of the line. The stray current at any point is also shown for the cases of the bus grounded and the bus not grounded. By insulating the bus the maximum value of the stray current is reduced from 417 amperes to 147 amperes and by putting the supply station at the middle of the line instead of at the end and thereby reducing the feeding distance to one-half, the maximum at one-fourth and three-fourths of the distance to the end of the line respectively. Shortening the feeding distance to one-half reduces the overall voltage to one-fourth of the original value and cutting the feeding distance to one-fourth reduces the overall voltage to one-sixteenth of the original value; or as previously stated, the overall voltage varies as the square of the feeding distance. The curves in Fig. 5 are based on theoretical conditions with no stray current. The actual overall voltages would be somewhat less because of part of the current being in the earth. The dotted lines in Fig. 5 illustrate in a 'general way the potential of the earth and pipes under the several conditions of feeding and the shaded portions represent the areas where the earth and pipes are positive to the rails The effect of providing additional centers of power supply can also be illustrated by the curves in Fig 6, which, while calculated on the assumption of no stray current, illustrate in a simple case, the effects which have been observed in practice. The curve SAO represents the track voltage drop on a portion of an electric railway system having a uniformly distributed load. The curve SBF illustrates the condition of a substation located at P, 33 per cent of the distance from Q to S, carrying 20 per cent of the total load. In this curve the portion BF is identical with AO. As the load is uniformly distributed, 33 per cent of the load is on the portion of the line shown by PQ, and of this 33 per cent, 20 per cent is carried by the substation P. The remainder, or 13 per cent, is carried by the station S. The point B on the curve SBF, therefore, corresponds to the point N on the curve SAO, the distance QR being 13 per cent of QS. In the same manner the curves SCG, SDH, and SEK are drawn showing the conditions when the station P carries 40 per cent, 60 per cent, and 80 per cent, respectively, of the total load. The summit of the curve SMD, in which the station P carries 60 per cent of the load, is located so that PL equals 60 per cent minus 33 per cent, or 27 per cent of the total length SQ to the left of P. The distance QL is, therefore, 60 per cent of the total length QS. In general, the conditions are more complicated than those here assumed, and will ordinarily prevent an accurate determination of the relative potentials of the negative buses of the two stations. (d) Economic Considerations Invoked in Additional Supply Stations. The practical limit of feeding distances is one that cannot be determined by any general formula designed to fit all conditions. The economic aspects of the problem are far more complex than they appear at first glance and the proper solution involves a careful study of local conditions. However, an increase in the number of power supply stations may be said generally to reduce stray currents to a marked degree and with the advent of automatic control for railway substations the increase in the number of feeding points economically obtainable by this means should result in greatly improved electrolysis conditions. ture, but with no increase in annual charges. Also, the original equipment may be distributed to additional stations with little or no capital expenditure, due to saving of feeder copper, and with no increase in annual charges. The curves in Fig. 7 show the results of calculations on a typical interurban railway system. They are based on the data contained in the paper by H. F. Parshall presented to the (British) prices of copper and electrical machinery and labor. Ordinarily in laying out the number of substations for a given electric railway system, the minimum number consistent with economy will be the number selected, such as represented by the curve for manual operation at A. With the growth of traffic the number of stations in operation becomes increasingly inadequate until a condition is reached represented by the point B on the curve, when additional substations are again added. In other words it is customary to operate along the curve from A to B with an insufficient number of substations. It appears, however, that by operating between C and A on the curve instead of between A to B an increase of about 40 per cent in the number of substations can be made without effect on the total annual charges. It has been shown on page 40 of this report that when the overall voltage is divided by 4 the amount of stray current will be about one-sixth for the particular conditions discussed. An increase of 40 per cent in the number of substations will decrease the overall voltage to about one-half of the former value and therefore reduce the stray current to about one-third. It appears, therefore, that by selecting the maximum number of substations consistent with economy instead of the minimum number, the railway companies could reduce to a large extent the stray currents without appreciably affecting their total annual charges and this method should be considered as one of the best possible solutions of the electrolysis problem. The curve for automatic substations is even flatter than that for manually operated stations, indicating that a very large increase in the number of automatic stations beyond the point of maximum economy may be employed without materially increasing the annual charge. It appears from these curves that if, while the electric railway companies are increasing their power supply, they will at the same time increase the number of power supply stations to the maximum economical number, then they can without any increase in the total annual charges eliminate the greater portion of the stray currents which cause electrolysis. In many situations the combination of railway substations with light and power substations may offer additional opportunities for economically providing points of supply without additional expense for buildings and attendance. service. Automatic stations were first used on interurban lines having infrequent service and the installation usually consisted of a 300 or 500 kw. machine. When a car or train of cars approaches one of these interurban substations the voltage of the trolley falls and when it has reached a certain point the substation automatically starts up and carries the load while the train is in its vicinity. As the car recedes from the substation the demand for current decreases and when the load has reached a predetermined minimum the substation shuts down. This type of substation with small converters has been successfully introduced in some cities, the most notable installation being that at Des Moines, Iowa, where six substations were distributed throughout the city to replace one centrally located power supply station. The characteristics of large city loads are different from those on interurban lines. The movement of a single car produces but slight fall in the trolley potential and the starting and stopping of the substation is governed by the demand for power during the morning and evening rush hours. A few substations with large converters have been provided for such city service and are now in experimental operation. Remote control substations are also being developed for city service where they are required to operate continuously throughout the load period of the day or during the morning and evening peaks. Semi-automatic equipment, consisting of re-closing circuit breakers, time switches, and protective devices have been installed in a number of railway substations at a very much smaller cost than would be required for full automatic operation. The circuit breakers in the positive feeders automatically re-close after a definite time interval provided the short circuit or overload has been removed. The synchronous converter has to be started by hand and may be shut down either by a time switch or by hand. Otherwise it operates in a manner similar to those provided with full automatic control. The first cost of automatic substations is often justified by the saving in operating labor an_d feeder losses and the recovery of existing feeding copper. Minor savings arise from the elimination of light load losses and the station heating. A further benefit also to be derived from their general use is better voltage conditions and therefore faster car schedules. The total amount of substation equipment now operated automatically is in excess of 50,000 kw., and much of the equipment being installed is intended for automatic operation or remote control. The increased savings attending this development will undoubtedly increase the number of substations which can economically be installed on both interurban and city systems, and if full advantage is taken of these economics, the feeding distances will be reduced to such an extent as to greatly reduce stray currents generally. ( f ) Location of Supply Stations. As pipes and other underground structures become increasingly positive to the earth as they approach street railway supply stations or the low potential points on the track system, it is obvious that if stations were located away from pipe networks trouble from electrolysis would seldom occur. As a rule other considerations will determine the location of supply stations in cities. However, on interurban lines the protection of piping systems in small towns against electrolytic corrosion often presents a grave problem because of the long feeding distances and the difficulty of employing the measures of mitigation ordinarily used in city systems. Under such conditions the location of the supply station at a distance from the city and away from the underground structures may be the most satisfactory way of insuring their protection. This is particularly true of automatic substations which require no regular attendants. The character of the earth in the vicinity of supply stations naturally has an important effect on the magnitude of stray currents. It is, therefore, desirable to avoid connecting negative feeders to tracks in unusually wet locations. (g) Alternating Current Systems. When the first alternating current railways were proposed, the question of possible electrolytic effects received special investigation. Considerable work was done upon a laboratory scale, in which it was established that alternating currents could produce corrosion on electrodes of the metals commonly used underground, such as lead and iron, but that the effects were very much less in magnitude than those produced by equivalent direct currents, usually less than one per cent and in most cases negligible. See Fig. 16. The objections to the substitution of alternating current for direct current in the case of systems already installed in large cities are so well known and so serious that the question needs no discussion. 5. Interconnection of Tracks. Electrical interconnection between parallel tracks in close proximity, or of tracks, one of which passes over the other, belonging to the same or different railway systems is usually a necessity in order to prevent wide fluctuations of voltage between the tracks. Such interconnections tend to equalize the potentials of the tracks so connected and thus tend to prevent the flow of current from the track of high potential through earth and intervening metallic subsurface structures to the track of low potential. In general such interconnections also afford a saving in track losses. Whether parallel tracks should be connected naturally depends upon the distance between tracks, location of supply stations, leakage characteristics of the roadbeds and other local considerations. Interconnection generally reduces the track voltage drop by providing more metallic paths for the current. It has also the same general effect as cross-bonding between rails of the same tracks, in that if one track circuit should be accidentally opened the current would be shunted around through the interconnection to the other track. As a rule interconnection of tracks will improve electrolysis conditions but may be detrimental to one locality while improving conditions in another. A failure of one of the companies to maintain its bonding would naturally tend to increase the current on the better bonded track. Interconnection of tracks has been found to be particularly advantageous where two or more lines of electric railways operating in one locality and belonging to the same or to different systems are supplied from two or more power stations located in different parts of the city. By interconnecting the tracks of such lines in the neighborhood of the power stations and also at several intermediate points a reduction in the resistance of the return circuit can be brought about whereby the drop formerly existing in one track can be balanced by the drop in the opposite direction in the other track. The rail drop in each track is greatly reduced and all high potential gradients between tracks eliminated. Where the tracks of the two independent railway systems are parallel and a short distance apart, and fed by power supply stations in opposite directions the potential profiles of the rails will be as shown in Fig. 8 in which, for simplicity, the negative buses at the two stations have been assumed to be at the same potential. In the figure are also indicated the potential profiles of the pipes adjacent and parallel to the two sets of tracks. If then gas or water pipes extending from the parallel mains cross under two sets of tracks at different locations where the tracks are at a considerable difference of potential, as at RB, Fig. 8, then the pipes may be negative to one track and positive to the electrolysis will be liable to occur. If now the rails of the two systems are interconnected at points near the two stations and also at intermediate points the potential profile along the rails after such interconnection will be as shown by the curve OYP. It will be noted that this interconnection results in a very considerable reduction of the potential drop in the return circuit, and the resulting reduction in the losses will in many cases be alone sufficient to warrant the cost of the interconnections. Railway systems employing track circuit signals must insulate their rails used for signal circuits from other systems in order that other currents may not be introduced in the signal circuits and for this reason cannot avail themselves of the advantages of interconnection. This applies only to rails used for signal circuits. 1. Insulated Negative Feeder System. Of the various methods of railway construction and operation employed to improve electrolysis conditions, the insulated negative feeder system has been most widely used. While it has been generally thought that such a system is necessary in connection with a large supply station if underground structures are to receive adequate protection, the present tendency to greatly increase the number of railway supply stations, and particularly the development of the automatic substation makes the extensive use of insulated negative feeders less important. An increase in the number of track drainage points is often more economically attained by the use of more substations than by the use of insulated negative feeders. The tendency is now in the direction of a relatively few short insulated negative feeders and a large number of substations, rather than an extensive use of insulated feeders from a few large supply stations. (a) Description. In the insulated negative feeder system, instead of tying the tracks directly to the negative bus and depending on the tracks and such copper conductors as may be in parallel with them to return the current to the supply station, the connection at the station is either removed or a suitable resistance is inserted and insulated feeders are run from the bus to various points on the track. By thus taking the current from the rails at numerous points, high current densities, and consequently high gradients and overall voltages, can be avoided to any desired degree. As the feeders are entirely insulated from the earth except at points of connection to the tracks, the actual drop in potential in the different feeders is of no importance so far as electrolysis is concerned, so long as the drop is approximately the same in all feeders. It is possible, therefore, to impose any limiting value of overall-track drops and track potential gradients on the track and still be free to design the feeders to give maximum economy which is not possible when the feeders are connected in parallel with the track. Insulated feeders are sometimes designed for equal potential drops, in which case the several points of connection to the tracks are at the same potential and the system is called an equi-potential or balanced system. When the shorter feeders are designed for a lower drop than the longer feeders, the system is called a graded potential system. Fig. 9 shows the overall voltage curves representing conditions on a track which is connected directly to the negative bus and with which no additional feeders are employed. The curves are parabolas with the same constants as those in Figs. 2 and 5. Fig. 10 illustrates the same system with insulated negative feeders extended to four points on the track, two in each direction, with a resistor connected to the nearest point on the track. The feeders and resistance are so proportioned that the drop on all is the same under average load conditions and they, therefore, form an equi-potential system. The curved lines represent the potential of the track from point to point, and, as in Fig. 9, the curves are arcs of parabolas. An equi-potential system of this kind, while it reduces potential differences on the tracks to a minimum and therefore affords the maximum reduction of stray current, usually involves increased energy losses in the return circuit as the rails are merely used as distributing mains for the feeders and are not taken advantage of to return current to the supply station. The equi-potential principle is better adapted to a city network than to a single line, as feeders can be extended to several points on the network at approximately the same distance from the station, and these points can thus be maintained at the same potential. As a rule, however, a gradient is permitted between the points so selected and the track at its nearest approach to the supply station. An arrangement approaching an equi-potential system is shown in Fig. 1 1 , where four feeders are connected to the track at important intersections and connection made to the track near the station through a resistance. One of the feeders is shown connected to^ the track at two points, a resistance being inserted at the point nearest the station. equivalent, in the reduction of stray currents, to independent substations at the several points where the current is removed from the track; that is, the results, so far as voltage drop on the tracks is concerned, is the same whether a number of stations or an equal number of insulated negative feeders be employed, but the energy losses in both the positive and negative conductors are very much greater with the negative feeder system than with the same number of substations. Fig. 12 illustrates an insulated negative feeder system so designed that the direction of the current in the rails is not reversed as in the equi-potential system. This graded potential system results in a slightly higher potential at the terminal of each succeeding feeder, starting from the station, and these higher potentials on the longer feeders result in higher overall track potentials than with the equi-potential system, but allow a material saving in copper in the negative conductors. In designing graded potential feeder systems, it is customary to limit the gradients on the tracks to some definite amount, such, for example, as an average value of 0.5 volt per 1000 feet and to remove all of the current from the track over an insulated feeder wherever this limiting gradient is reached. By removing no more current at any point than has accumulated up to that point, the current in the track is nowhere reversed and a continuous gradient toward the station is maintained as illustrated in Fig. 12. (b) Application of Insulated Negative Feeders. No definite rules can be laid down regarding when and to what extent insulated negative feeders should be used. In city networks the negative bus should generally be connected to the track at more than one point, that is, negative feeders should be extended along the tracks to nearby intersections. Small stations of 300 to 500 k.w. capacity in city networks may usually be connected directly to the track at one point only and preferably to the nearest track intersection. Insulated negative feeders should be run from the negative bus to the rails in such a manner as to insulate them thoroughly from the earth and from each other. The tying together of any of these feeders should be avoided. In some cases, however, it may be allowable to tie a single feeder to the rail at two or more points through resistances to adjust the currents drawn from the tracks at the various points of connection. should therefore be avoided where possible. Means should be provided on all negative feeders and feeder taps for conveniently measuring the current flow thereon, and where practicable these means should be installed within the railway power station. Application to Interurban Lines. In the case of a single line, little is to be gained by the use of insulated negative feeders unless they are run considerable distances from the power supply station. For this reason they are not as well adapted to reducing stray currents from interurban lines as from city networks as the following explanation will show. It has been shown in the section on Power Supply that stray current results from the action of large overall voltages rather than from high potential gradients. Large overall voltages may be produced either by concentrated city loads over relatively short feeding distances or by comparatively light loads on long lines. The former condition can often be effectively dealt with by the use of insulated feeders because of the short distances involved and a traffic of sufficient density to justify such an expenditure. A very different condition exists on interurban lines where a corresponding reduction in overall voltages would require very long insulated feeders entailing large expenditures for copper and large power losses. The effect of installing insulated negative feeders within the limits of a small town through which an interurban lines passes is illustrated in Fig. 13. Without the use of negative feeders, that part of the piping system within the city limits is shown to be positive to the tracks, a condition which is often found in practice, although not a reliable criterion as to the degree of hazard to underground structures as pipes are sometimes positive to the rails and negative to the adjacent earth. If the potential gradients on the tracks within the city are reduced or eliminated by the use of insulated feeders, the overall voltages are only slightly affected and the potential difference between the pipes and tracks not greatly reduced. In some instances where insulated feeders have been applied on interurban lines, the positive area has actually been extended and no material improvement in the general condition effected. It is not the intention here to condemn entirely the use of insulated^negative feeders for interurban electric lines, because in some cases they have been successfully used. Local conditions vary widely and each problem should, therefore, be worked out on its own merits. However, it can safely be said that this method of electrolysis mitigation is not so well adapted to interurban lines as to city systems. (c) Negative Boosters. Negative boosters are sometimes used in connection with the insulated negative feeder system abroad, but not in this country, so far as known. Unusually long feeders which would have to be very heavy in order to keep the voltage drop comparable with that on the other feeders can be reduced to the minimum size that will carry the current if provided with a booster. When so used, the booster permits a saving in copper but involves an additional energy loss on the conductor. Boosters can also be used to equalize the voltage drops on feeders of different lengths. They have proved economical under certain conditions and uneconomical under others. In general it is simply a question of the fixed charges on copper as against the fixed charges and operating cost of machines. (a) Description. This method of power distribution is similar to that commonly used for city light and power, and known as the Edison three- wire system. It may take two different forms which are the same in principle, but which differ radically in the arrangement of the feeder system. One of these, known as the parallel three- wire system, is directly analogous to the ordinary three-wire power and lighting system. The typical arrangement for the case of a double-track line using this system is shown in Fig. 14. Here one trolley is negative and the other positive, the tracks being the neutral conductor. This results in a potential difference between trolley wires equal to twice the operating voltage at points of connection between the trolley sections. It is evident that only the difference in the load on the two sides of the line returns to the powerhouse on the track, although there may at times be heavy circulating currents flowing between cars in short sections of track. If the cars run at frequent intervals, however, such circulating currents will not have to flow over sufficiently great distances in the tracks to cause nearly as large track drops as would occur with the same loads under two-wire operation. The result would be that where load conditions are reasonably favorable for the three- wire system, large reductions in potential drops in the negative return could be secured. with the parallel three-wire system, the difficulty of properly insulating the two trolley wires from each other, especially at crossings and switches, has been considered so great that the sectionalized three-wire system is considered the more practicable and has therefore been employed in all installations which have come to our attention. It is shown diagrammatically in Fig. 15. In this form the feeding district is divided into sections, and alternate sections are supplied by feeders running from the positive bus, while the remaining sections are supplied by feeders from the negative bus, the difference of potential between the two buses being approximately 1,200 volts. In this way, the existence on the same portion of the street of two trolleys having a high difference of potential between them is avoided. The tracks, as before, serve as the neutral conductor and convey the current from the cars in one section to those in the adjoining section and return the unbalanced current to the powerhouse. (b) Insulation of Trolley Sections. The problem of insulating the positive and negative trolley sections from each other is one that will require considerable care. At points of simple juncture this has been accomplished in some cities by the use of two standard 600-volt trolley section insulators in series, with a dead section of trolley wire from 4 to 6 feet in length between them. In other cities the two section insulators are brought together, thereby simplifying the overhead construction. It is also possible to use a single 1,200- volt section insulator 18 to 24 inches long. Where trolley wires of opposite polarity cross, it will probably be found better to make the entire intersection of one polarity rather than try to insulate the crossings. At the intersection of two double-track lines this will mean the installation of four double section insulators as just described. Where such changes are made, the more important of the two lines should be made the continuous one to avoid interruption of service due to failure of power on the other line. Warning signs should be hung on the span wire at all section insulators and motormen should be instructed to coast across these points. (c) Costs. The principal economy resulting from the installation of the three-wire system, is the saving in track losses, which are greatly reduced, although not entirely eliminated, while there usually will be increased station losses due to the necessity of always operating two sets of generators or converters. wire operation is usually, but not always, smaller than the first cost of insulated negative feeders, or any other measure that will give the same degree of protection from electrolysis. The available data on three-wire systems, both as to costs and effects of electrolysis conditions are not sufficient to warrant the laying down of general rules as to the extent of its application. The local factors involved in each case are often peculiar and require special consideration. In cities where uninsulated negative copper has been installed, it may be reclaimed after conversion to three- wire operation, unless it has been installed under pavement or embedded in concrete, and the salvaged copper may largely, if not entirely, cover the cost of conversion. It is good practice to provide an additional bus in the supply station for the generators and feeders operated with reverse polarity. Double throw switches are also installed for these feeders and generators. (d) Difficulties and Limitations. One difficulty which sometimes will be encountered in three-wire operation is that of reduced station capacity, as two or more machines operating in parallel will have a much greater capacity at times of excessive demand than when divided on two independent circuits. Heavy interurban trains, particularly when starting, often demand the full capacity of a supply station and the same condition exists at times of unusual loads, such as occur after a tie-up or following a ball game or circus. Where the generating capacity of both the positive and negative sides of the system is large in comparison to the maximum demand of any trolley section, this objection does does not exist, but where only a single small machine is available for one side of the load, considerable difficulty may be encountered in taking care of the peak demands under extreme conditions. Where necessary these extreme peak demands can be taken care of by operating all of the machines on one polarity during this period. Double throw switches, by which this can quickly and conveniently be accomplished, are usually provided with threewire operation. One instance of an overload with three-wire operation resulted in the too frequent blowing of the circuit breaker on the negative generator. This was eventually overcome by installing a series resistance which is automatically cut into the circuit when the current reaches a predetermined maximum value, thereby limiting the current to a fixed amount. The equipment used for this pur- station control. Not only are unusual loads of short duration difficult to take care of with three- wire operation, but where the entire capacity of a station with all machines in parallel is required to carry the normal peak-load, it may be impractical to convert for threewire operation. In general, it will, of course, be difficult to divide the positive and negative loads in the same ratio as the capacities of the two groups of generators assigned to them. Moreover, the load factor of the whole system is always greater than that of any part, and the generators when divided into groups will therefore be operating at poorer load factors and consequently at lower efficiencies than. when in parallel. Therefore, where no excess generator capacity exists, it may sometimes be necessary to install an additional unit in converting a system for three- wire operation. Owing to the continual movement of cars from one trolley section to another of opposite polarity, there is a considerable variation in the track potential at any point. This is particularly true on lightly loaded lines and results in wide fluctuations, and even reversals, between the tracks and adjacent underground structures. While the algebraic average values of such potential differences may be greatly reduced by the adoption of a three-wire system, a continuously negative condition of underground structures cannot ordinarily be expected. Other difficulties of less importance have been suggested: (1) Some equipment, such for example as arc-headlights, amperehour-meters and auxiliary battery control, requires a single polarity for its successful operation. Where such equipment is used it will be necessary to provide reversing switches. (2) Two trolley poles in parallel cannot be employed on a single car or on trains as they would bridge trolley sections of opposite polarity when moving across section breakers. (3) A negative trolley would change the character of the electric arc used on tracks for arc- welding and building up joints and in some operations might be objectionable. (4) Commercial customers receiving power from trolley feeders may, in some cases, be inconvenienced by a change of polarity. (e) Practicability. None of the difficulties here cited can be considered of insurmountable character, and like many other things, the system can be made to work satisfactorily if the necessary attention is given to it. Experience has fully demonstrated that it will greatly improve electrolysis conditions when properly applied and also give better operating voltage at the cars. However, to secure the best possible results with this system, it will often be necessary to change feeder copper and shift section insulators to obtain the desired sectionalization . (f) Extent oj Adoption, Until recent years the three-wire system has not been employed for street railway work in this country, although it has been in use in Brisbane, Australia, and Nuremberg, Germany, for a number of years. In the last few years it has received some attention in America and is now in operation in Omaha, Wilmington, Winnipeg, Canada, and in some portions of Los Angeles and Milwaukee. The Los Angeles installation has been in operation since 1915 and more recently has been extended to include several additional station districts. In Omaha a trial installation in one station district was made early in 1917. After several months' trial with the experimental installation, the main station district was converted for three-wire operation and has since been so operated. Three-wire operation was adopted in Winnipeg as a means of meeting the requirements of a law passed by the Manitoba Legislature, prescribing certain limitations in track voltage drops. Two substation districts were changed over in 1919, and since that time practically the entire system has been converted to three-wire operation. In 1920, after considerable experimenting, a three-wire system was substantially completed in Wilmington, Delaware, and a complete electrolysis survey made under both two-wire and threewire operation. With the latter, a considerable improvement in car operation due to higher average voltage was reported, and also better electrolysis conditions on water and gas pipes. Stray currents and overall potentials were reduced to about one-half their values with two- wire operation. Reversing potentials were found on the telephone cables in some areas and some adjustment of the drainage of this system will be necessary before it can be said to be entirely satisfactory. 3. Reversed Polarity Trolley System. This method of railway operation involves using the running tracks as the positive conductor instead of the trolley wire. It has at various times been suggested as a means of electrolysis mitigation, and in at least one case it has received an extended trial.. Fundamentally, however, it is not a mitigation method, because it merely reverses the direction of the stray current and in no way affects the magnitude thereof. With reversed polarity the same amount of corrosion will result as with normal operation and the only difference will be the localities in which the damage will occur. Under normal operation using the running tracks as the negative conductor, the electrolytic damage will generally be confined to the area immediately surrounding the direct current power station or the track feeder connection points. With reversed polarity, the electrolytic corrosion will be scattered over the outlying districts which with normal polarity would constitute a negative area. If the trolley system is operated with reversed polarity, it is extremely difficult to effectively drain the lead sheaths of underground cable systems, because there is no definite point of low potential to which to drain. In 1912 the polarity of the electric street railway system in New Haven, Connecticut, was reversed making the running tracks the positive conductor. This method of operation was adopted by the railway company in order to afford immediate relief to the gas works, and to the water and gas piping systems in the central part of New Haven, where very serious damage was occurring. It was then thought that in the outlying sections the damage would be less concentrated, and also failures would be less serious and more easily repaired, than in the central business district. It soon became evident that it was practically impossible to adequately drain the underground telephone cable system, and that even with reversed polarity the general electrolysis conditions of the water and gas piping systems were still far from satisfactory, and after a trial of eight years, this method of operation was abandoned. The New Haven experiment therefore, indicates that the reversal of railway polarity to rails positive is merely a means of relieving dangerous electrolysis conditions in the vicinity of the power station, at the expense of the cable and piping systems at some distance from the station. When no underground cable systotns are involved, reversed polarity is useful as a temporary means of immediate relief to an endangered piping system in the interval immediately preceding the installation of effective electrolysis mitigation. 4. Periodic Reversal of Trolley Polarity. If the polarity of the trolley is reversed daily, at a time when the load on the system is a minimum, few operating difficulties will be encountered and some improvements in electrolysis condi- tions will result. It is obvious that pipes in any locality will be in a positive condition only half as long as with normal operation, and there may also be a further reduction of electrolysis due to redeposition of the corroded metal during the period when the pipes are negative. Laboratory experiments made by the Bureau of Standards, the results of which are shown in Fig. 16, indicate that with a daily reversal of polarity, the corrosion of iron pipes at any point will be about twenty-five per cent as great as will result without such reversals. A similar relation, though not lead when subjected to periodically reversed currents. This method of operation has been employed by the Pacific Electric Railroad Company of Los Angeles, since 1918 in Pomona, Redlands, San Bernardino, Riverside, and Corona. In general it is not applicable to cities where lead cable systems are installed underground, as it would greatly complicate and sometimes render impracticable the drainage of such systems. However, where the cable system is small and confined to the vicinity of the power supply station it may be drained satisfactorily through an automatic switch which permits current to flow from the cables, but automatically prevents the reversal of such flow. Some of the operating difficulties discussed in connection with three-wire systems will be encountered with this system. The operating difficulties attending a more frequent reversal of the trolley potential would be considerably greater, and no attempt so far has been made to do this. 5. Double Contact Conductor Systems. The double overhead trolley system of electric traction as at present used in Cincinnati, and the corresponding underground conduit systems as used in Washington and in parts of New York City, if properly maintained, eliminate the danger of electrolysis. This system has in past years, been strongly urged by some pipe owning companies and engineers who believed it to be the only method by which complete immunity from electrolysis could be obtained. It is now generally recognized, however, that a substantial degree of protection can be obtained by less expensive and objectionable methods and the demand for the double contact conductor system is, therefore, not being pressed at the present time. The chief objections to its use are the cost of installation and the increased operating difficulties which it involves, as well as an unsightly appearance of the streets in the case of the double overhead trolley. The double contact underground system, as used in New York and Washington, not only removes the source of stray current, but requires no overhead wiring or poles and in rare cases may be justified or required for that reason alone. Merely as a means of electrolysis mitigation, the increased cost of the double contact conductor system does not appear to be justified. A. LOCATION WITH RESPECT TO TRACKS In general, the problem of protection from stray currents has to do with conditions under which the affected structures and the tracks are already in place, that is, where their respective locations are fixed. In the great majority of instances, therefore, a discussion of the most favorable relative location of underground structures and rails can have but little more than an academic interest. However, in laying new underground structures or replacing old ones, it is in the interest of safety to locate them at as great a distance from the rails as possible. Usually conditions other than electrolysis determine the location of mains, but where it is possible to locate mains on both sides of a street having car tracks, such construction prevents the crossing of service pipes under tracks and is in the interest of good electrolysis conditions. Where mains or services must cross under tracks there is a considerable advantage in having them as deep . as possible, but a depth of more than 4 or 5 feet is ordinarily not justified. 1. Avoidance of Accidental Contacts with Other Structures. From an electrolysis standpoint, it is usually necessary to treat lead sheath cables as distinct from other underground structures due to the fact that lead is appreciably more susceptible to corrosion from stray current than iron, and also because different measures are usually applied to the protection of lead sheath cables than to other underground metallic structures. One ampere flowing steadily for a year will carry into solution about 20 pounds of iron or about 74 pounds of lead. This high electrochemical equivalent of lead and the thin walls ordinarily used for cable sheaths require that unusual care be exercised in their protection. In the Bell Telephone System precautions are taken to avoid contact between its lead sheathed cables and other underground structures, such as foreign cables, rails, steel bridges, gas or water piping system and the metallic structure of steel-frame buildings. Where it is necessary that cables cross a bridge structure, this is frequently accomplished in creosoted wood duct. Occasionally, however, iron pipes are used to conduct cables across a steel bridge, 2. Conduit Construction. Cable sheaths cannot be said to be insulated from earth even when installed in non-conducting duct material, but as compared with pipes which are laid directly in the earth, their resistance to ground is generally very high. Unless surrounded with mud or water, cable sheaths usually make a line contact with the duct walls, whereas pipes make a surface contact of much greater area. The study of the insulation of cable sheaths from earth therefore resolves itself into a study of suitable conduit construction methods since experience has demonstrated the failure of any sort of wrappings, dips, or coatings to afford protection of any value from electrolysis. Indeed, wrappings, dips, and coatings have been shown to be distinctly harmful where pipes or cables are positive to the earth since they tend to localize the discharge of current and thus to accelerate failures. (a) Signal Cables. The experience of the Bell Telephone System has demonstrated that multiple and single vitrified clay duct and creosoted wood duct are all equally good as duct material from the standpoint of electrolysis, their choice in specific cases being a question of supply and cost. Iron pipe is occasionally used, but, due to its cost, only when necessary in avoiding obstructions. When iron pipe is used, it is so laid that there will be no contact between it and the trolley rails, steel bridges, water pipes, gas pipes or other underground structures or the metal work of buildings. When iron pipes must be laid as conduit so close to rails or other grounded metallic structures that a separation of at least one foot of earth cannot be obtained, the pipes are separated from the rails or other grounded metallic structures by a layer of concrete or creosoted plank Three inch, vitrified sewer tile with cement joints is now being commonly used for laterals to poles or building connections. In good conduit construction the necessity is recognized of rendering the joints between lengths of duct material, sufficiently tight to prevent the infiltration of dirt and silt and also to maintain a sufficient slope to the conduit to insure good drainage toward manholes, the manholes in turn being drained by sewer connections or to sumps. Particular care is exercised to prevent dips or pockets in conduit runs where moisture might collect. It is the practice to rack cables in manholes, a free space of twelve inches being maintained between the lowest cable and the manhole floor. The cables are in metallic contact with the metal hanger which, in turn, may be in contact with or built into the manhole wall, experience having indicated that no appreciable increase in cable resistance to earth is obtained by insulating the cables at these points with porcelain or other insulating material. Where lateral cables enter buildings, it is the usual practice in the Bell System to avoid all contact between the cable and the metal structures of buildings, and wherever this is impracticable, the continuity of sheaths on the entering cables is broken by an insulating joint. Occasionally conduit runs must be built through swampy ground or along sections of the coast where the conduit is permanently below sea level. Where such conditions are encountered, no method is practically possible for insulating cable sheaths from earth and such insulation is not attempted. Such locations are frequently extremely troublesome from the electrolysis standpoint, and therefore special precautions have to be taken. (b) Power Cables. The practice in conduit construction for light and power cables is somewhat different from that used for signal cables because the former are characterized by necessity of providing for troubles originating within the cables and for the dissipation of the heat losses of the cable. The most common types of duct material used are single duct vitrified tile, multiple duct vitrified tile, fibre conduit and stone conduit. Iron pipe is frequently used for short laterals to buildings and for cable pole connections, and occasionally where on account of lack of space other types cannot be installed. It is a common practice to install a 3-inch concrete envelope entirely surrounding all types of power conduits. Multiple conduit made up of single duct tile is laid with staggered joints and in the case of the fibre and stone conduit, the ducts are separated by an inch or more of concrete. Fibre duct is generally considered as a mold for the concrete which latter is depended upon for strength and for the separation of the cables in the several ducts. The waterproofing of underground conduits for" the purpose of excluding moisture and improving the conditions regarding electrolysis was tried a number of years ago, but it was very expensive and found to be quite useless unless the manholes also could be waterproofed, and this did not appear to be practicable. trolysis conditions vary considerably, but this is probably due to the nature of the soil in which the conduits are located, the amount of moisture in the soil and the character of the paving under which the conduits are installed. In those locations where the conduit is located in flat country with poor drainage and with the natural water level only slightly below the level of the conduits, the effect of the dirt and moisture in the ducts and the dampness in the surrounding earth is to lower the resistance of the cables to earth so that this value is not materially greater than it would be if they were installed directly in the earth. In other locations where the surface of the ground is hilly or sufficiently undulating to afford good drainage facilities, the cables installed in ducts with a concrete envelope are fairly well insulated from the earth. Although iron pipe is not generally used in line conduits, it is frequently necessary to employ it for laterals from manholes to poles and buildings, in order to avoid obstructions or to comply with requirements. If used as conduits for drained cable systems, iron laterals will increase the danger to gas and water service pipes which they cross. They also lower the resistance between the earth and cable sheaths which they contain and thereby enable the cables to pick up larger amounts of stray current than they otherwise would. In order to afford the return current a metallic path to the station in case of the failure of the cable, it is the standard practice with many companies to connect the lead sheaths of all of their cables in every manhole. This serves also to prevent serious differences in potential between the lead sheaths of cables in the same conduit at the time of a burnout and the resulting damage to lead sheaths in adjacent ducts which would otherwise occur. Where metal cable racks are used in manholes it is a frequent practice to insulate the cables from such racks, this being done to prevent damage from electrolysis as well as to prevent damage in case of a burnout of one of the adjacent cables. Unless necessary as a protective measure for isolated sections, cable sheaths should not be artificially grounded. Grounds in negative areas through which stray current might be picked up should be avoided wherever practicable. 3. Surface Insulation. In the early days of the use of lead covered cables for light and power in this country, it was customary to have the lead covered cables incased in a wrapping of jute saturated with a pre- servative compound with the idea of preventing damage to the cables by electrolysis. While this may have been fairly satisfactory as a temporary expedient, the preservative compound in the course of time would gradually disappear and the rotting of the jute would follow. In pulling such cables out of the ducts, it was found in some cases that the jute was so badly rotted that it could not be left on the cables when they were reinstalled in another location, and in other cases, the jute would adhere to the ducts or become caught on the edges of the ducts and form a very serious obstacle to the removal of the cable. Moreover, coatings of this character are not always a protection against electrolysis and may even accelerate it by localizing the corrosion, as explained in the discussion of surface- insulation for pipes. On account of these difficulties, the use of the jute covering on the lead covered underground cables was generally abandoned some years ago. 4. Insulating Joints. Some light and power companies have used insulating joints for protecting their cables from electrolysis. In some cases each section was connected to a ground pipe or plate under the floor of the manhole. If the conditions were favorable for electrolytic action, these ground plates or pipes served merely as auxiliary anodes and would be destroyed by electrolytic action in the course of a few years, thus rendering them ineffective except at a considerable annual expense for maintenance. Partly for this reason, but more because of the general adoption of cable drainage as a method of electrolysis mitigation, the use of insulating joints for protecting lead covered cables for light and power purposes has been practically abandoned in this country. As the drainage of cables requires continuous lead sheaths, insulating joints are not now ordinarily used in cable systems. With drainage it is also desirable that the several cables in any duct system be bonded together in the manholes so that all cables may be equally drained and also that in case of a failure of one cable the current through the fault to the sheath can find a continuous metallic return path to the station. If the insulation fails on a cable with an isolated lead sheath, the potential of the sheath will become approximately that of the conductor and destructive arcing may occur at the insulating joints, and in addition, holes will be burned in the lead sheaths of the cable where it is in accidental contact with other cables or where it rests on of the sheath. Under special conditions insulating joints can sometimes be used to advantage in protecting cables from electrolysis, as for example, when the cables are remote from any railway tracks or negative return circuit to which they can be drained, or where a cable system which is not drained can be prevented from collecting stray current at points of intersection with railway tracks by their use. Fig. 17 shows the type of insulating joint used by several large electric power companies in the sheaths of transmission cables which are not protected by drainage. Another situation sometimes requiring insulating joints in order to prevent cables from picking up excessive current, or to prevent arcing, is to be found where they make contact with a steel bridge or are otherwise brought into intimate contact with the earth. Under such conditions the section making contact can be isolated by the use of insulating joints and continuity of the system maintained by bonding around the section so isolated. Such conditions as these, however, are comparatively rare. Insulating joints in lead sheaths are not only expensive but represent points of discontinuity which may give rise to various troubles and are usually avoided in practice except under such unusual conditions as are here mentioned. In the cities where there is trouble from electrolysis, the service pipes of the gas and water companies are more subject to failure than the cast iron mains as the walls of the wrought iron pipes are much thinner. Also, in the electrolytic corrosion of cast iron pipe a graphitic residue remains intact and has a strength sufficient to withstand gas pressure and in some cases even low water pressure, while with wrought iron or steel the metal is corroded away without leaving such a residue. For these reasons some gas companies have made it a practice to apply a surface covering to their service pipes. This covering is generally similar to that described above for lead covered cables, but it sometimes consists of several layers of jute, burlap, cheese cloth, or paper, each of which has an application of insulating preservative compound before applying the next layer. Such insulating coverings have been more successfully applied to services than to lead covered or steel gas mains. The principal difficulty in coatings applied to pipes or lead cable sheaths is that the coatings are not continuous and that in spite of all efforts for their prevention minute holes or pores will exist in such coatings. Through these minute pores the electrolyte will ultimately penetrate and electrolytic action will result. As the amount of pipe or cable surface exposed through these pores is small, the action will be very slow at the start and it may be quite imperceptible for a number of months. In the course of time, however, if the conditions are favorable for electrolysis, an oxide of the metal will be formed opposite the pores and as the oxide occupies more space than the metal, the coating will be lifted from the metal, thus rapidly increasing the area of metal exposed to the electrolytic action. As this action is concentrated at a comparatively few points by the coating, the result is that the destruction of the pipe or cable may occur more rapidly, due to this intensified local action, than would occur if the pipe or cable was without such coatings so that the action would be distributed over the entire area of pipe or cable. Surface insulation for the protection of pipes and cables against soil or salt water corrosion is often effective, but as described above, these coatings gradually deteriorate when subjected to any appreciable potential difference. Thick coatings in the form of pitch or parolite poured into a containing box built around the pipe, have been used successfully in special cases. The box should be quite strong so as not to sag beneath the weight of the insulating material while pouring or after back-filling. The pipe should be supported in this box by means of blocks of glass or of pitch impregnated wood, so as to prevent its exposure in the event of the cold-flow of the insulating material. In pouring, extreme care must be exercised to prevent particles of earth or stone from getting into the box, and the insulating material should be hot enough to flow freely without boiling or bubbling. If it is too hot, the boiling or bubbling will result in air holes when the material solidifies, and these air holes may admit moisture to the pipe. If the pipe to be covered is laid on a grade, or if it is more than 25 feet long, it will be necessary to pour the material in sections, using dams made of pitch impregnated wood to retain the molten material. The material should cover the pipe to a depth of about two inches and a rigid cover should be placed on top of the box or trough to prevent stones or earth from working their way through the insulating material. This boxing method is also applicable to service or other small pipes, and while somewhat more expensive, it is preferable to the wrapping method because in its application there are fewer chances of imperfections escaping detection. Too much care cannot be exercised in applying insulating coverings in regions where there is a strong tendency for current to leave the pipe. A single imperfection through which moisture can reach the pipe will cause it to be destroyed more rapidly with the covering than without it. As an additional precaution where insulating covering is applied in a positive area, insulating joints are often installed in the pipe at each end of the covering. If the covered section is more than 2,000 feet long, additional insulating joints should be installed at intermediate points. The application of insulating covering is not always limited to the positive areas in which current tends to leave the pipe. They are quite often used to prevent current reaching the pipe, in negative areas, where a pipe crosses or comes near to a trolley line or other underground metallic structures to which it is highly negative. The costs of installing insulating coverings of the character referred to will vary over fairly wide limits, depending upon the size of the pipe, the length to be covered, the character of the soil, and the depth of the pipe, etc. In 1915 the cost of boxing and covering 500 feet or more of 8-inch line laid at a depth of about 30 inches in ordinary soil averaged about one dollar per foot. In 1919 this figure had increased to about three dollars per foot. (a) New Work. The value of insulating joints in pipes as a means of preventing or reducing electrolysis has long been recognized, but the manner of employing them has not always been such as to accomplish the desired end. Their effectiveness will depend very largely upon the frequency with which they are installed in any pipe line and somewhat upon other factors, such as the resistivity of the soil, the magnitude of the potential gradient in the earth and the degree of isolation maintained with respect to other underground structures. It is sometimes possible to break up the electrical continuity of the line and substantially protect it from electrolysis by the use of a comparatively few insulating joints, but in these cases tests should be made to see that the longitudinal flow of current along the pipe has been practically eliminated. The services can be prevented from making electrical contact with other systems by the use of insulating joints within the premises served, as shown in Fig. 18. Without the insulating joint in the service pipe, stray current could enter from the other piping system and injure both the service and the section of main to which it connects. Some gas companies, principally natural gas companies, have established the practice in all new work of insulating services at the meter connections within the premises, thus preventing the flow of current between gas and water services. If this is generally applied on new mains of considerable length, it is also advisable to install insulating joints at selected locations on the main. (b) Cement Joints. Cement joints have long been used on gas mains and have been found to preserve a high resistance over a long period of time, and if used in sufficient numbers they are effective in preventing the flow of stray current on pipe lines. The standard cast iron bell has been used successfully with cement joints on small mains but some gas companies have had difficulty in using cement on mains 12 inches in diameter or larger. Cast iron pipe is now being manufactured with the bells especially designed for cement joints so that they can be used on large size mains. This joint, illustrated in Fig. 19, is known as the type B joint, as covered by the specifications of the Committee on Cast Iron Pipe Joints of the American Gas Association. The calking recess is unusually long and has a slight taper whereby the joints are tightened when the pipe line contracts. When properly made, these joints have a mechanical strength considerably in excess of the pipe itself. (c) Leadite and Metallium. Other substitutes for lead, such as "Leadite" and "Metallium" are being used on water mains. Some years ago the Bureau of Standards made tests on "Leadite" joints and found this material when new to have a very high electrical resistance, comparable with that of cement, but after several years in service to decrease in resistance to only a very mall fraction of the original value. The change was attributed to the slow oxidation of the sulphur contained in the compound, resulting in the production of sulphuric acid. No corresponding data are yet available on "Metallium." (d) Dresser Couplings of the ordinary type which have been extensively used on wrought iron and steel gas mains are uncertain and variable in their resistance, depending upon the manner in which they are installed. However, if used throughout any pipe line their average resistance is so high as to practically eliminate the flow of stray current. (e) Special Insulating Joints. A special high resistance joint is made, known as the "Dresser Insulating Coupling," and is used to prevent the flow of stray current on pipes. Insulating joints, such as wood stave joints, and flange joints with insulated bolts and gaskets of insulating material are sometimes used on large mains at river crossings or at points of intersection with street railways and at other special locations. The effective length of such joints can be increased by thoroughly insulating the pipe with wrappings or covering for some distance on either side of the joint. This treatment is often applied to important oil and high pressure gas pipe lines. (f) Insulating Joints Applied to Kxisting Pipe Lines. Pipe lines acting as ties between two extensive systems or networks sometimes carry considerable current from one system to the other and this can be reduced or practically eliminated by the use of comparatively few insulating joints installed in the main connecting the two systems. To distribute the stray current around insulating joints so installed, the joint can either be made long or the pipe insulated for some distance on either side. A large industrial plant or a small community may be supplied with gas or water through a single pipe over which stray current may flow and cause damage at some point which would otherwise not be in danger. The use of one or more insulating joints will often correct such a condition at little expense. A pipe line crossing under an electric railway track or through a river or wet ground can be prevented from discharging or collecting current at such points by the use of insulating joints on both sides of the exposure. Service pipes which are subject to corrosion at points where they cross under railway tracks are often insulated from the mains by the use of insulating joints at times of replacements thus pre- Insulating joints are also frequently used to prevent the interchange of current between two piping systems, as shown in Fig. 18, or between a piping system and a cable system or other underground structures. In order to protect gas services or water services where they cross under tracks, it is often necessary to install insulating joints both at the main and within the premises to prevent the flow of current from services of another system to which they may connect. This condition exists where gas water heaters are in use as these appliances usually make a firm metallic contact between the gas and water services. In Fig. 20, if the gas and water mains are both positive to the track, accelerated corrosion will take place on the services where they cross under the track. To protect one service without regard to the other, it is obviously necessary to install insulating joints at A and B, or C and D. Insulating joints have been installed at selected locations by some gas and water companies as an auxiliary to a negative feeder system. For example in Providence, Rhode Island, after an insulated negative feeder system was put in operation insulating joints were installed on gas and water mains to still further reduce the stray current on the pipes. The cost of installing insulating joints when pipes are uncovered for repair or replacement is comparatively a small item, and often affords a satisfactory means of preventing further damage to them. 3. Shielding. In special cases underground structures have been protected from electrolysis by connecting to the structure an auxiliary metallic conductor located so as to cause the current to flow to earth from the auxiliary conductor. This mode of protection is known as shielding. The method has in some cases been applied to the dead end of an underground metallic structure which is highly positive to earth. In such cases an auxiliary shielding plate or pipe of adequate ground contact surface extending beyond the dead end and electrically connected to the structure to be protected has been installed in such a manner that the bulk of the current was caused to leave the auxiliary shielding conductor, thus affording a certain degree of protection to the dead end of the structure. One application of this method, which is in use, is that of a service pipe crossing under tracks or crossing other structures to which it is positive and where the pipe comes relatively close to the rails or other structures at the point of crossing. In these cases a larger shielding pipe, usually of heavy cast iron, has been placed around the service pipe and electrically connected to the service pipe and extended sufficiently on each side of the crossing so that the major part of the current was caused to leave the shielding pipe, thereby corroding the latter while protecting the service pipe. It is very important that a thorough metallic connection be made between the pipe to be protected and the shielding pipe. Otherwise, the service pipe is likely to corrode where current leaves it to flow through earth to the shielding pipe. Unless the shield is in the form of a pipe completely surrounding the structure to be protected, this method of protection is uncertain and should be used only in very special cases. When applying this method it has been found necessary to take care that the auxiliary shielding conductor does not merely increase the electrode area from which the current leaves, because in this case the current will continue to leave from the structure which is to be protected unless an insulating covering is applied to the pipe beyond the protecting shield. This has been found to be the practical result where a shielding conductor of the same or less contact area was placed in the earth near the structure to be protected and where the stray current has left both structures. A. ELECTRICAL DRAINAGE OF CABLE AND PIPE SYSTEMS Electrical drainage consists in connecting the affected structure to the railway return circuit by insulated conductors in such a manner that the current leaves the structure through these connections instead of flowing to earth. This prevents corrosion in the neighborhood of the drainage connections, but increases the current flowing on the structure and the voltage drop along it, which latter results are generally undesirable for reasons discussed in detail in subsequent paragraphs. Drainage connections are usually made by running copper cables either to the busbar of the railway supply station or to negative return feeders. Connections to tracks should be avoided because the failure of rail bonds might cause dangerous currents to flow over the drainage connection and also because of the possibility of getting a current reversal, particularly when the adjacent substation shuts down during the light load period. However, when insulated negative feeders are used, the drainage connections may be made to the rail terminals of the feeders. Connections to rails are sometimes installed where a conduit line or a pipe crosses a railway track at a considerable distance from the power supply station and other means of draining would be awkward and expensive, but they should be made with considerable discretion and should be carefully recorded and regularly inspected. Where used, drainage should be reduced to a minimum consistent with the protection of the drained structure in order to reduce the hazard to other adjacent underground systems. The drainage of one system tends to establish differences of potential between the various underground systems, resulting in interchange of current with consequent injury to the system at the higher potential. In order to avoid this condition, it is desirable to interconnect the various systems and drain them over common conductors. As structures owned by different interests cannot be bonded together except by an agreement between the owners this has frequently of itself made it impossible to apply a comprehensive drainage system to all structures because of the impossibility of obtaining an agreement of all owners to allow connections to their structures, except on condition that other interests assume liability for any injury which may result from such interconnections. If, however, the foregoing method of unified drainage is carried out so that the drained structures are at all times negative to earth, no electrolytic corrosion of such structures will result. Just how difficult it may be to maintain pipes negative to earth at all points and at all times by means of drainage is a question which cannot be answered until investigations have been carried further. The objections to electrical drainage apply most forcibly to pipe networks, particularly to gas and oil pipes on account of the inflammable substances carried. Drainage should be considered only as a supplementary measure to the improvement of the railway return circuit or as a temporary measure in cases where acute electrolytic corrosion has resulted. It can never take the place of an adequate railway return circuit. there are engineers who believe that pipe drainage has a definite field of usefulness. The Committee, through its Research SubCommittee, is still actively engaged in investigating the magnitude and importance of the technical factors involved and until further information shall have been acquired, the Committee will not be in a position to reach a conclusion on this subject. 1. Drainage of Cable Sheaths. (a) Method of Draining Cable Sheaths. In order to afford complete protection to cable systems, it has been found that they should be interconnected and have drainage conductors of sufficient conductivity located so that the lead sheath of the cable network is everywhere lower in potential than the adjacent earth. Cable systems are usually installed in vitrified clay, creosoted wood, or fibre ducts, and if kept free from water, the tendency to collect current is much less than if they were in direct contact with the earth. Owing to the higher resistance thus introduced between cables and earth and the continuous character of the cable sheaths, it is usually possible to lower the potential of the system below that of the adjacent earth in all localities by draining relatively small currents at one or more points. In order to prevent the interchange of current through earth between the several cable sheaths in any conduit system, it is necessary to bond the sheaths together at frequent intervals. Some companies make a practice of bonding at every manhole and good practice requires such bonding at intervals not to exceed five hundred feet. Bonding is usually accomplished by sweating a flat copper strip or a copper cable to all cables within any system which may properly be bonded together. Foreign cables which enter any duct system are also bonded to the system they parallel. It is often necessary to interconnect signal cables with lighting and power cables so as to avoid differences of potential which might otherwise occur, but where this is done, a fuse should be installed in the bond connection to the signal cable so as to eliminate the possibility of high voltage current getting on the signal cable sheaths. It is desirable to provide means for measuring all drainage currents and where the drainage feeder is extended to the supply station, an ammeter or shunt is usually installed for that purpose within the station. Where the drainage cable does not enter the supply station, measurement can be made within a manhole or on a pole, or wherever the drainage cable is accessible. from the railway supply station, it is necessary either to use a long copper cable for drainage at a considerable expense or to resort to some other method of protection. Aerial telephone cables are sometimes used for this purpose, but are not employed except when other conductors are not available or would be unduly expensive. Cables are sometimes found to be positive only during certain periods of the day or their potential may reverse from time to time due to fluctuations in the railway load. Where this condition is considered dangerous from the electrolysis standpoint an automatic switch is sometimes installed which is closed during the period the cable is positive and automatically opens when the cable becomes negative, the object being to prevent the cable from taking on current while in a negative condition. The cost of automatic switches and the fact that they add an objectionable complication to the plant are reasons why their use should be restricted as much as possible. Automatic or manually operated switches should be provided in all drainage cables terminating in railway supply stations in order that they may be opened during the period when the station is not in operation. Automatic substations which start and stop without attendants should be provided with facilities for accomplishing this result. (b) Heating Effect of Stray Current on Cable Sheaths. Stray current on the sheaths of lead covered cables causes a heating effect which impairs the carrying capacity of power cables. In some cases this effect may be objectionable. The following formulae have been developed for single conductor and three conductor cables to give their current carrying capacity when sheath currents flow. The values obtained give the conductor the same temperature rise above surrounding structures as produced by their normal current when no sheath currents are present. The formulae have been developed on the following basis: 1. That the watts dissipated in the sheath are effective in raising the sheath temperature but that they do not affect the rise of the conductor over the sheath. 2. Resistivity of lead 12 times that of copper. This assumption, while not strictly correct, will give results within an accuracy obtained by considering other factors as constants, such as the radiation constants of the lead sheath. The values of A, B, and C can be found for single and three conductor cables by referring to Atkinson's article on "Carrying Capacity of Cables" in the September, 1920, issue of the Journal of the A. I. E. E. Examples 1. Single conductor cable, 250,000 C. M., 1/8 inch lead sheath, 4/32 inch paper insulation. Normal current 510 amperes. What is resultant carrying capacity with 100 amperes sheath current? In a similar way the reduction of current carrying capacity for certain cables has been calculated in Tables 1 to 4. Tables 1,2, and 3 are for single conductor cables for 250 volt, 2,300 volt, and 600 volt service, respectively. Table 4 is for 13,200 volt, 3 conductor cables. and 2 for rubber insulation is based on the following formula. Wherein the following terms are used : di = diameter of copper in inches. dz = diameter over insulation in inches. dz = diameter over sheath in inches. K = resistivity of insulation in degrees C. rise per watt per inch cube. J = radiation resistivity of lead sheath to ambient surroundings in degrees C. rise per watt per inch square. r = resistance of conductor at 7\, per inch length. / = current carrying capacity of cable. Tl = permissible copper temperature, in degrees C. T2 = temperature of ambient surroundings in degrees C. In solving the formula, the following values of the several constants were taken : . The normal ampere rating in tables 3 and 4 for paper insulation is based on the data in the paper entitled "High-Tension, Single-Conductor Cable for Polyphase Systems," by W. S. Clark and G. B. Shanklin, Transactions of the A. I. E. E., 1919, Vol. XXXVIII, page 917. The conductor temperatures used are in practical agreement with Rule 9100, page 95, Revision of 1921 of the Standards of the American Institute of Electrical Engineers. Where different normal ampere ratings or temperatures are used, the percentages of normal current that can be carried with various sheath currents will differ from those given in these tables. Naturally, the effect of sheath currents is greater for small and medium sized cables, and it may be noted that cables of these sizes and types are most commonly met in complicated distribution networks. Also, for the same size conductor, a given sheath current will reduce the current carrying capacity of the cable to a lesser extent as the insulation thickness is increased. In cases where drainage must be employed and where heating is a factor, the sheath currents can be reduced to a minimum by limiting the drainage to the smallest values which will protect the system. TABLE 4. EFFECT OF SHEATH CURRENTS ON ALLOWABLE CONDUCTOR CURRENT OF ROUND THREE CONDUCTOR 13,200-VOLT 6/32 BY 6/32 PAPER INSULATED CABLES DUE TO STRAY CURRENTS FLOWING ON SHEATH. SHEATH ASSUMED 1/8" THICK. 350.000 c.m.. Good duct construction with vitrified clay or fibre conduit for laterals and main conduits, and the draining of manholes to sewers or by sumps will tend to increase the resistance of the cables to earth, and thereby reduce the tendency to collect stray currents. On the other hand, thorough grounding of sheaths is in many cases resorted to as a protective measure for isolated sections. Where it is impossible to protect cable systems by natural drainage, boosters have occasionally been used to artificially lower the potential of the cable system. This practice, as well as the over drainage of cable systems, is objectionable where other underground structures are involved as it may result in unusually high potential differences between the piping and cable systems with resulting damage to the pipes. 2. Difference Between Cable Drainage and Pipe Drainage. apply the same method of protection to underground piping systems. The result is that more or less pipe drainage has been used, particularly on water systems and to a limited extent on gas systems. While the success of protecting cable systems by drainage is generally recognized, there are important differences in the application of drainage to cables and to piping systems which make the application of drainage to the latter difficult and uncertain. Among the important differences between the drainage of cable and piping systems are : 1. Cables are electrically continuous and uniform conductors, while pipes are not uniform conductors and are sometimes discontinuous conductors due to the joints in them. Experience indicates that in mains having cement joints a large percentage of these joints are of high resistance, and in mains having lead joints, occasional joints of very high resistance are found and many of the joints have resistances higher than several lengths of pipe. -Therefore, drainage will lower the potential of the pipe for relatively short distances from the drainage taps, so that to be effective a greater number of drainage taps must be installed than for a cable system of the same extent. The number and location of taps will depend upon the extent and physical layout of the pipe network, and the expense involved will depend upon the number and locations of the taps required. 2. Under certain conditions there is a tendency for current flowing on a pipe to leave it on the positive side of a high resistance joint, returning to the joint on the negative side, or else to flow to another structure. As a result of this, joint corrosion may occur at high resistance joints unless both sides of the joint are maintained negative or neutral to the adjacent earth at all points and under all conditions; and conversely, no electrolytic corrosion will occur on either side of a high resistance joint if the entire surface of both the adjacent pipe lengths is permanently negative to the surrounding earth. The difficulty of keeping a complicated network of pipe negative to the adjacent earth by means of drainage is much greater than in the case of cable systems. 3. Cable systems are placed in ducts with manholes conveniently spaced so that the effect of the application of drainage to a cable system may be adjusted so as to produce the results desired, whereas with pipes buried in the ground, and in large cities beneath improved pavements, it is more difficult to make the necessary measurements to ascertain the effects of drainage. unless they are in wet or marshy ground, they are but partially in contact with the earth, whereas, gas or water pipes are buried directly in the earth. Because of this condition, the drainage of an underground piping system with, but few high resistance joints results in the flow of larger amounts of current than does the drainage of a cable system. 5. Currents flowing in piping systems conveying inflammable substances, such as gas or oil, constitute a fire and explosion hazard and many cases have been reported where stray currents have caused arcs which have ignited the gas or oil when the continuity of the pipe was broken. One of the objections to the presence of excessive currents on gas or oil pipes is the necessity for bonding around a cut in the pipe whenever a pipe is opened for repairs. Under such conditions a copper wire cable is connected around the point on the pipe to be opened. Jumper cables, terminating with adjustable clamps are used by some companies for this purpose. Under certain conditions there is also danger of increasing potential differences between service pipes in confined air spaces which may result in causing arcs due to the intermittent contact between pipes which will puncture the gas pipes and ignite the escaping gas. 3. Application of Drainage to Pipes. (a) Maintaining Pipes Negative to Earth. Investigations of the Research Subcommittee show that when electrical drainage feeders are connected to a jointed piping system the drained pipe is maintained negative to the soil for only a few hundred feet from the point of connection. In such cases it is necessary to extend the drainage feeder along the principal pipes in the positive area, which extends theoretically about 40 per cent of the distance from the supply station to the end of the feeding district, and connect to the pipes at frequent intervals. (b) Effect of Pipe Drainage on Current Interchange. Various conditions exist in piping systems which tend to affect the interchange of current between them, and these should be fully recognized in the consideration or employment of pipe drainage. If a single pipe system exists, as for example, a water system in a small town, the drainage of that system will not as a rule result in objectionable interchange between various parts of the network. However, there are usually several piping systems present, such as a lead calked water pipe system and a lead calked gas pipe system. If these piping systems are not interconnected at many change of current. The application of drainage to one piping system in a territory where another piping system exists may result in an interchange of current between the drained and undrained systems so it is necessary to resort to the common drainage of all of the piping systems to be protected, as the potential inequalities created by separate drainage cause electrolysis at points where the current leaves the undrained system to find its path to the drained system. Even with the most carefully installed and maintained unified system of drainage, it cannot be expected that all danger from current interchange will be eliminated. Pipe systems laid with cement joints, Dressser Joints, or other high resistance joints and not interconnected with other systems, will usually need no other form of protection against electrolysis. If, however, such a system exists in a territory also occupied by a piping system with lead calked joints and connected to it at many points through applicances or otherwise, the service pipes of the system with the high resistance joints and the sections of the mains to which they are connected, will be electrically connected to the more continuous system and so far as electrolysis is concerned should be considered as a part of that system. Any electrolysis condition existing on the continuous system will therefore be experienced by such service pipes and the sections of the mains of the discontinuous system as connect directly with it and any measure which tends to protect the continuous piping system will also affect the services of the discontinuous system. This condition is illustrated in Fig. 18, where a continuous water piping system is connected through appliances to gas services. Although the gas mains are laid with cement joints, they are being damaged by current brought to them over the water mains. The application of pipe drainage under conditions here described may afford protection to some portions of the piping system and increase the damage to others. In some areas gas services and water services are connected with each other through appliances so that at these locations the two piping systems are maintained at practically the same potential. In most piping networks, however, there will be extensive areas where the gas and water systems are not interconnected by such appliances and even where they do exist they cannot always be relied upon to maintain the two systems at practically the same potential. (c) Effects of Different Kinds of Pipe and Joints. A fundamental difficulty in applying electrical drainage to piping systems is usually present and this is the great variation of conductivity of different kinds of pipes and of different joints. In any cast iron piping system the resistance of the joints varies through wide limits. In many cities there are a number of different kinds of pipes in use: steel mains with welded or screw joints have a low resistance; steel mains with gaskets made of rubber are high in resistance, while cast iron mains with cement joints are unusually high in resistance. With electrical drainage the current on the pipes is increased and the potential drop along these pipes and over the joints is increased in like proportions. SUMMARY OF GOOD PRACTICE This summary is intended only as an annotated index or guide to the contents of Chapter 2 of this report, not as a substitute. Before forming an opinion or taking even preliminary action on any subject treated in the report the full text should be studied. (a) The use of heavy rails with joints properly bonded and well maintained is the first requirement for good track conductivity and the minimizing of stray currents. and most permanent form of bonding. (c) Rail joints including three feet of rail which have a resistance in excess of 10 feet of adjacent rail should be rebonded, except joints bonded with long bonds, which should be renewed when the resistance exceeds that of 15 feet of adjacent rail. (d) Bonded joints should be tested at least once each year and such tracks as show bond failures in excess of 5 per cent annually should be tested every six months. A failure is here defined as exceeding the resistance specified in paragraph (c). (e) Cross bonds, connecting the two rails on single track, and the four rails on double track should be installed at intervals not to exceed 500 feet in city systems and from 1,000 to 2,000 feet on interurban lines. (f) Jumpers of one or more conductors should be used around all special work, and should connect to all rails on both sides of the special work. The size of such jumpers should be proportioned to the current on the rails, but in no case should they be smaller than No. 0000 for one track. In addition, where practicable, all special track work should be bonded and maintained as other track rails. (a) In the construction of electric railway tracks and roadbeds the electrolysis problem should be given consideration with economy of construction, maintenance, and operation. (b) Roadbeds should be constructed with as high electrical resistance to earth as consistent with other considerations, special attention being given to keeping them dry by drainage. Where practicable, rails should be kept out of contact with the earth. under ties. (d) Where crushed stone or gravel ballast is used it should be kept clean. If earth, sand, or street dirt is permitted to filter into ballast of this character its insulating property is greatly impaired. Vegetation should be kept down, as this tends to make the roadbed moist and to fill the ballast with foreign material. (e) Salts, which are often used to prevent freezing at switches and frogs, greatly reduce the resistance of roadbeds and should be avoided as much as possible. Copper is not economically employed when connected in parallel with tracks, and therefore subjected to the same voltage drop as exists on the tracks, as it cannot be loaded to capacity with track voltage drops ordinarily permissible. Buried copper conductors or old rails used to supplement the track return also increase the contact area between the return circuit and the earth and thereby tend to augment stray currents. For these reasons the use of such supplementary conductors should be avoided. gradients in the tracks. (b) In selecting locations for substations, particularly for interurban lines, consideration should be given to the extent and character of the underground* metallic structures in their immediate vicinities. bare track feeders in earth or in water courses should be avoided. (d) Numerous independent connections to the track for the return of current aff<prd the most effective means of reducing high potential gradients and overall voltages and thereby limiting stray currents, and as many should be provided as consistent with good engineering and economic considerations. This can be accomplished by the use of additional power supply stations, by the installation of insulated negative return feeders, or by the three-wire system wherein each car on the negative trolley becomes a point of return. Combinations of these may also be employed. (e) The most generally satisfactory method of increasing the number of independent return points on a track system is by the use of additional substations and the tendency of railway practice is now in this direction. (f) Considerable progress has been made in recent years in the development of automatic, semi-automatic, and remote control substations and these are now being used both on interurban lines and for city service. The economies attending such substations make possible a greater number of feeding points than can economically be supplied through manually operated stations. (g) By employing the maximum number of substations consistent with economy, rather than the minimum number, stray currents will be greatly reduced. As a rule, interconnection of tracks will improve general electrolysis conditions, but may be detrimental in one locality while improving conditions in another. (a) Track gradients and overall potentials can be limited to any desired extent by the use of insulated negative feeders but the cost of such installations, the additional power loss accompany- ing their use and the reduction in operating voltage at the cars may make their use uneconomical except in connection with frequent power supply stations. (b) In general in the application of insulated negative feeders, the negative bus should be connected to the track at more than one point, that is, negative feeders should be extended along the track to nearby intersections. Small stations of 300 to 500 kw. capacity in city networks may usually be connected directly to the track at one point only and preferably to the nearest track intersection. (c) Insulated negative feeders should be run from the negative bus to the rails in such a manner as to insulate them thoroughly from the earth and from each other. The tying together of any of these feeders should be avoided. In some cases, however, it may be allowable to tie a single feeder to the rail at two or more points through resistances to adjust the currents drawn from the tracks at the various points of connection. rather than in wet locations. (e) Means should be provided on all negative feeders and feeder taps for conveniently measuring the current flow thereon and where practicable these means should be installed within the power supply station. operating voltage at the cars. (b) Where a few large supply stations are used the first cost of converting an existing railway system for three-wire operation is usually smaller than the first cost of any other measure which will give the same degree of protection from electrolysis. (a) With reversed polarity the amount of stray current is not reduced but the electrolytic corrosion will be scattered over the outlying districts instead of being confined to the vicinity of the power supply station. With reversed polarity the drainage of cable sheaths is rendered impracticable. (b) This measure should not be considered except as a temporary means of relieving dangerous conditions in the vicinity of the power supply station at the expense of the cables and piping systems at a distance from the station, pending the installation of an effective method of electrolysis mitigation. (a) If the polarity of the trolley system is reversed daily, electrolytic corrosion will be materially reduced although the drainage of cable sheaths will be rendered complicated or impracticable. (a) Practically complete immunity from electrolysis can be had by the use of a properly maintained double contact conductor system either underground or overhead, but the expense and difficulties involved in such an installation are not justified merely as a means of electrolysis protection. as far as practicable. (b) On streets in positive areas where car tracks exist gas and water mains are sometimes installed on both sides of the streets. Such construction permits the use of shorter services and obviates the necessity for placing service pipes under tracks. (a) In the installation and maintenance of cable systems precautions should be taken to avoid contact between lead sheaths and other underground structures, such as foreign cables, rails, steel bridges, gas or water pipes and the steel frames of buildings, except as such contacts may be required for specific reasons. (a) Cable sheaths should be kept out of intimate contact with the earth by the use of suitable duct materials, proper conduit construction, and Adequate conduit drainage. Dips in the conduit where moisture might collect should be avoided wherever practicable. is suitable or permissible. (c) Wherever long laterals to poles are installed the horizontal portion should be of vitrified tile, fiber, stone or some similar duct material, using iron pipe only for the bend at the base of the pole and for the vertical portion up the pole. (d) Unless necessary as a protective measure for isolated sections, cable sheaths should not be artificially grounded. Grounds in negative areas through which stray current might be picked up should be avoided whenever practicable. (a) Insulating joints are sometimes used in cable sheaths under special conditions to prevent electrolytic injury which might result from contact with steel bridges or buildings. They are also occasionally used to prevent the flow of current on cable sheaths where drainage is undesirable or impracticable. electrolysis. (b) Thick coatings in the form of pitch or parolite poured into a containing box built around the pipe are occasionally used in preventing electrolysis under special conditions where the expense is warranted. (a) Insulating or high resistance joints, such as those of the Dresser type or cement joints, if used throughout a pipe line at frequent intervals, or at specially selected locations may afford substantial protection against electrolysis. This practice relates particularly to gas and oil pipes. (b) It is sometimes permissible to use a comparatively few insulating joints if care is taken to see that the flow of current on the pipe is practically eliminated. (a) Lead sheath cables in urban districts or where parallel with interurban railways commonly require some form of electrolysis protection and this is usually accomplished by drainage. of the cable. (c) Drainage connections should be made to the negative bus of the railway supply station or to the rail terminal of insulated negative feeders. Connections to the rails should in general be avoided. (d) Cable sheaths when drained are made negative to the surrounding earth at practically all times. Drainage should be reduced to a minimum consistent with the protection of the cables. (e) In general, all signal cable sheaths in any conduit system should be bonded together at every man hole. Where advisable and permissible all power cable sheaths should be similarly bonded. (f) So far as practicable or advisable, all cable systems should be drained at the same locations or by the same drainage feeders and differences of potential between adjacent or intersecting cable systems should be eliminated by cross bonding. (g) Fuses should be installed in all connections between signal and power cable sheaths, and should be so proportioned as to protect the sheaths from dangerous currents. (h) Means should be provided for conveniently measuring all drainage currents and maintaining close supervision on all drainage systems, and where possible this should be accomplished by installing meters within the power supply station and making them accessible to the cable owning companies. (i) Means and operating regulations should be provided for opening all drainage cables during periods when reverse currents would otherwise flow over them, if the magnitude and duration of such reverse currents is objectionable. (a) There are wide differences of opinion among competent engineers who have studied pipe drainage, as to its adaptability to various conditions. Numerous questions are involved in regard to which there is not sufficient information available at the present time to permit the drawing of accurate conclusions, and for this reason this subject is being investigated by the Research Sub-Committee of the American Committee on Electrolysis. There are, however, certain objections to the use of pipe drainage which are discussed in this report and which should be carefully considered before employing it. and they greatly complicate the application of drainage. (e) To lower the potential of a jointed piping system below that of the surrounding earth, it is usually necessary to extend the drainage conductors over a considerable area and connect to the pipes at numerous locations. (f) Corrosion at high resistance joints in pipe lines carrying current may occur unless the pipe on both sides of the joint is maintained negative or neutral to the adjacent earth, in which case no corrosion will occur. networks exist. (i) Drainage of a large network of pipes should be used only as an auxiliary to a railway system, properly designed and maintained from the electrolysis standpoint. When so used it should be installed and maintained under competent supervision. Electrolysis surveys deal with the various methods and classes of measurement employed to determine the hazard to underground metallic structures due to stray electric currents, the extent of existing damage already produced, and the mitigative measures that may best be employed for reducing the danger of future trouble. There are discussed below the methods of determining electrolysis conditions, of collecting data upon which the design of mitigating systems may be based, the types and kinds of instruments that should be used, the procedure to be followed in the working up of the data, and the interpretation of the results of the survey. 2. Difficulty of Standardizing Survey Procedure. It should be emphasized that in general, no two electrolysis surveys will be conducted in precisely the same manner, so that specific rules of procedure cannot be laid down that will be applicable to all cases. The procedure set forth below is intended to cover the measurements that experience has shown are most frequently required, and to describe the best methods of taking such measurements. The number of readings taken and the procedure to be followed will vary so much with local conditions that reliance must be placed on the judgment of the person making the test. In fact, the proper procedure during a large part of the survey will depend in large measure on the results obtained in preliminary tests. It is important, therefore, that electrolysis investigations of any importance be made under the direction of a competent engineer very familiar with methods of procedure and the interpretation of electrolysis test data. areas in which pipes and other structures are endangered by stray currents and, with sufficient accuracy for most purposes, the degree of seriousness of the trouble. The cause of any damage that may be in progress at the time of the survey, whether due to stray currents or corrosion by the soil, cinders, or other natural causes, can generally be ascertained, and in the case of stray current corrosion, the source of the current can generally be determined. The various factors connected with pipe systems, such as high resistance joints, very low soil resistances, and the use of improper mitigative measures, can also be detected. Defects in the railway return system, such as poorly bonded rail joints, infrequent cross bonds, insufficient conductance in the negative return, improper use of such conductance, excessive feeding distances and other causes of electrolysis trouble can usually be B. TYPES OF SURVEYS In the following discussion several types of surveys must be recognized. The first is that which may be called a complete electrolysis survey which is made for the purpose of determining the extent and location of the danger areas, and with a view of determining the proper procedure to be followed for the mitigation of any trouble which may be found to exist The second type of survey, known as a maintenance survey, embraces such surveys as would usually be made by a pipe or cable owning company, solely for the purpose of determining whether previously existing conditions have changed and differs from the more complete survey mainly in that most of the information with respect to the railway power distribution system is not required and fewer electrical measurements are taken, the number and character of such measurements depending on the thoroughness with which the survey is to be carried out. A third type of survey which needs little discussion, except as to methods of making tests, is one made to determine whether ordinances or regulations governing electrolysis conditions in a municipality are being complied with. Such surveys are usually made periodically, in periods varying from three months to a year. In general, only those quantities are measured which are specifically defined by the ordinances or regulations which are in effect in the locality in question. In making electrolysis surveys, a considerable amount of preliminary data are usually desirable. It is important first to gather all evidence regarding the character, extent and location of known damage to underground structures. This evidence is usually obtained from the utility companies concerned, but even though these companies can give no direct testimony as to the injury to underground structures, this should not be taken to indicate that no damage exists. The data on the underground systems should include the relative location of the mains, the railway tracks and underground cable systems. The size and kinds of pipe and the types of pipe joints used are usually important. Numerous questions relating to the interconnection of gas, water, and cable systems are also of importance. 2. Data on Railway Systems. As regards the data on the railway systems, the following should be determined: (1) Location and capacities of direct current railway supply stations : (2) Location of railway lines and character of service, whether city, suburban, or interurban and the car schedules on different parts of the system. This latter will have a bearing on the length of time necessary for taking readings at various points in order to get representative results; (3) Physical data on railway tracks, such as size of rails, types of bonds and joints, and character of roadbed construction; (4) Practice of the railway company in regard to crossbonding, bond maintenance and bond testing; and (5) Miscellaneous data. In most cases it is desirable to have all-day load curves to facilitate the interpretation of data taken over short intervals at various hours of the day. Where the load varies considerably in different sections of a power house feeding area, it may be necessary to get the load curve on different feeders in some cases. Where a survey is made with the ultimate purpose of correcting electrolysis conditions by applying some method of mitigation, it will be necessary to secure complete data on the magnitude and distribution of the load, the substation and feeder systems, frequency of schedules and probable future growth of traffic. D. COOPERATION IN MAKING SURVEYS Special surveys for determining whether ordinances are being complied with and maintenance surveys can usually be made by any particular utility interested. Complete surveys, however, ELECTROLYSIS SURVEYS 103 which are to be preliminary to the application of electrolysis mitigative measures should preferably be carried out on a cooperative basis by the various utilities interested, including both the railways and owners of underground utilities. It is of the utmost importance that a comprehensive plan of procedure be followed, so that all information relating to the electrolysis conditions of all of the underground structures may be available in the planning and carrying out of the test. In order to bring about such a unification of data and methods, it is necessary to have the full cooperation of all utilities whose properties are affected by electrolytic conditions. In general, this cooperation can best be brought about by having the electrolysis survey and the mitigative measures, if any are to be applied, designed and installed under the jurisdiction of a joint committee representing all of the interests concerned or at the discretion of such committee by an engineer employed by the committee, or jointly by the parties to the survey. II. ELECTRICAL MEASUREMENTS The electrical measurements to be made during an electrolysis survey may be logically classified in either of two ways, namely, (1) on the basis of the structures on which the measurements are to be made, that is, whether on the railway system, pipe system, or cable system, and (2) on the basis of the character of the measurements, whether of voltage, current on, or current leaving a structure, etc. Inasmuch as several or all of the various types of electrical measurements may at times have to be made on all of the affected structures, and since the methods used will be substantially the same regardless of the utility system to which they apply, it appears most logical to follow the latter classification and discuss the subject from the standpoint of the character of the measurements to be made. A. VOLTAGE SURVEYS The number and character of the potential readings required depend on the information desired. As previously pointed out, the readings depend on the thoroughness of the investigation to be made, and it is to be understood that many of the measurements described below would often not be necessary, and in general would be taken only during the course of a complete electrolysis survey. Voltage surveys are here divided into two main classes: (a) Voltage measurements between two points on (a) Importance of Maximum Potential Drop Measurements. Such measurements, when interpreted in the light of other conditions to be discussed later, afford a valuable index to electrolysis conditions generally. It is, further, one of the easiest quantities to determine in an electrolysis survey if the use of telephone lines can be secured. These measurements show in general whether the railway system is properly 'maintained and what lines or sections are most in need of repair and rebonding. When taken in conjunction with the load data, they may be used for an approximate calculation of power losses in the railway return and when studied with due regard to the character and location of railway lines and supply stations, together with the distribution of load, they afford a valuable index as to the need of, or the modification of the track feeder system. It is therefore desirable, as a rule, to take a good many of these measurements as a part of any complete electrolysis survey. (b) Procedure in Making Maximum Potential Drop Measurements. The first step in making measurements of this kind in a city is to determine the location of points between which potentials are to be observed. These usually comprise points on the track most remote from the power supply station as the points of highest potential, and the points on the track nearest the power station as the point of lowest potential. In some cases, however, especially where insulated track feeders are used, the point of lowest potential may be at the point of connection of one of the insulated feeders which may be at a considerable distance from the power station. It is desirable, as a rule, to measure the difference of potential between the points of connection to the tracks of all of the insulated track feeders in order that the points of lowest potential may be determined. It is desirable, as a rule, also to select points intermediate between the points of highest and lowest potential so that the distribution of the potential drop may be determined, as this will give a valuable insight into the location of bad stretches of track and of concentration of return current in the tracks. Reference should be made to a positive feeder map from which a list of power stations and their approximate feeding distances can be determined. Special lines to these points may be run or spare wires may be borrowed or leased from the telephone company. In the latter case, the continuous cooperation of the telephone company is required. Having a list of points to be reached, the telephone representatives can prepare a table showing the terminal boxes and numbers of spare pairs, including trunk lines which are necessary to make a complete circuit between one of the telephone central offices, or other suitable central point where the measuring instruments are to be placed and the points to which measurements are to be made. All measurements can then be made between the point of lowest potential and all other points selected, and between any two points as desired. Temporary circuits are necessary when no spare telephone conductors are available, in which case working conductors may sometimes be used for short periods. In most cases, it is desirable to make permanent connections to the track for maximum voltage drop measurements, but where for any reason, permanent or semipermanent connections to the track cannot be made, temporary connections become necessary and the installation of these temporary connections will require considerable time and expense for labor. It will be found most convenient to bring all the lines from the various points on the track network to a large board on which is mounted a map of the railway system, each wire being fastened to a binding post located at a point on the map corresponding to the point on the track from which the wire comes. Once the correct connection of wires has been verified, one can readily connect the voltmeter to wires leading to any points in the city without possibility of error. While making track voltage measurements, and in fact, all other measurements, it is desirable to arrange to have the test data worked up and tabulated so that it can be carefully studied as the work progresses. This is important because, as pointed out above, the tests to be made during the course of the survey often depend in large measure on the results of preliminary measurements so that by .making a study of the preliminary data while the work is in progress, it is often possible to modify original plans in such a way as to greatly increase the value of the test data. In making electrolysis measurements, it is desirable to take readings at each point over as long a period as practicable. Owing to the great variability of railway loads, it is important to have the readings cover at least one complete cycle of the load, and often several complete cycles are desirable. It is quite common practice to take such readings over a period of one hour, but in some cases, especially on interurban lines and others where the schedule is very infrequent, still longer periods may be necessary. Even where readings are taken over one hour it will generally be necessary for comparative purposes to reduce these readings to an equivalent twenty-four-hour value, and in some cases also corrections have to be made for seasonal changes of the load. This matter will be treated at some length under the discussion of the interpretation of electrolysis survey data. 2. Potential Gradient Measurements. (a) Scope of Term. Under the head of potential gradients will be included all potential measurements between different points on the track or between different points in the earth spaced materially less than the extreme feeding distances within the powerhouse areas. (b) Measurement of Potential Gradients in Tracks. Potential gradient measurements are usually made on the railway tracks, but at times also on pipe systems or even in the earth. The procedure will vary considerably because of the variability of the distances over which measurements are to be made. If the spans are long, telephone wires are the most convenient and the measurements are made in the same way as track voltage measurements described above. Where the distances are relatively short, however, as for example, a few hundred feet or less, a temporary wire between the two points of measurement will usually be most convenient. Connections to the system on which measurements are made will depend on whether the tests are being made between points on the tracks or on the pipe system or between points in the earth. For measurements between points on the tracks or on the pipe system or other metallic structure metallic terminals may be firmly held against the rail or pipe or a wire may be swedged in a slot sawed in the pipe or rail under test. It is sometimes desirable to make potential measurements directly between two points in the earth, though the most common practice has been to take them on the track network. Special situations may arise where potential measurements between various points in the earth are more valuable than those taken on the underground structures. For example, the presence and direction of large transverse currents in the vicinity of important mains can be determined. Buried pipe lines or other conductors at uncertain locations which are discharging current into the earth may be located approximately by earth gradient measurements, there being a reversal or abrupt change in the gradient when the conductor is crossed. In making earth gradient measurements between points relatively close together, it is essential that a pair of non-polarizable electrodes be used if a high degree of accuracy is to be attained. Such electrodes are now in process of development at the Bureau of Standards. The periods over which gradient measurements should be made and the procedure in working up the data during the progress of the survey are governed by the same considerations as discussed above in the treatment of the track voltage measurements. 3. Measurement of Potential Differences. (a) Purpose of Measurement of Potential Differences. Measurement of potential differences are beyond question the measurements most frequently made in connection with electrolysis tests and when their limitations are properly taken into account, they afford a valuable index to electrolysis conditions. It should be emphasized, however, that they are chiefly of qualitative significance, being valuable for indicating the region in which more or less damage to pipes may be in progress, but not giving any definite information as to the rate at which injury to pipes may be progressing. This is due to the fact that the resistivity of the earth and railway roadbed varies with local conditions, that is, a given potential difference that would be practically safe under some conditions of soil resistance would be extremely hazardous in other locations. If this factor is properly taken into account, potential difference measurements may be of considerable value in determining electrolysis conditions. (b) Procedure in Making Measurements of Potential Differences. Measurements of potential differences between adjacent structures should be made at many points between fire hydrants, lamp posts or gas or water services and tracks, lead cable sheaths and tracks, lead cables and accessible portions of pipe systems, between any two pipe systems that approach closely to each other, and where practicable between cable systems and the earth. In making contacts on fire hydrants and lamp posts, care should be taken to make contact with the pipe itself, rather than the housing. These measurements, between cable systems and earth, if properly taken, afford the most valuable index of electrolysis conditions, but unfortunately, they are the most difficult to secure, and unless taken by a competent engineer, thoroughly familiar with the possible sources of error involved, they may be worthless or actually misleading. These measurements when taken should be made throughout a large part of the piping or cable networks including any regions in which there is reason to believe that stray current may be leaving the affected structures for the earth. Since the structures between which potential difference measurements are made are usually close together, short leads only are required, short lengths of lamp cord or other flexible wire being most commonly used. Either temporary or more or less permanent connections to metallic structures may be made, according to whether readings are to be taken over a short or long period and whether they are to be repeated at some future time. When measuring potential differences between pipe or cable systems and the earth, it is important to use an auxiliary earth electrode that is known to give a very small galvanic potential against the metal of the structure under test. For lead cables a piece of ead sheath is entirely satisfactory. In the case of iron pipes thel problem is more difficult because of the variability of iron and the possibility of complication due to oxidation of either the pipe under test or the auxiliary iron electrode. When such readings with iron electrodes amount to only a few tenths of a volt they should not be regarded as reliable unless taken over a period including that during which the railway power station is shut down, owing to the possibility of galvanic voltages being of this order of magnitude. 1. Scope and Importance of Current Measurements. Under the head of current measurements are included all observations of current flow obtained by ammeter readings, or by a potential drop on a conductor, the resistance of which is approximately known. They include measurements of current flowing from subsurface structures into the earth. Current measurements on undrained structures made both before and after a change in the railway system or the application of other mitigative measures afford considerable information as to the change in electrolysis conditions. Owing to the great variety of conditions under which it is at times necessary to measure current, as in copper feeders, rails, pipes, cable sheaths, and even 2. Measurement of Currents in Feeders and Rails. (a) Purpose of Measuring Feeder and Rail Currents. Measurements of current in track feeders and rails are usually made only when it is desired to check the current distribution in a network of tracks. Current measurements on the track will show the points at which additional track feeders are required in order to limit potential gradients in the track as well as the amount of current that must be taken off at each point, and consequently the sizes of feeders required. The same result can be obtained with sufficient accuracy for most practical purposes by the use of a "spot map" on which are shown the average distribution of cars and their corresponding loads. Further, by measuring current in different rails in the track, local bad bonding will be revealed since unequal distribution of current always indicates relatively high resistance in the rails carrying the lower currents. In fact, some engineers regard the measurement of the relative current in the rails at a number of points as the most reliable way of obtaining in a short time a good idea of the condition of track bonding. (b) Procedure in Measuring Current in Feeders and Rails. The most accurate method of measuring current in a feeder of rail is of course, afforded by inserting an ammeter shunt directly in series with the feeder or rail under test. However, in practice it often happens that in the case of negative feeders ammeters or shunts are not provided and can be inserted only with difficulty, and in the case of rails this is impracticable. The most common method, therefore, of measuring current in such structures is to measure the potential drop on a known length of cable or rail and to calculate the current from this potential drop and the resistance of the conductor. Such measurements of current can be made on copper cables with high accuracy and on steel rails the results can usually be relied upon to 10 per cent or better, which is sufficient for practically all purposes. In making the current calculations it is customary to consider the resistivity of the copper at 10.7 ohms per circular mil-foot, and that of steel rails to be 0.0003 ohm per pound-foot, this latter being equivalent to a resistance of 0.000009 ohm for one foot of rail weighing 100 pounds per yard. In practice it may be expected, however, that the resistance per pound-foot may vary between the values of 0.00027 and 0.00033, or about ten per cent each way from the mean values here given. Table 5 in the appendix will be found convenient for calculating the current in rails of various weights. (a) Purpose and Importance of Pipe Current Measurements. The measurement of current in pipes and lead cable sheaths is important for a number of reasons. Heavy currents in pipes are often objected to by owners of pipe networks, particularly gas and oil pipes owing to the fear that trouble may result from ignition of gas or oil due to arcing when two portions of the pipe network are separated, and also due to arcing between adjacent pipes in confined air spaces such as cellars where there may be considerable potential differences due to such currents. In some cases also, excessive heating has resulted due to the presence of abnormally large currents on small pipes, and the presence of such heavy currents may make it very difficult to prevent local interchange of current between neighboring structures. Heavy currents on lead power cables are also objectionable because the heat generated in the lead sheath may limit considerably the carrying capacity of the conductors within the sheath. In view of these factors, it becomes important to measure currents on pipes and cables in many instances. Relative current measurements on pipe and cable systems made before and after the application of mitigative measures are also valuable as an index of the effectiveness of the mitigative system employed. This is true, however, only when there has been no installation of new drainage connections or change in existing drainage connections on the affected structures. (b) Selection of Points of Measurement. In general in selecting points for making current measurements, it is desirable to secure some points at which maximum current flow may be anticipated, and also 'a considerable number of points that may be regarded as representative of conditions generally. As a rule, the maximum current in an undrained pipe network may be expected in pipes extending approximately parallel to the tracks and near the neutral or slightly positive areas. Also numerous cases will usually be found in any network in which one or at most, a few mains serve as connecting links between local networks, and such mains usually will be found to carry much larger currents than mains forming a portion of the network. On drained pipe systems, the maximum currents will as a rule be found in the pipes extend- ing in all directions from the points at which drainage cables are connected. It is impossible to lay down rules more detailed than the above for the selection of points at which measurements should be made. Experienced judgment should be followed in all cases. (c) Methods of Measuring Current Flow in Pipes. Four general classes of methods of measuring current flow in pipes and other metallic structures have been used. The one that is perhaps the most frequently used is the ordinary drop-in-potential method in which the voltage drop on a measured length of pipe, not including a joint, is taken and the current calculated from this voltage drop and the estimated resistance of the portion of the pipe across which the potential drop is measured. Complete tables for the resistance per unit length of the various sizes and kinds of pipe in common use are given in the appendix. Careful tests made on a great variety of specimens of pipe of different kinds, indicate that measurements of this kind can be depended upon to give results accurate to within about 10 per cent, which is ample in most cases encountered in practice. A second method, used in special cases where greater accuracy than is possible by the drop-in-potential method is necessary, is the method for calibrating the pipe either by sending a known current through it superposed on the railway current already flowing in the pipe, or by shunting through an ammeter, certain portions of the current actually flowing in the pipe. These methods have taken various forms, one of the most important of which is described later. A third method consists in the use of what is known as a direct current ratio relay in a manner somewhat analogous to the use of a current transformer on alternating current circuits. This is useful only where currents of fifty amperes or more flow on the pipe. A fourth method consists in surrounding the pipe with an iron ring containing an airgap and providing means for measuring the magnetic flux set up across the airgap by the current in the pipe. Several different methods are available for making these measurements. The last two methods may also be used for calibrating the pipes, thus eliminating in some measure the uncertainty arising from the calculation of the pipe resistance. It is questionable, however, whether in most cases the greater accuracy thus achieved is sufficient to warrant the use of the more complicated methods. two of these methods. Drop-in-Potential Method. This method consists in connecting potential terminals to a section of pipe a few feet apart and measuring the millivolt drop, and in calculating the current from this millivolt drop and the resistance of the section under test. It is very widely used, and its great simplicity adapts it to work of this kind. This method has the great advantage that it can not only be used with an indicating instrument but also with a recording instrument unless the currents are very small, and thus not only a permanent graphic record be obtained, but also the average value for a given period can be determined. The tables appended to this report are based on careful measurements made by the Bureau of Standards on several hundred specimens of iron and lead pipes from various sources, and they are accurate enough for all practical purposes. In using this method it is necessary to make an excavation at the point where the measurement is to be taken and attach two leads to the pipe, preferably as far apart as practicable without including a joint. This connection may be made in numerous ways, but perhaps the best way is to insert at each point a corporation cock in which a rubber covered wire has been soldered. If the connections are to be permanent, the leads should be brought underground to a point inside the curb and there terminated in an ordinary service box or other suitable receptacle so that they will be protected from traffic but readily accessible for repeating the measurement at any time. One method of making such connections and protecting the leads is shown in Fig. 21, and another which has been very successfully used in paved streets is shown in Fig. 22. It is also important that the junction between wire and corporation cock be protected by painting with a heavy asphalt or similar paint. If the current on the pipe is large enough to be of practical significance it can be read with an ordinary sensitive millivoltmeter either indicating or' recording. In special cases where the current is extremely small, only a high sensitivity indicating millivoltmeter or even a portable galvanometer can be used. Calibration of Pipes. One of the methods most commonly used for the calibration of pipes involves superposing a current on that already in the pipe and measuring the change in millivolt drop due to this superposed current. This method, originally used by Professor B. F. Thomas was first described by Dr. Carl Hering in the Transactions of the American Institute of Electrical Engineers for June, 1912. Theoretically, this method should give very high accuracy, but it should be borne in mind that the resistance of the pipe thus determined is correct only for the conditions under which the measurement was made. Iron pipes, especially wrought iron and steel pipes, have a high temperature coefficient of resistance and variations in this resistance due to temperature changes between winter and summer may introduce variations of .five per cent or more in this resistance. For this reason, it is very doubtful whether the complication involved in the use of this method is justified, but it has been used by some engineers. Further, owing to the presence of rapidly fluctuating railway currents on the pipes, the application of this method is often difficult. Use of a Direct-Current Ratio Relay. An instrument known as the direct-current ratio relay for measuring current in conductors which cannot be opened for the insertion of ammeters or shunts has recently been devised. The ratio relay permits the measurement of variable unidirectional currents of relatively large magnitude only, on an ordinary direct current ammeter. This instrument gives very good results when very large currents are being measured, but in its present form it is not suitable for measuring currents of a few amperes, such as are most frequently encountered in electrolysis testing. 4. Comparing Currents Under Different Conditions. In case the object in view is the determination of relative current in pipes under different systems of mitigation, this can be done simply by measuring potential drops between services or between adjacent fire hydrants. In general, the resistance may be regarded as sufficiently constant so that the currents under the two conditions of test will be proportional to the voltages at corresponding test stations. tures to Earth. It is extremely desirable to measure the amount of current flowing from a particular portion of a pipe or cable network directly into the earth. In fact, if such measurements could be made conveniently and with sufficient accuracy they would be by far the most important and valuable measurements that could be made in an electrolysis survey, since this measurement would afford the most accurate measure of the rate at which damage is progressing. Unfortunately, there has not been available up to the present time, any very satisfactory method of measuring such current flow except in very special cases. Four different methods have been proposed under special conditions for making this measurement. These are: (a) differential current measurements; (b) the use of a Haber earth current collector; (c) the measurement of polarization potentials; and (d) the combined measurement of potential drop and earth resistivity. The first of these is discussed below. The second and third have been found impractical and the last is still under development. (a) Differential Current Measurement. This method of measuring current flow from a pipe to earth can be used to advantage where it is desired to measure a current discharge that is comparable in magnitude with the total current on the pipe. If the measurement is made at two points on the pipe by the potential drop method, uncertainties- in the measured values may be too great to permit an accurate determination of discharge, but if the pipes are carefully calibrated at the points at which the potential drops are measured, fairly accurate results can be obtained, provided the difference in current is as mtlch as ten or fifteen per cent of the total current flowing in the section of the pipe under test. In making current discharge measurements by this method, it is necessary to make sure that there are no service pipes or drainage feeders connected with the portion of the pipe between test points through which current may flow. Electrical tests are made on railway tracks chiefly for three purposes — first, to locate the cause of bad electrolysis conditions that may have been encountered — second, to serve as a guide for the systematic maintenance of the railway track network, and third — to be used as a guide in designing an electrolysis mitigation system. Three methods of determining the condition of the track system have been extensively used, as follows : (a) Inspection. This method of testing bonds by a simple inspection is one which has been used much more extensively in the past than at the present time, but it is unfortunately still very frequently used in open track work. It consists chiefly in going along the track and making superficial inspection of the bonds and if they appear mechanically good, the assumption is made that the bond is in a satisfactory condition. It cannot be too strongly emphasized that any examination of bonds by this simple method of inspection should be regarded as a poor makeshift, and some more reliable method should always be used. (b) Use of Portable Bond Tester. There are in use at the present time a number of portable bond testers operating on the principle of a slide wire bridge, a portable milli voltmeter being used to determine when the bridge is balanced. In the use of this instrument the voltage drop across the joint is compared directly by the bridge method with the voltage drop on a definite length of rail directly adjacent to the joint under test, so that the resistance of the joint is measured in terms of an equivalent length of rail. This method has the advantage of simplicity as it can be operated by one man, and while somewhat slow and tedious.it often affords a very satisfactory method of testing bonds. (c) Autographic Method of Bond Testing. — A method that has been used extensively in recent years for testing the bonds in railway tracks is what is known as the autographic method. This method is like that of the portable bond tester in that it is based on a comparison of the potential drop across a certain length of rail, including the joint, with that across an equal length of adjacent solid rail. The two readings are taken and automatically recorded within a fraction of a second, and during this short time, the current in the rail may be regarded as practically constant. The method, however, permits of a correction in case the current should vary appreciably between two readings. The autographic method has several advantages, chief of which are as follows: any particular period. The apparatus for this method of testing is quite expensive as a special car is required and sometimes another car is used to haul the test car. Owing to the much greater rate at which bonds can be tested by this method, however, the total cost on a large job will not necessarily be greater than with manual testing. addition to testing the joints discussed above, it is important also to test the condition of cross-bonds between rails and of jumpers spanning special work. This can perhaps best be done by means of a low reading voltmeter having two ranges from .01 to one volt, the test being made by going along the track and measuring the potential difference between the various rails at frequent intervals, and also across various sections of special work. Underground Structures. (a) Importance of Tests of Roadbed Resistance. — The determination of the average resistance of the leakage path between railway tracks and surrounding earth is often very desirable, particularly where it is necessary to determine what overall potential drops may safely be permitted in the track return. It will be evident that if the resistance of the leakage paths is very high, it will be safe to allow higher potential drops in the track than if the leakage resistance be low, although the voltage drop which may be considered safe is not directly proportional to the average resistance of the leakage path. (b) Differential Method of Measuring Roadbed Resistance. Fig. 23 illustrates the method employed for making measurements on roadbeds where it is found impracticable to isolate a limited section of the track. After the car traffic has been withdrawn for the night, a portable storage battery is connected, as shown, between the four rails of the track and a fire hydrant on a relatively large main. An ammeter and a regulating resistance are included in the circuit. A ten volt storage battery or a low voltage generator is employed for this purpose and a constant current of from twenty to forty amperes is maintained during the period of the test. The current entering the rails will flow away from the test station in both directions, as shown by the arrows. Leakage will take place to the earth and all of the current will be picked up by the waterpiping system and returned to the negative pole of the battery. If now a milli voltmeter be employed to measure the potential drop on a short section of the track at Station A, and again at several thousand feet distant at Station B, the loss of current from the rails between the two stations can at once be determined, provided the rails are of the same weight and resistivity at the two stations, and provided further, that the battery current has remained constant. Now, if the potential difference between the section of track under test and the earth at some distance from it easily be computed. While the principle involved in such a measurement is extremely simple, the practical difficulties encountered make accurate and reliable results very difficult of attainment, and it is only by many and repeated measurements that reliable data can be secured. The difference between the currents at Stations A and B is the quantity which must be determined, and as this is usually a small fraction of the total current, even over a distance of one-half mile, a slight error in the measurements would be exaggerated in the result. Errors might result from inaccurate readings or from different rail weights or resistivities. It is necessary, therefore, to make not only one measurement on each of the four rails at both stations, but measurements should be made at several slightly different locations at each station. Tn determining the average potential difference between the track and the earth, voltage measurements should be made to as many different underground structures as can be found in the vicinity. Measurements made to the fire hydrants along the track are likely to give erroneous results, due to the gradient on the water main caused by the return current. The most reliable and consistent results are obtained by driving a ground rod into the earth at a distance of not less than 200 feet from the track and measuring the potential difference between it and the track with a high resistance voltmeter. (c) Isolation Method of Measuring Roadbed Resistance. When it is desired to make measurements in localities where no piping systems exist, the method just described cannot be employed. These roadbeds are usually of open construction and it is therefore a comparatively simple matter to remove the joint plates and bonds from four joints, thus isolating a section of track on which accurate and reliable measurements can be made. Fig. 24 shows the arrangement of the apparatus for this test. A section of track from 100 to 500 feet in length is isolated from the remainder of the track network by removing the bonds and joint plates as shown. All cross bonds between this test section and the adjacent track must also be cut. A battery of three or four dry cells is connected between the test section and the remainder of the track network, which, being of great extent, is considered as a remote ground of negligible resistance. A low-reading ammeter and a voltmeter give the current flowing and the potential difference between the section of the track under test and the leakage paths at the ends of the section is practically eliminated. The resistance so found is for a single-track roadbed but in the open type of construction the resistance to earth is concentrated largely in the ties and therefore the resistance of double track can be taken as one-half that of single track. This is not true when the rails are imbedded in earth or concrete. In this case the resistance of a double track may be taken as about seventy per cent of that of a single track if only approximate results are required. This method of measuring roadbed resistances necessitates working at night, as does the differential method, since it usually requires several hours to remove and replace the bonds and joint plates on four joints. In making electrolysis surveys, it is often necessary to determine whether or not there are any considerable number of high resistance joints in a given portion of a pipe network. This has been a particularly important test in making investigations of joint electrolysis in pipe systems, and may often be useful in determining upon the method of protection to be used in particular cases. High-resistance joints may be most conveniently located by means of potential drop measurements along the pipes. The method usually followed is to drive bars down until they come in contact .with the pipe and measure the potential drop on the pipe at such points, the spacing of the points being usually about 100 feet. A series of such measurements is made throughout the entire length of the pipe and the relative magnitudes of the voltage drops on adjacent sections would indicate which, if any, is affected by high resistance in the pipe line. When it has been determined that any particular hundred-foot length includes one or more high resistance joints, this section can be further subdivided by exactly the same procedure until a relatively high drop is obtained between two points less than a pipe length apart, which must include a high resistance joint. By comparing the drop across the the high resistance joint with the drop in a measured distance on continuous pipe, the resistance of the joint in terms of equivalent feet of pipe can be obtained. Conditions are often encountered in which stray currents on pipe networks may come from any one of two or more railway lines, and it is important to determine from which line the current is derived. This can be determined in either of two ways. One method is to connect a measuring instrument of the recording type to the pipe under test, which may be connected either to indicate the current flow along the pipe or the potential difference between the pipe and the earth. With the instrument thus connected, a record is obtained, while all railway systems are operating under normal conditions. Then one of the railway systems is shut down for as long a period as practicable. If the shutting down of the plant makes a marked difference in the record, it is an indication that a large part of the stray current at least comes from that particular point. By shutting down the different systems in rotation, a fairly definite knowledge of the source of the stray current may be obtained. Sometimes it will be found that the shutting down of one plant increases the current flow in one direction, while shutting down another plant may give rise to a large current flow in the opposite direction, both currents being larger than when both plants are running. This will indicate that the stray current from the two systems tend to neutralize each other, thus giving rise to better conditions in certain localities than those which prevail when either system is operating alone. The other method of tracing the source of stray current in any particular case consists in the use of two or more recorders, one of which makes a graphic record of the current or voltage, the source of which is to be determined, while the others are used to make simultaneous records of the loads on the various power supply stations which may possibly affect the area in question, or more particularly the loads on certain feeders from those stations. In most cases there will be sufficient similarity between the chart of the stray current and some one of the feeder or station load charts to establish quite definitely the source of the stray current. 5. Location of Unknown Metallic Structures or Connections. It is often desirable to locate metallic connections between pipes and various other structures, such as railway track returns which may often exist without the knowledge of either the pipe or railway company. Two methods are available for doing this: One consists in connecting an external electrical circuit between convenient points on the pipe system and railway system, and sending between them either an alternating current of audible frequency or a direct current interrupted, at audible frequency. An exploring coil is then carried along the pipe system in such position that the alternating or pulsating magnetic field produced by the current superposed on the pipe current will induce an electromotive force in the coil. This can be made audible by the use of a telephone receiver. By this instrument, the path of the current can be traced and in most cases the location of concealed connections to the pipe can be determined. The method works very satisfactorily on relatively simple pipe networks, but in very complicated systems where there are a great many pipes laid in the street it becomes relatively difficult to trace out any particular structure. A method that has been more recently developed and which is considerably more simple than the above, consists in doing away with the additional current superposed on the pipe network, and using the exploring coil and telephone to listen to the commutation note in the railway current carried by the pipe. This method is much to be preferred where the pipe currents are large enough to give sufficient sensitivity. In some cases, however, where the currents on the pipe are very small, the first method may have to be resorted to. SURVEYS No definite rules of procedure can be laid down for the interpretation of the results of electrolysis surveys that can be used except by engineers thoroughly familiar with all the factors involved. The significance of any particular set of readings is so dependent upon other conditions that all factors must be taken into account or else the conclusions are likely to be in error. However, it is desirable to point out certain principles that must be kept in mind even by the experienced engineer in order to arrive at correct conclusions. 1. Maximum Voltages and Track Gradients. These measurements, when considered in the light of a full knowledge of all conditions, give valuable data on the condition of the railway track system and the concentration of return current on certain sections of track. They also are valuable when considered in the light of the load on the different lines, as they offer a fairly accurate indication of the track losses and the necessity for the use of additional track feeders. When such potential measurements are taken over relatively short lengths of track, such as 1,000 or 2,000 feet, the comparison of such measurements on adjacent sections of track will often reveal bad places in the track that are in need of rebonding.- Potential difference readings between pipes and railway tracks and between various underground structures are not a quantitative measure of the danger to the affected structures. These readings are valuable in pointing out the general areas in which trouble may be expected to occur and in which more careful search may be made if desired. They are, however, of qualitative significance only. The current leaving a structure for the earth in any locality, which is the real cause of the electrolysis damage, is a function not only of the potential differences but of the resistance of the earth paths. This has been shown to vary throughout extremely wide limits, so that the measurement of potential difference gives no definite quantitative measurement of the extent of the hazard to the pipes. Such measurements are very valuable and have an accurate quantitative significance, however, when used to determine the relative electrolysis conditions under different systems of mitigation. If, for example, under a given set of conditions a considerable number of potential difference measurements are made between the various underground structures and then a change is made in the mitigative system, and the same measurements repeated, the two sets of readings may be used to represent the comparative hazard in the two cases. This is true only if the mitigative measures under test are applied exclusively to the railway return system. High potential differences between gas and oil pipes and other metallic structures with which they may come in contact are objectionable especially in confined spaces, such as basements in which explosive mixtures may be encountered. This is because a transient contact between the two structures may cause an arc which may result in fire or explosion. If all the current that flows on the pipe is discharged directly into the earth, then the total corrosion will be approximately proportional to the current flow. Even here, however, the rate of damage to the pipes is not only a function of the total weight of metal corroded away, but of the distribution of such corrosion as a result of pitting or of localized discharge from one system to another where they approach close to each other. Further, if there are metallic connections either known or unknown between portions of the pipe networks and the railway tracks, which carry off a large part of the current on the pipe through metallic paths, the total amount of corrosion cannot be determined by measurement of the current flow. For this reason current measurements on pipes should likewise be regarded as having only a qualitative significance in so far as any absolute hazard to the pipes is concerned. If, however, the pipes have no drainage connections and changes are made in the railway track network, the corresponding changes in the currents on the pipes may, if a sufficient number of readings have been taken, indicate the relative improvement in the electrolysis conditions. 2. Relation of Current to Fires and Explosions. In interpreting the significance of current measurements on gas or oil pipes, due account should be taken of the possibility of fires and explosions due to arcs formed either when pipes are disconnected, or when pipes make transient contact in confined places such as cellars. No definite information is at present available as to what limiting currents on such pipes may be considered safe, but it is generally recognized that the presence of currents on gas and oil lines is more objectionable than in the case of other pipes. FLOWING FROM STRUCTURES TO EARTH The only accurate criterion of electrolysis damage is the intensity of current flow to earth at any point on the pipe or cable. If an accurate measure of this current flow from the pipe at any point could be made, it would come nearer giving a true indication of electrolysis conditions than any other measurement. At the present time there is no practical means available for making such measurements. The development of a simple, inexpensive and accurate means for measuring such currents locally, constitutes one of the chief needs in the field of electrolysis testing at the present time. D. USE OF REDUCTION FACTORS In many cases it is not practicable to take readings of current and potential at any point over a sufficiently long time to get all day average values of the readings at that point. Such readings should always be taken for as long a time as circumstances permit, but in making electrolysis surveys, it is usually necessary to take a large number of readings scattered over a wide area so that some of the readings can be continued only for a comparatively short time. Such short-time readings cannot, in general be used directly as a basis for determining electrolysis conditions and in order to interpret properly the results of the survey, the readings must be reduced to some common basis, as for example, either the twenty-four-hour average, the operating-day average, or the average for the hour of the peak load. Each of these bases has certain advantages and disadvantages depending partly on the individual conditions, and the method of procedure will often differ, depending on the method to be followed in interpreting the results. All are affected by such factors as rush or light days, unusual weather conditions, electric heaters in cold weather, morning and evening peak loads, and other causes, and these factors must be considered. The great unreliability of short-time readings for determining electrolysis conditions is especially noticeable when comparing the load curve of a line having a 5, 10, or 15 minute schedule with that of hourly interurban service, or when comparing that of a station having a 45 per cent load factor with one having a load factor of 10 per cent. Because of this great variation and uncertainity in short time measurements and for the purposes of interpretation and comparison, it is desirable that long time readings be obtained, but if this is impossible, all short-time readings should be reduced to values for some representative period, preferably the twenty-four hour average. Experience shows that in the majority of cases, short-time readings of from 15 minutes to an hour, taken on a city network between the hours of 10 A. M. and about 4 P. M., approach rather closely the twenty-four-hour average values, and it is found permissible to neglect the use of reduction factors in connection with readings taken during this period of the day. When, however, readings are taken at any time during the morning or evening peak, or after nine or ten o'clock at night, it is necessary to use a proper reduction factor if anything like reliable conclusions are to be reached. In general, it seems preferable to reduce such E. EFFECT OF REVERSALS OF POLARITY Throughout a large portion of the territory served by a grounded railway system, it will be found that the potential differences between pipes and earth frequently reverse in direction, the pipes becoming alternately positive and negative to earth with periods varying from a few seconds to several minutes or even longer; and special consideration has to be given to measurements in such places in order that even an approximate estimate of their significance can be made. In general, four different classes of conditions have to be recognized in interpreting these measurements as follows : 1. Polarity of Pipes Always the Same. If the pipes are always of the same polarity, as, for example, always positive to surrounding structures, it is, of course, the arithmetical average value that should be used in judging the significance of the readings. 2. Polarity of Pipes Changing with Long Periods of Several Hours. If the pipes at any point are continuously positive for a period of several hours, and then of opposite polarity for a succeeding period of 'some hours, a condition which frequently exists in localities where a substation is operated during only a portion of the day, there will in general, be relatively very little protective effect due to the period when the pipe is negative or neutral to earth, and the actual corrosion is most nearly indicated by the arithmetical average value of the voltage or currents during the hours in which the pipe is positive to earth, this, average, of course, being reduced to the twenty-four-hour average basis. Thus, if a given pipe is found to be positive to the earth or other neighboring structures by a given amount for a period of twelve hours, and either negative or at zero potential for the remaining twelve hours of the day, the actual amount of corrosion that would occur would undoubtedly be nearly equivalent to that which would result if the potential at the same point was maintained half as great for the full twenty-four hours. corrosive process is in large measure reversible, and the actual amount of corrosion comes more nearly being proportional to the algebraic average of the applied potential than it is to the arithmetical average during the total time the pipe is positive. In all cases, therefore, where the polarity of the pipe is continuously reversing and the period of reversal does not exceed five or ten minutes, the algebraic average of the voltages or currents should be given far greater weight than the arithmetical average values during the positive period. Minutes to One Hour. Under these conditions, neither the algebraic nor the arithmetical average of the applied potential or current flow gives an accurate index of the amount of corrosion. For the shorter period the algebraic average comes more nearly being the proper criterion, while as the period increases in length the arithmetical average tends to give a better indication of the extent of the resulting corrosion. However, even where the period of reversal is as long as one hour, the corrosive process is, under most conditions, to a considerable extent reversible and some allowance in interpreting the results should be made. IV. SELECTION OF INSTRUMENTS In this section descriptions are given of the apparatus and tools which are essentially special for electrolysis work. The tools ordinarily used for handling wires and making good contacts in electrical work will also be needed, but no special description or listing of them seems to be necessary in this place. A. PORTABLE MEASURING INSTRUMENTS The portable measuring instruments required in electrolysis survey work include voltmeters, milli voltmeters, and ammeters. Separate instruments of each kind, can -of course, be carried, but it will usually be found more convenient to employ the special portable instruments which have been designed particularly for this work. Three such instruments which the Weston Electrical Instrument Company manufacture for this class of work are as follows : Model 1, combination millivoltmeter and voltmeter, has its zero in the center of the scale, and reads in both directions. Ranges of 5, 50, and 500 millivolts and of 5 and 50 volts are convenient. It is made with a specially high resistance of from 500 to 600 ohms per volt so that the 5 millivolt range has a resistance of about 3 ohms. These high resistances minimize errors due to resistances of leads or contacts. For work on the street, a dust-proof case should be specified. Ordinary switchboard shunts provided with binding posts and adjusted for 50 millivolts may be used to make this instrument serve as an ammeter. Convenient ranges for these shunts in electrolysis work are 5, 50, and 500 amperes. Model 56, combination volt-ammeter has its zero in the center of the scale and reads in both directions. Ranges of 10, 50, and 500 millivolts, 5 and 50 volts and up to 100 amperes are convenient. Model 322, millivoltmeter, has the zero at the left of the scale and a full scale deflection of one millivolt. Owing to the low range and extremely light movement it must be used with a great deal of care. It is useful for determining very low differences of potential such as drops along short sections of pipe or feeder for determining current flow. The center scale feature referred to in the description of these instruments is an important one in electrolysis work, as it is not always possible to determine in advance the direction of current or potential, and readings may also vary from positive to negative values during the making of observations at many testing points. When simultaneous readings have to be taken at two or more testing points, it is important to use similar instruments at all points. If dissimilar instruments are used, their periods may differ and with the fluctuating voltages and currents encountered i\|i much of this work, accurate simultaneous measurements cannot be made unless the instruments used have the same periods. B. RECORDING INSTRUMENTS Recording measuring instruments are usually arranged to give 24-hour records without change of chart. By using a sensitive millivoltmeter in the recording instrument and providing it with a number of voltage ranges as well as with suitable shunts, a single instrument can be- made available for taking all of the voltage and current readings required in electrolysis work. The type of Bristol recording instruments used for electrolysis work makes a record upon a smoke-chart which has to be treated subsequently with a fixative supplied with the instrument. The Bristol instruments are regularly made with a clock supplied with a changing lever so that the disk can be made to rotate either in one hour or twenty-four hours. valuable in the detailed study of changes which take place during short intervals and where a record covering more than one day is required. The clock will operate for a week with one winding. Several other manufacturers make portable recorders suitable for some electrolysis measurements. In either type of instrument, center scale zeros should be called for so that variations between positive and negative values will be recorded on the chart. A. GENERAL DISCUSSION Much detailed information is necessarily gathered in the course of an electrolysis survey. It is desirable to prepare in advance of the work for the convenient recording of these data upon suitably arranged testing sheets, which either have upon one line or upon one sheet, as may be necessary, all of the data collected at any stated testing point during a single period of observation. Several typical data sheets prepared for recording observations made upon piping and cable systems are given in the appendix to this report as suggestive of possible arrangements for report sheets. The data thus collected can usually be best arranged for study if they are transferred to a map showing the system or systems included in the tests, and indicated thereon either in numerical form or through some graphical representation. It is desirable to indicate positive and negative relations by making records on the maps in different colors. Apart from the data obtained through observations in the work of the electrolysis survey, the records obtained relating to the systems under observation should include the following: B. ELECTRIC RAILWAYS 1. Maps showing locations of sources of power supply, tracks and negative feeders and other connections between bus-bar and track; also locations of positive feeding connections to trolley and all trolley feeder sections. standards of bond maintenance. 4. Information as to any direct ground connections applied to the railway return system, and any special track features which may affect the flow of stray currents. and branch line pipe sections. 3. Information as to -method of joining service connections to main supply pipes including metals used for the building connection pipes and the depth to which such connections are buried. 4. Location and description of any protective devices such as insulating joints; also any drainage connections which may have been made a part of the piping system. 5. Information as to methods of attachment and construction employed in carrying pipes over highway or railway bridges or under water courses, swamps, etc. D. CABLE SYSTEMS 1. Maps showing locations of all conduit routes and giving number and sizes of cables in place therein or the total crosssection of lead sheaths expressed in equivalent copper, also locations of power stations, sub-stations or other centers from which cables radiate. Complete data on bonding practice should be secured. 2. Locations, routes and sizes of all drainage connections attached to cable systems, also locations of all insulating joints in cable systems, of any junipers which may be run to establish a metallic circuit across an insulated gap in the cable system and of any conductors run to reinforce the carrying capacity of the cable system for stray currents. 3. Information as to methods of attachment and construction employed in carrying cables over highway or railway bridges or under water courses, swamps, etc. 1 . Locations of structures with respect to electric railways. 2. Information as to methods of construction employed in carrying electric railways, pipes and cables across bridges and particularly as to whether any of these other structural systems make electrical contact with the metal structure of the bridge. for pipes, etc., in the soils of the area. It is desirable that in the preparation of records and of reports, consideration be given to the necessity of their perpetuation. All records which will be of permanent value in connection with the continued study of electrolysis conditions in any particular area in order to make sure that injurious changes in conditions do not occur, should be prepared in a permanent form capable of withstanding considerable handling. VI. TABLES The tables in the appendix are to be used for calculating the current flow in different kinds and sizes of pipes from the measurement of the millivolt drop on a definite length of pipe. These tables were prepared by the U. S. Bureau of Standards from a large amount of test data taken on representative specimens of pipe from a number of different manufacturers. The figures for wrought iron pipes represent the results of tests made on 86 separate specimens of pipe. Those for steel pipe are based on tests of 64 specimens, and those for cast iron are based on test data from 22 specimens of pipe from a number of different foundries. The tables for lead pipe are based on test data taken on 27 specimens ranging from one-fourth to two inches in diameter, all of which, however, were obtained from one manufacturer. It is believed, however, that these figures can be used for all lead service pipes with sufficient accuracy for most practical purposes. These tests showed that the resistance of cast iron, wrought iron, and steel pipes can be estimated from these tables with an accuracy of at least 10 per cent, and in most cases the results will be even better than this. The tests showed an average resistivity for steel pipe of 215.8 microhms per pound-foot, for wrought iron pipe 209.3 microhms per pound-foot, and for cast iron the figure is 1,227 microhms per pound-foot. These average values have been used in the calculation of the tables. Tables for lead sheathed cables have not been included in this report, owing to the large number of different sizes and thicknesses of sheaths used for signal and power cables, as well as a variation in resistivity with different sheath compositions. A. GENERAL In the study of the practice followed in European countries for handling the problem of electrolysis, it has appeared impossible to secure reliable and satisfactory information merely by correspondence and consultation of published reports and regulations. Moreover, the several independent reports made by American investigators before the foundation of the American Committee, were made from the standpoint of some special industry rather than from the broad and comprehensive viewpoint of this Committee. Under these circumstances the necessity for an independent personal investigation was evident. The Chairman of this sub-committee, after consultation with its members and with the general Chairman, decided to visit several European countries during the summer of 1914. Information concerning important foreign cities and authorities, and papers, suggestions and references were obtained from Mr. H. S. Warren and the late Prof. Albert F. Ganz. Also the officials of the Bureau of Standards were consulted when the field of inquiry and special points to be looked after were carefully discussed. An effort to have the Bureau of Standards appoint a representative to join trie party failed on account of their extensive engagements. However, the party included an engineer thoroughly conversant with electrolysis measurements and surveys. The visiting Committee spent June and July in its investigation, covering Germany, Italy, France, and England. In each country an effort was made to take measurements and to collect data and surveys, also to interview the most prominent people in each of the different interests affected by the problem of electrolysis. In each case extended conferences were held with the engineers most familiar with the problem and its details, either in their capacity of specialized consulting engineers, or as officials of corporations or public authorities directly concerned in the surveys, disputes, or administrative measures relating to electrolysis. EUROPEAN PRACTICE 135 Great Britain alone. However, it is believed that the same circumstances have retarded development so that the conditions observed in 1914 correspond substantially with those existing at the present time. It should be borne in mind, however, that references in this report to the current status of committees or commissions, and of legislation or litigation, will unless otherwise noted, refer to the ;ummer of 1914. The results of the Sub-Committee's investigations are summarized in the paragraphs immediately following, classified by principal topics. This is followed by statistical information, details of design and operation, and rules and regulations in effect in different European countries. 1. Germany. There are no laws specifically relating to electrolysis, and so far as could be ascertained, there are no local ordinances dealing with this subject. The common law of most of the states prescribes that all of the conditions under which a corporation is to operate must be contained in the original .grant and any later grants for extensions. The law requires that due publicity be given to any request for a franchise or for extensions of lines, so as to afford all parties who may be affected an opportunity to place on record any limitation they may desire to propose, or to request provisions concerning possible damage, before the concession is granted to the applicant. Hence, a pipe owning company organized subsequently to the existence of an electric railway is held to have assumed the risks existing at the time of its organization, and it therefore cannot claim damages from this railway on account of electrolysis unless the original franchise to the railway contained a clause regarding such damage. The foregoing applies to private corporations. Municipal corporations, on the other hand, do not assume the legal obligation to protect existing systems against the effects of electrolysis. In such cases, pipe owning companies already in existence are deprived of the privilege of demanding that protection against possible future damage which would be accorded them in the case of a new privately owned railway company. Municipalities, however, for their own new railway construction as well as for new extensions of the railways of private companies, always prescribe that they be constructed and operated in accordance with existing technical standards. The recommendatioias of the German Earth Current Commission are recognized as the existing technical standards in matters relating to electrolysis and in this manner they have assumed almost the importance of law. These regulations are being generally incorporated in contracts for new enterprises or extensions, and in such cases they do substantially attain the force of law. (a) Commission Recommendations. The work of the German Earth Current Commission is described in detail in another place, and a translation of the complete text of its recommendations is given later. The recommendations of the Commission were adopted by the German Electrotechnical Society in 1910. In abstract the recommendations prescribe the following : In large cities, and in general in urban networks and for a distance of 2 km. (1.24 miles) beyond, the overall rail drop is limited to 2.5 volts. Outside of this zone, and in general in small places or for single lines, the potential gradient is limited to 1 volt per km. (1.6 volts per mile). Exceptions are made for roads operating only a few hours in the day. Bonds must not increase the resistance of tracks over 20 per cent; they must be tested yearly, and when a bond shows a resistance higher than ten meters (11 yards) of rail it must be repaired. Connections to pipes are prohibited. Bare return feeders are not allowed. Pilot wires are prescribed. The voltage limits given are interpreted to be the average for the entire daily period of operation, usually 18 to 20 hours in 24 hours. If measurements are not actually taken over the entire period they are corrected to obtain a figure corresponding to this average. 2. Italy. The Government has not enacted any law affecting the operation of electric railways in relation to electrolysis problems, nor has any municipality issued regulations on the subject. 3. France. Regulation in France is based on a Ministerial decree of March 21, 1911, establishing the technical conditions which electrical distribution systems must satisfy in order to conform to the Law of June 15, 1906. A translation of the text of this decree is given later. Briefly the requirements are : That the maximum voltage drop in rail returns of electric tramways shall not exceed one volt per kilometer (1.6 volts per mile) ; an exception is made for locations where metallic masses, such as pipe networks, do not exist. Bonds must be kept in the best possible condition; the resistance of a bond must not be greater than ten meters (11 yards) of normal rail. Return feeders must be insulated. Periodic tests must be made and recorded on a register subject to inspection by the control service. No definition is given of the time element in the measurement of maximum drop, except that it is stated that it must be the average for the normal schedule. 4. Spain. A translation of sections of the Law of March 23, 1900, relating to electric railway return circuits is given later. Briefly, this law requires the overall voltage not to exceed seven volts, specifies bonding and cross-bonding, and where necessary reinforcements of rail conductivity. 5. Great Britain. Control of electrolysis matters in Great Britain is obtained through regulations made by the Board of Trade under the provisions of special Tramways Acts or Light Railway Orders authorizing "lines" on public roads; for regulating the use of electric power; for preventing fusion or injurious electrolytic action of or on gas or water pipes or other metallic pipes, structures, or substances ; and for minimizing, as far as it is reasonably practicable injurious interference with the electric wires, lines, and apparatus of parties other than the railway company, and the current therein, whether such lines do or do not use the earth as a return. The Board of Trade Regulations were first made in March, 1894; they have been revised from time to time, the last revision having been made in September, 1912. The full text of the Regulations is given in a following section of this report. In abstract, the regulations prescribe that the overall rail drop shall not exceed seven volts, and there are also clauses concerning track leakage, the measurement of these quantities, etc. The regulations also provide for circular returns to be made upon the call of the proper authorities. The Board of Trade makes inspections on its own initiative because it is responsible for its rules, which have substantially the force of law; it also investigates complaints. There are no regular inspections on account of the lack of a proper appropriation. Most of its information is obtained from the returns; the latest call for a return was issued in 1906. about twenty minutes at peak load. This "average" is obtained as the mean between the average of the maxima during the period (disregarding unusually high swings) and the actual average of all measurements. This quantity is usually obtained in practice from inspection of recording instrument charts. There are no local ordinances which have the effect of modifying the Board of Trade Regulations. Pipe owning companies cannot recover damages in case corrosion occurs where the Regulations are complied with. This has led to numerous applications to Parliament for special statutory orders fixing responsibility for damage, or special clauses of like import in Acts granting powers to electric railway undertakings. Most of these have been refused, but some have been granted. It is generally admitted that the Board of Trade Regulations, as originally drawn, were empirical, and that they might be remodeled with advantage ; but since the only feature of the regulations actually rigidly enforced, namely, the limit for overall rail drop, results in substantial immunity, the great difficulty attending revision has not seemed to be justified. Railway electrifications, as distinguished from tramways, do not come under the above regulations unless it is especially provided in the Parliamentary Act authorizing the electrification. Recent advices indicate that railway electrifications generally have not been brought under the Regulations. C. CONSTRUCTION CHARACTERISTICS General types of construction for electric railways and pipe or cable systems and special features characterizing such systems in the various countries visited, are summarized here. Details of construction and statistical tables are given in Figs. 25 to 31, and Tables 7 and 8. In large cities the tramways are supplied from a number of substations, as in the municipal systems of Glasgow and Manchester. In Berlin, particularly the railway system is supplied from a great number of combination light and railway substations feeding limited districts entailing relatively small positive line drop of potential. In England, average feeding distances are said to be from two to three miles (3 to 5 km). did not present any features differentiating them from piping systems in America, so far as the electrolysis problem is concerned. In general, pipes are laid in somewhat more shallow trenches than in our northern states, and interconnection between \ Present Standard "Brit Stand." N? 4 Bessemer Steel 100- 105 Ibs per yd Fish plates 2' long 635 Ibsper pair (101-121 Ibs. per yard) for tramways, and 30-40 kg. per meter (60-81 Ibs. per yard) for interurban lines. In France the ordinary rail weights are 46 to 51 kg. per meter (93-103 Ibs. per yard). In England rail weights vary from 70 to 100 Ibs. per yard (34.7- are most commonly used in Germany and France. The Metropolitan System, in Paris, places the bonds under the base flange of the rail. In England, solid copper pin type bonds', protected Thomson-Houston are welded. In England Thermit welds have been used very extensively, giving good results electrically, but having short life due to mechanical weakness where traffic is heavy. A type of electrically welded continuous rail, very extensively used 4. Cross Bonds. In Germany, cross bonds are used about every ten rails, i.e., every 100 meters (109 yards). In France they are placed every 50 to 100 meters (55 to 109 yards) and have the same area as the small rail-bonds. In England cross bonds are generally every forty yards (36.6 meters) and they have the same area as the rail-bonds. (See Fig. 29). the roadbed constructions used did not tend to affect a reduction of leakage from tracks; a similar opinion was held in England. The types of construction referred to were those illustrated in Figs. 30 and 31. LC. Cable A later English report (1920) emphasizes the importance of thorough drainage, as provided by broken stone foundations, as a means for reducing leakage current. The same report gives the following as good average leakage figures for tramway rails in of the leakage for tramway rails. Tests made in Strassburg indicated that leakage currents were fifty per cent greater in summer than in winter when the ground was frozen. In snow storms, however, the winter leakage currents were increased as the cars were using more current. 6. Feeders. Insulated return feeders are used almost universally in Germany. In Berlin and Hamburg these return feeders are of the same number and size as the positive feeders, but generally in other towns the return feeders are of smaller cross-section. Separate feeders are generally used, but not exclusively, as feeders with resistance taps are used in some cases. Formerly there were cases of feeders tapping at several points but important cases have been corrected by the insertion of resistances. No design data for feeder resistances were obtained. The Hamburg installation of insulated feeders was made prior to the formation of the German Earth Current Commission. It gave valuable information in guiding the recommendations of the Commission. Return feeders are not used for tramways in Italy; in large installations bare returns are generally used. In France most tramways have but one feeding point to the rails. Insulated return feeders are used for the conduit tramways in Paris, but little elsewhere. In England insulated return feeders are used wherever they are necessary to bring the rail drop within the B. O. T. regulations; separate feeders are generally used. There is very little overhead feeder line construction in Germany, and almost none in England. In Germany insulated negative feeder systems have been carefully calculated in recent installations. In England they are calculated only in the larger, well supervised systems; elsewhere they are installed by "cut-and-try" methods. The same grade of insulation is usually provided for both positive and negative feeders. The distinction between copper which merely parallels the rails, and feeders which are intended to reduce overall potentials by maintaining equipotential points in the rail network, is clearly understood in Germany and England. Recent reports concerning heavy railway electrifications in England indicate that insulated return feeders are not generally used on such systems, possibly because they are not limited to the overall voltages of the Tramway regulations. The usual practice is to locate the substation close to the track and to connect the negative bus to the rails with short, heavy, cables. In general the negative busbars of substations supplying electrified railw lys are not deliberately earthed, by means of earth plates, connections to piping systems, or otherwise. Two railway electrifications and some of the underground railways in the Metropolitan District provide an insulated fourth rail for return current, leaving the running rails free for signaling. 7. Negative Boosters. Negative boosters are used in many places. In Germany the general practice is not to use them but they are much more extensively used in England (See Table 8) where they are generally found in the larger systems. They are considered more economical than resistances in the return feeders and also better for regulation where the load centers shift. In one large .city their use was discontinued after they had been in operation for some time. The Tramways of Danzig, in Germany, operated by a private company and having a maximum load of 600 kw., has used boosters since 1906. The use of a negative booster in the return circuit of an electrified railway is mentioned in a recent report. The booster was installed for the purpose of relieving load on a section of the line , 8. Double Trolley. The double trolley system is not in general use in any of the countries visited. One or two very special cases near Laboratories in Germany, the district within two or three miles, (three to five kilometers) of the Greenwich Observatory, and some conduit tramways of the London County Council System and in Paris were the only cases noted. The double trolley is also used in connection with a few miles of rail less trolley in England. The three-wire system has been applied to electric railways in a few cases in Germany. In each case the distribution of load between polarities was by districts, that is, certain entire sections have the trolley wire negative. Under these conditions the systems may become considerably unbalanced. In France, the Chem de Per Nord-Sud, in Paris, employs a three-wire system with two motors per car, positive and negative, the running rails acting as a grounded neutral while the supply is provided by a third rail and one trolley wire. The three-wire system has not been applied to tramways in England. The City and South London Underground Railway employed it, but this was to be discontinued following consolidation with other systems. 10. Negative Trolley. The trolley wire was originally made negative in Nuremberg, and in St. Gall, Switzerland. The scheme has been abandoned in both places. This connection has not been used for tramways in Italy, France or England. 11. Pilot Wires. In Germany permanent means for measuring overall potentials are very generally provided, but the methods of doing this vary widely. Pilot wires are usually provided for new installations in France. In England pilot wires are universally used in connection with recording instruments. The practice varies widely, but the most common method employs No. 14 or No. 16 gauge wires laid with the main cables, and extended beyond them. 12. Bond Testing. Bond testing is generally done in Germany on some systematic basis, more often annually, but in some large systems semiannually. The bond-testing devices are generally of the three contact type with differential galvanometer. Some of these are said to be undesirable on account of the form of the contact, others because the rail points span too short a length, or on account of the type of galvanometer employed, etc. In England it is stated that there is practically no systematic bond testing, except in the large well supervised systems. 13. Pipes and Pipe Joints. Cast-iron pipes in England and Germany are generally of the bell and spigot type with lead calked joints. In Germany flanged joints are frequently used for special fittings, valves, tees and hydrant taps for water mains. Cast-iron pipes are little used in France; pipe joints are either lead calked bell and spigot, or in large pipes flanged, with rubber gaskets. Insulating joints are not used, except that in England it is said that they are occasionally used for water pipes in special cases. 14. Depth of Pipes Below Surface. In Germany, 'gas pipes are generally laid 0.8 to 1 meter (2.6 to 3.3 feet) and water pipes 1 to 1.5 meters (3.3 to 5 ft.) below the surface. In France, gas pipes are laid where possible 0.6 meter (2.0 feet) below the surface, L. T. cables 0.7 meter (2.3 feet) and H. T. cables 1.3 meters (4.3 feet). In England 1 foot (0.3 meter) is said to be dangerous, 2 feet (0.6 meter) was given as an average by one authority, and 2.5 to 5 feet (0.8 to 1.5 meters) by another. In all cases the above depths are only typical, the practice varies widely. 15. Mains on Both Sides of Streets. In Germany, France, and England mains are laid on both sides of the principal streets; in Paris, for streets wider than 14 meters (46 feet); also in streets with wood or asphalt pavements, and generally in the larger towns. In narrow streets or unimportant places one main is used. In Paris the pipes for water are located in the sewers, not in direct contact with soil, and remote from trouble. 16. Insulating Coverings for Pipes. In Germany it is held that insulating coverings do not afford protection against electrolysis, as their effect is merely to concentrate escaping stray currents since perfect coverings cannot be maintained. They should only be used where it is desired to protect against chemical corrosion from the soil. In France, gas engineers stated that insulating coverings were being studied, but it was not believed that they would prove practicable. In England insulating coverings are not considered good protection against stray railway currents. High pressure gas pipes have been covered with pitch canvas, and the London Water Board pipes are provided with an asphalt dip coating but more as a protection against chemical corrosion. 17. Electric Cables. Cables are more frequently laid solid in the ground, and conduits are used less than in America. Metal conduits are only occasionally used in England; where they are used the cable sheaths are bonded to the conduits. Insulating joints are not used in Germany or England for telephone cables. Among the countries visited it was found that in Germany engineers and managers of the utilities concerned were fully alive to the problem of stray current electrolysis, and they were well informed, due largely to the work of their Earth Current Commission. In England, although engineers and managers were generally informed, there was little lively interest in the question, due probably to the fact that there does not exist any acute electrolysis problem. In France, the Government and the Paris municipality had recently (1914) appointed a Commission to investigate the subject of stray current electrolysis and make recommendations regarding the situation in the City of Paris. In Italy, troubles from electrolysis have been considered insignificant. Some of the larger systems in important cities are alive to the situation and are following with interest the developments in other countries. Favorable reports of immunity from electrolysis troubles were based, as in Italy, on the absence of complaints. It was noteworthy that reports of damage were greatest where most thorough investigation had been made. (a) Germany. Considerable damage was found in many cities prior to the application of the Earth Current Regulations ; in one case service pipe trouble occurred as often as once a month. Generally however, extensive damage was not known until it was revealed by investigation. Thus, many of the cities which were surveyed by the Commission, and where more or less corrosion was found, had previously reported no damage. In the past the majority of troubles have been on gas and water pipes, or at least these have received more attention in the reports. No cases of extensive damage to cable sheaths were found. Many very thorough tests have been made in Germany and a large majority of these have shown that corrosion was being produced by stray railway currents. In general, the pipe owning interests stated that the situation was such that the work of the Earth Current Commission was urgently needed. Gas and water experts expressed the opinion that the regulations were too lenient, while the railway experts felt that they were too severe, maintaining that a considerable amount of corrosion ascribed to stray railway current, was in fact, due to other sources, or to selfcorrosion. In general, present conditions in Germany were considered satisfactory where the electric railways have conformed to the Commission Regulations ; or where conditions were already equally good. In other cases the conditions were considered to be unsatisfactory. The more prosperous companies and municipalities spent money for improvements after the publication of the Regulations of the Earth Current Commission. Exact information was not available regarding the number of places where changes had been made, but the best information indicated that the number was between 20 and 30. Of these, Danzig, Strasburg and Erfurt expended about 100,000 Marks each, rearranging the resistances of exivSting return conductors, and Dresden was engaged in 1914 in insulating the existing bare return conductors. Generally, the most important cities were rapidly improving their return circuit conditions. Also, other undertakings not subject to the Regulations were changing over voluntarily for reasons of policy or economy, or as the result of compromise to avoid litigation; this was said to be the case in 30 or 40 important towns. A litigated case, in Mansfeld, was decided against the gas company on legal grounds as the railway existed before the gas plant. Where return circuits have not been remodeled in accordance with the Commission Regulations, overall voltage limits vary greatly, but in the majority of cases they are between 5 and 10 volts overall. Measurements were made by the Sub-Committee of one large installation having negative feeders equal in number and area to the positive feeders; it was found that the maximum drops in rails were well within the limits prescribed by the Regulations. (b) Italy. From a survey made about 1908 in a city of Italy, it was found that the maximum difference of potential in the rails between the station and points about three miles (5 kilometers) distant were as great as 17.5 volts. In this installation they had not received complaints of serious damage by electrolysis, except a few gas service pipes, although the railroad itself had experienced some difficulties on water pipes at* one of its yards. (c) France. The Sub-Committee's investigation was somewhat limited in France. No adequate or complete tests have been made, although some testing has been done in Paris following the development of trouble. It is stated that tramways in France generally endeavor to' observe the 1 volt per km. limit (1.6 volts per mile), and that potential differences between pipes and rails rarely exceed one volt. In general serious electrolysis troubles were found only in a few places, either created by heavy traffic lines or by peculiar conditions, not readily explainable. Outside of Paris there is little damage caused by tramway systems. In the suburbs of Paris all underground pipe systems are more or less affected. In Paris 60 to 70 cases of damage to pipes have been found in a year — the actual cost of repairs was estimated to be 60,000 francs, but it was held that the paramount consideration was the danger to security of service, since nearly all cases caused property losses in buildings, although- there were no explosions. wire systems of electric light distribution, but these troubles were of a temporary character and were promptly remedied as soon as discovered. In the other cases, due to stray railway currents, the troubles were persistent. About twenty litigated cases for electrolysis damage were pending in Paris in 1914. A very considerable amount of damage in Paris is due to the "Metropolitan" subway system which claims exemption from the 1 volt per km. (1.6 volts per mile) regulation, not being a tramway. At one place in Paris a potential difference of 6 volts between a railway structure and a pipe was observed by the SubCommittee. (d) Great Britain. Considerable damage is said to have occurred in the early days of electric traction in England, although such damage was apparently insignificant compared to conditions familiar in America during the same period. Practically no damage has occurred in recent years, and certainly no extensive damage. Two or three cases, local in character and of small extent, have occurred in localities where the Board of Trade Regulations were complied with. In England there is very little good evidence in the way of tests, and the general statements of Immunity are based on absence of trouble. The Post Office, and the South Metropolitan Gas Company of London, both make systematic tests and find no trouble except that the Post Office has, from time to time, encountered difficulties quite local in character, due to stray currents. .The Board of Trade Regulations are not considered onerous by any of the railway engineers consulted. All authorities representing the pipe owning companies, the tramways, the state telegraph and telephone, and the Board of Trade, were unanimous in stating that the electrolysis situation for the properties under their respective control was entirely satisfactory. Nevertheless, there is considerable feeling -among the privately owned gas companies that they are not adequately protected, since, as noted elsewhere, they cannot recover damages in case corrosion occurs where Regulations are complied with. Overall rail drops for tramways in England are generally very much lower than the Board of Trade requirement, averaging probably 2.5 to 3 volts, with the exception of occasional drops, which may be as high as 15 or 20 volts, due to extraordinary traffic at football matches, etc. The average overall drops for several large cities visited by the Sub-Committee during June and July, 1914, were about 2 volts. Glasgow, which voluntarily adopted a 2 volt rail drop, Manchester, and other large towns, have extraordinarily low rail drops. The electrification of branch railway lines has been carried out to a considerable extent since 1914, and some data were obtained in 1920 concerning the voltage drop in the return circuits of such lines. Two electrified sections of an extensive railway system are reported to have maximum instantaneous voltage drops as follows : B 77 volts Another railway reports in general that the voltage drop for its electrified sections is higher than that permitted for tramways; and in particular that the worst section gives a maximum drop of 25 volts for 15 to 20 seconds, with instantaneous maxima considerably higher. 1. Drainage System. Electrical drainage as a palliative measure for electrolysis was formerly applied in one or two cases in Germany, notably in Aachen, but it was abandoned on account of damage produced by it, first due to joint corrosion, and second, damage to other underground structures. It is condemned by the engineers of the Earth Current Commission. In England, drainage is not approved as a general measure to afford relief from stray current, although there are a few specia instances of its application to the tramway company's own lead covered cables, where the common practice is to bond to the rails at many points. In Germany the possibility of chemical corrosion (that is, corrosion without an external supply of electricity) is recognized, and distinction is made between such corrosion and that produced by stray currents. Pipe corrosion has actually been found under conditions where it could not have been produced by stray currents. No definite information was obtained in England regarding the corrosive properties of soil, but it was stated that chemical corrosion was known to occur. Such corrosion does not, however, produce acute conditions as in electrolysis; it is rviore like ordinary oxidation. German reports gave the resistance of soil as varying from 1 ohm to 2,000 ohms per cubic meter (1.3 ohms to 2,616 ohms per cubic yard), averaging about 100 ohms per cubic meter, (131 ohms per cubic yard) . In England no specific information was obtained concerning earth resistance. One report states that the provisions of clause 5A of Tramway Regulations (for two earth plates not less than 20 yards, (18 meters) apart between which an E.M.F. not more than 4 volts shall produce current of 2 amperes) cannot be met even at permanent water level, and that in general the apparent resistance is about twice that required by Regulations. 3. Electrolysis Testing Methods. In England very little testing is done to investigate electrolysis questions and no technique has been developed for such work. The only extensive work in recent years is that of the Cunliffe brothers, and their work was directed mainly toward the investigation of certain theoretical questions rather than toward the systematic investigation of actual experience with stray currents. In .Germany the work of the Earth Current Commission has been already noted. The surveys made by the engineers of the Commission are systematically planned; they are made in the most excellent technical manner. The reports are quite uniform in character; they start with a general investigation of geological conditions, the character of the soil, ground water, etc., continuing with a general survey of the present condition of the railway property, including distribution of load, track and rail resistance, location and loading of supply and return circuit cables and any other electrical data relating to the investigation. The surveys then take up the specific measurements relating to stray current, such as potential differences between pipes and rails, current in pipes, and so forth. Reasoning from the data presented, recommendations are made for improving conditions, where improvements are needed, sometimes with estimates for the cost of the work. In some cases a supplementary report is made which shows the conditions after the changes have been made. The conclusions arrived at appeared to be practicable and reasonably acceptable to all parties concerned. 4. Economic Aspects of the Electrolysis Problem. About forty per cent of the electric railway systems in Germany, and about seventy per cent in Great Britain, are municipally owned. In Germany one authority thought that municipalities were more ready than private companies to spend money for the purpose of improving their return circuits, but in England it was thought that there was no difference in this respect. It was said in Germany that where municipalities owned the water, gas, and tramway systems, they may prefer to assume the cost of damage rather than make large expenditure for protecting their pipes. Also in Germany, a study of the survey reports of the Earth Current Commission indicated that in no case was the yearly cost of repairs for damage by electrolysis of such amount that, on the surface, large expenditures for improvements would be justified. The Commission, however, while recognizing the importance of the financial aspect of the problem, still recommended the adoption of the relatively expensive remedies for the reason they state — "that the repairs will certainly become more frequent with lapse of time, and besides the increased expense so caused, there is the liability of service interruption, disturbance of traffic, pavement replacement and even danger of explosion to be considered." Opinions differed in Germany as to whether or not the prevailing regulations constituted a financial hardship. In England, the Board of Trade Regulations are nowhere considered a hardship, and where inquiry was made as to whether the existing regulations had retarded the development of electric railways, the authorities consulted uniformly stated that this was not the case. It appears that in fact a saturation point has been reached, and busses are being used where tramways would not pay. Traffic conditions are said to be quite as heavy in England as in the United States. Only one authority in England ventured an estimate of the average load factor for English electric railways systems; he estimated it to be thirty-five per cent. 5. Application to American Conditions. Disputes on account of electrolysis troubles have been prevalent in the past in all countries having any considerable electric railway development, before systematic cooperative studies or regulations were applied; this in spite of the fact that the mode of life and distribution of population and industries are more favorable than in American cities. The average weight of cars in foreign cities is less than in America, and the tramway traffic and power re- for cities of the same population. A city like Berlin with over 2,000,000 inhabitants handled all of its transportation with a maximum load of about 30,000 kw. (Chicago with over 2,200,000 population required a maximum load of about 200,000 kw.) Manchester with a population of 1,250,000 and Glasgow with 1,000,000 had traction loads of 11,000 kw. and 11,500 kw. respectively. (Boston and the territory served by its traction system with about 1,150,000 people, required station capacity of 75,000 kw.) Milan with a population of over 600,000 had a traction load of approximately 8,000 kw., and Nurnberg with 350,000 inhabitants used only 1,000 kw. (The city of Worcester, Mass., with a population of approximately 160,000 required power station capacity of 7500 kw.). These comparisons should be taken into consideration in applying to this country the results of this investigation of foreign practice. These comparisons, however, should not be taken as a definite index to comparative electrolysis conditions, since many other factors are involved. Regardless of the degree of improvement which economical limitations may make permissible to accomplish in local situations, the fundamentals for the solution of the electrolysis problem evolved abroad merit the most careful study to ascertain their possible application to American conditions. as follows : Germany, through voluntary cooperation, has probably remedied the former dangerous electrolysis conditions for all of its important systems. The instrumentality of agreements on definite technical standards was sought in preference to legislation. tion wherever possible, of pipes and rails. 3. Avoidance of bare copper returns and use of insulated returns in all installations where the conductivity of the rail alone would give a too great maximum drop. 4. Use of insulated return feeders with balancing resistances, or to a lesser extent ''boosters" for the purpose of maintaining equality of rail potential at the feeding points of all reeders. ADOPTED BY THE GAS, WATER, AND RAILWAY INTERESTS OF GERMANY. Regulations for the protection of gas and water mains from the electrolytic action of currents from direct current electric railways which use the rails as a return. Section 1. Application of Rules. The following rules govern the installation of direct current railways or sections of direct current railways which use the rails for carrying the return current. Unless otherwise mentioned the herein given admissible potential values should be adhered to when laying out new railways. For determining the resistance of a line, the rails only must be taken into account as current carrying mediums and the assumed resistance of the rails, as well as the assumed percentage increase of resistance due to the bonding must be stated. operation. These rules do not apply when railways are laid with special track or when the rails are laid on wooden sleepers, in which case there is generally an air clearance between the rails and the stone ballast; but the rules do apply if this air clearance does not exist, as at grade crossings, unless an equivalent insulation is provided The regulations apply only to direct current railroads or sections of such, using the rails as conductors. Railroads not using the rails as conductors are eliminated from the start, because the same do not send any currents into the earth and therefore cannot have any damaging influence on the pipes. According to the experience reached so far, alternating current seems to have very little effect, so that any extension of these rules to cover also alternating current railways does not seem justified. At any rate, the conditions produced by alternating current railways are not yet sufficiently understood to allow of establishing any restrictions in regard to their equipment and operation for the protection of pipes. In case a railroad is operated partly with direct current and partly with alternating current, these regulations apply only to those sections, the rails of which carry direct current. The fixed upper limits of permissible potentials apply to the design of the plant, unless otherwise stated, and in the calculations only the rails and the bonds are to be considered as far as the conductivity and the resistances of the conductors are concerned. The assumed resistance of the rails and the increase of same by the resistance of the bonds is to be stated, and such limiting values are not to be exceeded either by calculations or in practice. The earth as a shunt is not considered. Through contact of the rail network with the ground, a part of the current passes into the ground and the potentials of the rail network are thereby lowered as compared with a case of perfect insulation from the ground, the effect becoming greater, the more the current passes into the ground. It is, therefore, not correct to take the differences of potentials ' as found immediately after the construction of a rail network as a basis for estimating the safety against damaging influences, but it is necessary to go back to the first cause, that is to say, the differences of potential as they would be if the rails were completely insulated. the design of the plant without any uncertain and varying values for different localities. The limit values are not to be exceeded either during the calculations or at the actual practical test. The method of the practical test will be discussed in Section 3. The projection of the plant is, therefore, to be based on assumptions as correct as possible with regard to the resistance of the rail, the cables, and the consumption of current, and it is advisable to consider also a later increase of the traffic. Railroads, the rails of which are insulated on special roadbeds, generally have such a great resistance against the earth that passage of current into the ground of such magnitude as to be considered dangerous to pipes does not occur. Higher potentials, therefore, are permissible for such railroads, assuming that a sufficient insulation is provided for also on grade crossing, etc. As a means to this end are to be considered : Insulating strata between rails and ground, for instance, tar paper, which must extend on. all sides sufficiently beyond the place in question; or the surrounding of the pipes with insulating material. Such places are to be inspected from time to time to ascertain the effect of such insulation. For the exemption from these regulations the laying of the rails on a special roadbed is required, because it is only in this way that a permanent insulation can be reached and maintained. About the details of the system of insulation to be used, no rules were issued. A lasting insulation is to be guaranteed by the way in which the rails are laid. The laying of rails on wooden ties as mentioned above is intended as an example only. At any rate to secure satisfactory insulation it is imperative that the rails be nowhere in contact with the moisture of the ground, as this greatly favors the passage of the current into the ground. Tracks which are at all points at least 200 m. distant from any pipes are exempt, because any current coming over such an extended area spreads to such a degree that its density cannot possibly be harmful. In this respect concession has been made to long outlying railway lines because the subjection of such to these regulations would entail great economic disadvantages in certain cases. The maintenance of good conductivity on such outlying sections is to be strongly recommended so as to prevent the return currents from reaching a dangerous density where such sections join the rails of an inner rail network, i.e., a density exceeding the limit given in Section 5. Section 2. Rail Conductors All rails serving as return conductors should be built with regard to this requirement, should be made as good conductors as possible, and should always be kept in good order. The percentage of increase of the resistance of a given length of track due to the bonding should not exceed the value assumed when laying out the railway, and must not be more than 20% more than the resistance of the same length of track if the rails were without joints and of the same cross-section and the same specific conductivity. On laying out a railway line consisting of main and auxiliary rails, the combined cross-section of both rails can only be taken into account when determining the resistance of the track, provided the auxiliary as well as the main rails are properly bonded and cross bonded. by special bridge bonds. On single tracks as well as on lines where several tracks are lying side by side the rails must be efficiently cross bonded and these cross- and bridge-bonds must have a conductivity at least equal to a copper conductor of 80 square millimeters. At all movable bridges or similar structures which necessitate an interruption of the rails, special insulated conductors have to be provided which secure a continuous connection between the two rail ends. In such cases, the voltage drop at average load must not exceed 5 millivolts for each meter distance between the interrupted rails. All current carrying conductors which are connected to the rails, must be insulated from earth, excepting short connections such as bonds, cross-bonds and bridge-bonds at switches and turntables. If such bonds are laid not deeper than 25 centimeters into the earth, they may be bare conductors. Explanation The first condition for the reduction of stray currents and for the effectiveness of all the proposed precautionary measures, is the good conductivity of the tracks and the maintenance of this conductivity. High resistances of the single sections cause an increase of the current passing into the ground. The maintenance of the good conductivity of the rails also is to the economic interest of the railroad, because a bad conductivity will, under certain circumstances, cause loss of energy. of rails or for the conductivity of the steel because the cross-section and the chemical composition of the steel are both determined by mechanical considerations; the conductivity is dependent on the composition of the steel, while the conductance of the rail depends on both the conductivity and the profile. quality of the electrical connections of the rails at their joints. The rules do not recommend one or another system of connections at the joints, but give data covering the permissible increase of the resistance by such connections. In consideration of the varying resistance of rails of different profile, it is not possible to establish a uniform permissible resistance for a bond but the permissible increase of the total resistance of a section by all the bonds is given. This increase must not be over 20 per cent. Inside of these limits the designing engineer may assume any increase of the resistance by the bond, but it must be considered that the increase assumed must be permanently maintained later on (compare Sections 6 and 3) . It will be well to assume during the design of the plant, the increase of resistance of the bonds as very near the permissible limit. This is very important when shorter rails are to be used, with the consequent greater number of joints, the maintenance of which is correspondingly more difficult and, therefore, an increase of resistance through deficient bonds to be expected. The conductivity of rails is to be ascertained on a number of samples before the rails are laid, so as to have a guarantee that the calculated resistance will correspond to the resistance of the finished work. The measurement of the resistance is made, by measuring the current and the potential on a raitas long as possible and insulated from its supports ; the potential terminals should include a part of the circuit between the current contacts and they should be at least 0.5 meter distant from these current contacts. A simple calculation gives the conductivity of the rail by using the value shown by ammeter and voltmeter. The conductivity of the rails now in use is generally found to be between 4 and 5.5 Siemens (10.5 to 14.4 times the resistivity of copper). In cases where main and auxiliary rails are to be used and where the combined cross-section of both is taken into calculation, the conductivity of the auxiliary rail also is to be measured as the same may differ considerably from the conductivity of the main rail. will take place caused by the vibrations brought about by the passage of the rolling stock, for which reason such places are to be bridged specially by electrical conductors. The cross connections serve the purpose of eliminating differences of potentials between tracks running side by side and also to insure a good metallic connection between the rails on one side of a track in the case of a temporary low conductivity of single joints or interruptions. It seems advisable in consideration of the different length of rails, not to give an absolute distance between the cross connections, but to establish their number by the number of joints. The bonds and cross-connections may be of any material as long as their conductivity reaches at least that of a copper connector of 80 square mm. For the connection of interrupted tracks, as for instance at movable bridges, insulated cables are required because of the presence of water or other substances in the soil, which highly favor the passage of currents into the ground. The highest permissible drop in potential at average load has been fixed at 5 millivolts per meter distance between the places of interruption, to insure a small difference of potential between these points. Furthermore care is to be taken that the tracks in a movable bridge are in good contact with the tracks on both sides of it. The following is an example of the calculation of a cable bridging across the gap. When the distance between the tracks at the point of interruption equals 30 meters, the permissible difference of potential, therefore, is 5 x 30 which equals 150 millivolts. The current to be carried across is assumed to be 120 amperes and the length of cable 30 meters. Assuming a specific resistance of 17.5 milliohms per meter and square millimeter, the resulting cross-section is: Inasmuch as the increase of the surface contact between the conductors and ground results in an increase of the current passing from the conductors into the ground, the conductors connected to the rails, especially those lying deep enough to come into contact with the moisture of the ground, are to be insulated conductors. Only short connections, such as jumpers on crossings and switches, are exempt from this rule on account of the same not lying deeper than 25 cm. under the surface, which means that they hardly come into contact with the moisture of the ground. The increase of surface of the contacts with the ground by these conductors is too small in proportion to the total surface of the rail network to cause any apprehension regarding the currents passing into the ground. network. In the urban network and for a distance of 2 km. beyond, the voltage drop between any two rail points should never exceed 2.5 volts when the line is working under normal conditions, and the drop in the rails for each kilometer of open road should not exceed 1 volt. Occasional night cars are not to be considered in determining the average load. In townships through which only a single line is run, without local rail network, the total voltage drop in the rails must not exceed 2.5 volts from end to end of the township's pipe network. drop above the stated limits. If various railway systems are connected together either through the medium of the rails or through the power station, each system must fulfill the above conditions. A rail system in a township with an independent pipe network has to comply with the above regulations also. Exceptions from these rules in regard to the voltage drop in a railway network are admissible if local conditions and service necessitate and justify such exceptions. If, for instance, the service — as is the .case in freight yards — covers only a small portion of the day, the above limits of rail drops may be exceeded. In yards with a service up to three hours daily, double the above values are permitted, and with a service up to one hour, four times the above values are allowed. For the calculation of the potentials the value of the average current is to be used, as the magnitude of electrolytic decomposition of the pipe metal depends on the quantity of current, that is to say, the product of current and time. The highest values have not to be considered for the calculations. To find the consumption of current the average service as per schedule has to serve as the base. The average current consumed on single sections can be calculated from the number of car km. or ton km. to be covered, by using the value for the consumption of current which, according to experience, and in consideration of the local conditions, is used for one car km. or ton km. But it is also permissible to distribute the consumption of current over the whole net in a way corresponding to the locations of the single trains at the time of the average load and to calculate for each train the consumption of current taking into consideration the weight of the cars, the speed and operating conditions (grade, stops). In regard to the schedule, the difference between summer and winter service is to be considered. The increase at regular intervals, as for instance on Sundays, is to be taken into account. Small deviations from the schedule, as for instance, single night cars, or auxiliary cars, shall not be considered, because the first would reduce the average value out of proportion, and the frequency of the second cannot be estimated at the time of the calculations and otherwise are not of any appreciable influence on the final results. It is impossible to get regulations embracing all conditions and possibilities land it is therefore necessary to consider all peculiarities of a plant during its projection.. If there are any additional places connected to the rails, where current is used for stationary motors, station lighting, etc., these are to be considered. After the drops in potential on the central sections have been tabulated, based on the above calculations, the distribution of the potential in the rail network can be found. In addition to the foregoing data for the calculation of the drop in potential on the single sections, consideration is to be given to the proposed return cables and, in case of a three wire system, to the direction of the current in the districts of different polarity. in metallic contact with any other network) and also around single pipes, a zone of 200 m. is to be circumscribed and all tracks lying outside of this zone are not be to considered in connection with these regulations, as per last part of Section 1 . pipe networks, the following rules apply : If there are any branches of the railroad inside of a pipe network, including the 200 m. zones, a belt 2 km. wide is to be laid around the inner rail network. Inside this belt the potential of the rails between any different points must nowhere exceed 2.5 v., as long as no portion of the rails is more than 200 m. distant from the nearest pipe along its total length. (Compare Fig. 32). On the sections outside the 2.5 v. districts, the drop in potential must not exceed 1 v. per km. This applies to outlying sections which are shown in Fig. 32 by heavy dotted lines. In the case of a railroad with no branches (country roads) and a pipe network, the drop in potential inside the pipe network must not exceed 2.5 v. (Compare Fig. 33). The rule establishing a drop of 1 v. per km. states that the current in the track must not exceed === if W is the resistance of the track in ohms per km. For a uniform load of a section of L km. length and a uniform resistance, the permissible drop in potential is -^ v. i.e. one-half the drop in average load, according to the shedule. Strict rules have been issued for the interior rail network with its many branches, as it mostly covers the same area as the pipe network. This has been done in consideration of the greater surface of contact between ground and rails and pipes, respectively, which increases the probability of a passage of current through the ground. The potential of 2.5 volts for this district has been judged permissible because, according to the results of previous investigations, it is to be assumed that this potential will not under ordinary conditions cause any danger to pipe lines beyond practical limits. To avoid as much as possible any greater concentrations of ground and pipe currents at the outlying sections which immediately join the inner rail network, and where important parts of the pipe network often extend, strict rules have been issued covering the district inside the 2 km. belt around the inner rail network. contemplated by limiting the drop in potential to 1 v. per km. Railroads interconnected by their rail networks or by a common power plant are to be considered as one system because such rail- District of interior pipe • network. District of 200 m. around pipes with no branches. Railroads in the 25 V. District. Railroads in the I V-Km District. Railroads w«th no Restrictions. Fig. 32. District of the pipe -network with the 200m: belt surrounding it and the pipes with no branches.; District of the interior Rail-network with Jjle£Kni., belt surrounding it conditions of the ground, that is to say, in very dry dirt an increase of the potentials may be permissible. But even in such cases it is advisable to be cautious in allowing such an increase, so as not to violate the rules as given in paragraph 5. Where the conditions are unfavorable, for instance, where moist ground of especially high conductivity prevails, it is advisable, to remain below the limits. For railroads with brief daily operation concessions have been made because damage to the pipes depends upon the duration of the influence of the current so that, considering the short time of operation, even greater currents cannot cause any appreciable damage to the pipes. For railroads of three hours daily operation double drop in potential is allowed, while for railroads of one hour operation, four times the drop is permissible. Wherever the rail network is not sufficient to carry the current without exceeding the permissible potential in the network, the whole plan for the return of the current must be altered, and improvement will be reached by providing return cables in which, if necessary, resistances or boosters may be inserted. The resistances should be variable so as to correspond with the variable conditions of service and operation. In cases where the railroad system is fed from several power plants a reduction of the drop in potential in the rails may be brought about by shifting the loads of the several power plants. The arrangement of the cables and resistances can be made in so many different ways as to make a general rule for all cases impossible. It is recommended to investigate thoroughly the cases under observation, because considerable saving in the construction and operation of the plant may be achieved by a careful layout. The keeping of the return points at the same potential is recommended as a precautionary measure but not required. The same offers a certain guarantee of the possibility of keeping the difference of potential within the 2.5 v. limits. Furthermore, the use of the three- wire system with the rails as a neutral conductor is worthy of consideration. In this system the difference of potential in the rails depends on the distribution of the positive and negative feeder districts. This distribution again depends on the local conditions of the plant, so that no general rules can be given in regard to it. Alterations of the conditions of operation can be counteracted by switching the load to the positive or negative side of the system. The rules do not recommend any certain system, but leave it entirely to the projecting engineer to select the one best adapted to existing conditions. The damage to pipes takes place mostly at points of low potential on two-wire railroads, in the neighborhood of the return points ; and on three- wire railroads, in the districts of negative feeders; because it is mainly here that the current leaves the pipes. It is advisable to place the return points of the negative feeder districts whenever possible in locations with dry ground of low conductivity and as far as possible from such pipe lines as are of importance for. the water and gas supply. The permissible limits of differences in potential in rails must not exceed, either according to calculations or at the practical trial, the limits given in Section 1, of these rules. The measurement of the difference in potential is made by means of test wires as called for in Section 6. The measurements of differences in potential are limited to those points which, according to calculations, come nearest to the established limits. Wherever long lines, as, for instance, telephone wires, are available, it is advisable to use them for these measurements otherwise several test wires may be connected in series or temporary test lines may be installed. Finally, the restilts of single measurements may be computed to reach the same final results. Only high resistance voltmeters should be used for these measurements so as to make the resistances of the test wire and .contacts negligible. The pointers of these instruments should have the slowest movements and a good damper arrangement, so as to give good readings even under strong fluctuations. For all measurements only average values are considered. All measurements are to be extended over a full period of operation which results from the average frequency of trains. Section 4. Resistance Between Rail and Earth The resistance between ground and the rail which is used for carrying the return current should be kept as high as possible. When the conditions of the ground or the situation of the track are not favorable for this purpose, the resistance should be increased by a special effective insulation. The rails or any conductor connected to the rails must not be in contact with the pipes or any kind of metal buried in the ground. Furthermore, care must be taken that the distance between the nearest rail and any metallic part of the pipe lines or connections to them which project above the ground or lie be less than one meter. Stationary motors, lighting installations or any other plant which receives current from a railway system which uses the rails for carrying the return current, must be connected to the rail network by means of insulated conductors. Excepted are short connections of not more than 16 square millimeters which are not deeper than 25 centimeters in the ground and which are at a distance of at least 1 meter from any part of a pipe network. These connections may be of bare metal. In order to increase the resistance between rail and ground it is recommended to use a bedding of high resistance and to provide good drainage, also to render the bedding water-tight to the roadbed for a sufficient width on both sides of the rail. to cases of absolute necessity. Wherever sufficient distance between the rail and such parts of the pipe line as project above the surface is not obtainable, it is advisable to change the pipe run, or where this is not possible, to use insulating strata (such as vitrified clay, masonry or wooden conduits, etc. The magnitude of currents passing into the ground depends not only on the potentials in the rail network, but also on the resistances between the rails and the pipes and on the resistances of the pipe lines themselves. It will always be of advantage to increase the resistance of the ground between the rails and the pipes. An artificial increase of the resistances of the pipe line can 'be achieved for instance, by the use of insulating flanges, couplings, etc. Aside from the technical difficulties of installing such insulating parts into gas pipes, and especially water pipes with a high pressure, and of insuring their lasting tightness, it would be difficult to provide these insulating pieces in the necessary numbers and to take care of their correct distribution. A wrong arrangement of the same will lead to an extraordinary concentration of currents at these insulations with consequent corrosion in these places. A greater part of the drop in potential between pipe and rail originally takes place in the roadbed as can be easily understood and it is therefore required to render this resistance as high as possible by the good insulation of the roadbed, good drainage, etc., and to maintain it thus. In the same measure that the increase of the resistances between rail and pipe is recommended, the use of any means to reduce these resistances, is to be warned against. Such means to be considered are ground plates, connections of metals in the ground, and especially metallic connections between the rails and the pipes. The last will reduce the density of the current at the point of connection to the pipe, but they cause an increase of the pipe current and of the ground currents in general which may cause damage in other places, as, for instance, at interruptions in the pipe line or at crossings with other lines. Any local measure taken must be considered with regard to its effect on the pipes in other localities. Metallic connections between different pipe networks also are to be judged from this viewpoint. Immediate contact of any parts of the pipe lines with the rails, or too close an approach, has the same effect as direct metallic connections and is, therefore, to be avoided. (By a relocation of rails or pipes or installation of insulating strata). Especially in cases of stationary motors or lighting plants connected to the railroad system, there exists on the premises danger of an accidental or deliberate connection or contact with the pipe lines. It is, therefore, necessary to have strict rules regarding the return cables from such plants. Section 5. Current Density The above rules are intended to prevent the destruction of the pipes by electrolysis. The rate of destruction is in direct proportion to the amount of current leaving the pipe. Any pipe line where the current leaving the pipe exceeds an average density of 0.75 milliampere per square decimeter and where this current is due to a railway, may be considered endangered by this railway, and further preventive measures must be taken. permissible. In cases where the current leaving or passing into the pipes changes its direction, the current passing into the pipe must be taken as nil when determining the average density, until further experience has been gained in this matter. which would far exceed the cost of any possible damage to the pipes, it is necessary to allow a certain limited damage, that is to say, a damage which is of little practical importance and which does not noticeably shorten the life of the pipes. These rules have therefore been compiled on the basis of the average conditions, that is to say, such as are mostly met with, and it is to be expected according to previous experience that the damage done to pipe lines by the stray currents from electrical railways generally will remain limited to the practical allowable limit wherever these rules are observed. Under exceptionally bad conditions, that is to say, under conditions which very much favor the origin of stray currents, greater corrosion of pipes in certain places can hardly be avoided, even if the limits of the drop in the potential in the rails, as laid down in Section 3, are not exceeded. It is, therefore advisable to establish some measure for the elimination of immediate danger to the pipes. railroad system is indicative. The density of the current at the pipe can be measured only after the completion of the plant. These measurements must be made during the time of operation,. as per schedule, and as described in Section 3. The average density is important and is obtained from the computation of the results of several measurements, each of which follows a whole period of service. Measurements of current density can be made, for instance, by means of a milliammeter and non-polarizable frame as designed by Prof. Haber. This frame contains two copper plates which are insulated from each other and which for the prevention of polarization are covered with a paste of copper sulphate and 20 per cent sulphuric acid, over which a parchment, soaked with sodium sulphate is laid. The frame is filled with dirt except between the plates, and placed alongside the pipe at right angles to the assumed direction of the current and then covered with dirt. A very sensitive ammeter connected to the copper plates will indicate the current passing through the frame and the density of this current can readily be calculated by taking into account the surface of the copper plates inside the frame. Inasmuch as here also only average readings are to be considered, it is advisable to use an instrument with very slow period. pipes reaches the average value of 0.75 milliampere per square decimeter. For railroads with small periods of operation an excess up to double and quadruple, respectively, the above value is permissible according to the rules laid down in Section 3. Wherever the direction of the current changes, the current entering the pipes are not to be considered in the calculations of the average density, inasmuch as it is not yet established that such currents will add to the metal of the pipes. Wherever the average values are exceeded, special precautionary measures are to be taken, the nature of which can be determined only by the local conditions. In many cases it is sufficient to protect a very limited section of the rail network, to which end the further reduction of the drop in the rails may not be necessary, but which may be attained by other means as, for instance, the re-location of short sections of tracks or pipes, or the artificial increase of the' resistances between rails and pipes at such points. In all cases the question arises whether the railroad is to be considered as the only cause of current concentration, as other causes may be found to be responsible for a part of the current on the pipes; for instance, bare neutrals or poor insulation in other electrical systems, the natural electrical elements resulting from the use of different metals in the pipe lines, or from different chemicals in solution in the ground. That part of the current which is attributable to the influence of the railroad can be determined by comparison with the measurements of the current during the period of no operation. In many cases the influence of the railroad can be judged from contemporaneous measurements of current density and the potential between pipe and rail. Under certain circumstances it is possible to find the degree of influence of the railroad and of other electrical plants operating at the same time, by establishing the course of the current in the ground. For this investigation electrodes that cannot be polarized are used as contacts from the test line to the ground. The measurements should preferably be made by the potentiometer method in order to eliminate drop at the electrodes due to the current flow, but this method is difficult in practice on account of the rapid fluctuations of the voltage. It will be sufficient in most cases to make the measurements with a voltmeter of very high resistance so that the current passing through the electrodes will be very small. It should be emphasized that such measurements should be made by experts only, as deviations from the right method which seem of no importance often give useless results. In order to be able to test the potential at the return points of the rail system of a given territory, pilot wires are to be connected to these points and carried to a central testing place. the rail network must be retested. The rail bonds and bridge connections are to be retested once yearly by means of a suitable rail joint tester and must be arranged so that they fulfill the rules of Sections 1 and 2. Connections, the resistance of which has been found greater than that of an uninterrupted rail of ten meters length, must be repaired to comply with these rules. The control of the drop in potential in the whole network would be best assured by the installation of test wires from one of the buses to all points of probable highest and lowest rail potential, which arrangement admits of immediate measurement of potential between these points. In certain cases, especially in existing plants, the installation of such test wires would involve great cost. Such test wires from all of the important rail points were not required; but it has been ruled that all points of the rail network, to which cables of the same district are now connected,, are to be provided with test wires which have to run to some central point where readings of the differences of potentials between the return points can be taken. Wherever the expense involved permits, it is recommended to install test wires not only to the return points but also to the points of highest rail potentials. After permanent changes in the operation, the distribution of the potential in the rail network is to be investigated in the same way as after the inauguration of the plant, in order to ascertain whether the new conditions still correspond to the rules. In case of temporary changes of short duration in the whole network or parts of the same as, for instance, occasionally some festival, change or repair of tracks, fairs, exhibits, etc., no special measures are to be taken because the short duration of the influence will cause no noticeable damage even when the limits of these rules are exceeded. losses of energy. For these measurements an apparatus may be used which allows of the comparison of the drop in potentials across the joint with one of the adjoining uninterrupted rails so that the measurement may be taken during the operation. Joints of a resistance higher than that of an uninterrupted rail of 10 m. length are immediately to be repaired. The total resistance, as found by the measurement of the single joints, must not exceed the value which has been assumed during the projection of the plant (compare Section 2, paragraph 2). Should it result during operation that rail joints are of a higher resistance than that assumed in the designing, it is permissible to abstain from a reconstruction of the joints as long as the permissible difference of potentials in the rails is not exceeded, even with these higher resistances. The established limits of 20% increase of the resistance of the uninterrupted rail by the bonds must not be exceeded in any case. CIRCULAR AND ORDER OF THE MINISTER OF PUBLIC WORKS (FRANCE) OF MARCH 21, 1911, ESTABLISHING THE TECHNICAL CONDITIONS WHICH ELECTRICAL DISTRIBUTION SYSTEMS MUST SATISFY IN ORDER TO CONFORM TO THE LAW OF JUNE 15, 1906. Right of Way. When the rails are used as conductors, all necessary measures should be taken to guard against the harmful action of stray currents, on metallic structures, such as the tracks of railways, the water and gas pipes, the telegraph or telephone lines and all other electric conductors, etc. To this end the following regulations shall be applied: 1. The conductance of the tracks shall be known to be in the best possible condition, especially in regard to the joints, whose resistance should not exceed, in each case, that of 10 meters of the normal track. The management is required to verify periodically this conductance and to place the results obtained on file, which shall be accessible to the administration upon demand. 2. The drop in potential in the rails, measured upon a length of track of 1 kilometer taken arbitrarily upon any section of the system, should not exceed an average value of 1 volt for the operating period of the normal car schedule. 6. As long as no metallic structure is in the neighborhood of the tracks, a drop in potential greater than that fixed in paragraph 2 may be allowed, upon the condition that no damage will result, and particularly no trouble to telegraphic or telephonic communication, and none to railway signals. 7. The owner of the distribution system shall be required to make the installations necessary to enable the administration to verify the fulfillment of the provisions of this article; it should particularly provide, whenever necessary, for pilot wires to be installed between designated points of the distribution system. Protection oj Neighboring Aerial Lines At all points where the lines feeding the traction system cross other distribution lines, or telegraph or telephone lines, the supports should be established with a view to protect mechanically these lines against contact with the aerial conductors feeding the traction system. Regulations 1. Any dynamo used as a generator shall be of such pattern and construction as to be capable of producing a continuous current without appreciable pulsation. 2. One of the two conductors used for transmitting energy from the generator to the motors shall be in every case insulated from earth, and is hereinafter referred to as the "line"; the other may be insulated throughout, or may be uninsulated in such parts and to such extent as is provided in the following regulations, and is hereinafter referred to as the "return." NOTE: The Board of Trade will be prepared to consider the issue of regulations for the use of alternating currents for electrical traction on application. 3. Where any rails on which cars run or any conductors laid between or within three feet of such rails form any part of a return, such part may be uninsulated. All other returns or parts of a return shall be insulated, unless of such sectional area as will reduce the difference of potential between the ends of the uninsulated portion of the return below the limit laid down in Regulation 7. 4. When any uninsulated conductor laid between or within three feet of the rails forms any part of a return, it shall be electrically connected to the rails at distances apart not exceeding 100 feet by means of copper strips, having a sectional area of at least one-sixteenth of a square inch, or by other means of equal conductivity. 5. (a) When any part of 'a return is uninsulated it shall be connected with the negative terminal of the generator, and in such case the negative terminal of the generator shall also be directly connected, through the current-indicator hereinafter mentioned, to two separate earth connections which shall be placed not less than 20 yards apart. (b) The earth connections referred to in this regulation shall be constructed, laid and maintained, so as to secure electrical contact with the general mass of earth, and so that, if possible, an electromotive force, not exceeding four volts, shall suffice to produce a current of at least two amperes from one earth connection to the other through the earth, and a test shall be made once in every month to ascertain whether this requirement is complied with. (c) Provided that in place of such two earth connections the Company may make one connection to a main for water supply of not less than three inches internal diameter, with the consent of the owner thereof, and of the person supplying the water, and provided that where, from the nature of the soil or for other reasons, the Company can show to the satisfaction of the Board of Trade that the earth connections herein specified cannot be sions of this regulation shall not apply. (d) No portion of either earth connection shall be placed within six feet of any pipe except a main for water supply of not less than three inches internal diameter, which is metallically connected to the earth connections with the consents hereinbefore specified. (e) When the generator is at a considerable distance from the tramway the uninsulated return shall be connected to the negative terminal of the generator by means of one or more insulated return conductors, and the generator shall have no other connection with earth ; and in such case the end of each insulated return connected with the uninsulated return shall be connected also through a current indicator to two separate earth connections, or with the necessary consents to a main for water supply, or with the like consents to both in the manner prescribed in this regulation. (/) The current indicator may consist of an indicator at the generating station connected by insulated wires to the terminals of a resistance interposed between the return and the earth connection or connections, or it may consist of a suitable low-resistance maximum demand indicator. The said resistance, or the resistance of the maximum demand indicator, shall be such that the maximum current laid down in Regulation 6 (I) shall produce a difference of potential not exceeding one volt between the terminals. The indicator shall be so constructed as to indicate correctly the current passing through the resistance when connected to the terminals by the insulated wires before-mentioned. 6. When the return is partly or entirely uninsulated the Company shall in the construction and maintenance of the tramway (a) so separate the uninsulated return from the general mass of earth, and from any pipe in the vicinity; (b) so connect together the several lengths of the rails ; (c) adopt such means for reducing the difference produced by the current between the potential of the uninsulated return at any one point and the potential of the uninsulated return at any other point; and (d) so maintain the efficiency of the earth connections specified in the preceding regulations as to fulfill the following conditions, viz: (I) That the current passing from the earth connections through the indicator to the generator or through the resistance to the insulated return shall not at any time exceed either two amperes per mile of single tramway line or five per cent of the total current output of the station. 7. When the return is partly or entirely uninsulated a continuous record shall be kept by the Company of the difference of potential during the working of the tramway between points on the uninsulated return. If at any time such difference of potential between any two points exceeds the limit of seven volts, the Company shall take immediate steps to reduce it below that limit. 9. Every electrical connection with any pipe shall be so arranged as to admit of easy examination, and shall be tested by the Company at least once in every three months. 10. Trie insulation of the line and of the return when insulated, and of all feeders and other conductors, shall be so maintained that the leakage current shall not exceed one hundredth of an ampere per mile of tramway. The leakage current shall be ascertained not less frequently than once in every week before or after the hours of running when the line is fully charged. If at any time it should be found that the leakage current exceeds onehalf of an ampere per mile of tramway, the leak shall be localized and removed as soon as practicable, and the running of the cars shall be stopped unless the leak is localized and removed within 24 hours. Provided that where both line and return are placed within a conduit this regulation shall not apply. 11. The insulation resistance of all continuously insulated cables used for lines, for insulated returns, for feeders, or for other purposes, and laid below the surface of the ground, shall not be permitted to fall below the equivalent of 10 megohms for a length of one mile. A test of the insulation resistance of all such cables shall be made at least once in each month. are both laid underground. 13. In the disposition, connections, and working of feeders, the Company shall take all reasonable precautions to avoid injurious interference with any existing wires. return, respectively. 15. The Company shall adopt the best means available to prevent the occurrence of undue sparking at the rubbing or rolling contacts in any place and in the construction and use of their generator and motors. 16. Where the line or return or both are laid in a conduit the following conditions shall be complied with in the construction and maintenance of such conduit. (a) The conduit shall be so constructed as to admit of examination of and access to the conductors contained therein and their insulators and supports. (b) It shall be so constructed as to be readily cleared of accumulation of dust or other debris, and no such accumulation shall be permitted to remain. (c) It shall be laid to such falls and so connected to sumps or other means of drainage, as to automatically clear itself of water without danger of the water reaching the level of the conductors. (d) If the conduit is formed of metal, all separate lengths shall be so jointed as to secure efficient metallic continuity for the passage of electric currents. Where the rails are used to form any part of the return they shall be electrically connected to the conduit by means of copper strips having a sectional area of at least one-sixteenth of a square inch, or other means of equal conductivity, at distances apart not exceeding 100 feet. Where the return is wholly insulated and contained within the conduit, the latter shall be connected to earth at the generating station or sub-station through a high resistance galvanometer suitable for the indication of any contact or partial contact of either the line or the return with the conduit. (e) If the conduit is formed of any non-metallic material not being of high insulating quality and impervious to moisture throughout, the conductors shall be carried on insulators, the supports for which shall be in metallic contact with one another throughout. (/) The negative conductor shall be connected with earth at the station by a voltmeter and may also be connected with earth at the generating station or substation by an adjustable resistance and current-indicator. Neither conductor shall otherwise be permanently connected with earth. (g) The conductors shall be constructed in sections not exceeding one-half a mile in length, and in the event of a leak occurring on either conductor that conductor shall at once be connected with the negative pole of the dynamo, and shall remain so connected until the leak can be removed. (h) The leakage current shall be ascertained daily, before or after the hours of running, when the line is fully charged and if at any time it shall be found to exceed one ampere per mile of tramway, the leak shall be localized and removed as soon as practicable, and the running of the cars shall be stopped unless the leak is localized and removed within 24 hours. 17. The Company shall, so far as may be applicable to their system of working, keep records as specified below. These records shall, if and when required, be forwarded for the information of the Board of Trade. TAKEN: (1) The rails of each one of the tracks are bonded by welding or by connections formed of short copper cables or of equivalent cables made of some other metal, the section of which having to exceed 100 square millimeters per track, and shall be made as large as possible. (3) In case the official inspector should deem it necessary, a cable will have to be stretched in every line, which will have to be intimately connected with both tracks, and (4) The dimensions of all cables and wires constituting such system will have to be calculated upon a basis that the potential difference between the generator terminals and the point of the tracks remotest from them will not exceed an amount of seven volts. PROBLEM The Committee's conception of an engineering solution of the electrolysis problem is that the railway system and the systems of underground structures shall be so designed, constructed, maintained, and operated, that the entire problem, caused by the presence of stray currents in the earth, including corrosion of structures, fire and explosion hazards, heating of power cables, and operating losses and difficulties, is solved in the most economical way. The Research Sub-committee of the American Committee on Electrolysis, in its investigations, has been constantly confronted with the difficulty that available methods of electrolysis testing do not yield directly, definite information as to the electrolytic condition of the affected structures. An electrolysis survey, to be conclusive must, in some cases, show the true polarity of pipe or cable with respect to earth and in other cases it must show the actual density of the current flowing from pipe to earth in any particular locality under investigation, but to determine such polarity, or intensity of current flow, is very difficult. The existing methods of making electrolysis surveys include, among others, measurements of potential differences between pipes and earth, but such measurements, as ordinarily made, are often quite misleading. At the present time, therefore, the results that follow the application of any particular method of electrolysis mitigation are sometimes open to question because of the lack of adequate test methods. It is evident therefore, that the development of improved means of electrolysis testing whereby the actual current density of discharge from pipes to earth at any point can be measured is an important preliminary step toward securing definite information on which the solution of the outstanding questions relating to electrolysis protection can be based. The Research Sub-committee now has under investigation certain new methods of electrolysis testing which offer considerable promise in this direction and it is felt that a thorough study and development of these should be made in the hope of obtaining improved test methods and equipment that will facilitate securing the information required. It is desirable that these investigations precede further experimental work relating to methods of mitigation. 2. Effect of Different Rail Voltage Drops. It is important to examine the resulting conditions, from an electrolysis standpoint, of different values of voltage drop in rails, particularly in cities or localities where such voltage drops are low, and comparable to those which correspond to maximum economy from the railway standpoint, taking due account of variations in physical conditions in different localities. 3. Studies of Electric Railway Power Distribution. Studies should be made of the costs of various measures designed to minimize track drops in order to determine which measures, if any, are best to apply. The application of automatic and semi-automatic substations to street railways should be given consideration to determine how far the voltage drop in the rails can be reduced with such a system when developed to the economic limit. In making these cost studies track networks should be selected where the layout is both favorable and unfavorable for such installations. Studies might also be made of the joint application of insulated negative feeders and automatic substations to determine what values of voltage drops in the rails can be obtained at reasonable cost. 4. Study of Mitigative Measures Applicable to Affected Structures. After applying mitigative measures to the railway system, it may be found that in many cases it will still be necessary to reduce further the hazards to underground structures. It is therefore important to study methods of mitigation applicable to the structures themselves, and particularly the quantitative effect of insulating joints in protecting pipes and cables and the application and maintenance of such a drainage system as will keep all underground structures negative to the earth without involving fire and explosion hazards, and assuming in both cases the railway stray current at a low value. Earth. At the present time there is no reliable criterion as to the actual hazard to underground pipes unless they are at all points negative or neutral to earth at practically all times. Wherever pipes are 186 ELECTROLYSIS RESEARCH positive to earth, it is impossible with the present methods of testing to determine the actual degree of corrosion hazard. If however, the development work in connection with methods of measuring current discharge from pipes mentioned in a preceding paragraph should result favorably, it appears probable that such test methods could be used for the purpose of establishing a fairly accurate criterion for a safe condition of underground structures. The Committee feels that this question should be investigated carefully so that anything possible of accomplishment in this direction may be realized. 6. Self Corrosion. When iron pipes are embedded in certain soils, corrosion due to soil conditions or local galvanic action often results in greater or less degree. This phenomenon is commonly known as self corrosion. Obviously, it is of importance to differentiate between the effects of corrosion due to the action of chemicals in the soil and that due to stray currents, in order that an intelligent procedure can be adopted for remedying the trouble. It is believed that a thorough and systematic study of the question of soil corrosion on cast iron, wrought iron and steel pipes would bring to light information that would be of great value in dealing with the electrolysis problem. Such investigations in order to be of much value should be extended over a period of years. 7. Fire and Explosion Hazards on Gas and Oil Pipes. In addition to preventing corrosion, there is the closely related problem of protecting against fires and explosions due to electric currents on gas or oil pipes. At the present time no definite information is available as to what limiting currents can safely be permitted on such pipe systems. It is important to investigate this question, both statistically and experimentally in order to evaluate this hazard. 8. Heating of Power Cables Due to Stray Currents on Sheaths. In view of the fact that it is common practice to electrically drain the lead sheaths of power cables to protect them from corrosion, and since the currents on the sheaths may be of considerable magnitude, reducing the current carrying capacity of the conductors, it is important to determine the limitations that should be imposed on such currents in order not to cause serious heating, and hence undue reduction in current carrying capacity of the cables. Summary. As the Committee now views it, a research of some magnitude is necessary to secure further information needed for an engineering solution of the problem, to comprise the following: 1. Development of practical means for measuring current density across contact surfaces of pipes and earth. Such measurements are especially necessary if structures are not kept negative to earth. 2. Development of practical means for accurately determining the polarity of structures and adjacent earth, in such a way as to eliminate galvanic effects. 3. Study of the relation of different values of voltage drop in the track to stray current from rails, including the large variations of this relation under different conditions, and the effects of such stray currents on underground utilities and railway structures. 4. Cost studies of street railway systems and different methods of power supply to determine the minimum values of track voltage drop consistent with economic operation in various locations. pipes and cables, assuming railway stray current at low values. 6. Detailed study of the application and maintenance of such a drainage system as will keep all underground structures negative to earth. Such studies to include the effect of drainage on corrosion of subsurface and railway structures and its effect on producing fires and explosions. 7. Comparison of 5 and 6. 8. Investigation of the distribution of current flowing from pipe to adjacent earth for the purpose of determining whether a diversity factor can be established, i.e., the relation between maximum and average current density. entirety. This bibliography may be considered as a selected list of such contributions to the subject known to the committee as in its opinion are of the most importance at the present time. The committee, however, does not sponsor the articles here listed nor does it present them as comprising a complete discussion of the subject. Electrolysis Surveys and Their Significance. Report of the 1920 Electrolysis Committee of the American Gas Association, L. A. Hazeltine, Chairman. Technical Section Sessions. A. I. E. E., 1907. Vol. 26, part I. Influence of Frequency of Alternating or Infrequently Reversed Current on Electrolytic Corrosion. Burton McCollum and G. H. Ahlborn. Bureau of Standards Technologic Paper No. 72, 1916. Modern Practice in the Construction and Maintenance of Rail Joints and Bonds in Electric Railways. E. R. Shepard, Bureau of Standards Technologic Paper No. 62, 1920. H. Farnham. Cassiers Magazine, August, 1895. Some Theoretical Notes on the Reduction of Earth Currents from Electric Railway Systems, by Means of Negative Feeders. George I. Rhodes Trans. A. I. E. E., Vol. XXVI, p. 247, 1907. Insulating Pipe Coverings Comparative Values of Various Coatings and Coverings for the Prevention of Soil and Electrolytic Corrosion of Iron Pipe. Robert B. Harper, Proc. Illinois Gas Association. Vol. 5, 1909. Also American Gas Light Journal, v. 91, 1909. Pro. Am. Gas Inst. about same date. Surface Insulation of Pipes as a Means of Preventing Electrolysis. Burton McCollum and 0. S. Peters, Bureau of Standards Technologic Paper No. 15, 1914.	68,913	common-pile/pre_1929_books_filtered	reportofamerican00amerrich	public_library	public_library_1929_dolma-0020.json.gz:3462	https://archive.org/download/reportofamerican00amerrich/reportofamerican00amerrich_djvu.txt
XgTdXRpLnxO2X9rA	Foundations of Chemical and Biological Engineering I	31 Pxy Diagram Learning Objectives By the end of this section, you should be able to: Read Pxy diagrams for binary mixtures Find bubble points and dew points on a Pxy diagram Calculate the mole fraction of substances in the vapour and liquid states The following diagram is the Pxy diagram for a benzene-toluene mixture at a constant temperature of 373K. They y-coordinates show the pressure of the mixture and the x-coordinates show the mole fraction of benzene in liquid and/or vapour phases. Higher pressure forces molecules to come closer together, which causes the molecules to be more likely to condense from vapour to liquid. From top to bottom, the regions are liquid region, vapour-liquid equilibrium region, vapour region, which is the opposite from the Txy diagram: Suppose we have a mixture with 0.5 mole fraction of benzene at a pressure of 0.5 bar, and we slowly increase the pressure while keeping the temperature constant at 373K. We can locate our starting point using the pressure and mole fraction of benzene: The point is fully in the vapour region, which means the mixture of benzene and toluene is in the vapour phase at a pressure of 0.5 bar and temperature of 373K. As we keep increasing the pressure, the point will hit the first curve on the boundary of the vapour region. This point is the dew point of the system. At the dew point, the first drop of liquid is being formed. The composition of the first liquid can be found using the x-coordinate of the point on the other curve where the pressure is the same. If we keep increasing the pressure while keeping the temperature constant, the point will move up into the vapour-liquid equilibrium region. Similarly to the Txy diagram, we can read the mole fraction of benzene by drawing a horizontal line through the point and reading the x-coordinate where the line hits the two curves. As the pressure goes up, the system will hit the bubble point, where the last drop of vapour condenses into a liquid. Notice that the line connecting all the bubble points at different mole fractions appears to be linear. We can show why this occurs using Raoult’s law: Starting with the total pressure in the system being the sum of individual partial pressures, we replace each partial pressure with the liquid mole fraction and vapour pressure (using Raoult’s law): \begin{align} P=p_{1}+p_{2} & =x_{1}×p^_{1}(T)+x_{2}×p^_{2}(T)\\ & =x_{1}×p^_{1}(T)+(1-x_{1})×p^_{2}(T)\\ &= x_{1}×[p^_{1}(T)-p^_{2}(T)]+p^_{2}(T) \end{align} This equation is in a linear form, where [latex][p^_{1}(T)-p^_{2}(T)][/latex] is the slope and [latex]p^_{2}(T)[/latex] is the y-intercept. Because the Pxy diagrams assume constant temperature, the vapour pressures are constant. When we raise the pressure of the system over the dew point, the system will stay fully in the liquid region. There will be only liquid in the system and the composition of the liquid will be equal to the overall system composition. Feedback/Errata	626	common-pile/pressbooks_filtered	https://pressbooks.bccampus.ca/chbe220/chapter/pxy-diagram/	pressbooks	pressbooks-0000.json.gz:33599	https://pressbooks.bccampus.ca/chbe220/chapter/pxy-diagram/
hPO597NjQ_K5BYDA	First lessons in physics.	PREFACE. The conviction that an elementary knowledge of some important instruments, machines and physical phenomena can and should be given in our Common Schools, has induced the author to prepare the present little volume. Its object is the presentation of a number of phenomena, laws, and applications of the same, specially adapted to the perceptive capacities of the pupils of the upper grades. Inasmuch as the demand of a large amount of time might delay the introduction of physical science into the Common School, the book has been so prepared as to secure good results in the minimum of time ever given any study in our schools, viz. : one lesson a week. Each of the thirty-nine lessons commences with a fact familiar to the child, or an easy ', little experiment, which serves as the basrs for the development of a natural law. After this law, comes the application man makes of it — such as the barometer, thermometer, pump and hydrostatic press. Costly apparatus is unnecessary. The steam engine and other complicated machines should be examined when in actual use at the workshop or other places, by the class in company with the teacher, but not until after the preparatory lesson in the school-room. Like all instruction, instruction in physics should proceed in concentric circles from the near to the remote. The present volume may be considered as the first and smallest of those circles. Its usefulness in the highest grade of our Common Schools has been shown by practical experience ; the author has written it, however, with a view of introducing it into the second, and even into the third. At the end of every lesson, articles in books and popular magazines are pointed out, where the pupil may find interesting reading matter ; and where, while thus improving his leisure time, he may collect material for composition exercises in school. Preface to the Third Edition. The hearty welcome given to the first edition of this work undoubtedly had its reason in the long-felt want of a text-book suitable for the thousands of girls and boys whose school education ends in the common school. Among the many things there learned, there are few things which they remember to greater advantage than the phenomena and daily applications of the laws of gravitation, the pressure of air, the lever, the pump, the steam-engine, and the telegraph. These realities train the observing powers, instill a love for knowledge, form a preventive against habits of superficial reasoning, and thus tend to diminish explosions, conflagrations, and other calamities, many of which are caused by persons ignorant of the powers of nature. The merchant, the laborer, or the manufacturer will do his work the better for having had his senses trained in observing nature's operations, and his mind disciplined by scientific thought. It may safely be stated that this view is held by most educators in this country, and that the time is fast approaching when physical science will no longer be a stranger in our common schools. And yet there are a few followers of the cramming-system, who would deny the right of nature to a share in the education of the young; who would not teach about the things themselves, but merely their names »nd forms. These persons consider objective instruction in the lower grades of schools as simply a transient concession to ephemeral demands, although, during the last two centuries, such men as Cowley, Milton, Locke, Rousseau, Pestalozzi, Whewell, and Macaulay have advocated it. In the upper grades they refuse it admission altogether, notwithstanding its introduction there is urgently pressed by the scientific men of all countries, by the entire periodical press, and the most prominent educators of the world. physical science into the schools, but who fear, lest the appropriation of time — one lesson a week ! — might diminish the habitual number of arithmetical examples, geographical names, and grammatical rules, and thereby vitiate the results of the annual examinations. So some people entertain a groundless prejudice against the acquisition of a foreign language, on the plea that the child's English might suffer. Huxley, in his "Answers to Certain Questions by the Schools Inquiry Commission," says : " Physics lie at the foundation of all science ; and if nothing else were taught, it -would be a great gain to have the youth of this country soundly instructed in the laws of the elementary forces — gravitation, heat, light, and«so forth." An English Journal, " Nature," says : " The notion, that when a child has learned to read, write, and cipher, he is educated, must be eradi'zted. These are at best but means, and are only the instruments by which education is conducted." An editorial in the "Scientific American" (January 14, 1871), ends with the following significant words : " As object teaching is a mere handmaid of science — is of use only to give scientific habits of 'thought, and to convey a knowledge of scientific facts, and is worthless without science, the pnblic should see that its introduction into our schools be carried on under the advice of scientific experts, who shall direct what is best to be taught, and advise with the adepts in teaching how such knowledge may best be imparted. As a journal having the interests of science and education at heart, desiring to see science soundly popularized, and the masses made acquainted with its technical value, we make this suggestion, and furthermore ask: Is there any man of- scientific attainments in the present Board of Education ? Is there any scientific authority upon its general staff? " Physical science was introduced into the B and C grammar classes of this city last September ; the pupils have now been using First Lessons in Physics for several months, and none of their other studies have been curtailed, yet the average of the monthly examinations does not suffer on that account, and, in the opinion of our teachers, it never will. A peculiar feature connected with the use of this book— one which we trust will not be brought forward as an objection — is, that the children ask a great many questions more or less to the point ; and that they find no rest until they have received a satisfactory answer, either from the teacher's experiments or their own. The fact is truly surprising, that the pupils of the C grade (sixth school-year) passed a very fair examination a few days ago, on questions at the end of the book which were not found too easy for the C grade of the High- school (the tenth schoolyear). This shows what earnestness may accomplish ; and we have but begun It may be well to state that the modern technical sense of a word sometimes conflicts with its preconceived English meaning, or use; and as a book of this kind demands language both youthful and technical, the author may be excused for having given a slightly different dress to not a few of the laws. He has omitted several of the so-called "properties " of matter which are very puzzling to the young; and, for the sake of simplicity, has treated the somewhat magic "impenetrability" of air as elasticity of air. The independent terms, Force, Motion, and Heat, are better understood by young pupils than Expansive Force, Moving Force, and so forth. The text in fine print, as well as pages 83, 84 and 120, must be omitted in a lesson of less than aitf-hour's length. The development of the steam-engine will find favor from those appreciating the historical element in the schooL While the lessons in Optics may claim special clearness in treatment, those in Chemical Electricity, being very difficult for young learners, will need forbearance. A twofluid element was chosen, because it may be seen in actual use at the telegraph office. The questions in fine print serve for reviews and examinations, but not as equivalents for experiments. Even a brief perusal of the volume will show the author's intention not to cram the pupil with meaningless facts, to be forgotten as rapidly as they are learned. As no special scientific qualification has been required of the teacher who, to-morrow, may be called upon to impart scientific instruction to her class, a text-book in the hand of the pupil seems for the present a necessity. I earnestly hope that my feeble contriburion to so great a cause may not be judged by its shortcomings alone, and that the day may soon come when physical science shall form GRAVITY. i. EXPERIMENT. — A stone in our hand does not fall, because the hand supports it. But if the hand is withdrawn, the stone falls, and continues to fall, until prevented from falling far- ground. Familiar Facts.— Chalk, pencils, paper, pens, and India-rubber, often fall from the desk upon the floor. A stone thrown into a pond sinks to the bottom ; a sign-board blown off by the storm falls upon the side-walk; rain, snow, and hailstones, descend to us from the clouds ; and large bodies of water, when precipitated from high rocks, form waterfalls. A cat may fall from a house-top ; a careless child tumbles down stairs ; coals fall through the grate ; meal falls through the sieve, and soot through the air. Branches of fruit-trees, hanging full with fruit, break off and fall to the ground ; the lily, whose stem is broken, droops its head ; the mighty oak in the Western forests, groaning under the blows of the settler's ax, falls with a crash to the ground. Heavy rods are attached to maps and curtains, to draw them down. Clocks are provided with weights, which move slowly in a downward direction; the heavy anchors of vessels plunge into the depths of the ocean. Having noticed these facts, you naturally inquire, " Why is it that all bodies near the earth have a tendency to approach the earth ? " As every State and every town has its laws, so Nature has her laws, which all bodies must obey. All the facts given above may be comprised under the law: All bodies fall, if unsupported; they are attracted to the earth. The force which attracts them is called the Force of Gravity.1 not supported by my hand (Fig. 1). It is merely suspended. What prevents it from falling ? The string. When you draw the stone a little to one side, it moves back again; it wants to stay in one place. And, observe, that the string is kept straight. The string indicates the direction in which the stone would fall, if it were left free to do so. This direction is vertical. Who does not know the plumb-line used by carpenters and bricklayers ? I. That a body, instead of approaching the earth, may sometimes do the opposite, that is, ascend into the air, is due to the influence of other forces. Thus, when a boy leaps a few feet high, he succeeds in overcoming gravity ; however, he does so only for a few moments at a time. Birds and winged insects can overcome gravity longer by means of an action peculiar to them, which we call flying. An ordinary fly makes as many as five hundred beats with its wings during a second. But as soon as the influence of other forces ceases, the body must obey the law of gravity. The powerful eagle excels in swiftness the fastest locomotive ; yet, when pierced by a deadly shot, he drops like a stone to the hunter's feet. 12 FIRST LESSONS IN PHYSICS. 3. EXPERIMENT. — Place a large book upon the hand; the hand will be pressed downward. If a small book be taken, the downward pressure is much less. The small book has not as much weight as the large one. Familiar Facts. — A large stone presses itself into the ground. The weight of a heavy wagon makes deep ruts in a road. When ladies buy silk robes, they lift the article on their hands. Do you know why ? is called their weight. 4. EXPERIMENT. — A rod balanced on the edge of the hand has equal weight on each side of the support. The direction of the rod is level, or horizontal. Now, let a crayon be suspended from each end. The rod will still be horizontal, because both crayons have like weight ; they are attracted to the earth with the same force on either side. If a number of crayons be suspended from one end of the rod, and a standard of weight, such as i, £ or 1 lb., from the other, we have a crude form of the scale, or balance. A balance is an instrument for weighing. The pieces of iron, brass, or lead, used as standards, are the weights. Instead of the edge of the hand, a metal pivot is used. At each end of the beam a pan is suspended. When a person buys a pound of sugar, why does he see that the beam of the balance is horizontal ? Did it ever enter your mind that, when buying a pound of sugar, you actually bought a quantity of sugar whose force of gravity amounted to a pound? That is, you bought a mass of sugar which is attracted by the earth to the amount of a pound. It matters not to gravity of what kind a substance is. A pound of coffee is as heavy as a pound of lead ; a pound of feathers, as a pound of iron. Treatise on Natural Science. New York : Chr. Schmidt, 39 Centre st. Gravity, as we have seen, is the force which attracts all bodies to the earth. This force is only a portion of the universal force of attraction between all bodies on the earth as well as in the universe (planets and fixed stars). A pound- weight has very nearly the same weight all over the earth; but if taken to the moon it would have less weight; it would weigh only about }/§ of a pound there. On the sun, which contains 355,000 times as much matter as our earth, the pound would have the weight of about 28 pounds. Owing to that universal force, the planets revolve around the sun. The force with which the sun and moon attract our earth causes the huge tide-waves on the ocean ; while the earth's attraction for the moon causes this planet to revolve around the earth about once every four weeks. OF SOLIDS. 5. EXPERIMENT. — Take two ink-wells of the same size. Fill the one with water, the other with oil, and place them on the pans of a balance. The one containing the water will be found to be depressed ; evidently the water has more weight than the same bulk of oil. In common words we say, water is heavier than oil ; but we ought to say, that water has greater specific weight than oil ; that is, a bulk of water has more weight than the same bulk of oil ; or, water is denser than oil. For is not a pound of water as heavy as a pound of oil? Specific Gravity is the weight of a substance compared with the weight of a like bulk of some other substance taken as a standard. 6. EXPERIMENT. — Now first pour the oil into a tumbler, and then the water. The latter being the heavier, it settles in the bottom, the oil rising above it. Thus oil floats on water, because it has not as much weight as the same bulk of water. Familiar Facts. — Smoke rises high into the air; balloons ascend into the clouds. Each is lighter than a like bulk of surrounding air. SPECIFIC GRAVITY. 15 Fluids of different specific gravity place themselves in the order of their specific gravity — the heaviest below, the lightest above. 7. EXPERIMENT.— Drop a stone into a tumbler filled with water; it sinks. A piece of cork would float. Upon one pan of a balance place a tumbler filled to the brim with water ; upon the other place as many weights as are necessary to establish equilibrium. Remove the tumbler and drop a stone into it. The stone will sink and some water will run over. The space now occupied by the stone was before occupied by water, and th.at quantity of water was borne by the water in the tumbler. Now, if the stone had no greater weight than a like bulk of water , it would likewise be borne by the water. That it has, can easily be shown by placing the tumbler with the stone in it on the balance again ; the tumbler will have more weight than it had before. 8. EXPERIMENT.— An empty flask, closed with a cork, floats on water. Look how little water it displaces. It evidently has less weight than a like bulk of water. It would float even if it contained a few pebbles, while a bottle filled with water sinks. Familiar Facts. — As the flask, so do vessels float, though they be heavily laden. The body of a man has scarcely more weight than a like bulk of water, and will float on water, provided the chest remains filled with air. Frightened by this, they lose their presence of mind, and, instead of holding their breath, they exhale the air from their lungs. Thus they diminish their volume, and are, of course, more apt to sink. Then they foolishly extend their arms into the air; the head then naturally sinks, and, unless rescued, they are drowned. The danger would have been very slight if these persons, on falling into the water, had first held their breath, spread out their limbs, and then quietly folded their arms over the crown of the head. For, by throwing the head slightly backward, a person is enabled to keep his mouth and nose above water, and thus may save his life. If the waves run high, he must, by all means, hold his breath as long as he is submerged; then no water can enter his mouth. Application. — By means of specific gravity the purity of liquids and the value of substances, such as gold-quartz, can be ascertained. string. The direction of the string will be vertical (Lesson 2). But if we bring a magnet near the nail, the string will incline toward the magnet ; the more so, the nearer the magnet is brought to the nail. On approaching it still nearer it will attach itself to the magnet, and, if detached, contrary to gravity, will not fall. This is owing to Magnetic Attraction. Reverse the last experiment. Suspend the magnet at one of its ends, and lay the nail on the table. Holding the nail with one hand so as to keep it steady, the magnet will be seen to move toward the nail and adhere to it in spite of gravity. This shows that Magnets and unmagnetic iron attract each other. 10. EXPERIMENT.— If iron filings be placed on a piece of paper or glass, they will likewise be attracted by the magnet. The latter need not be in contact with them ; it may be placed under the paper, or even under the table. Magnetic attraction, like attraction of gravity, operates also through intervening bodies. Let the magnet be placed lengthwise in the iron filings and turned round several times. On withdrawing it we find that it is covered at the ends with long threads of the filings, while toward the middle they become shorter, and in the center of the magnet the attraction is so slight that no filings adhere. From this we see that the power of a magnet resides chiefly at its ends. vibrate, and after many vibrations, resume the same position. It will do so anywhere, in the room or out-doors. Upon examining the direction, we find that it is north and south. That end of the magnet which points north is called its north pole, that which points couth, its south pole. MAGNETIC ATTRACTION. 19 seen, if the south poles are brought together. The magnets will not come to rest before the north pole of the one has found the south pole of the other. other. Application — The most important application of this property of the magnet is the Magnetic Needle, or Compass, used by surveyors and mariners. A needle may easily be rendered magnetic by means of a magnet. Lay a needle upon the table and hold its point with the left hand. Taking the magnet with the right, place it with its north pole upon the center of the needle. Then pass it slowly along the right-hand part of the needle, rubbing the needle in the direction from the center to the eye. When arrived at the eye, the magnet must be raised from the needle and passed through the air back to the center, there to recommence the same operation with the same pole. This process must be repeated about thirty times. After that, the magnet is reversed, taken into the left hand, and, while the right now holds the needle, placed upon the center of the needle. By rubbing the magnet from the middle of the needle to the left end, returning through the air, and repeating this the same number of times as the first process, the needle becomes a perfect magnet. It will attract iron, and be attracted by the same ; it will point north and south, if suspended at the middle and if left to move freely. The ancient Greeks gave amber the name of Electron ; they knew that if amber was rubbed it would attract small, light bodies. This attractive power is called Electricity. a bar of sulphur, or a lamp-chimney, with a piece of flannel, and bring it near light bodies, such as tiny bits of paper, wafers, or small feathers. They will adhere to the sealing wax, sulphur or glass, which have become electric, and have now the power of attracting light bodies. 14. EXPERIMENT. — Heat a piece of writing paper over a stove or lamp. From this we see that Friction produces Electricity, and that electric bodies attract light bodies. where there are but few persons, and where the atmosphere is perfectly dry, we bring the knuckle near electrified sulphur, glass or paper, we may see a spark pass from the substance to the hand.1 At the same time, we also hear a crackling noise, feel a slight stinging in the hand, and smell a peculiar odor near the electrified object. Familiar Facts. — The fur of a cat sparkles when rubbed with the hand in cold weather. The sparks are seen best in the dark. If the electric paper be held against one's face, a peculiar sensation is felt, as though the face were being covered with a cobweb. The reason of this is, that the fine hair on the face is attracted by the paper and caused to move. Sparks a foot long are often seen when there is strong friction between the rubber bands and the wheels of a machine. But what has become of the electricity uiat passed from the sulphur, or glass, to the knuckle while emitting a spark ? If it had remained there, the knuckle would certainly attract light bodies ; but this is not the case. Neither the knuckle nor the hand shows any sign of electricity. It spread I. As it often depends upon uncontrollable circumstances whether a spark can be obtained by such simple means, the following contrivance has been suggested: "Take a glass tube of j£-inch bore and a little over a foot long. Then take an iron wire, coil it spirally, and insert it into the tube— the windings should be J^-inch distant from each other, and must rest firmly against the inner surface of the tube. One end of the wire is to protrude from the tube, and a tin ball to be soldered on to the protruding end. The other end of the spiral wire should not extend farther than the middle of the tube, in order that about six inches of the tube may be used as a handle. On rubbing the tube, a spark may be obtained from the tin ball." all over the body and over the earth, and thus ix was sensibly lost. If we bring a key near electrified sulphur or glass, or a tin ball (see foot note p. 21), a spark will likewise be seen passing over to the key ; but the electricity which the key receives does not stay there; it passes into the hand, and thence through the body to the ground. This shows that metals and the human ~body are good conductors of electricity. If in place of the hand and the key, we take sealing wax, silk or glass, no spark will be seen, and they wil) remain electric after the contact. These objects do not conduct electricity. Hence sealing wax, silk and glass are non-conductors of electricity. The difference between conductors and non-conductors of electricity is this : A conductor receives, and loses, electricity immediately on all the parts of its surface. A non-conductor receives, and loses, electricity only at the point of contact. 16. EXPERIMENT.— Suspend a pith ball,1 attached I. " Pith balls may be obtained best yi winter from young elder-trees of one year's growth. The stem is split open with a sharp knife, the pith is cut into small pieces, each of which is rolled between the hands into a ball. To suspend the balls, pierce each with a needle carrying a silk or linen thread, make a knot on the opposite side, and then draw the knot tight a little ways into the ball. The linen thread should be very fine. If silk thread is used, care must be taken that it contain no metallic color, as, for example, Prussic Blue, and that no cotton thread be inside, as cotton is a good conductor. The thread to which the little ball is attached is taken from three to five inches long ; one with a ball at each end should, of course, have double the length. They may be tinues, until the aqueous vapor in the room, or gome other good conductor, or the contact of our hand, deprives the ball of its electricity. On presenting electrified sealing wax, they become electric themselves by contact with it, and then repel each other. They hang no longer vertically ; the attracting and repelling force of electricity may overcome gravity in the same way in which magnetic attraction overcomes gravity. tricity of the glass. 19. EXPERIMENT. —Repeat the 17th Experiment, and after the two balls are separated by repulsion, present electrified glass to one of them. The glass will attract this ball and impart its electricity to it ; after which the ball will be repelled from the glass and at once fly to the other ball. When the two balls had the same kind of electricity, they repelled each other ; now that they possess different electricities — the one glass electricity, the other sealing-wax electricity — they attract each other. 20. EXPERIMENT. — Again suspend two pith balls. Bring electrified sealing wax near the one, electrified glass near the other. This is easily understood if we remember that one ball had glass electricity, and the other seal- I. "Glass differs greatly with respect to electrical purposes. Some varieties are good conductors of electricity, because they contain metal. Hard glass, and common green bottle glass, if not colored with metal, are non-conductors, and, therefore, well adapted for that purpose. All kinds of glass, however, are hygroscopic, that is, they draw moisture from the atmosphere. For this reason thick glass rods are preferable to glass tubes. Before being used, both, tubes and rods, should be slightly heated, and should be rubbed with a warm cloth." ing wax, or, as it is called, resinous electricity. From all this it appears that there are two kinds of electricity — Vitreous or Glass Electricity r, and Resinous Electricity. The former is also called positive electricity, the latter negative electricity. Like electricities repel each other ; unlike electricities attract each other. (For a similar phenomenon see the preceding lesson.) Historical. — The sparks obtained by the rubbing of furs, and lightning, with its companion, thunder, must have been observed by the earliest people upon the earth. Although the Greeks, about 600 years before the Christian era, recorded the attracting property of amber, it was not before the beginning of the lyth century, that a book was published by Dr. Gilbert, an Englishman, who mentions many other substances, such as glass and sulphur, as having the same property. This author stated correctly that magnetism attracted as well as repelled, but, curiously enough, he added that electricity only attracted. In 1670, the first electric machine was constructed by Otto Guericke, burgomaster of Magdeburg, the inventor of the air-pump. He also discovered the property of electric repulsion. He excited electricity by means of sulphur (brimstone) exposed to friction. The distinction between conductors and non-conductors of electricity was discovered by Mr. Stephen Grey. He wished to electrify a cord suspended by linen threads, but was unsuccessful because the electricity, when entering the cord, at once passed over to the threads. The threads thus were found to be conductors of electricity. Upon the suggestion of a friend he tried silken threads, and as silk is a non-conductor, the experiment then met with the desired result. Du Fay distinguished between vitreous and resinous electricity. A number of other scientists afterward improved the electric machine, and by continuous research added largely to the progress of the science. But they were eclipsed by Dr. Franklin who astonished the world by drawing electricity from the clouds. A lamp-chimney yields only a small spark; but the glass disk in an electrical machine, such as is used in High Schools and Colleges, produces a long, zigzag spark, resembling a flash of lightning, It had long been supposed that lightning was an electric phenomenon, but it was not until 1752 that, through the genius of our countryman, Benjamin Franklin, all doubts were removed. Having long been thinking over the subject, he one day saw a boy fly a kite, and the idea at once struck him that he must make one himself and send it into the clouds. Accordingly he stretched a silk handkerchief upon two sticks, in the form of a cross, on the top of which he fastened a pointed iron wire. The hempen string was attached below to a key, and the key was insulated by silk string which Franklin held in his hand. The clouds were passing rapidly, but without any apparent effect upon the kite ; and the two observers, standing below and watching it with great anxiety, were about to abandon the undertaking, when suddenly the fibres of the string bristled up, and a crackling noise was heard. Franklin now presented his knuckle to the key, and received an electric spark, which was soon followed by an abundance of sparks as the string became wet with the falling rain. Franklin's experiment, together with many experiments by scientific men in Europe, demonstrated beyond a doubt, that all rain clouds are electric. approach each other, their electricities try to unite. In doing so, one of them leaps over the space between them. This passage of electricity through the air produces a great electric spark which we call Lightning. Familiar Facts. — Lightning mostly passes from one cloud to another. But it may also pass from the clouds to the earth, and from the earth upward to the clouds. It rarely happens thafc lightning strikes — that is, strikes objects on the earth. Tall objects made of good conducting material are most liable to be struck — tall objects, because they are nearer to the clouds ; good conductors, because electricity can get to the ground soonest through them. High houses, tall steeples, trees or chimneys, therefore, offer a good passage to electricity. In its onward course lightning always prefers the best conductors ; thus it passes along the spouting of houses, along water-pipes, stove-pipes and iron pillars. It melts metallic objects ; it splits trees into fragments, and 'kills living beings by destroying the activity of their nerves. The safest place during a thunder-storm is that part of a room not too near the fire-place, stove, chandelier, gas-pipe or bell-rope. Why is it unsafe to seek shelter under tall trees, or in the entrance of a house with rain pouring down over it? Knowing that lightning always follows the best conductors, Franklin devised a means by which he might direct its course, and invented the Lightning Rod. It consists of a metallic rod, with pointed upper ends, which protrudes several feet above the roof, in order that on the approach of a dense cloud the metallic point, and no part of the building, should be struck. The rod conducts the electricity into the ground, where it can do no harm. As lightning is an electric spark, so is — on a large scale — thunder the crackling noise which accompanies the electric spark. whittle a stick, to sharpen pencils, to split logs, to saw wood or to plane boards, we find it necessary to use instruments, such as a knife, an ax or a saw. We see that the parts of a solid body are not easily separated; evidently they are very close together. They are held together by a force which we call Cohesion. We know that it is difficult to break a piece of iron, because iron has a strong cohesive force ; yet a blow with a poker sometimes may break the door of an iron stove. Rolled or hammered iron is much stronger than cast-iron, because, by the process of rolling or hammering, its particles have been brought nearer together, and hence they cohere more firmly. The strength of our tools and building-material depends upon this cohesive force.1 We can break wood more easily than iron, because it has less cohesive force. Easier yet to break, or separate, I. If iron be made to pass through fine openings, iron wire is obtained. (What is this property of iron called ?) Iron wire of the thickness of a match may support a weight of forty tons. A cable of wires, each wire having one-third of that thickness, may support a weight of ninety tons. — Suspension bridges. is water, oil, or air. Place the hand in water, now try to place it in wood. This is impossible, for the particles of a solid body cohere more closely than those of a liquid. How easily we can pour water from a pitcher into a tumbler, and oil from a can into a lamp ! And that our light- winged songsters can divide the air so swiftly, is owing to the fact that air has even less cohesion than water. We can walk, run, ride or jump in air. To do this in water is more difficult ; in molasses, it would be next to impossible.1 overcome. Familiar Facts.— When a little child breaks his slate, he tries to put the parts together again, but he quickly perceives that they will not remain together; he must get a new slate. The particles on the surface of the edges can not be brought so near to each other as they were before ; that is, they cohere no longer. A broken walking-cane, although the broken parts are glued together again, has lost its former strength. I. When we overcome the force of cohesion of a body, we do so by displacing its parts ; we do not in reality penetrate the body. Thus, in driving a nail into a board, the nail merely displaces parts of the board. A body can not occupy the space of another body unless that other body be first removed; that is, no two bodies can occupy the same space at the same time. If an inverted tumbler be placed in water, the water can not fill it, because the air in the tumbler has no means of escape. See Lesson X. pouring them together. The greater or less resistance which the body offers when being broken, determines the degree of its cohesive force. A solid body has more cohesion among its parts than a liquid. Gaseous bodies have no cohesion at all. The great enemy of cohesion is Heat. Familiar Facts. — Although solids and liquids cohere, they contain a great number of holes, which are called Pores. They may be of different size in the same body, and they may be visible or not. The pores of our skin are so minute that they can not be detected without a magnifying glass. Every square inch of our skin contains about 1,000 pores. Our health depends largely upon their activity.1 Solid and liquid bodies are porous. Application. — (a.) Of Cohesion : Beams and Pillars. Wire; Thread; Rope, &c., &c. (b.) Of Porosity : The Sponge ; Blotting-Paper. I. In the year 1661 the Academy of Florence proved that pores exist even in gold. A thin globe of gold was filled with water, and the orifice carefully closed. A violent pressure was then brought to bear upon it, and the result was, that the water was forced through the pores- of the gold, and stood like dew upon the outer surface of the globe. with a pen-knife so as to form two bright surfaces, and let the two faces be pressed against each other until they are in the closest contact ; they will be found to adhere firmly to each other. Familiar Facts. — The same takes place, if a piece of India-rubber be cut and the two surfaces be pressed together. Dealers in glass-ware know that when mirrors have been placed together with their surfaces, they are often broken in the attempt to separate them. Between solid bodies, adhesion takes place if ike surfaces are highly polished; that is, if they are so smooth that the parts of one surface closely approach those of the other. If not highly polished, the surfaces will not adhere — as two bricks laid together. Nor will adhesion take place, if thin paper is placed between the two polished surfaces. As a general thing, bodies which we wish to adhere to one another, are not very smooth. Owing to the unevenness on their surface, many of the parts of one surface are prevented from coming in close contact with those of the other ; in this case there can be no adhesion. What may be done, then, in order to make two rough surfaces adhere? Simply put a liquid body between the two, to fill out the unevenness. 22. EXPERIMENT. — Put two moistened glass plates together, and it will require some effort to separate them. The same may be found if two boards are placed together with water between them.1 Why does the hand become wet when immersed in water ? Why does it remain dry when drawn out from mercury ? Because, in the first case, the adhesive force between the water and hand is stronger than the cohesive force of the water ; in the other case, the cohesive force of the mercury is stronger than the adhesive force between it and the hand. Thus, when the hand is placed in water, a struggle takes place, as it were, be* tween the adhesive and cohesive force of the water. The hand comes out victorious, for on withdrawing, it carries off a portion of the water. I . Between paper we put mucilage ; between bricks, mortar ; between the pieces of a broken dish, cement. Adhesion takes place between the surface of these bodies and the liquid; cohesion between the parts of the liquid. It is thus that the two surfaces of glass, paper, brick and porcelain are made to adhere to each other. of bodies in contact with each other. Application. — All gilding, painting, whitewashing, cementing, varnishing, gluing, writing, soldering, coating of looking-glasses, plating, &c., &c. Soot adheres to the chimney ; dust to the ceiling; chalk, and fresh paint, to one's dress. the water. Were it not so, the water would not rise, another glass plate near the first and not parallel to it (Pig. 4). Water will rise between them, and the form of its surface will be concave. The nearer the glass plates are brought to each other tlie higher will the water rise between them. This is natural, for the quantity of water between them is in this case very small ; and the cohesive force of the water, therefore, easily overcome by the adhesive force. If a glass tube be immersed (see Pig. 5) the water will rise still higher, because here is a small quantity of water, surrounded on all sides by glass, and the force of adhesion is, therefore, comparatively of greater effect.1 Capillary tubes are tubes so small that nothing thicker than a horse-hair m can pass through them. When such a tube comes in contact with a liquid FI0-6whose cohesive force it overcomes, the liquid is compelled to rise in it. The finer the bore of the tube the higher will the liquid rise in it. In a tube 1-100 of an inch in diameter water will rise over five inches. operating between solid and liquid bodies. Application. — Sponge, blotting paper. Eggs and meat may be kept fresh in sand or pulverized charcoal, these two substances containing capillary tubes which absorb any moisture that would otherwise affect the eggs or the meat. Lampwicks likewise contain capillary tubes ; these support combustion, although there may be but little oil Grease spots in the floor may be removed by laying earth upon them. Our clothes become wet from the rain. In short, everything about us is filled with fine capillary tubes. i. But the reverse of all these phenomena takes place — that is, water is always depressed about glass surfaces, if these are greased. Grease has no attraction for water ; the water, consequently, is left free to obey its cohesive force, and falls below the level of the liquid surrounding the tube. 6. The specific gravity of a substance is it« weight, compared with the weight of a like bulk of some other substance taken as a standard. When we say, mercury has a specific gravity of 13.5, we mean that any bulk of mercury has 13.5 times as much weight as a like bulk of water. 9. The attraction between magnets and iron is called Magnetic Attraction. The attraction which the earth has for magnets, causes the magnetic needle, or any magnet freely suspended, to point north and south. 11. The parts of a body are kept together by their mutual attraction. The attraction between the parts of the same body is called Cohesion. 18. In order to separate a body, its cohesion must first be overcome. If it is difficult to break, we call the body tenacious ; if dim cult to penetrate, we call it hard. often called Capillary Attraction. 15. Gravity, Magnetism, Electricity, Cohesion, and Adhesion, are forces of attraction The last two are called Molecular Forces, because they bind molecules1 together. 16. The first three — Gravity, Magnetism and Electricity— act through great distances ; adhesion and cohesion only at an insensible distance. 17. Instead of magnetic and electric attraction. we may witness magnetic and electric Repulsion, while gravity, cohesion and adhesion, however, exert only attraction. Questions. — What natural force is applied in the balance — the compass — the lightning rod — suspension bridges — blotting paper ? I. "A molecule is the smallest particle of matter into which a body can be divided without losing its identity." Thus, the smallest particles of bread or of salt, which are still bread or salt, respectively, are eules of bread or of salt ago, long before powder was invented, our ancestors used the cross-bow for the purpose of fighting the enemy as well as for the pleasures of the chase, At present, the cross-bow is used only by certain savage tribes, and as a plaything by our children. If you draw the string of the cross-bow, and then let it go again, the arrow placed before the string Hies off with astonishing rapidity. u How is it,'* may we ask, " that a string can obtain such great force ?" If we double a piece of India rubber between two fingers, it straightens again when the pressure is removed. After pressing a steel pen gently against our thumb nail to try its writing qualities, it immediately returns to its former shape. Steel blades and whalebones likewise resume their former shape after having been bent. Steel, ivory, and India-rubber, possess this prop- I. Bodies such as lead, cotton, clay, show very little elasticity. Formerly, it was believed that they had none ; hence they were called inelastic; but even these bodies are not without elasticity ; and it may safely' be asserted that there are no inelastic bodies. Indeed, were it not that all bodies are more or less elastic, it would be difficult for us to live. Were not the ground, the floor, the walls of our houses, the tables and chairs elastic, every contact with them would hurt us. Were not our pa;>er and pens elastic, how long would it not take us to commit our thoughts to paper ! Were not wood elastic, every stroke of wind would blow branches of trees down upon us. erty in a high degree. Such substances are called elastic. Stone, lead, glass and many other bodies possess it to a small extent. Yet glass, when drawn out in tine threads, is so elastic that tissues have been woven from them. 23. EXPERIMENT.— Take an ivory ball ; press it with your hand upon a slab of marble that has been blackened over a lamp. The ball will show a black spot about as large as a pin's head. Now lay the slab on the floor, stand on the table, and let the ball drop upon the slab from a considerable height. The ball will then have a black spot very much larger than before. Although of a hard substance, the ball is flattened to that extent when it strikes the slab, and in resuming its former shape, it rebounds. Familiar Facts.-— An India-rubber ball is flattened still more, and therefore rebounds farther. A soap bubble, striking against the wall, sometimes rebounds. Air, too, is elastic. This may be seen by striking upon a bladder inflated with air. When powder is ignited, gases are developed whose elastic force is so great that it overcomes everything before it. ELASTICITY. 41 tieity, are called brittle Bodies, such as metals, whose parts instead of breaking may assume a different position, are either malleable or ductile.1' The malleability of iron may be seen in sheet iron, and in the plates of gun- boats ; its ductility, in the telegraph wire. Application of Elasticity. — 1. To produce motion : Watch-springs ; springs in watch-cases, boxes, and carriage-lanterns ; the ballista of the ancients ; the cross-bow ; locks, and triggers. 2. To counteract concussion: Wagon-springs; packing glass ware in hay or straw ; springs in mattresses, sofas, chairs and etui-cases. 3. To cause close contact or pressure: Springs in pocket- inkstands: printers' cylinders; some kinds of pen-holders. 4. For weighing : Spring-balances i. Gold is -very- malleable. Gold leaf is hammered out so thin that it takes 300,000 sheets, placed one upon another, to make the thickness of an inch. Platinum is very ductile. 3,000 feet of platinum wire of a certain thickness were found to weigh only about one grain. A single ilk-vrorm thread possesses a thickness equal to that of 140 such fine threads of platinum. Now, as a foot contains 144 lines, and as the tenth part of a line is readily visible to the naked eye, it follows that a single grain of platinum can be drawn out into 4,320,000 parts, each of which is distinctly visible. ELASTICITY OF AIR. 24. EXPERIMENT.— If we immerse an inverted tumbler perpendicularly in water, only a very little of the water will enter the tumbler, and, of course, the air in the tumbler is compressed. If the vessel is pressed down still farther, a little more water enters it, but it will never be entirely tilled with water, because it contains air. A cork previously placed in the tumbler, will show the position of the water-level inside. (See Fig. 6.) Air maintains itsv place like every other body, and presses upon bodies. Its pressure is distinctly felt, and if you withdraw the hand which presses the tumbler down, the tumbler will instantly rise. The air in the glass was compressed, and tended to expand again, because air, like other bodies, is elastic. 2r>. EXPERIMENT.— If a glass funnel be immersed instead of a tumbler, and if inverted with the mouth downward, the upper end being closed with the thumb, the air in the funnel is compressed. As the thumb is removed, however, water rushes into the funnel, forcing out some of the air. 26. EXPERIMENT.— Cement a funnel into the neck of a bottle and pour water into it. Only a small quantity of water will enter, unless the funnel is placed in the bottle loosely, so that there is a passage for the air. For, as the water is poured into the funnel, it forces the air in the tube of the funnel into the bottle. The air in the bottle being thus greatly compressed, its elastic force resists the downward pressure of the water. 27. EXPERIMENT.— Another beautiful illustration of the expansive force of air may be obtained by the " Hero's Fountain." Take a cork which fits into a bottle, and perforate it with a round file. The hole should be made so as to admit with difficulty a glass "nbe, which is now pushed through the cork. The tube should have a very fine opening above. This being done, fill the bottle about half with water and close it with the cork. Then PIQ' ' drive the glass tube farther down, until it nearly reaches the bottom of the bottle. The bottle now contains air in its upper part and water in its lower. On blowing more air into the tube, the air will ascend through the water (Lesson II) and collect in the space above. In so doing, the air over the water is compressed, and in trying to expand, it forces the water upward through the tube. The inventor of this little apparatus was Hero, Christ. Familiar Facts. — The amusing toy, whose harmless missile darts off with such rapidity, the pop-gun, becomes a wonderful object, when we consider the powerful force it serves to illustrate. A piston moves airtight in the tube of the pop-gun. Let it be at one end of the tube ; then insert, air-tight, a stopper into the other end of the tube and commence pushing down the rod ; the air inside is now compressed, it has the tendency to expand again ; but its force is not great enough, as yet, to drive out the stopper. If the rod is pushed in farther, the air is compressed still more, and the stopper is expelled with a loud report Another source of amusement is the blow-pipe. It consists of a long, smooth wooden tube, into which is fitted a sharp nail, around whose head shreds of cotton are tied. This nail is inserted, and by blowing into the tube at the same end, a great quantity of air is forced in, compressing the air inside ; this causes the nail to move forward. On blowing more strongly, the air is compressed more, and its expansive force, therefore, greatly increased. The nail is then expelled from the tube, and its speed will be in proportion to the force with which you have blown into the tube. it, the greater is its expansive force. A useful application of this property of air is the air chamber, used in connection with pumps. (Comp. Less. 77, p. 78.) The Diving-bell may also be considered an application of this force, because it is the expansive force of the compressed air which prevents the water from entering the bell. (Comp. 24 exp.) opposite part. 29. EXPERIMENT.— Immerse a tumbler, horizontally, into a bowl of water, and press it down gradually. It will fill with water, and afterward be entirely below the surface of the liquid. Now turn it to the vertical position, and without, however, raising its mouth above the surface, lift it as high as possible. The whole tumbler is still filled with water, and will remain filled, although the water in two communicating vessels ought to have the same height (Lesson XVIII). The tumbler contains no air, while a large amount of air is over the remaining water, pressing downward upon the water. It is this downward pressure of air which supports the column of water in the tumbler. 30. EXPERIMENT.— Let a vessel be filled with water; then take a narrow glass tube, open at both ends, and immerse it perpendicularly in the vessel. The tube will partly fill with water; if taken out, the water will flow through the tube and fall, because attracted to the earth. Place the tube again in the water, but so that no air remains in it, and take it out again, keeping the upper opening closed with th<j thumb. No water will flow from the tube, because air presses against the lower opening and thus supports the column of water in the tube. On removing the thumb the water will flow out, because, in that case, the air presses as strongly above as it does below; the Familiar Facts. — From an open faucet in a full barrel with its bung-hole closed, the liquid does njt flow, because the air presses against the openi ig in the faucet. To draw vinegar, or any other liquid from a barrel, plunge a long tube into the liquid ; close the upper end with the thumb and withdraw the tube. The liquid in the tube will not flow out (why not ?) as long as the thumb closes the upper end. Oil- cans must be opened on the top in order to obtain a ready flow The instrument before you is a Barometer. It consists of a glass tube with its upper end closed, and its lower end open (terminating in an open bulb). This end of the tube may be straight, or bent in a curve. The frame is not an essential part of the instrument. Inside the glass tube and bulb is mercury. The mercury does not extend quite up to the closed end ; there is a vacant space. Let us examine this space by placing the barometer cautiously in a horizontal position. The mercury will rise to the highest point of the tube. No air could have been in the vacant space; if there had been any, it would not have allowed the liquid to penetrate so far (Lesson X). Let the instrument be put slowly into a vertical position again. The vacant place over the mercury contains no air ; it is called a vacuum. Raise the window, and set the barometer in the open air. Our atmosphere is a great many miles in height. The column of air above the bulb presses upon the mercury ; for air presses in all directions (Lesson XI). The cause of the mercury's standing so high in the open air is the p, Assure of air. The mercury may be in a leather bag, BAROMETER. 49 enclosed in a wooden or metallic case. The pressure of air, like magnetic attraction and attraction of gravity, is strong enough to act through intervening substances. Since the pressure of air is so great as to support a column of mercury about 29 inches high, it is evident that the amount of this pressure is equal to the weight of the column. When the atmospheric pressure decreases, the mercury in the tube falls (why ?); when it increases, the mercury in the tube rises (why ?). Hence the Barometer is used for measuring the pressure of air. Take the barometer back into the* room. You will notice that the mercury stands as high as it did in the open air ; yet the column of air from the ceiling down, which presses on the bulb, is much shorter. The air out-doors is pressed upon by the layers of air above it ; it is compressed, consequently it tends to expand (Lesson X). Now, were the air in the room less compressed, the outer air would rush in, until the air in-doors and that out-doors would be equally compressed. Thus both masses of air exert like pressure ; the pressure of the air out-doors is the same as that of the air in the room ; and we can measure it with the barometer in the room or out of the room. that the atmospheric pressure constantly varies. The reason of this rariation is intimately connected with the temperature of our atmosphere. If we always had the same temperature on our planet, the atmospheric pressure (at the same elevation above the ocean's level) would be the same all over the earth. But let any portion of a column of atmospheric air become warmer than its surrounding parts, then its specific gravity (Less. II.) is diminished; it rises, as warm air always does, and passes away to other regions of the atmosphere. Now, the pressure of this column of air has been diminished because the density (Less. II.) of the column is less than before; and, accordingly, the mercury in the barometer falls. When any portion of a column of air becomes cooler it becomes denser, and its pressure is increased ; the mercury in the barometer then ritet. Winds that are hot, and therefore light, make our atmosphere less dense, and thus cause the barometer to fall. If, as is usually the case, they are charged with moisture, they bring us rain. Colder winds, however, will make our atmosphere denser, and thus cause the barometer to rise. Violent disturbances of the atmosphere, such as storms, cause the mercury to fall suddenly. At present, by means of the electric telegraph, we can anticipate these atmospheric disturbances, and guard against losses to shipping. Hence the use of the barometer as a weather prophet But as our weather depends, also, upon other circumstances, the prophecies of the barometer are not very reliable. The average amount of pressure of air at a temperature of 60 degr. F. is 15 pounds to the square inch. Supposing the surface of an adult to be about 2,000 square inches, the pressure of air continually exerted upon him is about 30,000 pounds. 4. On changing their former shape, bodies may retain their cohesion, and are then said to be either MALLEABLE or DUCTILE ; or they may lose it, and are then said to be BRITTLE. 6. The air about us is constantly pressed upon by the higher strata of air; therefore, it tends to expand continually ; and, being a fluid, it exerts a constant pressure in all directions. cury in the barometer then falls. 10. When the air of our atmosphere becomes denser, its pressure is increased. The mercury in the barometer then rises. INERTIA. 31. EXPERIMENT.— Place a piece of chalk upon a book, and move the book quickly sideways. The chalk drops to the floor without participating in the motion of the book, because the book is withdrawn from under it. Familiar Facts. — A coin laid upon a card on the mouth of a bottle, drops into the bottle if the card is snapped off quickly. It falls, because its support, the card, has been removed from under it. Persons in a 7iorse-car are thrown backward if it starts suddenly. These, and numerous other facts, attest that a body at rest remains at rest until it is set in motion by some force. book, and to the card, was so sudden that there was not sufficient time for it to be communicated to the chalk and coin. Hence it was that these two bodies did not participate in the motion, but dropped, simply because they were left unsupported (Lesson I). Now move the book and the card slowly; the two objects upon them will participate in the motion, and not fall. This shows that for a body to be set in motion, time is necessary. Familiar Facts.— A. person running down hill, a railroad train in motion, can not stop suddenly. Take up your book with the chalk on it, move the book until it strikes against the wall ; the chalk will continue to move after the book has ceased moving. So do persons in a car which stops suddenly. A bell continues to ring for a time after it has been pulled. A boat moves on a little if the action of the oars has just ceased. After stirring the coffee it will revolve in the cup, although the spoon has been removed. A rabbit can not run as fast as a hound ; but if pursued by the hound, he may, by suddenly changing his course to the right or left, gain considerable advantage over the hound, who, not being prepared for the change, must first overcome his inertia before he can turn. From this we see that a body once in motion, remains in motion until stopped by some force or resistance. To stop the motion of a body, time is necessary. Familiar Facts. — If a moving body meet with resistance so sudden as not to have sufficient time to stop, the consequences may be terrible. They are terrible to the body moving, if it can not overcome the resistance. A rider, galloping, whose horse stops suddenly, flies over the horse's head, and is violently thrown to the ground. A frightful disaster is caused when, in its dashing speed, the locomotive of a train k suddenly arrested by an obstacle on the track. A boy who in running strikes his feet against a stone, falls with his face to the ground ; for the upper part of his body continues moving after his feet have been stopped. For the same reason it is dangerous to leap from a train when it is in motion. If the body moving can overcome the resistance, the consequence* will be borne by the resisting body mainly. A stone thrown breakthrough a window. An arrow plunges deep into the side of a horse ; nd a rifle ball whizzing through the air pierces the person against whom it strikes. of trains without a locomotive. The story goes, that once there was a prince of one of the South Sea Islands who, when he first saw himself in a looking-glass, ran round the glass to see who was standing behind it. So we all would like to know the cause of everything. The cause of Inertia lies clearly before us, when we consider that it is the most natural thing for a body to lie perfectly still as long as it is undisturbed ; and, also, that it is quite natural for a body, if once set in motion, to move on forever, if there is no force acting on it so as to disturb that motion. Thus a bullet in a rifle would remain there forever if not acted upon by any disturbing force ; the cause of this state of rest is commonly called the Inertia of the ball, and in former times people thought that the ball possessed a special "property" of Inertia. Now, let the rifle be fired off; the ball will shoot forth, and there is no reason why it should not fly on without stopping, like the earth or the moon, provided there be no disturbing force, THE INCLINED PLANE. 33. EXPERIMENT. — A ball lying on a book upon a table will not fall as long as the book lies in a horizontal position. But let the book be raised on one side, and the ball rolls down. It rolls down the faster the higher the book is raised. The ball presses with its whole weight upon the book ; but when the book is raised a little on one side the ball presses less, and begins to fall. The higher we raise the book the less will the ball press upon the book, and the more rapidly will it descend. The surface of the book, when raised on one side, is an inclined plane. Familiar Facts. — A wagon descending a steep hill need not be drawn by the horses ; it is checked rather, in order to prevent it from rolling down too rapidly. When ascending a hill, the horses have a more difficult task than on a level road. It is tiresome for us to ascend steep stairs. In loading wagons the skid is used, It saves much labor, if it is not placed too steep. If the wagon is very high, the skid must be quite long. The steeper an inclined plane, the greater the velocity of a body descending on it; and the greater the force required to ascend it. FIG. 10. 34. EXPERIMENT. — Let an inclined plane be formed by a board. (See Fig. 10.) Now it makes a great difference whether the ball is rolled down from the middle, or from the space increases through which it descends. 35. EXPERIMENT.— Before the lower end of a grooved board place a ball. Then let another ball be rolled down the inclined plane, so that it strikes the first ball. Mark the place to which the latter moves, and put it in its former position again. Repeat the experiment, having the upper end of the board raised a little higher ; that is, having the inclined plane a little steeper (Fig. 11). The ball rolling down will then cause the first ball to move farther, perhaps to a, and will strike it with greater force. This is owing to the greater steepness of the plane. We have seen that the velocity of a body increases with the inclination of the plane. The last experiment shows that striking force. Familiar Facts — A bullet thrown with the hand inflicts less harm than one lired from a gun. A boy running slowly against a tree scarcely feels the shock ; while by running against it quickly, he might be seriously injured. We throw a marble in the air and catch it again without being hurt, but we should experience pain, if the marble were thrown up very high. Hailstones may strike with force sufficient to break glass, and to destroy standing grain. A boy jumps easily from a fence, but would scarcely dare to jump from the top of a house. The descent of bodies on the inclined plane shows that they are not supported by it with their whole weight; if they were, they would not descend. To say they are not wholly supported means: An inclined plane overcomes a portion of the. weight of bodies upon it. Hence its 3. To overcome cohesion. Our knives, axes, hatchets, scissors, needles, nails, swords, bayonets, saws, files, chisels, planes, plows, &c., &c. THE LEVER. 36. EXPERIMENT. — Balance a rod horizontally on a slate, supported between two heavy books. The rod is in a state of equilibrium, because on each side of the point of support there is an equal amount of matter. Now, place the rod in such a manner that on one side of the support it shall be twice as long as on the other. The longer arm will descend, because it contains more matter. Let us repeat this slowly. Observe, that in lifting the end of the long arm with the hand, it moves through a greater space than is passed through by the end of the short arm. The lengths of the two arms of the lever are in the ratio of 1 to 2 ; and the space passed through by the end of the long arm is twice as great as that passed through by the other. Notice, also, that the ends describe these unequal spaces in the same length of time ; therefore, the end of the long arm of a lever lias greater velocity than the end of the short arm. But it was stated before (Less. XV), that, owing to their great velocity, hailstones, although small bodies, could acquire great power. So will any small weight or object, if it be given great velocity. Apply this to the present case : the short arm of a lever. The greater the length of the other arm, the smaller may be the weight upon it requisite to lift the large weight on the short arm. The weight or pressure to be applied to the long arm for that purpose is called the Power. Thus the small power, with the great velocity of the long arm, counterbalances the large weight with the small velocity of the short arm. A stiff bar made to turn on one point is a lever. The greater the length of one arm of a lever, the less power needs be applied to that arm to lift the load on the other arm. Question. — What power is needed in a lever to counterbalance the load on the short arm ? The amount of power depends, evidently, upon the length of the long arm. If, as in the above case, it has twice the length of the short arm, the power needed to lift and counterbalance the load is onehalf the weight of the load. Thus, if a burden of 100 pounds is to be lifted by means of a lever whose long arm has twice the length of the short arm, a power of 50 pounds is required ; if four times, a power of one-fourth, or 25 pounds. To find the power necessary to lift a load by means of a lever, divide the product of the load into its distance from the point of support by the distance from the point of support to the place where the required. The important points in a lever: 1. The point of support, or Fulcrum. 2. The load (or weight) to be lifted. 3. The power applied. In the lever illustrated above, as well as in the applications given below, the order of these three points is: Load — Fulcrum — Power. Levers arranged in this order are called Levers of the First Class. If, in order to lift a load, a laborer supports his crowbar on a stone upon the ground, and enters the short arm of the lever thus formed under the weight , his lever is one of the first class ; why ? But if he does not use the stone ; if he simply rests his crowbar with one end on the ground, so that the load comes to lie between him and the fulcrum (the ground), then the order of his lever is : Fulcrum — Load — Power ; and this constitutes a Lever of the Second Class. Application. — The nut-cracker; where its limbs are riveted together, is the Fulcrum ; the nut represents the load (in this case the load, or resistance, is to be crushed, not lifted); the power is where the hands are applied. We have here two levers combined. The cTiopping-Tcnife is a lever of the same class. Where the knife is fastened is the Fulcrum. The object to be cut is the Load ; the Power is at the handle (in this case, too, the resistance is not a load to be lifted, but cohesion to be overcome). — Lemon-squeezers ; Cork-squeezers ; the Wheel-barrow ;* the oar of a boat.8 The great progress of our age does not lie so much in the introduction of new forces of nature, of which there are but a few, but in the ingenious application of those few forces, and in their skillful combination into machines. One of the offices of machines is to communicate the effect of a force to bodies which otherwise could not be acted upon by that force. Thus, without the locomotive, the expansive force of steam could not communicate its effect upon a train of cars. The Lever is the simplest of all machines ; and probably, also, the most ancient. By means of a very long arm, it becomes a most powerful instrument. It is told of Archimedes, a Syracusan philosopher (about 250 years before Christ), that he offered to move the earth itself, if the king would give him a place to stand on. THE PENDULUM. 38. EXPERIMENT.— (a.) The string by which a stone is suspended has a vertical direction (Less. I). If the stone is drawn a little to one side, the direction of the string will be slanting. On letting the stone go now, it will begin to move. Since all bodies are drawn to the earth (Less. I), it will approach the earth as near as possible. When nearest the earth, it has again the vertical direction. But the weight does not stop there; its inertia (Less. XIV) carries it onward , being held by the string it does not fall to the ground ; it ascends, until gravity finally stops it. Gravity not only stops it, but also pulls it down again. Noticing its downward course more closely, we see that it descends with increasing velocity. Inertia causes it again to pass by the lowest point of its path ; it ascends on the other side, stops an instant of time, and is then forced back again by gravity. Thus it swings back and forth for a certain time. Each swinging in one direction is called a vibration. The vibrations grow shorter, and observation shows us. that, finally, they cease altogether. If, while the pendulum is vibrating, we beat time, it will be found that the same length of time is necessary for the shorter vibrations toward the close of the experiment as for the earlier longer ones. Thus if the pendulum at first made sixty vibrations a minute, it will continue to make the same number during the same time, although it afterward passes through shorter arcs. same length of time. 39. EXPERIMENT. — (b.) Cut off three-fourths of the string. The pendulum is now shorter than it was before; it has only one-fourth the former length. After it is set to vibrating, count the number of its vibrations during a minute ; the number will be greater than that of the former pendulum. The reason of this is easily seen, if we suspend the shorter and longer pendulum, both, from the same point. The shorter one descends on a shorter, but steeper, incline than the other, and, therefore, takes less time to descend. This shows that a short pendulum vibrates more quickly than a long one.1 I. A pendulum whichjs four times as long as another will need twice as much time to perform one vibration; that is, it will vibrate twice as slowly as the other. Let one pendulum be nine times as long as the other, it will need three times as much time (it will vibrate three times as slowly); or, it will vibrate once while the other vibrates three times. Hence the times of vibrations of pendulums are to each other as the square roots of their lengths. Thus, if one pendulum has a length of 4, and another the length of 36, the former will vibrate faster than the latter ; the square roots being 2 and 6, the latter will require three times as much time as the other to perform one vibration — that is, if it vibrates once every three seconds, the former will vibrate once every one second; or, the longer pendulum will vibrate once in the same length of time that the shorter one vibrates three times. pendulum stops when the clock has " run down ;" that is, when the weight has descended so far that it can descend no farther. The downward tendency of the weight, then, is sufficient to meet that difficulty ; for while the pendulum alone would very soon cease vibrating, the descent of the weight lasts at least 24 hours. (What is meant by winding up a clock ?) But the weight, after commencing to fall, increases in speed (Lesson XV), and as the cord from which it is sus- pended, passes round an axle which causes the hands to move, the accelerated velocity would cause the hands to move faster and faster. To obviate this, the axle is connected with a wheel of saw-shaped teeth (Fig. 12), whidi revolves with it, and above which swings a curved hook, A. A., called an escapement, whose two teeth work alternately in the saw-shaped teeth of the wheel. At every vibration of the pendulum, one of these two teeth stops the revolution of the wheel, and thus interrupts the descent of the weight. Now, since the pendu- into a tumbler, so that it forms a partition dividing the inside of the tumbler into two spaces. The board should not touch the bottom of the glass, but be a little above it. Now pour water into the tumbler, and there will be two horizontal surfaces of water, each having the same height. Remove the board, and in place of it immerse a wide glass tube. The two surfaces of water will again be of the same height. the body of the pot, and if the body were higher than the spout the tea would flow from the spout. Hence, in pouring out tea, we lift the pot and lower the spout 41. EXPERIMENT.— Take a tube made of glass or tin and bend it so that one limb be very short, perhaps, only one- twentieth as long as the other, and let the opening of the short limb be drawn out fine (Fig. 15). Then ponr water into the long tube, holding the short one closed with the finger. On removing the finger, water will jet forth. Thus we have a fountain on a small scale. If the short tube were tall enough, the water would rise until it stood at a level with the water in the other tube. There being no more tube, however, the !jj water rises in a jet, but not to that level, because there is friction, and because the returning drops depress the rising jet. Familiar Facts. — Cisterns, offices, dwelling-houses and factories are supplied with water from large elevated reservoirs. Vessels connected with each other, so that a liquid can pass freely from one into the other, are called Communicating Vessels. 42. EXPERIMENT.— Take a cylindrical tin vessel (about five inches high), with a neck, B, perfectly cylindrical (Fig. 16), into which a cork can be fitted tightly, and with small holes in the sides of the vessel as well as in the upper (tapering) part. These openings are carefully closed with beeswax, the vessel filled with water to the very HYDRAULIC PRESS. 69 edge of B, and the cork set on the neck. If the cork is then driven in by a sudden blow with the hand, the water jets forth from all the openings simultaneously. This will not take place, if the vessel be filled with fine sand. The pressure which we gave to the water in the neck was communicated to the larger body of water in the vessel. The effect of that pressure was great, much greater than the original pressure upon the liquid in the neck ; it was as many times as great as the surface of the water in the neck is contained number of times in the cross- surf ace of the large body of water. The force of a pressure brought to bear upon a small portion of a liquid, is transmitted equally (or undiminished) to all parts of the liquid (in all directions). Supposing, now, the bottom of the tin vessel had merely been telescoped in the vessel. The pressure given to the water in B, would evidently have forced the bottom out; and the bottom would then have exerted a pressure upon any resisting object in its way. Application. — Advantage has been taken of this in a machine called the " Hydraulic Press," invented in 1796 (Fig. 17). By means of a lever (of the second kind) a pressure is exerted upon the water in the narrow tube, A. This pressure is communicated to the water in the wide tube, c, forcing the movable cylinder, J9, to ascend. Bales of cotton, or any other object to be compressed, lying on the plate, and prevented from yielding by the fixed plate, P, are thus compressed with enormous force. For if the surface of the water in the cylinder be 100 times that of the water in the narrow tube, and if the pressure applied to the liquid in the tube amount only to 50 pounds, the pressure exerted upon the bale of cotton will amount to 5,000 pounds But since the power applied by the hand may be increased tenfold with the advantage gained by a longer lever, the amount of pressure may easily be raised to 50,000 pounds It can be farther increased by steam-pressure so that the force of pressure may amount to over a million pounds. 43. EXPERIMENT.— If a glass tube be placed with one end in water, we can cause the water to rise in the tube by sucking it up with the mouth. This is the reason for it : We draw the air which is in the tube, into the mouth ; a vacuum (Lesson XIII) is thus created, and the pressure of the external air* upon the water forces water into the tube. Familiar Facts.— Instead of water we may draw up air alone ; this is done in breathing. We enlarge our lungs and the cavity in our chest (Lesson II, p. 16) ; by this, the air in the chest is rarefied, and the external air, by the pressure of the layers of air above it, forced to rush into the chest. This process is called Inhalation. During the process of Exhalation we contract the chest, and the air must rush out. If we immerse a pail in a pond, and fill it with water, the moment the pail is drawn out again, the water rushes in and occupies the space where the pail was before. In the same way. ^L very useful application of the pressure of air is the Bellows, an instrument for blowing fire. It consists of a space enclosed by two boards opposite each other, which are united around the edges by a wide strip of leather. In front, this spaco opens in a narrow tube. In one of the boards is a hole closed by a valve. A valve is a lid over an opening which admits a fluid into a space, but prevents its return. When the bellows is drawn out, the air inside is rarefied. The external air now seeks to rush in, but it finds no other way than through the valve ; this it opens and instantly fills the extended bellows. When the bellows is drawn in, the air inside is compressed, and its expansive, or elastic, force (Lesaon X) being greatly increased, it presses against the inner sides of the bellows, and, in doing so, closes the valve. There being no other egress, the air passes through the tube in front into the fire. a fixed point 5 When moving, the end of the long arm (where the power is applied) has greater velocity than the end of the short arm where the load is attached. 7. To find the power required to lift a load by means of a lever, divide the product of the load into its distance from the point of support by the distance between the point of support and the place where the power is to be applied. The quotient is the Power. end of a glass tube, as we did in the preceding lesson, let us dip a syringe into water. On drawing up the piston, by means of the piston-rod, the liquid is seen to rise in the COMMON PUMP. 75 suction-pipe ; it is submersed in the water perpendicularly. Inside of the barrel works a piston 0, which fits air-tight, and can be moved up and down by means of the piston rod to which it is attached. It is pierced with a hole, and the hole is covered with a valve, 0, which moves upward. The piston-rod is connected at the top with the lever H When the handle of the pump is drawn out, and has arrived at its highest point, the piston is at its lowest, near the water. If, then, the handle is moved to the left (See Fig. 18), the piston is raised; the valve « is now closed, because the air above it presses down upon it, and because a partial vacuum has been created below the piston. We must now turn our attention to another valve, A^ which is situated between the piston and the surface of the water in the reservoir (in a manner such that the piston, when at its lowest, rests upon it), and which, also, opens upward. When the piston rises, this valve is opened, because the air below it — that is, the air between it and the water— expands in order to fill the vacuum caused by the withdrawal of the piston (Less. XIX, p. 71). The air ascends into the space between the lower valve and the piston, and, accordingly, is now rarefied air But the air below that valve is likewise rarefied, and as such (Less. XIX) it has lost a large portion of its expansive force, and does not press upon the water in P &A much as the air over the water outside of ths suction-pipe, at F F. As a consequence of thia, the water within P is forced to ascend. Then the piston is lowered. The valve A now closes of itu own weight; a portion of air escapes throixgb valve v. On raising the piston-rod the second time, more air is withdrawn from the suctionpipe ; water commences rushing up, and enters through valve A. On lowering the piston a^ain, it descends into the water, and from thia moment all the air below the piston is expelled. Some water is now above the piston, and the lower valve again falls of its own weight. Henceforth, whenever the piston descends, a large quantity of water passes through the piston-valve « / whenever it rises, that quantity of water remains on top of the piston-valve. Afterward, at every rise of the piston, the water above it flows out through the spout. The great principle of the pump is the fact, that the pressure of air upon a body of water, forces the water to rush up into a vacuum that has been formed above the water in a tube communicating with that body of water. A common pump will not raise water higher than about 32 feet. The reason of this is, the air over the water can not exert a greater pressure. In order to elevate it to a greater height, the Forc- 1. The piston of the Forcing Pump is not pierced. 2. In place of the spout there is a tube at the lower part of the barrel, which leads to the place where the water is to be carried. 3. That tube contains a valve, a2, which opens outwardly. When the piston P is raised this valve is closed; thus the air below the piston becomes rarefied, and water is forced through the lower valve t)1, the same as in the common pump. When the piston descends, the lower valve is closed on account of "its own weight; the water above the valve vl is then forced through valve tf into the tube, from, which it can not flow back. (Why not?) Consists of a Herorts Fountain (Lesson X) and of two Forcing Pumps to pump water into it. Two iron levers (called brakes) L and L\ work the iron piston-rods P and P', A wide cylinder, N, stands between the two pumps. It contains water, and a metallic tube which nearly reaches to the bottom and is open at the top This cylinder acts like a "Hero's Fountain," but in the Fire-Engine, and in other pumps, it is called Air-chamber. The tubes of the Forcing Pump enter the air-chamber; each has a valve opening outwardly. When A, one of the pistons -, rises, the valve of tube B is closed by the pressure, which the air over the water in the air-chamber exerts. Water, at the same time, enters from the box through the lower valve C into the barrel of the pump. Why? When the piston E descends, the lower valve D closes of its own weight, and water is forced into the air-chamber through the valve of the tube F. After continued pumping, the water in the air-chamber has risen so high that it has concentrated and compressed the air into a much smaller space. But from Lesson X we see that the more we compress air, the greater its expansive force. Hence it is evident that the jet of water sent forth from the metallic tube is sent forth by the expansive force of the compressed air in the air-chamber. There being two pumps, the jet is continuous. 7. No graduated scale is attached to the pump. 8. The liquid column in the barometer usually stands no higher than 30 inches. The liquid column in the pump stands higher than that in the barometer as many times as its specific gravity is smaller than that of mercury. Let the specific gravity of water be one- thirteenth that of mercury ; then will a common pump raise a column of water 13 X 30 = 390 inch. =32^ feet high ; however, it never does so in reality, for it is impossible to obtain a perfect vacuum in a pump. makes a greater number of vibrations in the same length of time — than a longer one. .3. In Clocks the motory force is the force of Gravity ; in Watches (and in clocks without weights), the motory force is the force of Elasticity. 8. If there is a Fluid between a vacuum and the air, the pressure of air will force the Fluid into the Vacuum. Thus water or mercury rushes into a vacuum formed over a part of its surface, because the pressure of air upon the remaining portion of its surface forces both to do so. (Pumps and Barometer.) 9. A stone on a support, a weight suspended by a cord, are at rest. They may remain at rest during thousands of years. The force of gravity in them is also at rest. But as soon as the support is withdrawn, or the cord lengthened but the hundreth part of an inch, they begin to move. Then the force of gravity in them may be said to do work. That work is called Motion. 10. An elastic spring may be compressed, and may remain so for thousands of years. During this time the force of elasticity in it does no work. But withdraw the pressure, and the spring commences moving. Its motion is the work done by the Force of Elasticity. d . The water in the wide tube of a communicating vessel (if by means of a stop- cock shut-off from the narrow tube) will not flow into the narrow tube (Fig. 14); force the water up (Figs. 18 and 19) , — So long as the force of gravity (in e and / the force of elasticity) does no work. But from the moment that the rope at the top of the incline, to which the body is fastened, is cut; from the moment that the pendulumweight be drawn to one side ; that the long arm of the lever be provided with additional weight ; that the stop-cock in the communicating-tube be opened ;%that the bellows be extended ; that the piston of the pump be moved ; — From that moment Work is done and Motion produced. 13. The effect of the Force of Gravity is Pull. It pulls all bodies to the earth. The effect of the Force of Elasticity is Push (pressure). These effects disappear when work is being done by the forces ; the forces are then converted into Motion. 14. The motion of masses is produced by the work which their forces perform. The mo tions of the human body are work which its leaps over, its passage is followed by a crackling noise, and the passage of lightning through air is followed by thunder. The blow of a whip in the air is also accompanied by a crackling noise ; and a pencil, when it falls upon the table, produces a sound which we hear. So does a stone thrown into the water, a book dropped upon the floor, or the hand rapping at the door. Now, if the whip had not moved through the air, nor the pencil upon the table, nor the stone into the water, nor the book on the floor, nor the hand against the door, no sound would have been produced. between the horizontal joints on the side of a desk, or table ; take the free end of the handle, press it downward as far as convenient, and then let go : a noise will be heard, and the knife will be seen to move up and down very fast until it comes to rest. This is a swinging, vibratory motion, similar to that of the pendulum of a clock. 46. EXPERIMENT.— Let a few drops of water fall into a tumbler filled with water. After first striking the surface, each drop will rise and then fall again. This vibratory motion is communicated to the remaining water. The water shows it in the circular elevations (rings) round the point of contact. Thus the motion of the knife, as well as that of the water, is a vibratory one. Familiar Facts. — A vibratory motion may be heard and felt, when a door is slammed or a gnn fired off. A body is first set to vibrate, then it communicates its own vibrations to the air around it, and the air in turn transmits its vibrations to the ear. In water, the vibrations are rings ; in air, hollow spheres of compressed air, alternating with hollow spheres of rarefied air. No sound is heard if the vibrations are too faint, or too far off to reach the ear ; or if one is deaf. Familiar Facts. — That the sounding-board of a piano vibrates while the instrument is being played, may be seen if a pin or other small bodj be placed on it. Blowing into a pipe sets the air vibrating. In windy weather the church-bells of a city may be heard farther off than usual, at a place which lies in the direction of the wind; while at a place nearer by, but in an opposite direction, they may not be heard at all. If a cannon is fired off at a distance of about 1100 feet, the flash is seen instantaneously, but the report will be heard a second later. At twice that distance, the report will be heard two seconds later. From the time which elapses between the flash of a gun on a vessel in distress, and the hearing of the report on the shore, the distance of the vessel may be found. Thus, if ten seconds have elapsed, the vessel is about 11,000 feet, a little over two miles, distant. The distance of a thunderstorm may be ascertained in a like manner, by counting the seconds that elapse be- ' second. Question.— I What causes the noise when a piece of paper is torn ? 2. "What, when a piece of wood is broken? 3. What, when a whip is cracked ? Bead "Wonders of Acoustics," in Illustrated Library of Wonders. Bead "The Ear," in "Human Body"— Illust. Library of Wonders. ' Bead "Sound- and Echoes" y. 268, in Things not Generally Known,' ;i Water is one of the most necessary elements in human life. By the Hindoos and other pagan nations, it was revered as a Deity; and the masses of bleached bones lying around the few wells in the desert, show that during great heat the want of water may be death to the traveling caravans. Familiar Facts. — Moisture on a slate or on a piece of paper will disappear very soon. Water in a tumbler, exposed to the air, constantly diminishes, until finally none is left. The water in streets, cisterns, ponds, and rivers gradually disappears. When water thus passes off into the air, we say it evaporates. Evaporation takes .place only at the surface of liquids. Familiar Facts. — In summer our breath is invisible; not so in winter, because it cools off immediately after leaving the mouth. In warm weather the vapors rising from rivers, swamps and lakes, are invisible. There may be a great quantity of vapor in the atmosphere, and yet the vapor not be seen. When the air near the earth is cool, the vapor becomes visible, and then we call it Fog. Aqueous vapor (warm, moist air) coming in contact with cool air, forms Fog. The vapor may not be perceived below, but become visible higher up in the atmosphere. This takes place especially when the warm, moist winds (south or southwest winds) come in contact with colder (north or northeast) winds. The vapor then forms clouds. in the upper regions of the air. Familiar Facts — A piece of chalk, a piece of earth, a lump of coal, drop quickly ; but dust, soot and finely powdered chalk, descend very slowly. The minute water-bubbles of which clouds and fog are composed, may float in the air for a length of time. Being filled with air, their specific gravity permits them to do so. Remember that soap-bubbles may do the same. But when aqueous vapor comes in contact with cold air, its bubbles collapse. Then they form drops and descend as rain. On their passage through the air, these drops, small at first, increase in size, because they meet with more aqueous vapor in the air, which condenses upon them. The higher up the clouds, the greater the raindrops. (Why ?) Rain is condensed aqueous vapor. In winter, the aqueous vapor in the atmosphere, instead of condensing, freezes and forms minute crystals These increase in size on their passage through the air, because more of the frozen vapor settles upon them, and reach us as snow-flakes. Snow is frozen aqueous vapor. On stormy summer-days, stones of ice sometimes fall from dense clouds, having an opaque kernel and a transparent rind. They may be disastrous to green-houses and to the crops They are called Hail-stones. But it is not known why, in summer, such cold can be produced as to freeze water, for If ail is, perhaps, frozen rain. Familiar Facts. — Inhabited rooms contain much aqueous vapor. A part of it is exhaled from our lungs. If, in summer, a tumbler is filled with cold water, it becomes cold ; the aqueous vapor in the air around it cools, off, condenses, and forms drops of water all over the glass. Ifr in winter, a cold tumbler is brought into a warm room, the vapor around the glass condenses, and forms, likewise, moisture on the glass. Axes, iron safes and soda-fountains are vulgarly said to " sweat." Moisture is deposited when a person breathes against a window-pane. The aqueous vapor of heated apartments condenses on the cold window-panes and may run down as water. which you have so often admired in the early morning-sun, originate in the same manner. In clear weather, the objects on the ground cool off during the night ; and at the same time the aqueous vapor in the air about them is condensed. Grass and leaves, in general all pointed objects, cool more quickly, hence they have the most dew. If the sky is cloudy, the clouds act like a screen ; they throw the heat back to the earth. Then the objects do not become sufficiently cold and no dew is formed. Sometimes there is no dew, and yet the sky is serene ; this is owing to winds, which bring warmer air to the objects so that they can not cool off sufficiently. As rain is aqueous vapor condensed in the air, so Dew is aqueous vapor condensed on solid bodies. If, during the night, objects cool off to a greater extent, the dew which is formed, freezes. We call it then Frost. frost is frozen dew 47. EXPERIMENT. Familiar Facts.— On a stone pavement, at dusk, sparks may be seen when we are walking, or when a horse is galloping. In these cases, iron (the nails) has forcibly struck against stone. The sparks which we see, are minute particles of iron, or steel, which have been heated to redness by friction. on the floor. It will soon become heated. 49. EXPERIMENT. — Try to ignite a match by rubbing one gently on a piece of smooth glass. It will not burn, because there is insufficient friction; it merely glides over the smooth surface. But if rubbed against a rough surface, such as the floor or a brick, the match presses against the projecting parts of the rough surface and, owing to the friction thus produced, it becomes heated and ignites. Familiar Facts.— Wagon wheels have so much friction at their axles, that unless properly greased, they may be set on fire. He that lets himself down by a rope has his hands blistered. On a cold day, we sometimes rub our hands together. Saws and augurs, after being used, feel hot; a piece of India-rubber, warm. This shows that Friction produces heat. It shows, also, that Motion may be converted into heat ; for friction is motion arrested. Familiar Facts.— "By holding our hands near to a heated stove they become warm. Heat of the stove passes first to those parts of the hands nearest the stove, then it gradually passes to the parts next ; and so on, until all the parts of the hand are heated. 50. EXPERIMENT.— Hold a short wire in the flame of a burning lamp. It will be felt, that even the part of the wire which is not in the flame, is heated; and that the heat increases so that we must soon drop the wire. It is plain that the heat of the flame was imparted first to one end of the wire, and that it was communicated successively to the remaining parts of the wire. This shows that Heat may be communicated by passing successively from any part of a body to the remaining parts. This communication is called Conduction of Heat. Metals are good conductors of heat. Paper, wood, cotton, wool, fur, feathers, ashes, snow, ice, xtraw, and air, are bad conductors of heat. 53 EXPERIMENT. — Place a wire and a piece of wood upon a heated stove, and let them remain there for a while. Both receive the same amount of heat ; yet, if touched with the hand, the wire seems to be the warmer. This is owing to the fact that, being a good conductor, it instantly imparts all its heat to the hand. If you touch a cold iron bar, it instantly takes heat from the hand, and, therefore, seems cold. Application of Conducting Substances. /. Good Conductors. — They conduct heat very rapidly, and, therefore, they are applied in order to diffuse heat quickly. Thus, to boil water and roast meat, iron vessels are used. Iron stoves are heated in very little time. //. Bad Conductors. — They conduct heat very slowly, but they also part with it slowly ; for this reason we apply them to retain heat. They serve to prevent a warm body from cooling off^ and a cold body from becoming heated. Familiar Facts.— If we wish to warm a tumbler on a heated stove, a piece of paper should be placed between the gla.cs and stove; otherwise the glass may crack. In winter, pieces of heated wood are laid in sleighs to keep the feet warm. Boards are placed on pavements, and horsemen like to have wooden stirrups, because wood does not withdraw the warmth from the foot. Cotton quilts, woolen garments, blankets and furs keep the body warm in winter ; they neither allow the warm air surrounding the body to pass off, nor do they permit the cold external air to enter. In cold countries animals have very thick /#r/ some in our latitude have thicker fur in winter than in summer. Northern birds have thick feathers. Feather beds are in favor with persons fond of sleeping very warm. Blast-furnaces are sometimes provided with double walls, and the space between is filled with ashes. A cover of snow retains the heat of the earth ; thus it protects the winter grain from the cold. The Esquimaux build themselves huts of snow and ice. Tender trees, vines and pumps are covered with straw in winter to protect them against the cold. Icehouses are thatched with straw, and their walls filled with saw -dust, to prevent heat from entering. Double windows are used in some houses, becanse the layer of air between them prevents the cold air from entering and the heated air from going out. Bead "Heat," by J. Abbott. Harper & Brother. Bead " Sources of Heat," in The Phenomena and Laws of Heat. Bead " Good and Bad Conductors," in The Phen. and Laws of Heat. Bead " Woolen Clothing," p. 296, in Things not Generally Known. DR A UGH T. 54. EXPERIMENT.— Shreds of cotton, or small strips of paper, held over a heated stove or register, or over a lamp flame, will move upward, and, if let go, they will ascend. The air above the source of heat is heated. From the fact that boiling water runs over, and from a great many othe* facts (Less. XXVII), we know that heat expands bodies, and that heated air is expanded, and thus takes up more space than before, and, therefore, has less specific gravity (Less. II) than it had when cold. Now, as air rises in bubbles through water, so does heated air ascend in currents through the colder air. upright in a cork, and stand the whole on a heated stove or register. Suspend from the top a band of paper, cut in the shape of a spiral , the upward current of hot air will cause it to revolve. 56. EXPERIMENT. — Bring a thermometer near the floor of a room; then, near the ceiling. It will be seen that near the ceiling the air is warmer than below. Heated air rises. 57. EXPERIMENT. — If a window in a heated room be opened above and below, the flame of a burning candle, held in the opening above, will be blown from the room ; if held in the opening below, into the room. Familiar Facts.— The same may be observed with cotton shreds in place of the flame. This shows that the colder air from out-doors rushes into the room from below, while the heated air of the room flows out above. The colder air is confined to the lower parts of a room, because it has greater specific gravity than heated air. Wherever a fire is burning, a current of air, or draught, is produced. A draught is also noticed when passing from the sun into the shade, for where the sun shines, warmer air ascends, and is replaced by the colder air from below. Chimneys serve to increase the draught, because they enclose a tall column of heated air, which has less specific gravity than the outer, colder air. The latter presses in with increased force proportionate to the height of the chimney. If a handkerchief be tied around the small openings under the burner of a lighted lamp, the flame will be extinguished. The same happens, also, if the top of the chimney is covered with a piece of glass ; in this case the draught is stopped because the heated air can not pass out, and consequently no fresh air come in. air ascends and is replaced by colder air. This causes our atmosphere to be in constant motion. The currents thus produced are called Winds. 3. Aqueous vapor, in contact with cool air, forms Fog ; in contact with cold air, Rain; with cold, solid bodies, Dew ; with intensely cold air, Snow. Hail is, perhaps, frozen rain. Frost is frozen dew. partly filled with water, over a flame of a lamp ; the water will be seen to rise as it becomes heated. Warm water takes up a larger space than cold. Familiar Facts.— A. cold tumbler placed on a heated stove will crack at the bottom. The heat expands the glass ; but glass is brittle (what is meant by "brittle?" — Lesson IX), and so the tumbler must break. How may it be prevented from cracking? (Lesson XXY, p. 95.) A bladder, filled with air and tied up at the end, expands if near a hot stove or register. The air inside becomes heated, and heated air takes up a greater space than cold air. A flask with ground glass-stopper is sometimes difficult to open; if it be gently heated around the neck the stopper may be taken out without difficulty. The rails on a railroadtrack are laid so that their ends shall be at a slight distance from each other ; in summer their ends are very nearly together ; in winter they are farther apart. Tires are heated red-hot before they are placed on the wheels, for they are then wider, and, on cooling, fit tight to the wheels. Chestnuts and pop -corn, when exposed to heat, burst open; the heated air inside expanding, forces its way through. Heavy rocks, and the walls of houses, may crack. The reason is this : They expand in summer and contract again in winter. again by cold. Here is an instrument called "Thermometer." The silvery substance in it is one of the few metals which have the liquid state at ordinary temperature ; at an intense degree of cold— such as Arctic explorers experience — it freezes into a solid mass. Its name is Mercury, or Quicksilver If the mercury is heated, it expands, and rises in the tube, simply because it has no other place to which to go. On cooling, it contracts and falls. It may be heated by our atmosphere, that is, by the sun ; or by hot water ; by steam ; by heated oil, or merely by the natural warmth of our hand placed upon it. On examining the thermometer, you notice that it consists of a glass tube with a bulb below. Both tube and bulb are closed. The bulb and a portion of the tube are filled with mercury. Above the mercury is a vacuum. The vacuum is obtained by heating the mercury to a very high degree ; while it then stands very high, the tube is fused at the highest point of the mercury. This closes the tube so that no air can get in. As the source of heat is removed, the mercury falls slowly, leaving a vacuum behind. The frame is not an essential part of the thermometer. A little above the bulb is a point, marked Freezing Point. Everywhere on the earth, ice melts at the same degree of temperature. So, after the tube is sealed and cooled off, it is placed in melting ice. Immediately the mercury sinks, because the cold contracts it. It occupies now a much smaller space, and when it has settled, its lowest point is carefully marked, either on the frame or by etching it on the glass tube. This point is called the " Freezing Point." It has also been found that all over the earth, water, in low countries, boils at the same temperature. So the thermometer is now held upright in the hottest steam issuing from boiling water. Heat expands all bodies ; hence the mercury expands and is seen to rise in the tube. The point to which it ascends is carefully marked ; it is the "Boiling Point" The space between the two points has been divided into degrees. By means of these degrees, we are enabled to indicate the temperature which a body has acquired. after being rubbed a little so as to be perfectly dry, is held to the thermometer-bulb, the mercury will rise to a point which marks the Blood-heat of the human body. It happens to be indicated on our thermometers by the number 97. This is owing to the fact, that in our country, and also in England, the space between the freezing and the boiling points is measured by very small degrees, of which there are 180 between those two points. Fahrenheit, a philosophical instrument maker, divided that space into 180 degrees. He commenced counting, however, not at the Freezingpoint, but at a point below, which is the zero point. The freezing-point thus happens to be at 32°; this causes the boiling-point to be marked 212°. On the continent of Europe, the Freezingpoint is marked 0°; the Boiling-point 80°. That is, the space between the two points is divided into only 80 degrees. Each degree of this kind is much larger (how many times as large ?) than one of the former kind, the Fahrenheit. From the name of the French philosopher who arranged this scale, its degrees are called degrees Reau mur. Thus 80° R. is equivalent to 180° F. Far more convenient than either of the two preceding scales is the one of Celsius. He divided the space between the freezing and the boiling points into 100 degrees. The use of this division is gradually spreading. According to it, 100° C=18QCF=8QG R. The healthiest temperature for any room ie about 65° F. Our rooms should not be heated beyond that in winter. Thermometers should be placed at equal distance from stove, or fireplace, and the windows, so as to show the mean temperature of the air. Questions. — If in New York the mercury stands at 80° above zero, how would the same temperature be indicated in Paris (according to C. degrees)? How in Berlin (according to R. degrees) ? By what numbers would the blood-heat point be indicated according to those scales ? By what number is the point of healthiest temperature indicated in C. and R. degrees ? 8. The thermometer haa a scale of degrees whose -size is arbitrary and may be different in different thermometers ; the barometer has a scale of inches, and fractions of inches ; its scale is of less extent, and only at the upper part of the tube. 4. Mercurial Thermometers may have any THE ATMOSPHERIC ENGINE. 1. If we look at a sewing-machine while it is in motion, our attention is immediately called to a long, upright rod, made to move up and down by the stroke of the foot. The rod being fastened to a wheel, it is evidently its up and down motion that causes the motion of the wheel and with it, that of the machine. You need but fasten a rod to the edge of a toy- wheel, and you may demonstrate the same. Motion in a straight line — rectilinear motion — is thus converted into circular motion. 2. This was known thousands of years ago; but, strange to say, the principle upon which the steam-engine is founded, was not thought of until about 1690, A. D. At that time, Professor Papin, an exiled Frenchman living in Germany, published a little work, in which he says : " There is a property peculiar to water, owing to which a small quantity of that liquid, if heated and converted into steam, acquires a force of elasticity which much resembles that of air. When cooled down, it returns to the liquid state, and loses its elasticity, I am, therefore, inclined to believe 3. These words laid the foundation for the greatest change which human society ever experienced. The machine that effected this change has benefited humanity more than all the gold mines in the world. The steam-engine not only reveals to us the hidden treasures of the earth ; " it can engrave a seal ; crush masses of obdurate metal like wax before it; draw out, without breaking, a thread as fine as a gossamer, and lift a ship of war like a bauble in the air. It can embroider muslin and forge anchors ; cut steel into ribands and impel loaded vessels against the fury of the winds and waves." And when it flies with the rapidity of a bird, over land and water, hurling dense masses of steam and smoke into the air, does it not look like some gigantic monster that contains the strength and the power of thousands of men ? Well may we admire the genius of man that can turn one of Nature's simplest forces to such wonderful account. 4. The simplicity of Papin's statement is demonstrated by his own application. Knowing that steam was elastic like air (Lesson X), he immediately proceeded to the construction of an apparatus which, although its practical usefulness was impeded by its slowness, was the first steamengine ever built. 60. EXPERIMENT.— Papin's apparatus may be illustrated by a test- tube (one of tin is preferable inasmuch as glass breaks easily,) as shown in Fig. 22. A small disk of wood, with a packing of thread around it to make it fit tight, is made into a piston, P, moving in a tube nearly air-tight, and attached to a rod. The tube is then filled with water about an inch high, which is made to boil over a flame after the piston is carefully placed in the tube. The generation of steam causes the piston to rise. The steam escapes FIG. ». through a small hole, E, made in the upper part of the tube. Between the water, when boiling, and the piston there is no air ; the space is filled with steam. On immersing the tube in cold water, the rod descends again, because the steam below the piston is condensed by the cold, and because a vacuum is thus formed between the piston and the surface of the heated water. What is it that forced the piston down ? The answer is : " Atmospheric Pressure." (Lesson XI.) 5. In place of the small tube of this experiment, Papin used a large iron cylinder, with proper piston and piston-rod. We can readily imagine how, by throwing, at regular intervals, a stream of cold water on the cylinder, he produced an up-and-down motion of the rod ; and how his machine must needs have been slow — too slow to be practically applied. A steam-engine built upon the principle of Papin's — that is, one not worked by the expansive force of steam, but merely by atmospheric pressure — is not a steam-engine. It is an " Atmospheric Engine." 6. Captain Savery, an Englishman, constructed at about the same time, an apparatus in which the steam served the purpose of raising water. The steam was generated in a separate boiler, and thence led into a chamber where it was condensed by cold water flowing over the chamber. The apparatus, however, was very imperfect, and used only for pumping water. Still, his was the merit of having constructed the first Atmospheric Steam -Engine that received practical application. 7. Thomas Newcomen, a hardware man, and John Cowley, a glazier, both Englishmen, by their brilliant invention, completely eclipsed Savery's engine. They improved upon Papin's plan in this, that they generated the steam in a boiler — not in the cylinder — and that they condensed it, not by cooling the boiler from without, but by forcing a jet of cold water into the steam. The machine was put to immediate use in the coal-mines of England; and it is sometimes used even at present, in places where a great mass of water is to be pumped out. Its construction is very simple. PIG. 23. connected with the boiler by means of the pipe, F. When steam has entered the cylinder and the piston, #, is raised, the stop-cock, a, is closed. This shuts off the connection between the boiler and the cylinder. The stop-cock, 6, is then opened, and a jet of cold water from the small reservoir, (7, is thrown into the cylinder. This condenses the steam in the cylinder ; a vacuum is formed below the piston, and atmospheric pressure forces the piston down. The water from the condensed steam flows off through the pipe, d, into a reservoir with water. (At the end of d is a valve opening outward.) By means of an iron chain, the piston-rod, H, is attached to a working-beam, which swings on the pivot, J9, and which is connected at the other end with the rod E. This rod is raised when the piston descends. When the stop-cock, a, is opened again, the steam rushes again into the cylinder ; but as the force of pressure of the steam scarcely exceeds that of the air over the piston, the piston would not rise, were it not for the heavy weight attached to the rod, E. This weight falls whenever steam is let in under the piston, Q; and in falling, forces one arm of the working- beam down, causing, at the same time, the piston at the other arm to rise. The rod P is the pistonrod of a pump, and is fastened to the weight. 1. Half a century had passed away. Newcouien's engine had been introduced into most of the coal-mines of England, when, in the winter of 1763, a young mechanic, James Watt, in Glasgow, was employed by the University of that city to repair one of Newcomen's engines, The task which this man of uncommon mind was about to undertake, marks a new era in the history of steam-power, an era that finally resulted in the perfection of a machine which is an element of modern civilization. On trying the engine after he had repaired it, young Watt perceived that it was very imperfect. The principal defect consisted in this, that the machine used a great deal more steam than was needed for the motion of the piston. For when the stream of cold water was thrown into the cylinder, the steam was condensed ; but at the same time, the cylinder was cooled down to such an extent, that when fresh steam was admitted again, a great quantity of it was wasted in reheating the cylinder ; and thus there was a loss of money in direct proportion to the amount of fuel necessary for producing the quantity of steam equivalent to the quantity wasted. On calculating the loss, it was found that I of all the fuel used was wasted ; that is, employed in reheating the cylinder. The question with Watt now was, How can the cylinder, instead of being cooled, be kept permanently hot ? In other words, How can the steam be condensed without at the same time cooling the cylinder ? 2. Watt's genius solved the problem by an invention of surprising simplicity. He condensed the steam in a separate chamber, the condenser. It stood in a chest filled with water, and was connected with the cylinder by means of a pipe. Thus the steam could be condensed without cooling the cylinder, by simply leading it off. The immediate result was the saving of I of the fuel. 3. But Watt did not stop here. He noticed that the air entering the heated cylinder as the piston went down, also cooled the cylinder. This caused a waste of steam, as the cylinder, in order not to condense the fresh steam entering, had first to be reheated to 212°. To remedy this, he dispensed with the air entirely, in providing the cylinder with a cover pierced in the center so as to admit the piston-rod air-tight. The air (atmospheric pressure) could now no longer act upon the piston ; how then was the piston to descend? It was made to descend by allowing steam from the boiler to enter above the piston, through a pipe connecting the boiler with the upper part of the cylinder ; and to pass out again through a pipe connecting the cylinder with the condenser. Thus while there was a vacuum established in the lower part of the piston, steam was admitted into the upper part ; the upper part then being made a vacuum by leading the steam off into the condenser, fresh steam was admitted into the lower part and forced the piston up. By this improvement, the steam not only served as a ready means for obtaining a vacuum, as in Newcomen's engine, but its expansive force was also made use of, and from that time Watt's engine was no longer an atmospheric, but a steam-engine. 4, The atmospheric engine was "Single Acting ; " it did work only while the piston descended ; the rise of the piston, as we remember from the preceding lesson, was effected by gravity. The power obtained by this machine was so small that it could not overcome the resistance of a wheel, and, therefore, it was used mainly for pumping water out of coal -mines. 5. It will now be readily understood, that by admitting the steam alternately above and below the piston, Watt made the steam-engine "Double Acting," and this was, perhaps, the most impor tant of all his improvements. For now, circular motion could be produced, without which no locomotive or steamboat could ever have been Watt died in 1819, honored and admired by all who knew him. Within a short time after his death, five large statues were erected to his memory. 6. In all the engines constructed by Watt, the power of the steam was low ; it amounted scarcely to more than li atmospheres (li as much as the pressure of our atmosphere ; that is li times 15 pounds to the square inch of surface). The alternate condensation of steam on either side of the yiston was, therefore, the only means of obtaining the up-and-down motion of the piston; for the feeble expansive force of the steam was totally insufficient to overcome the counter- pressure of the atmosphere. But by employing steam of greater expansive force — that is, steam capable of exerting a higher pressure — one might dispense with the condenser. It was reserved to an American, Oliver Evans, in Philadelphia, to introduce steam of a higher pressure as motive power. Engines usually having a steam-pressure of from 3 to 15 atmospheres (45 to 225 pounds of pressure to the square inch), are called High Pressure Engines; those working with a lower pressure, Low Pressure Engines. Cylinder. It is enclosed in a square box, called the steamchest (See Fig. 24), which is attached to one side of the cylinder. When the steam from the boiler reaches the steam-chest through the opening, o, it fills the chest at once, and, as the sliding-valve keeps the opening, 5, closed, it presses through the opening a into the cylinder. There it fills the upper part and forces the piston down. This it does because a vacuum has been formed on the other side of the piston, or, as is the case in High Pressure Engines (see Fig. above), by the immense expansive force of the steam. At the same time, however, the sliding-valve (which rises when the piston-rod descends, and descends when the pis- now enter through the opening b and force the piston up. Meanwhile the old steam above the piston passes through a and e into a tube leading to the condenser. In a steam-engine which has no condenser, as, for example, the locomotive, the old steam passes through e into the air. After the piston has arrived above, the process is renewed, owing to the sliding-valve having a motion opposite to that of the piston ; thus steam is admitted alternately above and below the piston which, as every one knows, movee in a vacuum, or rather, in a space filled with steam. Steam-engines with steam of very high pressure usually have no condensing apparatus. 8. When we look at a locomotive rushing past us at full speed, we notice a horizontal iron rod moving back and forth. The rod connects two large wheels, and runs at one end in a wide brass cylinder. Next to this cylinder is the steam-chest, a small square box. It is in the cylinder that the motory power is imparted to the engine. In addition to these things, we see a great many wheels, pipes and rods; but they mostly serve minor purposes. The main parts of the locomotive are the steam-chest, cylinder, piston, pistonrod, the large wheels, and the boiler. 9. The steam, by means of the sliding- valve, causes the back-and-forth motion of the piston in the cylinder ; by this, it causes the back-and-forth motion of the piston-rod ; and by this, the revolution of the large wheels. The wheels roll on the track ; they cause the locomotive to move onward, and the locomotive pulls the cars attached to it. 1. The motion of a body produces vibrations in the air which, it1 they impress the ear, give us the sensation of sound. Sound, therefore, is merely the effect of a vibrating motion upon our ear. motion among the minute invisible parts (molecules) of a heated body. We can not see that vibrating motion, but we can feel it. a sliding- valve) the back-and-forth motion of the piston in the cylinder ; and by this motion, the back-and-forth motion of the pistonrod ; and by this, the revolution of the large wheels. The wheels roll on the track ; this causes the locomotive to move onward and draw the cars attached to it. 11. On dropping a stone to the floor, the floor and the air over the floor, commence vibrating. • This shows that Force (Force of Gravity in this case) may be converted into Motion. as expansion (the work done by heat) ia motion, we may say that Heat is also convertible into Motion. (Thermometer.) pands still farther. The particles of steam, therefore, are in continual motion. The effect of this motion is the Expansive Force of Steam. This shows that Motion is convertible into Force. (Compare Less XXII, Review.) 15. The Expansive Force disappears as soon as the steam has moved the piston of the engine. The motion of the piston is the work done by the steam. Thus, in this case, Force is converted into Motion. (Compare No. 14, above, and Less. XXII, No. 13.) 16. Force of Pressure is convertible into Motion of Masses. (Wind— Barometer— Pumpa.) 17 From all the preceding, we see that a. Force is convertible into Motion. (The Familiar Facts.— While the sun shines— that is, during the day — it is light; we can see objects at a distance. But we can not see objects at night, for then it is dark ; the sun is on the other side of the earth. The light of the stars, or flashes of lightning, may somewhat relieve the darkness of night ; glow-worms may feebly illuminate our immediate vicinity. If we rub a match in the dark against the hand, the phosphorus will shine on the hand. This property is called Phosphorescence. Glimmers of light are also noticeable in decaying animal and vegetable substances. Two pieces of sugar, after being rubbed together, also emit light. Candles, oil and gas, at times, also, torch-lights, are our usual means of illumination. But our greatest luminary is the sun. 1. The Sun and the Fixed Stars, Electricity ', Phosphorescence and Burning Substances are Sources of Light. The sun, stars, lightning, phosphorus, glow-worm and flame are Self-luminous Bodies. she receives it from the sun, the same as the other planets do. She is invisible to us, except when the sun's light falls upon her. When the room is dark, a book upon the table can not be seen; neither can the table, nor the desks, nor the streets, nor anything else. None of these objects is selfluminous; that is, in order to be seen, these objects need light from a self-luminous body. not see. Nor can persons who were born blind, or have become blind from accident or disease. In order to see objects behind us, we must turn around ; to see things above us, we must turn our eyes upward. 3. Bodies not self-luminous are visible only when they receive light from a self-luminous 'body; and then only, if a part of that light forms an impression on our eye. Pencils, crayons, glass, water, ice, trees, houses, .and all other objects are seen by us, because when light falls upon objects, a portion of the light is diffused from their surface in all directions, and because a small portion of that diffused light enters our eye and forms an impression on the retina. From our room we see objects out-doors very clearly; but when looking from without, objects in the ibom are not seen so well. The amount of light diffused in a room is much smaller than that diffused out-doors. — It is light in daytime, although it may be rery cloudy. The clouds receive all the light from the sun, and diffuse a portion of it. (with a small hole in it) a few inches from the blackboard. A bright spot will be seen on the blackboard. It is a spot illumined by the rays of the light that pass from the flame through the opening. The direction from the flame through the hole to the illumined spot is that of a straight line. Let the flame be moved about, the spot will move also. Familiar Facts.— Through the cracks in the shutter of a darkened room, rays of light are observed to enter in straight lines. The hunter levels his gun at a squirrel in the direction in which the rays of light diffused from the squirrel enter his eye. Opera-glasses and telescopes have straight tubes. RADIANT AND SPECULAR REFLECTION. During the daytime, sunlight is diffused in the atmosphere as well as in the air of our rooms, whether the sun is visible or not. Some of this light in the air falls upon the walls and upon the objects in the room ; and the walls, as well as the objects, reflect (throw back) that light in all directions. They reflect it thus: Every point of their surface radiates the light in all directions ; hence any point of this surface may be seen by a person in the room, whatever part of the room he may be in, provided that a portion of that reflected light strikes his eye. Familiar Facts.— Here is a pencil. What enables us to see it? It is not a self-luminous body ; but there is diffused light in the room, and as the pencil has a more or less rough surface, every point on that surface receives some of this diffused light, and in turn reflects some of it. It does so by radiating the light in all directions. Of this radiated light, a portion enters our eye, and we say " we see the pencil," and may then describe it. LIGHT, CONTINUED. is smoother than that of the pencil, or of most objects; yet even in a looking-glass there are very many uneven places, from every point of which light is reflected by radiation. Were it not for that, we would not see the glass at all. The surface of a perfect mirror is invisible. thrown upon the floor in the direction in which a ray of light would pass through a crack on the floor of a darkened room, the ball will rebound, and may be made to strike the wall opposite the craok. Let the place where it strikes the wall be marked. Now lay a looking-glass upon the bright spot on the floor of the darkened room (the spot is caused by the rays of light entering through the crack), and it will be seen that the rays, like the India-rubber ball, rebound to where the ball struck the wall. Evidently the rays are reflected by the looking-glass. Any other highly polished surface would have caused the same reflection. All this shows that there are objects which not only reflect light by Radiant Reflection in all directions, but which, in addition, reflect an extra amount of light in certain definite directions. We call this Specular (mirror-like) Reflection of Light. Familiar Facts.— Burnished metal plates, polished wood, the surface of water or mercury, the coating of mercury in looking-glasses, and even common glass plates when viewed in a very oblique position, exert both, "Radiant" and "Specular" reflection of light. Objects with polished surface reflect light radiantly and specularly. Familiar Facts.— I. When a person is hit with a stone he does not seek the person who threw the stone, in the direction in which the stone flies, but in the direction from which it comes. Thus, he whose forehead has been struck by a stone in a downward direction, looks upward for the perpetrator ; he supposes him to be in the direction from which the stone came. If struck by a stone in an upward direction, he will look downward to find the evil-doer. Since light travels in straight lines (Lesson XXXII), the ray crosses the lower part of his eye in a downward direction. The lowest ray coming from the foot of the steeple would, if extended, traverse the upper part of his eye in upward direction. But if, turning round and then bending his head down to his knees, he looks at the steeple from between his knees (Pig 27), th« F16. T Image Cprifkt. topmost ray will, if extended, pass downward through the upper part of his eye ; and the lowest ray, upward through the lower part of his eye. In this case he would see the steeple inverted, were it not for the fact that the eye sees an object, or any part of an object, in the direction from which the rays of the object come. All bodies appear to be situated in the direction from which their ray* enter the eye. 63. EXPERIMENT.— Immerse a pencil in water perpendicularly; it looks as straight as before. But when immersed obliquely, it appears bent, or broken. Oars, when partly immersed, present the same appearance. When the pencil is out of the water, we see it by means of the light diffused from it (Lesson XXXIII). Consequently, when the pencil is partly immersed, we see the portion above the liquid for the same reason. The light diffused from the immersed portion, however, must first travel through the water, and then through the air. Now, since the immersed portion seems to be bent, it follows that the rays diffused from it are bent; that is, they travel in straight lines through the liquid, but on entering the air, they are made to deviate from their straight course. But the eye is in the habit of following the direction of the rays, and must see the pencil bent simply because the rays coming from it are bent. Let a b be the pencil partly immersed ; the part immersed, a c, appears to be at d c, because the ray coming from a, which ought to pass out in the direction of a 6, is made to deviate from its course when leaving the water at c, and enters the eye in the direction of d e. The eye, believing the point a to Fio.28. be in the direction from which its ray comes, sees the point a actually as being at d. The same takes place with the other rays entering the eye ; hence the whole part a c is seen as being at dc. 64. EXPERIMENT. — A coin placed on the bottom of a filled tumbler, is seen in its true direction if viewed perpendicularly; but if viewed obliquely, it will be seen in a more elevated place. the bottom of clear waters appears to be more elevated than it really is ; that is, water often appears less deep than it in reality is. This must be taken into account by persons bathing, so that they may not go beyond their depth. Rays of light, on passing obliquely through substances of different densities (such as air and water, or glass and water), deviate from their straight course; they are bent. This deviation is called Refraction of Light. then be seen as being above its true place. The reason is this : Rays of light, a e — we take but two for the sake of simplicity — diffused from the arrow, strike the surface, b c, obliquely, and are, therefore, refracted to / (Less. XXXIV). On passing from the glass prism at /", they are again refracted, and enter the eye which is stationed at g. But the eye follows the direction of the refracted prism inverted (Fig. 31); that is, placed so as to present two edges upward. The arrow will then be seen below its true place. The reason of this is the same as before. The rays a e are refracted to// consequently the arrow is seen as being at A:. If now we place two prisms together, as in Fig. 32, rays diffused from the arrow and entering points behind the prism. In order that the eye of a person situated at /, might receive all these refracted rays, and thus be able to see the whole arrow through the prisms, it would be necessary to have these rays blend into a common point. To do this, we must have the surface, a b c, curved (Fig. 33) ; that is, we must have a curved glass in place of the prisms. For it not only brings rays of light to a common point, the Focus, but at the same time it blends rays of heat into a focus. In consequence of this, a match ignites, and a hole is burnt in a piece of paper, if either of these objects be held in the focus. taking the two extreme rays for the sake of illustration— the rays, d e and f g, refracted to the eye, are seen as coming from the points h i. (Why? Lesson XXXIV, p, 130.) The common Burning glass, therefore, is also called Magnifying- Glass. COLOR. 66. EXPERIMENT.— If a large pasteboard with a small hole be placed facing the sun ; or if a room be darkened and only a few rays of light admitted through a crack in the shutter, these rays will pass to the floor and there form a spot of white light. But if a prism1 be held before the crack or before the hole in the pasteboard, the rays of light will be refracted (Less. XXXIV), and spread out in the form of a long band. Instead of being white, this band will be colored. The colors of the rainbow may be distinguished in it ; viz. : Violet, indigo, blue, green, yellow, orange and red. The colored band is called the Solar Spectrum ; and this spreading out of light 1. A prism which is to show the refraction of light, may be of solid glass, or, if such a one can not be had, it may be constructed in the following manner : Procure two strips of common glass, having the shape of a rectangle, each of the same size, about 5 inches long by ij£ inches wide. FIG. 35 One of the long edges of each is heated over an alcohol flame; both edges are then cemented together with sealing-wax, allowing a distance of i^ inches between the two remaining long edges. The ends of the vessel thus formed are closed by triangular pieces of thin board, measuring \}/z inches on each side, and which are likewise cemented to the glass. Water is then put in, and when used, the prism is held so as to have the long cemented edge below. lines like ordinary light. 67. EXPERIMENT — To convince ourselves that ordinary sunlight contains the seven colors of the rainbow, let the spectrum produced by one produced white light again. 68 EXPERIMENT. — The same may be shown if a top, painted with the seven colors of the rainbow, is set spinning rapidly. The impressions made in the eye by these different colors are mixed together, and thus produce a mixture of the colors which is nearly white. of the seven colors of the rainbow. 69. EXPERIMENT.— The spectrum will then be almost entirely red, and the other colors be found wanting Insert a piece of green glass in place of the red ; the spectrum will be almost exclusively green ; with blue glass it will be nearly blue, &c. It is manifest, that white light falls upon each piece of colored glass ; and that only one color at a time falls upon the prism. Thus when the red glass is inserted, only red light falls upon the prism, and consequently there can be but a spectrum of red light. The question now is, what becomes of the remaining light — or colors — which fall on the red glass ? Evidently the red glass absorbs all the light except the red, and this it throws out. The same takes place with each of the other colored glasses ; the green absorbs all the light it receives except the green light ; this it throws out. The blue absorbs all the light it receives save the blue, which it throws out, &c. White glass, however, transmits nearly all the light, and absorbs very little or scarcely any. 70. EXPERIMENT. — If a sheet of red colored paper be held facing the sun, and a sheet of white paper before ^it, so as to form an oblique angle with it, the portion of the white paper which is near the red, will appear red. In this case red rays are diffused from the red body and fall upon the white. But the red paper receives white light from the sun, hence it must have absorbed all of the white light save the red ; this it throws out. Familiar Facts. — Objects near a blue curtain often have a bluish hue. The curtain receives white light, and absorbs it all except the blue, which it reflects. Objects near the foliage of trees and bushes often have a greenish hue, because green leaves absorb all the light that falls upon them save the green ; this they diffuse in all directions, and thus send green light to the objects near by. A body is colored when it reflects only a portion of white light. A body is white when it reflects all the white light; and a body is black when it reflects (almost) no light, that is, when it absorbs all the light. Questions. — What causes a piece of red cloth to appear red? It sends only red rays to the eye, the other rays it absorbs. What causes a sheet of white paper to appear white ? It absorbs no light, but rejects nearly all of it. Some of this rejected or reflected light enters the eye and thus produces the sensation of white in us. What causes a black coat to be black ? It absorbs nearly all the light, consequently it sends scarcely any to the eye. The eye receives just enough light from it to become aware of its presence, but not sufficient to perceive any color. Why is every thing black in a dark night? Because, when there is no light, objects receive none, and, therefore, they can not send any to the eye. But if no light enters the eye, we see nothing (Lesson XXXHI). Application. — The application of colors is so manifold, that it is impossible to mention each. They serve to enliven the scenery aronnd us , to improve our own appearance , to indicate joy or mourning. We imitate the thousand delicate hues and tinges of the colors in nature in our paintings, artificial flowers, and in many different contrivances Colors also serve as signals to be seen from afar; hence their use in lighthouses, on railroads (colored lights), and with the military (flags), &c., &c. 71. EXPERIMENT. — Take a plain glass tumbler, and place in it a porous cup of earthenware (unglazed) in a manner such, that between the cup and the tumbler there is a finger's width of space left. Next have a small sheet of zinc cut as high as the cup. Then bend it into a cylinder wide enough to encircle the porous cup freely. This cylinder is open above and below, with a slit through its whole height. On the top, and opposite the slit, about a square inch of zinc is left higher than the rest. To this piece, one end of a copper wire about a foot long is soldered. The zinc cylinder is put into the space between the tumbler and the cup ; the space is then filled with diluted sulphuric acid (a table-spoon full of the acid mixed with ten times the quantity of water). The cup is filled with strong nitric acid. In the acid place a plate of carbon, to the top of which the end of another copper wire is soldered. If no carbon plate can be had, a narrow strip of platinum may be used, and another wire soldered on it. If that, too, can not be obtained, fill the cup with crushed coke.1 Thus prepared, the cup is CHEMICAL ELECTRICITY. 141 placed inside the zinc cylinder ; the diluted acid, of course, surrounding it. Such an apparatus is called a cell or element ; if two or more cells are connected with each other, the apparatus is called a battery. The free end of the wires must be scraped clean with a file or knife. If, then, they are brought quite near to each other, a small, bright spark is produced. If the tongue is held between the two ends, a thrilling sensation is felt— /J JK£ , In the first place, the diluted acid acts upon the zinc; this action may be seen by the minute bubbles rising from the zinc; it may also be heard. They are bubbles of a gas called hydrogen. In the second place, we have carbon, or platinum, in contact with nitric acid; the action which takes place here is invisible. Thirdly, the two liquids penetrate the porous cup, and, therefore, meet with each other. This action is invisible also. The mutual contact of two different metals (or of zinc and carbon), each* placed in a certain liquid, produces Chemical Electricity. and a little nitric acid mixed with it, so that the powder may be soaked with acid. On top of the coke a lump of coke is placed, around which a copper wire is wound several times, so that about a foot length of wire remains free. That the coke lump may stand firmly, surround the lower part of it by coke powder. century. The electric spark is seen only when the free ends of the wires are brought together. The zinc is in contact with the diluted acid; electricity passes from the zinc to the acids, and thence to the carbon, and from the carbon, electricity, that is the invisible electric current, passes along the copper wire, returns to the zinc, then to the diluted acid again, and so forth, in the same manner as above, forming an uninterrupted current of Electricity. If the metals (wires) are not very near to each other, no spark is seen, and the current is interrupted. If the end of one of the wires be attached to a pair of scissors, the spark will be seen at the point of the scissors on bringing it very near to the other wire. Nor would it make any difference if the wires had greater lengthy Next to the steam-engine the telegraph forms the wonder of our age. Its eminent usefulness and, more yet, the incredible rapidity with which it communicates messages from one place to an other, is something so new, so extraordinary, that we are tempted to believe there is nothing which the human mind is not capable of penetrating. The fire-signals of the ancients were no longer sufficient for the increasing demands of civilization. Toward the end of the last century, so-called u optical" telegraphs, consisting of high poles erected upon high buildings or hills were used in France. By means of moveable arms attached to them, signs could be made which in clear weather were visible at great distances. But when, in 1820, it had been discovered by Oerstedt, a Danish professor, that the electric current running along a wire, exerted a certain influence upon iron, it was at once proposed to apply that influence to the telegraph. The first electric wire by which messages were sent, was put up by Steinheil, between his place of residence in Munich and the astronomical observatory near that city. England soon fol- lowed the example ; so did America. As is always the case with new inventions, a great many improvements were made in rapid succession. It was an American, Morse, who, by a very simple but ingenious improvement, brought the telegraph to its present degree of perfection. illustrated easily by the following experiment : 72 EXPERIMENT. — A cylindrical rod of soft iron is bent into the shape of a horse- shoe. The rod may be J inch in diameter and 10 inches long. Its two ends must be filed smooth ; the whole is then covered with clay and placed in a coal fire. There it is left for a time and allowed to cool gradually, until the fire has gone out. After this the clay is removed, and the two ends filed smooth again. Then take a coil of copper wire of about -52 of an inch diameter, heat it red hot and cool it in water. Silk ribbon is then wound around it (old silk rags sewed together and cut into strips, will serve the purpose very well), in a manner such that the ribbon, about \ inch in width, shall completely envelop it. The wire thus covered, is wrapped round the iron in close windings. (See Fig. 37.) When beginning to wrap, leave about two feet of wire free, wind then closely near to the bend ; leave the bend uncovered, and stretch the wire across to the other arm. Then proceed downward to the other end, and leave the last two feet of the wire again free. Both ends of the wire are to be scraped clean, and afterward connected with the wires of the galvanic element, so that the wire starting from the carbon (or platinum) be connected with one of the wires of the horse-shoe ; and the wire of the zinc cylinder, with the other wire of the same.1 If now a piece of soft iron, smooth on one side, or a nail, be held at a small distance from the ends of the bent rod, it will be attracted by them, and adhere. TTie electricity flowing around the iron rod, has rendered the rod magnetic ; its ends are now magnetic poles. (See Lesson III.) The galvanic current now travels from the carbon along the wire, passes through the place where the wires are fastened together, and enters the wire leading to the horse- shoe. Then it runs through all the windings of the two coils, and, in doing so, constantly flows around the iron rod. Leaving the iron rod at the other end, it passes along the copper wire, enters the (zinc) wire where the two wires are connected with each other, and, finally, arrives again at the zinc, whence it starts again to make the same travel anew. Disconnect one of the wires, either by withdrawing one hand, or by untwisting the wire ends; if the iron rod is of the right kind, the piece of soft iron attached will drop instantly. If held up against the poles again, it will not be attracted so long as the wires remain disconnected. The iron rod shows no trace of magnetism. Evidently it was magnetic only as long as the electric current flowed around it.1 Iron becomes magnetic when an electric current passes around it in many windings. When the current is interrupted, it ceases to be magnetic. Such an iron rod has usually the shape of a horse-shoe, or hair-pin, and is called an ElectroMagnet. The piece of soft iron applied to its poles is called the Keeper. Principles of the Electric Telegraph. I. According to Lesson III, magnets have the power of attracting iron ; by means of alternately closing and breaking the electric current, the electro-magnet renders apiece of soft iron alternately magnetic and unmagnetic. terial ; it may be thousands of miles. Thus a battery may be in the city of New York, while the electro-magnet with which it is connected is set up in St. Louis, a distance of 1200 miles of wire. III. A person stationed at the battery, may, by disconnecting and connecting the wires, "break and close the current at his pleasure. The three principles can be demonstrated by a simple apparatus shown in Fig. 38. Two upright pieces of board, M N, are fastened to a table so as to admit the rent passes through A, the poles of the Electromagnet attract the Keeper d e; but on breaking the current by disconnecting one of the wires, the Keeper will drop. To prevent its dropping too far, there is a wooden support, g, which does not allow the Keeper to separate from the poles of the Electro -magnet more than perhaps 1-10 of an inch. The paper pasted on the Keeper immediately disconnects the latter from the poles of the magnet when the current is broken. Lastly, a wooden point, f, writes the message upon an endless band of paper, which is unwound from a cylinder above it. This cylinder is not represented in the drawing. When the keeper is attracted by the magnet, the point f makes a mark or indentation, on the paper. But when the current is interrupted, the Keeper drops, and the point drops at the same time ; consequently no mark is then made. To represent the letter a, for example, a sign : , is impressed upon the paper ; the operator at the delivery station closes the current for an instant only, this produces the small line — ; then he breaks it, but immediately afterward closes it again, and keeps it closed three times as long as unfinished part of any previous lesson can be brought up. LESSON VII. — Time is gained if the bullets are flattened with a hammer ; then scrape one of the flattened surfaces of each with a knife ; press the two surfaces together by a few strokes of a hammer. the slab. LESSON X. — A piece of India-rubber tubing around the tube of the funnel will do as well as sealing-wax, or any other cement. Any kind of tube, about ^ inch in diameter and about 3 feet long, may serve as a blow-pipe. LESSON XVI. — A square wooden beam about 20 inches long for a lever, with the sharp edge of a ruler, paper knife or knife-blade as a fulcrum. The fulcrum must be firmly fixed. LESSON XVIII. — The bees-wax must be put on very thin, or else the water cannot force its way through. Draw Fig. 1 7 on the board. The small triangular valve, when lowered, is just large enough to close the right hand side of the short horizontal tube. LESSON XXXV — EXPERIMENT 65. — Draw an arrow on the board, place the prism in proper position, and sufficiently elevated for each scholar to see the arrow through the prism. As this requires but a few seconds, it may be found convenient to let the class slowly file past the prism* 1. To CUT A GLASS TUBE. — Take glass tubing about # -inch external diameter ("hard glass " is preferable). For a Hero's fountain (Lesson X, Experiment 27, and also frontispiece), it should reach from within half an inch of the bottom of the flask to about eight inches above the cork. To do this, lay the tube on a table, hold it between the thumb and forefinger of the left hand, placed close to where it is to be cut. Take a triangular file, press your left thumb and forefinger firmly against the tube, put the edge of the file upon the tube so as to touch and lean against the thumb, which will thus prevent the file from slipping over the glass, and make a notch on the glass by a few short, energetic strokes in a forward direction. While in the act of cutting, do not bear down too heavily with the left hand; rather have your left thumb yield a little as the file passes forward, so that the tube may turn a little in the direction of the advancing file. To guard against injury, in case the tube should yield, put on a glove. Now take up the tube, holding it so that the thumb-nails are opposite to each other, with the notch between them, and that you tightly press the tube (where the notch is) with thumb-nail and forefinger of each hand, and with a resolute grasp break the tube (moving your hands in a direction front you) as you would break a stick. The edges of the new end will be sharp and rugged; to prevent their tearing the cork, pass the file lightly over them; then hold them a few seconds in the tip of an alcohol (or gas) flame. 2. To BEND A GLASS TUBE. — If the external diameter of the tube does not exceed half an inch, a common gas flame is very suitable ; but if the gas is not at hand, a spirit lamp with a large flame may be used. Light the gas, or spirit lamp ; then holding the piece of tube by its extremities, bring it a little above the flame, turning it constantly around and moving it laterally so as to heat about two inches of it equally on both sides. After a few seconds lower it gradually into the flame, still constantly turning it round. If the gas burner be used, the glass will become covered with soot when immersed in the flame ; but this is of no consequence, as the heat of such a burner is never high enough to incorporate the carbon with the glass. When the heated portion becomes soft and yielding, which will take place even before it has acquired a visible red heat, withdraw it from the flame, and gently bend it to a right angle, avoiding the use of much force. When the proper bend is completed, lay the tube on a bit of glass in such a position that the heated portion does not come into contact with any cold surface, and leave it to cool slowly. GLASS AND CORK WORKING. 173 the extent of half an inch in the upper part of a flame. The thumb and forefinger of each hand should hold the glass about an inch from the heated part. The heated part will soon become soft and a little narrower. Then withdraw it from the flame, and draw the heated part out by pulling the two ends of the glass apart. »But pull very gently or else the tube will be drawn out too thin; the jet should have about j^-inch external diameter. Gently place the whole on the table before you and allow it to cool ; then make a fine notch at the middle of the drawn-out part, and break the tube there. The long part is the jet for a Hero's fountain. If the aperture is too wide, hold it for a second or two in the flame. 4. To PERFORATE A CORK.— It now remains to fit these tubes — the bent tube and the jet — to the bottle by means of a cork having two holes. Take a good, sound cork, about an inch in diameter, squeeze it until it becomes soft and elastic (a pair of pliers or nut-crackers will serve the purpose of a regular cork-squeezer), then take it up between the second finger and the thumb of the left hand, and place the sharpened end of the smallest cork-borer against it, one end of the cork midway between the center and the edge. Urge the cork-borer into the cork with a twisting motion, as if you were using a cork screw. Some care will be required to make the hole straight through the cork, so that it may be truly central. Of the proper direction the eye will be the best judge. And when the cork-borer has penetrated some little way, it will be advisable to turn the cork a quarter round in order that it may be seen whether the axis of the cork-borer and of the cork are still in the same straight line. If not, a slight pressure on the cork-borer in one directi'm or the other will set it straight. When the borer has penetrated ^aite through the cork, it may be withdrawn with a twitching motion, and will bring with it a cylindrical plug of cork, leaving a hole, the sides of which should be smoothed with a round file. In the same manner make the other hole midway between the center and the circumference. Take a cork-borer rather smaller than the tubing which you have ; see that the holes do not run into each other, or pierce the side of the cork. The holes should next be smoothed and slightly enlarged by a rat-tail file, until the end of one of the tubes will just enter them when some little pressure is used. (If much pressure is used, the tube is not unlikely to break, and the splinters of glass may cause injury. The hole should never be so much smaller than the tube as to make it necessary to use much force in passing the latter through it. It is a good plan, also, to wrap the tube in a cloth or handkerchief while it is being inserted in the cork. ) Now pass the longer of the two tubes through the cork, with moderate pressure and a twisting motion, until it projects so far as to reach, when the cork is fitted into its place, nearly to the bottom of the bottle. When this is done pass the other tube through the other hole in the cork," until it projects one or two inches on the other side.	36,898	common-pile/pre_1929_books_filtered	firstlessonsin00hotzrich	public_library	public_library_1929_dolma-0005.json.gz:3134	https://archive.org/download/firstlessonsin00hotzrich/firstlessonsin00hotzrich_djvu.txt
fNTFsEevVyuBD8vW	Developmental Psychology	41 Early childhood is a time of pretending, blending fact and fiction, and learning to think of the world using language. As young children move away from needing to touch, feel, and hear about the world toward learning some basic principles about how the world works, they hold some pretty interesting initial ideas. For example, how many of you are afraid that you are going to go down the bathtub drain? Hopefully, none of you do! But a child of three might really worry about this as they sit at the front of the bathtub. A child might protest if told that something will happen “tomorrow” but be willing to accept an explanation that an event will occur “today after we sleep.” Or the young child may ask, “How long are we staying? From here to here?” while pointing to two points on a table. Concepts such as tomorrow, time, size and distance are not easy to grasp at this young age. Understanding size, time, distance, fact and fiction are all tasks that are part of cognitive development in the preschool years. Preoperational Intelligence Piaget’s stage that coincides with early childhood is the preoperational stage. The word operational means logical, so these children were thought to be illogical. However, they were learning to use language or to think of the world symbolically. Let’s examine some Piaget’s assertions about children’s cognitive abilities at this age. Pretend Play: Pretending is a favorite activity at this time. A toy has qualities beyond the way it was designed to function and can now be used to stand for a character or object unlike anything originally intended. A teddy bear, for example, can be a baby or the queen of a faraway land! Piaget believed that children’s pretend play helped children solidify new schemes they were developing cognitively. This play, then, reflected changes in their conceptions or thoughts. However, children also learn as they pretend and experiment. Their play does not simply represent what they have learned (Berk, 2007). Egocentrism: Egocentrism in early childhood refers to the tendency of young children to think that everyone sees things in the same way as the child. Piaget’s classic experiment on egocentrism involved showing children a 3 dimensional model of a mountain and asking them to describe what a doll that is looking at the mountain from a different angle might see. Children tend to choose a picture that represents their own, rather than the doll’s view. However, when children are speaking to others, they tend to use different sentence structures and vocabulary when addressing a younger child or an older adult. This indicates some awareness of the views of others. Syncretism: Syncretism refers to a tendency to think that if two events occur simultaneously, one caused the other. I remember my daughter asking that if she put on her bathing suit whether it would turn to summer! Animism: Animism refers to attributing life-like qualities to objects. The cup is alive, the chair that falls down and hits the child’s ankle is mean, and the toys need to stay home because they are tired. Watch this segment in which the actor Robin Williams sings a song to teach children the difference between what is alive and what is not alive. (Interesting, the puppets in the background sing and dance the phrase “it’s not alive”. This might be a bit confusing to the viewers!). Cartoons frequently show objects that appear alive and take on lifelike qualities. Young children do seem to think that objects that move may be alive but after age 3, they seldom refer to objects as being alive (Berk, 2007). Classification Errors: Preoperational children have difficulty understanding that an object can be classified in more than one way. For example, if shown three white buttons and four black buttons and asked whether there are more black buttons or buttons, the child is likely to respond that there are more black buttons. As the child’s vocabulary improves and more schemes are developed, the ability to classify objects improves. Conservation Errors: Conservation refers to the ability to recognize that moving or rearranging matter does not change the quantity. Imagine a 2 year old and a 4 year old eating lunch. The 4 year old has a whole peanut butter and jelly sandwich. He notices, however, that his younger sister’s sandwich is cut in half and protests, “She has more!” Watch the following examples of conversation errors of quantity and volume: Theory of Mind Imagine showing a child of three a bandaid box and asking the child what is in the box. Chances are, the child will reply, “bandaids.” Now imagine that you open the box and pour out crayons. If you ask the child what they thought was in the box before it was opened, they may respond, “crayons”. If you ask what a friend would have thought was in the box, the response would still be “crayons”. Why? Before about 4 years of age, a child does not recognize that the mind can hold ideas that are not accurate. So this 3 year old changes his or her response once shown that the box contains crayons. The theory of mind is the understanding that the mind can be tricked or that the mind is not always accurate. At around age 4, the child would reply, “Crayons” and understand that thoughts and realities do not always match. This awareness of the existence of mind is part of social intelligence or the ability to recognize that others can think differently about situations. It helps us to be self-conscious or aware that others can think of us in different ways and it helps us to be able to be understanding or empathic toward others. This mind reading ability helps us to anticipate and predict the actions of others (even though these predictions are sometimes inaccurate). The awareness of the mental states of others is important for communication and social skills. A child who demonstrates this skill is able to anticipate the needs of others. This video describes a research in which theory of mind is linked to popularity. Language Development Vocabulary growth: A child’s vocabulary expands between the ages of 2 to 6 from about 200 words to over 10,000 words through a process called fast-mapping. Words are easily learned by making connections between new words and concepts already known. The parts of speech that are learned depend on the language and what is emphasized. Children speaking verb-friendly languages such as Chinese and Japanese as well as those speaking English tend to learn nouns more readily. But those learning less verb-friendly languages such as English seem to need assistance in grammar to master the use of verbs (Imai, et als, 2008). Children are also very creative in creating their own words to use as labels such as a “take-care-of” when referring to John, the character on the cartoon, Garfield, who takes care of the cat. Literal meanings: Children can repeat words and phrases after having heard them only once or twice. But they do not always understand the meaning of the words or phrases. This is especially true of expressions or figures of speech which are taken literally. For example, two preschool aged girls began to laugh loudly while listening to a tape-recording of Disney’s “Sleeping Beauty” when the narrator reports, “Prince Phillip lost his head!” They image his head popping off and rolling down the hill as he runs and searches for it. Or a classroom full of preschoolers hears the teacher say, “Wow! That was a piece of cake!” The children began asking “Cake? Where is my cake? I want cake!” Overregularization: Children learn rules of grammar as they learn language but may apply these rules inappropriately at first. For instance, a child learns to ad “ed” to the end of a word to indicate past tense. Then form a sentence such as “I goed there. I doed that.” This is typical at ages 2 and 3. They will soon learn new words such as went and did to be used in those situations. The Impact of Training: Remember Vygotsky and the Zone of Proximal Development? Children can be assisted in learning language by others who listen attentively, model more accurate pronunciations and encourage elaboration. The child exclaims, “I’m goed there!” and the adult responds, “You went there? Say, ‘I went there.’ Where did you go?” Children may be ripe for language as Chomsky suggests, but active participation in helping them learn is important for language development as well. The process of scaffolding is one in which the guide provides needed assistance to the child as a new skill is learned. Private Speech: Do you ever talk to yourself? Why? Chances are, this occurs when you are struggling with a problem, trying to remember something, or feel very emotional about a situation. Children talk to themselves too. Piaget interpreted this as egocentric speech or a practice engaged in because of a child’s inability to seeing things from others points of views. Vygotsky, however, believed that children talk to themselves in order to solve problems or clarify thoughts. As children learn to think in words, they do so aloud before eventually closing their lips and engaging in private speech or inner speech. Thinking out loud eventually becomes thought accompanied by internal speech and talking to oneself becomes a practice only engaged in when we are trying to learn something or remember something, etc. This inner speech is not as elaborate as the speech we use when communicating with others (Vygotsky, 1962).	2,069	common-pile/pressbooks_filtered	https://library.achievingthedream.org/herkimerdevelopmentalpsych/chapter/cognitive-development-2/	pressbooks	pressbooks-0000.json.gz:42894	https://library.achievingthedream.org/herkimerdevelopmentalpsych/chapter/cognitive-development-2/
k5eVTQ76ZN-C4j9p	Circular of information for intending applicants for certificate as certified public accountant under the law of Montana in effect February 27, 1909.	BOARD OF EXAMINERS IN ACCOUNTANCY LOUIS G. PELOUBET, C. P. A., Hennessy Building, Butte. J. C. PHILLIPS, C. P. A, Miner Building, Butte. DONALD ARTHUR, C. P. A, Lewisohn Building, Butte. CERTIFIED PUBLIC ACCOUNTANT Chapter 39 of the Session Laws of 1909, enacted by the Eleventh Legislative Assembly of the State of Montana, effective February 27th, 1909, provides for the regulation of the practice of public accounting in this State. The State University administers this law and issues certificates of competency to any person who : ing acquired in practice on his own account, or in the office of a public accountant, or in a responsible accounting position in the employ of a business corporation, firm or individual ; persons having certificates of other states or countries, or under the provision for the exemption of experienced accountants now practicing in the State; and prescribed by the law. The above mentioned examinations are ^held at least once each year and at least thirty days' notice of the time and place of holding is given by advertisement in three representative daily newspapers of the State. Board of Examiners. The application blank must be filled out in the candidate's own handwriting and signed and sworn to by the candidate in the presence of some one authorized under the laws of Montana to administer an oath, and, together with a bank draft or money order for twenty-five dollars (125.00), payable to "University of Montana'', be mailed to the University at Missoula. If the University approves the application the candidate will receive a card of admission to the examination, and if he succeeds in passing the examination he will in due course receive a certificate. be returned. In no event will the fee of twenty-five dollars (\|25.00) be returned to the applicant after his application has been approved, but any candidate failing to pass the examination is entitled to take any one subsequent examination without payment of a second fee. public accountants of the State of Montana appointed by the President of the University. The law provides for the revocation of certificates for unprofessional conduct or other sufficient cause and for the punishment of any person falsely representing himself as being a Certified Public Accountant or as holding such a certificate. following applicants : First, those who hold certificates as '^Certified Public Accountant" in another State extending like privilege to this State; provided, that in the opinion of the Board of Examiners the requirements for such certificates are equivalent to the requirements in this State. Second, those holding similar certificates of another country, the requirements for which are equivalent to those in this State; provided, that the applicant is either a citizen or has 'declared his intention to become such. Third, persons of at least twenty-five years of age, whose qualifications are equal to those prescribed for applicants for examination, who are known to the Board of Examiners as competent and skilled accountants; provided, they shall apply for certificates within one hundred and eighty days after the passage of the act. Applicants under any of these provisions may obtain blanks from the University or the Board of Examiners and must pay the fee of twenty-five dollars as prescrilied. These applications will be acted upon in the same manner as those for examination. STANDARD OF EDUCATION The Montana law regulating the practice of the profession of public accounting fixes the standard of general education required for the certificate and imposes upon the State Universitv the duty of fixing the standard of special and technical education to be required. The University accordingly states the following policy for the guidance of practicing accountants : ancy to the dignity of a liberal profession without the aid of the practicing accountants themselves, nor can the practicing accountants do so without the aid of the schools; first, upon the establishment by educational institutions of courses covering subjects essential to the highest development of accountancy; and, second^ upon the efforts of each practicing accountant to increase and broaden his own education ; aminers first appointed under the law that the standard of special and technical education now to be adopted shall be fixed by the existing facilities for acquiring an education in accountancy and by the average standard of the body of public accountants at present in practice; and further, that the standard so fixed must be raised from time to time to keep pace with the greater facilities furnished and the advances made by the practicing accountants themselves.	972	common-pile/pre_1929_books_filtered	circularofinform00univ	public_library	public_library_1929_dolma-0008.json.gz:2845	https://archive.org/download/circularofinform00univ/circularofinform00univ_djvu.txt
PmTCBjq0FibyKWHG	Flint and Feather	The White Wampum Re-Voyage What of the days when we two dreamed together? Days marvellously fair, As lightsome as a skyward floating feather Sailing on summer air— Summer, summer, that came drifting through Fate’s hand to me, to you. What of the days, my dear? I sometimes wonder If you too wish this sky Could be the blue we sailed so softly under, In that sun-kissed July; Sailed in the warm and yellow afternoon, With hearts in touch and tune. Have you no longing to re-live the dreaming, Adrift in my canoe? To watch my paddle blade all wet and gleaming Cleaving the waters through? To lie wind-blown and wave-caressed, until Your restless pulse grows still? Do you not long to listen to the purling Of foam athwart the keel? To hear the nearing rapids softly swirling Among their stones, to feel The boat’s unsteady tremor as it braves The wild and snarling waves? What need of question, what of your replying? Oh! well I know that you Would toss the world away to be but lying Again in my canoe, In listless indolence entranced and lost, Wave-rocked, and passion tossed. Ah me! my paddle failed me in the steering Across love’s shoreless seas; All reckless, I had ne’er a thought of fearing Such dreary days as these, When through the self-same rapids we dash by, My lone canoe and I.	300	common-pile/pressbooks_filtered	https://pressbooks.library.torontomu.ca/flintandfeather/chapter/re-voyage/	pressbooks	pressbooks-0000.json.gz:17106	https://pressbooks.library.torontomu.ca/flintandfeather/chapter/re-voyage/
FNmWys8rzQI2d5DZ	5.4E: Exercises - Combinations	5.4E: Exercises - Combinations - - Last updated - - Save as PDF - Do the following problems using combinations. - How many different 3-people committees can be chosen from ten people? \| - How many different 5-player teams can be chosen from eight players? \| - In how many ways can a person chose to vote for three out of five candidates on a ballot for a school board election? \| - Compute the following: - 9C2 - 6C4 - 8C3 - 7C4 \| - How many 5-card hands can be chosen from a deck of cards? \| - How many 13-card bridge hands can be chosen from a deck of cards? \| - There are twelve people at a party. If they all shake hands, how many different hand-shakes are there? \| - In how many ways can a student choose to do four questions out of five on a test? \| - Five points lie on a circle. How many chords can be drawn through them? \| - How many diagonals does a hexagon have? \| - There are five teams in a league. How many games are played if every team plays each other twice? \| - A team plays 15 games a season. In how many ways can it have 8 wins and 7 losses? \| - In how many different ways can a 4-child family have 2 boys and 2 girls? \| - A coin is tossed five times. In how many ways can it fall three heads and two tails? \| - The shopping area of a town is a square that is six blocks by six blocks. How many different routes can a taxi driver take to go from one corner of the shopping area to the opposite cater-corner? \| - If the shopping area in the previous problem has a rectangular form of 5 blocks by 3 blocks, then how many different routes can a taxi driver take to drive from one end of the shopping area to the opposite kitty corner end? \| - A team of 7 workers is assigned to a project. In how many ways can 3 of the 7 workers be selected to make a presentation to the management about their progress on the project? \| - A real estate company has 12 houses listed for sale by their clients. In how many ways can 5 of the 12 houses be selected to be featured in an advertising brochures? \| - A frozen yogurt store has 9 toppings to choose from. In how many ways can 3 of the 9 toppings be selected ? \| - A kindergarten teacher has 14 books about a holiday. In how many ways can she select 4 of the books to read to her class in the week before the holiday? \| The following problems involve combinations from several different sets. - How many 5-people committees consisting of three boys and two girls can be chosen from a group of four boys and four girls? \| - A club has 4 men, 5 women, 8 boys and 10 girls as members. In how many ways can a group of 2 men, 3 women, 4 boys and 4 girls be chosen? \| - How many 4-people committees chosen from 4 men and 6 women will have at least 3 men? \| - A batch contains 10 transistors of which three are defective. If three are chosen, in how many ways can they be selected with two defective? \| - In how many ways can five counters labeled A, B, C, D and E at a store be staffed by two men and three women chosen from a group of four men and six women? \| - How many 4-letter word sequences consisting of two vowels and two consonants can be made from the letters of the word PHOENIX if no letter is repeated? \| Three marbles are chosen from an urn that contains 5 red, 4 white, and 3 blue marbles. How many samples of the following type are possible? - All three white. \| - Two blue and one white \| - One of each color. \| - All three of the same color. \| - At least two red. \| - None red. \| The following problems involve combinations from several different sets. Five coins are chosen from a bag that contains 4 dimes, 5 nickels, and 6 pennies. How many samples of five coins of the following types are possible? - At least four nickels. \| - No pennies. \| - Five of a kind. \| - Four of a kind. \| - Two of one kind and two of another kind. \| - Three of one kind and two of another kind. \| Find the number of different ways draw a 5-card hand from a deck to have the following combinations. - Three face cards. \| - A heart flush (all hearts). \| - Two hearts and three diamonds \| - Two cards of one suit, and three of another suit. \| - Two kings and three queens. \| - 2 cards of one value and 3 of another value \| The party affiliation of the 100 United States Senators in the 114 th Congress, January 2015, was: 44 Democrats, 54 Republicans, and 2 Independents. - In how many ways could a 10 person committee be selected if it is to contain 4 Democrats, 5 Republicans, and 1 Independent? \| - In how many different ways could a 10 person committee be selected with 6 or 7 Republicans and the Democrats (with no Independents)? \| The 100 United States Senators in the 114 th Congress, January 2015, included 80 men and 20 women. Suppose a committee of senators is working on legislation about wage discrimination by gender. - In how many ways could a 12 person committee be selected to contain equal numbers of men and women. \| - In how many ways could a 6 person committee be selected to contain fewer women than men? \|	1,313	common-pile/libretexts_filtered	https://math.libretexts.org/Under_Construction/Purgatory/MAT_1320_Finite_Mathematics/05%3A_Sets_and_Counting/5.04%3A_Combinations/5.4E%3A_Exercises_-_Combinations	libretexts	libretexts-0000.json.gz:8947	https://math.libretexts.org/Under_Construction/Purgatory/MAT_1320_Finite_Mathematics/05%3A_Sets_and_Counting/5.04%3A_Combinations/5.4E%3A_Exercises_-_Combinations
qFyw4dDUG_s0C04b	Seed corn / by C.P. Hartley.	W ashing ton, D. C., July 22, 1910. Sir: I have the honor to transmit herewith a manuscript entitled “ Seed Corn,” by Mr. C. P. Hartley, Physiologist in Charge of Corn Investigations, and recommend that it be published as a Farmers’ Bulletin. Each spring during corn-planting time, first from the Southern, then from the Central, and later from the Northern States, the United States Department of Agriculture receives thousands of anxious inquiries for sources from which good seed corn can be pur¬ chased. This bidletin should prove a timely reply to future inquiries of this nature. Any farmer can apply the suggestions made in these pages, and by so doing provide himself with the best seed corn his community affords, which is likely to produce a better crop than any seed he can purchase at planting time. SMALL YIELDS DUE TO POOR SEED CORN CAN BE PREVENTED. The average production of corn to the acre for the entire United States is but 26 bushels, yet in practically every section four times that quantity is frequently joroduced. Improvement of the quality of seed is the least expensive method of increasing the yield per acre. There is each spring a scarcity of good seed corn. This condition is all the more regrettable because it need not exist and it is much more serious than commonly supposed because many do not fully realize the tremendous loss to themselves and the country due to planting inferior seed. A full stand of plants may be obtained from inferior seed, but the yield will not be the best possible. The loss is due to delay or negligence. It can be prevented by the selection of seed corn in the autumn. If good seed corn could be manufactured in a few weeks’ time many factories would be working day and night from March till June. Each spring the writer regrets the unfortunate position of many thousands who too late inform the United States Department of Agriculture of their willingness to pay good prices for good seed corn and of their inability to obtain it. THE VERY BEST SEED IS AVAILABLE AT RIPENING TIME. Autumn is the time to prepare for a profitable corn crop the follow¬ ing season. It is hoped that this bulletin will prove more valuable and timely than any replies that can be written to springtime corre¬ spondents regarding seed corn. Its object is to prevent the scarcity a Copies of any of the following Farmers’ Bulletins upon the subject of corn will be sent free of charge upon application to a Senator or Representative in Congress or to the Secretary of Agriculture : 81, Corn Growing in the South ; 229, The Production of Good Seed Corn ; 253, The Germination of Seed Corn ; 272, A Successful Hog and Seed-Corn Farm ; 298, Food Value of Corn and Corn Products; 303, Corn-Harvesting Machinery; 313, Harvesting and Storing Corn; 325, Small Farms in the Corn Belt; 400, A More Profitable Corn-Planting Method ; 414, Corn Cultivation. SEED CORN. each spring of first-class seed corn. This scarcity can be prevented by selecting the seed when it is most abundant and when the very best can be obtained — at ripening time before it has been in any way reduced in vitality. Many let this opportunity pass, expecting to purchase their seed corn, only to find that they can not buy at any price in the winter or spring as good seed as they could have selected in the autumn. WHERE TO OBTAIN THE BEST POSSIBLE SEED CORN. Until a community has its experienced and honest corn breeder, the best place for the farmer to obtain seed corn is from fields on his farm or in his neighborhood that were planted with a variety that has generally proved most successful in that locality. CORN BREEDING IS A SPECIAL LINE OF WORK. Well-conducted corn breeding requires special methods that gen¬ eral farmers have not time to apply. If there is in your locality a corn breeder who each year demonstrates the superiority of his corn, you should pay him well for his superior seed. Five dollars a bushel will be a profitable bargain for both parties. Such corn breeders are improving corn as cattle breeders have improved cattle. The general farmer is a propagator rather than a breeder of corn. He profits by the careful work of the breeder by adopting the higher yielding strains and propagating them.® time in a manner that will retain its full vigor. The importance of the three requirements just enumerated has been demonstrated experimentally by the Office of Corn Investigations of the Bureau of Plant Industry. The results given briefly, as enumerated, are as follows: in others. (2) Seed ears taken from the highest yielding rows of ear-to-row breeding plats have repeatedly produced better than seed ears taken from poorer yielding rows. Seed ears from the best producing stalks found in a general field produced more than seed ears taken without considering the productiveness of the parent stalks. (3) Four bushels of ears were divided into two equal parts, one part being well taken care of and the other placed in a barn as corn is ordinarily cribbed. The well-preserved seed gave a 12 per cent increase in production on poor soil and a 27 per cent increase on fertile soil, notwithstanding the fact that both lots of seed germi¬ nated equally well.® At corn-ripening time drop all other business and select an abun¬ dance of seed corn. The process is too important to be conducted incidentally while husking. When selecting seed corn give the process your entire attention. Get the very best that is to be had and preserve it well, and your increased yields will return you more profit than any other work you can do on your farm. PROPAGATE ONLY FROM THE BEST PRODUCING PLANTS. As soon as the crop ripens, go through the field with seed-picking bags (fig. 1)* & and husk the ears from the stalks that have produced the most corn without having any special advantages, such as space, moisture, or fertility. Avoid the large ears on stalks standing singly with an unusual amount of space around them. Preference should be given the plants that have produced most heavily in competition with a full stand of less productive plants. heavily of sound, dry, shelled corn is of most importance. Late-maturing plants with ears which are heavy because of an excessive amount of sap should be ignored. Sappiness greatly in¬ creases the weight and is likely to destroy the quality. TREATMENT OF SEED IMMEDIATELY AFTER GATHERING. The same day seed corn is gathered the husked ears should be put in a dry place where there is free circulation of air, and placed in such a manner that the ears do not touch each other. This is the only safe procedure. The writer has repeatedly seen good seed ruined Fig. 1. — A field of corn showing a good method of selecting seed. The men are search¬ ing for plants that have produced heavily under average conditions and in close com¬ petition with less productive plants in the same and adjacent hills. because it was thought to be already dry enough when gathered and that the precaution mentioned above was unnecessary. Many farmers believe that their autumns are so dry that such care is superfluous. Seed corn in every locality gathered at ripening time will be benefited by drying as suggested. If left in the husk long after ripening it may sprout or mildew during warm, wet weather or become infested with weevils. The vitality of seed is often reduced by leaving it in a sack or in a pile for even a day after gathering. During warm weather, with some moisture in the cobs and kernels, the ears heat or mildew in a remarkably short time. The best possible treatment immediately after gathering is shown in figure 2. Binder twine will support 15 or 20 ears on a string, ar¬ ranged in the manner illustrated. Ordinarily the best place to hang these strings of ears is in an open shed or loft. Only during unusually damp weather at seed -gathering time will fire be necessary. If heat is employed in a poorly ventilated room it will do the seed ears more injury than good. If used the fire should be slow, long continued, and situated below the seed ears with good ventilation above them. must not be exposed to a damp atmosphere or they will absorb mois¬ ture and be injured. Some farmers place the thoroughly dried seed ears in the center of a wheat bin and fill the bin with loose, dry wheat. PREVENTING INJURY FROM WEEVILS AND GRAIN MOTHS. In localities where weevils and grain moths injure stored grain, the thoroughly dry seed ears should be stored in very tight mouseproof receptacles, with 1 pound of moth balls or napthalene inclosed for each bushel of corn. This quantity tightly inclosed with the corn will prevent damage from these insects and will not injure the seed. The material will cost about 3 cents a pound. Thirty cents’ worth will protect seed enough to plant 60 acres. TESTING THE GERMINATION OF SEED CORN. Seed corn that matured normally and has been properly preserved will grow satisfactorily. It is very poor management to neglect proper preservation and to spend time in the spring separating by germinating tests those ears that have been badly damaged from those that have been slightly damaged. Prevention is better than cure, and in this case a cure is impossible. but will produce less than if they had received better care. Make a seed-corn testing box° and test 100 ears separately. Be sure that each kernel tested is perfect in appearance and was not injured at the tip when removed from the ear. If 3 or more kernels out of 10 from any ear fail to grow, it will be advisable to test every ear in the entire supply of seed corn. If the 100 ears tested contain no poor ones, further testing of the supply is unnecessary. Shelled corn is difficult to grade satisfactorily. The grading can be done better before the ears are shelled. If the seed ears vary greatly as to size of kernel they should be separated into two or three grades according to size of kernel. These grades should be shelled separately, tested in the corn planter, and numbered to correspond with the number on the planter plates that are found to drop them most uniformly. These arrangements can be completed before the rush of spring work begins. SEED EARS SHOULD FIRST BE NUBBED. The first operation in properly shelling seed corn is the removal of the small kernels -from the tips of the ears and the round thick kernels from the butts. The former are less productive than the other kernels of the ear. The round butt kernels are as productive as the other kernels of the ear, but do not plant uniformly in a planter. HAND SHELLING IS THE BEST METHOD. Shelling seed corn carefully by hand is profitable. The greater the acreage planted the greater the profit. Into a shallow pan or box each ear should be shelled separately, rejecting any worm-eaten or blemished kernels. If the supply from the one ear appears good and contains no poor kernels, it is poured into the general supply and another ear shelled in the same way. SUMMARY. If you have ever found yourself compelled to plant corn that was not fit for seed, do not be caught that way again. It is too discour¬ aging to begin the season with poor prospects of a good crop. Get your seed at ripening time when the best quality is most plentiful. Get an abundance, enough for planting again what the high water may destroy and a supply for some farmer who may move into your community or for a neighbor who could not select his seed corn at the proper time. Care for each living kernel from the time it ripens until it is planted in a manner that will enable it to develop into a thrifty plant and produce one or more large ears. Do not expect germination tests made in the spring to restore vigor that proper gathering, drying, and storing would have retained.	2,678	common-pile/pre_1929_books_filtered	seedcorn4014hart	public_library	public_library_1929_dolma-0024.json.gz:693	https://archive.org/download/seedcorn4014hart/seedcorn4014hart_djvu.txt
aU2ULVPviLOuhiub	Principles & practice of judging live-stock.	Warren, FARM MANAGEMENT. Lyon and Pippin, SOIL MANAGEMENT. J. F. Duggar, SOUTHERN FIELD CROPS. B. M. Duggar, PLANT PHYSIOLOGY. Harper, ANIMAL HUSBANDRY FOR SCHOOLS. Montgomery, CORN CROPS. Widtsoe, IRRIGATION PRACTICE. Piper, FORAGE PLANTS AND THEIR CULTURE. Hitchcock, TEXT-BOOK OF GRASSES. Gay, THE PRINCIPLES AND PRACTICE OF JUDGING LIVE-STOCK. PREFACE WITH the extension of the live-stock industry and the development of the sciences fundamental thereto, the necessity is felt for striking at the root of things, of getting well under the surface. This necessity is emphasized particularly in the matter of live-stock judging. The study of feeds and feeding, of the principles of breeding, and of systems of live-stock management have progressed further along scientific lines than has the study of live-stock judging. Doubtless there are many buyers and breeders of animals whose judgment is more accurate, even, than that of the trained expert, but there is neither science nor system in their reasoning and they cannot tell why they so decide. In order that others may be trained in ways of live-stock improvement it is important that our knowledge of animal excellence be increased, our powers of observation and perception made more keen, our judgment in making comparisons more logical, and our decisions more accurate. To do this requires a more exhaustive and scientific study of the subject. The best way to understand the exterior of animal form is to study the interior. Nowadays we make soil surveys where we formerly considered only area and topography. It seems reasonable that the best judge of a steer's loin should be a connoisseur of porterhouse; to prognosticate most closely the durability of a horse's foot one should know all of the com- plicated structures contained within its horny wall and their related functions, as concerned in locomotion. It is not sufficient simply to require that the texture of a cow's udder shall or shall not be thus and so, but reasons should be given in terms of more or less pounds of milk. The nomenclature needs revision and a more consistent use of specific terms might be adopted. Some names are misleading. It is related how a leading agricultural educator had to see the " milk " vein punctured before he would be convinced that blood and not milk flowed through it. If the name " mammary vein " were employed instead of " milk vein," no such erroneous meaning would be conveyed. Some regions which are specifically designated cannot be definitely described. No one can determine, for instance, just where the shoulder vein of the steer becomes neck on the one side and shoulder on the other. Some terms with a distinct significance are used loosely and interchangeably. It is the fore quarter of the steer but the fore hand of the horse ; the rump of the cow, the croup of the horse. The appearance of the dairy cow is spare or lean, not thin. The draft horse is compact while the heavy harness horse is closely made, and to say that the latter is compact is to suggest draftiness, a feature which he should not possess. It would be as impracticable to drop the objectionable names in common usage as it is unscientific to retain them ; the intelligent husbandman should command them both in order to converse intelligently with either the stockmen whom he must cultivate and from whom he derives much of his inspiration and knowledge of the work, or those students whose instructor he may be. along this line than he has gone heretofore. Care has been exercised not to sacrifice the popular phase upon which our knowledge of the subject is based but to bridge over onto a more technical consideration of it. It is hoped that the author's intention of keeping the work thoroughly practical, yet giving it a touch of a somewhat technical nature, will be appreciated by students 46. The canter, the hind foot bearing the weight and beginning a new series of three beats at the phase of contact, after the horse has been projected clear of the ground by the independent forefoot. (Courtesy kDevon Horse Show Ass'n) 105 99 B. Alveoli of the mammary gland of goat at the time of parturition, showing successive stages of secretion. (Grimmer, Chemie und Physiologie der Milch, Paul GENERAL VIEW THE ultimate object of live-stock husbandry is the production of market animals and their products, an end which is attained by two steps or stages, breeding and feeding. The one furnishes the raw material, the other finishes the product. Thus there are two groups of husbandmen, those concerned with the production of the animal machine and those engaged in the employment of this machine for the manufacture of animal products. There are, furthermore, two classes of breeders, one whose efforts are devoted to the breeding of foundation stock and the improvement of the race in general, another whose purpose is to supply the feeders from their studs, herds and flocks. The latter are obviously dependent upon the former. The breeder either may finish or work his own stock, as is usually the case with hogs and commonly with horses, dairy cattle and sheep, or may dispose of them while immature or thin to the feeder, as is the rule with beef cattle and range sheep. In some instances, therefore, the breeder is also the feeder, while in others the line between them is rather sharply drawn. rial available to the feeder ; with good material insured, however, it ist incumbent upon the feeder to make the most of the possibilities which the breeder has afforded him. 1. Breeding for improvement. — Breeding, as we commonly interpret the term, consists in regulating the progeny by controlling the parentage, to attain improvement. The constructive breeder aims at more than the mere multiplication of his foundation stock ; he strives for qualitative as well as quantitative improvement with each succeeding generation. Although improvement may be slight in each instance, the cumulative results of a number of generations, the progenitors of which have been carefully selected, may be considerable. This has been the principal factor operating in the evolution of the domestic types and breeds of animals, mutations having been much more useful to plant than, to animal breeders. The bases for the qualitative improvement to which selection is made in the breeding of animals are, in most instances, characters which were originally possessed by them in their feral state and useful only for their own subsistence. Under domestication these natural functions have been perverted, readapted and developed so as to amply serve the needs and purposes of man. The motive governing live-stock improvement has been well expressed by Owen : "Whatever the animal kingdom can afford for our food or clothing, tools, weapons, and armament, whatever the lower creation can contribute to our wants, our comforts, our possessions or our pride, that we sternly exact and take 'at all costs." 2. Selection is judging. — Control of the parents is accomplished by means of selection, and selection is judging. Proficiency in this regard is fundamental, for without judicious matings the breeder's facilities, resources and even the merit of his foundation stock count for little in the long run. The master breeders of live-stock history have all been judges of the first order. It should not be supposed that the activity of the agricultural schools in training students to become expert judges is for the sole purpose of supplying men qualified to tie ribbons in the show ring. Notwithstanding the fact that the placing of show ring awards carries with it great responsibility, since ideals and standards so established serve to lead or mislead the rank and file of livestock breeders, the real benefits of accurate judgment in the show ring are not to be measured by ribbons, plate or cash. They are enjoyed by all consumers of meat or milk, wearers of clothing, and users of horses for either profit or pleasure. The breeder or feeder buyer constitutes the judge, whether he ever officiates in a show ring or not, and those who benefit by his judgment are the consumers of his product. OUR ECONOMY THE highest type of domesticated animal has been defined as the one which constitutes the most efficient machine for making the greatest return, in its specific product, on the raw material consumed. In this it bears an important economic relation to man as a source of food and clothing, and as an auxiliary in work. 3. Economic purpose of animal machine. — Food with air and water are the three essentials for human existence. Food is that which builds up the body and furnishes energy for its activities ; that which brings within reach of the living cells which form the tissues the elements which they need for life and growth. Only such available substances can be called food, no matter what their chemical composition may be. Coal may be fuel for the furnace, but not for cattle ; rough forage like hay may form the basis of cattle rations, but it is not available for man's consumption. It is in the conversion of such raw materials as are not available to man in their present form into animal food products or into horse power for his service that the animal machine serves a most important economic purpose. If man were to eliminate the fruits of animal production from his dietary, there would be of necessity an enormous increase in the cost of living, to compensate for the tremendous loss of the crops of the THE ANIMAL MACHINE 1 field which would be utter waste, or, at best, serve but for fuel if available only in their raw, unconverted state. 4. Intermediate relation of animal to plants and man. — There are about fifteen principal chemical elements of nutrition. They are constituents of the human body, likewise the bodies of animals and plants ; a few of them compose also the three requisites for the maintenance of life, — air, water and soil, the sources of food. We can, therefore, understand the synthetical relationship between man on the one hand, and the original sources of his subsistence on the other, with the plants and animals as intermediary factors. Some of the hydrogen and oxygen required by man is obtained direct from the water he drinks ; more of his oxygen is taken direct from the air he breathes, and in return he gives carbon dioxide, equally essential for plant respiration. The soil, however, contributes to our support only indirectly through the bodies of the plants grown upon it. These plants also make abundant use of the nitrogen of the air, an important function, since nitrogen is a chief constituent of the protoplasm of the human or animal cell, both of which are helpless to draw directly upon the supply in the air. A great wealth of plant products are directly available to man in quantity and variety to meet his nutritive requirements, but the entire body of some plants and the major portion of many others are impossible for human consumption. The corn kernel, after a process of milling, becomes a staple article of food for man, but for every pound of corn there is approximately a pound of stover, which would be absolutely valueless were it not for the ruminant's ability to transform it into digestible, nutritious animal food products, meat and milk. We readily recognize the physical impossibility of a man's consuming sufficient pasture grass or hay to sustain life, although the necessary elements are contained therein; yet from these materials are produced, in large part, the meat we eat and the milk we drink, our two most valuable tissue-building foods. THE FUNCTION OF THE ANIMAL MACHINE 6. Efficiency. — Mechanical efficiency is a matter which involves the character of the materials of construction, the perfection of the individual parts, the accuracy with which they are assembled, the power available for their operation, and the effectiveness of its application and control. Efficiency in the functional capacity of animals is analogous in many respects. Whether in the production of horse power, milk, a carcass, or a fleece, it involves and is directly dependent upon, first, the individual unit of structure, the cell, and its arrangement in the organization of tissue ; second, the gross structure into which the various individual tissues are incorporated ; third, the vital phenomena with which the tissues are engaged for both the maintenance and productiveness of the structure as a whole ; fourth, the manner in which they are governed; and, fifth, the significance of abnormal conditions of structure and the extent to which they may impair function. An elementary consideration of histology, anatomy, physiology and pathology, in their relation to the structures and correlated functions concerned in animal production is, therefore, essential. HISTOLOGY 6. Tissue. — Any tissue is composed of an essential unit of structure, the cell, and an inter-cellular material by means of which the cells are held together. The character of the cells themselves, their arrangement in the inter-cellular substance, its nature, and the proportion of each are what give to tissues their characteristic features. The animal body is composed of four kinds of tissue, i.e. epithelial, connective, muscle and nerve. The general nature of each and its place in the organization of the animal economy should be fully understood in order to pass intelligently upon the relative structural and functional merits of two or more individuals. prises all those which enter into the supportive structure or framework of the body, such as bone, cartilage, ligaments and tendons, and the interstitial tissue of all the organs. All of the connective tissues are more or less fibrous in character (Fig. 2). 9. Muscle tissue. — Muscle tissue may be divided into voluntary and involuntary, the former represented by the skeletal muscles with which the judge is most concerned FIG. 3. — Involuntary muscle in longitudinal section ; the musclecells are often cut obliquely, and hence appear shorter than when the ends. in the matters of locomotion and meat production, the latter entering into the makeup of the heart, the walls of the blood vessels and the intestines, structures having to do with the vital functions. The characteristic feature of muscle tissue is its contractility, which takes place in response to a nerve stimulus (Figs.- 3 and 4). peripheral, made up of the nerve trunks and their nerve endings, which are distributed, in a most general way, to all parts. Nerve tissue has the property of conveying or transmitting impulses to or from the central station or brain, those impulses emanating from the centers and FIG. 5. — Section of portion of a nerve trunk, including three bundles of individual nerve fibers surrounded by the perineurium (p) ; the bundles, together with the blood vessels and adipose tissue, are united by the more general epineurium (e) ; the sections of the individual nerve fibers are held in place by the endoneurium ; fat cells near which are the sections of blood vessels (/). directed to the general muscular system traversing the so-called motor trunks, while those impulses which originate in the peripheral endings and are conveyed to the brain travel along the sensory nerves (Fig. 5). venience, into the trunk and the extremities. The trunk consists of the spinal column and the ribs. The spinal column is composed of individual segments of bone called vertebrae, which support the head at one end and ter- FIG. 6. — Points of the horse. 1, muzzle; 2, nostrils; 3, face; 4, eye; 5, forehead ; 6, ear; 7, neck; 8, crest; 9, withers; 10, back; 11, loin; 12, hip; 13, croup; 14, tail; 15, thigh; 16, quarter; 17, gaskiii ; 18, hock; 19, stifle; 20, flank; 21, ribs; 22, tendons; 23, fetlock; 24, pastern ; 25, foot ; 26, heel ; 27, cannon ; 28, knee ; 29, forearm ; 30, chest ; 31, arm ; 32, shoulder ; 33, throttle or throat latch ; A, seat of thoroughpin ; B, curb ; C, bog spavin ; D, bone spavin ; E, splint ; F, wind puff ; G, capped elbow ; H, poll evil. minate, with a marked diminution in size, in the tail at the other. Its course may be divided into regions, the cervical or neck, the thoracic or chest, the lumbar or loin, the sacral or coupling, and the coccygeal or tail. The ribs spring from the thoracic vertebrae and are attached, the anterior directly, the posterior indirectly, to the sternum or breast bone, which constitutes the region of the brisket in ruminants. The ribs inclose the thorax or chest cavity and a part of the abdominal cavity. Superiorly upright spines are developed from the thoracic vertebrae, which give form to the withers or chine (Fig. 6). 12. The foreleg. — The legs or extremities consist of columns, too, each divided into regions. The fore leg is composed of a scapula or shoulder blade, humerus or arm, radius and ulna or forearm, carpus or knee, metacarpus or cannon, the first and second phalanges which constitute the pastern, the latter more particularly the coronet, and the pedal, coffin, or foot-bone. 13. The hind leg. — The hind leg includes the pelvis or hip, by means of which the coupling between the spinal column and the hind leg is made and which also forms the pelvic girdle inclosing the pelvic cavity through which the foetus has to pass in the female, the femur or thigh, the patella or knee, the tibia and fibula or lower thigh, the tarsus or hock, the metatarsus or cannon, the remainder of the leg being a duplication of the anterior extremity. 14. The foot. — The region below the knees and hocks is anatomically considered as the foot proper, the appropriateness of which is shown by a study of the analogous parts in the biped and the intervening stages in the rabbit and the cat. 16. The joints. — The legs constitute supporting columns while at rest, but the extremities of the individual bones, opposed to each other in the columns, are furnished with articular or joint surfaces by means of which one bone moves on the other. By the operation of the joints the columns are broken, the legs alternately flexed or extended, and locomotion is thus accomplished. The joint surfaces are maintained in position by the joint capsule and lubricated by the synovia secreted by it. 16. The muscular system. — The skeletal muscular system is composed of the striated, voluntary variety of muscle tissue. Some individual muscles are long and thin, some short and thick, and others broad and flat. They are arranged mostly in groups of those having similar action, and may be in two or more superposed layers. While the primary function of the muscles is to operate the bones, they serve a secondary purpose in furnishing, as it were, the skeleton, giving form to what would otherwise be but a framework. This is much more marked in some parts than in others. The head, for instance, is but little altered in form or proportions from those of the skull, while all but the column of the neck is muscle, giving it a much better outline than it has in the skeleton ; the form of the withers of the horse is but slightly altered by the muscles of that region, while the croup is made up of such a mass of muscle as to completely change the skeletal outline of that part. 17. The structure and arrangement of individual muscles. — Each muscle has, in its relation with the bones, an origin where the fibers are attached directly to a considerable area of bone surface, and an insertion which is usually accomplished by means of a tendon into which the muscle fibers are continued. The tendon may have more length than the muscle itself, transmitting the power of the muscle a considerable distance before it is finally inserted. The extensors and flexors of the foot, for instance, terminate their muscular portions above the knee, the tendon continuing throughout the entire length of the cannon and the pastern before being inserted. The origin of the muscle serves as the fixed point toward which the bone on which the muscle has its movable insertion is drawn by its contraction. However, other muscles may fix the point of movable insertion when the action of the muscle is reversed. The long muscle concerned with knee action in the horse is an example in point. It has its origin at the side of the head and upper part of the neck and is inserted on the humerus of the arm. With the fixed point above, its contraction elevates and carries forward the arm and with it the leg, but with the leg fixed as in the standing position, its contraction may serve to incline the head and neck to one side. 18. Muscular action. — Each muscle has a definite action, depending upon its position with relation to the joint and the nature of the joint surface itself. Hinge joints have their articular surfaces so arranged as to prevent motion in but one plane, as the elbow or hock joints, while others, as the ball and socket joints of the shoulder and hip, are capable of considerable freedom of motion, even to the extent of rotation. The action of a muscle is to flex or close the angle of a joint, when it is situated in the angle and behind the joint ; to extend when in front of the joint or over the summit of the angle; to abduct or adduct when on the side of the joint away from or toward the median plane of the body ; to rotate if so arranged as to cross from one side to the other in its course. AH muscles are not equally employed. The class of animals and the particular use to which each is put have much to do in determining which muscles are most fre- quently called into requisition. The delicate texture of the so-called tenderloin or fillet of beef is due to its being derived from a group of muscles, the chief use of which is in rearing, and since the unsexed bovine rarely rears, these muscles are so seldom called into play as to leave them practically undeveloped, and therefore very tender. mences the digestion of some of the starches. This is continued after the food is swallowed into the stomach. Here also the gastric juices, with their enzymes, and the hydrochloric acid, continue the conversion of the raw materials of nutrition presented in the food into forms in which they may be assimilated into the blood stream and become available to the tissues and to such secreting organs as the udder. Digestion is completed in the small intestine, where the pancreatic juice and the bile finish the conversion of the starches into soluble sugars and split the fats into fatty acids and glycerin, respectively. 21. Assimilation. — Assimilation takes place chiefly from the small intestine after digestion has been accomplished (Fig. 7), although some of the more indigestible constituents of the ration, as the fiber, undergo a special FIG. 8. — Side view of internal organs of mare. 1, scapula ; 2, humerus ; 3, ulna ; 4, radius ; 5, ribs ; 6, vertebral column ; 7, ilium ; 8, pubis ; 9, ischium ; 10, femur; 11, tibia; a, heart; b, pulmonary artery; c, aorta ; d, stomach ; e, liver ; /, cut edge of diaphragm ; gg, hh, large colon ; i, small intestine ; k, kidney ; m, small colon ; n, uterus ; o, rectum ; p, vagina ; r, urocyst or bladder ; s, anus ; t, vulva. fermentative disintegration in the large intestine, the digestible portion being assimilated from there. In ruminants the food is bolted and passed immediately to the rumen or paunch, where the fiber undergoes some fermentative changes, but it is later regurgitated to the mouth to be masticated at leisure after the supply has been secured. This is the familiar rumination or chewing of the cud, the cud being simply a mass of food which has been swallowed once then passed back to the mouth from the paunch. It is eventually swallowed to undergo digestion and assimilation in the regular way, and to be replaced in the mouth, repeatedly, by other portions until the entire contents of the paunch have been disposed of in this way. The pig is unlike either the horse (Fig. 8) or the ruminating cattle and sheep, which are strictly herbivorous, it being omnivorous, eating both vegetable and animal matter. It is also monogastric, having but one stomach like the horse, although it has much less capacity of large intestine, and is therefore much less capable of digesting a bulky ration than the horse. 22. Circulation. — The blood stream serves as a transit system, through which the digested nutrient material is conveyed to the tissues and organs to be used for their repair and upbuilding in growth ; to be stored up as a reserve fund of energy, as in the case of accumulated fat ; to furnish the essentials for glandular secretion, as in the case of the udder ; or to be utilized immediately, as energy, in the maintenance of body temperature or functional activity in the performance of work. Digestion completed, it remains for the circulatory system to accomplish the assimilation and distribution of the digested food constituents. The circulatory system consists of the heart, which serves as a pump ; arteries, which carry the blood, after having been aerated in the lungs and returned to the* left side of the heart, to the tissues ; and the veins, which return the vitiated blood to the right side of the heart and from thence to the lungs, where the waste products, collected from the tissues, are discharged as carbon dioxide and its red cells are reloaded with a fresh supply of oxygen. In addition to the blood the lymph is circulated through the walls except in the main vessels. 23. Nerve control. — The general function of the nervous system is to exert control over the functions of the other systems, coordinating all movement and regulating all vital processes. The strength and resourcefulness with which this function is exerted is expressed as nerve force, and is usually most marked in the highest bred individuals. Nervousness is no indication of nerve force. The whole nervous organization is comparable to a telegraph system, in which the central station receives reports and proceeds to act upon them in communicating instructions, for execution, to other parts, usually remote. Nerve impulses may be sensory or motor, and motor impulses may be voluntary or involuntary, depending upon the character of the function involved. For instance, the horse receives a certain pressure from the bit representing an idea in the mind of his rider or driver ; the sensory impulse is conveyed to the brain of the horse, from which is sent out the motor impulse which results in the execution of the idea. REPRODUCTION 24. Impregnation. — Copulation is the physical act by means of which the male germ cell, or spermatozoon, is conveyed to the genital tract of the female, there to meet the female cell, or ovum, recently discharged from the ovary. Any prospective breeding animal must be capable of it. The female will only submit to the male during the period of osstrum, or heat, at which time a Graffian follicle in the ovary is maturing and a ripe ovum is liberated. Conception takes place in either the body or the horns of the uterus (Fig. 9) , depending upon the species, and its sequent appearance of oestrum. 25. Gestation. — The duration of gestation is usually correlated with the size and longevity of the species, being three weeks in the case of the mouse and twenty-two FIG. 9. — Generative organs of the mare, a, right ovary ; 6, right oviduct ; c, right uterine horn ; d, left uterine horn ; e, body of the uterus ; e\, vaginal part of uterus ; €2, mouth of uterus ; /, broad ligament ; /i, suspensory ligament of the ovary ; ft, round ligament ; g, vagina; h, vulva; i, vulvar cavity; i\, posteri or commissure: iz, anterior commissure ; k, muscle constrictor cunni ; TO, corpus cavernosum vestibule ; n, abdominal wall ; o, left kidney ; p, left ureter ; r, bladder ; s, urethra ; t, rectum ; u, anus ; v, external sphincter muscle of anus ; w, point where the levator ani muscle passes under the external sphincter ; x, levator ani muscle ; y, longitudinal fibers of the rectum ; y\, posterior band of fibers ; z, muscle constrictor vestibule; 1, utero-ovarian artery; li, branch to the ovary; h, branch to the horn of the uterus ; 2, external uterine artery ; 3, umbilical artery ; 4 and 5, sections through pelvic bone. months in the case of the elephant. There is established following conception, and through the medium of a special development of the walls of the pregnant uterus and of the membranes enveloping the embryo, a temporary circulatory system, by means of which the blood of the dam is passed into the foetal circulation, through the arteries of the umbilical or navel cord and back through the veins of the same structure into the general venous circulation of the dam, to begin another cycle. By this means the foetus is nourished until after birth, when the establishment of respiration and digestion enables him to aerate his own blood and nourish his own tissues. All connection with his mother is cut off with the severing of the cord, which takes place soon after birth. general relaxation of the ligaments which unite the bones FIG. 10. — Pelvis of the mare, showing the dimensions of the pelvic girdle through which the foetus passes in delivery. A, coupling; B, point of the hip ; C, hip joint ; D, point of the buttocks. constituting the pelvic girdle (Fig. 10) , through which the f cetuo must pass, and the soft structures of the pelvic and perineal regions, followed by labor. Normally the foetus is presented head first, with the chin resting on the extended fore legs in such a way as to form a conical protrusion. This helps in the dilation of the parts involved as the contractions of labor gradually cause the expulsion of the foetus. Not only do the structures of the dam favor this expulsion by their relaxation, but the suppleness and flexibility of the foetus itself materially assists. The head, at this age, is capable of considerable compression and alteration in form to accommodate itself to the restricted passage through which it is forced, while the chest may have its vertical dimension flattened by the bending backward of the spinous processes of the thoracic vertebrae, to which this dimension of the chest is largely due. In the case of multiple 'births, as in the sow, considerable time may elapse, with apparently complete cessation of labor, between the expulsion of each foetus. 27. Lactation. — There is naturally a distinct correlation between reproduction and lactation. As pregnancy advances lactation diminishes, if the female is milking at the time, accompanied by a corresponding increase in weight due to the deposition of fat, in addition to the growth of the foetus. Some females cannot become pregnant while suckling young. There is usually a complete cessation of lactation for a period prior to parturition, although some cows will milk persistently for years and can hardly be dried off, though calving regularly. With the approach of parturition the udder manifests a return of functional activity, " springing," as we say, indicating the increase in size and fullness of form most marked in females pregnant for the first time. Such udders finally secrete a characteristic waxy material, and finally milk, a few days or hours before parturition. After the birth of the foetus, the expulsion of the membranes constituting the afterbirth and the ultimate contraction of the uterus, the great volume of blood supply furnished the uterus and foetus is diverted to the mammary apparatus, stimulating it to the maximum of functional capacity, as noted in the fresh cow. The first material secreted by the udder differs both physically and chemically from milk, being thick and yellowish in appearance and possessed of special purgative properties designed to remove the foecal matter, meconium, that has accumulated during foetal development, as the first operation of the new-born digestive apparatus. PATHOLOGY 28. Abnormal structure impairs function. — The relation between structure and function is intimate and reciprocal. Functional limitations are determined by the structure, while the development of the structure itself is, in a measure, responsive to the activity of its function. Carrying one's arm in a sling continuously will cause such complete atrophy or wasting of the part as to seriously impair its usefulness, while the heart of the athlete undergoes hypertrophy, or an over-development, in an effort to meet the excessive demands made upon it. The removal of one kidney may induce a compensatory hypertrophy of the other one. An active secreting mammary gland is " dried off " by arresting its functional stimulus, the milking process, while the rudimentary gland of the male, even, may be rendered capable of some functional activity by persistent stimulation. It is obvious, therefore, that but a slight structural defect may seriously impair the functional capacity of the part • or the individual. It is not sufficient simply to detect the presence of an existing defect or abnormality ; its true significance, in interfering with the function of the part, must be foretold. DEFINITION AND PROCEDURE JUDGING is not an exact science in which determinations can be made with mathematical precision, but results are more or less approximate, depending upon the accuracy with which observations are made and the correctness of the judgment with which decisions are reached. Discrepancies may be due either to inaccuracy in observation, to error in judgment or to both. 29. Judging. — Judging consists of making a thorough analysis of each individual, then measuring them to a standard — the ideal. Four steps are involved. 30. Information. — First, information. In order to be consistent a judge must have a definite notion of what constitutes merit. Full information, therefore, as to individual excellence, market demand, and breed requirements is essential to insure selection to the correct ideal or measurement to an accepted standard. 31. Observation. — Second, observation. The study of animal form requires the keenest powers of observation to be exercised with greatest accuracy. The possession of an instrument does not necessarily insure proficiency in its use ; one may have acquired a definite mind picture of what he seeks yet fail to recognize it when it is seen. Observation is the application of the standard, the actual measurement of merit by means of which a close estimate or a careful analysis may be made. 32. Comparison. — Third, comparison. It is one thing to buy a carload of animals that must all conform to specified requirements, but quite another matter to pick out the first, second, third and fourth best from a car lot offering. It may be simple enough to make analyses and give descriptions of any number of individuals, noting carefully all commendable features as well as defects, yet most difficult to balance a superior head and neck, but low back of one, against the good back and deficient hindquarters of another. The first described is observation; the second, comparison. The judge must do this before he can ascertain, in the aggregate, the relative merits of the different individuals under his consideration and before he can arrive at a final conclusion as to their placing in competition. 33. Conclusion. — Fourth, conclusion. The last step consists in weighing the evidence collected by the two preceding steps and returning a verdict thereon. When a decision is once made it is most gratifying to an exhibitor or seller, as well as most assuring to the judge, if he is able to give full reasons for having made the awards as he has done. 34. System in judging. — The most comprehensive judging is secured by a systematic procedure. It is true many good judges do their work intuitively, but even intuition may be systematized to advantage. Judging must be done with a reasonable degree of dispatch, although time often serves to clear up certain points which at first seem obscure. The judge is, therefore, justified in using some deliberation, although his observations should be so conducted as to enable him to form a most definite and accurate impression in the least time. normal conditions, are most likely to be correct. The judge should see to it, therefore, that the first view he takes will be fair to both the animal and himself. Experienced showmen and salesmen appreciate the importance of this first view in establishing favor for or prejudice against the animal they are exhibiting. If they have an animal possessed of real merit, they endeavor to enter the ring at such a time, usually either first or last, or to take such a position as will insure the judge's having one good, impressive look at the particular individual in which their interest is centered. This accomplished, they feel assured of careful consideration, in turn, with no danger of being smothered in a large class, as sometimes happens. Given an inferior animal, however, the attendant makes his entry as inconspicuous as possible among the others in order to avoid undue exposure of his exhibit's worthlessness, in the hope of being left in a higher position than he truly deserves. 36. Conditions under which shown. — In order not to be misled in his observations the judge should understand and allow for the conditions under which the animals are shown. It seems to be considered legitimate to take advantage of everything that rightfully belongs to an animal so long as there is no real misrepresentation. It is perfectly proper to pose an individual for inspection. That is simply putting his best, foot forward, as it were, and it enables the judge to better see him as he really is. Standing a horse uphill, for instance, accentuates his good points, yet there is no deception attempted, and to stand him downhill would be manifestly unfair both to the horse and to the judge. camping is justifiable on the ground that it serves to keep a horse on all four feet, and is a protection to any one passing about him, since the horse must assume a natural standing position before he is able to kick or strike. Overdone, camping is unsightly and may be resorted to for the purpose of making a low back or bent hocks appear straight. Cattle and sheep should be stood up on their feet to enable the judge to get a good look at them, but they may be held in such a manner as to materially alter their lines, handling qualities in the former and conformation in the latter. Such trickery can hardly be accepted as proper, neither can the holding up of a hog's back by keeping down his nose in quest of corn in the litter of the show ring, after having taught him by experience to expect it there. SIDERED IN JUDGING 38. General appearance is determined by all those features which may be observed at a casual glance, and usually includes a number of the individual features hereafter enumerated. 39. Height or stature is a consideration in horses only, as a rule, in which it is measured at the highest point of the withers and is expressed in hands, four inches to the hand. Fractions of a hand are given in inches most commonly, as fifteen hands, two inches, or 15-2, when the height is sixty-two inches. 40. Weight, as registered by the scales, is not stated exactly, a unit of twenty-five pounds being the division usually allowed in the case of horses and cattle on account of possible variations of less amount being due to feeding and watering. scale. 42. Style is especially marked in horses, constituting a most important feature of show, but greatly enhancing the appearance of any class of animals ; it may be manifested by cattle, sheep and hogs as well as horses. 43. Symmetry is the result of the balancing of parts in such proportions as to give an even, uniform, harmonious appearance of the whole. It is as though the assembled than formed independently. 44. Type is the sum total of those features the possession of which enables an individual to meet the definite requirements of special service or production. It is manifested by that form and contour which mark the distinction between an individual that is blocky from one that is angular, for instance. 45. Conformation. — Type has to do with the general structure resulting from the assembling of all component parts, while conformation involves the individual structure of each of these parts as a unit. The strength of a chain is measured by the strength of its weakest link, therefore defection in one part may offset an otherwise perfect structure. However, some parts, as the hock joint of a horse or the loin of a steer, for instance, have greater relative importance than others ; thus a deficiency in them would have more influence on the serviceability of the whole than a corresponding inferiority of structure in some other part. Appreciation of conformation, therefore, consists not alone in the detection of points, both superior and inferior, but in attaching to each due significance as bearing on the general excellence of the animal or interference with its adaptability for the purpose to which it is to be put. 46. Quality is that which pertains to the character of the individual unit of structure, the cell, and the proportion of them to the intercellular substance by which they are united in the organization of tissue. Quality is manifested in the texture of the tissue such as the hide, hair and bone especially, and by the general finish and refinement of the animal structure as a whole. Quality establishes the grade of the animal structure and its products. breeding. 47. Substance refers to the size and number of the individual units of structure and the gross amount of the tissue into which they are organized. It is manifested by the scale of the animal in general and the amount of any one tissue in particular, such as bone. Quality and substance are not correlated, but more or less of each is essential, depending upon the type of the animal. 48. Condition. — An animal is in condition when in that state most favorable to the performance or production peculiar to his class or type. Condition is the result of fitting, a process involving a balance between feed and work during which the animal accumulates or reduces fat until the optimum degree of obesity is attained. In block animals and even in market draft horses the maximum degree of fatness is desired, and its accumulation is favored by most liberal feeding of a wide, fat-forming ration and frequently almost complete prohibition of exercise, while the race horse and dairy cow are capable of their best performance when their normal amount of fat is reduced to the minimum by a course of exercise of their respective functions which is offset only by a carefully guarded narrow ration. 49. Constitution represents such capacity of the vital functions, respiration, circulation and digestion especially, as will insure longevity, fecundity and maximum efficiency in performance or production. It is indicated chiefly by a large, open nostril, the spring and length of the rib, both fore and back, a sleek appearance of coat, an expregsion of vigor in the eye and countenance and a general appearance of thrift about the animal, although the latter evidences of constitution may all be temporarily impaired breeding, feeding and working animals. 60. Temperament is the term by which the nature of the nerve control over the functions in general is designated. There are two classes of temperaments, first, the nervous, in which the nervous mechanism operates in such a way as to cause the animal to manifest an active, snappy manner, keenly alive to what is going on about him, possessing unusual nerve force and even nervousness; second, the lymphatic or phlegmatic, in which the nerve factor is apparently less acute, movements being executed more slowly, although preferably not in a dull, sluggish manner, and there is a marked tendency to feed and rest well with little inclination toward much activity or concern. Temperament is a constitutional, not a mental, feature. 51. Disposition is the mental attitude of an animal, independent of intelligence, and reflected by his cheerful, willing, obedient responsiveness, or sour, crabbed rebellion. Disposition is naturally of most importance in the horse and dairy cow, animals in most intimate association with the husbandman. culinity is evidenced by an extraordinary development of the forehand or forequarters, the crest, the strength of the face line, the hardness of feature, burliness, and the bold, domineering manner, suggestive of the impressive sire. Femininity, on the other hand, is expressed by the absence of special development in the fore end, a lightness of shoulder and neck, fineness of feature, and a sweet, matronly expression and appearance. There is a correlation between evidence of masculinity on the one hand and FEATURES OF ANIMAL FORM 35 both virility and prepotency in the male, on the other; while a female which lacks femininity may not only fail to breed regularly but an absolutely staggy appearance, associated as it is, usually, with more or less continuous O3strum and inability to conceive, has been due in some cases to the existence of hermaphrodism, in which there is a more or less imperfect development of the essential organs of both sexes in the same individual. The importance of sex character is confined, of course, to breeding males and females, although stallions are sometimes favored for show purposes on account of the boldness which characterizes their performance. 63. Breed character or type. — A breed is a group of individuals possessing distinctive characters not common to other members of the same species and so firmly fixed as to be uniformly transmitted. Breed type is the sum total of those distinctive characteristics by which the breed group may be differentiated, as size, form, peculiarities of conformation, color and markings, shape of the head, and horns, if any, with the especial and distinctive features of performance or production. It is with these distinctive characters that the judge is concerned in the judging of breeding classes or the selection of breeding stock. Utility, however, should be the basis of distinction. In order to maintain breed identity, all distinguishing features should receive consideration, but those of a utility character, which relate to performance or production, should be stressed more than such matters as color, markings, or the shape of ear, horn or snout. It has been stated that the best representatives of each of the draft horse breeds, for instance, should approach very closely to the same general type. It is most essential that they all be primarily of draft type, but if the only difference between a Percheron and a Belgian is to be color, and not even color can be depended upon to distinguish a Clydesdale from a Shire, what is the use of attempting to establish-breed identities? 64. Factors determining breed characters. — As a matter of fact, these distinctive characters of breeds are the result of either or all of those agencies that have been operative during the formative period of the breeds. They are the foundation stock or the origin in blood, the environment by which these hereditary endowments have been molded, or the geographic origin, and the ideal or purpose to which selection has been made. The last is, of course, the final and determining factor in every case, and may be sufficient of itself to account for the differential features of two breeds. The judge is concerned with the origin, history and development of the breeds only in so far as they have been factors in the creation of breed type and character. There is reflected, more or less, in the typical representatives of the different breeds, the three factors which have influenced their development. Since there can be bred on, only such characters as have originally been bred into a breed, there are good economic reasons why these distinctive and useful breed characters should be recognized by the judge and their true significance appreciated. 65. The best breed. — There is scarcely a breed of horses, cattle, sheep or swine that does not possess, by virtue of one or more of these factors, some one character in greater degree than does any other breed, and it is, on this account, better adapted to some particular performance or production. By guarding zealously in our selections these characters, thus retaining the integrity and identity of the breed, we are insuring stock that is much of usefulness. 56. Objectionable breed characters. — Unfortunately not all features by which breeds may be characterized are desirable ones. Some most objectionable characteristics are transmitted with unfailing regularity, and it is as important that they should be recognized and eliminated, so far as is possible, as that the good features should be carefully retained. Fair treatment of all breeds, therefore, requires that these exceptions to the desirable breed character or type shall be noted. 57. Way of going. — The way of going is a definition in itself. It is of principal importance in the horse, although the movements of all classes of animals are taken into account in judging. The particular gait the horse goes, the features of the stride at that gait, the pace or rate at which he moves, the action displayed, and the manner in which he places or sets himself while going are all features of the horse's way of going. In the other classes of live stock it is only necessary to note whether or not the animal goes well upon his toes, with pasterns supported and without cramped hocks as in the case of sheep and swine, or, in such a way as to indicate absence of founder or weakness in hind legs, as well as to exhibit the style and animation desired in breeding and show cattle. 58. Soundness is that condition in which an animal is physically capable of performing the ordinary service of his type or class ; anything that renders him incapable, in any degree, constitutes an unsoundness. Soundness is most commonly considered in connection with horses, but its meaning may be extended to include all classes of live stock. For instance, a cow that has lost one quarter of the udder, a hog that is so badly broken down in the pasterns that he can only get about the feed lot with difficulty, or a bull with only one testicle in his scrotum or so weak in the hocks that he cannot mount a cow, are almost as much incapacitated as is the horse that is lame. 59. Breeding unsoundness. — Any condition which may prevent a male animal from impregnating the female, or the female from delivering a live, normal young, constitutes breeding unsoundness. Furthermore, the possession by a breeding animal of any condition which, transmitted to its offspring, may partially or completely incapacitate it, is also a breeding unsoundness. However, the transmissibility of many of the so-called hereditary unsoundnesses has not been established ; even roaring and moon blindness in horses, the only two things for which stallions are disqualified in France, where the most comprehensive system of inspection is, are now believed to be more frequently the result of preexisting influenza in the one case, and of an enzootic infection in the other, than of hereditary influences. Yet, on the other hand, almost any unsoundness of a male or female may manifest itself in the get with more than casual uniformity, thus proving its transmissible nature. 60. Defective conformation. — Unsoundness, or, more particularly, the defective conformation which predisposes to it, is of considerable importance to the judge of any class of stock, but on account of the more complex nature of the horse's function and the greater variety of conditions by which that function may be impaired, discussion of the subject will be directed, chiefly, to the horse. 61. Unsoundness in horses may be of eyes, wind or limb. Mental defects are usually included under vices. So far as show ring judging goes, the matter of unsoundness is of no concern to the judge himself, it being settled according to rule by the official veterinarian, but one should not be wholly dependent upon the veterinarian for the detection and disposition of ordinary unsoundnesses. There is no difficulty experienced in diagnosing bad eyes if the lens has become opaque or the cornea clouded, yet serious conditions may exist in the eye without any such manifestations. These require the skilled practitioner to identify them. A diseased condition of any standing will result in atrophy or shrinking of the eyeball, just the same as a lame foot gradually becomes smaller. This reduction in size causes the eyeball to occupy less space in the orbit, with the result that it retracts deeper into the head, and the upper lid, not being distended by the eyeball any longer, looses its even curvature and becomes notched with an angle. A widely dilated pupil or one that does not respond promptly to changes in the amount of light admitted, as when the eye is covered with the hand and then quickly exposed again, is suggestive of imperfect vision. 62. Unsoundness of wind includes the so-called roaring and heaves. While roaring may be understood to be any kind of noise made in breathing, technically roaring is made upon inspiration only and is due to the paralysis of one of the cartilages of the larynx, that cartilaginous sound box with which the trachea or windpipe begins. Horses with bullish necks that are thick in the throttle and have a narrow angle between the branches of the lower jaw may make a distinct noise when pulled, especially on a curb bit, due to the compression of the larynx. This noise, like that due to pressure from any other cause, is most noticeable upon expiration and is relieved as soon as the horse is stopped and the head released, while true may even be induced by threatening to strike the horse. Heaves are detected by the violent expiration when the horse is exercised, the short, dry cough, the continual dilation of the nostrils and the double lift in the flank on expiration, the ordinary expulsion of the breath being followed by a second additional effort. 63. , Unsoundness of limb involves the structure of the foot, the bones, especially at the joints, the ligaments and the tendons. Founder (Fig. 12), the previous existence of which, unless promptly overcome, is indicated by the dip in the wall of the toe, the dropping of the sole, the uneven ringlike growth of the horn, and, most important of all, the peculiar going on the heels ; contraction of heels or soles ; cracks and thrush are of the first class. An exostosis is a bony growth, the result of an inflammation in the bone which causes a rapid throwing out of bone cells similar to the formation of " proud flesh " in the soft tissue. Exostoses located at definite points are specifically designated as spavin (Fig. 13), when the hock is involved, ringbone (Fig. 14) high or low, when at the first or second pastern joint, respectively, splint when along the splint bones of the cannon. The seriousness of the exostoses depends upon the extent to which the function of the part is involved. After the acute inflammatory stage has passed the exostosis may merely interfere me- and ringbone are not the essential joints of those parts, and they can, therefore, be dispensed with and cause no serious interference with function. Exostosis is usually a sequel of or accompanies an inflammation of the joint surface, called arthritis, as in spavin, although it may be independent of the joint, as in sidebone, and, usually, in splint. The lameness due to an arthritis is most marked when the horse is first taken out after a long rest preceded by hard work, and gradually disappears more or less as the horse " warms out of it." The presence of an exostosis is best made out by comparing the corresponding joints or regions in the two legs. Many normal but rough joints may be suspected until it is determined that both hocks or all four pastern joints, as the case may be, are symmetrical. Any deviation in the normal outline of the joint or bone that is not duplicated should be carefully investigated. This rule does not always hold, however, as two spavins or more than one ringbone may manifest themselves at the same time. The sidebone may present no enlargement or alteration in form whatever, the lateral cartilage, normally elastic and springing upon pres- result of the ossification. Ligaments are differentiated from tendons by the fact that they unite bone to bone, while the tendon unites muscle to bone. The ligaments most likely to become the seat of an unsoundness are the great suspensory ligament, which sustains the fetlock joint, on the same principle as a truss under a box car, the ligamentous structure at the back of the fetlock joint with which the suspensory ligament is related and the curb FlG 16 _ Lt ligament at the back of the hock (Fig. 15) . showing capped Rupture of this suspensory ligament is the " breaking down " of the race horse. The tendons most commonly involved are the flexor tendons of the foreleg. If contracted, they cause cocked ankles and sprung knees, while if some of their fibers have become ruptured and repaired by low grade connective or scar tissue they are said to be " bowed," a common condition in race horses. Lameness due to sprained ligaments and tendons is usually aggravated by moving the horse instead of being relieved, to some extent, as it is if due to inflammation of the joints. 64. Age. — Its determination in those classes of live stock the majority of whose lives are terminated after a short period of a few years, as beef cattle, hogs and sheep, is a comparatively simple matter, but in the case of the horse, which not only lives to a much greater age, but is valued largely on the age basis, and consequently invites frequent attempts at deception, the indications are more complex and difficult of determination. In the former group the order of eruption of the teeth is the primary consideration, wear being noted only in those breeding animals of advanced age, while eruption in the horse can only be relied upon until he is fairly mature, after which wear is responsible for the changes which mark the ages. Distinction between the milk or deciduous teeth, which are shed, and the permanent teeth, upon the eruption of which so much depends, involves their size, shape, and color (Fig. 17). In all animals the permanent teeth are larger, less conical in shape, have a much deeper root, a wider base and a thicker coat of enamel, the surface of which is usually ridged per- tooth, pendicularly, and yellow instead of white. corners are not yet level. Two years. — The pinchers and the intermediates are pushed free from their gums at their base, indicating that the permanent teeth are crowding them (Fig. 19) . Four years. — At three and one half the permanent intermediates come through and at four they are leveled and wearing. At this age the corner milk teeth manifest the approach of the permanent corners (Figs. 21 and 22). Five years. — At four and a half the corners are shed, the permanent corners appear and at five there is the socalled full mouth, all permanent incisors being level and in wear (Figs. 23 and 24). wear out, the notch on the upper corner appears and the incisive arch or the angle made by the teeth as they meet becomes more acute (Figs. 27 and 28). •Eight years. — The cups wear out of the corners, the pinchers and intermediate teeth become oval in shape, and show the dental star, upon their table (Figs. 29 and 30) . FIG. 33. — Shows the wear of an incisor tooth at the ages of three, four five, six, nine and twenty years, and why the cups, or marks, disappear as age advances. The lower nippers wear away about oneeighth of an inch each year. The upper incisors wear away more slowly. Nine years. — The notch on the upper corners may have disappeared, the pinchers are round, and the corner teeth oval. The upper pinchers show wear, and the angle of the incisive arch is more acute. Ten years. — The cups of the upper pinchers are worn out and the angle at which the teeth meet has become so acute as to necessitate raising the horse's head in order to look by the upper teeth to view the lower pinchers. Eleven years. — The tables of the intermediate uppers are worn away and the corners show wear. The lower corners have become round and the obliquity of the jaws is still greater. Twelve years. — The tables of all the upper teeth are worn, those of the lowers are distinctly round and the angle of the jaw is increased. Beyond this age the indications of the mouth are based upon the increasing obliquity of the jaws (Fig. 31), giving a more acute angle of incidence of the teeth, the increasing changes in the size and shape of all the teeth (Fig. 32), due to their being worn closer to the roots and the narrowing and flattening of the lower and upper jaws, respectively, the result of the tissues closing in and crowding the roots of the teeth down so as to keep the worn tables in contact (Figs. 33 and 34). 66. Bishoping is quite commonly practiced on the mouths of second-hand horses that are offered for sale. It consists in burning into the table of the tooth a cup to replace the one which has been worn out with age. Mouths are usually bishoped to resemble the appearance of the cups at 6 or 7 years of age. The made-over mouth can be detected by the fact that the appearance of the cups is not in accord with the angle or shape of the teeth. Unless skillfully done the burned cup itself can be recognized, and there will not be the ring of enamel which surrounds the cup of the normal tooth. 67. Determination of the age of cattle. — The general size, shape and growth of the cattle as well as the appearance of their horns is usually evidence enough to determine their age. It is only in case of disputes, as over the classification of show cattle, that the teeth are called into requisition. The bovine teeth present some special features. Incisors are not firmly set in the jaw cavity as in the horse, but are imbedded in cartilage in such a way as to permit of considerable movement. This is necessary on account of the fact that the teeth are not opposed by others in the upper jaw, but rather by a peculiar development of the gum to form a cushion against which the feed is crushed by the teeth of the lower jaw. Furthermore, the tissues of the jaw do not close down upon the roots of the teeth crowding them forward as their tables wear away, although this wear begins before the tooth is fully developed. At birth. — The calf usually has four incisors at birth, although he may have none, and the third pair appears about the tenth day, the last or corner pair anywhere from the seventh to the thirtieth day. These teeth are not leveled, however, until the fifth or sixth month. The pinchers are worn level at ten months. One year. — The first intermediate pair of milk teeth are leveled at one year, the second pair at fifteen months and the corners at eighteen to twenty months, at which time the permanent pinchers appear. leveled and the second pair is much worn. Eight years. — The tables of all the teeth are leveled and the pinchers begin to show a hollow which corresponds to the prominence of the cushion of the upper jaw. This concavity appears in the first intermediates at nine and in the second at ten. the horse. 68. Telling the age by the horns. — The growth of the horn is a fairly reliable indication of the age in cattle. The first distinct ring appears at three years, and each succeeding year adds its ring so that two should be added to the count of the rings to determine the age. 69. Determination of the age of sheep. — The eruption of the permanent pinchers takes place in the sheep at from twelve to fifteen months of age and the succeeding two pairs of intermediates and corners follow approximately one year apart. At least this is the basis upon which the age of sheep is usually reckoned, although the exact time of the eruption of the teeth involves fractions of years and months. Age is often expressed by two-tooth or four-tooth, as one pair of permanent incisors has appeared in one year, two pairs in two years. 70. Determination of the age of hogs. — Little thought is given to the determination of the hog's age by his teeth. It is difficult, in the first place, to observe his mouth, and in the second place the indications are subject to much irregularity. 71. Early maturity insures attaining full, normal growth and development at the earliest age. Animals maybe considered to have a definite period to develop in, rather than a definite degree of development to attain in unlimited time. If one does not make steady growth during this growing period, it will be deficient in development when growth ceases. Early maturity is indicated in any class of stock by weight for age and general evidence of growthiness and proximity to final development. 72. Color has both a market and a breed significance. Certain colors enhance while others detract from the value or usefulness of certain animals. The color and color markings are the most striking features of breed type in some instances, as in the Hereford cattle. Color is a most convenient aid to an accurate description of an animal, a most important means of establishing identity, as in the case of pedigree registration. For this purpose the various shades of the individual colors, and the exact location, extent and outline of the white markings should be accurately noted. THE LAW OF CORRELATION The law of correlation is one of the principles upon which the practice of judging is based — the correlation of form or structure and function, and the correlation of parts, one to the other. 74. The correlation of form and function. — Actual determination of functional capacity, as in the horse race or pulling contest, the dairy or slaughter test, affords the most accurate and, in some instances, the only means of judging the relative merits of individuals. No one would consider settling a matter of speed supremacy in the show ring, for instance, but would send the contestants away in a race. It even happens that the awarding of the ribbons in dairy and beef cattle rings may be somewhat reversed when the same classes are subjected to the real test in the dairy or the abattoir. However, it is not always practicable to await the results of a try-out of relative merits in performance or production; the judge must estimate functional possibilities from an analysis of structure and, if correct standards of measuring structure are employed, reasonably accurate results may be expected. The more complicated the function, of course, the greater the factor of possible error. Function is the end, structure the means. Function has its limitations. In the case of the finished block animal, it consists simply of being a carcass of beef, mutton or pork, while in the case of the feeder, function implies doing something, and with the horse and the dairy cow doing may become a still more complicated performance. It is manifestly a simpler proposition to determine how a hog will cut up or a steer hang up by seeing them on foot than to estimate, from an inspection, how many pounds of milk or fat a dairy cow will produce in a year or how fast a horse can trot or run. As a matter of fact, the actual test is the only practical means of making the latter determination, although even here an approximate idea of functional capacity can be had from the study of form. The novice is impressed with the rapidity with which the experienced judge will make his analysis of animal form. The detailed scoring of an animal, even by an expert, will require much more time than may be consumed in forming a very accurate notion of the sum total of the individual's good and bad points. " Practice makes perfect," and the practiced eye can discern more quickly, but, in addition, consideration of the law of correlation enables the expert judge to cut corners, as it were. 75. The correlation of parts. — One part is an index to other parts with which it is correlated. Thus the buyer of feeder cattle seeks out broad, flat backs as he looks down on them from his pony, or short, broad heads if they are faced about to him in the pens. A head of these dimensions will be found only on a low set, broad, deep and usually a thick-fleshed steer, while a long, narrow head indicates the reverse. As a rule, longitudinal dimensions of all parts are alike long or short and are inversely related to transverse and perpendicular dimensions. Hence a long-legged animal is long all over, head, neck and back, while inversely narrow and short ribbed. It is as essential to know what are not correlated as what are ; quality and substance, milk and beef, power and speed are opposed to each other by this same law. THE MEANS OF MAKING OBSERVATIONS 76. The eye and the hand. — The eye and the hand are the means relied upon for making determinations of animal form and features; the latter usually being employed to supplement the eye or verify what has been seen. The relative importance of the eye and the hand for this purpose will depend upon the sort of stock judged. The eye is almost exclusively depended upon in the judging of hogs, even the firmness of the flesh being ascertained by the lay of the hair. Next in order come horses, it being necessary only to run the hand over the tendons and joints to note their texture and detect possible unsoundness and to feel condition on the rib. Cattle are regularly handled : those of the dairy type to get the thickness, pliability, secretions and looseness of the hide, the amount and texture of the hair, the texture of the udder and the openness of the chine ; while beef cattle are handled to determine, in addition to the features of the hide and hair already enumerated, the thickness, consistence and evenness of the covering of flesh. Sheep have their form so obscured by the fleece and the fleece is often so cleverly trimmed as to require most careful handling in order to become informed of the details of mutton form and conformation. Handling is also necessary in the examination of the fleece. In fact, in the case of the sheep the hand is case of the hog. 77. Method of handling. — In handling it should be remembered that the tips of the fingers are most sensitive to the touch. The hides of cattle are rolled in the flat of the hand or between the fingers and thumb. The hide is most easily picked up over the back rib, the animal's head, meantime being directed forward, as turning to either side loosens the skin very noticeably on that side and causes a corresponding tightness on the other. Depth of covering in cattle and sheep is shown along the spinal column of the back and loin and over the top and side of the shoulder, regions in which the bone is likely to be most conspicuous. Sheep are handled with the flat hand, the fingers kept tight together, care being taken not to muss the fleece by turning down the staple. The fleece is parted for examination at three places, over the heart where it is finest, on the lower outside of the thigh where it is coarsest, and at mid-rib where an average of its quality will be found. A natural seam is selected and opened by the backs of the two hands, which are afterward reversed in such a manner as to press the fleece back with the palms, exposing the staple for its full depth, and the skin. 78. Method of observing. — The study of the horse's way of going is made by having him moved away from, toward, and by, the observer. By lining up the eye with the direction in which the horse is moving the directness of the stride is apparent whether going or coming, as are also the height of the stride, hind and front, and the working of stifles and shoulders. Viewed from the side, as he passes by, the length, height, spring, balance and regularity of the stride can be noted. Some definite system of making observations should be followed in order that each look may be made to count, and only one look be. necessary ; if the views are taken in logical order from head to tail, for instance, there is not only less likelihood of certain points being overlooked, but the impression formed of the animal in toto will be more complete and accurate. 79. Inspection. — Observations must be both general and particular. The first step in the inspection of an animal should be to take a general survey of the tout ensemble from such a distance as to bring the subject entirely within one's field of vision, and thus permitting a consideration of its size, general appearance, lines, proportions and the symmetry of its parts. The particular observation should follow and include a minute examination, in order, of every detail, from close range. The order of this examination may be : face the animal from in front, noting the bigger things first, i.e. width, height, size and carriage of head, then in detail, the proportions of the head, the expression of the countenance and the features contributing thereto, eyes, ears, forehead, face, nostrils and lips; then the direction of the forelegs, whether normal or showing deviations and what deviations, if any, with the conformation of the forelegs and the feet. Pass to the side position and consider in profile such general features as top and under lines, the carriage of the head, and setting of the body on the legs ; then in detail, the head in profile, the setting of the head on the neck, the length, shape and carriage of the neck, the blending of the neck with the shoulders, the direction and conformation of the forelegs viewed from the side, the back, rib, heart girth, loin, flank, croup or rump, tail, thighs and finally the direction and conformation of the hind legs and feet. From the rear view first, in general, the width and contour, then, in detail, the hips, stifles, thighs, lower thighs, and the direction and conformation of the hind legs and feet. Finally, inspect the other side, in order to determine whether or not the animal is symmetrical. PRACTICE JUDGING A THOROUGH study of animal form with full appreciation of its bearing on function as concerned in economic production is fundamental to actual judging. Judging implies comparison and competition, since selection is impossible when only one individual is presented. It requires, first, an analysis of each individual under consideration. Then a comparison of each, in sum total, and finally competitive consideration, the good points of one being arraigned against the good points of another, the defects against defects, until a final and definite conclusion may be drawn as to their relative merits. 80. Analysis of the individual. — A study of the individual should precede any "attempt at comparative or competitive judging. The names, ideal features, and possible defects, with their significance, must be known and detected both in so far as the individual parts are concerned, and in their relation with other parts. Score card practice and demonstrations are most useful in acquiring this information. 81. The score card, in this relation, is not to be considered as a standard of measurement or a numerical expression of merit as in the scoring of cows for advanced registration, but as a word picture or descriptive specification of the ideal animal. For this purpose the detailed, rather than the condensed, score card is most useful, By means of the arrangement into major headings, each of which is divided into sub-headings, the student may become familiar with the individual parts and the regions into which they are grouped, with the names of each. The correct features of each part are specified in a brief description and the relative importance of each part in the animal organism is indicated by the numerical value attached thereto. Those which are most liable to be defective and most detrimental to the usefulness of the animal if defects in them exist are allotted the greatest number of counts. By continued practice with the score card, the student not only acquires a mental impression of the ideal, which eventually enables him to cast the score card aside, but he is also trained in making systematic and accurate observations. parallel to slope of pastern, sole concave, bars strong, frogs large and elastic ; heels wide, full, one third height of toe ; horn dense, smooth, dark color 6 lar line dropped from the point of the shoulder should divide the leg and foot into two lateral halves. Viewed from the side a perpendicular line dropped from the tuberosity of the scapula should pass through the center of the elbow joint and meet the ground at the center of the foot . 4 form, straight, slope of wall parallel to slope of pastern, sole concave, bars strong, frog large, elastic ; heels wide, full, one third height of toe, horn dense, smooth, dark color 4 dicular line dropped from the point of the buttock should divide the leg and foot into lateral halves ; viewed from the side, this same line should touch the point of the hock and meet the ground some little distance back of the heel. A perpendicular line dropped from the hip joint should meet the ground near the center of the foot 4 parallel to slope of pastern, sole concave, bars strong, frog large, elastic, heels wide, full, one third height of toe, horn dense, smooth, dark color 6 lar line dropped from the point of the shoulder should divide the leg and foot into two lateral halves ; viewed from the side, a perpendicular line dropped from the tuberosity of the scapula should pass through the center of the elbow joint and meet the ground at the center of the foot ... 4 uniform, straight, slope of wall parallel to slope of pastern, sole concave, bars strong, frog large and elastic, heels wide, full one third height of toe, horn dense, smooth, dark color 4 ular line dropped from the point of the buttock should divide the leg and foot into lateral halves ; viewed from the side this same line should touch the point of the hock and meet the ground some little distance back of the heel. A perpendicular line dropped from the hip joint should meet the ground near the center of the foot 4 parallel to slope of pastern, sole concave, bars strong, frog large, elastic, heels wide, full, one third height of toe, horn dense, smooth, dark color 6 line dropped from the point of the shoulder should divide the leg and foot into two lateral halves. Viewed from the side, a perpendicular line dropped from the tuberosity of the scapula should pass through the center of the elbow joint and meet the ground at the center of the foot . 4 form, straight, slope of wall parallel to slope of pastern, sole concave, bars strong, frog large and elastic, heels wide, full, one third height of toe, horn dense, smooth, dark color 4 dicular line dropped from the point of the buttock should divide the leg and foot into lateral halves ; viewed from the side this same line should touch the point of the hock and meet the ground some little distance back of the heel. A perpendicular line dropped from the hip joint should meet the ground near the center of the foot 4 parallel to slope of pastern, sole concave, bars strong, frog large, elastic, heels wide, full, one third height of toe, horn dense, smooth, dark color dicular line dropped from the point of the shoulder should divide the leg and foot into two lateral halves; viewed from the side, a perpendicular line dropped from the tuberosity of the scapula form, straight, slope of wall parallel to slope of pastern, sole concave, bars strong, frog large and elastic, heels wide, full, one third height of toe, horn dense, smooth, dark color 4 dicular line dropped from the point of the buttock should divide the leg and foot into lateral halves ; viewed from the side this same line should touch the point of the hock and meet the ground some little distance back of the heel. A perpendicular line dropped from the hip joint should meet the ground near the center of the foot 4 dropped from the point of the shoulder should divide the leg and foot into two lateral halves; viewed from the side, a perpendicular line dropped from the prominence on the side of the shoulder blade should pass through the center of the elbow joint and meet the ground at the center of the foot 4 dropped from the point of the buttock should divide the leg and foot into lateral halves ; viewed from the side, this same line should touch the point of the hock and meet the ground some little distance back of the heel. A perpendicular line dropped from the hip joint should meet the ground near the center of the foot 4 82. Demonstrations may supplement scoring, the subjects being chosen with the view of showing both desirable and undesirable features. Discussion should not be confined to noting defects and criticizing them but should give equal prominence to the good points and commending them. Neither should the subjects of demon- stration be chosen for their excellence, altogether, for it is as essential to know those features of form that are opposed to greatest functional capacity as it is those upon which maximum productiveness depends. Comments and criticisms may be recorded briefly on blank forms having an outline of the animal in question (Figs. 35, 36, 37, 38, 39). This serves the double purpose of directing the student's attention to definite points in the animal form and affording a means of making a concise report of his observations. It does away with the monotonous and confusing figures of the score card which often engage much of the student's time that might be more advantageously spent in studying the merits and demerits of the animals before him. The outline blank may be double faced, one side to be used for criticisms, and the other for indicating the points of excellence. 83. Comparisons. — After score card practice, demonstrations and discussions which perfect the student in analysis, exercises in simple comparison should follow by the introduction of more than one subject. Comparison involves not only measuring the character in question to the standard in the mind's eye but carrying, in the eye, the image of the character of one individual until there can be placed beside it, in the judge's vision, the analogous character of another individual, so that an opportunity for comparison may be afforded. By repeated comparisons the ideal is gradually crystallized in the student's mind, the good points being rendered more conspicuous by being merit. 84. Competitive judging. — Finally, but only after having acquired skillful method, keen perception, and a definite notion of the ideal, the student may be permitted to carry his comparisons a step farther and bring the different comparable characters into actual competition, first covering parts or regions only, as heads and necks, perplexities of " placing " a class of animals before they have acquired the standard to which they are to select or mastered the art of applying it. It is interesting to note, in this connection, the different tactics employed in coaching student teams for judging contests. Some trainers condition their race horses by repeated trials of as great severity as the race itself ; others spend their preliminary seasons in perfecting the gait of their horses, balancing, biting and schooling, at the same time giving them sufficient work to render them physically capable of a more strenuous effort than they are, but rarely, called upon to make in their work outs. of classes which their teams have had an opportunity of placing, notwithstanding that such placing may have been made under wholly unsatisfactory conditions, as when no chance is afforded for subsequent discussion. Such work tends to confuse and render chaotic whatever correct notions the students may have entertained. Others, and usually the more successful ones, spend the time after their team is chosen, which is usually on the basis of competitive judging, in demonstrations and dis- cussions of typical and atypical representatives of the types and breeds, creating thereby a clearer conception of the ideals, more accurate powers of observation, and more logical judgment for making competitive decisions when the crucial time for them arrives. THE INDIVIDUAL IDEALS are the bases upon which animals are judged, and they may concern the individuals, the types and the breeds of horses, cattle, sheep and swine. 86. The horse, Equus caballus. — There is archaBological evidence that the horse served primitive man of the stone age together with the reindeer and the dog, although there is no authentic historical reference to his use prior to the time of Joseph in Egypt, 1715 B.C. While the mare's milk and horse meat have been used in a very limited way, the horse's power and speed have been the attributes most commonly made use of by those who have subjugated and domesticated him. He is more than a simple beast of burden, in which field he was preceded and in some ways excelled by the dog, reindeer, camel, elephant, ox, ass and mule ; he has taken a most important part in warfare and the conquests of nations, the elaborate ceremonies of church and state, the sports and pastimes of the people and finally in their agricultural and commercial pursuits. 86. Performance. — The entire organization of the horse is designed to enhance his locomotion, and there is no domestic animal whose movements are so characterized by power, agility and grace as those of the horse. He is endowed with such mental limitations as to render his capabilities in locomotion most subservient to his master's demands. The performance required of the horse is FIG. 40. — Sagittal section of distal part of limb of horse. 1, large metacarpal (fore cannon) bone ; 3, fetlock joint ; 4, proximal sesamoid bone ; 5, first phalanx ; 6, pastern joint; 7, second phalanx; 8, coffin joint; 9, third phalanx ; 10, distal sesamoid (navicular bone); 12, suspensory ligament; 14, deep flexor tendon ; 15, superficial flexor tendon ; 16, posterior annular ligament of fetlock ; 20, inferior sesamoidean ligaments ; 21, extensor tendon; 24, plantar cushion; 25, periople ; 28, wall of hoof ; 29, sole of hoof ; A, navicular bursa, proximal part. (After Ellenberger-Baum, Anat. fur Kiiiistler.) structure of man, provided that man assumes the horizontal and quadrupedal position, and rests on the tips of his fingers and toes. The horse has no collar bone, the union between trunk and anterior extremities being wholly muscular, and the relative length of fore and hind legs is such as to maintain the body in a perfectly horizontal rather than an inclined attitude. He has one digit instead of five and rests only on the last segment of it, so that the wrist corresponds to the horse's knee, the knuckle to his fetlock joint and the three phalanges of the finger to his first and second pastern, and pedal bones (Fig. 40). Likewise the knee of the man is the stifle of the horse, the calf of his leg the gaskin of the horse, his heel the horse's hock, and so on as in the foreleg. As the man raises his weight well* up on his toes and feels the tension of the muscles of the thigh and lower leg he can well understand what takes place when the horse " lifts " in the starting or moving of a load or in merely projecting his own body forward, in locomotion. 88. Mechanical structure. — The structure of the horse, mechanically considered, consists of a trunk suspended by an arch, the vertebral column, supported at each end by four vertical columns, the legs, the anatomical features of which have already been described in Chapter II. Greater weight is borne on the forelegs because the appended head and neck bring the center of gravity well forward of the center of the body. The arrangement by which the body is slung between the two forelegs by the great pectoral muscles and the slope of shoulder and pastern provide for the supporting of this weight, especially during locomotion, with least concussion. The center of gravity being displaced further forward when the horse is in motion, still greater weight is thrown on the forelegs, the hind legs serving as propellers. The articulation of the thigh directly with the pelvis conveys the propulsive effort throughout the entire length of the spinal column. The supportive action of the forelegs meets the propulsive action of the hind legs in such a way as to restore the equilibrium of the body. The joints of the leg are hinge joints, capable of motion in two directions only, flexion and extension, while the joints of the hip and shoulder, points at which the legs articulate with the body, are ball and socket joints, which permit of a rotary motion. The legs, generally speaking, are therefore capable of alternate flexion and extension, which take place in the order named, although the flexion of the leg as a whole may involve the extension of some one joint, as in the case of the shoulder at the commencement of flexion of the leg. 89. The stride. — Flexion of the leg, which raises the foot from the ground, plus extension of the leg, which carries the foot forward until it comes in contact with the ground, again constitute a stride, and by the simultaneous or successive strides of the four legs, regularly repeated, the body is advanced. Each leg may engage in a stride independently, as in the case of the walk and the rack or single foot, in which the cadence is distinctly marked by four beats ; one fore and the opposite hind leg may operate separately, while the other two act as one, as is done in the gallop, there being three distinct beats but of irregular cadence; a fore and a hind leg may move in unison and mark but two beats, as in the trot, when a diagonal pair are concerned, as the near fore and the off hind, or in the pace, when a lateral pair, as the near fore and the near hind, cooperate. a passive period in this form of locomotion which each leg or set of legs experiences in alternate order. One leg, a pair of legs or a set of three legs supports the weight of the horse while the other leg or legs is executing a stride. Hence, we can distinguish a supporting leg and a striding leg, and we find that deviations in the way of going may be accounted for by abnormalities operative during either or both periods. For instance, some lamenesses are manifested only when the leg is supporting, while others are characterized as striding or swinging leg lameness. A horse may interfere because of a base-narrow, toewide position, which places the fetlock of the supporting leg so near the median plane as to insure its being struck, but the likelihood of its being struck is greatly enhanced by the fact that the same defective position of leg which causes the fetlock to approach the median plane is also responsible for the striding leg's being swung in a circle inward. This of itself might be productive of interfering, but to be added to the results of such a position in the supporting leg makes interfering doubly certain. On the other hand, the shortened stride of the spavined horse involves a condition which manifests itself in the striding leg only. 91. The phases of the stride. — The evolution of the stride involves five distinct phases, a preliminary, during which the leg is undergoing flexion, but the foot has not left the ground, — the point at which the real stride begins ; next, the breaking over, in which the foot is raised heel first and leaves the ground by being rocked up and over at the toe, although at speed the foot springs directly from the ground, not waiting to break over at the toe ; then flight, during which the foot is describing a more or less regular arc of a perpendicular circle ; followed by contact, at which point the foot is again brought to the ground ; and finally recovery, as the weight gradually falls on the foot and the original position of the leg is momentarily established preparatory to a repetition of the stride. 92. The features of the stride which constitute the way of going. — The following features are manifested by the stride as it is executed, some being most marked in one type of horse, while others are more characteristic of another. Length, as determined by the distance measured from the point at which the horse breaks over to the point at which his foot comes in contact with the ground again. passes in describing the arc of a circle in the stride. Elasticity, the spring with which the weight is borne by the leg and foot just before the commencement or just after the completion of the stride. cuted. The gaits are : 96. The walk, a slow, flat-footed, four-beat gait, which is one of the most useful if properly executed with snap and animation, whether in harness or under saddle. The walk should not be considered useful simply to afford the stride characteristic of this gait. horse an opportunity to rest, but should be regarded as a distinct form of locomotion, with as definite a purpose as any other gait which the horse goes. 97. The trot, a rapid, two-beat gait in which the diagonal fore and hind legs act together. There are three varieties of trot, viz. : the fast stepping trot, characterized by the length of stride and rapidity with which the individual strides are taken and constituting the gait of the har- ness race horse (Fig. 41) ; the high stepping trot, characterized by the height and elasticity of the stride, the horse placing himself, going collectedly and marking each step with extreme flexion as represented in the harness show horse (Fig. 42) ; and the saddle trot, characterized moderate knee action, and a springy stride. by a square, springy, collected and balanced stride, executed in perfect rhythm and with the utmost precision in order to insure the comfort and security of the rider (Fig. 43). The saddle trot is distinct from the long, swinging stride of the trotter, also the high, sometimes pounding step of the actor, and should reveal none of the horses degenerate. 98. The pace, a rapid, two-beat gait distinguished from the trot by the fact that the lateral fore and hind legs act together. It is characterized by the readiness with which pacers can get away at speed, more or less side motion (the so-called side wheeler), the absence of much knee fold, and therefore the minimum of concussion, and the necessity for smooth, hard footing and easy draft for its execution (Fig. 44). This, like the trot, is the gait of the harness race horse. 99. The amble, a lateral gait distinguished from the pace by being slower and more broken in cadence. The natural amble is the foundation for the so-called saddle gaits, exclusive of walk, trot and canter. 100. The rack, a fast, flashy, four-beat gait, well described by the discarded term "single foot" (Fig. 45). The rack is the gait which distinguishes the five-gaited saddle horse. While some display greater aptitude than others, few horses will rack of their own accord, or on the halter, but only when called upon to do so with both hand and heel, being ridden well up to the curb. It is preeminently a show gait characterized by considerable action and in many instances quite a bit of speed. 101. The gallop, a fast three-beat gait in which two diagonal legs act together, their one beat falling between the successive beats of the other two legs, the hind one of which makes the first beat of the three. With the third and last beat, the horse is carried clear of the ground and there is a period of silence broken by the contact of the independent hind foot as it begins a new series of strides. The two legs acting independently, the fore, with which the horse leads, and its diagonal hind, naturally bear more weight and are subject to more fatigue than are the other pair, which act simultaneously, and therefore share the work. The hind leg receiving the full weight, at the phase of contact at the conclusion of the jump, phase of this gait is not shown. bears more than the foreleg, which supports the weight alone, just before the projection of the horse at the beginning of the jump. The gallop may become so fast as to break the simultaneous beats of the diagonal pair, the hind foot striking first and causing four beats, although follow- is made to do under restraint, the weight being sustained FIG. 46. — The canter, the hind foot bearing the weight and beginning a new series of three beats at the phase of contact, after the horse has been projected clear of the ground by the independent forefoot. chiefly by the hind quarters, while the lightened forehand rises and falls in a high bounding fashion (Fig. 46). Inasmuch as the canter, like the gallop, causes special wear1 on the leading forefoot, and its diagonal hind foot, the lead should be changed frequently, a well-schooled saddle horse cantering on either lead at command. Cross cantering consists in so confusing the fore and hind leads that the simultaneous beat is of a lateral instead of a diagonal pair of feet, and this beat falls between the suc- hind on the same side. 103. The jump, either high or broad, is accomplished by the forelegs raising the forehand as the horse takes off in such a manner as to bring his body in line with the direction in which the jump is to be taken, when a strong propulsive effort of the hindquarters projects it over in the case of the high jump or across in the case of the broad jump (Fig. 47). Upon alighting the forefeet strike the ground first, the leading foot being a very little in advance, the horse immediately gathering himself and striding out of the way of the hind feet which follow quickly and come in contact with the ground slightly in advance of the prints of the forefeet. 104. The running walk, a slow, single foot or four-beat gait intermediate in both speed and execution between the walk and the rack, and suggestive of a continued breaking out of the walk. Whereas the rack is the show gait of the gaited saddle horse, the running walk is their business gait. At it horses make from six to eight miles an hour and it can be continued all day with no distress to either horse or rider. 105. The fox trot, a short, broken trot in which the hind legs go more or less of a pace, the horse usually marking the beats with his head and ears. It is used in place of the running walk in horses which take to it more kindly. 106. The stepping pace, a distinctly saddle gait, should be differentiated from the ordinary harness pace which is a mark of degeneracy in the saddle horse. The stepping pace is characterized by little if any side motion and a somewhat broken cadence in the action of the lateral pairs of legs. 107. The traverse, a side step, executed by both forehand and hindquarters, in response to rein on the neck and heel in the flank ; by it horses may be brought up to a gate to unlatch it or to " dress " in troop maneuvers. 108. Factors influencing the horse's way of going. — The particular features or deviations in a horse's way of going may be due to either of two sets of factors, natural and acquired. The former class include type, conformation, direction of leg and form of foot, all of which are governed by breeding ; the latter embraces educational tactics, mechanical appliances, and the going surface, which are encountered in the horse's schooling and handling. 109. Type as a factor. — Type involves structure and structure is correlated with function, therefore a horse will do as he is. His capacity for one sort of performance will be limited, for another enhanced, by the plan of his structure ; a long, lithe, angular horse will have more speed than power, while the draft horse is short legged, broad, square and compact. The stride of the former horse will be characterized by reach and extension, while the cobby horse, for instance, has a short but trappy stride. 110. Conformation as a factor. — Conformation, involving the details rather than the plan of structure, also influences the horse's way of going. The jumper has a straight hind leg short from the hip to the hock, while the pacer has a bent hind leg, long from the hip to the hock. Direction of leg and form of foot control the directness of the stride, the former determining the course that will be taken by the foot during its stride, whether it will be advanced in a straight line or describe the arc of a circle inward or outward, while the latter fixes the point at which the foot breaks over, whether the center of the toe, the outer or the inner quarter, depending upon whether or not the foot is symmetrical or the inner or outer quarter is higher. Weak pasterns. 111. Breeding as a factor. — The features of type and conformation which determine the horse's way of going are, in turn, matters of breeding which, in addition, is responsible for the mental factor which governs locomotion and is expressed by instinct. Instinct, type and conformation are usually correlated and not antagonistic. Instinct, however, has a broader application in determining the specific gait that a horse shall go, rather than influencing some particular feature of his stride. It is instinctively natural for trotting bred horses to trot, Hackneys to go high and Thoroughbreds to gallop. 112. Education. — Instinct, however, is not sufficient to account for the record attainments in the various gaits of some horses. Education is necessary in order to make the most of hereditary endowments. Given the natural aptitude to trot, step high or gallop, a system of schooling is employed for the perfection of these gaits. 113. Mechanical appliances. — It is in the schooling of horses that the mechanical factors influencing the way of going are resorted to. For instance, the snaffle bit, offering no opposition to the horse extending himself, is conducive to speed, and is therefore regularly used on race horses, while the curb bit, resulting as it does in restraint, is suggestive of a collected and high way of going, and is therefore of great assistance in the schooling of saddle and high-going horses. Weight influences the stride within limits ; increasing the amount of weight in the foot, either by the shoe or by permitting an overgrowth of the foot itself, calls for an extra effort to make the stride, and therefore results in a higher step, although excessive weight will defeat this purpose. The placing of weight in the different parts of the foot, as inside, outside, heel or toe, does not make as much difference as was formerly believed. However, weight at the toe in the position of the usual toe weight attachments will, upon the principle of the pendulum, increase the length of the stride by carrying the foot out, even turning up the toe, in extreme cases, while weight at the heel increases the height of the stride by requiring more lift on the part of the flexors. Hopples may be used to keep trotters or pacers in their stride or to convert from one gait to the other. 114. Going surface. — The surface over which the horse steps has a marked influence on the character of his stride which may be taken advantage of in the schooling process. As a general rule, heavy, soft or deep going causes a high stride, while a hard, smooth surface is conducive to speed. Of the speed horses, trotters and pacers take more kindly to the hard track than the runners, which do best on the turf or a deeply scratched dirt track. The difference in the going will frequently account for a horse's trotting or pacing, the heavy or deep going causing double-gaited horses to trot, while a change in footing will shift them to the pace. The common defects and peculiarities in the horse's way of going for which any of the preceding factors may be responsible or tend to overcome are : hind foot. 116. Interfering — striking the supporting leg at the fetlock with the foot of the striding leg. It is a common result of the horse's standing in the base narrow, toe wide or splay footed position. 117. Paddling — an outward deviation in the direction of the stride of the foreleg resulting from the toe narrow or pigeon toed standing position. foot as it breaks over. 121. Speedy cutting — in which the spreading trotter at speed hits the hind leg above the scalping mark against the inside of the breaking over forefoot as he passes. 122. Cross firing — essentially forging in pacers, in which the inside of the near fore and off hind foot, or the reverse, strike in the air, as the stride of the hind leg is about completed and the stride of the foreleg just begun. 123. Pointing — a stride in which extension is more marked than flexion, as is commonly seen in the trot of a Thoroughbred. Pointing also indicates the resting of one forefoot in an advanced position to relieve the back tendons while the horse is standing. 124. Dwelling — a scarcely perceptible pause in the flight of the foot as though the stride had been completed before the foot reaches the ground, and noticeable in actors. THE TYPES AND CLASSES THERE are four types of horses, the division being made upon the basis of mechanics, each type being subdivided into classes in accordance with market and show ring demands. The four types are power, speed, show and saddle. 128. The power type. — The service of the power or draft horse is to move the maximum load under minimum pace requirements and usually over the paved surfaces of traffic congested city streets. Stability of equilibrium is the measure of power ; therefore, the essential features of power horse type are those which contribute to or insure stability of equilibrium and muscular development. Factors to the former are weight, low station and breadth of body; to the latter, compactness, massiveness and bone, while depth, which is correlated with breadth and compactness, is a feature of stamina by which continuous service is sustained. The power horse (Fig. 48) should weigh from 1500 to 2400 pounds in order to have sufficient friction between his shoe and the hard surface of the street to give him a secure footing. Furthermore, weight thrown into the collar effectively supplements muscular exertion. Low station, determined by shortness of legs, increases the stability of equilibrium by bringing the center of gravity as near as possible to the base of support, that i 113 area of surface upon which the horse stands, included within lines connecting the four points of contact, his feet.. Length of leg in turn is largely a matter of length of cannon, and a short cannon is correlated with breadth, depth and compactness, all features of the power type. Breadth, involving primarily the skeleton, increases the base of support laterally, thereby giving greater stability of balance, and it also insures skeletal foundation for the development of a greater muscular system. Depth, directly related to heart, lung and digestive capacity, is essential in order that the horse shall be capable of maintaining a continuous supply of energy throughout his part. S.c., compact substance; S.s., spongy substance; C.m., medullary cavity; F.n., nutrient foramen. Note the greater thickness of the compact substance of the inner and anterior parts of the shaft. shall balance with the size of his superstructure. 129. Conformation of the draft horse. — The distinctive features of the conformation of the draft horse are: a head of such size as will balance the other features of a big horse, yet not manifest coarseness or low breeding; a neck that has sufficient length and shape to fit a collar well, though strong and muscular ; broad, muscular withers ; a shoulder with as much length and slope as is consistent with a short-legged, heavy-set horse ; a broad muscular arm and fore arm ; a wide, deep knee affording ample joint surface, the size of the horse considered ; a short, broad, flat, clean cannon bone ; a pastern of as much length and slope as will support the weight of a draft horse without sagging; a full, round, smooth coronet, elastic cartilages; and a foot that is large in proportion to the size of the horse, of half-flat shape, so as to insure greatest circumference and ground-gripping surface, yet strong in the heels and bars, with an arched sole which shows no tendency to drop or become too flat, as many draft horse feet do, and of such dense, smooth horn as will insure against the shelly, brittle hoofs to which draft horses are heir ; a short, broad, straight back ; round, deep rib ; short, broad, thick, level loin ; full flank ; smooth, short, strong coupling ; long, level, broad and muscular croup; thick thigh and stifle ; muscular gaskin ; broad, deep, smooth, straight, clean-cut hock ; with the same sort of hind cannon, pastern and foot as described for the front leg, the hind pasterns of draft horses showing a marked tendency to be steep. The legs should be set one under each corner, not on each corner, giving the bull dog effect that is noticeable in some very wide-fronted horses. The elbow should be in, not out. The hocks cannot be expected to be very close together in a horse that has much thickness of thigh, but hocks that are wide apart are defective. The four legs should line up straight from either side or end view. possess quality, as indicated in texture of bone, hoof and hair, and refinement of head and neck, in order to increase the wearing properties and to improve the general appearance. Quality is not natural to the draft horse, since he is primarily gross, but as much as is consistent with the required substance should be sought. 131. Temperament of the draft horse. — The nature of the work of the draft horse requires that he be steady and easily handled, hence his lymphatic temperament stands him in good stead, unless it makes him absolutely sluggish, which he should not be. 132. Way of going of the draft horse. — Since the most approved systems of draft horse management prescribe that he shall work at the walk, it is important that the walk, in his case, should be developed to its greatest possibilities. He should move at this gait with a powerful, yet snappy, free and true stride. He may be trotted for inspection, because the trot magnifies all features of the walk, and for a draft horse to be able to trot well gives assurance of mechanical excellence which will serve him equally well at the walk. 133. The speed type (Fig. 51). — This type is extremely opposed to the horse that has already been described . Speed performance calls for maximum pace with a minimum impost of weight to be pulled or carried. Instability of equilibrium is the measure of speed ; therefore, the type in general is one in which there is the least opposition to the rapid and repeated displacement of the center of gravity which takes place with each stride and in the direction of the leading foot. In addition to the rapidity with which successive strides can be taken, the length of the individual strides determines the speed. Muscular contraction, therefore, must be greatest in degree as well as most quickly accomplished, and the sort of muscles that are capable of such contraction are long, narrow and bandlike compared to the short, thick muscles of power. Instability of equilibrium as well as length of stride are favored in the horse that is long and rangy in order to have length in his stride ; lithe as the result of his muscular system consisting of muscles of the speed sort ; angular for the same reason, his form not being rounded out by the bulk of his muscles, nor by excess weight in fat ; narrow to permit of the greatest directness of shoulder motion, as a narrow base of support is in line with a rapid displacement of the center of gravity, and to minimize wind resistance ; deep to secure the heart, lung and digestive capacity which his performance necessitates, and yet which cannot be had by width. 134. Conformation of the speed horse. — The special features of speed conformation are enumerated in differentiating trotters, pacers and runners. (Paragraph 137.) 135. Quality in the speed horse. — Quality in the speed type is not only indicative of the structure's capacity to withstand wear and tear, but insures durability with least weight and bulk. 136. Temperament of the speed horse. — A nervous temperament is requisite to speed performance affording the nerve force and courage that is required to control and sustain the performance of which the speed horse is mechanically capable. the speed type may be either trotters, pacers or runners. Trotters and pacers, both going two beat gaits in harness, have much in common to distinguish them from runners, which attain speed under saddle at an altogether different gait, yet in some features, trotters and pacers themselves are quite different. As a group they are distinguished from the runner by a greater proportionate length of forearm and lower thigh, a different set to the hind leg, there being a greater tendency to a downward and forward deviation in trotters and pacers and less development of the forehand. Of the two, the pacer has greater length of leg in proportion to the body, a longer, steeper croup and more bent hocks. The runner is characterized .by greater development of the forehand, a much straighter hind leg with less proportionate length from the hip joint to the hock, a somewhat thicker stifle and a way of standing easy on his front legs. 138. The show type (Fig. 52). — So far as speed and power are concerned, show horse requirements are intermediate. It is the manner in which he moves and the the weight of the load which counts. These features are best obtained in a horse of a close and full-made form viewed from the side and end, respectively, because such a one possesses the rotundity and smoothness the heavy vehicles to which the show horse is put. 139. Conformation of the show horse. — His conformation is distinctive. In no type do good looks count more, and beauty of form involves conformation. Furthermore, certain structural features not only enhance general appearance, but are essential to the kind of performance required of the show horse. The head should be fine, especially about the ears, and so put on such a shapely neck as to permit of extreme flexion at this point, such as takes place when the horse places himself when going. Length, as well as shape of neck is essential to suppleness, the show horse being compelled to bend himself readily in every joint. On account of the full-made form the withers will not be set up to the same extent as in the saddle horse, but a long, sloping shoulder and a comparatively light forehand are requisite to action. In the same way long, sloping pasterns contribute to height and elasticity of stride. A high-set tail is effective in setting off a high stepper's performance, and it can only be had on a long, level, smoothly turned croup. 140. Quality, temperament and way of going of the show type. — Quality in the extreme as an important adjunct to finish and good looks, and a temperament that is proud, bold and stylish in order that his performance may be in line with his physical features and the purpose to which he is put are important. 141. The saddle type. — The saddle horse (Fig. 53) not only has to carry weight of from 135 to 200 pounds or over, but he is required to do it in such a manner as to afford satisfaction to his rider and incur no distress to himself. The various gaits at which the weight is carried serve to differentiate the classes of saddle horses. Ability to support weight depends upon a short-span arch, represented in a short, closely coupled back and loin, resting upon strong columns — short, stout legs. To carry the weight, the horse is required to move in balance, collecting himself under his load, going well off his hocks and keeping his legs under him as much as possible in order to be supporting the weight at all phases of the stride. The big horse is not necessarily the weight carrier ; unless he is properly set up, his own size may be an encumbrance to him, while many ponies, by virtue of their distinctly weight-carrying build, are capable of much more than would be expected of them. 142. Conformation of the saddle horse. — Special conformation requirements of the saddle type are a saddle back, short, straight and strong ; a light forehand insuring handiness in carrying weight, a heavily fronted horse not only giving a rough ride but being a blunderer, as a rule ; a long, sloping shoulder, longer than in any other type of horse, to give a free, springy stride ; and high withers, extending well back, the result of the long, sloping shoulders and serving to keep both saddle and rider from working forward, giving the impression of much horse in front of the rider, forming the narrow front which affords the most secure seat by favoring thigh and knee grip and obviating the difficulty of a wide spread of legs, and preventing the turning of the saddle. Such shoulders and withers are correlated with the long, supple neck so essential in the saddle horse. 143. Quality of the saddle horse. — Quality, combined with substance, is desired in the saddle horse, quality being especially required of the park saddle classes, while substance is necessary for carrying weight. Quality is characteristic of the blood lines in which most saddle hofses are bred ; substance is therefore most apt to be deficient. 144. Way of going of the saddle horse. — The stride of the saddle horse is distinguished by elasticity, especially, and the' safety of the rider demands that he be sure-footed. 146. Intelligence of the saddle horse. . — A wellschooled saddle horse should be thoroughly responsive to the hand of the rider on his mouth, the rein on his neck and the heel on his side ; he should change gaits, canter on either lead, or in a circle, back and traverse at command, all of which requires a responsive mouth and intelligence of a high order. and expressers. 146. The drafter. — The truest exponent of the power type already described. There is some distinction to be made, however, between the market draft gelding (Fig. 54) and the extreme of the power type. In considering the essential features of power, height is of much less importance than weight and station, but in the selection of draft geldings height is more important. The draft horse market is ruled by buyers who make the appearance of their teams on the city streets a feature of their advertising policy, and in establishing the top of the market for draft horses they have more in view than simply horse power. Al- though somewhat contrary to power, the object of appearance is better served by horses which have more stature than the strict power type permits of. Otherwise, when put to the large trucks and vans, the low-down horse will appear squatty, and the effect of the entire equipage will be marred. Drafters are worked singly, in pairs, threes, fours and sixes. 147. The logger. — Briefly, a draft horse minus quality, being coarse, unsymmetrical, low bred or badly enough blemished to be disqualified for the city trade, and taken for service in the woods where power only counts. 148. The chunk. — A drafter minus scale, being the extreme of draft form as indicated by his name, but under weight, usually ranging from 1200 to 1500 pounds (Fig. 55). He is handier for the rough work of farmers and contractors and the more rapid hauling that is required in the delivery service of breweries and such concerns than the typical drafter. doing his work at the trot. He is on the line between the work horse and the heavy harness horse divisions so far as his makeup is concerned, embracing some of the size and substance of the draft horse with more of the shape and finish of the heavy harness horse (Fig. 56) . Expressers vary in weight from 1250 to 1500 pounds and are sometimes subclassified into light and heavy delivery. 160. The feeder. — Any thin horse bought for the purpose of fattening may be properly termed a feeder, but as this practice is limited to horses in the work division, the typical feeder belongs to the draft class or one of its subclasses. 151. The coach horse. — A horse of sufficient size and substance to pull a brougham or road coach (Fig. 57), yet possessing enough quality, style and action to make a good appearance. Twelve hundred pounds weight, sixteen hands height, is standard size. They are required to make a good show while going about an eight-mile pace, and be well enough mannered to go anywhere through city traffic or stand in pose for long waits. The park horse is the most typical representative of the show type. He should be able to go, flashily, a pace of twelve miles an hour with a most extravagant flexion of knees and hocks. Park horses are driven singly, in pairs and fours, put to the gig, the Sayler wagon, demi- mail, Stanhope, spider or George IV phaeton (Fig. 58), park drag and Victoria, owners to drive, usually, in all but the last instance. They are classified by height. 153. The cob is best described as a big, little, ride or drive, horse. He exemplifies the close, full-made form and high action of the show type, but has unusual bone and muscular development in his comparatively short legs. The typical cob is so extremely close and full made that the term cobby is used to denote such a form. The cob is intermediate between the heavy harness and pony divisions. 154. The runabout horse. — The nature of his service is indicated by the name of the vehicle to which he is put, and handiness is his most essential feature. To this end he should be small, not over 15 hands 1 inch, as a rule, and combine some of the step of the road horse with some of the shape and action of the park horse, although extreme action is not typical of this class. Runabout horses should stand without hitching, back readily, and display the best of manners at all times (Fig. 59). This horse may be considered intermediate between the heavy harness and the light harness divisions. latter of which may be either trotters or pacers. 156. The roadster (Fig. 60) typifies the trotter described under the speed type, but is required, in addition, to be of good size and conformation and to have some style, a smooth gait, even though not possessed of extreme speed, and the best of manners. Pacers are not generally recognized in road classes on account of the fact that they pull a wagon unsteadily over any but the best of going, their side motion in their gait, to the various kinds of footing. 166. The speed horse may be either a trotter or a pacer possessed of sufficient speed, stamina and gameness, to render him a successful race horse. Unfortunately speed performance alone is about all that counts, although the better class of speed horses conform very closely to the road horse just described, possessing extreme speed in addition. Road horses are hitched singly or in pairs to the American road wagon, while speed horses are hooked to sulkies or speed wagons, depending upon whether or not amateur rales obtain. SADDLE HORSE DIVISION The saddle horse division embraces the race horse or runner, the gaited saddle horse, the walk-trot-canter saddle horse, the hunter and the combination horse. 167. The race horse is of most extreme speed type, but is used exclusively under saddle. He is a natural galloper, having a wonderful reach and length of jump ati the run, but a low, pointing stride at the trot. Running races are conducted on the flat or over the jumps of the steeple-chase course, some horses showing a natural aptitude for the jumps, whereas others cannot even be schooled to take them successfully. Runners are handicapped by the weight which they are required to carry. 168. The gaited saddle horse (Fig. 61). — Since instinct to go certain gaits is hereditary, and only those horses which instinctively go certain gaits can be schooled to a satisfactory performance at them, the majority of gaited saddle horses are Saddle bred, and conform to the description of the Saddle-bred horse given elsewhere. Performance, the fox trot or stepping pace ; the trot ; the rack ; and the canter. See pages 99-107. They carry full mane and tail and represent the southern and western idea of a saddle horse. 169. The walk-trot-canter saddle horse. — This class may be subdivided into the American or Saddle bred and the English or Thoroughbred saddle types (Fig. 62) . The former is distinguished from the gaited saddle horse only by the fact that he either has not been schooled or is not permitted to go more than the three gaits and is usually docked and has his mane pulled. The Thoroughbred type (Fig. 63), representing the English idea, is a well-shaped, good-headed Thoroughbred that is not characterized by the usual pointy trot, but can trot in the collected, springy, weight carrying way that is required of the saddle horse. They are usually undocked but have their manes hogged. 160. The hunter. — This horse is required to carry weight cross country after fox hounds, which necessitates his jumping safely any obstacle likely to be encountered in a cross-country run, having stamina sufficient to stay with the pack as long as they run and to be able to gallop fast enough to follow the hounds. He must have a good head to keep a steady hunting clip and be at all times under the complete control of his rider. The hunter is a weight carrying saddle horse in the extreme sense of the term, having strong, well-developed shoulders and withers, muscular quarters and ample bone. Size is sought as being conducive to safety; the regulation fence is lower for a sixteen-hand horse than for one of only fifteen hands' height ; furthermore, in case the horse blunders, the momentum of his weight will allow him to break through the obstacle, whereas the lighter horse would probably trip and come down. Then, other things being equal, the bigger horse is up to more weight, and many people who ride to hounds are following the sport to keep down avoirdupois. Hunters are classified on the basis of weight to which they are up, as light weight (Fig. 64), 135 to 165 pounds, middle weight, 165 pounds to 190 pounds, and heavy weight (Fig. 65), 190 pounds or over. They are also classified as qualified or green, depending upon whether or not they have hunted one season with a pack recognized by the United Hunts and Steeple Chase Association. 161. The combination horse. — Nearly all saddle horses are broken to go in harness and many harness horses may be ridden, but in either case they do much better at the one performance or the other. There is, however, a horse of which equally satisfactory performance is expected, whether under saddle or in harness, and he is therefore termed a ride-and-drive or combination horse. Although it is customary, for convenience' sake, to show combination horses in harness first, he is more typically a saddle horse going well in harness than a harness horse that is capable of giving a good ride. The combination horse is distinguished from the saddle horse proper by being of a somewhat more harnessy form with more speed at the trot. Under saddle he may go either three or five gaits, the former usually being shown in heavy harness and the latter in light harness. Classes for " model " horses and for " fine " harness horses are in the catalogs of most southern shows. They both favor the Saddle-bred horse. 162. The model horse. — These horses are judged on conformation and quality only, performance not being considered, and classes for them constitute a most effective means of promoting uniformity of type and individual excellence. . 163. The fine harness horses are, in a sense, model horses in harness, the ideal being a horse of extreme refinement and superior conformation, having neither speed nor great action but going, most attractively, a ten or twelve mile pace. PONY DIVISION There is an increasing tendency, so far as the shows are concerned, to disregard any common pony type, but to differentiate between ponies on their conformity to either harness or saddle standards, the same as is done in horse classes. In a general way any equine under, fourteen hands two inches is a pony, but it is not so at the shows. breeding and type (Figs. 66 and 67) ; ponies eleven hands two inches and not exceeding fourteen hands two inches, this class being frequently subdivided at thirteen hands (Figs. 68 and 69) ; and polo ponies (Fig. 70) . There are both harness and saddle classes for ponies of each of the first two specifications, and the same ponies may show, and even win, in both, but the line is being more sharply drawn between the harness and the saddle pony types. The heavy harness standard is adhered to in judging harness ponies, while in saddle classes both miniature walk-trot-canter and hunter types are considered. predominate. 165. Ponies eleven hands two inches, and not exceeding fourteen hands two inches. Ponies of this class are regarded as little horses best adapted to the use of youths 166. Pola ponies. — The polo pony usually stands close to the fourteen hands two inch standard, is of race horse or hunter type, up to weight, handy, fast and clever in order that he may fully qualify for the intricate performance incident to the game. I Hackney 167. The Percheron. — The typical Percheron (Fig. 71) is distinguished from the representatives of the other draft breeds by characters which can be attributed, primarily, to. the hot blood in the breed's foundation and to the fact that these horses were originally bred for rapid draft service. Percherons do not possess the scale and substance of the Shire, the extremely drafty form of the Belgian, the broad, flat, straight hocks, sloping pasterns and accurate way of going of the Clydesdale, nor the usual good rib and the uniform coloring of the Suffolk. They average of medium draft weight, stand over considerable ground for a draft horse, have a somewhat toppy general appearance, and a form that has been most appropriately described as of "a flowing, rounded contour indicative of promptitude of movement as well as strength" l instead of square and blocky. They possess more general refinement, a better proportioned and more breedy head, and better texture of blue hoof than horses of any other draft breed. They also reflect their Oriental ancestry in an THE BREEDS OF HORSES active, somewhat nervous temperament and go with unusual snap and dash. Gray is the most typical color, though blacks have been most common, and bays, browns and chestnuts occur but are not favored. modern draft requirements by his breeders resorting to stronger infusions of cold blood, but selecting to retain the activity and refinement of the original to as great an extent as the law of correlation would permit of. and is surpassed in weight only by the Shire. He is extremely compactly put together with square, massive ends and a short, wide and deep middle, characters with which there are too frequently correlated a short, thick, heavycrested neck and short, straight, stubby pasterns. The head is of medium length, broad and deep and strong in the jowl, eyes not sufficiently large or prominent and ears set too low sometimes. His short legs are heavily muscled in the forearm and the gaskin, although the bone is often not of the best quality nor the feet as large and round as the size of the horse requires. Belgians, while essentially cold in their make-up are good movers, es- the prevailing colors, although black and gray occur. 169. The Clydesdale.— The Clydesdale (Fig. 73) is distinguished by a mechanical perfection in locomotory apparatus which is not generally equaled by representa- tives of other draft breeds. The set of the legs, the slope of the pasterns, the quality of the bone, combined, as it is, with ample substance, and the straight, free, springy, yet powerful stride are most characteristic of this breed. However, such a stride is impossible in a horse of extreme draft form, consequently the typical Clydesdale is a more upstanding and correspondingly longer, narrower and shallower bodied individual than the representatives of the other draft breeds. This is comparatively speaking, however, as the Clydesdale is in every respect a draft horse, and his stamp has some things to commend it over the other extreme, which is the only type recognized by some draft horse judges. The Clydesdale has length of neck and slope of shoulders which fit a collar admirably, and which with their long, level croup constitute two ends of a very good top line, provided the back is not too low, as is sometimes the case. Clydesdale colors are bay and brown most commonly with a profusion of white markings ; black and gray are not rare. 170. The Shire (Fig. 74). — Bulk and bone are the two features which characterize the Shire most. They are the result of selection to the Englishman's ideal of a draft horse, backed up by an environment in Lincolnshire and Cambridgeshire, England, where they were bred, which is most conducive to just such a structure as the breeders strive to attain. His great scale and substance, with his form, are most impressive of draftiness. Yet with all there is a grossness that is suggestive of a low grade of material in his construction. The head is large, especially long, with the face line inclined to be Roman, and the countenance expressing a sluggish temperament. The hair coat is luxuriant, the mane and tail being especially heavy and feather abundant with oftentimes vestiges of the mustache and tufts at knees and the points of the hocks by which the old Flanders horse was characterized. There is a wide range of colors in the Shire, bay, brown, and black being most common, gray and chestnut not unusual and roans occasional, all considerably marked with white. The way of going of a Shire is that of a great horse. He moves slowly, almost ponderously, with a lack of freedom in his stride, but there is power in the movement. Straight shoulders and pasterns, flat, shelly within the confines of one county, descending exclusively from an individual foundation sire, and having been bred primarily for agricultural purposes, this breed is of exceptionally uniform type (Fig. 75) . The most striking features are the invariable chestnut color and the " punch" form, i.e. a low set, full, round, compact, massive body. They have fairly fine, intelligent heads, rather full crested necks, corresponding to their ample bodies, and clean legs, devoid of feather. All shades of chestnut are encountered ; flaxen manes and tails are not unusual but white markings are. Suffolks, while they never have been regarded as a heavy draft breed, are quite frequently not up to draft weight. The punch bodies and clean legs are sometimes overdone, giving the effect of too fine bone under a large superstructure. 172. The Hackney. — The antecedents of modern Hackneys were a race of stoutly made trotters possessed of the stamina requisite to the performance of seventeen miles per hour, and they were up to any weight. They represented a Thoroughbred top cross on a common base, the trotting proclivities, in this instance, being alleged to come from the Friesland trotter blood in the dams. This stock was later made the basis of selection to harness requirements, and so faithfully were selections made and requirements met that the Hackney is to-day the heavy harness horse par excellence. The typical representative (Fig. 76) was formerly a low set horse, very close and full made, and therefore weighing more than his height would indicate. Greater favor is now expressed for a more upstanding, finer individual. However, Hackneys rarely exceed 15-3 in height. The form is harnessy in the extreme, being especially rotund, the head well proportioned, with a straight face line, a deep jowl, a neck of fair length and well crested, an especially round rib, smooth level croup, full muscular quarters and ample bone. Chestnut color with white markings all around is the rule, although bays and browns are common. The way of going of the Hackney is characteristic. He is naturally disposed to be proud and stylish and goes with a degree of action that is unexcelled, hocks especially being sharply flexed. There being no discrimination in the studbook between full-sized Hackneys and ponies, the line between them is not sharply drawn. Mares of some size are mated with pony stallions and vice versa, with the results that there are many undersized individuals, over the pony limit, yet too small to be acceptable as horses. The naturally full, well-crested neck shows a tendency to be too strong in some cases, the thick throttle compressing the larynx when flexed, as it is when the horse is driven. Hackneys are essentially high steppers and some do not go on in their stride but tramp too much in the same place. Stamina, also, has not been sought nor required in the performance for which the Hackney is best qualified. They should not, however, appear soft. Height of stride increases concussion, but that is not sufficient excuse for some Hackneys pounding as they do, nor should their action be labored, but airy. 173. The French Coach (Fig. 77) . — Demi-sang or half blooded to begin with and having been bred for cavalry service primarily, the French Coach horse is not as readily distinguishable as the other heavy harness breeds in which the type is more uniform. The most approved individuals of this breed are about sixteen hands high, and weigh from 1200 to 1400 pounds ; are rather upstanding, sufficiently close and full made to be of true harness form, yet manifesting no suggestion of draftiness. They should reflect their proximate Thoroughbred ancestry 'by their refined heads and necks and the texture of bone and hoof in their legs and feet. Hard, solid colors prevail, although one or two white points, though rarely more, are common. They move with a creditable show of both pace and action. In addition to the rather general lack of uniformity of type there are many individuals of this breed that display too much of the cold character of their original maternal ancestry. Others, which give much promise standing still, are most indifferent actors, and even among those which go well there is a tendency to do it all in front, failing to follow with a balanced action of hocks. 174. The German Coach (Fig. 78). — Tap rooted in the region to which the Flemish horse was indigenous and bred primarily for the mounting of the heavy, fully equipped German trooper, size and substance predominate in this breed. They stand full sixteen hands or more and some weigh fifteen hundred pounds, being the largest of the heavy harness breeds. Size and substance, without the introduction of any draft character, and hard, solid colors, more uniformly than in any other breed, are the characters by which German Coachers are distinguished from representatives of the other heavy harness breeds. joints, a sluggish disposition and inability to step either high or reasonably fast are features which judges of this breed of horses should discriminate against. the American road driver who first sought harness speed, bred from a composite foundation, in which the Thoroughbred top cross figured most conspicuously, the base consisting of common bred mares which had shown an aptitude to trot, due, perhaps, to the blood of the Dutch trotter, this horse has been bred to a standard of speed perform- ance. As a result, the type is not uniform, although the extreme speed performance has been attained in a wonderful degree and with extraordinary regularity. Standardbreds (Fig. 79) range in height from pony stature to sixteen hands and in weight from 800 to 1200 pounds or over, the most approved size being about 15-3 and 1100 pounds. They conform to the general speed type, modified in those special features which distinguish trotter and pacer from runner and jumper, i.e. a lower forehand, a longer, more sloping croup, greater relative length from elbow to knee, and from hip to hock, resulting in the hocks being set farther back, and necessitating a more abrupt deviation of the hind legs downward and forward to the ground. The head of the Standardbred is of good size, not especially fine, but clean cut, the neck of medium length, lean and straight. The way of going is most characteristic. Whether at trot or pace the gait is distinguished by the length and rapidity of the individual strides, and the level, true, frictionless manner in which they are executed. Furthermore, the instinct to trot is well marked. Colors are not at all uniform although bays predominate. The Thoroughbred. — As indicated by the name, this is the purest breed of horses, except the Oriental, from which they are derived. They were the first to be improved and the first for which pedigree records were kept and a stud-book established. They also have been bred for about two and one half centuries with running speed as the sole consideration. The typical Thoroughbred is characterized, therefore, by the strongest evidence of breeding and refinement, together with a racy form and temperament. The most representative individuals (Fig. 80) stand near sixteen hands, and weigh 1000 to 1100 pounds. They are rangy, with that length of legs, body and neck which is conducive to a long stride. They conform strictly to the speed form, in fact, are the truest exponents of the speed type, distinguished from the trotter and pacer by greater range, better development of the forehand, more level croup, thicker thighs, less proportionate length from hip to hock, and therefore a straighter hind leg, longer, more sloping pasterns, a smaller foot of finer texture, finer bone, and a predisposition to stand over at the knee. The head is the smallest and best proportioned, with features and lineaments most sharply defined ; the neck long, slender, and especially well cut out at the juncture with the head, which it carries well forward rather than up ; the shoulder longest and most sloping, the withers highest, leanest and most extended. Bay, chestnut and brown with white markings are the most common colors, although black, gray and white were formerly not infrequent and are yet sometimes seen. The way of going of the Thoroughbred is very characteristic ; being essentially a galloper, his walk and trot are nol as good as that gait at which he excels. He walks indifferently and trots with a low, pointing stride in front and a dragging of hocks. At the gallop, however, it seems as though his whole makeup were designed with that end in view, each part acting coordinately with the others to make a perfect gallop. The ranginess of the speed form is sometimes overdone in the Thoroughbred, rendering him weedy (too long-legged and light-bodied). There is also a tendency, in some individuals, to be too fine in bone and too small, especially when measured up to the present standard. Quite commonly they are too " hot " in temperament and erratic in disposition. Judges of Thoroughbreds usually distinguish between the race horse and the hunter and saddle horse, especially when they are concerned as sires. 177. The American Saddle Horse. — This is a Thoroughbred derivative, rendered especially adaptable to the purpose for which bred by the ambling instinct contributed by the " native " mares with which the foundation Thoroughbreds were mated. Since their foundation, Saddle horses have been selected to a model, as well as a performance, standard. They may be distinguished by the following characters (Fig. 81) ; an upstanding horse of most symmetrical and beautifully molded form, a well-proportioned, blood-like head, the features of which are most clearly defined, an intelligent countenance, and an exceptionally long, shapely and supple neck, on which the head is set in a lofty, graceful manner. The two ends are the most characteristic parts of the Saddle-bred horse, the long, level croup and unusually high set and proudly carried tail balancing the lofty carriage of head, in compliance with the Kentuckian's idea of " Head up and tail a-risin'." An extreme degree of quality, finish and style, with a rich bay, brown, chestnut or black color, usually moderately and evenly marked with white, complete a beautiful picture horse. The way of going was formerly distinguished by the rack, but with the increasing favor shown the walktrot-canter horse the rack has been omitted in many representatives of this breed. The trot is quite frequently marked by more action than is usually required of saddle horses, and is, in fact, well suited to harness performance. The highest class Saddle-bred horse is a show horse in every sense of the word, whether under saddle or in harness. So much has been made of the two ends of the Saddle horse that they are sometimes deficient in the middle, being both low in the back and short in the rib, while the quality by which they are characterized may be had at such a sacrifice of substance as to render them too fine. encountered. 178. The Shetland. — This is the smallest of the equine breeds, a standard of 42 inches and a limit of 46 inches, in excess of which they cannot quality for registration, having been established (Fig. 82) . Shetland ponies are used to pack peat, the universal fuel used by the native crofters of the Shetland Islands, and they frequently carry loads of 140 pounds. They were first introduced into Great Britain for service in the mines to get the coal out of the shallow veins, where horses and mules could not go. The child's pony idea is claimed to have originated in this country. For these reason's it is not difficult to account for the variance in type from the British and the American points of view. The old country type is naturally a pony of power, — a draft horse in miniature — while the American demand is for a pony of less blocky form, with a finer head and neck, a better shape, especially in forehand and hindquarters, and more step. The natural stride is short and pointing, any great display of action usually being due to weighting, which is often excessive. Shetland color is most typically a cinnamon brown or black, although piebalds, skewbalds, bays, chestnuts and even odd colors, as dun and mouse color, are encountered. Breeders generally prefer the hard, solid colors, while the broken colors are most popular with the buyers of ponies for children's use. against. 179. The Welsh. — Derived from a hardy race of ponies native to the Welsh mountains, this breed has been improved in shape and way of going, partly by means of Hackney crosses, till they are very typical heavy harness horses in miniature (Fig. 83). They range in height from the Shetland limit of 11 hands 2 inches to the pony limit of 14 hands 2 inches. The foreign Welsh Pony and Cob Stud-book extends its classification to include, as cobs, horses of Welsh breeding which stand as high as 15 hands 2 inches. The classification follows : Welsh ponies should be considered more in the nature, of little horses than as children's playmates, like the Shetlands. Some go high and others can step quite fast, while all have extraordinary stamina. Bay and brown ill shaped. 180. The Hackney Pony. — This is simply a Hackney under 14 hands 2 inches, with all of the breed characteristics accentuated (Fig. 84). Although " with no pride of ancestry, no hope of posterity," as the Missourian has well said, and therefore eliminated from the scope of this work in so far as selection in breeding is concerned, there is ample justification, if little precedent, for including the mule in this discussion. He rules supreme in the field of the work horse in the South, while in some other agricultural districts he is depended upon for the farm work, and his use in the cities is considerable. It is important for those who use mules, as well as those who purchase them, to know what mule excellence consists of. Mules have been variously classed, in accordance with the nature of the work to which they are put, but there are essentially but two types, draft and plantation. 181. The draft mule. — These mules are used for power service chiefly outside the cities or at least off the city streets. Mules pull more by their muscular strength and steady, persistent effort than by virtue of their weight, and are especially handy and sure footed in rough and trying places. They " push " rather than " lift " their load. For this reason, as well as on account of the small circumference of their feet and comparatively less weight, they are not as satisfactory on paved city streets as horses. THE MULE 169 The draft mule (Fig. 85) weighs 1200 to 1250 pounds and stands fifteen hands three inches to seventeen hands, a mule being taller in proportion to his weight than a horse. Obrecht l shows one weighing 1900 pounds and standing eighteen hands two inches. This mule conforms to the draft horse type in being low set, broad, deep, compact, masfeive and big-boned, with quality manifested particularly in smoothness and a straight, strong way of going. in lumber camps. Miner is characterized by being more blocky and rugged with most power in least stature. They range in height from the twelve hand pitter for working in low chambers to the sixteen hand mule for work at the surface. Their weights vary, accordingly, from 600 to 1300 pounds. the soft ground through the heat of the day and be surefooted, so as not to tramp plants in cultivating. The mule for this service is more rangy and snappy than the draft mule, characters derived from more hot blood in the dams and therefore associated with less size and substance in the mules. Representatives of this type (Fig. 86) weigh from 950 to 1200 pounds and stand fourteen hands two inches to sixteen hands two inches. They are built more on the rapid draft order, conforming somewhat to the shape of an express horse, and should have especially good legs and feet, a high degree of refinement, an active, nervous temperament and be straight, free, snappy movers. cotton and farm. The sugar mule is for the use of the Southern planter. He is the best representative of this type, rangy, smooth, with great quality and breediness, yet ample bone. tion mule of the same general type as the sugar mule. The farm mule class comprises the poorer grades of the other two classes, or thin mules that might feed into either of the other classes which are purchased by the farm trade. Mare mules are usually preferred as being smoother, better shaped and easier keepers. Seal brown is the color most desired, then bay, chestnut and gray. THE TYPES 183. The block group. — Preliminary to the consideration of beef cattle, those features characteristic of all the block group, namely, beef cattle, mutton sheep and fat hogs, in common, may be disposed of. All vertebrates are possessed of a muscular system mounted upon a skeleton foundation which serves the purpose of locomotion or any other motion of which the animal is capable. Under feral conditions animals resort to movements of various kinds for their sustenance and their protection. The husbandman has in this instance, as in many others, perverted a natural function into other lines more useful to him, and this muscular system which was furnished the animal as a means of moving, living and having its being becomes the source of one of man's most concentrated, nutritious and digestible foods. 184. Meat, although it may mean any food, is generally understood to be a portion of the animal's body composed chiefly of muscle, the connective tissue by which it is supported, the fatty tissue by which it is enveloped and interspersed, and the section of the skeleton upon which it is mounted. The animal from which the meat is secured gives to it its specific nature, as beef, mutton, or pork. Meat, however, is a carcass term and is not applied to the tissue mentioned in the living animal. The synonymous term, having reference to the animal rather than to the carcass, is flesh. Yet there should be discrimination in the use of this term. To speak of eating the flesh of animals implies a meaning identical with meat, but reference to the natural flesh or the thick flesh, of feeder steers, for instance, includes the muscle only, without the fat, and therein lies the distinction. Whereas the muscle that is most efficient for movement is of such firm texture and so devoid of any fat as to render it tough, the chief feature of the muscle which constitutes the desirable lean of meat is just the reverse. The function of meat-producing animals is the conversion of common foodstuffs, in a form not available to man, into a concentrated, palatable, easily digested form of protein and fat. The profit returned by them is divided between the breeder who produces them, the feeder who finishes them, the butcher or packer who dresses and wholesales their carcasses, and the retailer who purveys them to the consumers, their ultimate end. It is rare, except in the case of production for limited farm or home use, that one and the same individual is concerned with each step. 185. The breeder's, the feeder's and the butcher's interests in the meat animal. — Success, on the breeder's part, consists in producing an animal that is a satisfactory butcher prospect acceptable to the feeder. The feeder's business is to secure, in the shortest feeding period and with the most economic and productive use of food, the most highly finished and satisfactory butcher beast. The butcher's proposition is to obtain, in the dressed animal, as high a percentage of his gross live weight as possible and to have the maximum amount of the dressed weight carried in those parts of the carcass for which there is greatest demand and the highest price paid. The re- taller, finally, buys ribs and loins of such quality of meat as will secure for him the most generous patronage of those consumers who appreciate and pay for the best meats. Type is therefore the primary consideration of the breeder ; early maturity, feeding and rapid fattening capacity, of the feeder ; dressing percentage and distribution of the weight in the carcass, of the butcher ; and quality, of the man who cuts the carcass on the block. Economy in production is a matter of type, early maturity, rapid fattening and dressing percentage. Quality of the product depends upon the breeding, feeding, age and dressing of the animal and the cutting of the carcass, and consists of texture, color, consistence, distribution and proportion of the fat and lean and the percentage of meat to bone. 186. The block type. — Prime carcasses of meat are produced by immature, unsexed animals, more commonly males, of the block type fed to their optimum degree of ripeness. The block type is characterized by a blocky or rectangular form set on short legs and furnished with thick flesh (Fig. 87). 187. Early maturity. — There is a marked difference in the extent to which individuals will develop in the same period of time. Interest on investment, labor and feed must all be charged against gross receipts to determine the net profit returned by any block animal, and these three important profit factors are all reduced in the case of the early maturing animal. 188. Rapid fattening is usually correlated with early maturity but should be distinguished from it. One animal matures rapidly, fattening readily at the same time ; another may mature slowly, then fatten quickly, after once mature ; still another may reach maturity promptly, in chilling. 190. Quality in meat. — So far as the consumer is concerned quality consists of such a fine, delicate texture of the meat as will insure easy mastication, toughness being most suggestive of low quality to the majority of meat eaters ; also such flavor as will make the meat most palatable, this being of secondary importance to texture as a rule, because flavor may be altered to such an extent in the cooking process. The relative nutritive values of meat figure less in the consumer's demand and are, therefore, of less concern to the judge. The grain of the meat involves especially the part of the carcass from which the cut is taken, improving toward the center of the carcass away from the extremities, the coarser cuts being taken from the neck, shoulders, shanks, the small part of the leg and the rump, the loin and rib cuts being finest . grained. Old animals, as a rule, have coarsergrained muscle tissue with more connective tissue in it than do younger ones. proportion of fat to lean is desirable, since it is impossible to secure, age, or prepare prime meat without fat. The better As a matter of fact, the so-called juices are not altogether blood and cell protoplasm, but fat. A lean piece of meat will be dry when served. In order to impart, as well as preserve, juiciness in the meat the fat should be distributed though the lean as well as accumulated on the surface of the cuts. Interspersed within and about the bundles of individual muscle fibers (Fig. 88), it constitutes the marbling that is most noticeable in the rib (Fig. 89) and loin cuts of beef, which in addition to furnishing been demonstrated that the fat that is most disposed to thus distribute itself instead of accummulating either externally or internally is of a white, not yellow, color, and of a crisp, brittle, not greasy, consistency. Also that the lean most likely to be well marbled is of a clear, deep, red color when cut, neither light red nor bluish, and it has a firm, elastic consistency, neither flabby nor doughy. 194. Moisture. — Prime meat should just moisten the finger when touched, and should not be slimy. Either immaturity or old age may be responsible for a slimy condition, as may also emaciation from any cause. of preservation has scarcely any odor. 196. Taste not only depends upon the prime nature of the meat and the manner of preparing and serving it, but upon the care exercised in dressing. A sheep butcher, for instance, will use the utmost care in turning back the pelt so that the wool may not touch the carcass and give it a woolly taste. 197. Proportion of lean to bone. — The amount of the bone in proportion to the weight of the carcass concerns the consumer most of all, bone being waste to him, and on this account rough, coarse-boned steers, hogs and sheep are discriminated against all along the line. Refinement of bone is a feature of the general refinement which results from improved breeding and is correlated with quality of the carcass in general and little waste. 198. Influence of breeding. — Feed is prerequisite to fat, but the amount, distribution, color and consistence of the fat as well as the color and consistence of the lean and the shape of the carcass are matters of breeding. For instance, representatives of leading beef and dairy breeds have been fed the same rations under identical conditions for equal periods with extremely different results between the individuals of the beef and dairy groups.1 This test carried through to the actual cutting of the carcasses demonstrated what has usually been found to be the rule, i.e. that the beef-bred animal increases his weight by the formation of fat, while' the dairy-bred steer grows an excess of bone ; that the former deposits his fat in, as well as upon, the lean, thus enhancing the actual value of the carcass as well as increasing the dressing percentage, while the latter accumulates an excess of fat about the viscera, organs which, with the exception of the kidney, are removed in dressing, the carcass showing no marbling whatever; that the fat of the beef carcass is of the sort described above, while that of the dairy animal is high colored and buttery, the lean of the former fine grained and of good color, while that of the latter is cross grained and dark colored. Cattle (Bos taurus) are the largest of the domesticated ruminants. They were early domesticated and have served the triple purpose of work, milk and meat in the order named. They are especially adapted to the consumption of large amounts of roughage and are thus conservators of much that would otherwise be wasted. BEEF CATTLE The unsexed male or female, of immature age and in prime condition yields the most desirable carcass of beef, — bulls, stags and old females, especially worn-out dairy cows, being utilized chiefly as cured beef or cut up for the lower class trade. 199. Production. — Since the best beef animal is the one which hangs up the most superior carcass, the slaughter test must be kept in view by the beef cattle judge, and the most exacting demands of the consumer patron of the retail butcher should be given due consideration. It seems reasonable that the "judge of beef cattle should be a connoisseur of sirloin. Since quality of beef is one The beef steer is, however, required to do more than to satisfy the demands of the beef-eating public ; he must return a profit to his butcher, his feeder and his breeder. The factors of quality already considered determine whether or not the carcass will grade as prime and bring the highest price, but there are other factors which fix the other limit of the butcher's margin of profit that are of equal importance. The butcher pays 8 cents a pound for the live steer which weighs 1200 pounds on foot. He immediately subjects the steer to slaughter and dressing which converts him into two sides of beef and the dressing offal, consisting of hide, head, shins and feet, blood, chest and abdominal viscera and their contents. This, with the shrinkage incident to the loss of moisture in chilling, may amount to from 50 % to 25 % of the live weight of the steer originally purchased . While with modern packing methods every particle of the offal has some value, the aggregate will not amount to as much as its original purchase price. Furthermore, there are many pounds of the dressed carcass that must be sold at from 25 % to 50 % less than they cost. Therefore the burden of responsibility for the profit to be yielded by the carcass must rest upon those parts for which a price much in excess of cost can be secured. Quality being equal, the steer that will hang, in dressed sides, the greatest amount of his live weight and that carries the major part of his dressed weight in those regions of the carcass which command the best price, is most profitable. 200. The beef carcass cuts. — The division of the carcass as it is cut up by the butcher should be anticipated by the judge. These divisions are indicated by the following diagram (Fig. 90). FIG. 90. — Beef carcass cuts. 1, 2, 3, round ; 4, 5, 6, loin ; 7, rib ; 8, chuck ; 9, flank ; 10, 11, plate ; 12, shank ; 13, suet. 1, hind shank ; 2, round, R. & S. off ; 3, rump ; 4, 5, loin end ; 6, pinbone loin ; 5, 6, flatbone loin ; 10, navel ; 11, brisket. 1, 2, 3, 4, 5, 6, 9, hindquarter; 7, 8, 10, 11, 12, forequarter ; 7, 8, back; 7, 10, piece; 8, 11, 12, Kosher chuck; 8, 10, 11, 12, triangle, a, aitch bone; b, rump bone; c, crotch; d, cod; e, chine bones; /, "buttons;" g, skirt; h, breast bone. Illinois Bulletin 147. After being bled out, the head, hide, extremities and viscera removed, the carcass is split into halves. When chilled until set, each side, herefter a unit in the trade, losing all idenity with its fellow, is cut into fore and hind quarters, division being made between the twelfth and thirteenth ribs. One rib is left on the loin to act as a stay and hold its form in order that it may be better cut. The hindquarter, the more valuable, is divided into loin, rump and round, after having the kidney, with its accumulation of suet, and the flank removed. 201. The loin is separated from the rest of the hindquarter by cutting from the stifle, through the hip joint to the rump. The loin includes both sirloin and porterhouse. The sirloin (Fig. 91) is cut forward as far as the point of the hip or hook bone and is identified, when cut, by the cross section of pelvic bone which it contains, the rouud section of the shaft in the first few cuts and the crescent shaped section of the wing as the margin of the porterhouse is approached. The porterhouse (Fig. 92) is cut forward from the point of the hip or rather backward from the last rib to this point, in the region of the loin proper, and this cut is identified by the " T " bone. This consists of a lumbar vertebra split in two, which forms the cross, while the lateral process of the one side constitutes the stem ; the tenderloin is contained in the lower angle thus formed. by the tail head. The round cuts contain only the transverse section of the femur or thigh bone. The best quality of meat is on the inside or the top of the round as it lies on the block. neck and plate. 203. The ribs. — The prime ribs (Fig. 94) include the seven ribs counting forward from the loin end of the forequarter, which brings the division of the rib and chuck between the fifth _^ — , made ten to thirteen inches from the back bone. 204. The chuck includes the balance of the ribs and the shoulder blade, limited below by continuing through the shoulder joint the cut that divides the prime ribs from the plate. The cross cut ribs and the clod are taken from the chuck at the arm, the remainder of the leg being the shank. The fore part of the plate may be separately designated Total 100 206. Relative values of the carcass cuts. — Since the beef steer is a straight business proposition, the most important thing for the judge to know regarding the carcass cuts is their relative values. They rank as follows : the highest priced cut of the carcass is the loin, the rib cut is valued at from 10 to 20 % less, per pound, than the loin of the same grade ; the round at 40 to 50 % less than the rib ; the rump is worth a little less than the round ; the best grade of chucks sells at about the same price as the rounds ; while the plate, the flank, the shank and the neck 207. Dressing percentage. — The dressing percentage of the steer involves type, quality and condition, while the relative weights and values of the different parts of the carcass are determined by type and conformation. of any but beef type. The type of steer that favors greatest weight in the carcass, least waste and the greatest proportion of weight in the most valuable cuts is that which conforms to a block or rectangle, being low set on short legs, with top and under lines parallel, the square brisket and hindquarters outlining a parallelogram in profile, while the broad, flat back and loin and wide ends complete the rectangle (Fig. 95). 209. Conformation of the beef steer. — The head of the beef steer serves as an index to the rest of his make-up and should therefore be the opposite of that of the dairy cow, i.e. short, broad and deep, with a more placid, even lazy expression of countenance ; the eyes large, full and clear ; the muzzle broad, the nostrils large ; the ears of medium size, set high and carried alert ; the horns symmetrical but not coarse, or a sharp, well-defined pole ; the neck as short as possible, thick, yet not heavy in the throat, especially full in that region where the neck blends with the shoulder, termed the shoulder vein ; the shoulders well laid in, thickly covered, the side of the shoulder being one place that is especially liable to be bare, broad across the top, without being rough or open but so well covered as to be compact and smooth at this point ; chine broad and level with a thick covering of mellow flesh, also straight, showing no sag toward its juncture with the loin ; ribs well sprung, deep and thickly covered, especially on the fore rib, that region designated as the crops, a round, deep rib also contributing to the heart girth and abdominal capacity ; chest deep, full, level on the floor and square at the brisket ; loin broad, thick, smooth, no rolls, level, with no sag or tie where it joins the back; flank deep and full, making a straight under line; hips broad, level, smooth and not prominent; rump long, broad, level and smooth, showing no coarseness of bone about the tail head and no unevenness of covering, in the nature of patches, about the tail head or pin bones ; thighs broad, thick, and deep, well rounded in appearance from any angle and especially full and low in the region of the inner, lower thigh, known as the twist on account of the rotation of those muscles which takes place when the carcass is hung up by the hamstring, the juncture of the two thighs being referred to as the seam of the twist ; the legs short, straight, strong and fine boned. 210. Quality in the steer influences the dressing percentage by controlling the amount of waste or offal. It also makes a higher grade carcass, quality of hide and hair, for instance, being correlated with quality of lean and fat. Quality is of hide and hair, indicated in a loose, medium thin, pliable, unctuous hide covered with a medium coat of fine, soft, straight hair and determined by handling; of bone, as evidenced in a comparatively small, fine head and horn, smooth shoulders, hooks and pins, small cannons, and clearly defined joints; of flesh, as shown by an even, smooth covering over the back, loin and rib with no rolls or patches of fat and neither too soft nor too hard a feel. Quality is also concerned with general trimness and refinement of the animal throughout, indicative of breeding. 211. Condition has most to do with the weight that is left in the carcass after dressing away the offal. Of course, internal fat increases the amount of waste, but every pound of fat fed into the carcass itself increases the dressed weight and therefore the percentage of live weight, that much. Show animals regularly dress more than ordinary market toppers, chiefly because they are fatter. Condition is ripeness and until the steer has reached this state he has not attained maximum production. Condition or ripeness is indicated by a full purse, flank and tongue root, these being the last places at which fat accumulates in the ripening process. 212. Feeder cattle. — The butcher deals with an actuality, the feeder with a prospect, but in order to be successful in his operations the feeder must keep the butcher requirements constantly in view (Fig. 96) . The feeder's profits depend, first of all, upon the production of an acceptable butcher's beast, but secondarily upon the economy with which this can be accomplished. There is a vast difference in the relative efficiency of individual steers so far as economy in production is concerned. Not all show steers are popular with the packers, but even some which are market toppers are money losers when the cost of production is charged against even the premium price which they bring. 213. Feed lot production. — So far as becoming a bullock acceptable to the butcher goes, the feeder steer is the butcher steer minus condition, but in economic production the feeder introduces a feature that is of no account to the butcher, namely, constitution. Profit in the feed lot requires that the cattle shall be good " doers," disposed to consume a full ration, regularly, with no skips or misses due to off-feed periods, and then capable of making full return in gains for each pound of feed consumed (Fig. 97) . In addition, therefore, to being bred right feeders must show evidence of thrift, vigor and growth, with early maturity and capacity to fatten rapidly, yet evenly. Just what the fattening process consists of, as well as what it accomplishes, is also of vital concern to the judge of feeder cattle. It should be understood that the gains in weight shown by cattle on feed represent either an increase in the of a fattening ration fed. 214. The type of the feeder steer (Fig. 98). — Short, broad heads, wide, flat backs, muscular necks and thighs even though thin, sappy hides, full heart girths and lymphatic dispositions which render the cattle only sufficiently aggressive to get all the ration due them, then disposed to lie down and grunt and grow are the features upon which the selection of feeders is based. It is essential to know the fat steer which is the feeder's outcome before passing judgment upon the thin prospect. 215. Method of inspection. — Beef cattle are first viewed from in front, noting their scale, width and low station, then the size, dimensions, proportions, contour and features of the head. Passing to the side the lines are observed, noting especially any sag in the back, droop of the rump or prominence at the tail head, lack of fullness in either crops or fore flank, trimness of under line, and depth of hind flank ; then the head in profile, the shortness of the neck, fullness of the shoulder vein, thickness and character of the covering over the back and loin, on the outside of the shoulder, in the crops, on the mid rib, and at the juncture of the back and the loin, as determined by handling, and the length, levelness and smoothness of the rump, setting on of the tail and depth and fullness of the hindquarters. From the side the hide is handled just over the back rib and midway down. The rear view covers the width of the animal throughout and especially of the shoulders, back, loin, rump, thighs and twist, and the fullness, depth and closeness in the seam of the latter. The opposite side is observed in the same order as the first. The legs of a fat steer, ready for the slaughter, are of little account. Feeders are usually picked under conditions that permit of only a very general inspection. They are often sorted as they are run through the alleys, past the mounted buyer who indicates which of the two pens, accepted or rejected, they are to be allotted to. DAIRY CATTLE The primitive bovine female possessed, in common with all mammals, the capacity to produce milk with which to nurture her young to a self-sustaining age. For this purpose she was required to give but a small amount, of ordinary quality, the scant flow of which was maintained by the succulent spring grasses whose growth was incident to the season at which she invariably calved. The modern domesticated dairy cow, on the other hand, has given annually, in record instances, milk equivalent in amount to from 25 to 30 times her own weight, and so rich in fat as to yield more than the equivalent of her weight in butter. Furthermore, she may be made to freshen any month in the year and to maintain the milk flow continuously for a period of years in some instances. Live-stock husbandry offers no more striking example of the development of a natural function by means of generations of selective breeding. 216. Production. — The function of the dairy cow is to furnish, for any ten months in the year, milk in such quantity and of such quality as to return a fair margin of profit over the cost of maintenance of the cow herself and the additional expense of her production. 217. Dairy form and function. — The province of the dairy cow can be best understood by considering her as a factory, of which the udder is the essential machine, and in this she stands intermediate between the grain bins finished product in the pail. There is a most distinct correlation between form and function in the dairy cow; therefore a detailed consideration of each is essential to the intelligent judging of her. Milk is composed of 87.1 % water, and 12.9 % solids, of which .7 % is mineral matter, 3.2 % casein, 5.1 % sugar and 3.9 % fat, the last three constituents being products of the udder, exclusively. Hence the udder is the final and determining factor in milk production, but its function is wholly dependent upon allied and prerequisite systems and organs. These will be taken up in order. 218. Dairy temperament. — Since the production of beef and milk are in no way correlated but are extreme opposites, the primary factor in milk production is the absence of any tendency to beefiness. All the allied functions, as well as the secretory function of the udder itself, are so governed by the nervous system as to insure the most complete utilization of food nutrients exclusively for milk production, after maintenance requirements have been met. 219. Reproduction. — Given the capacity to divert surplus nutrients from the body to the pail there must be furnished a motive for so doing. Although the undeveloped udder of the virgin heifer and even the rudimentary gland of the bull may be stimulated to the actual production of milk, yet the calf is the only means of bringing cows into a state of profitable production. Under modern methods of dairy husbandry the calf is commonly deprived of that for the production of which he has furnished the incentive. Once fresh, a cow may be kept milking continuously for years, sometimes, without the necessity come in annually. 220. Feeding capacity. — After being supplied with a reason for becoming functionally active it is necessary that the udder be supplied with the materials from which to produce milk. This function devolves upon the digestive system as a source of the nutrients and the circulatory system as a means of conveyance to the udder. 221. Constitution. — In view of the record performances of some cows it is apparent that high production involves the expenditure of an enormous amount of energy and nerve force to sustain it. A race horse is hardly required to have more stamina and constitution than a cow on test, while resistance to disease is of even greater importance in her case on account of the artificial conditions under which she is kept producing. 222. Udder. — The udder has been referred to as the essential machine of the milk factory, — the cow. It is not a mere reservoir in which the milk accumulates and from which it is simply withdrawn, but the udder is a gland with secretion as its function. While the glandular arrangement does provide a receptacle for the milk as it is produced, secretion goes on most actively during the milking process, and is even controlled, within limits, by the cow at will. The active factors in milk production are the gland tissue cells which intervene between the terminal capillary ramifications of the blood vessels and the ultimate divisions of the interior of the udder (Fig. 99). The water, salt and some free albumen pass directly from the blood into the interior of the gland, but the greater part of the albumen undergoes transformation in its passage through the cell and reappears as casein. Fat and lactose may also be considered the products of the cell, since they do not appear in the blood. Fat is produced by a special secretory activity of the cell itself during which its proto- plasm undergoes marked changes and the characteristic globules of fat appear (Fig. 99A). This important function of the epithelial cells which line the finer sections into which the lumen of the udder is divided can be demon- strated, microscopically, by comparing the appearance of the active cells in the secreting udder with those that are inactive, in the dry cow or the virgin heifer (Fig. 995). FIG. 99 B. — Alveoli of the mammary gland of goat at the time of parturition, showing successive stages of secretion, a, epithelium at rest ; b, alveolar content consisting of cells ; c, smooth muscle cell ; d, connective tissue; e, alveolar content consisting of coagulated • casein and free fat : /, fat droplets in the epithelial cells ; g, blood capillaries. (After Martin.) 223. Dairy type (Figs. 100 and 101) . — Since the production of milk and beef are not correlated, the dairy form is characterized by an extreme absence of all that pertains to beefiness. The form in general is triangular instead of rec- tangular, outlining the so-called wedges, the appearance of which is contributed to by the features of structure already enumerated, the functions of which are prerequisite to milk production. Both reproduction and milk production are distinctly feminine functions, hence femininity should dominate the make-up of a dairy cow. The feminine form is characterized by a light, shallow, narrow forequarter and correspondingly greater width and depth of the hindquarter. This, of itself, is suggestive of both a horizontal and a perpendicular wedge, the apex directed forward whether seen from the side or the front. The wedge or triangle suggestion is made more pronounced in the profile view by the base of the triangle being extended to the lowest point of the udder at which the under line begins. This line is kept low at the rear by a deep back rib and full flank, features of digestive capacity, but inclines gradually upward on account of the absence of the square brisket that is characteristic of the beef type and the male and is, therefore, foreign to the dairy female. The very lean neck and fine throttle complete this under line, the head being eliminated from consideration. The light, narrow shoulder and chine that is correlated with femininity and the absence of beefiness, with the width on the floor of the chest that a cow must have in order to insure ample heart and lung capacity, are responsible for a third triangle, the apex of which is directed upward and is most easily made out when the chine is looked down upon. A fourth, an inverted triangle, may be demonstrated in the hindquarters. The long, broad, level rump forms the base, while the light thighs, concave from both side and rear view, form lines which, inclining downward and inward, approximate an apex. These triangles or wedges, it should be understood, are the effect rather than the cause of a cow's being productive, and mean little except that they represent capacity of the reproductive, digestive, respiratory, circulatory and nervous systems in a female whose proclivities are most extremely opposed to beef production. 224. Conformation. — A long, narrow feminine head with a straight face line, except as altered by breed character ; a large, clear eye, with mild expression, yet indicative of nerve force ; forehead broad and flat ; ears of medium size, fine texture, set high and well carried ; horns that are symmetrical in size and shape, of fine texture, with considerable curvature to distinguish them from the long, spreading, straight horn of the steer and the short, heavy horn of the bull, the size, shape and color of the horn being features of breed character and varying accordingly ; the neck long and lean in the extreme, showing concavity of both top and sides and a light, clean-cut throat; the shoulders long, light, well laid in and narrow on top ; the forelegs straight with ample bone ; the chine narrow and light, its spines sharp and wide apart or open, the foreribs deep and arched below ; the back long and straight, with no sag, the back ribs well sprung and deep; the loin broad and level, the flank deep but rather open ; the hips wide apart, prominent, as in an open frame, and symmetrical ; the rump long, level, broad and lean, the pin bones wide apart, the tail head smooth and on a line with the back, showing no droop, the tail long and fine with ample switch ; the thighs long and lean, concave from both side and rear view, any natural tendency to beefiness FIG. 102. — The points of the cow. 1, muzzle; 2, face; 3, forehead; 4, throat; 5, neck; 6, dewlap; 7, shoulders; 8, wethers; 9, back; 9i, crops; 10, chine ; 11, ribs ; 12, foreribs ; 12i, foreflank ; 12, 12i, chest ; 13, belly ; 14, flank ; 15, loin ; 16, hips ; 17, rump ; 18, setting of tail; 19, thurl or pin bone; 20, quarter; 21, thigh; 22, hock; 23, switch; 24, leg; 25, stifle; 26, udder; 27, teat; 28, forearm; 29, knee; 30, shank; 31, hoof. these are the points of the productive dairy cow . Udder. The udder is considered last because its efficiency is not independent but is contingent upon all other structural and functional features of the cow. The three essential features of the udder are its size, shape and texture (Fig. 103). Size is determined by its attachments, which should be high up between the thighs behind and well forward along the abdominal wall below. These attach- in reality there is less gland present than in a much smaller but wellsupported udder. With these points fixed, the shape of the udder is next concerned in establishing its capacity. The mammary gland is divisible, longitudinally, into two lateral halves, also transversely, into an anterior and a posterior or a fore and hind half. Therefore either half may be subdivided into quarters. The most capacious udder, size as fixed by attachments being equal, is the one in which all four quarters are equally well developed, producing a square and level shape. Finally, even though size and shape of udder are both good, there is one more factor that may still determine great variation in productiveness, and that is texture. The udder, like any other gland of the body, is composed of two kinds of tissue, the gland tissue proper which does the actual secreting of the milk, and an interstitial connective tissue of a fibrous nature which serves as a framework for the gland. It is obvious that the latter tissue has no part in the function of the udder, although a certain amount is necessary for the construction of the gland. The udder that is most productive, therefore, is the one that contains the most of the active glandular tissue and only as much connective tissue as is required to support the gland. The relative proportions of these two kinds of tissue in the udder structure are indicated by the feel of the gland ; if firm and beefy the connective tissue is in excess, while if soft, elastic and glovelike, being covered with a thin, pliable skin upon which is a light growth of fine hair and the blood vessels are distinctly marked, the udder is composed of the maximum amount of gland tissue proper and is capable of maximum production. Such an udder almost completely milks away, leaving only a few soft folds where, previous to milking, the udder had completely filled the space between the thighs. The former kind, on the other hand, appears of about the same size and shape after the milk has all been withdrawn. Udders may be so badly stretched by prolonging the periods between milkings, or cows may be judged in such varying stages of lactation that the udder alone cannot always be considered to gauge a cow's productive capacity. The mammary (milk) veins and wells are accessories which may be valuable aids in determining the capacity of an udder, especially if the cow is not in full milk. The mammary (milk) veins are the blood vessels which carry the blood away from the udder and the wells are the orifices in the abdominal wall through which the veins FIG. 104. — Section of cow's udder. G.R.M., lymph gland of udder; L.p., lymphatics of hindquarter ; L.a., lymphatics of forequarter ; L.E., lymphatics leaving the udder; A.M., mammary artery; V.M ,, mammary vein ; V.Ma., anterior mammary vein ; C, transverse inter-mammary septum. (After Moussu.) enter to unite with the general venous system. Their significance lies in the fact that their capacity is proportioned to the amount of blood which is supplied to the udder, the arteries being so deep seated as not to be visible (Fig. 104) .* A vein of large caliber and tortuous course indicates a large flow of blood to the udder, while a small vein passing directly from the udder to its well indicates 1 The so-called milk veins are designated, anatomically, as the anterior mammary veins to distinguish them from the middle and posterior mammary veins which together drain the venous ring at the base of the udder. the opposite. Since the raw materials from which milk is produced are conveyed to the udder in the blood stream, the relation between blood supply and production is very intimate. The size of the wells corresponds to the size of the veins and the larger, more tortuous veins usually branch and send small ramifications through smaller wells, the so-called extensions, of which there may be two or three. The escutcheon, that area on the inner, posterior face of the thigh where the hair is directed the reverse way, was formerly believed to indicate the blood supply and through it the capacity of the udder. This theory was first advanced by Guenon, a Frenchman, but little importance is attached to it now. Teats should be placed in the center of the quarters and if the latter are of the proper size and shape the teats will all be equidistant and directed straight downward, in parallel lines. They should be of sufficient size to insure a good grasp with a man's hand, short teats being an abomination in this country where men milkers are most common. The teats should not, however, be so long as to render them liable to be tramped upon by neighbors when the cow is lying down and the udder, with its teats, is protruded sideways. They should be regular in form and tapering. Supernumerary teats, while they may indicate extra development of the mammary system, are usually objectionable. 226. Quality. — Quality of cow and quality of milk are not correlated, exactly, yet the refinement of structure manifested by the cow may have a direct bearing on productiveness. The udder being composed of a framework of nonsecreting tissue and the essential secreting gland tissue which it supports, the more there is of the latter, the greater the capacity of the udder and the finer its much as of hide, hair and bone. Quality in the dairy cow is indicated by a hide of medium thickness, loose, pliable and unctuous, covered with a medium coat of fine, straight, lustrous hair ; a high grade of bone, noted in a fine head, smooth shoulders, hooks, pins and tail head and sharply defined joints ; horn of medium size, and dense, smooth texture. Coarseness is especially indicated in the parts enumerated and in a general absence of refinement. 226. Substance, as indicated by size rather than by bone, is important, it having been demonstrated that the larger cow produces more economically than the smaller one. 227. Constitution. — The consumption and utilization of the nutrients required for the production of 25,000 pounds of milk or 1000 pounds of butter annually, involves the activity of the functions of digestion, respiration, circulation and lactation to their utmost capacity, and none but cows of the strongest constitutional vigor are capable of such performance. Constitution is indicated by a full chest, a deep flank, a large nostril, a bright eye, a sleek coat and general evidence of thrift and vigor. 228. Condition of the dairy cow in milk is best expressed by the term " spare." Thin is suggestive of emaciation while a working dairy cow is in the best of health and thrift. Spare means without surplus, and that is most descriptive of ideal dairy cow condition when she is retaining from the fation sufficient nutrients for her maintenance only, utilizing all the balance for production. Lean is also expressive of the dairy condition, as it implies the absence of fat or beef. • 229. Temperament. — The dairy cow is of a nervous temperament compared to the lymphatic temperament of the beef steer. Resourceful in nerve force, yet not restive, is the ideal. Dairy temperament is indicated by evidence of nerve force as expressed by the eye, the absence of any beefy tendency, the spare condition associated with dairy capacity and an open, loose-made frame, especially in evidence in the chine. 230. Dry cows. — One is often called upon to buy or place cows after the conclusion of one lactation period, and before they have freshened again. It is obviously a more difficult task to rate them aright under such conditions than when in full milk. The higher condition which they naturally acquire when not producing must be distinguished from actual beefiness, and the inactive udder from one of normally limited capacity. The fat cow will show it most over the back, while the beefy cow is thick in the neck and thighs as well. The attachments of the udder high up behind and well forward, also its texture and balance may still be made out, although the form is much altered and the size reduced. The placing of the teats is a valuable guide in the case of the dry cow as well as in the heifer. 231. Heifer calves. — The judging of young heifers involves some features not enumerated in the judging of milking cows. It cannot be expected that the calf will be a " perfect little cow." Like the feeder steer, she is the dairy cow in prospect, and must have embraced in her make-up the essential features of dairy form and function, such as a refined, feminine head and neck, a loose, soft, sappy hide, ample chest and abdominal capacity and a suggestion of milkiness in both fore and hind quarters (Fig. 105). Special importance is attached to the size and placing of the teats, they being about all of the mammary apparatus that is apparent at this age. Teats of uniform size, placed equidistant and well apart, are indicative of a large, well-formed udder at maturity. Heifers, like dry cows, are usually in higher condition than after calving, when their fat " milks away," as it is commonly described. 232. Method of inspection. — The cow should be viewed first from in front, noting her feminine appearance, her triangular wedge shape and size, then, more in detail, the size, dimensions, proportions, contour and features of her head ; passing to the side, observe again the wedge form, outlined by her top and under line, also her head in profile, her throat, the length and leanness of her neck, the lightness and the sharpness of her shoulder and chirie, tfte depth of her forerib,the thickness through the lower part of her chest, the great depth of back rib, the width of loin and hips, the length, levelness, leanness and smoothness of her rump and the extreme leanness of her thighs ; from the side the hide over the back rib is handled to determine its thickness, looseness, pliability, the amount and fineness of the hair and the abundance and the color of the skin secretions, these secretions being also examined in the ears, under the tail and at the depth of the switch. Also, from this position, the size, form and texture of the udder, the size and placing of the teats, together with the size and course of the mammary veins and wells may be determined. This examination should be continued from the rear position, in which may also be made out the inverted, perpendicular wedge of the hindquarters, the width of loin, hips and hindquarters, the relative width of hook bones and pin bones, the leanness of thighs, the width between them and finally the es- cutcheon, its extent and form. The inspection is concluded by a look at the other side, noting again, as has alrsady been done, the openness of the form as indicated in the chine especially, and the general spare appearance indicative of the dairy temperament. It is well to move the cows about in order to verify or extend one's estimate of them. 233. Production. — Cows of this type are to serve the twofold purpose of milk and beef. In principle and theory the dual-purpose idea is subject to some logical opposition, but the dual-purpose cow is a matter of fact, 90 % of the milk supply of London being derived from milking Shorthorns, the breed that also furnishes a large part of the beef consumed in Great Britain. The principle is opposed on the ground that milk and beef are extreme opposites under the law of correlation, and therefore their joint production, in the same animal, is contrary to the laws of nature. And so it is if extreme production in both lines is attempted, but between any two extremes is a mean, represented by an intermediate or halfway position. It is, therefore, perfectly reasonable to expect from one individual the production of milk to the extent of one half the normal in dairy cows, and the production of a carcass of beef at least 50 % as valuable and one half as economically produced as in the case of a typical beef steer. This is all that should be attempted and apparently all that can be accomplished in the perfection of the dual-purpose cow. The great difficulty seems to be that breeders are not satisfied to maintain this middle ground, but are ambitious to make either dairy or slaughter records with their so-called dual-purpose cattle. Even the judging of the leading dual-purpose breeds has been most inconsistent on this account. One judge, presumably from the Middle West, will lay special stress on the beef form, with an utter disregard for udders, while an Eastern judge is just as liable to place the cows in the order of dairy merit only. The half-and-half principle is fundamental, and whenever it is deviated from; the dual purpose is defeated. The ideal dual-purpose cow is one which will produce milk of such quantity and quality as to return a profit over and above her cost of keep, and at the same time possess a sufficiently beefy form to insure her male calves feeding satisfactorily into acceptable butcher cattle, while she herself and her daughters will yield a profitable carcass when their usefulness in the dairy is over. Another difficulty in the way of dual-purpose attainment on the part of the breeder is the fact that the proposition is self-limiting. Many of the best dual-purpose cows are bought up by dairymen who follow the practice of milking a cow only through one milking period, then turning her to beef and the butcher. Thus the breeding value of the best cows is lost, and what calves there are produced are likely to have second-rate cows for their dams. 234. The dual-purpose type. — The half-and-half idea also prevails in the make-up of the dual-purpose cow (Fig. 106). She has considerable scale, more than is common in dairy cows, her form is less beefy than is typical of the steer, but more beefy than the typical dairy cow, while she is less milky in form than the representative dairy cow, but more milky than the fat steer. Her udder will probably be as large as that of a dairy cow, but inferior to it in both form and texture. Heifer calves should develop into the likeness of their dams, and the bull calves follow the same general type, but, being males, they will incline more naturally to beefiness. In practice it seems to be less difficult to get a cow that will give 10,000 pounds of milk annually and still retain her beef form, and make a profitable and acceptable carcass, than to secure from her a male calf that will make a steer altogether satisfactory to either feeder or butcher. The chief features by which typical representatives of each of the breeds may be differentiated are size, form, character of head, hide and color. 235. The Short-horn. — This, the first of the beef breeds to be improved, and the one to which were devoted the efforts of that select group of eighteenth century stock men, who proved out the theories of Bakewell, and established the principles upon which modern live-stock husbandry is practiced, is of extraordinary importance because of the improvement wrought by it on the common stock the world over. The representative Short-horn (Fig. 107) is essentially a beef animal, and unless specially qualified should be so considered. (Milking Short-horns are discussed in the dual-purpose group.) Short-horns may be differentiated from the other beef breeds by greater size, the cows weighing 1400 to 1600 pounds, and the bulls 1800 to 2400 pounds ; a more distinctly rectangular form, especially marked at the ends, on account of the square brisket and very long, broad and deep thighs, and a proportionately broader and flatter back, particularly toward the hindquarters ; a head full of character and refinement, horns that are short, medium fine, white and waxy in appearance with black tips and well curved ; and a hide of medium thickness, loose, pliable and sappy, covered with a heavy but mossy coat of hair. The Short-horn colors are red and white, either one exclusively or both in any possible combination, as red, white, spotted or roan. The whites are no longer discriminated against, nor are the reds especially preferred, while roan is regarded ?,; the most representative color. maturity and rapid fattening, and promise of dressing out most profitably a high-class carcass of beef. A lack of general conformity to the most approved beef type is sometimes noticeable in this breed, some leggy individuals appearing in the ranks. — A Polled Durham bull. 236. Polled Durham (Fig. 108). — This breed is an American derivation from a straight Short-horn foundation, chiefly, the majority of Polled Durhams being doublestandard, and therefore entitled to full registration in the Short-horn herd book. The aim of the Polled Durham breeders is to duplicate the Short -horn in all respects same basis. 237. The Hereford. — This breed, developed from a race of cattle native to Herefordshire, England, a district noted for its grassland, received mention as early as 1627 for being unusually economic and rapid producers of beef, characters for which the breed is still most noted. They have the reputation, in this country, of meeting, excep- tionally well, the conditions of our southwestern range country where beef is made from grass and frequently under most adverse climatic conditions, such as drought. Herefords are also conspicuous in the feed lots of the Middle West. There is a striking uniformity among the best representatives of the Hereford breed (Fig. 109), especially in the matter of color. They are among the heaviest of beef THE BREEDS OF CATTLE 221 cattle, although, being unusually low and blocky, they do not appear to possess as much actual scale as Short-horns do. The form is less square and more cylindrical than that of the Short-horns, their thighs being full and rounded, rather than straight. The hide is somewhat heavy, but loose and pliable, and covered with an abundant coat of long, curly but soft and fine hair, which covers the forehead in heavy curls and hangs in locks from the ears. The color, while originally the cause of much dissension among Hereford breeders, has become a most distinct and characteristic feature. Other breeds are red and white, but the distribution of the white in the Hereford is most regular. The face, usually including the ears, jaws and throat, is white, evidence of the old mottled faces being noticeable sometimes in red spots about the eyes ; the under side of the neck, the dew lap, the brisket, more or less of the under line, the legs and the switch are also white, and, most curious of all, there is a clear-cut white stripe on top of the neck from about its middle to the top of the shoulders. The balance of the neck, body and legs are red, either of light, medium or dark shade, the medium being preferred. On account of the regularity with which these white markings occur,, the Herefords are popularly known as " White Faces." 238. The Aberdeen-Angus. — Two distinct races of polled cattle have existed in Scotland since the earliest times of which we have record, one in northeastern Scotland, which was later evolved into our modern AberdeenAngus, and the other in southwestern Scotland, the ante- cedents of the Galloways. The hornless cattle of northeastern Scotland, the best of which were black, first attracted attention on account of the superior carcasses of beef which they dressed out. Their pioneer breeder was a cattle buyer, who early appreciated their butcher value and bred for improvement along that line. Partisans of the breed to-day assign to them first rank among butcher beasts as attested by actual competition in slaughter tests to which they refer. Aberdeen-Angus cattle do possess a fineness of bone, a wealth of natural flesh, a capacity to finish evenly and smoothly with a resultant splendid marbling of the lean, which is distinctive of them. Angus cattle (Fig. 110) are heavy on account of their compact build, but they are not, as a rule, as large as either Short-horns or Herefords. Their form is most characteristic ; they are extremely short-legged and have a distinctly cylindrical contour, being compact, rotund and smooth. Their naturally fine frame is amplified by an unusual muscular system, which leaves no angles or points in their outline. The head is also readily distinguished from the head of other polled cattle. The forehead is especially broad between the eyes, tapering distinctly from that point to the muzzle below, and upward to the pole, which is prominent, and sharply defined. The hide is of medium thickness, very mellow and covered with a good coat of thick, but soft and short hair. Compared with the rough coats of the other beef breeds, the Angus coat is smooth. The color should be black with no reddish or brindle cast, as was' common among some of the foundation animals of the breed. White on the under line back of the navel is permissible, but undesirable. Angus breeders guard against. 239. The Galloway. — Although the oldest and purest of the beef breeds, the Galloway cattle are the last to be bred for systematic improvement, and results have been most marked during the past decade. They have done best in this country on the northwestern ranges, where their protective coats, hardihood and rustling ability have enabled them to do well under most rigorous conditions. While both are black and polled, the breed characters of the Galloway and Angus are not difficult to distinguish. Galloways (Fig. Ill) average lighter in weight than the representatives of the other beef breeds described. Their form is less cylindrical than the Angus or Hereford, having more of the square outline of the Short-horn, but with less breadth and thickness. The head is somewhat longer than that of the Angus, but is of more uniform width, not tapering to the muzzle nor to the poll, but broad at the crown with an oval-shaped, rather than a high-pointed, poll. The ears are carried in a peculiar fashion characteristic of this breed. They are set well forward and high, and may be pointed upward and for- ward. The hide is of medium thickness, loose and pliable, and covered with a coat of hair which furnishes one of the most distinctive characters of the breed. The coat is really double, a soft, fine, mossy or furry under coat being overlaid with a long, curly, heavy hair coat, which gives them an extremely shaggy appearance with a heavy mat of curls on the forehead and locks in the ears. Hides taken when the cattle are in full coat sell at a premium on account of their value for coats, robes, rugs, etc. The color of the Galloway is black with a peculiar cinnamon tinge, especially noticeable in the under coat and the coat of new-born calves in which it predominates. Any white on the extremities or above the under line is objectionable. The first Galloways brought forward in this country were very rough, unsymmetrical individuals, especially deficient in spread of rib, and slow to mature and ripen. Some individuals of the breed still show deficiencies in these respects in spite of the great improvement that has been wrought. Prominent tail heads, heavy shoulders, with a disproportionate height between fore and hind quarters, forequarters being low, flat ribs and an absence of condition are respects in which the breed is still subject to some correction. Too much white and the presence of scurs will also count against Galloways. 240. The Jersey. — A definite scale of points having been formulated and agreed upon by the Island breeders as early as 1835, since which time great care has been taken to keep the blood lines pure, Jerseys are very uniform in breed type and character (Fig. 112). Cows weigh 800 to 1000 pounds, bulls 1200 to 1500 pounds. Their form is especially symmetrical, although distinctly dairy, and shows great refinement. The head is short, broad and deep, the face lean and distinctly dished between the eyes, the eyes wide apart and unusually prominent, ears small, fine and showing rich yellow secretion within, the muzzle black or dark blue surrounded by a light, mealy colored strip of hair and skin, the horns small, fine, white, sharply incurving, waxy in appearance and usually black tipped. The skin is thin, loose, mellow, yellow in color, showing an abundance of rich secretion Q and covered with a very fine, smooth coat of hair. Fawn is the typical Jersey color, ranging from the lightest lemon to the very dark or mulberry fawn. The darker colors are preferred on bulls. The presence of much white is generally considered objectionable in this country, although it is not mentioned in the scale of points, and some of the most meritorious animals of the breed have been spotted. of the tongue and the switch, whether light or dark. The typical udder is characterized especially by its good texture and shape, size being commendable also when the size of the cow is considered. The teats are not large, but are well placed, and the veins are especially well developed, being very tortuous in their course, knotted in appearance and entering the abdominal cavity through large and usually several openings. Some Jerseys manifest a tendency to be undersized, too fine in bone and deficient in constitutional vigor. Their udders are also sometimes too small, not well balanced in front and with teats that are too short. Distinction is usually made in this country between the Island and the American bred types of Jerseys. The former is characterized by much more symmetry and more rugged appearance but of less uniform type. 241. The Guernsey. — While also native to one of the Channel Islands and derived practically from the same foundation, the Guernsey differs in many essentials from the Jersey (Fig. 113). They were not bred for points nor were such early efforts put forth to render them especially productive. They are, therefore, larger and plainer, of more substantial appearance, the cows weighing about 1000 and the bulls 1500 pounds ; their form is indicative of dairy capacity, but is less symmetrical and refined and shows greater variation than that of the Jersey. The head is longer, with a comparatively straight face line, no dish, although the orbits are raised with unusual prominence ; the muzzle is flesh or cream colored, a smutty appearance not being permitted, and the horns are medium sized, amber colored and symmetrically shaped. The skin affords one of the most striking features of Guernsey breed type in its rich, yellow color and the abundance of its highly colored secretions. This color is manifested wherever the skin is denuded of hair, as about the eyes, under the tail, on the udder and teats and even in the appendages of the skin, as the horns and the hoof, which are also of the deep amber hue. Guernseys are most commonly of a reddish fawn shade, broken by a considerable amount of white, although solid colors of other shades of fawn are not rare. The udder of the Guernsey cow is of good size, shape and texture with large teats, and veins to correspond. The lack of uniformity in shape already referred to in the description of the cows is even more noticeable in their udders, fore udders especially being deficient, with all four quarters cut up in many individuals. 242. The Holstein-Friesian. — This lowland race of dairy cattle reflect in their great size, their open frame and their enormous capacity both to consume and to produce, the environment under which they have been developed. They are much the largest of any of the dairy breeds (Fig. 114), the cows weighing from 1200 to 1500 pounds and the bulls 2000 pounds or over. They have a most ca- pacious but milky form, frequently standing on longer legs than representatives of the other dairy breeds. The head is the longest and leanest of any, with comparatively small fine horns ; the skin is of medium thickness, loose and pliable, showing an abundance of highly colored secretion and covered with a coat of soft hair. The color is black and white, more or less of either. Red and white, while not uncommon in Holland, is not acceptable to the registry association in this country. very large and voluminous in accordance with its productive capacity, which in quantity surpasses any. The veins are also large and tortuous and the tteats match the udder in size. Some Holstein-Friesians are deficient in dairy temperament, showing a disposition to be beefy. Also heavy hides, drooping rumps, too pendant udders, which in 243. The Ayrshire. — Representatives of this breed, created by the Scottish tenant farmer under conditions that called for thrift and hardihood, are of medium size, cows weighing 1000 pounds, bulls 1500 or more. Their form is the most symmetrical of any of the dairy breeds (Fig. 115), although it shows much less refinement than the Jersey, and Ayrshire cattle are of very uniform type. They lack some of the angularity which characterizes the dairy breeds, although the most typical individuals give no suggestion of beefiness. They are more short legged and compact in body than is usual in dairy cows. The Ayrshire head is very characteristic ; it is of medium length and width, not especially fine, but surmounted with long, strong, symmetrical, white horns inclining generally upward, forward and outward with considerable spread, and a peculiar backward turn at the tips. The hide is of medium thickness, mellow and pliable, the secretions of a rich yellow or brownish color and the hair coat fairly heavy but fine. The most typical Ayrshire color is white and a peculiar red with a brownish cast (wine colored). The old-fashioned Ayrshire was more often red with white spots, while the more approved type now is white with red spots. The red is sometimes brindled, but this is undesirable. The udder of the Ayrshire is one of its most distinctive features. In shape, especially in fore udder development, and in texture it is unsurpassed, while its size is greater than at first apparent, on account of the snug manner in which it is suspended against the abdominal wall. The teats are rather short but well placed, the floor of the udder being remarkably level, on account of the even development of all four quarters. Short teats are the charge most frequently brought against this breed, although some udders do not have sufficient capacity and some cows are undersized. 244. The Brown Swiss. — This breed is descendant from a very old race of cattle in the mountains of Switzerland. They have been generally considered a dual- clared them a dairy breed. They are of medium size, bulls averaging about 1800 pounds in weight, cows 1200 pounds (Fig. 116). Their form is characterized by a prominence of frame, as shown in the bone of the head, shoulders and cannons. They are lower set and less angular than the other dairy breeds. The head is long, broad and dished between the eyes, the horns rather short and flat, directed outward and upward with black tips. The hide is of more than usual thickness, but soft and pliable. Color is a peculiar shade of brown or brownish fawn, varying from light to dark, with a light tuft at the poll, inside the ears and along the teats. Coarseness of bone in head and shoulders, and an inclination to be beefy are rather uniformly noted in this breed. - 245. The Dutch Belted (Fig. 117). — Of Dutch origin, but selected for the distinctive color markings, the Dutch Belted cattle are smaller than the Holsteins, cows weighing from 900 to 1300 pounds, and bulls up to 2000 pounds. They are of well-marked dairy form ; heads are long and slightly dished, with long, fine, spreading horns, and dark tongues. Color is most distinctive, being black with a clearly defined white belt passing completely around the body, wide enough to just miss the shoulders in front and the hips behind, and showing no irregularities in outline. The udders are of good size and well developed. and the beef propensities of the Norfolk stock, is characterized by a uniformly red color, polled head and the capacity to produce milk in large quantity and yet retain the beef form in fair degree. They weigh 1200 to 1500 pounds for cows, 1800 to 2000 pounds for bulls. The form is that of the dual-purpose type. The head is of medium width, dished between the eyes and well finished with a prominent poll. The hide is loose, mellow and pliable even though of medium thickness, and the hair coat is fine, though abundant. The color is some shade of red, the cherry red being preferable to either the lighter or the darker shades. White is permissible in the switch, on the udder or along the under line as far as the navel only. The udder is usually well developed for so beefy a cow, but it lacks balance, the forequarters frequently being developed. The tendency, already noted, for dual-purpose cattle to deviate to one or the other extremes is responsible for a lack of uniformity in the type of the Red Polled. They are all other polled breeds. 247. The Milking Short-horn (Fig. 119). — This is a family within the breed, there being a rather sharp distinction between the blood lines of Milking Short-horns and the regular or beef Short-horns. The former are largely descendant from a Bates foundation. They have the general Short-horn character but more of a dualpurpose form. THE TYPES OF SHEEP FLOCKS of domesticated sheep, Ovis, species musimon, or ammon, are referred to in the very earliest records of husbandry. They were kept, however, for their fleeces, the evolution of the mutton sheep having been accomplished at a comparatively recent date by the English husbandmen contemporary with or subsequent to Bakewell. Sheep, being ruminants, have an economic importance similar to that of cattle but they fit into a niche which cattle do not fill. Sheep are much better rustlers, consume many weeds and grasses which cattle refuse, graze closer, and therefore do fairly well on rough, unproductive lands, where cattle could not subsist. They are also natural gleaners and much that would otherwise be waste, in stubble fields, may be saved by turning in sheep. Then they have the advantage of maturing and reproducing at an earlier age than cattle. The prevailing high price of beef has materially increased the consumption of mutton. This and the low price of wool have resulted in a much better grade of mutton being offered to the consumer. Sheep are now much more generally mutton bred, fed to a higher degree of ripeness and sold as lambs or yearlings. 248. Types of sheep. — While every sheep may yield both a mutton carcass and a fleece the two products are not correlated, and both are, therefore, seldom secured, in equally high degrees of excellence, from the same individual. As a rule, the sheep with the best mutton carcass shears a comparatively poor fleece, while the sheep that grows the greatest amount of finest wool is not wholly acceptable to the butcher, dressing out, with excessive waste, a light, ill-shaped carcass of low quality mutton. Hence, there are two distinct types of sheep, one grown for its carcass, in whose case the wool constitutes a by-product, and the other, kept primarily for its fleece and having a butcher value analogous to that of the dairy cow. Sheep of the former type are in the majority, however, even their fleeces supplying the bulk of the wool that is marketed. It is not profitable under present conditions to maintain flocks for their fleeces only, as used to be extensively practiced. MUTTON SHEEP The mutton wether is as close an analogy for the beef steer, already described, as it is possible for a sheep to be. Mutton and beef may be regarded as contemporaneous before the meat eaters of the world. 249. Production. — Nearly all of the mutton dressed is consumed fresh, therefore primeness in the carcass is especially desirable. On account of their lesser size, mutton carcasses are most commonly handled entire by the wholesaler, neither split into sides nor quartered, as in the case of beef. Preference for lamb is shown in this country almost to the exclusion of a sheep carcass of any other age. From two thirds to three fourths of all the sheep slaughtered here are lambs, while the Briton appreciates, as well, the flesh of a prime yearling wether. Lamb can be distinguished from mutton by the relative sizes of the carcasses, by the softer consistence of both FIG. 120. — Mutton carcass cuts. 1, 2, saddle; 3, 4, 5, rack; 1, 2, 3, long saddle; 2, 3, 4, 5, body. 1, leg; 2, loin; 3, short rack; 2, 3, back; 4, breast; 5, chuck; 4, 5, stew. (Illinois Bulletin 147.) R 241 lean and fat, a somewhat lighter color and the incomplete ossification of the so-called " break " joints of the knees and hocks, viz., the union between the centers of ossification in the end and the shaft of the forearm and lower thigh bones, respectively. The division of the carcass is shown in the accompanying diagram (Fig. 120). 250. The mutton carcass cuts (Fig. 120). — The mutton carcass is not usually split at first but instead is divided into two transverse halves, a saddle and a rack, the cut being made between the twelfth and thirteenth ribs. The posterior or back half, the saddle, is subsequently divided into the leg of mutton and the loin, the forward half or rack into the short rack, stew and breast. 251. The saddle, which weighs slightly less than the rack, is cut at the point of the hip or margin of the loin into the legs of mutton, which are afterward separated and trimmed, and the loin, the former being about twice as heavy as the latter. 262. The rack, counting forward ten ribs from the saddle end, is cut between the second and third ribs. The upper part of this section of the rack constitutes the short rack, the lower part the breast, the line of division being more or less arbitrarily determined, as in the steer. The short rack represents from two thirds to three fourths the value of the rack, although but about two fifths its weight. The balance of the carcass, including and in front of the second rib, is the chuck, or shoulder and, with the breast, is designated the stew. The highest priced cuts are taken from the short rack (rib chops), the leg of mutton, the loin (loin chops) and the stew, in the order named. Sheep dress 45-63% of their live weight, yearlings averaging a higher percentage than lambs. 253. The mutton type is simply the block standard applied to sheep (Fig. 121). The low-set, wide, deep, symmetrical individual is the one that does best for both butcher and feeder, furnishing the highest percentage of the most desirable parts of the carcass with least waste in killing to the former, and insuring, to the latter, most economic production of such an acceptable butcher carcass. 264. Conformation (Fig. 122) . — Head short, broad and deep, a large, full, dear eye, broad muzzle, large nostril, fine, well-shaped ears, nicely poised and carried. The size and shape of the head also whether covered with wool or hair, and the carriage of the ears is a matter which involves the breed as does also the presence or absence of horns. The horns of the horned breeds should be strong, or fine, depending upon sex, of good texture and symmetrical in FIG. 122. — Points of the sheep. 1, head; 2, neck; 8, shoulder vein; 4, shoulder; 5, brisket; 6, foreleg; 7, chest; 8, ribs; 9, top of shoulder; 10, back; 11, loin; 12, hip; 13, rump; 14, tail ; 15, giggot or leg of mutton; 16, hind leg; 17, flank; 18, belly; 19, foreflank ; 20, twist. size and shape. The neck desired is short, thick just back of the poll and begins there to swell into the width of the shoulders, being especially full in the neck vein. Typical shoulders are broad, not prominent, but closely laid in, and well covered with flesh, both at the side, where they are apt to be bare, and over the top, where they are often too open, that is, having too much space between the tips of the shoulder blades and the spine ; the back straight, strong, broad and especially thickly covered with flesh ; the ribs well arched and deep, especially the forerib, the crops so well filled as to be even with the sides of the shoulders ; the chest deep, full, broad on the floor, and square at the brisket ; the loin broad, and thickly fleshed, this region being most frequently bare; the hips broad, level, smooth and not too prominent ; the rump long, level, bro'ad and smooth, especially at the dock, where there may be an accumulation of blubbery tallow ; the leg of mutton broad, deep and thick, the twist full and well let down in the seam ; the legs short, straight, pasterns and hocks strong, the sheep standing well up on its toes, and having straight hind legs. 255. Quality in the sheep not only determines the quality of the meat, as in the case of cattle and hogs, but of the fleece as well. It is also an important factor in dressing percentage, as it controls the waste to a considerable extent. Quality is indicated by a refined head and ears, smooth shoulders and hips, clean-boned joints and cannons, fine hair on the face, ears arid legs, fine fleece and a trim under line. 256. Condition. — Fat contributes to the primeness of a cut of mutton or lamb about as much as it does to beef, although the mutton carcass, while somewhat fatter, does not naturally marble quite so nicely as the beef carcass does, and tallow is less nutritious, digestible and palatable than suet. The most acceptable butcher condition is indicated by a uniform covering of firm, but not hard, flesh, showing especially at the dock, the neck and along the back, with no bareness of loin or rib, nor any accumulation of soft fat in the foreflank, which has " slipped " from the ribs above, nor at the tail head, on the back rib, or the margin of the loin, where rolls appear. WOOL SHEEP The fleece was the first animal product to be improved by selection and breeding, and its improvement antedates the era of modern husbandry by centuries. The royal robes of the ancient nobility were woven from wool that would compare favorably with that from our modern flocks. The development of the mutton breeds, on the other hand, was begun less than 200 years ago. Prior to 1893 wool growing was one of the most important livestock industries in this country, and American Merinos were exported in large numbers to Australia, South America and South Africa. Subsequent reduction in the price of wool and an advance in the demand and the price paid for mutton resulted in a reversal of patronage and a great diminution in the fine wool flocks in this country. 267. Production. — The fleece, originally furnished to the sheep in amount and character sufficient only for its protection, has been increased in quantity and improved in texture until it may actually be a serious burden both to bear on account of its weight and to endure on account of its warmth. The annual fleece may constitute as much as one fifth of the sheep's weight, and the total amount of wool produced in the sheep's life may far exceed the weight of its body. Sheep are classified, on the basis of fleece, as long wool, middle wool and fine wool. Fleeces of the first two classes are shorn from sheep of mutton form, while the fine wool sheep are devoted to wool production, primarily. 268. The classification of wool. — Market wool is classified according to the length and strength of its staple and consequently the material into which it can each of which there are different commercial grades. 259. Clothing. — Clothing wool is of fine, short staple, about two inches in length and goes into the highest grade of woolen cloth. Clothing wools are graded on their quality into Picklock, XXX, XX, X, No. 1, or one half blood ; No. 2, or three eighths blood and No. 3, or one fourth blood. 260. Delaine wool is fine, but longer than clothing, two to three inches, of sound staple and is used in the manufacture of delaine cloths. Delaine wools are graded as fine, medium and low. 261. Combing wool is characterized by the length and strength of its staple, being at least three inches in length and strong enough to withstand the combing process. It is made up into worsted goods. Such a long wool is naturally coarse, the finest grading only No. 2 or three eighths. 262. The type of the wool sheep grown to-day is much less extreme in form than the more distinctly wool, and wool only, type of a quarter of a century ago. The relative reduction and increase in the price of wool and mutton, respectively, has led to a demand for better mutton, even in wool sheep, so that the common source of the finest fleeces now is, in reality, a dual purpose sheep. As a result of the inevitable law of correlation, under which mutton and wool are almost as much opposed to one another as beef and milk or lard and bacon, the old-fashioned, fine wool sheep were the extreme opposite of the mutton sheep in form. They were small, with long legs, heads, necks and bodies, of an angular, rather than a blocky, form, having light quarters, peeked ends and flat ribs. Sheep of this type not only grew wool of the finest staple, but also in great amounts. They were covered from tip to toe, well wooled under the belly and in the arm pits and groin, where most sheep are comparatively bare. In addition, they presented the maximum skin area from which to grow the fleece by virtue of the elaborate system of folds into which their skin was thrown. In response to modern demand this form has been increased in size, and its angularity has been amplified into rotundness, at least, insuring not only more of a carcass but greater constitutional vigor. The folds and wrinkles have been almost completely bred out, fine wool sheep being classified at the present time as to the presence or absence of wrinkles. 263. Conformation. — Attention has already been directed to the fact that the market demands an acceptable mutton carcass from every sheep, even though they may be primarily wool producers. • The conformation of the wool sheep, therefore, follows that already described for the mutton sheep as far as is consistent with fine wool production, and does not depart therefrom in the same extreme degree as does the dairy cow from the beef steer. It is generally characterized, however, by being more sparely furnished with natural flesh and by having less breadth and fullness of parts than is characteristic of the mutton sheep. 264. Quality. — There is naturally associated with the fine fleece by which this sheep is distinguished an unusual degree of refinement. They are not large, and while somewhat unsymmetrical in shape they have fine heads, clean bone, delicate, pink skins, and what hair there is on the tip of their noses and legs matches, in fineness, the fleece with which they are covered. length and density which, however, are not correlated but opposed, thus making the longest fleece the most open, as a rule. There should be sought, therefore, such a balance between the length of staple and the density with which they grow, as will insure neither being sacrificed to the other, the maximum of both being secured. 266. Quality involves primarily the texture of the individual staple, which, in turn, is in proportion to the amount of crimp. The finest, shortest, densest fleeces have the closest crimp, while the longest, coarsest, most open fleeces have the crimp enlarged to kinks or ringlets. The finer wools, of more delicate texture, are usually possessed of a distinct luster, a feature of the fiber itself and independent of either yolk or discoloration. 267. Condition of the fleece depends upon soundness, i.e. whether or not the fiber has made a regular uninterrupted growth, as shown by continuous crimp of uniform degree, and no break in the staple itself; yolk, the secretion of the skin, through the wool, which should be sufficiently abundant to indicate normal activity of all vital functions of the sheep, yet not excessive to be scoured out prior to manufacture, nor dry and flaky, which indicates some constitutional disturbance, usually resulting from improper feeding ; softness, the resistance offered by the fleece to pressure of the hand, as opposed to harshness, in which case the fibers do not yield, but grate against each other ; purity, which refers to the absence of such foreign matter as sand, cockle burrs and hay seed, also kemp, a vestige of the old hair coat which sometimes makes its appearance in coarse fleeces and renders them of less value for manufacture, because the kempy fibers do not take the dye ; and brightness, as opposed to discoloration, the natural fleece being white, or cream tinted if there is much yolk in it, while any discoloration tends to darken it. The brightest fleeces are taken from sheep that are kept under the best systems of care and management, while the sheep that are grown on the open range, for instance, have their fleeces badly soiled. 268. Method of inspection. — Sheep present difficulties, on account of their fleeces, which require special means of making accurate observations and determinations of their conformation. Their form is so effectively obscured by the fleece, which may be further complicated by the shepherd's clever trimming, as to make most careful handling necessary. The hands should not be depended upon altogether, however. The lines, general contour, length and strength of the legs, the width between them and the style and carriage of the sheep can best be made out by viewing them from a little distance. Then thorough handling must be resorted to in order to verify conclusions arrived at by looking the sheep over. It is especially important that the handling should be systematically done, in order that omissions and repetitions may be avoided, and a definite and accurate idea of the sheep formed. The usual system is to approach the held sheep from the left side, and with the right hand over the back of the head, part the lips with the first and second fingers to determine the age ; then look it full in the face, noting the proportions, dimensions and features of the head, after which span the neck with the thumb and forefinger of each hand to find out its fullness and from this its length and the manner in which it blends into the shoulders. The breadth and compactness of the shoulder is felt by the right hand, crossways over the top of the shoulder, when, without changing this position, the depth of both chest and foreflank can be made out by the left hand, first at the point of the brisket, noting, at the same time, whether it is full or sharp, then back of the elbow, fullness as well as depth at this point being made out. The right hand next feels along the spine from the shoulder to the dock, to get the straightness and the thickness of covering of the back and loin, with the levelness and fullness of the rump. Passing back to the shoulder with both hands, measure and feel the width, covering and smoothness of the shoulders ; slipping the hands backward to find the spring of forerib, then again the width and covering at midrib, the width, as measured between the hands, and the thickness, as detected by the thumbs, of the loin, the length of the rump, the left hand remaining at the margin of the loin, just in front of the hip, while the right is carried back to the point of the buttocks. After this the width and fullness of the rump and finally the depth and fullness of the leg of mutton are measured by inclosing it between the thumb and first finger of one or both hands. 269. Examination of the fleece. — The fleece is examined by parting it at one of the natural openings to ascertain the length and fineness of staple and the condition of the fleece and skin. Texture and softness are best detected by pressing down upon the fleece with the flat hand. The fleece should be opened at at least three points ; namely, over the heart, at midrib, and on the outside of the thigh where it is finest, medium and coarsest, respectively. The wooling over the face, legs, and belly should be given due consideration, especially in breeding classes. In judging fine wool sheep, it is customary to set them up on their hind ends, thus exposing the fleece of the belly, arm pits and groin to a better view. bouillet 270. The Southdown. — This is the oldest, purest and smallest of the Down breeds and has the distinction of representing the ideal of mutton form and quality (Fig. 123). It is one of the smallest breeds, rams weighing 175 pounds and ewes 135 pounds. The form is the lowest down, most compact, broadest, deepest and most thickly fleshed, of any sheep. All the features of block type and conformation, i.e. the short, broad head, short, full neck, blending with broad, but compact and smooth shoulders, broad, thickly covered back and loin, and a wide, full, and deep leg of mutton, are especially well marked in the Southdown. The head is extraordinarily short, wide between the eyes, and rather fine, the ears short, small, pointed, and covered on the outside with little tufts of wool; the face below the eyes is bare of wool, and covered with brownish gray hair, while the cheeks and forehead are wooled over. The fleece of the Southdown is very dense, but, being short and comparatively free from yolk, the clip is light, six to eight pounds, and grades as one half and three eighths. It is very evenly distributed, however, except on the legs, which are covered with hair similar to that on the face. adaptable and popular breed of sheep in this country. It is chiefly characterized by the wooling of the head and legs and by its stylish carriage (Fig. 124) . The Shropshire is intermediate in size, being larger than the Southdown but smaller than the Oxford and Hampshire, the rams weighing 225 pounds and the ewes 150 to 160 pounds. The form is distinctly mutton, yet less extreme than in the case of the Southdown. The head is completely wooled over with a hood, only the tip of the nose being exposed, which is covered with very heavy, dark brown hair ; the ears are rather stubby, but pointed, and covered on the back with fine tufts of wool. The head is carried higher and more alert than in most other breeds. The fleece is most typical of the middle wool class, combining quality with quantity, and it is evenly distributed over the body, even down to the hoofs. Shropshire fleeces weigh eight to twelve pounds. Patches of black or brown fleece, especially about the head, dark skins and scurs are the most common causes of criticism of the Shropshire. It is the largest of the Down breeds, the rams weighing from 250 pounds to 350 pounds and the ewes 180 pounds to 275 pounds. The Oxford is not only heavy, but is large in frame and stature. The form is of the most approved mutton type, the development of back, loin and hindquarters being especially heavy. The head is longer than that of the Shropshire, which the Oxford resembles most, and there is no hood, the head being wooled only down to the line between the eyes, the balance of the face being covered with grayish brown hair; the ears are longer -and finer than those of the Shropshire, and are covered with brown hair instead of wool, as are also the legs. The fleece is the longest and coarsest of the Down breeds, averaging about 10 % heavier than that of the Shropshire. It is sometimes too coarse and open, and may show dark jected to. 273. The Hampshire. — This old breed is characterized by its size, 250 pounds for rams, and 185 to 195 pounds for ewes, and rugged appearance, indicative of the rapid and early growth in the lambs, for which the breed is most noted. Hampshires (Fig. 126) are of superior mutton form but are big boned, as shown in the head and legs, and they are, therefore, prone to coarseness. The head is very typical, being wooled only on the forehead and cheeks, while the face and ears are covered with very dark brown or black hair; the head itself is large and marked by a distinctly Roman nose ; the ears are also large, carried straight out from the head and inclined to lop, if at all coarse. The fleece is inferior to that of most of the other Down breeds, being short, not dense and fine, nor well distributee^ ajid yielding lightly. The Dorset-horn. — This is another one of the old, pure English breeds (Fig. 127). The size is medium, rams weighing 200 pounds and ewes 160 pounds. The form is similar to that of the Shropshire but is less symmetrical. The head is characterized by the presence of horns which curve forward, closely, in spiral shape ; the face and ears are covered with fine white hair, although there is a foretop of wool. The fleece is medium both as to quantity and quality, being short, lacking somewhat in density, unusually free from oil, and not evenly distributed, showing a tendency to be bare on the belly. Average fleeces weigh six to seven pounds. Dorset ewes make exceptional mothers, being deep milkers and prolific. evenly distributed. 276. The Cheviot. — Cheviots have been bred for centuries in the Cheviot Hills of the Scotch border, although outside this district to which they are native they have received less consideration than some of the other breeds. The Cheviot (Fig. 128) is of medium size, rams weighing 200 pounds, ewes 150 pounds ; it has a good mutton form, although hardly equal to that of the Down breeds, and yields an excellent fleece of pure white wool. The head is broad between the eyes, which are very bright and alert, the ears are carried erect, and both head and ears, as well as legs, are covered with fine white hair, no wool, the fleece ending abruptly with a " ruff " just back of the ears and about the throat. The Cheviot fleece is somewhat longer and consequently more open than that of the Down breeds, classing as half combing, and is snowy white instead of the heavy gray tinge noticeable in most Down fleeces. The clip is light — four and one half to five pounds of washed wool. Cheviots dress well and cut a very good grade of mutton. They have a very alert carriage. 276. The Leicester. — This breed is of greatest historic importance on account of its having been the object of Bakewell's efforts, and having been the first breed improved it was most extensively used in the improvement of other breeds. Its early development is reflected in the refinement and uniformity of individuals of this breed. Leicesters (Fig. 129) are the smallest of the three long wool breeds, rams weighing 225 to 250 pounds, and ewes 175 pounds to 200 pounds. Their form is square in outline, although of rather high station, and is characterized by a peculiar roundness and prominence of the rump, suggestive of a torpedo stern. The head is broad and prominent between the eyes, tapering toward the muzzle with a slightly Roman nose, in spite of the refinement of bone ; the ears are fine, well poised and, like the face, are covered with short, white hair, with an occasional black spot. The expression of the Leicester countenance has been described as especially " sheepy." The fleece is long, having a five to six inch staple, very fine, white, falls in ringlets and weighs nine to eleven pounds. The hoofs and lips are black. Uneven and excessive fattening and bodies bare of fleece on the under side are the common deficiencies of this breed. Classifications make no distinction between Bakewell or English and Border Leicesters, although the latter are in the majority. They may be differentiated by the white face, free from wool, of the Border Leicester and the bluish face and tuft on the head of the English Leicester. The Border type is also more rugged looking. 277. The Lincoln. — Bred originally in the fen country of Lincolnshire, where the environment was conducive to size, this breed is still, even after the refining influence of Leicester crosses, the largest of the sheep breeds (Fig. 130). Rams weigh 200 to 250 pounds, and shear an exceptionally heavy fleece, weighing fourteen to eighteen pounds, on an average. In addition to their scale they have a square, massive, mutton form. The head is characterized by a tuft of wool on the forehead which is readily distinguishable from the bare forehead of the Leicester and the forelock of the Cotswold. The face and ears, as well as the legs below the knees and hocks, are covered with white hair. The fleece is the longest of any, not less than eight inches in staple, is moderately fine, white, lustrous, and unusually sound. A tendency to coarseness of both mutton and wool is noticeable in this large breed of sheep. 278. The Cotswold. — This is a very old breed, native to the Cotswold hills in Gloucestershire, England. The original Cotswolds have been much improved in the way of a more compact form, greater symmetry, weight, early maturity, style and fleece (Fig. 131) . Cotswolds are among the largest of the breeds of sheep, weighing 200 to 250 pounds. They are upstanding, but of good mutton form, showing special strength of back and loin. The head is very FIG. 131. The fleece of the Cotswold is in the combing class, being ten inches or more in length of staple, open, arranging itself in locks, but yields heavily, sixteen to eighteen pounds. It should be evenly distributed all over the body except the face. sentatives of this breed. 279. The Merino. — This group embraces all the fine WQO! breeds and their subclasses, the name, like the original stock, being derived from Spain. Merinos are most i Morino ram. comprehensively classed as American, Delaine and Rambouillet. Being essentially wool rather than mutton sheep, the Merinos are, as a class, quite different in size and form from the breeds already described. weighing from 100 to 175 pounds, the ewes 80 to 100 pounds. Their form is light, angular and lacks symmetry when compared with that of the mutton breeds. The head is small, completely wooled over except at the tip of the nose, and surmounted by heavy, sharply incurving, spiral horns in the male, while the ewes have none. The fleece is short, but very dense and fine, being two and one half inches in length and shearing from twelve to twenty pounds. The amount of yolk which it contains causes the fleece to soil on the surface, giving the " Black Topped " effect. The Merino's skin is a most delicate pink. The fleece completely covers the sheep from tip to toe, and the normal surface area is increased by the skin being thrown into folds and wrinkles, there being from three to five folds on the neck, showing most on the lower side, two to three at the elbow, with wrinkles on the side, and across the hips, and folds around the tail and across the thighs. Merinos gestion of wrinkles about the neck. Delaine (Fig. 133). These are distinguished from the American Merinos by greater size, rams weighing 140 to 200 pounds, and ewes 100 to 150 pounds, and a better mutton form, the smoothness of which is enhanced by the almost complete absence of wrinkles (Class C). The head may be either horned or polled, depending upon the numerous subfamilies within the breed. The fleece is not so fine and crimpy, nor so rich in yolk as that of the American, but the staple is longer and stronger, and the fleece weighs from nine to eighteen pounds. Rambouillet. This is the largest of the Merinos, and combines so much of the fine wool character with size and mutton form as to constitute a dual-purpose sheep (Fig. 134) . Rams weigh 175 to 180 pounds and ewes 140 to 160 pounds. This sheep is rather upstanding, but has a well-formed mutton body. The head is of good size, with a strong nose, and usually, though not always, large spiral horns in the male, though none in the female. The fleece completely covers the sheep as in the case of the other Merinos and is fine, dense and white, comparatively free from an excess of yolk, has a three-inch staple, and shears from ten to fifteen pounds. Evidence of constitution and hardiness should be a feature of this breed. THE hog (Sus scrofa) is a monogastric, omnivorous animal with an especial predisposition to obesity and a propensity for making extremely rapid gains in weight. Unlike the ruminant, the hog is ill adapted to the consumption of rough foodstuffs but requires his ration in concentrated form. His scavenger habits render him an indispensable party to the great industry of marketing corn through cattle, as it is practiced throughout the middle western United States, and he furnishes a most profitable outlet for the dairy by-products of the eastern United States and southeastern Canada. Types. There are two distinct types of swine, fat and bacon, each directly opposed to the other in the character of their products, their ration requirements and, consequently, in their forms. THE FAT HOG There is no more efficient means of transforming corn, the staple crop of the American farmer, into lard and a fat, energizing meat upon which the great masses of laboring people depend, than the fat hog. 280. Production. — The fat or lard hog supplies fresh pork for roasts and chops from his ribs and loin, cured pork products, as hams, shoulders, and bacon sides, lard, and such odd products as sausage, scrapple, head cheese, and pickled feet. On account of the lard rendered, and the fact that so much of the carcass is demanded in the cured state, there is greater uniformity in the relative values of the different parts of the carcasses of hogs than of cattle or sheep. The carcass is also more completely utilized for higher priced products, and dressing about 80 % of the live weight, the butcher is enabled to pay a higher proportionate price to the producer than he pays for beef and mutton and still sell, at a profit, for a lower price to the consumer. There is also less discrimination in the matter of quality in hog carcasses. Weight really has more to do with the grading of hog carcasses than have texture or color. The weights most desired range from 200-400 pounds according to the class of carcass the hog will dress out. 281. The hog carcass cuts. — The simplest division of the hog carcass makes four general sections of it first, the hams, the middle piece, the shoulders and the head. Then each is further subdivided after being split in half. 282. The hams are separated from the rest of the carcass a short distance in front of the point of the hips and are afterward trimmed more or less. 283. The middle piece, extending from the hams to the shoulders, includes the pork loin, with tenderloin, from which chops and roasts of fresh pork are taken, the side, from which the bacon strip and sparerib comes, and the fat back. 284. The shoulder, separated from the middle between fourth and fifth ribs, embraces the picnic or California ham, consisting, more in detail, of the picnic butt and cheese and scrapple. 285. Lard is yielded by the fat back, the clear plate, the leaf lard or internal fat and the trimmings, amounting in all to from one tenth to one third of the weight of the carcass. type that is also characteristic of the beef steer and the 136. It is a low, broad, deep form, that is productive of greatest weight in a given compass, earliest maturity, the most rapid fattening in the feeder, the highest dressing percentage, and the best yielding carcass. 287. Conformation (Fig. 137) . — The head of the lard hog, like that of all other block animals, is short, broad and deep, the snout being comparatively short, with breadth marked particularly between the eyes and depth through the jowl ; the eyes large, the eye of the hog being naturally small and deep set ; the ears of medium size, pointed and thin, carried well up, not lopped, although these features involve to a large extent the breed of the hog, and close set at the poll ; the jowl, the region of the lower jaw, full and deep, blending well with the lower part of the neck, but trim, giving no evidence of being pendant or flabby; the neck hardly definable, it really constituting only the FIG. 137. — Points of the hog. a snout; b, ear; c, neck; d, jowl; e, shoulder ; /, back ; g, loin ; h, rump ; j, ham ; k, side or ribs ; I, flank; m, belly; n, fore flank; o, foreleg; p, hind leg. union of the head with the body, and consisting of but two dimensions, width and depth, without appreciable length, as far as such a thing is possible in an animal structure ; the top line making a sharp curve upward from the poll to the top of the shoulders, while the jowl is continued into the point of the shoulder and the brisket; the socalled shoulder vein, the thickest part where the neck blends into the shoulder, especially full; the shoulders not having greater width than is carried throughout the rest of the hog, but broad and compact on top, well laid in and smooth on the sides, indicating fine bone, thickly covered; the chest deep, wide, full on the floor and at the breast, with no constriction just back of the shoulders nor between and behind the forelegs ; the back broad, flat and thickly covered, carrying a maximum of lard and meat and well supported with a slight arch ; sides as long and deep as is consistent with width, the primary essential in the lard hog. Since side meat makes bacon, and the better grade is from the upper part of the side, length is more important than depth, although as much depth of side as possible, so long as it comes from length of rib and not from the weight of the contents of the abdomen, is desirable. Another indication of side meat of the right sort is the smoothness, the absence of wrinkles and creases, and the firm, rather than flabby, appearance. If the back is broad and the rib is well arched the side will be more or less at right angles with the back and will carry well out to the line established by the shoulder in front and the ham behind. If the back is narrow and the rib flat, there will be no sharp demarcation between the back and the side ; the side will be deep but pendant and the hog will fall away directly behind the shoulders and continue narrow to the hindquarters. The loin should conform to the back, already described, in being broad and thickly covered, the flank deep and full enough to make the side carry out evenly and the under line straight ; the rump broad, long and as level as possible, there always being some droop of the rump corresponding to the sharp curve at the top of the neck which is followed more or less by the whole top line. The maximum weight in the hams, the most valuable part of the hog carcass, is secured by the breadth of rump being continued down into the thighs as deeply as possible toward the hocks and ampli- fied by a fullness which makes them rounded out behind and to both inside and outside. They should, however, be firm and show development of muscle, rather than composed largely of fat, which makes them soft and flabby and requires extensive trimming before they can be cured. The essential thing, so far as the legs of the fat hog are concerned, is that they shall be sufficiently straight and strong to carry their weight through the feeding period and finally to the shambles. This latter formerly meant much more than now, as hogs were at one time driven over land considerable distances, while the trip from the farm to the car and from the car to the slaughter is comparatively short now. This matter of legs is of much greater importance in breeding animals, but it is nevertheless essential that market hogs should stand well up on their toes. Broken down pasterns, knock or buck knees and crooked hocks are the common defects in the conformation of the legs. 288. Quality in hogs influences both the texture of the carcass and the dressing percentage. It is indicated by the size and shape of the head and ears, the smoothness of the shoulders, the character of the bone in the cannons and joints, the amount, texture and course of the hair, the trimness of the jowl and the under line, and the general refinement of the hog throughout. 289. Condition. — Most hogs are marketed at weights which make them less mature at slaughter time than the majority of cattle are. They are, therefore, fattening as they grow, which is equally true of cattle only in the case of baby beeves. Condition, comparatively speaking, is of less degree, so far as actual ripeness is concerned, although a thin hog is, in reality, fatter than a finished steer because it is more his nature to be so. Furthermore, for the same reason, the butcher hog is less apt to be overdone than the butcher steer. Show hogs do manifest an overripe condition sometimes by " slipping " just back of the shoulders, having their sides break in folds, wrinkles or creases, or their flesh become too hard or too soft. 290. Feeding hogs. — On account of the prolificacy of the sow, the rapid growth and early marketing age of the pigs, and the danger of cholera involved in shipping hogs about, there is no such thing on the market as a feeding hog. The feeders of hogs either breed their own or secure them in their immediate vicinity. Since hogs, as a class, make so much greater proportionate gains on a unit of feed consumed than cattle or sheep do, less consideration is given to the type fed. There is, however, a great difference in the economy with which gains are made in the different individuals, as well as in the character of the carcass when finished. The type that feeds best is of the same general form that is required by the butcher, namely, low, wide and deep, early, rapid and economic production being as closely correlated with this form as are desirable killing qualities. The feeding hog should also possess quality to insure against growing a wasteful carcass, although he should not appear trim, but should show his feeding capacity by being habitually full ; constitution, as evidenced by a deep and full forerib ; and a feeding temperament. A leggy, long-headed, narrow, flat-sided, light-hammed and wild-eyed hog will be unprofitable both to his feeder in the making and to the butcher when he is finally finished. In this they differ materially from the fat or lard hogs whose carcasses yield fresh pork, lard and cured meat, one portion of the latter being bacon. This lard hog bacon, however, must be considered as a by-product of pork and lard production. It consists only of the lower two thirds of the side, between the shoulders and hams and below the limit of the fresh cuts from the back and loin; and being cut from a hog that has been bred and fed for lard the side is too soft and coarse grained to rank with true bacon. 291. Production. — The carcass of the bacon hog is split into two Wiltshire sides which are cured entire and are then all cut up for bacon. There is, however, a difference in the grade of bacon derived from the different regions of the side, that cut from the upper part and center of the strip being superior to that at the lower part and ends. Merit in a Wiltshire side is determined by weight, 160-200 pounds ; shape, — long and trim with maximum development along the back from shoulders to gammons, where the highest priced cuts of bacon are taken; consistence, which should be firm, not soft or flabby ; texture of lean, which is finer than in any other pork product; and fat, only enough to show a uniform margin one to one and a half inches wide along the back bone. Such a side can be produced only in a hog of the correct type. 292. Type. — The bacon type is characterized .by length, and all that is correlated with it, i.e. length of side primarily, with a long snout, long legs, a narrow, trim body and especially light fore and hind quarters (Fig. 138). 293. Conformation. — Being a longer, narrower hog all over, the head of the bacon hog is characterized by greater length, less width and depth, making it more tapering to the snout, lighter and neater in the jowl, with a fine and usually upright ear. The neck is much better defined than in the lard hog, being level on top, showing none of the arch from the pole to the top of the shoulders, characteristic of the lard hog, and no marked fullness of shoulder vein, but just an even thickness of medium length. The shoulders are light, comparatively straight, lengthening the back, and shortening the distance from the shoulder forward, neither sharp nor open but compact on top and especially smooth on account of their being of equal width and well blended with the back. The back may be considered the foundation of the sides, therefore its most desirable features are those which are conducive to a most acceptable side, i.e. as great length as can be had and still be carried up well with just a suggestion of an arch, width sufficient to insure ample abdominal capacity and a meaty side, yet not wide enough to predispose to a short or fat side as in the case of the lard hog, where width is a primary essential. The law of correlation is in no place more manifest than in the distinctions between a lard and a bacon hog. The rib has a peculiar turn which is responsible for the shape of back and side by which the bacon hog is characterized. It arches abruptly a short distance from the vertebral column, which it leaves at a right angle, and then continues straight in its course throughout the depth of the side, the lower end incurving again to the sternum or breast bone in such a way as to insure the greatest capacity of chest vfor the width of the hog. The result is a relatively flat back except as it is rounded by the depth of flesh, and a straight, deep side. The loin should have breadth proportionate to that of the back forward and the rump in the rear, there being a tendency in some bacon hogs to lose width at the loin ; strength sufficient to make the loin the crown of the arch of the top line, and a flank only so deep and full as to carry out the straightness of the side. The rump desired is long, comparatively level, carrying throughout the hindquarters the uniform width of the shoulders, back and loin having a rounded contour from side to side, and continued into deep, comparatively thick but smooth and tapering gammons. The shoulders, back, sides, loin and hindquarters should be covered with uniformly thick, smooth, firm flesh. There is naturally a well-marked correlation between bone and muscle, and since bacon consists more essentially of muscle than of lard, the bacon hog is naturally heavier boned than the lard hog. Quality of hair and flesh also being characteristic of the bacon hog, the bone should be smooth and clean, though ample. The extra length of legs which goes with the long body makes it especially important that they be straight, but boned lard hog. 294. Quality. — General refinement is usually more marked in hogs of bacon type, although their bone is naturally heavier. Trimness of jowl and under line, fine ears, light, smooth shoulders, tapering hindquarters and gammons, with a fine, smooth coat of hair, are indicative of the best texture of lean and even deposition of fat so essential in high class bacon. point. There is in bacon hogs, as in all other fat stock, an optimum state which constitutes ripeness, but it is quite different in degree of fatness from what constitutes ripeness in lard hogs, cattle and sheep. The condition sought in the bacon hog is that in which there has been sufficient fat deposited to show the narrow margin along the back when the carcass is split, and this fat is of the sort which gives firmness to the side, being composed largely of the solid palmatin and stearin fats rather than the olein which melts at ordinary temperatures. It should be interspersed evenly with the lean. There is difficulty hi holding this condition after the hogs have attained 200 pounds weight. 296. Feeding hogs. — Hogs grown for the production of bacon are marketed at such an early age that the feeder type concerns the breeder more than any one else. Pigs for this purpose should not only conform to the correct type but they should have constitutional vigor as indicated by a full, though not wide, chest, a bright eye and a general appearance of thrift. They are of a sort that is slower in maturing and fattening than are lard hogs, but should give promise of having no difficulty in making the required weight of 160 to 200 pounds in six to eight months. 297. The method of inspection. — Hogs of either type are rarely handled at all, the eye being depended upon almost altogether. Some judges touch the side to determine the consistence of the flesh, but even this can usually be made out by noting the lay of the hair and the presence of wrinkles. From in front, the general width, symmetry and smoothness, also the character and features of the head, and the length, the bone and the direction of the legs can be noted; then from the side and above, the length in general, the top and under lines, the station, the length and the strength of the forelegs, the head in profile, the width and smoothness of the shoulders, the breadth and covering of the back and the loin, the fullness of the forerib and flank, the length and levelness of the rump, the depth and fullness, or taper, of the hams, or gammons, as the case may be, and the straightness and strength of the legs are ascertained ; from the rear, the uniformity with which the width is carried throughout, more particularly, the width and smoothness of shoulders, the breadth of back, loin and rump, the depth of hindquarters and the fullness or taper of the ham or gammon, with the length and straightness of the hind legs, receive consideration. The opinions formed from the one side inspection should then be verified by a final look from the other side. Throughout this inspection quality, as indicated by the amount, the character and the lay of the hair, the fineness of the head, the ears, the shoulders, the cannons and the joints, the smoothness and evenness of the covering, with an absence of wrinkles, creases and folds, and a trim under line should be borne in mind. Condition also, as manifested by the general degree of fatness, the consistence and smoothness of the covering, and the trimness of jowl and under line, can be determined incident to the general inspection. Tamworth 298. The Berkshire. — The original stock of the Berkshire breed was very old, but it has been modified in both color and form to such an extent, by engrafting other stocks, as to bring the real origin of the breed within the era of general live-stock improvement, which began in Great Britain in Bakewell's time. At that, it was the first breed improved, and has been most potent in the improvement of others. The typical Berkshire (Fig. 139) represents the early improvement wrought in the breed by an exceptional degree of style, character and refinement, as well as in the uniformity with which he possesses merit, as measured by feeders' and packers' standards. The Berkshire averages a little larger than any of the other fat hog breeds, but does not attain as great size as the two leading bacon breeds, boars weighing 500 pounds and sows 400 pounds at maturity. Its form is characterized by more length and trimness of body than is usual in breeds of this type, the latter character being especially noticeable in the hams. The head is distinctive, the snout being of medium length with only a moderate dish in the face, the ear very neat, well shaped, carried erect, and the jowl full but not flabby. The color is black with six white points, but the absence of a white point is less objectionable than the presence of an irregular white patch on the body. The Berkshire has ample bone of superior quality, straight, strong legs, stands well up on his toes, and moves with a stylish carriage. He is a show hog from tip to tip. The old-fashioned, short, extremely dished face, a tendency to be leggy and to show an occasional splash of white or a sandy tint on the body are not favored by Berkshire breeders. 299. The Poland China. — This is an American breed of most composite origin, but selected and bred for pork and lard production exclusively. Poland Chinas (Fig. 140) are but little smaller than Berkshire^ and of the same color and markings, although readily distinguishable from them by their form and head. The shape of the Poland China conforms to that of the fat hog in the extreme width of body and fullness of shoulders and hams, being most characteristic, although often secured at a sacrifice of length. The head is distinguished by more length of snout, although it is very fine and tapering, with little, if any, dish in the face, and an ear that is erect two thirds of the way from the knuckle, breaking forward for the last one third of its length. The jowl is heavy in accordance with that fullness which prevails throughout the make-up of the fat hog. Poland Chinas show a marked inclination to mature early and fatten rapidly. Poland China breeders are endeavoring to meet. 300. The Duroc Jersey. — This breed, evolved from two parent stocks, the Duroc and the Jersey Red, having a local reputation in New York and New Jersey respectively, has, like most of the other breeds, been molded to a uniform type by breeding for a definite purpose, which, in this instance, was to meet the requirements of the corn belt farmer. In size the Duroc Jerseys do not differ materially from the Poland Chinas and Chester Whites, but they usually possess greater substance than the former (Fig. 141). They conform closely to the fat hog type in shape, being low, broad and deep, with very full, yet smooth, hams and shoulders. The head is of medium size; the snout of medium length, the face very slightly dished, the ears of medium size and arching gradually forward, the jowl heavy and full, like the hams, shoulders and body all through. Color is red, the cherry shade preferred, although the best shades grow lighter with age. Dark spots are sometimes seen under the belly and on the legs and too many are objected to. As a rule the bone is especially heavy. A general lack of refinement, shown especially in creases and wrinkles along the sides, has been charged against some individuals of this breed. r White boar. 301. The Chester White. — This breed, largely of Yorkshire extraction in the beginning, was formerly considered one of the three largest breeds, but it ranks now with the Poland China and Duroc Jersey in size (Fig. 142). Its form is characterized by more length than in either of the two breeds mentioned and it is not, therefore, as uniformly wide, nor as well filled in the hams as they are. The head is of medium size, the face long but straight, the ears large, falling gradually forward, sometimes in a careless fashion. Color is white, although bluish black skin spots are not unusual. The pigment must be confined to the skin, however, the hair growing from them being white, and, even then, too many spots are objectionable. toward the hindquarters. Coarseness, noticeable especially in heavy, lop ears, prominent shoulders, and a rough, curly coat of hair, is a fair objection to some individuals. 302. The Hampshire. — This breed, formerly called Thin Rind, has been classed as of both fat and bacon type, but barrows of this breed have been shown most often in fat classes. Typical representatives (Fig. 143) weigh somewhat less than those of the other fat breeds and their form is less extreme. In fact, in length and width of body and fullness of hams and shoulders they are intermediate as to type. Color is the most striking feature of Hampshire hogs, although it is not fixed by any means. That desired is a white belt clearly defined on an otherwise black body. The belt is sometimes missing, however, solid black colors occurring in litters where some of the pigs, like the parents, are belted. Quality is usually conspicuous in Hampshires, they bejng smooth and fine. 303. The Yorkshire. — The Large Improved Yorkshire is the only representative of this breed with which American hog growers are much concerned. This is one of the oldest breeds of swine, and earliest references to it indicate that it was then, as now, notable for size, boars and even sows weighing 1000 pounds (Fig. 144). Yorkshire form is strictly bacon, being characterized by length and depth of side, balanced by an absence of width and fullness throughout, the neck, shoulders and hindquarters being thin, light and tapering. The head is of medium length, the snout only slightly dished, not turned up, the ears large but fine, shapely, well set and carried erect, the jowl muscular but firm. Color is white, bluish spots in the skin only being permissible but rather objectionable as in commonly noted in this breed. 304. The Tamworth. — This is also a very old and probably pure breed, the original characters of which have been perpetuated and modified along the line of bacon production. After the Yorkshire, this is the largest of the breeds. Its form is even more extremely rangy, long and narrow than the Yorkshire, with a very light neck, jowl and hindquarters (Fig. 145). The head is long and tapering, the longest of any breed, the snout straight, there being little or no dish in the face, the ears very large, but well pointed and thin. Color is cherry red, with no spots, but it is inclined to darken rather than grow lighter with age. This breed is especially active and strong on its legs. Extremes of type, too long legs, light hindquarters, especially, and too much weight in front, due to excessive length of head, prominent shoulders and a coarse coat are the exceptions taken to this breed. BREEDING STOCK SALES and show classifications both distinguish between market and breeding animals. The former are quite generally unsexed and command consideration only for what they themselves are. Breeding animals, on the other hand, have more than an intrinsic worth, they are the progenitors of future generations to whom are to be transmitted the characters of a numerous ancestry. Therefore, breeding animals should not be judged merely as individuals, but as representatives of an ancestry whose influence will dominate the succeeding generations of which they are the progenitors. 306. In the selection of breeding animals it must be borne in mind that they do not represent, in their physical make-up, all the characters which they have inherited, nor yet all the characters which they are capable of transmitting. Thus, the failure in the stud of some showring champions can be accounted for, likewise the superior value, as sires, of some individuals, themselves incapable of winning most humble honors in the show ring. 306. The successful sire or dam is the one which will produce, regularly, progeny of uniform excellence, true to type and possessing constitutional vigor sufficient to insure their living productive and reproductive lives (Figs. 146 and 147). velopment, by which we infer that an animal may be fully developed, as an individual, yet incapable of reproduction, the latter being over and above normal individual development. Therefore, stock animals should have size, FIG. 146. — Percheron yearlings whose sire i* shown as Figure 71 . They manifest uniform excellence transmitted by the superior sire of marked prepotency, as well as the characters desired in colts of this age. only is to be considered in show-ring judging. However, a superior ancestry may be evidenced by character and breediness, manifested in the head and neck especially. transmit characters which are incorporated in his make-up, there is greater likelihood of certain characters, good or bad, appearing or not appearing in the offspring, if they are or are not present in the parents. Therefore, the type and individuality desired in the progeny should be well marked in the parents. It is one thing to possess merit, quite another to transmit it. The force with which the characters of one or the other of the parents are impressed upon their offspring constitutes prepotency, and prepotency, as well as virility, is indicated by strong sex character — masculinity in the male and femininity in the female. is especially well developed, the heavy-crested neck, the strong-featured countenance, the bold demeanor, and even the voice all betokening the sire. It has been amply demonstrated, in practice, that the male which is wanting in these features, whose head and neck are not markedly different from those of the female, is no stock getter at all, potency is concerned. 309. Femininity (Fig. 150) is naturally characterized in the opposite manner. It implies, primarily, a total absence of any masculine character. Hence, the forequarters of the female are light, fine and undeveloped ; the hindquarters, on the contrary, are broad, the head is proportionately smaller, the expression of the countenance sweeter, and the manner more demure. " Staggy " females are not regular nor satisfactory breeders, as a rule, and an extreme manifestation of masculine character in the female may be associated with hermaphrodism. 310. Form in breeding animals. — There are special features of form in addition to the sex characters which may distinguish the male from the female (Fig. 151). It is generally conceded that the male animal should be larger than the female, although there are many instances in nature to contradict this theory. The form of the male is more compact, the female, since she is to be host to the developing f O3tus as well as contributing her share of the hereditary material, being more roomy and capacious of middle, longer in back, more open in the flank, and broader across the hips and buttock, the latter features insuring safe and comparatively easy delivery of the young. 311. Constitution in breeding animals. — Constitution is the last word in either production or reproduction. It limits the extent to which inherent possibilities may be realized. No matter how much speed or power, milkiness or beefiness, horses or cattle are endowed with, they cannot perform or produce to the full capacity of their endowment unless they have the stamina and constitutional vigor upon which to base such performance or pro- duct ion. It is essential that there should be transmitted, in addition to the characters desired, all the constitutional vigor that will be required to insure maximum attainment along the line of that character. Nothing will impair production nor prohibit reproduction of successive generations and the perpetuation of the stock without deterioration more than weak constitution. Hence, all other strong constitution. 312. Substance in breeding animals. — Substance is more essential than quality in most breeding animals, especially the males. It is a serious fault for any stud animal to be undersized, or too fine in bone. Ruggedness in males is more desirable than extreme finish. x With these exceptions, the judging of breeding classes is conducted along the same general lines as described for the market and breed types. The beef bull should be the masculine personification of the butcher steer, while the dairy bull (Fig. 152) should conform, as closely as it is possible for a male to do, to the milky form of the dairy cow. Most judges even attach importance to the size and placing of the rudimentary teats of the dairy bull. What is analogous to the crest of the stallion and bull is designated the scrag in the ram and the shield in the boar. STRESS has already been laid on the fact that the selection of breeding stock is a more important phase of the judging of animals than that which is done in the show ring. The great, even though lesser, importance of the latter should not be underestimated, however. The show ring has been a most influential agency in promoting the live-stock interests and in improving the class of stock bred. 313. The benefits of the stock show concern two classes of people, those who show and those who go. To the former, it constitutes the best advertising medium available. There is no better means of getting one's stock before those people to whom it is of greatest interest. It furnishes, to the exhibitors, also, an excellent opportunity to indulge in a most wholesome competition, and finally, although of least importance after a full accounting is taken, it may be a source of revenue in cash prizes. Those who go to the shows in the capacity of spectators only, derive merely entertainment in return for their admission fee, but there are usually in attendance at the shows a great many stock men whose singleness of purpose is to learn of live stock. To these the show is a great exposition of market and breed types; of most approved systems of breeding and methods of feeding. It affords inspiration to the ambitious stock man, then demonstrates the best means of attaining success. This educational feature is being appreciated more and more and is given greater prominence at the leading shows each year. In general the show stimulates interest in live stock. sions of all show classes : Market and Breeding. Classification within the market division is made on the basis of type, and all entries of a type may be further classified as to age, weight, height or sex. Breeding classes are provided for each of the recognized breeds, each breed group being subclassified as to sex and finally on the basis of age for each of the sexes. There are usually offered, in addition, special classes for get of sire, produce of dam, groups, herds and pens, both owned or bred by the exhibitor. Then there are championships decided among the first, and usually the second, prize winners in class, and finally a grand championship for the winner among champions. 316. Market division, Horses. — The bases upon which market horses are classified and shown have been given in connection with the market classes of horses — such a variety of classes within specified weights, heights and "Performance only to count" or "Performance 60%, conformation, quality, and manners 40%," as to make a detailed list unnecessary here (Figs. 153 and 154). Stallion foal. Brood mare, four years old or over.1 Brood mare, three and under four. Brood mare, two and under three. Brood mare, one and under two. Bull, two and under three. Senior yearling bull, calved between September 1 and January 1 of the year pfeceding the year of the show. Junior yearling bull, calved between January 1 and Aged herd consists of one bull, two or over, one cow or heifer, two and under three, one heifer, one and under two, and one heifer under one year (Fig. 158). Boar, two years old or over. Boar, eighteen months and under twenty-four. Boar, twelve months and under eighteen. Boar, six months and under twelve. Boar, under six months. Sow, eighteen months and under twenty-four. Sow, twelve months and under eighteen. Sow, six months and under twelve. Sow, under six months. 322. Age basis. — All ages are reckoned from January first except in the senior yearling and calf classes. Their ages date from September first, preceding. specific class requirements. Exception is made in the case of drafters, which, in addition to being shown in single, pair, three, four and six horse hitches, are also shown to halter. shown " in hand" (Fig. 159), either to halter or lead bridle in the case of draft and saddle horses, beside or in front of a saddle pony if trotters or pacers, and usually on a long lounge rein in the hand of a foot runner in the instance of Hackneys and Coach horses. It is preferable that horses so shown should not be prompted, but the Clydesdale show men are about the only ones to evince any regard for this preference. Prompting is frequently grossly overdone in the showing of draft horses and Hackneys, the voice, whip and all sorts of noisy contrivances being resorted to. Horses are led from the near side except when shown on the long rein, as Hackneys are. Then the horse is run up to the rail of the ring with the runner on his left, reversed and brought back with the rein over his back and the runner on his right and a little behind him. Harness and saddle horses are driven or ridden well into the corners of the show ring, in order to make as much of the straight-away as possible, and are usually called upon to work both ways of the ring for the purpose of obviating any deviation in the stride which may be due to taking the turns ; also to enable the judge to see both horses of a pair, or the saddle horse cantering on both leads. The special requirements of the service under which the horse is classed should be borne in mind by the judge. Work and station wagon horses should be handy in backing up to a platform, real or imaginary ; runabout horses should stand without hitching ; and saddle horses should stand to be mounted. Drafters and saddle horses are shown at the walk, as well as at the trot, and the other saddle gaits in the case of the latter, while harness horses are rarely, if ever, walked. Entries in roadster classes are expected to show as much speed as is possible in a small ring, while high steppers show at a park gait of eight to twelve miles, unless " pace and action " are specified. All horses are required to stand in pose either squarely on their feet or camped. Performance alone may count, or, in addition, conformation, quality, manners and appointments, proportionately, as specified in the catalogue. 324. " Vetting." — Veterinary examination may be required before the horses are shown, a report of which is to be furnished to the judge when the class is called, or they may be shown subject to disqualification, in case they manifest unsoundness in the ring. Unsoundness detected or suspected in the show ring by the judge is usually referred to the official veterinarian, whose rulings are final. Also, measurements and determination of age, as in the breeding classes, are settled by the veterinarian and the entries qualified or disqualified upon this basis. sideration of them. 326. Beef cattle, in the steer and cow classes, are shown in halters, unless a particularly unruly one requires a ring in his nose, while bulls are regularly led by a ring in which a strap is snapped. The coats of beef cattle receive special preparation. Both sexes of those breeds which have a sufficiently long and heavy coat, as the Short-horn, Hereford and Galloway, together with their pure bred and grade steers, are shown rough, i.e. with the hair washed out and then brushed or combed the wrong way or arranged in some fantastic design. Showing rough enables a clever show man to overcome the appearance of many defects, roughing the coat especially where there may be a slack spot, as in the crops, while smoothing it down upon or roughing round about any undue coarseness or prominence. Angus breeding cattle, as a rule, are shown smooth while their grade steers are usually shown rough if they have enough hair. Some beef cattle, especially the smoother coated ones, are trimmed about the ears and poll, while the horns are generally rubbed and polished to a fine finish. Their coats are thoroughly groomed, usually blanketed, their switches washed and picked out, egg shampoos and everything possible being resorted to that might enhance the handling quality of the hide and hair. Cattle are taught to stand squarely on their feet, a careless position often giving the appearance of a low back or some other physical defect, while a special pose may improve the appearance of certain lines very materially. Also, carrying the head to one side or the other may alter the handling. They are taught to lead promptly so as to make the best appearance when asked to move about. about as fat as they can be made without being overdone. 326. Dairy cattle. — Cows are shown in halters, while bulls are led with rings in their noses and almost invariably by means of staffs. The coats of dairy cattle of both sexes are shown as sleek as they can be made without removing the secretions. Their heads, ears and tails are clipped, horns polished and switches carefully hair dressed. The too common practice of " stretching " udders by deferred milking is a practice not to be countenanced. Dairy cattle are taught to pose in that position which shows their lines and features to best advantage. order to enable them to stand well. Too long a toe, for instance, will throw an animal down on his dew claws, putting every joint on a tension and the leg in an unnatural position. 327. Sheep are led by placing the left hand under or partly around the neck, with the right tickling the tail just enough to induce them to step forward, standing, of course, on the left side, the same as in handling any other animal. They are held by one hand under the jaw, the other free to be passed to the back of the head or to the dock, in case it becomes necessary to steady the sheep, or to assist, in any other way, keeping him in pose. Trimming is the universal practice among shepherds and is defended on the ground that there is no deception practiced, since none but a most incompetent judge would be influenced by the appearance of the clipped fleece, while it does have the advantage of greatly improving the looks of the sheep while on exhibition. It has been suggested by one of our leading authorities l that it is as becoming for sheep to be trimmed as for " Men and women to wear their best clothes when going to a party." Some shepherds display great cleverness in the trimming of their sheep, overcoming the appearance of a low back or a light hindquarter, for instance, in a most ingenious way. The fleece is washed before trimming, then dried out to render it fluffy and bright. Cotted portions may be combed out after having been softened with olive oil. After the fleece of the sheep has been carefully prepared for the show ring by washing and trimming it is usually protected by a duck blanket, hood and all, in the case of those breeds which are wooled on the face. 1 Kleinheinz, " Sheep Management." Coloring the fleece, while common, is not so generally practiced as trimming, and for less satisfactory reasons. Ochre is used, and the color is usually yellow, although red and even brown are sometimes employed. If the skin and fleece of the sheep are in proper condition, their appearance is not improved by the addition of any coloring. Much time is spent by shepherds in training their sheep to stand well while being shown, not only to remain quiet and permit of handling by the judge but so as to display their good points to greatest advantage. In order to stand well their feet must be trimmed and their pasterns strong to keep them up on their toes. 328. Swine. — Since hogs are not taken in hand, but merely kept within bounds by means of hurdles or paddles, the manner of showing is practiced by the hog himself, rather than by the man who has him on exhibition. A hog with style will show himself and such a one, of the right sort, well fitted, has had about all done for him that can be done when he enters the ring. It is customary to wash them thoroughly and brush them smooth, oil, and even lamp black, in the case of black hogs, being added to enhance their sleek appearance. 1 A novel feature of this table is that it is truly a table of " world's " records. When a foreign record excells an American record, notice is made of the fact. The lines in black-faced type are the new world's records made in 1913. A star * indicates a performance against time. A double star ** indicates a performance against time behind a wind shield. — Compiled by The Horseman, Chicago 111. Fastest Pacing Races Two-heat race — Prince Alert, b. g., 9, by Crown Prince (1901) 2 : 02}, 2 : 00 J Two-heat race by stallion — Earl J., gr. h., by The Earl (1913) 2 : 02 f, 2 : 02 J Two-heat race by a mare — Evelyn Wr., b. m., by The Spy (1912) 2 : 03}, 2 : 00* Three-heat race, divided heats — Gratt, blk. h., 9, by Grattan (1906) APPENDIX 331 Nine-heat race — Dombey, Jr., br. h., by Dombey (1899) (Belle Colley won first and sixth, Marion G. second and fifth, Maxine fourth and seventh heats) 2: 09}, 2: 10, 2: 11}, 2: Hi, 2: 13}, 2: 15,2: 12}, 2:15, 2 : 22\ Twelve-heat race — Dandy O., b. h., 3, by Dall Brino (1891) (to high wheels) (Birchwood won first and second, Jessie L. third and fourth, Maud M. fifth and sixth, Rahletta seventh, lalene eighth, Fred K. Lass 66th of Hood Farm 271896 Corinne of Roycroft 247303 . . . Lass 54th of Hood Farm 257375 . . Tonona Pogis' Fontaine 280417 . . Name and H. R. Number of Cow Mary Golden Letta 240917 . . . Great Edison's Polly 243658 . . . Lass 38th of Hood Farm 223628 . . Lass 51st of Hood Farm 247084 . . Pedro's Foxy Mabel 241911 . . . LB. Oz. LB. Oz. LB. Oz. 12345 8. 816 1.27 960 1 14513 2. 720 8. 847 10 11115 11. 640 15.3 754 1 14160 5. 628 1.5 738 15 10755 ... 609 12.8 717 6 Half Years and Under Three Years Milk Butter Fat 85 ' , Butter LB. Oz. LB. Oz. LB. Oz. 9295 5. 557 7.8 655 14 8995 6.4 548 3.6 644 15 9334 3. 544 14.8 641 1 8968 10. 539 5.1 634 8 8209 3.2 530 4.2 623 13 May Rilma 22761, Reentry, 1726 Sire Mars of Woodcrest (9290) A. R. Sire Mr. Dooley of Mapleton (6834) Dam Charity of Mapleton (13769) Dam Princess Bonnie of Paxtang (8777. Breeder — A. J. Cassatt, Berwyn, Penn. Owner — E. B. Cassatt, Berwyn, Penn. Born — Dec. 15, 1906. Calved — April 4, 1913. Requirement for admission : 360.00 Ib. butter fat. Official year's record : 19673.00 Ib. milk ; 1073.41 Ib. butter Feed Record MAY, 1913. 10 Ib. grain daily of the following mixture : 250 Ib. bran, 50 Ib. each hominy, cottonseed meal and oil meal, 100 Ib. gluten ; 3 Ib. beet pulp, 2 Ib. molasses, hay, with pasture. JUNE, 1913. 18 Ib. grain daily of the following mixture : 250 Ib. bran, 50 Ib. each hominy, ground oats, cottonseed meal and oil meal ; 3 Ib. beet pulp, 2 Ib. molasses, green feed. JULY, 1913. 18 Ib. grain daily of the following mixture on 1st, and from llth to 31st, 15 Ib. daily from 2d to llth : 250 Ib. bran, 50 Ib. each hominy, cottonseed meal, ground oats and oil meal, 100 Ib. gluten ; 3 Ib. each molasses and beet pulp, corn fodder from 1st to 15th, clover from 17th to 31st. beet pulp and molasses, carrots, ensilage and clover hay. MAR., 1914. Same ration as given in February. APRIL, 1914. Same ration as given in February; no ensilage Reentry Lady Lesbia 25142, A. R. 1348, Reentry Glenanaar of the Glen 23619, A. R. 1907 Imp. Dinah II of the Fountain 28482, ANNUAL MEETING, APRIL, 1910 The Saddle horse must be sound, of good conformation, substance, finish, style, and shown without artificial appliances, and up to carrying at least one hundred and sixty (160) pounds. The three-gaited horse should go plain walk, briskly and with speed equal to four (4) miles an hour ; canter reasonably high and gentle ; trot, steady, straight and true ; action enough to be attractive; well balanced and with speed equal to twelve (12) miles an hour. Added to the foregoing the five-gaited horse should go running walk, fox trot or slow pace, smoothly and equal to six (6) miles an hour; rack easily without being forced, with speed equal to twelve (12) miles an hour. Must stand quietly, back readily and lead with either foot in a canter from a halt. High rate of speed and racing is forbidden. High School Gaits are not Saddle Gaits. It is understood that an animal which has been educated in high school may inadvertently show a step or two in this school when changing suit. Such evidence is not to disqualify a horse, though it is objectionable, but any intentional exhibition of high school is prohibited and shall disqualify an entry. appearance, perfect respiration, brightness of eye ... 10 Size. — Ponies over four years old 42 inches and under in height, two points to be deducted for every inch over 42 inches up to 46 inches, fractional portions to count as full inches 25 and tapering toward the nose, muzzle fine ; nostrils wide and open ; distance from eyes to nostrils of moderate length ; eyes mild, full and expressive, indicative of good disposition ; ears of good medium size, well set and well covered with hair; poll well denned, and without any appearance of horns or scurs ; jaws clean ... 10 the blades and top; with vertebra or backbone slightly above the scapula or shoulder blades, which should be moderately broad 6 loins strong ; hook bones moderate in width, not prominent, and well covered ; rumps long, full, level and rounded neatly into hindquarters . . 10 10. Hindquarters. — Deep and full ; thighs thick and •muscular, and in proportion to hindquarters; twist filled out well in its "seam," so as to form an even, wide plain between the thighs 8 abundantly covered with thick, soft hair (much of the thriftiness, feeling properties and value of the animal depends on this quality, which is of great weight in the grazier's and butcher's judgment. A good "touch " will compensate for some deficiencies of form. Nothing can compensate for a skin hard and stiff. In raising the skin from the body it should have a substantial, soft, flexible feeling, and when beneath the outspread hand it should move easily as though resting on a soft, cellular substance, which, however, becomes firmer as the animal ripens. A thin, papery skin is objectionable, especially in cold climate) . . 10 Forehead broad and prominent, face short, slightly tapering towards nose ; muzzle full ; nostrils wide and open ; eyes large and expressive ; ears of medium size, well set and well covered with hair; horns of medium size, even color, coming from head at right angles, set on level with crops, back and tail head, curving forward and downward. Throat, 2 points — Vigorous, compact and symmetrical. Bulls masculine and possessing an abundance of quality and predominant breeding characteristics. Females matronly, roomy, smooth, showing quality and feminine appearance throughout. Weight, 5 points — wards with fringe of long hairs. Neck — Moderate in length, clean and filling well into the shoulders ; the top in a line with the back in a female, and in a male naturally rising with age. Legs — Short and clean, with fine bone. Tail — Well set on, and moderately thick. Skin — Mellow and moderately thick. hair is very objectionable. The last point is a very important one. Some animals are without this thick mossy covering, which should, in the very best hides, have a feeling akin to a sealskin jacket. The great advantage of such a covering is obvious. In cold or windy weather it has warmth and on wet days will throw off a great amount of rain. For the making of fine robes it is a necessity ; coarse hair will not wear nearly so well. The defects specially to be guarded against as objectionable are the following : 20. Rough, angular form. These defects should be avoided by the careful breeder. It is hard to get a herd without some of these faults, but a knowledge of what should be shunned will assist in bringing a herd up to a good standard of excellence. curving 3 . . . . B — Eyes full and placid ; ears medium size, fine, carried alert ; muzzle broad, with wide-open nostrils and muscular lips ; A — Shoulders light, good distance through from point to point, but thin at withers ; chest deep and full between and just back of forelegs 5 . . . . B — Ribs amply sprung and wide apart, giving wedge shape, with deep, large abdomen, firmly held up, with strong, muscular development 10 . . . . room for udder 3 . . G — Legs proportionate to size and of fine quality, well apart, with good feet, and not to weave or cross in walking .... 2 . . A symmetrical balancing of all the parts, and a proportion of parts to each other, depending on size of animal, with the general appearance of a high-class animal, with capacity for food size and incurving 5 .... B — Muzzle broad, nostrils open, eyes full and bold ; entire expression one of vigor, resolution and masculinity .... 5 .... A — Shoulders full and strong, good distance through from point to point, with welldefined withers ; chest deep and full between and just back of forelegs . . 15 . . . . B — Barrel long, of good depth and breadth, high arched flank 3 . . . . G — Legs proportionate to size and of fine quality, well apart, with good feet, and not to weave or cross in walking . . . 5 . . . . Thoroughly masculine in character, with a harmonious blending of the parts to each other ; thoroughly robust, and such an animal as in a herd of wild cattle would likely become master of the herd by the law of natural selection and survival of the fittest . . . . . . . , . 15 . . . . COUNTS Long, thin neck with strong juncture to head ; clean throat. Backbone rising well between shoulder blades ; large rugged spinal processes, indicating good development of the spinal cord 5 Pelvis arching and wide ; rump long ; wide, strong structure of spine at setting on of tail. Long, thin tail with good switch. Thin incurving thighs 5 Ribs amply and fully sprung and wide apart, giving an open, relaxed conformation ; thin arching flanks . 5 Abdomen large and deep, with strong muscular and navel development, indicative of capacity and vitality 15 Hide firm yet loose, with an oily feeling and texture, but not thick . 3 Milking Marks Escutcheon wide on thighs ; high and denoting broad, with thigh ovals .... 2 long and broad Long masculine neck with strong juncture to head; clean throat. Backbone rising well between shoulder blades ; large rugged spinal processes, indicating good development of the spinal cord Pelvis arching and wide ; rump long ; wide, strong structure of spine at setting of tail. Long, thin tail with good switch. Thin incurving thighs Ribs amply and fully sprung and wide apart, giving an open relaxed conformation ; thin, arching flank . Abdomen large and deep, with strong muscular and navel development, indicative of capacity and vitality Hide firm yet loose, with an oily feeling and texture, but not thick . Dairy As shown by having a great deal of Symmetry Color of hair, a shade of fawn with and Size, white markings. Cream-colored 22 nose. Horns amber-colored, curving and not coarse Weight . . The interlines in smaller type relate entirely to the method of application agreed on by the Inspectors, in order to secure uniformity of work. The a e as follows : vs, very slight ; s, slight ; m, marked ; vm, very marked ; Of medium length ; clean and trim, especially under the eyes ; showing facial veins ; the bridge of the nose straight Discredit, m i, e J. Long ; fine and clean at juncture with the head ; free from dewlap ; evenly and smoothly joined to shoulders Of moderate depth and lowness ; smooth and moderately full in the brisket ; full in the foreflanks (or through at the heart) . . . . Long ; of wedge shape ; well rounded ; with a large abdomen, trimly held up. (In judging the last item age must be considered.) Broad ; level or nearly level between the hook bones ; level and strong laterally; spreading from chine broadly and nearly level ; hook bones fairly prominent .... pelvis ; nearly level laterally ; comparatively full above the thurl ; carried out straight to dropping of Discredit, vs i, s J, m 1, vm 1J, e 2. Deep; straight behind; twist filled with development of udder ; wide and moderately full at the sides Comparatively short ; clean and nearly straight ; wide apart ; firmly and squarely set under the body; feet of medium size, round, solid and deep Hair and Hair healthful in appearance ; fine, Handling soft, and furry ; the skin of medium thickness and loose ; mellow under the hand ; the secretions oily, abundant, and of a rich brown or yellow color Mammary Very large ; very crooked (age must Veins be taken into consideration in judging of size and crookedness) ; entering very large or numerous orifices ; double extension ; with special developments, such as branches, connections, etc quarters even; nearly filling the space in the rear below the twist ; extending well forward in the front ; broad and well held up .... to exceed eight points .... Discredit, vs 1, s 2, m 3, vm 5, e 8. "General \ For deficiency Inspectors shall disSymmetry \ credit from the total received not and Fine- to exceed eight points .... ""Credits for Excess of Requirement in Production. A cow shall be credited one point in excess of what she is otherwise entitled to, for each and every eight per cent that her milk or butter recorcl exceeds the minimum requirement .... In scaling for the Advanced Register, defects caused solely by age, or by accident, or by disease not hereditary, shall not be considered. But in scaling for the show ring, such defects shall be considered and duly discredited A cow that in the judgment of the Inspector will not reach at full age, in milking condition and ordinary flesh, 1000 lb., live weight, shall be disqualified for entry in the Advanced Register No cow shall be received to the Advanced Register that, with all credits due her, will not scale, in the judgment of the Inspector, at least 75 points. (See in last paragraph of Rule VI an exception to these requirements.) Dropped Weight The interlines in smaller type relate entirely to the method of application agreed upon by the Inspectors, in order to secure uniformity of work. The abbreviations are as follows : va, very slight ; s, slight ; m, marked ; vm, very marked ; e, extreme. oval ; inclining forward ; moderately curved inward ; of fine texture ; in appearance waxy . . . Long ; finely crested (if the animal is mature) ; fine and clean at juncture with the head ; nearly free from dewlap; strongly and smoothly joined to shoulders . Discredit, vs J, s 1, m J, vm f, e 1. Of medium height ; of medium thickness, and smoothly rounded at tops ; broad and full at sides ; smooth over front ...:.... Broad ; level or nearly level between hook bones ; level and strong laterally ; spreading out from the chine broadly and nearly level ; the hook bones fairly prominent . . . .% Discredit, vs J, s J, m i, vm }, e 1. Long ; broad ; high ; nearly level laterally ; comparatively full above the thurl ; carried out straight to dropping of tail . . v . . . Comparatively short ; clean and nearly straight ; wide apart ; firmly and squarely set under the body; arms wide, strong and tapering; feet of medium size, round, solid and deep Offspring Large at base, the setting well back ; tapering finely to switch ; the end of bone reaching to hocks or below ; the switch full Hair healthful in appearance; fine, soft, and furry; skin of medium thickness and loose ; mellow under the hand ; the secretions oily, abundant, and of a rich brown or A bull shall be credited one point in excess of what he is otherwise entitled to, for each and every animal of which he is sire actually entered in the Advanced Register, not to exceed ten in number .... In scaling for the Advanced Register, defects caused solely by age, or by accident, or by disease not hereditary, shall not be considered. But in scaling for the show-ring, such defects shall be considered and duly discredited A bull that in the judgment of the Inspector will not reach, at full age and in good flesh, 1800 lb., live weight, shall be disqualified for entry in the Advanced Register . No bull shall be received to the Advanced Register that, with all credits due him, will not scale, in the judgment of the Inspector, at least 80 points. (See amendment to Rule IV, an exception to these requirements.) Forehead — broad and clearly defined . . 1 Horns — wide set on and inclining upward . 1 Face — of medium length, slightly dished ; 36G APPENDIX Teats — evenly placed, distance apart from side to side equal to half the breadth of udder, from back to front equal to one third the length ; length 2£ to 3\| inches, thickness in keeping with length, hanging perpendicular and not tapering 8 thighs and extending well upward ... 2 Color — red of any shade, brown, or these with white ; mahogany and white, or white ; each color distinctly defined. [Brindle markings allowed but not desirable] . . 2 Jaws — wide at the base and strong ... 1 Eyes — moderately large, full and bright . 3 Ears — of medium size and fine, carried alert 1 Expression — full of vigor, resolute and masculine ... 3 seasons of the year gray ; white splashes near udder not objectionable, light stripe along back. White splashes on body or sides objectionable. Hair between horns usually lighter shade than body . . 4 The scale of points for males shall be the same as that given for females, except that No. .11 shall be omitted and the bull shall be credited 10 points for size and widespread placing of rudimentary teats, and 10 additional points for perfection of belt. Head, moderately long, with a broad indented forehead, tapering considerably towards the nostrils ; the nose of a flesh color, nostrils high and open, the jaws clean, the eye bright, lively and prominent, and surrounded by a flesh-colored ring, throat clean, ears thin, the expression gentle and intelligent ; horns matching ; spreading and gracefully turned up, of a waxy color, tipped with a darker shade . 8 with flanks fully developed 8 Back, straight and level from the withers to the setting on of the tail, loin broad and full, hips and rump of medium width, and on a level with the back 16 Size, minimum weight at 3 years old, 1000 pounds ... 2 General Appearance, as indicated by stylish and quick movement, form, constitution and vigor, and the under line as nearlv as possible parallel with the line of the back 8 Head, masculine, full and broad, tapering toward the nose, which should be flesh-colored ; nostrils high and open, muzzle broad, eyes full and placid and surrounded with flesh-colored ring, ears of medium size and thickness, horns medium size, growing at right angles from the head, or slightly elevated, waxy at the base, tipped with Back, straight and level from the withers to the setting on of the tail, loin broad and full, hips and rump of medium width and on a level with the back .... 20 admissible unless around the purse 8 Size, minimum weight at 3 years old 1400 pounds ... 4 General Appearance, as indicated by stylish and quick movement, form, constitution, and vigor, and the under line as nearly as possible parallel with the line of the back : 8 udder may be white, with some white running forward to the navel. Nose of a clear flesh color. Interior of ears should be of a yellowish, waxy color. 2 sloping gradually from above eyes to poll. The poll well denned and prominent, with a sharp dip behind it in center of head. Ears of medium size and well carried. Eyes prominent ; face well dished between the eyes. Muzzle wide, with large nostrils 6 from head to top of shoulder with inclination to arch when fattened, and may show folds of loose skin underneath when in milking form .... 3 level from withers to setting on of tail, moderately wide, with spring of ribs starting from the backbone, giving a rounding appearance, with ribs flat good size 4 Objections : Lack of development, especially in forward udder. Udder too deep, "bottle shaped " and teats too close together. Teats unevenly placed and either too large or too small. white, with some white running forward to the navel. Nose of a clear flesh color. Interior of ears should be of a yellowish, waxy color .... 2 Poll stronger and less prominent than in cow. Ears of medium size and well carried ; eyes prominent ; muzzle wide with large nostrils .... 12 level from withers to setting on of tail, moderately wide, with spring of ribs starting from the backbone, giving a rounding appearance, with ribs flat Position of rudimentaries 6 Objections : Rudimentaries placed back on scrotum, or placed too close together, indicating tendency to transmit badly formed udders. Head. — Medium in size and hornless, fine, carried well up, the forehead or face well covered with wool, especially between the ears and on the cheeks, and in the ewe slightly dished 5 General Appearance. — Spirited and attractive, with a determined look, a proud and firm step, indicating constitutional vigor and thorough breeding 8 3. Fleshing While the body should be well formed, with the full outline pleasing to the eye, yet it is the quality and quantity of flesh, not fat, which gives value to the carcass. Therefore the parts furnishing the high-priced cuts should be fully developed. The back, loins and legs should be so fleshed as to show a large percentage of flesh compared with the other parts of the body ; at the same time symmetry must prevail throughout. 4. Fleece and Skin Fleece of good length, elastic to the touch, medium fine and slightly crimped, free from black fiber and hairiness. Ram's scrotum to be well covered with wool. Objections Long narrow head with long ears and neck; long legs; black wool on head to any noticeable extent ; failure of wool to meet closely at the junction of face-wool and on cheeks ; white spots on face and legs ; crooked spine ; light flanks, with long, weak pasterns ; spotted skin ; narrow chest showing lack of constitution. Form. — Of good general appearance, made by a wellbalanced conformation, free from coarseness in any part and showing good style at rest and in motion 15 Color (head and legs). — Dark brown or black. Eyes. — Prominent and lustrous. Ears. — Moderately long and thin, and dark brown or black General Conformation and Quality. — Deep and full breast and large through chest. Back, wide and straight with wellsprung, deep ribs, legs well placed and leg of mutton full and thick. Body well fleshed, skin pink with no blue or dark coloring, fleece compact and medium fine, bone strong and fine, general appearance graceful, symmetrical, active — 20 points. Size. — In good flesh when fully matured a twenty months' old ram should weigh not less than 200 pounds, and a ewe not less than 130 pounds — 10 points. Head. — Should be free from horns or scurs of any length. It should be medium length and broad, with ample breadth between the eyes. Ears should be of medium length and usually erect when at repose. Head covered with clean white hairs, extending from nostrils to back of poll. Ridge of head from between eyes to nostrils straight or slightly arched in female and more strongly arched or Roman in rams. Color of tip of nose black. — 15 points. Body. — Well proportioned, having notable depth, with thickness on top and at flanks. Loins should be very broad and thick, shoulders should set well back and be smoothly covered, and crops be full and well arched. The rump should be long, broad and level. — 20 points. Legs. — Should be short, well set apart and be covered with clean white hair, with no wool below hocks and knees. The hind legs should be flat and deep below hocks. Pasterns should be strong and not show weakness, supporting the body well. — 10 points. Fleece. — Should cover the body completely to behind the poll and ears and down to knees and hocks. Under part of the body should be well covered. In mature animals should be not less than three inches long for annual growth and be compact and of medium wool class. Rams should shear at least 12 pounds and ewes 8 when in mature form, to be desirable representatives of the breed. — 20 points. Sours on the head, flesh-colored skin about the nostrils, hair about the thighs or kemp on the body, reddish or sandy hair on head or legs, lack of wool on under part of body. back and broad at the base where it leaves the chest, gradually tapering toward the head, being fine where head and neck join ; neck straight from chest, showing a straight line from rump to poll . 6 OF POINTS For Cotswold Ram — Head not too fine, moderately small and broad between the eyes and nostrils, but without a short, thick appearance, and in young animals well covered on the crown with long, lustrous wool ... 8 short hair 4 Collar. — Full from breast and shoulders, tapering gradually all the way to where the neck and head join. The neck should be short, thick and strong, indicating constitutional vigor, and free from coarse and loose skin . 6 Shoulders. — Broad and full, and at the same time join so gradually to the collar forward and chine backward as not to leave the least hollow in either place ... 8 Forelegs. — The mutton on the arm or forethigh should come quite to the knee. Leg upright with heavy bone, being clear from superfluous skin, with wool to fetlock, and may be mixed with gray 4 For Cotswold Ewe. — Head moderately fine, broad between the eyes and nostrils, but without a short, thick appearance, and well covered on crown with Jong, lustrous 8 wool x Collar. — Full from breast and shoulders, tapering gradually all the way to where the neck and head join ; the neck should be fine and graceful, and free from coarse and loose skin 5 Shoulders. — Broad and full, and at the same time join so gradually to the collar forward and chine backward as not to leave the least hollow in either place .... 8 Forelegs. — The mutton on the arm or forethigh should come quite to the knee ; leg upright with heavy bone, being clear from superfluous skin, with wool to fetlock, Chest. — Deep, full and wide, with good heart girth ... 6 Shoulder. — Smooth and even on top and in line with side . 6 Side. — Deep, smooth, well let down ; straight side and great weight 10 Size. — Size all that is possible without loss of quality or symmetry, with good length. Weight in good condition : boars at 12 months, 350 to 450 Ib. ; at 24 months, 500 to 700 Ib. ; sows at 12 months, 350 to 400 Ib. ; at 24 months, 500 to 700 Ib 6 Head should be broad, even and smooth between and above the eyes. Slightly dished, tapering evenly and gradually to near the end of the nose. Broad lower jaw, head inclined to shortness but not enough to give appearance of stubby nose. And in male a masculine appearance and expression. Objections : Head long, narrow between the eyes ; nose uneven and coarse ; too large at the muzzle or the head too short ; not full or high above the eyes ; or too much wrinkled around or above the eyes. Eyes. — 2. Ears attached to the head by a short, firm knuckle, giving free and easy action. Standing up slightly at the base to within two thirds of the tip, where a gentle break or drop should occur ; in size neither too large nor too small, but even, fine, thin, leaf shape ; slightly inclined outward. Objections: Large, floppy, straight, upright or coarse; knuckle long, letting the ear drop too close to the head and face, hindering of free use of the ears. Neck. — 2. Full, broad, deep, smooth and firm, carrying fullness back near to point of shoulders, and below line of lower jaw so that lower line will be as^ low as breast bone when head is carried up level. Objections : Light, flabby, thin and wedge shaped, deeply wrinkled, not drooping below line of lower jaw, and not carrying fullness back to shoulder and brisket. Shoulder. — - 6. Broad and oval at top, showing evenness with the back and neck, with good width from the top to the bottom, and even smoothness extending well forward. Objections : Narrow at top or bottom ; not as deep as the body, uneven width. Shields on pigs under eight months of age, or showing too much shield at any age. Chest. — 12. Large, wide, deep and full ; even under line to the shoulder and sides with no creases ; giving plenty of room for the heart and other organs, making a large girth indicating much vitality. Brisket smooth, even and broad; wide between the legs and extending well forward, showing in front. Objections : Pinched appearance at the top or bottom, or tucked in back of the forelegs ; showing too narrow between the legs ; not depth enough back of the shoulder. Brisket uneven, narrow, not prominent. Broad, straight or slightly arched, carrying same width from shoulder to ham, surface even, smooth, free from lumps, creases, or projections ; not too long but broad on top, indicating well-sprung ribs; should not be higher at hip than at shoulder and should fill out at junction with side, so that a straightedge placed along at top of side will touch all the way from point of shoulder to point of ham. Should be shorter than lower belly line. Objections : Narrow, creased back of shoulders, swayed or hollow, dropping below a straight line ; humped or wrinkled ; too long or sunfish shaped ; loin high, narrow, depressed or humped up ; surface lumpy, creased, ridgy or uneven ; width at side not as much as shoulder and ham. Sides full, firm and deep, free from wrinkles; carrying size down to belly ; even from ham to shoulder ; ribs of good length, well sprung at top and bottom. Objections : Flat, thin, flabby, pinched, not as full at bottom as at top ; drawn in at shoulder so as to produce a crease, or pinched and tucked up and in as it approaches the ham ; uneven surface ; ribs flat or too short. Belly broad, straight and full, indicating capacity and room, being about the same or on a level at the flank with the under line of the chest. Under line straight, or nearly so, and free from flabby appearance. Hams broad, full, deep and long from rump to hock. Fully developed above and below, being wide at the point of the hip, carrying width well down to the lower part of the hams. Fleshy, plump, rounding fullness perceptible everywhere. Rump rounding and gradually sloping from the loin to the root of the tail. Broad and well developed all along from loin and gradually rounding to the buttock; lower front part of ham should be full and stifle well covered with flesh. Even width of ham and rump with the back, loin, and body. Even a greater width as to females not objectionable. Objections : Ham short, narrow, too round or slim. Not filled out above or below, or unshapely for deep meat; not as wide as the body ; back or loin too tapering or small. Rump narrow or pointed, not plump or well filled or too steep from loin to the tail. Legs medium length, straight, heavy bone, set well apart and squarely under body, tapering, well muscled and wide above knee and hock; below hock and knee round and tapering, capable of sustaining weight of animal in full flesh without breaking down; bone firm and of fine texture; pasterns short and nearly upright. Feet firm, short, tough and free from defects. Objections : Legs long, slim, coarse, crooked ; muscles small above hock and knee ; as large at foot as above knee ; pasterns long, slim, crooked or weak ; the hocks turned in or out of straight line ; legs too close together ; hoofs long, slim and weak; toes spreading out or crooked or unable to bear up weight of animal without breaking down. Tail. — 1. Objections : Bristles, hair coarse, harsh, thin, wavy or curly ; swirls ; standing up ; ends of hair split and brown, not evenly distributed over all of the body, except the belly. Clipped coats should be cut 1.5 points. Color. — 2. Black with six (6) white points ; tip of tail, four white feet and white in face, or on the nose or on the point of the lower jaw. All to be perceptible without close examination. Splashes of white on the jaw, legs, or flank or a few spots of white on the body not objectionable. Large for age. Condition, vigor and vitality to be considered. There should be a difference between breeding animals and those kept or fitted for the show of at least 25 per cent in size. In show condition Or when fat, weights for the different ages should be about as follows : Boars over two years old, seven hundred (700) pounds. Sows over two years old, six hundred (600) pounds. Boars eighteen months old, six hundred (600) pounds. Sows eighteen months old, five hundred (500) pounds. Boars one year old, four hundred and fifty (450) pounds. Sows one year old, four hundred and fifty (450) pounds. Boars and sows six months old, one hundred and eighty (180) pounds. All hogs in just fair breeding condition, one fourth less for size. The keeping and chance that a young boar has cuts quite a figure in his size and should be considered, other points being equal. Fine quality and size, combined, are desirable. Objections : Overgrown, coarse, flabby, loose appearance, gangling, hard to fatten ; too fine, undersize ; short, stubby, inclined to chubby fatness. Not a hardy, robust animal. Action and style. — 3. Action vigorous, easy and graceful. Style attractive; high carriage ; and in males testicles should be prominent and of about the same size, and yet not too large or pouchy. Healthy, skin clear of scurf, scales and sores ; soft and mellow to the touch ; flesh fine ; evenly laid on and free from lumps and wrinkles. Hair soft and lying close to the body ; good feeding qualities. Objections: Unhealthy, skin scaly, wrinkled, scabby or harsh, flabbiness or lumpy flesh ; too much fat for breeding. Hair harsh, dry and standing up from the body ; poor feeders ; deafness, partial or total. Disposition. — 2. Detailed Description Head and face. — Head short and wide ; cheeks neat ; jaws broad and strong ; forehead medium, high and wide ; face short and smooth ; nose neat, tapering and slightly dished. Objections : Head long, narrow or coarse ; cheeks too full ; forehead low and narrow ; jaws contracted and weak ; face long, narrow and straight; nose coarse, clumsy or dished like a Berkshire. side and carrying size down to line of belly. Objections : Deficient in width or depth ; extending above line of back ; thick beyond line of sides and hams ; shields on boars too coarse and prominent. Chest — Heart girth. — Large, wide, deep and full ; even under line to the shoulder and sides with no creases ; giving plenty of room for the heart and other organs, making a large girth indicating much vitality. Brisket smooth, even and broad ; wide between the legs and extending well forward showing in front. Objections : Pinched appearance at the top or bottom, or tucked in back of forelegs ; showing too narrow between the legs, not depth enough back of the shoulder. Brisket uneven, narrow, not prominent. at shoulder as at ham. Objections : Narrow ; swayed ; humped ; creasing back of shoulders ; sunfish shaped ; uneven width ; lumps or rolls. Sides. — Full ; smooth ; deep ; carrying size down to line of belly ; even with line of ham and shoulder. Objections : Flat ; thin ; flabby ; uneven surface ; compressed at bottom ; shrunken at shoulder and ham. Ribs. — Long ; well sprung at top and bottom ; giving animal a square form. girth or length of body from top of head to root of tail. Ham or rump. — Broad ; full ; long ; wide and deep ; admitting of no swells ; buttock full, neat and clean ; stifle well covered with flesh, nicely tapering toward the hock ; rump slightly rounding from loin to root of tail, same width as back, making an even line with sides. Objections : Narrow ; short ; not filled out to stifle ; too much cut up in crotch or twist ; not coming down to hock ; buttocks flabby ; rump flat, narrow, too long, too sharp or peaked at root of tail. Legs. — Medium length ; strong and straight ; set well apart and well under body ; bone of good size ; firm ; well muscled ; wide above knee and hock, round and tapering below knee and hock, enabling the animal to carry its weight with ease ; pasterns short and nearly upright. Objections : Too short or too long ; weak ; crooked ; too close together ; muscles weak ; bone too large and coarse, without taper ; pasterns long, crooked or slim. up, not evenly distributed over all the body except the belly. Color. — White. Red or black spots in hair disqualify, but blue spots in hide (commonly known as freckles), while objectionable and to be discouraged, do not argue impurity of blood. Objections : Color any other than white. Size. — Large for age and condition. Boar two years and over, if in good flesh, should weigh not less than 500 pounds; sow same age and condition, not less than 450 pounds. Boars eighteen months old, in good flesh, should weigh not less than 400 pounds; sows, 350. Boars twelve months old, not less than 350 pounds ; sows, 300. Boars and sows six months old not less than 150 pounds each, and other ages in proportion. Action. — Easy and graceful ; high carriage ; active ; gentle and easily handled. In males, testicles should be readily seen, and of same size and carriage. Head and face. — Head short and wide ; cheeks neat ; jaws broad and strong ; forehead medium, high and wide ; face short and smooth ; nose neat, tapering and slightly dished. Objections : Head long, narrow, or coarse ; cheeks too full ; forehead low and narrow ; jaws contracted and weak ; face long, narrow and straight ; nose coarse, clumsy or dished like a Berkshire. Objections : Deficient in width or depth ; extending above line of back ; thick beyond line of sides and hams ; shields on boars too coarse and prominent. Chest — Heart girth. — Large, wide, deep and full ; even under line to the shoulder and sides with no creases ; giving plenty of room for the heart and other organs, making a large girth indicating much vitality. Brisket smooth, even and broad ; wide between the legs and extending well forward, showing in front. Objections : Pinched appearance at the top or bottom, or tucked in back of forelegs ; showing too narrow between the legs, not depth enough back of the shoulder. Brisket uneven, narrow, not prominent. Objections : Narrow ; swayed ; humped ; creasing back of shoulders ; sunfish shaped ; uneven width ; lumps or rolls. Sides. — Full ; smooth ; deep ; carrying size down to line of belly ; even with line of ham and shoulder. Objections : Flat ; thin ; flabby ; uneven surface ; compressed at bottom ; shrunken at shoulder and ham. Ribs. — Long ; well sprung at top and bottom ; giving animal a square form. Ham and rump. — Broad ; full ; long ; wide and deep ; admitting of no swells ; buttock full, neat and clean ; stifle well covered with flesh, nicely tapering toward the hock ; rump slightly rounding from loin to root of tail, same width as back, making an even line with sides. Objections : Narrow ; short ; not filled out to stifle ; too much cut up in crotch or twist ; not coming down to hock ; buttocks flabby ; rump flat, narrow, too long, too sharp or peaked at root of tail. Legs. — Medium length ; strong and straight ; set well apart and well under body ; bone of good size ; firm ; well muscled ; wide above knee and hock, round and tapering below knee and hock, enabling the animal to carry its weight with ease ; pasterns short and nearly upright. Objections : Too short or too long ; weak ; crooked ; too close together ; muscles weak ; bone too large and coarse, without taper ; pasterns long, crooked or slim. belly. Color. — White. Red or black spots in hair disqualify, but blue spots in hide (commonly known as freckles), while objectionable and to be discouraged, do not argue impurity of blood. Size. — Large for age and condition. Boar two years and over, if in good flesh, should weigh not less than 500 pounds ; sow same age and condition not less than 450 pounds. Boars eighteen months old, in good flesh, should weigh not less than 400 pounds ; sows, 350. Boars twelve months old, not less than 350 pounds ; sows, 300. Boars and sows six months old, not less than 150 pounds each, and other ages in proportion. Action. — Easy and graceful; high carriage; active; gentle and easily handled. In males, testicles should be readily seen, and of same size and carriage. squarely under body, wide above knee and hock, and rounded and well muscled below, tapering, bone medium, pasterns short and nearly upright, toes short and firm, enabling the animal to carry its weight with ease 10 Objections : Legs too long, slim, crooked, coarse or short ; weak muscles above hock, and knee bone large and coarse, and legs without taper, pasterns too long bition. CHESHIRE SWINE — STANDARD OF EXCELLENCE Head, short to medium in length, short in proportion to length of body; face somewhat dished and wide between the eyes; ears small, erect, in old animals often slightly pointed forward ; neck short ; shoulders broad and full ; hips broad ; body long, broad and deep ; hams broad, nearly straight with back, and running well down towards hock ; legs long and slim, set well apart and supporting the body on the toes ; tail small and slim ; hair fine, medium in thickness and quantity ; color white. When grown and well fattened, should dress from 400 to 600. Head. — Narrow forehead or "dished nose." Ears. — Thick, coarse or pricked. Coat. — Coarse or curly, with rose ; bristly mane. Skin. — Wrinkled. deformity. Condition. — Any abnormal condition ; barren or blind. Size. — Not two thirds standard weight. Pedigree. — Not eligible to record. outward and forward, knuck small and well set to the head. Objections : Large, coarse, thick, large or long knuck, drooping or not under good control of the animal, or too erect. squarely under body, wide above knee and hock, rounded and well muscled below, tapering, medium bone, pastern short and nearly upright; foot solid, short, smooth, enabling the animal to carry its weight with ease. Objections : Legs too long or too short, slim, crooked or coarse ; . muscles weak or light ; joints coarse, not tapering ; pastern too long, crooked or slender ; foot long, slim, weak or turned up. General outline. — Long and deep in proportion to width, but not massive ; slightly arched in the back, symmetrical and smooth, with body firmly supported by wellplaced legs of medium length 5 Objections. — Black hair, very light or ginger hair, curly coat, coarse mane, black spots on skin, slouch or drooping ears, short or turned-up snout, heavy shoulders, wrinkled skin, inbent knees, hollowness at back of shoulders. The author discusses in this work the general care and management of farm animals rather than the breeds. However, a knowledge of the latter is not altogether excluded since it is necessary in treating of the care and management of farm animals. The method is here adopted of freely inserting pictures of good animals of many breeds, with liberal legends, letting them run as a minor motive throughout the book. By this plan the reader will take away with him some of the main characteristics of the breeds with little effort on his part. The book is a manual, and therefore considers common practical matters in much detail. These practical problems, which confront the stockman whether he be the owner of few animals or of many, have long needed to be systematically and authoritatively treated. In this practical guide on the choosing, feeding, breeding, care and management of horses, cattle, sheep, and swine, is contained that information which hitherto the animal owner has had to cull from numerous sources. By calling attention to the diseases and ailments common to farm animals, the book shows the reader the importance of securing reliable aid when the subject is beyond his knowledge or skill. The work is invaluable as a practical guide in raising farm animals. " Since the effectiveness of the horse and the safety of the master and his family depend so largely upon the understanding between men and horses," says Professor Harper, in his preface, " it seems worth while to give the methods of establishing agreeable relationships careful consideration. It is to promote this that the present volume is written. This is done with the thought that the usefulness of the horse depends on his being readily subservient to his master's will, and the author here sets forth the methods that are most likely to bring this about. Beginning with the foal, each class of horse is considered, and a separate chapter is devoted to the education of the more common classes — the work horse, the trotting horse, the coacher, the roadster, and the saddle horse. " Special attention is also given to the training and subduing of wild horses as well as to overcoming outdoor and stable vices and whims. The book is written from a practical point of view and will be of great service to all those who have anything to do with man's principal beast of burden." With the increasing study of agricultural subjects in the schools has come a demand for a book on Animal Husbandry suitable for use by students of high school age. It is to meet such a need that this book has been written, and in content, style, and arrangement it is admirably adapted to the purpose. It belongs to the Rural Textbook Series prepared under the editorial supervision of Professor L. H. Bailey of Cornell University. In the five parts into which the book is divided the author treats horses, cattle, sheep, swine, and poultry, and each is discussed with reference to breeds, judging the animal, feeding, and care and management. There is also a chapter on the general principles of feeding. Practical questions and numerous laboratory exercises supplement the text and compel the student to think through each subject as he proceeds. The book is extensively illustrated. Designed for use as a textbook, it is also well suited for use as a reference book in schools in which time limitations make it impossible to use it as a text. In his "Genetics" Professor Walter summarizes the more recent phases of the study of heredity and gives to the non-technical reader a clear introduction to questions that are at present agitating the biological world, and which are of particular importance to all those interested in the evolutionary or hereditary problems of breeding. Professor Walter's conception of sexual reproduction is that it is a device for doubling the possible variations in the offspring, by the mingling of two strains of germ plasm. The weight of probability, he concludes, is decidedly against the time-honored belief in the inheritance of acquired characters. Professor Walter also predicts that the key to this whole problem will be furnished by the chemist, and that the final analysis of the matter of the " heritage carriers " will be seen to be chemical rather than morphological in nature. Professor Walter holds, if only modifications of the germ plasm can count in inheritance, and if these modifications come wholly from the combination of two germ plasms, then the only method of hereditary influence is in the selection of parents. breeding of animals or plants given in the agricultural colleges. " I find that it is a very useful study for an introduction to the subject. Professor Walter has certainly made one of the clearest statements of the matters involved that I have seen, and has made a book which students will find very useful because he keeps everything in such entirely simple and clear outlines, and at the same time he has brought the book up to date." — PROFESSOR FREDERIC B. LOOMIS, Amherst College. " I am much pleased with it and congratulate you upon securing so excellent a treatment. It is one of the most readable scientific books I have, and goes unerringly to the fundamentals of our most recent advances in the experimental study of heredity as well as those of the older studies." — PROFESSOR GEORGE H. SHULL, Cold Spring Harbor, Long Island, N. Y. This is not a statement of rules or details of practice, but an attempt to present the main facts and principles fundamental to the art of feeding animals. The book is a valuable contribution to agricultural literature and is worth a place in any library, but especially in one open to rural readers. The author is well known as Director of the New York Agricultural Experiment Station. " A valuable contribution to agricultural literature. Not a statement of rules or details of practice, but an effort to present the main facts and principles fundamental to the art of feeding animals." — New England Farmer. BY PROFESSOR O. KELLNER Authorized Translation by WILLIAM GOODWIN, B.Sc., PH.D., Lecturer on Agricultural Chemistry, and Head of the Chemical Department, SouthEastern Agricultural College (University of London), Wye, Kent. An authorized English translation of the valuable work of Dr. O. Kellner. It explains in simple language the general laws which underlie the feeding of animals and the scientific foundations upon which the principles of animal nutrition rest. " I wish to say that it is one of the most valuable books in the English language on Feeding Farm Animals. The author is extremely lucid in expression and concise in statement. He covers his field in a manner that is well planned and such as will give the reader a most excellent knowledge of the general principles of Feeding." — PROFESSOR CHARLES S. PLUMB, Ohio State University. " Dr. Kellner's standing as a student and investigator in this subject is too high for any words of commendation to be needed, and I feel sure that the translator and publisher have done a service in rendering this work available to English and American students." — PROFESSOR HENRY P. ARMSBY, Pennsylvania State College.	79,474	common-pile/pre_1929_books_filtered	principlespracti00gayciala	public_library	public_library_1929_dolma-0000.json.gz:842	https://archive.org/download/principlespracti00gayciala/principlespracti00gayciala_djvu.txt
CXSCNY9qKuGsT8Q6	Choosing & Using Sources: A Guide to Academic Research	1-Research Questions Whether you’re developing research questions for your personal life, your work for an employer, or for academic purposes, the process always forces you to figure out exactly: - What you’re interested in finding out. - What it’s feasible for you to find out (given your time, money, and access to information sources). - How you can find it out, including what research methods will be necessary and what information sources will be relevant. - What kind of claims you’ll be able to make or conclusions you’ll be able to draw about what you found out. For academic purposes, you may have to develop research questions to carry out both large and small assignments. A smaller assignment may be to do research for a class discussion or to, say, write a blog post for a class; larger assignments may have you conduct research and then report it in a lab report, poster, term paper, or article. For large projects, the research question (or questions) you develop will define or at least heavily influence: - Your topic, in that research questions effectively narrow the topic you’ve first chosen or been assigned by your instructor. - What, if any, hypotheses you test. - Which information sources are relevant to your project. - Which research methods are appropriate. - What claims you can make or conclusions you can come to as a result of your research, including what thesis statement you should write for a term paper or what results section you should write about the data you collected in your own science or social science study. Influence on Thesis Within an essay, poster, or term paper, the thesis is the researcher’s answer to the research question(s). So as you develop research questions, you are effectively specifying what any thesis in your project will be about. While perhaps many research questions could have come from your original topic, your question states exactly which one(s) your thesis will be answering. For example, a topic that starts out as “desert symbiosis” could eventually lead to a research question that is “how does the diversity of bacteria in the gut of the Sonoran Desert termite contribute to the termite’s survival?” In turn, the researcher’s thesis will answer that particular research question instead of the numerous other questions that could have come from the desert symbiosis topic. Developing research questions is all part of a process that leads to greater and greater specificity for your project. TIP: Don’t Make These Mistakes Sometimes students inexperienced at working with research questions confuse them with the search statements they will type into the search box of a search engine or database when looking for sources for their project. Or, they confuse research questions with the thesis statement they will write when they report their research. The next activity will help you sort things out. Activity: Another Way to Think about Thesis Statements Watch this video to see another way to develop your thesis statement. Influence on Hypothesis If you’re doing a study that predicts how variables are related, you’ll have to write at least one hypothesis. The research questions you write will contain the variables that will later appear in your hypothesis(es). Activity: Guess the Question Despite how strong their influence is on the rest of the researcher’s tasks, research questions don’t always appear in a report of the research. Nonetheless, you can usually figure out what the researcher’s research questions were by reading the title and some of the report. Take a look at this article “Getting to the Center of a Tootsie Roll Pop®” [FSCJ login required] and determine what was the students’ research question. Influence on Resources You can’t tell whether an information source is relevant to your research until you know exactly what you’re trying to find out. Since it’s the research questions that define that, it’s they that divide all information sources into two groups: those that are relevant to your research and those that are not—all based on whether each source can help you find out what you want to find out and/or report the answer. Influence on Research Methods Your research question(s) will help you figure out what research methods you should use because the questions reflect what your research is intended to do. For instance, if your research question relates to describing a group, survey methods may work well. But they can’t answer cause-and-effect questions. Influence on Claims or Conclusions The research questions you write will reflect whether your research is intended to describe a group or situation, to explain or predict outcomes, or to demonstrate a cause-and-effect relationship(s) among variables. It’s those intentions and how well you carry out the study, including whether you used methods appropriate to the intentions, that will determine what claims or conclusions you can make as a result of your research. Activity: Quick Check Open activity in a web browser.	1,059	common-pile/pressbooks_filtered	https://openfl.pressbooks.pub/choosingsources2/chapter/influence-of-research-question/	pressbooks	pressbooks-0000.json.gz:10455	https://openfl.pressbooks.pub/choosingsources2/chapter/influence-of-research-question/
nkVKWVCU9SLYFfeT	Art Appreciation	13 Reading: Representational, Abstract, and Nonrepresentational Art Abstract art exists on a continuum, from somewhat realistic representational work to fully nonrepresentational work. Key Points - Representational art or figurative art represents objects or events in the real world. - Romanticism, Impressionism, and Expressionism contributed to the emergence of abstract art in the nineteenth century. - Even representational work is abstracted to some degree; entirely realistic art is elusive. Term - Verisimilitude: the property of seeming true, of resembling reality; has a resemblance to reality Painting and sculpture can be divided into the categories of figurative (or representational) and abstract (which includes nonrepresentational art). Figurative art describes artworks—particularly paintings and sculptures–that are clearly derived from real object sources, and therefore are by definition representational. Since the arrival of abstract art in the early twentieth century, the term figurative has been used to refer to any form of modern art that retains strong references to the real world. This figurative or representational work from the seventeenth century depicts easily recognizable objects–ships, people, and buildings. Artistic independence was advanced during the nineteenth century, resulting in the emergence of abstract art. Three movements that contributed heavily to the development of these were Romanticism, Impressionism, and Expressionism. Abstraction indicates a departure from reality in depiction of imagery in art. Abstraction exists along a continuum; abstract art can formally refer to compositions that are derived (or abstracted) from a figurative or other natural source. It can also refer to nonrepresentational art and non-objective art that has no derivation from figures or objects. Even art that aims for verisimilitude of the highest degree can be said to be abstract, at least theoretically, since perfect representation is likely to be exceedingly elusive. Artwork which takes liberties, altering for instance color and form in ways that are conspicuous, can be said to be partially abstract. Delaunay’s work is a primary example of early abstract art. Nonrepresentational art refers to total abstraction, bearing no trace of any reference to anything recognizable. In geometric abstraction, for instance, one is unlikely to find references to naturalistic entities. Figurative art and total abstraction are almost mutually exclusive. But figurative and representational (or realistic) art often contains partial abstraction.	474	common-pile/pressbooks_filtered	https://library.achievingthedream.org/herkimerartappreciation/chapter/oer-1-4/	pressbooks	pressbooks-0000.json.gz:74206	https://library.achievingthedream.org/herkimerartappreciation/chapter/oer-1-4/
uKIXwiPaRjd4m1my	Biology: an introductory study for use in colleges, by Herbert W. Conn.	PREFACE THIS work is intended to serve as an introduction to the study of botany and zoology. It has been for some time recognized that there is a series of laws and principles which relate both to animal and plant life, and another series of important facts which refer to the relations of animals and plants to each other. In helping to a comprehension of nature, these interrelations are really of more significance than the detailed study of certain animals and plants. But with the tendency shown frequently in our educational system, to divide biology into zoology and botany, there is danger that these fundamental truths and interrelations be neglected, since a consideration of them belongs strictly neither to zoology nor to botany. To students of the age of those in secondary schools, the study of such concrete facts as the description of animals and plants is most attractive; and for them, courses in elementary botany and zoology are eminently appropriate. But to students of the greater maturity of college grade, the study of the fundamental biological laws is more stimulating and better calculated to develop the thinking powers. It is, therefore, the author's belief that the proper way for older students to begin the study of the great department of biology is to consider the fundamental principles relating to both animals and plants, before either of these groups is studied in detail. After the student turns his attention more particularly to zoology or botany, he is likely to be engrossed in the details of the life and structure of animals and plants, and so almost inevitably neglects the broader fundamental laws which should correlate the phenomena of life as one science. Unless, therefore, the foundation principles of biology be studied as an introductory course, it is very probable that they will be neglected. For this reason, this text has been provided as an introductory survey of the laws which apply to both animals and plants, and those principles which coordinate and correlate them. It is hoped that it may have some influence in developing the study of the fundamental principles of biology as an introductory course, thus supplanting the old custom of plunging the student at the outset more specifically into zoology or botany. It is designed that this work shall be an elementary study of biology, on a par with, and parallel to, elementary physics and chemistry. Logically it should follow, rather than precede, these two sciences, although it may be taken simultaneously with them. Its place in a curriculum should, therefore, be about the same as that of elementary physics and chemistry; and as developed in the following pages, it belongs to the beginning of college work. In preparing these pages, it has been recognized fully that a certain amount of laboratory work is necessary in order that the student may properly understand biological phenomena. It is also appreciated that, with the present development of the teaching of biology and the present equipment of many of our institutions, it is frequently impossible to introduce any extended laboratory work, on account both of insufficient equipment and lack of time in the already crowded courses of study. For this reason, the chapters have been arranged so that, where necessary, they can be used without the accompanying laboratory demonstrations. Although this is an undesirable method of studying biology, the author believes that the biological principles covered in the following pages may be comprehended in a fairly satisfactory manner, even though the student does not have the opportunity of making the laboratory tests. It is hardly necessary to state, however, that as much practical laboratory work as possible should accompany the study of the text. For this reason, outlines of the correlative laboratory work have been added at the end of the chapters. In all cases where laboratory work is possible, students should be required to make careful drawings of the objects studied. Wherever time permits, the laboratory work outlined here should be expanded by instructors. (For more detailed laboratory directions than can be given here, reference should be made to the many excellent handbooks of zoological and botanical laboratory work, a few of which are mentioned in the brief bibliographies at the close of the chapters.) In place of the ordinary index there will be found at the close of the book a glossary-index. In it are given brief definitions of all the technical words used in the book, with derivations and with page references. To make this more valuable as a reference glossary, some common biological words which do not chance to be used in the text are defined. These are easily recognized from the fact that they have no page numbers. APTER PAGE I. THE SCOPE OF BIOLOGY . . . . . 1 The New Biology and the Old. The Fundamental Properties of Living Things. Chemical Composition of giving Tissues. Origin of Life. The Biological Sciences: Morphology. Physiology. Zoology and Botany. II. CELLS AND THE CELL THEORY . . , . 26 Organisms. The Cell as the Unit of Organic Structure. Cell Structure. Cell Substance or Protoplasm. The Nucleus. The Centrosome. The Cell Wall. Cell Functions. History of the Cell Doctrine: 1. The Early Conception of the Cell (1839-1861). 2. Protoplasm and the Mechanical Theory (1861-1885). 3. The Nucleus and its Significance (1880 to the present). What is Meant by Protoplasm. III. UNICELLULAR ORGANISMS 52 Animals: AmcebcL Paramedwn. Plasmodium Malarice. Chilomonas. Pandorina. Intermediate Organisms: Peranema. Euglena. Plants: Pleurococcus. Saccharomyces — Yeast. • Bacteria. IV. CELL MULTIPLICATION AND THE CELLULAR STRUCTURE OF ORGANISMS .... 85 Cell Division or Karyokinesis. Unicellular and Multicellular Organisms. Penitillium, a Simple Multicellular Plant. Other Species of Molds. LAR PLANT . . .103 The Castor Bean (Ricinus Communis). Gross Structure. Structure of the Stem. Structure of the Root. Structure of the Leaf. Reproductive Organs. VI. THE PHYSIOLOGY OF A TYPICAL PLANT . .126 Photosynthesis or Starch Manufacture. Metastasis. Photosynthesis and Metastasis Contrasted. Miscellaneous Functions of Plant Life. General Life Functions of Animals. Animal Biology. Hydra Fusca, a Simple Multicellular Animal. The Relation of the Whole Organism to its Different Parts. GANISMS 217 The Differences between Animals and Plants. Contrast between the Activities of Animals and Plants. The Mutual Relations of Organisms. Nature's Life Cycle. REPRODUCTION : SEXUAL AND ASEXUAL METHODS 238 General Types of Reproduction. Reproduction in Unicellular Organisms. Reproduction in Multicellular Organisms. Division without Cell Union. Multiplication by Cell Union. The Union of the Sex Bodies or Fertilization. The Relation of the Chromatin to Heredity. The Purpose of the Union of the Sexes. METHODS. ALTERNATION OF GENERATIONS 262 Summary of the Methods of Reproduction. Origin of Sex Union. Distribution of Asexual Reproduction. Distribution of Sexual Reproduction. Reproductive Bodies or Reproductive Cells. Cross Fertilization the Rule. Alternation of Sexual with Asexual Methods of Reproduction. XV. THE SOURCE AND NATURE OF VITAL ENERGY . 292 Matter and Energy. The Conservation of Energy. The Transformation of Energy. The Living Organism as a Machine. The Life of a Plant. The Life of an Animal. The Origin of the Living Machine Not Explained. The Forces Which Have Produced Organisms. Conformity to Type. Divergence from Type. XIX. CLASSIFICATION AND DISTRIBUTION . . . 364 Classification (Taxonomy) . The Significance of Classification. An Outline of the Classification of the Living World. Distribution of Animals in Space and Time. Distribution of Organisms in Time: Paleontology. THE NEW BIOLOGY AND THE OLD BIOLOGY is often described as the most recent of the sciences, despite the fact that it was one of the first to be studied. Four centuries before Christ, animals were dissected and described by Aristotle, and from that time on, the study of living things has never ceased. In the last half century, however, the study of vital phenomena has assumed a new aspect. Formerly animals and plants were studied only as objects to be classified and named; now they are studied as objects to be explained. Progress of Scientific Thought. — This new method of biological study is only another expression of man's changed attitude toward all natural phenomena. In early times, people imagined that all the phenomena of nature which they could not understand were produced by gods. One god caused the winds; another the motions of the sun and stars. Gradually these conceptions have been changed by the attitude of modern science. First, the motions of the heavenly bodies were explained under the general law of gravitation. Then, the mysterious phenomena of fire and of electricity were comprehended under the laws of chemistry and physics. Later, the various changes on the earth's surface, such as the formation of mountains, of valleys, of rivers, and of plains, were explained as the result of the ordinary forces of nature. In all this there has been a progress in one direction, namely, toward the explanation of natural phenomena by natural forces. The most recent of the natural phenomena to be studied with this end in view, are those associated with living 2 BIOLOGY animals and plants. The question whether the activities of animals and plants can be explained by the same forces found elsewhere in nature, and the attempt to answer this question in the affirmative, form the basis of the new science of biology. Modern biology is thus something more than the study of animals and plants as dead objects to be collected, named, and classified. It is a study of animals and plants in action; as living beings to be related to their environment. It is this attempt to explain life processes which may be said to have raised biology to the rank of a new science. THE FUNDAMENTAL PROPERTIES OF LIVING THINGS Distinction between the Living and the non-Living. — Since biology (Gr. bios = \ife -\-logos = discourse) is the science of living things, we must first ask how living things may be distinguished from non-living. While it is a comparatively easy matter to recognize the distinction, it is difficult to draw it sharply. Indeed, some biologists are of the opinion that no rigid line can be drawn, and that there are some states of matter which are halfway between the living and the non-living. Whether or not this be so, it certainly is true that between most forms of matter which we call alive and those which we call nonliving, there is a marked and recognizable difference, although it may be difficult to define it accurately. Four or five fundamental properties are characteristic of life: 1. Activity. — The most noticeable difference between the living and the non-living is in the presence or absence of spontaneous activity. If we wish to find out whether any given body is alive, we watch it carefully to see if it shows any power of independent activity, and if it does so, we call it alive. If the object, a seed for example, seems to be perfectly dormant, we may put it under conditions in which, if alive, it will develop activity. If it then begins to grow into a plant we say that the seed was alive at first but dormant. If, however, it fails to show any power of developing into a plant when placed THE SCOPE OF BIOLOGY 3 in proper conditions, we conclude that the seed is not alive. Hence the best criterion that we have for separating the living from the non-living is to determine whether or not the body in question either shows any signs of independent activity or, when put under proper conditions, may be made to show any signs of such activity. Automatic activity. — The simple fact of showing activity is, however, not enough to serve as a criterion of life. Other things besides living beings have the power of activity. A watch, or a locomotive, or a steam engine certainly shows activity, and yet none of these is alive. There is, however, one distinction between the activity of such machines and the activity of a living organism. Machines show activity only when they are started into action by some outside influence; while a living organism develops activity from its own internal, independent power. With this modification, the first criterion that we have for distinguishing the living from the non-living is the power of developing automatic activity, and only objects possessing this power do we speak of as being alive. 2. Death. — The fact that living things show automatic activity has a converse side. This activity may cease, the objectlosing its power of showing spontaneous activity. This constitutes the phenomenon spoken of as death. To define either life or death has proved a puzzle to both science and philosophy. For our purpose, however, they can be fairly well defined as follows: By life, we mean the possession of the power of showing spontaneous, automatic activity; by death, we mean the disappearance of this power. Why an animal or plant, when it dies, loses this power, we do not know. In some cases it is undoubtedly because the complicated machinery which composes the body is injured and consequently cannot work properly. This we find true also in the case of ordinary machines. If a locomotive should burst its cylinders, it would no longer be able to run. If a watch has its mainspring broken, it is thrown out of adjustment and consequently does not show activity. So in regard to living things; the inability to show further activity may undoubtedly be attributed to the fact that the machinery is out of order. If, for example, the beating of the heart ceases for any length of time, life activity must cease, because life activity is dependent on the circulation of the blood. Thus, in many cases we know positively that death comes from the breaking down of the machine. Whether death means anything more than the breaking down of the machine; whether anything is lost which can be called the life force, is one of the questions over which philosophy and biology have puzzled for long years, and upon which they have not reached any definite conclusion. 3. Growth. — All organisms disintegrate by oxidation and waste. When a piece of wood reaches the required temperature to unite with the oxygen of the air, it burns. Waste products appear as gases and ashes, and the wood disappears. In a similar way, by union with oxygen the living body is being constantly converted into waste products which are given off from the body as excretions. As a result the organism is constantly disintegrating. This would inevitably result in the disappearance of the organism if it were not for the opposite power of reintegration, or growth. All living things have the power of growing, and no object that is not alive has this power. It is true that, under some circumstances, crystals may increase in size, and this is sometimes referred to as a growth of the crystals; but it is a totally different kind of growth from that which we find in living things. In the case of the crystal, the new material is simply laid upon the outside of the old, layer after layer, and the apparent growth is really an increase in size, by the process of accretion. In the growth of the living organism, material is taken inside of the body, and there it is transformed into compounds like those of the living organism which has absorbed it. Thus the living organism increases from within, — a type of growth spoken of as intussusception (Lat. intus = within + suscipere = to take up). With this understanding of growth we can state that nothing grows except living things. As the result of their activities, living things are constantly wasting away; but by growth they repair and keep pace with their own wastes and remain in a practically constant condition, in spite of their ceaseless activity. In time, however, the disintegrating tendencies surpass the powers of repair, and the organism dies of old age. 4. Reproduction. — The power of reproduction is found only in the realm of the animate world, for only a living organism can produce another like itself. Inanimate things cannot reproduce their kind. As a result of this power of reproduction, held in common by all things possessed of life, there is a constant replacement of the individual, a constant wearing out and death, a constant rebirth and growth, the new organism ever replacing the old as it disintegrates and disappears. There is a constant tendency to undergo cyclical changes present in all manifestations of life. 5. Consciousness. — Consciousness is characteristic of some living bodies, but is probably not universal among them, for it is practically certain that life occurs in many places without consciousness, although some theorists have endeavored to argue that all forms of life, even the plants, have a very dim form of consciousness. This is very doubtful, and we cannot regard consciousness as universally characteristic of life. Wherever consciousness is found, however, it indicates the presence of life, and thus may be deemed one of the most important signs of life. CHEMICAL COMPOSITION OF LIVING TISSUES Chemical Elements in Living Tissues. — Although there is a large variety of chemical compounds found in living animals and plants, nevertheless there is a certain uniformity among them. All animals and plants are made up primarily of a small num- her of elements, nine chemical elements being ordinarily present in living things, four of which predominate, while the other four are present only in small quantities. They are as follows : — OF THE CHIEF ELEMENTS MAKING UP A LIVING BODY things. Only very small amounts of these elements are present, although calcium is found in animals in considerable quantities in the bone. Figure 1 shows diagrammatically the relative proportions of the chief chemical elements in the animal body. Oxygen, carbon, hydrogen, and nitrogen constitute about 98 per cent of the animal body and not far from the same proportion of the composition of the body of most plants. These four elements also constitute by far the largest proportion of the material present in the earth's crust; so that the living body is made of the same materials that are most abundantly present in the inanimate world around us. Chemical Compounds in Living Tissues. — It is perfectly evident that the elements enumerated do not exist in the living body as uncombined elements. Two or more of them are always united as chemical compounds to form a substance different from either of them. The chemical compounds that are present in the bodies of animals and plants are of an endless variety; but a few general types are most widely present and may be regarded as the fundamental compounds of living things. These compounds are important, since they enter into the food of all animals. They are as follows: proteids, carbohydrates, fats. Proteids. — Proteids are extremely complex substances, composed chiefly of the elements: carbon, oxygen, hydrogen, and nitrogen, but containing also in small proportions sulphur and the other elements that have been enumerated above. They are by far the most complex substances in living things; that is, in a proteid molecule, there are present more chemical atoms than are found in a molecule of any other substance existing in the animal body. The exact chemical composition of proteids is not known and it suffices for our purpose to state, that they are composed of a highly complex combination of the elements we have mentioned, so united that hundreds of atoms are probably always combined to make a molecule. Some idea of their complexity may be obtained from the fact that one chemist gave as a formula for egg-albumen, C2o4H322N52O66S2 (a formula too complicated to have any real meaning); and indeed, no two chemists agree upon the chem- ica! composition of any proteid. The following are the bestknown proteids: albumen, the white of an egg; myosin, the lean part of the meat; casein, the curd of the milk; gluten, the sticky substance in flour; legumen, a similar sticky material present in peas and beans. Besides these, there are many other proteids present in animal and plant tissues. Living tissue is almost entirely proteid in character. Sources of proteids. — Since living things are made up largely of proteids, we next inquire into the source of these proteids. As will be noticed later, green plants can combine the gases of the air with the water and certain minerals obtained from the soil, and thus manufacture their own proteids. Animals and colorless plants (fungi) are totally unable to manufacture proteids from inorganic compounds. Hence it follows that animals and the colorless plants depend upon the green plants for their proteids, which is simply another way of stating the fact that animals require plants for their food. Although unable to manufacture proteids, colorless plants and animals are, however, able to modify them more or less, having the power to transform one kind of proteid into another. If, for example, an animal is fed with the white of an egg, it can transform this proteid into the proteid of muscle, thus changing albumen into myosin. Since animals are unable to manufacture muscles from any substances but proteids, it follows that they are obliged to have proteids in their diet. Carbohydrates. — Starches and sugars are the best-known examples of carbohydrates. They are much simpler than proteids, consisting of only three chemical elements: carbon, oxygen, and hydrogen. These elements are combined in molecules with the following formulas : C6Hi0O5 (starch) and C6Hi2O6 (sugar). There is quite a large number of starches and sugars, differing from each other in some respects, but these formulas are typical of their general nature. It will be seen from the formulas that the difference between the molecules of starch and sugar is in the presence, in sugar, of H^O in addition to the group contained in the starch molecules. H^O is a molecule of water; and hence we say that if a molecule of water is added to a starch molecule, it will convert it into a sugar molecule. It must not be understood, however, that this can be done by simply adding water to starch, for the two will not combine. There are methods (see page 306), however, by which they can be made to combine, and under these circumstances starch can very easily be converted into sugar. Among the different types of sugars, there are two of especial importance. One of these is grape sugar, also called glucose or dextrose. These three names are closely related, although not exactly identical. The formula for these is also CeH^Oe. The other type is cane sugar, obtained from sugar cane or the sugar beet. The formula for this is C^H^On, which, as will be noticed, is nearly, but not quite, twice the formula of the grape-sugar molecule. By the addition of a molecule of water it is possible to break a molecule of the cane sugar into two molecules of the grape-sugar type, according to the following equation: Ci2H22Oii+H2O = 2C6Hi206. This is commonly spoken of as inverting the sugar. Sources of carbohydrates. — Carbohydrates come almost wholly from the vegetable world. Green plants manufacture starch in their leaves by combining the carbon dioxid gas which they absorb from the air with the water which they absorb from the soil. This starch is very easily converted into sugar within the plant, and then carried to various parts where it may be stored, either in the form of starch or sugar. It is subsequently used by the plant as food, or, if the plant is consumed by animals, it serves as their food. So far as known, there is no other source of carbohydrates in nature besides the green plants, and as all animals and all plants consume carbohydrates, it is plain that the whole living world is dependent upon the green plants for carbohydrates. food products. Fats contain the three elements, carbon, oxygen, and hydrogen, in this respect agreeing with the carbohydrates. They are, however, considerably more complex than carbohydrates, a molecule of fat containing more atoms, as is shown by the formula C5iHio4O9, which represents a common fat. When treated by a simple chemical method, fats are broken up into two substances, one of which is called glycerine and the other a fatty acid. Sources of fats.— ¥ at can be manufactured by either animals or plants out of other foods. If an animal is fed upon proteids or carbohydrates, it can manufacture fat from them; and plants are able to make fat out of the food materials which they absorb from the air and water. The table on page 11, which illustrates the composition of a few of our common foods, shows that our ordinary diet contains a fair proportion of each of these three foodstuffs. It will also be seen from this table that the largest proportion of proteids comes from animal foods, while the largest proportion of carbohydrates comes from plant foods. Perhaps no feature of modern biology is more important than the acceptance of the theory that every living thing comes from a living source. All living animals and plants with which we are familiar to-day have originated from previously existing life. The living animal comes from the egg that was produced by another living animal; the plant comes from a seed that was produced by another living plant. But the question of the primal origin of life is sure to intrude itself upon our minds, and we are forced to ask whether living things can be, or ever have been produced by any other means. Did there ever occur, or does there occur in the world to-day, a spontaneous generation of life? In other words, did a living thing ever arise from some source which was not alive? So far as our knowledge of nature is concerned, there are no means of starting new life except from previously existing life. Spontaneous Generation or Abiogenesis. — This idea of spontaneous generation, or abiogenesis (Gr. a = without + bios = life -f genesis = generation), has been before the scientific world for centuries. The ancients in the time of Aristotle, and for centuries later, had no especial question in regard to the matter, and took it for granted that living things did come from inanimate matter. Virgil tells us of bees coming from the flesh of bullocks; Ovid recounts that slime begets frogs; and many centuries afterwards, we read that water produces fishes and that mice can come from old rags. Although to-day these ideas seem nonsensical, once they appeared perfectly logical. Experiments of Redi. — This idea that life could come from non-living matter was held without question during the earlier centuries, and indeed until about the 17th century. In 1680 an Italian named Redi made an observation which led him to what was at that time a rather startling conclusion. It had previously been observed that fly maggots made their appearance in decaying flesh, and it was taken for granted that they developed spontaneously. Redi noticed flies hovering over meat, and demonstrated by experiments that if the flies were kept away by simply tying paper over a bottle containing the meat, maggots could never develop in it. A little further study proved that the flies laid eggs on the meat which developed into fly maggots. From this observation he drew the farreaching conclusion that spontaneous generation did not occur and that all living things came from living ancestors. This conclusion started a dispute which lasted for two centuries and was not fully settled until about 1875. For the conclusion of Redi, that all living things came from living ancestors, was vigorously disputed by the adherents of the old idea that life could arise spontaneously. Many ingenious experiments were devised to settle the question. It did not take, long to prove that so far as the larger animals and plants were concerned, the conclusion of Redi was correct. But just at this time the newly invented microscope was beginning to show a world of invisible life, and in the various bottles and flasks used in these early experiments, a large number of microscopic forms of life appeared in spite of all attempts made to prevent their entrance. Although in a piece of meat no fly maggots developed unless flies had previous access to the meat, innumerable microscopic forms of life did appear in it, in spite of all efforts to exclude them, even when the meat was carefully and hermetically sealed. Some of the early experimenters naturally concluded that these microscopic forms of life appeared spontaneously, while others insisted that these little organisms had found entrance into the sealed vessels from the outside, in spite of all precautions taken to keep them out. Great ingenuity was shown in devising experiments for settling this question. The results obtained by different experimenters were in great conflict for over two centuries, and apparently equally good evidence sealing hermetically, to guard against the entrance of any form of microscopic life from without. But even under these conditions it was frequently found that microscopic life made its appearance in the sealed vessels ; Fig. 2. It proved very difficult to be sure that nothing was left Steam produced by boiling passed out through the tube, but upon cooling was drawn in again through the heated coil, which sterilized it. alive in the material after boiling, — i.e., that it was sterile, — and to be sure that the sealing was effectual. Two names especially connected with this dispute were Needham, in 1749, and Spallanzani, in 1777. Needham believed firmly in spontaneous generation, while Spallanzani insisted that the microscopic organisms that appeared in these experiments were either there originally and not killed by the boiling to which the material had been subjected, or had found their way into the solutions through microscopic cracks left by the imperfect sealing. Pasteur and Appert. — In the middle of the last century the French scientist, Pasteur, carried out a series of experiments and attained results which conclusively disproved the theory of spontaneous generation. But the long debated question would not be settled even then. It is a curiously interesting fact that, while scientists were disputing over this matter, the question had, for practical purposes, actually been settled by Appert, who in 1831 had discovered the method of preserving animal and vegetable foods by the means of heat and sealing, — the method used by the canning industries of the present day. But the significance of this practical discovery was not appreciated, and the dispute continued even after Pasteur's work, the advocates of spontaneous generation continuing as insistent in their claims as ever. The settlement of the question was not reached until the English physicist, Tyndall, devised a new and ingenious method of experimenting which so satisfactorily guarded all sources of error that criticism was silenced. Indeed, so convincing were his experiments that his conclusions have practically never been questioned. Tyndall's Experiments. — Briefly, Tyndall's method of experimenting was as follows: An airtight box was constructed, rectangular in shape and provided at either end and in front with glass windows. Into the top of this box passed small glass tubes which had been thrown into several curves, through which the air was allowed to enter freely; Fig. 3 a. For description see text. floated against the side or top of the box would be caught in the glycerine. In this way Tyndall argued that he could obtain, in time, air perfectly free from germ-bearing particles. He did not wish to begin an experiment until the air in the box was absolutely free from dust, and in order to determine this point the two glass windows at the end of the box were used. A ray of light was thrown through the box, in at one window, and out through the other. Thus, any dust particles that remained floating in the air of the box would be illumined and made clearly visible through the window in front. At first there were many dust particles to be seen floating in the air; but after the box had remained quiet for several days, the ray of light was invisible as it passed through the box, proving that no floating dust particles were present to be illumined. When this condition was reached Tyndall assumed experiment. At the bottom of the box were a series of tubes whose mouths opened into the box but whose lower ends projected below; Fig. 3 b. By means of the long tube, c, which could be moved to and fro (since it passed through a rubber diaphragm, d), all the test tubes could be filled successively with any of the solutions with which he wished to experiment. In these tests, Tyndall used various materials: old meat, old cheese, hay infusion, etc., besides many other substances that previous experimenters had used in their attempt to settle the question. After filling the tubes with these various materials, they were heated to a temperature sufficiently high to destroy all life that they might have contained in the beginning. This was easily done, since the lower end of the tubes projected below the level of the box and could be very easily put into a bath of oil or brine, and heated to any desired temperature. Any steam or vapor that might arise from the open end of the test tube would pass into the box and readily find exit through the glass tube at the top. Upon cooling, a fresh supply of air would be drawn back into the box through the curved tube a, but, as already indicated, no dust particles would find entrance. Having thus, by heat, killed any living organisms that might be in the solutions to be tested, he again set the boxes aside and watched day by day to see what would happen. Since everything was clearly visible to the eye, it was possible to determine very quickly and surely whether any living organisms developed in the test tubes. Tyndall's care in his experiments was so great that they were quite beyond criticism. His experiments showed the cause of previous errors and explained why there had been such conflict in the earlier experiments. He demonstrated among other things that some forms of life, called spores, might remain alive in boiling water for some time. This conclusion had been previously reached by others; but Tyndall proved definitely that while a temperature below boiling is sufficient to kill active germs, the spores stand a temperature of boiling for a long time, and hence boiling does not sterilize liquids. Since previous experimenters had assumed that all life was destroyed by boiling, they had been contented with the simple boiling of the liquid to eliminate any organisms that might have been there originally. If, therefore, any of these resisting spores chanced to be in their solutions, they would subsequently develop; and from this fact the experimenter might reach the erroneous conclusion that the living organisms coming from these spores developed spontaneously. Tyndall carefully eliminated all of these errors and established the following important conclusions. No evidence for spontaneous generation exists and the success of an experimenter in obtaining any evidence of spontaneous generation is in inverse proportion to the care with which he performs his experiments. This statement has stood almost unquestioned by biologists since it was first promulgated in 1875; and during the last thirty years the work of thousands of experimenters in the science of bacteriology has only confirmed the accuracy of Tyndall's conclusion. We must accept the fact that whenever any living animal or plant, no matter how small, makes its appearance in a solution, originally there was present in this solution a living germ which started the development of the organism by the process of ordinary reproduction and growth. At the present time, therefore, there is no shred of evidence that, under any conditions which we can produce, life can arise spontaneously. The Primal Origin of Life. — The conclusion that spontaneous generation does not occur to-day, leaves unanswered the question of the primal origin of life. It has been a disappointment to biologists to be obliged to admit that they can find no evidence for the theory of spontaneous development, since at some period in the history of the world, life must have made its appearance for the first time. In an early period of the world's history, the earth was a hot, molten mass, and under these conditions no living matter could exist. It follows, then, that life must have made its appearance after the earth had sufficiently cooled. Biology, in endeavoring to explain life by natural forces, has been eager to believe that in these earlier conditions of the world the first living thing may have appeared as the result of natural law. The fact that biologists have almost universally accepted Tyndall's conclusion that no evidence for spontaneous generation exists, is thus a testimony, both to the truth of this conclusion and to the honesty of the scientists who have accepted it. They would have much preferred a conclusion of the opposite kind. The majority of biologists, however, believe it to be logically necessary to assume that at some time in prehistoric ages, the first living thing appeared from a source which was not living. While accepting the fact that abiogenesis does not occur at the present day or under present conditions, biologists still claim that we have no means of knowing what may have occurred under different conditions in earlier eras of the world's history. Thus, the problem of the primal origin of living matter still remains unsolved. THE BIOLOGICAL SCIENCES Since the science of biology deals with all living matter, it might broadly be defined as the study of life in all its phases. With this comprehensive definition, biology can be made to cover nearly the whole field of human knowledge — most sciences and even philosophy — including not only everything which relates to the life of man, but all that concerns the life of the animal and plant world as well. But for practical convenience in study, the field of biology is usually restricted to a group of definitely related sciences, — the so-called biological sciences, — and although within this group there are to be found many ill-defined boundary lines, and much overlapping and division into sub-groups, the sciences which compose it may be enumerated as follows: morphology, with its sub-groups: anatomy, histology, taxonomy, distribution, structural embryology; and physiology, with its sub-groups: physiology proper, functional embryology, psychology, ecology, and sociology. (See reference chart, p. 21.) MORPHOLOGY Morphology (Gr. morphe = form + -logia = discourse) is that branch of biology which deals with the structure and form of animals and plants. It may be divided into five sub-heads: 1. Anatomy (Gr. ana = up + temnein = to cut) is the study of all of the grosser structure of animals and plants, that can be seen and dissected without the aid of the microscope. 2. Histology (Gr. histos = a web + -logia) is the study of the minute structure of animals and plants which is disclosed only by the aid of the microscope. It is sometimes called microscopic anatomy and deals chiefly with cell structure. 3. Taxonomy (Gr. taxis = arrangement + nomos = law) is the study of the relations of the organisms to each other and includes the classification of species. 4. Distribution is the study of the geographical distribution of organisms at the present time, and also their distribution in the past as disclosed by geology; to the latter study is given the name paleontology. 5. Embryology (Gr. embryon = an embryo + -logia) is the study of the development of the organism from the egg to the adult life. It is also called ontogeny (Gr. on (ont) = being + -geneia = producing) in distinction from phytogeny (Gr. phylon = race -\--geneia = producing), the development of the race. Physiology (Gr. physis = nature + -logia) is the study of the activities or functions of organisms. Its scope may be best understood by its division into sub-heads: 1. General physiology. Physiology deals primarily with the functions of the different organs. Correctly used, it should include the functions of all animals and plants. Since, however, human physiology has been so much more studied than that of other animals, the term physiology usually refers to mankind. When the study extends to other animals or to plants, it is designated respectively as animal physiology and plant physiology. the embryo, it then belongs to the domain of physiology. 3. Psychology (Gr. psyche = soul + -logia) is the study of the functions of the brain. It includes not only the study of the human brain but the brain activities of other animals as well, under the term comparative psychology. 4. Ecology (Gr. oikos — house -f -logia) is the study of the relations of organisms to their environment. This includes their relations to inanimate nature as well as to animate. The term ecology is now more widely applied in relation to plants than to animals. Ecology includes sociology (Lat. socim = a companion + Gr. -logia), which is the study of the interrelations of animals of the same species. This, however, is chiefly confined to the human race, the term sociology usually referring to mankind. There are, however, some animals like ants, bees, etc., that have social relations, and the term sociology might be extended to them. ZOOLOGY AND BOTANY The general term zoology includes any of the biological sciences when studied in their relation to animals, and the general term botany, when they are studied in their relation to plants. the following tests: 1. Place a little of the albumen solution in a test tube and boil, noting that a precipitate appears; that is, the albumen coagulates. Repeat this test, heating the albumen in a test tube in a water bath, determining, by a thermometer placed in the test tube, at what temperature the coagulation occurs. 2. Add a little strong HNO3 to some of the albumen in a test tube. A precipitate appears. Boil, and the precipitate will turn yellow. Allow it to cool and add enough ammonia to neutralize the acid and it will turn a deep orange. This is known as the xanthoproteic test for proteids. 3. To a weak solution of albumen add a few drops of NaOH and a few drops of a 1% solution of CuSO4; heat gently and the solution will turn blue if ordinary proteids are present, but if peptones are present it will show a reddish color. of starch. Casein.— Add a little 2% HCL to a few c. c. of milk. A curd will form whioh can be separated from the liquid by allowing it to drain through cheesecloth. The curd is the proteid, casein. Myosin. — Soak some chopped beef in cold water for half an hour; stir and filter through cheesecloth. Boil the filtrate, and a mass of myosin will appear, which was dissolved in the cold water but is coagulated by heat. Fibrin. — This is a proteid formed from blood. It may be obtained by collecting freshly drawn blood and stirring it immediately with a piece of wire gauze for about ten minutes. A mass of fibrin will collect on the wire, and it will be found that the blood will not subsequently clot, the removal of the fibrin preventing it. CARBOHYDRATES Starch. — Rub up a little starch (potato starch is best) in an evaporating dish with a considerable quantity of water. Place a few drops in a teat tube and add a little iodine solution. The starch will turn blue. Examine a little of the starch water under a microscope. Sketch some of the starch grains. Make a thin section of a bit of potato with a razor and examine under a microscope, noting the starch grains. Add a little iodine solution and again examine with a microscope. Boil the starch water over a flame. As it comes near to the boiling point the mass will become thick and pasty (starch paste), due to the bursting of the starch grains by heat. Place a little under the microscope and look for grains. Add to the paste a little iodine and it will turn a brilliant blue. Test for Sugar. — Put a little glucose or dextrose in a test tube containing a considerable quantity of water. Add to this a few drops of weak H2SO4 and a few drops of NaOH; boil. The presence of sugar is determined by the appearance of a brownish red precipitate, which goes through a series of color changes, but finally remains as a brownish red sediment at the bottom of the tube. Fat Emulsion. — Fat has the property of being readily divided into minute particles which, when mixed with water, float in the liquid, forming what is known as an emulsion. Place a few drops of olive oil in a test tube half full of water. The oil will rise to the top of the water and appear as a clear yellowish layer. The whole contents of the tube will turn a milky white, and upon being allowed to stand the milkiness will remain for a long time. Eventually, however, the fat again separates from the water. This milky appearance is produced by the fact that the fat has been divided into minute particles that float through the water and refract the light in such a way as to give a white color. This is called an emulsion. ORGANISMS ONE characteristic feature of living matter is that it is not indefinitely distributed around the world, but is always associated in distinct units or individuals. In other words, there is no life apart from individuals. These units always contain different parts, each with a distinct function. This is very evident among well-known animals and plants. The human body possesses a heart, a stomach, a brain; and a tree has roots, leaves, flowers, etc. These different parts are called organs ; and because it possesses organs, a living being is called an organism. While it is true that practically all living things do have organs, some of the lowest are so small that no organs have yet been found in them, as for example, bacteria; see Fig. 7. It is probable, however, that these do have organs if we were only able to see them; at all events, the term organism is extended to all living things whether they possess evident organs or not. From the word organisms is coined the adjective organic, that is, pertaining to organisms. Organic substances have been produced by living beings, while inorganic substances have no connection with living things. Bone, muscle, wood, sugar, coal, etc., are organic; while stones, water, and air are inorganic. Nearly all organic substances contain carbon and are capable of being burned, while inorganic substances usually contain no carbon. THE CELL AS THE UNIT OF ORGANIC STRUCTURE The slightest familiarity with the larger well-known animals and plants shows not only that they are made up of different organs, each with its definite duty to perform, but also that these organs are composed of different parts, each having its specific CELLS AND THE CELL THEORY function. The stomach has its muscles and its secreting glands; the foot has its muscles, bones, tendons, ligaments, nerves, etc. The different kinds of substance which form the organs are known as tissues, and usually each tissue contains only one kind of material and has but one kind of duty to perform. For example: muscles, bones, glands, nerves, and tendons, each represent a distinct tissue; each has its special function in the organ, and each is different from the other. Muscles have the power of contraction, bones are for support, etc. By studying these different tissues under the microscope we shall find that they, too, are made up of minute parts, called cells, and that in most instances iNG CARTILAGE TISSUE each cell is essentially like all the other cells of the same tissue. This may be shown by examining Figures 4 to 6, in which several kinds of tissue appear, each made ture of living things has been carried at present; for while each cell is made up of parts, life as a whole seems to be found only where we have the whole structure of the cell developed. In other words, the cell is the simplest form in which life occurs, and is, in this sense, the ultimate unit of living structure. While an organ may contain many different kinds of cells, each tissue is, as a rule, made of but one kind of cell. The cells of the bone, for example, are all essentially alike, and so, too, are the cells of muscles and glands. The different cells in the same tissue may differ in shape and size; but these differences are only superficial ; fundamentally the cells forming a single tissue are alike. Therefore, if we define a cell as the ultimate unit in the analysis of living structure, we may define a tissue as an aggregate of similar cells, all having similar functions; see Figs. 4, 5, and 6. While the form, structure, and size of cells present an almost endless variety, in both the animal and plant worlds, nevertheless, all cells have in common certain general parts. Thus we may speak of the structure of a cell in general, recognizing that all living cells of both animals and plants, in spite of their differences, conform essentially to the type of an ideal cell. CELL STRUCTURE The description given below is not that of any particular cell, but rather that of a typical or ideal cell. Though a cell exactly like that described will not be found, it resembles closely the cell which forms the egg of certain animals, and in essential structure is like all cells found in animals and plants. MAGNIFIED Showing the complex internal structure with bodies supposed by some to be nuclei. At o one cell shows what resembles karyokinetic division. FlG. 8. NlTELLA A, about natural size, showing nodes and internodes; B, one of the internodes more magnified. The part enclosed by brackets, between the two rows of leaves, is a single cell. Structure. — When protoplasm is examined under the microscope it is not found to be a homogeneous jelly, as was at first thought, but to have an intricate structure which is only partly disclosed by the microscope; Fig. 11. The exact structure of this cell substance has not been fully determined, and there are at least three different theories to explain its microscopic appearance. The Reticular Theory. — One school of scientists describes protoplasm as an extremely minute network of fibers forming a sort of sponge, in the meshes of which there is found a moving liquid; Fig. II A . This is the so-called reticular or fibrillar theory of protoplasmic structure. of protoplasm as due to a mass of minute bubbles, like soapsuds on a small scale; and insists that what appear to be fibers are only the delicate lines separating the protoplasmic structure. The Granular Theory. — Still a third theory suggests that the protoplasm consists of an indefinite number of minute, living, moving granules, arranged in lines resembling fibers or in various other figures. This is the granular theory of protoplasmic structure. Between these theories the scientists have not reached any conclusion, although the first two have been more generally accepted than the last. It is quite possible, and even probable, that all of the theories may have a certain amount of truth in them, and that protoplasm does not in all cases have the same structure. It is certain, however, that protoplasm always shows a structure and is not a homogeneous body. In most cases 3. Minute bodies (microsomata) (Gr. micros = small -fsoma = body) scattered along the branches of the network, regularly or irregularly, and frequently moving to and fro in the cell. Activity of Protoplasm. — If living protoplasm be studied under the microscope, it will frequently show a type of motion called streaming. This is due to minute granules constantly circulating in a more or less definite or indefinite fashion within the cell. Whether all protoplasm will show such motion we do not know, but apparently whenever this substance is actually alive this motion is present. Possibly this may not be true of protoplasm that is known as dormant, but it is almost certainly true of all active cells. THE NUCLEUS Lying within the cell substance there is a smaller body, usually of an approximately spherical shape, called the nucleus (Lat. nucleus = nut); Fig. 9n. This is a structure of extreme complexity. It is, as a rule, bounded by a delicate nuclear membrane nm, which holds the contents and separates them from the surrounding cell substance. Within this membrane may be found a jelly-like mass, very similar to, if not identical with, the cell substance outside, and also included under the term protoplasm. To distinguish these two parts of the protoplasm, that inside of the nucleus is called karyoplasm (Gr. karyon = nut + plasma = substance) or nucleoplasm, while that outside is called cytoplasm (Gr. cytos = cell + plasma) ; Fig. 9 ky and cy. In addition to karyoplasm, however, there are other distinct parts in the nucleus. Delicate fibers run through it called linin fibers (Fig. 90, and a small rounded body known as the nucle- unknown. The most remarkable substance in the nucleus is a material known as chromatin (Gr. chroma = color); Fig. 9 ch. It has received the name chromatin from the fact that it has a special affinity for certain staining reagents, the chromatin material in the nucleus being the first thing to absorb the color and become stained. By special methods the chromatin may be stained and the rest of the nucleus left unstained. The latter is sometimes called achromatin (a = without + chroma = color). By this special process of staining it is possible to show the chromatin in prepared specimens, although in the living cell the chromatin is so transparent as to be practically invisible. Chromatin occurs in a great variety of forms in different nuclei. Some of these are shown in Figure 12. It is sometimes diffused irregu- larly through the nucleus; it may be in the form of stars, or a long coiled thread, or it may appear as isolated threads, or as threads interlaced, etc. Whatever its form, it always has the power of absorbing coloring material and is probably always of the same general, chemical composition. The nucleus controls the cell activities, and the chromatin forms the most important part of the nucleus. THE CENTROSOME Near the nucleus in many cells may be found a minute body (Fig. 9cr) known as the centrosome (Gr. centron = center + Gr. soma = body), which is usually present in the cells of animals, where it seems to have an important function in controlling the multiplication of the cell. The centrosome is usually lacking in the cells of the higher plants. Frequently two centrosomes are found near together, and sometimes they are surrounded by a clear area, which is designated as the centrosphere. At one time the centrosome was considered of great importance in the life of the cell, from its prominent role in cell division; but since it has been discovered that some cells have none, while others have several, its significance as an essential element in cellular structure has been doubted. THE CELL WALL One of the functions of the cell substance in many cells is to secrete around the cell a material of harder consistency than the protoplasm, the cell wall. Some cells have no cell wall; for example, the animal shown in Figure 13 is a cell devoid of a cell wall; and in many other animal cells the wall is either very slight or entirely lacking. From this, it is evident that the cell wall cannot be regarded as an essential part of the cell. In nearly all vegetable tissues, the living protoplasm secretes a membrane of greater or less consistency, and the same is also true of many animal cells. The cell wall may be made of a variety of different materials, In plants it is sometimes of wood, the midst of a great ma-ss of secreted wall substance. This is especially true in the case of the cartilage, as shown in Figure 4. The shape of a cell is usually determined by the shape of its cell wall. Figure 14 shows a number of cells and gives an idea of the various shapes ihe cell wall may assume. \\| Since the cell wall is lifeless and has only the function of support, the cell contents alone being alive, it follows that any organism may contain both living and lifeless material. Among plants the lifeless material may far surpass the living in bulk. In a tree, for example, most of the trunk, roots, and branches are made of the dead walls of cells which were formerly filled with living protoplasm. In a large tree only a thin layer of cells directly under the bark, the cells found in the leaves, buds, and some cells in the roots, are actually alive. In animals a much larger proportion of the body cells are alive, the bulk of the muscles beirg living protoplasm ; but the skin, hair, cartilage, and bone contain in a marked degree lifeless cell walls from which the living matter is either wholly withdrawn, as in the hair, or remains only in a relatively small amount, as in bone and cartilage. Other Substances in a Cell.— Cells may contain other bodies than those already described, which cannot be regarded, however, as essential to cell life, since they are not characteristic of all cellular structure. Some of these are called plastids (Fig. 9 p) , and seem to grow and divide and to be handed on from one cell generation to the next. Examples of such plastids are the chlorophyll bodies in plant cells, or vacuoles in some animals. Other bodies included in cells are purely passive bodies which seem to be functionless, inert, excreted substances, not growing and not handed down from generation to generation. CELL FUNCTIONS The cell with its protoplasm and nucleus contains all of the parts that are necessary for life, and, so far as we know, nothing simpler than a cell is capable of carrying on all the functions of life. If this be true, we are justified in saying that the ideal cell we have been describing is the simplest bit of structural machinery that can manifest all the functions of life. All living organisms, animals and plants alike, are either single cells (unicellular) or complexes of cells (multicellular), and the life of the organism as a whole is thus the combined life of its individual cells. Definition of a Cell. — To sum up, then, we may say: A cell is a combination of a bit of protoplasm (cytoplasm) with a nucleus, and it is the simplest structure known to show the phenomena of life. present. While these periods are not sharply marked off from each other, they do represent different epochs in the development of the conception of the nature of the cell. The Formulation of the Cell Theory, 1839. — It was not definitely proved until about 1839 that the tissues of animals and plants were composed of cells, although cells were first described in 1665 by Robert Hooke. A microscopic study of a piece of cork showed him that it was made up of large numbers of minute compartments which reminded him of the cells of a monastery. Hence he gave them the name of cells, which they still bear. Miscellaneous observations followed at intervals in the next two centuries. In 1833 Brown described the nucleus as a constant part of the cell. In the years 1838 and 1839 two Germans, Schwann and Schleiden, one studying animals and the other, plants, advanced the theory that the tissues of all animals and plants were made up of these independent units, to which they still gave the name of cells. These observations formulated the so-called cell doctrine. The Original Conception of the Cell. — It was first supposed that the cell wall was the most essential part of the cell in controlling the processes of life and separating die contents of the cell from the surrounding medium. This conception did not last long, for it was soon seen that there were many cells that did not have cell walls. In these early days the existence of a nucleus was not realized as of much significance. crystals form in a supersaturated solution of sugar, the cytoblastema being described as a complex, supersaturated solution formed by the living body. This theory did not last many years, however, because it was shown that cells arise only from other cells. Even as early as 1846, Schultze and others proved that cells have no other origin except from previously existing cells. Starting with an egg, which is easily demonstrated to be a single cell (Fig. 15 A), and then carefully studying its development, it can be shown that its growth is by the method of repeated division and sub-division (Fig. 15 £, C, D, E, F) until the singlecelled egg gradually becomes the many-celled adult. Although the cells become very numerous, they all arise by the process of division from the original egg cell. For many years, however, it was considered possible for a cell to arise in some other way than by division of the original egg cell; and even as late as 1880 discussions took place as to whether "free cell origin" was possible. By this ghowing how & single.celled egg term was meant the origin of cells (A),bydiv»onCBtoO),grow»iiito we are now certain that cells never arise except from the division of earlier cells, and that all the cells of an adult animal body, though there may be millions, have arisen by the process of division from the original egg, which was in itself the single cell from which the life of the The Discovery of Protoplasm. — In 1839 Purkinje first recognized under the name "sarcode" the contents of the animal cell; H. Von Mohl in 1846 applied the term protoplasm (Gr. protos = first + plasma = substance or form) to the viscid, granular substance found in plant cells. Cohn in 1850 claimed not only the identity of animal and plant protoplasm but contended that it was the seat of vitality, — the basis of life. In 1861 Max Schultze established Cohn's theory and extended the meaning of the word protoplasm to include all living matter. This was a new conception and at once placed the doctrine of biology upon a new basis.- If it could be proved that the cell substance, which is the living material in all cells, is always alike, it would show that life could be reduced to one fundamental basis. The name protoplasm had been given to the living substance in the animal embryo and then to a similar material in the cells of plants; but it was Schultze who identified it with the living material of animal cells and extended the name to apply to this universal life substance. With this new conception, he defined a cell as a mass of protoplasm surrounding a nucleus, and thus placed the keystone in the arch of the protoplasmic theories. Schultze's conception of protoplasm was somewhat expanded and made more significant by Professor Huxley in 1866. Huxley, giving to it the name "physical basis of life," drew farreaching conclusions as to the significance of the phenomenon that we call life, based upon this universal physical substance. He argued that the properties of life are simply characters of this protoplasmic substance, just as other properties are characteristic of water; and that life represents no distinct entity, but is simply a name applied to the combined properties of this remarkable chemical compound, protoplasm. This started a long search for a chemical explanation of life phenomena. In accordance with this idea, life was looked upon as merely representing a special manifestation of chemical and physical forces; it was argued that there was no more reason to speak of vitality as a special property possessed by living things, than to speak of aquosity as a special property possessed by the chemical compound water. The Mechanical Theory of Life. — Based upon this conception arose a large number of interesting speculations, and the discussions during the next twenty-five years resulted in a development of the mechanical theory of life. It was argued that, if life is merely a name given to the properties of protoplasm, and if chemists could manufacture the chemical substance protoplasm, they could thus create life, i.e., living protoplasm. Chemistry was at this time advancing with prodigious strides, and chemists were making more and more complex substances, and new compounds which had hitherto been considered beyond their reach. Many of the substances, which had previously been supposed to be produced only by living processes, were, one by one, manufactured synthetically in the chemist's laboratory. From this the further assumption and confident prediction was made that the time would come when it would be possible to manufacture a bit of protoplasm by purely chemical means; and then it would follow, if the mechanical theory of life were correct, that this bit of protoplasm would necessarily be alive and scientists would thus be able to manufacture a living thing. This was the essence of the mechanical theory of life which largely dominated discussion of biology for a quarter of a century. General Properties of Protoplasm. — With this idea of protoplasm as the basis of life, a large amount of study was given to this interesting material. Since it is alive, it has of course all the properties of life. If we look upon protoplasm as the physical basis of life, we may in one sense say that its properties are as varied as are the properties of living things, since the characteristics of living things are based upon the charac- teristics ot their protoplasm. If the characters of mankind are dependent upon the properties of its protoplasm, it follows that the protoplasm that makes up the cells in man must differ as much from the protoplasm that makes up the cells of a plant as mankind differs from the plant. There will be, then, is many varieties of protoplasm as there are varieties of living beings in the world. But apart from these detailed characters, we find that the substance protoplasm, using this term now to refer to the general life substance of the cell, has a few characteristics that are present in all forms of protoplasm whether animal or plant. In other words, all forms of living matter possess certain general properties, which are frequently spoken of as the general characters of protoplasm. They are as follows : — I. Chemistry of Protoplasm. — Various attempts were made in earlier years to determine the chemical composition of protoplasm. The chemical elements out of which it is made are easily found to be carbon, hydrogen, oxygen, nitrogen, sulphur, and some other substances in small quantities. For a time it was supposed to be a definite chemical substance with a definite formula, and attempts were even made to give the number of atoms present in a molecule of protoplasm We now know that such attempts were necessarily futile. Protoplasm is not a chemical compound but a mixture of a variety of different compounds. The fibrillar network, the liquids, the microsomata, and the chromatin are certainly all different from each other, and it is manifestly impossible to speak of the chemical composition of protoplasm as a whole. We can safely say that protoplasm contains proteids, but beyond this, little of significance has yet been determined. Since it is in a very unstable condition, constantly undergoing changes, its chemical composition cannot be constant. Moreover, the chemical nature of living protoplasm is doubtless different from the same material when dead, and since any chemical tests are sure to result in its death, it is impossible to determine the composition of the material when alive. 2. Irritability. — All forms of living protoplasm have the power of reacting when stimulated. This phenomenon is called irritability and is produced by the action of a large variety of external ibrces upon the protoplasm itself. Any external force which serves to produce a reaction in the protoplasm is spoken of as a stimulus. Almost any kind of stimulus has the power of affecting protoplasm: mechanical, thermal, electrical, and chemical. Stimuli all "have their effect upon protoplasm and all produce certain reactions within it. Protoplasm is, in short, irritable to almost any external stimulus. While the different forms of protoplasm show different degrees of irritability to various stimuli, they have certain general reactions in common. The activity of protoplasm increases directly with the heat to a certain point, and then decreases, and finally ceases altogether if the temperature continues to rise. Although some forms of protoplasm are much more irritable to mechanical stimuli than others, nevertheless, all types of protoplasm are influenced by external, mechanical force. Various other factors,— light, chemism, gravity, etc.,' — mentioned upon pages 57, 58, stimulate protoplasm. Various organic, internal changes stimulate it as well. If the protoplasm is improperly nourished it produces a condition that is in general known as hunger, and this excites the irritability of protoplasm. The same thing is true if there is insufficient water within the protoplasm, producing an irritation called thirst. Protoplasm is also destroyed by various chemicals called poisons, like chloroform, corrosive sublimate, etc. 3. Conductility. — An irritation produced in any one part of a bit of protoplasm is rapidly conducted throughout the whole mass, a phenomenon known as conductility. In an ordinary cell, this phenomenon of conductility does not have very much meaning, because the bit of protoplasm is too small; but some cells possess long protoplasmic fibers extending from their bodies; and then this function of conducting impulses from one end of the protoplasm to the other becomes of considerable importance. For instance, a nerve fiber, even in the higher animals, consists of a long bit of protoplasm extending from the cell body; see page 169. The phenomenon of conductility in this case is of great significance because it may carry an impulse from the outer end of these nerves (the periphery) to the cell body in the brain, or it may carry one that started within the body rapidly outward to the periphery. This phenomenon of conductility, therefore, forms the primary function of the nerves. It is this function that makes it possible for a stimulus applied to the outer part of the animal to be carried rapidly over the animal so as to produce a response in other parts of the body. 4. Assimilation. — All protoplasm has the property of taking in food material, changing its chemical nature and converting it into new protoplasm by assimilation; a process which may result in growth. This process is probably always a constructive one; i. e., it builds more complicated materials out of simpler ones. Different kinds of protoplasm have this power developed to a widely different extent. Some cells assimilate and grow with great rapidity, with the result that they multiply rapidly; other cells seem to have lost much of this power of assimilation in their adult life, and are able only to replace the worn-out parts of their own structure. In the higher animals, for example, the cells are all capable of rapid assimilation, growth, and reproduction in youth, but many of them nearly or wholly lose this power after the animal has reached adult life. The nerve cells in the brain and spinal cord, for example, seem largely to have lost this property of assimilation, for they are unable to grow after they have once reached the adult form, although able to repair their own wastes. Later in life, nearly all the cells in the body lose this power, a condition characteristic of old age. Speaking generally, this power of assimilation and growth is most active at the very beginning of the life of a cell; it continues for a period with a gradually declining vigor and finally comes to an end, starting vigorously again as the result of the process of reproduction. 5. Reproduction. — Reproduction is the direct result of assimilation; for assimilation produces growth, and growth in the end results in division. All forms of reproduction take the form of division. The four properties, irritability, conductility, assimilation, and reproduction, have been described as belonging to protoplasm; and the mechanical theory of life has centered around this conception. But in a sense it is misleading to call them properties of protoplasm, unless in the term protoplasm we include all of the contents of a cell, the nucleus as well as the cell substance. A living cell shows these general properties; but the living cell consists of protoplasm and nucleus, both of which are necessary in order that all the functions mentioned should be shown. The material frequently called protoplasm, i. e., the substance outside of the nucleus, does not show all these functions. We ask, therefore : What are the functions of the nucleus and protoplasm as distinct from each other? To draw a sharp line between them is not possible at present. In the early study of the cell the nucleus was looked upon as an unimportant part, and in all of the early discussions its significance was generally neglected. From about 1880 the modern microscope and modern methods began to be directed towards the nucleus, and a series of marvelous and unexpected results were obtained, leading to the recognition of the nucleus as perhaps the most important part of the cell, and as possessing a structure of wonderful complexity and marvelous properties. The structure of the nucleus has already been outlined and may be seen in Figure 12. These figures are enough to disprove any idea that either cytoplasm or nucleoplasm can be considered a definite chemical substance. They indicate clearly that in the simplest life unit, we are not dealing with a homogeneous compound but with a complex structure and a mechanism of delicate adjust- A nucleus is necessary to the complete life of a cell. Among the unicellular animals are some cells large enough for experimenters to cut to pieces in order to study the different functions of the fragments. These experiments are very difficult and delicate, but they have been carried on by a number of investigators independently, who have demonstrated the following facts: If a cell is cut to pieces in such a way that each piece contains a fragment of the nucleus, ^each fragment is capable of carrying on independently all life functions. Each can feed, grow, and COMPLETE ANIMALS multiply, and seems to be lacking in none of the essential functions of life; Figs. 16 and 17. If, however, the animal is cut to pieces in such a way that some of the fragments contain pieces of the nucleus, while others contain none, the frag- ments act in totally different ways. Those that contain nuclear material are able to redevelop lost parts, to carry on their life processes and to grow and multiply as usual; the fragments that contain none of the nucleus, although they can move around and apparently maintain life for a while, are unable to feed, or at least to assimilate their food ; they are unable to grow and unable to multiply; Fig. 18. They have thus lost the most essential features of life, since they have lost the constructive power by which protoplasm can assimilate and grow. These experiments, repeated many times over, show that the complete life of a cell is impossible without the presence of a certain amount of nuclear material, but if nuclear matter is present, the cell can carry on its complete life, even though the nucleus is itself cut into many pieces. Such experiments, of course, demonstrate very conclusively that life functions cannot be carried on by protoplasm alone, but only by protoplasm in combination with nuclear substance. The Nucleus in Heredity. — It is well to anticipate here one further fact that demonstrates the great significance of the nucleus and chromatin. As we shall notice on a later page, nearly all animals and plants show a form of reproduction in which cells from two different individuals, male and female, combine. This is known as sexual reproduction or fertilization. When this union takes place, it is not the whole cells that combine but only the nuclei; or still more accurately, it is the chromatin material of the cells that combines rather than the whole nuclei. The reconstructed cell contains chromatin ma- terial from both of the cells which entered into the combination. Now inasmuch as, after this combination, the offspring which arises from the cell thus formed by the union of the two parental cells inherits characteristics from both parents, and inasmuch as the only part of the original sex cells which enters into the union is the chromatin, it follows that the chromatin material itself is the bearer of heredity, and that in these little chromatin threads, minute as they are, there must be a complexity sufficient to contain the features of inheritance that are handed on from generation to generation. These facts give at least some idea of the separate properties of cell substance and nucleus. The cell substance by itself has the functions of irritability and conductility ; but not of assimilation, growth, or reproduction. These latter functions can be carried on only when a nucleus is present. Indeed, if we ask to-day just what is meant by protoplasm, the question becomes very difficult to answer. We can no longer look upon it as simply the jelly-like substance within the cell in which the nucleus lies embedded, for it is evident that although this substance has the properties of irritability and conductility, it does not have the properties of assimilation and growth. If we wish still to call protoplasm the physical basis of life, we must extend the term to include the nucleus as well as the substance outside of the nucleus, since without the nucleus, protoplasm is unable to carry on life processes. If, however, we include, in this term protoplasm, the centrosome, and the nucleus with its chromosomes, it becomes evident that protoplasm has quite lost its original significance. It is no longer the homogeneous substance, and can no longer be looked upon as a chemical compound, but is on the other hand a mechanism with a number of distinct, though closely correlated parts. The explanation of its activities can no longer be regarded as a chemical problem simply, but must be in a measure a mechanical problem as well. This conception totally alters the significance of the phrase "the physical basis of life" and puts the problem of the mechanical theory upon a decidedly new footing. To-day biologists are gradually giving up the use of the term protoplasm as confusing and misleading, replacing it by more definite terms which refer directly to the different parts of the cell. So now we find coming into general use the terms cytoplasm and karyoplasm (see page 32) to cover what was formerly called protoplasm. Both cytoplasm and karyoplasm are necessary and must act together in order to show the general characters of life. That reproduction may occur, the chromatin, and perhaps the centrosome also, are requisite. The mechanical theory is no longer tenable in the form in which it was originally advocated and discussed. That position has been necessarily abandoned since the studies of more recent years have demonstrated that protoplasm is not a homogeneous substance and cannot be regarded simply as a chemical compound. It is, on the contrary, a very complex mixture of substances, forming a complicated machine in which the parts are most intricately interrelated and adjusted. While chemical forces may be regarded as sufficient to manufacture almost anything in the way of chemical compounds, they are not adapted to the manufacture of such a mechanism as living protoplasm has been proved to be. This change in the attitude of biologists has been brought about mainly through the minute study of the nucleus and the constantly increasing recognition of its great importance in the life of the cell. Are There Life Units Simpler Than Cells?— As we have learned, the cell is by no means a simple structure but a complicated mechanism. The question inevitably arises whether the cell is the simplest structure that can manifest life or whether it may not be analyzed into simpler units. This is one of the puzzling and unsettled problems of biology. Certainly some of the most minute living things (certain bacteria) seem to possess a body in which there is no definite nucleus, but in which the chromatin matter is more or less scattered without being aggregated into a nuclear mass, and this has led to the suggestion that perhaps the simplest life unit may be an excessively minute granule of chromatin with delicate fibrils extending from it, and that a cell is a combination of many of these minute elements. Other facts disclosed by the minute study of many animal cells, with very high magnifying powers and under special conditions, have pointed to a similar conclusion. As a result there has been advanced recently a theory that the cell is far from the simplest unit of life, and that it can be analyzed into a great number of minute elements called "chromidial units," each made of a granule of chromatin with fibers of linin radiating from it. According to this theory the whole cell is made of a network of linin fibers with granules at the nodes, each granule thus representing a life unit far simpler than a cell. This has been called the "protomitomic network." This protomitomic theory is as yet only a matter of speculation, and its chief interest to-day is in the fact that it suggests that the cell may be far from the simplest unit manifesting life. Whether this new suggestion be established or not, it seems certain that the manifestation of life requires the presence of three elements: (1) chromatin material, (2) delicate fibrils radiating from it, and (3) of a liquid material in which the other parts are embedded. As yet we know of nothing simpler than a combination of these three that is able to manifest all the properties of life. LABORATORY WORK ON CELLS A satisfactory study of cells requires familiarity with the microscope and considerable skill in microscopic methods. Little can be wisely undertaken by elementary students, beyond the examination of prepared specimens, properly stained, which should be furnished by the instructor. Drawings should be made by the student in all cases. The cellular structure of animal tissues may be studied in the following preparations: — cells having nucleii. Cartilage. — Mounted sections of cartilage will show nearly rounded cells, embedded in a very thick mass of cell wall, the thickened cell wall forming the intercellular substance, or basis of the cartilage. shape. In these sections the cell walls only appear. A section of a growing root tip. Longitudinal sections of Podophyllum, which are particularly good, should be furnished. These sections, if properly stained, will show the cell contents as well as the cell walls. The protoplasm and nucleus may be seen and drawn. In particularly good specimens, stained with iron haematoxylin, the chromatin in the nucleus may be seen with an oil immersion, 1/12 inch objective. For the study of protoplasm Spirogyra is a favorable object. The student, after studying the normal specimen, should treat it with a little glycerine, which will cause the protoplasm to shrink away from the cell wall so that it can be seen. of Tradescantia. Ci'iary motion may be studied best by cutting off a bit of the edge of the gill of a fresh-water clam, and examining with a high-power objective. It may also be shown by scraping the roof of a frog's mouth with a scalpel and mounting the scrapings in a little normal fluid. IN order to become familiar with the general properties of living things, we will study the structure and functions of some of the simplest organisms. Those that are studied in this chapter are all microscopic, and belong to the group of unicellular organisms sometimes called animalculae. Size and Shape. — The Amoeba (Gr. amoibos — changing) is a microscopic animal found both in fresh and salt water. The most common species averages about 1/100 of an inch in diameter, but the size varies in different species. With perseverance they may be discovered in nearly all bodies of water where there is mud and slime. One of the best methods of procuring them for study is to collect water plants (Ceratophyllum) or even pondlily leaves, and to place them in dishes of water until they decay. After a couple of weeks or so a brown scum appears and an examination of this scum usually shows Amoebce in abundance. Under the microscope the Amoeba is seen to be a single cell without definite form, the same animal undergoing constant changes in outline. Lobes are thrust out first in one direction and then in another (Fig. 19), and as soon as one lobe is protruded the contents of the body begin to flow into it and may continue to flow until the whole body substance has passed into the lobe, other lobes being formed in the meantime. By a continual protrusion of such lobes and the flowing of the body into them, the Amoeba has a slow motion. These lobes are thus used as organs of locomotion and are called pseudopodia (Gr. pseudos = false -f pous = foot). There has been considerable speculation as to the forces which produce pseudopodia, and various attempts have been made to explain them by purely physical forces. It has been suggested that they are due to the adhesion of the sticky substance of which the animal is made, to the object upon which it rests. Another suggestion is, that the pseudopodia are due to changes in surface tension produced by the currents in the body as they flow to and fro. Still another theory seeks to explain the formation of pseudopodia by stereotropism (Gr. stereos = a solid + trope =a turning), the attraction of a solid body for living tissue, which is supposed to cause the body of the animal to flow from one point to another of the surface upon which it rests. There is also the theory of chemical attraction. However, the production of these pseudopodia cannot be satisfactorily explained by any of these means; enough careful study of the Amceba in motion has been made to show that the pseudopodia may be thrust out in any direction, either horizontally or vertically; and when thrust out vertically they may be bent forward until they come in contact with the surface on which the animal rests and then become attached. Their motion has to be explained by an active power of the living substance. This power on the part of the living substance has been called contractility, and it cannot be explained as due to any physical force like surface tension, adhesion, or chemical attraction, but is due rather to active contraction which must be regarded as a general function of the protoplasm of a living cell. Structure. — The body of Amoeba is made up of a transparent mass of protoplasm, in which there may be distinguished an outer clearer layer, called ectoplasm (Gr. edos = outside + plasma), and an inner, more granular mass called endoplasm (Gr. endon = within + plasma). No very definite line can be drawn between them, the difference being due chiefly to the presence of granules in the interior and their absence from the outer layer. These granules are in motion, slowly circulating within the animal, and thus showing the existence of currents in the protoplasm. When the pseudopodia are protruded, the first change is the protrusion of a lobe of the ectoplasm; after which the granules can be seen flowing into the lobe until finally the whole of the endoplasm may flow into the extruded lobe. Many of these granules represent food in various stages of digestion, some of them being digested food and others undigested refuse. Among them may be found drops of clear liquid with a bit of digested food in their center. Besides these granules, two more definite bodies are always found. One (Fig. 19 ri), the nucleus, is a small rounded body near the center of the animal, but not fixed in position, since it moves with the protoplasmic current. This is one of the structural parts of the animal, not, like most of the granules, merely extraneous material, and is always present in the living animal. The other body commonly found is the contractile vacuole (Lat. vacuus = empty) (Fig. 19 cv). This is a clear, pulsating drop, at one moment appearing as a good-sized sphere, and the next contracting and disappearing, to reappear again. It is thought that when it contracts, its contents, which are liquid, are forced out of the Amoeba's body through minute openings that appear in its sides. These pulsations, which are fairly regular, plainly indicate the performance of some important function. Assimilation and Growth. — When the Amceba comes in contact with a small plant or other bit of food, the pseudopodia flow around and over it so that the food is taken bodily inside the animal. The food may be taken in at any point on the surface of the Amoeba's body, though more frequently it is engulfed by the anterior pseudopodia. As shown in Fig. 19 B, particles of food longer than the whole animal may be ingested. After a time the bit of food thus ingested begins to show signs of disintegration. It loses its sharp outline and becomes slowly softened and dissolved. This change is produced by the action of certain fluids which the animal secretes, and is a process of digestion. The nutritious portions become in time absorbed by the protoplasm and converted into new Amoeba substance; the last process being assimilation. The refuse finds its way eventually to the surface of the animal, a temporary openingappears and the Amoeba crawls away, leaving the refuse behind it; Fig. 19 ex. Any part of the body may thus serve for the ingestion of food or the ejection of refuse, although the food is commonly taken in at the anterior end, and the refuse ejected from the posterior end. Respiration. — Amoeba is not only carrying on a process of assimilation, by which new substances are built up, but is also at the same time carrying on a process of disintegration, by which the complex substances are broken down. This latter is based upon oxidation or union with oxygen. As the result of oxidation there is always formed carbon dioxid gas (C02) as a waste product, which must be eliminated. The Amoeba is, therefore, obliged to absorb oxygen gas from some source and to eliminate carbon dioxid gas. This process of absorbing and eliminating gases is known as respiration. In the Amoeba there appear to be no special respiratory organs, although possibly the contractile vacuole performs this function. But the body of the animal is so small that special respiratory organs are unnecessary, since gas is readily absorbed directly through the surface of the body from the water in which the animal lives, and carbon dioxid is as readily eliminated into the water. A respiratory function is thus developed, but no distinct respiratory organs. The elimination of carbon dioxid gas, since it is the getting rid of a waste product of metabolism, is not only part of the function of respiration, but belongs also to the function of excretion. Excretion. — As the result of this disintegration there arise in the Amoeba disintegration products which are waste materials and must be eliminated from the body. These products are primarily three : carbon dioxid gas, water, and a product containing nitrogen, and related to urea which is excreted by the kidneys of higher animals. The function of getting rid of these waste products is called excretion. In Amoeba the gas and the water are • excreted directly into the surrounding water, either through the general surface of the body or by the contractile vacuole. The urea is probably eliminated by the contractile vacuole. It should be clearly recognized that the elimination of the undigested portions of the food, mentioned on page 55, is not excretion. These undigested parts of the food, though sometimes called "excreta," have never become part of the Amoeba's body and are simply foreign bodies that have been rejected as useless. True excretion, on the other hand, always refers to the elimination of the products of dissimilation. water, and some forms of protoplasm much more, certain organisms containing over 95%. When dormant, protoplasm may remain alive with a far smaller percentage, dried seeds containing as little as 8%. Some animals also may be dried (dessicated) and still retain their vitality for a long time. This is true of many of the microscopic, unicellular animals and also of some of the higher types (e. g., Hydatina; see Fig. 116). In all such cases life activities are suspended but will be resumed when the animal imbibes water. Irritability. — The Amoeba has no sense organs nor does it have any nervous system. It is difficult or impossible to determine positively whether it has any conscious sensations, but it certainly has the power of reacting when stimulated, thus showing that it possesses irritability. Reaction to contact (Thigmotropism) (Gr. thigma = touch + trope = a turning). — If the moving Amoeba is touched by a solid object, the part touched draws away from the object, new pseudopodia being thrust' out in another direction. If, however, the object be a particle of food, the animal is differently affected and the pseudopodia flow around it so as to engulf it. Reaction to chemicals (Chemotropism) (Gr. chemesa = chemistry + trope ) . — If certain chemicals are brought in contact with the Amoeba, it moves off in some other direction. Sugar, lactic acid, sodium chloride, and many other substances have this effect. Reaction to heat (Thermotropism) (Gr. thermos = heat -{-trope). —The activities of the Amoeba are directly dependent upon temperature. At a temperature of freezing, no activities are manifest. If the temperature is raised the activities begin and become more active with the increase in temperature up to a certain point, about 85° F. If warmed still more, they become less active, and when heated to about 90° F. the activities cease entirely. At about 105° F. the protoplasm is coagulated and the animal killed. If a warm or hot object is brought near an active Amosba the animal moves away from it. Reaction to light (Phototropism) (Gr. photos - light -f- trope).— If a strong light is directed upon an Amoeba from one side, it will move away from the light. A strong, white light may cause the animal to stop moving. Reaction to electricity (Electropism) (Eng. electro -f- Gr. trope).— If an electric current is passed through an Amoeba, it contracts on the side of the positive pole of the current and moves toward the negative pole. In all these cases the Amceba reacts to a stimulus. But there are other things which are irritable and react to a stimulus in a purely mechanical fashion. Gunpowder is also irritable, since it will react to heat with an explosion. A locomotive is irritable, since it will react to a touch upon its throttle valve. The Amoeba certainly reacts in a more complex and more varied manner, but the question inevitably arises whether the action may not be simply that of a bit of machinery responding to its appropriate stimulus. There is no definite answer to this question that can yet be given. Reproduction. — As the Amoeba by assimilation converts its food into new protoplasm, it inevitably increases in size. If this went on without interruption there would be no limit to the size of the animal. But after growing for a time, a constriction appears in the middle of the body which deepens until it finally divides the animal into two parts; Fig. 19 C. Each -of the resulting parts is like the other and each like the original, except in size. It is the nucleus that seems to take the lead in this process of division, which is one of great complexity. This will be described in the next chapter, for it goes through the complicated series of changes known as karyokinesis (Gr. karyon = nucleus + kinesis = movement) described on page 85. As a result of this division there arise two animals, evidently alike, each of which now moves away and lives an independent life. This method of reproduction, by which the animal divides into two practically equal parts, is called fission. Amoeba. This is very unusual, however, and has been seen by only one observer (Sheel). In this method the animal draws in its pseudopodia, assumes a spherical form and secretes around itself a thin shell called a cyst. Inside this cyst the nucleus divides into many parts, some five or six hundred nuclei thus finally arising by division. After this the rest of the substance divides so that each nucleus finally becomes surrounded by a little protoplasm, the contents of the cyst coming thus to consist of some hundreds of little bodies, each with its nucleus. Eventually the cyst bursts and the little cells escape, each being now a minute Amoeba, which has only to grow, to be like the original. This method of reproduction is also evidently a division. It is a type of division called spore formation. The whole process takes two and a half to three months, and the conditions which bring it about are unknown. A, Difflugia, an Ama>ba-\ike animal with a shell made of pebbles; B and C, Podophrya and Acineta, animals with stiff protruding tentacles of protoplasm; /, food; D, Arcella, an Amoeba-like animal with a secreted shell. PARAMBCIUM Paramedum can usually be found in the same localities as Amoeba and can easily be obtained by allowing lily pads to decay in a dish of water. A quantity of living organisms soon Like the Amoeba, it is a single cell, and like the Amoeba also, it is made up of protoplasm consisting of an outer, somewhat clear ectoplasm and an inner, more granular endoplasm. The Paramedum has a body which, although flexible, is somewhat rigid and elastic, and, unlike the Amoeba, always tends to preserve a definite form. It is elongated, somewhat blunter at one end than the other, and in its motion carries the blunt end forward. The protoplasm has no power of protruding pseudopodia, and the animal therefore does not change its shape like the Amoeba. Upon one side, posterior to the middle of the body, there is a groove extending obliquely backward. This is the oral groove (og), at the bottom of which there is an opening leading to a short tube which extends through the ectoplasm into the endoplasm. The opening is the mouth, and the tube is known as the oesophagus or gullet; oe. Locomotion. — The whole of the outer surface of the animal is covered with numerous, fine, threadlike projections and forth. Ordinarily in life, they are directed somewhat backwards, and as a result of this position, when they beat back and forth they cause the propulsion of the animal forward through the water with a uniform motion. When the cilia are directed forward, their beating back and forth will cause the animal to move backward. At the same time with their back-and-forth motion they beat slightty to one side, causing the animal to rotate slowly on its long axis as it moves either forward or backward. Exactly how these cilia are able to move is not known, but a power of automatic vibration is always characteristic of these organs. Lining the tube called the oesophagus, leading from the mouth, there are special cilia, longer than the rest and united to form a vibrating membrane known as membranella ; Fig. 21 mb. The function of this mass of fused cilia is to guide the food from the mouth down through the oesophagus into the body cavity. The direction in which the cilia point, and consequently the direction of the motion they produce, are affected by a variety of external conditions, for the Paramecium, like the Amoeba, is irritable and its motions are regulated by the pear to be organs of offense or defense, since they apparently contain a small quantity of poison by which the animal may kill or paralyze its prey or its enemies. On the very outside of the ectoplasm is an extremely thin mem- brane known as the cuticle (cu), through which the cilia protrude. This is ordinarily invisible and can only be seen under special conditions. It is a protective covering which makes the body a little more resistant than it otherwise would be. The endoplasm fills the rest of the body and is very highly granular, containing large numbers of food masses in various stages of digestion. The nucleus is double, showing a large macronucleus* (Fig. 21 win), and near it a small micronucleusf, mic. These two bodies lie close together near the mouth and hold fairly constantly their relative positions in the body of the animal. Two contractile vacuoles (cv) are found in the common species of Paramedum, one at each end. These vacuoles connect with the different parts of the body by a number of minute radiating canals, six or ten in number, which extend in all directions. Certain liquids are, apparently, poured into these canals from the living protoplasm and through them flow into the vacuoles, which increase in size until they reach a certain magnitude and then suddenly contract and discharge their contents to the exterior, probably through minute openings. The contraction of the vacuoles is fairly regular, varying in rapidity with the temperature; the two vacuoles do not contract simultaneously, but alternate with each other. These organs, as in the case of the Amoeba, are probably associated with the function of respiration and excretion. Assimilation and Growth. — The food of the Paramedum consists chiefly of minute bacteria. These are driven into the mouth by the action of the cilia, and by the membranella in the ossophagus, and then guided down the oesophagus to its inner end. Here the bacteria collect in a little drop of water. The oesophagus then contracts and pinches off this little drop containing the bacteria, and thus forms what is called a food vacuole, which enters into the general mass of the endoplasm and follows the movement of the protoplasm around the body. The digestive juices are secreted and gradually digest the bac* Gr. macros = large. f Gr. micros = small. teria, the nutritious portions of which are absorbed by the body and assimilated into new Paramecium substance. The undigested refuse portion is eventually discharged at the posterior end of the body on one side. There is no perrrmnent opening here, but whenever material is to be rejected a temporary opening appears, at the point shown at Fig. 21 ex, and the refuse material is discharged into the water. The process by which food is used, including the absorption of oxygen and the excretion of waste products, as well as the oxidation of the food itself, is essentially identical with that in the Amoeba. As the result of the process, the food material is eventually assimilated into new Paramecium substance, and the animal grows, increasing in size until it is ready for reproduction. Irritability. — Paramecium is totally lacking in sensory organs or in a nervous system, but like the Amceba it reacts to a variety of stimuli. If an injurious stimulus is applied to one side of it, the animal will reverse its cilia and move away from the irritating stimulus. It may move backward or it may turn its forward end in any direction and move off to one side. It is attracted by certain chemical stimuli and repelled by others. It is affected by heat in the same way as the Amoeba. It is slightly affected by an electric current, but is not affected by ordinary light, although the so-called ultra-violet rays have an influence upon it. These various reactions give to Paramecia an appearance of conscious sensation, and it appears as if they had the power of volition to enable them to avoid irritating or unpleasant conditions. But the facts do not necessarily prove this, for it is possible that these reactions are ^only mechanical responses to stimuli, such as might be found in other machinery. The responses, however, are so complicated, and so resemble those of truly conscious animals, that it leads one to suspect that they are actually conscious functions. Reproduction. — The ordinary method of reproduction of the Paramecium is by division (fission) similar to that of Amoeba, although it is more complicated, since the animal is more com- plex in structure. The first step in the process is the elongation and division of the micronucleus into two parts, one of which comes to lie at each end of the animal; Fig. 23. This is followed by a similar elongation and division of the macronucleus. The oesophagus produces a little bud which develops into a new oesophagus, and then this and the old one move apart, so that the latter advances to the front part of the body, and the former lies in the posterior part. A new membranella develops in the oesophagus. Two new contractile vacuoles make their appearance, one just in front of, and 'one just behind, the middle line of the body. Meantime a constriction has been making its appearance, which gradually deepens, cutting the animal into two parts by a cross division. The two halves thus produced separate from each other and swim away to live an independent life. It should be noted that in this reproduction each of the important parts of the animal divides, so that each of the two new individuals has a part of each organ which the original Paramedum possessed. This multiplication by division may go on almost indefinitely if the animal is properly fed and placed under favorable conditions. Ordinarily it will occur about once in twenty-four hours, although the frequency may vary, becoming greater or less with varying conditions of food and temperature. A continuous reproduction of this kind has been followed for over 2500 successive divisions. Whether it can go on indefinitely if the conditions were favorable is not known. It is known, however, that under ordinary conditions this power of reproduction gradually becomes less and less, and finally tends to disappear altogether. It is believed that in nature this disappearance of the power of multiplication and the natural disappearance of the race is prevented by the occurrence of another process known as conjugation (Lat. con = together + jugare = to join). Conjugation. — Two individual Paramecia come together and place themselves side by side, adhering to each other as shown in Fig. 24 a. They do not actually fuse together, but remain attached. The micronucleus in each undergoes a series of changes which results in its dividing into several parts, three of which degenerate and disappear; c. Soon the fourth divides again into two, one of which is slightly larger than the other; d. The smaller part resulting from this last division passes over into the other of the two conjugating individuals, the two animals thus exchanging nuclear matter with each other, as shown by the arrows in d. This small piece of the micronucleus, thus exchanged by each individual, unites in each case with the larger piece of the nucleus remaining in the other individual, and the two combine to form a new nucleus, a fusion nucleus, shown at /. The animals now separate, each of them carrying off in itself a bit of the micronucleus from the other individual. The old macronucleus next disintegrates and disappears (f), and the fusion nucleus divides into eight parts (g) , three of which soon degenerate. One of the five that are left remains as a micronucleus, while the other four become macronuclei, at h. At this stage of the process each Paramedum has one micronucleus and four macronuclei. Next the micronucleus divides into two, and the entire animal divides at once into two separate parts, giving one-half of the micronucleus to each part. This gives two individuals, each with a micronucleus and two macronuclei ; i to k. The process is again repeated, the micronucleus and the whole animal, except the macronuclei, dividing; the result is two more individuals, each containing one micronucleus and one macronucleus; I to m. This brings the animal back to its original condition, and now the ordinary process of fission begins and may go on again indefinitely, both micro- and macro-nuclei dividing with each subsequent cell division. Apparently the purpose of this conjugation is an interchange of the material present in the micronucleus; for it will be seen that after conjugation each of the resulting animals contains nuclear material derived from the micronucleus of the other individual as well as from its own The Life Cycle of Paramecium.— We usually think of the life history of higher animals as marked off in definite life cycles. For example, from the egg of the hen develops the chick, which grows into an adult hen and produces another egg and thus starts the process over again. Such a life cycle we speak of as comprising a single generation, and by the term individual we refer to all the stages of the life of the organism between one point in the cycle and the next similar point. When we attempt to think of the Paramecium in a similar way, we find the case so modified that the terms are somewhat difficult to apply. But still in the Paramecium we can recognize a life cycle somewhat similar to that of other organisms. We shall learn in a later chapter that the life of an animal like a hen begins with a single cell, which, dividing by a process similar to that we have just studied in the Paramecium, gives rise to a large number of cells; see Fig. 15. These, however, remain attached to form the individual which we speak of as the chick, which grows into the hen, and which is thus composed of large numbers of cells. This individual continues a separate existence and eventually a single cell is separated from it to form another egg and to start the process over again, in a new individual. Now if we compare these facts with those just seen in the Paramecium, we shall find that the life cycle of the Paramecium is as follows: Starting in the cycle at the point where two animals separate after conjugation, there begins a series of cell divisions which rapidly increases the number of cells. The cells at once separate from each other, become perfectly independent, swimming apart as quite isolated animals, In this respect the development of the Paramecium differs very markedly from that of the higher animals where the cells remain attached. But the process of division is the same and may continue for a long time. Eventually, however, as we have already seen, this power of division by the simple process of fission becomes exhausted, and the multiplication tends to die out. We can perhaps compare this with the old age of a larger animal, for in old age we find division becoming less and less vigorous, until it finally ceases altogether and the whole generation of cells dies. Among the larger animals, to prevent the extermination of the race, a single cell, an egg, is set aside to start the process over again, thus beginning the new cycle. In the case of the Parametium, after the ordinary reproduction has gone on for a long time it becomes impaired in vigor and seems to be started over again by this process of conjugation. The process of conjugation, therefore, corresponds to reproduction by an egg in one of the larger animals or plants. Hence one life cycle of the Paramedum lasts from one period of conjugation, through all the numerous successive divisions by ordinary fission, until again the conjugation occurs to start a new cycle. One generation, then, consists of all the members that arise between one conjugation and the next; and inasmuch as these animals may multiply almost indefinitely by ordinary division, it is evident that one generation of Parameda may consist of thousands of organisms scattered over a wide territory. It is evident, therefore, that the term individual in the case of the Paramedum cannot have the same significance that it has with the higher animals, since the individual of one of the higher animals would correspond to a combination of all of the different Parameda that arise from the division of any single cell that comes from a process of conjugation, until again it enters into a process of conjugation with another cell. Conjugation thus starts a new generation or a new individual. We do not know how long a time may elapse between two successive conjugations in the case of a Paramedum, nor do we know the conditions which bring about the process. We are even ignorant as to its exact purpose, although it apparently appears to be a process necessary to reinvigorate the race and prevent it from dying out under the ordinary conditions of environment. The process is evidently closely associated with sex reproduction in the higher animals and plants, which is to be taken up in a later chapter. We may even speak of the youth and maturity of a Paramecium; by the term youth meaning the period of rapid cell division that follows conjugation, and by maturity and old age, the period of slower cell division that appears later in the life cycle of the animal. Possibly we may say that the animal eventually dies of old age, by which we would mean that unless conjugation occurs the process of simple division is brought to an end by exhaustion. Whether old age, and therefore conjugation, are necessary in the life history of Paramecium is not yet settled. Experiments have seemed to show that under proper conditions fission may go on almost indefinitely, certainly up to 2500 cell divisions, without the necessity of conjugation, or without seeming to produce any impairment in the power of division. In the normal life of the individual it appears that conjugation is required, however, by some of the conditions of life. Paramedumy therefore, has a definite life cycle, although we do not know its possible length or the conditions which modify it. PLASMODIUM MALARIA As an example of a still more minute animal, we will study the malarial organism, Plasmodium malarice, which lives in the human body. Human blood contains minute circular disks known as red blood corpuscles (see page 192), within which the malarial organisms may be found in persons who are suffering from malaria, or chills and fever. The organism first appears as an extremely minute body (Fig. 25 a), in shape somewhat like the Amoeba, though much smaller. It increases in size as shown by the successive figures a to e. After reaching a size which nearly fills up the red blood corpuscles, it breaks up This is shown in two cycles, the upper one taking place in the human red blood corpuscles, and the lower one in the mosquito. For description ol the individual stages, see text. (From various authors.) into twelve to sixteen small spores, as is shown; / to g. The blood corpuscle now breaks to pieces and the spores are liberated into the liquid blood h. Each may then make its way into a new corpuscle and repeat again the history as already described. Although this animal in its general structure and shape is much like the Amoeba, its habits are totally different. While growing in the red blood corpuscles of the human body, it produces the disease which is known as malaria, chills and fever, or fever and ague. The period when the chills occur corresponds to the time when the blood corpuscles have broken up and the spores are liberated into the blood. The organism may continue to repeat the above history time after time in the blood of the same person, the spores after being liberated entering into new corpuscles, and again repeating their life cycle almost indefinitely and prolonging the disease. There are three different species of the malarial organisms, distinguished by the different length of time required for their life cycles. The most common form takes 48 hours, a second species takes 72 hours, and a third is irregular. By the method of reproduction above described, this organism may multiply inside the blood of one person but is unable to pass to a second individual. Malaria is therefore not communicable as long as this process alone is repeated. But after a time, for some unknown reason, the organisms in the corpuscles assume two different forms shown in Figure 25 at g to i. One of them grows into a large rounded mass, while the other develops several long motile, thread-like bodies, which become detached. No further change occurs unless the patient is now bitten by a certain kind of mosquito (Anopheles). If the blood of a patient is swallowed by this mosquito, the malarial organisms undergo a new series of changes. The thread-like bodies become detached from the mass that produces them, and one of them unites with one of the larger rounded masses, j and k. -This union is regarded as a sex union (see Chapter XII), the larger rounded mass being the female cell (or egg) and the thread-like body the male cell (or sperm) in the sexual union. After the thread-like body penetrates the egg, the nucleus it contains unites with the nucleus of the egg, shown at k and I. After this union the combined mass grows rapidly in size, I to o, and eventually breaks up into an immense number of minute spores, p, greatly in excess of those found at the stage g in human blood. These minute spores lodge in the salivary glands of the mosquito, and are ejected into the blood of the person bitten by the mosquito. Thus a new human individual is inoculated with the spores, which find their way into the blood corpuscles of the new victim and produce the disease. It is not the most common mosquito (Culex) that is concerned in this history, but one that is ordinarily less abundant, a species called Anopheles. From these facts it follows that malaria will not occur in any locality unless this particular mosquito is present; and further, that only the mosquitoes which have previously bitten malarial patients will be able to carry the infection. It will thus be seen that the malarial organism passes through two stages in its life cycle, reproducing itself in each by the production of spores, though the spores are of two different kinds; and that at one stage there is a union of cells of unequal size, which may probably be regarded as a true sex union. All stages of its life are passed within the bodies of other animals, and it is thus wholly parasitic. The three different species of the malarial organism have similar life cycles, though differing slightly in details. The malarial organism passes through two stages, in its life cycle, each in different animals. Such a complicated history, in which there is more than one distinct stage, is known as a metamorphosis (Gr. meta = beyond + morphe = form). Many other animals have a metamorphosis, one of the best-known examples being that of the butterfly, which passes through the well-known states of egg, caterpillar, cocoon, and butterfly. Another example is the frog; see page 286. A metamorphosis is thus found both among higher animals and also among the lowest. CHILOMONAS This is an example of a still more minute organism found very abundantly the world over in water among decaying leaves. From Figure 26 it will be seen that its structure is extremely simple. It has a slightly elongated oval body, with a little depression at one end, at the bottom of which food is taken into the animal, the depression serving as a mouth. There are no internal indications of organs, except a small nucleus. At one end are two filaments called flagella (Lat. flagellum = a whip), which have the power of lashing to and fro. By means of their lashing the Chilomonas is driven through the water. Chilomonas multiples by simply dividing FIG. ' 26. — PANDORINA stagnant water. Pandorina is an animal very similar in its general structure to Chilomonas, except that it is made up of a number of cells grouped together, instead of a single individual body; Fig. 28 A. The method by which this group is formed is simple. The animal starts as a single cell, which divides, but and there arises a group of sixteen cells attached together. They secrete a little mass of jelly around themselves and the flagella projecting through this jelly enable the whole spherical mass to be rotated as a unit. The individual members are somewhat independent of one another, but are attached so as to form one single unit. Such a group is called a colony. breaks to pieces, each cell separating, not only from the colony but from its sister cells. Among the hundreds of cells thus formed some are smaller than others; Fig. 28 C and D. After swimming around for a while one of the smaller and one of the larger cells unite with each other; Fig. 28 E and F. The combined mass then secretes a red shell or cyst about itself and remains dormant for a time, showing no signs of motility, H. Later, however, it resumes its activity and may divide into two or three parts, which then escape from the cyst and swim around for a time as single cells, called swarm spores, /. Eventually each divides into sixteen cells which remain together, forming a new colony like the, original, J A, the animal in its adult condition. B, showing the method of reproduction by simple division, each cell dividing into sixteen parts and the whole colony breaking up into sixteen colonies. C to J shows the successive stages of reproduction accompanied by conjugation ; C, the larger of the uniting cells; D, the smaller ones;E, their conjugation; //, the dormant condition within the cyst. For description, see text. INTERMEDIATE ORGANISMS The organisms thus far described are always classed as animals. We will now study two similar organisms, which stand midway between animals and plants. They are closely related, and yet one of them is not infrequently classed as a plant, while the other is almost always placed with the animals. PGRANEMA Peranema is a microscopic organism found in stagnant fresh water; Fig. 29 A. It is elongated and tapers slightly in front. At the narrower end, which is carried forward in locomotion, there projects a long motile flagellum, by the motion of which the animal is moved through the water. At the base of this flagellum is an opening in the animal, constituting a mouth, leading into a short cesophagal tube. At the bottom of this tube is a peculiar little rod-shaped organ, which apparently serves as a sucking organ for seizing food. Near by is a clear contractile vacuole. The protoplasm of which the body is made is ex- FIG. 29.— Two SINGLEtremely flexible, and the animal, instead CELLED ORGANISMS REof retaining its shape, shows a variety of irregular wavelike contractions passing from end to end. A nucleus is present, and the animal moves either mother respects they are much by the motion of its flagella or by EUQLENA Euglena (Fig. 29 B) greatly resembles Peranema in shape and structure. Like the Peranema, it has an elongated body, tapering, however, at both ends. One end carries a long, motile flagellum by means of which the animal moves through the water. It is made up of flexible protoplasm and goes through a series of contorted motions similar to those seen in Peranema. One or more contractile vacuoles are found near the base of the flagellum. The animal moves about either by its flagellum or by the creeping motion noticed in Peranema. It has also a reddish "eye spot" near the front end. Evidently, these two organisms are very closely related. In two respects, however, there is a striking difference, which has led to the classification of the Euglena by some biologists among the plants instead of among the animals. The Euglena probably possesses no true mouth and does not take in solid food, though this is disputed. Moreover, this animal is green, and since green coloring matter is one of the distinctive characters of plants, its presence in Euglena has led to much controversy regarding the classification of this organism. Peranema with its mouth and the animal habits should evidently be classed with the animals, whereas Euglena, with its green color, would naturally be classed with the plants; and yet their similarity would lead to classing them together. A further consideration of this subject will be given in a later chapter. PLANTS Although there is a difference of opinion in regard to the classification of Euglena and Peranema, there is none in regard to the organisms which are now to be described. The following organisms are always recognized as plants, although some of them, for reasons that will be given later, have certain charac- ters that have caused biologists, in the past, to group them with animals. Modern scientists, however, are unanimous in opinion, grouping the following organisms among the plants. PLEUROCOCCUS Pleurococcus appears like a green stain, growing in abundance upon damp tree trunks, fence posts, or even damp rocks. Upon scraping off some of the material and examining it with a microscope it is found to consist of a great number of small green cells. These (Fig. 30) are spherical, and contain no visible internal organs except a nucleus. The cells are found massed together into irregular bunches, but are not really attached together. As they grow in size they divide by fission in two parts, each of which divides subsequently, the new individuals sometimes remaining attached, to form irregular masses which are easily shaken apart. No other method of reproduction is known. It is possible that this little plant is really a stage in the life of some higher plant whose development is not yet known, since it has been shown that some of the more complex plants have a stage in which they are simple green cells like Pleurococcus. Concerning this organism, however, nothing is known positively except that it occurs abundantly in damp places and, so far as known, has no other phase of its life than that already noticed. a, a single cell; 6, one showing division by fission; c, a later stage of division. The plant in its growing condition is bright green. A second type of reproduction sometimes occurs in some species of yeast. Under conditions not yet clearly understood, the contents of a yeast cell breaks up into two, three, or four parts which become surrounded by thick walls; Fig. 32 s. These are called spores, or ascospores, because held in an ascus (Gr. ascus = sac) or sac, and eventually they are liberated by the breaking of the sac. Each spore is tnen capable of starting a new series of generations of ordinary yeast cells. The spores can resist drying and therefore serve to protect the yeast from adverse conditions. A comparison of Figures 30 and 31 will show that yeast and Pleurococcus greatly resemble each other in structure; but there is one important difference between them, for Pleurococcus is green and yeast is colorless. This difference in color makes a very great difference in their life; see page 131. While yeast cells may be found widely distributed in the air, in the soil, and in the water, they grow only where they find organic food to eat, and chiefly in solutions containing sugar, like fruit juices, etc. Elsewhere, in the soil or air, while they may be alive, they are dormant. The chief function of yeast in nature is to convert sugars into carbon dioxid and alcohol. Sugar is produced in great quantities by various fruits and vegetables, and is eventually attacked by the numerous yeasts that are floating in the air. After the yeasts have acted upon it, the sugar disappears and in its place can be found a gas, carbon dioxid (CO2), and a liquid, alcohol (C2H6O). This is called fermentation, and it is used extensively in the fermentative industries which produce alcoholic beverages, like beers, wines, ales, brandies, etc. The fermentation by yeasts is also made use of in the raising of bread. The yeast growing in the midst of bread dough produces bubbles of carbonic acid gas which cause the solid heavy dough to become light and spongy. The bread made from such dough is full of holes, and is more palatable and digestible than bread cooked from dough that has not been rendered light and porous (i.e., unleavened bread). In the case of bread raising and beer making, the yeast as a rule is intentionally planted in the material which is to be fermented. In the making of wines or the making of cider, yeast is not planted. In these cases, the grape juice or the apple juice is allowed to stand undisturbed, and the yeasts that are floating around in the air, known sometimes as "wild yeasts," have an opportunity of getting" into the juices, where they grow and produce fermentation. Thus although no yeast has been added to these materials, the fermentation is brought about by yeast exactly as if the yeast had intentionally been added. A, rod-shaped form, Bacillus or Bacterium; 1, Diphtheria bacillus; B, spiral forms, Spirillum; C, spherical forms, Coccus; 2, Streptococcus; D, the method of multiplication by division ; E, the formation of spores, s. A, flagella are distributed over the whole body, a condition called peritrichic; B, flagella grouped together in cluster at one end, called Jophotrichic; C, a single flagellum, monolrichic* bacteria (see Fig. 35) have minute flagella, which by lashing to and fro cause them to move. Beyond the points shown in the figures, there is very little to be said concerning the struc- ner: After growing for a time by division the contents of a single bacterium collect into a rounded mass which becomes surrounded by a hard resisting wall; see Fig. 33 E. This is set free by the breaking of the bacterium that holds it and is then capable of starting a new series of generations. This clearly resembles the ascospore formation in yeast, except that there is no actual multiplication of individuals, one bacterium giving rise to one spore only. The spores have resisting walls and are able to stand drying and a fairly high degree of heat. Their function is thus that of protecting the race from destruction by drying and heat rather than that of multiplication, the latter function being performed by the process of simple division. Bacteria are very widely distributed in nature. They are found in the air, in the soil, in all bodies of water, and, in fact, practically everywhere. They play an extremely important part in the life processes of nature through their relation to all forms of putrefaction, decomposition, and decay. The bacteria are important agents in maintaining the continued fertility of the soil, making it capable of producing crops year after year. A few species live as parasites within human bodies and th«ee of animals. These are pathogenic bacteria or disease germs. They cause many of our most serious contagious diseases like typhoid fever, tuberculosis, diphtheria, blood poisoning, etc. Thus, although they are extremely minute, bacteria are agents of great importance in the world. It is hardly possible to imagine anything more simple in structure, but at the same time of greater importance, than bacteria. The best method of obtaining material for laboratory work is to place in a number of glass jars or shallow dishes pond-lily leaves, leaves of other plants, algae of various kinds, or any other decaying organic material from ponds and ditches. Fill the dishes with water and allow them to stand undisturbed from one to several weeks. Various kinds of microscopic organisms will appear in the different dishes, from which the desired organism can be chosen. Amoeba. — A brown scum will usually appear in a few days on the surface of the water covering the decaying organic material which is likely to contain Amoebae. When this scum is scraped from the leaves and studied under a 1/6 inch objective it will usually disclose small specimens of Amoeba. The animals should be studied alive and without any special treatment, since they are sufficiently transparent, and slow enough in their movements to show all the points in their anatomy, and nearly all the features mentioned in the text may be seen without difficulty. Paramedum. — These may be found in abundance in the scum from the decaying pond weeds after they have been left for a week or more. Many white, moving bodies, just visible to the naked eye, will be found in a drop of this scum, which should be studied with a 1/6 inch objective. The chief difficulty in studying them is due to their constant motion; various methods of holding them quiet may be used. A bit of filter paper under the cover glass will sometimes hold the individuals quiet in its meshes, or they may be held quiet under a cover glass by supporting it on a small bit of paper, just thick enough to hold them without crushing them. The animals are to be studied alive, and a little patient examination of several specimens will usually show most of the points of structure mentioned in the text. To bring out the nucleus, a very weak aqueous solution of methyl green should be run under the cover glass. If the solution is not too strong it will stain the nucleii green, before affecting the rest of the organism. Animals rare and cannot be studied by a class. The other unicellular animals mentioned in Chapter II may be commonly found with Amceba and Paramedum. They cannot always be obtained, however, and the student will often be obliged to omit them. Euglena should not be omitted, however, if any appear in the dishes of decaying pond weeds. Pleurococcus. — The best method of obtaining this for studyis to find some fence post or log which is covered with a green growth. This material scraped from the wood will usually prove to be a mass of Pleurococci. No special method of study is needed except to place a small quantity in a drop of water and study with a 1/6 inch objective. The structure can be readily seen and cells may be found showing division by fission. Yeast. — A cake of ordinary compressed yeast furnishes excellent material. A small quantity should be rubbed with a little water in a watch glass. A minute drop of this material diluted still further in water, and studied with a 1/6 inch, will show the structure of the yeast except the nucleus, which can only be made out by special methods. Many cells showing buds may be found in a fresh yeast cake. Such a yeast preparation usually contains grains of starch, which may be distinguished from the yeast by running a little iodine solution under the cover glass, which will turn the starch blue. The starch has nothing to do with the yeast, being added to the cake to give it body. A few drops of the yeast emulsion should be planted in several large test tubes containing a fermentable liquid. Pasteur's solution is best, but a little diluted molasses will serve. Pasteur's solution contains the following ingredients : — If these tubes are placed in a warm place, 80° to 90° F., fermentation will soon begin, and after a few hours bubbles of CO2 may be seen rising through the liquid. After 12 hours a little of the scum or the sediment will show the actively growing yeast. This growing yeast should be carefully compared with the fresh, dormant yeast in the yeast cake. Spread a bit of any decaying matter (the decaying pond weeds will do very well, or a bit of tartar scraped from the teeth) in as thin a film as possible upon a slide, dry in air or fix by heat by passing it twice through a gas flame. When thoroughly dry flood the slide with a solution of fuchsin or methylene* blue and allow to stain for two to five minutes. Then wash the stain off in running water, and place a cover glass over the stained mass on the slide. The bacteria appear under a high power objective as minute stained dots, or short rods. They are much smaller than yeast cells, and are only just visible with a 1/6 inch objective. Higher powers are needed to study them. STRUCTURE OF ORGANISMS BEFORE undertaking the study of the multicellular organisms we must study in detail the process by which cells multiply. We have already seen that the Amoeba, Paramecium, and other single-celled animals and plants have the power of dividing. Indeed all active, growing cells have the power of multiplying by division. Although division seems a very simple process, in reality it is unexpectedly complex. The internal changes in the cell during division have been made out only by long study. While they differ in many small details, all cells agree in certain broad general facts. The process known as karyokinesis or mitosis (Gr. mitos = thread) is alike in outline in most cells and is as follows : — The Resting Cell. — In Figure 36^4. will be seen a cell in the condition of rest, before it has passed into the stage of division. It will be noticed that the centrosome is in the form of two minute granules, and that the chromatin inside of the nucleus is in the form of a diffused network. No other factors need concern us at the present time. 1. Prophase. — The first stage in the division involves both the nucleus and the centrosome. In the nucleus the chromatin assumes the form of a long thread sometimes known as the spireme. This condition, however, is only preliminary to the breaking up of the thread into a number of short pieces which are called chromosomes (Gr. chroma = color + soma — body) ; Fig. 36 B. The number of chromosomes which arise in the nucleus varies with different organisms but is constant for each species of organism and is always an even number. In the OF KARYOKINESIS A, the resting cell before it enters into the process of cell division; H, the completed process after the cell has divided into two parts; ce, the centrosome; ch, the chromatin. For description of the different stages, see text. no especial importance. 2. Metaphase. — The second stage in cell division is a very important one and is really the key to the process. Each of the chromosomes splits lengthwise into two identical halves, which at first are parallel, as at D. This splitting of the chromosome into identical halves is for the purpose of dividing equally the chromatin material, so that the two cells which are to arise from the original cell may each contain one-half of the chromatin rods of the original cell. The fact that the chromosomes split lengthwise is of significance, for it is manifest that if the thread splits lengthwise, the two halves will be essentially identical, while if it should divide crosswise, the two halves would not be necessarily alike. In the equatorial plate, at E, these eight chromosomes become slightly flattened and are drawn more closely together. 3. Anaphase. — In the third stage, the two halves of each chromosome begin to move apart. As shown at F, four of the chromosomes move away from the equatorial plate toward each of the two centrosomes. There is little doubt that the minute fibers which connect the poles of this spindle are concerned in the separation of these chromatin threads, though exactly how they work is not known. Finally, the separate halves of the chromatin thread are brought close to the minute granules lying at the two ends of the spindle, at G. 4. Telophase. — The last stage in the division simply completes the process, for the essential feature of division has already occurred. The chromatin threads, which have come to lie near the pole of the spindle, now combine and form a network, at G, much like that present in the original nucleus, and a nuclear membrane forms around this mass of chromatin material at H. The minute granule within the center of the spindle pole is divided in two, either now or later; and thus a complete nucleus is produced with a centrosome beside it, containing two granules, at H; this nucleus is an exact repetition of the one with which we started. Meantime a division plane forms, passing through the cell midway between these reconstructed nuclei, and the division of the cell into two parts is now completed. There are thus produced two cells, identical with each other and identical with the original cell, each with similar chromatin material, since each contains half of the original chromosomes. By this process, therefore, the chromatin of the nucleus is continuous from one cell generation to another. It will be evident that the essential purpose of this cell division is the splitting of the chromatin material into identical halves. It would seem much simpler for the cell to divide immediately into two parts without this long process; but this might not make the two parts equivalent. In order that they may be equivalent, the cell adopts the complicated process of karyokinesis. In the case described, the two final cells are practically of equal size; but even in instances where the cells finally produced are of very unequal size (Fig. 121), the amount of chromatin in each is the same. Since, therefore, the essential purpose of this process of karyokinesis is the splitting of the chromatin, it is evident that this material must be of extreme significance in the life of the cell. When we combine this knowledge with the fact mentioned in Chapter II, that the cell can carry on its life processes only when it has nuclear material, it becomes manifest that the nucleus, instead of being a negligible part of the cell, is really the central feature of its life. Nuclear Division without Cell Division. — As a rule, almost immediately after the nucleus completes its division, the body of the cell divides so that a cell does not contain more than a single nucleus for any length of time. Occasionally, however, the division of the cell body is delayed and the nucleus divides a second time, and perhaps several times, before the cell body divides, the result being one mass of protoplasm containing CELL MULTIPLICATION several nuclei. In most instances the division of the cell is simply delayed and takes place later, so that finally the condition of a single nucleus in each cell is resumed. This occurs in the dividing egg of insects, for example. In some instances, however, the cell body does not divide at all, and the continued division of the nucleus produces a connected mass of protoplasm with many nuclei. This occurs, for example, in some molds shown in Figure 42 E, in which there is no sign of cell division, although there are many nuclei. Such a condition is called a syncytium (Gr. syn = together + cytos = cell) and is sometimes described as acellular. This multicellular state with incompleted cell division is rare, for in most instances the division is completed promptly. Amitosis. — While division by karyokinesis is the common method of cell division among all organisms, there are some instances where cells divide without going through these stages. This is most likely to occur in the old age of the cell when its vitality begins to decline. In these cases, the nucleus divides directly ; sometimes being simply pinched into two parts (Fig. 37), sometimes being compressed into a middle plate which divides into two halves and then separates, and sometimes forming two nuclear membranes inside of the original membrane which then ruptures and permits the escape of the new nuclei. In these cases, it frequently happens that, though the nucleus divides, the cell body does not divide, so that 'there results a cell with more than one nucleus. This process of division is called amitosis (Gr. a = without + Lat. mitos = thread), and it is thought to indicate a decline in the vigor of the cells. UNICELLULAR AND MULTICELLULAR ORGANISMS All of the organisms thus far studied have been made up of single cells, each cell being independent and capable of carrying on all life processes within itself, although many of them are quite complex, having several organs and much variety; see Fig. 38. In contrast to these unicellular organisms we shall find organisms made up of large numbers of cells (multicellular organisms). All of the larger and higher animals and plants in the world are made up of great numbers of cells, each having the same general structure as the unicellular organisms we have already studied. These larger organisms begin their life as single cells and become multicellular by the division of their cells into many parts. There is no doubt that the ~ multicellular organisms of the on the other hand the cells are all alike, are all capable of carrying on the various functions of life, and may be more or less independent of each other. Vorticella and Carchesium. — Other examples of types intermediate between unicellular and multicellular forms are shown in Figures 39 and 40. The Vorticella, shown at Figure 39 A, Showing the formation of colonies. A, a single-celled Vorticella; B, the process of division; C, a single cell of Carchesium; D, a colony of Carchesium, produced by the incomplete division. Vorticella always separates after division, but Carchesium remains attached as shown at D, mic, micronucleus. is unquestionably a single-celled animal, bell-shaped and possessing cilia, a mouth, oesophagus, vacuole, and a macroand micronucleus; the whole is attached to a stalk containing a muscle which enables it to contract. This single cell divides in a normal manner (B) and after division the parts separate to become independent animals. In Figure C is shown another cell much like Vorticella, possessing the same shape and similar organs. In this animal, after the cells divide, they do not separate but remain attached to a common stalk, and subsequently divide again and again, the result being a group of similar cells connected by a branching stalk, D. This animal is named Carchesium, and such a cluster is called a colony. In this colony the members are independent, each carrying on for itself all of the functions of life and each contracting and expanding by itself independently of the rest. A third species is found resembling Carchesium except in one respect. wholly independent but have a vital connection. There are many other animals which are in a similar way made up of colonies of cells, alike in structure and function. Several of these are sho\/n in Figure 40. In all cases the animals start their life as single cells which become colonies by the method of incomplete division. All these are commonly classed among unicellular animals and called Protozoa (Gr. ATTACHED TOGETHER A, an animal with its pseudopodia protruding; in the other specimens only the shell is visible. These animals belong to the group of Forminifera, whose shells form chalk cliffs and limestone rocks. of which a single example will be given. Ulothrix. — One of the common fresh-water pond scums, found everywhere in ditches by the roadside, is made of a green plant, Ulothrix; Fig. 41. Ulothrix consists of a long, slender thread formed by a row of nearly cylindrical cells, placed end to end; Fig. 41 A. The individual threads are barely visible to the naked eye. In each one of these cells rnay be seen green coloring matter, chlorophyll (Gr. chloros = green + phyllon = leaf), and each cell contains a nucleus. The cells are identical from one end of the thread to the other, differing only slightly in come out, each is seen to be provided with four little flagella and is thus enabled to swim. They are called zoospores (Gr. zoon = animal) ; Fig. 41 a. After swimming for a time they settle down, lose their cilia, and OF SINGLE CELLS A, Ulothrix. a, shows the process of multiplication by the formation of zoospores; b to /, show the formation of sex cells, their conjugation with each other; g, their subsequent division into spores; h, a single spore which grows into a new thread, like the original shown at large A. B, Pediastrium. each begins to develop into a new filament like that from which it originated. The growth into the new filament is by division; the cells after dividing remain attached together in the form of a long chain. The second method of reproduction is by conjugation and reminds us of that in Pandorina. In this case, the contents of some of the cells break up into a large number of parts instead of a small number, and these, by the bursting of the cell wall, are finally liberated into the water ; Fig. 41 c. They are then found to possess two flagella, instead of four like the zoospores, and by means of these they swim around. These small spores are, however, unable to grow into new threads.* After the spores have been swimming about foi some time they come in contact, as shown in Figure 41 d, and fuse together, the fusion being identical with that already described in Pandorina; see page 74. There are thus formed conjugation spores known as the zygospores (Gr. zygon = yoke). These zygospores, after a time, produce by division several more spores which, upon becoming free, soon begin to divide and grow into new filaments like those with which we started .. This kind of reproduction is very similar to that of Pandorina and clearly suggests the sexual reproduction which occurs in higher organisms. In the organisms thus described, we have examples which cannot properly be called unicellular, nor on the other hand can they be called multicellular; each one of these cells carries on by itself all the functions of the organism, whereas in multicellular organisms, as we shall presently see, the different cells have different functions to perform, and the cells that make up the individual are not all alike as they are in the forms already described. We must look upon the Pandorina and Ulothrix as intermediate between the unicellular and the multicellular forms. In this way they illustrate the general biological principle that sharp lines dividing groups can hardly ever be drawn, and it is almost always possible to find intermediate forms connecting widely separate types. True Multicellular Organisms. — Multi cellular organisms are always made up of more than one cell; but the fact that they consist of many cells is not enough to define them accurately. A brief account of the manner in which multicellular organisms develop will explain the meaning of the term. In all cases they begin as a single cell, Which may be either an egg or a spore. This cell divides into two parts, these into four, and so on, the number of cells increasing indefinitely; but after dividing, the cells remain attached instead of separating. After a while some of the cells assume a variety of types, i.e., they become differentiated in form and function, and play different parts in the life of the organism. Such a differentiation of cells occurs in all true multicellular organisms. Hence we may define a multicellular organism as one composed of many cells which show a differentiation in structure and function. With this differentiation of cells, tissues appear for the first time. Cells with similar structure and function are commonly grouped together, to form a tissue. The cells with special contractile power, for example, form muscle tissue; cells with power to secrete bone form bony tissue; and those in which conductility and irritability are particularly developed are grouped together to form nervous tissue; and so on. Tissues are, of course, impossible among unicellular organisms, but universal among multicellular organisms. With the multiplication of cells and their differentiation, there also appears the formation of true organs. Among the unicellular animals and plants there may be certain parts of the cell, like the mouth and nucleus, set apart for certain functions, and these are, to be sure, cell organs. But they are not organs in the sense in which the term has been used among the multicellular animals, where groups of cells, usually of various kinds, are aggregated to form distinct parts with grouped together to form a complex structure. In the study of multicellular organisms, which follows in the later chapters, it will be seen that some of them have only a few simple organs, while others have many complex organs. Those which are of simple structure and have few organs we call low organisms, while by high organisms we refer to those whose structure is complex. PEN1CILLIUM, A SIMPLE MULTICELLULAR PLANT As an example of a multicellular plant with very slight complexity, we will study one of the common molds, which may be found growing upon almost any moist food the world over. It may usually be obtained in abundance by placing a bit of bread or a slice of lemon in a dish, covering it so that it will be kept from drying, and allowing it to remain in a warm place for a few days. The object will soon become covered with a mold (Penidllium) which after a day or two assumes a greenish-blue color. This organism is somewhat difficult to study under the microscope because it is so massed together that special methods have to be taken for preparing the specimens. The best method is to plant some of the spores upon a little jelly which has been hardened on a glass slide, and then study the spores under the microscope every day and notice the method by which they sprout and eventually form the complete plant. Structure. — The structure of Penidllium may best be understood by studying Figure 42. It is made up of a mass of delicate, branching threads, extending in various directions. These threads are white or colorless and very minute. In the common species of Penidllium they are hardly visible to the naked eye, although in some species of molds they are slightly larger, and in others they are large enough to be plainly seen. These threads, which are known as the mycelium (Gr. mykes = fungus), have the function of assimilation, and absorb nourish- ment from the substance upon which the molds are growing. Although the threads are very delicate, they can by growth force their way through the substance upon which they are feeding until they penetrate into the bread, or slice of lemon, A, a colony of Penicillium, showing the fruiting spore-bearing masses arising from the mycelium; B, a bit of the colony more highly magnified; C, one of the fruiting masses, forming spores; D, a colony of Mucor; E, the sporangia of Mucor, with the spores emerging, and showing also the mycelium below not divided into cells; F, a bit of the colony of Aspergillus, showing a third method of formation of spores. or decaying apple, for some distance, and the material thus becomes permeated with the mycelium. Careful study of the threads of this mycelium with a high magnifying power shows that they are made up of many cells. Cross partitions divide the threads at intervals and separate the consecutive cells; Fig. 42 B. The contents of each cell include protoplasm and a nucleus. There is no differentiation of the cells, all in mycelium. Reproduction. — The only noticeable differentiation of cells that is seen in Penidllium occurs after the plant has grown for a few days and is ready for multiplication. There may then be seen arising from the mycelium minute branches that extend vertically into the air instead of growing horizontally over the surface of the object upon which the mold is nourishing itself. These rise from the mycelium, simply as branches, and are known as aerial hyphae (Gr. hyphe = web) ; Fig. 42 B and C. The ends of these hyphae branch into a number of finger-like processes, which extend vertically, parallel with each other, as shown at C; after a time these branches divide by constriction into rows of minute balls. These little spheres eventually break off from the plant and then, blown by the wind, are scattered far and wide. Each of them is capable, under proper conditions of jnoisture and temperature, of developing into a new plant. They are evidently spores, this particular kind of a spore being named conidia (Gr. konis = dust). The conidia are bluish in color and they cause the mold, which is at first white, to assume a distinct blue tinge, giving to this plant its common name of blue mold. They are extremely light and may be blown for a long distance before settling to the ground. Whenever they do settle upon any moist place they germinate; each spore produces a new thread which in the course of a few days becomes a new, branching mycelium and thus forms a new mold. The conidia produced by a single plant are very numerous and so light that they may be carried for a long time in the air. Indeed, the air is at all times more or less filled with them, in summer and winter alike; and it follows that any moist material which will furnish them with food, like bread, or pieces of lemon, or the surface of any fruit, if exposed to the air for a short time, will be sown with these little spores, and in a few days will begin to show signs of molding. So widely scattered are these floating mold spores that it is hardly possible to expose any moist organic substance even, for a few minutes, without its becoming inoculated with some of them and showing, a few days afterwards, the growth of molds upon its surface. Penidllium has a second method of multiplication which is rarely seen. It occurs only under special conditions which are not understood, and it has not been observed by many botanists. It consists in the formation of minute sacs, within which spores are formed, usually four or eight in number. These sacs are known as asci and the spores are ascospores. Eventually the sacs burst, the spores come out and are then capable of developing into new plants. This method of forming spores is evidently similar to that already described in Yeast (see Fig. 32 s), and shows that yeast is closely related to the molds. The same method of spore formation is found in a large number of other plants (lichens, cup fungi, etc.) and is used as a basis of classification for a class of Fungi called Ascomycetes (Gr. ascus = sac + mykes = fungus). It must be no^ed, however, that not all of the molds form spores in this way. The one shown in Figure 42 D has a method of reproduction by conjugation. OTHER SPECIES OF MOLDS Molds are very abundant in all parts of the earth wherever there is much moisture, and any bit of organic material left to itself will be sure to show signs of their growth in course of time. Many species of molds, which to the naked eye closely resemble each other, may be distinguished by careful microscopic study. In all cases the plant is a branching, colorless mycelium, similar to that described in Penidllium. In a few species, however, the mycelium is not divided into cells by partitions, as in Penicillium, but the whole thread forms one continuous mass called a syncytium; Fig. 42 E. The chief method by which the molds are distinguished from each other is not by the structure and shape of the mycelium, but rather by their method of producing spores. Penidllium is one of the more common, but there are many other species in which the spores are produced by different methods. Three of these methods of spore formation are shown in Figure 42 C, E, and F. In some cases the spores are formed in a sac called a sporangium, as at E. In others they are borne upon a globular head, not inclosed in a sac; see F. Other species show various methods; but in all cases the method of spore formation is quite distinctive, and a careful microscopic study of the different forms makes it possible to separate them into species according to their methods of producing spores. Molds play a very important part in the life processes in nature. The term mold is not a proper scientific designation for these plants, but a popular name, covering a variety of plants of similar form and structure, but with many different botanical relations. That they belong to different groups is proved by the fact already mentioned that they have different methods of reproduction, some of them forming ascospores, while others form spores by a process of conjugation, which, as we shall learn later, is a type of sexual reproduction. The laboratory work that can be done by an elementary class upon karyokinesis is very limited. Mounted preparations should be furnished by the instructor. For this purpose the young growing root tips of Podophyllum are excellent. If these are collected in the spring and carefully preserved, sectioned, and stained in iron haematoxylin, they will show all stages of cell division. Longitudinal sections are. best, and they should be studied with a 1/12 immersion objective to make out the details. By patient study of a few sections thus prepared the various steps in karyokinesis may be made out. Carchesium. — Colonial forms of Vorticella-\ik.e organisms, either Carchesium or Zoothamnium, may usually be found in aquaria in which various fresh- water plants are kept. The dishes which have been prepared for the culture of Amceba and Paramecium will frequently show them. If they are obtainable they should be studied. No special methods are necessary, the colonies being small enough to be placed under a cover glass and studied alive. Staining with methylene green is useful to bring out the nuclei. Ulothrix or Spirogyra. — One of these forms should be studied as an example of filamentous plants. Either of them may be found in ponds or ditches by the roadside. They are to be studied without any special preparation, the fresh form showing most points perfectly well. The shape of the cells and of the chlorophyll bodies should be noticed. The nucleus may usually, though not always, be seen without any treatment. A little glycerine added underneath the cover glass will cause the protoplasm to contract from the cell walls. Staining with methylene green will show the nucleus if it has not been seen without this. If material is at hand to show the conjugation, it is desirable to have the student study threads of conjugating Spirogyra and compare with the conjugation of Paramecium described in the text. The reproduction of Ulothrix by formation of spores is so difficult to obtain that it is impractical to furnish material to a class for study. Penicillium and Other Molds. — Molds may be easily obtained by allowing bits of lemon, banana, bread, etc., to remain for a few days in a closed jar in a warm place. The general appearance of the molds can be studied on the surface of these articles. For a more careful study it is necessary to study the colonies growing from spores. A simple method is as follows: Prepare a culture medium from dried beans by placing a pint in about twice as much water as is necessary to cover them. Allow to stand 12 hours and add enough water just to cover the beans. Then strain off the liquid from the beans and filter. To the filtrate add 1% of agar and boil so as to completely dissolve the agar. Place the material in test tubes, about 10 c. c. in each, and plug the mouths of the tubes with cotton. Place in a wire basket and sterilize by steaming for three-quarters of an hour on three successive days. To use this culture medium, melt several of the tubes of agar and pour each into a petri dish, allowing the agar to harden. When thoroughly hard, remove with a platinum needle a minute quantity of the spores, which appear on the mold on the lemon or bread, and just touch the surface of the agar with the spore-laden needle tip in several places. This will sow the spores. Place the petri dish (covered to prevent drying) in a warm place. This dish may then be studied from day to day by putting it under a microscope, and the sprouting of the spores, the growth of mold colonies, and their production of spores can be followed in detail. Several kinds of mold will usually start to growing on the lemon etc., and may be distinguished by their color. The different species will show differences in spore formation. Sketches of the colonies and their method of spore formation should be made. The type which will be most commonly found are Penicillium, Aspergillus, and Mucor; Fig. 42. THE plants hitherto mentioned do not possess flowers and belong to what are called the flowerless plants or Cryptogams (Gr. cryptos = concealed + gamos = marriage). As an example of the higher multicellular plants we will describe one of those producing true flowers, i. e., one of the flowering plants or Phanerogams (Gr. phaneros = open + gamos) . For this purpose we will study the castor bean. The castor bean (Ritinus communis) is the plant from which castor oil is obtained; it is also used as an ornamental foliage plant on account of its large, beautiful leaves. Other plants may serve for this study, but this one illustrates especially well the structure of the higher plants. The seeds may be obtained at seed stores and will readily sprout in moist sawdust. GROSS STRUCTURE Figure 43, which represents a young seedling of the castor bean about two weeks old, illustrates the general structure of other multicellular plants, since the higher plants are essentially alike in this respect. It consists of a stem connecting two expanded surfaces, the one ending in the leaves, and the other dividing under the soil into fine rootlets which bear root hairs. Plants obtain their food partly from the air and partly from the soil, and this explains why they expand their branches into leaves in the air, and their roots into root hairs in the soil. The stem of the plant serves chiefly as a connection between the leaf and the root and as a support for the branches and leaves. the outer edge. The large cells in the center form the pith. On the outer edge of the stem is a single layer of small rounded cells forming the epidermis (Gr. epi = upon + derma = skin), ep. Just beneath the epidermis are several irregular rows of cells, larger than the epidermal cells, known as the cortex (Lat. cortex = bark), co. At this stage the cortex on its inner edge is not very sharply marked off from the cells which fill the center of the stem, and form the pith. THE CASTOR BEAN known as fibrovascular bundles (Lat. fibra — fiber + vas = vessel). In the young stem there is a row of eight to ten of these groups, arranged to form a ring a short distance beneath the epidermis. The bundles do not actually touch each other, but the cells of the pith and st, stereome cells. triangular mass of cells, the walls of which are thicker than those of the cambium. Among them may be seen at least two kinds of cells; one of small size but with very thick walls forming the tracheids (Gr. trachea = windpipe) or wood cells, t, and the other of larger size with relatively thin walls, forming the ducts or vessels, d. 3. On the outside of the cambium, and therefore toward the epidermis, is a somewhat irregular mass of cells called the phloem (Gr. phloios = inner bark), ph, within which may be seen four kinds of cells. There are a few large cells called sieve cells, Sj and near them some small cells called the accompanying cells, a. Other cells still smaller and with thin walls form the parenchyma (Gr. para = beside + en = in + chein = to pour), pa, and a few cells, with very thick walls, are called the stereome cells (Gr. stereos = solid), st. The cells of the cambium do most of the growing; as they multiply they produce new cells both on their inner and their outer edge, causing the bundles to increase in thickness by additions between the xylem and the phloem. types. The large ducts have peculiarly marked cell walls. Some of them show rings forming thickenings on the inside of the cell wall, or the thickenings may take the form of a spiral, sp. Other ducts show dots or pits and various peculiar markings, d. The smaller cells, the tracheids, t, are much narrower than the ducts, but have relatively thicker walls. Some have square ends and others have ends tapering to a point, the cells dovetailing to form the hard, resisting part of the stem; the phloem outside the cambium layer also contains several kinds of cells. Some of them are large and have oblique ends which are perforated by apertures that place one cell in communication with the next above and below. Because of these openings, these cells are called sieve cells. It is through these cells that the food supply is transported through the plant from the leaves. Close to the sieve cells are smaller cells, the accompanying cells, a, which are long and slender. The phloem also contains many rather narrow cells with square ends called parenchyma cells, and a few small, short cells with very thick walls known as stereome cells. vascular bundles is better shown in Figure 47, which shows how the bundles extend through the stem and strengthen it. The bundles evidently consist of very different material from that found in the pith FIG. 47. They are mostly long, narrow cells with comparatively thick walls, which are hardened by the deposition of woody substance. The name fibrovascular is appropriately applied, since they are principally made up of fibers mixed with vessels. The strength of a stem depends upon the density of these bundles, and the thickness of the walls of the tracheids. Of all this mass of cells only a few are filled with living protoplasm. The cambium cells are always alive and the sieve cells may contain protoplasm. The other cells contain protoplasm when they first form, but when they are fully grown most of them are only the empty cell walls. This is particularly true of the wood cells of the xylem. Protoplasm is more usually found in the phloem and the cortex than in the true wood. portion of the stem, which is now called the phloem or bark, from the inner part, the xylem, or wood proper. Later the other parts of the bundles fuse, forming a complete ring of woody tissue and a complete ring of bark separated by the cambium. FIG. 49. — DIAGRAM SHOWING THE METHOD BY WHICH THE CAMBIUM LAYER PRODUCES WOOD CELLS ON ITS INSIDE AND BARK CELLS ON THE OUTSIDE we, the wood cells. increase in size. As the cells of the cambium layer divide, new cells are formed between the bark and the wood of the old bundles. Some of these new cells are formed inside of the cambium layer, and outside of the xylem, as shown diagram matically in Figure 49. the cambium assume the form of sieve cells, parenchyma, etc. It thus comes about that the plant is producing new wood cells in the form of a layer outside the old wood ring, and new phloem cells in a layer inside the old phloem ring. The wood grows by additions upon its outer surface and the bark by additions to its inner surface. Since the cambium forms a complete ring, this method of growth evidently will produce a complete ring of wood around the stem, and since the cambium cells continue to produce new cells during the whole of their active life, they will continue to add new layers of wood on the outside of the old wood. The wood ring, which at first is only a thin layer just inside the cambium, becomes thicker and thicker as the growth continues. As it becomes thicker, the stem, of course, increases in diameter, and, since the cambium always remains on the outside of the wood, the stem may keep increasing in size as long as the cambium cells are able to develop new cells to be deposited as wood cells on the outside of the old wood. In the same way the cambium deposits masses of cells on the inner side of the phloem of the bundles, and the bark also increases in thickness by growing on its inner side. This growth is, however, not so vigorous as is that of the wood, and the bark does not increase in thickness so much as does the stem. Since too the new cells of the bark are deposited on the inner side, the older parts of the bark must stretch to cover the increasing diameter of the growing stem. When a stem becomes of considerable size the outer bark will be found to be rough and broken by the expansion of the stem which it covers. Some plants, which have but one year's growth, form a single ring of wood as described, and die at the close of the season. Other plants, like large trees, do not die, but live year after year; and each year the cambium layer adds new masses of cells outside of those previously existing. In plants that live in regions where the climate changes with the seasons, narily a year's growth, the age of the plant may be determined by counting the number of rings. Such rings are rarely visible in the bark, although the bark also increases in thickness by layers added to its inner side. From this description, it is evident that the growing part of the stem is the cambium layer and that the stem of the plant is capable of continuing its life only as long as this cambium layer is intact. What is known as girdling a tree consists in cutting a ring through the bark around the tree in such a way as to destroy entirely the bark and the cambium layer; this effectually kills the tree because the cambium layer is destroyed, and unless there is a connection of living cambium between the roots and the leaves, the life of the plant cannot be maintained. It is also evident why the bark may be stripped away from the wood ference of the material from the outer part of the stem toward the center, or the reverse. This type of stem is called an exogenous stem (Gr. exo = outside + genes = a producing) , a name given to it from the fact that it grows by the addition of new layers of wood upon its outer side. Such a stem may increase enormously in thickness; some trees live for many hundreds of years and become several feet in thickness. cambium cells. As a result, they have no growing layer and are not capable of increasing in size. Such a stem is known as an endogenous stem (Gr. endon = within + genes), and belongs to a type of plants, like the grasses and bamboos, that grow tall and slender. Their stems are only a little larger at the bottom than at the top and do not materially increase in diameter. This type of stem forms a totally different group of plants from the first, differing in many respects in their leaves and flowers, as well as in their stem structure. STRUCTURE OF THE ROOT The structure of the root of the castor bean resembles that of the stem, with some noticeable differences. A cross section shows that the cortex is very much thicker than it is in the the substance of the root itself. From here they pass from cell to cell, and eventually find their way to all parts of the plant. The root hairs, constituting the absorbing organ of the plant, are of great functional value. If a plant is forcibly pulled out of the soil, all of the root hairs are torn from the root and left attached to the particles of the earth. If, however, the whole plant is removed from the ground and the soil is carefully washed from the roots, the root hairs may be found still attached to the rootlets, and may show grains of sand attached to the root hairs. A complete leaf consists of three parts: The broadly expanded blade; the contracted stem or petiole; and two little appendages called stipules attached to the base of the petiole where it is connected with the stem. The stipules are not present in all leaves and are not found in the castor bean. Running from the top of the petiole out into the blade are a series of fine veins; in some plants they run in a parallel direction (parallebveined leaves), and in others they branch profusely into many small twigs (netted-veined leaves). Minute Structure of the Leaf. — A section across the petiole of a leaf shows a structure similar to that found in the stem of a plant, except that there is no regular ring of fibrovascular bundles and no cambium layer. In this petiole may be seen several fibrovascular bundles separated from each other; and if these are traced down to the stem from which the petiole of the leaf arises, they will be found continuous with the fibrovascular bundles of the stem. Followed into the blade of the leaf, these bundles are found to pass out into it and form the veins. Thus the veins of the leaf are simply an extension of a few of the fibrovascular bundles that come from the stem. Being hard and tough, they give sufficient rigidity to the leaf to support the softer parts, which are the active portions of the leaf structure. st, the stomata. of the leaf that the most important function of plant life is carried on. Upon its upper and under surface there are single layers of cells, the epidermis; Fig. 57 ep. These are made of small, irregular cells, closely compacted together and possessing and even to gases. They form a covering of the leaf which prevents the entrance of water, and protects it from too great a loss of water by evaporation. Through the epidermis are numerous openings known as stomata (Gr. stoma = mouth), st, that serve as breathingpores. If a bit of the epidermis is stripped from the leaf, it will appear as shown in Figure 58. The cells of the epidermis are irregular in shape, due to the irregular growth of the leaf, and among them are numerous pores. Each pore is surrounded by two crescent-shaped cells, guard cells, so related to each other that the pore itself lies between the two crescent cells. The guard cells are capable of expansion and contraction under different conditions. As they expand, they straighten out floats on the surface of the water. The shape of the stomata and guard cells varies slightly in different plants, but their structure is always essentially like that seen in the Figures 58 and 59. In the middle of the leaf may be seen cross sections of the veins, which are typical fibrovascular bundles (Fig. 57 /&), composed of essentially the same kind of cells that we have found in the bundles of the stem. The rest of the substance of the leaf is filled with a loose mass of cells which are the active cells of the plant. Immediately under the upper epidermis is a layer of slightly cylindrical cells forming a fairly definite row. These are called the palisade cells; Fig. 57 p. They contain minute granules (chloroplasts) of green coloring matter called chlorophyll (Gr. chloros = green -f phyllon = leaf), cl, and each contains protoplasm and a nucleus. Below the palisade cells are other cells more irregular in shape and more loosely packed. In this part of the leaf these cells are called mesophyll cells (Gr. mesos = middle + phyllon = leaf),ra, and their shape is so irregular and they are so loosely packed that many air spaces communicating with the exterior through the stomata are left between them. These mesophyll cells are filled with active protoplasm and crowded with chloroplasts (Gr. chloros = green + plastos = molded) . The intimate connection which these chlorophyll-bearing cells have with the air that enters through the stomata is evident from Figure 57, and is a matter of extreme significance, since these cells extract from the air the food from which the plant manufactures starch, the first step in the production of food for all animals and plants; see page 129. The epidermis of the leaves of some plants has various other structures. Not infrequently it is prolonged into hairs of various shapes and sizes; sometimes these hairs have a little poison at their ends and then they constitute nettle hairs. The general function of the hairs is to protect the plant from injury by small insects and other animals. REPRODUCTIVE ORGANS The organs which are designed for reproduction are widely different in different groups of plants. Among the higher plants this function is carried on by specially modified branches known as flowers. Although the greatest variety is shown among the flowers of different plants, when compared they are readily seen to have the same general structure. The following description is not that of the flower of the castor bean, or of any other plant, but an ideal description of a typical flower, and in a general way applies to the flowers of all the higher groups of plants. closely attached to each other that they appear to arise at the same point of the stem; careful study, however, shows that in all complete flowers the four different kinds of leaves are produced one row above the other. The Calyx composed of Sepals.— The lower row, which is on the outer side of the flower, is made up of small parts which are usually green and leaf-like in appearance. This row is known as the calyx, and the leaves of which it is composed are called sepals. The Corolla composed of Petals.— Just above and within the calyx, in an ordinary flower, is a second row of leaves, usually larger than the calyx and of some brilliant color. This row of leaves is known as the corolla and the individual leaves as petals, pi. It is these colored petals that give the flower its brilliancy, and their function seems to be to attract the insects, that are useful to the flower in producing cross fertilization; see page 267. The calyx and corolla together are sometimes known as the perianth (Gr. peri = around -f anthos = flower). In some flowers either the calyx or the corolla may be lacking, and in others both may be lacking. When only a single row of leaves is found in the perianth, it is customary to call it a calyx, irrespective of its shape and color, and such plants are usually spoken of as apetalous (Gr. a = without + petalon = a leaf). The Stamens. — Within the petals is a FIG. 61.— THREE third row of leaves, the stamens, st, which, however, have almost wholly lost their resemblance to leaves. Each of these consists of a delicate stem, called the filament (Fig. 61), at the top of which are little sacs, usu- of splitting open to dia, ally two in number, which are known as the anther, a. Within these sacs are. produced large numbers of spores, the spores in this case being called pollen; Fig. 62. The stamens are usually as many as the petals, although in some flowers there are two or three times as many, and in A, section across the anthers, showing the four cavities with the pollen, p, enclosed; B and C, pollen grains; n, nucleus; sp, the pollen cell or microspore. of as imperfect flowers. Carpels. — Within the stamens is the fourth and last row of leaves. In this case the parts have lost all resemblance to leaves and in ordinary flowers they would never be thought of as corresponding to fruit); Fig. 60 car. Each carpel consists of three portions, a lower, somewhat expanded portion known as the ovary (Fig. 63 ov), and above this a more or less elongated, slender part, called the style, s, whose upper, slightly roughened surface is known as the stigma, st. These three parts form what is commonly called the pistil. It frequently happens that the number of carpels is less than that of the calyx, corolla, or stamens. Moreover, the carpels are often so fused together that it is impossible to count distinctly the separate carpels of which it is composed. When this occurs, there is found in the center of the flower what is known as a com- easy to perceive this condition in the pistil and to determine the number of carpels of which it is made. The pistil shown at Figure 63 B is evidently made up of three carpels, with fused ovaries, but remaining more or less separated from each other above. In some cases the style and stigmas, as well as the ovaries, are fused together, and it is more difficult to determine the number; but even in these cases we can easily distinguish in a compound pistil the number of carpels of which it is composed, by counting the number of rows of seeds in the ovary, there being usually one row of seeds for each of the carpels in the compound ovary. DEVELOPMENT A, showing the immature ovules with the enclosed spore, s; B, the older ovules, containing an egg, e; C, the ripened ovary with the seeds, sd, each containing a young embryo plant. one or two eggs, e. As these spores produce eggs, which are the female reproductive bodies, we may speak of them as female spores. Older botanists, before their real — -\£ nature was understood, called them by the name of embryo sacs. The small spores (pollen) produced in the anther, on the other hand, are spoken of as male spores, inasmuch as their function in reproduction is that of the male. Fertilization. — The pollen grains, or male spores from the anther, are carried by some means to the stigma of the stamen. They are sometimes carried by insects, sometimes by wind, or by various other means. The stigma on the top of the pistil is usually rough and sticky, and the pollen grains readily adhere to it. In this position, the pollen grows and a long tube arises from each pollen grain and pushes its way down through the style and within the ovary; Fig. 65 pt. This tube is the pollen tube. In the FIG. 65. — meantime the female spore in the ovary has proLONGITUDI- duced the egg. The pollen tube is attracted to the egg, and finally its tip comes in contact with CARPEL it- Inside of this pollen tube is found one or showing the more special cell nuclei which are carried in the ?achedntop'the tip of the growing tube and finally pass into the SKIS poT egg, fusing with it. This latter process is called whichbehap's fertilization. The The Seed. — After the egg, which is a single cell, has fused with the contents of the pollen tube, it divides, and in a few days produces a little multiceilular plant. This plant, while still in the ovary of the pistil, develops a stem and one or more leaves; Fig. 64 sd. The pollen because of the small size, is also called a microspore, and the spore in the ovary, being larger, is called a megaspore or macrospore. The significance of this we shall notice in a later chapter. After a few days it stops growing and becomes surrounded by a hard shell, and is now known as a seed; in this form, protected by its shell, it may remain dormant for some time. If any seed is carefully examined it will be found to contain a little plant, or in the seed, either around the seedling or within it, a quantity of food upon which the young plant can feed during the first few days of its life, before it can feed itself from the soil. This whole process of fertilization, growth into a little plant, and the development of the shell around it to form a seed, occurs within the pistil of the flower. The flower in the meantime withers and the ovary increases in size to accommodate the growing seeds. Eventually, the fruit is broken open (dehiscence) and the seeds drop out. When this occurs the duty of the flower is over and all its parts decay, leaving the plant without flowers until the next season. From this description, it will be seen that there are in the flower at least four different kinds of reproductive bodies: the male spores, or pollen; the female spores, or embryo sac; the eggs which develop from the female spores and finally grow into seeds; and the male nuclei inside the pollen tube which fuse with the Seeds may be obtained at almost any seed store. For the study of the seeds they should be soaked over night in water, which will soften them so that the outer covering may be removed and the seed readily dissected. The study of the plant structure should be made from young seedlings. Soak the beans in water over night and then plant them in a box containing moist sawdust, covering the box with a piece of glass to prevent evaporation. Place the box in a warm place and water the seeds daily, keeping the sawdust quite moist. The seeds will sprout quickly and at varying periods of growth plants may be removed, the sawdust washed from their roots, and the plants studied as a whole. For the study of the stem both cross sections and longitudinal sections should be made with a sharp razor, the piece of the stem to be sectioned being held between two bits of pith which are hollowed out to receive them. These sections may be mounted in water and studied directly, without any further preparation. Some points can be seen more satisfactorily by the use of various stains. It is best to begin with the study of a young seedling about two inches high, and to follow with older plants which will show the growth of the fibrovascular bundles and their fusion into a ring. All of the points mentioned in the text should be studied. The study of the root is made in the same way. To obtain root hairs, it is better to sprout sunflower seeds by placing them, after soaking in water, between two layers of blotting paper in a covered dish, which should be kept moist and warm. After two or three days the rootlet of the young seedling will show a mass of root hairs. They should be examined through a lens without disturbing the seedling, and then one of the rootlets should be placed in a watch glass in water and examined with a microscope. The epidermis of the leaf may be studied by stripping off with fine forceps a bit of the epidermis from the upper or under side of a leaf. Any plant will serve for this, and it is well to examine the epidermis of several different plants. The study should be made with a high power. The internal structure of a leaf must be made by cross sections. These are very difficult to make, and prepared, stained sections should be furnished by the instructor. apple, or oak which show about three years' growth are satisfactory. The wood is hard to cut and is apt to injure the razor. It may be softened by soaking the stem in a mixture of equal parts of alcohol and glycerine. The stems should remain in this mixture for several days at least, and may be left in it for months without injury, and be ready for section at any time. For the study of a flower any simple wild-flower may be used to show the general relations of the reproductive organs. A common Trillium is an excellent example. The grosser anatomy of the flower should be studied; sections should be made through the ovary both of a young flower and, if possible, of the fruit after the flowering is completed, in order to show the chambers of the ovary and the seeds with their attachments. The pollen should be examined with a microscope. THE PHYSIOLOGY OF A TYPICAL PLANT IN order to carry on its life a plant must have an income of matter and energy. The problem of energy will be reserved for a later chapter: only a consideration of the relation of plants to their food and its utilization will be given here. amounts, absorbed from the soil by the root hairs. The carbon dioxid and water are absorbed by the plant in enormous quantities and constitute by far the largest proportion of their foods; the soil minerals, although absolutely necessary, are needed only in small quantities. Roughly speaking, the amount of material absorbed from the soil is represented by the ashes that are left after a plant is burned. All of the minerals are dissolved by the waters in the soil and absorbed in this form by the root hairs. Ascent of Sap. — Since the foods are obtained through organs situated at the opposite ends of the plant, in order that they may be utilized they must be brought together, and since it is in the leaves that they are utilized, the water, containing the dissolved minerals absorbed by the roots, must be carried up the stem to the leaves. This ascent of sap is going on constantly during the activity of the plant and its rapidity is proportional to the activity of the processes going on in the leaves and buds. PLANT PHYSIOLOGY 127 The method by which the sap is carried up the stem is only partially understood; there are several factors concerned. One factor is osmosis. The water from the soil is absorbed by the root hairs principally through the physical force of osmosis, a force which is capable of causing some substances to pass, even against resistance, through the thin-walled root hairs, while others are rejected. An osmotic pressure is thus produced in the root, due to the absorption of liquids from the soil, and this forces a current up through' the stem. A second factor is the absorptive power of protoplasm. Living protoplasm has a strong avidity for water and absorbs it until it is saturated. If a plant were in absolute equilibrium, each bit of protoplasm would absorb all the water that it could obtain and a condition of rest would soon appear. If, however, a cell loses any of its liquid, it will have at once a stronger demand for water than before, and will tend to draw it away from neighboring cells that are more nearly saturated. Hence in a plant there will be a constant flow of water from saturated parts to those less saturated. In an ordinary green plant there are several processes that use up the water, all of them especially active in the leaves and growing buds at the top of the plant. These are as follows: — growing buds, and this new protoplasm demands water. 3. Water constantly evaporates from the leaves through the stomata (transpiration). The extent of this evaporation varies greatly with the warmth and dryness of the air and also with the extent to which the stomata are opened. When there is abundance of water in the plant, the stomata are widely open and evaporation is rapid; but when the water is insufficient these pores partly close and evaporation is checked. On a warm day when the air is dry the evaporation is increased, but in a cool damp atmosphere it is lessened. contributes to the flow of sap is uncertain. These factors combine to produce a lack of water at the top, and an excess in the roots, which produces a consequent tendency of the liquids in the plant to flow upward; the total result being a flow of the liquids from soil to root, from root to stem, and through the stem to the leaf and bud. The rapidity of this ascent of sap is directly proportional to the activity in the leaves and buds, since this determines the extent to which the water is used up. In warm bright sunshine the life processes in the leaves are vigorous, the stomata open, and the sap rises rapidly. At night the current is decreased, and in winter the processes practically cease, to be revived again when the warm sun of spring makes it possible for the cells in the leaves and buds to resume their activity. It is known that the water rises chiefly in the large ducts of the fibrovascular bundles, the spiral and ringed ducts serving for this purpose. It does not flow, however, in the cavities of these ducts, but rather in their walls, passing from cell to cell within the thick, but evidently porous, walls. While these factors partly account for the rise of sap, they do not explain the actual force which lifts the water, rising as it does to the tops of the tallest trees. This is difficult to explain. It is generally thought to-day that the three forces above mentioned are sufficient for the process: (1) Osmosis: this forces the water from the soil, through the root hairs into the roots, and probably from cell to cell within the plant, up through the root and stem to the top of the plant. (2) Capillarity: this force causes liquids to rise inside of small spaces, and must play some part in the rise of water in the plant. (3) Avidity for water: the demand for water of the protoplasm at the top of the plant, above explained, is doubtless an active agent also in producing the flow of water from cell to cell up the plant. Whether these forces are sufficient to explain the ascent of sap we do not know; but at all events the plant possesses no distinct circulatory organs, and it is believed that tnese physical forces are sufficient to account for the lifting of water from the soil to the leaves and buds. Transfer of Substances Downward. — It is evident that there must be a transfer of material downward as well as an ascent of sap. As we shall presently notice, plants are engaged in making starch in their leaves, and this starch is certainly carried to all parts of the plant, since it may be stored in the underground parts. The starch in a potato, for example, is made in the leaves and hence it must be carried downward. The method by which the material is carried from the leaves downward is even less understood than the ascent of sap, although osmosis is undoubtedly one of the factors. It is known, however, that the starch is first changed to sugar and then dissolved in the liquids of the plant. It is also known that these materials then descend, not in the same cells in which sap is ascending, but in the large sieve cells of the bark (see Fig. 46) , which are the cells chiefly concerned in the downward current. Since the bark is needed for this downward passage of food, we see another reason why the cutting of the bark away from the tree for a short distance, girdling, will in time kill the plant, since the food materials made in the leaves cannot then be carried to the roots and they will die for lack of nourishment. PHOTOSYNTHESIS OR STARCH MANUFACTURE By the process just described, the water, with the dissolved minerals, is brought to the chlorophyll cells in the leaves. These same cells are also in direct contact with carbon dioxid which is in the air and is brought into the leaf through the stomata. The chlorophyll-containing cells have the wonderful power of causing the carbon dioxid obtained from the air, and the water obtained from the soil, to combine with each other chemically to form a new product. The transformation is represented by the following equation : — It must not be understood that this equation is an accurate, statement of what occurs, for we do not know the details of the building of starch from carbon dioxid. There is no doubt that the process is far more complex than is. indicated by this simple equation. The building of CO2 and H2O into starch is not done by a single step as here represented, but in all probability by several steps. Moreover, the starch molecule is by no means a simple molecule as the formula C6Hi0O5 indicates, but some multiple of this formula; how high a multiple we do not know, but probably with many times this number of atoms in the molecule. The above equation represents the ratio of the atoms but not their actual number. While the details of the method by which the complex molecule of starch is formed are not yet known to us, we do know that the essential features represented by this equation — namely, that C02 and H2O are combined, that starch is manufactured, and that oxygen is set free — are in the main correct. This process is called photosynthesis (Gr. photos = light + synthesis = composition), and it is the only known method by which starch can be manufactured, chemists having hitherto been unable to make it by any artificial means. From the above equation it will be seen that while carrying on photosynthesis, a plant is using up carbon dioxid and at the same time liberating oxygen and producing starch. The oxygen is liberated in the form of a gas which passes from the plant into the atmosphere. The liberation of oxygen may be easily demonstrated by placing some kind of green water plant in a dish of water ing eliminates oxygen gas. The plant is a green water plant, and the bubbles which arise from it and collect in the tube prove to be oxygen. and placing it in the sunlight. Minute bubbles of gas will soon make their appearance on the plant, which will rise through the water and pass off into the air. If these bubbles are collected in an inverted funnel (Fig. 67) and tested chemically, the gas proves to be oxygen. All green plants liberate oxygen when growing in sunlight, a process that is exactly the reverse of the respiration of animals, which absorb oxygen gas and liberate carbon dioxid gas. Photosynthesis is the foundation of all life, since the life of all animals as well as plants depends upon starch. Its relations to various external conditions are as follows : — Chlorophyll. — Photosynthesis is dependent upon chlorophyll and hence occurs in green plants only. Moreover, in these plants, photosynthesis occurs only in those cells that contain chlorophyll, and thus chiefly in the palisade and mesophyll cells of the leaf, although it may take place in other cells if they contain chlorophyll. Sunlight. — Photosynthesis is dependent upon sunlight and therefore never occurs in plants unless they are in the light. The vigor of the process is dependent also upon the intensity of the sunlight. It is most active in direct sunlight, less so in diffused daylight, and stops entirely when light is withdrawn. Carbon Dioxid. — Photosynthesis is dependent upon the presence of carbon dioxid. Those plants which live in the air will always have plenty of carbon dioxid, since the air contains this gas. Water plants depend upon the gas dissolved in water. The dependence of photosynthesis upon carbon dioxid can be shown if a green water plant is placed in sunlight in ordinary water, when bubbles of gas (oxygen) arise from it, showing the presence of photosynthesis. If, however, this plant be placed in a dish of boiled water which has been cooled, the bubbles do not arise from its leaves, showing that photosynthesis does not occur. Boiling the water drives off the carbon dioxid dissolved in it, and the plant, having no carbon dioxid at its command, cannot carry on photosynthesis. Temperature. — Photosynthesis is dependent upon temperature. Even though the sunlight be brilliant, if the temperature be below freezing photosynthesis cannot go on. It can, however, take place in temperatures very slightly above freezing, and will continue from this point up to moderately high temperatures. At higher temperatures, 120° to 130° F., the process stops. The temperature at which photosynthesis goes on most rapidly, the optimum temperature, varies with different plants, depending upon the structure of the plant itself. Some plants are so constructed that they can grow only at moderately low temperatures, and others only at high temperatures. In some of the arctic plants, photosynthesis, as well as all the other functions of the plant, goes on very readily when the temperature is not much above freezing, whereas in tropical plants photosynthesis does not occur unless the temperature is high. METASTASIS Photosynthesis may be spoken of as food manufacture, for the starch thus made is later utilized for the life processes of the plant. The use of this starch as food is generally spoken of under the term metastasis (Gr. meta = beyond + histanai = to place). This is too complicated a process to be described here in detail, and only a few of the main features will be briefly explained. As already stated, the plants take in through their root hairs not only water but a number of ingredients dissolved in it. Among these are nitrates, phosphates, potash, and various other substances in smaller quantities. All of these substances are carried up through the plant and distributed so that each living cell may receive some of this dissolved material. The starch, formed chiefly in the leaves, as we have seen is converted into sugar, chiefly in the night, and then transported through the plant in the sieve cells of the bark. The living cells in the various parts then take the water and minerals brought with the ascending sap, and the sugars brought from the leaves, and by changes the cell protoplasm into new substances. These new substances are of many varieties. The most important among them is the class of compounds which we have already learned to call proteids. Proteids contain chiefly the elements carbon, oxygen, hydrogen, and nitrogen, and are built out of the nitrates and other minerals absorbed from the soil, in combination with the sugars brought to them from the leaves. Proteids are not the only substances manufactured in the plant cells. Fats are produced which may be stored away in the plants or used for other purposes. Wood is also made and deposited around the protoplasm, forming the walls of the wood cells. Numerous other substances are produced which we need not mention, for the end result is the growth of all parts of the plant which increases in size as these new substances are formed. In all cases, however, the starch made by the leaves is the foundation of the new substances made. Starch is always used up and the plant can grow only so long as it has starch at hand in abundance. This process of using starch and making other substances is known as metastasis. One of the results of the use of starch for any of these purposes is a combination of part of its carbon with oxygen, forming CO2. This is a process similar to the respiration of animals, and the CC>2 is in plants, as in animals, a waste product which must be excreted. It is thus seen that plants carry on two opposite processes. By photosynthesis CO2 is utilized, starch is formed and 0 is set free; by metastasis O is used, starch is destroyed and C02 is set free. During the ordinary life of a plant in daylight, although both processes are going on simultaneously, photosynthesis is much more vigorous than metastasis, and much more starch is made by the plant than is used, so that oxygen is constantly eliminated. Photosynthesis, since it takes place only in sunlight, can occur only in the daytime, while metastasis, requiring no sunlight, can go on in the night. The process of metastasis goes on fully as well, and certain phases go on better, in the darkness than in the light. As a result, green plants in sunlight and in the daytime give off a surplus of oxygen, while in the night they are giving off carbon dioxid but no oxygen. Oxygen gas is a material that is utilized by animal life, while carbon dioxid gas is a waste product of animals as well as plants. Hence it has been said that, in the daytime plants are useful in a living room, while in the night-time they are harmful. There is really no foundation for this claim, since the amount of carbon dioxid given off by a few plants in a room is so slight that it is of no practical significance in its bearing upon animal life. In nature, however, the plant and animal life balance each other; while animals absorb the oxygen given off by plants, they themselves give off carbon dioxid that is utilized by plants; and thus the condition of the atmosphere is kept practically constant so far as concerns its content of both oxygen and carbon dioxid. In general, plants manufacture far more starch than they need for their own life. The surplus is stored in some form as starch, sugar, fat, proteid, or some other material, and upon this surplus the whole animal world is nourished. All ordinary green plants carry on this process of photosynthesis. Fungi, illustrated by bacteria, yeasts, molds, mushrooms, etc. (Figs. 32, 34, 42), all agree in lacking the green chlorophyll and are for this reason sometimes called colorless plants. Since they have no chlorophyll they are unable to carry on the process of photosynthesis, unable to utilize the energy of sunlight and manufacture starch. The Fungi are commonly found growing and feeding upon organic foods, and are quite unable to utilize the minerals of the soil and the gases of the air. They are usually found, therefore, in the midst of masses of decaying organic refuse, on dead tree trunks, in manure heaps, growing from rotting leaves, etc. They feed upon the remains of past generations of green plants, having, as we shall see later, a very important part to play in nature's food cycle. liberated and used. The forces concerned in starch making and the building of proteids and other materials are ordinary chemical and physical forces. While we cannot cause these particular chemical combinations to occur in our laboratories, and do not understand them fully, we do know enough about them to prove that they belong to the ordinary forces of chemical affinity. In starch making the atoms are combined in ordinary proportions, and there is no reason for thinking that any other factors are concerned besides those of chemical affinity. MISCELLANEOUS FUNCTIONS OF PLANT LIFE Besides the processes of photosynthesis and metastasis, the only other prominent function of plant life is reproduction. The two functions of motion and coordination, which are very prominent in animal forms, are very slightly developed among plants. Motion. — The most striking distinction ordinarily recognized between animals and plants is the absence of the power of motion in plants and its presence in animals. This distinction, however, is by no means a sharp one, for motion is not wholly lacking in plants. Many of the lower types of plants are capable of locomotion. This is confined largely to the microscopic forms, and in some plants it is present only in their reproductive spores. For example, Ulothrix (see page 93) is a motionless organism in its ordinary adult form, but produces reproductive spores, called zoospores, which swim rapidly in the Fig. 68. Among the higher plants no active type of locomotion is found, although many of them are constructed in such a way that they may be carried to and fro by motile animals. Even among the highest plants, however, a certain amount of motion is developed in the different parts of the plant. Among the flowers of the highest groups of plants, motion is developed in certain parts ot the flowers for the distribution of pollen. In most of the highest class also, careful study has shown that the leaves are constantly in a state of slow motion, waving to and fro during the growth of the plant in sunlight. Of course the leaves are almost always moved by the wind, but quite independently of air currents they have a motion of their own which can be detected by a careful recording apparatus. It is thought that this motion is due principally, perhaps entirely, to the unequal evaporation of water on different sides of the stem. At all events it is so slight that it can hardly be considered true motion, and it certainly is not locomotion. In addition to this, some plants have the peculiar property of closing their leaves in the night. The leaves droop and close themselves in such a way as to present a small surface for evaporation. This motion is sometimes spoken of as the sleep of plants. It is not developed in all, but it is more common than has generally been believed. Thus, while it is believed that plants do not as a rule possess the power of motion and, except in the lowest forms, no power of locomotion, it is not absolutely true that motion is lacking in the vegetable kingdom. Speaking in general, however, plants are characterized by absence of motility. Coordinating Functions. — Plants have nothing whatever that corresponds to a nervous system in the sense of possessing nerves or nerve fibers which coordinate the different parts of the body. There is practically no coordination between the functions carried on in the different parts of the plant. True sensory functions are also lacking from plants. In a general way the protoplasm of plants, as well as that of animals, is sensitive. All protoplasm reacts under certain stimuli and is therefore sensitive. Moreover, there are some of the higher plants which react so quickly and so strongly to certain stimuli that they are spoken of as sensitive plants. In the common so-called sensitive plant a touch upon the leaf will cause the leaf to close, and a slight touch of the branch will cause all the leaves on that branch to droop. Such a condition, however, is very unusual among plants, and in these cases it is incorrect to speak of the plants as sensitive in any proper" sense. There is no reason for thinking that the plant has any sensation, i.e., any true consciousness; and all that is meant by being sensitive in these cases is a quick ability to respond to an external stimulus. GENERAL LIFE FUNCTIONS OF ANIMALS THE life of animals is much more complicated than that of plants and the animal body is correspondingly more complex. It will make the study of multicellular animals more intelligible if at the outset we notice certain general functions of life that are exhibited by all higher animals. They are as follows: — Alimentation (Lat. alimentum = food). — The process of food getting is called alimentation. The organs concerned in it are those that take food into the body, those that digest it, and finally those that absorb it into the circulating medium. Circulation. — The process by which food and other ingredients are transported through the body is called circulation. Usually it is brought about by a circulating medium called the blood, by a series of tubes in which the blood is carried, known as blood vessels, and by a pump, or heart, designed to keep the blood in motion. In some of the smaller animals this system of organs is far simpler, neither blood vessels nor a heart being present; but some form of circulation is always found. Respiration. — The chief chemical process in the animal body is oxidation, i.e., the combination of the food with the oxygen. For this purpose, oxygen gas must be absorbed by the blood. As a result of the oxidation of the food another gas (CO2). arises, which is also taken up by the blood and must be eliminated, since it is a waste product. The function by which these two gases (O and CO2) are absorbed and discharged is called respiration. Respiration is thus a gas exchange that takes place between the body and the surrounding medium. Metabolism (Gr. meta = beyond + ballein = to throw). — The foods taken into the body are eventually combined with the oxygen taken in by respiration and as a result new products HYDRA FUSCA 139 arise, some of which are useful, while others are waste products. The result of the combination of food with oxygen is, that a certain amount of force is liberated in the same way that heat is liberated from coal when it is burned. This force varies according to the amount of activity of the animal life. The whole process of chemical change by which the food is used is called metabolism. Two distinct phases of it may be recognized : anabolism (Gr. ana = up) , the process by which complex substances are built out of simpler ones; and katabolism (Gr. kata = down), the process by which complex substances are torn down into simpler ones. In animals the latter are more extensive than the former. Excretion. — The function of getting rid of the waste products of metabolism is called excretion. These products are no longer valuable but act as a direct poison to the body if allowed to remain. These waste products are solid, liquid, or gaseous. The gases are excreted by respiration, as just described. In higher animals the liquids are carried off by the lungs, by the skin, and by special organs called kidneys. It must be remembered that excretion does not refer to the passage from the intestines of the undigested food. This undigested food has never become part of the body and its passage from the intestines is not strictly excretion. There is apt to be confusion in the use of the terms, as the undigested food which passes through the intestines frequently goes by the name of excreta. In the strict sense, however, the excreta or faeces are not excretions. tion and have special organs adapted for bringing it about. Support. — The living parts of an animal (protoplasm) are made up of a soft, jelly-like substance, too non-resistant to have the power to hold any particular shape. If the animal is small the resisting power of the jelly may be sufficient to preserve its shape; but in large animals it is necessary to have some hard support for holding the soft parts. This hard supporting substance may be in the form of a skeleton or shell. Coordination. — The numerous activities of the animal body are brought into harmonious action for a common purpose. The function by which they are related to one another is known as coordination (Lat. con = together + ordinare = to regulate), and the system of organs that produces this coordination is generally spoken of under the name of the nervous system. from the earth. The nine functions thus outlined are necessary to the life of all animals. In a few of the lower animals, some of these functions are very slightly developed; and in quite a number of smaller animals we do not find any special system of organs devoted to some of these functions. For example, many small animals have no skeleton, and some of the very simple ones have no organs that can properly be called a coordinating system, since all of the functions of the animal take place in one small cell where no coordination is needed. But speaking in general, all animals, high or low, carry on all these functions. ANIMAL BIOLOGY In our consideration of animal Biology we shall study three animals, chosen to illustrate different grades of structure. Hydra will be an example of one of the simplest multicellular animals; the earthworm, an animal of moderate complexity; and the frog will be an example of the more highly complex types. HYDRA FUSCA: A SIMPLE MULTICELLULAR ANIMAL General Description. — The brown Hydra is a very common water animal and may be found in almost any pond on the under side of lily pads or pond weeds. Here it may be seen as a small reddish body, just large enough to be visible. Our common Hydra ( Hydra fused) is of a brown color, but another common species (Hydra viridis} is bright green. If the animal, still attached to the lily leaf, be removed from the pond, placed in a dish of water and left undisturbed for a time, it will slowly expand and assume the form represented in Figure 69 A. It shows then a slender body about a quarter of an inch or less in length, attached at one end to some other solid object. At the other end it bears a crown of tentacles, which in the brown Hydra are from five to ten in number, and in the green Hydra are from five to twelve. These tentacles are very delicate, hairlike bodies, which may be expanded to considerable length, as at A, but when contracted, shrink into minute knobs hardly big enough to be seen. Indeed, the whole body of the Hydra is extremely contractile, and though when undisturbed it may be a half an inch or more in length, on being disturbed it will contract into a small body no larger than a pinhead; see Fig. 69 B. Hydra seems at first to be a stationary animal, although it can move its tentacles slowly to and fro in the water. A careful examination, however, shows that it has some power of motion; the animal, creeping by means of its base, can move slowly over the object upon which it is fastened. Occasionally also it moves by turning end over end. It first attaches its tentacles to the object to which its base is attached. Then the base lets go its hold and is moved over and fastened again in another spot. The tentacles let go their hold and the animal straightens up. The movement is not unlike that of a boy turning a handspring. Structure. — In the midst of the crown of tentacles is a little conical projection, on the top of which is a mouth. This is star-shaped rather 'than circular, and opens into a cavity which fills the whole of the body of the Hydra and even extends into its tentacles. This cavity is the digestive cavity and is called the gastrovascular cavity; see Fig. C. Hydra is a true multicellular animal, made up of many thousands of cells which are not alike but show a considerable differentiation and have a division of labor among them. All of these cells, however, are arranged into two layers, one on the outside called the ectoderm (Gr. ectos = outside + derma = skin), ec A, an animal in its expanded form; B, the same animal contracted; C, a diagram of the longitudinal section of the animal, showing the internal structure; D, an epithelio-muscle cell; E, a bit of the body wall highly magnified showing the two layers of the body; F, a digestive cell; G, one of the nematocysts with its thread extruded; H, a second type of nematocyst with the coiled thread within the sac; /, nematocyst of the third type with its thread extruded; J, a bit of the tentacle, very highly magnified, showing the batteries of the nematocysts; K, two of the secreting cells of the basal disk. (Fig. C), and one on the inside called the endoderm (Gr, endon = inside), en. These two layers are found throughout the body, both the ectoderm and endoderm extending into the tentacles to their very tips. Hydra is thus a double sac with no space between its two layers. The layers of ectoderm and endoderm are not in actual contact with each other, but areseparated by a thin supporting layer known as a mesogloea (Gr. mesos = middle + gloia = glue), mes. By means of this intermediate layer, the ectoderm and endoderm are very firmly attached to form one solid mass, forming a body wall made up of two layers of cells. Ectoderm. — The ectoderm is made of two chief kinds of cells. The first of these is the epithelio-muscle cells; Fig. D. These are in the shape of cones, with their broad ends outward and their tapering ends toward the mesoglcea. At the tapering ends some long fibers protrude which extend over the body of the animal next to the mesogloea. The great contractility of Hydra is due to these fibers. The second type of cells is the interstitial (Lat. inter = between + sistere = to stand) cells. These are found between the first cells and are somewhat smaller than the epithelio-muscle cells. They are chiefly interesting because they produce a very peculiar type of organ possessed by Hydra known as the nematocysts (Gr. nema = thread + cystis = sac) . The nematocysts, or stinging cells, are little sacs scattered all over the outside of the body of the animal, especially in the tentacles. Each of these is an oval sac, one side of which is pushed inward like the finger of a glove inverted into its palm; Figs. G, H} and 7. This inverted portion is in the form of a long thread, much longer than the diameter of the sac, and is wound up in a long coil inside of it; Fig. H. Besides this thread the sac contains a liquid. The peculiarity of these cells is that under a proper stimulus the minute thread may be inverted from the sac as shown in Figure G. This inverted portion when discharged carries with it a small quantity of poison, and thus each thread serves as a little poison dart. The thread is not shot away from the animal, but only protruded to its length. If any small animal with thin skin comes in contact with the Hydra, some of these threads are discharged, the animal is hit by them, paralyzed by the poison, and then transferred to the Hydra's mouth by means of its tentacles. In Hydra these cells are so small that they cannot pierce the human skin and their sting cannot be felt; in some allied animals, like the jellyfishes or sea nettles, these cells, although the same in structure as those of the Hydra, are much larger and may produce a severe sting. After the thread is once discharged, it cannot be withdrawn again into its sac; the cell thus becomes useless. It is necessary, therefore, for Hydra to be constantly replacing them, and new nematocysts are constantly growing from the old interstitial cells. The special cell that produces the nematocyst is known as the cnidoblast. This is simply one of the interstitial cells which has for its function the production of these stinging sacs. In the brown Hydra there are three kinds of nematocysts. The larger one, G, is somewhat pear-shaped, and when its thread is protruded it has, close to the base of the thread, two or three slender barbs projecting backwards. When the thread is discharged from the cell these barbs are ejected first. It is thought that their function is to pierce the skin of the animal into which the poison is to be ejected. Close to the base of the thread is a minute little organ called the cnidocil (Gr. cnide = thistle) whose function is unknown ; Fig. G, en. It has been supposed that it helps to discharge the cell as a trigger does a gun. This is doubtful, for it is known that the cell is most easily discharged by changing the internal pressure, rather than by any mechanical touch upon this cnidocil. The second of the nematocysts in the Hydra, H, is smaller but more elongated. The thread when discharged is very different in shape, lacks the projecting barb, and, relative to the size of the sac, is much longer. The third cell is smaller still, I, oval in shape, and contains a thread that when discharged always coils up in a spiral form. It is thought corkscrew fashion. The nematocysts are scattered all over the body of Hydra except in its base. In some parts, especially in the tentacles, they are grouped into little bunches which project from the side and form tubercles; Fig. J. These little clusters are spoken of as batteries. The Basal Disk. — The base of Hydra is different from the rest of the body. It secretes a sticky substance by means of which the animal attaches itself to an object. This base has the power of causing the animal to glide very slowly over the object upon which it is attached, though the exact method by which this motion is produced is not known. In this part of the body the nematocysts are lacking, and the epithelio-muscle cells not only have muscle fibers but some of them have the function of secreting a cement, and differ in appearance from those of the rest of the body; Fig. K. Endoderm. — The endoderm is about twice as thick as the ectoderm and contains cells of two kinds, known as the digestive cells and the secretory cells. The digestive cells are long and cup-shaped, and have, extending from their base next to the mesoglcea, fibers of contractile substance. At their inner or free end they bear two lashing flagella; Fig. F. It is interesting to note that the free end of these cells may be protruded in the form of pseudopodia, much like those already seen in the Amoeba, and that they are able to take into their bodies small solid particles of food which are then probably digested within the cells of the body itself. Thus Hydra has a function of digestion similar to that of the Amoeba, being able, to a certain extent, to take inside of its digesting cells solid particles of food and to digest them (intracellular digestion). The chief digestion, however, is carried on by the other cells, the secretory cells. These are smaller than the digestive cells and lack the contractile fibers at their base. They produce a secretion which is discharged from their free surface into the cavity of the body, and is thus poured upon the food which is taken into the mouth and lies free in the gastrovascular cavity (intercellular digestion). Hydra has thus, in addition to a method of digestion which resembles that of the Amoeba, the power of producing a digestive secretion, which is poured upon the food in the general cavity, only the nutritious portions of the food being absorbed after digestion. This method of digestion, which is peculiar to the higher animals, is, in the Hydra, combined with the simple method of digestion characteristic of the PROTOZOA; and in this respect the Hydra represents a transition stage between the unicellular animals and the higher, multicellular forms. The function of the hairlike flagella on the endodermal cells apparently is to keep in circulation the liquids present in the body and thus to aid in bringing the digestive juices in contact with the food which lies in the cavity. This is the only trace of a circulatory system that the Hydra possesses. Nervous System. — According to recent investigation, it seems that Hydra possesses a very simple nervous system, so delicate, however, that it requires special methods of study; and very little is known about it. There is a series of nerve cells near the mouth and another near the base of the animal, and these are connected with excessively delicate fibers passing over the body. There are sensory cells on the surface layer that are probably connected with the nerve cells, and some of the nerve cells apparently send nerve fibers to the contractile fibers of the epithelio-muscle cells. This system is, however, very simple and rudimentary, and is of interest chiefly as the simplest type of nervous system found among animals. Growth and Budding.— The food of Hydra consists mainly of minute water animals which are captured by means of its tentacles. The tentacles are protruded into water, and small animals, coming in contact with them, are paralyzed by the discharge of the nematocysts. The tentacles then transfer the food to the mouth. It is pushed into the gastrovascular cavity and then, by the contraction of the body wall, forced downward to the basal end of the cavity. Here it is mixed with the digestive juices of the animals and slowly digested. In time the digestive parts are dissolved and absorbed into the cells that form the body wall and are assimilated. After all the nutritious portions have been digested and absorbed from the food particles, the undigested refuse is then ejected from the mouth by a sudden contraction of the body and opening of the mouth, which throws the ejected portions some distance from the animal. As the result of digestion and assimilation, the animal grows. After it reaches a certain size, rarely more than one-half an inch in length, the further growth shows itself in the formation of buds which appear on the sides of the old individual; see Fig. A. These buds rapidly increase in length, and after a time a circle of minute secondary buds can be seen at their tips. These secondary buds are rudimentary tentacles, for they increase in length till eventually they become new tentacles. In the middle of the circle of tentacles thus formed a small opening makes its appearance, which forms a new mouth at the end of the growing bud. After a time the bud itself separates from the body of the animal from which it grew and floats off by itself as an independent individual, identical in structure with the one from which it came, though somewhat smaller. In this way the Hydra reproduces itself indefinitely by budding (gemmation) as long as it has sufficient food and proper conditions for feeding and growth. If the conditions are favorable two or more buds may be seen arising from the same individual, and occasionally a secondary bud may be found arising from the side of the bud, even before it has broken away from the animal that produced it. In the case of the Hydra, however, these buds do not remain attached very long, but always separate; so that we never find the animals grouped together in great masses. While we may find one Hydra with one, two, or three buds, this is the extent of group formation. In closely allied animals, however, the budding may go on almost indefinitely, and groups are formed containing hundreds of members, all having arisen from the original by budding. This occurs among the hydroids which are common at the seashore, examples of which are shown in Figures 70, 72, and 73. In such colonies the individual members are called zooids. Polymorphism. — In the colonies of hydroids shown in Figure 71 the members of the colony are all alike. It not infrequently happens, however, that when one of these hydroids WHICH FORMS COLONIES The individual members, which have arisen by budding, are imbedded in a lime base; p, one of the members of the colony more highly magnified. forms unlike each other. In Figure 72 will be seen a colony with two types of members; one of them possessing tentacles and adapted for feeding, and the other without tentacles but developing the reproductive bodies inside of a case. One of these members is known as the nutritive zooid, nz, and the other as the generative zooid, gz. In some other types of hydroids the members which arise by budding assume even a greater variety of form. In the colony shown in Figure 73 there is a complicated colony made up of at least five different types of members or zooids. Among them may be found members adapted to feeding, n; others having purely sensory functions, called tentacular zooids, t; some adapted for reproduction, g; others in the form of bells with muscles which enable them to move about, called the swimming zooids, sw; and A colony of Hydroids showing a differentiation into feeding zooids, nz, and generative zooids, gz; e, e, eggs in different stages of development; e' the young embryo extruded into the water. An animal showing a high condition of polymorphism; /, the floating zooid; g, the generative zooid ; n.the nutritive zooid; sw, the swimming zooid; t, the tentacular zooid. a single one develops as a gas bladder, /, which enables the animal to float in the water. All of these combine to form a colony. Where several different types are found arising by budcfeng from the same original stock the condition is spoken of as polymorphism (Gr. polus = many + morphe = form). Polymorphism is best illustrated in simple organisms, being well developed among the animals related to the Hydra; but the samp principle is found in a less developed extent in some of the organisms with a higher structure, though nowhere do we find it so highly developed as among the hydroids. Where polymorphism is developed the whole colony acts as a unit, and the colony, therefore, may be compared to a more highly complex organism with its various organs. Polymorphism always arises as the result of asexual growth and not by sexual reproduction, and when it occurs the members of the colony always show a differentiation in function as well as in shape and structure. Regeneration of Lost Parts. — Hydra has a wonderful power of reproducing lost parts. If it is cut into two pieces, each part will develop the part that it has lost and becomes a new Hydra. Indeed, it may be cut into a large number of fragments, and every fragment is capable of growing and developing into a new form like that of which it was originally a part. If the small conical projection containing the tentacles is cut off from the rest of the Hydra, each piece will develop the part that it has lost. The animal may be split lengthwise into two or four parts and each will become a perfect animal. If a head is split in two and the parts slightly separated, each will develop its crown of tentacles and a two-headed animal will result. If an animal is turned wrong side out, it will adjust itself to new conditions and a perfect animal will soon be produced. This power of regenerating lost parts is found in many of the lower animals, but in no place is it better developed than in Hydra. In the higher animal the power of regenerating lost parts eventually disappears entirely. It is very evident that this power must be of considerable advantage to the animal in the struggle for existence. In Hydra the power is so extraordinarily developed that a piece of the animal not more than one-hundredth of an inch in length is capable of reproducing all of the parts that are lacking and developing into a new animal. In some cases the new animal is produced by a multiplication of cells from these pieces, so that a fair-sized animal is developed; while in other cases the cells and fragments are remolded into new icdividuals which are like the original in shape but much smaller in size. Some of the experiments described were originally performed long ago, by Trembley in 1740 ; but they have since been confirmed by other investigators. Sexual Reproduction. — By the method of budding Hydra may multiply indefinitely as long as it has plenty of food. Under certain, not well-understood, conditions the animal produces outgrowths on its side, shown in Figure 69 C, which are the sexual glands, — ovaries, o, and spermaries, s. Within them are produced special cells, called eggs and sperms, which unite with each other in a manner similar to that seen in the cells of Pandorina (page 74). The significance of this reproduction will be noticed in a later chapter. Hydra, as will be seen from the above description, possesses the systems of alimentation, metabolism, motion, and reproduction. Circulation is wanting; respiration is carried on through the general surface of the cells; no excretory system is found, each cell probably excreting its waste products directly into the water; support is unnecessary in such a small animal; the rudiments of nerves suggest the beginning of a coordinating system. ENT PARTS With the appearance of multicellular organisms we also find that the entire animal has -now a life more or less independent of the life of its parts. The multicellular animal or plant lives a life as a complex, and in addition each cell has a life of its own; so that we can distinguish, in a multicellular animal, a life of the organism as a whole and a life of its separate cells. It is possible for the death of the organism as a complex to occur while the individual cells still remain alive. It is true that in the multicellular organism each of the individual cells is dependent upon the activity of the whole to keep it properly nourished and supplied with the necessary conditions of its life. The different cells that make up such organisms are not independent and cannot live long except when related to the other cells that make up the multicellular organism. Nevertheless, there is a certain amount of independence in the individual cells, especially among plants and some of the lowest animals; for in these we may remove only a comparatively small number of cells from the whole organism and these cells will still retain their vitality, still continue their power of growth, and under proper circumstances develop more cells which eventually become exactly like the animal from which they were obtained. This is especially true of Hydra, which can be cut into many pieces, each piece retaining the power of independent life, and in time becoming an independent and well-developed animal. In such low organisms the life of the organism as a complex has not wholly destroyed the independence of the individual parts. This is more or less true throughout the whole of the plant kingdom. Among most higher plants as well as the lower, small pieces separated from the parent plant will not die at once, but may, if put under proper conditions, develop into fully grown individuals like those from which the fragments were obtained. With animals, however, it is only among the lowest and simplest forms that a piece, containing a relatively small number of cells, can be separated from the rest and still be capable of developing into a new organism like the original, as in the case of the Hydra. As we pass to the higher animals this power of regeneration disappears, and among almost all animals, even of comparatively low structure, the independent life of the parts is lost, so that when one portion is removed from the complex that makes up the animal it no longer retains its power of life and growth. But even in these cases and among the highest animals, we do find that some parts may have more or less independent life when separated from the organism of which they are a part. In an animal like a frog, for example, the heart may be totally removed from the body and it will still keep up its life for many hours when put under proper condi- tions, long after the frog itself has been killed. More remarkable is this power in the case of a turtle, for here even when the animal has its head entirely cut from the body, and the rest of the animal destroyed, the heart, if removed and kept under proper conditions, will keep on beating for at least two days. Still more remarkable is it to find that in the air passages of the turtle there are ciliated cells which have a special power of motion ; Fig. 14 C. During all the life of the turtle these cilia are in a state of active motion, and after the turtle is dead the cilia may continue moving for as long as two weeks. We thus see that among the higher organisms the death of the animal as a whole does not necessarily involve an immediate death of all its parts. The individual parts are, of course, closely dependent upon each other, and, at least in the higher organisms, the life of neither is capable of being long maintained without the other; but the life of the individual cell may frequently continue some time after the life of the organism as a whole has been brought to an end. From this it follows that the term death may have a different meaning in different connections. In speaking of the death of an animal, we may refer, and usually do refer, to the death of the animal as a whole, which means the destruction of the complicated mechanism that forms the animal organism. But we may also refer to the death of the individual parts, and in this case the exact time when the animal comes to its death is difficult to state. The animal as a whole may die on one day, while some of its parts may remain alive at least two weeks. In such instances it is not easy to say when death occurs. Nevertheless, it is customary to refer by this term, not to the death of the individual parts or the individual cells which make up the animal, but to the destruction of the organism as a whole, which causes it to cease to act as a unit. Usually, therefore, death refers to the breaking down of the mechanism of which an organism is composed so that its parts do not act together. Hydra. — Almost any pond will furnish Hydra, which may be found clinging to the under side of pond-lily leaves. If such leaves are placed in a dish of clean water, the Hydra will detach themselves from the leaves and cling to the side of the dish. For study, a specimen is to be detached from the dish, placed in a watch glass containing a little water, and examined under the microscope with a low-power objective. The general structure and motion of the animals may easily be seen. For the cellular structure of the body, stained, mounted sections should be furnished the student by the instructor. For a study of the nematocysts, a bit of the tentacles of a brown Hydra should be cut off with delicate scissors and placed on a slide in a small drop of water. A cover glass is placed upon the drop and gently pressed. This will crush the tentacle and cause many of the nematocysts to discharge their stinging hairs. The nematocysts may also be made to discharge their stinging hairs if a little weak acetic acid is added .to the water. A careful examination with a \|-inch objective will show all three kinds of nematocysts, both discharged and undischarged. For comparison of Hydra with other Hydroids, preserved and mounted specimens should be furnished by the instructor, some of which should show colonies and others jellyfishes. THE earthworm is an extremely common animal the world over, being found buried in moist earth in practically all parts of the world. There are numerous species, differing from each other in minor details, but agreeing in their fundamental structure. The animals vary in size from those an inch or two in length, to some which are nearly a foot; and one species is reported two feet in length. Earthworms are of practical importance in stirring up the soil. They are constantly engaged in bringing soil from below to the surface, and depositing it at the mouths of their burrows. By this slow but constant action they are of much value to agriculture, constantly renewing the surface soil. ANATOMY Shape of Body. — Examined externally, the earthworm is an elongated animal, more or less cylindrical in shape, tapering, however, at the two ends; Fig. 74. The head, or anterior end, is more tapering than the other, the blunter one being the posterior end. One side of the animal is lighter colored than the other and slightly flattened, the opposite side being more rounded. When the animal is in its natural position on the surface of the ground, the flat side is kept undermost and the rounded and darker-colored side uppermost. We thus have an anterior and a posterior end, a ventral and a dorsal surface, and, consequently, a right and left side to the animals. The animal is, therefore, bilaterally symmetrical. Segments or Metameres. — The body of the earthworm is divided into a number of rings (Fig. 74) called segments or metameres (Gr. meta =• after -f meros = part). The number is not constant, being greater in the older and larger animals than in the younger ones, and increasing with age. Most of these rings are alike in shape and size, but a few of them differ slightly from the others. The first one at the anterior end is not a complete ring, but a minute projection which is known as the prostomium (Gr. pro = before + stoma = mouth). It is slightly movable and is the most sensitive part of the animal. The second segment is not a complete ring, but rather in the form of a horseshoe, with the open part of the horseshoe above, the segments are all alike in shape, increasing slightly in size until a maximum is reached, and from this point remaining essentially the same in size and shape to the posterior end of the body. A short distance back from the head there is a series of rings, from the twenty-eighth THE EARTHWORM to the thirty-fifth segments, known as the clitellum (Lat. clitellce = saddle) ; Fig. 74. These segments are larger than elsewhere and have a thicker wall and special functions. At the extreme posterior end the segments become smaller, and the last one has an opening which is the posterior opening of the digestive tract, the vent or anus, a. Because of this ringed structure the earthworm belongs to a class of animals called Annulata (Gr. annulus = ring). Structure of the Body. — The body of the earthworm can be compared to a tube within a tube; Fig. 76. The outer tube is called the body wall, 6, and the inner tube the alimentary canal or the digestive tract. Between the body wall and the digestive system is a space filled with a liquid, this space being a true body cavity or coelom (Gr. koilos = hollow), c, differing thus from Hydra, that has no coelom. The body cavity is not, however, an open space extending from the anterior to the posterior end, but is divided by partitions into a series of chambers, with a chamber for each segment. The partitions are called septa (sometimes called dissepiments) . There are minute openings through each septum, so that the liquid that fills the body cavity may pass through; thus the different chambers are in communication with each other. The Alimentary Canal. — The alimentary canal (enteron) is a straight tube extending from one end of the animal to the other, without any convolutions. It does, however, show several distinct regions. The mouth opens into a slightly swollen section known as the throat or pharynx, ph. The pharyngeal walls are muscular, with a radiating series of muscles that pass outward to be attached to the body wall, mu. The contraction of these muscles will cause an expansion of the pharynx and convert it into a sucking organ by means of which the animal draws food into its mouth. Behind the pharynx the canal contracts into a straight gullet or oesophagus, oe, which continues back to the fifteenth segment. Here it enlarges into a thin-walled crop, cr, which is followed in the fifteenth and seventeenth segments by a second enlargement with thicker walls, called the gizzard, g. Beyond this the intestine extends in a straight line to the anal aperture or vent. The intestine is not a simple cylindrical tube but has its dorsal side folded inward to form a longitudinal ridge known as the typhlosole (Gr. typhlos = blind + solen = tube), ty (Fig. 81), whose purpose seems to be only to increase the amount of interior surface within the intestine. parts, the blood system and the codomic fluid. The blood system. — A series of tubes or vessels containing blood comprises the circulatory system. The blood of the earthworm is red, a very unusual condition among lower animals. The red color is due to a substance called haemoglobin (Gr. haima = blood + Lat. globus = globe), which is dissolved in the liquid part of the blood, and is not contained in the corpuscles, as it is in the frog and higher animals. This blood is kept in constant motion in the vessels, forced along by their contractions. The chief vessels and the direction of the blood current are shown in Figure 77 and they are as follows: — These muscles produce waves of contraction, which, arising at the posterior end, force the blood forward. In the posterior half of the body small branches pass from this tube into the intestine, ei, supplying its walls, and the blood then enters a rather large vessel in the typhlosole, from which it passes back by short tubes, ai, into the dorsal vessel. The greater part of the blood in the dorsal vessel flows forward to the segments 6-11, where five large circular vessels arise from it, ht, which pass around the sides of the body to enter a subintestinal vessel, w, also extending lengthwise and lying be- vv, ventral vessel. neath the intestine. These circular vessels are called hearts, since they contract, and force the blood downward into the ventral vessel. When reaching the ventral vessel, part of the blood flows forward, in front of the hearts, and part of it backward. From this ventral vessel branches arise which pass out into the body wall and into other organs supplying the body generally with blood. After passing through the organs of the body wall, etc., the blood is collected into another set of vessels which pass into a third longitudinal vessel lying under the nerve chord, the subneural (Gr. neuron = nerve), snv Through this it flows toward the posterior end. In the intestinal region there arises from the subneural vessel, in each segment, a circular vessel, cv, which passes up around the body to empty into the dorsal vessel, dv, thus bringing the blood back again into the dorsal vessel. There are numerous other small vessels, some of which are shown in Figure 77, but the chief ones are those that have been described. The blood is forced onward by the contraction of the walls of the dorsal vessel and the hearts, which are provided with valves preventing any back flow when the contractions occur. The course of the blood is rather indefinite and the pure and impure blood are not distinctly separated from each other, as in higher animals. There are no true arteries or veins, and no true hearts. This blood is associated With respiration, and also carries nourishment from the absorbing organs in the intestine to the active tissues, and carries waste products from the active cells to the excreting organs. Coelomic or Perivisceral Fluid. — The chambers of the body cavity are filled with a fluid called the ccelomic or perivisceral (Gr. peri = around -fLat. viscera = internal organs) fluid, which serves also as a circulatory medium. The food that is absorbed makes its way into the body cavity and is partly absorbed by this fluid. This liquid is forced irregularly backward and forward through the cavity of the body by the motions of the animal, and the nutritious parts of the food which are dissolved in it are thus directly carried to and fro and brought in contact with the living tissues of the body, that are bathed in this liquid. There is no distinct circulation of this fluid, and it cannot properlybe called a circulatoryfluid. It does, however, have some of the functions of the blood, since it carries to and fro a part of the material absorbed from the digestive tract. It corresponds more closely to the lymph of higher animals. Respiration. — The earthworm has no distinct respiratory system, but the blood vessels in their circulation in the skin are brought into a very close proximity with the air. Gases are readily exchanged through the thin skin, and respiration is carried on easily without any special respiratory organs except the minute blood vessels that lie beneath the skin. Excretory System. — Most of the excreted matter (with the exception of gases) is passed to the exterior by a series of tubes known as nephridia (Gr. nephros = kidney), one pair in each segment. Each of them (see Fig. 78) consists of a long tube, which begins in a segment of the body cavity as a minute funnel-shaped opening, i, and then passes through the septa, s, to the segment immediately behind. In the posterior segment, the tube is coiled back and forth in three distinct loops that differ in structure and function. Eventually the distal end passes through the walls of the body to the exterior, by a lateral opening, e, in each with cilia, and some of the coils are also lined with cilia. The movements of these cilia produce currents in the liquid in the tube and force the liquids through the tube to the exterior. As a further result of the action of these cilia, solid particles of waste material, which may be floating in the ccelomic fluid, are forced into the tube and then through the tube, passing through its coils and finally reaching the exterior through its opening. The coiled walls of the tube are made up of thick active cells which are well supplied with blood vessels. These are secreting cells and resemble gland cells. They have the power of extracting waste products from the blood and excreting them into the tube which they surround. The materials enter the duct of this nephridium and are slowly forced along by the ciliary current, and finally carried to the exterior. These nephridia have as their primary function the removing from the body of the waste products containing nitrogen, related to urea. Their function is thus similar to that of the kidneys of the higher animals, and indeed their structure is not unlike the kidneys of some of the vertebrates. various regions of the body. The central system. — 1. The cerebral ganglia. These are two nerve knots or ganglia, sometimes called the brain, united together and lying above the pharynx in the anterior part of the body cavity; Fig. 79 eg. From them, extending downward and backward, a pair of cords or commissures (Lat. committere — to join together), com, pass around the pharynx and unite with each other below on the ventral side of the pharynx a short distance behind the mouth. 2. The ventral cord. When the two commissures have united they form a cord which passes to the posterior end in the median line of the body, closely attached to the body wall beneath the intestines; this is the ventral cord, v. In each segment the cord is slightly enlarged to form what is called a ganglion; see Fig. 80 vc. At the posterior end of the body this cord becomes smaller and finally terminates. The peripheral system. — The nerves which form the peripheral system are numerous. From the cerebral ganglion two large nerves arise, which soon divide into many branches and pass forward to the prostomium, giving it a very large nerve supply and making it a very sensitive organ; Fig. 79. From the commissures extending around the oesophagus arise the nerves that supply the second and third segments of the body. From the ventral cord in each of the segments, from the fourth to the posterior end of the body, there arise three pairs of nerves. Two pairs arise from the ganglionic enlargement and one pair from the sides of the ventral cord behind the septum that separates each segment from the next. Reproductive System. — The only method of reproduction in the earthworm is by sexual process. The two sexes are, however, combined in the same individual, so that the earthworm is what is called an hermaphrodite; see page 251. Female reproductive organs. — In the thirteenth segment there is a pair of small glands called ovaries, situated on the ventral side of the body cavity close to the middle line; Fig. 80 ov. In the same segment is the opening of a funnel which leads into a short tube passing through the septa into the next posterior segment. Here it is slightly enlarged to form an egg sac, and from the sac a small duct extends through the body wall to the exterior, opening upon the ventral surface of the fourteenth segment. These ducts are the oviducts, od, and through them the eggs produced by the ovary pass to the seen in Figure 74. Male reproductive organs. — In the tenth and eleventh segments there is a pair of glands, the spermaries, sp, in which are formed the male reproductive elements. In these two segments their position corresponds to the position of the ovary in the thirteenth segment. They are very small glands and can only be seen by microscopic examination. Behind each FIG. 80. — DIAGRAM SHOWING THE REPRODUCTIVE SYSTEM OF THE EARTHWORM The numbers represent the number of segments, seminal receptacle vd, vasdeferens. down); Fig. 80 vd. In the ninth, tenth, and eleventh segments are large sacs known as seminal vesicles, sv, which serve as a storehouse for the secretion of the sperm glands, before these secretions pass to the exterior through the vas def- erens. At the junction between the ninth and tenth, and between the tenth and eleventh segments, may be found two pairs of white sacs, each opening to the exterior by an opening at the junction line between the segments. These are the seminal receptacles, sr, and their function is to receive the secretions from the seminal glands in copulation. Copulation and Egg Laying. — Although the earthworm is an animal producing both male and female elements in the same individual, the habits of the animal are such that there is no fertilization of the egg by the sperm of the same individual that produces the egg, but a cross fertilization always occurs between two individuals. At the breeding season, which is early in the summer, two individuals place themselves side by side with their heads in opposite directions, and by means of the secretions from the glands in their skin there is formed a slimy covering that holds the two individuals in close contact (copulation). In this position, each transfers sperm material (see Chapter XII) from its sperm glands into the seminal receptacles of the other, after which they separate. During copulation, or immediately afterwards, a secretion is produced by the clitellum, which forms a band around the animal that extends from the twenty-eighth to the thirty-fifth segment of the body. At the close of copulation, after the animals have separated, this band is gradually pushed forward until it finally slips off over the head. As the band passes forward over the fourteenth segment a certain number of eggs are extruded into it from the oviduct; and when it passes over the ninth and tenth segments some of the sperm material from the seminal receptacles is also ejected into it. As it passes off over the head it closes up by its own elasticity. Inside of this band the eggs of each individual are thus mixed with the sperm from the other individual and cross fertilization occurs. This case holding the eggs and sperms is now known as a cocoon, and within it the eggs develop into earthworms. The cocoons are deposited in the soil and may be found early in the summer. MICROSCOPIC ANATOMY OR HISTOLOGY The body of the earthworm is made of large numbers of cells of great variety in form and structure. The cellular structure in some of the organs of the body can readily be made out under the microscope, but in others the cells can be seen only by special methods. The most important features of the histology are as follows: — perforated, however, by numerous openings through which the various secretions pass. Inside of the cuticle is a somewhat thicker layer of cells mainly cylindrical in form, known as the epidermis, ep. Some of the cells are sensory cells; others have the power of secreting a slimy material which keeps the surface of the animal moist, and these are called gland cells; Fig. 82. Under the epidermis is a layer of circular muscles, cm, extending around the body, each muscle in the form of a very long, slender fiber, tapering at both ends. Extending around the bodj* as they do in a circular direction, their contraction will tend to constrict the body and reduce its diameter. Under this is a thicker layer of muscles, running lengthwise, the longitudinal muscles, Im. These are arranged in bundles and in a cross section they appear to radiate like a feather, but each longitudinal muscle fiber has the same structure as the circular muscles. By their contraction the animal's body is shortened. Under the longitudinal muscles is an extremely delicate layer of flat cells forming a thin membrane bound- Eight delicate bristles, called setae, extend through the muscle layers of the body wall and protrude through the skin, Fig. 81 s. They are arranged in four groups, two in each segment, and are attached by several minute muscles on the inner end. By means of these the setae may be slightly extruded, or moved to and fro so that the tips may be directed forward and backward. If the earthworm is pulled gently through the fingers, the projecting setae may be felt as a slight roughness on the skin. simple and crude, consisting only of the two layers of muscles, longitudinal and circular, and the seta. The method of its action is as follows: By the contraction of the circular muscles the diameter of the body is reduced, and, inasmuch as the body cavity is filled with the perivisceral liquid, and liquids are incompressible, the contraction of the diameter of the body must necessarily increase its length. The ends are thus pushed apart; but the setae pointed backward act as anchors, and the pushing of the two ends of the body apart will tend to push the head forward, the rest of the body remaining practically stationary. After the contraction of the circular muscles the longitudinal muscles are contracted, thus shortening the length of the body and at the same time increasing its diameter. As the body shortens, the tail is pulled forward toward the head, the setae again serving as anchors to prevent the body from moving in the wrong direction. Thus by alternately contracting the circular and longitudinal muscles, the head is pushed forward and the tail is pulled up to the head. If the earthworm wishes to move backward, it needs only to contract the muscles connected with the setae and to point them forward, when they will serve as anchors to prevent the body from being pushed forward; and the alternate contraction of the two layers of muscles will make the animal move backwards. This alternate contraction of the muscles does not occur the whole length of the body at once, but sections -may contract or relax, causing waves of contraction to extend from one end of the animal to the other. This method of locomotion is very inefficient for an animal living on a flat surface, and the earthworm is only able to move slowly upon the ground. In his underground burrows, however, where the animal nearly fills up the burrow, the method of locomotion is much more efficient and enables the animal to move with considerable rapidity. Alimentary System. — As shown in Figure 83, the alimentary canal consists of five layers. On the very inside next to the cavity of the intestine is a layer of epithelial cells (Gr. epi = upon + thele = nipple), ep, which secrete the digestive fluids and also aid in the absorption of the food. Just outside of these is a layer of blood vessels, v. A third layer consists of circular muscle fibers extending around the intestine, cm, and outside of this is a layer of longitudinal muscles, Im. A fifth layer on the outside consists of a thick coat of cells known as chlorogogen cells, c. These cover the intestine with a thick layer on its outer surface and also form the substance of the typhlosole, which, as pairs of white bodies known as calciferous glands (Lat. calx = lime -\-ferre = to bear), producing a lime secretion which is poured into the intestine. Its function is probably to reduce the acidity of the food, although very little is known about these glands or their uses. The Nervous System. — The microscopic study of the nervous system of the earthworm, as well as of all higher animals, has shown that while there are several kinds of cells in ijb, the chief ones, and probably the only ones possessing nervous functions, are large cells called neurons. Neurons. — A single neuron of the earthworm is shown in Figure 84 A. It has a rather irregular rounded body, with a prominent nucleus, and from it arises a long process, much longer than appears in the figure. Side branches of this proc- ess may be seen near the cell body. Other much shorter processes arise also from the cell body and divide quickly into branches. The long fiber is called the axon or the nerve fiber, and the other branching projections are called dendrites (Gr. dendron = tree). Sometimes the axons at their outer or peripheral end break up into numerous branches known as through the axon. Similar neurons make up the nervous system of all animals which have been carefully studied. In shape the neurons are quite varied (Fig. 85), but in all cases there is a cell body with one or more branching processes arising from it; and an axon fiber of varying length extends outward from the cell. Vast numbers of these neurons are aggregated together to make the nervous system of the earthworm. The cerebral gan-. glia contain them in great numbers, and the many nerves shown in Figure 79 are formed chiefly of bundles of the axons of the neurons, whose cell bodies are either in the ganglia or at the The relation of these neurons to the body may be seen from Figure 84. Most of the cells which appear so prominently in the cord have connections as shown at mn. Each has a complex of dendrites which branch in, the substance of the cord, and a single axon which passes out through the nerve to be finally distributed to the muscles. These neurons send impulses to the muscles and are called motor cells. Some send their axons to muscles on the same side, as shown in the figure, and others send theirs across the cord to the muscles on the other side of the body. These axons are known as efferent (Lat. ex = out + ferre — to bear) nerve fibers. Some of the axons do not pass out of the cord, but simply connect different parts of the cord itself. The neurons which carry impulses from without toward the center are called afferent (Lat. ad = to + ferre = to bear) neurons. These never have their neuron bodies within the cord but somewhere outside it. Many of them take their origin in special cells called sense cells (Fig. 84 so), which are sensitive to certain external stimuli. The impulses excited in the cell pass over the axon to the ventral cord. Where the axon enters the cord it breaks up into numerous branches, or arborizations, arb, which spread out in the cord itself. The impulses entering by the axons may pass from the arborizations to the dendrites of the motor cells and excite them to action. Hence a stimulus applied to the skin may produce a movement. The sense organs. — The cells at the end of the afferent nerves constitute the sense organs, and they are so constructed as to be influenced by different external forces. The earthworm has no eyes, although some of its sense organs appear to be slightly affected by a bright light. They have no ears and no sense of sound, though they are very sensitive to a slight jar. They have a sense of taste, located in the mouth, and also a sense of smell. None of the sense organs is visible to the naked eye, but they may be seen by microscopic study. The end of the Only large specimens should be used. These can be purchased from dealers in natural history supplies or they may be collected by searching with a lantern on a dark night, when they may be found stretched out on the ground and thus readily collected. A little care and experience is needed to do this without disturbing them, for they are very sensitive to the slightest jar and quickly retreat into their burrows. The specimens should first be studied alive, if possible, to see the contraction of the dorsal blood vessel and the contractions of the body in locomotion. The setae may be felt by drawing the body gently through the fingers, and they can be examined under a lens. If the worms are to be dissected, or preserved for future use, they should be treated as follows: Place the worms in a shallow dish with wet filter paper torn into shreds. The animals will swallow it and as it passes through the alimentary canal it will carry the dirt from the canal. This part of the process is not necessary unless microscopic sections are to be made. If they are to be kept simply for dissection, they can be preserved at once as follows: — • Place a number of worms in a shallow dish with just water enough to cover them. Add a few drops of alcohol, and, after a few moments, add a little more. Continue adding the alcohol gradually until the animals have become motionless and relaxed. This process should take at least two hours. Then transfer them to a large shallow dish containing 50% alcohol, straightening the animals out, and laying them side by side. After an hour replace the 50% alcohol with 70%; after a few hours change again to a fresh lot of 70% alcohol. Finally the animals are to be placed in 90% alcohol. It is important to keep them straight in this final hardening fluid, and this may be done by laying them out on rather stiff paper, without touching each other, and rolling them, putting about a dozen in each roll. This will hold them in proper shape, and the rolls may be stored in tall jars and will keep indefinitely. Animals so preserved will serve either for microscopic sections or for dissection. Sections should be made by the instructor and, after staining, should be mounted and furnished the student for study. with fine scissors, an incision is made along the dorsal median line, from the head to the posterior end of the body. The body is then opened and the walk pinned out so as to disclose the internal parts. This should all be done under water. If carefully performed the internal parts may be easily worked out, a lens being used to show the smaller parts. To show the nervous system and the nephridia the alimentary canal should be cut through, behind the gizzard, and carefully dissected away in front. There will then be no difficulty in making out all the organs except the ovaries and spermaries. The ovaries may be found by careful study with a lens, but the spermaries cannot be found without special methods. The contents of the seminal vesicles and the ovaries should be examined with a microscope. One of the nephridia should be removed and studied with a low magnifying power. For the study of the histology, sections should be furnished by the instructor. Animals preserved as above described are in good condition for sectioning. They should be embedded in paraffin and stained in picrocarmine. Sections through various parts of the body should be studied, and these should include at least sections through the cerebral ganglia, through the aortic arches, and through the posterior parts of the body showing the typhlosole. The study of these sections with both low and high powers will show the chief features of the microscopic anatomy. More detailed study of the histology is hardly feasible with elementary classes. GENERAL DESCRIPTION THE body of the frog is composed of a head and a trunk, but there is neither neck nor tail. The wide mouth extends far back to the end of the head. On the upper side of the head in front are two nostrils (nares) that open directly through the bones of the skull into the mouth. Farther back on either side of the head are the eyes, provided with two loose folds of skin which serve as eyelids. The upper lid is immovable, but the lower can be brought up over the eye for protection. It is called the nictitating membrane (Lat. nictare = to wink), is semi-transparent, and does not prevent sight wholly when closed. Behind the eyes are two round flat surfaces, which are membranes stretched over a shallow cavity in the skull. They are the tympanic membranes (Lat. tympanum = drum) and serve to collect sound waves and transfer them to the ears which lie within the head. The part of the body behind the anterior appendages or arms is called the abdomen, and the cavity within, which holds the stomach and intestines, is the abdominal cavity. The organs of the abdomen are sometimes called viscera. Of the two pairs of appendages, the fore legs are provided with only four toes, while the hind legs have five toes connected by a web. The hind legs are much longer than the fore legs and are the chief organs used in locomotion. The rest of the body is smooth, gradually tapering behind and ending abruptly just above the attachment of the hind legs. Near the posterior end of the body on the dorsal side is a good-sized opening, the cloacal aperture (Lat. cloaca — sewer), which serves as the common outlet of the intestine, the kidneys, and the reproductive organs. The whole body of the frog is covered with a smooth skin, which is always moist and is abundantly supplied with blood vessels, especially under the arms and on the side of the body. The skin is everywhere loosely attached to the underlying flesh and in certain rather large areas is not attached at all, large spaces being thus left between it and the flesh. These are lymph spaces and are filled with a clear liquid called lymph. When the skin is examined microscopically, it is found to be made of two layers; Fig. 87. The outer layer, the epidermis, ep, is thin, while the inner layer, the dermis, d, is quite thick. The epidermis is made of several layers; the cells of the inner layers are large, rounded, growing cells, while the outer ones are flattened and lifeless. The epidermis increases in thickness from its inner side, and is constantly wearing away on its outer side. The dermis is a mass of connective tissue fibers, among which lie glands, blood vessels, nerves, and the color to the skin. The Skeleton. — The frog has an internal bony skeleton. An internal skeleton is the most distinctive characteristic of the highest animals. Animals with such a skeleton are called vertebrates, a group comprising fishes, amphibians, reptiles, birds, and mammals. No other animals except vertebrates possess true bones. This bony skeleton gives support to the softer parts, gives form to the body, serves to attach the muscles, and enables them to produce the movements of the animal. The skeleton is made of about ninety articulated bones, i. e.t united together at the joints. Some of these form mov- THE FROG 177 able joints, in which a movement of the bones produces a movement of the body. In other joints the bones are firmly grown together forming the immovable joints. The bones of the skull, for example, are so firmly fused that they appear as a single bone; and the bone of the forearm (Fig. 88 r-u) is really made of two bones fused together. Two distinct parts of the skeleton may clearly be seen: (I). the axial skeleton, consisting of the skull and spinal column; (2) the appendicular skeleton, which forms the support for the arms and legs. The axial skeleton. — The spinal column is composed of nine separate bones called vertebrae; Fig. 88 B. Each vertebra consists of 9 centrum, c, and a neural arch, na, the arch inclosing the neural foramen (Lat. foramen = opening). From each side of the arch a process of bone extends laterally, called the transverse process (Lat. trans = across -f vertere = to turn) , tr. On the front and back of each vertebra are two smooth surfaces where the successive vertebrae rest upon each other, i. e., articulate (Lat. articulus = joint). They are the articular processes, or zygapophyses. In their natural position the nine vertebrae are joined together by their centra, the posterior surface of one touching the anterior surface of the next; Fig. A. The neural foramina are thus placed opposite each other, and all together form a tube which incloses the spinal cord. The surfaces of the centra fit by a ball-and-socket joint, each of the first seven vertebrae having a ball on the posterior and a socket on the anterior surface, while the eighth is concave on both surfaces, and the ninth is convex on both surfaces. The nine vertebrae are much alike, but can be distinguished from each other. The first has no transverse process, while the centrum of the ninth has two convex posterior surfaces, and very large transverse processes. From the posterior surface of the last vertebra a long slender bone extends backward to the end of the body, the urostyle (Gr. oura — tail + stylos = pillar); Fig. A, ur. The spinal cord extends into it, but soon passes out through two small openings, on either side, o, as two small filaments. This bone represents the tail found in allied animals (salamanders). The frog has no ribs and the transverse processes end abruptly at a short distance from the centrum. The skull. — In front the first vertebra is articulated with the skull, and the neural canal is continued into the skull through a large opening, called the foramen magnum (Lat. foramen = hole), fm. Inside the skull is a large cavity holding the brain, the cranial cavity. The skull itself is composed of thirty-two bones, rigidly fused together to form a solid structure. These bones, which are shown and named in Figure 88 A and C, may be divided into three groups : 1 . The cranial bones, which form the roof, walls, and floor of the cranial cavity. The floor is made of the basioccipital and the parasphenoid, ps; the walls are made of the parietals, p, the otic bones, and the exoccipitals, ex; and the roof is made of the supraoccipitals and the frontals, /. 2. The facial bones, which form the face. These are the nasals, na, the premaxillas, pr, and the maxillas, mx, above, and the vomers, vo, below. 3. The branchial (Lat. branchice = gills) skeleton. This part of the skeleton is made primarily of two V-shaped arches, lying below the cranium with the open part of the V above, next to the skull ; but the original relation of the V-shaped arches has become so modified that it is difficult to recognize. The first of the arches is the lower jaw or mandible; Fig. Z>, m. The closed part of this arch is in front where the two halves come together. At the back the two halves spread apart and pass backward to the point where the jaw articulates with the cranium at q. The lower jaw is from this joint held attached to the cranium by two chains of bones. One of them is made of the quadrate (Fig. D, qu), and the squamosal, sq, these two forming what is sometimes called the suspensorium. The other chain is made of two bones lying below the cranium, the pterygoid (Fig C, pi), and the palatine, pa. These are firmly fixed to the cranium below. The joint is also attached to the maxilla by a little bone called the quadrato-jugal ; Fig. D, q. Although in the adult frog these chains of bones are firmly attached to the cranium, they are at first free from it, and are really the upper parts of the arches below, rather than a part of, the cranium proper. The second arch is very rudimentary, only a small part of it being left in the frog. It is called the hyoid arch. Although in some animals this is also a welldeveloped V-shaped arch, all that is left of it in the frog is a flat plate, made partly of bone and partly of cartilage (Fig. E), which is so loosely attached to the skull that it is usually lost in prepared skulls. In the living frog it lies underneath the larynx, to which it gives support and rigidity. It is attached to the skull only by ligaments, without any bony connection. When the skull begins to form in the young frog the parts are soft, and only, as development proceeds, does true bone form. Part of the skull forms first as cartilage, a material that is harder than membrane but softer than bone. Later within this cartilage the mineral matter is deposited, forming true bone, and the bones thus formed are consequently called cartilage bones. These are the octipitals, palatines, pterygoids, and the mandibles. The other bones are formed first as membranes rather than cartilage. Within the membrane the mineral bony matter is laid down, and bones developing in this manner are known as membrane bones. The membrane bones are ihefrontals, parietals, parasphenoids, squamosals, nasals, vomers, premaxilla, and the maxilla. At its posterior end the skull is articulated with the first vertebra by means of two rounded, smooth surfaces which fit into two corresponding smooth depressions on the upper surface of the first vertebra. The articular projections are called the occipital condyles; Fig. C, con. Appendicular skeleton. — Each appendage consists of a girdle and the appendage proper. The shoulder girdle is a girdle of bones surrounding the body just back of the head, and holding the arm in position. It is shown from below and flattened out in Figure F. Each half consists of a scapula, sc (the dorsal part of which is made of cartilage), a coracoid, co, a precoracoid and a clavicle fused together, pr. At the place where the coracoid and the scapula come together is a smooth cavity into which the end of the arm articulates, called the glenoid cavity, gc. In its natural position the scapula is bent over the back, with the coracoids touching each other in the middle line below on the ventral side of the body. Behind and in front of them are two pieces of bone, the omosternum, ost, and the sternum, st. These two bones are regarded as a part of the axial skeleton. The arm proper consists of the humerus (Fig. A, hu), the radius and ulna fused together, r-u, six wrist or carpal bones, c, and five fingers, of which the first is rudimentary. Each finger is composed of a metacarpal, me, and several phalanges, ph. The posterior appendages have a pelvic girdle, made of three pairs of bones, all united into one in the adult. One of them, the ilium, is long and runs forward to the transverse process of the last vertebra; Fig. A, il. At its posterior end each ilium joins the other two bones, the pubis (Fig. G, pu), and the ischium, is. At the point where the three bones meet there is a rounded cavity for the attachment of the leg, the acetabulum, ac. The pubes and ischia of the two sides of the body are fused together on the middle line, below the urostyle. The leg consists of a femur (Fig. A, fe), and the cms, cr, which is really composed of a tibia and fibula fused together. Following the crus are the bones of the foot, consisting of two slender bones, the astragalus, as, and calcaneum, ca; then come two extremely small tarsal bones, t, and finally a series of metatarsals, mt, and phalanges, ph. Muscular System. — Most of the bones of the skeleton are more or less movable one upon the other at the articulations. The muscles which move them are numerous and complicated. Each muscle is an elongated mass of contractile tissue, which is usually attached at the ends to two separate bones, the term origin being applied to the attachment nearest to the center of the body, and insertion to the attachment the farthest from the center; muscles pull in the direction of their origin. Since these muscles are numerous and attached to the bones at different places, they pull upon the bones in different directions and produce a great variety of movements. Figure 89 shows the chief muscles of the frog. The names given to them are the same as those applied to the corresponding muscles in man. Joints or Articulations. — Where two bones come together they form a joint. In some cases the bones are so rigidly grown together that there is no motion between them, thus forming the fixed joints, like those that are between the bones which form the skull. In other places the bones are freely movable, forming the movable joints. All the movements of the body are produced at the joints. The bones at these joints are so connected that, while they are held firmly together, they are at the same time freely movable. The ends of the bones are generally more or less rounded, the end of one bone fitting into a rounded depression on the other. The ends of the bones are also covered by a layer of cartilage, which is quite smooth so as to prevent friction. This structure makes it possible for one bone to move upon the other without difficulty. All friction is eliminated, and movement of the bones is rendered easier, by a secretion of fluid which is poured into the joint from the synovial glands. This is called the synovial fluid. To prevent the bones from being pulled apart they are held together by bands of white connective tissue called ligaments. These are tough but flexible, and are attached to the two bones that form the joint. They are long enough to make the motions of the bones free, but short enough to hold them in position and prevent their being pulled away from each other by slight strains. The bones are held firmly in position by the muscles. The muscles which move the bones usually have their origin on the bones above the joint, and their insertion on the bone below. The muscles end in bands of connective tissue called tendons that extend down over the joint to the insertion on the lower bone. The muscles are always tightly stretched in the body and always pulling upon the tendons. As a result the tension upon the tendons holds the two bones of the joint in firm contact. Outside of the muscles and tendons is the skin. The joint thus consists of smoothly moving bones, which are moistened by synovial' fluid, held in position by tightly drawn tendons, prevented from being pulled apart by ligaments that protect them against strains, and moved by muscles. The freedom of motion in the different joints varies with the shape of the bones at the joints. In some of the articulations, one bone ends in a ball which fits into a rounded socket of the other bone. In this type, the ball-and-socket joint, the bones are freely moved in any direction. The joint at the hip and that of the shoulder are examples of this type. In other joints the form of the bones is such that motion is possible only backward or forward. These are called hinge joints, and are illustrated by the joints at the elbow, the knee, the wrist, and by the separate joints of the fingers and toes. In some joints one bone moves around the other as on a pivot. No good examples of this are found in the frog, but in the human body the motion of turning the head, or turning over the hand so that the back or the palm is uppermost, are excellent illustrations. It is evident that the movements of the body are dependent upon the free motion of the bones at the joints, and that the growing of the bones together at a joint, anchylosis as it is called, will destroy all power of motion. Alimentary Canal. — The wide mouth (oral opening) leads into a very large cavity, the buccal cavity. There are teeth on the maxilla,. premaxilla, and vomer (Fig. 88 C, D), which are of use for holding, but not for masticating food. On the floor of the mouth is, a large muscular tongue, attached to the base of the mouth in front, and free behind. Owing to this attachment, the back part of the tongue can be thrown out of the mouth for a considerable distance, serving as an important organ for capturing insects. Just back of the tongue on the floor of the mouth is a narrow slit, the glottis, leading into a tube, which passes to the lungs. Behind the glottis is a larger opening leading to the oesophagus, and hance to the stomach. The nostrils open in the mouth through the roof in front (internal nares); and a pair of openings in the back part of the roof leads to the ears, the eustachian openings. If a slit be made through the skin and flesh of the abdomen, passing forward on the ventral middle line through the sternum, and the body opened, most of the internal organs can be seen. The oesophagus passes directly backward about halfway to the end of the body, where it expands into a large chamber, the stomach (Fig. 90 st), which extends obliquely across the body towards the right. The lower part of the l-» d stomach is called the pylorus ; this passes down into a small tube which FIG. 90.— THE ALIMENTARY makeg a u_shaped bend, called the a large but short chamber, the rectum, r, which communicates with the exterior through the cloacal opening. In front of and to the right of the stomach is the large several-lobed liver. This secretes a liquid called bile, which passes by a duct into the gall bladder, gb, where it is stored for a while and from which it later passes through the bile duct into the duodenum, close to the pyloric end of the stomach. In the bend of the U formed by the duodenum and the stomach, is a slender, yellowish body, the pancreas, p, which empties into the duodenum by the pancreatic duct opening close to the bile duct. The lining of the whole alimentary canal is called the mucous membrane. The whole intestine is slung in position by a thin sheet of membrane, which passes around the intestine and then becomes attached to the abdominal wall. This is the mesentery, and is really a fold of a large membrane that completely lines the body cavity, the peritoneum. The relations of the peritoneum, mesentery, and intestine are shown diagrammatically in Figure 91. In the mesentery are many nerves and numerous blood vessels which carry nutrition from the intestine. The mesentery surrounds not only the intestine, but also the liver and the pancreas. In its folds below the stomach is a rounded red body, the spleen; Fig. 90 sp. Circulatory System. — The circulatory system of the frog, like that of the earthworm, consists of blood inclosed in a network of blood vessels; but it is a more definite system and the blood flows in a more regular course. It consists of a true heart, and blood vessels. The heart is situated beneath the shoulder girdle, in front of the liver and is surrounded by a thin sac, the pericardium (Gr. peri = around + cardia = heart). The heart itself is made up of a sac divided into three chambers, the walls of which are masses of muscles. The fibers of these muscles run in every direction, so that when they contract (systole) the heart is diminished in size and the blood that is in the cavities is squeezed out; when they relax (diastole) the heart expands again and the blood flows into it. Figure 92 shows a diagram of the heart structure, cut open so as to show the interior of the cavities. At the anterior end are two cavities, the right and the left auricles, ra and la; the right, which receives blood from the body, being much larger than the left, which receives blood from the lungs. These two chambers are separated by a partition. At the lower side of the auricles each opens into the ventricle, v, the third and largest chamber below. The openings between the auricles and ventricle (shown by the arrows in Fig. 102), are guarded by valves, which are flaps of membrane, so situated that they allow blood to flow readily from the auricle into the ventricle, but close up at once if the blood starts to flow back into the auricle, as it would do when the ventricle contracts, did not these valves block the passage. The ventricle is a large chamber, partly divided by partitions. This extends forward, on the ventral side of the heart, and at the anterior end of the heart it divides into two arteries, one turning to the right and one to the left. The large vessel is called the bulbus arteriosus, ba, and its two branches are the aortae, ad. This bulbus receives the blood which is forced out of the heart when it contracts. Within it, and at the beginning of the aorta?, are valves which control the flow of the blood, as will be described on a later page. On the dorsal side of the heart is a large thin-walled chamber, the venus sinus (Fig. 92 B, vs), into which open the veins that bring the blood back from the body. This sinus opens into the right auricle, which thus receives all the blood which flows back to the heart from all parts of the body, except the lungs. The blood from the lungs empties into the left auricle by two small veins, one from each lung; Fig. 92 pv. The blood vessels ramify all over the body in a very complex system. The arteries, which take blood away from the heart, are thick-walled and elastic; while the veins, which bring it back again, are thin-walled. The distribution of the chief blood vessels is shown in Figure 92. The bulbus arteriosus soon divides into two branches that turn backward and finally unite with each other in the abdomen beneath the stomach. These two branches, the aortae, ao, give off in their course many vessels, the chief of which are the lingual to the tongue, I, the carotid to the head, co, the brachial to the arms, 6, and the coeliac axis to the organs of the abdomen, ca. After dividing many times into smaller and smaller branches, the arteries finally break up into an immense number of minute thin-walled vessels called capillaries (Lat. capillus = hair). These are microscopic, but of great importance, since all of the interchanges between the blood and the tissues of the body take place through them; Fig. 101. The blood, after passing through the capillaries, enters again into a series of vessels of constantly increasing diameter and finds its way back to the heart. These larger returning vessels are veins, and they unite with others, until finally a few large veins are formed which empty into the sinus; Fig. 92 B. The blood vessels thus form a closed system, and the blood that leaves the heart returns without leaving the vessels. The blood that goes to the intestine by the coeliac axis, ca, passes through two series of capillaries before again entering the heart. It first passes into capillaries in the intestine, where it receives nutriment absorbed from the food; then it is collected into a large vein, the portal vein, pv, which enters the liver, and breaks up into another system of capillaries; then, by the way of the hepatic vein (Gr. hepar = liver), hv, it enters into the large posterior vena cava (Figs. A and B, ptc), which leads to the venus sinus. This system of veins and capillaries in the liver is called the portal system. Part of the blood that goes to the legs also has a double system. It first enters the capillaries in the muscles of the legs, and on its way back a part of it passes through the kidneys, where it is again broken up into capillaries. This is the course of the blood which returns from the leg through the renal-portal vein (Fig. 92 rp), but the rest of the blood from the legs is diverted to an abdominal vein, a, which enters the heart without passing through the liver. Both the liver and the kidneys have their own supply of blood from the aorta, as well as that received from the veins. The vessels thus far described are called the systemic circulation, in distinction from the pulmonary circulation, which is the circulation in the lungs. The lungs are elastic bags (Fig. 92), capable of much expansion when inflated with air, but collapsing if the air is removed. They are connected with the mouth by the larynx, which opens at the base of the tongue through the glottis. Through the glottis and the larynx air is taken into the lungs to purify the blood. The arteries which supply the lungs, the pulmonary arteries, pu, arise from the main arteries near the heart. From each of these an artery is given off to the skin under the arm, the cutaneous, cu. Since in the lungs the blood is purified by the oxygen of the air, and through the skin it is purified by the oxygen in the water, the frog can live either in the water or in the air, i. e., it is amphibious. The blood that is purified in the lungs enters the heart again by a pulmonary vein, puv, which flows into the left auricle. The pure blood in the left auricle is thus kept separate from the impure blood in the right auricle, but as soon as the auricles contract the blood of both auricles is forced into the single ventricle, and intermingles. Although the blood in the ventricle is really mixed, still the blood upon the right side of it, since it received blood directly from the right auricle, will contain more impure blood than that on the left side, which is connected directly with the left auricle. The pure and impure blood are kept partly separate by muscular partitions extending irregularly through the ventricle. plasma, called platelets, of which little is known. Lymph System. — Besides the blood vessels, the frog has a system of much smaller lymph vessels in the skin, the intestine, and other parts of the body. These are thin walled and filled with a colorless liquid, the lymph, and are so delicate the,t they can be seen only in specially prepared specimens. In places these vessels are connected with spaces between the tissues, lacunae, and with the large cavities of the body. In the intestine the lymph vessels receive a special name, the lacteals. Lymphatic glands are found in connection with the lymph vessels, and in the frog there are also two pairs of lymph hearts, whose contraction propels the lymph in its circulation. The Nervous System. — The nervous system consists of: (1) The cerebrospinal axis, (2) The cranial nerves, (3) The sympathetic system. Cerebrospinal Axis. — The brain and spinal cord are on the dorsal side of the animal, within the neural canal and the cavity of the skull; Fig. 94. The brain consists of several distinct parts. Beginning in front they are as follows: The olfactory lobes, ol, the cerebral hemispheres, ce, the thalamencephalon, th, the optic lobes, op, the cerebellum, cb, and the medulla oblongata, m. The cerebellum is very small, and the medulla appears to be only an enlarged continuation of the spinal cord. In the latter there is a plexus) . The cavity is called the fourth ventricle, and it communicates with other cavities in the brain. On top of the thalamen- cephalon together constitute the forebrain, the optic lobes form the mid-brain, and the cerebellum and medulla form the hind-brain. The relative development of these different parts varies widely in different animals, and in the higher vertebrates the cerebrum becomes much the largest part of the brain, this development reaching its maximum in the human species. From the posterior part of the medulla the spinal cord, sp, extends through the spinal column, tapering to a minute filament, which extends a short distance into the urostyle. The brain and spinal cord are covered by two membranes, an outer membrane, the pia mater. The Craniospinal Nerves. — Twenty pairs of nerves arise from the brain and cord, — ten from the brain, and an equal number from the cord. Those from the brain, the cranial nerves, supply the organs of special sense and the muscles and other organs of the head, the heart, lungs, and stomach. They are as follows: — the nasal cavities. 2. The optic nerves. These two nerves arise from the optic lobes, cross each other to form the optic chiasm, and then each passes to the eye on the opposite side of the head. stomach. From the spinal cord arise ten pairs of spinal nerves, one between the skull and the first vertebra, and one between each vertebra and the next; Fig. 95. The first supplies the tongue (motor); the second and third unite to form the nerve going to the arm, the brachial nerve (Lat. brachium = arm); the fourth, fifth, and sixth supply the middle region of the body; and the seventh, eighth, and ninth unite by cross branches to form the sciatic plexus (Lat. plectare = to braid), from which arise the nerves that supply the leg, the sciatic nerve, which is the largest in the body; the tenth nerve supplies the region of the urostyle. Each nerve arises from the cord by two roots, of which the anterior root carries impulses away The Sympathetic System. — In the abdominal cavity, lying on each side of the spinal column, is a chain of minute nerve ganglia, ten in number, which are also connected with the spinal nerves; Fig. 95 sy. These constitute the sympathetic system. From these two chains of ganglia minute nerves are given off, chiefly to supply the intestine, the kidney, and the other organs of the abdomen. Although connected with the spinal nerve, the sympathetic system is quite distinct and has special functions. The microscope shows that the nervous system, like that of the earthworm, is composed of an enormous number of neurons, each with its cell body, dendrites, and axon. These are massed in the brain and cord, and there are many also in the ganglia outside of the cord. They are so situated that part of them carry impulses to the center, and part of them carry them in the reverse direction. Their numbers are greater and their relations more complex than those of the earthworm. The Sense Organs. — At the peripheral end of all of the sensory nerves are found very complicated organs, constructed so as to be affected by certain external stimuli. When they are stimulated impulses start from them and pass Olfactory organs. — Just within the nostrils are two little cavities occupied by the olfactory sacs. In these sacs the olfactory nerves are distributed, ending in delicate nerve cells, which are sensitive to odors; Fig. 96 A. SENSORY NERVE CELLS A, Olfactory cells; B, cells in the retina, sensitive to the light, showing the rods on the left and cones on the right. :, sclerotic coat. The eyes. — The eyes are large, spherical organs, planned after the structure of the vertebrate eyes in general. Figure 97 is a cross section of an eye showing the important parts. It is a spherical chamber, the walls of which are opaque, except in front, where they are transparent, and act like the dark chamber of a camera. The walls of the chamber are made of several layers. In the very front is the cornea, presenting a transparent curved surface. The back part, comprising about two-thirds of the chamber wall, is made of three layers. On the outside is a sclerotic coat, sc, composed of fibrous tissue and cartilage; next to this a thin coat containing pigment, the choroid, ch, and inside of this a still thinner retina, r, which is the sensitive part of the eye. At the back of the chamber is an opening through which the optic nerve enters, on. After entering the eye the nerve spreads out on the retina, where it is affected by the light entering the eye. The chamber of the eye is divided into two parts by a large spherical, transparent, crystalline lens, held in position by several bands of fibers, shown at I. Anteriorly the lens is partly covered by an opaque membrane, really a continuation of the choroid, which grows out from the wall of the chamber on all sides. This is the iris, and it covers the outer part of the lens, except in the middle, where the lens is not covered. This opening is the pupil, and serves to allow light to enter. The iris contains pigment cells, which give the eye its color. Each of the two chambers of the eye is filled with a transparent fluid. That lying between the cornea and the lens is the aqueous humor, and that back of the lens, which is rather more solid, is the vitreous humor. The retina, which lines the eye chamber, is an extremely complicated organ, made of hundreds of thousands of end organs of sensitive nerves. It is a complex of neuron bodies, dendrites, and axons (Fig. 96 B)t and is highly sensitive to the light, which is focused upon it by the lens. Attached to the ball of the eye are six muscles, by means of which it can be rotated in any direction: The ears. — The frog has no external ears. Just back of the eyes are two rounded, flat depressions, each formed by a membrane which covers the real ear. If the thin skin which covers this area be removed, a rather tough, flat membrane will be found beneath, which is the tympanic membrane proper. This membrane extends over a shallow conical cavity, called the tympanum or ear-drum. This cavity connects below with the mouth through the eustachian tube. Extending across this is a slender bar of bone and cartilage, called the columella. This is attached to the membrane at one end and connected with the inner ear at the other, and transmits vibrations of the membrane to the inner ear, the real organ of hearing. u, utricle. The inner ear, which is :he true sensory end organ of the auditory nerve, lies embedded in the bones of the skull. Its general appearance may be seen from Figure 98. It is quite a complicated organ, and the auditory nerve enters in and finally terminates in delicate endings, which are readily stimulated by the vibrations brought from the exterior through the membrane equilibrium. Other senses. — The sense of smell is located in the nostrils. These openings lead into little olfactory form the termination of the sensory nerves. They are of different kinds, and doubtless have different functions, but all are associated with what is in general called the sense of feeling or touch. The Excretory Organs. — Lying in the back part of the abdomen near the legs are two flat, rather oval bodies, one on either side of the middle line, the kidneys; Fig. 92. Each is abundantly supplied with blood vessels, a fact which indicates important functions. Microscopic study shows them to be made of many coiled tubes, similar to the nephridia of the earthworm. These tubes remove excreted products from the blood which passes through them. From the outer side of each a small duct, the ureter, passes backward toward the cloaca, where it empties into the bladder (Fig. 90 bl) , a rather large twolobed sac, which may be filled with the urine secreted by the kidney, or may collapse when empty. It opens into the cloacal chamber, and its contents are discharged through the common cloacal opening. (In man a special duct, the urethra, leads from the bladder to the exterior.) Reproductive Organs. — The two sexes in the frog are in separate individuals, thus differing from the condition found in the earthworm. The male may be distinguished externally by a thick pad on the under side of its thumb, which is rather large in the spring, but small at other seasons of the year. The spermaries are found in the male at the upper end of the kidneys; Fig. 92 sp. They are two in number, rounded or oval in shape, and of a light yellowish color. Attached to them are usually several branching masses of yellow fat. The sperm produced in the spermaries are carried through some delicate ducts into the kidney. These ducts, the vasa efferentia, pass through the kidneys and empty into the ureters, which lie on their outer edge. The ureters in the frog thus serve for the exit of both the kidney secretion and the secretions from the spermaries. These ureters are, in some species of frogs, enlarged into a small sac just at the point where they enter the cloacal chamber, and in these sacs the sperms are stored until making many coils, finally opens into the cloacal chamber at the back. Just before its termination it is swollen into a rather large, thin-walled chamber, the uterus, ut, in which the eggs may be stored for a time after passing through the oviducts before the final egg laying. These long ducts vary greatly in size at different seasons, being small in the summer, but enlarging with the enlargement of the ovaries, and swelling greatly in the early spring preparatory to egg laying. In the walls of the oviducts are numerous little glands, whose function is to secrete material around the egg to form the shell or other protective covering. They are nidamental glands (Lat. nidus = a nest). It will be seen that the sexual organs and the kidneys are very closely connected. They lie close together, have a common opening, and in the male the same duct, the ureter, serves for the exit of the sperms and the urine. A similar close relation is found in other vertebrates, and a study of the development of the animals shows that their ducts are originally derived from the same organ in the embryo. The two systems together are known as the urogenital system. In the frog this system opens to the exterior with the intestine by the single common cloacal opening. In higher animals they may have separate openings. For a detailed dissection of the frog, reference must be made to some of the numerous laboratory manuals. The brief general directions given below will be sufficient to illustrate the topics discussed in the text, and at least this amount of laboratory work is necessary to make the text properly intelligible. If the specimens are obtained alive they should first be killed with chloroform, and, while still fresh, all of the points in the external anatomy should be made out. Note should be made of the following: head; body; .absence of tail; the loose skin, attached, however, at certain points; arms; numbers of fingers; legs; number of toes; web between the toes; mouth; nostrils; eyes with eyelids; ears; cloacal opening. Open the mouth and note tongue; glottis; gullet. The dissection of the organs of the abdomen can best be made with a freshly killed specimen, but it may be done satisfactorily with animals preserved in alcohol or formalin. The dissection of the brain and spinal cord should always be made upon animals preserved in alcohol, since these organs are too soft to handle in fresh specimens. A mounted skeleton of the animal should be at hand for study and comparison with the animal under dissection. The order of dissection given below is so planned as to make it possible to do practically all of tlie dissection upon a single specimen. The specimen may be preserved in formalin and the work carried out at leisure. If the order given is followed, it is possible to have a large class working at the same time, and, when the work is finished, all of the important parts in the anatomy will have been made out, except the skull and the shoulder girdle, these having of necessity been destroyed in opening the body and in exposing the brain. If frequent references are made to the description of the frog given in the text, the brief description here given will be sufficient to make a satisfactory dissection. Open the frog by a median ventral incision, made with scissors, extending from the legs forward to the sternum, cutting through both skin and flesh. The blunt end of the scissors is then to be thrust under the sternum, and this girdle of bones is to be cut through. This will make it possible to open the abdomen, pinning out the flaps of the abdominal walls and the arms so as to expose the organs of the abdomen. If the frog is a freshly killed specimen, all of the subsequent study of the viscera should be made with the animal immersed in water. If the frog is a preserved specimen, this is not so necessary. The organs of the abdomen may now be studied. The following parts should be made out without any further dissection, being disclosed simply by pushing the organs one after the other to one side, and they may bo examined conveniently in the following order: liver; heart; large arteries around the heart; veins entering the heart; stomach; intestine; gall bladder; rectum; mesentery, which contains blood vessels that may be traced to the liver. In opening the body, if the specimen is a fresh one, there is danger that some of the blood vessels may be cut, making it difficult or impossible to follow the blood vessels. In order to work out the blood vessels satisfactorily, it is necessary to have an injected specimen. These may be bought of dealers in natural history supplies, or the injection may be done by the instructor. If the specimen is a female, the body cavity will, at certain seasons of the year, be filled with an enormously expanded ovary, filled with eggs. In order to make out the other abdominal organs, these must be removed carefully, so as not to injure the other parts. After they have been removed there will appear lying on either side of the back part of the abdomen the very much enlarged oviduct, showing as a much coiled tube. This should also be removed, note .being made of its connection with the cloacal chamber behind. If the ovary is not thus enlarged, or if the specimen is a male, it is not necessary to remove the reproductive organs to show the other features. With the organs all in position, now make out the rectum; the bladder; the spleen; the cloacal chamber; the kidneys; the spermaries; the ovaries and oviduct in the female, and the spermaries and vas deferens in the male. Remove the heart, liver, stomach, and intestines. This will disclose the lungs; the two systemic arteries uniting to form the dorsal aorta, which should be traced to where it divides to supply the legs; the nerves to the arms; nerves to the back; three large nerves arising from the backbone and extending toward the legs, and finally uniting to form the sciatic plexus, from which arise the large nerves entering the leg. By lifting up the aorta gently, delicate branches of the sympathetic system may be seen and traced to their ganglia. One leg of the animal should be dissected to make out the muscles, nerves, bones, and joints. The muscles should be separated from each other and traced to their origin and insertion, special notice being taken of the long tendons extending from the lower muscles down to the toes. In the joints, note the freedom of motion of the bones; the tendons, which extend over them; the rather loose ligaments that unite the bones; the readiness with which the bones come apart when the ligaments are cut; the smooth surfaces of the ends of the bones; and the cartilage that covers their ends. (If there is time for more careful dissection, reference must be made to laboratory guides on the dissection of the frog.) Clean all of the soft parts from the bones of the leg, separating and identifying each bone. Examine the eyelids; the iris; the pupil. Make an incision through the iris and remove the lens; note the cavity of the eye behind the lens. Cut an incision through the tympanic membrane, noting the shallow cavity beneath it, the tympanic cavity, the bony columella extending across it to the skull. A bristle thrust into the bottom of this cavity will enter the mouth through the eustachian tube. Remove with a knife a bit of the -flat bone on top of the skull, exposing the brain; and then, with forceps and scissors, break away the bone so as to expose completely the brain and spinal cord down the back to the urostyle, taking care not to injure the soft parts. Identify all parts of the brain as described on page 193. The skeleton should be studied from another specimen. Remove all the soft parts from the skeleton, separating all the bones. Clean and identify each (Fig. 88), and compare with the mounted skeleton. BOOKS FOR REFERENCE ECKER, The Anatomy of the Frog, The Macmillan Co., New York. HOLMES, Biology of the Frog, The Macmillan Co., New York. MARSHALL, The Frog, The Macmillan Co., New York. MORGAN, Development of Frogs' Eggs, The Macmillan Co., New York. GUYER, Animal Micrology, University of Chicago Press, Chicago. special reference to the frog. Alimentary System. — The primary purpose of the alimentary canal is the digestion and absorption of food. The food of animals is always organic, since animals are unable to utilize mineral substances upon which plants subsist. Animals feed upon the substances manufactured by plants: starch, the first product of photosynthesis, may serve animals for food, and the same is true of sugar, fats, and proteids. These foods are usually in a solid form when taken into the animal's mouth, and in order to be of any use they must pass from the alimentary canal into the blood vessels. Solid food is incapable of passing through the intestinal walls, and must be changed so that it can be dissolved in the liquids of the alimentary canal, a process called digestion. Digestion is brought about by digestive fluids which are secreted by digestive glands within the alimentary tract. The frog has no salivary glands such as man possesses, and the first digestive glands are in the walls of the stomach. These are microscopic in size and are called gastric glands. They are present in large numbers and secrete the gastric juice, which is poured directly upon the food after it reaches the stomach. A second digestive gland is the pancreas, lying just below the stomach and pouring its secretion, the pancreatic juice, by a special duct into the intestine, close to the stomach. This is mixed with the food just as it leaves the stomach and after it has been acted upon by the gastric juice. By the action of these two digestive fluids the solid foods are changed in their nature and rendered partly soluble. They are then dissolved in the intestinal liquids, becoming a thick, rather slimy mass of dissolved material. The different foods eaten by the animal are subject to different changes under the influence of the separate digestive fluids, those secreted by the stomach producing a different kind of digestion from those of the pancreas; but all aid in rendering the food soluble. Absorption. — The food is driven through the alimentary canal by the muscular contractions of its walls. These muscles are in two sets, one extending lengthwise and the other running around the intestine in a circular direction. By their contraction waves of constriction pass along the intestine, forcing the food slowly along. This peculiar writhing motion of the intestine is spoken of as peristalsis (Gr. peri = around + stalsis = a compression). As the food is pushed through the intestine its digestion and solution is completed and it begins to pass through the walls of the intestine into the surrounding blood vessels. As the intestinal contents pass onward more and more of the nutriment contained in the food is absorbed from it and enters the blood. The undigested and useless portions of the food pass on and eventually, in the form of faeces, are voided through the cloacal opening. Circulation. — The food absorbed into the blood is now carried over the body in the blood. The liquid part of the blood, the plasma, is the circulating medium, the red and white corpuscles having special functions. The red corpuscles (erythrocytes) , which are by far the most numerous, give the blood its red color and are associated with respiration. The white corpuscles (leucocytes) , of which there are several kinds, have various functions, one of which is the removing of foreign bodies from the body and protecting it from the attacks of microscopic germs, or other irritating substances that may enter the tissues. The white corpuscles with this power are called phagocytes (Gr. phagein = to eat + cytos) ; they are able to leave the blood vessels, by forcing their way through the walls of the capillaries; Fig. 101 leu. They then migrate among the tissues and collect at any part of the body to guard it from an attack. walls of the capillary into the surrounding tissues. the heart, which acts as a pump. In the frog's heart there are three chambers and the circulation is as follows: The blood which enters the heart from the body, which is impure blood, the arrows in Figure 102. The ventricle thus receives both pure and impure blood, the pure blood being poured into its left side and the impure blood into its right side. These two kinds of blood are partly mixed, excepft for a fraction of a second, when they are separate from each other. They are kept from mixing too quickly by several muscular bands stretching from the walls of the heart. But almost at the same instant that the ventricle is filled it contracts, and its contained blood is forced into the large artery, the bulbus arteriosus. This artery, as will be seen from Figure 102 ba, opens on the right side of the ventricle and consequently will receive first the blood which entered the ventricle from the right auricle, which is impure blood. Thus impure blood passes first into the arteries, to be followed by mixed blood and finally by the purer blood that comes from the. left side of the ventricle, and hence from the left auricle. With each contraction of the heart there enters the arteries first a little impure blood, then a little mixed blood, and finally a little pure blood. From Figure 102 pu, it will be seen that the first branch of the artery passes to the lungs. In the bulbus arteriosus are valves so arranged that the first blood passing from the heart with each beat goes to the lungs; after these are partly filled the next blood passes through the blood vessels shown at ao, down to the arms and to the lower parts of the body; and finally the last of the blood that comes out with each beat of the heart passes up into the purest blood is needed. The two auricles are separated from the ventricle by valves, va, opening mechanically in one direction, in such a way that when the heart beats the blood is forced onward and never backward. The blood passes out through the arteries and is carried by the numerous branches into the various parts of the body, the small branches breaking up finally into minute twigs called capillaries, that are distributed in great abundance in every active organ. While passing through these capillaries, the food materials, absorbed by the blood from the alimentary canal, and the gas absorbed from the lungs, pass from the blood into the tissues where they are needed. In this way the food and oxygen are supplied to the active tissues of the body. At the same time waste products, which have been produced in the active tissues, are returned to the blood, so that the blood, after passing through the capillaries, goes back to the heart as impure blood. After reaching the heart the impure blood goes to the lungs, where part of its impurities are passed off into the air. Lymph System. — A part of the circulatory system is called the lymph system. As the blood is flowing in the capillaries some of the liquid plasma soaks through the walls of the capillaries out into the tissues. When it reaches the tissues it is no longer called blood but lymph, and is a colorless clear liquid which bathes every living cell. This lymph contains, dissolved in it, the nutriment absorbed from the intestine; and, since it now actually bathes the living cells, these can take from it directly the nourishment they need for their activities. Into this lymph the living cells also excrete all the waste products that have resulted from their life processes, the lymph receiving all the wastes of the body. The gases, which comprise part of this waste, pass at once into the blood by diffusion; but the other materials remain dissolved in the lymph and finally reach the blood by the following course: The lymph gradually collects in tiny spaces, lacunae, scattered over the body, and from these flows into little vessels connecting with each other, called lymph vessels. These small vessels unite together to form larger ones and the larger vessels finally empty into the veins. The vessels around the front end of the body converge to two minute sacs lying deeply imbedded near the third vertebra; and the vessels in the hind part of the body converge into similar sacs situated over the hips, near the lower end of the urostyle. These four sacs have muscular walls and pulsate, and are called lymph hearts. When they beat they force the lymph into the veins which lie near them and with which they are connected. In this way the lymph, which originally came from the blood plasma by dialyzing through the walls of the capillaries, returns into the blood; thus all the secreted products from the living cells pass into the blood, either directly as in the case of gases, or indirectly by passing first into the lymph and then emptying with the lymph into the blood vessels. NOTE. — A similar lymphatic system is found in all higher animals, but its course is different from that in the frog. In man, for example, the lymph rises by diffusion through the capillaries, and collects in lacunae and lymph vessels in a similar manner. But there are no lymph hearts. The lymph vessels unite to form quite large vessels, and all eventually empty into the large veins in the neck. There are two chief trunks of these vessels, one bringing the lymph from the upper parts of the body and emptying into the right jugular vein, and the other, a much larger one, bringing the lymph from the lower parts of the body and from the alimentary canal and flowing up through the thorax, to empty finally in the left jugular vein. This latter lymph vessel is called the thoracic duct. Respiration. — The impure blood from the heart passes through the pulmonary artery to the lungs (Fig. 92), a part of it going into a small branch, the cutaneous, cu, which carries it to the skin. The lungs are air sacs connected with the mouth. Just back of the tongue we have already noticed the glottis, which is a slit leading into a small cavity holding the vocal cords, whose vibrations cause the various sounds produced by the animal. This cavity is the larynx and it lies just under the throat. At its inner end it opens at once into the lungs, since the frog has no windpipe (trachea) such as is found in animals with long necks, like man. The air enters the lungs through the larynx and, filling them, comes in close contact with the blood, which is distributed in finely divided capillaries in their walls. The blood that goes to the skin through the cutaneous artery is distributed in fine capillaries and brought into close contact with the oxygen which is dissolved in the water in which the animal lives. puscles, absorbs large quantities of oxygen as the blood is flowing through the lungs and skin. The oxygenated blood then passes from the lungs back to the heart and is pumped out through arteries to the tissues. Here the red blood corpuscles give up their oxygen, and at the same time the blood absorbs carbon dioxid (CO2) from the tissues. When the blood, therefore, leaves the capillaries on its journey back to the heart, it has left behind its oxygen and taken in its place carbon dioxid, which it gives up when it next reaches the lungs or the skin, at the same time taking up oxygen. The process of respiration is therefore a system of gas exchange. Metabolism. — In the living tissues the food and oxygen are chemically combined, an oxidation of the food taking place. The chemical changes that occur are numerous and result in the formation of new materials for the body, producing growth , development of muscular activity, and all of the other phenomena of life, and finally resulting in the appearance of waste products. The waste products are chiefly three : (1) a gas, carbon dioxid (CO2) ; (2) a liquid, water (H20) ; (3) a solid, called urea (CON2H4), which contains the nitrogen. Although the urea is solid under all ordinary conditions, it is dissolved in the liquids of the body, since it is soluble in water, and is therefore in a state of solution while in the body. These three waste products are not only valueless but distinctly harmful, and it is necessary for the body to get rid of them. The series of chemical changes which finally results in waste products is called metabolism. Excretions. — The elimination of the waste products of metabolism is known as excretion. The carbon dioxid gas passes into the blood, and when the blood reaches the lungs the gas diffuses from the blood into the air. The waste water also passes into the blood and is passed off from the body through the kidneys, the lungs, and the skin. The urea finds its way into the blood, and as the blood flows through the kidneys (Fig. 92), they take the urea from it. They then pass it through their ducts dissolved in the urine, and it goes to the bladder and the body. Motion. — The motion of the frog is accomplished by the muscles. The muscles are numerous, and each has its own special attachment to the bones; Fig. 89. Every muscle possesses the power of shortening, but has no other function; and the ordinary muscles are attached to two bones in such a way that when the muscle shortens one bone is moved upon another. All the motions of the body are produced by the shortening of the different muscles. Many of the muscles are in pairs, one of each pair serving to bend a joint, the flexor, and the other straightening it, the extensor. The details of their actions we cannot consider here, but it will readily be seen that with the many muscles present in the frog's body a great variety of motions can be produced. The selection of the proper muscles to produce any desired motion is a complicated process, some motions indeed requiring the orderly selection of a large number of muscles, which must act together in perfect harmony. This power of selecting the muscles and causing them to act in unison and in harmony with each other is called coordination. The Coordinating System. — The nervous system of the frog controls all other functions. As already seen, it consists of (1) a central system, the brain and spinal cord; (2) the peripheral system, the latter composed of the nerves distributed over the body, and the various end organs of the nerves. The central system is really the center of activity, and the nerve fibers are merely paths for conducting impulses from one part of the body to another. Some of the end organs at the outer ends of the nerves receive impulses from the brain; others receive them from the exterior and transmit them to the nerves to be carried to the brain. The brain corresponds to the central station of a telephone system, which is connected with all parts of the city by wires hav- ing at their ends the individual telephones which may receive communications from the central system or send messages to it. So the central nervous system contains the intelligent, originating force, and being in communication with every part of the body, controls all of the functions in such a way that they act in harmony. This central system has a series of efferent nerves, by which it sends messages outward, and a series of afferent nerves, by which messages are brought inward to the brain. The most important of the latter are the sensory nerves. Sense organs. — Each sensory nerve ends in a sense organ, so formed that it is excited by definite external stimuli. One of them, the ear, is stimulated by vibrations of the air; another, the eye, by vibrations of ether; others by a slight pressure or touch; others by heat; others again, by chemical substances, producing taste; and others by vapors in the form of gases, causing the sense of smell. Figure 96 shows the microscopic structure of some of these sensory end organs. In each case the end organ is started into activity by an external stimulus, and when thus excited an impulse starts from it over the nerve fiber and passes to the central part of the nervous system. In the central system, the stimulus produces what we call a sensation, and this gives the brain a knowledge of what is going on at the outer end of the nerve. Sensation never occurs until the impulse reaches the brain. From these sensations the brain obtains information as to what is going on in different parts of the body, and upon this information, bases its knowledge and regulates the activities of the body. Reflexes. — The nervous system is made up of a mass of neurons whose connections with each other are inconceivably complex. These neurons, with their long axons, unite in harmonious activity the different organs of the body, and they do this by virtue of the fact that their axons, though distributed all over the body, all converge in the central system, where they can be associated together by the numerous neuron bodies that compose these central ganglia; Fig. 85. The courses taken by these impulses after reaching the centers are complex in the extreme, and quite beyond our power to follow. They are accompanied by sensations and by whatever of consciousness the animal possesses, and they * might move if touched by an irritating object, without any An impulse that starts from the sense organs in the skin, s, passes to the spinal cord through the afferent nerve, a. Upon reaching the center, at c, the impulse may pass over to the motor cell, TO, from whence it passes downward through the efferent nerve, e, to the muscle fibers, mu. Part of the impulse from the c may pass up through the fiber, a, to the brain and produce sensation. necessary consciousness on its part, as actually happens in sleep, for example. Such an action is called a reflex act, a name derived from the idea formerly held that the impulse starting from the sense organ was simply reflected back after reaching the cord. Although we know to-day that the impulse is not simply reflected back, but is profoundly modified in the cord, the name reflex is still retained for this type of reaction. Although a reflex act is not necessarily accompanied by consciousness or sensation, this is not always the case. From the diagram (Fig. 103), it is evident that the impulse, on its arrival in the cord, may not all pass into the motor nerve cell, but some of it may pass up through the fiber, a, toward the brain, and this part of the impulse, when it reaches the brain, will give rise to a sensation. The action that follows might still be the reflex, or it might be a truly voluntary one, started by the brain as the result of the sensation. Reflexes play a very large part in the life of all animals. Even in our own life many of our actions are thus reflexly performed without any special volition. Reproduction. — The eggs of the frog are only developed at certain seasons of the year. Late in the spring and early in the summer the ovaries are small, but toward the end of summer and in the fall the eggs begin to develop and cause the ovaries to expand until they almost fill the body cavity. When the frog goes into the dormant condition of hibernation (Lat. hibernare = to pass the winter), the female is usually greatly distended with the swollen ovary, and in this condition the winter period is passed. The oviducts have also enlarged and elongated, and remain so during the winter, while the animal is buried under ground. With the opening of the spring the frog emerges and resumes its active life, and in a few weeks reaches what is called the breeding season, which means the season for the discharge of the sexual products. As this season approaches the eggs break out of the ovary and fall into the abdominal cavity. The funnel-shaped opening of each oviduct is provided with vibratile cilia (Fig. 100), and, probably by their action, the eggs are swept into the opening, and then slowly pass down through the coils of the oviduct toward the uterus. As they pass along they are covered with a gelatinous substance, which is secreted from the glands in the walls of the ducts and forms a layer around the eggs. When the eggs reach the uterus they are stored there for a time until the animal is ready to lay her eggs. With the approach of the breeding season the spermaries of the male also become very active and secrete sperm fluid. This passes down the ducts to be stored in the seminal vesicles, where it remains until the period of copulation. At the breeding season the male frog fastens himself to the female, who is about to lay her eggs, and remains firmly attached to her until she lays them, remaining thus attached for days or even for weeks in some cases (copulation). After the eggs are laid the male leaves the female and pays no further attention to her. When the eggs are laid they are rather slowly passed from the body by the cloacal opening, and at the same time the male ejects the sperm fluid from his body over them. The sperms themselves penetrate the jelly and eventually enter the eggs, producing fertilization. After the eggs are thus laid the ovaries and the oviducts contract and in a short time shrivel to a size much smaller than that which they had at the 'breeding season. This diminished size continues until late in the summer, when the ovaries begin to increase in size again with the growth of the ova, in preparation for the next breeding season. The eggs of the common frog are always laid in water and at first form a rather small mass of eggs with their surrounding j elly . But the j elly quickly absorbs the water and swells to many times its original size, inclosing each egg in a thick layer. This jelly appears to have two purposes. It is a protection to the eggs from the attack of birds and perhaps other enemies. It seems also to have the power of absorbing the sun's rays and holding them back from too great radiation, the result being that the egg is kept warmer than it would be without the jelly. This hastens the development, since its rate is dependent on temperature. Our common frog lays its eggs in irregular masses, which may be found in abundance in the spring months around pools of fresh water. The toad has somewhat similar breeding habits, but lays its eggs in long strings. Inside the jelly the fertilization of the eggs is completed and the development begins, and here the young remain until they are ready to hatch as young larvae. PHYSIOLOGY OF THE EARTHWORM The organs of the earthworm are much simpler than those of the frog. Some of the systems of organs found in the frog are apparently absent in the earthworm. There are, for example, no lungs nor other special organs devoted to respiration; there is neither heart nor system of bones for support. But although some of these systems of organs appear to be absent, their functions are not lacking. In other words, the earthworm has exactly the same functions of life as the frog, but carries them out in a simpler way. Respiration is carried on through the skin; the motions of the animals are confined to a writhing motion made by the muscles of the body wall ; the circulation of the blood is produced by the contraction of the blood vessels instead of by a heart; excretions are carried on through the skin and also by the nephridia. In short, the earthworm has the same general functions as the frog, only they are carried out on a simpler scale and by a simpler series of organs. Since its organs are simpler, we speak of the earthworm as having a lower organization than the frog. THE DIFFERENCES BETWEEN ANIMALS AND PLANTS IF we confine our attention to the larger organisms, the differences between plants and animals are very evident; but when we turn our attention to some of the lower members of each group, the differences are less evident and most of them disappear. A castor bean and a frog are very unlike, but Peranema and Euglena (Fig. 29) are so similar that it is hardly possible to say whether either of them is an animal or a plant. In their life functions, too, the higher plants and animals differ widely. Most of the general functions of animal life are possessed in a modified form by plants also; but since some functions are possessed by animals alone, a division of functions into two categories is frequently adopted. Vegetative functions are those possessed by both animals and plants. They are chiefly associated with food and growth, and are: alimentation, circulation, respiration, excretion, and reproduction. by plants. They are motion and coordination. Both animals and plants have vegetative functions, but they are carried on quite differently in the two groups, resulting in a radically different type of life in animals and plants. The study already made of the biology of organisms enables us now to ask intelligently, What is the difference between animals and plants? Although it is fairly easy to see the difference between a tree and a dog, when we come to extend the comparison to smaller and lower organisms it becomes more and more difficult to determine any distinc- tions between the two kingdoms. Indeed, when we analyze the subject to its limit, we find it impossible to draw any sharp line separating animals and plants, for there are some living things which show so few characteristics of either kingdom that we cannot determine with accuracy whether they belong to one group or the other. It is possible, however, to draw a general distinction between the two, and from this general distinction we can derive certain other secondary differences, which are more evident. The Fundamental Distinction. — The primary distinction between animals and plants is in the process of photosynthesis. The plant kingdom alone has the power of utilizing the rays of the sun and manufacturing starch out of carbon dioxid and water: animals never have this power. From this primary distinction arise several other minor points of difference, more or less sharply separating these two groups. Secondary Differences. — A . Color. — Plants which have the power of photosynthesis are provided with the green coloring matter, chlorophyll. Animals, on the other hand, are not provided with this coloring matter. B. Motion. — Since animals live upon solid foods, they have to search for it, and they are, as a rule, provided with motion. Plants, on the other hand, having no need to search for their food, since they find it in the atmosphere and soil, have not, as a rule, developed the power of motion. The various methods of motion developed by animals may be summarized as follows: (1) Amoeboid movement, as found in Amoeba, by means of lobes of the living protoplasm. It is confined to unicellular organisms. (2) Ciliated and flagellated motion, produced by vibratile, hairlike processes of the protoplasm. Cilia are moderately short processes, and where found are usually present in large numbers. They are found in many unicellular animals and also in multicellular forms. Even the highest animals have cilia on the cells lining the air passages and various other ducts. Flagella are longer than cilia, and occur only in small numbers on any cell, one or two being the usual number. Higher animals do not have true flagella, except in their sperms; see page 250. (3) Muscular Movements. — In all animals above the unicellular forms certain cells, or parts of cells, become specially modified for contraction, thus becoming muscles. These develop into a system which produces the many types of locomotion possessed by animals. While plants as a rule are stationary, a few of them possess independent motion. Spores of many plants possess flagella or cilia; some of the lowest show amoeboid motion, and some have methods of motion not yet understood, like Diatoms and Oscillaria; Fig. 68. Among higher plants movements of different parts of the leaves, stamens, etc., are not uncommon. No muscles are developed, however, in plants, the motions being due to slow changes in the protoplasm, which are not well understood. An independent locomotion is unknown among any plants except those of the lowest orders. C. Sensitiveness. — In order to distinguish their food, animals have developed sensitiveness and sensations. Plants not needing to distinguish food so accurately have not developed much sensitiveness. D. Structure. — As a rule animals have their bodies condensed into a small compass, and are provided with an opening for taking in food, — the mouth, — which is connected with a digestive system. Typical plants, since they feed upon gases and water, which are distributed everywhere, have their bodies widely expanded into branches, leaves, and root hairs, in order to come in contact with a large amount of air and soil. They never have any mouths, since they do not take solid food, and consequently have no digestive system. Salts, of various kinds in the foods. The outgo of an animal consists of: — Carbon dioxid, excreted from the respiratory organs. Water, excreted from the skin, kidneys, and some other organs. Salts, in various excretions. After an animal has reached its full growth, the income and the outgo practically balance. With some animals this period of equilibrium lasts a long time, perhaps for years. With others, growth may continue until death comes, in which case there is never any period of actual balance. Water, from the leaves. Carbon dioxid, from the leaves and other parts. Proteids and various other substances, eliminated with dead leaves, branches, seeds, and other reproductive bodies. No Sharp Distinction between Animals and Plants. — The criteria above given are ordinarily sufficient to distinguish between animals and plants, and will separate typical forms; but when we come to consider low types, some or all of these distinctions disappear. There are, for example, many plants which have no chlorophyll (molds, toadstools, etc.), and hence have no power of photosynthesis; but they are, nevertheless, clearly plants, for no one would for an instant think of confusing them with animals, even though they do not contain chlorophyll. Some plants have independent motion, while some animals are stationary. Some plants are sensitive. The distinction of shape applies only to the higher organisms; for among the microscopic forms no distinction can be seen between the shape of animals and plants, some animals having no mouth, and some plants, as well as animals, having their bodies condensed rather than expanded. Thus it appears that each of the distinguishing characters separating animals and plants breaks down when we come to apply it closely to some of the low forms of life ; until we have to admit that there is no absolute criterion separating the two kingdoms. Nevertheless, there is rarely any real difficulty in making the distinction. It is true that there is a difference of opinion as to whether a few of the very low forms should be called animals or plants; but when we take all of the above facts into consideration, it is only in a few instances that we are unable to say positively that any given organism is either animal or plant. Most of the difficulty is confined to the microscopic forms which are among the lowest organisms, and the fact that among these there is no absolutely fixed line between the two kingdoms is of special significance as suggesting the origin of the two kingdoms from a common starting point by a process of evolution. Organisms which possess chlorophyll, and consequently nourish themselves by photosynthesis, are sometimes said to be holophytic (Gr. holos = whole + phyton = plant) . In contradistinction, organisms which have no chlorophyll and must depend upon others for sustenance are called holozoic (Gr. zoon = animal). Animals are practically all holozoic, and green plants true of all Fungi. Protozoa and Protophyta. — Both plants and animals may be found among unicellular organisms, the unicellular animals being known as PROTOZOA (Gr. protos = first + zoon = animal), and unicellular plants as PROTOPHYTA (Gr. phyton = plant) ; see Chapter III. Among such organisms there is sometimes a difficulty in distinguishing between animals and plants, since any structure of a distinctive character is lacking. Even here, however, the majority of forms group themselves in one of the two kingdoms, so that they can readily be separated. There are, however, a few forms which prove a puzzle. Euglena (Fig. 29 B)y for example, has green chlorophyll, and is thus allied to the vegetable kingdom (holophytic); but it has also the power of motion, a mouth, and a red eye-spot. Peranema (Fig. 29 A)t however, which is clearly allied to Euglena, has no chlorophyll and no plant characters (holozoic). We may, with equal justice, call both animals or both plants, or perhaps one an animal and one a plant. The bacteria (Figs. 33-35) represent another group which has been difficult to classify clearly ; and for many years after they were first studied there was a considerable difference of opinion as to where they belonged. They have a method of life much like that of animals, but their general structure, their multiplication, their division to form long chains, and an occasional formation of spores, are points much more like plants, especially the Fungi. Continued study of the organisms has finally led to the conclusion that bacteria must be regarded as plants rather than animals, associated with the group of Fungi, and considered as resembling yeast and molds. A few such organisms as these are the only ones that present much difficulty in distinguishing between animals and plants, and even these can be called animals or plants with a considerable degree of certainty. While no sharp line can be drawn, the difficulty of separating them is really not very great, and even among unicellular forms it is rare that we cannot deter- from the soil, and for the purpose of carrying on the process of photosynthesis; while animals have a structure of body adapted for taking only solid or liquid food. The difference in the shape of the animal and plant body becomes so well marked that there is no longer any confusion between them. Even though we find large groups of plants that have quite lost their chloropnyll (toadstools, molds, etc.), there is no longer any difficulty in determining that they are to be grouped with plants rather than with animals, in spite of their not having any green coloring matter. When, too, we find a plant like the sundew (Fig. 104), which captures insects by means of the hairs on its leaves, and digests and assimilates them, we call it a "carnivorous plant" (Lat. caro (carnis) = flesh + vorare = to eat), but do not confound it with animals. The Metazoa (Gr. meta = after -f zoon = animal) and Metaphyta (Gr. phyton = plant) are sharply distinct. The similarities and differences between animals and plants may be better understood if their properties are contrasted with each other in regular order. The following contrasts illustrate the distinction between these two groups : — 1. Alimentation. — In animals this system consists of a mouth, stomach, intestine, and digestive glands; food is taken into the body either as a solid or a liquid. In plants the system is poorly developed, consisting of root hairs for taking in liquids, and stomata for absorbing gases, but having no digestive organs. The foods absorbed are either liquids or gases, but never solids. 2. Circulation. — In animals circulation is brought about by a heart and blood vessels, or something corresponding to them. In plants the water absorbed from the roots ascends the stem, and passes out into the leaves by a process known as the ascent of sap, and the materials formed in the leaves are dissolved and eventually diffused throughout the plant, passing downward in certain of the cells of the stem. There are no real blood vessels, no heart, no blood, and no definite circulation. hydrates, fats, and proteids; combines them with oxygen, and, as a result, produces as waste products carbon dioxid, water, and urea. The foods are broken to pieces, and the energy thus liberated is utilized; see Chapter XV. In plants the process is primarily constructive, but there is in plant life both a constructive and a destructive metabolism. By the former the plant uses carbon dioxid, water, and nitrates, which are combined in the plant to form organic substances, like starches, proteids, etc., and in the combination solar energy is stored away. As an excretion, there are produced oxygen and water. The destructive process of plants is essentially like that of animals: the compounds built up by the first process are destroyed by the second. The total amount of construction in green plants is greater than the amount of destruction, and therefore the green plants store away organic products which may subsequently be utilized by plant life. 4. Respiration. — Animals usually have lungs or gills filled with blood ; they always absorb oxygen, and eliminate the carbon dioxid. In plants the respiration is carried on through the stomata of the leaves; when carrying on photosynthesis, plants absorb carbon dioxid and eliminate oxygen; when not carrying on photosynthesis, the gas absorbed is oxygen and the gas liberated is carbon dioxid. 5. Excretion. — In animals carbon dioxid is excreted from the lungs, water from the skin and kidneys, and urea from the kidneys. In plants there is no well-developed excretory system, although gases are excreted through the stomata, and certain other substances may pass out through the bark or through the roots into the soil. 6. Motion. — The muscles of animals develop a high degree of motion. In plants motion is very rarely developed, although it is not wholly lacking, some plants being well supplied with motile power. They do not, however, have muscles; and when they have motion, they use other forms of mechanism. bone, either internal or external. In plants the supporting structure is, as a rule, developed better than in animals, and consists of the great mass of wood or other resisting material found throughout the plant. 8. Coordination. — All animals, except the unicellular forms, have a nervous system, usually centering in the brain, which brings into coordination the various functions of life. In plants there is no coordinating system and practically no coordination of the different parts. Each part of the plant may live its life to a considerable degree independently of the others. 9. Reproduction. — The reproductive processes of animals and plants are very similar. Both produce eggs and sperms, and have a sexual reproduction; and in both there may be reproduction by an asexual method, although in animals the asexual reproduction is less common than in plants. In the higher animals the power of asexual reproduction is lost, while in even the highest plants the process of asexual reproduction has commonly been retained. In the higher members of both groups, sexual reproduction by eggs and sperms is universal. THE MUTUAL RELATIONS OF ORGANISMS The close relation of organisms to each other is evident, since all animals, as well as all colorless plants, are dependent upon green plants for their food. They vary greatly, however, in their methods of obtaining their food. 1. Autophytes (Gr. autos — self + phyton = plant). — Plants which are not dependent upon organic foods, but are able to take care of themselves by subsisting upon the minerals from the soil, together with the gases from the air, are called autophytes. These include the green plants (holophytic) only; and strictly speaking, even these plants are in a measure dependent upon others. The minerals that they absorb from the soil are available for plant life only after the bacteria and other soil organisms have acted upon them, the fertility of the soil depending upon its microscopic life. The autophytes, however, do not need organic food, and in this respect are much more independent than the other two groups. 2. Saprophytes (Gr. sapros = rotten + phyton = plant). — Plants which feed upon the dead bodies of other organisms are saprophytes. The plants usually included under this head are the Fungi* These constitute the scavengers of the world, and may be found everywhere in the soil or in bodies of water, where they consume whatever excretions of animals or plants there may be; or live upon dead roots, leaves, and branches; they live, indeed, upon various dead materials that have been derived either from animal or plant life. Such organisms are almost universally distributed over the earth, and they cause all decay and putrefaction, these two processes being the result of the destruction of organic material by Fungi. This class of organisms is ever at work around us, consuming the bodies of dead animals and plants. 3. Parasites. — Plants which live upon and feed upon other living organisms are parasites. In such cases we call the organism upon which they feed the host. Parasitism is very common among both plants and animals, nearly every species having special parasites feeding upon it. As a rule, the parasitic plants lack chlorophyll and belong to the group of Fungi. Both saprophytes and parasites are holozoic. Animals have similar relations, although in some respects they are more complicated. No animals live a life quite independent of organic food, like the autophytes, since they lack chlorophyll. The great majority of animals are called free-living, but they feed upon dead organic material (vegetable or animal food), and in this respect resemble saprophytes. Quite a large number of animals also feed upon a living host, and are consequently parasites. Symbiosis Among both animals and plants, however, we not infrequently find different individuals associated and living in mutual relations which may or may not be those of parasite and host. The term symbiosis (Gr. sun = with + bios = life), which may refer to either animals or plants (literally meaning living together), is applied to a variety of relations where two organisms live in close relation to each other, and is in contrast to free-living conditions where organisms live separately from others. The purpose of symbiosis is not always the same. Sometimes it is to the mutual advantage of both members; sometimes it is to the advantage of one and the detriment of the other, in which case it becomes parasitism. In accordance with the relation of the two members of the group, svmbiosis may be divided into several types as follows : — MUTUALISM A hermit crab cr, lives in the shell of the snail, sn, and an anemone, an, fastens itself to the outside of the shell. Both animals are benefited. dogs, and the human race. Among lower animals the association of a hermit crab with a sea anemone is an illustration; Fig. 105. Here the anemone gains an advantage from being carried to and fro, while the the little nodules on the roots of plants like peas and beans. If the roots of peas, beans, clover, or similar plants, be carefully removed from the soil, they will usually be found covered with little nodules ranging in size from the head of a pin to a large pea. These are found to be produced by bacteria which enter the roots and grow and multiply in their tissues. But the association is mutually advantageous. The bacteria are useful in collecting nitrogen from the air which the pea utilizes for its own benefit; and, on the other hand, the bacteria get the benefit of a lodging place and nourishment in the roots of the tubercle, and therefore are themselves benefited by the association. Commensalism. — In commensalism (Lat. cum = with + mensa = table) the two organisms live together without noticeable advantage or disadvantage to either. As an example, may be mentioned the small crab that lives in the oyster shell, doing no injury to the oyster and gaining no special advantage. Various vines which cling to trees offer another example. Some of these vines force their rootlets into the tissues of the tree and do it injury; these are true parasites. But other vines simply use the tree for the support of their weak, climbing stem, and neither plant is particularly benefited or injured by the other, except that the vine is enabled by its climbing habit to send its leaves up into the sunlight. Parasitism. — In parasitism the mutual relationship is such that one individual is benefited at the expense of the other. The host is always injured, while the parasite is benefited. Among parasites we recognize two types. Ectoparasites. — Parasites that live upon the outside of their host are ectoparasites. As a rule, they are not very harmful, though they may be so. Among them are some in which a parasitic life is only a part of their existence. In a second class, like the bedbug, the animals live wholly upon the nutrition from their host, but do not attach themselves to the host permanently. A third type, like the lice, lives wholly upon its host and has no life apart from it. While these ectoparasites may be troublesome, they are not especially injurious, except when they transmit disease germs. Endoparasites. — Parasites that live within the body of the host are endoparasites. They are numerous and produce far more mischief than ectoparasites. Among them are those that produce various deadly diseases like trichinosis (Fig. 108), tuberculosis, diphtheria, etc. The Effect of Parasitism Parasitism occurs among both animals and plants. The number of species of parasites is very great, but cannot be estimated. Nearly all species of animals and plants have their own parasites, and some have several species of parasites infesting them. For this reason it is sometimes stated that there are at least as many species of parasites as there are species of non-parasitic organisms. The effect of the parasitism upon both host and parasite is profound, but naturally quite different. Upon the Host. — The parasite usually injures the host and is then spoken of as pathogenic (Gr. pathos = disease + -geneia = producing). The amount of injury varies widely. In some cases, the parasite produces disease and even the death of the host. Trichina is a parasitic worm (Fig. 108), which occasionally causes trichinosis in man, resulting sometimes in death. Certain flies occasionally make their way into the skull cavities of cattle, producing serious and fatal brain disease. Malarial organisms (Fig. 25) live as parasites in hiiman blood and produce malaria. Various parasitic bacteria produce serious diseases in man, as typhoid fever, tuberculosis, diphtheria, etc. The same is true of plants. The various wilts, rusts, and blights are serious plant diseases, frequently spreading from plant to plant, and producing death and destruction of the host. AH are produced by parasites growing in the plant tissues. Fungi of various kinds are the cause of the greater number of plant OF CURRANTS Produced by the parasitic fungus (Gleosporium) . Most of the currants have dropped from the stem and the rest are rotted. diseases; Figs. 109 and 110. In other cases, the effect upon the host is far less serious. Some parasites may live upon a host without seriously affecting it. For example, a number of bacteria live in our intestines; they may be called parasitic, since they dwell within a living host; but instead of being injurious, some of them are beneficial to our life, and therefore are not true parasites, according to the definition given above. Between these two extremes are many intermediate grades. As a yule, parasitism injures the host, and indeed, strictly speaking, parasitism is a term that should only be used when one animal or plant feeds upon another, to the distinct detriment of the latter. Upon the Parasite. — The effect of parasitism upon the parasite itself is no less profound than its effect upon the host, but it is of a totally different nature. The general effect of parasitism is to cause degradation of the parasite. It is a general law of living nature that any organs which are not used, inevitably begin to degenerate. If an animal becomes a parasite upon another, it shows a general tendency to lose many of its original characters. For example, the tapeworm has become parasitic in the intestines of animals. Here it finds its food already digested by the digestive juices of the host; it has thus no need of a mouth, of digestive organs, or of any power of motion; and, in conformity with the above law of nature, having no need of these functions, it has lost them. The tapeworm has thus become degraded to a very simple organism, without digestive organs and with all of its systems of organs reduced to the lowest possible condition. Thus, parasites, depending as they do upon their host for their nourishment, lose their power of independence and become degraded. This is a biological law of great significance, — the law that failure to use any function results in its loss, — running through the whole scale of nature. It is exemplified in the human race in numerous aspects of civilized life, where one class of people depends upon another. In our highly organized cities this principle of loss of power as a result of disuse is as well illustrated as it is among animals, since in the city individuals are so mutually dependent that each one has practically lost his ability to live by himself unaided by others. The principle of the loss of function by disuse is one of the most fundamental and significant of the laws of nature. Construction and Destruction. — From a general survey of the facts which have thus been explained, it will be seen that there is a grand cycle in nature, in which the life of animals and plants is concerned. All organisms need food, and the only explanation of the fact that the food supply has not long since been exhausted is the fact that the same materials have been used over and over again, passing from plants to animals and from animals to plants. The chemical processes going on in the living world are of two types: those of construction (synthetical), by which complex substances are built out of simple ones; and those of destruction (analytical), by which the complex materials are reduced to simpler ones. Green plants growing in sunlight manufacture starch out of the simple ingredients which they extract from the soil and the air, utilizing sunlight as a source of energy for this purpose. Though they are building up these materials primarily for their own life, they build more than they need, so that there is a large surplus. This surplus is utilized by animals and by the colorless plants. It is taken into their bodies as food, and serves them as a source of energy, as well as material out of which they can manufacture new substances, and grow. Eventually the material is broken to pieces in the animal body and reduced once more to a simpler condition. In this way animals utilize as food a part of the surplus manufactured by green plants, consuming the surplus of proteids, starches, etc. But other materials made by the plants, like wood and leaves, do not so readily serve as food for animals. These materials must usually be broken down into simpler compounds, or the substance of which they are made would not get into a condition where it could again be utilized. This seems to be the special function of the Fungi. The Significance of the Fungi in Nature. — Special emphasis must be given to the significance of the Fungi in these destructive processes. In order that nature's processes may continue indefinitely, all kinds of material that have been built up into organic compounds by the green plant must be pulled to pieces again so as to be brought back into the simple condition in which the future generations of plants can utilize them. While animals use and break down much of the proteids, starches, and fats, there are some substances that animals cannot utilize, and the Fungi are necessary to reduce these substances to a simpler condition. Bacteria everywhere in nature are constantly feeding upon many kinds of organic substances, but primarily upon those that contain proteids or other nitrogenous compounds. The yeasts have a special relation to sugar; most of the sugars made by plants, and not otherwise used, are consumed by yeasts in fermentation and are thus brought back to the original condition of carbon dioxid and water. Bacteria and yeasts as well as animals thus feed upon the same substances. But there is other material of harder nature, like wood and leaves, which does not serve as food for animals nor to any great extent for bacteria or yeasts. The molds, mushrooms, and tree fungi seem to be especially designed by nature to attack these hard materials and reduce them to a condition in which they can be destroyed. These larger fungi consist of a mycelium of delicate, branching threads. If one of these plants starts to grow on the trunk of a tree, the mycelium pushes its way through the bark and in among the wood fibers, and eventually grows through the whole substance of the tree, the part visible on the outside of the trunk being only the spore-producing portion that has come to the surface to distribute the spores to other trees. The mycelium, while growing within the wood, produces certain substances which soften the wood and in time disintegrate it, i. e., cause it to rot. A tree attacked by one of these Fungi in time becomes soft and so changed in its chemical nature that it can be utilized as the food of some insect. Eventually the trunk of the tree is converted largely into a soft, pulpy mass, until finally it is wholly decomposed. Its carbon and hydrogen unite with oxygen, forming CO2 and H2O, which pass off into the air or sink into the soil, while the other ingredients are incorporated with the substances of the soil to form food for the next generation of plants. The Fungi thus have the extremely important function of bringing back into a primitive condition much of the material manufactured by plants which otherwise could not readily be disposed of. When we consider that bacteria are nature's agents for decomposing proteids, that the yeasts act in a similar way upon carbohydrates, and that the larger Fungi attack the great mass of vegetable material which is otherwise beyond the reach of animal life, we can see that the group of Fungi is of immense significance in nature. They form a connecting link between the products of one generation of plants and the next. Without their agency, organic material — proteids, fats, starches, leaves, woods, etc. — would accumulate, and in time vegetation would cease, because the earth would be covered with the remains of past generations, which would crowd life out of existence. The Fungi thus act as scavengers, cleaning up the surface of the earth and rendering nature's processes continuous by ever returning to the soil the ingredients upon which subsequent generations can feed. The Food Cycle Complete. — Thus, as the result of the action of the Fungi and of animals, all of the surplus starch and sugar, all the fat, proteids, wood, and cellulose, and indeed all other materials which have been built up by the constructive processes of plants, are eventually broken down, and in the end reach a condition like that from which they started. Carbon dioxid and water are produced, as well as nitrates and certain other mineral salts. The carbon dioxid, being a gas, flies off into the air to join the store of this gas in the atmosphere; the water evaporates or sinks into the soil; and the nitrates and other mineral ingredients also find their way into the soil. These ingredients, again within reach of plant life, are seized by the green plants and built up into a new generation of plants to make new starch, sugar, proteids, etc. The ingredients which feed one generation of plants may, after combination in the plant body, nourish a generation of animals, eventually returning to the same conditions as those from which they started. The cycle is thus complete, and there need be no danger of exhaustion of the food supply as long as it is possible for the same materials to be used over and over again by green plants, animals, and fungi GENERAL TYPES OF REPRODUCTION THE process by which reproduction is brought about is always fundamentally the same. In spite of all of the numerous modifications of the method in different animals and plants, they are all reducible to some form of division; the original animal or plant divides itself into parts, each of which is capable of growing into an individual like the one from which it came. The numerous varieties of reproduction may be grouped together under two general types. In one of these the original organism divides itself directly into two or more parts by simple division. In the other the division is always complicated by the union of two parts with each other. In the latter case certain cells of the original organisms unite with each other, and the union is followed by a rapid division of the cells. The two types of reproduction are, therefore, (1) Division unaccompanied by cell union and (2) Division accompanied by cell union. The type of division in which cell union is found is often spoken of as sexual reproduction, and the uniting cells are the sex cells; the type in which the division is not accompanied by cell union is called asexual reproduction. REPRODUCTION IN UNICELLULAR ORGANISMS Simple Division. — All of the single-celled animals multiply by the process of simple division; Figs. 19, 23. A careful study of the internal changes that are going on in the celk during this reproduction shows that they are essentially identical with those described on pages 85-89. In other words> there is a division of the chromatin material in the nucleus, followed by the formation of two nuclei, which again is followed by the division of the cell into two parts. After having SEXUAL AND ASEXUAL REPRODUCTION 239 thus divided and separated from each other, each of the individuals grows until it is ready to divide, and so the process goes on repeating itself. In most unicellular plants, the method of reproduction is essentially the same. Figure 30, for example, shows the reproduction in Pleurococcus, and Figure 33 in ordinary bacteria. These latter plants are so small that we cannot determine the internal changes that are going on, but can only see that the individuals elongate and then divide in the middle, into two parts. Recent study, however, seems to suggest that the changes are essentially like those occurring in the Amoeba, and at all events the process of reproduction is nothing more than the process of division. The reproduction of yeast by budding (gemmation) is only a modification of division; Fig. 32. The internal changes are essentially like those in the reproduction of the Amoeba or Paramecium; the first step is the division of the nucleus into two, one of which passes out of the original cell into the bud, while the other remains in the original cell. Thus, when the two cells separate, each has a nucleus that has come from the original nucleus, and, while the details of the process are somewhat different, it is as truly a cell division as in the other examples. Nearly all of the unicellular animals and plants show one of these two methods of reproduction; see Fig. 111. Reproduction by Spores. — When the organism breaks up into many parts, they are called spores. Examples of this we have already noticed among the unicellular organisms. In the yeast (Fig. 32 s), spores are formed within the yeast cells under some conditions; and Figure 25, which shows the life history of the malarial organism, indicates that one part of its history, namely, the cycle in the human blood, is an illustration of spore formation. In the malarial Plasmodium the spore formation which occurs in the human blood alternates with a second type of spore formation in the body of the mosquito. This last process is, however, associated with celi union, as shown in Figure 25 j. Among unicellular animals with a cell union, as in Plasmodium. Among bacteria there is a spore formation of a peculiar kind. Here, as shown in Figure 33 E, each bacterium produces a single spore only, instead of several, and the spore formation is really not a form of multiplication. The cells formed are, however, called spores, although their function seems to be to resist adverse conditions rather than to reproduce the organism. They have resisting walls and are capable of developing into new individuals, thus agreeing with other spores except in the fact that one only is produced in a cell. Reproduction by Cell Union among Unicellular Organisms. — The process of cell division among single-celled organisms may continue for a long time, producing an indefinite series of offspring. Whether in any case this kind of division can really go on indefinitely we do not positively know. There are some organisms like yeast and bacteria, in which we have reason for suspecting that cell division may go on indefinitely if proper conditions can be maintained, and in which, up to the present, no trace of any other kind of reproduction has been found. It is believed by some that even animals like Paramedum, which conjugate occasionally, may, if proper conditions be maintained, go on dividing indefinitely. Whether this is true or not, it is certain that under ordinary conditions cell division in time becomes slower, and in Paramedum it has a tendency to come to an end, unless it is reinvigorated in some way. In nature such an invigoration is brought about by a fusion of cells with each other as already described; see Fig. 23, page 64. It is probable that in most other unicellular organisms a similar cell union occurs under some conditions. As already described, it occurs in the malarial organism in the cycle that takes place in the mosquito; Fig. 25 j. The cell union that takes place is a true sex union, since there is a clear distinction of male and female cells. While such a union of cells has by no means been found in ail unicellular organisms, it has been found in many, and we know that it is quite widely distributed. The studies of recent years particularly have shown one large group of unicellular organisms called the Sporozoa, which live as parasites on various hosts, and show a cell union resembling that of malaria. Another example of this will be given here in illustration of the phenomenon of cell union among single-celled animals. Monocystis. — In the earthworm may be found living a unicellular parasite known as Monocystis. This animal (see Fig. 112 A) is a single elongated t cell possessing a nucleus, but with no other visible organs. The animal has no locomotor organs, although it does have a slight power of motion. Its method of reproduction involves a cycle, in which a cell union alternates with a formation of spores without cell union, but in a complicated manner. When ready to multiply, two individuals fuse with each other and become surrounded by a covering or cyst; Fig. B. Inside of this cyst both of the individuals divide. First the nucleus divides into many parts (see Fig. C), and later the rest of the protoplasm divides and collects around the pieces of the divided nuclei, thus making many small cells. Now the new cells from one of these individuals unite in pairs with the cells from the other. This step occurs within the cyst, but is shown separated from it in Figure Dj a, by and c, and it constitutes the cell union proper. When the cells fuse together their nuclei unite, forming a single nucleus, c, called the fusion nucleus, which divides into eight parts, at e, after which the whole cell divides into eight elongated cells (see /) known as sporozoites. Meantime a hard shell is produced around the eight sporozoites and the whole cluster of eight is called a sporoblast. All of this has occurred within the original cyst, which has by this time become filled with a large number of these sporoblasts, each with its eight A, the full-grown animal; B, two individuals enclosed in a cyst; C, the division of the nucleus into a number of parts, the protoplasm not yet divided; D, successive stages of the fusion of thfe cells which result from division of the two animals in C; F, the cyst containing numerous sporoblasts; G, shows the sporoblast breaking open to allow the spores to emerge, which develop into adult animals. The stages represented in G occur only when the animal •caches another earthworm. sporozoites within; see Fig. F. Eventually the cyst breaks open, allowing the contents to escape. Later these sporcblasts themselves break open and the individual sporozoites come but ready to grow into new animals like the original Monocystis; Fig. G. These latter stages do not occur unless the sporozoites find their way into another earthworm, where they live as parasites until ready to multiply again. The sporozoites are evidently spores, but they arise from the division of a mass resulting from the fusion of two reproductive cells; and to distinguish them from other spores they are called sporozoites. By comparing this history with that of the malarian Plasmodium, it will be evident that the spores of the latter, which are formed in the body of the mosquito, must be sporozoites, since, like those just described, they arise from the breaking up of the mass of the two cells which have united by cell union. Monocystis as here described shows no spores which correspond to those that appear in the human blood; Fig. 25 g and h. REPRODUCTION IN MULTICELLULAR ORGANISMS Multicellular organisms have the same two general types of reproduction as found in the unicellular; namely, simple division, and division accompanied by cell union. DIVISION WITHOUT CELL UNION Multiplication by Simple Division. — Simple division among multicellular organisms is more common among plants than among animals; and excellent examples of it are familiar to all. Many of the lower plants, like liverworts, multiply by the formation of buds called gemmae, which break away from the original, and form new plants. Even among the higher plants the same general method is found. If one of the branches of a weeping-willow tree is broken off and stuck into moist ground, it will take root and grow into a new tree. Indeed, we can cut the branches of a willow into practically as many pieces as we wish, and find each one is capable of taking root and growing into a new tree. The same thing is true of most ordinary plants, for, with a few exceptions, trees and smaller plants may be reproduced indefinitely by breaking off their branches and putting them into the proper conditions for taking root. While a few plants fail to show this power, it is a character found very commonly in the vegetable kingdom. Many plants normally multiply upon a similar principle. The strawberry plant, for example, sends out branches which grow for some distance, and then their tips strike root into the ground and a new plant springs up, united with the old one at first by a connecting branch; Fig. 113. Among animals this method of reproduction is not so common as in plants and is confined to the lower species. One example has been already described in Hydra; see page 146. pieces, each capable of producing all of its lacking parts; but this power is retained in diminishing degree as we go from lower to higher animals. The earthworm does not ordinarily multiply by simple division, but if it is cut into two pieces by accident, each will develop the lost parts and two animals will result. In some worms, related to the earthworm, this method of multiplication by division, each piece developing all of the lost parts, is a normal method of reproduction; Fig. 114. Reproduction by Spores. — Reproduction by means of spores is also found among the multicellular organisms, especially among the multicellular plants. A few illustrations of it are the following. — Examples of spore formation in molds have already been described (page 97), two methods having been mentioned. In Mucor (Fig. 42 E) the spores are produced within a sac called a sporangium, while in Penidllium (Fig. 42 A) they are only the ends of branches, growing in the air. The latter are called conidia to distinguish them from spores formed in sporangia. The nature and function of spores and conidia are the same. Another well-known illustration of the same is the common puffball. This is a colorless plant, growing from a mycelium which lies chiefly below the surface of the ground. At certain seasons of the year there arise from the mycelium, rounded knobs which vide into millions of spores, and after they have been properly matured an opening appears at the top and the spores emerge in the form of a fine dust. The slightest touch upon the puffball will throw masses of dust into the air, from which arises the name puffball. This dust consists of millions of minute spores, each of which can become a new plant. plants, occurring in the lower as well as in the higher. Even in the flowering plants the pollen of a flower is really a mass of spores, although their relation to the growth of the plant is different from that of the spores to the puffball, since they do not grow immediately into a plant like the one that produces them. Among the multicellular animals, the production of spores is not found. There is, however, in a few animals a method of reproduction, called parthenogenesis, which in some respects resembles spore formation. The essential differences between reproduction by spores and that by eggs is that a spore grows into a new organism without being united with a sperm, i. e., no fertilization is required (see page 267), while an egg must combine with a sperm in order to be capable of growing into a new organism. Some organisms, however, produce eggs that can grow without fertilization. Among the best-known examples of this is the honey bee. The female bee produces true eggs, some of which unite with sperms, while others develop without such union. The individuals produced from the unfertilized and from the fertilized egg are different, the fertilized eggs producing worker bees or females, and the unfertilized eggs producing males (drones). So far as can foe seen the eggs are alike, the only difference between the eggs that produce workers and those that produce males being that one is fertilized and the other not. This phenomenon of the development of eggs without fertilization is called parthenogenesis (Gr. parthenos = virgin + genesis = creation) . It resembles reproduction by spores only in the fact that it consists of a single cell developing into an adult without the necessity of union with a sperm; but the reproductive bodies are identical with eggs, and it is usually described as reproduction by eggs which do not require fertilization. Parthenogenesis occurs in a variety of animals with various complications. Where it occurs it is most common to have such a parthenogenetic reproduction alternate, with more or less frequency, with sexual reproduction. In the microscopic Animal Hydatina, for example (Fig. 116), found in fresh water, the eggs commonly produced, called summer eggs, develop without fertilization into new females, which rapidly mature and produce more similar eggs that develop in the same way. This may go on for a long time, under proper conditions for hundreds of generations, without any males making their appearance. Eventually, however, under conditions not yet understood, males make their appearance and the females produce eggs of a different kind, called winter eggs, which are incapable of developing without being combined with sperms by the sexual process. Here, then, parthenogenesis seems to be the normal method of reproduction, sexual reproduction alternating with it at unknown and uncertain intervals. The reasons for this alternation, and the conditions that determine the one or the other method, are not yet understood. MULTIPLICATION BY CELL UNION Conjugation. — In all animals above che unicellular forms, and in most plants, cell union is found as a factor in reproduction. Among a few plants of the lower orders the cells which unite are alike. In Mucor, for example, besides the spore formation mentioned on page 97, a union of cells sometimes takes place; Fig. 117. As shown in Figure A, special lateral threads grow out from the ordinary mycelium of the mold, and these come in contact with each other at their tips. After they touch each other single cells are divided off from each, B, which fuse with each other, as shown at C. This fused mass is called a zygospore (Gr. zygon = yoke + spora), z. It enlarges, becomes covered with a hard case, D, and breaks away from the plant that produced it. It may then remain dormant for a long time, but eventually it sprouts, E, and grows into a new plant. In this case the two cells that unite are, so far as the microscope discloses, alike, and the plants that produce them appear identical. But careful study has proved that there is a difference in the uniting plants, shown not in their shape, but in their uniting powers. It has been found that there are two types of Mucor, differing only in their power of uniting with each other. For example, in Figure A, the two different mycelium threads are marked x and y. It is found that while outgrowths of x can unite with outgrowths of ?/, they can never unite with other outgrowths of the mycelium x. There are thus two different types of plants, each capable of uniting with the other, but not capable of uniting with outgrowths from itself. This reminds us of sex union, where an egg will unite with a sperm but not with another egg. It cannot be called true sex, however, since there are no distinguishable differences between the uniting bodies. It is thought to be a first step toward the true sex which is developed in higher plants. Since the uniting bodies in Mucor are, so far as can be seen, alike, the union is called conjugation. found instead. Fertilization or Sex Union. — The eggs of all organisms consist of single cells which have prominent nuclei; Fig. 118. Eggs are usually rounded in shape, although they may vary. In size they range all the way from eggs that are too tional to the size of the animal that produces it. The human egg, for example, is microscopic, and the egg of the hen is gigantic in comparison. In large eggs, like those of the hen or the ostrich, the bulk of the egg is made of food material, sometimes called yolk, or deutoplasm (Gr. de^teros = second + plasma = substance), deposited within the eggshell for the nourishment of the young which is to be developed. The egg has a thin cell wall which is known as the vitelline membrane. The eggs of animals are produced in organs called the ovaries; Fig. 119. They are situated in different parts of the body in different animals, and their sole function is to produce eggs, which are then carried to the exterior through ducts called the oviducts. As can be seen from Figure 119, the egg is really a single cell, like the other cells of the body in structure, though larger in size. As the egg passes along the oviduct it is not infrequently surrounded with a mass of yolk and a shell; neither the yolk nor the shell is an essential part of the egg, the yolk being a food material for the nourishment of the embryo, and the shell being a covering to protect the egg after it has left the body. unite with the eggs in order that the latter may be capable of further development. Sperms are by no means uniform in shape. As a rule, each consists of a minute head and a motile tail, whose lashing movements propel the sperm through liquids until the sperm is brought in contact with the egg. Figure 120 shows the sperms of a number of animals and plants. There is great variety among them, and, while some of them are provided with tails, others are not, and, although usually motile, the sperms of some animals are stationary. The sperms of animals are produced in special glands called spermaries or testes. In the frog and earthworm the position of these sperm glands is shown in Figure 80. The sperms are passed from the spermary into ducts, commonly known as the vasa deferentia, which carry them to the exterior. These ducts may be very short or they may be long and coiled. Sperms are much smaller than eggs, the sperm being always microscopic. Plants also produce sperms (Fig. 120 G), though they do not come from spermaries or special sperm ducts; see page 271. Males, Females, and Hermaphrodites. — When reproduction in animals or plants is brought about by eggs and sperms, the process is spoken of as sexual reproduction and the uniting bodies, the eggs and sperms, are sex bodies. The glands that produce them are the sexual glands, or gonads, and the ducts that conduct the bodies to the exterior are the sexual ducts. Among animals, it is most common to have one individual produce either spermaries or ovaries, but not both, and the individuals are then spoken of as males and females.* In some animals, however, as already seen in the earthworm, the same individuals may produce both spermaries and ovaries. Such individuals are spoken of as hermaphrodites. Among animals hermaphrodites are found chiefly among the lower orders, very few being found among the higher. Among plants, however, both hermaphroditic and separate sexed conditions are common; hermaphroditic plants are called monoecious (Gr. monos = one + oikos = house), and the separate sexed plants dioecious (Gr. di- = twice -f- oikos). In the higher flowering plants the relation of the sexes is peculiar, and complicated by what is called alternation of generations, to be described later. THE UNION OF THE SEX BODIES OR FERTILIZATION The union of the egg and the sperm is called fertilization, and the moment when the egg and the sperm unite is the beginning of the life of the new individual. This process of union of the sex bodies is peculiar and of extreme significance. In the description which follows, the successive changes which occur are described without reference to any particular spe- cies. Essentially the same series of events occurs in all animals where a fertilization takes place, although the order of events is not always the same. In a previous chapter we have seen that in all animals, when the chromatin of the nucleus breaks into chromosomes before division, the number of chromosomes is always the same in all cells of the species. In order to illustrate the process of the origin and union of the sex cells, we will describe the process in an animal that has four chromosomes, meaning by this that all of the cells of the animal (except the germinal cells to be described) contain four chromosomes at the time when cell division takes place. Origin of the Egg (Oogenesis). — The egg is simply one of the ordinary cells of the ovary. During the early life of the animal, the cells in the ovary increase by the ordinary process of cell division, with nothing especial to distinguish it from the cell division of the other cells. In all cases, the cells are about the ordinary size and all contain the normal number of four chromosomes. This process continues indefinitely during the early life of the animal, until it is ready to produce eggs. When this time comes, some of the cells of the ovary begin to increase greatly in size, and become in a short time very much larger than the ordinary cells, not only than the cells of the body generally, but much larger than all of the other cells in the ovary. This increase in size is due largely to deposition in the egg of food material which is to serve as nourishment for the young that is subsequently to develop from the egg. At the time the egg increases in size, a peculiar change takes place in the chromosomes within the nucleus. By a series of divisions, this chromatin divides into a number of chromosomes which is always double that found in the ordinary cells of the animal. In our illustration, instead of four of these chromosomes, there are eight. These chromosomes always assume at this stage the arrangement in groups of fours, such as is shown in Figure 121 A. There is thus produced a large primary egg (Gr. don = egg-fci/tos), called an oo'cyte, containing AN EGG Stages A to G represent maturation; H and I the fertilization; J, the egg after it has divided; /, female pronucleus; ra, male pronucleus; p, polar bodies; sp, a typical flagellate sperm more highly magnified. the two nuclei once more dividing into two parts without any splitting of the chromosomes, each of the four nuclei thus containing two of the original chromosomes. Half of the nucleus still within the egg is extruded, while the other half remains within; Fig. 121 E, F. The nuclei which are thus extruded from the egg are called polar cells, p, and have no further function, since they have nothing to do with the individual which is to arise from the egg. They are rejected products and soon disappear. After the nuclei have divided the second time, the nucleus remaining within the egg, with its two chromosomes, once more passes toward the center of the egg and is called the female pronucleus; Fig. G, f. The egg is now ready to unite with the sperm. The egg, in other words, has become mature, this process of the extrusion of the three small nuclei being the essential feature of the process of maturation. The Origin of the Sperm (Spermatogenesis) . — The origin of the sperm is essentially similar to that of an egg, differing, however, in one rather important point. As in the ovary, the ordinary Cells in the sperm glands, during the early life of the animal, continue their growth and division by the process of simple cell division, with the normal method of the division of the chromosomes. When, however, the sperms are about to be formed, the cells of the spermary undergo a change similar to that described in the formation of the egg, except that they do not materially increase in size. In each of these cells, called a spermocyte (Gr. sperma = germ + cytos), the number of chromosomes doubles itself, producing a number identical with that found in the oocyte; Fig. 122 7. The chief difference between this spermocyte and the oocyte at the corresponding stage is that, whereas the egg has greatly increased in size by the deposition of the food, the cell which is to form the sperm does not increase in size. The next step in the development of the sperm is the division of this cell into four parts. This step corresponds clearly with the division of the egg cell into four parts, as shown in Figure 122 // to ///. In this case, however, the division does not produce one large and three small cells, but four cells of equal size, each one of which receives two of the chromosomes. It is evident, therefore, that one of these cells is equivalent to FIG. 122. — DIAGRAM SHOWING A COMPARISON BETWEEN THE MATURATION OF AN EGG, B, AND THE FORMATION OF THE SPERMS, A Stages / to IV in series A and B correspond with each other. one of the cells developing in the maturation of the egg, at least so far as concerns its nuclear matter and its chromosomes, differing, however, in the amount of cell substance that may be present. In the further development we find another point of difference in the fact that each one of these four cells develops into a perfect, functional sperm. In the maturation of the egg, three out of the four cells are thrown away and take no further part in the functions of the animal; in the development of the sperm, however, each one of the four cells arising from the divided spermatocyte cell becomes a typical sperm; Fig. IV. It is evident from this that a sperm must be regarded, so far as concerns its nuclear matter, as equivalent to a matured egg, and equivalent also to each of the three discarded cells which have been thrown away in the maturation of the egg. Both the sperm and the egg contain half the normal number of chromosomes. sometimes rounded, but more commonly elongated. A careful examination of this head shows that it contains an equivalent of the two chromosomes originally present in the matured egg. The spermatozoan head is therefore really a nucleus. Just back of the head is a short piece known as the middle piece, which contains a centrosome. This is the smallest part of the sperm. The third part of the sperm is the tail, which is usually rather long and motile, and whose only function is to produce motion of the sperm and thus bring it in contact with the egg. The sperms of some animals, however, have no motile tail and are brought into contact with the egg by other means. The important conclusion to be drawn from this description of the origin and structure of eggs and sperms is, that they are essentially equivalent to each other. Even though the egg is very large and the sperm is very small, and though the egg is motionless and the sperm is commonly endowed with motion, so far as concerns, their most essential parts they are identical. Each contains one nucleus, with chromosomes equivalent to half the amount present in the ordinary cells of the organisms from which these cells were derived; each may contain a centrosome, though this is not always found. The eggs contain food upon which the young embryo feeds, and the sperm possesses a tail by which it can swim; but these are secondary features, and in essential characters the egg and sperm are identical. Entrance of the Sperm into the Egg. — When the sperms are mature they are excreted through the ducts of the spermaries to the exterior. If not excreted into the water, as is frequently the case with water animals, a quantity of liquid is sometimes excreted with them, in which the cells can swim by their motile tail. All organisms have some method by which the sperms and eggs are brought together. Sometimes both of them are thrown in large numbers into the water and depend upon chance currents to bring them together. Among many of the higher animals there are developed special. copulatory organs, whose function is to bring the eggs and sperms together. Among the endless series of animals and plants may be found great variety in the manner by which this is accomplished; but in all cases some efficient device is found for bringing the egg and sperm into contact. The egg and the sperm have a strong attraction for each other, so great that when brought into each other's proximity the sperm will be attracted to the egg and attach itself. The head of the sperm then buries itself in the egg, as shown in Figure 121 G, m, the tail being left on the outside, but the centrosome being carried in with the head. The tail has no further function. This entrance of the sperm into the egg may occur either before or after the changes in the egg that have been described as maturation. If the sperm enters before the egg is fully matured it remains in the egg in a dormant condition, and is now known as the male pronucleus, until after the egg has been brought into the condition above described as mature, with its chromosomes reduced to half their normal number. If the sperm does not enter the egg until after the egg is mature, the further changes which bring about fertilization occur at once. Fertilization. — After the sperm has entered the egg and the egg has become matured, the nucleus of the egg and the sperm head (the two pronuclei) approach each other; Fig. 121 H. What brings them together is not exactly known; apparently, in some cases, the centrosome seems to have something to do in bringing the two nuclei in contact, and without much doubt they have an attraction for each other. This fusion is the fertilization proper (sometimes called impregnation). Since the egg nucleus contains two chromosomes and the sperm head, or male nucleus, also contains two, when these two unite the fusion nucleus evidently contains four of them, and thus the number of chromosomes is restored to the same number as that possessed by the ordinary cells of the body of the animal. Whether the centrosome that is brought in by the sperm and that which comes from the egg have anything to do with the subsequent history of the fertilized egg, is uncertain. In some cases it is certain that the ^centrosome of the original egg disappears, and the only one that remains is the one brought in by the sperm. In plants, as we have already learned, there are no centrosomes at all, and from these facts it would seem to follow that the centrosome can not have very much to do with the process of fertilization. From the facts given it is evident that the fertilized egg contains material from both parents. The female parent furnishes the bulk of the food in the egg upon which the young is to be nourished; and it also furnishes two chromosomes. The male parent has also furnished two chromosomes, and in some cases a centrosome, but none of the food material. The only thing which the two sexes have furnished in common is chromatin material, and it is especially interesting to note that both the male and the female parent furnish chromosomes in equivalent amounts. Unless an egg is fertilized by a sperm it has no power of subsequent growth. Most of the ordinary cells of the animal body are capable of a certain amount of development, but the egg cell if unfertilized soon dies, undergoes decomposition and disappears. The sperm cell also is unable to undergo any development by itself. Therefore, the fusion of an egg and a sperm is necessary, in this type of reproduction, for the development of a new individual. It may sometimes happen that more than one sperm is brought into the vicinity of an egg. When this occurs, in most cases there is some device by which the entrance of more than a single sperm into the egg is prevented. In some kinds of eggs, it is, however, not unusual for more than one sperm to enter the egg, but when this occurs only one of them unites with the egg nucleus, the others having no further function in the process. If in any case more than one sperm does unite with the egg nucleus, abnormal results arise and no proper embryo develops. In the vast majority of cases, however, the single sperm unites with the single egg nucleus, and all other sperms that chance to be present have nothing to do with the development, but soon disappear. THE RELATION OF THE CHROMATIN TO HEREDITY The facts just mentioned show us that the chromatin must play a very important part in the transmission of characters from parent to offspring. It is a demonstrated fact that both the male and the female parents can transmit their characters equally to their offspring. It follows that both parents would probably transmit an equal amount of hereditary substance to the next generation. The process of fertilization just described shows that the only parts contributed by the male parent to the fertilized egg are the centrosome and the chromosomes. Hence whatever the male parent transmits to its offspring must be contained either in the centrosome or the chromosomes. But the female parent does not contribute any centrosome to the combined egg, and it should be remembered that in plants there is no centrosome. The female does contribute an amount of chromatin equal to that which the male contributes, namely, in the case described, two chromosomes. This fact proves that the chromosomes must certainly contain hereditary material. These chromosomes are extremely minute, far below the reach of the human vision and only seen with a high-power microscope and by special microscopic methods. It seems almost incredible that there can be in such a small compass the traits of characters which an individual transmits to its offspring and which the offspring inherits from its parents. But the facts described seem to be capable of no other interpretation, and we are therefore justified in saying that the chromatin material is the bearer of heredity. This does not necessarily mean that other parts jf the egg and sperm may not have some share in heredity. The methods of maturation and fertilization differ somewhat in different animals and plants, but in all cases where there is the union of the egg with the sperm it is essentially as above described. The normal number of chromosomes is first doubled and then reduced to one-half that which the ordinary cells of the organism originally contained. The mature sperm also contains half of the normal number of chromosomes; and thus, when the egg and the sperm finally fuse, the nucleus of the fertilized egg is always brought back into the original condition with the normal number of chromosomes, which is evidently always an even number; see page 85. It may seem a little strange that the egg should exclude and throw away as useless such a considerable part of this chromatin material, which must be of such great value. The reason is not difficult to see. If the egg did not throw away some of its chromatin material, it could not combine with the sperm without the chromatin material in the combined egg being doubled in quantity. If, for instance, in the case de* scribed, the egg and sperm should retain their normal number of chromosomes, then, after the egg and sperm united, the nucleus of the fertilized egg would contain eight instead of four, and all of the subsequent cells would necessarily contain, eight. If the process were repeated at the next reproduction the number would again double and thus the amount of the chromatin material in each cell would become greater, generation after generation. To keep the number of chromosomes the same in successive generations, both the sperm and the egg throw away some of their chromatin to make room for an equal amount brought in by the other cell at fertilization. Why the number is first doubled before being reduced is not clear. THE PURPOSE OF THE UNION OF THE SEXES Since sex union is almost if not quite universal among animals and plants, it is evident that the process must be one of very great significance. One of its purposes is very evident. Inasmuch as the chromosomes contain the substance which transfers the hereditary traits, it follows as a result of this cell union that the individual that is to arise from the fertilized egg will inherit traits of character, not from one but from two parents. This will naturally produce a greater variety in the offspring. If an individual arose simply as a result of the division of a single parent, it would be expected that it would have a tendency to show a much greater likeness to its parent than if it arose from the fusion of cells from two parents, each of which possessed its own individual characteristics. Thus, as a result of this sexual union, there will be introduced into the offspring a tendency toward variety, which would hardly be expected if they were produced always by the non-sexual methods of simple division. It is believed by biologists that one purpose of sex union is to produce variety among organisms, i. e., to introduce what is technically called variation. The importance of variation will be discussed later; here it will be sufficient to say that upon the phenomena of variation is based the whole problem of the evolution of animals and plants, and therefore, without this phenomenon of sex union, the evolution of animals and plants could hardly have taken place, at least not in the form in which it has occurred in the actual history of living things. The process thus becomes intelligible. Sex union brings about the combination in the offspring, of the qualities of two parents, and thus produces a succession of generations which, though much alike, still show a certain amount of variation among themselves and hence a variation from the ancestral type. SUMMARY OF THE METHODS OF REPRODUCTION REPRODUCTION in all animals and plants is the result of division, but according to whether the division takes place with or without cell union, we have the two following types: — tilization. 2. Sexual reproduction. — Sexual reproduction is division preceded or accompanied by a union of cells, the uniting cells being called gametes. According to whether the uniting cells are alike or unlike, we find tw9 types. A. Conjugation. — When the uniting cells are microscopically identical with each other, the process is conjugation. In these cases there are neither eggs nor sperms, and the cell resulting from their union is a zygospore. Conjugation has apparently for its purpose the reinvigoration of the process of cell division, since, after two individuals have united, cell division begins to take place more rapidly. After many generations of simple cell division the process tends to become slower, and conjugation then may occur to DISTRIBUTION OF REPRODUCTIVE METHODS 26S reinvigorate the process. Conjugation occurs chiefly among the unicellular organisms. It is found also among some multicellular plants, but in no multicellular animals. cells are unlike, one being much larger than the other, their union constitutes fertilization, or true sex union. The larger of the two uniting bodies is the egg and the smaller the sperm. deed, some organisms show a type of reproduction that is halfway between conjugation and true sex union, and give us an idea as to what was probably the origin of sex. We have already studied Pandorina (Fig. 28), in which we found an animal multiplying by the union of two similar cells; but the two cells, although similar, are not exactly alike. Both are rounded cells, both provided with flagella which enable them to swim; but one is a little larger than the other, and when union occurs it is always that of a larger with a smaller cell. Whether this is a true sex union or a conjugation it is difficult to decide. A step further in the line of sex differentiation is found in Eudorina. This organism is much like Pandorina, and is composed of a cluster of rounded flagellate cells, inclosed in jelly; Fig. 123 A. They multiply by a method of simple division as does Pandorina (shown at A), and in addition they multiply by cell union. In the latter case the cells break up into many small parts, after which there is a union of cells. But here the uniting cells are very unlike. Some of the cells, shown at C, D, E, break up into a large number of small flagellate cells, of an elongated shape. The other cells of the colony do not divide, but slightly enlarge and remain spherical. Eventually one of the small flagellate cells comes in contact with one of the rounded ones and the two unite. Here there is a plain suggestion of egg and sperm, and consequently of a true mals generally. Prom such data as these it is evident that the probable origin of sexual reproduction has been something as follows: The first method of reproduction was by simple division, but the independent individuals acquired the habit of fusing with each other, as we have seen in the case of the Paramecium, this fusion reinvigorating the life power of the fused individual. Next there was probably a tendency for the cells to break up into many parts which subsequently united with each other, the parts being at first all alike. The next step seemed to be for some of these cells to contain more food than the others and become larger; this led to the larger cells having less power of motion, while the smaller ones retained the power. Next the larger cells lost their swimming flagella and were brought into contact with the smaller cells only by the motions of the latter, which still retained their flagella. Lastly, most of the cells of an organism ceased to have any share in reproduction, being simply concerned in the life of the colony. Some of the cells in such a colony, however, assumed as their part the process of uniting with others, and thus carried on the functions of reproduction. These cells still continued to differentiate into large and small cells, the large ones becoming eggs and the small ones remaining as sperms. From this time on the function of reproduction is independent of the functions of the life of the colony, and the individual exists apart from its offspring. From all of this it appears that conjugation is the first step in the direction of sex union, and that conjugation must therefore be regarded as a form of sex union, although the sexes have not been sharply differentiated in any true case of conjugation. DISTRIBUTION OF ASEXUAL REPRODUCTION Among plants asexual reproduction is nearly universal, all of the lower plants, and nearly all the higher ones, being able to multiply by some form of budding or division. Parthenogenesis is also fairly frequent. Among animals multiplication by budding or division is also widely distributed. It is universal among the unicellular animals, and is a common method of multiplication among such lower forms as Hydra and its allies. As we pass to higher animals this power disappears. It is found among some worms, and one group of animals related to the vertebrates (Tunicata) forms colonies by budding, which may break up and become several colonies, this constituting a modified kind of reproduction. In no other higher animals does asexual reproduction occur. The modified type of asexual reproduction which is called parthenogenesis is found among some of the higher animals, being fairly common even among insects. Sexual reproduction, using this term to include conjugation, is very widely distributed among organisms and, indeed, is possibly coextensive with life. It is true that there are many forms of unicellular animals and plants in which it has never been shown to occur; but in many cases this is due to incomplete knowledge. With increasing knowledge, more and more of the unicellular organisms are known to go through the process of cell union under some conditions. Even some of the longest known and best studied organisms (Amoeba) have been recently shown to undergo conjugation. In the malarial organism, for example, there is at one stage in the life history a union of two unlike cells, which are regarded as male and female, and a similar differentiation of uniting bodies has been found in many other single-celled organisms. The continued discovery of new examples of sexual union or conjugation, among the lower organisms previously supposed not to have this power, has led to a belief that a union of cells in reproduction may be a universal characteristic of all life, even though there are still many of the lower animals and plants in which it has not been found. This conclusion is as yet by no means proved and may not turn out to be strictly true. In all groups of animals above the unicellular types, sexual reproduction, by the union of true male and female cells, is universal, and in the higher groups it is the only method of multiplication known to occur. REPRODUCTIVE BODIES OR REPRODUCTIVE CELLS This term refers to the parts which are separated from the bodies of animals or plants, and capable of growing into new individuals. Sometimes they are multicellular fragments, like the buds of Hydra or the gemmce of a plant; but in such cases the term reproductive body is not usually applied to them. In the large majority of cases the bodies formed for reproductive purposes are single cells which are capable of developing into new individuals, and hence the term reproductive cells better describes them. Of these reproductive cells we recognize the following kinds : — a sperm. The name gametes (Gr. gamete = wife or husband) is frequently applied to the cells that unite with each other in cell union. This term, therefore, includes eggs and sperms, and also the uniting cells in conjugation where no distinction of sex is seen. CROSS FERTILIZATION THE RULE Cross Fertilization. — In ordinary sexual reproduction the rule is that a single sperm unites with a single egg. When the sexes are separate, as in the frog, this will always result in the fertilization of an egg from one individual with a sperm from another. As we have seen, some animals produce both eggs and sperms, and might fertilize their own eggs. But usually there is some device to prevent this. In the earthworm, although both eggs and sperms are produced by each individual, in copulation there is an interchange of sperm fluid, in such a way that the eggs of each individual are subsequently fertilized by the sperms from the other. This is called cross fertilization. In most cases where both male and female organs are produced in the same individual, there is some device by which cross fertilization is insured. In the common flowers both male and female organs are developed in each flower, but there is almost always some means which prevents the flower from self-fertilization and insures cross fertilization. In a few animals and plants, it is true, self-fertilization appears to be the rule, but it is very unusual. It appears that the reason why cross fertilization is so commonly found, is that it results in more or stronger offspring. Experiments carefully carried out in plants have shown that, in many cases at least, the offspring resulting from cross fertilization are more vigorous than those coming from close fertilization. In animals there is less evidence at hand on the subject, but here, too, it has been recently shown that, in some cases at all events, cross fertilization is more productive of a vigorous progeny. Apparently, then, cross fertilization is based upon a fundamental law. Hybrids. — On the other hand, it is necessary that the sperm that unites with the egg shall come from another individual not too unlike the one that produces the egg. If the egg belongs to one species of animal or plant and the sperm to another species, they are not likely to unite at all. If two different species are crossed the rule is that there is no offspring, or that, if there is offspring, they will themselves be incapable of producing young. Such an individual is known as a hybrid, and frequently hybrids are sterile. But most careful study of both animals and plants has shown many instances where hybrids are fertile, so that the sterility of hybrids is by no means a fixed rule. In general, however, in order to produce the most vigorous offspring it is necessary that the eggs of one individual should be fertilized by sperms from another individual of the same species, but not too closely related. Close inbreeding has a tendency to foster weakness. In many plants, and in some animals, there is a regular alternation in the methods of reproduction, i. e., that with sex union and that without sex union. This is commonly spoken of as the al- scope shows that they are made up of a number of little sacs, containing minute reproductive bodies; Fig. D. When mature the sacs burst and the reproductive cells are thrown out into the air. If they fall upon some surface where they have the proper temperature and moisture, they begin to grow at once; and since A, the fern attached to its root-stock; B, the back of two leaflets, showing the sori ; C, a leaflet more highly magnified showing the sporangia within the sori; D, one of the sporangia still more highly magnified discharging spores. they are thus capable of growing immediately into new plant! without being united with sperms, we know that they must be spores and not eggs, since eggs require fertilization before they will develop. The sacs that contain them are sporangia, spg. This method of reproduction is therefore evidently an asexual method. A and B, sprouting spore; C, prothallium full grown; D, section of an archegonium; E, archegonium at a later stage, showing the ovum, o, and the sperm, spm, entering to fertilize the ovum; F, section of an antheridium at an early stage; G, an antheridium at a later stage, discharging sperms; H, the young fern, /, growing from its prothallium. small, flat, green leaf (Fig. 125 A to C), which clings closely to the ground, as shown at H , usually not growing to more than one-quarter inch in diameter, and frequently even less. It has no stem, but on the under surface are a few delicate hairs called rhizoids, which grow downward, fastening the plant to the soil and giving it nourishment. It is called a prothallium (Lat. pro = before + ihallus = branch) and one would never suspect that this little plant had anything to do with the fern which produced it. We rarely see the prothallia of the fern, not because they are not abundant, but because they are so small and grow so closely to the ground that they do not attract attention. They may be found without much difficulty, however, by carefully searching for them. One of the easiest places to find them is on the outside of the moist earthen flower pots in a greenhouse where ferns are abundant. After the prothallium has reached its full growth an examination of its under surface with a microscope shows that it in turn is getting ready to carry on a process of reproduction. On the under surface may be found several little projections (Fig. C), too small to be visible to the naked eye but clearly made out with the microscope. They are of two kinds, one lying among the rhizoids near one edge of the leaf, an, and the other lying near the other edge, some' distance from the rhizoids, ar. The latter are slightly elongated, with an opening at the free end, and a little canal extending down the middle: they are called archegonia (Gr. arche- = beginning + gonos = birth) ; Figs. D and E. At the base of each archegonium is a single egg, o. The other protuberances, lying near the edge of the leaf among the rhizoids, are called antheridia (Gr. antheros = flowery) ; Figs. F and G. They are more rounded in shape, not so long as the archegonia, and their contents are quite different. Instead of containing a single egg, the whole contents of an antheridium divides up into a large number of parts. Eventually an opening makes its appearance at the end of the antheridium, and these minute bodies emerge and prove to be sperms, spm (sometimes called spermatozoids). The fern prothallium grows only on moist surfaces and clings so closely to the ground that in times of rains or heavy dew its under surface is likely to be covered with water. Each sperm bears a tuft of swimming flagella, which lash to and fro and enable them to swim in the water, which moistens the under surface of the prothallium. In thie moisture they swirn in all directions, and some of them come to the mouths of the archegonia. When this occurs there is an attraction between the egg at the bottom of each archegonium and the sperm which has reached its top; the sperm swims to the egg and fuse:with it, i. e., fertilizes it. After the egg has been fertilized by the sperm, it is endowed, like any other fertilized egg, with the power of growth. It soon begins to divide, grows rapidly, and develops in the course of time into a little plant which, by continued growth, becomes the fern with which we are familiar and like that with which we started the history; Fig. H, f. Thus we see that the common fern grows from a fertilized egg, and that the spore produced by the fern grows, not into a fern at first, but rather into a prothallium. The life history of the fern is thus an alternation of two different stages and two different methods of reproduction. There is first the fern proper, which, since it produces only spores, is the asexual stage of the plant, and is called the sporophyte (Gr. sporos + phyton = plant). The second stage is the prothallium, which, since it produces eggs and sperms, is the sexual stage. This is called the gametophyte (Gr. gamete -fphyton) stage, since it produces gametes. Each of the thousands of spores of the fern is capable of producing a single prothallium. The single egg at the bottom of each archegonium is capable of developing a single fern, and since there are several archegonia on each prothallium, a prothallium is thus theoretically able to produce several ferns. Usually, however, only one of the eggs becomes fertilized by a sperm, therefore only a single fern develops from a prothallium. Sometimes two eggs may grow, and occasionally three may develop, so that two or three little ferns may sometimes be found growing from a single prothallium. common flowering plant there is an alternation of generations, based upon the same principle as that just described in the fern; but it is so obscured by certain modifications that it is extremely difficult to understand. The difficulty lies in three facts: (1) Two kinds of spores are produced instead of one, as in the fern; one of them becomes the female gametophyte, ; producing the equivalent of the archegonium of the prothallium Vth its egg, while the other becomes a male gametophyte, producing the equivalent of the antheridium of the prothallium with its sperms. (2) Both of these gametophytes have become very much reduced in size and are only distinguishable by microscopic examination with special methods. (3) These two gametophytes grow attached to the plant that produces the spores instead of detached from it, as does the gametophyte of the fern. If these differences be kept in mind the alternation of generations in the flowering plant is plain. It is as follows: — We usually speak of the flower as containing sexual organs, the stamens being spoken of as the male and the pistil as the female organs. When the pollen is carried to the pistil it has commonly been spoken of as fertilizing the stigma, the inference being that the pollen is the male cell and actually fertilizes the female cell in the pistil. When the flower is studied by modern methods, however, it is found that in reality it is not a sexual plant at all, and does not produce sexual organs. The stamens are not male organs and the pollen is not a male cell; the pistil itself produces no eggs. The pollen is really a mass of spores, called microspores. In the pistil, as already noticed (see Fig. 64), are several ovules and inside of each ovule is a single large cell, formerly called the embryo sac, but now known as a macrospore ; Fig. 126 sp. The flower thus produces large numbers of microspores and a smaller number of macrospores, which together correspond to the spores of the fern. These cells are known to be spores rather than gametes, since they do not unite with each other. That ihe pollen is a spore rather than a sex cell is proved by united with another cell. The macrospore is also proved to be a spore by the same fact, since it also grows into a new plant without being fertilized. Since the flower-bearing plant thus produces spores instead of eggs and sperms, it is clearly a sporophyte rather than a gametophyte, and it corresponds to the fern frond rather than the fern prothallium. It FIG. 126. — MAGNIFIED differs from the fern, however, in that SECTION OF THE YOUNG it produces two kinds of spores instead OVULE, o, OF A FLOWER- of one. This condition is spoken of as ING PLANT heterosporous (Gr. heteros ••= other + If we now try to follow out a comparison between the flower and the fern, we should expect that the flower spores would germinate at once into gametophytes, just as the fern spores germinate into the prothallium, and that the gametophytes would produce the real sex organs with sperms and eggs. Since, however, there are two kinds of spores, we might expect two kinds of gametophytes to grow from them instead of one kind, as in the fern. This actually occurs, only the two gametophytee are very small and rudimentary. The macrospore never gets out of the pistil but, in the midst of the pistil tissue, develops quickly into a tiny growth that represents a gametophyte stage, and this soon produces what corresponds to an archegonium with its egg; Fig, 127. All this occurs early in the life of the flower, before any pollen has been brought to the pistil, and consequently before fertilization can have occurred. It is simply the germination of a spore to form a gametophyte. The pollen, too, goes through its history, growing very slightly but sufficiently, to show that it develops into a gametophyte in its turn. This occurs either before it has left the anther pollen tube which grows down through the style of the pistil (Figs. 65 and 127 pi), in a way corresponds to the antheridium ; and inside it are small cells, or nuclei of cells, m, that corre of the pistil one kind of spore grows into a female gametophyte and produces eggs, while on the stigma the other kind of spore grows into a rudimentary male gametophyte and produces the equivalents of sperms. Following farther the comparison with a fern, the next step is the fertilization of the egg of the female gametophyte by the sperm of the male gametophyte. In the flower this fusion is accomplished as follows: The pollen tube "(Fig. 1281?) is an outgrowth from the male gametophyte, and pushes its way TOPHYTE G, the gametophyte; e, egg; pt, a pollen tube pushing its way through the style to fertilize the egg; m, is the male nucleus in the pollen which corresponds to the sperm and fertilizes the egg. down the style until it reaches the ovule at the bottom of the ovary; see Figs. 65 and 127 pt. In this ovule the female gametophyte has formed, and has by this time produced what corresponds to archegonia with their eggs; Fig. 127 e. The tip of the pollen tube approaches the egg and finally comes in contact with it. Inside o* the pollen tube are nuclei which represent the sperms; Fig. 127 m. As we have noticed on page 257, when the fertilization of an egg occurs it is only the nuclei of the cells that fuse, so that the nuclei in the pollen A, a single pollen grain or microspore; B, the cell divided into two; C, the pollen, which has produced a rudimentary gametophyte at g; D, a later stage with the gametophyte g still more rudimentary; E, the pollen developing the pollen tube. The nucleus m divides later into two nuclei representing sperms. tube represent all of the important parts of a sperm. When the pollen tube comes in contact with the egg it allows these nuclei to escape into the egg, where one of them fuses with the nucleus of the egg, thus producing the actual sex union. The fertilized egg is now endowed with powers of growth and begins at once to develop into a new plant. Again following the comparison with the fern, we shall expect that the plant which comes from the fertilized egg must be the sporophyte, which in this case is, of course, the plant that produces the flowers. The egg develops at once, growing quickly into a tiny plant with a stem and one or two leaves. This occurs while the egg is still retained in the ovary of the flower that produced the spores. After a time this plant stops growing and becomes surrounded by a hard shell, inside of which it remains dormant for an indefinite period. This forms the seed, which thus appears to be a little sporophyte surrounded by a shell, and it remains dormant until later when it can be placed under proper conditions for germination; Fig. 66. It develops its spores, of course, after it has grown large enough to produce flowers. It is thus seen that the flowering plant has an alternation of generations as truly as does the fern, only in the flowering plant the sex stage, the gametophyte, is very small, while the asexual stage is very large. The plant with which we are familiar is in the sporophyte stage, and the pollen and the single cell inside its ovule are its spores. These develop into tiny growths that correspond to the gametophytes and are developed within, or attached to, the sporophyte that produced the spores, i. e., in the ovary or attached to the stigma. But tiny as they are, they produce the equivalents of eggs and sperms, which subsequently fuse by true fertilization. The real fertilization of the plant, then, is the fusion of the male cell contained in the pollen tube with the egg contained in the ovule. The term fertilization, which has been commonly applied to the transfer of the pollen to the stigma, is a misnomer, and is largely given up, the term pollination being substituted instead. Alternation of Generations among Animals. — An alternation of generations also occurs in the animals known as hydroids, animals related to the Hydra. The fresh-water Hydra, as described in Chapter VII, multiplies by budding; but as fast as the buds are produced they break away from the original animal and become independent. In the marine Podocoryne, the buds do not break away but remain attached to form a colony, made up of large numbers of individuals; Fig. 129. The individuals are partially independent of each other and. if broken apart are capable of living independent lives. This stage of the life of the animal, since it has an asexual multi- plication by budding, is the asexual stage, and is comparable to the asexual stage of the fern above described (the fern proper). It differs from the fern, however, in the fact' that ?t does not produce new individuals by spores, but by budding. After a colony reaches a certain stage in its growth, some buds arise which differ in shape from the others. These (Fig. 129 gb) are rounded, and eventually break away from the Colony and assume an independent existence. These free buds now become bell-shaped individuals of clear, transparent jelly, and are known as jellyfishes or medusae, m. The jellyfishes have muscles which enable them to swim and travel for long distances in the ocean. As they have a mouth and digestive cavity they can procure their own food, and grow, frequently attaining considerable size after separating from the original colonies; some species, indeed, assume a size very much larger than the animal that produced them. The alternation. Among animals, however, alternation of generations is found only in the lower orders. It is common among the Hydroids, and a modified form of it occurs in one of the higher animals (Salpa) ; but among the great majority of animals, when sexual reproduction is developed, the non-sexual method is totally lost. EMBRYOLOGY AND METAMORPHOSIS BY the term embryology is meant that part of the life history of the animal or plant which begins with the fertilization of the egg and continues up to the time when a developed animal is formed, ready to emerge from the egg as a free-living, independent individual. When it hatches from the egg it is sometimes like the adult, except in size; but sometimes it is unlike its parents and goes through a further series of changes. In this case we speak of these later stages as constituting the larval history or a metamorphosis (Gr. meta = beyond + morphe = form). The development of animals from the egg to the adult stage, embryology and metamorphosis, has proved to be an especially interesting phase of biological study, and has received much attention in the last fifty years. The embryology of different animals and plants differs widely, but certain fundamental laws and rules are found to apply to all alike. In this introductory study it is only possible to give a few of the fundamental principles, using a single animal as an illustration. For this purpose will be described the development of the frog, which, although peculiar in some respects, will illustrate the important laws both of embryology and metamorphosis. The embryology of plants has also been studied rather extensively, but has not hitherto yielded so many interesting lessons as the embryology of animals. EMBRYOLOGY OF THE FROG 1. Segmentation. — The life of an individual frog may be said to begin the instant that the nucleus of the egg fuses with the head of the sperm (Fig. 121 H), the time of fertilization being thus a starting point of a new life. This fertilization of of this division there are produced two cells, FlG 131 each with a centrosome, each with its PRODUCTIVE nucleus, which contains the same number of CELLS OF chromosomes as the fertilized egg nucleus. FROG Moreover, at the beginning of the division, sp^r'megg; B' the each chromosome is split lengthwise, and half of each chromosome passes into each of the two nuclei of the two new cells. Each of the two cells thus contains chromatin material from each of the chromosomes of the fertilized egg, and since these chromosomes come partly from the male and partly from the female parent, it follows that one-half of the chromatin in each cell is derived from the male, and one-half from the female parent. Hence, each cell will contain inherited traits from each parent. This first division of the egg is soon followed by a second, which produces four cells, and in this division the same process is repeated, the chromatin material being again split up so that each of the four cells (Fig. 132 A) contains chromatin material from both parents. This process now goes on, the cells dividing again and again, until the original egg has divided into a large number of small cells, each cell probably containing chromatin material from both parents. This process of segmentation or cleavage is the first step by which all animals and plants begin their life history, the egg in all cases dividing after a similar manner into a large number of cells. A, eight stages of the segmentation of the egg; B, section of the egg showing the beginning of the differentiation of ectoderm from endoderm; C, sections at a later stage, showing the growth of the ectoderm over the endoderm; D, section after the germ layers are formed; «c, ectoderm; en, endoderm; mes, mesoderm; E, surface view of a young embryo showing two branchial slits, brc; F, surface view of an older embryo; G, diagrammatic, longitudinal sections of the stage F ; H, a later stage. In these diagrams the ectoderm is in black, mesoderm, with dotted shading, and endoderm without shading. DEVELOPMENT OF THE FERTILIZED EGG 283 2. Differentiation. — Although the cells at the outset are much alike, they soon begin to show differentiation. In Figure 132 B it will be seen that the upper cells are smaller than the lower ones, and the contents of the larger cells are quite different from those of the smaller. The difference thus shown early in the development of the egg marks the distinction between those cells which will eventually form the alimentary canal and those which will form the other parts of the body. As the development goes on and the number of cells in the embryo increases more and more, greater and greater differences are found among them (Figs. C and D), so that one group of cells after another becomes set apart by differences in structure and functions, until finally, when the animal has reached the adult form, it is not only composed of innumerable cells, but these cells have assumed a great variety of shape and function. This process of gradual change of shape and function of cells which were originally alike, is spoken of under the name of differentiation. A similar change occurs in all multicellular animals and plants; for, after segmentation of the egg, there always follows a differentiation of cells. 3. The Formation of Germ Layers. — After the cells have multiplied until they have become quite numerous, they begin to arrange themselves in three groups. Soon there appears an outer layer, an inner layer, and a -middle layer, known respectively as ectoderm, endoderm, and mesoderm. These are shown in Figure 132 D, which represents a later development in the frog. The method by which these three layers are formed is shown diagrammatically in Figure C. It may briefly be described as the growing of the mass of the smaller, ectoderm cells, around and over the larger, endoderm cells, so as finally to bring the larger cells upon the inside of the embryo, surrounded by the smaller ones. Meantime there has grown from the outer and inner layers a third mass of cells, the mesoderm, that pushes its way between the other two, thus partly filling up the space between the outer and inner layers; Fig. D. The final result is that the embryo has an ectoderm of smaller cells on the outer side, an endoderm of larger cells on the inner side, and a mesoderm between the outer and the inner layer. These three layers of cells remain distinct, and are destined for different purposes in the subsequent life of the animal, each one of them developing into certain organs only. The organs that are developed from the three layers are as follows : — The mesoderm. — From the mesoderm develop the muscles, the bones, the heart, and the blood vessels, the lining of the body cavity, the outer layer of the alimentary canal, the mesentery which holds the alimentary canal in position, and the reproductive system. The endoderm. — From the endoderm develop the alimentary canal, the glands around the mouth, the lungs, the pancreas, and the liver. The muscles which form the wall of the alimentary canal are developed from the mesoderm, but the lining of the digestive tract, with all its glands, which secrete the digestive juices, is formed from the endoderm. The ectoderm. — The ectoderm gives rise to the skin, including the epidermis and the dermis. It also grows inward to line the mouth and the extreme posterior end of the alimentary canal. The ectoderm also gives rise to the nervous system, with all of its parts, including the brain, the spinal cord, the nerves, and all of the sensory organs, like the eyes, the ears, organs of smell and touch. It will be seen that the alimentary canal is made of three parts: the anterior end is formed by the infolding (imagination) of the ectoderm, the infolded part forming the mouth or buccal cavity; the posterior end is also formed by an invagination of the ectoderm, which forms the cloacal chamber; the rest of the canal is formed from the endoderm. These three parts are called the foregut (stomodceum) , the midgut (mesenteron) , and the hindgut (proctodceum) . Similar relations are found in other vertebrates and also in the lower animals as well. of nearly all animals. Among some of the very lowest ( Hydra) only the ectoderm and the endoderm are formed, the mesoderm being omitted. But in all except the lowest types three layers are formed early in the embryological history. The method by which these three layers are formed differs in different animals. In Figure 15 is shown a method of formation of the endoderm, differing from that of the frog, by an infolding of a hollow sphere to form a double sac. But however differently the layers are formed, the system of organs which are developed from them is essentially the same. The nervous system is always developed from the ectoderm, the alimentary canal from the endoderm, and the blood system and muscles are developed from the mesoderm. 4. The Formation of the Body.— While the germ layers have been forming, the embryo has been elongating (Fig. 132 E\ and the endoderm forms itself into a hollow tube within the body, which acquires an opening, first at one extremity and then at the other; Fig. G. This tube becomes the alimentary canal, and the two openings are the mouth and the anal, or cloacal opening. Between this inner tube and the outer wall of the body lies a cavity, more or less filled with the mesoderm, but in it eventually appears the body cavity or ccelum, which becomes a more distinct cavity as the animal grows. Early in the development, when the animal has assumed the form shown at E, openings in the side of the neck break through from the alimentary canal to the exterior. There are at first two of these, shown at E, brc, but later others appear. These are known as branchial openings, and become passages through which water taken in at the mouth may be passed to the exterior. They represent the gill slits present in fishes, and are to have a similar function a little later, when the frog hatches from the egg and lives in the water. While these changes are going on there is formed a long, thickened rod of ectoderm in the middle line of the back, extending from one end of the animal to the other, which is the beginning of the nervous system; Fig. G, n. The result is the formation of a little animal such as is shown in Figure H, in which the relation to the adult structure can be clearly seen, although at this stage the embryo only slightly resembles the adult frog. The development that has taken place up to this point has occupied a period of several days from the time when the egg was fertilized, the exact length of time depending to a large extent upon the temperature, the different stages being more rapidly passed through if the eggs are kept warm than when they are kept cool. Various other systems of organs begin to appear at this stage or a little later. From the ectoderm along the middle line in the back, develops a rod of nervous matter, and around the front end of this, outgrowths appear, which become the eyes, ears, and other sense organs. The nervous mass itself differentiates into the brain and spinal cord; Fig. H. The endodermal tube also develops outgrowths which in time become the lungs, liver, and pancreas. One part of the mesoderm forms itself into a gelatinous rod running lengthwise in the back of the embryo, just beneath the nervous system. This is the notocord, nc; it represents the beginning of the spinal column, and in time the vertebrce grow around it. Another part of the mesoderm develops into the heart, ht, and blood vessels; while that part of it which lines the body wall becomes the muscles, and that which is next to the intestine develops into the pmtoneum<smd mesentery. From the mesoderm, too, the kidneys and sexual glands arise, with their ducts, s. These changes take place quite rapidly, although they are not completed for many days. When they are finished the whole series of the organs of the frog is present, though yet incompletely developed. Meantime the animal has hatched from the egg, and forces its way out of the jelly in which it has been embedded and assumes an independent life. 5. Metamorphosis. — The further development of the frog comprises a number of different stages, shown in Figure 133, the important features of which are as follows: The animal elongates, and a slight constriction appears behind the anterior end resembling a neck. The front portion is, however, not the head alone, but the head and body fused together, while the back portion soon grows out into an elongated tail. From the side of the two branchial openings feather-like external gills or branchiae develop, which, projecting laterally from the head, serve as respiratory organs; Fig. D. The free larva is now known as a tadpole, and from this time it is obliged to depend upon itself. Its digestive organs have become developed enough to perform their functions, and the larva begins to feed upon vegetable food, eating the delicate green plants that are found growing on the bottom of the pool where the larva attaches itself. The rapidity with which the animal goes through the subsequent changes is dependent chiefly upon the amount of food it obtains, and the temperature; but it soon begins to pass through the stages represented in Figures C to G. The front end of the body, which is the head and body fused together, increases in size and becomes rounded, while the tail elongates and becomes flatter, serving as a swimming fin. The external gills disappear; but the gill slits remain, the animal still breathing by the use of internal gills, not visible from the outside. The size of the tadpole varies with the different species of the frog; in some of the ordinary frogs it may become two or even three inches in length, while in other species it is not more than half an inch. The next change is the appearance of a pair of small protuberances, or buds, on the posterior end of the body on either side; Fig. 133 F. These grow rapidly in length and develop into the hind legs. A similar pair of buds appears at the anterior end of the body, a little behind the gill slits, which later grow into the fore legs or arms. As these legs and arms grow, the whole shape of the body changes; the eyes appear on the sides of the head; the mouth, which is at first a round sucking slit, elongates into a large slit surrounded by the jaws; the head assumes more of its final form; the shape of the body changes from the rounded tadpole to a more elongated structure. The tail also shortens until it disappears. It does not drop off, but is gradually absorbed into the blood vessels and carried to the rest of the body, where it is used as nourishment for the other parts of the body. These changes are not abrupt but take place gradually as the animal assumes the adult form; Fig. 133, F to K. By the time the form shown in Figure J is reached, the gill slits have entirely closed, the skin growing over them; and from this time on the animal takes air into its mouth and forces it into its lungs in the ordinary fashion of the adult frog. It changes, therefore, from a water-breathing to an air-breathing animal. But even when it is an adult, the animal never quite loses its power of respiring by means of water, for the skin of the adult frog is always kept moist, and contains abundant blood vessels by means of which oxygen can be absorbed from the water, and carbon dioxid excreted. Not until the gill slits have closed and the lungs have become functional is the frog able to leave the water and live in the air. By this time its legs have become well grown and are strong enough to enable it to move more or less vigorously on the land, so that the tadpole may leave the water and assume its adult habits. Other Types of Metamorphosis. — Such a series of changes from the embryo to the adult is known as metamorphosis. Many other animals besides the frog have a metamorphosis. One of the best-known examples is the metamorphosis of a butterfly, which hatches as a caterpillar, lives a considerable part of its life in this stage, and then passes into a pupa iriside of a cocoon. Here it remains dormant for a considerable time and eventually emerges in the form of a winged butterfly, the imago. Many other types of metamorphosis are found among animals, for it is quite common for them to pass through a series of stages in their development, each stage being different from the other, and each different from the adult. Not all animals, however, have a metamorphosis, many passing by a very direct course to the adult stage. In the ordinary chick, for example, the embryo pursues the most direct course possible for building itself from the simple egg to the adult, and the chick, when it hatches from the egg, is practically adult in form, although not in size. In such cases we call the history a direct development, in contrast to an indirect development or a metamorphosis. Embryology a Repetition of Past History. — It will be seen from the development of the frog that at one period it resembles a fish in a number of points. It lives in the water, has a flat swimming tail, possesses branchial slits, and carries on respiration by means of gills. The study of geology has shown that in the history of the world fishes preceded frogs, and it is thus seen that in its embryology a frog shows a tendency to repeat the past history of animals. Such a repetition is found, not only in the frog but in many other animals, for it is a fundamental biological law that embryology repeats past history. In technical terms this is expressed by the statement that ontogeny is a repetition of phylogeny, ontogeny (Gr. on = being + -geneid) being the individual's embryological history, and phylogeny (Gr. phylon = tribe + -geneia = producing) the history of the race, during the geological ages. This parallel has been one of the strong arguments which have convinced scientists that our present forms have been derived by ordinary methods of descent, through the process of reproduction, from the earlier inhabitants of the world; or, in other words, that the history of the organic world has been one of evolution and not one of special- creation of each species independently, as was formerly believed. While a few years ago this law of repetition was thought to be more strictly adhered to than careful study has proved to be the case, the general fact that embryology tends to repeat past history remains as one of the interesting and significant laws of nature. It is sometimes called the biogenetic law. Oviparous and Viviparous Animals. — Many animals (for example, the frog) extrude their eggs into the water as soon as they are mature and take no further care of them. In some cases, as in birds, snakes, etc., the eggs, after being laid, are still cared for by the parents, and may be incubated by the parents to keep them warm during their development. All animals that thus lay eggs are called oviparous (Lat. ovum = egg -f- parere = to bear). A few of the higher animals, like the mammals, retain the egg for some time within the body of the mother. The sperms from the male in these animals are carried into the oviduct at copulation by the penis, and the eggs are fertilized while they are still within the oviduct. After the egg is fertilized it attaches itself to the part of the oviduct called the uterus, and here undergoes development. The developing embryo, called the foetus, is nourished through the maternal blood vessels, and grows to a considerable size while still retained in the uterus and attached to it by a membrane called the placenta. Eventually, when it has become mature, it is detached from the uterus and expelled to the exterior at birth. The young are well developed at birth, and such animals are spoken of as viviparous (Lat. vivus = alive + parere = to bear). MATTER By matter is meant the substance of the objects found in nature, such as earth, stones, etc. One of the fundamental laws of physics is that, while matter may be changed from one form to another, it can neither be created nor destroyed. The amount of matter in the universe at the present time is thus exactly the same as it has been in all previous ages. by illustrations. Active Energy. — A cannon ball flying through the air is said to possess energy. It is flying with such force and momentum that it requires great resistance to stop it; and if the ball could be received upon properly devised machinery, its motion might be made to turn wheels or do any other kind of work. The revolving flywheel of an engine also possesses energy of the same type, its motion and its great momentum enabling it, if connected with machines, to move them and make them do work. In the same way, any form of motion is energy. In another type of energy the motion is not so evident. Heat, liberated from burning coal, is energy, since, when it is properlyapplied to an engine, it may be made to do work. In this case the heat may be applied to water, which it vaporizes into steam, and this eventually may produce motion in an engine; but it is fundamentally the power in the heat that goes into the engine and finally exhibits itself in the motion. In the same way, the electric current, flashing along the electric wire, is energy, since this also, if received by a proper machine, can be made to set machinery in motion and thus accomplish work. Each of these four examples of force clearly comes under the definition given, since they all show the power of doing work. They also have another common characteristic: they all represent motion. The cannon ball and the flywheel are evidently in motion, and the physicist has shown that heat and electricity .are also forms of motion. Each of these four examples, then, represents energy in action. An indefinite number of other examples of this same type could be given, for all forms of light, hoat, motion, chemical action, and electricity are examples of energy, and, in one form or another, all represent energy in motion. This general type of energy in motion is active energy or kinetic energy (Gr. kinetos = moving). Passive or Potential Energy. — Energy is not always active but,, under some circumstances, it assumes a dormant form, which we sped: of as potential energy. By the term "potential" is meant that the energy, though not at the moment active, may at any time be converted into active energy. Fcr example, a heavy stone, poised on the roof of a house, is at rest, exhibiting no active energy; but it has potential energy, in virtue of the fact that it is raised some distance above the ground. The moment it is dislodged it begins to move, falling to the ground by the law of gravitation, and as it falls it develops the energy of motion. No energy is put into the stone by simply dislodging it from its position on the roof; hence it follows that the stone contained the energy when it rested upon the roof, only the energy was in a dormant or potential form. When it was dislodged from its position the potential energy began to be active, and when the stone reached the earth it became quiet again, its energy having apparently disappeared. A different type of potential energy is illustrated by a bit of ordinary coal. The coal that is put into a furnace contains, stored within itself, a large amount of energy in a dormant form. That it contains the energy is perfectly evident from the fact that we need only put it under proper conditions, by kindling it, and the energy will be liberated from the coal in the form of heat, which may be converted into ^notion by an engine. We can get no motion out of the steam engine unless we put the energy into the furnace in the form of coal, wood, or other fuel. Evidently fuels may be looked upon as containing a store of dormant energy. These types of passive energy, which exhibit no action, but which are capable of being brought into activity when placed in the right conditions, are spoken of as potential energy or energy of position. THE CONSERVATION OF ENERGY Energy can neither be created nor destroyed. Just as we cannot destroy nor create matter, so we cannot destroy nor create energy, the amount of energy present in our universe to-day being the same as it has been in all previous time. This statement does not seem quite so self-evident as the statement that matter cannot be created or destroyed, for many examples occur that, at first sight, seem to be instances of the destruction of energy. A stone which has been dislodged from its position upon the roof falls rapidly to the ground and develops energy in falling, but on reaching the ground it stops suddenly and its energy seems to have disappeared. When a cannon ball strikes a ledge of rock it suddenly stops. Any examples of the stopping of motion would seem to be illustrations of the destruction of energy. A careful examination, however, shows that in these cases there is in reality, no destruction of energy, but simply the conversion of one form of energy into another. In the case of the stone lodged on the roof, it is evident that at one time a certain amount of energy must have been used to lift this stone into its position, and when the stone fell it only redeveloped .the energy that was originally required to lift it to its position. The amount of energy required to lift the stone to its position is exactly the same as that which is developed by the stone when it falls to the ground, and the lifting of the stone and its falling illustrates the conversion of active into potential energy and reconversion of potential energy into an equivalent amount of active energy. It would seem, however, that when the stone reaches the ground the energy disappears. But if we examine the fallen stone carefully, and the earth underneath it, we find that both have been warmed. The moment that the motion of the stone ceased, heat appeared. Heat is a form of energy, and thus, when the stone comes to rest on the ground, the motion of the stone is converted into that form of energy which is called heat. This heat is soon dissipated from the stone and from the earth, for they presently resume their former temperature. The heat has simply gone off into the air; it is not destroyed but has simply distributed itself, and slightly raised the temperature of the air. Nowhere in this series of changes has there been any loss of energy, but simply the conversion of one form into another. Some 5000 years ago the Egyptians lifted a large number of stones and placed them one on top of another so as to make the pyramids, exerting a large amount of energy; the energy used in placing the stones in position was stored away in the pyramids in the form of potential energy and is there still. If at any time the pyramids should topple over and the stones fall to the ground, there would be redeveloped an amount of motion exactly equal to the amount used to lift them in position. Thus energy may be stored away and remain in a potential form for ages; but at any future time the energy originally stored away may reappear in the form of active energy. The energy present in a dormant form in coal requires a little more explanation. Chemists have shown that the smallest particles of matter which we can see are themselves made of much smaller particles called atoms, which are quite invisible even with the highest-power microscope. They also tell us that these atoms are united in groups, which are called molecules, each consisting of a number of atoms. Just as it requires the expenditure of energy to lift stones into position to form a monument, it also requires energy to lift atoms into position to form a molecule; and if the molecule is broken down, the energy is liberated according to the same principle concerned in liberating it when a monument falls. If, therefore, we look upon the particle of coal as a series of molecules, each built up of many atoms, it follows that if these tiny molecules are broken down, so that their atoms will assume a simpler form, the energy imprisoned in them, in a dormant state, will be released. Coal is thus made of immense numbers of complex molecules, each of which has been built by the expenditure of energy, and the coal contains, in a potential form, energy which may be released by breaking up the coal. The molecule is broken down when the coal is burned and its energy appears in the form of heat, which may then be applied to the moving of an engine. This of course raises the question as to how the energy was stored away in the coal, — a question to which we will refer later. Any type of energy may be converted into any other type. When we lift a stone to the roof of the house we convert energy of motion into energy of position, and when the stone falls, energy of position is converted again into energy of motion. When it is halfway to the ground, it has a certain amount of energy of motion, because it is moving; but it also has a certain amount of energy of position, because it is considerably above the surface of the earth. The more closely it approaches the earth, however, the more its energy of position is converted into energy of motion, and the moment it strikes the ground, all of its energy of motion is converted into heat. The potential energy in the coal in the furnace is converted into heat ; the heat is converted by the engine into motion; the motion of the flywheel, by being attached to a dynamo, may be converted into electricity; the electricity, passing over the wires, may run into an electric lamp, where it is converted into light, or it may go into an electric stove to be converted into heat. The motion of water over a waterfall may easily be converted into the motion of a wheel by the means of a water-wheel, this into electricity, and this in turn into light, heat, motion, or any other form of energy that we wish to obtain. Some of the types of transformation of energy are more easy to bring about than others. It is much easier to convert motion into heat than to convert heat into motion. Any form of motion is sure to take the form of heat eventually, whether we are turning a grindstone or putting a brake on a railroad train, or whether a cannon ball is stopped by a stone cliff. Heat, indeed, seems to be the type which all forms of energy have a tendency to assume in the end; it is then radiated into the atmosphere and into space, where it is beyond the reach of this earth and is called radiant heat. It is true that we have some devices by which heat may be reconverted into motion, but always with considerable loss as radiant heat. We put into our steam engines five times as much stored energy in the form of coal as we receive in return in the form of motion, not because the energy is destroyed, but because four-fifths of the energy of the coal is wasted in heating the machinery and the air, and then passes away as radiant heat, only a small part being converted into motion. Definition of a Machine. — A machine is any device which converts one form of energy into another. The locomotive is a machine for converting heat into motion; the electric bulb is a machine for converting electricity into light; the motor converts electricity into motion. Even the gas burner is a machine for converting the chemical energy of the gas into light. A clock is a machine which converts the potential energy in its coiled spring into the motion of its pendulum and hands; a sailboat is a machine for converting the energy of the wind into the motion of the boat. So one might illustrate indefinitely. In no case is there any creation of energy by the machine, simply the conversion of one form into another. Not only is there no creation of energy, but there is an actual loss of available energy, inasmuch as heat always develops, and after energy has assumed the form of heat, as we have just seen, it is difficult to get it back into another form. While there is no actual destruction of energy when it is converted into heat, there is, in every form of machinery with which we are acquainted, a loss of available energy. Sometimes this loss is very great. For example, in an ordinary electric lamp about 95% of the electrical energy that is put into the bulb is lost; only 5% of it appears as light. The efficiency of a machine is indicated by the percentage of the energy supplied which we can get back in the form that we desire. Machines differ much in their efficiency in this respect. It is quite easy to get very efficient machines for converting motion into heat, but very difficult to get an efficient machine for converting heat into motion. The most efficient machines that we have for this latter purpose are gas engines, some of which give back 25% or 30% of the energy put into them. Most engines give a far smaller proportion than this. Many steam engines give back as motion not more than 5% to 10% of the energy furnished. This matter of efficiency is one of interest as we come to study the power of living organisms to convert one type of energy into another. THE LIVING ORGANISM AS A MACHINE From the definition above given it is very easy to see that the living organism, either animal or plant, is a machine, since it is a mechanism which transforms one type of energy into another. This may best be understood by considering first the life of plants and then that of animals. THE LIFE OF A PLANT Sunlight furnishes the earth with practically all its energy. There have been many attempts to make efficient sun engines, which will utilize the rays of the sun to serve directly as a source of energy sufficient to run engines. Sun engines have been made, but as yet they are cumbersome, unwieldy, and impractical. But it seems that the time must come, after the exhaustion of the coal supply, when sun engines will be a necessity. A plant growing on the surface of the earth is a perfectly efficient sun engine, devised by nature to utilize the rays of the sun and then to transfer the energy thus received to the rest of the living world. The life of the ordinary green plants consists of two features: (1) the utilization of the sun's rays and the storing away of these rays in a form of potential energy; (2) the liberation of this energy and its subsequent use by the plant. These two processes will be considered in turn. Energy Stored by Plants. — All green plants have the power of absorbing the sun's rays and, by the means of energy thus obtained, of building up chemical compounds of great complexity which will contain the energy thus absorbed, stored away in a potential form. Their method of accomplishing this is in part as follows: In Chapter VI we have learned that plants have the power of manufacturing starch out of carbon dioxid and water. This process involves the manufacture of complex molecules (C6Hi0O5) out of simple ones (H2O and CO2), and hence requires the expenditure of energy. Since it can take place only in sunlight, it becomes evident that (1) the sun's rays are the source of energy used, that (2) the starch manufactured will contain in a potential form the energy used in building it, and that (3) this energy may be liberated in an active form if the starch molecule is broken down. Stored Energy Utilized by Plants. — The energy stored in the starch is the primary source of energy for nearly all the activities on the earth, except water power. The plant uses it for two distinct purposes: L While plants do not in their ordinary life exhibit a great amount of active energy, they do develop a little heat and a little motion, and they are constantly lifting quantities of water from the soil to the tops of the branches. All this requires energy, which is obtained by breaking down some of the starch and utilizing the energy thus liberated. 2. Plants are always at work building other materials besides starch. Proteids, woods, and fats are manufactured by combining, within the living cells, the various materials absorbed by the roots (nitrates, etc.), with the starches made in the leaves. The chemical processes by which these new organic compounds are built are not yet understood, but one feature is significant. Just as starches are more complex than the water and carbon dioxid out of which they are made, so the proteids are far more complex than the starches, nitrates, etc., out of which they are made. Since it requires energy to build the complex molecule starch out of the simpler carbon dioxid and water, so too it requires energy to build proteids out of the starches and nitrates. For this purpose the plants do not use the sun's rays directly, but they use the energy they have stored in the starch. In other words, in making proteids, a certain quantity of starch or sugar is broken down into a condition of carbon dioxid and water, and as a result of this destruction the stored energy in the sugar molecule is liberated. This energy is liberated within the living cells, and under such conditions the protoplasm can make use of it for building the complex proteids out of the simpler materials. This general process is called metastasis. Thus it is seen that the plant protoplasm uses the starches for a double purpose. Part of them are reduced to the condition of carbon dioxid and water in order to liberate the energy needed by the plant. Part of them are combined with other ingredients to enter into the combination of proteids, etc. By this latter process there is thus (1) an accumulation of proteids and other substances in the plant body, (2) a destruction of sugar or starchr (3) an elimination of carbon dioxid and water, arising from the destruction of that portion of the starch which was utilized as a source of energy for the constructive processes. The carbon dioxid and water are waste products and are liberated at once by the process of excretion. Thus it will be seen that there are two processes going on in a plant body. One — photosynthesis — is a constructive process by which the sun's energy is stored; the other — metastasis — is a destructive process by which the energy is liberated. The former process is going on in green leaves and only in sunlight; the latter takes place in all of the living parts of the plant, whether in sunlight or in darkness, at all times when the plant is carrying on its life processes. By the former process starch is being made; by the latter the plant manufactures a host of materials which are stored away in its body in the form of proteids, wood, fat, cellulose, or other substances. Plants Produce an Excess of Organic Material. — In all gre^n plants, photosynthesis is much in excess of the metastasis, and green plants are constantly manufacturing a quantity of starch and other organic products, far more than they need for their own use. The materials thus produced serve not only as a reserve for their own future use but also for most other forms of activity on the earth. All fuel which is used by our numerous engines, whether wood, coal, oil, or gas, can be traced back to plant life, and represents, therefore, the sun's energy stored by photosynthesis. The food of all animals also comes from plants. Stored Energy Utilized by Animals. — The only source of energy available for animals and colorless plants is that stored up by green plants, and rendered available when liberated by the destruction of the compounds that hold it. The general result of animal life is a destructive one, with its resulting liberation of potential energy. Animal protoplasm is, however, able to carry on some constructive work. It can make fats out of starches, can convert one proteid into another, and can make new living protoplasm if fed with lifeless proteids; all of these are constructive processes. Whatever energy is needed for this work must be obtained by breaking down part of the food, so that the result is a reduction of the total amount of organic materials. In their constructive work, animals are not only unable to make starches and sugars, but they are unable to make proteids. Since they require these as materials out of which to manufacture muscles, nerves, glands, etc., it follows that they are dependent upon plants, not only for starches but also for proteids, which the plants manufacture and which the animals utilize. From this outline of the transformation of energy it is evident that living organisms, both animals and plants, are in a strict sense machines. That living beings possess special powers shown by no other kind of mechanism, and therefore belong in a category by themselves, is very evident; but so far as concerns the problem of energy they are machines. Vital energy is only the energy of sunlight transformed into various types within the mechanism of the living machine. Since coal is simply an accumulation of the remains of plant life of past ages, we now see the source of its energy. It contains the stored sunlight of the past. this comparison out in detail. Are the Income and Outgo Equivalent? — Can all of the energy shown by the living organism be accounted for by the energy furnished by the food, and, conversely, can all of the energy furnished in the food be accounted for in the form of energy exhibited in the living organism? If the law of the conservation of energy is correct, the answers to these questions must be in the affirmative. To get an experimental answer is not easy, but it has been done, as follows: A large box has been constructed in which is placed an animal, or sometimes a human being, and then the box is sealed. By means of ingenious apparatus the person inside of the box is furnished with the necessary air to carry on his respiration, and is given plenty of food and water; he remains in this box for a varying length of time. The apparatus is designed, not only to determine the exact amount of water and food that the individual consumes, but also the amount of oxygen he takes from the air, the carbon dioxid he breathes into the air, together with all the moisture that is eliminated from the body, and all other excretions. Moreover, the amount of energy furnished him in his food is measured, and the amount of heat liberated from his body is determined with accuracy, as well as the amount of work that he does. If the doctrine of conservation of energy holds concerning the animal body, as it does concerning other machines, it ought to be found by such an experiment that the amount of energy exhibited by the individual is identical with that furnished in his food, and that the amount of excretions is exactly equiv- alent to the amount of food consumed in his body during this given time. The difficulties of carrying on such an experiment have been great, but they have been surmounted satisfactorily, and the results are always the same. There is an exact equivalence between the income and the outgo of a living animal, both as to force and matter. The amount of excretion from the individual is exactly equal to the amount of food consumed; and the amount of energy developed is the exact equivalent of the energy contained in the. food that he uses during the same experiment. The general conclusion is that the income and the outgo of an animal balance, and that the living machine, like other machines, simply transforms one form of energy into another without creating or destroying it. In this statement no account is made of the energy of the action of the nervous system, which does not show itself in such experiments, the probable reason being that the recording apparatus is too coarse to show an amount of energy so slight as that exhibited by the nervous svstem. DETAILS OF THE ACTION OF THE MACHINE In the running of an ordinary machine, like a steam engine, we understand fairly well the details of its action. We can understand how the forces of chemical affinity break up the chemical compounds in coal; how the heat thus liberated vaporizes the water; how the water under pressure acts on the piston in the cylinder, and how this produces the revolution of the flywheel. It is true that we do not understand the forces of chemical affinity by which coal burns, but, apart from this, there is nothing mysterious in the fact that the engine converts the stored-up energy contained in the coal into the motion of the flywheel. Is a similar intelligible explanation possible of the activities that go on in the living organism? In other words, do chemical and physical forces suffice to explain the activity of the living machine, just as they do the activity of the non-living machine? MECHANICS OF THE LIVING MACHINE 305 To follow out this question 'in detail would take more space than could be devoted to it here. A few of the more important functions of life may be considered, and will serve to show how modern biological science endeavors to explain life phenomena in terms of chemical and physical forces. In this discussion we shall confine our attention wholly to the life of animals. The life of plants is far simpler than that of animals, and if it can be shown that the animal organism works in a mechanical fashion, we may safely assume that the same principle will hold for the vegetable kingdom. In following out this thought we will consider in succession several of the important functions of animal life. Digestion. — Digestion is simply a chemical change in the nature of the food, and involves nothing mysterious, nor any special forces. The foods when taken into the body are mostly insoluble. In order to pass through the walls of the intestine, they must first be dissolved in the liquids of ^the digestive tract, and before they are dissolved they must be changed into a soluble condition. The changes which make them soluble are not peculiar to the living body, since they will take place equally well in a chemist's laboratory. One of the most important steps in digestion is the change of starch into sugar; and starch, by proper chemical methods, can be changed into sugar just as readily in the test tube of a laboratory as in the digestive organs of an animal. The digestion of starch has nothing mysterious in it, and is only an instance of the application of the wellknown chemical forces. The same thing is true of all the other changes in the food which we call digestion. They are all chemical changes, resulting from the laws of chemical affinity. The only feature concerning the process that is not intelligible in terms of chemical law is the nature of the digestive juices. The digestive juices contain substances that have the power to bring about chemical changes. If we mix starch and water together they will not combine to make sugar, but will remain a mixture of starch and water. If, however, to this mixture we add a little of the secretion of the pancreas, the starch and the water will chemically combine to produce sugar, a new compound. The pancreas produces a substance which is called amylopsin, which has the power of causing a chemical union of the starch with the water. This substance we call an enzyme. It is not alive nor does it need any living environment for its action. If we separate a little of it from the pancreatic juice and put it in a test tube with water and starch, it will cause the union of the water and the starch exactly as it does in the digestive tract. Now we do not know exactly the nature of this enzyme, nor just how it brings this union about; therefore the vital process of digestion is not entirely understood at present. We do know, however, that digestion itself is only a chemical change, and that the same chemical union of the starch with the water can be brought about without the presence of this enzyme. The fact that we do not exactly understand how the pancreatic juice acts in this case is no stranger than the fact that we do not understand exactly how a spark causes a bit of gunpowder to explode. We do not doubt that the explosion of the powder is the result of chemical and physical forces, and there is no more reason to doubt that the combination of the starch with the water, under the influence of amylopsin, is also the result of chemical and physical forces. The same principle holds in regard to the digestion of all other foods in the digestive tract of animals. Each of the digestive juices contains special enzymes, each food is acted upon by enzymes, and in all cases the food undergoes a chemical change. Apart from the fact that they are brought about by these enzymes, there is little or nothing to distinguish between chemical changes taking place in the body and similar changes taking place outside of the body. Digestion, in other words, is a chemical process and controlled by chemical laws. The Absorption of Food. — The digested food passes through the intestine, being forced along by the muscular action of the intestinal wall. As it passes through the intestine it is gradually absorbed, soaking through into the blood vessels that lie within the walls. This process of food absorption involves another set of forces, which are, at least to a considerable extent, either chemical or physical. The primary force concerned is what physicists call osmosis or dialysis, a force which has no special connection with life. If a membrane separates two liquids of different consistency (Fig. 134), a force is exerted on the liquids that causes each to pass through the membrane in an opposite direction, until the constitution of the liquids on the two sides of the membrane is the same. The force that drives these liquids through the membrane is a powerful one, since it is exerted against a high pressure. In Figure 134 a membranous bladder is attached to the lower end of a glass tube. If a solution of sugar is placed inside of this bladder and pure water outside of it, the sugar and the water will both pass through the membrane in opposite directions. Under these circumstances, however, more water passes from the outside into the bladder than passes from the bladder outward. The result is that the bladder becomes more and more filled with liquid, and enough pressure is produced in the bladder to force the water up the tube, in which it may rise to quite a height. This force is known as osmosis, and it is always exerted whenever two solutions of unequal concentration are separated from each other by a membrane. Some substances, like the white of an egg, are not capable of passing through a membrane, and we refer to them by the term colloidal or nondialyzable. Other substances, like salt and sugar, will readily pass through membranes, and we speak of them as crystalline or dialyzable. of the food from the alimentary canal. Undigested foods are not, as a rule, capable of osmosis. Digestion changes them into a condition in which they are soluble and capable of osmosis. After complete digestion the foods in the alimentary canal have been converted into a dialyzable liquid. Moreover, the structure of the intestine is such as to make osmosis a natural process. This can be understood from Figure 135, which illustrates a diagrammatic cross section of the intestinal wall. In such a figure the food occupies the space, in. The walls of the intestine are thrown into little papillae called villi, each of which is covered by a membrane, m; on the other side of this membrane, at bv, there are blood vessels containing the blood, which is a liquid of very different nature from the intestinal contents. Thus it is seen that we have a membrane separating two liquids of different consistency, the blood on the one side and the digestive food on the other. Under these circumstances, the force of osmosis will develop and the material in the solution will begin at once to pass through the membrane from one side to the other. Thus the primary factor in the absorption of food from the intestines is that of osmosis. The physical force of osmosis is not, however, the only factor concerned in the absorption of food. If it were, there would be an equivalent passage of liquid from the blood into the intestine, as well as from the intestine into the blood. Such an equivalent passage from the intestine does not seem to take place, proving that the forces concerned in the absorption of food are not confined to the process of osmosis. Moreover, a careful study of the absorptive process shows that it is much more complex than has been considered. As the food is being passed through the intestinal walls it is changed further in its chemical nature, and by the time it has reached the blood it is in a different chemical state from that in which it left the intestines. While, therefore, osmosis is the fundamental factor concerned in the absorption of food, we are obliged to admit that it is not the only factor concerned, and that there are some phases of the food absorption that we do not yet understand. At the present time we may speak of this unknown factor as the vital factor of food absorption. By this term " vital factor" we simply mean the undiscovered forces concerned. No biologist doubts that the further study of the digestive process will disclose the nature of these vital forces, just as a previous study has explained the early phases of food absorption. In other words, the general belief of biologists to-day is that here the term " vital" is only a means of concealing our ignorance of facts which are yet to be discovered. We have no reason for believing that there are any peculiar forces concerned in the absorption of food. Modern biology thus explains the absorption of food by the application of the same chemical and physical forces that are found elsewhere in nature. Circulation. — The next function in animal life is the circulation of the blood, which carries the absorbed food to the various parts of the body where it is needed. The mechanism of the circulatory system is very simple and is based upon mechanical principles. The circulating blood is contained in a series of tubes, the blood vessels, extending to every part of the body. At the center of this series of vessels there is a pump, the heart, which keeps the blood moving. The heart is like a pump, with valves opening in one direction only. Its structure is such that the expansion and contraction of its walls will open and close the valves, and cause the blood to flow in one direction. By examination of Figure 136, which represents diagrammatically the structure of the human heart, it will readily be seen how the valves work to prevent the backward passage of the blood, and to force it onward when the walls of the heart contract. The blood forced from the heart is received in elastic blood vessels, the arteries, which branch and grow smaller as they pass from the heart, and finally break up into extremely minute and even microscopic vessels. After THE MECHANISM OF THE VALVES A, in the state of relaxation; B, at the time of contraction. In A the open valves admit the flow of blood from the veins into the ventricles. In B the valve connecting with the auricle is closed and the contraction of the heart forces the blood up through the semiluuar valve, as is shown by the arrows. Upon relaxation of the ventricle, the semilunar valve closes, and prevents the flow of the blood back into the ventricle, while the auriculoventricular valve opens and allows blood to enter from the vein. passing these capillaries, the vessels are again united into larger tubes which, by combining with each other, form the large veins that flow back to the heart. The whole action of this system is mechanical; and we can arrange a series of elastic rubber tubes with a central beating force-pump, in a manner to imitate the chief functions of the circulation. Into the details of this matter we need not go; for our purpose it is sufficient to understand that the circulation of the blood is a mechanical phenomenon which can easily be imitated by and blood vessels. It is evident, however, that one phase in the circulation requires further explanation. The force that drives the blood is the contraction of the walls of the heart. Unless we explain the beating of the heart, we have not explained circulation. The explanation of this phenomenon belongs to the study of muscles, for the walls of the heart are nothing more than a chamber made up of a series of muscles. The beat of the heart is, therefore, no more mysterious than the contraction of other muscles, The contraction of the muscles, it is true, we do to the muscles — where again it is placed in a position in which osmotic pressure will be exerted. The blood passes through the muscles in thin-walled capillaries, on the outside of which is a liquid called the lymph (Fig. 137), and thus there is a membrane CLES AND SURROUNDED BY LYMPH. Under these conditions osmosis will take place, and thus the same general force which was concerned in the passage of the materials from the intestine into the blood, will cause the passage of the same materials from the blood vessels into the lymph in the tissues. This lymph lies in direct contact with the living cells, and these living cells can now take from the lymph the food material that they need. This latter function, by which the living cells take the material that they need, is not explained by any known force, so we speak of it as due to what we still call vital force. Respiration. — The absorption of oxygen by the blood in the lungs of a frog or the gills (branchiae) of a fish, and the elimination of the carbon dioxid, are also processes which are explainable by simple chemical laws. The blood contains certain substances which have a chemical affinity for oxygen, and others which have a chemical affinity for carbon dioxid. The red coloring matter, hemoglobin, has a chemical affinity for oxygen, and will absorb the gas whenever it is in contact with it, provided the pressure of the oxygen is sufficient. But this union is a peculiar one. If the atmosphere contains oxygen under the oxygen pressure is low the haemoglobin will let go of the oxygen. As a result, whenever blood passes through the lungs, where there is a large quantity of air and where oxygen is under high pressure, the haemoglobin combines Showing the blood vessels distributed in the wall in position to absorb oxygen from the cavity of the sac and excrete carbon dioxid into it. the glands, or the brain, it finds a condition where there is practically no free oxygen. Here, since the oxygen pressure becomes reduced, the haemoglobin at once lets go its hold upon the oxygen which it has seized in the lungs. The oxygen then passes off rapidly into the tissues and the blood is carried back again to the lungs to get a fresh supply. There is a similar relation between carbon dioxid and the blood; when the pressure of carbon dioxid is high the blood will absorb it, and when the pressure is low, the blood will let go its hold upon the carbon dioxid it has absorbed. In the active tissues and cells, carbon dioxid is present in considerable quantity, as the result of the activity of the tissues. When the blood flows through these tissues, it therefore absorbs carbon dioxid, and then goes back to the lungs loaded with this gas. In the lungs, however, it comes in contact with the air, in which the carbon dioxid is present in very small quantities only. Under these circumstances the blood can no longer hold the carbon dioxid. This gas passes into the lungs and is exhaled in the next breath. Up to this point in the study of the activity of the living body, there is no special difficulty in reaching the following conclusions: (1) So far as relates to the general problem of the transformation of energy, the body neither creates nor destroys energy, but simply transforms one kind into another. (2) So far as concerns the functions now considered, the laws of chemistry and physics furnish for them an adequate explanation. It is necessary, however, to question further a function of life in which the mechanical relation is less obvious. The nervous system controls all the operations of the body as an engineer controls an engine. Is it possible that this phase of living activity can be included within the conception of the body as a living machine? The Nervous Functions. — The primary question is whether there is any correlation between nervous force and other types of energy. For this purpose it will be convenient to separate the phenomena of simple nervous transmission from those that we speak of as mental phenomena. The former are simpler and offer the greater hope of solution. Nerve impulse. — If we are to find any correlation between nervous force and physical energy, it must be done by finding some way of measuring nervous energy and comparing it with physical energy. There has been devised as yet no satisfactory way of measuring the nervous impulse directly. In the experiment of keeping an individual in a large box where all of the energy exhibited by his body can be carefully and accurately measured, the attempt has been made to get some indication of the energy involved in nervous phenomena. But the results have been quite negative. When in these boxes an individual simply arises from his chair, the measuring device of the apparatus is accurate enough to show distinct indication of the expenditure of energy in this very simple motion. But when this person is allowed to remain seated, not performing any bodily action, but working hard with his brain, as for example in writing a difficult examination, there seems to be exhibited no extra energy, so far as can be determined by the measurement recorded with this apparatus. In spite of all attempts that have been made, it has hitherto been impossible to get any indication that the use of the nervous system involves the expenditure of energy. This is probably due to the fact that the amount of energy thus involved is altogether too small to be recorded in the coarse apparatus which has been devised for use in these experiments. That there is some correlation between nervous force and physical energy is fairly well proved by experiments along various lines. The impulse that passes along nerves may be excited by a variety of forms of ordinary energy. Any mechanical shock, a little heat, or an electrical shock will develop a nervous impulse. Now, if forms of physical energy applied to a nerve are capable of giving rise to a nerve stimulus, the inference is certainly a legitimate one that the nerve is simply a bit of machinery which converts one kind of energy into another, i. e., converts physical energy into nervous energy. If this be the case, of course it is necessary for us to regard nervous force as one of the correlated forms of energy. Other facts point in the same direction. Not only can the nerve stimulus be developed by an electric shock, but the strength of the stimulus is, within certain limits, proportional to the strength of the shock producing it. Conversely, we also find that a nerve stimulus produces electrical energy. In an ordinary nerve, even when it is not active, there are slight electric currents that can be detected by very delicate apparatus. If the nerve is stimulated, these electric currents are immediately affected in such a way that they may be increased or decreased in intensity. These variations in intensity are sufficient to be visible by delicate apparatus, and by using a galvanometer we can actually measure the passage of an impulse passing along a nerve like a wave, and can approximately determine the shape of the wave. Since the nervous impulse can be started by some other form of energy, and since in turn it can modify ordinary forms of energy, we cannot avoid the conclusion that the nervous impulse is a special form of energy developed within the nerves. It is possibly a form of wave motion, peculiar to the nerve substance, but correlated with and developed by other types of energy. This of course would make the nerve fiber a simple bit of machinery. If this conclusion is correct, it will follow that whenever a nerve impulse passes over a nerve a certain portion of the food supply in the nerve must be broken to pieces to liberate energy, and this would also be accompanied by the elimination of carbon dioxid and heat. But although careful experiments have been made, it is as yet impossible to detect any rise in temperature when a nerve impulse passes over a nerve. This is not, however, an objection to the general theory, since the nerve is such a small machine that it would be doubtful whether our tests are delicate enough to recognize any rise in temperature even if such a rise occurred. The total energy of the nervous impulse is too small to be detected by our rough instruments for measuring heat. All evidence goes to show that the nervous impulse is a form of motion, and hence is correlated with other forms of physical energy. The nerve is a very delicate machine and its total amount of energy is very small. A tiny watch is more delicate than a water-wheel, and its actions are more closely dependent upon the accuracy of its adjustment. The waterwheel may be made very coarsely and still be useful, while the watch must be fashioned with extreme care and nicety. Yet the water-wheel transforms vastly more energy than the watch ; it may drive the machinery of the whole factory, while the watch can no more than move itself. But who can doubt that the watch as well as the water-wheel is governed by the law of the correlation of forces? So the nerve machine of the living body is delicately adjusted, easily put out of order, and its actions involve only a small amount of energy; but it is probably just as truly subject to the law of the conservation of energy as are the more massive muscles. Sensations. — Up to a certain point, sensations can also be related to the general problem of the conservation of energy. The frog has a piece of apparatus, which we call the ear, capable of being affected by the vibrating waves of the air. It is made of parts so delicately adjusted that the air waves set them in motion, and this motion starts a nervous stimulus which travels along the auditory nerve to the brain. Whenever air waves strike the frog's ear, they will excite in his auditory nerve impulses which will travel from the ear to the brain. The ear is simply a delicately poised apparatus, so adjusted that when it is stimulated by vibrating air it is discharged like a bit of gunpowder, and a nervous impulse is produced. In all of this we are plainly dealing with nothing more than the transformation of one type of energy into another. In the same way the optic nerve has at its end, in the eye, a bit of mechanism that is easily excited by the light waves, and when such waves strike the eye there will be started in the optic nerve a series of impulses which pass towards the brain. Thus each sensory nerve has at its end a bit of machinery designed for transforming certain kinds of external force into nervous impulses. The second phase of the sensation is, on the other hand, not explainable by any mechanical principle. When the impulse started in the ear reaches the brain, it is converted into what we call a sensation, i. e., a consciousness, a perception, a distinct feeling. In our attempt to trace external forces we can follow the stimulus to the brain, but there we must stop. We have no idea how a nervous impulse is converted into sensation. By no means of thinking can we conceive of the correlation of the sensation itself with any form of physical energy. It is true that the mental sensation is excited by the nervous impulse, and true also that in the development of the individual the mental powers develop parallel with the growth of the nerves and brain. Moreover, certain visible changes occur in the brain cells when they are excited into mental activity. All of these facts point to a close association between the mental side of sensation and the physical structure of the machine. But they do not prove any correlation between them. The unlikeness between the mental and physical phenomena is so absolute that we must hesitate about drawing any connection between them. It is impossible to conceive of the mental side of sensation as a form of wave motion. Mental functions. — If we go farther and try to consider the other phenomena associated with the nervous system — the more distinctive mental processes — we have absolutely no ground for comparison. We cannot imagine thought measured by units; and until we conceive of some such measurement we can get true mental processes and physical energy. Reproduction. — The process of reproduction would seem to be one which cannot possibly be explained as the result of chemical and physical forces. Nowhere else in nature do we find this property, and in this respect living organisms cannot be compared to any other machine. Nevertheless, in its simplest form reproduction also permits a partial explanation. When a unicellular organism, like the Amoeba (Fig. 19), feeds and grows, it increases in size. The increase in size is due to the transformation of the chemical material of its food into a material like that of the animal, and as these new materials accumulate, the bulk of the animal becomes greater. As the animal increases in bulk, it needs a larger supply of oxygen to keep up its life processes, since all life processes require the expenditure of oxygen, and the amount of oxygen needed is dependent on the bulk of the animal that is to be supplied. Now it is a principle of mathematics that the bulk of a solid object increases as the cube of its dimensions, whereas its surface increases only as its square. Since this Amoeba is obliged to absorb all of its oxygen through the surface of its body, it follows that the surface adapted for absorbing of oxygen increases only as the square of its diameter, while its need for oxygen increases as the cube. It is evident from this that in time the surface will no longer be sufficient to absorb enough oxygen for its increasing size. When this time comes the animal must either stop growing or devise some way of increasing its absorptive surface. What happens is that the bit of living jelly simply breaks in two. The result is that once more the absorbing surface is large enough to accommodate a larger bulk, and the animal again begins to grow. This explanation of reproduction shows how the process may have been due to overgrowth. Since all kinds of reproduction are forms of division, it follows that if we can explain the simplest division upon the basis of physical and chemical forces, we have at least reached an intelligible understanding of the process. The more complicated phases of reproduction are, of course, not explained by this simple process, not even the division of a cell which we have seen to be very complicated; but if we can explain this strange phenomenon even in its simplest form, we have done much toward explaining the functions of reproduction in accordance with the principle of chemical and physical forces. VITAL FORCE OR VITALITY With all of the explanation given, we cannot believe that we have reached a solution of life. There is clearly something lacking, for we still have to ask the question why it is that all of these chemical and physical forces play together in such harmony within the living organism. Nowhere in nature can the physical forces automatically carry on such functions except in living organisms. It is quite possible to compare the animal body to a locomotive at rest. But a locomotive at rest, even if its boilers are filled with steam under high pressure, ,will never exhibit any activity without an engineer to control the forces that are contained in the machine. The living organism has no outside engineer. What is there in the living organism that corresponds to the engineer starting and directing the machinery? To this question we have no answer. Some biologists claim that there is no more need of an engineer for a living organism than for a clock, these scientists assuming that the complexity of the machine gives it automatic activity. Others would believe that in a living being there is something that is absent in other machines, to which they would give the distinct name of vitality. There are certain functions of this machine, like sensation, thought, etc., that do not seem to be explainable by chemical and physical laws, and one class of biologists would group these functions together under the general term of vitality. Others would claim that vitality has no real meaning, but is only a name given to a combination of functions possessed by certain machines. The question whether there is anything like vital force has not yet been solved, and it is by no means certain that it ever will be. If it were possible for scientists to manufacture a cell exhibiting the properties of life, the great problem of biology would be settled. This has never been done, and we must leave the question of the meaning of vitality without an answer. It cannot be insisted upon too strongly that, while we may compare the living organism with a machine, it is unlike any other machine. The living machine consists of a number of small independent units called cells, each one of which has its own independent power of growth and reproduction. The whole combination, too, has functions possessed by no other machine. Complex and Simple Living Machines. — An animal as high in the scale as the frog is evidently an extremely complicated machine. Not only is it made up of a large number of parts, each with a different function, but each of these parts is made up of a number of tissues, each having a different relation to the organ in general; and furthermore, each of these tissues is made up of hundreds, thousands, and perhaps millions of living units, called cells. It seems plausible to think that, if we could get rid of the complexity seen in the frog, we might approach nearer to primitive life. In other words, if we can get at the simplest unit of life we might be able to understand many mysterious phenomena, since we should thus approach life in its simplest form. For this purpose biologists have turned especial attention to the life of the individual cell, since this is the simplest known unit manifesting life. It is clear, however, from the study of cells in Chapter II, that the mysteries of life phenomena are not solved by reducing them to the operations going on inside of the single cell. Although some cells are simpler than the one shown in Figure 9, still it represents practically the simplest form of machinery with which we are acquainted that is capable of carrying on the functions of life. But such a cell itself is a complex machine, and if we study in it the processes of life, it becomes evident that the functions of this single machine are as mysterious, although not so complex, as are the functions of the whole body of the frog. In other words, getting rid of the complex machinery of such a highly built organism as the frog does not help us at all towards the [solution of the' problems of biology; for it is no easier to understand the processes of life going on in the single cell than it is to understand the processes of life going on in the multicellular animal. While the study of single cells and their functions has enabled us to understand the processes 'of life in many respects much better than before, it has not solved the problem of what life is, nor made it any easier to get rid of the idea that living organisms show certain powers not possessed by machines, — powers so mysterious that we must acknowledge our inability to explain them, and must, for the present at least, include them under the general term of vitality. The recognition that the cell is such a complex mechanism has recently led to the attempt to analyze it into smaller and simpler units. Whether any success will follow this attempt it is too early to predict. For these reasons it is useful still to retain the term "vital force"; not meaning by this to imply that there is any special force in living things, uncorrelated to forces of nature, but simply indicating our present lack of knowledge. By vitality we refer to the guiding principles which regulate the play of chemical and physical forces in this living machine, and which determine the processes of reproduction, which lie at the foundation of that side of living organisms and their functions which we call mental. We certainly have not yet explained all the factors connected with life processes, and we can therefore most satisfactorily comprehend them under the term "vitality." With this understanding, it is perfectly legitimate to retain th* term "vital force" for those phases of life processes which are not included in any mechanical conception of life. SUMMARY 1. All physical energy exerted by the living organism is distinctly correlated with other forms of energy, the energy of plants coming from sunlight, and that of animals coming from the energy stored by plants in their foods. To this extent, therefore, a living organism is a machine. 2. Nearly all life functions are explainable by chemical and physical laws. This is certainly true of such functions as digestion, assimilation, circulation, excretion, respiration, etc. 3. Some of the functions of the living animal are not yet explained by chemical or physical forces. This is true of the absorption of the food from the intestines, and the power which the living cells have of taking from the lymph the particular form of food that they need. We may gather these factors for the present under the term "vital forces" of the living organism. After we have learned thoroughly to understand them and their method of action, we may find these processes are also to be included under the general laws of physics and chemistry. There is really no good reason for questioning that the living organism is a mechanism, simply because there are some functions which are at present unintelligible. 4. In the mental power of the living organism appear functions which are not found in any machine. The functions of mind, sensation, and thought are so absolutely unique, and so different from any other type of energy, that no one has ever conceived the possibility of correlating them with physical energy. 5. Only the living machine has the power of reproducing itself. It is true that some forms of the process of reproduction may be explained simply as a result of growth, and growth as due to the chemical forces that are at play within the living organism. But it nevertheless remains true that no other mechanism in nature has the power of dividing itself into two parts, each of which develops into an individual like the first. Taking all these things into consideration, it is evident that, so far as physical forces are concerned, the living organism is a machine, and, like other mechanisms, transforms one type of energy into another. But the living organism possesses additional powers, some of which may be explained some day, while others, like thought and reproduction, appear to be insoluble and place the living organism in a category by itself. If the living organism is a machine, it is also more than a machine, and cannot be compared with any other mechanism in nature. It may be instructive to ask whether we can define life. Although many attempts have been made to give the definition of life, all that can be done is to describe some of its characteristics. The primary characteristic of living things is a constant activity, and if we mean anything by the term "life," it must be the guiding force that controls these activities. Our understanding of the word "life" is certainly obscure; but, so far as it means anything, it refers to the engineer that controls the engine, the machinist that directs the activity of the machine, the force that guides the activities of the animals or plants. What this guiding force is we do not know. Some have called it "vital force," and have believed it to be a special force in nature. Others insist that there is no special force in living things, any more than there is in a clock or a watch. Whether there is any force in nature that can properly be called vitality is not yet settled, but it is certain that the phenomenon which we call life is manifested only in those machines which we call animals and plants, and which come from no source except that of previously existing animals and plants. We have no evidence that this force can be created in any way except from life which previously existed. The life force is capable of indefinite growth and expansion, since a fraction of life force, in the form of any single animal, may produce hundreds of thousands of offspring, each of which has the same amount of life force as the original ancestor had. But this life force, although capable of expansion and growth, has, so far as we know, no method of origin except from previously existing life. We must look at life as a unique manifestation of force, standing by itself. This is perfectly consistent with the recognition of the fact that the animal body is a machine, acting in accordance with the principles of conservation of energy, and that a living organism simply transforms one type of energy into another. This view is also equally consistent with the suggestion that there is a special force, which we call life, directing the activity of these machines. At all events, for the present we can go no farther in the discussion of the question than this. Life is the directive agent which controls the activity of the living machine, and death means the disappearance of this controlling agent; though what is meant by its disappearance we cannot say, any more than we can tell what caused its appearance in the machine in the first place. The question of the real significance of life and death is still unanswered by science. THE ORIGIN OF THE LIVING MACHINE NOT EXPLAINED EVEN if it were possible to explain perfectly the working of the organic machine by mechanical principles, this would not explain life. As we have noticed in Chapter I, living organisms come into existence to-day only as the result of reproduction from previously existing organisms. Granting that animals and plants have the power of reproduction, we have still to ask how these complicated machines came into existence. One of the most revolutionary eras of thought has arisen in the last fifty years as the result of the attempt of biologists to explain how the innumerable animals and plants have been brought to their present condition of existence. Of the primal origin of life we have no knowledge, and it must be admitted we have little hope of ever gaining any. Nor have we much idea of the first living things that appeared in the world. Probably they were of the lowest type, possibly even simpler than unicellular forms. One thing seems certain : the first living things must have been endowed with the properties of growth and reproduction; for without these powers they would not have been alive. We know of nothing simpler than cells possessing these powers, and we cannot therefore conceive the beginning of life as anything simpler than a bit of reproducing protoplasm. THE FORCES WHICH HAVE PRODUCED ORGANISMS It has been the aim of biology to show how the endless series of complicated animals and plants, now found in the world, have been produced from the simplest forms of life. Living organisms possess three properties, by the interaction of which the present world has been formed. These are reproduction, heredity, and variability. That these three factors are necessarily concerned is evident. Without reproduction there could not have been produced the successive generations which have followed each other; unless the successive generations had, by heredity, reproduced the characters of preceding generations, there would have been no connection between one type and another; and lastly, if the successive generations had not shown variability, organisms would have remained in a stationary condition, without any opportunity for change. That these forces have been sufficient to account for the development of the organisms inhabiting the world, i. e., to explain the origin of the living machines, is not so evident. To show how the result has been brought about has been the endeavor of biological discussion for the last half-century. The property of reproduction we have already considered. The consideration of heredity and variation remains. Heredity. — The general rule in reproduction is that the offspring grow into individuals like their parents, the repetition of the parent being spoken of under the name of heredity. Heredity must not be looked upon as any special force or law, but merely as a word expressive of the fact that one generation repeats itself in the next. It is evident that this process of repetition cannot be exact, since most animals have not one but two parents, and an individual that has a father and a mother cannot be exactly like both of them if they are in the slightest degree unlike. Since no two animals are exactly alike, the natural conclusion would be that the offspring would be a compromise between its two parents. Successive generations are thus not identical, but constantly show differences from their parents. Heredity means, then, that successive generations resemble their parents as closely as is compatible with the fact that the individual has two parents, and cannot be like both. THE ORIGIN AND DEVELOPMENT OF ORGANISMS 327 Variation. — The offspring of any animal is never exactly like either of its parents. Sometimes it is a compromise between them; sometimes, for certain reasons that we do not understand, it is quite different from either. The reasons why any peculiarity may reappear in successive generations, are probably partly due to processes connected with the reproductive functions, but they are also partly due to the effect of the environment in which the animal lives, upon the structure, the nature, and the life of the organism. Whatever be their cause, the points in which animals and plants differ from each other, or from their ancestral types, are known under the general name of variations. The life of an individual which is produced by sexual reproduction may be said to begin at the moment when the sperm fuses with the egg, as shown in Figure 121. Previous to this, there were only the sex cells produced by two parents; but from this point there is a new individual resulting from the union. Variations which appear in an animal or a plant may be caused by influences acting either before or after the union of the sex cells. If the variation is caused by influences acting before this union, we speak of it as a congenital variation (Lat. con = together + genitus = produced) . If, however, the variation is developed in the animal after the fusion of the sex cells, and thus produced by influences acting directly on the new individual, we speak of it as an acquired variation. Although this distinction between acquired and congenital variations may be merely a matter of a short time, nevertheless the facts show that there is a very great distinction between characteristics produced before and after this period. Variations which are produced by influences acting before the fusion of the sex cells (congenital variations) are practically certain to be handed to the subsequent generations by heredity. Variations which arise subsequently, and affect the new individual only (acquired variations), are practically certain not to be handed on to the following generations by heredity. CONFORMITY TO TYPE Nothing is more marvelous, and at the same time more evident, than the fact that the individuals of generation after generation resemble each other so closely. Not only in general features, such as the .structure of the body, the presence of the proper number of legs, arms, etc., does the child resemble the parent, but in an infinite number of details, — in the color of the eyes, the color of the hair, and even in many obscure traits. The child may inherit from its parents the tendency to become bald-headed at a certain age, or at a certain time in life to put on a large amount of fat, etc. Through an endless series of details, the child has a tendency to repeat its parents' characteristics. Since scientists have begun to study life phenomena, they have always puzzled over these marvelous facts, and have advanced many speculations and theories to explain the similarity of the offspring to its parents. Some of these theories have been ingenious, some have been plausible, but all have been imaginative. For the last century, particularly, this subject has been a matter of speculation; but until about 1884 none of the various speculations had sufficient plausibility to receive any general acceptance. In 1884 there appeared a little essay by August Weismann entitled "On Heredity" which advanced a new suggestion for the explanation of heredity. In some of its phases this new theory had been antedated by the writings of Brooks in America and Galton in England. Nevertheless, it did not appear in a clear-cut form until Weismann's essay came out in 1884, and the theory has been almost universally known as Weismann's theory of heredity. From the time of its appearance, the explanation commanded wide acceptance and extended discussion. As year by year has passed, the theory has been more and more substantiated by facts, until at the present time it has practically universal acceptance. While it cannot be claimed that we have a complete explanation of heredity, it is beyond ques- tion that our present understanding gives us an intelligent grasp of the law of conformity to type. Future experiments and discussions may modify our present ideas in many details; but it is practically certain that the fundamental law, in accordance with which successive generations tend to resemble one another, is now so well understood that it is not likely to be changed greatly by subsequent investigation. The principle underlying this conception of Weismann's is spoken of as that of the continuity of germ plasm. A brief resume of the theory is as follows : — Reproduction by Simple Division. — It is not difficult to understand that when an animal multiplies by simple division, the offspring will be similar to each other. When, for example, an Amoeba divides, it would be almost impossible to see how the two parts should be otherwise than alike, since they are each half of the same individual. So, too, when yeast multiplies by budding, it is not difficult to understand that the buds which grow from the side of the older cell will be like the old cell. If a cell is thus capable of dividing, it would be very difficult to see how the bud could in any degree be unlike its parent, except as it may be changed by future conditions. So, too, with those multicellular animals and plants that multiply by the process of budding, the conformity to type is natural rather than marvelous. When Hydra (Fig. 69) produces a small bud on its side, which grows to the size of the original and then breaks away, it is not difficult to see why the bud should be like the parent, for it would be difficult to understand how it could be otherwise. So, too, when a branch of a tree is broken off, takes root, and grows into a new tree when placed in the ground, it would be difficult to understand why the new individual should be different from the parent tree, since it is really a part of it. In all of these cases the conformity to type is natural and presents no special puzzle, beyond the fact that animals and plants have the power of dividing and reproducing at all. Conformity to type in plains itself. Reproduction by Eggs or by Spores. — When we come to the reproduction of the multicellular animals and plants by eggs and spores, the problem, however, becomes more difficult. The egg or the spore is a single cell, and from this single cell develops the many-celled adult. When this cell divides into many cells, which become differentiated and form themselves into new individuals, why should these adults be repetitions of the parent? There can be only one answer. This single cell, whether an egg or a spore, must contain in itself, in some form or other, features representing the whole of the animal from which it came. We may place two eggs in an artificial incubator and hatch them by artificial heat under identical conditions; one of them becomes a duck and the other a chick. It is absolutely impossible to avoid the conclusion that in one of the original eggs there were present potentially the characters which would produce the duck, and in the other the characters which would produce the chick. This of course indicates a complexity in the egg far beyond the possibility of our imagination. But we are logically forced to the conclusion that the facts are as stated. An egg or a spore undoubtedly contains potentially all of the characters of the animal into which it develops. \ ' Germ Plasm. — For convenience in discussion it is agreed to call this substance, which is present in the egg and contains the hereditary characters, by the name of germ pksm. We have seen, in Chapter XII, reasons for believing that this material is chiefly, if not wholly, confined to the part of the egg that we have called the chromatin. We have also learned that the chromatin is capable of growing and dividing and has the power of self-perpetuation. Using the term "germ plasm" for this material that possesses the power of determining the development of a new individual, it follows that the germ plasm has the power of growth. In other words, this germ substance, when properly nourished, continues to increase in bulk and may grow indefinitely, becoming more and more abundant, but not essentially changing its character. If We admit this power of the germ plasm, the problem of the conformity to type obtains a ready explanation; for some of this germ plasm is simply handed on from one generation to the next, constantly growing in bulk, but not changing its character. At any stage in the development of the race, there is present in each individual a certain amount of germ plasm, containing in itselt the general race characteristics. The way that this is brought about is believed to be as follows : — The diagram shows how the germ plasm in the egg, ov, divides: one part, sp, develops into the next generation, while the other part, the germ plasm, gp, becomes stored in its reproductive bodies, ov1 and s. In 6, the germ plasm from an egg is combining with the germ plasm from the sperm, s1, in sexual fertilization. germ plasm; Fig. 139 gp. It is the presence of this germ plasm that makes it possible for the egg to develop into a new individual like the parent. An early step in the development of this egg toward the adult consists in the division of this germ substance into two parts. The two are essentially alike and both contain the same characteristics; but each has a different purpose. One of them remains exactly as it is at the start, increasing by growth but not changing in nature. Thus this substance remains as germ plasm, gp. The other bit of the original germ olasm, however, soon begins to develop into a new individual, and in distinction from the other germ plasm is called somaplasm (Gr. soma = body + plasma = substance), sp. With the development of the egg the dormant power, which this somaplasm possesses, begins to show itself in an active form. As a result there appears a new individual; the second generation (Fig. 139, 5) arises from this somaplasm. The second generation, in other words, unfolds the characters which lie dormant in the bit of germ plasm from which it was derived. As this individual develops, the other part of the original egg, which remains as modified germ plasm, finds lodgment within the body of the new individual, and thus, when the somaplasm has developed into an adult, that adult contains, stored away somewhere in its body, a bit of this dormant germ plasm of the original egg. Since this germ plasm has not changed its nature, but has only increased in amount, its nature is of course exactly the same as that of the parent germ plasm. When later the second generation produces eggs, some of this germ plasm, which has been stored away in the body of the second generation, passes into each of the eggs; Fig. 139, 4. If we admit that the germ plasm has certain dormant qualities, capable of developing into an adult, it will of course follow that all of the individuals produced from bits of this germ plasm will be alike. It is thus inevitable that the third generation should be exactly like the second, since both the third and the second generations have developed from two different parts of the same germ plasm. As long as the process continues, it is evident that successive generations will be alike. Part of the germ plasm at each reproduction is handed on unchanged to the next generation; it is retained by that generation through its life, and then handed on again to the next generation. Successive generations thus carry a continuous germ plasm. The race is the result of the continuous germ pla^m; the individual is simply the unfolding of a bit of it, the somaplasm, which is set aside to develop into an individual for the purpose of carrying for future generations the germ plasm which is to continue the race. Heredity is thus due to the continuity of the germ plasm from generation to generation. It is seen that, in accordance with this theory, heredity is simply a name given to a process of handing on from age to age a bit of marvelous material, the germ plasm, small bits of which have the property of developing into individuals. As long as this germ plasm is handed on unchanged, it will produce a succession of generations identical with each other, and there will be a conformity of type. It will be seen thus that the child does not actually inherit anything from its parents; the child and parent are alike because both develop characters that are present in the continuous germ plasm. Variations in Germ Plasm are Inherited. — It is evident that any modification of the germ plasm must permanently affect the race. If at any period the germ plasm should be changed so as to produce in it a new character, the new character will inevitably appear, not only in the next generation, but in the following generations. Characters which appear in the germ plasm at once become, therefore, race characters, handed on with certainty, unless something subsequently causes their disappearance from the germ plasm. Variation in the Individual not Inherited. — It is equally evident that any variation occurring in the body, but not in the germ plasm, will have a very different effect upon the race. The individual is only a trustee of the germ plasm which is stored away somewhere in his body. Among animals, the germ substance is largely stored away in the ovaries and sperm glands; among plants it may be more distributed, but here also it is probably located in certain parts of the plant. If we admit that the individual has nothing to do with this germ substance except handing it on to the subsequent generations, it is evident that no special change which affects the individual himself will be transmitted to the subsequent generations. If an individual should sustain the loss of an arm, it would affect his own life, but would have no influence upon the germ substance which he has received from the egg, and which he is simply holding hi trust for the next generation: his offspring will not be one-armed. So with any peculiarity developed during life, as the result of life habits or as the direct result of environment. Characters which are impressed simply upon the individual himself will have no opportunity of being transmitted to subsequent generations. Congenital and Acquired Characters. — Thus it will be seen that variations are of two distinct types: (1) variations which appear in the germ plasm and which therefore affect subsequent generations; (2) variations which appear hi the body of the individual and which are not in the germ plasm, and hence cannot affect subsequent generations. These two types of variations have been recognized for a long time, but they were never sharply distinguished until Weismann's conception of heredity brought them out hi such clear contrast. Characters which result from modification of the germ plasm, and hence are inevitably transmitted by heredity, to-day are commonly called congenital characters. Congenital variations are fixed in the germ plasm and are therefore inevitably transmitted by the process of heredity.- On the other hand, characters which are developed as the direct result of the environment, such as loss of limbs, or changes resulting from food habits, climate, etc., are commonly known by the name of acquired characters. The term is not a good one, for all characters are acquired at some time; but this name has been used hi the discussion of the last quarter of a century, for such variations. From what has just been stated, it is evident that acquired characters, if they do not become a part of germ substance, will not be repeated in subsequent generations. Acquired characters, therefore, which an individual animal or plant develops as the result of the conditions of the environment in which he lives, would affect his body during life, but would not be expected to affect his progeny; and acquired characters should not be transmitted by heredity. This conclusion, quite at variance with the beliefs of twenty-five years ago, has been subjected to long and exhaustive study, as a result of which the belief in the inheritance of acquired characters has gradually disappeared. The conclusion has been vigorously disputed, and, since the advancement of Weismann's theory of heredity, the most active search has been made for proof or disproof of the idea that acquired characters can be inherited. While many apparent instances of such inheritance are easily found, they all prove illusive when carefully studied, and biologists have practically agreed that there is no good evidence that acquired characters can be transmitted to subsequent generations. While the possibility of the inheritance of acquired characters cannot yet be positively denied, it is quite generally believed to-day that it does not occur. This conclusion has far-reaching results, for it entirely changes our conception of the relation of parent to offspring. Heredity and the Union of Sex Cells. — We are in a position now to appreciate a little more fully the significance of the factor of the union of sex cells in sexual reproduction. Thus far heredity has been spoken of as associated with eggs only. A succession of similar types in successive generations can be explained as due to a division and transmission of a continuous germ plasm. But the result of such a process would seem to produce a series of like individuals, without any variation in successive generations. Successive generations are, however, not alike. Indeed, the development of animals and plants is dependent upon the fact that successive generations show more or less divergence from the original type. It is here that we see one reason for sexual reproduction. In Chapter XII we have noticed that the reallj- significant feature of the union of the egg and the sperm lies in the fact that each of these reproductive cells throws away part of its chromatin in order to make room for a similar amount brought to it by the other of the two uniting sex cells. If, as we have seen reason for believing, the chromatin contains the germ plasm, this process has a most natural interpretation. The maturation of the egg and the union of sex cells bring about a new individual in which the germ plasm is a mixture from two individuals (amphimixis) (Gr. amphi = together + mixis = a mixing) . The result is that the germ plasm of the subsequent generations will be different from that which was present in either of the parents of the last generation, since it will be a mixture of the two, and, if the parents are in any degree unlike, the mixture of their germ plasms will not be exactly like that of either. It would be impossible for any such complex things as two bits of chromatin to be mixed twice without producing differences in the mixtures. In other words, the following generation will show variations from the last. Since, however, this mixed germ plasm will be handed on to form the germ plasm of the next, and all following generations, it will follow that the variations which thus appear will be handed on indefinitely by the. process of heredity, and such new characters as appear from the mixture of two germ plasms will remain fixed in the race. With the next reproductive generation this mixed germ plasm will again be combined with another mixture from another individual, and still further variations will appear. Successive generations will thus tend constantly to be more or less unlike their parents. Sex union of eggs and sperms, therefore, appears to be a device to bring about variation and divergence from type. If this conclusion is correct, we should expect those organisms which multiply by sex union to show a greater amount of variation than those which multiply by the asexual process of simple division; and this appears to be a fact. If a horticulturist wishes to preserve unchanged a type of plant which he has found, he contrives to multiply the plant by the asexual method of budding, grafting, or cuttings. As long as this method is continued the plants remain essentially constant. If, however, he wishes to obtain new types, he adopts the method of planting the seeds. Seeds, as we have seen, come from the sex process of reproduction, and the offspring which come from seeds show a far greater tendency to variability than those which come from buds by the asexual process. It is the general conclusion from observation that variations are more common among organisms multiplying by the sexual process. With this understanding, one purpose and function of the union of the sex cells becomes intelligible. DIVERGENCE FROM TYPE The term "divergence from type" is the exact opposite of the term "conformity to type." It is no less evident that animals and plants tend to diverge from the race type than it is that they conform to type. The reconciliation of these two contradictory facts is that though, in general, successive generations conform to the type of the race, the individuals show more or less variation from each other, and, moreover, the whole race is slowly changing, so that the type itself in time undergoes modifications. Individual Variations. — An infinite number of slight differences are found between individuals of the same species. This fact is clear to everyone who is at all familiar with animals. In the human race, it is well recognized that no two individuals are exactly alike, and the same thing is equally true among all species of animals and plants. The different individuals of the same species differ in size, color, habits, and in an infinite number of minor points, like the length of legs, the length of hair, the size and shape of leaves, flowers, etc. Indeed, there is no part of an animal or plant that does not show more or less of such variation. It is so evident that it needs no further discussion. While the different individuals conform to the type of their species in general character, in numerous details they differ from each other in almost endless fashion. Race Variations. — In addition to individual variations, the whole species may show a tendency to diverge from its original form. Races are either slowly or rapidly changing from their previous condition, so that if the members of any race living to-day are carefully compared with those living in a previous period of the world's history, it will be found that the whole race has undergone a general change which has affected all members. Such race variation commonly occurs by what is known as divergence. By this is meant that the descendants of one type have, by this race variation, diverged in several directions, more or less different from each other. This is explained by the assumption that the descendants from any animal remain neither exactly like their ancestors nor like each other, and that different lines of descent depart from the original type in different directions. Examples of this are numerous, but for illustrative purposes two well-known instances of such divergence will be briefly mentioned. Breeds of pigeons. — For some centuries, breeders of pigeons have been very much interested in improving different strains of these birds, and pigeon fanciers have been careful to breed together individuals showing characters that appeal to their fancy. The result has been that the pigeons have undergone many profound changes from their original type. The original pigeon, from which all of our domestic pigeons came, is fairly well known to be essentially the same as the rock pigeon of India, a bird gray-blue in color, with bars on its breast and a tendency to perch on rocks, but never on trees. Historical and scientific evidence shows that all the numerous strains of pigeons with which our pigeon fanciers are familiar to-day have been derived from this bird. The tumblers, the fantails, the pouters, and hosts of others, have all been descended from this primitive ancestral form. The differences between these varieties are very numerous, including variations in color, length of bill, size, wings, tails, and many other points, thus been produced artificially, are greater than differences found among many of the wild birds that are regarded as belonging to distinct species. In the case of the pigeons, it is known from historical evidence that these different strains have all come from a common type by methods of breeding. The dogs. — Another example, perhaps even better known, is that of the breeds of dogs. Dogs have been domesticated for a period almost as long as man has been civilized. At the present time the variety of dogs is very great, ranging in size from the great Newfoundland to the tiny poodle, and varying in color, type of hair, disposition, and almost every other respect. We can hardly conceive of two animals being much more unlike than the tiny lap-dog and the massive bloodhound or mastiff, and it is hardly possible to believe that these animals have all come from the same type. But the most careful study of the characters and history of the breeds of dogs has led to the unquestioned conclusion that all forms of domestic dogs with which we are familiar belong to one species of animal, and all came from the same type far back in history. Some varieties of dogs, like the dingo of Australia, belong possibly to a different species; but all of our common forms belong to one species and have been derived from the same fundamental stock. Here, as in the case of pigeons, the breeds have been the result of a long series of unconscious breeding experiments. Different families of human beings have had a liking for certain types of dogs and have kept by them such individuals as pleased their fancy. These have been bred together and their masters have selected from the pups those which most pleased them. This process has gone on, similar individuals being bred with each other over and over again, until the whole race has become slowly changed. Different types of dogs were selected for different purposes. The shepherd took a fancy to a different type of animal from that which was most desirable as a house dog. By selecting the dogs who could drive sheep, or the big dogs, or the fierce dogs, or the little dogs, etc., and breeding together those nearest alike, there have been produced the different types which we have in our world to-day. Recognizing, however, that all of these types of dogs belong to the same species and must have come from a single common type, the strains of dog illustrate excellently well what is meant by race divergence. Both of these examples have been chosen from domestic animals. There is no reason for doubting that the same facts may occur in nature and that under proper conditions in nature there may be a series of race variations similar to those found in domestication. Perhaps divergence in nature is not quite so rapid or so extreme as it is when controlled by the fancy of the breeder, but the same general facts hold true. In nature as well as under domestication, races are undergoing a constant series of changes, sometimes slow, and sometimes rapid. Race variations must be variations of the germ plasm. Individual variations, as we have seen, will affect the body of the individual but will not affect the germ substance. From this it follows that individual, acquired variations will not be transmitted by heredity and will therefore have no lasting effect on the race. On the other hand, if the race is to undergo a change, as we have just seen that it does, this must be due to modifications in the continuous germ substance. Hence it follows that the only variations that can continue in the race and can be carried on for successive generations, are those that affect the germ material itself. Race variations are therefore necessarily germ variations. The Divergence from Centers. — A little thought will show that the result of divergence of the descendants of any type in different directions will, in the end, produce extremely wide diversity among animals and plants. If the descendants of any animals diverge in two directions, and then later their descendants again diverge from each other, and if this process goes on indefinitely,, it becomes evident that in the course of time the descendants of the original type will become widely unlike «ach other, and will show great variation from primitive forms. Such has been the history of animals and plants. So far as we can learn of that history, it has always been one of divergence from common centers, the process being repeated over and over again in successive ages, until finally there has resulted the great diversity of organisms that people the world of to-day. At the beginning of life in the world there was, apparently, no difference between animals and plants. We have already seen that some organisms so closely resemble both groups that we cannot say whether they are animals or plants. Possibly some such organisms were the first to inhabit .the world. As progress continued, however, the descendants of these original forms of life diverged from each other along two great lines, one of which acquired the habit of living upon the other. The original form of life must have been capable of utilizing the mineral ingredients hi nature, possibly like the green plants of to-day. Whether the original organisms were capable of carrying on photosynthesis we do not know, but hi some way they must have been able to utilize minerals. However that may be, their descendants diverged into two groups, one group acquiring the green coloring matter and the power of utilizing carbon dioxid and sunlight and, by means of chlorophyll, building up starch, thus giving rise to plants. The second group of descendants, losing this power of utilizing minerals, and acquiring the power of feeding upon the materials which were manufactured by the first group, developed into the kingdom of animals. After plants and animals were thus separated and each had developed for a time along its own line, some of the plants lost their chlorophyll and acquired the habit of depending upon other plants for food, thus becoming the Fungi. As the history of the world progressed, each of the two great types thus started continued to repeat the history of divergence. Age after age the descendants continued to separate into different lines, until the modern world was finally produced, with its endless series of different forms, all having been derived from common centers by descent with divergence. ADAPTATION Meaning of Adaptation. — One of the most striking facts of the organic world, resulting from heredity and variation, is the adaptation of animals and plants to their environment. By this term is meant that the parts of each animal and plant are so particularly fitted to the conditions of its life that it seems as if they were intelligently fashioned with this end in view. A few illustrations will make the matter a little clearer. The tree, with its roots extending under ground, with its branches growing into the air and bearing the broadly expanded leaf surface for the purpose of absorbing air, is evidently exactly adapted for its life in the soil and in the air. The roots are mechanically built so that they can push their way through the soil; the stems are rigid enough to support the heavy branches, and the leaves are broad and thin and of exactly the proper shape to absorb the largest amount of air. The wing of a bird is an example of adaptation; for its structure, its shape, the lightness of its bones, its ability to expand its feathers, the delicate manner in which the parts of the feathers are attached to each other, are all admirably adapted to an organ whose function is to support the bird in the air. The bird's feet are a beautiful instance of adaptation, since wading birds, swimming birds, and scratching birds have feet plainly adapted to their peculiar habits of life; Figs. 140 to 143. The white fur of the polar bear is an adaptation to its life habits in the north on the ice sheets; for not only does the heavy hair serve as a warm covering to protect the animal from the cold, but its color at a distance is hardly to be distinguished from the white ice, and thus protects the bear from observation. The marvelous tongue of the ADAPTED FOR SCRATCHING ADAPTED FOR SWIMMING butterfly is adapted for sucking the honey from flowers. The honey in the flower is at the bottom of the long corolla, and unless the butterfly had this long tongue to insert within the corolla and thus reach the honey, it would not be able to utilize this food. Each butterfly is provided with a tongue sufficiently long to obtain the honey from the particular kind of flower upon which it feeds. The marvelous structure of the human hand, with its wonderful mobility, its delicate sensations, its great power of muscle movement, is clearly adapted for use as an organ of prehension, and one might believe, as has been vigorously argued, that it was especially made by an intelligent designer for the conditions of life in which man lives. The principle of adaptation is found everywhere in nature, all animals and plants being more or less adapted to their conditions of life. Indeed, perhaps the most characteristic feature of organisms is that they are adapted to their environment, instead of being purely haphazard in their shape and structure. Inanimate objects, like stones, have no special relation to their environment, and having been produced by blind forces, are not particularly adapted to any purpose. In contrast to this, all animals and all plants show structure and functions which fit them for their environment. We may almost regard this feature of adaptation as the most universal and striking characteristic of life. Origin of Adaptation. — How came organisms to be thus adapted to their environment? The explanation of adaptation which was for a long time regarded as satisfactory, was that each animal was made by an intelligent Creator, and exactly fitted to the environment in which it was placed. This suggestion was satisfactory so long as it was believed that each species was an independent creation. Since, however, the idea of special creation has been replaced by the belief that our present species have been derived from older types by descent, the problem of adaptation to their environment must be given a different solution. If animals have diverged from common centers, it follows that types now inhabiting different localities must have originally come from the same place, and if they were originally adapted to one locality, they could not be especially adapted to the conditions of new localities. Hence their adaptation to a new environment must have been acquired during their growth, and not by an original special creation. The question of how the adaptation was produced, therefore, comes up with redoubled force. More careful study, however, shows that animals are not always exactly adapted to their environment. The old idea that each organism is especially fitted for its environment is not borne out by facts. Of course living animals are always in a measure adapted to the conditions in which they live, for if they were not they would long since have been exterminated. Indeed, the history of animals shows many instances where poorly adapted animals have been crushed out of existence, leaving alive only those adapted to their environment. On the other hand, many instances are known where organisms living in one part of the world to-day are not particularly adapted to their habitat, but are really better adapted to other parts £>f the world if they could only get into new regions. It not infrequently happens that organisms from one country get carried by accident to another, and find the new country far better adapted to their life than their original home. For example, when the European hare was carried to Australia, it found conditions far better adapted to it than those of its original home in Europe, and it multiplied with prodigious rapidity, becoming far more abundant in Australia than ever it was in Europe. The English sparrow, when introduced from England, finding America better adapted to its life than England, multiplied very rapidly, and spread over the country. Our fields in the eastern states are filled with the so-called white daisy (Leucanthemum) . This is a European species which, when introduced into this country, found conditions better adapted to its needs than in its original home and became far more abundant here than in its original home. These three illustrations show that although animals certainly must be adapted to the conditions in which they live or be exterminated, they are not particularly made for those localities, since in many cases they are better fitted for other localities than their own homes. The idea that organisms were especially designed by creation to fit the conditions in which they live is thus disproved. Adaptation the Result of Growth. — The history of organisms shows that adaptation to environment has not come suddenly, but has been the result of slow development, brought about by race divergence and evolution. Adaptation in the life of the individual. — When the individual starts its existence it is simply a fertilized egg. It is a cell, and is not especially adapted to any particular condition of life. In its development the cell divides into many cells, and these cells assume different shapes and relations. As the organism grows, the adaptation to the environment makes its appearance. In plants, the roots soon assume a form which adapts them to the soil, while the leaves become fitted for the air; in animals, some cells adapt themselves to functions of digestion, others to the functions of motion, etc. In other words, in the life of the individual, adaptation is a matter of slow growth and comes step by step as the egg is gradually molding itself, into the form of the adult. Concealed in this fertilized egg are marvelous powers which cause the egg to develop into an adult, and the powers that cause the development of the egg cause also the adaptation of the different parts to the conditions of life. Adaptation in the race. — There is no doubt that a similar history of growth has brought about the adaptation of the race to environment. Probably the earliest type of the plant was a single cell, adapted to life in the water but not in the soil. As the ages passed on and plants reached the land, an adaptation to this new environment slowly developed. The structures which we find in animals and plants to-day, which adapt them to their environment, were not of sudden origin in any case, but were the result of a gradual change of the older forms into newer types, more closely adapted to the new conditions of life. development of the spinal column of the vertebrates- during the geological ages, which is disclosed by the fossils in the rocks. When the vertebrates first appeared, apparently they had no bones, but in their backs was a rather stiff rod which gave them rigidity, this being represented by the rod in the embryo which we have already learned to speak of as the notochord (see page 286) . Following along through the various strata of rocks, which represent a progressive development of vertebrates, we find that this rod in time became broken up into short sections, a condition which adapted its possessor very much better to an active life in the water. The short sections, which became the vertebrae, enabled a lateral flexing motion of the body which could not be brought about so readily if there were only a stiff supporting rod in the back. This broken series of bones, forming the vertebral column, thus adapted the animal to its rapid motion in the water. Later, when the vertebrates emerged from the water and assumed a life on the land, the type of vertebras adapted to life in the water was no longer fitted for the condition in which the animal now lived. The vertebrae were still retained, but they acquired new connections with each other, a greater solidity and a greater rigidity, so that the spinal column could now support the body in the air. Further development of the land animals into the birds was characterized by a further change in the form of the vertebrae, which adapted the animal to life in the air, and, moreover, the vertebrae were changed in another fashion in the mammals which lived on the land. In all of these series of changes, from the original unbroken rod of the back in paleozoic times, to the complicated spinal column of the mammal, we see a successive series of adaptations. The study of fossils has made it possible to trace this series of changes in detail, and our paleontologists have quite accurately pictured for us the succession of changes that has produced this long series of race variations, bringing about an adaptation of the race, first to one condition of life and then to another, and finally ending in the excellently adapted internal skeleton which the higher vertebrates possess to-day. All of this can be followed out in the study of fossils, and it represents only one of the many series of evolutionary changes which have occurred in the history of animals, adapting the race little by little to new conditions, or better adapting them to older ones. Forces Producing Race Adaptation. — While biology has not yet reached a point where it considers itself capable of explainingall of the marvelous phenomena of adaptation, some of the laws that have been concerned in the production of the phenomena are fairly well understood. A primary one seems to be the law of natural selection, first exploited by Charles Darwin. This law and its action will be considered on a later page. THE THEORY OF EVOLUTION The divergence of animals and plants from common centers to produce the diversified world of to-day has been generally known under the phrase, the theory of evolution, or the theory of organic descent. The term "e volution" has a very much wider application than that which has just been given to it, since in its philosophical import it involves much more than the problem of the origin of species of animals and plants. The general theory of evolution includes the conception of the orderly development of the whole universe, by a system of natural law and force, and assumes that the origin of the world from the original nebulous mass has been, from the beginning, due to the unfolding of natural law. With the philosophical aspects of the theory we are not here concerned; but the phase of the theory that concerns the origin of modern animals and plants is one of the fundamental factors of modern biological thought. Indeed, it may be stated that modern biology did not have any real existence until, under the influence of the writings of Charles Darwin, the conception of the origin of species from common types began to be studied. of organisms to their environment has been a matter of growth, is the result of the thought of the last half-century. Previous to the middle of the last century it had been assumed that organisms transmitted their characters so accurately to their offspring that they had continued from the beginning unchanged, and that species were immutable. The immutability of species (Lat. im = not + mutabilis = changing) had been assumed as the foundation stone of biological science, and all conceptions of nature had been based upon the idea that organisms breed strictly according to their type, without change, other than slight fluctuations back and forth from a center, and without permanent modification. The conception which we have assumed above — that not only are all organisms constantly undergoing individual variations, but that races are going through a gradual series of permanent changes, resulting in the appearance of new forms with successive ages — was quite revolutionary in thought. The belief that species were not immutable, but were constantly being transformed into new species by the ordinary processes of descent, changed the whole aspect of our attitude toward nature. During the fifty years after this conception was presented to the world for discussion, it was subjected to most hostile criticism and most bitter dispute. The objections have now, however, mainly disappeared, and it has become to-day one of the accepted doctrines of science that species are constantly undergoing changes, and that our present species have descended from older ones and will in turn develop into others. To understand and appreciate this modern conception, it is necessary to survey briefly the development of the idea and the fundamental facts that lie underneath it. In this review we will make reference only to that phase of the great theory of evolution that has to do with the origin of modern species, or to organic evolution, as it is commonly termed. Early Views. — We can trace a beginning of the idea of evolution back to the scientists and philosophers before Christ. Aristotle, nearly four centuries before Christ, recognized in a vague way the idea of a gradual succession of higher and higher forms of existence; and several other early philosophers speculated concerning the origin of living things upon the earth according to general processes of development. But these earlier ideas were soon lost sight of and it was not until the seventeenth century that any more modern ideas of the development of animals from each other were advanced. During all of these centuries, and indeed until about the middle of the nineteenth century, so far as the subject was thought of at all, the view generally accepted was that each different kind of animal and plant was an independent creation. This view crystallized into the special creation theory in the writings of John Ray in 1725, and became the generally accepted view of all scientists. During the seventeenth and eighteenth centuries, however, several philosophers expressed, in their writings, ideas approximating the belief that living things do not remain forever constant, but are ever going through the series of changes that we have already described as race divergence. Among those whose writings tended in this direction may be mentioned Kant, Goethe, Leibnitz, Erasmus Darwin, and others. With the beginning of the nineteenth century these conceptions began to take a more definite shape. Lamarck. — Lamarck was a French naturalist, living in about the beginning of the nineteenth century, and was well versed in botany and zoology. He formulated a clearly defined doctrine of descent, and was the first of the modern scientists who had any conception of the theory of evolution. Lamarck believed that the fossils found in the rocks were the ancestors of animals living to-day, and that the organisms of the present world have been derived by descent from those that lived in previous years. The changes that had taken place in their structure he believed to have been slow and gradual, but continuous, and produced by a variety of causes which he specified, and which have received the name of Lamarckian factors. The chief of these causes were the following: — selves. 3. Use and disuse. — It is a well-known fact that the use of any organ causes it to increase, and the failure to use it causes it to decrease in size and in efficiency. Lamarck supposed that the arms of birds became wings through continued use in this direction, and that the hind legs of snakes were lost because they were not used. This has been the most universally recognized of the Lamarckian factors. 4. The transmission of these acquired characters to posterity. Lamarck assumed, as everyone else assumed in his day, that any characteristics possessed by an animal or a plant might be transferred to its offspring. Hence any of the changes produced by the environment, by new physical needs, or by use and disuse, would be transmitted to the offspring, and, therefore, the next generation would have the body modified by the habit and environment in which the first generation lived. This would result in a constant modification of organisms, producing evolution. There were certain other factors in Lamarck's conception which, though really part of the original theory, are not commonly included under the term of Lamarckian factors. One of these was cross breeding, i. e., breeding together of individuals of different varieties, or perhaps even of different species, the result being an offspring different from either parent. A second was isolation, a suggestion that certain individuals became separated from the rest, and they and their offspring, being obliged to breed together, produced types in an isolated locality, which developed along lines different from those taken by other members of the same species in other parts of the world. assumed that diversities produced in individuals as the result of the action of the environment, or of their own habits, i. e., acquired variations, are transmitted to subsequent generations, and serve as the basis of the changes which produce race variations and evolution. Our study of heredity has shown that such variations, according to our present knowledge, are almost certainly not transmitted to subsequent generations. It is evident that the very foundation of the Lamarckian theory cannot stand, if the modern conception of heredity is accepted. Lamarck's views were not accepted in his day. This was partly because the great French naturalist, Cuvier, one of the greatest naturalists that ever lived, opposed them strongly; and partly because the scientific world was not at that time ready to accept any such natural explanation of the origin of organisms as that suggested by Lamarck. They were, therefore, practically forgotten for a period of fifty years, during which time the idea that organisms had appeared by the process of descent had practically no followers, special creation of each species to fit its environment being the generally accepted view. A new era of thought was inaugurated in the middle of the nineteenth century by Chalmers, Spencer, and especially in 1859, by Charles Darwin. Charles Darwin. — Charles Darwin was the grandson of Erasmus Darwin, already mentioned. In 1859 he published a book, the result of twenty years' work, entitled "The Origin of Species," which produced a revolution in thought, not only in science but also in philosophy. Darwin accepted the idea of the origin of modern organisms from earlier ones by a process of direct descent, recognizing that divergence of type from common centers has been the law of historical development of animals and plants. To this extent, therefore, Darwin followed Lamarck and the early speculators concerning the origin of animals. Darwin's method of explaining this descent was totally different from that of Lamarck, and much more in accordance with facts that could be demonstrated. According to 1. Overproduction. — All animals and plants tend to multiply more rapidly than it is possible for them to continue to exist. More offspring are produced by even the slowest breeding animals and plants than can possibly find sustenance in the world. 2. Struggle for existence. — As the result of overproduction, the individuals that are born are engaged in a constant struggle with each other for the opportunity to live. This struggle is sometimes an active and sometimes a passive one; and sometimes it is a struggle with each other for food. It is a struggle in which only the victors remain alive, the vanquished being exterminated without living long enough to leave offspring. 3. Variation, or diversity. — All animals and plants show a large amount of diversity among themselves, and, as a result, some must be better fitted for the struggle for life than others. 4. Natural selection, or the survival of the fittest. — It is a logical result of the struggle for existence that only those individuals best fitted for the struggle will be the ones, in the long run, to win in the contest. Hence the "fittest" in the long run will survive, while those less fitted to exist will be exterminated in the merciless struggle for existence. 5. Heredity. — By the law of heredity, individuals transmit to their offspring their own characters. Hence if one individual survives the struggle for existence by virtue of some special characteristic, it will transmit this characteristic to its offspring. The offspring will inherit it, and in the course of a few generations the only individuals left alive will be those that have developed the favorable characteristic in question, while those that did not develop it will be exterminated by the law of natural selection. As the result of these five factors working together, Darwin supposed that there would be a constant accumulation of favorable characters, each generation being to a slight extent an advance over the last. The struggle for existence and the survival of the fittest are repeated generation after generation, and in each successive generation the only members to survive will be those with qualities that make them better able to contend in the struggle for existence than their rivals. Hence every individual character which gives its possessor any slight advantage over its rival will be sufficient to enable its possessors to survive the struggle for existence, by bringing about the extermination of the less fortunate individuals that did not have the favorable character in question. This character will be transmitted to subsequent generations, when the struggle will be repeated again, and once more the best characters of the next generation will be selected. As this goes on without cessation age after age, there will be a constant accumulation of favorable characters, and thus the race will in general constantly advance. Natural Selection and Adaptation. — This law of natural selection is especially well fitted to explain the marvelous adaptations of organisms to their environment. Since the different members of any species of animals or plants are not alike, it will follow that at any period in the history of a race, some individuals will be more closely adapted to their environment than others. Since there is always an overproduction of individuals, so that many more are born than can live, it will follow that the individuals best adapted to their environment will be the ones that will survive, while those less adapted to the conditions of life will be the ones to be exterminated in the struggle for existence. Hence it will follow that at the close of any generation the individuals left alive will be those that have the most favorable adaptation to environment. These will necessarily be the parents of the following generations, and, by the law of heredity, the next generation will inherit the characteristics of these parents and will be, on the average, a little better adapted to the environment than the last generation. If this process is repeated generation after generation, it will follow that each generation will be slightly better adapted than the last. By an accumulation of the improvements which thus appear accidentally, there will be developed, as the generations pass, a closer and closer adaptation to conditions. The final result is a better adaptation to conditions, and a gradual change of type and production of new species. Acquired and Congenital Characters Affecting Natural Selection. — In the form stated above, and as at first conceived by Darwin, the characters which are chosen by natural selection, and upon which the advance of the race is based, might be either acquired characters, such as those upon which Lamarck based his theory, or they might be congenital characters, which are in the germ plasm and essentially due to variation in the hereditary substance. Darwin did not sharply separate these two types of variation, although he recognized them both. Darwin thought that the advancement of type was produced primarily by the natural selection of such characters as were born with the individual, i. e., congenital characters. He also believed that, to a certain extent, acquired characters, which were produced in the animal either by the direct effect of the environment or by use or disuse, could be transmitted and might thus affect posterity and have an influence in changing the type. Darwin did not believe, as did Lamarck, that these acquired characters were the primary factors in producing divergence of type, but thought they might be secondary ones, the primary factor being the selection of most favorable congenital variations. Weismann. — The discussion of Darwin's theories continued vigorously for a quarter of a century, until his views of descent were quite generally accepted, although with various opinions as to the efficiency of his law of natural selection. In 1884 appeared the essay L* Weismann "On Heredity," which put a totally new aspect on the whole problem. His theory of heredity, already described, was so simple, and so readily obtained confirmation by direct observation, that it soon acquired almost universal acceptance. With the acceptance of Weismann's theory, it was no longer possible to look upon acquired characters as transmitted to posterity. As a result, the Lamarckian factors were of necessity thrown overboard, since they all involved the inheritance of acquired characters. It was no longer possible to believe that the direct effect of the environment upon the individual, or the effect of the disuse of organs, could have any influence upon posterity; and as rapidly as Weismann's theory of heredity received acceptance the so-called Lamarckian factors were discarded, until to-day they are not generally regarded as factors in producing race variation. The adherents of Weismann have thought that the only possible factor left to produce evolution was the natural selection of the congenital variation. Congenital variations, since they are due to variations in the germ plasm, will be transmitted; and the natural selection of these congenital variations will remain as the great factor in the development of type. Indeed, the followers of Weismann took this extreme view and held, and still hold, that the only factor which has produced race evolution has been the natural selection of those characters which start as variations in the germ substance. But the dispute between the followers of Lamarck's older views and Weismann's new views has never yet been positively settled. Some naturalists accept Weismann's views in toto; others have not regarded them as sufficiently well demonstrated; while quite a number of prominent biologists, including Spencer, Packard, Cope, and others, have held to a modern form of Lamarck's views, believing that in some way, and under some circumstances, acquired characters might have influence upon the offspring and therefore might direct the line of race divergence. The question has not been definitely settled; but at the present time the balance of evidence seems to be against believing that acquired characters are transmitted, and therefore against the retention of any of the so-called Lamarckian factors, that are based upon the direct action of the environment upon the individual. The Mutation Theory. — One of the essential factors of the Darwinian theory was that the change of species was produced by the selection of minute diversities, such as the slight differences found among animals and plants of the same species. It was argued by Darwin that in the struggle for existence, when the majority must be exterminated that the few may live, even the slightest differences in structure, shape, body, color, or habits would be sufficient to determine the question of life or death. If these slight differences could accumulate, generation after generation, they would in time become great; and thus, according to Darwin, the great differences between type were produced by the accumulation and heaping up of minute variations. To many of the more recent students of this subject it has not seemed plausible that such minute differences could accomplish all that Darwin claimed for them. Many objections to Darwin's ideas on this line have been expressed, and have finally found voice in a more recent conception of the conditions which have produced the evolution of the living world. This new idea is the mutation theory (Lat. mutare = to change), and is commonly associated with the Dutch naturalist, DeVries, although a number of others have shared in its origin and development. DeVries based his views upon observations made in a field of primroses, where he kept thousands of individuals under observation. As the result of these observations, he came to the conclusion that new types of plants are appearing constantly in nature; but that they do not arise, as Darwin had supposed, by the accumulation of little changes one generation after another, but suddenly, and, as a rule, in single steps. In his field of primroses, growing side by side, he found several distinct types, absolutely different from each other and with no intermediate steps between them. They came, not as the result of the accumulation of little steps, but suddenly, in a single generation. Moreover, by isolating and experimenting with them, he found that the new characters, which had thus appeared, bred true, i. e.y remained fixed m the race. From this series of observations, extended in other directions by many other observers, has been developed the theory of mutation. This theory is, in essence, that new characters do not, as a rule, appear simply as slight diversities found between different individuals of the same species, but as characters of considerable extent at a single birth. New features of the race are thus sudden in their origin instead of gradual, as had been supposed by Darwin and also by Lamarck. According to this theory there are two types of variation among organisms: 1. Individual variations, spoken of above as the diversities which Mutations, which probably start with the germ plasm; Fig. 144. These variations may be large or small, but whenever they appear they are at once fixed in the race. Inasmuch as they are part of the germ substance, they will be handed on to the next generation and remain, therefore, as a permanent inheritance of the race. According to the mutation theory, these sudden large changes have brought about the race divergence. The theory of mutation, therefore, abandons Darwin's idea of the accumulation of the minute diversities, and replaces it with the idea that the steps in evolution may be larger and may be taken suddenly. It is, of course, evident that this new conception of mutation is perfectly consistent with Weismann's view of heredity. BEETLE LEPTINOTARSA A and C are mutants from the original form B. The actual differences are greater than appears in these figures because of great differences in color. (Tower.) Mendel's Law. — Accompanying the development of the theory of mutation, there has been brought prominently to view a somewhat new view of the laws of heredity, perfectly consistent with Weismann's theory, but explaining its method of action. Darwin in his discussion assumed that the offspring of two parents, since it could not be like both, would, in general, be halfway between the two. Even the slightest familiarity with the laws of heredity is enough to show that organisms inherit from both parents, and it has generally been assumed that they inherit, or may inherit, equally from both. It is, however, manifestly untrue that the offspring is always midway between its father and mother, inheriting equally characters from each. The laws of heredity are much more complex than this, for it frequently appears that an organism inherits mostly from one parent, the characteristics of the other hardly- reappearing in the offspring. An attempt to bring some of these facts into a general law has resulted in what is called Mendel's law of heredity. Mendel published the result of his work originally in 1866, but it attracted no special attention for nearly forty years, when it was revived by modern students in 1900. Since that time it has been subjected to extensive experiment, and has produced results of very great practical value in controlling and directing breeding experiments with animals and plants. Mendel's law is somewhat complex and difficult to understand, but the essential features of it -are as follows : — Unit characters. — It is an assumption of Mendel's law that, in many cases at least, different characters of animals are unit characters. By this term is meant that those characteristics are handed to the offspring as single units, which are inherited by the offspring in toto or not inherited at all. They cannot be halved or reduced in total characteristics. In other words, if the offspring inherits one of these unit characters, it inherits it in full. Even though the offspring should come from two parents, one of whom possessed the character in question, while the other did not, the offspring would either inherit it as a whole or not at all. For example, two varieties of peas are known, one of which has short pods and the other long pods. If they are crossed the offspring are either short-podded or long-podded, but not midway between the two. Very many other characters have been tested out experimentally and found in the same way to be inherited as unit characters. Dominant and recessive characters. — Mendel's law further points out that some of these unit characters are much more likely to reappear in the offspring than others. It frequently happens that of two opposite characters, one is much more likely to appear in the next generation than the other. Those that are most likely to reappear are called, in this terminology, dominant (Lat. dominari = to rule), while other characters that are more likely to disappear in the first generation, are called recessive (Lat. recessus = receding). These recessive characters, even though they do not appear in the first generation of offspring, are not necessarily lost. The offspring may contain within its body the germs of these characters, but they may remain dormant, not appearing at all in the first generation. In subsequent generations these recessive characters may reappear; thus recessive characters, which are present in one generation, may disappear in a following generation, to reappear subsequently in the later generations. Law of inheritance. — The specially valuable contribution of Mendelism is the formulation of a law in accordance with which these dominant and recessive characters reappear in subsequent generations. That law is briefly as follows : When we cross with each other two individuals, one of which has a dominant character, while the other has its opposite as a recessive character, all of the offspring in the first generation show the dominant characteristics. But although showing only the dominant characters they actually contain a mixture of dominant and recessive characters. This is shown by the fact that if these individuals now are bred together, in the next generation, which we will call the second generation, only three-fourths of the off- spring will show the dominant character, while one-fourth will show the recessive character. If now the individuals showing this recessive character are bred with each other, all their offspring will show the recessive character, the dominant character having totally disappeared from them, never to occur again in any subsequent generation. This race is then a pure recessive type, from which all of the dominant characteristics have been eliminated. All of the other three-fourths of the second generation show the dominant character only. But tests, similar to the above, prove that only one of these is purely dominant. The other two-fourths, although in them the dominant character only is evident, are really mixed, containing both dominant and recessive characters. This is shown by the fact that if they are crossed, three-fourths of their offspring will again show the dominant character and one-fourth will show the recessive character. This process may then be repeated indefinitely. An illustration may make this clearer. Among mice the color gray is dominant, while the color white is recessive. If white and gray mice are bred together, the first generation of offspring will be all gray. If these gray animals are now bred together, in the second generation three-fourths of the offspring will be gray but one fourth will be white. If these white animals are bred together, their offspring will all be white and will continue to breed white offspring indefinitely, no gray mice ever subsequently appearing in their progeny. If the other three-fourths, which are gray, are bred together, one of the three-fourths will continue indefinitely to produce gray offspring, no white ones appearing. In these the white characteristic has been eliminated entirely, and they form a pure gray race. But the other two-fourths, when bred together, prove to contain both white and gray characters, and among their offspring one-fourth will show the white fur and the other three-fourths the gray fur. If again tested in the same way, the white animals will be found to produce pure races of white with no mixture of gray fur; one of the other fourths will be found to be pure gray races with no mixture of white, and the other two-fourths will again prove to be a mixed race containing both white and gray characters. This process may then go on indefinitely. The further details of this law are too complicated to be followed out in this place, but from the law it is possible to calculate approximately how many of the offspring at each generation will show recessive, and how many dominant characters. This law has been of great value in directing breeding experiments, and breeders who are trying to produce new varieties of animals and plants find the law extremely useful in controlling their exI HT iments toward definite ends. Mendel's law has thus shown that the inheritance by the offspring of the characters of the parents is not a pure matter of chance, but is controlled by definite laws. While we do not yet fully understand these laws, the fact that some of them have been discovered gives promise that we may, in time, be able to control the process of inheritance far more accurately than hitherto. It is not believed by those who have worked on Mendel's law that all characteristics of organisms are thus unit characters and are transmitted in toto or not at all. Some characters appear to blend, as for example the cross between the white race and the negro, the offspring of such crossing being neither white nor black but mulattoes, a mixture midway between the parents. Hence the color of the human skin is probably not like the white and gray color in mice, a character transmitted by the law of Mendel. This law of Mendel has, however, been a great contribution to science in showing that large numbers of characters or organisms are unit characters, and are transmitted according to definite laws that may be clearly formulated. We may say, in concluding the general subject, that modern biological science recognizes the principle that race divergence has been the law of life, and that the evolution of modern types from earlier ones by descent has been the method by which the present world was produced. Further, the laws formulated by Darwin, DeVries, and Mendel, together with Weismann's theory of heredity, all fit together to explain the method of this evolution. New variations have appeared suddenly, at least in many cases, as germ variations (mutations) , and then have been transmitted to the offspring as unit characters by Mendel's law, some of the offspring receiving the new characters, while others do not; but if inherited they are inherited as unit characters. Next, the law of natural selection comes in and selects those individuals which have received useful mutations. Selection then "fixes them" in the race by eliminating individuals with characters less useful than those possessed by the survivors. As a result of all these factors working together the race advances. CLASSIFICATION AND DISTRIBUTION EVEN the slightest familiarity with organisms will disclose striking similarities between some forms and great differences between others. The frog is clearly quite like the lizard and much like other vertebrates, but very unlike the earthworm. These points of likeness are the basis upon which organisms are classified. u, ulna. Homology. — The likeness between organisms is of two general types. The first is likeness in structure, which is called homology (Gr. homos = like + logos = ratio) . It is frequently found that animals which appear quite unlike are really built upon the same plan of structure, differing only in the manner that the plan is carried out. For example, the frog possesses a spinal column made of vertebrae, and two pairs of legs attached to the body by girdles, each containing a certain number of bones. The rabbit (Fig. 145) has a skeleton based upon the same type. It also possesses a spinal column made of vertebra, with two pairs of appendages attached by girdles to the axis of the body; and each appendage is made up of bones which can be compared, bone by bone, with those in the appendages of the frog. If Figure 145 is compared with Figure 88, this similarity can be seen and followed out in very close detail, nearly all of the bones of the frog being represented in the skeleton of the rabbit. This similarity is found in spite of the fact that the two animals are so unlike in general appearance and in habits. One lives in the water and uses its legs for swimming and hopping; the other lives on the animals. Although the hand of man is used for a totally different purpose from that of the fore legs of the horse, the ox, or any of the other animals represented, it is evident that they are built upon the same plan of structure. In each there are a radius and ulna, and a series of wrist and finger bones. There are differences, it is true: while The skeleton of the hand of man, C; and the fore feet of a horse, A; a rhinoceros, B; a pig, D; and an ox,E. r, radius ; u, ulna. The other bones are not named but may be easily compared. tory through fossils it is found that the ancestors of the horse had at first five fingers, with a type of hand similar to that of man; later they had three and easy to trace in the eye of the frog the same parts that are present in the human eye. It is perfectly clear that these two organs are based upon the same plan and are identically planned structures. Such similarities in structure are not by any means confined to animals with a bony skeleton, but may be found among all groups of animals. Figure 149 represents a worm, which, by comparison with the figures of the earthworm in Chapter VIII, shows a similar structure in spite of differences in detail. The earthworm bears at first sight little resemblance to the worm shown in Figure 149, the latter having external tentacles and gills, neither of which is found in the earthworm. But it will be seen that both are made up of a series of similar segments, and that in general shape they are the same. If their internal anatomy is compared, both are found to have a similar alimen- be homologous. Analogy. — A second type of likeness is. similarity in function, irrespective of structure. It not infrequently happens that different animals develop organs of similar functions but of totally different structure. In this case they are said to be analogous (Gr. ana = according to + logos = ratio) but not homologous. For example, the butterfly and the bird have both developed wings for flying, and their wings are hence analogous. They are of similar shape and are used mucb in the same way; but the wing of the bird is made of bones, muscles, nerves, and feathers, while the wing of the butterfly has none of these parts, being simply an outgrowth of the skin containing air tubes. It is not homologous with the bird's wing, in spite of similarity in shape and function. The wing of the bird is, however, both analogous and homologous with the wing of the bat, since both are used for similar purposes and both are made of similar bones and muscles, nerves and blood vessels. As another example of analogous organs, may be mentioned the teeth in the mouth of vertebrates and the peculiar teeth found inside the stomach of the lobster. These organs are both used for grinding food; but they are not homologous organs, since their structure is so different. The teeth are bony organs arising from the bones of the skull, which are themselves developed from the mesoderm of the embryo; the teeth of the lobster are of horny texture, and are developed from the ectoderm of the embryo which is folded inward to line the stomach. Numerous other examples of analogous organs might be given, for it frequently happens that different animals use for the same purpose organs that have quite a different origin and structure. Explanation of Homology and Analogy. — Analogous organs sometimes show much similarity, as in the shape of the wings of the bird and butterfly, and sometimes very little. When they do show a likeness it is explained by the fact that similar necessities of life have forced the development of similar structure. For example, both the vertebrates and the lobster are obliged to masticate their food, and both have consequently developed hard cutting and grinding surfaces for the purpose. There is, therefore, some similarity in the form of the organs; but there is no necessity for similarity in structure, and in the two cases different parts of the body have been utilized for the purpose. The likeness between homologous organs, however, requires a very different explanation, because here we find a similarity in structure in spite of differences in function. We cannot explain the similarity in structure by any similarity of conditions. Although the wing of the bird and the arm of man are adapted to wholly different functions and have developed different shapes and motions, they are, in spite of this difference, formed upon the same plan, with an identical structure. The explanation must be something more fundamental than mere similarity in use. Naturalists to-day account for likeness in homologous organs by the theory of descent, saying that two animals with homologous organs owe their likeness to the fact that they have descended from a common ancestor possessing such an organ. The bird, the dog, and the monkey show homology in the wing, fore leg, and arm, because they have descended from a common ancestor, whose fore appendage possessed a certain series of bones and muscles, and, therefore, all its descendants have, by inheritance, retained these same bones and muscles. The differences between the members in question have been brought about by the fact that they were used for different purposes, and thus were slowly modified in shape, although they still retained a fundamental likeness in structure. Individuals. — As we look upon nature to-day, we find only individual organisms, each isolated from all others, and allied only with its parents. But the most superficial examination shows that some individuals have resemblances to each other, while others are very unlike; and it is evident that organisms can be arranged in groups showing more or less likeness to one another. Such a grouping is called classification. The general plan of such classification into groups is as follows: — Species. — When we find a large number of individuals resembling one another so closely as to be practically identical, we speak of them as belonging to a single species. For example, the common dandelion, which is widely distributed over the world, is made up of countless numbers of individuals; but they are essentially alike, in root, in stem, in leaf, in flower. To give a definition of just what is meant by species is impossible, since no one knows just what is meant, and the word perhaps does not always have the same meaning. That the individuals of a species are not always exactly alike is evident from facts already mentioned concerning the great variations among different pigeons and dogs. Such great variations as those pre- rule the members of the same species are closely alike. Just what biologists mean by species, and just what line they would draw to separate two species from each other, cannot be stated. It is quite impossible to say how unlike two animals must be to constitute two species, since sometimes, as with pigeons, members of the same species may be very unlike, while in other cases, as with sparrows, animals belonging to different species are very closely similar. It has been quite common to regard all animals that can breed together and produce fertile offspring, as belonging to the same species. But this is not an accurate definition of the term, for there are many animals, so different from each other that they certainly deserve to be ranked as different species, but which can breed together. Nor can we get any idea as to the meaning of the term "species" by studying the number of similar individuals. Some species are composed of an immense number of individuals, as in the case of the dandelion; while other species comprise very few animals, sometimes only one or two having been found. Sometimes, too, the organisms belonging to the same species show a number of sub-groups, and the biologist calls them sub-species, or varieties. All of these facts show that no naturalist can at the present time exactly define the term "species," or state definitely how species may be separated from each other. When we recognize that new types are constantly arising from old ones by the process of divergence, it will be seen that we could not always expect to draw sharp lines separating the new and the old types that have arisen from a common center. But although naturalists are not able to define the term accurately, or separate the species strictly from each other, species are always recognized and form the starting point for classification. Genera. — A little study shows at once that some species have a much greater resemblance to each other than they do to others. For example, naturalists recognize the domestic cat as constituting one species, and the wild cat as a second. But it is quite clear that the wild cat and domestic cat show greater resemblances to each other than they do to tigers, dogs, or wolves. Moreover, it is evident to anyone in the slightest degree familiar with animals, that lions, tigers, leopards, wild cats, and domestic cats, although unlike each other, and recognized by naturalists as belonging to different species, have many points of resemblance to each other. They have the same general stealthy habits, the same kind of toes and feet, and they are much more closely allied to each other than any one of them is allied to the dog or the wolf. Naturalists, therefore, group all of these species together under one group which they call a genus (pi. genera). In naming any species, two names are commonly used, the first of which is the name of the genus, the second that of the species. For example, Felis is the name given to the whole genus of cats. Felis domestica is the domestic cat; Felis leo is the lion; Felis bengalis, the bengal tiger; Felis canadensis, the Canadian lynx, etc. So, too, Viola is the genus name of all the violets; Viola blanda, of the white violet; Viola cucullata, of the common blue violet, etc. If the species should happen to have more than one variety or sub-species, a third name may sometimes be added to indicate the particular variety of the species. As a rule, however, two names only are used. Families. — Extending observation a little farther, it becomes evident that many genera show close resemblances which mark them off distinctly from other animals. As a result, naturalists group genera together into a larger group, which they call a family. A family sometimes may contain only a single genus; it may contain two or three or a large number of genera. Orders. — In the same way, families are grouped together to form larger groups, which are called orders. For example, the various cats already considered have certain points in common with the dogs, wolves, bears, seals, and walruses. In all of these cases the teeth are especially adapted for cutting flesh, and the animals are flesh eaters. There are very many genera among them, and a number of different families; but all agree in the living upon flesh, and all show certain points of likeness in the structure of the feet and the skeleton, which place them in a group by themselves, distinct from animals that live upon vegetable foods. All of these flesh-eating animals are, therefore, grouped together into an order called the Carnivora. Classes. — In a similar way, different orders can be arranged in still larger groups. For example, although there are many points of difference between the carnivorous cat, the herbivorous buffalo, the gnawing rabbit, the flying bat, and the gigantic marine whale, still they all agree in one fundamental character. In all of these orders the females have mammary glands and nourish their young by means of milk, a characteristic which is totally lacking in fishes, reptiles, and birds. It is evident, therefore, that all of these milk-producing animals may properly be classed together under one head. Such a group we then know as a class; in this particular case we name them the Mammalia. Phyla. — Extending our observations still farther, we find that all of the animals mentioned, together with fishes, reptiles, amphibia, and birds-, resemble each other in having bones, which none of the rest of the animal kingdom possesses. The insects, clams, etc., never have bones, but have other characteristics of their own. It is evident, therefore, that all animals possessing bones may be grouped together as distinct from other types. This produces a group that we know as a phylum or subkingdom. In this particular case we name the phylum the Vertebrata. Kingdoms. — Now if we sweep our glance over the whole organic world, we find that it is divided into two groups, the animals and the plants. These large groups we call the animal kingdom and the vegetable kingdom. Thus it is seen that the whole organic world is divided into kingdoms, phyla, classes, orders, families, genera, and species. Occasionally we recognize intermediate groups; for instance, between the family and the genera there are sometimes recognized what we call sub-families, between the classes and the orders we find sub-classes, etc. THE SIGNIFICANCE OF CLASSIFICATION Why should there be a classification? — As soon as we recognize the principle of divergence from type it becomes evident that the classification of animals has a meaning. < 'l:i>sification means history, and if we could get a perfect classification we should have pictured the history of organisms. The first step in the development of the organisms of the world was the divergence of animals and plants from one another, thus forming the two kingdoms of plants and animals. Then the process was repeated in each kingdom, where there appeared a still further divergence, a number of different lines of descent starting from common centers, giving rise to the various sub-kingdoms. Again each of these broke up into other lines of descent, and the smaller groups thus made their appearance. Thus types continued breaking up and branching out in various directions, giving rise to a classification which may be compared to a tree, the trunk being the original type of organisms, the various large branches representing the first lines of divergence from the original stock, while the numerous subordinate branches represent the successive types that appeared, by the same general law. The minute twigs at the end of the branches are the species of to-day, and they are aH connected by this line of descent with the original trunk. The classification of animals is the attempt to reconstruct this treelike arrangement of organisms according to their historical relationship. The members of the same species are supposed to have had a common ancestor in a fairly recent period; the different species of the same genus had a common ancestor a little farther back in history; the different genera of the same family had a still earlier common ancestor; the families of the same order had their connecting point farther back still, and so on through the whole series, until we get back to the common starting point, or the common center from which all animals and plants diverge. Classification is thus an expression of history. The following is an outline of the classification of animals and plants. The classification accepted by science is ever undergoing changes, as a more complete knowledge of relations is obtained, and the classification accepted to-day is different in many respects from that adopted a generation ago. In turn, the classification used to-day will doubtless be modified by future study, until it becomes practically perfect. But even though we recognize that it is not yet perfect, it is quite necessary to have such a classification in order to understand the living world. It must not be inferred that our present classification represents an accurate history of organisms. The classification that biologists are aiming at is a genetic one, i. e., one that represents actual relationships, and to a considerable extent the classification outlined below does represent such relationships. But the difficulties of determining the actual history of organisms have been so great as to seem in some respects almost insurmountable. The classification of organisms given to-day represents, therefore, only an attempt to express genetic relationships, and is recognized as being only in part successful. including unicellular forms, pond weeds, seaweeds, etc. Class I. Diatomacece: the diatoms (Fig. 68 A). Class II. Cyanophycece: the blue-green algae (Fig. 68 C). Class III. Chlorophycece: the green algae (Fig. 30). Class IV. Phceophycece: the brown algae. Class V. Rhodophycece: the red algae. Phylum III. PTERIDOPHYTA: the ferns and their allies. Class I. Filicales: the true ferns (Fig. 124). Class II. Equisetales: the horse-tails. Class III. Lycopodiales: the club mosses. oysters, mussels. Class II. Gasteropoda: univalves, snails. Class III. Amphineura: many-valved: chiton. Class IV. Cephalopoda: with long arms: squids, cuttle DISTRIBUTION OF ANIMALS IN SPACE AND TIME We have already seen that while organisms are always adapted to the locality in which they live, they are frequently even better fitted for other localities, and their presence in any part of the world must be due to other factors besides fitness. The distribution of organisms on the earth's surface is controlled by three fairly well-known laws:— 1 . The members of a species usually occupy a continuous territory. We do not find some members of a species in one locality and others in a distant region, without finding them also in intermediate territory. There are some exceptions to this law, but in the vast majority of instances each species occupies a continuous territory around a center of origin. The territory occupied will depend upon many factors of climate, for of course the habitat must be properly fitted to furnish the organism with food, water, and a proper temperature. 2. All animals and plants can multiply with a rapidity sufficient to give them, in a comparatively short time, enough offspring to cover the face of the earth. The rate of multiplication of different organisms varies very greatly. The codfish may produce 8,000,000 eggs per year, while the elephant produces only a single offspring in two years, and usually not so frequently as that. Among the lower animals and plants, the rate of reproduction is sometimes even greater than the higher number given above. But even the slow rate of the elephant is sufficient, if the multiplication were unchecked, to enable the species to fill the world in a few years. The numerous offspring are always endeavoring to find room for themselves, and food to eat. For this purpose they distribute themselves as widely as possible. 3. All organisms distribute themselves from the centers, where their reproduction is rapid. All organisms, even those that seem stationary, have some method of dispersing themselves over the earth. The means of dispersal are chiefly the following: 1. By independent migration. This is true of almost all animals, but it is not true of plants, which, as a rule, have no independent power of motion. 2. By winds. Many plants produce seeds or spores which can be blown for long distances by the wind, until they land in a favorable locality, where they can develop into new plants. This dispersal by the wind is not so common among animals, although some of the lighter animals which fly, like the insects and bats, may be blown for long distances by the wind. 3. By water currents. The ocean currents and fresh-water streams carry many animals and plants long distances. The Gulf Stream carries living organisms across the Atlantic Ocean, and a river flowing through a country may distribute seeds for hundreds, and even thousands, of miles. 4. Incidental means. There are various incidental methods by which seeds or eggs, or even living animals, may be distributed. Wood-boring insects may be carried on drifting logs; seeds may be carried in particles of mud clinging to the feet of flying birds; living animals may be carried for long distances on floating ice; ships carry living animals and plants all over the world; migrating animals not infrequently distribute seeds of plants as they move about from place to place, and they may even carry living eggs and some living animals in the same way. By some of these means all organisms have an efficient method of distribution, and tend to scatter themselves in all directions from the centers, where they are produced in large numbers. Although the dispersal may be slow, in the end even the most slowly migrating animal or plant might be distributed over the face of the earth. All organisms tend to disperse themselves until further migration is checked. The factors which check their migration are spoken of as barriers. Barriers. — The ocean. — Bodies of salt water are effectual barriers against the distribution of land animals. Flying animals cross small bodies of salt water, and animals and plants that are blown by winds may be distributed over the ocean is an effectual barrier. The land. — For marine animals, the land proves to be an effective barrier. Although the conditions are essentially the same on both sides of the isthmus of Panama, the animals on the two sides of the isthmus are different, the narrow land barrier being sufficient to prevent animals from crossing from sea to sea. Land is also a fairly effectual barrier in preventing the water animals of one river system from passing to another. The inhabitants of the river may distribute themselves over a wide territory, but they are usually unable to pass from one watershed to another, except as they may be carried by incidental means. Mountains. — The high mountain ranges are perhaps the most effectual barriers of all. Practically no animal or plant is able to cross over the higher mountain ranges. Hence it sometimes happens that the animals and plants upon the two slopes of high mountains may be quite different, even though the climatic conditions on the two sides are essentially the same. Climate. — Each animal and plant is able to live only in certain conditions of climate. Hence the climate of a territory is a determining factor in regulating its inhabitants. In their distribution, animals and plants are frequently completely checked when they reach territories in which the climate is unadapted to them. This may be the result of several different factors. 1. Water. — The absence of water is a most effectual barrier to the distribution of either animals or plants. Deserts are uninhabited by any form of life, since no protoplasm can exist without water. Although most forms of life need a moist climate, some prefer one that is moderately dry and cannot live in moist territories. Deserts and semi-deserts will, therefore, be barriers for the greater number of animals and plants, while moist climates will be effectual barriers for the type of organism which prefers a semi-dry climate. 2. Food. — Animals and plants are limited to territories which furnish the food on which they subsist. A territory that fails to produce sufficient food for any given type of animal will prove an effectual barrier. 3. Temperature. — Forms of life adapted to a warm climate cannot live in a cold climate, and vice versa. The temperature of a territory is, therefore, a highly important factor in determining its inhabitants. Most animals living in cold regions will not pass over the equator, and those adapted to the warm equatorial climate cannot distribute themselves over the colder regions. Enemies. — Every animal and plant has its special enemies. These enemies are sometimes in the form of parasites; they may be larger animals and plants, or other organisms that are contending for the same food. The mutual rivalries of organisms make one of the most complex problems of biology, and one that presents an endless puzzle. The introduction of any new animals into an old territory may produce unexpected changes in the life of the animals and plants, the newly arriving organisms seizing the available food, or destroying the life of other animals and plants, and giving rise to modifications in the fauna and flora, which can never be anticipated or predicted. The complexity of these relations is indicated in a famous example given by Darwin. The clover crop is dependent upon the bumblebees, which distribute its pollen and produce proper fertilization; the number of bumblebees is dependent upon the number of field mice who eat them; the field mice in turn are eaten by the cats; so that in this roundabout way the number of cats in a territory regulates the clover crop. Change of type under new conditions. — The distribution of any particular species of animal or plant is modified by another factor of a different nature. When an animal migrates into a new territory, and comes under totally different conditions as to food, climate, and enemies, it is very apt to begin to change. These variations from the original type may, in the new terri- tory, prove of special advantage rather than of disadvantage, and will be preserved, while the original type may be destroyed. In the new locality, the species often assumes a form quite unlike the original type, and becomes so differentiated that the descendants can hardly be recognized as belonging to the original species. This peculiar feature is especially noticeable on some of the oceanic islands. Such islands may be hundreds of miles from the mainland and only occasionally visited by accidental stragglers; but they develop peculiar types of animals and plants distinctly their own, although originally coming from the mainland. So different do they sometimes become that they can hardly be recognized as close allies of the mainland types. Although this change of type in new localities is especially noticeable on oceanic islands, it undoubtedly occurs on the continental areas as well. When a species migrates into a new territory, and is placed under new conditions of food and climate, and is in rivalry with new enemies, modifications of the original type are sure to develop, and in the end the form adopted is more or less different from that of the original immigrant, which may be limited to its original home. DISTRIBUTION OF ORGANISMS IN TIME: PALEONTOLOGY Geology discloses the fact that the earth's crust is made up of a series of rocks which have been deposited during the long ages of the past; and by the study of these successive layers of rock we can learn various facts concerning the history of the world during the time when the different strata were deposited. In many of these rocks we find remains of living organisms, called fossils, which comprised the life of the world at various periods in its earlier history. The study of these different fossil remains is known as paleontology (Gr. palaios = ancient + on = being -f- logos = speech), and gives us an outline history of organisms in the past. is only under special conditions that the body of an animal or plant becomes imbedded in the rocks and preserved in the form of a fossil. Incomplete as it is, paleontology has shown us many illuminating facts concerning the earlier life of the world. It has shown that life has been in existence on the earth for many millions of years, although we have no means of determining, even approximately, how many. It has taught that during this long series of ages there has been a constant succession of living things, one type after another making its appearance and giving place to other types. The animals and plants living to-day represent only the last step in this long series, nearly all of the species existing at the present time being of recent origin, some having been in existence only a few thousands, or perhaps even a few hundreds of years, although some of our present forms may extend back for hundreds of thousands of years in the past. The immediate predecessors of our present species were organisms much like them, and from them the present forms have doubtless been descended; and preceding these were others, still more remote in time and more unlike the present ones in structure, representing still earlier ancestral forms. The general history of any series of types has been approximately as follows: Appearing in a certain part of the world, a group of animals has dispersed itself more or less over the face of the earth, becoming numerous in species and giving rise to a variety of subordinate types. The development has commonly gone on until a climax has been reached, after which the particular type has perhaps remained constant for a time, but eventually declined toward its final extermination. As it disappeared, its place was taken by some other type, better adapted to the new conditions of the changing world. So the progress has gone on age after age, type after type appearing, developing, culminating, and then declining and disappearing. type from lower to higher forms. The first organisms, appearing in the oldest rocks, were simple forms of low structure, while the highest forms of organisms appeared in the most recent ages. While the progress has not been uniformly constant, the general trend has always been upward. The invertebrates, which contain the lower animals, appeared and culminated first, while the vertebrates appeared later. Among the vertebrates the fishes appeared in the earlier rocks, the amphibia came next, reptiles and birds followed, and finally the highest group, the mammals, appeared last, with man at the extreme end of the series. It is true that in this long succession of ages, some forms of organisms have degenerated, becoming simpler and finally disappearing, while others have remained constant for immensely long periods of time without any apparent change. But the general tendency of the whole history has been one of progress from a low form to a higher, from the simple to the complex; and the living world to-day represents the culmination of a long period of progress from the earliest times. This progress, as disclosed by the fossils buried in rocks, is, in a very general way, parallel to the progress of the individual animal as it develops from the egg, through the series of changes which we have learned to call embryology. The parallel between embryology and paleontological history has been one of the striking discoveries of biological study, and has been one of the great factors in the disclosure of the unity of the living world during these long ages. All the facts to-day assure us that there have been uniform laws and forces extending through the whole series of living organisms, from the earliest geological ages to the present, and from PROTOZOA to MAN. In this index all defined words are printed in black-faced type; words to which only page reference is given are in roman type. In addition to the words used in the text, definitions are given for some of the more common biological terms. These may be recognized by their lack of page references. produce the sperms, 271. anthropoid (Gr. anthropos = man). — Resembling man. anus. — The posterior opening of the digestive tract; the vent, 157. aorta. — The large main artery which carries blood to the lower part of the appendages. — • Elongated projections from organisms, with special functions; like legs, tentacles, etc., 175. appendix vermiformis. — A small, blind sac attached to the end of the large plants that produce small eggs, 271. arteries. — Blood vessels carrying blood from the heart, 190. articular (Lat. articulus = a joint). — Pertaining to the joints, 177. ascent of sap. — • The flow of liquids from the roots to the leaves, 126. Ascomycetes, 99. bone, 27, 176. brachial (Lat. brachium = the arm). — Pertaining to the arm, 190. bract. — A leaf in the axil of which a flower is developed, brain. — The enlarged front end of the nervous system in vertebrates, 192: occurs, 214. bronchi. — The larger branches of the trachea leading to the lungs, buccal. — Pertaining to the mouth, 185, 284. budding. — Reproduction by the formation of buds which may become calcaneum, 182. calciferous (Lat. calx = lime + ferre = to bear). — Lime-producing, 169. callosities (Lat. callum = a thick skin). — Thickenings of the skin, calyx. — The outer row of leaves of a flower, usually green, 119. cambium (Lat. cambire = to exchange). — The layer of active, growing cells centrosphere, 34. centrum. — The large central disk of bone in a vertebra, 177. cephalic (Gr. kephale = head). — Pertaining to the head, cerebellum. — The larger of the two divisions of the hind-brain, 193. cerebral ganglia. — The large ganglia in the head of an animal, usually two chromosomes (Gr. chroma = color + soma = body). — The threads of chromatin formed preliminary to cell division; the number is constant in each species of organism, 85. consciousness, 5, 213. conservation of energy, 294; applied to organisms, 303. constructive processes, 139, 225, 299. contagious. — Having the character of passing readily from person to eye, 196. corolla. — The second row of leaves in a flower, usually colored, 119. coronary arteries. — Arteries supplying the heart, corpuscles. — Any small bodies, but chiefly applied to floating cells in the as the cerebral cortex, 104, 112. cotyledons. — The leaves of a plant in the seed, 123. cranial nerves. — The nerves arising from the brain, 194. cranium (Gr. cranion = skull). — That part of the skull that holds the brain, tions into the blood. ducts. — The large spiral or otherwise marked cells in the fibrovascular bundles; vessels, 106. In animals the tubes that carry the secretions of glands to the exterior, 105. the roots of plants, 113. endogenous stem (Gr. endon = within + genes = a producing). — Stems in which the fibrovascular bundles are irregularly arranged, with no cambium, wood ring, or bark, 112. central end organs are recognized, enemies, relation of animals to, 382. energy, 292; stored by plants, 299. English sparrow, 345. enteron. — The alimentary canal, 158. entire. — Of a leaf margin, without indentations, environment. — The surroundings which influence organisms, 351. enzymes. — Substances secreted by organisms and having powers of fermentation; unorganized ferments, 306. the glottis, which prevents food from passing into the windpipe, epiphysis. — -Same as pineal gland, 193. epithelio-muscle cells. — Cells of the ectoderm of Hydra, with contractile fibers extending from their base, 143. epithelium (Gr. epi = upon + thele = nipple) . — Cell layers covering surfaces or lining canals or cavities, 169. equatorial plate. — The flattened mass of chromosomes formed between fern, life history of, 269. fertilization. — The union of the egg nuclei and the sperm nuclei, 122, 249, 251, 257, 263. In botany the term is frequently erroneously applied to the transference of pollen to the pistil, 277. fibrovascular bundles (Lat. fibra = fiber -f- E. vascular). — Bundles of long cells of various shapes, extending lengthwise and strengthening the stems of the higher plants, 104. one, as in fertilization or conjugation, 65, 241, 257. gall bladder. — The sac which temporarily stores the bile, 187. gamete (Gr. gamete = husband or wife). — One of the uniting cells in sex animals. See page 285. gemmae — Special buds formed for reproduction, gemmules, 243. gemmation. — The same as budding, 239. gemmules. — Special buds which break away from the parent and become enslaves the other, 228. hepatic (Gr. hepar = liver). — Pertaining to the liver, hepatic vein. — The vein from the liver, 190. herbivorous (Lat. herba = grass + vorare = to eat). — Feeding upon grass, of animals, i. e., nourished wholly on organic foods, 221. homocercal. — Applied to a tail-fin with both lobes equal, homologous (Gr. homos = like + logos = ratio). — Similar in structure, hi the frog. hypha. — One of the filaments of a mycelium, hypoblast. — Applied to the endodermal layer in the embryo, hypophysis (Gr. hypo = under + phuein = nature). — See pituitary body, lower parts of the body to the heart: same as posterior vena cava, 190. infundibulum. — Any funnel-shaped or dilated organ, 193. infusion. — A preparation made by steeping a substance like hay in warm Hydra lying between the cnidoblasts and the muscle cells, 143. intestine. — The digestive tract from stomach to cloacal chamber, 186. intracellular (Lat. intra = within + cellular). — Lying within the cells, intracellular digestion, 146. inward, as when the finger of a glove is pushed into the palm, invertebrata. — A name given to all animals below vertebrata. invertion. — The splitting of a molecule of cane sugar into two molecules kingdoms. — The two divisions of organisms, animals and plants, 373. lachrymal (Lat. lachryma = a tear). — Pertaining to tears, lacteals. — Lymph vessels, carrying absorbed fat from the intestine, 192. life force, 4, 323. ligaments. — Bands of connective tissue connecting bones, 184. lingual (Lat. lingua = tongue). — Pertaining to the tongue, 190. linin. — The delicate fibers extending through the karyoplasm and forming lungs, 191, 209. lymph. — The liquid part of the blood after it has passed out of the capillaries into the tissues, 176, 192, 208. lymph glands. — Glandular swellings on the lymph vessels, which belong to insects and Crustacea. mantle. — A fold of skin more or less enveloping the body of an animal, marrow. — The soft material filling the cavities of bones, maturation (Lat. maturare = to make ripe). — The final changes by which of chemical and mechanical forces only, 41. medulla oblongata. — The posterior part of the brain, 193. medullary rays (Lat. medulla = marrow) . — Bundles of cells extending from a developing embryo, 283. mesogloea (Gr. mesos = middle + gloios = glue). — The middle, non-cellular layer of Hydra and allied animals, 143. mesophyll cells (Gr. mesos = middle + phyllon = leaf). — The irregular, which an organism passes through several unlike stages, more or less independent, 72, 289; of frog, 280, 286. metaphase. — The second step in karyokinesis, 87. Metaphyta (Gr. meta = beyond + phyton = plant). — Plants made of in water, largely microscopic. plantigrade. — Walking on the palms of the hands or the soles of the feet, plasma. — The liquid portion of circulating blood, 191, 205. plasmodium (Gr. plasma = substance). — A jelly-like mass. Plasmodium malarice, 69, 239. plastids. — Miscellaneous bodies within a cell, 37. platelets. — Minute bodies in the blood of vertebrates, 192. pleura (Gr. pleura = a rib). — Membranes surrounding the lungs. . plexus (Lat. pleclare = to weave). — A network of nerves, 194. pneumogastric (Gr. pneumon = lung + gaster = stomach). — A large, cerebral nerve extending down the neck and supplying the heart, lungs, and stomach, 194. polar cells. — Small cells extruded from the egg during its maturation, 254. pollen. — The male spores produced by a flower, 119. pollen tube. — An outgrowth from a pollen grain which pushes through the pollination. — The transfer of the pollen to the stigma, 277. polygamous (Gr. polus = many + gamos = marriage). — The sexual association of one male with several females, polymorphism (Gr. polus = many + morphe = form). — The property of egg, ready to unite with each other, 254, 257. prophase.— The preliminary stage in karyokinesis, 85. prostomium (Gr. pro = before + stoma = mouth). — The sensitive lobe protoplasm (Gr. protos = first + plasma = substance) . — The living substance of organisms, 29, 30, 40, 48. Protozoa (Gr. protos = first + zoon = animal). — The unicellular animals, reaction. — A response to an external stimulus, 43. recapitulation theory. — See repetition. receptacle. — In botany, the end of the flower peduncle on which the floral the muscles, but without volition, 212. regeneration. — The redevelopment of parts that have been lost, 150. reintegrate. — To recombine compounds that have been disintegrated, renal. — Pertaining to the kidneys, renal portal vein. — A vein from the legs of the frog that breaks up into respiration. — The exchange of gases between organisms and their environment, 56, 138, 160, 225; explained, 209, 312. reticular theory of protoplasm, 31. reticulum. — A network, 32. saccule, 198. sacrum. — The fused vertebrae between the hip bones, salivary glands. — Glands secreting saliva, 204. saprophytes (Gr. sapros = rotten + phyton = a plant). — Plants which live in higher plants only, for the purpose of distribution, 122. seedling. — The young plant in a seed, or just sprouting from a seed, 123. segmentation. — A term describing the division of the earthworm into segment. — The name applied to the rings of which a body like the earthworm is composed; melameres, 155. segregation (Lat. segregare = to separate). — The grouping together of by external stimulation, 167, 172, 195, 212. sensitiveness. — Same as irritability, 219. sensitive plants. — Plants which respond quickly to touch by closing their septa. — Partitions separating chambers, especially in the earthworm, 157. serous. — Applied to glands secreting a thin, watery liquid, serous membranes. — Membranes lining the body cavity and thorax, serum. — The liquid part of the blood after the clot has separated, setae. — Minute bristles serving to aid the earthworm in locomotion, 167. sexual reproduction. — Reproduction by union of eggs and sperms, 71. relations of organisms in forming societies, 20. somaplasm (Gr. soma = body + plasma = substance) . — The bit of the germ substance in the egg that is set aside in the developing egg to give rise to the new individual, 332. does not show differentiation into root, stem, and leaf, 37.5. thallus (Gr. thallos = a shoot).— A flat leaf or branch, thermotropism (Gr. thermos = heat -f- trope = a turning) . — Reaction to the lower parts of the body to the veins in the neck, 209. thymus. — A ductless gland in the neck, especially prominent in the young, thyroid gland. — A ductless gland in the neck below the larynx, tibia, 182. vital energy, or vitality, 41, 309, 319. vitalistic theories. — The theories that regard life as a distinct force, 323. vitelline membrane (Lat. vitellus = yolk). — A cell wall of an ovum, 249. vitreous humor (Lat. vitrum = glass). — The transparent liquid back of the lens and filling the eyeball, 197. viviparous. — Producing young alive, 290. vocal cords. — The membranes in the larynx whose vibration produces the	143,467	common-pile/pre_1929_books_filtered	biologyintroduct00connrich	public_library	public_library_1929_dolma-0023.json.gz:267	https://archive.org/download/biologyintroduct00connrich/biologyintroduct00connrich_djvu.txt
E-W16nuKrpnHcL03	The Story of the Bank of England (A History of English Banking, and a Sketch of the Money Market)	Produced by Graeme Mackreth and The Online Distributed Proofreading Team at https://www.pgdp.net (This file was Internet Archive) [Illustration: THE BANK OF ENGLAND.] THE STORY OF THE Bank of England (A History of English Banking, and a Sketch of the Money Market) BY HENRY WARREN AUTHOR OF "YOUR BANKERS' POSITION AT A GLANCE" ETC. JORDAN & SONS, LIMITED 116 AND 120 CHANCERY LANE, LONDON, W.C. 1903 LONDON: PRINTED BY JORDAN AND SONS, LIMITED, 120 CHANCERY LANE, W.C. CONTENTS CHAPTER PAGE I. The Period of Monopoly, 1708 to 1826 1 II. Before and After the Act of 1844 24 III. The Bank's Weekly Return 48 IV. The Issue and Banking Departments 63 V. The Store in the Issue Department 74 VI. Weekly Differences in the Return 85 VII. The Bank as Agent of the Mint 94 VIII. The Principal Currency Drains 101 IX. Banks and the Creation of Credit 113 X. The Battle of the Banks 126 XI. The London Money Market 139 XII. The Bank Rate and Stock Exchange Securities 154 XIII. The Banks as Stockbrokers 161 XIV. The Short Loan Fund and the Price of Securities 169 XV. Panic Years 177 XVI. The Banks and the Public 224 XVII. Bank Stock 240 CHAPTER I. The Period of Monopoly, 1708 to 1826. The Bank of England, which is managed by a Governor, Sub-Governor, and twenty-four Directors, was incorporated in 1694 at the suggestion of a Scotsman, William Paterson, a man of roving disposition, whose Darien expedition proved a miserable fiasco, cost Scotland some £400,000, and shattered the health of Paterson, who died in London at the beginning of 1719, if not in poverty at least stripped of nearly all his fortune. Schemes relating to the Isthmus of Darien (or Panama), that narrow little strip of land which unites the two Americas, have proved fruitful in disaster. France's great canal venture, we all remember, resulted in huge loss and grave scandal; and Paterson lived to bitterly regret his colonisation scheme, devoutly wishing that he had pinned his faith to his finance company, the Bank of England, for a finance company it then was in every sense of the word. Little is known of William Paterson's early career, the various accounts relating thereto being meagre and conflicting, his enemies describing him as a mere adventurer, and his friends declaring that he was actuated by the worthiest of motives. However, when it is remembered that his second great venture (the Darien scheme) involved thousands in ruin, it is evident that had the man been a saint he would not have lacked detractors, and though his public utterances sound quaintly pious to the modern ear, it seems probable that he was only an enterprising merchant, whose morality was neither better nor worse than that of the times in which he lived. The son of a Scotch farmer, Paterson left home at an early age, and, after settling for a short time in the West of England, set sail for the West Indies, returning to Europe about 1686 with the Darien scheme in his brain. Receiving but scant encouragement in England, despite the fact that his bank had been successfully floated, he concentrated his energies upon Scotland, where his scheme fired the public imagination, almost every Scotsman with a few pounds to invest eagerly taking the money to the company, convinced that Panama was the natural commercial centre of the world, and that gold would be rained therefrom upon fortunate Scotland. The whole nation went almost frantic with the fever, for Panama, with its gold mines and its world-wide trade, was going to make Scotland rich beyond the dreams of avarice. It is estimated that nearly half the capital of the country was sunk in the Darien scheme. Chartered by the Scottish Parliament in 1695, three vessels sailed from Leith in July, 1698, with some twelve hundred settlers on board, Paterson and his wife among the number. All Edinburgh flocked down to Leith to wish the members God-speed, and then returned to their homes to dream of the streams of gold with which Scotland was to be flooded. In a few years everybody would be rich, and Edinburgh would be the greatest and proudest city in the world. Trade, however, was destined to flow to a city a little farther south. The scheme proved a dismal failure. England and Holland opposed the new colony; the East India Company treated it as a rival, and Spain was actively hostile. The climate did the rest. Before the close of 1699 "New Edinburgh" was deserted, and the colonists, decimated by want of provisions and disease, set sail for New York. To make matters worse, a second company meanwhile had sailed from Scotland, where the utmost enthusiasm still prevailed; but the new arrivals found the town deserted, and themselves at the mercy of the Spanish warships. Mad with rage at the lack of success of their national adventure, the Scotch openly accused the English Government of treachery, declaring that its conduct in withholding food supplies was as discreditable to it as was the butchery of Mac Ian and his clan at Glencoe in 1692, when neither old man nor child was spared, and fugitives were allowed to perish of hunger and exposure in the mountains. Paterson's faith in Panama must have been profound. His wife died in the new colony, and he himself suffered severely in health; yet, after his return towards the end of 1699, directly his health began to improve, we read of his approaching William with a fresh Darien venture. The King naturally refused to risk a second disaster, and Paterson, like all great speculators who have risked everything and lost, could not again persuade the public to share his enthusiasm, for that mysterious entity seldom trusts a man after a cloud has obscured his "star." Once his spell of so-called good luck is broken, the public desert him in a body, when the adventurer, if he be wise, retires into obscurity with his spoil. Paterson lived to discover that it is only a rising star, radiating success, that can obtain a sufficiently large following to finance a great scheme, and though he strove manfully to promote the new venture, his sanguine predictions were received sceptically. Nor did his subsequent schemes meet with a better reception. But he must still have retained some influence, for, after the Act of Union in 1707, he was returned to Parliament by a Scotch burgh. His chief claim to distinction, however, undoubtedly rests upon the fact that he founded the Bank of England, of which he was appointed one of the first directors. The Bank of England, from its inception down to the present day, has never been a Government institution. It was originally simply a company that advanced money to and transacted business for the Government, which, in return, granted it certain privileges and concessions; but the connection between the Government and the Bank was so close, and their interests so identical, that public opinion connected the one indissolubly with the other. From this conception sprang the erroneous impression that the Bank is a Government establishment, when, in reality, it is no more so than is the National Provincial Bank of England or the London and County Bank. In 1694, the Government of William III., which was generally in a state of monetary tightness, found that the war with France was draining its resources, and, having failed to raise sufficient funds by the imposition of taxes, it resolved, apparently as a kind of _dernier ressort_, to accept Paterson's financial scheme, which had been shelved some three years earlier; and on 27th July, 1694, a charter was granted to the "Corporation of the Governor and Company of the Bank of England." The capital of the company, £1,200,000, was subscribed by some forty London merchants, and lent to the Government. It is only reasonable to assume that the subscribers were supporters of the Government, and that they were Whigs, whose aim, in supplying William with the sinews of war, was the crushing of James, whose pusillanimity had disgusted even his own followers at the battle of the Boyne in 1690. Then, again, the commercial morality of the Stuarts was notoriously bad in the City. Charles I., when the City of London refused him a loan, took forcible possession of £200,000 deposited by the Goldsmiths in the Exchequer; and Charles II., in 1672, robbed them of considerably over £1,000,000. The Goldsmiths, in those days, were the private bankers with whom the London merchants left their cash, receiving an acknowledgment or receipt in return, promising payment on demand, and the Goldsmiths deposited their surplus cash in the Exchequer, just as the banks of to-day do with the Bank of England. Through this act of spoliation the Goldsmiths were unable to meet their liabilities, and many of them, together with their customers, were involved in common ruin in consequence. James II. added to the financial sins of his house by debasing the currency: so small wonder that the merchants of London had had enough of the Stuarts, whose theory of the "Divine right" of kings did not even stop short at the pockets of their subjects--always their most vulnerable point. The Bank of England, which to-day is quite outside party politics, was at its inception a Whig finance company, incorporated solely for the purpose of lending its capital to the Government at the rate of eight per cent. per annum; and out of this creation has evolved the present "Old Lady of Threadneedle Street," whose career, if chequered, has been one of unquestionable integrity. It is difficult even in imagination to picture to oneself the England of 1694; but it is easy to understand that in those days great storehouses of capital were non-existent--non-existent, that is to say, in the modern sense. Our huge credit institutions, which are indispensable in the twentieth century for the proper carrying on of trade, and which dive by means of branches into almost every corner of the land, thereby collecting millions of pounds of loanable capital, would have spread their tentacles in vain during the seventeenth century, when neither the money nor the facilities for its profitable employment existed in the country. Capital was scarce--consequently the rate of interest was high--and eight per cent. was a rate at which even the Government could not borrow in the City in 1694, from ten to thirteen per cent. per annum being about the value of loanable capital, while the commission paid was oftentimes exorbitant. The Bank, which was established by the Whigs, was naturally bitterly opposed by the Tories, who saw in its success the destruction of the cause they had at heart. The capitalist class disliked it for selfish reasons; and the Goldsmiths, recognising a formidable opponent, joined issue with its enemies. Holders of stock and everybody connected with the Bank were looked upon as enemies of the House of Stuart, which, were it restored to power, would naturally wreak its vengeance upon a company that had helped to finance William--for forgiveness is one of those abstract attributes with which only brave and wise men are blest, and James II. had not given proof of possessing either courage or wisdom. Small wonder then that the City should support the Dutchman. The National Debt, too, was founded during the reign of William, the first loan of £1,000,000 being raised in 1693, and those persons who held it were bound by the strongest of ties--commercial ties--to William. The fund-holders were Liberal; the Bank was Liberal; and as its very life was dependent upon the existence of the Government, it seems only natural that, in the popular mind, it should have been looked upon as a Government institution, though there is but little excuse for so classing it now. The fact that so many people still share this illusion, however, clearly proves that a large proportion of the public is unacquainted with the Bank's history. The Bank of England's charter was renewed in 1697, and again in 1708, when, in order to prevent the establishment of similar institutions, it was granted the monopoly of Joint Stock Banking in England. This it retained until 1826, when an Act was passed permitting the formation of Joint Stock Banks of Unlimited Liability beyond sixty-five miles of London, provided they had no branches in the Metropolis. It is a long jump from 1708 to 1826, and, of course, the charter was renewed many times between the two dates, the Government generally taking advantage of each extension to force some concession from the Bank, which, as its credit and business expanded, had increased its original capital by many millions; but 1826 was the year of reform, and the intervening period possesses little interest except to the student. Between 1826 and 1829 the Bank opened eleven provincial branches, but those which were established at Gloucester, Swansea, Exeter, and Norwich have since been closed. Joint Stock Banks were then started in the provinces, though not with very happy results, for in 1832 their reckless trading was severely stigmatised by Lord Overstone; but it was not until 1834 that the first joint stock bank, the London and Westminster, was started in London, a clause having been inserted in the Act when the charter of the Bank of England was renewed in 1833, to the effect that, provided a joint stock bank did not issue notes, it was at liberty to carry on business in the City. Both the Bank of England and the London private bankers opposed the new bank with acerbity, the former refusing to open an account for it in its books, and the latter declining to admit it into the Clearing House. Not satisfied with this, the Bank brought an action against the Westminster. But it was quite natural that the newcomer should have been received in this fashion, for innovations, however necessary and useful, are seldom accepted rapturously in this country, which appears to have almost a Chinese dislike of the unusual. Besides, it is not the custom of the country, even for the sake of appearances, to receive a trade rival with open arms, and it would have been a little surprising had the Bank surrendered its monopoly of joint stock banking in England without a struggle, whilst its desire, after being stripped of some of its privileges, to annoy its despoilers, was, if not laudable, eminently human. In 1836 the London Joint Stock Bank followed the example of the Westminster, and in 1839 the Union Bank of London, which has recently amalgamated with Messrs. Smiths, opened its doors, while such well-known banks as the National Provincial Bank of England and the London and County Bank were formed in 1833 and 1836 respectively. The trade of the country had by that time far outgrown the resources of the Bank of England, which was quite unable to minister to the increasing demands of a prosperous and progressive England; and to-day the only monopoly which the Bank enjoys is that left to it by the Act of 1844. From William and Mary to Victoria, in whose reign the Act of 1844--that Magna Charta of the banking community--was introduced, covers a most interesting period in the history of the nation, whose development had been retarded by the "Divine right" of the Stuarts, which cost Charles I. his head and James II. his throne. The theory is much in evidence to-day, though it now takes the form of a great abstract idea, not compatible with practical politics, and which has found a resting place in the heart, rather than in the head, of the people--for the practical twentieth century has a strange trick of banishing disproved theories from the head to the heart; and perhaps it is this national trait which saves the country from violent revolutions. It would be a mistake to assert that commerce had declined under the Stuarts. It increased rapidly in spite of them; but, after the "Glorious Revolution," the "Divine right" of kings became a mere theory in this country, and the power of the Crown was made subservient to the will of the people. In short, the rule of Parliament began. The trade of the country gradually expanded, and with it the influence of the Bank. In order that we may thoroughly grasp the position previously occupied by the Bank of England, and the influence given to it by its connection with the Government, it will be better, before briefly discussing the Act of 1844, to revert to the days when the sway of the Bank of England was absolute. In 1708, we know, the Bank was granted the monopoly of joint stock banking in England, and, further, it was made illegal for any private firm, whose partners were more than six in number, to conduct the business of a banker. This restriction was not removed until 1857, when the partners in a private bank might consist of ten, and it will be seen from the following facts that this limitation was harmful to the best interests of the country. One result of this hard-and-fast enactment was the encouragement of small private banks in every county of England; but the fact that the number of their partners was limited to six effectually checked their expansion, and finally brought hundreds of them to the ground; for they could not strengthen themselves, and add to their resources, by amalgamation as is now possible. As the population of the country increased, the position of the private bankers, as a class, became precarious, especially in rapidly growing commercial centres, because their supply of loanable capital was insufficient to meet the increasing demands of their clients. In their attempt to finance their customers they neglected to maintain adequate reserves, and consequently failures were numerous directly any very considerable demand was made upon them. Instead of a few large and powerful banking companies, there existed numerous weak private firms, which, in many instances, had advanced out of all proportion to their total working resources, thereby sacrificing security to large profits. So long as times were good all went merrily; but, unfortunately, the great impetus given to trade by the conclusion of peace with France and the United States in 1783 did not last more than five or six years. The year 1789 brings us to the French Revolution, and in 1793 we were at war with France again. Then came the reaction. Country bankers failed in every direction; but in 1797 Mr. Pitt came to the rescue in order to relieve the Bank of England, and the directors of the Bank were allowed to issue notes at their discretion, cash payments being suspended. Between 1792 and 1820 over one thousand private bankers put up their shutters; and during the 1825 crisis sixty-five banks closed their doors, hundreds of their customers being ruined in consequence. The panic of 1825, which almost emptied the Bank's tills, thoroughly convinced the Government that the country had outgrown the monopoly of the Bank of England. By limiting the partners in private banking companies to six in number, and prohibiting the establishment of joint stock banks in opposition to the Bank of England, the Government sanctioned a policy which could not but result in disaster. Like most monopolies, that of the Bank of England was framed to exclude powerful rivals, and to keep those in opposition small and weak; and the result was disaster and ruin in every direction. The greater the trade of the country, the more apparent became the evil, until even the Government was compelled to decide that the monopoly of the Bank of England must forthwith be curtailed. Small tradesmen were quick to realise the possibilities attached to an unlimited issue of notes, and hundreds of them combined the business of banking with their retail trades, for, although the law placed every obstacle in the way of sound banking, it encouraged small men, who possessed little or no capital, to engage in a business which should be conducted with much capital and great caution. The country was flooded with the notes of these so-called bankers, who, directly their notes were presented for payment in large numbers, failed by the dozen. A system which encouraged all that was bad, and excluded everything that was sound and secure, was naturally doomed to extinction; and small wonder that in 1826 the era of country joint stock banking began. Like most fresh ventures which cannot be guided by precedent, it began disastrously, for the simple reason that those who were responsible for the guidance of the new companies had to learn from experience--a very bitter school. But the new banks laboured under fewer disadvantages than the old private bankers, and the Bank Act of 1844, we shall see, clearly defined their position. We can now understand why the private banker was never a great success in this country. He was of course sacrificed to the monopoly of the Bank of England; for although six very rich capitalists could conduct a large banking business, the resources at their command would not be sufficient to enable them to extend their branches throughout the country. Consequently, before the advent of the joint stock banks we find the private banker, broadly speaking, confining his connections to a particular district or county. It is true that he enjoyed free trade in banking down to 1844; but the regulation as to the number of partners in his business necessarily confined his offices or branches to a limited area, and effectually prevented his expansion on a large scale; so we get influential houses in the various counties, such as the Gurneys in Norfolk and Suffolk, the Smiths in Nottingham, and so on. It is noticeable, however, that both these well-known private firms, recognising the applicability of the joint stock system to the times, have surrendered their note issues, and taken a place in the modern movement, evidently foreseeing that, in order to progress, they must adopt the methods of their more successful rivals. Undoubtedly, the country was not ripe for such a movement until the beginning of the nineteenth century; and though the number of partners in private banking firms was extended to ten in 1857, this concession by no means placed the private banker on an equal footing with the joint stock companies, which could increase their members or partners by the issue of additional capital whenever it became apparent that their business was rapidly progressing. The private banker, had he desired to farm some dozen counties, would have been compelled to find a few large capitalists to join hands with him, whereas the joint stock banks had only to obtain hundreds of very small ones, and it is quite evident that the companies possessed infinitely the easier task. In fact, down to 1844 the monopoly of the Bank of England prevented their rapid growth. Then came the period of, so to speak, free banking; but not for the private firms. People are constantly asking: Why did not the private bankers establish themselves firmly in the country and progress? They were first in the field, and, had they been well managed, surely they would have been as progressive as their joint stock rivals. But we know that the law never gave them the remotest chance. How could they progress on a really gigantic scale when their partners were limited to six? The law literally forced them to stand aside; and in 1826 and 1833 only the joint stock system profited by the concessions wrung from the Bank of England, because by that system alone could sufficient capital be obtained to enable a bank to farm the country from south of the Tweed to Land's End. Of course the private banker was at liberty to adopt the joint stock system at an earlier date, but he did not at first believe in the new movement, and, consequently, clung to his own system until he was far outdistanced by his competitors, for directly the country was relieved from the incubus in the shape of the Bank of England's monopoly, and the joint stock system was given a free hand, that system, as might have been expected, instantly began to forge ahead, and in a very short space of time the private banker, who to this day cannot admit more than ten persons into partnership, was left hopelessly behind by a system which was unfettered by legal restrictions and allowed fair play. The Bank of England's monopoly reduced the private banker to impotency. It fostered in every county of England dangerously small firms, which disappeared in hundreds as soon as credit became bad and a state of panic caused their notes to be presented for payment in unusually large numbers, and it made really great private banking companies impossible in England; while but for the fact that public opinion wrenched this power from the hands of the directors, the Bank and its monopoly, which encouraged a dangerous form of banking, might both have been swept away in a bad financial crisis. Fortunately, public opinion won the day; and though the private banker could not compete successfully against the joint stock system on account of the smallness of his capital compelling him to concentrate his energies in a particular district, that system, being unrestricted, soon covered the land with its branches. The private bankers were at first held in check by the Bank of England's monopoly. Now they are simply being smothered out of existence by the extension of a system of which, in a manner, though, of course, not in the modern sense, the Bank was the first exponent; for a banker, at the beginning of the nineteenth century, was largely dependent upon his note circulation for his profit, our present system of deposit banking being then in its infancy. In fact, the one evolved out of the other. If a person held one hundred pounds in bank notes, it could not but occur to him that he was in reality lending the issuer one hundred pounds entirely free of interest; and as he possessed sufficient confidence in the banker to lock up the notes in his cash box, it was only going one step farther to deposit his money at his bank and draw out the cash as he required it. Obviously, too, if he exchanged the notes for a deposit receipt, he would receive some interest upon his money; and as the receipt could be held equally as safely as the notes, he naturally adopted the plan that was the more profitable to himself. So, although in 1826 the joint stock banks in the country attached great importance to their circulation, their notes rather took the form of an advertising medium for attracting deposits, or, at least, became a means to that end, for the progressive banks did not hesitate to sacrifice their note issues in order that they might open branches in London. We find, then, that the joint stock banks at first attempted to place as many of their notes as possible among the public, and that, by the process already explained, the holders of their notes gradually began to deposit with them, until, by degrees, our present system of deposit banking obtained a firm hold upon the habits of the people. As the trade of the country expanded, the cheque rapidly drove out a large proportion of the bank notes in circulation; and though the issue of notes certainly introduced deposit banking in this country, modern requirements have made cheques and bills of exchange the media for the transference of credit. Such being the case, the note issues of the larger joint stock banks became of secondary importance to them; and, rather than remain outside the Metropolis, we have seen that they sacrificed their notes to the monopoly of the Bank of England. From 1708 to 1826 the Bank of England owed its predominant position entirely to monopoly, and enough has been written to show that its sway was not an unmixed blessing to the country. The private banker, without a shadow of doubt, can trace his lack of progress to the restrictions placed upon his business by the Bank charter; and the joint stock companies may certainly be said to have succeeded in spite of the Bank; yet no greater compliment can be paid to any institution than to assert that it has earned the respect, if not the love, of its enemies; and such undoubtedly may be truthfully affirmed of the "Old Lady of Threadneedle Street," even when her rule was autocratic and her rivals' dislike of her intense. CHAPTER II. Before and After the Act of 1844. We have seen that part of the Bank of England's monopoly was annulled in 1826, and that in 1833 a clause was inserted in the charter to the effect that joint stock banks of unlimited liability could open in London, provided they did not issue notes; and though the state of the law still allowed the Bank to harass and annoy the new companies, its power was thoroughly broken, and its monopoly of joint stock banking gone--fortunately for ever. The country enjoyed a period of prosperity from 1833 to 1836, but the speculative fever soon began to develop, and by the end of 1835 it was burning fiercely, for men and women possessed an extraordinary faith in those much advertised short cuts to wealth in the early thirties. No path, if it were sufficiently short, was too precipitous. Hope was boundless, credit was unlimited, and companies in profusion were formed by the philanthropists and dreamers of those times. Then came the crisis of 1837, when the Bank's policy rose almost to the verge of madness. Just at a critical moment, when it was imperative that no untoward incident should occur to disturb the already depressed state of credit, the Bank of England refused, and persisted in its refusal, to discount bills bearing the endorsement of the joint stock banks. The action of the Bank added to the confusion, and, as speculation in America had been rampant, it dealt a final blow to the houses engaged in the American trade by issuing instructions that their bills also should not be discounted. Then, as might have been expected, the fury of the storm beat against the Bank itself; and by the end of February, 1837, its bullion was reduced to £4,077,000. In 1839 another crisis occurred, and the bullion declined to £2,522,000. Upon this occasion £2,500,000 was borrowed from the Bank of France, and the discount rate of the Bank of England was gradually advanced to six per cent. These constantly recurring panics thoroughly alarmed the Government, which, having stripped the Bank of England of its monopoly of joint stock banking, now turned its attention to the currency, and by the Bank Act of 1844 secured the convertibility of the note. In fact, the chief aim of the Act was to reduce the issues of the country bankers, who, by forcing large numbers of their one pound notes into circulation and neglecting to maintain a sufficient proportion of cash in hand to meet them on presentation, helped to finance the gamble of 1824. Some of the banks paid the penalty in the year following, and disappeared from the scene. In 1821 the Bank of England, after a period of restriction, began to pay off its notes under the value of £5, but the Government allowed the country bankers to continue issuing their small notes until the expiry of the Bank Charter in 1833. In 1826 an Act was passed prohibiting the stamping of notes under £5, and forbidding the circulation after April, 1829, of those then current. The Bank Act of 1844 confirmed the alterations of 1826 and 1833, and, in addition, made great alterations in connection with the currency. The Issue Department of the Bank of England was to be kept entirely distinct from the Banking Department. Notes, to the extent of £14,000,000, might be issued against the debt owing by the Government to the Bank and against other securities, but coin and bullion must be deposited in the Issue Department against every note issued in excess of that sum. Notes issued by the Bank of England are, therefore, secured principally by specie, and by the Government debt, which amounts (1902) to £11,015,100; and as every note is a warrant entitling the holder to gold on demand, a Bank of England note is really and truly equivalent to gold. However, under certain possible, if improbable, conditions, the Bank could not fulfil its obligations or promises to pay cash on presentation, for if all its notes in circulation were presented simultaneously there would not be sufficient coin in the Issue Department to meet them; but that is a most unlikely contingency. Further, these notes are "legal tender" in England. In other words, a debtor can compel his creditor to accept them in discharge of his debt; but nobody is obliged to give out change should the value of the notes tendered exceed the amount of the sum owing. In Scotland and Ireland Bank of England notes are "current" but not "legal" tender. Neither are they by the Bank itself, nor by any of its branches, and sovereigns, though not half-sovereigns or silver, may be demanded in exchange. All notes are convertible at the London Office of the Bank, whose branches, however, are only responsible for those notes issued therefrom. The Bank still retains the monopoly of issuing notes in London and at a distance not greater than sixty-five miles from the Metropolis. No new bank of issue may be formed; and as the private bankers in London had ceased circulating their notes prior to 1844, the Act practically gave the Bank the monopoly of note issue within the prescribed area. This monopoly alone is of great value; but when we remember that its notes are legal tender in England as well, it is evident that the Bank of England still enjoys a most important concession. The private bankers of London, and the joint stock banks in London and within sixty-five miles of it, were debarred by the Act of 1844 from issuing notes. Of course the private bankers who still issued notes within the prescribed space retained their privilege, but they were no longer able to circulate as many as they could persuade the public to accept. Bankers, both joint stock and private, who claimed the privilege of issuing notes were compelled to make a return of their issues for a period of twelve weeks to a given date, when the average amount was ascertained, and the extent of the future issue of each bank settled in accordance therewith. The issues, in other words, were fixed, and they could not exceed the sum authorised without breaking the law, and exposing themselves to a fine equivalent to the average excess during any one month. The Government, anxious to avoid a repetition of the scandals of 1825 and 1836, was evidently determined to limit the note circulations of the country banks, and there seems little doubt that, when the Act was framed, one of its aims was the slow but sure extermination of the country bank note. Banks which intend giving up their note circulations may compound with the Bank of England, which is then allowed to increase its own issue by two-thirds of the disappearing issues. The Government, however, takes all the profit accruing from such arrangements. The result of these regulations can be seen in the accretions made from time to time to the Bank's authorised issue of £14,000,000, which has now increased to £18,175,000. The majority of the issues of the private bankers fixed by the Act of 1844 have since lapsed; and the same may be said of the more progressive of the country joint stock banks, which, as their deposits grew, opened branches in London, thereby sacrificing their note circulations to the monopoly of the Bank of England, whose notes are fast driving those of the small country bankers out of circulation. Broadly speaking, it may be said that Bank of England notes are the only notes accepted readily by the English public; but the mere fact of their being legal tender ensures that. Readers who are not acquainted with the history of Banking must not assume that the Act of 1844 affects either Scotland or Ireland. The note circulation of both those countries is regulated by the Act of 1845, but in neither country are the provisions identically the same as those affecting England. Any person may demand of the Issue Department notes in exchange for gold bullion of standard fineness at the rate of £3 17s. 9d. per ounce. The Bank Act of 1844, according to its framers, would make panics and crises evils of the past; but, as a matter of fact, it was a new broom, and its sweeping powers were greatly overestimated. Its provisions, we can see, related entirely to currency reform; and though the country bankers could no longer borrow on their notes to an unlimited extent, it must be remembered that Sir Robert Peel's famous Act, if it fixed the maximum amount of their issues, did not take the precaution to also fix the minimum reserve of cash in hand to be held against them. Obviously, no Act could strengthen the position of the banks against panics unless it laid down the minimum or legal reserve of cash to be maintained against deposits, and we shall see that, in this respect, the Act of 1844 did not realise expectations. Controversy raged furiously around Peel's Act, and, needless to say, it became the bone of party contention. Whenever a subject reaches that stage in this country, its merits are forced into the background. Sides are taken, critics and politicians range themselves upon either the one or the other, and the subject, consequently, speedily gets all the truth lashed out of it. The number of people who really understand the question thoroughly is infinitesimal; and they, as a rule, by a strange irony of fate, do not dabble in politics. The important subject is therefore handed over to the tender mercies of the multitude, which, quite ignorant of its underlying principles, splits itself into two hostile camps, beats out the dust with sticks, and then returns a man to Parliament to vote on this side or on that. When in 1847, three years after the passing of the Act, another crisis occurred, public opinion attached all the blame to Peel's Act; but public opinion was wrong. Public opinion is usually based upon instinct rather than upon reason, and, consequently, carried away by a sense of indignation or wrong, it rushes madly at what it considers the cause of the mischief. In this case its bugbear was Peel's Act. The real reason was to be found in the simple fact that neither the Bank of England nor any of the large banks held a sufficient proportion of cash in hand to meet those sudden demands for gold which may be made upon a banker at any moment, and to which his business is peculiarly exposed during periods of bad credit. It was the old, old story, which in these days seems hardly to require an explanation. After a period of exceptional prosperity, there almost invariably follows a lean year or two, when loanable capital is cheap and the prices of commodities depressed. Then is the company promoter's opportunity, and schemes, wise and otherwise, are brought to the notice of the public. Presently there comes a gradual expansion of enterprise, and rising prices beget confidence, when a whisper goes round to the effect that good times are coming. At first business improves slowly and surely. Then, as prices mount higher and higher, every producer increases his output, anxious to share in the general prosperity. Suddenly, just before the end, there is a boom. Prices rush madly upwards, until every prudent man sees that business has degenerated into a mere gamble, and that he must act quickly if he does not wish to be caught by the receding tide. Unless the banks are strong at that moment, disaster is inevitable; and as they had not taken the necessary precaution in 1847, the result was a crisis. Capital was cheap during the last quarter of 1844, the Bank rate remaining stationary at two-and-a-half per cent. from September of that year to October, 1845. Cheap money gives the promoter his opportunity; and in 1845 the railway mania was at its zenith. England was in the hands of the surveyor, and the "boom" began in real earnest. As usual, everybody was to become immensely rich, and, as usual, most people were again bitterly disappointed. By a strange process of reasoning, experience does not count in finance. Hope, after a very little while, drives out of the memory of human beings the nightmare of disaster; so, in an astonishingly short space of time, they are gambling again. The crisis of 1837 had lost all its significance by 1845; and then, of course, the Bank Act was to prevent commercial panics in the future! At the end of 1846 the Bank rate was raised to four per cent., and in October, 1847, it touched eight per cent. The speculation in railways naturally resulted in a gamble in iron; and, after the terrible famine in Ireland of 1846, when thousands died of fever and want in their wretched hovels and even on the roadsides, the suspension of the Corn Laws led to large importations of foreign grain. A sudden fall in prices immediately followed the increased supply, and the merchants in Mark Lane began to fail. Then people looked gravely at one another, and inquired what would happen next. Credit is the disposition of one person to trust another; therefore as business gradually expands, credit or confidence increases at precisely the same ratio; and when prices are high and profits large, the impression prevails that everybody is making money--consequently, confidence begins to drive out caution; so, towards the end of a period of prosperity the acquisitive fever burns fiercely. Everybody is in mad haste to get rich; caution is flung to the winds; and we get a _débâcle_. Then follows a time of bad credit. That is to say, immediately after the reaction, everyone is disposed to be sceptical of his neighbour's position, to wonder whether he were hit by the recent upheaval, and to be extremely cautious in granting credit to his customers. This took place after the crisis of 1847. For a little while everybody was afraid to trust his neighbour; but by 1857 speculation was in full swing again, and the inevitable collapse followed. These periods of good and bad times, or good and bad credit, run their course with the regularity of a fever. So it was in 1847. Directly a few failures were announced, the public became alarmed, and speculation received a check. The failures continued, and every holder of bills, anxious to have money at his credit at the banks, tried to discount them. But the banks were totally unprepared for this sudden demand, and in Liverpool and Newcastle some of them closed their doors. The London bankers refused their customers ordinary accommodation, and the Bank of England at first declined to advance against securities. Bills, consequently, could not be met at maturity, and the result was panic and a run on the banks. The situation was saved by the suspension of the recently passed Bank Act, and on 25th October, 1847, the Government authorised the Bank of England to issue notes at its discretion, until the feeling of apprehension had subsided. The Bank thereupon advanced on bills and stock, and, although the rate of discount was eight per cent., the fact that money could be obtained on good bills and first-class securities speedily allayed the panic, and by 23rd November following the Act was again in force. Further, the amount issued by the Bank beyond the limit imposed thereby did not exceed £400,000, although its reserve, by 23rd October, was reduced to £1,547,000. Perhaps we shall now be better able to understand the Act of 1844, and to see that, though it effected a most useful reform in the currency, and prevented a host of weak country bankers inundating the provinces with their doubtful paper, it does not contain a single clause which would either prevent or alleviate a panic. Indeed the paradox is that during a crisis relief can only be obtained by breaking the Act, and allowing the Bank of England to advance notes freely against the better-class securities. The power to issue notes was taken out of the hands of numerous weak banks, and confided to one strong one. Perhaps, however, it would be more correct to say that the power for evil of the small country bankers was "fixed" by the Act; and, as we have seen, the Bank of England's notes are gradually driving those of the English provincial banks out of circulation. Then, again, the extinction of the country issues gave a marked impetus to our modern system of deposit banking. The cheque soon became the principal credit document in circulation, and the country joint stock banks relied absolutely for their advancement upon their ability to attract deposits to their books. So long as the Bank of England's notes can be exchanged for gold on demand, it is impossible for them to depreciate in value, and they cannot drive more gold out of the country than is equal to the Bank's fixed or authorised maximum, because, against every note issued in excess, specie for a like amount must be deposited in the Issue Department. Certain writers urge that this limitation is an interference with the freedom of the banker; but, seeing that our modern system of banking rests upon so small a cash basis, surely it is absolutely essential that our currency at least should be above suspicion in times of falling credit. The public does not require notes then. It wants credit; and this it obtains in the books of the banks. The currency, certainly, should be left absolutely to the laws of supply and demand; and though it is true that the Bank of England sometimes has to protect the convertibility of its notes by raising its rate of discount, still, our present system approaches very near to perfection in so far as the exchange of the note for gold is concerned, and it certainly does not seem desirable to have the country again flooded with paper money which may, or may not, be paid on presentation. Any person who possesses gold can have it turned into coin immediately; so, under our present system, every addition to the currency must come either direct from the mines or else be received in settlement of the balance of indebtedness owing by foreign nations to this country. We are, therefore, spared those evils which result from an over-issue of paper, and which were sometimes so greatly in evidence before the passing of the Act of 1844. The absurdity of the attack on the Act must now be apparent, inasmuch as the only reform it could possibly effect was a currency reform, which was certainly badly needed. Viewed in that light it must surely be acknowledged that the Bank Act of 1844 is one of the soundest financial Bills that has ever become an Act of Parliament. The fact that, in spite of the great change in our banking system--which may be said to have been revolutionised since 1844--the Act has successfully stood the test of time, is also proof positive (if proof were required) that it was framed with great skill and judgment. Had the Act further decreed that every bank should maintain a ratio of, say, at least eighteen per cent. of legal tender against its public liabilities, even panics might have been avoided. At any rate, the banks would have been better prepared to meet drains upon their resources, though even then--as has been pointed out is the case with the Act itself--the law would have to be broken directly a run was made on the banks by their customers. For all that, such a regulation would keep the banks in a fair state of preparedness during normal times, and consequently every bank in the land would be ready to face a panic. Our system of credit is based on a small cash reserve; and it would be impossible to devise any workable scheme which would afford bankers absolute security, because it would prove too costly both to the banks themselves and to their customers, who would have to pay much higher rates in proportion as the depositors' money was secured. The most prudent banker can only insure his business up to a certain point, as, if he kept more than a certain proportion of cash in hand, he would conduct his business at a loss; so if a panic take possession of his customers and they rush for gold, he is lost if the demand should drain his reserve and encroach on his till-money. No system in the world could possibly save him then. The most our banks can do, therefore, is to be prepared to a certain extent, and, viewed in the light of past history, it is criminal of directors not to take the ordinary precautions. A clause in the Act, as already suggested, would at least ensure a fair state of preparedness in all our banking companies, and beyond that it is impossible to go. It has been shown that the Act works most effectively in a time of panic when it is broken. It is, perhaps, interesting to recall that the Bank of Germany, in order to remedy this defect, is allowed to issue notes beyond the authorised amount at its own discretion; but the German Government, in order to check abuses, makes over-issue an unprofitable transaction for the Bank by imposing a fine of five per cent. on any amount issued in excess of the authorised limit. Were our own Government to adopt the same expedient, the Bank of England, during a time of stress and excitement, could meet all demands automatically, and the Act would be almost perfect of itself. On the other hand, the Government might not like to see so much power pass into the hands of the directors of the Bank, though there can be little doubt that they would use it with the greatest moderation and to the public advantage. The object of this chapter is to show that panics were not lessened in any degree by the Act, and perhaps it may be said that the fact has been dinned into one's ears to the verge of irritation. But an ardent reformer's feelings are strong, and it is difficult to make this subject clear to those who are not conversant with the history of Banking, and who, perhaps, are disposed to think the subject both dry and uninteresting. The panic of 1847 was followed by another in 1857, and in 1866 the Overend and Gurney crisis occurred. From 1866 down to the present day, unless we include the Baring scare in 1890, the country has been free from these scourges, and the reason is not very far to seek. The Act of 1844 placed the currency of the country on a sound basis, and experience, by teaching the banks caution, did the rest. The large banking companies, after the terrible panic of 1866, plainly recognised that advances must be made with great discretion, and that, if they valued their own safety, speculation must be either kept well within bounds or discouraged entirely. Merchants and traders who require capital for speculative purposes can only obtain it by making application to the banks, which, in the very great majority of instances, now refuse to make advances unless tangible securities be deposited to cover their loans. Merchants, therefore, unless their credit be exceptionally good, or unless they possess first-rate stocks and shares, cannot speculate to the same extent as was possible forty years ago and, of course, those persons who possess marketable securities, which bring them in incomes, are the last people in the world to risk an assured position for possible great future gain. They are accustomed to the good things of this earth, and though they may earnestly desire a large accretion to their wealth, the thought that, in the event of failure, they may lose what they already possess, checks the impulse to finance a scheme, which, while holding out promises of great success, is also not without possibilities of grave disaster. As a rule, only small men will take such risks, and the banks will not finance them at any price. By refusing to accommodate weak speculators, the banks have kept business in a healthy channel, and have largely confined speculation to those people who can afford to pay their losses--always a cautious class. The rank speculator, therefore, has been driven to outside houses, and such houses, we know, are constantly failing; but Lombard Street, having weeded this dangerous element out of its system, is now more stable. Recognising that their system of credit is always exposed to possible disaster, and having had the fact brought forcibly home to them upon so many occasions, the banks, since 1866, have gradually accumulated larger and larger cash reserves in order to be better prepared to deal immediately and effectively with those cataclysms which from time to time are certain to assail them; and though it is an open question whether their reserves are even now sufficient, the most casual observer must acknowledge that, with a few exceptions, our banking companies are in a better state of preparedness at the moment than perhaps during any other period of their history. By compelling the schemers to deposit securities against their loans and advances the banks secure themselves against large bad debts; and by accumulating fair cash reserves they insure their business against suspension during panics. Having taken these precautions, it is not surprising that their path has been rendered comparatively smooth during recent years; and, further, the more prudent manner in which the business of a banker is now conducted makes the shares of the large banking companies less speculative holdings, and greatly reduces the risks of shareholders in connection with their liabilities on the uncalled portion of their shares, though that liability should by no means be forgotten or accepted in any other light than that of serious responsibility. This brings us to another point in their history. It was not until 1858 that banks could be registered as limited liability companies, and, needless to say, no unlimited bank has been formed since that date; whilst every joint stock bank now in existence (although, in the great majority of instances, the members are liable for certain known sums on each share held by them) has limited the liability of its shareholders, those companies formed prior to 1858 having since taken the necessary steps. Naturally, persons of wealth would not risk their fortunes by holding shares in an unlimited bank, but now that the exact liability is known the responsibility is accepted with a lighter heart, and, consequently, this class of security is considered a desirable investment by those who can afford to take a little risk in return for higher interest than that yielded by the so-called "gilt-edged" variety of securities. The reader cannot but be struck by the gradual evolution of our banking system; and it must be evident to him that the present more secure position is the outcome of a bitter struggle with adversity. It is usual, when discussing the Bank of England's position in the money market, to degenerate into abuse, and to show that the Old Lady of Threadneedle Street has committed every conceivable folly in dealing with questions of finance. No doubt the accusations are true in the light of past experience. But they were the follies of her times, and, if we are to believe the critics, we are not greatly in advance of our own. Then is it not a little unreasonable to expect the Bank directors of 1825 to be in advance of the financial opinion then current in the City? They had the very best advice of the day at their disposal, and had the present-day critics lived in 1825 they would have urged the Bank directors to take the very course that was then adopted. English history, at a certain period, seems an account of one long struggle between the will of the people and the power of the Crown; and Banking history, prior to 1844, reads like one long struggle between the banks and the Bank of England. But there is this distinction, to wit, the sterling honesty of the Bank. Surely, in the whole world's history there is not another such instance of unbroken faith on the part of a financial institution which has enjoyed a life of more than two hundred years. While anxious to give an accurate account of the Bank's history, and to explain all its faults and all its failings, it is impossible, the closer one examines its actions, not to be the more impressed by its honesty of purpose. Every new movement gropes its way out of the darkness into the light. The process is, however, a slow one; and if, in the future, there are new problems to be solved, then future generations will have to learn the laws affecting them in the school of experience. Despite their increased knowledge, they will probably make the same mistakes as those recorded in these chapters, for it is astonishing, as our environment changes, how short a distance we can see in front of our noses. Banking in 1950 will in all probability be very different to banking in 1902--especially if population increases at its present rate all the world over. CHAPTER III. The Bank's Weekly Return. For the nonce we have finished with history, and will turn our attention to the Bank of England as it now stands in the centre of the Money Market. The joint stock banks publish their balance sheets either annually or half-yearly; but the Bank of England, in compliance with the Act, compiles a weekly statement to the close of business each Wednesday. This Return or Balance Sheet is submitted to the directors on the following day, and, when passed by them, is exhibited on the wall of the Bank to an expectant crowd of messengers and officials, whose business it is either to criticise or copy it. But by far the greater number of the persons there assembled merely wish to know whether any alteration has been made by the directors in the Bank's discount rate, and, that ascertained, the crowd rapidly thins. The following is a copy of the Return or Balance Sheet for the week ended Wednesday, 1st October, 1902:-- ISSUE DEPARTMENT. £ \| £ Notes Issued 51,792,330 \| Government \| Debt 11,015,100 \| Other Securities 7,159,900 \| Gold Coin and \| Bullion 33,617,330 ------------- \| ------------- £51,792,330 \| £51,792,330 ============= \| ============= BANKING DEPARTMENT. Liabilities. \| Assets. £ \| £ Proprietors' \| Government Capital 14,553,000 \| Securities 15,826,080 Rest 3,816,736 \| Other Securities 31,837,516 Public Deposits \| Notes 21,391,145 (Including Exchequer, \| Gold and Silver Savings' Bank, Commissioners \| Coin 2,225,084 of National \| Debt, and Dividend \| accounts) 10,025,973 \| Other Deposits 42,695,526 \| Seven-day and \| other Bills 188,590 \| ------------- \| ------------- £71,279,825 \| £71,279,825 ============= \| ============= A glance at the right hand side of the statement relating to the Issue Department tells us that every note, either in the hands of the public or held in reserve in the Banking Department, is covered by securities and specie deposited in the Issue Department. The amount of the notes in circulation is, of course, obtained by deducting the notes in hand in the Banking Department from the total amount of Notes Issued on the left-hand side of the Issue Department. The difference, £30,401,185, is called the "circulation," and represents the sum which the Bank of England had borrowed from the public on its notes on the 1st October last. Each department is distinct, and has, in fact, a separate existence; so if the Banking Department requires gold, it must, like an ordinary individual, exchange some of its notes in hand at the Issue Department, obtaining therefrom the additional coin to satisfy the demands of its customers in the Banking Department. The Bank has transferred the Government debt and other securities, which together amount to £18,175,000, to the Issue Department, and this sum is called the "authorised issue," for the simple reason that the Government allows the Bank to issue notes for a like amount against these securities, which are mortgaged to the holders of its notes. Gold coin and bullion, we know, must be deposited against every note issued in excess of this sum; and as both sides of the statement agree, it is evident that this has been done. These £51,000,000 of gold and securities, then, are hypothecated to the holders of the Bank's notes, and, in the event of the Bank of England being wound up, the creditors in the Banking Department could not touch either the securities or the gold. But we see that the Bank holds £21,391,145 of its own notes in the Banking Department, and, of course, these notes are secured in the same manner as those held by the public; consequently, this department enjoys similar rights and privileges in respect of them. Add the notes in hand in the Banking Department to the "circulation," and it will be found that the total equals the amount issued. It follows that the Bank only makes a profit on the authorised portion of its note issue, for, as gold is deposited against the remainder, it must lose thereupon to the extent of the cost of production of the notes issued in excess. Obviously, then, the Act does not limit the note issue of the Bank, but it does limit that portion which is not covered by gold, and, consequently, it removes the probability of our seeing Bank of England notes at a discount, as was the case during the early part of the nineteenth century, for the fact that the Bank of England is compelled to redeem its notes in gold on demand prevents depreciation of its paper. Of course, the amount of notes in circulation varies from day to day, and so, too, does the amount of notes issued, which rises and falls as the stock of bullion in the Issue Department is either increased or diminished. Every note paid is immediately cancelled, and no note, after it has been changed at the Bank, ever goes into circulation again. Hence the reason why Bank of England notes present such a marked contrast to the notes of the country bankers, who issue their paper over and over again, until it becomes quite unpleasant to handle, and distinctly malodorous. The Bank of England may be said to perform four separate functions. Its Issue Department, as we have seen, is responsible for the notes. Secondly, the Bank manages the National Debt on behalf of the Government. Thirdly, in consequence of its holding the bankers' reserves, it acts as agent for the Mint. And, fourthly, it conducts an ordinary banking business, but it includes among its customers the largest and most influential depositor and borrower in the Kingdom, to wit, the British Government. The Banking Department, which we will next discuss, stands quite by itself. The first entry on the left-hand side of the balance sheet, we can see, consists of the Bank's capital. Then follows the "rest" or reserve fund, which is never allowed to fall below £3,000,000, the accretions made thereto from time to time representing the profits of the Bank, which are distributed among the stockholders in the shape of dividend after the close of each half-year on the 5th April and the 5th October. The third entry on the statement, Public Deposits, is made up of the various Government balances; and Other Deposits, which form by far the largest debit in the balance sheet, comprise current account and bankers' balances, the latter largely predominating. Since 1877 the Bank has not published the sum standing to the credit of the London bankers in its books; and as this deposit represents the reserve upon which the bankers might have to draw in the event of a panic, it seems an error of judgment not to give publicity to the figures, even if they do show how largely the Bank of England is dependent upon the other banks for its own working resources. Public or Government Deposits and Other Deposits stand in a very peculiar relation to each other, and, before discussing the October return, it is perhaps desirable to illustrate this relation. The fiscal year ends on the 5th April; consequently, the Government is busily engaged in collecting the revenue during January, February, and March. "Other Deposits" are often referred to as the market fund of cash, and as those persons who pay their taxes draw cheques upon their bankers, it follows that during these months huge sums are transferred from the bankers' balances (Other Deposits) to the credit of Public Deposits, which are consequently swollen appreciably. Bankers' balances being reduced, the banks have therefore less to lend; and if the demand for loanable capital is brisk at the time, borrowers are driven to the Bank of England, which sometimes has to raise its rate of discount in order to protect its reserve. Payment of instalments upon Government loans and large issues of Treasury bills produce a like effect. On the 5th October (four days after the date of the return under discussion) a quarterly instalment on the National Debt is due. Then credit flows from Government Deposits back to Other Deposits. The banks can lend freely again, and the Bank of England, in order to attract borrowers, may even have to lower its rates. Undoubtedly, this is a somewhat artificial state of affairs, because money at times is made either cheap or dear, not solely as the result of demand and supply, but partly according to the personality of the holders of the loanable capital when the demand arises. A glance at the return shows us that there is a balance of over £10,000,000 against Government Deposits. This implies that the Bank has control of the money market, that many of the bill brokers, finding Lombard Street empty, have been compelled to borrow from the Bank, which puts on the screw as demands upon its resources increase. Further, rates are not likely to be easier until money is released by the Government. Were the banks to keep their own reserves, and did the Government deposit with three or four of the strongest of them, then this constantly recurring tightness would not occur; but under our one reserve system it is unavoidable. However, it by no means follows that the average rate of discount would be lower under such a system. Indeed, the probability is that it would be much higher, because the banks would be compelled to keep larger reserves, and, consequently, would have less to lend. The last amount on the liability side of the statement is £188,590, which is owing by the Bank on bills in circulation. Shortly after the passing of the Act, and before the joint stock banks had accumulated their vast deposits, the Bank of England issued a much larger volume of these post bills; but since the country banks have been able to draw upon their London agents and head offices in London, the Bank's bills in circulation have gradually dropped from well over £1,000,000 to their present figures. The last three entries, when added together, give us the amount of the Bank's indebtedness to the Government and to the public; and the aggregate, £71,279,825, represents the total liabilities of the Banking Department. But a company, if it be solvent, must possess assets for a like sum, and these we find on the right hand or credit side of the statement. Nearly £16,000,000 are invested in Government securities; and though any advances made to the Government by the Bank on deficiency bills are included therewith, the description is correct, as a loan to the British Government is as safe as Consols. Just before the dividends on the funds fall due the balance in the Exchequer is often insufficient to meet requirements, and it is then that money is borrowed from the Bank of England on deficiency bills. Of course the Bank also advances to the Government for other purposes, and the extent of these loans may be seen in the statement issued by the Chancellor of the Exchequer each week. The next entry on the Assets side, "Other Securities," is extremely misleading, or, at least, it embraces such a wide variety of assets as to make the entry practically useless to all who wish to ascertain the real position of the Bank. Included therein are (1) All the investments of the Bank other than Government securities; (2) Loans to customers and to the Stock Exchange, and bills of exchange discounted for customers and for the bill brokers; (3) The book value of its various premises, unless, of course, its head office and branches have been paid for out of the profits of previous years, on which subject the return does not enlighten us. The balance sheets of some of the minor joint stock banks are disgracefully compiled, but, with respect to this one entry, the Bank of England return runs them very close, and it seems a pity that so powerful a corporation does not set a better example. The Bank, because it holds the bankers' reserves and keeps the Government accounts, is often able to corner the outside market; therefore the least it can do is to issue a plain statement, which will enable the public to see the exact situation created by the unique position it occupies. The return is badly worded, and essential information is certainly withheld, while distinctness is not by any means one of its good points, for nobody, unless he studied the statement with the greatest care, could possibly divine the meaning of some of its quaint, old-world phraseology. But, as we all know, "great men and great things are never in a 'urry"; and the Bank of England, which is great in the best sense of the word, like the Government whose account it keeps, has never been known to anticipate a new development. A pedigree person always swears by the old. But the time has surely arrived when public opinion should compel the directors to issue a fuller and less ambiguous weekly statement. The present form was no doubt a model of lucidity in 1844; but it is woefully behind the times in 1902. The last two entries on the Assets side form the Bank's reserve of legal tender. Strictly speaking, a bank's cash reserve is that sum which it has set aside to meet possible demands of an abnormal character, and as the Bank of England's till-money is included in the two entries in question, the total, £23,616,229, cannot be considered a true reserve, as a certain deduction has first to be made therefrom to provide for the ordinary demands made upon its resources in the usual course of business. Further, the Bank, because it is the bankers' bank, is peculiarly exposed to large drains of specie and notes. It follows, therefore, that to ascertain its true reserve, a very large amount would have to be deducted from the sum in question. A true reserve is a sum set apart for a particular purpose, of which no portion is used in the business it is intended to guarantee. It is a fund apart. Consequently, a banker's real reserve is obtained by deducting from his legal tender in hand the sum he requires for the conduct of his business. The Bank of England, however, needs more till-money than an ordinary banking institution. Glancing at the liability side of the statement, we see that the first two entries represent working capital. In other words, £18,369,736 is a fixed sum, against which it is not necessary to hold one penny in reserve, because no withdrawals can be made therefrom during a time of bad credit. Such an immense amount of working capital makes the Bank of England more independent of its depositors than is the ordinary joint stock bank, and, therefore, its strength as a banking company is increased appreciably thereby, for the weakness of our banking system is due entirely to a fear of possible sudden demands on the part of depositors. Still keeping on the same side, the last three entries give us the Bank's liabilities to the Government and to the public; and as large demands upon this sum of £52,910,089 may be made at any moment, a sum of notes and coin is held in the Banking Department to meet them. This sum, the Bank's so-called reserve, amounts, we know, to £23,616,229, and we next have to ascertain the ratio per cent. it bears to the liabilities in question. The following sum will supply the answer: (£23,616,229 × 100) / (£52,910,089) = £44·6% The Bank, then, on 1st October last, held £44·6 in notes and specie in the Banking Department to meet each £100 it owed to its customers. Yet we say "as safe as the Bank of England," when, as a matter of fact, the Bank could not pay its debts on demand; and, paradoxical as it may seem, so the Bank _is_ safe, because its credit is so good that no man in England would ever dream of questioning its stability, for, if he did, he would only be laughed at for his pains. Again, comparatively speaking, the Bank of England is certainly safer than its rivals, and when we consider, in so far as its customers are concerned, the huge amount of its capital and reserve, it is evident that it is by far the safest bank in the land for depositors, as the larger the capital of a bank the greater is the guarantee of the customer against loss. We have seen that the notes and coin in the Banking Department work out at a ratio per cent. of 44·6 to deposits; but as notes are not legal tender by the Bank of England, its creditors can refuse to accept them in discharge of a debt. This £21,391,145 of notes might, however, have been exchanged for gold with the Issue Department at any moment, so that the Bank could have paid off 44·6 per cent. of its liabilities on the day in question--a huge proportion. It may be objected that, as a certain portion of its gold is held in bars, which would have to be sent to the Mint for coinage, the Bank could not discharge its debts quite so rapidly, and the contention would be perfectly true. But, assuming this exchange were made, £12,226,185 in gold would remain in the Issue Department to meet £30,401,185 of notes in circulation. The Bank, of course, could not then pay one half of its notes were they presented; but such a demand is almost outside the bounds of probability. Still, it is one of those extremely remote possibilities which no prudent Board of Directors can afford to forget; and we may be quite sure that this fact has not been overlooked by the Bank, which can always protect its gold by raising its discount rate. In the next chapter another view will be taken of the Bank of England's weekly balance sheet. CHAPTER IV. The Issue and Banking Departments Combined. In the preceding chapter the Issue and Banking Departments of the Bank of England have been discussed separately. Strictly speaking they can, of course, only be so treated, as each division stands alone; yet the notes in the Banking Department undoubtedly form a connecting link between the two divisions, seeing that they make the one department by far the largest single creditor of the other. Therefore it is intended in this chapter to discuss the return as a whole, to place the totals in the Issue Department back in the Banking Department, and to ascertain the Bank's exact state of preparedness to meet all its liabilities. The following table will enable us to do this: ISSUE AND BANKING DEPARTMENTS. £ \| £ Capital 14,553,000 \|Specie and Bullion 35,842,414 Rest or Reserve Fund 3,816,736 \|Government Debt 11,015,100 Notes in Circulation 30,401,185 \|Other Securities 7,159,900 Public Deposits 10,025,973 \|Government Securities 15,826,080 Other Deposits 42,695,526 \|Loans, Bills Discounted, Seven-Day Bills 188,590 \| Securities, etc. 31,837,516 ----------- \| ----------- £101,681,010 \| £101,681,010 =========== \| =========== _1st October, 1902._ ============+============+=======+============+ \| Ratio % of \| \| \| Ratio % of \|Investments \|Total \|Ratio % of \| Specie and \| and \|Liquid \|Capital to \| Bullion to \|Government \|Assets.\|Liabilities.\| Liabilities.\| Debt to \| \| \| \|Liabilities.\| \| \| ------------+------------+-------+------------+ \| \| \| \| 43·02 \| 40·81 \| 83·83 \| 17·46 \| \| \| \| \| ============+============+=======+============+ ============+========+=============+ \| \| Ratio % of \| Ratio % of \| Total \| Loans, \| Rest to \|Working \|Bills, etc., \| Liabilities.\|Capital.\| to \| \| \|Liabilities. \| \| \| \| ------------+--------+-------------+ \| \| \| 4·58 \| 22·04 \| 38·21 \| \| \| \| ============+========+=============+ It may be urged that as the gold and securities in the Issue Department are mortgaged to the holders of Bank of England notes, they cannot be treated as ordinary assets, and that is true enough; but when we remember that upon the day in question the Banking Department could have exchanged notes to the value of £21,000,000 for gold, the objection loses much of its force. However, assuming the Banking Department made the exchange, then specie to the extent of over £12,000,000 and the second and third items on the right-hand side of the balance sheet would be mortgaged to the holders of the notes in circulation, and the Bank, were it in need, could legally neither sell the securities nor apply the £12,000,000 in question to the liquidation of any other debt. But, practically, there is small likelihood of the Bank of England being drained of specie by its notes, which have always been accepted without demur, even during the most troublous years of its history; and, while remembering that the notes in circulation are secured in the manner aforesaid, we may safely consider the Bank's state of preparedness to meet its total public indebtedness from the point of view that its liquid assets would be more than sufficient to discharge all probable demands made by both holders of notes and depositors. On the 1st October last the Bank owed on its Notes in Circulation, Public and Other Deposits, and Bills, the huge sum of £83,311,274, which we will call its "Liabilities to the Public." Against this it held £35,842,414 in specie and bullion, which, a glance at the table shows, works out at a ratio per cent. of 43·02. The Bank had, then, £43·02 of the precious metals in hand to meet each £100 it owed to its customers. There is not another bank in the kingdom able to publish a balance sheet showing such a splendid proportion of cash in hand to liabilities--but we must also remember that there is not another bank in the country whose responsibilities are so great and so multifarious. In the previous chapter it was shown that the Banking Department possessed £44·6 in notes and coin to meet each £100 of the public liabilities included therein, and, moreover, this would be the ratio given by the critics; but we now see that, when the two departments are united, the ratio only works out at £43·02. Strictly speaking, the larger ratio is correct; yet the smaller gives a much truer idea of the Bank's ability to pay off its creditors in cash on demand. Further, as the Bank cannot compel its customers to accept its own notes in discharge of a debt, the ratio £43·02 certainly gives one a more accurate impression of the Bank's position in relation to all its creditors. The Government Debt, Other Securities, and Government Securities amount to £34,001,080, which works out at a ratio per cent. to liabilities of £40·81, making the ratio of total liquid assets £83·83. A debt owing by the British Government is rightly included with the liquid assets of the Bank, for when the credit of the Government ebbs our banking companies, which hold huge amounts of Consols, will no longer be solvent institutions; but no reasonable man imagines that an edifice which has been centuries in building, and which is still far from being either complete or perfect, will "go under" in a day, though all know that it cannot last for ever in its present form. We, however, only live sixty years or so, and therefore each generation of business men considers what will last out its time, and troubles itself but little about what the state of commerce will be fifty years later, as though dimly conscious that, in the end, man will have to go back to the land. The Bank, we see, possesses £83·83 in cash and the very best securities to meet each £100 it owes to the public. Such figures cannot fail to impress one, for they prove indisputably that, on its merits, the Bank of England is by far the strongest banking company in the three kingdoms. They should not, however, blind our eyes to the fact that the Bank is a credit institution, and that were its creditors to go for gold in a body it would inevitably "smash," for, as we can see from the figures in the first column of the table on page 49, it never keeps a supply of the precious metals equal to its liabilities on demand. But, for all that, the Bank is splendidly prepared to meet every probable demand; and one cannot ask more of its directors. It would be easy enough to write an indictment against the Bank, proving that its policy is all wrong, that it could not discharge its obligations under certain given conditions, and that, therefore, it is a menace to the solvency of the country. But such deductions, which have already been made by more than one critic, are crass nonsense, and only testify to the critics' ignorance of the subject. We know that the Bank's system is not by any means a perfect one, but, surely, the person who advertises an infallible financial system is either a great rogue or a great simpleton; for why is he not himself rich beyond desire? The Bank of England, it is admitted, cannot meet its liabilities on demand, and most people would think that its directors had gone mad if they prepared to, while the stockholders would certainly threaten to turn out those directors who proposed a policy which would reduce the value of their stock considerably below parity. The question seems to be: Is the Bank of England sufficiently prepared to meet all likely withdrawals of gold by its customers and by the holders of its notes? The two columns, which give us the amount of the Bank's liquid assets, tell us plainly enough that the Bank of England was well prepared on the 1st October. We can see that it held a good supply of coin and bullion, and, secondly, a valuable list of convertible securities; but as the securities are only convertible so long as the Bank, which holds the reserves of cash of all the banks in the United Kingdom, is in a position to meet all probable demands upon its store of gold, it is evident that the first ratio is of paramount importance. The Bank of England, which possesses the only large store of the precious metals in this country, has to meet both the home and foreign demands for gold. It follows, therefore, that its ratio per cent. of Reserve to Liabilities is eagerly scrutinised each week on the publication of the return, because it indicates whether or not loanable capital is likely to be dear or cheap. The means at its disposal for maintaining an adequate supply in reserve will be discussed later on. Should the said ratio fall below, say, forty per cent., then it is prudent to inquire the reason; and should it recede to, say, thirty-three or thirty-four per cent., then there may be cause even for apprehension; but so long as the Bank of England keeps a fair ratio of reserve to its public indebtedness, there is no cause for alarm: though a bank which holds the national reserve must always be extremely cautious, even when credit is good and there is not a breath of suspicion in the air, for the proverbial little cloud gathers strength with incredible speed when once it does appear. Undoubtedly our banking system is exposed to the gravest dangers, but as it brings us cheap money we accept the risks; and unless a critic can produce a workable scheme which will eliminate the hazard and retain the blessing of cheap loanable capital, he had better by far confine his attention to those safeguards that reduce the risks of our present system, which _is_ workable, to a minimum. Provided the Bank of England keeps an adequate reserve in the Banking Department, we have at least the satisfaction of knowing that all that can reasonably be done to ensure safety has been done, and that those risks, which a credit bank cannot avoid under any system, have at least been insured against under our own. No doubt the Bank's large working capital of over £17,500,000 has contributed very considerably to its ascendancy, and helped it, especially since 1844, to more than hold its own against all comers; for despite the fact that we occasionally hear sneers--no doubt prompted by jealousy--at its so-styled omnipotence, an examination of its return soon convinces the sceptical that it is still the largest and safest bank in England. Further, it has occupied this enviable position for over two hundred years. The ratio per cent. of Advances (loans, bills discounted, securities, &c.) to Liabilities is only 38·21--a proportion, especially when it is remembered that an unknown amount of investments is included therewith, which clearly informs us that the Bank is fully alive to the responsibilities of its unique position, and that its directors, while they are no doubt anxious to make as much net profit as possible for the proprietors, have not lost sight of the fact that they also have duties to perform towards the public. But it must not be thought that the directors discharge their duties towards the public so well from philanthropic motives. Even from a selfish standpoint it pays them to keep the Bank thoroughly prepared, as, should they allow the reserve to sink too low, an anxious period would be certain to follow, when additional profits, made by trading with too large a proportion of the deposits, would speedily be swept away by the expense incurred by borrowing back at high rates in order to strengthen the cash in hand. For a little while the interest upon the increased loans would swell the profits, but directly the foreign exchanges moved against this country, and gold began to flow abroad, even an inexperienced director would realise the folly of risking a panic for the sake of seeing the dividends rise, and he would not make such a doubtful experiment a second time. Perhaps, before bringing this chapter to a close, it may be interesting to compare the total indebtedness of the Bank of England to the public and its stockholders with that of Lloyds and the National Provincial Bank of England to their customers and shareholders. The following table will supply the figures:-- ======================================================== Name of Bank. \| Total Liabilities. ------------------------------------+------------------- \| £ Bank of England \| 101,681,010 Lloyds \| 58,411,041[A] National Provincial Bank of England \| 56,444,126[A] ------------------------------------+------------------- [Footnote A: Balance Sheet dated 31st December, 1901.] ======================================================== We can now see how much larger are the working resources of the Bank of England than those of either of the other above-mentioned banking institutions, though, as the joint stock banks keep their reserves of cash with the Bank of England, the comparison loses a little of its force. Still, the preponderance of the Bank of England is most marked, a fact one is not, perhaps, so apt to realise when the Issue and Banking Departments are considered apart. CHAPTER V. The Store in the Issue Department. We next have to consider the amount of gold coin and bullion in the Issue Department--to wit, £33,617,330, and we must remember that this accumulation is the national store, that the cash reserves of all the banks in England, Scotland, and Ireland are dependent thereupon, and that, consequently, the solvency of the nation is decided thereby. The indebtedness of the English, Scotch, and Irish Banks to the public at December, 1901, as shown by their balance sheets, upon current accounts, deposit receipts, and notes in circulation, amounted to nearly £910,000,000. The liabilities of the Bank of England and of those private bankers who publish balance sheets are included in this huge total. This £910,000,000 may be called the "floating capital" of the country. It is deposited or left with the banks, who invest a certain proportion of it in securities, in short loans to the bill brokers and stockbrokers, in making advances and loans to their customers, and in discounting bills for them; and, as the said millions are left at either call or short notice, the banks also have to maintain a sufficient supply of legal tender to meet all probable demands upon this immense debt. It is with this "floating capital" that the present chapter is principally concerned. Stored in their strong rooms the banks keep sufficient legal tender (Bank of England notes and specie) with which to conduct their business. The sum thus held may be called their "till money"; and it probably would not exceed five per cent. of the £910,000,000 in question--viz.: £45,500,000. A large part of this till money is, however, held in Bank of England notes, which are warrants for gold upon the store in the Issue Department, but as creditors cannot refuse the notes they are quite as valuable to a banker as gold. All a banker has to consider is whether he has a sufficient supply of legal tender to discharge his public indebtedness; and if he have, he need take no thought for the morrow. Deducting £45,500,000 from £910,000,000, we get £864,500,000. Though this is an accumulation of credit in the books of the banks rather than of cash, their customers can demand the equivalent from them in legal tender; yet we see that, were the banks drained of £45,500,000, they would then be entirely dependent upon their reserves at the Bank of England. The reserves are included in Other Deposits, £42,695,526; and seeing the magnitude of the amount it seems a pity that the Bank of England does not tell us each week what portion of this total belongs to the other banks. Further, the Bank of England employs these balances in its own business; and, though it generally maintains a very large ratio per cent. of reserve to liabilities, the fact remains that a certain proportion of the cash reserves of our banks is lent out to the public--a somewhat startling position at first sight. The banks accumulate a reserve against those dangers from which their business is never free, and the Bank of England advances some of it to its own customers! Apparently, what could be more absurd? But in finance things are so often not what they seem. We now come to the store of gold coin and bullion in the Issue Department--£33,617,330. A certain proportion of this must be retained in order to secure the convertibility of the notes of the Bank, and the remainder may perhaps be called the national store or accumulation. The banks of the United Kingdom are indebted, roughly speaking, to the public to the extent of £910,000,000. But we have seen that, say, £45,500,000 of this sum is secured by legal tender in hand, so the unsecured portion amounts to £864,500,000. Our position, then, stands as under:-- Indebtedness of the Banks of the United Kingdom to the public £910,000,000 _Less_ covered by legal tender (say) 45,500,000 ------------ £864,500,000 Gold and bullion at the Bank of England £35,800,000 As a matter of fact, we are looking on the bright side of the picture, for seeing that a large amount in Bank notes would be held among the £45,500,000 deducted, it follows that the store in the Issue Department might be appreciably reduced were a considerable number of these notes presented for payment; and then again, the indebtedness of those private bankers who do not publish balance sheets has been omitted. Suppose we say that the banks hold £35,500,000 in specie. This, added to the store at the Bank, gives us £71,300,000. Then our banks owe £910,000,000; but there is only £71,000,000 of specie in their possession with which to pay their huge debt. On the other hand, many of the banks do not hold nearly five per cent. of their liabilities to the public in legal tender on their premises; and, were the truth known, it is more than probable that in some instances three-and-a-half to four-and-a-half per cent. would be nearer the mark. England, after all, is only a gigantic workshop, and so long as her shops are busy there is no danger. But have those people who live on incomes invested solely in British securities ever reflected that, were there no work for her shops, this system of credit would collapse like a castle of cards, when their incomes would be gone? Our solvency as a nation depends absolutely upon the skill and ability displayed by British manufacturers, and upon the muscles and intelligence of their workmen. Given a high standard of efficiency and adaptability on the part of our producers, then trade flows to this country, and by trade alone can we support our credit and pay our debts. Small wonder, then, that thoughtful people are becoming alarmed at the apotheosis of Games in this country, and at the large number of idlers who do not take a part in production, but are dependent upon the interest received from investments, which can only be productive so long as our commerce is flourishing. The capital of this country has been computed by a competent authority at about £10,500,000,000, but doubtless these figures are very wide of the mark. Still, the amount of fixed capital invested in the country must be immense. By "fixed" capital, as distinguished from the floating or loanable capital deposited with the banks and kindred institutions, those investments of a more permanent character are implied. A depositor can demand his money back from his banker, but bank shares he would have to sell on the Stock Exchange--therefore the one is "floating" and the other "fixed" capital. It is the same with Consols, railway shares, and with the shares of all companies in which there is a market. When there is not a market, then the capital is fixed indeed; and there would not even be a market for Consols were the Bank of England drained of its gold. Moreover, during normal times the demand for loanable capital at the banks will help to determine the price an investor will receive should he desire to sell any of his fixed investments. It consequently amounts to this: The fixed capital of the country cannot be converted or sold unless the banks maintain large cash reserves; so we may truthfully assert that about £10,000,000,000 of capital is erected on a basis of about £71,000,000 of cash. This cash, in its turn, can only be kept in the country while our workshops are busy; therefore it at once becomes apparent that the national aim should be to increase our trade, for the yield, and consequently the value, of British securities is bound to either increase or diminish in proportion as the trade of the country is either flourishing or the reverse. Even the Government can only meet the interest on Consols while the people are in a position to pay their taxes. Such a statement may come as a shock to those persons who are accustomed to draw their dividends each half-year or year, and to imagine that unless the world came to an end these dividends could not cease; but they would cease were this country to fall hopelessly behind in the race for trade. This is not the old Socialist maxim that "Labour supports the world" put into a new print dress. It is evident that the fixed capital of this country, as represented by stocks and shares, would be mere waste paper unless the banks held sufficient gold to ensure a market for them: and as this gold cannot be kept in the country unless our workshops are able to compete successfully with those of other nations, it follows that the position of those persons who draw incomes from British securities is entirely dependent upon the brains and abilities of the men who direct our industries. How important, then, that the very best talent the nation possesses should be used in trade; and what folly it is on the part of those so-called "superior" persons to sneer at the trader--at him who, without doubt, enables them to draw their incomes regularly! There was a time when capital, broadly speaking, could only be obtained in London; but since then population has increased all the world over, and as capital is only the savings of labour, it naturally follows that it can now be obtained abroad, and that London is less necessary to the foreign borrower; and, as the world fills up, it must surely become less and less necessary. Yet our gilded youth affects to despise trade. This is somewhat absurd, when it is trade that enables him to live in idleness; and British pride, unless it recognises this fact, may have a bad fall. The banks of the United Kingdom, roughly speaking, are indebted to the public to the extent of £910,000,000. They only keep till-money in their safes, and are dependent upon the store in the Issue Department of the Bank of England for their reserves of cash. In other words, this £33,000,000 of specie is the foundation stone upon which £910,000,000 of credit rests. It has already been shown in what relation the fixed capital of the country stands to this fund. The smaller of the provincial banking companies keep their cash reserves with their London agents, who also place their reserves with the Bank of England. Consequently, as the agents include the reserves of these banks with their own deposits, they, like the Bank of England in relation to the bankers' balances, lend out a percentage of the reserves of the smaller banks. It follows, therefore, that the bankers' balances in the hands of the Bank are smaller than would be the case if each bank kept its reserve with it. The London agents are dependent upon the Bank, and the smaller banks upon the agents. As the store in the Issue Department is the only large collection of specie and bullion in the three kingdoms, and as the amount therein is always extremely small when compared with the huge liabilities which, under certain conditions, it might be asked to liquidate, any considerable depletion of this store makes the owners of large bank balances nervous; for if the Bank of England cannot pay the bankers, then their bankers will not be able to pay them. Again, the liabilities of the banks are so immense in comparison with their reserves that a very small diminution of the fund in the Issue Department makes owners of capital anxious, whilst a serious drain would probably create a panic; and unless means were devised to allay the panic, it might develop into a revolution; for we are very commercial in these days, and are beginning to realise that mere glory may be bought too dearly. Commercialism, however, is not exactly a fascinating virtue. We are constantly being told that the money market is an extremely sensitive organisation. And no wonder! The banks owe hundreds of millions on demand and short notice. Considerably over eighty per cent. of these millions is invested and lent, and as the banks' reserves of gold are small, every sudden demand for large supplies of the precious metals is liable to disorganise the market; and the Bank, which holds the final reserve, is therefore compelled to raise its rate of discount in order to protect the bullion in its Issue Department. But for this very reason capital may generally be borrowed more cheaply in London than elsewhere; and though cash is perhaps dangerously economised, credit is proportionately the more easily obtainable, and the price of a loan is cheaper than would be the case were the banks to maintain a higher ratio of cash to liabilities. They would then have less to lend, and in times when trade was brisk demand would drive up the rate of interest to higher figures than those which prevail under our present system, and reduce the profits of borrowers. The average rate, too, would be greater. The dangers of our system are very apparent, but so are its advantages; and though we consider it pays us to take the risks, it is evident that we cannot afford to neglect the necessary precautions. CHAPTER VI. Weekly Differences in the Return. It were better, before proceeding further, to give a copy of the Bank Return as it appears in the daily papers each Friday, when comparisons are made with the figures of the preceding week, and the various differences carried into distinctive columns. That for the week ended Wednesday, 1st October, 1902, has been selected, in order that the figures may be the same throughout this volume. The statement is given below: Issue Department. ========================================================================= 2 Oct., \| \| 24 Sept. \| 1 Oct., \|Increase.\|Decrease. 1901. \| \| 1902. \| 1902. \| \| -----------+-----------------+-----------+-----------+---------+--------- £ \| £ \| £ \| £ \| £ \| £ 36,080,595\| Gold and Bullion\| 35,109,950\| 33,617,330\| ... \|1,492,620 53,855,595\| Notes Issued \| 53,284,950\| 51,792,330\| ... \|1,492,620 30,546,875\| Circulation \| 29,198,845\| 30,401,185\|1,202,340\| ========================================================================= Banking Department. ========================================================================== 2 Oct., \| \| 24 Sept.,\| 1 Oct., \|Increase. \|Decrease. 1901. \| \| 1902. \| 1902. \| \| ---------+---------------------+----------+----------+----------+--------- £ \| Liabilities. \| £ \| £ \| £ \| £ \| \| \| \| \| 3,790,617\|Rest \| 3,804,611\| 3,816,736\| 12,125\| ... 10,874,581\|Public Deposits \| 8,301,490\|10,025,973\| 1,724,483\| ... 41,204,129\|Other Deposits \|40,373,382\|42,695,526\| 2,322,144\| ... 143,965\|Seven-Day Bills \| 192,886\| 188,590\| \| 4,296 ---------+---------------------+----------+----------+ \| £ \| Assets. \| £ \| £ \|Decrease. \|Increase. \| \| \| \| \| 8,022,103\|Government Securities\|14,594,260\|15,826,080\| ... \| 1,231,820 7,158,440\|Other Securities \|26,302,606\|31,837,516\| ... \| 5,534,910 3,308,720\|Notes \|24,086,105\|21,391,145\| 2,694,960\| 2,077,029\|Gold and Silver \| 2,242,398\|2,225,084 \| 17,314\| \| \| \| +----------+---------- \| \| \| \|£6,771,026\|£6,771,026 48⅝% \|Ratio \| 53·87% \| 44·6% \| 3% \|Bank Rate \| 3% \| 4% \| =========================================================================== Why, it may be asked, is so much importance attached to this return, and why do the critics, each week, endeavour to state precisely how much the "market" has borrowed from, or repaid to, the Bank, and to explain the cause of the various accretions and diminutions in the different assets and liabilities? With regard to the latter attempt, each critic, it is said, is quite convinced that he alone understands the true inwardness of the various movements which result in the increases and decreases recorded in our table; but it is just whispered that those persons at the Bank of England who _know_ the cause laugh at their deductions. The return is of the greatest moment to the public, for the simple reason that it shows the ratio per cent. of the Bank's reserve of notes and cash in hand to its liabilities, and, also, the amount of coin and bullion in the Issue Department. The Bank holds the final reserve; and if demand is brisk and the other bankers have advanced largely to the outside market, the bill brokers are driven to the Bank. As the banking companies have advanced all their spare capital, demand can only be supplied from the reserve at the Bank of England; and the Bank, which must protect its gold, checks demand by charging high rates to all who borrow. The return, then, tells us whether loanable capital is likely to be cheap or dear. If the ratio to liabilities be small, and the store of gold diminishing, we know that demand has reached the Bank, and that money will be dear. When money is dear, Consols and other so-called gilt-edged securities are almost certain to fall in value. If it become really scarce, then the banks, which lend huge sums on the Stock Exchange, charge the brokers enhanced rates, and "carrying over" becomes difficult. Numerous speculative accounts have to be closed, and securities, consequently, fall in price. Now, a glance at the return of 1st October, 1902, shows that the ratio on that date is 44·6 per cent., and the Bank's discount rate four per cent. The bullion in the Issue Department decreased £1,492,620, and the Bank, in order to arrest this drain, raised the rate from three to four per cent. The political unrest in France, which at first threatened to disturb the London money market, and the tightness of money in New York, were, undoubtedly, two factors which largely influenced the decision of the directors, who, no doubt, also took into their consideration the fact that the autumn demand for currency might further reduce their reserve. Noticing that Consols were at 93⅛, and believing that the stringency was only temporary, one might feel disposed to buy, trusting that cheaper money during the earlier part of the new year would drive them up to 96 or so. The weekly return of the Bank of England, then, is the barometer which tells us whether loanable capital is either scarce or abundant, dear or cheap; and, when read with the Board of Trade returns and the foreign exchanges, it enables us to guess, with more or less _uncertainty_, but still intelligently, and with a degree of probability, whether or not money is likely to be in future demand. The Railway and Bankers' Clearing House returns, too, indicate the course of trade, and are of more than academic interest. It is, however, always wise to remember that finance is not an exact science, for if it were the theorists would be fabulously rich; and we know that they are generally so hard up as to be compelled to write books and financial articles for a living. Now we can see why the Bank of England's weekly balance sheet is keenly interesting to every person who possesses capital either to lend or to invest, to dealers in bills and securities, and to every speculator on the Stock Exchange, as a strong or a weak return may make all the difference to the rates charged on "contango" day. Borrowers and lenders are equally concerned, for the rate of interest does not depend upon the caprice of any individual or of any bank, but is solely the outcome or result of demand and supply; and demand, when the banks have exhausted their supplies of spare capital, then centres itself fiercely upon the Old Lady of Threadneedle Street simply because she holds the final reserve of cash, and for no other reason whatsoever. Reverting to our statement, we find that the increases and decreases of the various totals balance each other; and if the differences agree, then the assets and liabilities, on adding the Bank's capital of £14,553,000 to the latter, must also balance each other, for the simple reason that the Bank keeps its books by double entry. The best system of bookkeeping which can possibly be adopted is the simplest system, because the very fact of accounts being complex and involved is sure to result in a multiplicity of mistakes, which prove that the system is faulty. In double entry there must be a debit for every credit; so every sum debited to one account in the books of the Bank of England is credited to another or to others; and as the assets and liabilities in the statement tally, therefore the balances in the last two columns, which are the result of multitudinous debits and credits made during the week, must agree also. But how is it possible for an outsider to follow these internal movements? He simply cannot. Consequently his deductions made from the differences shown week by week are sometimes very wide of the mark, and, for his own reputation's sake, it would be wiser if he were to confine his remarks principally to the all-important questions of the ratio in the Banking Department and the bullion in the Issue Department. For instance, simply with the differences in question to go upon, it may be said that the return shows that the market has borrowed largely from the Bank, "Other Securities" being up over £5,000,000. Part of this amount increased "Other Deposits," and a transfer was also made to "Public Deposits" in order to pay the Government for £2,000,000 of Treasury bills, while the accretion to "Government Securities" seems to indicate that the Government borrowed a certain sum from the Bank on Ways and Means, and that loans were made to the market on this class of security. In London the "loan account" system is greatly in evidence among the banks. That is to say, when a customer is granted a loan for, say, £10,000, his current account is credited £10,000, and a loan account, opened in his name, is debited £10,000. The interest is calculated upon the loan account, and the advantage resulting to the banks is too evident to call for explanation in these pages. When loans are made by the Bank of England, accounts which increase "Other Securities" are debited, and other accounts, which increase "Other Deposits" are credited--if the loans are made to the public. Should the loans be made to the Government, "Public Deposits" and "Government Securities" also increase proportionately from the same cause. The Bank, because it keeps the bankers' accounts, occupies a peculiar position in relation to these entries, and that position will be discussed in a later chapter. The notes in the Banking Department have decreased £2,694,960 and the specie £17,314, so, if we add these two sums together, the total, £2,712,274, represents the diminution in the reserve. A glance at the Bank's liabilities shows us that they have increased appreciably, and as the reserve has shrunk considerably, it follows that the ratio is very much smaller than that of the previous week. Indeed, the reserve had not fallen so low since May; and the monetary outlook being uncertain, the directors, as a precautionary measure, raised the rate of discount. Next, suppose that we wish to ascertain the amount of cash which has been withdrawn from the Bank to meet the demand within the country. The bullion in the Issue Department is £1,492,620 down, and the coin in the Banking Department £17,314; so the Bank has lost £1,509,934 in coin and bullion. But £730,000 was exported during the week; therefore, if we deduct £730,000 from £1,509,934, the difference, £779,934, is the amount that is gone into home circulation. But, it may be asked, how can one ascertain the amounts of the exports and imports of the precious metals? Late in the afternoon of each day the Bank exhibits a statement on its walls giving this information, and it was from these placards that it was ascertained that the sum in question had been sent abroad. Hence it is possible to learn how much cash was withdrawn from the Bank for home requirements during the week, or, better, the amount of the efflux on the day of the publication of the return. But, as has already been explained, these deductions are not always reliable. CHAPTER VII. The Bank of England as Agent of the Mint. In theory any person can take gold bullion to the Mint, which, under the Coinage Act, is compelled to give him in exchange sovereigns containing an equal quantity of gold to that left; but nobody ever does, and practically the Bank of England acts as the Mint's agent. By the Bank Act he receives £3 17s. 9d. per ounce, instead of £3 17s. 10½d., the full Mint price, the deduction of 1½d. being about equal to the loss of interest incurred, for the Mint does not bargain to pay out coin immediately on delivery of bullion. All the bankers in the United Kingdom, we know, obtain their supplies of cash from the Issue Department of the Bank of England, which, as a natural consequence, supplies the currency requirements of the nation. Possessing the only large store of bullion, it can, so to speak, feel the pulse of the whole trading community; and, directly a demand sets in for specie, it sends bullion to the Mint for conversion into coin. This it can do without any loss of interest whatever, for, of course, the bullion is lying idle in the Issue Department. A bank which keeps the Government accounts, and stands in this relation to the other bankers, must of necessity become the agent of the Mint, which, even in its output of silver and bronze coins, relies absolutely upon information received from the Bank of England. The Bank, in fact, supplies both the London and country bankers with these token coins. As an illustration of this one of those little social amenities which take place between bankers and their clients about Christmas time may be mentioned. Naturally I am not alluding to the higgling occasioned by the increase of advances and bills discounted to meet a growing demand at this period of the year. But many persons, just before the festive season sets in, like to obtain supplies of bright new silver coins with which to anoint the palms of their humbler fellow-subjects, whose manners about that time become aggressively pleasant and ingratiating. These coins they get from their bankers, who receive them from the Bank of England and its branches, either directly or through their agents. As soon as the bankers run short of silver coins, they apply to the Bank, which, being in close touch with every source of demand, is able to guide the Mint on a question of supply. The Bank of England does not possess a legal monopoly, but occupies this position solely because it holds the final reserve of cash. If the Government and all the bankers keep accounts with the Bank of England, then the Bank must act as the agent of the Mint so long as this state of affairs continues, because its Issue Department has to meet all demands for cash made upon it by the Bank's customers and the holders of its notes; and as these customers, either directly or indirectly, include every large dealer in gold in the land, it supplies the currency as a matter of course. Dealers do not send their bullion to the Mint, because it is more convenient to sell it outright to the Bank, which settles with them immediately, thereby removing all uncertainty as to the length of time coinage will occupy. It follows, therefore, that the Bank of England has to meet all demands for gold, whether for home or foreign requirement; but it is when gold is leaving the country in large quantities that drastic measures have to be taken in order to stop the depletion of the Bank's reserve of the precious metals, for some of the home drains are only of a temporary nature, and unless capital be greatly in demand at the time they do not affect the rate of interest, as the money flows back to the Bank after a short interval. The Bank of England on 5th January, 5th April, 5th July, and 5th October pays the quarterly dividends on the National Debt. The Government, which at the present time has to provide over £6,000,000 each quarter, has a huge sum standing to its credit before one of these payments matures, and the sudden release of so much capital often causes the rate of discount to fall, especially during those years when trade is good, and the demand for loanable capital consequently brisk. If times are dull, then the rate will not ascend when the Government is taking money off the market, as the demand upon the reduced resources of the banks will not be sufficiently keen to drive a large number of borrowers to the Bank of England. We have an illustration of this in the fact that from February, 1894, to September, 1896, trade was so inactive, and demand therefore so small, that the Bank rate stood at two per cent. during the whole period. In other words, we had two and a half years with the Bank rate at two per cent. With trade bad and money cheap, speculation soon became rampant. The gilt-edged variety of securities yielded less, because trade was less productive, and consequently capital, instead of being kept idle in the banks, was transferred to the better class securities, which returned less to the investor in proportion as increased demand forced up prices. With incomes reduced and balances lying idle at the banks, the public developed a speculative mania, and one result was the Stock Exchange boom of 1895, for investment business and speculation always increase when trade is bad. Bad times, in fact, at first add to the business of the House. Traders keep large balances with the banks for the same reason that the banks themselves have huge sums standing to their credit in the books of the Bank of England, because they are bound to accumulate credit in order to meet their engagements, and, also, to maintain a surplus in case of accidents, such as bad debts and the inability of customers to pay their debts immediately on maturity. When trade slackens and prices fall, producers reduce their output, and the result is an accumulation of credit in the books of the banks. Moreover, a certain proportion of these balances is not then required to finance and guarantee commercial undertakings. Hence the movement to which attention has already been drawn. But the holders of gilt-edged securities require some inducement in order to persuade them to sell; and this is forthcoming in the shape of accretions to the capital value of their stocks and shares as a result of the increased demand. But the floating capital of the country is not decreased by this exchange. It is left at precisely the same figures. The buyers draw cheques upon their bankers, and the sellers pay the same cheques to their own credit; consequently, the floating capital in the hands of the banks is always about the same, be the times good or bad, so long as speculation or investment is confined to British securities. When, however, foreign securities are purchased, gold sometimes has to be sent out of the country to help pay for them; and it is then that the situation may cause apprehension--for capital is leaving the country. Should the drain prove serious, the Bank would have to raise its rate; and were it to prove continuous, notwithstanding an abnormally high Bank rate, we might have a crisis. Returning to the dividends on the funds, "Public Deposits" are increased before the above-mentioned dates, and when this money is released, the result is a large addition to "Other Deposits," because most of the money returns to increase the bankers' balances. A small part, however, is taken by the fund-holders in cash; so we may notice a decrease in the Bank's reserve of notes, and, consequently, an increase in the circulation, together, perhaps, with a fall in the bullion, representing the small proportion withdrawn in actual cash. Should the banks, in consequence of this increase in their deposits, be taking bills from the brokers at cheaper rates, then "Other Securities" would also lessen, because the bill brokers would pay off the Bank and borrow in the cheaper market. The converse occurs when the Government is collecting the revenue, issuing a new loan, or borrowing on Treasury bills. The principal currency drains will be discussed in the following chapter. CHAPTER VIII. The Principal Currency Drains. The principal currency drains occur during the holiday season and at harvest time, more especially during the latter period, when large amounts of cash are sent into the country to satisfy the requirements of labour. Early in November a demand for gold arises in Scotland, owing to the fact that rents there fall due at Martinmas (11th November); and as the Scotch banks, by the Act of 1845, are compelled to hold gold against notes circulated in excess of their authorised issues, a rather heavy call is made upon the Bank of England, whose returns then show a noticeable decrease in the reserve and bullion. During years of active trade, and, consequently, of brisk demand for loanable capital, these autumnal drains of gold generally force up the rate of interest, thereby making the last quarter of the year the dearest for borrowers. But we are discussing internal demands only, and as, so long as gold does not leave the country, it is merely a question of certain sums flowing from the London money market and drifting back to it again, this ebb and flow, which is shown by the various ups and downs occurring from time to time in the items of the Bank return, does not create any apprehension. Indeed, these movements occur so regularly at certain times of the year that large borrowers often anticipate them in order that they may tide over such periods with the minimum of inconvenience. It is, however, otherwise when gold is leaving the country in large quantities in order to settle the balance of our indebtedness to other nations, for that _may_ not come back. How it is again enticed to these shores I will endeavour to explain. We now come to a foreign drain of gold; and this depletion of the currency, we know, flows from the store at the Bank of England into the hands of the foreign creditors of the nation. We export to, and import from, other nations on a gigantic scale, and as our imports are invariably in excess of our exports, it follows that the balance of indebtedness on this score is always very considerably against us; but there are other debts due to this country which from time to time turn the balance in favour of England, and the prices quoted for bills on the various Exchanges are the indexes which tell us whether gold is likely to be either received from, or sent to, the great commercial centres of the world. Other debts due to this country have been mentioned--debts which either tend to reduce or turn in our favour the balance we owe to foreign countries. England has immense sums invested in foreign securities, and the interest received therefrom acts in this direction. So, too, does the huge sum earned by her ships in the shape of freights. Then, again, London, still earns a large amount in the shape of commissions, even if her position as the Clearing House of the world is now less powerful than formerly, owing to large accumulations of capital in other centres. On the other hand a considerable amount of foreign capital is invested in English securities, which, when sold on the Stock Exchange, give the foreigner a claim on our stock of gold; and though we, by similar sales of foreign securities, can prevent this temporary drain of specie, the enormous dealings in stocks and shares on the various Exchanges are most keenly watched by the directors of the Bank of England, lest huge realisations of British securities by foreigners should drain the Bank of its gold, with which international indebtedness can alone be settled. This brings us to the markets for bills of exchange, the prices of which, like those of every other security, are settled by supply and demand. If, at a given date, this country owes a foreign nation considerably more than it has to receive, then bills on England will be plentiful in that country; and, further, they will be cheap, because, as debtors to England have less to remit than the aggregate of bills on England offered for sale, the supply will be in excess of the demand, and English bills, consequently, can be bought at a discount. Conversely, the supply of bills in London on the foreign country will be smaller than the sum English debtors owe therein, and in order to save the expense of exporting gold, such bills will be eagerly sought after, and, as the supply is smaller than the demand, buyers soon drive them to a premium, when the rate of exchange is said to be "unfavourable" to England. As the balance of our international indebtedness must be cancelled by gold, it follows that the fewer the bills offering the higher will be the prices paid for them; and when, just towards the end, it becomes evident that the supply is limited the bidding is often spirited; but the premium paid cannot exceed for any considerable length of time the expense incurred by exporting and insuring the precious metals between any two countries, as the debtor always has the choice of despatching gold to his foreign creditor, and, naturally, he chooses the cheaper expedient. The extreme fluctuations are called "gold points," and they mark the limit to premiums procurable on bills of exchange. The table given below will show us those points at which gold will probably either leave or reach this country: ============================================================ Exchange. \| Mint Par. \| Gold \| Gold \| of Exchange. \| Exports. \| Imports. -----------------+------------------+-----------+----------- London on Paris \| Francs 25·22½ \| 25·12½ \| 25·32½ Berlin \| Marks 20·43 \| 20·34 \| 20·52 New York \| Dollars 4·87 \| 4·84 \| 4·90 ============================================================ When the rates are near those given in the second column, the Bank, if its reserve be low, begins to consider the advisability of raising its rate of discount, for it is evident that foreign bills are at a stiff premium, and that a demand for gold may be made upon it at any moment. Of course the difference between the "gold points" gives scope for speculation, and some cambists gamble in bills for the rise or the fall just as speculators do in securities. Then, again, the arbitrageurs largely influence prices by buying and selling securities which are dealt in on the Stock Exchanges of more than one country. Wars, revolutions, panics, and social upheavals also cause abnormal fluctuations in the rates. Let us assume that a drain is threatened from Paris. The gold in an English sovereign is, we can see, worth about 25·22½ francs, and if only 25·12½ is being offered on 'Change, it follows that bullion will soon be exported to France. This the Bank wants to prevent. The cost of transmission of bullion between the two countries is about one half per cent.; therefore, in order to induce French capitalists to invest in English bills of three months' date, the rate of interest in London must be more than two per cent. in excess of that in Paris before it will pay them to ship bullion to this country, if it be the intention of the purchasers to withdraw their capital when the bills mature, as the gain of two per cent. per annum for three months only just balances the loss of 10s. per cent. incurred on specie shipments, while no margin is left to defray possible loss through unfavourable exchanges at the time of withdrawal. Were a purchase of six months' bills contemplated, the difference in the two rates would only have to exceed one per cent. before bullion could be exported profitably. When, therefore, the Bank of England wishes to influence the foreign exchanges, it raises its rate by one, instead of by one half as is usual when the drain is caused by the currency requirements of this country, or by an increased demand for loanable capital when trade is active and the foreign exchanges favourable. One constantly hears the question: Why has the Bank of England raised the rate by one instead of by one half as it did last time? A glance at the foreign exchange tables will generally supply the answer. If the expenses for transporting and insuring bullion between any two countries are appreciable, then were the Bank rate raised by one half (remembering that an addition of one half per cent. per annum gives a profit of only 2s. 6d. per cent. on a transaction in three months' bills) it is evident that the inducement is not sufficient to attract gold over here for that consideration alone. By raising its rate, and, if necessary, borrowing in the market in order to bring the market rates in touch with its own, the Bank makes an investment in English bills a profitable transaction; and the greater its excess over foreign rates, the stronger is the inducement to send money to England. Of course, were this country really living on its capital, this influx of gold would only postpone the inevitable day of settlement, for a bankrupt does not increase his wealth by borrowing from one person in order to pay off another. But our receipts do not always coincide with our payments; and when, for instance, gold is sent to the United States in the autumn to help to pay for crops imported here, the Bank of England, by raising its rate of discount, and making that rate a representative one, attracts gold from the Continent, in order to tide over the interval between debts payable by us immediately and debts due to us at a future date. English bills being a profitable investment, the price of paper on England at once begins to rise, and when the so-called gold point is reached the precious metals are shipped to these shores, because the premium on bills on England is in excess of the cost of despatching bullion. Every rise in the rate of discount here induces foreign holders of long-dated paper on England to retain their purchases. If they bought three months' bills on England when the Bank's discount rate was three, interest at the rate of three per cent. per annum was deducted from the face value of the bill to make it equivalent to a bill due at sight. Should the minimum rate be raised to four per cent., and were the holders then to remit the bills to this country to be discounted, they would have to submit to a deduction at the rate of four per cent. per annum. In other words, they would lose one per cent. per annum on the transaction. Long-dated bills would therefore be held until near maturity in order to avoid this loss. An accretion to the Bank rate, then, not only attracts gold or capital here, but it also induces foreign holders of long-dated bills on England to keep them in their cases. On the other hand, a fall in the Bank's rate of discount from, say, three to two per cent. might not only slacken the demand for English bills, but it would also cause a considerable number of long-dated bills on England to be sent over here to be discounted, as the foreign holders would naturally be anxious to secure the profit between the three per cent. per annum paid to them, and the two per cent. per annum at which they would then be taken from them. The result might possibly be a temporary drain of gold from this side. But it is when a home and a foreign efflux of gold occur at the same time that the situation becomes serious, and unless immediate action is taken by the directors of the Bank of England to check the outflow, there is always the danger--so small is our gold reserve when contrasted with our exports and imports--that a balance against us at an unlucky moment may create an awkward tension, which, unless speedily relieved, may possibly produce a crisis. We like to flatter ourselves that England is always safe; but so large is the amount of bills offering from day to day in the London money market that the very doubt of there not being sufficient capital in the possession of the banks to discount them creates uneasiness; and if it were thought that the Bank of England, which holds the few millions of reserve upon which hundreds of millions of credit rest, could not retain its gold, excitement would reach fever pitch in this country, for everybody's income would be in danger, and the Government, whose supineness allowed such a state of affairs to develop, would be in danger too. But we know that, in the rate of discount, the directors of the Bank possess an effective instrument to prevent such a catastrophe, and have the experience to use it to advantage. Money begins to leave the Bank for internal circulation during the summer months in order to meet the demands created by the holidays and the harvest, and then in October there is always the probability of a large outflow of gold to the States to help pay for the crops imported therefrom; while the movement of specie to Scotland in November, occurring as it does just at a critical moment, is likely to cause some apprehension, should the Bank's reserve have been depleted earlier, unless the fact that it is merely a temporary transfer to enable the Scotch banks to comply with the Act of 1845 be thoroughly grasped. The October drain of gold from the Bank when the New York exchange is unfavourable has in it an element of danger, especially if it happen at a time when the reserve at the Bank of England is unusually low; and if loanable capital be then abnormally scarce there is always the risk that the end of the year requirements may produce a tension, which, should credit be bad at the time, may develop into a panic. If the Bank manage well, however, it fortunately often foresees that the autumnal demands may possibly impose a severe temporary strain upon its resources, and by raising its rate in anticipation of a short period of exceptional demand, it attracts gold to itself in order to be thoroughly prepared for possible large depletions of currency later on, for it is easier to accumulate gold before the event than to check an outflow when the movement is beginning to create uneasiness, and to attract attention to the lack of preparedness on the part of the Bank to meet large withdrawals of specie for export. It is not my intention to write a treatise on the foreign exchanges, and I am quite well aware that I have only touched on the fringe of a great subject; but if these illustrations help, however slightly, to elucidate certain of those undercurrents which determine prices, then the sole aim of this chapter has been attained. CHAPTER IX. Banks and the Creation of Credit. We have seen how the Bank of England came to occupy so commanding a position in the money market, and we now have to consider why its rate of discount is still a fairly reliable index to the value of loanable capital. Its advent was extremely distasteful to the private bankers, who then reigned supreme in London, and who were not slow to recognise in the new corporation a formidable competitor, for a company which financed the Government was obviously to be feared. Before 1826 the Bank of England was the only joint stock bank in the country. Its notes gradually drove those of the London bankers out of circulation, and until its joint stock rivals firmly established themselves in the Metropolis, the Bank was in every sense the most powerful institution of its kind in the land. Being by far the largest lender of capital in the country, it was only natural that its rate should accurately interpret those forces which make loanable capital dear or cheap, as the case may be. But the Bank could not arbitrarily fix the value of money for a very considerable period, even when it was able to issue notes without let or hindrance, any more than it can now. Supply and demand must settle that ultimately; and whenever the Bank inflated prices by the over-issue of paper, we have seen that the reaction produced thereby invariably threatened its existence. This is easily explained. Persons borrow money in order that they may trade with it; and sudden loans of large amounts of capital in the shape of notes immediately stimulate the markets, and the increased demand engendered thereby causes the prices of commodities to rise. Rising prices, whether of securities or goods, give a marked impetus to speculation--so hopeful are traders directly markets begin to improve; and increased speculation causes further rises in the prices of both commodities and loanable capital. Everybody wants to borrow, and to share, in the coming period of great prosperity. With prices rising here, imports naturally increase, as foreigners are anxious to sell their goods in the best market. On the other hand, the English markets have become less profitable to buyers, and, consequently, exports fall off, the result being that the balance of our indebtedness to other nations is largely increased. The foreign exchanges soon begin to move against England, and the Bank of England (we will assume) which had created the speculation by large issues of notes, suddenly finds that it is threatened with a foreign drain of gold, and is compelled to raise its rate in order to protect its reserve. Since 1844 this power has, of course, been taken out of the hands of the Bank; but it is evident that, even before that date, the Bank of England could not fix the rate of discount, for whenever it made the attempt it failed signally. The above illustration fully explains the reason why. Both before and after the Act the Bank of England would have suspended payment upon more than one occasion, when it neglected to keep an adequate reserve, but for Government intervention; and it will be in the same plight again if it trade with too large a proportion of its resources. The Bank was then by far the largest dealer in credit, and from time to time it stated the minimum rate at which it would lend or discount. But the private bankers were at liberty to underbid it; and although it could, by making sudden advances, cause money to fall in value, its power was not of a lasting character, and the rise which followed was quite beyond its control. Its rivals are now much more powerful, and the Bank is only one large dealer among many--therefore it has to either raise or lower its rate according to the demands made upon its resources; but from its position in the centre of the money market it still possesses a latent power for possible evil, which appears to have escaped the attention it deserves. This brings us to the vexed question of the creation of credit by a bank, and though it is stoutly maintained that an ordinary banking company cannot create credit, I venture to think that, given certain conditions, it does. But perhaps, before proceeding further, it will be better to briefly discuss the Clearing House system. Cheques and bills, we all know, pour up to London in a constant stream to the numerous banks, and are presented by them either to the firms upon whom they are drawn or to their agents at the Lombard Street Clearing House. As every bank which is a member of the Clearing House keeps an account with the Bank of England, the debit and credit balances (the result of this exchange) are adjusted in the books of the Bank at the end of each day, and so, though the balances standing to the credit of the various banks are diminished or increased, the total sum to the credit of all the clearing bankers remains unaltered. In other words, the balances, which are the outcome of the exchange of credit documents at the Clearing House, are finally arranged by transfer entries in the books of the Bank of England. Every cheque presented in the House is debited to one bank and credited by another, therefore the totals of the debit and credit entries must agree; and if the totals are the same, then the debit and credit balances must agree also. In the smaller towns the banks exchange the local cheques between themselves, and settle the balances in cash or by payments through London. But Birmingham, Bristol, Leeds, Leicester, Liverpool, Manchester, and Newcastle-on-Tyne have Clearing Houses of their own at which local cheques and bills are presented. We can now approach the question of the creation of credit by a bank. Suppose a bank suddenly increases its advances to its customers by £1,000,000, and that the customers pay away the whole sum by cheques. The said cheques are, say, paid by the recipients to the credit of their accounts with other banks, which present them at the London Clearing House. The balance of the bank which made the advance is thereby reduced £1,000,000 at the Bank, and the accounts of other banks are credited to the same extent; so the deposits at the Bank of England are not reduced one penny by the transfer. But £1,000,000 has been added to the working resources of the other banks; and as the liabilities of the bank that made the advance have not been reduced, surely this is a creation of credit? Of course, the bank which made the loan has lost £1,000,000 in "cash" at the Bank of England, and that asset would then be merged in "advances," which are up £1,000,000; and though the bank has not created credit in its own books, it has in those of its rivals. Surely, then, every bank which makes a new advance to a customer, who employs the sum placed to his credit to cancel certain debts of his own, creates credit in the books of other institutions. But the Bank of England can also create credit in its own. On the other hand, say, Bank A calls in £1,000,000 from the bill brokers, who obtain credit to the extent of £1,000,000 from, say, Bank C, and draw cheques thereupon, and hand them to Bank A, which takes them to the Clearing House. C's balance at the Bank is reduced by £1,000,000, and A's is increased by a like sum; but in neither case is the "liabilities" side of the balance sheet affected. It is a mere transfer of credit from one account on the "assets" side to another on the same side, while the bankers' balances at the Bank of England remain the same. However, should Bank A advance £1,000,000 to a customer, who draws cheques against it, then the creation of credit in the books of other banks begins, as illustrated by our first example. Again, take the case of a bank which sells securities, say Consols, to the amount of £1,000,000. It receives cheques upon other banks for a like sum; and these it takes to the Clearing House, where it presents them to those banks upon which they are drawn. The result is that the selling bank's balance at the Bank is up £1,000,000, and that the accounts of the other banks are down £1,000,000; but their liabilities also are down £1,000,000, whereas the liabilities of the selling bank are precisely the same. It has simply transferred £1,000,000 from Consols to "cash" at the Bank of England on the "assets" side of its balance sheet. Such a sale has reduced the floating capital of the banks by £1,000,000. Further, could not a little "window dressing" be done in this manner were a bank to find itself short of "cash" at the end of the half-year? By lending the sum so obtained the selling bank could create an amount of credit in the books of its rivals similar to that which it had previously destroyed. By buying stock back, too, it would produce exactly the same effect as if it made a loan. Now we come to the creation of credit by the Bank of England in its own books. Were the Bank to suddenly lend £3,000,000, the "Other Deposits" would be up to that extent, and "Other Securities" would also be up to a like amount, because the Bank would credit its customers and debit the loans. Both sides of its return are increased, but, so far, credit has not been created by these mere book entries, though the way for its creation has been prepared. The customers or persons to whom the advances have been made begin to draw upon their accounts by cheques, and as these cheques are returned by the other bankers to the credit of their accounts (bankers' balances) it follows that "Other Deposits" are not reduced at the Bank. The Bank, then, has created £3,000,000 of credit in its books, and though it can no longer make sudden loans by a huge issue of notes as was possible prior to 1844, yet, because it holds the bankers' balances, we can see that it is able to produce precisely the same effect by means of another instrument. If the Bank lends £3,000,000 to the Government, "Public Deposits" and "Government Securities" advance proportionately. When the Government begins to pay out, then a large part of this sum returns to "Bankers' Balances," and credit is created at the Bank of England to the extent of the sum so returned. But the banks (Lombard Street) have more to lend; therefore money is made artificially cheap. On the other hand, the Government sometimes borrows in the open market on Treasury bills. Credit is then transferred at the Bank through the medium of the Clearing House from "Bankers' Balances" to "Public Deposits." The resources of Lombard Street are reduced, and until Government disbursements are made, and credit thereby transferred to Lombard Street, money becomes tight, and borrowers are often driven to the Bank. We have seen that in the end an over-issue of notes is certain to reduce the Bank's reserve to a dangerously low level, and that, therefore, directors who know their business would hesitate to make so risky an experiment. The same argument is equally applicable to the creation of credit by sudden large loans on the part of the Bank in its own books. Such loans, we have seen, increase both sides of the return; but the Bank's reserve of notes and coin in the Banking Department remains at the same figures, consequently, its ratio per cent. to liabilities shows an ominous decline, which is, of itself, a warning that something is wrong. Let us assume that the Bank suddenly lends £5,000,000. Money is thereby made artificially cheap, and the market rate for bills must fall in consequence. But the bankers' balances have been increased in the books of the Bank of England, and Lombard Street is not going to quietly look on while Threadneedle Street does all the business. Consequently, the bankers lend a portion of their balances at lower rates still, in order to attract business to themselves, and the market rate falls again. Here we have a situation analogous to that described in the earlier part of this chapter. Now suppose this movement took place in October, and that a drain of gold occurred outwards. The Bank, in order to arrest the said drain, would have to raise its rate, and to bring the market rate in touch with its own it would be compelled to sell Consols, thereby reducing the bankers' balances in its books, and, of course, lessening the power of the banks to lend. But such a process is an expensive one, for the Bank is in reality borrowing back at panic prices the capital it created during a time of temporary ease. Although the Bank undoubtedly possesses this power, the directors are not likely to abuse it, because the risk incurred is out of all proportion to the possible gain if the deal is carried through successfully; so we may say that their power to create credit in their books is limited or regulated by the ratio per cent. of the Bank's reserve to its liabilities. Of course, it may be asked: Is it safe to entrust such power to a board of directors who have to earn dividends for a body of stockholders? That is a difficult question to answer, and one, moreover, to which there is no occasion to reply in this work. It may safely be said that no director who understands his business would take the risk upon any consideration; but there is the remote chance that an incompetent Governor might be placed at the helm, and in that event, however improbable, should he lose sight of everything but the dividends, he might create a terrible panic throughout the land. On the other hand, all who see the Bank return from week to week may read the signs, and should the ratio fall abnormally low the critics would flagellate the Governor unmercifully, and the business man, who is unaccustomed to the pleasantries of criticism, unless he be a most hardened member of his species, squirms under such a lash, fearful that his friends may read just what the Press thinks of him; so he takes heed. Though the Bank's rate is not always the same as the market rate, it is seldom very much out of touch therewith. When the directors find that their rate of discount is too high to attract custom, then, if the reserve be also high, they lower their minimum in order to get a fair share of the business that is doing. Their other alternative, of course, is to borrow on stock, and in that manner to compel the bill brokers to pay them a reluctant visit. The policy of the Bank has never been one of "grab," though the bill brokers often grumble; but its position, in relation to the market, is an extremely difficult one, so difficult at times as to be fraught with great anxiety; and remembering the power that devolves upon it by reason of its holding the bankers' balances, its policy seems one of enviable restraint and moderation. But that is only what everybody expects of the Bank of England. CHAPTER X. The Battle of the Banks. But little has hitherto been said concerning the relations of the Bank of England with its rivals in the money market, and in order to trace the movement from its beginning we must return to 1826, in which year joint stock banks could be established in England at a greater distance than sixty-five miles from London. The Bank stoutly resisted this innovation, but the Government, in consequence of the constant failures of the country private bankers, passed the Act of 1826, and the thin edge of the wedge once inserted, the Bank's monopoly in London soon disappeared. The London and Westminster, despite the determined opposition of the Bank of England, opened business in London during 1834, and the Bank's monopoly of banking was gone. All that then remained to it was the exclusive privilege of issuing notes in and within sixty-five miles of London, the only legal monopoly it still enjoys. Unable to keep the joint stock banks out of London the Bank actively opposed them, as also did the private bankers, who, while the Bank refused to open accounts for the new companies in its books, declined to admit them into the Clearing House, which was founded by the London bankers about 1775. The irony of Fate! They are now a feeble minority in a house of their own building. But history--both domestic and economic--can supply parallel instances. Although the new system was destined to drive out the old, the joint stock banks made a bad start, and failures were at first so frequent that the public began to share the opinion of the Bank and to look upon them as anything but safe institutions. They were born in disaster, and their policy did not provide an antidote to the old evils; but, like the Bank of England itself, they were taught prudence by a series of panics and upheavals which threatened to wipe them out of existence. They were, in short, licked into shape, and that cautious prudent policy which now distinguishes our great banking companies is the fruit of a very bitter experience. Towards the middle of the nineteenth century the manufactures of Great Britain began to increase by leaps and bounds, and population, which always augments rapidly when food is cheap and abundant, kept pace with the country's unprecedented commercial activity. In 1801 the population of London was less than one million. In 1837 it had increased to about two millions; and at the present time Greater London contains over six and a half millions. It is quite evident that the Bank of England could not alone minister to the increasing wants of London, and both in the Metropolis and in the provinces its joint stock rivals rapidly accumulated credit. In June, 1854, the new banks were admitted into the Clearing House, and since that date they have carried all before them. They shared in the almost magical increase in the volume of British trade, but they neither created nor provided the incentive to that remarkable outburst of national prosperity which was the result of Free Trade, and which made this country the workshop of the world. Since then, however, the world has filled up. The population of the United States in 1870 was 38,500,000; in 1900, 75,500,000. In 1871 the population of the German Empire was 41,000,000. In 1901 it had increased to 56,000,000. During the same period the population of the United Kingdom increased from 31,500,000 to 41,500,000. There are more people in the world to be fed, and as the earth fills up the struggle for existence must surely become fiercer. Noticing this, people naturally inquire whether, seeing the changed environment, Free Trade is suitable to the times. Some years ago, when trade was bad, the bimetallic controversy was raging, but since 1895 its advocates have been dumb, for the simple reason that people will not listen to theorists when times are good. They are then too intent upon making money. They think they may not get the chance again. No doubt, when the depressed portion of the cycle came round bimetallists would have been heard again. But in the place of Bimetallism we now find Protection, and, in all truth, the question is serious enough; for, when the present wave of prosperity dies out in the States, there seems every probability that the huge American trusts will endeavour to swamp our markets with their goods. Free traders make quite a profession of faith of their commercial opinion. They declare that they are free traders with the same fervour they might infuse into the avowal that they were Protestants or Roman Catholics. But modern Christianity is eminently adaptable to every fresh situation. Is Free Trade? The worse the times become, the louder, probably, will grow the controversy between the free traders and the protectionists; and when we remember that our workshops support our credit, and upon what an amazingly small reserve of the precious metals that credit is based, it is evident that the question ought to be approached with the greatest caution; for a decision that emptied our workshops would ruin the nation. As the savings of the country increased, the joint stock banks accumulated credit with astonishing rapidity, and the Bank of England, slow to recognise the power of the new system, which was so admirably suited to the changed environment, was compelled to receive its hated rivals into the fold. The companies possessed no vaults for the storage of the precious metals on a large scale, and they were therefore glad to avail themselves of the facilities at the disposal of the Bank, whose premises were much better protected than their own. And then, again, as the Bank's notes were legal tender, the companies could send them from the head offices to the branches cheaply, while they were a convenient form in which to keep a certain proportion of their cash in hand. The evolution of the Bank of England, we can see, has not proceeded smoothly; but it is remarkable that an institution, which owed its pre-eminence entirely to monopoly, did not gradually begin to sink into a second-rate banking company directly its exclusive privilege of joint stock banking was abrogated and free trade in banking established in England. So conservative was the Bank's policy that it seems little short of marvellous that its joint stock rivals should have quietly endured its studied insults. The new movement was then, however, not only in its infancy, but was under a cloud as well, and through the companies grouping themselves around the Bank they enabled that institution to retain its position in the centre of the money market. The power incident to that position has been fully explained in the previous chapter. The London private bankers, whose lack of enterprise can only be attributed to the fact that they were imbued with those narrow City traditions which make London the home of Conservatism, also quite failed to grasp the situation, and allowed the new companies to expand in every direction, confident that so sudden a change must end in disaster, and, therefore, they were content to look on, to shake their heads sadly at the unprofessional conduct of those new banks, and to soothe their feelings by ever and anon declaring, with due solemnity, that joint stock banking would ruin the country. Certainly, the new companies did not manage well at first, and a few of them were wiped out in consequence; but, in spite of mistakes, they progressed, because their system was adaptable to the requirements of a growing England. In these times it is the fashion to apotheosise man--to picture him as a kind of demi-god; therefore, it is asserted that man makes his mark on the times. But it is surely more rational and logical to assume that the times gradually mould the particular cast of brain that is adaptable to a constantly changing environment, and that the man who chances to possess that cast of brain goes with the tide--which takes him a long way. At any rate, such was the case with the joint stock banks, which owe their success entirely to the adaptability of their system to a changing market. Moreover, that market is still changing. The old-fashioned London bankers found, to their great surprise, that they had not read the signs of the times aright; but the orthodox seldom play the _rôle_ of a prophet successfully, because they have lived too long in one groove, and so are apt to forget that England is not the world, which is steadily increasing in population. Instead of failing, the joint stock banks merely occupied the ground, and, by so doing, confined the business of the London private banker to the one street in which he was established and in which his father lived before him. They had no respect for age--those new companies! The joint stock banks spread their tentacles north, south, east, and west of his sacred City, thereby effectually preventing his expansion, and "concentrating" his energies in the one street aforesaid, just as the nations of Europe have "concentrated" the kingdom of the unspeakable Turk. Great movements seldom originate within London, which is strikingly lacking in originality, and that new blood from the provinces which flows in an ever-increasing stream towards the great City, and alone arrests decay, also seems to bring with it the new ideas. The London private bankers waited in vain for the expected disappearance of their rivals, who, despite severe panics and crises, continued to add rapidly to their resources, until, surrounded by rival branches, profitable expansion became difficult for the private banker, whose business is now so localised as to render effective competition with the companies impossible. He cannot make rapid progress because he does not possess the branches through which alone the necessary credit can flow to the central office, and therefore the extinction of private banking in its present form seems only a question of time, for the wealthy are certain to deal with those banks whose vast accumulations are at least the outward and visible sign of the confidence the public has in their stability. But the joint stock banks did not confine their energies to London. The London and South Western Bank, which was established in 1862, began a vigorous crusade in the London suburbs, with the happiest results to its shareholders; and the London and Provincial Bank, which was formed two years later--in 1864--established small suburban branches in every direction, with equally satisfactory returns for its enterprise; while the London and County, larger and, perhaps, more cautious than either, also recognised the advantages of suburban expansion. A branch bank belonging to one of these three banks is now to be found in almost every London suburb. The London and Westminster Bank (established in 1834) was the first in the field, but the atmosphere of the City is not favourable to progress, and the Westminster, though an exceptionally strong and well-managed bank, undoubtedly failed to move with the times. So, too, did the London Joint Stock Bank and the Union Bank of London, which has recently somewhat altered its name. It was not until the provincial joint stock banks invaded London that these companies began to realise the opportunity they had missed; Lloyd's and Parr's Banks however, evidently taking in the situation, adopted the new system, and by skilful amalgamations rapidly forced themselves to the front. The country banks, in short, practically took possession of Lombard Street. Why the Bank of England did not share the same fate as the private bankers has already been demonstrated. It certainly was not one whit better informed than they; and it sympathised with them in their distrust of the intruders, whose speedy downfall it quite expected to witness. That the joint stock banks must come to grief was the opinion of the majority of City men in 1834, and the then directors of the Bank were City men imbued with those tenets which found credence within the sacred square mile. The bank which keeps the Government account must always be a great power in the land. Had that account been removed in 1844, together with the last vestige of monopoly, the Bank--the directors of which shared to the full in that tenacity and narrow-mindedness characteristic of wealthy City merchants, whose businesses, and therefore whose ideas, flow in the narrowest of grooves--must have ceased to be a progressive institution. But no Government has ever hinted at deserting the Bank, whose record, though bristling with mistakes, is one of unbroken integrity; and the public has always looked upon its management as above suspicion. Especially was this the case during the first few decades of the new movement. The Bank of England had public opinion behind it; and the joint stock banks, concerning whose stability opinion was divided, were not then strong enough to keep their own reserves and to defy the Bank; but when their system had stood the test of time, the Bank opened its doors to them, and the companies meekly bowed to the inevitable--for they were not the power in Lombard Street in those days that they are now. In the first instance, we found the private bankers grouped around the Bank; and now we see our huge joint stock banking companies in a similar relation to her. They kept their reserves with her when their system was in its infancy, when the Bank of England, as a result of monopoly, was the greatest credit institution in the country. As the companies spread their tentacles throughout the land, accumulating credit at an extremely rapid pace, those reserves grew proportionately, until, to-day, we find the Bank of England in the centre of a system which owes over £910,000,000 in _cash_ to the public. Our modern credit system has developed around the Bank, which, as the holder of the bankers' reserves, now occupies an almost national position. That position is, undoubtedly, the indirect result of a monopoly which, prior to 1826, enabled the Bank of England to build up a huge business unopposed by others of its kind. In other words, it had a start of 132 years. The greater, consequently, attracted the smaller. But united Lombard Street is now a much greater power than Threadneedle Street--therefore it is always wise to remember that the Bank of England can only retain its position in the centre of the money market so long as Lombard Street is agreed that it shall. The banks are not legally obliged to keep their reserves with the Bank of England. Were they so inclined, they could withdraw them to-morrow and accumulate stores of the precious metals of their own. It follows, therefore, that the best of feeling should exist between the "Old Lady" and Lombard Street. Obviously she is not now in a position to dictate her own terms, as her greatest power is derived from the "bankers' balances" on the left-hand side of her balance sheet. Perhaps it is now easier to understand that the Bank of England, when it from time to time states the lowest rate at which it will discount bills for outsiders, occupies the position of a most important lender, whose minimum rate, though not always the market rate, is seldom either greatly above or below those of its rivals. CHAPTER XI. The London Money Market. It is usual, when describing the Money Market, to assert that it consists of the numerous banks in the City of London; but it seems to me that, in reality, the money market extends throughout the United Kingdom, for wherever there is a bank or a branch bank there is a market for money. Moreover, the demand arising for loanable capital in the provinces largely influences the rates of interest ruling from time to time in London, because, if demand is brisk in the country, the banks have less to lend in London, consequently the rate advances there. When reference is made to the money market the London short loan fund is invariably meant, and we now have to consider how this fund is formed. The banks, which are liable to the public for huge sums of money at call and short notice, are obliged to keep a certain proportion of cash in their tills and strong rooms and with the Bank of England in order to be prepared for any sudden demand that may be made upon them. Their cash in hand is, of course, required to meet the ordinary demands of a banking business, and that deposited with the Bank of England is held as a reserve fund against those risks of withdrawal from which a credit institution owing immense sums at call is never free. Roughly speaking, a well-managed bank would keep, say, six per cent. of its public liabilities in legal tender on the premises, and a further ten to twelve per cent. at its credit in the books of the Bank of England. The latter accumulation might be called the bank's _real_ reserve, for it is upon this that it would have to rely during a run. Secondly, from eighteen to thirty per cent. of its liabilities to the public would be invested in first class securities. Those of and guaranteed by the British Government are in great request for this purpose, as the Bank of England would not hesitate to advance against such investments should a company find itself compelled to meet a sudden drain upon its resources. Every prudent banker therefore takes care that a large proportion of these securities is included in his list, which would also contain Metropolitan and other Corporation Stocks, English Railway Debentures, Colonial Government Securities, and so on. A banker's list, in short, should be a so-called "gilt-edged" one. Thirdly, a banker lends a certain proportion of his deposits in the London money market. Some banks have eight per cent. there, some fourteen per cent., and others from fifteen to twenty per cent., though the larger and better managed companies generally employ from seven to fourteen per cent. therein. A certain amount of this "call money," however, represents money which has been lent to jobbers and brokers on the Stock Exchange for "carrying over" purposes at the various settlements, but by far the larger part of it is money which has been lent to the bill brokers and discount houses. In no sense can this asset in the balance sheets of the banks be looked upon as a reserve. It is money invested in the London short loan market--money lent to the bill brokers, who, in times of bad credit, might not be able to repay it on demand. Just at the very moment when bankers are most in need, this asset is the least available; therefore, it is about the worst possible form in which the reserve of a credit institution, owing large sums at call, can be invested. As a credit bank's debts are due at call and short notice, a true reserve can only consist of legal tender, and the till money, which is required in the ordinary course of business during normal times, certainly cannot be classed with that reserve. When considering what is a bank's real cash reserve, we ought to deduct from four to five per cent. from the ratio of cash in hand and with the Bank of England to liabilities, for a trader would not include the cash required from day to day in his business with any reserve he might accumulate against accidents. Reverting to investments, we might take Consols as an illustration of their liquidity. During normal times Consols can be sold for cash at any moment, but it is otherwise in a time of panic, when practically everybody wants either to sell them or to borrow upon them. The market is then disorganised, and people require either gold or large credits at their bankers--not securities. Hence, even Consols are unsaleable when a panic develops into a crisis. As the Bank of England holds the cash reserve of the nation, it alone can advance against securities in the midst of a crisis, and those banks which were caught short would then have to apply to the Bank for help. The Bank certainly would not lend upon any but gilt-edged securities during a time of stress, and if their customers then made a call upon them those companies which held second-rate investments would have to close their doors, as they could not obtain assistance from any other source. A strong list of securities is, therefore, essential to every bank that is anxious to protect its customers against disaster. These three assets (cash in hand and at the Bank of England, money at call and notice, and investments) constitute a bank's so-called liquid assets. The ratio of total liquid assets to liabilities maintained by the best English banks ranges from 43 to 78 per cent. The last-named figures, which are quite exceptional in their strength, were published by Stuckey's Banking Company. The remainder of a bank's resources is employed in making advances and loans, and in discounting bills for its clients, whilst a small proportion is locked up in premises. We can now form some idea as to what the short loan fund of the London money market really is. Immense sums are collected at the head offices of the banks in London through their metropolitan and provincial branches; and, as the demands of trade are always uncertain--now brisk, then slack--it is impossible for them to invest all their surplus capital in securities; consequently, a certain portion of it finds remunerative employment in this channel. A huge stream of credit is constantly circulating through the three kingdoms, and London, so to speak, is the heart of the system. In years of active or good trade this stream increases in volume, and during years of depression it contracts; yet it is difficult to say whether or not the resources of the banks (the floating capital of the country) are appreciably lessened during a period of temporary depression, although the national turnover unquestionably is, as may be seen by the Clearing House returns. During years of rising prices and increasing trade activity profits are augmented, and, consequently, the resources of the banks are swollen; but when the profits are invested within the country, a similar amount of credit is returned to the banks by those who have sold their securities, and though less capital is created when trade is dull, it is questionable whether the resources of the banks then shrink very greatly, unless foreign securities are largely purchased. We have seen that this stream of credit flows to London, and as demand throughout the country is not sufficiently strong to attract it all back again, a large fund of loanable capital accumulates in the hands of the London banks, and flows from them to the bill brokers, who employ it in discounting bills of exchange. But though by far the greater part of the London short loan fund is accumulated in this manner by the banks, other firms and companies also discharge their surplus capital into it. The pool, of course, is not a stagnant one, for capital is constantly flowing in and out. The India Council, for instance, lends large sums in the London short loan market. The numerous foreign and colonial banks in London do the same, and so, too, do many of the large insurance companies and merchants, while during slack times money finds its way from the Stock Exchange to the bill broking houses. At first sight it seems strange that bankers should advance money to the bill brokers, and so provide their rivals with capital with which to compete against them, especially as the banks have discount departments of their own. Let us, however, consider the position of the bill broker in relation to the Bank of England and the money market. Towards the beginning of the nineteenth century the broker acted as agent for the country bankers, but this connection was naturally severed when the country firms opened accounts with the London bankers, and the broker, whose knowledge of bills was extensive, then transacted business for himself. Through holding out for high rates, the London private bankers drove a large amount of business into the hands of the bill brokers, who, by confining their attention solely to this class of credit document, came to be largely trusted by the joint stock companies, which could not obtain servants with the special training of their rivals. In no other country has the bill broker such influence as in England. In Paris, for instance, the customer discounts with his banker, who re-discounts with the Bank of France; but in London, for reasons already stated, bills find their way to the bill brokers, who re-discount either with the banks or with the Bank of England. Moreover, all the best bills get into the hands of the bill brokers, who, at one time, only discounted the acceptances of the banks and the larger houses; but they now take small trade bills, and, should the banking business grow less profitable, it is questionable whether the banks might not endeavour to dispense with the middleman whom they now encourage. We next have to consider the London money market as a whole. First we find a system which comprises Lombard Street and Threadneedle Street. In other words, the London banks, by keeping accounts with the Bank of England (Threadneedle Street), have placed that institution in the centre of the system, and we know the Bank derives great power from this situation; but its power is not innate--it is derived through and is dependent upon Lombard Street. This group we will call "the money market" or "the market." Then we have the bill brokers, of whom we will speak as "the outside market." Every morning the bill broker goes from bank to bank inquiring at what rates he can borrow; and if Lombard Street (the London banks) cannot supply him with all the capital he requires, then he is compelled to apply to the Bank of England, which, however, he always endeavours to avoid, because the Bank invariably charges him a higher rate than do the other banks. The Bank of England is a great bank of discount: consequently, the brokers are its rivals; so it is hardly reasonable to expect the Bank to charge the same rates to them as to its own clients, seeing that the brokers, by their competition, reduce the Bank's business. When trade is brisk loanable capital is in considerable demand, and the banks, therefore, have less money to lend to the bill brokers, who consequently are then driven to the Bank, which holds the bankers' balances. But the Bank of England's position is an extremely delicate one; and when the resources of Lombard Street are temporarily exhausted and demand centres upon itself, it has to take care that its ratio of reserve of notes and cash in the Banking Department does not sink too low in proportion to its liabilities. Should the demand upon its resources prove considerable, it raises its rate until the pressure is reduced. As a large part of the trade of this country is conducted through the medium of bills of exchange, it is absolutely essential that there should always be a market for good bills. Otherwise, panic and failures would be the result; so, were the Bank to refuse to take bills from the brokers at a price, our credit system would collapse at once, unless the banks themselves, determined to crush the brokers, offered to deal direct with the holders. But the experiment would be a most risky one to make. Moreover, it could not be attempted at a critical moment. When Lombard Street is not lending freely, or cannot lend further with comparative safety, the Bank, by raising its rate of discount from time to time, reduces the merchant's profit on each transaction, until at last money becomes so dear that he finds that he is making little or no profit on his goods. He therefore produces less, and, consequently, discounts less, when the pressure upon the Bank relaxes. So long as money may be obtained, let the price paid for it be what it may, a sense of security pervades the community; but were it whispered during a period of temporary tightness that the Bank refused to discount good bills at any price, our credit system would be in imminent danger, for the trade of the country would be at a standstill. Further, did such a state of affairs continue for many days, the crash would come, and the Bank of England would then be swept away with the rest of the market. Our present system is so delicately poised that the Bank simply dare not refuse to take good trade bills from the brokers. We next come to the other side of the picture. The broker, when he goes his rounds, sometimes finds that the surplus resources of the banks are abundant, and that they are ready to let him have even more than he requires. When he makes this discovery, he begins to higgle, to try to ascertain the lowest rate certain banks are prepared to accept; for the difference between the rate at which he discounts bills for his own customers and the rate at which he re-discounts or borrows, is his margin of profit, and he is naturally anxious to make it as wide as possible. (The poor man, be it remembered, does not visit Lombard Street simply because he finds the air pure and the society of bank officials congenial.) He therefore does his best to discover those banks which are in funds, and, having found them, to induce them to lend as cheaply as possible. This he can do when loanable capital is cheap and abundant, and the Bank of England probably doing but little business. Possibly, though the Bank rate is at two and a half, bills are being taken by the brokers at one and a half. Then the Bank, in order to get business, either lowers its rate of discount or else, by selling stock, endeavours to lessen the resources of Lombard Street. If the Bank adopt the latter expedient, it usually sells Consols for cash, and buys them back for the account, thereby temporarily reducing "bankers' balances," and attracting business to itself. The banks, having less to lend, raise their rates, which then approximate more closely to the Bank rate. The brokers often complain bitterly of this interference by the Bank of England with the market's supply of loanable capital, asserting that this artificial enhancement of rates by the reduction of bankers' balances through the sale of stock affects their business injuriously, and benefits the Bank but little; and it certainly is difficult to see how the Bank of England can make a profit out of the transaction. On the other hand, when the market rate is appreciably below the Bank rate, it is impossible to attract foreign gold to London; and the Bank, by borrowing on Consols, and making its rate representative, is acting in the public interest, should it be desirable either to attract gold to this country or to prevent its leaving these shores. We can now see that the Bank of England, though it states its minimum rate, is often powerless to transact business thereat; and, recognising that its own rate is out of touch with the market rate, the Bank often discounts bills for its own customers at the rates ruling in the open market, as, were it to refuse to do so, its clients would naturally take their bills to the cheapest house. When, however, Lombard Street is empty, and the bill brokers are compelled to approach the Bank which holds the final reserve, the Bank of England is frequently in a position to charge its rivals one per cent. above its declared minimum, and the bill brokers quite naturally feel a little sore. For this reason they try every source of supply before making application to the Bank. As security against loans made to them the brokers usually deposit either bills which they have discounted in the ordinary course of their business or gilt-edged securities, but sometimes the bill broker's credit is so good that the banks lend him money at call practically without security. When securities are deposited they are of course returned directly the loan is paid off. There is also another little point to which attention may be drawn: to wit--that, although the market we are discussing is a special market, yet if a borrower's credit be good it is generally possible to obtain an advance either at or about Bank rate. CHAPTER XII. The Bank Rate and Stock Exchange Securities. At the present time large advances are made by the banking companies to members of the Stock Exchange, and it is supposed that at the beginning of 1894, when the Bank rate fell to two per cent., and an investment of surplus funds in the London short loan market brought in very poor returns, the banks, tempted by higher rates, largely increased their loans to the Stock Exchange. In 1890 rumour had it that a few of the banks made rather heavy losses in connection with the South American gamble, which brought down the firm of Barings; and the unanimity they displayed, under the leadership of the late Mr. Lidderdale, in supporting the tottering structure, certainly lends force to the suggestion; for philanthropists are not to be found either in Lombard Street or in Gorgonzola Hall. The same rumour was circulated after the Kaffir boom in 1895, and a little later it was whispered that some of the banks intended curtailing their loans to the Stock Exchange, and that in future mining shares would be received with the greatest circumspection. So close is the connection between the banks and the "House" that the utmost consternation prevailed when it was feared that the banks would not touch certain stocks and shares of a fluctuating character. The mere rumour created almost a panic among those dealers whose books were full of the tabooed securities. But 1895 was a bad year for the banking companies, and, from a dividend point of view, 1896 was little better, for the Bank rate did not touch two-and-a-half per cent. until September of that year. The short loan market, therefore, was not a tempting place into which to pour surplus deposits, so the banks apparently thought better of their decision (if it were a decision), and continued their loans to the Stock Exchange on the same liberal scale, because such loans yielded a much better return than those to the bill brokers. The very rumour that the banks intended increasing their margin on, say, American Rails, would cause those securities to fall, and were the threat actually executed, then, unless strong support came either from the public or from New York, the result would be failures of weak jobbers in that particular market, and a heavy fall in the prices of American Railway securities. There is the same link between the other markets of the Stock Exchange and the banks, and, such being the case, it naturally follows that the prices of securities are influenced by the abundance or scarcity of loanable capital, and that, therefore, continuation rates fluctuate with the Bank rate. But a very considerable proportion of the transactions conducted on the Stock Exchange is of a speculative or gambling nature, in which those mysterious persons called "bulls" and "bears" figure largely, and whose object it is, not to invest savings in particular stocks and shares, but to receive a cheque from their broker representing differences due to them on the rise or fall of the securities in which they are temporarily interested. The "bull" buys stock because he believes that it will rise, and that he will be able to sell it at a profit before the fortnightly settlement comes round, but he does not pay for it; and if his sanguine anticipation is not realised, so human and hopeful is he, that he endeavours to obtain a loan on his stock through his broker in order to carry it over to the next settlement, trusting that he will be able to sell at a profit before contango day again comes round. The broker sometimes obtains an advance on the stock through his banker, and so is enabled to accommodate his client, whom he charges both interest and commission. Again, the broker may carry over the stock through a jobber or with a money broker who is a member of the "House," as the Stock Exchange is colloquially called. It has been suggested that some of these money brokers are in reality agents of the banks--that, in short, they are the middlemen between the banks and those who want to borrow on the Stock Exchange, just as the bill broker is the middleman between the banks and those persons who possess bills. The bill broker deposits the bills he has discounted for his customers as security against a loan from the banker, and the money broker deposits the stocks and shares against which he has advanced to members of the Stock Exchange as security for a loan from the banker to himself. His profit, therefore, like that of the bill broker, would be the difference between the rate at which he borrows from the banker and the rate at which he lends in the House. When large sums are advanced in this manner the prices of stocks and shares are forced up to fictitious figures in the hope that the public will come in and buy. Yet the Stock Exchange Committee preaches about the iniquities of the outside broker! Far be it from me to defend the possibly questionable methods of the latter; but, to an unbiased observer, it sounds somewhat like the pot calling the kettle black. Huge sums of money are advanced every fortnight by the banks to the money brokers and jobbers, principally against sold stocks and shares, which are awaiting the arrival of _bonâ fide_ investors. The banks, of course, require a good margin in order to cover themselves against loss through any possible depreciation in the hypothecated securities, and when the settlement or day of reckoning arrives, fresh loans are made, or old advances are renewed, and the securities carried over to the end of the account. A high rate of interest naturally makes "carrying over" from account to account a very expensive operation, whilst an abnormally high rate renders the process prohibitive. When, therefore, the Bank rate is high and money is dear, a check is immediately given to speculation on the Stock Exchange, because those persons who have bought securities for a rise prefer to sell at a loss before the settlement rather than pay excessive contango rates. It follows, then, that dear money greatly reduces the dimensions of the accounts open for the rise. The banks, too, often become alarmed by the magnitude of the account, and having demands upon them for capital elsewhere, they grow nervous and lend less freely, at greatly enhanced rates, and then jobbers and money brokers have to refuse a large number of applicants. The result may be either a fall in the securities dealt in by a particular market or a general depression throughout the House. Then the "bears" come in and buy, take their profits, and are jubilant. Conversely, a plethora of money and a low Bank rate encourage speculation, as was the case before the boom of 1895. Continuation rates are low, and capital comes out of trade into the better-class securities, which begin to rise in consequence. Then, for a little while, the "bulls" have it all their own way. But why does the Committee pose as the friend of the _bonâ fide_ investor? It is a little difficult to see where he comes in, unless it be in at the top and out at the bottom. As a matter of fact, there is so much gambling in securities taking place in the House that the genuine investor, if he do not understand the market, falls an easy prey to the "bulls" and "bears," who, by studying the habits of his kind, anticipate their requirements, and, after taking a large bite, pass on their hypothecated shares. On the other hand, the investor who studies the markets sometimes waits patiently for exhausted "bulls" or sells to frightened "bears." So, to those who know the game it is about as broad as it is long. CHAPTER XIII. The Banks as Stockbrokers. Were business on the Stock Exchange solely of an investment nature, it has been suggested that that institution could dispense with over fifty per cent. of its members, for, during recent years, a large amount of the investment business of the country has drifted to the banks, which place their orders in the hands of a few brokers, with whom they divide the usual one-eighth per cent. commission. The large banking companies are outside brokers, and so eager are some of them to attract this class of business that they offer their clerks half the commission received from the broker upon all business introduced by them. Seeing that the average bank clerk is absolutely without experience of the markets, touts of this variety are a source of danger to the public. The banker who divides his share of the commission with the clerk who introduces the business is satisfied with one-thirty-second per cent. commission; but the broker, who only gets one-sixteenth instead of one-eighth per cent., is, probably, less eager to make a close bargain for a customer of the bank than for one of his own. On the other hand, the volume of investment business which flows through the banks to the Stock Exchange is so large that those brokers who are favoured with the banks' custom must earn considerable sums by way of commission. Whether orders from customers of the banks receive that individual attention which the brokers give to those from their own clients is, however, another matter. Most of the banks have Stock Departments, to which orders are sent by their country branches. These orders are steadily increasing, and the tendency seems to be for a large number of the provincial public to do their investment business through the banks. This class of business is, therefore, gradually drifting to the banks, and doubtless, as time goes on, the banking companies will become the recognised channel for the _bonâ fide_ country investor. It follows that the non-speculative business is getting into a few hands, with the result that a large number of brokers on the Stock Exchange are, so to speak, "starved," and consequently obliged to turn their attention to the demand created by the more speculatively disposed members of the public. Yet, strange to say, in spite of the fact that orders are now diverted to the Stock Departments of the London banks and that, therefore, fewer brokers are required to transact the investment business of the country, the members of the Stock Exchange are increasing numerically. Seeing that the safe business is drifting through the banks into the hands of a few large brokers we may well ask how the smaller men obtain a living from their business? The ground, year in year out, is being farmed assiduously by the banks, whose large capital and established credit inspire widespread confidence; and in the face of such competition the small broker's chance of success does not seem encouraging. How can he make a business? The banks, who place their orders with strong brokers, guarantee those customers who deal through them against the insolvency of both the broker and the jobber, and such a guarantee is unquestionably worth having. The small broker, as a rule, possesses very little capital; whereas the person who instructs his banker either to buy or to sell is conscious that he is dealing through an institution whose credit is practically unlimited, and whose resources amount to many millions. He has not, therefore, to ask himself whether his broker is safe, and this sense of security, inspired by a bank's millions, undoubtedly causes many people who would rather do business direct with a member of the Stock Exchange to deal with the banks. Moreover, a bank official is quite well aware of this advantage, and when a customer, who is undecided whether or not to employ a broker, asks what inducement the bank holds out to him, he quietly replies: "You have the bank's credit upon which to rely." Such an answer makes a customer reflect. Further, it seldom fails to effect its purpose, because, in the first place, it instils a doubt in the client's mind regarding the means of his broker; and, in the second place, because he cannot fail to recognise the greater security the bank affords him. It is evident, then, that the small broker's path is bestrewn with almost insuperable difficulties, and that it is extremely hard for him to attract safe business. But the banking companies do not arrest the flow of speculative orders to his books. The banks, which have a horror of speculation, confine their attention to the buying and selling of stocks and shares through their brokers. Were they to encourage gambling in securities they are fully aware that the result would be disastrous to the business of banking, for a certain number of their customers would be sure to neglect their business in the hope of snatching differences on the Stock Exchange, and such a policy would end in a crisis that would bring the country to the verge of ruin. For this reason alone the banks firmly and wisely refuse to foster speculation among their clients. Capital, we all know, is the savings of labour; consequently the greater the profits made in trade during any one year, the larger is the fund awaiting investment. Now, if the banks were to incite the gambling fever among their customers, this fund would tend to diminish each year, and, seeing that the prosperity of the country is entirely dependent upon its trade, bankers, customers, and stockbrokers would speedily become involved in common ruin. Small wonder, then, that our large banking companies, which are responsible to the public for millions of money--a large proportion of which they must be prepared to return at any moment--decline to open speculative accounts for their clients. It would be madness on the part of such institutions to divert their customers' attention from trade to speculation in securities; and for this reason the bank clerk as amateur commission agent seems a step in the wrong direction. Moreover, in this respect the policy of the banks appears contradictory. Recognising the temptations to which their clerks are exposed, it is their practice to instantly dismiss those men who indulge a passion for betting; yet some of them deliberately encourage their servants to tout for investment orders, apparently unconscious of the fact that once their attention is drawn to the markets, some of the clerks are almost certain to end by gambling for differences on their own account. Helping themselves to the money of the banks is probably the next step. Were not the question so serious, the fact that directors cannot make so palpable a deduction would be positively humorous, for it is evidently quite as undesirable, from their point of view, that a clerk should bet upon a stock as upon a horse. The modern credit system, it will be seen, places a very large part of the safe or investment business in the hands of a minority of brokers, who, like the bankers, much prefer to do a good commission business, and to leave speculation to the smaller brokers, who have less to lose than they. These favoured brokers have grown accustomed to sleeping comfortably o' nights, undisturbed by the vision of settling day on the morrow; and, quite blind to the cause of their enviable freedom from care, they are disposed to be loud in their abuse of the risky manner in which some of the smaller brokers conduct their business. But, seeing that the non-speculative orders flow from the banks to themselves, it would be interesting if they would attempt to explain how the army of small brokers can live unless they cater for the wants of the speculator. As a rule their capital is small, consequently they cannot afford to wait years while they slowly build up a connection; so, as the safe business is cornered, they accept the risky. This they do, not from choice, but from necessity; and the Stock Exchange Committee, in order to prevent additions to the ranks of these undesirables, should take steps to reduce the number of members of the Stock Exchange very considerably. Already the investors of this country have to support a small army of over four thousand of them. Of course, after every period of excitement, numerous weak members of the Stock Exchange are weeded out, and, in a sense, the _bonâ fide_ investor is the pigeon that is plucked by the speculator. The bulls buy in the fond hope that the investor will come in and relieve them of their stock; and the bears sell securities which they do not possess, trusting that investors will also sell, thereby enabling them to buy at a low figure and to pass on their securities at a profit to those to whom they have previously sold. The position is therefore often an artificial one, created by operators for the rise or fall, and the investor, unless he thoroughly understands the markets, is like a pigeon among hawks. The larger the number of members of the House, the greater is the risk run by the investor who deals with a small broker; and as the investment business of the country flows largely in a particular channel, it is more than probable that, unless the Committee decides to admit new members sparingly, a large number of small brokers will one day be "hammered" after a period of intense excitement. CHAPTER XIV. The Short Loan Fund and the Price of Securities. A certain proportion of the capital which flows into the London short loan fund is invested in securities by the bill brokers and the discount houses, and, as the said securities are deposited with the bankers from time to time against temporary advances, it follows that their choice is largely restricted to those of and guaranteed by the British Government, because the margin exacted on the so-called gilt-edged varieties is considerably less than that demanded upon the more fluctuating stocks and shares. The bankers themselves invest largely in the same class, and they also employ vast sums in the short loan market; so that when the market rate for bills is higher than the interest received upon, say, Consols, the bankers are disposed to sell some of their Consols in order to obtain the higher rates ruling in the outside market. Obviously, then, any accretion or diminution in the short loan fund at once affects the prices of gilt-edged securities. If the Bank rate be high, and also representative, Consols ought to fall, and, conversely, if the Bank of England's rate be low, trade dull, and the market rate of discount smaller than the return on Consols, gilt-edged securities should rise. If this be the case, a low Bank rate must give an immediate incentive to speculation in securities, and, therefore, the condition of the short loan fund is intimately connected with the prices of stocks and shares, but more particularly with those securities in which lenders in the money market largely invest. The banks--let the condition of the money market be what it may--must, of course, always invest a certain proportion of their resources in Consols, but the sum so invested is not constant. Again, powerful business firms and companies hold Government stock as reserves against contingencies. The Government makes large purchases in the Consol market on account of the Post Office Savings Bank and the Sinking Fund, while numerous other "bull" points could be given. However, the fact remains that cheap money provides a strong inducement to large speculative purchases of Consols. The large capitalists and those persons whose credit is good can borrow at, and sometimes even slightly below, Bank rate on Consols from the banks, which are satisfied with a small margin against possible depreciation on Government securities. If, therefore, we examine the period between February, 1894, and September, 1896, when the Bank rate was stationary at two per cent., it will be possible to illustrate this tendency. Day-to-day money was then sometimes quoted at one per cent. and under, and this state of affairs occasionally extended over protracted periods. Now, suppose a person invested £20,000 in Consols at 112, and that his banker agreed to advance £18,000 against them at, say, seven days' notice at one per cent. per annum. Two-and-three-quarter Consols at 112 return £2 9s. per cent. (about). His annual income, therefore, on £20,000 would amount to about £490; but he owed his banker one per cent. on £18,000. Hence £180 must be deducted from £490. Upon a capital of £2000 he therefore earned £310; and a return of fifteen-and-a-half per cent. per annum on Consols is surely an excellent reward for his skill. Of course, we must not forget possible depreciation; but seeing that the banker's advance released £18,000, which he can use, he can afford to take some risk. The following example, however, affords a more practical illustration of the possibilities of speculation in Consols during the depressed portion of a cycle, when the prices of commodities are low and loanable capital is cheap. First, we want to ascertain the movements in this security from, say, 1894 to 1896, and of these the table given hereunder supplies a good idea:-- ========================================================================= \| 1894. \| 1895. \| 1896. \| Goschen's +----------+----------+----------+Bank rate from Two-and-three-quarters \| Highest. \| Highest. \| Highest. \|22nd Feb., 1894, per cent. \| 103⅝ \| 108⅛ \| 114 \| to 9th Sept., (Two-and-a-half \| \| \| \| 1896. per cent. \| Lowest. \| Lowest. \| Lowest. \| after \| 98⅜ \| 103½ \| 105⅛ \| Two per cent. 5th April, 1903) \| \| \| \| ========================================================================= Let us assume that a person invested £20,000 in Consols at parity in 1894, and arranged with his banker for a loan against them at Bank rate, and that the banker's margin was to be ten per cent. on the purchase price. He received, then, a loan of £18,000 from his banker, so the amount of his own capital remaining in the venture was £2000. Very probably, especially if his credit were beyond doubt, he would have made a closer bargain with his banker, and thus have reduced the margin slightly--but this is by the way. Upon his £20,000 in Consols he obtained two-and-three-quarters per cent., so that his annual income therefrom was £550. But as he had to pay his banker two per cent. per annum on £18,000, £360 must be deducted from £550. His capital in the speculation being £2000, he made £190 thereupon. This gain works out at nine-and-a-half per cent. per annum, and nine-and-a-half per cent. on Consols may surely be classed among the minor forms of temptation. Moreover, as the Bank rate stood at two per cent. for slightly over two years and a half, he had a long run for his money. But we see that he bought at parity, and that in 1896 Consols touched 114. Had he sold at 110 during that year, his £20,000 in Consols would have realised £22,000. He, however, owed his banker £18,000, so there remained £4000 to his credit. As his own capital in the speculation was £2000 he would have exactly doubled it, and nine-and-a-half per cent. per annum upon £2000 in Consols for close upon two years, with a bonus of £2000 at the finish, is painfully reminiscent of those financial dreams which so very seldom materialise; yet huge blocks of Consols were actually bought during this period of two per cent., and dealt with in the manner aforesaid. Of course, the results were not always so satisfactory as those given in the above illustrations, and no doubt many such ventures ended in a loss, for prizes of this description are for the lucky few; though it is usual to dwell upon them to the mortification of the mutable many. The snatching of profits in this fashion requires skill and considerable patience, and those persons who receive specious pamphlets telling them how money is to be made in a marvellously short space of time by an infallible system may appreciate the plausibility of my illustrations, but yet should remember that they may find the results of similar speculations in Consols very disappointing. The demand for Government securities created by these speculative operations is one of the causes which drive up the price of Consols during periods of cheap money, but it is not by any means the only cause. When the Bank rate advances, and capital can be employed more advantageously in the London short loan market, this period soon comes to an end, and consequent sales depress the Consol market. Very many of the better class securities such as Colonial Government stocks, Foreign Government securities, and so on, yield from three to five per cent., and when the Bank of England rate is at from two to two and a half, though the margin demanded upon such stocks is wider than that required upon Consols, the difference between the interest received in the shape of dividends and that paid as the price of a loan often makes speculative dealings in them decidedly profitable. As the Bank rate increases, and the speculator's profit margin consequently narrows, the tendency is for stocks and shares so "carried" to fall in value. The holders or gamblers then begin to sell, and as the increased supply of such securities is certain not to be met by an enhanced demand on the part of investors, prices must fall. Seeing the better class securities declining in value, those investors who had previously held aloof are tempted to come in, and the greater the reaction, the stronger is the inducement to buy; consequently, the lower prices recede the larger becomes the number of purchasers, until demand overtakes supply and prices again begin to move upwards. Broadly speaking, it is evident that, unless the markets are disorganised by panic or by some disquieting political occurrence, the prices of the so-called gilt-edged securities are influenced by the conditions prevailing in the London short loan money market. CHAPTER XV. Panic Years. When in 1667 a Dutch fleet sailed up the Medway, demolished a fort at Sheerness, and, forcing a way into Chatham Docks, burnt all the ships assembled therein, to the consternation of the inhabitants of London, there was a run upon the banks; but a Stuart regarded both events with equanimity, for "Old Rowley" had a mind above trifles of this description, possibly because he had learnt many bitter truths in a world seldom understood by Kings. Cynics are not born--they are made; and Charles II. had drunk from that cup which sharpens the understanding. France, during 1719 and 1720, was in the throes of the Mississippi scheme, which was engineered by that notorious Scotsman, John Law; and England, in 1720, witnessed the collapse of the South Sea Company, which Sir Robert Walpole, with rare insight and unerring financial instinct, had demonstrated was a mere gamble, that, at the best, could only enjoy a temporary success, which was absolutely dependent upon a rise in the company's stock; but the Government turned a deaf ear to his warning. Scotland, we have seen, had its Darien venture in 1699; and in 1720 all England went mad over the South Sea Company, which offered to relieve the Government of part of the National Debt, and entered into an insane competition with the Bank of England for that purpose. Then occurred some spirited bidding between the two companies for this privilege; but the directors of the Bank proved themselves the less mad, and left their rival in possession of the incubus and the road to ruin. The result of the bidding gave the necessary stimulus to the South Sea Company's stock, and, seeing it going up, the public at once rushed in, when the stock rose faster than ever. In a very short space of time the fever for speculation infused itself into the blood of the whole nation. The pace became so furious that the more thoughtful among the gamblers began to see the end and to sell, with the result that, upon a memorable morning, everybody wanted to dispose of his stock--and then the bubble burst. In June, 1720, the £100 stock of the South Sea Company was rushed up to £890, and a little later it touched £1000. Then the tide turned, and, as is invariably the case, all were as anxious to sell as a few days before they had been eager to buy. Every hour intensified the panic, until at length the stock fell to £175, and the difference between the highest and lowest quotations is eloquent of the loss inflicted upon the community, for everybody who had money to invest was interested in this gigantic gamble. Widespread misery and ruin followed. Suicide was of daily occurrence, and, after a momentary lull in the storm, popular indignation lashed itself into fury against the directors, for whom, it was openly declared, hanging was too good a fate. The Government, thoroughly alarmed, turned to the one strong man who had consistently opposed the scheme, and who, in consequence, was at that moment the most popular man in England; so Sir Robert Walpole stepped into the breach, and stemmed the tide of popular indignation and national disaster. At first Walpole was disposed to resort to half-measures, but when it became apparent that the South Sea Company was rotten to the core and that it must go at any price, he devised a scheme by which the East India Company and the Bank of England took over £18,000,000 of South Sea stock. The Bank directors, throughout this trying period, acted with a strange lack of caution, and the situation was only saved by Walpole's better judgment. The period was one of mad speculation, and no venture was too absurd to foist upon a public, which, until the crash came, did not display a gleam of intelligence or discernment, so blinded was it by greed. Naturally, those bankers who had advanced against South Sea stock did not escape loss, and many of the goldsmiths and private bankers were ruined by the reaction, while the Bank of England itself barely escaped. It is interesting to notice that, even in 1720, the public could only be tempted by a rising market; and it has remained true to this instinct, as, for some unaccountable reason, the "bear" is always looked upon as an undesirable kind of person. The next disturbance of credit occurred in 1745, when the Young Pretender, "Bonnie Prince Charlie," after defeating Sir John Cope at Prestonpans, resolved to march on London, and penetrated as far as Derby. The news of his arrival there reached London on the 4th December (Black Friday), and the City was seized with so severe a panic that business was suspended. Some of the citizens actually left the country, and even the King made preparations for flight. Everybody then wished to possess himself of gold, and a run at once began upon the Bank of England, which was taken completely by surprise, and only saved the situation by resorting to the expedient of paying its notes in sixpences--a somewhat lengthy proceeding, but one which enabled it to gain time. Nobody, however, would trust a Stuart, and the panic very quickly subsided. Learning that the Duke of Cumberland was advancing to meet him, Charles was compelled by his followers to beat a hasty retreat towards Scotland, and by the 23rd December the Highlanders had crossed the border again. In January, 1746, they defeated General Hawley at Falkirk, but in the following April the Prince lost the battle of Culloden, which dealt the final blow to the hopes of the House of Stuart. The panics and crises between 1745 and 1857 have been discussed in Chapters I. and II. of this book--principally in Chapter II. The Crimean War, through which this country muddled, was brought to a close in 1856, at a cost to the nation of £33,000,000; and it may perhaps be interesting to compare this sum with the £230,000,000 which has been expended in the South African struggle. Even for a Balaclava £33,000,000 seems a dear price to pay. But £230,000,000 for a Colenso! Glory makes a poor national asset. In 1848 Lord Dalhousie carried out a policy of annexation in India in a ruthless manner, and the native princes, thirsting for revenge, insidiously propagated a rumour among the native soldiery of the East India Company to the effect that the British Government was anxious to Christianise them, knowing that the unsophisticated Hindu preferred his sacred cow to the God of his conquerors, though he had probably little faith in either. At any rate, the princes appealed to the patriotism of the native soldiers, who, in May, 1857, replied by refusing to accept the famous "greased" cartridges, and in a few days the insurrectionary movement was ablaze in India. The massacre at Cawnpore sent a thrill of horror and indignation through the country, and Sir Colin Campbell (afterwards Lord Clyde) was ordered post haste from England to take command of the British troops. Naturally, our trade with India was disorganised; and, speculation having exceeded all bounds in America, the grave news from that country, combined with the outbreak in India, hastened on the crisis of 1857. Quite an epidemic of crime swept through England about the middle of the nineteenth century, and many names well known in the City were smirched, whilst even the firm of Overend and Gurney, whose credit was then at its zenith, were said to have compounded a felony in order to avoid a bad debt. Financial morality, which is at all times peculiar, was at this period at its lowest ebb. So small wonder that when the American banks failed by the dozen in 1857, a feeling of distrust should make itself felt in this country, which was then engaged in a fierce struggle in India. Merchants and houses engaged in trade with India and America began to fail, and in a very little while there was a run upon some of the banks. Then followed the collapse of the Borough Bank, and Dennistoun's of Liverpool. In Scotland the Western Bank and the City of Glasgow Bank put up their shutters; and the failure in London of Sanderson & Co., the well-known bill brokers, accentuated the grave condition of credit, forcibly reminded the public that the rotten state of the American railroads had ruined thousands of speculators in this country, and generated in the public mind a feeling of positive alarm. The result was a panic, which by 12th November culminated in a crisis. The country then looked to the Government and to the Bank of England. Both 1855 and 1856 were years of unusually high Bank rates, and during 1857 the demand for loanable capital became so pronounced that the Bank of England, in order to protect its dwindling store of bullion, had to raise its rate still further. The year opened with six per cent. In July it fell to five-and-a-half per cent., but by 19th October it had reached eight per cent. On 5th November nine per cent. was recorded; and upon the 9th of the same month it was hurriedly raised to ten per cent. Lombard Street had then practically arrived at the end of its available resources; and demand, of course, centred itself upon the bank which held the bankers' cash balances. The Bank of England, as usual in those days, was quite unprepared to meet a crisis, and made application for assistance to the Government. Had help then been refused, it must inevitably have closed its doors, for the reserve in its Banking Department on 13th November, 1857, had fallen to £957,000, while it was rumoured that, at the close of a particular day, the reduction was appreciably greater. In plain English, the Bank of England was practically broken. On 12th November the Government consented, for the second time since 1844, to the suspension of the Bank Charter Act; and when it became known that the Bank of England was in a position to increase its circulation to an unlimited extent, and to advance notes against the better-class securities, the nervous tension created by the numerous failures throughout the country instantly relaxed, and in a few days a comparative calm followed the storm. Indeed, before the close of 1858 the Bank rate was down to two-and-a-half per cent. The suspension of the Act during a crisis creates a market for securities at the Bank of England. Furthermore, at so critical a moment the Bank is the only market in existence; consequently those securities in which it decides to deal are alone saleable, and we know that it confines its advances solely to the so-called gilt-edged securities and to good bills. Of course, if the public only thought, it would instantly perceive that the more notes the Bank issues in excess of its authorised amount the less secure is its position, because the smaller is the proportion of gold in the Issue Department to its liabilities. But the British public is led; it does not think. If it did we should speedily be in the throes of a revolution. The public thinks the Government lends its credit to the Bank, but in reality it does nothing of the kind. It simply authorises the Bank of England to break the law, and to advance notes at its discretion. However, the credit of the Bank is so good that the public, seeing that it has the "moral" support of the Government, possesses absolute confidence in its stability; and though it trusts the Bank blindly and unreasonably, that institution has earned its gratitude upon more than one occasion, and its history, if full of mistakes, certainly entitles it to this confidence. Mention has been made of the failure of the Western Bank of Scotland in 1857. This institution, besides advancing indiscreetly at home, helped to finance the gamble in American securities; consequently, when the crisis occurred in the United States, the bank found itself saddled with huge blocks of unsaleable stocks and shares. Subsequent investigation disclosed a most discreditable state of affairs. In 1856 the Royal British Bank, after a short life of continual fraud, came to the ground; and in 1857 the public learned that the notorious Colonel Waugh had fled to Spain with considerable sums belonging to the Eastern Banking Company. A little later, when it was discovered that bank directors and auditors who, for a consideration, would attest such statements as those issued by the Western Bank, could be found in Scotland, the public came to the conclusion that a balance sheet is worth little more than the paper upon which it is printed; and a run at once began upon the rest of the Scotch banks, which promptly arrested the panic by guaranteeing the notes of the insolvent Western Bank of Scotland. The City of Glasgow Bank, though it closed its doors temporarily during this period of fraud and distrust, succeeded in weathering the storm, only to fail badly in 1878. The relations between England and France were severely strained in 1859. A plot was hatched in London by an Italian secret society against the life of Napoleon III., whose publication of a denunciation of British hospitality sent a thrill of passionate resentment through this country, which replied to his threat of invasion by the inception of the volunteer movement. The call met with immediate response, for nothing kindles enthusiasm so quickly as hate, and England, for the first time in her history, created an army of citizen soldiers. At the height of the frenzy there were ominous rumours, and for a little while a state of panic prevailed; but the alarm soon subsided, and the next year a commercial treaty was enacted with France. During 1862 loanable capital was cheap, and in July that year the Bank rate sank to two per cent., whilst at no time did it exceed three per cent. With money abundant, the promoter was soon in evidence, and the speculation fever once more took possession of the public, hundreds of companies being registered under the Companies Act of 1862 within the space of a few months, until dear money began to lessen the output of limited liability concerns and the energies of that arch-enemy, the promoter. In 1861 the United States was convulsed by civil war, which caused a cessation of production there on a large scale, and produced a cotton famine in this country. Lancashire, the centre of the industry, could not obtain fresh supplies of the raw material when the ports of the Southern States were blockaded, and early in January, 1863, hundreds of thousands of operatives were out of employment. Speculation instantly received a check, and the energies of the country were concentrated upon raising huge sums for the alleviation of the distress in Lancashire--for 500,000 unemployed workers might at any moment, should their attitude become menacing, prove a danger to the State. From 1863 to 1865 the Bank of England was undoubtedly face to face with a serious situation, and, for the first time in its history, its directors grasped the simple fact that only by maintaining a good reserve can the country be saved from panics and crises. The year 1863 was one of high Bank rates, and during the autumn of 1864 pressure upon the Bank's resources became so severe that a crisis was narrowly averted. Supplies of cotton from America having practically ceased, demand centred upon India, and the Bank of England, early in August, had to support a drain of silver thither to help pay for the cotton crop. On 4th August the Bank rate was raised to eight per cent., and again on 8th September to nine per cent., at which figure it remained until the 10th November, when it fell to eight again. The strain upon the Bank was severe, but the crises of 1847 and 1857 had taught their lesson, and by using the "Bank rate" with effect, the directors succeeded in keeping a sufficient reserve in the Banking Department. By about the middle of 1865 capital was cheap, but, towards the end of that year, a decided stringency manifested itself, and at the beginning of 1866 many companies which had been registered under the Act of 1862 failed. The banks, whose reserves were then much smaller than now, came in for their share of distrust, and the failure of a Liverpool firm for a large amount made the public uneasy; but when it was known on the 11th May that Overend, Gurney & Co. had closed their doors, the City was seized with panic, and streams of depositors rushed to Lombard Street to withdraw their money from the banks, which, in a very short time, were paying out at a rate it was impossible to maintain; and it soon became evident that unless confidence were speedily restored the banks must break. The Bank of England had to meet large demands from the provincial banks, for distrust was general throughout the country; consequently at such a moment the country bankers required their reserves of cash in their safes, so that they could immediately meet the demands of the more nervous of their customers should necessity arise. The Bank advanced its rate to seven per cent. on the 3rd May; to eight per cent. on the 8th of the same month; and to nine per cent. on the 11th; and, the pressure becoming more intense, application was made to the Chancellor of the Exchequer, with the result that the Bank of England was authorised to break the Act if necessary, the Government's condition being that the rate of discount should be ten per cent. while the Act was in abeyance; so, on the 12th May, the Bank rate was raised to ten per cent., where it remained until the 16th August following. By the 16th May the reserve was reduced to £731,000, but directly it became known that the Bank was in a position to advance notes against approved securities the tension relaxed, thereby proving that the public understood the cure as little as it did the disease--for it was an act of madness to make the run, and equally as stupid not to perceive that the issuing of unconvertible notes is at the best only a quack remedy. However, the remedy proved effective, and the result enables one to realise that a nation, like an individual, is the slave of habit. The history of the firm of Overend, Gurney & Co. makes sorry reading. Between this old-established discount house and the Bank of England there had always existed a spirit of rivalry; and when, after the crisis of 1857, the Bank stated its intention not to again assist the bill brokers during a time of panic, and only to make advances to them at those periods when the Government takes large sums off the market, a very bitter feeling sprang up between the discount houses and the Bank. Overends, determined to show the Bank that it was not omnipotent, allowed their account at the Bank of England to run largely into credit, and one day suddenly demanded three millions in cash. Their ruse failed. Indeed it was as stupid as the resolution which goaded them into making the effort; for, of course, were the Bank to refuse to assist the bill brokers during a panic, it would only be adding fuel to the flames and increasing its own difficulties. Small wonder then that so absurd a decree created intense irritation, for, upon examination, it is evident that the Bank of England is as dependent upon the bankers' balances in a time of panic as are the bill brokers upon the institution which holds them. Then what folly to advertise such a decision! Naturally, the Bank is not pleased at the thought that it must help its rivals over the stile, but the peculiarities of our banking system compel it to, whether it like the task or not. Therefore, it was an error of judgment on the part of the directors of the Bank to pose as the champions of the banking community, and to declare that the bill brokers must, in future, accumulate reserves of their own, when they knew quite well that the nature of their business utterly precluded such an attempt. During a panic the Bank of England can only save itself by advancing freely against certain securities and good bills. The credit so created, however, swells the bankers' balances in its own books, and consequently the amount standing to the credit of the bankers increases appreciably. But, at such a moment, the bankers call in large sums from the bill brokers, and, unless the brokers can obtain advances from the Bank of England against good bills and gilt-edged securities, they will be unable to satisfy the demands of Lombard Street. By declining to advance to the bill brokers, the Bank, in reality, would be refusing credit to Lombard Street (bankers' balances); and, as the Bank itself could not live were Lombard Street to withdraw its balances at so critical a time, it follows that it must lend to the bill brokers in order to enable them to repay the bankers. It simply dare not refuse to assist them, for, if it did, the banks might decline to support the Bank which left them in the lurch just at the height of the storm. The bill brokers (the outside market) come within our present credit system, and if, when a state of panic prevails, they were left to their fate, in every probability the system of which they form a part would collapse with them. The brokers may not be essential to the system, but it is always dangerous to "swop horses whilst crossing a stream." In 1865 Overend, Gurney & Co. converted their business into a joint stock company for the same reason that some private firms adopt the procedure--because their profits were decreasing--though this was not known until after the crash of 1866. During the panic of 1857 the Bank of England made large advances to Overends; but when, early in May, 1866, the firm again applied to the Bank for assistance, the request was refused. It has been suggested that the Bank's decision was prompted by malevolence, but at so crucial a moment the directors of the Bank would have hesitated to make a rod for their own backs, and, had they believed in the genuineness of Overends' application, they would have gladly granted the accommodation in order to spare themselves the panic which they knew must follow their refusal to assist a firm with liabilities of over £19,000,000. Moreover, subsequent events confirmed the judgment of the directors of the Bank of England. When the partners of Overend, Gurney & Co. discovered that their books were full of possible bad debts, they promptly converted the firm into a company, guaranteed the book debts, and appointed directors. Shortly afterwards it was noticed that the Gurneys were realising their property, and suspicion was at once aroused, for it was naturally assumed that they had incurred heavy losses. When, therefore, the company appealed to the Bank the next year, the directors were sceptical, for though Overends still retained the entire confidence of their country customers, there undoubtedly existed a feeling of distrust in the City, and the directors of the Bank of England shared in the opinion there prevailing. When the rash speculations of the partners were disclosed the public was loud in its abuse, and nothing short of a prosecution would satisfy it; and when, early in January, 1869, the directors of Overends were committed for trial on the gravest of charges, the crowd manifested its delight. But the comedy followed. The trial took place at the end of the year, by which time public opinion had completely veered round, and when it became known that the accused were acquitted, this same crowd cheered lustily. Small wonder that a Government, which must be well aware of the vagaries of crowds, should hesitate to conduct a public prosecution. The panic of 1866, though the suspension of the Bank Act immediately brought relief, dealt a fearful blow to credit, and the country recovered from the shock with painful slowness. Foreigners, alarmed by the disorganisation of the London money market, began to withdraw their capital, and the Bank, in order to check this drain of gold outwards, was compelled to keep its discount rate at ten per cent. for three weary months. By the middle of 1867 the Bank rate was at two per cent.; but even the company promoter had not the audacity to show himself, so depressed was the public spirit by the disasters of the previous year. The great railway companies, too, began to find themselves in financial straits, and their credit was so bad that they could only raise money on debenture stocks at high rates of interest, for the public then looked upon their ordinary shares as distinctly speculative holdings. As the railway directors neglected to borrow with the option of redemption at certain figures at a future date, it followed that, when their credit greatly improved at a later period, the companies were saddled with a huge drain in the shape of high interest on their debenture issues, whereas, had their directors exercised ordinary prudence, they would now be paying very much less upon their prior stocks, and consequently the dividends on their ordinary shares would be proportionately greater. Evidently, then, the interests of the shareholders were sacrificed to the holders of the debenture and preferred stocks. As the prior stocks absorb so large a share of the profits, and, moreover, as the amount so absorbed is practically always the same, whereas the revenue is variable, it follows that the distributions on the ordinary shares fluctuate considerably. This fact, of course, has not escaped speculators, who work out the ratio of ordinary share capital to total capital; and the smaller the ratio the more inconstant will be the dividends, and the greater the movement in prices. Investors know that, should the trade of the country be improving rapidly, a certain railway will earn more; and if its share capital ratio be small, then the increase in revenue will largely swell the ordinary dividends thereupon--so they speculate for a rise. The Franco-German war, which broke out in 1870 did not at first exercise any very great effect on the English money market, for though the Bank raised its rate to six per cent. on the 4th August that year, it was at two and a half before the end of September. Indeed, after the panic of 1866 down to the middle of 1870, scarcely a ripple disturbed the unusual calm of the money market, but the three crises since 1844 were largely accountable for that. They taught both Lombard Street and the Bank of England that caution is essential to the successful working of our banking system, and that fair reserves, however great the loss of interest incurred thereupon, are indispensable to a banker. The result of these bitter lessons may be read in the comparatively peaceful history of English banking since 1866. In 1870 specie payments were temporarily suspended by the Bank of France, and the European demand for the precious metals had to be met by the Bank of England. A much larger amount of foreign capital, consequently, was deposited in London, which then became the Clearing House of Europe, and the accumulation of so much foreign money unquestionably made the money market more sensitive, and increased the responsibilities of the Bank, whose store in the Issue Department was then peculiarly exposed to the danger of a drain outwards. The Franco-German war ended disastrously for France in 1871, and the vanquished had to pay a huge indemnity to the victor. France paid considerable sums to Germany by bills on England, and although Germany employed a certain proportion of the capital so obtained in the London money market, it withdrew large sums in gold, which were required for purposes of currency reform. During the latter part of 1872 the Bank rates were decidedly high, and in November, 1873, nine per cent. was recorded for about two weeks, but by December it was down to four and a half again. The Bank, no doubt, had its anxious moments during this period, for the larger the drain outwards the more dependent would be the bill brokers upon it, and the directors could not refuse to increase their advances to the brokers, because, had they done so, there would have been a panic at once. We can now see distinctly how our system works. First, we get the bill brokers or middlemen, who, from the nature of their business, cannot afford to keep reserves, because their margin of profit is so small; and secondly there are the bankers, who keep their reserves with the Bank of England, which is thereby placed, so to speak, in the centre of the money market. The Bank, after it was stripped of its monopoly of joint stock banking, failed for a time to understand its new environment, and it would have closed its doors three times since 1844 but for Government intervention, viz., in 1847, 1857, and 1866. However, when we remember that its directors were merchants, not trained bankers, and that the Bank had to adapt itself to entirely changed surroundings, this result is not remarkable. So little acquainted were the directors with the laws of banking that they actually believed the Act of 1844 would prove a panacea for all kinds of financial troubles; but their eyes were opened very widely indeed in 1847, and they gradually came to the common-sense conclusion that "the higher the ratio of reserve in the Banking Department the smaller is the danger of disaster to the Bank and to the country." During 1866 the Bank was fairly well prepared, and, for the first time in its history, it met a panic in a scientific or common-sense manner, and advanced without hesitation to all would-be borrowers whose securities were good. The greatest danger the Bank has to face is the suspension or stoppage of the credit machine of which it is the heart, for if the progress of that machine be arrested, then the trade of the country must also stop, and England will be bankrupt. So long as the machine can be kept in motion a catastrophe is impossible, and experience has taught the Bank that, during a period of pronounced distrust, this can only be done by advancing liberally against certain securities, and by a skilful use of the "Bank rate." The whole credit machine must work smoothly, and it would be madness, at such a moment, for the Bank to attempt to leave any part of the machine (the bill brokers for instance) to its fate. This is now fully recognised, and consequently a better feeling exists between the various divisions of the money market. The credit machine is kept in motion by the workshops; therefore, during a panic money has to be advanced to discount good trade bills in order to support the workshops, for if a rumour got about that the banks were refusing the acceptances of strong firms, the pressure to borrow would immediately increase, thereby adding a fresh danger to the situation, and causing nervous depositors to rush in a body to the banks for their money. It follows, therefore, that in order to arrest a panic, and to prevent a dangerous run upon their resources, the banks must lend freely to strong clients. In a time of financial stress the weak go to the wall, for finance is no exception to the rule that only the strong can live when a storm bursts and causes a struggle for existence. There is no room for sentiment at such a moment. The fight is bitter and to the finish. Sentiment comes in afterwards. This state of affairs is one of the curious products of modern civilisation, and, if you want to alter it, you must first alter human nature, which changes strangely little as the centuries roll on. At first sight these sudden advances seem highly imprudent, because the banks are parting with their resources, but unless the workshops are assisted the banks _must_ break: whereas, by advancing liberally on the best securities at high rates of interest, the dangerous element is speedily weeded out, and, provided the reserves of the banks are fairly large in proportion to their liabilities, a healthy reaction is practically certain to assert itself long before the end of their lending power is reached. The Bank, when it advances, of course creates credit in its books, and so adds to the resources of Lombard Street. The relief thus obtained is artificial, and, were it intended as a permanent cure of a disease, it must in the end only aggravate the malady. But it is temporary assistance during a trying time that the workshops require, and it is just this which our modern credit system, when skilfully administered, can give admirably. In fact it possesses the very machinery for the purpose. This sudden demand for additional credit (not specie) during a period of pronounced distrust is fortunately of short duration, and the Bank is, therefore, only called upon to make large loans for a short time, as, though the depression following a panic may prove lasting, the acute stage which the Bank has to face is soon over. The dangers of our credit system are apparent to everybody; but when critics point to the panics which have occurred since the Act was passed, and make deductions therefrom to the effect that the Bank may find itself in a similar plight should another such whirlwind develop, they usually forget that, though the same danger exists, our banking companies are now much more prudently managed, and that the directors of the Bank of England, having the misfortunes of the past to guide them, are thoroughly acquainted with the delicacy of the machine they manage, and are, consequently, less liable to err. We have seen that the joint stock banking movement began in 1826 under conditions which were far from favourable, and the companies, like the Bank of England itself, having to learn their business as the movement progressed, naturally committed many blunders; but when the dangers of banking were better understood failures became much less frequent, and after 1866 they were few and far between. The credit of the joint stock banks vastly improved in consequence, and confidence in their stability soon began to take the place of distrust. But in 1878 the failure of the City of Glasgow Bank and of the West of England Bank, together with some half-dozen private bankers and banking companies, undoubtedly revived old prejudices and created a feeling of unrest among depositors and shareholders. The City of Glasgow Bank, it will be remembered, was in trouble during 1857, but in 1878 both its customers and shareholders had reason to regret that it ever opened its doors again, for the gravest irregularities were disclosed when its affairs were examined, false balance sheets having been certified by auditors and directors during a period of over four years; and once again the public was startled out of its sense of security by the discovery that some bank directors and auditors were not less peccant than the majority of the human race when hazardous speculations landed them in financial difficulties. The directors of the City of Glasgow Bank finding themselves out of their depth, clutched at the proverbial straw, and, like a weak individual who starts with the best of intentions, they were speedily sucked into the vortex of crime. By the Act of 1845 the directors were bound to hold gold against any excess in the amount of the bank's circulation fixed thereby, but they overcame this difficulty by the simple expedient of making false returns to the Government. Having once crossed the line which separates the sheep from the goats the rest was easy. With an utter disregard for the interests of the shareholders, the directors advanced huge sums to firms in which they were pecuniarily interested, and, as these firms did badly, they were compelled either to bolster them up with additional loans or to allow them to fail. They chose the latter alternative, and, as might have been expected, the bank's assets rapidly dwindled, millions of pounds in the shape of bad debts being disguised on the right hand side of the balance sheet as cash in hand, Government securities, and so on. The business of the bank soon degenerated into a mere gamble, and during the latter part of its career the institution was only kept in existence by the continuous perpetration of frauds. Of course the longer the game (it can be dignified by no other name) continued the more desperate were the efforts it called forth, and just before the end the directors hit upon the brilliant idea of conducting a big gamble in Australia, in the vain hope that a decided success would obliterate the mistakes of the past; but about this time rumour was active, and when it was noticed that the bank's acceptances were being hawked all over the City, holders of its paper became suspicious. The bill brokers naturally do not like putting all their eggs in one basket, but endeavour to get as many good names as possible, so that, should a particular firm meet with misfortune, they may be in a position to bear the loss. When, therefore, the City of Glasgow Bank's paper was offered freely, they refused to place more of its bills in their cases, and, inquiries concerning the bank being made in consequence, the end soon came. Though the revelations which followed generated a feeling of intense nervousness among bank shareholders and depositors both in Scotland and this country, and undoubtedly caused a slight panic, the country was spared a crisis. The Scotch banks, in order to prevent the run extending to themselves, encashed the notes of the delinquent institution, and advanced liberally to those persons whose money and securities were held by the City of Glasgow Bank. In this manner a serious panic was averted. The Bank of England raised its rate immediately danger was threatened, and on the 14th October, 1878, the rate touched six per cent., but it fell to five per cent. in November, and money was exceptionally cheap during the next two years. The West of England Bank had also advanced its resources in a reckless manner, and it failed badly in consequence; but the Scotch scandals were not repeated, and the public gradually regained confidence in the banking companies. When it was clearly seen after the failure of the Glasgow Bank, how easily a large bank, unless it be most cautiously and prudently managed, can ruin its members and customers, the public hesitated to hold shares in an unlimited banking company. For a time the prices of bank shares fell considerably, and fiction became tediously full of heroines and heroes who lost their fortunes by holding just one share in the Glasgow Bank. It was the "just one share" that proved so thrilling, and accentuated the sadness and the danger of possessing shares in an unlimited bank. The risks of a banking business were discussed on every side; and, after this failure, the unlimited banking companies took steps which enabled them to affix the desirable word "limited" to their registered names. From the time of the failures of the City of Glasgow Bank and the West of England Bank until 1890, when the Baring crisis suddenly opened the eyes of the public to the dangerous gamble which was taking place in South American securities, the money market enjoyed a period of comparative calm. Speculation since 1885 had increased in volume, and the prices of securities steadily rose; but early in 1890 it became apparent that continuous speculation had inflated prices and created a situation which could not last. The Bank rate during the autumn of 1889 was exceptionally high, and remained at six per cent. from 30th December, 1889, to 20th February, 1890, when it gradually descended, but this fall only proved the lull before the storm, which raged furiously in the November following. England has always speculated largely in both North and South America, and the result has almost invariably been a panic. In 1890 it was the Argentine Republic which was to prove an Eldorado for the British investor, and Baring Brothers were so convinced that this wonderful land must prove a veritable gold mine that they practically staked the existence of their firm upon it, but Argentina sadly disappointed its backers. Having staked their all and lost, there were many who thought that Barings should have paid the penalty of their mistake, for Fate certainly was not so kind to some of the smaller losers in the gamble as was the Bank of England to Baring Brothers. In June the Buenos Ayres Western Railway was unable to raise capital in this country; and when at a later date Baring Brothers failed to place a new Argentine loan, the worst was feared. Earlier in the year the United States had increased its circulation of silver currency, thereby creating a sudden demand for that metal and a proportionate rise in those securities upon which the interest is payable in silver. A fall soon followed; and when it was found that the Argentine Government was in straits, Stock Exchange settlements became difficult. The banks, which had advanced huge sums to the Stock Exchange on American securities, increased their margins directly the markets looked dangerous; consequently high rates of interest, together with the rapid fall in South American securities, made "carrying over" in the House an expensive operation. Speculators became alarmed, and sold out at panic prices in order to cut their losses, and on 7th November pressure upon the Bank of England became so great that the rate was raised from five to six per cent. Lord Revelstoke, who was a partner in the firm of Baring Brothers, was also a director of the Bank of England, and, finding that his firm was in difficulties, he disclosed his position to the Bank directors, who, when they heard that Messrs. Barings' liabilities to the public amounted to over £28,000,000, felt that even the Bank of England could not afford to guarantee so large a sum; so, after much deliberation, it was decided to invite the co-operation of Lombard Street in the bolstering up of Barings, and, for the first time in its history, the directors of our large banking institutions met the directors of the Bank in their sacred parlour to discuss what steps should be taken in order to avoid a disturbance of credit which, should the suspension of Barings be announced, would probably produce a crisis even more disastrous than that caused by the Overend and Gurney crash in 1866. The resources of Lombard Street combined are infinitely greater than those of the Bank, which, we have seen, largely draws its own power therefrom, and the directors of the Bank of England, in consulting with the directors of the joint stock banks, proved that they thoroughly understood the constitution of the money market. Moreover, this new step created a precedent which bound the whole market more closely together, for each division clearly recognised how essential it is that the great machine should work smoothly. This can only be accomplished by the best of feeling existing between its constituent parts, and the wise step taken by the directors of the Bank in November, 1890, undoubtedly generated a feeling of sympathy which had formerly been noticeably absent between the various sections of the money market, and which augurs well for the harmonious working of the system in the future. Such sympathy may be the outcome of enlightened selfishness, but it is none the less valuable. The directors of the joint stock banks, when the position of Baring Brothers was revealed to them, instantly recognised the danger of the position, and, as their advances to the Stock Exchange were considerable, they were naturally anxious to prevent a catastrophe which would create a panic in the House, and the end of which it was impossible to foresee. Barings, who are financiers in the English sense of the word, not bankers, had at the worst only been guilty of imprudent speculation, and, as all inquiries were answered in the most straightforward manner, Lombard Street was as anxious as the Old Lady herself to assist Baring Brothers over the stile. Undoubtedly Lombard Street would have liked to make an example of the firm that was caught short of cash, but it was afraid to leave it to its fate, because it knew that discrimination is not one of the characteristics of excited depositors, and that, were Barings to close their doors, the credit of Lombard Street would next be questioned. The outcome of the meeting at the Bank was that the Bank of England agreed to make advances to Baring Brothers in order to enable them to meet their liabilities as they matured, and the large banking companies, on their side, guaranteed the Bank against loss to the extent of £15,000,000. Immense sums had been invested in South America, and when it was rumoured that the wealthy firm of Barings was tottering, Argentine securities were practically unsaleable on the Stock Exchange, where a state of panic prevailed. For a few days the wildest rumours were noised abroad, and the tension, just at the height of the panic, became so acute that even the Consol market was idle. The market then turned in despair to the Bank, which was compelled to borrow £3,000,000 from the Bank of France as a precautionary measure, and also to accept help from the Russian Government. The British Government, fully alive to the gravity of the Bank's position, promised to suspend the Act in case of need; but when it became known that Barings were to be supported, and that the Bank of England was lending freely on approved securities at high rates of interest, confidence was restored, though a few days earlier it had looked as if a dangerous crisis were imminent. The Bank Act, however, was not suspended, but it is difficult to say what might have happened had not the Bank of France come to the rescue, for the gold advanced by that institution at so awkward a time doubtless tended to greatly alleviate the feeling of apprehension which existed in this country, and which, at any moment, might have overcome restraint. The Bank rate remained at six per cent. until 4th December (a period of twenty-seven days), when it was reduced to five per cent.; for the high rates ruling in the market attracted gold to this country, and increased the reserve of the Bank of England beyond the apprehension minimum, thereby enabling that institution to make the change in question. By the middle of the following year (1891) the Bank's rate of discount was down to two-and-a-half per cent.; but confidence was not restored for some considerable time; and we all remember the deadly dull years of 1894 and 1895, when it was predicted that Consols would never again fall below 100. The financial prophets and the weather prophets are generally wrong, but though we have acquired the habit of tapping the glass each morning, a prudent man carries his umbrella all the same. The directors of the Bank of England, when they were informed of Baring Brothers' position, acted with great tact and ability. They did not hesitate to assist everybody who possessed good securities, and when it was found that loanable capital was obtainable, the alarming symptoms which were at first in evidence soon subsided. Whether or not the Bank were sufficiently prepared at the time is, however, a matter of opinion. The directors certainly began the year badly, for the ratio of the reserve in the Banking Department was under twenty-eight per cent.--a dangerously low proportion in these times, when huge sums of foreign capital may be suddenly withdrawn from the market at the least sign of discredit. Nor are high rates of discount always effective in immediately attracting gold to the Bank, as the Bank of France, should it desire to retain its bullion, can always charge a prohibitive premium on its gold. Certainly, since 1890 the Bank of England has maintained larger reserves, and the Baring panic unquestionably proved that such a step was necessary. It would seem that the panic of 1890 was the result of a Stock Exchange gamble, which was only rendered possible by the large loans on securities made to members of the House by the banks. The Baring incident brought matters to a climax, and Lombard Street, which was more involved in the speculation than many persons imagined, had to save both that firm and the Stock Exchange in order to avoid a crop of bad debts, which, with numerous failures, and a far greater drop in the prices of securities, would have inevitably resulted. Mr. Lidderdale, who was Governor of the Bank during this period, acted with great energy, and after the danger was passed congratulations were showered upon him from every side. The Stock Exchange presented an address to Mr. Lidderdale, and in making the presentation its spokesman said: "If the Bank had not acted in the way it did, a great disaster would have befallen the mercantile community." Yes, and that disaster would have been largely caused by speculation on the Stock Exchange. Further, had not the directors of the Bank met this incipient panic in a scientific manner, and used their power as precedent dictated, members of the House would have failed by the dozen. One is forced to the conclusion that Lombard Street and the Stock Exchange had a lucky escape, and that the "members of the mercantile community" were the unfortunates who, after years of toil, had to wipe out the deficit. Now we come to the bright side of the picture. Later on the business of Baring Brothers was converted into a company, and in 1895 it was definitely announced that the assets of the firm had been liquidated without any loss whatsoever to the guarantors. Baring Brothers & Co., Limited, now publish a strong balance sheet, which entitles the company to a place among our well-managed institutions, and so short is the memory of the public when things financial are in question, that the panic of 1890 is, if not quite forgotten, at least regarded as ancient history. Indeed, the public hardly seems to realise that, in November, 1890, the monetary situation was so acute that a quickening of the public pulse would probably have resulted in one of the most dangerous crises the country has ever been called upon to face. After the Baring crisis the market was unperturbed for a little while, but in 1893 many of the Australian banks found themselves in difficulties, and as the people in this country, tempted by the high rates offered at the London offices of the Australian banks, and by their agents on this side, had deposited largely with them, a very bitter feeling soon manifested itself. Australia, like South America, was to prove an Eldorado for the small investor, but the pace was forced, and the reaction came in 1893, when many of the banks suspended payment. Even now some of the Australian banks in London are not any too strong, and discrimination is certainly desirable. On 9th October, 1899, the Boers issued their famous Ultimatum, to which they immediately received an answer that was brief and unmistakeable; but, unfortunately, the pen of the Government at first proved mightier than the sword, and by 3rd November White was shut up in Ladysmith. Then followed the failures of Methuen and Gatacre, and on 15th December General Buller was repulsed at Colenso. Thoroughly roused, the Government sent out Lord Roberts and Lord Kitchener. On the night of 6th January, 1900, the Boers made a desperate attempt to take Ladysmith, while Buller again failed to relieve the town on the 22nd, and did not enter it until after Cronje was brought to bay at Paardeberg at the end of February. This period of disaster cast a gloom over the whole nation, which grew sullen and determined, and, when at last the tide began to turn, the sudden lifting of the burden immediately metamorphosed a silent depressed crowd into a cheering multitude, which on Mafeking day turned London into a veritable pandemonium; but the depression caused by unpleasant surprises was intense, and, therefore, the joy at finding the incubus gone was the more irrepressible. Hence the disorderly scenes upon the day in question. A reaction after the period of suspense was inevitable, and the greater the gloom the more violent would be the excitement that followed when the first ray of sunshine pierced the mist. Yet how little was this understood at the time. That financial barometer--the Bank rate--began to reflect the political situation early in October. Our state of unpreparedness was a by-word on the Continent, and when in September, 1899, the Boers displayed an unyielding attitude, which was at first mistaken for bravado, our overweening confidence in the British soldier blinded our eyes to the imperfections of our fighting machine. The Continent, which was better informed than the British Government, believed that the Boers were determined. On the 3rd October, when the Free State burghers occupied Van Reenen's Pass, the Bank advanced its rate to four-and-a-half per cent.; on the 5th October the rate was five per cent., and on the 30th November six per cent., where it remained until the 11th January, 1900, when five per cent. was recorded. But if the Government was unprepared the Bank of England was not, and from start to finish, by a judicious use of its rate of discount, an adequate supply of bullion was maintained in the Issue Department. Long experience had taught its lesson, and our financial machine, which was in a good state of preparedness, worked without a hitch. Who can doubt that if our fighting machine had been as ably handled, it would have done its work well from first to last? There is also another point which is well worth attention. If our banks neglect to keep good reserves, a panic results immediately there is any unusual demand upon their resources, and the cost of a panic soon convinces their directors that it is cheaper to be always prepared. Will the expenditure of some £230,000,000 teach the Government the same simple truth? If we must have an army, it is madness not to keep it--as our banks are kept--ready. Mr. Kruger and his advisers did not consider the latent potentiality of the British fighting machine. They ascertained its state of preparedness to strike at a moment's notice, and, seeing that it was unprepared, the Boers wisely struck the first blow, hoping to drive the English into the sea before the machine could be adapted to a new environment. On the other hand, they failed to realise the resources of the Empire. Had the Boers believed that the British could land an army of even 150,000 men in South Africa, in all probability there would have been no war. The Government, which was caught unprepared, had to pour out money like water, because it had neglected to take one of the simplest business precautions--to keep the army ready. On 31st May, 1902, peace was declared, and now the country has to face a domestic problem. In 1899 trade was good, and in 1900 the prices of commodities were at their zenith; but during 1901 a reaction set in, and at the present time trade is certainly not active. Reservists are arriving from South Africa in large numbers; and, as the labour market is already depressed, a number of them are sure to experience considerable difficulty in finding employment. War is certainly not a business that civilises, and if a man has once tasted blood, in however just a cause, it is difficult to believe that life will seem quite so sacred to him again. Should the times become really bad, these men who have returned from the front, and who cannot again find a place in civil life, will turn instinctively to the weapons upon which they have learned to depend. Consequently, should there be a severe depression in trade, an epidemic of crime is one of those possibilities which may send a thrill of horror through the country. Since September, 1899, the money market has certainly had to contend with great difficulties, and a system which has proved itself more than equal to the strain surely cannot be so undesirable as certain critics would have us believe. Again, the more the public understands the system, the less is the danger of panic; for it must be apparent to every man who reads this book that, if he study his own interests, he will select a strong bank, and, having taken that precaution, he will carefully refrain from rushing for his deposit during a time of stress. CHAPTER XVI. The Banks and the Public. We have seen that the history of the Bank of England may be divided into two periods. From 1708 to 1826 the Bank enjoyed the monopoly of joint stock banking in England. After 1826 it had to adapt itself to a constantly changing environment. England, in fact, outgrew the Bank, just as the financial world has outgrown London. The directors of the Bank of England were City merchants, whose ideas usually run in a particular groove. It is not, therefore, in the least remarkable that they stuck to old customs and neglected new opportunities. The directors of the London and Westminster Bank made the same mistake. So did those of the Union Bank of London, the London Joint Stock Bank, and one or two others, simply because their training was of the City: that is to say, like the streets around the Bank, narrow. To a very great extent the Bank of England is dependent upon the bankers' balances, for, unless it held them, it would not be able to finance the Government. If its directors had, however, thoroughly understood the movement of 1826, the Bank would now be a much more independent institution, and would be a power in every county in England and Wales. In 1826 the Government expressly desired the directors of the Bank to open country branches, and by 1830 it possessed eleven offices in the large provincial towns. But the innovation was not encouraged by those in authority, and to-day the Bank of England possesses only nine country and two Metropolitan branches. Unquestionably a golden opportunity was neglected, for, had the directors decided to open in the large provincial towns, Bank stock would probably be worth over five hundred at this moment. At first the joint stock bank movement was neither popular nor successful, but nobody questioned the credit of the Bank of England; and if that institution had quickly met the wants of the country by opening branches in the towns, it could have had the pick of the provincial business, for everybody, including both commercial firms and the leisured classes, would have been anxious to deal with a bank which was absolutely above suspicion. And who would dream of making a run upon the "Government" bank? The Bank would gradually have accumulated vast deposits, which would have made it independent of the "bankers' balances"; but the ground is now covered with banking companies, and the Bank of England's opportunity is gone, never to return. At present it is a great bank of discount. Had it farmed the provinces in earnest, it would have become a great deposit bank, deriving its power from its depositors and the Government account, instead of from the Government and the bankers, as it now does. But its directors were not trained bankers, and they failed to realise the important part that branches or feeders were to play in the new system, consequently, with the huge capital of the Bank, large dividends on its stock are now out of the question. Our present system is, after all, the result of chance as well as of skill. It grew. Further it committed all the follies of youth and inexperience. Then, again, at the beginning, it was as a house divided against itself, and consequently upon more than one occasion it fell, for a banking system can only be worked successfully when all the strong members are pledged either to stand or to fall together. Indeed, our system would be considerably strengthened if the great banks were in closer touch with the Bank of England. Some few years ago, when there was a somewhat bitter feeling between Lombard Street and the Bank, it was often suggested that were each bank to keep its own reserve of cash the rate of discount would be more stable; but, in the event of such a change, the banks would undoubtedly have to maintain increased reserves, and a greater proportion of their resources would consequently be non-productive. As they would then have less capital to lend, it also follows that, even if rates in the open market did fluctuate less, the average rate of discount paid by the public would be higher, because there would be less capital in the London short loan money market to meet the demands of the bill brokers and stockbrokers. On the other hand, if the banks realised their investments in proportion as they increased their reserves, and so maintained the same amount of capital in the London short loan fund, their own profits would decrease; and the bank proprietors are not philanthropists. In the one case the public would suffer, and in the other the banks themselves would lose, whilst in neither instance is the advantage to be gained at all proportionate to the risk incurred by a sudden disturbance of credit. Our present system, with all its imperfections, has gradually grown up around the Bank of England, and if Lombard Street were to decide to keep its own reserve, the result would be confusion, and confusion might be followed by panic--so great is the faith of the public in the Old Lady, whose history entitles her to both consideration and respect. The change might, or might not, result in a run upon Lombard Street; but the Bank of England, whether or not the money market were disorganised, would not lose the confidence of the nation, which is convinced that the Bank cannot fail. Lombard Street, we may rest assured, would not risk so drastic a change. It may be urged that, were the banks to keep their own reserves, the Bank could not finance the Government, which would then have to borrow to a greater extent in the open market; and perhaps such would be the case. But though the Bank of England is at present largely dependent upon the "bankers' balances," and upon the power derived from its position in the centre of the system, it must not be assumed, even if the banks could agree among themselves as to the ratio of cash each should hold, that the Bank would be compelled to bow to their decision. As a matter of fact, such a decision on the part of Lombard Street would change the Bank of England from a discount bank into a deposit bank--a metamorphosis which Lombard Street could not face with equanimity. The Bank, whatever arrangements it may make with its own customers, does not at present compete against Lombard Street for deposits at interest; but were the bankers to withdraw their balances, the Bank would be compelled to appeal to the public for deposits, and who can doubt that it could not attract as much capital to its vaults as it required? The Bank would only have to make its rate of interest sufficiently attractive, and the public would rush to it with deposits. Where would Lombard Street be then? Unless the Bank rate be unusually high, the banks allow one-and-a-half per cent. below it upon money left at interest in London. The country deposit rate, which is somewhat higher, is affected to a certain extent by competition in the provincial towns and cities. But the Bank would not confine its efforts to London if its hand were forced. It would offer high rates at its branches, and might even open fresh offices. The bankers' deposit rates would then be forced upwards in order to arrest the drain from themselves to the Bank of England. No; Lombard Street cannot play fast and loose with the Old Lady; and, if certain critics will reflect, they will see that the Bank has less to fear from a change in our present system than have those who occasionally threaten her. Her position, were the banks foolish enough to withdraw their balances, is not quite so hopeless as it is sometimes made to appear upon paper. Indeed, the better the understanding between the Bank and Lombard Street, the safer is our "one reserve" system, and consequently the less liable is the country to financial crises--for it is only by the united action of all the great banks that the situation can be saved in times of stress. This was clearly proved during the Baring scare of 1890. The "clearing" bankers from time to time fix the deposit rate for London by the Bank rate, and though their country branches are not bound by their decision--which is advertised in the newspapers directly a change is made--the country deposit rate fluctuates with the Bank rate, though, as a rule, it neither falls so low as the London rate when capital is cheap, nor advances so far when it is dear. Further, the rates charged for loans and advances should be regulated to a certain extent by the Bank rate. However, that is a question which need not be entered into here. Should the bankers decide to keep their own reserves, it is evident that the Bank of England's rate of discount would immediately cease to be a representative rate, and that a powerful rival, with a great history and a clean record, would at once begin to compete against the bankers for both deposits and advances. Were the Bank of England, so to speak, to decide to remain outside the system, Lombard Street could not even fix a minimum deposit rate for London, because the Bank, if it required capital, would bid against its rivals, and would soon obtain all it needed. Instead of being more stable, rates in the open market would move up and down with startling suddenness. Would-be borrowers, puzzled by such irritating movements, would soon grow nervous, for the prices of commodities would fluctuate too, and everybody would be afraid to make large purchases. The closer one examines the question, the more absurd appears the suggestion of a split between the Bank and our great joint stock banking companies; and the only wonder is that any person with the slightest sense of proportion can seriously advance so dangerous a proposition, which that friend of our youth, "Euclid," would have at once pronounced "absurd." Custom has placed its seal upon our banking system; and the person who is rash enough to break that seal may discover that he has released new forces, which, though theory plainly demonstrates that they will act in a certain direction, are pretty sure to make their way through an unsuspected flaw which offers less resistance. A system which has been over two hundred years in the building cannot be changed in a day--especially a system which, even if it be not understood, has entered into the daily life of the people. It is because the system is not understood that the change would be so dangerous--so irritating. It would be asking the British public to think, to change its habits, to suddenly adopt new ideas; and as that mysterious body has never yet been educated up to thinking for itself, it would be found that it would kick against a new system like the stubborn donkey it is. Here is the real danger. The change, if the public would adapt itself to it, might prove beneficial--but the public would not; and as even its advantages over the present system are doubtful, where is the practical banker who would suggest the move? His one aim is not to disturb the money market, and for that reason alone he would hesitate to remove the Bank of England from its position in the centre of the system; but when we remember that the Bank, by accepting deposits, could probably beat Lombard Street at its own game, the change in question need not be discussed seriously. There is one other phase in modern banking which, perhaps, calls for notice, and that is the fierce competition for safe business taking place between the banks themselves both in London and the provinces. Most of our large towns and cities are overbanked. Consequently, the public has a choice of many markets, as it were; and, quite naturally, it tries to lend in the dearest and to borrow in the cheapest. It may be asked: How much longer will this state of affairs exist? And the answer is: Just so long as the banks decide that it shall; and not a day longer! The better the risks of banking are understood by the public the more difficult will it be for a weak bank to attract custom; and as the smaller banks, especially in the manufacturing centres, are unable to obtain sufficient deposits to meet the demands for advances, it follows that, when their loans grow out of all proportion to their resources, they are compelled to amalgamate with a large institution possessing numerous branches, and therefore in a position to collect huge sums of loanable capital, and distribute it just where it is wanted. For instance, a large bank collects very much more capital in certain districts than it lends therein; but at branches situated in busy manufacturing cities the demand for capital, especially when trade is brisk, approximates much too closely to the sums collected at those branches to be compatible with sound banking. However, the bank has accumulated more than it requires in other towns, and is therefore in a position to transfer the surplus to those places where demand is strong, and, at the same time, to maintain a good ratio of liquid assets to liabilities, whereas a local bank in a busy centre can often only meet the requirements of its customers by advancing to a dangerous extent. The directors of such banking companies are beginning to realise this danger; and fearful that one day they may be caught short of cash, the smaller joint stock banks are gradually being absorbed by the greater companies, whose numerous tentacles enable them to distribute their capital evenly throughout their system, and to maintain fair cash reserves against their liabilities. As the small banks disappear, competitors are removed from the market; and there is every probability that banking in this country will by-and-by be in the hands of a few large and powerful banking companies. The public could not resist the banks were they to unite against it. Already the "clearing" banks have fixed the deposit rate for London, and it is only one step farther to declare the minimum rate at which they will advance--for what resistance can the public offer to a combination with more than £910,000,000 in deposits alone behind it? Were the banks to hold a conference, and to decide that competition must be kept within bounds, the public would not have a voice in the matter. The English banks, like those of Scotland, would, after having come to some arrangement among themselves, meet from time to time in order to fix the minimum rates of interest and commission, and their customers would either have to pay those rates or else obtain accommodation outside the confederation. Of course, all the banks would have to close up their ranks before this arrangement would be possible, and, at the moment of writing, it seems improbable that certain companies, which make a business of competition, could be persuaded to come inside. So long as the banks are divided the public will be able to drive bargains with them, but, directly they fall into line, their rule will begin, and the quicker the smaller companies disappear the nearer the reign of the banks approaches. Seeing that our banking system can only work smoothly so long as both Lombard Street and Threadneedle Street work in harmony, it follows that in time the link which connects the large banking companies will become stronger, and the relations between them pleasanter, because, in business as elsewhere, friendship is centred in the head rather than in the heart. The banks must draw closer together, because, if they do not, their system is unworkable; and, as they are now compelled to adopt certain precautions in order to protect themselves against panic on the part of their customers (who in that respect are their enemies), it is only natural that they should take steps to put an end to excessive competition, which weakens their position and prevents their acting together at a moment when united action alone can restore confidence in their ability to meet their liabilities. We all know the stale apothegm: "Self-preservation is the first law of nature." It is the religion of the world. We can see the law at work among our friends, but, being polite, we refrain from comment--though if we be wise, we reflect; for here is the great unpreached gospel which governs the actions of men. Self-preservation clearly dictates that the banks cannot afford to allow competition among themselves to weaken the system upon which their safety depends; and, should the danger become pronounced, they are certain to combine against the public in order to at least agree to certain minimum rates below which none will do business. It may be said: You yourself were the first to point out that certain customers are in a position to make terms with the bankers, and to advise them to do so. That is true enough; and so long as the banks are divided amongst themselves this is possible; but it by no means follows that, because the customers can make certain bargains this year, they will be able to make similar arrangements next, for the banks have their remedy, and when the right time comes they will not neglect to take it. We have dissected that complex machine, which is called the Money Market, and of which the Bank of England is the heart. As each unit is dependent upon the strength of the whole, no bank should be allowed to trade upon the credit of the rest, for obviously it cannot exist outside the system during a time of stress unless it possess an adequate reserve of cash. Therefore each unit ought to bear its fair share of the burden when the sun is shining, and, if it refuse, it should be made to take the consequences when the storm bursts. The closer our banking system is examined the stronger becomes the conviction that the interests of all the banks are identical, and that, therefore, if banking is to be conducted in this country with comparative safety, every bank should be compelled, either by the law of the land or by public opinion, to keep a fair reserve in legal tender against its liabilities. Further, the true interests of the banks are the same as those of the public--for the good business man is always a cautious man, and if he takes the trouble to study the risks to which a banking business is exposed, he will hardly care to place his money with a company unless it be well prepared to face those storms to which its environment peculiarly exposes it. Under our one reserve system the banks must either stand or fall together during a crisis. The system, therefore, requires the support of all; consequently, the duties or obligations of each bank should be clearly defined, and this can only be done by an Act of Parliament or by an understanding between the banks. The closer the banks draw together the safer is our system of banking. CHAPTER XVII. Bank Stock. When the trade of the country is prosperous, we expect to see banking companies paying high dividends, because rising prices stimulate borrowing on the part of the public; and, consequently, as the resources of the banks are limited, the increased demand for loanable capital sends up rates, with the result that distributions are enhanced, and that the prices of bank shares advance in sympathy with improving dividends. We all know that there is a link which binds industries together, and that a depression in one trade, if it prove lasting, must communicate itself to the rest. Nor is this movement confined to any one nation. Therefore, when we hear that a depression exists in Germany or in any other great manufacturing country, it is a matter for regret rather than otherwise, because the goods of that country are almost certain to be exported here in large quantities. If there be stagnation in Germany, then money will be cheap in that country, and commodities will be cheap too. Manufacturers, therefore, will be able to obtain better prices in foreign markets; consequently, German exports will increase, and prices will soon begin to fall in England. Again, depression in the States speedily makes itself felt in the English markets, which become glutted with American goods, with the result that production lessens at home, and times gradually become, as we colloquially say, "bad." But there is one factor with which we have not reckoned, and that is time; for though after a period of prosperity prices generally fall suddenly--as, for instance, during 1901--it usually takes two or three years before production is again in full swing. In these days, when commercial ties bind the whole world so closely together, one nation cannot afford to rejoice at the misfortune of another; and when this fact is more clearly seen and is better understood, possibly large standing armies will become an unnecessary evil, for the secret of true progress is the fact that commerce and civilisation always advance together. The Bank of England, which deals in money and credit like every other bank, is exposed to the same influences as the rest of its kind; consequently, when trade is brisk and loanable capital dear, it pays larger dividends than during the depressed portion of a cycle. The following table will illustrate the fact:-- ======================================================================== £14,553,000 STOCK. ---------------------+---------+---------+---------+---------+---------+ \| 1892. \| 1893. \| 1894. \| 1895. \| 1896. \| ---------------------+---------+---------+---------+---------+---------+ \| \| \| \| \| \| Highest \| 344 \| 343 \| 338 \| 336 \| 345 \| \| \| \| \| \| \| Lowest \| 325 \| 325 \| 322 \| 322½ \| 322 \| \| \| \| \| \| \| Dividend % per annum \| \| \| \| \| \| 5th April \| 10 \| 10 \| 8 \| 8 \| 8½ \| \| \| \| \| \| \| Dividend % per annum \| \| \| \| \| \| 5th October \| 9½ \| 9 \| 8½ \| 8½ \| 10 \| \| \| \| \| \| \| ---------------------+---------+---------+---------+---------+---------+ Average Distribution, 9½ per cent. ======================================================================== ====================================================================== £14,553,000 STOCK. ---------------------+---------+---------+---------+---------+-------- \| 1897. \| 1898. \| 1899. \| 1900. \| 1901. ---------------------+---------+---------+---------+---------+-------- \| \| \| \| \| Highest \| 351½ \| 367 \| 36½ \| 349 \| 342 \| \| \| \| \| Lowest \| 326 \| 341 \| 325 \| 326 \| 319¼ \| \| \| \| \| Dividend % per annum \| \| \| \| \| 5th April \| 10 \| 10 \| 10 \| 10 \| 10 \| \| \| \| \| Dividend % per annum \| \| \| \| \| 5th October \| 10 \| 10 \| 10 \| 10 \| 10 \| \| \| \| \| ---------------------+---------+---------+---------+---------+-------- Average Distribution, 9½ per cent. ====================================================================== It is at once evident that when its distributions are compared with those of the large banking companies, the Bank does not excel as a dividend-payer, and the reason, of course, is because it has to distribute its earnings over so large an amount of stock or capital; but, although it pays fluctuating dividends--which are regulated by the average rate capital may earn during any half-year--it is noticeable that, since 1899, despite the fact of dividends being maintained at ten per cent. per annum, the price of Bank stock touched lower figures than any recorded during the decade, when, according to every financial rule, prices ought to have been well maintained. Further, the shares of the joint stock banks did not exhibit this tendency to any marked extent. Why, then, should Bank stock be an exception to the rule? The years 1894 and 1895 were distinguished by cheap money and indifferent trade, therefore we should expect to see the Bank's dividends decrease, and its stock fall in sympathy with diminishing distributions. If we glance at the table we shall see that our deductions were realised. In 1896 trade began to improve. Rising prices lessened the purchasing power of money; consequently the industrial machine required more capital _after_ the rise, because a given sum would then purchase _less_. The result was an increased demand for loanable capital, which at once became dearer; and the Bank of England, together with the other banks in the country, earned more. Again, as one would have expected, dividends and stock moved up together. During 1897 the same movements were witnessed; but in 1899 Bank stock began to fall, although distributions were maintained. This deviation from rule evidently calls for explanation. Compare, for instance, the prices of the shares of the undermentioned banks during the period in question:-- =============================================================== \| \| \| \| \| 1895. \| 1899. \| 1900. \| \| \| \| \| \| \| \| \| ---------------------------------+--------+---------+---------+ \| \| \| \| London and County--_Highest_ \| 95½ \| 109½ \| 107 \| \| \| \| \| " " " _Lowest_ \| 89½ \| 103 \| 101½ \| \| \| \| \| London and Provincial--_Highest_ \| 21¾ \| 22½ \| 22¾ \| \| \| \| \| " " " _Lowest_ \| 19¼ \| 21 \| 21½ \| \| \| \| \| London Joint Stock-_Highest_ \| 34¼ \| 39 \| 37⅞ \| \| \| \| \| " " " _Lowest_ \| 30⅞ \| 33¼ \| 34 \| \| \| \| \| =============================================================== ======================================================== \| \| Dividend % \| 1901. \| per annum \| \| each year \| \| since 1898. ---------------------------------+---------+------------ \| \| London and County--_Highest_ \| 107 \| 22 \| \| " " " _Lowest_ \| 100¼ \| \| \| London and Provincial--_Highest_ \| 23⅜ \| 18 \| \| " " " _Lowest_ \| 20½ \| \| \| London Joint Stock-_Highest_ \| 37¾ \| 12 \| \| " " " _Lowest_ \| 34½ \| 1900 & 1901 \| \| ======================================================== We can see, in the above instances, that where dividends were maintained, prices moved between much the same figures, whilst in every case a marked advance is shown on the quotations of 1895, whereas Bank stock receded further in 1901, when the dividend was ten per cent. per annum, than it did during 1895, when the distribution for the year was only eight-and-a-quarter per cent. It is this anomaly which we have to discuss. The trade of the country from 1896 to the end of 1900 was progressive, and though in 1901 a reaction set in, the large requirements of the Government, and the state of uncertainty created by the war, kept loanable capital dear. The banks, consequently, were enabled to support their huge dividends during 1901, though their being able to declare the same rates for the last half of the present year seems doubtful. But to return to the fall in Bank stock, which, at the moment of writing, is quoted at 326. The public, so little does it understand the position of the Bank of England, still looks upon it as a Government institution; and, as though to give colour to this illusion, we find its stock quoted in the same division as "British Funds &c." By The Trustee Act, 1893, trustees, where they are not prohibited by the trust deed, may invest in Bank of England stock; and, as a result of this enactment, there is an increased demand for its stock, which consequently yields less to a buyer; yet, strictly speaking, Bank stock cannot be classed with the so-called "gilt-edged" securities, because the interest it returns is variable. It is true that the holder does not incur any liability, and in this sense Bank stock is a much more desirable investment than shares in a joint stock bank upon which the member is liable for certain stated sums in the shape of uncalled capital; but the Government does not guarantee the dividends of the Bank. Indeed, it is only interested in the Bank of England in the same manner that a large customer is interested in his banker; and, though, in every probability, so long as the Government banks with the Old Lady, it will assist her whenever cause may arise, it is not pledged so to do. Again, the twentieth century may be productive of great change; and, though it seems improbable that a Government would remove its accounts from the Bank, such an event is by no means impossible, for the only tie between the Government and the Bank of England is that the former is the Bank's oldest client. On the other hand, so long as Government does keep its balances at the Bank of England, it cannot afford to allow the Bank to fail, even were there the risk of it doing so. But holders of Bank stock, like the holders of shares in any other bank, would be paid last should the Bank be wound up, however remote a possibility that may be; and seeing that their capital is not a prior charge upon the assets of the Bank, and that, therefore, £100 of stock is worth £326 only so long as the Bank of England is a going concern, it is difficult to see why Bank stock should be considered a desirable holding for trustees. It seems to me that, valuable though the security undoubtedly is, it does not possess a single one of those characteristics which should distinguish a "trustee" stock, for dividends are fluctuating, and capital is a _last_ charge on the assets of the Bank. In fact, the stock is a kind of guarantee to the customers--and a splendid guarantee too, for it is the Bank's large capital which makes it the safest bank for depositors in the land. But that the holders of a "trustee" stock should, in the event of a company being wound up, get the _last_ look in is surely somewhat odd. However, this is only another illustration of the confidence the public has in the Bank of England, which, people are convinced, will exist as long as the nation. The Bank, because the public imagines that it is connected more closely with the Government than in reality is the case, naturally suffers in credit when its patron does. Consequently during 1899, when the British reverses in South Africa increased the difficulties of the Government and depressed Consols, Bank stock, although dividends were maintained at ten per cent. per annum, fell in sympathy with Government securities, despite the fact that the shares of the large English banking companies were not appreciably affected. Of course this depreciation, which has proved lasting, was not the result of sound reasoning, for so long as the war continued money was sure to be dear, and dear money plainly indicated that the Bank would support its dividend of ten per cent. Further, the large Government borrowings constantly compelled the outside market to borrow from the Bank, which, had it so decided, could have charged exceptionally high rates, and thereby have added considerably to its profit; but, with its usual moderation, it wisely refrained from exacting excessive rates from those who, when Lombard Street was temporarily denuded of surplus capital, were compelled to apply to it for loans. The Bank, during the trying period in question, certainly did not attempt to make extra profit out of the nation's misfortune, as it assuredly might have done had its directors been actuated by a grasping spirit. Is there another bank in the land that would not have profited by the occasion? There may be; but I am disposed to doubt it, and I certainly should not care to attempt to name the institution. Here, then, we find two influences at work at the same time, and the result is distinctly curious. The Bank of England, from the nature of its business, pays increased dividends when trade is good, therefore its stock should advance in value during the prosperous portion of a cycle; but, because of its business relation with the Government, its stock is looked upon by the public as a kind of Government security, and, consequently, when any political event causes Consols to fall, Bank stock recedes in sympathy with them. There is no reason for this movement, and if it proves anything it proves how little Finance is understood by the investing public. Here is a stock which pays fluctuating dividends classed with the so-called "gilt-edged" variety of securities; therefore its movements often seem erratic, because at one time it responds to the law that regulates the price of gilt-edged stocks, and at another to the law which decides the price of industrials. It can be seen from our list that for the decade ended 1901 the Bank of England paid an average dividend of nine-and-a-half per cent. per annum. Based on the said average, a purchaser, if he require a return of three per cent. for his money, will have to buy Bank stock at 316⅔; but 319¼ in 1901 is the lowest price it has touched since 1888, and it seems highly probable that our would-be purchaser at 316⅔ would wait in vain for his stock at those figures. Indeed, the present price, 326, looks cheap for Bank stock. Bought at 325, and based on an average dividend of nine-and-a-half per cent., the stock would return about £2 18s. 6d. per cent. So small a return upon one's money is not calculated to make one anxious to buy, and Consols at 93 are perhaps a greater temptation, though neither investment appeals very strongly, so far as interest is concerned, to the imagination. If purchased during the depressed portion of a cycle, the shares of the large banking companies can be bought at a price which will yield an average dividend of over four-and-a-half per cent. to the investor; but it must be borne in mind that, as a rule, he incurs a certain liability on such shares, whereas Bank stock is free from possible calls, and, consequently, not exposed to the objection which is constantly urged against the majority of bank shares as an investment. Some of my readers, I dare say, will not agree with all my conclusions; and, perhaps, it may be urged that the information herein contained were better withheld from the general public. But the truth is always worth the telling, and if our banking system will not bear investigation then it must be a bad one. Despite obvious defects in construction, it is apparent, however, that our great credit machine, when skilfully managed, can successfully endure considerable strain; and, if gold be dangerously economised, our present system at least gives us that inestimable blessing--Cheap Money. _Sixth Edition._ _Price 1s. net._ BANKS AND THEIR CUSTOMERS. By HENRY WARREN, Author of "The Story of the Bank of England." and "Your Bankers' Position at a Glance." "The book is amusing as well as instructive, and at the price we may reasonably say that no one who has a banking account should omit to read and store it in his library. More especially he who is in the habit of keeping a large balance, as also he who is in the habit of negotiating for an overdraft, should study what is revealed in this book."--_Field._ "Contains a vast mass of useful information intelligently discussed. To educate the public on a technical subject calls for more than ordinary knowledge. It needs what Mr. Warren undoubtedly possesses, and that is a sound practical understanding, and a thorough common-sense way of setting forth his knowledge in simple form. This our Author succeeds admirably in doing."--_Financial News._ "Masterly."--_Drapers' Record._ "Invaluable."--_Birmingham Daily Gazette._ "Cannot be too strongly recommended."--_Scotsman._ "His revelations are startling."--_Morning Post._ "Especially we commend the chapter 'How to check your bankers' charges.'"--_Investors' Review._ _The Author's two most flattering testimonials are_-- "Bank Manager" in _Investors' Review_ says: "The book is not worth the paper upon which it is written." Strangely enough, a Bank Customer writes: "Your little book has saved me £40 a year." EFFINGHAM WILSON, Publisher, Royal Exchange, London. End of Project Gutenberg's The Story of the Bank of England, by Henry Warren	67,252	common-pile/project_gutenberg_filtered	63449	project gutenberg	project_gutenberg-dolma-0012.json.gz:30	https://www.gutenberg.org/ebooks/63449.txt.utf-8
ChScX0APTW04cTbA	English Literature: Victorians and Moderns	204 Brave New World: Chapter 10 Aldous Huxley THE HANDS of all the four thousand electric clocks in all the Bloomsbury Centre’s four thousand rooms marked twenty-seven minutes past two. “This hive of industry,” as the Director was fond of calling it, was in the full buzz of work. Every one was busy, everything in ordered motion. Under the microscopes, their long tails furiously lashing, spermatozoa were burrowing head first into eggs; and, fertilized, the eggs were expanding, dividing, or if bokanovskified, budding and breaking up into whole populations of separate embryos. From the Social Predestination Room the escalators went rumbling down into the basement, and there, in the crimson darkness, stewingly warm on their cushion of peritoneum and gorged with blood-surrogate and hormones, the foetuses grew and grew or, poisoned, languished into a stunted Epsilonhood. With a faint hum and rattle the moving racks crawled imperceptibly through the weeks and the recapitulated aeons to where, in the Decanting Room, the newly-unbottled babes uttered their first yell of horror and amazement. The dynamos purred in the sub-basement, the lifts rushed up and down. On all the eleven floors of Nurseries it was feeding time. From eighteen hundred bottles eighteen hundred carefully labelled infants were simultaneously sucking down their pint of pasteurized external secretion. Above them, in ten successive layers of dormitory, the little boys and girls who were still young enough to need an afternoon sleep were as busy as every one else, though they did not know it, listening unconsciously to hypnopaedic lessons in hygiene and sociability, in class-consciousness and the toddler’s love-life. Above these again were the playrooms where, the weather having turned to rain, nine hundred older children were amusing themselves with bricks and clay modelling, hunt-the-zipper, and erotic play. Buzz, buzz! the hive was humming, busily, joyfully. Blithe was the singing of the young girls over their test-tubes, the Predestinators whistled as they worked, and in the Decanting Room what glorious jokes were cracked above the empty bottles! But the Director’s face, as he entered the Fertilizing Room with Henry Foster, was grave, wooden with severity. “A public example,” he was saying. “In this room, because it contains more high-caste workers than any other in the Centre. I have told him to meet me here at half-past two.” “He does his work very well,” put in Henry, with hypocritical generosity. “I know. But that’s all the more reason for severity. His intellectual eminence carries with it corresponding moral responsibilities. The greater a man’s talents, the greater his power to lead astray. It is better that one should suffer than that many should be corrupted. Consider the matter dispassionately, Mr. Foster, and you will see that no offence is so heinous as unorthodoxy of behaviour. Murder kills only the individual—and, after all, what is an individual?” With a sweeping gesture he indicated the rows of microscopes, the test-tubes, the incubators. “We can make a new one with the greatest ease—as many as we like. Unorthodoxy threatens more than the life of a mere individual; it strikes at Society itself. Yes, at Society itself,” he repeated. “Ah, but here he comes.” Bernard had entered the room and was advancing between the rows of fertilizers towards them. A veneer of jaunty self-confidence thinly concealed his nervousness. The voice in which he said, “Good-morning, Director,” was absurdly too loud; that in which, correcting his mistake, he said, “You asked me to come and speak to you here,” ridiculously soft, a squeak. “Yes, Mr. Marx,” said the Director portentously. “I did ask you to come to me here. You returned from your holiday last night, I understand.” “Yes,” Bernard answered. “Yes-s,” repeated the Director, lingering, a serpent, on the “s.” Then, suddenly raising his voice, “Ladies and gentlemen,” he trumpeted, “ladies and gentlemen.” The singing of the girls over their test-tubes, the preoccupied whistling of the Microscopists, suddenly ceased. There was a profound silence; every one looked round. “Ladies and gentlemen,” the Director repeated once more, “excuse me for thus interrupting your labours. A painful duty constrains me. The security and stability of Society are in danger. Yes, in danger, ladies and gentlemen. This man,” he pointed accusingly at Bernard, “this man who stands before you here, this Alpha-Plus to whom so much has been given, and from whom, in consequence, so much must be expected, this colleague of yours—or should I anticipate and say this ex-colleague?—has grossly betrayed the trust imposed in him. By his heretical views on sport and soma, by the scandalous unorthodoxy of his sex-life, by his refusal to obey the teachings of Our Ford and behave out of office hours, ‘even as a little infant,'” (here the Director made the sign of the T), “he has proved himself an enemy of Society, a subverter, ladies and gentlemen, of all Order and Stability, a conspirator against Civilization itself. For this reason I propose to dismiss him, to dismiss him with ignominy from the post he has held in this Centre; I propose forthwith to apply for his transference to a Sub-Centre of the lowest order and, that his punishment may serve the best interest of Society, as far as possible removed from any important Centre of population. In Iceland he will have small opportunity to lead others astray by his unfordly example.” The Director paused; then, folding his arms, he turned impressively to Bernard. “Marx,” he said, “can you show any reason why I should not now execute the judgment passed upon you?” “Yes, I can,” Bernard answered in a very loud voice. Somewhat taken aback, but still majestically, “Then show it,” said the Director. “Certainly. But it’s in the passage. One moment.” Bernard hurried to the door and threw it open. “Come in,” he commanded, and the reason came in and showed itself. Bloated, sagging, and among those firm youthful bodies, those undistorted faces, a strange and terrifying monster of middle-agedness, Linda advanced into the room, coquettishly smiling her broken and discoloured smile, and rolling as she walked, with what was meant to be a voluptuous undulation, her enormous haunches. Bernard walked beside her. “There he is,” he said, pointing at the Director. “Did you think I didn’t recognize him?” Linda asked indignantly; then, turning to the Director, “Of course I knew you; Tomakin, I should have known you anywhere, among a thousand. But perhaps you’ve forgotten me. Don’t you remember? Don’t you remember, Tomakin? Your Linda.” She stood looking at him, her head on one side, still smiling, but with a smile that became progressively, in face of the Director’s expression of petrified disgust, less and less self-confident, that wavered and finally went out. “Don’t you remember, Tomakin?” she repeated in a voice that trembled. Her eyes were anxious, agonized. The blotched and sagging face twisted grotesquely into the grimace of extreme grief. “Tomakin!” She held out her arms. Some one began to titter. “What’s the meaning,” began the Director, “of this monstrous …” “Tomakin!” She ran forward, her blanket trailing behind her, threw her arms round his neck, hid her face on his chest. A howl of laughter went up irrepressibly. “… this monstrous practical joke,” the Director shouted. Red in the face, he tried to disengage himself from her embrace. Desperately she clung. “But I’m Linda, I’m Linda.'” The laughter drowned her voice. “You made me have a baby,” she screamed above the uproar. There was a sudden and appalling hush; eyes floated uncomfortably, not knowing where to look. The Director went suddenly pale, stopped struggling and stood, his hands on her wrists, staring down at her, horrified. “Yes, a baby—and I was its mother.” She flung the obscenity like a challenge into the outraged silence; then, suddenly breaking away from him, ashamed, ashamed, covered her face with her hands, sobbing. “It wasn’t my fault, Tomakin. Because I always did my drill, didn’t I? Didn’t I? Always … I don’t know how … If you knew how awful, Tomakin … But he was a comfort to me, all the same.” Turning towards the door, “John!” she called. “John!” He came in at once, paused for a moment just inside the door, looked round, then soft on his moccasined feet strode quickly across the room, fell on his knees in front of the Director, and said in a clear voice: “My father!” The word (for “father” was not so much obscene as—with its connotation of something at one remove from the loathsomeness and moral obliquity of child-bearing—merely gross, a scatological rather than a pornographic impropriety); the comically smutty word relieved what had become a quite intolerable tension. Laughter broke out, enormous, almost hysterical, peal after peal, as though it would never stop. My father—and it was the Director! My father! Oh Ford, oh Ford! That was really too good. The whooping and the roaring renewed themselves, faces seemed on the point of disintegration, tears were streaming. Six more test-tubes of spermatozoa were upset. My father! Pale, wild-eyed, the Director glared about him in an agony of bewildered humiliation. My father! The laughter, which had shown signs of dying away, broke out again more loudly than ever. He put his hands over his ears and rushed out of the room.	1,995	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/englishliterature/chapter/brave-new-world-chapter-10/	pressbooks	pressbooks-0000.json.gz:43832	https://ecampusontario.pressbooks.pub/englishliterature/chapter/brave-new-world-chapter-10/
UVJWqlfcxXT0jA3M	Introduction to Sociology	5 Performance Assessment: Sociological Research and the Scientific Method Explain why empirical research is used to study the social world. Compare and contrast “common sense” assumptions with scientifically tested knowledge about the social world. Demonstrate the ways in which empirical research is used to study the social world by constructing a mock research proposal or plan. Select and justify the use of specific methodologies based on your topic or question. Construct appropriate (i.e., empirical) sociological questions as if you were researching a research proposal. Identify and describe different types of research and research methods available for use, discussing the benefits and limitations of each. Explain why you would choose the method you end up with. Evaluate your proposed research in terms of validity, reliability, and ethical considerations. Your response should exceed 500 words and should provide at least one example. Basic Requirements (assignment criteria): - Assignment has been proofread and does not contain any major spelling or grammatical errors. - A minimum of 500 words in length, double spaced, 1 inch margins. - Resources are cited in APA format in a reference list and using parenthetical citations (if you need help with this, review course resources). - Relevant terms and concepts are used and defined. Criteria Ratings Pts \| 10.0 pts \| 9.0 pts \| 8.0 pts \| 0.0 pts \| \| 10.0 pts \| 9.0 pts \| 8.0 pts \| 0.0 pts \| \| 10.0 pts \| 9.0 pts \| 8.0 pts \| 0.0 pts \|	321	common-pile/pressbooks_filtered	https://library.achievingthedream.org/mvccintrotosociology/chapter/sociological-research-and-the-scientific-method/	pressbooks	pressbooks-0000.json.gz:35555	https://library.achievingthedream.org/mvccintrotosociology/chapter/sociological-research-and-the-scientific-method/
i0FS_zHNKQKxs7s6	Meteorology; or, Weather Explained	Produced by The Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive.) SHILLING SCIENTIFIC SERIES [Illustration: DR. AITKEN'S DUST-COUNTER. R is the test-receiver; P the air-pump; M the measuring apparatus; L the illuminating arrangements; G the Gasometer; A the pipe through which the tested air is drawn.] METEOROLOGY; OR, WEATHER EXPLAINED. BY J. G. M'PHERSON, Ph.D., F.R.S.E., GRADUATE WITH FIRST-CLASS HONOURS, AND FOR NINE YEARS EXTENSION LECTURER ON METEOROLOGY AND MATHEMATICAL EXAMINER IN THE UNIVERSITY OF ST. ANDREWS; AUTHOR OF "TALES OF SCIENCE," ETC. LONDON: T. C. & E. C. JACK, 34 HENRIETTA STREET, W.C. AND EDINBURGH. 1905. THE SHILLING SCIENTIFIC SERIES _The following Vols. are now ready or in the Press_:-- BALLOONS, AIRSHIPS, AND FLYING MACHINES. By GERTRUDE BACON. MOTORS AND MOTORING. By Professor HARRY SPOONER. RADIUM. By Dr. HAMPSON. TELEGRAPHY WITH AND WITHOUT WIRES. By W. J. WHITE. ELECTRIC LIGHTING. By S. F. WALKER, R.N., M.I.E.E. LOCAL GOVERNMENT. By PERCY ASHLEY, M.A. _Others in Preparation_ Printed by BALLANTYNE, HANSON & CO. At the Ballantyne Press CONTENTS CHAP. PAGE I. INTRODUCTION 9 II. THE FORMATION OF DEW 13 III. TRUE AND FALSE DEW 17 IV. HOAR-FROST 20 V. FOG 23 VI. THE NUMBERING OF THE DUST 26 VII. DUST AND ATMOSPHERIC PHENOMENA 29 VIII. A FOG-COUNTER 31 IX. FORMATION OF CLOUDS 34 X. DECAY OF CLOUDS 37 XI. IT ALWAYS RAINS 40 XII. HAZE 43 XIII. HAZING EFFECTS OF ATMOSPHERIC DUST 47 XIV. THUNDER CLEARS THE AIR 49 XV. DISEASE GERMS IN THE AIR 53 XVI. A CHANGE OF AIR 55 XVII. THE OLD MOON IN THE NEW MOON'S ARMS 58 XVIII. AN AUTUMN AFTERGLOW 62 XIX. A WINTER FOREGLOW 65 XX. THE RAINBOW 68 XXI. THE AURORA BOREALIS 71 XXII. THE BLUE SKY 74 XXIII. A SANITARY DETECTIVE 78 XXIV. FOG AND SMOKE 80 XXV. ELECTRICAL DEPOSITION OF SMOKE 83 XXVI. RADIATION FROM SNOW 86 XXVII. MOUNTAIN GIANTS 88 XXVIII. THE WIND 92 XXIX. CYCLONES AND ANTI-CYCLONES 95 XXX. RAIN PHENOMENA 98 XXXI. THE METEOROLOGY OF BEN NEVIS 102 XXXII. THE WEATHER AND INFLUENZA 107 XXXIII. CLIMATE 110 XXXIV. THE "CHALLENGER" WEATHER REPORTS 114 XXXV. WEATHER-FORECASTING 116 INDEX 124 PREFATORY NOTE I am very much indebted to Dr. John Aitken, F.R.S., for his great kindness in carefully revising the proof sheets, and giving me most valuable suggestions. This is a sufficient guarantee that accuracy has not been sacrificed to popular explanation. J. G. M'P. RUTHVEN MANSE, _June 10, 1905_. METEOROLOGY CHAPTER I INTRODUCTION Though by familiarity made commonplace, the "weather" is one of the most important topics of conversation, and has constant bearings upon the work and prospects of business-men and men of pleasure. The state of the weather is the password when people meet on the country road: we could not do without the humble talisman. "A fine day" comes spontaneously to the lips, whatever be the state of the atmosphere, unless it is peculiarly and strikingly repulsive; then "A bitter day" would take the place of the expression. Yet I have heard "_Terrible_ guid wither" as often as "_Terrible_ bad day" among country people. Scarcely a friendly letter is penned without a reference to the weather, as to what has been, is, or may be. It is a new stimulus to a lagging conversation at any dinner-table. All are so dependent on the weather, especially those getting up in years or of delicate health. I remember, when at Strathpeffer, the great health-resort in the North of Scotland, in 1885, an anxious invalid at "The Pump" asking a weather-beaten, rheumatic old gamekeeper what sort of a day it was to be, considering that it had been wet for some time. The keeper crippled to the barometer outside the doorway, and returned with the matter-of-fact answer: "She's faurer doon ta tay nur she wass up yestreen." The barometer had evidently fallen during the night. "And what are we to expect?" sadly inquired the invalid. "It'll pe aither ferry wat, or mohr rain"--a poor consolation! Most men who are bent on business or pleasure, and all dwellers in the country who have the instruments, make a first call at the barometer in the lobby, or the aneroid in the breakfast-parlour, to "see what she says." A good rise of the black needle (that is, to the right) above the yellow needle is a source of rejoicing, as it will likely be clear, dry, and hard weather. A slight fall (that is, to the left) causes anxiety as to coming rain, and a big depression forebodes much rain or a violent storm of wind. In either case of "fall," the shutters come over the eyes of the observer. Next, even before breakfast, a move is made to the self-registering thermometer (set the night before) on a stone, a couple of feet above the grass. A good reading, above the freezing-point in winter and much above it in summer, indicates the absence of killing rimes, that are generally followed by rain. A very low register accounts for the feeling of cold during the night, though the fires were not out; and predicts precarious weather. Ordinarily careful observers--as I, who have been in one place for more than thirty years--can, with the morning indications of these two instruments, come pretty sure of their prognostics of the day's weather. Of course, the morning newspaper is carefully scanned as to the weather-forecasts from the London Meteorological Office--direction of wind; warm, mild, or cold; rain or fair, and so on--and in general these indications are wonderfully accurate for twenty-four hours; though the "three days'" prognostics seem to stretch a point. We are hardly up to that yet. The lower animals are very sensitive as to the state of approaching extremes of weather. "Thae sea beass," referring to sea-gulls over the inland leas during ploughing, are ordinary indicators of stormy weather. Wind is sure to follow violent wheelings of crows. "Beware of rain" when the sheep are restive, rubbing themselves on tree stumps. But all are familiar with Jenner's prognostics of rain. Science has come to the aid of ordinary weather-lore during the last twenty years, by leaps and bounds. Time-honoured notions and revered fictions, around which the hallowed associations of our early training fondly and firmly cling, must now yield to the exact handling of modern science; and with reluctance we have to part with them. Yet there is in all a fascination to account for certain ordinary phenomena. "The man in the street," as well as the strong reading man, wishes to know the "why" and the "how" of weather-forecasting. They are anxious to have weather-phenomena explained in a plain, interesting, but accurate way. The freshness of the marvellous results has an irresistible charm for the open mind, keen for useful information. The discoveries often seem so simple that one wonders why they were not made before. Until about twenty years ago, Meteorology was comparatively far back as a science; and in one important branch of it, no one has done more to put weather-lore on a scientific basis than Dr. John Aitken, F.R.S., who has very kindly given me his full permission to popularise what I like of his numerous and very valuable scientific papers in the _Transactions of the Royal Society of Edinburgh_. This I have done my best to carry out in the following pages. "The way of putting it" is my only claim. Many scientific men are decoyed on in the search for truth with a spell unknown to others: the anticipation of the results sometimes amounts to a passion. Many wrong tracks do they take, yet they start afresh, just as the detective has to take several courses before he hits upon the correct scent. When they succeed, they experience a pleasure which is indescribable; to them fame is more than a mere "fancied life in others' breath." Dr. Aitken's continued experiments, often of rare ingenuity and brilliancy, show that no truth is altogether barren; and even that which looks at first sight the very simplest and most trivial may turn out fruitful in precious results. Small things must not be overlooked, for great discoveries are sometimes at a man's very door. Dr. Aitken has shown us this in many of his discoveries which have revolutionised a branch of meteorology. Prudence, patience, observing power, and perseverance in scientific research will do much to bring about unexpected results, and not more so in any science than in accounting for weather-lore on a rational basis, which it is in the power of all my readers to further. "The old order changeth, giving place to new." With kaleidoscopic variety Nature's face changes to the touch of the anxious and reverent observer. And some of these curious weather-views will be disclosed in these pages, so as, in a brief but readable way, to explain the weather, and lay a safe basis for probable forecastings, which will be of great benefit to the man of business as well as the man of pleasure. "Felix, qui potuit rerum cognoscere causas." --VIRGIL. CHAPTER II THE FORMATION OF DEW The writer of the Book of Job gravely asked the important question, "Who hath begotten the drops of dew?" We repeat the question in another form, "Whence comes the real dew? Does it fall from the heavens above, or does it rise from the earth beneath?" Until about the beginning of the seventeenth century, scientific men held the opinion of ordinary observers that dew fell from the atmosphere. But there was then a reaction from this theory, for Nardius defined it as an exhalation from the earth. Of course, it was well known that dew was formed by the precipitation of the vapour of the air upon a colder body. You can see that any day for yourself by bringing a glass of very cold water into a warm room; the outer surface of the glass is dimmed at once by the moisture from the air. M. Picket was puzzled when he saw that a thermometer, suspended five feet above the ground, marked a lower temperature on clear nights than one suspended at the height of seventy-five feet; because it was always supposed that the cold of evening descended from above. Again he was puzzled when he observed that a buried thermometer read higher than one on the surface of the ground. Until recently the greatest authority on dew was Dr. Wells, who carefully converged all the rays of scientific light upon the subject. He came to the conclusion that dew was condensed out of the air. But the discovery of the true theory was left to Dr. John Aitken, F.R.S., a distinguished observer and a practical physicist, of whom Scotland has reason to be proud. About twenty years ago he made the discovery, and it is now accepted by all scientific men on the Continent as well as in Great Britain. What first caused him to doubt Dr. Wells' theory, so universally accepted, that dew is formed of vapour existing at the time in the air, and to suppose that dew is mostly formed of vapour rising from the ground, was the result of some observations made in summer on the temperature of the soil at a small depth under the surface, and of the air over it, after sunset and at night. He was struck with the unvarying fact that the ground, a little below the surface, was warmer than the air over it. By placing a thermometer among stems below the surface, he found that it registered 18° Fahr. higher than one on the surface. So long, then, as the surface of the ground is above the dew-point (_i.e._ the temperature when dew begins to be formed), vapour must rise from the ground; this moist air will mingle with the air which it enters, and its moisture will be condensed and form dew, whenever it comes in contact with a surface cooled below the dew-point. You can verify this by simple experiments. Take a thin, shallow, metal tray, painted black, and place it over the ground after sunset. On dewy nights the _inside_ of the tray is dewed, and the grass inside is wetter than that outside. On some nights there is no dew outside the tray, and on all nights the deposit on the inner is heavier than that on the outside. If wool is used in the experiments, we are reminded of one of the forms of the dewing of Gideon's fleece--the fleece was bedewed when all outside was dry. You therefore naturally and rightly come to the conclusion that far more vapour rises out of the ground during the night than condenses as dew on the grass, and that this vapour from the ground is trapped by the tray. Much of the rising vapour is generally carried away by the passing wind, however gentle; hence we have it condensed as dew on the roofs of houses, and other places, where you would think that it had fallen from above. The vapour rising under the tray is not diluted by the mixture with the drier air which is occasioned by the passing wind; therefore, though only cooled to the same extent as the air outside, it yields a heavier deposit of dew. If you place the tray on bare ground, you will find on a dewy night that the inside of the tray is quite wet. On a dewy night you will observe that the under part of the gravel of the road is dripping wet when the top is dry. You will find, too, that around pieces of iron and old implements in the field, there is a very marked increase of grass, owing to the deposit of moisture on these articles--moisture which has been condensed by the cold metal from the vapour-charged air, which has risen from the ground on dewy nights. But all doubt upon this important matter is removed by a most successful experiment with a fine balance, which weighs to a quarter of a grain. If vapour rises from the ground for any length of time during dewy nights, the soil which gives off the vapour must lose weight. To test this, cut from the lawn a piece of turf six inches square and a quarter of an inch thick. Place this in a shallow pan, and carefully note the weight of both turf and pan with the sensitive balance. To prevent loss by evaporation, the weighing should be done in an open shed. Then place the pan and turf at sunset in the open cut. Five hours afterwards remove and weigh them, and it will be found that the turf has lost a part of its weight. The vapour which rose from the ground during the formation of the dew accounts for the difference of weight. This weighing-test will also succeed on bare ground. When dealing with hoar-frost, which is just frozen dew, we shall find visible evidence of the rising of dew from the ground. You know the beautiful song, "Annie Laurie," which begins with-- "Maxwelton's braes are bonnie, Where early fa's the dew"-- well, you can no longer say that the dew "falls," for it rises from the ground. The song, however, will be sung as sweetly as ever; for the spirit of true poetry defies the cold letter of science. TRUE AND FALSE DEW Ever since men could observe and think, they have admired the diamond globules sparkling in the rising sun. These "dew-drops" were considered to be shed from the bosom of the morn into the blooming flowers and rich grass-leaves. Ballantine's beautiful song of Providential care tells us that "Ilka blade o' grass keps it's ain drap o' dew." But, alas! we have to bid "good-bye" to the appellation "dew-drop." What was popularly and poetically called dew _is not dew at all_. Then what is it? On what we have been accustomed to call a "dewy" night, after the brilliant summer sun has set, and the stars begin to peep out of the almost cloudless sky, let us take a look at the produce of our vegetable garden. On the broccoli are found glistening drops; but on the peas, growing next them, we find nothing. A closer examination shows us that the moisture on the plants is not arranged as would be expected from the ordinary laws of radiation and condensation. There is no generally filmy appearance over the leaves; the moisture is collected in little drops placed at short distances apart, along the edges of the leaves all round. Now place a lighted lantern below one of the blades of the broccoli, and a revelation will be made. The brilliant diamond-drops that fringe the edge of the blade are all placed at the points where the nearly colourless veins of the blade come to the outer edge. The drops are not dew at all, but the exudation of the healthy plant, which has been conveyed up these veins by strong root-pressure. The fact is that the root acts as a kind of force-pump, and keeps up a constant pressure inside the tissues of the plant. One of the simplest experiments suggested by Dr. Aitken is to lift a single grass-plant, with a clod of moist earth attached to it, and place it on a plate with an inverted tumbler over it. In about an hour, drops will begin to exude, and the tip of nearly every blade will be found to be studded with a diamond-like drop. Next substitute water-pressure. Remove a blade of broccoli and connect it by means of an india-rubber tube with a head of water of about forty inches. Place a glass receiver over it, so as to check evaporation, and leave it for an hour. The plant will be found to have excreted water freely, some parts of the leaves being quite wet, while drops are collected at the places where they appeared at night. If the water pressed into the leaf is coloured with aniline blue, the drops when they first appear are colourless; but before they grow to any size, the blue appears, showing that little water was held in the veins. The whole leaf soon gets coloured of a fine deep blue-green, like that seen when vegetation is rank; this shows that the injected liquid has penetrated through the whole leaf. Again, the surfaces of the leaves of these drop-exuding plants never seem to be wetted by the water. It is because of the rejection of water by the leaf-surface that the exuded moisture from the veins remains as a drop. These observations and experiments establish the fact that the drops which first make their appearance on grass on dewy nights are not dew-drops at all, but the exuded watery juices of the plants. If now we look at dead leaves we shall find a difference of formation of the moisture on a dewy night: the moisture is spread equally over, where equally exposed. The moisture exuded by the healthy grass is always found at a _point_ situated near the tip of the blade, forming a drop of some size; but the true dew collects later on _evenly_ all over the blade. The false dew forms a large glistening diamond-drop, whereas the true dew coats the blade with a fine pearly lustre. Brilliant globules are produced by the vital action of the plant, especially beautiful when the deep-red setting sun makes them glisten, all a-tremble, with gold light; while an infinite number of minute but shining opal-like particles of moisture bedecks the blade-surfaces, in the form of the gentle dew-- "Like that which kept the heart of Eden green Before the useful trouble of the rain." CHAPTER IV HOAR-FROST All in this country are familiar with the beauty of hoar-frost. The children are delighted with the funny figures on the glass of the bedroom window on a cold winter morning. Frost is a wonderful artist; during the night he has been dipping his brush into something like diluted schist, and laying it gracefully on the smooth panes. And, as you walk over the meadows, you observe the thin white films of ice on the green pasture; and the clear, slender blades seem like crystal spears, or the "lashes of light that trim the stars." You all know what hoar-frost is, though most in the country give it the expressive name of "rime." But you are not all aware of how it is formed. Hoar-frost is just frozen dew. In a learned paper, written in 1784, Professor Wilson of Glasgow made this significant remark: "This is a subject which, besides its entire novelty, seems, upon other accounts, to have a claim to some attention." He observed, in that exceptionally cold winter, that, when sheets of paper and plates of metal were laid out, all began to attract hoar-frost as soon as they had time to cool down to the temperature of the air. He was struck with the fact that, while the thermometer indicated 36 degrees of frost a few feet above the ground and 44 degrees of frost at the surface of the snow, there were only 8 degrees of frost at a point 3 inches below the surface of the snow. If he had only thought of placing the thermometer on the grass, under the snow, he would have found it to register the freezing-point only. And had he inserted the instrument below the ground, he would have found it registering a still higher temperature. That fact would have suggested to him the formation of hoar-frost; that the water-vapour from the warm soil was trapped by a cold stratum of air and frozen when in the form of dew. One of the most interesting experiments, without apparatus, which you can make is in connection with the formation of hoar-frost, when there is no snow on the ground, in very cold weather. If it has been a bright, clear, sunny day in January, the effect can be better observed. Look over the garden, grass, and walks on the morning after the intense cold of the night; big plane-tree leaves may be found scattered over the place. You see little or no hoar-frost on the _upper_ surface of the leaves. But turn up the surface next the earth, or the road, or the grass, and what do you see? You have only to handle the leaf in this way to be brightly astonished. A thick white coating of hoar-frost, as thick as a layer of snow, is on the _under_ surface. If a number of leaves have been overlapping each other, there will be no coating of hoar-frost under the top leaves; but when you reach the lowest layer, next the bare ground, you will find the hoar-frost on the under surface of the leaves. Now that is positive proof that the hoar-frost has not fallen from the air, but has risen from the earth. The sun's heat on the previous day warmed the earth. This heat the earth retained till evening. As the air chilled, the water-vapour from the warmer earth rose from its surface, and was arrested by the cold surface of the leaves. So cold was that surface that it froze the water-vapour when rising from the earth, and formed hoar-frost in very large quantities. When this happens later on in the season, one may be almost sure of having rain in the forenoon. As hoar-frost is just frozen dew, I can even more surely convince you of the formation of hoar-frost as rising from the ground by observations made by me at my manse in Strathmore, in June 1892. I mention this particularly because then was the most favourable testing-time that has _ever_ occurred during meteorological observations. June 9th was the warmest June day (with one exception) for twenty years. The thermometer reached 83° Fahr. in the shade. Next day was the coldest June day (with one exception) for twenty years, when the thermometer was as low as 51° in the shade. But during the night my thermometer on the grass registered 32°--the freezing point. On the evening of the sultry day I examined the soil at 10 o'clock. It was damp, and the grass round it was filmy moist. The leaves of the trees were crackling dry, and all above was void of moisture. The air became gradually chilly; and as gradually the moisture rose in height on the shrubs and lower branches of small trees. The moon shone bright, and the stars showed their clear, chilly eyes. The soil soon became quite wet, the low grass was dripping with moisture, and the longer grass was becoming dewed. This gave the best natural evidence of the rising of the dew that I ever witnessed. But everything was favourable for the observation--the cold air incumbent on the rising, warm, moist vapour from the soil fixing the dew-point, when the projecting blades seized the moisture greedily and formed dew. Had the temperature been a little below the freezing-point, hoar-frost would have been beautifully formed. CHAPTER V FOG To many nothing is more troublesome than a dense fog in a large town. It paralyses traffic, it is dangerous to pedestrians, it encourages theft, it chokes the asthmatic, and chills the weak-lunged. In the country it is disagreeable enough; but never so intensely raw and dense as in the city. On the sea, too, the fog is disagreeable and fraught with danger. The fog-horn is heard, in its deep, sombre note, from the lighthouse tower, when the strong artificial light is almost useless. But a peculiar sense of stagnation possesses the dweller of the large town, when enveloped in a dense fog. Sometimes during the day, through a thinner portion, the sun will be dimly seen in copper hue, like the moon under an eclipse. The smoke-impregnated mass assumes a peculiar "pea-soup" colour. Now, what is this fog? How is it formed? It has been ascertained that fogs are dependent upon _dust_ for their formation. Without dust there could be no fogs, there would be only dew on the grass and road. Instead of the dust-impregnated air that irritates the housekeeper, there would be the constant dripping of moisture on the walls, which would annoy her more. Ocular demonstration can testify to this. If two closed glass receivers be placed beside each other, the one containing ordinary air, and the other filtered air (_i.e._ air deprived of its dust by being driven through cotton wool), and if jets of steam be successively introduced into these, a strange effect is noticed. In the vessel containing common air the steam will be seen rising in a dense cloud; then a beautiful white foggy cloud will be formed, so dense that it cannot be seen through. But in the vessel containing the filtered air, the steam is not seen at all; there is not the slightest appearance of cloudiness. In the one case, where there was the ordinary atmospheric dust, fog at once appeared; in the other case, where there was no dust in suspension, the air remained clear and destitute of fog. Invisible dust, then, is necessary in the air for the formation of fogs. The reason of this is that a free-surface must exist for the condensation of the vapour-particles. The fine particles of dust in the air act as free-surfaces, on which the fog is formed. Where there is abundance of dust in the air and little water-vapour present, there is an over-proportion of dust-particles; and the fog-particles are, in consequence, closely packed, but light in form and small in size, and take the lighter appearance of fog. Accordingly, if the dust is increased in the air, there is a proportionate increase of fog. Every fog-particle, then, has embosomed in it an invisible dust-particle. But whence comes the dust? From many sources. It is organic and inorganic. So very fine is the inorganic dust in the atmosphere that, if the two-thousandth part of a grain of fine iron be heated, and the dust be driven off and carried into a glass receiver of filtered air, the introduction of a jet of steam into that receiver would at once occasion an appreciable cloudiness. This is why fogs are so prevalent in large towns. Next the minute brine-particles, driven into the air as fog forms above the ocean surface, are the burnt sulphur-particles emanating from the chimneys in towns. The brilliant flame, as well as the smoky flame, is a fog-producer. If gas is burnt in filtered air, intense fog is produced when water-vapour is introduced. Products of combustion from a clear fire and from a smoky one produce equal fogging. The fogs that densely fill our large towns are generally less bearable than those that veil the hills and overhang the rivers. It is the sulphur, however, from the consumed coals, which is the active producer of the fogs of a large town. The burnt sulphur condenses in the air to very fine particles, and the quantity of burnt sulphur is enormous. No less than seven and a half millions of tons of coals are consumed in London. Now, the average amount of sulphur in English coal is one and a quarter per cent. That would give no less than 93,750 tons of sulphur burned every year in London fires. Now, if we reckon that on an average twice the quantity of coals is consumed there on a winter day that is consumed on a summer day, no less than 347 tons of the products of combustion (in extremely fine particles) are driven into the superincumbent air of London every winter day. This is an enormous quantity, quite sufficient to account for the density of the fogs in that city. CHAPTER VI THE NUMBERING OF THE DUST If the shutters be all but closed in a room, when the sun is shining in, myriads of floating particles can be seen glistening in the stream of light. Their number seems inexhaustible. According to Milton, the follies of life are-- "Thick and numberless, As the gay motes that people the sunbeams." Can these, then, be counted? Yes, Dr. Aitken has numbered the dust of the air. I shall never forget my rapt astonishment the day I first numbered the dust in the lecture-room of the Royal Society of Edinburgh, with his instrument and under his direction. This wonderfully ingenious instrument was devised on this principle, that every fog-particle has entombed in it an invisible dust-particle. A definite small quantity of common air is diluted with a fixed large quantity of dustless air (_i.e._ air that has been filtered through cotton-wool). The mixture is allowed to be saturated with water-vapour. Then the few particles of dust seize the moisture, become visible in fine drops, fall on a divided plate, and are there counted by means of a magnifying glass. That is the secret! I shall now give you a general idea of the apparatus. Into a common glass flask of carafe shape, and flat-bottomed, of 30 cubic inches capacity, are passed two small tubes, at the end of one of which is attached a small square silver table, 1 inch in length. A little water having been inserted, the flask is inverted, and the table is placed exactly 1 inch from the inverted bottom, so that the contents of air right above the table are 1 cubic inch. This observing table is divided into 100 equal squares, and is highly polished, with the burnishing all in one direction, so that during the observations it appears dark, when the fine mist-particles glisten opal-like with the reflected light in order that they may be more easily counted. The tube to which the silver table is attached is connected with two stop-cocks, one of which can admit a small measured portion of the air to be examined. The other tube in the flask is connected with an air-pump of 10 cubic inches capacity. Over the flask is placed a covering, coloured black in the inside. In the top of this cover is inserted a powerful magnifying glass, through which the particles on the silver table can be easily counted. A little to the side of this magnifier is an opening in the cover, through which light is concentrated on the table. To perform the experiment, the air in the flask is exhausted by the air-pump. The flask is then filled with filtered air. One-tenth of a cubic inch of the air to be examined is then introduced into the flask, and mixed with the 30 cubic inches of dustless air. After one stroke of the air-pump, this mixed air is made to occupy an additional space of 10 cubic inches; and this rarefying of the air so chills it that condensation of the water-vapour takes place on the dust-particles. The observer, looking through the magnifying-glass upon the silver table, sees the mist-particles fall like an opal shower on the table. He counts the number on a single square in two or three places, striking an average in his mind. Suppose the average number upon a single square were five, then on the whole table there would be 500; and these 500 particles of dust are those which floated invisibly in the cubic inch of mixed air right above the table. But, as there are 40 cubic inches of mixed air in the flask and barrel, the number of dust-particles in the whole is 20,000. That is, there are 20,000 dust-particles in the same quantity of common air (one-tenth of a cubic inch) which was introduced for examination. In other words, a cubic inch of the air contained 200,000 dust-particles--nearly a quarter of a million. The day I used the instrument we counted 4,000,000 of dust-particles in a cubic inch of the air outside of the room, due to the quantity of smoke from the passing trains. Dr. Aitken has counted in 1 cubic inch of air immediately above a Bunsen flame the fabulous number of 489,000,000 of dust-particles. A small instrument has been constructed which can bring about results sufficiently accurate for ordinary purposes. It is so constructed that, when the different parts are unscrewed, they fit into a case 4-1/2 inches by 2-1/2 by 1-1/4 deep--about the size of an ordinary cigar-case. After knowing this, we are apt to wonder why our lungs do not get clogged up with the enormous number of dust-particles. In ordinary breathing, 30 cubic inches of air pass in and out at every breath, and adults breathe about fifteen times every minute. But the warm lung-surface repels the colder dust-particles, and the continuous evaporation of moisture from the surface of the air-tubes prevents the dust from alighting or clinging to the surface at all. CHAPTER VII DUST AND ATMOSPHERIC PHENOMENA Dr. Aitken has devoted a vast amount of attention to the enumeration of dust-particles in the air, on the Continent as well as in Scotland, to determine the effects of their variation in number. On his first visit to Hyères, in 1890, he counted with the instrument 12,000 dust-particles in a cubic inch of the air: whereas in the following year he counted 250,000. He observed, however, that where there was least dust, the air was very clear; whereas with the maximum of dust, there was a very thick haze. At Mentone, the corresponding number was 13,000, when the wind was blowing from the mountains; but increased to 430,000, when the wind was blowing from the populous town. On his first visit to the Rigi Kulm, in Switzerland, the air was remarkably clear and brilliant, and the corresponding number never exceeded 33,000; but, on his second visit, he counted no less than 166,000. This was accounted for by a thick haze, which rendered the lower Alps scarcely visible. The upper limit of the haze was well defined; and though the sky was cloudless, the sun looked like a harvest moon, and required no eagle's eye to keep fixed on it. Next day there was a violent thunder-storm. At 6 P.M. the storm commenced, and 60,000 dust-particles to the cubic inch of air were registered; but in the middle of the storm he counted only 13,000. There was a heavy fall of hail at this time, and he accounts for the diminution of dust-particles by the down-rush of purer upper air, which displaced the contaminated lower air. At the Lake of Lucerne there was an exceptional diminution of the number in the course of an hour, viz. from 171,000 to 28,000 in a cubic inch. On looking about, he found that the direction of the wind had changed, bringing down the purer upper air to the place of observation. The bending downwards of the trees by the strong wind showed that it was coming from the upper air. Returning to Scotland, he continued his observations at Ben Nevis and at Kingairloch, opposite Appin, Mr. Rankin using the instrument at the top of the mountain. These observations showed in general that on the mountain southerly, south-easterly, and easterly winds were more impregnated with dust-particles, sometimes containing 133,000 per cubic inch. Northerly winds brought pure air. The observations at sea-level showed a certain parallelism to those on the summit of the mountain. With a north-westerly wind the dust-particles reached the low number of 300 per cubic inch, the lowest recorded at any low-level station. The general deductions which he made from his numerous observations during these two years are that (1) air coming from inhabited districts is always impure; (2) dust is carried by the wind to enormous distances; (3) dust rises to the tops of mountains during the day; (4) with much dust there is much haze; (5) high humidity causes great thickness of the atmosphere, if accompanied by a great amount of dust, whereas there is no evidence that humidity alone has any effect in producing thickness; (6) and there is generally a high amount of dust with high temperature, and a low amount of dust with low temperature. CHAPTER VIII A FOG-COUNTER Next to the enumeration of the dust-particles in the atmosphere is the marvellous accuracy of counting the number of particles in a fog. The same ingenious inventor has constructed a fog-counter for the purpose; and the number of fog-particles in a cubic inch can be ascertained. This instrument consists of a glass micrometer divided into squares of a known size, and a strong microscope for observing the drops on the stage. The space between the micrometer and the microscope is open, so that the air passes freely over the stage; and the drops that fall on its surface are easily seen. These drops are very small; many of them when spread on the glass are no more than the five-hundredth of an inch in diameter. In observing these drops, the attention requires to be confined to a limited area of the stage, as many of the drops rapidly evaporate, some almost as soon as they touch the glass, whilst the large ones remain a few seconds. In one set of Dr. Aitken's observations, in February 1891, the fog was so thick that objects beyond a hundred yards were quite invisible. The number of drops falling per second varied greatly from time to time. The greatest number was 323 drops per square inch in one second. The high number never lasted for long, and in the intervals the number fell as low as 32, or to one-tenth. If we knew the size of these drops, we might be able to calculate the velocity of their fall, and from that obtain the number in a cubic inch. An ingenious addition is put to the instrument in order to ascertain this directly. It is constructed so as to ascertain the number of particles that fall from a known height. Under a low-power microscope, and concentric with it, is mounted a tube 2 inches long and 1-1/2 inch in diameter, with a bottom and a cover, which are fixed to an axis parallel with the axis of the tube, so that, by turning a handle, these can be slid sideways, closing or opening the tube at both ends when required. In the top is a small opening, corresponding to the lens of the microscope, and in the centre of the bottom is placed the observing-stage illumined by a spot-mirror. The handle is turned, and the ends are open to admit the foggy air. The handle is quickly reversed, and the ends are closed, enabling the observer to count on the stage all the fog-particles in the two inches of air over it. The number of dust-particles in the air which become centres of condensation depends on the rate at which the condensation is taking place. The most recent observations show that quick condensation causes a large number of particles to become active, whereas slow condensation causes a small number. After the condensation has ceased, a process of differentiation takes place, the larger particles robbing the smaller ones of their moisture, owing to the vapour-pressure at the surface of the drops of large curvature being less than at the surface of drops of smaller curvature. By this process the particles in a cloud are reduced in number; the remaining ones, becoming larger, fall quicker. The cloud thus becomes thinner for a time. A strong wind, suddenly arising, will cause the cloud-particles to be rapidly formed: these will be very numerous, but very small--so small that they are just visible with great care under a strong magnifying lens used in the instrument. But in slowly formed clouds the particles are larger, and therefore more easily visible to the naked eye. Though the particles in a fog are slightly finer, the number is about the same as in a cloud--that is, generally. As clouds vary in density, the number of particles varies. Sometimes in a cloud one cannot see farther than 30 yards; whereas in a few minutes it clears up a little, so that we can see 100 yards. Of course, the denser the cloud the greater the number of water-particles falling on the calculating-stage of the instrument. Very heavy falls of cloud-particles seldom last more than a few seconds, the average being about 325 on the square inch per second, the maximum reaching to 1290. This is about four times the number counted in a fog. Yet the particles are so very small that they evaporate instantly when they reach a slight increase of temperature. CHAPTER IX FORMATION OF CLOUDS In our ordinary atmosphere there can be no clouds without dust. A dust-particle is the nucleus that at a certain humidity becomes the centre of condensation of the water-vapour so as to form a cloud-particle; and a collection of these forms a cloud. This condensation of vapour round a number of dust-particles in visible form gives rise to a vast variety of cloud-shapes. There are two distinct ways in which the formation of clouds generally takes place. Either a layer of air is cooled in a body below the dew-point; or a mass of warm and moist air rises into a mass which is cold and dry. The first forms a cloud, called, from being a layer, _stratus_; the second forms a cloud, called, from its heap appearance, _cumulus_. The first is widely extended and horizontal, averaging 1800 feet in height; the second is convex or conical, like the head of a sheaf, increasing upward from a level base, averaging from 4500 feet to 6000 feet in height. There are endless combinations of these two; but at the height of 27,000 feet, where the cloud-particles are frozen, the structure of the cloud is finer, like "mares' tails," receiving the name _cirrus_. When the cirrus and cumulus are combined, in well-defined roundish masses, what is familiarly described as a "mackerel sky" is beautifully presented. The dark mass of cloud, called _nimbus_, is the threatening rain-cloud, about 4500 feet in height. At the International Meteorological Conference at Munich, in 1892, twelve varieties of clouds were classified, but those named above are the principal. In a beautiful sunset one can sometimes notice two or three distances of clouds, the sun shedding its gold light on the full front of one set, and only fringing with vivid light the nearer range. Although no man has wrought so hard as Dr. Aitken to establish the principle that clouds are mainly due to the existence of dust-particles which attract moisture on certain conditions, yet even twenty years ago he said that it was probable that sunshine might cause the formation of nuclei and allow cloudy condensation to take place where there was no dust. Under certain conditions the sun gives rise to a great increase in the number of nuclei. Accordingly, he has carefully tested a few of the ordinary constituents and impurities in our atmosphere to see if sunshine acted on them in such a way as to make them probable formers of cloud-particles. He tested various gases, with more or less success. He found that ordinary air, after being deprived of its dust-particles and exposed to sunshine, does not show any cloudy condensation on expansion; but, when certain gases are in the dustless air, a very different result is obtained. He first used ammonia, putting one drop into six cubic inches of water in a flask, and sunning this for one minute; the result was a considerable quantity of condensation, even with such a weak solution. When the flask was exposed for five minutes, the condensation by the action of the sunshine was made more dense. Hydrogen peroxide was tested in the same way, and it was found to be a powerful generator of nuclei. Curious is it that sulphurous acid is puzzling to the experimentalist for cloud formation. It gives rise to condensation in the dark; but sunshine very conclusively increases the condensation. Chlorine causes condensation to take place without supersaturation; sulphuretted hydrogen (which one always associates with the smell of rotten eggs) gives dense condensation after being exposed to sunshine. Though the most of these nuclei, due to the action of sunshine in the gases, remain active for cloudy condensation for a comparatively short space of time--fifteen minutes to half-an-hour--yet the experiments show that it is possible for the cloudy condensation to take place in certain circumstances in the absence of dust. This seems paradoxical in the light of the former beautiful experiments; but, in ordinary circumstances, dust is needed for the formation of clouds. However, supposing there is any part of the upper air free from dust, it is now found possible, when any of these gases experimented on be present, for the sun to convert them into nuclei of condensation, and permit of clouds being formed in dustless air, miles above the surface of the earth. In the lower atmosphere there are always plenty of dust-particles to form cloudy condensation, whether the sun shines or not. These are produced by the waste from the millions of meteors that daily fall into the air. But in the higher atmosphere, clouds can be formed by the action of the sun's rays on certain gases. This is a great boon to us on the earth; for it assures us of clouds being ever existing to defend us from the sun's extra-powerful rays, even when our atmosphere is fairly clear. This is surely of some meteorological importance. CHAPTER X DECAY OF CLOUDS From the earliest ages clouds have attracted the attention of observers. Varied are their forms and colours, yet in our atmosphere there is one law in their formation. Cloud-particles are formed by the condensation of water-vapour on the dust-particles invisibly floating in the atmosphere, up to thousands--and even millions--in the cubic inch of air. But observers have not directed their attention so much to the decay of clouds--in fact, the subject is quite new. And yet how suggestive is the subject! The process of decay in clouds takes place in various ways. A careful observer may witness the gradual wasting away and dilution into thin air of even great stretches of cloud, when circumstances are favourable. In May 1896 my attention was particularly drawn to this at my manse in Strathmore. In the middle of that exceptionally sultry month, I was arrested by a remarkable transformation scene. It was the hottest May for seventy-two years, and the driest for twenty-five years. The whole parched earth was thirsting for rain. All the morning my eyes were turned to the clouds in the hope that the much-desired shower should fall. Till ten o'clock the sun was not seen, and there was no blue in the sky. Nor was there any haze or fog. But suddenly the sun shone through a thinner portion of the enveloping clouds, and, to the north, the sky began to open. As if by some magic spell there was, in a quarter of an hour, more blue to be seen than clouds. At the same time, near the horizon, a haze was forming, gradually becoming denser as time wore on. In an hour the whole clouds were gone, and the glorious orb of day dispelled the moisture to its thin-air form. This was a pointed and rapid illustration of the decay from cloud-form to haze, and then to the pure vapoury sky. It was an instance of the _reverse_ process. As the sun cleared through, the temperature in the cloud-land rose and evaporation took place on the surface of the cloud-particles, until by an untraceable, but still a gradual process through fog, the haze was formed. Even then the heat was too great for a definite haze, and the water-vapour returned to the air, leaving the dust-particles in invisible suspension. But clouds decay in another way. This I will illustrate in the next chapter on "It always rains." What strikes a close observer is the difference of structure in clouds which are in the process of formation and those which are in the process of decay. In the former the water-particles are much smaller and far more numerous than in the latter. While the particles in clouds in decay are large enough to be seen with the unaided eye, when they fall on a properly lighted measuring table, they are so small in clouds in rapid formation that the particles cannot be seen without the aid of a strong magnifying glass. Observers have assumed that the whole explanation of the fantastic shapes taken by clouds is founded on the process of formation; but Dr. Aitken has pointed out that ripple-marked clouds, for instance, have been clouds of decay. When what is called a cirro-stratus cloud--mackerel-like against the blue sky--is carefully observed in fine weather, it will be found that it frequently changes the ripple-marked cirrus in the process of decay to vanishing. Where the cloud is thin enough to be broken through by the clear air that is drawn in between the eddies, the ripple markings get nearer and nearer the centre, as the cloud decays. And, at last, when nearly dissolved, these markings are extended quite across the cloud. Whether, then, we consider the cases of clouds gradually melting away back into their original state of blue water-vapour, or the constant fine raining from clouds and re-formation by evaporation, or the transformation of such clouds as the cirro-stratus into the ripple-marked cirrus, we are forced to the conclusion that in clouds there is not always development, but sometimes degeneration; not always formation, but sometimes decay. CHAPTER XI IT ALWAYS RAINS All are familiar with the answer given by the native of Skye to the irate tourist on that island, who, for the sixth day drenched, asked the question: "Does it always rain here?" "Na!" answered the workman, without at all understanding the joke; "feiles it snaas" (sometimes it snows). Yet, strange to say, the tourist's question has been answered in the affirmative in every place where a cloud is overhead, visible or invisible. Whenever a cloud is formed, it begins to rain; and the drops shower down in immense numbers, though most minute in size--"the playful fancies of the mighty sky." No doubt it is only in certain circumstances that these drops are attracted together so as to form large drops, which fall to the earth in genial showers to refresh the thirsty soil, or in a terrible deluge to cause great destruction. But when the temperature and pressure are not suitable for the formation of what we commonly know as the rain, the fine drops fall into the air under the cloud, where they immediately evaporate from their dust free-surfaces, if the air is dry and warm. This is, in other words, the decay of clouds. It is a curious fact that objects in a fog may not be wetted, when the number of water-particles is great. It seems that these water-particles all evaporate so quickly that even one's hand or face is not sensible of being wetted. The particles are minutely small; and they may evaporate even before reaching the warm skin, by reason of the heated air over the skin. There is a peculiarly warm sensation in the centre of a cumulus cloud, especially when it is not dense. A glow of heat seems to radiate from all points. Yet the face and hands are quite dry, and exposed objects are not wetted; but it is really _always raining_. That is a curious discovery. It is radiant heat that is the cause of the remarkable result. The rays of the sun, which strike the upper part of the cloud, not only heat that surface but also penetrate the cloud and fall on the surface of bodies within, generating heat there. These heated surfaces again radiate heat into the air attached to them. This warm air receives the fine raindrops in the cloud, and dissolves the moisture from the dust-particles before the moisture can reach the surfaces exposed. That a vast amount of radiant heat rushes through a cloud is clearly shown by exposing a thermometer with black bulb _in vacuo_. On some occasions, a thermometer would indicate from 40° to 50° above the temperature of the air, thus proving the surface to be quite dry. These observations have been corroborated on Mount Pilatus, near Lucerne--1000 feet higher and more isolated than the Rigi. The summit was quite enveloped in cloud, and, though one might naturally conclude that the air was dense with moisture, yet the wooden seats, walls, and all exposed surfaces were quite dry. Strange to say, however, the thermometers hung up got wet rapidly, and the pins driven into the wooden post to support them rapidly became moist. A thermometer lying on a wooden seat stood at 60°, while one hung up read only 48°. This difference was caused by radiant heat. It is well known that, when bodies are exposed to radiant heat, they are heated in proportion to their size; the smaller, then, may be moist, when the larger are dry by radiation. The effect of the sun's penetrating heat through the cloud is to heat exposed objects above the temperature of the air; and if the objects are of any size they are considerably heated, and retain their heat more, while at the same time around them is a layer of warm air which is quite sufficient to force the water-vapour to leave the dust-particles in the fine rain. Hence seats, walls, posts, &c., are quite dry, though they are in the middle of a cloud. They are large enough to throw off the moisture by the retained heat, or by the large amount of surrounding heat; whereas, small bodies, which are not heated to the same degree and cannot therefore retain their heat so easily, have not heat-power sufficient to withstand the moisture, and they become wetted. Hence, by the radiant heat, the large exposed objects are dry in the cloud; whereas small objects are damp, and, in some cases, dripping with wet. The fact is, then, that whenever a cloud overhangs, _rain is falling_, though it may not reach the earth on account of the dryness of the stratum of air below the cloud, and the heat of the air over the earth. So that on a summer day, with the gold-fringed, fleecy clouds sailing overhead, it is really raining; but the drops, being very small, evaporate long before reaching the earth. As Ariel sings at the end of "The Tempest" of Shakespeare, "The rain, it raineth every day." It rains, but much of the melting of the clouds is reproduced by a wonderful circularity--the moisture evaporating, seizing other dust-particles, forming cloud-particles, falling again, and so on _ad infinitum_, during the existing circumstances. CHAPTER XII HAZE What is haze? The dictionary says, "a fog." Well, haze is _not_ a fog. In a fog, the dust-particles in the air have been fully clothed with water-vapour; in a haze, the process of condensation has been arrested. Cloudy condensation is changed to haze by the reduction of its humidity. Dr. Aitken invented a simple apparatus for testing the condensing power of dust, and observing if water-vapour condensed on the deposited dust in unsaturated air. The dust from the air has first to be collected. This is done by placing a glass plate vertically, and in close contact with one of the panes of glass in the window, by means of a little india-rubber solution. The plate being thus rendered colder than the air in the room, the dust is deposited on it. Construct a rectangular box, with a square bottom, 1-1/2 inches a side and 3/4 inch deep, and open at the top. Cover the top edge of the box with a thickness of india-rubber. Place the dusty plate--a square glass mirror, 4 inches a side--on the top of the india-rubber, and hold it down by spring catches, so as to make the box water-tight. The box has been provided with two pipes, one for taking in water and the other for taking away the overflow, with the bulb of a thermometer in the centre. Clean the dust carefully off one half of the mirror, so that one half of the glass covering the box is clean and the other half dusty. Pour cold water through the pipe into the box, so as to lower the temperature of the mirror, and carefully observe when condensation begins on the clean part and on the dusty part, taking a note of the difference of temperature. The condensation of the water-vapour will appear on the dust-particles before coming down to the natural dew-point temperature of the clean glass. And the difference between the two temperatures indicates the temperature above the dew-point at which the dust has condensed the water-vapour. Magnesia dust has small affinity for water-vapour; accordingly, it condenses at almost exactly the same temperature as the glass. But gunpowder has great condensing power. All have noticed that the smoke from exploded gunpowder is far more dense in damp than in dry weather. In the experiment it will be found that the dust from gunpowder smoke begins to show signs of condensing the vapour at a temperature of 9° Fahr. above the dew-point. In the case of sodium dust, the vapour is condensed from the air at a temperature of 30° above the dew-point. Dust collected in a smoking-room shows a decidedly greater condensing power than that from the outer air. We can now understand why the glass in picture frames and other places sometimes appears damp when the air is not saturated. When in winter the windows are not often cleaned, a damp deposit may be frequently seen on the glass. Any one can try the experiment. Clean one half of a dusty pane of glass in cold weather, and the clean part will remain undewed and clear, while the dusty part is damp to the eye and greasy to the touch. These observations indicate that moisture is deposited on the dust-particles from air, which is not saturated, and that the condensation takes place while the air is comparatively dry, _before_ the temperature is lowered to the dew-point. There is, then, no definite demarcation between what seems to us clear air and thick haze. The clearest air has some haze, and, as the humidity increases, the thickness of the air increases. In all haze the temperature is above the dew-point. The dust-particles have only condensed a very small amount of the moisture so as to form haze, before the fuller condensation takes place at the dew-point. At the Italian lakes, on many occasions when the air is damp and still, every stage of condensation may be observed in close proximity, not separated by a hard and fast line, but when no one could determine where the clear air ended and the cloud began. Sometimes in the sky overhead a gradual change can be observed from perfect clearness to thick air, and then the cloud. A thick haze may be occasioned by an increased number of dust-particles with little moisture, or of a diminished number of dust-particles with much moisture, above the point of saturation. The haze is cleared by this temperature rising, so as to allow the moisture to evaporate from the dust-particles. Whenever the air is dry and hazy, much dust is found in it; as the dust decreases the haze also decreases. For example, Dr. Aitken, at Kingairloch, in one of the clearest districts of Argyleshire, on a clear July afternoon, counted 4000 dust-particles in a cubic inch of the air; whereas, two days before, in thick haze, he counted no fewer than 64,000 in the cubic inch. At Dumfries the number counted on a very hazy day in October increased twenty-fold over the number counted the day before, when it was clear. All know that thick haze is usual in very sultry weather. The wavy, will-o'-the-wisp ripples near the horizon indicate its presence very plainly. During the intense heat there is generally much dust in the atmosphere; this dust, by the high temperature, attracts moisture from the apparently dry air, though above the saturation point. In all circumstances, then, the haze can be accounted for by the condensing power of the dust-particles in the atmosphere, at a higher temperature than that required for the formation of fogs, or mists, or rain. CHAPTER XIII HAZING EFFECTS OF ATMOSPHERIC DUST The transparency of the atmosphere is very much destroyed by the impurities communicated to it while passing over the inhabited areas of the country. Dr. Aitken devoted eighteen months to compare the amount of dusty impurities in different masses of air, or of different airs brought in by winds from different directions. He took Falkirk for his centre of observations. This town lies a little to the north of a line drawn between Edinburgh and Glasgow, and is nearly midway between them. If we draw a line due west from it, and another due north, we find that, in the north-west quadrant so enclosed, the population of that part of Scotland is extremely thin, the country over that area being chiefly mountainous. In all other directions, the conditions are quite different. In the north-east quadrant are the fairly well-populated areas of Aberdeenshire, Forfarshire, and the thickly populated county of Fife. In the south-east quadrant are situated Edinburgh and the well-populated districts of the south-east of Scotland. And in the south-west quadrant are Glasgow and the large manufacturing towns which surround it. The winds from three of these quadrants bring air polluted in its passage over populated areas, whereas the winds from the north-west come comparatively pure. The general plan of estimating the amount of haze is to note the most distant hill that can be seen through the haze. The distance in miles of the farthest away hill visible is then called "the limit of visibility" of the air at the time. For the observations made at Falkirk, only three hills are available, one about four miles distant, the Ochils about fifteen miles distant, and Ben Ledi about twenty-five miles distant--all in the north-west quadrant. When the air is thick, only the near hill can be seen; then the Ochils become visible as the air clears; and at last Ben Ledi is seen, when the haze becomes still less. After Ben Ledi is visible, it then becomes necessary to estimate the amount of haze on it, in order to get the limit of visibility of the air at the time. Thus, if Ben Ledi be half-hazed, then the limit of visibility will be fifty miles. In this way all the estimates of haze have been reduced to one scale for comparison. As the result of all the observations it was found that, as the dryness of the air increases, the limit of visibility also increases. A very marked difference in the transparency of the air was found with winds from the different directions. In the north-west quadrant the winds made the air very clear, whereas winds from all other directions made the air very much hazed. The winds in the other three areas are nearly ten times more hazed than those from the north-west quadrant. That is very striking. The conclusion come to is that the air from densely inhabited districts is so polluted that it is fully nine times more hazed than the air that comes from the thinly inhabited districts; in other words, the atmosphere at Falkirk is about ten times thicker when the wind is east or south than it would be if there were no fires and no inhabitants. It is interesting to notice that the limit varies considerably for the same wind at the same humidity. This is what might have been expected, because from the observations made by the dust-counter the number of particles varied greatly in winds from the same directions, but at different times. This depends upon the rise and fall of the wind, changes in the state of trade, season of the year, and other causes. During a strike, the dearth of coal will make a considerable diminution in the number of dust-particles in the air of large towns. With a north wind, the extreme limits of visibility are 120 to 200 miles; and with a north-west wind, from 70 to 250 miles. An east wind has as limits 4 to 50 miles, and a south-east wind 2 to 60 miles. One interesting fact to be noticed, after wading through these tables, is this--that, as a general result, the transparency of the air increases about 3·7 times for any increase in dryness from 2° to 8° of wet-bulb depression. That is, the clearness of the air is inversely proportional to the relative humidity; or, put another way, if the air is four times drier it is about four times clearer. CHAPTER XIV THUNDER CLEARS THE AIR The phrase "thunder clears the air" is familiar to all. It contains a very vital truth, yet even scientific men did not know its full meaning until just the other day. It came by experience to people who had been for ages observing the weather; and it is one of the most pointed of the "weather-lore" expressions. Folks got to know, by a sort of rule-of-thumb, truths which scientifically they were unable to learn. And this is one. Perhaps, therefore, we should respect a little more what is called "folk-lore," or ordinary people's sayings. Experience has taught men many wonderful things. In olden times they were keener natural observers. They had few books, but they had plenty of time. They studied the habits of animals and moods of nature, and they came wonderfully near to reaching the full truth, though they could not give a reason for it. The awe-inspiring in nature has especially riveted the attention of man. And no appearance in nature joins more powerfully the elements of grandeur and awe than a heavy thunder-storm. When, suddenly, from the breast of a dark thunder-cloud a brilliant flash of light darts zigzag to the earth, followed by a loud crackling noise which softens in the distance into weaker volumes of sound, terror seizes the birds of the air and the cattle in the field. The man who is born to rule the storm rejoices in the powerful display; but kings have trembled at the sight. Byron thus pictures a storm in the Alps:-- "Far along From peak to peak, the rattling crags among Leaps the live thunder! Not from one lone cloud, But every mountain now hath found a tongue, And Jura answers, through her misty shroud, Back to the joyous Alps, who call to her aloud!" Franklin found that lightning is just a kind of electricity. No one can tell how it is produced; yet a flash has been photographed. When the flash is from one cloud to another there is sheet-lightning, which is beautiful but not dangerous; but, when the electricity passes from a cloud to the earth in a forked form, it is very dangerous indeed. The flash is instantaneous, but the sound of the thunder takes some time to travel. Roughly speaking, the sound takes five seconds or six beats of the pulse to the mile. All are now taught at school that it is the oxygen in the air which is necessary to keep us in life. If mice are put into a glass jar of pure oxygen gas, they will at once dance with exhilarating joy. It occurred to Sir Benjamin Richardson, some time ago, that it would be interesting to continue some experiments with animals and oxygen. He put a number of mice into a jar of pure oxygen for a time; they breathed in the gas, and breathed out water-vapour and carbonic acid. After the mice had continued this for some time, he removed them by an arrangement. By chemical means he removed the water-vapour and carbonic acid from the mixed air in the vessel. When a blown-out taper was inserted, it at once burst into flame, showing that the remaining gas was oxygen. Again, the mice were put into this vessel to breathe away. But, strange to say, the animals soon became drowsy; the smartness of the oxygen was gone. At last they died; there was nothing in the gas to keep them in life; yet, by the ordinary chemical tests, it was still oxygen. It had repeatedly passed through the lungs of the mice, and during this passage there had been an action in the air-cells which absorbed the life-giving element of the gas. It is oxygen, so far as chemistry is concerned, but it has no life-giving power. It has been _devitalised_. But the startling discovery still remains. Sir Benjamin had previously fitted up the vessel with two short wires, opposite each other in the sides--part outside and part inside. Two wires are fastened to the outside knobs. These wires are attached to an electric machine, and a flash of electricity is made to pass between the inner points of the vessel. The wires are again removed; nothing strange is seen in the vessel. But, when living mice are put into the vessel, they dance as joyfully as if pure oxygen were in it. The oxygen in which the first mice died has now been quite refreshed by the electricity. The bad air has been cleared and made life-supporting by the electric discharge. It has been again vitalised. Now, to apply this: before a thunder-storm, everything has been so still for days that the oxygen in the air has been to some extent robbed of its life-sustaining power. The air feels "close," a feeling of drowsiness comes over all. But, after the air has been pierced by several flashes of lightning, the life-force in the air is restored. Your spirits revive; you feel restored; your breathing is far freer; your drowsiness is gone. Then there is a burst of heavenly music from the exhilarated birds. Thus a thunder-storm "clears the air." After the passage of lightning through the air ozone is produced--the gas that is produced after a flash of electricity. It is a kind of oxygen, with fine exciting effects on the body. If, then, the life-sustaining power of oxygen depends on a trace of ozone, and this is being made by lightning's work, how pleased should we be at the occasional thunder-storm! CHAPTER XV DISEASE-GERMS IN THE AIR The gay motes that dance in the sunbeams are not all harmless. All are annoying to the tidy housekeeper; but some are dangerous. There are living particles that float in the air as the messengers of disease and death. Some, falling on fresh wounds, find there a suitable feeding-place; and, if not destroyed, generate the deadly influence. Others are drawn in with the breath; and, unless the lungs can withstand them, they seize hold and spread some sickness or disease. From stagnant pools, common sewers, and filthy rooms, disease-germs are constantly contaminating the air. Yet these can be counted. The simplest method is that of Professor Frankland. It depends on this principle: a certain quantity of air is drawn through some cotton-wool; this wool seizes the organisms as the air passes through; these organisms are afterwards allowed to feed upon a suitable nutritive medium until they reach maturity; they are then counted easily. About an inch from each end of a glass tube (5 inches long and 1 inch bore), the glass is pressed in during the process of blowing. Some cotton-wool is squeezed in to form a plug at the farther constricted part of the glass. The important plug is now inserted at the same open end, but is not allowed to go beyond the constricted part at its end. A piece of long lead tubing is attached to the former end by an india-rubber tube. The other end of the lead tubing is connected with an exhausting syringe. Sixty strokes of the 18 cubic inches syringe will draw 1080 cubic inches of the air to be examined through the plugs, the first retaining the organisms. The impregnated plug is then put into a flask containing in solution some gelatine-peptone. The flask is made to revolve horizontally until an almost perfectly even film of gelatine and the organisms from the broken-up plug cover its inner surface. The flask is allowed to remain for an hour in a cool place, and is then placed under a bell-jar, at a temperature of 70° Fahr. There it remains, to allow the germs to incubate, for four or five days. The surface of the flask having been previously divided into equal parts by ink lines, the counting is now commenced. If the average be taken for each segment, the number of the whole is easily ascertained. A simple arithmetical calculation then determines the number of organisms in a cubic foot, since the number is known for the 1080 cubic inches. That is the process for determining the number of living organisms in a fixed quantity of air. No less than thirty colonies of organisms were counted in a cubic foot of air taken from the Golden Gallery of St. Paul's Cathedral, London, and 140 from the air of the churchyard. An ordinary man would breathe there thirty-six micro-organisms every minute. Electricity has a powerful effect in destroying these organisms. Ozone is generated in the air by lightning, and it is detrimental to them. In fine ozoned Highland air scarcely a disease-germ can be detected. Open sea air contains about one germ in two cubic feet. It has been found that in Paris the average in summer is about 140 per cubic foot of air, but in bedrooms the number is double. During the twenty-four hours of the day the number of germs is highest about 6 A.M., and lowest about mid-day. Raindrops carry the germs to the ground. Hence the advantage of a thunder plout in a sanitary way. A cubic foot of rain has been found to contain 5500 organic dust-germs, besides 7,000,000,000 of inorganic dust-particles. In a dirty town the rain will bring down in a year, upon a square foot of surface, no less than 3,000,000 of bacteria, many of them being disease-bearing and death-bearing. No wonder, then, that scientific men are using every endeavour to protect the human frame, as well as the frame of the lower animals, from the baneful inroads of these floating nuclei of disease and death. CHAPTER XVI A CHANGE OF AIR For weakness of body and fatigue of mind a very common and essentially serviceable recommendation is "a change of air." Of course, the change of scene from coast to country, or from town to hillside, may help much the depressed in body or mind; and this is very commendable. But, strange to say, there is a healing virtue in breathing different air. At first one is apt to think that air is the same all over, as he thinks water is--especially outside smoky towns; but both have varied qualities in different parts. You have only to be assured that in a cubic inch of bedroom air in the denser parts of a large town there are about 20,000,000 of dust-particles, and in the open air of a heathery mountain-side there are only some hundreds, to see that there is something after all on the face of it in the "old wives' saw." Not that the dust-particles are all injurious; for most of them are inorganic, and many of the organic particles are quite wholesome; yet there is a change wrought, often very marked, in going from one place to another for different air. Even in the country, especially in summer-time, one distinctly notices the great difference in the air of lowland and highland localities. The ten miles change from Strathmore to Glenisla shows a marked difference in the air. Below, it is close, weakening, enervating; above, it is exhilarating, invigorating, and strong. So people must have a change--at least those who can afford it--for health must be seen to first of all, if one has means to do so. Oh! the blessing of good health! How many who enjoy it never think of the misery of its loss! In fact, health is the soul that animates all enjoyments of life; for without it those would soon be tasteless. A man starves at the best-spread table, and is poor in the midst of the greatest treasures without health. In these days half of our diseases come from the neglect of the body in the overwork of the brain. The wear and tear of labour and intellect go on without pause or self-pity. Men may live as long as their forefathers, but they suffer more from a thousand artificial anxieties and cares. The men of old fatigued only the muscles, we exhaust the finer strength of the nerves. Even more so now, then, do we require a change of air to soothe our overwrought nervous system. And when that magic power, concealed from mortal view, works such wonders on the health, surely it is one's duty to save up and have it, when it is within one's means. For is not health the greatest of all possessions? What a rich colour clothes the countenance of the young after a month's outing in the hill country! How fine and pure has the blood become! All stagnant humours, accumulated in winter town life, have been dispelled by the ozone-brightening charm. The weary looking office or shop man is now transfigured into a sprightly youth once more, ready with strongly recuperated power for another winter's labours. The pale wife, who has been stifled for months in close-aired rooms, has now a healthy flush on her becoming countenance that speaks of gladly restored health. And all this has been brought about by a "change of air"! For a thorough change to a town man, he should make for the Highlands. There he is never tired of walking, for the air which he breathes is full of ozone. This revivifying element in the air is produced by the lightning-bursts from hill to hill. There is in the Highlands a continual rush of electricity, whether seen or not. Hence the air is very pure, free from organic germs, intensely exhilarating and buoyant. Sportsmen are livingly aware of the recuperative power of the Highland air. Perhaps these city men do not benefit so much by the easy walking exercise on the grouse moors as in breathing the splendidly delight-inspiring air. What a change one feels there in a very few hours! "A change of air" is an old wives' adage. But much of the weather-lore of our forefathers was based on real scientific principles only now coming to light. Nature is ever true, but it requires patience to unravel her secrets. We therefore advocate an occasional "change of air" to improve the health-- "The chiefest good, Bestow'd by Heaven, but seldom understood." CHAPTER XVII THE OLD MOON IN THE NEW MOON'S ARMS After the sun's broad beams have tired the sight, the moon with more sober light charms us to descry her beauty, as she shines sublimely in her virgin modesty. There is always a most fascinating freshness in the first sight of the new moon. The superstition of centuries adds to this charm. Why boys and girls like to turn over a coin in their pocket at this sight one cannot tell: yet it is done. No young lady likes to look at the new moon through a pane of glass. And farmers are always confident of a change of weather with a new moon: at least in bad weather they earnestly hope for it. But, banishing all superstition, we welcome the pale silver sickle in the heavens, once more appearing from the bosom of the azure. And no language can equal these beautiful words of the youthful Shelley:-- "Like the young moon, When on the sunlit limits of the night Her white shell trembles amid crimson air, And while the sleeping tempest gathers might, Doth, as the herald of his coming, bear The ghost of its dead mother, whose dim form Bends in dark ether from her infant's chair." That is a more charming way of putting the ordinary expression, "the old moon in the new moon's arms." We are regularly accustomed to the moonshine, but only occasionally is the _earthshine_ on the moon so regulated that the shadowed part is visible. This is not seen at the appearance of every new moon. It depends upon the positions of the sun and moon, the state of the atmosphere, and the absence of heavy clouds. I never in my life saw the phenomenon so marvellously beautiful as on May 7th, 1894, at my manse in Strathmore. I took particular note of it, as some exceedingly curious things were connected with it. At nine o'clock in the evening, the new moon issued from some clouds in the western heavens, the sun having set, about an hour before. The crescent was thin and silvery, and the outline of the shadowed part was just visible. The sky near the horizon was clear and greenish-hued. As the night advanced the moon descended, and at ten o'clock she was approaching a purple stratum of clouds that stretched over the hills, while the position of the sun was only known a little to the east, by the back-thrown light upon the dim sky. Through the moisture-laden air the sun's rays, reflected by the moon, threw a golden stream from the crescent moon, for the silvery shell became more golden-hued. The horns of the moon now seemed to project, and the shadowed part became more distinct, though the circle appeared smaller. By means of a field-glass I noticed that this was extra lighted, with points here and there quite golden-tinged. The darker spots showed the deep caverns; the brighter points brought into relief the mountain peaks. Why was the surface brighter than usual? I cannot go into detail about the phases of the moon; but, in a word, I may say that, while the sun can illuminate the side of the moon turned towards it, it is unable to throw any light on the shadow, seeing that there is no atmosphere around the moon to refract the light. If we, in imagination, looked from the moon upon the earth, we should see the same phases as are now noticed in the moon; and when it is just before new moon on the earth, the earth will appear fully illuminated from the moon. We would also observe (from the moon) that the brightness of the illuminated part of the earth would vary from time to time, according to the changes in the earth's atmosphere. More light would be reflected to the moon from the clouds in our atmosphere than from the bare earth or cloudless sea, since clouds reflect more light than either land or sea. Accordingly, we arrive at this curious fact--that the extra brightness of the _dark_ body of the moon is mainly determined by the amount of _cloud in our atmosphere_. Accordingly, I concluded that there must be clouds to the west, though I could not see them, which reflected rays of light and faintly illuminated the shadowed part of the moon. It had become much colder, and I concluded that during the night the cloud-particles, if driven near by the wind, would condense into rain. And, assuredly, next morning I was gratified to find that rain had fallen in large quantities, substantiating the theory. There is much pleasure in verifying such an interesting problem. The dark body of the moon being more than usually visible is one of our well-known and oldest indications of coming bad weather. And at once came to my memory the lines of Sir Patrick Spens, as he foreboded rain for his crossing the North Sea:-- "I saw the new moon late yestreen Wi' the auld moon in her arm; And if we gang to sea, master, I fear we'll come to harm." This lunar indication, then, has a sound physical basis, showing that near the observer there are vast areas of clouds, which are reflecting light upon the moon at the time, before they condense into rain by the chilling of the air. According to the old Greek poet, Aratus: "If the new moon is ruddy, and you can trace the shadow of the complete circle, a storm is approaching." CHAPTER XVIII AN AUTUMN AFTERGLOW A brilliant afterglow is welcomed for its surpassing beauty and a precursor of fine fixed weather. A glorious sunset has always had a charm for the lover of nature's beauties. The zenith spreads its canopy of sapphire, and not a breath creeps through the rosy air. A magnificent array of clouds of numberless shapes come smartly into view. Some, far off, are voyaging their sun-bright paths in silvery folds; others float in golden groups. Some masses are embroidered with burning crimson; others are like "islands all lovely in an emerald sea." Over the glowing sky are splendid colourings. The flood of rosy light looks as if a great conflagration were below the horizon. I remember witnessing an especially brilliant sunset last autumn on the high-road between Kirriemuir and Blairgowrie. The setting sun shone upon the back of certain long trailing clouds which were much nearer me than a range behind. The fringes of the front range were brilliantly golden, while the face of those behind was sparklingly bright. Then the sun disappeared over the western hills, and his place was full of spokes of living light. Looking eastward, I observed on the horizon the base of the northern line of a beautiful rainbow--"the shepherd's delight" for fine weather. Soon in the west the light faded; but there came out of the east a lovely flush, and the general sky was presently flamboyant with afterglow. The front set of clouds was darker except on the edges, the red being on the clouds behind; and the horizon in the east was particularly rich with dark red hues. Gradually the eastern glow rose and reddened all the clouds, but the front clouds were still grey. The effect was very fine in contrast. The fleecy clouds overhead became transparently light red, as they stretched over to reach the silver-streaked west. The new moon was just appearing upright against a slightly less bright opening in the sky, betokening the firm hardness of autumn. Soon the colouring melted away, and the peaceful reign of the later twilight possessed the land. Now why that brilliancy of the east, when the west was colourless? Most of all you note the immense variety and wealth of reds. These are due to dust in the atmosphere. We are the more convinced of this by the very remarkable and beautiful sunsets which occurred after the tremendous eruption at Krakatoa, in the Straits of Sunda, thirty years ago. There was then ejected an enormous quantity of fine dust, which spread over the whole world's atmosphere. So long as that vast amount of dust remained in the air did the sunsets and afterglows display an exceptional wealth of colouring. All observers were struck with the vividly brilliant red colours in all shades and tints. The minute particles of dust in the atmosphere arrest the sun's rays and scatter them in all directions; they are so small, however, that they cannot reflect and scatter all; their power is limited to the scattering of the rays at the blue end of the spectrum, while the red rays pass on unarrested. The display of the colours of the blue end are found in numberless shades, from the full deep blue in the zenith to the greenish-blue near the horizon. If there were no fine dust-particles in the upper strata, the sunset effect would be whiter; if there were no large dust-particles, there would be no colouring at all. If there were no dust-particles in the air at all, the light would simply pass through into space without revealing itself, and the moment the sun disappeared there would be total darkness. The very existence of our twilight depends on the dust in the air; and its length depends on the amount and extension upwards of the dust-particles. But how have the particles been increased in size in the east? Because, as the sun was sinking, but before its rays failed to illumine the heavens, the temperature of the air began to fall. This cooling made the dust-particles seize the water-vapour to form haze-particles of a larger size. The particles in the east first lose the sun's heat, and first become cool; and the rays of light are then best sifted, producing a more distinct and darker red. As the sun dipped lower, the particles overhead became a turn larger, and thereby better reflected the red rays. Accordingly, the roseate bands in the east spread over to the zenith, and passed over to the west, producing in a few minutes a universal transformation glow. To produce the full effect often witnessed, there must be, besides the ordinary dust-particles, small crystals floating in the air, which increase the reflection from their surfaces and enhance the glow effects. In autumn, after sunset, the water-covered dust-particles become frozen and the red light streams with rare brilliancy, causing all reddish and coloured objects to glow with a rare brightness. Then the air glows with a strange light as of the northern dawn. From all this it is clear that, though the colouring of sunset is produced by the direct rays of the sun, the afterglow is produced by reflection, or, rather, radiation from the illuminated particles near the horizon. The effect in autumn is a stream of red light, of varied tones, and rare brilliancy in all quarters, unseen during the warmer summer. We have to witness the sunsets at Ballachulish to be assured that Waller Paton really imitated nature in the characteristic bronze tints of his richly painted landscapes. CHAPTER XIX A WINTER FOREGLOW Little attention has been paid to foreglows compared with afterglows, either with regard to their natural beauty or their weather forecasting. But either the ordinary red-cloud surroundings at sunrise, or the western foreglow at rarer intervals, betokens to the weather-prophet wet and gloomy weather. The farmer and the sailor do not like the sight, they depend so much on favourable weather conditions. Of course, sunrise to the æsthetic observer has always its charms. The powerful king of day rejoices "as a bridegroom coming out of his chamber" as he steps upon the earth over the dewy mountain tops, bathing all in light, and spreading gladness and deep joy before him. The lessening cloud, the kindling azure, and the mountain's brow illumined with golden streaks, mark his approach; he is encompassed with bright beams, as he throws his unutterable love upon the clouds, "the beauteous robes of heaven." Aslant the dew-bright earth and coloured air he looks in boundless majesty abroad, touching the green leaves all a-tremble with gold light. But glorious, and educating, and inspiring as is the sunrise in itself in many cases, there is occasionally something very remarkable that is connected with it. Rare is it, but how charming when witnessed, though till very recently it was all but unexplained. This is the _foreglow_. It is in no respect so splendid as the afterglow succeeding sunset; but, because of its comparative rarity, its beauty is enhanced. I remember a foreglow most vividly which was seen at my manse, in Strathmore, in January 1893. My bedroom window looked due west; I slept with the blind up. On that morning I was struck, just after the darkness was fading away, with a slight colouring all along the western horizon. The skeleton branches of the trees stood out strongly against it. The colouring gradually increased, and the roseate hue stretched higher. The old well-known faces that I used to conjure up out of the thin blended boughs became more life-like, as the cheeks flushed. There was rare warmth on a winter morning to cheer a half-despairing soul, tired out with the long hours of oil reading, and pierced to the heart by the never-ceasing rimes; yet I could not understand it. I went to the room opposite to watch the sunrise, for I had observed in the diary that the appearance of the sun would not be for a few minutes. There were streaks of light in the east above the horizon, but no colour was visible. That hectic flush--slight, yet well marked--which was deepening in the western heavens, had no counterpart in the east, except the colourless light which marked the wintry sun's near approach. As soon as the sun's rays shot up into the eastern clouds, and his orb appeared above the horizon, the western sky paled, the colour left it, as if ashamed of its assumed glory. A foreglow like that I have very rarely seen, and its existence was a puzzle to me till I studied Dr. Aitken's explanation of the afterglows after sunset. I had never come across any description of a foreglow; and, of course, across no explanation of the curious phenomenon. The western heavens were coloured with fairly bright roseate hues, while the eastern horizon was only silvery bright before the sun rose; whereas, after the sun appeared and coloured the eastern hills and clouds, the western sky resumed its leaden grey and colourless appearance. Why was that? What is the explanation? I have not space enough to repeat the explanation given already in the last chapter of the glorious phenomenon of the afterglow. But the explanation is similar. Before sunrise, the rays of the sun are reflected by dust-particles in the zenith to the western clouds. The colouring is intensified by the frozen water-vapour on these particles in the west. One thing I carefully noted. Ere mid-day, snow began to fall, and for some days a severe snow-storm kept us indoors. Then, at any rate, the foreglow betokened a coming storm. It was, like a rainbow in a summer morning, a decided warning of the approaching wet weather. CHAPTER XX THE RAINBOW The poet Wordsworth rapturously exclaimed-- "My heart leaps up when I behold A rainbow in the sky." And old and young have always been enchanted with the beautiful phenomenon. How glorious is the parti-coloured girdle which, on an April morning or September evening, is cast o'er mountain, tower, and town, or even mirrored in the ocean's depths! No colours are so vividly bright as when this triumphal arch bespans a dark nimbus: then it unfolds them in due prismatic proportion, "running from the red to where the violet fades into the sky." A plain description of the formation of the rainbow is not very easily given, but a short sketch may be useful. Beautiful as is the ethereal bow, "born of the shower and colour'd by the sun," yet the marvellous effect is more exquisitely intensified in its gorgeous display when the hand of science points out the path in which the sun's rays, from above the western horizon, fall on the watery cloud, indicating fine weather--"the shepherd's delight." One law of reflection is that, when a ray of light falls on a plane or spherical surface, it goes off at the same angle to the surface as it fell. One law of refraction is that, when a ray of light passes through one medium and enters a denser medium (as from air to water), it is bent back a little. By refraction you see the sun's rays long after the sun has set; when the sun is just below the horizon, an observer, on the surface of the earth, will see it raised by an amount which is generally equal to its apparent diameter. The rays of different colours are bent back (when passing through the water) at different rates, some slightly, others more, from the red to the violet end. The rainbow, then, is produced by refraction and reflection of the several coloured rays of sunlight in the drops of water which make up falling rain. The sun is behind the observer, and its rays fall in a parallel direction upon the drops of rain before him. In each drop the light is dispersively refracted, and then reflected from the farther face of the drop; it travels back through the drop, and comes out with dispersing colours. According to the height of the sun, or the slope of its rays, a higher or lower rainbow will be formed. And, strange, no two people can see the very same bow; in fact the rainbow, as seen by the one eye, is not formed by the same water-drops as the rainbow seen by the other eye. When the primary bow is seen in most vivid colours on a dark cloud, a second arch, larger and fainter, is often seen. But the order of the colours is quite reversed. At a greater elevation, the sun's ray enters the lower side of a drop of rain-water, is refracted, reflected _twice_, and then refracted again before being sent out to the observer's eye. That is why the colours are reversed. _A one-coloured rainbow_ is a curious and rare phenomenon. It is a strange paradox, for the very idea of a rainbow brings up the seven colours--red, orange, yellow, green, blue, indigo, and violet. Yet Dr. Aitken tells us of a rainbow with one colour which he observed on Christmas Day, in 1888. He was taking his walk on the high ground south of Falkirk. In the east he observed a strange pillar-like cloud, lit up with the light of the setting sun. Then the red pillar extended, curved over, and formed a perfect arch across the north-eastern sky. When fully developed, this rainbow was the most extraordinary one which he had ever seen. There was no colour in it but red. It consisted simply of a red arch, and even the red had a sameness about it. Outside the rainbow there was part of a secondary bow. The Ochil Hills were north of his point of observation. These hills were covered with snow, and the setting sun was glowing with rosy light. Never had he seen such a depth of colour as was on them on this occasion. It was a deep, furnacy red. The sun's light was shorn of all the rays of short-wave length on its passage through the atmosphere, and only the red rays reached the earth. The reason why the Ochils glowed with so deep a red was owing to their being overhung by a dense curtain of clouds, which screened off the light of the sky. The illumination was thus principally that of the direct softer light of the sun. CHAPTER XXI THE AURORA BOREALIS He must be a very careless observer who has not been struck with the appearance of the streamers which occasionally light up the northern heavens, and which farmers consider to be indicators of strong wind or broken weather. The time was when the phenomenon was considered to be supernatural and portentous, as the chroniclers of spectral battles, when "fierce, fiery warriors fought upon the clouds, in ranks and squadrons, and right form of war." And even in the rural districts of Britain, the blood-coloured aurora, of October 24th, 1870, was considered to be the reflection of an enormous Prussian bonfire, fed by the beleaguered French capital. In joyful spirit, the Shetlanders call the beautiful natural phenomenon, "Merry Dancers." Burns associated their evanescence with the transitoriness of sensuous gratification:--"they flit ere you can point their place." And Tennyson spoke of his cousin's face lit up with the colour and light of love, "as I have seen the rosy red flushing in the northern night." Yet this phenomenon is to a great extent under the control of cosmical laws. One of the most difficult problems of our day has been to disentangle the irregular webwork of auroræ, and bring them under a law of periodicity, which depends upon the fluctuations of the sun's photosphere and the variations on the earth's magnetism, and which have such an important influence upon the fluctuations of the weather. The name "Aurora Borealis" was given to it by Gassendi in 1621. Afterwards, the old almanacs described it as the "Great Amazing Light in the North." In the Lowlands of Scotland, the name it long went by, of "Lord Derwentwater's Lights," was given because it suddenly appeared on the night before the execution of the rebel lord. In Ceylon auroræ were called "Buddha Lights." The first symptom of an aurora borealis is commonly a low arch of pale, greenish-yellow light, placed at right angles to the magnetic meridian. Sometimes rays cover the whole sky, frequently showing tremulous motion from end to end; and sometimes they appear to hang from the sky like the fringes of a mantle. They are among the most capricious of natural phenomena, so full of individualities and vagaries. To the glitter of rapid movement they add the charm of vivid colouring. It is strongly asserted that auroræ are preceded by the same general phenomena as thunder-storms. This was borne out by Piazzi Smith (late Astronomer-Royal for Scotland), who observed that their monthly frequency varies inversely with that of thunder-storms--both being safety-valves for the discharge of surplus electricity. Careful observers have, moreover, noticed a remarkable coincidence between the display of auroræ and the maxima of the sun's spots and of the earth's magnetic disturbances. Some have supposed that the light of the aurora is caused by clouds of meteoric dust, composed of iron, which is ignited by friction with the atmosphere. But there is this difficulty in the way, shooting stars are more frequent in the morning, while the reverse is the case with the aurora. The highest authorities have concluded, pretty uniformly, that auroræ are electric discharges through highly rarefied air, taking place in a magnetic field, and under the sway of the earth's magnetic induction. They are not inappropriately called "Polar lightnings," for when electricity misses the one channel it must traverse the other. The natives of the Arctic regions of North America pretend to foretell wind by the rapidity of the motions of the streamers. When they spread over the whole sky, in a uniform sheet of light, fine weather ensues. Fitzroy believed that auroræ in northern latitudes indicated and accompanied stormy weather at a distance. The same idea is still current among many farmers and fishermen in Scotland. Is there any audible accompaniment to the brilliant spectacle? The natives of some parts, with subtle hearing-power, speak of the "whizzing" sound which is often heard during auroral displays. Burns tells of their "hissing, eerie din," as echoes of the far-off songs of the Valkyries. Perhaps the most striking incident which corroborates this opinion occurred during the Franco-Prussian War. Rolier, a practised aëronaut, left Paris in a balloon, on his mission of city defence, and fourteen hours afterwards landed in Norway. He had reached the height of two and a half miles. When descending, he passed through a peculiar cloud of sulphurous odour, which emitted flashed light and a slight scratching or rustling noise. On landing, he witnessed a splendid aurora borealis. He must, therefore, have passed through a cloud in which an electrical discharge of an auroral nature was proceeding, accompanied with an audible sound. There is, moreover, no improbability of such sounds being occasionally heard, since a somewhat similar phenomenon accompanies the brush discharge of the electric machinery, to which the aurora bears considerable resemblance. Though no fixed conclusions are yet established about the causes of the brilliant auroral display, yet, as the results of laborious observations, we are assured that the stabler centre of our solar system holds in its powerful sway the several planets at their respective distances, supplying them all with their seasonable light and heat, vibrating sympathetic chords in all, and even controlling under certain--though to us still unknown--laws the electric streamers that flit, apparently lawlessly, in the distant earth's atmosphere. CHAPTER XXII THE BLUE SKY If we look at the sky overhead, when cloudless in the sunshine, we wonder what gives the air such a deep-blue colour. We are not looking, as children seem to do, into vacancy, away into the far unknown. And even, if that were the case, would not the space be quite colourless? What, then, produces the blueness? Some of the very fine dust-particles, even when clothed with an exceedingly thin coating of water-vapour, are carried very high; and, looking through a vast accumulation of these, we find the effect of a deep-blue colour. Why so? Because these particles are so small that they can only reflect the rays of the blue end of the spectrum; and the higher we ascend, the smaller are the particles and the deeper is the blue. But it is also because water, even in its very finest and purest form, is blue in colour. For long this was disputed. Even Sir Robert Christison concluded, after years of experimenting on Highland streams, that water was colourless. Of course, he admitted that the water in the Indian and Pacific Oceans has frequent patches of red, brown, or white colour, from the myriads of animalcules suspended in the water. Ehrenberg found that it was vegetable matter which gave to the Red Sea its characteristic name. But these, and similar waters, are not pure. It is to Dr. Aitken that the final discovery of the real colour of water is due. When on a visit to several towns on the shores of the Mediterranean, he set about making some very interesting experiments, which the reader will follow with pleasure. It is a well-known fact that colour transmitted through different bodies differs considerably from colour reflected by them. In his first experiment he took a long empty metal tube, open at one end, and closed at the other end by a clear-glass plate. This was let down vertically into the water, near to a fixed object, which appeared of most beautiful deep and delicate blue at a depth of 20 feet. Scientific men know that, if the colour of water is due to the light reflected by extremely small particles of matter suspended in the water, then the object looked at through it would have been illuminated with yellow (the complementary colour of blue). A blackened tube was then filled with water (which had a clear-glass plate fixed to the bottom), and white, red, yellow, and purple objects were sunk in the water, and these colours were found to change in the same way as if they were looked at through a piece of pale-blue glass. The white object appeared blue, the red darkened very rapidly as it sank, and soon lost its colour; at the depth of seven feet a very brilliant red was so darkened as to appear dark brick-red. The yellow object changed to green, and the purple to dark blue. But, still further to satisfy himself that water is really blue in itself, even without any particles suspended in it, he tested the colour of _distilled_ water. He filled a darkened tube with this water (clear-glass plates being at the ends of the tube), and looked through it at a white surface. The effect was the same as before, the colour was blue, almost exactly of the same hue as a solution of Prussian blue. This is corroborated by the fact that, the purer the water is in nature, the bluer is the tint when a large quantity is looked through. Some Highland lochs have crystal waters of the most extraordinary blue. Of course, some cling to the old idea that this is accounted for by the reflected blue of the clear heavens above. No doubt, if the sky be deep blue, then this blue light, when reflected by the surface of the water, will enrich and deepen the hue. But the water itself is _really_ blue. At the same time, the dust-particles suspended in the water have a great effect in making the water appear more beautiful, brilliant, and varied in its colouring; because little or no light is reflected by the interior of a mass of water itself. If a dark metal vessel be filled with a weak solution of Prussian blue, the liquid will appear quite dark and void of colour. But throw in some fine white powder, and the liquid will at once become of a brilliant blue colour. This accounts for the change of depth and brilliancy of colour in the several shores of the Mediterranean. When, then, you look at the face of a deep-blue lake on a summer evening--the heavens all aglow with the unrivalled display of colour from the zenith, stretching in lighter hues of glory to the horizon--though to you the calm water appears like a lake of molten metal glowing with sky-reflected light, so powerful and brilliant as entirely to overpower the light which is internally reflected, yet blue is the normal colour of the water: _blueness is its inherent hue_. Looking upwards, we observe three distinct kinds of blue in the sky from the horizon to the zenith. All painters in water-colours know that. Newton thought that the colour of the sky was produced in the same way as the colours in thin plates, the order of succession of the colours gradually increasing in intensity. CHAPTER XXIII A SANITARY DETECTIVE The impure state of the air in the rooms of a house can now be determined by means of colour alone. Dr. Aitken has invented a very simple instrument for that purpose; and this ought to be of great service to sanitary officers. It is called the koniscope--or dust-detective. The instrument consists of an air-pump and a metal tube with glass ends. Near one end of the test-tube is a passage by which it communicates with the air-pump, and near the other end is attached a stop-cock for admitting the air to be tested. It is not nearly so accurate as the dust-counter; but it is cheaper, more easily wrought, and more handy for quick work. All the grades of blue, from what is scarcely visible to deep, dark blue, may be attached alongside the tube on pieces of coloured glass; and opposite these colours are the numbers of dust-particles in the cubic inch of the similar air, as determined by the dust-counter. While the number of particles was counted by means of the dust-counter, the depth of blue given by the koniscope was noted; and the piece of glass of that exact depth of blue attached. A metal tube was fitted up vertically in the room, in such a way that it could be raised to any desired height into the impure air near the ceiling, so that supplies of air of different degrees of impurity might be obtained. To produce the impurity, the gas was lit and kept burning during the experiments. The air was drawn down through the pipe by means of the air-pump of the koniscope, and it passed through the measuring apparatus of the dust-counter on its way to the koniscope. It may be remarked that, by a stroke of the air-pump, the air within the test-tube is rarefied and the dust-particles seize the moisture in the super-saturated air to form fog-particles; through this fog the colour is observed, and the shade of colour determines the number of dust-particles in the air. These colours are named "just visible," "very pale blue," "pale blue," "fine blue," "deep blue," and "very deep blue." When making a sanitary inspection, the pure air should be examined first, and the colour corresponding to that should be considered as the normal health colour. Any increase from the depth would indicate that the air was being gradually contaminated; and the amount of increase in the depth of colour would indicate the amount of increase of pollution. As an illustration of what this instrument can detect, a room of 24 by 17 by 13 feet was selected. The air was examined before the gas was lighted, and the colour in the test-tube was very faint, indicating a clear atmosphere. In all parts of the room this was found the same. A small tube was attached to the test-tube, open at the other end, for taking air from different parts of the room. Three jets of gas were then lit in the centre of the room, and observations at once begun with the koniscope. Within thirty-five seconds of striking the match to light the gas, the products of combustion had extended near the ceiling to the end of the room; this was indicated by the colour in the koniscope suddenly becoming a deep blue. In four minutes the deep-blue-producing air was got at a distance of two feet from the ceiling. In ten minutes there was strong evidence of the pollution all through the room. In half-an-hour the impurity at nine feet from the floor was very great, the colour being an intensely deep blue. The wide range of the indications of the instrument, from pure clearness to nearly black blue, makes the estimate of the impurity very easily taken with it; and, as there are few parts to get out of order, it is hoped it may come into general use for sanitary work. CHAPTER XXIV FOG AND SMOKE Just two hundred and forty years ago, Mr. John Evelyn, F.R.S., a well-known writer on meteorology, sent a curious tract to King Charles II., which was ordered to be printed by his Majesty. It was entitled "Fumifugium," and dealt with the great smoke nuisance in London. I find from the thesis that he had a very hazy idea of the connection between fog and smoke; and no wonder, for it is only lately that the connection has been fully explained. We know that without dust-particles there can be no fog, and that smoke supplies a vast amount of such particles. Therefore, in certain states of the atmosphere, the more smoke the more fog. In Mr. Evelyn's day the fog, which he called "presumptuous smoake," was at times so dense that men could hardly discern each other for the "clowd." His Majesty's only sister had complained of the damage done to her lungs by the contamination, and Mr. Evelyn was disgusted at the apathy of the people to do anything to remedy the nuisance. He deplored that that glorious and ancient city of London should wrap her stately head in "clowds of smoake, so full of stink and darknesse." He was of opinion that a method of charring coal so as to divest it of its smoke, while leaving it serviceable for many purposes, should be made the object of a very strict inquiry. And he was right. For it is now known that fog in a town is intensified by much smoke. In a city like London or Glasgow, where a great river, fed by warm streams of water from gigantic works, passes through its centre, fogs can never be entirely obliterated, for the dust-particles in the air (often four millions and upwards in the cubic inch) will seize with terrible avidity the warm vapour rising from the river. That is the main reason why fogs cannot there be put down. Smoke is being consumed to a great extent; yet we find particles of sulphur remaining, which seize the warm vapour and form fogs dense enough to check all traffic. The worst form of city fogs seems to be produced when the air, after first flowing slowly in one direction, then turns on its tracks and flows back over the city, bringing with it a black pall, the accumulated products of previous days, to which gets added the smoke and other impurities produced at the time. What irritated Mr. Evelyn was that, outside of London, the air was clear when passengers could not walk in safety within the city. So vexed was he about the contamination, that he made it the occasion of all the "cathars, phthisicks, coughs, and consumption in the city." He appealed to common sense to testify that those who repair to London soon take some serious illness. "I know a man," he said, "who came up to London and took a great cold, which he could never afterwards claw off again." Mr. Evelyn proposed that, by an Act of Parliament, the nuisance be removed; enjoining that all breweries, dye-works, soap and salt boilers, lime-burners, and the like, be removed five or six miles distant from London below the river Thames. That would have materially helped his cause. But there is more difficulty in the purification than he anticipated. Yet there was pluck in the old man pointing out the killing contamination and suggesting a possible remedy. He had the fond idea that thereby a certain charm, "or innocent magick," would make a transformation scene like Arabia, which is therefore "styl'd the Happy, attracting all with its gums and precious spices." In purer air fogs would be less dense, breathing would be easier, business would be livelier, life would be happier. Few, I suppose, have laid their hands on this curious Latin thesis, or its quaint translation, directing the King's attention to the fogs that were ruining London. Since that time the city has increased, from little more than a village, to be the dwelling-place of six millions of human beings, yet too little improvement has been made in the removal of this fog nuisance. King Edward's drive through London would be even more dangerous on a muggy, frosty day than was Charles II.'s, when science was little known. CHAPTER XXV ELECTRICAL DEPOSITION OF SMOKE A good deal of scientific work is being done in the way of clearing away fog and smoke; and this, through time, may have some practical results in removing a great source of annoyance, illness, and danger in large towns. Sir Oliver Lodge and Dr. Aitken have been throwing light upon the deposition of smoke in the air by means of electricity. If an electric discharge be passed through a jar containing the smoke from burnt magnesium wire, tobacco, brown paper, and other substances, the dust will be deposited so as to make the air clear. Brush discharge, or anything that electrifies the air itself, is the most expeditious. If water be forced upwards through a vertical tube (with a nozzle one-twentieth of an inch in diameter), it will fall to the ground in a fine rain; but, if a piece of rubbed (electrified) sealing-wax be held a yard distant from the place where the jet breaks into drops, they at once fall in large spots as in a thunder-shower. If paper be put on the ground during the experiment, the sound of pattering will be observed to be quite different. If a kite be flown into a cloud, and made to give off electricity for some time, that cloud will begin to condense into rain. Experiments with Lord Kelvin's recorder show that variations in the electrical state of the atmosphere precede a change of weather. Then, with a very large voltaic battery, a tremendous quantity of electricity could be poured into the atmosphere, and its electrical condition could be certainly disturbed. If this could be made practically available, how useful it would be to farmers when the crops were suffering from excessive drought! It might be more powerfully available than the imagined condensation of a cloud into rain by the reverberation caused by the firing of a range of cannon. But what is the practical benefit of this information? If electricity deposits smoke, it might be made available in many ways. The fumes from chemical works might be condensed; and the air in large cities, otherwise polluted, might be purified and rendered innocuous. The smoke of chimneys in manufacturing works might be prevented from entering the atmosphere at all. In flour-mills and coal-mines the fine dust is dangerously explosive. In lead, copper, and arsenic works, it is both poisonous and valuable. Lead smelters labour under this difficulty of condensing the fume which escapes along with the smoke from red-lead smelting furnaces; and it was considered that an electrical process of condensation might be made serviceable for the purpose. At Bagillt, the method used for collecting or condensing the lead fume is a large flue two miles long; much is retained in this flue, but still a visible cloud of white-lead fume continually escapes from the top of the chimney. There is a difficulty in the way of depositing fumes in the flue by means of a sufficient discharge of electricity, viz. the violent draught which is liable to exist there, and which would mechanically blow away any deposited dust. But Dr. Aitken suggests that regenerators might be used along with the electricity. The warm fumes might be taken to a cold depositor, where (by the ordinary law of cold surfaces attracting warm dust-particles) the impurities would be removed, and, when purified, the air would again be taken through a hot regenerator before being sent up the chimney. By a succession of these chambers, with the assistance of electric currents, the air, impregnated with the most deleterious particles, or valuable dust, could be rendered innocuous. The sewage of our towns must be cleaned of its deleterious parts before being run into the streams which give drink to the lower animals, because an Act of Parliament enforces the process. Why, then, ought we not to have similar compulsion for making the smoke from chemical and other noxious works quite harmless before being thrown into the air which contains the oxygen necessary for the life of human beings? There seems to be a good field before electricians to catch the smoke on the wing and deposit its dust on a large scale. This seems to be a matter beyond our reach at present, except in the scientist's laboratory; but certainly it is a "consummation devoutly to be wished." CHAPTER XXVI RADIATION FROM SNOW One night a most interesting paper by Dr. Aitken, on "Radiation from Snow," was read by Professor Tait to the Fellows of the Royal Society of Edinburgh. I remember that Dr. Alex. Buchan--the greatest meteorologist living--spoke afterwards in the very highest terms of the subject-matter of the paper. This was corroborated by Lord Kelvin, Lord MacLaren, and Professor Chrystal. Dr. Aitken had been testing the radiating powers of different substances. Snow in the shade on a bright day at noon is 7° Fahr. colder than the air that floats upon it, whereas a black surface at the same is only 4° colder. This difference diminishes as the sun gets lower; and at night both radiate almost equally well. I select, among the careful and numerous observations, the notes on January 19, 1886; for I took note of the cold of that day in my diary. It was the coldest day of the whole of that winter. The barometer was 28·8 inches, and the thermometer 4°--that is, 28° of frost. According to Dr. Buchan, that January had only two equal in average cold for fifty years. On January 19, at 10 A.M., when the air was at 20° and the sky clear, a black surface registered 16° and the upper layer of snow 12°, showing a difference of 4° when both surfaces were colder than the superincumbent air. It is curious to note that, on February 5 of the same year, at the same hour, when the sky was overcast, the air was at 23°, the black surface registered 29°, and the snow 25°, showing again the difference of 4°; but, in this case, both surfaces were warmer than the air. In both cases the radiation at night was equal. This small absorbing power of snow for heat reflected and radiated from the sky during the day must have a most important effect on the temperature of the air. The temperature of lands when covered with snow must be much lower than when free from it. And, when once a country has become covered with snow, there will be a tendency towards glacial conditions. But, besides being a bad absorber of heat from the sky, snow is also a very poor conductor of heat. On that very cold night (January 18), when there was a depth of 5-1/2 inches of snow on the ground, and the night clear, with strong radiation, the temperature of the surface of the snow was 3° Fahr., and a minimum thermometer on the snow showed that it had been down to zero some time before. A thermometer, plunged into the snow down to the grass, gave the most remarkable register of 32°. Through the depth of 5-1/2 inches of snow there was a difference of temperature of 29°. This was confirmed by removing the snow, and finding that the grass was unfrozen. As the ground was frozen when the snow fell, it would appear that the earth's heat slowly thawed it under the protection of the snow. The protection afforded by the bad-conducting power of snow is of great importance in the economy of nature. How vegetation would suffer, were it exposed to a low temperature, unprotected by the snow-mantle! So that, though the continued snow cools the air for animals that can look after their own heating, it keeps warm the soil; and vegetation prospers under the genial covering. The fine rich look of the young wheat-blades, after a continued snow has melted, must strike the most careless observer. Instead of the half-blackened tips and semi-sickly blades, which we see in a field of young wheat after a considerable course of dry frost without snow, we have a rich, healthy green which shows the vital energy at work in the plants. Or even in the town gardens, after a continued snow has been melted away by a soft, western breeze, we are struck with the white, peeping buds of the snowdrop and the finely springing grass in the sward. Yet the snow-covering gives durability to cold weather. This has been demonstrated by Dr. Woeikof, the distinguished Russian meteorologist. On this account the spring months of Russia and Siberia are intensely cold. The plants, then, which in winter are unable by locomotion to keep themselves in health, are protected by the snow-mantle which chills the air for animals that can keep themselves in heat by exercise. What a grand compensating power is here! CHAPTER XXVII MOUNTAIN GIANTS Some mysterious physical phenomena can be clearly explained by the aid of science. The mountain giants that at times haunt the lonely valleys, and strike with fear the superstitious dwellers there, are only the enlarged shadows of living human beings cast upon a dense mist. The two most startling of these "eerie" phenomena are the spectres of Adam's Peak and the Brocken. The phenomena sometimes to be observed at Adam's Peak, in Ceylon, are very remarkable. Many travellers have given vivid accounts of these. On one occasion the Hon. Ralph Abercromby, in his praiseworthy enthusiasm for meteorological research, went there with two scientific friends to witness the strange appearance. The conical peak, a mile and a half high, overlooks a gorge west of it. When, then, the north-east monsoon blows the morning mist up the valley, light wreaths of condensed vapour pass to the right of the Peak, and catch the shadows at sunrise. This party reached the summit early one morning in February. The foreglow began to brighten the under-surface of the stratus-cloud with orange, and patches of white mist filled the hollows. Soon the sun peeped through a chink in the clouds, and they saw the pointed shadow of the Peak lying on the misty land. Then a prismatic circle, with the red inside, formed round the shadow. The meteorologist waved his arms about, and immediately he found giant shadowy arms moving in the centre of the rainbow. Soon they saw a brighter and sharper shadow of the Peak, encircled by a double bow, and their own spectral arms more clearly visible. The shadow, the double bow, and the giant forms, combined to make this phenomenon the most marked in the whole world. The question has been frequently asked: Why are such aërial effects not more widely observed? There are not many mountains of this height and of a conical shape; and still fewer can there be where a steady wind, for months together, blows up a valley so as to project the rising morning mist at a suitable height and distance on the western side, to catch the shadow of the peak at sunrise. The most famous place in Europe for witnessing the awe-inspiring phenomenon is the Brocken, in Germany--3740 feet in height. The only great disappointment there is that the conditions rarely combine at sunrise or sunset to have "the spectre" successful. In July 1892, my daughter and I were spending some weeks at Harzburg, and, of course, we had to visit the Brocken and take stock of the world-known phenomenon. At mid-day, the air at the flat summit was cold, clear, and hard. The boulders are of enormous size; and near the "Noah's Ark" Hotel and Observatory many are piled up in a mass, on which the observers stand at the appointed time for having their shadows projected on the misty air in the valleys. At five o'clock in the afternoon the sky was brilliantly clear on the summit of the Brocken; but the wind was rising from the sun's direction, and the mist was filling up the wide-spread eastern valley. We stood on the "spectre" boulders, and our shadows were thrown on the grass, just as at home. However, they fell upon large patches of white heather, which there is very plentiful. At six o'clock the sun was still shining beautifully, and we anxiously waited for the time when it would be low enough to raise our shadows to the misty wall. An hour afterwards, a hundred visitors were out, and many of us were on the "spectre" stones. There was great excitement in anticipation of the weird appearances, which had attracted us from such a distance. But, almost at the moment of success, the sun descended behind a belt of purple cloud, and all we saw was part of a rainbow on the misty hollow. For the sun never appeared again. This was intensely saddening, seeing that, but for that stratum of cloud above the horizon, the phenomenon would have been graphically displayed. The cold became suddenly intense, and we had to sleep with a freezing mist enveloping the hotel. In vain did we wait for the wakening call, to tell us of sunrise; for the sun could not pierce the mist, and we had to return home disappointed. Sometimes the rainbow colours assume the shapes of crosses instead of circles. Occasionally a bright halo will be seen above the shadow-head of the observer, concentric rainbows enclosing all. In some recorded cases the grand effect must have been simply glorious. Scientific observation has done much to dispel the superstition which has clung so tenaciously to the Highland mind. The lonely grandeur of the weird mountain giants has been clearly explained as perfectly natural, yet the awe-striking feeling cannot be entirely driven off. CHAPTER XXVIII THE WIND Once was the remark pointedly made: "The wind bloweth where it listeth." And that is nearly true still. The leading winds are under the calculation of the meteorologist, but the others will not be bound by laws. Yet there are instruments for measuring the velocity and force of the wind, after it is on; but "whence it comes" is a different matter. A gentle air moves at the rate of 7 miles an hour; a hurricane from 80 to 150 miles, pressing with 50 lbs. on the square foot exposed to its fury. Some of the gusts of the Tay Bridge storm, in 1879, had a velocity of 150 miles an hour, with a pressure of 80 to 90 lbs. to the square foot. Before steamers supplanted so many sailing vessels, seamen required to be always on the alert as to the direction and strength of the wind, and the likelihood of any sudden change; and they chronicled twelve different strengths from "faint air" to a "storm." In general, the wind may be considered to be the result of a change of pressure and temperature in the atmosphere at the same level. The air of a warmer region, being lighter, ascends, and gives place to a current of wind from a colder region. These two currents--the higher and the lower--will continue to blow until there is equilibrium. The trade winds are regular and constant. These were much followed in the days of old. A vast amount of air in the tropics gets heated and ascends, being lighter, and travels to the colder north. A strong current rushes in from the north to take its place. But the earth rotates round its axis from west to east, and the combined motions make two slant wind directions, which are called the "trade winds," because they were so important in trade navigation. Among the periodical winds are the "land and sea breezes." During the day, the land on the sea coast is warmer than the sea; accordingly, the air over the land becomes heated and ascends, the fine cool breeze from the sea taking its place. Towards evening there is the equilibrium of temperature which produces a temporary calm. Soon the earth chills, and the sea is counterbalancingly warm--as sea-water is steadier as to temperature than is land--the air over the sea becomes warmer, and ascends, the current from the land rushing in to take its place. Hence during the night the wind is reversed, until in the morning again the equilibrium is restored and there is a calm, so far as these are concerned. These are therefore called the "land and sea breezes." Of course, it is within the tropics that these breezes are most marked. By the assistance of other winds, a hurricane will there occasionally destroy towns and bring about much damage and loss of life; but better that hundreds should perish by a hurricane than thousands by the pestilence which, but for the storm, would have done its dire work. In countries where the differences of pressure are more marked than the differences of temperature, in the surrounding regions the strength of the wind thereby occasioned is far stronger than the land and sea breezes. The variable winds are more conflicting. These depend on purely local causes for a time, such as "the nature of the ground, covered with vegetation or bare; the physical configuration of the surface, level or mountainous; the vicinity of the sea or lakes, and the passage of storms." Among these winds are the simoom and sirocco. The _east_ winds, which one does not care about in the British Islands during the spring time, are occasioned by the powerful northern current which rushes south from the northern regions in Europe. Dr. Buchan points out a very common mistake among even intelligent observers who shudder at the hard east winds. It is generally held that these winds are damp. They are unhealthy, but they are dry. It is quite true that many easterly winds are peculiarly moist; all that precede storms are so far damp and rainy; and it is owing to this circumstance that, on the east coast of Scotland, the east winds are searching and carry most of the annual rainfall there. But all of these moist easterly winds, however, soon turn to some westerly point. The real east wind, so much feared by invalids, does not turn to the west; it is exceeding dry. Curious is it that brain diseases, as well as consumption, reach their height in Britain while east winds prevail. Once in Edinburgh, during the early spring, I had rheumatic fever, and during my convalescence my medical adviser, Dr. Menzies, would not let me have a short drive until the wind changed to the west. The first thing I anxiously watched in the morning was the flag on the Castle; and for nearly two months it always waved from the east. How heart-depressing! Creatures are we in the hands of nature's messengers. We so much depend upon the weather for our happiness. Joyful are we when the honey-laden zephyr waves the long grass in June, or when "The gentle wind, a sweet and passionate wooer, Kisses the blushing leaf." Compared with this, how terrible is Shakespeare's allusion to the appalling aspects of the storm:-- "I have seen tempests, when the scolding winds Have rived the knotty oaks; and I have seen The ambitious ocean swell, and rage and foam, To be exalted with the threat'ning clouds; But never till to-night, never till now, Did I go through a tempest dropping fire." CHAPTER XXIX CYCLONES AND ANTI-CYCLONES The criticism of the weather in the meteorological column of our daily newspapers invariably speaks of "cyclones." It is, therefore, advisable to give as plain an explanation of these as possible. Cyclones are "storm-winds." Their nature has to be carefully studied by meteorologists, who are industriously at work to ascertain some scientific basis for the atmospheric movements. What is the cause of the spiral movement in storm-winds? In their centre the depression of the barometer is lowest, because the atmosphere there is lightest. As the walls of the spiral are approached, the barometer rises. Dr. Aitken has ingeniously hit upon an experiment to illustrate a spiral in air. All that is necessary is a good fire, a free-going chimney, and a wet cloth. The cloth is hung up in front of the fire, and pretty near it, so that steam rises readily from its surface; and, when there are no air-currents in the room, the steam will rise vertically, keeping close to the cloth. But if the room has a window in the wall, at right angles to the fireplace, so as to cause the air coming from it to make a cross-current past the fire, then a cyclone will be formed, and the vapour from the cloth will be seen circling round. When the cyclone is well formed, all the vapour is collected into the centre of the cyclone, and forms a white pillar extending from the cloth to the chimney. This experiment shows that no cyclone can form without some tangential motion in the air entering the area of low-pressure. Now to illustrate the spiral approach. Fill with water a cylindrical glass vessel, say 15 inches in diameter and 6 inches deep. Have an orifice with a plug a little from the centre of the bottom. Remove the plug, the water runs out, passing round the vessel in a vortex form. But, as the passage between the orifice (or centre of the cyclone) and the temporary division is narrower than in any other place, the water has to pass this part much more quickly than at any other place. And this curious result is observed: the top of the cyclone no longer remains over the orifice, but _travels_ in the direction of the water which is moving most speedily. Similar to this is the cyclone in the atmosphere; its centre also moves in the direction of the quickest flowing wind that enters it. Dr. Aitken is of opinion that, in forecasting storms, too little attention has been paid to the _anti-cyclones_. They do more than simply follow and fill up the depression made by the cyclones. They initiate and keep up their own circulation, and collect the materials with which the cyclones produce their effect. Neither could work efficiently without the other. Suppose a large area on the earth over which the air is still in bright sunshine. After a time, when the air gets heated and charged with vapour, columns of air would begin to ascend in a disorderly fashion. But suppose an anti-cyclone is blowing at one side of this area. When the upper air descends to the earth, it spreads outwards in all directions; but the earth's rotation interferes and changes the radial into a spiral motion. The anti-cyclonic winds will prevent the formation of local cyclones, and drive all the moist, hot air to its circumference, just above the earth. The anti-cyclone forces its air tangentially into the cyclone, and gives it its direction and velocity of rotation, also the direction and rate of travel of the centre of depression. The earth's rotation is the original source of the rotatory movements, but both intensify the initial motion. Accordingly, the cyclone must travel in the direction of the strongest winds blowing into it, just as the vortex in the vessel with the eccentric orifice travelled in the direction of the quickest moving water. This is verified by a study of the synoptic charts of the Meteorological Office. The sun's heat has always been looked upon as the main source of the energy of our winds, but some account must also be taken of the effects of cold. It is well known that the mean pressure over Continental areas is high during winter and low during summer. As the sun's rays during summer give rise to the cyclonic conditions, so the cooling of the earth during winter gives rise to anti-cyclonic conditions. It is found during the winter months in several parts of the Continent that as the temperature falls the pressure rises, producing anti-cyclones over the cold area; whereas, when the temperature begins to rise, the pressure falls, and cyclones are attracted to the warming area. Small natural cyclones are often seen on dusty roads, the whirling column having a core of dusty air, and the centre of the vortex travelling along the road, tossing up the dust in a very disagreeable way to pedestrians. Sometimes such a cyclone will toss up dry leaves to a height of four or five feet. They are very common; but it is only when dust, leaves, or other light material is present that they are visible to the eye. CHAPTER XXX RAIN PHENOMENA The soft rain on a genial evening, or the heavy thunder-showers on a broiling day, are too well known to be written about. Sometimes rain is earnestly wished for, at other times it is dreaded, according to the season, seed-time or harvest. Some years, like 1826, are very deficient in rainfall, when the corn is stunted and everything is being burnt up; other years, like 1903, there is an over-supply, causing great damage to agriculture. The year 1903 will long be remembered for its continuous rainfall; it is the record year; no year comes near it for the total rainfall all over the kingdom. Rain is caused by anything that lowers the temperature of the air below the dew-point, but especially by winds. When a wind has blown over a considerable area of ocean on to the land, there is a likelihood of rain. When this wind is carried on to higher latitudes, or colder parts, there is a certainty of rain. Of course, in the latter case the rain will fall heavier on the wind side than on the lee side. For short periods, the heaviest falls or "plouts" of rain are during thunder-storms. When the raindrops fall through a broad, cold stratum of air, they are frozen into hail, the particles of which sometimes reach a large size, like stones. Of course, water-spouts now and again are of terrible violence. One of the heaviest rainfalls yet recorded in Great Britain was about 2-1/4 inches in forty minutes at Lednathie, Forfarshire, in 1887. Now 1 inch deep of rain means 100 tons on an imperial acre; so the amount of water falling on a field during that short time is simply startling. The heaviest fall for one day was at Ben Nevis Observatory, being fully 7-1/4 inches in 1890. In other parts of the world this is far exceeded. In one day at Brownsville, Texas, nearly 13 inches fell in 1886. On the Khasi hills, India, 30 inches on each of five successive days were registered. At Gibraltar, 33 inches were recorded in twenty-six hours. The heaviest rainfalls of the globe are occasioned by the winds that have swept over the most extensive ocean-areas in the tropics. On the summer winds the rainfall of India mainly depends; when this fails, there is most distressing drought. Reservoirs are being erected to meet emergencies. From Dr. Buchan's statistics it is found that the annual rainfall at Mahabaleshwar is 263 inches; at Sandoway 214; and at Cherra-pungi 472 inches, the largest known rainfall anywhere on the globe. Over a large part of the Highlands of Scotland more than 80 inches fall annually, while in some of the best agricultural districts there it does not exceed 30 inches. Of all meteorological phenomena, rainfall is the most variable and uncertain. Symons gives as tentative results from twenty years' observations in London--(1) In winter, the nights are wetter than the days; (2) in spring and autumn, there is not much difference; (3) in summer, nearly half as much again by day as by night. The wearisomeness of statistics may be here relieved by a short consideration of the _splash_ of a drop of rain. Watching the drop-splashes on a rainy day in the outskirts of the city, when unable to get out, I brought to my recollection the marvellous series of experiments made by Professor A. M. Worthington in connection with these phenomena. Of course, I could not see to proper advantage the formation of the splashes, as the heavy raindrops fell into these tiny lakes on the quiet road. There is not the effect of the huge thunder-drops in a stream or pool. The building up of the bubbles is not here perfect, for the domes fail to close, nor are the emergent columns visible to the naked eye. It is a pity; for R. L. Stevenson once wrote of them in his delightful "Inland Voyage," when he canoed in the Belgian canals, as thrown up by the rain into "an infinity of little crystal fountains." Beautiful is this effect if one is under shelter, every dome seeming quite different in contour and individuality from all the rest. But terrible is it when out fishing on Loch Earn, even with the good-humoured old Admiral, when the heavy thunder-drops splash up the crystal water, and one gets soaked to the skin, sportsman-like despising an umbrella. There is, however, a scientific interest about the splash of a drop. The phenomenon can be best seen indoors by letting a drop of ink fall upon the surface of pure water in a tumbler, which stands on white paper. It is an exquisitely regulated phenomenon, which very ideally illustrates some of the fundamental properties of fluids. When a drop of milk is let fall upon water coloured with aniline dye, the centre column of the splash is nearly cylindrical, and breaks up into drops before or during its subsequent descent into the liquid. As it disappears below the surface, the outward and downward flow causes a hollow to be again formed, up the sides of which a ring of milk is carried; while the remainder descends to be torn a second time into a beautiful vortex ring. This shell or dome is a characteristic of all splashes made by large drops falling from a considerable height, and is extremely pretty. Sometimes the dome closes permanently over the imprisoned air, and forms a large bubble floating upon the water. The most successful experiments, however, have been carried through by means of instantaneous photography, with the aid of a Leyden-jar spark, whose duration was less than the ten-millionth of a second. But the simple experiments, without the use of the apparatus, will while away a few hours on a rainy afternoon, when condemned to the penance of keeping within doors. CHAPTER XXXI THE METEOROLOGY OF BEN NEVIS Several large and very important volumes of the Royal Society of Edinburgh are devoted to statistics connected with the meteorology of Ben Nevis. Most of the abstracts have been arranged by Dr. Buchan; while Messrs. Buchanan, Omond, and Rankine have taken a fair share of the work. This Observatory, as Mr. Buchanan remarks, is unique, for it is established in the clouds; and the observations made in it furnish a record of the meteorology of the clouds. It is 4406 feet above the level of the sea; and as there is a corresponding Observatory at Fort William, at the base of the mountain, it is peculiarly well fitted for important observations and weather forecasting. The mountain, too, is on the west sea-coast of Scotland, exposed immediately to the winds from the Atlantic, catching them at first hand. It is lamentable to think that, when the importance of the observations made at the two Observatories was becoming world known, funds could not be got to carry them on. Ben Nevis is the highest mountain in the British Islands, best fitted for meteorological observations; yet these have been stopped for want of money. Dr. Buchan's valuable papers were published before any one dreamed of the stoppage of the work, which had such an important bearing on men engaged in business or taken up with open-air sport. From these I shall sift out a few facts that even "mute, inglorious" meteorologists may be interested in knowing. For a considerable time the importance of the study of the changes of the weather has come gradually to be recognised, and an additional impetus was given to the prosecution of this branch of meteorology when it was seen that the subject had intimate relations to the practical question of weather forecasts, including storm warnings. Weather maps, showing the state of the weather over an extensive part of the surface of the globe, began to be constructed; but these were only indicators from places at the level of the sea. The singular advantages of a high-level observatory occurred to Mr. Milne Home in 1877; and Ben Nevis was considered to be in every respect the most suitable in this country. The Meteorological Council of the Royal Society of London offered in 1880, unsolicited, £100 annually to the Scottish Meteorological Society, to aid in the support of an Observatory, the only stipulation being that the Council be supplied with copies of the observations. From June to October, in 1881, Mr. Wragge made daily observations at the top of the Ben; and simultaneous observations were made, by Mrs. Wragge, at Fort William. A second series, on a much more extended scale, was made in the following summer. Funds were secured to build an Observatory; and, in November 1883, the regular work commenced, consisting of hourly observations by night as well as by day. Until a short time ago, these were carried on uninterruptedly. Telegraphic communications of each day's observations were sent to the morning newspapers; and now we are disappointed at not seeing them for comparison. The whole of the observations of temperature and humidity were of necessity eye-observations. For self-registering thermometers were comparatively useless when the wind was sometimes blowing at the rate of 100 miles an hour. Saturation was so complete in the atmosphere that everything exposed to it was dripping wet. Every object exposed to the outside frosts of winter soon became thickly incrusted with ice. Snowdrifts blocked up exposed instruments. Accordingly, the observers had to use their own eyes, often at great risks. The instruments in the Ben Nevis Observatory, and in the Observing Station at Fort William, were of the best description. Both stations were in positions where the effects of solar and terrestrial radiation were minimised. No other pair of meteorological stations anywhere in the world are so favourably situated as these two stations, for supplying the necessary observations for investigating the vertical changes of the atmosphere. It is to be earnestly hoped, therefore, that funds will be secured to resume the valuable work. The rate of the decrease of temperature with height there is 1° Fahr. for every 275 feet of ascent, on the mean of the year. The rate is most rapid in April and May, when it is 1° for each 247 feet; and least rapid in November and December, when it is 1° for 307 feet. This rate agrees closely with the results of the most carefully conducted balloon ascents. The departures from the normal differences of temperature, but more especially the inversions of temperature, and the extraordinarily rapid rates of diminution with height, are intimately connected with the cyclones and anti-cyclones of North-Western Europe; and form data, as valuable as they are unique, in forecasting storms. The most striking feature of the climate of Ben Nevis is the repeated occurrence of excessive droughts. For instance, in the summer and early autumn of 1885, low humidities and dew-points frequently occurred. Corresponding notes were observed at sea-level. During nights when temperature falls through the effects of terrestrial radiation, those parts of the country suffer most from frosts over which very dry states of the air pass or rest; whereas, those districts, over which a more humid atmosphere hangs, will escape. On the night of August 31 of that year, the potato crop on Speyside was totally destroyed by the frost; whereas at Dalnaspidal, in the district immediately adjoining, potatoes were scarcely--if at all--blackened. The mean annual pressure at Ben Nevis was 25·3 inches, and at Fort William 29·8, the difference being 4-1/2 inches for the 4400 feet. For the whole year, the difference between the mean coldest hour, 5 A.M., and the warmest hour, 2 P.M., is 2°. For the five months, from October to February, the mean daily range of temperature varied only from O·6 to 1·5. This is the time of the year when storms are most frequent; and this small range in the diurnal march of the temperature is an important feature in the climatology of Ben Nevis; for it presents, in nearly their simple form, the great changes of temperature accompanying storms and other weather changes, which it is so essential to know in forecasting weather. The daily maximum velocity of the wind occurs during the night, the daily differences being greatest in summer and least in winter. A blazing sun in the summer daily pours its rays on the atmosphere, and a thick envelope of cloud has apparently but little influence on the effect of the sun's rays. Thunder-storms are essentially autumn and winter phenomena, being rare in summer. According to Mr. Buchanan, the weather on Ben Nevis is characterised by great prevalence of fog or mist. In continuously clear weather it practically never rains on the mountain at all. In continuously foggy weather, on the other hand, the average daily rainfall is 1 inch. There is a large and continuous excess of pressure in clear weather over that of foggy weather. The mean temperature of the year is 3-1/2 degrees higher in clear than in foggy weather. In June the excess is 10 degrees. The nocturnal heating in the winter is very clearly observed. This has been noticed before in balloons as well as on mountains. The fog and mist in winter are much denser than in summer. Whether wet or dry, the fog which characterises the climate of the mountain is nothing but _cloud_ under another name. CHAPTER XXXII THE WEATHER AND INFLUENZA Some remarkable facts have been deduced by the late Dr. L. Gillespie, Medical Registrar, from the records of the Royal Infirmary of Edinburgh. He considered that it might lead to interesting results if the admissions into the medical wards were contrasted with the varying states of the atmosphere. The repeated attacks of influenza made him pay particular attention to the influence of the weather on that disease. The meteorological facts taken comprise the weekly type of weather, _i.e._ cyclonic or anti-cyclonic, the extremes of temperature for the district for each week, and the mean weekly rainfall for the same district. More use is made of the extremes than of the mean, for rapid changes of temperature have a greater influence on disease than the actual mean. The period which he took up comprises the seven years 1888-1895. There was a yearly average of admissions of 3938; so that he had a good field for observation. Six distinct epidemics of influenza, varying in intensity, occurred during that period; yet there had been only twenty-three attacks between 1510 and 1890. Accordingly, these six epidemics must have had a great influence on the incidence of disease in the same period, knowing the vigorous action of the poison on the respiratory, the circulatory, and the nervous systems. The epidemics of influenza recorded in this country have usually occurred during the winter months. The first epidemic, which began on the 15th of December 1889 and continued for nine weeks, was preceded by six weeks of cyclonic weather, which was not, however, accompanied by a heavy rainfall. Throughout the course of the disease, the type continued to be almost exclusively cyclonic, with a heavy rainfall, a high temperature, and a great deficiency of sunshine. The four weeks immediately following were also chiefly cyclonic, but with a smaller rainfall. The summer epidemic of 1891 followed a fine winter and spring, during which anti-cyclonic conditions were largely prevalent. But the epidemic was immediately preceded by wet weather and a low barometer. It took place in dry weather, and was followed by wet, cyclonic weather in turn. The great winter epidemic of 1891 followed an extremely wet and broken autumn. Simultaneously with the establishment of an anti-cyclone, with east wind, practically no rain, and a lowering temperature, the influenza commenced. Great extremes in the temperature followed, the advent of warmer weather and more equable days witnessing the disappearance of the disease. The fourth epidemic was preceded by a wet period, ushered in by dry weather, accompanied by great heat; and its close occurred in slightly wetter weather, but under anti-cyclonic conditions. The fifth outbreak began after a short anti-cyclone had become established over our islands, continued during a long spell of cyclonic weather with a considerable rainfall, but was drowned out by heavy rains. The last appearance of the modern plague, of which Dr. Gillespie's paper treats, commenced after cold and wet weather, continued in very cold but drier weather, and subsided in warmth with a moderate rainfall. The conditions of these six epidemics were very variable in some respects, and regular in others. The most constant condition was the decreased rainfall at the time, when the disease was becoming epidemic. Anti-cyclonic weather prevailed at the time. According to Dr. Gillespie, the tables seem to suggest that a type of weather, which is liable to cause catarrhs and other affections of the respiratory tract, precedes the attacks of influenza; but that the occurrence of influenza in _epidemic form_ does not appear to take place until another and drier type has been established. As the weather changes, the affected patients increase with a rush. He is of opinion that the supposed rapid spread of influenza on the establishment of anti-cyclonic conditions may be explained in this way. The air in the cyclonic vortex, drawn chiefly from the atmosphere over the ocean, is moist, and contains none of the contagion; the air of the anti-cyclone, derived from the higher strata, and thus from distant cyclones, descending, blows gently over the land to the nearest cyclone, and, being drier, is more able to carry suspended particles with it. He considers that temperature has nothing to do with the problem, except in so far as the different types of weather may modify it. The Infirmary records point to the occurrence of similar phenomena, recorded on previous occasions. Accordingly, if such meteorological conditions are not indispensable to the spread of influenza in epidemic form, they at least afford favourable facilities for it. CHAPTER XXXIII CLIMATE One is not far up in years, in Scotland at any rate, without practically realising what climate means. He may not be able to put it in words, but easterly haars, chilling rimes, drizzling mists, dagging fogs, and soddening rains speak eloquently to him of the meaning of climate. Climate is an expression for the conditions of a district with regard to temperature, and its influence on the health of animals and plants. The sun is the great source of heat, and when its rays are nearly perpendicular--as at the Tropics--the heat is greater on the earth than when the slanted rays are gradually cooled in their passage. As one passes to a higher level, he feels the air colder, until he reaches the fluctuating snow-line that marks perpetual snow. The temperature of the atmosphere also depends upon the radiation from the earth. Heat is quite differently radiated from a long stretch of sand, a dense forest, and a wide breadth of water. Strange is it that a newly ploughed field absorbs and radiates more heat than an open lea. The equable temperature of the sea-water has an influence on coast towns. The Gulf Stream, from the Gulf of Mexico, heats the ocean on to the west coast of Britain, and mellows the climate there. The rainfall of a district has a telling effect on the climate. Boggy land produces a deleterious climate, if not malaria. Over the world, generally, the prevailing winds are grand regulators of the climate in the distinctive districts. A wooded valley--like the greatest in Britain, Strathmore--has a health-invigorating power: what a calamity it is, then, that so many extensive woods, destroyed by the awful hurricane twelve years ago, are not replanted! Some people can stand with impunity any climate; their "leather lungs" cannot be touched by extremes of temperature; but ordinary mortals are mere puppets in the hands of the goddess climate. Hence health-resorts are munificently got up, and splendidly patronised by people of means. The poor, fortunately, have been successful in the struggle for existence, by innate hardiness, otherwise they would have had a bad chance without ready cash for purchasing health. It may look ludicrous at first sight, but it seems none the less true, that the variation of the spots on the sun have something to do with climate, even to the produce of the fields. On close examination, with a proper instrument, the disc of the sun is found to be here and there studded with dark spots. These vary in size and position day after day. They always make their first appearance on the same side of the sun, they travel across it in about fourteen days, and then they disappear on the other side. There is a great difference in the number of spots visible from time to time; indeed, there is what is called the minimum period, when none are seen for weeks together, and a maximum period, when more are seen than at any other time. The interval between two maximum periods of sun-spots is about eleven years. This is a very important fact, which has wonderful coincidences in the varied economy of nature. Kirchhoff has shown, by means of the spectroscope, that the temperature of a sun-spot must be lower than that of the remainder of the solar surface. As we must get less heat from the sun when it is covered with spots than when there are none, it may be considered a variable star, with a period of eleven years. Balfour Stewart and Lockyer have shown that this period is in some way connected with the action of the planets on the photosphere. As we have already mentioned, the variations of the magnetic needle have a period of the same length, its greatest variations occurring when there are most sun-spots. Auroræ, and the currents of electricity which traverse the earth's surface, follow the same law. This remarkable coincidence set men a-thinking. Can the varying condition of the sun exert any influences upon terrestrial affairs? Is it connected with the variation of rainfall, the temperature and pressure of the atmosphere, and the frequency of storms? Has the regular periodicity of eleven years in the sun-spots no effect upon climate and agricultural produce? Mr. F. Chambers, of Bombay, has taken great trouble to strike, as far as possible, a connection between the recurring eleven years of sun-spots and the variation of grain prices. He arranged the years from 1783 to 1882 in nine groups of eleven years; and, from an examination of his tables, we find that there is a decided tendency for high prices to recur at more or less regular intervals of about eleven years, and a similar tendency for low prices. An occasional slight difference can be accounted for by some abnormal cause, as war or famine. Amid all the apparently irregular fluctuations of the yearly prices, there is in every one of the ten provinces of India a periodical rise and fall of prices once every eleven years, corresponding to the regular variation which takes place in the number of sun-spots during the same period. If it were possible to obtain statistics to show the actual out-turn of the crops each year, the eleven yearly variations calculated therefrom might reasonably correspond with the sun-spot variations even more closely than do the price variations. This is a remarkable coincidence, if nothing more. What if it were yet possible to predict the variations of prices in the coming sun-spot cycle? Such a power would be of immense service. By its aid it could be predicted that, as the present period of low prices has followed the last maximum of sun-spots, which was in the year 1904, it will not last much longer, but that prices must gradually keep rising for the next five years. Could science really predict this, it would be studied by many and blessed by more. Yet the strange coincidence of a century's observations renders the conclusions not only possible, but to some extent probable. CHAPTER XXXIV THE "CHALLENGER" WEATHER REPORTS The _Challenger_ Expedition, commenced by Sir Wyville Thomson, and after his death continued by Sir John Murray, with an able staff of assistants for the several departments, was one of the splendid exceptions to the ordinary British Government stinginess in the furtherance of science. The results of the Expedition were printed in a great number of very handsome volumes at the expense of the Government. And the valuable deductions from the _Challenger's_ Weather Reports by Dr. Alex. Buchan, in his "Atmospheric Circulation," have thrown considerable light upon oceanic weather phenomena. For some of his matured opinions on these, I am here much indebted to him. Humboldt, in 1817, published a treatise on "Isothermal Lines," which initiated a fresh line for the study of atmospheric phenomena. An isotherm is an imaginary line on the earth's surface, passing through places having a corresponding temperature either throughout the year or at any particular period. An isobar is an imaginary line on the earth's surface, connecting places at which the mean height of the barometer at sea-level is the same. To isobars, as well as to isotherms, Dr. Buchan has devoted considerable attention. In 1868, he published an important series of charts containing these, with arrows for prevailing winds over the earth for the months of the year. In this way what are called synoptic charts were established. In the _Challenger_ Report are shown the various movements of the atmosphere, with their corresponding causes. It is thus observed that the prevailing winds are produced by the inequality of the mass of air at different places. The air flows from a region of higher to a region of lower pressure, _i.e._ from where there is an excessive mass of air to fill up some deficiency. And this is the great principle on which the science of meteorology rests, not only as to winds, but as to weather changes. Of the sun's rays which reach the earth, those that fall on the land are absorbed by the surface layer of about 4 feet in thickness. But those that fall on the surface of the ocean penetrate, as shown by the observations of the _Challenger_ Expedition, to a depth of about 500 feet. Hence, in deep waters the temperature of the surface is only partially heated by the direct rays of the sun. In mid-ocean the temperature of the surface scarcely differs 1° Fahr. during the whole day, while the daily variation of the surface layer of land is sometimes 50°. The temperature of the air over the ocean is about three times greater than that of the surface of the open sea over which it lies; but, near land, this increases to five times. The elastic force of vapour is seen in its simplest form on the open sea, as disclosed by these Reports. It is lowest at 4 A.M. and highest at 2 P.M. The relative humidity is just the reverse. When the temperature is highest, the saturation of the air is lowest, and _vice versâ_. So on land when the air, by radiation of heat from the earth, is cooled below the dew-point, dew is produced, and, at the freezing-point, hoar-frost. The _Challenger_ Reports, too, show that the force of the winds on the open sea is subject to no distinct and uniform daily variation, but that on nearing land the force of the wind gives a curve as distinctly marked as the ordinary curve of temperature. That force is lowest from 2 to 4 A.M., and highest from 2 to 4 P.M. Each of the five great oceans gives the same result. At Ben Nevis, on the other hand, these forces are just reversed in strength. It is also shown by the _Challenger_ observations that on the open sea the greatest number of thunder-storms occur from 10 P.M. to 8 A.M. And, from this, Dr. Buchan concludes that over the ocean terrestrial radiation is more powerful than solar radiation in causing those vertical disturbances in the equilibrium of the atmosphere which give rise to the thunder-storm. CHAPTER XXXV WEATHER-FORECASTING To foretell with any degree of certainty the state of the weather for twenty-four hours is of immense advantage to business men, tourists, fishermen, and many others. The weather is everybody's business. And the probabilities of accurate forecasts are so improving that all are more or less giving attention to the morning meteorological reports. Weather-forecasting depends on the principle from vast experience that, if one event happens, a second is likely to follow. According to the extent and accuracy of the data, will be the strength of the probability of correct forecasts. And the great end of popular meteorology is to demonstrate this. We have given some explanations of the weather in some respects unique; and a careful consideration of these explanations will the more convince the reader of the importance of the subject. No doubt the changes of the weather are extremely complex, at times baffling; and the wonder is that forecasts come so near the truth. For instance, the year 1903 almost defied the ordinary rules of weather, for it broke the record for rainfall. And, last year, so repulsive and unseasonable was the spring, that there seemed to be a virtual "withdrawal" of the season. I wrote on it as "The Recession of Spring." Speak about Borrowing Days! We had the equinoctial gales of March about the middle of April. On very few days had we "clear shining to cheer us after rain," for the bitter cold dried up any genial moisture. An old farmer remarked that "We're gaun ower faur North." No one could account for the backwardness of the season. Unless for the cheering songs of the grove-charmers, one would have forgotten the time of the year. In March of this year, at Strathmore, the barometer fell from 30·5 inches (the highest for years) to 28·65 in five days without unfavourable weather following. It again rose to 30·05, then fell to 28·45, followed by a rise to 28·7 without any peculiar change. But in two days it fell to 28·4 (the lowest for years), followed by a deluge of rain and a perfect hurricane for several hours, while the temperature was fortunately mild. It was only evident at the end that this universal storm had been "brewing" some days before. All are familiar with the ordinary prognostics of good and bad weather. A "broch" round the moon, in her troubled heaven, indicates a storm of rain or wind. When the dark crimson sun in the evening throws a brilliant bronzed light on the gables and dead leaves, we are sure that there is an intense radiation from the earth to form dew, or even hoar-frost. According to the meteorological folk-lore, the weather of the summer season is indicated by the foliation of the oak and ash trees. If the oak comes first into leaf, the summer will be hot and dry, if the ash has the precedence it will be wet and cold. Looking over the observations of the budding of these two trees for half a century, I find that the weather-lore adage has been pretty correct. The ash was out before the oak a full month in the years 1816, '17, '21, '23, '28, '29, '30, '38, '40, '45, '50, and '59; and the summer and autumn in these years were unfavourable. Again, the oak was out before the ash several weeks in the years 1818, '19, '20, '22, '24, '25, '26, '27, '33, '34, '35, '36, '37, '42, '46, '54, '68, and '69; the summers during these years were dry and warm, and the harvests were abundant. One can never think of this weather prognostic from nature without recalling the Swallow Song of Tennyson's "Princess":-- "Why lingereth she to clothe her heart with love, Delaying, as the tender ash delays To clothe herself, when all the woods are green?" On a muggy morning a sudden clearness in the south "drowns the ploughman." And yet enough blue in the sky "tae mak' a pair o' breeks" cheers one with the assurance of coming dry and sunny weather. The low flying of the swallows betokens rain, as well as any unseasonable dancing of midges in the evening. Sore corns on the feet, and rheumatism in the joints, are direful precursors. The leaves are all a-tremble before the approach of thunder. But throughout this volume I have given many illustrations. But one of the largest and most important practical problems of meteorology is to ascertain the course which storms follow, and the causes by which that course is determined, so that a forecast may thereby be made, not only of the certain approach of a storm, but the particular direction and force of the storm. The method of conducting this large inquiry most effectively was devised by the French astronomer, Le Verrier--the great aspirant, with our own Couch Adams, for the discovery of the planet Neptune. He began to carry this out in 1858 by the daily publication of weather data, followed by a synchronous weather map, which showed graphically for the morning of the day of publication the atmospheric pressure and the direction and force of the wind, together with tables of temperature, rainfall, cloud, and sea disturbances from a large number of places in all parts of Europe. It is from similar maps that forecasts of storms are still framed, and suitable warnings issued; and a mass of information is being collected by telegraph from sixty stations in the British Islands, &c., of the state of the weather at eight o'clock every morning, and analysed and arranged at the Meteorological Office in London for the evening's forecasts over the different districts of the country. A juster knowledge is being now acquired of those great atmospheric movements, and other changes, which form the groundwork of weather-forecasting. The Meteorological Office, Westminster (entirely distinct from the Royal Meteorological Society), is administered by a Council (Chairman, Sir R. Strachey; Scottish member, Dr. Buchan), selected by the Royal Society. It employs a staff of over forty. The chief departments relate to: (1) Ocean Meteorology, including the collection, tabulation, and discussion of meteorological data from British ships, the preparation of ocean weather charts, and the issue of meteorological instruments to the Royal Navy and Mercantile Marine; (2) Weather Telegraphy, including the reception of telegrams thrice a day from selected stations for the preparation of the daily reports and weather forecasts. Representatives of newspapers, &c., receive copies of the 11 A.M. forecast based on the 8 A.M. observations; and also of the 8.30 P.M. forecasts based on the observations received earlier in the day. In summer and autumn harvest forecasts are issued by telegraph to individuals who will defray the cost. The Office also collects climatological data from a number of voluntary and some subsidised stations. The "first order" stations include Valentia, Falmouth, Kew, and Aberdeen. These have self-recording instruments of high precision, giving a continuous record of the meteorological elements. A Government Commission which sat last year, under the Rt. Hon. Sir Herbert Maxwell, Bart., have issued a Report, recommending a number of changes in the management and constitution of the Meteorological Office; and considerable modifications are not unlikely to take place in the near future. In his evidence before that Commission, the Chairman of the Council acknowledged that the great function of meteorologists is the collection of facts; but the interpretation of those collected facts, in a scientific manner, is still in a very immature condition. Dr. Buchan, in his evidence, confessed that forecasting by the Council is purely "by rule of thumb." It is not possible to lay down hard and fast rules for forecasting. With regard to the storm-warning telegrams, as a rule, the earliest trustworthy indication of the approach of a dangerous storm to the coasts of the British Isles precedes the storm by only a few hours. Delays are therefore very serious. It is admitted by the best British meteorologists that the observations of the United States are better conducted, although the best instruments in the world are set and registered at Kew, in England. The work of weather forecasts and storm warnings is carried on with the highest degree of promptitude and efficiency at the Washington Central Office. This is because the work of predictions has been hitherto the chief work of the Office: the entire time of the observers, on whose telegraphic reports the forecasts are based, is controlled by the United States Weather Bureau; and the right of precedence in the use of wires is maintained. Professor Brückner, of Berne, has devoted a lifetime to the comparatively new treatment of climatic oscillations, based upon observations made at 321 points on the earth's surface, distributed as follows: Europe, 198; Asia, 39; N. America, 50; Cen. and S. America, 16; Australia, 12; Africa, 6. One of his conclusions is that an average time of about thirty-five years is found to intervene between one period of excess or deficiency of warmth and the next, accompanied by the opposite relative condition of moisture. All are familiar with the hoisting of cone-warning as indication of a coming storm. This work is exceedingly important, especially for those connected with the sea by business or pleasure. On the known approach of a cyclone of dangerous intensity, special messages are sent from the London Meteorological Office, warning the coasts likely to be affected. When the cone is hoisted with its apex downwards, it means that strong south or south-west winds are to be looked for. When the cone is hoisted with its apex upwards, it indicates that strong winds from the north or north-east are expected. Of course they are merely useful precautions; but they are universally attended to by people on the sea-coast. Though one may have reasonable doubts about the use that can be made of weather forecasts for three days, such as are now regularly issued, on account of the finical, coy, spasmodic interludes on short notice, yet there is a wonderful certainty in the daily prognostics of the direction and strength of the wind, the temperature of the air, and the likelihood of rainy or fair weather, dependent on the broad uniformity of nature. This is very serviceable for people who have now to live at high pressure in business, in the enthralling days of keen competition. And it is a great boon to those who are in search of health by travelling, or who, in innocent pleasure, desire to live as much as possible in the open air. Very little credit is given to the "gas" of the isolated "weather prophet"; but those who have confidence in the usual weather forecasts from the Meteorological Office are satisfied in their belief; and those who, in self-confidence, ignore all weather prognostics, are still weak enough to read them and act up to them. In practical meteorology, in the scientific explanation of popular weather-lore, and in the study of atmospheric phenomena, which so powerfully influence us, for gladness or discomfort, we may, as with other branches of science, even all our days, cheerfully go on in "the noiseless tenor of our way," "Nourishing a youth sublime, With the fairy tales of science and the long results of time." INDEX Abercromby, spectre on Adam's Peak, 89 Adam's Peak, spectre, 89 Afterglow described, 62; dust-particles to form, 64 Air, change of, 55; clearness and dryness, 49; devitalised, 52; disease-germs in, 53; thunder-clouds, 49 Aitken, Dr., afterglows, 67; anti-cyclones, 97; colour of water, 75; condensing power of dust, 2; decay of clouds, 39; dew-formation, 14; dust and atmospheric phenomena, 29; electrical deposition of smoke, 83; false dew, 18; fog-counter, 82; foreglows, 67; formation of clouds, 35; haze, 44; hazing effects of atmospheric dust, 47; Kingairloch experiments, 30; one-coloured rainbow, 70; radiation from snow, 86; regenerators, 85; sanitary detective, 78 Ammonia and cloud formation, 36 Annie Laurie, 17 Anti-cyclones, forecasting by, 97; formation, 97; cause of influenza, 109 Aratus, forecasting by moon, 61 Ariel's song, 42 Aurora Borealis, 71; forebodings, 71-73; name by Gassendi, 72; other names, 72; safety valve of electricity, 72; sun's spots, 72; sun control, 74; symptoms, 72 Bagillt, condensing lead fumes, 84 Ballachulish, sunsets, 64 Ballantine's song, 17 Barometer, indications, 10 Ben Nevis, dust-particles, 30; instruments, 104; meteorology, 102; observations, 105; rainfall, 103; regret at stoppage of Observatory, 103 Blairgowrie, personal description of afterglow, 62 Blue sky, 74; cause of, 75, 77 Borrowing days, 117 Brocken, spectre, 89; personal description, 90; Noah's Ark, 90 Brückner, climatic oscillations, 122 Buchan, Dr., Aitken's radiation from snow, 86; Ben Nevis, papers on, 103; _Challenger_ Reports, 114; cold of 1886, 86; east winds, 94; isobars, 115; rainfall statistics, 100; on forecasting, 121 Buchanan, Ben Nevis Observatory, 102; great prevalence of fog, 106 Buddha's Lights, of Ceylon, 72 Burns, allusions to aurora, 71, 73 Byron, storm in Alps, 50 _Challenger_ Expedition, 114; temperature, 115; thunder-storms, 116; winds, 116 Chambers on sun-spots and grain prices, 113 Change of air, 55; Strathmore to Glenisla, 56 Charles II., fog and smoke, 80 Chlorine and cloud formation, 36 Christison and colour of water, 75 Chrystal on Aitken's radiation from snow, 86 Cirro-stratus cloud, mackerel-like, 39 Climate, _Challenger_ notes, 115; cone-warnings, 120; Gulf Stream, 111; oscillations, 120; rainfall, 111; sun-spots on, 112; wooded country on, 111 Clouds, decay of, 37; distances of, 35; dry, 42; even without dust, 36; formation of, 34; height of, 34; numbering of cloud-particles, 34; sunshine on cloud formation, 35; varieties of, 35 Cone-warnings, 121 Continental winds, 98 Cyclones, 95; formation of, 96, 98; small natural, 98 Decay of clouds, 37; in thin rain, 41; process, 38; ripple markings, 39 Dew, evidence of rising, 22; experiments, 15, 16; false dew, 17; formation of, 13 Disease-germs in air, 53; causes, 53; deposited by rain, 55 Diseases, and east wind, 94; personal notes, 95 Dumfries, dust in air at, 46 Dust, condensing power, 43; from meteors, 37; generally necessary for cloud formation, 26; hazing effects, 47; numbering, 26; instruments for numbering, 27; produces afterglows, 64; produces foreglows, 67; quantity in Bunsen flame, 28; at Ben Nevis, 30; Hyères, Mentone, Rigi Kulm, 29; Lucerne, Kingairloch, 30; when not necessary, 36 Dust enumeration, deductions on, 31 Earn, Loch, splash of drop at, 101 Earthshine, 59 Ehrenberg, on colour of water, 75 Evelyn, fumifugium, 80; remedy for smoke, 82 Falkirk, Dr. Aitken's experiments on haze, 47 False dew, 19 Fitzroy on aurora as a foreboder, 73 Fog, counter, 31; dry, 41; formation, 24; more in towns, 25; and smoke, 80 Folk-lore, 50 Foreglow, described, 66; how produced, 67 Fort William Observatory, 102 Frankland, disease-germs, 53 Franklin, lightning, 51 Gassendi, named aurora, 72 Gillespie, Dr., on weather and influenza, 107 Glasgow, fog, 81 Glass, appearing damp, 44 Glenisla, ozoned air, 56 Grain crops and sun-spots, 112; Chambers' tables, 113 Great amazing light in the north, 72 Gulf Stream, effects on climate, 111 Gunpowder, great condensing power, 44 Haze, what is, 43; how produced, 44; in clearest air, 45; stages of condensation, 46; in sultry weather, 46; dryness of air and visibility, 48 Health improved by change of air, 56 Highland air, few disease-germs, 55 Hoar-frost, frozen dew, 20; on under surfaces, 21 Humboldt, isotherms, 114 Hydrogen peroxide and cloud formation, 36 Hyères, dust-particles, 29 Indian Ocean, colour, 75 Influenza, weather and, 107; six distinct epidemics, 108; spread of anti-cyclonic conditions, 109 Isobars by Buchan, 115 Isotherms by Humboldt, 114 Italian lakes, stages of condensation, 45 Job, on dew formation, 13 Kelvin recorder, 84; Aitken's radiation from snow, 86 Kew, instruments set, 121 Kingairloch, dust-particles, 30, 46 Kirchhoff, lower temperature of sun-spot, 112 Krakatoa, eruption of, dust-particles, 63 Le Verrier and weathercharts, 119 Lockyer, and sun-spots, 112 Lightning, electricity, 51; photographed, 51; sheet and forked, 51; ozone, 52 Lodge, electrical deposition of smoke, 83 London, coals consumed, 25; sulphur and fog, 25; fog in reign of Charles II., 81; Meteorological Office, 11, 120 Lord Derwentwater's Lights, 72 Lower animals, sensitiveness, 11 Lucerne, dust-particles, 30 MacLaren, Aitken's radiation from snow, 86 Magnesia, small affinity for water-vapour, 44 Man in the street, 11 Mediterranean, brilliant colour, 77 Mentone, dust-particles, 29 Merry Dancers of Shetland, 71 Meteors, producing dust, 37 Meteorological Council, London, 103; Office, 120; cone-warnings, 121; regular forecasts, 123 Milne Home on Ben Nevis, 103 Milton, dust numberless, 26 Moon, old, in new moon's arms, 58; weather indications, 59, 61 Mountain giants, 88; Adam's Peak, 89; Brocken, 89 Munich, International Meteorological Conference, 35 Murray, _Challenger_ Expedition, 114 Nardius, dew exhalation, 13 Newton, colour of sky, 77 Nimbus, cloud, 35 Oak and ash, on climate, 118 Ochils, one-coloured rainbow, 70 Pacific, colour, 75 Paris, aurora, 71; disease-germs, 55 Paton, Waller, bronze tints in sunsets, 64 Piazzi Smith, aurora, 72 Picket, dew-formation, 14 Pilatus, fine rain, 42 Polar lightnings, 72 Radiant heat, producing fine rain, 41 Radiation from snow, 86 Rain, 98; heavy rainfalls, 99 Rainbow, 68; forecasts, 62, 69; formation, 69; one-coloured, 70 Rains, it always, 40; radiant heat in process, 41; Ariel's song, 43 Rankin, dust-particles, Ben Nevis, 30 Richardson, devitalised air, 51 Rigi Kulm, dust-particles, 29 Rolier, aurora, 73 St. Paul's, London, disease-germs in air, 54 Sanitary detective, 78 Shakespeare, tempest, 95 Shelley, old moon in new moon's arms, 59 Simoom and sirocco, 94 Skye, rainy, 40 Smoke, electrical deposition of, 83; regenerators, 85 Smoking-room, condensing power, 44 Snow, bad conducting, 87; radiation from, 86 Sodium dust, condensing power, 45 Spens, forebodings of moon, 61 Splash of a drop, experiments, 101 Stevenson, R. L., splash of drop, 101 Stewart, sun-spots, 112 Strachey on forecasts, 121 Strathmore, observations on hoar-frost, 22; on decay of clouds, 38; to Glenisla, change of air, 56; observations on old moon in new moon's arms, 59; afterglow described, 62; foreglow, 66; cold of 1886, 86; healthy by woods, 111; observations on barometer, 118 Strathpeffer, 9 Sulphur as a fog-former, 25 Sulphuretted hydrogen and cloud-formation, 36 Sunshine on cloud-formation, 35 Sun's spots, and aurora, 72, 112; and grain crops, 112 Symons, rainfall, 100 Synoptic charts, 98 Tait, on Aitken's radiation from snow, 86 Tay Bridge, fall of, 92 Tennyson, aurora, 71; dew, 19; oak and ash, 119 Thermometer, indications, 10 Thomson, Wyville, _Challenger_ Expedition, 114 Thunder-storm described, 50 Valkyries, aurora, 73 Visibility, limit of, 48 Washington, Meteorological Office, 121 Water, pressure to show plant exudation, 18; colour of, 75; experiments on distilled, 76; dust-particles vary colour, 77 Weather and influenza, 107 Weather-forecasting, 116; advantages, 117; principle, 117; examples, 118; old moon in new moon's arms, 59; by moon, 61; oak and ash, 118; cone-warnings, 122; three days', 123 Weather-lore, 50, 118 Weather talisman, 9; call on barometer and thermometer, 10; exceptional years, 117 Wells, Dr., on dew, 14 Wilson, Prof., on hoar-frost, 20 Wind, 92; rates, 92; trade, 93; land and sea, 93 Woeikof, durability of cold, 88 Wordsworth, rainbow, 68 Worthington, splash of drop, 100 Wragge, observations at Ben Nevis, 104 Printed by BALLANTYNE, HANSON & CO. Edinburgh & London	40,405	common-pile/project_gutenberg_filtered	38928	project gutenberg	project_gutenberg-dolma-0006.json.gz:391	https://www.gutenberg.org/ebooks/38928.txt.utf-8
zs82VcaJSmRrswAK	1.4: Conducting Background Research in the Sciences	1.4: Conducting Background Research in the Sciences Before addressing a research problem with an experiment, it’s important to conduct background research in order to learn what is already known about the problem. It’s a good idea to start any research project by making use of the resources at your institution’s library. The Iowa State University Library has several resource guides available that are specific for an area of study. These can make it much easier to search for the appropriate information for a particular type of research question. Here is the resource guide for Kinesiology at ISU: Kinesiology Research Guide at Iowa State University (external link) Resource Types There are many types of resources that may be valuable for a literature search. Primary literature includes original written works such as research published in scholarly journals. Primary literature is the ideal resource for academic work; however, the terminology used may be difficult to understand for beginners in a field of study. Secondary sources include books or review articles that summarize primary research findings. A good example of a secondary resource is a textbook. Today, various internet resources are popular for conducting research. For information on how to wisely use internet resources, please see the section on evaluating internet resources at the end of this chapter. How to Read a Scientific Article Reading a scientific article is a complex task. [1] The worst way to approach this task is to treat it like the reading of a textbook—reading from title to literature cited, digesting every word along the way without any reflection or criticism. Rather, you should begin by skimming the article to identify its structure and features. As you read, look for the author’s main points. Generate questions before, during, and after reading. Draw inferences based on your own experiences and knowledge. And to really improve understanding and recall, take notes as you read. This handout discusses each of these strategies in more detail. Skim the article and identify its structure Most journals use a conventional IMRD structure: An abstract followed by Introduction, Methods, Results, and Discussion. Each of these sections normally contains easily recognized conventional features, and if you read with an anticipation of these features, you will read an article more quickly and comprehend more. Features of Abstracts Abstracts usually contain four kinds of information: - purpose or rationale of study (why they did it) - methodology (how they did it) - results (what they found) - conclusion (what it means) Most scientists read the abstract first. Others—especially experts in the field—skip right from the title to the visuals because the visuals, in many cases, tell the reader what kinds of experiments were done and what results were obtained. You should probably begin reading a paper by reading the abstract carefully and noting the four kinds of information outlined above. Then move first to the visuals and then to the rest of the paper. Features of Introductions Introductions serve two purposes: creating readers’ interest in the subject and providing them with enough information to understand the article. Generally, introductions accomplish this by leading readers from broad information (what is known about the topic) to more specific information (what is not known) to a focal point (what question the authors asked and answered). Thus, authors describe previous work that led to current understanding of the topic (the broad) and then situate their work (the specific) within the field. Features of Methods The Methods section tells the reader what experiments were done to answer the question stated in the Introduction. Methods are often difficult to read, especially for graduate students, because of technical language and a level of detail sufficient for another trained scientist to repeat the experiments. However, you can more fully understand the design of the experiments and evaluate their validity by reading the Methods section carefully. Features of Results and Discussion The Results section contains results—statements of what was found, and reference to the data shown in visuals (figures and tables). Normally, authors do not include information that would need to be referenced, such as comparison to others’ results. Instead, that material is placed in the Discussion—placing the work in context of the broader field. The Discussion also functions to provide a clear answer to the question posed in the Introduction and to explain how the results support that conclusion. Distinguish the Main Points Because articles contain so much information, it may be difficult to distinguish the main points of an article from the subordinate points. Fortunately, there are many indicators of the author’s main points: Document level - Title - Abstract - Keywords - Visuals (especially figure and table titles) - First sentence or the last 1-2 sentences of the Introduction Paragraph level: words or phrases to look for - surprising - unexpected - in contrast with previous work - has seldom been addressed - we hypothesize that - we propose - we introduce - we develop - the data suggest Generate questions and be aware of your understanding Reading is an active task. Before and during your reading, ask yourself these questions: - Who are these authors? What journal is this? Might I question the credibility of the work? - Have I taken the time to understand all the terminology? - Have I gone back to read an article or review that would help me understand this work better? - Am I spending too much time reading the less important parts of this article? - Is there someone I can talk to about confusing parts of this article? After reading, ask yourself these questions: - What specific problem does this research address? Why is it important? - Is the method used a good one? The best one? - What are the specific findings? Am I able to summarize them in one or two sentences? - Are the findings supported by persuasive evidence? - Is there an alternative interpretation of the data that the author did not address? - How are the findings unique/new/unusual or supportive of other work in the field? - How do these results relate to the work I’m interested in? To other work I’ve read about? - What are some of the specific applications of the ideas presented here? What are some further experiments that would answer remaining questions? Draw inferences Not everything that you learn from an article is stated explicitly. As you read, rely on your prior knowledge and world experience, as well as the background provided in the article, to draw inferences from the material. Research has shown that readers who actively draw inferences are better able to understand and recall information. Template for Taking Notes on Research Articles: Easy access for later use Whenever you read an article, pertinent book chapter, or research on the web, use the following format (or something similar) to make an electronic record of your notes for later easy access. Put quotation marks around any exact wording you write down so that you can avoid accidental plagiarism when you later cite the article. Complete citation. Author(s), Date of publication, Title (book or article), Journal, Volume #, Issue #, pages: If web access: url; date accessed Key Words: General subject: Specific subject: Hypothesis: Methodology: Result(s): Summary of key points: Context (how this article relates to other work in the field; how it ties in with key issues and findings by others, including yourself): Significance (to the field; in relation to your own work): Important Figures and/or Tables (brief description; page number): Cited References to follow up on (cite those obviously related to your topic AND any papers frequently cited by others because those works may well prove to be essential as you develop your own work): How to Spot Fake News Wikipedia Wikipedia is broadly misunderstood by faculty and students alike. [2] While Wikipedia must be approached with caution, especially with articles that are covering contentious subjects or evolving events, it is often the best source to get a quick, consensus viewpoint on a subject. Because the Wikipedia community has strict rules about sourcing facts to reliable sources, and because authors are asked to adopt a neutral point of view, its articles are often a good introduction to a subject on the web. However, be advised that anyone can edit Wikipedia, and those who write or add to articles may not be experts. Sometimes the claims in Wikipedia articles are blatantly erroneous. Despite this, the focus on sourcing claims in Wikipedia has a beneficial effect. If you can find a claim expressed in a Wikipedia article, you can follow the footnote on the claim to a reliable source, which may be a primary resource. In this way, scholars can benefit from using Wikipedia to quickly find authoritative sources for claims, and use these primary resources as a starting point for investigating a question. Evaluating Internet Resources: the CRAAP Test When you search for information, you’re going to find plenty… but is it accurate and reliable (Fig. 1)? [3] You will have to determine this for yourself, and the CRAAP Test can help. The CRAAP Test is a list of questions to help determine if the information you find is good quality. Your information source may not meet every criterion on this list; different criteria will be more or less important depending on your situation or need. So why guess? Is your source giving you truly credible and useful information or just fake news? Currency: The timeliness of the information. - When was the information published or posted? - Has the information been revised or updated? - Is the information current or too out-of-date for my topic? - Are all the links functional or are there dead links? Reliability: Where did the author get this information? - Does the creator provide links to sources for data or quotations? - Do those sources seem reliable? - Is the information accurate and error-free? - Can the information be corroborated with another source? Authority of author: Who is the immediate source of the information? - Who is the author/publisher/source/sponsor? - Are the author’s credentials or organizational affiliations given? - What are the author’s credentials or organizational affiliations? - What are the author’s qualifications to write on the topic? - Is there contact information, such as a publisher or e-mail address? - Does the URL reveal anything about the author or source? Examples: .com .edu .gov .org .net Authority of organization: Does the resource have a reputable organization behind it? - Is there a reputable organization behind it? - What is the organization’s interest (if any) in this information? - What is the domain (.edu,.com,.org,.net,.uk,.k12,etc)? - Is the page hosted by an individual? Search who owns the site using a “whois” search engine such as: http://whois.domaintools.com . - Who else links to the site? Purpose: The reason the information exists. - What is the purpose of the information? to inform? teach? sell? entertain? persuade? - Do the authors/sponsors make their intentions or purpose clear? - Is the information fact? opinion? propaganda? - Does the point of view appear objective and impartial? - Are there political, ideological, cultural, religious, institutional, or personal biases? - © Mar 28, 2008 The Cain Project in Engineering and Professional Communication. Textbook content produced by The Cain Project in Engineering and Professional Communication is licensed under a Creative Commons Attribution License 2.0 license. Download for free at http://cnx.org/contents/d85e82ee-f854-4953-a194-8ec1baf39348@1 ↵ - Adapted from Web literacy for student fact checkers , by Michael A. Caulfield. CC by 4.0 International license ↵ - Adapted from https://uri.libguides.com/start/craap CC by 4.0 International license . ↵	2,501	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Labs%3A_A_Mixed_Course_Based_Research_Approach_to_Human_Physiology_(Whitmer)/01%3A_Introductory_Material/1.04%3A_Conducting_Background_Research_in_the_Sciences	libretexts	libretexts-0000.json.gz:47268	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Labs%3A_A_Mixed_Course_Based_Research_Approach_to_Human_Physiology_(Whitmer)/01%3A_Introductory_Material/1.04%3A_Conducting_Background_Research_in_the_Sciences
rNuX8BKZDb52lLMP	Macroeconomics	204 Why It Matters: Policy Applications Why apply fiscal and monetary policies in macroeconomic situations? The module really ties together everything we’ve learned about macroeconomics. In earlier modules we introduced the concepts of fiscal and monetary policy. In this module, we examine the two types of policy in more detail, incorporating all the pros and cons of the real world. By extension, we will be evaluating the policy prescriptions of Keynesian and neoclassical economics. As you work through this module, use the following questions to guide your thinking: - Under what circumstances do fiscal and monetary policy work well, or not so well, in managing the economy? - For the activist Keynesians, what are the limits to fiscal and monetary policy that you would endorse, and why? - For the laissez-faire neoclassicals, what is the minimalist fiscal and monetary policy that makes sense, and why? - How is macroeconomic policy is the real world more complicated than in theory? Suppose you are asked to provide guidance about the macro economy in a given situation. Knowing what you know about the strengths and weaknesses of using fiscal or monetary policy, what would you recommend? For example, suppose after a period of solid economic growth, low unemployment, and modest inflation, the economy slows down a bit and unemployment shoots up several percentage points. What, if anything, should be done about that?	297	common-pile/pressbooks_filtered	https://library.achievingthedream.org/sacmacroeconomics/chapter/why-it-matters-policy-applications/	pressbooks	pressbooks-0000.json.gz:81630	https://library.achievingthedream.org/sacmacroeconomics/chapter/why-it-matters-policy-applications/
XTy_kDXqDkDE2K0X	MSMP Digital Textbook Style and Procedures	Standard Operating Procedures General Settings Book Info In Pressbooks, the Book Info page, found in the left hand navigation pane, is where to adjust specific public details (metadata) about your book that display on the book’s homepage and in exports. Many of the sections provided are optional and only become necessary to include as the book is shared throughout a variety of platforms and mediums. The required Book Info fields to complete for MSMP interactive textbooks include: - Title - Authors - Cover Image - Copyright Title The title of each book under the MSMP umbrella should reflect the full name of each course, without the specific course number, that the book coincides with. For example, the book created for the course “VEM5321:Integrating Veterinary Medicine with Shelter Systems” is simply titled Integrating Veterinary Medicine with Shelter Systems. Authors The authors of each book will vary from course to course. Authors must be added as “contributors” in order to display proper attribution on the book’s home page. For more information about the Book Info page and how to create contributors, see here. Cover Image A unique cover image has been designed for each MSMP course book. Copyright and Creative Commons A copyright notice is standard and required for all books. Pressbooks generates a default copyright notice for all book formats which will include your book’s title and the author’s names. The default copyright license when creating a new book is set to All Rights Reserved which does not allow for ease of duplication of our books. The following information should be adjusted in the Copyright section in order to be included in the automatically generated copyright notice on the book’s home page: - Copyright year: This will vary - Name of the copyright holder: University of Florida - Copyright license: CC BY-NC-ND (Attribution NonCommercial NoDerivatives) For more information about copyright and Creative Commons licenses, see here. Social Media Pressbooks allows the options for users to share out parts or the entire book on social media, specifically Twitter. MSMP has elected to turn this feature off on all books. To adjust this, hover over the Appearance section found in the lefthand navigation panel, then select Theme Options, then Web Options. The very first toggle button found under Web Options should be unchecked to turn this Twitter sharing feature off. Content Pages (Parts and Chapters) Parts and Chapters should be set in Organize to Show in Web, Exports, Title. To ensure accessibility, heading structures should be sequential; the page title will default to H1 so the first selection one should make with content is H2. Any hyperlinks should be edited to change the default setting to “Open link in a new tab”. Export AND Sharing & Privacy When the book is ready for sharing, Export (left-hand navigation, not the one under Setting) a digital PDF and EPUB (you may also need to select the Share setting described below since the default is No). If you edit the book at a later date, you will need to re-export both files of the book (the latest version will update automatically for download from the cover). Global Privacy controls whether your webbook is accessible to the public. MSMP webbooks should be set to public in order for students to access our content from anywhere without the necessary step of creating individual user accounts. All books have the Global Privacy setting automatically set to private. You must intentionally make your book public for it to be accessible to readers. You can find the Global Privacy setting and change it to public by going to: - Settings > Sharing & Privacy from the left-hand navigation menu - Book Visibility: Public - Share Latest Export Files: Yes For more information about webbooks privacy settings, see here.	815	common-pile/pressbooks_filtered	https://ufl.pb.unizin.org/msmpstyleguide/chapter/general-settings/	pressbooks	pressbooks-0000.json.gz:5492	https://ufl.pb.unizin.org/msmpstyleguide/chapter/general-settings/
9KKqCjqS8E_GNirU	4.13: Kernels and Operators	4.13: Kernels and Operators The goal of this section is to study a type of mathematical object that arises naturally in the context of conditional expected value and parametric distributions, and is of fundamental importance in the study of stochastic processes, particularly Markov processes. In a sense, the main object of study in this section is a generalization of a matrix, and the operations generalizations of matrix operations. If you keep this in mind, this section may seem less abstract. Basic Theory Definitions Recall that a measurable space $ (S, \mathscr S) $ consists of a set $ S $ and a $ \sigma $-algebra $ \mathscr S $ of subsets of $ S $. If $ \mu $ is a positive measure on $ (S, \mathscr S) $, then $ (S, \mathscr S, \mu) $ is a measure space. The two most important special cases that we have studied frequently are - Discrete : $S$ is countable, $\mathscr S = \mathscr P(S)$ is the collection of all subsets of $S$, and $ \mu = \# $ is counting measure on $ (S, \mathscr S) $. - Euclidean : $S$ is a measurable subset of $\R^n$ for some $n \in \N_+$, $\mathscr S$ is the collection of subsets of $S$ that are also measurable, and $ \mu = \lambda_n $ is $ n $-dimensional Lebesgue measure on $ (S, \mathscr S) $. More generally, $ S $ usually comes with a topology that is locally compact, Hausdorff, with a countable base ( LCCB ), and $ \mathscr S $ is the Borel $ \sigma $-algebra , the $ \sigma $-algebra generated by the topology (the collection of open subsets of $ S $). The measure $ \mu $ is usually a Borel measure , and so satisfies $ \mu(C) \lt \infty $ if $ C \subseteq S $ is compact. A discrete measure space is of this type, corresponding to the discrete topology. A Euclidean measure space is also of this type, corresponding to the Euclidean topology, if $ S $ is open or closed (which is usually the case). In the discrete case, every function from $ S $ to another measurable space is measurable, and every from function from $ S $ to another topological space is continuous, so the measure theory is not really necessary. Recall also that the measure space $(S, \mathscr S, \mu)$ is $\sigma$-finite if there exists a countable collection $\{A_i: i \in I\} \subseteq \mathscr S$ such that $\mu(A_i) \lt \infty$ for $i \in I$ and $S = \bigcup_{i \in I} A_i$. If $(S, \mathscr S, \mu)$ is a Borel measure space corresponding to an LCCB topology, then it is $\sigma$-finite. If $f: S \to \R$ is measurable, define $ \\| f \\| = \sup\{\left\|f(x)\right\|: x \in S\}$. Of course we may well have $\\|f\\| = \infty$. Let $ \mathscr B(S) $ denote the collection of bounded measurable functions $ f: S \to \R $. Under the usual operations of pointwise addition and scalar multiplication, $ \mathscr B(S) $ is a vector space, and $\\| \cdot \\|$ is the natural norm on this space, known as the supremum norm . This vector space plays an important role. In this section, it is sometimes more natural to write integrals with respect to the positive measure $ \mu $ with the differential before the integrand, rather than after. However, rest assured that this is mere notation, the meaning of the integral is the same. So if $ f: S \to \R $ is measurable then we may write the integral of $ f $ with respect to $ \mu $ in operator notation as \[ \mu f = \int_S \mu(dx) f(x) \] assuming, as usual, that the integral exists. This will be the case if $ f $ is nonnegative, although $ \infty $ is a possible value. More generally, the integral exists in $ \R \cup \{-\infty, \infty\} $ if $ \mu f^+ \lt \infty $ or $ \mu f^- \lt \infty$ where $ f^+ $ and $ f^- $ are the positive and negative parts of $ f $. If both are finite, the integral exists in $ \R $ (and $ f $ is integrable with respect to $ \mu $). If If $ \mu $ is a probability measure and we think of $ (S, \mathscr S) $ as the sample space of a random experiment, then we can think of $ f $ as a real-valued random variable, in which case our new notation is not too far from our traditional expected value $ \E(f) $. Our main definition comes next. Suppose that $ (S, \mathscr S) $ and $ (T, \mathscr T) $ are measurable spaces. A kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ is a function $ K: S \times \mathscr T \to [0, \infty] $ such that - $ x \mapsto K(x, A) $ is a measurable function from $S$ into $[0, \infty]$ for each $ A \in \mathscr T $. - $ A \mapsto K(x, A) $ is a positive measure on $ \mathscr T $ for each $ x \in S $. If $ (T, \mathscr T) = (S, \mathscr S) $, then $ K $ is said to be a kernel on $ (S, \mathscr S) $. There are several classes of kernels that deserve special names. Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Then - $K$ is $\sigma$-finite if the measure $K(x, \cdot)$ is $\sigma$-finite for every $x \in S$. - $ K $ is finite if $ K(x, T) \lt \infty $ for every $ x \in S $. - $ K $ is bounded if $ K(x, T) $ is bounded in $ x \in S $. - $ K $ is a probability kernel if $ K(x, T) = 1 $ for every $ x \in S $. Define $ \\|K\\| = \sup\{K(x, T): x \in S\} $, so that $\\|K\\| \lt \infty$ if $K$ is a bounded kernel and $\\|K\\| = 1$ if $K$ is a probability kernel. So a probability kernel is bounded, a bounded kernel is finite, and a finite kernel is $\sigma$-finite. The terms stochastic kernel and Markov kernel are also used for probability kernels, and for a probability kernel $ \\|K\\| = 1 $ of course. The terms are consistent with terms used for measures: $ K $ is a finite kernel if and only if $ K(x, \cdot) $ is a finite measure for each $ x \in S $, and $ K $ is a probability kernel if and only if $ K(x, \cdot) $ is a probability measure for each $ x \in S $. Note that $ \\|K\\| $ is simply the supremum norm of the function $ x \mapsto K(x, T) $. A kernel defines two natural integral operators, by operating on the left with measures, and by operating on the right with functions. As usual, we are often a bit casual witht the question of existence. Basically in this section, we assume that any integrals mentioned exist. Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. - If $ \mu $ is a positive measure on $ (S, \mathscr S) $, then $ \mu K $ defined as follows is a positive measure on $ (T, \mathscr T) $: \[ \mu K(A) = \int_S \mu(dx) K(x, A), \quad A \in \mathscr T \] - If $ f: T \to \R $ is measurable, then $ K f: S \to \R $ defined as follows is measurable (assuming that the integrals exist in $ \R $): \[K f(x) = \int_T K(x, dy) f(y), \quad x \in S\] Proof - Clearly $ \mu K(A) \ge 0 $ for $ A \in \mathscr T $. Suppose that $ \{A_j: i \in J\} $ is a countable collection of disjoint sets in $ \mathscr T $ and $ A = \bigcup_{j \in J} A_j $. Then \begin{align} \mu K(A) & = \int_S \mu(dx) K(x, A) = \int_S \mu(dx) \left(\sum_{j \in J} K(x, A_j) \right) \\ & = \sum_{j \in J} \int_S \mu(dx) K(x, A_j) = \sum_{j \in J} \mu K(A_j) \end{align} The interchange of sum and integral is justified since the terms are nonnegative. - The measurability of $ K f $ follows from the measurability of $ f $ and of $ x \mapsto K(x, A) $ for $ A \in \mathscr S $, and from basic properties of the integral. Thus, a kernel transforms measures on $ (S, \mathscr S) $ into measures on $ (T, \mathscr T) $, and transforms certain measurable functions from $ T $ to $ \R $ into measurable functions from $ S $ to $ \R $. Again, part (b) assumes that $ f $ is integrable with respect to the measure $ K(x, \cdot) $ for every $ x \in S $. In particular, the last statement will hold in the following important special case: Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ and that $ f \in \mathscr B(T) $. - If $ K $ is finite then $Kf$ is defined and $\\|Kf\\| = \\|K\\| \\|f\\|$. - If $K$ is bounded then $Kf \in \mathscr B(T)$. Proof - If $ K $ is finite then \[ K \left\|f\right\|(x) = \int_T K(x, dy) \left\|f(y)\right\| \le \int_T K(x, dy) \\|f\\| = \\|f\\| K(x, T) \lt \infty \quad x \in S \] Hence $ f $ is integrable with respect to $ K(x, \cdot) $ for each $ x \in S $ so $Kf$ is defined. Continuing with our inequalities, we have $\|K f(x)\| \le K \|f\|(x) \le \\|f\\| K(x, T) \le \\|f\\| \\|K\\|$ so $\\|Kf\\| \le \\|K\\| \\|f\\|$. Moreover equality holds when $ f = \bs{1}_T $, the constant function 1 on $ T $. - If $ K $ is bounded then $ \\|K\\| \lt \infty $ so from (a), $ \\|K f \\| \lt \infty $. The identity kernel $ I $ on the measurable space $ (S, \mathscr S) $ is defined by $ I(x, A) = \bs{1}(x \in A) $ for $ x \in S $ and $ A \in \mathscr S $. Thus, $ I(x, A) = 1 $ if $ x \in A $ and $ I(x, A) = 0 $ if $ x \notin A $. So $ x \mapsto I(x, A) $ is the indicator function of $ A \in \mathscr S $, while $ A \mapsto I(x, A) $ is point mass at $ x \in S $. Clearly the identity kernel is a probability kernel. If we need to indicate the dependence on the particular space, we will add a subscript. The following result justifies the name. Let $ I $ denote the identity kernel on $ (S, \mathscr S) $. - If $ \mu $ is a positive measure on $ (S, \mathscr S) $ then $ \mu I = \mu $. - If $ f: S \to \R $ is measurable, then $ I f = f $. Constructions We can create a new kernel from two given kernels, by the usual operations of addition and scalar multiplication. Suppose that $ K $ and $ L$ are kernels from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, and that $ c \in [0, \infty) $. Then $ c K $ and $ K + L $ defined below are also kernels from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. - $(c K)(x, A) = c K(x, A)$ for $ x \in S $ and $ A \in \mathscr T $. - $(K + L)(x, A) = K(x, A) + L(x, A)$ for $ x \in S $ and $ A \in \mathscr T $. If $ K $ and $ L $ are $ \sigma $-finite (finite) (bounded) then $ c K $ and $ K + L $ are $ \sigma $-finite (finite) (bounded), respectively. Proof These results are simple. - Since $ x \mapsto K(x, A) $ is measurable for $ A \in \mathscr T $, so is $ x \mapsto c K(x, A) $. Since $ A \mapsto K(x, A) $ is a positive measure on $ (T, \mathscr T) $ for $ x \in S $, so is $ A \mapsto c K(x, A) $ since $ c \ge 0 $. - Since $ x \mapsto K(x, A) $ and $ x \mapsto L(x, A) $ are measurable for $ A \in \mathscr T $, so is $ x \mapsto K(x, A) + L(x, A) $. A simple corollary of the last result is that if $a, \, b \in [0, \infty)$ then $a K + b L$ is a kerneal from $(S, \mathscr S)$ to $(T, \mathscr T)$. In particular, if $K, \, L$ are probability kernels and $p \in (0, 1)$ then $p K + (1 - p) L$ is a probability kernel. A more interesting and important way to form a new kernel from two given kernels is via a multiplication operation. Suppose that $ K $ is a kernel from $ (R, \mathscr R) $ to $ (S, \mathscr S) $ and that $ L $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Then $ K L $ defined as follows is a kernel from $ (R, \mathscr R) $ to $ (T, \mathscr T) $: \[ K L(x, A) = \int_S K(x, dy) L(y, A), \quad x \in R, \, A \in \mathscr T \] - If $K$ is finite and $L$ is bounded then $K L$ is finite. - If $K$ and $L$ are bounded then $K L$ is bounded. - If $K$ and $L$ are stochastic then $K L$ is stochastic Proof The measurability of $ x \mapsto (K L)(x, A) $ for $ A \in \mathscr T $ follows from basic properties of the integral. For the second property, fix $ x \in R $. Clearly $ K L(x, A) \ge 0 $ for $ A \in \mathscr T $. Suppose that $ \{A_j: j \in J\} $ is a countable collection of disjoint sets in $ \mathscr T $ and $ A = \bigcup_{j \in J} A_j $. Then \begin{align} K L(x, A) & = \int_S K(x, dy) L(x, A) = \int_S K(x, dy) \left(\sum_{j \in J} L(y, A_j)\right) \\ & = \sum_{j \in J} \int_S K(x, dy) L(y, A_j) = \sum_{j \in J} K L(x, A_j) \end{align} The interchange of sum and integral is justified since the terms are nonnegative. Once again, the identity kernel lives up to its name: Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Then - $ I_S K = K $ - $ K I_T = K $ The next several results show that the operations are associative whenever they make sense. Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, $ \mu $ is a positive measure on $ \mathscr S $, $ c \in [0, \infty) $, and $ f: T \to \R $ is measurable. Then, assuming that the appropriate integrals exist, - $ c (\mu K) = (c \mu) K $ - $ c (K f) = (c K) f $ - $ (\mu K) f = \mu (K f)$ Proof These results follow easily from the definitions. - The common measure on $ \mathscr T $ is $ c \mu K(A) = c \int_S \mu(dx) K(x, A) $ for $ A \in \mathscr T $. - The common function from $ S $ to $ \R $ is $ c K f(x) = c \int_S K(x, dy) f(y) $ for $ x \in S $, assuming that the integral exists for $ x \in S $. - The common real number is $ \mu K f = \int_S \mu(dx) \int_T K(x, dy) f(y) $, assuming that the integrals exist. Suppose that $ K $ is a kernel from $ (R, \mathscr R) $ to $ (S, \mathscr S) $ and $ L $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Suppose also that $ \mu $ is a positive measure on $ (R, \mathscr R) $, $ f: T \to \R $ is measurable, and $ c \in [0, \infty) $. Then, assuming that the appropriate integrals exist, - $ (\mu K) L = \mu (K L) $ - $ K ( L f) = (K L) f $ - $ c (K L) = (c K) L $ Proof These results follow easily from the definitions. - The common measure on $ (T, \mathscr T) $ is $ \mu K L(A) = \int_R \mu(dx) \int_S K(x, dy) L(y, A) $ for $ A \in \mathscr T $. - The common measurable function from $ R $ to $ \R $ is $ K L f(x) = \int_S K(x, dy) \int_T L(y, dz) f(z) $ for $ x \in R $, assuming that the integral exists for $ x \in S $. - The common kernel from $ (R, \mathscr R) $ to $ (T, \mathscr T) $ is $ c K L(x, A) = c \int_S K(x, dy) L(y, A) $ for $ x \in R $ and $ A \in \mathscr T $. Suppose that $ K $ is a kernel from $ (R, \mathscr R) $ to $ (S, \mathscr S) $, $ L $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, and $ M $ is a kernel from $ (T, \mathscr T) $ to $ (U, \mathscr U)$. Then $ (K L) M = K (L M) $. Proof This results follow easily from the definitions. The common kernel from $ (R, \mathscr R) $ to $ (U, \mathscr U) $ is \[K L M(x, A) = \int_S K(x, dy) \int_T L(y, dz) M(z, A), \quad x \in R, \, A \in \mathscr U \] The next several results show that the distributive property holds whenever the operations makes sense. Suppose that $ K $ and $ L $ are kernels from $ (R, \mathscr R) $ to $ (S, \mathscr S) $ and that $ M $ and $ N $ are kernels from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Suppose also that $ \mu $ is a positive measure on $ (R, \mathscr R) $ and that $ f: S \to \R $ is measurable. Then, assuming that the appropriate integrals exist, - $(K + L) M = K M + L M$ - $ K (M + N) = K M + K N $ - $ \mu (K + L) = \mu K + \mu L $ - $ (K + L) f = K f + L f $ Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, and that $ \mu $ and $ \nu $ are positive measures on $ (S, \mathscr S) $, and that $ f $ and $ g $ are measurable functions from $ T $ to $ \R $. Then, assuming that the appropriate integrals exist, - $ (\mu + \nu) K = \mu K + \nu K $ - $ K(f + g) = K f + K g $ - $ \mu(f + g) = \mu f + \mu g $ - $ (\mu + \nu) f = \mu f + \nu f $ In particular, note that if $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, then the transformation $ \mu \mapsto \mu K $ defined for positive measures on $ (S, \mathscr S)$, and the transformation $ f \mapsto K f $ defined for measurable functions $ f: T \to \R $ (for which $ K f $ exists), are both linear operators. If $ \mu $ is a positive measure on $ (S, \mathscr S) $, then the integral operator $ f \mapsto \mu f $ defined for measurable $ f: S \to \R $ (for which $ \mu f $ exists) is also linear, but of course, we already knew that. Here is the important summary of our results when the kernel is bounded. If $ K $ is a bounded kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, then $ f \mapsto K f $ is a bounded, linear transformation from $ \mathscr B(T) $ to $ \mathscr B(S) $ and $ \\|K\\| $ is the norm of the transformation. The commutative property for the product of kernels fails with a passion. If $ K $ and $ L $ are kernels, then depending on the measurable spaces, $ K L $ may be well defined, but not $ L K $. Even if both products are defined, they may be kernels from or to different measurable spaces. Even if both are defined from and to the same measurable spaces, it may well happen that $ K L \neq L K $. Some examples are given below If $ K $ is a kernel on $ (S, \mathscr S) $ and $ n \in \N $, we let $ K^n = K K \cdots K $, the $ n $-fold power of $ K $. By convention, $ K^0 = I $, the identity kernel on $ S $. Fixed points of the operators associated with a kernel turn out to be very important. Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. - A positive measure $ \mu $ on $ (S, \mathscr S) $ such that $ \mu K = \mu $ is said to be invariant for $ K $. - A measurable function $ f: T \to \R $ such that $ K f = f $ is said to be invariant for $ K $ So in the language of linear algebra (or functional analysis), an invariant measure is a left eigenvector of the kernel, while an invariant function is a right eigenvector of the kernel, both corresponding to the eigenvalue 1. By our results above, if $ \mu $ and $ \nu $ are invariant measures and $ c \in [0, \infty) $, then $ \mu + \nu $ and $ c \mu $ are also invariant. Similarly, if $ f $ and $ g $ are invariant functions and $ c \in \R $, the $ f + g $ and $ c f $ are also invariant. Of couse we are particularly interested in probability kernels. Suppose that $ P $ is a probability kernel from $(R, \mathscr R)$ to $ (S, \mathscr S) $ and that $ Q $ is a probability kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $. Suppose also that $ \mu $ is a probability measure on $ (R, \mathscr R) $. Then - $ P Q $ is a probability kernel from $ (R, \mathscr R) $ to $ (T, \mathscr T) $. - $ \mu P $ is a probability measure on $ (S, \mathscr S) $. Proof - We know that $ P Q $ is a kernel from $ (R, \mathscr R) $ to $ (T, \mathscr T) $. So we just need to note that \[P Q(T) = \int_S P(x, dy) Q(y, T) = \int_S P(x, dy) = P(x, S) = 1, \quad x \in R \] - We know that $ \mu P $ is a positive measure on $ (S, \mathscr S)) $. So we just need to note that \[ \mu P(S) = \int_R \mu(dx) P(x, S) = \int_R \mu(dx) = \mu(R) = 1 \] As a corollary, it follows that if $ P $ is a probability kernel on $ (S, \mathscr S) $, then so is $ P^n $ for $ n \in \N $. The operators associated with a kernel are of fundamental importance, and we can easily recover the kernel from the operators. Suppose that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, and let $ x \in S $ and $ A \in \mathscr T $. Then trivially, $K \bs{1}_A(x) = K(x, A)$ where as usual, $ \bs{1}_A $ is the indicator function of $ A $. Trivially also $ \delta_x K(A) = K(x, A) $ where $ \delta_x $ is point mass at $ x $. Kernel Functions Usually our measurable spaces are in fact measure spaces, with natural measures associated with the spaces, as in the special cases described in (1) . When we start with measure spaces, kernels are usually constructed from density functions in much the same way that positive measures are defined from density functions. Suppose that $ (S, \mathscr S, \lambda) $ and $ (T, \mathscr T, \mu) $ are measure spaces. As usual, $ S \times T $ is given the product $ \sigma $-algebra $ \mathscr S \otimes \mathscr T $. If $ k: S \times T \to [0, \infty) $ is measurable, then the function $ K $ defined as follows is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $: \[ K(x, A) = \int_A k(x, y) \mu(dy), \quad x \in S, \, A \in \mathscr T \] Proof The measurability of $ x \mapsto K(x, A) = \int_A k(x, y) \mu(dy) $ for $ A \in \mathscr T $ follows from a basic property of the integral. The fact that $ A \mapsto K(x, A) = \int_A k(x, y) \mu(dy) $ is a positive measure on $ \mathscr T $ for $ x \in S $ also follows from a basic property of the integral. In fact, $ y \mapsto k(x, y) $ is the density of this measure with respect to $ \mu $. Clearly the kernel $ K $ depends on the positive measure $ \mu $ on $ (T, \mathscr T) $ as well as the function $ k $, while the measure $ \lambda $ on $ (S, \mathscr S) $ plays no role (and so is not even necessary). But again, our point of view is that the spaces have fixed, natural measures. Appropriately enough, the function $ k $ is called a kernel density function (with respect to $ \mu $), or simply a kernel function . Suppose again that $ (S, \mathscr S, \lambda) $ and $ (T, \mathscr T, \mu) $ are measure spaces. Suppose also $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ with kernel function $ k $. If $ f: T \to \R $ is measurable, then, assuming that the integrals exists, \[ K f(x) = \int_S k(x, y) f(y) \mu(dy), \quad x \in S \] Proof This follows since the function $ y \mapsto k(x, y) $ is the density of the measure $ A \mapsto K(x, A) $ with respect to $ \mu $: \[ K f(x) = \int_S K(x, dy) f(y) = \int_S k(x, y) f(y) \mu(dy), \quad x \in S \] A kernel function defines an operator on the left with functions on $ S $ in a completely analogous way to the operator on the right above with functions on $ T $. Suppose again that $ (S, \mathscr S, \lambda) $ and $ (T, \mathscr T, \mu) $ are measure spaces, and that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ with kernel function $ k $. If $ f: S \to \R $ is measurable, then the function $ f K: T \to \R $ defined as follows is also measurable, assuming that the integrals exists \[ f K(y) = \int_S \lambda(dx) f(x) k(x, y), \quad y \in T \] The operator defined above depends on the measure $ \lambda $ on $ (S, \mathscr S) $ as well as the kernel function $ k $, while the measure $ \mu $ on $ (T, \mathscr T) $ playes no role (and so is not even necessary). But again, our point of view is that the spaces have fixed, natural measures. Here is how our new operation on the left with functions relates to our old operation on the left with measures . Suppose again that $ (S, \mathscr S, \lambda) $ and $ (T, \mathscr T, \mu) $ are measure spaces, and that $ K $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ with kernel function $ k $. Suppose also that $ f: S \to [0, \infty) $ is measurable, and let $ \rho $ denote the measure on $ (S, \mathscr S) $ that has density $ f $ with respect to $ \lambda $. Then $ f K $ is the density of the measure $ \rho K $ with respect to $ \mu $. Proof The main tool, as usual, is an interchange of integrals. For $ B \in \mathscr T $, \begin{align} \rho K(B) & = \int_S \rho(dx) K(x, B) = \int_S f(x) K(x, B) \lambda(dx) = \int_S f(x) \left[\int_B k(x, y) \mu(dy)\right] \lambda(dx) \\ & = \int_B \left[\int_S f(x) k(x, y) \lambda(dx)\right] \mu(dy) = \int_B f K(y) \mu(dy) \end{align} As always, we are particularly interested in stochastic kernels. With a kernel function, we can have doubly stochastic kernels. Suppose again that $ (S, \mathscr S, \lambda) $ and $ (T, \mathscr T, \mu) $ are measure spaces and that $ k: S \times T \to [0, \infty) $ is measurable. Then $ k $ is a double stochastic kernel function if - $ \int_T k(x, y) \mu(dy) = 1 $ for $ x \in S $ - $ \int_S \lambda(dx) k(x, y) = 1 $ for $ y \in S $ Of course, condition (a) simply means that the kernel associated with $ k $ is a stochastic kernel according to our original definition. The most common and important special case is when the two spaces are the same. Thus, if $ (S, \mathscr S, \lambda) $ is a measure space and $ k : S \times S \to [0, \infty) $ is measurable, then we have an operator $ K $ that operates on the left and on the right with measurable functions $ f: S \to \R $: \begin{align} f K(y) & = \int_S \lambda(dx) f(x) k(x, y), \quad y \in S \\ K f(x) & = \int_S k(x, y) f(y) \lambda(d y), \quad x \in S \end{align} If $ f $ is nonnegative and $ \mu $ is the measure on with density function $ f $, then $ f K $ is the density function of the measure $ \mu K $ (both with respect to $ \lambda $). Suppose again that $ (S, \mathscr S, \lambda) $ is a measure space and $ k : S \times S \to [0, \infty) $ is measurable. Then $ k $ is symmetric if $ k(x, y) = k(y, x) $ for all $ (x, y) \in S^2 $. Of course, if $ k $ is a symmetric, stochastic kernel function on $ (S, \mathscr S, \lambda) $ then $ k $ is doubly stochastic, but the converse is not true. Suppose that $ (R, \mathscr R, \lambda) $, $ (S, \mathscr S, \mu) $, and $ (T, \mathscr T, \rho) $ are measure spaces. Suppose also that $ K $ is a kernel from $ (R, \mathscr R) $ to $ (S, \mathscr S) $ with kernel function $ k $, and that $ L $ is a kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $ with kernel function $ l $. Then the kernel $ K L $ from $ (R, \mathscr R) $ to $ (T, \mathscr T) $ has density $ k l $ given by \[ k l(x, z) = \int_S k(x, y) l(y, z) \mu(dy), \quad (x, z) \in R \times T \] Proof Once again, the main tool is an interchange of integrals via Fubini's theorem. Let $ x \in R $ and $ B \in \mathscr T $. Then \begin{align} K L(x, B) & = \int_S K(x, dy) L(y, B) = \int_S k(x, y) L(y, B) \mu(dy) \\ & = \int_S k(x, y) \left[\int_B l(y, z) \rho(dz) \right] \mu(dy) = \int_B \left[\int_S k(x, y) l(y, z) \mu(dy) \right] \rho(dz) = \int_B k l(x, z) \mu(dz) \end{align} Examples and Special Cases The Discrete Case In this subsection, we assume that the measure spaces are discrete, as described in (1) . Since the $ \sigma $-algebra (all subsets) and the measure (counting measure) are understood, we don't need to reference them. Recall that integrals with respect to counting measure are sums. Suppose now that $ K $ is a kernel from the discrete space $S$ to the discrete space $T$. For $ x \in S $ and $ y \in T $, let $ K(x, y) = K(x, \{y\}) $. Then more generally, \[ K(x, A) = \sum_{y \in A} K(x, y), \quad x \in S, \, A \subseteq T \] The function $ (x, y) \mapsto K(x, y) $ is simply the kernel function of the kernel $ K $, as defined above , but in this case we usually don't bother with using a different symbol for the function as opposed to the kernel. The function $ K $ can be thought of as a matrix , with rows indexed by $ S $ and columns indexed by $ T $ (and so an infinite matrix if $ S $ or $ T $ is countably infinite). With this interpretation, all of the operations defined above can be thought of as matrix operations. If $ f: T \to \R $ and $ f $ is thought of as a column vector indexed by $ T $, then $ K f $ is simply the ordinary product of the matrix $ K $ and the vector $ f $; the product is a column vector indexed by $ S $: \[K f(x) = \sum_{y \in S} K(x, y) f(y), \quad x \in S \] Similarly, if $ f: S \to \R $ and $ f $ is thought of as a row vector indexed by $ S $, then $ f K $ is simple the ordinary product of the vector $ f $ and the matrix $ K $; the product is a row vector indexed by $ T $: \[ f K(y) = \sum_{x \in S} f(x) K(x, y), \quad y \in T \] If $ L $ is another kernel from $ T $ to another discrete space $ U $, then as functions, $ K L $ is the simply the matrix product of $ K $ and $ L $: \[ K L(x, z) = \sum_{y \in T} K(x, y) L(x, z), \quad (x, z) \in S \times L \] Let $ S = \{1, 2, 3\} $ and $ T = \{1, 2, 3, 4\} $. Define the kernel $ K $ from $ S $ to $ T $ by $ K(x, y) = x + y $ for $ (x, y) \in S \times T $. Define the function $ f $ on $ S $ by $ f(x) = x! $ for $ x \in S $, and define the function $ g $ on $ T $ by $ g(y) = y^2$ for $ y \in T $. Compute each of the following using matrix algebra: - $ f K $ - $ K g $ Answer In matrix form, \[ K = \left[\begin{matrix} 2 & 3 & 4 & 5 \\ 3 & 4 & 5 & 6 \\ 4 & 5 & 6 & 7 \end{matrix} \right], \quad f = \left[\begin{matrix} 1 & 2 & 6 \end{matrix} \right], \quad g = \left[\begin{matrix} 1 \\ 4 \\ 9 \\ 16 \end{matrix} \right]\] - As a row vector indexed by $ T $, the product is $ f K = \left[\begin{matrix} 32 & 41 & 50 & 59\end{matrix}\right] $ - As a column vector indexed by $ S $, \[ K g = \left[\begin{matrix} 130 \\ 160 \\ 190 \end{matrix}\right] \] Let $ R = \{0, 1\} $, $ S = \{a, b\} $, and $ T = \{1, 2, 3\} $. Define the kernel $ K $ from $ R $ to $ S $, the kernel $ L $ from $ S $ to $ S $ and the kernel $ M $ from $ S $ to $ T $ in matrix form as follows: \[ K = \left[\begin{matrix} 1 & 4 \\ 2 & 3\end{matrix}\right], \; L = \left[\begin{matrix} 2 & 2 \\ 1 & 5 \end{matrix}\right], \; M = \left[\begin{matrix} 1 & 0 & 2 \\ 0 & 3 & 1 \end{matrix} \right] \] Compute each of the following kernels, or explain why the operation does not make sense: - $ K L $ - $ L K $ - $ K^2 $ - $ L^2 $ - $ K M $ - $ L M $ Proof Note that these are not just abstract matrices, but rather have rows and columns indexed by the appropriate spaces. So the products make sense only when the spaces match appropriately; it's not just a matter of the number of rows and columns. - $ K L $ is the kernel from $ R $ to $ S $ given by \[ K L = \left[\begin{matrix} 6 & 22 \\ 7 & 19 \end{matrix} \right] \] - $ L K $ is not defined since the column space $ S $ of $ L $ is not the same as the row space $ R $ of $ K $. - $ K^2 $ is not defined since the row space $ R $ is not the same as the column space $ S $. - $ L^2 $ is the kernel from $ S $ to $ S $ given by \[ L^2 = \left[\begin{matrix} 6 & 14 \\ 7 & 27 \end{matrix}\right] \] - $ K M $ is the kernel from $ R $ to $ T $ given by \[ K M = \left[\begin{matrix} 1 & 12 & 6 \\ 2 & 9 & 7 \end{matrix} \right] \] - $ L M $ is the kernel from $ S $ to $ T $ given by \[ L M = \left[\begin{matrix} 2 & 6 & 6 \\ 1 & 15 & 7 \end{matrix}\right] \] Conditional Probability An important class of probability kernels arises from the distribution of one random variable, conditioned on the value of another random variable. In this subsection, suppose that $ (\Omega, \mathscr{F}, \P) $ is a probability space, and that $ (S, \mathscr S) $ and $ (T, \mathscr T) $ are measurable spaces. Further, suppose that $ X $ and $ Y $ are random variables defined on the probability space, with $ X $ taking values in $ S $ and that $ Y $ taking values in $ T $. Informally, $ X $ and $ Y $ are random variables defined on the same underlying random experiment. The function $ P $ defined as follows is a probability kernel from $ (S, \mathscr S) $ to $ (T, \mathscr T) $, known as the conditional probability kernel of $ Y $ given $ X $. \[ P(x, A) = \P(Y \in A \mid X = x), \quad x \in S, \, A \in \mathscr T \] Proof Recall that for $ A \in \mathscr T $, the conditional probability $ \P(Y \in A \mid X) $ is itself a random variable, and is measurable with respect to $ \sigma(X) $. That is, $ \P(Y \in A \mid X) = P(X, A) $ for some measurable function $x \mapsto P(x, A) $ from $ S $ to $ [0, 1] $. Then, by definition, $ \P(Y \in A \mid X = x) = P(x, A) $. Trivially, of course, $ A \mapsto P(x, A) $ is a probability measure on $ (T, \mathscr T) $ for $ x \in S $. The operators associated with this kernel have natural interpretations. Let $ P $ be the conditional probability kernel of $ Y $ given $ X $. - If $ f: T \to \R $ is measurable, then $ Pf(x) = \E[f(Y) \mid X = x] $ for $ x \in S $ (assuming as usual that the expected value exists). - If $ \mu $ is the probability distribution of $ X $ then $ \mu P $ is the probability distribution of $ Y $. Proof These are basic results that we have already studied, dressed up in new notation. - Since $ A \mapsto P(x, A) $ is the conditional distribution of $ Y $ given $ X = x $, \[ \E[f(Y) \mid X = x] = \int_S P(x, dy) f(y) = P f(x) \] - Let $ A \in \mathscr T $. Conditioning on $ X $ gives \[ \P(Y \in A) = \E[\P(Y \in A \mid X)] = \int_S \mu(dx) P(Y \in A \mid X = x) = \int_S \mu(dx) P(x, A) = \mu P(A) \] As in the general discussion above, the measurable spaces $ (S, \mathscr S) $ and $ (T, \mathscr T) $ are usually measure spaces with natural measures attached. So the conditional probability distributions are often given via conditional probability density functions, which then play the role of kernel functions. The next two exercises give examples. Suppose that $ X $ and $ Y $ are random variables for an experiment, taking values in $ \R $. For $ x \in \R $, the conditional distribution of $ Y $ given $ X = x $ is normal with mean $ x $ and standard deviation 1. Use the notation and operations of this section for the following computations: - Give the kernel function for the conditional distribution of $ Y $ given $X$. - Find $ \E\left(Y^2 \bigm\| X = x\right) $. - Suppose that $ X $ has the standard normal distribution. Find the probability density function of $ Y $. Answer - The kernel function (with respect to Lebesgue measure, of course) is \[ p(x, y) = \frac{1}{\sqrt{2 \pi}} e^{-\frac{1}{2} (y - x)^2}, \quad x, \, y \in \R \] - Let $ g(y) = y^2 $ for $ y \in \R $. Then $ E\left(Y^2 \bigm\| X = x\right) = P g(x) = 1 + x^2$ for $ x \in \R $ - The standard normal PDF $ f $ is given $ f(x) = \frac{1}{\sqrt{2 \pi}} e^{-x^2/2} $ for $ x \in \R $. Thus $ Y $ has PDF $ f P $. \[ f P(y) \int_{-\infty}^\infty f(x) p(x, y) dx = \frac{1}{2 \sqrt{\pi}} e^{-\frac{1}{4} y^2}, \quad y \in \R\] This is the PDF of the normal distribution with mean 0 and variance 2. Suppose that $ X $ and $ Y $ are random variables for an experiment, with $ X $ taking values in $ \{a, b, c\} $ and $ Y $ taking values in $ \{1, 2, 3, 4\} $. The kernel function of $ Y $ given $ X $ is as follows: $ P(a, y) = 1/4 $, $ P(b, y) = y / 10 $, and $ P(c, y) = y^2/30 $, each for $ y \in \{1, 2, 3, 4\} $. - Give the kernel $ P $ in matrix form and verify that it is a probability kernel. - Find $ f P $ where $ f(a) = f(b) = f(c) = 1/3 $. The result is the density function of $ Y $ given that $ X $ is uniformly distributed. - Find $ P g $ where $ g(y) = y $ for $ y \in \{1, 2, 3, 4\} $. The resulting function is $ \E(Y \mid X = x) $ for $ x \in \{a, b, c\} $. Answer - $ P $ is given in matrix form below. Note that the row sums are 1. \[ P = \left[\begin{matrix} \frac{1}{4} & \frac{1}{4} & \frac{1}{4} & \frac{1}{4} \\ \frac{1}{10} & \frac{2}{10} & \frac{3}{10} & \frac{4}{10} \\ \frac{1}{30} & \frac{4}{30} & \frac{9}{30} & \frac{16}{30} \end{matrix} \right]\] - In matrix form, $ f = \left[\begin{matrix} \frac{1}{3} & \frac{1}{3} & \frac{1}{3} \end{matrix} \right]$ and $f P = \left[\begin{matrix} \frac{23}{180} & \frac{35}{180} & \frac{51}{180} & \frac{71}{180} \end{matrix} \right]$. - In matrix form, \[ g = \left[\begin{matrix} 1 \\ 2 \\ 3 \\ 4 \end{matrix} \right], \quad P g = \left[\begin{matrix} \frac{5}{2} \\ 3 \\ \frac{10}{3} \end{matrix} \right]\] Parametric Distributions A parametric probability distribution also defines a probability kernel in a natural way, with the parameter playing the role of the kernel variable, and the distribution playing the role of the measure. Such distributions are usually defined in terms of a parametric density function which then defines a kernel function, again with the parameter playing the role of the first argument and the variable the role of the second argument. If the parameter is thought of as a given value of another random variable, as in Bayesian analysis, then there is considerable overlap with the previous subsection. In most cases, (and in particular in the examples below), the spaces involved are either discrete or Euclidean, as described in (1) . Consider the parametric family of exponential distributions. Let $ f $ denote the identity function on $ (0, \infty) $. - Give the probability density function as a probability kernel function $ p $ on $ (0, \infty) $. - Find $ P f $. - Find $ f P $. - Find $ p^2 $, the kernel function corresponding to the product kernel $ P^2 $. Answer - $ p(r, x) = r e^{-r x} $ for $ r, \, x \in (0, \infty) $. - For $ r \in (0, \infty) $, \[ P f(r) = \int_0^\infty p(r, x) f(x) \, dx = \int_0^\infty x r e^{-r x} dx = \frac{1}{r} \] This is the mean of the exponential distribution. - For $ x \in (0, \infty) $, \[ f P(x) = \int_0^\infty f(r) p(r, x) \, dr = \int_0^\infty r^2 e^{-r x} dr = \frac{2}{x^3} \] - For $ r, \, y \in (0, \infty) $, \[ p^2(r, y) = \int_0^\infty p(r, x) p(x, y) \, dx = \int_0^\infty = \int_0^\infty r x e^{-(r + y) x} dx = \frac{r}{(r + y)^2} \] Consider the parametric family of Poisson distributions. Let $f $ be the identity function on $\N $ and let $ g $ be the identity function on $ (0, \infty) $. - Give the probability density function $ p $ as a probability kernel function from $ (0, \infty) $ to $ \N $. - Show that $ P f = g $. - Show that $ g P = f $. Answer - $ p(r, n) = e^{-r} \frac{r^n}{n!} $ for $ r \in (0, \infty) $ and $ n \in \N $. - For $ r \in (0, \infty) $, $ P f(r) $ is the mean of the Poisson distribution with parameter $ r $: \[ P f(r) = \sum_{n=0}^\infty p(r, n) f(n) = \sum_{n=0}^\infty n e^{-r} \frac{r^n}{n!} = r \] - For $ n \in \N $, \[ g P(n) = \int_0^\infty g(r) p(r, n) \, dr = \int_0^\infty e^{-r} \frac{r^{n+1}}{n!} dr = n \] Clearly the Poisson distribution has some very special and elegant properties. The next family of distributions also has some very special properties. Compare this exercise with the exercise (30) . Consider the family of normal distributions, parameterized by the mean and with variance 1. - Give the probability density function as a probability kernel function $ p $ on $ \R $. - Show that $ p $ is symmetric. - Let $ f $ be the identity function on $ \R $. - For $ n \in \N $, find $ p^n $ the kernel function for the operator $ P^n $. Answer - For $ \mu, \, x \in \R $, \[ p(\mu, x) = \frac{1}{\sqrt{2 \pi}} e^{-\frac{1}{2}(x - \mu)^2} \] That is, $ x \mapsto p(x, \mu) $ is the normal probability density function with mean $ \mu $ and variance 1. - Note that $ p(\mu, x) = p(x, \mu) $ for $ \mu, \, x \in \R $. So $ \mu \mapsto p(\mu, x) $ is the normal probability density function with mean $ x $ and variance 1. - Since $ f(x) = x $ for $ x \in \R $, this follows from the previous two parts: $ P f(\mu) = \mu $ for $ \mu \in \R $ and $ f P(x) = x $ for $ x \in \R $ - For $ \mu, \, y \in \R $, \[ p^2(\mu, x) = \int_{-\infty}^\infty p(\mu, t) p(t, y) \, dt = \frac{1}{\sqrt{4 \pi}} e^{-\frac{1}{4}(x - \mu)^2} \] so that $ x \mapsto p^2(\mu, x) $ is the normal PDF with mean $ \mu $ and variance 2. By induction, \[ p^n(\mu, x) = \frac{1}{\sqrt{2 \pi n}} e^{-\frac{1}{2 n}(x - \mu)^2} \] for $ n \in \N_+ $ and $ \mu, \, x \in \R $. Thus $ x \mapsto p^n(\mu, x) $ is the normal PDF with mean $ \mu $ and variance $ n $. For each of the following special distributions, express the probability density function as a probability kernel function. Be sure to specify the parameter spaces. - The general normal distribution on $ \R $. - The beta distribution on $ (0, 1) $. - The negative binomial distribution on $ \N $. Answer - The normal distribution with mean $ \mu $ and standard deviation $ \sigma $ defines a kernel function $ p $ from $ \R \times (0, \infty) $ to $ \R $ given by \[ p[(\mu, \sigma), x] = \frac{1}{\sqrt{2 \pi} \sigma} \exp\left[-\left(\frac{x - \mu}{\sigma}\right)^2\right] \] - The beta distribution with left parameter $ a $ and right parameter $ b $ defines a kernel function $ p $ from $ (0, \infty)^2 $ to $ (0, 1) $ given by \[ p[(a, b), x] = \frac{1}{B(a, b)} x^{a - 1} y^{b - 1} \] where $ B $ is the beta function. - The negative binomial distribution with stopping parameter $ k $ and success parameter $ \alpha $ defines a kernel function $ p $ from $ (0, \infty) \times (0, 1) $ to $ \N $ given by \[ p[(n, \alpha), k] = \binom{n + k - 1}{n} \alpha^k (1 - \alpha)^n \]	11,120	common-pile/libretexts_filtered	https://stats.libretexts.org/Bookshelves/Probability_Theory/Probability_Mathematical_Statistics_and_Stochastic_Processes_(Siegrist)/04%3A_Expected_Value/4.13%3A_Kernels_and_Operators	libretexts	libretexts-0000.json.gz:38010	https://stats.libretexts.org/Bookshelves/Probability_Theory/Probability_Mathematical_Statistics_and_Stochastic_Processes_(Siegrist)/04%3A_Expected_Value/4.13%3A_Kernels_and_Operators
2jjzFIxbyEfGduTu	6.3: Effective Reading Strategies	Allowing Adequate Time for Reading You should determine the reading requirements and expectations for every class very early in the semester. You also need to understand why you are reading the particular text you are assigned. Do you need to read closely for minute details that determine cause and effect? Or is your instructor asking you to skim several sources so you become more familiar with the topic? Knowing this reasoning will help you decide your timing, what notes to take, and how best to undertake the reading assignment. Figure 6.3: If you plan to make time for reading while you commute, remember that unexpected events like delays and cancellations could impact your concentration. Depending on the makeup of your schedule, you may end up reading both primary sources—such as legal documents, historic letters, or diaries—as well as textbooks, articles, and secondary sources, such as summaries or argumentative essays that use primary sources to stake a claim. You may also need to read current journalistic texts to stay current in local or global affairs. A realistic approach to scheduling your time to allow you to read and review all the reading you have for the semester will help you accomplish what can sometimes seem like an overwhelming task. When you allow adequate time in your hectic schedule for reading, you are investing in your own success. Reading isn’t a magic pill, but it may seem like it when you consider all the benefits people reap from this ordinary practice. Famous successful people throughout history have been voracious readers. In fact, former U.S. president Harry Truman once said, “Not all readers are leaders, but all leaders are readers.” Writer of the U.S. Declaration of Independence, inventor, and also former U.S. president Thomas Jefferson claimed “I cannot live without books” at a time when keeping and reading books was an expensive pastime. Knowing what it meant to be kept from the joys of reading, 19th-century abolitionist Frederick Douglass said, “Once you learn to read, you will be forever free.” And finally, George R. R. Martin, the prolific author of the wildly successful Game of Thrones empire, declared, “A reader lives a thousand lives before he dies . . . The man who never reads lives only one.” You can make time for reading in a number of ways that include determining your usual reading pace and speed, scheduling active reading sessions, and practicing recursive reading strategies. Determining Reading Speed and Pacing To determine your reading speed, select a section of text—passages in a textbook or pages in a novel. Time yourself reading that material for exactly 5 minutes, and note how much reading you accomplished in those 5 minutes. Multiply the amount of reading you accomplished in 5 minutes by 12 to determine your average reading pace (5 times 12 equals the 60 minutes of an hour). Of course, your reading pace will be different and take longer if you are taking notes while you read, but this calculation of reading pace gives you a good way to estimate your reading speed that you can adapt to other forms of reading. Example Reading Times \| Example Reading Times \| \| Reader \| Pages Read in 5 Minutes \| Pages per Hour \| Approximate Hours to Read 500 Pages \| \| Marta \| 4 \| 48 \| 10 hours, 30 minutes \| \| Jordi \| 3 \| 36 \| 13 hours \| \| Estevan \| 5 \| 60 \| 8 hours, 20 minutes \| So, for instance, if Marta was able to read 4 pages of a dense novel for her English class in 5 minutes, she should be able to read about 48 pages in one hour. Knowing this, Marta can accurately determine how much time she needs to devote to finishing the novel within a set amount of time, instead of just guessing. If the novel Marta is reading is 497 pages, then Marta would take the total page count (497) and divide that by her hourly reading rate (48 pages/hour) to determine that she needs about 10 to 11 hours overall. To finish the novel spread out over two weeks, Marta needs to read a little under an hour a day to accomplish this goal. Calculating your reading rate in this manner does not take into account days where you’re too distracted and you have to reread passages or days when you just aren’t in the mood to read. And your reading rate will likely vary depending on how dense the content you’re reading is (e.g., a complex textbook vs. a comic book). Your pace may slow down somewhat if you are not very interested in what the text is about. What this method will help you do is be realistic about your reading time as opposed to waging a guess based on nothing and then becoming worried when you have far more reading to finish than the time available. Scheduling Set Times for Active Reading Active reading takes longer than reading through passages without stopping. You may not need to read your latest sci-fi series actively while you’re lounging on the beach, but many other reading situations demand more attention from you. Active reading is particularly important for college courses. Plan to spend at least twice as long to read actively than to read passages without taking notes or otherwise marking select elements of the text. To determine the time you need for active reading, use the same calculations you use to determine your traditional reading speed and double it. Remember that you need to determine your reading pace for all the classes you have in a particular semester and multiply your speed by the number of classes you have that require different types of reading. Reading Times \| Example Active Reading Times \| \| Reader \| Pages Read in 5 Minutes \| Pages per Hour \| Approximate Hours to Read 500 Pages \| Approximate Hours to Actively Read 500 Pages \| \| Marta \| 4 \| 48 \| 10 hours, 30 minutes \| 21 hours \| \| Jordi \| 3 \| 36 \| 13 hours \| 26 hours \| \| Estevan \| 5 \| 60 \| 8 hours, 20 minutes \| 16 hours, 40 minutes \| Practicing Recursive Reading Strategies One fact about reading for college courses that may become frustrating is that, in a way, it never ends. For all the reading you do, you end up doing even more rereading. It may be the same content, but you may be reading the passage more than once to detect the emphasis the writer places on one aspect of the topic or how frequently the writer dismisses a significant counterargument. This rereading is called recursive reading. For most of what you read at the college level, you are trying to make sense of the text for a specific purpose—not just because the topic interests or entertains you. You need your full attention to decipher everything that’s going on in complex reading material—and you even need to be considering what the writer of the piece may not be including and why. This is why reading for comprehension is recursive. Specifically, this boils down to seeing reading not as a formula but as a process that is far more circular than linear. You may read a selection from beginning to end, which is an excellent starting point, but for comprehension, you’ll need to go back and reread passages to determine meaning and make connections between the reading and the bigger learning environment that led you to the selection—that may be a single course or a program in your college, or it may be the larger discipline, such as all biologists or the community of scholars studying beach erosion. People often say writing is rewriting. For college courses, reading is rereading. Strong readers engage in numerous steps, sometimes combining more than one step simultaneously, but knowing the steps nonetheless. They include, not always in this order: - bringing any prior knowledge about the topic to the reading session, - asking yourself pertinent questions, both orally and in writing, about the content you are reading, - inferring and/or implying information from what you read, - learning unfamiliar discipline-specific terms, - evaluating what you are reading, and eventually, - applying what you’re reading to other learning and life situations you encounter. Let’s break these steps into manageable chunks, because you are actually doing quite a lot when you read. Figure 6.4: The six elements of recursive reading should be considered as a circular, not linear, process. Asking Questions Humans are naturally curious beings. As you read actively, you should be asking questions about the topic you are reading. Don’t just say the questions in your mind; write them down. You may ask: Why is this topic important? What is the relevance of this topic currently? Was this topic important a long time ago but irrelevant now? Why did my professor assign this reading? You need a place where you can actually write down these questions; a separate page in your notes is a good place to begin. If you are taking notes on your computer, start a new document and write down the questions. Leave some room to answer the questions when you begin and again after you read. Inferring and Implying When you read, you can take the information on the page and infer , or conclude responses to related challenges from evidence or from your own reasoning. A student will likely be able to infer what material the professor will include on an exam by taking good notes throughout the classes leading up to the test. Writers may imply information without directly stating a fact for a variety of reasons. Sometimes a writer may not want to come out explicitly and state a bias, but may imply or hint at his or her preference for one political party or another. You have to read carefully to find implications because they are indirect, but watching for them will help you comprehend the whole meaning of a passage. Learning Vocabulary Vocabulary specific to certain disciplines helps practitioners in that field engage and communicate with each other. Few people beyond undertakers and archeologists likely use the term sarcophagus in everyday communications, but for those disciplines, it is a meaningful distinction. Looking at the example, you can use context clues to figure out the meaning of the term sarcophagus because it is something undertakers and/or archeologists would recognize. At the very least, you can guess that it has something to do with death. As a potential professional in the field you’re studying, you need to know the lingo. You may already have a system in place to learn discipline-specific vocabulary, so use what you know works for you. Two strong strategies are to look up words in a dictionary (online or hard copy) to ensure you have the exact meaning for your discipline and to keep a dedicated list of words you see often in your reading. You can list the words with a short definition so you have a quick reference guide to help you learn the vocabulary. Evaluating Intelligent people always question and evaluate. This doesn’t mean they don’t trust others; they just need verification of facts to understand a topic well. It doesn’t make sense to learn incomplete or incorrect information about a subject just because you didn’t take the time to evaluate all the sources at your disposal. When early explorers were afraid to sail the world for fear of falling off the edge, they weren’t stupid; they just didn’t have all the necessary data to evaluate the situation. When you evaluate a text, you are seeking to understand the presented topic. Depending on how long the text is, you will perform a number of steps and repeat many of these steps to evaluate all the elements the author presents. When you evaluate a text, you need to do the following: - Scan the title and all headings. - Read through the entire passage fully. - Question what main point the author is making. - Decide who the audience is. - Identify what evidence/support the author uses. - Consider if the author presents a balanced perspective on the main point. - Recognize if the author introduced any biases in the text. When you go through a text looking for each of these elements, you need to go beyond just answering the surface question; for instance, the audience may be a specific field of scientists, but could anyone else understand the text with some explanation? Why would that be important? Analysis Question Think of an article you need to read for a class. Take the steps above on how to evaluate a text, and apply the steps to the article. When you accomplish the task in each step, ask yourself and take notes to answer the question: Why is this important? For example, when you read the title, does that give you any additional information that will help you comprehend the text? If the text were written for a different audience, what might the author need to change to accommodate that group? How does an author’s bias distort an argument? This deep evaluation allows you to fully understand the main ideas and place the text in context with other material on the same subject, with current events, and within the discipline. Applying When you learn something new, it always connects to other knowledge you already have. One challenge we have is applying new information. It may be interesting to know the distance to the moon, but how do we apply it to something we need to do? If your biology instructor asked you to list several challenges of colonizing Mars and you do not know much about that planet’s exploration, you may be able to use your knowledge of how far Earth is from the moon to apply it to the new task. You may have to read several other texts in addition to reading graphs and charts to find this information. That was the challenge the early space explorers faced along with myriad unknowns before space travel was a more regular occurrence. They had to take what they already knew and could study and read about and apply it to an unknown situation. These explorers wrote down their challenges, failures, and successes, and now scientists read those texts as a part of the ever-growing body of text about space travel. Application is a sophisticated level of thinking that helps turn theory into practice and challenges into successes. Preparing to Read for Specific Disciplines in College Different disciplines in college may have specific expectations, but you can depend on all subjects asking you to read to some degree. In this college reading requirement, you can succeed by learning to read actively, researching the topic and author, and recognizing how your own preconceived notions affect your reading. Reading for college isn’t the same as reading for pleasure or even just reading to learn something on your own because you are casually interested. In college courses, your instructor may ask you to read articles, chapters, books, or primary sources (those original documents about which we write and study, such as letters between historic figures or the Declaration of Independence). Your instructor may want you to have a general background on a topic before you dive into that subject in class, so that you know the history of a topic, can start thinking about it, and can engage in a class discussion with more than a passing knowledge of the issue. If you are about to participate in an in-depth six-week consideration of the U.S. Constitution but have never read it or anything written about it, you will have a hard time looking at anything in detail or understanding how and why it is significant. As you can imagine, a great deal has been written about the Constitution by scholars and citizens since the late 1700s when it was first put to paper (that’s how they did it then). While the actual document isn’t that long (about 12–15 pages depending on how it is presented), learning the details on how it came about, who was involved, and why it was and still is a significant document would take a considerable amount of time to read and digest. So, how do you do it all? Especially when you may have an instructor who drops hints that you may also love to read a historic novel covering the same time period . . . in your spare time , not required, of course! It can be daunting, especially if you are taking more than one course that has time-consuming reading lists. With a few strategic techniques, you can manage it all, but know that you must have a plan and schedule your required reading so you are also able to pick up that recommended historic novel—it may give you an entirely new perspective on the issue. Strategies for Reading in College Disciplines No universal law exists for how much reading instructors and institutions expect college students to undertake for various disciplines. Suffice it to say, it’s a LOT. For most students, it is the volume of reading that catches them most off guard when they begin their college careers. A full course load might require 10–15 hours of reading per week, some of that covering content that will be more difficult than the reading for other courses. You cannot possibly read word-for-word every single document you need to read for all your classes. That doesn’t mean you give up or decide to only read for your favorite classes or concoct a scheme to read 17 percent for each class and see how that works for you. You need to learn to skim, annotate, and take notes. All of these techniques will help you comprehend more of what you read, which is why we read in the first place. We’ll talk more later about annotating and notetaking, but for now consider what you know about skimming as opposed to active reading. Skimming Skimming is not just glancing over the words on a page (or screen) to see if any of it sticks. Effective skimming allows you to take in the major points of a passage without the need for a time-consuming reading session that involves your active use of notations and annotations. Often you will need to engage in that painstaking level of active reading, but skimming is the first step—not an alternative to deep reading. The fact remains that neither do you need to read everything nor could you possibly accomplish that given your limited time. So learn this valuable skill of skimming as an accompaniment to your overall study tool kit, and with practice and experience, you will fully understand how valuable it is. When you skim, look for guides to your understanding: headings, definitions, pull quotes, tables, and context clues. Textbooks are often helpful for skimming—they may already have made some of these skimming guides in bold or a different color, and chapters often follow a predictable outline. Some even provide an overview and summary for sections or chapters. Use whatever you can get, but don’t stop there. In textbooks that have some reading guides, or especially in text that does not, look for introductory words such as First or The purpose of this article . . . or summary words such as In conclusion . . . or Finally . These guides will help you read only those sentences or paragraphs that will give you the overall meaning or gist of a passage or book. Now move to the meat of the passage. You want to take in the reading as a whole. For a book, look at the titles of each chapter if available. Read each chapter’s introductory paragraph and determine why the writer chose this particular order. Depending on what you’re reading, the chapters may be only informational, but often you’re looking for a specific argument. What position is the writer claiming? What support, counterarguments, and conclusions is the writer presenting? Don’t think of skimming as a way to buzz through a boring reading assignment. It is a skill you should master so you can engage, at various levels, with all the reading you need to accomplish in college. End your skimming session with a few notes—terms to look up, questions you still have, and an overall summary. And recognize that you likely will return to that book or article for a more thorough reading if the material is useful. Active Reading Strategies Active reading differs significantly from skimming or reading for pleasure. You can think of active reading as a sort of conversation between you and the text (maybe between you and the author, but you don’t want to get the author’s personality too involved in this metaphor because that may skew your engagement with the text). When you sit down to determine what your different classes expect you to read and you create a reading schedule to ensure you complete all the reading, think about when you should read the material strategically, not just how to get it all done . You should read textbook chapters and other reading assignments before you go into a lecture about that information. Don’t wait to see how the lecture goes before you read the material, or you may not understand the information in the lecture. Reading before class helps you put ideas together between your reading and the information you hear and discuss in class. Different disciplines naturally have different types of texts, and you need to take this into account when you schedule your time for reading class material. For example, you may look at a poem for your world literature class and assume that it will not take you long to read because it is relatively short compared to the dense textbook you have for your economics class. But reading and understanding a poem can take a considerable amount of time when you realize you may need to stop numerous times to review the separate word meanings and how the words form images and connections throughout the poem. The SQ3R Reading Strategy You may have heard of the SQ3R method for active reading in your early education. This valuable technique is perfect for college reading. The title stands for S urvey, Q uestion, R ead, R ecite, R eview, and you can use the steps on virtually any assigned passage. Designed by Francis Pleasant Robinson in his 1961 book Effective Study, the active reading strategy gives readers a systematic way to work through any reading material. Survey is similar to skimming. You look for clues to meaning by reading the titles, headings, introductions, summary, captions for graphics, and keywords. You can survey almost anything connected to the reading selection, including the copyright information, the date of the journal article, or the names and qualifications of the author(s). In this step, you decide what the general meaning is for the reading selection. Question is your creation of questions to seek the main ideas, support, examples, and conclusions of the reading selection. Ask yourself these questions separately. Try to create valid questions about what you are about to read that have come into your mind as you engaged in the Survey step. Try turning the headings of the sections in the chapter into questions. Read is when you actually read the passage. Try to find the answers to questions you developed in the previous step. Decide how much you are reading in chunks, either by paragraph for more complex readings or by section or even by an entire chapter. When you finish reading the selection, stop to make notes. Answer the questions by writing a note in the margin or other white space of the text. You may also carefully underline or highlight text in addition to your notes. Use caution here that you don’t try to rush this step by haphazardly circling terms or the other extreme of underlining huge chunks of text. Don’t over-mark. You aren’t likely to remember what these cryptic marks mean later when you come back to use this active reading session to study. The text is the source of information—your marks and notes are just a way to organize and make sense of that information. Recite means to speak out loud. By reciting, you are engaging other senses to remember the material—you read it (visual) and you said it (auditory). Stop reading momentarily in the step to answer your questions or clarify confusing sentences or paragraphs. You can recite a summary of what the text means to you. If you are not in a place where you can verbalize, such as a library or classroom, you can accomplish this step adequately by saying it in your head; however, to get the biggest bang for your buck, try to find a place where you can speak aloud. You may even want to try explaining the content to a friend. Review is a recap. Go back over what you read and add more notes, ensuring you have captured the main points of the passage, identified the supporting evidence and examples, and understood the overall meaning. You may need to repeat some or all of the SQR3 steps during your review depending on the length and complexity of the material. Before you end your active reading session, write a short (no more than one page is optimal) summary of the text you read. Reading Primary and Secondary Sources Primary sources are original documents we study and from which we glean information; primary sources include letters, first editions of books, legal documents, and a variety of other texts. When scholars look at these documents to understand a period in history or a scientific challenge and then write about their findings, the scholar’s article is considered a secondary source. Readers have to keep several factors in mind when reading both primary and secondary sources. Primary sources may contain dated material we now know is inaccurate. It may contain personal beliefs and biases the original writer didn’t intent to be openly published, and it may even present fanciful or creative ideas that do not support current knowledge. Readers can still gain great insight from primary sources, but readers need to understand the context from which the writer of the primary source wrote the text. Likewise, secondary sources are inevitably another person’s perspective on the primary source, so a reader of secondary sources must also be aware of potential biases or preferences the secondary source writer inserts in the writing that may persuade an incautious reader to interpret the primary source in a particular manner. For example, if you were to read a secondary source that is examining the U.S. Declaration of Independence (the primary source), you would have a much clearer idea of how the secondary source scholar presented the information from the primary source if you also read the Declaration for yourself instead of trusting the other writer’s interpretation. Most scholars are honest in writing secondary sources, but you as a reader of the source are trusting the writer to present a balanced perspective of the primary source. When possible, you should attempt to read a primary source in conjunction with the secondary source. The Internet helps immensely with this practice. WHAT STUDENTS SAY - What is the most influential factor in how thoroughly you read the material for a given course? - How engaging the material is or how much I enjoy reading it. - Whether or not the course is part of my major. - Whether or not the instructor assesses knowledge from the reading (through quizzes, for example), or requires assignments based on the reading. - Whether or not knowledge or information from the reading is required to participate in lecture. - What best describes your reading approach for required texts/materials for your classes? - I read all of the assigned material. - I read most of the assigned material. - I skim the text and read the captions, examples, or summaries. - What best describes your notetaking style? - I use a systematic method such as the Cornell method or something similar. - I highlight or underline all the important information. - I create outlines and/or note-cards. - I use an app or program. - I write notes in my text (print or digital). - I don’t have a style. I just write down what seems important. - I don't take many notes. You can also take the anonymous What Students Say(opens in new window) surveys to add your voice to this textbook. Your responses will be included in updates. Students offered their views on these questions, and the results are displayed in the graphs below. What is the most influential factor in how thoroughly you read the material for a given course? Figure 6.5 What best describes your reading approach for required texts/materials for your classes? Figure 6.6 What best describes your notetaking style? Figure 6.7 Researching Topic and Author During your preview stage, sometimes called pre-reading, you can easily pick up on information from various sources that may help you understand the material you’re reading more fully or place it in context with other important works in the discipline. If your selection is a book, flip it over or turn to the back pages and look for an author’s biography or note from the author. See if the book itself contains any other information about the author or the subject matter. The main things you need to recall from your reading in college are the topics covered and how the information fits into the discipline. You can find these parts throughout the textbook chapter in the form of headings in larger and bold font, summary lists, and important quotations pulled out of the narrative. Use these features as you read to help you determine what the most important ideas are. Figure 6.8: Learning about the book you’re reading can provide good context and information. Look for an author’s biography and forward on the back cover or in the first few pages. (Credit: Mark Hillary / Flickr / Attribution 2.0 Generic (CC-BY 2.0)) Remember, many books use quotations about the book or author as testimonials in a marketing approach to sell more books, so these may not be the most reliable sources of unbiased opinions, but it’s a start. Sometimes you can find a list of other books the author has written near the front of a book. Do you recognize any of the other titles? Can you do an Internet search for the name of the book or author? Go beyond the search results that want you to buy the book and see if you can glean any other relevant information about the author or the reading selection. Beyond a standard Internet search, try the library article database. These are more relevant to academic disciplines and contain resources you typically will not find in a standard search engine. If you are unfamiliar with how to use the library database, ask a reference librarian on campus. They are often underused resources that can point you in the right direction. Understanding Your Own Preset Ideas on a Topic Laura really enjoys learning about environmental issues. She has read many books and watched numerous televised documentaries on this topic and actively seeks out additional information on the environment. While Laura’s interest can help her understand a new reading encounter about the environment, Laura also has to be aware that with this interest, she also brings forward her preset ideas and biases about the topic. Sometimes these prejudices against other ideas relate to religion or nationality or even just tradition. Without evidence, thinking the way we always have is not a good enough reason; evidence can change, and at the very least it needs honest review and assessment to determine its validity. Ironically, we may not want to learn new ideas because that may mean we would have to give up old ideas we have already mastered, which can be a daunting prospect. With every reading situation about the environment, Laura needs to remain open-minded about what she is about to read and pay careful attention if she begins to ignore certain parts of the text because of her preconceived notions. Learning new information can be very difficult if you balk at ideas that are different from what you’ve always thought. You may have to force yourself to listen to a different viewpoint multiple times to make sure you are not closing your mind to a viable solution your mindset does not currently allow. Analysis Question Can you think of times you have struggled reading college content for a course? Which of these strategies might have helped you understand the content? Why do you think those strategies would work?	7,122	common-pile/libretexts_filtered	https://med.libretexts.org/Courses/Bakersfield_College/Strategies_for_Success_in_a_Nursing_Program/06%3A_Reading_and_Notetaking/6.03%3A_Effective_Reading_Strategies	libretexts	libretexts-0000.json.gz:6521	https://med.libretexts.org/Courses/Bakersfield_College/Strategies_for_Success_in_a_Nursing_Program/06%3A_Reading_and_Notetaking/6.03%3A_Effective_Reading_Strategies
l17gtOfoZvme_qxe	Leadership and Management of Nursing Care	10.2 Basic Advocacy Concepts Advocacy The American Nurses Association (ANA) emphasizes that advocacy is fundamental to nursing practice in every setting. See Figure 10.1[1] for an illustration of advocacy. Advocacy is defined as the act or process of pleading for, supporting, or recommending a cause or course of action. Advocacy may be for individuals, groups, organizations, communities, society, or policy issues:[2] - Individual: The nurse educates health care consumers so they can consider actions, interventions, or choices related to their own personal beliefs, attitudes, and knowledge to achieve the desired outcome. In this way, the health care consumer learns self-management and decision-making.[3] - Interpersonal: The nurse empowers health care consumers by providing emotional support, assistance in obtaining resources, and necessary help through interactions with families and significant others in their social support network.[4] - Organization and Community: The nurse supports cultural and social transformation of organizations, communities, or populations. Registered nurses understand their obligation to help improve environmental and societal conditions related to health, wellness, and care of the health care consumer.[5] - Policy: The nurse promotes inclusion of the health care consumers’ voices into policy, legislation, and regulation about issues such as health care access, reduction of health care costs and financial burden, protection of the health care consumer, and environmental health, such as safe housing and clear water.[6] Advocacy at each of these levels will be further discussed in later sections of this chapter. Advocacy is one of the ANA’s Standards of Professional Performance. The Standards of Professional Nursing Practice are “authoritative statements of the actions and behaviors that all registered nurses, regardless of role, population, specialty, and setting, are expected to perform competently.”[7] See the following box to read the competencies associated with the ANA’s Advocacy Standard of Professional Practice.[8] Competencies of ANA’s Advocacy Standard of Professional Practice[9] - Champions the voice of the health care consumer. - Recommends appropriate levels of care, timely and appropriate transitions, and allocation of resources to optimize outcomes. - Promotes safe care of health care consumers, safe work environments, and sufficient resources. - Participates in health care initiatives on behalf of the health care consumer and the system(s) where nursing happens. - Demonstrates a willingness to address persistent, pervasive systemic issues. - Informs the political arena about the role of nurses and the vital components necessary for nurses and nursing to provide optimal care delivery. - Empowers all members of the health care team to include the health care consumer in care decisions, including limitation of treatment and end of life. - Embraces diversity, equity, inclusivity, health promotion, and health care for individuals of diverse geographic, cultural, ethnic, racial, gender, and spiritual backgrounds across the life span. - Develops policies that improve care delivery and access for underserved and vulnerable populations. - Promotes policies, regulations, and legislation at the local, state, and national level to improve health care access and delivery of health care. - Considers societal, political, economic, and cultural factors to address social determinants of health. - Role models advocacy behavior. - Addresses the urgent need for a diverse and inclusive workforce as a strategy to improve outcomes related to the social determinants of health and inequities in the health care system. - Advances policies, programs, and practices within the health care environment that maintain, sustain, and restore the environment and natural world. - Contributes to professional organizations. Reflective Questions - What Advocacy competencies have you already demonstrated during your nursing education? - What Advocacy competencies are you most interested in performing next? - What questions do you have about ANA’s Advocacy competencies? - “Advocacy_-_The_Noun_Project.svg” by OCHA Visual Information Unit is licensed under CC0 ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵ - American Nurses Association. (2021). Nursing: Scope and standards of practice (4th ed.). American Nurses Association. ↵	964	common-pile/pressbooks_filtered	https://pressbooks.txst.edu/nursinglm/chapter/10-2-basic-advocacy-concepts/	pressbooks	pressbooks-0000.json.gz:81266	https://pressbooks.txst.edu/nursinglm/chapter/10-2-basic-advocacy-concepts/
Xpqh8BmX9dSp0fz4	Nursing Skills - 2e	16.4 Learning Activities Learning Activities (Answers to “Learning Activities” can be found in the “Answer Key” at the end of the book. Answers to interactive activity elements will be provided within the elements as immediate feedback.) 1. You are caring for an elderly patient who is complaining of pain, severe nausea, and who has difficulty swallowing. In addition to intravenous medication administration, what route of medication delivery might be beneficial for this patient to achieve pain relief? Please provide rationale for your selection. 2. Which of the following transdermal medication administration actions are correct? (Select all that apply). - The nurse may apply heat to all medication patches to help aid absorption of the medication. - When placing a patch, the nurse should press the patch firmly to the skin to ensure adequate adherence. - Gloves are required for patch application and removal. - Transdermal patches may be placed directly into the trash. - Date and location of patch application should be promptly documented in the medication administration record (MAR). Test your clinical judgment with an NCLEX Next Generation-style question: Chapter 16, Assignment 1. Test your clinical judgment with an NCLEX Next Generation-style question: Chapter 16, Assignment 2.	257	common-pile/pressbooks_filtered	https://wtcs.pressbooks.pub/nursingskills/chapter/16-4-learning-activities/	pressbooks	pressbooks-0000.json.gz:84138	https://wtcs.pressbooks.pub/nursingskills/chapter/16-4-learning-activities/
aGTpbE8R9E0Y0lRJ	7.8: Direct person-to-person transmission of pathogens	7.8: Direct person-to-person transmission of pathogens selected template will load here This action is not available. A new infection begins when pathogens leave the body of their host – the infected individual in which the pathogens are multiplying – and enter a new host. They may be repelled by defense mechanisms (i.e. skin) in the new host, or they may survive and reproduce in sufficient numbers to cause an infectious disease. Transmission of pathogens can occur directly between people, or indirectly in the air, water or food, or via other animals to humans, or from sources in the environment. In this section we explore direct transmission. Figure $\PageIndex{1}$. Direct person-to-person transmission of infection. (a) Contagion and sexual transmission. (b) Mother-to-child transmission. Figure $\PageIndex{1}$ represents the three ways in which pathogens can be transmitted by direct person-to-person contact. They are:	180	common-pile/libretexts_filtered	https://med.libretexts.org/Courses/Chabot_College/Introduction_to_Health/07%3A_Infectious_Diseases_and_Sexually_Transmitted_Infections/7.08%3A_Direct_person-to-person_transmission_of_pathogens	libretexts	libretexts-0000.json.gz:28601	https://med.libretexts.org/Courses/Chabot_College/Introduction_to_Health/07%3A_Infectious_Diseases_and_Sexually_Transmitted_Infections/7.08%3A_Direct_person-to-person_transmission_of_pathogens
-X9k-K5unt-Xp4GP	2.5: The Ratification of the Constitution	2.5: The Ratification of the Constitution - - Last updated - Save as PDF Learning Objectives By the end of this section, you will be able to: - Identify the steps required to ratify the Constitution - Describe arguments the framers raised in support of a strong national government and counterpoints raised by the Anti-Federalists On September 17, 1787, the delegates to the Constitutional Convention in Philadelphia voted to approve the document they had drafted over the course of many months. Some did not support it, but the majority did. Before it could become the law of the land, however, the Constitution faced another hurdle. It had to be ratified by the states. The Ratification Process Article VII, the final article of the Constitution, required that before the Constitution could become law and a new government could form, the document had to be ratified by nine of the thirteen states. Eleven days after the delegates at the Philadelphia convention approved it, copies of the Constitution were sent to each of the states, which were to hold ratifying conventions to either accept or reject it. This approach to ratification was an unusual one. Since the authority inherent in the Articles of Confederation and the Confederation Congress had rested on the consent of the states, changes to the nation’s government should also have been ratified by the state legislatures. Instead, by calling upon state legislatures to hold ratification conventions to approve the Constitution, the framers avoided asking the legislators to approve a document that would require them to give up a degree of their own power. The men attending the ratification conventions would be delegates elected by their neighbors to represent their interests. They were not being asked to relinquish their power; in fact, they were being asked to place limits upon the power of their state legislators, whom they may not have elected in the first place. Finally, because the new nation was to be a republic in which power was held by the people through their elected representatives, it was considered appropriate to leave the ultimate acceptance or rejection of the Constitution to the nation’s citizens. If convention delegates, who were chosen by popular vote, approved it, then the new government could rightly claim that it ruled with the consent of the people. The greatest sticking point when it came to ratification, as it had been at the Constitutional Convention itself, was the relative power of the state and federal governments. The framers of the Constitution believed that without the ability to maintain and command an army and navy, impose taxes, and force the states to comply with laws passed by Congress, the young nation would not survive for very long. But many people resisted increasing the powers of the national government at the expense of the states. Virginia’s Patrick Henry, for example, feared that the newly created office of president would place excessive power in the hands of one man. He also disapproved of the federal government’s new ability to tax its citizens. This right, Henry believed, should remain with the states. Other delegates, such as Edmund Randolph of Virginia, disapproved of the Constitution because it created a new federal judicial system. Their fear was that the federal courts would be too far away from where those who were tried lived. State courts were located closer to the homes of both plaintiffs and defendants, and it was believed that judges and juries in state courts could better understand the actions of those who appeared before them. In response to these fears, the federal government created federal courts in each of the states as well as in Maine, which was then part of Massachusetts, and Kentucky, which was part of Virginia. 11 Perhaps the greatest source of dissatisfaction with the Constitution was that it did not guarantee protection of individual liberties. State governments had given jury trials to residents charged with violating the law and allowed their residents to possess weapons for their protection. Some had practiced religious tolerance as well. The Constitution, however, did not contain reassurances that the federal government would do so. Although it provided for habeas corpus and prohibited both a religious test for holding office and granting noble titles, some citizens feared the loss of their traditional rights and the violation of their liberties. This led many of the Constitution’s opponents to call for a bill of rights and the refusal to ratify the document without one. The lack of a bill of rights was especially problematic in Virginia, as the Virginia Declaration of Rights was the most extensive rights-granting document among the states. The promise that a bill of rights would be drafted for the Constitution persuaded delegates in many states to support ratification. 12 Insider Perspective Thomas Jefferson on the Bill of Rights John Adams and Thomas Jefferson carried on a lively correspondence regarding the ratification of the Constitution. In the following excerpt (reproduced as written) from a letter dated March 15, 1789, after the Constitution had been ratified by nine states but before it had been approved by all thirteen, Jefferson reiterates his previously expressed concerns that a bill of rights to protect citizens’ freedoms was necessary and should be added to the Constitution: “In the arguments in favor of a declaration of rights, . . . I am happy to find that on the whole you are a friend to this amendment. The Declaration of rights is like all other human blessings alloyed with some inconveniences, and not accomplishing fully it’s object. But the good in this instance vastly overweighs the evil. . . . This instrument [the Constitution] forms us into one state as to certain objects, and gives us a legislative & executive body for these objects. It should therefore guard us against their abuses of power. . . . Experience proves the inefficacy of a bill of rights. True. But tho it is not absolutely efficacious under all circumstances, it is of great potency always, and rarely inefficacious. . . . There is a remarkeable difference between the . . . Inconveniences which attend a Declaration of rights, & those which attend the want of it. . . . The inconveniences of the want of a Declaration are permanent, afflicting & irreparable: they are in constant progression from bad to worse.” 13 What were some of the inconveniences of not having a bill of rights that Jefferson mentioned? Why did he decide in favor of having one? It was clear how some states would vote. Smaller states, like Delaware, favored the Constitution. Equal representation in the Senate would give them a degree of equality with the larger states, and a strong national government with an army at its command would be better able to defend them than their state militias could. Larger states, however, had significant power to lose. They did not believe they needed the federal government to defend them and disliked the prospect of having to provide tax money to support the new government. Thus, from the very beginning, the supporters of the Constitution feared that New York, Massachusetts, Pennsylvania, and Virginia would refuse to ratify it. That would mean all nine of the remaining states would have to, and Rhode Island, the smallest state, was unlikely to do so. It had not even sent delegates to the convention in Philadelphia. And even if it joined the other states in ratifying the document and the requisite nine votes were cast, the new nation would not be secure without its largest, wealthiest, and most populous states as members of the union. The Ratification Campaign On the question of ratification, citizens quickly separated into two groups: Federalists and Anti-Federalists. The Federalists supported it. They tended to be among the elite members of society—wealthy and well-educated landowners, businessmen, and former military commanders who believed a strong government would be better for both national defense and economic growth. A national currency, which the federal government had the power to create, would ease business transactions. The ability of the federal government to regulate trade and place tariffs on imports would protect merchants from foreign competition. Furthermore, the power to collect taxes would allow the national government to fund internal improvements like roads, which would also help businessmen. Support for the Federalists was especially strong in New England. Opponents of ratification were called Anti-Federalists. Anti-Federalists feared the power of the national government and believed state legislatures, with which they had more contact, could better protect their freedoms. Although some Anti-Federalists, like Patrick Henry, were wealthy, most distrusted the elite and believed a strong federal government would favor the rich over those of “the middling sort.” This was certainly the fear of Melancton Smith, a New York merchant and landowner, who believed that power should rest in the hands of small, landowning farmers of average wealth who “are more temperate, of better morals and less ambitious than the great.” 14 Even members of the social elite, like Henry, feared that the centralization of power would lead to the creation of a political aristocracy, to the detriment of state sovereignty and individual liberty. Related to these concerns were fears that the strong central government Federalists advocated for would levy taxes on farmers and planters, who lacked the hard currency needed to pay them. Many also believed Congress would impose tariffs on foreign imports that would make American agricultural products less welcome in Europe and in European colonies in the western hemisphere. For these reasons, Anti-Federalist sentiment was especially strong in the South. Some Anti-Federalists also believed that the large federal republic that the Constitution would create could not work as intended. Americans had long believed that virtue was necessary in a nation where people governed themselves (i.e., the ability to put self-interest and petty concerns aside for the good of the larger community). In small republics, similarities among members of the community would naturally lead them to the same positions and make it easier for those in power to understand the needs of their neighbors. In a larger republic, one that encompassed nearly the entire Eastern Seaboard and ran west to the Appalachian Mountains, people would lack such a strong commonality of interests. 15 Likewise, Anti-Federalists argued, the diversity of religion tolerated by the Constitution would prevent the formation of a political community with shared values and interests. The Constitution contained no provisions for government support of churches or of religious education, and Article VI explicitly forbade the use of religious tests to determine eligibility for public office. This caused many, like Henry Abbot of North Carolina, to fear that government would be placed in the hands of “pagans . . . and Mahometans [Muslims].” 16 It is difficult to determine how many people were Federalists and how many were Anti-Federalists in 1787. The Federalists won the day, but they may not have been in the majority. First, the Federalist position tended to win support among businessmen, large farmers, and, in the South, plantation owners. These people tended to live along the Eastern Seaboard. In 1787, most of the states were divided into voting districts in a manner that gave more votes to the eastern part of the state than to the western part. 17 Thus, in some states, like Virginia and South Carolina, small farmers who may have favored the Anti-Federalist position were unable to elect as many delegates to state ratification conventions as those who lived in the east. Small settlements may also have lacked the funds to send delegates to the convention. 18 In all the states, educated men authored pamphlets and published essays and cartoons arguing either for or against ratification (Figure 2.11). Although many writers supported each position, it is the Federalist essays that are now best known. The arguments these authors put forth, along with explicit guarantees that amendments would be added to protect individual liberties, helped to sway delegates to ratification conventions in many states. For obvious reasons, smaller, less populous states favored the Constitution and the protection of a strong federal government. As shown in Figure 2.12, Delaware and New Jersey ratified the document within a few months after it was sent to them for approval in 1787. Connecticut ratified it early in 1788. Some of the larger states, such as Pennsylvania and Massachusetts, also voted in favor of the new government. New Hampshire became the ninth state to ratify the Constitution in the summer of 1788. Although the Constitution went into effect following ratification by New Hampshire, four states still remained outside the newly formed union. Two were the wealthy, populous states of Virginia and New York. In Virginia, James Madison’s active support and the intercession of George Washington, who wrote letters to the convention, changed the minds of many. Some who had initially opposed the Constitution, such as Edmund Randolph, were persuaded that the creation of a strong union was necessary for the country’s survival and changed their position. Other Virginia delegates were swayed by the promise that a bill of rights similar to the Virginia Declaration of Rights would be added after the Constitution was ratified. On June 25, 1788, Virginia became the tenth state to grant its approval. The approval of New York was the last major hurdle. Facing considerable opposition to the Constitution in that state, Alexander Hamilton, James Madison, and John Jay wrote a series of essays, beginning in 1787, arguing for a strong federal government and support of the Constitution (Figure 2.13). Later compiled as The Federalist and now known as The Federalist Papers , these eighty-five essays were originally published in newspapers in New York and other states under the name of Publius, a supporter of the Roman Republic. The essays addressed a variety of issues that troubled citizens. For example, in Federalist No. 51, attributed to James Madison (Figure 2.14), the author assured readers they did not need to fear that the national government would grow too powerful. The federal system, in which power was divided between the national and state governments, and the division of authority within the federal government into separate branches would prevent any one part of the government from becoming too strong. Furthermore, tyranny could not arise in a government in which “the legislature necessarily predominates.” Finally, the desire of office holders in each branch of government to exercise the powers given to them, described as “personal motives,” would encourage them to limit any attempt by the other branches to overstep their authority. According to Madison, “Ambition must be made to counteract ambition.” Other essays countered different criticisms made of the Constitution and echoed the argument in favor of a strong national government. In Federalist No. 35, for example, Hamilton (Figure 2.14) argued that people’s interests could in fact be represented by men who were not their neighbors. Indeed, Hamilton asked rhetorically, would American citizens best be served by a representative “whose observation does not travel beyond the circle of his neighbors and his acquaintances” or by someone with more extensive knowledge of the world? To those who argued that a merchant and land-owning elite would come to dominate Congress, Hamilton countered that the majority of men currently sitting in New York’s state senate and assembly were landowners of moderate wealth and that artisans usually chose merchants, “their natural patron[s] and friend[s],” to represent them. An aristocracy would not arise, and if it did, its members would have been chosen by lesser men. Similarly, Jayreminded New Yorkers in Federalist No. 2 that union had been the goal of Americans since the time of the Revolution. A desire for union was natural among people of such “similar sentiments” who “were united to each other by the strongest ties,” and the government proposed by the Constitution was the best means of achieving that union. Objections that an elite group of wealthy and educated bankers, businessmen, and large landowners would come to dominate the nation’s politics were also addressed by Madison in Federalist No. 10. Americans need not fear the power of factions or special interests, he argued, for the republic was too big and the interests of its people too diverse to allow the development of large, powerful political parties. Likewise, elected representatives, who were expected to “possess the most attractive merit,” would protect the government from being controlled by “an unjust and interested [biased in favor of their own interests] majority.” For those who worried that the president might indeed grow too ambitious or king-like, Hamilton, in Federalist No. 68, provided assurance that placing the leadership of the country in the hands of one person was not dangerous. Electors from each state would select the president. Because these men would be members of a “transient” body called together only for the purpose of choosing the president and would meet in separate deliberations in each state, they would be free of corruption and beyond the influence of the “heats and ferments” of the voters. Indeed, Hamilton argued in Federalist No. 70, instead of being afraid that the president would become a tyrant, Americans should realize that it was easier to control one person than it was to control many. Furthermore, one person could also act with an “energy” that Congress did not possess. Making decisions alone, the president could decide what actions should be taken faster than could Congress, whose deliberations, because of its size, were necessarily slow. At times, the “decision, activity, secrecy, and dispatch” of the chief executive might be necessary. Link to Learning The Library of Congress has The Federalist Papers on their website. The Anti-Federalists also produced a body of writings, less extensive than The Federalists Papers , which argued against the ratification of the Constitution. However, these were not written by one small group of men as The Federalist Papers had been. A collection of the writings that are unofficially called The Anti-Federalist Papers is also available online. The Library of Congress has The Federalist Papers on their website. The Anti-Federalists also produced a body of writings, less extensive than The Federalists Papers , which argued against the ratification of the Constitution. However, these were not written by one small group of men as The Federalist Papers had been. A collection of the writings that are unofficially called The Anti-Federalist Papers is also available online. The arguments of the Federalists were persuasive, but whether they actually succeeded in changing the minds of New Yorkers is unclear. Once Virginia ratified the Constitution on June 25, 1788, New York realized that it had little choice but to do so as well. If it did not ratify the Constitution, it would be the last large state that had not joined the union. Thus, on July 26, 1788, the majority of delegates to New York’s ratification convention voted to accept the Constitution. A year later, North Carolina became the twelfth state to approve. Alone and realizing it could not hope to survive on its own, Rhode Island became the last state to ratify, nearly two years after New York had done so. Finding a Middle Ground Term Limits One of the objections raised to the Constitution’s new government was that it did not set term limits for members of Congress or the president. Those who opposed a strong central government argued that this failure could allow a handful of powerful men to gain control of the nation and rule it for as long as they wished. Although the framers did not anticipate the idea of career politicians, those who supported the Constitution argued that reelecting the president and reappointing senators by state legislatures would create a body of experienced men who could better guide the country through crises. A president who did not prove to be a good leader would be voted out of office instead of being reelected. In fact, presidents long followed George Washington’s example and limited themselves to two terms. Only in 1951, after Franklin Roosevelt had been elected four times, was the Twenty-Second Amendment passed to restrict the presidency to two terms. Are term limits a good idea? Should they have originally been included in the Constitution? Why or why not? Are there times when term limits might not be good?	4,369	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Bookshelves/Political_Science_and_Civics/American_Government_3e_(OpenStax)/02%3A_The_Constitution_and_Its_Origins/2.05%3A_The_Ratification_of_the_Constitution	libretexts	libretexts-0000.json.gz:10280	https://socialsci.libretexts.org/Bookshelves/Political_Science_and_Civics/American_Government_3e_(OpenStax)/02%3A_The_Constitution_and_Its_Origins/2.05%3A_The_Ratification_of_the_Constitution
LkyUY1v9jOkmS2S0	Canadian History: Pre-Confederation - 2nd Edition	Chapter 2. Indigenous Canada before Contact 2.1 Introduction When does the history of Canada begin? If we think of Canada as a political entity, then we will offer up one kind of answer (although, in all likelihood, we won’t agree at the outset on the answer). If we think of Canada as a space roughly defined by our current borders and as a stage on which humans perform, then the answer is necessarily going to take us as deeply into the past as we can go. Having taken on the question of how do we know what it is we think we know? in Chapter 1, this chapter tackles the challenge of pushing back the frontier of history. Generations of students learned that the moment of contact between Europeans and Indigenous peoples in the “Americas” marks the end of pre-history in this hemisphere and the beginning of the historical period. But that perspective has changed. Learning Objectives - Explain the various interpretations, scientific and religious, of the origins of Indigenous peoples in the New World. - Describe the political, cultural, and social differences between the major eras of the pre-contact peoples of Canada. - Describe the political, cultural, and social differences between the groups of the major regions of Canada. - Identify the great empires and confederacies of the pre-contact Americas. - Locate the many different peoples of what is now Canada and its borderlands. - Describe the different language groups, the different economic orders of the northlands, and their interconnectedness. - Argue critically against notions of “pan-Indianism” and speak to the advantages enjoyed by Indigenous societies in the absence of European contact. The first documented encounter between Indigenous peoples and Europeans. This is a movable date because first encounters occur in different regions at different times. The contact era for some Arctic peoples, for example, only began in the 20th century.	405	common-pile/pressbooks_filtered	https://opentextbc.ca/preconfederation2e/chapter/2-1-introduction/	pressbooks	pressbooks-0000.json.gz:39782	https://opentextbc.ca/preconfederation2e/chapter/2-1-introduction/
SwsF0pxUrKNKStLn	Blueprint for Success in College: Indispensable Study Skills and Time Management Strategies	Chapter 16: The Basics of Study Skills Dave Dillon and Phyllis Nissila “If you study to remember, you will forget, but, if you study to understand, you will remember.” – Unknown I often start this section of my class with a question: Why do some students earn good grades and others do not? Answers vary. Students with poor grades have said students with good grades are born book smart. Students with good grades answer that studying and hard work got them there. What do you think? Everyone likes to earn an A grade. Despite the stigma of being a “nerd,” it feels good to receive good grades. Take pride in your preparation, take pride in your studying, and take pride in your accomplishments. I have also noticed over the years with my classes that students know many things they need to do in order to achieve good grades – they just don’t always perform them. Be Prepared for Each Class Complete your assigned reading ahead of the deadline. Follow the syllabus so that you’ll have familiarity with what the instructor is speaking about. Bring your course syllabus, textbook, notebook and any handouts or other important information for each particular class along with a pen and a positive attitude. Become interested in what the instructor has to say. Be eager to learn. Sleep adequately the night before class and ensure you do not arrive to class on an empty stomach. Many courses, both in person and online, use digital platforms called Learning Management Systems (LMS). Examples of these are Canvas, Blackboard, and Moodle. It is important for students to check their e-mail regularly as well as Announcements or notifications from their instructor through the LMS. Attend Every Class Attending each and every class requires a lot of self-discipline and motivation. Doing so will help you remain engaged and involved in course topics, provide insight into what your instructor deems most important, allow you to submit work and receive your graded assignments and give you the opportunity to take quizzes or exams that cannot be made up. Missing class is a major factor in students dropping courses or receiving poor grades. In addition, students attempting to make up the work from missing class often find it overwhelming. It’s challenging to catch up if we get behind. Sit Front and Center Author’s Story Full disclosure: I loved to sit in the back of the classroom when I was in college. I felt more comfortable back there. I didn’t want to make eye contact with my instructor. I didn’t want to be called on. But I learned that if I wanted to give myself the best opportunity to see, hear, understand and learn, then I needed to sit in the front and center. And in order to make sure I sat in the front and center, I needed to arrive to my classes early. I instruct my students to “Sit wherever you want — sit where you are most comfortable.” But I also ask them that if they were to attend a concert for their favorite artist, where would they like to be? It’s always right in front of the stage, because the best experience is closest to the band. That’s why front-and-center tickets are the most expensive. There are some reasons sitting in the back works for some students. But you run the risk of sitting behind someone you cannot see over. And if you’re sitting in the back so that you can send text messages without being seen, work on something else or so that you can disengage (not pay attention without the instructor noticing), then you’re sitting in the back for the wrong reasons. Rather than hiding, you want to create the best learning environment, from seeing and hearing perspectives. Take Notes in Class Hermann Ebbinghaus, a German psychologist, scientifically studied how people forget in the late 1800’s. He is known for his experiments using himself as a subject and tested his memory learning nonsense syllables. One of his famous results, known as the forgetting curve, shows how much information is forgotten quickly after it is learned. Without reviewing, we will forget. Since we forget 42% of the information we take in after only 20 minutes (without review), it is imperative to take notes to remember. Take Notes When You Are Reading For the same reason as above, it is helpful to take notes while you are reading to maximize memorization. Sometimes called Active Reading, the goal is to stay focused on the material and to be able to refer back to notes made while reading to improve retention and study efficiency. Don’t make the mistake of expecting to remember everything you are reading. Taking notes when reading requires effort and energy. Be willing to do it and you’ll reap the benefits later. Find out what is available to you by checking your school’s website for campus resources or student services, or talk to a counselor about what resources may be helpful for you. Check to see where your campus has resources for Counseling, Tutoring, Writing assistance, a Library, Admissions and Records (or Registrar’s), Financial Aid, Health Center, Career Center, Disability Support Services, and other support services. Read and Retain Your Syllabus In addition to acting as a contract between the instructor and you, the syllabus is also often the source of information for faculty contact information, textbook information, classroom behavior expectations, attendance policy and course objectives. Some students make the mistake of stuffing the syllabus in their backpack when they receive it on the first day of class and never take a look at it again. Those who clearly read it, keep it for reference and review it frequently find themselves more prepared for class. If there is something in the syllabus you don’t understand, ask your instructor about it before class, after class or during their office hours. Place all of your assignments for all of your classes with their due dates in your calendar, planner, smart phone or whatever you use for organization. Successful students will also schedule when to start those assignments and have an idea of how long it will take to complete them. Complete All of Your Assignments There will be things that you are more interested in doing than your assignments and unexpected life happenings that will come up. Students who earn good grades have the motivation and discipline to complete all of their assignments. Have Someone Read Your Papers Before You Submit Them You might be surprised to learn how many students turn in papers with spelling, grammar and punctuation errors that could have been easily corrected by using a spellchecker program or having someone read your paper. Many schools offer writing centers or tutors who will read your paper and give feedback, make suggestions, and help shape ideas. Take advantage of these services if they are offered. Another strategy is to read your paper aloud to yourself. You may catch errors when you read aloud that you might not catch when reading your writing. Remember that it is always the students’ responsibility to have papers proofread, not someone else’s. Ask Questions Many students feel like they are the only one that has a question or the only one that doesn’t understand something in class. I encourage you to ask questions during class, especially if your instructor encourages them. If not, make the effort to ask your questions before or after class or during your instructors’ office hours. If you take a class offered online, I suggest asking a lot of questions via the preferred method your instructor recommends. Since the delivery method is different to what most students are used to, I believe it is natural for students in online courses to have more questions. Online students may ask questions to understand the material and to be able to successfully navigate through the course content. Inside information: I expect students to ask questions for both in person and online courses I teach. Complete All Assigned Reading at The Time It Is Assigned College courses have much more assigned reading than what most high school students are accustomed to, and it can take a while to become comfortable with the workload. Some students fall behind early in keeping up with the reading requirements and others fail to read it at all. You will be most prepared for your class and for learning if you complete the reading assigned before your class. Staying on top of your syllabus and class calendar will help you be aware of your reading assignment deadlines. There is a difference in assigned reading between high school and college. In high school, if a teacher gave a handout to read in class, students would often read it during class to prepare to participate in a class discussion. In college, more reading is assigned with the expectation it will be done outside of the classroom. It is a big adjustment students need to make in order to be successful. Study Groups It has been my observation that one of the recent generational differences is that students study less in groups than they used to. My advice for you is to study in the environment that works best for you, but ensure that you try a study group, especially if you are taking a class in a subject in which you are not strong. Study groups can allow for shared resources, new perspectives, answers for questions, faster learning, increased confidence, and increased motivation. EXERCISE 16-1 PART A: Study Area–Help Tran Create a plan for Tran, on how to organize a study area in her busy home where she lives with six members of her family. Tran is a first year college student from Vietnam. She has been in the U.S. with her family for three years and recently passed the English Language Learner classes at the topmost level, so now she looks forward to pursuing her degree in Business Management. She lives with six other family members, her mother, father, grandmother, and three younger siblings aged 14, 12, and 9. Their home is located right next door to the family restaurant. This makes it convenient for Tran and her parents to work their regular shifts and to fill in if one or the other is ill. Tran is also responsible at times to help her younger siblings with their homework and/or take them to school and other activities if her parents are busy. This usually occurs at peak times for customers in the restaurant. Her grandmother helps out when she can but arthritis flare-ups prevent her from working as much as she would like. Tran does have a small bedroom to herself, but it also sometimes serves as a storage room for restaurant supplies, mostly paper goods, so it can get crowded. She is anticipating setting up an effective homework/study area for what she knows will soon become more of an intensive course load. EXERCISE 16-2 PART B: Study Group–Help The Athletes Jeb, Andrew, and Nelson are first year students at the university on sports scholarships: Jeb for basketball, Andrew for tennis, and Nelson for track and field. They share an apartment near the college sports complex. They are all taking Math 95 this term and realize that forming a study group as their instructor encouraged everyone to do would really help them, too. One of the problems in getting a group going is that they are all big fans of ESPN and each one favors a different sport, so the television tends to be on long–and loud. They also enjoy trying out all the restaurants in this southern city which is famous for having the best barbecue joints in the nation. They have calculated that there are at least seven restaurants nearby they want to get to know. And then there are those campus parties on Friday and Saturday nights… Although the men are highly motivated to eventually finish their degrees in business, culinary arts, and economics, they could use some advice on how to form a useful study group–and how to stick with it, particularly before their sports programs kick into high gear. Review for Exams Preparation for an exam should begin on the first day of class, not when the exam is announced nor the night before an exam. Review your notes frequently to keep material fresh in your head. Schedule Time for Studying It’s easy to put off studying if it’s not something we schedule. Block specific times and days for studying. Put the times on your calendar. Stick to the schedule. Study In a Location and At a Time That Is Best for You Some students study best in the morning and some at night. Some excel at a coffee shop, and others at the library. The place and time in which students often study is usually the most convenient for them. Students often find these convenient places and times may also be full of distractions and thus are not good choices for them to study. It’s worth the effort to study at the time and place that will be most productive for you. For most students, it is best to turn off the cell phone and TV and to keep off the Internet (and social media) unless it directly relates to your work. Tips for Effective, Individual Study Spaces Most students more or less take what they can get when it comes to study areas. Schools usually offer a variety of nooks and crannies for students to hunker down and get their assignments done. The school library is a good (and quiet) place. Many common areas elsewhere on campus have tables, chairs, couches, and lounges to accommodate learners. But most students end up doing the majority of their out-of-class work at home. Home environments may be limited in terms of providing all of the recommended aspects of a good study space, but many of the recommendations can be either implemented or adapted from what a student has on hand or what can be improvised no matter what environment he or she is living in. Elements conducive to a more effective study/homework experience include such things as good lighting, ample supplies, comfortable seating, adequate space, and personalizing the study area to add a touch of inspiration and motivation. EXERCISE 16-3 PART A Describe your current study area at home–the good, the bad, the ugly. Be thorough. PART B List as many ways you think you can realistically improve, change, (or start over…) your study area. Remember, you might not have the advantage of a whole room, or even a corner of a room, but there are still some changes you can make to create a more effective study environment. Author’s Story I did most of my studying in college in my dorm room, at my house, outside if it was a nice day or at a coffee shop. However, if there was something I knew I absolutely had to get done – read a chapter, finish a paper or complete my preparation for an exam, I would head to one place: McHenry library. It was what I call my go-to place. I was able to concentrate at a higher level there. I was able to block out all other distractions and just focus on the task at hand. You may be thinking: why didn’t he study there all the time? Sometimes it wasn’t convenient. And sometimes it wasn’t necessary. I was able to become an expert on how well I needed to know something, and how much I could get done if I was at McHenry for a couple of hours. Note that I didn’t procrastinate and then try to cram everything in at McHenry. Rather I would place the finishing touches on what had already been studied or worked on. Don’t Do Anything Academically “Half-assed” Half-assed is defined as poorly or incompetently done. Think of it this way: You’ve made the decision to come to college. You’re investing time, energy and money into your commitment. Why would you want to half-ass it? Students who miss class, turn in work late or wait until the last minute are half-assing it. Make college a priority and do your best in all of your college work and preparation. Apply these basic principles and you will be giving yourself the best opportunity to achieve success. And I’ll let you in on a little secret: apply this to all aspects not just academics and you’ll find success in life! Licenses and Attributions: Content previously copyrighted, published in Blueprint for Success in College: Indispensable Study Skills and Time Management Strategies (by Dave Dillon), now licensed as CC-BY Attribution. CC licensed content, previously shared: How to Learn Like a Pro! Authored by Phyllis Nissila. Located at: https://openoregon.pressbooks.pub/collegereading/chapter/lesson-2-5-study-areas-for-individuals-and-groups/ License: CC BY: Attribution. Adaptions: Exercises for Study Groups and Tips for Effective, Individual Study Areas added from Lesson 2.5 Study Areas and Study Groups. “Cluttered desk” image by OpenClipart-Vectors is in the Public Domain, CC0	3,679	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/blueprint1/chapter/20-the-basics-of-study-skills/	pressbooks	pressbooks-0000.json.gz:32066	https://ecampusontario.pressbooks.pub/blueprint1/chapter/20-the-basics-of-study-skills/
irouWo3GJyZu5LTC	Nursing Skills	12.2 Gastrointestinal Basics Open Resources for Nursing (Open RN) It is important for the nurse to be aware of the underlying structures of the abdomen when completing a gastrointestinal or genitourinary assessment. See Figure 12.1[1] for an illustration of the gastrointestinal system and the bladder. See Figure 12.2[2] for an illustration of the male urinary system. Know the position of the organs within the abdominal cavity as you learn to auscultate, palpate, and percuss the abdomen. For a detailed overview of the gastrointestinal system, common GI disorders, and related GI medications, visit the “Gastrointestinal” chapter of the Open RN Nursing Pharmacology textbook. Specific sections of the chapter include the following: - GI System Review for additional review of the anatomy of the GI system - Antidiarrheals and Laxatives for more information about treating diarrhea and constipation - Antiemetics for more information about treating nausea and vomiting - Hyperacidity and Acid Controlling Medication for more information about treating acid reflux and gastric ulcers - “abdomen-intestine-large-small-1698565” by bodymybody is licensed under CC0 ↵ - “Urinary_System_(Male).png” by BruceBlaus is licenced under CC BY-SA 4.0 ↵	236	common-pile/pressbooks_filtered	https://opentextbooks.uregina.ca/nursingskills2/chapter/12-2-gastrointestinal-basics/	pressbooks	pressbooks-0000.json.gz:83870	https://opentextbooks.uregina.ca/nursingskills2/chapter/12-2-gastrointestinal-basics/
JNbazpxwOcW3ziB8	The modern architect, or, Every carpenter his own master : embracing plans, elevations, specifications, framing, etc., for private houses, classic dwellings, churches, &c., to which added the new system of stair-building / by Edward Shaw.	MODERN ARCHITECT. In presenting this work of Modem Architecture to the American public, the publishers aim exclusively to arrest the attention of every Mechanic deserving the name of Carpenter, and who may have a desire to become his own master. No labor, pains or expense, have been spared in the preparation of this treatise, to have the work fully adapted to meet the wants of those who wish to become acquainted with the science. To such we can say, in the opinion of good judges, the present work has jiot been excelled for minuteness of detail, and practical application to the wants of the practical man. We address ourselves and our work to the consideration of the Mechanic, the Master, and the Architect, as all have felt the need of a thorough knowledge of the rules and principles of the art. We have, therefore, introduced the Ancient and Modern foundation principles and systems of the Egyptian, Grecian, Corinthian, Doric, Ionic and Gothic modes of building — showing the different plans, elevations, decorations, specifications, estimates, framing, &c. We conclude with the observation, that a pure Architectural taste is a great gift, or attainment, for any man to be possessed of; and, if this science were more generally studied throughout the United States, we should be exempt from those architectural abortions which now so often disgrace our cities and villages. Boston, 1854. Note. In answer to many inquiries respecting my practical knowledge as a Carpenter and Joiner, I would say, that I served in that capacity twenty years, — fourteen of which as a contractor and builder, drawing all of my own plans and designs for private and public dwellings costing from five hundred to forty thousand dollars each ; since which time I hava <ppnt fifteen years in the theoretical practice and scienee of Architectural Drawing* and Plans, both ancient and modern. HISTORY AND PROGRESS OF ARCHITECTURE. At a very early period, as might be expected, architecture had made some progress; for we are informed by Holy Writ that Cain " builded a city, and called the name of the city after the name of his son, Enoch." * But we are wholly in the dark as to the perfection to which it had attained when that awful visitation of the Almighty, the universal deluge, obliterated almost every mark of previous habitation. The next mention of it is in the account of the building of the tower of Babel, which was stopped by the confusion of tongues. This was soon surrounded by other buildings, and walls of great magnitude ; and here, therefore, may we date the origin of postdiluvian architecture. Whatever celebrity, however, the wonders of Babylon attained, among the ancients, no remains of them have come down to us; and it is the massive edifices of Egypt, built, apparently, rather for eternity than time, which now excite our admiration as the most ancient as well as stupendous structures existing upon earth. We must not, while under this epoch, omit to notice the remains, and, alas! the only remains, of Indian and Mexican greatness. But for the splendid ruins of Delhi and Agra, and that most singular specimen in the island of Elephanta, we should scarcely have known of the existence of civilization among the ancient Hindoos ; and the aborigines of Mexico were regarded as little better than savages, before the late discoveries of Mr. Bullock. The dates of these buildings are wholly unknown ; but, from the general similarity they bear to those of Egypt, it is supposed they are of equal antiquity. It may not be improper here to observe that the latter country is commonly considered to have been peopled by a colony from India. About the same general date may also be assigned to the architecture of the Hebrews, or, as more properly characterized, the Phoenician style, the greatest monument of which was the far-famed temple of Solomon. The description of this, in the sacred text, will be found, on an accurate consideration, to bear great resemblance to that of many of the Egyptian temples. From the Egyptians the art, such as it was, was learned by the Greeks ; but under the protection of that extraordinary people it reached a perfection unheard of before, and, in its peculiar style, unequalled since. The earliest edifices of Greece, however, were by no means remarkable for beauty ; the temples, in the time of Homer, being little better than rude huts, sheltered, if sheltered at all, by branches of laurel and other trees. On the decline ( of Greece, and its conquest by the Romans, the art appears to have been transferred to the conquerors ; but among that hardy and warlike race it made little progress before the age of Augustus. Under the protection of that munificent monarch, it rapidly attained to almost as great perfection as in the favored country of the arts ; and the "Eternal City" owes much of its present estimation to the noble structure? erected by him and his successors. With Rome, however, the art decayed, and was overwhelmed in the general confusion and oblivion of learning, art, and science. The attention of the Saxons in Europe, probably about the eighth century, was excited by the remains of edifices raised by the Romans during their residence in England. These, in their newly-erected churches, they aspired to imitate ; but their workmen, ignorant of the principles which guided the architects of those splendid ruins, produced only the general outlines of their patterns ; and those clumsy forms continued to be practised, with little alteration, till the end of the twelfth century. But now, as the tumult excited by the invasion subsided, and the genius of the nation improved, a taste for the fine arts began to show itself, and architecture assumed a different and novel aspect. Instead of tamely treading in the steps of their predecessors, the architects of those times devised a style as scientific as it was grand, and as beautiful as new. But we must not, while eulogizing those who have adorned their own country with such admirable structures, forget the merits of their contemporaries on the continent. Of these, it seems to be generally acknowledged that the French preceded them in point of time, and the Germans excelled in the size of their edifices ; yet no one, on comparing, with an impartial eye, the several buildings, will hesitate to allow that, in purity of style, variety of design, and delicacy of execution, the English cathedral and other churches are not surpassed by those of any nation in Europe ; and it is a remarkable fact that English architects and workmen were employed in many of the finest works on the continent. We must now turn our attention to Italy. It is worthy of notice that the Gothic style never came to so great perfection in this country as in the neighboring nations. Perhaps this was owing to the number of Roman buildings remaining amongst them, and the liberal use they made of their fragments, which is shown even in the finest specimen they possess. The Milan cathedral is probably the purest Gothic building in all Italy. But this is not built of fragments of ancient Roman buildings. It was built chiefly by Bonaparte, or under his auspices, and is of white marble. It is not, therefore, surprising that the Italians should be the first to reject the style altogether. Indeed, there were instances, in the darkest times, of recurrence to the purest models of antiquity,* but these met not the public taste, and were born only to die. "It is not," observes Mr. Bromley, "the casual and solitary effort of individuals in a dark age, which can be considered as renovating the decayed principles of pure science. Some minds are naturally stronger and more intent on improvement than others ; and where such happen, in some degree, to break through the general obscurity, they only show that the genuine light of refinement is not quite extinct, though the age will be little or nothing the better for those faint glimpses which become the portion of one or two, and are neither attained nor sought by others." To return to our subject. The Church of the Apostles, at Florence," which was built by Charlemagne in A. J). 805, appears to have been the first effort to revive the forgotten architecture of ancient times, and possessed so much merit that Bruneleschi, six hundred years afterwards, disdained not to accept it as a lesson in one of his own edifices. Two hundred years passed away, and the Church of St. Miniate, in the same illustrious city, momentarily recalled from its apparent oblivion this elegant style. The same period again elapsed, and the genius of Cimabue arose to dispel the mists which had so long enveloped the arts of his country. His atten tion, though principally devoted to painting, was, like that of most of the great artists of his time, occasionally turned to the sister arts ; and it was partly by his instructions that Arnolphi di Lapo became the wonder of the age. The father of this eminent architect, James, was a German by birth, but resided at Florence, where he built the convent of St. Francis, and received the surname of Lapo, from the citizens, for his skill in architecture. The son, Arnolpho, built the cathedral of St. Maria del Fiore, the largest church in Christendom, next to St. Peter's. Although this was principally in the Tedeschi style (the appellation given by the Italians to the debased Gothic of their country), yet so uncommon was the skill displayed in its erection, that, the dome being left unfinished by the death of the architect, a century and a half elapsed before another could be found to raise it. This was Bruneleschi, architecture. His principal work was the Palazzo Pitti, in his native city. It might have been expected that Rome, which possessed so many fine specimens, would have been the first to show to the world her sense of their value by encouraging the imitation of them ; but it was not till the middle of the fifteenth century that Pope Nicholas V. manifested the first symptoms of reviving taste, by the encouragement of Leone Baptista Alberti (the earliest modern writer on architecture), and Bernardo Rossilini. These, however, were principally employed in repairs, and the erection of fountains ; and to Bramante must we concede the honor of being the first who materially adorned this city by his designs. With the then pope, the memorable Julius II., he was much in favor, and it is supposed that it is in a considerable degree owing to this architect that that- munificent pontiff formed the resolution of rebuilding the cathedral of St. Peter, in a style suited to the importance and magnificence of the see. In the lifetime of Bramante, however, little was done of this stupendous work ; for such was the conception of the architect's colossal imagination, that, although in its present state its section is about double that of St. Paul's, at London, it was reduced by his successor, Balthazar Peruzzi, and more considerably by the next who took it in hand, Antonio de San Gallo. These architects, however, while they exerted their talents on paper, proceeded little with the work; and it was left for the sublime genius of Michael Angelo permanently to fix the design of this master-piece of art, and prince of Christian churches. The edif^e, as we now see it, is principally his, except the front, which is considered in-fcrior to the other parts. This work completed, the example thus set by its principal cities was quickly followed in all parts of Italy, winch thus gave ruployment to the talents of Pirro Sigorio, Vignola, Domenico, Fontana, Michael San Michael, Falconetti, Serlio, Barbaro, Scamozzi, and Palladio. long duration. The celebrated artist, Bernini, was one of the first who violated their precepts. He was educated at Rome as an architect and sculptor, and it is related of him, that, returning to his native city late in life, with a fortune, the product of his talents, he was much struck with some of his early works, of the school of Michael Angelo and Palladio. He could not but contrast their elegance with the affected graces of the style he had given into ; " but," exclaimed he, " had I continued in this manner, I should not have been what I am now." Contemporary with Bernini was Borromini, who was yet more depraved, and was so jealous of the former's fame that he stabbed himself. After these, Italy cannot boast of any great architects. Europe. From the time of Edward III., there was a visible decline in the style of English architecture, which lost itself in a profusion of ornaments ; more attention being paid to the details than to the general form of the buildings. By the time of Henry VIII., this increased to a great extent, and the chapel erected by his father at Westminster was one of the last buildings which showed any taste in the style. This depraved manner naturally excited disgust in the minds of those persons who had seen the purer style then prevailing in Italy, which, as might be expected, they endeavored to introduce. The nation,. however, had been too long accustom^ to the Gothic readily to surrender it, and during the reigns of Elizabeth and James the mixture of, or compromise between, these styles, produced a most barbarous result. Bui this could not last long ; the prejudices of the people, in the course of time, gave way, eM Italian architecture, in all its purity, was first executed in this country by Inigo Jones. This father of modern English architecture was born about 1572, and died in 1652. At the expense either of the Earl of Pembroke, or the Earl of Arundel, he travelled intoTtaly, and from the sight of the elegant buildings in that country, both of ancient and modern erection, he imbibed a taste for architecture, which he put in practice, with great success, on his return to England. His first work, in that country, was the interior of the church of St. Catherine Cree, in London; and his most considerable design, the projected palace of "Whitehall, the part of which that is executed, the banqueting-house, being barely one-fiftieth part of that magnificent idea. After the death of Jones, no considerable architect appeared, till the talents of Sir Christopher Wren (before that time deyoted to philosophy and general learning) were called to the aid of the languishing art. He was born in the year 1G32, and died at the age of ninety-one, in 1723, after being, in his eighty-sixth year, barbarously dismissed from the office of surveyorgeneral,, which he had held with unparalleled ability fifty-one years. When that temporarily disastrous yet permanently useful event, the fire of London, occurred, this great man was almost solely employed in rebuilding the numerous public edifices destroyed by the conflagration, and chiefly the cathedral of St. Paul, his execution of which arduous task, whatever be the objections raised against parts of it, by the taste of some, and the jealousy of others, remains a lasting monument of his genius in decorative and unexampled skill in constructive architecture. Before the death of Wren, appeared Sir John Vanbrugh, who was employed by the nation to erect that monument of national gratitude, Blenheim House. Both the architect, and this, his greatest work, were alternately neglected and censured, till Sir J oshua Reynolds vindicated his fame in his lectures to the Royal Academy. Next in order were Hawksmoor, the pupil of Wren, Lord Burlington, Kent, and Gibbs, of the last of whom Mr. Mitford observes, that, allowing his talents to be small, how much do we owe to Lord Burlington, that by his precepts such a man was enabled to build one of the finest modern works, St. Martin's Church in the Fields. To Lord Burlington, indeed, it is probable we owe more than is generally acknowle Iged; for, besides the patronage he afforded to the artists of his time, and the assistance ho gave them from his own genius, it is, perhaps, owing to his example that a general feeling of attachment to the arts was conceived by the young men of rank and fortune in England. The Turkish government, which, in its prosperity, ruled with a rod of iron the once fertile plains of Greece, began now, in its decline, to relax a little of its ancient rigor, and these gentlemen were thus enabled to extend their travels (which before were bounded by the Archipelago) into this important country. Some of them formed, at their return, the Dilettanti Society, for the encouragement of researches into those (to modern times) new regions. These proceedings could not but excite great interest and curiosity in the public mind, which were fully gratified, after some years, by Mr. Stuart ; who, during a long residence at Athens, made accurate drawings of most of the ancient buildings then existing. These were published in three volumes, folio, to which a fourth was afterwards added by Mr. Revely. The effect of these importations may be seen in every street in London. The revival of the neglected architecture of the middle ages constitutes a new era in our history. Perhaps the first person who dared to recommend, by writing and example, a style so long in disrepute, was the celebrated Horace Walpole, Earl of Orford, who built the well-known villa of Strawberry Hill to testify his fondness for it. This was succeeded by Lee Priory, by Mr. Wyatt, who quickly outstripped all the professors of his day, both in this style and the Roman. His greatest work, in Gothic architecture, was Fonthill Abbey, the merits of which building, when we consider that the architect had no model to work from (there being not another house of magnitude, in this style, in the Avhole kingdom), are truly extraordinary ; the purest taste reigns throughout the whole of this splendid structure, and the architect has bequeathed to succeeding professors a legacy of incalculable value. Did we not know it to be a fact, Ave have every reason to believe, that, in the early ages of the world, stability was the first consideration. That men by nature are in a state of great inequality, is a truth which no rational person would be inclined to controvert. Some are weak, and some strong, and others have great powers of mind ; to these, those incapable of defending themselves would naturally apply for protection against their more powerful neighbors, and hence the origin of civilized society. But it is enough for our present purpose that from this combination proceeded the subject of our inquiry. Under these hands, as was before observed, massive strength would be more attended to than form or adornment. But we do not mean to insinuate that the buildings now to be considered are exactly of this class ; mighty and ponderous they are, but (excepting the pyramids, which did not admit of it) not destitute of decoration ; and some may even be said to possess a degree of elegance. It may probably be expected that, in delineating the peculiarities of the architecture of Egypt, we should begin with the pyramids, as most readily presenting themselves to the generality of readers. Little description, however, will suffice to give an idea of these stupendous monuments. The largest of them stands not far from the city of Cairo ; it is built on a rock ; its base is square, and its sides are equilateral triangles, except that there is a platform at top of about sixteen feet square, which, comparatively, is so small that it is said not to be discernible from below. The stones of which it is composed are of a prodigious size, the least of them thirty feet in length. These are disposed so as to present a series of steps on. the exterior. But, though we have thus thought fit to give a brief description of these mysterious and mighty monuments, it is not the pyramids that characterize the Egyptian style of architecture. Its distinguishing marks are to be found in the numerous temples dispersed through the country. _ As we know of no proportions attended to in the construction of these edifices, and have no means whereby to judge of their respective dates but by their richness or simplicity (qualities which, though they may be some general guides, are not alone sufficient data from which to form a chronological classification of edifices), we can have little more to say under this head, than to refer the reader who may wish to make himself acquainted with this style to the work of Denon, where he will find accurate delineations of the principal specimens. We cannot quit the subject, however, Avithout remarking the great variety and beauty of the capitals, in the elegant forms of some of which, borrowed from the palm-tree and the lotus, is found a far more probable origin for the Corinthian capital of the Greeks and Romans than in the pleasing yet probably fictitious story of Vitruvius. The architecture of the Romans having been almost entirely borrowed from that of their masters in art, though subjects in dominion, the Greeks, we shall, for greater clearness and brevity, consider them together. The various parts, of which both GRECIAN AND ROMAN ARCHITECTURE. 17 Greek and Roman orders are composed (the distinguishing members excepted), being nearly the same in all of them, we shall commence by a description of these. And, first, the greater members, which all possess in common. On referring to plate 33, fig. 3, it will be seen that we have marked letters, answering to dotted lines, proceeding from the order to the right hand. Of these, the upper division, a is the cornice, b the frieze, and c the architrave ; these form the horizontal part of the order, and are called the entablature ; d is the capital, e the shaft, and / the base ; these together form the column, or upright supporting part. The column is usually placed on a square tile, called the plinth. These, according to the variation of their parts, form what are called the orders of Greek and Roman architecture, which will be presently the subject of our consideration. The prototype of this arrangement is supposed by Vitruvius, and a host of followers, to be the wooden hut, of which we find the following account in Sir William Chambers: " Having marked out the space to be occupied by the hut, they fixed in the ground several upright trunks of trees, &c, to form the sides, filling the intervals between them with branches closely interwoven and spread over with clay. The sides thus completed, four beams were laid on the upright trunks, which, being well fastened together at the angles of their junction, kept the sides firm, and likewise served to support the covering or roof of the building, composed of smaller trees, placed horizontally, like joist, upon which were laid several beds of reeds, leaves, and earth or clay. By degrees other improvements took place, and means were found to make the fabric lasting, neat and handsome, as well as convenient. The bark and other protuberances were taken from the trees that formed the sides; these trees were raised above the dirt and humidity on stones, were covered at the top with other stones,-and firmly bound round at both ends with osiers or cords, to secure them from splitting. The spaces between the joists were closed up with clay or wax, and the ends of them either smoothed or covered with boards. The different beds of materials that composed the covering were cut straight at.Lhc eaves, and distinguished from each other by different projections. The form of the roof, too, was altered; for, being on account of its flatness unfit to throw off the rains, which sometimes fell in great abundance, it was raised in the middle on trees, disposed like rafters, after the form of a gable roof. " This construction, simple as it appears, probably gave birth to most of the parts that now adorn our buildings, particularly to the orders which may be considered as the basis of the whole decorative part of architecture ; for when structures of wood were set aside, and men began to erect solid stately edifices of stone, having nothingnearer to imitate, they naturally copied the parts which necessity introduced in the primitive hut, insomuch that the upright trees, with the stones and cordage at each end of them, were the origin of columns, bases and capitals ; the beams and joists gave rise to architraves and friezes, with their triglyphs and metopes ; and the gable roof was the origin of pediments ; as the beds of materials forming the covering, and the rafters supporting 'them, were of cornices with their corona, their mutules, modillions, and their dentils. " Such is the account which has been transmitted to us of the origin of these orders; and it has sufficed for and been unhesitatingly received by all, or the greater part, of our forefathers ; but the restless scepticism of modern times has not spared even this venerable and harmless notion. It is alleged that it is very improbable that stone should have been the immediate successor of wood as a building material ; the working of this substance of itself being no small acquirement, and not consistent with the rudeness of the' times; the employment of brick most probably intervened, and this was actually used at the tower of Babel. That- the Greeks derived their knowledge of this art from Egypt is generally allowed ; but, in the large hollowed crown mouldings and flat roofs of the temples of that country, little resemblance is than in this place. The Roman ovolo and cavetto are never found in the Grecian architecture, nor the Greek echinus in that of the Romans ; the rest they possess in common. The Greek mouldings are chiefly distinguished from the Roman by being composed of ellipses and other conic sections, while the Roman are formed of segments of circles. The Greek echinus and cyma-reversa are also, for the most part, quirked; that is, the contour is returned under the fillet above, as is shown in the Grecian echinus. In some early specimens of the Doric order, a straight line is used instead of the curve for the echinus, as in the capital of the portico of Philip, in the island of Delos. When the projection of these mouldings is required to be greater or less than usual (which is sometimes the case, from peculiarity of situations), the best method of overcoming the difficulty is to make them of segments of ellipses, by which means it is evident any required projection may be obtained, and the shadows will be such as not readily to discover the defect. In places where the composition is unusually higher or lower than the eye, it is sometimes necessary to deviate from the customary manner of executing the mouldings, to make them appear of their proper forms. It is very rarely, however, that an expedient of this kind is necessary, and it should never be resorted to ; but when it is, the forms, when closely examined, are very unpleasing. All the mouldings, except the fillet, admit of decoration ; but, even in the most enriched profile, it is proper to leave some uncarved, to prevent confusion, and give a due repose to the composition. It is a fundamental rule, in the sculpture of mould ings, to cut the ornaments out of the contour, beyond which nothing should project, as this would inevitably alter its figure. The fillet may be used at all heights, and in most situations. The torus, only in bases. The scotia, below the eye and between the fillets attached to the torus. The echinus, only above the eye, and is fit for supports. The inverted cyma is also used as a supporting member. The cyma-recta and cavetto are only fit for crowning mouldings, for which their forms are peculiarly adapted, being incapable of holding water, which must necessarily drop from their extreme points. to the description of the orders. The orders of architecture are strictly three, the Doric, the Ionic, and the Corinthian ; and are found in the greatest perfection in Greece. But the Romans, determined to produce novelty, at the expense of excellence, formed, out of the first of these, two new orders, one of which they denominated the Tuscan, and the other, though very dissimilar to the ancient order of that name, they likewise called the Doric. The Ionic they altered less, but that likewise was decidedly for the worse, considering the orders for the temples of Minerva Polias, and Ilyssus, as the standard of Grecian art. The Corinthian they must be allowed to have improved, but formed a variation of it, frequently seen in the Roman buildings' particularly in the triumphal arches, which has been erected by the moderns into a fifth order, under the name of Roman, or Composite. The difference between this and the Corinthian, however, is much less than between the Greek and Roman Doric. Before we give the orders in detail, it will be necessary to observe that columns are tapered in their shafts ; that is, the circumference of the shaft at the capital is less than it is at the base, thus making a frustum of a cone ; but in most, or all of the ancient examples, the line, instead of being perfectly straight, is slightly curved. Sometimes the shaft is continued from the base, cylindrically, to about a quarter or third of its height, and then diminished rectilinearly to the top. This is called entasis, and in all the examples of antiquity is so slight as to be scarcely percep- THE TUSCAN ORDER, 21 tible. Vitruvius having obscurely hinted at the practice, several of the modern Italian artists, intending to conform to his precept, but not perceiving the result in the originals, carried it to an absurd excess, and made the thickness greater at the middle than at the foot of the shaft. The Tuscan order, as an antique, exists only in the works of Vitruvius; the description in which being very obscure, has left a wide field for the ingenuity of modern architects. Among these, Palladio composed two profiles, one from the description of the ancient master, and the other according to his own idea of a simplification of the Doric. That of Vignola, however, has been most generally approved and adopted. The base of this order consists of a simple torus with its fillet ; it is, as are in general all the Roman orders, accompanied with a plinth. The proportions, from Sir William Chambers, are as follows: the column, fourteen modules; the entablature, three modules, fifteen minutes. Of the former, the base occupies one module ; the shaft, including the astragal, which divides it from the capital, twelve modules, and the capital, one. Of the latter, the architrave, including the fillet, thirty-one minutes and a half; the frieze, the same; and the cornice, forty -two minutes. The intercolumniations, in all the orders except the Doric, are the same, namely : the eustyle, which is most common and beautiful, four modules, twenty minutes ; the diastyle, six modules; and aroeostyle, seven modules. The Tuscan order admits of no ornaments, nor flutes in the columns ; on the con trary, rustic cinctures are sometimes represented on the shaft of its column. But this practice, though occasionally used by good architects, is seldom compatible with good taste. This order may be employed in most cases where strength and simplicity are required, rather than magnificence ; such as prisons, market-places, arsenals, and the inferior parts of large buildings. This order, of which numerous ancient examples exist, will, in consequence, furnish us with more materials for description than the preceding. W e will commence with the story of its origin, as given by Vitruvius. " Dorus, son of Ilellen and the nymph Orseis, reigned over Achaia and Peloponnesus. He built a temple of this order, on a spot sacred to Juno, at Argos, an ancient city. Many temples similar to it were afterwards raised in other parts of Achaia, though at that time its proportions were not precisely established." This account, as well as of those of the orders which we shall presently examine, is very incredible, and is now generally rejected. From theory, however, we must now proceed to fact and description, and will commence with the Doric of the Greeks, referred to by Vitruvius, who, nevertheless, confounds this with what was commonly executed at Rome in his time. The most perfect example of this order is the Parthenon, or Temple of Minerva, on the Acropolis at Athens, erected by Ictinus, under the administration of Pericles, who lived B. C. 450. We shall therefore now give its proportions. The column (including the capital), ton modules, twenty-seven minutes and one-half; the whole entablature, three modules, twenty-seven minutes and three-quarters ; the capital, twenty-seven minutes and three-quarters ; the architrave (with its fillet), one module, twelve minutes and three-quarters ; the frieze, to the square member of the corona, one module, nineteen minutes ; and the cornice, twenty-six minutes. Diameter of the column at the top, one module, sixteen minutes. — Through the politeness of the Rev. John Pierpont, I have received the following note, which may be of consequence to the reader in ascertaining the magnitude of this edificev My Dear Sir: In compliance with your request, I here send you the dimensions of the different parts of the columns of that most exquisite of all the specimens of the Doric architecture, — the Parthenon, — from my own careful measurement, in April. I give the dimensions, not in modules and minutes, but in English feet and inches. I proceed to the order designated by this title by the Romans. Very few ancient examples of this variation exist. The most perfect is that of the Theatre of Marcellus, if, perhaps, we except that elaborate pile, Trajan's column, which is generally pronounced to be Tuscan. It is, therefore, principally indebted for its existence to the modern Italian architects, who, having little of antiquity before their eyes, appear to have bestowed more attention upon this order than the others ; and it must be confessed that they have made of it a very elegant design, though, as before observed, essentially different from the original and true Doric. The measures, from Sir William Chambers, are as follows : the base, thirty minutes ; the shaft, thirteen modules, twenty-eight minutes ; and the capital, thirty-two minutes ; the architrave, thirty minutes ; the frieze, to capital of triglyph, forty-two minutes ; and cornice, fortyfive minutes. Upper diameter of column, fifty minutes. In no example of antiquity is the Doric column provided with a base. I am inclined to think, either the architects had not yet thought of employing bases to their columns, or that they omitted them, in order to leave the pavement clear, as the architects of those times frequently placed their columns very near each other ; so, had they been made with bases, the passage between them would have been extremely narrow and inconvenient ; however, the Romans have introduced the attic base, Avhich is common to all of the orders except the Tuscan, though it more properly belongs to the Ionic. This base has two tori, a scotia and two fillets between them ; above the upper torus is an inverted cavetto and fillet properly belonging to the shaft of the column, as is also that under the capital ; for which reason they are commonly considered as belonging to the shaft. The plinth or square member beneath the base is usually considered indispensable in Roman architecture, although Palladio has omitted it in his Corinthian order ; but it is scarcely found in the Greek specimens. The intercolumniation takes from this style, in no small degree, the imposing grandeur which is so characteristic of the Grecian style. The most striking THE DORIC ORDER. peculiarity of the Doric order is the triglyph, which admits of the idea of the beams being placed transversely on the architrave, which more conforms to Grecian examples; hence, the angles are supplied with a beam forming the flanks ; but this will not hold good in the Roman examples, where the beams at the angles arc placed over the centre of the column, which leaves the wall destitute of a beam to support the roof. The triglyph is surmounted by the mutule, in the Greek, and, in some Roman examples, inclined, but in most modern profiles, horizontal ; on its soffit are represented gutta, or drops. The spaces between the triglyphs on the frieze are called metopes, which, in the modem Doric, are invariably perfectly square, and generally enriched with sculptures. A part of the ornamented metopes of the Parthenon were brought to England by Lord Elgin, and now form the principal attraction in the collection which is known by his name in the British Museum. In the modern order, these sculptures are most commonly an alternate bull's skull and patera. The extreme projection of all these ornaments should be less than that of the triglyph itself, thus keeping a due subordination between mere decorations and essential parts. All the Grecian Doric columns are fluted, and in both Greek and Roman this is performed without fillets between, as in the other orders. The intercolumniations in this order differ from those of the others, on account of the triglyph, the metopes being required to be exactly square. They are as follows: The coupled columns, of course, must stand under adjoining triglyphs ; this makes their distance, at the foot of the shaft, twenty-one minutes. The next intercolumniation is the monotriglyplr, which has one between the columns ; the distance is three modules. The diastyle, — two triglyphs, five modules and a half. The araeostyle, which has three between, eight modules. This last is a size which should never be resorted to but in cases of great necessity ; and, indeed, is seldom practicable. Portico of the Agora, at Athens, . . . Temple of Minerva, at Sunium, . . . Temple of Jupiter Nemaeus, . . . . Temple of Jupiter Panhellenius, . . . Vitruvius informs us that in a general assembly of the Grecian states thirteen colonies were sent over into Asia, by the Athenians ; the expedition was led on by Ion, whom the Delphic oracle, which directed the emigration, had acknowledged for the offspring of Apollo. They settled on the borders of Caria, and built several cities of great fame, of which were Ephesus, Miletus, Samos, and Colophon, to which Smyrna was afterwards added ; and, after the expulsion of the original inhabitants, these colonics were denominated Ionian, from the name of their chief. " In this country," continues he, "allotting different sites to sacred purposes, they erected temples, the first of which was dedicated to Apollo Panionius. It resembled that which they had seen in Achaia, and from the species having been first used in the cities of the Dorians, they gave it the name of Doric. As they wished to erect this temple with columns, and were -not acquainted with their proportions, nor the mode in which they should be adjusted, so as to be both adapted to the reception of the superincumbent weight, and to have a beautiful effect, they measured a man's height by the length of the foot, which they found to be a sixth part thereof, and thence deduced the proportions of their columns. Thus the Doric order borrowed its proportion, strength and beauty, from the human figure. On similar principles they afterwards built the temple of Diana ; but in this, from a desire of varying the proportions, they used the female figure as a standard, making the height of the column eight times its thickness, for the purpose of giving it a more lofty effect. Under this new order they placed a base, as a shoe to the foot. They also added volutes to the capital, resembling the graceful curls of the hair, hanging therefrom to the right and left. On the shaft channels were sunk, bearing a resemblance to the folds of a matronal garment. Thus were two orders invented, one of a masculine character, without ornament, the other approaching the delicacy, decorations, and proportion of a female. The successors of these people, improving in taste, and preferring :i more slender proportion, assigned seven diameters to the height of the Doric column, and eight and a half to the Ionic. The species of which the Ionians were the inventors received the appellation of Ionic." The volute is a distinguishing feature of the Ionic. I now give the proportional figures from Nicholson's Architectural Dictionary, from the Erectheus'at Athens. First find the lesser projection of the echinus ; let drop a plumb-line 40 minutes of the order, the depth of the volute. Divide this line into 34 parts, give 20 to the upper division, take 2.4 for the radius of the eye, divide the radius into eight parts, then counting from the plumb-line at top, measuring from the centre of the eye ; second, 18.3 ; third, 16.7 ; fourth, 15.3 ; fifth, 14 ; sixth, 12.8 ; seventh, 11.7 ; eighth, 10.7. Second revolution — first, 9.8 ; second, 9 ; third, 8.2 ; fourth, 7.5; fifth, 6.9; sixth, 6.3; seventh, 5.7; eighth, 5.2. Third revolution — first, 4.8 ; second, 4.4 ; third, 4 ; fourth, 3.7 ; fifth, 3.4 ; sixth, 3.1 ; seventh, 2.8 ; eighth, 2.6 ; the diameter of the eye, 4.8. than is practicable in the former method of forming the spiral lines I will now describe. For the depth of the volute, take 40 minutes of the order. Drop a plumb-line from the lesser projection of the echinus, taking 22.5 minutes from the echinus to the centre of the eye, leaving 17.5 minutes from the centre of the eye to the bottom of the volute ; find a right angle from the centre of the eye, take one-half minute in your dividers and space of 3 on each of the angles, from the centre parallel * to each of those angles extending the four lines from the intersection, so that the curve of the first revolution will cut each ; then extend the second audinets to the second revolution, the third to the third; take three minutes in your dividers, placing one point of fhe dividers at the centre, and describe the eye ; six minutes being the diameter of the eye, now we form the spiral lines from each quadrant A, B, C. The first extends points of the dividers from B to A; draw the curve from A to E; then from D to C draw to E; from F to E draw G; from H O to first revolution. Then 11 to 2; from 3.2 to 4; from 5.4 to 6; from 9.6 to 8 — second revolution. Take the inner square and perform the third revolution in the same manner as the first and second, and for four revolutions make the sides of the squares into eight half-minutes, four on each of the angles from the centre, and proceed as in the three revolutions. Athens ; the two latter of which are so similar that we shall not here discriminate between them. We are thus reduced to two Greek examples, and they are so exquisitely beautiful that it is difficult to give the preference to either. We will, therefore, describe both. The temple on the Ilyssus is the plainer of the two ; its volute consists of a single spiral, with a deep channel between, and is separated from the shaft by the sculptured echinus. The architrave is not broken into fascise, as in most other specimens. The cornice consists simply of a square member, with one echinus and fillet, surmounted by the cymatium ; the bed-mouldings in the elevations are completely concealed. The base is composed of two tori, the upper of which is channelled horizontally and surmounted by a bead enclosing a very flat scotia, the upper fillet of which projects as far as the extremity of the torus. The fillets are semi-elliptical. The following are the measures of this order : the column, including base and capital, sixteen modules, fourteen minutes and one-fifth ; the base, twenty-nine minutes and four-fifths ; the capital, to- the bottom of the volute, forty minutes; the architrave, fifty-five minutes and two-fifths ; the frieze, forty-nine minutes ; the cornice, thirty minutes and one-fifth. Width of the capital, three modules, three minutes ; upper diameter of column, fifty-one minutes ; intercolumniation, from centre to centre of column, six modules, five minutes and two-fifths. The order of the temple of Minerva Polias is next to be considered. This example is much richer, yet no less elegant, than the other ; the volute, instead of a single spiral, is formed by three ; the sculptured echinus beneath is surmounted by a guilloched moulding, and separated from the shaft by a neck adorned with honeysuckles. The base is very similar to that of the temple on the Ilyssus, except that its beauty is increased by the diminution of its height, the scotia is deeper, and the upper torus is guilloched. The architrave consists of three fasciae, and the cornice is similar to that of the Ilyssus temple, except that the echinus and bed-mouldings are sculptured, and the astragal of the latter is seen in the elevation beneath the corona. Tho column, including base and capital, is eighteen modules, seven minutes and onetenth in height ; the base, twenty-four minutes ; and the capital, forty-two ; the architrave, forty-five minutes and one-fourth ; the frieze, forty-seven minutes and four-fifths ; and the cornice, to the fillet of the echinus, which is the greatest actual height of the entablature, the cymatium being a restoration, twenty minutes and twofifths. The width of the capital, three modules, three minutes. Upper diameter of column, forty-nine minutes and a half. Intercolumniation, from centre to centre, nine modules. Both of these examples are destitute of insulated plinths. Having thus given our readers an idea of the finest Greek specimens of this order, we must now proceed to the Roman and Italian examples of it. It is the peculiarity of this order that its front and side faces are dissimilar. To obviate this inconvenience, the Greeks twisted the extreme volutes of a portico so as to make the two faces alike. But Scamozzi, a famous Italian architect, designed a capital in which the volutes proceeded angularly from the shaft, thus presenting the same front every way ; and the capital, so executed, has been generally attributed to the supposed inventor. Sir William Chambers, however, is of opinion that Michael Angelo was the author of one of this description in the Vatican at Rome. This capital is commonly known as modern Ionic, but it has not been executed on large works. The frieze of this order has been by many architects, and Palladio among the number, rounded in its architrave, as though it were pressed down and bent by the superincumbent weight ; but the ill effect of this has been so generally perceived, that it is rarely to be seen in late works. The cornice is distinguished from the Greek by its variety of mouldings, among which the most remarkable is a square member in the bed-mouldings, cut into small divisions, somewhat resembling teeth, whence they are called dentils. In other points of variation between the Grecian and Roman architecture, there m&y be a difference of opinion ; but with respect to the Ionic capital, we conceive this THE ROMAN, OR COMPOSITE ORDER. 31 to be impossible. Whoever compares the meagre, petty form of the temple of Concord with that of the Erectheion, must instantly, whatever be his former prejudices, perceive the amazing difference, and unhesitatingly acknowledge the vast superiority of the latter. The poverty of the solitary revolving fillet, the flat, insipid lines, and the enormous projection of the clumsy echinus, combine to render this the very worst feature in all the Italian orders. The base commonly used is the attic, though Vitruvius has appropriated one to this order resembling the Corinthian without its lower torus. The following are the measures of the order, from Sir William Chambers : the base, one module ; the shaft, sixteen modules, nine minutes ; and the capital, twentyone minutes. The architrave, forty minutes and a half; the frieze, the same ; and the cornice, fifty-four minutes. Width of capital, two modules, twenty-six minutes. Upper diameter of column, fifty minutes. "As the Doric order," says Sir William Chambers, " is particularly affected in churches or temples dedicated to male saints, so the Ionic is principally used in such as are consecrated to females of the matronal state." It is likewise employed in courts of justice, in libraries, colleges, seminaries and other structures having relation to arts or letters; in private houses and in palaces; to adorn the women's apartments ; and, says Le Clerc, in all places dedicated to peace and tranquillity. The ancients employed it in temples sacred to Juno, to Bacchus, to Diana, and other deities whose characters held a medium between the severe and the effeminate. This order, though not considered by them as a distinct one, was employed by the Romans principally in triumphal arches ; the column and entablature being the same as, or little different from, the Corinthian. This difference was, however, sufficient for the Italians to ground a new order upon. The capital, as being composed of the Ionic and Corinthian, they termed composite; and, to justify the application of the name to the order in general, they combined in the entablature the dentils of the Ionic Avith the mutules of the Doric, and enrichments of the Corinthian, and gave to the architrave but two fascioe, thus rendering it in some respects more simple, but more enriched than the latter, while the former had little but the name left in the composition. The whole order may be safely pronounced heavy without possessing grandeur, and rich though destitute of beauty. It has been frecpiently adopted, and it is to be lamented that Sir Christopher Wren has made so much use of it about St. Paul's. The base commonly appropriated to this order is extremely beautiful ; it consists of two tori, the lower of which is considerably the larger, with two scotia3, enclosing an astragal. This is called the proper base of the order, but the attic is usually employed, being more simple, and consequently less expensive, than the other. The measures of this order, from Sir William Chambers, are as follows : the base, thirty minutes ; the shaft, sixteen modules, twenty minutes ; and the capital, two modules, ten minutes; the architrave, forty-five minutes; and the cornice, two modules. The story of this order, given by Vitruvius, is as follows : " The third species of columns, which is called the Corinthian, resembles, in its character, the graceful, elegant appearance of a virgin, whose limbs are of a more delicate form, and whose, ornaments should be unobtrusive. The invention of the capital of this order arose from the following circumstance : A Corinthian virgin, Avho was of marriageable age, fell a victim to a violent disorder ; after her interment, her nurse, collecting in a basket those articles to which she had shown a partiality when alive, carried them to her tomb, and placed a tile on the basket for the longer preservation of its contents. The basket was accidentally placed on the root of an acanthus-plant, which, pressed by the weight, shot forth, towards spring, in stems of large foliage, and, in the course of its growth, reached the angles of the tile, and thus formed volutes at the extremities. Callimachus, who, for his great ingenuity and taste in sculpture, was called by the Athenians y.uTuie-/vo^, happening to pass by the tomb, observed the basket and the delicacy of the foliage which surrounded it. Pleased with the form and the novelty of the combination, he took the hint for inventing these columns, and used them in the country about Corinth, regulating by this model the style and proportion of the Corinthian order." It has been before observed, in our notice of Egyptian architecture, that the capitals to be found in the country are much more likely to have given the hint for the Corinthian than the circumstance here mentioned. The only pure example of this order in Greece is the monument of Lysicrates. The capital of this specimen is exquisitely beautiful, but the same praise cannot, in the opinion of the writer, be justly awarded to the entablature ; the^ architrave is disproportionately large, and the frieze extremely small ; the bed-mouldings of the cormce, which completely overpower the corona, consist of large dentils, supported by the echinus and surmounted by a cyma-recta under a cyma-reversa, which supports the corona. The base is extremely beautiful, resembling that of the temple of Minerva Polias, except that an inverted echinus is substituted for the upper torus ; the base stands upon a large inverted cavetto, connected with the continued plinth by another inverted echinus. The flutes terminate upwards in the form of leaves, instead of being divided from the capital, as usual, by an astragal. The building is circular, and its centre is the summit of an equilateral triangle, of which the base is in a line bounded by the centn s of any two of the columns ; the intercolumniation is six modules, thirteen minutes and twd-fifths, of which the base occupies twenty-one minutes ; and the capital, two modules, twenty-seven minutes. The architrave, fifty-three minutes and two-fifths ; the frieze, forty-one minutes and two-fifths ; and the cornice, forty-eight minutes and four-fifths. The finest Roman example of this order is that of three columns k the Campo Vaccino, at Rome, which are commonly regarded as the remains of the temple of Jupiter Stator. This example has received the commendations of all modern artists, yet has seldom been executed in its original form. This is probably owing to the excessive richness and delicacy of it, which renders its adoption very expensive ; and perhaps the modifications of it by Vignola is preferable to the original, possessing a sufficient enrichment, without the excessive refinement of the other. In this 'order, which has been adopted by Sir William Chambers, the base is one module in height; the shaft, sixteen modules, twenty minutes; and the capital, two modules, ten minutes ; thus giving ten diameters to the whole column. The architrave and frieze are each one module, fifteen minutes in height; and the cornice, tw"o modules. The cornice is distinguished by modillions interposing between the bedmouldings aud the corona ; the latter is formed by a scpiare member, surmounted by a cymatium supports by a small ogee ; the former is composed by dentils, supported by a cyma-reversa, and covered by an ovolo. When the order is enriched, which is usually the case, these mouldings, exiting the cymatium and square of the corona, arc all sculptured ; the column is also fluted, UUfl the channels are sometimes filled i bout a third of their height with cablings, whicu are cylindrical pieces let into the channels. When the column is large and near the eye, these are recommended as strengthening them, and rendering the fillets less liable to fracture ; but when they are not approached, it is better to leave the flutes plain. They arc sometimes sculptured, but this should be only in highly-enriched orders. The flutes are twentybur in number, and commonly semi-circular in their plan. The Corinthian base is similar to that of the composite order, excepting that astragals are employed between the scotise, instead of one ; but the attic is usually employed for the reasons before assigned. PERSIANS AND CARYATIDES. where elegance, gayety and magnificence, are required. The ancients employed it in building temples dedicated to Venus, to Flora, Proserpine and the nymphs of fountains, because the flowers, foliage and volutes, with which it is adorned, seemed well adapted to the delicacy and elegance of such deities. Being the most splendid of all the orders, it is extremely proper for the decoration of palaces, public squares or galleries, and arcades surrounding them ; for churches dedicated to the Virgin Mary, or to other virgin saints ; and, on account of its rich, gay and graceful appearance, it may, with propriety, be used in theatres, in ball or banqueting rooms, and in all places consecrated to festive mirth, or convivial recreation." Having now described what are called the regular orders, it is necessary to notice, in the next place, the employment of human figures, instead of columns, for the support of an entablature. We will first give, as in former cases, the account of Vitruvius. " Carya, a city of Peloponnesus, took part wit! the Persians against the Grecian states. When the country was freed from its invaders, the Greeks turned their arms against the Caryans, and, upon the capture of the city, put the males to the sword and led the females into captivity. The architects of that time, for the purpose of perpetuating the ignominy of the people, instead of columns in the porticos of their buildings, substituted statues of these women, faithfully copying their ornaments, and the drapery with which they were attired, the mode of which they were not permitted to change." There are two great objections to the truth of 11m story : first, that the circumstance is not mentioned by any of the Grecian historians ; and, secondly, that it is certain that animal figures erc employed for this purpose long previous to the time assigned by Vitruviin- purpose we must trespass ou the kindness of Mr. Gwilt, the only writer, we believe, who has given a satisfactory account of them. He conjectures the name to have arisen from the employment of them in temples to Diana, who is supposed to have made the Lacedemonians acquainted with the story of Carya (turned into a nut by Bacchus, who also transformed her sisters into stones), and thence worshipped by them, under the name of Caryatis. Thus being first employed in temples to this goddess, they afterwards came into use in other buildings as representations of the nymphs who assisted at the mysteries of the patron goddess. They may be seen at St. Pancras Church, correctly copied from the Pandroseum, the only Greek building remaining where they are employed. The entablature of this example is extremely heavy, consisting only of an architrave and enormous cornice with dentils, which, however disproportionate in its situation, is, of itself, very beautiful. There are no remains of these figures in ancient Rome. The moderns have assigned the Ionic entablature to Caryatides, and the Doric when the figures of men are employed, which are called Persians. Caryatides are, when appropriately designed, well adapted for buildings devoted to pleasure, such as theatres, ball-rooms, &c, but are decidedly improper for sacred edifices. They should not be represented much above the natural size, "lest they should appear hitleous in the eyes of the fair." For male figures, on the contrary, a large size is desirable ; they are said to be proper for military buildings. The contradictions of some of the French architects on this subject are very curious. Le Clerc tells us that it is very wrong to represent Caryatides in servile attitudes, such characters being very injurious to the sex. On the contrary, they should be considered the greatest ornaments to buildings, as their prototypes are of creation, and represented in respectful charaU-.ers. But M. de Chambrai disagrees with his learned friend, and considers this practice as an error, observing that if the text of Vitruvius be attended to, it will be perceived that it is very improper to represent saints and angels loaded like slaves with cornices and other heavy burdens. He likewise considers them as improper for churches, in which, as houses of God, and asylums of mercy, vengeance and slavery ought never to appear. M. Blondel again observes, " that though this remark be just, if the origin of these ornaments be rigorously attended to, yet to serve in the house of God, and particularly at the altar, has always appeared, in the minds of the prophets and saints, so glorious and great, that not only men, but angels-, ought to esteem it a happiness ; and that, consequently, it can be no indication of disrespect to employ their representations in offices which they would themselves execute with pleasure." Such are the frivolous questions and debates into which blind reverence for antiquity has involved men of considerable talents. Leaving them, however, to such as are inclined to pay them attention, it is now requisite to describe a species of figures, which, on account of its simplicity, has sometimes been substituted for Caryatides. They are called termini, or terms, and derive their name and origin from the boundary-stones of the Romans, to render which inviolate, Numa Pompilius erected the terminus into a deity, and he was first worshipped in the similitude of a stone. This was afterwards improved into a human head upon a pedestal, smaller at the bottom than the top ; and they are thus, with numerous variations, represented in buildings. Pilasters, when they are attached to walls, are square, projecting from one-fifth to one-half the breadth of the face, and when erected on the angles of buildings show two equal faces. When attached to columns, the width should be nearly equal to the neck of the column to which it may be attached ; in this case, the Grecians introduced small projections in the walls, with bases and capitals, termed antoe. These were sometimes erected on the angles of porticos,^and in the rear columns, where the walls cause the flanks, uniting with the wall of the building, to give the front that solidity required in large works, in which the width requires more space than a single pilaster. Divide the face into two equal parts, and leave the space between them equal to one-fourth of the anta, or pilaster ; these antse were seldom accompanied with volutes, as were columns of the Ionic. Columns are most frequently placed on the ground, but are sometimes raised on insulated basements, called pedestals. A pedestal is, like a column, composed of three parts, — the base, the body, or die, and the cornice, — the decorations of which vary according to the order in which it is employed. The best method of arranging them is that employed by Vignola, who makes them, in all the orders, one-third the height of the column, thus preserving the character of the order. The die is always the same size as the plinth of the column, and the base and cornice are regulated by the delicacy of the order. of crowded assemblies. Where columns are employed to decorate the gable of a building, in which situation they usually form what is called a portico, the triangle formed by the roof projecting upwards from the entablatures is called a pediment. The entablature in this case is covered by two straight inclined cornices, the mouldings of which are similar to the horizontal one ; the space enclosed is called the tympanum. This was the original pediment, and the only form found in Greece ; but the Romans, to vary PEDIMENTS. 39 the form, employed in smaller works a segment, or a circle, instead of the triangle. The former, however, is heavy, and is only used as a covering to gates, doors, windows, and such smaller architectural works, where, by reason of their diminutiveness, they may produce variety, without being disagreeable to the eye. The cymatium, when the horizontal cornice with a pediment, is omitted, and only used in the inclined cornice ; otherwise this moulding would occur twice together in the same profile. The mutules, dentils and modillions, in the inclined or segmental cornice, must always answer perpendicularly to those in the horizontal one, and their sides must be perpendicular to the latter. The proportion of a pediment depends upon the length of the base line, the cornice being of the same size ; and in a portico with many columns the tympanum will not be of the same proportion to the rest of the composition, as when it is composed by a few. The method of determining the height of the pediment has lately been given in a French pamphlet, more, correctly than before. It is this : first, from the summit of an equilateral triangle, the base of which is the upper fillet of the horizontal cornice, with one side of the triangle as radius, describe an arc ; with the point of intersection between this arc and the centre line of the composition as a centre, and with the depth of the horizontal cornice as a radius, describe part of a circle. A line, drawn from the extreme boundary of the upper moulding of the horizontal cornice, passing as a tangent to the circle, gives the inclination of the pediment. In more modern practice, the height of a pediment is more commonly ascertained by dividing the base line into three, four, or five equal parts ; give one to a perpendicular raised from the centre and upper fillet of the horizontal cornice ; draw a line from the extreme point of the fillet to the top of the perpendicular ; draw the crown moulding and the remainder of the cornice below the line of inclination ; either of those angles is sufficient to be made tight by shingles or slating, and a lesser inclination will answer a good purpose for covering with galvanized iron, tin, or copper. It has been before observed, that the rude buildings of the Saxons and Normans in Europe, which are evidently copied from those of the Romans, may, by gradual improvement, have given rise to Gothic architecture ; and that this was the case in England, at least, there is no doubt. But there are certain peculiarities, even in these crude and imperfect attempts, though afterwards more fully developed, which require to be noticed before we proceed further ; plainly indicating that the works in question were .raised under the influence of a less ardent sun, and more obscure sky. In the happy climate of Greece, where little was to be feared from change of weather, the temples, the only buildings distinguished for architectural excellence, were frequently destitute of covering. Windows, in this case, being entirely superfluous, the walls were, in many instances, pierced only by a single door, which served at once for ingress and egress to both priests and worshippers. Science here, therefore, was npt needed, and, indeed, is not to be found. With the practical application of the principle of the arch the Greeks do not appear to have been acquainted ; the large stones which, in those early ages, were to be procured in abundance, being sufficient to cover the columns and the opening of the doors. As architecture improved, however, roofs were added to these edifices ; and, to throw off the rain, they were inclined downwards from the centre to the extremities. This inclination, in a climate where so little rain or snow fell, required to be but small ; but in Rome, which is more northern, it was found convenient to increase it to meet the exigencies of the situation. In countries far more exposed to vicissitudes of weather than either of those, it is evident that a very different piSt will be requisite ; and this theory is verified by the buildings of northern climates, the architects of which, though totally unacquainted with the works of their southern predecessors, by a singular coincidence adapted their roofs to their latitude in a regular scale of gradation from GOTHIC ARCHITECTURE. them. The_Saxon and Norman architects, though they did not comprehend this principle in the perfection to which it was afterwards carried, were sensible of the wants of the climate, and made their roofs much higher than those .of their Roman prototypes. This circumstance presenting itself to minds so quick to perceive, and so able to adopt, any novelty which came recommended by utility and beauty, as were those of the architects of the middle ages, could not fail of meeting with the highest attention. It was soon seen that unbroken vertical lines and lofty buildings were necessary, tg harmonize with the high pitched roof; and the pointed arch is but a natural and easy deduction from these data. But there is another and an important peculiarity in buildings designed for northern climates, to which we must next call the attention of our readers. This arises from the numerous circumstances which, in these regions, conspire to obscure the rays of the sun. The great darkness which prevails in them, compared with Greece and Italy, evidently requires a very different arrangement in the public buildings, and this circumstance has received no small share of the attention of the architects whose works we are considering. The variety and beauty of its windows is not the least striking peculiarity of Gothic architecture ; and, indeed, they form the readiest criterion for distinguishing the several styles, as we shall see hereafter. A third essential point of distinction, between this style and all others, consists in the different purposes for which the edifices were constructed, in which it is most apparent, and the different ceremonies for which they were adapted. Although the rites of Greek and Roman Paganism were numerous and splendid, they required little aid from architecture ; the ceremonies with which they wore connected were principally performed in the open air, and the temple was only used as a receptacle for the statue of the deity before which sacrifices were offered, and to which prayers wore preferred. But Christian worship under papal guidance, and in a country so cold as to rendei shelter necessary for the performance of its ceremonies, required other arrangements in the edifices dedicated to it. For its numerous and splendid processions, was provided a long, narrow and lofty gallery, called the naive ; for the reception of the multitude to witness these, adjacent wings were added, called aisles. A choir was added for the actual performance of the sacred rites ; and numerous chapels, to commemorate the bounty of individuals, were dispersed about the edifice. All these essential appendages necessarily occupied a space of great magnitude, and the figure of the cross, held by the Romish Church in the most profound veneration, was pitched upon to regulate the general form of the building thus constituted. One reason for mentioning these particulars is to show the absolute necessity which thus arose for a degree of science and mathematical knowledge not dreamt of by the architects, whose works are received as the sole standards of excellence, by most of the professors of modern times. The narrow intercolumniations of the Grecian buildings would have been ill adapted for the display of feudal magnificence, and the stones within the reach of the builders were far too small to cover even these. Thus the arch became, unavoidably, a prominent feature in the style. To give greater magnificence to the nave, it was made a story higher than the aisles, The wall of this upper story is supported by large piers, which divide the nave from the aisles. The upper, or clear story, as it is called, has windows answering to those beneath. To form an interior roofing, which should at once hide the timbers above, and furnish an appropriate finish to the architrave, the same contrivance was resorted to ; and from this cause have proceeded those vast monuments of daringingenuity, which, while they excite the admiration, have baffled the rival attempts of modern architects. discriminating between its several styles, to explain some of its leading principles, and those particulars in which it more especially differs from the better known principles of Greek and Roman architecture. Of these, the first in importance is the pointed arch, of which there are three kinds. 1. The simple pointed arch, which is struck from two centres on the line of the impost. 2. The Tudor arch, or that which has four centres, of which two are on the line of the impost line, and the other two at any distance. 3. The ogee, which has likewise four centres, two on the impost line, and two on a line with the apex, the segments struck from which are reversed. This form is used only in tracery, or small work, except as a canopy, or drip-stone, over doors and windows. The pointed arch differs from the semi-circular, as employed by the Romans, besides its forai, in having its soffit occupied by mouldings of various projections, instead of being flat, enriched with panels. The cause of this is its great breadth, having frequently to support a wall and roof, which required the piers to be of corresponding magnitude, to diminish the unpleasing effect of which, the architects surrounded them with slender shafts. The projections of these being carried into the arch, caused it to be of the form in question. It is scarcely necessary to add, that these piers are always undiminished. Arising from the general use of the arch is that of the buttress. In Norman work, this was avoided by the employment of walls of vast . thickness, with very small windows ; but when architecture began to assume a lighter character, the windows were enlarged and the thickness of the walls diminished. To compensate for this deficiency, the buttress was employed at once to resist the pressure of the arches within, and to prevent the necessity of the walls being of an unwieldy thickness. These are often divided into stages, each being of less projection than that beneath it, finished by pinnacles; and from the upper part of them spring insulated arches, serving as a projection for the clear story. accompaniments. When square-topped it is called a tower, which is often crowned with a spire. Slender and lofty towers are turrets, and are commonly attached either to the angles of a large tower, where they frequently contain staircases, or to the angles of a building. They are sometimes surmounted by spires, a beautiful example of which may be seen at Peterborough cathedral, in the turret at the northwest angle. In this exquisite and unique design the turret is square, and decorated at the angle with boltels, which are carried up beyond it, and finished by a triangular pinnacle. The spire in the centre is octagonal, and rectangularly placed within the square, four of its sides thus forming triangles with the angular boltels, which, being arched over, form grounds for pinnacles of the same form, which are carried up to about half of the height of the spire itself. The effect is beautiful beyond description, and merits the most attentive examination. Next in importance are the windows of Gothic architecture ; but, as these differ so widely in the several styles as to form the readiest criterion for distinguishing them, they will be more properly noticed when we speak of these styles. We shall pursue the same plan with doors and other subordinate parts. 1 It may be proper, in this place, to say something of the mouldings of Gothic architecture. Of these, that which bears the most resemblance to the Roman mouldings is the ogee, distinguished by the same name, or that of cyma-reversa, in the nomenclature of the Italian school. A moulding used for the same purpose as the cyma-recta, and much resembling it, is also found, more frequently, perhaps, than any other. That which is most peculiar to the style is the boltel, or cylindrical and nearly detached moulding, often answered by a corresponding _ hollow. In the plate are delineated two forms of exterior drip-stones. (Plate 41, Cap figs. 4 and 7.) Rickman, the only writer who has attempted to give a clear and practical account of this beautiful, though neglected style. He distinguishes 'three variations, which may, without impropriety, be called the orders of Gothic architecture; differing, however, from the Greek and Roman orders in this particular circumstance, that while those are confined to one part of a building, or, at most, affect the rest only in regard to strength or delicacy, these extend through every part of the edifice. The first style, denominated by Mr. Rickman "Early English," commenced with the reign of Richard L, in 1189, and was superseded by the next, in 1307, the end of the reign of Edward I. It is principally distinguished by long, narrow windows, and bold ornaments and mouldings. The window, being so essential a mark of the style, claims to be considered in the first place. The early English window is invariably long and narrow ; its head is generally the lancet, or highly-pointed arch, but it is sometimes formed by a trefoil. In large buildings there arc generally found two or more of these combined, with their dripstones united. Three is the usual number, but sometimes four, five, seven, and, in one instance, — the east end of Lincoln cathedral, — eight are employed. When combined, there is usually a quatrefoil between the heads, and where there are many the whole is sometimes covered by a segmental pointed drip-stone, to which form the windows are adapted, by the centre one's being raised higher than the rest, which are gradually lowered on each side to the extremity. Sometimes, in late buildings, two windows have a pierced quatrefoil between them, and are covered by a simple pointed areh as a drip-stone ; thus approaching so nearly the next style as not to be easily distinguished from it. This arrangement may be seen in the nave of Westminster Abbey. In large buildings, the windows arc frequently decorated with slender shafts, which are usually insulated, and connected by bands with the wall. A fine example of this may be seen at the Temple Church, London, one of the purest buildings existing of this style. The circular, rose, or catharine-wheel window is frequently found in large buildings of this style ; in which, however, it did not originate, being found in Norman edifices. It appears to have received much attention from the architects of this period, being worked with great care. The doors of this style are distinguished by their deep recess ; columns usually insulated in a deep hollow, and a simple pointed arch, nearly equilateral in the interior mouldings, but in the exterior, from the depth of the door, approaching the semi-circle. They are also frequently ornamented by a kind of four-leaved flower placed in a hollow. In large buildings they are often divided by one or more shafts (clustered) in the centre, with one of the circular ornaments above. To the steeples of this period were added, in many instances, spires, many of which are finely proportioned, and form a very characteristic and elegant finish to the buildings they accompany. They have usually ribs at the angles, which are sometimes crocketed and in some instances they are still further enriched with bands of quatrefoils round the spire. The towers are usually guarded at the angles by buttresses, but octagonal turrets are sometimes met with, surmounted by pinnacles of the same plan. In small churches, the slope of the spire sometimes projects over the wall of the tower, which is finished by a cornice, and the diagonal sides of the spire, generally octagonal, are sloped down to the angles. The arches of this style are chiefly distinguished by very numerous, though, for their size, bold mouldings, witlr hollows of corresponding depth. The lancet arch is chiefly used, though'many are found much more obtuse. The form of the arch indeed, as Mr. Rickman observes, is by no means a criterion for the dimensions of the styles, each form being met with in buildings of each style, except the four-centred. The piers are distinguished from those of the other styles, by being surrounded with bands which sometimes are confined to the shafts, and sometimes are continued on the pier. The capital is usually composed by plain bold mouldings, one of which is shown in the plate 41, figs. 4, 7, where is also delineated a base of this style ; figs. 6, 9. The plan of these piers is shown in figs. 2, 5, of the same plate ; the shaded part representing a section of the shaft, and the outline, a section of the base. A beautiful variation from Salisbury cathedral is seen in fig. 8. The buttresses of this style are chiefly distinguished by their simplicity, having very few sctts-off, and very rarely any ornament in their places. Frequently, indeed, as in Wells cathedral, a very early example of this style, they retain the Norman form, of very broad faces with slight projections, with a shaft inserted in the angles, and are continued no higher than the cornice. The flying buttress was not used till late in this style. The ornamental parts of the style now remain to be considered, which, till near its conclusion, were but sparingly used, and those, for the most part, of a very rude description. In the west front of Wells and Peterborough cathedrals may be seen specimens of the taste of the period in these particulars, which are wholly unworthy of imitation ; but in the interior of Salisbury are many details, late in the style, which are very elegant, and will bear the most minute examination. It may be sufficient to mention, that in all the ornamental and minute details during this period, as well as in more important parts, the boldness and contempt of refinement, which are infallible marks of an early age, are very apparent ; for which rea via we shall defer the description of many ornamental details, which, nevertheless, were practised, and with success, in the latter part of this period, till the next style in which they were brought to perfection. There is, however, one ornament peculiar to this style which it is necessary to notice, before we proceed further. It resembles a low pyramid, the sides of which are pierced in the form of curvilinear triangles, bending inwards. It is usually placed upon a hollow moulding, from which it is sometimes detached, except at the angles. It has, as yet, received no regular appellation, on account of its being so unlike any other object as to be described, or even delineated, with difficulty, and we believe it must be seen to be accurately comprehended. The only attempt at designation it has received is, the toothed ornament. The reason for applying such a name to it we leave for the ingenuity of the reader to discover. The Early English style of Gothic architecture may, we think, without impropriety, be compared to the Doric order of the Greeks. Like that, it is the first attempt of a people emerging from barbarism ; and, like that, it possesses all those qualities which it is natural to expect from such a state of society. Strength and simplicity are its predominating characteristics ; ornament, except the more bold and artless, is foreign to its nature, and can never be introduced with propriety. For this reason, it may be employed with great advantage in churches, where the saving of expense is an object ; as a finer effect may be produced by the use of this style than of any other whatever for equal expense. Of the fitness of Gothic architecture for ecclesiastical edifices, we presume it is now needless to say much. The circumstance of its having had its origin in Christian worship, and its consequent adaptation to its ceremonies, its fitness for the climate, and its devotional effect upon people in general, seem to point it out as peculiarly appropriate for this service. In exterior effect Gothic architecture is very defective, and never more so than in this style. We have, indeed, scarcely one front which is at all reconcilable with good taste. That of Salisbury cathedral is generally admired, but we can see no reason for the preference. A consciousness of this defect of the style led . the architect of that of Peterborough cathedral to make use of a singular expedient. Three ponderous arches, supported by triangular piers, receive the weight of three gables, and at each lateral extremity is a square turret, containing a staircase and surmounted by a spire, such as has already been described. The effect of the composition is grand, but it is not worthy of imitation. A field is thus offered for the exercise of modern invention, which, as this kind of architecture is better understood, it is hoped will not be neglected ; much has been done, but something, we conceive, The style next in order to the Early English is denominated by Mr. Rickman Decorated English, as possessing a greater degree of delicacy than the former, without the excessive detail of the style which succeeded it. It ceased to be used soon after the death of "Edward III., which happened in 1307. Its prominent feature is also found in its windows, with which, therefore, we shall commence our description. The windows of this style are distinguished from those of the last by being larger, and divided into lights by slender upright stones, called mullions. Of decorated windows there are two descriptions. 1. Where the mullions branch out into geometrical figures, and are all of equal size and shape, and, — 2. Where they are dispersed through the head in curves in various descriptions, which is called flowing tracery, and are usually in windows of more than three lights, of different size and shape, the principal mullions forming simple figures, subdivided by the inferior ones. Sometimes the principal mullions are faced by slender shafts, with bases and capitals. The first description is considered the oldest ; the principal example which contains this kind of window is Exeter cathedral, where they are very large, and nearly all composed of this kind of tracery. The flowing tracery, which composes the greater number of windows of this style, will be better understood by reference to the plate than by any description we could give ; a small one is delineated at plate 42, fig. 1, of which the form is copied from one at Slcaford church, Lincolnshire. A specimen of the application of the same feature to larger windows may be seen in the view, in which the small one forms part of the composition. The architraves are commonly enriched by mouldings, which sometimes assume the form of columns, and the windows in composition frequently reach from pier to pier. The form of the arch is seldom more acute than that described on the equilateral triangle, and it is generally more obtuse. The richness of these windows invariably depends upon their size, the distance between the mullions being nearly the same in all ; the largest, however, do not consist of more than nine lights. The drip-stone is, in this style, improved into an elegant canopy, the form of which is sometimes pedimental, and sometimes an ogee arch. It is decorated with crockets and a finial, and the space enclosed by it, and the exterior contour of the arch, is sometimes rilled with tracery. The great west window of York cathedral, one of the finest in Great Britain, has a triangular one. The circular window was also bfought to perfection in this style. A fine example in form, though not in detail, is now all that remains of the ancient palace of the Bishops of Winchester in Bankside, Southwark. This is of the geometrical description ; one of the finest of flowing tracery is in the south transept of Lincoln cathedral. The doors of this style are not so distinct as the windows from those of the former period ; double doors are not so frequent, and the shafts are not detached from the mouldings, as in the Early English. In small doors there is frequently no column, but the mouldings of the arch are carried down the sides without interruption ; there is frequently no base moulding, but a plain sloped face to receive the architrave. They are surmounted by the same sort of canopies as the windows. The steeples of this period arc distinguished from those of the last in little more than their windows, and a few unimportant details. The north-west spire of Peterborough cathedral, before described, decidedly belongs to it, though the tower beneath is Early English. The tower and spire of Newark church, Lincolnshire, are pointed out by Mr. Kickman as a peculiarly fine example. The groining of the ceiling will be understood by referring to plate 41, where the groinings are seen springing from upper part of the caps, figs. 4 and 7. Fig 4 is the groining of the nave of York cathedral, the purest example of equal richness. THE DECORATED ENGLISH STYLE. 51 Most frequently, however, the nicely-decorated ribs are omitted, and the rib from pier to pier, with the cross springers, and the longitudinal and transverse ribs only are employed. At the intersection of these, bosses, or sculptured ribs, are almost invariably placed. The aisle-roofs are very rarely enriched with superfluous ribs, but those of RedclifF church, Bristol, are elegant exceptions. Of arches little can be said. Of their forms it may be sufficient to observe, that the lancet arch is rarely to be met with ; the Tudor never, but in one instance, — the nave of Westminster cathedral, — built, or rather cased, by the celebrated William of Wyckham ; and it is here necessarily adopted on account of the form of the Norman arch it was employed to conceal. The mouldings are in general less numerous, and, consequently, less bold than those of the preceding style. In small works the ogee arch is frequently found, and decorated with crockets and a finial. One of these is shown in plate 42, fig. 2. The piers of this style are, for the most part, square in their general form, and placed diagonally; two variations of these are shown in the plate 41, figs. 6, 9. That marked 3 is from Exeter cathedral, and 6, from the nave of that of York ; both are pure and beautiful examples. The shafts are sometimes filleted \ that is, a square and narrow face is continued vertically along its surface, projecting slightly from it. The capitals are frequently enriched with foliage, and the bases, in many instances, consist of reversed ogees, with square faces of various projections, and sometimes other mouldings. Derated English buttresses are distinguished from those of the last style, which are most applicable to it, only by their greater richness, in buildings where decorations are not spared ; and, consequently, in others they arc perhaps the least characteristic parts of the composition. They are, however, usually finished by pinnacles, Avhich are generally distinguished from those of the former style. The flying buttress is almost invariably used, and also surmounted by a pinnacle, which usually corresponds with the lower one. The buttresses of the aisles port they afford to which is by the arches which connect them with it at the top. The parapets of this style are sometimes horizontal, and sometimes embattled, each of which is frequently pierced in the form of cinquefoil headed arches, quatrefoils and triangles. Sunk panels are, however, more common. When plain embattled parapets are employed, the crowning mouldings are usually continued horizontally only, the face towards the opening being merely a vertical section. As many 6f the ornamental parts of Gothic architecture were brought to perfection during this period, they cannot be better introduced than in this place. Among these, the use of crockets is a prominent feature ; these are small bunches of foliage running up the side of the gablet, afterwards improved into the ogee canopy over doors, windows, and ornamental arches, and finished by a combination of two or more, called finial, which is separated from the rest by a small moulding. They are also used to decorate the angles of pinnacles. The upper part of a canopy of this description is shown in plate 42, fig. 2, from which these ornaments will be better understood than from any description. Another peculiarity of Gothic architecture is the feathering of windows, screen work, ornamental arches, panels, and sometimes doors. It is called trefoil, quatrefoil, or cinquefoil, according to the number of segments of circles, which are called cusps, of which it is composed. The method of drawing it may be seen from the window in the plate. A very beautiful door, thus ornamented, still exists in St. Stephen's chapel, Westminster, now the House of Commons. Although the grotesque is the prevailing character of the sculpture employed in the decoration of Gothic architecture, many small ornaments are found, particularly in this style, designed with taste, and executed with the utmost delicacy. They are copied from the beautiful though humble flowers of the field, and are, in many instances, local. THE PERPENDICULAR STYLE. 58 We have compared the former style to the Doric of the Greeks, and the present may, with less propriety, be likened to the Ionic of the same people. Boldness and simplicity characterize the first ; elegance and delicacy, the second. In both Greek and Gothic orders, ornament to profusion is allowable ; yet in neither does it interfere with the composition, and may be entirely omitted. From this circumstance arises a universal applicability, belonging only to the far-famed happy medium, so often talked of, so seldom attained. In grandeur of composition, simplicity of arrangement, elegance of form, and perfection of capability, this style is, therefore, unrivalled, and may be used with advantage for every purpose of civil architecture. It is, however, peculiarly adapted for all churches whose size and situation render them of importance ; and in such large buildings, where Gothic architecture may be thought desirable, as are of sufficient consequence to allow the architect to think of delicacy in the design of his details. The last of the grand divisions of Gothic architecture is the Perpendicular Style, introduced as the preceding fell into disuse, and finally overwhelmed by its own superfluity of decoration and uncompromising minuteness. It was not wholly lost sight of before the reign of James I. , but few buildings were then erected without a mixture of Italian work. The Perpendicular Style, like the others, is most readily distinguished by its windows, whence it also derives its appellation ; the mullions of which, instead of being finished in flowing lines, or geometrical figures, are carried perpendicularly into the head. They are further distinguished by a transom, or cross-mullion, to break the height, under which is usually a feathered arch, and sometimes it is ornamented above by small battlements. The architraves of windows in this style have seldom shafts or mouldings, as in the former, but are worked plain, and, frequently, with a large hollow. Although these windows do not admit of any great variety in the disposition of the tracery, they are far more numerous than those of either of the other styles ; few specimens of which remain that do not bear marks in their windows of the rage for alterations which appears to have prevailed during this period. The doors of this style arc remarkably varied from those of the preceding ones, by the arch's being finished by a horizontal moulding, which is continued down to the springing of the arch, and then shortly returned. This is called a label. The space enclosed by it and the exterior line of the arch is called the spandrel, which is commonly filled with a circle enclosing a quatrefoil and other circular ornaments. The steeples of this style are, for the most part, extremely rich ; spires are seldom met with, but lanterns are frequently used. A lantern is a turret placed above a building, and pierced with windows, so as to admit light into the space below. This is sometimes placed on the top of a tower, as at Boston, and supported with flying buttresses springing from it, and sometimes constitutes the tower itself, as at York, Peterborough, and Ely cathedrals, where it is placed at the intersection of the cross, and has a very fine effect. The exterior angles are frequently concealed by octagonal turrets containing staircases, but are usually strengthened by buttresses, either double or diagonal. A most beautiful finish for a steeple is found in that of the Church of Newcastle-upon-Tyne ; where a small, square tower, each side of which is nearly occupied by a window, surmounted by a spire, is wholly supported by arch buttresses, springing from the pinnacle of the great tower. This is copied by Sir Christopher Wren, in the Church of St. Dunstan's in the East ; which, though in workmanship and detail it is far inferior to the original, excels it in the proportion it bears to the rest of the composition. Groining, in perpendicular work, assumes a new and more delicate character. A number of small ribs, diverging from a centre, are carried up in the form of one side of a pointed arch, and terminated equidistantly from that centre by a semi-circle. As they recede from the point they are divided by smaller ribs or mullions, and these again are subdivided, according to the size of the roof, so as to make all the panels of nearly equal size. These panels are ornamented with feathered arches, &c, in the same manner as the windows, in conformity to which the whole is designed. The intervals between these semi circles are filled with tracery of the same description. This kind of roof is called fan tracery; it is exquisitely beautiful, and almost the only kind of groining used in this style, Another description of roof must now be mentioned, of very different character ; this is the timber roof, of which Westminster Hall presents so magnificent an example. Here the actual timbers of the roof are so arranged as to form an architectural combination of great beauty ; a wooden arch springs from each side of the building, supporting a pointed central one, finished downwards with pendants. The rest of the framing is filled with pierced panelling. This kind of roof is not found in churches ; but it seems well adapted for large halls for public business, or any place intended for the occasional reception of large meetings. The arch, in late perpendicular work, is generally low in proportion to its breadth, and is described from centres ; this is called the Tudor arch, from its having been principally in use under the reign of two princes of that family. Besides this distinction in the form of the arch, there is an important one in the arrangement of the mouldings, which are carried down the architrave without being broken by a capital ; and sometimes there is one shaft with the capital, and the others without. The capitals, when there are any, are generally composed with plain mouldings ; but there is sometimes a four-leaved square flower placed in the hollow. from those of the last style by their extraneous ornaments, if they have any ; the buttresses are sometimes panelled, and in some very late specimens the pinnacles are in the form of domes, of which the contour is an ogee arch. The ornament of the Perpendicular Style is well characterized by the name, many buildings being, as Mr. Rickman observes, nothing but a series of vertical panelling. "For example," says he, "King's College chapel is all panel, except the floor; for the doors and windows are nothing but pierced panels, included in the general design ; and the very roof is a series of them in different shapes." Monotony is inseparable from such an arrangement ; grandeur is incompatible with it, and the appearance of it is a certain prognostic "of decline in whatever is marked by its introduction. A beautiful small ornament, peculiar to this style, is the Tudor flower, which is a series of square flowers placed diagonally, and frequently attached, connected at the bottom by semi-circles ; the lower interstices are filled with some smaller ornament. This is principally employed as a finish to cornices in ornamental work. With whatever justice the preceding styles have been compared with the Doric and Ionic orders of Grecian architecture, the comparison does not hold between the present and the Corinthian. The former is a necessary gradation in the art, and is applicable to compositions of any size. The latter is not necessary, and is unpleasing, except in small works. The change from the graceful forms of the decorated windows to inelegant, artless, straight lines ; the alteration in the form of the arch, which is a deviation from one of the leading principles of Gothic architecture ; and, above all, that inordinate passion for ornament and minutiae, which, like excessive refinement in other matters, is a certain mark of the decay of true taste ; in short, almost every peculiarity in this style indicates approaching dissolution. These circumstances, however, which render the perpendicular style so objectionable for ARCHITECTURE OF AMERICA. large buildings, make it peculiarly appropriate for small and confined parts of a building, such as chapels and domestic apartments, when Gothic architecture is preferred. For the latter purpose, we fear, indeed, it is ill adapted in any shape ; all its peculiarities seem to point at magnificence and imposing effect, with which magnitude is inseparably connected, as their ultimate objects and the most proper field for their display ; and with these qualities it is well known domestic comfort has little in common. The confined space in which the latter can alone be enjoyed is ill reconcilable with the interminable vistas and lofty proportions by many considered as the perfection of the former, It is, however, not only proper, but necessary, in some cases, to employ the Gothic in the decoration of apartments, and where this happens this style is decidedly preferable. It has been truly observed by an ingenious writer on the subject of English architecture, that it can in no case be advantageously blended with the Grecian, differing, as it does, so essentially in its component parts. The Grecian style is designated by horizontal lines supported on columns, and by the entablature and its component parts ; while the Gothic is dependent on perpendicular lines, and arches variously decorated, for the leading feature in its composition, as may plainly appear by consulting the best Grecian examples, and comparing them with the Decorated English, justly bearing the appellation here given by that able writer on this subject, Mr. Rickman. The architecture of our country is at present in a very undefined, Ave may almost say in a chaotic state, though it has, since the commencement of the nineteenth century, undergone much improvement. It is now but about two hundred years — not so long as many of the finest specimens of European architecture have been standing — since a band of Pilgrims, driven by persecution from their native country, landed upon these western shores, and found a vast expanse of wilderness, stretching from one ocean to the other in breadth, and in length almost from the northern to the southern pole. Our country was then literally the new world. It was in a perfect state of nature ; and art had left scarcely a foot-print on its soil. The savage, with barely skill enough to shape his rude bow, to break the flint to a point for his arrowhead, and to peel the bark from the forest-trees for his hut, was its only inhabitant. And those men, who, for freedom of opinion, had fled from civilized Europe, landed here in the commencement of a severe winter, bringing with them but few recollections which could endear them to the things they had left. The hardships and persecutions they had so long endured had chastened their spirits, and imbued them with a formal stiffness and austerity, which manifested itself in all their works, and in nothing more than in the simple severity of their architecture. They appear to have been desirous of entirely obliterating the memory of the magnificent churches and pompous ceremonials attendant on the worship of their oppressors ; and, in the meeting-house of the Puritans, we see not this division of nave, transept and choir ; chancel and altar are lost, as well as the clustering columns and intersecting arches, which seem as if v 'Twist poplars straight the ozier wand In many a prankish knot had twined ; Then framed a spell when the work was done, And changed the willow wreaths to stone." Those beauties of England's Gothic churches, as well as the more chaste and simple, and yet more enduring elegance of the Grecian temples, were never copied by them. And there were other reasons why the beauties of ornamental architecture have, in our country, been so long neglected. The landing of the Puritans on our shores made an era in the annals of the world, a luminous point in the path of civ- ilization, whence we may date the commencement of an age; and the spirit of this new age is an enterprising spirit. Men leave their homes, plunge into the dense forest, find a stream whose banks, perhaps, the foot of a white man never before trod, erect a mill whose plashing wheel and vrhizzing saws soon tell that the forester's axe has found work abroad ; and the. mill, in turn, makes busy the echoing hammer, which now reigns throughout the village, from early morn to dewy eve ; and, in a few days, we may say, a mimic city has arisen, where no dwelling" but the Indian hut was ever before seen. True, it is a city of shingle palaces, erected to endure but for a generation. But the spirit of the age is locomotive. The people of this age are a transient people, flitting from place to place ; and each builds a hut for himself, not for his successors. Railways and canals are fast spanning the continent. Our sons and daughters live abroad, and look out for rapid vehicles rather than abiding dwelling-places. Naught is here heard of those immense fortunes which have been accumulating for centuries in one family, and which, invested in massive castles or gorgeous palaces, with park and forest, have descended, entailed, from generation to generation, and been renewed, added to, and beautified, by each successive occupant. Fortunes are here, as it were, made and lost in a day ; and funds invested in real property, though safe, are slowest in turning. Indeed, building has never been a favorite mode with our people for investment ; and domestic architecture has, therefore, suffered much. But it is already beginning to improve, as many chaste and beautiful specimens in our immediate neighborhood testify. This spirit of improvement, however, is principally manifested in the designs and materials of our public buildings ; among which we have many that might challenge the admiration of the European connoisseur. We want not now for models to be found in our own country of the purest Grecian, or the more beautiful Gothic; and surely we want not for materials. Among our public buildings, the Capitol at Washington is deserving of notice. Simple and elegant in its interior, its exterior is beautiful and imposing. The domes over the wings rise with an elegant and graceful curve, and may be considered almost perfect specimens of that most difficult branch of ornamental architecture. Were the same graceful elevation given to the centre dome, it would add much to the beauty of the building. In Philadelphia we have the United States Bank, a faultless specimen of the pure Doric ; classic, chaste, and simple in its proportions, it is a building of which we may well be proud. Philadelphia may also boast of her Exchange, and the Mint ; both of which, built of white marble, in a style to suit the material, have a very imposing appearance. The Girard College, at Philadelphia, is a magnificent specimen of the Corinthian order. The Custom House, at New York, built of white marble in the Grecian style, is the finest building in the city ; and the new building for the University is a beautiful specimen of the Gothic style. In Boston we have many beautiful buildings, but few of pure architecture. Trinity Church, in Summer-street, is built of rough granite in the Gothic style. The front is beautiful, massive and imposing in its appearance, but the sides belong to an age of the Gothic different from the front ; the interior excels that of any other church in our city in beauty ; the walls painted in fresco, the graceful and well-proportioned clusters of pillars, the oaken wood-work, and the ornamented chancel, give it a magnificent appearance. But the central arch of the roof is altogether out of proportion, and, if constructed of any heavy material, could not support its own weight ; it certainly adds no beauty, but rather takes from that of the other portions. The new building for the Library, and the Unitarian Church, at Cambridge, are among our best specimens of Gothic architecture, and we can only wish the church had been built of more durable materials. We have many graceful and elegant spires, both upon our city churches and those in our vicinity. That of the Federal-street Church, which is built in the Gothic style, is a model much to be admired. Among our specimens of Doric worthy of mention, are the new Custom House, the United States Branch Bank, the Hospital at Rainsford Island, the Washington Bank, and Quincy Market, a plain but noble structure of hewn granite, about five hundred feet in length, constructed by, and an honor to, our city. The Stone Chapel, at the corner of School and Tremont streets, is our oldest specimen of the Ionic order. We have also, of the same order, St. Paul's Church, the Suffolk Bank, and Tremont Temple. The facade of the Temple is chaste and dignified. The front of Central Church, in Winter-street, and the rotunda of the Merchants' Exchange, are of the Corinthian style. .We have already trespassed on the limits usually assigned to a preface, but we hope not unnecessarily so. Want of space prevents our saying as much on domestic architecture as we would wish, in this part of the volume. But that is a branch of the art which is yet in its infancy among us, and a part upon which, if we should -only write a page or two here, the little contained in that page or two would only serve to show the need of more. We would only suggest, that, in constructing a dwelling-house, the convenience and comfort of the interior should ever receive more attention than the exterior elegance and symmetry ; and that the beauty of a private house consists not so much in the nearness of its resemblance to a Grecian temple, a Chinese pagoda, or a Gothic church, as in its fitness for the purpose for which it is designed. It is necessary, above all things, to remember that houses are made to live in, and the convenience of their inmates is the first thing to be considered ; after that, ornament may be added. It has been our design, in preparing this work for the press, to add the little in our power towards establishing a pure and correct taste in our domestic architecture ; and, if we have succeeded in that, we shall consider ourselves more than repaid, in the sense that we have done our duty in paying the debt which every man owes to his profession. We now offer a few remarks on Domestic Architecture. With respect to the situation of a house, where choice is allowed, it is obvious that the most desirable must be that which combines the advantages of pure air, and protection from cold winds, with a plentiful supply of water, convenient access, &c. As these observations, however, must present themselves to every one, we shall not here dwell upon them, but proceed to consider those essential parts of a house, rooms. And, first, their effect uponthe exterior figure of a house. The form which gives the largest area with the least circumference is evidently a circle ; but this figure, when divided into apartments, is very inconvenient, from the numerous acute angles and broken curves which must necessarily compose them. Nearly the same objections apply to the triangle, which has the further disadvantage of occupying a smaller area with respect to its circumference than any other figure. Rectangular forms, therefore, are best adapted for houses in general ; since, within them, the divisions of apartments may be made with the greatest regularity and least waste. As rectangles are most readily divided into rectangles, this is also the figure which may be employed to the greatest advantage in the rooms themselves. As to the proportions of these, the length may range from one to one and a half breadth. If larger than this, the room partakes too much of the gallery form. The usual rule for the height of a room is, if it be oblong, to make it as high as it is broad ; and if square, from four-fifths to five-sixths of the side is a good proportion. With regard to health, however, no room should be less than ten feet in height. It is obvious, that on a floor where there are many rooms, they must be of various sizes, and to regulate them all by architectural rules avouH be productive of much inconvenience. As, therefore, the apparent height of a flat ceiled room is greater than that of a coved one of equal altitude, it is usual, in these cases, to make the larger rooms with flat ceilings, and the smaller ones Avith. coved or domes. Apartments of state of unusual size may occupy two stories. With regard to the decoration of- ceilings, a great diversity of taste exists. At one period, no ceiling was thought to be sufficiently ornamented unless it was covered with paintings, chiefly representing allegorical subjects. This taste was carried to a great excess, and was the subject of much ridicule. Of late years, ornament of any description has been thought superfluous, and the ceiling has been usually left completely bare. This is, however, giving way to the geometrical decorations prevalent during the middle and latter part of the last century, which certainly give an enriched effect to a room, and possess this advantage over every other method of decoration, that they are capable of any degree of simplicity or richness, both in form and detail, according to the size of the apartment, or quantity of decoration in it. For rooms which are small, and the ceiling consequently near the eye, these ornaments should be delicately worked ; but in those of larger size they require to be bolder. The angles formed by the ceiling and walls are concealed by cornices, the enrichment of which will of course depend upon the delicacy or simplicity observed in the embellishments of the room. The proportion for doors is somewhat over twice the breadth in height, as three and seven feet. Entrance doors, throe, four and seven feet. In case of larger doors, for folding or sliding in partitions, or those for public houses, they should vary according to the height of stories, where they are required not to exceed twelve feet in width Doors for apartments should be as near the centre of partitions as convenient For a suite of rooms, the doors should be nearly opposite ; but in no case should they be placed near the fireplace, or so as to open opposite the bed, excepting those which connect the dressing-room with the bed-chamber. The usual method of ornamenting doors is to finish the two sides and top with architraves, or fancy pilasters — corner block at the upper angles — or an entablature, frieze, and cornice ; outside ones with pilasters, or attached columns, entablature, and cornice. It is obvious that, in arranging the windows of an apartment, it will first be necessary to decide on the quantity of light required to be admitted. Sir William Chambers observes that in the course of his own practice he has generally added the depth and height of rooms on the principal floors together, and taken one-eighth ptart thereof for the width of the window. The height of the aperture in the principal floor should not much exceed double the width. In the other stories, they are necessarily lower in proportion, the width containing the same. The windows in modern houses are frequently brought down to the floor, in imitation of the French ; but where this is not the case, the sills should be from two feet four to two feet six inches from the floor. The windows of the principal floor are generally the most enriched, and the usual manner of decorating them is by an architrave, surrounding them with a frieze and cornice, and sometimes a pediment. When they are required to be more simple, the frieze and cornice are omitted. In a front, the pediments are, for the sake of variety, often made triangular, and curved alternately, as in the banqueting-house at Whitehall. hires, the centre one being arched. The usual mode of executing this is by dividing the apertures by columns, and placing corresponding ones at the extremities of the opening ; the side apertures are covered by an entablature, and the centre by a semi-circular architrave, of which the entablature forms the impost. In modern times, they are finished without columns and impost moulding, or arch, but have a straight cap ; the centre, three lights wide, and one on each extremity. and its decoration. With respect to the situation of chimney-pieces, we have already mentioned that they should be sufficiently removed from the door. Sir William Chambers further advises that they should be "so situated as to be immediately seen by those who enter, that they may not have the persons already in the room, who are seated generally about the fire, to search for." Whether the worthy knight had experienced personal inconvenience from a maldisposition in this respect, we cannot tell, but do not conceive it to be an evil of the first magnitude. The standard proportion of the chimney-piece is a scuiare ; in larger rooms somewhat lower, and in smaller, a little higher ; its size will, of course, depend on the quantity of space to be heated, but the width of the aperture should not be less than three feet, nor more than five feet six inches. When the size of the apartment is considerable, it is better to make two fireplaces. In the decoration of chimney-pieces, the utmost wildness of fancy has been indulged, but it is certainly proper to regulate their ornaments by the style of the building to which they belong. Those in which the Roman style predominates are designated much in the same manner as the windows, except where magnificence is attempted, in which case caryatides, termini, &c, are employed. In modern taste little is done by way of decoration ; their richness consists principally of beautiful specimens of variegated marble columns or pilasters, and entablature. " Staircases," says Palladio, " will be commendable if they are clear, ample, and commodious to ascend, inviting people, as it were, to go up. They will be clear, if they have a bright and equally diffused light ; they will be sufficiently ample, if they do not seem scanty, and narrow, to the size and quality of the fabric, but they should never be less than three feet in width, that two persons may pass each other; they will be convenient in respect to the whole building, if the arches under them can be used for domestic purposes ; and, with respect to persons, if their ascent is not too steep and difficult, to avoid which, the steps in breadth should be nearly once and a half the height of the rise." In modern dwellings the number of the steps depends on the height of the story they are intended to ascend, as galleries of less height are omitted for convenience of room and style of composition. The rise should not -exceed eight inches, nor be less than six inches in height ; their top surfaces are sometimes inclined, for greater ease in ascending. The ancienls were accustomed to make the number of steps of an odd number, that they might arrive at the top with the same foot that they began the ascent with ; this arose from a superstitious idea of devotion in entering their temples. Palladio directs that the number of steps should not exceed thirteen before arriving at a resting-place ; the present number of steps in flights is between thirteen and nineteen. Staircases are either rectilinear or curvilinear in their forms ; the former are most usual in dwelling-houses, as being more simple, and, in general, executed with less waste of material ; but the latter, which may be either circular or elliptical, admit of greater beauty, if large, and greater conveniency, if small. Small staircases of this description are generally circular, and have a column, called a newel, in the middle ; they are constructed with great simplicity, the newel being composed of one end of the successive steps, while the other rests in the wall. They are found in all our country churches. When ornament is studied, the steps may be made curved, which has a very pleasing effect. Modern staircases are finished with a newel at the foot of the first step, from six to eight inches diameter, richly carved. Where ample room is allowed, it is usual to put on a curtail step and scroll-rail, supported with an iron newel, and up the rail are several iron balusters to secure the same. In large designs, however, the elliptical is generally preferred, and is capable of very grand effect, which Sir William Chambers has sufficiently shown in one of the staircases at Somerset -Place (that belonging to the Royal Society, and Society of Antiquaries), which, without any superfluous decoration, is a design of uncommon magnificence, and excelled by few of the kind. The newel being of a very unpleasing form in this kind of staircase, is an objection to its use where it is of a small size. Those staircases which are open in the centre are generally lighted from the top, but where this is impracticable the light is admitted by windows in the most advantageous position the situation will allow. PLATES. I have here made use of the Grecian example, given by Vitruvius, from the temple of Minerva, on the Acropolis at Athens, built under the administration of Pericles, the representation of which is found in Fig. 1 . The proportional figures from the scale of the column. Divide the lower end into two equal parts; each is called a module; divide the module into thirty parts, which are called minutes as figured on the order ; under the column H is the of the mouldings inside of the portico. Fig. 2.' A section of the column at both ends, with twenty flutes and the manner of striking them : divide the circumference into twenty equal parts ; trace lines to the centre ;( with the dividers draw a line, for the circumference of the top, intersected by the radius a, b; extend the dividers from c to d, and for the circumference of the lower diameter, to g; and from e, describe the curve for the flute e,f; and, in like manner, for the upper diameter, as shown by g, e, f. GRECIAN DOBIC. each will not materially differ ; but, on the outside of buildings, the breadth may be fifty-five minutes ; on the external angles of porticos, they may be twenty-seven and a half minutes each, and leaving twenty-four minutes between the shaft ; this will have a very good effect in large works. The projections from the wall are onefifth, and, when inserted disconnected with columns, one-fourth to one-half may be the- projections ; when the composition is purely classical, one-haTf will be in the best taste. fig. G. Fig. 2. A vertical section showing the return of pilaster, panel, projection of imposts, doors, &c. : b, the threshold ; a, a, a, steps, &c. ; j, the return of pilasters ; c, the panel and recess ; d, the ceiling and the recess, with moulded panel ; p, the architrave and width of soffit ; /, the frieze of entablature ; g, the portion, backing up from stone-work, shown by dotted lines ; e, the floor timber, fastened by timber-clasps. Fig. 1. The elevation of interior door. This style of inside doors, although very plain, is much admired on account of the smooth surface for paint, the durability, and the ease with which it is kept clean ; thereby rendering it one principal reason for adopting it for common use. Drawn one inch to a foot ; H, the architrave, with Fig. 1 is a horizontal section of a window-frame, designed for a frame-house, with board and sheathed walls, the outside casing flush, the blinds shut flush with the casing ; and, when painted a stone-color, has a very pleasing effect for a Doric house, and, at a little distance, resembles stone in color, as well as in the style of finish. A, the pulley-style ; B, rough boarding ; C, outside casing ; D, stud ; E, parting-slip ; F, parting-bead ; G, sash and blind-stop ; H, sash-bead ; I, inside casing ; J, back lining ; K, furring ; L, shutter-stop ; M, lath and plastering ; N, pilaster or architrave ; 0, 0, shutters. Fig. 2. A section of a window designed for brick or stone wall : a, brick wall ; b, outside moulding ; c, outside casings ; d, pulley-style ; e, parting-slip ; /, parting-bead ; g, sash-bead ; h, box-casing ; i, back-casing ; j, furring ; k, edgecasing ; I, ground ; m, lath and plastering ; n, architrave. Fig. 3. a, soffit-bed ; b, top sash-rail ; c, style ; d, sash-bead; e, outside of box; /, wall moulding ; g, g, meeting rails ; h, bottom-rail ; i, i, middle rails ; j, wood sill ; k, stone sill ; C, back. Fig. 3. A portion of the style, fall thickness : a, style ; b, brass plate, the dotted semi-circle, the ^portion of wood hollowed out ; c, the perforation through the plate to admit the pivot at the end of d; d is a circular drop extending the entire- width of the fold, each end playing in a plate each side, the pin or pivot to play loosely, as the plate d, by opening or shutting, is moved over the sill ; and, as the sash closes, the plate d drops in and rests on the bottom, and cuts off the pressure of wind and water ; e, the rabbet. Fig. 1. A geometrical elevation of a Grecian Doric house, on a scale of fifteen feet to an inch, designed for a gentleman's residence, in our republican country. The site is on the summit of a gentle eminence, which gives to it a peculiarly picturesque view, and a free circulation of air. Fig. 2. The first floor : a, the entrance hall ; b, b, parlors, with slide-doors ; c, sitting-room ; d, china-room ; e, dining-room ; /, back staircase ; g, principal staircase ; H, //, chimneys ; 7, I, I, I, columns of portico. It is intended to have the kitchen, pantry, store-room, &c, under the dining-room ; in such cases, it will be necessary to open an area on the outside, eight feet wide, the whole length of the back side, with steps down at each end, and a back entrance to the same. SPECIFICATION. The excavation should be sufficient to admit the passage of workmen both sides of the walls, and to secure an equal density of bottom, either by beetling, by inverted arches, or by driving piles ; in most cases, the beetling only will be necessary, especially in a location like this. The first course should he two and a half feet broad, and one foot deep, with stones as long as convenient ; the other courses, rising to within four inches of the intended grading of the ground, may be one foot ten inches in thickness, and properly levelled, the inside faced to batter one inch. Thickness of wall, one foot. Thickness of pilasters, six inches. Outside wash, one and a half inch. Top of underpinning projects one inch. The wall of the building, on the area, should be fine hammered granite, one foot nine inches thick, with splays, or bevels, cut for window-shutters ; this wall should be perpendicular, faced on both sides ; -the bank wall for the area, at least three feet thick at bottom, faced up inside to batter one inch, five feet in height, and topped with a fixed stone for iron work ; to have one flight of hammered granite steps at each end of the area ; at the upper back entrance of the house, a stone passage over the area six feet wide, with cast-iron fence each side, and five steps to descend to the lawn ; buttresses for front dopr-steps, three feet six inches high, to project from underpinning five feet ten inches, being one foot eight inches thick ; five steps, six and a half feet long, eight inches rise, and one foot two inches in width of steps ; project from the underpinning of end wall of house eleven feet six inches ; the buttresses at the ends of porticos, three feet two inches broad, three feet six inches high, eleven feet six inches long. Steps, thirty-six feet two inches long, eight inches rise, one foot two inches tread ; the floor of porticos of fine hammered granite ; if convenient, make the length and breadth in one stone, thirty-six feet two inches long, and eight feet wide ; or if not, divide the length into three equal parts. The walls of principal, second, and attic stories, of fine hammered granite stone facings, from four to six inches thick, in regular courses, sixteen inches wide, of proper length ; beds and bells hammered ; returns, quoins and ravines, lined or backed up with bricks, making the thickness one foot ; iron damps inserted in each of the horizontal joints, once in three feet in length. For details of caps, entablature, cornice, &c, see plates for the same ; gutters, sheet copper ; battlements, stone. The roof is intended to be covered with galvanized iron or tin — either will answer a good purpose ; copper trunks on the inside of the walls ; chimneys laid up as per plan, plate 9, fig. 2 ; brick trimmers turned ; hearths all laid ; marble slabs for first and second stories ; marble tiles for the attic. Chimney-pieces for parlors, cost fifty dollars each ; for dining and sitting rooms, forty dollars each ; for chambers, twenty-five dollars each. Lay up brick partition walls in the cellar. Partitions of entrance-hall to rest on the same, piers and arches for chimneys ; lathing and plastering. First floor, plank, two by twelve inches. Trimmers, three by twelve inches ; floor plank, sixteen inches from centre to centre. Second floor, two by eleven inches ; the second and attic, distance as on the first floor ; frame partitions fitted for twelve-inch nailings. Studs, three by four inches ; proper trusses and doorjambs ; the roof framed with trusses to support covering ; joists not exceeding seven feet for the bearing ; the trusses to extend transversely across the building ; the centre ridge to rise four feet above the gutter at the eaves. The covering joists, or rafters, three by five inches, not to exceed two feet apart, and spiked on transversely over the trusses ; the portico's roof to have two sections of rafters, each joist four by FLOORS. The under floors, straight edges well nailed down, to be deepened by plastering three-fourths of an inch thick, with screeds to level the same ; the screeds to be taken out, and the space filled with mortar after the first plaster is dry, to preserve the mortar from giving away ; cover the top with a thick coat of paste, and a layer of thick paper ; it will, when dry, produce a hard surface ; then lay the top floors, for the best rooms, with one and a half inch clear lumber, not to exceed six inches wide, grooved and tongued, perfectly seasoned, to be keyed up and blind-nailed ; the other floors laid with inch boai-ds got to a width and thickness, properly laid level and smoothed. FURRING. All of the Avails, ceilings and partitions, to be furred for one foot nailing. The furrings for the windows with shutters, in first and second story, are to be one and three-fourths inch plank ; the jambs for doors and windows, to have suitable ground. The Avails, plastered down to the under floors. WINDOWS, To have box-frames double hung, for all except the French Avindows, first story, in the porticos ; those to sAving in two parts, each one light in width , see plate 8, figs. 1, 2, and o ; the thresholds rabbetted — see e, fig. 3 ; the Avidth of opening, three feet six inches ; the other Avindows three feet four inches ; twelve lights each, cherry-Avood sash ; first story, glass, twelve by twenty inches ; second, twelve by sixteen ; the attic, eleven by fifteen. For the first two stories, provide, hang, and fasten box-shutters and sash ; also box-shutters for the kitchen, fourfold, hung in two parts ; the French AvindoAvs, cherry sash-frames, properly hung, Avith butt hinges ; in the kitchen, stool casings, also stool and edge casing in the attic story ; the first and second stories to have backs, elbows, back-linings and soffits, panelled shutters, pilasters for window and doors ; first story with cap, pilasters, &c. The outside ones two inches thick, three feet four inches by seven feet four inches ; inside, first story, three by seven feet ; one and three-fourths inch thick. Second story, two feet ten inches by six feet ten inches, one and a half inch thick ; all doors two panels. See plan of door, plate 5. Butt hinges and mortise locks for all the doors ; cut glass knobs for doors and shutters of the first and second stories ; for attic and kitchen, rosewood knobs. The average price of Robinson's locks is one dollar and twenty-five cents. Pilasters, first story in regular proportions, support the stucco entablature ; second story, fancy pilasters and corner blocks. The attic and kitchens, plain pilasters and corner blocks ; all doors to have hard-wood thresholds. STAIRS, To be built as per plan, in the hall one flight, circular-framed carriages, curtail step and scroll, mahogany rail and balusters, noosing-step returned, framed gallery, skirtings, &c. ; a turned iron newel to support the rail ; / represents the common staircase, leading from the basement floor to the attic, framed carriage and newels, the newels turned ; newels and rails of cherry-wood, round pine balusters, noosingsteps returned, the steps and risers grooved to receive the plinths, proper ease off, &c. ; the stairs lighted from a sky-light through the roof; casings for rooms, where pilasters are introduced for doors and windows, should show" only the plinth between , you may have the attic base for the pilasters and sub-plinth ; for details, pilasters and capitals, see plate 3, fig. 1 or 2. SHEATHING. The kitchen and store-room, in the basement story, sheathed up with boards from five to six inches wide, four feet from the floor ; sheath also the bathing-room, plate 10, fig. 2, at f ; also provide and put up water-closet in the same, with such conveniences as are used in the first-class houses ; have bathing-tub and water-tank fitted to use warm and cold water at pleasure ; shower-bath, and proper apparatus for the same. LATHING AND PLASTERING. Lath and plaster all the walls ; ceiling and partitions to be lathed and plastered with good lime and hair mortar, two coats, and finished with one coat of fine stuff. Whiten the ceiling, and prepare the walls for painting. The floors to be deepened by plastering on the under floors. Set cooking-range with cast-iron back, cast hollow for heating water. See article on warming. WARMING. This house is intended to be warmed by heated water. Perkins' patent is upon a principle that will bear investigation. The cooking-range in the kitchen is made with a hollow cast-iron back, to hold from four to five gallons, with copper pipes introduced, one at the bottom and one at the top of this back, extending near three feet from the boiler, one and a half to two inches, calibre , then lead pipe of the same size to be carried to the rooms to be warmed ; there lay a coil of about forty feet of pipe ; the coil may be enclosed in a chamber to imitate a piece of furniture, thence carried to all the apartments in the house, and returned to the under pipe connected \x\{\\ the hollow back, having the whole tightly closed by soldering ; then introduce an aperture at the highest point, made convenient for filling with water. When filled, close the aperture, when, by the common use of the range, a current is produced in the water within the pipe, passing from the upper pipe heated, and returning one filling will last considerable time without renewing the water. Another, and, as we think, a still better method of warming houses, or other buildings, by means of heated water, is that of Mr. Dexter, of this city. The following is a description of this method, as exemplified in the house of Mr. S. K. Williams, No. G8 Boylston-street. A chamber of brick-work is built in the cellar, under the front entry, containing 360 cubic feet ; under, and near the centre, is a grate similar to those used for Bryant and Herman's furnaces, over which is set a copper boiler, holding thirty-two gallons ; on one side of the boiler are fifty-four copper tubes, four inches in diameter and four feet long, set perpendicular, and resting upon a table of brick-work, three and a half feet above the bottom of the cellar ; connected by six semi-cylindrical pipes, five feet in length, entering from the boiler, parallel to each other, and uniting with the boiler at the bottom. The upper ends of the tubes are united with each other in a transverse direction. The boiler is a cylinder, set upright above the brickwork four feet in height, and extends nearly to the height of the tubes. In the entry above is set a copper vessel with a lid to shut tight, containing sixteen gallons ; a tube three-fourths of an inch in diameter enters near the bottom, passing down through the air-chamber into the boiler, for the purpose of filling by a force-pump ; a stop-cock is inserted in the vessel at top, to supply the boiler with cold water. The heated water is drawn from the same boiler for warm baths, and from this airchamber are funnels, registers and dampers, entering parlors, entry, &c. To com municate direct heat to the chambers, there is a wooden box ten by fourteen inche-s square, set perpendicular against the wall of the entry, passing up to the entry above, or communicating with the rooms by horizontal pipes and registers through the floor. At one side of the grate is a projection of brick-work, enclosing a metallic cylinder, fourteen or fifteen inches in diameter and about four and a half feet perpendicular, the top of which communicates with a register by a horizontal pipe. Near the bottom of this cylinder is a horizontal branch to admit the heated air from the large chamber to the small one. The smoke-pipe passes from the grate into the large chamber, entering the perpendicular cylinder through the lower branch, thence through one side of the cylinder, horizontally, to the chimney-flae ; thus leaving sufficient space to admit the heat from the long chamber into the cylinder, around the smoke-pipe. To admit cold air into the chamber, a flue is provided twelve inches square, entering in a downward direction under the front door-steps. This flue passes horizontally under the cellar floor, rises in a perpendicular direction, and enters the chamber near the top. The cold air finds its way through the hot air in the chamber, and becomes sooner rarefied than when entering near the bottom of the chamber. This experiment, by Mr. Dexter, is highly successful. It is secure against any eruption from the boiler or pipes, to the injury of the house or of its occupants. The rarefied air thus obtained produces a sensation similar to that produced by sitting in a room, with the windows up, in the month of June. In effect, winter is thus changed into summer. Fig. 1 is a geometrical elevation of a very genteel residence, with a piazza in front, the entrance on the right-hand side ; this house may be built of wood, framed walls, floors and roof, the roof slated or shingled as may best suit the proprietor ; the walls boarded and sheathed. Fig. 2. The principal floor : a, the entrance -hall, ten feet wide ; b, b, parlors with sliding- doors ; c, principal stair-case ; d, china-room ; g, kitchen.; i, pantry ; /, Avood-house ; h, back stairs ; e, the piazza. Scale, fifteen feet to an inch. Fig. 1. A perspective view of plate 11, fig. 1. Fig. 2. The second floor: a, b, d, e, f, bed-chambers; dressing or bathing room ; g, the back staircase ; a, the front stair-landing ; c, c, closets. The estimate for building this house, all above the cellar, is two thousand dollars ; done in a plain manner, according to the design here given. Fig. 1. The elevation of a cottage, very convenient for a small, genteel family ; drawn for French windows in the piazza ; to be built of wood, fourteen feet length of posts, ten feet first story, three feet eight inches upright walls in the attic ; attic story, eight fe«t in clear height. From the temple on the Ilyssus, at Athens. In this example I have omitted the human figures in the entablature, the adoption of which, by many, is considered superfluous and absurd ; and have selected only those ornaments which essentially belong to the order, strictly preserving the proportions. for the diameter. Fig. 2 is the attic base, -which is used in common to the orders. The column of figures under the letter H shows the height of the members, and under P, the pro jections from a line drawn perpendicularly through the centre, the entire height of the order. Fig. 2. The elevation of the capital. Fig. 3. One of the scrolls, on which is shown the method of drawing the same. Make the whole height forty minutes of the order ; then drop a plumb-line indefinitely from the lesser projection of the echinus. Take nineteen and a half minutes from A to B. From B draw indefinitely the line B, c, at right angles with A, B. From B set off on B, c, three minutes to D. From D drop indefinitely the perpendicular D, E. On D, E, set off three minutes to F. From F draw indefinitely the horizontal line, F, G. On F, G, set off three minutes, to 7, making the square B, D, F, 7. By diagonal lines find the centre of this square which will be the centre of the eye. To-dcscribe the curves of the volute, extend your dividers from B to A, and describe the quadrant, A, c. On the point D, describe c, E. On the point F, describe E, G. On the point 7, describe G, I. This completes the first revolution. For the second revolution : divide each side of the square B, D, F, 7, into six equal parts, or half-minutes. On each side of this square set off one half-minute, and draw indefinitely the line 1, 3, 2, parallel to B, D, c; 3, 4, 5, parallel to D, F, E; 5, 0, 6, parallel to F, 7, G; and o, 1, 8, parallel to 7, B, A. Now, on point 1, describe the quadrant 7, 2. .On point 3, describe the quadrant 2, 4. On point 5, describe . 4, 6. On point o, describe 6, 8. This completes the second revolution. For the Fig. 1. The example from the temple of Minerva Polias, leaving the ornamented mouldings for those who prefer to make use of them in more expensive structures. The proportional measures are given on the margin in height and projections. Fig. 2. The Ionic base. Fig. 3. Elevation Of the order. See figures on the margin. This style of base, the attic, or the base on pilasters, plate 18, fig. 1, may be used as may be most appropriate for the structure into which they are introduced. The Ionic base may be most proper for common use. Fig. 5. Part of the elevation of cap to column, plate 17, fig. 1. Fig. 6. Method of drawing raking mouldings to coincide in B, A, c. AbA, draw a right angle to Be; divide the depth of the moulding into four equal parts, as 1, 2, 3, 4 ; draw parallel lines through 1, 2, 3, 4, to d,f, h. At the square, raise a perpendicular to o. From b, d, /, h, points of intersection, draw lines intersecting this, at right angles, at a, c, e, g. Now transfer b, a, to 4, 4 ; d, c, to 3, 3 ; /, e, to 2, 2 ; h, g, to 1, 1. Transfer the same to c, as a> b; c, d; e,f; g, h. Draw curved lines through each point of intersection, making the form of the moulding, which will MOULDINGS. The original Grecian mouldings are best adapted for classical works, and produce, in my opinion, the best effect ; invariably preserving the elliptic or conic sectional form, while the Roman are composed of parts of regular circles ; and the modern taste seems to have varied from both, inasmuch as straight lines have taken the place of circles and ellipses, as shown in plate 20, b, c; while a, d, e, f, g, preserve Grecian forms. Figs, a, b, c, retain the principal curve of a Grecian cavetto, with additions or combinations of other moulded forms ; this, in some cases, may be executed, and considered as an improvement. Mouldings, as here shown, may be executed in common to each of the Grecian orders, although their combination differs somewhat in each of the Grecian examples ; d is for a Grecian Doric impost or pilaster ; e is intended for the Ionic or Corinthian, where foliage is not introduced. Figs, a, b, c, the Grecian quirk, ovolo and variations ; d, e,f, cyma-reversa, and variations for the sake of variety ; g, cyma-recta ; h, bed-mould ; i, cyma-recta and addition of quirk and quarter round, which, in some cases, may be used with good effect, at near a level with the eye. Fig. 1. The elevation of a cottage, very convenient for a small genteel family ; drawn for French windows in front. To be built of wood, fourteen feet length of posts, ten feet first story, three feet upright walls in the attic. Attic story, eight feet in clear height. This villa is designed for a genteel dwelling in a village or country town, to be erected on the summit of a gentle eminence. It is intended for comfort and convenience rarely met with in any dwelling ; as dwelling-houses depend much on their location for comfort, health, and pleasure. Fig. 2. The first floor : a, entrance hall ; b and c, parlors ; d, dining-room ; e, sitting-room ; /, back entry and stairs ; A, kitchen ; i, closet ; j, bathing-room ; g, back passage ; k, wood-house. Scale, fifteen feet to an inch. Fig. 1. Geometrical elevation, Avith French windows and frontispiece. This house is intended for a professional gentleman, a, vestibule ; b, dining-room ; c, parlor ; d, e, ante-rooms ; /, china-closet ; g, kitchen ; h, back entrance to staircase. The elevation of an Ionic house, having the Ionic proportions, but the Doric dressings ; Egyptian style of windows. The windows and doors, sash and glass ; each fold of sash to swing in, containing two widths of glass of fourteen inches each, four lengths in height, of one foot nine inches each ; the window in the frontispiece will serve well for a door, and as a window to light the vestibule. The roof to be covered with galvanized tin, with copper eave-gutters, &c. Fig. 1. Elevation of a dwelling-house, two stories : a low basement and cellar ; for the basement it should be walled up, an open area with stone steps to descend from the bank, to give a pass to this story outside the exterior walls. Fine hammered granite facings, backed up' with brick ; the partitions, walls, and chimneys, laid of brick, and a metallic covering for the roof. Fig. 1. A different front for plate 29, fig. 2. Although the style of this front, in its peculiar characteristic, is omitted, it still preserves the Ionic proportion, and is well adapted for a house planned as plate 29, fig. 2. Fig. 2. A third front elevation for the same. This elevation essentially differs from the other two, and approaches nearer the ancient English style. Its effect is rather picturesque than otherwise. The second floor may be arranged very similar to the principal one. The two designs on this plate tire intended for an attic story. This order seems to have taken rise in the flourishing days of Corinth, a celebrated city of Greece. The proportions of the order resemble the graceful figure of a virgin, more delicate than the more mature age of the matron, which has given rise to the Ionic proportions. The composition of foliage is considered the leading character of the Corinthian capital, which is arranged in two annular rows of leaves, so that each leaf in the upper row grows up between those of the lower row, in such a manner that a leaf of the upper row will stand in the middle of each face of the capital, and from each leaf of the upper row three stocks spring with volutes, two of them meeting under the angle of the abacus, and two in the centre of the side, touching or interwoven with each other. A capital thus constructed is called Corinthian. This example is from the lantern of Demosthenes, otherwise called the monument of Lysicrates. With some variation in the entablature and dentils, it may be considered a beautiful specimen of the Grecian art, and may be imitated with success when elegance is required in the composition. Fig. 1 represents the entablature and cap of the column. Fig. 2. The base : dimensions of height and projections figured under P, H, from a scale of sixty minutes /or the diameter of the column at the base. Fig. 3. The full-length column, entire height of the order. pilaster, is equal to the diameter of the column at the neck, and equal in width at top and bottom ; thus avoiding the difficulty of increasing the projection of the capital beyond that of the column to which it may be attached. This example is taken from the Pantheon, at Rome ; although considered somewhat plainer than that from the temple of Jupiter, it is, notwithstanding, beautiful and chaste ; it is considered an excellent example of the Roman style. Figs. 1, 2, 3 and 4, are designs for stucco cornices. Fig. 5. Scale of inches which will answer for height. Fig. 1, for twenty feet ; fig. 2, for sixteen feet ; fig. 3, for twelve feet ; and fig. 4, for eleven feet. Fig. 6. Single architrave for the Doric order. Fig. 7. Single architrave for the Ionic order. Fig. 8. Single architrave for the Corinthian order. Fig. 9. Section of the finish of doors. See plate 6. Fig. 1 exhibits a perspective view of a Corinthian house. Although the modillions and other enrichments are omitted, the Corinthian proportions are preserved, which may be added where expense is not limited. Fig. 2. Geometrical elevation of the principal front. This design, carried out in full Corinthian order, will produce a very beautiful effect. It contains most of the conveniences required in a gentleman's dwelling of the first class. This plate exhibits the first floor. The dimensions are figured on the several apartments ; — the closets in each corner. In the back rooms, the corners will serve well for closets, dressing-rooms, &c. ; in the front ones, for water-closets, or for other conveniences, as may be required. These projections produce a very good effect in the exterior composition, and form fit recesses for the porticos. The introduction of the pier and anta, at each end of the portico, prevents the naked appearance that would be produced by the insulated column. Parlors, sixteen by eighteen feet; sitting-room, sixteen by sixteen ; dining-room, sixteen by sixteen ; front entrancehall, fifteen feet wide ; back entrance, six feet wide ; kitchen, sixteen by sixteen ; This plate represents the framing of the first floor. Sills, eight by twelve inches ; hearth-trimmers, three by twelve ; floor-plank, two by twelve inches ; kitchen hearthtrimmers, four by twelve ; one foot from centre to centre. This plate shows the framing of the second floor as per plan ; sixteen inches from centre to centre ; girders, seven by eleven inches ; hearth and stair trimmers, three by eleven ; plank, two by eleven ; the principal rooms are to have two tiers of bridging. Figs. 1, 4 and 7, represent columns, or piers. Fig. 1 is intended for exterior decoration ; figs. 4 and 7 for interior ; to support the ceiling of churches, where vaulted arches are introduced. The parts rising above the caps show the spring of the arches and their curves ; the perpendicular lines, the transverse groins, which, as they rise, and are intersected by the embossed ribs springing from the other piers or columns, are sometimes spread out. They are occasionally ornamented with rosettes, or various kinds of foliage. Figs. 2, 5 and 8, are sections of piers or columns. Fig. 2 shows the position of the four small reeds introduced in the curvilinear form of the main shaft. Fig. 5 is from the nave of York cathedral, and fig. 8, from Exeter cathedral. These examples are beautiful. The general form of figs. 5 and 8 being square, and placed diagonal to the face and spring of the arches, and clustered with reeds, makes a good support at the base line from which the arches spring. The splay of the arches with bold GOTHIC. 89 mouldings has a very beautiful effect. Figs. 3, 6 and 9, are intended ior the bases which are represented in sections ; 2, 5 and 8, the outline curves, represent the larger reeds, while the smaller ones are continued through the base to the plinth. Fig. 1 represents a window from Sleyford church, Lincolnshire, England, but reduced for a smaller window. The arch is formed on an equilateral triangle, and is sometimes filled with flowing tracery, and quatrefoils, and cinctures. See the figure." The deep curved hollow within the columns forms a very good drip-stone in the arch, and a deep shade on the sides ; which effect is good. Scale, threeeighths of an inch to a foot ; it may be used to advuutage for churches, or other public buildings of this style of architecture. Fig. 2 is a window used in the centre of the front of churches when a tower is introduced in the composition. Its effect is decidedly good. The head of this window being the ogee arch, the canopy is ornamented with crockets and a finial. Fig. 1 is the outline drawing of a large size for fig. 2. Fig. 2. The spandrell-head window, as frequently used for small windows for Gothic dwellings. This cap forms a very good drip-stone ; the top being level, the sides drop at right angles with the top and ends, but are sometimes continued on a level, to stop against the pilaster, or to form a connection with the adjoining windows. Fig. 1. Geometrical elevation of a Gothic dwelling, having two upright stories. Fig. 2. Plan of principal floor. The dimensions of rooms are figured on the plan. This house may afford conveniences over many others. The exterior, properly carried out, gives quite a picturesque appearance. Scale, fifteen feet to an inch. Estimated cost of building, four thousand and five hundred dollars. Fig. 1. Geometrical elevation of a dwelling built for David Sears, Esq., in Brookline, Mass. This house was built of brick ; the cellar of stone ; slate and galvanized tin roof-covering ; copper gutters and trunks ; cooking-range in kitchen ; bathingroom, water-closet, &c, in the second story; and a Bryant and Herman's furnace set in the cellar ; also a well and cistern. Exterior wralls painted and sanded ; freestone caps and sills. The cost of this building was eight thousand dollars. OPERATION. Fig. 1. Draw the lines 0, X, intersecting at L ; draw the cord of the semi-circle, I ; find the centre line 7 ; extend this line to the intersection at L ; divide one-half of the semi-circle into seven equal parts, on -each side, as figured ; divide K in the same manner as I. Draw lines from 1, 2, 3, 4, 5, 6, to intersect X at 1, 2, 3, 4, 5, 6. From 1, 2, 3, &c, on X, draw lines at right angles with X, indefinitely. Transfer the distance between 1,-2, 3, &c, on the semi-circle and its chord, to these last-drawn perpendicular lines at a, b, c, &c. ; and a line passing through these several points, 1, a; 2, b; 3, c, &c, will give the curve of the hip or groin. COVERING OF CENTRES. Divide the whole length of the hip, a, b, c, d, e,f, g, into seven equal parts; draw the centre line, K, L, H, from the chord in H; take six of the seven parts of the hip ; lay off on the centre line ; divide into seven equal parts. Extend the lines of intersection from a, b, c, d, e,f, g, in K, through 1, 2, 3, 4, 5, 6, on X; then through the cord H, intersecting 1, 2, 3, 4, 5, 6, 7, in H, at a, b, c> d, e,f, g; trace a curve line through these intersections. This will form the curve to cut the covering of the centres. II, I, may be performed as the above, K, H; — a, a, a, a, &c, represent sections of the piers from which the arches are formed. In this enlightened and Christian country, where the arts and sciences are daily applied to the comfort and convenience of the whole people, this branch of architecture has hitherto been very much neglected. In regard to the elegance and costliness of its structures devoted to the worship of God, our country can bear no comparison with the civilized nations of Europe. ' There are many obvious reasons why this is so. — First, the superior age, wealth and population of those countries, may be urged as reasons why we cannot hope, at present, to compete with them in erecting such magnificent edifices as adorn their principal cities. Our fathers came to these shores to escape the imposition of religious forms and doctrines which their consciences disapproved ; and this, no doubt, prejudiced their minds against the "pomp and pride" of prelacy, as well as of royalty; and left as little desire to imitate the magnificent church structures they had left behind, as to copy the political forms of their father-land. Again, the pecuniary depression under which our forefathers labored, the numberless sacrifices they made for the true dignity and honor of the religion of Christ, and their deep-seated aversion to ostentation of any kind, would alike forbid the erection of elegant structures, and account for the almost total neglect with which this department of architecture has hitherto met, in our country. It would be very difficult, perhaps, in the present state of things among us, to imitate the highly enriched and expensive structures which have, for so long a time, been the pride and glory of the older world. But we cannot but indulge the hope, that, ere long, though we may not surpass or even equal those nations, the greater part of whose wealth and power has been in the hands of the church, in th« grandeur and costliness of our religious edifices, we may yet equal them in regard to the taste and architectural simplicity of these structures ; qualities more in harmony with our republican form of government, and, as we cannot but think, with the simplicity of our faith and worship, than would be the cathedrals of York, Milan or Eome, even if we could reproduce them here. After consulting convenience and strength, the next thing to be attended to in a religious edifice is the proportion and details of the building, which must all be made to harmonize Avith the general design ; or else the grand object — the adaptation of the structure to the purposes of public worship — is wholly lost. No one, who has within him a spirit that prompts him to worship God, can be insensible to an emotion nearly allied to that of religious reverence, when he approaches and enters a Gothic structure, built with due regard to the rules of the art. The lofty spire, pinnacles and finials, seem as so many fingers pointing upward to heaven, and directing his way thither. In the massive tower and battlements, the mind perceives an emblem of the stability of truth, and of the gracious promises of God, and is led to repose confidingly in Him. On entering, the mind swells with the feeling of sublimity, and seems, almost involuntarily, to rise in adoration of the Being who is himself so great, and has given to man the power to raise a temple so fit for His worship. Though, sometimes, Ave must confess, where the grandeur and ornament of the structure have been carried to the extreme point, which they attained, especially in Catholic countries, in those ages when the greatest attention Avas given to the magnificence of ecclesiastical buildings, our mind has been irresistibly withdrawn from the object to the place of Avorship ; and Ave have been profoundly impressed with the truth of those Avords of the great apostle to the Gentiles, which he spoke while standing upon Mars Hill, in the very shadoAV of the most beautiful, imposing, and architecturally perfect, of all the temples that have ever been raised by human hand3 for divine worship, — "God, that made the world, and all things therein, seeing that he is Lord of heaven and earth, dwelleth not in temples made with hands, neither is worshipped with men's hands as though he needed anything, seeing he giveth to all life, and breath, and all things." Still, in the severest notions that can be entertained of the spirituality of the object of our worship, or of the service that it is at once our duty and blessing to offer Him, there is nothing that forbids, but, rather, much that favors, a highly-cultivated taste, and the purest style of structure and ornament, in temples dedicated to the worship of God, — that Being who has given man a faculty to perceive and enjoy beauty and sublimity, in all their forms, and then surrounded him with such an endless variety of objects, the work of his own creative hand, by which that faculty may be exercised, cultivated and gratified. Having spoken thus of the importance and effect of proportion, and of the general harmony of the parts with the design or object of the building, we would only observe, in addition, that this effect is greatly aided by an appropriate material for the structure, as also by the colors that are introduced into its various parts, and the degree of light or shade thrown over the interior. Quincy granite is a material which, for the exterior of a church, is admirably adapted to its main purpose. Its great solidity, and consequent durability, and the gravity of its color, especially when unhewn, render it exceedingly fit, especially for a massive religious structure. And, for the interior finish, the native black walnut of our country harmonizes equally with its main object. The walls will require paint of a lighter tint, and the ceiling should be of a light stone-color. Fig. 1. The front elevation of a Gothic church, for a village or country town ; showing the steeple, pointed buttresses, arches and finials, with their proper ornaments ; a basement for school-room, &c. Fig. 2. The elevation of a Gothic church, with a low basement. The height of the principal story, twenty-five feet. This front has a tower and parapet ; the tower with battlements and appropriate ornaments. The building, fifty-two feet by eighty, exclusive of the tower, which projects ten feet. Height of tower, seventy-five feet. Scale, twenty feet to an inch. Fig. 1. Side elevation of fig. 2, plate 51. Here is shown the spandrell windowcaps, or drips, the turrets, the Tudor flower at the eaves, the trefoils and quatrefoils. The windows to have diamond sash ; the belfry with a large quatrefoil window. Fig. 2. The principal floor of elevation of fig. 2, plate 51, and of fig. 1, plate 52. This floor contains eighty-four pews, in which five hundred persons can be seated with comfort : a, the entry ; b, b, staircases ; d, d, side aisles ; c, the broad aisle ; g, the pulpit. Figs. 3 and 4, the front and back ends. Fig. 3 is the entrance to the basement ; a, front doorway ; b, b, staircases ; d, d, side aisles ; c, the broad aisle. Fig. 4 shows the arrangement for the back end for the Episcopal form of worship : a, the altar ; b, the broad aisle ; g, g, side aisles ; e,f, robing-rooms ;»c, the reading, and d, the sermon desk. Plate 53 Represents the front elevation of a modern Gothic church, drawn to a scale of twenty-five feet to an inch ; the columns octagon, with buttresses attached, and surmounted with pointed pinnacles, and finials ; cornices with terret blocking ; the windows Flemish arch ; the tower above the roof thirty feet square ; height from the entrance floor to the bell-deck, eighty-seven feet. Steeple at the base, twenty feet octagonal ; height one hundred and twelve feet from the deck ; eight octagon This represents the side elevation of plate 53 ; scale twenty-five feet to an inch ; six Gothic columns ; also the tower two, and five windows in the body, and two in the tower the opposite side, to correspond with this as to the arrangement of columns, windows, and their respective details. Fig. 1 represents the ground plan, sixty-two by eighty-four feet ; tower projects in front nineteen feet ; in the rear is a vestry, twelve by twenty-five feet. N. B. — The thickness of Avails, and projection of columns and buttresses, to be added. The principal entrance and staircase, ten by sixty-two feet. The arrangement of pews and aisles is considered very convenient, and will accommodate one thousand seats on the first floor, and gallery three hundred. Fig. 2 shows the gallery, the arrangement of pews and orchestra, the landing of the stairs on the second or gallery floor, and a section of two columns, on which the rear part of the tower is to be supported. respective angles. Fig. 4. Transverse section near the centre of ihQ building, the inclination of the galleries, also the arrangement of the timbers in the roof, and the two columns to support the tower, also the form of the groined arches. This is one of the most important subjects connected with the art of building, and should be attentively considered, not only with regard to the situation, but as to the design and execution. The convenience of the building depends on the situation ; and the elegance, on the design and execution of the workmanship. In contriving a grand edifice, particular attention must be paid to the situation of the space occupied by the stairs, so as to give them the most easy command of the rooms. " Staircases," says Palladio, "will be commendable, if they are clear, ample and commodious to ascend ; inviting, as it were, people to go up ; they will be clear, if they have a bright and equally diffuse light ; they will be sufficiently ample, if they do not seem scanty and narrow to the sia and quality of the fabric ; but they should never be less than four feet in width, that two persons may pass each other ; they will be convenient with respect to the whole building, if the arches under them can be used for domestic purposes ; and with respect to persons, if their ascent is not too steep and difficult, to avoid which, the steps should be twice as broad. as high." STAIR BUILDING. 99 light, with elegance in the design ;- indeed, where the staircase does not adjoin the exterior wall, this is the only light that can be admitted. "Where the height of a story is considerable, resting-places are necessary, which go under the name of quarter-paces and half-paces, according as the passenger has to pass one or two right angles ; that is, as he has to describe a quadrant or semi-circle. In very high stories, which admit of sufficient head-room, and where the space allowed for the staircase is confined, the staircase may have two revolutions in the height of one story, which will lessen the height of the steps ; but in grand staircases only one revolution can be admitted, the length and breadth of the space on the plan being always proportioned to the height of the building, so as to admit of fixed proportions. The breadth of the steps should never be more than fifteen inolies, or less -than nine ; the height, not more than seven or less than five ; there are cases, however, which' are exceptions to all rule. When the height of the story is given in feet, and the height of the step in inches, you may throw the feet into inches, and divide it by the number of inches the step is high, and the quotient will give the number of steps. It is a general maxim, that a step of greater breadth requires less height than one of less breadth : thus a step of twelve inches in breadth will require a rise of five and a half inches, which may be taken as a standard, to regulate those of other dimensions. Though it is desirable to have some criterion as a guide in the arrangement of a design, yet workmen will, of course, vary them as circumstances may require. Stairs are constructed variously, according to the situation and destination of the building. Geometrical stairs are those which are supported by having one end fixed in the wall, and every step in the ascent having an auxiliary support from that immediately below it, and the lowest step from the floor. architrave. Dog-legged stairs are those which have no opening, or well-hole, and have the rail and baluster of both the progressive and returning flights falling in the same vertical planes, the steps being fixed to strings, newels and carriages, and the ends of the steps of the inferior kind terminating only upon the side of the string, without any nosing. In taking dimensions and laying down the plan and section of staircases, take a rod, and, having ascertained the number of-steps, mark the height of the story by standing the rod on the lower floor ; divide the rod into as many equal parts as there are to be risers, then, if you have a level surface to work upon below the stair, try each of the risers as you go on, and this will prevent any excess or defect ; for any error, however small, when multiplied, becomes of considerable magnitude, and even the difference of an inch Lu the last riser will not only have a bad effect to the eye, but will be apt to confuse persons not thinking of any such irregularity. In order to try the steps properly hy the story-rod, if you have not a level surface to work from, the better way will be to lay two rods on boards, and level their top surface to that of the floor ; place one of these rods a little within the string, and the other near or close to the wall, so as to be at right angles to the starting line of the "first riser, or, which is the same thing, parallel to the plan of the string ; set off the breadth of the steps upon these rods, and number the risers ; you may set not only the breadth of the flyers, but that of the winders also. In order to try the story-rod exactly to its vertical situation, mark the same distances of the risers upon the top edges, as the distances of the plan of the string-board and the rods are from each other. ship is as much regarded as in geometrical stairs, the baluster must be neatly dovetailed into the ends of the steps, two in every step. The face of each front baluster must be in a straight surface with the face of the riser, and, as all the balusters must be equally divided, the face of the middle baluster must stand in the middle of the face of the riser of the preceding step and succeeding one. The risers and heads are all previously blocked and glued together, and, when put up, the under side of the step nailed or screwed into the under edge of the riser, and then rough brackets to the rough strings, as in dog-legged stairs, the pitching pieces and rough strings being similar. For gluing up the steps, the best method is to make a templet, so as to fit the external angle of the steps with the nosing. The steps of geometrical stairs should be constructed. so as to have a very light and clean appearance when put up : for this purpose, and to aid the principle of strength, the risers and treads, Avhen planed up, should not be less than one-eighth of an inch, supposing the going of the stair, or length of the step, to be four feet, and for every six inches in length another one-eighth may be added. The risers ought to be dovo-tailed into the cover, and when the steps are put up the treads are screwed up from below to the under edge of the risers. The holes for sinking the heads of the screws ought to be bored with a centre bit, then fitted closely in with wood, well-matched, so as entirely to conceal the screws, and appear as one uniform surface. Brackets are mitred to the riser ; and the nosings are continued round. In this mode, however, there is an apparent defect ; for the brackets, instead of giving support, are themselves unsupported, and dependent on the steps, being of no other user, in point of strength, than merely tying the risers and treads of the internal angles of the step together ; and from the internal angles being hollow, or a re-entrant angle, except at the ends, which terminate by the wall at one extremity, and by the brackets at the other, there is a want of regular finish. The cavetts, or hollow, is carried round the front of the riser, and is returned at the end, and mitred view, the hollow is continued along the angle of the step and the risers. The best plan, however, of constructing geometrical stairs is, to put up the strings, and to mitre the brackets to the risers, as usual, and enclose the soffits with lath and plaster, which will form an inclined plane under each flight, and a winding surface under the winders. In superior staircases, for the best buildings, the soffits may be divided into panels. If the risers are made from two-inch plank, it will add greatly to the solidity. In constructing a flight of geometrical stairs, where the soffit is enclosed as above, the bearers should all be framed together, so that when put up they will form a perfect staircase. Each piece of farm-work, which forms a riser, should, in the partition, be well wedged at the ends. This plan is always advisable when strength and firmness are requisite, as the steps and risers are entirely dependent on the framed carriages, which, if carefully put together, will never yield to the greatest weight. In preparing the string for the wreath part, a cylinder should be made of the size of the well-hole of the staircase, which can be done at a trifling expense ; then set the last tread and riser of the flyers on one side, and the first tread and riser of the returning flight on the opposite side, at their respective heights ; then on the centre of the curved surface of this cylinder mark the middle between the two, and with a thin slip of wood, bent round with the ruling edge, cutting the two nosings of these flyers, and, through the intermediate height marked on the cylinder, draw a line, which will give the wreath line formed by the nosings of the winders ; then draw the whole of the winders on this line, by dividing it into as many parts as you waut risers, and each point of division is the nosing of such winder. Having thus far proceeded and carefully examined your heights and widths, so that no error may have occurred, prepare a veneer of the width intended for your string, and the length given by the cylinder, and after laying it in its place on the cylinder, proceed to glue a number of blocks about an inch wide on the back of the veneer, with their fibres parallel to the axis of the cylinder. framed into the straight strings. It is necessary to observe, that about five or six inches of the straight string should be in the same piece as the circular, so that the joints fall about the middle of the first and last flyers. This precaution always avoids a cripple, to which the work would otherwise be subject. This art consists in constructing hand-rails by moulds, according to the geometrical principles, that if a cylinder be cut in any direction, except parallel to the axis or base, the section will be an ellipsis ; if cut parallel to the axis, a rectangle ; and if parallel to the base, a circle. . Now, suppose a hollow cylinder be made to the size of the well-hole of the staircase, the interior concave, and the exterior convex, and the cylinder be cut by any inclined or oblique plane, the section formed will be bounded by two concentric similar ellipses ; consequently, the section will be at its greatest breadth at each extremity of the larger axis, and its least breadth at each extremity of the smaller axis. Therefore, in any quarter of the ellipsis there will be a continued increase of breadth from the extremity of the lesser axis to that of the greater. Now, it is evident that a cylinder can be cut by a plane through any three points ; therefore, supposing we have the height of the rail at any three points in the cylinder, and that we cut the cylinder through these points, the section will be a figure equal and similar to the face-mould of the rail ; and if the cylinder be cut by another plane parallel to the section, at such a distance from it as to contain the thickness of the rail, this portion of the cylinder will represent a part of the rail with its vertical surfaces already worked ; and again, if the back and lower surface of this cylindric portion be squared to vertical lines, either on the convex or concave side, through two certain parallel lines drawn by a thin piece of wood, which is bent on that side, the portion of the cylinder thus formed will represent the part of the rail intended to be made. to rails erected on any seat whatever. The face-mould applies to the two faces of the plank, and is regulated by a line drawn on its edge, which line is vertical when the plank is elevated to its intended position. This is called the raking-mould. The falling-mould is a parallel piece of thin wood applied and bent to the side of the rail piece, for the purpose of drawing the back and lower surface, which should be so formed that every level straight line, directed to the axis of the well-hole, from every point of the side of the rail formed by the edges of the falling mould, coincide with the surface. In order to cut the portion of rail required out of the least possible thickness of stuff, the plank is so turned up on one of its angles, that the upper surface is nowhere at right angles to a vertical plane passing through the chord of the plane ; the plank in this position is said to be sprung. The pitch-board is a right-angled triangular board made to the rise and tread of the step, one side forming the right angle of the width of the tread, ' nd the other of the height of the riser. When there are both winders and flyers, two pitch-boards must be made to their respective treads, but, of course, of the same height, as all the steps rise the same. In the construction of hand-rails, it is necessary to spring the plank, and then to cut away the superfluous wood, as directed by the draughts, formed by the facemould ; which may be done, by an experienced workman, so exactly, with a saw, as to require no further reduction ; and when se't in its place, the surface on both sides will be vertical in all parts, and in a surface perpendicular to the plan. In order' to form the back and lower surface, the falling mould is applied to one side, generally the convex, in such a manner that the upper edge of the falling mould at one end coincides with the face of the plank ; and the same in the middle, and leaves so much wood to be taken away at the other end as will not reduce the plank on the concave side ; the piece of wood to be thus formed into the wreath or twist, being agi'eeable to their given heights. To grade the front string of stairs, having winders in a quarter-circle at the lop of the flight, connected with flyers at the bottom. — In Fig. 1, Plate 57, a, b represents the line of the facia along the floor of the upper story, b, e, c the face of the cylinder, and c, d the faoe of the front string. Make g, b equal to one-third of the diameter of the baluster, and draw the centre-line of the rail, /, g, g, h, i, and i, j, parallel to a, bi b, e, c, and c, d; make g, k and g, I each equal to half the width of the rail, and through k and I draw lines for the convex and the concave sides of the rails, parallel to the centre-line ; tangical to the convex side of the rail, and parallel to k, m, draw n, r, o; obtain the stretch-out, q, r, of the semi-circle, k, p, mi extend a, b to t, and k, m to s; make c, s equal to the length of the steps, and i, u equal to eighteen inches, and describe the arcs s, t and u, 6, parallel to m, p; from /, draw t, %u, tending to the centre of the cylinder ; from 6, and on the line 6, u, x, run off the regular tread, as at 5, 4, 3, 2, 1, and v; make u, x equal to half the arc u, 6, and make the point of division nearest to x, as v, the limit of the parallel steps or flyers ; make r, o equal to ?n, z; from o, draw o, a3, at right angles to n, o, and equal to one rise ; from a3, draw a2, s, parallel to n, o, and equal to one tread ; from s, through o, draw s, b2. Then, from w, draw iv, c2 at right angles to n, o, and set up on the line w, c~ the same number of risers that the floor, A, is above the first winder, B, as at 1, 2, 3, 4, 5 and 6 ; through 5, on the arc 6, u, draw d2, e2, tending to the centre of the cylinder ; from e2, draw e2,/2 at right angles to n, o, and through 5, on the line w, c2, draw g2,/2 parallel to n, o; through 6 (on the line, w, c2) and f2, draw the line A2, b2; make 6, c2 equal to half a rise, and from c2 and 6 draw c2, i2, and 6,/2, parallel to n, o; make h2, i2 equal to h2,f2; from i2, draw i2, k2, at right angles to i2, h2, and from f2 draw f2, k2, at right angles to f2, h2; upon k2, with k2,/2 for radius, describe the arc f2, i2; make b2, P equal to b2,/2, and ease off the angle at b2, by the curve f2, b2. Then from 1, 2, 3 and 4 (on the line w, c2), draw lines parallel to n, o, meeting the curve in m2, n2, o2 and p2; from these points draw lines at right angles to n, o, and meeting it in x2, r2, s2 and t2; from x2 and r2 draw lines tending to u2, and meeting the convex side of the rail in y2 and z2; make m, v2 equal to r, s2, and tn, w1 equal to r, P; from y2, z2, v2 and w2, through 4, 3, 2 and 1, draw lines meeting the line of the wall-string in az, b?3, c3 and d3; from e3, where the centre-line of the rail crosses the line of the floor, draw e3, f3 at right angles to n, o, and from f3, through 6, draw/3, g-2; then the heavy lines /3, g2, e2, d2, y2, a2, z2, b3 v2, c3, iv2, d3 and z, y, will be the lines for the risers, which, being extended to the line of the front string, b, e, c, d, will give the dimensions of the winders, and the grading of the front string, as was required. To obtain the falling-mould for the twist of the last-mentioned stairs. — Make r, g3 and i2, h3 (fig. 1, plate 57) each equal to half the thickness of the rail ; through h3 and g3, draw h3, i3 and g3,j3, parallel to i2, z; assuming k, k3 and m, m3, on the plan, as the amount of straight to be got out with the twists, make n, q equal to k, k3, and r, I3 equal to m, m3; from n and I3, draw lines at right angles to n, o, meeting the top of the falling-mould in n3 and o3 ; from o3, draw a line crossing the falling-mould at right angles to a chord of the curve f2, b2; through the centre of the cylinder draw u2, 8 at right angles to n, o; through 8 draw 7, 9, tending to k2; then n3, 7 will be the falling-mould for the upper twist, and 7, o3 the falling-mould for the lower twist. To obtain the face-mould of one-quarter of the cylinder, as in plate 57, b, c, extend the lines 1, 2, 3, &c, to the outer curve of the cylinder, transfer those ordinates to x, z, the pitch-line ; the develop of one-quarter of the circle at right angles to x, z gives the face-mould for this section. Fig. 2. Nos. 1, 2 and 3, show the method of obtaining the face-mould, and the requisite thickness of material. No. 1, the ground plan, .with ordinates, 1, 2, 3, &c. Transfer the ordinates to the pitch-line k,f, at right angles k,f, 1, 2, 3, &c, which gives the face-mould, and No. 3 shows the requisite thickness of plank. See k, z and o, x. No. 3. To find the face-mould for Fig. 2, Plate 58. — Draw the base-line c, d ; divide c, d into any convenient number of parts, as 1, 2, 3, 4, 5, 6, at right angles to c, d, and note their intersections with the concave and convex sides of the cylinder or ground plan ; then extend these ordinates to any convenient distance at right angles to c, d, and parallel to each other ; then ascertain the angle of the pitch-line x, z, then set olf on a right angle to the pitch-line the transfers from the base c, d, which gives the curve of the face-mould required by tracing through the points noticed at the base. For the overease, see Plate 57, Fig. 2. To find the falling-mould for the rail of winding stairs. — In Fig. 1, Plate 58, a, c, b represents the plan of a rail around half the cylinder, A the cap of the newel, and 1, 2, 3, &c, the face of the risers in the ordpr they nscond. Find the stretch-out e,/, of a, c, b; from e, through the point of the mitre at the newel-cap, draw o, s; obtain on the tangent, e, d, the position of the points s and A, as at t and m ; from e, t, m and /, draw e, x, t, u, m, q and /, h, all at right angles to e, d; make e, g equal to one rise, and m, q equal to twelve, as this line is drawn from the twelfth riser ; from g, through q, draw g, i; make g, x equal to about three-fourths of arise ; draw x, u at right angles to e, x, and ease off the angle at u; at a distance equal to the thic'kness of the rail, draw v, 10, y parallel to x, u, i; from the centre of the plan o, draw o, I at right angles to e, d; bisect h, n, m, p, and through p, at right angles to g, i, draw a line for the joint ; in the same manner, draw the joint at k; then x, i, y, iv, will be the falling-mould for that part of the rail which extends from s to b, on the plan. To describe the scroll for a hand-rail over a curtail step. — Plate 58. Let c, b, fig. 3, be the given breadth, one and three-fourths the given number of revolutions, and let the relative size of the regulating square to the eye be one-third of the diameter of the eye. Then, by the rule, one and three -fourths, multiplied by four, gives seven ; and three, the number of times a side of the square is contained in the eye, beingadded, the sum is ten. Divide a, b, therefore, into ten equal parts, and set one from b to c; bisect a, c, in e; then a, e will be the length of the longest ordinate (1 dor 1 c). From a drawee, d, from c draw^1, and from b draw b, f, all at right angles to a, b; make e1 equal to c, a, and through 1 draw 1 d, parallel to a, b; set b, c from 1 to 2, and upon 12 complete the regulating square ; divide this square as at fig. 3 ; then describe the arcs that compose the scroll, as follows : upon 1, describe d, e ; upon 2, describe e,f; upon 3, describe f, g-; npon 4, describe g, h, fyc; make d, I equal to the width of the rail, and upon 1, describe I, m; upon 2, describe m, n, $-c. ; describe the eye upon 8, and the scroll is completed. the twist and the other part of the scroll. Make d, e2 equal to the stretch-out of d, e, and upon d, c2 find the position of the point k, as at k2: at Fig. 4, make e, d equal to r, d in Fig. 3, and d, c equal to d, k, in that figure ; from c, draw c, a at right angles to e, c, and equal to one rise ; make c, b equal to one tread ; and from b, through a, draw b, j, bisect a, c in /, and tlirough I draw to, q, parallel to e, h : m, q is the height of the level part of a scroll, which should always be about three and one-half feet from the floor ; ease off the angle to, f,j, and draw g, w, n, parallel to m, x,j, and at a distance equal to the thickness of the rail ; at a convenient place for the joint, as i, draw i, n at right angles to b,j; through n, draw j, h at right angles to c, h; make d, k equal to d, k2, in Fig. 3, and from k draw k, o at right angles to e, h; at Fig. 3, make d, h2 equal to d, h in Fig. 4, and draw A2, b2 at right angles to d, h2; then k, a2 and h2, i2 will be the position of the joints on the plan, and at Fig. 4, o,p and i, n, their position on the falling-mould ; andp, o, i, n (fig. 4) will be the falling-mould required. To describe the face-mould. — Plate 58. At Fig. 3, from k, draw k>, r2 at right angles to r2, d; at Fig. 4, make h, r equal to A2, r2, in Fig. 3, and from r draw r s at right angles to r, h ; from the intersection of r, s with the level line m, q, through i, draw s, t; at Fig. 3, make h2, b2 equal to q, t in Fig. 4, and join b2 and r2; from a2, and from as many other points In the arcs a2, 1 and k, d, as is thought necessary, draw ordinates to r2, d at right angles to the latter ; make r, b (Fig. 6) equal in its length and in its divisions to the line r2, b2 in Fig. 3 ; from r, n, o, p, q and I draw the lines r A, nd,o a,pe,qf and I c, at right angles to r b, and equal to r2, k, d2, s2,/2, a2, &c, in Fig. 3 ; through the points thus found, trace the curves kl and a c, and complete the face-mOuld, as shown in the figure. This mould is to be applied to a squareedged plank, with the edge I, b parallel to the edge of the plank. The rake lines upon the edge of the plank are to be made to correspond to the angle s, t, h, in Fig. 4. The thickness of the stuff required for this mould is shown at Fig. 4, between the lines s, t and u, v — v being drawn parallel to s, t. To describe the scroll for a curtail step. — Plate 58, Fig. 3. Bisect d, I, Fig. 3, in o, and make o, v equal to one-third of the diameter of a baluster ; make % w equal to the projection of the noosing, and e, x equal to w, I; upon 1 describe w, y, and upon 2 describe if; also upon 2 describe x, i, upon 3 describe i, j, and so around to 2; and the scroll for the step will be completed. * General rule for finding the size and position of the regulating square, -r- Plate 58, Fig. 5. The breadth which the scroll is to occupy, the number of its revolutions, and the relative size of the regulating square to the eye of the scroll being given, multiply the number of revolutions by four, and to the product add the number of times a side of the square is contained in the diameter of the eye, and the sum will be the number of equal parts into which the breadth is to be divided. Make a side of the regulating square equal to one of these parts. To the breadth of the scroll add one of the parts thus found, and half the sum will be the length of the longest ordinate. To find the proper centres in the regulating square. — Let a, 2,1, b, Fig. 5, be the size of a regulating square, found according to the previous rule, the required number of revolutions being one and three-fourths. Divide two adjacent sides, as a, 2 and 2, 1, into as many equal parts as there are quarters in the number of revolutions, as seven ; m from those points of division, draw lines across the square at right angles to the lines divided ; then, 1 being the first centre, 2, 3, 4, 5, 6 and 7 are the centres for the other quarters, and 8 is the centre for the eye ; the heavy lines that determine these centres being each one part less in length than its preceding line. To determine the position of the balusters under the scroll. — Bisect d, I, Fig. 3, in o, and upon I, with 1, o for radius, describe the circle o, r, u; set the baluster at p fair with the face of the second riser, k, and from p, with half the tread in the dividers, space off as at o, q, r, s, t, u, &c, as far as A; upon 2, 3, 4 and 5, describe the centreline of the rail around to the eye of the scroll ; from the points of division in the circle o, r, u, draw lines to the centre-line of the rail, tending to the centre of the will determine the position of the balusters, as shown in the figure. Note. — The figures 1, 2, 3, &c, on the left of Fig. 3, represent a method of getting the size or proportion of a scroll. Divide the face, a, c, into eleven parts ; then five and one-half of these parts will form the inside of the regulating square, 1, 2, as explained in Fig. 3. To apply the face-mould to the plank. — In Plate 57, Fig. 2, A represents the plank with its best side and edge in view, and B the same plank turned up so as to bring in view the other side and the same edge, this being square from the face. Apply the tips of the mould at the edge of the plank, as at a and o (B), and mark out the shape of the twist ; from a and o draw the lines a, b and o, c across the edge of the plank, the angles, e, a, b and e, o, c; turning the plank up as at B, applythe tips of the mould at b and c, and mark it out as shown in the figure. In sawing out the twist, the saw must be moved in the direction a, b; which direction will be perpendicular when the twist is held up in its proper position. — In sawing by the facemould, the sides of the rail are obtained ; the top and bottom, or the upper and the lower surfaces, are obtained by squaring from the sides, after having bent the fallingmould around the outer or convex side, and marked by its edges. Marking across by the ends of the falling-mould will give the position of the butt-joint. To find the falling-mould of a rail for a staircase with a semi-cylinder at each end, beginning on the gallery of the first flight and continued to the gallery of the second flight. — Draw the width of your rail on Fig. 1, Plate 59, then take a limber strip of wood and bind round the inside of your rail on Fig. 1, and mark the width of your treads on the noosing ; then lay out your falling-mould, as shown in Fig. 2. Setting up the height of your rise and using your limber strip for the width of your treads, draw a line to cut the top corner of your noosings, and make your eases from the winders down on to the flyers, and from the flyers on to lower winders, and then on to gallery, setting up on gallery one-half of your rise ; make your joints on your falling-mould, say four inches by the circle on the gallery and in the centre of the well-room, and over the sixth and sixteenth risers, as shown in Fig. 2. To obtain the position of butt-joints for the falling-mould, with a semi-cylinder at each end with winders, and a portion of the centre with flyers. — Select for the bearingpoint that position which will make the most graceful ease in the angles ; it may in some cases vary a little, in the distance from the pitch line of the risers, when the rail is to bear equal on the noosing of steps, or when fitting the joints. The joint may be so arranged as to bring the butt-joint all on the extreme curve of the ease ; consequently the straight part will require less thickness of material, but the curve part will require more thickness than if the position had been more equally divided. To find the position of the butt-joints. — Set up on the front of the rise next below the bearing point lines a, b, c equal to the depth of the rail, perpendicular to the plan, at the intersection of the rail, k, I, m; then draw the line Jc, z, tending to the centre, which gives the position of the butt-joint, as is also shown in Fig. 1, 'Plate 58. To find the face-mould for an overease. — Find c, the centre of the stretch-out, on the inside of the rail, in Fig. 1 ; draw a line from a through that point; then in Fig. 2 draw a perpendicular line to cut the joint on the top side of falling- mould, from b to c. Then draw a level line to cut the lower side of the joint of the falling-mould on the gallery, from c to d, find the centre of that line, and draw a perpendicular line to intersect the lower side of falling-mould, from e to /; then draw a level line from /to g; then draw a line from b, through / to h; take the distance from c to h, and set off on Fig. 4, from a to i; draw a line from i, to cut the inside of the joint at /; then draw a line from j at rigl^t angles with the last line from I to m; then draw a line from a to n, which is the height line. Take the height on Fig. 2, from b to c; set up that from I to n; then draw your pitch line from n to m. When the falling-mould is curved, as described in Plate 60, Fig. 1, s, r, d, b, the joints at each end of the ground plan of one-quarter of a cylinder, make a, c equal to the stretch-out of the concave side s, b, divide a, c and s, b each into the like number of equal parts on a, c, and from each point of division, a, k, c, I, at right angles to a, c, as e, f, g, h, i, intersecting the pitch line, k, j ; then draw lines, k, I, to, n, o, p, from those intersections parallel to a, c and r, d, on the corresponding pitch line w, y, z, t, andj, k, the falling-mould. From the points of division in the arc dividing the arc r, d, in the same proportion as s, b and d, r, through b, draw d, t and b, u at right angles to a, d, and from j and v draw j, u and v, w at right angles to j, c; then x, t, u, vx will be the vertical projection of the joint d, b, when the radiating lines on the plan, s, r and d, b, corresponding to the vertical lines, k, j. To represent a joint, find their vertical projection as at 1, 2, 3, 4, 5 and 6, through the corners of the parallelograms trace the curve lines shown in the figure, then 6, u will be the helinet or vertical projection of 5, r, d, b. To find the necessary thickness of plank to work out this part of the rule, draw the lines 0, t and w, y, which distance apart gives the thickness of plank required. Plate 60, Fig^. 4. Join b, c, and from 0 draw 0, h at right angles to b, c; upon the stretch-out d, g, as d,f, draw b, j and c, b at right angles to b, c; make b,j, c, I, from ltj, draw /, m, c; from h draw h, n parallel to c, b; from n drawn, r at right angles to/>, c, and join rands through the lowest corner of the plan, as p; draw v, e parallel .15 to b, c, a, e, u, p, k, t, and from as many other points as is thought necessary draw ordinates to the base line v, e, parallel to r, 5; through, h draw iv, x at right angles to 771, 1, upon n ; with r, s for radius, describe an intersecting arc at x, and join n and x from the points at which the ordinates meet the line m, I at right angles to v, e, and from points of intersection m, I draw corresponding ordinates parallel to n, x; make the ordinates which parallel to 71, x of the corresponding lengths to r, s, and through the points thus found trace the face-mould. Plate 60, Fig. 3, shows the process to obtain the helinet top and bottom joint of the butts j, k, the vertical lines ; — drawj, k to w, h, and join w and h; then w, h is the proper representative of the helinet of;, k, on the plan it being the line of joint; e, m therefore is projected also by i, b, on the top of the helinet, and the line d, 0 by c, a — a, i and i, b coincide with c, b, the line of the joint on the convex side of the rail. Plate 60, Fig. 2. To find the butt-joint when the middle height is below a line, joining the other two. The lower twist of the rail, Fig. 1, Plate 57, is of this nature ; the face-mould for the same is Fig. 2, Plate 60 ; the plan of the rail at the bottom of the Fig. is supposed to lay perpendicular under the face-mould at the top, and each end unite at the top, and each over the corresponding ones at the base, r, s, the ordinates 1, 2, 3, 4 and 5; diagonal from those points raised perpendicular lines to the intersection of j, I, at the same diagonal, through the points of which trace the concave side of the face-mould. We present on Plate 61 a design in elevation for a store which may be constructed of cast iron. The inside of the front wall should be lined up with brick, or the piers supported as the work may require, by hollow cast-iron posts, 4x12 inches square. Fig. 1 shows the elevation, and Fig. 2 a plan of the ceiling of the entrance story. The patterns for the castings may be constructed in their several parts, so as to give a depth of sinkage to the panels, &c, as the taste of the builder may require. The patterns should be made so as to produce castings of about one-quarter of an inch in thickness. The elevation is drawn at a scale of one-eighth of an inch to a foot, and it is thought from this the different parts of the work may be delineated, so as to produce the desired result. Fig. 1 shows a design for a store, which may be of either stone or brick : this, like the one which precedes it, is drawn to a scale of one-eigMh of an inch to a foot, and will be understood without further explanation. On the elevation at Fig. 1 will be observed the horizontal lines at each of the two upper stories ; these breaks may be formed by breaking out the stones in the form )f a belt ; the projections need not be more than one inch. Should the building be constructed of bricks, the projections may be omitted, and the whole surface be made plain. The design of the projections in the stone being to give a better effect to the joints, if the joints are dispensed with, as would be the case were the building constructed of bricks, the projections would not be needed. Shows at Fig. 1 in elevation, and at Fig. 2 in plan, an Oriel Window, designed to be constructed on a level with the second story of a dwelling-house. The scale for delineating the respective parts of the same will be seen on the plate. stood, without further explanation. This villa may be constructed of bricks, if desired, and covered with cement. The walls should be, twelve inches thick, and should be made vaulted, or hollow. They may be so constructed, by laying one course in width on the outside face of the wall, and another on the inside, allowing as much space to intervene as will make the wall twelve inches in thickness. and thirty inches apart, the outer and inner parts of the walls should be tied together, to make the work secure. This may be done with bricks, or by pieces of sheet-iron of any width (more than one inch), and short enough to come within the faces of the walls. These pieces need not be bent in any way, but simply laid in the wall as the work progresses. The weight of the bricks above them will retain them in their position, and, by omitting to turn down the ends of them on either face of the wall, we avoid the rust which would come from them were they exposed to the action of the atmosphere. Should the building be left uncemented, the wall should be eight inches thick on the outside, with a space of three inches, and then a wall of four inches, or the width of a brick. By constructing the walls in this manner, we make the building both warm and dry, and thus avoid that serious objection to a brick building, namely, dampness. The idea in regard to thickness of -walls "of buildings left without cement, namely, that the exterior wall should be eight inches instead of four inches, was not advanced, in consideration that the cement would impart to the wall a strength which would not exist without it, but comes from the fact that water will pass through the joints of a four-inch wall in a storm, and the extra four inches are needed to remedy a defect which would not exist in a Avail covered with cement. A wall constructed hollow, and properly tied as directed, is much stronger than a solid wall ; and as dampness cannnot pass over an air space, the interior wall must be much drier than it could be was there a medium for the conduction of dampness, as brick and mortar. The remarks made in regard to the construction of brick dwelling-houses will apply with equal force to brick basements of wooden dwellinghouses. A basement of brick may be made to be as dry as though constructed of wood, if the precaution be taken to build them with a vault or air space, as directed. The wall will be stronger, will give a better support to the sills of the building, and may be made at nearly the same cost as though they were built solid. In ordinary cases, where the building is not too large, the wall need not be more than ten inches thick, making two inches of vaulting between the walls. Coming so near the ground, storms could not produce the effect on them which would be produced on a high structure, and therefore would be obviated the necessity of making them as thick as proposed for uncemented buildings. ARCHITECTURAL TERMS. Abacus. The upper member of the capital of a column, whereon the architrave rests. Scammozzi uses this term for a concave moulding in the capital of the Tuscan pedestal, which, considering its etymology, is an error. an arch springs. Acanthus. A plant, called in English Bear's breech, whose leaves are employed for decorating the Corinthian and Composite capitals. The leaves of the acanthus are used on the bell of the capital, and distinguish the two rich orders from the three others. Accompaniments. Buildings, or ornaments, having a necessary connection or dependence, and which serve to make a design more or less complete; a characteristic peculiarity of ornaments. extremities and apex of a pediment. Admeasuremc7it. Adjustment of proportions; technically, an estimate of the quantity of materials and labor of any kind used in a building. Alcove. The original and strict meaning of this word, which is derived from the Spanish Alcoba, is that part of a bed-chamber in which the bed stands, and is separated from the other parts of the room by columns or pilasters. ple with columns in the rear as well as in the front. Amphitheatre. A double theatre, of an elliptical form on the ground plan, for the exhibition of the ancient gladiatorial fights and other shows. or other figures. Annulet. A small, square moulding, which crowns or accompanies a larger. Also that fillet which separates the flutings of a column. It is sometimes called a list, or listella, — which see. a wall. Apophyge. That part of a column between the upper fillet of the base and the cylindrical part of the shaft of the column, which is usually curved into it by a cavetto. Arceostyle. That style of building in which the columns are distant four, and sometimes five, diameters from each other ; but the former is the proportion to which the term is usually applied. This columnar arrangement is suited to the Tuscan order only. Arcade. A series of arches, of apertures, or recesses ; a continued covered vault, or arches supported on piers, or columns, instead of galleries. In Italian towns the streets are lined with arcades, like those of Covent Garden and the Royal Exchange. Arch. An artful arrangement of bricks, stones, or other materials, in a curvilinear form, which, by their mutual pressure and support, perform the oflice of a lintel, and carry superincumbent weights, the whole resting at its extremities upon piers, or abutments. Arch-buttress, or Flying-buttress. (In Gothic architecture) an arch springing from a buttress, or pier, and abutting against a wall. in Grecian temples, used as a treasury, wherein were deposited the richest treasures pertaining to the deity to whom the temple was dedicated. the abacus of the capital. Astragal. From the Greek word for a bone in the foot, to which this moulding was supposed to bear a resemblance. A small moulding, whose profile is semi-circular, and which bears also the name of Talon, or Tondino. The astragal is often cut into beads and berries, and used in ornamental entablatures, to separate the faces of the architrave. Attic. A term that expresses anything invented or much used in Attica, or the city of Athens. A low story erected over an brder of architecture, to finish the upper part of the building, being chiefly used to conceal the roof, and give greater dignity to the design. Attic Order. An order of low pilasters, generally placed over some other order of columns. It is improperly so called, for the arrangement can scarcely be called an order. ed by a balustrade. Baluster. A small pillar, or pilaster, serving to support a rail. Its form is of considerable variety, in different examples. Sometimes it is round, at other times square ; it is adorned with mouldings, and other decorations, according to the richness of the order it accompanies. Band. A term used to express what is generally called a Face, or Facia. It more properly means a flat, low, square-profiled member, without respect to its place. That from which the Corinthian, or other modillions, or the dentils project, is called the modillion band, or the dentil band, as the case may be. plinth, die and cornice. Basil. A word used by carpenters, &c, to denote the angle to which any edged tool is ground and fitted for cutting wood, &c. palace, where kings administer justice. Basso Relievo, or Bas Relief. The representation of figures projecting from a background, without being detached from it. Though this word, iu general language, implies all kinds of relievos, from that of coins to more than one-half of the thickness from the background. the purpose of bathing. Batten. A scantling of stuff, from two to six inches broad, and from five-eighths to two inches thick, used in the boarding of floors ; also upon walls, in order to secure the lath on which the plaster is laid. is not perpendicular. Battlements. Indentations on the top of a parapet, or wall, first used in ancient fortifications, and afterwards applied to churches and other buildings. regular intervals. Boltel. (In Gothic architecture) slender shafts, whether arranged round a pier, or attached to doors, windows, &c. The term is also used for any cylindrical moulding. vaulted roof. Bossage. (A French term.) Any projection left rough on the surface of a stone for the purpose of sculpture, which is usually the last thing finished. polygonal pyramid, whether of stone or timber. Bracket. (In Gothic architecture) a projection to sustain a statue, or other ornament, and sometimes supporting the ribs of a roof. timber. Buttress. (In Gothic architecture) a projection on the exterior of a wall, to strengthen the piers and resist the pressure of the arches within. Cabling. The filling up of the lower part of the fluting of a column, with a solid cylindrical piece. Flutings thus treated are said to be cabled. Caisson. A name given to the sunk panels of various geometrical forms, symmetrically disposed in flat or vaulted ceilings, or in soffits, generally. umn or pilaster. Carpenter. An artificer whose business is to cut, fashion and join timbers together, and other wood, for the purpose of building ; the word is from the French charpentier, derived from charpentie, which signifies timber. Carpentry, or that branch which is to claim our attention, is divided into three principal heads, namely, Constructive, Descriptive, and Mechanical ; of these, Descriptive carpentrv shows the lines, or methods for forming every species of work in piano, by the rules of geometry ; Constructive carpentry, the practice of reducing the wood into particular forms, and joining the forms so produced so as to make a complete whole, according to the intention of the design ; and Mechanical carpentry displays the relative strength of the timbers, and the strains to which they are subjected by their disposition. Cartovch. The same as modillions, except that it is exclusively used to signify those blocks or modillions at the eaves of a house. [See Modillion.] Cincture. A ring, list or fillet, at the top or bottom of a column, serving to divide the shaft of a column from its capital and base. mental figure, with five leaves, or points. Column. A member in architecture of a cylindrical form, consisting of a base, a shaft, or body, and a capital. It differs from the pilaster, which is square on the plan. Columns should always stand perpendicularly. stone covering the top of a wall or parapet. Corbel. (In Gothic architecture) a kind of bracket. The term is generally used for a continued series of brackets on the exterior of a building supporting a projecting battlement, which is called a Corbel table. tecture. Cornice. The projection, consistiua or several members, which crowns or finishes an entaolaturo, or the body or part to which it is annexed. The pedestal. Corona. Is that flat, square, and massy member of a cornice, more usually called the drip, or larmier, whose situation is between the cymatium above and the bed-moulding below. Its use is to carry the water, drop by drop, from the building. Cyma, called also Cymatium, its name arising from its resemblance to a wave. A moulding which is hollow in its upper part, and swelling below. front. Decempeda. {Decern, ten, and pes, foot, Latin.) A rod of ten feet, used by the ancients in measuring. It was subdivided into twelve inches in each foot, and ten digits in each inch ; like surveyors' rods used in measuring short distances, &c. frieze. Dentils. Small, square blocks, or projections used in the bed-mouldings of the cornices in the Ionic, Corinthian, Composite, and sometimes Doric orders. some say four diameters. Die, or Dye. A naked square' cube. Thus the body of a pedestal, or that part between its base and cap, is called the die of the pedestal. Some call the abacus the die of the capital. or spire. Dooks. Flat pieces of wood of the shape and size of a brick, inserted in brick walls, sometimes called plugs, or wooden bricks. a plane perpendicular to the horizon. Embankments are artificial mounds of earth, stone, or other materials, made to confine rivers, canals, and reservoirs of water, within their prescribed limits ; also, for levelling up of railroads, &c. Entablature. The assemblage of parts supported by the column. It consists of three parts, the architrave, frieze, and cornice. Entasis. The slight curvature of the shafts of ancient Grecian columns, particularly the Doric, which is scarcely perceptible and beautifully graceful. Eustyle. That intercolunmiation which, as its name would import, the ancients considered the most elegant, namely, two diameters and a quarter of a column. Vitruvius says this manner of arranging columns exceeds all others in strength, convenience, and beauty. or broad fillet. Fane, Phane, Vane. (In Gothic architecture) a plate of metal, usually cut into some fantastic form, and turning on a pivot, to determine the course of the wind. boarding of wooden walls. Festoon. An ornament of carved work, representing a wreath or garland of flowers or leaves, or both, interwoven with each other. members in an order. Finial. (In Gothic architecture) the ornament, consisting usually of four crockets, which is employed to finish a pinnacle, gable, or canopy. it is joined to the main building. Flatning, in inside house painting, is the mode of finishing without leaving a gloss on the surface, which is done by adding the spirits of turpentine to unboiled linseed oil. or flowers on various parts of the building. Foreshorten. A term applicable to the drawings or designs in which, from the obliquity of the view, the object is represented as receding from the opposite side of the plane of the projection. being three barleycorns. Frame. The name given to the wood work of windows, enclosing glass, and the outward work of doors or windows, or window shutters, enclosing panels ; and in carpentry, to the timber work supporting floors, roofs, ceilings, or to the intersecting pieces of timbers forming partitions. Fret. A kind of ornamental work, which is laid on a plane surface ; the Greek fret is formed by a series of right angles of fillets, of various forms and figures. facade of a building. Frustum. A piece cut off from a regular figure ; the frustum of a cone is the part that remains when the top is cut off by an intersection parallel to its base, as the Grecian Doric column without a base. headed wall which covers the end of a roof. Gable Window. (In Gothic architecture) a window in a gable. These are generally the largest windows in the composition, frequently occupying nearly the whole space of the wall. Granite. A genus of stone much used in building, composed chiefly of quartz, feldspar and mica, forming rough and large masses of very great hardness. Groined Ceiling. A surface formed of three or more curved surfaces, so that every two may form a groin, all the groins terminating at one extremity in a common point. Ground Floor. The lowest story of a building. Ground Plane. A line forming the ground of a design or picture, which line is a tangent to the surface of the face of the globe. plastering. Guttce, or Drops. Those frusta of cones in the Doric entablature which occur in the architrave below the taenia under each triglyph. Hook-Pins. The same as Draw Bore-Pins, to keep the tenons in their place, while in the progress of framing : the pin has a head, or notch, in the outer end, to draw it at pleasure. Hyperthyron. The lintel of a doorway. Hypotrachelium. A term given by Vitruvius to the slenderest part of the shaft of a column where it joins the capital. It signifies the part under the neck. Inchnography. The transverse section of a building, which represents the circumference of the whole edifice ; the different rooms and apartments, with the thickness of the walls ; the dimensions and situation of the doors, windows, chimneys; the projection of columns, and everything that could be seen in such a section, if really made in a building. Impost. The layer of stone or wood that crowns a door-post or pier, and which supports the base line of an arch or arcade ; it generally projects, and is sometimes formed of an assemblage of mouldings1. into ten parts, or integers. Inclined Plane. One of the mechanical powers used for raising ponderous bodies, in many instances of immense weight ; a declivity of a hill, &c. Insular Column is a column standing by itself. Insulated. Detached from another building. Intaglio. Any thing with figures in relief ou it. Intercolumniation. The distance between two columns. Jambs. The side pieces of any opening in a wall, which bear the piece that discharges the superincumbent weight of such wall. more ornamental parts. Jointer. A tool used for straightening and preparing stuff for joints, &c. This jointer is about two feet eight or ten inches long. Lacunar, or Laquear. The same as Soffit. Lantern. (In Gothic architecture) a turret or tower placed above a building, pierced either with windows to admit light, or holes to let out steam. Leaves. Ornaments representing natural leaves. The ancients used two sorts of leaves, natural and imaginary. The natural were those of the laurel, palm, acanthus, and olive ; but they took such liberties with the form of these, that they might almost be said to be imaginary, too. Luffer Boarding. The same as blind slats. Machicolations. (In Gothic architecture) small openings in an embattled parapet, for the discharge of missile weapons upon the assailants. Frequently these openings are underneath the parapet, in which case the whole is brought forward and supported by corbels. Mechanical Carpentry. That branch of carpentry which teaches the disposition of the timbers according to their relative strength, and the strains to which they are subjected. Mediaeval Architecture. The architecture of England, France, Germany, &c, during the middle ages, including the Norman and early Gothic styles. Members. (Membrum, Latin.) The different parts of a building ; the different parts of an entablature ; the different mouldings of a cornice, &c. Metope. The square space between two triglyphs of the Doric opjer. It is sometimes left plain, at other times decorated with sculpture. Minerva Polios. A Grecian temple at Athens. Minute. The sixtieth part of the diameter of a column. It is the subdivision by which architects measure the small parts of an order. richer orders, resembling a bracket. Module. The semi-diameter of a column. This term is only properly used when speaking of the orders. As a semi-diameter it consists of only thirty minutes. [See Minute.] Mutule. A projecting ornament of the Doric cornice, which occupies the place of the modillion in imitation of the ends of rafters. or other solid. Obelisk. A tall, slender frustum of a pyramid, usually placed on a pedestal. The difference between an obelisk and a pyramid, independent of. the former being only a portion of the latter, is, that it always has a small base in proportion to its height. Order. An assemblage of parts, consisting of a base, shaft, capital, architrave, frieze, and cornice, whose several services, requiring some distinction in strength, have been contrived, or designed, in five several species, — Tuscan, Doric, Ijgnic, Corinthian, and Composite ; each of which has its ornaments, as well as general fabric, proportioned to its strength and character. the disposition of its several parts. Orle. (Ital.) A fillet or band under the ovolo of the capital. Palladio applies the term also to the plinth of the base of the column or pedestal. Ovolo. A moulding sometimes called a quarterround, from its profile being the quadrant of a circle. When sculptured it is called an Echinus, — which see. insulated, and comprised beneath a single roof. Pedestal. The substruction under a column or wall. A pedestal under a column consists of three parts, — the base, the die, and the cornice, or cap. Peripteral. A term used by the ancients to express a building encompassed by columns, forming, as it were, an aisle round the building. court, square, or cloister. Perspective. Is the science which teaches us to dispose the lines and shades of a picture so as to represent, on a plane, the image of objects exactly as they appear in nature. Pier. A solid between the doors or the windows of a building. The square, or other formed mass, or post, to which a gate is hung. into the ground. Pillar. A column of irregular form, always disengaged, and always deviating from the proportions of the orders ; whence the distinction between a pillar and a column. a church, or other building. Portico. A place for walking under shelter, raised with arches, in the manner of a gallery ; the portico is usually vaulted, but has sometimes a flat soffit, or ceiling. This word is also used to denote the projection before a church or temple, supported by columns. Purlins. Pieces of timber framed horizontally from the principal rafters, to keep the common rafters from sinking in the middle. Quatrefoil. (In Gothic architecture) an ornament in tracery, consisting of four segments of circles, or cusps, within a circle. Quirk Mouldings. The convex part of Grecian mouldings, when they recede at the top, forming a reenticent angle with the surface which covers the moulding. buildings or of their members. The corners. Radius, in Geometry, is the semi-diameter of a circle, or a right line drawn from the centre to the circumference ; in mechanics, the spoke of a wheel. stroy its effect. Reticulated Work. That in which the courses are arranged in a net-like form. The stones are square, and placed lozengewise. posite. Rose. The representation of this flower is carved in the centre of each face of the abacus in the Corinthian capital, and is called the rose of that capital. Rustic. The courses of stone or brick, in which the work is jagged out into an irregular surface. Also, work left rough, without tooling. each end. Salo?i. An apartment for state, or for the reception of paintings, and usually running up through two stories of the house. It may be square, oblong, polygonal, or circular. Scantling. The name of a piece of timber, as of quartering for a partition, when under five inches square, or the rafter, purlin, or pole-plate of a roof. than height, usually the same as plinth. Soffit. The ceiling or underside of a member in an order. It means also the underside of the larmier or corona in a cornice ; also, the underside of that part of the architrave which does not rest on the columns. [See also Lacunar.] of joists on both sides of it. Spandrel. (In Gothic architecture) the triangular space enclosed by one side of an arch, and two lines at right angles to each other, one horizontal, and on a level with the apex of the arch, the other perpendicular, and a continuation of the line of the jamb. above the architrave in the Doric order. Templet. A mould used by bricklayers and masons for cutting or setting the work; a short piece of timber sometimes laid under a girder. Tenon. A piece of timber the thickness of which is divided into about three parts. The two outside parts are cut away, leaving two shoulders; the middle part projects, and, being fitted to a mortise, is usually termed a tenon. in the bases of columns. Tracery. (In Gothic architecture) a term for the intersection, in various forms, of the mullions in the head of a window or screen. consisting of three cusps in a circle. Triglyph. The ornament of the frieze in the Doric order, consisting of two whole and two half channels, sunk triangularly on the plan. Trimens. Pieces of timber framed at right angles with* the joints against the wall, for chimneys, and well-holes for stairs. Trimmer. A small beam, into which are framed the ends of several joists. The two joists into which each end of the trimmer is framed are called trimming joists. is discharged. Trunk. [See Shaft.] When the word is applied to a pedestal it signifies the dado, or die, or body of the pedestal answering to the shaft of the column. Truss. When the girders are very long, or the weight the floors are destined to support is very considerable, they are trussed. level fillet of the corona. Vault. An arched roof, so contrived that the stones, or other materials of which it is composed, support and keep each other in their places. Well. The space occupied by a flight of stairs ; the space left in the middle, beyond the ends of the steps, is called the well-hole. Passed in 1851, with all the Amendments in full to 1853. Every person who shall by contract with the owner of any piece of land, furnish labor or materials for erecting: or repairing any building, or the appurtenances of any building-, on such land, shall have a lien upon the whole piece of land, in the manner hereinafter provided, for the amount due to him for such labor or materials. Sect. 2. Such lien shall not attach, unless the contract is made in writing, and signed by the owner of the land, or by some person duly authorized by him, and recorded in the registry of deeds for the county where the land lies. Sect. 3. The lien shall be dissolved at the expiration of six months after the lime, when the money due by the contract, or the last inslalment thereof, shall become payable, unless a suit for enforcing the lien shall have been commenced within the said six months Sect. 4. When any sum due by such contract shall remain unpaid, for the space of sixty days after the same is payable, the creditoi may, upon a petition to the court of common pleas for the county where the land lies, obtain a decree for the sale thereof, and for applying the proceeds to the discharge of his demand. Sect. 5. The petition may be filed in court, or in the clerk's office in vacation, and in either case, the filing of the petition shall be deemed the commencement of ihe suit. Sect. 6. The petition shall contain a brief statement of the contract on which it is founded, and of the amount due thereon, with a description of the premises which are subject to the lien, and all other material facts and circumstances, and shall pray l hat the premises may be sold, and the proceeds of the sale be applied to the discharge of the demand. Sect. 7. The court, in which the petition is entered, shall order notice to be given to the owner of the land, that he may appear and answer thereto, at a certain day in the same; term, or at the next term of the court, by serving him with an attested copy of the petition, wilh the order of the court thereon, fourteen days at least before the time assigned for the hearing, and the court shall also order notice of ihe filing of the petition to be given to all the other creditors who have a lien of the same kind upon the same estate, by serving them wilh the last mentioned order, fourteen days at least before the time assigned for the healing. Sect. 8. If it shall appear to the court that any of the parties so entitled to notice are absent, or that they cannot probably be found to be served with the notice, as before provided, the court may, instead of the personal notice before mentioned, or in addition thereto, order notice to all persons interested to be given, by publishing in some newspaper the substance of the petition, with the order of the court thereon, assigning the time and place for hearing the cause, or may order such other notice to be given, as shall, under the circumstances of the case, be considered most propjer and effectual Sitct. 9. If, at the time assigned for the hearing, it shall appear to the court that any of the persons interested have not had sufficient notice of the suit, the court may order further notice to effectual Sect. 10. At the time assigned for the hearing of the cause, or within such further time as the court shall allow for that purpose, every creditor, having a lien of the kind before mentioned upon the same estate, may appear and prove his claim, and the owner shall be admitted to deny and disprove the same, and also each of the said creditors shall have a right to contest the claim of every other creditor, and the court shall hear and determine the several claims, in a summary manner, either with or without a jury, as the case may require. StcT. 11. Every material question of fact, arising in the case, shall be submitted to a- jury, if required by either party, or if it shall be thought proper by the court, and such trial shall be had upon a question stated, or an issue framed, under the direction of the court, or otherwise, as the court shall order. Sect. 12. The court shall examine all the claims that shall be presented, and shall ascertain and determine the amount due to each creditor who has a lien, of the kind before mentioned, upon the estate in question, and every such claim that is due absolutely and without any condition, although not then payable, shall be allowed, with a rebate of interest to the time when it would become payable. Sect. 13. When the owner of the land shall have failed to perform his part of the contract, and by reason thereof the other party shall, without his own default, have been prevented from completely performing his part, he shall be entitled to a reasonable compensation for as much thereof as he has performed, in proportion to the price stipulated for the whole, and the court shall adjust his claim accordingly. Sect. 14. If the lien should be established in favor of any of the creditors whose claims are presented, whether the petitioning creditor or any other, the court shall order the sale of the premises to be made by any officer, who is authorized to serve any civil process between the same parties. Sect. 15. If any part of the premises can he separated from the residue and sold, without damage to the whole, and if the value thereof should be sufficient to satisfy all the debts proved in the case, ihe court may order a sale of that part, if it shall appear to be most for the interest of all the parties concerned. Sect. Id. The officer who makes the. sale, shall give notice of the time and place appointed therefor, in the manner prescribed in relation to the sale Oil execution of a right of redeeming mortgaged lands, unless the court shall ordet other or different notice to be given. Sect. 17. All lands, sold under such order of the court, may, be redeemed in like manner, and upon the same terms, as are provided in the case of a sale on execution of the right of redeeming mortgaged lands. Sect. 18. If the claims against the estate are all ascertained,, at the time of ordering the sale, the court may at the same time order the officer to pay over and distribute the proceeds of the sale, after deducting all lawful charges and expenses, to and among the several creditors, to the amount of their respective debts, if there is sufficient therefor, and if there is not sufficient, then to divide and distribute the same among the creditors, in proportion to the amount due to each of them. Sect 19. If the claims are not all ascertained when the sale is ordered, or if for any other reason, the court should find it necessary or proper to postpone the order of distribution, they may direct the officer to bring the proceeds of the sale into court, there to be disposed of according to the decree of the court ; and if by reason of the claims of attaching cfediiors, or for any other cause, the whole cannot be conveniently distributed at once, the court may make two or more successive orders of distribution, as the circumstances may require. Sect. '20. If there be any surplus of the proceeds of the sale, after making all the payments before mentioned, it shall be forthwith paid over to the owner of the land, but such surplus, before it is so paid over, shall be liable to he attached or taken in execution, in like manner as if it proceeded from a sale made by the officer on an execution. Sect. 21. If the land, to which any such contract relates, shall be under attachment at the time of recording the contract, the attaching creditor shall be preferred, to the extent of the value of the land and buildings, as they may be when the contract shall be recorded, and the court shall ascertain, by a jury or otherwise, as the case may require, what proportion of the proceeds of the sale shall be held subject to the attachment, as derived from the value of the premises, when the contract was reoorded. Sect. 22. If the attaching creditor, in such a case, shall recover judgment in his suit, he shall be entitled to receive on his execution the said proportion of the proceeds, that are held subject to his attachment, or as much thereof as may be necessary to satisfy his execution, and the residue, if any, of the proceeds of the sale, shall be applied in the same manner as if there had been no such attachment. Sect. 23. If the land, to which the contract relates, shall be aitached after the recording of the contract, the proceeds shall be applied, after discharging all prior liens and claims, to satisfy the execution of such attaching creditor, in like manner as is provided in the ninety-seventh chapter, in the case of two or more successive attachments, or seizures in execution, of a light of redemption, or of a share in any incorporated company. Sect. 24. If an attachment is made after the recording of such a contract, and if after the attachment another like contract should be recorded, the creditor in the latter contract shall be entitled to be paid only out of the residue of the proceeds, if any, remaining after satisfying the attaching creditor, and also paying all that is due on the contracts that were recorded before the attachment. Sect. 25. When there are several attaching creditors, they shall, as between themselves, be entitled to be paid according to the order of their respective attachments, but when several creditors, who are entitled to the lien provided for in this chapter, have all equal rights as between themselves, and the fund shall be insufficient to pay the whole, they shall share it equally, in proportion to their respective debts. Sect. 26. If the person who procures the work to be done, has an estate for life only, or any other estate less than a fee simple, in the land on which the work is to be done, or if the land, at the time of recording the contract, is mortgaged, or under any other incumbrance, the person who procures the work to be done shall nevertheless be considered as the owner, for the purposes of this chapter, to the extent of his right and interest in the land, and the lien before provided for shall bind his whole estate and interest therein, in like manner as a mortgage would have done, and the creditor may cause the right of redemption, or whatever other right or estate the owner had in the land, to be provisions of this chapter. Sect. 27. If the person indebted in any such contract shall die, or shall convey away his estate, before the commencement of a suit on the contract, the suit may be commenced and prosecuted against his heirs, or whoever shall hold the estate, which he had in the premises, at the time of making the contract ; or if a suit is commenced in his life time, it may be prosecuted against his heirs or assigns, in like manner as if the estate had been mortgaged to secure the debt. Sect. 28. If the creditor in such contract shall die, before the commencement of a suit thereon, the suit may be commenced and prosecuted by his executors or administrators, or if commenced in his life time, it may be prosecuted by them, as it might have been by the deceased, if living. Sect. 29. Any party interested in a suit brought under this chapter may appeal to the supreme judicial court, from the final decree or judgment of the court of common pleas, and the appeal shall be conducted and prosecuted, in the same manner, substantially, as is prescribed in relation to common civil actions, and the cause shall be thereupon heard and determined in the supreme judicial court, according to the provisions of this chapter. Sect. 30. If it appear, in any stage of the proceedings under this chapter, that the suit was commenced by the petitioning creditor before the expiration of the sixty days, or after the expiration of six months, in that behalf before limited, or if the petitioning creditor should become nonsuit, or should from any cause fail to establish his claim, the suit may nevertheless be prosecuted by any other creditor having such a lien, in the same manner as if it had been originally commenced by the latter creditor; provided, the circumstances of* the case are such, that he might then, or at any time after the commencement of the original suit, have commenced a like suit on his own claim. Sect. 31. If the suit is commenced by the petitioning creditor, before the expiration of the sixty days, in that behalf limited, his claim may nevertheless be allowed, if he is otherwise entitled thereto, and if the suit is carried on by any other creditor, as provided in the preceding section, but he shall not in such case be entitled to any costs, and he may be required to pay the costs, that shall be incurred by the debtor, or any part thereof, as the court shall think reasonable. Sect. 32. The costs in all other respects shall be subject to the discretion of the court, and shall be paid out of the proceeds of the sale, or by any of the parties in suit, as justice and equity may require. Sect. 33. Nothing contained in this chapter shall be construed to prevent any creditor in such contract from maintaining an action thereon at the common law, in like manner as if he had no such lien for the security of his debt. Sect. 34. The register of deeds shall receive and record all contracts, of the kind mentioned in this chapter, that shall be delivered to him for that purpose, and he shall be entitled to the same fees therefor, as for recording deeds or other papers of equal length. Sect. 35. When any debt, secured by such lien, shall be fully paid, the creditor shall, at the expense of the debtor, enter on the margin of the registry, where the contract is recorded, a discharge of his said lien, or shall execute a deed of release thereof, in like manner, as is provided in relation to the release of mortgages, after the payment thereof. Sect. 36. Every petition, filed in pursuance of this chapter, shall be indorsed in the same manner as is required with Tespect to original writs, and all the regulations concerning the indorsement of original writs, contained in the ninetieth chapter^shall apply to the indorsement of such petitions. LIEN LAW IN FULL TO 1854. Section 1. Any person who shall actually perform labor in erecting, altering or repairing any building, by virtue of any contract with the owner thereof, or other person who has contracted with such owner for erecting, altering or repairing such building, or for the purchase of the land for the purpose of erecting and building thereon, shall have a lien to secure the payment of the wages due or owing him for such labor, by him personally so performed upon such building, and the lot of land on which the same stands, and upon the right of redeeming the same when under mortgage. Sect. 2. Such lien shall be dissolved unl.ess the person who may avail himself of the benefit of this act shall, within sixty days after such labor is performed as aforesaid, file, in the office of the registry of deeds for the county where the land lies, a certificate* containing a just and true account of the demand justly due to him after all just credits given, which is to be a lien upon such land and buildings, and a true description of the property, or so near as to identify the property, to which the lien is intended to apply, with the name of the owner or contractor, or both, if known, which shall in all cases be subscribed and sworn to by himself, or some credible person in his behalf, which certificate shall be recorded by the register of deeds, who shall be entitled to the same fees as for recording deeds of equal length. Sect. 3. Unless a suit for enforcing the lien shall have been commenced within seventy days after the time when such labor is performed, such lien shall be dissolved. Sect. 4. Such lien may be enforced by petition to the court of common pleas for the county where the land lies, in the manner provided by the fifth and subsequent sections of the one hundred and seventeenth chapter of the Revised Statutes. Sect. 5. When any debt secured by such lien shall be fully paid, the creditor shall, at the expense of the debtor, enter on the margin of the registry, where the said certificate is recorded, a discharge of his said lien, or shall execute a deed of release thereof, in like manner as is provided in relation to the release of mortgages after the payment thereof. [May 24, 1851.] cents, being the amount of wages due me in my own right, after deducting all just credits, for work done and performed in building [altering or repairing, as the case may be] said premises, according to the following bill :— Be it enacted, eye., as follows : Sect. 1. Any person to whom any money shall be due for labor or for labor and materials expended in the erection or repair of any building by virtue of any contract with the owner thereof, or other person having authority to contract for such labor, shall have a lien to secure the payment of such money, not exceeding the amount of said contract upon such building and the lot of land on which the same stands, to the same extent, and to be enforced in the same manner, as is provided for labor in the act entitled " An act to secure to mechanics and laborers their payment for labor by a lien on real estate," passed in the year one thousand eight hundred and fifty-one ; provided, however, that no lien for materials shall attach to any building or land, unless the person or persons claiming such lien shall, before furnishing such materials, have given notice in writing to the owner of the land and to the person who has contracted with the owner of the land, that he or they intend to claim such lien for materials furnished as aforesaid ; and provided, further, that nothing contained in this act or in the act to which this is in addition, shall be so construed as to affect any mortgage actually existing and duly recorded prior to the date of the contract under which the lien is claimed. Sect. 2. Any number of persons who have actually performed labor on one or more buildings upon different lots of lands where the labor was performed for the same owner, contractor, or other person, may all join in the same petition for their respective liens, and the same proceedings shall be had in regard to the respective rights of each petitioner, and the respondent may defend, as to each petitioner, in the same manner as if he had severally petitioned for his individual lien ; provided, that each petitioner so joined may be a witness for his joint petitioners, but not in his own case, subject only to the same exceptions as would invalidate his testimony if he were not joined in said petition. [Approved, May 21, 1852.] MAINE. In the State of Maine, all persons furnishing materials, or labor, in building or repairing a vessel, may secure a lien by attachment within four days after said vessel is launched or repaired. And a lien on a house, or other building, can be secured bv attachment within ninety days from the time the payment for such labor or materials become due. building, is a lien on the land and building. A claim of a sub-contractor for the amount of S 50.00, or more, is a lien upon the house and land, provided the Contract between the sub-contractor and original contractor was in writing, and the other party to such original contract shall, in writing, consent to such sub-contract. No debt, as above, can remain a lien longer than sixty days after the building is finished, unless a certificate in writing, describing the premises and the amount claimed, is lodged with the town clerk, to be recorded after first having been subscribed and sworn to, as the amount justly due as near as can be ascertained. NEW YORK. The contractor, laborer, or a furnisher of materials in building a house, &c, must file, in the office of the clerk of the county, a copy of his contract, but if he have no written contract, he will file the specification of the work or materials, with the prices agreed on, and within twenty days after the contract, or commencement of the labor, &c , he will give notice thereof personally to the owner, or his agent. The lien will continue one year from the filing or serving of notice. the debt was contracted. In the city of New York the owner of -a building on receiving from the laborers, journeymen, &c, an attested account of Ihe value of their services, may retain the amount due to them by the builder, for their benefit. PENNSYLVANIA. In the cities of Philadelphia, Harrisburg, Pittsburg, and many counties, persons furnishing labor or materials for the erection of a house, or other building, have a lien for such work or materials f irnished in its erection, for six months after the work is finished, or the materials furnished, which may be continued five years by filing their claim in the office of the Prothonotary, and five years longer by legal process in the proper courts, and until satisfied. MISSOURI. Contractors have a lien for material furnished and work done. To secure it, an account of such lien, under oath, must be filed with the clerk of the circuit court of the county where the building is situated within six months after the materials have been furnished, or labor done. NEW JERSEY. A lien on buildings in the counties of Hunterdon, Somerset, Monmouth, Salem, Cumberland, the township of Paterson, Manchester, &c, exists for two years, if the claim be filed with the clerk of the common pleas within six months after the materials were furnished or work performed. Action must be commenced within one year from the time the work was completed. Journeymen being refused their pay by the contractor, can obtain it from the owner. In the city of Newark, in the township of Elizabeth, Railway, Belville, Woodbridge and South Brunswick, a specification of the work or materials with the prices agreed upon, must be filed in the office of the clerk of the county, and the owner notified personally, within fifteen days after the making of such contract. If so filed, the lien will continue six months after the completion of the building.. pairing of a house, manufactory, boat or vessel, may obtain a lien by depositing a written account, sworn to, and also a copy of the contract, if there be one, with the Recorder of the county, within four months from the time of performing such labor or furnishing such materials. INDIANA. Lien on lands and tenements exists where the sum exceeds thirty dollars. A bill in chancery must be filed in the circuit court within one year from the completion of the work, or furnishing of materials. Journeymen have a lien upon the owner, on giving him a written notice of the amount due. ILLINOIS. Lien on lands and tenements exists, provided the time of completing contract does not exceed three years, nor the time of payment one year. Landlords have a lien on crops growing for rent. Liens upon boats and vessels must be enforced within three months from time of indebtedness, for building, repairing and equipping such boats, and also by the engineers, pilots, &c. WISCONSIN. Lien on buildings exists, if notice be given to the owner in writing, by the person employed, within thirty days after being so employed. Action must be commenced within one year, or lien is dissolved. MARYLAND. In the city of Baltimore and county of Harford, written notice must be given to the owner of the building within thirty days after making the contract, of his intention to claim the benefit of lien. Every debt against such building shall be a lien for six months after the work is completed, though no claim be filed. CALIFORNIA. All boats and vessels navigating the waters of the State are liable for debts contracted by the master, owner, agent or consignee, for supplies, work, labor, building, repairing, fitting out, furnishing or equipping such boat or vessel ; for wharfage and anchorage ; for non-performance and mal-performanee of contracts touching the transportation of property and persons ; and for injuries to persons and property. The wages of seamen and boatmen to be first paid. Suit must be instituted within fifteen days. Lien Laivs exist in some of the Southern and Western States, not mentioned in the foregoing list, which secure the amounts due to contractors, furnishers of materials, and workmen, engaged in the erection of buildings, and also those engaged in building, repairing, equipping, or performing duty on board of steamboats, which do not materially differ from the above abstracts.	57,157	common-pile/pre_1929_books_filtered	modernarchitecto00shaw_0	public_library	public_library_1929_dolma-0005.json.gz:1125	https://archive.org/download/modernarchitecto00shaw_0/modernarchitecto00shaw_0_djvu.txt
t767OcwMgpbEqP99	Early World Civilizations	174 Module Overview Module 10 contains the following content – all original by author or contained in the Lumen textbook. Textbook Reading – Chapter 10 Discussion forum: This discussion will be based on the textbook reading for the chapter. For your initial post in this discussion please answer the following questions: “Based on the information in this chapter, what do you think is the key to running a successful Chinese dynasty? What were the most important policies that successful dynasties enacted to keep their power?” Initial posts must be at least 200 words in length and have at least one quote from the textbook. After posting your initial post you are required to reply to at least one other student. Replies must be at least 100 words in length and have at least one new quote from the textbook (not a quote you used in your initial post and not a quote that is in the post you are replying to). All posts must be made by the deadline for the discussion forum to receive full credit. Short Essay: Submit your short essay for Module #1 here. The question for this essay is: “Out of all the dynasties listed in this chapter, which do you think was the most successful? List specific reasons why you think that dynasty was more successful than the other dynasties covered in this chapter.” This essay must be at least 500 words in length and have at least one quote from the textbook to recieve full credit. Quiz: Some questions are from the Boundless text, some are original. The course Map links to the quiz.	351	common-pile/pressbooks_filtered	https://library.achievingthedream.org/herkimerworldcivilization/chapter/module-overview-10/	pressbooks	pressbooks-0000.json.gz:77520	https://library.achievingthedream.org/herkimerworldcivilization/chapter/module-overview-10/
_UGlfyWMCGbvXLTR	10.1: Example- Equations of Motion in Classical Mechanics	10.1: Example- Equations of Motion in Classical Mechanics The above standard formulation of the initial-value problem can be used to describe a very large class of time-dependent ODEs found in physics. For example, suppose we have a classical mechanical particle with position $\vec{r}$, subject to an arbitrary external space-and-time-dependent force $\vec{f}(\vec{r},t)$ and a friction force $-\lambda d\vec{r}/dt$ (where $\lambda$ is a damping coefficient). Newton's second law gives the following equation of motion: \[m \frac{d^2 \vec{r}}{dt^2} = - \lambda \frac{d\vec{r}}{dt} + \vec{f}(\vec{r}, t).\] This is a second-order ODE, whereas the standard initial-value problem involves a first-order ODE. However, we can turn it into a first-order ODE with the following trick. Define the velocity vector \[\vec{v} = \frac{d\vec{r}}{dt},\] and define the state vector by combining the position and velocity vectors: \[\vec{y} = \begin{bmatrix}\vec{r} \\ \vec{v}\end{bmatrix}.\] Then the equation of motion takes the form \[\frac{d\vec{y}}{dt} = \frac{d}{dt}\begin{bmatrix}\vec{r} \\ \vec{v}\end{bmatrix} = \begin{bmatrix}\vec{v} \\ - (\lambda/m) \vec{v} + \vec{f}(\vec{r}, t)/m\end{bmatrix},\] which is a first-order ODE, as desired. The quantity on the right-hand side is the derivative function $\vec{F}(\vec{y},t)$ for the initial-value problem. Its dependence on $\vec{r}$ and $\vec{v}$ is simply regarded as a dependence on the upper and lower portions of the state vector $\vec{y}$. In particular, note that the derivative function does not need to be linear, since $\vec{f}$ can have any arbitrary nonlinear dependence on $\vec{r}$, e.g. it could depend on the quantity $\|\vec{r}\|$. The "initial state", $\vec{y}(t_0)$, requires us to specify both the initial position and velocity of the particle, which is consistent with the fact that the original equation of motion was a second-order equation, requiring two sets of initial values to fully specify a solution. In a similar manner, ODEs of higher order can be converted into first-order form, by defining the higher derivatives as state variables and increasing the size of the state vector.	396	common-pile/libretexts_filtered	https://phys.libretexts.org/Bookshelves/Mathematical_Physics_and_Pedagogy/Computational_Physics_(Chong)/10%3A_Numerical_Integration_of_ODEs/10.01%3A_Example-_Equations_of_Motion_in_Classical_Mechanics	libretexts	libretexts-0000.json.gz:6312	https://phys.libretexts.org/Bookshelves/Mathematical_Physics_and_Pedagogy/Computational_Physics_(Chong)/10%3A_Numerical_Integration_of_ODEs/10.01%3A_Example-_Equations_of_Motion_in_Classical_Mechanics
MmMbqhP60a2momHb	6.2: Western Europe and Byzantium circa 500-1000 CE	6.2: Western Europe and Byzantium circa 500-1000 CE December 25, 800 CE, the cavernous interior of St. Peter’s Church smelled faintly of incense and the open space of the nave was packed with the people of Rome. At the eastern end of the church, King Charles of the Franks knelt before the pope. The Frankish king wore the dress of a Roman patrician: a tunic of multi-colored silk, embroidered trousers, and a richly embroidered cloak clasped with a golden brooch at his shoulder. As King Charles knelt, the pope placed a golden crown, set with pearls and precious stones of blue, green, and red, on the king’s head. He stood to his full height of six feet and the people gathered in the church cried out, “Hail Charles, Emperor of Rome!” The inside of the church was filled with cheers. For the first time in three centuries, the city of Rome had an emperor. Outside of the church, the city of Rome itself told a different story. The great circuit of walls built in the third century by the emperor Aurelian still stood as a mighty bulwark against attackers. Much of the land within those walls lay empty. Although churches of all sorts could be found, pigs, goats, and other livestock roamed through the open fields and streets. Where once the Roman forum had been a bustling market, filled with merchants from as far away as India, now the crumbling columns of long-abandoned temples looked out over a broad, grassy field where shepherds grazed their flocks. The fountains that had once given drinking water to millions of inhabitants now went unused and choked with weeds. The once-great baths that had echoed with the lively conversation of thousands of bathers stood only as tumbled down piles of stone that served as quarries for the men and women who looked to repair their modest homes. The Coliseum was now honeycombed with houses built into the tunnels that had once admitted crowds to the games in the arena. And yet within this city of ruins, a new Rome sprouted from the ruins of the old. Just outside the city walls and across the Tiber River, St. Peter’s Basilica rose as the symbol of Peter, prince of the Apostles. The golden-domed Pantheon still stood, now a church of the Triune God rather than a temple of the gods of the old world. And, indeed, all across Western Europe, a new order had arisen on the wreck of the Roman state. Although this new order shared the universal ideals of Rome, its claims rested upon the foundations of the Christian faith. How this post-Roman world had come about is the subject to which we shall turn.	586	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Courses/Mizzou_Academy/World_History_A_B/06%3A_Western_Europe_and_Byzantium_(circa_500-1000_CE)/6.02%3A_Western_Europe_and_Byzantium_circa_500-1000_CE	libretexts	libretexts-0000.json.gz:19626	https://socialsci.libretexts.org/Courses/Mizzou_Academy/World_History_A_B/06%3A_Western_Europe_and_Byzantium_(circa_500-1000_CE)/6.02%3A_Western_Europe_and_Byzantium_circa_500-1000_CE
jLIKmti06_SkZnye	Illustrated catalogue of photographic equipments and materials for amateurs / E. & H.T. Anthony & Co.	from those presented herein. When the price is given for camera, holder and carrying case, it includes neither lens nor tripod. Our list has been prepared with great care, and we have endeavored to be explicit enough to enable any one to select such articles as will make a harmonious equipment. The sizes given are the largest that each camera will admit of, but smaller plates can be used in each by means of our inside kits, for each of which we give the outside dimensions with size of plate that can be used in same. As our equipments are sold at a less price than the several parts could be bought for separately and combined, we suggest the purchase of such complete, wherever possible, as a matter of economy. Where lenses different from those accompanying the equipments are required, the price for making up such special outfit can readily be reached, as prices are given for the different parts that can be supplied separately. these negatives. The cost of making subsequent pictures would be trifling, as the developing and printing outfits include trays, graduates, funnels, etc., that will last for years, and sufficient chemicals for making several dozen additional negatives and prints. Read Carefully these Few Facts. Presumably the reader of the following pages knows something of the interesting art for which the articles enumerated in this catalogue are provided. If not, he can acquire a general idea of it from what follows, and we shall be pleased, on receipt of fifty cents, to mail to any address a book, in which all the details are given, entitled How to Make Photographs ; A Manual for Amateurs, by T. C. Roche, recently published by our house. It has been penned and edited by eminent theoretical and practical photographers, and with the purpose of stating in the most simple and concise language, everything necessary for any one to know who may be disposed to engage in photography as an amateur. It will be found equally serviceable to those who desire to practice the art as an aid in their business or profession, and all its statements may be implicitly relied on for accuracy and practicability. The introduction of the gelatino-bromide dry plate has so revolutionized photography that but little preliminary knowledge of it is now essential ; in fact, it is astonishing what can be accomplished by totally inexperienced amateurs who may exercise a little taste and judgment. It is scarcely to be supposed that success should always attend one's first efforts, but rapid progress can generally be made by old or young, lady or gentleman, who may manifest the slightest disposition to excel. Unlike the old " wet " plate, the gelatino-bromide process has the advantage of admitting a much wider latitude of exposure — that is to say, the actual time which the sensitive plate may now be subjected to light, though still important, is far less so than by the old collodion process, and the subsequent operations are free from the former objections of complexity, uncertainty and stains. The apparatus and chemicals required are also few and inexpensive, and there is nothing which the veriest tyro in chemistry cannot readily master. requirements of the public. Unfortunately the increasing demand has led many persons to engage in the manufacture and sale of apparatus and materials that are quite inadequate for the attainment of satisfactory results. We therefore point with pride to the intrinsic excellence of every item in the following list — the outcome of more than forty-eight years' diligent effort and experience in the preparation of photographic supplies. large picture cannot be made with a small camera. Remember, we do not make a single toy ; all our cameras are practical working instruments such as are in constant use by professional photographers. All are fitted with our Patent Double Dry Plate Holders, which are by far the lightest, tightest and handiest holders made, and have done as much as any other one thing toward giving popularity to our equipments. The equipments are fitted with fine single achromatic lenses, which (with the exception of the 4x5) are provided with changeable diaphragms, so that the time of exposure may be varied to suit the subject. They are adapted for landscapes and out-of-door groups and in a good light require but a second's time (or even less) to make a picture. Amateurs who aim to excel, and with whom the cost is a secondary consideration, are invited to examine the more expensive double achromatic lenses described in the following pages. absolutely the best in market. With these the very finest results are possible. In buying do not forget that you are not going to make an experiment. Your success is assured if you follow the printed directions. Thousands have succeeded before you with only the ordinary amount of brains, and some with less than is allowed to mankind generally. So when you buy, buy as good an outfit as you can afford. With a cheap instrument you can do good work, but with the better grades you can do better work more easily. First decide what size you want, then get the best you can afford of that size. With these few hints and explanations we take pleasure in opening to your view and for your consideration the pages of this little book, with the further assurance that everything therein mentioned is guaranteed to be exactly as described. Focusing Cloth. THIS EQUIPMENT is intended as a means of learning the elementary steps of photography by practical working, at an extremely low price, and, while none of the several parts of the equipment are made with elaborate finish or ornamentation, they are all practicable and good results can be obtained with them, as the pictures produced by the equipment demonstrate. The equipment comprises a 4x5 camera, with lens, folding tripod, and complete developing and printing outfit, as indicated in above cut. THE CAMERA which forms a part of this Equipment is of mahogany, well finished and thoroughly practicable ; it is adapted to making of pictures either vertically or horizontally. The equipment comprises, besides the camera, one patent double zephyr dry plate holder, a single achromatic lens, tripod and carrying case. Manhattan Equipment No. 3 is similar to No. 2 of the same name, and has in addition to the lens for 5x8 pictures, a pair of fine achromatic lenses for making either stereoscopic views on a 5x8 plate, or two 4x5 views on a plate 5x8 inches. The price, including the lenses, tripod and carrying case, is $16.50. The lens for making the 5x8 picture may be Champion Equipment. THE CAMERA included in this Equipment is of mahogany, with fine varnish finish, and is provided with folding bed (made rigid by the use of our patent clamps), rising front and swing back, and is adapted to either vertical or horizontal pictures. In addition to the O. N. A. Equipment. THE CAMERA which forms a part of this Equipment, is of highly polished mahogany, the metal work having the draw file finish like that on the finest mathematical instruments, and being lacquered to prevent tarnishing. It is provided with a bed which folds for convenience in packing and has single swing and rising front. This camera can be used either vertically or horizontally. The outfit includes, beside the camera, a fine single achromatic lens, a patent zephyr double dry plate holder, an improved triple jointed climax tripod and carrying case, except in the case of the two sizes 6^x8^4 and 8xio, which have our patent telescopic folding tripod, as stated below. Catalogue for Amateurs. O. N. A. equipments, numbers 7 B and 8 B, are similar to those previously described, except that they are fitted with a patent telescopic folding tripod, as shown in the cut. beside the camera, a patent Eclipse double dry plate holder, fine single achromatic lens, Triplex tripod and canvas carrying case, which contains all the above named articles except the tripod legs. THE several parts which make up this very compact equipment are as follows : A handsome mahogany camera, suitable for views 3^ x 4^2, a fine single achromatic lens, patent double dry plate holder and a sole leather carrying case with shoulder strap for co^ venience in carrying, and a clamp for attaching camera to bicycle when in use. The weight of this complete outfit is exactly 2 pounds. The N. P. A. Camera. THIS is a highly polished mahogany camera with patent swing back rising front, folding bed, patent clamp hooks (to make the bed rigid), extra front and stereoscopic partition. The metal work has the draw file finish, similar to that on the finest mathematical instruments. By means of a plate on the side, this camera can be reversed on the tripod and used to make a vertical picture. This is the same camera as used in our O. N. A. Equipment. Prices, including camera as above, one patent double Zephyr dry plate holder and carrying case: The Patent Bijou Camera. THIS LITTLE CAMERA is one of the neatest of its kind ever made. When folded, it measures 5x5x3^ inches, and can readily be put in an ordinary hand-grip or may even be carried in the overcoat pocket. It weighs only 14^ ounces, and the holders are correspondingly light and compact. It has a sliding front, hinged ground glass, and folding bed, which is provided with a novel arrangement for fixing it in position, enabling the operator to adjust it in a few seconds. It is made of highly polished mahogany, with flexible bellows ] and brass mountings, making a remarkably elegant little instrument. As the plate is the same size as those used with magic lanterns, slides may be made from them by contact printing in an ordinary printing frame. By using bromide paper in connection with a Cooper enlarging lantern, the pictures may be made as large as desired. For tourists, to whom weight and bulk are objections, this camera is of especial value. Price of camera, with one double holder, .... $ 9.00 8 x 10 It is provided with rising front and single swing and is adapted to front focus, having the double rack and pinion movement. The ground glass is fitted with the patent spring actuated movement which keeps it always attached to the camera without being in the way of the operator. The camera may be used for making pictures either vertically or horizontally by means of a plate on the side. The price includes camera, one Eclipse double dry plate holder and canvas carrying THESE CAMERAS are made in the best possible manner, and of first quality mahogany highly polished ; the metal work having the draw file finish, the same as is used on the finest mathematical instruments. They have single and double swing backs, cone bellows and folding beds ; are very light, compact and strong. Their peculiar construction admits of making the pictures either vertically or horizon- The front end of the bellows being arranged so as to revolve in a light framework which runs on the two hollow upright brass rods, when the rear of the camera is separated from the bed, the glass is hinged to the camera. Several new features have been availed of in the construction of this camera, to wit : In all sizes except 4x5 the bed may be instantly rendered rigid, without the use of screws, by means of a brace of patent hooks that hold the two sections of the bed with great firmness. In the case of the 4x5 size, the bed is fastened with a sliding plate. The rabbet commonly found on the plate holder is dispensed with, and instead it is placed on the camera, thus saving the otherwise additional weight rendered necessary for twelve such rabbets when made on the plate holders (two on each of the six usually carried), and the no inconsiderable item of three-fourths of an inch in bulk. The plate holders are made of hard wood, with metal carriers for the plates, and fitted with all the later improvements. The Novelette occupies less space than any other view camera of the same capacity except our Fairy, and is packed in our telescopic brass bound Canvas Carrying Case. Front Focus Novelette Camera. WITH the exception of the regular Novelette, Fairy and Phantom Cameras, this is the lightest and most compact reversible Cam • era extant. The body of the Camera is made of same shape as the holder, and is reversed more easily and quickly than any other in the market. It occupies only one-half the space necessary for other reversible Cameras for the same size plate, and is only two-thirds the weight. always just where it is wanted. The metal work has the straight line or draw file finish, same as used in the finest mathematical instruments. Each size admits the use of lenses of longest and shortest focus for the size plate to which the Camera is adapted. There are no loose pieces or sections, and in this respect also it differs from all other reversible Cameras of other makes, being complete in itself. It is fitted with the Eclipse double dry plate holder, which is included in price of Camera quoted below. Also one of our telescopic brass bound Canvas Carrying Cases. The Anthony Compact Camera IS a recent improvement in folding cameras, similar in effect to the noted English makes. This camera is constructed with reversible back, which makes it almost square when folded, and measures (5x8 size) gi x 9^ x 3^ inches The bed telescopes with rack and pinion, and when closed for carrying, forms the outside of the box. The bellows has an extension (5x8 size) of 16 inches, and the telescopic bed makes it capable of use with very short focus lenses. The tripod top is built into this camera, and is of brass, arranged in such a manner that it revolves freely, thus giving the advantage of changing the field without moving the tripod legs. The ground glass is attached with our patent spring action, which keeps it out of the operator's way and prevents its becoming detached from the box, and the entire instrument, with ground glass and double holder, weighs only 5^ pounds. The Vincent Camera. IS a new style of camera, constructed on the folding principle, the bed being in two solid sections which telescope, one into the other and fold closely to the frame, forming the back of the closed camera. The with reversible backs, which render them nearly square in shape and very convenient for carrying. The ground glass is attached to camera by means of our patent springs, and is therefore not liable to get in the way or become detached. The bellows has a capacity, in the 5x8 size, of extension to the length of 17 inches, and the whole camera, with ground glass and double holder, weighs only 4 pounds. If a Triplex Tripod and five extra double Jiolders are ordered with this camera, we supply a carrying case fitted to contain them all, with compartments for lenses, etc,, without charge for case. ' I ^HIS is the lightest, most compact and easily adjustable, reversible JL back camera in the market. It is of highly polished mahogany, the metal work having the draw file finish, like that used on the finest mathematical instruments. It is provided with our patent adjustable spring actuated ground glass, always in position and never in the way. The front portion of the bed is provided with hinges, so as to drop or to fold under the camera when in use with wide angle lenses of short focus. It is made rigid by use of our patent clamp hooks, and is provided with against the admission of light into the holder. The Normandie is fitted with the Zephyr double dry plate holder up to 8 x 10 inclusive ; above that size, with the Eclipse holder. Where extra holders are required, either the Eclipse or Zephyr may be ordered. This camera can be had with either the single or double swing. The price below quoted includes one double holder, and our telescopic brass bound Canvas Carrying Case. IT has long been our desire to place before the public a camera that would at once embrace these most necessary requirements — portability, compactness, and strength, combined with beauty and accuracy of with a long, continuous metallic rack, cog wheel and pinion, the latter being firmly held in position by a binding screw. The ground glass springs backward in its frame, like that in the regular Novelette Camera, and is held tightly in position by metallic spring corners. When Naturally those without stereoscopic attachments are still lighter and a trifle more compact than those with, and may be preferred by persons who desire to make single portraits or views only. When six holders are purchased at once with the camera, the extra five holders are put in a leather case with sling, gratis. CONSISTING of an 8 x 10 bellows and ground glass, with a 5 x S camera, and an n x 14 bellows and ground glass, with an 8 x 10 camera, making two cameras in one. This most ingenious method converts a camera of smaller size into a larger one by the simple adjustment of the back and bellows, which are made to fit the same bed and front board ; each part is provided with separate carrying case and double holder and makes when attached to the bed, a. perfect camera of either size as desired. found interchangeable. The camera is reversed in same way as our Novelette and Fairy Camera, by the keyhole slots and screw heads. The front is raised or lowered on the metal standards, but when closing the camera, the top of the front should be fastened on a level with the top of the standards. The camera is always closed with the plate horizontally, and hence is always ready for viewing without reversing. THESE carrying cases are, as indicated by the cut, extremely neat and tasteful in appearance, and are made of the best material, and ir* the most thorough manner. We now supply these cases with all For View, Portrait and Copying Work. THIS instrument is a most useful camera for view and portrait photography and enlargements combined. It consists of a regular 8xio Novelette Camera, made however with an extra long bellows and arranged with an extension to the bed which gives it a focal length of 32^ inches. As shown in the cut, the bellows is fitted with a movable support, which serves to hold it in position and prevent sagging when in use for enlargements. The extra bed is held firmly in position by means of dowels and our patent clamp hooks, and may be attached or detached almost instantly. This camera is furnished with carrying case, and its entire weight is only 7 pounds. Price, including one of our new style double Novelette holders and carrying case, $40.00. Cameras. THE form of construction of this new camera is made apparent by the illustration here shown. The experienced copyist will not need any such simple directions for use as we append. An important feature in this camera, that is found in no other, is, that the center-board with lens, can be used in the end of the camera, converting it at once into an extra long copying camera. This will be found very advantageous in enlarging small pictures by one operation. DIRECTIONS FOR USE. To copy a negative in the natural size, place it in the kit on the front of the camera and button it in. Attached to the center frame of the camera is a division upon which, on the side toward the camera front- a lens is mounted. Suppose this to be a quarter-plate portrait lens, the focal length of which we will suppose to be 4 inches : draw back the center frame and the lens twice the focal length of the lens (8 inches) ; slide the back frame with ground glass the same distance from the center frame. To enlarge with the same lens to eight times the size of the original, the center of the lens must be 4^ inches from the negative, and the ground glass be 36 inches from the center of the lens. To reduce in the same proportion, reverse, and have 36 inches from the center of the lens to the negative, and from the center of lens to ground glass 40 inches. It is assumed that the photographer knows exactly what the focus of his lens is, and that he is able to measure accurately from its optical center. The use of the table will be seen from the following illustration : A photographer has a carte to enlarge to four times its size, and the lens he intends employing is of six inches equivalent focus. He must, therefore, look for 4 on the upper horizontal line, and for 6 in the first vertical column, and carry his eye to where these two join, which will be at 30 — 7)^. The greater of these is the distance the sensitive plate must be from the center of the lens, and the lesser, the distance of the picture to be copied. To reduce a picture any given number of times the same method must be followed, but in this case the greater number will represent the distance between the lens and the picture to be copied ; the lesser, that between the lens and the sensitive plate. This explanation will be sufficient for every case of enlargement or reduction. If the focus of the lens be 12 inches, as this number is not in the column of focal lengths, look out for 6 in this column and multiply by 2, and so on with any other numbers. The Leather Covered Detective Camera. THIS CAMERA is focused for objects at various measured distances, and the points are marked upon the index shown in the cut at the side of the box, the pointer of the index serving to act upon gear work to bring the camera in adjustment for any given distance. After this the ground glass may be entirely dispensed with, as it is then only necessary to estimate the distance of the object to be photographed and move the focusing lever to the mark corresponding to that distance, when the camera will obviously be in focus. The small lens in the upper left hand corner serves to throw the picture on a piece of ground glass on the top of the camera, thus showing the position of the image on the plate. When the picture appears in proper position on this ground glass, it is only necessary to touch the button on the right of the camera and the exposure of the plate is instantly made, its development being afterward accomplished in the ordinary manner. 4x5, . . . . 6o.oo 4i x 6-J, . . . . 90.00 3i x 4^ and 4x5, covered with leather, . Fitted with Dallmeyer Rapid Rectilinear Lens, prices are : Patented Nov. n, 1884. Sep. 14, 1886. March 22, 1887. March 29, 1887. THE above cut shows one of our latest Detective Cameras, which is kept in stock in one size only, 4x5, larger sizes being made to order. It is so arranged that its working parts are all on the left side of the box, and is so constructed that the shutter may be set, released, and its speed regulated, from the outside, without having to open the box at all. Lenses of varying focal length may be used and the diaphragms changed without removing the shutter. A removable rear compartment is also made for use with the camera, which is fitted to contain five double holders and which is adapted to take the place of the focusing cloth when the plate holders and rear partitions have been removed, an advantage not possessed by any other style of detective camera. This Camera may be carried and operated in our patent satchel, thus giving it the appearance of an ordinary hand bag. IN outward appearance, and to the ordinary observer, this latest modification of the Detective Camera looks exactly like an alligator hand-satchel that is carried by a shoulder-strap at the side of the pedestrian. Upon closer observation, one sees that it consists of an artfullyconcealed detective camera, in which all the various movements to secure a picture are situated upon the under side. For use, the camera is held so that the base of the satchel rests against the body of the operator. By means of a brass pull at the side the shutter is set. A plate in the regular holder is placed in position at the back of the camera, and the slide is drawn ready for exposure. The release of a short catch, exposes the front of the shutter ready for action, and by raising a small leather-covered lid the little camera obscura, called the finder, on the (now) upper side of the camera, shows the position that the object will occupy on the plate. The slightest touch upon a small brass button releases the shutter, and the exposure is made. Replacing the slide in the plate holder, reversing the holder, and setting the shutter again, leaves the apparatus in readiness for another shot, when the plate holder slide is withdrawn as before. By releasing a spring bolt on the under side of the case, the camera proper can be removed from its cover, and a tripod screw serves to attach the camera to a tripod for ordinary use. packed away that no light can strike them. It is also furnished with an ingenious attachment by which the speed of the shutter can be regulated to suit the speed of the object, moving with greater or less velocity ; while, by simply releasing a catch, time exposures can be made at the will of the operator. In fact the whole affair is an important achievement in ingenious, compact and light photographic apparatus. . R 40.03 S 56.00 T 78.00 In Imitation Alligator or Grained Leather, with Removable Rear Compartment containg five extra Patent Double Dry Plate Holders (six in all), . U 50.00 V 66.00 W 88.00 In Genuine Alligator, with Removable Rear Compartment containing five extra Patent Double Dry Plate Holders (six in all) X 55.00 Y 71.00 Z 93.00 the least possible effort or loss of time, patience or temper. The box is adapted to the making of 4 x 5 pictures, either timeor instantaneous, which may be taken either vertically or horizontally, and is provided with a finder which may be used for either position. Three patent double holders are supplied with each camera, one being our regular Zephyr double holder for Dry Plates and the other two being our new patent double holders for Films, in which the popular Climax or other celluloid Cut Films may be used. This camera is fitted with a fine combination instantaneous achromatic landscape lens and a shutter of an entirely new design, which by its peculiar mechanism is always closed, except at the moment of exposure, the resetting being accomplished by a very simple but ingenious patented device, which requires only the movement of a lever to the right or left, as the case may be. The manipulation of the shutter is wholly from the outside of the box, and it may be made to work with greater or less rapidity as desired. The mechanism of the entire instrument is most simple and effective. A new and valuable feature is the rear compartment of the camera, the cover of which may be removed, when there will be found a ground glass which is also removable, and which renders the camera perfectly suitable for ordinary portrait or landscape photqgraphy, where time exposures are required. A tripod screw and cap for lens, which also accompany the P. D. Q., complete its equipment for such work, and the entire camera is neatly covered in black grained leather. Zephyr holders may also be fitted with our patent metal film kits. Price, including camera, lens, shutter and three patent double holders, $20.00. The same, in polished walnut, only §15.00. Directions for use accompany each camera. IS a neat and handsome detective camera ror pictures 2^/2 x 2^ inches. It is fitted with six double dry plate holders and twelve kits for films. It is provided with finder, and is covered in black grained leather. It may be used for time exposure as well as instantaneous, and occupies only a space of 4 x 5^ x 6^ inches. refilling the holders or opening the camera. AS shown by the cut, this camera has the appearance of a neat i6mo volume bound in black leather, and only upon the closest inspection would it be suspected that it was anything else. The size of the book is 2^ x 4^2 x 6^ and it may be carried in the hand or in a neat and tasty leather case, slung over the shoulder like a pair of field glasses. It may be operated without removal from the case and is so arranged, that no part of the camera need be opened till the whole or any portion of the 2Jj. plates are exposed. The lens attached to this camera is made expressly for it by one of the best opticians in Europe, and is achromatic and will be found to give correct perspective, with great sharpness. The camera is supplied with 2Jk plate holders for plates if6 inches square, which are carried in a magazine and which may be exposed in succession and deposited in a second magazine in the order of their exposure, by simply pulling out and pushing back a metal rod. IS an entirely new magazine camera, in which twelve or twenty-four exposures may be made without drawing a slide or inserting a plate holder, and twelve or twenty-four new plates or films may then be inserted and exposed without going into a dark room. It is adapted to 4 x 5 size, either vertical or horizontal, and is so arranged that the plates or films stored in the camera are exposed one at a time, as desired, and then by the simple pressure of a spring, each plate, after exposure, is dropped into a reservoir at bottom of the camera, where it may remain until the whole are exposed or be removed earlier for development, as desired. The plates may be changed and the camera refilled in broad daylight, the process being simplicity itself. Accompanying the camera is a magazine which is filled in the dark room, and which holds, like the camera, either 12 plates or 24 films. When it is desired to refill the camera, this magazine is fitted on the back of camera in the same way that a ground glass is attached to an ordinary box, and by drawing two dark slides, one from the camera and the other from the magazine, the entire lot of fresh plates are deposited in position to be exposed in rotation ; the slide is then returned to back of camera and the empty magazine detached, after which it is secured at the bottom of the camera and slide drawn therefrom, when the exposed plates will drop into the magazine. The slides are now both replaced and the magazine, full of exposed plates, detached. The size of this camera is only 105 x 7^ x 6^-, while the magazine measures only 6^ x 6 x 2\. It is fitted, as above stated, to carry either glass or films, or both, the turning of two metal catches adapting it to the different thicknesses of either, and owing to this difference in thickness 24 films may be carried, as against 12 glass plates. This camera is covered in black leather, with black metal trimmings, and is unsurpassed for neatness of appearance. It is provided with a double achromatic lens, and has the advantage that it may be focused from the outside, by movement of a lever on the side of the box, it is provided with a finder which is adjustable for horizontal or upright views, and has a shutter, simple of construction but thoroughly practicable, which may be used for either time or instantaneous exposures. Lilliput Camera. I HIS is the handiest, lightest and most easily handled detective camera ever put upon the market. In outward appearance it resembles a small hand bag, being made of fine sole leather and fitted with a sling strap for convenience in carrying. It occupies a space only 4x4x6 inches, and notwithstanding its small bulk, carries six double holders, which may be filled with glass plates or films and which are emptied and refilled by the operator himself precisely as if in a regular camera. The lens covers an angle of about 60°, and is adjusted to universal focus, being therefore always in readiness for use. The ^•p HIS MINUTE CAMERA is made to be suspended J_ from the neck of the operator and worn under both coat and vest with the lens protruding through the buttonhole of the vest. It is made of metal, nickel plated, 'and is provided with circular plate for six exposures without changing. The camera is 6 inches in diameter, 24 inch in thickness, and weighs only y<z Ib. The lens is of universal focus and concealment almost perfect. Plate Holders or Shields. THESE are the most compact plate holders in the market, the rabbet commonly found on the plate holder being dispensed with and placed on the camera instead, thus saving the additional weight of twelve such rabbets when made on the plate holder (two on each of the six holders usually carried), and the item of three-fourths of an inch in bulk. be found to be smaller than any other double dry plate holders made. The construction of our patent perfect double holders is such that several sizes of plates can be used without the aid of inside kits, for instance, in a 5 x 8 holder, any plate measuring five inches one way and not over eight inches the other, can be used, 4x5, 5x7, etc. This is very convenient where experiments regarding time are being made, and narrow strips being tried, in place of using an entire plate, or different sizes of plate with inside dry plate kits. Thin wooden frames can be supplied for holding still smaller sizes, if desired, so that the amateur can experiment with plates smaller than the extreme limit of his holders, and at much less expense. (See Inside Dry Plate Kits.) They are also much more readily managed in the ruby light than any other style. The Novelette and Eclipse Holders are of the same dimensions and style, except that the former have pins in the edges by which they are held fast to the camera by hooks, whereas the Eclipse Holders are used with cameras having springs in place of hooks. Holders. THESE are unquestionably the lightest and most convenient holders of their size in the market. The plates are placed in and removed from the holder at one of the ends, which is opened by pressing aside the metal band that secures the wooden cover. (See right hand cut.) These holders have hard rubber slides, and are provided with an ingenious device for holding slides in place and preventing their being accidentally drawn out when the holder contains plates. These holders are used with our Detective, 4x5 Novelette, Bicycle and Bijou Cameras. They are also supplied with our Manhattan No. i and O. N. A. No. i B equipments. They are made in the following sizes only: ARE similar to the Detective Holders, but with paper slide. They can be used with any of our Amateur Outfits, a ad when fitted with pins at the sides, can be attached to our Novelette Camera. our Climax Negative Films, and for compactness, lightness and practicability are unequaled. They are made in the same style as our Patent Novelette Holders for glass plates ; but, being adapted to the use of the Climax Films, are consequently very much lighter than they could be made to carry a heavier plate. ARE constructed to be filled and plates removed from the front, on withdrawal of slide in dark room, and the plates are held firmly in position, when the slide is drawn in the camera, by the spring and two grooved shoulders at ends of the holder. An ingenious safety latch is attached to this holder, which renders it impossible to draw more than one slide at a time, thus preventing many accidents. These holders fit all view cameras of our manufacture that have our patent spring actuated ground glass. Our regular dry plate kits can be used in this holder, which is as light as the lightest weight holder made. THE Universal Film Carrier will carry Films perfectly flat ; fit any holder now made ; and by means of a movable end, easily adjust any unevenness of edge, and is perfect for the use intended. be readily pushed in place. Third. — Extend the other end of carrier by pulling out the slide. Use same means as in adjusting at other end, when the slide can be closed. There is no necessity of the fingers touching the Film in placing in carrier. THIN WOODEN FRAMES to hold small sized plates, fitting in any ordinary plate holder, thus enabling the amateur who has a large camera, to use small plates as well as large ones. Dry Plates. AS the manufacture of dry plates has advanced and the many plate makers have come to more uniform manipulations in the working of the process, the plates produced have gradually been improving in all the qualities essential to good results, until it has become no easy matter to select anyone make as pre-eminently the best for any and all kinds of work, and the operator is at liberty to make his own selection from the successful brands which are recognized by all as being reliable, or to experiment for himself in new directions. We supply at manufacturers' regular list prices, all regular brands such as Stanley, Carbutt, Cramer. Seed, Harvard, Phenix, Eagle, etc., as follows: F'OR PORTRAITS, landscapes and drop shutter work. Weight and space reduced to a minimum. 14 doz. films weigh less than i doz. glass plates. They are developed in the same manner as dry plates. They reduce halation and can be printed from either side of film. Anthony's Climax Negative Films are made upon a substance of recent discovery which is admirably adapted to the manufacture of a perfect negative film, combining transparency, strength and toughness of composition, which renders them capable of being made so thin as almost to eliminate the question of weight and bulk in carrying. They are made with a fine mat surface which reduces halation, and are perfectly impervious to water. Can be sent by mail without danger of breakage. For Portraits, Landscapes, Interiors and Instantaneous Views. XT O extra processes are necessary. But Films are exposed, developed, JL\I fixed, washed, dried, and printed from, the same as Dry Plates ; and being but -^\-§ of an inch in thickness, can be printed from either side. These Flexible Films are not made on sheet gelatine, or of paper made translucent, but on a transparent material perfectly impervious to water, unbreakable, and with a fine matt surface that renders them especially desirable for Interior Views and Landscapes, as halation is thereby greatly reduced. They can be used in regular plate-holders for Studio or Landscape work, or in the special film-holders now supplied by the several manufacturers of photographic apparatus. ARE the most sensitive orthochromatic plates known, and are superior to all other orthochromatic or color-sensitive plates, from the fact that their sensitiveness for yellow rays, as proven by spectrum, is about three times as great as that of ordinary cosine plates already in the market. Therefore these plates require no yellow screen in landscape work. They give the different scales of green foliage, the clouds, the distance, in spite of fog, far better than an ordinary plate, and have the same sensitiveness as the plain emulsion they are made from, while other ordinary orthochromatic plates are generally less sensitive than ordinary emulsion plates. They are, therefore, suitable also for instantaneous work, and will be found invaluable in portrait work, for yellow colored faces, colored costumes, etc. The Climax Tripod. AS shown by the cut, this tripod folds in three joints, making it much more convenient to carry than the ordinary two jointed folding tripod. It resembles the Triplex Tripod in length, but is not telescopic. The legs may be left permanently in the top when folded, and the other ends being fastened by a strap, a leather handle on one of the legs forms a convenient method of carrying it. Tripod. THIS is the finest finished in the market and perfectly rigid, combining both the folding and telescopic, besides which it occupies little space, and for transportation can be packed with clothing in a large grip sack. It is made of cherry throughout, and has the patent springs on under side of top, by which it is impossible for the legs to become unfastened accidentally. When the leg is fully extended, it is held automatically by a spring, saving necessity of using thumb screw for clamping same. up ready for use. OUR aim has long been to make all apparatus connected with outdoor photography as light and compact as is consistent with strength and durability. Until now the tripod has successfully resisted all efforts in that direction. But at last we can offer to our customers a tripod which is a marvel of lightness, compactness and rigidity, and which can be readily carried in an ordinary hand bag. When folded it is only 16 inches long and weighs but i Ib. 15 oz. WE give a sectional view of our Clamp Tripod Top, which dispenses entirely with the tripod screw, and by means of which the camera is instantly clamped to the tripod. This attachment entirely does away with the annoying delays and difficulties of the old method and is a most essential part of a complete photographic equipment. The Umbrella Tripod Is, as shown by the cuts, an ingeniously arranged tripod which, when not in use, folds to resemble very closely an umbrella. Rapid Universal Lenses. THESE lenses are of the rectilinear, compound type, and are intended for studio and general outdoor photography. Every lens is supplied with morocco cap and case and eight stops. Alvan G. Clark Lenses. lenses are of such quality and capacity that they mark an A epoch in the construction of photographic objectives. They are the invention of Alvan G. Clark, the celebrated manufacturer of telescopes, and are of a construction dissimilar from anything heretofore followed, and are as striking in their results as Mr. Clark's success in the telescope objectives has been. These lenses may be used with equal facility in three directions : 1. To all work to which the rapid rectilinear type may be adapted, when they give an angle of about 60 degrees, and in which capacity we enumerate them under List No. i. under List No. 2. 3. When the)' may be used as wide angle objectives, having an aperture of nearly 100 degrees, and as such they may be used with larger stop than any other specially constructed wide angle lenses. They are quite free from marginal distortion and magnified perspective, so common to lenses of this class. As wide angle lenses they are quoted under List No. 3. When using these lenses in this capacity, care should be used in beveling the back of the front board, so as to allow free passage of the rays. The lenses are uncemented, each lens of the combination being mounted for itself, and are therefore free from danger of gradual decrease in speed, so common in many lenses, owing to the chemical change in the cement. The crown glass is on the outside, and therefore less liable to become scratched. The mountings are unusually compact, and each mounting has engraved upon it Mr. Clark's autograph as well as our firm name. While these lenses are intended to be used in all outdoor work, they are also particularly suited to copying, enlarging and photo-engraving work, and are superb for portraiture, particularly for groups, covering the plates for which they are rated, noticeably better than any others. Their characteristic qualities in almost every direction are of so high an order that we have no hesitation in claiming that they are superior to anv lens yet produced. FOR ordinary landscape work these lenses give very brilliant effects, fully covering the plates specified. They are the best lenses in the market at the price. All have rotating diaphragms, so that the time of exposure may be varied to suit the subject. E. A. View Lenses. THESE are single combination lenses, used for landscape work only, but cover the plate very sharply. They have diaphragms in the front of the tube, and rack and pinion movement. THIS LENS being of short focus and of wide angle, and made on the rectilinear principle, is a useful one for architectural photography, and is not equaled at the price by any in market. Those who do not care to invest in the best — the Dallmeyer — will find this an excellent substitute. E. A. Portrait Lenses. With Rack and Pinion. THE attention of those who wish to procure a good portrait lens, but do not desire so expensive an instrument as that made by J. H. Dallmeyer, is respectfully invited to the following, which will be found good and uniform, as well as the best for the price. By removing the back combination, and screwing the front combination in its place, an excellent landscape lens is secured. E. A. Instantaneous Stereo. Lenses. FOR instantaneous outdoor views, for indoor stereo, groups, C. de V., etc., etc. These are portrait combinations, and so constructed that the back lenses can be removed and the front ones screwed in their places, thus making a pair of single combination landscape lenses. They are in matched pairs, have Waterhouse diaphragms in leather cases, and rack and pinion movement. The Platyscope Lens IS another of the Rectilinear series of Aplanatic lenses and while more moderate in price than the Dallmeyer or Aristoscope, gives most excellent results. Besides giving the equivalent focus and measure of plate they will cover with full opening, we also state the IOO.OO The Platyscope lenses are now fitted with IRIS diaphragm in place of the central stops, the desired opening being obtained by merely turning the ring on body of tube, which shows exact measure of opening. In these there are no loose diaphragms to get lost. Long Focus Platyscope. WE have also some Platyscopes of longer foci, for use on distant objects, yachts, steamers, etc., where one desires them to be larger on the negative than when lenses of shorter foci are used. This makes possible the photographing of many things which would otherwise be impossible, as for instance, views which from their distance would be too small to be of use. This lens in fact is exactly the reverse of a very short focus wide angle lens, and is as valuable in its way for special work as is the wide angle in its peculiar field. at a moderate price. They are unequalled at the price for instantaneous views, portraits, landscapes, architectural subjects, dimly lighted interiors, copying, etc., etc. We urge those who intend purchasing a lens for such work to try the Aristoscope before deciding. We guarantee them to be unexcelled by any lens except the Dallmeyer. Sizes, prices, etc., as follows: Wide Angle Aristoscope Lenses. THIS LENS is fast becoming a favorite and where a really first-class instrument is required at a moderate price, cannot be excelled. It has great depth of focus, sharp and brilliant definition, and is rectilinear in its results. We would urge its trial and feel confident that if tested, its superiority will be made apparent. THE extraordinary unanimity of opinion regarding the excellence of Mr. Dallmeyer's lenses both in Europe and America, is one of the most gratifying evidences of their great superiority. There is not a photographer of any note on either side of the Atlantic who is not the possessor of one or more — some can count them by the dozen — and the difference in cost between these and the inferior ones is very slight, when their great superiority is considered. None others approach them, and they have long been justly held to be the most indispensable of all the requisites of the art. In the quality of the glass used; in the perfection of finish and adjustment ; in softness, crispness and depth ; in rapidity, delicacy and every quality a lens should possess, the Dallmeyer lenses are unrivaled. With or without diaphragms, they are better adapted to the particular work in hand than any others ever made, and every kind of photographic requirement is provided for. Before purchasing, carefully read the information contained in the catalogue, particularly that regarding the series of rapid rectilinear and the wide angle rectilinear. The first requirement in making photographs of great merit, whether for portraiture, landscapes, architectural views, or copying, is a lens that in skilled hands promises the very best results. Those who excel uniformly select Dallmeyer lenses and pronounce them indispensable. The PATENT PORTRAIT combinations have an adjustment of the back lens by which a diffusion of focus or depth of definition is obtained. This is not found in any other make. They also have a full set of the Waterhouse diaphragms in morocco cases. HESE LENSES embrace angles of pictures from 90 to 100 deg., and enable photographers to take views of buildings, interiors, etc., in confined situations, where lenses of longer focus cannot be used, and where absolute rectitude of lines is imperative. The wide-angle rectilinear lens has the following advantages over existing non-distorting double combination lenses : It is entirely free from a central spot. It can be used with a larger stop, /'. c., it is quicker in action. It produces a more brilliant picture. The lenses of which it is composed are smaller and thinner, for a given sized plate, than those of other lenses intended for the same size of picture. The lenses are mounted in rigid settings or tubes, and each is furnished with a rotating diaphragm plate. In the column below, the largest size of plate covered by each lens is recorded ; and if microscopic definition up to the corners be required the smallest or smallest but one stop should be used. THE RAPID RECTILINEAR LENS is emphatically "The Lens" for all kinds of outdoor photography. It works at an intensity of £, and, although not so rapid as the D Lens, requiring nearly double the exposure, is superior to it for views because of its having only four, instead of six, reflecting surfaces. It is composed of two exactly symmetrical cemented combinations, and unlike most existing double combination cemented lenses, requiring small stops to cure the inherent excessive spherical aberration, the Rapid Rectilinear is aplanatic, /. <?., it works with the full opening. Hence its superiority for all kinds of quick outdoor pictures, groups, instantaneous effects, landscapes, architectural subjects, or for dimlylighted interiors. For copying and enlarging this lens is unrivalled. With smaller stops each lens covers the next larger, or even two sizes larger plates than those recorded, thus embracing angles of pictures from sixty to eighty degrees and this without any trace of flare or central spot. Many fine large portrait studies have been taken with this lens, and it is to be found in the possession of almost every photographer of eminence wherever the art is practiced. Either combination can be used singly as an ordinary landscape lens ; focus, about twice that of the compound lens. for the next size larger view. N. B. — It is recommended that all rapid rectilinear lenses above the 10x12 size should always be focused with a medium stop (No. 3), whether the picture is to be afterwards taken with a larger or smaller stop. Each lens is constructed to give the greatest possible " depth of focus " which involves the above conditions. THIS is a single combination landscape lens specially constructed for obtaining large images in distant views, mountain scenery, balloon photography, etc. Each lens is supplied with a set of Waterhouse diaphragms, the apertures of the stops of these lenses being too large to admit of their arrangement in the form of a rotating diaphragm as supplied with the "wide angle" landscape series. It has a working intensity somewhat more than -fa (or about twice as quick as the wide angle landscape lens), and in this condition is entirely free from outstanding spherical aberration, /. e.f gives a perfectly denned image. THIS is a single combination landscape lens, working at an intensity of -fa, and is the best lens for landscapes, pure and simple, embracing large angles. Being a single combination, like the rapid landscape, it has but two reflecting surfaces and therefore produces a more brilliant picture than the wide-angle multiple lenses. It works with a proportionally large stop, i. e., it is quicker in action and the illumination is more equally distributed from the center to the margin of the plate. Being composed of three lenses cemented together it is superior to the old Meniscus, composed of two, inasmuch as it produces less distortion, gives better marginal definition and is of much smaller size. THIS LENS works at an intensity, with the first stop, of -fa, and is therefore somewhat slower in action than the rapid landscape, requiring an exposure of about % longer and, similarly to those lenses, may be used with a larger aperture than the first stop. It is particularly constructed for views, architectural subjects, copying, etc., where it is essential that straight lines should be accurately portrayed, and has been constructed specially to meet this long-felt want in the form of a single combination. HANDY and compact ; serving the double purpose of a convenient drinking cup and a perfect focusing glass. A telescopic metallic cup. with a fine lens adjusted to the bottom, and packed in a neat metal case with screw cover. Every tourist photographer should have one. Price, . $0.75 The Photoscript IS an ingenious apparatus, by means of which the operator may title and number his negatives in plain type, with little or no trouble, directly on the film surface. The letters and numbers so produced, are clean cut and white, and may be put in any corner or margin desired. Price $6.00 Photometer for Timing Exposures. THIS instrument consists of a black cloth covered tube, in one end of which is an aperture, into which slides a graduated scale, through which the light is allowed to pass vie the tube, which is placed on the ground glass in the same way that a focusing glass would be used. Showing method of fastening Finder to Camera. Showing Finder on Camera. THIS is a neat, compact article that can instantly be attached to any camera, and is of great value in composing a view. The object to be photographed being plainly visible and occupying the same relative position as on the ground glass or plate, it is indispensable for instantaneous views of moving objects. It corresponds in shape to the ordinary negative. The ground side of the glass can be marked at will to denote position desired when taking instantaneous views. THE shutter is attached to the lens tube by means of a metal collar, that is provided with a binding screw to hold it firmly in place. The shutter consists of a wooden casing, with facing of hard rubber, inside of which is a hard rubber slide, having an aperture corresponding in size to the aperture in the casing. This slide runs very easily in the grooves in wooden casing, and admits of a very rapid exposure when the shutter is set at full speed. The shutter is set by turning (towards the right] the milled screw at the left hand side of back. The speed can be regulated at will by drawing out or pushing in the brass pull, seen in the cut, at lower left hand side of shutter, a binding screw at the left serving to hold this pull at any desired distance, thus perfectly regulating the speed. For time exposures the shutter should be set at slow speed, and the little brass piece on top of shutter at the left hand side (see cut), so adjusted as to allow the long arm of the trigger to reach down as far as it will go, thereby engaging with the lower pin on the slide at the moment ONE of the neatest, simplest and most practicable drop shutters ever made. It is adapted to either time or instantaneous movement by simply turning a small metal button, and the working of the shutter for either is simply perfect. The tension being obtained by the use of a rubber band, it may be set at great speed, or may be worked by gravity alone, if desired. For time exposure, turn the catch upward to the right. The hood should be removed from the lens when possible in using this shutter, and care should be taken to have the collar of shutter closely fitted to lens to exclude light. larger or smaller, so that if is adjustable to any ordinary lens. By a very simple and ingenious device, this shutter is changed from long time exposure to the most rapid instantaneous working, all that is needed to effect the change being the adjustment of a metal catch. It is provided with Pneumatic Release which works either time or instantaneous movement, and for the former is unlike most other shutters in use, inasmuch as the bulb must be compressed for opening the shutter and again compressed for closing it ; a metal catch dropping and holding it open until released by the second pressure of bulb, whether for long or short time. The shutter responds instantly to the compression of the bulb, thus giving the operator perfect control of his exposure. It is compact, light and simple in construction, easily worked and of fine appearance, and each shutter is neatly packed in a small mahogany case, which will readily fit into the pocket. A Perfect Time and Instantaneous Shutter. THIS SHUTTER is now so well known that an extended description here is hardly required. When shutter is received by purchaser, he transfers the glasses from his regular lens tube to correctly adapted tubes on the shutter, which are also arranged to receive regular diaphragms. Rotary diaphragms are added to shutter when ordered. «xtra prices as for rotary stops, by which Silent time and very slow to quite rapid instantaneous exposures can be made without having to reset the shutter for each exposure. Opening in shutter should be about the size of next to largest diaphragm. Shutters can be furnished complete for most standard lenses, but it is to customer's interest to forward his lens tube to ensure a perfect fit, which is THE Triplex shutter gives facility of three methods of exposure r Quick instantaneous, time, slow instantaneous. Time and slow instantaneous are effected in manner similar to >ilent time, slow instantaneous to Duplex shutter. Its simplicity of construction and operation, and its mechanism being on front in sight, recommend it. It has met with much favor since its introduction in Summer of 1889. It is easily adapted for use in detective boxes, to be released by either, or both, push trip or pneumatic. It is also made in stereoscopic form. The makers of this shutter assert that practical comparison with any other will demonstrate its unquestioned superiority. When no particular size shutter is specified in order, lenses as a rule are adapted to shutter having opening less than the largest diapraghm of lens. Thus, a 6£ x 8^ lens is adapted to a No. i shutter. Rotary stops include five openings, largest corresponding with opening in shutter, four others such as are thought best. Requests for special sizes are, however, complied with when possible. Rotary stops, up to size No. r, price, $1.50 ; over that size, up to No. 2A, 82.00 extra, but not furnished above 2\. 50 cents extra. Shutters can be furnished for most standard lenses, fitted ready for use, bui it is to the customer's interest to forward his lens tube, otherwise perfect fit is not guaranteed. FOR INSTANTANEOUS OR TIME EXPOSURES. THIS shutter is made of metal, with hard rubber face and disks. The latter are propelled by levers connecting them with the revolving plate, this plate being actuated by means of a lever and cord. This shutter, though expensive, is one of the most perfect ever made. To Operate the Shutter. — For instantaneous work, push the lever, A, to the right (as shown in the cut). Revolve the nut, C, until the aperture is full, when the focus can be obtained. Revolve it further until it catches, and pull out the slide, D, as far as it will go ; then press the bulb and the operation is effected. For time exposures, push in the slide, U, to slacken the speed, push the lever, A, to the left, press the bulb and release the pressure. The shutter will remain open until the bulb is again pressed, when it closes instantly. Diaphragm Shutter. THE advantages of the principles involved in the Diaphragm Shutter are so apparent that they have from the outset been fully appreciated. It requires little argument to show that the proper place for opening and closing a Shutter is in the optical axis of the Lens, and in both time and instantaneous photography, it is evident that this Shutter, starting its opening with a pin hole and gradually increasing to the size of stop for which it is set, and returning in the same manner, will give the effect of a small stop, /. e., more depth and flatness. The makers have taken advantage of all the improvements, and offer the Model '90 with the confidence that it meets every condition. While the Shutter is in itself a nice piece of mechanism, the workmanship and finish are of the highest order. There are no loose stops. The variation in size of stop is made by turning the black disk, which is supplied with a large index. Absolute control of time exposure. Large index giving correct indication of time, in seconds and fractions thereof. Entire independence of speed regulation from the influence of temperature or humidity. By turning a lever it is set for either time or instantaneous exposure, and remains so until changed. The movement during exposure is almost absolutely free from concussion. The blades are changed from steel to hard rubber, so that there is no danger from rust. All parts which must be manipulated are placed at the front, easy of access. We guarantee that the Shutters and barrels are absolutely true and optically centered, whether arranged for our Lenses or others. While we have sample barrels of almost all known Lenses, we find that there is a variation in the thread of almost all makes. We will therefore assume no responsibility in fitting the same, and recommend that the Lenses or Lens tubes be sent to us to be fitted. THE Low " Kazoo " Shutter No. i is a handsomely finished nickel plated shutter. Can be instantly changed from time to instantaneous exposure, by simply moving the small lever to one side. Gives the correct exposure, and requires no resetting after either time or instantaneous movement, as it sets itself after every exposure without opening the wings. This shutter is provided with an adjustable spring back that will fit any size of lens tube. THIS Low " Kazoo " No. 2 is designed to be placed on the inside of camera and attached to the front board. It can be operated entirely from the outside of the camera and at any distance away. To change from time to instantaneous exposures, it is only necessary to push in or pull out a small brass pin, which passes through the front board and into the shutter. It will balance open for any length of time while focusing. The " Kazoo " gives the correct exposure, lighting the drapery or foreground most. Low View Shutter, No. 10. THE Low Shutter No. 10 is simply constructed and is a very practical shutter. It is nicely finished with Japan front, with brass trimmings, and cherry finished back. There are now many hundred of them in use which are giving universal satisfaction and splendid results. They can be readily changed from time to instantaneous exposures, by moving the brass lever to one side. E Low Shutter No. 6 is a very simple, well made, and nicely finished shutter, having the special advantage of a very large opening in a small shutter. Works lightly and easily, and gives the correct exposure. For cameras having small front-boards the Low Shutter No. 6 is especially adapted. The small sizes are admirably adapted for time view wont. To change from time to instantaneous exposures it is only necessary to push in, or pull out, a small bra:-s pin, which passes through the front board into the shutter. Above shows it as in use with artificial light. THE CUTS give an admirably clear idea of the Universal Lantern, and at a glance any one" acquainted with the mechanism of projecting lanterns will see its advantages. With only a passing reference to the camera and front, the use of which is obvious, your attention is called to the apparatus for illumination, which is by all odds the most important feature of any enlarging lantern. The lamp, which is intended for use with kerosene, is provided with a double-wick burner, both flames emerging through a single aperture in the dome. This feature increases the volume of light two-fold ; the burner is provided with a close-fitting chimney-base fitted with an aperture covered with non-actinic glass, intended both for dark room illumination and also for observing the height of the flames. A conical light conductor connects the lamp with the condensing lenses, and is made to telescope so as to adjust the light accurately to the focus of the condensers ; this light conductor has an aperture at the side covered with a movable metallic disk, and is intended to admit of the operator finding the centering point of his flame on the condensers ; this he will see at a glance by the reflector. The lamp is not rigid, but can be revolved so as to bring the flame in any desired position. Some negatives require a more intense light than others, and experience will show how to arrange the light for any particular occasion. The form of this lantern is such that all heat passes upwards through the chimney, and as there is no boxing around the apparatus it is always cool, and all risk of breaking lenses or negatives is avoided. The change from the use of artificial light to daylight is better shown in the cut than described in writing. With this lantern and a half-inch stop in a half-size portrait lens, life-sized enlargements from cabinet negatives may be easily made with Anthony's Reliable Bromide Paper in from thirty-five seconds to one minute, according to density of negative. Cooper Lantern as transformed into a Daylight Enlarging Camera, The design of this lantern is the result of long practical experience with various methods of illumination for enlarging, and we can guarantee its giving results as perfect as the electric light at a cost that makes comparison ridiculous. This lantern is also admirably suited for slide projection, and is therefore of double value to societies and colleges. landscapes. This lantern may be transformed into an 8 x 10 portrait or copying camera by the addition of an adapter, double dry plate holder, and ground glass, at an extra expense of $10. FOR DAYLIGHT ENLARGING. — Remove the lamp and condensers, rack the front inward as far as it will come, then raise the back of the bellowsbearing frame from its position to the back of the bed-board on which it will be securely held by the screw heads which fit into the key-hole slots corresponding. Remove the front in the same way and set it back on the screws designed for it, which will be found on the movable bed operated by the rack work. Attach the ground-glass frame to the back and the instrument is ready for use. A dark room with an aperture in the window allowing the ground glass end to fit firmly so as to exclude all outside light, but allowing an unobstructed view of the sky, is the most satisfactory. If you cannot get a clear view of the sky use a mirror at a proper angle to reflect the sky above. White card-board reflectors may be used, but nothing equals the mirror. A shelf should be fastened to the window to support the weight of the camera. USED AS A COPYING OR PORTRAIT CAMERA. — Besides the double use for artificial or daylight work, this camera may be fitted with an attachment by which it can be quickly and easily adapted to the purposes of in their place a regular camera back is buttoned on. This is provided with a double dry plate holder, 8x 10, which is slid into position under the ground glass, as shown in the cut. For ordinary work up to 8 x 10 in the gallery this is as good as any camera made. For the Cooper Lantern. THE ABOVE CUT represents the attachments which may be used with the Cooper Lantern for the exhibition of slides of views or scientific subjects, and makes the apparatus complete and specially suited to the use of schools, colleges and societies. Consists of frame, 6 carriers and box. struction, economy, and practical usefulness. It is intended for making enlargements on gelatino-bromide rapid printing paper by artificial light, requiring only from thirty to sixty seconds' exposure for a life-size head. Another purpose for which it admirably serves is that of a dark-room lantern. It is provided with non-actinic glass panels in the sides of the lantern. It can also be used as a copying camera for making lantern transparencies. WE have seen many lanterns in our time, but in several respects this eclipses them all, and especially those for use with kerosene oil only. The lamp itself is completely shielded with a well made hood of Russia iron, and is provided with the patent triplex wick, which affords the utmost illumination obtainable with any oil light. The latter enables one to always observe the condition of the flame and wicks, and regulate them without disturbing or discontinuing the action of the instrument. The chimney is made telescopic to pack more closely. The diffusing lens, specially constructed for the purpose, is mounted on a cylindrical slide, to extend, if necessary, the focal distance, while the condensing lenses, which are of four-inch diameter and can be separated for cleaning, are inserted in a corresponding slide within the wooden case. The case itself is quite compact, and appears very ornamental in its highly polished mahogany, with its little hinged ventilators on either side at the bottom. The metal front is burnished, and has a spiral spring adapter for the admission of the slides. A substantial wooden box contains all, and serves also as a table for the instrument while in Altogether, this is the finest example of its kind we have yet seen. It will also serve admirably for enlargements with the gelatino-bromide paper. It is destined to become very popular. Price, $35.00. The Tisdell Candle Ruby Light. THE accompanying cut represents the Tisdell Candle Ruby Light for developing the most sensitive gelatine dry plates. One-half of a common sperm candle is the fuel required, consequently there is No possibility of smoke. The lamp is always ready for use and has nothing to get out of order. Its manipulation is extremely simple. A single glance at the lamp while open is sufficient to explain the method of its use to a perfect stranger. It \ without exception the most perfect and petite construction in the shape of a ruby developing lamp ever introduced in the photographic market. Its outside measurement when packed for transportation is only 6^ x 2^ inches, and its weight only twelve ounces. Oil Lamp with Ruby Chimney. THE accompanying cut represents an oil lamp for use in developing gelatinobromide plates. It is expressly made for the purpose, and is intended for use with kerosene oil. The chimney is of ruby colored glass of the proper and most desirable tint, and surmounted with a movable top to intercept the upward radiation of the light of the lamp. HAS separable parts, and all are easily and quickly adjusted. There are no hinges to become dislocated nor arm holes to wear out. It is easily lighted and extinguished ; it requires but little care to keep clean ; it can never get out of order ; it takes but little oil, and it affords a good light. Open for use. Closed. THE FRAMEWORK about this candle is covered with both orange and ruby fabric, the combination making a safe and efficient light for the dark room and one which is agreeable to the eyes. It has no glass to break. faces and reflector. The glass is of the correct non-actinic hue. It is perfectly safe, and by all odds the most comfortable kerosene lantern to work by yet seen. For Attachment to any Ordinary Gas Bracket. BY the annexed cut it will be seen that the patent argand burner has been so modified as to intercept the downward radiation of the light of the lamp ; protection above is provided in the same manner as with the oil lamp. The chimneys of both gas and oil lamps, it should be particularly remembered, are not made erf the ordinary ruby glass, but what is known in the trade as copper-flashed. Extra ruby chimneys, 30 cents each. These burners are also manufactured on metal stands with a connection for rubber hose, by which they may be used at any distance from the gas bracket Price of stand extra, 50 cents. restful to the eyes. Price, including nonactinic amber chimney, extra brass tip and box of chemical wicks in wooden box complete, $3.50. Extra chemical wicks sufficient for one thousand hours' lighting, per box, 35c. Extra nonactinic amber chimneys, each, 3oc. Lantern arranged for making positives by contact. THE following are some of the advantages possessed by this Lantern : It saves your eyesight. It is simple and easy to manager is not complicated, yet has three separate and distinct forms of light, It is adapted for the use of either oil or gas ; is about nine inches square by fourteen high, with eight by ten ruby glass in front. Each lantern is provided with a coal-oil lamp, with improved patent burner and silvered reflector, which may be revolved in any direction and operated from the outside. By removing the revolving lamp bed, a hole will be found through which a gas burner can be introduced. It can be used for seven or more different operations in photography, several of which have never been combined in any one lantern, to wit : First. — A safe light for the preparation of gelatino-bromide emulsion, Second. — A safe light for the coating of gelatino-bromide plates. flooded with white light and as quickly changed to the red, giving abundance of light by which to develop the largest sized plates used. The adjustable hood effectually shields the eyes from the glare of the red light, a matter of the greatest importance to those having a large number of negatives to develop, or other work to perform necessitating red light. Fourth. — An opal light by which to examine negatives or positives after fixing, enabling the operator to judge of their quality, thereby avoiding the necessity of leaving the dark room in search of white light. Fifth. — A clear transparent light for making positives on glass (gelatino-bromide). This feature is a valuable one ; any photographer can materially add to his revenue by making these most beautiful products. placed in front of opal light. Seventh. — The making of photo-micrographs with the clear, transparent light, which can readily be accomplished with the gelatinobromide plate and the microscope. Eighth. — By the adjustment of condensers and holder for slides and objective in front of the clear light, a very effective magic lantern is foimed. Price, $6, boxed ready for shipment. Economy Rubber Tray. AS will be seen by the cut, the glass negative lies flat on the bottom of the tray, necessitating the least possible quantity of developer, and the depressed channel in bottom of tray is sufficiently deep to allow the finger or plate-lifter to engage firmly underneath the plate and remove it without risk of scratching. They are of polished hard rubber. Papier Mache Trays. A RECENT importation of our own, of superior quality, and at reduced 2~\. prices. These goods are very durable, light in weight and deep. They are black in color, and in general appearance not unlike the hard rubber tray. THESE TRAYS, being made of porcelain, of a dark brown color^ are very durable, and owing to their non-actinic property, are considered by many to be far superior to the ordinary white porcelain ware for developing purposes. r I ^HIS neat article can be readily attached to the door of any printing _L frame, and has two dials, one of which shows how many prints are to be made from the negative, and as each one is removed, it is recorded on the other dial. By this means the count can always be kept correctly. They are all nickel plated, and the cut shows the exact size. Price, per dozen, 750. Improved Printing Frames. OUR PRINTING FRAMES are now provided, in all sizes, with the new tally without addition to price. As will be seen from the cut, the numerical wheel is revolved, being held firmly in position by a spring. These printing frames are made of cherry, with superior brass springs, constructed on the most scientific principles. The springs are riveted to the backs and a brass washer is placed under the spring to prevent abrasion of the wood in turning it. /'"'COMBINING strength, rigidity and lightness, and so constructed V^ that the springs lock into the eyes, or catches on the sides, rendering it impossible for them to slip from position. They are handsomely finished, and much lighter and more compact than any other style. market. For use, it is simply poured into the tray, and when development is finished, may be filtered and returned to the bottle. This can be re peated many times. It yields a negative of fine printing color, and with out fog. Full directions accompany each bottle. Dr. H. W. Vogel, of Germany, writes in the highest terms of Hydrokinone as a developer, praising particularly its advantages for negatives of widely differing relative exposures. THIS NEW DEVELOPER, introduced by Prof. Henry J. Newton, is unlike any similar agent, inasmuch as it works from the first, until all used up, with full vigor and does not slow up after developing a few plates as most developers are apt to do. shadows and a splendid, quick printing color. It is admirably adapted to general work, yielding the most brilliant negatives, transparencies, or bromide prints. Perfect freedom from stain with rapidity of action, and a very strong tendency to do what is most desired of a developer, /. e., continue its action until the development is completed, combine to make it just what is required for the photographer, either professional or amateur. THIS DEVELOPER is put up in a highly concentrated form, keeps well, and will perform nearly twice the work of any similar developer. Being in one solution, its management is easily understood by the beginner, who is often " all at sea " with developers put up in separate solutions. It stands unrivaled as a dry-plate developer, and is extremely quick in action. It can be used with any brand of plates, giving beautifully soft negatives. To those who are desirous of avoiding the trouble of preparing their own developers it will commend itself on the very first trial ; and that it will figure as a valuable item in the travelers' photographic outfit, goes without saying. All who have used this developer thus far express themselves as delighted with it. With this solution underexposed plates will bear prolonged and forced development without showing the least tendency to become veiled or hazed in the shadows, as is so common with most developers. THIS DEVELOPER is from another formula put up in concentrated form, which also produces beautiful negatives and allows very considerable latitude of exposure ; it never becomes muddy and can be used repeatedly with fine effect, over-exposed plates producing better results if developed in old developer than new. It is sold ready mixed and only needs to be diluted with water. IN PACKAGE containing 16 ounces Concentrated Developer, in 8-ounce bottles, one having the pyrogallic solution, the other the alkali, thus enabling the operator to proportion them as desired. The contents of each bottle are in highly concentrated form and require merely the addition of water to reduce to normal strength. For Dry Plates and Films. THIS Developer possess every good quality that can be desired. It is very effective and yields negatives of great brilliancy, combined witn softness, bringing out the finest details. Being in concentrated form, it merely requires the addition of water and Bro. Potass. In this diluted form, it can be used several times before being exhausted. It will not stain the negatives, and any degree of intensity can be produced. It is equally good for instantaneous or time exposures. Full directions accompany each bottle. IS manufactured from the most powerful developing agent known, and its results are of a beautiful bluish black color, which renders it easy to judge of the quality of the negative. By its use, the time of exposure may be made considerably less than with any developer now in use, and the resultant negative will be found to be full of detail, with the high lights crisp and brilliant. It is prepared in solution ready for use, and its keeping qualities are excellent. It may be used several times over, and for all but very much under exposed plates, old developer is better than new. Acid Sulphite of Soda. IS especially adapted to use in the fixing bath, rendering it acid and very considerably reducing the time required for fixing ; it also gives exceptionally clear and stainless negatives. Acid Sulphite may also be used as a preservative of pyro, hydroquinone or eikonogen in developers, but not in those developers which contain all the ingredients in one bottle. Where used in this way it entirely replaces the use of ordinary sulphite of soda in the two solution developer. Something New and Practicable. FOR convenience in the compounding of developers, we have prepared the following chemicals in the form of tablets, each tablet containing a specified number of grains. We believe that they will be found very valuable, particularly among amateurs, who, by their use, will be enabled to dispense entirely with the troublesome method of weighing for each formula. We put them on the market with confidence that they will fill a long felt want. FOR convenience in toning silver prints these tablets will be found unequaled. One tablet dissolved in 7 oz. water and combined with TT oz. of ordinary gold solution makes a toning bath which will produce beautiful prints and save the operator much time in preparation. SAVE TIME and hence money. The solution is made ready in a few moments, and can be used by anyone. Try them and you will continue to use them. They are put up in To USE. — Dissolve one of the packages of toning powder in 7 ounces of lukewarm water, and add i ounce of the gold solution. As the prints exhaust the solution add more of the gold and powder. With Ground Stopple Bottle and Graduated Tumbler for Chemical Solutions. THESE CQNTRIVANCES are a great convenience to either amateur or professional photographers who wish to carry solutions of developer, etc., in their travels without possibility of breakage or leakage. The cases are drawn from solid metal and made of even thickness throughout, being corrugated for the purpose of giving them strength to resist crushing or indentation, as they are very light. This corrugation answers the purpose of a male and female screw, whereby the top of the case is screwed down until it rests on the glass stopple of the bottle and thus keeps it tightly in its place and prevents the bottle from rattling about in the case. The cut shows the case as it appears when open, indicating the style and position of the graduated tumbler which is furnished with the three last sizes. No. 4A. Diameter, 2i in.; length, 7 in.; weight, 14 oz., furnished with 8 oz. bottle, with tumbler, making J pint flask, each, i.io No. I3A. Diameter, 2; in.; length, 6 in.; weight, 17 oz., furnished with S oz. bottle, with tumbler, making \ pint flask, each, 1.20 For Oxalate Developer. THIS DEVELOPING BOTTLE is a great convenience to the amateur or professional photographer. It is provided with a rubber tube by which the developer is drawn from the bottom of the bottle as required. A thin layer of oil on the surface prevents chemical action from contact with the air. It will soon save its cost in the quantity of developer economized. Warranted Accurate. /COMPLAINT is frequently made of the V^ ordinary glass graduate that it is not accurate, and sometimes one marked 16 oz. will show a variation of i oz. either way. The Anthony Molded Graduate, however, can be depended on every time to be thoroughly accurate in its markings and to hold full measure as indicated by scale marked on each. They are all manufactured at the same place and by skillful workmen, and are guaranteed. glass funnels ever made. They are very strong ; are made in molds ; have solid glass ribs on the inside, running vertically as shown in cut, thus forming passages through which the solution descends freely after passing through the paper, and accomplishing the filtration in a fraction of the time heretofore required. Another advantage of this funnel is that the outside of the neck is fluted and the lower end beveled, so as to prevent choking up in the neck of the bottle, and overflowing. IN this combination of funnel and filter the bulb retains the filtering cotton in such a manner as to obviate the difficulty experienced in the ordinary funnel from the cotton being compressed too tightly. A glance at the cut will readily explain its advantages. Pints, each, . . soc. \| Quarts, . . 6ac. \| Half gallon, . . §1.00 The latest and cheapest serviceable Photo Clip in the market. THIS CLIP is exceedingly strong, being made of hard wood, with heavy wire springs, and is provided with a hook. The quality of stock employed in its construction is of the best, and the price lower than for any other article of its kind. than any other adjustable clip in market. The change from long to short clip is effected in an instant, and there is nothing about it to break or get out of order. The cut represents the exact size. r I ^HESE are the most desirable articles of their class to be found in _L the market, being substantially made in the best manner, and the fact that they never break or give way in any particular must recommend them to all. The springs are made of first quality brass wire, and the wood is very hard and durable. They are made in two sizes and various styles, as follows, the cut showing the exact size of the large clip: Full Gross. Cents. THIS PAPER is unequaled by any other in the market for quickness of printing, for bringing out the finer details of a negative, and for brilliancy and depth of tone. It may be finished with either a flat or glace surface and may be toned in several shades of color. Its keeping qualities are excellent and the results obtained with it are unsurpassed. The toning and fixing may be done in a combined bath thus necessitating but one operation. Paper. THIS PAPER was expressly manufactured for and introduced by us to give to those who have not the skill, time, inclination or appliances to sensitize photographic paper preparatory to printing, an article of the finest quality and of uniform sensitiveness. Requires neither Toning nor Sunlight. THIS PAPER being prepared with the same substance as used on the gelatine dry plates, requires no other chemicals for its development than the ferrous oxalate developer employed in the development of the negative, which is a great convenience in traveling. It must consequently always be used in a room free from actinic light. It yields the strongest blacks, with a fullness of detail that is quite surprising. It is made in a quick emulsion for use with artificial light ; and also in a slow, for use with daylight. It can be had either quick or slow, in Light Smooth (L. S.), Heavy Smooth (H. S.), or Heavy Grained (H. G.), as may be desired. Use it once and you will have no other. This paper was formerly made in two grades : quick, for use with artificial light, and slow, for use with daylight ; but instead of these we now make a Medium Grade, which works equally well with either artificial light or daylight. Pizzighelli Direct Printing Paper. THIS is a new production which requires neither developing nor toning and gives a beautiful print, with deep rich black tones of color, at a minimum of labor. After printing, the paper is soaked for a few moments in dilute muriatic acid and washed in two or three changes of water and the result is absolutely permanent. This paper is extremely simple in its manipulation, and therefore very convenient for making proofs from negatives. It is also adapted for the reproduction of mottoes, plans, drawings, manuscript, circulars, and to show representations of scenery, boats, machinery, etc., for an engraver to copy from. The rapidity with which a print can be made with this paper is, for numerous purposes, and to men in some occupations, a very great recommendation in its favor. BY its use, paper can be silvered, regardless of the weather, and kept two weeks, or longer, white and in perfect working condition. IS a new form of direct printing paper, manufactured under the formula of Captain Pizzighelli, which is susceptible of extremely rich, soft, black tones. By the use of this paper, either under or over exposed prints may be intensified by redevelopment and beautiful results obtained. The fact that this paper is manufactured by us, and in this country, makes it possible for us to keep it freshly made and enables us to guarantee its quality, which is not possible with foreign goods. Developing Outfits for Making Negatives. THESE OUTFITS contain everything necessary for developing one dozen negatives, including trays, graduates, funnels, etc., that will last for years, and sufficient chemicals for making several dozen additional negatives. 4x5 Developing Outfit. — Tisdell Lamp ; i dozen dry plates ; 2 developing trays ; Stanley's Concentrated Developer ; hyposulphite of soda; bromide potass.; alum; i funnel; 3 glass graduates; focusing cloth ; scales and weights ; developing fork ; bottle of negative varnish. Price, $5.25. Printing Outfits. OUTFITS include everything necessary for making and J_ mounting two dozen prints from the negatives, and chemicals sufficient for several dozen more. 4x5 Printing Outfit. — 4 dozen 4x5 sensitized albumen paper ; blue litmus paper; chloride gold (A); bicarbonate of soda (B); chloride of sodium (D); i pound hyposulphite soda; i printing frame, 4x551 4x5 papier mache developing tray ; one 2 oz. graduate 515x7 porcelain tray (deep); i jar of paste; i hard rubber set and bound paste brush ; i glass pattern, 4x5; i straight trimmer ; 24 sheets 6^ x 8£ card-board. Price, $4.75. Dispensing Scales and Weights. THESE are made for weighing small quantities only — grains, scruples and drams. With French weights they are equally useful for weighing grams, etc. Price, in wooden box, with a set of apothecaries' weights, 75 cts. Patent Pocket Pyro Scales. '" I ^HESE scales are made with a view to being carried in the pocket JL and occupy, when closed, a space only 2\ x i£ inches. They have no weights to lose, are neat, handy and extremely useful, their capacity is from \ to 20 grains. Price, complete, $1.00. No Weights. Quickly Adjusted. THIS, \ve believe, will fill a long felt want. It has a Q-inch nickelplated beam, neatly mounted on a japanned iron standard. The front end of the beam weighs from one to thirty grains, the other end weighing from one-half to eight drams, or one ounce, and is very accurate. The pan is movable and has no side bar to interfere. We guarantee them in every respect. Price, $5.00 ornament and a very convenient method of showing specimen pictures in the studio. This admits of the photos being burnished, which cannot be done with the ordinary amateur album. They are sold in sets of two gangs. Price per set, 50 cents. Dry Plate Safety Box. IN outward appearance resembling an ordinary negative box, though not so deep ; but within, instead of grooves, it has a close fitting cover lined with black velvet, so as to guard the plates against any possible reflections. Thus plates of any size up to 8 x 10 may be removed from the original packages, that should always be opened in the dark room, and safely kept in this box until transferred to the plate holder. Negative Preservers. THESE goods consist of a heavy manilla envelope, very carefully made, with flat seams and having blanks printed for registering number, subject and description of negative enclosed. They are unexcelled for convenience and safety in packing negatives away and finding them when wanted. In packages of 25, packed 500 in a box. Prices as follows : THE ANTHONY SELF-CHANGING SHOWER WASHING BOX for dry plate negatives is a nicely constructed and convenient apparatus. Made substantially of zinc inside and out, it has interior grooves in which either 5x8 or 8xio negatives may be placed. When the negatives are introduced, the hose is attached to a faucet, the lid is now closed and locked if desired, and the water turned on. It will be seen that the water enters the washer from above, and that the inside of the lid is made in the form of a perforated fountain, which discharges a spray over the plates When the negatives are entirely submerged, the water is all drawn off by means of a selfacting siphon, and the process of showering is repeated. With this apparatus the hypo can be thoroughly eliminated from the gelatine film in from fifteen minutes to half an hour. The change of water is continuous. Price, $5. practicable arrangement for washing negatives, and consists of an outer box of heavy metal, provided with a tube at bottom, for attachment of rubber hose, which distributes the water through perforated pipes running lengthwise of the box, the perforations of which are on the inside of pipe and at such an angle to each other as to ccuse the streams of water to cross each other in an upward direction in the middle of the box, which results in a constant upward current to the overflow pipe, thus insuring a perfect elimination of free chemical agents from the negatives. negatives in an upright position within the box. These Negative Washers are made in three sizes only, but may be used for any size of plate smaller than the one named, without adjustment. 5x8 . $4.50 \| 6ix8J . $5.00 \| 8xio . $5.50 Rubber hose and coupling for same, $1.50 extra. A convenient and compact washing rack for negatives which, when not in use, may be folded together to occupy extremely small space. It is made of metal and is kept open by a metal button locking into a slot. Adjustable Negative Washing Rack. THIS Negative Rack is made entirely of metal and is fastened at the joints with rivets which allow it to be opened or closed, to take any sized negative desired, the joints are held in place after being opened to the proper size, by set screws at either end. Price, each, AS seen by the cut, this is for holding the dry plate during developing and washing. It entirely prevents soiling of hands, and by its aid the plate is easily examined and returned to solution, saving necessity of ridges and elevations on bottom of tray to prevent capillary attraction. They are made in two sizes, nickel plated. plates. It not only protects the hands, but serves also to raise the plate from the tray when desired. The rocker is adapted to the sizes of trays mostly used by professional and amateur. It is also useful in toning and fixing prints, the motion keeping the solution in constant agitation. Price, each, $1.50 Size No. 2 is for any plates having a 5 inch measurement. Size No. 3 is for any plates having a 6J/2 inch measurement. Size No. 4 is for any plates having an 8 inch measurement. Larger sizes made to order. Price, 250. each. Patent Transparency Frames. THESE are made with one side removable, enabling the transparency to slide into the frame easily and without danger of breaking. They are also made to hang either vertically or horizontally. Frames. THESE FRAMES are handsomely embossed in a heavy leaf pattern and present a very rich and beautiful appearance. They are so arranged with a loop at each of the four corners that they may be used either vertically or horizontally. Plain Nickel. THESE by many are preferred to the regular styles, on account of the ease in fitting glasses of different thicknesses. All are made with ring in each corner, to hang either vertically or horizontally, as represented in cut illustrative of the Antique Silver. Etched Ground Glass for Transparencies. THESE GLASSES are etched with handsomely figured borders and the 8x 10 and lox 12 sizes may be had in either of two or three designs. The other sizes are only supplied in one pattern. THESE BRUSHES, though somewhat more expensive than the ordinary make, are well worth the difference in price, being absolutely the best thing of the kind ever made. The bristles are secured by first immersing the butts (or stiff ends) of the bristles in soft rubber ; they are then put upon the end of the handle (not around it as in the old way); a belt of rubber combined with metal is wound around the whole, covering the butt of the bristles, and conforming to a groove running around the adjoining end of the handle. The portion of the brush covered with rubber and metal is then placed in a die and vulcanized (or hardened) under heat and pressure. The result is a solid vulcanized head, in which the bristles are so thoroughly imbedded that it is impossible for them to get loose. The handle being dovetailed into the head (see sectional illustration), is also firmly secured. It is self-evident that this method of constructing brushes is far superior to the old modes. These brushes are not affected in any manner by any solution in which they may be used, and they can be kept for any length of time in either damp or dry atmosphere without injury. THIS is a most convenient adjunct to an enlarging outfit, as it is so made as to fold into very small compass when not in use and to be firm and practicable in every way. It is made in two sizes, 32 x 42 and 42 x 64, and is easily taken apart for stowing away or transportation. Prices, $9.00 and $10.00, respectively. FOR preserving prints from negatives of one's own work, these Albums form a handsome and interesting addition to the library table. They are very beautifully bound in cloth, with gilt stamp on side, the corners being finished with leather. The purest quality of card-board is used in their manufacture, made expressly for mounting photographs and free from any chemicals injurious to prints. The Climax Removable Leaf Album. THIS album is unequaled for convenience, strength, durability and gentility of appearance. Its greitest advantage lies in the fact that its leaves are entirely independent of the book itself and of each other, and one or all may be removed from the covers, and the whole or a part replaced or new leaves substituted with perfect ease. The covers and heavy fly leaves front and back, constitute the binding, the latter being very strongly made with linen guards, which are provided with four holes and lacings ; the cards are provided with a jointed linen guard which is punctured to match lace holes in fly leaves, and the whole operation of lacing one or more leaves in this way is simplicity itself. By using this album, prints may be remounted on either or both sides of card, and may also be burnished without injury to the album, which is alone a most important feature. The guards being made with a patent double flexible joint, admit of the album being opened in a perfectly flat position without difficulty, and the ease of binding makes possible a classification and rearrangement of subjects from time to time. THE ECLIPSE ALBUM, with interchangeable leaves, is one of the most perfect manufactured. Each card mount is distinctly independent, and may be taken out or replaced without having to disturb any other leaf or part of album. They are handsomely finished in morocco, half leather bound, with gilt title, and enclosed in a neat box. Extra cards for Eclipse Album may be had if desired. advantages are : An adjustable knife carriage having an easy and accurate action, with shearing cut. A table rest for material being cut. An accurate scale for obtaining uniformity in size. An absolute ^ right-angle gauge for squaring struction making it impossible for knife to run off, slip or tear prints, etc. The old method of trimming prints by means of a "former" glassr and tintypes by use of shears, is far from satisfactory, as most photographers will testify, being slow and frequently resulting in utter destruction of the material. All these annoyances and difficulties are obviated by using this cutter. In architectural work the straight line side is cut first, which is then placed against the gauge, and print squared as desired. The machine is set complete upon a solid base, from which it can be detached and fastened to table as desired. All who have examined it and tested it speak very highly in its praise, owing to its general usefulness and cheapness. Daisy Permanent Starch Paste. r I ^ HERE has been for a long time a demand J- for a starch paste that would neither mold, sour or discolor, yet put up in a convenient form ready for use. We now introduce such an article, under the name of the Daisy Permanent Starch Paste. fiABrvooo ECONOMICAL. No moisture on rolls. It can be heated in a few minutes. Perfect combustion. Heat gauged by thermometer, and held at one point by turning wick up or down. prize at the Pittsburgh Exhibition in 1888. Recognizing the danger attending the use of the various Explosive Compounds heretofore used for illuminating, Mr. Pine has succeeded, after much experimenting, in inventing a Lamp for burning Pure Magnesium, and takes pride in offering one which, for brilliancy, rapidity and simplicity, has been pronounced by professional photographers, who have tested it, to be the most complete Flash Lamp in the market. Its peculiar construction insures perfect combustion, and as magnesium is non-explosive, absolute safety is assured. the latest improvements of the original inventor of this system of magnesium lighting. It consists of three essential parts, namely : a large flat alcohol lamp, a receptacle for magnesium holding about sixty grains, and a large hand pressure bulb, all compactly joined together, but separable for convenience in carrying. The apparatus when properly charged will give, with a single pressure on the bulb, an intense and brilliant light sufficient to fully expose from fifteen to twenty feet. By repeated pressures, large, interiors may be photographed with wide angle lenses. The apparatus is held in and operated by the same hand, and requires no other support, and the light may be projected in any direction, and at any angle of elevation. The Reeves Magnesium Flash Lamp. T~) EFERENCE to the cut shows its simplicity and easy method of _Lv using. The rimmed back, 7 x 9^2 inches in size, holds horizontally two wicks, the pan below has other wicks or pads of cotton wool, surrounding the bowl of an ingeniously shaped brass blow pipe, to which is attached rubber tube and bulb. To use it, the pipe is charged with powdered metallic magnesium, a small quantity of alcohol poured on the wicks, which, when lighted, give a very large flame (the width of the back and several inches higher), pressure on the bulb fires the magnesium through the blaze, the result being a flash of tremendous size and actinic power. Then the back, which is hinged, is shut down, at once extinguishing the blazing alcohol. There is no smoke, and there being no reservoir for alcohol, there is absolutely no danger of explosion. The bowl of the blow-pipe is so designed that it spreads the magnesium in a fan-like shape through all parts of the flame, using only about twelve grains of powder. Inside the hinged back are hooks to fasten the wicks, also a false back with curved bottom to convey the superfluous alcohol from upper wicks into lower pan. The back has spring to set it at any angle ; there is a guard or fender to blow-pipe to prevent it over-heating, and cover for same. The whole is well and strongly made throughout of Russia iron, neatly mounted on metal-covered board, packed in box. I HIS IGNITER may be used for either Compound Flash Powders, Magnesium Cartridges or pure Magnesium Powder on a substratum of Flash Cotton. It is safe, reliable and simple in construction, consisting of a carbon heat arranged under a receptacle for the cotton and magnesium, the latter being fired by pressure of rubber bulb which forces the flame upward. Price, including box of scented carbons, rubber bulb and 3 feet of rubber tubing, complete in wooden box, $4.00. Extra boxes of prepared and scented carbons, enough for over 100 exposures, 25 cts. Extra rubber tubing in lengths up to 50 feet, 5 cents per foot. amount of smoke given off is insignificant, exposure succeeding exposure without hindrance therefrom. The full charge is 15 grains (at the utmost 20 grains) of pure magnesium, a few grains, however (3 to 5), being sufficient for simple portraiture. Full directions accompany each lamp. For instantaneous photography at night. THE remarkable results obtained by using Photogenic Cartridges, fired from a pistol, have induced us to place them upon the market. Each cartridge will give sufficient light for an ordinary exposure or small group. They contain no chlorate of potash and can be handled without danger. furnished with the various kinds of lamp. This Magnesium Powder, being entirely free from explosive compounds, will not ignite by application of fire only, but is suitable only for use with a flash lamp or with our flash cotton specially prepared for the purpose. For use with Cotton — Directions : Sprinkle 15 grains or a teaspoon filled to water level of the powder, lightly and evenly over one or two layers of the flash cotton which has previously been picked out, into a flaky condition, free from lumps and bunches ; taking care that the ing through it. When ready to expose plate, ignite the cotton with match or taper, keeping well away from the flame which is very hot ; for this reason it should be prepared and ignited on a metal plate or piece of asbestos board. Interiors. THIS POWDER is unexcelled for its actinic power and absolute safety. It is entirely free from chlorate of potass — it cannot explode, either by friction or concussion, but can only be ignited by actual contact with flame. It is especially useful in copying with orthochromatic plates, objects in which color values are particularly important. Oil paintings and rich interior decorations photographed by this light, in conjunction with orthochromatic plates, will give results of extraordinary fidelity. Elastic Felt Printing Pads. FOR USE IN THE PRINTING FRAME, they insure contact of the negative and paper and lessen the liability of breakage. They are superior to anything heretofore offered, and at following moderate prices. They are put up in boxes of one dozen each. HIS PLATE LIFTER is very nearly like an ordinary open-end thimble with a pointed piece of metal soldered securely to it, as shown in the illustration. Where a number of plates are developed in one dish, this plate lifter is not only convenience, but quite a necessity. Price, 15 cents each. For insxiring the exclusion of air and obtaining perfect contact of prints with hard rubber plates or prepared glass, in the process of making glace prints with bromide paper, aristotype paper, etc., etc. THE MOST compact and simple for recording exposures, and containing perforated sheet numbers for 288 negatives, with pages for recording number of holder, progressive number, date, subject, time, lens, focus, diaphragm, time of day, plate, and general remarks. Neatly and strongly bound, measuring 3x4^ inches. Varnish for Gelatine Dry Plate Negatives. IN CONSEQUENCE of the peculiarity exhibited by gelatine negatives, it seems to be desirable that any varnish used upon them should be as hard and as insoluble as possible. We have consequently prepared and are now ready to furnish a proper varnish at the same rate as our other negative varnishes. It is very clear, does not impart any color to the negative, and will not soften in the heat of the sun. The trouble in varnishing gelatine negatives arises from the fact that the gelatine film is very apt to absorb or retain moisture. It should therefore be well heated, to drive off all moisture before the varnish is applied. It should then be allowed to cool off to the temperature proper for varnishing. As the film is liable to retain within it the solvent of the varnish, it should be allowed to cool after the varnishing, and then, before being used in printing, it should be well heated again to drive off any of the alcohol that may be retained in the film. All our negative varnishes, viz., the flint, the special, the retouching, and Mountfort's, can be used perfectly well with the precautions above noted, and it is better, even with the new dry plate varnish, to proceed in the same manner. No. 25. DICTIONARY OF PHOTOGRAPHY for the Amateur and Professional, by E. J. Wall, containing concise and explanatory articles. Illustrated by many specially prepared diagrams. Printed on heavy coated wood cut paper. Handsomely bound in cloth. Price in cloth, 240 pp., $1.50. No. 26. THE CHEMISTRY OF PHOTOGRAPHY. By Raphael Meldola, F. R. S., Professor of Chemistry in the Technical College, Finsbury ; City and Guilds of London Institute for the Advancement of Technical Education. Crown 8vo, $2.00. No. 27. THE INTERNATIONAL ANNUAL of Anthony's Photographic Bulletin for 1889-90, by W. Jerome Harrison, F. G. S., Birmingham, England ; and Arthur H. Elliott. Ph. D., F. C. S. A Summer Annual of Photography. Illustrated. Paper, 50 cents; cloth, $1.00. No. 28. THE INTERNATIONAL ANNUAL OF ANTHONY'S PHOTOGRAPHIC BULLETIN. Vol. III. for 1890-91. Edited by VV. Jerome Harrison, F. G. S., Birmingham, England ; and Arthur H. Elliott, Ph. D.. F. C. S., New York. Contains 186 articles, 480 pages of reading matter, and 22 full-page photographic or photo-mechanical process prints. These prints alone are worth the price of the book. Paper, 75 cents; cloth, handsomely bound, with cut stamped in gold on side, $1.25. No. 29. PLATINUM TONING (including directions for the production of the Sensitive Paper). By Lyonel Clark, C. E. A very thorough and practical work on the subject of Platinum Printing in all its phases, and one which will be read with interest and profit by all workers in photography. 96 pp., in paper covers, 50 cents. No. 30. CAMERAS, LENSES, SHUTTERS, ETC. Consisting of Competitive Papers on Photography, contributed by prominent English writers. This work covers a wide field, and is full of practical information, hints and suggestions. 118 pp. Price, in paper covers, 50 cents. No. 31. EXPERIMENTAL PHOTOGRAPHY. By C. J. Leaper, F. C. S. A very complete compendium of information for the amateur. Treating of every branch of photography in a clear and lucid manner. 102 pp., paper covers, 50 cents. No. 32. ART PHOTOGRAPHY IN SHORT CHAPTERS. By H. P. Robinson. A very useful and interesting work on composition, lighting and kindred subjects. With illustrations. 60 pp., in paper, 50 cents. Amateur Photographers. By Max Bfilte. Price, in paper, 50 cents. ANTHONY'S PHO.OGRAPHIC BULLETIN. Edited by Prof. Charles F. Chandler, Ph. D., LL.D., of the School of Mines, Columbia College, New York City, and Prof. Arthur H. Elliott, Ph.D., F.C.S., Professor of Chemistry and Physics, College of Pharmacy, City of New York. 32 pp., octavo, semi-monthly. The most popular photographic journal in America. Illustrated. $3.00 per annum in advance. WILSON'S PHOTOGRAPHICS. " Chautauqua Edition." With appendix. By Edward L. Wilson, Ph.D. Covers every department. 352 pp. Finely illustrated. $4.00. BURNET'S ESSAYS ON ART. A facsimile reproduction of the costly original edition. Will help every portrait maker, every view taker, who will study them understandingly. They teach the rudiments and the rules of art entire. You cannot appreciate or understand the enjoyment there is in pictures, and in making them out or indoors, until you have read " Burnet's Essays" and studied the 145 etchings which illustrate them. $4.00. PHOTO-ENGRAVING, PHOTO-ETCHING AND PHOTO-LITHOGRAPHY. By W. T. Wilkinson. Revised and enlarged by Edward L. Wilson, Ph.D. Illustrated. 180 pp., all new. Only American edition. Cloth bound, $3.00. 25 cents. DRY PLATE PHOTOGRAPHY ; or, the tannin process. By John Towler, M.D. 50 cents. THE CARBON INSTRUCTOR. By G Wharton Simpson, M.A. 25 cents. CRAYON PORTRAITURE IN BLACK AND WHITE. By J. B. Crocker. 35 cents. THE PORCELAIN PICTURE ; or, how to make photographs on porcelain or opal glass. By Photographic News, London. Edited by Thomas Bolas. Weekly. $5.00 per annum. British Journal of Photography. Edited by J. Traill Taylor. Weekly. $5.00 per annum. British Journal Photographic Almanac and the Year Book of Photography. Genuine English edition. 50 cents each. FACSIMILE OF A RARE CATALOG After studying the daguerreotype process under Samuel F. B. Morse in his spare time, Edward Anthony became a professional photographer around 1 842. He left the practice of dagucrreotypy to become a dealer in daguerreotype materials in New York about 1 847. Though initially an importer of photographic materials, he soon came to manufacture his own goods, eventually producing all the materials necessary for the practice of the art. In 1852 Edward entered into partnership with his brother Henry, the firm name being changed to E. & H. T. Anthony & Co. in 1862. During the Civil War the Anthonys contributed to the documenting of the conflict by publishing many cartes-de-visite and stcreograms of Mathew Brady. The name of the firm remained unchanged until a 1901 merger with the Scoville & Adams Co. to form the Anthony & Scovill Co. which reorganized as the Ansco Co. in 1907. Following a merger with the Agfa interests in 1928 and receivership in World War II, because of its German connections, the company eventually became GAP of the present day. This 1891 catalogue was issued during a period of transition in photographic equipment. The successful production of gelatin dry plates in the early 1 880's brought a tremendous increase in the popularity of photography with amateurs. The introduction by Anthony of the Schmid Patent Detective Camera initiated the development of the "hand camera" in America and started the "detective camera" craze, which by 1891 was still going strong. This catalogue gives an idea of the types of equipment in use by amateurs in 1891, the still-popular folding-bed cameras and the increasingly-popular hand cameras. In fact, the only type of apparatus notably not present was Eastman's roll-film cameras, which were then sold directly by Eastman. The catalogue shows the lengths to which photographers went to conceal cameras by placing them in satchels or books or under a vest. It serves as a source of identification of equipment and illustrates the variety of apparatus necessary for the complete photographic process. The clarity of the line illustrations adds a feeling of the times hardly obtainable through today's photographic illustrations. This catalogue is a "must" for anyone interested in the technology, art, or practice of photography in the late 1 9th century.	26,528	common-pile/pre_1929_books_filtered	illustratedcatal00ehtaiala	public_library	public_library_1929_dolma-0022.json.gz:992	https://archive.org/download/illustratedcatal00ehtaiala/illustratedcatal00ehtaiala_djvu.txt
KvH_PNwzHccnpS8r	The Tegucigalpa coinage of 1823, by Howland Wood.	With many plates, illustrations, mapsand tables. Less than a dozen complete sets of the Journal remain on hand. Prices on application. Those wishing to fill broken sets can secure most of the needed volumes separately. An index to the first 50 volumes has been issued rary Medals. March, 1910. New and revised edition. New York. 10911. xxxvi, 412 pages, 512 illustrations. ' $10.00. NOTES AND MONOGRAPHS Numismatic Notes AND MONOGRAPHS is devoted to essays and treatises on subjects relating to coins, paper money, medals and decorations, and is uniform with Hispanic Notes and Monographs published by the Hispanic Society of America, and with Indian Notes and Monographs issued by the Museum of the American Indian—Heye By How.ianp Woop When Napoleon in 1808 took over the rights to the Spanish crown and confined Ferdinand VII a prisoner at Bayonne, the results and consequences of this action were of far-reaching import. This usurpation on the part of Napoleon caused intense feeling in the Spanish possessions in the New World, and a struggle soon arose between the supporters of the monarchy and the adherents of freedom. Standards of revolt and of independence were set up by different leaders in various parts of South America and Mexico, meeting with changing fortunes for about ten years. Gradually the different political divisions won their freedom and established themselves as Republics. T E Gg Cl GA es The coinage of Spanish America for the second and third decades of the Nineteenth Century is indicative of the stirring events and changes of this period. The topic under discussion, however, is with a series of tworeal pieces issued at Tegucigalpa, Honduras, in 1823, during the last months of Mexican domination under Iturbide or Augustin, and the transitional period after his downfall. The series is remarkable on account of the variety of designs and combinations of dies bearing the date 1823. The issues seem to have begun and ended within that year. In an article written in 1888 by José Esteban Lazo entitled Historia de la Moneda en Honduras, no mention is made at all of this 1823 issue. As the account goes much into detail concerning other periods of the coinage, 1t seems probable that examples of this coinage are no longer found in Honduras, and that no records are now extant. Repeated inquiries have borne no fruit. Sefior Lazo, however, mentions a coinage at Tegucigalpa in 1822, but coins bearing this date are apparently unknown. It is possible that these have disappeared completely, or were this coinage by Sefior Lazo is of interest: “In the year 1822 Don Juan Lindo, a member of the Mexican Cortes, brought from Mexico to Tegucigalpa a die to ‘coin’ reals and half-reals in cut money. The minting took place in the building of the Convent of San Francisco, but there were many falsifications, and it was resolved to give up the minting for this reason. There are no facts in regard to the number struck.” With the exception of some proclamation pieces struck by Augustin of Mexico in Guatemala, Chiapas and Quezaltenango in 1822, the above coins constitute the only issues in Central America of this revolutionary period. TEGUCIGALPA 1824, and coins of the same design, the common type with sun,mountains and tree, were struck in Honduras in 1830. These had the mint mark T, for Tegucigalpa. Costa Rica adopted this design in 1831. In the meantime, similar pieces were inaugurated in Nicaragua in 1825. Salvador had a provisional coinage from 1828 to 1835. For a better understanding of this coinage of 1823, a brief word regarding the history leading up to this period is necessary. On the whole, Central America remained loyal to Ferdinand and the Junta Suprema during the time the greater part of Spanish America was in revolt. Although feeling ran high and opposing parties were formed, no real rupture occurred until 1821. Especially was this true as long as Ferdinand remained in the power of Napoleon. On his release in 1814, he aroused much antagonism by a manifesto setting aside the constitution. This, under compulsion, he restored in 1820, but conciliatory actions on the part of Spain were too late. Revolutions in Mexico, for a time suppressed, were breaking out again under Iturbide. On February 24, COLNAG EOF 91.823 1821, the Plan of Iguala was formulated, when Guerrero and the Spanish Viceroy O’Donaju joined with Iturbide and proposed an independent monarchy with a ruler from the Spanish Royal Family. Chiapas in the Captain-Generalcy of Guatemala was the first to break away and link itself with Mexico. Independence was proclaimed in Guatemala on September 15, 1821, when it was decreed that representatives should be chosen for a National Congress of Central America. The officials at Comayagua, in Honduras, took an oath to support the Plan of Iguala, which meant a virtual submission to the Mexican Empire. The Partidos of Tegucigalpa and Gracias, and the ports of Omoa and Trujillo, would not agree to this and maintained relations with the Guatemala Assembly, to which they sent representatives. Independence from Spain was declared on October 16, 1821. In Nicaragua, some provinces voted to join the Assembly at Guatemala, but the majority voted to become a part of Mexico. Salvador cast her lot with Guatemala. LEG UCL a The idea of a union with Mexico became every day more popular. Iturbide had grandiose ideas of Imperial sway and was determined on the acquisition of the whole of Central America. On January 5, 1822, the Junta by decree made the whole of the country a part of the Empire of Mexico. Salvador and certain sections of Honduras still held out. . On the overthrow of Iturbide in March, 1823, Central America became autonomous, A Resolution was adopted on March 20, 1823, which called together a Congress of all the provinces to carry out the Act of September 15, 1821, which had been annulled by the fifteen months’ incorporation of the country with Mexico. Various steps \| were then taken to enter into a union with the other provinces to constitute an independent Central American nation. Congress assembled on June 24, 1823, and an Ordinance of Independence was adopted on \| July 1, and ratified on October 1, of this eventful year. silver. At least nine distinct dies were used producing eight combinations. This in itself is unusual, especially if the pieces were struck within the year 1823. The’ dies were undoubtedly made within that year, and all the coins were most likely struck before 1824. No great number could have been issued, judging by their extreme rarity. It is a remarkable fact that these coins are all of the denomination of two-reals. The sequence of the dies, with the exception of No. 1, is difficult to determine exactly. The coins .themselves with their several die-combinations are even more complicated when assigning their proper order. The present arrangement is consequently merely tentative. The initials on the pieces may give a clue if the precedent of the South American mints is followed which placed the initials of the mint officials on the coins. _ In the Tegucigalpa series are found two sets of letters—M. P. and L. A. It can be \| safely said that the coin bearing the head of Augustin (No. 1) was the initial coinage, as it must have been struck before the downfall of the Emperor in March. ‘This piece bears the letters M. P. The other dies bearing the same letters should follow; then the coins with the initials L. A. showing a change of mint personnel. The L. A. coins are combined with the M. P. initials on the other side, but this might be explained by the fact that the earlier dies were used in conjunction with those newly cut. The practice apparently was to use indiscriminately any pair of dies on hand for the sake of economy. This consideration of the letters M. P. as initials of mint officials might be challenged. They might possibly stand for the abbreviation of Moneda Provisional. On coins Nos. 4 to 7 the inscriptions read M. TEGVSIGALPA and M. PROVISIONAL. In these instances the M undoubtedly stands for Moneda. It would seem extremely doubtful that the letters M. P., Nos. 1, 2 or 3, can be anything else than the initials of mint officials. Certainly No. 1 cannot be considered a provisional issue; and the transposal of the letters on the reverse of No. 2 would militate against such a theory. Medina considers the initials L. A. stand for Avo Libertad in his description of No. 6. He has undoubtedly mis-read the inscription, placing a second 3 after the date, interpreting it as the third year of liberty. There is no second 3 on the coin. t Obv. Crudely executed head of Augustin to left, ENPER (sic) . AGVSTIN . 1823 Rev. Crowned Mexican eagle on cactus, M.P.---2 R. There is no indication of the minting place on this piece, but the mint is clearly established by Nos. 6 and 8 which have the same reverse die used in conjunction with dies inscribed TEGUSIGALPA. The workmanship is decidedly inferior to the proclamation reals issued in Guatemala and Chiapas the preceding year. MArcu. 2 Obv. Castles and lions within the compartments of a cross,.enclosed within four sets of double semi-circles; at sides, M—P; around, PLVSVLTRA; the rest of the circle filled with a rope pattern. Rev. Pillars of Hercules above two wavy lines. In three lines divided by two horizontal lines, P-2-M \| LV-SVL-TR \| T-823-G. Good silver. 26 mm. Plate I American Numismatic Society. Inedited. Although this piece has many of the characteristics of the Caracas issues of 1817-1821 , the workmanship is considerably different. It can also be compared with the extensive series of one-real and two-real pieces which were struck on thin and thick planchets, and noted chiefly for the many impossible dates they bear.’ The piece is included here particularly on account of the letters m.p. The transposal of the M.P. to P.M. on the reverse is in accordance with the customs of the Lima and Potosi mints. It is suggested that the T G is an abbreviation of Tegucigalpa. Obv. Castles and lions within the four compartments of a cross enclosed within four sets of double semi-circles; around, 2 R. M. P. Appleton Sale, New York, 1913, lot 1371. Campaner y Fuertes in Memorial Numismatico Espanol, indicates this combination in the illustrations on Plate VIII by a line connecting the two obverses of Nos. 4 and 6 of this article. Again, we have a coin with no mint indication. The drawing of the coin on Campaner’s plate, while agreeing in every other way with the piece here illustrated, divides the word TEGV-SIGAL-PA. Maillet’s drawing, evidently copied, is consequently the same. the coins. The Royal Arms on this coin may have significance as indicating that this piece was struck by the Spanish party; but the fact that the name of Ferdinand is not The specimen described: in the Ulex Sale answers the description of this piece but is given as without date. It may have been obliterated. 1. Silver reals, two-reals and four-reals from 1817-1821. Although a number of minor varieties occur, the pieces answer to the following description: Obv. Lions and castles within the compartments of a cross enclosed within four scalloped semi-circles; at sides F—7, above and below 1, 2 or 4, according to the value. Rev. The Pillars of Hercules, inscription between three horizontal lines, 1, 2 or 4 \| PLV-SVL-TRA \| B.-1817-S.; below, CARACAS, beneath which three or four wavy lines. 2. These pieces have never been accurately assigned. They fall into two classes, \| on account of style and thickness. It has been suggested that most of the thicker coins, because of the general similarity to certain pieces struck at Rioja, Argentina, in 1822, belong to that locality. The thinner series resembles so closely the style and fabric of the Caracas pieces that the customary assigning of them to COtN GE O.F..1823 Venezuela is doubtless correct. They were most certainly struck during the Revolutionary period in the second and third decades of the Nineteenth Century. The initials are invariably M—L, t—m. The most interesting feature, however, is the dates. Some of those noted are as follows: 23, 24, Pe Eel AsetA0, 172, 174, TOi,,182, 184, Coty 1, 721,730, 751, 752) 777; 791; 794, 800, 814, 822, 823, 931, 1816 and 1817.	2,690	common-pile/pre_1929_books_filtered	tegucigalpacoina00wood	public_library	public_library_1929_dolma-0004.json.gz:3788	https://archive.org/download/tegucigalpacoina00wood/tegucigalpacoina00wood_djvu.txt
umeLnrrwpKfPQtXS	7.2: Sexually Transmitted Infections	7.2: Sexually Transmitted Infections By the end of this section, you will be able to: - Educate patients on how to prevent and treat sexually transmitted infections that occur in persons assigned female at birth - Describe common sexually transmitted bacterial and protozoan infections that occur in persons assigned female at birth - Describe common sexually transmitted viral infections that occur in persons assigned female at birth - Identify applicable nursing interventions when caring for a person assigned female at birth who has a sexually transmitted infection Sexually transmitted infections ( STI s) affect people in all areas of the world. STIs are not specific to those of certain age groups, demographics, or economic status. STIs are specifically transmitted by passing an organism between sexual partners through oral, anal, or vaginal contact (Garcia et al., 2023). This section will review sexually transmitted infections that affect people assigned female at birth. Prevention of Sexually Transmitted Infections Sexually transmitted infections can be prevented only by eliminating sexual contact. However, the following safer sex practices discussed can significantly reduce the risk of transmission. It is important for all persons to have a trusting relationship with their health-care providers so that they can discuss concerns and ways to be safe during sexual contact. Health-care providers should be able to communicate with their patients effectively so that the patient feels safe and able to discuss issues. The provider should be nonjudgmental in their approach (Garcia et al., 2023). In all situations, providers should avoid stigma , negative attitudes and beliefs that motivate the general public to fear, reject, avoid, and discriminate against a group of people. The person with the STI may not have any symptoms but can still transmit the infection (American College of Obstetricians and Gynecologists [ACOG], 2023). Using a tool like the 5P’s can help the nurse or provider in talking to patients about STI risks (Table 7.1. \| Category \| Sample Questions \| \|---\|---\| \| Partners \| \| \| Practices \| \| \| Protection from STIs \| \| \| Past history of STIs \| \| \| Pregnancy intention \| \| Abstinence Abstinence is the only way to 100 percent prevent STIs. This includes not having vaginal, anal, or oral sex (Centers for Disease Control and Prevention [CDC], 2022). Not all people will practice abstinence, so it is important that they know all other options that are available. Sexual Behaviors Some sexual behaviors can increase the risk of STIs. For adolescents, biologic factors may increase this risk. Younger females with immature cervical epithelia have higher levels of cytokines and chemokines. The immature epithelium is thought to be more susceptible to STI pathogens, especially N. gonorrhoeae, C. trachomatis , and human papillomavirus (Fortenberry, 2023). For example, condoms are very effective. Consistent and correct use of condoms can lower the risk of all STIs. Condom use can reduce the transmission of HIV by 80 percent to 95 percent (Rietmeijer, 2023). A new condom should be used with each sex act, and the condom should be handled correctly to avoid damage. Only water-based or silicone-based lubricants should be used with condoms, as other types of lubricants can break down the latex, allowing STI pathogens and sperm to escape. The external condom should be held firmly against the base of the penis during withdrawal to decrease exposure to bodily fluids (CDC, 2021a). Internal condoms (condoms that are inserted into the vagina) are available and can protect against acquiring and transmitting STIs. Cervical diaphragms are not recommended as protection against STIs (CDC, 2021a). Topical microbicides and spermicide s should not be used as the primary prevention of STIs, either. Vaccines are available for several STIs, including hepatitis A , hepatitis B , human papillomavirus (HPV) infection, N. meningitidis infection, and Mpox (Rietmeijer, 2023). Take Action: Teaching about Proper Condom Use - Do not use 5 years after the manufacturing date, at any time after the expiration date, or at any time the packaging is damaged. - If using lubricant, it must be water or silicone based. - A new condom should be used for each sex act. - The condom should be handled carefully to prevent tears. - Do not use internal and external condoms simultaneously. Education and Community Programs about STI Prevention All health-care providers and nurses should be trained to counsel on STI prevention. The CDC (2021) also recommends prevention counseling for all sexually active persons who currently have an STI, who had an STI in the past year, or who have multiple partners. Counseling should include information about how STIs are transmitted, behaviors that can increase the risk, and suggestions to adjust behaviors to decrease the risk (Rietmeijer, 2023). It is important for the counseling to include all sexual behaviors that expose the person to an STI, to assess what the patient understands about how STIs are transmitted, to assess the person’s readiness to change, to negotiate a goal, and to identify a realistic first step in getting to the goal (Rietmeijer, 2023). This counseling can be done in an individual outpatient setting, in-person counseling, telemedicine visit, or via media messages such as text or written material. Peer-group sessions have been shown to improve outcomes but may be more difficult to coordinate (Rietmeijer, 2023). Public education and awareness are still needed about STIs. This can occur in peer groups, schools, families, and communities. Provider education about a holistic approach to sexual health may improve responsiveness (U.S. Department of Health and Human Services, 2020). Bacterial and Protozoan Sexually Transmitted Infections Various bacteria and protozoa can cause STIs. It is important to determine what type of organism is causing the STI in order to treat it correctly. The health-care provider will test for STIs and treat according to the CDC recommendations. Gonorrhea One common STI is gonorrhea , which is caused by gram-negative bacteria called Neisseria gonorrhoeae (Figure 7.2). As the bacteria invade the endothelium and spread, patients have signs and symptoms of infection; however, some patients are asymptomatic and do not know they are carrying the bacteria. Signs and symptoms can include: - inflammation of the vagina - itching of the vagina - mucopurulent discharge from the vagina - dysuria - urinary urgency and frequency - lower pelvic pain - rectal pain or bleeding - abnormal vaginal bleeding (CDC, 2021a) Incidence Gonorrhea is on the rise in the United States, with 583,405 cases reported in 2018. This is a rate of 171.9 cases per 100,000 population, compared to a rate of about 100 cases per 100,000 population in 2012 (U.S. Department of Health and Human Services, 2020). In 2020, there were approximately 82 million cases of gonorrhea worldwide (World Health Organization [WHO], 2023). The bacterium Neisseria gonorrhoeae infects the mucous membranes in the reproductive tract, mouth, throat, eyes, and rectum (U.S. Department of Health and Human Services, 2020). Screening and Diagnosis All sexually active people assigned female at birth who are less than 25 years old and all persons assigned male at birth having intercourse with persons assigned male at birth should be screened for gonorrhea every year. Other high-risk populations, such as those with multiple anonymous partners, those in which either partner has a substance use disorder, or those at risk for HIV acquisition, should be screened at all anatomic sites of exposure every 3 to 6 months. Screening for gonorrhea is not recommended for cisgender heterosexual persons less than 25 years of age who are at low risk for infection (CDC, 2021a). Cultures or polymerase chain reaction ( PCR ) tests are used to diagnose gonorrhea. In people with a vagina, endocervical swabs are used; and in people with a penis, urethral swab s are used. Rectal, oropharyngeal, and conjunctival cultures or PCR tests using a swab can also be done to check for infection. Urine cultures for gonorrhea can also be performed (CDC, 2021a). Management and Treatment Gonorrhea is one STI that must be reported to the Department of Health in every state in the United States (CDC, 2021a). Drug-resistant strains of gonorrhea are resistant to fluoroquinolone , cefixime, and extended-spectrum cephalosporins, and these strains have been seen throughout the world. The standard treatment for gonorrhea is ceftriaxone (Rocephin) 500 mg IM in a single dose for persons weighing < 150 kg (330 lb) and ceftriaxone 1,000 mg IM for persons weighing ≥ 150 kg (330 lb). If the patient has a cephalosporin allergy, they can take gentamicin (Garamycin) 240 mg IM in a single dose PLUS azithromycin (Zithromax) 2 g orally in a single dose. If ceftriaxone is not available, the patient can take cefixime (Suprax) 800 mg orally in a single dose (CDC, 2021a). Complications Untreated gonorrhea can lead to pelvic inflammatory disease ( PID ), which can cause chronic pelvic pain, infertility, and ectopic pregnancy due to scarring in the reproductive tract. There is an increased risk of HIV infection. Gonorrhea can also cause a disseminated infection, which can lead to skin lesions, arthralgias, and arthritis (CDC, 2021a). Patient Education Recent sex partners (within the past 60 days) should get referred for evaluation, testing, and presumptive treatment. If greater than 60 days, then the most recent partner should be treated. If access to care is limited and the partner does not seek their own evaluation, the patient’s provider or a local pharmacy can provide treatment to the partner or partners if they live in a state where this is permitted (CDC, 2021a). Symptoms should subside with treatment, but if symptoms persist, repeat testing should be performed. The patient should abstain from sexual activity until 7 days after treatment and until all sex partners are treated. People with gonorrhea should get tested for other STIs, including chlamydia, syphilis , and HIV (CDC, 2021a). The CDC (2021) recommends a test of cure (TOC), a retesting to determine that the treatment was successful, in 3 months for uncomplicated gonorrhea that has been treated. Chlamydia The gram-negative bacterium Chlamydia trachomatis causes the STI chlamydia (Figure 7.3). The prevalence of chlamydia is highest in persons 24 years old or younger. Asymptomatic infection is usually found in patients during screening (CDC, 2021a). Some patients will have the following symptoms, while others will be asymptomatic: - unusual vaginal or penile discharge; - burning with urination; - pain in the back or abdomen; - fever; - pain during sex; - bleeding between periods; and - rectal pain, bleeding, or discharge. Incidence Chlamydia is the most common bacterial STI in the United States, with 1,758,668 cases reported in 2018 (U.S. Department of Health and Human Services, 2020). There were more than 129 million reported cases of chlamydia worldwide in 2020 (WHO, 2023). Screening and Diagnosis All sexually active persons assigned female at birth < 25 years old should be screened every year. A diagnosis can be made by obtaining a vaginal or cervical swab, a Papanicolaou (Pap) test, or a first-void urine for those assigned female at birth. In persons assigned male at birth, the diagnosis can be made by a first-catch urine or a meatal or urethral swab (CDC, 2021a). Management and Treatment Chlamydia is a reportable STI in every state in the United States. The provider or lab must report cases to the Department of Health (CDC, 2021a). Treatment for chlamydia is usually doxycycline (Vibramycin) 100 mg orally 2 times a day for 7 days. Alternative treatments are azithromycin (Zithromax) 1 g orally once or levofloxacin (Levaquin) 500 mg orally once a day for 7 days. Repeat testing is not recommended. For pregnant persons, doxycycline is contraindicated in the second and third trimesters, but azithromycin is safe. Follow-up testing for pregnant persons should be done about 4 weeks after treatment to ensure there is no more infection. Complications Chlamydia that is untreated can cause serious complications. Persons assigned female at birth are at risk for developing pelvic inflammatory disease (PID), which can cause chronic pelvic pain, infertility, and ectopic pregnancy due to scarring of the reproductive tract. Chlamydia can increase the risk of transmitting or acquiring HIV . In pregnant persons, chlamydia can cause preterm birth and serious complications in the neonate, such as ophthalmia neonatorum or pneumonia (CDC, 2021a). Patient Education Recent sex partners (within the past 60 days) should get referred for evaluation, testing, and presumptive treatment. If greater than 60 days, then the most recent partner should be treated. If access to care is limited, the patient or local pharmacy can provide treatment to the partners (CDC, 2021a). Persons receiving treatment should abstain from sexual activity for 7 days after the single-dose regimen or until completion of a 7-day regimen and resolution of any symptoms. Pregnant persons who receive treatment need to have a TOC at approximately 4 weeks after treatment; nonpregnant persons do not need a TOC if they completed their treatment (CDC, 2021a). STI Concerns for Persons Assigned Female at Birth (AFAB) with AFAB Intimate Partners Providers should not assume that persons AFAB who are having sex with AFAB partners are at low risk for STIs and HIV. Providers should determine risk based on sexual history. There is limited data on the transmission of STIs among persons AFAB having sex with AFAB partners. Routine screening should include HIV, chlamydia, and gonorrhea for all sexually active patients under age 25 and those ≥ 25 years of age if at increased risk. (CDC, 2021a) Trichomoniasis The single-celled anaerobic protozoa Trichomonas vaginalis causes trichomoniasis , the most common nonviral STI in the world (Figure 7.4). Most persons assigned female at birth have no symptoms or mild symptoms such as a vaginal discharge that can be malodorous, yellow-green, and frothy. The person may also experience vulvar irritation (CDC, 2021a). Incidence Trichomoniasis is one of the most prevalent nonviral STIs in the world. It is thought to affect approximately 2.6 million people in the United States (CDC, 2021a). It is not a reportable STI, so estimates may be inaccurate. Trichomonas is a protozoan that can survive on fomites, such as towels and toilet seats, but transmission via fomites has not been proven. Persons AFAB can transmit trichomoniasis to any partner regardless of sex. Persons AMAB normally acquire this only from persons assigned female at birth (Sobel & Mitchell, 2023). Screening and Diagnosis Routine screening for trichomoniasis is not recommended. Up to 70 percent of the population who have it may not have symptoms, so screening for it is recommended only for patients who have HIV or who are in high-prevalence settings, such as STI clinics and correctional facilities, or for patients with new or multiple sex partners, with a history of sex work, or with a history of STIs (Sobel & Mitchell, 2023). A vaginal or urethral swab using nucleic acid amplification tests ( NAAT s) is the best way to diagnose trichomoniasis; however, microscopic and pH testing can be used if necessary (Sobel & Mitchell, 2023). Management and Treatment The treatment for persons AFAB is metronidazole (Flagyl) 500 mg 2 times a day for 7 days; for persons AMAB, the treatment is metronidazole 2 g orally in a single dose. Metronidazole (Flagyl) Metronidazole (Flagyl) is used as a treatment for trichomoniasis and bacterial vaginosis. - Generic Name : metronidazole - Trade Name : Flagyl - Class/Action : amebicide - Route/Dosage : 500 mg twice a day for 7 days - Indications : for treatment of trichomoniasis and bacterial vaginosis - Mechanism of Action : bactericidal - Contraindications : hypersensitivity, Cockayne syndrome, and first trimester of pregnancy - Adverse Reactions/Side Effects : depression, trouble sleeping, headache, dizziness, weakness, nausea, vomiting, anorexia, diarrhea, constipation, rash, itching, mouth sores, and vaginal itching - Nursing Implications : Educate patient about use. - Parent/Family Education : Do not drink alcohol or consume foods that contain propylene glycol while taking medication or for 3 days after completion. Do not take during first trimester of pregnancy. Complications For persons who are pregnant, trichomoniasis is associated with adverse outcomes such as premature rupture of membranes, preterm delivery, and delivery of a small for gestational age infant (CDC, 2021a). Trichomoniasis is also associated with increased risk of HIV transmission and pelvic inflammatory disease (CDC, 2021a). Patient Education Persons should be instructed that their partners need treatment and that they should abstain from sexual activity for approximately 7 days after they and their partners have completed treatment and no longer have symptoms. Retesting is recommended for all persons assigned female at birth at approximately 3 months after treatment, even if partners have received treatment, because of the high rate of reinfection (CDC, 2021a). Syphilis The spirochete bacterium Treponema pallidum (Figure 7.5) causes the STI syphilis . Syphilis presents in four different stages, with each stage having its own characteristics. Health-care providers will develop a treatment plan according to the stage. Treatment for syphilis is important, as untreated syphilis can be detrimental and cause lifelong complications. For pregnant patients, syphilis can cause multiple problems with the fetus, such as miscarriage or birth defects (CDC, 2021a). Symptoms and Incidence Syphilis is a treatable STI, caused by the bacterium Treponema pallidum , that affected approximately 115,045 people in the United States in 2018. This was a 71 percent increase in the number of cases of syphilis in the United States since 2014, when the number of cases was approximately 67,000. There were approximately 7.1 million cases of syphilis worldwide in 2020 (WHO, 2023). Untreated syphilis progresses in stages. Primary syphilis presents as a chancre , a genital sore or lesion where syphilis pathogens enter the body (Figure 7.6). It is usually painless and may go unnoticed. Secondary syphilis presents as a rash or lesions away from the primary site. This can begin when the initial site is healing or healed. It usually is not itchy and may be faint. It can occur anywhere on the body, although the hands and feet are common sites (Figure 7.7). Other symptoms associated with secondary syphilis are myalgia, pharyngitis, swollen lymph nodes, headaches, patchy hair loss, muscle aches, or fatigue (Tudor et al., 2023). Latent stage syphilis occurs when there are no signs and symptoms, but syphilis remains in the body. Early latent syphilis is when infection occurred within the past 12 months, and late latent syphilis is when the infection occurred more than 12 months previously. Tertiary syphilis is rare, but it can affect many body organs, including the cardiac and neurologic systems. It can invade any organ (Tudor et al., 2023). It can occur 10 to 30 years after the initial infection and can be fatal. Neurosyphilis occurs when the infection invades the nervous system, causing headaches, muscle weakness, paralysis, trouble with movement, numbness, or changes in mental status. Ocular syphilis invades the visual system and can cause eye pain, redness in the eye, floaters, sensitivity to light, and changes in vision. Otosyphilis occurs when the infection invades the auditory and/or vestibular system and can cause hearing loss, ringing in the ears, difficulty with balance, and dizziness. Congenital syphilis occurs when a pregnant person transmits the infection to a fetus during pregnancy (U.S. Department of Health and Human Services, 2020). Screening and Diagnosis All pregnant persons should be screened for syphilis at their first prenatal visit and again in the third trimester, as mandated by most states. For pregnant patients who live in communities with high rates of syphilis or who have a risk of acquiring syphilis during pregnancy, testing should be done twice in the third trimester, at 28 weeks and at the time of delivery (CDC, 2021a). Darkfield examinations and molecular tests for detecting syphilis directly from a lesion or tissue are the definitive methods for diagnosing early syphilis and congenital syphilis; however, they can have a false-negative result if the patient has applied a topical antibiotic (Tudor et al., 2023). A presumptive diagnosis of syphilis requires two laboratory serologic tests: a nontreponemal test such as the Venereal Disease Research Laboratory (VDRL) or the rapid plasma reagin (RPR) test and a treponemal test such as the T. pallidum passive particle agglutination (TP-PA) assay, various enzyme immunoassays (EIAs), chemiluminescence immunoassays (CIAs) and immunoblots, or rapid treponemal assays (CDC, 2021a). Nontreponemal tests are easy to perform and inexpensive, but they are not specific for syphilis. There is the possibility of false-negative results in patients during primary syphilis and possible false-positive results in patients without syphilis or with previously treated syphilis. The nontreponemal tests can give false-positive results in patients with HIV, some autoimmune conditions, vaccines, injectable drug use, pregnancy, and older age. A confirmatory treponemal test is required. The treponemal test will confirm the positive if it is a true positive test (CDC, 2021a; Tudor et al., 2023). Management and Treatment Syphilis is a reportable STI in every state in the United States. The provider or lab must report cases to the Department of Health (CDC, 2021a). Treatment of latent, primary, and secondary syphilis is penicillin G benzathine (Bicillin L-A) 2.4 million units IM in a single dose. Later phases of syphilis should be treated with 1 injection per week for 3 weeks (WHO, 2023). Patients with neurosyphilis, ocular syphilis, or otosyphilis should be treated with penicillin G aqueous (Pfizerpen) 18 to 24 million units per day, administered as 3 to 4 million units IV every 4 hours or continuous infusion for 10 to 14 days (CDC, 2021a). Pregnant women with all phases of syphilis should receive the same penicillin treatment. If they are allergic, they should be desensitized and treated with penicillin because it is the only medication with documented efficacy in pregnancy (CDC, 2021a). Complications Treatment of syphilis can sometimes be too late to prevent permanent damage to the patient. Once this damage occurs, treatment will not reverse these problems. The spread of syphilis can cause permanent damage to the brain and neurologic system, causing pain, heightened or loss of sensations, visual problems that can lead to blindness, and stroke. Permanent cardiovascular changes can lead to aortic aneurysm, a weakening of the aorta causing a bulging area that can rupture. Some patients will have gastric changes that lead to weight loss, pain, and vomiting. Untreated syphilis during pregnancy can lead to miscarriage, stillbirth, or preterm delivery. Infants born with congenital syphilis may be asymptomatic at birth but can suffer from hepatomegaly, jaundice, rash, nasal discharge, lymphadenopathy, and skeletal abnormalities. They can develop fetal hydrops (abnormal accumulation of fluid in the fetal tissues), myocarditis, pneumonia, sepsis, and central nervous system dysfunction that can lead to hydrocephalus, cranial nerve palsies, optic atrophy, blindness, deafness, neurodevelopmental regression, seizures, and fetal death (Arrieta, 2023). These problems can be prevented with adequate treatment during the prenatal period. Patient Education Patients should get tested at 6 months and 12 months after treatment. All patients testing positive for syphilis should get tested for HIV. All sex partners within 90 days prior to diagnosis should receive treatment for syphilis (CDC, 2021a). Pelvic Inflammatory Disease Pelvic inflammatory disease ( PID ) is an inflammatory disorder of the upper female genital tract that can be caused by various STIs, notably gonorrhea and chlamydia. Screening and treating for gonorrhea and chlamydia can reduce the incidence and long-term side effects of PID (CDC, 2021a). Incidence Data on the incidence of PID are limited because signs and symptoms vary between people infected and there is no diagnostic test that can easily detect PID. Screening and Diagnosis There is no screening for PID because it is caused by multiple organisms, and diagnosis can be difficult because the symptoms vary. Laparoscopy can be used to make an accurate diagnosis of inflammation in the fallopian tubes and pinpoint bacteria but cannot identify endometritis and may also miss mild inflammation in the fallopian tubes. This test is not readily available and may not be justified for mild symptoms (CDC, 2021a). No history, physical, or laboratory finding can make a definitive diagnosis. Persons assigned female at birth most often present with lower abdominal pain. It is usually bilateral, can occur suddenly, and can last up to a few weeks. Pain can be subtle, and the patient could notice worsening pain with coitus or with sudden, jarring movement. The onset of pain is more likely to occur during or shortly after menses. Abnormal uterine bleeding, urinary frequency, and abnormal vaginal discharge are possible symptoms. During a physical exam, there may be abdominal tenderness with palpation, worse in the lower quadrants. Rebound tenderness, fever, and decreased bowel sounds may be present in patients with severe cases (Ross & Chacko, 2022). A presumptive diagnosis of PID should be used for persons assigned female at birth who are young and sexually active and all others who are at risk for STIs if they are experiencing pelvic or lower abdominal pain, if no other cause for the illness can be identified, and if one or more of the following three minimum clinical criteria are present on pelvic examination: cervical motion tenderness, uterine tenderness, or adnexal tenderness. This is the most common way that PID is diagnosed (CDC, 2021a). More than 85 percent of cases of PID are caused by STIs; therefore, all patients with possible PID should be tested for STIs. A negative STI result does not rule out PID, but a positive one warrants treatment. Some persons assigned female at birth do not have symptoms of PID and may never be diagnosed with this disease until they have tubal-related fertility issues due to scarring of the fallopian tubes (Ross & Chacko, 2022). Management and Treatment Parenteral treatment for PID has improved effectiveness over oral treatment. Intramuscular or oral treatment could be considered for patients with mild to moderate acute PID. Table 7.2 summarizes PID treatment options. \| Type of Treatment \| Treatment \| \|---\|---\| \| Parental (treatment is usually 24–48 hours, then transitioned to oral medications) \| 1. Ceftriaxone 1 g IV every 24 hours PLUS Doxycycline 100 mg orally or IV every 12 hours PLUS Metronidazole 500 mg orally or IV every 12 hours \| \| 2. Cefotetan (Cefotan) 2 g IV every 12 hours PLUS Doxycycline 100 mg orally or IV every 12 hours \| \| \| 3. Cefoxitin (Mefoxin) 2 g IV every 6 hours PLUS Doxycycline 100 mg orally or IV every 12 hours \| \| \| IM and oral regimens \| 1. Ceftriaxone 500 mg IM in a single dose PLUS Doxycycline 100 mg orally 2 times/day for 14 days WITH Metronidazole 500 mg orally 2 times/day for 14 days \| \| 2. Cefoxitin 2 g IM in a single dose and probenecid (Benemid) 1 g orally administered concurrently in a single dose PLUS Doxycycline 100 mg orally 2 times/day for 14 days WITH Metronidazole 500 mg orally 2 times/day for 14 days \| \| \| 3. Other parenteral third-generation cephalosporin (e.g., ceftizoxime or cefotaxime) PLUS Doxycycline 100 mg orally 2 times/day for 14 days WITH Metronidazole 500 mg orally 2 times/day for 14 days \| Complications Pelvic inflammatory disease during pregnancy places a pregnant person at risk for maternal morbidity and preterm delivery. Pregnant persons with PID may need to be hospitalized and treated with IV antibiotics (ACOG, 2022). They may require a consultation with an infectious disease specialist (CDC, 2021). Persons with PID are at risk for reoccurrence. They are also at risk to develop hydrosalpinx, where the fallopian tube gets blocked, fills with fluid, and gets enlarged; chronic pelvic pain; infertility; ectopic pregnancy; and ovarian cancer (Peipert & Madden, 2021). Infertility is a serious complication of PID because PID can often reoccur and can cause tubal and epithelial destruction, which can affect fertility. PID can cause permanent injury to the fallopian tube, including loss of ciliary action, fibrosis, and occlusion of the tube. After PID resolves, hydrosalpinx can occur and cause difficulty with implantation of the blastocyte (Peipert & Madden, 2021). Table 7.3 summarizes bacterial and protozoan STI s and PID. \| Disease \| Organism \| Signs and Symptoms \| Lab Diagnosis \| Treatment per CDC Guidelines \| \|---\|---\|---\|---\|---\| \| Pelvic inflammatory disease (PID) \| Numerous organisms can cause PID: Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Treponema pallidum \| Abdominal tenderness, adnexal tenderness, and cervical motion tenderness; fever, vaginal discharge, irregular menstrual bleeding, pelvic pain, pain with intercourse, painful and frequent urination, and uterine tenderness \| Test for Neisseria gonorrhoeae and Chlamydia trachomatis ; also test for M. genitalium , HIV, and Treponema pallidum ; also vaginal fluid with large amount of white blood cells (WBCs); elevated erythrocyte sedimentation rate (ESR) and/or C-reactive protein \| Ceftriaxone 1 g IV every 24 hours PLUS doxycycline 100 mg orally or IV every 12 hours PLUS metronidazole 500 mg orally or IV every 12 hours \| \| Gonorrhea \| Neisseria gonorrhoeae \| Dysuria, urinary urgency, urinary frequency, lower pelvic pain, and abnormal vaginal bleeding \| Assigned female at birth: vulvovaginal or endocervical swab, urine sample, Pap smear Assigned male at birth: fresh-catch urine or urethral sample \| Ceftriaxone 500 mg IM in a single dose for persons weighing <150 kg and ceftriaxone 1,000 mg IM for persons weighing ≥ 150 kg; if cephalosporin allergy, patient can take gentamicin 240 mg IM in a single dose PLUS azithromycin 2 g orally in a single dose; if ceftriaxone not available, use cefixime 800 mg orally in a single dose \| \| Chlamydia \| Chlamydia trachomatis \| No symptoms, or vaginal discharge, abnormal vaginal bleeding, pelvic pain, urinary frequency, or dysuria; possible fever, abdominal pain, nausea, vomiting, fatigue, and malaise \| Assigned female at birth: cervical or vaginal swab, Pap smear, or first-void urine Assigned male at birth: urethral swab or first-void urine \| Doxycycline 100 mg orally 2 times/day for 7 days OR azithromycin 1 g orally once OR levofloxacin 500 mg orally once a day for 7 days \| \| Trichomoniasis \| Trichomonas vaginalis \| Assigned female at birth: asymptomatic, or foul-smelling discharge, pruritis, dyspareunia, dysuria, and vaginal spotting Assigned male at birth: testicular pain, dysuria, or rectal pain \| Diagnosis using NAAT swab of the vagina, endocervical swab, urinalysis, or urethral sample \| Patients with a vagina: metronidazole 500 mg 2 times/day for 7 days Patients with a penis: metronidazole 2 g orally in a single dose Alternative for all patients: Tinidazole (Tindamax) 2 g orally in a single dose \| \| Syphilis \| Treponema pallidum \| Painless lesion (chancre), rash, can proceed to cardiovascular and neurologic lesions \| Venereal Disease Research Laboratory (VDRL) and rapid plasma reagin (RPR); fluorescent treponemal antibody absorption (FTA-ABS) and the treponema pallidum particle agglutination (TP-PA) assays are needed for confirmation of the diagnosis \| Penicillin G benzathine 2.4 million units to be given by a single IM injection \| Patient Education Patients should experience clinical improvement in less than 3 days after initiation of treatment; if not, they should be hospitalized for possible change in medication and possible laparoscopy . Sex partners should be tested for gonorrhea and chlamydia. People with an IUD who get PID need treatment but do not need to have the IUD removed (CDC, 2021a). Viral Sexually Transmitted Infections Viral STIs are caused by a virus and are not curable. Some viral STIs are preventable with vaccines, and others have treatments available to help with suppression. Human Papillomavirus The double-stranded DNA virus human papillomavirus (HPV) replicates in the basal cell layer of stratified squamous epithelial cells, which then replicate and cause hyperplasia and possible cancer. HPV is the most common cause of cervical dysplasia, as well as the majority of cervical, penile, vulvar, vaginal, anal, and oropharyngeal cancers and precancers (CDC, 2021a). Incidence Human papillomavirus is the most common sexually transmitted infectious organism in the United States and the world (Garcia et al., 2023). Approximately 79 million Americans are infected with HPV (U.S. Department of Health and Human Services, 2020). Globally in 2020, about 300 million patients had HPV (WHO, 2023). There are 150 types of HPV, and at least 40 of them affect the genital area. Many types of HPV do not cause any symptoms and are self-limiting. However, types 6 and 11, as well as some others, cause about 90 percent of all anogenital warts. Anogenital warts can be painful and itchy, or they can be asymptomatic. HPV types 16 and 18 cause most cervical, penile, vulvar, vaginal, anal, and oropharyngeal cancers and precancers (CDC, 2021a). Globally, cervical cancer is the most common cancer in persons assigned female at birth and is most often caused by HPV (Palefsky, 2022). Male Circumcision and HPV Male circumcision protects against a variety of STIs. HPV is the most common STI, and numerous studies have shown that male circumcision can decrease the circumcised patient’s risk of acquiring HPV. When looking further at these studies, the incidence of HPV in AFAB partners of the circumcised person was also decreased. The exact mechanism of how this occurs is unknown. It is also possible that circumcision removes immune cells from within the foreskin, causing different cytokine environments and inflammatory responses to pathogen entry (Shapiro et al., 2023). The American Academy of Pediatrics (AAP) states that the benefits of male circumcision outweigh the risks, but the benefits are not enough to recommend universal circumcision for all males (Task Force on Circumcision et al, 2012). Therefore, it is the decision of the parents or guardians to determine if the male is circumcised (Guevara et al., 2021). Screening and Diagnosis During cervical cancer screening , HPV testing can be performed using the same sample. However, annual cervical cancer screening is not recommended for all patients with a vagina who are at average risk. This includes patients with no previous cervical cancer or high-grade precancer, those who are not currently under close follow-up for abnormal results, those not immunocompromised, and those who had no exposure to diethylstilbestrol in utero. For patients 21 to 29 years old, a study of cells, or cytology test (in this case, a Pap smear ) to detect abnormal cells is recommended every 3 years. For patients aged 30 to 65 years, a cytology test every 3 years, an HPV test every 5 years, or a cytology plus HPV test every 5 years is recommended (CDC, 2021a). FDA-approved tests for HPV are approved only for cervical specimens and are used to detect oncogenic types of HPV (CDC, 2021a). Age-Based Cervical Screening Recommendations Using Cytology and/or Human Papillomavirus Typing Disclaimer : Always follow the agency’s policy for cervical cancer screening. Definition : Reduce the risk of harm to patients through effective, efficient, and competent performance. Knowledge : The nurse will analyze basic safety principles, understand evidence-based practice standards, and reflect on unsafe nursing practices to ensure that patients are screened properly. Skill : Demonstrate effective strategies to reduce the risk of harm. The nurse will teach all patients AFAB: - Cervical cancer testing (screening) should begin at age 25. - Those aged 25 to 65 should have a primary HPV test every 5 years. If primary HPV testing is not available, screening may be done with either a co-test that combines an HPV test with a Papanicolaou (Pap) test every 5 years or a Pap test alone every 3 years. (A primary HPV test is an HPV test that is done by itself for screening. The U.S. Food and Drug Administration has approved certain tests to be primary HPV tests.) - The most important thing to remember is to get screened regularly, no matter which test you get. - People over age 65 who have had regular screening in the past 10 years with normal results and no history of CIN2 (a cervical biopsy finding of moderately abnormal cells present on the surface of the cervix) or more serious diagnosis within the past 25 years should stop cervical cancer screening. Once stopped, it should not be started again. - People who have had a total hysterectomy (removal of the uterus and cervix) should stop screening (such as Pap tests and HPV tests) unless the hysterectomy was done as a treatment for cervical cancer or serious precancer. People who have had a hysterectomy without removal of the cervix (called a supracervical hysterectomy) should continue cervical cancer screening according to the preceding guidelines. - People who have been vaccinated against HPV should still follow these guidelines for their age groups. Attitude : The nurse will respect their role in cervical cancer screening by adhering to safe, evidence-based practice standards. Management and Treatment There is no cure for HPV. Treatment can be done on genital warts or precancerous lesions caused by the virus (CDC, 2021a). For patients with genital warts, the warts may resolve on their own, but treatment may be preferred for cosmetic reasons. Cryotherapy and/or external medication may be used for treatment. Medications that are self-applied include imiquimod (Aldara) , podofilox (Condylox) , or sinecatechins (Veregen) . A provider can perform cryotherapy with liquid nitrogen, or they can apply trichloroacetic acid or bichloroacetic acid or surgically remove the warts. For patients who test positive for HPV types 16 or 18, a colposcopy should be performed, even if the cytology is normal. For patients with abnormal cytology and a positive HPV, a loop electrosurgical excision procedure (LEEP) of the cervix is often recommended (CDC, 2021a). The HPV vaccine is recommended for all youth aged 11 to 12 and for adults up to age 26 who have not been vaccinated. The vaccine can prevent infection with the types of HPV that cause most genital warts and cancers (U.S. Department of Health and Human Services, 2020). Adults aged 27 to 45 can get the HPV vaccine if they have not been vaccinated and they are at risk for HPV. Less benefit is shown at this age because most adults by this point have been exposed to HPV already (CDC, 2023a). The vaccine has been proven safe and effective, but the rates of vaccination are still low; around 50 percent of youth aged 13 to 17 had completed the vaccine series in 2018 in the United States (U.S. Department of Health and Human Services, 2020). Complications Human papillomavirus infection may present with no signs or symptoms; at other times it can cause genital warts. Human papillomavirus is the number 1 cause of cervical cancer, the fourth most common cancer worldwide in people with a cervix. Approximately 570,000 cases are diagnosed each year, and around 311,000 people die of cervical cancer each year (Palefsky, 2022). In the United States, there were 11,542 new cases of cervical cancer and 4,272 deaths from this cancer in 2020 (CDC, 2023b). Patient Education Nurses should educate patients that HPV often goes unnoticed but can have severe health consequences. The vaccine can prevent HPV, but there is no cure once the person has contracted it. Nurses can encourage patients who have tested positive for HPV to address their immune health by decreasing stress, taking multivitamins, exercising, and engaging in overall healthy habits. Sexual partners can unknowingly share HPV, making it impossible to know where it started (CDC, 2021a). In addition, a person can have HPV for a long time prior to having genital warts or changes on their cervix. Therefore, patient education should include that having a new diagnosis of HPV does not mean their partner is having sex with another person; the virus could have been contracted many years prior (CDC, 2021a). Reporting of Sexually Transmitted Infections Some states in the United States require the provider to report certain STIs to the state or local government. Many states also use partner notification services. All U.S. states have laws that require the reporting of sexual abuse of a child or an older person (Source: CDC, 2021). Herpes Simplex Virus Herpes is a condition caused by the herpes simplex virus (HSV) , an easily transmissible virus that can cause a variety of symptoms in the population. It is a chronic condition that can produce painful lesions in the anogenital area. Severe disease can lead to neurologic involvement (CDC, 2021a). Incidence Herpes simplex virus (HSV) is a global health issue. From 2005 to 2010, approximately 16 percent of the U.S. population aged 14 to 49 acquired HSV-2 (Albrecht, 2022). There are two types of herpes simplex virus: type 1 and type 2. Both can cause genital herpes. HSV can be found in mucous membranes as well as in the lesions or skin affected by the virus. This type of virus can be spread through oral to oral, oral to genital, or genital to genital contact (Johnston & Wald, 2023). Transmission occurs when there is an outbreak or at periods of subclinical shedding, when the patient has no symptoms, making this an easily spread virus (Albrecht, 2022). Screening and Diagnosis Screening for and diagnosis of HSV can be performed depending on where the virus is in the cycle of a lesion. If a lesion is new and has yet to start healing, an HSV NAAT assay test is available. A serum PCR test is available and is the preferred method to diagnose HSV if the infection affects the central nervous system (CNS). This blood test should not be used to detect a genital herpes infection, unless neurologic involvement is suspected (CDC, 2021a). HSV NAAT tests are run on a swab with a specimen from the lesions. This test is the most sensitive but could be negative on older lesions. A viral culture, which is a swab with a specimen from the lesion, may be the only test available but has low sensitivity (CDC, 2021a). Management and Treatment The primary infection is the first time the patient has HSV, and the symptoms are often severe and include painful genital ulcers, dysuria, fever, tender lymphadenopathy, and headache (Albrecht, 2022). Medication should be initiated with the start of an outbreak to maximize effectiveness and reduce the duration of the episode (CDC, 2021a). For the first episode of genital herpes, the preferred treatment is acyclovir (Zovirax) 400 mg orally 3 times a day for 7 to 10 days OR famciclovir (Famvir) 250 mg orally 3 times a day for 7 to 10 days OR valacyclovir (Valtrex) 1 g orally 2 times a day for 7 to 10 days. The virus intermittently sheds, and recurrent episodes can occur. Suppressive treatment can be used to prevent outbreaks. Patients who have HSV may have prodromal symptoms prior to an outbreak, which include tingling, paresthesias, or pruritis (Albrecht, 2022). Treatment taken during the prodromal period can include: - acyclovir 400 mg orally 2 times a day OR - valacyclovir 500 mg orally once a day OR - valacyclovir 1 g orally once a day OR - famciclovir 250 mg orally 2 times a day. If an outbreak occurs, the following can be used and are most effective if started within 1 day of the outbreak: - acyclovir 800 mg orally 2 times a day for 5 days OR - acyclovir 800 mg orally 3 times a day for 2 days OR - famciclovir 1 g orally 2 times a day for 1 day OR - famciclovir 500 mg once, followed by 250 mg 2 times a day for 2 days OR - famciclovir 125 mg 2 times a day for 5 days OR - valacyclovir 500 mg orally 2 times a day for 3 days OR - valacyclovir 1 g orally once daily for 5 days (CDC, 2021a). Pregnant patients who have an active herpes lesion must have a cesarean birth to avoid infecting the newborn. Therefore, patients with recurrent genital herpes should receive suppressive therapy beginning at 36 weeks’ gestation to prevent an outbreak at birth. The therapy should be acyclovir 400 mg given orally 3 times a day or valacyclovir 500 mg given orally 2 times a day until delivery (CDC, 2021a). Complications Most often, HSV causes oral infection or genital lesions, but more severe cases can lead to disseminated infection, pneumonitis, hepatitis, or CNS complications such as meningitis or encephalitis. Immunocompromised patients, such as those with HIV, can have longer and more severe episodes. HSV is one disease in a group of infectious diseases, called TORCH, which can be passed from the pregnant person to the fetus (CDC, 2021a). Approximately 2 percent to 3 percent of all congenital anomalies are attributed to perinatal infection (Jaan & Rajnik, 2023). Intrauterine infection due to maternal primary infection can cause the placenta to necrotize and cause inflammation of the umbilical cord, leading to hydrops fetalis or even fetal demise. This is more common if the HSV infection occurs in the second half of pregnancy (Jaan & Rajnik, 2023). A neonate born after intrauterine infection can have skin vesicles, eye damage, and severe central nervous system problems including microcephaly. Neonates that acquire HSV during delivery can develop localized skin, eye, and mouth diseases (SEM), CNS disease, or disseminated disease (Demmler-Harrison, 2022). Neonates with SEM can progress to CNS or disseminated disease if not treated. Neonates with SEM can have skin lesions, eye watering and pain, and ulcerative lesions of the mouth and tongue. Infants with CNS disease can exhibit seizures, lethargy, irritability, tremors, poor feeding, and temperature instability, where neonates with disseminated virus can have dysfunction of multiple organs, including the liver, lungs, heart, kidneys, and neonatal death (Demmler-Harrison, 2022). Patient Education Herpes simplex virus outbreaks can come and go. Suppressive medication can be used to decrease the severity, duration, and/or frequency of outbreaks. Condoms can help reduce transmission of genital herpes; however, the virus can still be spread through lesions in the genital or anal area that are not covered with the condom . Sexual activity should be avoided during an outbreak (WHO, 2023). Immunocompromised patients, such as those with HIV, could have longer or more severe episodes. Pregnant people with genital herpes can take acyclovir to prevent active lesions at the time of delivery (CDC, 2021a). Hepatitis Inflammation of the liver is called hepatitis , and it is most commonly caused by a virus, such as hepatitis A, B, or C. Hepatitis D and E are rare. Hepatitis can range from mild to severe. Hepatitis A is found in stool and is often passed through the oral-fecal route via contaminated food, drinks, or objects. It can be spread through sexual contact via the oral-fecal route as well (Mehta & Reddivari, 2022). Hepatitis B is a virus that can cause both acute and chronic disease and can be transmitted through blood and body fluids and is more likely to be sexually transmitted (Mehta & Reddivari, 2022). Hepatitis C is most commonly transmitted through infected blood and blood products. It is rarely sexually transmitted (Mehta & Reddivari, 2022). Incidence There are about 1.5 million cases of hepatitis A in the world each year, more common in areas of lower socioeconomic status and less access to clean drinking water. There are rarely relapses, and hepatitis A does not lead to chronic infection (Mehta & Reddivari, 2022). Hepatitis B virus ( HBV ) is a global health problem, with an estimated 250 million HBV carriers in the world. HBV can be spread through blood and body fluids, perinatally; percutaneously, such as in intravenous drug use; and through sexual contact (Lok, 2023). Hepatitis B can spread from a pregnant person to the newborn. Hepatitis C is prevalent in 0.5 percent to 2 percent of the population in the world, with approximately 71 million cases of chronic hepatitis C worldwide. Those who use intravenous drugs and persons who have hemophilia have the highest number of cases (Mehta & Reddivari, 2022). Screening and Diagnosis During the acute phase of HBV infection, serum lab work shows increased levels of alanine and aspartate aminotransferase (ALT and AST, respectively). Serologic testing can determine the acute or chronic phase of HBV infection. Table 7.4 summarizes different tests for HBV and what they indicate. All pregnant persons should be tested for hepatitis B surface antigen (HBsAg) and high-risk patients should be tested again at delivery so that the infant can be treated right after birth (CDC, 2021a). \| Test \| Indications from Results \| \|---\|---\| \| Positive HBsAg \| Acute or chronic infection \| \| Presence of IgM antibody to hepatitis B core antigen (IgM anti-HBc) \| Acute or recently acquired HBV infection \| \| Antibody to HBsAg (anti-HBs) \| Resolved infection or present after vaccination \| \| HBsAg and anti-HBc, with a negative test for IgM anti-HBc \| Chronic HBV infection \| \| Only positive total anti-HBc \| Acute, resolved, or chronic infection or can be a false-positive result \| Management and Treatment There is no treatment for acute HBV infection. However, therapeutic agents can be used with chronic HBV to help achieve suppression and remission of liver disease (CDC, 2021a). Two products are available to prevent HBV. The first is hepatitis B immune globulin ( HBIG ), which is used for postexposure prophylaxis. HBIG is prepared from plasma with high concentrations of anti-HBs and provides short-term (3 to 6 months) protection from HBV. This is usually used in combination with the hepatitis B vaccine for people who have not been vaccinated or did not respond to the vaccination (CDC, 2023a). This, along with the hepatitis B vaccine, is also given to infants born to persons who are HBsAG positive (Drutz, 2023). The hepatitis B vaccine is available and is a three- or four-dose scheduled vaccine. It is recommended for all infants and should be given at any time if the person has not been vaccinated (CDC, 2023a). Complications Hepatitis B virus infection can lead to serious complications, including the development of cirrhosis of the liver, liver disease, hepatocellular carcinoma, and death. Alcoholics with HBV often have accelerated liver disease (Lok, 2023). Patient Education The nurse should teach the patient with HBV infection to avoid alcohol and get vaccinated for hepatitis A and other diseases, such as flu. Family and close friends should get tested and receive the HBV vaccine (Lok, 2023). It is important to complete the whole hepatitis B vaccine series (CDC, 2021a). The person with HBV should always use a latex condom when having sex. The patient should use caution to prevent spreading the virus through blood, such as avoiding needle sharing. People with HBV infection should cover any cuts or lesions to prevent spread and should not share household articles that can be contaminated with blood, such as razors or toothbrushes. Patients with HBV should not donate blood, plasma, body organs or tissue, or semen (CDC, 2021a). Blood used for transfusions is tested for HBV in the United States. Pregnant patients are tested for HBV during pregnancy; those with HBV will need their newborn to receive hepatitis vaccine and hepatitis B immunoglobulin within 12 hours to prevent transmission of the virus (Mehta & Reddivari, 2022) after birth. Visit the Centers for Disease Control and Prevention website for current and trusted information about STIs. Human Immunodeficiency Virus The human immunodeficiency virus (HIV) is an enveloped retrovirus that is encapsulated by two single-stranded RNAs and can be the cause of AIDS. HIV begins as an acute infection that may or may not cause symptoms and then progresses to a chronic infection. Medications can be used to control the virus to undetectable levels and delay or prevent progression to late-stage HIV. Late-stage HIV is known as acquired immunodeficiency syndrome ( AIDS ) and is fatal (CDC, 2021a). Incidence As of 2021, 38.4 million adults and 1.7 million children are living with HIV or AIDS worldwide (Quinn, 2022). In the United States, there are about 1.2 million people with HIV. In 2015, there were 37,800 new cases reported, compared with a decline to 34,800 cases in 2019 (HIV.gov, 2022). HIV is a virus that enters the body through the anogenital mucosa or by binding to dendritic cells found in the cervicovaginal epithelium as well as in the tonsils and adenoids. This means HIV can be transmitted through anal-genital, genital-genital, or oral-genital sex (Sax, 2022a). HIV can also be spread through blood and specific body fluids, including breast milk (WHO, 2023). HIV-infected cells in the body fuse with CD4+ T cells, which then spread the virus. During initial infection, the patient has a large number of CD4+ T cells and no HIV immune response, leading to rapid viral replication. After the primary infection, the patient develops antibodies against HIV antigens, and seroconversion occurs. As the virus stabilizes, a viral set point level is reached. This is variable in patients who are not on treatment, but for patients on treatment, the viral load can remain low. Patients then enter the phase of chronic HIV without AIDS. Without treatment, the patient will usually progress to AIDS within 5 to 10 years. However, with treatment, patients with HIV can often have a near-normal lifespan (Wood, 2023). AIDS is the outcome of chronic HIV infection with a consequent depletion of CD4 cells. AIDS is defined as a CD4 count < 200 cells/microL or the presence of any AIDS-defining conditions, which include the following: - bacterial infections, multiple or recurrent - candidiasis of bronchi, trachea, or lungs - candidiasis of esophagus - cervical cancer, invasive - coccidioidomycosis, disseminated or extrapulmonary - cryptococcosis, extrapulmonary - cryptosporidiosis, chronic intestinal, > 1 month - cytomegalovirus disease (other than liver, spleen, or nodes), onset at age >1 month - cytomegalovirus retinitis - encephalopathy, HIV related - herpes simplex—chronic ulcers (>1 month) or bronchitis, pneumonitis, or esophagitis, onset at age >1 month - histoplasmosis, disseminated or extrapulmonary - cystoisosporiasis (formerly known as isosporiasis) chronic intestinal (>1 month) - Kaposi sarcoma - lymphoma, Burkitt - lymphoma, immunoblastic - lymphoma, primary, of brain - Mycobacterium avium complex or Mycobacterium kansasii , disseminated or extrapulmonary - Mycobacterium tuberculosis of any site - Mycobacterium , other species, disseminated or extrapulmonary - Pneumocystis jirovecii pneumonia - pneumonia, recurrent - progressive multifocal leukoencephalopathy - Salmonella septicemia, recurrent - toxoplasmosis of brain, onset at age >1 month - wasting syndrome attributed to HIV (Wood, 2023) Screening and Diagnosis Patients at higher risk for HIV acquisition, including sex workers and AMAB persons who have sex with others AMAB, should be screened for HIV at least annually. Anyone seeking testing for another STI should also be tested for HIV. All pregnant persons should be screened for HIV as well. Written consent is not needed, and the CDC recommends the opt-out process for testing so that all pregnant persons are tested, unless they decline. Testing rates have been shown to be higher with this method. (CDC, 2021a). Testing for HIV requires a blood sample. Initial positive results should be confirmed using the supplemental HIV-1/HIV-2 antibody differentiation. Any rapid positive results should also be followed up with RNA testing (CDC, 2021a). Management and Treatment HIV and AIDS are reportable conditions in every state in the United States. Reporting should be done by the provider or lab according to state and local mandates. These reports are confidential (CDC, 2021a). Early detection and treatment of HIV can improve outcomes and reduce new cases, so all sex partners and needle-sharing partners should be notified as soon as possible (CDC, 2021a). Antiretroviral therapy (ART) consists of medications that suppress HIV. They should be given during the acute phase to decrease severity and transmission (CDC, 2021a). ART should be administered to all HIV-positive patients, regardless of the severity of the disease. ART has been proven to reduce AIDS and non-AIDS morbidity and mortality. ART is effective at suppressing serum viral RNA levels and increasing CD4 levels, possibly to near-normal levels. Low viral levels are thought to reduce the risk of transmission. ART should be started as soon as possible and should be managed by a provider who is experienced with HIV management (Sax, 2022b). The ART should be chosen based on drug-resistance testing but will be a combination of medications. ART is continued indefinitely (Sax, 2022b). Pregnant patients should receive these combination treatments as well (ACOG, 2024). Currently, no vaccine exists to prevent HIV, but HIV preexposure prophylaxis ( PrEP ) is available. The daily oral antiretroviral PrEP is a medication that can reduce the rate of HIV acquisition, especially in those persons assigned male at birth who have intercourse with other persons assigned male at birth. All sexually active patients should be educated about PrEP because it is 99 percent effective in preventing HIV. PrEP is available as an oral therapy taken at home or an injectable therapy given in a clinic setting every 8 weeks. Compliance with taking the medication is important when deciding which treatment to use. Complications Early ART treatment can reduce the severity and chance of transmission of HIV. Patients without ART can have a large viral load and are highly infectious. These patients can also spread HIV perinatally if they are pregnant. Pregnant patients should be tested at the first prenatal visit and again in the third trimester. Knowing about a person’s positive HIV status can help to maintain that patient’s health and reduce the risk of transmission to the fetus by taking ART. Transmission to the fetus without ART is about 30 percent, but that risk is decreased to < 2 percent with ART and obstetric interventions (ACOG, 2024). A patient with HIV and a viral load of ≤ 1,000 copies/mL can wait for spontaneous labor and have a vaginal delivery without increased risk of transmission to the fetus. Patients with a viral load > 1,000 copies/mL should be offered an elective C-section at 38 weeks with intravenous zidovudine (Retrovir) given 3 hours preoperatively (ACOG, 2024). Ideally, this will take place before the onset of labor and rupture of membranes to reduce the risk of transmission to the fetus. Breast-feeding should be discussed with the provider. HIV can be transmitted through breast milk, but the risk is less than 1 percent with ART (HIV.gov, 2023). Breast-feeding may be necessary in countries without safe water sources. Getting treatments to people in these areas is important (WHO, 2023). If an HIV infection continues without ART, the patient’s CD4 cell count decreases. This causes the patient to become immunocompromised. Once the patient is immunocompromised, they can develop complications such as oropharyngeal or vulvovaginal candidiasis , seborrheic dermatitis, bacterial folliculitis, and methicillin-resistant Staphylococcus aureus (MRSA). Streptococcus pneumonia can also occur (Wood, 2023). The patient is at higher risk of other STIs. HIV can progress to acquired immunodeficiency syndrome (AIDS), which is defined as a CD4 cell count < 200 cells/microL or the presence of any AIDS-defining conditions. These conditions include, but are not limited to, bacterial infections, multiple or recurrent; cervical cancer; Pneumocystis jirovecii pneumonia; encephalopathy; Kaposi sarcoma; lymphomas; and wasting syndrome. Death will likely occur (Wood, 2023). Patient Education Patients with HIV infection who take antiretroviral therapy (ART) can suppress the virus to undetectable levels, which can reduce morbidity, increase lifespan, and prevent sexual transmission to others. Patients diagnosed with HIV should be sent to an HIV specialist and may also need counseling. Pregnant patients should be tested because treatment with ART can significantly decrease the risk of spread to the fetus (CDC, 2021a). Table 7.5 summarizes sexually transmitted infections caused by viruses. \| Disease \| Organism \| Signs and Symptoms \| Lab Diagnosis \| Treatment per CDC Guidelines \| \|---\|---\|---\|---\|---\| \| Human papillomavirus (HPV) \| 150 types of HPV: double-stranded DNA virus \| None, or may have genital warts or precancerous lesions \| HPV testing during cervical screening \| No treatment for virus \| \| Herpes simplex virus \| Viral infection HSV-1 or HSV-2 \| May have no symptoms or genital lesions \| HSV NAAT assay PCR serum Viral culture \| First episode: Acyclovir 400 mg orally 3 times/day for 7–10 days OR Famciclovir 250 mg orally 3 times/day for 7–10 days OR Valacyclovir 1 g orally 2 times/day for 7–10 days Recurrent HSV-2: Acyclovir 400 mg orally 2 times/day OR Valacyclovir 500 mg orally once a day OR Valacyclovir 1 g orally once a day OR Famciclovir 250 mg orally 2 times/day \| \| Hepatitis B \| Virus \| No symptoms to flu-like symptoms: anorexia, nausea, jaundice, right upper quadrant discomfort, fatigue \| Serologic testing \| None for acute HBV; immune globulin, for prevention, therapeutic agents used for treatment of chronic HBV \| \| Human immunodeficiency virus (HIV) \| Retrovirus \| Asymptomatic to viral syndrome including fever, malaise, lymphadenopathy, pharyngitis, arthritis, or rash \| HIV-1/2 antigen (Ag)/antibody (Ab) combination immunoassays, serum \| Antiretroviral treatment (ART) does not cure but does suppress the virus \|	12,987	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Nursing/Maternal-Newborn_Nursing_(OpenStax)/07%3A_Commonly_Occurring_Reproductive_and_Genitourinary_System_Infections/7.02%3A_Sexually_Transmitted_Infections	libretexts	libretexts-0000.json.gz:40966	https://med.libretexts.org/Bookshelves/Nursing/Maternal-Newborn_Nursing_(OpenStax)/07%3A_Commonly_Occurring_Reproductive_and_Genitourinary_System_Infections/7.02%3A_Sexually_Transmitted_Infections
lveuEnAfuZV3ufP1	Bean culture in California / by G.W. Hendry ; with appendix on Composition of California varieties of beans / by M. E. Jaffa and F. W. Albro, and on Insect and other enemies of beans / by E. R. de Ong.	John W. Gilmore, Agronomy. Charles F. Shaw, Soil Technology. John W. Gregg, Landscape Gardening and Floriculture. Frederic T. Bioletti, Viticulture and Enology. Warren T. Clarke, Agricultural Extension. John S. Burd, Agricultural Chemistry. Charles B. Lipman, Soil Chemistry and Bacteriology. Clarence M. Haring, Veterinary Science and Bacteriology. Ernest B. Babcock, Genetics. Gordon H. True, Animal Husbandry. James T. Barrett, Plant Pathology. Fritz W. Woll, Animal Nutrition. Walter Mulford, Forestry. W. L. Howard, Pomology. IFrank Adams, Irrigation Investigations. C. L. Roadhouse, Dairy Industry. O. J. Kern, Agricultural Education. John E. Dougherty, Poultry Husbandry. S. S. Rogers, Olericulture. INTRODUCTION In 1917 California produced on 558,000 acres, 8,035,000 bushels of dry beans, constituting 44 per cent of the entire crop of the United States, and exceeding by 4.78 per cent the combined output of the five next important states, Michigan, New York, Colorado, New Mexico, and Arizona. Statistics for the production of these states and in California follow i1 VARIETIES Fifteen varieties of beans are staples on the California markets at the present time, many of which are unknown in the eastern bean districts. Some were introduced by the Spanish missionaries, some came through our early trade with the west coast of South America, and some came directly from the Indian tribes of Mexico. One is known to be of Oriental origin. These varieties not only differ from each other botanically, there being four genera and six distinct species represented, but they exhibit well-defined climatic preferences. Some thrive best in the warm interior districts, others in the cooler coast districts; some are sensitive BEAN CULTURE IN CALIFORNIA to the slightest frost, while others make their best growth during the winter months. Some germinate best in warm moist soils, some in cool moist soils, while others have the property of germinating in comparatively dry soils. Some ripen in 100 days while others under the same conditions require 160 days. The occurrence and duration of the blossoming period is equally variable and is a varietal characteristic (table 8). Some are incapable of setting pods during hot weather while others are similarly affected bv cool weather. Some exhibit a wide adaptability while others are narrowly circumscribed in their range for profitable production. Agricultural History. — The Lima is a native of South America, Avhere it is found growing as a wild perennial in the Amazon basin of Brazil. It was brought under cultivation in prehistoric times and well-preserved specimens have been discovered by Wittmack2 in the excavations of prehistoric dwellings at Ancon, Peru. Numerous introductions have been made into the United States from time to time, one of the first of which we have a record having been made by Captain John Harris, U. S. N., in 1824. He secured seed in Lima, the capitol of Peru, and grew it on his farm in Chester, New York, in 1825. Subsequently it came into general cultivation as a garden vegetable in the eastern states. It arrived in California at a much earlier date than has been generally recognized. H. McNally Company, of San Francisco, advertised Lima seed in the Alia in 1855. This is the first record we have of the Lima in California. As early as 1859 an unsigned article appeared in the California Culturists urging its culture as a garden vegetable, and it was used for this purpose for at least twenty years before its possibilities as a field crop became recognized. In 1872 Mr. Robert McAlister planted Limas on his ranch in the Carpinteria Valley, and they yielded abundantly without the use of poles. Mr. Henry Fish, a neighbor, then succeeded in interesting Dexter M. Ferry in the production of Lima beans for seed in that valley, and in 1875 Ferry sent the first selected seed to California to be grown under contract; and it is thought that the present strain has been developed from this stock. It success as a seed crop soon led to its used as a field crop, and in 1877 it made its first appearance on the California market as a commercial dry bean in competition with the Bayo, Pink, Small White, and other older field varieties. of a single plant selection made by Dozier Lewis in about 1888. Range in California. — The Lima is the most extensively grown, yet the most circumscribed in its range of any of the California bean .varieties. (Table 3, fig. 1.) Restricted portions of five small counties on the coast of southern California produce virtually the entire crop. The northern limit of profitable production is sharply defined and is in the vicinity of Tajignas on the coast of Santa Barbara County. North of Tajiguas it is entirely replaced, largely by the Small White and Blue Pod varieties. From Tajiguas south it is extensively grown in a narrow belt skirting the coast and within the fog belt through Ventura, Los Angeles, Orange, and San Diego Counties to Ensenada, Mexico. On the higher lands of this district, somewhat removed from the ameliorating influence of the sea, it is replaced by the Blackeye, Tepary. Lady Washington, Henderson Bush, and Pink varieties. The centers of greatest production are at Carpinteria in Santa Barbara County, at Ventura, Oxnard, and Santa Paula in Ventura County, at Sawtelle, Inglewood, Redondo, and Downey in Los Angeles County, and at Santa Margarita, and Oceanside in San Diego County. The Irvine Ranch alone, in Orange County, planted 18,500 acres of Limas in 1917. Adaptations. — The Lima is one of the most exacting in its requirements of all varieties, and grows to perfection in California only in the warm, humid climate of the southern coast region ; although tried again and again it has not succeeded in making a good impression in other parts of the state. In the coast districts north of Point Conception. all efforts to cultivate it have been abandoned because of its late maturity. In the Lompoc Valley plantings made in May have not ripened and dried sufficiently to thresh until the middle of December, 235 days from planting, and a planting made May 1, 1917, at Berkeley remained green until killed by frost in December, 230 days from planting (table 8). A planting made June 4, 1917 on the coast of Del Norte County in the extreme northern part of the state was frosted before the pods filled. These and numerous other instances point to the conclusion that the Lima requires more heat units to ripen than are Fig. 2.— Bean pods. Left, Blaekeye. Upper row, left to right: Horse Bean, Lima, Bayo, Red Kidney, French White, Cranberry. Lower row, left to right: Lady Washington, Spotted Red Mexican, Red Mexican, Pink, Blue Pod. Small White, Tepary, Garbanzo. provided in the coastal regions of central and northern California. All efforts to cultivate it as a field crop in the interior valleys of the state have been equally unsuccessful, but its failure here cannot be attributed to a lack of heat. The vines have grown with vigor and luxuriance, and blossoms have been produced in profusion, but the dry heat has allowed only a scant setting of pods. Of the numerous varieties tested at the University Farm at Davis, only the bush varieties have approached anything like a profitable yield, and similar observations have been made in the Turlock district, and in the Imperial Valley. (Table 5.) There are, however, limited areas where the climatic conditions approach those of the Lima belt of southern California, and where the Lima may be grown with moderate success. At Clarksburg, Yolo County, in 1917 a yield of 1577 pounds per acre was obtained, but the quality of the product did not compare favorably with that grown in the more genial climate of southern California. It has also been grown with indifferent success on Grizzly Island and in other parts of the Stockton delta. Utilization. — Dry Lima beans grown in Southern California are a staple on the markets in all parts of the United States and Canada. They are also used in both the dry and green state for canning. Agricultural History. — The Pink bean is a native of South America and has been cultivated in the department of Rancagua, Chile, and known as the Rancagiiino frijol, as far back as we have records of that country. It has also been a favorite bean in the states of central Mexico where it is known as the frijol rosa, and where it has been cultivated since the time of the conquest. It is known as the Yura mon (White Man bean) by the Indians in northern Mexico, a circumstance suggesting its introduction in that country by the Spanish conquerors. It is at present the most extensively cultivated field bean in the southwestern part of the United States, and in California its production is exceeded only by that of the Lima. (Table 2.) In total quantity it constitutes about 6.6 per cent of the entire bean production of the United States. The exact date of its appearance in California is uncertain, but it was first quoted as a commercial product on the California market in The Alta in 1866. It has never been listed by eastern seedsmen, nor has it been grown in the eastern bean districts. A small seeded strain called the Small Pink is occasionally grown in California. Range in California. — The Pink Bean has the widest distribution of any of our varieties, although second to the Lima in point of total production. (Table 3, fig. 1.) It is prominent in all of our bean 296 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION districts and stands first in both the Sacramento Valley and the Stockton delta. Extensive plantings are also made in the bean districts of the San Joaquin Valley, the central coast counties and in southern California. On lands bordering the coast and under the immediate influence of the ocean it has not been as prolific or as extensively cultivated as some other varieties, but on the higher lands and in the smaller valleys from San Francisco to Oxnard, including the Half Moon Bay, Watsonville, Salinas, San Luis Obispo, Lompoc, Santa Maria, and the Oxnard districts, it has been the favorite and most generally cultivated variety. From Oxnard south, the Lima predominates on the coast, but on the higher lands the Pink is largely replaced by the Blackeye and to some extent by the Tepary and Henderson Bush. Scattered plantings in smaller acreages are also reported from the Mattole Valley in Humboldt County, from the Owens Valley in Inyo County, the Imperial Valley, from Blythe in eastern Riverside County, the delta of the Kaweah River and the Tulare Lake district in Kings and Tulare Counties. Adaptations. — The Pink is at its best on good bottom land, but with irrigation and late planting is capable of yielding moderately on the drier uplands, under conditions too difficult for such varieties as the Large Lima, Small White, Blue Pod, Bayo or Cranberry, although it cannot compete with either the Blackeye or Tepary under conditions of extreme heat and drouth. This general relationship is confirmed by experiments at Davis, Turlock, Fresno, and the Imperial Valley. In the coast districts of northern and central California it vields well, but is often surpassed by other varieties. It is one of the most reliable, and is at the same time the most extensively cultivated variety in the island districts of the lower Sacramento River, and in the Stockton delta. Here it is rarely damaged by hot weather, and ripens on moist subirrigated soils where many other varieties grow later in the season. Utilization. — The southwest generally is the principal market for California-grown Pink beans. The Mexican population of Arizona, New Mexico, Texas, southern California and Mexico, prefer them to the white varieties. A small portion of the crop always goes to the southern states, especially Virginia, Louisiana, and Maryland; and it is being received more favorably each year in the middle western markets, especially at Chicago, Cleveland, Kansas City, St. Louis, St. Joseph, Omaha, and Salt Lake City. Its acceptance on the east- crn markets is of comparatively recent date, New York and Baltimore having taken small lots in 1916. Since the war it has been used by the eastern canning trade as a substitute for the Red Kidney, in the preparation of Chile con carne. Fig. 3. — (1) Bean land should be plowed deep in the fall. (2) It should remain rough until moist enough to pulverize. (3) It should be reduced with a heavy roller. (4) The crust should be broken as often as formed during the winter. (5) The chisel is an efficient implement for winter working. (6) The cyclone destroys Aveeds and maintains a shallow mulch. (7) The cyclone should be used frequently from the close of the rainy season until planting time. (8) The knife cultivator should be used for the later cultivations. (Photos by the Ventura Implement Co.) of California. Agricultural History. — The Small White is an old and deservedly esteemed Variety in the eastern United States, where it has been so long in cultivation without any distinct records to guide us to its origin that very little of its early history is known. Carlos Manriquez Eivera, director of the agricultural experiment station at Santiago, Chile, has identified California-grown Small White beans as being identical with the variety Coscorron Chico, which is considered a native of Chile. All other available evidence points to South America as the original source of the seed, but as it is practically unknown in Mexico, it probably did not come to the United States through that country. Wickson^ reports that it was brought to California from New York as far back as 1852, but the first record which we have of it as a California-grown product is in a market quotation appearing in the San Francisco Herald for September 16, 1855, in which it is reported that 27 sacks of California White beans sold for 8 cents per pound. The first mention of beans of any kind in a California newspaper, probably occurred in the Alta on November 1, 1849, in which in a statement of the current wholesale prices prepared by Woodworth and Norris, American bean in contradistinction to Chile (imported beans), are quoted at from $10 to $12 per barrel. These American beans were doubtless imported from the eastern United States and were in all probability Small White beans, for the name American beans disappeared from the market quotations during the following years and the name ' ' Small White ' ' appeared in its stead. Range in California. — The cultivation of the Small White bean is virtually limited to the coastal districts of central and southern California. (Table 3, fig. 1.) It is grown in every agricultural district on the west side of the coast range from San Francisco to San Diego, but is most abundantly produced in the Pajaro and Salinas valleys, where it equals about the total production of all other varieties. Formerly it was the leading variety in the Lompoc, Santa Maria, San Luis Obispo, and Arroyo Grande districts, but it has now been largely superseded in these places by its near relative, the Blue Pod. In like manner it is yielding ground each year to the Blue Pod in all other parts of its territory. It occupied about 65 per cent of the total bean acreage in the Salinas Valley in 1917, but is here limited to a small strip of the valley iioor extending about eight miles north and ten miles south of the town of Salinas. In all, there were approximately thirteen thousand acres in Monterey County in 1917. Small plantings were also reported in 1917 from the Mattole and Eel valleys in Hum- Owens Valley in Inyo County. Adaptations. — The Small White succeeds best in the cool humid climate of the coast region from San Francisco to Santa Barbara and outyielded all other (Phaseolus) varieties at Berkeley in 1917. (Table 5.) It is also well adapted to the coast districts north of San Francisco, but because of its later maturity is less reliable here than the Lady Washington. It succeeds moderately well in the cooler portions of the Stockton delta, but not so well as the Pink and the Lady Washington. It is sensitive to hot weather and all attempts to grow it at Davis, Turlock, Oakdale, Fresno, El Centro, and in fact in all hot situations, have resulted in failure. The seed not only germinates more readily in cooler soils than that of most other (Phaseolus) varieties, but the seedling plants are more thrifty and vigorous during cool weather. California-grown Small White beans seek the markets in all parts of the United States, but the principal destinations are New York, Boston, and the New England states. It is used more extensively in canning than any other California variety, and the army and navy prefer it to other kinds, a fact which accounts for its being called the Navy bean. Agricultural History. — In 1902, Pasqual Scolari, a Swiss farmer in the Lompoc Valley noticed that a certain plant in his field of Small White beans matured somewhat earlier in the season than its neighbors, and yielded an unusually large number of peculiarly tinted, purplish pods. He saved the seed from this solitary plant and grew it in his garden the following season, and found that all of the resulting plants resembled his original selection in earliness, pod color, and productiveness. By 1904 he had grown sufficient seed to plant about fifteen acres, from which he harvested nearly 400 sacks of beans. Eealizing the superiority of his seed to that of the ordinary Small White and wishing to profit by it exclusively, he requested the Southern Pacific Milling Company, to whom he disposed of his crop, not to sell his seed locally. Accordingly his crops for 1904, 1905, and 1906 were shipped to Portland, Maine. In 1907 Mr. Scolari left the valley, and Mr. A. C. Whittemore, agent for the Southern Pacific Milling Company, sold the Scolari crop to several of his customers for seed. It was at once favorably received and has continued to gain in public estimation until it has all but replaced the Small White variety in Santa Barbara County, and is rapidly extending its range northward. Occasional plants bearing blue pods and identical with the Blue-Pod variety, have always been, and still are, present in any field of Small White beans, but it remained for Pasqual Scolari to recognize the merits of the strain and propagate it. Range in California. — The Blue Pod is grown only in the coast districts of central and southern California. (Table 3, fig. 1.) The focus of production is in the Lompoc Valley, where it occupies fully 90 per cent of the total bean acreage, and gives way to the Pink only on the uplands. From Cambria on the coast of San Luis Obispo County, to Santa Barbara, including the Arroyo Grande, Santa Maria, Lompoc, and Los Alamos districts, there was an aggregate of over 45,000 acres planted to this variety in 1917. This constituted about 75 per cent of the total bean acreage for that territory. In the Monterey bay region there were about 1000 acres tributary to Watsonville, Santa Cruz and Soquel in 1917, and small plantings were also made southward in Ventura, Los Angeles, Orange and San Diego counties. Adaptations. — The Blue Pod is most like the Small White in its requirements. It prefers the cool humid coast climate and cannot be successfully grown in the hot interior districts. It differs from the Small White in that it blossoms slightly earlier in the season, produces a more open vine which cures more rapidly, and matures somewhat earlier in the fall. Its early maturity has been most marked in the later plantings, which ripened fully two weeks earlier than the Small White, when planted on July 2 at Berkeley. Early Maturity and rapid curing are properties of vital importance in the coast districts both north and south of San Francisco. Agricultural History. — The Lady Washington is in all probability a native of Chile and has been introduced from there into the United States upon several occasions. California-grown specimens of this variety have been identified by the Agronomy section of the Department of Industry and Public Works of Chile, as identical with the "Coscorron Medio" variety which is regarded as a native of that country. It was first introduced into the eastern United States, where it became a popular field variety, but is now little known there. It came to California with the tide of immigration in the fifties and appeared for the first time in the market reports in 1856. It did not become established at this time, however, and only an occasional lot reached the market until 1891, when it began to appear regularly. Range in California. — The principal centers of production for the Lady Washington, are Sutter and Colusa counties in the Sacramento Valley, Sacramento and San Joaquin counties tributary to the bay of San Francisco, and San Luis Obispo, Santa Barbara, and San Diego counties in southern California. (Table 3, fig. 1.) The most extensive plantings in 1917 were made in the Sutter Basin, including the area lying between the Feather and Sacramento rivers, from their junction on the south to Butte Slough on the north. There were in all about 16,000 acres of Lady Washington beans in this district in 1917. There were also about 2000 acres in the Mattole Valley of Humboldt County in 1917, this being the first large bean acreage ever grown on the coast north of San Francisco. It is also cultivated in all of the bean districts from San Francisco to San Diego; San Luis Obispo, Santa Barbara, and San Diego counties usually contributing about 2000 acres each. There were about 1000 acres in the Livingston district of Merced County in 1917, and small plantings were reported from Montague and Granada on the Shasta River in Siskiyou County. Adaptations. — The Lady Washington is less exacting than the Small White or the Lima, and may be grown under more adverse climatic conditions. It requires considerable humidity, but unlike the Small White tolerates moderately well the heat of the interior valleys. It is most productive on the lower Sacramento River and in the Stockton delta, but has been satisfactory on the bottom lands throughout the Sacramento Valley, and in the San Joaquin Valley as far south as Livingston. It does fairly well in the interior upland situations when irrigated and planted late (after June 10) but can not compete with the Blackeye or Tepary as a dry-land crop. It has proved unsatisfactory planted early without irrigation at Davis, Fresno, and El Centro, and in these hot climates is less productive than the Red Mexican and Pink varieties. As a coast bean it has much to recommend it, for it not only yields well but ripens earlier than the Small White, a quality especially desirable north of San Francisco. In the coast districts from San Francisco to Lompoc, it is slightly less productive than the Small White, but from Santa Barbara southward it stands the warmer climate somewhat better than the Small White. Utilization. — The Lady Washington is shipped principally to the markets of the middle western, northern, and eastern states. St. Louis, Kansas City, Omaha, Chicago, and New York have been the largest users, although the Gulf and south Atlantic states have taken it in limited quantities. It cannot be used for canning purposes because of its rapid disintegration in cooking. Agricultural History. — The Blackeye, like other varieties of cowpeas, has come to us from the Orient, where it is found grooving wild as an escape from cultivation, and where it has been used since ancient times as a human food. It was introduced into the eastern United States as far back as 1835,5 and since that time has come into general cultivation throughout the South Atlantic and Gulf States. It appeared in California at a comparatively recent date, the earliest occurrence of the name in our market reports being in the Alta in 1880, but during recent years it has gained rapidly in public estimation and has come to occupy an important place in the agriculture of the state. It is as yet little known in South America. Range in California. — The Blackeye is grown throughout the interior agricultural regions of California, occupying for the most part, lands which are too hot, and too dry, for the successful cultivation of other varieties. (Table 3, fig. 1.) It is sensitive to cool weather and cannot be grown in the coast regions of central and northern California; but from Oxnard to San Diego it occupies the major portion of the higher bean land, which is too dry for Limas. From Oxnard north on similar lands it is replaced by the Pink, for climatic reasons. The most extensive plantings in 1917 occurred in the territory from Modesto to Livingston, where it is estimated that there were approximately 12,000 acres. Extensive plantings were also made near Riverside, Arlington, Corona, Perris, Hemet, San Jacinto, and Blythe in Riverside County; near Ventura, Moorpark, and Fillmore, in Ventura County; near La Habra, Fullerton, Anaheim, Orange, Santa Ana, and San Juan Capistrano in Orange County ; in the San Fernando Valley in Los Angeles County; near Salida, Modesto, Ceres, Keys, Turlock, Empire, Hughson, and Denair in Stanislaus County; near Manteca and Ripon in San Joaquin County, and near Colusa in Colusa County. Smaller acreages were also grown throughout the Sacramento Valley and at various places in southern California as well as in the Santa Clara, San Benito, Antelope, and Imperial valleys. Adaptations. — The Blackeye thrives best where continuously hot weather enables it to carry on a perfect and rapid growth. The blossoms are not so sensitive to dry haat as those of the common bean varieties, and the hottest, driest weather of the interior is but slight impediment to the setting of pods. It lias repeatedly demonstrated its tolerance for hot climates by averaging 786 pounds of seed per acre at Davis in six trials without irrigation ; and has frequently yielded three times this amount under similar circumstances. Moreover, it has given equally good returns in upland situations throughout the interior districts both in central and southern California. In its ability to yield under droughty conditions in experiments at Davis, Turlock, Oakdale, Swingle, Paso Robles, Fresno, Riverside, and El Centro, it has been equalled only by the Tepary. Three experimental plantings at Kearney Park, Fresno County, in 1917, averaged 1801 pounds of seed per acre. It matures in from 90 to 110 days in hot climates (table 8) and is therefore especially useful as a catch crop or as a late summer crop following grain hay. With irrigation in the interior districts, planted as late as July 10 it will mature before the autumn rains. The Blackeye is the variety most sensitive to cool weather, and reacts unfavorably to the coastal climate of central and northern California. In such situations it fails to mature, produces sickly dwarfed plants, and drops its flowers and flower buds without setting pods. A planting made at Berkeley May 1, 1917, was killed by frost December 15, 230 days from planting and during the period had failed to ripen a single pod. (Table 8.) Similar results were obtained on the coast at Santa Cruz, Ignacio, and Smith River. At Smith River in Del Norte County a planting made May 25 was green and had set no pods when killed by frost November 5. On the coast of southern California, however, it does much better, but even here it grows more satisfactorily in the warmer situations at some distance from the sea. It yields well in the Stockton delta but here also shows a preference for the warmer portions of the region. At high elevations in the mountains the climate is too cool for it. It is seldom attempted on the better river bottom lands, chiefly because other more valuable varieties are equally prolific in such situations, and because on moist soils it matures late in the season, and produces excessively long runners which interfere seriously with harvesting. Utilization. — The primary markets for California Blackeye beans have been in the southern states, especially at El Paso and Norfolk. Kansas City and New York have also taken large shipments in the past ; although those going to New York have been largely reshipped to Cuba, Porto Rico, and South America. Those going to the southern markets come into competition with the home-grown product, and occasionally with shipments from southern Europe, but California Blackeyes are reported as being of superior quality. It is used as a human food both in the dry and green state and supplies the demand for a cheap bean. Small quantities have also been used for the adulteration of coffee. It has been utilized to a limited extent as a summer orchard green-manure crop, and as a companion crop with corn to provide forage, but for these latter uses, other cowpea varieties, such as the Whipporwill, Miller, Brabham and Brown Crowder, which make a much heavier vine growth, are generally more satisfactorj^. Agricultural History. — The Cranberry is similar to the Araucano bean of Chile, and all available evidence points to the conclusion that it was first introduced from there into the eastern United States. It has been listed by eastern seedsmen since I8606 and is one of the five most popular garden pole beans in the United States at the present time. We are indebted to California, however, for our knowledge of it as a field crop. Although grown here for many years as a garden vegetable it was not until 1907 that it reached our terminal markets in quantity, and became one of our staple dry bean varieties. In 1917 there were about 150,000 sacks marketed in California. Comparisons in the field at Davis during the past season have proved it to be identical with the garden snap bean variously known in the eastern states as London Horticultural Pole, Cranberry Pole, Housewives ' Delight, Scipio Pole and Wrens' Egg. Range in California. — The production of the Cranberry bean in California has been limited to the bottom lands of the Sacramento River, from Sacramento to Antioch, and has focused in the Pierson reclamation district near Courtland. (Table 3, fig. 1.) The largest acreages in 1917 were on Ryer, Grand, Brannan, Twitchell, and Sherman Islands; but small acreages were planted on the Feather River south of Yuba City, near Salinas in Monterey County, in Lake County, and on the. Klamath River in Siskiyou County. It is also grown for the eastern seed trade in the vicinity of Arroyo Grande in San Luis Obispo County. Adaptations. — The Cranberry is well adapted to the rich bottom lands of the lower Sacramento River and to the coast districts of central and southern California, but is sensitive to extreme heat and has proved a complete failure in interior upland situations. Tests at Davis, Fresno, and El Centro confirm the opinion generally entertained that it cannot be grown in upland situations. It has a small delicate root system and matures late in the season (table 8), which are further reasons for growing it on finely prepared soils well supplied with moisture. Moreover, the seed coat is thick, preventing the rapid absorption of moisture which makes germination uncertain in dry soils. Utilization. — California Cranberry beans are marketed almost entirely in the eastern states. The largest shipments have gone to Chicago, Cleveland, Pittsburg, Boston, and New York, for distribution to the eastern mining districts. In large measure it owes it recent popularity to the fact that it has replaced a similar variety, formerly imported from Austria, especially for the eastern mining trade. Agricultural History. — The word bayo is a Spanish descriptive adjective and refers to the bay or chestnut color of the bean. Bayou is an English noun meaning a body of stagnant "water, and has been incorrectly applied as a name to this variety. The Bayo is a native of Chile and was brought to California in the cargoes of the first trading vessels. It was first quoted in this state as a market product under the name Chile in The Alia for July 19, 1850, and as early as 1853 was known as the Chile Bayo, probably to distinguish it from the California-grown Bayo. Since 1853 it has been a staple. During the gold rush in the early fifties, it was imported from Chile in large quantities and has retained its popularity to the present day in the mining camps throughout the Pacific Coast region, including Alaska. A small seeded strain known as the Bayo Chico, was formerly imported from Chile and cultivated in California. The Imported or Manchurian Bayo is a speckled bean coming from the Orient but is not grown in California. Range in California. — The Bayo is produced in largest quantities on the Sacramento River, from Antioch on the south, to Marysville on the north, but extends as far northward as Redding in Shasta County and westward in scattered plantings on the bottom lands 'of the Feather, Yuba, Bear, American, Cosumnes. and Mokelumne rivers and their tributaries. (Table 3, fig. 1.) It has been the favorite variety in the mining districts of Nevada, Placer, El Dorado, and Amador counties, but the total production there has been small. Sporadic plantings are also made on the Klamath River in Siskiyou County and at other places in northern California. Formerly it was grown extensively in the Lompoc Valley, as much as 7000 sacks having been produced there in 1913, but it has now been superseded there by other varieties. It is also well known and generally cultivated in parts of northern Sonora, in Mexico, and in Arizona and New Mexico. Adaptations. — The Bayo has been cultivated most successfully in the island districts of the lower Sacramento River, in the Stockton Fig. 4. — (1) A two-row, sprocket drop, hoe furrow opener, planter. (2) A four-row, sprocket drop, press wheel planter. (3) Six two-row plate planters, planting 75 acres in 10 hours. (4) Side hill planter. (5) Drop-side wagon for hauling beans. (6) Net for unloading wagon. (7) A modern bean cutter equipped with adjustable knives, rollers, and auxiliary wheels. (8) A small portable threshing machine (Photos Nos. 1, 2, 5, 6, 7, and 8 by Ventura Implement Co.) delta, and on the coast of southern California, but its late maturity limits its usefulness in the central and northern California Coast districts. It has been tested on the drier uplands at various places in the Sacramento, San Joaquin, and Imperial Valleys, as well as in the interior of southern California, but has always failed in these Fig. 5. — A two-row, pivot axle cultivator. It may be adjusted to different width rows, and is equipped with shields and deep working shovels for the first cultivation. (Photo by International Harvester Co.) and second, because of its ready susceptibility to red spider attacks. Utilization. — The principal markets for the California Bayo have been in the mining districts of the Pacific Coast, although large shipments are made to Texas, Arizona, and New Mexico to supply the Mexican trade. Recently markets have been established in the mining districts of the east and middle west. pea, Madras gram. Agricultural History. — The Garbanzo is considered to be indigenous to western Asia, but has been cultivated since ancient times in Egypt, Greece, and Italy, and in comparatively recent times in India. Next to the cereals, it forms the largest part of the food of the peoples of India, northern Africa, and Spain, and is an important field crop in all South and Central American countries, as well as in the southwestern United States. It is a characteristic food of Latin peoples and has been carried by them to all parts of the world. It was introduced into California by the Spanish missionaries, whose records show that 8450 pounds were produced at the various missions in 1831. It has been cultivated to the present time and is now a staple crop in California. Range in California. — The largest acreage of Garbanzo beans is usually reported from reclamation district No. 70, south of the town of Meridian, lying in Sutter County, between the Sacramento River and the Marysville Buttes. There are usually about 2000 acres in this locality. Smaller acreages may be expected near Marysville and from Sacramento to Antioch, especially in the "Pocket" district near Freeport, and on Brannan, Ryer, and Sherman islands; but the recent expansion of the vegetable seed farms on the heavier soils in these latter districts has resulted in a considerable reduction of the Garbanzo acreage. (Table 3, fig. 1.) Adaptations. — In its ability to thrive under various climatic conditions the Garbanzo has evinced considerable adaptability, but has shown a preference for coast conditions. At Berkeley in 1917 it outyielded all other varieties except the Horse bean. (Table 5.) It has also yielded well in upland situations, in the interior districts of both northern and southern California, and is little affected by hot weather at blossoming time. Moreover, the seed reared in the drier districts are larger and of superior quality to those produced on the coast (frontispiece). It is hardy and is reported to have withstood temperatures of 13° F. without injury. It is customarily planted in February and March, but on well-drained land may be planted during Practically the entire Garbanzo crop of California was a failure in 1917, apparently due to the seasonal conditions. In many cases there was a failure to obtain a stand and in others the plants died in the seedling1 stage, showing a discoloration on the root. A wellaerated, well-drained soil is absolutely essential for the germination of Garbanzo seed. Plantings made at Berkeley May 17, 1917, in a wet soil, after irrigation, failed to produce a single plant, while the same seed gave a perfect stand when planted after the soil had dried somewhat. Plantings at Davis April 13, 1917, in a cold, wet soil gave a poor stand and nearly all plants died before setting pods, while the same seed gave a perfect stand nearby when planted May 30 and again on July 5. The diseased plants from these and from several other places in the Sacramento Valley were found to be infected with a root rot (Rhizoctonia) , the unusual destructiveness of which during the past season is to be attributed to the cold late spring which reduced the vigor and resistance of the young plants. Utilization. — California Garbanzos are shipped to all parts of the United States wherever there is a Latin population. They go principally into the southwest and to the Gulf states, whence many are shipped into Mexico, Cuba, and to South and Central America. New York takes a great many, part of which are consumed in the Italian districts, the remainder being shipped to southern Europe. The leaves while green are viscid with a secretion containing oxalic, acetic, and malic acids. In India this is collected by placing cloths over the growing plants at night and is utilized in the preparation of vinegar and beverages of various kinds. This acid secretion has been reported as poisonous to stock when the plants are fed green. Agricultural History. — The Red Mexican was one of the first bean varieties to be cultivated in California, and came to us from the Indian tribes of northern Mexico, where it is known as the Rojo bean. It was first quoted on the California market as the California Red in 1855, and later was known simply as the Red until about 1900, when the name Red Mexican was appropriately applied to it. It is unknown in Chile where so many of our varieties are common. In California its production has never equalled that of the Pink, although it is increasing in popularity and, wherever grown, its reputation as a dry-land crop has been fully sustained. Range in California. — Excepting southern California, the Red Mexican is grown in the same general territory as the Pink. (Table 3, fig. 1.). In the Sacramento Valley and in the Stockton delta its production is comparatively limited, but in the San Joaquin Valley, particularly in the northern portion, it now occupies a larger acreage than the Pink. About 40 per cent of the total bean acreage in San Joaquin County, exclusive of the delta region, was in Red Mexican beans in 1916, and in the Turlock and Modesto districts it occupied approximately 20 per cent of the total bean acreage. In the coast sections of San Mateo, Santa Cruz, Monterey and San Luis Obispo counties the plantings are numerous but small, and in southern California it is rarely grown. The principal areas of origin are tributary to Stockton, Turlock, Modesto, Livingston, and Marysville. Smaller acreages are reported from Humboldt, Lake, Shasta, and San Benito counties. Adaptations. — In field requirements, as in appearance, it is most like the Pink, it being impossible to distinguish between these two varieties in the field until the seeds start to color. It thrives best on the rich river bottom lands or in proximity to the coast, but is capable of yielding moderately in situations too hot for the more sensitive varieties, such as the Lima, Small White, Cranberry, and Bayo. It cannot be recommended as a safe crop for the difficult climate of Davis, Fresno, or El Centro, but even in these places it surpasses the Pink, and with irrigation and late planting has occasionally yielded well. It is, however, less dependent upon irrigation than the Pink. Generally speaking, it is the most satisfactory of our varieties for hot localities, excepting the Tepary, the Blackeye, and possibly the Henderson Bush, and has been responsible for a considerable extension of what was generally regarded as Pink bean land. In variety tests on the coast of northern and central California it has been one of the highest yielding varieties and has in nearly every case exceeded the Pink in yield. (Table 5.) In these districts it has a further advantage over the Pink, in that it is less subject to mildew damage. It is gaining in public estimation in California, largely at the expense of the Pink. Utilization. — The Havana market takes the Red Mexican in preference to all other varieties, and many shipments are made there directly from California. Large shipments are also made to the southwest and to Mexico, also to South America via the port of New Orleans. It is very little known on the eastern markets and appeared there in quantity for the first time in 1916. Agricultural History. — The Bed Kidney has been a standard field bean in the eastern states since 1857, Avhere it is second in importance to the Navy bean. Its total production in 1917 constituted about 6.8 per cent of the total bean crop of the United States. There are no records to show at what time it was introduced into California, but its extensive use as a field crop is of comparatively recent date, for it does not appear in our market quotations until the early nineties. Range in California. — The Red Kidney is grown most extensively on the Sacramento River bottom lands, tributary to Marysville, but extends northward to Anderson, in Shasta County. In the Sutter Basin south of Marysville it occupied approximately 2y2 per cent of the total bean acreage in 1917, or about 1000 acres. From Sacramento to Rio Vista, and in the Stockton delta, there is a small production, but it has not been grown much in the San Joaquin Valley excepting for a small local production on the lower Merced River bottoms, and near Denair in Stanislaus County. Small scattered plantings have been reported from Ukiah in Mendocino County, Upper Lake, Tule Lake, and Big Valley in Lake County; Placer County, San Benito County, Half Moon Bay, San Mateo County, Pajaro Valley, Santa Cruz County, Salinas Valley, Monterey County, Gilroy, Santa Clara County, Round and Owens valleys, Inyo County, and on the coast of Ventura and Santa Barbara counties. (Table 3, Adaptations. — The Red Kidney is adapted to the coast sections of northern, central and southern California, and to the mountain valleys in eastern and northern California. With late planting it thrives on the bottom lands of the Sacramento River, but in the hotter and morearid climates of the uplands it cannot compete with the Red Mexican or Pink. Although not a high-yielding variety it offers several advantages not possessed in the same degree by any of the other varieties under discussion. It is the earliest maturing variety in the coast sections, and only the Tepary, Blackeye and Garbanzo are earlier in the interior. (Table 8.) Because of this characteristic it lends itself to the short seasons of northern and eastern California, and is valuable on overflow lands which must be planted late in the summer. On moist lands, it does not prolong its growth as many varieties do, and because of its bushlike habit, the pods are held free of the ground and there is little loss through staining and discoloration on such lands. Its small erect plants permit of its being planted in narrow rows and hand cultivated, a fact which has been recognized by our Oriental farmers in increasing yields. When mature it sheds its leaves before the pods are ripe, resulting in a more rapid curing and being of special advantage during rainy seasons and in foggy districts. Utilization. — The Red Kidney is extensively grown in the eastern bean districts, and the California products find a ready market there, but is especially liked in Boston. It is in demand in Cuba and Porto Rico, and a considerable portion of the California crop reaches those markets through the port of New Orleans. In the past it has been a popular canning variety, but the recent advance in price has resulted in the partial substitution of other colored beans for this purpose. Agricultural History. — The White Tepary is of Mexican origin, the name ' ' Tepary ' ; having been given it by the Tarahumara Indians of Chihuahua. Many forms resembling it have been found growing wild in Arizona and Mexico, and have been described by botanists as far back as 1849. Numerous varieties had also been domesticated by the Indians before the advent of white men and are thought to have been a heritage from an ancient Aztec civilization. Forbes and Freeman7 collected seventy-one varieties of beans among the Indian tribes of Arizona and Mexico in 1910, forty-seven of which were distinct varieties of teparies. In 1912 Freeman7 first called attention to its possibilities as a drouthresistant crop for the arid southwest, and the progress which it has made in public estimation since that time is remarkable. Prior to 1914 it was unknown on the California market, although it had been grown experimentally in the state a year or two previously. Range in California. — The White Tepary is grown throughout the central valley of California, from Anderson to Bakersfield, and in the arable portions of southern California. (Table 3, fig. 1.) It cannot be grown successfully in the coast districts of central or northern California, nor at mountain elevations. The most extensive plantings in 1917 were in the Turlock and Modesto districts of Stanislaus County, and in San Joaquin, Merced, Los Angeles, Riverside, Glenn, and Butte counties. Smaller plantings were made in the Santa Clara, Upper Salinas, San Benito, Antelope, Imperial, and Palo Verde valleys, also near Blythe on the Colorado River, near Ontario in San Bernardino County, and near Thermal in central Riverside County. triets, and for dry soils and seasons. Several varieties of Teparies have been tested at Davis for a number of years and have surpassed all other varieties including the Blackeye in yield. (Table 5.) In fourteen trials, the Yellow Tepary without irrigation averaged 1203 pounds per acre, against 540 for the White Tepary in three trials. These are profitable yields but might be greatly increased by irrigation. Equally favorable returns have been obtained at Turlock, Riverside, El Centro, and Fresno. At the last mentioned place in 1917 four separate plantings of White Teparies without irrigation, but on subirrigated land, yielded 4212, 3516, 3252 and 2305 pounds per acre, respectively. The Tepary grows indifferently in the cool coast climate of central and northern California, also at high elevations ; but does better than the Blackeye in such situations. At Berkeley in 1917 a planting on May 1 was too green to thresh in December, 160 days from planting, while at Davis it matures in from 90 to 110 days, and if moisture is available may be planted as late as July 20 and yet mature. (Table 8.) By careful management, it is possible to take two crops in a season from the same land. The seed germinates quickly in soils of low moisture content, but rots quickly in cold moist soils. The pods shatter freely when ripe and special precautions should be taken against this at harvest time Iii a field of White Teparies individual plants show a range of two weeks in time of ripening, vary greatly in habit of growth, size and shape of seed, and other characteristics. Several of these forms are now being propagated as pure lines at the University Farm at Davis. Utilization.— The Tepary has not been recognized as a commercial product until the last three or four years, and there has been much difficulty in securing its acceptance on any of the markets of the east or west. Consumers have objected to its flavor and odor when cooked. One carload which went to Washington, D. C, could not be sold, and the dissatisfied dealer attempted to resell it at a loss. Similar experiences have been reported from other parts of the country. It has been unfavorably received in San Francisco, and cannot be sold even to the cheaper restaurant trade. Special methods of cooking designed to eliminate the strong flavor are now being proposed, and it is hoped that a staple market may in this way be established. See California Circular, "Cooking the Tepary Bean," September, 1917. Agricultural History. — The Horse Bean has been known and used as an article of food as long as our records of the pa^t serve us. It is mentioned in the Scripturess (Sam. XVII, 28, 1023 B.C., and Ezek. IV, 9, 595 B.C.) and we find mention of it throughout the literature of Egypt, Greece, and Rome. Further evidence of the antiquity of its cultivation is shown by the mention made of it in the twelfth chapter of the eighteenth book of Pliny, and by the fact that it was found by Virchow in the excavations at Troy.9 It was probably introduced into Spain and England by the Romans and came to America with the colonists. It arrived in Califorian via South America with the Spanish missionaries, and we have records of its cultivation in Alameda County by the Portuguese in 1887, and by General Eli Murray in the Valley of the Palms, San Diego County, in 1889, but it does not appear in our market quotations until 1894. Range in California. — The Horse Bean is cultivated most extensively in the San Francisco bay region, and in the central California coast district. (Table 3, fig. 1.) The principal centers for its production are at Morro, Oceano, Cayucas, Cambria, Pescadero, Watsonville, and Half Moon Bay. It is also grown sporadically in the Sacramento Valle3r, principally near Marysville, Central House, Germantown, West Sacramento, reclamation district No. 744, and in the use are made throughout California. Adaptations. — There are numerous varieties of Horse Beans, probably over 100 occurring in different parts of the world. In England there are at least nine varieties in common use. The different kinds require different climatic conditions, are cultivated under different circumstances, and for different uses. In California only one variety, the Windsor, is well known. This is essentially a cool climate crop, is robust and vigorous, and grows to perfection in the coastal sections of central and northern California. It is not injured, even when in blossom, by ordinary freezing weather, and thrives as a winter or early spring crop. It is extremely sensitive to hot weather and may not be grown as a summer crop in the interior districts. It is usually planted from February to March, but has yielded best when planted from October to January. Plantings at Davis in May and June have even failed to germinate. In the cooler coast districts it may be planted later, and frequently is planted from March to May in order to reduce weevil infestation, but if planted after June 1 it is subject to rain damage at harvest time. Plantings at Berkeley July 2 matured late in December, but others planted May 1 ripened about September 30. (Table 8.) It has been successfully employed as a winter crop in a double cropping system with summer beans, occupying the land from November to June, but it has only been possible to use it in this way on well-drained irrigated lands. Utilization. — From 30 to 40 per cent of the California Horse-bean crop is used as a stock feed within the state, the remainder is shipped to New York and other large eastern cities where it is used as an esculent principally by the poorer class Italian and Jewish peoples. As a stock food it is generally fed with hay, in the finishing of cattle. A small part of the crop is ground and used in the manufacture of prepared poultry foods, and occasionally the ripe seed is roasted and eaten like peanuts, or ground and mixed with coffee. The soft immature seed is palatable and is marketed as a winter vegetable. The entire plant may be cut green and siloed, or cured and fed as hay. The straw, however, is coarse and has little feeding value. It has been employed both as a green manure and as an orchard cover crop, but because of the large amount of seed required (table 9) is an expensive crop for such use. It has fallen into comparative disrepute in California of late because of the stringency of the Federal Food and Drugs Act, which classes weevil-infested Horse Beans as adulterated food, and prohibits their shipment in interstate commerce for use as human food. The numerous confiscations in transit under this regulation have occasioned losses to the shippers, kept the price down, and retarded the expansion of the acreage. Agricultural History. — The Henderson Bush was the first of the bush lima varieties, and was developed from a single plant found in the vicinity of Lynchburg, Virginia, about 1883. In 1885 it passed into the possession of T. W. Wood and Sons who sold the entire stock in 1887 to Peter Henderson and Company.10 Shortly after this it was sent to California to be grown for seed but has now come to occupy an important place as a field corp in the state. Range in California. — The Henderson Bush is more tolerant of heat than the Large Lima and is grown on the higher lands at some distance from the coast in southern California. The principal areas of origin are : The San Fernando Valley in Los Angeles County, where there were about 10,000 acres in 1917, Carpinteria Valley, Perris, Beaumont, Santa Paula, Anaheim, Santa Ana, and Fullerton. There were also scattered plantings throughout the small coast valleys of San Diego County. (Table 3, fig. 1.) Adaptations. — The Henderson Bush yields best in the coast climate of southern California, but gives satisfactory returns in the more difficult interior climates. It is not so tolerant of extreme heat as the Blackeye or Tepary, but compares favorably with the Red Mexican and Pink, and has produced fair crops in the Sacramento and Imperial valleys, and in the interior of southern California. It is less affected by cool weather than the Large Lima and ripens much earlier than the latter in the coast districts of central California. Utilization. — The Henderson Bush has been chiefly a canning variety but has been marketed as a dry bean in all parts of the United States. It is also popular as a garden vegetable in the eastern states where it is used as a green shelled bean. Agricultural History. — The French White bean was introduced into California in 1902 by Mr. Peter Delpy, of Vista, San Diego County, who obtained the seed from Mr. Clement Eabante, Department of Ariege, Canton of Lavelanet in southern France. Samples have been submitted to Vilmorin Andrieux and Co. of Paris and it is thought by them to be identical with the French variety, "Four to Four." Range in California. — The production of the French White has been confined thus far to the coast of Orange and San Diego counties, and has centered about Vista, Encinitas, and Cerento in San Diego County, but the total planting in 1917 did not exceed 1000 acres. Adaptations. — The French White has not been tested sufficiently under different conditions to determine its range of usefulness. It succeeds well in western San Diego County and in a small planting at Berkeley in 1917 did moderately well. It resembles very closely the Lady Washington but the vines are slightly larger, more vigorous, and upright. The leaves are smoother and slightly smaller; it blossoms somewhat longer, ripens earlier, and the pods are more fleshy and practically stringless. Utilization, — It has not been grown long enough or in sufficient quantity to have an established market, but as yet no trade distinction has been made between it and the Lady Washington. Agricultural History. — The Spotted Eed Mexican or Pinto, bean, not the same variety as the Colorado Pinto, was first grown in California by Mr. Arthur Canavan of Stockton, who obtained the seed from Mexican travelers in 1905. Several years later Mr. J. M. Dial obtained seed from Mr. Canavan and planted it on the Stanislaus Eiver bottoms, where it has been grown in a small way to the present time. Its striking appearance has attracted much atention and experimental plantings have been made by farmers throughout California. That it is in some way related to the Eed Mexican is indicated by its tendency to revert, always producing some typical Eed Mexican seed. Adaptations. — The plants are slightly larger and more vigorous than the Red Mexican, but in its requirements and yielding capacity under different conditions it resembles the Red Mexican more nearly than any other 'variety. Utilization. — The production has been insignificant compared to other varieties, amounting to only 50,000 pounds or one carload in 1917. The chief difficulty in the way of its production has been its low and uncertain market value. ADAPTATIONS OF BEANS Soil Requirements. — Any productive soil, properly handled, and favorably situated climatically, will produce beans. Adobes, loams, sands, and peats have all yielded satisfactory crops, but some are clearly more suitable than others. Beans are rarely attempted on the heaviest soils, owing to the difficulty of obtaining and maintaining a sufficiently fine tilth, and sandy soils when unirrigated, are equally objectionable, because of the difficulty of maintaining an adequate supply of moisture throughout the growing season. With some varietal differences, to which allusion is made later, beans are injuriously affected by both alkali and acid soils. The principal physical properties of an ideal bean soil are : a certain amount of tenacity and firmness to give it the requisite water-holding capacity ; a good depth so as to admit freely of the downward passage of the roots, and freedom from any surplus of water beyond that which such soils naturally contain. In general, beans thrive best on what are generally recognized as our best truck soils. Climatic Requirements. — With some notable exceptions previously mentioned, atmospheric heat and aridity are limiting factors in the production of beans, changes in climate often separating profitable from unprofitable bean land abruptly and independently of the nature of soil. The bean districts of the Sacramento River, the Salinas Valley, and the coast of central and southern California all afford excellent examples of such abrupt .changes. At Sacramento, representative of the Sacramento River district, the mean relative humidities11 at 5 a.m. for May, June, July and August are respectively 82, 78, 76, and 77; at San Luis Obispo, representative of the central coast district, they are correspondingly 82, 84, 87, and 88; and at San Diego, representative of the southern coast district, they are correspondingly 82, 84, 87, and 85 ; while at Fresno, Red Bluff, and Yuma, Arizona, representative of districts where common beans cannot be grown easily, the corresponding humidities are 74, 59, 50, and 54; 79, 59, 49, and 49 ; 55, 55, 61, and 65. Temperature is also a factor in the determination of distribution and variety adaptation. ALKALI TOLERANCE OF BEANS Most beans are more sensitive to alkali than wheat or barley, and should not be attempted when these crops have failed. Upon this point there is a general coincidence of opinion, referable in part to many futile and costly attempts to grow them on such lands, and in part to more carefully controlled laboratory and field experiments. In every important bean district of California, however, soils are to be found in which only low concentrations of alkali are present, and on which beans may be grown with varying degrees of success. On such lands the question of which variety will succeed best is extremely important, and may, in itself, outbalance all other considerations in the choice of a variety. Although no experiments of a decisive nature have as yet been performed to determine accurately this relationship, a recent preliminary greenhouse experiment at Berkeley points to the conclusion that there is a decided difference in the abilitv of our common bean varieties to grow on alkali soils, and that under the conditions of this experiment at least, it is possible to separate them into three fairly well-defined groups, based upon their alkali tolerance as follows : represent different botanical species than those in group 3. The varieties in group 1 not only grew in concentrations of alkali where other varieties failed to grow, but survived for longer periods, and were more thrifty in the lower concentrations. The varieties in group 2 lived longer in alkali solutions and were less affected by them than those in group 3. PREPARATION OF THE SOIL Unirrigated Lands. — Lands which receive neither sub nor surface irrigation are dependent upon the storage of winter rainfall for the growth of the crop during the summer, and the system of management applicable to such lands is based upon the principles of dry farming. Fall Flowing. — The first objects of such a system are to secure the greatest penetration of the winter rainfall and to reduce to a minimum the losses through evaporation and surface run off. This is best accomplished by plowing the land as deeply as possible, twelve to fourteen inches, immediately after harvest in the fall (fig. 3). Heavy soils treated in this manner will turn up in large lumps but under careful management may be reduced to a good tilth during the winter. Deep fall plowing, especially on soils which have not previously been worked deep, or in soils underlain by consolidated subsoils,, may advantageously be supplemented by sub-soiling to a depth of sixteen to eighteen inches. This is especially recommended as a measure to increase moisture penetration in the more arid districts. Winter Working. — During the winter the land should be worked in such manner that by spring it will be fine and well settled to the bottom of the furrow, yet protected by a shallow surface mulch. To this end it is desirable that at no time during the winter should the surface of the ground become hard and crusted. To effectively accomplish these results considerable winter working is required, the exact procedure varying somewhat to suit individual soil peculiarities. Soil which has turned up rough should be pulverized and firmed when sufficiently moist to crumble. Heavy soils are best reduced with a spike-tooth roller or cross-kill (fig. 3), while light soils respond as well to a corrugated roller or disk. When this preliminary work has been done, the time of performing subsequent winter work will depend upon the occurrence of rain. Each heavy rain that is followed by drying weather will result in the formation of a crust. This should be broken frequent!}' and always before it has become too hard and too thick to disintegrate easily and finely. These workings should not exceed four inches in depth and are most effectively done with an implement whose working depth may be adjusted, such as the chisel or spring tooth harrow (fig. 3). Knife cultivators, or weed cutters should not be used for this purpose, especially if the soil is heavy and moist, because by their shearing action they form a hard tempered strata which interferes with the preparation of a good seed bed. Spring Working. — From the close of the rainy season until planting time there are but two objects to attain, first to hold as near the surface as possible without loss, the moisture which has been stored by the foregoing practices, and second the destruction of weeds of every description. Two implements are indispensable for this work, these are the cyclone (Ventura weed cutter) and the corrugated roller (fig. 3). One or both of these implements should be used at about ten-day intervals up to planting time. The cyclone to destroy weeds and maintain a fine shallow mulch and the corrugated roller to firm the soil and hold the moisture near the surface. Spring plowing is unnecessary on land handled in this way, but where the winter and early spring work is neglected, it must be resorted to in order to turn under weeds and prepare a seed bed. Spring plowing on dry farmed land should not exceed six inches in depth, and should be followed without delay by disking, cross-disking, harrowing and rolling, in order to prevent excessive moisture loss. Sub-irrigated Lands. — Sub-irrigated lands are not dependent upon rainfall for their moisture supply, and much of the winter and spring working necessary on dry lands may be dispensed with. Deep fall plowing, however, is desirable and this should be supplemented by enough winter and early spring working to keep down weed growth and make spring plowing unnecessary. PLANTING Time of Planting. — Horse Beans and Garbanzos may be planted at any time during the fall, winter, or spring, but in the interior districts succeed best when planted in the fall or early spring. The other varieties may not be planted until the soil has become permanently warm and all danger of frost is over. Excepting the Blackeye and Tepary, plantings after June 1 have outyielded earlier plantings in all of the hot interior districts. At Davis in 1917 the following comparisons of ear]y and late plantings were made: Late planting is dependent upon sub- or surface irrigation to supply moisture for germination and growth. In the experiment just quoted the land was irrigated before planting, and the figures represent average yields from several plots of each variety, each plot receiving water at different rates, but all varieties being treated similarly. Blackeye and Tepary beans are not injured by hot weather and yield as well when planted in April or May as when planted later. Consequently they are especially adapted to unirrigated lands where it would be difficult to maintain moisture for late planting. In the Imperial Valle3x beans have yielded best when planted either March 15 or August 15. In the coast districts of northern, central, and southern California, it is customary to plant beans as early in the spring as the season and soil will permit. Here there is no hot weather to avoid by late planting, and early planting obviates the necessity of irrigation. Relative yields for early and late planting at Berkeley, in 1917, are shown in the following table. On overflow lands, and in localities subject to spring frosts, late planting becomes a necessity, and in extreme cases may prevent the growing of beans altogether. In a variety test at Davis planted July 5, 1917, the Tepary, Blackeye, Eed Mexican, Pink, Lady Washington, and Red Kidney varieties, all matured prior to November 1 ; while the Bayo, Lima, Cranberry, Small White, Blue Pod, and Garbanzo varieties all failed to mature. The same varieties were planted at Berkeley July 2, 1917, but only the Red Kidney, Red Mexican, Pink, Lady Washington, and Blue Pod varieties matured prior to November 1. (Table 8.) In energal, most varieties may be planted as late as June 15 on the coast, or as late as July 1 in the interior, but the Blackeye and Tepary may safely be planted as late as July 10 in the interior. Methods of Planting. — The essentials of a good planter are: that it should drop accurately the variety or varieties to be planted, it should be provided with furrow openers that will deposit and cover the seed at the desired depth in the soil or soils to be planted, and it should be equipped with a dropping mechanism which neither crushes nor breaks the seed coat. Large beans, like the Lima or Horse Bean, are best handled by sprocket or cup droppers, while the smaller beans may be handled by plate droppers. In any case the machine should always be tested by running it in gear for a few rods over a hard piece of ground before sending it into the field. Runner, disk, and hoe furrow openers are available ; the runner is most popular in the northern districts, the hoe in the southern, and the disk gives most satisfaction on the newly reclaimed tule lands or on grain stubble. Disk planters have the greatest penetration and run more smoothly than the others on trashy soils, but it is more difficult to make straight rows with them and they depreciate more rapidly than other planters. Lister planters which place the seed in the bottoms of shallow trenches should be used on soils deficient in surface moisture. Homemade listers may easily be attached to ordinary planters. When planting in dry soils it is always helpful to roll the land thoroughly, immediately after planting, using preferably a corrugated roller. Grain drills, although less satisfactory, may be used for bean planting. An eleven-row, seven-inch drill, with all tubes excepting the second, sixth and tenth stopped, will plant beans in 28-inch rows, but is very difficult to regulate. Side-hill planters (fig. 4) constructed with wide wheel bases, and special non-skidding wheels, are now being made and successfully used in southern California. Depth of Planting. — Correct planting depth is initially a question of soil moisture distribution. The planter should be set to place the seed from an inch to an inch and a half deep in the moist soil below the surface mulch ; but in accomplishing this it is undesirable that the total depth including the mulch be more than 2% inches in heavy soils, more than 4 inches in light soils, nor more than 6 inches in peat soils. If the character of the soil changes in different parts of the same field it may be necessary to adjust the planter accordingly. Blackeyes, Teparies, and Garbanzos require the least moisture for germination; the Horse Bean and Cranberry most. Rate of Planting. — The number of pounds of seed required to plant an acre is exactly determined by the number of seed in a pound, and the spacing employed. The following calculations are based on average lots of seed of eleven varieties, planted at sixteen different rates, and check closely with amounts used in the field. Commonly beans are dropped about 6 inches apart in rows 28 inches apart, but large vigorous varieties, such as the Lima, Cranberry, Blackeye, Horse Bean, and Garbanzo, require more space and should be planted in rows 32 to 36 inches apart, and the seed spaced 8 to 12 inches apart in the row. The Garbanzo may even require 12 to 18 inches in the row on good soils in the coast districts. The Tepary, Bayo, Red Mexican, Pink, Lady Washington, and Small White should be planted 6 to 10 inches apart in rows 26 to 30 inches apart ; while the Red Kidney and Henderson Bush should be planted 4 to 6 inches apart in rows 24 to 28 inches apart. These spacings may be increased on rich moist soils and decreased in drier soils; moreover, late plantings require less space than early ones. Filling Blanks and Thinning. — About two weeks after planting all blank spaces should be replanted, using either a hand planter, hoe, or dibble. At the same time the plants may be thinned where they are coming up too thick] y. Choice of Seed. — Precision in planting may be attained only by the use of well-cleaned, well-graded seed of uniform size. If there is any doubt concerning the viability of the seed a germination test should be made, and the rate of planting increased sufficiently to compensate for any deficiencies. CULTIVATION From the time the plants appear above the surface of the ground, until the vines meet and interfere with the passage of implements, the field should be cultivated and hand-hoed as often as is necessary to control weeds and conserve moisture. The first working should be deep and close, using a shovel type cultivator equipped with shields (fig. 5). This will encourage deep rooting and leave the heavier soils in better tilth than if knives were used. Where possible, however, knives or sweeps (fig. 3) should be substituted for shovels for the later cultivations, because they are more effective in the destruction of weeds, yet by virtue of their shallower draft destroy fewer bean roots. When the plants are from three to six inches in height, the field should be carefully hand-hoed for the purpose of destroying weeds in the rows inaccessible to the horse-drawn cultivators. This should be IRRIGATION Time of Irrigation. — Early planted beans are rarely irrigated, but plantings after June 1, excepting on naturally moist soils, are dependent upon irrigation prior to planting to suppty moisture for the germination of the seed. This may be accomplished by the use of furrows, basins, or free flooding, the choice of method depending upon the topography of the land and the texture of the soil. Subsequent to planting water should be applied frequently enough to keep the soil moist and the plants in a thrifty vigorous condition, rather than at any particular stage of plant development. One 3-inch irrigation before, and two after planting have had this effect on a soil of medium texture at the University Farm, Davis, California. Method of Irrigation. — Because water in contact with beans during hot weather is fatal to most varieties, flooding in basins, as practiced in sugar-beet culture cannot be employed, and the land must be level enough to control the water in furrows. To irrigate to the best advantage broad shallow trenches should be prepared between the rows and small streams of water run through them until the soil has been well moistened about the roots of the plants. On soils of medium texture, one or two applications of three acre-inches each during the growth of the crop should give this result. Each irrigation, excepting perhaps the last one, should be followed by a thorough cultivation, and if necessary a hand-hoeing, to prevent the crusting and baking of the soil about the roots. HARVESTING Time of Harvesting. — Bean pods ripen progressively upward from the base of the plant, the entire ripening period usually extending over several weeks. This gives considerable latitude in the time of harvesting operations, but in most instances the primary object is to complete the work before the occurrence of fall rains. For most varieties it is inadvisable to wait for all of the pods to ripen, since this would usually result in the shattering of the oldest ones and extend harvest too late into the season. Generally, cutting should start when the majority of the pods have turned color, yet before the oldest ones have commenced to split. Easily shattered varieties must be cut greener than those which are more retentive of their seed. Blackeyes and Teparies shatter most, and should be harvested when from 80 to 90 per cent of the pods have turned color; even then the oldest pods will have split somewhat. The Red Kidne}^ and Bayo drop their seed freely if allowed to remain standing until the pods are fully dry, but it is not necessary to cut them until nearly all of the pods have turned color. The Horse Bean, Red Mexican, Pink, Lima, Lady Washington, and Small White varieties are more retentive of their seed and do not require as careful attention as the above named varieties ; while the Garbanzo and Cranberrv shatter least of all and may be permitted to ripen almost completely in the field. In the interior districts where shattering losses are greatest, the vines should be cut in a somewhat greener condition, and the work performed during the early morning hours, or at night. Methods of Harvesting. — Small plantings of an acre or two in extent may be cut or pulled by hand, but larger acreages are most economically harvested with some form of bean cutter. The essential feature of a good bean cutter (fig. 4) is a pair of sharp knives, about 3% feet in length, mounted on a sled from which they should stand inward and slope backward at a 60-degree angle. The sled straddles two rows, and the knives are set to run about two inches beneath the surface of the soil, cutting the roots where they are soft, and leaving two rows of beans in one windrow. To do efficient work and reduce hand-lifting after cutting, the knives should be sharpened frequently when in use. Rolling cutters and spreaders attached to the sleds designed to facilitate the passage of the implement through tanlged matted vines have recently come into use and have beerf reported upon favorably. Horse beans are too tall and woody to be handled with ordinary cutters, but may conveniently be cut with either a self -raked reaper, or with a mowing machine. When the latter implement is employed it should be equipped with a windrower in order to obviate the hand work of forking the beans out of the path of the team on the succeeding round. This method also has much to recommend it for the harvesting of Blackeye beans in districts where difficulty has been experienced in cutting tangled masses of vines by ordinary methods without incurring heavy shattering losses. Curing. — When cut slightly green, the vines should be left in the windrows until dry enough to cock safely, but if very green it may be necessary to turn the windrows once or twice before cocking to hasten curing and prevent heating. The side-delivery rake may be used for turning but is objectionable in heavy soils because it mixes small clods with the beans which are not separated in threshing. In the interior districts beans cure more rapidly and may be cocked as cut, light crops having been handled with self -bunching cutters (fig. 8), or hay rakes. It is customary, however, to make the cocks by hand, placing three windrows into one row of cocks. Larger cocks may be made with such varieties as the Red Kidney, Henderson Bush, Lady Washington, and Horse Bean, because they shed their leaves before ripe, and cure more rapidly; but the more leafy varieties, especially in the humid districts, should be placed in smaller cocks. Moreover, small cocks hasten the curing process and should be employed in all the late districts where time is the important element in harvesting. An average sized cock is from four to five feet in diameter at the base and two feet in height, but in windy situations broader lower ones are more desirable. Beans cannot be machine-threshed until the stems have become dry and brittle, the pods dry, and the seed hard. This will usually occur in from two to four weeks after cocking, an unnecessary delay after this time often resulting in considerable shattering in the cock, and in handling to the machine. If carefully manipulated, and thoroughly dried before threshing, beans may be exposed to an inch or more of rain in the field without serious damage, but if rained on while in the windrow or cock, the vines should be turned as soon as they begin to dry on top in order to separate the damp pods from contact with the soil and prevent discoloration. The Floor Method. — The floor method of threshing (fig. 9) is still in vogue in some places, and has some minor advantages over the more modern methods. A threshing floor is prepared by wetting and rolling a level piece of adobe soil until it is smooth and hard ; or a large heavy canvas may be used. A deep layer of cured vines is then placed on the floor or canvas and unshod horses, attached to disks or rollers are driven over them until the seed is threshed free of the pods. The vines are then forked off and the process repeated until several tons of beans have accumulated. The beans are then cleaned in fanning mills and sacked. By this process beans may be threshed somewhat earlier than by machinery, and a higher grade product is obtained. Sacramento and San Francisco warehouses report the average shrinkage in recleaning floored beans at 3 per cent, and that for mate shrinkage and scale their prices accordingly. The Stationary Machine Method. — Machines ranging in threshing capacity from 100 to 2500 sacks per day are available (figs. 4 and 10). The essentials of a good machine are that it be equipped with two or more cylinders, and with concaves and screens capable of separating without waste the varieties to be threshed. Grain threshers are unsatisfactory for the purpose, but may be used by reducing the speed of the cylinder from 1100 r.p.m. to 450 r.p.m., or to 300 r.p.m. for the Blackeye, Tepary, and Henderson Bush varieties, yet maintaining the screens at constant speed. Such machines should be further altered by removing all but one row of concave teeth and one-half of the cylinder teeth and by sharpening the remaining teeth to prevent wrapping. Even with these changes the work is generally unsatisfactory. The Comb Intel Harvester Method. — The combined harvester method is new in California but is gaining favor rapidly (fig. 11). By it the beans are left in the windrows until thoroughly cured, when they are pieked up by a movable threshing machine driven by its own power or drawn by a tractor. It results in the elimination of cocking and hauling, and is efficient and economical when employed under conditions to which it is adapted. PREPARATION FOR MARKET Cleaning and Polishing. — Beans are always recleaned after threshing, in order to insure a ready acceptance on the market. This is done in especially equipped establishments at central shipping points, and is principally a function of commission men and dealers. The process consists of running them through a series of machines ; the first is a screen separator which removes clods, stones, broken beans, bits of stems and pods, and other foreign matter. The second is a Jessup adobe machine consisting of three revolving cylinders which separate by friction, clods the same size as the beans, which were not removed by the separator. Before sacking fine dust particles are removed by an aspirator. An average contract price for cleaning and polishing, including a double run is $1.35 per ton. The polish which can be imparted to beans is chiefly dependent upon the conditions under which they are grown and harvested, but under average conditions beans may be roughly classified as follows as regards polishing. Blackeye Shrinkage. — The loss in weight incident to cleaning is termed shrinkage, and varies from 1 to 10 per cent, with 5% per cent as a general average. Although principally dependent upon the dirt present and the conditions under which the beans were grown and threshed it is also influenced by the variety. The following varietal relationship was established by testing several lots of beans originating in different parts of the state : Spotted Red Mexican Red Mexican Picking. — Discolored beans cannot be separated by machinery and must be removed by hand at an average cost of two cents per pound, the process being termed "hand picking" (fig. 12). It is limited almost entirely to the white varieties and in normal years the total amount hand picked in California does not exceed 2 per cent of the crop. Sacking. — Formerly beans were shipped in 80-pound sacks, but there has been a gradual change and in 1916, 75 per cent of the crop was handled in 100-pound sacks, excepting the Horse Bean, which is shipped in 110-pound grain sacks. Commercial Grading. — Arbitrary grades are established each year by the Grain Inspection Department of the Grain Trade Association of San Francisco. These are based upon samples collected in different parts of the state and are representative of the crop for that season. Iii addition to this Garbanzos, Small White, and Lady Washingtons are separated into grades based upon size. The Garbanzo into five, and the others into two each. DOUBLE CROPPING OF BEAN LAND Well-drained, irrigated land may be so managed that it will yield two crops each twelve months ; but to do this successfully, the planting and harvesting operations must be executed rapidly so as to shorten employed. When the regular bean crop is harvested in the fall, the land should be irrigated and planted to barley, Horse Beans, or field peas. These crops may be harvested during the early summer, and the land again irrigated and planted to beans. COST OF GROWING BEANS The cost of growing and marketing an acre of beans is an uncertain figure which depends upon the general business organization of the enterprise, the character of the equipment employed and the soil to be worked. It also fluctuates from year to year with labor values, season and pests. In the following table itemized statements of cost for three systems of culture practiced in California are given, the figures represent general averages only and cannot be applied without modification to any specific project. *Dry farmed bean lands constitute over 60 per cent of the state's bean acreage and include most of the Small White and Blue Pod territory of the central coast counties, the Lima territory of southern California, and a considerable portion of Blackeye and Tepary territory of the interior districts. . 2 Sub-irrigaed bean lands are of two kinds, including firstly the reclamation districts of the Sacramento River and the Stockton delta, and secondly the high water table lands resulting from irrigation, such as occur in Fresno and Merced counties and other parts of the 5 The net returns here given are based upon a conservative yield of 1200 pounds per acre, and a fixed price of 8 cents per pound, while either of these figures, might with propriety, be increased or diminished by 50 per cent to suit individual cases. UTILIZATION OF BEAN STRAW Bean straw from certain varieties is recognized as a good feed for cattle and sheep, especially when chopped and mixed with silage or alfalfa, and fed with concentrates. Bean straw consists of the stems and pods of the plants, all the leaves being lost in curing and threshing, and since the different varieties vary greatly both in the texture and composition of these parts, the straws which they yield are of unequal feeding value. (Table 11.) By M. E. JAFFA and F. W. ALBRO The data here reported are the results of cooperative work between the Divisions of Nutrition and Agronomy. Sixteen samples of beans were examined and in connection therewith the corresponding straw and pods. Table 11 shows the analyses of the seeds, straws, and pods of the principal California varieties. Composition of Seed. — The average protein percentage of the beans examined is 20.84. The samples which depart materially from the average are the French White, showing 26.34 per cent, the Spotted Red Mexican, with 22.23 per cent, and the Bayo with 22.58. It may be said in general that with the exception of the three varieties just mentioned the protein content is low as compared with analyses of beans reported by different authorities. In Henry's "Feeds and Feedings'' we find 26 per cent protein quoted for the Horse Bean and 27.02 for the Tepary. It is well known that the average protein content of California wheat is lower than that raised in localities -of the middle west and northwest, and this is true even for the same varieties. The ash for the sixteen varieties analyzed averages 4.11 per cent. No one variety departs materially from this figure which corresponds well with that obtained elsewhere. It will be noted upon examination of the table that one variety, the Garbanzo, 6.25 per cent, stands out very prominently with reference to fat. The average for sixteen varieties is 2.26 per cent. The Pink, with 3.65 per cent, and Garbanzo, with 6.25 per cent, being the only varieties differing materially from this average. The maximum percentage 7.10 per cent of crude fiber is shown for the Horse Bean, while the minimum is observed in the case of the Garbanzo or Chick pea, yielding 2.34 per cent, the average for the sixteen varieties being 4.25 per cent. This agrees very closely with figures obtained on similar varieties noted in various publications. Carbohydrates, excluding crude fiber, constitutes the main ingredient of the bean seed, the average for the varieties tested being 58.62 per cent. The maximum 63.82 per cent is yielded by the Blackeye variety, while the minimum 53.99 per cent is credited to the French White. Composition of Straws. — Cereal straws show low percentages of protein, the highest, 3.9 per cent, being recorded for rice. The minimum for bean straw, on the other hand, is 3.5 per cent. The maximum protein content for bean straw, 9.86 per cent, is credited to the Tepary. The Spotted Red Mexican, 7.18 per cent, ranks second. Seven varieties out of the fifteen yield upwards of 6 per cent of protein, while the average for the fifteen is 5.68 per cent. This is a very favorable showing for bean straws as compared with similar cereal by-products. The fat yield with the exception of the Garbanzo corresponds to similar determinations with the cereal straws. It is of interest to observe that while the bean straws are richer in protein than those of the cereals, they also rank higher than the latter in crude fiber, while the figures for water and fat do not differ materially. It therefore follows that the nitrogen-free extract of the bean straw is lower than that of the cereal by-products. Composition of Pods. — The percentages indicated for the protein are low, with the exception of the varieties French White and Blue Pod showing 7.38 and 5.96 per cent, respectively. The average protein content for thirteen varieties, excluding the above, is 3.91 per cent, while the average for the fifteen varieties is represented by the figure 4.29. The bean pods all rank high in crude fiber. The minimum figure for this ingredient is noted in the case of the Cranberry, accounting for its usefulness as a garden stringless snap variety. It also ranks low in protein and, therefore, correspondingly high in carbohydrates. This should render it more valuable for a human food than either the Lima, Small White, Tepary, or Garbanzo, with 37.20, 34.85, 36.97, and 33.48 per cent crude fiber, respectively. The Blue Pod, however, should even outclass the Cranberry on account of its high protein content and low percentage of fiber. By E. R. deONG Bean Weevil (Acanthocelides obtectus). — The weevils attacking beans are grayish black insects about one-eighth of an inch long, with head bent at right angles to the body, and the tip of the abdomen projecting beyond the wing covers. The young of these are tiny gray larvae or grubs, one or more of which may be found in a single bean. Infestation of the bean may begin either in the field or when the crop is stored, for the weevils frequently live over in waste beans of the previous crop. In the field the egg is laid on the newly formed bean pod ; the larva hatching from this egg burrows through the pod and into the young bean. The wound formed is inconspicuous and should not be confused with the work of larger insects which sometimes consume the greater part of the contents of the pod. The larvae which attack the beans in the field mature after the crop is stored, emerging as adult beetles to begin ovipositing on the surface of the beans or in the old burrows. This generation of grubs burrows into the dry bean as readily as did those of the first generation into the green bean. Breeding continues throughout the winter, unless checked by low temperatures, there being a possibility of five to eight generations a year. Hence, beans which are slightly infested when stored in the fall may be utterly destroyed by planting time the following spring. The food value of the crop may be entirely destroj^ed, particularly when several larvae develop in a single bean, and its value for seed may be seriously impaired, the latter injury being in direct proportion to the number of weevils present. Seed which has been attacked by two or more larvae may germinate and make a good growth, but such plants may set very little seed. Control. — The crop should be harvested as early as possible when there is danger of infestation in the field and stored in a room free from weevils. Fumigate the beans with carbon disulphide at the first sign of infestation, using ten pounds per thousand cubic feet in a room that is only approximately air tight. If a specially built fumigating room is available, the amount of carbon disulfide may be reduced to three pounds per thousand cubic feet, or sodium cyanide may be substituted for the former chemical, it being used at the rate of one ounce per hundred cubic feet. The latter material should be given preference in fumigating seed beans as there is less danger of injuring their perminating qualities when it is used. Horsc-Bean Weevil (Bruchus rufimanus). — This insect feeds only on the Horse Bean, the attack in the field and the injury inflicted being similar to that of the species feeding on small beans. There is this difference, however, in their life history : The Horse-Bean weevil has but one brood a year which is reared in the green bean. The egg is deposited on the pod, the larva hatching from this egg burrows into the developing bean seed, pupates there and emerges as a mature beetle which lies dormant until spring. Control. — The same measures are applicable for this species as for the one working on small beans with this additional measure, that if the beans are held over one year in a tight box or sack, from which the weevil cannot escape, the insects will all die and the seed can be used the following season without danger of further infestation. Red Spider (Tetranychus tel-arms). — A very minute plant mite, varying in color from green to deep red, which is found in the leaves of beans and many other plants. This mite is a serious pest of all our summer-grown beans, excepting the Garbanzo and Blackeye. The eggs, which are microscopic in size, are laid directly on the under side of the leaf or in the web which it spins. The entire life of the spider covers from four to seven weeks in hot weather and since each female lays from fifty to one hundred eggs, the possibilities for increase are enormous. This mite passes the winter in a dormant condition in the ground near the plants upon which it feeds, or on the root-talks of overwintering plants, such as wild morning glory (Ccmvolvidus arvensis), or it may continue to feed and perpetuate itself on the leaves of other low-growing plants in sheltered places. AVith the coming of warm weather the mite becomes active and begins to increase, but not to any marked extent until the hot weather of July and August. At this time the females are particularly active in crawling from plant to plant and even over the ground in search of new food plants. Wind also aids in their dispersion, and when feeding on trees, they may be carried a distance of several hundred feet by a strong breeze, starting a colony on any suitable host plant. be done to the entire crop. Control. — A careful application of sulphur on the under side of the leaf, when the attack is first noticed, or by way of precaution, at the beginning of the blooming season is the cheapest and most satisfactory form of control. Very fine dusting sulphur may be applied at the rate of twenty to forty pounds per acre, with a blower, either by means of a hand outfit or a power dusting machine. The important point is to distribute the chemical evenly over the under side of every leaf, for sulphur is effective over only a small fraction of an inch. One application will last two or three weeks and if done carefully and thoroughly should hold the spider in check so that a crop can be matured. If desired the sulphur may be applied as a wet spray by first mixing the sulphur into flour paste, using the latter at the rate of four gallons of paste to one hundred gallons of spray; Professor Gray's method of using glue water (one ounce of glue dissolved in one gallon of water) for mixing the sulphur will also be found very satisfactory. Ten pounds of sulphur for a 200-gallon tank of spray is the common formula for liquid applications. Bean Thrips (Ileliotrips fasciatus). — The adult insect is about 1/25 of an inch in length, grayish black in color crossed with white bands. It is easily distinguished from the red spider by the elongated body and the presence of wings ; and the leaves upon which they feed are spotted with black excrement and there is no web. The larvae are almost transparent but with deep red markings along the sides of the body, both stages of the insect are usually found in the under side of the leaf or on the green pods. Winter is passed in the adult stage, egg-laying beginning early in the spring on some one of the numerous host plants. The eggs are inserted in the leaves or stem of the plant. Pupation takes place in the dry leaves on the ground or beneath clods. It develops more slowly than the red spider but there is a possibility of three or four broods a year in California. Leaves infested with thrips turn pale and drop and if the attack is severe entire defoliation may follow. The bean pod takes on a silvery white appearance, impairing its value as a green vegetable. Control. — This insect is seldom injurious enough to warrant an effort towards control. If the plants are kept in a thrifty condition with plenty of available moisture, they can usually withstand the attack, but if necessary to spray, tobacco decoctions may be used, such as nicotine sulphate combined with soap. Water 50 gallons Dissolve enough soap in water to form suds; pour into the spray tank and add the nicotine sulphate. Apply the spray to the under sides of the leaves by means of an angle nozzle. Bean Aphis (Aphis r unite is). — This aphid attacks all species of beans, but since the insects are most abundant in the spring, the Horse Bean, which is commonly maturing at this time, usually suffers more than the other varieties, while the Garbanzo is practically immune from attack. When necessary to spray the same formula as recommended for the bean thrips may be used. Flea Beetles and Diabrotica. — Bean foliage is sometimes infested by tiny black or brownish jumping insects, known as flea beetles, which eat irregular holes in the leaves. Another insect frequently invading bean fields in great swarms is the Diabrotica, a green, blackspotted beetle, 4/16 to 5/16 of an inch long, which strips the foliage and even feeds on the stems. It is very difficult to poison it but a careful application of arsenicals will kill part of the beetles and check the attack of the others, thus giving an opportunity for the plant to recover. Lead arsenate is commonly used at the rate of eight pounds to one hundred gallons of spray, the application being made both to the upper and lower sides of the leaf. The standard or Pyro type of lead arsenate should be used in the interior valleys when there is no danger of damp or showery weather, but under the latter circumstances the neutral or Ortho-lead arsenate should always be used, as it is much less apt to burn the foliage. In the coast regions subject to fogs the neutral is the only form that can be used with any degree of safety. Another spray used as a protection against beetles but which acts only as a repellant is the Bordeaux mixture : Dissolve the copper sulphate in a wooden vessel, slake the lime in a separate container and pour the solutions together into the tank of water; do not mix the concentrated solutions. Lead arsenate may be added to the Bordeaux if desired. If grasshoppers begin to migrate into the bean field a poisoned bran bait should be scattered along the edge of the field from which they are entering. The arsenical spray on the foliage should not be trusted to check the inroads of large numbers of grasshoppers for, on account of the slow action of arsenic, much damage will result before the outbreak is checked. Wireworms sometimes cause a loss to beans planted on land infested with this larva. Control of this insect is very difficult, but by late planting and using an excess of seed a stand can often be secured even when wireworms are very abundant. Experiments with Stocks for Citrus. 291. Growing and Grafting Olive Seedlings. A Comparison of Annual Cropping:. Biennial Cropping, and Green Manures	22,443	common-pile/pre_1929_books_filtered	beancultureincal294hend	public_library	public_library_1929_dolma-0014.json.gz:2166	https://archive.org/download/beancultureincal294hend/beancultureincal294hend_djvu.txt
gNbt950qbeVA6VTk	5.1: Polyhedra	5.1: Polyhedra Lesson Let's investigate polyhedra. Exercise $\PageIndex{1}$: What are Polyhedra? Here are pictures that represent polyhedra : Here are pictures that do not represent polyhedra: - Your teacher will give you some figures or objects. Sort them into polyhedra and non-polyhedra. - What features helped you distinguish the polyhedra from the other figures? Exercise $\PageIndex{2}$: Prisms and Pyramids - Here are some polyhedra called prisms . Here are some polyhedra called pyramids . - Look at the prisms. What are their characteristics or features? - Look at the pyramids. What are their characteristics or features? - Which of these nets can be folded into Pyramid P? Select all that apply. - Your teacher will give your group a set of polygons and assign a polyhedron. - Decide which polygons are needed to compose your assigned polyhedron. List the polygons and how many of each are needed. - Arrange the cut-outs into a net that, if taped and folded, can be assembled into the polyhedron. Sketch the net. If possible, find more than one way to arrange the polygons (show a different net for the same polyhedron). Are you ready for more? What is the smallest number of faces a polyhedron can possibly have? Explain how you know. Exercise $\PageIndex{3}$: Assembling Polyhedra - Your teacher will give you the net of a polyhedron. Cut out the net, and fold it along the edges to assemble a polyhedron. Tape or glue the flaps so that there are no unjoined edges. - How many vertices , edges , and faces are in your polyhedron? Summary A polyhedron is a three-dimensional figure composed of faces. The ends of the edges meet at points that are called vertices. A polyhedron always encloses a three-dimensional region. The plural of polyhedron is polyhedra. Here are some drawings of polyhedra: A prism is a type of polyhedron with two identical faces that are parallel to each other and that are called bases . The bases are connected by a set of rectangles (or sometimes parallelograms). A prism is named for the shape of its bases. For example, if the base is a pentagon, then it is called a “pentagonal prism.” A pyramid is a type of polyhedron that has one special face called the base. All of the other faces are triangles that all meet at a single vertex. A pyramid is named for the shape of its base. For example, if the base is a pentagon, then it is called a “pentagonal pyramid.” A net is a two-dimensional representation of a polyhedron. It is composed of polygons that form the faces of a polyhedron. A cube has 6 square faces, so its net is composed of six squares, as shown here. A net can be cut out and folded to make a model of the polyhedron. In a cube, every face shares its edges with 4 other squares. In a net of a cube, not all edges of the squares are joined with another edge. When the net is folded, however, each of these open edges will join another edge. It takes practice to visualize the final polyhedron by just looking at a net. Glossary Entries Definition: Base (of a Prism or Pyramid) The word base can also refer to a face of a polyhedron. A prism has two identical bases that are parallel. A pyramid has one base. A prism or pyramid is named for the shape of its base. Definition: Face Each flat side of a polyhedron is called a face. For example, a cube has 6 faces, and they are all squares. Definition: Net A net is a two-dimensional figure that can be folded to make a polyhedron. Here is a net for a cube. Definition: Polyhedron A polyhedron is a closed, three-dimensional shape with flat sides. When we have more than one polyhedron, we call them polyhedra. Here are some drawings of polyhedra. Definition: Prism A prism is a type of polyhedron that has two bases that are identical copies of each other. The bases are connected by rectangles or parallelograms. Here are some drawings of prisms. Definition: Pyramid A pyramid is a type of polyhedron that has one base. All the other faces are triangles, and they all meet at a single vertex. Here are some drawings of pyramids. Definition: Surface Area The surface area of a polyhedron is the number of square units that covers all the faces of the polyhedron, without any gaps or overlaps. For example, if the faces of a cube each have an area of 9 cm 2 , then the surface area of the cube is $6\cdot 9$, or 54 cm 2 . Practice Exercise $\PageIndex{4}$ Select all the polyhedra. - A - B - C - D - E Exercise $\PageIndex{5}$ - Is this polyhedron a prism, a pyramid, or neither? Explain how you know. - How many faces, edges, and vertices does it have? Exercise $\PageIndex{6}$ Tyler said this net cannot be a net for a square prism because not all the faces are squares. Do you agree with Tyler? Explain your reasoning. Exercise $\PageIndex{7}$ Explain why each of these triangles has an area of 9 square units. (From Unit 1.3.2) Exercise $\PageIndex{8}$ - A parallelogram has a base of 12 meters and a height of 1.5 meters. What is its area? - A triangle has a base of 16 inches and a height of $\frac{1}{8}$ inches. What is its area? - A parallelogram has an area of 28 square feet and a height of 4 feet. What is its base? - A triangle has an area of 32 square millimeters and a base of 8 millimeters. What is its height? (From Unit 1.3.3) Exercise $\PageIndex{9}$ Find the area of the shaded region. Show or explain your reasoning. (From Unit 1.1.3)	1,258	common-pile/libretexts_filtered	https://math.libretexts.org/Bookshelves/Arithmetic_and_Basic_Math/Basic_Math_(Grade_6)/01%3A_Area_and_Surface_Area/05%3A_Surface_Area/5.01%3A_Polyhedra	libretexts	libretexts-0000.json.gz:21373	https://math.libretexts.org/Bookshelves/Arithmetic_and_Basic_Math/Basic_Math_(Grade_6)/01%3A_Area_and_Surface_Area/05%3A_Surface_Area/5.01%3A_Polyhedra
PbBdYoTGDddfJiTU	Dental materia medica, therapeutics and prescription writing, by Eli H. Long.	ELI H. LONG, M.D. PROFESSOR OF DENTAL MATERIA MEDICA AND THERAPEUTICS IN THE DENTAL DEPARTMENT, EMERITUS PROFESSOR OP MATERIA MEDICA AND THERAPEUTICS IN THE MEDICAL DEPARTMENT, PROFESSOR OF TOXICOLOGY IN THE PHARMACY DEPARTMENT, UNIVERSITY OF BUFFALO; CONSULTING PHYSICIAN TO THE BUFFALO GENERAL HOSPITAL PREFACE TO FOURTH EDITION. While progress in medical science as applied to dentistry has required a thorough revision of the text, the original aim of the author to adapt the book particularly to the needs of the dental student, has been adhered to. The chapters on Analgesia and Anesthesia have been largely rewritten, also the article on Syphilis, and a new chapter on Animal Drugs has been added, all of which necessitated enlargement by twenty-five pages. Doses have been generally included in the text, the average U. S, P. dose being employed for official substances, while the range of permissible dosage for all internal drugs is given in the Index of Drugs. The author expresses his appreciation of the great assistance rendered by his friend, the late William H. Lane, B.S., M.D., D.D.S., who carefully revised the chapters on Local Remedies. The courtesy and patience of the publishers is likewise acknowledged, since much delay on the author's part in completing the revision was occasioned by a period of ill-health. INTRODUCTION. The need of a book on Materia Medica and Therapeutics, prepared especially for the specialist in dentistry, indicates a certain distinctness of practice that does not apply to other specialties. The general textbook on this branch is all that is wanted by the general surgeon, the ophthalmologist, the gynecologist, and in fact by all specialists whose preparation includes a complete medical course of study. Whether we regard the condition as normal or not, the fact is apparent that the practice of dentistry today has too little in common with general medicine. This is likely to be true to a degree for the future also, even though the tendency now is to broaden the curriculum of dental colleges. The relation of mouth conditions to the health of the whole body has in recent years assumed an importance that calls for a broader training of the dental specialist, so that he may be able to stand upon common ground with the physician in solving the problems that present themselves. The preparation for special practice cannot be too broad as to principles, but, at the same time, there is a practical limit to the detail of general medicine that can profitably enter into the dental student's undergraduate work. The matter entering into these chapters is written from a standpoint that recognizes the need of a special text-book, but that also realizes the narrowing tendency that inevitably attends the supplying of that need. The author, therefore, makes no apology for attempting to illustrate by diagrams, with explanatory text, the action of the most important internal drugs upon the general system, nor for the somewhat extensive treatment of classes of remedies and preparation of drugs. Certain general terms require definition or comment at the outset. The term remedy inchides any agent, of whatever character, employed in the treatment of disease. A remedy is not necessarily a substance; it may be some external force or simply an influence. position of medicines or entering into chemical processes, or any poison. Materia medica, in a restricted sense, means the materials or substances used in medicine. In a broad sense, the term means the science of drugs in their varied relations, i. e., their sources, properties, preparations and uses. ing and dispensing medicines. Pharmacology has had much the same meaning as materia medica in its broad sense, but it has more recently come to be applied to a distinct part of the science of drugs, that which treats of the action of drugs upon the tissues, organs and functions of the body. Therapeutics is the science and art of employing remedies in the treatment of disease. While therapeutics should have a scientific basis in the knowledge of the action and effects of remedies, practical treatment of disease will alwaj^s remain an art, because of the many modifying factors that render scientific precision impos^^ible. Toxicology is that part of medical science which treats of poisons. It includes the nature and effects of poisons, their doses, their detection, and the treatment of the conditions resulting from poisoning. As a standard for the purity and uniformity of drugs and preparations, we have the volume known as the United States Pharmacopoeia,* which is the recognized authority for this country. Other countries have similar standards. The book does not treat of the action or uses of medicines, but it furnishes a list of recogn ized drugs, with descriptions, tests of purity, etc., and of preparations, with their formulas. The drugs and preparations so recognized are called "official." An average dose is given of each drug and preparation used internally. This book, * The IT. S. Pharmacopa ia was first issued in 1820. It is sul)je('ted to revision every ten years. It is not issued by the Government, as is the case with the pharmacopa'ias of most countries, but it is authorized by the professions of medicine and pharmacy. A convention, representing medical and pharmaceutical colleges and associations, meets once in ten years in the city of Washington, for the purpose of directing its revision, wliich is accomplished through a committee of revision. being our authority upon drugs and their preparations, forms the basis of our text-books on materia medica, pharmacy and therapeutics. It is revised every ten years under direction of the professions of medicine and pharmacy. The abbreviation (U. S. P.) always indicates this work. A Dispensatory is a comprehensive text-book on materia medica. It has been called a commentary upon the Pharmacopoeia ; but it is more than this, in that it treats of a vast number of substances that are not official, and discusses also the uses of drugs. But it is not an authorized work as is the Pharmacopoeia. The National Formulary (X. F.) is a very important collection of formulas that are not official, but which are in common use. It is prepared under the direction of the American Pharmaceutical Association, and is, therefore, in a sense authoritative. In the study of the practical values and uses of remedies we employ several related terms which are too often confused. Physiologic action, physiologic effect and therayeutic effect are terms distinct in meaning, and they should be properly understood. The action and effect of a drug cannot always be the same. The action may be obscure; the effect must be apparent. To illustrate: Tincture of iodine applied in a case of pericementitis has its action upon the mucous membrane where applied, but the jjhysiologic effect that we desire is alteration of the disturbed circulation in the pericementum. Again, we may have physiologic action and physiologic effect without therapeutic effect, the latter depending upon a relief of symptoms. In the above condition the therapeutic effect would be relief of the pain; but the inflammation might be so severe that our therapeutic effect would not follow. The actio?! of a drug, then, consists of a change of conditions, chemic, thermic, electric or structural, which determines an alteration of function. This alteration, when apparent, is known as the effect of the drug. Within the limits of normal function this effect is physiologic, while a disturbance, or depression beyond the normal, is a toxic effect. When the action is in the direction of restoring normal conditions, the effect is usually a relief of symptoms of disease, and is called the therapeutic effect. We may have the action and the physiologic effect of a drug in a normal, healthy individual, but never the therapeutic effect. Some drugs may cause unpleasant or undesirable effects aside from their main action. These are called untoivard effects, and their avoidance calls for discrimination in administration and dosage. Closely related is the matter of susceptibility to drug action, some individuals being very sensitive to the influence of a certain drug and readily showing untoward effects of the same. On the other hand, tolerance to certain drugs may be acquired by continued use, so that very large quantities may be taken without dangerous results. The habit drugs, particularly morphine and cocaine, exhibit this fact; victims of habitual use of either often being able to take many times the poisonous dose. A cumulative effect is sometimes seen with slowly acting drugs, particularly when elimination is faulty. The successive doses given accumulate and their full action is likely to be excessive, disturbing or poisonous. Digitalis is a drug which needs care in its use to avoid cumulative effect. As related to the emplo^Tnent of remedies, the term indication means the symptom or condition that calls for a particular remedy or course of treatment, while contra-indication means the condition or symptom that forbids the use of a certain remedy or method. A symptom is an evident disturbance or alteration of function or structure, which is the expression of disease. A sign is a symptom or phenomenon that is positive evidence of some particular disease. Diagnosis means the determination, by means of s^Tnptoms or signs, of the character or name of the disease, while prognosis is the prediction of the course or termination of the same. The term resolution indicates the changes in diseased tissues toward the normal, and means structural recovery. Dissolution, on the contrary, means death. The term specific has tw^o meanings. Applied to a remedy, it means that the remedy can be invariably relied upon to produce a therapeutic effect in a certain disease, as quinine in malarial fever or antitoxin in diphtheria; but when we speak of specific disease we mean syphilis. The term is thus used among physicians to designate, in a way that cannot give offence, that disease that in its true name has the stigma of vice attached to it. PREPARATIONS. The terms dnig and medicine are not strictly sjoion^Tnous, although popularly so regarded. Both mean material substances, therefore they exclude such agents as heat, light and electricity. The term medicine implies use in the treatment of disease, while the classes of drugs include many substances that are known usually as chemicals and that are never used directly in treatment. Therefore: chemical processes. A yoisonous drug is one which is capable of causing a disturbance of function, or disease, or death. Poisons must be included among drugs, but in their poisonous quantities they cannot be medicines, although a substance that in a large dose is a poison may in a smaller dose be a medicine. Poisons are discussed in greater detail in a separate chapter. The term remedy is more inclusive than the term medicine, meaning any agent (whether a substance, a force, or any influence whatever) employed in the treatment of disease. In another chapter occurs the classification and discussion of remedies. Drugs are classified variously: in respect of their sources, as vegetable drugs, mineral drugs and animal drugs; regarding their constitution, as organic and inorganic; and respecting their uses, as medicinal and chemical drugs. In the development of the science of drugs, the beginning had to be with two quite distinct groups of substances — the simple chemicals, or chemical elements as we now know them, such as zinc, mercury and iron, and the more complex organic vegetable drugs, such as opium, cinnamon and ipecacuanha. The chemical elements, as a rule, were found to possess comparatively slight medicinal value while in their simple form, and except for their power of chemical combination would have remained of little use. Their great value, therefore, depends upon 22 DRUGS AND MEDICINES the large number of useful combinations which they form. To illustrate: ]\Iercury or quicksilver in its pure form is insoluble and nonmedicinal, but combined with chlorine in a certain proportion it yields calomel (HgCl), a valuable cathartic; and in another proportion it yields corrosive sublimate (HgCl2), a powerful antiseptic; again, it may be combined with sulphur to produce a ^-aluable red coloring agent known as vermilion (HgS). An almost endless \'ariety of combinations among the eighty-three chemical elements now known, provides a field from which we draw many agents used in dentistry, with a limitless future as to new compounds. ]\Iuch of both scientific and commercial energy is being expended in the synthesis, or putting together, of chemicals in order to secure new valuable compounds. The products are often referred to as synthetics. Phenacetin and saccharin are examples of this class. Remarkable also it is, that, besides new products, many of the active principles originally obtained from organic drugs are now produced s^^lthetically in the laboratory. Salicylic acid, artificial oil of wintergreen, and even phenol, furnish examples of such. In strong contrast to the above, the other group, the organic drugs, besides being of use in their crude form, lend themselves to division and analysis rather than to combination. They are complex in their composition, therefore one organic drug may contain from one to a dozen or more distinct substances of medicinal value. These are called crmstituents , active imnciples or proximate principles of the drug. For example, opium, the juice of the unripe seed-capsule of the opium poppy, contains gum, albumin, sugar, wax, pectin, salts, caoutchouc, acids and at least twenty alkaloids, among which are morphine and codeine. The most important work being now done upon these complex drugs is that of isolating their active principles or constituents in a state of purity and stability; and when a single principle is found to represent the drug fully it is commonly used in its stead. or crude substances. It would be interesting to trace the development of pharmacy in bringing forth the different kinds of preparations, in response always to definite needs, and to note individual characteristics in each class; but it must suffice to state in general that they fulfil needs in preparation, such as solubility and permanency, and likewise needs in administration, such as pleasant form and taste, definiteness of strength, external uses, etc. These preparations are obtained by simple solution of a drug, by extraction of its active principles, or by incorporation of it with a vehicle, the objects of such preparations being to secure the medicine in a suitable form, in definite strength, and in a permanent or stable condition. Occasionally chemical action is employed, but the larger number are produced without any chemical change occurring in the ingredients. The preparations produced without chemical action are known as galenical preparations, being so named after the ancient physician Galen. With so many drugs, furnishing so large a number of preparations, the need of standards of identity, purity, strength, etc., is very apparent. Such standards are provided in the United States Pharmacopceia.* As regards strength of organic drugs the amount of active principle present seemed to be the best basis for standardization, and much progress has been made in recent years in establishing processes of assay to which the substances must conform. Several that do not admit of a determinative chemical assay are now tested biologically. Tests of various salts and chemicals have been also added, so that now the Pharmacopceia gives about 300 assays of drugs and preparations. This contributes ^'ery much to definiteness and insures greater reliability and accuracy in the use of our most important medicines. Among all of the classes, the fluidextracts deserve emphasis as the most representative preparations of the crude organic drugs. They are so prepared as to contain all of the active principles, to be of a uniform definite strength, and to keep indefinitely. The tinctures may be regarded as equal in importance, being permanent alcoholic solutions of drugs, though weaker than fluidextracts. Syrups present the drugs in form for pleasant administration, as also do pills and troches. external uses. The A'arious preparations are presented in the folio ^ving list, arranged in classes alphabetically, with each class defined, and the names given of the most important ones, or those of interest to the dental specialist. The names given, both for each class and each individual preparation, are those employed in the official volume, the U. S. Pharmacopoeia. Collodium cantharidatum. CoUodia are employed to protect or to constrict tissue, or to apply an irritant drug to the skin. Having the nature of a varnish, they cannot be applied unless the surface is perfectly dry. They dry quickly by evaporation of the ether and alcohol. CLASSES OF OFFICIAL PREPARATIONS 25 The U. S. Pharmacopoeia gives a general formula for decoctions of 5 per cent, strength. Unless some preservative is added, they do not keep well; so they must be freshly prepared. Elixir. — An Elixir. — A sweetened, aromatic, spirituous preparation of one or more drugs, designed for pleasant administration. Elixir aromaticum. Elixir glyc>Trliiz£e. Some elixirs are used only as vehicles, their alcoholic character permitting the addition of fluidextracts without precipitation. The National Formulary contains the formulas of a large number of elixirs for the administration of drugs of unpleasant taste. Emulsions are in no sense solutions, their object being to carry substances that are not soluble in water. In case of asafoetida, a gumresin, there is sufficient gum in the drug to carry the resin, so that the emulsion is formed hy rubbing up the drug with water only. Extractum ergotse. Extractum opii. The object of this class is chiefly concentration of the drug, but the keeping qualities are usually also improved. The form permits of their being made readily into pills, or of ready solution. Infasum digitalis. Infasum sennge compositum. There is also a general formula for infusions of 5 per cent, strength. These preparations do not keep well. Either they must be freshlymade or some preservative added. Linimentum. — A Liniment. — A liquid preparation for external use, usually possessing a stimulating or sedative property. Liniments vary much in character, but most of them contain some oil or soap. Oleoresina. — Ax Oleoresix. — X liquid or semiliquid mixture, chiefly of oil and resin, extracted from the drug by percolation with ether. [They are really ethereal extracts.] Oleoresina capsici. Oleoresina zingiberis. The term also applies to certain natural products, consisting of mixtures of oil and resin, which occur as exudates from the trees containing them. These may be liquid or solid. Examples are: Oleum. — Ax Oil. — A natural compound of one or more of the fatty acids with glycerin. True oils and fats must be capable of saponificatioQ, /. e., forming a soap when treated with an alkali. They vary in consistence and in melting point, chiefly on account of the varying proportions of olein, palmitin and stearin which they contain. They are not volatile. They occur naturally in animal tissues and in the seeds of many plants and trees. Spermaceti and wax are similar to these in that they are saponifiable, but they contain no glycerin. Petrolatum (vaselin) is not a fat, although it may be used as a basis in ointments. Oleum Destillatum. — A Distilled Oil. [Volatile Oil. Essential Oil.] — A volatile, oily principle usually obtained from the crude drug b}^ distillation. They are not saponifiable, therefore they are not true oils. The volatile oils are usually the essential principles of the plants yielding them. It will be noticed that many of them are obtained from spices. The chief object in the use of pills is to avoid the unpleasant taste of medicines. Sometimes, however, they may be used in order to secure a slow or delayed absorption of the medicine. Resina. — A Resin. — A solid preparation consisting chiefly of resinous substances. They are insoluble in water, and are usually obtained by precipitation from tinctures by the addition of water. As a class resins are soluble in alcohol, ether, chloroform and oils. They soften with the aid of heat. * These do not exist ready formed in the drug, but are developed when the drug is moistened with water, in the presence of which a reaction' between certain constituents occurs, with the formation of the volatile oil. This process must precede distillation in case of these. With the exception of these two, which are poisonous and should never be given in larger dose than TTlJ (0.03 gm.), the dose of. the volatile oils is mi-5 (0.06-0.30 gm.). GuM-RESixs are related to the above, but differ from them in composition and solubility. They contain a gimi associated u^ith the resin; therefore they are only partly soluble in ahohol and are partly soluble also in water. The two most important ones are: Styrax. Balsamum tolutanum. Sapo. — ^A Soap.- — An alkaline product of the reaction between a fatty acid and either soda or potassa.* Soaps are prepared by heating a fat or oil with an alkali — potassa yielding a soft soap and soda a hard soap. Suppositorium.- — A Suppository. — A solid, conical mass, containing one or more medicinal substances, intended for introduction into some passage or cavity of the body. A suppository should melt readily at the temperature of the body, to ensure which a base of either cacao butter or glycerinated gelatin is commonly employed. The size may vary from 15 to 60 grains (grams 1 to 4). The U. S. P. gives general directions for their preparation with either base. They are made of different shapes, according to the particular use for which they are intended. Those for introduction into the urethra, often called bougies, are pencil shaped, while for rectal and vaginal use they are conical or oval. * This definition is a restricted one, intended to define the official soaps. — A Syrup. — An aqueous medicinal solution containing sugar nearly to saturation. [A few syrups are without decided medicinal value, being used chiefly as vehicles.] Being rather thick in consistence, they may hold solid particles in suspension, thus possessing added value as excipients, and their consistence also gives them something of the quality of demulcents. As a rule, they are weaker than tinctures. In point of number the tinctures hold first place, there being 54 official. Trituratio. — A Trituration. — A powder consisting of a potent drug diluted and finely divided by means of sugar of milk. The IT. S. P. gives a general formula for the preparation of 10 per cent, triturations. The following is the only official one named separately : Trituratio e'aterini. some of which do not conform exactly to the definition given above. Tablet Triturates combine the characters of the trituration and the troche, having the medicine in a finely divided state and in a form pleasant to take. A great variety of combinations are now prepared in this form, presenting a convenience of handling and of administration that does not obtain with the liquid forms of medicine. With some drugs, however, the fresh liquid preparations are more reliable and greatly to be preferred. Hypodermic Tablets. — For h^'podermic use it is desirable to have the medicine readily soluble, therefore the tablet should contain little or nothing besides the active substance. With some drugs a little mucilage may be required to secure adhesion of the particles, but the least possible amount should be used. Compressed Tablets. — ^Many substances are sufficiently cohesive to admit of being compressed into tablet form without the addition of any adhesive material. Some that take the tablet form readily do not maintain it indefinitely. They may be deliquescent and become soft or even liquid ; or they may be efflorescent and become dry and crumble. Such will require to be kept in tightly-corked bottles. The compressed tablets, however, are very convenient and usually present the drug in its pure form. Ointments are intended to protect, soften or medicate the skin. A few, such as unguentum hydrargyri, are used for the purpose of systemic medication by being rubbed into the skin. CONSTITUENTS OF DRUGS. In the foregoing hst of preparations there are some that are, as well, simple constituents. This is true of the oils, the distilled oils and the resins, these being obtainable by simple means in a fairly pure state, but there are other constituents that are less easily separated from the drug, but which are usually the most active and important of its principles. As we study the value of an organic drug in its desirable medicinal effects, it is evident that the latter must be dependent, not upon the whole drug, but upon the action of one or more of its constituents or proximate principles;* for every crude drug contains inert matter, while some have constituents of undesirable action. It is important to know just which of the principles are medicinally valuable; and where such are capable of isolation there is evident advantage in their employment instead of the preparations of the whole drug. Since the recognition of morphine in opium by Setiirner, in 1817, much effort has been expended in securing the active principles of the various drugs in a state of purity and solubility for practical use. So successful has the effort been with many of our leading drugs that their quality is now gaged by the amount of active principles present, e. g., opium cannot be official unless it contains 9.5 per cent, of morphine. * The term proximate principle is defined to be any substance, either simple or compound, which is present in its own form in the drug, as proven by its being capable of extraction without change of its chemical properties. Alkaloids have a definite chemical composition. Most of them are crystallizable, although a few are liquid, e. g., nicotine. Most of them are bitter to the taste, some intensely so. The pure alkaloids, as a rule, are nearly insoluble in water, but their basic character permits the formation of salts that are freely soluble. For example, while cocaine requires 600 parts of water to dissolve it, cocaine hydrochloride is soluble in 0.4 part of water, or 1500 times more soluble than simple cocaine. Therefore, almost without exception, soluble salts of alkaloids are used instead of the simple substances. Double salts also are sometimes employed. Alkaloids usually represent much or all of the activity of the drugs containing them, and it is believed that they exist in the drugs only in combination with acids. This has been proven to be true of many of them, e. g., morphine exists in opium in combination with either sulphuric or meconic acid, i. e., as sulphate or as meconate of morphine; strychnine is combined in nux vomica with igasuric or "strychnic" acid, etc. As a class, we accord alkaloids the preeminence among medicines. Their action is chiefly upon the nervous system, through which they may exert an indirect influence upon other kinds of tissue. They have almost no influence upon elimination, none of them being classed among the cathartics. They are very active agents in comparatively small medicinal doses, and many of them are poisonous to the nervous system when given in large doses. Because of smallness of dose, ready solubility, and the fact that they are not irritating to tissues, as a rule, most of their salts may be used hypodermically. They furnish our most powerful narcotics and anodynes. Two especially, morphine and cocaine, present the danger of drug habit through unguarded or continued use. cinchona, for instance, each yield twenty or more alkaloids. Artificial Alkaloids.- — Besides the large number of alkaloids existing naturally, a number of others have been produced artificially, usually by subjecting a natural one to chemical change. Some of these artificial bodies are valuable additions to the list, as they are found in some instances to have an action quite distinct from that of the original alkaloid. Incompatibility of Alkaloids. — Drugs are said to be incompatible with each other when their mixture results in an undesired physical or chemical change. In using either natural or artificial alkaloids we must have in mind their incompatibility with certain other substances, as given below: 1. JJlth Alkalies. — The basic power of the alkaloids is exceeded by that of the ordinary alkalies, therefore the latter easily decompose the salts of the former. Hence, it may be stated that alkaloidal salts in solution are incomjjatible 7cith alkalies and alkaline carbonates, the mixture leading to precipitation of the alkaloid. The danger here is from the deposited drug, which might be taken in poisonous quantity in the last one or two doses of the mixture. 2. With Tannic Acid.- — Alkaloids unite with tannic acid to form tannates, which are insoluble; therefore, alkaloids and their salts in solution are incompatible with tannic acid or ^^ ith any preparation containing it, the mixture resulting in a deposit of the tannate of the alkaloid.* 3. ]\ith Metallic Salt^. — Certain metallic salts, especially double salts or double iodides, cause precipitation when mixed \A"ith alkaloidal solutions. Lugol's solution also will precipitate the salts from solution. Ptomaines and Leukomaines. — Two other classes of bodies belonging to the group of organic bases, but which are in no sense medicines, should be mentioned here because of their similarity to the vegetable alkaloids. They are ytomaiiies, or putrefactive alkaloids, which are basic substances produced by the action of bacteria upon organic matter, and leukomaines, which are basic substances resulting from normal tissue metabolism. The former are of special interest as contributing to the toxicity of many bacterial diseases, and from the resemblance of certain of them in their action to the vegetable alkaloids. Thus, tetanine, present in the disease tetanus, or lockjaw, produces the characteristic spasms of this disease, which resemble closely those produced by strychnine. Others are narcotic in action, bearing some resemblance to morphine or atropine. ciples which, when decomposed by boiling with acids or alkalies, or by There seein.s to be a contradiction to the above in the fact that a number of vegetable drugs contain both tannic acid and alkaloids, without any 'precipitation occurring in their liquid preparations. The explanation of this is that the alkaloid is present in a natural combination, which is not broken up by the peculiar tannic acid that is its natural associate in the particular drug; or the alkaloid may be in natural combination with the tannic acid. the action of ferments, yield glucose, with some other product peculiar to the substance tested. Some have the chemical behavior of acids, while some resemble resins in nature. nor acid properties. These two classes form a group, some members of which are of great value in medicine. Santonin, aloin, glycATrhizin, amygdalin, digitalin, and elaterin furnish examples. While their uses are varied, the activity of many of them is addressed to the eliminative functions. Especially do we find them in the cathartic drugs. As a class they influence the nervous system less than do the alkaloids, and they are less poisonous. REMEDIES: THEIR CLASSIFICATION AND DEFIXITIOXS. The term remedy includes any agent, of whatever character, employed in the treatment of disease. It may be a medicine or an external force or influence. It may be intended for internal administration, for external application, or for less direct mental influence. Remedies are usually grouped as follows: Preventive remedies, those that are employed to prevent the acquisition, development, or propagation of disease, e. g., vaccination to prevent smallpox, and disinfection to pre^'ent the spread of any infectious disease. this group has attained a rank of first importance. Hygienic remedies, those that conduce to the maintenance of health and of good resistive power against the causes of disease. They include proper food, ventilation, exercise, bathing, etc. This group is closely related to the preceding and, on the whole, stands next to it in importance, it being a sound principle that such natural means of preventing or correcting diseased conditions, when efficient, should be held as preferable to artificial medicinal or mechanical means. in nature, e. g., heat, electricity, sunlight. Medicinal or pharmacologic remedies, the substances administered or applied in the treatment of disease. They are known as medicines. They are intended to directly modify functions, or to antagonize the process of disease, or remove its results. Being material in nature, they form the basis of pharmacology, or the study of the action of medicines. different degrees of action of the same agent in some instances. Demulcent. — An agent that protects or soothes a raw, irritated or inflamed surface. It is usually an oily, mucilaginous or albuminous substance that directly coats over the surface, but it may be an agent that, upon a mucous surface, stimulates the natural secretion, which itself acts as a demulcent. Diuretics may act through the circulation by increasing arterial pressure or modifying the composition of the blood, or by directly stimulating the activity of the kidneys. Antiseptic (General). — An agent that, being absorbed, renders fluids or tissues of the body destructive of, or resistant to the growth of, bacteria or other parasitic bodies. ADMINISTRATION OF MEDICINES. It is a sound principle in medicine that the more nearly a remedial substance can be applied to the point of disease, the more effectual and the safer is its use. In accordance with this, our remedies should be applied locally as far as possible. The site of the disease, therefore, will determine in very many cases the selection of the site, avenue or method of application of a medicine. The urgency of a condition also will demand a choice of method, as an emergency often calls for the most rapid administration that is possible. We recognize various avenues and methods by which medicines are introduced to the system, and these require separate discussion. By the Stomach. — Stomach or mouth administration is the original and common method employed for the great majority of medicines. As the stomach and intestine constitute the natural avenue of absorption of food substances, it is the one that most easily provides for solution and absorption of a medicine, and the one that is most tolerant of the introduction of an unusual substance. It should be noted that absorption is more active from the small intestine than from the stomach; also that fluids begin to pass from the stomach into the intestine very soon after being swallowed. A very soluble drug that requires only a small dose may be placed under the tongue, and absorption follows quickly. Nitroglycerin given in this way will produce its general effect within three minutes. It is, however, a very diffusible drug. Form of Medicine. — The substance employed should be in a soluble condition, or in solution, if intended for absorption into the blood. For local effect in the stomach insoluble medicines are frequently used, e. g., bismuth subnitrate. The reaction of the gastric juice is acid; that of the intestinal juices is alkaline; thus, the solution of any substance soluble in either an acid or alkaline fluid is aided. We find that practically any substance that is even slightly soluble, whatever its form when swallowed, will in time find its way into the fluids of the body; Solution and absorp- tion are sometimes aided by chemical change, as in the case of iron, which is changed to chloride of iron by union with the hydrochloric acid of the gastric juice. Some substances that require an alkaline liquid to dissolve them may pass through the stomach unchanged. This is true of salol, which is insoluble either in water or in an acid liquid. It reaches the small intestine unchanged, where it is soon decomposed and absorbed. Rapidity of effect depends upon soluhiliti/ and rate of ahsorytum. Quinine sulphate given in powder form will require considerable time for solution, on account of its slight solubility except in the presence of a free acid. . It will probably require the secretion of considerable gastric juice to dissolve a full dose of this drug; therefore, when given in powder, an hour or two will elapse before the effect is appreciated. The same drug given in solution will produce its effect much sooner, particularly if it be given when the stomach is empty. The rate of absorption depends somewhat upon the diffusibility of the medicine used, but all of the conditions that modify osmosis have their influence; the activity of the circulation, the state of blood-pressure, difference in specific gravity or degree of salinity between the stomach contents and the blood, and the physical character of the substance to be absorbed, must all have their influence. Fats and oils before they can be absorbed require to be saponified, which change occurs after they pass into the duodenum. Therefore, they are not absorbed at all from the stomach. Among all of the above-named, the one condition modifying the rate of absorption, that is best appreciated and most easily controlled, is the degree of dilution of the drug by the stomach contents which must be absorbed with it. Thus, if the dose be given upon an empty stomach, with only sufficient fluid to ensure its solution and proper dilution, absorption should occur quickly, say in half an hour; while the same dose given after a full meal would require three to four hours for complete absorption, because of its dift'usion through a quart or more of stomach contents which need that length of time for absorption. In the latter case only a part of the dose would be taken up from the stomach, as the contents with which, it is mixed pass gradually into the duodenum, from which absorption continues. It follows that, in order to produce a certain degree of effect, a larger dose will be needed when given ivith a full stomach than if given before a meal, for the degree of effect depends usually upon the amount of the drug circulating in the blood at one time. This amount will be determined by the quantity absorbed within a certain period, minus BY THE BOWEL 43 the quantity eliminated during the same period. With absorption slow and elimination active (the elimination of some drugs begins very quickly), the amount present in the blood at one time may be much less than the amount administered. As a rule, then, medicines will produce their effects with a minimum dose and in the shortest time (one-half to one hour) when given with the stomach empty. But some drugs are too irritating to be placed in an empty stomach. These will require great dilution. This is true of many of the salts, which diffuse easily, as a rule, and may be given with considerable water. Salts as irritating as the bromides and iodides should never be given without first being dissolved and well diluted. When rapidity of action is unimportant, as with tonics and alteratives, we may as well give them after meals; except that bitter tonics, whose action is a local one upon the gastric mucous membrane, should be given ten or fifteen minutes before meals, in order to obtain their best effect. Cathartics are commonly given at bedtime so as to produce their effect at about the time of the usual m.orning evacuation. Saline cathartics form a distinct class of medicines in relation to stomach administration, in that absorption is not necessary to their action. If given in concentrated solution upon an empty stomach their high degree of salinity (high osmotic pressure) will determine a flow of fluid from the blood into the digestive tract with prompt and copious watery evacuations. They are best ^iven in the morning upon arising, as a prompt effect from a smafler dose may be thus obtained than when given at evening after a meal. By the Bowel (Rectum and Colon). — Whenever, on account of inability to swallow or persistent vomiting, stomach administration is impossible, medicines or food may be introduced into 'ths lower bowel. Also for local medication of the rectum or other organs located in the pelvis, as in cases of dysentery or of hemorrhoids, this method may be our first choice. Form of Medicine. — The rectum does not provide for solution of substances to any degree. Therefore, if our object be general medication we must ensure solution of our drug. But if we desire local medication only, then absorption into the general circulation is unnecessary, and, indeed, may be undesirable; so we may have our drug in a condition to be taken up slowly by the tissues, the action being correspondingly prolonged. For general effect a non-irritating solution should be used in moderate or small quantity, so that it may not be expelled. In order to favor retention and absorption, it is advantageous to place the dose high up in the colon. This can be done with a patient in the recumbent posture, by raising the hips above the level of the head. For local effect a solution or suppository may be employed. Rapidity of Effect.^ — For general effect the action of a medicine by rectal administration is slower than by the stomach; but with conditions unequal — i. e., comparing absorption from a full stomach with absorption from an empty rectimi we may have a more rapid effect from the rectmn. It is usually held to be true that the drugs which act upon the nervous system, e. g., narcotics, may be given in a much larger dose by the rectum with safety. This may be due partly to slow absorption and partly to the distance from vital centers of the site of absorption. A safe rule for most substances seems to be that the dose iwr rectum may be twice the dose yer orem. In addition to medication it is common practice, after severe surgical operations, to supply water to the system by rectum. An approved method is the INIurphy method, by which fluid is introduced drop by drop, no more rapidly than the system absorbs it, and continued for hours or even days. Epidermic, uhere a substance is applied to the surface of the skin for the purpose of local medication or of counterirritation. When a s^'stemic effect is desired a similar application may be made, with friction added, to secure penetration into the skin. Thus mercurial ointment is very commonly employed in the treatment of s^-philis. The term inunction is applied to the use of ointments in this way. Endermic, an obsolete method, which consisted in first raising a blister, then, after removal of the epidermis, in sprinkling a medicine intended for absorption upon the raw surface. Hypodermic. — This method has assumed an importance which places it next to stomach administration. For promptness of action and definiteness of dose it is superior to all other methods, in the use of those drugs which admit of its emplo}7nent. Also, on account of rapidity of absorption, the dose may usually be about one-half of the dose by the stomach. The method consists of the introduction of the medicine into the subcutaneous tissue bv means of a small s^sTinge * Contrary to this, it is sometimes stated that strychnine is more poisonous when injected into the rectum than when swallowed. (Potter's Materia Medica, 1901, p. 391.) It is true that adrug absorbed from the lower part of the rectum will pass directly into the internal iliac vein and reach the heart and general circulation without passing through the hver, where its toxicity might be lessened. BY THE SKIN 45 armed with a hollow needle, through which the injection occurs. The pain of insertion of the needle deters from the use of this method for ordinary medication, and the dangers attending the injection, though slight, should require the greatest care in employing it. As a rule, this method "u ill find its place in meeting the following conditions : 3. Inability of the stomach to receive or retain the required medicine. 4. Conditions needing local medication, as in the emplo^mient of cocaine. In dental practice the injection method is well adapted to the need of securing local analgesia in many cases of extraction. A very short needle is here employed and the injection is submucous. The hypodermic and submucous injection methods are limited to the use of soluble, non-irritating drugs. Stimulation, the relief of severe pain and the production of local analgesia comprise the common indications. The freely soluble alkaloidal salts in aqueous solution are well adapted, but alcoholic solutions are irritating. Tinctures are inferior on this account, but they may be used in emergency. Septic infection may be due to lack of sterilization of the needle or of the solution employed. The result is usually formation of abscess. To avoid this danger the needle and syringe should be sterilized (by boiling if possible), and the solution be in boiled or distilled water and freshly made. The injection of air into a vein would cause interference ^ith the circulation through the lungs. The air, being carried to the right side of the heart, would be beaten up with the blood into a foam, by the action of the tricuspid valve. The air bubbles thus formed would not pass through the pulmonary capillaries; hence, the occurrence of embarrassment which might be serious, the condition being known as air embolism. An animal may easily be killed by injecting a moderate quantity of air into one of its veins. To avoid this danger the syringe should always, before injecting, be held with the needle upward, gently tapped so as to dislodge any air bubbles within and cause them to rise toward the needle, and the plunger then gently forced onward until all air has escaped through the needle. The presence of a Httle air in the subcutaneous tissue would usually be harmless, the danger being in the possibility of puncturing a small vein and forcing air therein. With this possibility is connected the next danger, that of overdose caused by thro\\ing the whole quantity of the drug directly into the venous system. Our dose is intended for gradual absorption into the blood during a period of from five to fifteen minutes. If, instead, the whole dose is thrown immediately into the blood current and carried to the central nervous system, without the possibility of free dilution, poisoning may quickly occur. To avoid this accident, it is commonly recommended to insert the needle deeply enough so that it may be withdrawn a short distance, so as to escape any vein that might have been punctured in its course.. Another precaution and, in the writer's opinion, one of greater certainty is to inject slowly and note, at the end of the needle, the accumulation of the injected fluid, which should be easily felt by the finger. If the fluid disappears about as rapidly as it is injected, puncture of a vein should be feared, but if the fluid accumulates with the injection, so that a distinct swelling is felt at the point of the needle, nothing need be feared. With the injection of cocaine into the gums for local effect, the immediate blanching of the tissue about the point of the needle may assure one that the solution has diffused into the tissues. In fact, the danger of forcing the drug into a vein is much less with the usual submucous injection than with the hypodermic, because of the small size of the veins in the mucous membrane of the alveolar region. The Hypodermic Sjrringe. — Many kinds of syringes are on the market. The older style of glass barrel and leather plunger syringe has the advantage of permitting a view of the liquid or bubbles of air within the barrel, but the disadvantage of being less easily sterilized. It also dries out easily unless in daily use. The newer style of all-metal syringe has the disadvantage of allowing no view of the interior, but it has the very great advantage of being easily sterilized by boiling the whole syringe. Glass syringes are now also used, but they require much care in handling. W^ith any kind the needles may be sterilized by boiling, while a thorough cleansing of the syringe with boiled water after each use and frequent washing with 5 per cent, carbolic acid, followed by alcohol, will be sufficient care of the syringe. The needle should be thoroughly sterilized before each injection. How to Give a Hypodermic Injection.— Having syringe, needle and solution sterile, the skin is best cleansed by first scrubbing \Aith soft soap and water, then sterilizing by the application of 50 to 70 per cent. alcoholj 5 per cent: solution of carbolic acid, oil of turpentine, 1:1000 solution of bichloride of mercurj^ or some other equally efficient disinfectant. The hands of the operator should be similarly treated. ]Making sure of the absence of air from the syringe, the latter is held firmly with the right hand while the thumb and first finger of the left hand grasp the skin and raise it slightly at the point selected. Into the prominence thus occasioned the needle should be quickly pushed in a direction nearly horizontal to the surface, and should penetrate to the depth of from one-third to one-half an inch or even more. It may be withdrawn slightly, so as to disengage the point, after which the injection is made slowly so as to avoid too great violence to the tissues by rapid distention, which may be painful. Diffusion and absorption may then be aided by gentle rubbing over the injected area. The site of injection for general systemic efi^ect may be upon any accessible portion of the body, care being taken to avoid any visible vein or the proximity of an artery or nerve trunk; but in case of collapse, when the circulation and activity of absorption are greatly reduced, the injection should be made upon the trunk rather than upon the extremities — i. e., nearer the center of the circulation, so as to secure more rapid absorption. For local effect the site of injection admits of little choice, except to avoid important structures. ^^Tien, however, the injection is for local analgesia the medicine is injected more superficially, directly into and beneath the skin or mucous membrane, the object here being to paralyze the sensory nerve endings, which are more abundant superficial!}'. It is unnecessary to penetrate deeply into the tissue unless a deep operation requires it. A word of caution must here be given regarding the danger of forming the habit of the hj-podermic use of narcotics, especially morphine and cocaine. This particular method of drug addiction is more common than is usually known. The seductive effect of the drug is so quickly induced that the victim readily endures the slight pain of the injection for the sake of the agreeable result. It becomes the dut}' of every practitioner to guard his patient and emphatically himself against this danger. Self-administration of a narcotic in this way is an exceedingly dangerous practice and must never be encouraged. Cataphoresis.- — By this term is meant the introduction of drugs in molecular form into living tissue, by means of the galvanic current. Analgesics and alteratives may be employed for application to a limited area by this method. The positive pole applicator is saturated with a strong solution of the drug and placed directly over the part to be medi- cated, the negative pole being placed indifferently upon the cutaneous surface, but avoiding the more sensitive tissue of the face. The drug is carried from the positive pole into the tissue. This method, with cocaine as the drug, has been used to allay sensitiveness of dentine. Care must, however, be taken not to disturb the pulp by the employment of a strong current — 5 to 10 volts should be the maximum strength for this purpose. It is also employed to anesthetize pulps previous to immediate extraction. Further uses of cataphoresis in dentistry are to carry bleaching agents into the tubuli of discolored teeth and iodine into soft tissues. A current of 25 to 40 volts can be used for bleaching purposes, and also to destroy the pulp of a tooth. It has been recommended to cocainize the tissues about the roots of teeth in order to obtain painless extraction, but such employment of the method meets with little practical success. Intravenous Injection. — In case of emergency it sometimes becomes necessary to inject a stimulating or restorative agent directly into a vein. The agent most used for this purpose is the physiologic or normal saline solution at blood temperature. This is a solution of 8.5 parts of sodium chloride in 1000 of sterile water. It corresponds to the blood serum in salinity, and is used to replace the latter when deficient, after severe hemorrhage or in collapse. The intravenous method has come to be employed rather extensively also for the administration of salvarsan in syphilis and antitoxins in diphtheria and tetanus. The effect of the remedy is much more prompt and efficient when thus injected directly into the circulation. Hypodermoclysis.- — The introduction of a large amount of normal saline solution is most commonly accomplished by hypodermoclysis, or injection into the subcutaneous cellular tissue. From 1 to 2 pints are often employed once or twice daily for a number of days in succession. The indications for its use are great depression from acute disease, hemorrhage and loss of fluid from the system by severe diarrhea. The apparatus employed consists of a gravity- or fountain-syringe armed with a large-sized hypodermic needle. The latter is introduced through the skin of the selected site, usually the lumbar region or underneath the breast, and the fluid is allowed to flow slowly by the force of gravity into the loose subcutaneous tissue. The temperature of the solution should be somewhat higher than that of the blood so as to allow for cooling during the slow injection. BY THE LUNGS 49 By the Lungs (Inhalation). — Only gases, vapors and finely atomized liquids may be employed by inhalation. The method is limited to the use of anesthetics, stimulants, antiseptics and a few volatile antidotes. Although thus limited, it is the most rapid of all methods of medication. The great extent of surface, especially adapted for the absorption of gases, presented in the expansion of the pulmonary tract (estimated at 1000 to 1400 square feet) explains why the action of an inhaled gas or vapor is felt almost immediately. The method is adapted especially to general anesthesia where a rapid and profound effect is needed. For practical use by inhalation a vapor must be non-irritating, except when stimulation is desired. Ammonia is frequently applied by inhalation in case of fainting, in order to stimulate the heart and respiration. It is irritating to the mucous membrane, and by this action it produces reflex stimulation. For the purpose of local medication of the air passages, antiseptics and sedatives are frequently vaporized in connection with steam. Either the steam atomizer may be used, or the drug may be placed upon boiling water, from which the steam is inhaled. The most irritating cough may frequently be relieved by proper medication with this method, while even in pulmonary tuberculosis the local treatment by inhalation is now given an important place. The precise modes of action of all drugs upon the human system will probably never be understood. In the laboratory many medicines exhibit certain exact physical and chemical properties that are constant; and, while a knowledge of these will aid us very much in studying drug actions, their combination with biologic factors in the vital structures of the body brings about results that are \'ariable, often indefinable, and peculiar as to individuals. This topic will not be discussed in theoretic detail; but the simpler and better understood modes of action can be profitably illustrated by examples, if we are careful to remember that any explanation can only be partial in most cases, because the contributory vital factors so commonly defy our scrutiny. Physical Action. — The sunplest kind of medicinal action is that where 2)hysical properties alone are concerned. Glycerin applied to a denuded surface or to a sensitive mucous membrane furnishes an example of such, its primary action being simply the abstraction of water from the tissues, with slight irritation which the loss of ^^■ater occasions. Alcohol has a similar action, although more irritating because of its stronger affinity for water accompanied by coagulation of albuminous matter. The irritation in each case continues until the abstracted fluids have been replaced by fluid from the adjacent tissues or from the blood. This local alteration in the fluid component of the tissues exemplifies a principle of wide application throughout the body; for as glycerin and alcohol abstract small amounts of water locally, so physical factors are also employed in the withdrawal of large quantities of fluid through the channels of elimination. In turn the fluid of the blood is restored by absorption of ingested liquids from the digestive tract or by taking up a certain amount from the tissues. In this way also waste products are removed from the cells of the tissues and in turn they receive fresh nutritive fluid from the blood. Much of this action we must attribute to osmosis, defined to be the property by which liquids and crystalline substances pass through animal meuibranes. This process takes place ELECTRIC ACTION 51 between the cells and their surrounding fluid, as well as between the capillaries and surrounding media, and is essential to the course of medicines as they pass through the body. In emergency, as after a severe hemorrhage, the same principle calls for the hypodermic use of physiologic salt solution in quantity, in order that it may be taken up by the circulation. In the treatment of nearly every disease, this same principle finds some application. Any extensive interchange of fluids is brought about chiefly through the influence of what is termed salt action — i. e., the behavior of saline solutions of different degrees of concentration in relation to the salinity of the serum of the blood, by which a flow of fluid to or from the blood is determined. The process of osmosis, as seen in the passage of fluicfs of different composition tlirough a separating animal membrane, is the most important factor of salt action. Having the blood serum of a certain concentration within the vessels and a saline solution more concentrated without, the osmotic flow will be from the blood to the stronger solution, because of the higher osmotic pressure of the latter; on the contrary, a weaker solution outside of the bloodvessels, because of its lower osmotic pressure, will readily pass into the blood. Thus the administration by niouth of a concentrated solution of a saline cathartic will promptly cause a flow of serum from the blood current into the digestive tract (exosmosis), while pure water taken into the digestive tract would pass into the bloodvessels (endosmosis) . A single drug, potassium bitartrate, may illustrate both exosmosis and endosmosis: For if it be given in form of the salt with very little water it will attract a large quantity of water from the blood and so induce a cathartic effect; but if it be given in dilute solution, it will pass into the blood and be carried to the kidneys to be eliminated, where its action will be diuretic. Any solution that is indifferent in osmotic action — i. e., having the same osmotic pressure as the blood serum — is called isotonic, one of higher osmotic pressure being hypertonic and one of lower osmotic pressure being hypotonic. The salinity of the blood is imitated in the physiologic saline solution containing 0.85 per cent, of sodium chloride, which is used hypodermically, intravenously, or by the bowel, as a restorative. Electric Action. — Passing from purely physical influences, we recognize also electric relations in the action of many substances. It has been ascertained that most acids, bases and salts, when in dilute solution, as in the blood and tissues, are dissociated into ions of their elements or radicals, that these are charged with positive and negative electricity, 52 MODES OF ACTION OF MEDICINES and that the solutions are capable of conducting electrical currents. The ions do not usually act as the pure elements; in fact, they often exhibit entirely different properties; e. g., in the dissociation of sodium chloride, the chlorine, which in its free state is a poisonous gas, does not act as such, but as the electronegative chlorine ion, while the sodium, which in its free state is an irritant base, in the ionized form is non-irritating and provides one of the most abundant constituents of the body. The practical relation of ionization to the use of drugs is important, as may be illustrated by the use of iodide of sodium or of potassium. Here the element iodine, which in a free state could be given only in small quantity because of its irritating quality, may be given in a 35-times larger dose without unpleasant effects. The combination w ith the base renders the iodine less irritating and the subsequent ionization in dilute solution, as administered, permits its wide diffusion through the body in form of the iodine ion, which is comparatively non-irritating. Little can be said of definite electric reactions as a part of drug action within the tissues. In fact, with most drugs it is impossible to fully separate the physical, the electrical and the chemical factors, blended as they are in the life action of the cells. Chemical Acticn. — The chemical features of drug action can be very clearly demonstrated for certain substances of local use. In the tooth structure especially, where the vital factors are slight, about as definite chemical reactions can be obtained as in the laboratory. The science of bleaching teeth rests upon this fact, and thorough disinfection by chemical means is made possible. But also in the softer structures that possess greater vitality, the chemical reactions of drugs locally applied are often very evident, e. g., the coagulant action of phenol and the corrosive action of strong acids and alkalies. These reactions and their chemical basis are more fully discussed in the chapter on Escharotics. A special line of medication where the action is purely chemical is the application of chemical antidotes in cases of poisoning. Secondary Effects. — With many drugs we observe both primary and secondary efl'ects. The secondary is more likely to be the desired or therapeutic effect, or to lead to it. To illustrate: The application of an irritant (tincture of iodine or mustard paper) to the gum to relieve toothache, will first cause irritation (primary effect), then alteration of circulation in the region will follow (secondary effect) and, pressure being thereby equalized, we have relief of pain (therapeutic effect). undesirable. In the use of simple irritants and astringents we observe some of the reactionary effects of drugs. When we speak of irritation we mean a disturbance of tissue, or a reaction to a disturbance, inflammation is a reaction of higher grade having, as a prominent feature, a local increase in the number of leukocytes (leukocytosis), which becomes general in an inflammation of any severity. This condition really represents a reactive increase in the protective and reparative resources of the blood and tissues, which may be an important factor in securing relief. The action of an irritant drug in the vicinity of an inflammation (counterirritation) is believed to stimulate absorption by the lymphatics as well as a local increase of leukocytes. Thus the vital factor within the tissues aids in securing the therapeutic efl^ect, and it may even influence the primary action of the drug. This factor is so variable that for most medicines the sum of the effects can only be learned by experience, and even then individual peculiarity (idiosjoicrasy) may determine unexpected results. Medicines intended for general systemic effects have a more obscure action, which can usually be judged only by the clinical results observed. In general, we may say that stimulants and sedatives m^wervce functions chiefly and their action is temporary; while alteratives and restorative tonics influence the structure of tissues by entering into the composition of the cells, their effects being accordingly more permanent. Stimulants may irritate tissue primarily, inducing stimulation reflexly, or they may cause more rapid or more powerful discharges of energy in functional activity of the organ stimulated. Sedatives depress functional activity, usually by direct influence upon nerve tissue, and they easily cause poisoning in very susceptible persons. A more detailed discussion of the action of stimulants, sedatives and alteratives is given in the separate chapters devoted to them. Untoward Effects. — All undesired results of drug action, whether simply unpleasant or positively dangerous, are known as untoicard effects. For example, the pain incident to a blister, the nausea caused by some drugs given for other purposes, the constipation and headache following a full dose of opium and the depression caused by many pain-relieving agents, are all classed under this term. No small part of the prescriber's art lies in securing the desired, and avoiding the untoward, effects of his remedies. Protective Reactions. — It is well kno^ii that the blood possesses, in some degree, protective properties against certain toxic substances; and one of the important developments in therapeutics has been the discovery that the protective resources may be increased by medication of a peculiar kind, or added to artificially. This involves the question of securing immunity or the production ^^■ithin the body of antibodies that are antagonistic to the germs of particular diseases. The means •of securing this end differ somewhat with different diseases. Thus, immunity against smallpox is positively attained by inoculation with the living virus of the cowpox; while immimity against t\73hoid fever is secured by the injection of a hacterial vaccine or baderin, which is a preparation of killed bacteria of the kind which causes the disease. Vaccines are also employed in prevention and treatment of other bacterial diseases, the principle being that of stimulating within the body the formation of bodies that are antagonistic to the cause of the disease. We are dealing here with a protective reaction on the part of the tissues of the body, the process being a. natural one under the conditions induced. Antitoxins.- — In some of the infectious diseases the blood reacts to the toxic products of the disease and develops an antitoxic body, which directly neutralizes the poison and determines recovery in favorable cases. This fact is made use of in the treatment of diphtheria and tetanus particularly. A strong antitoxin, which can be specific for the one disease only, is developed in the blood of a domestic animal, the serum of which is then kept in a preserved state for use when needed. When a diagnosis of diphtheria is made, this antidiphtheric serum is injected hypodermically or intravenously as early as possible, with the result commonly that the poison of the disease is perfectly neutralized. Antitoxins, being natural products of the blood, are harmless and may be used in strong dosage. Phagocytosis. — The protective resources of the body include also the white blood cells, or leukocytes, which increase in number greatly in most fe^'ers and infections. Aside from their function of repairing tissues, they have the power to destroy bacteria in the blood (phagocytosis) and thus they form a very important part of the body defenses. In this relation they are called phagocytes. DEPLETIVES. Depletive measures are those employed to abstract blood or serum from an inflamed or hjqDeremic area, usually with the purpose of relieving pain or pressure. The indications for their use are: passed quickly into the cup immediately before applying, is the means commonly employed to exhaust the air. The vaciuun permits the skin and underlying tissue to bulge into the glass and to become congested with blood. In this way, with each cup nearly or quite a tablespoonful of fluid may be drawn from deeper tissues to the skin and just beneath it. With the emplo\-ment of a number of cups a very decided influence upon a deeper-lying inflammation is noticed, but no fluid is removed from the body. This method is of great value in conditions of pulmonary congestion or pneimionia, and a number of cups may be applied, and repeatedly, to the surface of the chest. The cups cannot be applied upon an irregular surface. Wet cupping is accomplished by applying the same principle after first scarifying a limited surface with an ordinary lancet, or with the especially adapted spring lancet. The cup can then be a])plied as in dry cupping, or a special cup with an exhaust s\Tinge attached may be used. The latter permits of a more constant vacuum being maintained. The vacuum allows a free flow of blood into the cup. By this method a considerable quantity of blood may be abstracted from any part of the body. Scarification with a lancet is the method of depletion most commonly used in dental practice. The indications are hyperemia, inflammation, passive congestion, and local poisoning, as by arsenic. After scarification, bleeding may be encouraged by holding warm water in the mouth, while cold water will tend to lessen the flow. The precautions to be observed in scarification are: Strict asepsis, guarding against too extensive a wound by a sudden movement on the part of the patient, and avoiding the proximity of vessels, nerves, or of Stensen's duct opposite the first superior molar. Lancing of the gums over advancing teeth is called for when unusual hyperemia or swelling is present, or where general irritability, fever, or convulsions point to a local irritation which is found in an abnormal eruption of the teeth. It must be borne in mind, however, that sources of irritation may exist in other parts of the digestive tract, and that in a dentition which is progressing normally there is seldom any need of scarifying the gums. When employed, the incision should be directly over the advancing margins of the teeth. VENESECTION OR PHLEBOTOMY 57 for the relief of acute inflammation or congestion. For use in the mouth it is not generahy applicable, on account of the aversion, on the part of some people, to having a leech in the mouth. Nevertheless, it is to be considered among the best means, and if employed with a leech tube so that it does not touch the tissue except by its sucker extremity, the objection is minimized. The leech tube is of glass, of a proper size to admit the leech and allow its distention by blood. It is dravMi to a narrow opening at one end. This smaller opening should be large enough to permit the passage of the smaller end of the leech by which it makes suction. Swedish leeches are mostly employed on account of their large size, their capacity for abstracting blood varying from one-half to two fluidrachms (2 to 8 mils). If the leech does not bite readily it may be advisable to make a puncture with a fine point at the selected place, in order to obtain a small drop of blood upon the surface. This will usually induce the leech to bite. The suction may be interrupted at any time by sprinkling a little salt upon the leech, when it will drop off. The leech bite is V-shaped and clean cut. Bleeding may continue for some time, and may even require the use of strong styptics or pressure in order to check it. When applied to the skin a small triangular scar invariably remains from the leech's bite, therefore, when used upon the face or neck, the point of application of a leech should be where the scar will not be noticeable, as under the chin, behind the ear, at the angle of the eye or nose, within the hairy region, or at the site of a natural wrinkle. As related to all means of local bleeding it must be borne in mind that the hemorrhagic diathesis {hemophilia) is an absolute contraindication to their emplo}Tnent. Venesection or Phlebotomy .^ — General bloodletting is accomplished by opening a vein (usually the cephalic, just at, or above the bend of the elbow). This therapeutic measure was much abused in earlier years, and the natural reaction resulted in its almost complete abandonment. At the present time, however, it is often employed as an emergency procedure, in cases of severe toxemia or physical embarrassment of the circulation. A pint or more of blood may be drawn. The flow is easily stopped by the simple pressure of the dressing applied. In order to find the A^ein readily and to secure its distention and consequent free flow of blood, a bandage is first placed around the arm just below the shoulder and drawn tightly enough to obstruct the venous return, but not to interfere with the arterial flow. This causes a fulness of the vessels of the arm and great distention of the veins. The median cephalic is then exposed with aseptic care and the opening made with the ordinary sterile lancet. General depletion is also secured by means of sweating or by free catharsis. In either case it is possible to withdraw from one to three pints of serum from the circulation within a short time, which result may be a considerable factor in lessening a local hyperemia or inflammation. Sweating is most readil}^ induced by the hot-air bath, taken either sitting (cabinet bath) or lying down (hot-air bed bath). The hot mustard foot bath also is efficient, adding to the sweating the derivative rubefacient effect upon the lower limbs. salines are most commonly used. When given in concentrated solution (hypertonic, see p. 51) upon an empty stomach, they act promptly by causing a copious flow of serum from the bloodvessels into the digestive tract, followed by evacuation without much irritation. The state of blood-pressure modifies their activity somewhat, a fulness of the circulation favoring an outward flow of serum. A low blood-pressure would require salines to be given in larger quantity for the same desired result. The vegetable hydragogues are, as a rule, more violent and drastic in action, because they irritate the bowel and greatly stimulate peristaltic action. Jalap is milder than others, and very efficient when simple depletion is desired, and it may be used daily for some time; but when a revulsive action is wanted the more irritating croton oil is used. General depletion, as above, is indicated where there is accumulation of serum in a serous cavity, as the pleural or peritoneal, or where cardiac or hepatic disease is attended with marked venous congestion. COUNTERIRRITANTS. CouNTERiRRiTATiON means the production of an irritation in a normal part of the system in order to influence a diseased part favorably. The irritant is usually applied to the skin, but it may be applied to the mucous membrane of the mouth or to other accessible mucous surfaces. The action varies in degree from a simple reddening of the skin, by increase of the circulation locally, to a destruction of the superficial layer of tissue. According to the degree of irritation following their application, the agents are divided into: The same agent may be a rubefacient, a vesicant or a caustic, as determined by the strength and duration of its application. This may be illustrated by the application of heat to the skin. Moderate heat will cause a dilatation of the cutaneous bloodvessels, with a decided hyperemia (rubefacient effect); a higher degree of heat will determine the escape of serum from the engorged vessels to the extent of lifting up the non- vascular epidermis (vesicant effect); and a degree of heat that will burn will cause destruction of the skin (escharotic effect). Agents will be selected, therefore, for the degree of effect desired. While some of them will produce any of the above effects, others are more limited and fall naturally into only one class. Thus, arsenic acts slowly, and it cannot be said to produce any typical effect other than escharotic; capsicimi usually produces only a rubefacient effect. It must be noted, however, that the thickness and texture of the skin will cause a difference in effect, from the same application, in different individuals, and in the same person upon different parts of the body. A thin, tender skin will blister much more easily than a thick, tough one. It must also be noted that the same irritant will have a much severer effect upon the mucous membrane than upon the skin, on account of the softer and looser texture of the former; e. g., tinctme of iodine by a single application will only irritate the skin slightly, but it will quickly corrode and destroy the superficial layer of a mucous membrane. The severer degree of counterirritation (i. e., blistering) should be avoided both in childhood and in old age, because of the greater susceptibility to irritation and the lower vital resistance at the extremes of life. a counterirritant in typical conditions: 1. If an inflammation is quite superficial, the counterirritant should be applied at a short distance. If applied immediately at the i)oint of inflammation, the latter may be aggravated. applied back of the ear, beneath the chin or upon the back of the neck. Modes of Actio7i of Counterirritants. — The remedial effect of a counterirritant is probably brought about by a threefold action. They influence: (1) The circulation; by causing a hyperemia through vasodilation at the point of irritation the tendency of the blood supply will be in that direction. (2) They turn the attention of the system toward the new point of irritation and a\\'ay from the disease, partly a mental effect. (3) They influence the innervation of the diseased part by the reflex influence of the irritation. In the sum of their effects they stimulate the movement of fluids within the tissues; hence, they are regarded as l\inphatic stimulants and are often employed to stimulate the absorption of serous or inflammatory exudate. The terms derivative and revuhive are often applied to the action of counterirritants, the latter of the t"v\o referring especially to a very decided action, as in the prompt and violent effect of croton oil as a cathartic, \\hen given to relieve a cerebral condition. Heat.^ — This agent has an important place as a counterirritant, because of the readiness and variety of forms in which it can be applied. The hot-water bag, dry and moist poultices, hot foot and sitz baths, the hot iron, the thermocautery and the galvanocautery indicate the range of methods and effects that attach to the use of heat. The irritant drugs, other than escharotics, are here discussed in the order of their severity, beginning with the mildest. Escharotics are considered in a separate chapter. Preparations and doses: Oleoresina capsici, gr. \| (0.03 gm.). Emplastrum capsici — external use. Tinctura capsici, lU 8 (0.5 mil.). The most irritating preparation of capsicum is the oleoresin, which is seldom employed undiluted. The tincture may be applied to the mucous membrane in sluggish or atonic conditions. It acts by irritating, and thereby inducing a more active local circulation. Diluted with water, it may be used as a wash or gargle. The official plaster is prepared by spreading the oleoresin upon resin plaster. It is used as a counterirritant to the skin or, in a limited area, to the gums, as in the beginning of pericementitis. The powdered driig is likewise recommended as a dental counterirritant. To limit and concentrate its action it must be enclosed in a small sack, and in this way it may be combined with other drugs if desired. Emplastrum sinapis {mustard paper) — external use. Oleum sinapis volatile, TH, \| (0.008 mil.). Powdered mustard (as emetic), 32\| (10 gm.). These two drugs are similar as to constituents and uses, although the black is the more powerful and claims our chief attention. Mustard in a dry state is not irritating, but the black mustard seed contains a glucoside, sinigrin and an enzyme, myrosin, which, in the presence of water, react to form the very irritating volatile oil {oleum sinapis volatile). Myrosin in aqueous solution coagulates at 140° F. (60° C); therefore, a temperature of that degree or higher will prevent the development of the volatile oil. Alcohol and acids also interfere with its production. Water at ordinary temperature is the agent to use to develop the valuable constituent of the drug. Taken internally mustard is an excellent emetic, the effect being due tc its irritation of the stomach. In case of poisoning by opium or arsenic, or, in fact, by any except the most irritant poisons, if the case is seen early while the poison is still in the stomach, a tablespoonful of mustard stirred up in a glass of water and taken at oime is a most efficient emetic. Mixed with enough water to form a paste, mustard is applied between two layers of muslin to produce quick and moderate counterirritation, which, if prolonged, may proceed to vesication. For a continued rubefacient effect, the mustard may be diluted by mixing with from one-fourth to half as much flour before adding water. A mustard plaster or poultice thus prepared is called a sinapism. The irritant power of this drug makes it a valuable addition to the hot foot bath. Here the mustard is to be stirred up in cold water, and the mixture allowed to stand for several minutes, then added to the hot water for the bath. In the treatment of pericementitis or other active inflammation in the upper part of the body, the hot mustard foot bath, carried to the point of thorough relaxation and sweating, is a valuable general measure. In similar conditions of inflammation about the face or mouth a mustard plaster may be applied to the back of the neck. A preparation of some value to the dentist is mustard paper (Emplastrum' sinapis) , in which powdered black mustard, freed from fixed oil, is mixed with a solution of india-rubber, and spread upon paper or upon cloth. Protected from moisture, mustard paper will keep indefinitely, and it may be found at any time ready prepared in the stores. For local blistering of the mucous membrane in the treatment of pericementitis, it is cut into small squares or other suitable shapes and applied directly to the gum over an offending tooth. The moisture of the mouth will cause the volatile oil to develop ciuickly. It is very convenient also for more extensive irritation upon the surface of the body, but when used upon the skin the plaster must be moistened with water before application, so as to secure the reaction which develops the oil. Volatile oil of mustard may be used as an irritant, by being applied pure for limited effect, or diluted with alcohol for extensive effect; but it has a very rank odor which is objectionable. Crude turpentine is the solid oleoresin, or pitch, which exudes from the pine tree when the bark is cut. By distillation it is separated into the volatile oil of turpentine and a solid residue called resin or rosin. The oil is colorless, with a characteristic odor and taste, which become stronger and less pleasant with age and exposure to air. It is soluble in 5 parts of alcohol and in 1 part of glacial acetic acid. For internal use the rectified oil is preferred. It is neutral, while the commercial oil may be slightly acid. lODUM 63 if used full strength. The ofRcial liniment (35 per cent.) may be used, or a turpentine stupe employed. The latter is prepared by wringing a piece of flannel, about twelve inches square, out of very hot water, then distributing from ten to thirty drops of oil of turpentine upon it. It is then quickly spread out, while still hot, upon the surface to be treated, and covered with several layers of fabric. This may be renewed frequently so as to keep up a constant rubefacient action. This drug is a useful general antiseptic, and it may be used to cleanse instruments or disinfect the skin, but the odor is objectionable to some. It has been employed as a local antiseptic, but is not used in dentistry to any extent; the old oxidized oil may be used as deodorant in moist gangrene of the pulp, to destroy the extremely unpleasant odor. It does not coagulate albumin, so that except for its unpleasant odor it might be an excellent penetrating antiseptic. In poisoning by phosphorus this drug has long been regarded as a valuable chemical antidote, if administered while the poison is still within the digestive tract ; but this is true only of an old, highly oxidized oil, tne old, French oil being most valuable. Fresh oil of turpentine will dissolve phosphorus and must, therefore, be avoided. and in contact with a mixture of nitric and sulphuric acids it will ignite. lodum. — Iodine [I]. — ^A solid non-metallic element, found in sea-weeds and in natural mineral compounds, its chief commercial source being sodium iodate, obtained in Chili. The drug is seldom used internally except in form of iodides. Preparations and doses: Liquor lodi compositus, Lugol's solution, (5 per cent.), TU 3 (0.2 mil.). Tinctura lodi (7 per cent.), m H (0.1 miJ.). Unguentum lodi (4 per cent.), external use. See also Iodides. All of these preparations contain potassium iodide. Pure iodine occurs in bluish-black, rhombic plates, having a penetrating odor and sharp taste. It is slowly volatile, soluble in 12.5 parts of alcohol, in 80 parts of glycerin and freely in ether; also soluble in an aqueous solution of potassium iodide, although nearly insoluble in water.* These solutions are brown in color, while chloroform and carbon disulphide each dissolve it with a violet color. * Iodine is soluble in about 3000 parts of water. According to the U. S. Dispensatory, eighteenth edition, its solubility in water may be increased, not only by potassium iodide, but by sodium chloride, ammonium nitrate and, to some degree, by tannic acid. The official tincture now contains 5 per cent, of potassium iodide, which renders the solution miscible with water in any proportion without precipitation. Iodine in the form of the tincture is an irritant of great vahie, as appHed either to the skin or mucous membrane. Upon the latter it should be used only to a limited extent, as it will quickly corrode the superficial layer. As a counterirritant to the gum in pericementitis, or irritated or inflamed pulp, it is invaluable. Iodine is a penetrating agent, although the alcohol in the tincture will coagulate albumin slightly. In common with other irritants it has the power to stimulate absorption by the Ijinphatics, ^^"hich is regarded as a valuable part of its local action. The great advantages possessed by the tincture are promptness and limitation of its action. The alcohol ciagulaies the tissue, thus limiting action, and the excess evaporates quickly, leaving a dry surface. Where coagulation is a disadvantage, or where the action of alcohol is not desired, the compound solution may be used, but it is slightly weaker than the ordinary tincture. Churchill's tincture (X. F.)* is much stronger than the official tincture, and is too irritating for application to the mucous membrane. The favorite combination of equal parts of tincture of iodine and tincture of aconite may be used more freely, as in it the iodine becomes diluted and its irritant action counteracted somewhat by the aconite, which is a local sedative, t The brown stain produced by iodine makes it objectionable to use upon a visible surface, and it should never be used within a tooth, for fear of permanent staining of the dentine. Stains upon the hands or upon fabrics are easily removed by water of ammonia. As an antiseptic and disinfectant, iodine is very efficient. The tincture diluted with an equal part of alcohol is used to sterilize regions to be operated upon in the mouth as well as elsewhere. The use of strong solutions in the mouth, except as a counterirritant, is to be Note. — Boulton's solution (Liquor iodi cirbolatus, N. F.) is a time-honored and generally useful combination of iodine and phenol, much weaker than the official preparations of iodine. Its formula is: condemned, on account of its destructive action on the tissues. Upon the skin the tincture may be used in full strength. It may be applied in strong solution to ulcers, but is quite painful. For cleansing abscess cavities the tincture or the compound solution may be used somewhat diluted, either applied upon cotton or injected carefully. It may also be carried into the tissues by cataphoresis, by which method it is very useful in treating pericementitis, pericemental abscess, and especially the affections of the pericementum that follow influenza (Hofheinz). Mixed with albumin. Most severe irritant; cor- \| Immediate coagulation due rodes mucous mem- ; chiefly to the alcohol brane superficially and present, promptly. present. The tincture may be combined with carbolic acid, which, with full strength of each, increases the corrosive and coagulating action. Equal parts, or any desired variation from this, may be used. Such mixture diluted with alcohol or glycerin is a proper application to abscess cavities, ulcers, unhealthy gums in stomatitis, etc., as it will combine disinfectant, irritant and indirectly stimulant properties. ^Yhen properly diluted the carbolic acid may contribute a local sedative effect. solution. Such dilution is a very great advantage in some of the uses of the tincture. Iodine has a reputation as a stimulant to absorption by the hinphatics, in common with almost all counterirritants and alteratives, with the advantage that it belongs to both of these classes. To influence the absorption of indolent swellings or to reduce enlarged l}Tnph nodes, either the tinctiue or Lugol's solution may be applied (the tincture possessing the very great advantage of drying quickly), although after a number of applications the skin becomes blister^ or broken, when their use becomes very painful. A better preparation for continued use is the ointment (containing 4 per cent, iodine and 4 per cent, potassium iodide), which may be applied daily, with friction to aid absorption. Decolorized tincture of iodine,* so called, is less irritating and less efficient than the other solutions, but it may be applied where the color of the latter would forbid their use. It does not dry readily upon the skin, which is an objection to its employment. IncomimtihiUty . — Free iodine is incompatible with starch, forming the blue iodized starch; with oil of turijentine, mixture with which may be followed by violent reaction. Internally the drug is used mostly in the form of iodides, for the reason that these salts are much less irritating and therefore permit a much larger quantity of iodine to be taken. As an alterative it will be further discussed in the chapter devoted to that class of remedies. Oleum Tiglii. — Ceoton Oil.^A fixed oil expressed from the seed of Croton tiglium, a small tree indigenous in India. A brownish-yellow oil, soluble in 60 parts of alcohol, becoming darker and more soluble with age. It has an unpleasant, fatty odor and an acrid taste. Croton oil is an irritant, whether applied to the skin or taken internally. When rubbed into the skin it acts slowly, producing in from twelve to twenty-four hours a crop of small vesicles, which are distinct and separated from each other. If undisturbed, these dry without breaking. The counterirritant effect is pronounced, with much less discomfort than from cantharides. The drug may be applied back * Tinctura iodi decoJorata (N. F.) is prepared with the aid of sodium thiosulphate and stronger water of ammonia. Because of the chemical change attending the decolorization, it contains no free iodine, but is a variable mixture containing chiefly ammonium iodide. CANTHARIS 67 of the ear in treatment of severe or chronic inflammations about the face or mouth. It should be rubbed well into the skin. It may be mixed with equal parts of tincture of iodine for combined effect, but about the head it will generally be used alone. Internally the oil is a drastic cathartic, poisonous in very moderate quantity, thirty minims (2 mils.) ha^'ing caused death. In the usual dose of one-half to two minims (0.03-0.12 mil.) it irritates the intestinal tract, producing purging in from one-haK to two hours. On account of its prompt action it is often given for revulsive effect in cases of cerebral hemorrhage or inflammation, and in uremic poisoning. Care must be taken in handling croton oil, and it should never be tasted. Cantharis. — Caxthaeides (Spanish Flies).— The dried insect, Cantharis vesicatoria. Obtained in various European countries, the large Russian flies being preferred. Average dose of tincture, mil (0.10 mil.) As a counterirritant, cantharis is used in the form of the cerate applied as a plaster to the skin (Emplastrum cantharidi.s) , or the cantharidal collodion, which is applied as a varnish. The cerate produces in about twelve hours a single blister, the full size of the application, painful, and gi"ving a maximum of counterirritant effect. Seldom should a space larger than one by three inches be covered. Either the surface of the plaster or the skui should be oiled before applying, to ensure acti^'ity of the irritant principle cantharidin, which is soluble in oils. The cantharidal collodion may be used instead of the cerate for ordinary application. It is believed to be safer, and it is much more convenient. It is applied as any other collodion, dries quickly and requires no dressing until the blister is formed. There is some danger of absorption of the active principle, cantharidin, to avoid which the application should be as limited as possible. Irritation of the genito-urinary tract will be the first symptom of its poisonous general effect. The drug is reputed to be aphrodisiac in effect, but any sexual stimulation is due to irritation and is only one symptom of general poisoning, for cantharis is an irritant poison if taken internally in excessive dose. The tincture is the preparation for internal use, but it is seldom employed. tant local action. This action is secured best when the vapor is confined. The " thimble blister" is a convenient form of counterirritation when it is to be limited to a single point. It is produced by placing a bit of cotton saturated with chloroform in an ordinary thimble and apjilying it closeh' to the skin for five to ten minutes. Treatment of Blisters. — Bearing in mind that the healing of injured tissues is always a natural process, and that any application is to be regarded only as an aid, the simpler we make the treatment of blisters the better. This involves the simple principles of the treatment applied to burns, which may be stated as follows: 3. Stimulation of repair. The first is self-evident and requires only the simple statement that, as simple cleansing applications, any but the mildest antiseptics should be avoided. Boiled water, normal salt solution, and sterilized oils or fats answer the purpose of cleansing a blister in most cases. In the absence of infection it is unnecessary to disturb the blister often, if proper protection is employed, as the natural process of healing may be disturbed by the daily removal of dressings, particularly when they adhere. Usually, when we are sure that the blistered surface is clean and aseptic, we can assume that healing will progress without interference. It is only in case of septic or unhealthy conditions that frequent treatment or strong applications may be needed. The second is accomplished by the use of a demulcent such as a sterile oil or fat, or by any non-irritating protective agent, and the api)lication of a dressing that will exclude the air. The contact of air is usually painful from its drying effect, and it presents also the danger of infection of the open sore. Carron oil* is a time-honored application to burns and blisters, but an objection to its use is the fact that the drying of the linseed oil contained in it makes the dressing hard and often difficult to remove without disturbing the sore. The third applies chiefly to large blisters that heal slowly, and includes such measures as the application of poultices of brewers' yeast, which is a most excellent cleansing and stimulating agent, f * lAnimenlum cnlcis, composed of equal parts of linseed oil and lime-water, t The great value of brewers' yeast in cleansing and stimulating repair of indolent and foul ulcers is believed to be due to the nuclein developed by the yeast plant. TREATMENT OF BLISTERS 69 When healing is much prolonged and hindered by the development of excessive granulations (proud flesh), the latter may be removed by a mild caustic, such as burnt alum, or scraped away. Such removal will often be followed by more rapid healing. The last resort is skingrafting, which consists in transplanting pieces of normal skin from some other part of the body upon the denuded surface, after proper preparation. This will usually be successful in securing a satisfactory epithelial growth, with the usual cicatricial healing of the surface. ESCHAROTICS. Many attack the tissue immediately and are, therefore, called corrosives. . It will be noticed that nearly all agents of this class are strong chemicals; that is to say, they are known and characterized by j^owerful chemical affinities. And this fact serves to explain why they are nearly all corrosives. They have so great affinity for one or more constituents of the tissues that they destroy the organic structure in order to satisfy it. It is further noted that they all differ somewhat in their effects upon tissue. This is explained by their difference in chemical affinity.* Thus carbolic acid has a strong affinity for albuminous matter; it cannot corrode deeply because the firm coagulum immediately formed prevents its penetration. Caustic potash, on the contrary, has no affinity for albumin, forms no coagulum, but penetrates deeply into the tissue, displacing weaker bases from their combinations. It also possesses an affinity for water. These affinities suggest the antidotes in case of poisoning by each. The antidote to carbolic acid will be albumin, that to caustic potash a dilute acid. The strong acids and alkalies are prominent, forming groups that are typical as to the nature and action of corrosives, but they are not usually the agents of choice because of the severity of their effects. In the grouping that follows, chemical similarity, rather than similarity of action, is made the basis. This facilitates the study of chemical antidotes, which apply as well to groups as to individual substances. Some agents that cannot be thus grouped are considered in an unclassified list and their chemical relations studied separately. at intervals upon the albumen a drop of each of the mineral acids, of phenol, and of caustic soda or potash. Note that the alkali does not coagulate; the acids and the phenol do, but the coagula formed differ in firmness. Applied t-o living tissue mineral acids all coagulate alhumin, but nitric acid more firmly than the others.* Sulphuric acid has also a marked affinity for water, and is accordingly the most powerfully corrosive, producing an effect very similar to an ordinary burn. They all have so great an affinity for bases that they disorganize the tissues in order to combine with them, hence their extremely poisonous effects. The strong mineral acids are seldom applied to the mucous membrane because of the severity of their action. Upon the skin they may be applied directly to warts, for the removal of which a few daily applications usually suffice. For this purpose nitric acid is preferable, because slightly less severe in action than the others. These acids are caustic to bone as well as to soft tissues, on account of their power to dissolve the earthy salts of bone. Accordingly, nitric acid has sometimes been applied to small foci of carious bone which were not accessible for removal. Its action may be checked at any time by the use of a weak alkali, such as sodium bicarbonate solution or lime water, which should be injected forcibly, so as to ensure the antidotal reaction at the point of the corrosive action of the acid, which may be at some depth. Employing in dental practice the solvent power of these acids upon mineral salts, they are sometimes applied, slightly diluted, within a small root canal to aid in enlarging the same. They act more rapidly upon partly decomposed than upon sound dentine. In fact the normal tooth structure seems to be little affected during the ordinary time of application; however, when the action has proceeded as far as is desired the acid should be completely neutralized. The range of strength of sulphuric acid, as mostly employed, is 20 to 50 per cent., depending upon extent of action required. Caution should be used to prevent its passage into the periapical region, for there are further discussed under the heading of Restorative Tonics. Poisoning by Mineral Acids. — When a strong mineral acid is used for any purpose, it must be borne in mind that it is a dangerous substance, and great care must be exercised to guard against poisoning. The bottle should be labeled with a poison-label, such as pharmacists are required to place upon all powerful poisons. The dentist also should have a ready knowledge of first treatment in case of poisoning; for any treatment, to be of use, must be employed very promptly, or a fatal result may be expected. In the presence of a case of poisoning by a strong mineral acid, it is not essential to know just which acid has been swallowed. The important facts upon which to proceed are: (1) that the corrosive action depends chiefly upon the concentration of the acid ; and (2) that the affinities of the whole group are so nearly identical that the same antidotal treatment will apply to all. The first and most important thing to do is to dihite the poison freely by large draughts of water. This will remove the danger of further corrosion, and, as water is always at hand, it can be employed immediately. The use of a chemical antidote must be secondary, because of the time usually necessary for its preparation, during which serious damage is being done by the corrosive poison if undiluted. But after free dilution the chemical antidote should be given, so as to completely neutralize the poison. An alkali \^ill be selected, diluted if at all irritating, and given freely. Lime-water and magnesia are preferred to a carbonate, because the latter will, in reaction with the acid, give off a large quantity of carbon dioxide gas, which may cause painful distention of the stomach and even endanger its corroded wall. In emergency, soap, or plaster scraped from the wall, may be given. Vomiting generally occurs, and washing out of the stomach is facilitated by the early dilution with water as recommended above. The use of emetics or the stomach tube is open to question in these cases. Since the neutralization of the acids with simple alkalies results usually in harmless products it seems unnecessary to further irritate the stomach. Later treatment will comprise the use of demulcents, anodynes and stimulants. (See Table of Poisons and Antidotes.) The fact that poisoning by strong mineral acids is usually fatal, demands that emphasis be placed ui)()n immediate treatment, as outlined. Organic Acids. Acidum Acetum Glaciale. — Glacial Acetic Acid [C2H4O2]. — Nearly or quite absolute acetic acid, being not less than 99 per cent. It is liquid or crystalline, according to the external temperature, its meltingpoint being a little below 60° F. It is colorless and has a strong vinegar-like odor and a sharp acid taste. It is not a coagulant, but, on the contrary, is a solvent of albuminous and fibrous tissue. It is employed only as a caustic and to soften callous tissue. It is not used internally. Acidum Trichloraceticrm. — Tkichloeacetic Acid [C1HO2CI3]. — It should be not less than 99 per cent. Obtained by oxidation of chloral hydrate with fuming nitric acid and subsequent distillation, it occurs in colorless crystals that are very deliquescent. It is soluble in 0.1 part of water and very soluble in alcohol and ether. Either in crystals or strong solution it is used as a caustic to remove redundant tissue, as overhanging gums, warts, etc. It coagulates albumin, and may be employed as a test for that substance. A 20 per cent, solution is recommended as an application to chronic inflammations of mucous membranes. In full strength it may be applied to the gum tissue to prevent exudation of moisture, the so-called "weeping gums," during filling or setting of a crown. In the treatment of pyorrhea alveolaris this drug may be applied in from 90 per cent, down to 5 per cent, strength — the strongest solution first, as a powerful escharotic, and the strength then gradually reduced to that which is astringent and antiseptic, having the added advantage in any strength of its solvent power upon the calcareous deposits. It is also used to obtund sensitive dentine. . Acidum Lacticum. — Lactic Acid. — A colorless, syrupy liquid containing 85 to 90 per cent, of absolute lactic acid [CsHeOs]. It is obtained by lactic fermentation of milk-sugar or grape-sugar. It is strongly acid in reaction, freely miscible with water, alcohol, or ether; insoluble in chloroform. It does not coagulate albumin, but may be employed as a solvent to fibrinous exudates, as in diphtheria, a 20 per cent, solution being applied. A solution of 20 to 50 per cent, may be used in the treatment of pyorrhea alveolaris to soften remnants of calcular}^ deposit in the tooth socket. tion is not used medicinally to any extent, but it is the basis for the preparation of spirit of ammonia. It is a volatile caustic, the vapor being extremely irritating to the air passages. The United States Pharmacopoeia directs that it should be kept in strong, glass-stoppered bottles, not completely filled, in a cool place. The bottle should be opened cautiously ^vith its mouth directed away from the face; and if the temperature is warm, the bottle had better be cooled before opening, as otherwise the gas may be under considerable pressure. In case of accidental swallowing of this caustic, sjinptoms of irritation of the respiratory tract, with dyspnea, will be prominent. This will call for a volatile antidote in addition to the free dilution of the poison by water. The proper antidote will be the vapor of strong acetic acid, in the absence of which strong vinegar may be swallowed and its vapor inhaled. Stronger water of ammonia is a powerful saponifying agent. It does not coagulate albumin. The ordinary water of ammonia (10 per cent.) may be prepared from this stronger solution by diluting with twice its volume of water. Potassa and soda are the only caustic alkalies used in dental practice, and these very seldom. They are prepared in form of sticks, which deliquesce readily and must, therefore, be kept in tightly-corked bottles and must not be handled without protection of the fingers. Their affinities are for water and acids. They do not coagulate albumin, therefore their penetration is unhindered. They corrode deeply, causing severe pain. They are in no respect superior to iodine and carbolic acid as superficial caustics, and accordingly have little to recommend them at the present time. Their action is more easily controlled than that of arsenic, as they can be completely neutralized by weak acids. They may be useful in the place of arsenic for the removal of small tumors. In poisoning by one of the caustic alkalies the usual rule of giving water freely to dilute the poison applies, with the additional advantage that water satisfies one of the affinities of either soda or potassa. The chemical antidote to follow dilution is any dilute acid, giving preference to the less irritating vegetable acids, such as vinegar and lemon juice. (See Table of Poisons and Antidotes.) While only the strong alkalies are classed as escharotics, even the dilute solutions known as UNCLASSIFIED ESCHAROTICS 75 liquor potassii hydroxidi and liquor sodii hydroxidi (not less than 4.5 per cent.) are decidedly caustic and irritating to mucous membranes. As an alkali soda is slightly stronger than potassa. Both are powerful saponijQers. Phenol. — Carbolic Acid [CeHaOH]. — Hydroxybenzene obtained from coal-tar or made synthetically, being of not less than 97 per cent, strength. The average internal dose is 1 grain (0.06 gm.) well diluted. [Crude jjhenol is a liquid consisting of various constituents of coaltar, having an odor resembling that of creosote. It is used only as a general disinfectant, never internally as a medicine.] Phenol was discovered in 1834 by Runge, who gave it the name of carbolic acid. In chemical nature this substance is not an acid, but an alcohol, the term "acid" having been given to it probably on account of its corrosive action. It is only slightly acid to test-paper, and while it combines with a few bases, the resulting salts are so unstable as to be decomposed by carbonic acid. It is not capable of neutralizing alkalies. It is a definite, crystalline compound, with a distinct, sweetish odor, soluble in about 15 parts of water, very soluble in alcohol, glycerin, ether, chloroform and oils. The crystals liquefy easily in a warm temperature, and reform when the liquid is cooled; but a permanent liquid form may be secured by the addition of 5 to 10 per cent, of water or glycerin. By exposure the liquefied drug gradually acquires a pinkish and later a reddish or brownish color, which does not lessen its value. According to Demant,* the color of phenol may be removed, and perfectly white crystals again obtained, by adding 11 parts of alcohol to 89 parts of the phenol, subjecting the mixture to freezing, and then draining off the portion remaining liquid. As a caustic this drug differs from all others in having a local analgesic effect following a momentary irritation. Its most decided affinity is for albumin, which it coagulates quicliy and firmly, thus limiting penetration beyond the superficial layer of tissue, f Its analgesic effect, t Experiment. — To show the effect of phenol upon mucous membrane and the restorative effect of alcohol : Evert the lower hp and, after drying, touch two separate points each with the quantity of phenol that will adhere to the head of a pin. See the white coagulum form at each point. After half a minute dry the surface and apply a few drops of alcohol to one coagulum. Xote the difference in the two points after a few minutes. Also observe the results next day. combined uitli a superficial but decided corrosive action, makes it an ideal caustic for limited ai)plication to a mucous membrane. Extensi\'e application might, indeed, cause inflammation and symptoms of poisoning, and must be avoided. Upon the skin the action is less energetic, although still quite caustic where the skin is soft or thin. In case of accidental contact uith tissues, the effect may be mitigated by the immediate application of alcohol, as explained later in the discussion of poisoning. The drug may be applied pure to ulcerated or denuded points, whether painful or not, ^ ith the result that any septic process present will be antagonized, and the coagulum formed will protect exposed nerve endings. Thus applied to canker sores, it will relieve the pain for a considerable time and check the bacterial activity. The sore should first l>e dried and just sufficient of the pure drug applied to cover well the ulcer. Several daily applications may be needed for complete relief. Carbolic acid is not an efficient devitalizing agent, because it does not penetrate, and its superficial effect is not sufficiently irritating to induce engorgement of the deeper tissues. Only in deciduous teeth is carbolic acid made use of as a pulp devitalizer. Here a slovver effect occurs from repeated ajiplications, without the pain that may attend the use of arsenic and without any danger of systemic disturbance. For disinfecting alveolar abscess and stimulating repair, a small quantity of pure phenol upon a pledget of cotton may be introduced after the abscess has been evacuated; or, in suitable cases, it may be pumped through the apex of the root into a pus tract and through a fistulous opening. It is frequently used as a pulp dressing in case of toothache from exposure of pulp, but never \\ hen the pulp is to be conserved, on account of its destructive action upon it. It may also be applied to obtund sensitive dentine. It has been used to lessen the sensitiveness of the gums in order to apply a rubber-dam ligature far beyond the gum margin. But for this, as for nearly ever}' purpose as an analgesic, it is inferior to cocaine, and has the further disadvantage of always destroying some tissue when applied strong. The uses discussed thus far apply to the pure carbolic acid or a slight dilution of it. But the most important place of this substance in medicine is as an antiseptic, under which heading will be discussed its more general uses in diluted solutions. of poisoning combine those of local injury to the lining of the digestive tract, with shock and great depression of the nervous system, the latter often leading to death within an hour. The antidotes are albumin in the form of raw egg, or milk or flour paste as substitutes for it, and alcohol. Albumin furnishes material for the poison to act upon and expend its corrosive po^er in coagulation. It must be given early to be of use. It is a true chemical antidote. Alcohol is employed in phenol poisoning but it is not a chemical antidote. It seems to act upon the corroded tissue, lessening the destruction that would follow, its action being physiological rather than chemical. It has been found that the hands may be immersed in pure liquid carbolic acid, and, if washed immediately afterward in strong alcohol, no harm to the tissues will result. Also, if carbolic acid be applied to the mucous membrane with the production of the white, superficial coagulum, and strong alcohol be then applied, the white spot will partly disappear and the corrosive action be much diminished.* An explanation of this antidotal influence of alcohol is found in its affinity for water, which it draws toward the surface, thereby furnishing more fluid for redissolving the coagulum and diluting any uncombined carbolic acid that may be present in the tissue. (See Table of Poisons and Antidotes.) The poisonous effects of phenol are not limited to its local action upon tissue, t When it is absorbed in considerable quantity it gives rise to irritating products which may seriously damage the kidneys, liver and other organs. Fatty degeneration of various tissues has often been found postmortem. Corresponding to this action the urine in phenol poisoning often shows an olive-green or dark color. To counteract the systemic poisonous action it is advised that a soluble sulphate be given for some time, so that harmless combinations may be formed and eliminated; but the value of this treatment has been questioned, and by some authorities believed to have been disproved. t In the Philadelphia Medical Times, vol. xi, p. 284, Taylor records a case in which a man, who was supposed to have swallowed about 1 ounce of carbohc acid, became comatose within three minutes and died within four minutes from the time of taking the poison. In the New York Medical Journal, November 30, 1889, Richardson reports a case in which equal parts of carbolic acid and sweet oil, apphed to a burn on the arm of a child seven months old, caused stupor in two hours, and death occurred, with convulsions, thirty hours after the appUcation. modified action, which is at times desirable: Camphorated phenol, or campho-phenique, consists of about equal parts of camphor and phenol, which liquefy when heated together. It is less soluble than phenol, and it does not corrode tissue. Used chiefly as a disinfectant canal dressing and as an obtundent. JAquor sodii carholatis contains 50 per cent, phenol (see formula, p. 128). It is somewhat caustic if used in full strength. It provides a strongly alkaline application for limited use as a disinfectant. Chloral-phenol, prepared by triturating together with heat, 1 part chloral hydrate and 3 parts phenol. The product is an oily liquid which may be used as counterirritant and local analgesic. Iodized phenol, consisting of a mixture of iodine and phenol in varying proportions, whereby the irritant property is increased. Equal parts of tincture of iodine and phenol is sometimes used as a counterirritant. Argenti Nitras Mitigatus. — Diluted Nitil^te of Silver. — Mitigated Caustic. — IMoulded sticks consisting of 1 part silver nitrate and 2 parts potassium nitrate. (Not official.) Nitrate of silver occurs primarily in colorless crystals, having a bitter, metallic, and somewhat caustic taste. Its aqueous solutions are neutral. From the crystals are prepared the moulded and diluted forms, which are in pencils or sticks convenient for application. All forms are freely soluble in water, the pure salt being soluble in 0.4 })art and in 30 parts of alcohol. This drug in any form or strength of solution turns dark upon exposure to sunlight. This is a standing objection to its use about the face, and especially about a carious tooth, the structure of which it may stain permanently if allowed to penetrate the dentinal tubuli. A stain upon the skin remains until the stained epithelium is Avorn away. It cannot be removed sooner except by paring or scraping away the superficial layer, but the stain upon a fabric may be easily removed by a weak solution of potassium cyanide. The prolonged internal use of silver in any form may cause a permanent blueness of the skin called argyria. for some time, but the effect is quite superficial because of the coaguhim formed, which hinders penetration. It has long been used to cauterize wounds that are probably infected, such as dog bites and dissection wounds, but it must be regarded as poorly adapted to this use. It does not penetrate deeply, therefore cannot be relied upon to destroy the infected tissue, and it, moreover, by coagulating the surface, checks hemorrhage that might be useful in washing away the infectious matter, and it seals in, as it were, the point of infection. Its use, therefore, as a cauterant for deep, infected wounds must be condemned. by the coagulant reaction. The field of usefulness of this drug is for superficial effect upon invisible surfaces, where it is desired to have the irritation pronounced or productive of a secondary stimulation of the local circulation. According to the degree of action desired it may be applied in the pure stick of lunar caustic, the stick of mitigated caustic, or in aqueous solution of 1 to 10 per cent, strength, the weaker solutions being astringent rather than caustic. It is frequently applied to abort acute inflammations and as a stimulating caustic to indolent ulcers. In dental practice silver nitrate is used to check caries in temporary teeth, where fifling is impracticable. It was fir-st recommended for this purpose by S. Stebbins, in 1891. Szabo, of Budapest, has made the most extensive scientific study of this action. He found by experiments that: For the purpose stated it is applied either in pure form, or in saturated aqueous solution, at the point of decay. The fused stick may be employed, or some of the crystal may be melted upon a heated plati'num point and carried to the tooth, as recommended by Craven; or a silver wire dipped in nitric acid may be used. Holmes* advises, for approximal cavities, to carry the powdered crystal adhering to a piece of gutta-percha, which has been softened by heat, of proper size to remain in the cavity. The silver nitrate is thus retained for a long time. Because of its coagulant power it may also be used to obtund sensitive dentine in cavities that are not visible, where the staining would be less objectionable. Its distinctive antiseptic value is discussed inider Antiseptics, Incompatihility. — With alhumhums matter coagulation occurs; with hydrochloric acid, soluble chlorides, or chlorine solutions, a precipitate of chloride of silver occurs; in contact with most metals it is reduced to metallic silver; an aqueous solution acidulated with nitric acid and heated with alcohol will form the explosive "fulminating silver." In poisoning by silver nitrate the chemical antidotes are albumin and sodium chloride. The latter forms ^^'ith it the insoluble chloride of silver. In case of the use of the drug locally any excess may be at once removed by sodium chloride solution. (See Table of Poisons and Antidotes.) Hydrogen dioxide [H2O2], in very strong ethereal solution (25 per cent.), is a caustic, but its uses as such have not been very definitely developed as yet. It is used chiefly as a bleaching agent. Care must be taken in handling this strong solution to avoid its action upon the hands. Oiling will protect the skin from its action. Alumen Exsiccatum. — Dried Alum. — Burnt Alum [i\lK(S04)2]. Alum, by being deprived of its water of crystallization, is changed from an astringent to a mild caustic. It has little influence upon firmly organized tissue. It is used chiefly to destroy excessive granulations in wounds or ulcers, the so-called "proud flesh." The powder is applied directly. Cupri Sulphas. — Sulphate of Copper. — Blue Vitriol [CUSO4+5H2O]. Ks, a mild caustic the pure crystal may be api)lied to mucous membranes, the typical condition for its use being found in granular eyelids. It is acid in reaction. In strong aqueous solution it has been applied to pyorrheal pockets, but here it is an inferior agent because of the danger of discoloring the root and tooth. It is likewise astringent, and is more fully considered in that relation. (See under Astringents, also Table of Poisons and Antidotes.) Chromii Trioxidum. — Chromic Anhydride. — Chromic Acid [CrO,i]. It occurs in purplish-red crystals, which are soluble and deliquescent, forming chromic acid. Alcohol decomposes it sometimes with explosive violence. It is an energetic caustic, but rarely used. and acid in reaction. The salt is very deliquescent, therefore the drug may commonly be in either solid or liquid form. It is soluble in 0.3 part of water and very soluble in alcohol. Used pure it is a very energetic caustic. Its affinities are for water and albumin, therefore its action is prompt, producing a firm, white eschar. It is held to be the most penetrating of all coagulants. The official liquor zinci chloridi (50 per cent.) may be employed, or a stronger solution prepared, as a penetrating coagulant anient within the structure of the tooth. After removal of the pulp it will efficiently disinfect and coagulate the contents of the tubuli. Indeed, in the stronger solutions, it is used more in treating tooth structure than soft tissues, on account of the pain attending its action upon the latter. It has long been used in full strength to lessen the sensitiveness of dentine. Its action is not a simple one, but is based upon its affiaity for water, and its coagulant power, to which is added the irritant influence of a small quantity of hydrochloric acid liberated in the coagulant reaction. Care must be taken not to apply it so near the pulp as to produce irritation; and repeated applications may be needed as excavation proceeds. When irritation of the pulp is feared from its use, the cavity should be at once irrigated with tepid water. It is one of the agents used to cauterize and stimulate the closure of alveolar pockets about the roots of teeth in cases of recession or pyorrhea. In" addition to its other dental uses, it is very effective in the treatment of chronic aiveolar abscess. It should be applied directly to the abscess cavity thrbugh the root canal or through an external opening. It is very painful for a short time when first applied. In addition to its escharotic action it produces considerable irritation, thereby setting up an active inflammatory process which hastens resolution. For this purpose it may be used in a solution varying in strength from 10 to 50 per cent. It must be ranked as a corrosive poison. The preparations likely to cause poisoning are the full strength liquid, the 50 per cent, solution, and the popular "Burnett's disinfecting fluid," which contains 200 grains to the fluidounce (about 42 per cent.)- The chemical antidotes are albumin and dilute solution of sodium or j)otassium carbonate. (See Table of Poisons and Antidotes.) Following the U. S. P. description, arsenic is a heavy solid, occurring " either as an opaque white powder, or in irregular masses of two varieties: one amorphous, transparent and colorless, like glass; the other crystalline, opaque and white, resembling porcelain. Contact with moist air gradually changes the glassy into the white, opaque variety. Both are odorless and tasteless."* "In cold water both varieties dissolve very slowly, the glassy variety requiring about 30, the porcelain-like about 100 parts of water at 25° C. (77° F.). Both are slowly but completely soluble in 15 parts of boiling water. In alcohol, arsenic trioxide is sparingly soluble, but it is soluble in about 5 parts of glycerin." An aqueous solution is only faintly acid in reaction. Wherever the term "arsenic" is used in the following pages it stands for the official arsenic trioxide. The characteristic action of the drug is due to the ion of arsenous acid and not to the element arsenic, which is insoluble in water. Arsenic stands alone in its characteristics as an escharotic. The dry powder may be placed on the tongue and allowed to remain for one minute without causing the slightest irritation and, if then thoroughly removed, without producing any effect upon the tissues. On the contrary, if it is allowed to remain until it becomes dissolved and penetrates the tissues, extensive sloughing will result. It cannot be called an irritant. It is not a corrosive. It has no decided chemical affinities; therefore, it is not escharotic b}^ reason of any apparent chemical action. It stands by itself as a vital or alterative eschar otic, in that it acts only after being absorbed by the tissue elements, altering or destroying their vital processes in an obscure manner. Because of this action it is difficult, if not impossible, to limit or antagonize its influence upon the tissues which it has penetrated; and its penetration is not lunited by any action of its own. The fact of its being tasteless and non-irritating at first, renders its use about the mouth the more dangerous, for by careless handling it may become lodged about the teeth or beneath the edges of the gum,' and its presence be not appreciated for hours, until devitalization of the tissue has begun. It does not coagulate albumin. The drug acts slowly, penetrates deeply, and destroys tissue extensively. It seems to affect abnormal or unorganized tissue elements, as in cancer, more readily than normal tissue; hence its use in the removal of abnormal growths. As an escharotic it is always used in its pure form, although often mixed with other agents for convenience of application or to mitigate its action. The medicinal solutions officially prepared from it are all for internal use, to secure the general tonic and alterative effects of the drug. Therfore, when we speak of applying arsenic locally we mean always arsenic trioxide in powder form or in mixture. (See Alteratives.) Dental Use. — It is rare that arsenic is used in the mouth for any other purpose than devitalizing pulps of teeth; and it may be ^aid today, after more than half a century of experience with it and with other less dangerous but less efficient devitalizants, that it is the substance of first choice for this purpose. It is only with deciduous teeth that a less powerful agent must be chosen. Here the danger would be penetration of the arsenic through and beyond the apex of the root, with a corresponding extension of its destructive action. With the exception noted, it is true generally that nothing need be feared, in the way of extension of its action, when the drug is carefully used upon the tooth pulp. The natural confines of the pulp cavity and root canal prevent its penetration to other tissues, so that only careless handling and inappropriate or excessive use need be followed by bad results. While we must admit the possibility of irritation extending beyond the pulp chamber in case of a good-sized apical foramen, a septic inflammation could not be expected from the action of the arsenic, itself being a strong antiseptic. With the small amount necessary to destroy a pulp, systemic effects will never occur. The ordinary medicinal dose of arsenic is from ^q to tV of a grain, which need never be exceeded for this use; according to jMiller from y'Wo to 2^5 is sufficient. It should be impressed upon the mind of the practitioner that any untoward effects that may follow his emplo^inent of arsenic in a tooth \\ ill be purely local and the result of either ^ant of care in its application or lack of judgment as to its appropriateness . The precise mode of action of this drug as an escharotic cannot be stated ^^"ith positiveness. The several views advanced merit our attention, but discussion of them to a definite conclusion is hardly possible. Sollmann* regards paralysis of the capillaries as the beginning of its action, ^^■hich, with increased permeability of their walls, is followed by exudation into the connective tissue. These changes, it is observed, are very similar to those of inflammation. Fatty degeneration of cells results and the destruction of tissue is accomplished without evident chemical reactions. This author finds support to the theory of capillary paralysis in the fact that intravenous hijections of large quantities of salt solution will cause edema in animals poisoned with arsenic, but not in normal. He suggests further that the distention of capillaries may lead to their rupture and the formation of ecchymoses. (It would seem that such changes must take place in the walls of the digestive tract in arsenical poisoning, for the symptoms and the appearance of the discharges are almost identical with those of cholera, and the destruction of tissue found after death is regarded as due to degeneration and not to any direct action of the poison.) Regarding changes in the blood opinions differ, but Silberman* asserts that arsenic tends to cause intravascular coagulation, and the experiments of Heinz t indicate that this is not ordinary coagulation, but formation of thrombi of blood plates, and he attributes the hemorrhages to such thrombosis. A theory of the action of arsenic advanced by Binz and Schultzi is to the effect that arsenous a( id is oxidized to arsenic acid by living tissue and the arsenic acid is again reduced to arsenous. This alternate withdrawal and supply of oxygen, in its influence upon the protoplasm, is supposed by them to be the essential feature of the action of arsenic. Arsenic will attack any soft tissue to which it is applied, so that, when explaining its action, we must recognize its influence upon the vitality of tissue apart from kind or location; but within the pulp cavity and upon so vascular and highly sensitive an organ, enclosed as it is by bony walls with very small unyielding openings for vessels and nerves, the factors of increased pressure, due to the intense hj'peremia, and leading to stoppage of the circulation by strangulation of vessels or by thrombosis, is believed to contribute largely to the destructive action. The occurrence of pain in connection with pulp devitalization depends somewhat upon the condition of the pulp. A healthy pulp, that has not become irritated, may be destroyed without any pain; but in the average case where irritation has occurred, it must be expected that within a varying period of time after the application, usually several hours, the patient will experience pain, first gnawing, later throbbing in character, which will continue until the pulp is destro}'ed, which is accomplished in from six to forty-eight hours, as a rule. Combinations. — In its use as a devitalizer, arsenic is combined with other substances to meet two objects — to obtain a convenient form for application and to lessen the pain of its action. The form mostly preferred is that of a paste, which is prepared by rubbing up the powdered arsenic with a sufficient quantity of a volatile oil, creosote, glycerin or carbolic acid. The antiseptic character of these drugs may be held by some to give added value, but arsenic itself is a sufficient antiseptic as to really need no addition on that score. § It should be noted that any t Ibid. t Ibid., p. 619. § According to Koch's experiments (Brunton's Pharmacology', 1885, p. 98), arsenic is one-tenth as strong as bichloride of mercury in antiseptic power. Cushny (Pharmacology, third edition, p. 619) states that it is less poisonous to fungi than to higher forms of life, and that it seems to have no effect upon the action of pepsin and similar ferments. strong coagulant, such as carbolic acid, by coagulating the surface of the pulp where the application is made, -vvill tend to hinder penetration of the arsenic, on which account it is inferior to a volatile oil. Sometunes cotton fiber is incorporated with the paste, and being then dried, is known as "devitalizing fiber."* To lessen the pain of de^'italization a number of drugs have been recommended and used, but the list can now be narrowed down practically to one, or substitutes for it. Cocaine hydrochloride possesses every quality that is essential, with no serious disadvantage. It is soluble, it mixes with the substances usually combined in the paste, and it is more efficient than any other known agent. The danger of absorption into the general circulation, with the small quantity employed and the barrier presented to its penetration, is so slight that it may usually be disregarded. Any quantity not exceeding one-quarter of a grain may be regarded as safe to use. Proper substitutes for this drug are eucaine, novocaine and orthoform, any one of which may be employed, but they are not more efficient than cocaine. Their chief advantage is in being less toxic, although it may be found by experience with orthoform that its influence is more prolonged because of its insolubility. In considering this part of the subject it should be remembered that pain in a tooth pulp can be practically relieved at two points — either at the pulp, by agent;^ that paralyze the terminals of the sensory nerve, or at the centers of appreciation of painful sensation in the brain, by agents that depress or benumb those centers. Corresponding in their site of action to these two points, we have two classes of anodynes — those that act locally upon the periphery of nerves, and those that act centrally upon the centers for painful sensation. Agents that act locally as anodjaies have little or no central effect in ordinary doses^ and, conversely, agents that relieve pain by depressing brain centers may have no effect of this kind when applied locally. This line of discussion is prompted by the fact that morphine is so commonly recommended as a local anodyne combined with arsenic. This is entirely opposed to our knowledge of the action of morphine. This drug has almost no local action when applied to sensory nerve endings, but is anodyne only through its central action, after being absorbed into the blood in sufficient quantity. Morphine locally applied, therefore, can be of little use for the purpose of mitigating the pain or irritation caused by arsenic. This fact was recognized many years ago* and is fully supported by the most recent authorities.! The volatile oils, thymol, iodoform and carbolic acid are all feebly analgesic, but inferior to cocaine, while iodoform has the disadvantage of disagreeable odor, and carbolic acid is a coagulant. Local Poisoning by Arsenic. — The lodgment of arsenic between the teeth or beneath the edge of the gum will cause, after some hours, local irritation leading to engorgement of the gum, which will be followed by sloughing if the poisoning is severe. Pain may be absent. These symptoms will correspond in extent to the depth of penetration of the arsenic, sometimes including pericementum and alveolus. All tissues whose vitality has been seriously disturbed must be expected to slough away. Treatment of this condition will include the removal, by cutting or scraping, of all tissue that has been destroyed, the scarification of engorged tissue to secure free bleeding, and washing away of any particles of the drug that may remain undissolved, by injecting a stream of water between tooth and gum. Following this, gentle massage of the gums of the whole region will be useful. As a rule, when the patient * Harris's Principles and Practice of Dentistry, tenth edition, 1876, page 371. "Morphine was formerly supposed to modify the irritating action of arsenous acid, but since this has been discovered not to be the case, its use has been dispensed with by many." t Cushny, Pharmacology and Therapeutics, 1901, page 208. "It is often stated that the sensory terminations are paralyzed by morphine, and solutions are therefore injected into the seat of pain, or hniments are rubbed into the skin over it, but as a matter of fact, morphine seems entirely devoid of any such local action." SoUmann, Pharmacology, 1901, page 204. "Particular stress must be laid on the fact that the sensory endings are in no way affected, so that the local application of morphine or opium is entirely iiTational." presents with these s\7nptoms the damage will have been done, and local medication is of doubtful value. But if any arsenic still remains about the tissues, the freshly prepared ferric hydroxide will neutralize it wherever accessible. The latter may be packed about the teeth and beneath the gum margin. Dialyzed iron has been recommended, but it is inferior to fresh ferric hydroxide (see below). Tincture of iodine is beheved by some to be a useful application, and the same may be said of tincture of chloride of iron, but neither of these exert any antidotal action except as they stimulate the tissues to better resistance. Scarification will usually precede the use of any of these agents. General Poisoning by Arsenic* — Acute general poisoning occurs as the result of an overdose being taken into the stomach. Usually the symptoms develop slowly, beginning with gastrointestinal irritation. There is in most cases sufficient tune to administer an antidote and empty the stomach if the mistake of dosage is discovered at once. An ordinary emetic is to be given at once (one to three teaspoonfuls of mustard flour in a glass of lukewarm or cold water, or the same quantity of either powdered alimi or common salt with a little water, or one-third of a teaspoonful of sulphate of zinc); meantime the antidote should be prepared and given. The best antidote to arsenic is ferric hydroxide, which is prepared by adding an alkali to a solution of a ferric salt, which precipitates the brown ferric hydroxide. It must be freshly prepared. This is easily done by mixing 7)iilk of magnesia (Magma Magnesiae, U.S. P.) with tincture of chloride of iron or with MonseVs solution, both agents to be diluted somewhat before mixing. It should be taken freely immediately after being mixed, as it gelatinizes upon standing. The official dose is f§4 (120 mils). (See also Table of Poisons and Antidotes.) Cobalt (not official). — While pure cobalt [Co] is a distinct chemical element, in the commercial form arsenic is associated with it. It is employed to devitalize pulps, and in this use it acts very much like diluted arsenic, being slower in action and less irritating than pure arsenic, and, in some cases, even painless. * The fact may be stated that in some parts of the world, especially in Styria, the peasants take arsenic habitually and acquire a tolerance to the drug, so that they take quantities which would ordinarily be poisonous. It is claimed that it secures a ruddy complexion and plumpness of form, as its action favors the deposit of fat in the tissues, and that mountain climbing is easier under its use, requiring less effort and producing less respiratory discomfort. Actual Cautery. — This term applies to the use of heat of sufficient degree to burn the tissue. Formerly an iron or silver wire was employed, heated to a white heat. Pulps were destroyed by plunging the heated wire directly into the pulp canal. Fortimately both the means and its use have become obsolete. Nevertheless heated metallic points and wire loops are frequently employed in general and special surgery today. The approved methods of applying the actual cautery are the following : Thermocautery. — Under this term there is arranged an apparatus, by means of w^hich a platinum point, previously heated up in a gas or spirit flame, is maintained continuously at a white or red heat by the combustion of gasoline vapor forced through it. Paquelin's thermocautery is the one mostly used. Platiniun points of various sizes and shapes permit an extensive use of this method for removal of small tumors, checking hemorrhage, etc. It is seldom used about the mouth, preference being given to the galvanocautery. Galvanocautery. — This consists of a galvanic battery, arranged in simple circuit — i. e., with all positive elements connected together and likewise all negative, so as to equal in effect one large cell. A battery so arranged presents a large surface of elements with the resistance of only one cell. It furnishes a large quantity of electricity capable of producing a high degree of heat when it meets with external resistance. Platinum loops in various shapes and sizes, adapted to cutting, searing or snaring tissue, are employed. One of these mounted upon a suitable hand-piece and included in the current furnishes a sufficient resistance to convert the electricity into heat, the degree of which can be easily regulated by mauipulation of the battery. A great advantage attaching to this method, for use about the face and mouth, is that the patient need not see the heated loop. It may be placed right in proximity to the diseased or bleeding tissue before the current is turned on; and if the application of cocaine precedes its use the pain is not severe. DEMULCENTS. Demulcents are agents that protect or soothe raw, irritated or inflamed surfaces. They consist chiefly of oily, mucilaginous or albuminous substances, of which the ones here named are the most important: The oils are used in their ordinary form, as a rule; sometimes, however, the addition of an alkali is ad\isable, and such a combination is found in the time-honored 'carron oil," known officially as linimentirai calcis.* This has long been a favorite application to burns and scalds. A disadvantage in its use lies in the fact that linseed oil dries upon exposure, and the stiffening of the dressing which results may make it more difficult to remove. This may be obviated by substituting cottonseed oil for linseed oil in the combination. In poisoning by corrosives and irritants, demulcents are valuable to protect the injured surfaces. Any of the above are applicable, except that in poisoning by phosphorus or cantharides oils shoukl not be used, as they are solvents for these drugs. In any case where albumin is the proper antidote it may be the demulcent of choice so as to serve a double purpose, raw egg being the best form. The mucilaginous drugs are employed in aqueous solution, either infusion, mucilage or syrup, and are for internal use, being seldom applied externally except in poultices. When flaxseed tea is to be prepared, the whole seed, not ground, should be treated with hot water. The mucilage is present in the shell and is thus easily dissolved out. The ground seed is used only in poultices. EMOLLIENTS 91 Certain sialagogues and expectorants may exert a secondary demulcent effect through stimulating secretion in the irritated or inflamed part. Irritation of the air passages, and particularly an irritative cough, is often due to dryness of the mucous membrane. Sialagogues or expectorants may be the very best agents to relieve this irritation by increasing secretion, which moistens the irritated surface, and at the same time the engorgement of the tissue is lessened. The drugs mostly used in this way are: Emollients are agents that soften and soothe an inflamed part. Fatty preparations, in the form of ointments, are used to soften the skin and at the same time protect denuded or ulcerated surfaces from dust and from the drying effect of the air. Its penetrating and softening power, it is claimed, exceeds that possessed by any other fat; and it has the unique property of mixing with at least 30 per cent, of its own weight of water without losing its ointment-like character. The latter quahty permits the use of solutions of salts or alkaloids in an ointment, which is often desirable, as in case of a painful sore. Here a crj'stalline substance like cocaine should be more active when in solution and mixed with lanolin, than when the particles are simply rubbed up with a fat that has feeble penetrating power. Where protection by a fat is the chief purpose, lard (adeps) and vaseline (petrolatimi) are the most commonly employed bases for ointments, but in softening and penetrating power they seem to be inferior to lanolin. Lard, being an animal fat, is better in this respect than vaseline, which is not a true fat, but a product obtained in the distillation of petroleum. The poultice (cataplasm) is another form of emollient application. Various substances may enter into the composition of poultices, but the possibilities of their use are most typically combined in ground flaxseed. The shell of this seed contains 15 per cent, of mucilage and the interior contains 25 to 40 per cent, of oil. By treating the ground seeds with hot water we obtain a poultice having the emollient qualities of both oil and mucilage. Applied hot the relaxing effect of the heat contributes to the softening process, and altogether we have in the poultice a great aid in either resolving an inflammation, or hastening suppuration when it cannot be prevented. 92 DEMULCENTS AND EMOLLIENTS Glycerinum. — Glycerin. — Glycerol. This substance is obtained by decomposition of oils and fats, being a by-product in the manufacture of soaps, and it should contain not less than 95 per cent, of absolute glycerol [C3H5(OH)3], a trihydric alcohol. It is a thick, heavy, colorless liquid, neutral, freely soluble in water, in alcohol and in a mixture of 1 part ether and 3 parts alcohol, but insoluble in ether, chloroform and oils. Its specific gravity is about 1.250. It has a sweet taste, and when applied to a mucous surface produces a warm or burning sensation. It does not coagulate albumin. The chief quality that determines its action upon tissue is its marked affinity for water, it being capable of absorbing 50 per cent, of its own weight; therefore, when applied to a raw surface glycerin may irritate by its energetic abstraction of water, but it does not irritate the unbroken skin or mucous membrane. Its eftect upon tissue is to soften and protect. As an emollient, glycerin is used extensively in hand lotions and either in full strength or diluted with an equal quantity of water, as a simple application to chapped hands. Here its action is typically seen. The smarting at first experienced is due to its abstraction of water from the tissues wherever the skin is cracked or broken. This is succeeded by a softness of the skin, due to the increased amount of moisture which is attracted into the superficial layers of epithelium by the action of the glycerin. When we observe that chapping of the hands occurs mostly in cold weather, when the absolute moisture of the atmosphere is greatly reduced by precipitation, we can appreciate the importance, as a causative factor, of excessive drying of the skin by the surrounding air; and we are helped to an understanding of the value of glycerin as a retainer of moisture wherever applied to soft tissues. The maintenance of a normal degree of moisture is, of com-se, essential to the healing of wounds of the skin. Roughness of the hands, or of the skin of other parts, is effectually treated by a lotion of glycerin and water, or glycerin, water and alcohol. If there is a tendency to scaling of the epithelium, or increase of sebaceous secretion, as in "dandruff" of the scalp, the addition of salicylic acid is very useful. The following formula is suggested: Glycerin keeps indefinitely and is even classed among the antiseptics. It is an excellent preservative. It is used also as a solvent and vehicle for other drugs, and is often incorporated in small amount with extracts in order to keep them from becoming dry. Its combination with tannic acid, known as glycerite of tannic acid,* is a powerful astringent. In dentistry it is used in case of hyperemia of the pulp previous to capping; also after the application of arsenic to a pulp, it may be employed to harden or tan the pulp tissue in order to facilitate its removal. It is a generally useful astringent to mucous membranes. Incompatibility. — With borax a solution is formed which becomes acid in reaction, but whose value is not otherwise lessened. Glycerin should never be combined with nitric and sulphuric acids, nor with chromic acid, chlorinated lime or potassium permanganate, for fear of explosive results. ASTRINGENTS AND HEMOSTATICS. Astringents are agents that cause contraction of tissue. In a general view of the use of ajStringents, we include the checking of hemorrhage and of diarrhea and the lessening of inflammation, particularly of the mucous surfaces. 4. Abstraction of water from the tissues, as by alcohol locally applied. The terms hemostatic and styptic apply to agents that arrest hemorrhage. Most of these act by securing coagulation of the blood, but some act mechanically, such as ligatures and bandages, and others lessen the blood supply to the bleeding part, as cold and arterial sedatives. Other styptics induce contraction of the arterioles; ergot, antipyrine, suprarenal gland and the local application of hot water, all act in this way, ergot acting through the system, while the others act by local application. Collodion exerts pressure through contraction of its volume while drying. It must be borne in mind that the one object of employing any hemostatic is to secure coagulation of blood at the point of hemorrhage; and the employment of the various agents can only facilitate this process; so that the use of coagulating agents, the lessening of the amount of blood in the part, the contraction of arterioles, and the employment of pressure, all have precisely the same object, but secure it in different ways. The choice of agent depends upon locality and size of the vessels that are injured. A capillary hemorrhage can usually be controlled by coagulants, or by cold, or by agents like antipyrine, which causes the arterioles to contract. If the hemorrhage is from a larger vessel, or from a tooth socket, where the muscular control of the capillary circulation is dt^ficient, pressure upon the bleeding points, or, in extreme cases, ligation of the vessel, may be required. Again, in case of hemorrhage from the bowel or lung, perfect rest of body and mind, the ice-water coil and arterial sedatives will be employed. But with all our art we are only aiding nature to secure coagulation. Application of Cold. — By this is meant not only the abstraction of heat, which may be desirable, but also the contact of a substance having a low temperature with the skin, in order to cause a reflex contraction of the muscularis of the skin and of the arterioles. The ice-bag, ice- water, or ice directly applied, are the usual means. If considerablf surface is to be treated, a very convenient method of applying ice-water continuously is by means of the Leiter coil, which consists of soft-rubber tubing coiled concentrically to fit upon the part (as in form of skullcap for the head), or wound about an affected joint; through the tubing ice-water is run by siphonage as constantly as may be desired. Cold applications will be found useful to lessen the hyperemia of acute inflammation and to lessen the amount of blood in the locality of a hemorrhage. The twofold action induced is reduction of blood supply and condensation of tissue. In employing cold locally to relieve toothache we secure its astringent action upon the local circulation, and we also have the sedative effect of the cold upon the nerve endings. A pulpitis may sometimes be relieved by the contact of ice with the tooth and contiguous tissues. Application of Heat. — Practically the only uses of heat as a hemostatic are two — (1) as hot water applied to a surface where there is oozing from small vessels, the heat causing vascular constriction through irritation; and (2) as some form of actual cautery, by which the bleeding point is seared. group, therefore a discussion of its action and uses will suffice for all. Acidum Tannicum. — Tannic Acid. — Tannin [HC14H9O9]. — An organic acid obtained usually from nutgall. Average dose gr. 8 (0.5 gm.). It is a yellowish powder, becoming darker upon exposure; soluble in less than 1 part of either water or alcohol, and in about 1 part glycerin with the aid of moderate heat. These solutions have an acid reaction. Its chief action is that of a coagulant. It has a bitterish and astringent taste, but is non-irritating to the tissues. It is useful only when applied locally to tissues, as it has no effect through the circulation; in fact, tannic acid is never absorbed into the circulation. When taken into the stomach it unites with any albuminous matter present, it interferes with the activity of pepsin, and, if in excess, some may be converted into gallic acid, which can be taken up into the system. COAGULANT ASTRINGENTS 97 The drug may be applied in powder to a bleeding-point, or packed with cotton into a tooth socket. In any strength of solution it may be applied to inflamed, raw or ulcerated mucous surfaces, or used as a gargle. In catarrhal and relaxed states of the mucous membrane it is a useful application, especially when combined with glycerin. Being incompatible with alkaloids, it is used as a chemical antidote to them. In hemorrhage from the stomach it is taken in strong solution or powder form, but for internal hemorrhages outside of the digestive tract it is of no value, except as it is changed into gallic acid, which may be absorbed and possibly exert some general influence. Tannic Acid Group or Vegetable Astringents. — All vegetable astringents owe their activity to the tannic acid which they contain, so it is a matter of personal choice whether the pure acid or a drug containing it be used. For hemostatic purposes preparations of astringent drugs are rather weak, but for a mouth wash or gargle they are useful. Galla. — XuTGALL. — ^An excrescence occurring on certain species of oak, caused by the puncture and deposit of ova of an insect This is the source of the official tannic acid. Average dose gr. 8 (0.5 gm.), but the drug is seldom used except externally in the form of tincture or ointment. Krameria. This drug has a number of preparations. Hematoxylon. — Logwood (not official). — The heart-wood of Hcematoxylon campechianum. Besides tannin, this drug contains hematoxylin, which is used to stain microscopic specimens. The extract may be used. Hamamelis virginiana collected in autumn. The fluidextract is used. Tea and Coffee. — Although not official, tea leaves and coffee seeds contain a variable amount of tannic acid, tea yielding about 15 per cent, and coffee somewhat less. Drugs of this group are non-poisonous. Their preparations may be used freely as astringents either in full strength or diluted with water. [^ Alcohol. — Rectified Spirit. — Ethyl AIcoJwl [C2H6OH]. A liquid composed of about 95 per cent, by volume (92.3 per cent, by weight) of ethyl alcohol and about 5 per cent, by volume (7.7 per cent, by weight) of water. Sp. gr. about 0.816 at 60° F. It is obtained by fermentation of grain or the juices of fruits, and subsequent distillation. It is a clear, colorless, volatile liquidji, with a burning taste and a distinctive odor. Alcohol boils at 172.4° F. This agent is nentraJ. It has a great affinity foi* water, even absorbing it from the atmosphere, and it coagitlofes albumin. It burns with a blue, smokeless flame, yielding a high degree of heat, which renders it very useful in the spirit lamp. In addition it is extensively used as solvent, preservative and drying agent. The following strengths of alcohol also are official, but whisky and brandy (about 50 per cent.) and wines (8 to 20 per cent.) have been dismissed from the Phormacojjoeia. Alcohol Dehydratum (not less than 99 per cent, by weight) is the purest spirit obtainable. Owing to the strong affinity which alcohol has for water, it is impossible to separate them absolutely; but, by treating strong alcohol with potassium carbonate and fused calcium chloride, w^hich have a stronger affinity for water, and redistilling, all except a fraction of 1 per cent, of water can be remo^'ed. Absolute alcohol is equally difficult to keep in full strength on account of absorption of moisture from the air. It must be kept in well-stoppered bottles and exposure to air avoided. It is highly inflammable. It is seldom that so strong a spirit is needed, but it may be required for special uses as a sohent and as a chemical. Alcohol Dilutum (about 49 per cent, by volume). This, composed approximately of equal parts of alcohol and water, corresponds nearly to "proof spirit" (50 per cent.), which is the United States standard for measuring unrectified spirit. Spiritus Frumenti (whisky) contains from 44 to 55 per cent, b}' volume of alcohol. It is distilled from fermented grain and should be at least four years old. (Not official.) Spiritus Vini Gallici (brandy) contains from 46 to 55 per cent, by volume of alcohol. It is distilled from the fermented juice of grapes and should be at least four years old. (Not official.) Whisky and brandy do not gain in alcoholic strength by age, but they develop flavor; and, in whisky particularly, the fusel oil, which is a natural impurity of raw spirit, is destroyed during the ripening process. Local Action and Uses of Alcohol. — ^This drug is astringent by virtue of its power to coagulate albumin and to abstract water from the tissues. The coagulum is not so firm as that produced by most mineral astringents, and it may be gradually redissolved by the alkaline fluids of the tissues. When applied in the full strength to the mucous membrane, alcohol induces first a burning sensation, which becomes painful as the fuH action upon the tissue is attained. With its evaporation a cooling sensation may then be experienced. The irritation soon passes away, and there remains a sense of fulness in the part, with corrugation of the surface, which at the same time has acquired a whitish appearance in the superficial layer. GraduaUy the mucous membrane will be restored to its normal condition with very slight surface exfoliation. The action is very superficial and of only moderate duration. Alcohol, therefore, cannot rank as more than a mild astringent, but the possession of the power to abstract water, with its volatility, makes it a valuable drying agent wherever applied. Added its antiseptic quality, we have in alcohol an agent that is cooling to an inflamed surface, slightly astringent and antiseptic — the very qualities that make it (whether used pure, diluted, or as a vehicle for other substances) a very useful wash or application in stomatitis or any unhealthy state of the gum or mucous membrane. The strength as a mouth wash should not exceed 1 part alcohol to 2 parts water. It is also useful as a drying agent in cavities and root canals; and if its application be followed by that of chloroform or ether a mos perfect and rapid removal of moisture will be effected; the alcohol first taking up the moisture, evaporation is then hastened by the alcohol being taken up by the more rapidly volatile chloroform or ether. The only precaution necessary regarding this use is the avoidance of the proximity of a flame, because of the inflammability of alcohol and of ether. Alcohol is also a useful lotion when applied, somewhat diluted, to a bruised or inflamed surface; and if capillary oozing be present, its action will faA'or coagulation of blood and contraction of arterioles. It must be said that alcohol contributes much to the local action of certain tinctures, of which tinctm-e of myrrh is an example; indeed, in this preparation the alcohol is much more important and active than is the myrrh. (See under Antiseptics.) Applied to the skin, the action of alcohol is less marked than upon mucous membranes, because of the firmer texture of the former and the better protection it affords to the sensitive structures beneath. Rubbing or bathing the skin with alcohol produces, first, cooling of the surface, Avhich is soon followed by a reaction that is delightful. The power of attracting moisture gives alcohol a place as a remedy in carbolic acid poisoning. Its action here is more upon the injured tissue than upon the poison. (See Phenol Poisoning.) The same property, plus antiseptic power, makes alcohol a detergent of some value. In addition to remedial uses, alcohol is employed largely as a solvent for drugs, being the chief menstruinn in fluidextracts, thictures, spirits and elixirs, besides being used to extract many vegetable active principles. When selecting an astringent drug for use, it follows that the thwture of that dk-ug (if its solution in alcohol is possible) will be especially efficient by reason of the added action of alcohol. The internal action of alcohol is considered under Stimulants. Iruvmimtibility. — Alcohol is incompatible with albuminous substances, all of which are coagulated by strong alcohol. It precipitates gums from their aqueous solutions. On account of their insolubility in alcohol many salts of the alkalies and metals ma}' be precipitated by it from their aqueous solutions. Both chromic acid and potassium permanganate are decomposed by alcohol. Methyl Alcohol (not official). — Wood Spirit [CH4O]. A thin colorless liquid obtained in the destructive distillation of wood. It has a peculiar odor and burning taste, sp. gr. about 0.800, and boils at about 151° F. It burns with a pale, smokeless flame, giving less heat than ethyl alcohol. By partial oxidation it yields formaldehyde gas. A purified product is called Columbian Spirit. Wood spirit is used as a substitute for ethyl alcohol as solvent and for external uses. Its use as a solvent may be proper, but on account of its poisonous action it should never be used in medicine. Aside from deaths caused by methyl alcohol, many cases ha\'e been rej)orted within recent years where blindness, more or less ])ermanent, followed contact with the fumes of this drug. compounds of acids with metallic bases, so that, by their dissociation in contact with tissues, we have two distinct agents concerned in the action of each mineral astringent. This fact is given prominence by some of the later authorities in pharmacology* and its recognition removes much of the difficulty in understanding the action of these salts upon living tissues. The essentials of their action may be stated as follows: Mineral astringents have the property of precipitating albuminous or proteid substances. ■ This must be understood to be a definite chemical reaction, whereby a metallic albuminate is formed and the acid of the salt is liberated. There is, therefore, added to the coagulation or precipitation process the action of whatever acid is liberated. As they differ in coagulant power, the sum of the action of such astringent will depend, as Cushny states,! upon "Two factors — the character of the precipitate and activity of the acid formed. The latter again varying with the extent to wdiich it is dissociated into ions; it, therefore, exercises the same astringent or corrosive efi'ects as if it had been applied uncombined. But its action may be modified by the presence of metallic albuminate protecting the surface." The firmer the coagulum the less will the liberated acid irritate the tissues, and, on the other hand, the stronger the acid liberated the greater will be the possibility of irritation by it. We would, therefore, expect the mineral acid salts to be more irritating than organic acid salts. This we find to be the case in comparing the action of chloride of zinc with that of acetate of lead. Again, among the mineral acid salts those that are most easily dissociated, such as the soluble chlorides and nitrates, are found to be most irritating. A comparison of the chloride and sulphate of zinc gives evidence of this, the chloride being much more irritating. The variety of these mineral compounds permits of the selection of an agent for any grade of action desired. following, all of which are acid in reaction: Ferri Chloridum. — Ferric Chloride [FeCls + 6H2O]. An orangeyellow, crystalline salt, with a strongly astringent taste. Very deliquescent in moist air and freely soluble in water and in alcohol. It contains not less than 20 per cent, of iron. Used chiefly in the two following preparations: Tinctura Ferri. Chloridi.— Tincture of Ferric Chloride. — This contains about 5 per cent, of metallic iron. Average dose, TTL 8 (0.5 mil.). It has a very astringent taste and acid reaction. Liquor Ferri Chloridi. — Solution of Ferric Chloride. — This contains about 10 per cent, of metallic iron. Average dose,Tn, 1§ (0.1 mil.). It has a very astringent taste and acid reaction. This preparation is often improperly called persulphate of iron. The true persulphate is a normal salt, official in form of its solution {Liquor Ferri TersuJphatis) but very seldom used. Of all of the above, the liquor ferri subsulphatis or Monsel's solution is used more than all others as a hemostatic. It is objectionable on account of the copious, dirty, black coagulum which it produces; and it also stains any fabric that it touches. It is not an agent of first choice, but is used rather as a later resort when the milder astringents have failed. It is very efficient even when largely diluted. As astringents for use in the mouth, the whole group here named are objectionable because of their strongly acid reaction, which renders them deleterious to the teeth. If employed at all, strict precaution should be taken to prevent their contact with the teeth, and neutralization of their acidity should follow their use. A solution of sodium bicarbonate is a useful alkali for the latter purpose. Hemostatic cotton is prepared by satiu'ating absorbent cotton with either Monsel's solution or solution of ferric chloride and drying. It should be remembered that not all iron preparations affect the teeth. They all may form iron sulphide in a foul mouth or in a carious cavity, with a resulting stain, but only those that have an acid reaction are destructive to the tooth structure. All astringent iron salts are acid, but for internal administration there are a number of neutral preparations that are harmless. (See under Restorative Tonics.) Incompatibility. — Ferric salts in solution, with alkalies or alkaline carbonates in excess, produce a brown precipitate of ferric hydrate. With tannic acid, tannate of iron (black ink) is formed. Verroas salts with oxidizing agents are con\'erted into ferric salts. With alkalies and alkaline carbonates, solutions of ferrous salts yield precipitates. Tannic acid produces no change in ferrous salts in the absence of oxygen. Alumen. — ^Alum. — Aluminium and Potassium Sulphate [A1K(S04)2 + I2H2O], or Alumirmim and Ammonium Sulphate [A1NH4(S04)2 + I2H2O]. Either potassium alum or ammoniiun alum is official under this title. It occurs ixL colorless crystals having a s\veetish and strongly astringent taste and acid reaction. Potassium alum is soluble in 7.2 parts of cold water, 0.3 part of boiling water, freely soluble in glycerin, but insoluble in alcohol. Ammonia alum is somewhat less soluble in water. Alum coagulates albumin, acting superficially as an astringent and hemostatic. Average dose, gr. 8 (0.5 gm.). In larger dose the drug is emetic. To check slight hemorrhages the pure crystal or strong solution may be applied. For nosebleed a nasal irrigation or injection of the solution as hot as can be borne is useful. The aqueous solution may be used in any strength as a gargle or wash, but, being acid in reaction, it is not admissible as a mouth wash for continuous use. AYhen alum is subjected to a high degree of heat it loses its water of crystallization and becomes opaque and amorphous. It is then known as dried alum (aliunen exsiccatumj or ''biunt" alum, and is more energetic in its action upon tissue, being even escharotic to loosely organized tissue. Incompatihility. — Alumen is incompatible with alkalies and their carbonates. With metals soluble m dilute sulphuric acid the aqueous solution of alum will liberate hydi'ogen. Argenti Nitras. — Xitrate of Silat^r [AgXOs]. AA-erage dose, gr. \| (0.01 gm.). This drug is described and discussed qtiite fully in the chapter upon Escharotics. As an astringent it is used upon mucous membranes in conditions of relaxation or of clironic catarrh, such as chronic pharyngitis, where the dilated capillaries give evidence of a decided loss of tone in the mucous membrane. The indications here are for a drug that will cause condensation of the relaxed tissue ^dth contraction of the dilated vessels. Xitrate of silver is one of our best agents to accomplish this when applied in solution of from 1 to 5 per cent., the stronger solutions being commonly used with an atomizer. It is irritatmg, but superficial m its action. It coagulates albumin. Its irritant action is explamed m part by the liberation of nitric acid at the time of its coagulant action, albumin taking the place of the acid in the combination. In connection with the application of this drug it may be remarked that a catarrhal condition does not need a constant irritant. The restoration of the ^-ascular tone will occiu* slowly under the influence of a decided local stimulant applied not too frequently. For the best effect, therefore, nitrate of silver should not be applied oftener than once a day or once in two days. In general, any strength of solution may be used up to 5 per cent., although this strength is decidedly irritating. Any excessive action may be prevented by promptly neutralizing with a solution of sodium chloride. This drug cannot be used in a mouth wash nor upon visible surfaces, because it blackens tissues and fabrics wherever it touches and may stain tooth structure. The solutions of siher nitrate are neutral. As a rule it is not prescribed in combination with other substances. Cupri Sulphas. — Sulphate of Copper. — Blue Vitriol [CUSO4 + 5H2O]. This substance occurs in blue crystals with a metallic, nauseous taste, soluble in 2.5 parts of water, 2.8 parts of glycerin and in 500 parts of alcohol. The solution is acid in reaction. It coagulates albumin. It ranks with silver nitrate as an irritating astringent, being even a mild caustic when used in the form of crystal or strong solution. The acid liberated in connection with its coagulant action is suljjhuric, one of the most irritating of acids. Its value in dental practice is limited, being useful for limited application where a decided, though irritating, astringent efi'ect is desired. If it is allowed to enter a carious tooth staining is likely to result. It occurs in colorless or whitish crj'stals or masses, having a slight odor and sweetish, astringent taste. It is somewhat efflorescent, absorbing carbon dioxide from the air; soluble in 1.4 parts of water and in 38 parts of alcohol, freely in glycerin. It is slighth/ alkcdine in reaction. It coagulates albumin, being one of the active mineral astringents. It is classed as a sedative astringent because of the absence of any marked irritation from its application. This fact agrees with the explanation that the acid of an astringent salt is liberated at the time of the coagulant action, being displaced by the albumin. In case of this substance acetic acid is liberated, which in its dilute form is not irritating. When used internally this drug presents the danger of lead poisoning. Therefore, its use is somewhat restricted as to quantity and length of time employed. In conditions of denuded surfaces, irritable ulcers, and acute local hiflammations of the gums, the solution may be employed, but swallowing the drug must be avoided. On account of this danger the lead preparations are seldom used internally, and even their external application to large surfaces may induce poisoning. For local use a simple solution of the salt in water or alcohol, or the official solutions of the subacetate may be employed. The latter contain a considerable amount of oxide of lead, which is soluble in a solution of the acetate with a change of the latter to the subacetate. The official diluted solution, known as lead^water, is of proper strength for ordinary use; or a stronger application may be obtained by diluting the stronger solution, which is known as Goulard's extract. A favorite application with some is the lead and opium wash* but the addition of the tincture of opium can contribute very little to the local action of the combination, except the astringent action of the alcohol it contains, as it is well known that opium has no appreciable local action. Among the evidences of saturation of the system by lead, there is noticed, especially in foul mouths, a blue line within the gum close to the margin. This is believed to be a deposit of lead sulphide within the tissue, and it is indicative of chronic lead poisoning only. (For symptoms, etc., of acute poisoning, see Table of Poisons and Antidotes.) Incompatibility. — Acetate of lead is incompatible with most acids which displace the acetic acid, with iodide of potassium and with liquor iodi compositus. The solution of the subacetate will precipitate solutions of acacia. Zinci Chloridum. — Chloride of Zinc [ZnCl2]. This substance is used more as an escharotic and antiseptic, but in the weaker solutions (1 to 10 per cent.) it is astringent. It coagulates albumin, but on account of the hydrochloric acid liberated the application of a strong solution is painful, and it is also quite penetrating. It is acid in reaction. Zinci Sulphas. — Sulphate of Zinc. — White Vitriol [ZnS04 + 7H2O]. Average dose, as emetic, gr. 15 (1 gm.). It occurs in colorless crystals or crystalline powder, having an astringent, metallic taste, soluble in 0.6 part of water and in 2.5 parts of glycerin; insoluble in alcohol. It is acid in reaction and it coagulates albumin. It is one of the feebler astringents, well adapted to the more sensitive mucous membranes, as the conjunctiva of the eye. In acute conjunctivitis and in acute disease of the antrum, it is a useful astringent in 1 per cent, solution. About the mouth it may be used stronger, as it is not irritating to the oral mucous membrane. It is a reliable emetic frequently employed to empty the stomach in cases of poisoning. In such emergency a dose of 30 grains (2 gm.) may be given. their carbonates and with ammonium sulphide. Zinci lodidum. — Iodide of Zinc [Znl2] (not official). — This salt occurs as a white powder, having a sharp taste, very deliquescent, and becoming brown upon exposure frorri the liberation of iodine. It is freely soluble in water and alcohol, and is acid in reaction. Its action is chiefly alterative combined with the characteristic action of the zinc ion. Dr. E. S. Talbot, after considerable experience with it, advises its use in interstitial gingivitis in the following combination with iodine, to which he gives the names of lodo-glycerole : preparation and to make it more astringent. Zinci Oxidum.^ — Zinc Oxide [ZnO]. A very fine white or yellowishw^hite powder, without any gritty quality. It is odorless, tasteless and insoluble in water or alcohol. It is a feeble astringent, very mild and even soothing in effect, so that it may be applied to any irritated or denuded surface. Either in simple powder or in the official 20 per cent. ointment it is largely used in diseases of the skin. It is not used internally. An important group of hemostatics comprises those whose chief action is upon the bloodvessels. The term styptic is often used to designate these. Either by local action when directly applied, or by stimulating the vasomotor nerve supply, they induce contraction of the muscular coat of the smaller arterial vessels, thus favoring coagulation by lessening the capillary circulation. They do not coagulate albumin. They are applicable only in hemorrhages of the smallest vessels, and particularly those in which unstriped muscle tissue is sufficiently abundant to be a factor in controlling the blood supply; for these agents act only through direct or indirect stimulation of the layer of unstriped muscle in the wall of the vessel. Where this is deficient, as in bone, they are likely to be inferior to coagulant agents. Those that act locally are of greatest importance to the dental practitioner and will accordingly be first considered. Antipyrina. — Phenazone [C11H12OX2]. Average dose, gr. 5 (0.3 gm.). This substance is obtained, by a series of chemical reactions, from pyrrol, a base found in coal-tar. Chemically it is phenyldimethylpyrazolon, which term shows the impracticability of using the chemical names of many of the newer drugs. Classed generally as an antipyretic and analgesic it was among the first of the coal-tar derivatives introduced to medicine. It occurs in colorless crystals, having a bitter taste, neutral, soluble in less than 1 part of water and in 1.3 parts of alcohol, also soluble in 1 part of chloroform and in 43 parts of ether. It is not a coagulant. Its hemostatic value is purely local. If applied or sprayed upon a bleeding surface, in the strength of 10 per cent, solution, it has the power to cause contraction of the arterioles, and in this way will efficiently control any ordinary capillary hemorrhage. It will be less efficient than a coagulant hemostatic in checking hemorrhage from a tooth socket, because of the deficiency of muscle in the vessel walls in bone. It is a harmless drug when applied as above, for one-half of a fluidounce (15 mil.) of a 10 per cent, solution may be used without exceeding the maximum internal adult dose. It is useful in stopping epistaxis (nosebleed), the solution being sprayed into the nostril. Its uses as anodyne and sedative are discussed in another place. Incomfaiihility . — ^The aqueous solution is incompatible with a dilute solution of carbolic acid; also with spirit of nitrous ether when the latter is acid^ as it is likely to be ordinarily; also with solution of tannic acid. Suprarenalum Siccum. — Dried Suprarenal Glands. — ^Average dose, gr. 4 (0.25 gm.). Unofficial preparations: Epinephrine, adi'enalin, adnephrin, suprarenin (synthetic) and adrenin. A preparation much used is a solution of adrenalin chloride in 1000 parts of physiological salt solution. The active principle of the suprarenal glands was first isolated by Abel (Cushny) and has been named epinephrine. It is found only in the medullary portion of the gland. Takamine later isolated another substance, adrenalin, which is claimed to have all the properties of the gland substance. \\hen an extract of the gland is injected into a vein, there occurs an immediate rise of blood-pressure which is more or less proportional to the strength of the extract. The rise in blood-pressure is accompanied by a slowing of the heart due to reflex stimulation of the cardio-inliibitory center excited by the rise of blood-pressure; when this reflex slow- The chemical nature of the extract has been worked out and has made it possible for the chemist to prepare a synthetic substitute together with a series of related substances having a similar nature. By careful studies it has been found that the extract of the gland and related substances cause the rise in blood-pressure by stimulating the nerve jfibers of the sympathetic nervous system distributed to the muscular coats of the bloodvessels. It is on this account that a weak solution of the extract is used to stop hemorrhage. While this substance will stop hemorrhage by constricting the arterioles, it reduces the coagulability of the blood and secondary hemorrhage may follow. It shoukl be applied locally and is especially useful in capillary hemorrhage. On account of its vasoconstrictor action it is a useful adjunct to the local analgesic solutions, making them more efficient by localizing the action and lessening absorption into the circulation. The synthetic preparations are claimed to be more stable in composition and can be boiled in solutions wdiich are for immediate use. For dental uses the usual dose is 1 drop of the 1 to 1000 solution of adrenalin, or of the synthetic preparations, to each cubic centimeter of the anesthetic solution with a maximum of 5 drops at any one time (Prinz). Acidum Gallicum. — Gallic Acid [CvHeOs + H2O]. Average dose, gr. 15 (1 gm.). An organic acid, prepared from tannic acid, having a rather uncertain reputation as a general styptic — i. e., acting throughout the system after absorption into the circulation. It occurs in whitish crystals, having an astringent taste, soluble in 87 parts of water, in about 5 parts of alcohol, and in 10 parts of glycerin. It is acid in reaction. It does not coagulate albumin, therefore it has no appreciable local action. It may be given internally in a dose of from 5 to 20 grains (0.3-1.3 gm.). It is not much to be relied upon, still it is recommended by some in the hemorrhagic diathesis and to control internal hemorrhages that cannot be reached by local medication. Ergota. — Ergot of Rye. — This fungus, which replaces individual seeds of the grain, is sometimes called "spurred rye." The pieces are one-half to one inch long, fusiform, slightly curved, purplish-black, hard, and breaking transversely. Fluidextractum Ergots. Average dose, TU 30 (2 mils.). While this drug contains several alkaloids, none is regarded as representing its full action, therefore the preparations of the whole drug are preferred. Uses as a Hemostatic. — Ergot is really useful only as it induces contraction of unstriped muscle in the arterioles. Capillary hemorrhages that cannot be treated locally call for its administration by stomach or, in emergency, hypodermically. The fluidextract is the preparation most commonly employed, in doses of J-l fluidram (1-4 mils.). In hemophilia (hemorrhagic diathesis) it is one of the drugs recommended. It should never be used in case of hemorrhage from a It is one of the drugs used to control postpartum hemorrhage. This dangerous complication after labor is due to relaxation of the unstriped muscle which is so abundant in the parturient uterus. Ergot stimulates this to powerful contraction, thereby closing up the uterine sinuses from which the bleeding has occurred. Cotarninse Hydrochloridum. — Cotarnine Hydrochloride. — Stypticin. — [C12H14O3NCI]. Average dose, gr. 1 (0.06 gm.). A yellow crystalline, odorless powder, derived from narcotin, an opium alkaloid. It is very soluble in water and in alcohol, and is neidral. It causes contraction of the unstriped muscular tissue of arterioles and of the uterus and is, therefore, used in hemorrhages from small vessels and from the uterus. It may be applied locally or given internally. Hydrastininae Hydrochloridum. ^ — Hydrastinine Hydrochloride [Cn H11O2X.HCI]. Average dose, gr. \ (0.01 gm.). Hydrastinine is an artificial alkaloid obtained by oxidizing hydrastine, an alkaloid of hydrastis. It is an odorless white powder, very soluble in water and in alcohol, and is neidral or slightly acid. It is used internally to secure constriction of arterioles both in hemorrhages and in catarrhal conditions. Besides the application of cold, which has been considered in the earlier part of the chapter, there are several agents which comprise the group of arterial sedatives. The most prominent of these are: ^ Aconitum. — The root of Aconitwn naiJeUvs. The tincture is the preparation commonly used, the average dose of which isTU 5 (0.3 mil.). For its precise action, see Plate XIV, under Sedatives. Veratmm. — The root of Veratrum mride. This drug is so similar in action and uses to aconite as to require no special discussion here. Average dose of the tincture, lU 8 (0.5 mil.). Remedies that Increase the Coagulant Property of the Blood. Within recent years there has been a decided gain in our resources for treating cases of persistent hemorrhage due to various causes, including those that present deficient coagulation of the blood. The remedies employed may not all act in the same way, but each has been sufficiently successful to entitle it to trial in any severe hemorrhage and particularly in cases of hemophilia. Since it is generally held that calcium salts are essential to the blood reactions that precede coagulation, these have come to be used with confidence in persistent hemorrhages. The chloride and lactate are efficient. Chemically pure calcium chloride occurs usually in hard white fragments, which are very deliquescent, odorless and have a sharp, saline taste. It is neutral, soluble in 1.2 parts of water and in 10 parts of alcohol. When given internally it is believed to increase the coagulability of the blood. Good reports have been made of its value in hemophilia, used both locally and internally. A dose of 5-10 grains (0.3-0.6 gm.) may be given every four or six hours. For local application a 5 or 6 per cent, solution in water has been employed. Parry* reports a case of hemophilia in which a persistent and alarming hemorrhage from the gums was checked by the local application of a 6.25 per cent, solution (30 grains to the fluid ounce). This drug certainly deserves a trial in any case of persistent hemorrhage. Calcii Lactas.— Calcium Lactate [Ca(C3H503)2 + SHoO].— Average dose, gr. 8 (0.5 gm.). This is the hydrated form of the salt. It occurs in white, granular form or in powder, odorless and nearly tasteless. It is soluble in 20 parts of water, almost insoluble in alcohol. Usually neutral. Though less soluble than the chloride, it is better tolerated by the stomach in case of prolonged use and seems to be equally efficient. Gelatinum. — Gelatin. — Gelatin is soluble in hot water, acetic acid or glycerin. It is insoluble in cold water, but absorbs from five to ten times its own weight, forming a jelly. Obtained from the skins and bones of animals, gelatin may be contaminated with the bacillus of tetanus, the spores of which resist ordinary sterilization by boiling. Because of this, Woodf states that "the hA^Dodermic use of commercial gelatm is not to be thouglit of." The same danger of tetanus would obtain with intravenous use, with the added danger of thrombosis. Therefore none but a specially prepared gelatin* should be used. By mouth the dose is 5 \|-1 (15-30 gm.) of the gelatin, in form of a 10 per cent, jelly, every three or four hours. Thyroideum Siccum. — Dried Thyroid GL.\:^rt)S. — Average dose, gr. 1\| (0.1 gm.). Both the extract of the th\Toid gland of the sheep or of other domestic animals, and the dried gland substance itself, have given such striking results in the treatment of myxedema, that its administration has been resorted to experimentally in many conditions. Especially in disorders of nutrition and in diseases of the circulating fluids, where absence of the thyroid secretion might be a causative factor, this substance has been tried. Regarding its value in hemophilia, a very satisfactory result is reported of a case by Fuller. f The patient was a boy, aged fifteen years. Four maternal uncles and two elder brothers had bled to death. The patient had frequent copious hemorrhages from the nose and also bled se\'erely with the loss of temporary teeth. For a year he had been in a very weak condition caused by spontaneous attacks of hemorrhage from the kidneys. After failure with the usual remedies, 5 grains (0.3 gm.) of thyroid extract were given three times daily. After the second dose the bleeding ceased. The case was reported nine months after, during which time there had been no recurrence of hemorrhage. a trial in any condition attended by persistent hemorrhage. Blood Serum. — Precipitated Blood Serum (not official). — An anhydrous, sterile powder, readily soluble in water. The usual dose is 8 grains (0.5 gm.) dissolved in sterile water and given subcutaneously, which is equivalent to 10 mils, of whole serum, and this may be repeated frequently. Human blood serum and also serum from the blood of the horse and the rabbit have been used with marked success in persistent hemorrhages where coagulation is deficient. The results reported by Welch J in cases of hemorrhages in newborn children, * "Under the name of Gelatina slerilizate pro injectione, Merck has marketed a 10 per cent, solution manufactured from specially selected material and sterilized by heating to 11.5° C. Of this preparation 5f 2—4, representing I5 to 3 drams of gelatin, may be injected subcutaneously, preferably after dilution with hot physiological salt solution." Ibid. REMEDIES THAT CAUSE DIRECT PRESSURE 113 and by Clowes and Busch* in a variety of cases, with reports by other observers, have given blood serum an important place among* our remedies. The precipitated serum is preferred to fresh serum, and that of the horse is most satisfactory. The conclusions of Clowes and Busch in regard to this remedy are as follows if 2. Human serum is in no wise superior to that of a variety of animals. 3. Blood serum precipitated by means of a suitable mixture of acetone and ether is fully as effective as fresh serum, if not superior to it. Precipitated serum is freely soluble and possesses the advantages of being sterile, always available, and retaining indefinitely its capacity to stimulate coagulation of the blood. 4. The product obtained from horse serum appears to yield more uniformly satisfactory results than that obtainable from the sera of other animals, and very seldom exerts any deleterious influence. Mechanical Hemostatics. — Under this heading are included surgical measures, such as pressure, ligatures and torsion. Pressure may be made directly upon the bleeding-point, or upon the artery of supply at some near point where it may be more effectually applied. Ligatures are intended to completely occlude the bleeding vessel, leading to its obliteration beyond. Torsion means twisting of a vessel. Small vessels that are not easily ligated may be treated in this way. In case of persistent bleeding after extraction of a tooth, the most effectual remedy is pressure, for the application of which the tooth socket and the occluding jaw opposite are well arranged. A cork may be shaped with the knife and file to conform to the root of the extracted tooth, and, after sterilization by boiling, inserted into the bleeding socket. It is also recommended that warm wax or modeling compound be first inserted and the cork pressed into it. A rather simpler method will be to roll hemostatic cotton firmly into a cone of proper size to fit the socket tightly. Its fibrous nature aids coagulation, though the cotton plug will be less solid than a cork. After insertion, a cork or firm pad of gauze is placed between the plug occupying the socket and the opposing jaw, or the teeth contained in it, so as to have mable, and must not be handled in the vicinity of a flame. Collodium. — Collodion. — ^A varnish that consists of a solution of 4 parts of p;\Toxylin in 75 parts of ether and 25 parts of alcohol. It is applied by means of a camel's hair brush upon a thoroughly dried surface. By rapid evaporation of the liquids its volume contracts, and considerable pressure is exerted upon the underlying tissue. It is applicable only to slight superficial hemorrhages. Collodium Flexile. — Flexible Collodion. — In this preparation 2 parts of camphor and 3 parts of castor oil are added to 95 parts of collodion. Its flexible character adapts it to use over movable parts, such as the lips, or about a joint. Collodium Stypticum. — Styptic Collodion (not official). — In this the formula is modified so as to contain 20 per cent, of tannic acid, which adds coagulant power and furnishes a more powerfully styptic combination. The class of hemostatics would not be sufficiently discussed without mention of a drug not usually included in the class, but one that is nevertheless valued highly in its distinct application to cases of hemorrhage. Opium.— (For description and detailed action, see under Sedatives.) This drug, of general systemic action, is mentioned here only for its value in aiding to restrain certain kinds of hemorrhage. It cannot be classed with any of the preceding drugs, for it has neither coagulant nor vasoconstrictor action; but it is by its power to put the system at rest that it becomes so valuable in the treatment of internal hemorrhages. Bleeding from the lungs requires that cough be restrained and respiratory excitement allayed; intestinal hemorrhage requires that the bowel be held quiet; and in either case mental excitement and apprehension must be removed. Opium, or its alkaloid, morphine, will accomplish all of this. In fact, the element of nervous excitement may aggravate almost any kind of bleeding and call for the use of opium or morphine for its removal. Morphine in moderate dose is usually employed, by stomach or, if the case is urgent, hypodermically. DETERGENTS. The term detergent, meaning a cleansing agent, applies rather to one of several uses to which certain agents are put. These, in their more important designation, are usually alkalies or antiseptics; therefore, it seems unnecessary to make a separate class of detergents. ]Many of the alkalies and milder antiseptics are well adapted to the cleansing of the mouth, teeth, throat and nasal chambers, while the stronger disinfectants and even corrosive agents are adapted to the cleansing of foul ulcers, putrescent pulp canals, etc. For the former uses, agents that do not coagulate albumin will be most useful, for a certain degree of penetration, especially into the recesses between the teeth, is desirable, which might be hindered by coagulation. For the latter uses, destruction of diseased tissue, bacteria and decayed matter is necessary, calling at times for the strongest chemical drugs. Again, in dentifrices one kind of detergent contributes the scouring quality, as prepared chalk; another kind will thoroughly cleanse all surfaces and remove fatty matter, as soap; and still another may be desired to exert a solvent or a penetrating influence. Hydrogen peroxide is a very important detergent besides being an antiseptic. Its action is a double one: (1) Lpon coming into contact with blood, pus or loosely organized tissue, it is decomposed, yielding nascent oxygen, by which it acts as an oxidizing agent and antiseptic. (2) The freeing of ox^'gen causes gaseous expansion, by which foul materials may be loosened and carried away from the tissues mechanically. Antacids are agents that are capable of neutralizing acids by reason of either their alkaline or basic properties. Alkalies are known by their power of changing the color of red litmus to blue. 116 DETERGEXTS, AXTACIDS AND ALKALIES some instances, where a simple alkali is used, such as lime-water or magnesia, the chemical change is a simple one, while with the use of sodium bicarbonate or prepared chalk, there is decomposition with evolution of carbon dioxide, and new combinations result in which the acid quality is lost. The importance in dentistry of the various substances belonging to this class is readily appreciated. With the tendency toward acidity of the fluids of some mouths; with the vitiation of the same in disease; and with the very common presence of fermentation in food particles which are allowed to remain between the teeth, we have factors of prime importance in the causation of caries; and in the recognition of these factors we have also the basis upon which to found our prophylaxis. The judicious use of antacids becomes a necessity, at least for the purpose of meeting temporary conditions, recognizing, however, that proper care of the teeth requires also proper care of the mdividual as to general health and all nutritive processes. As a rule that scarcely admits of exception, all mouth washes for continued use, and all dentifrices, should be alkaline or antacid; but in the prevention of caries we recognize that antacids per se do but one thing — ^they neutralize acids. The prevention of acid formation is equally important, and involves, besides strict local cleanliness, the use of an antiseptic to arrest fermentation, which is the very common source of the acid, or the use of an agent that is both antacid and antiseptic. Furthermore, when acidity of the oral secretions persists in spite of local treatment, the condition of the general system must be considered, particularly as to disorders of digestion or errors of diet, which ma>" be the cause of the condition. The difference in solubility of the several antacids in ordinary use gives them a wide range of adaptability in dental practice. To illustrate: For the purposes of a mouth wash a soluble alkali is needed; here sodium bicarbonate, lime-water or borax are applicable. For use in the mouth of a young child, where rinsing the mouth is impracticable, the gelatinous hydrated magnesia may be applied quite thoroughly by means of a cotton swab, or injected between the teeth and the cheeks, where, because of its thick consistence, it will adhere and remain in contact for some time; and, again, in case of erosion, where a soluble substance would be rapidly washed away, the insoluble prepared chalk may be packed between and about the teeth, and its neutralizing action will continue for hours, or through the night if applied at bedtime. ANTACIDS 117 The excessive or continuous use of antacids may disturb gastric digestion to just the extent that they are allowed to reach the stomach during the first two or three hours after meals. During this time the natural acidity of the gastric juice is needed and the entrance of much alkali mto the stomach might hinder digestion by neutralizing the acid. Otherwise no harm is likely to arise from their use. Soaps. — Soaps are compounds of the ordinary fat acids (oleic, palmitic; and stearic) with bases. Strictly speaking, all metallic salts of oleic, palmitic and stearic acids are soaps; but only those of potassium, sodium and ammonium are soluble. Whatever the consistence of the oil or fat emplo}'ed, its reaction with sodium will produce a hard soap and with potassium a soft soap. Lead plaster is a familiar example of an insoluble soap. Sapo. — Soap. — Wkiie Castile Soap. — It occurs as a white or whitish solid prepared from sodium hydroxide and olive oil. It should be hard, but easily cut M^hen fresh, and free from rancid odor. It has an unpleasant alkaline taste and an alkaline reaction. It is soluble in water and in alcohol. It contains about 21 per cent, of water, which may be largely removed by drying at an elevated temperature, when the soap may be more readily pulverized. It is capable of dissolving fats, which property gives it its great value. ^Medicinally it is alkaline and somewhat antiseptic, possessing detergent qualities in marked degree. Its chief dental use is in dentifrices, where, in powdered form, it may be mixed with any other agent in common use. As soap is irritating to the mucous membrane, unless well diluted, the mixture should not contain more than 25 or 30 per cent. Colored or marhled castile soap is less pure, as it contains ferruginous coloring matter. It is more strongly alkaline, harder, containmg only about 14 per cent, of water, and is, therefore, more economical for ordinary uses. Sapo Mollis. — Soft Soap. — ^A soft, yellowish or brownish mass, prepared from potassium hydroxide and cotton-seed oil, and containing an excess of the alkali. It is freely soluble in water and in alcohol. It has a slight odor and alkaline taste and is irritating to mucous membranes because of the free alkali contained. It is used preparatory to surgical operations as a cleansing agent for the hands of the operator and the site of operation. For this use it is diluted with alcohol and the parts are thoroughly scrubbed with IjicoinjMtibility. — Sokible soaps are incompatible with all acids and with earthy and metaUic salts; they are precipitated in hard water, or in a solution of corrosive suhlimate, as an insoluble soap. Sodii Bicarbonas. — Bicarbonate of Sodium [XaHCOs]. — A white, opaque powder, having a mildly alkaline taste, soluble in 10 parts of water, insoluble in alcohol. It is alkaline in reaction. Average dose, gr. 15 (1 gm.). Although the carbonates of the alkalies are more soluble and more strongly alkaline than the bicarbonates, the latter are preferred for dental uses because they are milder and less unpleasant to the taste. For similar reasons the sodium salts are preferred to the potassium. Sodium bicarbonate is the one usually selected for internal use, as it answers every purpose of an alkali without being at all irritating. In stomatitis due to fermentative conditions and in constitutional disorders that cause vitiated oral secretions, this drug is useful used alone or in combination with an antiseptic. As a mouth wash or gargle it may be used freely in saturated solution (10 per cent.). It may enter into dentifrices simply as an alkaline ingredient, as it is not antiseptic nor does it contribute any scouring quality. It is useful to neutralize the mouth after any acid or acid iron preparation has been taken or used locally. It is used also, by direct application, to lessen the sensitiveness of dentine when this is due to acidity. Internally the drug is used to neutralize hyperacidity in the stomach, and in the various acid intoxi-cations of the system, such as rheumatism. The internal dose is 5-30 grains (0.3-2 gm.). In connection with sterilization of instruments by boiling, sodium bicarbonate is oftentimes added to the water in order to lessen the liability of rusting. Incoinyatihility. — This salt is incompatible with all acids, producing effervescence with liberation of carbon dioxide. In solution it is changed by boric acid into sodium carbonate and borax, with liberation of carbon dioxide. (If carbonate of sodium be present, reaction may occur with either magnesium sulphate or mercuric chloride in solution,a brown-red precipitate being thrown down.) Sodii Boras. — Borate of Sodium. — Borax [Na2B407 + lOIIoO]. A^■erage dose, gr. 12 (0.75 gm.). It occurs in colorless crystals or white powder, having an alkaline taste, soluble in 15 parts of water and in about 1 part of glycerin, insoluble in alcohol. It is aJkaJine in reaction. This salt is also known as sodium biborate, tetraborate and pyroborate. It occurs naturally in many volcanic regions, our American supply coming chiefly from Nevada and California. It is also prepared artificially upon a commercial scale. In borax we have an agent that is both alkaline and antiseptic, and that may be used freely in satm-ated solution (6.6 per cent.). It is, therefore, admirably adapted to all uses that call for a mouth wash possessing the above qualities. In stomatitis and in thrush especially it is a superior agent. The latter disease occurs mostly in young infants where a mouth wash cannot be so well employed. Here, before the eruption of any teeth, we may use a saturated solution in glycerin, made by dissolving the powdered borax in hot glycerin, which will insure saturation when it has cooled. Glycerin itself is a preservative, and the resulting thick, sweet solution may be applied by means of a swab to all parts of the infant's mouth. In dentifrices borax will contribute antacid and antiseptic properties. This drug is seldom given internally. Incompatibility. — Borax in saturated aqueous solution is decomposed by mineral acids, with the precipitation of boric acid, which is slightly less soluble. A white precipitate is also thrown down by corrosive sublimate. Special interest attaches to borax because of its peculiar behavior with certain other substances. Thus,* "It is incompatible with mucilage of acacia, causing gelatinization, which can, however, be prevented by the presence of sugar; it precipitates many alkaloids from their solution, such as cocaine, morphine, atropine, quinine, etc., except in the presence of glycerin; it forms a damp, almost moist, mixture when triturated with alum; in the presence of glycerin it decomposes alkali carbonates with effervescence; and, lastly, while an aqueous solution of borax shows an alkaline reaction toward litmus, a solution in glycerm has a decided acid reaction, which is changed to alkalme upon large dilution with water," Liquor Calcis. — Solution of Calcium Hydroxide. — Lime-water. — Average dose f5 4 (15 mils.) or a tablespoonful. An aqueous solution containing not less than 0.14 per cent, of calcium hydroxide [Ca(0H)2]. It is readily prepared by treating freshly slaked lime with water. It is strongly alkaline in reaction, almost tasteless and very agreeable to the stomach. It may be used freely as a mouth wash and to correct undue aciflity of the stomach. For the latter purpose it is very commonly added to the food of infants, especially in the digestive disorders occurring during the summer, when the milk so easily loses its normal alkaline quality. Incomixiiihility. — Carbon dio.ride gas produces in lime-water a cloudiness, due to calcium carbonate. Oxalic acid produces a white precipitate of calcium oxalate. With corrosive sidiUmaie a yellowish precipitate occurs, and with calomel a black deposit. Magnesii Oxidum. — Light Magnesia. — Magnesia [MgO]. — x\verage dose, gr. 30 (2 gm.). The light magnesium oxide is prepared by exposing light magnesium carbonate to a dull-red heat. It is a white, very light powder, having a slight earthy taste and alkaline reaction. It is insoluble in alcohol, almost insoluble in water, but when mixed with 15 parts of water and allowed to stand for half an hour it gelatinizes, forming magnesium hydroxide or "milk of magnesia." (See Magma Magnesise, below.) This drug is an agreeable antacid for stomach administration, and is at the same time laxative. This combination of properties makes it a useful agent for the treatment of intestinal disorders of childhood, the alkaline quality serving to neutralize any undue acidity, and the laxative action ridding the bowel of offensive contents. When used thus internally it should be given in not less than 20 parts of water to prevent the formation of a gelatinous mass. moisture and carbon dioxide, forming a carbonate. Magma Magnesise. — Milk of Magnesia. — ^Average dose f5 2^ (10 mils.). A thick, white liquid containing about 7 per cent, of magnesium hydroxide [Mg(0H)2] in suspension in water; alkaline in reaction. Milk of magnesia is one of the most useful agents to neutralize acids in the mouth, being ranked first by some practitioners. This preparation is easily made in the way mentioned above and it keeps well. Its gelatinous consistence causes it to adhere to the teeth and remain about them for a considerable time, which is a decided advantage. In infants it may be applied by means of a cotton swab to the inside of the cheeks and throughout the mouth. It may be used freely in any mouth and at any age. Gi^'en internally, it has the antacid and laxative action of magnesia, the latter being aided by following the dose with lemon juice or other mild acid. Creta Piaeparata. — Prepared Chalk [CaCOs]. Average dose, gr. 15 (1 gm.). This substance is one kind of calcium carbonate. It occurs in form of a whitish powder, which is often moulded into the shape of small cones. It is odorless and nearly tasteless, almost insoluble in water, insoluble in alcohol, soluble in acids with effervescence and chemical change. It is not properly an alkaline substance, but an antacid, i. e., it neutralizes acids, but does not turn red litmus blue. Its action consists of a chemical union with any free acid, which displaces the carbonic acid of the chalk. It may be used freely internally, as an antacid in gastric and intestinal disorders. While solubility of a drug is usually desirable in order to have rapid action, the insolubility of prepared chalk gives it a special place in dentistry. Having a mild scouring quality, and being antacid, it holds first place as a basis for tooth powders. Its insolubility also gives it a prolonged action as an antacid so that in a mouth with a marked tendency to acidity it may be packed between and about the teeth upon retiring, and its action will continue during the night. This use is regarded as very important in progressive cases of erosion, where the damage occurs mostly at night, when there is less saliva secreted and, accordingly, the secretions of the mouth do not become so well mixed, the mucus remaining upon the surfaces of the teeth and about the gum margin. The extreme sensitiveness of the dentine, which is present in these cases, may also be lessened by the continuous use of this agent within the cavities of erosion and decay and about the teeth. The accepted belief that sensitiveness of dentine is often due to irritation by acids, points to the use of prepared chalk during the preparation of any cavity where sensitiveness is marked. It is well to continue its use during several days preceding the final preparation for filling. (See Index of Drugs for preparations for internal use.) DILUENTS. WATER. MINERAL WATERS. The increasing recognition of various autointoxications of the human system as the most disturbing factors in many diseases, brings into prominence the use of diluents, especially water, in the aid of normal cell function thi'ough free elimination. Particularly after full development of the body, in other words after the play period of life has passed, the tendency to less active and a lessened amount of exercise, favors deficient oxidation of food substances and waste tissue materials, with resulting accumulations of partially elaborated products, which are more or less deleterious. A distinct group of diseases related to such causes, including gout, so-called lithemia, fermentative digestive disorders, chronic rheumatism, etc., give evidence of the extreme importance of aiding cell elimination throughout the body. If with lessened exercise the usual amount of food is still taken, the conditions are aggravated, a superabundance of nutriment being furnished to the tissues whose oxidation processes are below normal. Moreover, as age advances, with development completed,* many of the capillary bloodvessels disappear because no longer needed. The capillary circulation is accordingly less active and, with the factors of excessive food material and deficient oxidation cooperating, the tissues easily become clogged, so to speak, laying the foundation for the diseases mentioned. The presence of arteriosclerosis, which means hardening of the walls of the arteries, adds another contributing factor by lessening the uniformity of blood supply to the capillaries. The relation of these conditions to oral pathology is being emphasized today in classification and treatment of pericemental and alveolar diseases. Uric acid is recognized as a product of partial oxidation of nitrogenous waste, and has been regarded as a prominent factor in gouty disorders. At the present time, however, doubt is being thrown upon its importance as a poison to the system. Nevertheless it stands with a group of substances arising in the body through faulty cell activity, some of which are acid in nature. For the double purpose of washing these substances out of the tissues into channels of elimination and of diluting them, it is advisable to use water freely, with or without alkaline salts for antacid efli'ect. Various alkaline mineral waters are taken with good results, and the salts of lithium have had a recent extensive use; but many physicians now g'we preference to pure water. Distilled water, because of its greater solvent power, being de^•oid of salts, is preferred in some conditions. In whatever kind, the taking of water in the quantity of one or two quarts daily is an important part of the constitutional treatment of these conditions. Pure water is a diuretic and the addition of certain salts will uicrease this action, while others will induce a cathartic action. solutions of the cathartic and diuretic salts, while the latter permit of modification which places the kind and degree of the saHne action under our control. (See Cathartics and Diuretics.) Certain artificial combinations, in imitation of the formulas of popular mineral waters, are upon the market, e. g., artificial Carlsbad salts. These seem to meet the demand, but their employment, as well as that of any mineral water, should be based upon proper discrimination as to indications for their use. ANTISEPTICS. The term antiseptic in a general sense applies to the antagonism of sepsis- — i. e., to whatever measures are employed to prevent the growth and propagation of disease-producing bacteria, also to counteract their influence and to remove their noxious products. If, however, we anal}'ze modern antiseptic treatment, we find that the agents and means employed vary as to the precise part they play in bringing about the result. Another will not only destroy bacteria, but will remove the noxious properties of putrefaction and fermentation; this is a true disinfectanf. Another will inhibit the growth and propagation of bacteria without destroying them or removing their noxious products; this cannot be designated otherwise than as a simjih aniiseptic — preventing sepsis, but not removing it when present. A deodorant is an agent that removes or corrects an offensive odor. It is impossible, however, to make a distinct classification in accordance with these terms, for the reason that many agents belong to one or another class, according to the strength in which they are employed, being in strong solution germicidal or disinfectant, and in weak solution simply antiseptic. Other conditions, such as character of solvent, temperature of solution and character of bacteria, also modify our designation of the several agents.* An antiseptic may be germicidal to one kind of bacterium and only inhibitory to the growth of another. To the writer it seems better to employ the term aniisepiic in its general inclusive sense, to cover all agents employed to prevent, counteract and remove the influence of disease germs, and to further designate differences of action by using the adjective terms germicidal and disinfectant. * The efficiency of antiseptics can be stated only in a relative manner, since, as yet, there are no generally accepted standards. Rideal and Walker have ijroposed the "phenol coefficient" but the results have not justified its general acceptance. Briefly stated it means the result arrived at l)y dividing the figure indicating the degree of dilution of the disinfectant that kills an organism in a given time by that expressing the degree of dilution of phenol that kills the same organism in the .'ame time under exactly similar conditions. The intelligent use of antiseptics has been a matter of development during the past forty years, following closely the progress made in the science of bacteriology. When Pasteur in 1857 proved that the processes of fermentation and putrefaction were caused by the presence and growth of organisms, the way was prepared for investigation of septic conditions and special diseases. In 1875 Lister set forth the germ theory as applied to the infection of wounds. His work and methods were a great step toward realizing the aseptic surgical methods of today and are referred to by an eminent surgical writer* as having "brought about an entire revolution in surgery and surgical technic, and an entire reversal of the statistics of operations; where thousands formerly died, thousands now live, their lives being indirectly due to the labors of this one man and his following." Since then the specific organisms of many diseases have been discovered and the application of antiseptic agents has become more precise and the results more definite. In dental practice antiseptics must be regarded in relation to widely differing structures, as presented by the teeth, in their very hard mineral character, by the softer tissues of the mouth, and by the extremely delicate and sensitive tooth pulp. Indeed, two quite distinct fields are before the dental specialist in his study of antiseptic therapeutics. He has now to select his agents for mouth disinfection and again for tooth disinfection. For mouth treatment his antiseptics must be selected with regard to safety of the soft tissues; for tooth disinfection the application is of such limited extent, and the soft structures are so well excluded, that the main question is that of efficiency, the very strongest escharotics being eligible for use; then also treatment of the tooth pulp will require the selection of agents especially adapted to its condition. These considerations will lead to the use of the terms " mouth disinfection" and "tooth disinfection" in the discussion of antiseptics. The ideal condition to be aimed at in all surgical work is that of asepsis, or absence of disease germs. The operator seeks to begin his operation with perfect asepsis. To this end his instruments are sterilized by boiling, and the dressings by dry heat at a temperature of 230° or over, while his hands and the site of operation are treated with suitable disinfectants. Asepsis of the mouth is difficult of attainment, but the site of operation may be made relatively aseptic after exclusion of the fluids by a sterile rubber dam, and the condition then maintained today to secure asepsis. The importance of thoroughly sterilizing all instruments that have been used in the mouth, after each dental operation, must be insisted upon. There can be no doubt that one must frequently operate in a syphilitic mouth without being aware of it, because the lesions may be slight or invisible. In secondary syphilis the danger of carrying the disease to another mouth or of infecting a chance lesion upon the hand is very great, and preventable with certainty only by sterilization of instruments and appliances. Alcohol has been regarded as a disinfectant for this piu-pose, but its value is questionable. Absolute certainty should require sterilization by heat. Acidum Boricum. — Boric Acid. — Boracic Acid [H3BO3]. — Average dose, gr. 8 (0.5 gm.). This occurs in transparent, colorless scales or crystals, nearly tasteless, soluble in 18 parts of water, 18 parts of alcohol, and 4 parts of glycerin. It is sligJitly acid in reaction. This substance is found in various parts of the globe chiefly in the form of natural borates, the American market being supplied from the borax regions of California. The saturated aqueous solution of this drug {0.0 per cent.) is largely used as a mild antiseptic wash. It is non-irritating, therefore may be applied to the most delicate tissue. As an eye wash it is much used. It may be employed freely as a mouth wash, the only objection being its slight acidity. However, it must be said that it possesses no real advantage over its sodium salt. In powdered form it is used in tooth powders or dusted upon ulcers or wounds. carbonates, with the formation of borates. Glyceritum Boroglycerini. — Glycerite of Boroglycerix. — Whenever a stronger preparation of boric acid than the saturated solution is desired, it may be had in the official glycerite of boroglycerin, which contains 31 per cent, of boric acid incorporated by chemical union with glycerin. This may be used in full strength or diluted. It is neutral in reaction. Sodii Boras. — Borax. — Average dose, gr. 12 (0.75 gm.). This salt has been discussed under Antacids. As an antiseptic it may be used freely in saturated solution (0.6 per cent.) as a mouth wash, or the crystal may be allowed to dissolve in the mouth. Borax deserves a large use as a mild antiseptic since it possesses every essential quality PHENOL LIQUEFACTUM 127 of a mouth antiseptic, though one of the class of weaker agents. It is alkaline, non-irritating, almost tasteless and non-toxic. Dobell's solution* is a very useful combination. A saturated solution in glycerin (equal parts of each) is very efficient in the removal of the thrush fimgus (oidium albicans), which is so often seen in the mouths of bottle-fed infants. The thick consistence of this solution is advantageous in that it thereby adheres to the mucous membrane for some time. It should be applied several times daily. Sodii Perboras. — Sodioi Perborate [XaBOs + 4H2O]. — ^Average dose, gr. 1 (0.06 gm.). It occurs as white granules or powder, odorless, with a saline taste, stable in cool dry air, but losing oxygen in warm or moist air; soluble ui water; alkaline in reaction. It should contain not less than 9 per cent, of available oxygen. Sodium Perborate makes an efficient antiseptic mouth wash in ulcerative conditions of the mouth. It is important that it be prepared fresh each time, as the solution does not keep well. A teaspoonful in one-half glass of water is a proper strength. It produces its action by the liberation of nascent oxygen. Phenol. — Carbolic Acid. — ^Average dose, gr. 1 (0.06 gm.). This substance has been considered in its action upon the tissues, under Escharotics. In dilute solutions it is one of the most generally useful antiseptics. Although slightly acid in reaction, this substance is not an acid, chemically speaking. It is a coagulant when used in strong solution, and while this property may be a factor in its antiseptic action, its germicidal power may be thereby lessened b}' interference with penetration. but may be used upon the skin with care.* It is the proper strength for occasional disinfection of the hands, but its frequent use will make the skin rough, because of its coagulant action. As a mouth-wash or gargle it has the advantage of being slightly analgesic, but it should not be used stronger than 1 per cent. The slight acidity may be counteracted by combining a solution of sodium bicarbonate with it. For the purpose of tooth disinfection the pure phenol may be used in small quantity with due care. It is remarkable that the continuous application of a solution as wxak as 5 per cent, has been followed by gangrene, the result probably of thrombosis. This is especially liable to occur in a finger or toe wdiere all ^'essels of supply are equally affected. The local analgesic action undoubtedly aids in lowering the vitality of the part and prevents painful sensation, which otherwise might give warning of the danger. It may be said of this agent that, having been one of the first substances proposed as an antiseptic and disinfectant, it has held its place for more than forty years as one of the best drugs of the class. A solution of 1 in 250 will quickly destroy lower forms of vegetable life and check fermentation, a 1 per cent, solution may be relied upon as a general antiseptic, while a 5 per cent, .solution is an efficient disinfectant. As to its germicidal power, Harrington found that a 5 per cent, solution destroyed the Staphyhcoccus pyogenes mireus, the most common and most resistant pus organism, in two minutes; a 2.5 per cent, solution requu'ed four minutes, f In saturated solution it is useful to keep instruments in sterile condition during an operation. It has no action upon metals; therefore instruments may be disinfected by its use in full strength, bearing in mind always that any albuminous matter will be coagulated by it instead of being removed. The combination known as liquor sodii carbolatisj contains 50 per cent, of carbolic acid. TRICHLORPHENOL 129 Internally phenol is a valuable antiseptic. In doses of ^-2 minims (gm. 0.03-0.12), well diluted, it is used to arrest fermentation in the stomach and intestines, an advantage of its use being that it does not disturb digestion. When employing this drug, it must always be borne in mmd that it is a poison — corroswe when applied in full strength to tissue; and also a systemic poison when absorbed in quantity, producing irritation of the kidneys which may result in nephritis; therefore, caution should always attend its use, and in view of the frequency of poisoning by carbolic acid every practitioner should be prepared to treat the same in emergency. Albumin is a true antidote, while alcohol has some restorative action upon tissues; soluble sulphates have been employed. (See under Escharotics.) Incompatibility. — Phenol will coagulate albumin and collodion. In aqueous solution a white precipitate occurs with bromine water, with ferric chloride a violet color is produced, and with solution of antipyrin a white precipitate occurs. When the saturated aqueous solution is mixed with a solution of cocaine hydrochloride a white precipitate may occur. Cresol ~ Tricresol. — Cresylic Acid [CyHgO].— Average dose, lU 1 (0.05 mil.). A mixture of isomeric cresols obtained from coal-tar. It is a nearly colorless liquid, becoming yellowish or brownish upon prolonged exposure to light. Its odor is similar to that of phenol. It is soluble in 50 parts of water and in alcohol and glycerin. The uses of this substance are the same as those of phenol. It is believed to be a more powerful disinfectant. A 5 per cent, solution has been found to destroy Staphylococcus pyogenes aureus in two minutes.* Liquor Cresolis Compositus. — Lysol. — This solution contains 50 per cent, of cresol, with linseed oil and potassium hydroxide. It is liquid cresol soap. It mixes with water readily and in solution of from 1 to 5 per cent., it is largely used as a general antiseptic wash and disinfectant. It is a good hand disinfectant, although its odor may be objectionable. Trichlorphenol [CeHaClsOH] (not official).— The action of chlorine upon phenol produces a series of bodies whose antiseptic power exceeds that of phenol. Of these trichlorphenol is a definite crystalline substance, soluble in alcohol and ether. According to Nenckif a 2 per cent, solution was found to be more active than a 5 per cent, solution of mercury. Creosotum. — Creosote. — Oil of Smoke. — ^Average dose,Tn, 4 (0.25 mil.) . A mixture of phenols, chiefly guaiacol and creosol, obtained by distillation of wood-tar. In addition to the discussion of this substance in the class of irritants, its use as an antiseptic claims consideration at this place. Obtained usually from beechwood-tar by distillation, creosote is always liquid, nearly colorless when fresh, but becoming yellowish. The U. S. P. states that it should not readily become brown on exposure to light. It is neutral or only faintly acid to litmus paper. It is soluble in about 140 parts of water, and more freely in absolute alcohol, ether, chloroform and oils. In some respects it resembles liquefied phenol, but the latter acquires a pink or reddish color with exposure ; in odor it is somewhat similar, although decidedly smoky and unpleasant. It is less useful in dental practice, because of its odor and also the fact that it discolors teeth by continuous treatment. The chief points of difference between the two substances are given below^: Soluble in about 15 parts of water. Soluble in about 140 parts of water. In antiseptic power creosote surpasses phenol,* and its internal use is safer. In recent years it has been used extensively as an mternal remedy in the treatment of pulmonary tuberculosis, tolerance to quite large doses being readily acquired. It has a local analgesic and sedative effect, which makes it a valuable inhalant. In full strength creosote is an excellent tooth disinfectant, being preferred to carbolic acid by some, because it has little or no coagulant action, f It penetrates more deepty, but is less corrosive. As it is apt to discolor tooth structure it is not to be used in teeth that are visible. t It is stated by some authorities that creosote contains some carbolic acid and that it coagulates albumin. This was formerly true, when pure creosote was difficult to obtain and adulteration with carbolic acid was common; but at the present time pure creosote is easily obtainable and it has little coagulant action. However, creosote being amixture of substances, its properties may vary slightly. order to insure saturation. Although there has been a tendency toward eliminating creosote from dental uses, there is good reason to believe that it is a valuable antiseptic agent in the treatment of putrescent root canals. On the whole, it may be said that in dental practice creosote is used little compared with phenol, though a stronger antiseptic. Poisoning by this drug would occur by SM^allowing a quantity of it pure. The symptoms would be those of irritant poisoning. It has no definite chemical antidote. Emetics would be indicated, followed by demulcents. Creosoti Carbonas. — Creosote Carbonate. — A liquid mixture of carbonates of several constituents of creosote, chiefly guaiacol and creosol. Average dose, TTl 15 (1 mil.). This agent, being a mixture of substances, varies as to color, odor and taste. It may be colorless, odorless and tasteless, or it may be yellowish and have a slight odor and taste of creosote. It is insoluble in water, but soluble in alcohol and in fixed oils. It is less irritating for internal use than is creosote and, with similar uses in pulmonary diseases, it can be given in larger doses. Guaiacol [C7H8O2].— Average dose, gr. 8 (0.5 gm.).— A crystalline solid obtained from creosote and constituting from 60 to 90 per cent. of the latter. It melts at 82.4° F. It is soluble in 53 parts of water, 0.8 part of glycerin, but separating upon addition of water, and also soluble in alcohol and ether. Being a definite compound, it forms a number of combinations, some of which, as well as itself, are used as substitutes for creosote for internal administration. Guaiacol has been used as a vehicle for cocaine in its application by cataplioresis. Guaiacolis Carbonas.— Guaiacol Carbonate [(C7H70)2C03]. — Average dose, gr. 15 (1 gm.). A white crystalline powder, insoluble in water, soluble in 60 parts of alcohol, neutral and almost tasteless. Alcohol. — This drug, fully considered iti other places as astringent and stimulant, has a well-founded reputation as an antiseptic. Its action upon bacteria is probably due to its power of abstracting water and of coagulating albumin. It is less valuable as a disinfectant than as a simple antiseptic and as a vehicle for stronger agents of this class. It must be used in strength of 40 per cent, or more to have any decided antiseptic value; however, upon the dry skin the very strong alcohol (absolute and 95 per cent.) has been found less efficient than if it is diluted somewhat. This is due to the hardening effect of the undiluted alcohol which hinders penetration. power of alcohol in different strengths led to the following results: 1. Against dry bacteria, absolute alcohol and ordinary commercial alcohol are wholly devoid of bactericidal power, even with twenty-four hours' direct contact; and other preparations of alcohol containing more than 70 per cent., by volume, are weak in this regard, according to their content of alcohol ; the stronger in alcohol, the weaker in action. '2. Against the commoner, non-sporing, pathogenic bacteria in a moist condition, any strength of alcohol above 40 per cent., by volume, is effective within five minutes, and certain preparations within one minute. or dry. "4. The most effective dilutions of alcohol against the strongly, resisting (non-sporing) bacteria, such as the pus organisms, in the dry state, are those containing from (K) per cent, to 70 per cent, by volume, which strengths are equally efficient against the same organisms in the moist condition. "5. Unless the bacterial envelope contains a certain amount of moisture, it is impervious to strong alcohol; but dried bacteria, when brought into contact with dilute alcohol containing from 30 per cent. . to 60 per cent, of water by volume, will absorb the necessary amount of water therefrom very quickly, and then the alcohol itself can reach the cell protoplasm and destroy it. '6. The stronger preparations of alcohol possess no advantage over the 60 per cent, to 70 per cent, preparations, even when the bacteria are moist; therefore, and since they are inert against dry bacteria, they should not be employed at all as a means of securing an aseptic condition of the skin." Certain of the vegetable tinctures have a reputation as antiseptics, which with a few is well-founded. When we consider the value of the contained alcohol, it appears that any addition of a drug that has antiseptic power should produce a valuable preparation. Tinctura Myrrhae. — Tincture of Myrrh. — Average doscTH. 15 (1 mil.). — This has long been used as an application to the gums, and as an ingredient in mouth washes. To irritated, lacerated or spongy gums, ulcers, etc., it may be applied freely. It cannot be diluted with water, TINCTURA BENZOINI COMPOSITA 133 for the latter precipitates the resinous portion of myrrh. It can only be mixed with water or aqueous solutions in the presence of a large percentage of alcohol. A dilution of alcohol with more than one-third water will not mix with tincture of myrrh without precipitation occurring. Benzoin contains resin, benzoic acid (about 14 per cent.) and traces of a volatile oil. Benzoic acid has been found, by a number of observers, to rank among our very best non-irritating antiseptics, and it is freely soluble in alcohol; therefore, these tinctures should be valuable antiseptics, as they contain 1 to 4 per cent, of benzoic and cinnamic acids, the latter being also valuable. The compound tincture is a time-honored preparation, and one of the best antiseptic and stimulant applications to mucous membranes. An unhealthy or ulcerated condition of the gums calls for its use. It must be applied upon cotton. It cannot be used in a mouth wash because of the precipitation of the resin when mixed with water. Except the resinous portion, it may be vaporized with steam by being poured upon boiling water, and it thus forms a useful inhalant in irritable or infected conditions of the upper air passages. A useful prescription for this purpose is the following: For the correction of foul breath, when due to an unhealthy condition of tonsils or upper air passages, the same inhalation is useful; in addition the compound tincture may be applied in full strength to the surface of the tonsil and within all of its crypts that are visible. Foul breath may be due to the collection of solid offensive secretion within these crypts. This should be removed before making the application. Balsamum Peruvianum. — Balsam of Peru. — ^A balsam obtained from Toluifcra Percircp. — It is a thick, dark brown liquid, having an agreeable odor resembling that of vanilla. It is soluble in alcohol and in chloroform, partly soluble in ether and almost insoluble in water. Its value as an antiseptic depends upon benzoic and cinnamic acids and aromatics which it contains. It is rarely used internally, but is an agreeable and valuable application to ulcers and in parasitic diseases of the skin. Acidum Benzoicum. — Benzoic Acid [C7H6O2]. — Average dose, gr. 8 (0.5 gm.). An organic acid obtained from benzoin, or prepared artificially. This drug occurs in whitish crystals, with or without the odor of benzoin, has a pungent taste and is somewhat volatile. It is soluble in 275 parts of water, but with an equal quantity of borax it is soluble in 100 parts of water; soluble also in 2.3 parts of alcohol and in 10 parts of glycerin. It has an acid reaction. A solution of 1 to 400 has been found to destroy developed bacteria; and according to Miller, a 1 per cent, solution will accomplish ordinary disinfection of the mouth in one-quarter of a minute. With its solubility in water increased by borax, the two may be combined in aqueous solution to make a very efficient mouth wash. It is found that a saturated solution of borax will dissolve 1 per cent, or more of benzoic acid and still be alkaline. Incompatihiliiy. — When a solution of benzoic acid has been neutralized by an alkali, as with borax, a precipitate will occur when mixed with hydrochloric or dilute nitric acid, or with dilute solutions oi ferric salts or with lead acetate, mercuric chloride or silver nitrate. Acidum Salicylicum. — Salicylic Acid [CyHeOs]. — Average dose, gr. 12 (0.75 gm.). An organic acid obtained from vegetable sources or prepared from carbolic acid. It occurs in very fine, white needles or crystalline powder, having a sweetish taste. It is soluble in 4G0 parts of water and in 2.7 parts of alcohol, 2 parts of olive oil and 00 parts of glycerin. It is acid in reaction. According to Miller, f a 1 per cent, solution will accomplish ordinary disinfection of the mouth in onequarter of a minute. It must be ranked among our best antiseptics, but it is objectionable for continued use because of its acid reaction. The saturated aqueous solution is rather weak to be of much value as PHENYLIS SALICYLAS 135 a disinfectant; but a saturated solution of borax in water will dissolve 1 per cent, or more of salicylic acid and still be alkaline in reaction. Such a solution really makes an ideal mouth wash. The drug may also be used as a mouth wash either in combination with other antiseptics or in alcoholic solution diluted. Incompatibility. — ^^Vith 'potassium chlorate, hydrochloric acid, nitric acid, chlorine or a solution of ferric chloride, it undergoes chemical change. It causes gradual decolorization of a solution of potassium permanganate. With carbonates it effervesces, with the formation of salicylates. Sodii Salicylas. — Salicylate of Soditoi [XaC7H503]. — ^Average dose, gr. 15 (1 gm.). This salt is much more soluble in water than is the acid, being soluble in 0.9 part, also in 9.2 parts of alcohol and in glycerin. For internal use it is less disturbing to the stomach than salicylic acid, and it is used largely in the acute stage of rheumatism to control the fever and pain. It is not a very efficient antiseptic. Phenylis S-alicylas. — Salol [C13H10O3]. — Average dose, gr. 5 (0.3 gm.) It occurs in form of a white, crystalline powder, having a sweetish taste, almost msoluble in water, soluble in 6 parts of alcohol, and in ether, chloroform and oils. It melts at 42° C. (107.6° F.). Its use in dentistry depends upon the ease with which it can be fused, and the fact that, when fused at a tetnperature considerably above its melting-pomt, recrystallization is retarded. Mascort* in 1894 advocated its use in melted form as a root-canal filling. Being a feeble antiseptic unless decomposed, its ready adaptability and non-hritating character must be its chief recommendations. It is used either alone or in connection with a cone of gutta-percha. This substance is not often employed as a local antiseptic, because of its insolubility in water. It may, however, be used in alcoholic solution. Its chief use is as an intestinal antiseptic. Its adaptability to this use lies in the fact that, passing through the stomach unchanged, it is first decomposed into carbolic and salicylic acids by contact with the alkaline juices in the small intestine, where the effect of these tw^o antiseptic substances is then obtained. It is valuable in diarrheas and intestinal fermentation, but with large doses toxic effects of phenol are possible. VOLATILE OIL GROUP. Volatile oils are odorous, volatile principles, not possessing the chemical qualities of true oils. Since they are mostly obtained by distillation they are also called distilled oils; and, as they are usually the most essential constituent of the drug yielding them, they are also known as essential oils. While usually of vegetable origin, several are now made synthetically. ^"olatile oils are colorless or nearly so when freshly distilled, becoming, as a class, somewhat colored wdth age and exposure, without losing any of their valuable properties. They are insoluble in water, soluble in alcohol, ether, chloroform and fixed oils. The volatile oils as a class are antiseptics. Some have an analgesic effect when applied to sensitive tissue, while others are irritating and a few are poisonous. Some are not applicable to uses about the mouth because of unpleasant taste or odor. Most of them are used in full strength as disinfectants in root canals and in carious cavities, but by prolonged use they may discolor the tooth structure. Even with pulp exposure the non-irritating oils may be used. They do not destroy tissue, they do not coagulate albumin, hence they penetrate well, and any irritation from brief application is but slight and momentary. Exception to the last statement is found with oils of turpentine and mustard, but these are seldom used in the mouth because of their rank odor. Dr. A. H. He very properly holds that . the volatile oils and other agents have been used "without reference to their relative merits as antiseptics, or to their therapeutic effects upon the tissues to which they are applied." From these observations, a summary of which is given in the table following, he concludes that the oils of cinnamon (including oil of cassia), while high in antiseptic value, are too irritating to be used in root canals. Also that oil of cloves and creosote are superior agents, both being efficient antiseptics, while non-irritating to soft tissues. In fact, he found oil of cloves to possess local analgesic properties to a Antiseptic Power. Action on Soft Tissues. 10 c.c. of sterile mutton bouillon as culture medium. Growth TVTien confined to When sprayed of mouth bacteria prevented by skin by rubber cap. upon artificial sore amounts given below in drops. (guinea-pig). (Ratio varies as size of drop.) Ratio. eucalyptol was not very positive. * For article forming basis of this summary, see Dental Review, August, 1898. t Black's "1-2-3" mixture (mild) consists of 1 part oil of cassia, 2 parts phenol (crystals), and 3 parts oil of gaultheria. Oleum Cassias. — Oil of Cinxamox. — Oil of Cassia. — ^Average dose, TU 3 (0.2 mil.). A volatile oil distilled from Cassia cimiamoii (young twigs), containing not less than 80 per cent, of cinnamic aldehyde, and ha^■ing the odor and taste of cinnamon. It is yellowish or brownish in color, becoming darker and thicker by age and exposure; sp. gr. about 1.055; soluble in about 3 parts of 70 per cent, alcohol. The changes by age are due to the oxidation of cinnamic aldehyde to cinnamic acid and resins; therefore, the oil should be kept from exposure to light and air m well-stoppered, amber-colored bottles, in a cool place. The oil is frequently adulterated.* Oil of cinnamon is non-coaguknit to tissues, it is penetrating, it is agreeable in odor and the discomfort of its application to soft tissues is momentar}^, unless it is confined for some time, when it may cause severe irritation. It is doubtless the most powerful antiseptic of all the volatile oils used hi dentistry (see preceding table). It is used for tooth dismfection, but is less applicable to front teeth than to posterior ones, because of its discoloring effect with continued use, this being due to its tendency to become darker with exposure. It may be used in full strength in pyorrhea with deep pockets. Aquse destillatse q. s. ad 1000 Triturate the oil with the purified talc, add the recentlj^ boiled distilled water gradually with continued trituration, filter, and pass the filtrate through the filter repeatedly until the cinnamon water is perfectly clear. (It is estimated that onehalf of the oil is dissolved by the water.) The official cinnamon water is useful as a mouth wash and to irrigate fistulous tracts, as, according to Dr. Peck's report, it should be able to prevent the growth of mouth bacteria. It is very pleasant to the taste and can well be used in preference to proprietary liquids of complex composition and imcertain value. It may be used in full strength freely. Oil of cinnamon is an important ingredient in the formula of Dr. * Oil of cassia has often been found adulterated with a mixture of petroleum and rosin. The U. S. P. test for detection is as follows: Shake 2 mils, of the oil in a testtube with from 5 to 10 mils, of purified benzin, and decant the latter; this hquid is colorless and does not assume a green color upon shaking it with an equal volume of y\f per cent, copper acetate solution. Cixxa:mic Aldehyde [CgHjO] (not official;. — An aldehyde obtained from oil of cinnamon or prepared synthetically. It should be 95 per cent, in strength. It is nearly identical with the official oil of cinnamon, having the same qualities in general, but being more definite in composition. At a low temperature it becomes solid, melting again at 18.5° F. It is sparingly soluble in water, but soluble in alcohol, ether and oils. It uses are the same as those of oil of cinnamon. Oleum Caryophylli.— Oil of Cloves. — ^Ai-erage dose, TU 3 (0.2 mil.j. A volatile oil distilled from cloves (the flower-buds of Eugenia Aromatica) , varying in color from pale yellow to brown, age and exposure producing the change. It has the odor and taste of cloves, is soluble in 2 parts of 70 per cent, alcohol, the resulting solution ha\dng a slightly acid reaction. Sp. gr. about 1.050. Its chief constittient of value is eiigenol, of which it should contain 82 per cent. protected from light and air, so as to retard the same. Oil of cloves has a high antiseptic value (1 to 1150 for mouth bacteria), while Dr. Peck's experiments have proved positively that it is not only non-irritating locally, but that, when applied to inflamed or infected tissues, it is decidedly soothing, and healing progresses rapidly under its application. It is iwn-coagidant to tissue. It can be used freely as a tooth and root canal disinfectant, though its tendency to discolor prohibits its use in front teeth. It is entitled to a larger use as an application to irritated and infected tissues. In addition to its dental uses, oil of clo\'es is employed in the preparation of microscopic specimens. Eugenol [C10H12O2]. — ^Average dose TU 3 fO.2 mil.). An aromatic phenol, the chief constituent of oil of cloves, but obtainable also from other sources. Sp. gr. about 1.067. It is similar to oil of cloves in all of its qualities. It may be mixed with alcohol in any proportion and it is soluble in 2 parts of 70 per cent, alcohol. In Peck's observations it was found to be much inferior to oil of cloves {vide ante). Oleum Cajuputi.— Oil of Cajuput. — Average dose, TTl 8 (0.5 mil.). A volatile oil obtained from the fresh leaves and twigs of Melaleuca leucadendron. Its chief constituent is cineol (eiicalyptol) , of which there should be at least 55 per cent. Sp. gr. about 0.920. Oleum Eucalypti. — Oil of Eucalyptus. — Average dose, TTl 8 (0.5 mil.). Distilled from the fresh leaves of Eucalyjitiis globulus, this volatile oil owes its value to cineol (eucalyptol), of which it should contain 70 per cent. It is soluble in 4 parts of 70 per cent, alcohol, the solution being neutral. Sp. gr. about 0.915. It is similar to oil of cajuput because of the presence of cineol. It has no distinct value in comparison with other volatile oils, and preference is usually given to the following chief constituent, which is more definite than the oil. Eucalyptol. — Cineol. — Cajuputol [CioHigO]. — Average dose TTl 5 (0.3 mil.). An organic compound obtained from oil of eucalyptus and other sources. It is a colorless liquid with an aromatic, camphoraceous odor and a spicy, cooling taste. It is soluble in alcohol in any proportion, the solution being neutral. Sp. gr. 0.922. It should be kept protected from air and light. Eucalyptol has no special advantage over the stronger volatile oils, though regarded by some as especially detergent in root canals. It is non-irritating and non-coagulant. Its antiseptic value is shown in the table on p. 137. Oleum Gaultherise. — Oil of Wintergreen. — [Known now officially as Methylis Salicylas. — Methyl Salicylate] [CH3C7H5O3]. — Average dose, TTl 12 (0.75 mil.). This volatile oil is produced synthetically or distilled from Gautheria procumbens. From either source, it has the odor and taste of wintergreen. It is used chiefly as a flavoring agent Its antiseptic value is low. Thymol [C10II14O]. — A phenol, present m the volatile oil of Thymus vulgaris and some other volatile oils. Dose, gr. 1-30 (0.06-2 gm.). It occurs in large, colorless crystals, having a penetrating odor of thyme and an aromatic taste, soluble in 1010 parts of water, in about 1 part of alcohol, also soluble in chloroform, ether and oils. It is used as a general antiseptic, having a germicidal power similar to that of phenol, as a substitute for which it was introduced into medicine. It is less toxic than phenol. It is used also as an anthelmintic, being regarded almost a specific in hook-worm disease (uncinariasis) where it is given in the large dosage of from 1 to 2 gms. per day. Thymolis lodidum. — Thymol Iodide [C2rjH2402l2] ■ — This substance, known also as Aristol, contains 43 per cent, of iodine. It is a reddishyellow or brownish powder, insoluble in water and glycerin, very slightly soluble in alcohol, freely soluble in ether and in oils. It does not keep well unless protected from light. It is used as an antiseptic powder, and is applicable as a pulp-canal dressing. Oleum Menthse Piperitse.— Oil of Peppermint. — ^Average dose, TH 3 (0.2 mil. J. A volatile oil distilled from the flowering plant of Mentha piperita, yielding 50 per cent, of total menthol (5 per cent, as esters). It is colorless, neutral and soluble in 4 parts of 70 per cent, alcohol. It should be kept in a cool place and protected from light. It possesses a strong odor of peppermint. Its contact with tissue is followed by a sensation of cold. In form of the spirit (10 per cent.) it is given internally as a carminative. Locally it is analgesic and antiseptic, and is, therefore, useful to relieve itching of skin or mucous membrane, a 5 to 10 per cent, ointment or solution in alcohol being used. Menthol [C10H19OH]. — ^Average dose, gr. 1 (0.06 gm.). A secondary alcohol obtained from oil of peppermint or other mint oils. It occurs in colorless crystals having the characteristic odor of peppermint. It is only slightly soluble in water, freely soluble in alcohol, ether, chloroform and oils. When rubbed upon the skin there follows a decided sensation of cold to the part. This effect classes it as an analgesic and makes it a valuable application in itching (pruritus) of various parts. It may be applied in solution or in ointment. It is a useful antiseptic for internal administration and for local dental uses. As an analgesic antiseptic for use in pulp treatment it may be dissolved in chloroform or in a volatile oil. In neuralgias and headaches the solid crystal is rubbed upon the skin of the painful area. Oleum Terebinthinee Rectificatum.— Rectified Oil of TrRPEXTiXE. — ■ Average dose, TU 5 (0.3 mil.). This agent has been discussed in its more important use as an irritant. As an antiseptic it is chiefly used externally to disinfect the skin or the hands of the operator in preparation for surgical operations. Terebenum. — Terebene. — Average dose, 1TL 4 (0.25 mil.). The reaction between oil of turpentine and sulphuric acid yields a colorless liquid, known as terebene. It has an agreeable odor and aromatic taste, and it should rank among the vahiable antiseptics for local use. It is almost insoluble in water, but is soluble in 3 parts of alcohol. With exposure to light and air it gradually becomes resinified and acquires an acid reaction. It is used internally in bronchitis. HALOGEN GROUP. Bromum, — ^Bromine [Br]. — Besides its use as an escharotic, bromine in aqueous solution (soluble in 90 parts) is a good general disinfectant, but its irritating vapor precludes its use about the mouth or air passages. Chlorine [CI]. — (For internal doses, see Index of Drugs.) Pure chlorine in gaseous form is too irritating and poisonous to be employed except to disinfect rooms. One part in 100 of the atmosphere, with moisture present, is an efficient germicide for disinfection of dwellings. In either of the official preparations it is available for tooth disinfection or bleachmg. It is also a deodorant by its power of decomposing sulphuretted hydrogen compounds. Its disagreeable odor is an objection to its use as a mouth-wash, but it is a very efficient antiseptic. Even 1 part in 22,000 has been found capable of killing developed bacteria.* The value of chlorine as a water disinfectant has led to the method of "chlorination" upon a large scale in order to insure a safe water supply to cities. In the experience of the city of London it has been found that 1 part of chlorine to 2,000,000 parts of water is efficient, while 1 part in even 3,000,000 has given considerable success. f least 30 per cent, of available chlorine. Incompatibility. — Chlorine gas with a solution of ammonium chloride forms chloride of nitrogen, which is explosive. Chlorine water decomposes potassium iodide in solution, liberating iodine, and mked with a solution of silver nitrate it precipitates chloride of silver. In contact with silver cyanide it liberates hydrocyanic acid. It oxidizes organic substances and destroys vegetable colors. Liquor sodse chlorinatse is decomposed by hydrochloric acid with evolution of chlorine gas and carbon dioxide. lodum. — Iodine [I]. — This substance ranks with the other halogens as a powerful antiseptic. The tincture can be added to water to secure any desired strength, a weak solution being suitable as an irrigation to pus cavities. As an inhalant in pulroonary diseases, when a powerful antiseptic vapor is needed, the tincture may be vaporized with steam in a strength not to exceed 10 minims (0.6 gm.) to a pint of boiling water, usually combined with carbolic acid, eucalyptol or similar drugs. In its uses it has been considered under Irritants. lodoformum. — Iodoform [CIII3]. — Obtained by the action of iodine upon alcohol in the presence of an alkali, it is in form of a lemon-yellow crystalline powder, with a xexy penetrating odor resembling that of iodine. It is practically insoluble in water, soluble in 60 parts of alcohol and in 7.5 parts of ether. It contains 96.7 per cent, of iodine, to which its antiseptic power has been supposed to be due. However, Heile* found that the value of iodoform does not depend upon nascent iodine, but upon a much more active substance, diiodacetylidin, which is set free from iodoform in contact with organic substances when air is excluded Iodoform differs from iodine in being non-irritant. As an antiseptic dressing it is applied in powder, or upon gauze, to wounds and ulcers. Its disagreeable odor precludes its use in dentistry; but a number of odorless or less unpleasant substitutes have been introduced, examples of which are here named, the first only being official. They are all nearly insoluble in water. Losophane, containing 78 per cent, of iodine. Sozoiodol (Sozoiodolic acid), containing 54 per cent, of iodine, 20 per cent, carbolic acid, and 7 per cent, sulphur. This substance has acid combining properties and forms a number of salts. Sodium sozoiodolate is preferred on account of its ready solubility in water and' in glycerin. Acetanilidum [CsHgNO]. — ^Acetanilid, a white crystalline substance, obtained by the interaction of glacial acetic acid and aniline, is employed in very fine powder, as an antiseptic, by being dusted upon wounds MISCELLANEOUS ANTISEPTICS. Among the following agents will be found none of the ready-made proprietary solutions or mixtures that are advertised so largely as antiseptics. Such are entitled to no place in a book that aims to treat subjects in a scientific way, for the basis of their exploitation is commercial, and their use should be regarded as unethical. But, aside from these considerations, there is evidence that they are inferior to some of our well-known simple agents. The only reason for a reference to such preparations here is in order to discourage their use, and this can be done upon the ground of their inefficiency, as shown below. In a very important series of observations in the field of mouth disinfection, Wadsworth,* working in connection with the Health Department of New York City, presents a comparison of the antiseptic power of several of the most popular of the proprietary solutions with that of alcohol. His observations were made with the pneumococcus, which is so frequently found in the mouth. He found that this bacterium can be readily destroyed in a broth culture, but that in sputum its destruction by harmless solutions is extremely difficult, for the reason that, with many antiseptics, diffusion into sputum or into an exudate is hindered by the albuminous matter. Alcohol proved to be very dift'usive and this property was greatly aided by the addition* of glycerin. The observer's conclusions include the following statement: "Of all the commercial solutions studied — listerine, borine, borolyptol, glycothymoline, odol and Seller's solution — none proved efficient when tested on pneumococci under the conditions most favorable for their action. Formalin, lysol and hydrogen peroxide failed to act upon the pneumococci in exudates. In short, alcohol alone, of all antiseptics studied, proved efficient when tested on the pneumococci inidcr all the conditions of the experiments." Alcohol was used in the strength of 20 to 40 per cent. Preference is given to a mixture of water, glycerin and 30 per cent, of alcohol, as being readily dift'usible, efficient and harmless. Betanaphthol. — Naphthol [C10H7OH]. — A phenol occurring in coal-tar but usually prepared from naphthalin. It occurs in colorless or buffcolored crystals, having slight odor and sharp taste, soluble in 1000 parts of water and in 0.8 part of alcohol; soluble also in glycerin and in olive oil. It is neutral. Average dose, gr. 4 (0.25 gm.). Betanaphthol in solution is useful to keep instruments sterile during an operation, as it does not corrode metals. It is applied as an antiseptic to tissues, from the 1 : 1000 saturated aqueous solution, which may be used to irrigate wounds and as a mouth wash freely, to the fullstrength alcoholic solution (1 : 0.8) in the disinfection of root canals. Upon soft tissues, and as a cleansing and disinfecting agent in pyorrhea alveolaris, a 1 : 200 or 1 : 300 solution may be used, prepared either with alcohol or hot water, for it is soluble in 75 parts of boiling water. A saturated solution in hot water, allowed to cool to the desired point, is very useful; while some of the drug precipitates with cooling, the solution will be saturated at whatever temperature used. will produce a white turbidity. ResorcinoL — Resorcin [C6II6O2]. — ^A phenol from various sources. It occurs in colorless or pinkish crystals, having a sweetish taste, soluble in 0.9 part of either water or alcohol, also soluble in glycerin or ether. It is neutral or slightly acid. Average dose, gr. 2 (0.125 gm.). This drug is useful as a mouth antiseptic, a 2 per cent, solution in water being a proper strength for mouth wash or gargle. It is frequently employed in whooping-cough to cleanse the throat and posterior nares by instilling the 2 per cent, solution directly into the nostrils several times daily. Although similar to phenol in action and uses, it is not corrosive and is less dangerous. The internal dose being double that of phenol, it can be used in stronger solution (2 to 5 per cent.) for general antiseptic purposes. chlorinated lime, ferric chloride or bromine water. Potassii Chloras. — Chlorate of Potassium [KCIO3]. — It occurs in colorless crystals or white powder, odorless, and having a salty taste. It is neutral, soluble in 11.5 parts of water, soluble also in glycerin, but almost insoluble in alcohol. Average dose, gr. 4 (0.25 gm.). The U. S. P. advises caution with this salt, as explosion may occur when it is mixed with organic matter (tannic acid, sugar, etc.), or with sulphur, sulphides, hypophosphites or other easily oxidizable substances. the development of bacteria. In mercurial or other forms of stomatitis it is used in saturated solution as a mouth-wash, or in tablet form it is allowed to dissolve slowly in the mouth. It is also valued highly by some as an internal remedy in aphthous stomatitis. It has become a popular remedy in sore-throat, undeservedly so, and is bought and used too freely. Great care must be exercised in the internal use of this drug and its indiscriminate sale should be discouraged, because of its poisonous effects in the blood. It can change hemoglobin into methemoglobin, and in large doses it may also irritate the kidneys.* On the whole, it must be said that the usefulness of potassium chlorate has been overrated and its dangers not sufficiently recognized. Incompatibility.- — Besides the dangers mentioned above, the drug is incompatible with strong snlphvric and hydrochloric ocids. (A drop of sidyhuric acid will ignite a mixture of equal parts of potassium chlorate and sugar.) An aqueous solution mixed with silver nitrate will precipitate silver chloride. Potassii Permanganas. — Permanganate of Potassium [KMnOJ. — It occurs in dark purple crystals, having a characteristic, unpleasant taste: neutral; soluble in 13.5 parts of water. Its aqueous solution is rose-colored when dilute and deep purple when concentrated. It decomposes in contact with alcohol. Being a powerful oxidizing agent the U. S. P. directs that it should be kept in glass-stoppered bottles, protected from light, and should not be brought in contact with organic or readily oxidizable substances. Average dose, gr. 1 (0.06' gm.). Its oxidizing power makes it a valuable disinfectant and deodorant. Applied to the mucous membrane of the mouth in proper dilution it is non-irritant, but it produces a dirty brown stain, which is an objection to its use. However, the stain is easily removed from accessible surfaces by a solution of oxalic acid. It may be applied locally in any strength up to, or even above, 5 per cent. Its action is quite superficial and is to be explained by the fact of the liberation of oxygen, which unites with the albumin of the tissues. Very strong solutions, therefore, may be irritating and even somewhat caustic to mucous * As examples of fatal poisoning by potassium chlorate note the following: (1) A woman, aged seventy years, took 1 ounce by mistake for Epsom salt. Four hours later she fainted, became cyanosed and died fifteen hours after taking. (2) An infant of three weeks died in three days from about 1 gm. (gr. 15), which had been dusted into its mouth. Of 89 cases recorded, 76 were fatal. Witthaus and Becker, Med. Jurisprudence, 1896, vol. iv. membranes. It has been found efficient, and has been extensively used by surgeons, as a hand disinfectant in preparation for operating. After preliminary scrubbing of the hands and nails with soap and water, they are immersed in a saturated aqueous solution of the permanganate. This is followed by a solution of oxalic acid which removes the stain of the permanganate. When used as a mouth wash, 1 : 1000 is a proper dilution. Its use within a carious cavity is always to be avoided; other agents are just as efficient, without the objectionable staining quality. As an application to the throat in diphtheria or tonsillar infection, and to foul ulcers, it possesses considerable value. In 1 per cent, solution it has been found to destroy developed bacteria and in 1 : 1000 it prevents their development.* It is an efficient chemical antidote to morphine if given while the latter is still in the stomach, and, since morphine is partly eliminated into the stomach, in prolonged cases of poisoning the stomach may be washed out at hourly intervals with a weak solution (1 : 2000). Incompatibility. — ^With organic substances, or triturated with sulphur or other inflammable substances, explosion may occur. For this reason it should not be mixed in a closed vessel with syrup or glycerin. With carbolic acid oxidation occurs. Alcohol, oxalic acid or solution of hydrogen dioxide will decompose it. This drug should be used alone in a simple aqueous solution. Sodii Thiosulphas. — Thiosulphate of Sodium. — H yposidphite of Sodium [Na2S203 + 5H2O]. — This salt is soluble in 0.5 part of water and the solution is neutral; insoluble in alcohol. Its antiseptic powder makes it a useful mouth wash. It is also a useful internal antiseptic. Average dose, gr. 15 (1 gm.). Zinci Chloridum. — Chloride of Zinc. — (For general properties, see under Escharotics.) This substance, on account of its germicidal and penetrating power, must be ranked among our best antiseptics. The disadvantages in its use are the irritation it causes and its coagulant action. For tooth disinfection, especially in pulpless teeth, these disadvantages do not obtain, and strong solutions (above 20 per cent.) may be used; while for mouth disinfection a 1 per cejit. solution may be employed. It must be remembered that its coagulation of albuminous matter liberates hydrochlorrc acid, which should not remain Argenti Nitras. — Nitrate of Silver [AgNOs]. — (For solubility and properties, see under Escharotics.) Although generally inadmissible as a mouth or tooth antiseptic because of its staining quality, this drug is valuable in severe local infections of the mucous membrane. It is destructive to the gonococcus wherever found, and in that severe form of conjunctivitis known as ophthalmia neonatorum, which is usually a gonorrheal infection of the eyes occurring during birth, nitrate of silver is most relied upon as the germicide. Also, in order to prevent this serious malady, the advice of C'rede* should be supported and followed, which is, that the eyes of all babes born in charitable institutions should invariably have a 2 per cent.f solution of silver nitrate instilled into them immediately after birth, so as to disinfect every part of the conjunctival membrane. As evidence of the efficacy of such preventive treatment, it may be noted that the statistics of large lyingin institutions where it has been employed, show that the Crede method has reduced the disease to less than one-fifteenth of its former prevalence in the same institutions. Whenever nitrate of silver is locally applied, any excess may be completely neutralized by a solution of sodium chloride. Stains of sih-er nitrate may be removed by a solution of potassium cyanide (not applicable within the mouth as the cyanide is very poisonous), or by moistening with a solution of iodine followed by sodium thiosulphate. Certain other preparations of silver have been foimd to be highly antiseptic and have come into use in general surgery. Of these the most remarkable is an allotropic form of metallic silver that is solnhle in water and in albuminous fluids. The aqueous solution of this (usually 1 per cent.) may be injected into infected tissues, and has * The justification for tliis advice is found in the large percentage of cases of blindness that are due to this severe inflammation, occurring as a result of infection of the eyes at birth. In 1897 an investigation of the causes of blindness of the 306 inmates of the schools for the blind in New York State showed that 21 per cent, of cases were due to ophthalmia neonatorum. Howe, Transactions of the Medical Society of the State of New York, 1897. even been used intravenously in cases of septicemia. It is also used in form of ointment rubbed into the skin. The following non-ofBcial preparations are also now employed in general surgery: Silver Lactate. — Actol [AgCsHaOs + H2O].— This occurs in colorless crystals, easily affected by light, soluble in 15 parts of water. An aqueous solution of 1 : 1000 may be used, as 1 : 300 to 1 : 500 solution is said to be equivalent to 1 : 1000 mercuric chloride solution in disinfectant power.* Silver Citrate. — Itrol [CeHjOvAgs]. — A white powder, soluble in 3800 parts of water, said to be destructive to all ordinary germs when used in a solution of 1 : 4000. The solution should be freshly prepared. It is also used in ointment of 1 to 2 per cent, strength. Protargol {Protein Silver) .—This substance is a silver albumose, containing 8 per cent, of metallic silver. It is a yellowish powder, readily soluble in water, and is less irritating than nitrate of silver. The reason for this probably is that, being an albumin compound, its application to tissues is not followed by the liberation of an acid, as is the case with the nitrate. It destroys various bacteria, and it has, therefore, come to be used much as a substitute for the nitrate in purulent inflammations of mucous membranes, particularly when they are gonorrheal in nature. One to 5 per cent, is the strength of solution in which it is employed. As to germicidal power, Post and Nicoll found a 10 per cent, solution about equivalent to 1 : 5000 solution of silver nitrate, f Argyrol {Silver vitellin). — A proteid salt of silver occurring in black scales, containing 30 per cent, of metallic silver. It is freely soluble in water and the solutions do not readily deteriorate. It does not coagulate albumin nor precipitate chlorides. It is comparatively non-irritating an)d non- toxic, therefore, it may be used freely even in strong solution, e. g., in simple conjunctivitis 5 to 20 per cent, may be applied several times daily and in the gonorrheal form 25 to 50 per cent. As an irrigating fluid 1 : 1000 may be freely used and internally 5 to 10 grains may be given. Its antiseptic power is small as compared with silver nitrate. Post and Xicoll found a 50 per cent, solution inferior to a 1 : 10,000 solution of silver nitrate in germicidal power. \| Stains of argjTol may be removed by a 1 : 500 solution of mercuric chloride. Preparations of silver have been used internally, especially the nitrate and oxide, for alterative effect. It must be noted that the prolonged internal use of this metal should be discouraged. It is capable of producing a permanent staining of tissues, which is outwardty shown by a slight blueness of the skui. This condition is known as argyria and is due to the deposit of silver in the papillary layer of the skin. The same condition may be produced in a smaller area by the local use of silver preparations, where they are allowed to enter the tissues. Hydrargyri Chloridum Corrosivum. — Mercuric Chloride. — Bichloride of Mercury, — Corrosive Sublimate. — Perchloride of Mercury [HgCy. — Average dose, gr. ^ (0.003 gm.) This substance occurs in colorless, odorless crystals, having a disagreeable metallic taste, soluble in 13.5 parts of Avater, in 3.8 parts of alcohol, and in about 12 parts of glycerin. It is acid in reaction, although the addition of chloride of sodium to its aqueous solution will render it neutral. Because of its corrosive properties, for general antiseptic purposes it is used only in dilute solution of 1 : 2000 to 1 : 10,000. However, for limited use as a powerful disinfectant, it may be used as strong as 1 : 1000 or even 1 : 500 in the mouth, as in plantation cases. This drug may cause poisoning in two ways, either as a corrosive by local destruction of tissues, or, after absorption, as a systemic poison. In the former case a strong solution or the pure salt is necessary to cause poisoning, while in the latter case small doses continued, or careless use of ordinary solutions or of any preparation of mercury, is likely to cause systemic mercurial poisoning, with the production of salivation. For example, a single cathartic dose of calomel, or the daily use of the compound cathartic pills, which contain 1 grain of calomel each, has caused salivation. This powerful drug will seldom be the antiseptic of first choice in dental practice. Its unpleasant, metallic taste prevents its use as a mouth-wash. As a tooth disinfectant it is seldom used because of the danger of staining the tooth through the formation of sulphide of mercury.* It corrodes instruments, therefore cannot be used to sterilize them, although glassware may be easily sterilized by the solution of 1 : 1000. In spite of all disadvantages mercuric chloride remains as one of the most efficient germicides. In general medicine and surgery the weaker solutions (1 : 3000 to 1 : 10,000) are u.sed cautiously and for a short time, to irrigate wounds and abscess cavities, to disinfect ulcers, and as douches mto the several passages of the body. Whenever used, a free escape of the solution must be insured, and its use in these ways should rather be regarded as a temporary necessity, to be supplanted by safer agents. As a rule, it should not be combined with other substances. Incompatihility. — Mercuric chloride mixed with livie-water, ammonia or carbonates of the alkalies, will produce a precipitate. With a solution of soap a precipitate of mercurial soap occurs. With potassium iodide red iodide of mercury is formed. Hydrogen sulphide causes a black precipitate of mercuric sulphide. With siher nitrate a deposit of chloride of silver occurs. Metals are tarnished by it, amalgamation occurring with silver and some others. Albumin is coagulated by it. Acute Poisoning. — The symptoms of acute poisoning by this drug are those produced by any corrosive irritant — i. e., pain in the stomach, with vomiting and prostration. The chemical antidote is albumin. (See Table of Poisons and Antidotes.) Systemic Poisoning or Mercurialism. — Only the soluble salts of mercury are capable of causing local irritation, but any preparation of this metal may cause mercmialism. The symptoms of this condition may come on without any gastric disturbance; in fact, it is fortunate that the first indications of systemic saturation occur in the mouth, where they are at once noticed and easily recognized; and the dentist should be familiar with the early symptoms of this, possibly disastrous, toxic disturbance. The first symptom will be hyperemia of the more vascular structures, the pericementum and gums, causing in the former slight tenderness upon forcible closure of the jaws, and in the latter redness. If the condition progresses, the soreness of the teeth becomes decided and an increased flow of saliva occurs, with decided fetor of the breath. This gives the picture of salivation in a positive degree; fortunately the superlative degree, with ulceration and loss of teeth, is almost never seen today because of smaller quantities of the drug now given, with the decline of the antiphlogistic methods of treatment which were formerly in vogue. The elimination of mercury in the saliva, from a system saturated with it, is probably responsible for the occurrence of the ulcerative stomatitis seen in severe cases. Right here let it be stated that detection by the dentist of the early symptoms of mercurialism should call forth no reflection upon the physician who prescribed mercury. This for two reasons: (1) The condition may have occurred accidentally through idiosyncrasy — i. e., a special susceptibility of the patient to the action of the drug, which is sometimes seen; or, the patient may have exceeded directions and used the medicine carelessly. (2) The condition may be intentional, for, in the treatment of syphilis, the use of mercury in some form is often pushed to saturation for a time. Treatment of Mercurialisni. — The patient will complain of two symptoms if the condition is well developed: (1) soreness of the teeth, and (2) the constant flow of saliva which may interfere with sleeping. These will need to be relieved. Relief of the pericementitis and stomatitis must be brought about by elimination through other channels than the salivary and oral glands. The bowel being the most natural route for the elimination of mercury, saline cathartics, freely given, by then power of withdrawmg serum from the blood, will serve our purpose best. The salivation may be controlled by belladonna or its alkaloid, atropine. Of the tinctm-e give 5 minims (0.3 gm.), or of atropme gr. ^0 0 (0.0006 gm.) two or three times daily. This is the best drug for this purpose, as it checks the salivary secretion very decidedly and is not disturbing to the system if used properly. Opium, or morphine, also causes dryness of the mouth, but the systemic effects are unpleasant; and on the whole they are inferior to belladonna. A mouth wash of solution of potassium chlorate (2 to 4 per cent.) is often used in addition. Reports have also been made of the very successful use of hydrogen dioxide in this condition. One part of the official solution to 3 of water, as a mouth wash every half hour, is recommended. Its peculiar detergent property makes it particularly applicable to severe cases, where ordinary antiseptics are less useful. \Yith improvement in the condition, the saline cathartics should still be continued until the drug is believed to have been thoroughly eliminated. Potassium iodide has long been used to aid elimination of this as of other heavy metals. The dose is 10 to 30 grains (0.6-2 gm.) three times daily. It is believed to form the more soluble iodide, which then passes out through the kidneys. Carbo Animalis Purificatus.^ — Purified Animal Charcoal. — Boneblack (not official). — The purification consists in decalcifying by boiling for hours in hydrochloric acid diluted with water. It is employed as an antidote to organic poisons. appreciated. Wood charcoal, prepared from soft wood because more porous, is least powerful of the group, but it has the power of absorbing gases to a large extent — e. g., it is said to be capable of absorbing ninety times its own volume of ammonia gas. It destroys foul gases by absorbing and condensing them within its pores. This power may be increased by platinizing the charcoal. In order to be an efficient deodorant, wood charcoal must either be fresh, or have been recently heated so as to destroy organic impurities that may have been taken up through exposure to the air. Animal charcoal is a more powerful absorbent, being capable of extracting coloring matters from organic solutions. It may be used in decolorizing galenical preparations of drugs. Purified animal charcoal is too powerful to use in decolorizing solutions of drugs, for it is capable of extracting organic principles, such as tannin, alkaloids and resins,* whereby the strength of the product would be lessened. Because of this behavior toward organic principles, purified animal charcoal has a distinct V'alue as an antidote to alkaloids and other organic poisons. the atmosphere. Dental Uses. — About the only use to which charcoal could be properly put is to cleanse a foul mouth, such as is too often met with among ignorant people. Its practical application is questionable. It is not a proper ingredient of tooth powders, because of the sharpness of its particles. Hydrogen Dioxide. — This compound, having the chemical formula of H2O2, is used in several strengths as an antiseptic. Its value depends upon the extra oxygen which it contains and which it gives up readily when brought into conditions that favor its decomposition. It is, therefore, an oxidizing agent, the oxygen liberated in nascent condition giving it three distinct properties w^hich make it especially valuable in dental practice, it being a disinfectant, a detergent and a bleaching agent. hydrogen dioxide in water keeps its strength and quaUties for months at ordinary temperatures. Higher strength sohitions require the addition of considerable acid or other preservative, and must be looked upon as unstable and dangerous to handje. A 25 per cent, ethereal solution is put up in closed glass tubes with certain precautions noted upon the label. In this strength the agent is a decided caustic and must be handled with care, its chief use being as a bleaching agent. The official solution is called : Liquor Hydrogenii Dioxidii — Solution of Hydrogen Dioxide [H2O2]. This is a colorless liquid, slightly acid in reaction, and it contains when freshly prepared, not less than 3 per cent., by weight, of the pure dioxide. It is also known as the "ten volume" solution, as it yields upon decomposition about ten times its own volume of oxygen. The acid it contains is necessary to its preservation. Average dose, f51 (4 mils.). The most characteristic property of this liquid is its foamy decomposition in contact wdth organic matter, by the activity of which its strength can be roughly estimated. It gradually loses strength by keeping, though it is stated that deterioration will be retarded if the stopper of the bottle be coated with paraffin, or if a stopper of cotton be employed instead of an ordinary cork stopper. It should be kept in a cool place. It decomposes when heated or exposed to sunlight, also when in contact with charcoal, oxides of manganese, potassium permanganate, alkalies, blood, pus and other loosely organized matter, besides many other chemical substances. Mixed with a solution of potassium iodide it liberates iodine. As a rule, it should be used alone, so as to avoid unexpected decomposition. When the 3 per cent, solution is applied to the tissues it decomposes with some energy, because of the rapidity and abundance of the liberation of oxygen. Upon a tender mucous membrane the action may be so irritating as to require dilution of the liquid. The oxygen in nascent condition is a powerful germicide and disinfectant, cleansing the surface of the tissue thoroughly without injury, for it does Jiot coagulate, nor constringe, nor penetrate. Its action is solely that of an oxidizing agent, and any irritation from it corresponds to the energy of oxygen liberation. As a gargle or mouth wash it may be employed in full strength of the official solution (3 per cent.) or diluted. With children it is usually diluted to one-half or one-quarter strength. injure healthy tissues. Its special value lies in its power to oxidize, disintegrate and destroy disorganized tissue, such as pus; and in disinfecting abscess cavities it has the further advantage of distending the cavity by the expansion resulting from the liberation of oxygen, so that every portion of the cavity and its walls are reached by the oxygen. Distention of an abscess cavity in this way will cause momentary pain, but scarcely more than attends the use of a coagulating or penetrating antiseptic. In tooth and root-canal disinfection the dioxide is used freely. In removing pus and cleansing the pockets in pyorrhea, in the cleansing of ulcers and, in fact, in any local infectious condition, hydrogen dioxide is an ideal disinfectant. But the mistake should not be made of expecting of this substance properties that it does not possess. It is not antacid, it is not coagulant, it is not astringent, it does not affect healthy tissue. Its action is upon disorganized tissue, blood, pus and bacteria. The one indication for its use is the presence of infection . One exception must be made under the general statements as to its use in abscess cavities; it should not be used in the antrum with its unyielding bony wall, unless a very free opening has been made. Very severe pain might easily attend its use ordinarily in empyema of the antrum, on account of pressure from the rapid expansion of the liberated oxygen. Systemic effects never occur from the proper use of hydrogen dioxide; therefore, it is non-toxic. However, by its hypodermic use some of the unchanged dioxide may be absorbed into the circulation and cause disorganization of blood elements with the production of emboli. An animal may easily be killed by intravenous injection of dioxide of hydrogen. As a bleaching agent this substance is discussed elsewhere. Quininae Sulphas. — Quinine Sulphate [(C2oH2402N2)2.H2S04 + 7H2O]. Quinine, the chief alkaloid of cinchona bark, is used in the form of various salts, but mostly as the sulphate. This occurs in white, silky crystals or as hard, prismatic needles; soluble in 725 parts of water, 107 parts of alcohol and in 30 parts of glycerin. [Acids aid the solubility of quinine and of the sulphate. The bisulphate and several other salts are much more soluble than the sulphate.] Average dose, tonic, gr. 1\| (0.1 gm.) three times daily; anti-malarial, at least gr. 15 (1 gm.) daily. While this drug is classed as antipyretic and anti-malarial, the latter action is most important and is really antiseptic. It is the most typical internal general antiseptic in use. Not only is its action in the digestive tract destructive of some of the intestinal infections, such as amebic dysentery, but, in the blood of malarial subjects it readily destroys the Plasmodium malaria, which is the specific organism of malarial or intermittent fever. In order to be absorbed into the blood in sufficient strength to accomplish this it must be given in large doses daily for a week or more; but even thus it is comparatively harmless to the system, the only unpleasant effects being ringing in the ears and slight temporary deafness. The term cinchonisni is applied to these symptoms of the full action of quinine. The former use of quinine in large doses, to combat inflammation (antiphlogistic), is now nearly obsolete. Chinosol. — Quinosol [C9H6X.KSO4 + H2O] (not official). — Chemically this drug is oxy-quinoline-potassium-sulphate, occurring in yellow crj^stals having an astringent, aromatic taste and readily soluble in water, but insoluble in alcohol. It is not a coagulant, therefore not destructive to tissue. It may be used in a 1 : 1000 aqueous solution as a general antiseptic wash, but for local uses, such as application to abscess cavities, empyema of the antrum, etc., 1 to 2 per cent, solutions may be used. Incoinpatihility. — With lead acetate or mercuric chloride precipitates .will occur, while the addition oi ferric chloride will produce a bluishgreen color. Steel instruments are tarnished but not corroded by the drug. Formaldehyde [CH2O]. — This valuable addition to our materia medica is a gas, usually obtained by the partial oxidation of methyl alcohol. It is one of the most powerful disinfectants known, ranking almost with corrosi\'e sublimate. It fills a place that no other agent does as a really eft'ective and practicable disinfectant gas. It is far superior to sulphurous acid gas in respect to efficiency, penetrating power and non-action upon metallic furnishings. A'arious lamps and other apparatus for generating the gas for extensive use have been devised, and small fumigators or candles for limited use, as in the disinfection of books, instruments and clothing in a small air space. The gas is very irritating to the eyes and to the air i)assages. As a medicinal agent formaldehyde is employed in its official aqueous solution, as below. Liquor Formaldehydi. — Solution of Formaldehyde. — Formalin. — This is an aqueous solution containing not less than 'A7 per cent, of formaldehyde gas. It has a pungent odor and caustic taste, being irritant to tissues. It is the commercial form of the drug and is miscible with water and with alcohol in any proportion. It should be neutral or only faintly acid in reaction. ri)on standing it may become cloudy from the separation of paraformaldehyde. A stronger sohition is unstable. A much weaker solution must be used for application to living tissues, for this substance is characterized by its penetrating quaUiy and irritant action. While this di'ug has the power to harden tissues to a marked degree, the action is not a coagulation in the ordinary sense. When applied to a mucous membrane, it does not coagulate appreciably. In contact with egg albumin it coagulates the latter only slightly. In fact, it seems to hinder the coagulation of albuminous liquids to which it has been added; for egg albumin and serum are not precipitated by heat, nor is casein coagulated by the rennet enzyme, after being thus treated.* Compared with carbolic acid, the local action of formalin is less corrosive and more penetrating; it is on the whole more irritating, except for the momentary pain caused by the former. The result of its action is a deeper hardening of the tissues to which it is applied. Because of the continued irritation which it occasions, it cannot be used extensively as a general antiseptic to the soft tissues, except in very dilute solution. Even for disinfection of the hands, it has been largely discarded as being too irritating for daily use. As a mouth-wash, 0.5 per cent, of formalin should never be exceeded. For disinfection of pulpless teeth 5 per cent. may be used, but many have discarded it as being undesirable in any gfiicient strength, and liable to work injury beyond the apical foramen. On the whole, it must be said that formalin is not gaining favor as a general antiseptic for application to the tissues of the body. The experiments of Hunt and Jackson f rate the 1 : 200 solution of formalin as far inferior to the same strength of benzoic acid and to 1 : 2500 solution of mercuric chloride, for mouth disinfection. Harrington found that a 1 per cent, solution of formaldehyde failed to kill the Staphylococcus pyogenes aureus in sixty minutes, while a 2 per cent, solution required forty-five minutes, and a 5 per cent, solution twenty minutes to destroy the same organism. J As an agent to prevent the growth of mouth bacteria. Peck found pure formaldehyde in 1 : 1000 solution hardly one-fourth as potent as the same strength of bichloride of mercury solution. § In his experiments formalin proved to be a dangerous escharotic when kept in contact with soft tissues. of solution of formaldehyde and cresol. An important use of formaldehyde is in the hardening and preservation of anatomic and pathological specimens. A 5 per cent, solution of formalin is commonly employed. The advantages of this agent over alcohol is that the color of the specimen is better retained, and the tissue does not shrink to any great degree. Paraformaldehydum. — Paraform. — Average dose gr. S (0.5 gm.) . This polymeric form of formaldehyde occurs in white masses or powder, slowly soluble in cold water, more readily in hot water, insoluble in alcohol. It has a slight odor of formaldehyde, which, given off slightly at ordinary temperature, is evolved rapidly when heat is applied. This points to its extensive use, in the form of "formaldehyde candles," in disinfecting rooms and clothing. Dissolve the guttapercha in the chloroform. Dissolve the thymol in the eucalyptol, add the paraform, finely powdered, and shake well. Mix the two solutions, and keep the bottle open in a warm place until the chloroform has evaporated. (Prinz.) Hexamethylenamina. — Urotropin [C6H12N4]. — This substance is a chemical compound of formaldehyde and ammonia. It occurs in colorless crystals or white powder, soluble in 1.5 parts of water and in 12.5 parts of alcohol. Average dose, gr. 4 (0.25 gm.). The aqueous solution is alkaline. The chief value of urotropin is as an antiseptic to the urinary tract. The explanation of its action is, that when eliminated by the kidneys it is decomposed into formaldeh}'de and ammonia, the former acting then as an antiseptic. It is a very efficient agent, but the urine must be acid, in order to secure a reliable effect, and quite large doses, even up to gr. 20 (1.30 gm.), are often employed. BLEACHING AGENTS. The art of removing discolorations of the teeth has for years engaged some of the best thought of the dental profession, with the result that today we may say that the bleaching of teeth has become a science. With causes of discoloration well known and properly classified^ the chemical reactions necessary to discharge the color may usually be secured with certainty. Moreover, the appreciation on the part of the patient is usually commensurate with the effort expended. The excellent chapter on "Discolored Teeth and their Treatment," by Dr. Ku"k, in the American Text-hook of Operative Dentistry, gives a systematic presentation of present-day knowledge of methods of bleaching discolored teeth, which must stand as the authority of today upon this special subject. The province of the chapter here presented is to deal with substances rather than detailed methods of their application. The chief agents employed to bleach teeth are discussed, therefore, as to their properties, action and, in general, their uses. There must necessarily be a chemical basis for the action of these agents, for it is inconceivable that colors could be discharged by the action of such strong chemicals as chlorine and nascent oxygen without the occurrence of chemical reactions. are conveniently grouped into (a) Agents that furnish free chlorine, or indirect oxidizers. (6) Agents that furnish nascent oxygen, or oxidizing agents, (c) Agents that have an affinity for oxygen, or reducing agents. For the removal of metallic stains, additional agents, chiefly in the nature of solvents, are required. While the use of chlorine to secure a change of the metallic deposit to a chloride, followed by thorough washing with warm distilled water, is held to be the general rule of treatment, its final success may depend upon the solubility of the chloride. Chlorides are commonly soluble in water, but silver chloride is an exception, it being entirely insoluble. Hence, in removing silver stains the chlorine treatment is followed by a saturated solution of sodium thiosulphate (hyposulphite), which is a sol\-ent for chloride of silver. In removing stains of manganese the final washing must be with a solution containing oxalic acid. In case of mercurial stain, Kirk advises the use of an aqueous ammoniacal solution of hydrogen dioxide after the chlorine treatment. Chlorine. — The value of chlorine gas as a bleacher depends largely upon its affinity for hydrogen, by which it may either directly break up the color molecule or liberate oxygen from the water molecule. In the former case it is a direct decolorizer, and in the latter it is indirectly an oxidizer. The gas is now seldom applied directly to the tooth, although the Wright method employed it this way with good results, but the complicated apparatus needed prevented its general adoption. At the present time it is applied either in solution or in a loosely combined preparation which yields it up readily. chlorine. Calx Chlorinata. — Chlorinated Lime. — This is a whitish powder containing at least 30 per cent, of available chlorine. The powder deteriorates upon exposure to the air, becoming moist and losing its strong odor of chlorine. If kept in metal containers it is unfit for bleaching teeth, because of the liability of metallic contamination. It is preferably kept in paraffined card- board packages or in bottles. To be fit for use it must be dry and should exhale a strong odor of chlorine. When either chlorinated lime or Labarraque's solution of chlorinated soda is employed, it is, after being placed in the tooth, treated with any dilute acid, usually 50 per cent, of either acetic acid or tartaric acid, in order to free the chlorine more rapidly. The use of chlorinated lime in this way constituted the original Truman method of bleaching teeth. Hydrogen Dioxide. — This substance and its properties are discussed fully in the chapter on Antiseptics. While the official 3 per cent, solution possesses some degree of bleaching power, its use has been largely superseded by that of the "caustic pyrozone" or 25 per cent, ethereal solution. Its value depends upon the nascent oxygen which it liberates. Kirk* states that "more rapid and permanent effects are produced when the pyrozone solution is rendered alkaline," which may be done by the addition of a little of one of the solutions of the pure alkalies, either aqua ammonise fortior or solution of potassium or sodium hydroxide. Special care must be taken in handling and using the 25 per cent, solution, on account of its caustic action upon the fingers, which may be prevented by first oiling them. Sodium Dioxide. — Sodiu:h PsROxroE [Xa202] (not official). — ^This occurs as a yellowish-white powder that absorbs water readily when exposed to the air, with deterioration of its activity. It is caustic, soluble in water, and strongly alkaline. Its value as a bleacher is threefold : Thus it not only acts as an oxidizer, but as a detergent. It is applied in saturated aqueous solution, which must be prepared at a low temperature in order to avoid loss of strength. If weaker solutions are desired in some cases, they may be prepared from the saturated solution by diluting carefully with water. Benzoyl-acetyl Peroxide. — Acetozone. — Bemozone [CeHsCOOOCOCHs] (not official). — In a comparative experimental study of bleachers f Dr. Hoff has obtained results that would seem to place this new agent next to hydrogen dioxide and sodium dioxide. He describes it as an organic peroxide, whose decomposition products are not destructive to the tooth structure. It acts slowly, and it may be allowed to remain for some time within the cavity. equal parts of the pure crystal and an inert powder, which makes a cloudy solution in water. The solubility of the crystals in water varies from 1 : 1000 to 1 : 10,000. It is slightly soluble in alcohol and in ether. Nearly all solvents, including water and alcohol, decompose it gradually. It should be kept in small, well-stoppered bottles in a cool place, securely protected from moisture, and from contact with organic matter, alkalies, alcohol and other solvents. toxic germicide. Potassium Permanganate parts readily with its oxygen when brought into contact with organic matter. Its disadvantage as a bleaching agent is, that the resulting compounds are dark-colored and require to be treated with a solution of oxalic acid in order to complete the decolorization. taining not less than 6 per cent., by weight, of sulphur dioxide gas. Both are bleaching agents by reason of their affinity for oxygen. However, they do not destroy organic pigments, as the color may be largely restored by an alkali or a stronger acid, according to Witthaus. The dioxide (SO2) possesses the stronger affinity, being oxidized in the presence of water to sulphurous acid (SO3H2), and finally to sulphuric acid (SO4H2). The dioxide gas being preferable, Kirk advocates the use of a mixture of 10 parts of sodium sulphite and 7 parts of boric acid which, being packed into a tooth and moistened with water, may be quickly sealed in with a temporary filling. A reaction occurs between the two substances with liberation of sulphur dioxide. The bleaching process by this method is slower than by the use of the peroxides. The solution in water known as sulphurous acid is less efficient than the gas, but still may be employed. It must be remembered that the final product of oxidation of this class of bleachers is sulphuric acid, which must be thoroughly removed or neutralized. REDUCING AGENTS 163 sulphur dioxide. They are of use as sources of sulphur dioxide gas when they are decomposed. In bleaching of teeth the sulphite chiefly is used, as in the process noted above. (See also under Antiseptics.) Sodii Thiosulphas. — Hyposulphite of Sodiuivi [Xa2S203 + 5H2O].— This salt, soluble in 0.5 part of water, is used in saturated solution to remove the silver chloride resulting from previous treatment of silver stains with chlorine. Anesthetics are agents used to abolish sensibility, for the purposes of surgical treatment, the relief of spasm, and the alleviation of severe pain. Complete general anesthesia includes unconsciousness, due to paralysis of the cerebral cortex, and loss of excitability of all centers of reflex action, except those concerned in the functions of respiration and circulation. Local anesthesia means usually the abolition of sensibility to iKtin in a certain locality. It is rather a condition of analgesia, which is defined to be the absence of sensibility to pain, as distinguished from anesthesia, which means the absence of all sensibility. When confronted by the necessity of a surgical operation, a decision must be made first as to the advisability of using an anesthetic, then, as to whether local or general anesthesia shall be employed, and finally the choice of the agent must depend upon the condition of the patient, the length of time required for the operation and the comparative safety of the drugs from which a selection is to be made. In major operations the necessity of general anesthesia appears at once, and the chief point will be the choice of the drug to be used. In minor operations, such as the extraction of a tooth or the lancing of an abscess, we should not resort too readily to general anesthesia. We should rather allow the patient to assume the responsibility of deciding to take an anesthetic. And in case of a prolonged or severe operation in dental practice, the patient's physician should, as a rule, assume the responsibility of deciding what anesthetic shall be used, and also supervise its administration. The use of local analgesics may be more readily resorted to for any minor operation about the mouth. LOCAL ANALGESICS. These agents are employed to paralyze the sensory nerve endings to painful impressions in a limited region. They produce their effects in two ways, and are accordingly classified into: Chloride of ethyl spray. . The value of all of these depends upon the operation of the physical law that a solid in changing to a liquid, or a liquid changing to a vayor requires a certain amount of heat to effect the change. The heat so required is abstracted from the surrounding medium and becomes latent in the new form of the substance, being necessary to the maintenance of that form. When a mixture of ice and salt is applied to tissue, heat is abstracted so rapidly by the melting ice that the part may be frozen superficially. The only use of the salt in the mixture is, by its affinity for water, to make the ice melt more rapidly. It would be impossible to freeze tissue by the application of ice alone, because of the slow abstraction of heat. One danger in the application of ice and salt is freezing too intensely or too extensively, which may induce sloughing of tissue. The more salt there is added to the ice up to a certain point the more rapidly will freezing occur. Therefore, to a given quantity of ice, pounded fine, one-fourth to one-third as much salt should be added. They should be well mixed and applied in such manner that heat may be abstracted only from the part to be operated upon. This mixture, probably the earliest of all local analgesics, must still be accorded a place of usefulness, although it has been largely superseded by the highly volatile liquids whose effects are so easily secured and controlled. It may be used upon an accessible surface, but within the mouth it is certainly inferior to a spray. The liquids used for local analgesic purposes must be very volatile at or below the temperature of the body, so as to evaporate rapidly when sprayed upon the tissues. The following have been employed: only one used at present. Chemically, ethyl chloride [C2H5CI] is an ester resulting from the action of hydrochloric acid gas upon absolute alcohol. It is a colorless liquid, inflammable and extremely volatile, with a specific gravity of 0,918 at 46.4° F, The specific gravity of its vapor is 2.22, It is put up for use in sealed tubes containing \| or 1 fluidounce. By means of a capillary opening through the glass stopper a very minute jet is emitted, which is directed upon the part to be frozen. Thus there is no waste, and the fine stream may be forced a distance of a foot or more, especially if the pressure within the tube be increased by enclosing it in the warm hand. The action of the drug is, therefore, easily controlled and may be secured at any point within the mouth without endangering the tissues. Some pain attends the freezing of tissue by whatever means induced, but this disadvantage is outweighed by the assurance the patient acquires that the pain of the operation will be much lessened. Indeed, for the extraction of a tooth, the mental effect of the harmless chloride of ethyl application may be taken advantage of to nerve a hesitating or nervous person up to a point of ready cooperation. With this agent several teeth may be extracted at one sitting with practically no danger; however, by inhalation the drug has been found to be a quick and powerful general anesthetic, whose safety seems to be less than that of ether; so that, in its local use in the mouth, care should be exercised to avoid the occurrence of general anesthesia. One-half to one fluidrachm (2-4 mils) quickly inhaled may easily cause unconsciousness. The full effect of the local application is shown by blanching of the tissues at the point of evaporation. The action being chiefly upon the gums, the real advantage to be sought is painless application of the forceps. We cannot expect the actual pain of extraction to be entirely removed. TECHNIQUE OF LOCAL ANESTHESIA 167 Its convenience, readiness, safety and comparative efficacy give it a sum of advantages not possessed by any other local analgesic for slight operations. As a general anesthetic it is considered in Chapter XIV. The paralyzant class of local analgesics includes the following drugs, which are here compared as to solubility, their other properties and uses being discussed in regular order. The first three are oflficial. Orthoform, slightly soluble in water, freely in alcohol. These all obtund or paralyze the sensory nerve terminals wherever they are applied, afi^ecting chiefly sensibility to pain. They produce very little effect upon the unbroken skin. Upon mucous membrane, whose texture is less firm, their effect is decided, but their full action is only obtained when they are applied to a denuded surface or injected hypodermically; except, that in the application to the very sensitive mucous membranes of the eye a complete effect is quickly obtained, although no abrasion be present. To attain success in the practice of local anesthesia it is essential that the operator should possess suitable instruments and exercise infinite care in the preparation and use of the solution selected. sterilization by boiling. Such syringes may be of the all-metal type or the barrel may be of glass. The needles should be selected with due regard to the accessibility of the part to be operated upon. The solution should be freshly prepared for each case. It is convenient to use tablets containing definite amoiuits both of the drug and of s^'nthetic suprarenin. These should })e dissolved in either normal saline* or Ilinger's solution. f A 1 or 2 per cent, solution of the drug is suitable for all dental operations. There are on the market small graduated porcelain dishes with standard and handle, in which the solution may be prepared and, where permissible, boiled over a Bimsen burner or alcohol lamp. The injections about the teeth may be made in any of the following ways according to the requirements of the case: vSnbperiosteal, intraosseous, peridental or submucous. The area to be injected should first be painted with tincture of iodine diluted with an equal cjuantity of grain alcohol. Thorough asepsis should be practised throughout the operation. Chloride and consists of 0.85 per cent, of sodium chloride in distilled water. t Ringer's solution imitates closely the salinity of the blood plasma, containing, in distilled water, sodium chloride, 0.7 per cent.; potassium chloride, 0.03 per cent.; calcium chloride?, 0.025 per cent. depression. The two diagrams presented (Plates II. and III.^ stimulant and depressant effects respectively. Stomach. The local effect is to benumb the sensory nerve endings in the stomach. Nervous System. Brain. Simuilates the cerebral cortex. Medulla. Stimulates respiratory and vasomotor centres. Spinal cord. Stimulates reflex centres. Sensory nerve endings are always depressed when the drug is applied locally. voluntary muscles. Eye. Dilates pupil by stimulating dilator nerves. Circulation. Arterial pressure is increased. Heart. Action accelerated by direct stimulation either of heart muscle or of the accelerator nerves. Capillary area. Contracts arterioles by stimulation of vasomotor centre in the medulla and by direct action upon the vessel walls. Respiration. Rate increased by stimulation of respiratory centre. Elimination. Cocaine has been detected in the urine, but its influence upon the kidneys is variable and uncertain, therefore probably indirect. The poisonous effects of Coca, or the secondaiy effects of a large dose, are depressant, following quite definitely the lines of previous stimulation. when locally applied. For local analgesic purposes the alkaloid Cocaine is employed in from i to 4 per cent, solutions. CONDUCTIVE OR REGIONAL ANESTHESIA. In addition to the simple local use of this group of drugs, their application has been extended to anesthetize a whole extremity or region supplied by a certain nerve. This is accomplished by injection of the drug into and about the nerva at some point in its course. If thoroughly done, painful sensation will be abolished in all the region of distribution of the nerve. While this method may be employed to secure anesthesia for a surgical operation, the same is also advocated to prevent shock from operations upon the extremities.* This method of producing regional anesthesia is coming into wide use by the dental practitioner and possesses many points of merit. But before this method is taken up the dentist should become thoroughly familiar with the technique as well as possess an exact knowledge of the anatomy of the parts. It is also quite necessary that the operator possess the necessary paraphernalia for properly carrying out the exacting technique of this method. Injections should be made at the point where the trunk of the nerve supplying the part may be reached, as in the following locations: zygomatic, infra-orbital, anterior palatine, posterior palatine, pterygomandibular or mental, according to the areas which ar€ to be anesthetized. The student is referred to the more exhaustive treatises on this subject for the minute details of technique. Cocainse Hydrochloridum [C17II21O4XHCI], average dose gr. \ (0.015 gm.). — This agent stands as the typical local analgesic. It is a neutral salt of the alkaloid cocaine, from the leaves of ErytJiroxylon coca, grown chiefly in Peru and Bolivia. ^Yhile the alkaloid was discovered about 1860, and its peculiar analgesic power observed soon after, its introduction to the medical world as a practical local analgesic was due to Karl Roller, who in 1884 reported experiments to the Congress of German Oculists. In a few weeks cocaine was being used all over the world, t Administered internally, the coca leaves and their preparations, as well as the alkaloid, are stimulating to the nervous system in small doses and depressing and poisonous in large doses. (See Plates II and III.j Locally applied to sensory nerves, cocaine is always depressing. Applied to the tongue it removes the sense of taste for bitter substances, diminishes it for sweet and acid substances, while for salt it is not appreciably lessened. When taken into the stomach it diminishes the sensibility of the organ, thereby lessening the sense of hunger, and probably impairs the activity of digestion. The sense of touch may be lessened by it, but the most marked result of its application, and the most desirable, is the removal of the sense of pain. The temperature sense for heat and cold is not diminished. Applied locally into the eye it causes dilatation of the pupil in addition to the analgesic effect. It usually is applied as directly as possible to the terminal endings of the sensory nerve, but will produce the same effect if applied to the nerve trunk anywhere in its course.* It should be noted that cocaine has a deleterious effect upon all kinds of tissue when applied in any but very small quantities; therefore it is classed as a general protoplasmic poison. The reason for the prominence of its effect upon nerve tissue is, that we are here dealing with the tissue that is a medium of sensation and expression, and its impairment is, therefore, more easily appreciated. Being one of the drugs that combines a stimulant (early) effect with a depressant (later) effect, the greatest degree of caution must be exercised to avoid the habitual use of the drug by patients. It is one of the most seductive of the drugs that are taken habitually, and its effects are most disastrous. Particularly is it unwise to order this drug for the patient to use at home, whether as gargle, mouth wash or nasal spray. Observation has shown that the system acquires a tolerance of large doses of cocaine when it is taken habitually, as is the case with morphine, the quantity taken daily in some cases reaching as high as 30 grains. The drug is often taken as a substitute for morphine, or as an antagonist to it. The effects of cocaine taken habitually seem to be more rapidly disastrous than those of morphine. In the practical use of the drug the hydrochloride of cocaine is preferred to the simple alkaloid, because of its greater solubility. Alkaloids, as a rule, are only sparingly soluble in water, hence their salts are commonly employed. Cocaine illustrates this rule, being soluble only in 600 parts of water, while the hydrochloride is soluble in 0.4 part of water. It is also soluble in 2.3 parts of alcohol. * We are indebted to Dr. G. W. Crile for some facts concerning the value of cocaine in blocking nerve trunks to the transmission of sensory impressions from an injured part of the body. By very careful experiments he has come to the conclusion that one prominent factor in surgical shock is the depression of the vasomotor system by exhaustion of the centers. This occurs through their excessive stimulation by sensory impressions coming from the site of injury or operation. In operations upon the extremities, he prevents shock by "nerve-blocking" with cocaine, i. e., by injecting the drug about the nerve trunk so as to abohsh its power of carrying sensory impressions. the tongue. Solutions of cocaine hydrochloride do not keep well beyond a few days, neither can they be sterilized by boiling without impairing their value. The practitioner must either make up his solution when needed, renew it frequently, or else add some antiseptic to preserve it. If it is desired to keep the solution more than a few days a very little phenol (I to 1 per cent.) may be added to prevent the growth of organisms, and in this strength the coagulant action of the latter drug is scarcely noticed. Boric acid likewise is used as a preservative in the proportion of 2h per cent, in the aqueous solution of cocaine. Salicylic acid is also recommended m the strength of 0.1 per cent. 1 : 1000;. Chloretone is used by somie in the strength of i to ^ per cent. Local Action of Cocaine. — The chief interest of the dental surgeon m this drug centers about its use as applied locally to. or injected beneath, the mucous membrane. ^A hen applied to the membrane of the mouth the bitterness of the drug is marked. The pure crystal or a strong solution, .5 to 10 per cent., will cause some anemia of the surface, which is probably due to a constrictor action upon the arterioles, and at the same time sensitiveness of the tissues to pain will be abolished to the depth of penetration by the drug. For surface treatment, or upon so sensitive a mucous membrane as that of the eye, direct application of cocaine in 1 to 4 per cent, solution is sufficient: but for extraction of teeth such application is of no use. The drug must be injected into the tissues about the socket of the tooth. When this is done there occius immediately a blanching of the tissues at the site of injection, which is due partly to forcible distention by the fluid injected, and probably partly to vascular constriction, .^ome pain attends the use of the drug in this way, but it occurs only at the moment of injection, and is quickly succeeded by complete analgesia of the locality. The vasoconstriction is often foUowed by a relaxation that permits liA^peremia of the tissues, which may be more or less painful. This, however, must be regarded as a secondary and later effect, occurring rather after than during the operation. Dosage. — The strength of cocaine solutions employed varies from I to -4 per cent., according to the rapidity and degree of effect desired, the total quantity' used being limited by considerations of safety. The maximumi quantity allowed to gain entrance into the circulation at one time should not exceed one-quarter of a grain. This ought to be the limit in the ordinary nse of the drng by hypodermic injection. However, the free bleeding of the tissues following extraction will remove some of the drug, and may modify our estimate of the quantity that may be safely injected in a given case. A 1 per cent, solution will usually suffice, and of this twenty-five minims contain one-quarter of a grain. When application is made to the surface of the mucous membrane of the mouth, or when the drug is used by cataphoresis, stronger solutions may be required; and when the drug is so applied that absorption occurs only through the unbroken mucous membrane, a larger quantity may be used, but should never exceed one-half of a grain, which is the maximum dose for stomach administration. For direct application to the pulp of a tooth, a small quantity of a stronger solution or a little of the pure crystal may be employed. An excellent rule in the interest of exactness of dose and ease of calculation is given by Burchard.* It is "to make the solution upon the basis of 8 grains of the cocaine salt to 1 ounce of the. menstruum which will give 1 grain in each drachm and ^-^ of a grain in each minim." This solution would be a little less than 2 per cent, in strength. Ten minims would ec^ual \| of a grain, which would be within the safe hypodermic dose for an adult. That this drug is one of the most dangerous of those in daily use is attested by the many cases of cocaine poisoning that are upon record. Among those well authenticated is the case of a girl, eleven years of age, whose death resulted in forty seconds from the hypodermic injection of 12 drops of a 4 per cent, solution, or about \| grain. f In another case death is said to have been caused by the application of 20 drops of a 5 per cent, solution (1 grain) to the gum. J T. H. Burchard reports a case in which 10 drops of a 4 per cent, solution hypodermically caused unconsciousness and apparent death in four minutes; Meyerhausen, a case in which 8 drops of a 2 per cent, solution upon the conjuncti^'a of a girl of twelve years produced ^•iolent symptoms; Stevens, one in which 4 minims of a 3^ per cent, solution caused, in a man, violent convulsions followed by mania; Frost, a case of a child of fourteen in which 1 drop of a 1 per cent, solution in the eye caused marked poisoning. Idiosyncrasy must probably account for Schleich Infiltratian Method. This consists of infiltration of the tissues with a very weak solution of cocaine by a series of contiguous injections, which produce really a local edema. Three different strengths of cocaine, approximately 1 : 500; 1 : 1000 and 1 : 10,000, are employed as the case demands.* To the solution is added 0.2 per cent, of sodium chloride and small quantities of morphine hydrochloride and phenol. The 1 : 1000 is the strength commonly used. Undoubtedly the pressure of distention by the larger bulk of solution injected contributes to the analgesia, for it has been found that forcible distention of tissues by sterile water often sufEces for slight operations. This method has the advantage of permitting a large quantity of solution to be used, and a longer operation to be performed with much less danger of cocaine poisoning. A number of ready-made solutions for local analgesia are upon the market. They are primarily commercial articles, and it is safe to say that cocaine or some substitute forms the basis of their formulas. There is no reason why a qualified practitioner should select a commercial formula instead of making up his own solution, when using so powerful a drug. There is absolutely no guarantee of the composition and uniformity of the proprietary analgesic preparations, even though the names of ingredients are given; while if the practitioner orders by his own formula of official drugs, his pharmacist can guarantee acciu-acy. The advantages claimed for special formulas are: first, that they contain substances that aid the desired action and permit a lessening of the quantity of cocaine used; second, that they contain one or more physiologic antagonists to cocaine, which will counteract any possible toxic action; or, third, that they keep better than a simple solution of cocaine. All of these objects are desirable, but it is better for the dentist himself to intelligently and scientifically select his own aids and antag- onists to the drug. This impHes a knowledge, on his part, of the physiologic action of the various drugs proposed, and the ability to note the indications for the selection of one or another in a given case. And this is not too much to expect of the trained practitioner of today. The cocaine strength of this solution wall be 1 per cent., and each 15 minims will contain I grain, with yYo grain of atropine, and g-^ grain of strychnine. One or two drops of adrenalin solution (1 : 1000) may be added, if desired, to each quantity of injection. The carbolic acid present is for preservation. Even less will suffice to keep the solution for some time. Prinz* suggests that the solution should be made isotonic with the blood, so as to preserve normal cell osmosis, which is doubtless an advantage in the matter of lessening the irritation caused by the solution. He states that to make a 1 per cent, solution of cocaine isotonic requires the addition of 0.8 per cent, of sodium chloride, making the following trate the action of the drug upon the different parts of the system. General Uses.— Cocaine has come to be relied upon for the relief of pain and irritation wherever it can be locally applied. Its local analgesic action renders it of great value in minor surgery, and, properly adapted, it is useful for operations of considerable extent. A t^-pical occasion for its use would be the removal of a foreign body from the eye. Here the instillation of a few drops of a 2 per cent, solution will quickly abolish painful sensation and lessen reflex sensibility to such a degree as to permit of easy removal of a foreign body even from the cornea. ■ Itching in various parts of body may require its application, either in aqueous solution or in form of the oleate. Painful conditions in the lower part of the bowel, as in dysentery, call for its use in form of suppository. In coryza it is useful in form of solution sprayed or dropped into the nostrils, but such use prolonged, or that of a cocaine snujff, presents great danger of habit formation. Internally it may be of use in persistent vomiting when this is dependent upon irritation in the stomach. Its use as a substitute for morphine in habitual use of the latter should be advised against, as it proves no aid in overcoming the habit, while the result is likely to be the continuance of both drugs or substitution of cocaine habit for morphine habit, which is no improvement. Earache, when not relieved by warm irrigation, calls for the application of cocaine; three drops of a 3 or 4 per cent, solution dropped into the ear wiU usually suffice. [A \| grain tablet (0.015 gm.) dissolved in eight drops of water, one-half used and repeated if needed.] Incompatibility. — Cocaine hydrochloride is incompatible with alkalies and alkaline carbonates, with tannic acid, with potassium iodide, and with some metallic salts. It is decomposed by 2^0/0.5.5^^;/^ jpermanganate. With solution of silver nitrate a white precipitate of chloride of silver occurs. A white precipitate occurs with a solution of borax or with a strong solution of phenol. Aids to the Action of Cocaine. — Other agents of the same class, that are less poisonous and sufficiently soluble, may supplant cocaine or be combined with it. It is preferable, in the interest of accuracy, to use the drugs separately; so that mixtures of cocaine with its substitutes need not be considered. For prolonged effect, as in nerve blocking, quinine and urea hydrochloride is a useful addition, but it is injected separately. If there is an open wound or denuded siu-face, as in case of a burn, cjrthoform powder is useful. Agents that lessen the blood supply to the part, as cold applications, will aid slightly. The use of adrenalin or other suprarenal products as an aid to the action of cocaine has become established. The claim that less cocaine is needed when so combined is borne out in the experience of surgeons. Two factors in its action serve to explain its value: first, it contracts the arterioles locally, thus lessening the amount of blood in the injected area; and, second, it lessens the activity of absorption into the circulation beyond the locality. which means that more remains just where its effect is wanted, and the danger of systemic poisoning is lessened. The combination is easily made by adding, to the solution of cocaine hydrochloride for each injection, several drops of the 1 : 1000 adrenalin chloride solution. Reports indicate that the cocaine strength of the solution can be considerably reduced. One series of 100 operations,* which included resection of the superior maxilla, removal of a goitre and complete removal of the larynx, were performed under the use of a solution consisting of 9 parts of a \| per cent, solution of cocaine and 1 part of adrenalin (1 : 1000). If the part to be operated upon admits of a ligature being placed about it, the entrance of cocaine into the general circulation may thus be limited and its local effect prolonged. ■Morphine has no local analgesic action, t therefore it is without value as an aid to cocaine. Poisonous Effects. — Antagonists. — Poisoning by cocaine may be due to a weakened condition of certain organs whereby they are rendered more susceptible of depression, or to an overdose (see Plate III), or to idiosyncrasy. The symptoms are variable, hence cocaine poisoning presents no distinct picture. ^Yhile the drug has the power to first stimulate and later depress the central nervous system, depression in some part may occur suddenly with irregularity of symptoms. The toxic effects may include : control, causes a marked fall of arterial pressure. The most serious conditions, then, are depression of heart, ^'asomotors and respiratory center. The combined result of these is to lessen the arterial pressure very decidedly, with a certain degree of asphyxia added. These are the conditions to be antagonized. Therefore, it appears at once that any agent that does not either stimulate the vasomotor system, the heart, or the respiratory center, is of no value. Nitrite of amyl and nitroglycerin dilate the arterioles by depressing the vasomotor system; they do not stimulate respiration and their direct action upon the heart is doubtful. Therefore, they should never be used to antagonize cocaine, chiefly because they will still further reduce the arterial pressure.* Our best antagonists will be those that increase arterial pressure by stimulation of both vasomotor centers and heart, and which at the same time stimulate the respiratory center. Three agents that act in all three ways are caffeine, strychnine and atropine (see Plate IV). Caffeine has a dose of 1 to 5 grains (0.06-0.30 gm.) and is soluble in not less than 25 parts of water ;t therefore it would be an impracticable substance to include in a cocaine solution. The proper salt of caffeine for hypodermic use is the official caffeine sodio-benzoate, soluble in 1.1 parts of water, dose 3 to 5 grains (0.200.30 gm.). The dose of strychnine sulphate is -^q- to y^ of ^ grain (0.001-0.006 gm.) and of atropine sulphate y^Q- to -^-^ of a grain (0.0050.001 gm.), and both are sufficiently soluble so that they may be combined in the same solution with cocaine. The dose for injection at one sitting should not exceed \| grain of cocaine hydrochloride, y^o" of atropine sulphate, and -^q^ of strychnine sulphate; then in case of danger symptoms from the cocaine the other drugs may be repeated in the same dose, but the atropine sulphate not more than once. It is well to have at hand separate hypodermic tablets of these drugs in the doses mentioned, not for routine administration in every case, but for use according to the operator's judgment. It would be unwise to depend upon these in order to exceed the safe dose of cocaine, but in persons known to be susceptible to its depressant action, or where such susceptibility is feared, it is proper to employ these antagonists in advance of the injection of cocaine. When poisoning occurs unexpectedly we may use the remedies mentioned above for the purpose of stimulating the whole central nervous system, in order to induce activity of cerebral functions, of respiration, and of circulation. Plate IV illustrates the action of these and of digitalis, which also is indicated if the circulatory failure is at all persistent. In this emergency fSi"! (1-4 mils) of tincture of digitalis may be given hypodermically. But it must be remembered that digi- * Nitroglycerin has been mentioned as an antagonist to cocaine, but it is contraindicated when blood-pressure is low. If there is much depression of the circulation it may do harm by further reducing blood-pressure. It is doubtful whether nitroglycerin has any direct stimulant action upon the heart. (See Plate XIII.) t Caffeine in its simple form is soluble in 46 parts of water and 66 parts of alcohol at 25° C. (77° F.), but the addition of benzoate or saUcylate of sodium renders it very soluble in water. Thus Caffeine-sodium salicylate is soluble in 2 parts of water and caffeine-sodium benzoate in 1.1 parts. Either may be used hypodermically in dose of 3 to 5 grains (0.20-0.30 Gm.). Citrated caffeine forms a clear, syrupy liquid with about 4 parts of hot water. Upon dilution with water, this yields a white precipitate (caffeine), which redissolves when about 25 parts of water have been added. emergencies. Adrenalin is among the most useful of agents for stimulating a depressed circulation. It acts both by direct stimulation of the heart and by constriction of arterioles, causing a decided rise of arterial bloodpressure. The disadvantage of uncertainty of action, unless employed intravenously, lessens its practical value in emergency cases. It gives no result when administered by the stomach and very little when injected h^-podermically in ordinary quantities; but its use by the latter method may be resorted to in emergency, 1 to 5 mils of the 1 : 1000 solution, diluted with ten times as much normal saline solution, being employed. Another of our most efficient circulatory stimulants is camphor, dissolved in oil, given hypodermically. The dose is gr. 1 to 5 (0.06-0.30 gm.). Immediate stimulation of both respiration and circulation should be secured also by administering, and applying to the air passages, some of the irritant agents that stimulate reflex activity by irritating sensory nerve endings. The chief preparations that act in this way are water of ammonia and spirit of camphor by inhalation; and for administration by the stomach, aromatic spirit of ammonia or alcohol, each in dose of 15 to 60 minims diluted with as much water. If necessary, repeat the dose of any in ten or fifteen minutes. The fact holds that these agents are useful mainly by reason of their irritant action. They should, therefore, be given without much dilution, so that their effect upon sensory nerve-endings in the mouth, throat, esophagus and stomach may be decided, and the consequent reflex stimulation of heart and respiratory center be efficient. Irritation of the skin by friction, slapping or faradism will act in the same way. If there be considerable depression of the respiration, as shown by slow or weak movements of the chest or by cyanosis, artificial respiration should be resorted to in order to secure proper oxygenation of the blood. (See Artificial Respiration.) In connection therewith massage of the heart by an assistant, by pressure between diaphragm and chest wall particularly with the movement of expiration, has come to be employed as an important aid in reestablishing the heart's efficiency. It is most effectual in cases where the irritability of the heart muscle is not much impaired. Substitutes for Cocaine. — The following list comprises the chief drugs that have been substituted for cocaine from time to time, some of which have been found wanting in essential qualities, some are still under trial, while others answer the purpose in varying degree. It is evident that any agent, in order to be entitled to consideration, must compare favorably with cocaine not only as to efficiency, but in addition must be less toxic, or its solutions must keep better, or it must possess some other decided advantage. Orthoform. Quinine and Urea Hydrochloride. These drugs are mostly alkaloidal in nature and, therefore, used largely in form of a soluble salt. Their properties will be noted briefly and comparisons of their efficiency and adaptability given in tabular form. Alypin (not official). — This name is usually applied to ah-pin hydrochloride, though the nitrate also is upon the market. As experiments have shown alypin to be fully as poisonous as cocaine (see pp. 182-183), it is destined to be discarded as a substitute. Its only place would seem to be in form of the nitrate when it is desirable to use a local analgesic in combination with silver nitrate, with which any soluble chloride would be incompatible. Alypin is freely soluble in water and in alcohol. Apothesin (not official) . — This is one of the newer synthetics for which important advantages are claimed, but the experiments of Sollmann seem to place it low in the scale of efficiency. (See pp. 182-183.) However, many practitioners have found it valuable. Beta-eucaine Hydrochloride is a white, crystalline, odorless powder, soluble in 30 parts of water and in 35 parts of alcohol. It is about onehalf as efficient as cocaine and about two-fifths as toxic. Its solutions keep well. It is more irritating than cocaine and it combines less efficiently with suprarenal preparations, as it does not constrict arterioles, but rather causes h^-peremia. It ranks as a fair substitute for cocaine in from 2 to 5 per cent, solutions, either for direct application to mucous membranes or for hj^Dodermic use. In 1 per cent, strength it may be substituted for cocaine in the solutions for infiltration anesthesia. Nirvanin (not official). — This occurs in crystalline or powder form, soluble in water and in alcohol, the aqueous solution being neutral and claimed to be germicidal in 1 per cent, strength. It is used in from 1 to 5 per cent, solutions, though it should be used with care, as it is reported to be seven-tenths as toxic as cocaine. Novocaine (U.S. P., Part II [C13H20O2X2.HCI]). — This drug has proved to be of such vakie as a local analgesic and substitute for cocaine as to merit a more extended description. It was discovered by Einhorn in 1905. It is a white powder, soluble in 1 part of water, the solution being neutral in reaction; soluble also in 30 parts of alcohol. A 10 per cent, aqueous solution is neidral to litmus. The aqueous solution, as usually employed, may be heated to the boiling-point without decomposition. It has the advantage of being non-irritating, since a solution of any strength, or even the powder, may be applied to the conjunctiva. It acts efficiently with suprarenal preparations, the effect being increased by the combination. Novocaine possesses the same action upon the peripheral sensory nerves as does cocaine, when directly applied to the nerve. The same is true of its use by injection and infiltration. However, by surface application, as to the cornea, its action is very much weaker than that of cocaine, but may be increased somewhat by the addition of sodium bocarbonate, according to Gros.* Since novocaine is only one-half as toxic as cocaine, it may be used more freely, although the systemic effects of large doses are essentially the same as those of cocaine; but when used in the ordinary dosage there are no systemic effects. Five thousand injections in the extraction clinic of the Dental School of the University of Buffalo, using a 2 per cent, solution in normal saline, with small adrenalin dosage, have shown no systemic reaction in a single case, the ages ranging from childhood to old age. Prinzf regards novocaine as the only one of these substances that meets the demands of substitution for cocaine. He cites evidence that its combination with adrenalin increases the efficiency of both drugs in their local action. He prefers a 2 per cent, solution and suggests the following : when used. Incompatibility. — Novocain in solution is incompatible with solution of mercuric chloride and with solution of iodine, a precipitate occurring with each. Mixed with calomel in equal parts, the mixture blackens when moistened with diluted alcohol. [It is not precipitated by borax Stovaine (not official) .—Occui-s in small scales, soluble in 2 parts of water and readily in alcohol. It is two-thirds as toxic as cocaine, but much more irritating. In recent years it has been brou^^ht into prominence through its use in spinal anesthesia. Tropacocaine (not official) .^An alkaloid from the leaves of Java coca, prepared also synthetically. It occurs in colorless crystals, soluble in water. It ranks well in efficiency, is one-half as toxic as cocaine, but is more irritating. It has the disadvantage of not acting efficiently with suprarenal preparations, since it destroys the vasoconstrictor action of the latter. Orthoform (U.S.P., Part II [CgHgOaN]).— A white, tasteless powder, sparingly soluble in water, but soluble in about 5 parts of alcohol and in 50 parts of ether; also soluble in sodium hydroxide solution. This drug is non-toxic in usual dosage, and, on account of its slight solubility in water, it has practically no penetrating power, therefore is useful only for surface action. It is not a substitute for cocaine in the usual use of the latter by injection, but it holds an important place for prolonged surface action, as in painful ulcers and, in dentistry, applied to a painful tooth socket after extraction. After operations upon the mouth or throat its application in powder form will greatly lessen the pain of movement or friction. It has been used internally to relieve the pain of gastric ulcer, the internal dose being from 2 to 15 grains (0.12-1 Gm.). Used in tablet form to be slowly dissolved in the mouth, it will often give much relief in cases of sore-throat. The hydrochloride of orthoforvi* is said to be soluble in 10 parts of water, the solution being acid in reaction, and having the same action, dosage and uses as orthoform. patible with silver nitrate, potassium permanganate and with zinc chloride. Quinine and Urea Hydrochloride occurs in colorless crystals or as a white granular powder, odorless and bitter to the taste. It is soluble in 0.9 part of water and in 2.4 parts of alcohol. The aqueous solution is acid in reaction. This agent is comparatively non-toxic, the internal dose being 15 grains (1 Gm.). It is about one-fourth as efficient as cocaine when injected into the tissues; however, it has the unique advantage of producing a more lasting effect — from several hours to several days. Accordingly, it is often used for continued effect, in con- and remained so. 4-5. — Xovocaine also fulfills conditions four and five and thus is the only one of the substitutes which fulfills all of the essential requirements for a local anesthetic. Indeed it may be said that this drug is an ideal local anesthetic for use in dentistry. Toxicity. — The following comparative table of toxicity of cocaine and its substitutes is of interest. It is based upon the minimum quantities causing death in frogs, mice and rabbits, the drugs being named in the order of their toxic effects. f Efficiexcy. — Solhnami* has investigated local analgesics in reference to their efficiency both by surface application and by injection into the tissues. The practical results of his observations may be thus tabulated, sho-^-ing the ratio of efficiency with cocaine as the unit : Xovocaine hydrochloride . . it Apothesin i A fact worthy of note in the above comparison is the very low efficiency of novocaine when applied upon the siu^ace to the cornea), as compared with its high efficiency when injected. It was found, however, that the addition of sodium bicarbonate increased the efficiency of novocaine, as also of the other agents, for siu-face effect. To state the matter definitely: If the anesthetic is made up "in double concentration, and diluted, just before use, with an equal volume of 0 .5 per cent, sodium bicarbonate solution, this increases the efficiency (for the cornea) as follows: Cocaine, from one to two times; beta-eucaine. two times; novocaine, from two to foiu* times; tropococaine or ah"pLn, four times." It must he emphasized that this result does not obtain with injection or infiltration uses of the drugs, but only with surface application. Another point arrived at by SoUmannf is that the suprarenal preparations, combined with the local anesthetic, while very valuable to prolong the period of anesthesia when the mixtiue is injected into the tis- Spinal Cocainization. — Among the methods of inducing analgesia, that of injecting a solution of cocaine (0.2 to 0.5 per cent, strength) into the spinal canal has been employed, having been first advocated by Dr. Corning, of New York. By this means all parts of the body below the point of injection may have sensation to pain abolished, so that it is possible to do even an extensive surgical operation by aid of this method. There are dangers attending this procedure, and its limitations have become recognized. When employed, the injection should be made as low down as possible, so as to avoid the efi"ect of the drug upon the medulla. The method for the present should be used only in those cases where a general anesthetic is contra-indicated, and where the site of injection may be at a point some distance from the medulla. A TOPIC of so great importance as that of general anesthesia merits brief historical references as to agents employed and their discoverers.* Ethylic ether, formerly called "sulphuric ether," and, still earlier, "sweet oil of vitriol," was known as early as the thuteenth century, but the name of its discoverer is unknown. While it was used for some medicinal purposes in the eighteenth century and probably earlier, and although its intoxicating and narcotic properties had been discovered, it was not employed for practical anesthesia until 1842. During several years it was put to successful practical tests by Crawford Long, of Georgia, by Horace Wells, of Vermont, and by W'illiam T. G. Morton, of Boston, the last-named having demonstrated its use in a public way in Dr. Warren's clinic at the Massachusetts General Hospital, October 16, 1846. With the discovery of chloroform four names must be associated: Guthrie, of Sackett's Harbor, N. Y., who is credited with its first discovery (1831); Liebig, of Germany, and Soubeiran, of France, who were close contemporaries with Guthrie in its recognition, and Dumas, who made known its composition in 1835 and gave it its present name. In 1847 it was introduced as an anesthetic by Simpson, of Great Britain, a physician of great prominence, who at once began to use it extensively in his practice. Nitrous oxide also was known for many years before it came to be practically applied as an anesthetic. It was first obtained by Priestly in 1772. In 1799 Humphry Davy, of England, observed the exhilarating and intoxicating effects caused by inhaling this gas, and published his tooth. The condition of general anesthesia must include more than the abolition of consciousness to pain, the removal of unconscious muscular activity being only secondary in importance. In many cases a comparati\-ely small amount of an anesthetic will suffice to abolish consciousness of pain, but muscular rigidity or activity will prevent the performance of a surgical operation. The term partial anesthesia is sometimes applied to a grade of effect where the cerebrum is paralyzed, with loss of conscious sensation, but where the reflex centers of the spinal cord are still sensitive, as shown by muscular activity whenever sensory nerves are irritated. In studying these agents we also recognize the possibility of securing a purely analgesic effect from smaller quantities than are required for anesthesia. This is particularly true of nitrous oxide, as will be shown later. As a class the t>i)ical anesthetics are peculiar in respect to the order in which the\' paralyze the different parts of the nervous system. At first thought the production of complete paralysis of all parts of the body capable of responding to external stimuli, by the administration of a substance foreign to the body, would seem to be an extremely dangerous procedure; and so it appeared until it was ascertained that the paralysis was induced in such order that the centers of consciousness were affected first and those whose activity is absolutely essential to life last. Any agent, therefore, to rank safely among this class of drugs must conform in action strictly to the lines of safety which have now become well established. Plate V. presents a division of the central nervous system into sections, which are nmnbered in the order in which they are paralyzed by anesthetics. It will be seen that the most highly developed, or differentiated, nerve tissue (brain) is first affected, while the simpler and more vital structures that are common to all forms of animal existence (those connected with the functions of respiration and circulation) a^e affected later, being apparently more resistant to the influence of the drugs of this class. It is remarkable that these century-old agents have never been supplanted by newer anesthetics. The past few decades, that ha\e yielded so much in the way of synthetic drugs, have not given us new general anesthetics, but have been devoted to a closer study of the old, as to their precise action, their dangers, and better methods of administration. That this has been a fruitful study is evidenced, among other things, 4, Circulation paralyzed The several sections are numbered in the order in which they are paralyzed by anesthetics. The paralysis of 1 and 2 constitutes surgical anesthesia, paralysis of 3 introduces an element of great danger, and that of 4 is usually fatal. [The heart is included in this diagram of the several parts of the central nervous system, for the reason that it contains nerveganglia, which, with their highly ii'ritable muscular structure, provides for its automatic, rhythmic action. This provision is quite independent of the cerebrospinal system.] MODE OF ACTION OF ANESTHETICS 187 by the adaptation of nitrous oxide to the field of general surgery, where it is now used so largely with satisfaction and safety. Another result is that the science of anesthetics has been so developed that now very few cases occur that cannot be safely anesthetized by an expert using the proper agent. It may be added also that the judicious use of other narcotics with the anesthetic, in order to render the narcosis more profound and to lessen shock, has become more and more a routine practice. This is particularly true of the hypodermic use of morphine (sometimes with scopolamine) preliminary to prolonged nitrous-oxide-oxygen anesthesia. Mode of Action of Anesthetics. — ^\'arious theories have from time to time been proposed to explain the mode of action of anesthetics, by ascribing their effects to action upon the blood, to alteration of the circulation within the brain, and to asphyxia; but the present belief is that these substances produce their effects chiefly by a direct action upon the nerve centers. As to the precise action of the anesthetic upon nerve cells, it has been observed that the volatile liquid anesthetics are fat solvents; and the investigations of Meyer and Overton led them, independently, to the conclusion that anesthesia is caused by the solution of the lipoid constituents of the cells by the absorbed anesthetic vapor. The fact of the transient influence accords with a belief in some such simple physical change as solution, which would obtain only while the vapor was present in sufficient quantity. This theory could hardly explain the action of nitrous oxide, a gas whose nature and properties differ so greatly from those of the other anesthetics. If a common action is to be found it must rest upon other facts. Blood Changes Induced by Anesthetics. — A number of observers have studied the blood in reference to anesthesia and some positive conclusions have been set forth as to changes in the blood caused by anesthetics. Ui^on Hemoglobin. — It is now generally recognized that the hemoglobin of the blood is diminished in varying degrees by these agents (by ether markedly and rapidly, by nitrous oxide slightly and transiently) and that any case having less than 60 per cent, of hemoglobin would be hazardous under ether, and probably under chloroform, which increases hemolysis as well. ments upon animals. Upon Alkalinity of the Blood. — Acid products are increased in the tissues and blood during anesthesia, chiefly because of diminished oxidation. In prolonged anesthesia this may reduce the alkalinity of the blood to a serious degree. When there is muscular activity during partial anesthesia the natural production of acid is increased, and if cyanosis is present, indicating a great diminution of oxygen intake, the acidosis may be a factor of great danger, not simply during anesthesia, but afterward. Hemorrhage increases this danger, because a diminished circulation brings less oxygen to burn up the accumulated acid products. Thus, acidosis (or high concentration of hydrogen ions) probably is the important factor in auto-intoxication that often follows surgical anesthesia, and which must be distinguished from surgical shock. Upon Blood-pressure. — The tendency is for blood-pressure to diminish during anesthesia that is at all prolonged, but the effect varies according to the agent employed; with chloroform the fall usually begins by the end of fifteen minutes and rapidly reaches its minimum within a few minutes; with ether the fall does not usually begin under twenty minutes and is then very gradual, often continuing and reaching its minimum after the operation has been completed and the anesthetic removed; with nitrous-oxide-oxygen no change in blood-pressure attributable to the anesthetic is seen within two hours, and any fall occurring after longer administration has been found to disappear promptly upon removing the anesthetic, f Since nitrous oxide is reputed to raise bloodpressure, which may be true of the gas given undiluted because of the attendant asph^-xia, the fact is worthy of emphasis that the mixture with oxygen does not show clinically any rise of blood-pressure. Asphyxia. — The condition of asphyxia (which, in this relation, may be defined to be lack of a sufficient ox^'gen supply to the cells of the tissues), is, without question, a factor in anesthesia in cases where an agent is administered with a limited supply of air. It was formerly held by high authority that nitrous oxide anesthesia was due simply to asphyxia, but this has been disproved by the fact, now daily observed, that anesthesia is induced by nitrous oxide when mixed with sufficient oxygen to prevent asphyxia. It is simply a question of dep^i^^ation of oxygen, without which the cells cannot function; and it is only with the use of ACTION OF ANESTHETICS UPON NERVE CELLS 189 nitrous oxide alone and of ether by the old, closed inhaler method, that we encounter asphyxia in any important degree. However, asphyxia is of primary importance in its causative relation to auto-intoxication, under which topic it will be further discussed. Action of Anesthetics upon Nerve Cells. — While the precise action that determines the paralysis of function of nerve cells in the state of anesthesia has not been demonstrated, much light is thrown upon the question by Lillie in his comprehensive article on "The Physico-chemical Theory of Anesthesia," which details the researches of himself and others. Lillie defines anesthesia, in reference to all responsive tissues, as "the ijhenomenon oj reversible decrease of activity of responsiveness." He argues from the proposition that the response of cells to stimulation probably begins at the surface of the cell, i. e., that surface changes, where the cell-wall (or "plasma membrane") must first meet the stimulating agent in the surrounding medium, are responsible for the activity that follows in the cell as whole. It is evident that anesthetics decrease temporarily the responsiveness of nerve cells, and it is reasonable to assume that the action begins at the smface where the anesthetic first reaches the cell. But whether the action consists of physical change of the fat-like (lipoid) constituents (Meyer and Overton), whether, by this or other change, oxidation is restrained, or whether the protein constituents are affected either physically or chemically, remains to be proved. Lillie believes that the action begins at the surface. To quote from his earlier-expressed view, "anesthetic action is due primarily to a modifi-' cation of the plasma-membrane of the cells or irritable elements, of such a kind as to render these membranes more resistant toward agencies which under the usual conditions rapidly increase their permeability; cytolysis and stimulation, both of which depend on such increase of permeability, are hence checked or prevented .... this effect is produced by various salts, e. g., of magnesium, and by ether and other lipoid-solvent anesthetics in certain, not too high, concentrations. .... It seems clear that for irritable tissues the state of the lipoids in the plasma-membrane largely determines the readiness with which changes of permeability — and of the dependent electrical polarization — are induced by external agencies." The essence of this theory seems to be that the anesthetic in some way lessens the permeability or the electrical conductivity of the cell surface, so that response to the usual stimuli is prevented. 190 ANESTHETICS We may state, therefore, that present theories are \ariously characterized by (a) behef in physical change of the Hpoids, (h) in decreased oxidation, and (c) in alteration of electric polarization upon the cell surface; also, that these theories deal more with the mechanism of induction than with the essential state of the narcotized cell. Whatever theory is fa^'o^ed, it is evident that the phenomenon of anesthesia involves selective action, i. e., certain nerve centers are affected before others. The usual order is for the cerebral areas to be affected first, the spinal cord second, while the medullary centers are affected last. In fact, any agent whose action does not exhibit this selective order cannot rank as a safe anesthetic, for the respiratory centers in the medulla must remain active during anesthesia of brain and spinal cord. A recognition of this order also furnishes an index as to danger or safety in the course of its inhalation. Plate V. will aid us in appreciating the stages tlirough which the action of anesthetics may extend, the numbers 1 and 2 pertaining to essential and safe anesthesia, and 3 and 4 to the dangers of profound anesthesia. Stages of Anesthesia. — Descriptions of the stages of anesthesia are sometimes so elaborate as to be confusing. The simple division of Cushny into three stages seems sufficient for ether and chloroform at least. A. Imperfect Conscionsness — At the beginning the inhalation may be accompanied by a sense of suffocation, which is greater with ether than with chloroform and is seldom present with nitrous oxide. The cerebrum is very quickly affected, with the production of ^•arious manifestations of disturbed or uncontrolled nerve function, such as incoherent talking, laughing or crying, indefinite muscular movements and holding of the breath. The pulse is not much influenced as a rule. Respiration is quite normal except for the influence of the early choking sensation when the anesthetic vapor is too concentrated. specJal senses may be disturbed. Coughing is occasionally present. B. Excitement. — With consciousness completely abolished, the control of the lower part of the cerebrospinal system by the cerebrum is removed, and we see accordingly various manifestations of uncontrolled reflex activity. The centers here concerned are mostly situated in the spinal * This stage is described by some authorities as the stimulant stage, but the stimulant effects noted are mainly reflex, while the real concUtion is one of depressed consciousness. There is frequently noticed quite early a very brief period of complete relaxation, during wliich a slight operation might be performed. IMPORTANT THINGS TO WATCH 191 cord, which is the second division of the nervous system to be influenced by anesthetics. (See Plate V.) Being not yet depressed to any marked degree, the impulses that it originates without cerebral control may produce the most violent muscular action, which is likely to be most marked shortly before complete relaxation occurs. This stage of excitement is more decided with ether than with chloroform, whose general depressant effect is early evident, or with nitrous oxide, whose action in every stage is transient. The pulse is not much altered. Respiration may be interrupted by rigidity of the respiratory muscles. The pupils are apt to be dilated during excitement. They are responsive to light as long as reflex irritability persists. Increased secretion of tears, and of mucus in the upper respiratory and oral regions, occur. Vomiting occurs as a very unpleasant complication if the stomach contains any food, especially when ether is employed. During this stage consciousness to pain is abolished, but, as a rule, surgical procedure is impracticable until complete relaxation occiu-s, with cessation of reflex excitement, which marks the beginning of complete anesthesia. Relaxation is generally accompanied by snoring inspirations due to vibration of the relaxed soft palate. C. Anesthesia. — AYith the occurrence of complete anesthesia the whole muscular system is relaxed, sleep is profound and reflex activity is absent; in fact, there is temporary total paralysis of nervous and muscular systems, except those parts concerned with respiration and circulation. The pulse is not much altered in rate, but blood-pressure may be lessened (vide ante). Respiration is full and regular, as during profound sleep. The pupils are usually contracted and do not respond to light. The cornea is insensible to touch. The general appearance does not differ much from that of a person in a deep sleep. However, with ether the face is apt to be more flushed than with chloroform. ^Yith nitrous oxide given alone some degree of cyanosis occurs. thetic may be grouped as below: First, as indicating the progress and degree of anesthesia: (a) The activity of the reflexes. (6) The degree of muscular resistance. (c) The condition of the pupil of the eye. As shown in Plate \, reflex activity persists after consciousness is lost, but disappears with surgical anesthesia. Therefore, as long as any response to irritation of a highly sensitive area occurs, and as long as any muscular rigidity exists, we cannot say that the proper degree of anesthesia has been reached. The usual way of testing reflex irritability is by toching the cornea or conjunctiva of the eye with the finger, which should be clean. The reflexes of the eye being among the last to disappear, any response by a closing movement of the eyelids shows that irritability of reflex centers still persists, while absence of any response usually indicates that anesthesia is complete. Muscular resistance is usually tested by raising the patient's arm to full length perpendicularly and allowing it to fall. iVny slowness or interruption in its fall shows muscular response and indicates that anesthesia is not complete, while a sudden drop of the arm, as if paralyzed, shows complete muscular relaxation and indicates that anesthesia to a surgical degree has been secured. Muscular resistance often persists after ordinary reflex response is lost. This is of special importance in dental operations, where it is frequently found that the jaws are rigidly closed wdien anesthesia seems complete. In such cases it is necessary to push the effect beyond the degree which might suffice for an operation upon an accessible surface, in order to secure relaxation of the jaws, unless a mouth-gag or a cork be used to keep the jaws apart during the wdiole period of inhalation. Again, owing to the necessity of suspending inhalation of the anesthetic during the dental operation, as for extraction, it is advisable to push the administration to a profound degree, so that the effect may last during the brief operation. This is permissible with the safer anesthetics, which do not endanger the heart's action. It may be stated, however, that an operation may be completed even after reflex activity is again evident, provided that muscular resistance does not prevent; for if consciousness be still abolished the patient cannot interpret the surgical irritation as pain, and will remember nothing of the operation, even though some struggling may have occurred through reflex activity. Such a practice, however, is not permissible with chloroform, in fact is dangerous, as will be explained in discussion of that agent. The pupils remain responsive to light so long as anesthesia is not complete, w4th a tendency to dilatation during the early stages, due to the excitement that is more or less evident. With complete anesthesia the pupils contract and become fixed, i. e., they do not respond to light, and appear in all respects as they do during profound sleep. After complete anesthesia has been induced, dilatation of the pupil may mean either slight return of reflex activity, which will be accompanied by the eye reflex and may call for more anesthetic, or it may mean a paralysis. which indicates a most serious depression of the nervous system that may be speedily fatah The latter will be unaccompanied by any sign of reflex activity or of muscular resistance, but relaxation will be complete. It must be insisted upon that the respiration be watched closely throughout, for it has been shown that death by anesthetics is due, in the majority of cases, to failure of respiration centrally, by paralysis of the respiratory centers in the medulla. Early in the administration respiration may be interrupted by choking sensations, and after consciousness is lost there is often some stoppage due to reflex muscular action; with ether this may be so marked as to cause a considerable degree of cyanosis. These interruptions are temporary, and as long as the pupils are responsive they need not occasion any alarm, for any stoppage of respiration before anesthesia is complete is not dangerous, except, that mechanical closure of the glottis by falling back of the tongue might occasion a continued stoppage, resulting in fatal asphyxia. This cause will be removed by drawing the tongue forward by forceps or a silk ligature passed through it, or by either of two simple procedures that are usually successful — turning the head to one side so as to allow the tongue to fall to the side, and drawing forcibly forward both angles of the lower jaw. Whenever interruption of respiration has occurred reflexly or mechanically, the first succeeding inspiration is apt to be deep and forcible. With chloroform especially, care must be taken not to allow free access of the drug with this deep inspiration, for fear of suddenly poisoning the heart by too much or too concentrated vapor. It is most important to watch the respiration at this time. Any irregularity or interruption is a danger sign, and must require suspension of the inhalation, free access of air, and respiratory stimulants. If cessation has occurred, artificial respiration must be resorted to at once. To begin with, these measures may be instituted without regard to the pulse, for, with respiration paralyzed, the pulse may still be feebly perceptible, or the heart may be beating so feebly as to cause no pulse in the peripheral vessels. In either case the rapid elimination of the drug urgently required. TJie pulse tells us of the rapidity and rhythm of the heart's action and of the condition of arterial pressure. It may be felt at the wrist, but is very conveniently felt by the anesthetist at the temporal artery. Any excessive rapidity (say above 120 per minute) and, even more important, any irregularity or inarked weakness of the pulse beats, should enlist attention. Rapidity and irregularity are necessarily due to conditions in the heart or its regulating mechanism, while weakness of the pulse may be due in part to low blood-pressure from relaxation of the arterioles. Stimulation of the circulation during anesthesia requires those agents that will maintain arterial pressure, and forbids the use of vasodilators which lower arterial pressure. The recumbent posture with head low must be maintained when the pulse is weak or irregular. With ether, the pulse seldom shows any danger symptoms, but remains quite normal throughout, except that in prolonged anesthesia arterial pressure is lessened. With chloroform, the direct depressant action of the drug upon the heart and vasomotor system is added to the general depression of anesthesia, and there is accordingly a weaker pulse, lowered arterial pressure, and less ability to regain the normal in case danger symptoms occur. A sudden failure of the heart, even early, is sometimes observed with the administration of chloroform. This may be due either to cardiac disease which permits the organ to be easily overcome, or to too rapid or too concentrated inhalation of the vapor. The necessity impresses itself of watching the pulse carefully throughout the administration of chloroform. According to Levy there is less danger from overdose of chloroform than from intermittent administration. {See under Chloroform.) The Pujnls. — The danger symptom that may be presented by the pupils occurs only during profound anesthesia, and consists of dilatation. This may represent stimulation of the dilator center due to asphyxia,* but it has also been taken to mean a paralysis of the contractor fibers. It is possible that in different cases both explanations may find application. Paralysis would, of course, be regarded as the more serious condition. During profound anesthesia the pupil should be observed veryjrequently, and any dilatation not accompanied by response of reflexes should require suspension of the anesthetic and immediate attention to the patient's condition. Recovery from Anesthesia varies in time from a very few minutes after nitrous oxide and chloride of ethyl, to several hours after ether. The patient may pass through a stage of excitement similar to that preceding anesthesia, but less pronounced as a rule. Vomiting almost invariably occurs when much ether or chloroform has been used. After these drugs there is also a tendency to sleep, and normal consciousness may not be restored for several hours. Contra-indications to Anesthetics. — In general, we may say that anemia, disease of brain, lungs, heart, bloodvessels or kidneys contra-indicate general anesthetics. But a general rule admits of many exceptions, and, therefore, with respect to this matter each case must be judged by itself. As to contra-indications to individual agents more definite statements can be made. For Nitrovs Oxide. — It is usually held that serious heart or lung affections, that will easily lead to embarrassment of respiration or circulation when the asphyxia accompanying the use of nitrous oxide is added, should prohibit the use of this gas; also that disease of the arterial walls to the point of weakening them, presents the danger of rupture under nitrous oxide. This statement is based upon the fact that asphyxia leads to contraction of arterioles, with increased blood-pressure in the smaller arteries. Apoplexy, from arterial rupture within the brain, would be the most serious result to be feared. These contra-indications may be largely removed by the combined administration of oxygen with the nitrous oxide. For Chloroform. — In addition to the general statement above, we should note that disease of the heart muscle (myocarditis, myocardial degeneration or fatty degeneration) prohibits the use of chloroform. As this drug is capable of causing fatty degeneration of various organs, the structure of all circulatory and eliminative organs should be normal in order to admit of its use. Valvular disease of the heart, if well compensated, is less a contra-indication than is degeneration of the heart muscle as indicated by weakness, irregularity or dilatation. It has been shown by experiments upon cats, that the administration of adrenalin under light chloroform anesthesia is usually fatal. In the human subject also cases of death have occurred under similar conditions.* Suprarenal preparations, therefore, are positively contra-indicated in chloroform anesthesia. that ether has very little depressant action upon the heart; on the contrary, it diminishes the hemoglobin appreciably and would, accordingly, be contra-indicated in any case of anemia showing GO per cent, or less of hemoglobin. On account of the comparatively large amount of ether required, it is believed by some to be particularly damaging to the eliminative organs, especially the lungs and kidneys, but it is probable that the effects here are less permanent and less serious than those produced by chloroform.* While we should always give due place in our judgment to the general contra-indications previously stated, when any anesthetic is in question, yet, when we have mentioned the unpleasantness of ether inhalation, the excitement that it frequently causes, and the prolonged and uncomfortable period of recovery, we have made our chief complaints against ether. It stands first as a safe general anesthetic for profound and prolonged effect. Auto-intoxication and Asph3rxia. — One danger of anesthesia that has not been sufficiently recognized is that of auto-intoxication. Asphyxia is an important factor in causing this condition, as by the deficiency of oxygen the normal elaboration and final oxidation of tissue elements is interfered with; consequently elimination is deficient and acid waste products accumulate in the tissues. Also after chloroform and ethyl chloride (and other related chemical substances which yield a halogen acid, e. g., ethyl bromide and ethyl iodide), degeneration of liver cells easily occurs as well as other tissue changes. There is a growing belief that auto-intoxications and fatty degeneration of organs in connection with anesthesia are due mainly to acid products. Lack of oxidation may be responsible in part for the accumulation of these, or one of the halogen acids may be liberated from certain anesthetics. f Cases of death occurring several days after the use of ether or chloroform, the immediate effect of the drug having been recovered from, are often due to auto-intoxication rather than to the particular anesthetic employed. It is true that nitrous oxide anesthesia, as usually employed in dentistry, is so brief that the asphyxia that necessarily attends it because of the closed inhaler used, may be disregarded as of light importance; but its prolonged use now so common in general surgery, should be accompanied by inhalations of oxygen. While we may not insist upon the use of oxygen as routine practice in connection with anesthesia of moder- ate duration, it is certainly advisable in greatly prolonged anesthesia with any agent; and objection must be made to inhalers for ether, ethyl chloride, or chloroform that do not admit enough air for proper oxygenation of the blood. The practice of rebreathing the same gases during anesthesia also is to be discouraged, unless for short periods or under expert supervision. An expert will often employ rebreathing, but with sufficient pm-e oxygen to avoid asphyxia. Preparation of Patient for Anesthesia. — For ordinary nitrous oxide anesthesia it is only necessary to be assured of the non-existence of serious disease in vital organs and in the arterial walls, and to observe the general precautions to be given later. For prolonged use of the same agent, similar preparation should be made as for ether and chloroform. Before employing ether, chloroform or ethyl chloride, preparation should be made in order to avoid unpleasant or dangerous complications both during and after the administration. Except in emergencies that seldom occur in dental practice, an anesthetist is not justified in administering one of these agents without first ascertaining that no disease exists in heart, lungs, brain, bloodvessels and kidneys, nor any anemia, sufficient to constitute a contra-indication. It is essential to examine the patient's urine in every case. The blood-pressure should be taken as a rule, and the blood examined in any case that presents the appearance of anemia or chlorosis. [Less than 60 per cent, of hemoglobin should contra-indicate the use of ether, chloroform or ethyl chloride, but nitrous oxide may be used with care.] To this routine is added the positive injunction to the patient to take nothing into the stomach for at least five hours before the operation is to occur. This will avoid vomiting during the administration. A free cathartic should be employed within the twenty-four hours preceding the operation, particularly if constipation is present. An imjjortant precaution, that should invariably be taken if the patient be a woman, is to have a third party present, which in case of dental operations may preferably be a friend of the patient. A case is recorded where the imaginations of an anesthetized woman were such as to form the basis of a charge of criminal assault against the operator;* therefore one should guard against such an unfortunate possibility in any case of anesthesia under his direction. appliance must be renl()^■e(l from the mouth. Wlien ether or chloroform is to be used it is well to protect the eyes from the irritating vapor by covering them with a towel. If the greatest care is not exercised as to quantity of liquid applied to the inhaler it may drop upon the face and irritate the skin. Some anesthetists protect the tissues about the mouth and nose by covering the skin and lips with a light application of sweet oil or vaseline. The patient must be informed of the pr()l)able unpleasantness of the vapor, so as not to be surprised by the sense of sufl'ocation. The clothing about the neck, chest and waist should be sufficiently loose to allow of free respiratory movements, and the patient should finally l)e instrueteil to breathe deeply. In case of emergency requiring an o])eration at night, ether must not be used in the presence of a gas flame or ordinary fire. The vapor of ether Is explosive * It is also heavier than the air, and will fall to the floor and diffuse itself mainly in the lower part of the room. It may, therefore, reach an open fire at some distance in explosive strength, without being particularly evident in the upper part of the room. The only safe light to use about ether is the incandescent electric light, which is fully enclosed. Vov the same reason, it is necessary to observe some care in handling ether. It should be kept and handled in tin cans rather than in bottles, in order to avoid accidental breakage with dift'usion of the explosive vapor. Responsibility in the Use of Anesthetics. — With all precautions taken, it still remains a fact that occasional deaths attend the use of anesthetics. Therefore, the question of responsibility in their use becomes an important one. For slight operations, such as tooth extraction, that do not * In order to ascertain the degree of explosiveness of ether vapor, a series of ten experiments were made by Government Chemist Albert P. Sy, M.S., at the Sandy Hook ProA-ing Grounds, in March. 1904. The tests were made with mixtures of ether vapor and air in strong glass flasks, through which the electric spark was passed, explosion being e^^denced by blo^sing out of the cork. In four of the experiments, with mi.xtures containing from 0.9.3 per cent, to 1.65 per cent, by volume of ether vapor, no explosion occurred; while the other six experiments, \\-ith mixtures containing from 1.67 per cent, to 2.39 per cent, by volume of ether vapor, were each attended by explosion. The minimum percentage attended bj' explosion was 1.67 by volume, which is the equivalent of 0.355 pound of ether vaporized in 100 cubic feet of air. Report of War Department, Chief of Ordnance, 1904, vol. x, p. 163. These experiments would seem to incUcate that in a room of 1000 cubic feet space (10 X 10 X 10 feet) anything less than 3.5 pounds of ether could be vaporized without danger of explosion. This degree of concentration would never occur with the ordinary use of ether as an anesthetic. The chief danger wou'd probably be in the irregular diffusion of the vapor by reason of its weight, allowing concentration in some part of the room near a flame. absolutely require it, it is well to place the responsibility of deciding for an anesthetic upon the patient. With the decision made and the proper agent selected, it remains with the operator to bring to its administration the requisite knowledge and skill; and the dental practitioner must determine how far he will here assume the responsibility. It must be said that the dental curriculum of study does not provide sufficiently for training in physical diagnosis and general clinical work to fit the dental specialist for the office of anesthetist. It is doubtless proper for him to administer nitrous oxide, but to be prepared in all points that are involved in the use of ether and chloroform requires a broad medical training and considerable experience. The course that is most natural and that places the responsibility where it really belongs, is to refer the whole matter of general anesthesia in any case to the patient's own physician, both for decision as to the propriety of anesthesia and selection of the agent, and also for its administration and the general care of the patient. These suggestions are based upon an appreciation of what might be the result of an accidental death, where it was made evident that the anesthetic was employed without every reasonable precaution having been taken. Recent years have seen the development of the professional anesthetist, to whom we owe much of the progress evident in our knowledge of anesthetics and in improved methods of employment. It is customary now for a surgeon to have his own special anesthetist. In any case in which there is question as to the ad^^sability of giving a general anesthetic, it is well to have the services of the expert in anesthesia who should, as a matter of course, have had a medical training. Nitrogenii Monoxidum. Nitrous Oxide. — A gas having the formula X2O, capable of being liquefied under pressiu^e. It is colorless, having a slight odor and a sweetish taste. It is soluble in water and in alcohol. It is not combustible, but will support combustion. This gas was formerly prepared by the practitioner for his own use, by heating ammonium nitrate in a retort to the point of decomposition. It was collected and stored for use in an ordinary gas tank over water. Care had to be exercised to avoid a degree of heat that would develop the higher, poisonous oxides of nitrogen. This method of home manufacture is now well-nigh obsolete, as the gas can be obtained in liquid form in cylinders of convenient size, and with greater assurance of purity. upon vital structures are so slight and unimportant, and the duration of its main effect so brief, that in properly selected cases it should be absolutely safe. ^Yith the very few cases of reported death from inhalation of this gas, it may be questioned whether the results could be attributed entirely to it. It has been largely used to induce transient anesthesia for slight operations, its most extensive use having been for tooth extraction. At present it is also used in general surgery, and its use has been extended in two special ways, first, by its emplo.Miient to secure anesthesia quickly, to be followed by ether, thus shortening the period and removing the unpleasantnessof the early part of ether administration; and seco?id, by its combined inhalation with oxygen, whereby the element of asphyxia is removed, permitting the anesthesia to be continued indefinitely. By this latter method nitrous oxide has been adopted by many surgeons as the anesthetic of choice in general surgery; and even for major operations it is largely used, always with oxygen, and supplemented by a small amount of ether in suitable cases. Nitrons Oxide Analgesia. — A comparatively new use to which nitrous oxide is adapted is that of inducing analgesia, without loss of consciousness, for any desired time during the preparation of cavities in sensitive teeth. A nitrous-oxide-oxygen mixture is used, such as experience shows will maintain a state of analgesia without any asphyxia or loss of consciousness. The nasal inhaler must be employed. As a matter of course, experience will be needed to employ this method expertly, but it contributes to the facility of handling a class of hypersensitive cases greatly to the patient's comfort. ComjjJete Anesthesia may usually be induced by pure nitrous oxide in from two to five minutes, and recovery occurs in an equally short time. With the full effect obtained quickly, it is not so easy to define stages of action, but we may note about the same order of paralysis as with ether. The disturbance of consciousness is quite characteristic, in that the emotions are prominently affected, laughing being so often induced as to lead to the popular designation of the substance as "laughing gas." Reflex activity is likewise often evident, the patient sometimes even needing restraint. "When the gas is given mixed with air, the excitement is apt to be greater and the anesthetic effect more slowly produced. The most striking feature of nitrous oxide anesthesia produced rapidly, is cyanosis due to the exclusion of oxygen — really asphyxia. It has been held by some that anesthesia by this agent is simply asphyxia; but, although asphyxia will induce unconsciousness, it is easily demonstrable that nitrous oxide has a specific anesthetic action, for, with a patient the latter for continued administration in operations about the mouth. The inlialer is of rubber, or of metal or celluloid with the edges applying to the face covered with a rubber air-cushion, so as to apply closely. Celluloid has the advantage of transparency. The part where the gas enters and the air of expiration escapes is usually of metal, while the tubes are of flexible material. For prolonged operations about the mouth the pharyngeal method is often employed. Instead of the usual inhaler this method employs two small tubes which pass through the nostrils into the pharynx, thus leaving the face entirely uncovered. As to the apparatus, the old gas tank of the dental office, for nitrous oxide alone, has been supplanted by several makes of portable apparatus arranged for combined use of N2O and O, with means of easy regulation of the mixture. Some of these are sufficiently light and compact to be carried about when necessary. Such apparatus accommodates separate cylinders of N2O and of O, with rubber gas bag to receive the mixture, while the regulating mechanism permits the use of pure X2O or any desired mixture, or pure O if emergency requires. sensation is the only essential. Mthei. — Ether. — Ethylic Ether. — Composed of 96.5 per cent, of ethyl oxide [(C2H5)20] and 3.5 per cent, of alcohol; prepared by the action of sulphuric acid upon alcohol, hence sometimes called "sulphuric" ether. It is a light, colorless, volatile liquid, with a penetrating odor and disagreeable, burning taste,, having a specific gravity of 0.713 to 0.716 at 25° C. (77° F.). Its vapor is about 2^ times heavier than air, and may be explosive when mixed with air and brought into contact with a flame. It is soluble in about 12 times its volume of water, and is raiscible with alcohol, chloroform and oils. Average internal dose, TTl 15 (1 mil). Ether boils at about 35° C. (95° F.). One test of its strength is that, in a test-tube half-filled and containing fragments of broken glass, it should boil by the heat of the hand, when the tu})e is closely grasped and held for some time. The vapor being explosive, ether should be Ether, in the concentrated form which it is administered, is more in tating than chloroform, tiierefore tlie pi mary reflex stimulation and the lat' excitement are mucii more pronouncer It may cause danger by paralysis ( respiration, but the heart is depress* so slightly that recovery may usually 1 secured. iiig all of its functions. Medulla. Of the whole central nt vous system the medulla is affecti last. In dangerous narcosis the i spiratory and vasomotor centers a ])aralyzed. unless administration is prolongs when some depression may occur. Capillary area. Home dilatation cutaneous arterioles usually occu with flushing of the face. Eye. Pearly the pupils are dilated. Duri' complete anesthesia they are cr tracted. With dangerous paraly; they dilate. Mesjiiratioit. May be irregular or i terruj)ted during partial ane.sthes During full anesthesia it is regul and normal, as during sleep, According to Cushny, it is 3 to 3H times _as depressant to the central ner\'ous sj-stem, and 25 to 30 times as depressant to the heart, as is ether. It usually causes death by paralysis of respiration, the heart continiiing to beat, though so greatly depressed as to prevent recovery in many cases. However, it is believed by many that the heart may in some cases be paralyzed first. This is probably true in cases of degeneration of the heart. Locally applied, the drug is an in-itant, especially when the vapor is confined, as in the production of a " thimble blister." Sympathetic Respiration. During partial anesthesia it is dLstiirbed in a reflex way less than with ether. During full anesthesia it is regular and normal as during sleep. In dangerous narcosis it fails through pai-alysis of the respiratory center. Temperature is reduced during anesthesia. Melaholism. Destruction of proteids is increased with less pei-fect oxidation. Fatty degeneration of heait, liver and kidneys may occur. The drug is eKminated chiefly by the lungs, but it has been found in the urine. General Uses. — ^When applied to the skin the rapid evaporation of ether causes a decided cooling of the surface; applied to the mucous membrane it is irritating. The stimulant use of ether preparations depends largely upon this irritant quality. The spirit and compound spirit are employed in moderate doses as stimulants, the effect being reflex from local irritation of the mucous membrane. In large doses these preparations are anodyne after absorption. other substances not readily soluble in water. As an Anesthetic. — Since its introduction, three-fourths of a century ago, ether has stood as our typical anesthetic, combining efEciency with a high degree of safety, and applicable in nearly all conditions requiring a general anesthetic. With a recognition of the greater dangers of chloroform, ether came to be accepted as the routine agent in general surgery. But in more recent years, the development of nitrous-oxideoxygen anesthesia has given advantages that have led to its use instead of ether to a considerable ex?tent; but even this new^er method must rely upon ether as an addition in many cases, for profound anesthesia. So we may say that ether holds its place of primacy, while chloroform has fallen to a status of very restricted use. Administration. — It has long been held that the inspired air may be fully saturated with ether vapor and thus inhaled for a considerable period with safety; more than this, the older methods of etherization employed a nearly closed inhaler into which ether was poured by the one-quarter to one-half ounce at intervals. This demonstrated clinically that ether could be given with a limited supply of air supersaturated with ether vapor. This evidence of the safety of ether led to indifference as to method of its use, so that the giving of ether was oftentimes assigned to a junior hospital interne, or to an undergraduate with no training or experience in anesthesia. But that has all been changed with the recognition of experts in anesthesia, so that the surgeon now wants his special anesthetist or, at least, a person trained or experienced. The resultis that, with the knowledge of grave dangers incidental to pro- longed narcosis even with ether, great care is now taken as to the method of giving and amount given; for it is a cardinal point that the greater the amount introduced in a given time the more profound the narcosis, and the greater the interference with oxidation in the cell, and the occurrence of acid intoxication. inhalers of various makes, all of which secure a more perfect vaporization and more definite admixture with the inspired air. They allow free access of air, and the ether is added drop b}' drop instead of being poured in in bulk. The simplest form of open inhaler is the Esmarch (see Fig. 10), or some modification of it, so commonly used with chloroform. Similar to this, but adapted to the drop method for ether by being made to fit more closely to the face, inhalers such as are shown above are much used. The gauze covering is easily added for each administration. CHLOROFORM UM 205 The double chamber supphes a space in which the vapor is warmed to. some degree by the expired air, so that vaporization is faciUtated and the mixture is less cool for inspiration — a point to be considered in prolonged anesthesia. This inhaler, covered with about 8 layers of gauze, allows an ether vapor percentage varying from 6 to 22 per cent., the average of which (12 to 15 per cent.) would represent the usual desired dilution. [15 to 30 per cent, is needed for induction, but the lower percentages suffice to maintain anesthesia.] The disadvantages of ether commonly experienced are two — first, the unpleasantness of the vapor, which will cause a sensation of irritation and suffocation if not skilfully given; and second, nausea and headache following the narcosis. The first can be met by inducing slight anesthesia with nitrous oxide or ethyl chloride, changing to ether when the sensations are benumbed; or a few di'ops of oil of orange preceding the ether will sufficiently mask its odor, if the latter is then given slowly at the start. However, there is usually no difficulty if the patient is instructed and reassured in advance and the ether given slowly and with plenty of air at first. ^Nlore difficulty is experienced with children before the age of cooperation, so that the preliminary use of ethyl chloride or nitrous oxide may be advisable; though much can be done with a sensible child through reassurance and the use of the pleasant oil of orange at first. The second disadvantage, nausea and headache following, cannot be met so easily. These symptoms belong to intoxication by narcotics generally, e. g., morphine and alcohol, and little can be done to mitigate them, except to limit the amount of drug used. Chloroformum. — Chlorofor:m [CHCI3]. — ^This stibstance is prepared by the action of clilorine with an alkali upon alcohol, and is composed of 99 to 99.4 per cent, by weight of absolute chloroform and 1 to 0.6 per cent, of alcohol. It is a heavy, colorless, volatile liquid, with an ethereal odor and sweet, burning taste, having a specific g^a^^ty of not less than 1.474 at 25° C. (77° F.). It is soluble in 210 volmnes of cold water and freely in alcohol, ether, benzin, benzol and the fixed and volatile oils. Chloroform should be kept in dark-colored bottles in a cool and dark place. It is not inflammable, but its heated A'apor will burn with a green flame. Average internal dose, lU 5 (0.30 mil.). C : Aquae chloroformi (about 0.5 per cent.). f54 (15 mils.). Spiritus chloroformi (6 per cent.), TO, 30 (2 mils.). Linimentum chloroformi (30 per cent.), external use. follows : As Anodyne. — Toothache may frequently be relieved by placing a loose pledget of cotton saturated with chloroform between the cheek and the alveolus of the affected tooth. In paroxysms of severe pain it may be inhaled cautiously; in labor, to lessen the severity of the pains during the expulsive period. Its use as an anodyne calls for discretion and the avoidance of every possibility of overdosage. It should always be given by a physician or under his direction, for it is not safe for a person to inhale this drug by his own administration. ^4^ Antispasmodic. — To relieve infantile convulsions, acute paroxysms of asthma, uremic and puerperal convulsions. In these conditions it should never be employed except with competent medical supervision. .4^ Irritant. — It may be used as a counterirritant in case of neuralgia or other localized pain. The effect will vary from mild irritation to the production of a blister, according to duration of the application. If the vapor be completely confined, as by placing the drug upon cotton and covering with a thimble, a small blister ("thimble blister") is quickly produced. As AN Anesthetic, in spite of its long history and earlier extensive use, chloroform today holds a secondary place, because of its dangers. It is much pleasanter to inhale than is ether and a smaller quantity is required, which advantages make it the agent of choice with young children, who seem to be less susceptible to its poisonous action. But the prevailing opinion today is that the use of chloroform with adults is hardly justifiable, except in selected cases. The danger from this agent depends upon its poisonous action upon the heart. Two facts furnish the basis of this danger: 1. It has long been held that chloroform is a direct heart poison, depressing its action greatly and being capable of causing fatty degeneration of its structure. These effects are probably in direct proportion to the amoinit or concentration of the drug. form even in small amount affects the heart peculiarly,'^ rendering it irritable to accelerator impressions in a way that may cause irregularity, fibrillation and sudden death. This effect is not likely to occur during complete anesthesia, when exciting impulses are blocked. Here we have a new explanation of the cases of sudden death under chloroform, that occur when least expected and apparently unprovoked, i. e., before anesthesia is complete or during recovery from the anesthesia. Intermittent administration has also proved dangerous. Le^yf concludes that the "subject of light chloroform anesthesia requires very serious attention" and as a precaution "the first principles are to keep the patient /i/% anesthetized and to make the adminidration continuous.'' He argues against the idea of overdosage in these cases and advocates the use of higher percentages, temporarily, when necessary (3.5 to 4 per cent, of chloroform vapor). There should be no disturbance of the patient during induction of, or during recovery from, chloroform anesthesia and the operation should not begin until anesthesia is complete. To make an incision with reflexes acti^-e is considered hazardous. Administration — The conclusion is clear that the use of chloroform should not be resorted to lightly and that, when employed, administration should be by an expert. Because of its depressant effect upon the heart, it should be given only with patient in the recumbent posture. This being usually impossible in dental operations furnishes additional reason for its non-employment. Chloroform should be given largely diluted with air, from an inhaler that cannot fit closely enough to exclude air. A convenient and simple one consists of a wire form four inches in diameter with a concavity to prevent contact with the nose. This is covered with a few layers of gauze, upon which the chloroform is dropped in small quantities (ten to twelve drops) frequently, or drop by drop more continuously (see Fig. 7). * It has been found that under chloroform anesthesia the heart exhibits an irritahility which may respond to certain exciting causes in a most pecuhar way, e. g., experiments upon cats vmder chloroform showed a remarkable development of irregularity of ventricles upon intravenous injection of adrenahn. The ventxicles beat rapidly and irregiilarly, exhibiting the condition kno-rni as ventricular fibrillation. This action is more intense if the chloroform is diminished so as to allow the corneal reflex to return, and the result then is usually fatal, the heart stopping suddenly after a period of irregularity. It is beUeved that accelerator impulses, from the central nervous system or reflexly through irritation of sensorj' nerves, maj" similarly influence the heart under chloroform. This would account for the cases of sudden death occurring early in the administration of chloroform. Le\w, "Cardiac Fibrillation and Chloroform Syncope," Am. Year Book of Anesthesia, 1915. The inspired air should not usually contain more than 2 per cent, of the vapor of chloroform. This is in accordance with the conclusions of the Special British Chloroform Committee,* to the effect that 1 to 2 per cent, of chloroform in the air is sufficient for anesthesia, and that these proportions are safe; 0.5 per cent, is inefficient, while 5 per cent, is dangerous. frame covered with a piece of flannel or gauze. ^thylis Chloridum, — Ethyl Chloride [C2H/I]. — This drug is prepared by the action of hydrochloric acid gas upon absolute alcohol. It is a very volatile, colorless liquid, having an agreeable odor and burning taste. It is very soluble in alcohol, but only slightly in water. Its most distinctive property is its low boiling-point (55° F.). Vaporizing rapidly at ordinary temperature, it is our most valuable and convenient refrigerant analgesic. The vapor is very inflammable, therefore it should not be used near a flame. As a general anesthetic, ethyl chloride has been in use for a number of years, both as preliminary to ether, and used alone to induce transient anesthesia. It ranks with nitrous oxide as to rapid and transient action, but it is not destined to become popular because of its dangers. While its relative safety among anesthetics has not yet been definitely fixed by accumulated statistics, experience thus far places it below ether. In this respect it must, for the present, be classed with chloroform. MTHYLIS CHLORIDUM 209 An early series of 12,436 cases of anesthesia with ethyl chloride gives only one death that was proved to have been due to the drug. That case had a history of alcoholic abuse and the autopsy revealed degeneration of heart and arteries.* McCardief in 2000 cases saw neither asphyxia nor syncope in any case. His estimate later gives one death in 3000 cases. He has collected records of 21 deaths, and states that at least 30 deaths are known to have occurred under ethyl chloride, while several others have occurred from the proprietary mixture called somnoform. in dental cases. In these cases the "closed method" of inhalation is believed to have been commonly employed. This may have contributed an element of danger; for it cannot be too strongly emphasized that, with so powerful agents as chloroform, ethyl chloride and ether, the limitation of air, by use of a closed inhaler or a bag which requires rebreathing of the vaporladen air, adds a danger of auto-intoxication which cannot be ignored. Experiences thus far lead the above author to regard ethyl chloride as a substitute for ether and chloroform rather than for nitrous oxide, though in children under eight it is usually to be preferred to nitrous oxide. It is to be used with caution in dental cases, and the recumbent posture is advised. Its depressant action is more evident upon the respiration than upon the circulation. When inhaled pure, without access of air, it causes death by paralyzing respiration. In 1000 cases by Waret he noted 6 cases of serious danger, all of which were due to interference with respiration and all recovered under the use of artificial respiration. The same writer, after much experience, adapts the rubber mouth-piece of the nitrous oxide inhaler to ethyl chloride (Fig. 8), as here described in his own words :§ meshed gauze over the end of the tube b, which is then held taut by being forced into the neck c of the funnel-shaped rubber mouth-piece a. The gauze can be renewed at will and the whole apparatus, because of its simplicity, easily rendered sterile, a feature devoutly to be wished for in the laughing-gas mask and other kindred devices. The tube h is the channel along which the stream of ethyl chloride is directed against the gauze c, intended, not merely to receive the ethyl chloride, but also by impact to break it into still finer particles. At this point the ethyl chloride, evaporating, expands and is held by the walls of the mouthpiece a and the sides of the tube h, which, therefore, act as a chamber to temporarily limit the vapors. With ethyl chloride administered as described above, with proper admixture of air, anesthesia is induced in about the same time as nitrous oxide requires; the effects correspond very closely to those of the latter as to duration and recovery, but cyanosis is absent throughout. For use in dental practice it may be said that, compared with nitrous oxide, ethyl chloride is more convenient and equally efficient, though less safe and requiring selection of cases and cautious use. Somnoform, a proprietary mixture of ethyl chloride 60 parts, methyl chloride 35 parts, and ethyl bromide 5 parts, presents no advantage over pure ethyl chloride. Several deaths from its use have been reported. Comparative Safety of Anesthetics. — The relative toxicity of these agents must depend largely upon their chemical make-up. If we compare the chemical formuUe of the four leading anesthetics, viz.: Chloroform CHCI3 we note differences that correspond to the increase in toxic power. Nitrous oxide is a very simple compound that has slight effect upon protoplasm. The hydrocarbon compounds have a more decided effect, that of ether being prolonged and profound without much danger from its action upon vital tissues; but with the introduction of a halogen element in combination with the organic radical, we find the harmful action to increase in proportion to the number of halogen atoms in the molecule. Thus, ethyl chloride contains a chlorine atom which makes it more toxic; while chloroform, with three atoms of chlorine is decidedly poisonous to tissues, frequently causing a positive degeneration.* safety for any new anesthetic containing a halogen element. Briefly then, it may be stated for the agents now most employed, that nitrous oxide is the safest anesthetic in ordinary use; next in point of safety is ether, while chloroform and chloride of ethyl remain the least safe. The comparative safety of ether and chloroform, as given in a number of series of statistics, shows some variation, but it may be taken as a fair statement that ether is five times as safe as chloroform. f A very interesting study of this question is that presented by the Committee of the British Medical Association appointed to investigate clinically the safety of the several anesthetics. j They studied 25,920 cases of general anesthesia, all occurring in the United Kingdom in the year 1892. Their conclusions include not simply deaths from anesthetics, but all cases of danger that could be attributed to the agent used. They found that dangerous sjTQptoms occurred: See Am. Year Book of Anesthesia, 1915, p. 150. t In connection with tliis, it is interesting to note the estimate of the comparative anesthetic power of ether and chloroform. It has been stated, as a result of experiments, that "the concentration of ether in serum necessary for complete anesthesia is 1 : 400; of chloroform, 1 : 4500 to 1 : 6000." Cited from Sollmann, American Medicine, September 10, 1904, p. 455. It is conceded that nitrous oxide alone is least dangerous of all. Mixtures of Anesthetics. — Besides the combined use of ether with nitrous oxide or ethyl chloride, mixtures of anesthetics cannot be very strongly advised. The old A. C. E. mixture of alcohol 1 part, chloroform 2 parts, and ether 3 parts is now seldom used. The differences in specific gravity and volatility of the several liquids, make it difficult to know what proportion of each the vapor contains. The Schleich mixtures for general anesthesia are not regarded, in general, with sufficient favor to constitute any recommendation of them. These must not be confused with the solutions for local analgesia, discussed on page 173. Schleich's idea in introducing mixtures of anesthetics for general anesthesia, was to obtain a liquid with a desired boiling-point (at about the temperature of the blood), to secure which he employed mixtures of ether, chloroform and petroleum ether with boiling-points varying between about 100° and 108° F. His belief in the relation between the action of an anesthetic and its boiling-point has not been accepted. to any modification of it. Resuscitation in Danger Cases. — With nitrous oxide, ethyl chloride, ether, and usually with chloroform, the danger is paralysis of respiration. When the condition is simply this, reco\'ery may be expected, with proper treatment. But while the condition is a simple one with the three first-named agents, with chloroform there is always added a serious depression of the heart, and occasionally paraylsis of that organ. When the heart is paralyzed by chloroform its irritability is lost, which * Sollmann (Fliannticolofry, 1906, ]). 4:iG) .states that ethyl bromide "must not be pushed to the disapi)earanfe of reflexes, since the respiration is iJaralyzed about the same time. The zone of safety is, therefore, very narrow." The drug also deteriorates rapidly after exposure to air. RESUSCITATION IN DANGER CASES means death. But absence of the pulse beat must not be at once taken to mean paralysis, for, with the depressant action of the drug upon the heart, its pulsations may have become so feeble as to be imperceptible in the peripheral vessels; and it is not proper to waste time at first to ascertain the heart's condition. The important thing immediately is arti- ficial respiration, which is itself here the best cardiac stimulant, and with its faithful continuance the real condition of the heart will soon appear; for artificial respiration not only supplies oxygen but facilitates the action of the heart, by relieving engorgement of its chambers, each expansion of the lungs favoring the emptying of the right ventricle and each contraction furnishing more blood to the left side of the heart for distri- bution. The invariable treatment, therefore, when respiration ceases, should be artificial respiration with free access of air, preceded, of course, bv withdrawal of the anesthetic. Artificial Respiration. — Sylvester's method of artificial respiration is the one most connnonly employed. Figs. 12 and 13 show the position of patient and attendant. The movements of inspiration and expiration should succeed each other regularly at the rate of from twenty to twentyfive respirations per minute, or once in about three seconds.* In imitation of natural respiration the inspiratory period should be slightly longer than the expiratory. In connection with this method, massage of the heart by an assistant, by pressure during expiration underneath the left ribs and upward toward the heart, so as to press the latter between diaphragm and chest wall, has come to be employed as an important aid in reestablishing the heart's efficiency. It is most effectual in cases where the irrritability of the heart muscle is not much impaired. The Schdfer or Prone-pressure method has gained favor in this country, as being at least as efficient as the Sylvester method and more easily performed by one person, since it requires less muscular exertion. It is carried on as follows: Have patient lying flat, with face downward and turned to side, tongue drawn forward and arms extended above head. Kneel aside, or preferably astride, the patient's thighs. For the expiratory movement place hands upon lower part of chest, thumbs nearly touching and fingers spread out over lower ribs; by a forward movement throw your weight, through your arms, upon patient's chest, thus compressing both chest and abdomen and effectually expelling air from lungs. For the inspiratory movement spring backward, relieving the pressure completely to allow chest to expand, but keeping hands in place. Time the movements to 15 to 20 complete respirations per minute, or by your own respiration — the forward expiratory movement with your expiration and the backward movement with your inspiration. The Howard method of artificial respiration also is convenient and useful. It is described as follows :t "The patient is turned upon his back, and a bolster of clothing or of other material is placed under him so as to throw his epigastrium forward. His wrists are crossed behind his head and held in that position. His tongue is drawn forward and held with a dry handkerchief in the extreme corner of his mouth. The operator now kneels astride the patient's hips, ' resting the ball of each thumb upon the corresponding costoxiphoid ligaments, the fingers * The average normal rate of respiration is about eighteen per minute, but as the need of aeration is urgent, and as artificial respiration is apt to be less efficient than the normal function, it is well to exceed the normal rate sUghtly. ARTIFICIAL RESPIRATION falling naturally into the lower intercostal spaces. Resting his elbow against his sides and using his knees as a pivot, he throws his whole weight slowly and steadily forward until his mouth nearly touches the mouth of the patient, and while he might slowly count one, two, three; then suddenly, by a final push, springs himself back into his first erect position on his knees; he remains there while he might slowly count one, two, then repeats, and so on about eight or ten times in a minute." The Laborde method of rhi^lbmic traction upon the tongue may be used as a stimulant to respiratory movements when there is any possibility of response, the tongue being grasped by the fingers over a drj' napkin, or by a tenaculum or forceps, and drawn forcibly forward at intervals of about four seconds. Laborde holds that this measm-e excites reflexly the movements of the diaphragm especially. poisoning. Medicinal Teeatmext. — While artificial respiration must be kept up until natural respiration is restored, or until the hopelessness of the case has been absolutely established, an assistant must keep note of pulse and give respiratory and cardiac stimulants hypodermically, as required. The same medicinal treatment will be indicated here as in poisoning by cocaine, being careful to avoid vasodilators, especially where the arterial pressure is greatly reduced. (See Plate IV, p. 177.) Strychnine^ atropine, caffeine and digitalis, therefore, will be the drugs indicated, the last named being less needed in cases of simple asphyxia. Meanwhile, the so-called diffusible stimulants, such as ammonia by inlialation, or aromatic spirit of ammonia by the mouth (y-1 teaspoonful (2-4 mils) if swallowing is possible, may be given. [The suprarenal preparations (adrenalin, etc.), would usually be classed with these arterial stimulants; but in case of danger from chloroform they would be absolutely contra-indicated, because of their peculiar and dangerous effect upon the heart under chloroform. (See p. 207, note.)] Alcohol. — Ethylic Alcohol. — Spiritus Vini liectificatns [C2H6O.] (For preparations and doses, see Index of Drugs.) In alcohol we have an anesthetic agent that is practically not used as such. It has been commonly regarded as a stimulant, but a study of its full action, compared with that of ether and chloroform, must convince one of a real similarity, approaching an identity, in their effects. ^Yhatever of stimulant effect it induces seems to be secondary to its local irritant action; in this respect it resembles ether. Its full anesthetic effect is so slowly produced and persists so long and is attended with such unpleasant symptoms (those of drunkenness), that it cannot ordinarily be used as an anesthetic. That it is a poison cannot be questioned. That it is capable of acting as a food is in accordance with the teaching of most authorities, but it cannot be regarded as an economical food in health. Its precise action after absorption into the blood is not fully understood, except that in large doses it is anesthetic and poisonous. This latter fact should form the basis of a positive rule that alcohol should not be given in dangerous narcosis from ether or chloroform. It can only be admissible as a reflex stimulant, or as present in the aromatic spirit of ammonia or in other irritating diffusible stimulants. (The diagrams of Plate VIII are intended to show the present status of knowledge concerning the internal influence of alcohol.) fluence of a small dose. Two diagrams are here presented : Diagi-am A represents the action of a small dose as taught by those who liold that its primai'y influence digestion. Many observers deny the primary stimulant action, holding that the drug is a depressant from the first, or even in small dose. Tiie excitement of intoxication is not due to Btimulation, but to depression of the higher controlling centers. Local action.' Irritant, by reason of its affinity for water. When applied to the mucous membrane of the digestive tract, the ivi-itatiou probably induces reflex stimulation, which may account in part for the primary stimulant effect attributed to the drug. Diycsiion. In small doses, well diluted, alcoliol seems to increa gastric secretion and motility, wliile stronger solutions (5 per cent, or more) retard tbe digestiv -Is IX food the position of alcohol has not been very definitely determined. A small part only can be recovered as alcohol from the fluids of excretion. The gi-eater part therefoi-e is changed into other products, and is believed thereby to tribute some energy to the body. The economy to the system of its use may be open to question. STIMULANTS. A STIMULANT IS usually defined to be an agent that increases the activity of an organic function or process. But in the application of the principle of stimulation, a qualification of this definition should be noticed. We seek not simply to secure rapidity, but always efficiency of a function. Thus, in the majority of cases that call for a heart stimulant the heart's action is already rapid, and our most powerful stimulants, such as digitalis, in their full action actually slow the pulsations of the heart; but in spite of this the efficiency of the contraction is increased by them and the pulse improved in character. Again, the efficiency of a function may be lessened by undue inhibitory restraint. Here a stimulant result would require that the inhibitory influence be weakened. Belladonna acts in such manner, allowing the heart to beat more rapidly by depressing the inhibitory vagus nerve endings. Having in mind, therefore, the real object of stimulation, i. e., to secure efficiency of a function, we may employ agents that act in various ways, but always toward the same object. Direct stimidants have their action directly upon the organ or tissue sought to be influenced. Their action may be to increase nervous, muscular or secretory activity. Such an agent might be called a kinetic stimulant, in that it changes latent into active energy. This increase of activity is at the expense of the reserve energy of the organ, and tends toward its exhaustion. This is an important consideration in the choice of a stimulant, and, indeed, in the decision whether any stimulant shall be employed, for the rapid exhaustion of the reserve power of an organ may defeat the object of our stimulation. There are some stimulants, however, to which this objection scarcely applies — those that simply increase the irritability of nerve or muscle without calling forth any increase of activity, except in response to normal stimuli. These might be called potential stimulants, in that they increase the possibility of activity in response to normal stimuli. They do not tend particularly toward exhaustion of an organ. Strychnine is nerve centers. Indirect stinmlants produce the stimulant result secondarily. Some of these act primarily by removing inhibitory influence and others by causing an irritation of sensory nerves. An example of the former is the belladonna action, noted above, which primarily lessens the inhibitory influence of the vagus upon the heart, and thereby allows the heart to beat more rapidly, which is the secondary or indirect stimulant eflFect. Examples of the latter are ammonia, alcohol and ether, which are locally irritating to mucous membranes. By irritating sensory nerve endings, they induce a reflex or indirect stimulant effect. vulsions. (Because of the sensitiveness of the system in childhood, children do not bear stimulants as well as sedatives. They need stimulation less often than do older persons, and the response to stimulants is usually prompt.) The Indication for Employing Stimulants is, in general, any depression of a function to a degree that may be regarded as below the yhysiologic minimum of its activity. ^Ye recognize that every organ has a certain range of action that may be called physiologic, within which it reacts to the work demanded of it, by increasing or lessening its activity. Functional activity, therefore, is a variable quantity, based upon the strength and nutritive resources of an organ, which are opposed by the amount of work imposed upon it. The physiologic minimum of activity, therefore, must vary as modified by these factors; but it may be defined to be the minimum of efficiency of a function under existing conditions. Now as long as an organ is working efficiently within its physiologic range it needs no stimulation. But when, either from its own inability or from excessive demands made upon it, its activity falls below its physiologic minimum, then stimulation may be employed to compel an extra expenditure of energy in enforced activity. It is observed, moreover, that normally acting organs do not show much response to stimulants, but that those whose action is deficient respond well. When an organ is doing all the work that is required of it, it is difficult to force its action; but when the need of doing more work is present and a stimulant is applied, there appears to be a cooperation of factors, the increased irritability or the more fowerfnl iminession contributed by the applied stimulant enabling the organ to respond to the need of increased work, which, after all, is its normal stimulus. Thus defined and limited, stimulants form a very important and indispensable class of remedies — the kinetic stimulants to serve as emergency remedies to tide an organ over a critical period, and the 'potential class to forestall failure of its function. Closely related to the latter are the agents usually classed as tonics, which may supply elements to the tissues or conserve the expenditure of energy by the cells. The indirect stimulants that produce a prompt circulatory effect have been termed diffusible stimulants. They are diffusible in effect rather than in action. Their action is mostly a reflex one, following local irritation of the sensory nerves in the mucous membrane. Their effects are usually transient. Alcohol fethylic). — The local action of this drug is fully considered in the chapter on Astringents; but the secondary effects arising from the marked irritation that attends its abstraction of water from the tissues and its coagulation of albumin, are those that may be called stimulant. They are reflex in nature, and are similar to the reflex effects following irritation of any sensory nerve. Alcohol should be used in a strength of not less than 50 per cent., in order to obtain the stimulant effect, which at best is slight and transient. It may be used either diluted or in the form of whisky or brandy. Pharmacologic experiments upon dogs do not prove alcohol to be a stimulant after its entrance into the circulation; there may be a slight temporary increase of pulse-rate^ but arterial pressure is not raised. On the whole, alcohol must rank as a rather feeble reflex stimulant, whose effect is uncertain and brief, and requiring, for continued effect, repeated doses that may later cause depression. For a single, prompt stimulant result, as in case of faintness, it is often useful. It should be remarked that what is popularly regarded as stimulation by alcohol, i. e., the hilarity, activity and talkativeness, are not stimulant effects at all, but rather the opposite. They correspond to the period of disturbed or imperfect consciousness common to anesthetics, and must be regarded as uncontrolled activity of the lower emotional and reflex centers, which occurs because the controlling function of the cerebrum has been depressed. In large doses alcohol soon produces its characteristic depression of the whole central nervous system, while its continued use leads to degenerative changes in the arterial system, kidneys, liver and other highly vascular organs. 220 STIMULANTS AXD TOXICS ^ther. — Ether. — This drug is fully considered in the chapter on Anesthetics. Its stimulant secondary effects, following primary irritation, are similar to those of alcohol. It is used in the following preparations : Spiritus .ffitheris Compositus. — Compound Spirit of Ether. — Hoffman's Anodyne (contains 325 parts of ether, 650 parts of alcohol and 25 parts of ethereal oil. Not official.) Dose f3 1 (4 mils). These preparations are given mostly by the stomach. Ilypodermically they are quite irritating, although this should not prevent their use in emergency, if swallowing is difficult or impossible. Indeed, the greater irritation would likely induce greater reflex stimtdation. Ammonia [XII3]. — (For all preparations see Index of Drugs.) This substance has a decidedly irritant local action, and has the advantage of being a gas, which permits of inhalation. It is so volatile that it is always employed in solution, even for inhalation. In fact, the aqua ammonice fortior liberates the gas so rapidly as to be caustic in action, and is therefore not to he employed in any way as a stimulant, unless first diluted. The following preparations are commonly employed: The aromatic spirit of ammonia is the best one of this class of stimulants for stomach administration. Its stimulant action is of longer duration because of the gradual decomposition of the ammonium carbonate, which thus liberates ammonia gas for some time. All ammonia preparations deteriorate with keeping unless kept tightly corked. Of the salts of ammonium the carbonate is a valuable stimulant. Various other volatile substances ha\e a more or less direct stimulant action, the reflex factor being much less because they are less irritating. The volatile oils and substances related to them belong to this class. A few only among them are important enough to be employed. * Aromatic spirit of ammonia contains: Water of ammonia, 9 per cent.; carbonate of ammonium, 3.4 per cent., and small quantities of oils of lemon, lavender and nutmeg, with alcohol, 70 per cent. These are stimulating to the central nervous system and to the heart. In large doses they may depress. Locally some are irritating, while others are sedative. They are much used internally as carminatives, i. e., agents that relieve colic and cause expulsion of gas by relieving spasmodic contraction of the intestines. Camphora. — Camphok [doHieO]. — Average dose gr. 3 (0.2 gm.). A ketone derived from Cinnamomun camphora. It occurs in white, translucent, crystalline masses, which are soluble in alcohol, ether, chloroform, and oils, but almost insoluble in water. It has a strong odor and sharp aromatic taste. It is tough, but may be pow^dered in the presence of a little alcohol. (For preparations and doses, see Index of Drugs.) Locally, camphor preparations are sedative except for the alcohol present as the solvent. Internally, it is a general stimulant to the nervous system and heart, but in large doses it may depress the brain, so as to cause delirium or convulsions. The spirit may be inhaled in syncope or faintness. For internal use as a stimulant, camphor has acquired a place of first importance in the treatment of circulatory depression. It is given hypodermically, dissolved in a sterile fixed oil. For local application certain combinations which modify the action of camphor are sometimes used. The basis for these is the fact that when camphor is triturated with either phenol, chloral hydrate, menthol or thymol, the mixture becomes liquid and is suitable for external use. Of these. Camphorated phenol (Camphophenique) and Camphorated chloral are most frequently employed. Oleum Menthse Piperitse. — Oil of Peppermint. — Average dose, lU 3 (0.2 mil). This is used mostly as a carminative, either in form of the spirit, or combined with cathartics to prevent griping. The local effect is sedative. Heat. — The stimulant effect of heat is made use of in various ways. In case of shock or collapse a hot-water bag placed directly over the heart, or heat applied to the extremities, will be found useful. Copious injections of very warm water, or preferably warm normal salt solution, into the rectum and colon, is a very excellent means of stimulation by heat. The restorative value of the salt is also here apparent. hypodermoclysis, or intravenously, should be regarded today as one of the most important means of stimulation. It is rather restoration, by a fluid corresponding closely in salinity to the blood serum, which may be deficient or improperly distributed. Loss of blood by hemorrhage or loss of serum by a serous diarrhea, would especially indicate the use of saline solution. It is also useful in any condition of extreme depression. In severe cases of typhoid fever and other exhausting diseases, the patient is oftentimes tided over a critical period which might otherwise be fatal, by the daily use of one to four pints of normal salt solution hypodermically. The solution is prepared quite hot and allowed to run slowly through a large-sized, long hypodermic needle from a fountain syringe into the lumbar region or underneath the breast. Other stimulants may be added to the solution. Belladonnce Folia. BelladonnoB Radix. — This drug holds a unique place as being a central stimulant and peripheral depressant to the nervous system. Either the alkaloid atropine or the tincture of belladonna may be used as a respiratory and cardiac stimulant, atropine being always preferred for hypodermic use. But this drug must be regarded as a second-rate stimulant, and care must be taken not to exceed the physiologic limit, as it may then be disturbing or narcotic in effect. Locally applied, belladonna is anodyne, acting by depressing sensory nerve endings. It is used to allay local pain or irritation, as in neuralgia, for which purpose the plaster, ointment, or liniment of belladonna, or the oleate of atropine may be applied. (For preparations and doses, see Index of Drugs.) Atropine in aqueous solution is dropped into the eye to dilate the pupil and to paralyze accommodation. Any preparation of belladonna or atropine promptly checks the excessive flow of saliva in mercurialism, for the treatment of which symptom it is our best agent. Sweating is also diminished by this drug, as are also various other secretions of the body. In checking secretion the drug acts by paralyzing the secretory nerve terminals within the glands. Physiologic action : In general, '' atropine acts as a stimulant to the central nervous system and paralyzes the terminations of a number of the nerves, more especially of those that supply involuntary muscle, secretory glands and the heart." [Cushny.] It paralyzes peripheral inhibition. It decreases the secretions generally, except the urine, and increases the body tempeiuture, producing a condition simulating fever. Nervous System. Brain. Stimulates the cerebrum, especially in its motor areas. Medulla. Stimulates respiratory center. Spinal cord. Depresses inhibitory centei-s. Motor. Depresses motor nerves. Secretory. Paralyzes the endings of many of the secretory nerves, censing a diminution or arrest of the secretion ; hence there result dryness of the mouth, le.ssened secretion of gastric and pancreatic jiiices and of milk. The sweat glands are rendered less active. Vagus. Paralyzes the inhibitory terminations of the vagus within the heart, and the secretory terminations withm the digestive system. Muscular System. Depresses unstiiped muscle, but has no influence upon voluntary muscle. Lessens the movements of stomach, intestines, bladder, uterus, and in general the organs containing unstriped muscle, except the arterial walls. [Cushny.] Eye. Pupils are dilated by paralysis of terminals of the motor oculi nerve in the iris, whereby it paralyzes accommodation also. Most authorities state that it increases intraocular pressure. tion of the pulse. Capillary area. Tends to contract arterioles by stimulation of vasomotor center in the medulla, but this action is largely neutrallized by dilatation of the systemic arterioles by peripheral action. Excretion. Kidneys. Stimulates excretory function, both of the glomeruli and the renal epithelium, causing increase of water and of solids, the increase of water being more marked. The diuretic effect may be prevented by the vasomotor action. cardiac ganglia, or both. Capillary area. The splanchnic arterioles may be contracted by its action upon vasomotor centers, but the cutaneous and muscular vessels tend to dilate. Excretion. Eliminated by the kidneys, appearing soon after absorption, partly unchanged and partly changed. Contraction of renal vessels may hinder its elimination. Homatropinse Hydrobromidum, an artificial alkaloid, is used as a mydriatic, producing a more rapid and more transient dilatation of the pupil than does atropine. It is used locally. (See Index of Drugs.) Obtained from Hyoscyamus and other Solanacece. Used as sedative. Scopolaminae Hydrobromidum (Hyoscinse Hydrobromidum), average dose gr. 2-^0" (0.0003 gm.). Obtained from Hyoscyamus leaves, Scopola root and other Solanaceoe. This is less stimulating than atropine; in fact, is used only as hj^notic and sedative. (See Index of Drugs.) Caffeina Citrata. — Citrated Caffeine. — Average dose, gr. 5 (0.30 gm.). This alkaloid, obtained from tea and coffee, has an important use as a heart and cerebral stimulant and as a diuretic. It is entirely safe to be used in large doses, therefore it is one of the best stimulants to employ in poisoning by narcotics. The citrated caffeine is the preparation usually employed, because more soluble than caffeine. (See note on p. 177.) CaflEeinae Sodio-Benzoas. — Caffeine Sodio-benzoate. — Average dose by mouth, gr. 5 (0.30 gm.). hj-podermic, gr. 3 (0.20 gm.). This is the best salt of caffeine for hypodermic use, because of its free solubility in water, being soluble in 1.1 parts. Theobromine (from Theobroma cacao and from Guarana) has an action upon the circulation similar to that of caffeine, but is superior as a diuretic, and less stimulating to the cerebrum. (Not official.) This drug easily ranks as one of the very best general stimulants. In large doses it is poisonous, but it is not narcotic, therefore it can be pushed to its physiologic limit with less danger than is the case with belladonna. It increases the irritability of nerve centers to normal stimuli, and does not tend directly to exhaustion. It is a valuable respiratory stimulant by action upon the centers. In all conditions of general depression, cardiac weakness, in infectious diseases, pneumonia, typhoid fever, in poisoning by cocaine, opium and other narcotics, it is useful. It is also used as a bitter, stomachic tonic. Digitalis is used whenever the heart is unequal to its task, by reason of dilatation or simple weakness. When extensive fatty degeneration is present, and in certain valvular defects, it is not the drug of choice, but may be required. As it "whips up" the heart to greater exertion, its use should be discontinued as soon as possible, so as to avoid exhaustion of the organ. It should be regarded as an emergencii drug in cardiac diseases. It is a great mistake to suppose that digitalis is needed in every case of valvular disease; for when any cardiac disease is fully compensated, and in simple hypertrophy, digitalis should not be used. When arterial pressure is high the drug is not indicated. In these conditions the drug may do harm. The tincture and the infusion are the preparations mostly employed. In emergency the tincture may be used hypodermically in full dose. The drug acts slowly, and it therefore cannot be relied upon alone as an emergency stimulant. The nitrites are indicated in conditions of high arterial pressure, due to disease of the arteries or constriction of arterioles. They cannot be regarrled as direct heart stimulants of any decided power, but they act in an equivalent way, by reducing the work of the heart through dilating the arterioles. In this way the resistance against which the heart has to force the blood is largely removed, and at the same time its action is accelerated, so that a freer capillary supply results. Nitrites should not l)e used in conditions of low arterial pressure. Nitroglycerin in tablet form, or its 1 per cent, solution {Spiritus Glyceryl is Nitmtis) is Circulation. Gives greater force and rapidity to arterial current. Heart. Stimulates the inhibitory influence (vagus, center), which slows the heart and tends toward relaxation. Stimulates the cardiac muscle and contained ganglia, giving greater force to the contractions. Capillary area. No direct action in therapeutic doses. With improved circulation in the brain, from the heart stimulant effect, relaxation of arterioles occurs which prevents any great increase of blood pressure. Kidneys. Direct action upon the renal epithelium is uncertain. The urine is increased, but mainly through the influence of an improved circulation. eral drugs of this group is rery similar, Amyl Nitrite (by inhalation) has the most rapid and transient effect, Nitroglycerin is most powerful, and Sodium Nitrite has the most permanent etiect. Heart. Any direct action upon the heart is doubtful. The acceleration is due mainly to depression of the vagus center through lessened blood pressure. Capillary area. DUates arterioles and veins, thereby increasing the volume and efficiency of the capillary circulation; vessels of face and abdominal organs are most affected. The red color indicates the stimulant effects of the nitrites ; the blue color indicates their depressant action upon the vagus center, which is the chief cause of the increase in pulse rate. nitrites. It is not necessary to give nitrites h\-podermically, as the effect of AiViYL NITRITE may be obtained almost instantly by inhalation, and a tablet of nitroglycerin placed under the tongue will produce its effect in from tlii'ee to five minutes. Its action also completely disappears in from thirty to sixty minutes. "When the drug is really indicated it may be given every hoiu" for several doses if necessary, or the dose may be increased as needed. is desired. In conditions that are believed to be due to arterial spasm or constriction, as angina pectoris and asthma, the nitrites are useful for temporary relief; and in arteriosclerosis they sometimes constitute the principal medicinal treatment. There is no doubt that the value of the nitrites was earlier overestimated. Upon the plain indications mentioned above they occupy a place of usefulness that is their own, no other drugs being comparable to them; but it was unfortunate that the belief became current that they were direct heart stimulants. For, with this belief as a basis, they were used in such diseases as pnemnonia and other acute infectious diseases, when the blood pressm-e was already too low to allow efficiency of circulation, and in cases of chloroform narcosis, where the same condition prevailed. In fact, it was the practice of some, the more cardiac stimulation was needed, the more to resort to the nitrites; while it is true in the main that the more cardiac stimulation is needed the less are the nitrites indicated. The nitrites should be viewed as vasodilators, not as heart stimulants. But in their action as vasodilators they may be regarded as circulatory stimulants. The capillary area fed by the arterioles is, after all, the most important part of the circulation, for it is there, in the cells of the tissues, that all nutritive changes occur and all functional activity is maintained. In conditions of high arterial pressure, the blood supply to the capillaries is often lessened by the tendency to constriction of the arterioles. The nitrites, by dilating the arterioles, will increase the blood supply to the capillary area and furnish better nutritive materials for cell activity — a true circulatory stimulation, but not heart stimulation. TONICS. Tonics are frequently defined as permanent stimulants. This conveys the idea of permanency of result which always pertains to the class, but we must note that tonics may not have any proper stimulating action. It is difficult to form a definition that will include all remedies of the class, because of the wide dift'erence in their nature and action. Their chief value is in relation to the reserve energy of organs, which they conserve by supplying the necessary materials for tissue renovation and for the production of energy, or by otherwise promoting nutrition. Iron is classed as a restorative tonic for the reason that it supplies a normal constituent to the blood and tissues. The ordinary foods hold a similar place and must be regarded as tonics in the sense that they restore needed material. On the other hand, bathing and massage will promote the general nutrition of the body, and are, therefore, tonic remedies. The simple bitters, such as gentian, taken into the stomach, stimulate the digestive functions and thus indirectly promote general nutrition, Nutritional Tonics. Among the class of nutritional tonics — i. e., those that promote the general processes of nutrition^ — are those that act by increasing the activity of digestion. These are known as stomachic tonics or simple bitters. Their chief characteristic is their bitterness, by which they seem to stimulate, possibly through primary irritation, the mucous membrane and secretory glands of the stomach. The immediate result of their presence in the stomach is to retard or lessen secretion, but this is soon succeeded by an increase of secretion, so that the full eftect, obtained fifteen to thirty minutes after administration, is an increase of gastric juice and of motility of the stomach. They should be given before meals so that their full action may be secured in time for the beginning of stomach digestion. The chief agents of this character are here given. (For preparations and doses, see Index of Drugs.) Of any of these the tincture (in case of gentian the compound tincture) is a leading preparation and may be given, in case of each, in a dose of f5 l-l (1-4 mils). The infusion of quassia is easily prepared with cold water, and may be given freely. To this group of simple bitters must be added several other drugs that are equally efficient as stomachics, but whose more important action gives them a larger place. They are sometimes called: Peculiar Bitters. Cinchona. — Peruvian Bark. — ^The bark of a number of species of cinchona. It contains quinine and many other alkaloids. (For preparations and doses, see Index of Drugs.) Quinine represents the drug fully. (For its combinations and doses, see Index of Drugs.) Besides being a bitter tonic, quinine is an efficient antiseptic, but its bitterness prevents its extensive internal use as such; although it is sometimes employed as an intestinal antiseptic, given by stomach or injected into the colon. Its most valuable and distinctive use is in malarial fever (fever and ague), in which disease it is a specific, preventing in the blood the growth of the plasmodium malarise, upon which the disease depends. This must be regarded as a true antiseptic action, obtained after absorption of the drug, which for this purpose is given in full dose of 15 to 30 grains (1-2 gm.) daily, in single or divided doses. A favorite method is to give 15 grains (1 gm.) in one dose daily, about three hours before the expected paroxysm. The average tonic dose of a quinine salt is gr. 1\| (0.1 gm.), before each meal. A form of supra-orbital neuralgia supposed to be of malarial origin, known as hroiv ague, which presents the periodic character of malarial fever, in that it occurs at about the same hour each day, or every second day, continues with severity for some hours and then disappears, is promptly relieved by a full dose of quinine daily, three hours before the usual time of its onset. Quinine sulphate is the salt mostly employed, but it is only slightly soluble in water, except when an acid is added. The bisulphate is freely soluble. With the giving of large doses of quinine there occur the evidences of saturation, that are known as cinchonism. Ringing in the ears and fulness of the head are the symptoms of this condition, which is not serious, but passes away soon after cessation of the drug. Quinine action and its hmitations were understood. Nux Vomica. — The seeds of Strychnos Nux-vomica, containing not less than 2.25 per cent, of alkaloids. (For preparations and doses, see Index of Drugs.) The chief alkaloid, strychnine, has been fully considered as a stimulant. It is valuable also as a bitter tonic, as are the preparations of nux vomica. All preparations are intensely and persistently bitter. The special value of this drug, in its general tonic use, lies in the fact that, after its local effect in the stomach, its absorption is followed by a general increase in the activity of all reflexes, through its action upon ner^•e centers of reflex action. This is the effect that pertains to the action of the alkaloid strychnine in its use as a stimulant. The tincture of nux vomica is the preparation most commonly used as a bitter tonic. In large doses the drug is poisonous, causing very characteristic tonic convulsions which affect chiefly the muscles whose nerve supply is directly from the spinal cord. (See Table of Poisons and Antidotes.) Prunus Virginiana. — Wild Cherry. — The bark of Pntnus serotina, gathered in the autumn. (For preparations and doses, see Index of Drugs.) In addition to its action as a stomachic tonic, this drug possesses decided sedative properties, which are due to the presence of hydrocyanic acid in its preparations. This substance does not exist in the crude drug, but is developed when the latter is treated with cold water. By a reaction between two constituents, amygdalin and emuhm, a volatile oil identical with oil of bitter almond is formed. This contains hydrocyanic acid. Wild cherry finds its special use where a general or local ner^'e sedative is indicated, in connection with a stomachic tonic. In cough mixtures its preparations fill a useful place. Its local sedative and tonic effects make it a remedy that is applicable in irritable conditions of the stomach, to control vomiting and improve digestion. Restorative Tonics. This class comprises both the ordinary food substances, that supply material for tissue reconstruction and energy production, and the medicinal agents that are really foods in the sense that they are necessary to the tissues. Passing the ordinary food substances with the simple mention of oxygen, water, starchy, fatty and nitrogenous foods and sodium chloride, our chief consideration will be gi^'en to the restoratives ordinarily regarded as me(ficines. Inasmuch as they aid chiefly by restoring some element that is lacking, their precise action requires no extended dis- drug in order to pleasant administration and ready assimilation. Ferrum. — Iron [Fe]. — (For preparations, their reactions and doses, see Index of Drugs.) This metal is commonly employed either in its pure form of reduced iron or in one of its many combinations. The large number of these supply every need of form, and of adaptability to the various conditions that call for its use. Those most frequently used are ferrum reductum, massa ferri carbonatis, ferri pjTophosphas, tinctura ferri chloridi, and s}Tupus ferri iodidi. The last-named is alterative as well as restorative, and a most useful agent in the treatment of so-called scrofulous conditions in children. Besides these preparations the great variety of compound salts find special uses. Ferri hydroxidum, or ferric hydrate, is the most useful chemical antidote to arsenic. The real systemic action of iron is mainly in the blood, and, whatever salt or combination is employed, the iron is believed to be changed to the chloride before absorption. It furnishes material for the coloring matter of the red cells, therefore it is especially indicated where there is deficiency of hemoglobin (chlorosis). It should be insisted upon that it is unnecessary to use the new and largely advertised preparations of iron. As a rule they are expensive, and they are not at all superior to the older, well-known, official forms. The reaction of iron salts should be noticed, and for prolonged use those that are neutral selected by preference, so as to avoid damage to the teeth. Only those that have an acid reaction can affect the tooth structure, but staining may follow the use of any preparation in a mouth that is not kept scrupulously clean. This stain, which is usually sulphide of iron, may be easily removed from the surface of the enamel, but in a cavity it may be more permanent. The tinctm'e of the chloride is one of the strongly acid preparations that must be used with care. Its contact with the teeth may be limited by taking it through a glass tube, but a more positive safeguard is to ensure neutralization of the acid by rinsing the mouth, before and after taking, with a solution of sodium bicarbonate or other alkali. Mineral Acids. — These are used internally only in the dilute form. Even then they should be further diluted, and the same precautions taken to protect the teeth as are mentioned above. cent, by weight of absohite sulphuric acid. Acidum Sulphuricum Aromaticum. — ^Aromatic Sulphuric Acid. — 20 per cent, by weight (or about 10 per cent, by volume) of absolute sulphuric acid in nearly pure alcohol. The average dose of either of these isTTl 15 (1 mil). They are given after meals, as a rule. A very important use of dilute hydrochloric acid is to restore the quality of the gastric juice when its acid is deficient. It being the normal acid of this digestive fluid, its administration furnishes one of the most typical instances of restorative treatment. It is not easy to explain the action of vegetable acids upon the ground of supplying normal elements that are lacking in the system. But their use is established by long clinical experience in certain conditions of disturbed nutrition that follow prolonged abstinence from fresh foods, as with sailors upon long sea voyages. The disease induced is known as scurvy, and it seems to present an altered or depraved condition of the blood as its chief pathology. Upon the skin and mucous membranes more or less extensive spots of ecch\Tnosis occur, the particular kind of lesion being known as purpura. The abnormal condition of blood is usually promptly removed, with full return of health, by a free supply of fresh fruits, vegetables, and meats. Citric acid, alone or as present in the juice of lemons or limes, is a valuable addition to the dietetic treatment of scurvy. Orange-juice is likewise added to the diet of infants fed upon sterilized or pasteurized milk. Tartaric acid is used simply as a substitute for citric acid. Phosphorus [P]. — (For preparations and doses, see Index of Drugs.) This substance is of the greatest importance to the system, in its capacity as a restorative. Among other effects of its prolonged use, it has been shown to have the power of inducing more rapid growth of bone, as was found to result in experiments upon animals.* Accordingly, it may be of service in delayed dentition and in rachitis; but, owing to the very disagreeable taste of pure phosphorus, we usually have to be content with the use of phosphates, hypophosphites and dilute phos- phoric acid. The most common form of pure phosphorus for administration is the official pill containing ^qq of a grain (0.0006 gm.). It is particularly indicated in certain diseases of the nervous system and in conditions of deficient bone nutrition. Acidum Phosphoricum Dilutum. — Diluted Phosphoric Acid. — 10 per cent. This acid is used as a general nerve tonic and substitute for phosphorus. Average doselU 30 (2 mils). The hypophosphites are useful, both as substitutes for phosphorus and as furnishing combinations of the drug that may be more easily appropriated by the system. They are certainly less unpleasant to take. They are largely used in rachitis, in wasting diseases such as tuberculosis, and in diseases of the blood and of the nervous system. Massachusetts. Its value is that of a fatty food which also contains traces of iodine, chlorine, bromine, phosphorus and sulphur. These contribute a slightly alterative property to the oil. It is used in wasting diseases, especially in tuberculosis, and in poorly noiu'ished children. The so-called scrofulous conditions are benefited by it. The taste of the oil is disagreeable to many, so it is used largely in the form of emulsion. The pure oil is sometimes used by inunction when stomach administration is impracticable. If taken about two hours after meals much of the unpleasantness in the way of eructations will be avoided. Typical emulsions are the following: Emulsum Olei Morrhuse cum Hypophosphitibus. — Emulsion of Codliver Oil with Hypophosphites. — ^This contains 50 per cent, oil, with hypophosphites of calcium, potassium and sodium (not official). Average dose, f5 4 (15 mils). ALTERATIVES. Alteratives have been defined as agents that counteract morbid states of tissues by altering the processes of nutrition in a favorable manner. They seem to have little direct influence upon irritability or functional activity of cells. Alteratives become a part of the cell contents for the time that they remain in the system, and some of the metallic alteratives become so fixed that they may be detected for weeks in the tissues. Their action is slow and their effects permanent, as might be expected of agents that enter so intimately into the composition of the cells. The typical conditions that call for their use are those that are brought about by the damaging influence of bacteria or toxic chemical bodies, that alter the nutrition of the cells. Syphilis stands as the disease that probably most purely presents the indications for the use of alteratives. Altered states of the blood and of organs likewise call for their use. of gradual improvement. Arseni Trioxidum. — i\.RSENic. — Arsenons Acid [AS2O3]. — The value of arsenic internally is mostly as a blood alterative, in those forms of anemia where the red cells are abnormal. It is also useful in certain nervous diseases, particularly in chorea (St. Vitus' dance), and in some chronic diseases of the skin. These three solutions are uniform in strength and have the same average dose, TTl 3 (0.2 mil). The first is arid in reaction, while the second and third are (dixalinc. commonly employed. Beginning with small or moderate doses, they may be increased to the limit of toleration, which is shown by irritability of the stomach and puffiness about the eyelids. bines arsenic, mercury and iodine. Hydrargyrum, — Mercury. — Quicksilver [Hg]. — (For fuller list of preparations and doses, see Index of Drugs.) Mercury is used very largely in the form of combinations, but there are several preparations in which metallic mercury is used, reduced to a very finely divided condition. Following are the preparations most commonly used: Hydrargyri Salicylas. — Mercuric Salicylate. — Mercuric Subsalicylate.— This salt is used largely hypodermically in the treatment of s}^hilis. Average dose, gr. i (0.06 gm.). The t}^ical use of mercury as an alterative is in the treatment of secondary s;vT)hilis. As it is desirable to obtain its full influence as soon as possible, the ointment or the oleate may be rubbed into the skin freely. Aside from these, the non-cathartic preparations may be employed internally. Blue mass and calomel are seldom given in syphilis, but are ^^aluable cathartic agents. The constitutional symptoms produced by mercury, with the treatment of the same, are discussed in the article on Antiseptics. (See also the article later on Syphilis and its Treatment.) ledum. — Iodine [I]. — This substance is not commonly administered in its free state internally, because of its irritating character. It is, however, a valuable alterative, and may be taken in large quantity in non-irritant of which is sodium iodide. Sodii lodidum [Xal]. — Estimated by the atomic weights of its components, this salt contains about 85 per cent, of iodine. Being much less irritating than iodine, it furnishes the means of getting a large amount of the latter into the system without much disturbance. This salt is used in the treatment of acute asthma, in chronic rheumatism and other conditions of tissue alteration, but its most extensive use is in tertiary syphilis. wSodium iodide possesses advantages over potassium iodide in the following points: It contains more iodine. It is slightly more soluble. It is less irritating, sodium being better tolerated by the system than is potassium. (See article below on S\^hilis and its Treatment.) in frequent use: Syrupus Ferri lodidi. — Syrup of Iodide of Iron. — This is " a very valuable preparation for use in the so-called "scrofulous" conditions. It may be taken for an indefinite period by children who show the characteristic enlargement of lymph nodes. Syphilis and its Treatment. Syphilis is a disease that is contagious and infectious in nature, one that may be met with in any walk of life, whether acquired innocently or through vicious conduct. It may be inherited in certain of its forms. It is a disease, moreover, of which its possessor may be ignorant, both as to its character and the source of infection, since the lesion of original infection, the chancre, may occur upon various parts of the surface of the body, where infection must have been purely accidental. The importance of this to the dentist is emphasized by the further fact, that the highly infectious secondary lesions are prominent in the mouth and throat, constituting here a danger to the dental operator directly, and to others indirectly. Syphilitic lesions are commonly painless, The occasional occurrence of a chancre upon the hand of a dentist, justifies the advice that a constant lookout for the presence of the disease, in mouths coming under examination, should be exercised. This implies a certain degree of familiarity with the symptoms of the disease. Every opportunit}', therefore, to study this disease should be improved, as a matter of personal safety and of duty to others. The dental specialist certainly owes it to his patients and to himself, to supplement his dental college course by a post-graduate study of syphilis in its chief clinical features. Without such thorough study of the manifestations of the disease, it is unsafe to attempt to diagnose its various lesions either of the mouth or skin, for the liability to error is very great ; and even physicians of experience will often seek expert opinion as to the nature of a suspected lesion. A word of caution is here appropriate. It may fall to the practitioner to discover a case of s^■philis, by mouth symptoms, where it had not been suspected; but he must be exceedingly cautious about discussing this finding with his patient. He is dealing with a matter for which he has not been consulted, and in any suspicious acts or words of his, lie the possibilities of much unpleasantness. If the patient be an innocent wife a statement of his discovery might produce domestic discord. "While she would have a most serious grievance, entitling her to om* pity, a revelation could only add to her unhappiness. A suggestion to her to see ^er family physician for certain general conditions that you find evidence of, would be the proper course; and even this advice must be given tactfully, without arousing suspicion as to the probabilities in the case, for, after all, a mistaken diagnosis is possible. Any other course would also endanger professional relations with the family physician. The point of greatest practical importance is, to be so careful in the manipulation of instruments as to avoid all danger of self-infection; for the saliva of a patient with secondary mouth symptoms may infect any abrasion of the skin that it comes in contact with. As a matter of course, all instruments and appliances used will be thoroughly sterilized immediately after the operation. Mucous patches anywhere upon mucous membrane of mouth or throat, usually u])on inner surface of cheeks or under tongue. bones, occurring mostly at night. Gumma, occurring mostly upon skin, in the nervous system, or smaller bloodvessels, but occasionally in any part of the system. Deep ulcers of the skin sometimes resulting from the breaking down^ of gummata. Usualh^ single, or, if double, located upon symmetrical portions of body. Degenerations of circulatory or nervous systems. The arteries, brain and spinal cord are usual sites of degeneration. iocUde. The discovery of the spirocheta pallida, beHe^'ed to be the cause of syphiHs, has rendered possible an early diagnosis in the primary stage, which permits the beginning of treatment at once, instead of waiting until the appearance of secondary s;^Tnptoms confirms the clinical diagnosis, as was formerly the common practice. The introduction of salvarsan also has marked an advance in the efficiency of treatment, whereby the disease may be arrested early and a cure effected without the occurrence of secondary symptoms. Outline of Treatment. — When a case is seen soon after the appearance of the chancre, the diagnosis should be made positive by the dark-field examination of scrapings or serum from the lesion. If this reveals the spirochete, treatment with .salvarsan should begin at once. This drug is administered intravenously in normal salt solution; 8 to 12 injections are gi\'en, at first weekly for five or six weeks, then at intervals of a month or more. In addition to this, a course of mercury is begun early and both remedies are continued during the first year. The preparations of mercury now most commonly employed are the oO per cent, ointment, by inunction, pushed to the point of saturation, or salicylate of mercury gr. 1 (0.06 gm.) given each week by deep intramuscular injection. Other preparations may be employed, some using the bichloride h\-podermically while others prefer the yellow iodide by mouth. Diu-ing the second year the same remedies may be continued at intervals, or treatment may depend upon the results of Wassermann blood tests made every two or three months. In case the s\Tnptoms do not yield readily, and particularly in the tertiary stage, an iodide by mouth (preferably soditun iodide) may be added to the treatment.* The question whether s^-philis may be cured has been regarded as a debatable one, but it is one which now admits of an affirmative answer. The fact remains, however, that very many cases are not permanently cured. AVhen we appreciate that a cm-e means the taking of medicines almost continuously for two years, and that syphilis is a disease whose SATnptoms yield very promptly to treatment, it caimot be expected that more than a small percentage of patients will continue treatment for the necessary length of time after they feel perfectly well. A positive ctu-e would mean a total of three years' observation, the first two with active treatment, and the absence of all symptoms with negative Wassermann tests thi'ough the third year. ^Marriage cannot be properly entered into without this thorough treatment and the three years of observation. of the class of vegetable alteratives: Colchicum. — (For preparations, doses and uses, see Index of Drugs.) Guaiacum. — (For preparations, doses and uses, see Index of Drugs.) Sarsaparilla. — (For preparations, doses and uses, see Index of Drugs.) Sarsaparilla must be regarded as the least valuable of this group. In fact, its value is so slight that it is seldom used alone. The proprietary "sarsaparilla tonics" all contain stronger agents, usually cathartic in action. * The continued use of any iodide commonly produces a rash, consisting of pimples upon the face and elsewhere, which is beUeved to be nature's efforts to eliminate iodine. This is the chief sjTnptom of iodism, or saturation with the drug. All sedatives may be poisonous when given in large dose; and the toxic s\iTiptoms usually include narcosis. The division of the large list of sedative agents into groups designated by the terms arterial, nervous, etc., is a convenience, and helps to fix their characteristic action, but no distinct lines can be drawn between the groups. The terms point rather to the most prominent features of their action. (See classification, page 37.) In a practical sense the term applies to effect but not always to action. Stimulation of inhibition may produce a slowing or restraining effect, which we may call depression induced indirectly by stimulation. Instances of this kind are well illustrated in the action of aconite, as Plate XIV shows. Most sedatives, however, produce their effects by a direct depressant action upon either nerve or muscle tissue. As a rule, children bear the moderate action of sedatives very well. The nervous system during childhood is so sensitive and responsive, that disturbed function in most cases calls for depressant rather than stimulant treatment. Cold must be given a prominent place among the arterial sedatives. Just as the application of heat acts as a general stimulant, so the application of cold produces the opposite effect. Hyperemias and acute inflammations, whether in and about a tooth or elsewhere, injuries to tissues leading to extravasation of blood, cardiac and cerebral excitement, all may be greatly relieved by the application of cold. In this class of conditions, however, the rule should be recognized of employing either cold or heat according to which affords the most relief. Methods of applying cold are : the full or partial cold bath, the Leiter coil through which ice-water is allowed to run, the ice-bag, and the application of liquids that evaporate rapidly. The employment of freezing methods belongs to another chapter. current. Heart. A direct influence upon the heart is uncertain, but by stimulation of inhibition the heart is slowed and its force weakened— the result being cardiac depression. (According to some authorities, the drug depresses the heart muscle and its motor ganglia.) The red color indicates the stimulant action of Aconite upon the vagus center, which causes slowing of the heart's action. The blue color indicates the depressant effect of the drug. Sexual function is depressed. Circulation. Arterial pressure is lowered somewhat. Heart. Large doses depress the heart slightlj^ Capillary area. Full doses cause vasomotor relaxation. Elimination. The drug is absorbed rapidly from the stomach and intestines, but is eliminated slowly. It may be found in the several excretions, but chiefly in the urine. This drug is used in fevers and inflammations, to reduce arterial pressure. The tincture is used internally, either 5 to 15 minims (0.30-1 mil) several times daily, or in two-drop doses hourly until the effect is secured. With an equal part of tincture of iodine, the tincture is used as an application in pericementitis and pulpitis. The alkaloid aconitine is applied locally in form of the oleate in the treatment of neuralgias, and in obstinate cases it may be given internally in doses of gr. ^q-q (0.00015 gm.). The preparations of wild cherry {Prunus virginiana) owe their sedative value to the presence of a small quantity of hydrocyanic acid. These are useful as excipients in cough mixtures; but when a decided effect from definite dosage is desired, the dilute hydrocyanic acid (2 per cent.) is used in doses of 1 to 2 minims (0.06-0.12 mil). The strong hydrocyanic or prussic acid is never used, as it is too poisonous even to manufacture. Sodii Bromidum. — Sodium Bromide [NaBr].^ — The sodium salt represents the group well, and is entitled to preference over the potassium salt, as it contains more bromine and is better tolerated. Bromides are freely soluble in water and in alcohol. Since they are quite salty to the taste they must be given largely diluted. The average dose is gr. 15 (1 gm.). The bromides are used in any conditions where there is cerebral or nervous excitement; in headaches, injuries to the brain, meningitis, hysteria, in epilepsy and other convulsive disorders; to control vomiting of reflex or cerebral origin. They are of special value in the nervous 240 SEDATIVES and febrile disturbances that occur so readily during infancy. They may be given freely, but always well diluted so as not to irritate the stomach.* The importance of sedatives in the management of first dentition leads to a brief consideration of that subject following the antipyretic group. in the form of white crystalline powders. As antip\Tetic sedatives they have power to lessen temperature in fever, and in addition they have anodyne properties. In fact, since they have come to be recognized as sedatives, being on that account inadmissible in the severe fevers, they have found their most extensive use in the treatment of headaches, neuralgias and myalgias. They differ in their activity and safety. Antipyrina [CUH12X2O]. — Average dose, gr. 5 (0.3 gm.). This is the mildest in action and also most soluble. It is of some value as an antispasmodic in the treatment of infantile convulsions and w^hooping-cough. ether and with solutions of carbolic acid. Acetphenetidinum.— Ppienacetine [CioHisNOa]. — Average dose, gr. 5 (0.3 gm.). This is more powerful than antip^Tine, but comparatively safe. It is practically insoluble in water. Acetanilidum [CgHgXO]. — Average dose, gr. 3 (0.2 gm.). This is the most powerful of the group and least safe. It is sparingly soluble in water. It has the power of producing alterations in the blood that may cause a decided appearance of cyanosis, when full doses are taken repeatedly, or too large quantity in a single dose. It must be used cautiously, if at all, and never continuously for any length of time. The compound powderf is a useful internal analgesic. The caffeine in this may aid the action of the acetanilid, but it chiefly antagonizes its * While the bromides in their ordinary uses are without danger, it should not be concluded that they are incapable of doing harm. Their prolonged use is not desirable, l)ecause they certainly do depress cerebral and nerve functions. The only unpleasant symptom commonlj^ attending their prolonged use is the occurrence of pimples upon the face and elsewhere, which is believed to be nature's effort to ehminate bromine. anilid is used as an antiseptic powder. Acid, Acetylsalicylic. — ^Aspirin (not official). — Dose, gr. 2-10 (0.120.60 gm.). This drug has come into popular use under the proprietary name aspirin, as a remedy for headache and for various slight pains. It should be employed under the chemical name. First Dentition Complications and Their Treatment. It has been remarked that children bear sedatives relatively better than they do stimulants. The basis of this fact is found in the more sensitive nervous s^^stem of the child. If we compare the size of the brain at birth with the total weight of the body, we find that its relative size greatly exceeds that of the adult brain. At the same time its function is more complex in that it is concerned with the process of development, which becomes less active later on. In consequence of this greater sensitiveness of the child's nervous system, impressions are magnified; not only do slight mental impressions beget fear or emotional outbreak, but slight nerve irritation which in an adult would be unnoticed, or, at most, would cause slight discomfort, in a child may produce fever and convulsions. Accordingly, a stimulant that acts through exciting or irritating a function or tissue will disturb rather than soothe, while a sedative will lessen the sensitiveness of nerve tissue and prevent the disturbances of function. Although occasionally so much depression may occur as to call for stimulants, as a rule they may be dispensed with in childhood, while sedatives hold a place of supreme importance, both as agents to prevent and to control the serious nervous disturbances that occur so easily during that period of life. But the common causes of infantile disturbances are not external, but rather the irritations that proceed from functions abnormally performed within the body. These irritations may be of great variety; but as we see the extreme sensitiveness gradually disappear with the development of the child, we recognize that the maximum of susceptibility to irritation exists early, or during the period corresponding to first dentition. We must be reminded that during this period the whole digestive tract is being prepared for a more complex function, that of digesting food of firmer quality and greater variety. From the teeth downward the provisions for solution and absorption of food are being developed and adapted, and throughout there is connection with the same sensitive, directing and controlling central nervous system. This is often shown very emphatically by the occurrence of vomiting or convulsions after the self-indulgent parent has enjoyed seeing the infant sit at the table and partake of the common family dishes, for which its digestive apparatus has not yet been prepared. Of all of the developmental changes, the process of eruption of the teeth is the most visible; and it has, therefore, been blamed too indiscriminately for the disturbances that often coincide with it. It is so easy to satisfy anxious inquiry by the statement that the convulsion in a given case is due to teething, or, if that is improbable, to suggest that the child may have worms. Without denying for a moment that abnormal dentition may be the cause of most serious disturbances, we must take a comprehensive view of the developmental diseases of infancy and not be too much influenced by what we may see at either end of the digestive tract. Teething and worms each have a pathologic importance, but we must not allow them to usurp attention that belongs to factors less apparent, but undoubtedly more important in many cases. We must hold improper diet to be an influence of first importance, and this refers not only to character of food, but to quantity and to intervals of feeding as well. Fermentation and putrefaction of food materials, and even infection in the intestinal tract, are prominent factors of disease at any age; but in the sensitive child, with full digestive capacity vmdeveloped, such factors are of superlative importance. There is, however, occasionally seen a case of the most serious general disturbance, where dentition and the digestive function appear to be normal, that must be attributed to a special susceptibility or an abnormality in the nervous system itself. Again, we are convinced of the prominence of the central nervous system as a primary factor, when we see a child of unstable nervous constitution have a convulsion from a cause that a normal child will successfully resist. These considerations bring into prominence the part of treatment that refers to the nervous system. It involves temporary prophylaxis as well as relief, and includes daily supervision of the child's diet and habits, with the judicious use of sedatives in order to lessen the irritability of nerve centers, so that they may respond less readily to irritating impressions. More important still is the prophylaxis that fortifies the nerve centers by increasing their stability or tone. Hygienic measures, including an abundance of fresh air, daily bathing with tepid or cold water, and proper feeding, meet this requirement. Probably the majority of children suffer with irritability and feverishness at some time dm"ing first dentition. As a rule the daily discomfort becomes more marked as the day advances, until midnight or later, when sleep may occur with frequent interruptions. Convulsion or spasm often occurs in the severer cases. The treatment of the condition will include the hygienic measures previously mentioned. The child should be taken out into the open air as much as is possible during the day as a matter of routine prophylaxis. Fever and fretfulness may be lessened by cold sponging or the cool bath. Medicines may not be needed in the early part of the day, but later, as the irritability increases, the bromides may be given freely and continued until the child rests. If the gums show great hyperemia over advancing teeth, scarification by means of a clean finger-nail or the point of a well-guarded lancet may afford much relief, but indiscriminate lancing of the gum is not to be advised. To refer again to the medicines that are useful, both arterial and nerve sedatives have their place, according to the predominance of vascular or nervous disturbance. The tj^ical arterial sedative drug is aconite. This may be given in form of the tincture, in a dose of one-half drop every hour until the circulatory excitement has lessened. Spirit of nitrous ether may be combined with it for the purpose of inducing sweating, the occurrence of which will reduce the fever. The indications for .this combination would be a full, rapid pulse with fever, and the medicine should be lessened or discontinued when these s}Tiiptoms abate. Aconite must be used with due care, for it is a poisonous drug in excessive dose; so the precise indications for its use and the favorable result of its action should determine the extent of its emplojTnent in any case. In most cases, the danger of convulsions, and the irritability of the nervous system, can be removed by the bromides, whose action is perfectly safe. Their use is addressed to the nervous element, which is usually \'ery prominent, while the circulatory disturbance is secondary and incidental. Therefore, the use of a bromide will, on the whole, be found most satisfactory, because it meets the primary indication of lessening the sensitiveness of the brain centers and, at the same time, can be used continuously in full doses without danger. Sodium bromide is the topical agent of the group, but it must always be given well diluted, so as to avoid irritating the stomach. The \\Titer has never found the drug to cause vomiting when given freely diluted. It may be given in a dose of 5 to 10 grains (0.30-0.60 gm.) to a child one year old in the emergency of a convulsion, but the dose for continuous administration is 1 to 3 grains (0.06-0.20 gm.). The following formula is simple and useful: The above formula may answer every purpose of necessary medication in the simple irritability of the period of first dentition. Following the directions previously given in respect to hygienic treatment, the bromide need not be given until the beginning of the daily period of increased irritability, which occurs toward evening. Then it may be given hourly until the child is able to rest. It is then advisable to stop the medicine until the next afternoon, or, at least, to reduce it to longer intervals of administration during the morning. Convulsions. — When spasms occur, the twitching or stiffness of the muscles is attended by unconsciousness. This shows that the brain is concerned in the effects of the irritation, wherever the latter originates. The condition must be treated as an emergency, the aim being to restore consciousness and relieve the convulsion. The head is usually hot, while the extremities may be cold. The treatment will embrace several measures: treatment under 1 and 2. Under the first heading we employ means of bringing blood to the surface of the body, such as the hot (very warm) bath to the whole body except the head. If the latter is hot, cold applications should be made to it, as this will aid in securing the same object by driving the blood from the brain. ]\Iustard flour (1 to 4 teaspoonfuls, mixed first with a rubefacient eftect. Meanwhile, treatment coming under the second heading should be employed. ^Nhl\e the convulsion is present it may not be possible to at once remove the irritation, which may be in the digestive tract; but the severity of its effect upon the brain may be lessened by the administration of sedatives. An excellent combination is that of sodium bromide and antip\Tine, the latter having both antispasmodic and antip^Tctic value, and producing also a tendency to perspiration. A combination, giving the emergency dose of sodium bromide as 5 to 10 grains (0.300.60 gm.) and of antipjTine as U to 3 grains (0.10-0.20 gm.) according to age, is here given: given carefully, a few drops at a time. A full dose of castor oil should be given, if swallowing is possible, so that any irritant in the digestive tract may be carried onward. It is not advisable to give an emetic during a spasm, for fear of vomited matter being drawn into the trachea. If relief does not follow in say haK an hour, treatment coming under the third heading may be employed, and this will usually be the cautious use of chloroform by inhalation, the object being to relieve the spasm by direct action upon the brain, with which result sleep takes the place of the coma. From this sleep the child may awake relieved, but in severe cases it may still remain in the convulsion. Spasms can usually be controlled by chloroform, but its continuous inhalation is in itself dangerous, so that reliance for permanent relief must be placed upon the other measures that remove the source of irritation, that relieve cerebral hj-peremia, and that lessen the irritability of the brain centers more permanently. when convulsions are persistent. For treatment beyond the emergency period, the bromide and antip}Tine may be continued at the intervals necessary to prevent restlessness and fever. A cathartic should be employed, unless previously given, to ensure emptying of the digestive tract, where the irritation may have originated. For this purpose castor oil is our first choice, being efficient and harmless. Succeeding the hot bath, the child should be wrapped in hot blankets, in order to keep the blood toward the surface and to favor sweating. If dentition is found to be abnormal or difficult, and teeth are nearly ready to appear, the gums may be scarified as mentioned before. But cutting the gums over teeth that are not likely to appear for several months is questionable practice, as the tissue will rapidly heal, and may even present the additional barrier of scar tissue to the later progress of the teeth. When, however, the gums are very much swollen and congested, scarification may be advisable independently of the state of progress in the eruption of the teeth. Other means of accomplishing the objects set forth above may be employed; simply the outline of common practice is here given. In the cases that present an evident infection, the treatment will, as a matter of course, vary according to its nature and the indications it furnishes. Chloral [C2HCI3O — H2O]. — Chloral hydrate is a typical hypnotic. It is used to induce sleep and to relieve convulsions. While at one time it was our only efficient hypnotic, it has been supplanted to a considerable extent by the newer and safer agents. It does not relieve pain in safe doses. Care must be taken not to exceed the safe dose, gr. 5-20 (0.30-1.30 gm.), as it may easily be poisonous. Sulphonethylmethanum. — Trional. — These drugs are safer than chloral but slower in action. Trional is more soluble than sulphonal, therefore usually preferred, but either must be given several hours before the eft'ect is desired. Dose of each, gr. 15-30 (1-2 gm.). Opium is the concrete exudation obtained by cutting the unripe capsules of the opium poppy, Papaver somnifenim. It contains, in its fresh, moist condition, at least 9.5 per cent, of morphine (when dried about 10-10.5 per cent.), besides a number of other alkaloids. Temperature. Eeduced by full doses. Metaboli.rm. Destruction of proteids is increased with less perfect oxidation. With prolonged administration fatty degeneration of various organs may occur. Center The blue color indicates the sedative effects of Chloral. The marked depressant action upon respiratory and vasomotor centers, andupontheheart. renders Chloral much more dangerous than the bromides, whose effects are similar in kind. of the drug, wherever applied, being almost nil. C'h ildren are very sensitive to th is drug, and, if needed, it shoidd be used in the iveakest preparations, and in less than the proportional dose. Brain, Depresses cerebrum, lessens power of attention, and diminishes sensation of pain. Medulla. Depresses resjjiratory center. Spinal cord. Does not perceptibly influence the cord. Note. — In the lower animals morphine is a stimulant to the spinal cord, but in man marked depression of the highly developed brain prevents any manifestation of spinal stimulation. by ordinary doses. Heart. Opinions difier. Any influence of a moderate dose must be slight and probably indirect. Large doses slow the heart by Digestive System. Stomacti. Secretion and motility lessened. Intestines. Peristalsis is greatly diminished. Elimination. Secretions generally are diminished, except the pei-spiration. The drug is partly changed in the system, but the greater part is eliminated by the gastrointestinal tract. habit. Whenever, therefore, it is used, poisoning and habitual use must be guarded against. It must be administered with some caution to persons whose susceptibilities are not known, and as a rule it should not be given to infants and young children. The prominence of the brain in childhood makes the child exceedingly susceptible to the influence of this drug, whose action is chiefly upon the brain and medulla. Fortunately this drug is little needed in dental practice, because it has little or no local action. Its inutility to relieve pain by local application has been discussed in connection with arsenic. Practically the only conditions in which it is called for are severe pulpitis or pericementitis, which fail to be relieved by ordinary local treatment. Here a few small doses of the drug may be given to the patient, but it should not he prescribed in any quantity, for fear that the relief obtained might lead to an easy later resort to the drug, with formation of habit. In the rare cases where it becomes necessary to administer the drug to a child, a much smaller dose must be used than that which the rule would allow.* The preparation used mostly with children is the camphorated tincture of opium, commonly known as paregoric, which contains only 0.4 per cent, of opium. The rule should he not to give opium or morphine to children. Persons who take this drug habitually acquire a tolerance for it, that permits them to take very large doses. While the usual dose of morphine is I of a grain, a victim of the habit may come to use 10, 20 or 30 grains daily. Indeed, there is the need of increasing doses in order to maintain the original effect, even where it is taken for a comparatively short time for the relief of pain. This shows that the tolerance of the drug begins early. Again, when the system has become accustomed to its action, it is usually difficult to stop the use of the drug without some discomfort in the way of unrest, that is at once relieved b}- its readministration. On these accounts it is very easy to acquire the opium or morphine habit, and very difficult to overcome it without the fullest cooperation of the victim with the medical adviser; and with the habit once thoroughly established, subjection to the discipline of a hospital will usually be required in order to succeed. (For poisoning by opium or morphine, see Table of Poisons and Antidotes.) Morphina [C17H19NO3+H2O]. — This alkaloid was isolated from opium and described by Sertiirner in 1816, and was the first to be discovered of the whole class of alkaloids. It has stood during the years since as the most representative principle of opium; and, while its action varies slightly from that of the whole opium, the uses of the two substances are identical, except that for hypodermic use a morj)hine salt is always employed. Being a very powerful drug, morphine has to be used with caution. For its action in detail, see Plate XVII. Its official salts are: increased as needed up to twice the quantity, in their ordinary use. Codeina [Ci8H2iN03+H20]. — Soluble in 88 parts of water. Codeine is less powerful and less depressing in action than morphine, and its after-effects are less unpleasant. Its official salts are: 3. The jalap and colocynth group. These correspond largely to groups A, B, and D as given below. The diagrams are intended to show the different ways in which cathartics may act. some is too extensive to be limited to one group. The numbers indicate the diagrams that represent what is believed to be the most prominent action in case of each drug, not always the complete action. Cathartics act by influencing these several factors. Laxative foods act by reason of their indigestible residue. Almost any cathartic may have simply a laxative effect when used in small doses. Purges, by their irritating action, stimulate peristalsis, the milder ones acting mainly upon the large intestine (1). Some, in large doses, approach drastics in severity of action (5). The absence of bile diminishes the activity of podophyllum, jalapa, rheiun, senna, and scammonium. Hydragogues act in two ways : The less irritating salines cause a marked increase of fluid by determining a flow of serum from the blood into the intestine (3). A low blood-pressure diminishes their activity. The more irritating hydragogues stimulate very promptly peristalsis of the small intestine, with the result that the fluid contents are hurried onward and absorption is lessened (4). Secretion also may be increased. Copious liquid stools result. Drastics stimulate powerfully the peristaltic movement of the whole tract (5), causing prompt, frequent stools, with severe gi-iping. In large doses they act as irritant poisons, and may cause contractions in the gravid uterus. Cholagogues favor the flow of bile into the duodenum, ^ probably through the increased peristalsis. The in-J;Z- fluence of cathartics upon the function of the liver seems uncertain and indirect. ELIMINATn:ES. A GROUP of functions that are liable to disorder in connection ^Yith any general disease, comprises those that secure the discharge of waste or used-up matters from the body. These functions are called eliminative, and the organs chiefly concerned in their activity are the skin, the kidneys, the intestines and the lungs. Eliminatims are those agents that increase the eliminative activity of these several avenues of excretion. Diaphoretics are agents that induce sweating. Emetics are agents that cause vomiting. Their action is not so purely eliminative, as vomiting is not a normal eliminative function, but rather a result of irritation, or a symptom of disease. Their eliminative value is seen mainly when a poison or foreign substance requires to be removed from the stomach. Expectorants are agents that increase the secretion of the air passages. In a study of the subject of elimination, we observe a certain complementary relation between the activity of the skin and of the kidneys. A certain amount of water, holding excretory matter in solution, passes out of the body daily, chiefly by the skin and kidneys; and, while the solids are separated from the blood chiefly by the kidneys, the amount of water which they excrete varies greatly, being influenced especially by the activity of the skin. In summer, when perspiration occurs freely, the urine is scanty in quantity but concentrated; while in winter, when the cool temperature lessens cutaneous elimination, the water passes out mainly by the kidneys, causing a large amount of diluted urine. In the application of diaphoretics and diuretics we should take into account this relation, for some agents will act in either way. For example, sphit of nitrous ether, when taken in the evening, with the skin being kept warni during the night, will induce sweating; whereas, when it is given in the morning, followed by exposure to a cool out-of-door temperature, it will act as a diuretic. To some extent bowel activity also may relieve the kidneys. We have, therefore, two resources in the direction of Diuretics increase activity of the kidneys in several ways. 1. Some alter the composition of the blood by increasing its salinity. The potassium salts especially act in this way. Potassium is less needed by the system than sodium ; therefore a moderate dose means an excess in the blood, which naturally passes out by the kidneys, carrying considerable water with it. This explains why potassium salts are diuretic while sodium salts are not. The most valuable for this purpose are the following : Of these potassium salts, the acetate, citrate and bitartrate are harmless when given properly diluted, and their use may be continued indefinitely. The bitartrate is cathartic when given in large dose. The nitrate is used with caution, as it is believed to be more stimulating to the kidney. 2. Another class of diuretics act chiefly by increasing arterial pressure. In many cases where elimination is deficient, it is because the circulation is weak and the arterial pressure low; in fact, the balance of blood pressure has been transferred from the arterial to the venous side, which causes dropsy or edema. The best kind of diuretic here may be an agent that restores the balance of pressure to the arterial side, even though it does not directly stimulate the kidney structure. The following drugs act in this way: 3. Still other diuretics act by stimulating the secreting structure of the kidney, leading to a better excretion of solids. These are sometimes called stimulant, or specific, diuretics. Heat in form of hot-air cabinet bath, hot-air bed bath, hot mustard foot bath, and hot teas of various kinds drunk in good quantity, is a most important and probably the most reliable agency for inducing sweating. EMETICS. The agents that induce vomiting act either by irritating the mucous membrane of the stomach, causing reflex contraction of stomach, diaphragm, and abdominal muscles, or, by acting directly upon the vomiting center in the medulla, they stimulate the same motor activities. The first three are commonly used, being reliable and safe. Sulphate of copper is more irritating, therefore capable of doing harm. Tartar emetic is also very depressing, and has often caused poisoning. 252 ELIMINATIVES Apomorphinse Hydrochloridum. — Hydrochloride of Apomorphine. — This is an artificial alkaloid derived from morphine. As it acts upon the vomiting center, it may be given hypodermically in cases of poisoning by opium or other narcotics, where the patient does not swallow. The dose h>T)odermically is gr. ^ ^ (0.006 gm.). The use of emetics has lessened somewhat since washing out of the stomach (lavage) has become such a common procedure. The latter has the advantages of emptying the stomach without an}' delay and permitting a thorough washing of its walls. The uses of syrup of ipecacuanha with children merit special attention. In cases of spasmodic croup it is employed, in emetic dose, for the purpose of securirLg complete relaxation of the respiratory apparatus, with relief of the spasm in the larynx. Also in the treatment of bronchitis in children too young to expectorate, its emetic action is employed in order to expel mucus from the air passages, where its accumulation interferes with breathing and provokes coughing. For both purposes mentioned sjTup of ipecacuanha is given in doses of one-half to one teaspoonful (2-4 mils.), repeated in half an hour if necessary, the purpose being to induce vomiting. Ammonia and ammonium preparations are largely eliminated by the air passages, and they at the same time stimulate the mucous secretion. The chief ones of value are the two following, the first of which is also a general stimulant, and used on this account in the more depressing respiratory diseases, such as pneumonia. ANIMAL DRUGS. Substances of animal origin have from time to time found a place in our materia, medica. Some have fallen largely into disuse, such as musk and castor, of the antispasmodic class. More recently the digestive enzjTiies have been recognized as having a positive value and, while both pepsin and pancreatin are official, even their use has diminished very much with a better knowledge of the physiology of digestion. But the past decade has seen the fuller development of preparations of some of the ductless glands, representing internal secretions of the greatest importance to the nutrition and well-being of the body. These will be discussed as fully as the scope of this book demands. They are employed in the form of the dried gland or of an extract of the gland tissue and in case of the suprarenals an active principle (epinephrine) has been isolated. This substance is absolutely essential in the treatment of conditions due to deficient th\Toid secretion, the disease known as myxedema yielding very promptly to its use, while the more advanced state of malnutrition known as cretinism, if recognized earh^, shows the most remarkable improvement under its use. Since these conditions are due to deficiency of th\Toid secretion, it follows that the treatment must be continued through life. The value of this substance depends upon its power of stimulating, by local action, structures innervated by the sympathetic nerves, particularly the unstriped muscles of the arterioles and the accelerator terminations in the heart. For emergency stimulation of the circulation it is given intravenously, since administration by stomach or hypodermically produces very little effect. hemorrhage from small vessels and in connection with cocaine or other analgesics. In the latter use, chiefly by hypodermic injection with the analgesic, its vasoconstrictor action prevents rapid absorption of the latter, holding it to the desired locality, thus rendering its action more efficient and safer. The active principle of the suprarenal gland (epinephrine, Abel) is used largely in form of the 1 : 1000 solution called Solution of Adrenaline Chloride* (not official). — This may be added to analgesic solutions, at the time of use, within the limit of the internal dose of TH, 10-30 (0.60-2 mils). In nosebleed and other small hemorrhages this is one of our most valuable local agents. The pituitary body seems to be related to the function of growth, its overaction causing an abnormal and excessive enlargement of part or whole of the body, the conditions known as acromegaly and gigantism. Its therapeutic value, however, depends chiefly upon its power to stimulate unstriped muscle, whereby it induces constriction of the peripheral arterioles, stimulates motility of stomach and intestines, increases the secretion of milk and stimulates uterine contractions. In ordinary doses it has little or no central action upon the nervous system. It is administered in solution either hypodermically or intravenously, since it has little effect when given by mouth. The official solution is This agent consists of certain antitoxic substances obtained from the blood serum of the horse, after subjecting the animal to increasing doses of diphtheria toxin, whereby immunity against the toxin is secured. The purified antitoxin, as commonly used, either hypodermically or intravenously, has the antitoxic globulins dissolved in physiologic solution of sodium chloride and has a potency of not less than 250 antitoxic units per mil. This agent consists of certain antitoxic substances obtained from the blood serum of the horse, after a process of immunizing the animal against tetanus toxin. Used commonly in the physiologic sodium chloride solution (purified form) it is found more efficient as a preventive than as a curative agent; hence, it is common practice to inject hypodermically a protective dose after any injury that presents the probability of tetanus infection. For some years past Fourth-of-July injuries have been thus treated, with the result that cases of tetanus, formerly very frequent after these injuries, have been reduced to a small percentage. Its use after the disease has developed is less successful, and here, as an aid to other treatment, it is administered intravenously or, better still, injected directly into the spinal canal. Tetanus antitoxin has a potency of 100 units per mil. Pepsinum. — Pepsin. — ^White or yellowish scales or powder, being a mixture containing a proteolytic enzyme, obtained from the stomach-wall of the hog. It should digest not less than 3000 times its weight of egg albumen. Average dose, gr. 8 (0.5 gm.). While meeting certain indications of deficient digestive power in the stomach, pepsin is now used much less than formerly. It is often given in an acid solution in imitation of the gastric juice. Pancreatinum. — Pancreatin. — Extract of Pancreas. — A cream-colored powder containing amylopsin, trypsin and steapsin, obtained from the pancreas of the hog or the ox. It should change not less than 25 times its weight of starch into soluble carbohydrates. Average dose, gr. 8 (0.5 gm.). Since pancreatin contains at least three enzymes, it has a wider application to digestive diseases than does pepsin. It is administered usually in powder form, with addition of sodium bicarbonate to insure an alkaline medium for its action, in imitation of conditions found normally in the small intestine. In intestinal indigestion at any age it is found useful, and it is often employed to predigest (peptonize) food, especially milk, for administration either by mouth or by rectum. It is regarded as irrational to use pepsin and pancreatin together, since the former requires an acid medium for its action, while the latter acts best in an alkaline medium. DENTISTRY DURING PREGNANCY. The decision of the question as to performing dental operations during gestation must usually rest upon the combined opinion of family physician and dentist. It is easy to formulate rules of practice, but these may just as easily be disregarded in the presence of an urgent condition. It must always be remembered that gestation is usually a normal, physiologic process, which should permit liberty of treatment within sensible limits instead of imposing too strict limitations. upon the senses may be the cause of birthmarks. This belief, though it has the support of some authorities, cannot be given any physiologic basis. The fact that no nervous connection exists between mother and embryo weighs heavily against it; for that fact requires the assumption that some blood condition of the mother is capable of influencing in a peculiar way some particular embryonic tissue; in other words, to exert a selective influence. Assuming such an improbability, it still could not be believed that tissue once normally formed can be subject to such influence; therefore, it is safe to state that any detrimental impression can be potent, if at all, only during the early weeks of gestation, the time of conception doubtless being the most impressionable period. The period of greatest liability to possible dangers of this kind being then at a time when it is as yet uncertain whether pregnancy exists, it, indeed, being oftentimes unexpected, it is evident that we can exercise practically no control in this matter; and for the dental practitioner to observe the general rules to be given later, should suffice as far as he can be concerned. three months constitute the period of greatest nervous instability, as shown by reflex vomiting, which occurs in the healthiest women as well as in the less vigorous. The system is accommodating itself to the new order of affairs. Certain organs are undergoing change to accommodate new or increased function. Latent weakness of organs is apt to become manifest. It is the period which usually determines whether accommodation and compensation can sufficiently occur, for it is the period of most frequent failure; which is to say that abortion occurs most frequently during the first three months. This period once passed without accident, health and vigor improve, so that after the fourth month the state of health is often the best ever experienced. This satisfactory status continues to the end of gestation; except that during the last two months there is danger of premature labor being induced through shock or violence. During the first period any considerable operation should be avoided, unless absolutely necessary. Prolonged filling operations, or extraction of a tooth, had better be postponed until after this unstable period of accommodation and great susceptibility. But it must be plain that even the extraction of a tooth may occasion less disturbance than toothache prolonged through several days with sleepless nights. In case of an extraction being positively necessary, an anesthetic may be used at the discretion of the family physician. From the foregoing it appears that the time of choice for dental operations lies within the second period, and preferably during the fifth and sixth months. At this time the general health is at its best and the danger of disturbing gestation at its minimum. There is no good reason why any necessary dental work should not be done during several months at this time. There should be every care taken to avoid the infliction of pain, and short sittings should be the rule. Anesthesia of short duration is admissible when necessary, the choice of agent to be left to the family physician. It should, however, be noted that all during gestation there is an essential tendency to toxemia upon slightest provocation, because of the extra demand upon nutrition and elimination. It is a question, therefore, whether any anesthetic should be used that will increase this tendency or add to its results. The exclu- sion of air during the induction of anesthesia, as is common with nitrous oxide, should be avoided, as directly contributing to auto-intoxication, and this means that inhalers that do not allow free access of air, or those that require the rebreathing of expired air, should not be used. In the third period a restrained posture in the dental chair for any length of time may mean serious discomfort. Add to this the danger, though slight, of provoking premature labor, and we are brought to the conclusion that dental operations should be avoided during the last two months, if possible. ^Yhere dental work seems necessary during this period, the operator should consult the family physician before undertaking the same; for it may be that there are unfavorable points in the patient's condition that are known only to her physician. Care of the Mouth during Pregnancy. — Because of the abundantly observed fact that caries of the teeth makes rapid progress in the teeth of pregnant women, care of the mouth with a view to prevention of caries becomes very important. It was earlier believed that the tooth structure suffered a change by giving up some of the mineral salts to meet the needs of the growing embryo. If this were true it would seem that Xatm-e had shown herself seriously at fault in failing to provide sufficiently for the assimilation of materials that are very abundant in the foods commonly taken. However, it has been shown by Black* that the teeth of females during the period of life when child-bearing occurs, average slightly harder and denser than the teeth of males during the same period of life; and the conclusion follows that the prevalence of caries must be explained in some other w^ay. When we consider the active part that acids take in the production of caries, it is only necessary to point out that the usual vomiting of pregnancy, which occurs during the first three months, brings acid stomach contents daily, and oftener, into the mouth and in contact with the teeth, and we have the basis of a rational explanation of the rapid progress of caries. Also, with the attention fixed upon other matters, and with more or less general indisposition, the teeth are very likely to be neglected just at a time when they need extra care. Upon the basis of this explanation the proph^daxis will be simple and efficient. If we are in a position to advise early, education of the patient comes first; then the simplest kind of an alkaline mouthwash, such as lime-water or saturated solution of borax or of sodium CARE OF THE MOUTH DURING PREGNANCY 259 bicarbonate, used freely at frequent intervals and immediately after every occurrence of vomiting, and continued diu'ing the early months, ought to suffice in a special way. The usual directions as to general care of the mouth and teeth will, of course, be emphasized. Unfortunately, even the physician is not consulted in the average case until the period most important for prophylaxis is past; therefore, every suitable opportunity of educating mothers and those likely to be mothers, upon these points, should be improved. PRESCRIPTIOX WRITING. The T\Titing of prescriptions is an art that requires practice for its perfection. Its basis must be a certain attainment in the knowledge of drugs, their activities and their doses, as related to their selection for certain diseases; also of their physical and chemical qualities as related to form of administration and possible combination with other substances. \Yhile it is easy to order a simple solution of a common substance, the forming of an original compound prescription, to suit a special condition, calls for the exercise of as much and as varied ability as does almost any function that pertains to the physician's duties. After the prescriber comes to a point in experience when his remedies are familiar and his own combinations of them are established, their prescription by him in any modification to suit special cases is comparatively easy; but to the beginner in practice, nothing is much more difficult than to write original prescriptions with any degree of confidence. The art of prescribing is quite ancient, having been employed first by the physician to guide his assistant in preparing his medicinal mixtures, the office of physician haidng included also that of apothecary. Today, with pharmacy developed into a distinct profession, our prescriptions are intended to direct the preparation of a medicine to be supplied by the pharmacist to the patient, to be used according to the 'vsTitten directions of the prescriber. There is a marked contrast between ancient and modern prescriptions, in respect to their definiteness and simplicity. Reference to the works of Fallopius, who lived 1523-1562, furnishes an illustration of complexity in prescribing, in a formula written by him, which contains thirty-two different ingredients. Since the sixteenth century we have learned enough about the human body and its diseases to know that it is unnecessary to exhaust our materia medica in prescribing for any one disease, and, with a more definite knowledge of the action and effects of drugs, we find that only a few agents can be employed to real profit in meeting a pathologic condition. Hence, our prescriptions of today approach the extreme of simplicity, usually containing not more than three or four ingredients. The term "shotgun" prescription is derisively applied now^ to a formula containing a large number of substances, upon the supposition that it is expected to hit somewhere. A certain idea of definiteness, however, is traced back to Asclepiades (about 100 B.C.), who is credited with formulating the object of treatment to be to cure quickly, safely and pleasantly (curare cito, tide et jucunde), and this has led to a recognition of the typical formula as consisting of four ingredients, each related to this object and named accordingly. 2d ingredient — Adjuvant or auxiliary. Quickly. 3d ingredient — C'orrigent or corrective. Safely. 4th ingredient — Excipient or vehicle. Pleasantly. While these terms aid us in comprehending the full purpose of prescription writing, it must be understood that a formula need not contain more than one active agent, and that any combination of medicines should always be based upon definite objects to be attained, either as to form or utility. cine, to which is added the directions for its use in a given case. Whenever a prescription orders an official formula, only the title of the latter need be given, without naming the ingredients. Thus, Dover's powder (containing opium 1 part, ipecacuanha 1 part, and sugar of milk 8 parts) is official under the title Pulvis Ipecacuanhse et Opii. In prescribing, therefore, it is only necessary to write — if it were not official. A pharmacopoeia is a book of national authority, containing a list of recognized drugs and preparations, with their descriptions, tests and formulas. It is the authoritative standard for the purity and strength of drugs and for uniformity of preparations. It may give the average dose of each internal remedy, but it includes nothing of the actions and uses of drugs. While in most countries the pharmacopoeias are under governmental control, the United States Pharmacopoeia is under the control of the professions of medicine and pharmacy, and is revised by their direction every ten years. SELECTION OF INGREDIENTS. Selection of drugs must depend primarily upon a knowledge of the conditions to be treated and acquaintance with the power of drugs to remedy the same, and secondarily upon the practicability of their administration or their combination with other necessary ingredients. Some drugs, by reason of their chemical properties, must always be given alone; others cannot be brought into solution; others are poisonous. aconite is added to tincture of iodine to render its action milder. (b) By rendering the action of the base safer. Here antagonism of drug actions is made use of, as in the common addition of atropine to morphine in order to counteract its depressant action upon the respiratory center. 4. To secure a suitable form. (a) By the use of special solvents to obtain a liquid form of an otherwise insoluble substance — e. g., salicylic acid requires 460 parts of water to dissolve it, but if borax is first dissolved to saturation salicylic acid is soluble in less than 100 parts of the solution. (fe) By securing a finely divided state of the drug. Sugar of milk is often used, on account of the hardness of its crystals, to rub up other drugs into very fine particles, as in tablet triturates. 5. To obtain a combination to act as a new substance. (a) By simple mixture. Dover's powder contains opimn and ipecacuanha, the combination having a diaphoretic effect not possessed to any degree by the separate drugs. official syrups, it will preserve the preparation indefinitely. Knowing what substances we wish to combine, the form of the combination must be determined, whether powder, pill, capsule, or liquid. For the first three the quality of solubility is unimportant, but when the medicine is to be in liquid form, solution must be secured whenever it is possible. SOLUBILITY. The prescriber should familiarize himself with the solubility of each of the solid substances that he is likely to use, for the reason that no rule of solubility can be laid down. A few general statements, however, may serve some purpose. good preservative. With some drugs it is necessary to add an acid, and with others an alkali, to aid solution — e. g., borax will aid solubility in water of both benzoic and salicylic acids; on the other hand, quinine sulphate has its solubility in water increased by the addition of sulphuric acid. A number of substances can be conveniently handled in saturated solution, some to be used in full strength, others requiring dilution. The following table furnishes the degree of solubility, and also the approximate percentage strength of saturated aqueous solutions, of a number of the most commonly used substances : [For solubility of other agents, see Index of Drugs.] The following table is of convenience in preparing any solution of a desired percentage strength. Quantities are expressed in the old system of measures, with metric equivalents also given. The result is not absolutely exact, but sufficiently so for practical purposes: INCOMPATIBILITY 267 To illustrate: suppose a fluidounce (30 c.c.) of a 2 per cent, solution of cocaine hydrochloride is wanted. Opposite the desired quantity in the first column find the quantity expressed in the 2 per cent, column, which in this case is 10 grauis (0.60 gm.). This dissolved in the fluidoimce of water will make the desired strength of solution. Unless the ingredients of a prescription are compatible with each other the object of their combination may be lost, for a reaction may occiu- between two drugs, with the result that the activity of each is altered or destroyed. Again, such reaction may. in case of certain substances, produce poisonous compounds. Incompatibility may be physical or chemical. Physical Incompatibility consists of (a) alterations in conditions of solubility without any chemical change, and also (h) pertains to the inability of certain substances to mix with each other, as oil and water. Examples of physical incompatibility are: 1. Gums and mucilaginous substances are precipitated from aqueous solutions by alcohol and alcoholic liquids — e. g., syrup of acacia with tincture of chloride of iron will precipitate the acacia. 6. Formation of explosive compounds. It is difficult to bring aU instances of chemical incompatibility under rtile; and the knowledge of chemistry necessary to predict always that incompatibility will or will not occtu, is not a common possession. In addition to the more important incompatibilities previously given in connection with the individual drugs, there are given below some general statements that will serve as a basis for study. A cardinal rule to be observed is that drugs should never he prescribed with their chemical tests, unless a chemical reaction is desired. ANTAGONISM OF DRUGS It should be noted that chemical incompatibility may be intentional, in order to obtain a new substance — e. g.,in. preparing ferri hydroxidum, magnesium oxide (alkaline) and solution of a ferric salt (acid) are mixed, the result being a precipitate of the hydroxide. Also, in the employment of chemical antidotes in the treatment of poisoning, their value is based upon their incompatibility with the poison. The term therajjeutic incompatibility does not apply to the combination of drugs, but to their action. It is often used to designate what is better known as antagonism of drugs. We recognize and employ the opposite effects of drugs to the extentof combining them in order to guard against poisoning, and of administering, in case of poisoning, a drug that shall counteract or antagonize the toxic action. In this sense we speak of such drug as a physiologic antidote to the poison. But while we thus employ antagonism of drugs to good purposes, in our prescriptions we avoid combinations that will neutralize the desired effect of the principal drug or drugs, unless a corrective action is needed, as when belladonna or a volatile oil is added to a strong cathartic drug to prevent griping. Antagonism of drugs can seldom be absolute — i. e., there are very few drugs whose effects exactly neutralize the effects of other drugs. In cocaine poisoning we find that two drugs, at least, are needed to fully cover the depressant action of the poison. (Plate IV.) Antagonism, therefore, is usually only partial, but it still may meet the most serious sjinptom in a case. Thus in poisoning by morphine the most dangerous condition is that of paralysis of the respiratory center. Strychnine will antagonize this condition, though it has almost no influence upon the narcosis. Heart, vasomotor system. Cerebrum, respiratory center, heart. Cerebrum, respiratory center, heart. Respiratory center, heart, spinal cord. Heart. Medulla, spinal cord. Heart, respiratory center, spinal cord. Respiratory center, spinal cord. Respiratory center, other reflex centers. Vasomotor system. Antagonism of local remedies depends chiefly upon their chemical qualities, the action being usually an antidotal one, as when an acid is neutralized by an alkali, or silver nitrate by sodium chloride. This part of the subject is treated whenever necessary in connection with the various local remedies. (For chemical antidotes, see Table of Poisons and Antidotes.) DOSES. Posology, or the science of dosage, constitutes an important part of our knowledge of drugs. Whether we use few or many substances, safety requires us to know concerning each, what quantity may be expected to produce a certain desired effect and also what quantity must not be exceeded when it is necessary to secure its full physiologic influence. Conditions in disease vary so greatly, and the individual susceptibilities of patients are so uncertain, that we must regard the statement of a single definite quantity for a dose as being somewhat arbitrary. Therefore, it is advisable to know, not a single quantity, but a range which THE PRESCRIPTION 271 shall include the mmimimi and the maximum of ordinary dosage. Idiosyncrasy forbids the use of certain drugs with certain individuals. It also modifies the action of the drug in some cases. Tolerance for certain drugs, particularly morphine, may be established, so that those who take it habitually frequently come to use doses many times greater than the ordinary poisonous dose. The mode of administration, whether by stomach or hjTJodermically, wUl modify dosage. (See chapter on Administration of ^Medicines.) After all, the dose of a drug is a relative quantity, which reciuires to be varied, according to conditions, within a certain range of efficiency and safety. The doses of the principal drugs, or of one or two preparations of each, which represent them fully, should be learned. Dosage for Children. — The doses usually given in text-books and tables are for adults. For children only a fractional quantity, proportional to the age, may be used. The simplest rule for the calculation of a child's dose is that kno^\Ti as Coiding's Rule, which is: Divide the age of the child at its next birthday by 24, Thus a child three years old wiU have the age + 12, gives a slightly larger fraction; thus t — 7^=5- In connection with such rules it must be borne in mind that children are very susceptible to the action of opium and morphine; therefore, these drugs, always to be avoided ■^■ith children if possible, may only be gi^'en in much smaller quantity than the proportional dose by rule. These will be considered in order: 1. The Heading. — Anciently the prescription was begun with a prayer to Jupiter or other heathen deity. Later this was shortened to the simple sign of Jupiter (1^) . With an upright stroke before it we have a resemblance to the sign I^, which we use today. To us this sign really means: "Take," being an abbreviation of the imperative form recipe of the Latin verb recipio — to take. 2. Names and Quantities of Ingredients. — ^The names are usually written in Latin, for the reasons that this is not subject to the changes of a modern language and, being a universal language of science, it is known the world over. A formula in Latm, therefore, can be read anywhere in the world of science today, and doubtless will be just as current one hundred years hence as now. The quantities are expressed either in the terms of apothecaries' weight and corresponding liquid measure, or in terms of the metric system. The latter has the advantage of simplicity in being a decimal system. Calculation by it is easier, and there is less danger of error, because the position of a figure denotes its value, and not an added sign that may be poorly written. 3. Directions to the Compounder. — In most cases the precise mode or detail of compounding is better left to the dispenser, who is trained in that art, and the simple abbreviation ]M., which stands for the Latin imperative misce, meaning "mix," is sufficient. Only when the prescriber has special directions to give, or when directing the number of pills or powders into which a mixture is to be divided, need he write out his directions in full. Li such case Latin may be used, but plain English is preferable, unless the prescription is likely to go to a foreign country. 4. Directions to the Patient. — This part added to a formula makes of it a prescription. It is begun with the abbreviation Sig. (or S.), which stands for the Latin signa, meaning "Write;" and whatever is directed should follow this sign and be written without abbreviation, so that it may be copied verbatim upon the label. Not only should these directions be written out in full, but they should be read to the patient or attendant, in order to guard against danger through a possible error in copying. The directions to the patient must state how the medicine is to be used — if locally, the word " apply" may be included ; there is good reason also for placing immediately after the "Sig." the term "mouthwash," "gargle," "ointment," "wash," or whatever will best designate the nature of the local application and serve to guard against its being taken internally; if internally, the directions must include dose in drops, teaspoonfuls, etc., and the time or intervals of taking. This part of the prescription must be very explicit, and the common phrase "use as directed," with only verbal directions to the patient, should be discarded. In case a poisonous application is ordered it is well to add the word "Poison" to the directions, with, however, verbal explanation to the patient or attendant as to its proper use. THE USE OF LATIN IN PRESCRIPTIONS 273 5. Date and Signature. — The date is essential for reference, and the prescriber's signature for authenticity. It is common practice, however, to use printed forms which have the prescriber's name and address above or below the blank space reserved for the prescription proper, in which case the signature is often omitted. The name or initials of the patient should be added, in order to avoid the use of the wrong medicine, in case of more than one prescription being filled at the same time for different members of a family. Sometimes a special note in addition to all the above will be advisable, as when quite large doses of a drug are ordered; the statement "large dose intended," or writing out the quantity, will show the dispenser that the amount ordered is correct. Again, the evil of repeating prescriptions by unprofessional pharmacists may be guarded against by writing prominently upon the prescription the words "not to be repeated." The reference above to improper pharmacy leads the author to express his appreciation of the professional pharmacy which is so evident today. The knowledge of doses that the pharmacist is required to possess is a safeguard against errors of dosage in prescriptions. The prescriber is responsible for whatever he writes, but physicians have often been saved the humiliation of discovered error in prescribing, or the results that might follow, by the cooperation of the pharmacist in calling attention confidentially to the same — a kind of favor too often unappreciated by the prescriber. To write prescriptions in best form requires some knowledge of Latin, especially of the declensions of nouns and adjectives, but not more than can be acquired in a very short time with the aid of a Latin grammar. To one not sufficiently familiar with the language, this course is earnestly advised, as repaying well the effort that is necessary. As a means of review, and in order to emphasize what is really essential to our purpose, a brief outline of the essential grammatic forms is here given, without any attempt at completeness. Many case-endings are never used in prescriptions, and are, therefore, omitted. The genitive endings are given prominence because they are almost invariably employed. WEIGHTS AND MEASURES 275 Use of Cases. — The nominative case is never used in a prescription, as the sentence is ahvays introduced by the imperative recipe, the subject of which is tJiou understood. The complete sentence would be: Verbs. — The few verbs employed are in the imperative form except where the directions to the compounder are ^\Titten in Latin, when the passive form may be also needed, as: The system of weights and measm'es most approved in scientific circles is the metric system. Being a decimal sy.stem, it is easily mastered, and no student in any department of medical science should be excused from acquu'ing a practical familiarity with its use. The United States Pharmacoiceia employs it exclusively in the expression of quantities of ingredients. While it is not possible to discard the apothecaries' system entirely at the present time, because of the large number of practitioners who have used it for years, whenever the old system is employed its denominations may be reduced to three, as follows: The Metric System. — In studying the metric system advantage may be taken of its similiarity to our American system of money, using the latter to illustrate the former in a very simple way, as appears below. In the comparison below, the decimal point, or perpendicular line, is the dividing point between units and fractions: much as we do the term dime, using centigrams, as we do cents, for any fraction of the unit; but the term millioram, is much used because of the small fractions MEASURES ta.23 MINIMS Fig. 15. — Diagram shomag: 1. The capacity of 1 Hter with its equivalents. 2. Linear measures — decimeter and centimeter, with equivalents. 3. The cubic centimeter or mLUiHter, and gram, with equivalents. (Slightly reduced in size.) 1.6 Kilometers. While the gram is a measure of weight and the mUUliter of capacity, liquids may be weighed and expressed in grams. But the U. S. P. weighs solids and measures liquids in its formulas. To avoid confusion in prescribing, we specify both grams and milliliters in our prescription forms: Thus whole numbers (to left of line) will be read as grams if they represent solids and as milliliters if liquids, while decimal quantities will be read as centigrams and milligrams in either case, as the difference between the measure and weight of so small quantities is very slight. Rules for Use of the Metric System in Prescribing : The difficulty of applying the metric system to prescription writing by those accustomed to think in the old system is very largely removed by following the rule given below, which does away with the need of calculating total quantities, and renders prescribing much easier. As there are between fifteen and sixteen grains in a gram, the ordering of fifteen or sixteen doses always establishes a relation between the two systems, which permits us to apply the following rule.* 2. The number that represents the single dose of an ingredient in grains or minims will express the required quantity of that ingredient in grams or milliliters. For example: Gm. or mil. I^. — Pulveris ipecacuanha^ et opii (single dose 5 grains) 5 Pulveris digitalis (single dose 1 grain) ... 1 Strychninae sulphatis (single dose -'o grain) . . 02 It is found in practice that sixteen is a very convenient and usually sufficient number of doses in the average case, or until the treatment is to be modified. However, when one has mastered the application of the rule, it is a simple matter to double the quantities for twice the number or doses, or to reduce them for a lesser number. AYhile this rule does not apply in making solutions without definite dosage, the convenience of the decimal system in ordering and preparing percentage solutions is apparent. With a total quantity of 1000, 100, or 10 mils, the calculation of quantity of ingredients is very simple. COMMON MEASURES AND THEIR EQUIVALENTS. In the fourth part of a prescription (directions to the patient), the amount to be taken should be expressed in domestic measures as far as is possible, so as to be perfectly plain to the user. The use of the measuring glass, marked for quantities to correspond to the common measures of teaspoon, tablespoon, etc., should be encouraged in the interest of accuracy; for there is some variation in size of teaspoons as there are grades of fulness to the spoon, one person making it even full and another filling it to its capacity, which may mean a difference of fully thirty minims. The common practice of ordering doses in so many drops is likewise inaccurate unless one is sure of the size of the drop of the particular liquid as administered ; for there is a great difference in the size of drops, dependent not only upon the density and character of the liquid but also upon the shape of the opening from which it is dropped. For example, in dropping water from the mouth of an ordinary medicine bottle each drop may contain 1^ minims, while from an eye dropper the drops may ORDER OF WRITING A PRESCRIPTION 281 not measure more than ^ minim, varjdng according to size of opening and thickness of the glass. Drops of alcohol are approximately onehalf the size of drops of water under like conditions, while drops of ether and chloroform are still smaller. (See below.) It should be borne in mind, therefore, that although drops of aqueous solutions approximate minims in size, drops of alcoholic solutions, as tinctures, are about one-half as large and the number in a given dose will be correspondingly greater. But it is evident that the purpose of accurate dosage would be best served by the use of a pipette, marked for minims, in measuring out small doses. Tables of the number of drops in a fluidrachm are of comparative rather than positive value, because of the difference in size of drops of the same liquid under different conditions. However, it is well to remember the following easily-learned facts in regard to the size of drops: to a fluidrachm. It is well to follow a regular order in writing prescriptions both in the interest of economy of time and thought and in order to lessen the danger of errors by omission. Certain parts of the work can be made^quite mechanical including the use of a prepared form of blank something like the following: If the old system of weights and measures is to he employed this blank will omit the upright line and the abbreviations above it. The order usually followed in writing a prescription is as follows: Syrupi lactuccarii, 2. Decide upon the number of doses and bulk of each dose, by which you arrive at the total quantity of the mixture. For a child of five the single total dose may well be a teaspoonful and the number of doses 16, which gives a total quantity of 2 fluidounces or about 60 c.c. next birthday by 24," we obtain 2I or \ as the fraction of the adult dose to be used. But even with the use of the rule we must exercise discrimination. In this instance, potassium bromide being a rather harmless drug, we shall want a full dose in order to secure its depressant effect upon nerve centers, so we may exceed the proportional amount of the average adult dose. Let us take 6 grains (gm. 0.40) as the dose. Sixteen doses will give us 96 grains as the total quantity, or, approximately 1\| drachms (gm. 6). Of tincture of belladonna we take according to the rule \ of the average adult dose, ^ of 8 minims X16 doses =32 minims, or approximately \ fluidrachm (mils 2). Of spirit of nitrous ether we take \ of 30 minims as the single dose or 8 minims (gm. 0.50). Sixteen times this will give us approximately 2 fluidrachms (mils 8). The two last ingredients are vehicles, water being used as a solvent and diluent and syrup of lactucarium as a pleasant excipient with very feeble medicinal power. The dose of these, therefore, is unimportant. Of water we use a convenient quantity to insure solution of the potassium salt, say \ fluidounce (mils 15). The vehicle last to be added may ha\e its quantity definitely expressed, being the difference between the sum of other liquids in the mixture and the total desired bulk; but a simpler procedure is to order sufficient of the vehicle to be added to make up the total — (juantuvt sufficit (q. s.) ad (up to) fgij (mils 60). We then have "Whenever we order the same quantity of each of two ingredients, we may use the abbreviation aa,' meaning of each. Had we made the quantity of water in the above the same as that of the spirit of nitrous ether we could have written them thus: Aquse aa foij or 8 4. The names and quaiitities of ingredients having been determined, the next step is to give the directions to the compounder (third part of prescription). In this case we need only to direct that the substances be mixed, leavmg to the compounder's art the precise order or method to be followed. We, therefore, simply use the abbreviation of Misce, — ■ M., which is placed either to the right on a line with the name of last ingredient or to the left on a line below. CONSTRUCTION OF PRESCRIPTIONS. Dentifrices. — If we desire to T\Tite a prescription for a tooth powder, we consider first the essential qualities of the ingredients which should enter into it. Ordinarily we want a tooth powder to be: This formula is simply suggestive and admits of any desired modification or addition. Other ingredients and other proportions of these ingredients will be employed at pleasure. If we analyze the qualities of such a combination we find the value of each ingredient to be distinct, as here indicated: Crela prceparata is antacid and slightly abrasive. Sapo is alkaUne, detergent and antiseptic. Oleum gaultherice is a flavoring agent. It will be noticed that the Latin names of ingredients, and their adjectives, are given in the genitive case. The reason for this appears in the English version of the formula, the reading being: Take ten ounces of prepared chalk, etc. The antacids that serve the same purpose as prepared chalk, but which are less abrasive, are magnesium oxide, magnesium carbonate, sodium bicarbonate and borax, the last-named being also antiseptic. Powdered pumice and charcoal are too gritty and harsh for continued use. They may injure both the gums and the enamel, and they are, therefore, to be discarded from our formulas. it is not an antacid. The antiseptics, other than soap, that may be employed, are borax, resorcin, naphtol and boric acid. The last named may be combined with sufficient antacid to leave the reaction of the mouth alkaline or neutral. The flavoring agents include any of the pleasant volatile oils, or powdered drugs containing them — e. g., powdered cinnamon. Some of the volatile oils are costly, and, therefore, not commonly used. Oil of rose is the most expensive. These oils are not included for any medicinal effect, but only as flavoring agents; therefore they are used in very small quantity. staining exposed dentine. If the dentifrice is preferred in form of a paste, sufficient glycerin may be added, but syrup or honey are to be avoided on account of being readily fermentable. For the same reason sugar is inferior as a sweetening agent. Saccharine may be used, as it does not ferment, and, being about 500 times sweeter than cane-sugar, a small quantity will suffice. Anyone desiring his own special formula for a dentifrice can easily attain his object through a little experimentation with the substances here suggested, and the effort will be profitably expended. The thought should be prominent, however, that strong antiseptics are not constantly needed in normal conditions; and the more thoroughly the mouth and teeth are habitually cleansed the less will they be required. 6. To stimulate nutrition of the mucous membrane. Many agents are employed to accomplish these purposes, and the possible combinations are without number. But it may be stated as a cardinal rule, that mouth washes should possess antacid and antiseptic properties. It is impossible even in health to maintain a strictly aseptic condition of the mouth, while in disease, local or general, efforts are still less availing. It is often essential, therefore, that an antiseptic be freely emplo\'ed, always, however, with due appreciation of the harm that may follow the improper use of the stronger agents. Some agents addressed to a single purpose (as a detergent or an astringent) may be used alone in aqueous solution. Alcohol is not a suitable vehicle in mouth-washes unless its astringent action is desired, but its aid as a solvent may be necessary. In any case it must always be diluted. efficiency, and safety to the soft tissues. Certain agents, including creosote, borax and boric acid, are regarded as quite efficient in a saturated aqueous solution and may be used freely without harming the tissues; but phenol, corrosive sublimate, chloride of zinc and formaldehyde would be very irritating in saturated solution. They must be very largely diluted for use in mouth washes. One of the most efficient agents is phenol, but it should not be used stronger than 1 per cent.; and, though it is only very slightly acid in reaction, it is well to use an alkali with it as follows: The excellent work of Dr. W. D. Miller has shown benzoic acid and salicylic acid to be among our most efficient mouth antiseptics when used in 1 per cent, solution; but they are only slighty soluble in water, requiring 275 and 4()0 parts respectively, and they are acid in reaction. It is found, how^ever, that with the aid of borax a 1 per cent, alkaline solution of either of these may be prepared ; although it is probable that their antiseptic power is less in an alkaline solution. A saturated aqueous solution of borax, with 1 per cent, of either salicylic or benzoic acid added, is presented in the following: Flavoring agents may be used in the above at pleasure, in the form of medicated waters, such as aqua cinnamomi, or a little volatile oil. Creosote may be ordered in its official preparation: ABBREVIATED TERMS USED IN PRESCRIPTIONS. The use of abbreviations in the names of ingredients and in the directions to the patient is to be discouraged. The following list is intended more for reference in interpreting abbreviated prescriptions than for use in writing. A poisox may be defined to be a substance which, when introduced into the body, causes disease or death. But, in accepting this definition, foreign bodies or agents that act mechanically must be excluded, as, for example, a bullet. Certain substances also that produce disease in the system are not usually classed among poisons. Of these there are: in coiuse of the disease. ^Yith the recognition of the definite organisms that cause the several infectious diseases the term virus has fallen somewhat into disuse. In its place we have the more definite terms of hacteriinn, as the cause, and toxin, a poisonous product of the growth of the bacterium. [Antitoxin is a substance formed in the body as a reactionary protection against the action of a toxin of a disease. The presence of a toxin is necessary to stimulate the formation of the antitoxin which is capable of neutralizing it. The most familiar example of an antitoxin is that of diphtheria, which is prepared in the blood of the horse and used to neutralize the toxin of the disease in the human being.] Ptomains are basic organic compounds formed by the action of bacteria upon nitrogenous matter. Some are poisonous, and some resemble vegetable alkaloids in their action. overdose or in concentrated form, produce disease or death. The law recognizes the responsibility that attaches to the sale of poisons, and requires, in most communities, that all poisons, except those dispensed upon a physician's prescription, shall be distinctly labeled, and, in case of the more powerful substances, that a record shall be made of the sale. 290 POISONS system attacked, and character of symptoms produced. Thus arsenic, one of the most destructive poisons, acts slowly, while carbolic acid may cause death in a very short time, as is true also of hydrocyanic acid. Strychnine causes frightful convulsions, while morphine produces coma. The simple outline here given serves to aid in grouping poisons according to site of action: Concerning abortives, it should be noted that they are really irritants. Among other effects they may disturb the gravid uterus, but this is only one of the dangers of their action. As a class they must be regarded as very dangerous agents and at the same time uncertain as to any special action. 1. Failure of Circulation. — Syncope is sudden failure of the circulation, due to depression of the heart from various causes. It may be temporary, as in case of ordinary fainting, or it may be complete, due to paralysis of the heart. heart, as occurs in fatal cases of acute infectious diseases. 2. Failure of Eespiration. — Asphyxia is the condition of non-oxygenation of the blood. It may be caused by complete shutting off of the air (apnea), as in drowning, or it may be due to the displacement of oxygen by other gases. It may be partial or complete. 3. Paralysis of Brain Centers. — Coma is a paralysis of the conscious and the reflex centers of the brain. It may be caused by pressure, as in apoplexy, or it may be due to the action of a narcotic. t There can be no objection to the use of water in sulphuric acid poisoning, if sufficient is employed. In mixing 100 c.c. of water at 70° F. with 10 c.c. of sulphuric acid, the temperature increased to only 111° F.; and in mixing 200 c.c. of water (a glassful) with 10 c.c. of sulphuric acid, the temperature increased to only 94° F. J This is the Ferri Hydroxidum, U. S. P. To prepare it freshly use tincture of chloride of iron, Monsel's solution, or solution of tersulphate of iron (any solution of & ferric salt) and milk of magnesia. Dilute the iron solution with several times as much water, also the milk of magnesia with an equal quantity. Mix the two and administer freely at once, giving one-half to one glassful (100 to 200 mils.) of the mixture. [Water of ammonia may be substituted for the milk of magnesia, but the product requires washing to remove the sharp taste and odor of ammonia.] * An atmosphere containing 1 to 2 per cent, of carbonic anhydride, with a corresponding diminution of oxygen, is poisonous; with 5 to 10 per cent, of carbonic anhydride, and oxygen correspondingly lessened, death will occur, while it requires 10 to 20 per cent, to extinguish a flame. hemoglobin 200 times more readily than does oxygen. J Brunton and Strieker found that animals which had received a dose of chloral that would certainly kill them if they were left exposed, recovered when wrapped up in cotton-wool, and if the dose were increased so as to kill the animal even when thus wrapped up, it could still be kept alive by being put into a warm place so as to keep up its temperature artificially. A still larger dose was fatal. shouting I Prompt emesis by mustard or I sulphate of zinc; follow by { albumin or milk, after which induce further emesis and pur- t The principle of forced respiration, as practised in physiological experiments was applied to the treatment of opium poisoning by the late Dr. George E. Fell, of Buffalo, N. Y. The apparatus used consists of bellows, face-mask and the necessary rubber tubes, with stopcock arranged to facilitate imitation of the natural respiratory rhythm, and to allow the addition of oxygen to the inspired air. Dr. Fell employed the method in eleven cases that seemed hopeless with the use of ordinary means of treatment and in three cases that were absolutely hopeless. Of the eleven cases eight were saved. The puhnotor is an apparatus that supplies oxygen in connection with forced respiration. In expert hands it is efl5cient, but is not so commonly available as ordinary artificial respiration. Sustain circulation; strychnine, caffeine, external heat and friction; digitalis if heart failure threatens; strong infusion of every five minutes as antidote and to induce emesis; if at hand crude acid French oil of turpentine, or, as a substitute for it, old oxidized oil of turpentine, and follow by a quick saline Zinc sulphate Severe gastric irritation, Solution of common salt freely; vomiting, convulsions; albumin; mucilaginous drinks; later diarrhea other treatment as the case	118,707	common-pile/pre_1929_books_filtered	dentalmateriamed00long	public_library	public_library_1929_dolma-0013.json.gz:1245	https://archive.org/download/dentalmateriamed00long/dentalmateriamed00long_djvu.txt
brLcXyIK2dN-lNgN	OER by Subject Directory	169 Mechanical Engineering Courses Hydraulics and Electrical Control of Hydraulic Systems by Jim Pytel (CC BY-NC). This collection of instructional resources is intended to support teaching the “Hydraulics and Electrical Control of Hydraulic Systems” class using the flipped classroom format where lecture content is placed online and all class time is re-purposed into a hands on workshops or lab activities. Intro to Motor Controls by Moke, Dale (CC BY). Mechanical and electromagnetic control systems for both AC and DC systems will be studied. Ladder logic diagrams, starting and relay equipment used in control systems will be introduced. Motor Controls by Waymyers, James A (CC BY). This course covers the following topics: Electrical Quantities, Electrical Tools, Electrical Test Instruments, Electrical Symbols and Diagrams, Control Logic, Alternating Current Motors and Transformers, Contractors and Magnetic Motor Starters, Control Devices, Timers, and Common Control Circuits. Motors and Controls by Northeastern Junior College (CC BY). This course contains materials to help the student to study, construct, test, and evaluate basic industrial control systems, including AC/DC motors, stepper motors, power sources, generators, tachometers, line diagrams and logic functions. Covers safety standards and preventive maintenance. Images Electronics by various (CC BY-NC). A collection of interactive learning objects that focus on concepts that cover a broad-based electromechanical program. Resources are divided into the following categories: AC Electronics, Automation, DC Electronics, Digital, Generators / Distribution, Hydraulics, Ladder / PLCs, Mechanical Drives, Mechanical Linkages, Electric Motors, Pneumatics, Process Control, Safety, Sensors, Solid State, Information and Communications Technologies, and Variable Speed Drives. Journals Programmable Logic Controller by Luiz Affonso Guedes (CC BY-NC-SA). An open access peer-reviewed publication on programmable logic controllers. Each chapter is available for download as a PDF. Textbooks Applied Fluid Mechanics Lab Manual by Habib Ahmari and Shah Md Imran Kabir (CC-BY). Basic engineering knowledge about fluid mechanics is required in various sectors of water resources engineering, such as designing hydraulic structure on any riverine environments and flood mitigation process. The objective of this book is to enable students to understand fundamental concepts in the field of fluid mechanics and apply those concepts in practice. Applied Fluid Mechanics Lab Manual is designed to enhance civil engineering students’ understanding and knowledge of experimental methods and basic principles of fluid mechanics. The ten experiments in this lab manual provide an overview of widely used terms and phenomena of fluid mechanics and open channel flow, which are required for solving engineering problems. Basics of Fluid Mechanics [PDF] by Dr. Genick Bar-Meir (CC BY-NC-SA). This book describes the fundamentals of fluid mechanics phenomena for engineers and others. This book is designed to replace all introductory textbook(s) or instructor’s notes for the fluid mechanics in undergraduate classes for engineering/science students but also for technical peoples. It is hoped that the book could be used as a reference book for people who have at least some basics knowledge of science areas such as calculus, physics, etc. Electromagnetics Book 1 and Book 2 by Steven W. Ellingson (CC BY-SA). This is a 216-page peer-reviewed open textbook designed especially for electrical engineering students in the third year of a bachelor of science degree program. It is intended as the primary textbook for the second semester of a two-semester undergraduate engineering electromagnetics sequence. The book addresses magnetic force and the Biot-Savart law; general and lossy media; parallel plate and rectangular waveguides; parallel wire, microstrip, and coaxial transmission lines; AC current flow and skin depth; reflection and transmission at planar boundaries; fields in parallel plate, parallel wire, and microstrip transmission lines; optical fiber; and radiation and antennas. Engineering Mechanics for Structures by Professor Louis Bucciarelli (CC BY-NC-SA). This text explores the mechanics of solids and statics as well as the strength of materials and elasticity theory. In addition to introducing the fundamentals of structural analysis, it combines and applies important concepts in engineering mechanics. Its many design exercises encourage creative student initiative and systems thinking. A Guide to MATLAB for ME 160 by Austin Bray and Reza Montazami (CC BY-NC-SA). This textbook provides an introduction to the MATLAB programming language for first-year mechanical engineering students enrolled in ME 160 at Iowa State University. Designed to follow the content taught in class, this book provides a supplement to in-class learning that is presented at a level that is understandable to a student with no prior experience coding. Topics include commands, MATRIX operations, writing scripts, graphing in MATLAB, graphical user interface, functions and function handles, inputting and outputting data, and projects. Introduction to Mechanical Engineering Design by Jacqulyn A. Baughman (CC BY-SA). A collection of readings and exercises aligned with the course, ME 270, Introduction to Mechanical Engineering Design, at Iowa State University. This course provides an overview of mechanical engineering design with applications to thermal and mechanical systems, and an introduction to current design practices used in industry. As part of the course design, learners will complete a semester-long team project focused on addressing societal needs. Videos Fluid Mechanics Video Series by EdUniPhysicsAstro (CC BY-NC). A collection of YouTube videos on different topics related to fluid mechanics.	1,089	common-pile/pressbooks_filtered	https://pressbooks.saskpolytech.ca/oerdiscipline/chapter/mechanical-engineering/	pressbooks	pressbooks-0000.json.gz:51812	https://pressbooks.saskpolytech.ca/oerdiscipline/chapter/mechanical-engineering/
H-RSRtdspUf7366C	Geology of the New York City (Catskill) aqueduct; studies in applied geology covering problems encountered in explorations along the line of the aqueduct from the Catskill Mountains to New York City, by Charles P. Berkey.	STUDIES IN APPLIED GEOLOGY COVERING PROBLEMS ENCOUNTERED IN EXPLORATIONS ALONG THE LINE OF THE AQUEDUCT FROM THE CATSKILL MOUNTAINS TO NEW YORK CITY 915 Albert Vander Veer M.D. M.A. Ph.D. LL.D. Albany 911 Edward Lauterbach M.A. LL.D. First Assistant Charles F. Wheelock B.S. LL.D. Second Assistant Thomas E. Finegan M.A. Pd.D. Third Assistant Commissioner of Education Sir: The extraordinary engineering operations which have been undertaken in the effort to provide the city of New York with an adequate waUr supply have illuminated in most unexpected manner the geological .structure and history of the region of the Hudson valley south of the Catskill mountains. So broad has been the scientific scope of this engineering problem and so direct its dependence on geological structure that the Commissioners of the New York City Board of Water Supply early found it of essential moment to enlist in their service a corps of trained geologists. In 1909 an agreement was effected between the Board of Water Supply and the State Geologist, in pursuance of which the geological data acquired in the preliminary and final surveys for the aqueduct were intrusted to Dr Charles P. Berkey, a member of the staff of the board as well as of the geological survey, for summation and presentation of their hroader and more important bearings. I transmit to you herewith Dr Berkey's report thereupon, entitled Geology of the New York City (Catskill) Aqueduct. It is a document of high value not only in enlarging and perfecting our knowledge of the geological structure of the commercial center of the United States, but its data and conclusions must prove of profound importance to all large engineering and architectural propositions concerned with the region of the lower Hudson valley. AQUEDUCT STUDIES IN APPLIED GEOLOGY COVERING PROBLEMS ENCOUNTERED IN EXPLORATIONS ALONG THE LINE OF THE AQUEDUCT FROM THE CATSKILL MOUNTAINS TO NEW YORK CITY INTRODUCTION AND ACKNOWLEDGMENT It is the writer's hope that the series of studies brought together in this bulletin may help to effect a wider appreciation of the practical usefulness of geology. The volume contains a summary of the local geologic facts and the general principles found helpful in solving some of the problems encountered in a single great engineering enterprise. The summary is accompanied by brief discussions of the methods employed and of the final results or conclusions reached. It is therefore essentially a study in applied geology. Seldom has so favorable an opportunity been afforded to follow extensive exploratory work and check geologic hypothesis or theory by subsequent proof. And still more seldom have engineers in charge of similar works so fully appreciated the value of geologic investigations and the extent to which they can be utilized as a guide. More credit is due to Mr J. Waldo Smith, chief engineer of the Board of Water Supply of the City of New York, than to any one else for appreciating the importance of the geologic complexity of NEW YORK STATE MUSEUM the Catskill Aqueduct problem. His exceptional insight into its nature led to the adoption of measures in this direction that are now proved to have been fully justified. A staff of geologists has been maintained. From time to time engineers of the regular staff who have shown unusual aptitude in such investigations have been assigned to special duty on geologic exploratory work. In the preliminary investigations of the Northern Aqueduct, Division Engineer James F. Sanborn was very intimately connected with the geologic work. With him the writer worked out many field studies that later formed the basis of advisory reports, covering locations, kinds of explorations to be made, and interpretations of data. No one has had a better grasp of both the geologic and the engineering aspects than Mr Sanborn. It is with great pleasure that the writer acknowledges many valuable suggestions and much help through association with him. In the later exploratory work within the city similar service has been rendered by Mr John R. Healey, who has much to do with the geologic detail of the delivery conduit data. The consulting geologists employed by the board were Professors James F. Kemp, W. O. Crosby and the writer. A special debt is acknowledged to Prof. James F. Kemp, consulting geologist of the board, whose confidence in the writer's work originally brought him into touch with these investigations as an assistant, and with whom since that time many joint reports to the board have been written. Valuable advice and assistance in arranging for the issue of this report has been given by Department Engineer Alfred D. Flinn of Headquarters Department. For some of the corrections and suggestions special acknowledgment is made to Department Engineer Thaddeus Merrimar . The department engineers, Robert Ridgway of the Northern Aqueduct, Carlton E. Davis of the Reservoir, Merritt H. Smith, formerly of the Southern Aqueduct, Frank E. Winsor of the Southern Aqueduct, William W. Brush and Walter E. Spear of the City Delivery have given every facility for gathering geologic data within their territory and have contributed largely to the better understanding of their special fields. The geologic matter relating to special problems has been worked out with the aid of the division engineers in direct charge in the field. Among these must be mentioned L. White of the Esopua division, William E. Swift of the Hudson river division, A. A. Sproul of the Peekskill division, Lawrence C. Brink of the Wall- York city delivery division. The data included in the tabulation of this bulletin have been gathered largely by others. Many of the explanations and conclusions are the outgrowth of the work of engineer and geologist, together. A large number of associates are engaged on this public work in such relations to one another that the individuality of each is obscured in the common effort to reach an enviable efficiency and success for the whole enterprise. The combined efforts of many, unselfishly given, have thus brought together a total far in excess of what any one individual could accomplish. Acknowledgments "should therefore be made to those members of the staff of the Board of Water Supply who can not in the nature of the case be mentioned by name. Were it not for their cooperation the great mass of data here summarized could not have been compiled. Charles P. Berkey Special Geologist, New York State Geological Survey; Consulting Geologist New York City Board of Water Supply Columbia University, New York City November i, iqio CATSKILL WATER SUPPLY PROJECT New York city obtains its chief water supply from the Croton river watershed. Other sources1 now drawn upon are less important although some of them, such as the Long Island underground supply, are capable of considerable additional development. The average daily consumption of Croton water was approximately 324,ooo,ooo2 gallons for 1907. At the present rate of increase of population the consequent daily increase in consumption of water is 15,000,000 gallons in each succeeding year. The entire daily flow of water in the Croton river for the 18 years from 1879 to l%97 averaged only 348,000,000 gallons. About 10,000,000 gallons per day is lost by evaporation and seepage from existing reservoirs. The records for 40 years, from 1868 to 1907 make a somewhat better showing. Making no allowance for evaporation the average flow amounts to 402,000,000 gallons. With due allowance for evaporation,3 however, this only increases the daily supply as now planned by about 47,000,000 gallons. That is, the possible total additional water within the Croton watershed would suffice for only three years' growth of the city. Much of this additional water belongs to periods of excessive precipitation. To save it would require additional storage facilities for 3,05,000,000,000 gallons, and, it is estimated, would probably cost $150,000,000. 145,000,000 gallons daily in 1007. 2 The figures used here as to consumption and capacity and available supply are taken from the printed statements of the commissioners of the New York City Board of Water Supply in a circular dated April 16, 1908, and are based upon the investigation and reports of the corps of engineers headed by J. Waldo Smith, chief engineer, John R. Freeman and William H. Burr, consulting engineers. The reports of this commission and various others that have had the responsibility of investigating the future supplies for New York city have been drawn upon freely for such data. 3 The average rainfall for the past 40 years is about 49 inches per year. Only about 48 per cent of this runs into the streams. The rest evaporates or is absorbed by the vegetation or joins underground supplies that do not again appear at the surface in the district. Taking into account the small relief possible in this direction and the certainty that in less than five years the demands of the city will be greater than the total capacity of the Croton watershed, it is clear that some other source of large and permanent supply is an absolute necessity. In the search for such additional sources, there has been much careful work done by able commissioners.1 In the meantime, residents of certain districts where there are possible supplies have taken steps by legislative action to effectually- prevent New York city encroaching upon their territory. Criticisms3 of all kinds largely by those only partially informed as to the magnitude and complexity of the problem and partly by those ignorant of the simplest factors in its solution, have been kept perpetually before the public. One needs only a slight acquaintance with such public works to realize that it is much easier and more common to criticize and raise the cry of corruption or incompetence than it is to give really valuable advice or solve a real problem or carry an enterprise i «f the most vital public importance to a successful issue. It is sufficient here to observe that exhaustive studies of the whole question of water supply by competent men have resulted in a practically unanimous conclusion that the streams of the Catskill mountains are the most satisfactory, economical, reliable, abundant and available future source of water. 1 The Report of John R. Freeman C. E., 1899-1900; Report of the BurrHerring-Freeman Commission, 1902-4; the Studies of the Department of Water Supply, Gas and Electricity, 1902-4 ; Investigations of the Board of Water Supply, 1905 to the present time. 3 The commonest suggestions neglect the question of permanence or constancy of supply. The following sources are often mentioned, (a) Lake George, forgetting that this beautiful lake has an abnormally small watershed and could never figure as a large permanent s upply ; (b) artesian wells, ignoring the fact that with the exception of certain portions of Long Island there is almost no artesian capacity, and on Manhattan and the mainland the crystalline rocks make such development useless; (c) Lake Ontario, apparently overlooking the great distance (400 miles) and the many other complications that this international water body involves; (e) Dutchess county, where the city is prohibited by legislative enactment; (0 the Hudson river, ignoring the fact that the Hudson is an estuary of the sea with brackish water of a very impure quality and wholly unfit for domestic uses. It is, however, worth while to note that Hudson river water is sure to be used more and more extensively for fire protection and similar purposes in the more densely populated portions of the city by means of an entirely different system of conduits. This is one of the most promising directions of relief looking to the more distant future. The Catskill supply will furnish over 500,000,000 gallons of . water daily and was estimated to cost $161,857,000. That is, the additional supplies from the Catskills as planned will, when completed, be sufficient for the increasing demands of the growing city, ; for the next 35 years. And some of it may be badly needed long before it can possibly be delivered. 660 000 000 1 The subdivisions and proposed locations given here are taken chiefly from the Report of the Board of Water Supply of the City of New York to the Board of Estimate and Apportionment, October 9, 1905. 2 Estimates are much more complete for the Esopus, which it is planned to develop first, than for any other streams ; and it must be understood that the figures are subject to revision dependent upon modifications of original plans to meet the conditions that develop upon more elaborate investigation. 3 Preparations are to be made for storage of 120,000,000.000 gallons of water on the Esopus, but a part of this capacity is intended to accommodate supplies drawn from other sources than Esopus creek itself. GEOLOGY OF THE NEW YORK CITY AQUEDUCT The evident certainty that present supplies from the Croton and Long Island will be very inadequate long before the Catskill system can be completed has influenced the adoption of plans contemplating the construction of certain parts in advance of the rest. To begin with, only the Esopus watershed is to be developed by the construction of the great Ashokan dam at Olive Bridge making the reservoir of full capacity. At the same time that portion of the aqueduct between the Ashokan dam and the present Croton reservoir is to be completed in advance of other parts so as to make it possible to turn additional supplies into the Croton system, the capacity of the present Croton aqueducts being somewhat in excess of the Croton storage in dry years. It is furthermore desirable that increased storage capacity should be secured much nearer to New York city, and with that end in view Kensico reservoir is to be greatly enlarged. It is estimated that this may be made to hold 50 days' supply of 500,000,000 gallons daily. The development of the Catskill system is being carried on by the Board of Water Supply, which was appointed by Mayor McClellan, as provided in chapter 724, of the laws of 1905. The present board consists of John A. Bensel, president, Charles N. Chadwick and Charles A. Shaw. The Engineering Bureau of the Board is in charge of J. Waldo Smith, as chief engineer, Merritt H. Smith, as deputy chief engineer and Thaddeus Merriman, assistant to chief engineer. Influenced doubtless in large part by the unity of certain portions of the project, either because their essential engineering features are distinct, or because their construction is more urgent, or in order to facilitate the work of supervision of so great an undertaking, the following departments have been created : D. Flinn, department engineer. 2 Reservoir department. In charge of development of the Catskill watershed and the construction of the various dams and reservoirs. Carlton E. Davis, department engineer. 3 Northern aqueduct department. In charge of the construction of full capacity aqueduct from the Ashokan dam (60 miles) to Hunters brook in the Croton system. Robert Ridgway, department engineer. to Hill View reservoir on the northern limits of New York city and of the storage reservoirs and filtration work. Merritt H. Smith, and more recently F. E. Winsor, department engineer. 5 Long Island department, in charge of the development of the underground water supply of Long Island. A plan looking toward this end has been prepared and approved by the city authorities and is now being reviewed by the State Water Supply Commission. 6 City aqueduct division. In charge of the delivery of water from Hill View reservoir throughout Greater New York. Originally in charge of W. W. Brush, now under Walter E. Spear, as department engineer. Departments are further divided into " divisions " each in charge of a division engineer and a full corps of assistants. The subdivisions of these larger units, although primarily based upon convenience and efficiency of engineering supervision, coincides rather closely with the larger geologic problems included in this bulletin. Generalities of construction The chief types of structure projected include (i) masonry dams, (2) earth dikes with core walls, (3) "cut and cover" aqueduct through country of about the elevation of hydraulic grade, (4) tunnels through mountains or ridges that are too high, and (5) pressure tunnels under valleys or gorges that are too low. 13.9 miles of tunnel at grade 17.3 miles of pressure tunnel below grade 34 shafts of aggregate depth of 14,723 feet. 6.3 miles of steel pipes making Allowing for contingencies and costs for engineering supervision the system is estimated to cost $176,000,000 and many years will be required for its completion. The present plans, however, contemplate only the immediate development of the Esopus watershed, the storage reservoirs near the city and the main aqueduct to the various points of delivery within the city limits. It is expected that part of this additional supply of water will be available by the year 1913, or early in 1914. PROBLEMS ENCOUNTERED IN THE PROJECT W'hen the Ashokan reservoir is filled the surface of the stored waters will stand 590 feet above the sea. Hill View reservoir on the northern borders of New York city will have an elevation of 295 feet. The distance between these two points is nearly 75 miles in direct line. The contour of the country and other exigencies of construction will increase this to approximately 92 miles. A main distributary conduit in New York city will add 18 miles more. The destination of the water therefore before distribution begins is 300 feet lower than its starting point. This is sufficient head to permit gravitational flow and a self-delivering system. If the hydraulic gradient can be maintained it would evidently constitute a decided advantage. The plans have therefore from the beginning contemplated such construction. It means then that a flowing grade must be maintained in all tunnels or channels or tubes and that when a depression has to be crossed the pressure must be maintained in some sort of a conduit so that the water may rise again to a suitable level on the other side. The difficulties of accomplishing this in a work of such magnitude are not at first apparent. The full significance of the undertaking can be realized only after a study of the country through which the aqueduct must be carried. It then resolves itself into a series of problems, each one having its own characteristics and peculiar difficulties and methods of solution and each requiring a thorough understanding of the topographic features of the vicinity and a working knowledge of geologic conditions. General questions It is sufficient at this point to call attention to the facts of the topographic map and point out only the most general physiographic features that may at once be seen to materially modify the simplicity of the line. For example, one has scarcely left the great reservoir, with water flowing at 580-90 feet above tide, before the broad Rondout valley is reached, with a width of 4/. miles nowhere at great enough elevation to carry the aqueduct at grade. If it is to be crossed at all, and it must be crossed to reach New York city, some special means must be devised. If a trestle be proposed, one finds that it would have to be 4>j miles long (24,000 feet), and in some places 300 feet high, and at all points large enough and strong enough to carry a stream of water capable of delivering 500,000,000 gallons daily — a stream that if confined in a tube of cylindrical form would have a diameter of about 15 feet. A steel tube might be laid to carry the water across and deliver it again at flowing grade, but here one is met with the fact that it would require a tube of unprecedented size and strength and if divided into a number of smaller ones the cost would be greater than that of a tunnel in solid rock. The other alternative is to make a tunnel deep enough in bed rock to lie beneath surface weaknesses and superficial gorges and in it carry the water under pressure to the opposite side of the valley. This is the plan that seems best suited to the magnitude of the undertaking and would seem to promise most permanent construction. But no sooner is this conclusion reached than it is realized that there are now several hitherto unregarded features that assume immediate and controlling importance. Some of these, for example, are (1) the possibility of old stream gorges that are buried beneath the soil, (2) the position of these old channels and their depth, (3) the kinds of rock in the valley, (4) their character for construction and permanence, (5) the possible interference of underground water circulation, (6) the possible excessive losses of water through porosity of strata, (7) the proper depth at which the tunnel should be placed, (8) the kinds of strata, and their respective amounts that will be cut at the chosen depth, (9) the position and character of the weak spots with an estimate of their influence on the practicability of the tunnel proposition. Then after these have all been considered the whole situation must be interpreted and translated into such practical engineering terms as whether or not the tunnel method is practicable, and at what point and at what depth it should cross the valley, and at what points still further exploration would add data of value in correcting estimates and governing construction and controlling contracts. This is a general view of one case, the first one of any large proportions in following down the aqueduct. • There are many others. In nearly all of them the importance of geologic questions is prominent. Many of them, of course, are of the simplest sort, but, on the other hand, some are among the most obscure and evasive problems of the science. And they do not become any easier simply to know that they must ultimately be stated in terms precise enough for the use of engineers, and to know furthermore that the real facts are to be laid bare when construction begins and as it progresses. But from another viewpoint it may be regarded as an exceptionally fine opportunity to study applied geology in its best form and to see the intimate interrelationship between an engineering enterprise of great public utility and a commonly considered more or less obscure science. The services of geology have been seldom so consistently employed in earlier undertakings of similar character. It is to be hoped that the accompanying illustrations of the practical application of geologic knowledge and facts to engineering plans and practice may add to the appreciation of the commonness and variety of such service in many everyday affairs. Furthermore, this unique enterprise, the like of which for magnitude and complexity has never before been attempted, has given to those whose good fortune has brought them into working relations with its problems, the opportunity of a generation in their chosen field.1 The success stages from isolated observations, inference, hypothesis, theory, conclusions, and fully proven facts are all represented. The steps more or less fully coincide with the degree of confidence observable in the tone of advisory reports to the engineers in charge — representing suggestions, recommendations, or specific advice. Tt is one of the cherished wishes of the writer of this bulletin that some of these problems may be presented in such manner as to serve a distinct educational purpose. For this reason in part, deeming it even of greater importance than the mere enumeration of newly discovered facts, the writer has chosen to treat the subject from the standpoint of an instructor illustrating the development of working conclusions. Tt is certain that not all readers have the same degree of preparation or acquaintance with the subjectmatter, and it may therefore be useful to include many things that some may well pass by. No excuse is offered except that such method of treatment, in behalf of the general intelligent public that it is hoped to reach, seems to the author to be advisable. 1 W. O. Crosby of the Massachusetts Institute of Technology, James F. Kemp and Charles P. Berkey of Columbia University have constituted tlie staff of consulting- geologists throughout most of the exploratory work. Other problems The foregoing observations apply likewise to the other larger problems of the aqueduct line. A list of the larger ones requiring extensive exploration and illustrating geologic application in their solution are given below : 16 New York city delivery tunnel In addition to these there are several questions of general bearing in which the chief lines of argument and the chief basis of conclusion are essentially geologic. Although little wholly new data is yet available on these particular questions from any direct work of the aqueduct, yet it will add materially to an appreciation of the far-reaching influence of established geologic data and geologic reasoning to enumerate some of them : 22 Structural materials Each of these problems or questions or topics is discussed separately, so far as practicable. By adopting this plan, of course there is a tendency to repetition but this to a certain extent is unavoidable. Some of it is overcome by suitable references to preceding discussions. Where such cross reference is too cumbersome, the items are repeated in preference to leaving the case obscure. Thus it is hoped to make each case a unit, and the whole series useful and understandable. Gathering data In the accumulation of data all the members of the engineering corps1 as well as the men acting only in a consulting capacity have taken part. Necessarily the bulk of the exact data has been gathered by the men all the time on the ground and whose duty it was to superintend explorations. The care and intelligence with which this has been done is notable. A considerable proportion of the labor of manipulating the accumulated data and interpreting it so as to reach an explanation of conditions and formulate conclusions has been assumed by the consulting men. Too much credit can not be given to the heads of departments and divisions for the open-handed way in which all needed facts were held available at all times for comparison and guidance toward sound conclusions. The information upon which investigations have been initiated have been chiefly the following: 5 Reports of special commissions on water supply 1 In this work, no group of men have had so direct responsibility as the division engineers. The success with which so many complicated explorations were carried out is chiefly due to their constant care and foresight and perseverance and the able assistance of their staff. Those who have had especially important divisions for the geological problems involved are given due credit in the discussions of part 2, of this bulletin. It is easy, however, to neglect sufficiently full acknowledgment of their services in gathering and formulating data of this kind. Among those having charge of the most important exploratory work the following names should appear: William E. Swift, in charge of the Hudson river explorations. William W. Brush, in charge of the early New York city explorations. Lazarus White, in charge of the Rondout valley explorations. Lawrence C. Brink, in charge of the Wallkill division explorations. J. S. Langthorn, in charge of the exploratory work at the Ashokan Reservoir. Some of these are printed reports and records not directly concerned with this enterprise, but whose' information has been found useful in this field. This is especially true of the first four sources enumerated, i, 2, 3, 4. The last is a specific study with direct reference to this project. Investigations were begun from the above vantage point. The methods employed and the explorations conducted constituting the further sources of information and furnishing the complete data upon which all conclusions have been based include the following: 18 Laboratory tests of quality and behavior of materials. The mass of data accumulated from all these sources is surprising. For example, there are upward of 200 wash borings on the different proposed Hudson river crossing lines alone ; there are 69 drill borings and 177 wash borings on the site of Kensico dam; there are 69 shot and diamond drill holes on the Rondout siphon line aggregating 10.234 feet of rock core ; there are 65 drill holes of various sorts on the Moodna creek siphon aggregating in total penetration of drift over 10,000 feet: there are 106 borings, besides several pits and trenches at Ashokan dam location. At every point explorations suitable to the particular problems in hand were conducted. The whole mass of data is conveniently recorded, much of it is tabulated, some of it is represented graphically, samples of nearly all of the material are available for examination.1 and all 1 The cores of all drillings and suitable samples of all borings in drift have been saved and properly labeled and are to be permanently boused at some convenient point on tbe aqueduct line when completed. At present they are cared for at the different division offices. the conditions. But the amount of accumulated data is no more remarkable than the difficulties that have been encountered in obtaining it. For example, in the Moodna valley it has taken three to four months' time to put down a single hole to bed rock — the average time consumed for each of the 15 holes exploring the deepest portion of the valley was about 60 days. The chief trouble is caused by heavy bouldery till. In one case a boulder was penetrated for 35 feet, lying a hundred feet above bed rock. The extreme of such difficulty is, of course, encountered in the Hudson river itself, where the drill has to contend with: (1) the rise and fall of the tides, (2) the river currents, (3) a maximum of 90 feet of water, approximately 700 feet of silt, gravel, till, boulders, etc., filling the old preglacial gorge. The heavy steamboat and towing traffic has been a serious element in the problem. Probablv never anywhere have drillmen had to face so nearly insurmountable obstacles. In two years only two holes reached below a depth of 600 feet below sea level. A third, now in progress, has penetrated a depth of 768 feet without entering rock. TION AND STAGES OF DEVELOPMENT In the earlier stages of work topographic features were of most concern, and they largely controlled the selection of reservoir sites and possible lines for the aqueduct to follow. It was, however, at once recognized that tunnels would be unavoidable and studies as to the types of rock formations to be encountered were begun It was also early appreciated that the soil or drift cover is very unevenly distributed over the rock surface and that, especially in the chief valleys requiring pressure tunnels, it would be necessary to determine the profile of the rock floor. At this point wash borings were begun. But the natural limitations of the wash rig1 for penetrating drift of all kinds left the information still too indefinite. The wash rig can not penetrate hard rock. It can not wash up anything but the finer matter, and a boulder of very moderate size is almost as effectual a barrier as true rock ledge. By a combination of washing and chopping or by the use of an explosive to break or dislodge an obstruction some progress in unfavorable material may be made, but the wash rig alone, in a drift-covered region, gives only negative results. It is certain, for example, that bed rock lies at least as deep as the wash rig has penetrated, but it is not certain that it is bed rock instead of some other obstruction. Except in areas of special drift conditions,2 therefore, the wash rig was insufficient. To rely upon the process at random was clearly impossible, and to determine whether or not the results of a particular locality 1 A " wash rig " is a device composed essentially of two iron pipes, one within the other, and so mounted that the inner one can be worked up and down in sort of a churning fashion while water under considerable pressure is forced through it to the bottom and out again by the larger pipe to the surface, carrying up with the current the displaced sand and clay. As progress is made with the inner pipe the outer one is from time to time driven down and the process renewed and repeated till the hole is finished. 2 One of the most notable areas of special drift conditions is represented in the Walkhill valley Isee discussion in pt 2] where there were developed large deposits of modified drift, stratified gravel, sand and clays, lying immediately upon the bed rock floor. In this the wash bore process was eminently satisfactory, and the rapid progress made by it together with its economy made this an especially attractive method of exploration. cuiild be relied upon became involved at once with an interpretation of local glacial phenomena, especially an interpretation of the character of the local drift. In order to see the limited application of this method one needs only to point out that the majority of drift deposits in this region are stony or even bouldery, forming thick coverings in the valleys, and to call attention to the experience at two or three points. For example, at Moodna creek, the preliminary wash borings were obstructed and bed rock reported at 5 to 15 feet below the surface where afterward, by other means, it was proven to lie more than 300 feet down. Or again, in the preliminary wash borings in the Hudson, the rigs were stopped and rock bottom provisionally reported at from 25 to 200 feet below sea level, but later explorations have proven at the same point that rock bottom is more than 700 feet down. Therefore, to the " wash rig " was added the " chop drill " and the " oil-well rig " and to these, or to modifications of them,1 the success in reaching bed rock has been due. From independent field studies of a more strictly geologic nature it became clear that many of the valleys, where pressure tunnels were proposed, are of comparatively complex geologic structure and exhibit considerable variety of rock quality and condition. This then introduced and necessitated still more elaborate lines of exploration. It was not enough to know the profile of rock floor alone, it became of equal importance to penetrate the rock and obtain samples of it. So the shot drill 2 and the diamond drill 3 were employed and the drill cores preserved for identification and reference. 1 The essential features of the machines in most instances are, a high tower or support, a heavy chisel-shaped plunger that can be raised by a rope and dropped repeatedly in the hole, destroying or displacing obstructions, and which can be followed by a casing driven down as progress is made — a combination of washing, chopping and driving. 2 The shot drill, or calyx drill, is essentially a machine devised to rotate a steel tube which is so adjusted and manipulated that a supply of small chilled shot can be kept continually under the lower end as it bores into the rock. The cutting is done by the shot immediately under the edge of the tube. A core remains in the~ tube and may be recovered. Its best position is vertical. 3 The diamond drill consists essentially of a bit or crown set with black diamonds (bort) in such manner that when the bit is attached to a rotating tube a circular groove is cut into the rock. By proper attachment to jointed tubes and driving gear a hole may thus be bored at any angle and to great depth and a core recovered. These preserved cores, now aggregating many thousands of feet have been of great service in determining the precise limits of formations and consequently the geologic structure or cross section, by which detailed estimates may be guided. Even these occasionally appeared to give insufficient data. The peculiar behavior of certain holes, as, for example, one or more at Foundry brook,1 led to the suspicion that the drill had swerved from its course, following a particularly soft seam or zone, and that the results secured by it without large corrections, were wholly misleading. Tests proved that there had been a deflection. At this and many other places it later became very desirable to form some quantitative as well as qualitative opinion of the conditions existing in the underlying strata. The percentage of core saved, the rate of progress of the drill, the behavior of the drill, the condition of the core recovered, the loss of water in the hole — all these of course were considered. For more definite evidence as to porosity and perviousness, a series of carefully planned pressure tests2 were made. By shutting off connection with the walls of the hole above a certain stratum and forcing water in under pressure, it was possible to demonstrate that certain strata or certain portions were practically impervious in their natural bed, while others were much less so, and to get an idea of their relative efficiency as water carriers. For the pressure tunnels, especially, this test is a very suggestive line of investigation. 1 At Foundry brook \sce discussion of this problem in pt 2], the remarkable condition apparently shown was a reasonably substantial ledge of granitic gneiss, 50 feet, followed below by 200 feet of apparently soft sand and reported as such. No core could be recovered. So extensive a zone or bed or layer or mass is hardly conceivable considering the crystalline silicious character of the rock. Tt probably represents a steeply dipping crush zone along fault movement where the increased underground circulation has been unusually effective in producing decay. After enterins this zone the drill swerved from its initial course and kept within the soft seam. 2 The pressure test is made by means of a force pump, fitted with a gage on which the pressure is recorded, connected by a pipe to the portion of the hole to be tested, and so adjusted to a device for blockading; or damming the hole that the water pressure is confined to those portions of the walls of the hole below the dam, or between two dams if an upper and lower one are used. In this way any portion of a hole, or stratum or several beds together may be tested and the amount of water absorbed per unit of time per unit of pressure determined. This is, of course, directly related to the porosity of the rock and is approximately inversely proportional to its presumed value as an aqueduct carrier. Where the strata are especially porous and where underground or permanent ground water supplies are very extensive and where at the same time the largest or deepest pressure tunnels are projected some uneasiness has been entertained as to the extent of interference from inflowing water during construction. An attempt to form some idea of the ease of such underground circulation has been made by a systematic pumping of one or two critical holes. The results leave many factors still too obscure to draw definite conclusions. The test will be taken up again in the discussion of the Rondout siphon in part 2. Laboratory tests and experiments on materials complete the list of lines of investigation with which this bulletin is concerned. Although from the nature of the case these are elaborate and unusually complete, the more important lines are not at all new. All the methods of petrographic, chemical, and physical manipulation that seem to promise practical results of value to the success of the undertaking are followed and the data are organized and interpreted and conclusions are formulated with as great definiteness for practical bearing as other lines of investigation. GENERAL GEOLOGY OF THE REGION It will save much repetition and it is believed will altogether serve a useful purpose in maintaining unity of treatment to give an outline of the geologic features of the region in advance of the discussion of special problems. It is intended only for those not sufficiently familiar with the general geology to follow subsequent matters. The region includes some of the most complicated and obscure sections of New York geology. It is simple in almost no one of the larger branches of the subject. In physiography there is the long and involved history and the results of long continued erosion of a variable series of formations in different stages of modification as to structure and metamorphism and attitude, modified still further by subsidences and elevations, depositions and denudations, peneplanations and rejuvenations, glaciation and recent erosion — all together introducing as much complexity as can well be found in a single area. In stratigraphy the whole range of the eastern New York geologic column is represented from the oldest known formation up to and including the Middle Devonic — a succession of at least 25 distinct formations which may for convenience be treated in groups that have had similar history. Each of these formations has a constant enough character to map and regard as a physical unit. Even this classification ignores the great range of petrographic variability shown in such formations as the Highlands or Fordham gneisses. All but two or three of these formations will be cut by the tunnels of the aqueduct. In petrography the range is even greater — so great, in fact, that only an enumeration of the variations will be attempted. They include elastics, metamorphics and igneous types ; stratified and unassorted, coarse and fine, detrital and organic, marine and fresh water, homogeneous and heterogeneous, argillaceous, calcareous and silicious sediments, unmodified and thoroughly recrystallized strata ; acid and basic and intermediate intrusions ; massive and foliated crystallines — of many varieties or variations in each group. In tectonic geology an equal complexity prevails. There are regular stratifications, cross-beddings, disconformities, overlaps and unconformities ; interbeddings, lenses and wedges ; flat, warped, tilted and crumpled strata; monoclinal and isoclinal, open and closed, anticlinal and synclinal, symmetrical and overturned, horizontal and pitching folds ; joints, crevices, caves, crush zones, shear zones, and contacts; normal, thrust, dip, strike, large and small faults; veins, segregations, inclusions, dikes, sills, bosses and bysmaliths. With such variety of natural conditions it is not surprising that the problems of the aqueduct are also of great variety. No two have in all respects the same factors in control and no two can be explored and interpreted upon exactly the same lines. It will be convenient at this point to think of the surface topography by districts — not wholly distinct from each other, but still with essential differences of origin and form. From south to north they are: (a) New York-Westchester county district. The area of crystalline sediments. South of the Highlands, (b) Highlands of the Hudson (Putnam county), (c) Wallkill-Newburgh district. From the Highlands to the Shawangunk range, (d) Shawangunk range and Rondout valley, (e) Southern Catskills. All have been sculptured by the same forces and with similar vicissitudes, but the difference of history and structure and condition, already established when the physiographic forces began on the work now seen, have caused the variety of surface features indicated in the divisions made above. The more noticeable characteristics of these five districts are here given. a New York- Westchester district. The area south of the Highlands proper is characterized by a comparatively regular succession of nearly parallel ridges separated by valleys of nearly equal extent (y2 to 5 miles wide), making a surface of gently fluted aspect and of moderate relief (0-500 feet) sloping endwise toward the Hudson and the sea. The controlling factors in producing this topography are involved in a series of folded, foliated, crystalline sediments, of differing resistance to destructive agencies. b The Highland region is one of rugged features, with a range of elevation of 0-1600 feet A. T., forming mountain masses and ridges separated by very narrow valleys all having a general northeast and southwest trend across which the Hudson cuts its way in a narrow, angular gorge, forming the most constricted and crooked portion of its lower course. The bed rock is all crystalline, 1 The physiographic history of a region is not understandable without a comprehensive knowledge of its geologic features and structures and history. Tt is therefore treated in a later paragraph. with large masses of igneous intrusions and bosses. c The Wallkill-Newburgh district lying immediately north of the Highlands and extending to the Shawangunk range is a region of gently rolling contour. Most of the area along the proposed lines lies between 200 and 500 feet above the sea. There are only occasional rugged hills or short ridges, such as Snake hill and Skunnemunk. The valleys are broad and smooth and the divides are simply broad, hilly uplands. Bed rock is chiefly Hudson River slates with occasional belts of Wappinger limestone. The larger features, the trend of divides and valleys, are northeast and southwest, although this regularity is not so marked as in the preceding two districts. But the chief streams flow either northeast or southwest to the Hudson along these general lines. d The Shawangunk range and Rondout valley form a transitional unit from the complicated structural and tectonic conditions of the southerly districts to the uniform and almost undisturbed strata of the Catskills. Its southeasterly half is a mountain ridge partaking of extensive faulting and folding and represented by the Hudson River slates overlain unconformably by the thick and very resistant Shawangunk conglomerate forming high eastward-facing cliffs. Toward the northwest these disturbances diminish, the strata gradually pass deeper beneath a great succession of shales, limestones, and sandstones of the Helderbergian series, and a broad valley is eroded in the softer portions. It is limited on the northwest by the prominent and very persistent escarpment bordering the Hamilton series and forming the outer margin of the Catskill mountains. e The Catskill area is of simple structure. The strata are well bedded and lie almost flat with a gentle dip northwest. The surface features form a series of irregularly distributed escarpments, hills, valleys, cliffs, gorges and mountains, rising rapid!/ toward the west, with moderate to strong relief and reaching elevations of 2500 feet. The failure of the northeast-southwest trend of feature that is so common in all of the other districts is a marked difference. It is directly due to the flatness of the strata. 2 Stratigraphy There are no strata of prominence in association with the main aqueduct younger than Devonic age except the glacial drift. Immediately adjacent areas, however, some of which are covered by the accompanying maps, and Long Island have later formations ex- tensively developed. Such are the Triassic rocks of the New Jersey side of the Hudson below the Highlands, and the Cretaceous and Tertiary strata of the Atlantic margin on Long Island and Staten Island. The development of underground water supply on Long Island is especially concerned with these later formations, and with the modified drift deposits of the continental margin. The whole series of formations are more commonly considered in groups that exhibit certain age or physical unity and that are for the most part characteristic of certain regional belts and that coincide somewhat roughly with the physiographic divisions already noted. There is in the following description and tabulation no direct attempt to unduly emphasize this relation or to belittle the divisions recognized in the commonly adopted geologic column. It is, however, for the purpose in hand, more convenient and useful to keep clear the physical groupings, because largely these groups, instead of the more arbitrary subdivisions of age, are the units used in considering structural and applied problems. a Quaternary deposits, (i) Glacial drift. A loose mantle of soil and mixed rock matter covers the bed rock throughout the whole region except (a) here and there where the rock sticks up through (outcrops), and (b) at the most southerly margin along the coast where the glaciers seem not to have reached. Origin. This mantle is usually very different in lithologic character from the underlying rock floor. There is almost always an abrupt break between the rock floor and the overlying material. The rock floor is grooved, smoothed, and scratched as if by the moving of rock or gravel over it. The larger boulders are usually of types of rock identical with ledges lying northward at greater or less distance. Materials of exceedingly great, variety both in size and condition and lithologic character are often all piled together in the most hopelessly heterogeneous manner. These are now commonly regarded as conclusive evidence of glacial origin. There is no need of making the discussion exhaustive. It is almost universally called the " drift." Thickness. The thickness of the drift varies from almost o to approximately 500 feet. It is generally thickest in the valleys where it has simply filled many of the original depressions and obliterated much of the ruggedness of surface, the gorges and ravines and canyons of the preglacial time. Sources. It appears from an examination of the grooves and striae on bed rock, and the relationship of the different types of drift to each other, and from a comparison of the types of boulders with the ledges that may be regarded as their source, that the general ice movement was from north to south swerving along the southerly extension to east of south. Therefore it is not unusual to find abundant boulders of Palisade trap stranded in New York city or on Long Island, or boulders of the Cortlandt series, or of the gneisses of the Highlands, or, in occasional instances, of sand stones from the Catskills, or the limestones from the Helderbergs or perhaps in rarer cases even rocks from greater distance, as the Adirondack mountains. Kinds of drift. There are in the region two fundamentally different types of drift as to method of deposition. They are (a) unassorted drift (till or hardpan), and (b) modified drift (stratified or partially assorted gravels, sands, clay, etc.). The former (a) represents deposition directly from the ice sheet at its margin (terminal or marginal moraines) or beneath ("ground moraine") without enough water action to rework and assort the material. It therefore contains boulders, pebbles, sand and clay of a heterogeneous mixture of the most complex sort both as to size and character. In such deposits there is almost always sufficient intermixture of clay and rock flour of the finest sort to make a very compact and dense mass that is usually quite impervious to water. Such deposits are distributed rather unevenly over the surface and where this unevenness leaves hollows or basins, or obstructs the outlets of other depressions, they may hold water and form small lakes or ponds or swamps. This is almost universally the origin of the many thousands of lakes of the northern lake region. It is evident that material of this character, a type that commonly serves the purpose of a natural dam or reservoir, would be especially important and useful at certain places on the Catskill system. As a matter of fact, so far as geologic features are concerned, it is the chief factor in choice of location for the Ashokan dam [see discussion pt 2] and is a controlling factor in the plans for the erection of the miles of dikes at less critical margins of the reservoirs. Till is an extensively developed type but frequently passes abruptly either laterally or vertically into assorted materials of very different physical character. (b) All materials associated in origin with the glacial occupation that have been materially modified especially in the direction of an assorting of material are referred to as " modified drift " deposits. They include (1) deposits made by both water and ice together, (2) those formed by running water. (3) those laid down in stand- ing water. Or again (i ) those accumulated rapidly with very irregular supply of material at the margin of the ice-forming, hummocky or hill and kettle surface (kames, eskers), (2; those carried along valleys or general lines of drainage to a considerable distance beyond the ice margin aggrading the valley with the overload of gravels and sands (valley trains), (3) those washed out from the ice margin in more even distribution forming a gently sloping and thinning extramarginal fringe (outwash or apron plains), (4) those fine matters that are carried by glacial streams into the margins of more quiet waters, either a temporary or a permanent lake or a larger and slower stream or other body forming more perfectly assorted and more evenly stratified deposits (delta deposits), (5) those finer rock flours and clays that remain suspended longer and carry out much farther settling only in the very quiet waters of lakes 01 estuaries or temporary water bodies of this character forming the perfectly banded clays (glacial lacustrine clays). It is evident then that modified drift has in the process of its accumulation suffered chiefly a separation of fine from the coarse particles and that in most cases the fine clay filling that makes the till dense and impervious to water, has been washed out and deposited by itself in the more inaccessible deeper waters. As a result most modified drift deposits are pervious and easy water conductors, but poor or questionable ground for dikes or dams or basins [sec discussion of Ashokan dam, pt 2]. Some of them, the medium sands and gravels, furnish an excellent and already cleaned structural material for concrete or mortar, such as the Horton sand deposit, or coarser kinds may be crushed and sued before using as is done at Jones Point on the Hudson. The finer silts and clays, usually overlain by assorted sands, are abundant along the Hudson, having been deposited there at a time when the water of this estuary stood 50 to 150 feet higher than now. Recent erosive activity of the river has cut the greater proportion of the original deposits away but at many places large quantities still remain above water level in the banks and still greater quantities extend beneath the river. These deposits are the support of the brick industry of southeastern New York. The till deposits are very difficult to penetrate in making borings because of the boulders, the wash rig being almost useless. Modified drift of the medium and finer sorts is easily and cheaply penetrated, and, if it lies on bed rock, such exploration gives reliable results. have advanced and retreated repeatedly, how many times in this region is not clear. \\ ith each time of advance and retreat, the work done by it partly destroyed, or disturbed or modified or covered the earlier ones in what appears now to be a most arbitrary way (in reality, of course, in a very consistent way for the conditions that then existed). So one frequently finds a till beneath a deposit of stratified drift, or modified drift beneath till, or a succession of a still greater number of changes in almost hopeless confusion. In New York city, for example, at Manhattanville cross valley, the exposed drift above street level includes (a) at the bottom, water-marked stony till and assorted gravels, (b ) in the middle perfectly horizontal, stratified rock flour and the finest sand, (c) top, wholly unassorted bouldery till, covered by thin soil. It is evident that the most careful and accurate identification of the surface type without subsurface investigation would give, for such uses as are now being considered, thoroughly unreliable evidence as to the behavior of the whole body at this point. Therefore, a determination of the changes and quality forms an essential record. All of these types are to be found in the region, but the different grades of till and roughly modified material belonging to the kame type are more common inland. On Long Island the development of marginal modified types is extensive and more or less obscured by the advance and retreat noted above. The larger divisions recognized in deposits are (a) an early accumulation of sands and gravels, strongly developed near the western end of the island, known as the " Jameco " gravel, (b) an interglacial (retreatal) deposit of blue clays known as the " Sankaty " beds, (c) a later series of deposits, sands, clays, gravels and till, belonging to the closing stages of the ice period corresponding to the surface deposits of the larger portion of the whole region (Tisbury and Wisconsin advances). Some of these sands and gravels are important water-bearing sources for the new Brooklyn additional supply. A radically different and in some respects a much simpler interpretation1 of the Long Island deposits has been outlined by W. O. Crosby. The essential feature of his classification is the unity and simplicity of the glacial epoch. Only the moraines and associated sands and gravels of outwash origin during advance and retreat are regarded as glacial. All other deposits below and including the Sankaty clay beds he regards as preglacial. fied as Pliocene. b Tertiary and Cretaceous deposits. (2) Tertiary outliers. Deposits of Pliocene age are littoral in type [PP 44 U. S. G. S. p. 28] and are not very well differentiated (Long Island, Staten Island). Probably equivalent to the Bridget on beds of New Jersey. Certain " fluffy " sands in thin beds are assigned by Mr Veatch to the Miocene (Long Island, Staten Island). Probably equivalent to the Beacon hill deposits of New Jersey. Crosby places the Jameco gravels in the Miocene together with the Kirkwood lignitic and pyritic clays and sands. They form the chief bed rock of Long Island. 1 The writer offers both of these outlineG of the glacial and associated deposits in preference to either alone. Both Veatch and Crosby have given immensely more time to the study of these questions than any one else. It is hardly fitting for a newcomer in their field to reject either view. But because of the very great difference between the two interpretations one may be pardoned a preference. It is the writer's opinion that the simpler outline is the more tenable. It does not seem possible to establish a very complex series of stages in the glacial epoch as represented in the deposits of southeastern New York. (o) A lignitiferous sand with occasional clay beds forming the uppermost of the Cretaceous series is probably equivalent to the marl series of New Jersey. But it lacks the prominent greens and development characteristic of the region further south. Not clearly separable from the underlying formation or Matawan beds. (c) Raritan formation. Clays and sands, plastic clays, the Lloyd sand, an important water carrier lies about 200 feet below the top of the formation. Occasional leaf impressions. All of these formations, except where disturbed locally by glacial ice, dip gently seaward. The sand beds of these strata are the chief sources of underground water being developed by the new system. c Jura-Trias formations. (4) Palisade diabase. This is a thick intrusive sheet, or sill, of igneous rock of diabasic type. It is 700-1000 feet thick. It lies for the most part parallel to the bedding of the surrounding, inclosing, sedimentary rocks, and, rising gently eastward, forms a strong cliff continuously along the west bank of the Hudson for 40 miles. It varies from very fine to very coarse texture and is for the most part fresh, tough, durable, and is the source of large quantities of the most satisfactory quality of crushed stone now on the market for use in concrete. (5) Newark scries. This is a very great thickness of silicious sediments, chiefly reddish conglomerates, red and brown quartzose and feldspathic sandstones and shales. They dip gently westward and northwestward at 10-20 degrees, and are confined, in this region, to the west side of the Hudson south of the Highlands. The formation supplies " brownstone " for building purposes. d Devonic strata. (6) Cat skill formation. This formation1 is of continental type, chiefly a conglomerate. A white conglomeratic sandstone forming the uppermost portion attains its greatest thickness on Slide mountain (350 feet). It is a " coarse grained, heavy bedded, moderately hard sandstone containing disseminated pebbles of quartz or light colored quartzite, and streaks of conglomerate." A red conglomeratic sandstone constitutes the much thicker portion below (1375 feet). It is a " coarse, heavy bedded sandstone of dull brownish hue containing disseminated pebbles and conglomeratic streaks, differing from the overlying beds chiefly in color. In both series the pebbles and conglomeratic streaks are scattered and irregular, while the sands are often cross-bedded. Thin layers of red shale occur, and locally gray sandstones." The deposits probably represent Hood plains, deltas, and alluvial fans accumulated mostly above sea level. (7) Onconta sandstone (Upper flagstone). "Thin and thick bedded sandstones from 20 to 200 feet thick with interbedded red shales up to 30 feet thick." Chiefly light gray to brown in color. Abundant cross-bedding, occasional dark shale, frequent flagstone beds. Capable of furnishing " bluestone " flags and more massive dimension stone. To be seen in the vicinity of West Shokan and westward. (8) Ithaca and Sherburne (lower flagstone " bluestone "). " Thin bedded sandstone, with intercalated beds of dark shale. The sandstones are in masses from a few inches to 40 feet in thickness, greenish gray to light bluish gray or dark gray in color, and are extensively quarried as flagstones." There are occasional conglomeratic streaks. Occurs in large development in the vicinity of the Ashokan reservoir (500 feet). The heavier cross-bedded and coarser grained beds are capable of furnishing an unusually good quality of large dimension stone for heavy structural uses. The beds of this formation near Olive Bridge will in all probability furnish the greater proportion of stone of all kinds for the construction of the great Ashokan dam [see discussion of bluestone near Ashokan dam, pt 2]. The chief common fossil content is impressions of plant remains. (9) Hamilton and Marccllus shales. " Dark gray to black or brown shales with thin arenaceous beds in the upper part." Forms the upper portion of the escarpment that follows the outer margin of the Catskill foothills bordering the westerly side of the middle Rondout and lower Esopus valleys. Occasionally beds are substantial enough for flagstone production (700 feet or more with the Marcellus.) Athyris spiriferoides, Chonetes coronatus. The Marcellus shale is not readily differentiated in the Esopus valley Characteristically it is a thin bedded shale of no great thickness (180 feet in the Schoharie valley) lying between the Onondaga limestone and the Hamilton and obscured by talus from the escarpment (with the Hamilton 700 feet.) The dividing lines between the different sandstones and shale formations, the Oneonta, Ithaca, Sherburne, Hamilton and Marcellus, can not be sharply drawn in the Ksopus region. Together they form in a large way a rather satisfactory held unit. For specific purposes it is necessary to recognize that the lower portions are prevailingly shales with thin bedded sandstones while the upper portions are much more heavily bedded, the sandstones pre- fossil of the Hamilton shales of the Cat.skiil margin vailing. The five divisions may possibly be more satisfactorily made on paleontologic characters than on physical, but in most of the advisory reports on economic and practical problems involving this district the subdivisions can not be emphasized. The wdiole scries is essentially conformable and is very little disturbed [see report on Milestone quarries, pt 2]. (10) Onondaga limestone. A bluish gray, massive, thick bedded cherty, somewhat crystalline limestone. It is strongly marked off from the Hamilton and Marcellus above, and, because of its greater resistance to erosion, usually forms a dip slope controlling stream adjustment and ultimately inducing the development of unsymmetrical valleys w ith gentle easterly slopes and clifflike westerly borders where the streams are sapping the overlying Marcellus and Hamilton shales. It is not sharply separable from the Esopus below but everywhere in this region graduates into it with increase of silicious and argillaceous impurities. Estimating the formation from the drill cores that have penetrated it, and placing the lower limit as nearly as may be at the horizon of changes from predominant lime to predominant silicious content, the approximate thickness in this region is placed at 200 feet. The rock where exposed exhibits considerable joint development and these are considerably enlarged by the solvent action of percolating waters. This factor is considered of some importance in connection with the other limestones of the district in aqueduct construction and permanence. The Onondaga has been used as a building stone formerly sold as marble, some grades of which are good stone. On the line of the aqueduct it is confined to the Rondout and Esopus valleys. The chief fossils are: Atrypa reticularis, Zaphrentis prolifica, Leptostrophia perplana, Platyceras dumosum, Leptaena rhomboidalis, Dalmanites selenurus. (11) Esopus and Schoharie shales (a slaty grit). The Schoharie as a distinct formation is not distinguishable in this region. The very thick and comparatively uniform, gritty, black, dense, almost structureless rock is a distinct unit. It is a silicious mud rock with very obscure sedimentation markings, but showing independent secondary cleavages induced by later dynamic factors, and, on long exposed surfaces always exhibiting chiplike fragments as the result of weathering. But it is not an easily destroyed rock. In so far as the bedding is obscure and the induced structure predominates, the rock is a slate; and in so far as it is distinctly gritty (sandy) instead of argillaceous it is a grit. The formation might therefore be more accurately designated as a slaty grit. The lack of plain bedding structure makes it impossible to estimate its thickness, since the foldings or other displacements can not be allowed for ; but the accumulated data of drill holes in more advantageous position indicate an approximate thickness of 800 feet. The rock is considered exceptionally good ground for the tunnel. A few fossils occur the most characteristic being Taonurus c a u d a g a 1 1 i . There are also in certain layers of limited extent, Leptocoelia acutiplicata and Atrypa spinosa. (12) Oriskany and Port Eivcn transition (silicious shaly limestone). There is no well defined and distinct separation here between the Oriskany and the underlying Port Ewen, but because of the importance and persistence of the formation in other and related areas the name is held. The equivalent of the Oriskany is in this district involved with a strongly developed transition zone which in physical features is intimately associated with the Port Ewen as a single unit. If any distinct formation is to be recognized it would be on the basis of transitional faunal character, placing the fossiliferous upper 100 feet in the Oriskany transition and confining the name Port Ewen to the rather unfossiliferous and concretionary, shaly, argillaceous limestone of the lower 100 feet. This transition rock is strongly bedded, argillaceous and silicious limestone, very quartzose in certain layers, but there are no exposures in this area that would be called sandstones. Fossils are abundant and show marked Oriskany peculiarities. Those of most characteristic relations are : Hipparionyx proximus, Leptostrophia magnifica, Spirifer murchisoni, Spirifer arenosus, Platyceras nodosum, Strop hostylus expansus. (13) Port Ewen shaly limestone. The beds below those noted in the preceding paragraph are essentially argillaceous, shaly limestones. They vary from rather massive to thin bedded, are dark grayish in color, and have a peculiar nodular or concretionary development along certain sedimentation lines. These spots have less resistance to weather than the surrounding rock and therefore develop rows of pits along the face of an outcrop. Their size, 6 to 18 inches or more across, together with their persistence makes an easily recognized physical feature. The few fossils that are found are not very characteristic. The following should be mentioned : Spirif er perlamellosus. (14) Becraft limestone. Massive, heavy to thin bedded, light colored, semicrvstalline to thoroughly crystalline limestone. More massive beds very pure, 94 -1- i Cat ( ) ... Shaly beds resemble the New Scotland which they pass into at the base. The most characteristic features for field identification are (a) pink or light colored spots, (£>) a more u 1 u s campbellanus. (15) A ezv Scotland slialy limestone. Thin bedded, dark gray to reddish sandy and shaly limestones. The rock breaks out in slabs on weathering and develops red iron stains. It has especially abundant fossils, the most characteristic of which are: Orthot h e t e s w o o 1 w o r t h a n u s , Spirifer macropleura. Other common ones are : L e p t a e n a r h o m b o i d a 1 i s , Strop honella headleyana, Ripidomella oblata, Strop heodonta becki. (16) Coeymans Hun-stone. Heavy bedded, dark gray, argillaceous and flinty limestone. The characteristic features for field identification arc (a) abundant chert nodules, (b)- the occurrence of coral reef structure and heads of corals, Favosites h elder- b e r g i a . This formation has a thickness of about 8o feet and is rather distinctly separated from the underlying Manlius. The Coeymans is considered the base of the Devonic system of New York. It is deposition. c Siluric strata. (17) Manlius limestone. Lime mud rock, fine textured, dense, with plainly marked sedimentation lines, gray to dark gray color. The most characteristic features in the field are (a) fine texture, (£>) sedimentation lines, as if laid down in quiet waters as a lime mud, (c) solution joints sometimes enlarged to cavelike form into which surface streams disappear (such as Pompey's cave near High Falls), (d) mud crack surfaces (in lower beds), (e) occurrence of the fossil Leperditia alta. ities from them is considered an objectionable character. (18) Cobleskill and cement beds (limestone). It is not possible without the most painstaking, comparative, chemical and paleontologic research to differentiate the cement layers from the inclosing beds and to assign them all to the subdivisions that are recognized in some previous publications,1 as the (a) Rondout cement (b) Cobleskill limestone, (c) Rosendale cement, and (d) Wilbur limestone. There are, however, two workable natudal cement beds, both at Rondout and at Rosendale, with a nonworkable layer between each case, and also one between the lower and the next underlying formation. Whether the two cement beds at Rondout represent the Rondout and the Rosendale horizons with the Cobleskill between, or whether they should both be regarded as Rondout with Cobleskill below, can not concern our present problems. And again, whether or not the two cement beds at Rondout are the same two that appear at Rosendale, or whether they are equivalent only to the upper one with a new lower bed (The Rosendale) added in this area and then with the Cobleskill between these two as claimed by Grabau, does not alter the plain fact that the whole series is a physical unit. It is a gray, rather close texture limestone, resembling the Manlius proper, and contains few fossils. It is perhaps even better yet to group all of these limestone beds below the Coeymans into a single unit and call it the Manlius series. (19) Binnezvater sandstone. Below the Manlius cement rock series lies the 60-100 foot Binnewater. It is chiefly a well bedded quartz sandstone, almost a quartzite in the upper beds with more shale in its lower portion, in color varying from white to greenish yellow and brown. The rock is rather porous in certain beds and especially along the bedding planes and is not well recemented where crushed by crustal movements. It is confined to the Rondout valley. from drill cores is seldom highly colored. The protected beds are more commonly greenish in color and contain much iron sulphide. Occasional thin limestone beds occur in the upper portion at High falls — one of 4 feet forms the lip of the lower fall. The High Falls shale is confined to the Rondout valley and on the line of the aqueduct is 67-100 feet thick. (21) Shawangunk conglomerate. The Shawangunk is a conglomerate and sandstone. The constituent pebbles are almost wholly quartz, well worn, and varying in size from that of sand to pebbles of several inches diameter. But for the most part the pebbles are small, abundantly mixed with sand, bound together by a silicious cement. Rarely a true quartzite is developed and still more rarely a shaly facies. The rock is therefore very hard, brittle, and in the undisturbed portions fairly impervious and resistant. But it suffers from crushing along zones of disturbance in folding and faulting and these zones are very imperfectly recemented. It is a durable rock, very resistant to ordinary decay, but forms great talus slopes. It is used for buhrstones (millstones), etc. It varies in thickness on the lines of the aqueduct from 280-400 feet. The rock is limited in its northward extension to this district — southwestward it is much more broadly exposed in the continuation of the Shawangunk range. The Shawangunk completes the conformable Siluro-Devonic series down to the erosion interval at the close of the Ordovicic. The series of conglomerates, sandstones, limestones, and shales make an imposing column approximating 3000 feet of strata differentiated with more or less ease into 15 separate and mapable formations and a possible 5 or 6 more with careful paleontologic work. The series begins with the capping beds of the Shawangunk range and its northward extension toward the Hudson river at Rondout and Kingston, and thence westward constitutes the rock floor while its structures control the surface configurations far beyond the limits of the region under consideration. Immediately to the north and partly within the area here treated is the famous Rosendale cement region, the pioneer cement district of America and for many years the best producer. The strata used are almost exclusively the upper members of the Siluric {" cement beds ") closely associated with the Cobleskill between the Manlius proper and the Binnewater sandstone. Rarely the Becraft from the Devonic series furnishes some cement rock. sediments of the Shawangunk range and the Catskills above, lies a series of quartzites, limestones and slates less complexly disturbed than the older and more disturbed than the younger series — set off from both by unconformities representing time intervals that cover both folding and erosion. They are of more than 4000 feet thickness — how much more it is impossible to estimate because of the obscurity of data in the slates. There are very few fossil forms preserved in them. The series is, however, readily and sharply separable into three formations that may be mapped upon lithologic characters alone. They are of most importance in the Wallkill valley, Moodna creek, Newburgh, Fishkill, New Hamburg and Poughkeepsie districts. Their character, structure, and conditions have required careful consideration in the decisions on the Wallkill and Moodna siphons and in the discussions on the proposed Hudson river crossings [sec Hudson river crossings, pt 2]. (22) Hudson River slates. The upper member of the CambroOrdovicic series is in itself complex. Prevailingly it is a slaty shale, occasionally it is a sandstone or shaly sandstone, or a simple shale ; still more rarely it is almost a true slate, and very rarely a phyllite. The constituents vary from prevailing clay to quartz sand repeatedly in almost every locality. It is probable that as a rule the upper portions are the more heavily bedded and arenaceous. The rock is excessively affected by the dynamic movements that have at least twice disturbed it. A slaty cleavage in the more argillaceous members is most noticeable, but almost everywhere the strata are strongly tilted, crumpled, broken, faulted, or crushed in a most confusing way. This together with an original obscurity in bedding, and the obliteration by subsequent shearing of much that did exist, makes it impossible to reconstruct the complicated structure or compute the thickness of the formation. It is of such physical character as to absorb within its own limits much of the disturbing movements, and neither the formations above nor immediately below are so extensively and intimately affected. The formation is widely exposed and forms the bed rock over very large areas. Almost everywhere it is impervious to water, easy to penetrate by drill or tunnel, and resistant to decay. A few Ordovicic fossils may be found, the most characteristic being D a 1 m a n e 1 1 a testudinaria. Ordovicic). The formation is prevailingly of a compact, fine texture, dark gray, either massive or strongly bedded limestone. Where the stratification is very plain there are light and dark layers and an abundant silicious intermixture. In many outcrops the rock is so massive that even the dip and strike are obscure. Some places the rock is fine crystalline, almost a micromarble. On weathered surfaces it almost always exhibits a crisscross etching which marks the traces of rehealed cracks. From these it is seen that many of the apparently massive compact beds have at one time been extensively crushed. In many places there is scarcely a square inch wholly free from these evidences. The formation is best exposed in the wide belt that extends southwestward from the vicinity of Poughkeepsie and crosses the Hudson at New Hamburg into the Newburgh district. It undoubtedly underlies the slates in the rest of the adjacent area. There are few fossils and they are rarely found. (24) Poughquag quartsite. ■ Below the Wappinger limestone and upon the upturned and eroded edges of the Highlands gneisses lies a quartzite of variable thickness but which reaches at least 600 feet. It is a strongly silicified quartz sandstone — a quartzite by induration. It is strongly bedded but seldom shaly. Traces of schistosity may appear in certain zones and this is somewhat strongly developed outside of the area at the type locality (Poughquag, N. Y.). tion within the district. g Later crystallines south of the Highlands. South of the Highlands proper except at one locality (Peekskill creek valley and its southwestward continuation through Tompkins Cove and Stony Point) the rocks are all much more thoroughly crystalline. There are two formations, and in places traces of a third, above the Grenville gneisses (Fordham gneisses and associates). These are known locally as Manhattan schist, Inwood limestone, and Lozvcrrc quartzite. In Westchester and New York counties the quartzite is rarely found, and in a considerable proportion of those places where it does occur its relations are more consistent with the gneisses below than with the limestone-schist series above. This is true indeed of the type locality (Lowerre). There are, however, at least two points where the occurrence favors the reverse interpretation, so far as any is shown, and therefore a quartzite may be regarded as finishing the series, and making uncertain but probably unconformable contact with the underlying gneisses. This series together with the gneisses below constitutes the bed rock and controls the underground conditions for all of the line south of the Moodna valley, 50 miles above New York. All of the southern aqueduct, and the New York city distribution conduits are wholly concerned with these rocks, and two divisions of the northern aqueduct have a large proportion of their work in them. It is not wholly clear what age these crystallines represent. It is certain that the underlying gneisses are Grenville and that the metamorphic quartzite, Inwood, Manhattan series, is Post-grenville. It is possible that these latter are also Precambric. But usage following the correlations of Dana1 and in the absence of as good evidence from any other source has regarded them as the Cambro-Ordovicic crystalline equivalents of the Poughquag-YYappinger-Hudson River series of the north side of the Highlands. The writer has elsewhere shown2 that the evidence and arguments are not all on one side and that considerable doubt may still be entertained on that point. There is no object in following that argument here or in modifying the treatment here followed of making them a distinct series. Even if they should prove to be the exact equivalents of the Hudson River- Wappinger-Poughquag series the formations are physically so different and require so different treatment in discussion that they must for our present purpose be regarded as an essentially distinct series. From that standpoint alone the usage here followed is justified. The Manhattan schist of Westchester county as a type differs as much petrographically from the Hudson River formation of the Newburgh district as the Catskill formation of Slide mountain differs from the Jameco gravels of Long Island. In a discussion where physical or petrographic character is in control there is no doubt about the advisability of treating the two separately. (1) Manhattan schist This is primarily a recrystallized sediment of silicious type. It occurs as a nearly black or streaked, micaceous, coarsely crystalline, strongly foliated rock. The chief constituents are biotite, muscovite and quartz. Quartz, feldspar, 1 Dana, J. D. On the Geological Relations of the Limestone belts of Westchester county, N. Y. Am. Jour. Sci. 20:21-32, 194-220, 359-75, 450-56 (1880); 21:425-43; 22:103-19, 313-15. 327-35 (1881). garnet, fibrolite and epidote also occur in large quantity. Occasional streaks or masses are hornblendic instead of micaceous. These are interpreted as igneous injections. They are especially abundant on Croton lake and near White Plains. It is essentially a quartz-mica schist. But it is almost everywhere very coarse textured and hardly ever exhibits the fine grained, uniform structure of typical schist. Its abnormal make-up — the predominance of biotite and quartz — is the best defense for its petrographic classification. The abundance of mica makes it a tough rock but not very hard. The joints and fractures formed in later movements are not healed and zones of bad shattering are susceptible to considerable decay. These crushings are sufficiently common to encourage borings to tap their content of water for small family use throughout Westchester county ; but they do not represent large circulation in any case. On the whole, the rock if fresh is good and durable. It may, though rarely, carry considerable sulphide. Practically all of the strictly original sedimentation marks are destroyed by metamorphism. The formation has great thickness, but because of the destruction of original bedding lines by recrystallization and additional complication by most complex folding, shearing, crushing and faulting, the structure can not fully be unraveled and the thickness can not be estimated with any approach to accuracy of detail. But there is probably a thickness represented of several thousand feet. (2) Inwood limestone or dolomite. This formation lies beneath the Manhattan. It is everywhere coarsely crystalline either massive or strongly bedded, often very impure with development of secondary (recrystallized) mica (phlogopite) and other silicates, especially tremolite. It is essentially a magnesian limestone or dolomite in composition. There is an occasional quartzose bed in the midst of the limestone as at East View. The upper beds are most charged with mica and occasionally beds attacked by alteration have much green, flaky chlorite. There are occasional interbeddings of limestone and schist as a transition fades. The coarser grades upon exposure to weathering readily yield by disintegration to a lime (calcite) sand resembling rouehlv an ordinary sand in general appearance. At Inwood, the type locality, this disintegration is so pronounced that great quantities are readily shoveled up and used for various structural purposes in the place of other sand. This dolomite is especially liable, as now shown by extensive explorations, to serious decay to great depth. The underground circulation seems to attack the micaceous beds with great success and in some places the residue after this solvent action is of the consistency of mud. A nearly vertical attitude of the beds accentuates the opportunity. The most troublesome piece of ground encountered on the whole line of the New Croton aqueduct, constructed in 1885, was in a weak zone and crevice in the Inwood near the village of Woodland on the margin of the Sawmill valley [see discussions of Bryn Mawr siphon and New York city distributions in part 2]. The thickness probably varies but in many places where there is only a narrow limestone belt it is due more to shearing or faulting out than to original thinning. The most satisfactory estimates are based on the explorations at Kensico dam and the field observations at I52d street. They indicate- an approximate thickness of 700 feet. But in all cases either the margins are obscured or there is possibility of faulting to modify measurements. There are no fossils. Weathering and erosion has almost everywhere developed valleys or depressions especially small tributary valleys in all formations, but as pointed out years ago by Professor Dana the principal valleys prevailingly coincide with the limestone belts. (3) Lowcrre quartzite. At Hastings-on-Hudson and again near Croton lake, there is a quartzite that appears to be conformable with the Inwood above. There is possibly more than 50 feet. It is a simple, clean quartzite. The other quartzites of Westchester and New York county have a more distinct relationship to the underlying gneisses with which they are conformable. The Lowerre of the type locality is of this second class. In the great majority of places where this bed would be expected to occur there is not a trace of it. h Older metamorphic crystallines (Grenville series).1 "The lowest and oldest, as well as the most complex in structure and rock variety, of all the formations of the Highlands region of southeastern New York is essentially a series of gneisses." Cutting these gneisses as intrusions of various forms are a great number and variety of more or less distinctly igneous types. In form they vary from small dikes or stringers to' great batholithic masses; in composition, from the extremely basic peridotites or pyroxinites of 1 This interpretation of the larger relations of the complex gneisses constituting the basis of the series, lying below the Manhattan-InwoodLowerre series, was presented by the writer under the title: Structural and Stratigraphic Features of the Basal Gneisses of the Highlands. N. Y. State Mus. Bui. 107 (1907). p. 361-78. The accompanying description is largely an abstract of this paper. the Cortlandt series to the very acid granites of Storm King mountain or the granophyric pegmatites of North White Plains; and in relative age they likewise vary from a period antedating the chief early metamorphic transformation of the Grenville to Postmanhattan time. Put these clearly igneous types attain a considerable prominence as separable units in the practical consideration of the problems of the project and on that account the chief ones will be more fully described under the next group. The older portion — the various schists, banded gneisses, quartzites, quartzose gneisses, graphitic schists, and serpentinous and tremolitic limestone, forming the complex through which and into which the igneous masses have been injected — form together an interbedded series that was originally a sedimentary group. There is nothing known that is older in this region. Us characteristics and relations mark it as in all probability the equivalent of the " Grenville " of the Adirondacks and Canada. No single type and no single characteristic can be given as a simple guide to the identification of this formation. The prevalence of certain varieties or groups of these and the strongly banded structure give a certain degree of character that forms a reasonable working base. The formation includes banded granitic, hornblendic, micaceous and quartzose gneisses ; mica, hornblende, chlorite, quartz and epidote schists; garnetiferous, pyritiferous, graphitic, pyroxenic, tremolitic, and magnetitic schists and gneisses ; crystalline, tremolitic, and serpentinous limestones, aphi-dolomites, serpentines and quartzites ; pyrite, pyrohitite and magnetite deposits. This is the basal series. Put it is complicated by a multitude of bands of granitic and dioritic gneisses that represent injections of igneous material at a time sufficiently remote to be subjected to most of the early metamorphic modifications. The equally abundant occurrences of quartz stringers and pegmatite lenses though of later origin can not be separated from this complex mass and the whole must be regarded as a physical unit. The occurrence of interbedded limestones and quartzites together with a variety of conformable schists and banded rocks, marks the formation as essentially an old recrystallized sediment. No member of this older unit of the basal complex is sufficiently prominent to indicate a great break cr change up to the time of the first great dynamic movements and igneous outbreaks. The following comparatively constant members are sometimes persistent enough to be considered formational units, but even more commonly map separately. (4) Interbeddcd quartzite. Always a quartzite schist and always exhibiting conformity with the banded gneisses and schists. This is regarded as the uppermost member. position and structure. (6) Interbeddcd limestones. Crystalline. Interbedded, very impure, serpentinous and tremolitic. granular dolomites, usually 2 to 50 feet thick, possibly reaching a thickness of more than 100 feet in a few cases. diorites, strongly foliated sills. Many are of very obscure relations. The line of close distinction between recrystallized sediment, segregations accompanying that change, and true igneous injection can not be drawn. i Special additional igneous types. Under this heading are included the massive or little modified, not at all or only moderately foliated, igneous masses of later origin and local rather than regional development. In some cases, however, they are of decidedly controlling importance in the local geology and rise to the status of definite formations. The most noteworthy of these within reach of the aqueduct explorations are : (8) The Storm King gneissoid granite is one of the largest of the clearly igneous and less completely foliated types. It constitutes the whole of Storm King mountain and the larger part of Crows Nest on the west side of the Hudson, and, crossing the river, forms the chief rock of Bull hill and Breakneck ridge. It is a rather acid, coarse grained, reddish granite with considerable gneissoid structure in a large way [see Hudson river crossings, pt2]. different point (Cat hill), widely separated by other types from the Storm King locality, and in rather large development, is worthy of separate note. It is cut, of course, in the long tunnel through Cat hill. (10) The Cortlandt series of gabbro-diorites occupies an area of about 20 square miles between Peekskill and the Croton river, nearly all on the east side of the Hudson. It includes a very complete range of coarse grained, massive, igneous rocks from soda granites, grano-diorites and quartz-diorites to true diorites, norites, gabbros, pyroxenites, and peridotitcs. They doubtless represent stages or portions in the differentiation of a magma. The interrelations are only partially determinable, and the petrographic distinctions in detail are not useful here. The area occupied by the Cortlandt series has an uneven hilly surface with no structural trend, and makes the most striking contrast to the ridge and longitudinal valley structure of the rest of the region of the crystallines. (11) The Peekskill granite, a white, or pink massive, very coarse grained, soda granite, occupying approximately 4 square miles immediately north of the Cortlandt area 2 miles east of Peekskill, is believed to be genetically related to the Cortlandt series. The evidence in favor of such a relationship has been gathered in the prosecution of this work and has not been published. But it may be said that the textures, structure, age, relationship to older crystallines, interrelations with the Cortlandt series, consanguinity of mineralogy, and composition all point toward the above relationship. In essential relations, therefore, it is the acid extreme of the Cortlandt series. Its economic features, however, are of sufficient importance and its easy differentiation from the regular Cortlandt types require that it should have separate treatment. (12) The Rravenszvood grano-diorite occurs chiefly in Brooklyn. It is a slightly foliated mass intrusive in the Fordham gneiss and is doubtless connected in origin with the sources of many of the hornblendic intrusive bands in the Fordham and Manhattan formations in the district. It covers a known area of about 5 or 6 square miles and may be more extensive. The rock is suitable for structural material and has required consideration in the study of " Distributary conduits " [see pt 2 East River section]. (13) Pegmatites. The pegmatites and pegmatitic granophyric masses of all kinds are of almost universal distribution in the foliated crystallines. They vary from quartz bunches or stringers to pegmatitic lenses and irregular masses, and to definite granitic or pegmatic dikes. In many places they constitute a large proportion of the formation in which they occur. They doubtless vary in age, but for the most part seem to belong to the later period of metamorphism. Many of them are massive and largely free from foliation. They no doubt have a complex origin between simple aqueous segregation on the one side and true igneous intrusion on the other. Till and modified drift, extra mantle over nearly all marginal outwash, sands and > of the region under gravels, etc. discussion, except the 3 Major structural features In addition to the simpler structural characters of the strata, already sufficiently emphasized in the individual descriptions, there are numerous others of more general relation whose value and influence it is necessary to consider in many of the practical problems. Those of most importance are the unconformities, folds and faults. They are directly related to continental elevation and subsidence, to mountain forming movements and denudation processes, to metamorphism and to igneous intrusion. a Sedimentation structures. In the younger strata the principal structures are those of bedding, stratification, conformable -succession, etc., characteristic of all sediments of such variety of type. These are prominent in the older groups of formations down to the crystallines, but the earlier Paleozoics are also affected sc profoundly by folding and faulting that attention is more concerned with these induced or secondary structures. ance of strata and accompanied by erosion, are numerous. (1) That between the glacial drift and the rock floor is the most profound. It causes the glacial drift to lie in contact with every formation of the region from the oldest gneisses of the Grenville series of the Highlands to the traces of Miocene beds of Long Island. (2) The interval between the Pliocene and the Upper Cretaceous beds is more obscure and hardly reaches the importance of an unconformity. It is probably more nearly of the value of a disconformity or of an overlap, and the very limited development of the overlying beds in the region gives little chance for determining relations in much detail. of the Hudson river. (4) The unconformity between the Triassic and underlying formations of different ages. An interval representing mountain development and extensive erosion* in which the chief movement probably belongs to the close of Paleozoic time and includes the Appalachian folding. (5) Unconformity between Siluric and the Ordovicic strata. An interval representing mountain development, folding and erosion, in which the movement known as the Green Mountain folding took place. (6) Unconformity between the Poughquag (Cambric) quartzite and the underlying crystallines. An interval in all observable cases of great length and profound changes involving mountain folding, metamorphism of the profoundest sort, and extensive erosion. (7) Among the crystallines of the south side of the Highlands there is one break of similar importance, between the Inwood limestone and the underlying gneisses. Whether or not it is the same as no. 7 above is not clear, but even if it represents the same break the relations are somewhat different in degree and character because of the lack of quartzite in almost all cases. Within the gneisses of the Grenville series and their associates of all kinds there are no breaks of the unconformity type known. The contacts are eruptive in character, or are displacements instead. c Folds and mountain-forming movements. All of the formations from the oldest up to and including the Lower Devonic strata are folded. Many of the smaller (minor) folds exhibit complete form in the stream gorges of the district, but all of the larger ones, the main folds, have in earlier time been eroded to such extent that the series is beveled off and only the truncated edges are to be seen, exhibiting strata standing more or less perfectly on edge, and making restoration of the form a very difficult or impossible task. This is only partially accomplished in the Siluro-Devonic margin along the Shawangunk range ; it is more complete in the Cambro-Ordovicic north of the Highlands, and it reaches its most perfect development in the crystallines of the Highlands and New York and Westchester counties. These differences correspond roughly to the differences in age of the strata, and, taken together with the evidence of the profound unconformities, indicate that mountain-forming movements of far-reaching importance visited the region no less than three times. Each time of such disturbance, of course, the underlying older series was affected by the movements of that epoch in addition to any previous ones, and as a consequence the older is to be expected to show more complexity of such structures. Each succeeding series separated by such activity is therefore one degree simpler in structure. Of these three epochs of great disturbance, one is (1) Precambric and corresponds to the time interval marked by the unconformity between the Poughquag quartzite and the gneisses; a second (2) is Postordovicic and corresponds to the time interval marked by the unconformity between the Hudson River slates and the Shawan- gunk conglomerates, and the last (3) is Postdevonic (probably Postcarbonic, judging from neighboring regions of similar history) and has left as its most important evidence in this district, the excessively complicated sharp foldings and thrusts of the Shawangunk range and its extension in the Rosendale cement district. Kinds. As to forms produced there are no usually described types that are not to be found here. The simpler forms of anticlines and synclines, both open and closed, symmetrical and unsymmctrical and overturned, are all common. The isoclinal is common in the gneisses. In each epoch of folding the compression forces were effective chiefly in a northwest-southeast direction producing arches and troughs whose axes trend northeast-southwest. This i.s the trend of the main structures throughout the region. The extent of crustal shortening accomplished by this series of compressions is undetermined, but that it amounts to a total of many miles is indicated by the fact that over broad areas the strata stand almost on edge. Furthermore, in the older Highlands and in portions of the Hudson river districts the folds have been slightly overturned so that commonly the strata on both limbs dip in the same direction (toward the southeast). This seems to indicate a strong thrust from the southeast. All stages between the gentlest warping to strongly overturned folds, and from minute crumbling to folds of great extent and persistence are to be seen. The effect of all the folding is chiefly to present a series of upturned strata to erosion and encourage a subsequent development of valleys along the softer beds bordered by ridges of the more resistant types. As the axes of the folds lie in a northeast-southwest direction, this gives a marked physiographic development of ridges and valleys of the same trend, a most conspicuous topographic feature of southeastern New York. d Faults. Accompanying the folding in each epoch, and especially the stronger overthrust movements there has been a tendency to rupture and displacement. These breaks are known as faults. Multitudes of them are of minute proportions and practically neglectable in a broad view, but many also are of large extent, traceable across country for many miles and indicating displacements in some cases of many hundreds of feet. For the most part these faults are of the thrust type and wholly consistent with the folds in origin. They run generally in a northeast-southwest direction, especially the larger ones, and frequently form the separation planes between different formations. Occasional cross faults occur (with northwest-southeast direction across the strike), but so far as is known they are always of minor consequence. In rare instances, the trace of a fault line on the surface describes curious curves, such as that at Cronomer hill above Newburgh, apparently inconsistent with the chief structural trend, but a study of the whole geologic relation in such cases shows them to be connected with the projecting spurs of underlying formations which in any large thrust movement plow their way with some success through the younger overlying, less resistant, strata. They differ in no material way from the ether more simple looking lines. to be most common. The amount of displacement or throw is extremely variable. The larger faults represent movements of several hundred feet. In rare cases the movement may be as much as 2000 feet. The effects may be grouped as follows: (1) the appearance of formations out of their normal order, i. e. contacts between formations that do not normally lie next to each other; (2) the production of escarpments, i. e. steep cliff-bordered ridges; (3) the development of zones of more or less extensively crushed rock along the principal plane of movement; (4) the determination of location for stream courses and gulches and valleys that cross the formations. All of these effects are more noticeable and better preserved for the later movements than for the earlier ones. Many of those dating back to the earliest epoch, affecting only the crystalline rocks of the Highlands, are not readily detected. Most of the breaks have been healed by recrystallization and the contacts are often as close and sound as any other part of the formation. But this is not so true of the later epochs — and in them a good deal depends upon the type of rock affected. The more brittle and hard and insoluble types are more likely to still have open seams and unhealed fractures than the softer and more easily molded formations. In some of these, recent water circulation has still further injured the fault zones by introducing rock decay to considerable depth. Because of the more ready circulation in them, it is noticeable that some of the extensive decay effects are produced in crystalline rocks that otherwise very successfully resist destruction. On the whole the softer clay shales and slates are less likely to preserve open water channels of this sort than any other formation of the region. No part of the region is wholly free from faulting effects, except perhaps a part of Long Island. The Catskills also are very little affected — so little that this type of structure has not require consideration in the vicinity of Ashokan reservoir. But all parts of both the northern and southern aqueduct system have had this feature to consider. Further discussion of the specific local prohlems introduced by faulting and folding is given under the problems of part 2. A considerably more extended comment on the age of fault movement is given under the heading " Postglacial faulting." 4 Outline of geologic history Most of the genera! features of geologic history have been involved more or less in the foregoing discussion. It is impossible to wholly separate matters that are so intimately interrelated even though it is convenient to think of or consider one phase at a time. But it may serve a useful purpose to summarize the steps of progress as illustrated by local geology from the earliest geologic time to the present. a Earliest time. (Prepaleozoic, Agnotozoic, Proterozoic, or Azoic Era). There is little doubt that the oldest rocks known in this region are representatives of a time of regular sedimentation. Conditions favored the deposition of silicious detritus of variable composition with an occasional deposition of lime, nearly always in very thin beds. What these sediments were laid down upon or where they came from are unsolved questions. The remnants of them that are still preserved are the basis of the " Grenville series " as interpreted in this area, and are the basal (oldest) members of the " Fordham " or " Highlands gneisses." How long ago this series was deposited is not known. It can be stated only approximately even in the rather flexible terms used in historical geology. It is older than any Paleozoic strata (Precambric), probably very much older. It is even possible that this series is as much older than the Cambric as that period is compared to the present. In short, it is not known, and there is apparently little immediate likelihood of finding out even to which of the several subdivisions of the Prepaleozoic this series belongs. It is certain that before the Cambric sandstones of the Paleozoic era had begun to form, this older series was disturbed by crustal movements, folded, metamorphosed, intruded by igneous injections, elevated above the water (sea) level of that time and eroded by surface agencies. These movements and steps there is no doubt of. ite began. /; Early Paleozoic time. With the sedimentation upon this old crystalline rock floor a long time of apparently continuous deposition began which ultimately resulted in the accumulation of several thousand feet of sandstones, limestones, and sandy or clayey shales that are now known as the Cambro-Ordovicic series (PoughquagWappinger-Hudson River series). But at the close of Ordovicic time or late in that period another crustal revolution began. The whole region was again compressed into mountain folds, faulted, sheared, metamorphosed, elevated above sea level, and subjected to erosion. This corresponds to the Green mountains folding of Vermont. With the next subsidence and a return of sedimentation a new series began to form. The break marking the occurrence of all these changes, known locally as the Postordovicic unconformity, represents a considerable portion of Siluric time. c Middle Paleozoic time. The earliest deposits of this series, which continued to accumulate through late Siluric and all of Devonic time, were heavy conglomerates very unevenly distributed over the new rock floor. These are the so called Shawangunk conglomerates, a formation that within the boundaries of this immediate area and within a distance of 20 miles varies from a thickness of more than 300 feet to almost nothing. But for the most part, sedimentation was regular and fairly continuous and of immense volume. The whole series of conglomerates, sandstones, shales, grits and limestones belonging to the later Siluric and the Devonic are included. Not all are believed to be marine however. The Catskill and Shawangunk conglomerates may well be of continental type. Long after the deposition of all of these strata another crustal disturbance, for at least the third time, repeated the process of mountain-folding and erosion. This was the time of the Appalachian mountain-folding. In this region it caused a wonderfully complex development of folds and faults that are especially important and determinable as to type and age in the Rondout cement region. The movement, of course, affected all of the older formations as 1 There may possibly be an intermediate stage, practically a duplication of the whole as given above, between the very oldest and the Cambric, represented in the " later crystallines," but this may as well be neglected for the present. well, but on them, already disturbed by earlier displacements, the features chargeable to the disturbance can not always be distinguished from older ones. All three of the mountain-forming compressions seem to have been controlled by the same relationship of forces and adjustments of movement, for the results are in each case the production of folds or faults of similar orientation and a final structure of uniform trend. Deposition had been going on for ages, chiefly on the west and north side of the older crystallines ; but with a return of sedimentation a decided reversal is noted. The Atlantic border is depressed and much of the interior region seems not to have been subjected to further deposition from that time even to the present. d Mesozoic time. Again conglomerates, sandstones and shales were laid down upon an eroded floor. From their condition and lithology it is believed that they are partly of continental, flood plain, origin. The series is thick, generally assigned to the Triassic period and is extensively developed. During the time of accumulation and to some extent subsequent to it, there was extensive igneous activity pouring out and intruding basic basaltic matter in large amount. The Palisade diabase sill, and the Watchung Mountain basalt flows are the best examples. At a later time small faulting occurred making frequent displacements in this series. But mountain-folding has not again visited the region. Such breaks as there are, are of the nature of overlaps and disconformities rather than of the revolutionary history indicated by a true unconformity. One of these intervals occurs in the Mesozoic between the Triassic and Cretaceous. Above it the thick series of Cretaceous shales, marls, sands and clays are developed. Succeeding this series a similar interval represents the earliest Cenozoic time. time of the glacial invasion. / Late Cenozoic time — glacial period. By some combination of conditions not very well understood, the chief features of which no doubt are, — (i) continental elevation and (2) shifting of centers of precipitation and (3) modification in the composition of the atmosphere, a period of excessive ice accumulation was inaugurated. Ice finally covered immense continental areas and from its own weight by continuous accumulation spread out (flowed) from great central areas toward the margins. There is clear evidence of interruptions or advances and retreats of this general movement many times. But the same type of work and similar results were attained in each case. The chief features of this work was the moving of rock material frozen in the ice to long distances and the deposition of it again, more or less modified by its contact with the ice or by the effect of water upon its release, at other places and with entirely new associations. The tendency to ice accumulation was finally overcome to sufficient extent for the inauguration of the present condition of things. Whether it is a permanent change or only an interglacial interval is not clear. But the ice has withdrawn to the mountains and the polar north at the present time. It has not occupied the surface of this region probably within the last 40,000 years, and perhaps for a much longer time. The surface features of a country are the result of the working out of a long and complex series of processes with and upon the materials of the rock floor or bed rock. The relationship of surface features to the formations that occur in the rock floor and their stages of development, in short, an interpretation of their origin and meaning, constitutes geographic history or physiography. It differs little in essential character from geologic history, of which it is only a special branch, i. e. the history of surface configuration. And it can not be appreciated or understood except in the light of a thorough knowledge of stratigraphic and structural geology. In individual cases or particular regions the geologic knowledge must also be specific. a Early stages. Occasional glimpses of surface features, and some scattered facts about their development are to be gathered of older continental existence. Surface features characteristic of their time were developed in the great intervals between each successive period of continuous deposition. Traces of them are involved in the unconformities of the geologic column already shown in the discussion of geologic history. Hills, valleys, streams, shores and all the appropriate assortment of forms must have existed. But they could not have been like those of the present in many minor features — especially in arrangement and distribution — because the bed rock of those times had only in part reached the complexity of structure and composition now belonging to it. Many items of importance are indicated in some of these early periods. For example, the sea encroached on the land borders repeatedly from the westward — especially throughout Palezoic times, while in Mesozoic and Cenozoic times the evidence of shif tings of sea margins is confined to the east and southeast borders, and likewise probably no near by place has been continuously beneath the sea. But the unraveling of these conditions is obscured by subsequent events. Land surfaces that once were, became covered by later sediments. The physiography of those times, Paleophysiography, as well as paleogeography, is therefore a difficult and intricate line of investigation. With these ancient* surfaces the dicussion of present features has little to do. Here and there the present surface cuts across and exposes the edges of an older one giving traces of the old profile ; but in most cases it is so distorted by the foldings and other displacements belonging to a later period that a restoration of the original continental features is a task fit for the most highly trained specialist. The surface as it now exists, and the rock floor modified only by the inequalities of the loose soil mantle, yields more readily to investigations of origin and history. b History of present surface configuration. On some portions of the region there seems to have been no deposition since the close of Paleozoic time. Throughout most of Mesozoic and Cenozoic times, therefore, those regions probably have been continuously land areas (continental) and have been subjected to the agencies of erosion. This applies particularly to the Highlands region and the Catskills and the Shawangunk range and intervening country. What the surface configuration was like in the early stages is wholly unknown. In the beginning, mountain-folding — the Appalachian folding — was in progress and the features were probably those of partially dissected anticlinal folds. With the progress of erosion the Triassic deposits were accumulated along the eastern border, probably on the continental slopes. Subsequently, further elevation extended erosion over the Triassic areas also and the Cretaceous beds were laid down on the margin. The general lines of development have been the same from that time to the present. Each successive important formation less heavily developed and forming a band outside of and upon the older one — the whole now constituting a series of successive belts the oldest of which is far inland and the newest at the sea margin. Therefore, when long periods of denudation are referred to, it is well to appreciate that this is especially applicable to the interior, that the sea margins are comparatively new, and that certain of the inland areas were suffering erosion long before the rock formations that lie beneath and form the rock floor of the sea border districts were in existence. Cretaceous peneplain. It appears from studies of these problems in a broad way, and, drawing upon generalizations from continental features of a much larger field than that of the present study, that the continental region of which this forms a part must, in the earlier periods, have remained in comparatively stable equilibrium for an extraordinarily long time. So long a time elapsed that most of the area was reduced by erosion to a monotonous plain (peneplain) at a very low altitude, probably not much above the sea (base level). Only here and there were there areas resistant enough or remote enough to withstand the denuding forces and stand out upon the general plain as remnants of mountain groups (Monadnocks). Possibly the Catskill mountains of that day had such relation. This reduction of surface feature it is believed was reached in late Cretaceous time. The continent stood much lower than now. Portions that are now mountain tops and the crests of ridges were then constituent parts of the rock door of the peneplain not much above sea level. This rock floor was probably thickly covered with alluvial deposits (Hood plain) not very different in character from the alluvial matter of portions of the lower Mississippi valley of today. Upon such a surface the principal rivers of that time flowed, sluggishly meandering over alluvial sands and taking their courses toward the sea (the Atlantic) in large part free from influence by the underlying rock structure. The ridges and valleys, the hills, mountains and gorges of the present were not in existence, except potentially in the hidden differences of hardness or rock structure. Such conditions prevailed over a very large region — certainly all of the eastern portion of the United States. This so called Cretaceous peneplain is the starting point in development of the geographic features of the present. Continental elevation. Following upon this period of stability and extensive denudation came one of continental elevation. How much above sea level this raise:! the areas under present discussion may not be determined, but that it was a sufficient amount to rejuvenate the streams and permit them to begin the sculpturing of the land in a new cycle of erosion is perfectly clear. As soon as the elevation and warping of the continental border made its influence felt in the increased activity and efficiency of the streams (rejuvenation) they began transporting the alluvium of their flood plains and to sink their courses through this loose material to bed rock. The final result of long continued denudation under these conditions in early Tertiary time was the removal of the loose mantle and the beginning of attack on bed rock (superimposed drainage). The streams formerly flowing on alluvium that had now cut down to rock found themselves superimposed upon a rock structure not at all consistent with their former courses. With the progress of erosion on this rock floor all these differences of structure, such as the differences in hardness of beds, the trend of the folds, the strike of the faults, the igneous masses, etc., were discovered and the streams began to adjust their courses to them. Valleys were carved out where belts of softer rock occur, ridges were left as residuary remnants where belts of harder rock exist, and the surface (relief) took on some of the character of present day lines. That is, the principal mountain ranges of that time were the same as those of today in position and trend ; but they had not so great apparent hight because the intervening valleys had not yet been cut so deep. The principal escarpments of that time were due to the same structural lines as those of today, only they have shifted somewhat along with the general retreat of all prominences by the forces of weathering and erosion. In the course of this work of sculpturing and the shifting of valleys and divides and escarpments and barriers into constantly greater and greater conformity with rock structure, it came about by and by that practically all of the smaller and tributary streams had so completely adjusted themselves to their geologic environment that their valleys almost everywhere followed along the softer beds (subsequent streams), the divides were chiefly of harder beds, the trend of both were almost everywhere parallel to the strike of the rock folds and other structures (adjusted drainage) This undoubtedly involved in many cases a very radical change of stream course, and in some cases an ultimate reversal of drainage to such extent that tributaries were deflected inland against the course of the master streams and in some cases actually flowed many miles in this reversed direction before finding an accordant junction (retrograde streams). At least three of the streams of Rondout and the lower portion of the Esopus. But the larger rivers, the great master streams, of the superimposed drainage system, in some cases were so efficient in the corrasion of their channels that the discovery of discordant structures has not heen of sufficient inlluence to displace them, or reverse them, or even to shift them very far from their original direct course to the sea. They cut directly across mountain ridges because they flowed over the plain out of which these ridges have been carved and because their own erosive and transporting power have exceeded those of any of their tributaries or their neighbors. They are superimposed streams (not antecedent), they have, with their tributaries, settled down in the ancient plain, and, by their own erosive activity, have carved the valleys deeper and deeper, cutting the upland divides narrower and narrower until now only here and there a ridge or a mountain remnant stands with its crest or summit almost reaching up to the level of the ancient peneplain on which the work began, if the transported matter could all be brought back and replaced in these valleys the old plain might be restored, but the work would immediately begin al! over again. Tertiary incomplete pencplanation. Such processes, if allowed to continue on a stable continental region, would ultimately reduce the land for a second time to a monotonous plain (complete cycle of erosion). The beginnings of such a plain would be made in the principal stream valleys upon reaching graded condition. Their lateral planation and the development of flat-bottomed valleys would begin at about the level that the plain would stand in the final completed stage. The difference of elevation between the ridge crests or hilltops and these flat valleys, i. e. between the old peneplain and the new unfinished one would be an approximate measure of the amount of the continental elevation that instituted the new cycle. But judging from such remnants of this later plain as are to be seen, the two, i. e. the old Cretaceous peneplain and the new Tertiary peneplain are not parallel. Toward the southeast, toward the sea, the older plain descends more rapidly than the younger and intersects it. Both pass beneath sea level in that direction. The difference between them therefore varies with locality from Late Tertiary rcclevation. Traces of such an intermediate and incomplete peneplain are to be seen in the compound nature of the large valleys of the present day. Most of them are essentially broad valleys into the bottoms of which narrower valleys and gorges are cut. The tops of the minor hills and ridges of the broad valleys represent the intermediate Tertiary peneplain that was interrupted in its development before completion (interrupted erosion cycle). The inner narrow valleys indicate that for the second time a regional elevation rejuvenated the streams and they began their work of cutting to a new grade. They have made a good beginning at this task, and as a consequence have carved some rebel in the old valley bottoms. These new streams have not yet reached a graded condition. When the glacial ice began to invade this region all of the surface features had had such a history. Leaving out of account minor fluctuations of elevation and depression, of which there may have been several of too transient character to make a lasting impression on the topography, the stages become comparatively few and the general tendencies are easily understood. The measurable differences of elevation between the Cretaceous and Tertiary peneplains give some reasonable conception of the amount of the first continental or regional elevation. Concerning the altitude reached in subsequent regional elevation there is less certainty. None of the streams, not even the master streams such as the Hudson, reached grade, for it exhibits strictly a gorge type not only within the present land borders, but it is now known to show gorge development far beyond the present coast line. Judging from the Hudson, therefore, it seems necessary to conclude that this continental region stood at a much greater elevation in some portions of the later period than had formerly prevailed. Probably the maximum elevation immediately preceded the glacial invasion. Conservative estimates as to the amount of elevation of that time in excess of the present would place it at not less than 2000 feet. Much more than that is believed to be indicated, possibly 5000 feet or more. In the meantime, the master stream, the Hudson and several of the tributaries cut into their valley bottoms to such extent as to make typical gorges so deep that their beds now, since the sub- sidence, lie much below sea level. The Hudson bed is of this character throughout its course from Albany to the Atlantic, and in the Highlands, 60 miles inland, the known rock bed at one point is more than 700 feet below sea level. In late glacial time there was still greater subsidence (50-100 feet) than the present as is indicated by terraces above present water level and the deltas formed at the mouths of tributary streams. Such in general outline is the history of successive conditions governing the topographic development of the rock floor. The succession of periods of stability, elevation, stability again, reelevation and subsidence have had an effect on all sorts of formations, but the extent of the impress and its permanence varies greatly in the different districts. Tt is not possible to study these differences in detail here. They are the minor and special local characters that are in control at particular localities. In discussions of special problems some of these are taken up in more detail. But in each case the general history as outlined above, together with the modifying influence of known local structure and stratigraphic character are the foundations of a working understanding [see Hudson River crossings, Moodna creek, Rondout valley, etc., pt 2]. Pleistocene glaciation. An additional modification and one largely independent of and largely inconsistent with the distribution of the smaller features of the rock floor is introduced by the glacial drift. It covers almost everything, but so unevenly as to largely destroy some of the detail. It is in places more than 350 feet thick (as in the Moodna and Rondout valleys') and in others it amounts to nothing. Tt covers the narrow ravines and gorges heaviest and has altered the courses of many of the smaller streams, the original channels being hopelessly buried. The result has been chiefly one of reducing the ruggedness of outline that prevailed along the newer gorges of late preglacial time. Besides this the usual surface forms characteristic of glacial deposits, occur — -the kame, the drumlin, the esker, the hill and kettle topography of the terminal moraine, the overwash plain, the delta, the lake deposit and the gentle undulations of the ground moraine. These are superimposed on the rock floor features. Both are equally important to understand in the problems that have been encountered. Which set of factors is to be most regarded in a given case depends wholly upon the locality and the kind of enterprise or work it is proposed to undertake. c Physiographic interpretation. Rock floor contour is an expression of the differences in character and structure of the bed rock formations themselves, brought about by ordinary surface weathering and transporting agencies, varied in their action and effects only by certain differences in elevation above the sea. It is apparent therefore that it would be possible by careful observation of surface features to gather data sufficiently definite to furnish a basis for suggestions about hidden and hitherto unknown or undiscovered structural and stratigraphic characters. But the application of it to practical engineering problems is a complicated and difficult matter. And this difficulty is nowise simplified by the occurrence of a drift soil that tends to obscure many of the more delicate features. For example, the later narrow stream gorges marking the stage of extreme regional elevation are completely buried. Only an occasional stream like the Hudson has maintained its course unchanged and has begun excavating the channel again. But even in this case, as will be shown under a separate head, the work of reexcavation is only just begun and the amount yet to be done and the corresponding original depth of the gorge are wholly unknown. Certain surface features, however, are readable and, considered with due regard for all possible causal factors, give very useful suggestions. From them one obtains clews as to (i) the attitude nr relations of the hard and soft beds and the weak zones, (2) the dip and strike of strata, (3) the persistence of a formation, (4) the occurrence of faults. (5) the direction of the chief disturbances, (6) the resistance and durability of local rock types — in short the structural characters of all kinds because difference^ in the distribution of these characters have given the different topographic forms and geographic areas. They have made the feature^ of the Highlands look different from those of the Catskills, and those of Wallkill valley different from the Croton. Because of the long train of conditions with which these surface features arc each involved and the structures that they indicate they become easily the chief factors in preliminary judgment of comparative practicability of rival locations, and are the most reliable guide to direction and character and extent of exploratory investigation for many engineering enterprises. West Point Relief map of the region from the Catskill mountains to the Highlands showing the principal physiographic features. (The original model shows also the areal and structural geology.) (Taken from model made in the physiographic laboratory of Columbia University by Messrs Billingsley, Gnmes and Baragwanath) (1) Coastal plain. A district underlain by Cretaceous and later rocks and confined to a part of Staten Island and Long Island, not exceeding 400 feet relief. This zone is characterized by dendritic drainage, except a narrow belt on its inner margin which is a longitudinal valley of the " inner lowland " type. Long Island sound occupies the position of this old adjusted valley. (2) Piedmont belt. A district lying between the coastal plain and the Highlands. It is underlain chiefly by crystalline rocks and metamorphosed sediments. Not exceeding 800 feet relief. It is characterized by adjusted drainage obscured only by drift. The ridges and valleys trend northeast and southwest close together and with very little variation on the east side of the Hudson, while on the west side the gentle dips of the Triassic give broader and more unsymmetrical forms with dip slopes and escarpments wholly independent of the opposite side. The zone is essentially transitional between the simple forms of the coastal plain and the complex mountainous character of the Highlands. (3) Highlands. The rugged elevated zone formed by the crystalline gneisses. Reaching elevations of 1600 feet. It is characterized by irregular mountain masses and lofty ridges of a general northeast trend but with many prominent irregularities both of form and of drainage. The valleys are deep and narrow. There are many steep escarpments. It is a mountainous zone in which complex structures and rocks have led to the development of complex forms. The zone forms a sort of barrier 20 miles wide across the Hudson river which exhibits its most zigzag and narrow and gorgelike development in this district. (4) Appalachian folds. Characterized by folded Paleozoic rocks north of the Highlands. Reaching elevations of 1500 feet rarely — general relief 400-800 feet. North of the Highlands the relief is much less pronounced. The softer rocks of the early Paleozoic formations permitted the development of a broad valley with almost perfectly adjusted tributaries, most of which on the west side of the Hudson are reversed. The topographic forms give expression to the universal folding and faulting of the formations. It is essentially a transition from the complex mountain zone of the Highlands to the much simpler Catskill area. (5) Catskill Monadnock group. Characterized by undisturbed Paleozoic strata and very strong relief — reaching elevations of 3500 feet. The eastern margin is an escarpment facing the Esopus and Rondout valleys which are adjusted to the gently dipping strata of that side. Over the rest of the district the beds lie so flat that drainage is essentially dendritic modified slightly hy jointing. The great relief of the Catskills is due wholly to erosion of flat but very resistant strata that withstood the destructive erosion of Cretaceous peneplanation and stand as residuary remnants even to the present time. The Catskills are therefore essentially a Monadnock group. In structure they are almost as simple as the higher portions of the cuesta of Long Island, and they hold the same relation to the forms developed by erosion out of the old Paleozoic coastal plain of the interior. Summary Physiographically the most complex zone is midway in the region under discussion — i. e. The Highlands. This belt is bordered on both sides by less complicated zones of less relief, of more regular topographic forms and less obscure history — the Piedmont cone on the south and the Paleozoic folds on the north. The outer margins are both simple, essentially eroded coastal plains with strata dipping away from the central belts and on which forms and drainage lines characteristic of such history are developed. These outer zones are the coastal plain of Long Island on the south and the Catskill Monadnock group on the north. It matters little that they differ in age by almost half of the known geologic column. INTRODUCTION The group of studies assembled in this part are chiefly those that have required considerable exploratory investigation in connection with the proposed Catskill aqueduct and that have furnished new data of a geologic character. In some cases the additional investigations have discovered new and wholly unknown structures or conditions and in all cases the features as now established are much more accurately known than would otherwise have been possible. The benefits of the studies have been twofold and reciprocal. On the one side the practical planning of the enterprise has constantly required an interpretation of geologic conditions as a guide to locations and methods and on the other the extensive investigations carried on have given an opportunity for practical application of geologic principles under conditions seldom offered and the data secured in additional explorations serve to make the detail of some of these complex features now among the most fully known of their kind. Examples of such cases are (a) the series of buried preglacial gorges (as in the Esopus, and Rondout and Wallkill and Moodna valleys) and (b) the completed geologic cross sections (such as the Rondout valley, the Peekskill valley, Bryn Mawr, etc.) and (c) the numerous additions to the knowledge of local rock conditions (such as that at Foundry brook, Rondout creek, Coxing kill, Pagenstechers gorge, Sprout brook, and others). Almost every locality has its own specific problem and its own peculiar differences of treatment and interpretation of features. Nearly all of the studies here presented came to the attention of the writer and others1 in the form of definite problems or questions involving an interpretation of geologic factors and an application to some engineering requirement. Some of these questions, as is pointed out more fully in part i, chapter 2, are (a) the location of 1 Professor James F. Kemp of Columbia University and W . O. Crosby of the Massachusetts Institute of Technology and the writer constituted the regular staff of consulting geologists. buried channels beneath the drift, (b) the character and depth of the drift, (c) the kind of bed rock, (d) the condition of bed rock for construction and permanence of tunnel, (c) the underground water circulation, (/) the occurrence of folds and faults, (g) the position of weak zones, (/;) the depth required for substantial conditions, and many other similar problems. These need not be treated in their original form. Indeed many of them have now ceased to be problems in any real sense, for subsequent provings have made them simple facts, and wholly new questions came to take their places. In some of the larger problems, however, it is believed that a treatment which involves a discussion of the original problem and the method of solving it, together with the data thus secured and the final interpretation of geologic features as now understood or established will be more instructive than a mere enumeration of the collected results. So far as possible each problem is treated as a unit and fully enough to be understood by itself. But a general knowledge of local geology as outlined in part i is assumed. GENERAL POSITION OF AQUEDUCT LINE Surface topography constitutes the chief factor in determining the general course of the aqueduct. It is planned to control the water so that it will flow to New York city. There is therefore a gradual descent of aqueduct grade from 510 feet A. T. at Ashokan dam to 295 feet at Hill View reservoir. Wherever the surface of the country is approximately the same as the aqueduct grade for that district it permits of the so called " cut and cover " type of construction which is much cheaper than any other. Therefore, other things being equal, the position that will permit the greatest proportion of cut and cover work would have a decided advantage. So it is possible from any series of good topographic maps to lay out trial lines that are sure to be worthy of consideration. The topographic sheets of the United States Geological Survey and the maps of the New York Geological Survey are of great usefulness in such preliminary work. But a little field examination shows that there are many other features and conditions that materially modify even comparative cost and are still more important factors in consideration of permanence and safety. Sometimes it is not apparent that a course has any objectionable features till considerable exploratory work has been done. Likewise a serious difficulty at one point may more than counterbalance advantages at some other, so that considerable portions of the line are finally shifted to a better average position. In the course of these preliminary explorations much valuable data have been secured that now relate to points a considerable distance off the present line. The information has, however, been necessary and useful. One of the cases of this kind where geologic conditions have had an almost controlling influence is involved in the choice of place of crossing of the Hudson river. It has involved a shift of the whole line between the reservoir and the Highlands. Difficulties encountered in finding a crossing of the Esopus also contributed to the argument favoring a shift of the line [see map of trial lines west of the Hudson] . One of the points where exploratory work had reached definite results before the more southerly line was finally adopted is near West Hurley. Here wash borings were successfully put down through the fine sands and silts of the lower Esopus valley so as to give a fairly acceptable profile of the rock floor [see fig. 7] . Esopus creek in this portion of its course follows the Hamilton shales escarpment which forms a steep border on the west side, while the east border of the valley and floor are formed, by the underlying Onondaga limestone. Gentle westerly dips prevail for both formations, so that in the perfect adjustment reached before the glacial invasion a cross section would have shown a typical unsymmetrical valley — one side a gentle dip slope and the other a bluff developed by the undercutting of the stream as it shifted against the edges of the shales. Results of exploration show that the valley is filled to a depth of more than 200 feet with silts and sands that are essentially overwash and glacial lake deposits. The flat surface further favors this explanation as had been pointed out before any explorations were made. Later observations in that portion of the Rondout valley which is a continuation of this structural feature indicate similar deposits as far soutn as the new line at Kripplebush, 10 miles away. the escarpment is reached. It was further helieved that the covered portion is wholly drift-filled down to the Onondaga. It was easy therefore to estimate the approximate profile and suggest the point of greatest probable depth. The accompanying figure illustrates the form and structure of this valley. Each valley has had in a smaller way a similar study and adjustment of location of line. HUDSON RIVER CANYON This is a special study of the Hudson river gorge1 based upon explorations by borings at the several proposed crossings. Altogether 226 preliminary borings were made on 14 cross sections. The most important lines of borings are located at seven different points on the Hudson [see location map]. Four of them are in the vicinity of New Hamburg, lying not more than a couple of miles north and south of that village, while three others are located within the Highlands. [See comparative geologic study in following chapter.] The chief basis of information on all but one of these lines is the wash rig, a contrivance as already pointed out that gives rather incomplete data [see Relative Values of Data, pt 1]. On this account it is not possible to give the true bed rock profiles of the river canyon even approximately except at one location, i. e. the Storm King— Breakneck mountain line. An occasional diamond drill hole has been put down on some of the others and this has been done systematically at the Storm King location in a persistent effort to determine the gorge profile and bed rock condition. The work already done has proven that in the Hudson at least the wash rig borings give wholly unsatisfactory profiles. The holes do not penetrate the boulders and heavy glacial drift that is now known to fill the canyon. The profiles, however, that were drawn from this sort of data have some value. They indicate that bed rock is still lower and that the finer silts extend down to these depths. In some places there is a heavier filling of 400 to 500 feet below them before the rock floor is reached. Wherever the diamond drill has succeeded in reaching rock the formational identification has been made and the geological cross section is a little more complete. As a matter of fact, however, at almost every locality the structural relations are so complex or so obscure that they are still not fully known. The accompanying profiles and cross sections summarize the mass of accumulated data : 1 Kemp, Prof. J. F. Buried Channels beneath the Hudson and its Tributaries. Am. Jour. Sci. Oct. 1908. 26:301-23. Some of the accompanying descriptions of river crossings follow closely this excellent summary of Hudson river explorations from Professor Kemp. i Points of exploration1 a Tuff crossing. This line is a half mile above Peggs point. Wappinger limestone forms the east bank of the river and Hudson river slates the western bank. There seems to be no abnormal structural relation of the formations. All data are from wash borings. The accompanying section gives the results. b Peggs point line. Peggs point is 2 miles north of New Hamburg. At this location Wappinger limestone forms the east bank and Hudson river slates the west bank of the river as in the previous case. The limestone dips gently westerly while the slates have a variable attitude. This is a normal relation and there is no direct evidence of any great structural break. A large number of wash borings have been made and five diamond drill holes were driven, three of them in the river. None indicate a greater depth than 223 feet, although there is a wide stretch, 1040 feet, not explored by the diamond drill. This space must contain the deeper gorge if one exists here. From the known conditions at the entrance to the Highlands, 10 miles further down stream, where the channel is known to be more than 500 feet deeper, it may be rather confidently asserted that a deeper inner channel does exist at this point. c New Hamburg line. This line crosses the Hudson from Cedarcliff to the village of New Hamburg. The river is narrow — only 2300 feet. There are no drill borings within the river channel, but there is one on each bank. Both penetrate Wappinger limestone first and then pass into Hudson river slates beneath. How much of a gorge exists here is wholly unknown except in so far as may be judged from the wash boring. There are the same reasons for believing that a gorge exists as those noted for the Peggs point line. Structurally this line is probably the one of greatest complexity. It is however perfectly clear that the abnormal position of the slates and limestone on the east side of the river is caused by a thrust fault. A similar relation of the slates and limestone on the west side must be due to a like movement, but whether they are separated portions of the same structural unit or of two adjacent ones is not clear, although they are probably distinct Five lines of wash borings were followed, and the results of these are indicated in the accompanying figures. A maximum depth of 263.5 feet is shown by these wash borings. d Danskammer line. This line is about a mile south of Xcw Hamburg. Two lines of wash borings were made, reaching a maximum depth of 268.5 feet- I" this case slates standing almost vertical form the east bank and limestone dipping gently eastward the west bank of the river. Whether there is a deeper gorge or a more complex structure here is wholly unknown. Of the three remaining lines, all of which are within the Highlands, that one projected between Storm King mountain on the west and Breakneck ridge on the east has been much the most thoroughly explored. It is known as the Storm King line. The other two have seemed to merit less attention. One crosses the river from Crows Nest mountain to Little Stony point and Bull mountain just north of Cold Spring, and is known as the Little Stony point line. The other crosses at Arden point about a mile south of West Point and Garrison. e Arden point line. Only wash borings were made. A maximum depth indicated by this method is 220 feet. Structurally this location appeared to have disadvantages, and although the evidence as to bed rock conditions is confined to the natural outcrops, there is no doubt but that it has objectionable features of this sort. The Hudson follows closely the structural control in this portion of its course. These structural elements include the foliation, the bedding of the original sediments, the subsequent shearing zones, and the strike of folds and faults. Crushed and sheared zones are nowhere in the Highlands seen so extensively developed as on the islands and the east bank of the Hudson in this, the central portion of its Highlands course. The river is very narrow, being only 2120 feet on this line. f Little Stony point line. The river here is 2360 feet wide. The rocks on each side are similar and give no clue to possible depths of channel. Less than 200 feet was reached by the lines of wash borings. Three drill borings penetrated the stony or bouldery river filling somewhat deeper — one near the center reaching 322 feet. None, however, reached bed rock. g Storm King crossing. Extensive exploratory work has been carried on at this point, both on the banks and in the river. Wash borings as usual have given poor results. Two diamond drill holes were run at an angle toward and beneath the margins of the river, and in addition a working shaft suitable for permanent use has been started on each side of the river. These have thoroughly explored the rock character to a depth of about 800 feet, it has proven to be of constant type, a gneissoid granite, affected by moderate amount of jointing, shear movements and occasional dike intrusion. The two sides are alike, the rock in depth is comparatively free from water, nearly all coming from the adjacent surface drainage. Persistent efforts have been made to use the drill in the river to explore the rock channel, but with meager results. The difficulties to be overcome in drilling in this tidal river to the necessary depth are probably greater than have even been encountered in any similar undertaking. The disturbance presented by the current, the tide, the depth of water, the drift filling above the rock channel, and the traffic in the river are a constant menace. The complex character of drift filling in this gorge, especially the occasional heavy bouldery structure, makes it necessary to reduce the size and recase the holes repeatedly. But in this regard the work has suffered less actual loss than by the menace of river traffic. Several times after the greatest efforts had been put forth in pushing the drills deep into the gorge a helpless or unmanageable or carelessly guided steamer or scow has wrecked the work. In this way some of the most critical locations have been lost together with many months of labor. The results are shown on the accompanying drawings. It is worth noting that of those holes located far out in the river channel only two have reached bed rock. Even these two have penetrated the rock so little distance that there might be still some doubt of permanent bed rock. The fact, however, that the rock found is of the right type, i. e. like the walls of the gorge, leads to the conclusion that the bottom was actually penetrated. Neither of these holes are in the middle of the river, and, although the maximum depth of 608 feet was reached by one of them, the central portion of the buried channel proves to be still deeper. One hole located near the middle was able to penetrate to a depth of 626 feet without striking bed rock. But it was finally lost. The latest results are from a boring that has reached a total depth1 (January 1, 1910) of 703 feet, the last 8 feet of which was believed by the drillers may be in bed rock. All above is drift and silt. 1 Subsequent exploration has proven that the bottom of the old channel lies still deeper. This boring has been pushed to a depth of 751 feet without yet touching bed rock (Oct. 8, 1910). 2 Discussion The present facts therefore indicate that the buried Hudson channel is more than 700 feet deep between Storm King and Breakneck ridge. Furthermore this is more than twice as great depth as has been found (so far as yet tested) at any other point either above or below this place. Although data of this kind are scarce yet there are two other borings that have given surprising results — -(a) at Peggs point and (/?) the Pennsylvania borings at New York city. Peggs point. At this place, where studies were made for a possible crossing, a hole 700 feet from shore struck rock at 223 feet and the unknown space or interval within which it is possible for a channel to lie is less than 1040 feet wide. This is about 10 miles above the Storm King crossing and in much softer rock (Hudson River slates). Yet the Storm King gorge in granite is deeper than that (deeper than 223 feet) for a width of nearly 2500 feet. Of course, there may be, and probably there is, a much deeper channel at Peggs point within the 1040 feet unexplored space. But even so there is a remarkable discrepancy in width of gorge at these two points that must be accounted for in some other way than simple stream erosion. The Pennsylvania borings opposite 33d st., New York city. The data gathered by the Engineers of the Pennsylvania Tunnel Company in their explorations for tunnel from 33d street, Manhattan, to Jersey City, have recently been made public. There are six holes into rock. Their positions and depth to rock bottom are given below : There are other shallower borings on both sides of the river. Those on the Manhattan side are represented by several different facies of Manhattan mica schist and granite and pegmatite in- Newark series. It should be noted that although only one hole marks rock bottom as low as 300' (that one situated 2180' from the New York bulkhead about the middle of the river), yet there is at least a 1100 foot space on each side which is essentially unexplored, and within one of these spaces there may be a deeper gorge. The cores taken from the east side of this middle zone belong to facies of the Manhattan schist formation, while those on the west side .belong to the Newark series. The middle one, however, is essentially a soapstone or serpentine and may be a continuation of the Hoboken serpentine belt. In any case, it belongs in age to the older series of formations. a very deep gorge, if one exists, must be comparatively narrow. Submarine channel. It is worth noting in this same connection that a submerged gorge has been mapped by the Coast and Geodetic Survey on the continental shelf from the vicinity of Sandy Hook to the deep sea margin, a distance of more than a hundred miles. This is interpreted by Spencer1 and others with apparently sound argument as the lower portion of the old preglacial Hudson gorge formed during an epoch of great continental elevation. The outer portion of this submerged gorge is very deep. That section near shore is shallow and obscure. It has been assumed that this obscurity and shallowness is due to offshore and river deposition, filling the channel with silt. No better explanation is yet forthcoming. But even here the width of the submerged gorge is suggestive. In very much softer sediments than any encountered in its whole course on present land, and in a part of its course from 50 to 100 miles below the other sections, the river has cut a gorge only 4000 feet wide at top and 2000 feet deep within a broader valley 5 miles wide. In its deepest known part the proportions are 10,000 feet in width at top to 3800 feet in depth. From this it would appear that the inner gorge type of development is characteristic of the Hudson, and that it was originally an exceedingly narrow one compared to the present river width, indicating rapid erosion during a brief and comparatively recent epoch. This submerged continental margin condition is favorable to the unexplored spaces both at New York city and at Peggs point. The only known exception and the one really surprising section is the Storm King crossing. It is too wide, considering the profiles at Peggs point and at New York city for simple normal stream erosion. That is clear enough. But a still more difficult question is whether it is also too deep. It is much deeper than any known section above or below for a distance of 50 miles. There appears to be only one satisfactory explanation of this abnormal width of the deeper section and that is by glacial erosion. Just above Storm King is the wide bay opposite Cornwall and Newburgh. The few glacial scratches observed trend about s. 150 e. The ice therefore moved to the east of south, and it is noted that the course of the river is about the same. The northern front of Storm King mountain is steep and trends east and west while the northern front of Breakneck mountain trends southwest. It would appear therefore .that these slightly converging mountain fronts served as sort of a funnel into which the ice was forced from the wide gathering ground immediately above, and through which there may have been a tongue or stream of ice of more than average power and efficiency moving almost in direct line of the present course of the river. It is reasonable to expect that these conditions would favor more than average glacial erosion. It is practically impossible to draw a complete profile for the Hudson river gorge at any point in its lower course. Even at Storm King mountain or New York city or at Peggs point, at each of which places considerable exploratory work has been done, only the broadest features are known. Nevertheless, several things have been proven and they are worth considering in this question. They may be summarized as follows : c At Storm King, located between the other two and in harder rock than either of them, a gorge at least 400 feet deep is proven to have a width of more than 1500 feet. larging by ice so far as widening is concerned is practically proven. If may also be overdeepened, by which is meant that it may have been gouged out deeper than could have been done by a stream of water alone. If ice action then be granted, the profile ought to be and probably is essentially an ice valley profile, i. e. of a more or less Ushape, rather than of typical stream erosion form. It is certain also in this case, if glacial overdeepening is admitted, that there can be no stream notch in the bottom of it. The significance of this lies in the probability that the floor is approximately the same level on a considerable portion of the bottom, so that when once the margin of this floor is touched the gorge as a whole is thereby determined for depth. After plotting the borings data and relying upon the factors that seem to be most firmly established, it appears that the following statements are as definite as the facts will warrant : a The average slope of the Storm King side of the valley above river level is nearly 380, and this is in several steps or sections of steeper and flatter slopes. The Breakneck side is about the same. b The average slope of the Breakneck side of the gorge belowpresent water level (the side on which alone there are enough data to plot a fairly good curve) does not vary much from this same value [see accompanying profile] . And it is also in steeper and gentler slopes, apparently a series of U-shaped forms set one inside the other, each inner one deeper than the next outer one. Each successive inner step is approximately 300 feet deeper than the last and 1000 feet narrower. It is certain that this sort of profile is not as simple as at first appears. The surprising feature is the close approximation of the slopes above and below present river level. In view of the fact that glacial widening has been practically proven, as shown before, not much importance can be attached to this uniformity or similarity of slope. Ordinarily such a persistence of slope would be taken to indicate simple stream origin, but having abandoned that hypothesis, the value of the angle as a factor in estimating probable total depth is lost. In short, one can not assume that the deepest point is indicated by the intersection of the slopes of the two sides. But there is one feature that is at least suggestive. That is the uniformity of the succession of steps and slopes. It was noted above that each successive inner one is about 300 feet deeper and 1000 feet narrower. If this uniformity and proportion is main- tained for the next inner one — inside of holes no. 10 and no. 22 — there would be room for only one more and its approximate depth would lie somewhere between 800 feet and 900 feet below tide. Recent drilling has shown a marked difference between holes no. 10 and no. 22. Hole no. 10 located 500 feet southeast of no. 22 is nearly 100 feet deeper. Since no. 10 is nearly straight down stream this discrepancy is disturbing. But if one considers the distance of each from the east bank it is noted that no. 10 is 900 feet out and no. 22 is 800 feet. Hole no. 10 is thus about 100 feet nearer the middle of the stream and allowing for this additional distance according to the profile as known it ought to be at least 70 feet deeper than no. 22. This corrected difference then of 30 feet does not seem to be of much importance. Summary. Everywhere in its lower course the Hudson exhibits the character of a narrow gorge, sometimes of a gorge within a gorge, most of which is either submerged or buried several hundred feet. of its course represent widths of 1000 to 3000 feet. Greater depths are believed to be maintained continuously within a narrower inner notch, but of this there is no conclusive proof and very little evidence outside of a few Storm King borings. ice erosion. The conditions indicate ( a ) rapid stream erosion while the continent stood much higher than now, (b) glaciation which enlarged the gorge in at least a few places and filled it with rock debris and later with mud during submergence, (c) finally an emergence with minor oscillations and erosion to the present time. 4 Origin of the present course of the Hudson The course of the Hudson is in most respects no more abnormal than that of the Susquehanna. Both flow across mountain ridges in such manner as to indicate their superimposed character. Both date back to the Cretaceous peneplain. But the striking feature of the Hudson is its straight course. As Hobbs and others have pointed out, the river is abnormally straight for more than 200 miles — and this in spite of the fact that it crosses the bedding and other structures of the country rock at nearly all points at an oblique angle. Such conditions are especially notable south of the Highlands where the Hudson cuts at a low angle across the ends of a succession of complex folds of the crystalline metamorphics for 30 miles to New York city. But this is true only of the east side of the river. The west bank is an almost unbroken uniform escarpment of the Palisade diabase intruded sheet underlain by Newark sandstones, which if laid down upon a pretty well planed Pretriassic surface might easily control the Hudson, and which would not differ from its present course. The most evident exception to this is the course of the river from Ploboken to Staten Island. Instead of following the line of contact between the crystallines and Triassic formations, the river cuts through the crystallines leaving large masses of serpentine and associated schist on the west side. This together with the behavior of the river in cutting across the strike farther north near the Highlands is believed to strongly favor the fault theory of location especially south of the Highlands. The same conditions would be favorable to the development of a narrow gorge and perhaps a very deep one rapidly eroded along the crush zone of the fault. From the northern entrance to the Highlands to Haverstraw bay, where the Palisades arc reached, the stream course is not by any means straight, but shifts from longitudinal structure to cross structure alternately in a zigzag manner. North of the Highlands the course is more direct again. On the whole the present explorations have added little to the facts bearing upon this question. Faults crossing the river arc common and easily recognized. Occasionally one appears to pass into the river gorge at a very small angle and not reappear. In a few places, especially in the Highlands, the course does not seem to be consistent with the hypothesis of a large fault line. It is to be expected that further work at the Hudson river crossing will add materially to ithe facts relating to the structures within the gorge. General statement This is essentially a study of the geologic features and conditions shown by exploration to have an important influence upon the choice of river crossing for the aqueduct. In the beginning it was possible to consider that any point between Poughkeepsie and New York might furnish a crossing. The early preliminary investigations showed that it would be desirable to cross either above or within the Highlands and subsequent exploratory work throws light on different possible locations in these regions. Fourteen diferent lines were tested by wash borings. Later some of these were tested by diamond drill. As data accumulated it was possible to eliminate many of the trial lines and the more detailed and critical studies became confined to a few important possible crossings. In making a comparison of them as to geological environment it is evident that they fall into two distinct groups1 [see fig. 15]One, that may be designated the " New Hamburg " group is represented by the " Peggs point, ' " New Hamburg," and " Danskammer " lines and is characterized by a series of much folded, faulted and crushed sedimentary rocks, chiefly slates, limestones and quartzites. The other, that may be called the Highlands group, is represented by the " Storm King," " Little Stony point," and the "Arden point " lines and is characterized by crystalline metamorphic and igneous rock of a much older series. A judgment as to the most desirable crossing involves the selection of one of these groups chiefly upon general geologic features, and finally a selection of a particular line upon minor differences of materials or structure. In the first place it seems necessary to consider, for each group, 1 There have been other suggestions for crossing the Hudson river, farther upstream and farther down than these — one being at New York city — but none have had sufficient claim to attention to encourage much detailed work or so careful consideration as those here discussed. A shift of position of the Hudson river crossing involved a corresponding shift of a large section of the northern aqueduct line. The first choice of location occasioned a shift southward of all that portion between Ashokan reservoir and the Hudson. the whole length of pressure tunnels whose position would be modified by a shifting of river crossing. This is because the aqueduct will approach the Hudson with nearly 400 feet head — i. e. 400 feet above river level or with an equivalent pressure. For this reason it is considered necessary to plan a rock pressure tunnel beneath the river which can deliver the water at nearly the same elevation again on the east side. Thus any one of the " New Hamburg group " involves a continuous pressure tunnnel reaching from the margin of Marlboro mountain to Fishkill range, a distance of approximately seven miles, while any of the " Highlands group " permits the substitution of two more or less separate siphon tunnels (Moodna creek and Hudson river) of considerably less combined total length. A reliable conclusion as to the choice of crossing is probably best reached through a comprehensive understanding of the geologic development of the region together with a consideration of specific local conditions. With this end in view a condensed outline of geologic history, so far as it bears upon the questions at issue, is inserted. But for a more comprehensive discussion of these matters the reader is referred to the explanatory chapter of part 1. Geology This particular locality, including as it does the Highlands of the Hudson and the district lying along its northern border, is one of the most complicated stratigraphically and structurally to be found in the entire region. The strata represented include more than half the total geologic scale reaching from the oldest sediments following the Archean up to and including a part of the Devonic series [see pt 1]. The rock types include granites, diorites, gneisses, schists, marbles, serpentines, slates, quartzites, sandstones, limestones, shales, and, less extensively, other varieties. And the region bears the evidence of no less than three periods of mountainmaking disturbances, each in its turn adding to the succession of foldings, faultings and unconformities. The oldest formation is a crystalline gneiss — a characteristic rock of the Highlands. It represents an ancient sediment that has been completely recrystallized during some of the earlier mountainmaking period. It is older than the Cambric. Interbedded with it to a limited extent are quartzite beds, ancient limestones (now usually serpentinous in character) and schistose beds ; and in it are many igneous injections, mostly granites of various types. All these igneous injections are therefore younger than the gneiss and are very large and abundant in certain cases. The granite of Storm King, Crows Nest and Breakneck ridge belongs to this type. Following the sedimentary cycle represented by the above series, and perhaps others not now preserved, the region was folded into a mountain range, the series was extensively metamorphosed and passed through a long period of erosion during which it was again reduced to sea level position and began to accumulate a new series of sediments. The lowest beds occurring upon this foundation are sandstones, now changed into quartzite. In places they are conglomeritic, and may now be seen projecting into the valleys along the Highland border. This formation is of Cambric age, and is from 200 to 600 feet thick in favored places. It forms an almost continuous belt along the north side of the Highlands except where cut out by faulting, and extends with similar breaks beneath the later sediments northward. This quartzite is known as the " Poughquag." Upon the quartzite of this series there was developed a succession of limestone beds at least 900 to 1000 feet in thickness. This formation is known as the " Wappinger " and includes some beds that are of Cambric but for the most part of Ordovicic age. The final member of this series is a shale and shaly sandstone in places changed to slate. It is quite variable in actual character and has a great thickness, never yet successfully estimated, but probably several thousand feet. This is the so called " Hudson River slate " series. In this region they are of Ordovicic age. This is the succession which the proposed Hudson river lines has to penetrate in a pressure tunnel. Later Siluric and Devonic strata lie in the immediate vicinity of this alternative line, but add no complication to the problem as it now stands. Therefore no other formations need be considered except the glacial drift. This covers almost every rock surface and is deeply accumulated in some places, notably in the narrow gorges and valleys, obscuring the finer original topographic lines. injection, erosion, and perhaps other sedimentations ' The metamorphosed schists, limestones, quartzites etc., together with accompanying intruded igneous masses — forming the basal gneisses of the Highlands The evidence of such succession and history gathered from the scattered outcrops of rock in the immediate area, is nowhere better shown than in the field covered by this investigation. 2 The succession in many places is not normal. Often a whole formation or even two of them are missing and formations that should be separated are brought side by side. Faulting therefore is prevalent and the occurrences show that these large fault lines usually run northeast and southwest. the southeast. 4 This same movement causes the faulting to be largely of the overthrust type, and in some cases the lateral displacement attained in this way may possibly be several thousand feet. 5 Isolated " islands " of the older rock formation appear out in the later sedimentary area. They all seem to belong to prolongation of the ranges of the Highlands and their abundance undoubt- 6 The Highlands area terminates in a serrate margin which, in the latest thrust movements from the southeast, must have created very unequal distribution of stresses within the slate-limestone region to the north causing additional cross folding and faulting. For the most part these can be traced only a short distance before losing their identity. In a mountain folding movement, the uppermost rocks are most broken and displaced or crushed while those of greater depth may be bent or uniformly folded or even recrystallized. It would appear that this latter was the condition of the Highlands rock series during its earlier history. And even in the latest movements its lines appear to be less radically disturbed than the slates and limestones to the north. Most of the disturbances that invite serious consideration belong to the latest period of these mountain-making upheavals. Comparison of routes i New Hamburg group. This group of crossings is in the later sedimentary series. Hudson River slates and Wappinger limestone are the chief formations. But within the southern third of the tunnel, at least, the underlying Cambric quartzite and the older Highland gneiss would be cut — the quartzite possibly three times. The succession therefore will be of considerable complexity as a whole. All of the formations involved are thrown into very steep dips at most places and are consequently liable to rapid and unexpected changes — some of which probably do not show at the surface. There are several fault lines belonging to the major northeast and southwest series to be crossed by such a tunnel — one of them in each case being met at considerable depth and beneath or adjacent to the river. These faults besides being the weakest zones of rock as a rule, are in addition the most unstable in any possible future earth movements. Although there is no evidence of recent displacement along these lines, still such a thing is always possible and recent serious effects of this kind on the Pacific coast suggest caution. It is manifestly advisable, if possible, from every standpoint to avoid crossing several of them. In the field there are numerous springs of very large flow along many of the limestone borders. The concentration of them to these situations in addition to the occurrence of an occasional sink- hole, leads to the conclusion that they are more intimately dependent upon the limestone structure for their existence than upon the glacial drift or any superficial factor. Their abundant flow, sometimes on high ground, indicates rather extensive structural connections and this is believed to be the limestone bed itself and that such flows would be encountered also in depth. The occurrence of sinkholes suggest also possible solution channels and cavities and distant outlets. The types of rock to be encountered on the lines represented by this group are easily workable. Among them all the Hudson River slates is probably the most satisfactory from any standpoint. It is generally easy to penetrate and has a capacity for healing its own fractures. For this reason it can be considered good ground, tight and safe. But a considerable distance of the tunnel can not be kept in slate — perhaps even more of it than can be proven from surface observations. The other formations are considerably less satisfactory. The limestones are in places shattered and are liable to abundant flow of water. The quartzite is extremely hard, as difficult to penetrate as granite, and where crossed by the faults is probably not healed at all, while the gneiss is doubtless of similar character to that of the Highlands crossings to be discussed later. Only minor modifications result from a choice of the individual crossing, whether " Peggs point," " New Hamburg," or " Danskammer." In one of them, New Hamburg, it would appear possible to cross the actual river section wholly in slates. This seems to be the reasonable conclusion from the diamond drill boring at Cedar Cliff. But even that line necessitates crossing at least two fault contact lines immediately at the east bank and beneath Wappinger creek at depths not immensely less than that below the river itself and both wholly within the range of influence of the river waters. It would appear therefore that the situation is not materially altered in the present discussion, no matter which particular crossing of this group is considered. 2 The Highlands group [see cross section]. In this group of crossings there are two separate features to consider, (a) the Moodna creek valley which these lines all cross, and (b) the Hudson river itself. Their characteristics are as follows : a Moodna creek [sec separate Moodna creek discussion]. So far as known Moodna creek can be crossed almost wholly in slate. It is possible that the underlying limestone may come near enough to the rock floor of the valley to be penetrated but there is little direct evidence of it. The ancient valley is deep and probably marks a line of displacements which can not be avoided, no matter what route is chosen. The fault contact at the border of the Highlands is not expected to prove troublesome as it seems very tight at the exposures seen. The buried granite ridge (a continuation of Snake hill) which underlies the western end is now known to come within the limits of the tunnel and adds one more complication. Except for the fact that the ancient Moodna valley is deep and filled with heavy drift that is unusually difficult to prospect, there would seem to be no source of special trouble. It has no lines of weakness that are not also present in the more northerly districts and the tunnel has chances of crossing them under more advantageous conditions without so much complication with the limestone series as characterizes the New Hamburg group. b Hudson river. Among the Highlands group of crossings there is considerable difference of structure dependent upon the exact location of the crossing. The conditions that prevail may be summarized as follows : (1) Storm King location. This is wholly in massive and gneissoid granite. The rock is the most massive and substantial body of uniform type found in the Highlands. The course of the river indicates some weakness in that direction. This weakness may be some minor crushed zone or even the jointing alone that prevails throughout the exposed cliffs. But there is no direct evidence of faulting, cutting the line and such crushing as may be encountered is believed to have originated at such depth and under such conditions as to cause no large disturbance. The freedom of this formation from all bedding structures and natural courses of underground water circulation on a large scale is an additional factor. There is absolutely no other place, within the region, where the Hudson river can be crossed from grade to grade in good ground of a single type with so great probability of avoiding all large lines of displacement. (2) Little Stony point location. The conditions that prevail at this point are similar to those that characterize the Storm King line. The only known difference is in the considerably more shattered condition of the granite, especially on the west shore at Crows Nest. It is estimated that this crossing is less favorable by reason of just this poorer condition of the rock and the somewhat greater yielding to regional disturbances that it seems to indicate. It is largely an ancient stratified series much metamorphosed containing belts of interbedded limestones, quartzites, and schists, in addition to the more substantial feldspathic gneiss. The eastern bank of the river bears also abundant evidence of extensive crushing and shearing and is believed to indicate a displacement in this zone. For these reasons the West Point crossing is considered an unfavorable route compared to either of the others of the Highlands group. Summary. In a comparison of the geologic features that are of most importance in contrasting the possible routes for the Hudson river crossing the following points are considered of most importance. 1 The New Hamburg group of crossings involves (a) the longest tunnel, (b) the more complicated structures, (c) the greatest number of known faults, crush zones, and related disturbances, (d) the more variable series of rock types to be penetrated, (e) the greater tendency to encounter heavy underground water circulation, (/) the greater probable susceptibility to disturbance from future earth movements, and (g) the greater number of uncertainties of rock relations. 2 In contrast the Highlands group admits of (a) shorter total tunnel length, (b) the most profound fault lines of the district are crossed either in high ground or are avoided or, because of the rocks involved, promise the least possible trouble, (c) the Hudson river itself can be crossed in a single formation with probability of avoiding lines of largest structural weakness confining the greatest pressures and deepest tunnel work within the most uniform and substantial rock of the whole region. There are, of course, many unknown or only partially known features obscured beneath the covering of drift or lying beneath the river itself ; but, however many there may be, it is not believed that they can materially change the general situation. The major characteristics are so well marked that any addition to those already known would in all probability increase the difficulties of the New Hamburg group of routes at least as much as and perhaps more than those of the Highlands group. In view of the above facts and inferences the judgment has been in favor of the Highlands group of crossings as the more defensible on geologic grounds as a route for the aqueduct line. Furthermore, in accord with the preferences already noted, the Storm King location is regarded as the most likely to give satisfactory results. Quality and condition of rock The rock of Storm King mountain and of Breakneck ridge at the Hudson river crossing is a very hard granite with a gneissoid structure of variable prominence. The color varies from grayish to light reddish and the structure is always coarse passing into pegmatite facies that occur as stringers or irregular veinlets. The grayish facies is of slightly finer grain and more gneissoid. Those portions that have been sheared are still darker. There are many joints at the surface running at various angles and an occasional slickensided surface. The mass is cut by several dikes of more basic rock (diorite) of widths varying from a few inches to 8 feet. These dikes are somewhat more closely jointed than the granite and consequently a little more readily attacked by the weather. But where protected they are equally substantial for underground work. The chief variation from ibis condition is where crushing or shearing has induced metamorphic changes. Wherever bed rock has been reached at this point and to such depths as workings have penetrated the rock is of this type. The work includes (a) four inclined drill holes from the river margin — two starting from the surface and two from chambers set off from shafts at a starting depth of about 200 feet, (b) several vertical holes in the river itself, and (c) two large working shafts 20 x 20, one on either side of the river. These give all the data1 known as to the condition at depth. From them it is apparent that crushing and shearing have been prominent. Many splendid specimens of crush breccia are thrown on the shaft dump. But its present condition at the depth involved is sound and durable. The fractures are rehealed. There has been a recombination of constituents giving a new matrix of complex silicates among which epidote is the most characteristic, while simple decay is of little consequence. For strength and permanence the conditions could not well be improved. There is no reason to apprehend any change for the worse for the reason that the same tendencies must prevail at that depth throughout. It would appear therefore that faulting movements, or the existence of a fault zone of importance can not become a serious obstruction, because of the tendency to 1 Since this paragraph was written four inclined diamond drill borings have .been made from chambers at depths of about 200 feet in the shafts. These have now penetrated the whole distance beneath the Hudson with very satisfactory results. before. It is noted elsewhere that faulting is common in this region, and that in a considerable portion of its lower course the Hudson probably follows such structures. It is, however, wholly unnecessary to assume that its whole course is a fault line. WJiether or not there is a longitudinal fault zone of any prominence in the river at Storm King is unknown. There are several cross faults, both above and below this point, that give much clearer surface evidence of their presence. Fault zones have proven to be objectionable ground in many places along the aqueduct line, but elsewhere the data refer chiefly to situations favoring more ready underground circulation, i. e. at higher levels. In this particular case the rock in question lies below former ground water level within the belt of cementation rather than up in the belt of decay, and there is probably no disintegrated rock from any cause. SITE FOR THE ASHOKAN DAM Topographic features of the southeastern margin of the Catskills, where the chief water supply is available, fixes the approximate location and bounds of the principal reservoir. The accompanying map, a portion of the western part of Rosendale quadrangle, shows the situation. The part of the work involving the chief geological problem was the choice of the principal dam sites on the Esopus. This is known as the Ashokan dam. This part of the Catskill system belongs to the Reservoir Department under Mr Carlton E. Davis as department engineer. There were originally considered three sites: (i) at " Broadhead bridge," (2) at " Olive Bridge," (3) at " Cathedral gorge" or the " Tongore " site. Any one of these seemed possible from a topographic standpoint. Later developments in regard to storage capacity and engineering considerations finally reduced the practicable sites to two — the ''Olive Bridge" and the "Tongore." These were then explored thoroughly as an aid to determining whether or not there were favorable or unfavorable conditions at either location. Trenches were dug, shafts were sunk, wash holes were put down, and drill borings were made. The amount of such work done was sufficient to show the actual conditions both of the drift and bed rock and incidentally to throw some light on minor matters in geologic history. This discussion is essentially a summary of these data and a comparison of the geologic conditions indicated by the explorations1 of these two sites and a statement of some of the geologic characteristics of the area. 1 General geologic conditions as shown by the explorations Bed rock is dark colored Devonic sandstone and shale, the Sherburne formation, lying almost horizontal, strongly jointed, plainly bedded, and of good quality for the foundation of the dam. At both locations the present Esopus flows in a postglacial gorge 1 In this work of exploration a very efficient staff of engineers was engaged. Among those having very much to do with the features here discussed are Thaddeus Merriman, division engineer, J. S. Langthorn, division engineer and Sidney Clapp, assistant engineer. and there is a somewhat deeper huried channel a short distance to the north side. In each case this old channel bed rock is probably less fresh and substantial, due to former weathering, than the present exposed surfaces. In each case glacial deposits reach a thickness of more than 200 feet within the narrow valley or gorge, especially along the north valley wall within the limits of the proposed dam. Special geological conditions. The factors in which there is most variation and which are of most significance in a comparative study are those belonging to the glacial drift deposits. In order to properly estimate the influence of some of these features it will be necessary to briefly consider the types of material represented at different places and the conditions under which they were formed. Types of material. Till. Heavy bouldery till, mixed clay, sand, gravel, and boulders, is the most abundant type of material. It forms especially the chief surface material throughout the region, and is the surface type at both sites. It becomes at places quite sandy, but is almost everywhere good, impervious material because of its mixed character. Laminated till. At a few places, notably in the Beaver kill near its mouth, and in a trench above Olive Bridge, and in the " big ciugway " above West Shokan, strong lamination appears in heavy stony till as if laid down rapidly in comparatively quiet water such as the margin of a lake. This material is especially impervious. Gravel hillocks. A few small hillocks with morainic contour, indicating a dumping ground for some glacier on a small scale, occupy the flat immediately west of Browns Station. They were, at a very late stage, piled into the course of a former glacial stream whose delta deposits occupy the sandy bench above the 500 foot contour just north of Olive Bridge. Assorted gravel and sand. This material is abundantly developed just north of Olive Bridge. It seems to have formed a delta deposit at the mouth of a glacial stream that emptied into the main valley at this point. The running water washed almost all of the clay and extremely fine material farther out, where they settled in the bottom of a small glacial lake that was at that time held in this upper portion of the Esopus valley. The dam that held in this body of water which reached above the 520 foot line stood near the proposed " Olive Bridge " dam site. The materials forming the dam were in part the glacial till that is now found on that site and in part the ice itself, which came in from the northeast, helping to complete the barrier. Into this lake the streams from the melting ice margins deposited their load of silt. This is well shown in the trenches cut across the terrace }i of a mile above Olive Bridge. A similar occurrence is seen at the cemetery near West Shokan. Laminated sand and clay. In all cases where silts were carried into the lake basin the finest materials were carried in suspension to greater distances from the margins, and slowly settled out in the form of alternate laminae of clay and fine sand. Each sandy layer represents a fresh supply of material and rapid precipitation of the comparatively heavy grains ; while each clay layer represents a period of greater quiet or decreased supply during which the finest particles settled to the bottom. A predominance of fine sand indicates either abnormal supply or proximity to the supply margin, while a predominance of clay represents either uniform and moderate supply or greater distance from the supply margin. These deposits are nearly impervious to water moving vertically, but much more pervious laterally and especially so in the most sandy portions forming the marginal facies. This type of deposit is to be seen at the surface at about the 700 foot contour 2 miles north of Shokan, above the " big dugway," also in the trenches cut into the terrace at about the 500 foot contours Y\ of a mile north of Olive Bridge, and it is probable that this same type underlies the northern half of the " Tongore " site. The material marked " fine sand " at and below the 400 foot line on the accompanying " geologic section " G-H is judged to be of this type. distribution. Gravel streaks and assorted pebble beds. Wherever water flowed with considerable current across the material either before or after deposition the finer particles were removed and only gravel and pebbles, too heavy to transport, were left behind. Some of these gravel beds were developed in the intervals of successive advances and retreat of the ice when for a time the lower valleys were unoccupied. In many places the succeeding advance of the ice would plow all these surface materials up again and mix them into the usual till ; but occasionally the oncoming glacier simply covered these deposits with its own till mantle, and they are preserved as records of these minor interglacial stages. Such behavior would be more likely to occur in the deeper channels. To this class of deposit belong some of the gravel beds of the " Tongore " site, notably that shown in one of the deep shafts. It is probable that the zones where the wash rig experienced a " loss of water " are most of them of this type. In preglacial time the Esopus valley was occupied by a stream of similar capacity to the present Esopus creek. Its channel lay to the north side of the narrow valley, having adjusted itself in conformity to the slight dips of the Hamilton sandstones and its principal joints. At the points under investigation this original channel is buried under several kinds of glacial deposits whose source of accumulation was chiefly from the north and northeast, blocking the stream channel and forcing the stream to the opposite (south) side. The direction of movement was favorable to the damming of the Esopus creek valley and the deposits indicate that this occurred at several different times and at different elevations and that corresponding lake conditions occasionally prevailed. It is equally clear that there were intervals of retreat of the ice with attendant stream action and the development of gravel beds, followed by another ice advance, either obliterating the surface features or covering the previous deposits with another till layer. With each successive withdrawal the local streams found themselves more or less completely out of place, and consequently their characteristic deposits formed in these intervals may be found in unlooked for places wholly inconsistent with present surface contour. At the final withdrawal of the ice, Esopus creek found itself entrenched along the southern margin of the valley and has cut a postglacial rock gorge instead of removing the compact till from the original channel. But wherever only modified drift, either sand or clay, was the valley filling it scooped out great bends so that a large proportion of this type has been removed from the valley, and only the margins remain as terraces or covered beneath other protecting deposits. On Act At Fig 16 Location of the Ashokan dam at Olive Bridge site and a geologic cross section. The small dots in the plan indicate exploratory borings. The section shows the rock profile indicating a preglacial channel of the Esopus. The present Esopus flows in a new postglacial ^channel at a higher elevation. The lowest materials in contact with bed rock are heavy stony till, laminated till and stony laminated clays — all good impervious material wherever exposed and tight upon bed rock. Sands and laminated clays are extensively developed immediately northward of the site and streaks of these deposits interlock to a limited extent with the till materials of the site itself, but they do not extend far and die out in wedges among the heavy deposits that characterize the southern slopes of the hill forming the northern terminus of the dam. These pervious streaks do not extend at any point continuously through this hill and consequently as a whole the present barrier as it stands is practically impervious. The poorer materials (assorted gravels and sands) characterize the upstream side, and the better, more impervious materials (till and laminated boulder ■clays) characterize the downstream side of the proposed Olive neering factors permit. b " Tongore " site. At Tongore, bed rock is at least a hundred feet deeper than at Olive Bridge. In the deeper parts, below the 400 foot line the deposits as indicated by the wash borings [see sections] are interpreted as a fairly continuous succession of till, stratified sands and gravels, and laminated sands and clays belonging to two or three different stages of accumulation. Upon tins the heavy upper till was laid down. It is believed that the records fully support this view and that the stratified or laminated materials were accumulated at a time when a temporary dam existed at some point still farther down the Esopus valley. It is apparent furthermore that the most porous zone is at the junction of the upper till and the lower stratified deposits and in part is represented by the assorted pebbles of stream wash — in general not far from the 400 foot line. These middle zone deposits are believed to extend continuously through the drift ridge that forms the northern half of this site. As before noted, though rather impervious vertically, Fig. 17 Plan and geologic section at the Tongore site. The dots on the map indicate exploratory borings and the course of the buried channel of the preglacial Esopus creek is shown making a right angle bend to the north. The section shows the buried channel, the new postglacial channel and the great accumulation of porous modified drift which is regarded as one important objection to this site for the dam. some of these deposits allow ready lateral movement of water. This is held to account for the rather persistent occurrence of springs or seepage along the creek bank at about this level both above and below the site. The great thickness of these laminated beds, in places a hundred feet or more, together with the abundance of sand in them, and the caving tendencies exhibited by them in one of the large shafts, indicates poor conditions for such a piece of work. The behavior of one of the test shafts throws some light on conditions within the drift deposits. At this place after sinking into the underlying gravel beds there was " no water " at first, but after going a few feet deeper there was an abundant flow, that did not rise much in the shaft. This case seems to support the following interpretation. The gravels encountered do not form an isolated pocket or lens, else it would have carried water full from the first. It must be a fairly continuous porous zone with large feeding connections else it would run dry, and it must have an easy discharge else it would have risen above the level of the first gravels. Therefore it must be a rather well marked subterranean water passage or porous zone of considerable extent. Such conditions would make an impervious core wall to bed rock at this site a necessity and its construction a matter of considerable difficulty. At this site also because of the small cross section of the ridge, there is little chance for the interlocking of layers or the blocking of the porous ones by a till barrier to check the lateral seepage, and there is no chance to move farther down stream to secure such conditions. Because of the (a) higher bed rock throughout, and (b) the more uniform and impervious quality of drift deposits, and ( c) the more massive cross section of drift barrier for foundation, and (d) the perfectly tight contacts of till and bed rock, and (e) the limitation of the more porous materials to higher levels and (/) the glacial history connected with the development of all these parts. " Olive Bridge " is the preferable location for the proposed Ashokan dam on Esopus creek. STRUCTURAL PURPOSES Probably no stone marketed in New York State is more extensively known than the " bluestone " of the Catskill region. But it is noted particularly for a special purpose, i. e. as flagstone, because of its capacity to part or cleave into thin slabs. These slabs are proven by experience to have remarkable weather resistance and durability. Little attention has been given to the question of dimension stone — whether or not such blocks of as high quality as the flags could be obtained and where such quarries could be opened. There are several reasons for this situation. In the first place (i) the stone is of a dark color and has a dull appearance so that it is not fancied for the usual expensive structures where large sizes are used, also (2) the quarries are small, shallow, and are worked on a small scale by single individuals or groups of neighbors with few quarrying tools and no transportation facilities for large material, and in addition (3) considering the work and equipment necessary and the demand the flag industry was more profitable. Because of the large demands of the Ashokan dam where nearly a million cubic yards of heavy masonry construction are to be used an entirely new situation has developed. It is especially desirable that a rock capable of furnishing heavy dimension blocks should be discovered. The usual slab or flag type is unsuited to a considerable part of this work. A study of the adjacent region therefore has been made and explorations along certain promising lines have been conducted to sufficient completeness to prove that a suitable stone can be furnished in large quantity. The characteristics of structure and occurrence as shown by this special study are given, together with some of the later exploratory data. Physiographic features1 All of the rock formations are sedimentary, chiefly sandstones and shales. They lie in alternating beds of variable thickness and are almost horizontal. The total thickness is many hundred feet so 1 The principal argument of this discussion has been used in a previous article by the writer under the title " Quality of Bluestone in the vicinity of the Ashokan Dam" in the School of Mines Quarterly, v. 20, no. 2. in this locality. The region is one of considerable relief representing preglacial erosion. The glacial drift mantle has modified it chiefly by obscuring some of the smaller irregularities of rock contour, and especially by partially filling many of the stream gorges. Postglacial erosion has not completely reexcavated the old channels. But the contour of the uplands reflects the character of the bed rock with considerable success. The tendency of the more massive and coarse grained varieties of rock to resist weathering and erosion more successfully than the finer grained and more argillaceous or shaly facies is a general characteristic. Since these varieties form successive or alternating beds throughout the whole area, the result is an almost universal cliff -and-slope surface form. This bed rock topography is somewhat obscured but not wholly obliterated by glacial erosion and deposition. Therefore it may be used with confidence in locating or tracing the more durable beds since they almost invariably appear as a shelf or terrace with a steep margin toward the lower side and a gentle slope on the rising side. The rock types include bluish gray or greenish gray sandstones with almost horizontal bedding, and sometimes exhibiting crossbedding structure, and compact very dark argillaceous shales. These two are of about equal prominence, but only the sandstone is of importance in the present discussion. Tts minute structure will be given in greater detail in the petrographic discussion. Jointing is common and persists in two sets nearly at right angles to each other — one striking northeastward and the other toward the northwest. In some of the best exposures, these joints are clear-cut and run 10 to 18 feet apart, dipping almost vertically. In the more massive beds there is very little small jointing, so that the character is especially favorable to large dimension work. But still more prominent structures are the partings which follow the bedding planes. These give the rock a decided tendency to cleave naturally into slabs, the uppermost exposed portion of almost every outcrop exhibiting this slab structure in more or less perfection. So general is this structure at all horizons in the sandstones of the series that there can be no doubt of its connection with some original sedimentation character. Besides it is a potential factor in nearly all the beds even when not very apparent. The exposed places exhibit the character so prominently only because of the weathering effect, which develops the natural tendency. This general conclusion is borne out by the well known practice of quarrymen of the district of splitting the larger blocks into slabs of the required thickness by wedges driven along certain streaks that are known as " reeds." A reeding quarry is one that has this capacity well developed, and it is this character in part that has made the " bluestone " or " flagstone " of New York an important factor in the production of the United States for a great many years. For large size dimension stone where great stress is involved it is evident that this structure would not be desirable. These definite planes of weakness reduce the general efficiency. A little observati jn however shows that there are some outcrops and an occasional quarry where the more massive blocks do not split well. From the necessities of the industry these have been avoided or but meagerly developed. In some cases of this kind the sedimentation is of the cross-bedded type with somewhat interlocked laminae. If the grain is coarse such varieties resist splitting with great success. The thickness of such beds varies from a few feet to 25 feet or even more without prominent interbedding of shale layers. Stratigraphy. These are the sandstones, flags and shales known as the Hamilton, Sherburne and Oneonta formations belonging to the Devonic period. The strata of the immediate vicinity of this examination belong to the Sherburne subdivision, but no attempt to differentiate the formations was made. Structurally and petrographically the different formations are not distinguishable in this area. On the market the stone from either is known generally as " Hamilton flag " or " Milestone." Economic features There are hundreds of quarries in this general region. The product is almost wholly thin slabs of the flagstone type. This is supplemented by a small amount of somewhat more massive character, dressed for window sills ; and a very limited output is of dimension stone of larger size. The general lack of suitable mechanical devices and transportation facilities are the chief reasons for the limited output of the last named grades. quarries whose field geologic features give promise of encouraging results. The most characteristic variations are illustrated in the accompanying photomicrographs, plates 22, 23. Texture. The rock is granular, the individual grains varying from minute particles in the finer shale layers to three or four tenths of a millimeter in diameter in the coarser sandstone [pi. 23, lower figure]. The grains are seldom rounded. Jagged or frayed or elongate forms are the rule [pi. 23, upper figure]. There is no marked porosity. When the rock was first deposited as a sediment it probably had the usual large interstitial spaces of such rock type, but in this case some subsequent modification — an incipient metamorphism — has largely obliterated the voids by the introduction or development of mineral matter of secondary origin. inally more rounded than its present representative. Mineralogy. The original minerals in order of abundance were the feldspars, quartz, and probably hornblende, biotite, and in much smaller amounts others of little apparent consequence in the present discussion. All of these have been more or less affected by subsequent changes. Quartz has suffered least of all, the chief modification being a greater angularity of form and an occasional interlocking tendency caused by secondary growth [pi. 22, lower figure]. Both orthoclase and plagioclase feldspars occur. The orthoclase grains, which originally made up more than half of the bulk of the coarser types of rock, have been in places profoundly altered [pi. 22, upper figure]. In many cases the identification of this mineral depends upon its association and the abundant remnants of characteristic structure and its normal secondary products. In the least affected grains satisfactory identification is not difficult. Even in the most modified representatives there is some preservation of structure indicating size of grain and proving the essentially granular character of the rock. The plagioclase, although not abundant, is more readily detected than the orthoclase because it has been much less affected by the secondary changes. All original ferromagnesian constituents are wholly altered. There were some such constituents in the rock, as is plainly shown by the secondary products. Hornblende and biotite were probably both present. Plate 22 Photomicrograph of bluestone, x 25 diameters. The clearer grains are quartz and indicate the approximate size of other original constituents. In this case the alteration of the feldspars and ferromagnesian originals is so complete that their products form an indeterminable complex aggregate of closely interlocked granules, flakes, and fibers of extremely fine texture. Photomicrograph of first grade medium grain bluestone, x 25 diameters. Taken to show angular and interlocking grains indicating secondary growth and a complete lack of reeding structure. The clear grains are quartz; the rest of the field is made up chiefly of secondary derivatives from the original feldspars and ferromagnesian minerals. quartz as the most important and abundant. Others probably occur that are less readily differentiated, and among them is kaolin. Occasionally a small amount of massive or granular pyrite occurs. There are traces of organic remains, especially plant stems, and the pyrite is most plentiful in association with those beds. It seems to be the secondary products largely that give the characteristic bluish or greenish color to this stone. Practically all of the iron freed by secondary changes from the ferromagnesian constituents has entered into new silicate compounds, especially with the chlorite, which are minutely distributed throughout the whole mass, giving it all a tinge of the characteristic color of these well known products. The same amount of iron in the oxid form would no doubt give as highly colored stone as any of the reds or browns of other familiar types of sandstone. But the tendency to form the sericite-chlorite-quartz aggregate in the rock has also an important bearing on its durability and strength. This is further discussed in a separate paragraph. Classification. It is clear that this type of bluestone is a sedimentary rock of medium grain, a sand rock or " renyte." Since the silicates are so predominant in the original composition it may be further identified as a sandstone or a " silicarenyte." But in view of the predominance of the feldspars it should be further designated as an arkose sandstone. And considering the extent to which it has been modified by the development of interstitial silicious products and the effect that this has had in perfecting the bond between the grains, the rock may be classified as an indurated arkose sandstone. Special structure. A study of the cause of reeding, or the tendency to split into slabs, led to the preparation of thin sections of this structure [pi. 23, upper figure]. It is apparent from them that the reed is strictly a rock structure and that the perfection of the capacity to split along these planes depends wholly upon the abundance and arrangement and size of the elongate and semifibrous grains and the presence of a more than usual amount of original fine or flaky material. Almost universally the reed streaks are darker in color and finer in grain than the average of the rest of the rock. In part therefore it is an original character due to the assorting action of water during deposition, finer streaks alternating with coarser ones in accord with ordinary sedimentation processes. But, in addition to that, the subsequent changes that have affected the whole rock have occasionally accentuated the structure by a ten- dency of the whole rock to develop elongate or fibrous aggregates. It is probable therefore that the parting capacity is in places considerably increased by the very process that has produced just the reverse results in the more heterogeneous portions of the beds. Under a sufficient stress the rock will part most easily along the planes where this foliate or fibrous character is most persistent. Even in these cases, however, it may not indicate that the rock is essentially weak. It simply locates the most vulnerable point in the stone. In many quarries these streaks are so abundant that only thin slabs can be obtained — the disturbances of ordinary quarrying being sufficient to cause parting. The deeper portions of quarries are, however, much less subject to such behavior. In all cases the greater slab development of the exposed portion of the ledge is an ordinary weathering effect, by which the same results are obtained slowly and naturally and more perfectly than can be secured artificially on the fresh material of the same beds. The expansions and contractions of changes of temperature, together with the rupturing effects of freezing water caught in the pores, serve finally to weaken every part of the rock. In this process the prominent reed lines give way so much in advance of the rest of the rock that they develop into true rifts and separate slabs appear. It must be appreciated that these ledges have been exposed an immensely long time compared with the probable requirements of any engineering structure, and that this weathering tendency does not mean a speedy disintegration of the freshly quarried blocks. Still it is advisable to avoid as many sources of weakness as possible and one of the ways is to select ledges where the stone does not have a reeding tendency, or in which the reed lines are interlocked, or wavy, or interrupted. These requirements are most fully met in the coarser beds and especially those exhibiting some cross-bedding. Two local quarries meet these demands to a marked degree. Strength. The better qualities of bluestone have great strength. Even the reed lines are in many instances stronger and more durable than the regular quality of some other sandstones that are usually considered suitable building material. The secret of this exceptional strength lies in the modifications of texture that have resulted from the alteration and reconstruction of the mineral constituents. The breaking up of the orthoclase feldspar, and the accompanying changes in the ferromagnesian minerals, have furnished considerable secondary quartz, which has in part attached to the original quartz grains making them more angular and de- lelism of elongate grains. Photomicrograph of best grade coarse-grained Milestone. Taken to snow a quality m which the granular character is still well preserved. , 'i ! i"' SLains,are quartz, the others are chiefly feldspars somewhat "Alined. ine close interlocking and the development of fibrous or trayecl structure and the bending or wrapping of some constituents are secondary effects. veloping an interlocking tendency [pi. 22, lower figure]. At the same time the fibrous sericitic and chloritic aggregates have developed to such extent as to fill most of the remaining pores, and in many cases the fibrous extensions have actually grown partly around the adjacent quartz grains [pi. 23, lower figure]. The effect has been to develop a silicious binding of unusual toughness. This combination of changes has made a rock that is now remarkably well bound or interlocked for a sedimentary type. Durability. First-class stone of the grades indicated above would have as great durability as any stone in the market, except perhaps a true quartzite. With the exception of the almost neglectable quantities of pyrite, occasionally found, there is no constituent prominently susceptible to decay. The rock as a whole mineralogically is stable and its texture indicates unusual resistance to ordinary disintegrating agencies. From the microscopic study it is clear that the variety of rock most fully meeting the demands of heavy exposed construction are the coarser beds and those freest from reed and shale. from the Olive Bridge site. From additional explorations it is certain that ledges of high grade rock occur, and that the grade varies rapidly in the same bed and that suitable material can be obtained in the immediate vicinity of the Ashokan dam. No doubt rock of equally high quality may be obtained at many other localities. THE RONDOUT VALLEY SECTION Because of the fact that the hydraulic grade of the Catskill aqueduct as it approaches the Rondout valley is nearly 500 feet A. T., an elevation more than 300 feet above the lowest portions of the valley and more than 200 feet above very large areas of it, a total width of more than 4 miles being too low for unsupported construction of some kind, and because of the general policy of using the pressure tunnel system so as to deliver the water at a corresponding elevation on the east side of the valley, and further because of the very complicated geological features of the district this section has been the seat of very extensive and interesting explorations. Undoubtedly a greater number of obscure features occur here than on any other single section of the whole aqueduct line. Most of these features are readable from surface phenomena in general terms. In all cases the indications are plain enough to serve as a guide to well directed tests, but many points of critical importance can not be determined with sufficient detail and accuracy of position for such an engineering enterprise without systematic exploration.1 The basis and results of this line of investigation which has occupied the greater part of two years are summarized and plotted in the following discussion and charts. The portion receiving special study is in the vicinity of High Falls. General geology Almost everywhere the surface is glacial drift. Where outcrops of bed rock occur they habitually present the unsymmetrical ridge appearance usually with a more or less sharply marked escarpment on one side and a gentle slope on the other. The strike of these 1 These explorations belong to the Esopus division of the Northern Aqueduct Department. The earliest reconnaissance was done under the direction of James F. Sanborn, division engineer, who was subsequently assigned to geologic work over a considerable portion of the Aqueduct line. The development of exhaustive explorations and final construction on this division has been carried on under Lazarus White, division engineer, assisted by Thomas H. Hogan. The division has been recognized from the beginning as an important one and in many ways one of the most complex. Thomas C. Brown, now professor of geology in Middlcbury College, was employed for a year on this division during the later exploratory work. Formations. The following distinct stratigraphic units are determinable in this valley every one of which will be cut by the tunnel beginning at the west side with the youngest formations : Approximately 4775 These occur in belts in succession more or less regularly from west to east. Most of the formations are quite uniform in the Rondout valley. The Shawangunk conglomerate is probably more variable than any other as shown by borings. Because of this general persistence of formation it is possible to estimate approximately the depth at which any particular lower member lies if some starting point can be identified. [For detailed description of the formation, see pt 1] Structure. The principal irregularities are structural, rather than stratigraphic. The region on the west side of the valley, the margin of the Catskills, is but slightly disturbed and lies very flat, but the region on the east side, the Shawangunk mountain range and the cement district, has an extremely complicated structure. The Rondout valley, lying between them, is a transitional zone and passes from gentle dip slopes and folds in the westerly side to more frequent folds and thrust faults on the easterly side. In at least two thirds of the valley it would appear from surface evidence alone that the formations would dip uniformly westward, the only suspicion of additional complication being given by an occa- sional minor fold seen in the river gorge or an escarpment where the sedimentary character alone would hardly account for it [see pi. 24, High Falls]. Explorations have shown that the evidence of the minor structures is reliable and that disturbances occur at some places even to the extreme western margin. Physiography. In spite of the drift cover which obscures many original inequalities it is readily seen that the prevalence of the gentle westerly dip over most of the area, together with the succession of so many different beds of varying resistance to erosion, have allowed the development of a succession of long dip slopes and steep escarpments on a more pronounced scale than the present topography shows. It is clear that the Rondout is really a series of these unsymmetrical valleys. The principal large dip slopes are formed by the Shawangunk conglomerate and the Onondaga limestone. In each case an original stream had adjusted its course fully to the structure and was shifting slowly by the sapping process to the west against the opposing edges of the overlying strata which form the bordering escarpment. One of these unsymmetrical valleys lies along the easterly base of the Hamilton escarpment and is continuous with the lower course of Esopus creek farther to the north. In the area under special study it is not occupied by a stream now but is filled with glacial drift so completely that the original stream has been evicted. It is evident, however, from computations based upon the average dip of the slope carried to the base of the escarpment that the bed rock floor ought to be from 200 to 300 feet below the present surface in the deepest portion. Borings have proven this to be the case both along the present line near Kripplebush and also on the first trial line across the Esopus at Hurley. The same thing is true near High Falls in the center of the valley where Shawangunk conglomerate forms the dip slope and the escarpment is formed by the Helderberg limestones. In this case the drift filling is very deep also, and Rondout creek flows upon it quite independent of rock structure except where it has cut across the margin as at High Falls. In the eastern half of the valley the hard Shawangunk conglomerate forms the chief rock floor and largely controls the contour by its own foldings and other displacements. Thus the Coxing kill tributary valley lies in a syncline of the conglomerate with occasional remnants of overlying beds as outliers adding some variety to the form. The Shawangunk mountains, as a physiographic formations. On the west side, the foothills of the Catskills form a part of the cuesta developed by the erosion of Paleozoic sediments, the inface coinciding with the escarpment along the lower Esopus and Rondout valleys at this point. It is certain therefore that the drainage of the Rondout valley before the Ice age differed materially from the present lines. A stream, probably the original Rondout, followed near the western margin of the valley and joined the Esopus as it emerged from the Hamilton escarpment to turn northeast. Another which had cut somewhat deeper occupied the central portion of the valley and probably joined the Esopus at some point farther north — its lower course is not explored. 2 Where are the most critical places — those whose geologic characters are such as to demand exploration ? And at the same time which sections may be safely left without testing? 3 What is the rock structure and condition? And are. there reasons for believing that the tunnel plan is not feasible at this point. If so, where can a better one be found? From the fact that the present Rondout flows across solid ledges at High Falls and at Rosendale from ioo to 200 feet above the known rock floor of the preglacial gorge where explored it is clear that the present course is entirely different from the original. The Coxing kill, the third and most easterly of these streams is not so much disturbed although it also is shifted. It is worth noting that the streams of this valley together with the lower Esopus and the Wallkill river have become so completely adjusted to the rock structure that they all flow up the larger Hudson valley, of which all form a part, and join the master stream retrograde streams. Explorations. Systematic explorations and tests are represented chiefly by drill borings through drift into the rx>ck floor. These were supplemented by two test tunnels for working character of material and a series of tests on the behavior of certain of the drill holes, together with other tests on material. The results are embodied in the accompanying cross sections and the additional discussion of special features. Detail of local sections Kripplebush section. This from the first was regarded as one of the critical sections because of the buried gorge along the base of the Hamilton escarpment and because of the doubt as to the behavior of the Onondaga limestone. On the accompanying section the borings are plotted and the structure as now interpreted is indicated. The dip slope formed by the Onondaga limestone is covered by 200 to 250 feet of drift, mostly modified drift. The strong valley character of the rock floor is almost wholly obscured by the glacial deposits and the present brook, an insignificant stream compared to the preglacial one, occupies a position above the escarpment instead of above the old channel. After a couple of the central holes were finished, it became apparent that the structure is not nearly so simple at this point as the general surface features would lead one to expect. It was clear that a simple dip such as was proven to prevail on the dip slope would not account for the much greater depth attained by it in the vicinity of station 500. The discovery of this additional feature raised two questions: (1) Is the structure a flexure or is it a fault, and if a fault whether normal or thrust, and (2) what is the probable effect of this structure on the position and depth of the preglacial gorge ? The habit of the district immediately east of the valley would support the theory of a thrust fault. The nature of the immediate area would suggest a simple flexure while it is manifestly possible that a normal fault could easily occur. Later explorations1 have 1 Since the above was written the tunnel has been completed through the Kripplebush section. Although faulting is indicated by the borings and actual occurrence of the beds it is very difficult to find the fault. A part of the displacement is accomplished by the steepening of the dip but this will not account for more than half of it. The striking physiographic feature is the development and preservation of the escarpment on the downthrow side. This occurrence is certainly a very unusual case in that regard [see fig. 19]. Because of the intention to construct the tunnel deep enough in bed rock to reach safe rock conditions the question of depth of buried gorge becomes an important one. As soon as it was discovered that a fault existed there the problem became of sufficient prominence to demand more detailed exploration. If the faulting is accompanied by a broken zone in condition favorable to more ready erosion, it would be possible that the original stream in working down this dip slope might become entrenched in the fault zone and at that point begin to cut a narrow gorge instead of continuing the sapping process. In fact, it would undoubtedly do this very thing if there is such a crushed zone of any consequence and if the erosion process were allowed to continue long after reaching this critical point. As a matter of fact explorations have shown that there is a thin layer of Hamilton shales still remaining on the Onondaga and the deepest point found is on the Hamilton shales side. These facts in connection with the failure to find any deep notch indicate that there is probably no zone of much greater weakness than the shale member itself. It is reasonable to conclude that the rock floor can be safely regarded as not much lower than 88 feet A. T. and that the rock condition is not especially bad for tunnel construction1 even in the fault zone. Rondout creek section. This is the central portion of the valley including the depression occupied by the present Rondout and the exposed edges of the series of shales and Helderberg limestone. The repetition of the dip slope and escarpment, together with the heavy drift filling and the occurrence of so many formations together make this an important section. All formations from the Shawangunk conglomerate to the Port Ewen shaly limestone occur at this point, and although there is little outward evidence of disturbance it is certain that whatever difficulty is to be found in this variable series is likely to be met here. It is therefore a section that requires exploration both for depth of preglacial channel and for quality of rock. All of the formations dip westward wherever exposed, but the dips vary somewhat, nearly all being of low angle. Occasional minor inequalities of the nature of small rolls may be seen, as, for example, the small fold in the gorge at High Falls [see pi. 24]. Explorations have shown, as indicated on the accompanying cross section [fig. 20], that there is a deeper buried gorge here than at Kripplebush. The deepest point discovered is a few feet below tide level. The escarpment is steep and is formed by the Coeymans and New Scotland formations. The dip slope is Shawangunk conglomerate, High Falls shale and Binnewater sandstone, with the Manlius limestone forming the floor. Identification of the drill cores which penetrate the limestone indicate that the dip slope is reversed on the west side of the gorge and that the stream had really reached about the axis of the trough. A discrepancy in thicknesses and depths in hole no. 34 by which it appeared that the Coeymans formation was almost twice as thick as usual and that it contained a broken or crushed zone leads to the interpretation that there is a small thrust fault here which repeats the formation as shown on the accompanying cross section. Instead of a uniform westerly dip of all formations from the Rondout westward it is proven that minor anticlinal rolls and even thrust faults, as in this case, or such faults as in the Kripplebush case are not to be excluded. This structural relation has a direct bearing upon the question of the thickness of the Esopus shales. The Esopus is certainly not so thick as would otherwise be supposed, by 200 or 300 feet at the least. The true thickness is still an unknown quantity (estimated at 800 feet). It is clear that the aqueduct tunnel will have to be constructed a considerable depth below sea level at this section, probably not less than minus 150 feet,1 even if the character of the formations be neglected. But the character or quality of these formations in view of their structural relation constitutes the chief problem. Because of the fact that every structure reaches the surface and eventually dips gently to the west in such manner as to encourage water circulation, their water-carrying capacity or general porosity becomes of great importance. A great capacity is all the more serious because of the heavy drift cover within the abandoned gorge, on top of which the stream flows and which constitutes essentially an unlimited storage reservoir to feed underground circulation. This is all the mor-e true if crush zones are extensively developed as accompaniments of the faulting. In general as to perviousness the indications are somewhat obscure. But the data now obtained seem to prove that all the formations except the Binnewater sandstone and the High Falls shale are compact and fairly impervious along the bedding lines. Only where crevices have formed or where crushing occurs is there likely to be heavy circulation. This is all the more important since so many of the beds are limestones known to be readily soluble in circulating water. One of these limestones, the Manlius, exhibits occasional large open solution joints at the surface — so large that a surface stream disappears entirely at the so called " Pompey's cave " and joins the subterranean circulation. But such caves are probably limited to the surface. It is near this point, however, that one of the earlier borings at one side of the present line discovered very soft ground at a depth of about sea level, i. e. over 200 feet below the present surface, which shows that similar conditions prevail at certain points to great depth. Pumping tests made on hole no. 32 in an attempt to establish some data on the inflow of water gave very interesting results. These tests were very thorough. It was proven that the water was supplied in apparently inexhaustible quantity at maximum pumping capacity, which was ninety gallons per minute. Futhermore, the chief inflow seemed to be from the Binnewater and High Falls formations as was to be expected. Whether a crush zone allowing free circulation is furnishing a portion of this supply or whether the whole inflow represents the normal porosity condition of these formations is not yet proven.1 Other porosity tests have been made in such way as to locate and measure this factor [see later discussion]. Hole no. 10 shows an artesian overflow that comes from the Binnewater sandstone. A working shaft has been put down also in the vicinity of hole no. 32 and at the same depth found an enormous inflow of water which drowned out operations for a time. The lateral supply in this case has been reduced by introducing a thin cement grouting through holes bored in the surrounding rock from the surface. "shallow holes and the supply comes from near the contact between High Falls shale and Shawangunk conglomerate. / It is certain from these observations and tests therefore that the Binnewater sandstone and High Falls shale are more porous than the other formations, and because of the serious difficulties arising from so heavy inflow of water from them the tunnel grade should be shifted so as to avoid these formations as much as possible. A comparison of the accompanying cross section, which is drawn to scale [fig. 20J , will show that a tunnel on one level would necessarily run for a long distance in these beds because of the gentle syncline. Furthermore, they lie at about the depth that would otherwise be a safe depth below the buried gorge. But a tunnel with a step-down, i. e. one run at two different levels could avoid most of this poor ground. By approaching at a level of about — 50 feet or — 100 feet in the limestone beds to station 600 (hole no. 34), then stepping down to — 250 feet, the line in a very short distance crosses these two porous formations and enters the Shawangunk conglomerate which is more substantial, and, all things considered, one that seems most advantageous for successful construction. It will have to maintain a head of more than 700 feet as the difference between hydraulic grade and the tunnel level in this section. Under these conditions rock quality and condition are of greatest importance and there is no doubt about the advisability of avoiding the poorest formations in some such manner. Coxing kill section. On the line of exploration the Coxing kill flows over Shawangunk conglomerate and High Falls shale. Both dip plainly eastward, and a hole no. 1 1 located on the east side of the brook penetrates about 70 feet of drift and shale. But only a hundred feet to the east Shawangunk conglomerate outcrops at the surface dipping the same way. It is certain therefore that a fault occurs here. The dip of the fault plane is indeterminate from the surface, but the relations and surroundings indicate a fault of the thrust type. Later explorations indicate that the fault plane is rather flat [see cross section fig. 21] so that the shales are repeated above and below a tongue of conglomerate. Boring no. 1 1 has also an artesian flow of considerable volume coming from near the bottom of the conglomerate. It is a mineral water. The chief importance of this section as a problem in applied geology lies in the influence of the fault and the maximum depression of the conglomerate. If the tunnel, which enters Hudson River slates at the Rondout creek section at — 250 feet can be kept within that formation throughout the rest of its course, there is no doubt that an advantage will be gained both in the greater imperviousness of the rock and the greater case of penetration. Wherever the conglomerate is undisturbed it is perfectly good, but where broken the crevices are but imperfectly healed and circulation is unhindered. It would therefore be desirable to know whether at — 250 feet the whole of the downward wedge of Shawangunk could be avoided. The borings indicate a thickness of Shawangunk of 345 feet in hole no. 11 where it is cut at a small angle, and a thickness of 409 feet in hole no. 36 where it probably lies pretty flat. This greater thickness together with the finding of crushed rock at about the — 100 foot level leads to the conclusion that the formation is overthickened here by the thrust fault to the extent probably of about 75 feet. The true thickness of the formation at this point is doubtless more nearly 300 feet than either of the figures obtained directly from the two holes. If this interpretation is used as the basis of plotting a cross section [sec accompanying cross section] it is apparent that the conglomerate should not be expected to extend more than a few hundred feet east of hole no. 36 and it probably does not reach a much greater depth than the — 236 feet represented as its basein that boring.1 1 Construction of the tunnel has progressed far enough through this section to prove that the Shawangunk formation' does not reach much lower. It forms the roof of the tunnel for some considerable distance but does not come down into the tunnel more than a foot or two. Shawangunk overthrust. At the extreme eastern side of the Rondout valley near the point where the surface reaches hydraulic grade again, the surface outcrops pass from High Falls shale to Shawangunk conglomerate to Hudson River shale in the normal order but with entirely too small an area of conglomerate considering the character of the formations. The higher ground is all Hudson River in the vicinity, and there is abundant evidence of crushing and disturbance. It is evident that a thrust fault is again encountered here, one of sufficient throw to bring the Hudson River slates above the Shawangunk conglomerate — probably a lateral displacement of very great extent. Explorations have fully proven the existence of this fault. The accompanying diagram shows a cross section as now outlined by complete penetration of two borings. Two trial tunnels were run to test working quality of Hudson River slates compared to Shawangunk conglomerate at this locality. Both are within the influence of the fault zone. Both are therefore more broken than the normal with the result that the Hudson River slates probably show poorer condition than usual and more troublesome working, while Shawangunk conglomerate probably shows easier working than usual. It is believed that normally the two rocks would present a greater difference than was found in this test. Rondout valley. Caves. One of these is in regard to the possible existence of underground caverns. This was given a special prominence early in the work by the experience of one of the drills. After penetrating the limestone series near High Falls to a depth of over 200 feet, the drill seemed to leave the rock and enter a space allowing the rods to drop 28 feet before being arrested by solid material. The further attempt to work in this hole resulted in the breaking of the rod doAvn at this point and the subsequent failure to recover the diamond bit which is still in the bottom of the hole. The question is as to the meaning of this occurrence. Is it a cavern? " Pompey's cave " has been referred to in an earlier paragraph. This is clearly not much of a cave. It is essentially an enlarged joint or series of joints by solution along the bed of a surface stream to such extent that the stream normally at present has become subterranean. It is the writer's opinion that the case encountered by the drill boring is similar. The apparent cavern is probably a slightly enlarged joint along a line of somewhat abundant underground circulation and perhaps associated with some crush zone developed by the small faulting known to occur in this immediate vicinity. It is probably not entirely empty but contains residuary clay, and in all likelihood is very narrow and not exactly vertical, so that the drill rods were bent out of their normal course and wedged into the lower part of the crevice. Smaller spaces of this sort were encountered at a few other points.1 These occurrences seem to indicate that the limestone beds yield rather readily to solution by underground water, and that this circulation has been at one time active to at least 50 feet below present sea level. With present ground water level nearly 200 feet above sea level it is extremely unlikely that any such action is going on at so great depth. The occurrence is therefore strongly corroborative of former greater continental elevation when the deep stream gorges, now buried, were being made. These deeper caverns or solution joints probably date from that epoch. Imperviousness and insolubility. The question of imperviousness and closely associated with it that of solubility, is of great practical importance in this particular work. The immense pressure under which the tunnel will be placed in crossing this valley makes it impossible to construct a water-tight lining. Everywhere much depends upon the rock walls to help hold the water from sjeriotis iloss. Wherever the rock is fairly impervious except occasional crevices or joints they can be grouted and safeguarded satisfactorily. But where a formation is of general porosity this can not be so successfully done. Even more difficult to handle is the rock wall which is soluble and which therefore with enforced seepage may tend to become progressively more porous. That this consideration is not wholly theoretical is shown very forcibly by the Thirlmere aqueduct of the Manchester (England) Waterworks. In that case a 3 mile section was built through limestone country using the same local limestone for concrete aggregate. Although 1 In constructing the tunnel several clay-filled spaces have been discovered in the same vicinity at elevation — 100. One of these extended vertically with a width of 1 to 2 feet and from it a great mass of mud ran into the tunnel. At one point it was connected with a horizontal space of the same kind extending 15 feet. It can be seen that the original crevices have been enlarged by water and that they were originally formed during faulting. this concrete was mixed as rich as 1 part cement to 5 parts aggregate and the work was well done, excessive leakage reaching a total of 1,250,000 imperial gallons per day was developed within a year. It was found that the limestone fragments of the aggregate were corroded forming holes through the lining of the aqueduct and that these holes actually enlarged outward. All this was done under cut and cover conditions with not more than a 6 or 7 foot head on the bottom of the aqueduct. In the Rondout valley, the aqueduct will cut no less than 6 limestone beds in all cases under great pressure. This fact will in all probability tend to increase the action. But, of course, some of the beds may not yield so readily to solution. Tests made thus far, however, indicate that all are attacked in water. Considering these facts it seems desirable, so far as possible, to avoid the limestone beds wherever rock of greater resistance to solution can be reached, and further it is equally desirable to use a more resistant rock for the lining concrete. So long, however, as the formation is not very pervious so that a new circulation could not be established by the escaping water there would be little harmful effect. This is a limestone that in composition and structure at the Rondout valley is apparently not very different in quality from the Thirlmere rock. Analyses of the cement rock show less similarity but observations indicate that it is also attacked. ates are better quality of wall than the limestones. A very acute observation along this line by Dr Thomas C. Brown while employed on the staff of the Board of Water Supply is of special interest. In studying local conditions he noticed that the limestone blocks used in building the old Delaware and Hudson (D. & H.) canal showed the effect of contact with the water. The best place for measurable data seemed to be around the old locks where squared and evenly trimmed blocks had been used. These were, during the years of its use, from 1825 (approximately 35 to 40 years) subject to the action of water flowing or standing in direct contact. The coigns of the locks, which were without doubt freshly and well cut when laid, are now etched till the fossils and other cherty constituents stand out from one eighth to one half inch beyond the general block surface, and in some cases the pits are an inch deep. That this etching is due to the water rather than to exposure to weather is shown by the lack of such extensive action on blocks used in houses and exposed a much longer time. Blocks representing the Manlius and Coeymans were identified. But there is no reasonable doubt that others would be similarly affected. On some it would be less easily detected. On account of the disturbances another factor is introduced. Rocks which readily heal their fractures are likely to furnish better ground, i. e. more free from water circulation especially, than rocks more brittle and slow to heal. Therefore in this district the shales and slates such as the Hudson River series and the Esopus and Hamilton shales are the best ground, while the Binnewater sandstone is the poorest. Cross sections. Probably in no region of like extent is it possible to> construct a geologic cross section of so many complex features so accurately as can now be done of the Rondout valley along the aqueduct line. The section is known or can be computed to a total depth below the surface of 1000 feet, including 12 distinct formations, so closely that any bed or contact can be located within a few feet at any point throughout a total distance of over 4 miles. Rondout siphon statistics 1 Total borings on the siphon line. Three different boring equipments have been used owned by different parties and records have heen kept so that the work of each can be followed or compared with the others. On this division the Board of Water Supply owned and operated one machine with their own men, another equipment was owned and operated by C. H. McCarthy, while a third which finally did a majority of the work, belonged to Sprague & Henwood, Contractors, of Scranton, Pa. 2 Core recovery from various strata. So nearly as can be done the strata represented in the drill cores have been identified and summarized as to total penetration and core saving. The core saving is a factor of prime importance in judging of the quality of rock and its freedom from disturbance. The following items are gathered from a study of the whole series. a Holes 6, 10, 12, 13, 15, 17, 18, 21, 22 and 25 penetrate Helderberg limestone, a total combined depth of 1096 feet. Individual holes vary in core saving from 39.3;/ (no. 13) to 95.3$ (no. 15). The average core saving is 78.19$. c Holes 11, 19, 20, 23, 24, 27 penetrate Hudson River shale and together represent a total of 696.5 feet. The core saving varies from 16.6$ to 89^, with an average of 42.1$. d Holes 6, 10, 11, 12, 14, 16 and 20 cut High Falls shales to a combined total of 410 feet. The saving varies in different holes from 17$ to 83.3^, with an average core saving of 44.5$. / Holes 10, 11, 12, 14, 16, 19, 20, 23, 24 and 27 penetrate Shawangunk conglomerate a total of 1356.5 feet. Core saving varies in different holes from 33.3$ to 100$. The average recovery is 60.52^'. y Holes 6, 10, 12, 15 and 16 cut Binnewater sandstone. The total penetration is 205 feet. The range of core saving is from 30.6^ to 74.7^, with an average of 56$. 3 Artesian flows. Several of the borings struck artesian flow of water. The fact that the sources of this flow are not the same has led to a tabulation of these data. Pumping experiments and porosity tests Systematic tests have been made for flow of water, behavior of ground water and porosity of rock on certain of the Rondout exploratory holes under the direction of Mr L. White, division engineer. A summary of these tests has been furnished by him from which is quoted the following: In addition to determining the location and thickness of the beds and the general character and condition of the rock from inspection of the cores, serious attempts were made to determine the relative porosity and water-bearing quality of the rocks encountered for the following reasons. (1) To determine the probable leakage from the siphon when in operation. (2) To determine the probable amount of water to be handled in construction. These experiments were divided into three classes: (1) Observation of flow from cer- tain drill holes which showed sustained flow of water. (2) Pressure tests in which water was pumped into holes which had been sealed off and pressure and leakage noted. (3) Pumping tests in which water was pumped from 4 inch drill holes by means of deep well pump of the type used in oil wells, and fall of ground water during pumping and subsequent rise after cessation of pumping noted. A description of the first two and the results obtained from them follows : 7.5 feet The static head was observed by adding on lengths of pipe until the water ceased to flow over. It will be noticed in the case of hole no. 10 that the flow from the iJ/> inch pipe is not that due to static head of 18 feet, but that due to a head of only y2 foot. In other words the friction head is about 17.5 feet, and the velocity head only ^2 foot. This' same condition holds true of the other holes from which a flow was obtained. This would seem to indicate that the amount of water is not very great but that it is under considerable pressure. It is believed that this pressure is caused by gas. The flow from most of these holes has ceased since the pipe used in boring was withdrawn. There is still some flow from the following holes: 11/17, 20/17, 25/17 and 5/NE. The flow from hole 11/17 is constant at about 10 gallons per minute. The others are too small to be measured. It will be noted that the only substantial flows encountered were from the High Falls shale, Binnewater sandstone and Shawangunk grit, and that it was possible to force water into these rocks in greater quantities and at a less pressure than in the other shales and limestones. follows : Wash pipe ecmipped with a device for sealing the hole was lowered to the desired elevation. The seal consisted of alternate layers of rubber and wood around the pir>e preventing the water from escaping between the walls of the hole and the pipe. Water was then pumped in and pressure and leakage noted. The result of the pressure tests was to show in a general way: ( 1) That the pressure increased with the depth of seal. (2) Thai the leakage decreased with the depth of seal. (3) The maximum pressure in the grit was T40 pounds to the square inch and minimum Pumping experiments were carried on in holes 32/22 as follows: The apparatus used was a deep well pump of the type used in oil wells. The holes were of an inside diameter of 44 inches and were cased to the bottom. A 3/2 inch working barrel was then lowered to the bottom of a line of wooden sucker rods. The stroke was 44 inches and the nominal capacity of pump at 38 strokes per minute was 60 gallons per minute or 86,400 gallons per day. The power was obtained from a 40 horsepower boiler and 35 horsepower engine belted to a 10 foot band wheel which was connected to a 26 foot walking beam. In hole 32/22 at station 607 + 50 the average discharge at 38 strokes per minute was 90 gallons per minute or 129,600 per day. The experiment was continued for 15 days and the total amount of water pumped was 1,071,000 gallons. The ground water level was not lowered. It will be noticed that the discharge at this point was 50$ in excess of the theoretical capacity of the pump. This was caused by the presence of gas, the effect of which seemed to be increased by the churning action of the pump. This may also explain the failure to lower the ground water. and the bottom 274 feet a diameter of only 3^4 inches. At first a 2^4 inch working barrel was used to pump from the bottom and a discharge at 32 strokes per minute averaged 24 gallons per minute or 34,500 gallons per day. This was continued for about 15 days and the total quantity pumped was 490,000 gallons. The ground water level was lowered 17 feet at hole 34 and 4 feet at hole 32, 750 feet away. The 3/4 inch pump was then let down to a depth of 200 feet with a 2/2 inch casing reaching down to the Binnewater sandstone, depth of 437 feet. The average discharge at about 40 strokes per minute was 60-65 gallons per minute, or an average of 90,000 gallons per day. It will be noted that the discharge was much smaller than at hole 32 owing to the absence of gas. Pumping with a 3/4 inch pump was continued 16 days and 1,532,000 gallons of 34 during pumping water were pumped in addition to the 490,000 gallons from the 2^4 inch pump. The ground water level in hole 34 was lowered 36 feet in addition to the 17 feet by the 2 % inch pump, but rose 9 feet in 20 minutes, and 30.5 feet in the next five days. In the next 22 days it rose 9.15 feet, or .42 feet per day. rose 9.8 feet or at the rate of 0.45 feet per day. During construction1 shaft 4 located at same point as hole 32/22, station 607 + 50, has proved a very wet shaft, the inflow varying from 400 to 850 gallons per minute. Pumping at this shaft has lowered the general water level and correspondingly lowered the water level in hole 34/22 at station 600 + 00. Between the Rondout and Wallkill valleys the aqueduct is to follow a tunnel at hydraulic grade which so far as can be seen will cut only Shawangunk conglomerate and Hudson River slates. No doubt there are many complicated small structures which because of the nature of the slates can not be reconstructed. The work of tunneling is not advanced far enough to add anything. But in the Wallkill valley, where it is necessary again to plan a pressure tunnel several hundred feet below grade, a considerable amount of exploration has been carried on.1 These explorations [see sketch map fig. 8] are distributed along several lines crossing the valley at intervals between Springtown, about 3 miles north of New Paltz, and Libertyville, which is about an equal distance south. The geology is simple. Only Hudson River slates form the rock floor, and so far as can be judged no other formation is likely to be cut by the tunnels. There are no doubt many complicated structures, both folds and faults, as indicated by the high dips, but again because of the nature of this rock it is impossible to discriminate closely enough between different beds to determine exact relations. The point of greatest practical importance lies in the fact that the rock is fairly uniform and, although much disturbed is of such nature that crevices and joints or fault zones are almost as impervious as the undisturbed rock. This is because of the tendency of a formation of this composition to heal itself with fine, compact clay gouge. In fact, the mechanical disturbance produces or develops the cement filling contemporaneously with the movement. It is chiefly a mechanical filling, whereas the healing of a harder and more brittle rock like a granite or a limestone requires more chemical assistance. An additional practical question involves the estimate of depth required to avoid any possible buried Prepleistocene gorges and maintain a safe cover to guard against undue leakage or rupture. 1 Explorations on the Wallkill division are carried on under the direction of Lawrence C. Brink, division engineer. The final construction is in charge of James F. Sanborn, division engineer, with headquarters at New Paltz, N. Y. To this end most of the explorations were made. Two lines less than a mile apart on which a few exploratory borings were made near Springtown indicate two buried channels, a master channel and a tributary from the west which converge northward. A maximum depth reaching 70 feet below sea level was found on the more northerly line almost directly beneath the present stream channel which flows on drift at an elevation of 150 above tide. than 79 feet per mile. In the vicinity of Libertyville, 5 to 6 miles farther south, where the aqueduct was finally located, the profile was found to be con-, siderably higher. Intermediate profiles are shown in accompanying figures. The deepest point yet found on the Libertyville line is 65 feet above sea level. It is worth noting that the gradient of the ancient Wallkill is therefore shown to be decidedly unsymmetrical. The rock floor formation remains the same although it may vary somewhat in character. Under these circumstances, however, a gradient of 13 feet per mile from Libertyville to Springtown forms a sharp contrast with the 79 feet per mile represented at the Springtown locality. In view of the remarkable increase of gradient and the narrower form it seems reasonable to regard this as a rejuvenation feature developed at the time of extreme continental elevation. How much deeper the lower Wallkill may be, including the so called Rondout river, which is really a continuation of the ancient Wallkill and geologically belongs to this drainage line instead of to the Rondout, no one can tell. But it is at least interesting to observe that the intervening distance from Springtown to the Hudson at Kingston is approximately 12 miles and that a gradient for that distance equal to the average known in the 6 miles explored, i. e. 24 feet per mile, would depress the outlet 288 feet more. That would be equivalent to 367 feet below sea level. If, however, a steep gradient such as that at Springtown prevails in this lower portion it is necessarily much lower — for example if a 79 foot gradient is maintained it would be possible to reach a final outlet at — 1029 feet. It is likely that an intermediate value is more nearly correct. This has, however, an important bearing upon the question of maximum Hudson river depth, especially the existence of an inner deeper gorge above the Highlands. So far as this Wallkill profile goes, it supports the gorge theory. It is certain that the Prepleistocene Wallkill flowed north not very dif- WALLKILL SIPHON Profiles of the present and preglacial Wallkill channels near Libertyville, and a diagrammatic section showing the different types of drift-filling together with the borings which furnished the data ferently from the present stream except on a steeper gradient, but in all probability the headwater supplies between this stream and the Moodna have been somewhat shifted. It is possible that some former Moodna drainage area is now tributary to the Wallkill. But these changes were wholly glacial in origin and the extent of such shift is indeterminate at present. ploration in this valley was done successfully by the wash rig. The extensive lot of data was gathered without much delay or difficulty. This is because of the nature and origin of the drift cover. A considerable proportion of the drift mantle especially in central and deeper portion of the valley is modified assorted sands, gravels and silts or muds. In part they represent deposits in standing water laid down at a time when the lower (north) end of the valley was obstructed by ice and while waste was poured into the valley from neighboring ice fields. It is impossible to reconstruct the beds of these materials with any degree of accuracy. But it is at least certain that lens or wedgelike layers of different quality of material were penetrated, indicating oscillation and overlapping of deposition conditions, boulder beds and till being interlocked with assorted sands and gravels. But there is apparently no evidence of ice deposits of greatly differing age. The accompanying profile and cross section is a representation of materials on the Libertyville line based upon identifications made by the inspector of the Board of Water Supply of the Wallkill Division under Mr L. C. Brink, division engineer. ANCIENT MOODNA VALLEY Moodna creek enters the Hudson from the west between Cornwall and Newburgh not more than a mile north of the entrance to the Highlands. It is a retrograde stream in its backward flow similar to the Wallkill. But its channel at present is almost wholly on glacial drift which it has trenched to a depth of more than 100 feet below the average adjacent surface. How much of its retrograde course therefore may be postglacial is not so clear. It seems necessary, however, to account for all drainage on the north margin of the Highlands by streams flowing to the Hudson northward. There is no notch low enough for their escape elsewhere. The ancient Moodna must have carried most of this run-off from the district occupying the angle between the Wallkill and the Highlands. This stream ma}' have drained even more of the region now forming the divide with the Wallkill than does the present Moodna. In any case it must have been a stream of considerable size, capable of excavating a valley or gorge of greater prominence during the period of early Pleistocene rejuvenation than now appears. Furthermore its position makes it highly probable that tributaries of fair size entering in its lower course were also effective enough to require consideration. This conclusion has led to the exploration of the Moodna valley in considerable detail in preparation for the aqueduct work. The Catskill aqueduct is to cross the stream near Firth Cliffe, which lies almost directly west of Cornwall -an-Hudson, and because of the low surface elevation across this valley, as in the others, a pressure tunnel in rock is judged to be the most suitable type of structure. The accompanying sketch map shows the location. The region is one of chiefly Hudson River slate. But there are inliers of the older rocks such as Snake hill which belongs to a long ridge of Precambric gneiss and granite, brought to the surface by folding and faulting and there are more rarely outliers of younger formations such as Skunnemunk mountain. Farther north at Newburgh a gneiss ridge is accompanied by limestone, but in its soutberly extension the slates are in direct contact. This relation is believed to be wholly due to faulting on both limbs of the anticlines. This gneiss ridge disappears southward beneath the drift, but the borings have shown that it continues across the aqueduct line, although it has lost its influence on the topography.' There are other inliers of similar character such as Cronomer hill 3 miles northwest of Newburgh. Between these two gneiss ridges lies the southerly extension of the Wappinger limestone belt. But so far as is known it disappears beneath the Hudson River series long before reaching the line of exploration. Near Idlewild station, filling the space between the two branches of the Erie Railroad, there is a syncline containing the series of Siluric and Devonic strata which spreads southwestward to include Skunnemunk mountain, an outlier of Devonic strata. This is the only occurrence of these formations in this region south of the Rondout valley. The structure and stratigraphic features of this occurrence have been worked out by Hartnagel. Its northward extension in all probability terminates abruptly by a cross fault not far north of the Ontario and Western Railroad. slates. The Highland gneisses are bounded on the north side by a fault or series of faults. This brings various members of the overlying series into contact along the margin. In the best place where a direct observation can be made the gneisses are thrust over upon the Hudson River slates along a plane that dips about 40 degrees to the northeast. It is probable that a displacement of as much as 2000 feet or more could reasonably be assumed at this place. The contact zone also is much crushed and bears every evidence of having undergone extensive disturbance of this kind. Others of this same type occur within the gneisses where weaknesses formed in this way permit the development of such notches as Pagenstechers gorge. In some cases the rock beneath the surface in these zones is more decayed and less substantial than that at the surface. Exploration The first borings made with the wash rig were found extremely unreliable in the Moodna valley. That is because of the very heavy bouldery drift forming the greater part of the filling on the ancient topography. Next to the Hudson river gorge itself, no place has presented greater difficulties in penetrating this drift mantle. Boulders of such immense size occur that they have to be drilled like bed rock. In one of the holes a boulder 30 feet through was penetrated and 100 feet more of drift found below. Progress in such ground is extremely slow and costly. This is so much the more so where as in this case there are long stretches with unusually deep cover. A glance at the accompanying profile and cross section will show a very deep and wide valley. Many of the borings are more than 300 feet in drift which almost wholly obscures the ancient topography. The present Moodna is about half as deep and occupies the extreme eastern margin of the older gorge. There is a secondary gorge on the west separated from the main channel by a sharp divide. A few other smaller notches in the line represent smaller tributary or independent stream courses. One of these of much interest is known as Pagenstechers gorge. The rock floor at all points except two in the central Moodna valley including its two nearest tributaries is Hudson River shales, slates and sandstones of considerable variation, sometimes much brecciated. The two exceptional borings are no. 8/A44 and no. 16/A44 on the west flank of the westerly tributary gorge, and they are in pegmatite and granitic gneiss which is in all probability the narrow southerly extension of the Snake hill ridge. Here again neither quartzite nor limestone were found on the flank, a condition that seems to support the view of a double fault along the Snake hill ridge. In striking contrast with the broad central Moodna are the two narrow and very deep notches farther to the east, the first in slates and the second (Pagenstechers) in Highlands gneiss. example : The rock floor along the profile is almost flat for a distance of nearly half a mile in spite of the fact that there would seem to be every reason for a different form. The differences in hardness of rock floor alone would encourage differential erosion ; and, since the structure of the formations, the strike, is almost parallel to the supposed course of the stream, the influence of different beds would be at a maximum. Furthermore, the deep gorge of the Hudson, into which the stream flowed is only 2 miles away; and if that gorge represents stream erosion to such depth (over 750 feet) it would indicate a gradient of nearly 300 feet to the mile for the last 2 miles of the Moodna — a condition to say the least decidedly unfavorable to the development of a flat-bottomed valley. Of course, if the profile as determined can be assumed to run exactly parallel to the old stream channel for half a mile it would be less surprising. But even then it is too flat. For so short a distance from the Hudson gorge the gradient ought to be much greater than the variation observed in the Moodna channel. There are certainly reasons in the structural geology favoring a northeast course instead of one parallel to the profile line. And if the stream really did flow across this structure, the differences of hardness of beds ought to have encouraged a much greater difference in depth of channel than the profile presents. With structures all running northeast there is every reason to expect the stream to follow them. Recent exploratory data strongly supports the theory that the Hudson gorge at Storm King gap is widened and possibly somewhat overdeepened by glacial ice. Under normal stream relations one might consider the Moodna a tributary hanging valley, itself rounded and smoothed to a broad U-shape by ice. This would be a very easy solution if it were not for the fact that this tributary Moodna opens into the Hudson as a reversed stream, i. e. it opens against the flow of the Hudson and more or less directly against the known ice movement. It can not be a hanging valley therefore of the normal sort. If a hanging valley of ice origin at all it would necessarily be one therefore gouged out by ice moving from its mouth toward its head, a case that so far as the writer knows has never been observed. The chief objection to this theory is that in no other gorge or channel (with one exception, the Hudson at Storm King gap) anywhere in the region so far as known is there any evidence of serious modification of an original stream channel by the ice invasion. Of course, the axis of the valley is favorable and the situation is peculiar in that it parallels the Highlands front in this vicinity and the action of the ice may be assumed to have been somewhat concentrated along this margin because of the obstruction. Inner notch or secondary gorge. Those who habitually emphasize ice action would no doubt choose to regard this whole valley as shown in the profile, as chiefly glacial in character and origin. Tf that explanation is the true one, then it must be admitted that a deeper smaller inner notch or gorge is unnecessary and indeed unlikely. The critical point therefore in the whole argument is as to the origin of the Yalley, i. e. is it essentially a stream valley ? Or is it as to present rock floor form wholly a glacial valley ? . If it is a stream valley then no doubt full account must be taken of the proximity to the Hudson, and the possibility of developing a temporary graded condition and some adequate allowance must be made for its work during the subsequent continental elevation and the deepening of that river to several hundred feet below the known bottom of the Moodna. In short, one would expect a narrow deeper notch in the Moodna floor as a result of this rejuvenation. But on the contrary if in preglacial time the stream were not so powerful and had not been able to keep pace, and if the ice movement can be assumed to have concentrated along this line to such efficiency as to gouge out a groove 3000 feet wide almost flat to a depth of 300 feet only guided in direction by the original Moodna, then one may readily abandon the idea of a deeper notch. inner notch. In any attempt to choose between these factors, one is led -to reconstruct the preglacial drainage lines. When this is done it at once appears as most probable that there was at that time as now a considerable area tributary to the Hudson with a stream course very much like the present Moodna. In other words a fair sized stream is assured. Once such a stream is granted and the effects of its work reckoned in full knowledge of the adjacent Hudson, and its probable behavior is studied in the light of the data obtained in exploration of the valleys of other tributaries, it becomes more and more difficult to wholly eliminate the inner gorge idea. It seems to the writer probable that the valley owes its erosion chiefly to the preglacial stream. But the channel has suffered subsequent widening and smoothing by ice especially in its upper and broader portion, below which there may yet be a notch. One must admit that the results of boring prove the notch to he very narrow, less than 150 feet, or else not there at all. In reaching an opinion as to the possibility of one so narrow, it is worth while to note that the Esopus, which is a larger stream, has cut down at Cathedral gorge to a depth of from 50 to 80 feet with almost vertical sides and only about 150 feet wide. This gorge furthermore is cut in almost horizontal strata of such character that there is no special structural tendency in them to contract the stream. At the Moodna on the contrary, in addition to the smaller size of stream, the rocks stand on edge and run parallel to the supposed course so that this structural influence is toward a narrow and reasonably straight gorgelike form. It is not only possible that the gorge is narrow, but even probable that it is narrower than the present Moodna, i. e. less than 100 feet wide. How deep such an inner gorge may be if it does exist is a practical question in this particular case, because its depth has a direct influence on choice of depth of pressure tunnel. Because of the evident narrowness it is likely that it is not of very great depth — in view of the quality of these shales perhaps not over a hundred feet. Is there any one point more than another favorable for such a notch? There are two facts bearing on this question, (i) the variation in core saving which indicates that hole no. 5/A44 with 7<t has a recovery of only 1/5 the average, and (2) the fact that hole no. 15/A44-I- , which is the next hole, shows the lowest bed rock in this valley. On the ground of profile therefore and on the ground of structural weakness there is reason to choose this space between no. 5/A44 and no. 15/A44 as the most likely position. Summary. The very abnormal profile of the Moodna valley based upon the borings may be due either (1) to parallelism with the stream course, or (2) to a graded condition of the stream in some preglacial epoch, or (3) to modification of an original less prominent channel by ice erosion. It is the opinion of the writer that the ancient stream crossed the profile line much as the present stream does, that the additional narrower valley immediately to the west side is that of a preglacial tributary instead of a bend of the Moodna itself, that there was a development of a moderate sized somewhat flattened valley corresponding to the benches and shelves noted in other streams, including the Hudson, that subsequent elevation of the continent rejuvenated the stream which cut a deeper narrow inner notch, that glacial ice moving in reverse direction widened and smoothed this upper portion of the valley, but that there may yet be a remnant ot the deeper notch in its bottom, and that the space between holes no. 5/A44 and no. 15/A44 is the most likely location of this inner gc rge. Tributary divide. The sharp divide between the two deep portions of the valley bottom has proven an evasive feature in the later exploration. Two holes put down a short distance to the southward (24/A44 and 20/A44) failed to find the rock floor so high, one reaching rock at a depth of 181 feet and the other failing to find rock even at 213 feet. Two others nearly a thousand feet to the westward, however, found rock again at approximately the same elevation as the divide. If this is a tributary stream divide therefore it must have an east-west trend. Pagenstechers gorge This is a notch between Storm King ridge and Little Round top occupied by a very small mountain stream. The rock floor is granite gneiss of the Storm King type. Its special characters are (1) extreme shattering or crushed condition, and (2) extensive decay along this zone which has softened the rock constituents to great depth. Considering the nature of the granite gneiss in general this narrow gorge is a surprisingly deep one. But this is no doubt due to the influence of the decayed crush zone. The drill cores taken from the holes that penetrated the floor at this place are so much altered that, after several months exposure to the air, they can be readily crushed in the hand. Hole no. 16/A45 which is centrally located penetrated to — 196 feet. It is in material of this same condition, to at least — 100 feet. Similar conditions are proven to the north of the line, shown in the accompanying profile and a rapid increase in depths. From the surface outcrops farther up the gulch it is easy to see that the crushed zone extends in that direction with the strongest lines about s. 70 w. This is doubtless on the strike of the fault lines of the northern border of the range. It is of more than usual interest in showing the depth to which incipient decay has penetrated in these crush zones, and the efficiency of stream erosion along them. Overthrust fault The principal fault line follows the margin of the granite gneisses. At the best exposure of it the Hudson River slates are overridden by the gneiss. This represents therefore the cutting out entirely of the Wappinger limestone and the Poughquag quartzite and a part of the slates by the displacement which must amount to at least 2000 feet and probably more. The same relation is indicated by the borings and by the outcrop near the village of Cornwall, but a little limestone is found midway between the two points along the strike of the fault. The strike of the fault averages about n. 650 to 70° e., but locally, at the best exposure, it is only n. 350 e. The dip is southeast at an angle of approximately 45 degrees. 1 In cases which show no recovery of core a method of drilling was employed different from the others and the rock was ground to pieces. Failure to recover core may therefore be no indication of poor rock quality. ROCK CONDITION AT FOUNDRY BROOK 1 Foundry brook is a small stream entering the Hudson at Cold Spring in the Highlands. It drains a rather abnormally large valley bordering Bull mountain, and Breakneck ridge on the east, and its axis is in the strike of the principal structure of the gneisses which form the chief rock formation of the floor. This valley is in exact line with the course of the Hudson from West Point immediately southward, and its rock formations are similar in character and condition. There is greater variety of rock composition in this belt, i. e. the Foundry Brook-Hudson river belt, than in any other in the Highlands of similar area. The eastern half of the belt is a typical development of banded gneisses and schists and quartzites belonging to the sedimentary representatives of the Highlands gneiss. Small layers of interbedded limestones are frequent together with serpentine, and mica and graphite and quartz schists. In addition along the east bank of the Hudson, they are profoundly modified by crushing and shearing in zones that trend with the formation, i. e. in a direction leading toward and through Foundry brook valley. The west side is much less variable and is bounded at the margin by one of the most massive types of the region — the Bull mountain and Breakneck mountain gneissoid granites, which are essentially the same as that of Storm King mountain. But additional structures enter Foundry brook valley from the western side at an acute angle with its axis and formational trend. These additional structures are two well marked faults, which cross the Hudson — one along the precipitous southeast face of Crows Nest and the other along the southeast face of Storm King mountain. These are the most pronounced escarpments of the whole region. The first one crosses the Hudson between Cold Spring and Bull mountain and in passing northeastward loses much of its influence upon topography and its movement is probably dissipated in that direction. A line from the southeastern face of Crows Nest to the point to be described runs n. 500 e. 1 Explorations at Foundry brook were clone under the direction of Mr William E. Swift, division engineer, now in charge of the Hudson River division of the Northern aqueduct. Foundry brook therefore contains structures that could produce considerable effect upon the quality and condition of rock floor. The rock floor is covered with heavy bouldery drift — thicker on the Bull mountain flank than in the valley bottom proper. Where the aqueduct line crosses the floor is at an elevation of 200 feet to 350 feet A. T. Hydraulic grade of the aqueduct is about 400 feet. The lowest bed rock found along the line is 182.3 feet and the channel of the present stream coincides with the preglacial one in that portion of its course. There are two secondary channels — probably tributary stream channels on the west side. One of these lies under 70-80 feet of drift. Borings were made for the purpose of determining the rock floor profile and the condition of bed rock. In most of them the ordinary gneisses and granites were penetrated in normal condition. But in a few a very unusual condition was found. Hole no. 2 at el. 347 feet near the west or Bull mountain margin penetrated 49 feet of drift to el. 298. Then the drill passed into gneiss which was at the top, the first 30 feet, of a fair quality. This is shown by the core recovered — the first 12 feet -recovering over 50^. But the percentage of recovery rapidly fell off — amounting to only 36$ in the first 50 feet. Only 1 foot of core was recovered in the next 30 feet, or only 3^. While from that point el. 220 feet to the bottom of the hole el. 51.8, at a depth of 295.7 feet from the surface, nothing but fine decomposed matter was washed up. There was no core at all. This was at first reported as sand by the drillmen, and, coming at a time when exploration of deep buried gorges was the rule at other points of the aqueduct, there were many questions about the interpretation of this new hole, the first assumption of the drillers being that an overhanging ledge of a very deep gorge had been penetrated passing through it into river sands below. A little study of the material proved that this view is untenable. The sandy wash from the drill is true disintegrated gneiss much decayed and dislodged by the drill. Interpretation and further explorations It is certain that the soft material and the " sand " reported from this boring represent rock decay induced by underground water circulation. Water circulation is rather free as is shown by the fact that there was an artesian flow from this hole of 10 gallons per minute after reaching a depth of 80 feet, which increased to 15 gallons per minute after reaching a depth of 253 feet. This underground supply is maintained since completion and the pressure is sufficient to raise the water about 15 feet above the surface. This is a behavior that is consistent with the geologic conditions. The boring has no doubt penetrated a crush zone following one of the faults which enters this side of the valley. The crush zone dips steeply and the boring has penetrated the hanging wall of more solid rock in the first 50 feet and, after reaching the broken and decayed portion of the zone, has swung off parallel to the dip and avoiding the more resistant foot wall has followed down on the soft inner streak. Fi° 30 Sketch illustrating the interpretation of geologic structure across Foundry brook valley indicating the relation of certain borings to them and their supposed influence in deflecting the drills ^^ttiimt^J 1 This crush zone extends on northeastward across higher ground where opportunity for taking in surface water is offered. This is without doubt the source of supply for the circulation which furnishes the artesian flow and which has been so effective in producing decay to great depth. But the circulation and associated decay are probably limited to comparatively narrow zones. There is no good reason for assuming large masses of rotten gneiss at great depth. The worst zones are narrow but may be comparatively deep, i. e. they may extend much deeper than any of the borings yet made in this valley. The depth of decay is related to the outlet for underground circulation which in this case is the gorge of the Hudson. Several other boring's encountered similar conditions, especially those on the west flank of the valley within range of the belt in which the fault seems to be located. Hole no. 9 reached the rock floor at a depth of 80 feet, and then penetrated rock to a depth of 159.7 feet. All of the material is badly decayed. Only 1 foot of core was recovered from the whole boring and that is mostly quartz coming from a veinlet or pegmatitic streak at 141 feet. Water under slight pressure was encountered in this hole also. But because of the somewhat greater elevation of the surface at this than at hole no. 2 there is not a constant outflow. Two other holes immediately to the west show much better rock condition — no. 1 showing 79$ core recovery. Also two on the east side at greater distance [see accompanying profile] show good rock. But one other no. 3 at a distance of over a thousand feet to the east encountered another zone of decayed rock, the record being very similar to no. 2 in that poorer conditions are shown at depth than near the surface. Rock was found at a depth of 20.2 feet. From 20.2 to 116 feet the gneiss was quite hard, 55.3 feet of core being recovered or S7-7/'- But from 116 feet to the bottom 207.5 feet the material was as bad as in hole no. 2, and no core was recovered. Several other tests were made on the borings with a view to determining the character and extent of these features more definitely. For example, if the interpretation given for the behavior of no. 2 and no. 3 is correct it ought to be possible to survey the holes and determine a deflection from the vertical as the drill deviated from its course to follow the softest streak. A survey conducted for this purpose indicates just such a result. The accompanying sketch shows the data plotted. The drill was deflected 40 36' at a depth of 50 feet, 70 36' at 100 feet, 8° 2' at 150 feet and 90 40' at 198 feet. sound rock. Some of these data are given on the profile. Some of the rock of this valley, if very extensive, such as that in borings no. 2, no. 3 and no. 9, would be very poor ground for tunneling. The practical question involves especially the width of these zones, are they a foot wide or are they a hundred ? In an attempt to help settle that question an inclined hole was proposed that was to run at an angle low enough to crosscut these belts. Accordingly hole no. T4 was bored inclined 400 26' to the horizontal and started on the solid gcanite gneiss. The results were not very encouraging. The decay is shown not to be confined to mere seams. The doubt raised by so much bad ground has finally led to the adoption of a different plan for crossing Foundry brook valley and no further data are likely to be added by this work. As it now stands the borings at Foundry brook indicate the deepest decay of any yet made in granites or gneisses except those of Pagenstechers gorge on the north side of Storm King mountain. Both cases are of similar origin and history, but Foundry brook is apparently the more complex in occurrence. There are several parallel zones along which there is extensive decay to a depth of more than 300 fc-et. GEOLOGY OF SPROUT BROOK Three creeks unite to form an inlet at the sharp bend in the Hudson immediately above Peekskill. The middle one of these is known as Sprout brook. It occupies a deep and narrow valley that is well marked for 10 miles in its lower course and is traceable as a physiographic feature of less prominence to the north margin of the Highlands. Its persistence indicates some important structural control in erosion. This valley lies in the midst of the most typical gneisses and granites of the Highlands region. And in addition several of the " iron mines " of Putnam county lie on its western flank. The rocks are complex granitic and quartzose gneisses and granites. Foliation and banding and bedding wherever this appears is parallel to the axis of the valley. The most notable geologic feature is the occurrence of a broad belt of crystalline limestone throughout the lower 4 miles. It is undoubtedly chiefly this limestone, which is less resistant to weather than the gneisses, that controls the form and size of the valley. As to geologic relations, this is one of the most interesting formations of the region. It is coarsely crystalline, full of silicious impurities at many places and carries small igneous injections and dykes, and so far as the bedding can be followed, stands almost on edge. Although an actual contact is not seen, at several places the limestone and gneiss approach within a few feet of each other and it is certain that no other formation can come between them. This is more certainly indicated in the northerly extension of the valley where the limestone gradually disappears leaving only the gneisses and granites. That there may be a fault contact must be admitted, but of this there is no good evidence in the field. Such relations and character show that this limestone is similar to the smaller interbedded occurrences noted frequently with the gneisses in the Highlands and elsewhere. If it is of that type then it is the largest representative yet found in that series. But it is also in these characters similar to the Inwood limestone of more southerly areas. The overlying Manhattan schist which is lacking may have been removed in erosion. One of these types it resembles, but it can not be the Wappinger (Cambro-Ordovicic) as was pointed out by the writer in a former report.1 The Wappinger, wherever known to be such, is never intruded and always lies above a thick quartzite (Poughquag). It does so even in the next valley (Peekskill creek) less than a mile distant. With the interpretation of this Sprout Brook limestone therefore is involved the correlation and interpretation of the age of much greater areas. That the Sprout Brook limestone is not Wappinger is clear enough, but it could be either interbedded (Grenville) or Inwood. If it is Grenville then of course it has no direct bearing on the WappingerInwood question and these two might be equivalents. But if the Sprout Brook limestone is not Grenville (interbedded) then it must be Inwood and in that case the Inwood and Wappinger are not equivalent — which means that there are two series above the gneisses instead of one — an Inwood-Manhattan series, and a Poughquag- Wappinger-Hudson River series. At the present time it is not possible to give with certainty a final interpretation of the Sprout Brook limestone. It was at first believed that a pressure tunnel could be constructed advantageously at the point of crossing this valley and borings were made to test rock conditions. The data gathered in exploration are indicated on the accompanying geologic cross section [fig. 32]. Borings indicate that the rock floor has been eroded to a few feet below present sea level and that the gorge has a drift filling of more than 150 feet. The central borings penetrate limestone and indicate a total width of this type of more than 400 and less than 600 feet. The best estimate on the basis of these explorations is 500 feet. Whether this width represents one thickness of the formation as would probably be the case if it is an interbedded Grenville layer, or part of a double thickness due to infolding, as would probably be the case if it is the Inwood, there is no evidence. The thickness seems to be even greater farther south in the same valley (it becomes )A mile wide), but it can not be accurately measured and there is no way of guarding against repetition of folds. The valley floor is decidedly terraced at an elevation of about 130 A.T. One side is limestone and the other is granitic rock. This is probably a local mark of the Tertiary base leveling work. Because of the great depth of this narrow gorge, it would require a 500 foot shaft at each side to lead from hydraulic grade down to a safe level for the pressure tunnel. For a crossing not more than 2000 feet long this is excessive and the cost becomes greater than by other methods of construction. Consequently the tunnel plan has been abandoned and it is not likely that further data bearing upon these questions will be added. STRUCTURE OF PEEKSKILL CREEK VALLEY Immediately east of Sprout brook, described in the previous section, is Peekskill creek, which drains the largest valley emerging from the southern margin of the Highlands. This valley as a physiographic feature is continuous with the Hudson river gorge from the sharp bend at Peekskill to Tompkins Cove. There are important structural features along the strike of this valley which extend very far beyond the limits of Peekskill creek itself, among which are strong folding and block faulting. The chief fault continues to the southwest with still greater prominence and appears on the west side of the Hudson in the escarpment forming the southeastern margin of the Highlands continuously for many miles into New Jersey. Near the Hudson, Peekskill creek and Sprout brook unite and the structures and formations characteristic of each valley converge until in the last half mile of their united course rock formations characteristic of Sprout brook lie on one side of the valley, those characteristic of Peekskill creek on the other, and the contact which follows the divide to that point then passes beneath the waters of Peekskill inlet. Because of the block faulting which has carried down overlying formations and protected them from the total destruction characteristic of the central Highlands region this valley is of unusual interest. The aqueduct line crosses this valley about 3 miles from the Hudson, and in determining the possibility of crossing by pressure tunnel in rock a considerable number of explorations were made. nitely and to determine the condition of the formations. An examination of the drill cores and records of explorations shows the following facts which are compiled as fully as possible on the accompanying cross section. belongs to the Hudson River slate series. This type of rock forms the whole western side of the valley for several miles. Beds stand on edge or dip steeply southeastward and are in good sound physical condition. The rock is everywhere a fine grained micaceous slate or phyllite and in some places carries pyrite crystals. It is impossible to estimate the thickness or minor structural habits. But it is clear that it forms the upper member of a series that has a synclinal structure and therefore the belt represented by the phyllite marks the axis of the syncline although the chief valley development lies wholly to one side. Limestone. Eleven borings (no. 2, 3D, 4 C, 11, 13 C. 18, 22, 23, 25, 26 and 29; are in limestone. All show essentially a very fine grained close textured crystalline gray or white or bluish rock with strong bedding standing nearly vertical or at very high angles. This, because of its character and relation to other formations, is regarded as the Wappinger limestone — a formation well known north of the Highlands, where it is at least 1000 feet thick. From present explorations it is now certain that a belt 3250 feet wide is underlain continuously by this formation standing nearly on edge. Unless repeated of course this would represent approximately the thickness for Peekskill valley. But it is not believed to be so thick. It is more likely that there is a threefold occurrence brought about by close isoclinal folding (a closed s-fold) as seen in the accompanying cross section. This view is supported by at least one occurrence of the underlying quartzite member near the center of the valley at a point a couple of miles farther north On the line of exploration, however, none of the borings penetrate any other formation beneath. Attention is called to additional structural details and physical conditions in a later paragraph. Quartzite. One boring (no. 5) is in a quartzite. It i-~ very pure, fine grained, closely bound and typical quartzite. The beds stand almost vertical aud the whole thickness is known from nearby outcrops to be approximately 600 feet. From its character and relations to other formations it is regarded as the Poughquag — a well known formation of the north side of the Flighlands. Gneisses. Five borings (no. 7 K, 9 B, 17, 27 and 28) are in gneisses. These are to a considerable extent simple granite gneisses of igneous origin. But there is the usual variety characteristic of the Highlands gneisses and no doubt they are representatives of the great basal gneiss series that is elsewhere referred to as the equivalent of the Fordham of New York city. This is therefore the rock series of Peekskill creek. It is the only locality on the south side of the Highlands where all are represented in complete and simple form. There is no doubt that it is the Poughquag-Wappinger-IIudson River series, in spite of the complete absence of organic evidence. A similar though not so complete and clear occurrence is to be found on the west side of the Hudson near Stony Point and Tompkins Cove. That is a part of the same structural syncline. It is probable also that the phyllite so finely developed in the village of Peekskill in the next small valley to the east is the same. But outside of these occurrences there are none that clearly represent this same series as a whole and in the same condition. No more striking example of this fact can be found than the adjacent Sprout brook described in an earlier section. There coarse crystalline and injected and impure limestone occurs alone — no phyllite and no quartzite. When one remembers that the two occurrences so strongly contrasted. Sprout brook and Peekskill creek, converge until they actually unite, and still preserve their stratigraphic dissimilarity, without any adequate structural reason for it, the only conclusion possible is that the two occurrences represent two entirely different series of formations. The Peekskill valley series is Cambro-Ordovicic in age ; what is the other? It is older, at least that is certain. But is it (the Sprout Brook limestone) as old as the oldest of the gneisses themselves and therefore interbedded with them representing locally the Grenville ; or is it intermediate — Postgrenville and Precambric — with which possibly other occurrences of rocks of similar habit and equally uncertain relations belong? It is on the general similarity of this occurrence to the Inwood limestone as known throughout Westchester comity and New York city that a tentative intermediate series has been recognized. This is the Inwood-Manhattan series. Whether it is in reality a separate older series is not regarded as proven. But for engineering and practical purposes the distinction is a good one and eminently serviceable. Further, discussion may better be continued in a different publication. 3 Rock surface The bed rock surface is pretty well outlined by the borings. A profile based upon them seems to leave no unexplored space of sufficient extent to admit a gorge of great consequence to a lower level than is already shown in holes no. I and no. n [see profile and cross section, fig. 33]. The elevation indicated by no. 3 D is believed to be misleading because of the use of a drill that was capable of destroying a part of the ledge rock that would usually core. The points believed to be weakened by structural disturbance and therefore most likely to be attended by erosion and stream action are in the vicinity of hole no. 11, near the present creek, and hole no. 25, near Peekskill Hollow road. 4 Buried channels From the accompanying cross section it will be seen that the drift cover is more than 100 feet thick over large portions of Peeks•kill valley. The rock floor in the middle of the valley averages approximately 25 feet A.T., while the drift surface except where cut out by stream erosion is at about 125 feet. In the rock floor there are two depressions, the large one wholly within the limestone belt and the smaller following the limestone-phyllite contact. There is not much difference in their depth so far as explored, but there is a possibility of a somewhat deeper notch in each one. The depth to which some of the limestone beds are decayed by underground circulation would lead to the belief that a deeper notch may exist. The drift cover is chiefly partially assorted sands and gravels in the central portion of the valley, and more of a till on the eastern valley side. It is noteworthy that the present Peekskill creek lies far to one side following closely the phyllite wall. 5 Underground water Present elevation above sea level is so slight that there is apparently little encouragement of deep underground circulation. But ar certain points the rock has been found to be very badly decayed to a great depth — to at least 200 feet below sea level. This is believed to have been accomplished chiefly at a time when the region stood at a higher level. Hole no. 22 is especially notable in this connection. A comparison of the figures of core saving is one of the best lines of evidence on this question. Wherever data are at hand the percentages of saving have been put on the cross section. Hole no. 29, for example, shows a saving of only n<£ in the lower 250 feet, reaching a depth of 297 feet below sea level. rock forming essentially a great reservoir of supply that has ready access to the almost vertical limestone beds. This will give a maximum water supply to holes that penetrate porous or broken portions of bed rock. The attitude of all strata is especially favorable for admitting an almost inexhaustible supply from a considerable drift-covered area within which circulation is probably very rapid. All strata of this valley stand so nearly on edge that drills actually explore a very limited portion of the whole series of beds. No very great advantage is gained by excessively deep boring because the drill follows necessarily almost the same bed from top to bottom. At best only the immediately adjacent beds are penetrated. This means that much of the total thickness of beds is untouched by present explorations, and must be interpreted on the basis of their general likeness to those more fully determined. The usual succession of beds is known to be quite uniform in quality and locations where they can be studied and there is no reason to expect greater variation here. Deviations from such normal or uniform conditions are mostly due (a) to local development of mica from recrystallization of impurities in the limestone, and (b) to crush zones developed in the process of folding and faulting which has broken the rock or weakened it enough to permit a more ready circulation of underground water. Wherever either of these structural conditions prevail, the rock has been excessively decayed, or disintegrated, or sufficiently weakened in its binding matter or its sutures to crumble in the hand or break down to a sand under ordinary boring manipulation. This condition is known to reach to -297 feet. How much deeper is not known. Probably the decay dates back in large part to preglacial continental elevation at which time probably there was more ready deep circulation with possible outlet in the Hudson gorge. This action has been all the more effective by reason of the attitude of the beds. They stand so nearly on edge that they present all their weaknesses of bedding and sedimentation structures to the destructive surface agents. They admit surface water readily and favor abundant underground circulation. Considerable faulting occurs. The contact between the granitegneiss and quartzite is a fault contact. Wherever seen this is sound. But a crush zone in limestone lies nearly central in the valley, cut by holes no. 23 and no. 25, where the rock shows a finely brecciated In one hole, no. ri, near the phyilite-limestone contact, a soft, sandy condition was encountered at a depth of 133 feet, permitting the drill rods to be pushed down without boring at all, 60 feet ahead of the casing. This, however, is not believed to indicate any very extensive weakness. It is probably connected with the bedding planes or joints rather than with general decay or faulting. Four or five inches of solution and disintegration along bedding planes would account for all that has been proven. The fact that the rods could be shoved down 60 feet while the corresponding outer casing could be shoved down only half as far seems to support this view. If a tunnel were made across this valley there would be approximately 1 100 feet of it in Hudson River slate (phyllitc), 3250 feet in Wappinger limestone. 600 feet in Poughquag quartzite, and the rest in the gneisses. Some weak rock is certain to be found, especially in the vicinity of station 367+50 and 345+00 to 350-00. At both places increased water inflow would be encountered with almost exhaustless supply from the sands that lie on the rock floor above. At about this stage in the exploration the Board of Water Supply decided to abandon the rock tunnel plan. The conditions found were considered by them too questionable. Steel pipe construction is to be substituted. As a result it is not likely that much more detail will be added to the structure of this very complex valley. CROTON LAKE CROSSING It is proposed to finish Ashokan reservoir and the Northern aqueduct first. This so called Northern aqueduct reaches from the Catskills to Croton lake. Croton lake is the present supply of New York city and is already connected by two aqueducts with the city distribution. As a first step, therefore, and as an emergency measure the Catskill water will be delivered to the Croton system by finishing the Northern aqueduct first. As rapidly, however, as the whole project can be carried out the so called Southern aqueduct will be constructed to continue the Catskill water independently of the Croton supply to the city. The Southern aqueduct department has charge of the line from Hunters brook on the north side of Croton lake to Hill View reservoir near the New York city boundary. During exploratory work it has been under the direction of Major Merritt H. Smith, department engineer, with headquarters at White Plains. Construction now going on is in charge of Mr F. E. Winsor, department engineer. The first link in this southerly extension is to be a tunnel beneath Croton lake through which the Catskill water may pass in the same manner as it crosses other valleys. This crossing has been located a short distance below the old dam on the Croton, about 5 miles up stream from the Hudson. The problems involved at this point include ( 1 ) a determination of the kinds and quality of rock to be penetrated, (2) their watercarrying capacity, and (3) opinion as to the proper depth for a successful tunnel. The Croton valley is one of the very few in southeastern New York that actually crosses the geological formations and major structural features instead of following parallel to them. In its lower portion it passes from gneiss to limestone and to schist several times. The reason for this somewhat abnormal course is probably the development of weak zones by fault movements in this transverse direction. Only one of the well known formations of rock is exposed in the immediate vicinity of the tunnel site. This is the Manhattan schist, the uppermost formation of the region south of the Highlands. Along the Croton it varies greatly, the chief type being a garnet-bearing quartz-mica sohist varying from rather fine grain and semigrannlar appearance to a very coarse and strongly foliated structure. This part of the formation undoubtedly represents recrystallized or metamorphosed sediments. But associated with this fades there is a more dense black hornblende schist that, not only here but at many other places, is thought to represent igneous intrusions that have been metamorphosed together with sediments of various types, until both have lost almost all of their original characters. The hornblendic schist type is not so extensive as the other, the mica schist, but it is more compact and here as usual is in the better condition. Pegmatite stringers occur abundantly, especially in the mica schist varieties. They are of no great consequence, however, as a factor in this study. They originate! in the aqueo-igneous activity involved in the reerystallization of the rock when it was worked over into a schist. Beneath this Manhattan schist formation lies the Inzvood limestone, a bed probably at least 70c feet thick. But at this point how deep it lies and at what depth it would be penetrated nobody can tell. None of the drills have touched it. Beneath the limestone in turn lies the granitic and banded gneisses belonging to the Fordham gneiss series, the lowest and oldest of the region. Along the Croton river nothing but Manhattan schist is to be seen at the surface for more than a mile above and below the proposed crossing. The same thing is true for an equal distance on opposite sides from the river at this locality. But the structure is folded and the normal northeast-southwest trend of the folds crosses the river, every arch or anticline tending to bring the limestone and gneiss nearer to the surface. One of these folds does expose the limestone and gneiss in a strip extending from the Hudson river northeastward for two thirds of the distance to the old Croton dam. But before reaching the Croton valley this fold pitches down toward the northeast beneath the Manhattan schist and passes under the present lake (or reservoir) in diat relation, nut reaching the Mirface again Eor a distance of about 6 miles. At least one more fold is known to behave in a similar manner as it reaches the Croton. These facts make il certain that there is limestone beneath the schist in the vicinity of the crossing, and that it comes nearer to the surface in that vicinity than at some other places. ning nearly east and west. It is believed that similar movements have affected the rock in the Croton valley itself, modifying its condition so much as to control the course of the stream. The only immediate bearing upon the problem of the Croton crossing is the question that it raises about the quality of rock and the necessity that is introduced of trying to determine whether or not there is shattering enough to be very objectionable. Explorations and data Six drill holes have been made on this proposed Croton lake crossing — one on either side just at the margin and four others within the intermediate space of 1400 feet. These inner four have been made from rafts floated on the lake and have penetrated water, drift cover, and rock [see accompanying profile and cross section, pi. 27]. Rock floor. The depth of the preglacial Croton valley is pretty accurately determined at o feet or sea level. There is no reason to expect a gorge or inner channel of any consequence. The drills have penetrated only one formation, i. e. Manhattan schist. These test holes are believed to be near enough together to eliminate the possibility of any other formation appearing at tunnel grade. Rock condition. The two varieties of schist (1) the coarse garnetiferous quartz-mica rock, which is a metamorphosed former sediment, and (2) the darker, close grained hornblendic rock that is believed to represent an igneous intrusion, both occur in the cores brought up by the drill. Either under normal conditions is a good rock. But there are considerable differences in the physical condition of the rock. Holes no. 3 and no. 4 at the two extremes, on the lake borders, show sound rock that comes up in large cores with very high percentage recovery. This is confidently believed to represent the average condition of the rock in this vicinity at the sides of the valley. The central holes, however, nos. 1, 2, 5 and 15, all show more broken ground. Of these holes no. 2 is much the most broken, the core recovery being only 14.8^. The pieces are small and many are smoothed (slickensided) by movement. The hole penetrates a typical crush zone resulting from slight faulting movements, and the low saving is due to the fact that the incipient fractures are not well bound together (rehealed) by later mineral change. They are probably connected with the latest movements of this kind. The commonest secondary mineral now filling these crevices is chlorite, and, although it may completely fill the crevices it has little binding strength. Any new disturbance or strain readily causes separation along the same original lines. But in spite of the fact that the core is broken into small pieces and shows so low percentage of recovery it is quite certain that the rock itself is not badly decayed. An examination of one of the most doubtful looking cores from the lower part of hole no. x showed under the microscope little evidence of serious decay. This is believed to mean that underground water circulation is not as abundant as the fractured condition of the rock would lead one to expect. Furthermore, an examination of the cores in greater detail shows beyond question that much of the fracturing is entirely fresh and must have been done by the drill itself. It is certain that the low percentage of recovery is in part due to this cause. The small diameter of the intermediate holes is contributory to the same results. Some allowance must also be made for the difficulty of working a machine from a raft on the lake. Comparison of the cores shows a decidedly higher percentage of core recovery, and presumably therefore of rock solidity in all of the other three holes — no. i, no. 5 and no. 15. more than twice as good in its capacity to stand drilling disturbance. A comparison of quality at different depths is believed to be still more encouraging. The upper portions of all holes have poor recovery and comparatively poor looking rock. But in depth there is a marked improvement. In view of the fact that the tunnel will undoubtedly be located somewhere below the -75-foot level, it is really only this lower section that is of vital importance to the project. A tabulation and comparison of core recovery from these lower portions is given below. Under the conditions of work, this is a fair saving and indicates much more substantial rock below the -75' level. There are many pieces 10-12 inches in length and for a 1 inch core this may be considered very good. It is clear, however, from a detailed inspection of the cores, that there is considerable variation somewhat independent of depth. There are occasional stretches of poorer ground in the midst of comparatively sound rock. This is believed to indicate that the crushed condition is confined chiefly to certain zones, and that these zones dip across the formation and across the holes at an angle. They are probably distributed promiscuously throughout the central portion of the valley, but are certainly more abundant and more strongly marked in the vicinity of hole no. 2 than at any other point tested. The rock profile shows that hole no. 2 has also the lowest bed rock. This is a further support to the general explanation of the valley as given above. dimensions In spite of the uncertainties enumerated, the conditions are entirely understandable. There is little probability of finding a worse condition than that shown in hole. no. 2. The permeability or porosity of these zones is of course unknown. The chief reason for believing that underground circulation is not abnormally heavy is the observation that the joints are well filled with chlorite and that other decay is not at all prominent at the lower levels. Furthermore, the rock is a crystalline type of rather successful resistance to ordinary solution agencies and therefore may be depended upon to hold its own in its present condition indefinitely. But because of the poor binding effect of the chlorite it is to be expected that blocks will fall from the roof of any tunnel where it passes through a crush zone. Timbering will be required for protection in places, but the ground will not cave or run. These zones may be expected throughout a total distance of about 700 feet — i. e. the space between no. 1 and no. 15. The chief belt of such ground probably lies between holes no. 2 and no. 5. The tunnel should be located deep enough to take advantage of the improved rock conditions shown at about -100 feet. There seems to be no marked improvement below -100 feet as deep as the drills have gone. GEOLOGY OF THE KENSICO DAM SITE Kensico reservoir at Valhalla, 2 miles north of White Plains, is one of the links in the Bronx river aqueduct. It is to be greatly enlarged and made a very important storage reservoir for the new Catskill system. In line with this plan a new dam is to be built near the old site that will rise 100 feet higher than the present structure. Extensive investigations1 have been made to determine the character of rock floor for this massive dam. Sites both above and below the present one have been studied with the question of safety and efficiency and permanence as well as that of economy of construction in view. Involved with this is also the source of suitable stone for its construction. Geological surroundings Glacial drift covers the rock floor of this and neighboring valleys to a depth of 10 to 20 feet. No rock is exposed in the valley bottom at the Kensico site, but at the extremities of the proposed dam the rock floor comes to the surface in small outcrops. The material constituting the drift cover is essentially a loose, somewhat porous till passing into modified types, especially gravels and sands immediately south of the ground tested. The character of bed rock at the two extremities and beyond the limits of the dam is easily seen from the outcrops to be Fordham gneiss on the east and Manhattan schist on the west. Between, although nothing can be seen, Inwood limestone is found by the borings as was to be expected. No other formations occur, although the Yonkers gneiss, an intrusive in the Fordham at a little greater distance figures prominently in studies of material. The formations are in normal order and are of the usual petrographic character. All dip westward at angles that vary from 45 to 65 degrees and have a general strike a little east of north. It is evident that the whole series represents an eroded limb of a simple fold. 1 These explorations have been in direct charge of Mr Wilson Fitch Smith, division engineer, whose headquarters for the Kensico division is at Valhalla, N. Y- Preparations for construction have already been begun. The Inwood limestone occupies about 800 feet of the bottom and eastern margin of the valley, lapping well up on the Fordham gneiss. The drill cores from this formation are unusually sound. The Manhattan schist shows much broken material. There are many crush zones. This condition increases still farther west along the railway near Valhalla station. at the surface. Results of exploration. .Many borings have been made. They prove the general structure and succession of formations, making the boundaries definite. They increase the evidences of a rather wide prevalence of weak zones — some of them in the gneisses. And they also indicate a more extensive surface decay than was formerly believed to prevail. 3 Depth of decay and perviousness of rock Surface disintegration. Several borings on ground underlain by Fordham gneiss penetrated material beneath the drift and above bed rock that was interpreted as residuary matter from rock decay. All of this material is of local origin. Later exploration in the form of a deep trench to bed rock has proven that there is an extensive residuary mantle of this sort at the eastern side of the valley below the present dam. In places as much as 30 feet exists. Undoubtedly this material is a remnant of preglacial soil mantle that was in some way protected from removal by the ice. Few places are to be seen in all southeastern Xew York where there is so much left in place. In most of it the gneissic structure is still preserved, but the decay is so complete that it can be cut and handled like an impure clay. Weak zones. It has been proven that there are weak zones in the gneisses as well as in the other rock formations. In some places the rock is so poor that no core is recovered for distances of 5 to to feet, and in one hole a seam of this kind 20 feet wide appears. In every case, however, the drill passes through the rotten material into the opposite wall — indicating a zone of considerable dip instead of vertical position. This favors the theory that the weaknesses follow the bedding largely and are perhaps due to difference in the mineral make-up of the beds fully as much as to dynamic disturbances. The walls are generally good. The fragments of core are not much slickensided. In the schist this is probably not as generally true. There are much plainer evidences of crushing movements in the schist. It is a locality where (me of the folds, one well developed farther south, is pinched out and there is rather general crushing of the weaker strata. Depth of decay and perviousness. As deep as borings have gone there is occasional decay and broken material and streaks that are pervious. Final location. 1 "he condition of bed rock, together with other considerations led finally to the selection of a site above the present dam. In general the same features characterize this site. But the rock condition is somewhat improved. On the whole the new situation is a safer one. ervoir have been studied in the field : (i) " Smith quarry," which is less than a thousand feet east of the southern end of the present reservoir; (2) " City quarry," which is on the immediate eastern margin of the reservoir on the east side ; (3) " Garden quarry," which is a new location about 500 feet from the eastern margin about midway; (4) " Outlet quarry," 1500 feet east of the northern extremity of the present reservoir; (5) " Ferris quarries " 1000 feet and (6) " Dinnan quarry " 3000 feet farther north. and Dinnan quarries. The question at issue is the choice of a rock for the facing and finish of the new Kensico dam. In view of the use to be made of the rock, extreme strength is of only secondary importance. But the questions of abundance, distribution, durability, purity, agreeable appearance and working quality are vital. Types of rocks All of the quarries occur in the broad belt of Precambric gneisses that forms the eastern margin of the reservoir extending northward and southward for many miles. The formation as a whole is very complex. But the basis of it is a black and white banded rock chiefly a metamorphosed sediment, known as the Fordham gneiss in southeastern New York. In it are intrusions of igneous rocks of many varieties and most complicated structure — dykes, bosses, veinlets, stringers etc., sometimes in such abundance as to wholly obscure the original type. The most abundant of these are, (a) a rather light colored quite acid rock that is essentially a granite in composition, but has a sufficiently foliate structure to be classed as a gneiss and is the same as the " Yonkers gneiss " occurring farther south, and (b) a dark rock containing much hornblende and biotite which is in some cases essentially a diorite in composition, but has a marked tendency to schistose structure. The former (a) may be called a granite gneiss and the more massive representatives of the latter (b) may be classed as a dioritic gneiss. In both cases at times the blending with the original metamorphosed Fordham gneiss is so intimate that absolutely sharp limits can not be drawn. And this last condition may well be designated as a third case (c). The quarries visited represent all three of these cases. Dinnan, Ferris and Outlet quarries represent essentially the " Yonkers gneiss" type (a) of granite gneiss. Garden quarry represents chiefly (b) the dioritic type of gneiss. Gty and Smith quarries represent the last case (c), or the mixed and variable type. Field character City quarry. In accord with the above differences in type it is found that large quantities of uniform material for such purpose as is proposed can not be obtained from City quarry. The rock there is badly jointed and is variable to a marked degree. It was not thought promising enough to test in detail. Smith quarry. The conditions of Smith quarry are better but there are similar objections. The amount of uniform material is greater. It would no doubt furnish an abundance of material suitable for use in the construction of the dam interior, but is not at this point as. good a source of facing stone as some of the others to be considered. Outlet quarry. Although this rock is characteristic Yonkers gneiss, it has at this place suffered by weathering a peculiar discoloration to such extent as to make it objectionable, both from the standpoint of appearance and perhaps of durability. Garden quarry. There is an abundance of stone at the Garden quarry. It is fairly uniform. It is no doubt good enough from every standpoint of durability. It is well located. It can be quarried readily. But it has a very dark color and is undoubtedly less attractive than a light stone for this purpose. There are no objectionable structures, except where the strong schistose character is developed, and these could be avoided so that with a little selection a fairly uniform stone could be secured. Dinnan quarry. This rock is typical " Yonkers gneiss." There is sufficiently large quantity. It is of good quality. It is situated a little over 2 miles from the proposed dam, but is of easy access. The jointing and other structures do not seem to be objectionable. It will work somewhat more easily than a true granite because of the gneissic structure and it has a good medium light color. The discolorations do not seem to penetrate deep and the rock shows only slight decay. Photomicrograph of Yonkers gneiss from " Outlet quarry " taken in plain light to show prominence of sutures between the grains indicating the beginning stage of disintegration. Magnified about 30 diameters Ferris quarries. The "Old Ferris quarry — is " Yonkers gneiss " considerably more weathered than the Dinnan. It is considered less promising than the " New Ferries " quarry which has been explored by the engineers of the Kensico division. The rock of this quarry site is not all of one quality. There are essentially three varietal facies of the Yonkers gneiss type and relationship. One (a) is essentially a granite. It has a coarse grain and shows almost no foliate structure. It has a decidedly massive appearance ; but it is not of very great extent. This rock is evidently very closely related to the true Yonkers gneiss into which it passes on all sides through an intermediate variety. This intermediate variety (b) has medium size of grain, is only slightly foliated and passes without sharp limitations on the one side into the granite facies and on the other to true normal Yonkers gneiss. It is not so strikingly massive as the granite, but is more so than the gneiss proper. This rock may be called a gneissoid granite to distinguish it from the other. The true Yonkers (c) gneiss surrounds these two special varieties. It is of finer grain than either of the others and is more strongly foliate and is strictly a granite gneiss. Varieties (a) and (b) occur as sort of a lens within the Yonkers gneiss. The extent of the granite as now uncovered at the site is believed to represent its 'limits. The prospect of enlarging the area will not meet with much success. It is essentially a local development connected with the differentiation of the parent magma from which all three varieties were derived. It seems to have been the last of the three to solidify, and it has some of the characteristics of certain pegmatite lenses. Although this is certainly an attractive rock and one against which there is little ground for objection, it is reasonably certain that a sufficient quantity of this variety can not be obtained here for the whole proposed use. And the prospects are not good for locating another quarry of the same quality. The gneissoid granite (b) is of greater extent, in fact it will be found to encroach on the present area of the granite. It is as good rock and almost as attractive as the granite. The regular type of Yonkers gneiss such as that represented in the Dinnan quarry can be obtained in almost unlimited quantity, and, with the splendid showing that it makes in further examination, it has come to be considered the best suited to the purposes of dam construction at Kensico. 4 The dioritic gneiss of Garden quarry 1 Granite. The rock is coarse grained and well interlocked. The chief constituents are orthoclase, quartz and microcline. There are but small amounts of dark minerals, and there is not much decay. Both surface material and the drill core were examined. The deeper material shows a little calcite, that may be original, occurring in irregular grains. They do not seem to indicate decay. There is a little kaolin alteration of the feldspars, but not to a serious degree. There are no injurious impurities in the rock such as might cause rapid disintegration or discoloration. grain, containing quartz, the feldspars and a little mica. There is very little alteration, and no serious decay or injurious constituents. A small amount of seriate and calcite present are not considered of consequence, and as in the case of the granite, the calcite is believed to be original. It is a good rock and gives good durability tests. On badly weathered surfaces the Yonkers gneiss breaks up into a granular product like sand long before it decays to earthy matter. This seems to be caused by expansion and contraction of the different constituents under changing weather conditions inducing a weakening of the sutures. Sometimes there is very little decay even along these sutures, but as they open slightly they become the channels for moisture and staining solutions. This makes the boundaries of the grains very well marked in weathered specimens. light and shows the outlines of the grains due to this cause. 4 Dioritic gneiss (Garden quarry). Rock is of medium grain and with a strong tendency to schistose or foliate structure. The dark grains are hornblende and biotite, the light grains are feldspars and quartz. The rock is fresh, durable and has no injurious constituents. It is good enough for the use in all respects, but has a dark color and is more strongly foliated than any of the others considered. It is evident from these observations that the rocks considered are all of suitable mineralogic character for the purposes of large dam construction. For very large quantities of material, however, it is probable that neither the coarse granite nor the gneissoid granite could be depended upon for uniform supply. The true regular Yonkers gneiss, however, is very abundant, and can be relied upon for indefinite amounts. The dioritic gneiss is also abundant. The immediate region is not capable of furnishing any better rock than those described above. Additional tests Some instructive tests were made by the Board of Water Supply under the direction of Mr J. L. Davis who has charge of the testing laboratories. A few of these applying to the rocks at Kensico are tabulated below. The tests cover : specific gravity, weight per cubic foot, porosity in per cent, ratio of absorption, per' cent water absorbed, ratio of drying 24 and 48 hours, retained water pounds per cubic foot 24 and 48 hours. 2 Porosity gives " the actual percentage of the stone which is pore space." " The difference between the dry and saturated weights of the sample is multiplied by the specific gravity of the rock and the product added to the dry weight. This gives the weight the specimen would have provided it contained no pore spaces. The difference between the dry and saturated weights multiplied by the specific gravity of the rock is then divided by the above computed weight of the poreless specimen. This ratio expressed as a percentage is the actual porosity. Expressed as a formula, the computation is as follows: 3 Ratio of drying. An attempt has been made to determine the comparative and actual rates at which the saturated rocks give up the absorbed water under ordinary atmospheric conditions. " The ratio of drying was computed by dividing the weight of water lost during exposure by total weight absorbed. The weight of retained water was computed." The comparison is most useful in rocks of like petrographic general character. sure tunnel Bryn Mawr is a railway station 2 miles northeast of Yonkers. The general features of the vicinity, its topography, succession ot formations and the boundaries are shown on the accompanying sketch map which is largely copied from United States Geological Survey Folio No. 83. The Southern aqueduct follows southward along a Manhattan schist ridge until, at a point about a mile northeast of Bryn Mawr, a cross depression of so great width and depth is reached that some special means of crossing has to be devised. Near Bryn Mawr station a gneiss ridge rises and continues southward. The proposed line follows this ridge. 1 Unison schist in United States Geological Survey Folio 83. 2 Inwood limestone (middle), the usual coarsely crystalline dolomitic and micaceous type, also called " Stockbridge dolomite " in the Folio, same as " Tuckahoc marble," same as " Sing Sing marble," same as limestone at Kensico dam and also at Croton dam. oldest of all. 4 Yonkers gneiss, the usual type, gneissoid biotite granite very uniform and granular. This formation is an igneous intrusive that cuts up through the Fordham gneiss and is therefore younger. Whether it is also younger than the limestone and schist is not clear. 5 Quartz veins and lenslike segregations of quartz, also pegmatitic streaks, are occasional occurrences in all of the formations. They are most abundant in the schist, but are seen also in the Fordham gneiss. A similar development was encountered in the limestone in hole no. 40. tions of all formations. This last formation (no. 6) is the only one that may be wholly avoided in the tunnel proper. The chief interest lies in its hindrance to exploration and its possible usefulness as a source of sand and gravel supply. Weakest formation. The Inwood limestone is the most questionable ground. This is believed to be so chiefly because of the greater solubility of the rock, its granular and micaceous character, and the probability that a line of displacement accompanied by some fracturing crosses the siphon line in this formation. If a very excessive amount of shattering occurs in this zone it may have induced a condition of disintegration to such depth as to endanger the tunnel. Critical zone The critical zone is probably not far from the contact between gneiss and limestone. There are two reasons for this opinion. The first is related to the nature of the folding. The formations are squeezed into a close syncline pitching northward. In cross section the strata at any point around the head of this trough dip inward, and, because of the more resistant Fordham gneiss forming the floor of the trough, the drainage and seepage and consequent tendency to decay might be expected to follow along its upper contact. Location map showing by the dotted belts the distribution of Inwood limestone in the Hastings- Yonkers district and the position of the Bryn Mawr tunnel section as well as shaft 13 on the New Croton aqueduct with their relations to the limestone belts. Manhattan schist and Fordnam gneiss occupy the rest of the area. The second reason is related to the probable later faulting movements. It is evident from the map [Folio 83] that the formations in the vicinity of Bryn Mawr are bulged up. One would expect the trough which contains the schist and limestone of Grassy Sprain valley to continue uninterruptedly southwestward and join with Tibbit brook valley. But a cross fold has bulged the formations up so much that for a distance of a mile erosion has removed all of the formations except the gneiss. Bryn Mawr station is about central on this bulge. Evidence of such a movement is readily seen on the gneiss along the northerly margin where it slopes down toward the limestone. The movement had developed a little shearing and has tilted the minor folds downward toward the north at angles varying from 300 to 8o° from the horizontal. This angle becomes somewhat more accentuated as the limestone is approached, and it is believed that it may pass a short distance into the limestone border. There is, however, no great amount of crushing evident in the gneiss and this may hold also in the limestone. The fact that Sprain brook crosses the formations along this northerly margin and flows for 2 miles in a southeasterly direction may indicate a still later movement, probably faulting. There is no surface evidence of it except the abnormal course of the creek. But, if there is such a fault, it also crosses the siphon line in the same zone, i. e. in the vicinity of the limestone-gneiss contact, not far from the location of the present course of the brook. Therefore it seems reasonable to conclude that the critical zone is near the contact, probably on the limestone side, and in the vicinity of the present course of Sprain brook. It is also probably cut deepest here by erosion. If this zone is in good enough condition to stand tunneling the rest of the line ought to be. Conditions indicated by borings All rock formations stand very steep. They vary from 8o° to 900. This means that very few beds can be explored by one hole, and that any weakness or crevice is likely to make a showing in excess of its true proportions. The cores show considerable crushing. Some of the fractures are not healed, although weathering from circulation is not present on all of them. The micaceous layers are most affected by circulation. Some beds of this variety are considerably weakened even at depths of over 200 feet. Occasional seams have been encountered that give no core at all for several (even 20 or 30) feet. But the greater proportion of the recovered pieces are comparatively solid even where the total percentage of saving is very low. It is evident that some of the core, a considerable percentage, has been ground to pieces in the process of boring. This is especially noticeable at hole no. 40. 3 The casing that was put down to shut out the sand failed to reach solid rock, and this permitted a continual supply of pebbles and sand to run into the hole and obstruct the work with each pull up. The presence of these pebbles was also instrumental in grinding the core to pieces, and this accounts chiefly for the low saving. 4 After this opening was plugged up with cement, the drilling was continued successfully until a somewhat broken quartz vein was encountered and this has been followed for about 35 feet. Its broken condition afforded another opportunity for fragments to fall into the hole, and on top of the drill, bringing the work for a second time to a standstill. It is certain also that the drift pebbles still fall in. As the formation stands vertical here it is not surprising that any feature should show an apparent extent quite out of proportion to the real value. The quartz vein is probably of no great breadth. Small seams containing mud may also be followed 15 or 20 feet and still be of no great significance in the formation as a whole. The rock fragments (core) recovered in this hole are fairly sound. 5 In spite of the many delays and difficulties of this hole, it is apparent that the general rock formation is not responsible for it all. The failure to reach solid rock contact with the casing has been the cause of part of it. Later the penetration of a rather rare quartz vein, a thing that would not often be found in the limestone, has added to the trouble. Both of these causes are so rare that they may almost be given the value of accidents. But the last 100 feet or more of the hole, from depth 225 feet to 335 feet, shows an unusually questionable condition. Only a few rock fragments are saved and they include limestone and quartz vein matter. The rest is wholly disintegration sand of rather complex composition but carrying very much mica. This is all wash more strongly micaceous. Borings nos. 40, 45 and 46 are all within the zone that was considered, from surface indications, to he likely to carry the deepest gorge and to show the weakest rock. Because of the heavy drift cover (more than a hundred feet) it is manifestly impossible to locate the weakest zone more closely or judge of its exact condition except by borings. Hole no. 42 at station 634 + 28, penetrates 82.4 feet of drift and reaches bed rock at about elevation 21 feet A. T. The rock is good, substantial, coarsely crystalline limestone. It shows as sound condition as can be expected in this formation even under the most favorable situations. Hole no. 46 at station 644 + 77.4 is just south of the brook. It penetrates 72 feet of drift and reaches bed rock at elevation 14 feet A.T. The rock is Fordham gneiss of typical sort and in perfectly good condition. There is no question about the soundness of the rock from this point southward. Hole no. 45 at station 643 + 52.5, 125 feet north of hole no. 46 penetrates drift for about 150 feet (possibly a few feet less, 145 feet). This drift cover is interpreted as mostly sand (modified drift) to 115 feet and a boulder bed from 115 to 143 feet. After the true ledge is reached it is sound and shows no unusual or questionable conditions. It is Fordham gneiss. Interpretation 1 Weak zone. There is little doubt that this last 100 feet of hole no. 40 is in the decayed weak zone that was expected to develop in the vicinity of the contact between the gneiss and the limestone. It would be expected to pitch northward along the floor of gneiss and extend beneath the southerly extremity of limestone at this point [see fig. 36]. 3 Position of old channel. Bed rock surface is lowest at hole no. 45. But since the rock itself is sound gneiss, it is not believed to represent the lowest possible point. This is still more certain because of the fact that the pitch is northward so that this becomes a dip slope on which the prcglacial stream could glide against the edges of the limestone beds [see diagram], and because the condi- tion of the rock a little farther north (at hole no. 40) shows that these limestone beds are actually much weaker than the gneiss. Therefore the deepest portion of the buried channel is to be expected between holes no. 40 and no. 45, and probably nearest to hole no. 40. 4 Depth of old channel. How deep the buried channel may be can not be accurately estimated. But if the same dip slope as is shown by the rock surface from hole no. 46 to no. 45 prevails northward toward hole no. 40, a depth somewhat below -100 feet may reasonably be expected. In the absence of data bearing upon the depth of other portions of this ancient channel or of the lower Bronx river with which it must have been connected, it is impossible to estimate more closely. 5 Interpretation of hole no. 40. There is so little rock actually saved from the more than 200 feet of possible core on this hole that its real character is very obscure. this rotten material may be decayed gneiss within a crush zone. The difficulty in drawing absolute conclusions is increased by the fact that matter falling in from above has been a continued source of trouble and is more or less mixed with the rock material of lower points. Therefore, the fact that the sand taken from the lowest points, 335 feet, is silicious instead of calcareous, may not prove satisfactorily that the rock at that point is wholly silicious. It is worth noting, however, that the harder rock in the upper portion of the hole was in places much crushed and that mud seams were encountered before reaching this last 100 feet. It is also worth noting that the same dip slope of rock surface as prevails between holes no. 46 and no. 45 if continued northward to hole no. 40, would cut that hole a considerable distance (75 feet) above its bottom. In view of all the conditions, therefore, it is judged that there is a crush zone here, that hole no. 40 penetrates it, that it is badly decayed, that the plane of the crush zone dips steeply northward and cuts both limestone and gneiss, that a tunnel at about -300 feet would cut this zone south of station 640 and north of station 642, and that all other portions of the line are in comparatively satisfac- 6 Evidence of faulting. Whichever interpretation of hole no. 40 is taken is in support of some displacement in the nature of faulting between holes no. 40 and no. 45. If the gneiss rock floor is not reached in hole no. 40, then the greater northward slope of it from hole no. 45 to no. 40 than is shown from no. 46 to no. 45 indicates a downward movement. If on the other hand, the identity of the formation in the lower part of hole no. 40 be considered undetermined, and its condition attributed to decay in a crush zone, the presence of the crush zone itself indicates movement of a fault nature. ing points : 1 In view of the fact that the deepest point in the ancient channel is not yet found, and that it will probably go below -100 feet, it would be necessary to figure on a tunnel grade down well toward -300 feet. at that point. 3 The ground at such depth south of station 642 is unusually sound. The ground north of station 636 may be counted good. The ground between 636 and 640 may be considered fair, and the ground from 640 to 642 +, troublesome, containing the chief elements of uncertainty. There has been reference made occasionally in connection with the Bryn Mawr explorations, as well as others, to the remarkable piece of bad ground encountered in 1885 on tne New Croton aqueduct near Woodlawn in the Saw Mill valley. This experience has been the source of much misgiving. Because of its evident importance and close relationship to conditions that may exist in the same formation at points on the Catskill line, an examination of this ground was made for the purpose of comparison. The meaning of that case and its bearing on the Bryn Mawr questions a~e given below : This ground and its remarkable behavior is described by Mr J. P. Carson in the Transactions of the American Institute of Mining Engineers, September 1890, pages 705-16 and 732-52. The south heading was started from this shaft on June 1, 1885. It advanced at the rate of about 80 feet per month for 392 feet through good limestone rock (dolomite), which then became softer. On December 9, 1885, when the heading had reached a point 407 feet from the shaft a fissure was encountered from which about 100 cubic yards of decomposed limestone clay, sand and dirty water poured into the tunnel, partly filling it for a distance of 125 feet. After three days delay, when, only clear water was flowing into the tunnel, the fissure was plugged with straw. The heading was advanced 20 feet further until on December 22, 1885, an outpour three times greater than the first occurred, covering everything in the heading out of sight * * borings were made on the surface with a diamond drill to determine the extent of the soft ground in front of the tunnel. It was found to lie in a pocket in the rock, which had a length of no feet on the axis of the tunnel and extended for a short distance below the invert of the conduit. The soft material, consisting of sand, gravel, clay and decomposed rock had a depth of about 160 feet from the surface to the top of the tunnel. It exerted such a pressure against the timber bulkhead that the 24-inch oak logs used as " rakers " (braces) became crushed in 24 hours and had to be continually renewed. The chief points of present interest are that the tunnel, at a depth of about 160 feet from the surface, and after passing through several hundred feet (407 feet) of good dolomite, came into rotten rock and soft ground no feet across on the line. It was so soft that it ran into the tunnel in great quantities and exerted such pressure as to make progress in it a very troublesome and costly matter, taking " 60 weeks to advance the tunnel 85 feet " and costing " $539 per foot." The material caved in so freely as to form a pit on the surface. Statement of geologic conditions It is not possible to interpret the conditions at this locality as fully as one would wish because of the vagueness of some of the statements, but the following facts and explanation are essentially correct : 1 The rock is the Inwood limestone, the same kind and same general conditions as all of the limestone belts that occur in the region of the Southern aqueduct. 2 The soft ground penetrated at the point in question — 407 feet south of shaft 13 — called in the Carson report and others " a fissure " or " pocket," etc., is in reality a fault crush zone. The fault plane probably dips steeply southeast and strikes n. 500 e. cutting the tunnel line at an angle of something like 20°. 3 The point is well up on the side of the valley more than a hundred feet above Saw Mill river, and the strike of the fault zone in its southwesterly extension cuts into the lower portion of the valley, so that underground circulation would be encouraged along the zone in this direction. 4 The limestone outcrops very near by on the west side of the line and the Manhattan schist occurs near by on the east. The attitude of the beds is such as to indicate a fault of the thrust type, The accompanying figure illustrates this relationship in a cross section at right angles to the axis of the tunnel [see fig. 37] - Interpreted from field observations 5 It would appear probable that this zone was penetrated at the worst possible level, i. e. near enough to its Wholly decayed upper part to furnish no resistance at all to the overlying sand and gravel, and not deep enough to reach the more substantial (although probably crushed) rock that may reasonably be expected to prevail at no very much greater depth. The chief point is that the weak spot has a reason and is not an accidental thing that might be expected just anywhere. But it must be admitted, in spite of this fact, that a casual examination of the locality would not make one suspicious of its existence, and it is surprising that the spot could have caused so much trouble. From the above it will be seen that in several respects the Bryn Mawr case is somewhat similar to this. They both indicate faulting ; they are in the same type of rock ; they both show or indicate caving tendencies. On the other hand, there are certain elements of difference some of which are capable of very materially modifying any conclusion that might be based upon the simple facts of likeness. For example— it should be expected (i) that the fault movement at shaft 13 would be the greater because of lying in the more prominent lines of such displacement of the region, (2) being a thrust movement, the crush effect is probably more prominent at shaft 13 than at Bryn Mawr, (3) occurring at greater elevation above probable circulation outlet, the opportunity at shaft 13 for extensive and rather deep decay is the greater, (4) being cut so near the surface (160 feet), its condition there is not necessarily a reliable guide to the seriousness of decay at a greater depth. Comparison of Bryn Mawr and shaft 13 The following statements embody an opinion on the points raised or suggested in connection with a reference to the New Croton difficulties at shaft 13. The items are therefore treated by comparison or contrast so far as possible : 1 Type of rock. The rock explored at the Bryn Mawr siphon is the same formation as that in the Saw Mill valley cut by the New Croton aqueduct, i. e. the Inwood limestone — sometimes called " Stockbridge dolomite." It is the same also as the other large limestone belts in Westchester county. There are occasional small strips of limestone of another type, but its behavior could not be very different. 2 Soft material. " Is any material of this sort " (like that in the New Croton tunnel near shaft 13) " likely to be encountered either in the crushed zone at boring 40 or elsewhere in the limestone belt? " It is sure to be encountered, especially near hole 40, if that zone is cut shallow. The behavior of the lower portion of this hole is very similar to the described case near shaft 13. The only probability of avoiding it lies in placing the tunnel deep enough to cut more substantial rock. The single hole upon which all this argument is based can scarcely be considered a thorough enough exploration to build up a quantitative statement as to depth or width. holes, of any other such zone on this line. 3 Depth and extent. Under the circumstances, the increased depth makes it less probable that so much ground of like behavior would be found. Again, it is not likely that precisely the same conditions would so effectually halt operations or be considered so nearly insurmountable at this time. One of the many serious objections is that the tunnel would have little strength or resistance to a bursting pressure. It must be admitted that if caving ground were penetrated it would prove very difficult to handle with the gravel cover at the depths now considered, i. e. 300 feet or more below the surface. 4 Water. " AVhat are the probabilities in regard to the quantity of water to be met in the crushed zone near boring 40? Can any limit be set which it would be extremely improbable that the inflow would exceed, on account of the topography of the country and the nature of the overlying materials?" drift is sand and gravel that is probably saturated and in such condition as to permit easy flow to any lower outlet. It may readily carry 8-10 quarts of water to the cubic foot or about 2 gallons. The area covered by such deposits is about 2500 feet long on the southerly base along the creek and at this margin is approximately 150 feet deep. The northerly margin is variable and reduces in places to o feet in thickness. It may, however, really represent 500,000,000 cubic feet of this gravelly material holding 1,000,000,000 gallons of water as a nearly permanent supply. This overlying material is necessarily a menace of no mean proportions. Every crevice or crush zone remaining unhealed will have water and plenty of it, the inflow being limited only by the size of the cracks and their abundance until the reservoir should be drained. There is no hardpan bottom to act as a dam. Outside additions to this permanent supply are confined to that received from rain and the stream. The rainfall on the area and immediately available as addition to the underground supply in the lower sands, together with the stream flow, which would probably sink into the sands, if an attempt to drain the underground supply were made, may be expected to furnish additional water at a possible rate of 2500 gallons per minute. How much of all this is available at tunnel level depends wholly upon the openness of structure in the rock. There is nothing else to materially control the permanent and additional supply. There is evidence in hole 40 of considerable crushing. That means capacity for water circulation, but how much no one can tell. There is also much rotten rock in the same hole. This means that circulation has been easy and effective, but how much now no one can tell. The single hole (no. 40) in the absence of any other corroborative data is not sufficient to base more elaborate or precise quantitative estimates upon. This limestone is, as all limestones are, more easily attacked by circulating water than most other rock types [see Rondout Valley]. The Inwood limestone such as occurs at Bryn Mawr is crystalline, often contains much mica and then is inclined to be foliated in structure, and it prevailingly stands steeply inclined. Because of these features in which it differs from the Rondout Valley limestones, it is likely to be more generally affected by decay along the zones permitting circulation than any of the Rondout Valley types. The Rondout Valley limestones are affected along joint planes, but the effect is almost wholly confined to a simple enlargement of these crevices. In the Inwood an additional effect is the weakening of the sutures or bond between the individual granules resulting in a tendency to weaken the whole mass as far as there is much penetration of seeping water. It would have less tendency to produce openings or caves, but greater tendency to produce a rock that would crumble in the hand or that would gradually assume the condition of a lime sand or a micaceous mud. As to the effect of water from the aqueduct on fresh portions of this rock, it is certain that the rock would be attacked wherever exposed to direct action. Its method of attack is by solution, and the rate of attack may safely be reckoned as not materially different from that assumed or being established by experiment and experience on the Rondout V alley types. In the final consideration of the difficulties at Bryn Mawr the engineers have decided to abandon the tunnel plan. It is probable therefore that no additional explorations of direct bearing on the problems of this ground will be made. DELIVERY CONDUITS IN NEW YORK CITY Hill View reservoir is the terminus of the Southern aqueduct. The Catskill water is to be delivered at this point, just north of the New York city line on the Yonkers side, at an elevation of 295 feet. From this reservoir the water is to be distributed by an independent system of conduits to the principal centers of consumption in lower Manhattan and Brooklyn. It is believed that distribution can be most economically made and the system be most permanently established by constructing the main trunk distributaries as tunnels in solid bed rock at considerable depth below all surface disturbances. Preliminary investigations have been carried on by Headquarters department, Mr Alfred D. Flinn, department engineer, beginning in 1908. As the active work of exploration was entered upon Mr William W. Brush, department engineer, was assigned to this special division of the department's work and most of the preliminary exploration borings were planned and finished under his immediate supervision. With the resignation of Mr Brush to take the post of deputy chief engineer in the Department of Water Supply, Gas and Electricity, Mr Walter E. Spear, department engineer, was secured to continue the difficult work of finishing explorations and preparing for construction. Studies of conditions affecting such a system and explorations designed to test the ground in line with these studies1 have been made. The work thus far done in an exploratory way has been confined to one main distributary. ditions affecting possible conduits, trial lines were laid out on the xFew engineering enterprises, probably, have been planned with so careful regard for all known geologic conditions. The geologist and the engineer worked alternately on the same problems until, in the opinion of both, the best possible line was selected. It is the writer's belief that so systematic a method has seldom if ever been carried out in engineering work of this kind. On this account, and in part to illustrate some of the preliminary stages in such work, many of the original facts and arguments and suggestions are given without change in the following discussion. city map from Hill View reservoir to Brooklyn by three different routes. So far as the topography and city development and other engineering considerations could be forseen either route could be u<ed. Studies of all kinds were expected to indicate which would be the most favorable and whether or not it might be advisable to shift even the best one to still more favorable ground. These are shown on the accompanying map which also covers the local geology of the immediate vicinity of the lines [see pi. 32]. When the problem of the practicability of a rock tunnel for distribution conduits was first studied, several general questions were raised which indicate the lines of investigation followed. 2 Will the rock at moderate depths be such as to permit successful and economical construction of tunnels to be used under the hydraulic pressure due to Hill View reservoir? 3 Does the character of rock in the vicinity of the lines vary sufficiently to materially affect the cost of a tunnel if the lines be shifted approximately 1000 feet either way from those shown on the original map as trial lines? 4 Are the suggested locations of conduit lines adapted from a geological viewpoint to the construction of pressure tunnel conduits, and, if not, what changes in these lines would be advisable ? 6 What borings and other field investigations should be undertaken to determine the practicability of construction of pressure tunnels along the lines suggested? Geological formations There are six local formations of sufficient permanence and individuality of character and of sufficient areal importance to be treated as units in this study. These are described in some detail in part 1, but for convenience are briefly listed as follows: 2 Manhattan schist, the most abundant formation, chiefly mica schist with very subordinate hornblende schists, and usually with abundant pegmatite lenses and veins. which shades into impure, micaceous varieties. 4 The Fordham gneiss, varying from a thinly schistose or quartzose rock to a strongly banded or a very massive and much contorted gneiss. The oldest formation of the district. squeezed into a gneiss. Younger than the original Fordham. 6 The Ravenswood grano-diorite or as it might be called in engineering practice, granite ; an original, intrusive rock now somewhat gneissoid from pressure. Younger than the original Fordham. The Manhattan schist, the Inwood limestone and the Fordham gueiss are cut by veins or dikes of coarsely crystalline granite, technically called pegmatite. They are of irregular distribution and do not affect the tunneling operations one way or another. All the formations older than the glacial drift have been compressed into a series of northeast and southwest folds, and all have as a rule a steep or almost vertical dip. The axes of the folds are not horizontal, but usually pitch downward to the south at low angles. Erosion has developed a series of ridges trending northeast and southwest. The limestone being a softer and more easily eroded rock, almost always underlies the valleys or flats and the river channels. It is certain also that there is some faulting. Rock at depth The distribution of geological formations along the proposed lines has been shown on the accompanying map [pi. 32]. In general the kind of rock at tunnel depth will be the same as at the surface as indicated on the map for each point. Such error as there is, arises from two causes : (a) Uncertainty as to the exact location of some of the contact lines between two formations (usually due to drift cover), and (b) dip and pitch of the strata. features alone. In the second case (b) it must be appreciated that nearly all of the formations dip eastward at a very steep angle, so that a formation would usually be found to extend a little further east at depth than at the surface. And also all formations pitch southward, so In nearly all these cases, however, the obscurity of the actual surface boundaries is as great a source of uncertainty as the effect of dip and pitch, so that the boundaries as mapped may be considered sufficiently accurate for this comparative study of the lines. It is worth noting that the rock at the proposed depths of tunnels would be, as a rule, more substantial than at the surface. But there are several places on all of the lines where the exact condition is unknown at the surface as well as at depth. The chief points of this character will be noted in a later paragraph. A comparison of the three lines submitted as the basis of examination— (a) the westerly one, (b) the central one, (c) the easterly one [see accompanying map, pi. 32], as to rock formations likely to be cut by them, furnishes the following figures : Speedway 16400 Manhattan schist (to 135th st.) 2- 000 Along contact between schist and limestone 4200 Inwood limestone with one weak zone (to s. end of Morningside Park) 1 The statements of quality and extent of certain formations and zones are capable of some modification as exploratory work progresses. Some of these are noted in later sections of this report under special headings, such as The Lower East Side, and The East River-Brooklyn section. For the present purpose, as showing the development of the geologic basis of the project it seems preferable to leave the accompanying comparisons in their original form as presented to the board. 21000 From Central Park to East river — no outcrops — mostly Manhattan schists at tunnel depth. Condition largely conjectural1 — probably mostly good rock with occasional weak zones 8 000 Yonkers gneiss — good quality 13000 Fordham gneiss — good quality 6 800 Inwood limestone, probably mostly in fair condition, except 1 Explorations since conducted by the Board of Water Supply have proven the quality and character of the rock floor at these places. For the revised statement on these sections see the special discussions. Nearly all is Manhattan schist of good quality 1 000 Crossing Hell Gate — Inwood limestone 1 200 Crossing Hell Gate — Fordham gneiss of good quality 1 800 Astoria point — probably Fordham gneiss of good quality 1 000 Crossing another limestone belt Argument on choice of line In judging the quality of rock and its suitability for this conduit the factors of most weight are the same as those repeatedly mentioned in connection with other portions of the Catskill aqueduct line. That is, in brief, that the harder crystalline rocks of the Fordham gneiss1 and Manhattan schist types wherever known; to be free from fault crushing and surficial weathering are the best variety ; that the more heavily buried areas of these rocks, together with those limestone areas that are known to be the most substantial of its class, should be regarded as fair or second grade; that the more obscure areas of limestone and all portions crossing faults or rivers or crush zones in any rock must be regarded aspoor or third grade. This rating is based wholly on rock character and without any consideration of cost of construction. In addition to these differences of quality, it appears from a study of the areal geology along the respective lines that a tunnel would pass across limestone contacts from one formation to another six times on line A, four times on line B, and seven times on line C. These may all be considered points of probable weakness. All of the lines cross belts of well known weakness believed to represent fault zones. Line A crosses three such zones, line B crosses two, and line C crosses at least three. Furthermore, all of the lines cut limestone for greater distances than seems desirable or necessary. The weakest ground and the most uncertain quality of ground that can be mapped falls within the limestone areas. In this respect line A with 13.9$ of limestone ground is preferable to line B, with 25.3$ or line C, with 15.2$. From the above it is apparent that line C is least defensible. Line A has some advantage over both of the others, especially in quantity of first grade rock quantity of first and second grade together, low amount of the known poorest grade and small extent of the so called " unknown " ground. 25.3$), and the chief advantage of line A over line C lies in its much smaller amount of " unknown " ground (6000 feet vs. 18,400 feet or 7.0^ vs. 22.6$). On these grounds line A is the least objectionable of the three lines proposed. But it is also clear from an examination of the field, as is shown on the accompanying map [pi. 32], that it is possible to avoid some of these objectionable features or certain parts of them and materially improve the figures by shifting the line to a sort of compromise position between line A and line B. This compromise line, or the trial lines from which the final tunnel line may result, should follow as closely as possible the gneiss and schist ridges and should avoid the limestone areas and known weak zones wherever possible. Depth of tunnel The rock formations in general at the required depths are no more objectionable on Manhattan island or in The Bronx than at other localities on the Southern aqueduct. There are weak places and crush zones to be crossed and some of them can not be avoided by any possible manipulation of the line, but these most questionable spots constitute but a small proportion of the whole distance. The depth most suitable must depend chiefly upon the depth necessary at the worst spots. Comparative cost of construction if lines are shifted The question is best answered by reference to the geological map. It will be noted especially that the belts of the different rock formations are usually narrow, and that they run nearly parallel to the average direction of the lines. Therefore a shift of line to no great distance would at many points place it within an entirely different formation. It is also notable that all of the lines run along or near the contacts between formations for long distances. At such points a very small shift would wholly change the type of rock and rock quality. Some shifting is desirable. In general it may be assumed that the limestone belts would be easiest and cheapest to penetrate wherever they are fairly substantial, but they undoubtedly also contain the greater proportion of weak and troublesome ground and must be considered least desirable from the standpoint of maintenance and durability. The gneisses are probably most expensive to penetrate and the schists, medium. Both are more expensive than limestone but both arc more likely to prove acceptable for other reasons. no very serious shifting. J n the general consideration of relative advantages of different possible locations of the line, it is believed that the following large features are of most immediate importance: along a contact zone. It is distinctly preferable from a geologic standpoint ( I ) to follow the ridges, (2) to keep in the hard formations, (3) to avoid many changes from one formation to another, (4) to keep away from contact zones, and (5) to avoid weak zones, if possible, or cross known troublesome zones at the most advantageous point. Recommendations of new lines F, G, H, I The original lines A, B and C are marked on the map in blue [pi. 32]. In addition several trial lines are sketched in yellow, any one of which would give better geological conditions than any of the three original lines. The newly suggested trial lines differ from each other chiefly in the points at which they cross the limestone belts and weak zones. In all of the n the central idea has been to follow the gneiss and schist ridges as persistently as possible. All unite at Central Park and are intended to follow Fifth avenue, Broadway, the Bowery and Market street to Fast river along one of the original lines. North of Central Park they differ from the original lines. The westerly one crosses the Harlem river at 176th street and may be designated line F. The easterly line may also cross the Harlem river at 176th street and may be designated line G; or it may continue southward and cross the Harlem at 155th street. It will then join the first one in the vicinity of 144th street and is called line II. The alternative easterly one which crosses the Harlem at 155th street and follows Seventh avenue to Central Park is line I. 7 600 Yonkers gneiss — good quality 15000 Fordham gneiss — good quality 2 000 Fordham gneiss — probably 2d grade 1400 Manhattan sclhst — good — to junction 12000 Manhattan schist — along Central Park — good 20600 To East river — Manhattan schist — less known1- — -(fair) (2d grade) which brings it to the Harlem river where the other line (F) is joined. Although the line is about 1400 feet longer, it avoids some low ground (2000 feet) along the east bank of the Harlem river, some of which may be in poor condition. Total length of line, 87,000 feet. 8 400 Yonkers gneiss — good quality 23 800 Fordham gneiss — good quality — to Harlem river 1 000 Crossing Harlem river — probably fault zone in gneiss From this point the line is the same as F and G. Its chief advantage is the great distance which it has in Fordham gneiss. Total length of line, 85,600 feet. extend into the territory here marked as too little known to classify. As a group it is especially noticeable that the new lines F, G, H, I, have a very much lower percentage of contact zones and limestone. The percentages of gneisses have been notably increased, and the unknown and questionable formations have been reduced to approximately the lowest terms. grade also. A comparison on this basis with the original lines A, B, C indicates that these new lines F, G, H, I, make a better showing, especially on first grade rock and that all show decided reduction in the third grade ground. 1 Now known to be first grade. On geological grounds, therefore, it is confidently believed that any one of the new lines (F, G, H, I) would give decidedly better results than any one of the original ones (A, B, C). The poor and the questionable and the unknown ground can not be wholly avoided by any possible line, no matter how roundabout, in these lines, approximately as drawn, the objectionable points are reduced to a minimum with almost no increase in total length of conduit. The objectionable portions are also restricted in large part to the Line I is the shortest possible defensible line. Its chief objectionable feature is a rather long stretch, 6600 feet of limestone, from 135th street to Central Park, upon the quality of which there are no data. It crosses the Harlem river fault probably in gneiss. But it crosses the extension of the Manhattanville fault in limestone. Lines F, G and H are almost equally defensible. Line G is longest, but is in some respects — especially in following the ridge crests — one of the best possible locations. It should be appreciated that many other matters, such as municipal works already completed or projected, or matters of engineering practice, are likely to make it necessary to modify any line proposed, and that the final line is more likely to be a compromise, considering all interests. A graphic representation of the comparative merits of the proposed lines is given in plate 33. This is strictly a geologic study. The lines are properly placed on an outline map of the city corresponding exactly to those drawn on the geologic map, plate 32. The geologic formations that each would cut are represented on longitudinal sections which follow each line, and the attitude and structure of each formation are indicated. Revised lines Subsequently two revised lines based upon the preceding studies were examined to determine preference. Later one of these, or a slight modification of it, was adopted as the one to be explored. It was soon determined on the same reasoning as was applied to the first group of lines that the most westerly line — the line keeping as much as possible within the gneiss and schist ridges — would be the most likely to give satisfactory conditions. By this method of selection the unknown or untested and doubtful ground was reduced to its lowest limits. It was found that nearly all of the very weak spots could be located by inspection in the northern portion of the line, but south of 59th street the question is decidedly more difficult because of the heavy drift cover. No rock outcrops occur south of 30th street, and one is reduced to the evidence of deep borings. begin. 1 The Harlem river crossing, where the distribution conduit line crosses the river just below High Bridge [see later description]. The only good evidence as to character of rock at this place is from the pressure tunnel of the New Croton aqueduct which crosses the river a short distance above. 2 The Manhattanville cross valley (125th street depression). This is the most important cross depression on the island of Manhattan. It is apparent after a little investigation that the bed rock floor lies deep and that if it were not for the drift filling the tides would surge through this valley making a direct connection between the Hudson and East river. It was the least known as to depth and character of any point along the proposed line. 3 The depression between Morningside and Central Park. At that place limestone on the crest of a pitching anticline reaches farther south than on either side and is more deeply eroded. The other zones of large importance are in southern Manhattan the geology of which is a special study. STREET The necessity for exploration in certain sections of this area can not be appreciated without a statement of the local geology and especially of the revision of both areal and structural geology that the writer has based upon an exhaustive study of all the available drill cores and other data to be found in southern Manhattan, East river and Brooklyn. Below Central Park there is now little geology to be gathered from a study of the present surface. But as far south as 31st street the bed rock geology is pretty well known from earlier reports and from recent improvements that have exposed the underlying rock. All of this portion is mapped as Manhattan schist except one small area of serpentine at 59th street between 10th and nth avenues. There is no reason to modify this usage. A careful study of a great number of rock borings from the Pennsylvania Railroad tunnel across Manhattan at 32d street proves beyond question that bed rock is Manhattan schist, including almost all known variations and accompaniments, for the whole width of the island along that line. Still farther southward the points that have yielded exact information about bed rock are less numerous, and below 14th street are confined to deep borings or an occasional very deep excavation for foundations. Even these sources of information are lacking over large areas. The greater number of borings available are along the water front. Their distribution is such as to indicate that the west side and central portion and southerly extremity of the island are all underlain by Manhattan schist. This is true eastward to the East river at 27th street, and as far eastward as Tompkins square at 10th street and almost to the Manhattan tower of Brooklyn bridge in that vicinity. To the eastward of these limits, i. e. to the eastward of the line projected from Blackwell's Island to the Manhattan tower of Brooklyn bridge, there is a more complicated geology. The borings of the East river water front are decidedly variable. They are certainly not all Manhattan schist of the usual types. Those most unlike the Manhattan are at the same time most like some varieties of the Fordham, and indicate that these formations both occur. The lack of any data in the beginning of this investigation except on the water front made it impossible to draw more than very general lines. Drawn in this way, the lines of course are too straight, but it is certain that they indicate more nearly the actual existing areal distribution of formations than any of the maps now in existence.1 They indicate a southward extension of the Blackwell's Island belt of Fordham gneiss toward the Manhattan tower of Brooklyn bridge. How much of this anticlinal fold of Fordham actually brings this formation to the surface it is impossible to say, but that it may be expected to be encountered along this line is evident. On the east side a parallel belt of Inwood limestone is indicated and this again is succeeded by a Fordham gneiss area which occupies the rest of the eastern margin. Explorations made along the line of the gas tunnel across East river at 72d street2 indicates comparatively narrow belts of limestone there in both the east and west channels. The limited width of limestone at these points, together with the occurrence of two strongly developed disintegration zones, seem to indicate rather extensive squeezing out and faulting of this formation along fault planes 1 In the summer of 1908 the writer was assigned the task of studying in detail the evidences of geologic structure beneath the drift in southern Manhattan. Before any drilling was attempted in the city by the Board of Water Supply, a thorough canvass was made of all previous borings in this district and the cores and records were personally inspected. More than 300 such borings were found in which some of the core could be secured for identification and classification as to formation and condition. Most borings were given no weight at all in the final summary of this evidence unless the rock core or at least fragments of it could be secured. After all of these newly assembled data were tabulated and plotted on the map, it was evident that if the identifications were correct the areal and structural map of southern Manhattan needed extensive revision. A new map therefore was made and presented to the chief engineer of the Board, October 30, 1908. This has been used since as the basis for exploration of the Lower East Side section. This original tabulation and map only slightly modified was published under the Areal and Structural Geology of Southern Manhattan Island [N. Y. Acad. Sci. Annals, April 1910, v. 19, no. 11, pt 2]. The extensive explorations of the board have made further revision necessary [see accompanying map, pi. 34]. Exploratory boring is still in progress (October 1910) and some slight modifications of boundary lines may yet be made. parallel to the strike. Such movements are capable of cutting out the intermediate limestone entirely from between the schist and gneiss. How much of such modification exists, in the almost total lack of data bearing upon the question, it is impossible to say. The intermediate belt is indicated on the accompanying map [pi. 34], as a limestone area. At one point at least the limestone does occur in the older borings, i. e. on the southeastern margin of the Manhattan pier of the Manhattan bridge (bridge no. 3), at the foot of Pike street. On the Brooklyn side no formations of this series except the Fordham and its associated igneous masses, such as the Ravenswood granodiorite, have been identified within the area under study. Limestone is reported (Hobbs reference to Veatch) near Newtown creek, a little beyond the eastern margin of the present map. Structure of the East river area Manhattan side. In all of the area south of 59th street, structural features are even more obscure than the areal geology. There is no reasonable doubt but that weak zones will be found as frequently in the Manhattan schist portion of this area as on the line north of 59th street, but they can not be indicated as closely. No cross fault of large consequence can be identified, but there is some evidence of a minor zone that should be encountered on Fifth avenue, in the vicinity of 32d street. The Pennsylvania tunnels and the subway both cross this line and so far as known there were no serious weaknesses developed. There is nowhere any evidence of an important depression like the Manhattanville valley. It is confidently believed that the problems on this southerly portion of Manhattan are involved chiefly with the longitudinal structures produced by folding and faulting and subsequent disintegration along such zones. Crossing of East river From 59th street to the East river there seems to be no reason for a preference between the two lines P and Q.1 On the Brooklyn side likewise there is no known geological reason for preference. Such basis for choice as is now known relates to the East river channel alone. Since this is at the same time the most difficult section of the line to explore and probably the most uncertain section to estimate as to condition and consequent depth of tunnel, it would be especially useful to be able to make a decisive selection of crossings at once. Such evidence as has any bearing upon this question has already been used in formulating the interpretation of geologic structure given in the foregoing sections of this report. If the succession and boundaries of formations as outlined are reasonably close to the actual conditions, it would appear that line P (the southerly one just above Manhattan bridge ) lias some advantage over line Q (near Williamsburg bridge). The chief elements in this advantage are as follows : contacts. 2 From the evidence of borings made in the East river at 14th street1 it appears probable that a belt of schist similar to Manhattan schist in quality (whether accompanied by limestone or not there is no direct evidence) lies in the river channel toward the east side and in all probability extends southward in the middle of the river at Williamsburg bridge. This would be cut by line Q. The uncertainties of this association are of sufficient importance to throw the balance of present choice toward line P. 3 If the theory that the East river course is due chiefly to zones of weakness following fractures or faults is true, their possible comparative condition as they cut through different formations must be taken into account. There is little doubt on this point but that, in zones of similar original disturbance, those in the Fordham gneiss have suffered less extensively from disintegration than those cutting either the limestone or schist. Therefore, obscure as it may be, the preference is again in favor of line P. 4 If, furthermore, the course of the river is due to cross faulting or any similar or related displacements or movements, an inspection of the structural map indicates that the controlling zone followed by the river as it crosses line O must have a general strike northwest, while the corresponding zone that crosses line P strikes east. Of these two types (directions) of fault zones, so far as they may be judged to have influence in the adjacent area, there is no doubt but that the northwest type (the set that has a northwest strike) is both the more common and the more important. If this general tendency is also true here, then on this account also line P may be considered slightly more favored. In reality not much weight can known. 5 If, as may well happen, the present East river is displaced1 from its old channel by glacial drift, so that it is essentially an evicted stream, there may not be as pronounced a channel or as weak ground to cross at such points as at those where the old channel is still occupied. In such case both of these lines are favorable. 6 On the other hand, the crossing of line P is almost a mile nearer to the great Hudson gorges, to which doubtless this portion of the preglacial East river was tributary, and consequently its bed rock channel, if it is the real preglacial channel, may be expected to be deeper and the accompanying disintegration (so far as it may be controlled by this factor) may be expected to reach lower than at points in similar surroundings farther up stream. It is impossible to say how much weight should be given to this objection. It does not seem to be of sufficient importance to fully offset the favorable features indicated in items 1, 2, 3 and 4. On the basis of these studies line P (the southerly one) near Manhattan bridge was chosen as the site of preliminary exploration promising the most favorable results. Eater this was shifted a short distance without introducing any new conditions. SPECIAL EXPLORATION ZONES Exploration by borings1 and other methods have been made at all questionable or uncertain points along the line. As was expected in the beginning five places have required elaborate exploration and some exceptional conditions have been proven. The original geological investigation based upon surface study as outlined in the foregoing pages served to locate these spots accurately. 1 The Harlem river crossing at 167th street, where the aqueduct will cross from a ridge of Fordham gneiss beneath the Harlem river, where the whole thickness of Inwood limestone will be cut, to the ridge of Manhattan schist above the Speedway on Manhattan island. 2 The Manhattanville cross valley, a low pass crossing the island at about 125th street. The part explored extends from St Nicholas to Morningside Parks and crosses a zone with very low rock floor in the Manhattan schist. 3 From Morningside to Central Parks. The line crosses the strike of the formations at this point and cuts a longitudinal fault and anticlinal fold which tends to bring the Inwood limestone within surface influence. 1 Exploratory work has been in direct charge of Mr T. C. Atwood, division engineer, who has followed all stages of it almost from the beginning. In the later exploratory work an immense amount of detail and a very complex lot of data has accumulated requiring constantly the services of a man with some special geological training. Mr John R. Healey, formerly in the testing laboratory, was transferred to this special field. He is probably more familiar with the multitude of details resulting from boring operations along the conduit line than any one else. Except for the care and good judgment used by these men in preserving data, and the wisdom of the men who planned the line and methods of work before them, much valuable geologic data would have been lost. Notwithstanding the best efforts of the consulting geologist some really critical points escape unless some one constantly on the ground is directly interested in them as a part of the regular responsibility. 4 The Lower East Side zone. On Delancey street east of the Bowery, the line crosses the structure and at this point the whole series of crystalline formations appears. Besides complicated structure there is also exceptionally deep alternation or decay of bed rock. i Harlem river crossing Geologically the Harlem river between 155th and 200th streets has the same relation to local formations for the whole distance. It flows on the Inwood limestone bed which stands almost exactly on edge, while the east river-bluff is formed by the underlying Fordham gneiss, and the west, by a strong escarpment of Manhattan schist which extends southward throughout the whole of Manhattan forming the backbone of the island. At the selected crossing a short distance below High Bridge, near 167th street, the schist-limestone contact is in the river and appears to be a low weak spot [see detail of record]. The limestone-gneiss contact however is in the flat east of the river bank, near Sedgwick avenue and seems to be more substantial. The structural detail and relations are shown on the accompanying profile and cross section, [Pi. 35]. It is observed by examination of the data secured by borings that the limestone formation at this point is exceptionally heavily impregnated with pegmatite dikes and stringers, and that interbedded schist layers are large and numerous. Several borings have been made and on them is based the only judgment possible of the actual structure and physical condition of rock. In most cases the evidence is easily interpreted for these points. The most weakened spot, as well as the most difficult to interpret in all its detail, is the limestone-schist contact. It is judged that hole no. 17 cut through this contact zone. This boring is located in the river 50 feet from the Speedway (west bank) on the proposed tunnel line which crosses a short distance south of High Bridge. It is known as hole no. 17/C38. Because of the the wash and core saved and because of the suggestion it gives Fig. 38 Key map showing plan of exploratory borings at the Harlem river crossing, location of the New Croton aqueduct which crosses the Harlem in a pressure tunnel and the Old Croton aqueduct which crosses the river on High Bridge 13 — 46=Black river mud (mostly river silt) 46 — 48=Sand with decayed wood (peaty wood) 48 — 7o=Quartz and garnet sand rather clean (glacial) 46 — 70=Lumps of peaty matter coming to the surface at intervals indicating occasional small layers of peat (glacial) Effervesces with acid. This shows no foreign matter. It is chiefly residuary decayed rock in place and represents silicious and micaceous limestone. It is decayed, very impure, Inwood limestone Inwood limestone 128 =White and drab lumpy residuary matter (kaolin) and earthy substances. Effervesces. A more impure Inwood. Also shows several pieces of core of a porous, rotten limestone. Inwood Mostly clay but still no foreign matter. Residuary material from a more silicious bed. A few pieces of hard, impure limestone at 133 feet quartz, chlorite, lime. Effervesces 164 — i73=Many pieces of typical Manhattan schist. A fair amount of core for the conditions. Rock is not so badly decayed but is broken into small pieces. Rock is Manhattan schist of typical character. enough to belong to the Inwood limestone formation. The lower 9 feet (164-73 feet) is typical Manhattan schist. The intermediate ground 135-64 feet is transition variety. The conditions indicated by this one hole are consistent with those known for the New Croton aqueduct tunnel 2000 feet farther north where, according to the engineers' drawings, the formations also are overturned. Fifty feet of decayed rock is shown in this hole. The contact is undoubtedly decayed considerably to a depth of more than 200 feet below water level. Another boring put down to test conditions at still greater depth nearby explored the rock to -442.7 feet. Because of the information it gives about the deeper bed rock, a summary of the record based upon examination of the material is given : o to -94 River muds and drift filling (glacial and recent) -94 to -96 Transition to residuary matter -96 to -127 Residuary matter and badly decayed Inwood limestone Geologic cross section. The accompanying cross section [pl- 35] embodies an interpretation of all the data secured in the Harlem river. It is now known that the limestone is overturned slightly at both contacts. The nature of these contacts makes it seem probable that there is very little of the limestone squeezed or cut out by movement. Therefore this crossing gives a fairly accurate measure of the thickness of the Inwood. This is approximately 750 feet. No section about New York city is more accurately determined. 2 Manhattanville cross valley In northern Manhattan the schist ridge which forms the backbone of the island and has a relief of more than 100 feet, is cut across by a prominent valley that extends from the Hudson at 130th street eastward to the Harlem Flats and East river. This valley is nowhere more than 25 or 30 feet above the sea level and is drift filled. Previous to the recent boring explorations of the Board of Water Supply its true depth to rock floor was unknown. The few borings recorded, however, indicated a depth of more than a hundred feet. One such boring at 129th street and Amsterdam avenue is reported as penetrating 109 feet from surface without touching rock. Another of similar results is located at 125th and Manhattan streets where a depth of 204 feet failed to touch rock. Besides determining rock floor in the present case, it was important to determine rock structure and conditions. It appears from surface features that this cross valley probably follows a fault zone along which there has been weakening of the rock and consequent disintegration and decay. If this is so it would be advantageous to find the limits of it and determine what displacement effects were produced. It has been surmised by all students of local geology that such cross faults may lift the blocks on the south side of them, one of the chief indications being the fact that in spite of a strong southerly pitch in all the formations they do not rapidly disappear below sea level. The accompanying profile and explanatory section indicates the principal results of exploration [see pi. 36]. Badly crushed ground has been found in the holes near the north end of Morningside. Park but the rock, when found, is not very badly decayed. The rock floor is very low, almost 200 feet below sea level at the lowest. It appears that if the drift were stripped off from this valley the Hudson and Long Island sound would unite across the Harlem Flats and Manhattanville forming a channel and outlet much deeper than the present East river course. This is more strikingly true of the southerly extension of this low ground southward along Morningside Park. A very deep and prominent preglacial stream came down from the gap between Morningside and Central Parks. It is not yet proven that the fault has really raised the Morningside block. At least if there is such displacement it is not of sufficient amount to bring up a different formation at any pointyet examined. It would be possible for the limestone to be brought up to the surface, but except for a few pieces of interbedded limestone no evidence has been secured. The occurrence of this, however, is thought to indicate proximity to the limestone contact. General geologic conditions established. Fourteen borings have been made for the special purpose of determining exact conditions. On the data of these holes there are several features now established beyond question that were originally given only as probabilities. The most important of these may be enumerated as follows : 126th streets, and its profile can be plotted. 2 A part of this ground is badly broken, as if belonging to a fault zone, but most of the floor thus far tested is not in had condition, i. e. it is not very badly crushed or decayed. 3 The drift cover in this cross valley is more than 200 feet deep over a distance of more than two blocks on the proposed line (from 123d street to Manhattan street). of hole no. 33. 6 The contact line approaches nearer to Morningside Park in passing southward, touching the park between 110th and 113th streets and the contact is probably not overturned in this southerly extension. 3 Morningside to Central Parks The contact between In wood limestone and Manhattan schist follows nearly parallel with the Morningside Park boundary on the east side, but, because of its form, actually touches the park only at the southern end between noth and 113th streets. The Manhattan schist forms an escarpment because of its more resistant character and this eastward facing cliff and slope forms Morningside Park. St Nicholas Park, farther north, from 128th to 155th streets has the same structural relations. In both cases the present escarpment stands back from 200 to 500 feet from the actual contact. As the formations all pitch southward and are pretty closelyfolded, the higher formations gradually appear and at 110th street another parallel ridge of Manhattan comes in above the limestone in the trough of the next syncline to the east. This forms the north end of Central Park and from this point southward Manhattan schist is continuous. But between the Morningside belt of schist and the Central Park belt at 110th street lies an anticline of Inwood limestone also pitching southward and gradually passing beneath the schist which encroaches upon it in a long wedge until a few blocks farther south it passes wholly beneath the schist, which from that point is continuous. 242-280.71 feet=-to el. -242.71 feet=Inwood, very coarse type of limestone. Poor core showing. Muoh broken c Hole no. 12. In Morningside Park at 113th street Surface elevation+28 feet 84-335.15 feet=to el.-307.15 feet= Manhattan schist, typical with considerable pegmatite. But all good sound rock, not much broken and standing at about 65°-8oG d Hole no. 16. Corner of Manhattan avenue and 110th street Surface elevation=+55 feet Material : 0-44 feet=to el.+il feet=filled ground and mixed material 44-159 feet=to el-104 feet=fine sands and silts interpreted as chiefly modified drift. Much of it very fine and the lower portion rather micaceous and angular throwing a little doubt on the exact line of demarcation between drift and residuary matter 55-245 feet = decayed rock ledge 248-254 feet=solid rock ledge (limestone) / Hole no. 2 at 123d street, 100 feet east of Morningside Park East Surface elevation+30 feet Condition of the limestone schist contact. The finding of Inwood limestone above the Manhattan schist in hole no. 33 at 121st street east of Morningside and the fairly sound condition of both typeis raises the general question of the condition of contact zones as compared with fault zones. There are three important facts to consider bearing on this case : (1) The contact zones are commonly weaker than either formation alone and (2) at this particular point an abnormal relationship is shown by the overturned strata (the limestone lying above), and (3) the fault zones are always weak and extensively decayed. Because of the abnormal position of the limestone here, lying as it does overturned, a weaker more pervious rock upon a more substantial and less pervious one, it appears to be reasonable enough to find the limestone and schist fairly well preserved, under conditions where a vertical or a normal position would have encouraged decay because permitting a more ready circulation. But there is a further conclusion that seems allowable, i. e. the fault or crush zones are more extensively decayed than the simple contact or transition zones. And contrariwise, where an especially extensive decay is encountered, it probably is to be associated with a crush zone due to fault movement rather than with any other structure. A further inference seems allowable from the data of these holes. It is probable that these fault zones do not follow the contacts or bedding exactly but cut across at low angles, sometimes coinciding with the contact lines and sometimes falling wholly within the limestone or the schist. Great depth of decay at south end of Morningside Park. The finding of approximately 150 feet of decayed rock in hole no. 16 and of nearly 200 feet of similar type in hole no. 36, all so rotten that the material came up as a mud, raises a very difficult question as to the conditions that make such extensive decay possible. Hole no. 7 (113th st.) shows extreme decay to elevation -204 feet Hole no. 16 (noth st.) shows similar condition to elevation -250 3 There is no reasonable doubt but that the geologic structure at the south end of Morningside Park is that of a pitching anticline carrying the limestone beneath the schist in its southward extension. The evidence on these various possibilities is not complete enough to make a conclusion very reliable. But there are two or three factors that have a bearing and they unite pretty well in supporting one view. These factors are: (a) the exact alinement of these three holes, (b) the crushed core of hole no. 7. (c) the overturned position of the formations 10 blocks farther north, (hole no. 33), together with the apparently normal position in hole no. 16. All of these points are consistent with the opinion that we have to do here with the crush zone of a fault, one that runs rather straight and one that follows not far from the contact of the schist and limestone at this point. And it is probable that the weakness follows the west margin or limb of the limestone anticline as it plunges beneath the schist. Such evidence as there is favors this view. If that is true, then one may expect that the worst ground is not very wide, but that one probably can not go entirely around it. The best line would run south far enough to get above the limestone, and then cut across the weak zone nearly at right angles. It is certain that the ground improves southward. Later borings are all confirmatory of the conclusion that the weakness is narrow and dies out rapidly southward as soon as the limestone passes well beneath the schist. No bad ground has yet been found on 106th street where the tunnel will probably be located. 4 The East river section Preliminary studies of southern Manhattan and the East river led originally to the conclusion that the portion of the East river forming the great eastward bend from 32c! street to Brooklyn bridge probably has a simpler geologic structure than those portions farther north or south. It was long known that the structure at Blackwells Island is very complex and involves all of the local formations in close folding and considerable faulting. But there seemed to the writer after studying all available data, good reason to believe that the river leaves this belt when it bends to the eastward and that it i> in this part a displaced stream. In that case the East river coidd bo flowing upon a floor of gneiss of a most substantial sort. Explorations are now complete on a line that crosses the river from Clinton street, Manhattan, to Bridge street, Brooklyn. All borings have found good sound rock at moderate depth and all are comparatively shallow holes. Their positions and depths and rock types are tabulated below. gneiss The rock floor is thus very uniform as to contour across the East river at this point. No water course yet explored about Manhattan island has shown so simple conditions including as it does sound rock and shallow channel. The rock varies a good deal but is prevailingly a coarse grained granodiorite. In places it is very garnetiferous and at others is banded or micaceous, but all belong to the Fordham formation as a general formational unit. Borings in the East river made by the Public Service Commission both above and below this point found an occasional deep hole with excessive decay to more than a hundred feet without securing sound core. At this crossing the deepest point in the channel to sound rock floor is 81 feet. It is certain from these results and from others in adjacent ground that the East river does not occupy in this part of its course the original stream channel. Tt has been displaced (evicted) by glacial encroachment and has never been able to reoccupy the lost course. Therefore, instead of the river following a belt of lime- stone around this big bend as was formerly supposed, it follows no rock floor structure at all but is in this part of its course wholly superimposed. The original valley lies farther to the west cutting through the midst of the Lower East Side where the more complicated geologic structures again prevail. Borings at intervals of 500 feet have now been made on the Brooklyn side of the East river to Gold street and Myrtle avenue. So far as developed there is no other formation than the Fordham and the associated granodiorite within the area covered. The rock floor is remarkably uniform at an elevation of from -70 to -90 feet. The accompanying section shows the relations of rock floor to present drift surface [fig. 40]. DELANCEY AND CLINTON STREET SECTION The proposed distributary conduit turns from the Bowery eastward on Delancey to Allen street, thence on Allen to Hester street, thence on Hester to Clinton street and follows south on Clinton to the East river. This so called Lower East Side section includes one of the most complicated geologic structures in New York city. The most complex portion extends from Christie street on the west side to Monroe street on the east. Between these two points all of the crystalline rock formations form a series of parallel beds that are folded together so closely that they stand practically on edge. This general fact and the approximate location of the several beds have been proven for some time. But the more exact structure, with the depths to which the beds go before bending upward again, and the distances through each one are only approximately determined by the exploratory borings to date. The chief uncertainties arise from the fact that the beds are also faulted and the dips of the fault planes are not yet determined and the amount of displacement is unknown. The difficulty of forming a good estimate of the obscure points is greatly increased by the fact that no rock of any kind is to be seen at the surface. Judgment is based wholly on borings. There are other important questions covering the zone, such as : (1) depth of serious decay, (2) location and width of these decay belts, (3) general physical condition of the rock at certain levels, (4) length of tunnel that will cut each formation, (5) best depth for safe construction. offered as the writer's interpretation of borings to date, and its more direct use is as a working basis and guide in conducting explorations. The western half of the section may be accepted as more accurate in minor detail than the eastern. To simplify the section it is drawn on a line crossing this zone more directly than the conduit as laid out, i. e. through holes 28 and 5 and the borings are projected along the strike of the formation to the section line. All the data therefore are used and the structure is not distorted, but the distances through each bed would be greater on the conduit line because it runs more diagonally across the formations. Borings. The following tabulation of borings and interpretations upon them forms the basis of the present ideas of structure and quality of rock on the Lower East Side. The borings are given in order from west to east, and all points are neglected except those bearing upon geologic structure. 28 The Bowery and Delancey street Surface elevation 40.5 feet Manhattan schist with very poor core recovery to el. -260 feet Inwood limestone to bottom at el. -360 feet 84 Delancey street east of Christie Surface elevation 41.8 feet Surface elevation 41.7 feet Rock floor -98 feet. Rock is typical Fordham gneiss — banded and very micaceous — to bottom —123 feet 225 North side of Delancey street east of Eldridge street Surface elevation 40 feet Fordham gneiss in good condition with interbedded limestone at bottom at el. -550 feet to bottom at el. -671 feet 25 Delancey street between Eldridge and Allen streets Surface elevation 40.6 feet Rock floor -82.3 feet. Banded Fordham gneiss — dip about 6o° or less — bottom at -171 feet 223 Grand street east of Allen street Surface elevation 41.2 feet Inwood limestone with structure at about 60 feet — 700 Enters fairly sound rock and has continued to over 600 feet with dip as low as 200, toward the bottom 15 Delancey street near Ludlow Rock floor -130 feet. Rock a close grained schistose limestone, Inwood, showing foliation at about 45 0 231 South side of Hester street opposite Norfolk street Surface elevation 32 feet Decayed gneiss and no core recovery to el. -300 feet. This boring was continued as no. 303 under a subsequent contract and carried to el. -525 feet with only a small recovery of Fordham gneiss The rock is Fordham gneiss of the black and white banded type, with dips varying from 300 to 8o°. For a very short distance at el. -275 feet dips of io°-i5° were recorded Core recovery very good 11 Hester and Clinton streets Rock floor -204 feet. Badly disintegrated and no core to -279 feet. Unusual rock, identified as a mica schist of obscure structure (not typical). Some calcareous portions. At first this was thought to belong to the Manhattan formation, but it is probably a schistose and rather unusual facies of the Fordham series. This hole was subsequently reoccupied and deepened as no. 220 under another contract with the result that an interbedded series of gneisses and limestones was shown to a total final depth reaching el -660 feet. Rock cores indicate dip of about 6o°. 201 Clinton street between east Broadway and Henry street Surface elevation —31.3 feet Rock floor elevation uncertain because of failure to recover core and the obscurity of the material washed up. Interbedded limestones and gneisses of Fordham series were recognized from el. -336 feet to el. -680 feet 51 and 207 Henry street between Clinton and Montgomery Rock floor -214.6 feet. All badly decayed to great depth mostly believed to belong to limestone and underlain by interbedded Fordham gneiss at about -345 feet 221 Clinton street near Monroe street Surface elevation 22 feet Rock floor -65.5 feet. Fordham gneiss of granodiorite type Two borings are of special interest and significance, and because of the rarity of such details being recorded they are given more fully below. Inland. Special interpretation of hole no. 202, on Hester st. near Suffolk st. This is one of the very deep borings, on the proposed distributary conduit, put down to investigate the character, condition, and structure of the rock through which the proposed tunnel would pass. 190-214 quartz, hornblende, chlorite, mica, disintegration sand5 d Decayed ledge rock capable of furnishing an occasional core 214-224 core — several pieces of coarse feldspathic, quartzv mica rock 402-447 Coarse quartz and mica disintegration sands and finer quartz-mica, hornblende-chlorite cuttings that do not look badly decayed. The rather surprising thing is their failure to core 497-5 12 Core — a quartz biotite, feldspar schistose rock that is rather easily disintegrated but does not show bad decay. Resembles the Fordham formation more than the Manhattan dip about 6o°, common black and white or gray and white bands in good solid condition. Thin sections and microscopic examination of the rock indicate bottom perfectly crystalline, well interlocked, foliated rock with constituents in good sound condition Discussion of meaning of this hole There were three rather puzzling features about the data of this hole at the time it was made: (1) The fact that Fordha m gneiss was penetrated at a point so far to the west; (2) the finding of a small bed of quartzose limestone in the midst of other types ; (3) the finding of both schistose rock closely resembling the Manhattan and typical Fordham gneiss in the same hole with so little space between. tween Madison on the east and the Bowery on the west belongs to the Fordham than at first supposed. This very much improves the outlook for safe and easy construction. The third point, i. e. the finding of schists and gneisses in the same hole introduced more difficulty of interpretation. This difficulty was considerably increased by the fact that the ledge is so badly decayed and so broken up in the drilling that no typical material for identification could be secured in the upper portion. There is no doubt as to the finding of Fordham in the lower portion. Later explorations support the conclusion that the whole belongs to the Fordham series. When this boring was first made, the schistose portion was. thought to be the Manhattan formation, and the limestone could then be Inwood. Subsequent exploratory work at other points has proven that the Fordham itself shows such schistose facies rather commonly where associated with the interbedded limestones. This is now the accepted interpretation for the whole eastern half of the Lower East Side belt covered in the present discussion. There probably is some faulting. But whether the fault plane dips east or west and how much the total movement is. has not yet been developed. This, however, is a more vital question than would at first appear, for if the fault dips east the ground to the west of it is probably all Fordham of good quality and will be easily explored, whereas if the fault plane dips to the west the whole west side for several blocks is much more uncertain. It is probable that the majority of the rock lying west of it will be of better quality than found in this hole. On Henry street midway between Clinton and Montgomery I )rill boring no. 207 has been put down to a depth of more than 655 feet (approximately -633). The material is of unusual quality and behavior and therefore seems to require special study with a view to reaching a correct interpretation. The most essential points of the drill record are given below. -212-240 feet micaceous clay — judged to be residuary because of the abundance of mica and the scarcity of worn quartz grains and rarity of foreign particles ■c Decayed rock ledge preserving original structure 251-377 feet=quartzose and micaceous disintegration sands and calcareous clays that effervesce in acid. Much pearly mica d Decayed rock leclge representing Fordham gneiss formation (377-489 feet) — no calcareous matter 377-489 feet=quartz and pearly mica disintegration sand varying from coarse to fine and mostly of very light buff color r Disintegration matter from a chloritized hornblendic gneiss of too little cohesion to witb stand the grinding action of a drill of so small cross section (13/16 inch). (487-532 feet) 487-532 fcet=fine dark colored disintegration sand composed chiefly of quartz, chlorite and mica, the material is of same composition as the cores secured just below f Core from more substantial rock — a hornblendic gneiss sound enough in part to withstand the drilling process and save a small amount of core (532-655 feet) All close texture and highly chloritic 581-596 feet — 2 small pieces (two very brown, hard pieces) are probably not natural — " drillite," i. e. a peculiar product formed by the drill when it is run too dry and partly fuses fragments of rock and flakes of iron from the drill into a -compact rocklike mass 646-655.5 feet — 16 pieces of — a white and black and red blotched rock — a garnetiferous gneiss. The rock is not a common type but a similar variety is sometimes seen along the margins of the granodiorite intrusions and belongs to the Fordham gneiss series. drill lias not departed more than 50 from the vertical. 3 Behavior of drill. It has been possible to drive the casing down after the drill without reducing the size and without enlarging the rock hole to a final depth of 625 feet. The hole filled after each pull up as much as 100 feet with matter that either ran in from a crevice or was furnished by disintegration of the walls or was simply the settling of matters held in suspension during operation. These settlings or corings, as the case may be, were of large amount (100 feet + ) when the drill was cutting far below the casing and small in amount (5 feet) when the casing was driven down near to the bottom. This matter then increases as the hole is deepened again below the casing. Cutting and progress are rapid and easy. 4 Examination of the rock, (a) Hornblendic gneiss. A mieroscopic examination of the green hornblendic gneiss shows that the rock is not badly crushed and that the different original grains are well interlocked. But the more easily affected mineral constituents are very generally decayed and have become especially modified on their surfaces where they interlock with other grains. The matter developed is mostly chlorite ^- a mineral that is very soft and one that in this case fails to furnish a very firm bond between the grains. A disrupting force exceeding the strength of this soft mineral therefore, such as drilling with a small bit or forcing the drill, causes the grains one by one to roll out or break apart and furnish the suspended matter that seems to be so abundant in this hole. b The rock below 646 feet. This is a very unusual type of rock, the petrographic character of which need not be taken up here. It appears to be simply a contact variety, such as sometimes is devel- c Bed rock The decayed matter still preserves the bed rock structures in a sample taken at 347 feet. From this point downward there is decayed rock ledge gradually becoming more substantial d Formations represented After bed rock is reached the first 100 feet is so altered that identification is not certain. At 350 feet, however, the calcareous nature of some of the material is observed, and on this ground largely it is believed that an interbedded limestone layer is penetrated down to about 377 feet. From that point (377 feet) the material is very silicious and not at all calcareous and the core when obtained is distinctly gneissoid. This lower portion below (377 feet) is therefore judged to be typical Fordham gneiss. e Character of contact Normally the interbedded limestone lies conformable to the structures and beds of Fordham gneiss. The structure in such pieces as show it indicated a dip of about 70-800. Therefore the formation must stand very steep. But, so far as can be seen in the fragments secured, there is no direct evidence of a fault contact or anything abnormal. The extremely deep alteration of the rock is the chief unusual feature. It seems to require a better chance for water circulation than is natural in the undisturbed rock of either formation. For this reason, I am of the opinion that there has been movement in this zone that weakened the rock enough to encourage water circulation. That the upper 100 feet of ledge is very rotten can not be denied, but it is certain that this lower portion of the hole is not in so bad condition as the low saving of core would lead one to think. The grains are affected by chloritic alteration in such manner that they can not resist much disrupting force. The small diameter of drill used subjects the whole core to enough strain to cause the gradual pulverization of the rock. This affects both the core that has been cut loose and the hole wall that is further subjected to the thrashing of the drill rods. A larger size core would make a very much more encouraging and fair showing. There may be an occasional small seam so badly decayed that it is encouraged to run or cave under such treatment. But there is absolutely no evidence that slumping or caving is common or even likely on any considerable scale. The material that partly fills up the hole when the drill i pulled up is believed to be in considerable part the settlings of suspended matter which during the agitation of drilling is distributed through the rising column of water. The reduction in volume (10 gallons being fed and only 5V2 gallons being recovered) due to rock porosity is favorable to such behavior of the loosened material. SUMMARY OF LOCAL GEOLOGY. Formations. Only three formations are represented in the rock floor of this section. These are the regular crystallines characteristic of all southeastern New York. 2 Inwood limestone or dolomite, and 3 Fordham gneiss, including the Ravenswood granodiorite as a special intrusive member, and an unusually strong development of the interbedded limestones and associated schistose facies. These formations have their usual relation — the Manhattan above and youngest, the Inwood intermediate, and the Fordham underneath and older. These simple relations, however, are much complicated by dynamic disturbances of more than usual violence so that the series is thrown into folds so close that the individual beds stand almost on edge. In addition lateral thrusts of that same time or later have broken the strata and faulted them in several places. This complicates the structures still more, and, since the stage of the work. Fault zones. As nearly as the material recovered can be classified and accredited to the above three formations it has been done. On this identification together with the location of points of greater decay the chief fault zones are drawn. The chief ones are judged to be thrust faults but it is possible that one is a normal fault. Such a combination is comparatively rare where the zones are so close together, but it seems to best explain the relations of beds as interpreted from identification of the present borings. It is not an unknown association though in this region. It probably indicates faulting in two different periods. This is consistent with the observation also that some of the fault breccia ground is not much decayed while others are badly affected. Probably the later movements have not allowed rehealing of the crevices and they are then the lines of chief circulation and alteration. It is clear, upon examination of the section as now known,1 that both the eastern and western belts of limestone are too thin and narrow to accommodate the whole Inwood limestone. The Inwood normally is a formation of about 750 feet or more in thickness. It is therefore certain that a part of it has been cut out by squeezing or faulting. If by faulting then there would be expected to be in each case somewhat greater decay than usual along the fault zones. The fact therefore that such decay zones are found along one margin of the limestone bed in each case leads to the conclusion that faulting is the true cause. In some cases thrust faulting would be required to produce the result and leave the beds standing in their present relations [see pi. 38]. INTERBEDDED LIMESTONES OLDER THAN THE INWOOD The finding of limestone beds within the Fordham gneiss formation so persistently in the Lower East Side borings is one of the geologically interesting and rather surprising results of recent exploration. All of the borings in the Fordham gneiss area in this particular district except those near the East river have shown some limestone. The individual beds vary greatly in thickness, ranging from only a few inches to many feet. Because of the steepness of the dip of the beds and the obscurity of this factor in many borings it is sel- dom possible to compute their thickness closely. It is probable that most of them are not over 5 to 10 feet thick, although rarely a thickness of 25 or 30 feet may be represented. It is certain also that a considerable number of separate beds are penetrated. Alt attempts to correlate the limestone cores from different adjacent holes have so far met with little success. No doubt some of those cut at great depth in one hole correspond to others cut higher ire an adjacent hole. But the differences in thickness are notable evert in the best cases, and it is evident that little dependence can be put upon uniformity of thickness as a factor in correlation. The foldings and crumplings. and shearing have probably affected the limestone members of the series more than any others. Limestones in comparatively thin beds are, under such conditions, especially liable to excessive thinning and thickening" through recrystallization and rock flowage. It is not at all likely that any single bed at present preserves much uniformity of thickness. In some places they are pinched out entirely while in others they may attain a thickness much greater than the original. It is possible also that some of them are repeated by folding. Whether or not this is true in the Lower East Side section no one can tell. On the whole there is no direct evidence of repetition in this way. After making allowance for all possible duplication there is still a surprisingly large number of limestone interbeds represented- — probably 10 — a larger number in succession than is known anywhere else in southeastern New York [see pi. 38]. In petrographic character these so called limestones are all essentially very coarsely crystalline dolomitic marbles or silicated dolomites of still more complex constitution. Occasionallv a very pure carbonate rock is represented that corresponds in appearance very closely indeed to the best grades of the Inwood, but there is no doubt whatever of the true interbedded relation of these limestones. Their similarity of appearance to the Inwood in certain facies is so great that from the petrographic evidence alone one could not differentiate them. Their fixed relation however is unmistakable and they belong unquestionably to an entirely different geologic formation^ from the Inwood — a much older one, in fact the oldest known formation in southeastern New York — equivalent to the Grenville series of the Adirondacks and Canada. The silicated facies contains many of the common products of metamorphic processesRecrystallization has produced micaceous minerals such as phlogopite and chlorite in abundance. Original and secondary quartz is plentiful. Serpentine, tremolite, diopside, actinolite, occasionally chondrodite, and rarely metalic ores are found, in many cases the limestone passes by transition gradually into a more and more silicious faciei until the rock is simply a silicious Fordham gneiss with quartz, mica and feldspar as the essential constituents. There is seldom a sharp break between the two types. Many pieces of apparently simple gneiss will show effervescence of a carbonate constituent with acid. The silicious beds of the gneiss series proper immediately associated with the limestone layers are also more silicious or more micaceous than the average Fordham. They are essentially micaceous quartzites and mica schists and the rock generally lacks the strong black and white banding that characterizes the common or typical Fordham gneiss of other localities. It is this facies of the gneiss which most closely resembles certain facies of the Manhattan schist, and when the rock is much decayed or badly broken or is ground to pieces by the drill the confusion is still greater. The micaceous variety may readily be mistaken for Manhattan schist and the accompanying limestone may equally be mistaken for Inwood. The occurrence of interbedded limestones of the Fordham series is probably more common than was formerly believed. They are not very often seen on the surface areas of gneiss. Possibly this i^ largely due to differential weathering and erosion which together tend to obscure those portions of outcrops where such beds maj occur. But the type is well known. Mr W. W. Mather in his Geology of the First Geological District [1843] interpreted certain limestones in the Highlands as interbedded in their relation to the gneisses there. Later workers were inclined to disregard his views on this point and there was a marked tendency to place all limestone occurrences in one formation. Some of the geological maps have been made in this way. The writer, however, raised the issue again in an article published in 1907 under the title " Structural and Stratigraphic Features of the Basal Gneisses of The Highlands," a N. Y. State Museum Bulletin 107. It is certain that there are interbedded limestones with the gneisses in The Highlands. More recently, the writer has recognized similar occurrences in the typical Fordham gneisses of The Bronx, New York city. The vicinity of Jerome Park reservoir is the best locality in all southeastern New York to see this interbedded development. The best exposures are at the following places. One of these occurrences was known to the geologists of the United States Geological Survey [New York City, Eolio No. 83] but it was regarded by them as an infold of the Inwood. An examination of all four occurrences will convince one that they are not infoldings. In at least two cases the structure accompanying the beds is actually anticlinal instead of synclinal. These occurrences in the vicinity of Jero.ne Park reservoir are essentially the same as those disclosed by the borings of the Lower East Side. In spite of its thick drift cover — 50 to 200 feet — there are more limestone interbeds known there than in any other area of similar size in tbe region. It is entirely possible that a thorough exploration in certain other belts might reveal an equally elaborate development elsewhere. The substantiation of interbedded limestones as a prominent element in certain fades of the gneiss series and their association with typical silicious gneiss layers with transitional relation emphasizes still more the strictly sedimentary origin of at least som; portions of the Fordham series. Other observations lead to the conclusion that they are the oldest members of the series and that the igneous associates, of which there are many, are all younger intrusives. One of these later intrusives is the Ravenswood granodiorite which cuts into the eastern margin of the Lower East Side, forms the floor of the present East river channel at the point of aqueduct crossing and continues as far as explorations have been carried into Brooklyn. Structural detail of Lower East Side What the detailed structure of the Lower East Side is, it is impossible to say at the present stage of exploratory development. Its general features of structure are fairly clear. The Manhattan schist, which is the universal floor rock of the central and western parts of Manhattan island, extends only a short distance east of the Bowery. The Inwood limestone comes to the surface of the floor at Christie and Forsyth streets. An anticlinal ridge of gneiss comes up at Eldridge and Allen streets. Then a syncline of Inwood limestone is pinched into the next three or four blocks and from rock floor. As much of this detail as it is now possible to classify has been included in the accompanying drawing, plate 38, in which special attention has been given to the interbedded limestone occurrences. In view of the fact that a tunnel is finally to be constructed through this section which will cut the whole series of formations and structures at a depth probably between el. -600 and -700 feet, it is clear that much greater accuracy of geologic interpretation is soon to be attainable on many of the more obscure points. Because of this also it is not advisable to attempt a detailed structural cross section at the present time. It can very well await the more complete data to be gathered during construction of the tunnel. TURES. Evidences of postglacial faulting and other recent movements have of late attracted a good deal of attention. The experience of San Francisco in the exceptionally disastrous earthquake and lire, traceable directly to earth movements of the nature of faulting which dislocated or injured the water conduits rendering them tiselcss, is fresh in the minds of men everywhere who have public responsibilities of this kind. If displacements are occurring at the present time, or if any related movements are continuing, or if there is evidence of recent disturbances of this sort in this region, they have a decidedly important bearing upon the permanence of all engineering structures that cross them. Xo undertaking is more vitally concerned with this question than the Catskill aqueduct. Although the principal factors to be taken into account have been considered in other connections [see "Faults" and "Folds," pt i] a unified statement may encourage a more intelligent understanding of the bearing of these structures in southeastern New York on this specific question. The region included in this discussion extends from the Catskill mountains to New York city. It will be convenient, for the purposes of this argument, to divide the whole area into three districts whose boundaries are determined by decided differences in complexity of geologic history. These lines necessarily follow closely the boundaries of greater stratigraphic unconformities. The youngest groups of strata have suffered only such changes as have accompanied movements of later geologic periods. But before they were formed the underlying groups of rocks were just as profoundly affected by earlier disturbances. In this region, at least, three such groups of large importance exist. The oldest or lowest has been affected by not only everything that has influenced the younger strata but by disturbances of a still earlier time which verv much increase their complexitv. prevalence of Siluric and Devonic strata, i. e. all strata above the Hudson River slates. These strata have been affected by only one great mountain-making movement — that of the Appalachian folding, and minor disturbances of still later date. B Hudson river district. This includes that portion of the region lying between the northern border of the Highlands and the Shawangunk mountains. It is marked by the prevalence of Cambric and Ordovicic strata, i. e. Hudson River slates, associated with Wappinger limestone and Poughquag quartzite as the chief bed rock. These strata have been affected not only by the Appalachian folding but also by a still earlier one — that of the Green mountains and the Taconic range. They were folded into mountain ranges and worn down in part again before the Siluric and Devonic strata of district A were in existence. Therefore as a structural problem this district (B) is approximately twice as complex as the other. C Highlands district. This includes all of the region commonly known as the Highlands of the Hudson as well as the rest of the area south of the Highlands proper to New York city. Its rocks are the oldest — much the oldest. They had been folded into mountain structures and in part worn down before any of the others were accumulated. They have also suffered extensive igneous intrusion so that in places these igneous types prevail. And besides they have been metamorphosed far beyond the point of any other group. Xo other series of strata has been so profoundly affected. They form the lowest group. All things considered this district should be structurally three times as complicated at the first one (A), and adding the igneous and metamorphic complexities, it is probably more near the truth to consider this Highland district four or five times more complex. All of the formations from the oldest to the Middle Devonic are involved. For the specific formations and their succession and relation the reader is referred to that discussion in part I [see p. 29, et. seq.]. Except the most westerly part of the region, that occupied by the Upper Devonic strata, all formations are compressed into folds. Many of the smaller folds, especially those in the Catskill district, are still complete. The easy subdivision of strata possible in this district also simplifies the problem of detecting small changes of altitude. Rut for the most part the larger folds have been beveled off extensively by surface erosion so that only the truncated limbs are now to be seen, and the strata therefore appear as narrow belts that dip steeply into the ground. This is more marked in the Hudson river district than in the Catskill, and is still more strikingly true of the Highlands. There are evidently at least three different epochs of folding interrupting the processes of sedimentation and followed by periods of erosion before sedimentation was again resumed. These breaks constitute so called stratigraphic unconformities and occupy the relative positions indicated in the foregoing tabulated scheme [see pt 1]. In each epoch of folding the compressive forces accomplishing this work seem to have acted in a southeast-northwest direction causing successive series of folds with a northeast-southwest trend. The total amount of crustal shortening accompanying these movements is not known, but that it must be many miles is indicated by the fact that the strata of the older series of formations stand prevailingly on edge. All stages between small amount of movement to very great displacement are represented. Accompanying the folding in each epoch there has been a tendency to rupture and displacement of the " fault " type. There are multitudes of them varying from movements of too little amount to be regarded in a broad way to those of several hundred feet. Most of the larger and more persistent ones are strike faults and follow the main ridges or valleys, sometimes governing the location of escarpments or gorges. Dip faults crossing the formations also occur and doubtless have guided the adjustments of many tributary streams, and occasionally portions of the larger water courses. The thrust fault is most common. This is especially true of the larger ones and particularly those parallel to the trend of the other structural features. ments. All of these effects are common. Many of those faults dating back to the earlier epochs are obscure and not readily located. Many of the older weaknesses of this sort have been healed by recry^talli- zation so that they are now as sound as any other portion of the rock. A good deal depends upon the type of rock and the conditions under which the movement took place. In some of the more open ones, circulating water has seriously affected the rock and in places there is extensive decay even in the harder crystalline formations. Age of the faulting. The chief epochs of folding and faulting are those of the mountain-making movements — one Precambric, another Postordovicic, and still another Postcarbonic. All of these ck'te very far back in geologic history, and since the last of these, nothing akin to them in importance has been felt in the region. Jersey and Connecticut. Whether or not there continued to be slight movement along some of the older lines it is now impossible to say. It is at least clear that all of the great movements belong to very ancient time, and that the last period of geologic time as we know it for this region, has been one of comparative stability. The chief exception is evidently connected with the continental elevations and depressions of the glacial epoch. Recent movements. The effects of glaciation make it possible to determine whether or not there has been further movement in postglacial time. Conditions are not everywhere favorable enough to detect minute changes, but where they do obtain, the evidence is capable of very definite interpretation. The essential features of these conditions are unevenness as left by the glacial smoothing can not be mistaken. If on such a ledge, as now exposed, there are steplike offsets or minute escarpments that could not have remained had they been present during the ice action, then there must have been displacement to this extent, since the original smoothing took place. A few such evidences have been found in New York and New England, and have been noted in geologic reports. W. \Y. Mather in his report on the First District of New York ( 1843) pages 156-57, was the first. The data as now known may be found in the last bulletin of Geologic Papers of the New York State Survey [see N. Y. Slite Mus. Bui. 107 (1907) p. 5-28]. The following para- 8 Attleboro. Mass. In addition to these there is reference to similar occurrences at St John, XT. B. and in the province of Quebec. All of the known localities lie a considerable distance beyond, north and northeast, of the Catskill aqueduct line. Causes of displacement. In southern New York all of the cases of postglacial faulting yet discovered lie in the area of slates belonging to the Hudson River series. Whether the belt now occupied by this formation is therefore to be considered the most unstable zone, or whether there is some tendency to slight readjustment inherent in the slates themselves causing these movements, is not clear. It would seem consistent with known recent geologic history to connect these displacements with the general elevation and subsidences accompanying and following the glacial occupation. It is. perfectly clear that the whole continental border in this region suffered considerable subsidence during glacial time. Also the terraces and deposits along the Hudson- prove beyond question that during the ice retreat, at the very close of the glacial occupation, the land surface stood from So to 150 feet lower than now. Therefore an elevation of this amount has occurred in postglacial time, and probably, judging from the condition of the terraces themselves, took place soon after the glacial ice withdrew. The stresses and inevitable warpings accompanying these mass movements seem to be sufficient to account for all displacements known to be of this age. There is nothing in them that necessarily promises a renewal of mountain folding. But it appears that the movements liave almost all been of the thrust character and in this respect they differ not at all from the commoner type of the region. Amount of displacement. The greatest throw noted on any single Postglacial fault in eastern New York is given by Woodworth as 6 inches, and he remarks that this is imperfectly shown. Usually the displacement is distributed over a zone in which several small faults occur instead of a single larger one. This may mean that the whole disturbance is essentially superficial. At Copake, at two different spots, a total of more than 7 iuches was measured within a space of 12 feet. Woodworth thinks that the total displacement for the locality may exceed 2 feet. At Pumpkin Hollow a total of 17 inches is estimated. Conclusion. If such rates prevail over larger areas beneath the drift, it is clear that rather profound changes would be indicated. But thus far there is no indication of such continuity. Likewise if it were certain that the movements are now in progress, it would be a matter of greater concern. But there is no direct evidence to prove it. Estimates of the length of postglacial time differ greatly. The shortest ones worthy of consideration range from about 5000 to 10.000; the longest run above 100,000 years. 25,000 years. Adjusting the postglacial faulting problem then to these, time estimates the summary of it all would be as follows : Somewhere within postglacial time, i. e. approximately 25,000 years, movements of strata have developed at a few places in eastern New York that appear as small faults with total throw in each locality varying from a few inches to perhaps as much as 2 feet. Whether the movement has been gradual and continuous or concentrated largely into some small portion of this time is not known. Whether the effects are extensive or, on the contrary, very local and superficial, is likewise unknown. But in any case there are no known instances of violent and large displacements, such as would be likely to cause great damage to sound structures, in this region in postglacial time. Artesian flows, 142. Ashokan dam, construction of, 13 ; elevation of reservoir, 17; stone used in construction, 38; geological features involved in selection of site for, 109-16; location map, 113; Olive Bridge preferable location, 116; to be finished first, 1S3. Cat Hill gneissoid granite, 52, 57. Catskill aqueduct, water supply project, 9-16; generalities of construction, 14-15; estimation of cost, 15; present plans for, 15; time for completion. 15 ; problems encountered in the project. 17-24; gathering data, 21-23 > relative values of different sources of information and stages of development, 25-28 ; geologic problems. 75-276 ; general position of aqueduct line, 77-80 : location map, 80. Catskill Monadnock group, 73. ( ai skill supply, area in square miles, 11: daily supply in gallons, 11; estimated daily supply, 11; estimated cost, 1 1 : storage in gallons, 11 ; part of supply available by 79/?, 15. Cross sections, Rondout valley, 140. Croton aqueduct, study of shaft 13 and vicinity, 209-14; comparison of Bryn Mawr and shaft 13, 21214; map showing location, 239. Fordham gneiss, 47, 52, 57, 62, 185, 191, 192, 202, 206, 217, 218, 219, 220, 221, 225, 226, 232, 233, 234, 237. 238. 255, 257, 258, 260, 261, 262, 264, 265, 266, 268. Geology of region, 29-74 ! summary of formations, 54-57; outline of history, 62-65 > local summary, 26566. Hornblendic gneiss, 263. Hudson river, 69; water to be used for lire protection, 10; wash borings, 26; depth of buried channel, 89; submarine channel, 90-91; profile, 91-95; origin of the present course, 95-96; crossing, geological conditions affecting, 97-107 ; outline map showing possible crossings, 98; difference of structure in crossings, 104; postglacial faulting of district, 272. Hudson river canyon, 81-96; points of exploration, 83-88; comparative sections at Peggs point and Storm King, 92: study of profile, 94. Inwood limestone, 47, 49-50, 56, 172, 185, 191, 192, 201, 202, 210, 212, 217, 218, 219, 220, 221, 226, 232, 237, 238, 240, 242, 243. 245, 246, 249, 254, 255, 256, 261, 262, 255, 268, 269. Liberty ville, 149, 150. Limestones, 99, 100, 176; resistance to solution, 139; analysis of, 139; of Sprout Brook valley, 171 ; interbedded, older than the Inwood, 266-70. 183. 186, 191, 192, 201, 217, 218. 219, 220, 221, 225, 226, 233, 234, 237. 238, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 254, 257, 261, 265, 268, 269. New York city, gorge at, 91 ; sections of gorge at 32d street, 92; geological conditions affecting the location of delivery conduits, 21529; areal and structural geology south of 59th street. 231-36; structural geology of the lower East side, 253-66. Rondout valley section, 125-47; engineering problems, 17-19 ; geology, 31 ; special features, 137-40; analysis of limestones, 139; cross sections, 140. of Water Supply, 13. Shawangunk conglomerate, 45, 55, 63, 126, 127, 133, 135, 136, 149; thickness, 136; overthrust, 137. Stviiolina fissurella, 38. Surface configuration, history of, 66. Swift, William E., acknowledgments to, 6; division engineer, 21, 83, 163. Woodworth. mentioned, 276. Yonkers gneiss, igr, 106, 197, 198, 202, 217, 218, 219, 220, 221, 225, 226; of superior durability, 200.	98,708	common-pile/pre_1929_books_filtered	geologyofnewyork00berk	public_library	public_library_1929_dolma-0000.json.gz:1640	https://archive.org/download/geologyofnewyork00berk/geologyofnewyork00berk_djvu.txt
KRR275dwuR3vHEu6	Doing Research	4 A Note about Wikipedia Wikipedia is a popular place to start your research and will likely be one of the top results in a Google search of your topic. A well-developed Wikipedia article, with its content boxes and overviews, will provide a “road-map” of your subject and help you to focus on related and narrower sub-topics. Most introductory paragraphs will offer definitions, related terms, and key historical dates where relevant. Every article provides links to external references and further reading that can be useful sources for you to follow up with. In fact, no Wikipedia article can be published unless it is backed with a list of credible sources. See Wikipedia’s own policy on Verifiability and its discussion of what can be considered a reliable source. However, while it is not quite true that anyone can edit a Wikipedia article, there are concerns about the potential for inaccuracies and misinformation. This is especially true for controversial topics; a quick look at the “Talk” page of any article will reveal how editors are actively involved to ensure that information presented is free from bias and maintains a neutral point of view. Unlike more traditional scholarly sources of information, content on Wikipedia is continually changing. For these reasons, your instructors may caution you against using it in your research, and will probably discourage you from citing it. What you can do with a Wikipedia article is look at the external links, the supporting references, and the suggestions for further reading. As someone new to a topic, these sources can be a goldmine; try locating them in the library’s collection or on the internet. Activity: Watch, think and learn The following short video from Civic Online Reasoning at Stanford University demonstrates how Wikipedia can be used effectively in early stages of your research. Source Image: “Old version of Wikipedia logo” by Wikimedia Commons is licensed under a CC BY-SA 3.0. Verifiability and Neutral Point of View from Wikipedia the Free Encyclopedia is licensed under CC BY-SA. Video: “How to Use Wikipedia Wisely” by Civic Online Reasoning is licensed under CC BY-NC-NC 4.0.	455	common-pile/pressbooks_filtered	https://kpu.pressbooks.pub/doingresearch/chapter/a-note-about-wikipedia/	pressbooks	pressbooks-0000.json.gz:1586	https://kpu.pressbooks.pub/doingresearch/chapter/a-note-about-wikipedia/
nwQkJ_C8TmASn1EO	Proceedings of the 15th International Conference on Industrial Engineering and Industrial Management and XXV Congreso de Ingeniería de Organización	Jon Borregan-Alvarado1, Izaskun Alvarez-Meaza1, Ernesto Cilleruelo-Carrasco1 and Gaizka Garechana-Anacabe1 1 Business Organization Dept. University of the Basque Country UPV/EHU. Ingeniero Torres Quevedo Square, 1, 48013 Bilbao (Spain) Keywords: Collaborative Robots, Cobots, Patent Analysis, Network Analysis. 1. Introduction The Industry 4.0 (I4.0) concept, together with the implementation of relevant emerging technologies, i.e. areas such as Artificial Intelligence (AI), automation and robotics, or Human-Machine Interaction (HMI) [1], have originated the technological enabler known as collaborative robots [2] or cobots. This collaboration between robots and humans is one of the main technologies of I4.0, which duly combines human skills with the strengths of intelligent machines [3], gaining in productivity and efficiency [4], greater flexibility for future process changes, guaranteed safety or increased accuracy. 2. Objectives The main objective is to define and map the technological profile of collaborative robots, analyzing the evolution of the creation of inventions, inventive performance, and the main technological fields. A network analysis will allow us to map the most important collaborations and to identify those patent assignees that focus their development on technology linked to climate change mitigation. 3. Methodology The objective will be achieved in three stages, the first stage being a comprehensive analysis of collaborative robots in the Scopus database and corroboration by experts in the field. This query has been adapted to a worldwide patent database PatSeer, that covers patent activity in 121 countries [5]. In the second stage, the retrieved data will be cleaned up and then analyzed using a combination of statistics, and finally in the third stage we will generate a series of networks that will allow us to identify the relationships between assignees and technological fields. 4. Results The number of Patent Families (PF) remains practically constant from 2001 to 2011, and only starts to grow from 2011 onwards, with China developing more than half of the inventions, followed by the United States (US), Germany, South Korea and Japan. As for the inventors, or who is creating the inventions, the most productive are exclusively related to Chinese universities and research centers, and companies noted for patent generation. The main assignees or beneficiaries of patents are the Japanese company Fanuc Corporation and the German company Kuka Systems GmbH. The most common Cooperative Patent Classification (CPC) observed is code B25J, [“performing operations; transportation (B): hand tools; portable power-driven tools; manipulators (25): chambers (J)”], with the subclasses related to this code being the main technological fields of inventions, together with CPC G05B [“physics (G): controlling; regulating (05): functional elements; monitoring or testing arrangements for such systems or elements (B)”]. Finally, it is observed that there are several companies and universities working on CPCs (and their corresponding sub-areas) related to “climate change mitigation technologies in the production or processing of goods” (Y02P) and “information or communication technologies that have an impact on other technological areas” (Y04), also noting that a small number of sub-areas concerning Y02P and Y04 are worked exclusively by a single company. 5. Conclusion The research carried out in this paper allows us to observe the exponential growth of patents on collaborative robots as a consequence of the fourth industrial revolution. On the one hand, Chinese organizations tend to protect their patents exclusively in China, while the rest of the major companies protect their patents in different countries, as a result of having headquarters in other countries or continents. On the other hand, the specialization of the main assignees of patents is linked to robotics and industrial automation applied to manufacturing and the automotive industry. In reference to technological fields, the main fields refer to technology related to hand tools or manipulators, with emphasis also on human-robot coexistence. Having said this, it can be concluded that this is a very active field of research, which opens doors to new in-depth research in this area, as in the field related to climate change mitigation, thus generating and conveying greater knowledge for the scientific community analyzing the scientific works related to these patents. References - Chen, Q.; Heydari, B.; Moghaddam, M. Leveraging Task Modularity in Reinforcement Learning for Adaptable Industry 4.0 Automation. J. Mech. Des. 2021, 143, 071701, doi:10.1115/1.4049531. - Jimeno-Morenilla, A.; Azariadis, P.; Molina-Carmona, R.; Kyratzi, S.; Moulianitis, V. Technology Enablers for the Implementation of Industry 4.0 to Traditional Manufacturing Sectors: A Review. Comput. Ind. 2021, 125, 103390, doi:10.1016/j.compind.2020.103390. - Gualtieri, L.; Rauch, E.; Vidoni, R. Emerging Research Fields in Safety and Ergonomics in Industrial Collaborative Robotics: A Systematic Literature Review. Robot. Comput.-Integr. Manuf. 2021, 67, 101998, doi:10.1016/j.rcim.2020.101998. - Vido, M.; Scur, G.; Massote, A.A.; Lima, F. The Impact of the Collaborative Robot on Competitive Priorities: Case Study of an Automotive Supplier. Gest. Produção 2020, 27, e5358, doi:10.1590/0104-530×5358-20. - Faculty of Economics and Business, University of Zagreb, J. F. Kennedy 6, 10 000 Zagreb, Croatia; Pejić Bach, M.; Pivar, J.; Faculty of Economics and Business, University of Zagreb, J. F. Kennedy 6, 10 000 Zagreb, Croatia; Dumičić, K.; Faculty of Economics and Business, University of Zagreb, J. F. Kennedy 6, 10 000 Zagreb, Croatia Data Anonymization Patent Landscape. Croat. Oper. Res. Rev. 2017, 8, 265–281, doi:10.17535/crorr.2017.0017.	1,095	common-pile/pressbooks_filtered	https://pressbooks.pub/cioxxv/chapter/mapping-the-technological-profile-of-collaborative-robots-a-patent-analysis-60/	pressbooks	pressbooks-0000.json.gz:85756	https://pressbooks.pub/cioxxv/chapter/mapping-the-technological-profile-of-collaborative-robots-a-patent-analysis-60/
0Dd6mShHEDbFBXCi	30.2A: Stages of Bone Development	30.2A: Stages of Bone Development Although bone initially forms during fetal development, it undergoes secondary ossification after birth and is remodeled throughout life. - Describe the process and purpose of bone remodeling Key Points - The formation of bone during the fetal stage of development occurs by two processes: intramembranous ossification and endochondral ossification. - Secondary ossification occurs after birth and forms the epiphyses of long bones and the extremities of irregular and flat bones. - After initial bone development, bones are remodeled throughout life to regulate calcium homeostasis and repair micro-damaged bones (from everyday stress ), as well as to shape the skeleton during growth. Key Terms - diaphysis : The central shaft of any long bone. - epiphyses : The rounded ends of a long bone at its joint with adjacent bone(s). EXAMPLES When a tooth is lost and not replaced, bone remodeling will fill in much of the socket. Although the remodeling will be obvious within a few weeks (especially when smiling), the process will continue for some months. Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support and protect the various organs of the body, produce red and white blood cells, and store minerals. Bone tissue is a type of dense connective tissue that appears static, but is actually constantly remodeled throughout the life of the vertebrate organism. This occurs with the synchronized action of osteoclasts and osteoblasts, cells that reabsorb and deposit bone, respectively. Bone remodeling also occurs in response to trauma, such as following an accidental fracture or placement of dental implants. Initial Bone Formation The formation of bone during the fetal stage of development occurs by two processes: intramembranous ossification and endochondral ossification. Intramembranous Ossification Intramembranous ossification mainly occurs during the formation of the flat bones of the skull, as well as the mandible, maxilla, and clavicles. The bone is formed from connective tissue such as mesenchyme tissue rather than from cartilage. The steps in intramembranous ossification are: - Development of ossification center - Calcification - Formation of trabeculae - Development of periosteum Endochondral Ossification Endochondral ossification begins with points in the cartilage called “primary ossification centers.” They mostly appear during fetal development, though a few short bones begin their primary ossification after birth. These cartilage poitns are responsible for the formation of the diaphyses of long bones, short bones, and certain parts of irregular bones. Secondary ossification occurs after birth and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphysis and both epiphyses of a long bone are separated by a growing zone of cartilage (the epiphyseal plate). When the child reaches skeletal maturity (18 to 25 years of age), all cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure). Remodeling Remodeling or bone turnover is the process of resorption followed by replacement of bone with little change in shape, and occurs throughout a person’s life, long beyond the initial development of bone. Osteoblasts and osteoclasts, coupled together via paracrine cell signalling, are referred to as a bone remodeling unit. Approximately 10% of the skeletal mass of an adult is remodeled each year. The bone remodeling period consists of the duration of the resorption, the osteoclastic reversal (the phase marked by shifting of resorption processes into formative processes), and the formation periods of bone growth and development. The bone remodeling period refers to the average total duration of a single cycle of bone remodeling at any point on a bone surface. The purpose of remodeling is to regulate calcium homeostasis and repair micro-damage from everyday stress, as well as to shape the skeleton during growth. Repeated stress, such as weight-bearing exercise or bone healing, results in the bone thickening at the points of maximum stress (Wolff’s law). Osteoclasts and Osteoblasts : Bone tissue is removed by osteoclasts, and then new bone tissue is formed by osteoblasts. Both processes utilize cytokine (TGF-β, IGF) signalling.	855	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/30%3A_APPENDIX_B%3A_Development_and_Aging_of_the_Organ_Systems/30.2%3A_Bone_Development/30.2A%3A_Stages_of_Bone_Development	libretexts	libretexts-0000.json.gz:46144	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/30%3A_APPENDIX_B%3A_Development_and_Aging_of_the_Organ_Systems/30.2%3A_Bone_Development/30.2A%3A_Stages_of_Bone_Development
r0rkzMzwS1DZkusp	Applied anatomy; the construction of the human body considered in relation to its functions; diseases and injuries, by Gwilym G. Davis. With six hundred and thirty-one illustrations, mostly from original dissections and many in color, by Erwin F. Faber.	PROFESSOR OF ORTHOPEDIC SURGERY AND FORMERLY ASSOCIATE PROFESSOR OF APPLIED ANATOMY IN THE UNIVERSITY OF PENNSYLVANIA ; CONSULTING SURGEON TO ST. JOSEPH'S HOSPITAL ; FORMERLY SURGEON TO THE EPISCOPAL HOSPITAL ; SURGEON TO THE ORTHOPEDIC HOSPITAL ; ORTHOPEDIC SURGEON TO THE UNIVERSITY AND PHILADELPHIA GENERAL HOSPITALS ; FELLOW OF THE AMERICAN SURGICAL ASSOCIATION, THE PHILADELPHIA ACADEMY OF SURGERY AND PHILADELPHIA COLLEGE OF PHYSICIANS ; MEMBER OF THE AMERICAN SOCIETY OF CLINICAL SURGERY, THE AMERICAN ORTHOPEDIC ASSOCIATION, AMERICAN ACADEMY OF MEDICINE, ETC. PREFACE TO SECOND EDITION. In this edition the general plan of the work has been retained. The text and illustrations have been carefully revised with many corrections and additions. The cuts have been made more accurate, ten have been entirely replaced and two new ones added. Our thanks are extended to our kindly critics who have aided us in making the book more accurate and useful. It is not the object of this work to teach plain anatomical facts ; its aim is to show the relation of structure to function, whether it is normal function or function disturbed or impaired by injury or disease. It is explanatory and utilitarian in character, and not encyclopedic. The bare facts of anatomy can be obtained from, the systematic treatises, and they are here only briefly given in order to refresh the memory of the reader, who is supposed to be familiar to a certain extent with systematic anatomy. A person who has studied the subject only from a systematic standpoint cannot utilize and apply the knowledge so acquired unless he considers its relation to the various affections encountered in practice. He can study anatomy, but he will not see its application until it is pointed out to him. He may have studied the palmar fascia, but, unless he is shown how its construction influences the course of pus originatmg beneath it, his anatomical knowledge is of little ^•alue. The inability to make any practical use of the facts or to see their application is the reason why anatomy is so frequently regarded as a dry, uninteresting study and too often designedly neglected. In considering the subject, after a few general remarks on the part involved, the skeleton and muscles are briefly described, and thereby one is enabled to understand the surface anatomy, which immediately follows. Then comes a consideration of the various affections of the part, with such allusion to the ner\-es and vessels as is desirable to elucidate the subject. As the book is not intended to be a systematic treatise on anatomy, such anatomical facts as cannot be shown to be useful in practice are not mentioned. To give them here would make the volume too large, obscure its main object, and defeat its purpose. As regards the anatomical nomenclature used, there is no system so generally accepted as to justify its exclusive adoption. In the desire, however, to aid in furthering the adoption of better anatomical terms, as much of the BNA terminology has been used, or included in parentheses, as a consideration of the subject from the standpoint of a general practitioner would allow. Most of the illustrations are from original drawings of preparations made by the author and his assistants. Those derived from other sources are duly credited ; if there has been any failure in this respect, it is unintentional. experience. To the artist in charge, Mr. Erwin F. Faber, and to Mr. Herman Faber, who made a large number of the original sketches, my best thanks are due for their great skill, untiring energy, and most intelligent aid ; their work speaks for itself. vi PREFACE. I am under great obligations to many friends who have kindly rendered me their aid. Professor George A. Piersol has given me much valuable information and allowed me the unstinted use of his anatomical material ; Dr. Astley P. C. Ashhurst made many of the dissections and aided in correcting and preparing the manuscript for the press ; Dr. Frank D. Dickson did most of the proof-reading and prepared the index ; Dr. T. Turner Thomas made many of the earlier preparations ; and Dr. Henry Beates aided in the revision of the first portion of the manuscript. To these and others who have contributed to the formation of the book I desire to express my thanks. To the hearty cooperation and unfailing generosity of my publishers is due the presentation of such an attractive volume. I asked them for nearly everything I could think of, and they gave me nearly everything I asked for. In conclusion : this work is recognized as being far from complete, but it is intended to be suggesti\'e rather than absolute. It is not designed so much to present facts as to furnish reasons, and it is hoped that it will appeal to the practising physician and surgeon as well as to the student. Centre or Broca's Convolution; Postfrontal Area; Rolandic Area; Sensory Area; Visual Area; Auditory Area; THE SCALP. The scalp is formed by the movable soft tissues which cover the skull. It is composed of three layers: skin, superficial fascia, 2ir\d occipitofrontalis rn7iscle with. its aponeurosis. It is attached to the underlying pericranium by loose connective tissue called the subaponeiirotic layer. The pericranium, or periosteum of the skull, is loosely attached to the bones by a small quantity of connective-tissue fibres called is very firmly attached. The principal affections of the scalp are wounds, inflammation, affections of the blood-vessels, tumors, and neuralgia. The peculiarities of these affections are determined by the anatomical structure of the parts. The skin of the scalp is probably the thickest in the body, although not so dense as that of the heel. Besides the hair, it contains abundant sweat and sebaceous glands. These latter are connected with the hair-follicles and are near the surface. The skin increases in thickness from the frontal to the occipital region. The superficial fascia consists of a net-work of connective-tissue fibres which run from the skin aboxe to the aponeurosis of the occipitofrontalis below. In its meshes are fat, blood-vessels, nerves, and lymphatics. The hair-bulbs often pierce the skin and extend into this laver. 2 APPLIED ANATOMY. arrangement of the fibres is shown in Fig. 3. Fibres starting from the point A not only pass directly down to B, but also to each side to the points Cand £>. In the same way, fibres starting from B not only pass upward to A, but also forward to £ and backward to F. Now. if the skin is mo\ed in the direction of the forward arro\y, the fibres £ B and A D are tightened and drag the aponeurosis forward. If the skin is moved in the direction of the backward arrow, the fibres A C and FB are tightened and so drag the aponeurosis backward. Thus it is seen that the aponeurosis must follow the movements of the skin. Merkel describes the epicranial aponeurosis as di\'iding into two layers, one inserting into the skin and the other into the rim of the orbit {Hand, der top. Anat. Bd. i, p. 17). The bellies of the muscle are comparatively short, about 5 cm. in length, the remaining tissue extending between them constituting the aponeurosis. As it comes downward from the temporal ridge, over the sides of the head, the aponeurosis becomes thinner and gives attachment by its superficial surface to the anterior and superior attricii/ar muscles. It then proceeds downward to be attached to the upper edge of the zygoma. the sutures. Contraction of the occipitofrontalis muscle causes the skin of the forehead to wrinkle transversely. It is a muscle of e.xpression, and blends with the pyrajnidalis nasi and corriigator siipercilii. It is supplied by branches of the facial ner\e. The subaponeurotic tissue is very loose and abundant, so that it does not tend to confine the movements of the scalp, but fax'ors them. Hence the scalp is readily torn loose from the skull in scalj)ing, machinery accidents, etc. This tissue is so loose that effusions accumulate here and spread extensivelv. It contains only a few blood-vessels. The pericranium in its normal condition is a thin, tou^h membrane containing few blood-vessels. Except at the sutures, where it is firmlv attached and dips down between the bones, it is comparatively easily stripped from the skull and does not convey much nourishment to it. It is deticient in osteogenetic or boneforming properties, so that when it is raised off the skull in operations, and the bone removed from beneath, as occurs in trephining, fractures, etc., new bone is not produced. its anterior and posterior branches ; and by the posterior auricular and the occipital arteries from the external carotid. These arteries communicate freely M"ith each other, not only laterally, but also across the top of the scalp. It is not unusual to see a large branch of the temporal communicating directly with the occipital. The temporal artery begins in the substance of \S\& parotid glajid, just below the condyle of the jaw, and mounts over the zvgoma, a centimetre (or less) in front of the ear. It lies on the temporal fascia and its pulsations can be felt at this point, if desired, during the administration of an anaesthetic. About four centimetres ( i ^2 in. ) above the zygoma, it di^-ide3 into the anterior and posterior branches. The auriculotemporal branch of the fifth nerve lies just in front of the ear and between it and the temporal arterv. The occipital artery mounts to the scalp in the interval between the posterior border of the sternomastoid muscle and the anterior border of the trapezius. It is about midway between the posterior border of the mastoid process and the occipital protuberance. If it is desired to expose it from this point forward, the LYMPHATICS OF THE SCALP. The lymphatics anteriorly near the median line pass down between the orbits to reach the submaxillary nodes. Those of the anterior parietal and temporal regions empty into the pre-auricular nodes; those of the posterior parietal and temporal, into the nodes behind and below the ear; and those of the occipital region into the occipital nodes. Infectious troubles of these regions, therefore, will cause enlargement of the corresponding nodes. AFFECTIONS INVOLVING THE LAYERS OF THE SCALP. Wounds of the scalp are common. Incised wounds bleed more freely and the hemorrhage is more difficult to control than in wounds elsewhere on the surface. This is due to the exceedingly free blood supply and to the peculiar arrangement of the blood-vessels in the tissues. Small wounds of the scalp do not gape, particularly if they are longitudinal in direction and not very deep. The skin is so intimately bound to the aponeurosis beneath that displacement is impossible. If the cut is deep enough to divide the aponeurosis extensively, especially if the wound is transverse, gaping is marked. This is produced by contraction of the two bellies of the occipitofrontalis muscle, which pulls the edges apart. Bleeding is apt to be persistent and hard to control because the arteries running in the deep layers of the skin and fibrous trabeculse are firmly attached and, therefore, when cut, their lumen cannot contract nor their ends retract. When large flaps are torn in the scalp, they rarely die because of their free blood supply, and sloughing is limited to the parts which are actually contused. As the subaponeurotic space is often opened, if the wound is sewed too tightly shut, subsequent bleeding instead of escaping externally may extend widely under the aponeurosis. Inasmuch as hair and dirt are often crushed into these wounds, great cdre should be taken to wounds. To avoid this the scalp is covered by a recurrent bandage or otherwise fixed. Lacerated wounds do not bleed so freely as do incised wounds, but they are accompanied by a more extensive loosening of the scalp. Large flaps of tissue are frequently raised and turned to one side. The most severe of these injuries have been produced by the hair being caught by a revolving shaft, tearing nearly the : whole scalp off. Its loose attachment to the pericranium and bone beneath by the loose subaponeurotic tissue, readily explains the reason of these extensive detachments. Contusions cause only a moderate amount of swelling, which is usually circumscribed. While the skin is not broken, the blood-vessels and other tissues beneath are often ruptured, and, therefore, extravasation of blood occurs. When this is confined to the superficial fascia, it is small in amount and limited in area. It does not tend to work its way for any great distance beneath the skin. If the extravasation extends below the aponeurosis, it may cover a considerable area of the skull. When it occurs beneath the pericranium it is called cephalhcsniatotna, or in the new-born caput succedanetcm. Caput succedaneum is found almost always on the right side, involving the parietal eminence. It is limited by the attachment of the pericranium at the sutures. HcEmatomas of the scalp possess the peculiarity of being soft in the centre and surrounded by a hard oedematous ring of tissue. In cephalhaematoma of long standing this ring may ossify, and the new bone may even extend and form a more or less perfect bony cyst. This, however, is very rare. Haematomas produced by blows on the head are often mistaken for fractures. The raised edge is so hard as sometimes to be thought to be the edge of broken bone. The tissues beneath the skin at the site of impact seem to be pulpified and remain perfectly soft to the touch; the smooth unbroken skull can usually be felt over an area equal to the site of impact. Surrounding this soft area is the hardened ring, composed of tissues between the skin and the bone, into which serum and blood have been effused. 3. Subpericranial. I. Subcutaneous abscesses are usually small and do not tend to spread but rather to discharge through the skin. This is because the firm fibrous trabeculae prevent lateral extension. Furuncles are quite common in childhood; they are, of course, superficial to the aponeurosis. Sebaceous cysts are especially common in the scalp and they sometimes suppurate. The orifice of the obstructed duct is not usually visible. Sometimes in a small cyst a black spot on its surface indicates the opening of the duct. By means of a needle or pin this opening can be dilated and some of the contents expressed. Of course, if nothing further is done it will reaccumulate. When these cysts become inflamed they become united to the skin above so that it has to be dissected ofT. If pus forms, it either remains localized to the cyst or bursts through the skin and discharges externally. It does not tend to burrow under the skin laterally on account of the fibrous trabeculre uniting the otherwise it will recur. 2. Subaponeurotic abscesses come from infected wounds, erysipelas, or caries of the bones. It is not desirable to close deep wounds of the scalp too tightly. Some suppuration is liable to occur which, not finding an easy escape externally, may spread under the aponeurosis if the wound has been deep enough to di\'ide_ it. Infection of wounds is the most frequent source of these abscesses, hence the desirability of providing for drainage for at least a short period. In erysipelas, serous effusion, which may become purulent, occurs in the subaponeurotic tissue, as well as in the layers above. It may sink downward and point in the temporal, occipital, or frontal region. In the temporal region the descent of the pus may be limited by the attachment of the lateral expansion of the aponeurosis to the zygoma. The attachment of the occipitalis muscle posteriorly to the superior curved line of the occiput prevents the effusion from coming to the surface at tliat point. The liquid accumulates low down on the forehead over the orbits, being prevented from entering bv the attachment of the orbitotarsal ligament^ and tends to point close to the median line. The frontal muscles of the two sides are apt to be slightly separated, leaving a weak spot just abo\e the root of the nose, and this is where fluctuation can most easily be felt. These accumulations in the frontal, temporal, and occipital regions may require incisions for their evacuation and drainage. Suppuration arising from carious bone readily perforates the pericranium and then infiltrates the loose subaponeurotic tissue. The bones of the vault of the skull are not infrequently afi'ected by syphilitic disease, producing caries and suppuration, which invade the subaponeurotic space. 3. Subpericranial abscesses are comparatively rare. They usually start from diseased bone and spread laterally beneath the pericranial tissue. The pus may be limited to a single bone on account of the firmer attachment of the pericranium at the site of the sutures. To avoid breaking into the subaponeurotic space, a free opening should be made into the abscess so as to allow the pus to drain externally. The arteries or veins alone may be affected, or both may be involved. Arterial varix is the name given to an enlargement of a single artery. It forms a swollen, tortuous, pulsating mass in the course of the artery. The temporal artery is liable to be so affected, particularly its anterior branch. Cirsoid aneurism^ or aneurism by anastomosis, is formed bv numerous enlarged arteries. It is sometimes called an arterial angioma ox plexiform angio^na. The veins are also somewhat involved. Pulsation is marked. Varicose aneurism is where a sac intervenes between the artery and vein, so that the blood passes first from the artery into the sac and then into the vein. The temporal artery with its companion vein has been so affected. Treatment of Vascular Affections of the Scalp.— Vascular tumors are usually ligated and excised. Acupressure pins may be passed under the larger arterial trunks, but the exceedingly free anastomosis renders thorough excision preferable; even this is not seldom unsuccessful. TUMORS OF THE SCALP. Sebaceous cysts arise from obstructed sebaceous glands; the contents consists of epithelial cells, fat, and cholesterin. They sometimes calcify. They spread in the subcutaneous tissue, stretching and raising the skin above and causing atrophy of the hair bulbs, but do not involve the epicranial aponeurosis below. In removing them, if they have never been inflamed, they can readily be turned out through a slit in the skin. The subaponeurotic space will not be opened, therefore their removal is not often followed by bad results. membranes of the brain, containing brain matter and cerebrospinal fluid. Meningocele, or a tumor containing the meninges of the brain and cerebrospinal fluid, is more rare in the skull than is the case when the spine is affected. It protrudes through an unossified part of the skull, and, according to Sutton, two-thirds of the cases occur in the occipital region, between the foramen magnum and torcular Herophili. He characterizes it as a hydrocele of the fourth ventricle, and says that nine out of ten cases die if operated on. The next most frequent seat for meningocele is at the root of the nose (Fig. 10}. interior of the skull through a traumatic opening. It contains cerebrospinal fluid. Dermoid tumors occur in the median line and, according to Sutton, are most common over the anterior fontanelle and external occipital protuberance. They often have a thin pedicle attaching them to the dura mater and may grow either inside or outside the skull. They are formed by an inclusion of some of the tissue of the ectoderm by the bones as they approach from each side to ossify and unite in the median line. A congenital tumor located at the root of the nose is probably an encephalocele; one located at the anterior fontanelle is probably a dermoid; a tumor in the occipital region may be either, but a dermoid is apt to be higher up than an encephalocele. The hyoid bone is usually classified with the bones forming the brain case. They are the two temporals, the sphenoid, and the ethmoid. urteen in number, there being two single bones the mayidiblc, or inferior maxilla, and vomer ; malar, nasal, palate, lachrymal, and inferior The skull of the infant is markedly different from that of the adult. The frontal and parietal eminences are A'ery marked. The vault of the skull is not entirely ossified and the sutures are not completed. The bones of the base of the skull originate in cartilage, while those of the vault originate in membrane. This membrane has one or more centres of ossification appearing in it for each bone. These centres increase in size and finally meet at the edges of the bone, thus forming the sutures. At the time of birth the sutures are represented by membrane, which joins the adjacent bony edges. The frontal bone has two centres of ossification; one for each side. These form a suture in the median line of the forehead w!" ' -h becomes obliterated in the course of the first or second year. Traces of it in the shape of a groove or ridge can sometimes be seen or felt in the adult skull. The frontal eminences are far more marked in childhood than later in life and give to children the prominent forehead which is so characteristic. A similar peculiarity is seen in the parietal bones, the parietal eminences being quite prominent. On this account, they are often injured in childbirth, sometimes being compressed by the obstetrical forceps, and are frequently the seat of hconatoma neonatorum. The cranial bones not being firmly united allow of a certain amount of play or even overlapping, thus facilitating the delivery of the head at birth. Fontanelles. — At the juncture of the various bones are six spaces called fontanelles. Two, the anterior and posterior, are in the median line of the cranium, and four, the two anterolateral and two posterolateral, are at the sides. The fontanelles are situated at the four corners of the parietal bones. The anterior fonta7ielle is the largest. It is diamond-shaped and formed by the frontal suture in front, the interparietal behind, and the coronal at each side. It is usually closed by the ^wd. of the second year, but may be delayed until the fourthJ^^VIn rickets and malnutrition the fontanelles remain open longer than would otherwise be the case.' The posterior fontanelle is formed by the juncture of the parietal (sagittal) suture with the lambdoidal suture. It is triangular in shape with the apex forward between the two parietal bones, the sides passing down, one to the right and the other to the left of the top of the occijiital bone. lateral fonlanelles. These fontanelles are of the greatest importance in diagnosing the position of the head during labor. If the examining finger encounters first a large diamondshaped or four-cornered depression with its anterior angle more acute than the posterior, the accoucheur will know that it is the anterior fontanelle which is presenting. By following one of the sutures backward he will come to a triangular or Y-shaped ridge which will be recognized from its shape as being the posterior fontanelle. He will then know that the position of the one, the finger will first encounter the posterior fontanellewiih its three sutures, which are distinctly recognizable. On following the suture which leads backward, the four-cornered anterior fontanelle will be felt. The various sutures constituting the fontanelles can usually be distinctly felt, and, as the presentations are nearly always occipito-anterior, the fontanelle that will usually be first felt will be the posterior, and the sutures forming it can readily be counted. The antero- 2.w<\ posterolateral fontanelles, located at the anterior and posterior angles of the parietal bones, are of no service in diagnosing the position of the head. They are indistinct, nearly closed, and thickly covered by tissue. In injuries to the skull in young children and infants, we should not mistake the fontanelles and lines of the sutures for fractures. Fissures extending into the occipital bone from the posterolateral fontanelles are normal at birth and not due to injury. of the face so slightly developed that there is no room for the ca\"ities which afterward develop in them. The ridges of the bones also become more marked as age advances. The young child has no superciliary ridges. The maxillary sinus, or antricfn of Highmore, and the mastoid antj'imi are the only cavities that exist at birth. They are both much smaller than they ultimately become. The mastoid antrum in relation to the size and age of the child is comparatively large, being about fi\'e millimetres in diameter. As the bone in the child is undeveloped, and the tympanum lies nearer to the surface, the antrum likewise is somewhat higher and nearer to the surface than is the case in adults. This should be borne in mind when operating on the bone in this region (Fig. 13). the vault. The bony prominences become marked, due to the action of the various muscles of mastication, expression, etc., inserted into them. The face is much larger in size in proportion to the calvarium than was the case in infancy. While in infancy bone is practically homogeneous, in late childhood and early adult life cavities begin to develop in it. Outer and inner tables of compact tissue are formed, separated by diploic structure. The frontal, ethmoidal, and other air-sinuses are an exaggeration of these diploic spaces. They are lined with mucous membrane and communicate with the nasopharynx. The diploe first begins to appear about the age of THE SKULL. ii they are well developed. They may extend well out over the orbits, reaching to within a short distance of the temporal ridge, while in other instances they do not go beyond the supra-orbital notches. In height they may reach the lower portion of the frontal eminences or may cease at the level of the superciliary ridges. The size of the sinus cannot be judged from the size of the bony prominences. Neither is the size nor sex of the individual any criterion. In a small female we have seen them of considerable size. When diseased sufhciently to give rise to symptoms, they will be found to be quite large. They are separated from each other by a septum, and if extensive are divided into several pockets or recesses. They open into the infundib- involving the inner table. Mastoid Process. — -The mastoid process is continous with the superior curved line of the occiput. It increases in size from the time of birth, but is composed of cancellous tissue until after the age of pubertv, when the mastoid cells develop. The mastoid antrum, a cavity five millimetres in size at birth, which opens into the upper posterior portion of the tympanum, is relatively larger at birth than in the adult. veins run from the antrum into the lateral sinus. Suprameatal Triangle.— This triangle, so named by Macewen, is formed above by the posterior ro(jt of the zygoma, anteriorly by the bony posterior wall of the external auditory meatus and posteriorly by a line from the floor of the meatus passing upward and backward to meet the first line. The mastoid antrum is reached by operating through this triangle (see section on Ear J . Cerebral Venous Sinuses. — The fibrous membrane which lines the interior of the skull is composed of two layers which are in most places intimately united, forming one single membrane known as the dura mater. The outer layer is applied to the bone, while the inner layer covers the bram. In certam places these two layers separate to form channels in which venous blood flows ; these channels are called sinuses. In certain other places these layers separate and enclose some special structure, as the Gasserian ganglion. to the median line and external occipital protuberance. ward it inclines more to the right side, so that at the torcular Herophili the left side of the sinus is about in the median line. This sinus receives the veins from the cortex of the brain and also some from the diploe of the bones above it. A vein pierces the upper posterior angle of each parietal bone and forms a communication between the superficial veins of the scalp outside and the superior longitudinal sinus within. The deviation of the superior longitudinal sinus toward the right, as it proceeds posteriorly, is to be borne in mind in operating in this region, as one can approach the median line nearer on the left side posteriorly than the right, without wounding it. In the parietal region the Pacchionian bodies are surrounded by extensions from the longitudinal sinus and free hemorrhage will ensue if the bone is removed too close to the median line. The torcular Herophili, or confluence of the sinuses, does not correspond exactly to the external occipital protuberance or inion on the exterior of the skull. It is a little above and to the right of it. This torcular Herophili is formed by the meeting of the longitudinal sinus from above, the lateral, or transverse sinuses from the sides, the straight sinus from in front and the occipital sinus from below. The lateral or transverse si?mses, of which there are two, pass from the torcular Herophili toward each side in the tentorium between the cerebrum and cerebellum, following the superior curved line of the occiput until just above the upper posterior portion of the mastoid process. They then bend downward to within a centimetre of the tip of the process and again cur\-e forward to end in the jugular foramen and be continued as the internal jugular vein. The S-shaped curve which they make in this part of their course has given rise to the name sigmoid si?ms. In ics course along the superior curved line the sinus rises above the level of a line drawn from the inion to the centre of the external auditory meatus. In operating for cerebellar abscess, care should be taken to place the trephine opening sufficiently low down to avoid wounding this sinus. It is in o-reat dano-er of being wounded in operating for septic conditions involving the mastoid antrum and cells. Its distance from the surface of the skull varies in different individuals, and it gets farther from it as it descends to the level of the tip of the mastoid process. It receives the blood from the posterior lower portion of the cerebrum and upper portion of the cerebellum, and communicates with the veins outside the skull through the mastoid and posterior condyloid foramina. Running along the upper posterior edge of the petrous portion of the temporal bone, in the attachment of the tentorium, is the superior petrosal sinus, it connects the lateral or transverse sinus about its middle with the cavernous sinus. More deeply situated, and running from the cavernous sinus to the lateral sinus, just as it enters the jugular foramen, is the inferior petrosal simcs. The petrosal and lateral sinuses are frequently torn in fractures of the skull. A fracture passing through the petrous portion of the temporal bone may tear the petrosal sinuses, and hemorrhage from the ear might come from this source. A fracture through the posterior cerebral fossa may tear the lateral sinus. Leeches are sometimes applied behind the ear in inflammation of the brain, with the idea of drawing blood from the lateral sinus through the mastoid vein. the veins of Galen, and the blood from the falx through the inferior lo7igitudi)ial sinus. This latter is usually very small and sometimes almost lacking, the blood in that case passing upward to empty into the superior longitudinal sinus. The cavernous siniis,^o\\(t on each side. — is a large, irregular space on the side of the body of the sphenoid bone. It runs from the sphenoidal fissure in front to the apex of the petrous portion of the temporal bone behind. In front it is continuous with the ophthalmic vein, and recei-ves the sphenoparietal sinus which brings the blood from the diploe ; behind it communicates with the superior and inferior petrosal sinuses. The two sinuses communicate across the median line around the pituitary body, forming the circular sinus, and across the basilar process, forming what is sometimes called the transverse sinus, but which is more correctly described as a plexus of veins. The cavernous sinus has embedded in its outer wall the third and fourth nerves and the ophthalmic branch of the fifth. — Transverse section of the right cavernous sinus, showing the position of the nerves and internal carotid artery (from a dissection). nerve. Within the sinus and toward its lower and inner portion, is the internal carotid artery. It is surrounded by the blood-current. Between the carotid artery and outer wall of the sinus runs the sixth nerve, held in place by fine, trabecular, fibrous bands which pass from side to side in the cavity of the sinus. The cavernous sinuses are sometimes torn in fractures of the base of the skull, resulting in a traumatic communication between the carotid artery and the sinus. The cavernous sinus is not infrequently torn in attempting the removal of the Gasserian ganglion, particularly if its ophthalmic branch is attacked. Its interior is not one large cavity, but is subdivided by fibrous septa, which pass from side to side. It is sometimes the seat of thrombosis and infection, which may reach it through the ophthalmic vein in front. Fractures of the skull are almost always produced by violent contact of the skull with some solid body. In some cases the fracture is produced by a blow from a moving body, as when a person is struck by a club. In others, the skull is moving and strikes a body at rest, as when a person falls and strikes the head on a pavement. It is not necessary to discuss in detail the mechanism of fractures of the skull; it is sufficient to state that nearly all fractures start from the point of impact and radiate to distant regions. The effect of fracturing blows on the skull of a child is different from their effect on the skull of an adult. Fractures of the Skull in Children. — A child's skull is thin and weak, and while, to a certain extent, fragile is more flexible than that of an adult. It is on this account that blows are more liable to expend their force locally, at the point of impact, and not produce fractures at a distance. Therefore, it follows that fractures of the base are rare in children in comparison with fractures of the \'ault. Extensive fissured fractures are also rare. A marked example of this was seen in the case of a small boy who, while playing, was struck by a baseball on the left frontal eminence. A distinct circular depression or cup was produced exacdy corresponding to the shape of the ball. There were no symptoms of cerebral concussion, because the force of the blow was expended on the bone and not transmitted to the brain within. As pointed out by Mr. Rickman Godlee, the sutures in very young children being soft, the transmission of the force from one bone to another is prevented. The diploic structure of the skull is not well developed until adult age, therefore the bone is homogeneous. It is also elastic, and, particularly in infants, it may be dented without being seriously fractured; these dents are apt to disappear and become level with the surrounding bone as the child grows older. The dura mater is more adherent in children and fractures are, on that account, more liable to tear it and even lacerate the brain beneath. Fractures of the Skull in Adults. — As adult life is reached the inner and outer tables of the bones become separated, leaving the space between to be filled by the diploic tissue. The diploe consists of cancellous bone in the meshes of which run the diploic veins and capillaries. Both the inner and outer tables are brittle, but the inner especially so. It is also harder and more compact than the outer table. On account of this difference we find in cases of fracture that the inner table is more comminuted than the outer, so that, while the outer may show a single line of fracture, the inner table immediately beneath may be broken into several fragments. This is one reason why trephining is so frequently resorted to. during our Civil War. A soldier, while looking over a rampart, was struck a glancing blow by a bullet, on the upper anterior portion of the skull. The outer table at the site of injury was not at all depressed, but the inner table had a large piece broken off, which injured the membranes. The elasticity of the skull is shown in cases of fracture in which hairs are found imbedded in the line of fracture. Figure 21 is from such a case. A negro was struck on the head by a falling rock and an extensive longitudinal fracture was produced in which many hairs were fastened. About a centimetre from the main fracture was a small fissure, not over a centimetre long, and sprouting up out of it, like bushes from the bare ground, were a number of hairs. In such cases the hairs are carried into the line of fracture by the force of the blow; the elastic bone then springs back into place and pinches the hairs, thus holding them in place. The bones of the adult skull are very strong and firmly fi'xed. The sutures begin to unite at the age of forty years and are likely to have disappeared at the age of seventy. Even in young adults the fibrous tissue between the bones has so nearly disappeared that they practically act in transmitting force as one continuous bone. For these reasons slight blows do not cause fractures. It takes a very heavy blow usually to cause a fracture and the force is so great that shock or concussion of the brain with disturbance of its functions is a common symptom. The force of the blow is expended first at the point of impact, and if a fracture occurs it usually starts there. From that point it radiates to other portions of the skull, so that fractures of the vault frequently extend to the base. The course pursued by the fracture has been formulated into a law by Aran ; that they take a straight line from the point of impact on the vault to the base of the skull, and are not deflected by the sutures. Charles Phelps (" Traumatic Injuries of the Brain") found that in 127 cases of fracture of the base of the skull, 12 implicated the base only. So that, if we are able to say that there is a fracture of the base of the skull, there are over 10 chances to one of its extending up into the vault. In only two were the fractures more than a slight fissure ; so that in a marked fracture of the base there would be 63 chances to one of its extending into the vault. Also, from Aran's law, we see that, if we diagnose a fracture through the middle ear, we may be pret.y sure that the force was applied directly above, and be led to trephine accordingly. A man fell from an electric light pole and was brought to the hospital with bleeding from the ear and other symptoms of fracture of the skull. He became wildly delirious, and, feeling sure that the fracture of the base was an extension from the vault, although no depression could be felt, he was trephined above the external auditory meatus and a large epidural effusion of blood evacuated. He recovered and resumed his work. In this case, as soon as the bone was exposed, a thin line of fracture was seen running down to the base in the region of the external ear. Fractures by Contrecoup or Counter Stroke. — Fractures by counter stroke are now regarded as of much less frequent occurrence than formerly. Charles Phelps found in 147 cases of fracture of the base of the skull 12 which had not extended from the vault. In these, the force had been applied to the parietal region in six, and in five to the occiput; most of the resulting fractures were in the region sphenoidal cells and cause bleeding from the nose and mouth. A fracture through the roof of the orbit causes bleeding into the orbital cavity; the blood works its way forward and makes its appearance under the conjunctiva of the ball of the eye. Its progress forward toward the lids is blocked by the orbitotarsal ligaments, and it therefore works its way downward to the bulbar conjunctiva, under which it advances to the edge of the cornea. The ordinary ccchymosis of the lids and cellular tissue around the eye is usually due to a rupture of the vessels of the subcutaneous tissue by a blow from the outside, and not to a fracture of the base of the skull. Fracture through the middle cerebral fossa may pass through the body of the sphenoid or basilar process of the occipital bone and cause bleeding into the mouth. It may also cause an accumulation of blood behind the posterior wall of the pharynx^ pushing it forward. When it passes through the petrous portion of the temporal marked on the outer surface of the skull. of the pterlon. This point is the junction of the coronal and sphenoparietal sutures, about 4 cm. ( i 5^ in. ) behind and slightly above the external angular process of the frontal bone. The middle meningeal artery comes up through the foramen spinosum and then goes forward, upward, and outward to the lower anterior angle of the parietal bone. It sends branches forward to the frontal region and backward to the parietal and temporal regions. During two to three centimetres of its course, at the pterion, it passes entirely through bone, and therefore if a fracture occurs at this point it must of necessity tear the artery. The posterior branches are not regular in their course, one passing backward, low down, parallel to the zygoma, and another higher up in the direction of the parietal eminence. The branches of the meningeal artery nourish the bone as well as the dura, therefore if the dura is loosened from the bone hemorrhage from these branches occurs. The most frequent site of middle meningeal hemorrhage is in the region of the pterion or temple. In trephining for it, the centre of the trephine is to be placed on an average of 4 cm. ( I Vz in. ) behind the external angular process of the frontal bone, and on a level with the upper edge of the orbit or 4.5 cm. (134^ in.) above the zygoma. If the artery is not sutiiciently exposed more bone is to be removed by the rongeur forceps. It is in this region that epidural hemorrhages are apt to be extensive, because the vessels torn are the largest; but epidural hemorrhage can also occur in the frontal region from the anterior branches and in the parietal from the posterior. Trephining for bleeding from the posterior branch of the middle meningeal artery is somewhat uncertain. In some cases the artery runs low down, about 2 cm. (4^5 in. ) above the zygoma and parallel to it. In other cases it runs upward and backward toward the parietal eminence. The trephine may be placed as high up as for the anterior branch of the middle meningeal arterv, 4.5 cm. (i?^ in.), and 5 cm. (2 in.) farther back. This will be below and anterior to the parietal eminence and about midway on a line joining the parietal eminence and external auditory meatus. After the button of bone has been removed, additional bone may be cut away with the rongeur forceps until access can be had to the bleeding point (see page 23 for a case of rupture without fracture). attachment of the dura mater in children, the meningeal arteries are more liable to be torn and cause hemorrhage than is the case in adults. For the same reason the blood pressure is not sufficient to dissect the dura from the skull, therefore epidural clots are rare. If there is a fracture, blood may collect beneath the scalp, and if an external wound exists, the blood will find an exit through it. Bleeding from the Venous Sinuses. — Bleeding may occur from the sinuses of the base as well as from those of the vault. In severe injuries of the vault detached fragments frequendy penetrate the superior longitudinal and lateral sinuses. In these cases profuse bleeding occurs as soon as attempts are made to remove the loose pieces of bone, and it is necessary to use a packing of gauze to control it. Fractures passing through the petrous portion of the temporal bone wound the petrosal sinus and this no doubt contributes to the blood which flows from the ear. Emphysema is most Hkely to occur if the frontal air sinuses are involved, particularly if the patient blows his nose in the attempt to relieve it of blood clots. Emphysema is not so liable to occur in cases of fracture involving the mastoid cells. Cerebrospinal fluid may escape whenever the meninges are torn and the subarachnoid space is opened. It is most frequently seen in the fractures involving the middle fossa and passing through the internal auditory meatus. The meninges are prolonged into the internal meatus, and the clear fluid is not infrequently seen coming from the ear of the injured side. Although the normal amount of cerebrospinal fluid is only about two ounces, much greater quantities can escape. A serous discharge, perhaps of several ounces, is indicative of a rupture into the subarachnoid space. Injuries to Nerves in Fracture of the SkulL — The nerves most often disturbed in injuries of the skull are the first, second, third, seventh, and eighth. injured directly in the line of fracture, or by concussion. I have had under my care two such cases in women who struck the occiput on an asphalt pavement in getting off backward from a moving trolley car. These patients left the hospital after several weeks with the sense of smell still lacking. Injuries to the second or optic nerve are apt to be accompanied by such severe injuries to other parts as to cause the death of the patient before the loss of sight is discovered. If the optic nerve is injured at the optic foramen, there may be impairment of sight without any intra-ocular changes to be seen with the ophthalmoscope. Inside of two weeks, however, the pinkish color of the disk gives way to the gray-white color of atrophy, and this progresses until complete. The nerve never resumes its functions and the patient remains blind. Injury of the third or oculomotor 7ierve has also come under my notice. In this the pupil of the affected eye is moderately dilated and does not respond to light. The ciliary muscle is supplied by the third nerve, as well as the circular fibres of the iris, so that the accommodation is paralyzed and, if the eye has been normal in its refraction, the patient will be unable to read or see objects clearly at close distances. The extrinsic muscles of the eye, with the exception of the superior oblique and external rectus, are also supplied by this nerve and the eye is therefore pulled outward and slightly downward, and diplopia, or double vision, may be produced. The patient is unable to mo\'e the eye either upward, inward, or downward. The levator palpebree muscle is also paralyzed and there is ptosis or drooping of the upper lid. The orbicularis palpebrarum muscle, being supplied by the seventh nerve, has its functions unimpaired, and the eyelids can be closed. The fourth or pa.hdic nerve is almost never injured. It supplies the superior oblique muscle, which turns the eyeball down and slightly outward. Paralysis of it causes diplopia, with the image of the injured eye below that of the sound eye and tilted to the right, if the right eye is at?ected, and to the left, if the left is affected. TYieJifth or trifacial nerve \s \-ery rarely injured. If it is completely paralyzed there will be loss of motion in the muscles of mastication and loss of sensation over the side of the face, of one-half of the interior of the mouth, of the side and front of the tongue, and of the eye. The sixth or abducent ne7-ve supplies the external rectus muscle of the eye, and if paralyzed causes internal strabismus, the eye looking inward. While more often paralyzed than the fourth and fifth, it is not so frequently paralyzed as are the two following nerves. The seventh or facial nerve is the one most frequently injured in fractures of the skull. It enters the internal auditory meatus with the auditory nerve, being above it. Reaching the end of the meatus internus, it enters the canal of Fallopius and emerges from the temporal bone at the stylomastoid foramen. When paralyzed, the face on that side remains motionless, the eye cannot be closed, and food accumulates between the teeth and cheek. The corner of the mouth is drawn to the opposite side when the muscles of the face are contracted. The internal auditory meatus contains a prolongation of the dura mater and arachnoid, so that a fracture through it would open the subarachnoid space and allow the cerebrospinal fluid to escape. In these cases there is also usually bleeding from the ear. Escape of cerebrospinal fluid is to be distinguished from a flow of serum by its greater quantity, sometimes many ounces escaping. The eighth or auditory nerve is injured ^\•ith moderate frequency, but perhaps hardly so often as supposed, for the deafness which sometimes follows injuries to the head may not be caused by an injury to the auditory nerve itself, but is rather due to the injury done by concussion of the brain in the region of the first temporal convolution, or possibly to the tympanum. The eighth nerve is embraced in the same extension of the meninges into the internal meatus as is the seventh, and injuries to it may also be accompani^^d with loss of cerebrospinal fluid. The seventh and eighth are said to be more often paralyzed than any of the other ner\-es. the dura mater, the middle the arachnoid, and the inner the. pi a mater. The dura mater or fibrous covering of the brain is tough and strong and intended to protect it. Injuries of the skull without a laceration of this membrane are much less serious than when it is in\'olved. When it is torn, not only is the brain beneath likely to be injured, but an opportunity is given for infection to enter and affect the brain itself and e\-en produce a hernia cerebri or hernial protrusion of brain matter through the rent. The dura mater is composed of two lavers, the outer one acting as a periosteum to the bones. The two layers are in most places closely united, but at others they separate and form sinuses or canals, connected with the \'eins and carrying venous blood. TYiQfalx cerebri (¥\^. 27) which is the fibrous partition separating the hemispheres of the brain from one another, as well as the tentojium, which separates the cerebrum from the cerebellum, is formed by the inner layer of the dura mater projecting inward and forming a partition. On the floor of the skull, the dura mater accompanies the nerves and gives them a sheath. The Gasserian ganglion of the fifth nerve is held in a pocket formed by the separation of the two layers of the dura mater. The cerebral blood sinuses have already been considered. The dura is nourished by the meningeal arteries; bleeding from these has already been alluded to (page 17). Thin fibres of the dura pass to the bone, also branches of the meningeal arteries and veins pass to the inner table and diploe: these all serve to fasten the THE MENINGES. dura to the skull. This attachment is firmest on the base of the skull. On the vault, after an opening has been made through the skull by a trephine, the dura can be readily separated from the bone by means of a thin, flat, steel spatula. On account of the small size of the vessels passing from the dura to the bone, this procedure is not usually accompanied by much hemorrhage. In separating the dura from the base of the skull, as is done in operations on the Gasserian ganglion, the bleedino- from this source is often quite free. The dura is liable to be torn in lifting it from the bone if the greatest care is not exercised. The middle meningeal artery, at a distance of 4 cm. Ti^ in.) posterior to the angular process of the frontal bone and about the same above the zygoma, usually passes within the bone for a distance of i 01 2 cm. Therefore, in operating in the temporal region, if the dura is detached the vessel will be torn and free bleedins- will follow. The vessel is liable to be torn in endea\-oring to remo\'e bony fragments in fractures of this region. The dura is also more firmly attached in the median line; and on each side of the median line are the depressions in the parietal bone which lodge the Pacchionian bodies. The largest are usually located at a distance of from 2 to 5 cm. posterior to a line drawn across the skull from one external auditor}meatus to the other. They are prolongations from the arachnoid and are surrounded by blood from the longitudinal sinus. The Arachnoid — also called Arachnopia or Parietal Layer of the Pia. — The arachnoid is a thin fibrous membrane, which passes o\'er the convolutions of the brain and does not dip into the sulci between. It is more marked on the base than on the convexity of the brain. It is not attached to the dura above, and this subdural space, while moist, contains little or no free fluid. Hemorrhages do not occur into this space unless the membranes are torn, because the bleeding from the vessels of the dura is alwavs epidural and the arachnoid derives its nourishment from the pia mater below, so that hemorrhages start beneath the arachnoid, but may rupture through the arachnoid into the subdural space. From its under surface, fibrils of loose tissue pass to the pia mater; the space between the fibrous layer of the arachnoid above and the pia mater and convolutions of the brain below is called the subarachnoid space. This is a lymph space and contains the cerebrospinal fluid. This fluid is normally about 60 c.c. (2 ounces) in quantity, but in injuries to the brain in which the subarachnoid space is opened, the fluid is secreted and discharged very rapidly. As has already been mentioned, the arachnoid sends a prolongation into the internal auditory meatus, hence a fracture through it would open the subarachnoid space. This space communicates with the ventricles of the brain through three openings in the pia mater at the lower back portion of the roof of the fourth ventricle; these are called the foramina of Magendie, Key, and Retzins. The cerebrospinal fluid extends down the spinal canal and can be removed by tapping with a trochar, as is practised in the lumbar region. The Pia Mater. — The net- work of vessels, with their supporting membrane, which covers the convolutions of the brain, forms the pia mater. The fibrils of connective tissue supporting the vessels are attached to the fibrous layer of the arachnoid above, so that the pia and arachnoid are in reality continuous structures. The spaces between these fibrils are often quite large and communicate with each other, forming the subarachnoid space. The lower portions of these fibrils are united and form a basement membrane which lies directly on the convolutions of the brain and dips into the sulci. The blood-vessels are intimately connected with this lower pial membrane and not with the arachnoid above. These vessels penetrate into the substance of the brain, carrving with them a co\ering or sheath of pia mater. This is called \h& perivascular lymph sheath and, of course, communicates with the subarachnoid space above. These vessels nourish the brain. The perivascular lymph sheaths are also said to form capsules around the great pyramidal and large glial cells of the cortex. AFFECTIONS OF THE MEMBRANES OF THE BRAIN. Both the dura mater and the pia mater are subject to inflammation and hemorrhages. The arachnoid being practically a part of the pia mater is involved in its diseases, so that no mention is made of it as being separately affected. or interna. Pachymeniyigitis Externa. — The external surface is most often af?ected by injuries from without, or by extension of diseases from the adjoining bone. In cases of fracture the inflammation which accompanies healing frequently causes the dura to become densely adherent to the overlying skull. This is noticed particularly when trephining operations are performed for the relief of focal or Jacksonian epilepsy. Should the fracture be compound or open, the occurrence of sepsis will tend to involve the adjacent dura mater. The same occurs in cases of necrosis. Syphilitic disease of the bones is most apt to affect the vault of the skull, while the dura towards the sides and base is most often involved by suppurative ear disease. The dura also becomes in\olved in tumors and gummata. Inflammation of the dura is not apt to be a marked disease. It is a very dense membrane with few blood-vessels, therefore it is quite resistant to inflammatory processes. It acts as a barrier to the farther extension of an inflammation rather than as a carrier. Therefore we see epidural collections of pus existing for a considerable time without brain symptoms supervening. The dura mater contains the large cerebral venous sinuses, and when the inflammatory process occurs in those regions, the sinuses become inflamed and thrombosis or clotting occurs. The clot becoming infected breaks down, the pus and debris pour into the general circulation, and general septicaemia, and even death, is caused. This is most liable to occur in the region of the ear, where the infection is apt to reach and involve the lateral (transverse) sinus. Infection of the longitudinal sinus is much more rare. Pachymefiingitis interna is an inflammation of the inner surface of the dura. It occurs, to a certain extent, in cases of gumma or other new growths involving the inner surface of the dura or extending from the pia mater below. The name pachymeningitis interna, also called haemorrhagica, is usually restricted to a chronic inflammation of the inner surface of the dura, with the formation of one or more hemorrhagic membranous layers. Adhesions to the pia do not occur. The disease has been seen in purpuric and infectious diseases, as well as in alcoholic and demented individuals. Dural Hemorrhage. — Hemorrhage arising from injury to the dura through fracture of the skull has already been discussed (see page 18). Epidural hemorrhage . may, however, occur from an injury to the skull and detach the membrane from the bone without a fracture being present. The possibility of this occurring is proved by the remarkable case reported by Dr. J. S. Horsley {New York Med. Jour., Feb. 9, 1 901). He was momentarily stunned, but soon recovered and felt perfectly well. An hour and a half later he became drowsy, and in a few hours was in a state of stupor. The right side of the body and face was paralyzed, and the left arm and leg were in constant jerking convulsions. He was trephined over the left parietal eminence and four to six ounces of blood clot removed. There was no evidence of fracture or wound of the dura. Recovery was prompt. There have also been other recorded cases. In operations involving the separation of the dura from the bone, bleeding may be quite free. This comes from rupture of the veins passing from the bone to the dura, and sometimes from the rupture of a vein passing over or in the dura itself. Subdural hemorrhages always originate from the pia mater. Inflammation of the Pia Mater; Meningitis. — This, when not of a tuberculous character is called leptomeningitis. It is commonly known as inflammation of the brain, or meningitis. The pia mater of the brain being directly continuous with that of the spinal cord, inflammations of the former extend to and involve the latter in about one-third of the cases. The disease is then called cerebrospinal meningitis. Infection is the usual cause of leptomeningitis. Direct injury to the membranes and their bony envelopes may cause it, but it occurs usually through some secondary avenue of infection. Thus, it may follow fractures opening into the mouth, nose, the various accessory bony sinuses, ear, etc. The infection may, however, not be traumatic, but occur through the blood, following or accompanying the various infectious diseases. Owing to the fact of the pia lying on the brain substance, and its vessels with their perivascular sheaths penetrating it, the disease naturally tends to involve the brain, if it is very severe or long standing. If such is the case, the afiection is called cerebritis or encephalitis. The inflammation may be serous, plastic, or even purulent. The pia mater being continuous with the choroid plexuses, the ventricles may be dilated by the increased fluid. The infection may follow the vessels into the brain and produce brain abscess. The effusion being often localized at the base of the brain interferes with the functions of the cerebral nerves. The first, or olfactory, is comparatively rarely affected. The optic, or second, is more often so, producing intolerance of light. There may be choked disk, and I have even seen a case in which there was total blindness without any change being visible in the nerve by means of ophthalmoscopy. In this case atrophy of the disk soon followed. The third, or motor oculi, according to Church and Peterson, is almost always affected. This would be shown by strabismus, diplopia, and changes in the pupil. Facial paralysis, from implication of the seventh ner\e, is sometimes seen, and the auditory, or eighth, may also be affected. Involvement of the hypoglossal or twelfth nerve, will be shown by deviation of the tongue. The origin of the cranial nerves from the base of the brain is shown in Fig. 28. Tuberculous Meningitis. — In this form of meningitis the infection comes through the blood, and the tuberculous lesions follow the vessels. They are most marked on the base of the brain, involving the circle of Willis and the Sylvian fissure. The infection follows the vessels of the pia mater through the transverse fissure into the ventricles. The effusion accumulating in the ventricles has given rise to the name acute hydrocephalus. It also follows the perivascular sheaths of the smaller vessels into the brain substance, producing a cerebritis; thus it is seen how a knowledge of the circulation of the brain explains the location of the lesions. noid in the subarachnoid space. If, however, the blood has escaped with considerable force, it tears its way through the arachnoid and spreads in the subdural, as well as through the subarachnoid space. The origin of this form of hemorrhage is the vessels of the pia mater. The arachnoid does not give rise to hemorrhages, neither does the inner surface of the dura, unless it has previously been the seat of pachymeningitis interna. The hemorrhage is the result either of injury or disease. In children it is usually due to injurv; in adults to either injury or disease. These hemorrhages are most common in infancy and occur in childbirth. They are due apparently to hard, protracted labor or injury done to the child in effecting delivery by forceps, etc. , especiallv in infants born before full term. They are a cause of idiocy and the cerebral palsies of childhood. These hemorrhages in the new-born have been A biain, sliowinsr exit ul Liamai recognized by the convulsions they produce, and successful operations have been performed for their relief (see Harvey Gushing — "Surgical Intervention for the Intracranial Hemorrhages of the New-born " — Am. Jour. Med. Sci., October, 1905). Injuries received later in life from blows on the head often produce subdural or pial hemorrhages, without breaking the overlying bone. They are found eitlier at the site of impact or on the side opposite that on which the blow was received, the latter being produced by contre-coup. When pial hemorrhage occurs from disease, it is usually from rupture of an aneurism of one of the vessels of the pia mater. If it does not break through the arachnoid into the subdural space, it may spread over a considerable portion of the cerebral cortex, especially filling the sulci. Unless the quantity is quite large, so that it interferes with the motor area, hemiplegia will not occur. Convulsions may occasionally occur from irritation of the cortex. Blood in the subdural space may tra\-el along the base of the Ijrain and into the sheath of the optic nerve. THE BRAIN. The affections of the brain of most anatomical interest are those mvolving its circulation, the motor areas, and the motor paths. Paralyses may arise from (a) interference with the motor areas in the cortex by hemorrhages, injuries, or tumors; {b) destruction of the motor paths from the cortex to their point of exit from the brain; (c) injury of the nerves at their exit from the brain. form the basilar, which at the upper border of the pons divides into the two posterior cerebrals. The carotids divide into the anterior and middle cerebral arteries, the anterior communicating with one another bv means of the anterior communicating artery. Thus we have the circle of Willis (circulus arteriosus), formed hy xh.^ posterior cerebral, posta-ior communicating, internal carotid, ayiterior cerebral, and anterior communicating arteries on each side. The blood supply of the brain is divided into an anterior division, furnished by the carotids, and a posterior division, supplied through the basilar and posterior cerebrals. The communication branch running between these two sets of vessels is so small that if either is occluded the supply of blood is practically cut off from that point and ischaemia results, at least in most cases. arteries. These communicate across the median line through the anterior cerebral and anterior communicating. — The internal carotid artery in its course through the skull, showing its relations to the jugular vein and cranial nerves. The Gasserian ganglion has been raised from its bed and turned forward. infrequently followed ligation of the carotid artery in cases of aneurism. Obstruction of one vertebral artery would produce no effect because circulation would be restored by the other vertebral through the basilar. Internal Carotid Artery. — The internal carotid artery (Fig. 30) enters the petrous portion of the temporal bone, then turns inward and upward through the foramen lacerum medium, then forward through the cavernous sinus and finally turning surface of the brain. upward gives off the ophthalmic artery; it then pierces the dura mater just behind the anterior clinoid process, where, after giving off the posterior communicating and anterior choroid, it divides into the anterior and middle cerebral arteries. Anterior Cerebral Artery. — The anterior cerebralfFig. 31) passes for^vard and inward over the anterior perforated space, between the olfactory and optic nerves, to the median fissure. It gives off the anterior communicating artery at this point, which ioins the anterior cerebral of the opposite side. The main trunk then runs upward in the longitudinal fissure on the corpus callosum, giving branches to the frontal and parietal lobes, and finally anastomoses at the posterior end of the corpus callosum with the posterior cerebral. This shows the wide extent of brain tissue on the medial surface of the brain which would be affected by the blocking of this vessel by an embolus. The terminal branches of the anterior cerebral spread laterally over the surface of the brain (Fig. 32) outward from the longitudinal fissure for a short distance, about 2 cm. As it crosses the anterior j^erforated space, it gives off the anteromedian perforating (ganglionic) arteries which pierce the lamina cinerea to supply the anterior portion of the caudate nucleus above. Middle Cerebral Artery. — The middle cerebral artery passes upward and outward in the fissure of Syh'ius, di\'iding, when opposite the island of Reil, into the branches which supply the cortex of the brain (see Fig. 32), On its way toward Fig. 34. — Showin.s: the degenerative and apoplectic areas of the brain and the course pursued by the motor fibres from the cortex, through the niternal capsule, crura, pons, and medulla to the decussation, where they cross the median line to supply the opposite side of the body. the island of Reil, at the commencement of the fissure of Syhius, many small straight branches enter the brain substance to supply the basal ganglia. Two or three supply the caudate nucleus, others, called the anterolateral perforating (ganglionic), enter the anterior perforated space to supply the lenticulostriate ganglion and the anterior portion of the thalamus. One of the largest of these arteries, the lentiadostriate, has been called the artery of cerebral hemorrhage, by Charcot, on account of the frequency with which it is found ruptured in cases of apoplexy (Fig. 33). Anterior Choroid. — The anterior choroid artery comes sometimes from the internal carotid and sometimes from the middle cerebral. It passes backward and outward on the optic tract and crus cerebri and enters the transverse fissure at the descending horn of the lateral A-entricle. It ends in the choroid plexus (see P"ig. 33). Posterior Cerebral Artery. — The posterior cerebral artery passes outward over the crus cerebri, just above the pons, to the under surface of the posterior portion of the cerebral hemisphere. Before it receives the posterior communicating artery it gives off the posteromedian perforating (ganglionic) arteries, which enter the posterior perforated space to supply the thalamus and third ventricle. Just beyond the poste- Veins of Galen Fig. 36.— Horizontal section of brain ; the corpus callosum and fornix have been removed, exposing the lateral ventricles, with the caudate nuclei projecting into them anteriorly and the velum interpositum farther back, with the choroid plexus at the sides and the veins of Galen nearer the middle line. The lateral ventricles in this braia are somewhat larger than usual. Cerebral Softening. — This occurs in the young from emboHsm ; it then affects the cortex, but the more common variety is caused by thrombosis in arteries which are diseased, usually in the aged. The part farthest from the source of blood supply is the most apt to suffer, therefore we find it occurring most frequently in the anterior capsuloganglionic region, just above the usual site of apoplexy (Fig. 34). The affected area will be seen to be most remote from both the cortical and basal blood supply. The perforating arteries supplying this region are in the nature of terminal branches and do not anastomose to any extent either with each other or with the branches coming from the cortex, hence their occlusion inflicts irreparable damage. Apoplexy. — By apoplexy is meant the rupture of a blood-vessel with consequent extravasation of blood, either in or on the brain. It may occur in any portion of the brain, and either from the arteries of the base^ or from the smaller arteries of the cortex. The former is the more frequent. The arteries that most often rupture are the branches of the middle cerebral which enter the anterior perforated space, especially its outer portion. One of the largest of these anterolateral arteries, as has already been mentioned, known as the lenticulostriate, has been called b}^ Charcot the artery of cerebral hemorrhage. Figure 35 is a medial section of the brain, giving a lateral view of the ventricles. Figure 36 is a horizontal transverse section of the brain, opening up the ventricles. In front are seen the two lateral ventricles., separated by the septum lucidum. The cavity shown in the septum lucidum is the so-called y?/?/z ventricle. The round body bulging into the lateral ventricle and forming its floor is the caiidate n^cclens portion of the corpus striatum. The third ventricle is posterior and below the lateral ventricles, and extends from the septum lucidum in front to the posterior pillars of the fornix behind. It extends from side to side as one large cavity with no median partition. Bulging into the third ventricle on each side are the (optic) thalami. They are se])arated from the corpora striata by some white fibres, the tcenia semicircularis. To the inner side of the taenia semicircularis is seen the choroid plexus, which runs down anteriorly over the thalamus to the foramen of Moiiro, through which it enters the lateral ventricle. Two large veins, the vei7is of Galen, pass down near the middle line of the third ventricle to empty into the straight sinus. Posteriorly, the choroid plexus follows the descending horn of the lateral ventricles. The choroid plexus hangs from the under surface of the velnm ijiterposifmn, which is a fold of the pia mater entering through the transverse fissure. The veins of Galen run between the two layers of the velum interpositum. Turning now to Fig. 37, showing a somewhat deeper transverse horizontal section, running through the corpus striatuvi and thalamus, it will be seen that to the outer side of the corpus striatum and thalamus is a white layer constituting the internal capsule. It divides the corpus striatum into tw^o parts, one to its inner side, which projects into the lateral ventricle, called the caudate nucleus, and Decussation Fig. 38. — Showing the degenerative and apoplectic areas of the brain and the course pursued by the motor fibres from the cortex, throutch the niternal capsule, crura, pons, and medulla to the decussation, where they cross the median line to supply the opposite side of the body. the other to its outer side, called the lenticular micletis. To the inner side of the posterior portion of the lenticular nucleus and internal capsule is seen the thalamus. To the outer side of the lenticular nucleus one sees other white fibres called the external capside. An apoplectic hemorrhage occurring in the lenticular nucleus or internal capsule may push forward and rupture into the lateral ventricle. It may go backward and involve the anterior portion of the thalamus and burst into the third ventricle, and if it extends outward it involves the external capsule. Sometimes, if the hemorrhage is low down, it ruptures downward through the base of the brain, showing itself, of course, at the anterior perforated space. Fig. 38 shows these structures as seen in a medial section of the brain. In Fig. 38 there is a coronal transverse section of the brain, showing the course of fibres of the internal capsule from the cortex of the brain through the corpus striatum, between the lenticular and caudate nuclei : then, forming the crus cerebri, the fibres pass through the pons and medulla to enter the spine, decussate, and pass to the extremities. This constitutes the motor pathway from the cortex to the extremities, and when it is injured in apoplexy, the extremities of the opposite side are paralyzed. two different sets of symptoms, according to its location, which is due to the fact that the fibres of the seventh or facial nerve, in their passage from the cortex to the face, decussate in the pons. If, however, the hemorrhage is below the point of decussation, the side of the face on the side of the lesion will be paralyzed and the extremities of the opposite side, thus producing what is known as crossed, paralysis, that is, a paralysis of the face on one side and of the extremities on the other. rhages of the cortex are apt to be less in extent and more localized on account of the smaller size of the vessels affected. They either destroy or irritate the bram at the site of injury, and produce, if they involve certain areas of the brain, definite peripheral symptoms which serve to indicate the seat of lesion. Spinal nerves Fig. 39. — Diagram illustrative of crossed paralysis. A clot in the upper portion of the pons causes paralysis of the muscles of the face and extremities of the same side of the body. A clot in the lower portion of the pons causes paralysis of one side of the face and the extremities of the opposite side of the body. The parietal lobe extends from the fi.ssure of Rolando (central sulcus) in front to the parieto-occipital fissure behind. Below, it is limited anteriorly by the fissure of Sylvius, while its posterior portion merges into the temporosphenoidal lobe. The central lobe or island of Reil, also called the insula, consists of five to seven convolutions which radiate upward; it can be seen by separating the two sides of the anterior portion of the fissure of Sylvius. sions, fissures or sulci. The fissures are called main or subsidiary fissures, according to their importance. The five main fissures are the longitudinal fissure, which separates the hemispheres; the transverse Jissure, which separates the cerebrum and cerebellum and communicates with the third ventricle; the Jissiwe o/ Sylvius; the Jissure of Rolando, or central fissure, and the parieto-occipital fissure. lutions. That portion of the inferior or third left frontal convolution which surrounds the ascending limb of the fissure of Sylvius is called Brocd s convolution, and is the ceyitre for speech. Posterior to these and running upward and backward, forming the anterior wall of the central fissure, is the precentral or ascending frontal convolution. The convolution forming the anterior extremity of the parietal lobe and the posterior wall of the central sulcus or fissure of Rolando is called the postcejitral or ascending parietal convolution. Immediately behind it is the postcentral or interparietal sulcus. The upper portion of this sulcus divides, one branch going upward and one backward. Immediately above the posterior branch is the superior parietal gyj'us or lobule, and below it and surrounding the posterior extremity of the fissure of Sylvius is the S2ipramarginal gyrus. Posterior to the supramarginal gvrus and surrounding the posterior extremity of the superior temporal, or temporosphenoidal sulcus is the convolution known as the angular gyj-us. occipital convolutions by the lateral occipital sulcus. The temporal or temporosphenoidal lobe is also divided into superior, middle, and inferior, or first, second, and third temporal convolutioyis by the superior, or parallel, and middle fissures. On the under surface is a fourth temporal convolution, separated from the third by the inferior temporal fissure. These fissures ma}' not be distinct. THE MEDIAL SURFACE OF THE HEMISPHERES. If now the medial surface of the hemisphere, which forms one side of the longitudinal fissure, be examined, there is seen a large convolution running just above and parallel with the corpus callosum. It is called the gyrus cingidi {fornicatus). Below and separating it from the corpus callosum is the callosal fissure; above it is the callosomarginal fissure. The convolution above the latter, forming the margin of the hemisphere, is the marginal convolution. The callosomarginal fissure at its posterior portion turns upward and ends on the margin of the hemisphere, just posterior to the fissure of Rolando, or central fissure, and serves to identify it. This marks the posterior limit of the frontal lobe. The posterior end of the frontal lobe surrounds the upper end of the central fissure and on that account is called the paracentral lobtile. Its anterior boundary is marked by the paracentral fissure, or sulcus. Between the callosomarginal fissure in front and the parieto-occipital fissure behind is the parietal lobe, called, from its square shape on the medial surface, the quadrate lobule, or from being anterior to the cuneus lobule, the prectineus. Running downward and back- ward from the deeper portion of the parieto-occipital fissure is a very distinct depression called the calcarine fissure. These two fissures include a wedge-shaped piece of the occipital lobe called, from its shape, the cuneus lobule. It is of interest in reference to the sense of sight. CEREBRAL A knowledge of the functions of the various portions of the brain is necessary in order to localize a diseased area. The diseases and injuries to which the brain is exposed oftentimes do not involve the whole brain, but only certain distinct and isolated _ parts. The brain is not a single, homogeneous organ that acts only as a whole; it is complex. It is composed of a number of separate parts or areas, which may act either singly or in conjunction with other areas. These separate areas have different functions, so that if the disease or injury is limited to one of them, we have its functions abolished, and the symptoms produced indicate the area affected. These areas are situated on the surface or cortex of the brain in the gray matter. They receive impressions from, and transmit impulses to, all parts of the body through the white matter or fibres of the brain. An injury to the cortex or gray matter destroys the originating and receptive centres. An injury to the white matter destroys the paths to and from these centres and therefore prevents them from receiving impressions or sending out impulses. Thus, we may have a paralysis of the leg and arm caused by an injury to the leg and arm centres in the cortex of the brain, as by a hemorrhage from a fracture, or we can have the same paralysis matter fibres. The exact localization of the functions of all parts of the brain has not been accomplished, but the functions of many areas have been definitely proven. In cases of brain tumor, abscess, hemorrhage, injury, etc. , a knowledge of these areas enables one to localize the seat of the lesion. FUNCTIONS OF THE CONVOLUTIONS ON THE SURFACE OF THE CEREBRUM. The frontal lobe may be conveniently divided into three areas; prefrontal, midfrontal, and postfrontal. The prefrontal area embraces all the superior, middle, and inferior frontal convolutions, with the exception of their posterior ends. On the medial side it reaches to the callosomarginal fissure. The function of the prefrontal area is said to be that of higher cerebration, as attention, judgment, and comparison. This region, particularly the lower portion, is liable to injury, owing to its anterior position and to the fact that it overlies the orbit. The roof of the orbit is quite thin and liable to fracture by penetrating bodies, as umbrellas, canes, etc. Sometimes a portion of this part of the brain may be destroyed without marked interference with the mental qualities of the patient. This occurred in the case of a boy who was struck in the eye bv a carriage pole (personal observation). The eye was burst, necessitating its removal. Several pieces of the fractured bone of the roof of the orbit were removed and brain tissue came away for several days. The boy recovered and for sixteen vears apparently had no resulting mental deficiency. The midfrontal area embraces the posterior portion of the superior and middle convolutions, with the upper posterior portion of the inferior. It is concerned in certain movements of the eyes and lids, and also in turning the head toward the opposite side. This midfrontal division is the most anterior portion of what is called the motor area. Speech Centre, or Broca's Convolution. — The centre of speech is located in right-handed people in the posterior portion of the third left frontal com-olution, where it arches around the ascending limb of the fissure of Svlvius. It is called Broca's convolution. The faculty of writing or written speech is attributed to the graphic centre in the posterior extremity of the second frontal con^■olution just above and behind Broca's convolution. The postfrontal area embraces the ascending frontal convolution in front of the fissure of Rolando or central fissure. It is concerned in the ^'arious movements of the trunk and extremities, and forms the anterior portion of the Rolandic area; it will be considered under that head. or contraction of the muscles connected with it, and is the region most frequently affected by injuries. This is partly due to the fact of its proximity to the middle meningeal artery, as a hemorrhage from that vessel produces a clot which covers and involves this area. of Rolando, or central fissure. The f"'-' jrt of Rolando passes downward and forward from the longitudinal fissure, at an angle of about 70°, nearly to the fissure of Sylvius, being separatee ;rom it by the joining of the ascending parietal and ascend- area is almost exclusively anterior to the central fissure. The upper portion of the motor area, near the longitudinal fissure, is concerned with the movements of the toes and lower extremity. The leg centres are toward the upper end of the central fissure; next are those of the abdomen and chest. The arm centres are toward the middle, and the face centres, including the larynx. tongue, and platysma myoid muscle, around its lower extremity. The leg, arm, and face centres are, respectively, opposite the posterior extremities of the superior, middle, and inferior frontal convolutions. paracentral lobule. The Sensory Area. — The portions of the cerebrum involved in cutaneous and muscular sensibility embrace the posterior portion of the parietal convolutions, the precuneus or quadrate lobule, and gyrus fornicatus as far forward as the motor area on the medial aspect. The visual area embraces the occipital lobe, particularly its cuneus lobule, and region of the calcarine fissure on the medial surface of the hemisphere. The anterior portion of the occipital lobe and the region of the angular gyrus are con- The Auditory Area. — The centre for hearing is located in the superior and middle temporosphenoidal convolutions. It requires destruction of these convolutions on both sides of the brain to produce total cerebral deafness. The memory or recognition of spoken words (word hearing) is apparently performed by the posterior ends of the superior and middle (ist and 2d) temporosphenoidal convolutions. FUNCTIONS OF THE BASAL GANGLIA. Corpus Striatum and Thalamus. — The exact functions of the corpus striatum, embracing the caudate and lenticular nuclei, and of the thalamus are not known. They are most often affected in apoplexies ; lesions of the corpus striatum are accompanied by disturbances of motion, and those of the thalamus by disturbances of sensation. tegmental region, pons, medulla, and spinal cord below. These fibres go to form the internal capsule. Crura Cerebri. — The crura cerebri transmit both sensory and motor impulses. Note their proximity to the third nerve, as thev are apt to be involved by the Cerebral conex same lesions, thus accounting for ])aralyses or sensorv disturbances of the trunk or extremities accompanied by ocular paralysis. Pons Varolii. — The pons transmits the motor or pyramidal tract, and also the fifth, sixth, and seventh nerves. Implication of the seventh or facial nerve, together with the motor tract, has already been alluded to (page 32). If the sixth or abducent nerve is involved, the external rectus muscle on that side will be paralyzed. If the fifth, or trifacial nerve is affected, irritation of its motor root may produce trismus or clenching of the jaws, and interference with its sensory root may cause anaesthesia of one side of the face. ward from the cortex, the corona radiata becomes smaller and passes, in the form of a band, between the lenticular nucleus on the outside and the caudate nucleus and thalamus on the inside. This band is known as the intej'iial capsule. It transmits in its anterior portion fibres from the prefrontal or higher psvchical area; then come the motor Fig. 48. — Diagram showing course and decussation of corticospinal (pyramidal) tract ; M, medulla; P.pons; CP, cerebral peduncle; T, thalamus; C, L, caudate and lenticular nuclei ; CC, corpus callosum. (Piersol.) The motor fibres of the internal capsule pass downward through the anterior portion of the crus cerebri and pons into the medulla, at the lower part of which the majority decussate and pass into the anterior columns of the cord as the ^rr^widal tracts. Thus, it is seen that destruction of any portion of the motor tract, from the point oi pyramidal decussation below, through the internal capsule to the cortex above, will cause a paralysis on the opposite side of the bodv. CRANIOCEREBRAL TOPOGRAPHY. For the purpose of operating on the brain it is essential to know the bony landmarks of the skull, the lower level of the brain, and the relation which the various fissures and convolutions bear to the surface. Pterion. — This name was given bv P. Broca to the point where the frontal, parietal, and sphenoid bones meet in the region of the temple. It is about 2.5 cm. ( I in. ) behind the angular process and should not be confounded with the Sylvian point, which is 1.5 cm. (S^ in.) farther posterior, where the temporal, parietal, and sphenoid bones meet. Horsley called this latter point the pterion. The region of the pterion is the seat of the anterolateral fontanelle in the foetus. Asterion. — This lies 2 cm. (4 in.) behind the base of the mastoid process, where the parietal, occipital, and temporal bones meet. It is on the superior curved line and in fetal Hfe forms the posterolateral fontanelle. at the asterion. Its anterior third is well marked, but as it crosses the coronal suture it fades away and gradually broadens out, its upper margin being called the superior and its lower the inferior temporal ridge. The superior ridge marks the attachment of the superficial layer of the temporal fascia, the inferior, the deep layer. Sylvian Point. — Where the anterior ascending and anterior horizontal limbs come off from the posterior horizontal limb of the fissure of Sylvius. It lies 4 cm. (i^ in. ) posterior and a little above the external angular process, at the junction of the parietal, sphenoid, and temporal bones. The Lower Level of the Brain. The lower level of the brain is marked by a line beginning in the median line I cm. (f in.) above the nasion, thence above the orbit i cm. from its edge to the external angular process; from here it goes to the middle of the zygoma, thence backward along its upper border, above the auditory meatus and along the superior curved line to the inion (occipital protuberance). FISSURES AND CONVOLUTIONS. The conformation of the various fissures and convolutions varies so much within normal limits that it is not possible to outline them on the surface of the scalp or skull with absolute exactness. The various lines which are laid out to indicate their course are, therefore, only approximate, but they are sufificiently accurate for operative purposes. To allow for variations, the openings made are usually large, and the motor areas are sometimes identified by the application of an electrode. Fissure of Sylvius (fissura cerebri lateralis). — To indicate the course of the Sylvian fissure, a line is drawn from the external angular process of the frontal bone through a point 2 cm. (j^ in.) below the most prominent part of the parietal eminence and ending 1.5 cm. (f^ in.) above the lambda. The main portion of the Sylvian fissure begins 2 cm. (^ in.) behind the angular process; 2 cm. farther back or 42 mm. ( i ^ in. ) behind the angular process is the Sylvian point, where the anterior horizontal and anterior ascending limbs are given off. From this point the posterior horizontal limb passes backward to 2 cm. ( ?<;. in. ) below the highest point of the parietal eminence and then curves upward and backward for a distance of 1.25 cm. to 2 cm. (54 to 3/^ in.). Central Fissure, or Fissure of Rolando (sulcus centralis). — The line of the central fissure begins at the ujjper Rolandic point, 1.5 cm. (^g in.) behind the middle of a sagittal line passing from the glabella to the inion. It then passes down and forward at an angle of approximately 70° (67^, Chiene) toward the middle of the zygoma (Le Fort) to end at the lower Rolandic point, where it intersects the Sylvian line. It is about 9 cm. (3^ in.) long. The central fissure stops I cm. above the Sylvian line or fissure. Parieto-occipital Fissure (fissura parieto-occipitalis). — The position of this fissure is quite variable, an average being 1.5 cm. (5/s in.) above the lambda, and extending 1.25 cm. ( }4 i"- ) out from the median line. It is about 6 cm. (2}^ in.) above the inion and on or below the line of the Sylvian fissure. The middle temporal sulcus runs close above the zygoma. The third or inferior and the fourth temporal convolutions lie on the base of the brain, separated by the inferior temporal sulcus. The fourth temporal convolution has on its inner side the collateral fissure (see Fig. 42). The lateral occipital sulcus lies close to the tentorium; it divides the occipital lobe into superior and inferior convolutions. (Sometimes these two sulci divide the lobe into three convolutions, superior, middle, and inferior.) The Fissures in Children. — In childhood the fissure of Rolando is somewhat more vertical than in adults; the fissure of Sylvius has its point of division a little higher and runs up to and usually above and in front of the parietal eminence (Dana, Afed. Record, Jan. 1889, p. 29). After the age of three years, the relative position of the fissure to the parietal eminence begins to approach that of the adult. (For variations due to age see Cunningham: " Contributions to the Surface Anatomy of the Cerebral Hemispheres," 1892.) The objects of cerebral topography are mainly to ascertain in case of injury or disease of the superficial structures what parts of the brain beneath are liable to be involved, and for operative procedures, in order to expose the affected areas. The convolutions and sulci are so variable that all guides are only approximate. In order to overcome this defect and provide for unusual conditions, the openings in the skull are usually made quite large. The flaps of scalp and bone may e\en embrace the entire parietal bone or a quarter of one hemisphere. As regards the various points — the upper Rolandic point is generally conceded to be 15 mm. (^ to ^ in.) posterior to the midpoint between the glabella and inion. The angle which the fissure forms with the median line varies from 64° to 75°. Cunningham gives it as 70° and Arthur W. Hare as 67°. Chiene's method of finding the desired angle is usually accepted as reliable. He takes a square piece of paper and folds it obliquely from corner to corner making 45°, and then folds it a second time making 22>^°. The two being added together give 67^-^° as the angle made by the fissure of Rolando with the anterior portion of the longitudinal fissure. The pterion was placed by Broca at the coronal suture. This is 15 mm. (2 in. ) in front of the Sylvian point. In several formalin hardened brains, we found this latter to be at the posterior angle of the pterygoid wing, and in twenty measured skulls the Sylvian point averaged 42 mm. {\Y% in.) behind the angular process. Reid placed it at 50 mm. ( 2 in. ) , which we think too much. Anderson and Makin placed it at i ^ to 2 in. Thane and Godlee placed it 35 mm. back and 12 mm. up, which is just a trifle farther forward than we have located it. Landzert and Heffler gave it as at the summit of union of the great wing of the sphenoid with the temporoparietal suture, as we have given it. When prolonged, the .Sylvian fissure sometimes crosses the median line 1.5 cm. (^ in. ) above the parieto-occijiital fissure, but more usually we have found it to be close to the fissure, which agrees with Reid. The parietooccipital fissure has been located by some authors near the lambda, but we would place it 1.5 cm. ( y?, in.) above. We believe the parietal eminence to be a fairly reliable guide to the posterior extremity of the fissure of Sylvius. ]\Iethod of Anderson and IMakin for Locating tlic Fissures of the Brain. — For the sake of comparison the following method of Wm. Anderson and George Henry Makin {Jour. Anat. and Phys., vol. xxiii, 1S88-89, p. 455) is given. Draw a mid- or sagittal line from opposite the highest point of the supra-orbital arches to the external occipital protuberance. From the midpoint on this line draw another to the pre-auricular point at the level of the upper border of the meatus. This is the frontal line. From the most prominent point of the e.xternal angular process draw a line to the junction of the middle and lower thirds of the frontal line and prolong it 1% in. beyond. The Sylvian fissure begins between i}i and i>2 in. behind the angular process or f- of the distance between that point and the frontal line. The bifurcation is i>^ to 2 in. behind the angular process or yV of the distance between it and the frontal line, the fissure then runs to an equal distance behind the frontal line, and up for >^ in. parallel to the frontal line. The fissure of Rolando runs from a point Ys in. behind the midsagittal point to one y% of an inch in front of the intersection of the frontal line and line of the Syhian fissure. The parieto-occipital fissure is fj of the distance from the midsagittal point to the inion. It lies near the apex of the lambdoid suture. ing relation of Rolandic and Sylvian fissures and lines. book of the Medical Sciences," vol. viii., p. 229) has given three points, as follows: (i) Onehalf to three-fourths of an inch (1.25 to 2 cm.) on either side of the median line and one-third of the distance from the glabella to the upper end of the central (Rolandic) fissure. This is high enough to avoid the frontal air-sinuses and is in advance of the motor area. A grooved director is to be thrust in the direction of the inion. The ventricle is reached at a depth of 5 to 6.5 cm. (2 to 2% in.) through the first frontal convolution. (2) Midway between the mion and upper end of the central (Rolandic) fissure 1,25 to 2 cm. (,'-< to ^{ in. ) from the median line. The director is to be thrust to\\ard the inner end of the supra-orbital ridge of the same side. The ventricle will be reached at a depth of 5.5 to 7 cm. (2I4 to 2 V in-'> from the surrace. (3) Three centimetres (114^ in.) behind the external auditory meatus and the same above Reid's base line (from the lower border of the orbit through the centre of the e.xternal auditory meatus). The director is to be thrust toward a point 6.25 to 7.5 cm. (2 '2 to 3 in.) directly above the opposite external meatus. The ventricle will be reached 5 to 5.75 cm. (2 to 2'+ in.) from the surface. The director passes through the second temporal convolution; this is the preferred method. Spitzka {New York Med. Jour., P'eb. 2, 1901, p. 177) has pointed out how these ventricles vary in shape, and has given the surface relations in two brains. T. T. Wilson {Jour. Anat. and Phys., vol. xxviii, 1894, pp. 228-235) has described and figured them in three drawings. Spitzka states that the ventricles will hold about &o c.c. of liquid. Cerebral Abscess. — About one-half of the abscesses of the brain occur from disease of the middle ear, and they are located in the temporosphenoidal lobe, in the cerebellum, or between the dura and petrous portion of the temporal bone. The remainder are caused either by blows or infection carried to the part in infectious diseases. They may, therefore, occur anywhere in the brain. When the motor areas around the fissure of Rolando are involved, the location of the trouble will be shown by spasm or paralysis of the corresponding muscles. If the occipital lobe is affected there may be disturbance of sight, as hemiopia. Involvement of the frontal lobes produces mental dulness, and if of the third left frontal gyrus, or Hroca's convolution there may be impairment of speech. Disease of the middle lobe of the cerebellum may be accompanied by a staggering gait. In many cases localization symptoms are rare, particularly when the abscess is small and located in the temporosphenoidal, parietal, or frontal lobes (see chapter on cerebral localization). Trephining. — If the abscess arises from middle-ear disease, it is customary to first open the mastoid antrum (see chapter on ear) and then by removing the bone above to explore the surface of the petrous portion of the temporal bone. To explore the temporal lobe an opening may be made 2.5 cm. (i in.) above the external auditory meatus and a needle passed inward, forward, and a little downward. To reach the cerebellum, the trephine should be applied 5 to 7 cm. (2 to 234 in.) behind the external meatus and well below the superior curved line. The bone at this point is apt to be thin and care is to be exercised not to wound the membranes. The place of trephining in abscesses from other causes is to be decided by the localizing symptoms. THE FACE. The face may be divided into the regions of the forehead, temples, ears, eyes, nose, moiith, eheek, and 2ipper and loiver jaws. The regions of the eyes, ears, nose, and mouth will be considered separately. Owing to the face being that part of the body most open to scrutiny and most difficult of conceahTient, deformities and disfigurements of it, resulting from injury or disease, — to both of which it is prone, — assume a greater importance than the same troubles elsewhere. Therefore, the anatomy of the part should be studied with regard to the treatment of its various affections from a cosmetic as well as from a curative point of view. What is usually regarded as constituting the face embraces the anterior half of the head as \iewed from the front. The Bones, — The bones of the head have been divided into those of the cranium and those of the face. The bones of the cranium are eight in number, \\z. : the frontal, occipital, two temporals, two parietals, the sphenoid, and ethmoid. The bones of the face are fourteen in number, of which twelve are in pairs, viz: superior ma.xillary, malar, nasal, palate, lachrymal, and inferior turbinated bones — the vomer and inferior maxilla or mandible are the two single bones. From this it will be seen that the bony framework of the face embraces some of the bones of the skull, as well as those of the face proper; thus, the region of the forehead is formed by the frontal bone, the temporal region is formed by the frontal, parietal, sphenoid, and temporal bones, all belonging to the cranium, and so on. The palate bones are called face bones, yet they are placed deep in the region of the mouth and nose. The Soft Parts. — The soft {)arts are likewise of importance. The skin, thin in some parts, thick in others, is in many places loosely attached and has inserted in it the muscles of expression. It is frequently the seat of disease, particularly of cancer. numerous and give special characters to woimds and diseases of the face. The nerves are abundant and complex. They are, with the exception of the auricular is luagnus, which comes from the second and third cer\-ical, and to a slight e.xtent the occipitalis minor from the second cer\'ical, all deri\'ed from the cranial nerves and are both motor and sensory. The paralyses and neuralgias which wounds of the face producing paralysis of the muscles of expression. The relatively small size of the face in relation to the cranium in the child as compared to that of the adult has already been alluded to Tsee page 8). The reasons for this are evident: dentition must be complete to insure the proper development of the jaws; the use of the special senses and the expression of the emotions cause the facial muscles to develop, and this in turn causes the bones to which they are attached to become more rugged in outline and larger in size. In old age, as the teeth are lost, the jaws are diminished in size by absorption of their alveolar processes. front and anterior to the temples at the sides. The Frontal Suture. — The frontal bone develops from two centres of ossification, one on each side. These unite in the median line to form the frontal suture which joins the anterior fontanelle and is closed about the same time, within the age of two years. The suture occasionally persists through life and sometimes the line of junction can be felt in the living; it should not be mistaken for fracture. The frontal eminences in the child are particularly prominent, the forehead projecting beyond the edge of the orbit. This makes it difhcult to apply a bandage securely to the head in children unless it is twisted to draw in its sides. The superciliary ridges are about a centimetre above the edge of the orbit over its inner half. Aided by the hair of the eyebrows they ser\'e to divert the sweat to the sides, as pointed out by Humphr}'. They are best developed in the adult male. Directly between them in the median It is the anterior point from which measurements are taken in cerebral topography. Frontal Sinuses. — Beneath the superciliary ridges are the frontal air-sinuses, but the size of the sinuses is not necessarily proportional to that of the ridges; they may extend quite far back over the orbit. Fractures of the outer wall of these sinuses not infrequently occur without the inner table being injured. A septum separates one sinus from the other, not always in the median line. The lining membrane of these sinuses is often inflamed and suppurates, discharging pus into the nose. Tumors also grow in them. Margins of the Orbit. — At the upper and outer margin of the orbit is the external angular process of the frontal bone. The line of junction or suture between it and the malar bone can be distinctly felt in the living both on the side of the orbit and on the side toward the temple. This is an important landmark in cerebral topography, as it is used to locate the fissure of Sylvius and also the middle meningeal artery. On the upper margin of the orbit at about the junction of its middle and inner thirds is the supra-orbital notch. This can usually be readily felt through the skin. Sometimes it is a complete foramen instead of simply a notch. It is then to be located bv feeling on the orbital surface just behind the edge. It transmits the supra-orbital nerve and artery. The pain is felt above the orbit radiating from the supra-orbital notch, sometimes as far up as the vertex. Pain is also felt on pressure over the supra-orbital notch. If the entire ophthalmic branch of the fifth nerve is aftected, pain is felt in the eyeball and down the side of the nose. The incision in operating may be made at the lower border of the eyebrow, its centre being over the notch. If the notch is not readily felt on the edge of the bony orbit at the junction of the inner and middle thirds, it can be detected by feeling with the tip of the finger on the orbital surface. The incision is made through the fibres of the orbicularis palpebrarum, corrugator supercilii, and frontalis muscles, then through the palpebral ligament immediately below the bony edge of the orbit, and the orbital fat separated with forceps; the ner\^e is then caught with a hook before it enters the notch, and brought up and removed. Considerable ecchymosis may follow this operation if the accom- panying artery is divided. Operations on the ophthalmic division of the fifth nerve have usually been done in connection with removal of the Gasserian ganglion, the other branches being also involved. Nasion. — About a centimetre below the glabella, in the adult skull, is the nasion, or line of junction of the frontal and nasal bones. It is along this frontonasal suture, to one side of the median line, that an anterior meningocele is apt to show itself. The internal angular process of the frontal bone articulates with the nasal process of the superior maxilla and the lachrymal bones. The line of suture is continuous with the nasion in front and the upper edge of the ethmoid behind. Pus originating in the ethmoidal cells, frontal sinuses, and lachrymal apparatus is apt to point at this locality. The frontal bone is a favorite seat of exostoses. THE TEMPORAL REGION. The region of the temple is on the side of the head as far forward as the eye and as low as the zygoma and infratemporal crest. The floor of the temporal fossa is formed by the posterior portion of the frontal and anterior portion of the parietal bones as high as the temporal ridge, the outer surface of the greater wing of the sphenoid, and the squamous portion of the temporal bone. These four bones meet to form the region of the pterion Tsee p. 39 and 42). The anterior edge of the temporal bone overlaps and is superficial to the posterior edge of the sphenoid. The anterior edge of the parietal overlies the posterior edge of the frontal. The upper edges of the temporal and sphenoid overlap the lower edges of the frontal and parietal bones. That the temporal region of the skull is distinctly weaker than other regions is due to the thinness of the bones, and the reason that fractures here are exceptionally dangerous is on account of the middle meningeal artery running through a canal in the bone in this region; so that in cases of fracture the artery is torn and hemorrhage occurs above the dura, which causes compression of the brain (Fig. 56). The infratemporal crest (crista infratemporalis) or pterygoid ridge separates the temporal region above from the pterygoid region below. It is an important landmark in operating on the Gasserian ganglion. temporal region no diploe is found in the bones, so that extreme care is necessary to avoid wounding the dura mater. The trephine may be placed 4 cm. (i}4 in. ) behind the external angular process and 4. 5 cm. (i ^ in. ) above the zygoma to strike the middle meningeal artery. This will be level with or a little above the highest part of the edge of the orbit. Temporal Fascia. — This is the dense fascia covering the temporal muscle; it is formed as follows : The pericranium as it comes down from th^ vault of the skull and reaches the temporal ridge passes under and gives attachment to the temporal muscle. The temporal fascia consists of two distinct sheets of fascia, the superficial one from the superior temporal ridge being attached to the zygoma below and to the malar bone in front; the deeper layer from the inferior temporal ridge covers the temporal muscle, and a short distance above the zygoma divides into two layers, one of which is attached to the outer edge, and the other to its inner edge. The upper or superficial layer of the temporal fascia leaves the bone at the superior temporal ridge and is attached below to the top of the zygoma, blending near the bone with the layer beneath. This is a distinct layer though not always readily demonstrable in dissections. Between the layers above the zygoma is some fat and the orbital branch of the middle temporal artery. Anteriorly the temporal fascia is attached to the posterior border of the malar bone and the temporal ridge of the frontal. The temporal fascia is tough and dense and gives attachment by its under muscle surface lo the temporal muscle. Abscess occurring under the temporal fascia, therefore, does not tend to come to the surface, but sinks downward. It is prevented from making its exit on the face below the zygoma by the parotid gland and masseter muscle, so it passes inward to the pterygoid region and may point in the throat or go down into the neck. whether or not the arteries possess the calcareous deposits characteristic of atheroma. The location of the artery in front of the ear should be remem- that point. The temporal muscle receives blood from the middle temporal artery which comes from the temporal and perforates the temporal fascia just above the zygoma, and from the anterior and posterior temporal branches of the internal maxillary. The temporal fossa is frequently the seat of operations to expose the Gasserian ganglion and the bleeding from these various temporal arteries contributes to their gravity. They are not important. THE REGION OF THE CHEEK. In this region we may include the parts limited above by the zygoma, in front by the eye, nose, and mouth, below by the lower edge of the lower jaw, and behind by the ear. The soft parts of the cheek are supported by the malar and superior and inferior maxillary bones. In disease this fat disappears, hence the hollow cheek of invalids. Swelling occurs readily from contusions and inflammations because the tissues of the cheek are lax. Inflammations may either start in the skin, which is quite prone to disease, or may be the result of inflammation of some surrounding structure, as the parotid gland, the roots of the teeth, the lachrymal sac, eyelids, etc. and the non-malignant as well as the cancerous ulcers of the aged. It is also the seat of noma or cancrum oris. This starts on the mouth surface as a gangrenous stomatitis and implicates the cheek, causing death or great disfigurement owing to the loss of cheek substance. Facial carbuncle or malignant pustule occurs on the cheek, or sometimes on the lips. It is verv often fatal. Wounds and contusions of the cheeks are common, and, as the blood supplv is abundant, bleeding is free and healing prompt. On account of the insertion of the muscles into the skin, gaping is quite marked. The malar bone is the most prominent bone of the cheek. It is such a strong bone and so strongly supported that fracture of it, as well as that of the zygoma, is rare. It may be broken by direct ^-iolence, as being hit with a stone, etc. It is extremely difficult and often impossible to restore the fractured parts to their original level, therefore deformity following fracture is of frequent occurrence. The fracture may invoh'e the margin of the orbit and cause an eftusion of blood mto the orbit, pushing the eye forward. A fracture of the zygoma, if verv much depressed, may interfere Avith the use of the temporal muscle below, necessitating operation. This occurrence is, however, rare. The facial artery runs upward and inward, from a couple of centimetres in front of the angle of the jaw, along the anterior border of the masseter muscle to the angle of the mouth, and thence to the inner canthus of the eye. The anterior edge of the masseter muscle can usually be distinctly felt beneath the skin. At this point the vessel can be ligated or temporarily compressed by passing a pin beneath it and winding a silk ligature above it, around the ends of the pin. This procedure is desirable in some operations on the cheek, as angiomas frequently affect this region. If the facial artery is ligated, the blood supply comes from the superior and inferior coronary arteries of the opposite side; the nasal branch of the ophthalmic, anastomosing with the angular; the transverse facial below the zygoma, from the temporal; the infra-orbital, a branch of the internal maxillary ; and to a slight extent from the inferior labial and others still less important (Fig. 58). The internal maxillary artery, one of the terminal branches of the external carotid, arises in the parotid gland opposite the neck of the lower jaw. This is just below and behind the articulation, which can be readily felt through the skin. — 'I'he internal maxillary artery. passes between the bone and the sphenomandibular (long internal lateral) ligament, then between the two pterygoid muscles or between the two heads of the external pterygoid muscle to the posterior surface of the superior maxillary bone in the sphenomaxillary fo.ssa. The branches of its first part, where it is behind the neck of the jaw, are the deep aiiricjilar, tympanic, middle and small menins;eal, and inferior alveolar {dejital). The branches of its second part, as it passes between the pterygoid muscles, are all muscular : they are the ?nasseteric, pterygoid, anterior and posterior deep temporal, and the buccal. The branches of the third portion of the artery, in the sphenomaxillary fossa, sxg the posterior dental, infra-orbital, desccjidi^ig palatine. Vidian, pterygopalatine , and spheno- or nasopalatine. The main trunk of the internal maxillary artery is not often involved either by injury or operations. The various branches are, however, of considerable importance, as they supply parts which are often the site of operative measures. The importance of the middle meningeal artery in reference to fractures of the skull has already been pointed out. The inferior alveolar gives rise to troublesome hemorrhage when the lower jaw is operated on. The deep temporal branches bleed freely when the temporal muscle is incised in operating on the Gasserian ganglion. The infraorbital is involved in operating on the infra-orbital nerve. The posterior or descending palatine branch descends in the posterior palatine canal, in company with a branch foramen. It causes free hemorrhage in operating on cleft palate. The Vidian and pterygopalatine branches supply mosdy the roof of the pharynx; they bleed when adenoids are removed. The descending and sphenopalatine supply the upper part of the tonsil with blood and may give rise to serious hemorrhage in the removal of the tonsils. In operating on Meckel's ganglion, bleeding from these vessels is free. The nasopalatine runs forward in the nose in the groove on the vomer. It is often the cause of serious nasal hemorrhages in operations on the septum. In removal of the upper jaw, bleeding occurs from many of the branches of the internal maxillary, but it is hardly so free as might be expected, especially if the external carotid has been previously ligated. PAROTID GLAND. The parotid gland lies on the cheek, behind the jaw and below the ear. The limits (Fig. 60) of the gland are important because suppuration may occur in anv portion of its structure. Its extent is as follows : above to the zygoma, lying below its posterior two-thirds; posteriorly, to the external auditory canal, the mastoid process, and digastric and sternomastoid muscles ; below to a line joining the angle of the jaw and mastoid process ; and in front about half the width of the masseter muscle. This latter is, however, quite variable. The parotid duct, also called Stenson'' s dud, leaves the upper anterior portion of the gland about a centimetre below the zygoma and runs on a line joining the lower edge of the cartilaginous portion of the ear with the middle of the upper lip. It opens on a papilla on the inside of the cheek opposite the second upper molar tooth. This papilla can readily be seen and a fine probe can be inserted from the mouth into the duct; thus the presence of a calculus mav be detected. In operating on the cheek the line of this duct must be borne in mind, as wounding it mav cause a salivary fistula. Wounds of the lobules of the gland are not nearly so liable to result in fistula as those of the duct itself. Parotid Fascia. — The gland is covered by the parotid fascia. This fascia is moderately dense and is continuous with the fascia separating the lobules of the gland. Above it is attached to the zygoma ; in front it is continuous with the masseteric fascia over the masseter muscle ; and below and posteriorly it is continuous with the deep fascia of the neck. It stretches from the angle of the jaw to the sternomastoid muscle and somewhat deeper to the styloid process ; the band running from the styloid process to the lower jaw is called the stylomandibular ligament. From thence it is continued over the internal carotid artery and the upper surface of the internal pterygoid muscle. Lobes of the Parotid Gland. — The gland has extentions in various directions (Fig. 6i). A prolongation behind the articulation of the lower jaw, into the posterior portion of the glenoid cavity immediately in front of the external auditory canal, is called the glenoid lobe. Another extension winds around the posterior edge of the lower jaw on the lower surface of the internal pterygoid muscle and is called "Ca^ ptery- goid lobe. A prolongation inward, passing between the external carotid on the outside and the styloid process and the internal carotid artery on the inside, is called the carotid lobe. A separate portion of the gland, sometimes quite detached, lies at its upper anterior portion between the zygoma and the duct of Stenson; it is called the socia parotidis. Vessels and Nerves Traversing the Gland. — The external carotid artery enters the gland to divide opposite the neck of the lower jaw into the temporal and internal maxillary. The temporal, before it leaves the gland, gives off the transverse facial artery which runs forward on the face between the zygoma and parotid duct. It is usually small but at times may be quite large and even go over to the angle of the mouth and form the two coronary arteries (as shown in M'Clellan's "Regional Anatomy" ). The temporal vein, as it descends into the gland, is joined by the internal maxillary vein to form the temporomaxillary vein, which, after it receives the posterior auricular vein, goes to form the external jugular. The facial nerve emerges from behind the jaw just below the lobe of the ear and divides into its various branches while still in the gland. There is usually a large branch passing parallel to the duct of Stenson and below it. The auriculotemporal nerve follows the temporal artery, emerging from the gland a little posterior to the artery. Dr. Skillern has shown that, by injecting it with cocaine, operations on the walls of the meatus externus for furuncles, etc. , can be rendered painless. The auricularis magnus from the second and third cervical supplies the skin over the gland. be involved in general disease of the cervical lymphatics. Affections of the Parotid Gland. — The duct may be affected with calculus, as already mentioned. As the opening of the duct at the papilla is smaller than the lumen of the canal farther back, calculi are apt to lodge close to the anterior extremity. They are, therefore, readily felt and removed by incision on the inside of the mouth. The gland proper is subject to inflammations and tumors. Simple parotiditis or mumps really is an infectious inflammation, ne\-erthele5s, it rarely suppurates. Suppurative parotiditis may occur from infected wounds or arise in the course of the eruptive fevers, etc. In inflammation of the gland, pain and swelling are important symptoms. The pain, which is considerable, is not due so much to the so-called dense parotid fascia covering the gland, for this is only moderately thick, as it is to the fact that the gland is of a racemose type and the fibrous septa between the lobules are abundant and prevent free expansion of the contained lobules. Expansion is also hindered by the peculiar location of the various parts of the gland. Swelling of the glenoid lobe produces pain in the ear and also in the temporomaxillary articulation. Swelling of the carotid and pterygoid lobes causes pain and fulness in the throat. Opening the lower jaw reduces the space posterior to it in which the gland lies and pinches it against the bony meatus and mastoid process, so that it is impossible to open the jaw widely. If suppuration occurs it is liable to progress from one lobule to another; when this is the case comparatively small abscesses may appear in different parts of the gland with unaffected tissue between them. As an abscess heals in one lobule, suppuration is apt to occur in another, consequently the disease may persist for a long time. More rarely in the course of or following infectious diseases, particularly in debilitated patients, considerable portions of the gland may slough. This foim is apt to be fatal. If the suppurating focus is confined to lobules which are deeply placed, the diagnosis may be obscure because it is difficult to localize the affected spot. If, however, it is near the surface of the gland, the pus does not tend to extend sideways, the fibrous septa prevent this, but it tends to work its way up and perforate the skin. If the glenoid lobe is affected, the pus may find an exit through the external auditory meatus or even involve the temporomaxillary joint. If the carotid or pterygoid lobes are affected, the pus may go between the pterygoid muscles, or around the internal carotid artery and project and open into the pharynx. It may also break into the carotid artery or jugular vein, or perforate through the fascia below and go down the neck. Large abscesses and sloughs may be followed by a parotid fistula. Lines of Incision for Abscess. — The manner of opening a parotid abscess depends on its location and size. If it is desired to open an abscess anterior to a point 1.5 cm. or about half an inch in front of the ear, the structures to be avoided are the duct and facial nerve. The incisions are to be made parallel to the zygoma, and the duct is to be avoided by not cutting on a line joining the lower edge of the cartilage of the ear with the middle of the upper lip. The branches of the facial nerve lie deep and are to be avoided by making the incision parallel to their course and not extending it too deeply. After incising the skin, the deeper tissues may be separated by introducing a pointed pair of haemostatic forceps and opening the blades. In operating in the region below the ear, the blood-vessels are to be avoided. To do this incise the skin longitudinally, not transversely, and open- the deep parts carefully with the haemostatic forceps, as already described. Another method, when the abscess is farther forward, is to make a horizontal incision rather low down on the angle of the jaw and then introduce a grooved director or haemostatic forceps from below upward. Tumors of the parotid gland are liable to be mixed in character, with a sarcomatous element. They are often fairly circumscribed and, particularly if they do not involve the parotid duct, can be removed comparatively readily. If they are malignant and large, complete removal is practically impossible. The possibility of parotid fistula and paralysis of the facial nerve following operation on this gland should always be borne in mind and explained to patients. The presence of facial paralysis is indicative of malignancy (see Fig. 63). 'i"he parotid lymph nodes on or beneath the capsule may become enlarged and inflamed and resemble true parotiditis. There is one node just below the zygoma and in front of the ear that is not infrequently enlarged in strumous children. This is apt to be involved when aftections of the lids or scalp are present. In opening abscesses of these nodes there is little likelihood of injuring either the nerve or the duct, because the nodes are superficial. The transverse facial artery is usually too small to cause trouble. The possibility of its supplying the coronary arteries of the lips, as already described, in which case it would be very large, should be remembered. THE UPPER JAW. The upper jaw carries the upper teeth and contains the maxillary sinus or antrum of Highmore. The aft'ections of the antrum will be alluded to in the chapter on the nose (see page 103). F"ractures of the superior maxilla involve the nasal process, the alveolar process, or pass transversely through the body of the bone. The nasal process is sometimes broken in fractures of the nose. In this injury, the lachrymal canal and sac may be injured and the flow of tears through them prevented, causing the tears to run over the cheek. Fractures of the alveolar process are common enough as a result of blows and extracting teeth. These fractures, as they communicate with the mouth through the broken gums or mucous membrane or tooth socket, are necessarily compound, and consequently become infected from the mouth and suppurate. This may cause necrosis of the fragment, but the blood supply of the jaws is so good that death of a fragment is rare, and it is not customary to remove fragments not completely detached. The front wall is sometimes driven in. Fractures occasionally occur in which the line passes through one or both superior maxillary bones from below the malar bone into the nose. If this fracture passes completely backward, it detaches the lower portion of the palate bone and pterygoid processes of the sphenoid bone. The fragment in such cases has a tendency to slip backward. It can be replaced by inserting a hook through the mouth and behind the soft palate and pulling the fragment forward. This injury is produced by a blow on the anterior portion of one or both bones, passing downward and backward. In order to determine the existence of fracture, Guerin recommended inserting the finger in the mouth and feeling for the pterygoid plates. The hamular process of the internal pterygoid plate can readily be felt about one centimetre above and behind the last upper molar tooth. Fractures in the neighborhood of the first and second molar teeth are liable to open the antrum, as the roots of these teeth project into it. Resection of Upper Jaw. — Tumors of the antrum may necessitate a resection of the superior maxilla of one side. Heyfelder was the first to remove both superior maxillse, in 1844: this was before the discovery of anaesthesia. In removing one superior maxilla, the incision known as Fergusson's is used. This is made through the middle of the upper lip, around the ala of the nose to the inner canthus of the eye, thence outward along the lower border of the orbit to the malar bone. The bleeding from this incision is free. The coronary arteries should be looked for near the mucous surface of the lip toward its free edge. Bleeding will also occur from the lateralis nasi and the angular arteries. The soft parts are raised from the bones as far back as the masseter muscle. This is just about level with the outer edge of the bony orbit. In doing so the infra-orbital nerve and artery will be divided. The artery is not large but may bleed freely. The fibrous floor of the orbit is raised and the attachment of the inferior oblique muscle loosened. The malar bone is sawed downward and outward opposite the sphenomaxillary fissure, and the division completed with forceps. The nasal portion of the superior maxilla is sawed through from the orbit into the nose. The soft parts of the roof of the mouth are divided in the median line to the posterior edge of the hard palate, and thence along its edge to the last molar tooth. The soft palate is firmly attached to the hard palate and has to be detached with scissors. An incisor tooth is then drawn, and the bony palate sawed through from the nose into the mouth. The bone with the tumor is wrenched loose with lion-jawed forceps. The union between the posterior portion of the superior maxilla and the pterygoid processes of the sphenoid is not bony, but fibrous, so that the bone is torn away from the processes and the latter are left behind. As the bone comes away, the maxillary nerve should be cut. The bleeding Avhich follows is from the infra-orbital, superior alveolar (posterior dental), and posterior palatine arteries, branches of the internal maxillary. It is not so free as might be expected, provided preliminary ligation of the external carotid has been performed. It will be observed that the facial nerve is not touched nor is the parotid duct wounded. eye to the mouth and as far forward as the median line, also the upper gums and Fig. 64. — Resection of the upper jaw. The curved Hnes indicate the skin incision and the straight lines where the bones are to be divided. hard palate. The operations devised for its relief are both numerous and intricate, and necessitate an accurate anatomical knowledge of the parts. The maxillary nerve is the second division of the fifth cranial nerve. It leaves the skull cavity by the foramen rotundum, then crosses the sphenomaxillary fossa, enters the sphenomaxillary fissure and infra-orbital canal to emerge on the cheek, opposite the middle of the lower edge of the orbit and about 6 mm. below it. The intracranial portion is 6 to 8 mm. in length. From the sphenomaxillary fossa to the infra-orbital foramen is about 5 cm. ( 2 in. ). Its branches are as follows: one or two small branches to the dura mater, the orbital or sphe)wmala,r branch to the cheek and anterior temporal region, sphenopalatine branches going to Meckel's ganglion, the posterior, middle, and anterior dental to the upper teeth, and the terminal branches, labial, nasal, and palpebral, on the face. Its anterior portion has been removed through an incision on the face, and its posterior portion with Meckel's ganglion has been operated on either anteriorly through the maxillary sinus or laterally through the temporal fossa, after removing the zygoma. The writer has removed the intracranial portion by entering the anterior cerebral fossa through the temporal region. Removal of the infra-orbital portion of the nerve is so liable to be followed by recurrence of the pain and interferes so much with the more complete procedures, as it destroys the guide (the nerve itself) which leads the operator to Meckel's ganglion, that it is doubtful whether it should ever be resorted to. The posterior dental branches are gi\en off so far back that they are not apt to be removed in this operation. Removal of the Infra-orbital Nerve. — An incision 3 cm. in length is made along the lower edge of the orbit. This divides the orbicularis palpebrarum muscle. Arising from the bone, between the infra-orbital foramen and the edge of the orbit, is the levator labii superioris muscle. This should be carefully detached, and the foramen with its artery and nerve will be found opposite the middle of the lower edge of the orbit and about 6 mm. f ^ in. ) below it, on a line drawn from the supra-orbital notch to between the premolar teeth. The position of the foramen having been located, the palpebral ligament and periosteum are divided and the contents of the orbit raised. The canal is next to be opened. This can be done either by chiselling away its roof from the opening on the face and following it backward or by breaking through its upper wall. This latter procedure is liable to give trouble, because if the track of the canal is not encountered the instrument breaks into the maxillarysinus, the roof of which is very thin. The infra-orbital canal does not pass directly backward but backward and outward, striking the sphenomaxillary fissure about 2 cm. (in a large skull) behind its anterior extremity. Sometimes the roof of the canal is fibrous, in which case the groove so formed can be readily felt, but in others it is bony. The nerve is hooked up and cut as far back as one can, so as to remove, if possible, the posterior dental branches. The terminal branches are then pulled off from the cheek, and the nerve drawn out from the front. It is in the highest degree desirable to avoid wounding the artery, as death is said to have followed it, and there may be bleeding into the orbit, causing protrusion of the eye and serious interference with its sight. A better vvay of removing the nerve, the method of Thiersch ( Verhand. der Deutschen Gesell. filr Chir., i8 Congress, Berlin, 1889, p. 44), is to grasp it with a pair of slender, curved forceps, then by rotating the forceps very slowly (about i turn a minute) both the distal and proximal ends are wound around it and an extremely long portion of the nerve can be removed. Removal of Meckel's Ganglion, — Operating from the front through the maxillary sinus (Carnochan's operation, or removal of the sphenopalatine (Meckel's) ganglion and maxillary nerve). — The incision is V-shaped, the apex being 2 cm. above the angle of the mouth, and the branches 3 cm. long. This flap should consist of all tissues down to the bone. The bleeding will be free, as the facial vein and branches of the facial artery will be cut. As the infra-orbital foramen is reached, the nerve is detached from its under surface. The anterior wall of the maxillary sinus, which is quite thin, is broken with a chisel for an extent of 2 cm. The infra-orbital canal is opened from below, from the surface clear back to the posterior wall of the sinus. The infra-orbital nerve is then brought down into the sinus to serve as a guide to the foramen rotundum. Care should be taken (by opening the canal with comparatively blunt instruments) not to wound the infra-orbital artery. Then break a hole in the posterior wall of the sinus. This is very thin, and not over half a centimetre (\ in. ) intervenes between it and the anterior wall of the sphenoidal sinus, so that care should be taken not to drive the chisel too far back. The posterior wall having been broken with the chisel and the pieces picked away, the nerve is dragged downward, freed as far back as possible, and pulled loose. Traction on the nerve brings the ganglion forward, and with forceps it is then drawn out. The bleeding, after breaking through the posterior wall of the sinus, may be very free. Meckel's ganglion lies in the sphenopalatine fossa just below the maxillary nerve after it leaves the foramen rotundum. Two short branches unite the ganglion and nerve. It is here that the internal maxillary artery, in the third part of its course, divides into six branches: the infra-orbital and posterior dental, the posterior or descending palatine and Vidian, and the pterygopalatine and spheno- or nasopalatine arteries. If these arteries are wounded, as they are very apt to be, the bleeding is very free. To control it temporary packing is at first resorted to. If it persists, the nerve is removed as well as possible and the bleeding stopped with gauze. This may be firmly packed into the opening through the posterior wall at the upper inner portion of the sinus, but care should be taken not to push it roughly through the fossa and into the sphenoidal sinus (or cells) beyond. J. D. Bryant (^Operative Surgery, vol. i, p. 243) in cases of severe hemorrhage advises the prompt ligation of the external carotid artery, a procedure not, however, often required. It has been suggested that instead of making the incision on the cheek to make it in the mouth above the gums, and pull the cheek and mouth upward and outward. This procedure, while obviating the scar, makes the operation somewhat more difficult. Kocher resects the malar bone with the outer wall of the sinus and turns it up, bringing it back into place on the completion of the operation. Operating from the Side Through the Pterygoid Fossa. — Both the maxillary and mandibular branches have been reached by this route; the former at the foramen rotundum and the latter at the foramen ovale. LUcke, of Strasburg, Vv^as the pioneer of the operation on the maxillary nerve, and Joseph Pancoast, of Philadelphia, on the mandibular. LUcke' s operation was modified by Lossen, of Heidelberg. Recently, Mixter, of Boston, has again advocated the method. A convex flap, base down and reaching ^ inch below the zygoma, is cut from the external margin of the orbit to the lobe of the ear. The zygoma is sawed through, and, with the masseter, pulled downward. Maurice Richardson, in describing Mixter's operation {Internat. Textbook of Surg., vol. i, p. 863), says that "if- the operator is skilled enough in the subsequent manipulations, he may omit cutting the temporal muscle." It will be easier, however, to divide the coronoid process and turn the temporal muscle upward, clearly exposing the infratemporal crest. Detach the upper head of the external pterygoid muscle and push it downward, exposing the external pterygoid plate. Chisel off the spur at the anterior extremity of the infratemporal crest, and immediately in front and to the inner side is the superior maxillary nerve, with the terminal portion of the internal maxillary artery just below it. Immediately posterior to the root of the pterygoid plate is the foramen ovale and mandibular nerve, with the middle meningeal artery a little posterior to it. Anatomical Comments. — The incision at its posterior extremity can be made to avoid cutting the temporal artery by feeling its pulsations, about a centimetre or less in front of the ear, as it passes over the zygoma. The incision should not involve the deep structures — only tlie skin and superficial fascia. Therefore, the facial nerve and parotid duct (a finger's breadth below the zygoma) will not be injured. artery may be encountered and may bleed. The temporal muscle arises not only from the deep layer of the temporal fascia, but may also be attached anteriorly to the inner surface of the zygoma, and in loosening it free bleeding from the deep temporal arteries, branches of the internal maxillary, may be encountered. No trouble need be expected in sawing through the anterior end of the zygoma, but care should be taken not to injure the parotid duct, or the socia parotidis if it is present. In making the division of the posterior end of the zygoma, one must guard against opening the temporomaxillary articulation, for, when the head of the_ mandible is back in the glenoid fossa, the 'capsule of the joint extends considerably in front of it. Therefore, it is better to open the mouth and push the jaw on that side forward until it rides on the eminentia articularis, then the anterior limit of the joint can be recognized and avoided. Before one can reach the spur on the anterior extremity of the infratemporal crest, the temporal muscle must be detached from the bone. The Zygoma Fig. 67.— Operating through the pter>-goid fossa. The skin with the zygoma and masseter have been turned down. The coronoid process is divided and turned up. The upper head of the e.xternal pterygoid has been detached and turned down. The maxillary ner\e is in front of the pter>'goid plate (processus pterygoideus) and the mandibular nerve and middle meningeal artery just behind it. upper head of the external pterygoid muscle arises from the bone just below the pterygoid ridge (infratemporal crest j, and must be loosened from the bone to obtain access to the nerves (see Fig. 67). The coronoid process rises almost as high as the infratemporal crest, and, therefore, in order to gain space it will be necessary to depress the jaw. Running upward and inward over the internal pterygoid muscle, and passing just in front of the origin of the upper head of the external, is the internal maxillary artery and pterygoid plexus of veins. These vessels lie directly below the maxillary nerve as it crosses the sphenopalatine fossa, and it is to be expected that free hemorrhage will accompany the attempt to fish out the nerve. require the ligation of the external carotid artery. Intracranial operations are hardly ever done for maxillary neuralgia alone. The mandibular and often the ophthalmic divisions are also usually affected ' in cases requiring to be approached from the inside of the skull. Excision of the Lingual and Inferior Dental Nerves. — Neuralgia involving the face below the line of the mouth, the lower teeth, and side of the tongue requires the remo\"al of the inferior dental and lingual ner\'es. To do this, a curved incision following the lower edge of the mandible is made. It ends anteriorly in front of the mandibular foramen, and posteriorly it stops a centimetre below the ear to avoid wounding the facial nerve. The masseter muscle is raised from the bone, and, with the parotid gland, is drawn up. The ramus of the jaw is trephined in its middle, rather high up toward the coronoid notch. The outer table of bone is then to be chiselled off, from the trephine opening as far down as the mental foramen. A delicate, curved, haemostatic forceps is then made to graSp both nerves through the Operations on the Gasserian Ganglion. — The Gasserian ganglion lies in its capsule, formed by a splitting of the dura, on the anterior surface of the apex of the petrous portion of the temporal bone and on the root of the greater wing of the sphenoid. From its posterior extremity, which rests on the ridge separating the anterior and posterior surfaces of the petrous portion of the temporal bone, to the foramen rotundum anteriorly is 2.5 to 3 cm. (i to i}( in.). The foramen ovale, which transmits the third or mandibular branch is midway between these two points, and corresponds on the outside of the skull to the eminentia articularis or root of the zygoma. Therefore, in removing the ganglion one works not only inward but also backward. Rose first operated on the ganglion from below. He remo\ed the zygoma and coronoid process, Hgated the internal maxillary artery, and trephined the skull in front of the foramen ovale. This operation was succeeded by that of Hartley and Krause. They went in through the temporal fossa. A large horseshoeshaped flap, with its base abo\'e the zvgoma, was cut and deepened with chisels through the bone to the dura. This was elevated by breaking across its base, and turning it down. The dura was then lifted from the base of the skull, and the maxillary and mandibular nerves recognized as they passed into the round and oval foramina. The capsule having been incised, these were seized with forceps, and as much of the ganglion as possible torn away. embraced the region of the pterlon or junction of the coronal with the temporosphenoidal sutures. As the bone was Hfted from the dura at this point the middle meningeal artery was torn and troublesome bleeding ensued. Also the point of its breaking was too uncertain. Sometimes it broke too high up, sometimes too low down involving the base. It was also found unnecessary to replace the bone as the cavity left was filled up with fibrous tissue. For this reason Tiffany, of Baltimore, advocated the making of an opening in the skull above the zygoma with a trephine or gouge and mallet, and enlarging it with the rongeur forceps; the bone was not replaced. This is the procedure now used. The operators who used the pterygoid route, by displacing the zygoma downward, were enabled to approach the ganglion from below instead of from above, therefore, a high temporal section of the bone was unnecessary and it has been abandoned; the bone section keeping below the pterion and not wounding the middle meningeal artery thus avoids hemorrhage from that locality. Gushing (Journ. Am. Med. Assoc, April 28, igoo) showed that the extensive removal of bone on the base of the skull was unnecessary, and that a displacement of the zygoma and temporal muscle downward, and removal of the bone down to and including part of the infratemporal crest gave sufihcient access. Murphy found it unnecessary to resect the zygoma, and this has been our experience. One of the main difficulties has been the question of bleeding. It has caused death and not infrequently has necessitated the packing of the wound and the deferring of the completion of the operation for two or more days. This bleeding came from the soft parts, the bone, the middle meningeal artery, the veins running from the dura mater to the bone, the cavernous sinus, and. the blood-vessels to the ganglion itself. These as given by Gushing are a branch from the middle meningeal soon after its entrance to the skull, a small branch from the carotid, a small branch from the ophthalmic, the small meningeal through the foramen ovale, and occasionally one through the foramen rotundum. He calls attention to the septa in the cavernous sinus as rendering wounds to it less serious than they otherwise would be. If the skin incision is cast too far back, the temporal artery may be cut in front of the ear. Its position can be determined by its pulsation. It or its branches are divided in the upper portion of the incision and bleeding is very free. Division of the temporal muscle is followed by hemorrhage from the deep temporal. The bleeding from the bone is usually not troublesome, but the general oozing from the veins of the dura mater as it is detached from the bone is sometimes free. If an osteoplastic (bone and skin; flap is raised, the middle meningeal will be torn at the pterion. This is a large vessel and bleeds freely. It may also be torn, while isolating the mandibular division of the nerve, at the foramen spinosum. This foramen is usually a couple of millimetres posterior and to the outer side of the foramen ovale and generally the nerve can be isolated without injuring the artery. In some cases, however, the artery lies so close to the ner\-e that it is almost certain to be torn. The posterior portion of the ganglion lies on the carotid artery in the middle lacerated foramen, of course separated by a layer of dura mater. Care should, therefore, be taken not to injure the carotid artery. The cavernous sinus has often been injured. This occurs principally in those cases in which it is attempted to excise the ophthalmic division. It is to be avoided by working from behind forward instead of attempting to attack it laterally. Bleeding from the middle meningeal artery can be Gushing states that he makes an opening in the bone only 3 cm. in diameter. Such a small opening is used when the zygoma has been divided and pushed down or removed. Fowler and others have resorted to a preliminary ligation of the external carotid artery. This, while obviating to a great extent troublesome hemorrhage, cuts of? the blood supply to the flap and sloughing has followed. In order to overcome this objection, the writer {Jojcrn. A))i. Med. Assoc, April 28, 1900) after ligating the external carotid artery above its posterior auricular branch made a temporal skin flap with its base up. The temporal muscle was then divided and turned down and the bone removed with the trephine and rongeur. Haemostasis was perfect and no ill eflects followed the ligation. It is comparatively easy to isolate the maxillary and mandibular divisions of the nerve. This having been done, the capsule of the ganglion is opened by a cut joining the two. A blunt dissector is then introduced and the upper layer of the dura, less adherent than the lower, is raised from the ganglion. The blunt dissector is then worked beneath the ganglion beginning between the maxillary and mandibular divisions and it is loosened from behind forwards. The sixth nerve is in such close relation to the ophthalmic that a temporary paralysis of it usually follows, causing internal squint. Frazier and Spiller have divided the root posterior to the ganglion instead of removing the ganglion itself {Joiirn. Am. Med. Assoc, Oct. i, 1904, p. 943). Area of Distribution of the Fifth Nerve. — When the ophthalmic division is affected the pain in neuralgia is over the brow and up toward the vertex of the skull; it also involves the eye. The points of exit of the supra-orbital branch at the supra-orbital foramen and of the nasal branch toward the lower portion of the nose are tender to pressure. When the maxillary division is affected, there is pain in the cheek and ala of the nose. The tender points are the exit of the infra-orbital nerve at and below the infra-orbital foramen, at the exit of the malar branch on the malar bone, and tne upper gums and hard palate. When the mandibular division is affected the pain involves the lower jaw and the side of the head nearly to the top (auriculotemporal branch). The lower gums and tongue are also painful. Pain on pressure is felt over the mental foramxcn and in the course of the auriculotemporal nerve in front of and above the ear. The mandible or inferior maxilla is subject to fractures, dislocation, and tumors. In its composition it is very dense, so that in dividing it a groove should be cut with a saw before the use of the bone-cutting forceps is attempted, otherwise splintering of the bone will ensue. It is the last bone to decay. Its horseshoe shape and exposed position render it unusually liable to fracture. The strongest portion is what one would expect to be the weakest, viz., the symphysis. Its weakest part (or rather the part where it is most often broken) is the region of the mental foramen. The bone is weakened at this point not only by the foramen but also by the deep socket of the canine tooth. The position of the mental foramen, normally between the two bicuspids (beneath the second in the negro — Humphry), varies in its vertical location between the alveolar border and lower edge of the body, according to age. In infancy it is low down, in young adults it is midway, and in old people it is high up. The body of the jaw is composed of two parts, one above and one below the external oblique line, which runs from the base of the anterior border of the coronoid process downward and forward to end at the mental tubercle, to one side of the symphysis. The part above this oblique line is the alveolar and the part below is the basal portion of the body. The mental foramen opens on the oblique line separating the alveolar and basal portions. In early adult life the two portions, basal and alveolar, are about even in size, so that the foramen is below the middle of the jaw. As the teeth are lost the alveolar process atrophies; this naturally leaves the basal portion with the mental foramen on or near its upper surface; therefore, in operating for neuralgia in the aged, if it is desired to attack the mandibular nerve in its canal, it should be searched for near the upper border of the bone. In infancy the teeth, not having erupted, are contained in the jaw, the alveolar portion is, therefore, large. The basal portion, on the contrary, is quite small, serving merely as a narrow shelf on which the unerupted teeth lie. As the mandibular nerve runs beneath the teeth, the mental foramen is of necessity comparatively low. At birth the condyle is about level with the upper portion of the symphysis, and the body forms with the ramus an angle of 175 degrees. At the end of the fourth year the angle has decreased to about 140 degrees. By adult age the angle has decreased to about 115 degrees, and as the teeth are lost the angle gradually increases until it again reaches 140 degrees. The mandible articulates with the glenoid fossa and its anterior edge or eminentia articularis of the temporal bone. Interposed between the condyle below and the bone above, is an interarticular cartilage. This divides the articulation into two portions, an upper and a lower. The ligaments are a capsular, strengthened by an external lateral (temporomandibular) and an internal lateral. The capsular ligament is weakest anteriorly and strongest on the outer side. The thickening of the capsule on its outer side forms the external lateral or temporomandibular ligament. The sphenomandibular or internal lateral ligament is practically distinct from the articulation. It runs from the alar spine on the sphenoid above to the mandibular spine or lingula, just posterior to the mandibular foramen below. Between it and the neck of the bone run the internal maxillary artery and vein. When the condyle glides forward it puts the posterior portion of the capsule on the stretch, and if the jaw is dislocated this part of the capsule is torn. The interarticular cartilage is more intimately connected with the lower portion of the articulation. The same muscle that inserts into the neck of the jaw (the external pterygoid) likewise inserts into the cartilage ; therefore, the two move together, so that when the condyle goes forward the cartilage goes forward and rides on the eminentia articularis. the mandible. Movements of the Jaw. — The jaw has four distinct movements. It can be moved directly forward or backward; up and down, a pure hinge motion; a rotarymovement on a vertical axis through one of the condyles; and rotation on a transverse axis passing from side to side through the mandibular or inferior dental foramina. The muscles of mastication are the temporal, masseter, and pterygoids ; these are supplied by the motor branch of the fifth nerve. To these we may add the buccinator, which is supplied by the seventh nerve, and the depressors of the jaw, — the digastric, geniohyoid, geniohyoglossus, mylohyoid, and platysnia. The posterior belly of the digastric receives its nerve supply from the facial ; its anterior belly from the mylohyoid branch of the inferior dental from the fifth. The mylohyoid is supplied by the mylohyoid branch of the inferior dental. The geniohyoid and geniohyoglossus are supplied by the hypoglossal nerve. The platysma is supplied by the inframandibular branch of the facial nerve. The upward movement is produced mainly by the masseter and temporal muscles. It is the principal movement in carnivorous animals ; therefore, these muscles in them are well developed, and the joint is a pure hinge joint. The internal pterygoid and buccinator likewise aid in closing the mouth ; the depressors already mentioned open it. The lateral or rotary movement around a vertical axis passing through one condyle is used in chewing ; therefore, we find the muscles most concerned, the pterygoids, best developed in herbivorous animals, or those which chew the cud. The external pterygoid is especially efficient in pulling the jaw forward ; superficial fibres of the masseter help in this. The posterior fibres of the temporal muscle pull the jaw back, as do likewise the depressor muscles of the jaw. In this rotary movement one condyle remains back in its socket while the other is brought forward on the eminentia articularis. The up-and-down movement of the jaws, when limited in extent, is a pure hinge movement without any anteroposterior displacement, and takes place between the condyle and the interarticular cartilage (Fig. 74). The anteroposterior movement is necessarily accompanied by a slight descent of the jaw, as the condyle glides from the glenoid cavity (Fig. 75) onto the eminentia articularis. It goes nearly, but not quite, to the highest point of the articular eminence. If the jaws are kept closed during this anteroposterior movement, some of the teeth of the upper ^nd lower jaws will still be in contact, the number varying in different individuals. so that as they glide forward the last lower molars strike the second upper ones. The incisors likewise can be kept in contact as the jaw moves backward and forward. It is this movement in the rodent animals which keeps their edges sharp. In chewing, the jaw is depressed, the teeth separated, and the food held between them by the tongue and buccinator muscle. The teeth are then approximated by the lower jaw closing and the condyle sliding upward and backward from the eminentia articularis into the glenoid ca\-ity, carrying with it the articular cartilage. The hinge motion takes place between the condyle and the interarticular cartilage. The anteroposterior motion takes place between the interarticular cartilage and the eminentia articularis: the cartilage is carried forward with the mandible. A rotary movement occurs when, in chewing, the condyle of one side remains in the glenoid cavity while that of the other rises on the articular eminence. The radius of rotation is a line passing from one condyle to the other. In widely opening the mouth, as in vawning, the condvles are tilted forward while the angles of the mandible are carried somewhat backward. As the axis of this motion passes from side to side through the mandibular foramina, this portion of the bone moves but little, and the inferior dental vessels and nerve are not put on the stretch. Dislocatio'n of the Lower Jaw. — The forward dislocation is practicallv the only one to which the jaw is subject. Dislocations in other directions are apt to be accompanied by fractures. An understanding of the mechanism of the production and reduction of this dislocation requires a knowledge of the movements of the jaw, and the influences which the ligaments and muscles exert in limiting them. The normal movements of the jaw have already been discussed. The ligaments which limit the movements of the jaw are those forming the ca/>sidar liii^anient. This is made up of four parts: anterior, posterioi', internal lateral, and external lateral. The anterior is very weak, hence pus in the joint is most apt to make its exit forwards. It is readily ruptured in dislocations. The posterior ligament, though stronger, may also be torn. The two lateral ligaments, the outer being the stronger, become tense when the condyle slips forward on the articular eminence. In dislocation they remain attached to the mandible and are not ruptured (see Fig. 76). Dislocation occurs when the mouth has been widely opened and the condyles are forward on the articular eminences. Some sudden jar accompanied by contraction mainly of the external pterygoid muscle causes the condyle to slip forward just in front of the articular eminences. The pterygoid muscles and the superficial fibres of the masseter muscles aid in producing the luxation. As the condyle leaves the articulation to jump forward, it will be noted that it does so by an extensive movement, which is one of rotation on a transverse axis passing across in the region of the mandibular foramina. The condyle once out of its socket is kept out by the contraction of the temporal, masseter, and internal and external pterygoid muscles. Reduction of Dislocation of the Lower Jaw. — In reducing the dislocation, the condyles must be depressed and pushed back. This can be done by one of two ways: viz., the thumbs of the surgeon, being protected by wrapping with a towel or bandage, are placed on the last molar teeth, and the jaw firmly grasped with the fingers beneath it. The back part of the jaw is then pressed downward, the chin tilted upward, and the condyles slid back into place. transversely, between the last molar teeth, then raise the chin and push it backward. The undetached lateral ligaments are put on the stretch when the condyle is luxated forward. Lewis A. Stimson believes that in attempting reduction the jaw should first be opened wider to relax these and then pushed back, but we are not prepared to admit that so doing does relax these ligaments. He has, however, shown that the interarticular cartilage may become displaced and, by filling up the articular cavity, prevent a proper reduction. In rare instances the catching of the coronoid process beneath the malar bone may hinder replacement. Fractures of the Lower Jaw ^Mandible). — Fractures of the lower jaw almost never occur through the symphysis; this is on account of its being the thickest and strongest part of the bone. When a fracture of the anterior portion of the jaw detaches a median piece a most dangerous condition is produced. The piece, if sufficiently loosened by the injury, is drawn back into the throat, carrying the tongue with it and tending to suffocate the patient. Such a case is recorded by A. L. Peirson (review by Geo. W. Norris, Amer. Jour. Med. Sciences, 1841, N. S. vol. i, p. 186). A man was run over by a wheel which passed over his jaw, fracturing it on each side and forcing the piece into his mouth. The piece was drawn backward and nearly caused death from suffocation. In the Amia/s of Surgery (vol. xix, 1894, p. 653) is recorded a case of the author's in which a man, while drunk, fell and struck his chin on the curbstone. A fracture was produced through the symphysis above and branching to each side cf the g-enial tubercle below. This small median piece was drawn back into the throat nearly to the hyoid bone, and suffocative symptoms were marked. These disap- peared when the detached piece was drawn forward and wired in place. The piece was drawn backw^ard by the geniohyoid and geniohyoglossus muscles. The digastrics may also have aided in depressing the fragment (Figs. 77 and 78). The most usual site of fracture is in the neighborhood of the mental foramen. This is located just below the second premolar tooth (sometimes between the first and second). This foramen and the large socket for the canine tooth farther ence of the muscles in producing displacement. forward weaken the bone somewhat in this region. The jaw is strengthened behind the mental foramen by the commencement of the anterior portion of the ramus and by an increase in the size of the mylohyoid ridge on the inner surface. This constitutes the typical fracture of the lower jaw (Fig. 79). Fig. 80. — Fracture of the lower jaw, showing the line of fracture proceeding downward and backward, favoring displacement. Displacement. — The displacement of the fragments will depend on the line of fracture; and the line of fracture may be determined by the direction and character of the fracturing force. The line of fracture is oblique. It may be oblique from above down or from without in. An examination of the muscles attached to the mandible will show that the ele\'ators of the jaw are attached to it posteriorly and its depressors anteriorly. On this account, when the fracture runs obliquely down and forward there is little or no displacement, because the depressors and elevators tend to press the fragments together. \\^hen the fracture runs downward and backward (see Fig. 80), the depressors and elevators tend to separate the fragments. The depression of the anterior fragment is particularly marked when the fracture is double, invohdng both sides of the jaw. The muscles which tend to depress the anterior fragment are the geniohyoglossus, geniohyoid, mylohyoid (anterior portion), digastric, and platysma. The muscles which elevate the posterior fragment are the temporal, masseter, buccinator, and internal pterygoid. The displacement may not only be up and down, but may also be lateral. The line of fracture may run from the outside either inward and backward or inward and forward. The jaw is held in place by its own rigidity when intact ; when broken, the smaller fragment is liable to be pulled inward by the muscles passing from it toward the median line. These muscles are the internal pterygoid and the mylohyoid. The influence of the former is more marked than of the latter, because the fracture frequently divides the mylohyoid. lea\-ing a part of it attached to each fragment. When the fracture passes from without inward and backward, then there will be little or no displacement, because the internal ptervgoid and mylohyoid draw the fragments together. (See Fig. 81.) When the line of fracture is from without inward and forward, the internal ptervgoid of the injured side and the mylohyoid draw the posterior fragment inward, while the internal pterygoid of the opposite side draws the anterior fragment outward (Fig. 82). From a consideration of the foregoing facts, we see that when there is displacement it is because the fracture runs from above downward and backward, and from without inward and fon\-ard. The anterior fragment is displaced downward and the posterior fragment is displaced inward. Fractures through the region of the molar teeth are not particularly uncommon, and this is likewise the case with fractures obliquely downward and outward through the angle of the jaw. In these injuries the firm attachment of the masseter on the external surface of the jaw and the internal pterygoid on its inner pre\-ent displacement. Fractures of the coronoid process are exceedingly rare. In them displacement is prevented by the attachment of the temporal muscle, which passes much farther down on the inside than on the outside. Fractures of the neck of the jaw are particularly serious. Inserted into the condyle and neck of the jaw is the external pterygoid muscle. When a fracture of the neck occurs, this muscle pulls the upper fragment anteriorly and tends to tilt its displacement when the line of fractuie runs from the outside forward and inward. with the use of the jaws as to justify an operation to remove or replace the upper frai^ment in proper position. The injury is liable to be overlooked in children, and as "they grow up the deformity shown in Fig. 83 de\'elops. Treatmeyit. — The lower jaw is held up in place by a bandage, and the upper teeth act as a splint. Sometimes the teeth or fragments are wired in position, or an interdental splint of gutta percha or other material is used. Excision of the Condyle of the Jaw. — The condyle can be removed through an incision 3 cm. long, running from in front of the ear along the lower border of the zygorha. The temporal artery runs a centimetre in front of the ear with the auriculotemporal nerve posterior to it. By care in recognizing the artery, it may be saved and dragged posteriorly. The soft parts on the lower side of the wound with the parotid gland and facial nerve are pushed downward. The condyle can then be dug out, care being taken not to go beyond the bone and wound the internal maxillarv artery. Excision of the Mandible. — In removing one-half of the mandible, the incision is made from the symphysis along the lower border of the jaw to the angle and thence upward as high as the lobe of the ear. If it is desired to take extra precautions, the last centimetre of this incision, from the lobule of the ear down, may be carried through the skin only. This will prevent wounding to any great extent the parotid gland tissue, the parotid duct, and positively avoid injuring the facial nerve. The incision, however, is rather far back to wound any large branch of the duct, and is too low down to wound the facial nerve. If it is desired to carry the incision higher than the lobule of the ear, it should go through the skin onlv. The facial artery and vein will be cut just In front of the masseter muscle. The soft parts. including the masseter muscle, are raised from the outer surface. In dividing the bone anteriorly, it should be done .5 cm. outside the median line. This will be about through the socket of the second incisor. The object of this is to retain the attachments of the geniohyoid and geniohyoglossus muscles to the genial tubercles, and so prevent any tendency of the tongue to fall back. The jaw is pulled out and separated from the parts beneath, the mylohyoid muscle being made tense. Care should be taken not to injure the submaxillary gland, which lies below the mylohyoid muscle, and the sublingual gland, which lies above it. The lingual nerve is also liable to be wounded if the knife or ele\-ator is not kept close to the bone. As the detachment proceeds posteriorly, in loosening the internal pterygoid and the superior constrictor, if care is not taken, the pharvnx may be wounded. The bone still being depressed and turned outward, the temporal muscle is to be loosened from the coronoid process or else the process is detached and removed later. Access is now to be had to the mandibular foramen at the mandibular spine or spine of Spix. The inferior alveolar artery is then secured and, with the nerve and sphenomandibular ligament, di\-ided. The jaw can now be well depressed and brought inward. The temporomaxillary joint is to be opened from the front, having first cleared off the attachment of the external pterygoid muscle. There is great danger of wounding the internal maxillary artery at this stage of the operation. It lies close to the neck that the jaw be not twisted outward when disarticulation is being performed. The distance between the coronoid process and malar bone \aries in different individuals. The process may be displaced by the tumor and thus prevent detachment of the temporal muscle. If so, the process is di\"ided with forceps or saw and removed after the rest of the jaw has been taken away. Injury of the temporomaxillary veins may be avoided bv not going behind the posterior edge of the ramus, as is also the case with the external carotid arterv. Access to the joint may be facilitated by dragging upward the parotid gland, which carries with it the facial nerve and parotid duct. The eyeball rests in its socket, which is hollowed out of the soft parts contained in the bony orbit. It is covered in front by the lids, which, as they slide over the eye, are lubricated by the tears. These are secreted by the lachrymal gland at the upper outer portion of the orbit, flow over the eye, and are drained oft by the lachrymal canals and sac to empty into the nose through the lachrymonasal duct. The Orbits. — The orbits are large four-sided cavities, pyramidal in shape. The orbit in an adult male is about 4 cm. in diameter from side to side, and 3.5 cm. from above downward. The depth is 4.5 cm. It is thus seen that the orbit is wider than it is high. On receding into the orbit from its bony edge, the roof arches upward toward the brain to receive the lachrymal gland, thus making the up-anddown diameter slightly longer than the transverse. The rim of the orbit is very strong and not readily broken by injuries. It is formed by the frontal bone above, the malar bone to the outside, the malar and superior maxillary below, and the superior maxillarv and frontal to the inside. The inner (medial) walls of the two orbits are parallel, running distinctly anteroposteriorly. The outer (lateral ) walls diverge at an angle of about 45° from the inner ones. The outer or lateral edge of the orbit is nearlv or quite a centimetre and a half posterior to the inner or medial edge. This fact, together with the divergence of the outer wall, is the reason that, in enucleation of the eye, it is always tilted toward the nose, and the scissors introduced and the nerve cut from the outer side. walls, on the contrary, are thin and weak. The thin orbital plate of the frontal bone above is frequently fractured in puncture wounds by foreign bodies, and the frontal lobe of the brain injured. Two such instances have come under the writer's care; Tiie bonv orbit. in the first case, an iron hook had penetrated and caused death from cerebritis ; in the second, the wound was caused by a carriage pole. The patient recovered, notwithstanding a considerable loss of brain tissue. To the medial side of the inner wall are the ethmoid cells, covered by the thin lachrvmal bone and the os planum of the ethmoid. They are readily perforated by suppuration from within those cavities. The floor is chiefly formed by the thin beneath. At the edge of the junction of the outer and lower walls lies the inferior orbital {^sphenomaxillary ) Jissure. It runs forward to within 1.5 cm. of the edge of the orbit and extends back to the apex of the orbit, where it unites with the superior orbital (sphenoidal ) Jiss7ire, which lies between the roof and outer wall and extends forward about one-third of the distance to the edge of the orbit. The optic foramen enters the apex of the orbit at its upper and inner portion. At the lower inner edge of the orbit is the lachrymal groove for the lachrymonasal duct, leading from the eye to the inferior meatus of the nose. At the junction of the middle and inner thirds of the upper edge is the supra-orbital notch. This can be felt through the skin. It transmits the supra-orbital artery and iierve. If a complete foramen is present instead of a notch, its location cannot be so readily determined. ous with the periosteum. Periosteum. — The periosteum of the orbit is not tightly attached and in cases of disease can readily be raised from the bone beneath. Anteriorly, it is continuous at the orbital rim with the periosteum of the bones of the face. Posteriorly, it is continuous through the optic foramen and sphenoidal fissure with the dura mater. It sends prolongations inward, covering all the separate structures in the orbit. From the edge of the orbit it stretches o\-er to the tarsal cartilages, forming the superior and inferior orbitotarsal ligaments. These form a barrier (called the septum orbitale) to the exit of pus from within the orbit, and for that reason it is ad\-ised that orbital abscesses should be opened early. The lower portion, as it reaches the lachrymal groove, splits to cover the lachrymal sac. Another extension from above splits to enclose the lachrymal gland, which is seen to lie comparatively loose in the upper outer portion of the orbit, su.stained by its suspensory ligament. It then sends thin fibrous layers which cover the muscles, arteries, veins, nerves, fat pellicles, and finally the eyeball posterior to the insertion of the muscles and optic nerve. This last portion, called the capsule of Tenon, begins as far forward as the insertion of the recti muscles on their under (inner) side, passes over the globe posteriorly, over the optic nerve, and blends with the layer covering the deep surface of the muscles. It is joined to the sclerotic coat of the eye and dural sheath of the nerve by a loose net-work of delicate fibrils. This forms practically a space lined with endothelial plates, similar to the subarachnoid space in the brain. The capsule of Tenon is a distinct, well marked membrane, and the eyeball lies loose and revolves freely within it. It is this space into which the strabismus hook is put when it is desired to cut the recti muscles for squint. Fibrous prolongations are also sent to the sides of the orbit from the internal and external recti muscles. They are the check ligaments; and one from the inferior rectus forms the suspensory ligament of the eye. Tumors may either originate in the orbital contents, as sarcomas of the lachrymal gland or eye, or they may come from surrounding regions. It is more rare for them to enter through the natural openings of the orbit than it is for them to push through its thin walls. Coming through natural openings, they may make their entrance : (i) from the brain through the optic foramen or sphenoidal fissure ; (2) from the region of the zygomatic and temporal fossae through the sphenomaxillary fissure; (3) from the nasal cavities (as I have seen), coming up the lachrymonasal canal. In invading the orbit through its walls they may come: (i) from the nasal cavities and ethmoidal cells, pushing through the thin internal wall; (2) from the frontal sinus, appearing at the upper inner angle; (3) from the sphenoidal cells at the posterior portion of the inner wall ; (4) from the brain cavity above, breaking through the roof ; (5) from the maxillary sinus below, pushing through the floor. Dermoids. — In the foetus, the frontonasal process comes from above downward to join the maxillary processes on each side. This leaves an orbitonasal cleft to form the orbit. Owing to defects in the development of this cleft, dermoid tumors may occur in its course. They are seen either at the outer or inner angle of the eye. They are more common at the outer angle near the external angular process, and may have a prolongation to the dura mater. They also occur at the inner angle at the frontonasal suture (Fig. 89). At this point, also, meningoceles are liable to occur. As pointed out by J. Bland Sutton the question of diagnosis is of importance, as an attempt to remove a meningocele by operation is apt to be followed by death, whereas a dermoid, though it may have a fibrous prolongation to the dura mater, can be more safely removed. Orbital Abscess. — Suppuration may either originate within the orbit or extend into it from the neighboring tissues. If the former is the case, it may occur from caries of the bones of the orbit, as in syphilis. It may originate from erysipelas involving the orbit. General inflammation and suppuration of the eye may break through the eye and spread in the orbital tissues (panophthalmitis). If pus enters the orbit from the outside, it is usually from suppuration and caries of the frontal sinus and ethmoidal cells. In this case, the swelling shows itself at the upper portion of the inner angle of the eye. Pus in the maxillary sinus is most apt to discharge into the nose, and not break through the roof into the orbit above. Pus within the orbit tends to push the eyeball forward and even distend the lids. As the orbitotarsal ligament runs from the bony edge of the orbit to the lids, pus does not find an easy exit. The abscess should be opened by elevating the upper lid, and incising the conjunctiva in the sulcus between the globe of the eye and the lid. Pus from suppuration of the lachrymal sac does not tend to invade the orbit but works its way forward to the skin. Foreign Bodies in the Orbit. — Owing to the considerable space which exists between the eye and orbital walls, large foreign bodies may find a lodgment there, often producing serious symptoms for a considerable length of time. The tang of the orbit, distending the lids and producing a peculiar crackling sensation when palpated. No treatment directed to removal of the air is necessary. It is valuable as a diagnostic sign of fracture communicating with the nasal cavities. Hemorrhage. — Hemorrhage into the orbit may occur either as the result of direct traumatism involving the contents, or from fracture of the base of the skull through the orbital plate. The blood pushes its way anteriorly and shows itself under the conjunctiva surrounding the cornea. It is prevented from appearing on the lids by the orbitotarsal ligament. A subconjunctival hemorrhage alone is not sufihcient to justify a diagnosis of fracture of the base of the skull, although it is a significant confirmatory symptom. Kronlein's Operation. — In order to gain access to the back part of the orbit to remove tumors, Kronlein resects the outer wall, divides the periosteum and external rectus muscle, and so gains access to the retrobulbar space. The various steps of the operation are shown in Figs. 90, 91, 92. Sclerotic Coat. — The sclerotic coat forms a firm protective covering or case for the delicate retina within. It is continuous posteriorly with the fibrous coat or dura of the optic nerve, which is a continuation of the dura mater of the brain. At the optic foramen, the dura mater splits into two layers; the outer layer forms the periosteum, while the inner forms the dural coat of the optic nerve. This nerve also, like the brain, has an arachnoid and a pial membrane. The sclerotic coat is continued forward over the front of the eye as the cornea. As it is essentially a membrane intended to be protective in its function, its diseases are those of weakness: thus, if the cornea is affected, it bulges forward and is called an a7iterior staphyloma ; if the posterior part is affected, the sclera is stretched, and it forms a posterior staphyloma. Anterior staphyloma may occur either rapidly as a small local protrusion, resulting from ulceration of the cornea or a wound, or it may be slow in forming, and involve nearly or quite the whole of the cornea, pushing it forward in the shape of a cone; this is called conical cornea. Posterior staphyloma occurs in near-sighted people, the anteroposterior diameter of the eye being longer than normal. If this posterior staphyloma or stretching of the eye becomes marked, the choroid atrophies and the functions of the retina are lost. The white sclera is seen with the ophthalmoscope, surrounding or to one side of the optic nerve. Although the cornea has no blood-vessels, it still, from its exposed position, becomes inflamed {keratitis') and ulcerated, and eventually blood-vessels may develop into it from its periphery, constituting the disease known as pannus. The weakest portion of the globe is at the junction of the sclerotic coat with the cornea. It is here that the sclera is thinnest. On this account, blows on the eye cause it to rupture usually at this point, the tear encircling the edge of the cornea for a variable distance (usually at its upper and inner quadrant) according to the force and direction of the injury. On healing, a staphyloma may form at this point. The choroid or vascular coat of the eye contains the pigment or color of the eye. It is continued forward as the ciliary body (or processes) and iris. Being a vascular tissue, its diseases are inflammatory. If the choroid is affected we have chorioiditis; if the ciliary region is inflamed, it is called cyclitis ; and if the iris is inflamed vi-e have iritis. The retina or nervous coat of the eye is concerned in the function of sight and it, like other nerves, may be affected with inflammation, called retinitis. Sometimes it becomes loosened from the choroid beneath by a hemorrhage or rapid stretching of the sclera, constituting a detachment of the 7^etina. Outside the disk is the macula lutea and fovea centralis or region of distinct vision. Filling the interior of the eye is the jelly-like transparent vitreous humor, enclosed in the hyaloid meinbrane. In front of the vitreous humor is the lens ; and the clear, limpid liquid between the anterior surface of the lens and the posterior surface of the cornea is the aqueous humor. The lens, immediately behind the iris, is suspended in its capsule from the ciliary processes by its suspensory ligament or zone of Zinn. Between the ciliary processes and the sclera lies the ciliary muscle., which regulates the accommodation or focussing power of the eye. The cihary processes are formed of convoluted blood-vessels supported by connective tissue and covered by the pigmented extension of the retina. This ciliary region is an exceedingly sensitive one and a serious wound of it usually means a loss of the eye. Cataract. — When the lens is opaque it constitutes the disease known as cataract: this name is also applied to opacities of the capsule of the lens. When the lens alone is opaque it is called a lenticular cataract; when the capsule alone is affected, it is a capsular cataract. Both are sometimes involved, constituting a lenticiilocapsiilar cataract. The lens is made up of layers like an onion. Some of these layers may become opaque, leaving a surrounding rim of clear tissue. The nucleus within the affected layer is also clear. This form is called a zomclar or lamellar cataract. A capsular cataract may affect the anterior portion of the capsule, forming an anterior polar cataract., or the posterior layer of the capsule, forming a posterior polar cataract. of perforation. As the acjueous humor rcaccumulates, it pushes the lens back, leaving a small portion of inflammatory tissue clinging to its anterior capsule, thus forming an anterior polar cataract. A posterior polar cataract is the result either of disease, such as choroiditis, in which the posterior capsule becomes involved, or of a persistence of the remains of the hyaloid artery, a fetal structure. Secoyidary cataracts are the opacities of the capsule or inflammatory bands and tissues which are left, or which occur, after the removal of the lens. The lens in childhood is soft; it grows harder as age increases. If the aqueous humor obtains access to the lens through a wound of the anterior capsule, the lens becomes opaque, constituting a tranniatic cataract. In operating for cataract in childhood, the lens, being soft, is first rendered opaque by the aqueous humor admitted through a puncture made in the capsule ; if it is admitted repeatedly to the lens by the surgeon's needle (needling or discission operation) the lens matter is completely dissolved. The fluid lens matter can also be removed by a suction instrument. In old people the nucleus becomes hard and opaque, forming a sejiile cataract. The aqueous humor does not dissolve the opaque lens after the acre of thirty five years. Senile cataract rarely occurs before the forty-tifth year, so there is a period of ten years in which a cataract may be a nuclear cataract without being senile. To remo\'e a nuclear or a senile cataract, a slit is made through the cornea near its scleral junction, a piece of the iris may (or may not) be removed, the anterior capsule is cut with a cystotome and the opaque lens pressed out through the opening so made, then through the pupil (either artificial or dilated with atropine) , and finally through the sclerocorneal incision. The posterior capsule is not injured, and it prevents the vitreous humor from escaping. If inflammation follows the operation, the iris and ciliary region throw out lymph and the remains of the capsule become opaque, forming a secondary or capsular cataract. This is removed by tearing or cutting it across with needles or extremely fine scissors. Iris. — The iris is the continuation of the choroid through the ciliary body, and extends down to the pupil, its free edge resting on the anterior surface of the lens. The iris is composed of a vascular and fibrous anterior portion, and a muscular and pigmented posterior portion. In consequence of its vascularity, the iris is the frequent site of inflammation. When inflamed it pours out lymph which may cause it to adhere to the lens behind, forming a posterior synechia. An anterior synechia is where, on account of a perforation of the cornea, the iris washes forward and becomes attached to the cornea in front. The circular muscle fibres surrounding the pupil are anterior, and form the sphincter pupillcE viuscle ; it contracts the pupil. The radiating muscular fibres, which lie posteriorly, form the dilator piipillcE ; it dilates the pupil. The dark pigment layer is on the posterior surface of the iris, and after an attack of iritis, as the adherent iris is torn loose from the lens, it leaves patches of pigment adhering to the anterior capsule. The iris, as it rests at its pupillary margin on the lens, divides the space anterior to the lens into two parts. The part between the posterior surface of the iris and the anterior surface of the lens forms the posterior chamber. The anter'ior chamber lies between the anterior surface of the iris and the posterior surface {^DescemeV s 7nembrane) of the cornea. The two chambers communicate through the pupil. The anterior surface of the iris toward its periphery is of the nature of a coarse meshwork, the spaces of which are the spaces of Foiitana. They communicate with a venous or lymph canal which passes around the eye at the sclerocorneal junction ( canal of Schlem in ) . Aqueous Humor and Anterior Lymph Circulation. — The aqueous humor is of the nature of lymph. It is secreted by the ciliary processes and posterior surface of the iris. It passes through the pupil to the anterior chamber, and enters the spaces of Fontana to empty into the canal of Schlemm. The canal of Schlemm empties its contents into the anterior ciliary veins. In iritis and glaucoma the lymphcurrent is seriously interfered with. In iritis, the swelling and outpouring of Ivmph blocks the spaces of Fontana and prevents a free exit of the aqueous humor from the anterior chamber, therefore in this condition the anterior chamber is deep, and the iris is seen to lie far beneath the cornea. Glaucoma. — Glaucoma is a disease accompanied by increased intra-ocular tension. The eyeball feels hard to the touch. It is supposed to be due to disease of the ciliary region interfering with the canal of Schlemm and obstructing it. Therefore, the drainage of the eye and the circulation of the aqueous humor is interfered with. In iritis the anterior chamber becomes deeper, but in glaucoma, as the intra-ocular tension increases, it pushes the lens forward, and it is seen to lie close up to the cornea; so that a shallow anterior chamber causes the ophthalmologist to suspect glaucoma and a deep anterior chamber iritis. The increased pressure within the eye pushes the optic nerve backward at its point of entrance, so that it is seen sunk below the surface of the adjoining retina, forming a distinct cup-shaped cavity or pit. This is cupping of the disk. Optic Nerve. — The optic nerve reaches from the optic chiasm to the eyeball, a distance of about 5 cm. (2 in.). It enters the apex of the orbit through the optic foramen at the upper inner angle, in company with the ophthalmic artery. The artery crosses the under surface of the ner\'e from its inner to its outer side. The optic nerve has as its coverino- a prolongation of the membranes of the brain. The dura mater when it reaches the foramen spHts and gives one layer to form the periosteum lining the orbit and the other to form a fibrous sheath of the nerve. This arrangement prevents pus, forming in the orbit, from passing through the optic _ foramen into the skull. The arteria centralis rethics enters the nerve on its under side and passes through its centre to the interior of the eye. The nerve itself is covered with a fine pial membrane and an arachnoid separating it from the dura, thus forming subdural and subarachnoid spaces. As these membranes and spaces are continuous with those of the brain, hemorrhage or serous effusions occurring within the brain can thus find their way into the sheath of the nerve. It is readily seen with the ophthalmoscope as a round spot somewhat lighter in color than the surrounding eyeground. Coming from a depression or cup in the disk, called the porus opticus, are the retinal arteries and veins. A certain amount of cupping is normal, but if wide and deep, with overhanging edges over which the vessels can be seen to dip, it is indicative of glaucoma. Sometimes the papilla or disk is swollen, constituting an optic neuritis. In brain tumor this is frequently the case and is called choked disk, or ' 'sta^amg papilla'' -SO named because the circulation was thought to be interfered with owing to the intracerebral pressure being transmitted directly to the nerve. On the subsidence of a severe neuritis the nerve is left in a state of optic atrophy and blindness is the result. Muscles of the Orbit. — Six muscles are connected with the eyeball, four straight and two obUque. One muscle, the levator palpebrce, goes to the lid. The four recti muscles, superior, iyiferior, external, and internal, arise from a common tendinous origin, forming a ring or tube called the ligament of Zinn. This ligament or tube surrounds the optic foramen and is attached to the opposite side of the sphenoidal fissure. Through it run the optic ner^-e and ophthalmic artery, the third, fourth, and the nasal branch of the ophthalmic (fifthj ner\-e. The levator palpebrce and superior oblique arise to the inner side and above the optic foramen close to the origin of the other muscles. The superior oblique, after passing through its trochlea or pulley at the inner upper angle of the orbit, continues downward, backward, and outward between the superior rectus and the eye, to be inserted abo\"e the extremity of the inferior oblique. The ijiferior oblique arises from the anterior edge of the orbit just to the outer side of the lachrymal groove. It passes outward, upward, and backward, over the external surface of the inferior rectus, to be inserted beneath the external rectus. The recti muscles insert into the sclera 5 to 7 mm. back from the cornea. In the operation for internal squint or strabismus, the internal rectus muscle is cut. It possesses the longest tendon of insertion, while the external possesses the shortesL The recti muscles pull the eyes toward their respective sides. The superior oblique turns the cornea down and out and rotates it inwardlv. The inferior oblique turns the cornea up and slightly out and rotates the eve outward. A disarrangement of any of these muscles produces diplopia or double vision. Blood-Vessels of the Orbit. — The arteries of the orbit are derived from the ophthalmic artery, which breaks up into its various branches soon after it passes through the optic foramen. In enucleation of the eye there is practically no bleeding, because the arteria ceyitralis is the only one divided, and it is small. In evisceration, or cleaning out of the contents of the orbit, the main trunk of the ophthalmic will not be cut unless the very apex is invaded. Hemorrhage is readily controlled by packing gauze into the orbital cavity. The veins of the orbit are the superior and inferior ophthalmic. The former is much the larger and more important. It not onlv drains the upper portion of the orbit, but communicates directlv with the angular branch of the facial, at the inner canthus of the eye. The infection of ervsipelas sometimes travels along these veins directly from the nose, face, and scalp without, to the cavernous sinus and meninges within, causing thrombosis and death. The inferior ophthahiiic usually empties into the superior; its anastomoses at the anterior portion of the orbit w'nh the \eins of the face are much smaller and, therefore, not nearly so dangerous. Nerves of the Orbit. — The opfic ?ien'e is the nerve of sight. Interference with it produces blindness. The oculomotor or third nej've supplies all the muscles of the orbit except the external rectus and superior oblique. If paralyzed, the eye cannot be moved upward, inward, or to any extent downward. There will be ptosis of the upper lid from paralysis of the levator palpebrae, and dilatation of the pupil and paralysis of the accommodation of the eye. If the sixth or abducens is paralyzed, the eye cannot be turned outward. If \.\\q fourth or pathetic is paralyzed, the superior oblique fails to act, and the double vision produced is worse when the patient looks down, because it is normally a depressor muscle. The lachrymal, frontal, and 7iasal branches of the fifth are ner\-es of sensation, hence, in supra-orbital neuralgia and that affecting the nasal branch, pain is felt in the orbit at the inner angle of the eye and down the side of the nose. Retina. — On the interior of the eye, the expansion of the optic ner\e forms the retina. The retina is divided into two lateral halves, each supplied by a corresponding half of the optic nerve. When the nerve reaches the optic chiasm it splits into two parts, one (internal fibres) going to the opposite side of the brain, and the other (external fibres) to the ganglia on the same side of the brain. Posterior to the chiasm, the nerve fibres form the optic tracts. The optic tracts, after leaving the chiasm, wind around the crura cerebri to the external geniculate bodies, thence they pass to the thalami and anterior corpora quadrigemina, and are continued backward into the cuneus lobule of the occipital lobe of the brain. It will thus be seen that a lesion affecting any portion of the optic pathway posterior to the chiasm will produce blindness of one-half of the retina of both eyes on the side of the injurv; a right-sided lesion will produce blindness of the right half of both retinae, and a lesion on the left side, blindness of the left half of both eyes. This is called hemianopia. It is right lateral hemianopia if the right half of the \isual fields is affected, and left lateral if the left sides are affected. Afi'ections of the optic nerve produce total blindness of that eye if the whole nerve is involved. If only a part is in\-oh"ed, then a unilateral heniiayiopia may ensue. A bitemporal hemianopia may be caused by a tumor involving the anterior or middle portion of the chiasm. A binasal hemia7iopia requires a symmetrical lesion on the outer side of both optic nerves or tracts. A brain tumor located in the cuneus lobule would cause a lateral hemianopia of the same side, right or left, of both visual fields, hence sometimes called homonymous. The Eyelids and Conjunctiva. — The eyelids are composed of five layers, viz: (i) skin, (2) subcutaneous tissue, (3) orbicularis palpebrarum muscle, (4) tarsal caHilage with the contained Meibomian glands, (5) the conjunctiva. The juncture of the two lids at each end is called the inner and outer canthus. The skin of the lids is thin and the subcutaneous tissue loose and devoid of fat. For these reasons blood finds its way readily into the lids and shows plainly beneath the skin, constituting the familiar "black eye. " The skin lends itself readily to plastic operations, as it is easily raised and the gap left can be readily closed. The blood supply of the lids is abundant, so that the flaps are well nourished and sloughing is not apt to occur. The folds in the skin run parallel to the edge of the lids, therefore the incisions should be made as much as possible in the same direction. The orbicularis palpebrarum muscle passes circularly o\'er the lids and lies on the tarsal cartilage toward the edge of the lids and on the orbitotarsal ligament above. The socalled tarsal cartilage ox plate is composed of dense connective tissue and contains no cartilage cells. It is attached externally by the external (^lateral) palpebral liga77ient and internally by the i7iter7ial {77iedial) palpeb7'al Iiga7ne7it or tendo-oculi. This latter passes in front of the lachrymal sac. The tarsal plate is continued to the rim of the orbit bv the o7'bitotarsal Iiga7;?e7it or septu77i orbitale. The expansion of the levator palpebrce muscle ends in the upper edge of the tarsal cartilage and sends some fibres to the tissues immediately in front. The orbitotarsal ligament and tarsal cartilage prevent the fat of the orbit from protruding and also act as a barrier to the exit of pus. Frequently these glands become obstructed and their mucus contents dilate the gland, forming a cyst known as chalazion. Suppuration may occur and pus instead of mucus is then contained within them. The wall of these cysts is formed by fiDrous tissue containing some of the epithelial cells of the glands; therefore, if an uninflamed cyst is simply opened and its contents expressed, it will soon reform. To prevent this recurrence, the hning membrane is curetted in order to remove the mucus-forming cells. The cyst may point and be opened either on the side of the skin or conjunctiva, preferably the latter. The openings of the Meibomian ducts are on the inner edge of the lids where the conjunctiva joins the skin. At the outer edge of the lids are the cilice or eyelashes and connected with them are sebaceous and sweat glands. Infection of these lids they tend to discharge anteriorly and not toward the conjunctiva. The conJ2inctiva covers the outer surface of the eye and the inner surface of the lids. The fold where it passes from one to the other is called the for7iix. The tarsal or palpebral conjunctiva adheres closely to the tarsus and as it is transparent the Meibomian glands can readily be seen through it. The ocnlar or bulbar co7ijunctiva is loosely adherent to the sclerotic coat and through it the conjunctival vessels, which move with it, can be seen. The straight vessels going toward the cornea do not move when the coniunctiva is moved, because they lie deeper and are attached to the sclera. portion is enclosed in a capsule and slung from the orbital margin by its suspensoryligament. Beneath, it rests on the fascial expansion of the levator palpebree muscle. The palpebral portion is smaller than the orbital and is partially separated from it by the fascial expansion. It lies on the conjuncti\a at the upper and outer portion of its fornix. The lachrymal gland opens by several fine ducts into the fornix of the conjunctiva. It is sometimes the seat of malignant tumors, but rarely of other troubles. The remaining lachrymal passages running from the eye to the nose are frequently the seat of inflammation, causing suppuration and obstruction. TYi^punda lachrymalia in the top of each papilla lead into the canaliadi. These enter the lids perpendicular to their margin and turning at right angles join just before entering the upper end of the lachrymal sac. The lachryihal canal, embracing the sac and lachrymonasal duct, each about 12 mm. in length, extends from just above the internal tarsal ligament or tendo oculi to the inferior meatus of the nose. The sac is strengthened posteriorly by the toisor tar-si or muscle of Horner, which passes from the lachrymal bone to the puncta, and by some fibres of the palpebral ligament. Anteriorly is the strong palpebral ligament. Below the palpebral ligament, the sac is comparatively weak and here it is that distention occurs and pus makes its exit. The duct lies in the lachrymal groove in the bone. It is narrower than the sac, being 3 to 4 mm. in width, and is the usual seat of obstructions. To keep the passage open in case of stricture probes are passed. The direction of the duct is slightly outward and more markedly backward, being indicated approximately by a line drawn from the inner canthus to just behind the second premolar tooth. In probing the duct it is customary to first open the punctum in the lower lid — which is normally only one mm. in size — by slitting it and the caniculus with a Weber's canaliculus knife. The probe is directed horizontally until the sac is entered, which is recognized by the end of the probe striking the bone; it is then raised vertically and passed downward and backward and sometimes slightly outward until it can be seen in the inferior meatus of the nose about i cm. behind the anterior end of the inferior turbinated bone. The external aiiditory meatus, the tympanutn, and the Eustachian tube are the remains of the first branchial cleft in the foetus. A failure of any portion of the cleft to close normally may leave small sinuses or depressions in the neighborhood of the ear. The external ear, also called the auricle or pinna, is composed mainly of a cartilaginous framework covered with thin skin; the lobe or lobule forms its lower part and is composed of dense connective tissue containing fat. The large concavity leading into the meatus is the concha. The skin of the ear is thin and moder- ately firmly attached to the cartilage. The subcutaneous tissue contains little or no fat. Although well supplied with blood, the exposed condition of the blood-vessels renders the ear sensitive to cold, and frost-bites are common. Injuries and wounds of the cartilage are slow to heal, and if inflamed the cartilage becomes exceedingly sensitive. Swelling of the ear readily occurs from injury or erysipelas, and the tension is quite painful. Hceniatoma auris, or effusions of blood, occur from traumatism, especially in the insane. While a hsematoma may occur between the skin and perichondrium, on account of the firm binding of the skin to the cartilage it is usually between the perichondrium and cartilage. extension, may demand operation. The external ear derives its blood supply from the auricular branches of the temporal, internal maxillary, posterior auricular, and occipital arteries. As these are all branches of the external carotid, that artery is sometimes tied as a preliminary step to excising the angiomatous vessels. The External Meatus.— The external auditory meatus extends from the concha to the drumhead, and is about 2.5 cm. in length. Viewed anteroposteriorly the canal has a slight curve with its con\exity upward (Fig. loo). \'iewed from above (Fig. loi ), it is seen iirst to pass backward and then forward, forming an angle before the bony wall is reached. In order to look into the ear and see the membrane it is necessary to straighten the canal, either by inserting a speculum or by pulhng the auricle outward, upward^ and backward. In children, upward traction is not so necessary as in the adult. The length of the canal is approximately the same in childhood as in adults, but the bony part is still in a cartilaginous condition. The external opening is oval, while farther in the canal is more circular; hence the Gruber speculum, which is oval in shape, or the round speculum of Wilde can be used \\ith almost equal satisfaction. The point of junction of the bony and cartilaginous parts is narrower than either end, and it is difficult to remove a foreign body which has passed this point. This is particularly true in children, the lumen, of the external meatus being quite small and narrow while the tympanic membrane is nearly as large as in adults. part is completed by a fibrous membrane. Below and in front is the temporomaxillary joint, and just posterior is the glenoid lobe of the parotid gland. When the gland is inflamed and swollen it presses on the cartilaginous canal and produces pain ; and in cases of suppuration pus may discharge through the external meatus, gaining access to the canal through fissures in the cartilage called the fissures of Saiitorini. The cartilaginous portion of the meatus contains sweat-glands, sebaceous glands, and hair-follicles. There are only a few glands in the upper posterior portion of the bony meatus. On account of the location of the glands in the external portion of the canal, accumulations of wax, and abscesses, which result from infection of the glands, occur nearer to the surface than to the drum membrane. It is only when the canal begins to fill up that the wax pushes its way to the membrane. When furuncles occur, the lining membrane swells and by closing the canal pre\'ents a \'iew of the drum being obtained. Incising of furuncles of the auditory meatus is sometimes required. The site of the inflamed spot having been located, an incision' can be made where indicated. If care is exercised, one is not likely to injure the drum membrane, because the abscess starts in one of the sebaceous glands, which are located in the external half of the meatus. The membrane lies 2. 5 cm. from the surface, and the point of the knife should not be carried so deeply as that for fear of wounding it; there is no necessity of going so far inward. THE EAR. 87 The meatus is supplied by the aziriculoteviporal branch of the fifth and the auric2dar branch of the pneumogastric nerve. Irritation of the latter nerve is said to be the cause of feeling it in the throat when anything is put in the ear. Membrana Tympani. — The membrana tympani is inclined downward and inward at an angle of about 140° to the upper wall (Troltsch) and 27° to the lower wall (Bezold) of the meatus ; it does not lie directly trans\-erse, therefore in introducing instruments into the ear the upper posterior part will be first encountered. The membrane is located 2.5 cm. (i in.) from the surface; this is to be borne in mind in puncturing the membrane or other operations. The membrane has three coats: an outer, continuous with the skin of the meatus; a fibrous or middle layer; and an internal or mucous layer, continuous with the lining of the tympanic cavity. The membrana tympani at birth is fastened at its circumference to the tympanic bone, which unites with the other portions of the temporal bone soon after birth. This ring of bone is incomplete at its upper portion for a distance equaling one-eighth of its circumference. This is called the 7iotch of Rivinus. The fibrous layer does not extend across this notch, which is closed by the mucous membrane on the inside and by the skin layer of the membrane on its outer side. The part closing the notch is called ShrapnelV s membj'ane or membrana flaccida. As it possesses no fibrous layer it is weaker than the membrane elsewhere and consequently is a favorite spot for pus to perforate in order to find exit from the middle ear. In examining the membrane by means of light thrown into the meatus through a speculum by the head mirror, one sees extending downward from its centre a small cone of light; any depression or bulging of the membrane will cause this cone of tight to be altered in its position, or even cause it to disappear entirely. From the centre of the membrane upward extends a line which indicates the attachment of the long handle of the malleus, one of the bones of the middle ear. Stretching across the upper portion is the membrane of Shrapnell or membrana flaccida, so called on account of its not being so tense as the remaining portion. It is better supplied with blood-vessels than the other portion. The membrana tympani is of surgical interest on account of its being often distended or perforated. A purulent discharge from the ear usually indicates disease of the middle ear or tympanum. If pus is coming from a furuncle of the meatus, the latter will be swollen and its source can readily be recognized. If it comes from outside of the meatus, as in cases of suppuration of the parotid gland, it Avill be recognized by an examination of the gland. There is no other source of pus but the middle ear and for it to gain exit it must perforate the membrane; this perforation can usually be seen with the speculum and head mirror, as can also bulging. paracentesis or punctui'e is resorted to. The preferable spot is the posterior lower quadrant. Paracentesis of the membrane should be done by beginning the incision a little above and behind the centre of the tympanic membrane, which slopes downward and forward at an angle of 140° to the upper wall, and cutting downward to its lower edge. One must avoid the long handle of the malleus, which extends directly upward from the centre of the membrane. In the upper posterior part are the incus and stapes, therefore this portion should be avoided; and running across the upper edge beneath the mucous membrane is the chorda tympani nerve. Division of this nerve is said to be a matter of not much account. Incision through the anterior part is not considered suitable for drainage. Perforations frequently occur through Shrapnell's membrane on account of its not having any fibrous layer; thus the pus does not go through the tympanic membrane proper. If perforation with a purulent discharge has existed for a long time granulations come through the opening, forming an aural polyp. To remove these a snare is used or caustic is applied. The Tympanum or Middle Ear. — The tympanic cavity is flat and narrow and is situated directly behind and also above the membrane. It has a floor and roof, and external and internal walls. It is divided into the portion behind the membrane and the portion above the membrane called the attic. The floor is narrower than the roof and is formed by the tympanic plate ^ which separates it from the jugular the mastoid antrum, Eustachian tube, etc. fossa containing the commencement of the internal jugular vein. The bone forming the floor is more difficult for pus to perforate than is that of the roof, so that extension of middle-ear disease is less frequent through it. The roof is comparatively thin and formed of cancellous tissue with a thin and weak outside compact layer; therefore it is a somewhat common site for pus to perforate and thereby obtain access to the middle fossa of the skull. The distance from the floor to the roof is approximately 15 mm. (\| in.); half is behind the membrane and the rest forms the attic above. The external wall is formed below by the tympanic membrane and above by the bone. As the membrane is the weakest portion of the walls, collections of pus in the middle car most often find a vent through it. Immediately behind the membrane are the lower portions of the ossicles, and above is the chorda tympani nerve. The internal zvall is formed of bone and is from 2 to 4 mm. (yV to i of an inch) behind the membrane. It is so close that in doing the operation of paracentesis care must be taken not to thrust the knife too deeply. In it are the oval and round windows (Fig. 103). There is no well-defined anterior or posterior wall. The anterior portion of the cavity is continued forward into the Eustachian tube; the canal for the tensor tympani muscle is immediately above it. Posteriorly the cavity of the attic is continuous through the aditics with the mastoid antrum and the cells beyond. Posterior to the opening of the Eustachian tube is an elevation on the internal wall called the promontory, formed by one of the semicircular canals. Above the promontory is the fenesti'a ovalis, which lodges the stapes bone and communicates with the vestibule. Below and behind is the fenestra rotunda, closed by a membrane separating the cochlea from the middle ear. Above the fenestra ovalis is a ridge of bone marking the aqueduct of Fallopius, in which runs the facial nerve. The Eustachian tube passes from the anterior portion of the tympanic cavity downward, forward, and inward to the upper posterior portion of the pharynx about level with the floor of the nose. It is about 3.5 cm. (approximately 1^2 in.) in length. The outer third, near the ear, is bony and the inner two-thirds are cartilaginous. The point of junction of the bony and cartilaginous portions is the narrowest portion of the tube and is called the istJvnus. The tube is usually closed, but opens in swallowing, yawning, etc., thus admitting air to the tympanic cavity and mastoid cells. Catarrhal affections of the throat readily travel up the tube and set up an inflammation of the middle ear. Swelling of the lining of the tube follows and air no longer passes to the ear. To open the tube two methods are employed — that of Valsalva, and that of Politzer. The former consists in holding the nostrils and mouth shut and attempting to blow, when the action of the throat and palate muscles opens the tube and allows the air to enter. In the method of Politzer, the patient is given a sip of water which he swallows on command. The nozzle of a rubber air-bag is placed in one nostril and the other held shut. As the patient swallows, the air-bag is compressed and the air enters the Eustachian tube. Sometimes this method is varied by asking the patient to say ' 'hock, ' ' thus causing the tube to open, when the air-bag is compressed. The calibre of the tube is sometimes so small that probes are passed up it to dilate it. Care is necessary to avoid introducing the probe too far or it will injure the ossicles of the ear. Pus will sometimes discharge through the tube. I have seen pus coming from the middle ear pass down the tube into the inferior meatus and be blown out the anterior nares. tube is the canal for the tensor tynipani muscle. The attic is directly above the tympanic cavity and contains the greater part of the ossicles. Between the two along the inner wall runs a ridge of bone within which is the aquseductus Fallopii, containing the facial nerve. The roof of the attic is called the tegmen. It is a thin shell of bone, varying in thickness, and separates the cavity of the ear from the middle cerebral fossa abo\'e. Pus frequently eats its way through at this point and forms a subdural abscess, which bv working its way backward involves the lateral (transverse) sinus, causing thrombosis and general septic infection. The antrum is a little larger than the attic. The two cavities are continuous through th^ikus. The roof of the antrum is level with the roof of the attic and its flioor IS abo^^^l with the top of the membrane. It is thus seen to be directly above and pos^^^ to it. Mastoiditis. — The mastoid cells are continuous with the antrum and permeate the mastoid process down to its tip. The cells come so close to the surface that suppuration within them often bursts through and discharges behind the ear. The upper, inner, and lower portions of the bone are also sometimes perforated, which will be referred to later. Middle-ear Disease. — Suppuration from middle-ear disease is caused by an infective intiammation tra\'elling up the Eustadiian tube from the pharynx and nasal cavities. It may pass to the attic above j^Athence to the mastoid antrum and mastoid cells. Pus usually finds an exit b^^H\|rating the tympanic membrane and discharging through the external auditor^B^s. As already stated, it may pass down the Eustachian tube to be blown out oWhCTanterior nares. It has been known to pass down the canal for the tensor tympanim\|yscle, and form a retropharyjigeal abscess. As the pus reaches tli^^harynx i(\|^H the prevertebral fascia, it may extend laterally and appear ext JH\|y behiii^PB\|\|\|sternomastoid muscle. Having anteriorly, and thus implicate the jugular vein and internal carotid artery. It may eat into the posterior wall and involve the facial nerve, which is covered by only a thin shell of bone, and produce facial paralysis, attack the internal ear through the fenestra ovalis and rotunda and pass through the internal meatus to the brain. If it extends upward and involves the attic and antrum, it may perforate the roof, or tegmen, and form a subdural abscess in the back part of the middle cerebral fossa, whence it travels a distance of about a centimetre to the lateral sinus, causing a thrombus to form, or it may produce an abscess of the temporosphenoidal lobe pf the brain. The antrum and mastoid cells being continuous, the posterior and inner walls may be perforated, the pus thereby reaching the posterior cerebral fossa, again involving the lateral sinus, or producing a cerebellar abscess. If it perforates the mastoid process on its inner wall at the groove for the digastric muscle, the pus gains access to the back of the neck, forming what is known as Bezold s abscess. Operations on the Middle Ear. — The operations on the middle ear, besides those involving the membrane, are done either for the removal of the remams of the membrane and ossicles, or else to clear out the antrum and mastoid cells and even, if necessary, examine the lateral sinus and jugular vein and explore the brain. They are done for suppurative affections, which may be either chronic, producing local symptoms, or acute, producing in addition constitutional disturbances and even general infection. Caries of the bones is a prominent condition in suppurative cases In removal of the ossicles, the tympanic membrane is first s^^^Vd around its edges. Then the tendon of the tensor tympani muscle is cut, ai:^^^pncus disarticulated from the stapes. The latter is done by cutting with a bSIWcnife across the axis of the stapes and not of the incus (see Fig. 105). The malleus is seized and drawn first down and then out, bringing the membrane with it, and afterwards the incus, which is detached by Ludwig's hook (see Fig. 106), is removed, and, if desired, the stapes. Granulations and pus are removed by the snare, forceps or curette. Care is to be taken to avoid, if possible, scraping away the thin shell of bone on the internal wall that covejs the facial nerve. Any twitching- of the muscles of the face indicates t tympani nerve, which passes on t beneath the mucous membrane, is follow its removal. of the zygoma. The upper and posterior edge of the meatus is formed by a thin, small shell or edge of bone running from the suprameatal crest downward and backward to the posterior wall; this is the supravieatal spine. Behind the suprameatal spine and between it and the posterior portion of the suprameatal crest is a depression, the s'uprameatal fossa. This suprameatal fossa is triangular in shape. The crest forms the upper side, the spine its anterior side, and the ridge of bone, running from the posterior portion of the crest to the lower portion of the spine, forms the posterior side. These three lines form the suprameatal triangle of Macezcen. It is through this triangle that the antrum may be reached. The operation may be restricted to the antrum and tympanic cavity, or may include the whole or part of the mastoid cells, constituting the operation known as tympanomastoid exenteration. To reach the antrum a semicircular cut is made a centimetre back of the ear and the ear and membranous canal loosened and pushed forward. With a gouge chips of bone are removed from the suprameatal spine backward and from the crest downward as far as desired. This will extend considerably beyond the line marking the posterior boundary of Macewen' s triangle. The outer table of bone being removed, the cells are broken through parallel to the meatus and slightly upward, for the lower level of the antrum corresponds to the upper edge of the meatus. It is hardly safe to penetrate deeper than 1.5 cm. (f in.) from the meatal spine inward, for fear of wounding the facial nerve. The mastoid antrum lies not only above and posterior to the membrane and tympanic cavity, but extends outward along the posterior and upper portion of the canal, and the facial nerve can be Fallopian canal below and anteriorly. In doing a tympanomastoid exenteration, a more extensive procedure is performed. It consists in cleaning out the various communicating cavities and throwing them together, thus making their interior more accessible. The antrum is reached in one of two ways: either posteriorly, or anteriorly through the meatus. The posterior operation, or that of Schwartze, Zaufal, and others, consists in removing the membranous lining of the bony meatus on its upper and posterior portions down to the tympanic membrane. The antrum is then entered as already described; the posterior bony wall of the meatus is chiselled away, giving access to the tympanum; the ridge of bone separating the roof of the bony meatus from the attic or epitympanum is chiselled away (see Fig. 109), and the membrane and os- the mastoid process. If the anterior operation of Stacke is performed, the membranous lining of the bony meatus is to be loosened and divided as close to the membrane as possible and drawn forward with the cartilaginous meatus. The drum membrane and as much of the ossicles as possible are then to be removed, and with a chisel or bent gouge the angle, or ridge of bone between the upper side of the bony meatus and epitympanum, or attic, cut away. The antrum is now entered by chiselHng away the upper posterior wall and the chiselling away of bone continued until the mastoid cells have been sufficiently exposed. The final result of these two methods is the same. The external mastoid antrum. meatus, tympanum, epitympanum, antrum, and mastoid cells are all thrown into one large cavity. Wounding of the facial nerve is to be avoided by first learning its course and then by sponging away the blood and cutting only the structures which are clearly visible. Tracing the facial nerve backward, it is seen (Fig. 103) entering the stylomastoid foramen, how to reach and how to avoid the brain and lateral sinus. The lower level of the brain in the region of the ear corresponds to a prolongation directly backward in a straight line of the posterior root of the zygoma. If one keeps below this line, he is not likely to open the brain case. If it is desired to explore the under surface of the brain or dura directly over the middle-ear cavity, then one trephines above this line or suprameatal crest, the lower edge of the trephine opening being .5 cm. above it. This will lead- to the middle fossa of the skull, occupied by the temporosphenoidal lobe. The sharp upper and posterior edge of the petrous portion of the temporal bone gives attachment to the tentorium and separates the middle cerebral fossa in front from the posterior fossa, containing the cerebellum, behind. The point at which this ridge and tentorium reach the side of the skull is indicated by the point of crossing of a line drawn up from the tip of the mastoid process, midway between its anterior and posterior borders, and the line of the posterior root of the zygoma. The course of the lateral sinus is indicated by a curved line from above and to the right (about .5 to I cm.) of the external occipital protuberance to the upper posterior portion of the mastoid process and thence to its tip. The anterior edge of the lateral sinus reaches as far forward as a line drawn from the tip of the mastoid upward, midway between its anterior and posterior borders. The point at which it turns is where this mastoid line intersects the line of the zygoma. Its upper edge rises above this line approximately i cm. The sinus is I cm. in width. The distance of the sinus from the surface varies from .5 cm., or even less, at the top of the mastoid process to 1.5 cm. at its tip. So uncertain is this that the only safe way to expose the sinus is to cut the bone off with a mallet and gouge in thin chips parallel to the surface. The use of a trephine or other boring instrument is not to be advised. If the infection of the lateral sinus has extended to the jugular vein this latter must be reached by means of a separate incision in the neck. Externally the nose forms a prominent projection on the face, hence it is frequently injured and its construction should be studied in relation to those injuries. It forms a conspicuous portion of the features, hence deformities or disfigurements of it are very distressing, so that plastic operations are done for their relief. Internally, the nasal cavities are concerned in the sense of smell and form the passage-way to and from the lungs and the \'arious accessory cavities for the air in respiration. It likewise serves as a receptacle for the tears as they come down the lachrymona^-al duct. Interference with the flow of air by obstruction of the nasal chambers may cause affections of the pharvnx, larynx, lungs, ears, or accessory sinuses — ethmoid, sphenoid, maxillary, and frontal. Catarrhal troubles may start in the nose and in\'ade any of these parts. They may even extend up the Eustachian tube and cause deafness; or up the lachrymonasal duct and cause trouble with the lachrymal canal or conjunctiva. A knowledge of the nose is essential to all those who wish to devote themselves especially to affections of the eye, ear, and throat, because the origin of the affections of these organs may be in the nasal chambers instead of the organ in which they are most manifest. The skin over the root of the nose is thin and lax. It is well svipplied with blood by the frontal and nasal branches of the ophthalmic, and the angular branch of the facial arteries. In reconstructing a nose by means of a flap taken from the forehead, it is these branches that nourish it. The laxity of the skin allows the pedicle to be twisted around without interfering with the circulation. The skin over the tip and alae is thick and adherent to the cartilages. It possesses a comparatively scanty blood supply, hence its liability to suffer from cold, and is a favorite site for ulcerations, as lupus, superficial epithelioma (rodent ulcer), etc. Sebaceous and sweat glands are abundant, and stiff' hairs guard the inside of the nostrils. These latter are not seldom the seat of small furuncles oi- boils, which are extremely painful. This is due to the tension caused by the congestion and swelling, which is restricted by the tissues being so firmly bound to the cartilages beneath. Nerves. — In addition to the olfactory nerve, the nose is supplied by the nasal, infratrochlear, and infra-orbital branches of the fifth ner\'e, hence the eyes water when the nose is injured. In certain cases of neuralgia aft'ecting the ophthalmic division of the fifth nerve, pain is felt along the side of the nose. As the nasal nerve enters the skull from the orbit through the anterior ethmoidal foramen, it may be involved in disease of the ethmoidal sinuses. The nose proper consists of a bony and a cartilaginous portion. The bojiy portion is formed by the two nasal bones articulating with the frontal bone abo\e, with each other in the median line, and with the nasal process of the superior maxilla on the side. They are supported on the inside by the upper anterior portion of perpendicular plate of the ethmoid. The cartilaginous portioii consists of four lateral cartilages, two on each side, upper and lower, and the triangular cartilage, or cartilaginous septum on the inside. The external shape of the nose viewed in profile is composed of three portions: an upper of bone, a middle of cartilage — the upper lateral cartilages — and a lower, or tip, formed by the lower lateral cartilages. The bridge of the nose is formed by bone; it slopes downward and forward and where it joins the upper lateral cartilage the line changes and slopes more downward, until the tip is reached, here the lower lateral cartilages bulge forward, forming a rounded and more or less projecting tip. Injuries to the Nose. — The bones and cartilages may be fracUired or' dislocated. This may invoh-e either the outside structures or those forming the septum, and often both. The displacement depends on the character and direction of the injury. It is either a displacement to one side, or the nose is crushed, producing a flattening of the bridge. If the displacement is lateral, whether by a dislocation or fracture, there is liable to be a de\-iation of the septum, because the bony and cartilaginous septum is connected with the bones and is apt to be carried with them to the side. If the displacement is inward, not only are the nasal bones depressed, but the septum beneath may be either bent or fractured. The pushing of the septum toward the floor causes 'it to buckle and bend or e\en break at the junction of the triangular cartilage with the perpendicular plate of the ethmoid and the vomer. In treating these fractures, the most efiticient method is to grasp the septum with the flat blades of an Adams forceps (after cocainization) and lift the bones up or to one side as needed. In cases where it is not desired to use the forceps, the writer grasps the nose with a wet towel, makes traction to loosen the fragments, and then pushes them over into place. The triangular cartilage is frequently injured; with the displacement or loosening of the upper lateral cartilages a great amount of displacement may be caused, so that the nose instead of forming a straight line is bent to one side from the ends of the bones down to the tip. Injuries to the septum in childhood are probably the cause of a large number of the cases of deviation of the septum, spurs, etc., seen later in life. In fractures the mucous membrane is often torn, thus allowing air to enter the tissues at the site of fracture, producing emphysema. If such a patient blows the nose violently, the air may be forced under the skin of the face, around the eyes and up the forehead. Anterior Nares, — The nostrils or anterior nares in the white race are an elongated oval in shape and run in an anteroposterior direction, being separated from each other bv the coliimna. They lie in a direction parallel with the floor of the nose, SO that to examine the nasal fossce with a speculum the instrument is first introduced from below, then tilting the tip of the nose upward, the speculum is directed backward. To see the floor of the nose, it is necessary to raise the outer end of the speculum still higher, because the floor is below the bony edge. From the outer edge of the nostril the nasal cavities go upward and backward for a distance of .5 to I cm. This part, called the vestibule, is covered by skin, not mucous membrane. It bears stifi hairs — vibrissae. Inflammation of these hair-follicles and associated glands produces exceedingly painful pustules. It is here likewise that dried mucus collects and forms scabs, which stick to the hairs and are hard to remove. The attempt to remove them probably is the cause of infection and inflammation around the roots of the hairs. The vestibule leads to the ridge of bone or crest, which is directly posterior to the side of the nasal spine. This ridge of bone is on a higher level than the floor of the nose, and in order to view the latter the nostrils must be raised, by means of the speculum, above it (Fig. 115). View frotn the Anterior Nares. — In looking into the nose from in front, if the speculum is directed downward, the floor of the nose and the inferior meatus can be seen. On the inner side is the septum, on the outer the anterior end of the inferior turbinated bone. Still higher is the middle meatus and the anterior end of the middle turbinated bone. The superior turbinated bone is not visible from the front, being in the upper posterior corner and hidden from sight by the middle turbinated. Sometimes in the upper portion of the nose, beneath the outer surface of the anterior extremity of the middle turbinated bone, is seen a small cleft, the hiatus semilunaris, leading through the infundibulum into the frontal sinus. If the inferior turbinated has been shrunk with cocaine, and if the inferior meatus is roomy, one can see the posterior wall of the pharynx. This can be seen moving if the patient swallows, pronounces the letter "k," etc., (Fig. ii6). separated from each other by the septum. This septum is formed (see Fig. 117) by the triangular cartilage in front, forming the cartilaginous septum, and the perpendicular plate of the ethmoid and vomer behind, forming the bony septum. The posterior edge of the septum is formed solely by the edge of the vomer ; it can readily be seen with the rhinoscopic mirror. The affections of the septum are haematoma, ulcer and abscess, deviation to one side, spurs or outgrowths, and it may be the site of nasal hemorrhages. Htxmatomas affect the cartilage of the septum and resemble those of the ear. They are usually due to traumatism and may become infected, forming a pus-like detritus or abscess. They can readily be recognized as a fluctuating swelling on the septum, one or both sides being affected. Deviations of the septum are bendings toward one side, and cause serious obstruction to breathing. They are probably traumatic in origin and involve the castilaginous portion. In operating for their correction, incisions are niade through the cartilage and the projecting part pushed toward the median line. In some operations care is taken not to cut through the mucous membrane on both sides, as well as through the cartilage. This is done to avoid the formation of a permanent perforation of the septum, the presence of which may cause a very objectionable whistling sound when the patient breathes. As the mucous membrane covering the cartilage is thin, great care is necessarv in di\'iding the cartilage to avoid wounding the side which it is desired to leave intact. The triangular cartilage is thin at its centre and thick at its edges. Spurs are usuallv outgrowths of bone or cartilage occurring in the line of juncture of the cartilage and vomer. On the floor of the nose the nasal crest may project quite perceptibly to one side; a cartilaginous projection may likewise occupy this site. As these spurs are found on the anterior edge of the \omer, they some- times form a distinct ridge of bone running upward and backward. If the spur is short in extent, the farther posterior it is situated, the higher up it is on the septum. If marked, it is often accompanied by deviation of the septum and it may impinge on the lower turbinated bone opposite to it. These spurs are usuaUy removed by sawing. A narrow-bladed saw is introduced with its back on the floor of the nose and the spur removed by sawing upward (Fig. ii8). Epistaxis or bleeding from the nose is said to occur in a large percentage of the cases from the septal branch of the sphenopalatine artery. This comes from the internal maxillary artery through the sphenopalatine foramen and passes downward and forward as the nasopalatine or artery of the septum. It anastomoses below with the anterior palatine branch of the descending palatine artery as it comes up from the roof of the mouth through the foramen of Stenson (incisor foramen). It also anastomoses with the inferior artery of the septum, a branch of the superior coronary. The bleeding point is to be sought for low down on the anterior portion of the cartilaginous septum near the anterior nares. Hemorrhage can be stopped by packing only the anterior or both the anterior and posterior nares. The arteries supplying the nasal cavities (Fig. 1 19; come from three directions : superior — the anterior and posterior ethmoidal, supplying the ethmoidal cells, the upper portion of the septum, the roof, and the outer wall anteriorly; inferior — the septal branch of the superior coronary artery and a branch of the descending palatine artery coming up through the incisor foramen; posterior — the sphenopalatine, giving its nasopalatine branch to the septum and also supplying branches to the ethmoidal cells, frontal and maxillary sinuses, and outer wall of nose, the Vidian and pterygopalatine going to the posterior portion of the roof, and the descending palatine giving branches to the posterior portion of the inferior meatus and posterior end of the inferior turbinated bone. The veins, like the arteries, are in three sets: the superior are formed by the anterior and posterior ethmoidal and some smaller veins passing upward through the foramen in the cribriform plate, or foramen ccecum, to the longitudinal sinus; the inferior communicate with the facial veins through the anterior nares; the posterior drain upward and backward through the sphenopalatine foramen into the pterygoid plexus. The lymphatics drain either anteriorly on the face or posteriorly through the deep lymphatics of the neck. Therefore, acrid secretions causing ulcerations of the anterior nares are liable to be accomi)anied by swelling of the submaxillary lymphatic deeper nasal cavities. Nasal hypertrophies are enlargements of the nasal mucous membrane. The mucous membrane of the nose or Schneider ian membrane has columnar ciliated cells on its surface and mucous cells beneath. It is prolonged into the various sinuses and cavities in connection with the nasal fossae. The membrane on the upper third of the septum, the upper portion of the middle turbinated, and the superior turbinated bone, contains the terminal filaments of the olfactory nerve. The membrane over the lower portion of the septum, over the lower edge of the middle, and the o-reater part of the inferior turbinated bones, contains a venous plexus which renders it erectile. On the slightest irritation this portion of the membrane will swell and obstruct the passage of air through the nostrils. Repeated swelling of the membrane of the septum produces thickenings of the septum, which if anterior may be seen through the nostrils, and if posterior by the rhinoscopic mirror. The membrane over the inferior turbinated bones also becomes swollen and enlarged, constituting, if at the forward end, anterior hypertrophy, and if at the posterior extremitv, posterior hypertrophy f Fig. 120). They can be readily seen through the nasal speculum anteriorly and by the rhinoscopic mirror posteriorly. Thev are treated bv appHcations of acids, as chromicand trichloracetic, by the electrocautery, or are snared off with the cold snare. Snaring is more often employed in reducing posterior hvpertrophies, but both the anterior and posterior can be reached bv an electrocauterv point or a knife introduced through a speculum in the anterior nares. The Outer Wall.— The outer wall has on it the three turbinated bonessuperior, middle, and inferior. The inferior is a separate bone, but the middle and superior are parts of the ethmoid bone (Figs. 121 and 122). the nose. The lachrymonasal dnct enters this meatus just below the anterior end A J u "^'^ turbinated bone. It pierces the mucous membrane obliquelv. being guarded by a fold called the valve of Hasner. The opening is not \-isible from the anterior nares and usually it is impossible to introduce a probe into it from them. The middle meatus is between the middle and inferior turbinated bones. The mucous membrane covering the middle turbinated bone lies closer to it than does that of the inferior turbinated bone, so that it is comparati\ely rare that treatment is necessary to reduce it. there is, just anterior to its middle, a rounded eminence, the bulla ethmoidalis. In it is an opening for the middle ethmoidal cells. Immediately in front is a slit, the Iiiatiis semilunaris, into which open the maxillary sinus {ajitmin of HigJimore^ and the anterior ethmoidal cells. The hiatus is continued above as the infundibiihan, which enters the frontal sinus. The relation between the hiatus and the opening into the maxillary sinus is such, in some cases, that it is possible for pus originating in the frontal sinus to discharge into the maxillary sinus. A knowledge of the relation of these parts is essential to those desirous of treating nasal diseases. The superior meatus is comparatively small and lies above the middle turbinated bone. At the anterior edge of the superior turbinated bone is the opening tor the posterior ethmoidal cells. Sometimes there are two or three superior lurbinals. The spheno-ei/imoidalv&cess is the cleft above the superior turbinated bone; into it opens the sphenoidal sinus. In order to examine and reach the openings of any of these sinuses, it is practically necessary to take away a part or all of the middle turbinated bone before they can be exposed to view. When this is done, they can be probed, washed out, drained, etc. (see Fig. 125). The frontal sinuses begin to develop about puberty. They occupy the lower anterior portion of the frontal bone. Their size and extent vary considerably. The usual size is from the nasion below to the upper edge of the superciliary ridges above and laterally from the median line to the supra-orbital notch. These limits may be exceeded considerably. They may go as far out as the middle of the upper edge of the orbit or even nearly to the temporal ridge. The anterior and posterior walls are separated a distance of 0.5 to I cm. The distance which they extend back over the orbit and upward also varies. The two sinuses are separated by a partition which is often to one side of the median line, so that it is apt to be encountered in opening the sinus through the forehead. The two cells often differ greatly in size and may be divided into various recesses by incomplete septa. They have the infundibulum as their lower extremity, which passes into the hiatus semilunaris beneath the middle turbinated bone and empties into the middle meatus. The frontal sinuses are frequently the seat of suppurative inflammation. This gives rise to pain and tenderness in the supra-orbital region and to a discharge from the corresponding nostril. This discharge can be seen coming from beneath the anterior extremity of the middle turbinated bone. Owing to the proximity of the opening into the maxillary sinus, pus, coming down the hiatus from the frontal sinus, may pass mto the maxillary sinus, thus simulating disease of that cavity. In order to wash out the sinus, cocaine may be first applied to shrink the nasal membrane ; then sometimes one is able to pass a probe or irrigating tube into the hiatus semilunaris and thence up into the sinus. By removing the anterior extremity of the middle turbinated bone access to the hiatus semilunaris is more readily obtained. In certain cases the frontal sinus is opened either through the supra-orbital region or entered through the roof of the orbit at its inner upper corner. The glabella is the depression in the median line separating the superciHary ridges. In operating on the sinus from in front, the opening is to be made just to the outer side of the glabella in order to avoid the septum between the sinuses. In curetting the sinus, the thinness of the upper and posterior wall separating it from the brain, and of the lower wall or roof of the orbit, should be borne in mind, otherwise they are apt to be perforated. The sinus may be divided into recesses by partial septa projecting from anterior wall has been cut away to expose the interior of the sinus. the sides. Drainage into the nose is obtained by passing an instrument from above downward through the anterior ethmoidal cells. In entering the sinus from below from the outside, the opening is made at the extreme anterior upper edge of the orbit, perforating the bone in a direction upward and inward. The opening into the sinus may be enlarged from within the nose by first inserting a probe to protect the brain and posterior wall and then chiselling or gnawing away the bone in front so that easy access is obtained through the nose for drainage, packing, etc. The ethmoidal sinuses or cells, three in number on each side, anterior, middle, and posterior, lie between the sphenoidal sinus posteriorly, and the lower extremity of the frontal sinus anteriorly. The anterior cells lie in front of or just above the hiatus and open into it. The middle lie just posterior to the hiatus and open into the outer wall of the middle meatus, perforating the bulla ethmoidalis^ which is a rounded projection on the outer wall beneath the middle turbinated bone. The posterior cells open still farther back beneath the superior turbinated bone in the superior meatus. In disease of these cells, pus from the middle and anterior ones will show in the middle meatus; from the posterior cells in the superior meatus. In this latter case it is to be detected posteriorly by means of the rhinoscopic mirror. Access to the cells is obtained by removing the middle turbinated bone. This is done by dividing it into two pieces by a transverse cut with forceps or scissors and then removing the two halves with a snare. By means of probes, curettes, and forceps, the openings into the cells may Fig. 125. — Probes introduced into the frontal, maxillary, and sphenoidal sinuses. The anterior portion of the middle turbinate has been removed. be discovered and enlarged as thought necessary. The region of the ethmoidal cells is that from which mucous polypi of the nose take their origin. They are a common accompaniment of suppuration of the accessory nasal cavities. ' They are usually removed by snares introduced through the anterior nares or more rarely by forceps. Caries affecting the anterior cells may extend into the orbit and the pus may form a fluctuating tumor above the inner canthus of the eye. Care should be taken not to mistake a meningocele for such a tumor. The sphenoidal sinuses are the most posterior, lying still farther back than the ethmoidal. They open into the spheno-ethmoidal recess above and posterior to the superior turbinated bone. Discharge from them goes into the pharynx and is to be seen with the rhinoscopic mirror. They can be reached by first removing the middle turbinated bone and then introducing a probe upward and backward from the anterior nares for a distance of 7.5 cm. (3 in. ) in women and 8 cm. in men. They can be drained by cutting away their anterior wall with punch forceps introduced through the anterior nares. The maxillary sinus lies beneath the orbit and to the outer side of the nasal fossae. It is the seat of tumors, often malignant, and inflammation; the latter accompanied by an accumulation of mucus or pus. The walls of the sinus are thin, so we find tumors bulging forw^ard, causing a protrusion of the cheek. They press inward and obstruct the breathing through that side of the nose, or they push upward and cause protrusion of the eye by encroaching on the orbit. In operating on these tumors, the superior maxilla is usually removed; the lines of the cuts through the bones being shown in Fig. 64. In prying the bone down posteriorly, it may not be torn entirely away from the pterygoid processes and some plates of bone may be left attached. This should be borne in mind in operating for malignant growths. The sphenoidal cells are behind the upper posterior portion of the maxillary sinus, therefore in operating on Meckel's ganglion, if too much force is used in breaking through the posterior wall of the antrum, the instrument may pass across the sphenomaxillary fossa, a distance of about 3 mm. , and open the sphenoidal sinus. The infra-orbital nerve is usually separated from the cavity of the sinus by a thin shell of bone. At the upper anterior portion of the sinus there may be a small cell between the bony canal in which the nerve runs and the bony floor of the orbit. The superior dental ner\'es reach the upper teeth usually by going through minute canals in the bone, but sometimes, particularly the middle set supplying the bicuspid teeth, may run directly beneath the mucous membrane, and thus be irritated by troubles originating within the sinus. The inflammatory and infectious diseases of the sinus originate either by extension from the nose or the teeth. The sinus opens into the nose by a slit-like opening into the middle meatus about its middle,posterior to the hiatus semilunaris and 2. 5 cm. above the floor of the nose. When the opening is close to the hiatus, liquids may run into it from the hiatus. The bone beneath the hiatus and opening almost down to the floor of the nose is quite thin, so that the sinus can readily be drained by thrusting a trocar and cannula through the outer wall of the nose into the sinus just below the hiatus semilunaris. The sinus is also opened from the front through the canine fossa to the outer side of the canine tooth. This opening affords direct access to the cavity, but is some distance above the floor, thus it does not drain the cavity completely. The roots of the upper teeth project into the antrum forming elevations, usually covered by a thin plate of bone. This is particularly the case of the first and second molars. Disease of the roots of these teeth frequently infects the antrum and drainage is often made through their sockets. THE MOUTH AND THROAT. The lips are formed mainly by the orbicularis oris muscle with its subdivisions and the accessojy facial ;;??c^<:/6'^ (buccinator, levator and depressor anguli oris, levator labii superioris, levator labii superioris akeque nasi, the zygomaticus major and minor, and the depressor labii inferioris). The orbicularis oris is attached tc the superior maxilla in the incisor fossa above the second incisor tooth and also above to the septum. In the lower lip it is attached to the mandible beneath the second incisor tooth. The lips contain, beside muscular tissue, some areolar tissue, arteries, veins, and Ivmphatics. The muscular fibres are inserted into the skin. The mucous membrane lining the lips has lying beneath it some mucous glands. They sometimes become enlarged and form small, shot-like, cystic tumors containing mucus. Affections of the Lips. — The lips are affected by wounds, angioma or blood tumor, cancer {epithelioma), and clefts ( harelip). Wounds of the lip when properly approximated heal readily on account of the free blood supply. The arteries sup- plying the lips are the siipcrior and inferior coronary branches of the facial. They are given off about opposite the angle of the mouth and pierce the muscle to run beneath the mucous membrane about midway betwen the edge of the lip and its attachment to the gums or nearer the free border of the lip. Therefore, in operating on the lip, the artery should be looked for in this situation and not toward the skin surface or in the substance of the lip. The superior coronary sends a branch to the nasal septum, called the inferior artery of the septum. In the sulcus between the lower lip and chin lies the inferior labial artery. The bleeding from this branch is not so free as that from the coronary arteries, because the anastomosis across the median line is not so marked. Angioma. — The blood-vessels, mainly the veins, of the lips sometimes become enlarged, forming a large protrusion. This may be noticed at or soon after birth as a dusky blue, slightly swollen spot on the lip. As the child grows the swellingenlarges. Sometimes it enlarges rapidly and operation is necessary to check its growth; otherwise it may involve a large portion of the face and prove incurable. It is composed of dilated veins with thin walls and large lumen. It does not pulsate and disappears under pressure, only to return when this is removed. It is treated by excision. The thin skin is dissected off and the growth cut away from the tissues beneath, the bleeding being controlled by pressure, haemostats, and ligatures. In from the lips to the submaxillary lymph-nodes and then to the nodes along the great vessels of the neck. It is in these regions that lymphatic infection is usually seen. The middle of the lower hp is drained into a node in the submental region in front of the submaxillary nodes. This also is sometimes involved. In operating for cancerous Cleft or harelip is so named from its resemblance to the lip of a hare. It is a deformity due to lack of development, in which the lip is cleft or split from the "mouth up into the nostril, and sometimes even back through from above to form the middle portion of the nose, upper lip, and upper jaw. It forms a bone known as the premaxilla and bears the incisor teeth. From the sides spring the nasal and maxillary processes. These join together as one process and grow toward the premaxilla. If this process fails to reach the premaxillary Paralysis of the lips is due to interference with the functions of the seventh nerve. The muscles of the face and lip are supplied by the seventh or facial nerve. This is frequently paralyzed, for owing to its tortuous passage through the temporal bone in the canal of Fallopius it is injured in fractures of the base of the skull and becomes affected from middle ear disease or neuritis. When paralyzed, the muscles of the lips, both upper and lower, on the affected side, droop. The drooping of the lower lip may allow the saliva to run out of the mouth. It is also impossible for the patient to pucker his mouth, as in whistling. If the lesion of the facial nerve is inside the skull and not in the Fallopian canal, \}a& great petrosal rierve and some of the palatal muscles will be paralyzed, the voice will be altered and swallowing interfered with. The depressor labii inferioris instead of receiving its nerve supply from the supramandibular branch of the facial, frequently is supplied by the inframandibular branch; pressure or injury of this branch in enlargements of or operations on the submandibular lymph-nodes has produced paralysis of the muscle with a peculiar alteration of the facial expression, well shown (see Fig. 132) by a case of Dr. McDowd {Actuals 0/ Surgery, July, 1905). Mouth.. —Sicjface Anatomy. — In looking into the mouth, one sees the tongue below and the roof above, surrounded in front and on the sides by the teeth. On each side are the inner surfaces of the cheeks and posteriorly are seen the uvula, the arches of the palate, and the pharynx. On the mucous membrane of the cheek, opposite the second upper molar tooth, is a small papilla in the top of which opens the duct of the parotid gland. A small probe can be inserted into it and passed outward and backward toward the gland. Tongue. — The tongue is covered with a mucous membrane which is modified skin; therefore it is subject to the same diseases as the skin. It is covered with papillae of three kinds — the filiform^ fiingifontt, and ciraanvallate. The filiform are the smallest and most numerous and form a sort of ground-work in which the others are imbedded. The fungiform are larger and fewer in number and are scattered on the dorsum, sides, and tip of the tongue among the filiform. The circumvallate, seven to twelve in number, form a V-shaped row at the base of the tongue. In the eruptive fevers, particularly scarlet fever, the tongue gets very red and the papillae become enlarged, forming what is known as the strawberry or raspberry tongue. Just beyond the apex of the circumvallate papillae in the median line is the foramen ccBcum. It is sometimes patulous for a short distance and is the upper extremity of the remains of the thyroglossal duct. On the posterior portion of the tongue behind the circumvallate papillae, on each side of the median line, is a mass of adenoid tissue which forms what is known as the Ungual tonsil. It sometimes becomes hypertrophied and is then cut off with a specially curved tonsillotome just as is done with enlarged faucial tonsils. Running from the base of the tongue to the epiglottis are three folds, called the median and lateral glosso-epiglottic folds. each side. On turning the tip of the tongue up (Fig. 135), a fold of membrane, \hQ.fr(zniun, is seen extending from the under surface to the floor of the mouth beneath. In newborn children, this fraenum appears sometimes to be too short, hence the name tonguetie. In cutting it, the split end of a grooved director is placed over the fraenum and opening of the larynx. and the tongue pushed back. This makes the fr^num tense and it can readily be snipped with the scissors. Care should be taken not to cut too deeply, or the ranine artery may be cut and cause troublesome bleeding. Running across the floor of the mouth, between the teeth and tongue, parallel to the alveolus, is the sublingual ridge, formed by the sublingual gland. This gland lies on the mylohyoid muscle beneath and the lower jaw in front. On each side of the frienum on the sublingual ridge is a papilla into which the duct of the submaxillary gland, Wharton' s duct, opens. Opening into Wharton's duct, or by a separate duct into the same papilla, is the duct of the sublingual gland, called the duct of Rivimis or Bartholin. The superficial portion of the gland opens on the sublingual ridge to the outer side of the papilla by a number of small ducts, called the ducts of IValther. is usually restricted to those of the submaxillary and sublingual glands. The mylohyoid muscle forms the floor of the mouth and these cysts lie on it beneath the tongue and between the tongue and the gums (Fig. 136). If the cyst is large it causes a protrusion or swelling beneath the jaw. The bulk of the submaxillary gland lies on the side of the mylohyoid muscle nearest the skin; only a small portion of it winds around the posterior edge of the muscle. Therefore, cysts involving the substance of the gland would show in the submaxillary region of one side. If, however, the duct were obstructed fas by a calculus) it would form a cyst, which would bulge into the mouth beneath the tongue and be called a ranula. The sublingual gland is usually the starting point of these cysts, and it will be seen that as they enlarge they push the ranine artery with the tongue backward and are only co\'ered by the mucous membrane. On this account there is little or no danger in operating on them. They are either dissected out or the front wall of the cvst cut away and the interior cauterized or packed with gauze to promote the formation of granulations. The jaw-bone is in front of them and the mylohyoid muscle beneath. Posteriorly lies the duct of the submaxillary gland and the ranine artery. Carcinoma of the tongue i a modtxately frequent disease and as the to .gue is covered by modified skin, the ncer is of epithelial type. It begins on the surface of the tono-ue either by a change in the epithelial covering or else in fissures or ulcers at its edges. The lymphatics of the tongue pass to the submaxillary nodes beneath the jaw and thence to the deep cervical nodes along the great vessels or direcdy to the latter without passing through the submaxillary nodes. If the disease exists for any length of time, these are the nodes that become infected. They are only to be reached by an incision in the neck. artery on the side to be removed is sometimes ligated in the neck ; this cuts off the blood supply to that side and there is practically no bleeding. There is very little anastomosis between the vessels of the two sides of the tongue. The arteries run lengthwise through the tongue, so that in glossitis or inflammatory swelling of the tongue, incisions should always be made longitudinally into it. The ligation of the lingual artery will be found described in the section on the neck. As the lingual arterv passes above the hyoid bone, it gives of? xX.'i first branch, the hyoid. It is quite small and goes above the hyoid bone superficial to the hyoglossus muscle. The lingual then goes beneath the hyoglossus muscle and near the posterior edge gi\-es of? its second branch or dorsalis linguce. In excision, the tongue is usually cut through on the distal side of the dorsalis linguae artery. When this is the case, the bleeding which occurs from the branches of the dorsalis linguae is not marked because it is not a large artery. In order to draw the tongue out, it must be loosened posteriorly by cutting the anterior pillars of the fauces and palatoglossus muscle, and anteriorly at the fraenum by cutting the geniohyoglossus muscle. By drawing the tongue up, the ranine artery B out of the way and there wih be only sHght bleeding from small branches . , ; mal, which comes from the main trunk at the anterior edge of the hyomuscie. F: .m this point forward to the ti; , the lingual artery is called the The tongue having been loosened and prse cut through the mucous membrane behir ; tissues aside with a blunt instrum<Brit, exp lymg together beneath the mucous membrane. . growth removed. Submaxillary duct Fig. 138. — The cheek has been split, the tongue drawn forward, and the mucous membrane removed from its under surface, exposing the ranine artery and vein, the lingual and hypoglossal nerves, the sublingual gland, the submaxillary ganglion, and the duct of the submaxillary gland. the jaw. The roof of the mouth is formed by the hard palate and the soft palate ; the former comprising about three-fourths and the latter one-fourth. The hard or bony palate is composed in its anterior two-thirds of the palatal processes of the superior maxillary bones, and in its posterior third of the palatal bones. In the median Hne close to the incisor tooth, in the dried skull, is the anterior or nasopalatine fo7'amen. This is subdivided into four foramina, two lateral and two anteroposterior. The former, called the foramina of Stenson, transmit the terminal branches of the descending palatine arteries ; of the latter, caWedthQ forajnina of Sca7pa, the anterior one transmits the left nasopalatine nerve, and the posterior one the right nasopalatine nerve. The soft tissues of the roof of the mouth are thicker than they appear to be, so that when they are raised, as in operating for cleft palate, they form quite a thick layer. Infection of the roof of the mouth when it occurs is usually by extension from neighboring diseased teeth, abscesses being sometimes produced. The blood supply of the roof is of importance in relation to the operation for cleft palate (staphylorrhaphv) (Fig. 139). The blood comes anteriorly from the nasopalatine arteries and posteriorly from the descending palatine arteries, which come down through the pterygopalatine canal from the internal maxillary artery and make their appearance on the hard palate at the posterior palatine foramen. This foramen is on the roof of the mouth opposite the last molar tooth and 0.5 cm. to the inner side and in front of the hamular process (Fig. 140). This hamular process can be felt just pos- terior and to the inner side of the last molar tooth. If, in operating for cleft palate, the tissues are loosened from the bone too close to the hamular process, this artery may be torn near its exit from the foramen, in which case the bleeding is very free. To control it, the canal can be plugged with a slip of gauze. In detaching the soft palate from the posterior edge of the hard palate, it should be remembered that this attachment is quite strong. Not only are the muscles of the soft palate themselves attached to the bone, but the pharyngeal aponeurosis which lies under the mucous membrane on the posterior or upper surface of the soft palate is also attached to the bone. pillar runs from the soft palate to the tongue and is formed by the palatoglossus muscle. The posterior pillar runs from the soft palate downward to the sides of the pharynx and is formed by \h^ palatopharyngeus miLScle. In front of these arches and running from the roof of the mouth opposite the posterior edge of the last molar tooth downward to the posterior edge of the alveolar process of the lower jaw is an elevation of the mucous membrane which shows the line of junction of the hard and soft palates. Faucial Tonsils. — Between the pillars of the fauces lie \\\q. faucial tonsils. They are limited above by the sulcus, called the supratonsillar fossa, formed by the approximation of the pillars and a fold of mucous membrane, called the plica triangularis (His), running downward from the anterior pillar and often blending with the tonsil. Below they extend a variable distance, necessitating depression of the tongue with a spatula in order to make their lower limit accessible. They lie opposite the angles of the jaw on the pharyngeal aponeurosis (p. ii6) with the superior constrictor muscle and bucco-pharyngeal fascia outside. A knowledge of their structure is essential to the proper treatment of their diseases. The tonsils are oval in shape and when normal in size project but little beyond the pillars of the fauces. They are about 2.5 cm. long by i cm. wide and consist of about a dozen recesses or crypts formed by the folding inward of the mucous membrane. From these crypts follicles extend. The walls of the crypts contain adenoid tissue as well as mucous glands. The tonsil is held together by connective tissue which is continuous with its capsule and the submucous fibrous tissue of the pharynx. This capsule rests on and blends more or less completely with the fibres of the pharyngeal aponeurosis. On this account while an enlarged tonsil can at times, usually in young children, be shelled out of its bed, especially its upper portion, at others it is necessary to dissect or cut it out by means of a knife, scissors, tonsillotome, or snare. Fig. 143. — Point of puncture for tonsillar abscess. " If an imaginar\' horizontal line is drawn across the base of the uvula, and another vertically along the anterior faucial pillar, they will intersect at a point over!>-ing the supratonsillar fossa. Just external to this is itie best point for opening a quinsy." — St. Clair Thomson, M.D., Brit. M. J., March 25, 1905, p. 645. ascending pharynigeal branch of the external carotid, the asceyiding palaiitie and tonsillar brayiches of the facial, the to7isillar branch of the dorsalis lijigicce, and the descending palatine branch of the internal maxillary. Ordinarily, these branches are small, but sometimes some of them are large and may cause troublesome hemorrhage. In inflammation of the tonsils, these vessels of course are larger than usual. The tonsils are subject to inflammation and tumors. Tumors are rare; they grow inward and obstruct breathing and swallowing. Attempts are made to remove them either by scraping, cutting, snaring, or burning them with the electrocautery from the mouth; or they are sometimes removed through an external incision through the neck. This latter is a very se\-ere procedure on account of the depth of the tonsil and the number of important structures which overlie it. Tonsillitis or quinsy is an inflammation of the tonsils which leads to the formation of an abscess. In mild cases the crypts or lacunae are affected, forming a follicular or lacunar tonsillitis. In this form epithelium and inflammatory matter are poured into the follicles and distend them, often showing as white plugs protruding from the mouth of the crypt. In its treatment, in addition to local applications, surgeons enlarge the openings into the crypts with a small knife and scoop the contents out with a sharp spoon. In severe cases, the whole substance of the tonsil and even the connective tissue around it are involved in the inflammation, forming 2, parenchymatous tonsillitis. It frequently proceeds to the formation of pus. When this forms in the substance of the tonsil it may break into a follicle and discharge into the throat. An abscess of the tonsil may becom.e quite large, bulging toward the median line, and on breaking may cause suffocation by passage of the pus into the larynx. If, as is usually the case, the pus involves the tissue around the tonsil, forming a peritonsillar abscess, it pushes upward behind the anterior pillar into the supratonsillar fossa and bulges forward, stretching the pillar over it. To evacuate this pus an incision should be made directly anteroposteriorly, with the flat side of the blade parallel with the edge of the pillar, or a slender pair of haemostatic forceps may be used. A centimetre and a quarter (}4. m. ) is deep enough usually to plunge the knife; the point should not be pointed outwardly but directly backward. The incision should be just above the upper and lateral edge of the anterior pillar (Fig. 143;. Some small vessels may bleed, but this will either stop spontaneously or may be controlled by packing. The ascending pharyngeal artery lies beneath the tonsil. The tonsil lies on the pharyngeal aponeurosis and the superior constrictor muscle, while the as- carotid artery. cending pharyngeal artery and external carotid lie outside of them, so that both structures would have to be cut before the vessels would be wounded. The internal carotid artery lies still deeper (2 to 2.5 cm. ) behind and external to the tonsil. It is usually well out of harm's way unless dilated (see page 123, Fig. 156), but the pus may burrow mto it and cause fatal hemorrhage. Sometimes pus may burrow through the constrictor muscle and enter the tissues of the neck. In severe tonsillitis the deep lymphatics beneath the angle of the jaw become enlarged. Hypertrophy of the tonsils is common and is treated by removing them entirely or level with the palatal arches. An instrument called the tonsillotome is used, or it IS done v^ath a knife or scissors or snare. Fatal bleeding has followed this ' operation. The blood supply to the tonsil has already been given. If the bleeding is so 1^1!° ^^^^^^ ^^^ ^i^^ of a patient, the external caro'tid artery should be ligated as all the vessels supplying the tonsil are derived from it. Enucleation is performed by grasping the tonsil with toothed forceps, drawing it out, and cutting it loose with knife, scissors, or snare from its attachments to the pillars and aponeurosis beneath. Sometimes after loosening its attachments above it is torn loose or shelled out, from above downward, by the hnger or a blunt instrument. On account of the attachment of the capsule to the pharyngeal aponeurosis the tonsil cannot always readily be ' ' shelled out ' ' and portions may remain and require to be removed with the forceps and scissors or tonsillar punch. The incision through the mucous membrane should begin posterior to the free edge of the plica triangularis — not anterior. The tonsil grows more adherent to the deep structures as the child increases in age. It is a disagreeable and bloody procedure and is often done under a general anaesthetic. Retropharyngeal abscess may arise from any one of three causes, — cervical caries, suppuration of lymphatic nodes, or extension of pus from the middle ear through the canal for the tensor tympani muscle. The pharyngeal aponeurosis lies under the mucous membrane and between it and the constrictor muscle. It is thick above and fades away below. It fills up the gap above between the superior constrictor and the base of the skull and is attached to the pharyngeal spine on the under surface of the basilar process. It is lined with the mucous membrane and covered by the constrictor muscles. Over all is the buccopharyjigeal fascia, a thin layer continuous forward over the buccinator muscle and separated from the prevertebral fascia by very loose connective tissue. The space between these two layers of fascia is known as the retropharyngeal space and pus can follow it downward behind the pharynx and oesophagus into the posterior mediastinum. Retropharyngeal abscesses occur external to the pharyngeal aponeurosis and bulge into the throat. On account of the looseness of this aponeurosis and its lack of firm attachments, these abscesses may not bulge forward as a distinct circumscribed swelling, as abscesses do elsewhere, but are more apt to gravitate downward and hang in a loose bag-like manner opposite the base of the tongue. They are not easily felt, being so soft, and to see them properly the tongue should be held down with a tongue depressor. In looking for their origin, a careful examination of the spine should be made to detect the possible existence of spinal caries or Pott 's disease, and the ear should be examined for suppurative otitis media. The lymph-nodes, which often give rise to these abscesses, especially in children under two years of age, are one or two lying on the anterior surface of the vertebral column between it and the pharyngeal aponeurosis and constrictor muscles. In evacuating these abscesses the safest way is to place the child on its back with the head hanging; the pus then gravitates toward the roof of the pharynx. The tongue is held out of the way with a tongue depressor and the abscess can be well seen and incised. Raising the body causes the pus to flow from the mouth. The pus may not only point in the mouth but can work its way laterally. In such a case it may pass out behind the sheath of the great vessels and make its appearance, as I have seen it, behind the posterior edge of the sternomastoid muscle. If a tumor is present in this situation, the pus may be evacuated by an incision at this point and the abscess drained there instead of making an opening through the pharynx. This, of course, tends to guard against infection from the mouth. Lingual Nerve. — The lingual ner\'e or gustatory branch of the fifth can be readily exposed in the mouth. On looking into the mouth, a fold can be seen going up and back just behind the last molar tooth. This is formed by \\\& pterygomandib^dar ligament, running from the tip of the internal pterygoid plate to the posterior extremity of the mylohyoid ridge and joining the buccinator with the superior con- last molar tooth, will lead one down to the lingual nerve close to the bone. The mandibular nerve is also reached through an incision running from the last upper to the last lower molar tooth. The finger is introduced and the spine of Spix felt at the inferior dental foramen. The nerve and artery enter the mandible at this point, the artery being below and posterior. The operation of Paravicini on this nerve through the mouth is unsatisfactory on account of the lack of proper exposure. It is better to attack the nerve from the outside as detailed on page 60. PHARYNX. The pharynx is the common air and food tract that lies behind the nose, mouth, and larynx. It extends from the base of the skull above to the cesophagus below. Its lower end is at the cricoid cartilage, which is opposite the sixth cervical vertebra. In passing an instrument directly backward through the nose, one strikes the base of the skull or interval between the basilar process and the atlas. In looking into the throat through the mouth, one is level with the body of the second vertebra. If, by means of a hook, the soft palate is raised or pushed aside and the head tilted slightly backward one sees the anterior tubercle of the atlas. The rounded projection can the two Eustachian tubes, the mouth, the larynx, and the oesophagus. Posterior Nares or Choanae. — These can readily be seen by means of the rhinoscopic mirror. They are separated by the posterior edge of the bony septum, the vomer bone. They are 2.5 cm. (i in. ) long and 1.25 cm. wide, hence are of sufficient size to allow a well lubricated little finger to pass into them from the anterior nares. The tip of an index finger can be inserted through the mouth below, hence the entire length of the lower meatus of the nose and upper surface of the soft palate can be palpated. Projecting from each lateral wall toward the septum are the rounded posterior ends of the middle and inferior turbinated bones. Sometimes, high up, the posterior end of the superior turbinate can be seen. The posterior end of the inferior turbinate is frequently enlarged by a swelling of its membrane, forming a posterior hirbi- 7iate hypertrophy. Not only does the mucous membrane of the inferior turbinate bones become enlarged, but that on the septum likewise. This constitutes hypejirophy or thickening of the septum. A polypus may project from the nasal cavities backward into the throat. The posterior nares are quite a distance anterior to the edge of the soft palate, hence it is extremely difficult to make applications by way of the mouth. A much easier way is to make them through a tube introduced into the nose, or even, as when the electrocautery is used, without a protecting tube. Eustachian Tube. — On each side, at a point about opposite the inferior turbinals, are the orifices of the Eustachian tubes with the fossa of Rosenmii/ler above. The Eustachian tube runs from the upper portion of the pharynx to the middle ear, opening just behind the tympanic membrane, on the anterior wall. It is about 4 cm. long, 2.5 cm. being cartilaginous Tpharyngeal portion) and 1.5 cm. being bony. At the junction of the bony and cartilaginous portions the lumen is slightly diminished, forming the isthmus. The tube runs upward, backward, and out\\'ard. The mucous membrane of the throat is continuous with that lining the tube and tympanum, therefore inflammation of the pharynx travels up the tube and affects the middle ear. This is the manner in which earache or inflammation and suppuration of the middle ear is produced. This also explains why impairment of hearing so often accompanies or follows sore throat. When the tube is in a healthv condition, the air finds free access to the ear, in swallowing, sneezing, etc. This is readily demonstrated by closing the nostrils and swallowing, when the pressure of air outside the ear drum will be distinctly felt. When inflammation affects the linins^ mem- brane it swells and blocks up the tube and prevents the free access of air to the ear. If the swelling is not too great, air can be forced from the throat to the ear by three different means. The distention of the middle ear by air is called inflating it. The method of Valsalva consists in holding the nostrils and mouth shut and blowing. If the air enters the middle ear, the tympanic membranes will be felt to bulge outward. The method of Politzer is to have the patient hold a small quantity^ of water in the mouth. The nozzle of a rubber bag is introduced into one nostril, closing both nostrils with the fingers and thumb of the unengaged hand. On telling the patient to swallow, the bag is compressed and the air enters the Eustachian tube. As the patient swallows, the tensor palati muscle opens the mouth of the tube and as the bag is compressed the air rushes up the tube. Sometimes the vapors of ether, chloroform, etc., are used. The third method is by the Eustachian catheter. The Eustachian catheter is a small, hard rubber or silver tube, slightly bent at the extremity and long enough to reach from the anterior nares in front to the posterior wall of the pharynx. The end of the catheter having been inserted into neighboring structures. the mouth of the Eustachian tube, air is blown in with the Politzer air-bag. By means of a rubber tube going from the patient's ear to the surgeon's ear, the air can be heard entering the middle ear. Introducing the Eustachian Catheter. — In introducing the Eustachian catheter, the tip of the nose is to be tilted upward until the anterior nares are raised to the level of the floor of the nose. The tip of the catheter is then passetl first upward (Fig. 152), then along the floor until it is felt to pass beyond the soft palate and strike the posterior wall of the pharynx (Fig. 153). It is usually advised to enter the catheter in a vertical position and then change to a horizontal one as soon as the beak passes over the elevation which marks the separation of the vestibule of the nose from the interior. If this method is used, care should be taken to keep the tip of the catheter on the floor of the nose and not pass it up in the region of the middle turbinate bone. There are three ways of introducing the beak of the catheter into the mouth of the tube after it is felt touching the posterior pharyngeal wall. The first is to withdraw the beak about 2 cm. away from the wall of the pharynx and then turn it upward and outward, pushing it a trifle onward. The second way is to turn the beak directly outward and draw it forward, when it can be felt passing over the cartilaginous opening of the tube. The third way is to turn the beak inward and draw it forward until it catches behind the septum. This is opposite the anterior edge of the mouth of the tube. The beak is then rotated downward and then upward and outward into the tube. Liquids and sprays are sometimes injected into the ear through the catheter; bougies are also passed into the tube in the same manner as the catheter or, if flexible bougies are used, they are passed through the catheter. As the tip of the bougie passes into the bony portion of the canal, the constriction of the isthmus can be felt 2.5 cm. up from its mouth. The bougie should not be passed farther than 3 cm. into the tube, otherwise, if the tympanum is entered, the ossicles are apt to be injured. third step. from ulcerative processes due to syphilis, caustics, etc. There is rarely obstruction downward, so that these patients can usually swallow, but the cicatrices contract the opening upward, and the soft palate, its arches, and the walls of the pharynx may be all bound together in one cicatricial mass, preventing, as I have seen, all respiration through the nose. This condition is an exceedingly diiftcult one to remedy, as the contraction tends to recur even after the most radical operations. straight tongue depressor is used, Kirstein has shown that in many patients the arytenoid cartilages and even a portion of the vocal cords can be seen. The opening into the larynx can readily be felt by a finger introduced into the mouth. In cases of suffocation from a foreign body, as a piece of meat, it is usually lodged at this point, part of the foreign body being in the larynx and part in the pharynx. It can readily be dislodged by the finger, as I have done in impaction of meat, the result of vomiting in ether narcosis. The forefinger should be thrust its full length into the mouth and throat and swept from side to side. The obstructing body can usually be brushed aside and brought up in front of the finger into the mouth. The opening of the oesophagus is in a line with the long axis of the pharynx; it is at its lower end. The oj)ening of the larynx, on the contrary, is more on its anterior wall. It is for this reason that when an oesophageal tube is introduced, either through the mouth or through the nose, it goes down into the oesophagus and does not enter the larvnx. The oesophagus is narrowest at this point. known as Liischkd s tonsil. It is composed of lymphoid tissue, and when enlarged constitutes the disease known as adenoids. It is not true secreting gland tissue, though it contains some mucous glands. It hangs from the vault of the pharynx in a more or less lobulated mass and when large, in children, obstructs nasal respiration. Mouth-breathing results, the child is apt to snore and make queer sounds when sleeping, and the habit of keeping the mouth open causes a peculiar expression of the face almost pathognomonic of the affection. The blood supply at times is abundant. When adenoids are present, their removal is usually undertaken. A curette is used for this purpose. That known as Gottstein's consists of an oval-shaped ring set at right angles to a long shaft. It is introduced through the mouth and up behind the soft palate. It is then pushed against the vault of the pharynx and posterior w^all and drawn downward cutting and scraping the adenoid tissue away. A much smaller ring curette set on a long, delicate, but stiff handle may be used through the nose for the same purpose. In using the latter instrument, it is common to use an anaesthetic and operate with the head in a hanging position. Free bleeding may occur from this operation. To control it, injections of ice water or a strong alum solution may be tried or gauze may be packed behind the soft palate or pushed in from the anterior nares. A folded pad of gauze may be attached to the thread of a Bellocq cannula and the pad introduced as is done in plugging the posterior nares. A curved forceps with cutting blades is also used to remove this growth. Fossa of Rosenmiiller. — This is the depression above and behind the openings of the Eustachian tubes. The walls of the pharynx are weakest at this point owing to the superior constrictor muscle not coming so high up. Hernia of the mucous membrane sometimes occurs here. When the beak of the Eustachian catheter fails to enter the mouth of the tube it usually enters this fossa. The internal carotid artery runs up the neck outside of the pharynx and opposite the space between the posterior arches of the palate and the posterior wall of the pharynx. It is from i to 2 cm. behind and to the outer side of the tonsils. It is separated from the cavity of the throat by its own proper sheath, by the thin buccopharyngeal fascia covering the constrictor muscles, by the constrictor muscles, the pharyngeal aponeurosis, and the mucous membrane. As the tonsils lie between the pillars of the fauces, in opening a tonsillar abscess the knife is not carried either exposed. The internal carotids are seen to be abnormally tortuous, with a tendency to bulge into the pharynx. behind or through the posterior pillar of the fauces. It is practically impossible to wound a normal internal carotid artery. In old people the internal carotid sometirftes becomes lengthened and tortuous in the same manner as do the temporal arteries. In such cases the artery may form a pulsating swelling behind and projecting farther inward than the edge of the posterior pillar. This I have once seen. It may be mistaken for a true aneurism, as it pulsates and the pulsation is readily stopped by pressure on the common carotid on the outside of the neck. If, however, the possibility of this condition is borne in mind, the diagnosis can readily be made. The pulsating swelling can readily be seen and felt with the finger just behind the posterior pillar of the fauces. The mucous membrane of the nasopharynx is ciliated columnar; that of the lower portion is squamous. It contains racemose mucous glands and follicles or crypts surrounded by lymphoid tissue. It is well supplied with blood-A-essels. It is frequently affected by inflammation or pharyngitis. When the follicles are markedly involved they can be seen studded over the posterior wall of the pharynx. This constitutes a follicular phajyngitis. Not infrequently some ulceration may be present, forming an ulcerative phaiyjigitis. Infection attacks it, as in diphtheritic pharyngitis. Should pus or pharyngeal abscess form around the pharynx, arising from an infection from the oral cavity, the pus occupies the retropharyngeal space between the buccopharyngeal fascia and prevertebral fascia. Its spread upward is limited by the skull; laterally it is limited by the sheath of the carotid vessels; hence it passes downward behind the oesophagus and may enter the posterior mediastinum. Foreign bodies may become lodged at the lower end of the pharynx and at the beginning of the oesophagus. As this is about 15 cm. (6 in.) from the teeth, it is beyond the reach of the finger. Luckily, this is below the opening of the larynx and the need for immediate relief is not so urgent. The larynx extends from the top of the epiglottis to the lower edge of the cricoid cartilage. It is composed of the three large cartilages — epiglottis, thyroid, and cricoid — and three pairs of small ones — the aryte^ioids, the corniciihc laryngis or cartilages of Santorini, and the cuneiform or cartilages of Wj^isberg. it lies opposite the fourth, fifth, and sixth. The larynx being loosely attached varies in relation to the vertebrae according to the position of the head, so that the anterior portion of the cricoid cartilage may be opposite the seventh cervical vertebra in some positions. Epiglottis. — Usually the tip of the epiglottis lies lower than the dorsum of the tongue, so that looking into the mouth it is not seen; it may, however, be brought into view by depressing the base of the tongue and drawing it forward with a long tongue depressor. As the epiglottis rises above the level of the hyoid bone, a cutthroat wound passing above that bone may cut its tip entirely of^. In viewing the epiglottis from above downward it is seen to project somewhat backward in its middle. This is visible in the laryngoscopic mirror and is called the cushion of the epiglottis. Running forward from the epiglottis to the base and the sides of the tongue are three folds of mucous membrane, one median and two lateral, called the glossoepiglottic folds. These form four fossae; those on each side of the median line are called the valleciilcB. In these fossae foreign bodies, such as fish-bones, etc., may become lodged. They are readily seen by the laryngoscopic mirror. The thyrohyoid membrane passes between the hyoid bone above and the thyroid cartilage below ; crossing it is the hyoid branch of the superior thyroid artery. It is a quite small vessel, of little clinical importance, and ordinarily does not reach the median line. The posterior edge of this membrane, running from the superior cornu of the thyroid cartilage to the hyoid bone, is called the thyrohyoid ligament. This ligament has a small cartilaginous nodule in it, the cajdilago triticea. Piercing the membrane on its side are the internal branches of the superior lar}'ngeal nerve and the superior laryngeal vessels. The external branch of the superior laryngeal nerve supplies the cricothyroid muscle, while the internal is the nerve of sensation of the larynx. portion of its anterior edge, commonly called "Adam's apple." Since the cartilage is large and strong and as age advances tends to calcify, cut-throat wounds, while opening the cavity within, do not often pass entirely through the cartilage. This cartilage may be fractured by violence. This is often fatal on account of the blood flowing into the trachea and lungs below or on account of oedema of the lining mucous membrane causing obstruction of the breathing. Thyrotomy or division of the thyroid cartilage in the median line is sometimes done to remove foreign bodies or new growths. In these cases the voice will be likely to be impaired by the interference with the vocal cords. Cricothyroid Membrane. — The space between the cricoid and thyroid cartilages is small. This is due to the increase in width of the cricoid as it proceeds backward. The space is readily felt on the living subject between the thyroid above and the cricoid beneath ; the membrane passes between them. It is crossed by a small branch of the superior thyroid artery, the cricothyroid. It is not large enough to cause serious trouble. Introducing a tube through this membrane constitutes the operation of laryngotomy. This operation is but seldom performed. The space is too small in many cases, the opening is not made sufficiently low and it is too close to the vocal cords. It is an operation of emergency. It is much easier to make a quick opening at this point than it is in the trachea below, as it is more superficial and is held steady in place by the cartilage above and below it. Even in adults the space is sometimes too small to introduce a tube without force and the operation should never be done below the age of thirteen. On account of the membrane being nearer the surface than is the trachea, a shorter tube should be used. Before introducing the tube, care must be taken that the mucous membrane has been thoroughly divided, as otherwise the tube will push it before it and slip between the mucous membrane and the cartilage and, therefore, not enter the cavity of the larnyx. Cricoid Cartilage. — This is much larger posteriorly than anteriorly and fills the space between the posterior edges of the thyroid cartilage. Its outside diameter is larger than that of the trachea, hence it can readily be felt and forms one of the most important landmarks on the front of the neck. It is about opposite the sixth For the parts concerned in tracheotomy see the section on the neck. Laryngoscopy. — The interior of the larynx is examined by means of a small mirror, i to 3 cm. in diameter, introduced through the mouth and placed just below the uvula at an angle of a little more than 45 degrees. The opening of the larynx is not directly beneath the mirror but slightly anterior. The base of the tongue and lingual tonsils, the glosso-epiglottic folds and pouches, and the epiglottis can be seen in front. Posteriorly one sees the two arytenoid cartilages capped with the cartilages of Santorini. Between the arytenoids is the commissure or interarytenoid space. To the front and outer side of the tip of the arytenoid cartilages is the cartilage of Wrisberg, and running from it forward are the a}ycpigIottic folds. To the outer side of the aryepiglottic fold is the depression called the simis pyriforviis. It is here that congenital cervical fistulae sometimes open. Near the middle are seen the two, white, true vocal cords, and to the outer edge of these are seen the false vocal cords. Between these two is the opening of the ventricle of the larynx. The rings of the trachea can readily be seen and not infrequently even the point of bifurcation of the trachea opposite about the second rib. Diseases of the Larynx. — Syphilis affects the larynx and produces ulcers. These may involve almost any portion but usually they are anterior, involving the epiglottis. They are often associated with syphilitic manifestations in the mouth. Tuberculosis affects the posterior portion of the larynx and the bulb-like swellings of the arytenoids are almost pathognomonic. Ulcers when they occur are most marked posteriorly. This affection is associated with a blanching of the mucous membrane of the mouth and the presence of a white frothy mucus, which will lead the laryngologist to suspect the existence of the disease before a view of the larynx is obtained. laryngeal nerve. This nerve supplies the abductor muscles and when paralyzed the cords tend to fall together. The nerve may be injured in operations on the neck or involved in cancer of the thyroid gland, or oesophagus, or in aneurisms. If one cord is paralyzed, the voice is lost temporarily, and when it returns, it is changed in character. Paralysis of both nerves does not cause entire loss of voice because the cords fall together, but may induce suffocative symptoms ending in death. Paralysis of the left vocal cord is beheved by Fetterolf and Norris to be due to compression of the left recurrent laryngeal nerve between the left pulmonary artery and the aorta or the aortic ligament. THE NECK. The neck supports the head. It is a pedestal for the head, and is long in proportion to its thickness; the apparent object of this being to elevate the head and allow it to be moved freely in different directions. The animal is thus better enabled to discover its enemies and to guard itself against them. The various structures of the neck are mostly long, running between the head above and the trunk below. This is the case with the spine, the air- and food-passages, the blood-vessels, nerves, and even some muscles, as the sternomastoid and trapezius. The shorter structures are either the component parts of the longer ones, as the vertebrae of the spine and the rings of the trachea, or are separate organs like the larynx, thyroid, and submaxillary glands. The presence of these latter organs is not dependent on the length of the neck as is that of the' others. In the frog, which practically has no neck, the head being placed directly on the trunk, there still exist both larynx and thyroid gland. In the singing birds the vocal organ or syrinx is placed in the chest at the bifurcation of the trachea. As regards the cervical spine, blood-vessels, air- and food-passages, and muscles, these evidently are proportionate to the length of the neck. In the batrachians or frogs there is but a single cervical vertebra; in the swan there are twenty-five cervical A'ertebrae, and in the fishes none. In man of course the number of cervical vertebrae remains the same. seven, no matter what the length of the neck. From a consideration of these facts we may perhaps state that the neck itself is a subsidiary organ, not of any great importance in itself, but rather in relation to some other portion of the body — that portion being the head. It is the staff which supports the head by means of the cervical spine and muscles. The neck contains the great currents of blood which pass to and fro between the head and trunk. It carries the air- and food-passages, which run from the mouth above to the lungs and stomach below, and incidentally it contains the larynx, the thyroid and submaxillary glands, and some lymphatic nodes. The cerebrospinal nerves of all the body below the head pass either into the neck or through it to the .parts beyond. From these facts it becomes evident that, while the neck in itself may be a subsidiary organ, for our purposes it is of the greatest importance, because interference with its structure either by disease or injury — operative or accidental — may destroy the brain above, by interfering with its nourishment, or the body below, by interfering with the vital functions of respiration and nutrition, or may paralyze it by destroying the conductivity of its nerves. The construction of the neck then should be studied with a \iew of explaining or vinderstanding the diseases and injuries of its various parts and the operations performed for their relief. Injuries and Diseases of the Neck. — Owing to its exposed position the neck is frequently injured by sprains, contusions, cuts, and punctured, gunshot, and all sorts of wounds. The cervical spine may become dislocated or fractured and is frequently the seat of caries. The muscles become contracted, producing torticollis or wry-neck. They may sometimes be ruptured, as in childbirth. The arteries are affected with aneurism, necessitating their ligation. They are also divided in cut-throat cases and wounds. The veins are of importance in almost every operation; bleeding from them is dangerous and may be difficult to control. The lymphatic nodes are more numerovis than elsewhere in the body. Frequently they are the seat of tuberculous or sarcomatous enlargement, necessitating their removal. They may break down and produce wide-spreading and dangerous abscesses, which are guided in their course by the fascias ; hence a knowledge of the construction of the deep fascias of the neck enables us to understand them. The submaxillary and thyroid glands are the seat of enlargement and foreign growths requiring the performance of extensive operations for their extirpation. Enlargement of the thyroid gland constitutes the disease known as goitre. It is also involved in exophthalmic goitre or Graves s or Basedow' s disease. The skifi and subcutaneous tissue become the seat of inflammation and cellulitis. In cases of wounds this cellular inflammation may involve the structures beneath the deep fascia; this occurs in cut-throat and gunshot wounds. The neck is also liable to other affections, such as cysts due to embryological defects. Large cysts are formed called hygromas, also sinuses or fistulae, the congenital fistulce of the neck. The larynx may be the seat of malignant disease; hence its removal is undertaken. The operations of tracheotomy , laryngotomy, and xsophagotomy are also at times necessary. In order to understand these various affections and procedures one must be familiar with the construction of the neck, what composes it, where the various structures lie and their relation to one another. In order to utilize this knowledge we must be able to recognize and identify the position of various structures before the skin is incised, for it is rarely that a case presents itself with a wound that permits a view of the deeper structures; hence the importance of a thorough knowledge of its surface and the structures capable of being recognized through the skin. SURFACE ANATOMY OF THE NECK. For convenience of study we may consider the structures in the median line, and those regions anterior and those posterior to the sternomastoid muscle, between it and the trapezius. The posterior portion of the neck will be described in the section devoted to the back. regions, the szibinental, laryngeal, and tracheal. The submental region extends from the chin to the lower border of the body of the hyoid bone ; it is limited laterally by the anterior belly of the digastric ?nuscle on each side. Ranula and other sublingual tumors cause a bulging in this region and it is frequently occupied by an enlarged lymphatic node, which at times suppurates and forms an abscess. The floor of the space is formed by the mylohyoid muscle and there are no dangerous structures, so that no hesitancy need be had in incising abscesses in this locality nor in removing diseased lymph-nodes. In carcinoma involving the lower lip near the median line these nodes may be afiected and their involvement in such cases should always be looked for. The submaxillary lymphatic nodes farther outward may also be implicated. The tip of the epiglottis projects above the hyoid bone in this region. The laryngeal region extends from the under surface of the hyoid bone to the lower edge of the cricoid cartilage. Laterally it is limited to the space occupied by the larynx. The cricoid cartilage is included in this region as a part of the larynx. The vocal cords are just beneath the most prominent part of the thyroid cartilage. The tracheal region extends from the lower edge of the cricoid cartilage to the top of the sternum. Just above the sternum, between the sternal origins of the stemomastoid muscles, is the suprasternal Jiotck or, as it is called by the Germans, the Jugulum. Laterally the region is limited by the sides of the trachea. the upper and outer portion of the manubrium, the sternoclavicular ligament, and the inner end of the clavicle. The origin of the sternothyroid is wider than that of the sternohyoid and is lower down. It arises from the first piece of the sternum near the median line, below the sternohyoid, and from the cartilage of the first rib. The first ring of the trachea is not covered by any important structure. The second, third, and fourth rings are covered by the istlwuis of the thyroid gland; from here down the inferior thyroid veins may lie on the trachea for at least part of their course. The a7iterior jngu/ar vein may exist either as a single vein in the median line or to one side of it, or one may pass downward on each side of the median line with a communicating branch from one to the other crossing the median line in the suprasternal notch. The cricothyroid artery, a small branch of the superior thyroid, may cross the cricothyroid membrane, but it is usually too small to cause any troublesome bleeding. felt. On pressing the finger into this hollow it rests between the digastric muscles on each side and the mylohyoid muscles beneath. Still deeper than the mylohyoid are the geniohyoid and geniohyoglossus muscles attached to the genial tubercles on the inner side of the mandible. If the lymphatic nodes at this point are enlarged they may be felt. (Fig. 161.) The hyoid bone can usually be readily felt in the median line. If it is not easily discovered in the median line it can be felt by a finger and thumb placed on each side of the neck above the thyroid cartilage. Passing over the hyoid bone the linger then sinks into the space between it and the top of the thyroid cartilage. This space is bridged by the thyrohyoid membrane. Next comes the thyroid cartilage or "Adam's apple." It can readily be seen in adult males and thin people, but in the fat necks of women and children, though it can still be felt, it often cannot be seen. The finger then sinks into the space between the thyroid cartilage above and the cricoid below. They are connected by the cricothyroid membrane, over which runs a small branch (cricothyroid) of the superior thyroid artery. The prominence of the cricoid cartilage can be seen in thin people and if carefully searched for can be felt in almost all cases. It is opposite the sixth cervical vertebra, a most important landmark. From the cricoid cartilage down to the sternum only soft structures can be felt. The sternum projects forward and the trachea inclines backward so that opposite the top of the sternum the trachea is about .2 cm. behind it. _ The distance between the top of the sternum and cricoid cartilage in an adult male is about 4.5 cm. (i3/( in.j. THE CERVICAL TRIANGLES. On viewing the neck from the side the prominent sternocleidomastoid muscle with its thick anterior and thin posterior edge is seen to divide it into two spaces, an anterior and a posterior. They are called the miterior arid posterior cervical triangles. The anterior cervical triangle has for its anterior side the median line of the neck._ Its posterior side is the anterior edge of the sternomastoid muscle. Its upper side is the lower edge of the mandible from the symphvsis to the angle and thence across to the mastoid process. The anterior triangle is further divided into the space above the digastric muscle called the submaxillary triangle,— ixom its containing the gland of that name,— the superior carotid triajigle above the anterior belly of the omohyoid muscle, and the inferior carotid triangle below the omohyoid muscle. has as its upper side the lower edge of the mandible from near its symphysis around the lower edge of the body to the ramus and thence in a straight line across to the mastoid process. Its anterior side is the anterior belly and its posterior side is the posterior belly of the digastric muscle. The submaxillary gland can usually be felt beneath the jaw. Beneath it runs the facial artery to pass o\er the body of the mandible in front of the anterior edge of the masseter muscle. The gland lies on the hyoglossus and mylohyoid muscles, which form the floor of this triangle. It is encased in a sort of pocket formed by a splitting of the deep cervical fascia. The posterior portion of this fascia runs from the styloid process to the hyoid bone and is called the stylohyoid ligament. lymphatic nodes for tuberculous disease, care should be taken to distinguish between them and the submaxillary gland. The tendon of the digastric muscle does not come clear down to the hyoid bone but the loop which binds the two together is sometimes a centimetre or more in length. The lingual artery enters the submaxillary triangle near the apex of the angle formed by the tendon of the digastric. It crosses beneath the posterior belly of the digastric muscle and, particularly if the digastric muscles contract, it may lie close to the tendon. Frequently the search for it is made too high in the triangle and too far away from the hyoid bone. When the submaxillary gland is lifted from its bed the hypoglossal nerve is seen beneath lying on the hyoglossus muscle. The lingual artery lies beneath the hyoglossus muscle and the muscle is cut through in order to find it. The submaxillary region is the seat of Ltidzvig'' s angiyia, a septic inflammation involving the cellular tissues beneath the tongue and jaw around the submaxillary gland and the upper portion of the neck. It is a dangerous affection and may cause death not only by sepsis but also by oedema of the larynx. Dr. T. Turner Thomas {Aniials of Surgery, February and March, 190S;, has pointed out that the infection passes from the inside of the mouth to the submaxillary region outside by following the connective tissue around the submaxillary gland as it winds around the posterior edge of the mylohyoid muscle through the opening existing between this muscle in front and the anterior portion of the middle constrictor of the pharynx behind. The SUPERIOR CAROTID TRIANGLE is limited posteriorly by the sternomastoid muscle, superiorly by the posterior belly of the digastric, and inferiorly by the anterior belly of the omohyoid. The location of the omohyoid muscle can be determined by that of the cricoid cartilage, as the muscle crosses the common carotid' artery about opposite that point. The sternomastoid muscle can be both seen and felt. It is attached above from the apex of the mastoid process to the middle' of the Sternohyoid Fig. 165. — Submaxillary region. The anterior portion of the submaxillary gland is seen winding around and beneath the posterior edge of the mylohyoid muscle. The posterior portion of the gland has been cut away. The posterior belly of the digastric and the stylohyoid muscles have also been removed. superior curved line on the occipital bone. It is attached below by a sternal head to the upper anterior part of the first piece of the sternum, and by a clavicular head to the inner third of the clavicle on its sypgrior^and interior border. Its action will be mentioned in discussing wry-neck. Arteries. — The carotid arteries and their branches are found in this triangle. The line of the carotid arteries is from a mid-point between the mastoid process and the angle of the jaw to the sternoclavicular articulation. The line of the sternomastoid muscle is from the mastoid process to near the middle of the upper edge of the sternum. Thus the carotids are internal to the anterior edge of this muscle aboA-e, behind the angle of the jaw, and external to it below. The common carotid at its upper portion — it ends opposite the upper border of the thyroid cartilage — is just about at or close to the edge of the sternomastoid muscle. From the thyroid cartilage up are the internal and external carotids. The internal lies behind and to the outer side of the external. The internal gi\es off no branches until it reaches the skull, while the external is practically all branches. Sometimes the external and the internal carotids are covered b}' the anterior margin of the sternomastoid muscle. The branches of the external carotid are the superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, interyial maxillary, and temporal. The bifurcation. The superior thyroid artery is given of? in the interval between the hyoid bone and upper border of tlie thyroid cartilage. It gives a small infrahyoid branch to the thyrohyoid membrane, also a superior laryngeal branch to the inside of the larynx. This branch pierces the thyrohyoid membrane in company with the superior laryngeal nerve to reach the interior of the larynx. The sternoniastoid branch, to the muscle of that name, comes of?" at this point and crosses the common carotid artery. It is of some importance on this account because in ligating the common carotid artery above the omohyoid muscle it is likely to be cut and cause bleeding. Another branch of the superior thyroid artery is the cricothyroid. It is small, rests on the cricothyroid membrane, and is the first artery liable to be cut in an incision down the superior thyroid artery supplies the thyroid gland. The ascending pharyngeal is a long slender branch that comes from the under side of the main trunk. It lies on the superior and middle constrictors of the pharynx and goes clear to the skull, giving of? some meningeal branches. In ligating the external carotid care should be taken not to include this vessel in the ligature. It also gives branches to the soft palate, tonsil, recti capitis antici muscles, and tympanum. The lingual is given off just l)elow the greater horn of the hyoid bone, and passes forward beneath the hyoglossus muscle to supply the tongue and sublingual tissues. The hypoglossal nerve lies above the artery and on the hyoglossus muscle. The facial comes off just above the lingual artery or often in a common trunk with it. It passes upward and forward in a groove in the under surface of the submaxillary gland and passes over the edge of the jaw at the anterior border of the masseter muscle. The facial vein at this point is posterior to it. then along in the occipital groove beneath the origin of the sternomastoid muscle, the splenius, trachelomastoid, and digastric to make its appearance a Httle to the inner side of the middle of a line joining the mastoid process with the external occipital protuberance. The posterior auricular is given off just above the posterior belly of the digastric muscle and runs backward and upward on it, then through the parotid gland and up between the external auditory meatus and the mastoid process. In ligating the external carotid artery with a view of preventing bleeding in removing the Gasserian ganglion, it is endeavored to place the ligature just above the digastric muscle and posterior auricular artery in order to preserve the blood supply of the have already been considered. Veins. — The veins found in and near the superior carotid triangle are the anterior and interyial jugulars and their branches. A small portion of the commencement of the external jugular may also be in its extreme upper angle. The anterior jugular vein begins just above the hyoid bone from veins in the submaxillary and submental regions. It lies on the deep fascia and passes down the neck about i cm. from the median line, then just above the sternum it turns down and out under the sternomastoid muscle to empty into the external jugular or subclavian. At the point of turning it sends off a branch across the median line to the vein on the opposite side. Thus the blood-current can pass directly across the neck from one external jugular vein to the other. Sometimes there is another communication between the two anterior jugulars through a small branch crossing just above or belo\^ the hyoid bone. Instead of two anterior jugular veins there may be one; in this case it is likely to go down the median line of the neck and so be wounded in tracheotomy. It receives branches from the inferior thyroid veins and hence may bleed freely. It has no valves. The internal jugular vein lies to the outer side of and bulges somewhat anterior to the carotid arteries. It is formed by the junction of the inferior petrosal and lateral sinuses at the jugular foramen, and passes downward posterior to the internal carotid artery and soon reaches its outer side. It receives the facial, lino-ual, pharyngeal, superior and middle thyroid, and sometimes the occipital veins. A larp-e communicating branch from the external jugular unites either with the facial or wi'th the internal jugular, so that a wound of the external jugular may draw blood directly from the internal jugular. excised in operations for enlarged lymph-nodes or for infective thrombus. It is not ao large above the facial vein as below that point. It becomes so involved in enlargements of both tuberculous and carcinomatous lymph-nodes that it may be necessary to excise it along with the tumor. Its removal does not give rise to any serious svmptoms. It becomes thrombosed by the extension of a thrombus from the transverse (lateral) sinus, which in turn becomes affected by the extension of suppurative middle-ear disease through the medium of caries of the bones. When the internal jugular is thrombosed it is e\'idenced by swelling, redness, and tenderness along the anterior border of the sternomastoid muscle just behind the angle of the jaw. Bleeding from the veins in this region is particularly dangerous because the internal jugular itself is so large and having no \'alves, will bleed both from the side towards the heart and that towards the head. THE XECK. 137 regurgitates. The walls of the veins are thin and, if the fascias happen to be relaxed, fall readily together and thus are difificult to see, and are so adherent to the fascias as not to be readily seized. The surgery of this region requires extreme care and the avoidance of haste. Nerves. — Lying between the internal jugular vein and the internal and common carotid arteries is the pneicmogastric or te^ith nerve. It here gives ofi the supe7'ior laryngeal nerve, the internal branch of which enters the lar}'nx through the thyrohyoid membrane to endow the interior of the larynx with sensation; the external branch goes to supply the cricothyroid muscle. The pneumogastric ner\e is frequently seen in operations in this region. Its division has not been fatal. The hypoglossal Jierve winds around the occipital arterv' and goes forward on the hyoglossus muscle, which separates it from the lingual arter}-. The desceyidens hypoglos si filament leaves the parent nerve as it winds around the occipital artery. It lies on the carotid artery in the form of a loop formed by the addition of branches from the second and third cervdcal nerv-es. As it descends on the sheath of the vessels it gives a branch to the anterior belly of the omohyoid muscle. The loop sends branches to the sternohyoid, sternothyroid, and posterior belly of the omohyoid, and if the nerve is divided paralysis of these muscles will occur. The ner\e is to be pushed aside when ligating the artery and not included in the ligature. The superficial branches from the cervical plexus which come from the middle of the posterior edge of the sternomastoid muscle and ramify towards the median line, are nerves of sensation, and their division in operative work causes no serious symptoms, hence they are disregarded. The infra?naxilla7y branches of the seventh or fadal 7ierve supply the plsitysmai. ^ Lymphatics. — The lymphatics are composed of four sets, a superficial set along the anterior border of the sternomastoid muscle, a deep set accompanying the great vessels, a submaxillary set around and on the submaxillary gland, and a set, two or more in number, beneath the chin. The submaxillary gland itself not infreqviently enlarges and is difficult to distinguish from an enlarged lymphatic node. All these glands are at times subjected to operative procedures. Fig. 163 shows the submental, submaxillar}^ and superficial set of lymphatics enlarged, as well as the submaxillar}- gland itself. It is taken from a tuberculous subject. the tongue, mouth, and throat as well as from affections of the face and scalp. The INFERIOR CAROTID TRIAXGLE is limited posteriorly by the lower portion of the sternomastoid muscle, anteriorly by the median line of the neck, and superiorly by the anterior belly of the omohyoid muscle. In this triangle, or reached through it, are the lower portions of the common carotid artery and internal jugular vein, with the pneumogastric nerve between. Anteriorly are the larynx, trachea, thyroid gland, and sternohyoid and sternothyroid muscles. The carotid arter}-, jugular vein, and pneumogastric nerve lie partly in the triangle but rather under the edge of the sternomastoid muscle. Operations on the air-passages, lar}mgotomy and tracheotomy; on the thyroid gland, thyroidectomy; and ligation of the common carotid artery and removal of lymph-nodes are all done in this triangle. The superficial and deep lymphatics accompany the vessels; there are also some in Burns' s space above the sternum. In children, instead of the innominate arterv- ceasing at the sternoclavicular articulation, it sometimes rises above it and may be wounded in operation on the trachea. The thyroidea ima arter}-, if present, will lie on the trachea, coming up from the innominate or directlv from the aorta. The posterior cervical triangle has as its base the middle third of the clavicle ; its anterior side is the posterior edge of the sternomastoid muscle; its posterior side is the anterior edge of the trapezius; its apex is at the point of junction of these two muscles at the superior curved line of the occiput. It is customar}- to divide it into two triangles by the posterior belly of the omohyoid muscle. The upper triangle is large and is called the occipital triangle. The lower triangle is small and is called the subclavian triangle. This di\ision bv the posterior belly of the omohyoid muscle is not always satisfactory. The muscle runs upward and inward in a line from about the junction of the outer and middle thirds of the clavicle to a variable distance, up to 2.5 cm. (i in.), above the clavicle at the anterior edge of the sternomastoid muscle. The omoyhoid muscle has its lower attachment at the posterior edge of the suprascapular notch, which is below the level of the clavicle, and its posterior belly is sometimes concealed behind the clavicle and does not rise above it except at its inner extremity beneath the sternomastoid muscle. It is rare that any distinct triangle is formed, hence as far as the surface markings are concerned there is often no subclavian triangle. Therefore the posterior cervical triangle will be considered as a whole and not divided. It is covered by the skin, beneath which is the subcutaneous tissue, which at its lower portion contains the fibres of the platysma muscle. Its floor is composed from above downward of the splenhis, levator scapulce, scalenus posticus, scalenus niedius, and scalenus anticus muscles. The deep fascia of the neck spans the space and splits anteriorly to enclose the sternomastoid muscle and posteriorly to lymphatics. External Jugular Vein. — Lying on the deep fascia and beneath the superficial fascia and platysma is the external jugular vein. This begins below the ear and posterior to the ramus of the jaw, being formed by the union of the temporomaxillary and posterior auricular veins. It passes downward and slightly backward on the surface of the sternomastoid muscle to its posterior border, which it reaches at about the middle and follows down until about a centimetre above the cla^'icle; here it pierces the deep fascia and dips behind the clavicular origin of the sternomastoid muscle to empty into the subclavian. It has one pair of valves about 4 cm. above the clavicle, and another pair at its point of entrance into the subclavian. They do not entirely prevent a regurgitation of the blood. The external jugular vein receives the posterior external jugular vein, and the suprascapular and transverse cervical veins. The occipital may also enter into it. The veins of the neck are exceedingly irregular in their formation and may vary considerably. The external jugular is readily seen through the skin, it rnay be made more prominent by compressing it just above clavicle. In operations in this region of the neck in some cases it is necessary to divide this vein; in others one may be able to avoid it, at all events it should be recognized before the incision is made. Behind the angle of the jaw there is usually a branch communicating with the facial, lingual, or internal jugular vein, and just above its lower extremity it is enlarged, forming the part called the sinus. For these reasons, if the vein is cut low down near the clavicle or high up near the angle of the jaw bleeding is liable to be free. The valves are not competent to prevent the reflux of blood and it therefore drains the large internal jugular above and the subclavian below. The attachment of the vein to the deep fascia, as it pierces it abo\'e the clavicle, tends to keep its lumen open when the vein is divided and fa\'ors the entrance of air into the circulation. The size of the veins in the posterior triangle varies according to those in the anterior. If the anterior and external jugulars are large the posterior and internal jugulars are apt to be small. Arteries. — The arteries in the posterior cervical triangle are the subclavian, the transverse cervical, and sometimes the suprascapular when it runs above the clavicle instead of behind it. The line of the subcla\aan is from the sternoclavicular joint to the middle of the clavicle. It rises about 1.25 cm. ( y2 in.) above the clavicle. The clavicular origin of the sternomastoid muscle co^•ers the inner third of the clavicle so that the subclavian artery is only visible in the posterior cervical triangle from the outer edge of this muscle to the middle of the clavicle. Both the suprascapular and transverse cervical arteries are given ofi from the thyroid axis, which arises from the first portion of the subclavian just internal to the scalenus anticus muscle. Therefore at their origin they are both considerably above the level of the clavicle, but as they proceed outward they incline downward, and on leaving the outer edge of the sternomastoid muscle the suprascapular is usually behind the clavicle while the transverse cervical runs parallel to it and a short distance (\ cm.) above it, where it can be felt pulsating. The posterior belly of the omohyoid muscle can be represented by a line drawn from the anterior edge of the sternomastoid muscle opposite the cricoid cartilage, obliquely down and out to the junction of the middle and outer thirds of the clavicle. It is superficial to the transverse cervical artery and at its inner end is abo^■e it. These arteries and their accompanying veins will be encountered in operating in these regions for the removal of lymphatic nodes. Nerves. — The nerves in the posterior cer\'ical triangle are the spinal accesso7y, branches of the cervical plexus, and the brachial plexus. The position of the spinal accessory is important because it is frequently encountered in operations for the removal of enlarged Ivmphatic nodes. It enters the under surface of the sternomastoid muscle from 3 to 5 cm. below the tip of the mastoid process and emerges at the posterior edge about its middle or a little above. It is about at this point that the external jugular vein reaches the posterior border of the sternomastoid, and the cervical plexus, formed by the anterior divisions of the four upper cervical nerves, reaches the surface. From this point also the occipitalis minor runs upward along the posterior edge of the sternomastoid and the aitricularis tnagnus runs upward over the sternomastoid direct to the external ear. The szcperficial cervical runs directly across the muscle towards the median line and the descending branches — the sternal, clavicular, and acromial — pass down beneath the deep cervical fascia to perforate it just above the clavicle and become cutaneous. Care should be taken not to mistake them for the spinal accessory. Still deeper are the cords of the brachial plexus. These cords, sometimes two, at others three in number, are beneath the deep fascia and lie above the subclavian artery. They can be felt and in a thin person, if the head is turned to the opposite side, the prominence which they form under the skin can even be seen. Lymphatics. — The lymphatics of the posterior cendcal triangle are numerous and being often enlarged are frequently operated on. They lie along both the outer side of the internal jugular vein and under the posterior edge of the sternomastoid muscle, which they follow clear up to the base of the skull. They also follow the edge of the trapezius muscle and lie in the space between it and the sternomastoid: they extend downward under the clavicle and become continuous with the axillarylymphatics. The right and left lymphatic ducts empty into the venous system at the junction of the innominate and internal jugular veins. That on the left side is called the thoracic duct ; it begins as the receptaculum chyli on the body ol the second lumbar vertebra and is about 45 cm. (18 in. ) long. It drains all the left side of the body and the right as far up as and including the lower surface of the liver. The duct on the right side is called the right lymphatic duct; it is only i or 2 cm. in length and drains the right side of the head and neck, the right upper extremity, and the right side of the chest as far down as and including the upper surface of the liver. In this affection the head and the neck are so twisted that the face is turned toward the side opposite the contracted muscle and looks somewhat upward. It is usually caused by some affection of the sternomastoid muscle._ It is not always the only muscle involved, as the trapezius and others may likewise be affected. It is congenital or acquired. In the congenital cases it is caused by an injury to the Sternomastoid muscle, occurring during childbirth; a swelling or tumor may be present in the course of the muscle. In the acquired form the distortion may be more or less permanent and may be due to caries or other disease of the spine. In such cases it is evident that treatment is to be directed to the diseased spine rather than to the sternomastoid muscle, which will be found to be relaxed. Inflammation of the lymph-nodes of the neck may cause the patient to hold the head and neck in a distorted position. The wry-neck in this case will disappear as the cause subsides. Rheumatic affections of the neck are a common cause, and the sternomastoid muscle may then become contracted and require division. In rare instances a nervous affection causes a spasmodic torticollis. The persistent movements render this a very distressing affection, and to relieve it not only has the sternomastoid but also the trapezius been divided, and even the spinal accessory and occipital nerves have been excised. Division of the sternomastoid muscle should be done by open and not by subcutaneous incision. The sternal origin of the sternomastoid muscle is a sharp, distinct cord, but its clavicular origin is a broad, thin band extending outward a third of the length of the clavicle. An incision 2 or 3 cm. or more in length is made over the tendon and the bands are to be carefully isolated before being divided. The structure most important to avoid is the internal jugular vein. It lies close behind the sternal origin of the muscle and great care must be taken to avoid it. In one case in which it was accidentally wounded it was necessary to ligate it. As the Carotid and Subclavian Arteries and Branches. — Both these arteries are affected at times with aneurisms, necessitating their ligation. Ligation of the main trunks or their branches is also required in various operations on the head, as in removal of the Gasserian ganglion or maxilla, or excision of the tongue, thyroid gland, etc. The communication between the arteries on the two sides of the body is quite free, as also is that between the arteries above and those lower down. For this reason bleeding from the distal end of a cut artery will be almost as free as from its proximal end. The various branches of the external carotid anastomose across the median line of the body. The vertebrals communicate above through the basilar. The internal carotids communicate through the anterior cerebral and anterior communicating and with the basilar through the posterior communicating and posterior cerebral. Between the parts above and those below we have the superior thyroid anastomosing \\ith the inferior thyroid branch of the thyroid axis from the subclavian artery. The princeps cervicis, a branch of the occipital, anastomoses with the ascending cervical branch of the inferior thyroid, the trans\"erse cervical of the thyroid axis, and the profunda cervicis from the superior intercostal. These free communications enable the surgeon to Hgate to any extent without incurring the risk of gangrene. The h'ne of the carotid arteries is from a point midway between the mastoid process and the angle of the jaw to the sternoclavicular articulation. At the upper border of the thyroid cartilage the common carotid di\ides into the internal and external carotids; this is opposite the fifth cer\dcal vertebra. Common Carotid Artery. — This lies on the longus colli muscle and a small portion of the rectus capitis anticus, which separate the artery from the transverse processes of the vertebrae. The arter}^ can be compressed against the vertebrae and its pulsations stopped by pressing backward and slightly inward. It is superficial in the upper portion of its course but becomes deeper as it approaches the chest. The anterior tubercle of the transverse process of the sixth cervical vertebra is called Chassaignac s tubercle. It is about opposite the cricoid cartilage. It is one of the guides to the artery. The omohyoid muscle crosses the artery opposite the cricoid cartilage and just above it is the site of election for ligation. Ligatioji of the Common Carotid Artery. — In making the incision, which should be 5 or 6 cm. long, it should be laid along the anterior edge of the sternomastoid muscle with its middle opposite to or a little above the level of the cricoid cartilage. This incision may be a little anterior to the direct line of the artery' as given from midway between the angle of the jaw and mastoid process to the sternocla\-icular articulation. This is because the muscle bulges forward and overlaps and hides the artery. The artery is beneath its edge. On cutting through the superficial fascia and platysma the deep fascia is reached, some small veins perhaps being divided in so doing. The deep fascia is divided along the edge of the sternomastoid muscle, which is then pulled outward. Beneath it and running obliquely across the lower portion of the wound is the omohyoid muscle. It is recognized by the direction of its fibres, they being more or less transverse or oblique. Sometimes a small artery^, the sternomastoid branch of the superior thyroid, crosses the common carotid just above the omohyoid muscle. The artery is also crossed by veins. The lingual, superior, and middle thyroid veins all pass over it to enter the internal jugular. The middle thyroid vein may be above or just below^ the omohyoid muscle. These vessels all pass transversely across the artery and beneath the deep fascia. The artery Hes in a separate sheath to the inner side of the jugular vein. In the living body it is to be recognized by its pulsations. The vein being filled with blood may overlap the artery. Veins are readily emptied of their blood by pressure on the parts during the operation ; hence if the vein happens to be collapsed it mav not be recognized and is liable to be wounded. Therefore in examining for the arterv see that the pressure from the retractors or other sources does not obstruct the flow of blood through the jugular vein. Running down on the anterior surface of the artery is the descendens hypoglossi nerve. If seen it should be pushed aside. It supplies the sternohyoid, sternothyroid, and both bellies of the omohyoid muscles. The pneumogastric nerve lies posteriorly, between the artery and the vein. Care will be necessary to avoid including it in the ligature. The ligature is to be carried from the outer to the inner side, the needle being passed between the vein and the artery. Ligation of the Common Carotid Artery Belozv the Omohyoid Muscle. — The artery below the omohyoid muscle becomes deeper and less accessible. The sternomastoid muscle overlaps it and is less easily displaced. The sternohyoid and sternothyroid muscles likewise tend to encroach on it and have to be drawn inward. The internal jugular vein and carotid artery diverge as they descend, so that at the level of the sternoclavicular joint they are separated 2.5 cm. In this interval the first portion of the subclavian artery shows itself. The anterior jugular vein will probably be encountered along the edge of the sternomastoid muscle, and near the omohyoid muscle the artery will be crossed by the middle thyroid vein. Still lower it may be that the inferior thyroid will be encountered. Posterior to the carotid artery is the inferior thyroid artery, coming from the thyroid axis and going to the thyroid gland, and winding around from posteriorly to the inner side is the recurrent laryngeal nerve. The ligating needle is to be passed from without inward. Collateral Circidation After Ligation of the Common Carotid Artery. — When the common carotid has been tied the blood reaches the parts beyond from the branches of the carotid of the opposite side and from the subclavian artery of the same side. The branches of the external carotid anastomose across the median line. This is particularly the case with the superior thyroid and facial. The internal carotids communicate by means of the circle of Willis. From the subclavian the vertebral artery communicates by means of the basilar with the circle of Willis. The thyroid axis by its inferior thyroid branch communicates with the thyroid arteries of the opposite side. An ascending branch of the inferior thyroid as well as one from the transverse cervical, also from the thyroid axis, anastomose with branches of the princeps cervicis, which is a descending branch of the occipital. Finally the superior intercostal, which, like the vertebral and thyroid axis, is a branch of the first portion of the subclavian, through its profunda cervicis branch anastomoses with a deep descending- branch of the princeps cervicis (Fig. 172;. The Internal Carotid Artery. — The internal carotid lies posterior and to the outer side of the external. It gives off no branches in the neckf. Entering the skull through the carotid canal, in the apex of the petrous portion of the temporal bone and directly below and to the inner side of the Gasserian ganglion, it passes through the inner side of the cavernous si?ius and at the anterior clinoid processes it bends up to divide into the anterior and middle cerebrals. Before its division it gives off the posterior conwiunicating artery, the anterior choroid artery to supply the choroid plexus in the lateral ventricles, and the ophthalmic artery. The internal carotid artery in the neck is normally straight, but sometimes, particularly in elderly persoris, it is tortuous. This may then be mistaken for aneurism. It lies about 2 cm. posterior and a litde to the outer side of the tonsil. As the pharynx is the side of least resistance, when the vessel becomes tortuous it bulges into it, and on examination through the mouth a pulsating swelling can be distinctly seen in the pharynx ]ust posterior to the tonsil. The finger introduced can feel the pulsations, and pressui-e on the carodd in the neck below causes the pulsations to cease. Thus the character of the pulsating swelling can be recognized. This artery is rarely ligated, but if it is desired to do so it can readily be reached thfough an incision 6 or 7 cm. long behind the angle of the jaw. Aneurism or wounds may necessitate its ligation. At its commencement it is comparatively superficial, but as it ascends it gets quite deep, passing beneath the digastric and stylohyoid muscles. It should therefore be ligated below the angle of the jaw and not over 3 cm. from its origin at the upper border of the thyroid cartilage. It will be necessary to push the sternomastoid muscle posteriorly, as its anterior margin overlies the vessel. The interjial jugular vein is to its outer side and between the two and posterior is the pneumogash-ic nerve. The sympathetic nerve lies behind it but is separated by a layer of fascia and is not liable to be caught up in passing the aneurism needle. The lingual, facial, and laryngeal veins may be encountered and are apt to cause trouble. They will have to be held aside or ligated and divided. The ascending pharyngeal artery may lie close to the internal carotid and care should be taken not to include it in the ligature. The needle is to be passed from without inward. The External Carotid Artery. — Of recent years the external carotid artery has been ligated far more often than formerly, as it was customary to ligate the common carotid instead. The external carotid runs from the upper border of the thyroid cartilage to the neck of the mandible. It supplies the outside of the head, face, and neck. These parts are the seat of various operations for tumors, especially carcinoma of the mouth and tongue, diseased lymph-nodes, and other affections, and their blood supply. In extirpation of the Gasserian ganglion, hemorrhage has been such an annoying and dangerous factor that a preliminary ligation or compression (Crile) of the external carotid is frequently resorted to. This artery may also be ligated for wounds, resection of the upper jaw, hemorrhage from the tonsils, and angiomatous growths affecting the region which it supplies. Unlike some other arteries the external carotid sometimes seems to have no trunk, consisting almost entirely of branches. Therefore in ligating it one should not expect to find a big artery the size of the internal carotid, but often one only half as large. The branches of the external carotid artery are the superior thyroid, lingual, and facial, which proceed anteriorly toward the median line ; the occipital diwd posterior auricular, which supply the posterior parts ; the ascending pharyngeal, which comes off from its deep surface and ascends to the base of the skull ; and the temporal and internal maxillary arteries, which are terminal. It is ligated either near its commencement just above the superior thyroid artery or behind the angle of the jaw above the digastric muscle. superficial, being covered by the skin, superficial fascia, platysma, deep fascia, and overlying edge of the sternomastoid muscle. It is to be reached through an incision 5 cm. in length along the anterior edge of the sternomastoid muscle in a line from the sternoclavicular joint to midway between the angle of the jaw and the mastoid process. The middle of the incision is to be opposite the thyrohyoid membrane. The bifurcation of the common carotid artery is an important landmark. The superior thyroid artery is given off at the very commencement and sometimes even comes from the common carotid just below. The ascending pharvngeal is the next branch, about i cm. above the superior thyroid. It comes off from the deep surface of the artery ; almost opposite to it and in front is the lingual. It will thus be seen that the distance between the lingual and the superior thyroid, where the ligature is to be placed, is quite small. The superior thyroid is about opposite the upper border of the thyroid cartilage, while the lingual is opposite the hyoid bone. Beneath the artery is the superior laryngeal nerve, but it is not liable to be caught up by the needle in passing the ligature because it lies flat on the constrictors of the pharynx and is apt to be a little above the site of ligation. The veins are the only structures liable to cause trouble. They are superficial to the arteries. On account of their irregularity more may be encountered than is expected. The superior thyroid and lingual \-eins both cross the SLVtery to empty into the internal jugular. The facial vein is also liable to be met, as the facial artery frequently springs from a common trunk with the lingual. The communicating branch between the facial and external jugular vein is another one that should be anticipated. These veins, when it is possible, are to be hooked aside; otherwise they are to be ligated and cut. Great care should be taken not to mistake a vein for the artery. It might appear an easy matter to readily recognize the arterv and distinguish between it and the veins, but this is not always the case in the living subject. The veins may have some pulsation transmitted to them from the adjacent arteries and the artery may temporarily ha\e its pulsations stopped by pressure from the retractors. The living artery touched by the finger seems soft and does not give the hard, resisting impression felt in palpating the radial in feeling the pulse. The difference in thickness of the coats is also sometimes not apparent at a first glance. the internal carotid. Ligation of the Superior Thyroid Artery. — The superior thvroid is the first branch of the external carotid and is given off close down to the bifurcation or even from the common carotid itself just below. It lies quite superficial but of course beneath the deep fascia. At first it inclines upward and then makes a bend and goes downward^o the thyroid gland. It gi\'es off three comparatively small branches, the hyoid along the lower border of the hyoid bone, the sternomastoid to the muscle of that name, and the superior laryngeal to the interior of the larynx. The larger portion of the artery goes downward to supply the thyroid gland and muscles over it, therefore the artery is to be looked for at the upper edge of the thyroid cartilage, and not near the hyoid bone. The incision is the same as for ligating the external carotid low down, viz. , 5 cm. along the anterior edge of the sternomastoid muscle, its middle being opposite the upper edge of the thyroid cartilage. Veins from the thyroid gland — superior thyroid — will probably cover it. After the deep fascia has been opened, the external carotid is to be recognized at its origin from the common carotid and then the superior thyroid artery found and followed out from that point. The ligature is to be passed from above downward to avoid the superior laryngeal nerve. This nerve lies distinctly above the artery and is not liable to be injured if the thyroid artery is followed out from its origin at the external carotid. Tre\'es suggests ligating it between the sternomastoid and superior laryngeal branches, but it is more readily reached closer to the external carotid artery. Ligation of the Lingual Arte7y. — The lingual artery may be ligated for wounds, as a preliminary step to excision of the tongue, and to check the growth of or bleeding from malignant growths of the tongue, mouth, or lower jaw. The lingual artery springs from the external carotid opposite the hvoid bone about I cm. above the bifurcation of the common carotid. It is composed of three parts: the first, from its point of origin to the posterior edge of the hyoglossus its course, although it is sometimes desirable to ligate it in the first part of its course. Thftjirst part inclines upward and forward, above the greater horn of the hyoid bone, to the hyoglossus muscle, beneath which it passes in a direction somewhat parallel to the upper edge of the hyoid bone. It lies on the middle constrictor of the pharynx and superior larnygeal nerve and is covered by the skin, platysma, and fascia. It lies immediately below the stylohyoid and digastric muscles and is crossed by the hypoglossal nerve and some veins. This portion frequently gives off a hyoid branch which runs above the hyoid bone. It is often missing, in which case the parts are supplied by the hyoid branch of the superior thyroid. From either the end of the first part or the beginning of the second part, the dorsalis linguae branch arises. The second part of the lingual lies on the superior constrictor and geniohyoglossus muscles and is covered by the hyoglossus. It runs in a direction somewhat parallel to the upper edge of the hyoid bone and from 0.5 to i cm. above it. In this part of its course it is usually accompanied by one or two veins and the hypoglossal nerve is superficial to it, the hyoglossus muscle separating them. This is the part of the artery chosen for ligation. An incision is made, convex downward, running from below and to one side of the symphysis nearly down to the. hyoid bone and then sloping upward and back, stopping short of the line of the facial artery, which can be determined by the groove on the mandible just in front of the masseter muscle. The skin, superficial fascia, and platysma having been raised, the submaxillary gland is seen covered with a comparatively thin deep fascia. Some veins coming from the submental region may then be encountered. They may be ligated and divided. The submaxillary gland is next to be lifted from its bed and turned upward against the mandible, carrying with it the facial artery, which is adherent to its under surface. The tendon of the digastric will now be seen with the anterior and posterior bellies of the muscle forming an angle with its point toward the hyoid bone. These with the hypoglossal nerve form what has been called the triangle of Lesser. It is in this space that the artery is ligated. The floor of the space posteriorly is formed by the hyoglossus muscle, while anteriorly is seen the edge of the mylohyoid muscle. Through the thin fascia overlying the hyoglossus muscle can be seen the hypoglossal veins may be either on or under the muscle or both. The apex of the angle formed by the tendon of the digastric muscle is held down to the hyoid bone by a slip of fascia which is an expansion of the central tendon of the muscle and the tendon of the stylohyoid muscle. The distance at which the central tendon of the digastric is held away from the hyoid bone varies in different individuals and is an important fact to bear in mind in searching for the artery. If the tendon rests high above the hyoid bone the artery must be looked for low down, sometimes even under the tendon; if, on the contrary, the tendon is low^ down the artery may be o. 5 to i cm. higher up. The hypoglossal nerve lies on the muscle and nearer to the mandible than the artery. It there is a vein on the hyoglossus muscle it is apt to be below the nerve, that is, nearer the hyoid bone, and may lie directiy over the artery. The vein and the nerve are to be displaced up towards the jaw and an incision a centimetre long made through the hyoglossus muscle a short distance above the digastric tendon and parallel with the hyoid bone. This incision should not be deep, as the muscle is only 2 or 3 mm. (/s in.) thick. The edges of the incision being raised and displaced upward and downward, the artery will probably be seen running at right angles to the fibres of the muscle and parallel to the hyoid bone. If not seen at once it should be looked for below the incision, nearer to the hyoid bone. Care must be taken not to mistake the vein for the artery. That this is not an unlikely thing is shown by its occurring in the hands of a distinguished surgeon who had had exceptional experience in this same operation. The ligature needle may be passed from above downward to a\^oid including the hypoglossal nerve. Subclavian Artery. — The right subclavian artery runs from the sternoclavicular articulation in a curved line to the middle of the clavicle. It rises 1.25 cm. (}4 in., Walsham) above the clavicle. The innominate bifurcates opposite the right sternoclavicular joint. The left subclavian springs directly from the arch of the aorta, therefore it is longer than the right by 4 to 5 cm. , this being the length of the innominate. As the subclavian artery passes outward it is crossed by the scalenus anticus muscle, which divides it into three parts : the first part, extending to the inner side of the muscle, gives off three branches, the vetiebral, internal mammary, and thyroid axis; the second part, behind the muscle, gives off the superior intercostal; the third part has no branches. The first portion of the subclavian lies very deep and operations on il have been so unsuccessful that they have been practically abandoned. As it is frequently involved in aneurisms its relations are worth studying. In approaching the artery from the surface it is seen to be covered by the sternomastoid, the sternohyoid, and the sternothyroid muscles. The outer edge of the sternomastoid muscle corresponds with the outer edge of the scalenus anticus. The three first-named muscles having been raised, the artery is seen to be crossed by the internal jugular, the vertebral, and perhaps the anterior jugular veins. The anterior jugular above the clavicle dips beneath the inner edge of the sternomastoid muscle to pass outward and empty into the external jugular or subclavian. The pneumogastric nerve crosses the artery just to the inner side of the internal jugular vein. Below, the artery rests on the pleura, and on the right side the recurrent laryngeal nerve winds around it. Behind the artery are the pleura and lung, which rise somewhat higher in the neck than does the arterv. On the left side the phrenic nerve leaves the scalenus anticus muscle at the first rib, crosses the subclavian at its inner edge, and passes down on the pleura to cross the arch of the aorta. To the inner side of the artery runs the thoracic duct, which, as it reaches the upper portion of the artery, curves over it to cross the scalenus anticus muscle and empty into the junction of the internal jugular and subclavian veins. The trachea and oesophagus are likewise seen to the inner side of the artery. The thyroid axis comes of? its anterior surface, the vertebral from its posterior, and the internal mammary below. The second portion of the subclavian artery lies behind the anterior scalene muscle. In front of the anterior scalene is the subclavian vei7i. 'Wxq phrenic nerve runs on the muscle and at the first rib leaves it to continue down between the right innominate vein and pleura. Behind and below, the artery rests on the pleura and the middle scalene muscle is to its outer side. Thus it is seen that the artery passes through a chink formed by the anterior scalene muscle in front and the middle scalene behind. They both insert into the first rib. The posterior scalene is farther back and inserts into the second rib. Above the artery are all the cords of the brachial plexus. One branch of the subclavian, the superior intercostal artery, is given off near the inner edge of the anterior scalene muscle. The third portion of the subclavian runs from the outer edge of the anterior scalene muscle to the lower border of the first rib. This part of the artery is the most superficial. The only muscle covering it above is the thin sheet of the platysma, lower down the subclavius muscle and clavicle overlie it; but the operations on the vessel are done above these structures, hence they do not interfere. There are apt to be a number of veins in front of the artery. The external jugular and transverse cervical veins are certain to be present and perhaps the suprascapular and cephalic, which may enter above instead of below the clavicle. These veins may form a regular network in the posterior cervical triangle above the clavicle and prove very troublesome. Above is the brachial plexus and transverse cervical artery and still higher is seen the omohyoid muscle. The suprascapular artery is lower down and usually concealed just below the upper edge of the clavicle. The lowest cord of the brachial plexus, formed by the first dorsal and last cervical nerves, may be posterior to the artery. The nerve to the subcla\'ius muscle passes down in front of it. Ligation of the Third Portio7i of the Subclavian Artery. — The head is to be turned strongly to the opposite side and the shoulder depressed. This lowers the clavicle and raises the omohyoid muscle and therefore gives more room to work. The skin is to be drawn down and an incision 7.5 cm. long made on the clavicle. The drawing down of the skin is done to avoid wounding the external jugular vein. This vein is really fastened to the deep fascia, and the skin, platysma, and superficial fascia slide over it. On releasing the skin it slides up above the clavicle. The middle of the incision should be a little to the inside of the middle of the clavicle. The deep fascia is to be incised and the clavicular origin of the sternomastoid and traj^ezius muscles cut to the same extent as the superficial incision. The length of the adult male clavicle is about 15 cm. (6 in.). third or 5 cm. of the clavicle on its upper surface free from muscles. As the incision is 7.5 cm. long this necessitates the division of 2.5 cm. (i in. j of muscle, and as the middle of the incision is a little to the inner side of the middle of the clavicle this will make it necessary to divide more of the clavicular origin of the sternomastoid than of the trapezius. After the division of the deep fascia, fat and veins are encountered. The scalenus anticus muscle has the subclavian vein in front of it and the artery behind, therefore the vein must be attended to before a search is made for the edge of the scalene muscle. The veins to be encountered are the external jugular vein, which empties into the subcla\-ian in front of or to the outer side of the anterior scalene muscle, and its tributaries, the suprascapular and transverse cervical veins, as well as the anterior jugular and a communicating branch from the opposite side of the neck. The cephalic vein not infrequently sends a communicating branch over the clavicle to empty into the external jugular. The fat is to be picked away with forceps; the veins are to be held out of the way with a blunt hook or ligated and cut. The suprascapular artery may be seen close to or under the clavicle. The transverse cervical artery may perhaps be above the level of the wound. The omohyoid muscle may or may not be seen, as its distance from the clavicle is quite variable. The transverse cervical and suprascapular arteries are not to be cut, as they are needed for the collateral circulation. As was mentioned in speaking of the ligation of the external carotid artery, so also here it is not always easy to distinguish between arteries and veins. The veins being disposed of, the anterior scalene muscle is to be sought at the internal portion of the wound. It runs somewhat like the lower portion of the sternomastoid, the posterior edges of the two muscles coinciding. The phrenic nerve runs down first on the anterior surface and then on the inner surface of the scalenus anticus. The edge of the muscle being recognized, by following it down the finger feels the first rib. The tubercle on the first rib may not be readily felt because the muscle is inserted into it. The prevertebral fascia coming down the scalenus anticus muscle passes from it to the subclaviarL artery, forming its sheath; hence, as pointed out by George A. AVright, of Manchester {Anyials of Surgery, 1888, p. 362 1, the edge of the muscle may not readily be distinguished and the brachial plexus is a better guide. This is above the arter)' and the lower cord of the plexus hes direcdy alongside of the artery. It is closer to the artery above and to its outer side than the subclavian vein is below and to its inner side. The greatest care should be exercised in passing the aneurism needle around the artery. The vein is not so much in jeopardy as are the pleura and lowest cord of the brachial plexus, hence the needle is passed from above down between the nerve and the artery and brought out between the artery and vein. pleurisy, while including the nerve will cause severe pain, etc. Collateral Circidaiion after Ligatio7i of the Third Portion of the Subclavian Artery. — (i) Internal mammary with superior thoracic and long thoracic. (z) The posterior scapular branch of the suprascapular with the dorsalis branch of the subscapular. (■3) Acromial branches of suprascapular with acromial branch of acromial thoracic. (4) A number of small vessels derived from branches of the subclavian above with axillary branches of the main axHlary trunk below (Gray). Ligation of the Inferior Thyroid Artery. — The inferior thyroid arterv, unlike the superior, lies deep from the surface, and it is a far more difficult vessel to reach. It is a branch of the thyroid axis, the other branches being the transverse cervical and suprascapular. The thyroid axis comes from the first part of the subclavian just a litde to the inner side of the edge of the scalenus anticus muscle. The inferior thyroid artery ascends on the longus colli muscle, just to the inner side of the scalenus anticus and almost in front of the vertebral artery. When it reaches about the level of the seventh cervical vertebra it bends inward and behind the carotid artery to reach the lower posterior edge of the thyroid gland. The trans\-erse process of the sixth cer\-ical vertebra, called the carotid tubercle of Chassaig7iac. is above it. As it bends to go inward it gi\-es off the ascending cer\-ical arterv. In front of the artery are the internal jugular vein, common carotid artery, pneumo- gastric nerve, and the middle ganglion of the sympathetic. The recurrent laryngeal nerve usually passes upward behind the branches of the artery just before they enter the thyroid gland. The thoracic duct on the left side passes over the front of the artery low down. Operation. — An incision 7.5 cm. long is made along the anterior border of the sternomastoid muscle, extending upward from the clavicle. This will bring the upper extremity up to, or even above, the cricoid cartilage. The anterior jugular vein will have to be ligated and the muscle displaced outward. The common carotid artery should then be isolated and it, together with the pneumogastric nerve and internal jugular vein, drawn outward. The omohyoid muscle may appear at the upper edge of the incision. Feel for the carotid tubercle on the sixth transverse cervical process: the artery lies below the omohyoid muscle and cricoid cartilage and below the tubercle and beneath the sheath of the carotid. If the trunk of the sympathetic or its middle cervical ganglion, which lies on the artery, is encountered, it should be pushed to the inner side, the artery isolated outwardly and ligature applied. Do not go too far out or the scalenus anticus will be reached and the phrenic nerve may be injured, nor too far in, to avoid wounding the recurrent laryngeal. There are two fascias in the neck, the superficial and the deep. The superficial fascia has blended with it anteriorly the platysma muscle and the termination of the nerves, arteries, and veins. The main trunks of these structures lie for all practical purposes beneath the superficial fascia and adherent to the surface of the deep fascia. It is for this reason that in raising the superficial structures the larger trunks remain applied to the deep fascia and are thus less liable to be injured in the living and mutilated in the dead. In the superficial fascia and on the deep fascia are the superficial lymphatics. The superticial lymphatic nodes frequently suppurate. When they do the abscess so formed is prevented by the deep fascia from reaching the parts beneath, so the pus works its way out through the skin. As the superficial fascia is loose, if the abscess is slow in formation, it may extend for a considerable distance under the skin. Sebaceous cysts are common in the neck. As they are superficial to the deep fascia, which is not involved, they can be removed without fear of wounding any important structures. The veins do not overlie them; they are always superficial to the veins, therefore there is no danger of wounding the external jugular. The Deep Cervical Fascia. — The deep cervical fascia completely envelops the neck and sends its branches in between all its various structures. It is the fibrous tissue that both unites and separates all the different structures to and from each other. Where this fascia is abundant it forms a distinct layer, but where it is scant it is simply a small amount of connective tissue between two adjacent parts. To follow all the processes of the deep fascia through the neck between its innumerable structures is impossible — nor is it necessary. The main reason for studying the deep cervical fascia and its various parts is to understand the course pursued by abscesses and infections. This is best done by limiting oneself to the main superficial layer and some of the larger layers crossing from side to side. The principal layers of the deep cervical fascia are the superficial layer, which completely encircles and envelops the neck, the preverteb?'al layer, which passes from side to side in front of the spinal column, and the pretracheal layer, which passes from side to side in front of the trachea. The Stiperficial Layer. — The superficial layer of the deep fascia envelops the whole of the neck, with the exception of the skin, platysma, and superficial fascia. It is attached above to the occipital protuberance, the superior curved line of the occiput, the mastoid process, then blends with the capsule of the parotid gland, then passes to the angle of the jaw and along the body of the mandible to the symphvsis, whence it proceeds around the opposite side in the- same manner. Below it is attached to the sternum, upper edge of the clavicle, acromion process and spine of the scapula, thence across to the vertebral spines, to which and to the ligamentum nuchae it is attached up to the occipital protuberance. In the front of the neck it passes from the mandible down to be attached to the hyoid bone and thence downward to the sternum and clavicle. From the under side of this superficial layer processes of fascia come off and envelop the various structures of the neck. Every separate structure of the neck is covered by it and therefore separated from the adjacent parts by a more or less distinct laver of the fascia. In many places it is quite thin or almost imperceptible, amounting to but a few shreds of fibrous tissue, in other places it is more distinct, forming more or less marked capsules, as in the case of the thyroid and submaxillary glands, or fibrous layers, as in the case of those in front of the vertebrae and trachea. Posteriorly in the median line the superficial layer of the deep fascia sends a process which covers the under surface of the trapezius muscle. Anteriorly another process is given of? to cover the under surface of the sternomastoid muscle. The super- the deep fascia, being stuck to or blended with its upper surface. About 3 cm. Ti 14 in.) above the sternum the deep fascia splits into two layers, one to be attached to the anterior and the other to the posterior edge of the sternum in front of the sternohyoid and sternothyroid muscles. Between these two layers is the space of Burns ; it contains the lower ends of the anterior jugular veins with the branch that joins them, some fatty tissue and lymphatic nodes, and the sternal origin of the sternomastoid muscle. Sometimes a vein comes up from the surface of the chest below to open into the anterior jugular vein. The prevertebral layer passes from side to side directly on the bodies of the vertebrae. It covers the muscles attached to the spine, as the scalene, longus colli, rectus capitis anticus, and also the nerves, as those of the brachial plexus, coming from the spine. On reaching the carotid artery and jugular vein it helps to form their sheath. Its upper edge is attached to the base of the skull at the jugular foramen and carotid canal and thence across the basilar process to the opposite side. Interiorly it passes down on the surface of the bodies of the vertebrae into the posterior mediastinum. From the sheath of the vessels outward, beyond the posterior edge of the sternomastoid muscle, the prevertebral fascia covers the scalene muscles, the brachial plexus of nerves, and the subclavian artery. On reaching the clavicle the fascia is attached to its upper surface, blending with the superficial layer; it is then continued down over the subclavian muscle, forming its sheath, and ends as the costocoracoid membrane. The part over the subclavian artery and vein is continued over them and the brachial plexus and follows them into the axilla. This fascia forms the floor of the posterior cervical triangle; the roof is formed by the superficial layer of the deep fascia. It is between these layers that the suprascapular artery and veins run. The descending branches of the cervical plexus, the spinal accessory nerve, omohyoid muscle, and some fat and lymph-nodes are also found there. T\i^ pretracheal layer passes from side to side in front of the trachea. Laterally it too blends with the sheath of the vessels and is continued posteriorly behind the pharynx and oesophagus as the buccopharyngeal fascia. In front it blends in the median line with the superficial layer and is attached to the hyoid bone and cricoid cartilage. It splits to enclose and form a capsule for the thyroid gland, and below encloses in its meshes the inferior thyroid veins, and thence passes to the arch of the aorta to be continuous with the pericardium. Laterally it passes under the sternohyoid, omohyoid, and sternothyroid muscles to blend with the sheath of the vessels and the layer on the posterior surface of the sternomastoid muscle. This is its lateral limit. Underneath the sternomastoid muscle a loop of fascia proceeds downward from the omohyoid muscle to the first rib. This is derived from the sheath of the vessels beneath and the layer on the under surface of the sternomastoid superficially. The sheath of the vessels envelops the carotid artery, jugular vein, and pneumogastric nerve. Thin layers of fascia pass between these structures, separating one from the other. The sheath is formed by the union of the outer edge of the pretracheal fascia and the prevertebral fascia, with the fascia lining the under surface of the sternomastoid muscle. This sheath follows the vessels down into the chest and out into the axilla. The capsule of the parotid gland is formed by the splitting of the superficial layer of the deep cervical fascia as it passes from the mastoid process to the angle of the jaw. Its superficial portion is attached to the zygomatic process. Its deep portion passes from the styloid process to the angle of the jaw and is knowr( as the stylomandibular ligament. The capsule of the submaxillary gland is formed by a splitting of the superficial layer at the hyoid bone. It forms the covering of the gland and from the hyoid bone sends a process upward which lies on the digastric and mylohyoid muscles and follows the latter up to be attached along the mylohyoid ridge of the mandible. It proceeds with the submaxillary gland around the posterior edge of the mylohyoid muscle to cover its upper surface. The stylomandibular ligament alluded to above separates the parotid from the submaxillary gland. The capsule of the thyroid gland is not very thick and the gland is readily separated from it, as is also the case with the submaxillary gland. It is continued downward in front of the trachea as the pretracheal layer and laterally it blends with the sheath of the vessels. It follows the vessels downward into the chest and is continuous with the pericardium. The veins of the gland, which are at times very large, run beneath the capsule and bleed freely if wounded. The Buccopharyngeal Fascia. — Between the pharynx in front and the vertebral column behind is the retropharyngeal space. The fascia forming the posterior wall of this space is the prevertebral fascia already described. Forming its anterior wall is a thin layer of connective tissue called the buccopharyngeal fascia. It invests the superior constrictor of the pharynx and is continued forward on the buccinator muscle. It is continued downward behind the pharyn.x and oesophagus into the posterior mediastinum: laterally it blends with the sheath of the vessels and is continuous with the pretracheal fascia around the larynx, trachea, and thyroid gland (Fig. 179). course influenced by the various layers of the deep fascia. Pus in the Srcbmaxillary Region. — As the submaxillary space has the mylohyoid muscle as its floor, abscesses here show below the body of the mandible between it and the hyoid bone. Usually they point towards the skin. Infection of this space may occur from the teeth. Tillmans ("Surgery," vol. i, p. 434) saw a case in which in four days the pus caused death from infection of the mediastinum and pleura. This proceeded downward from a badly extracted tooth and thence under the deep fascia of the neck to the chest. The pus, filling the submaxillary space, as can also occur in Ludwig's angina, which is an infecti^'e inflammation of the submaxillary and sublingual regions, may follow the lingual and facial arteries to the sheath of the great vessels and down into the superior mediastinum. The infection in Ludwig's angina may pass around the posterior edge of the mylohyoid muscle and involve the structures around the Pus superficial to the deep fascia tends to perforate the skin and discharge externally. If it is slow in forming it may sink down and pass o\er the clavicle onto the upper portion of the chest. Pus in the suprasternal notch or space of Burns bulges anteriorly but may perforate posteriorly. The sternothyroid and sternohyoid muscles are attached to the posterior surface of the sternum; but the layer of fascia on their anterior surface is very thin, so that pus may either pass between the muscles or perforate them and so pass down in front of the pretracheal fascia close to the under surface of the sternum. It would then tend to show itself in the upper intercostal spaces, close to the sternum. Pus bettveen the pretracheal and superficial layers, as may occur from abscesses of the thyroid gland, tends to work its way downward rather than laterally. The pretracheal fascia at the sides blends with the sheath of the vessels and the fascia covering the posterior surface of the sternomastoid muscles. In this space lie the sternohyoid, sternothyroid, and omohyoid muscles. The pretracheal fascia is beneath them and the superficial layer of the deep fascia above. Pus can follow the posterior and arch of the aorta. Pus between the pretracheal and prevertebral layers cannot go further to one side than the sheath of the ^-essels. Therefore it follows the trachea and oesophagus down into the posterior mediastinum. This space, between these layers, is sometimes called the visceral space because it contains the oesophagus, trachea, and thvroid gland. Pus in this space can also perforate into the trachea, phar\-nx, oesophagus, or e\en extend laterally and involve the great vessels. thyroid muscles into the anterior part of the superior mediastinum. Pus posterior to the prevertebral fascia, as from caries of the Aertebrge. if high up may bulge into the pharvmx. forming a retrophar\-ngeal abscess. It may follow the scaleni muscles and brachial plexus down around the axillan,- arterv' into the axilla. In the neck it shows itself posterior to the carotid arteries and to the older edge of the sternomastoid muscles. Pus in the sheath of the great vessels, when originating from lymphatic nodes, may first raise the sternomastoid muscle and show itself along its anterior border; it may perforate the lumen of the vessels: it mav pass down with the vessels into the superior mediastinum: or it may bulge into the visceral space between the prevertebral and pretracheal lavers and follow the trachea and oesophagus down into the chest. Should it tend outwardly it mav break into the posterior cer\-ical triangle between the pre\"ertebral and superficial lavers and show itself above the cla\icle. Retropharyngeal Abscess. — Pus which tends to point into the pharynx may come from disease of the vertebrae, in which case it is posterior to the prevertebral fascia; or it may originate from the lymphatic nodes in the retropharyngeal space. When coming from caries of the vertebrae, it may point either in the pharynx or, pushing its way outward, pass behind the great vessels and show itself behind the outer edge of the sternomastoid muscle. I have seen it point in both these places in the same case. When originating in the retropharyngeal space it lies in front of the prevertebral fascia and behind the buccopharyngeal fascia. It either points forward into the pharynx or, going down, follows the posterior surface of the oesophagus into the posterior mediastinum. It may also perforate the oesophagus and enter its lumen. Pus in the Posterior Cervical Triangle. — If above the prevertebral layer this bulges directly forward and tends to open through the skin. Its progress downward is obstructed by the attachment of the superficial layer to the top of the clavicle as it blends with the prevertebral layer. If pus is beneath the prevertebral layer it may then follow the brachial plexus and subclavian artery down beneath the clavicle and appear in the axilla. The attachments of the costocoracoid membrane tend to direct the pus laterally under the pectoralis minor muscle into the axilla rather than to allow It to come forward on the anterior portion of the chest. - The lymphatics of the neck are both superficial and deep. The superficial nodes communicate freely with and end in the deep ones. For the sake of convenience we may divide them into a transverse set, embracing the snbnioital, submaxillary, superficial upper cervical (behind the angle of the jaw), posterior aiiricular, and occipital nodes; and tzvo longitudinal sets, one along the great vessels and another, a posterior set, in the posterior cervical triangle. The Transverse Lymphatics. — Tke szibmental nodes, also called the suprahyoid, lie beneath the chin and drain the region of the lower lip and chin and anterior part of the floor of the mouth. These will be enlarged in children with ulcerative skin affections of these regions. They may also be involved in carcinoma of the lower lip, especially if near the median line. That the submental nodes drain the tissues of the anterior portion of the mouth and probably the tongue itself is shown by Henry T. Butlin ("Surgery of Malignant Disease," p. 153), who states that the submental nodes are frequently affected in carcinoma of the tongue when its tip is involved. The submaxillary nodes are beneath the body of the mandible in the submaxillary triangle. They drain the lips, nose, floor of the mouth, gums, anterior portion of the tongue and side of the face. These are the nodes most frequently affected in carcinomatous affections of the lips and anterior portion of the tongue. Henry T. Butlin ("Surgery of Malignant Disease," p. 153) calls attention to the fact that in malignant disease of one side of the anterior portion of the tongue the lymphatics of the opposite side may also be involved, thus showing that the lymphatics of the two sides of the tongue freely anastomose. This is contrary to what exists as regards the arteries, which anastomose hardly at all across the median line. He also states that one or more of the lymphatic nodes is frequently imbedded in the substance of the submaxillary gland. Therefore the submaxillary gland is excised at the same time as the affected lymphatic nodes. The superficial upper cervical {subparotid) nodes are just below the parotid lymphatics and behind the angle of the jaw. They drain the region embraced by the masseter muscle as far back as the ear. They may be enlarged in affections of the skin and scalp abo\^e. Therefore in children with enlargement of these nodes the source of infection should be .sought in those regions. The posterior auricular nodes are behind the ear on the mastoid process and insertion of the sternomastoid muscle. In practice they are encountered as small ( I cm. ), round swellings behind the ear, which are usually quite tender to the touch. This is probably due to their being placed on a hard, bony base. When enlarged they are often the subject of operations. The superficial occipital nodes are just below the superior curved line of the occiput or a little lower down in the hollow below the occiput between the posterior edge of the sternomastoid and anterior edge of the trapezius muscles, resting on the splenius. These are the nodes that are enlarged in syphilis and are to be searched for in endeavoring to establish a diagnosis. Superficial and Deep Nodes. — The five sets of nodes just described, viz. , the submental, submaxillary, superficial upper cervical, posterior auricular, and superficial occipital, are all regarded as superficial nodes. As a matter of fact this di\ision of the lymphatic nodes into superficial and deep is not of practical value. The communication between the various nodes is quite free. Adjacent nodes communicate and the superficial nodes communicate with the deep ones below. the nodes will almost certainly be found to lie under the fascia along with the submaxillary gland. When the occipital nodes are enlarged they may not only be found in the space already described but also on the adjacent trapezius and sternomastoid muscle and even beneath the outer edge of the trapezius below the deep fascia. The anterior cervical lymphatics is the name given to those which tend to showin the anterior cervical triangle either beneath or in front of the sternomastoid muscle, between it and the median line. There are some nodes in the median line but they are almost all deep down in the neck above the sternum. The other nodes may be either superficial or deep, mosdy deep, along the edge of the sternomastoid muscle. They follow the sheath of the vessels. This is a very extensive chain of nodes. They may extend in all directions. As regards depth they may be on the deep fascia along the edge of the sternomastoid or following the external jugular vein. If deeper they follow the internal jugular vein and carotid artery directly up to the base of the skull, also behind and below the mastoid process and alongside of the transverse process of the atlas (first cervical vertebra). They extend under the sternomastoid posteriorly, deep in the suboccipital region. Should they be enlarged downward they will protrude behind the posterior edge of the sternomastoid into the posterior cervical triangle; if anteriorly they will follow it down into the space of Burns in front of the trachea and thence into the superior mediastinum. 'Y\\& posterior cervical nodes show behind the posterior edge of the sternomastoid, along the edge of the trapezius, and also above tne clavicle. They not infrequently fill the posterior cervical triangle and extend beneath the muscles on each side. Below they may be continuous with enlarged nodes in the axilla and extend anteriorly under the sternomastoid into the pretracheal region and mediastinum. They are frequently excised for both tuberculosis and carcinoma. In so doing particular care is to be taken on account of the trans\-ersalis colli and suprascapular arteries and veins, with which they may lie in contact, as well as the terminal portion of the external jugular. Postpharyngeal Nodes. — In the retropharyngeal space, toward the sides, between the buccopharyngeal fascia in front and the prevertebral fascia behind are located one or two nodes (see buccopharyngeal fascia, page 153, and retropharyngeal abscess, page 156). They seem to be the starting point, sometimes, of retropharyngeal abscess. They do not appear to get enlarged and project into the pharynx as tumors, as might be expected, so that they are not subjected to any surgical procedures. Operating for the Removal of Enlarged Cervical Nodes. — This operation may be one of the most serious in surgery. Sir Frederick Treves says : " An operation of this kind should not be undertaken unless the surgeon has perfect confidence in his practical knowledge of the anatomy of the neck. Scarcely an instance can be cited in the range of operati\-e surgery where a knowledge of the structure and of relations is more essential than in these excisions." The main difficulties encountered are in the avoidance of nerves and the control of hemorrhage. Air may enter the veins and cause death, and the thoracic duct may be wounded. The latter accident sometimes results fatally. The dilificulty of the operation will depend on the size and number of the nodes, their location, and the character of the inflammation or other changes they have undergone. In an early stage the nodes may be lying loose in the tissues and can be readily turned out when once exposed. Later they may be matted to the surrounding structures by inflammatory deposits and then their separation is a matter of difficulty and danger. The skin incisions may be either longitudinal or more or less transverse. The longitudinal incisions are usually along either the anterior or posterior border of the sternomastoid muscle, or the anterior edge of the trapezius. The transverse incision may be either opposite the hyoid bone — when it may be prolonged around the angle of the jaw and up to the mastoid process and over the suboccipital glands, or above the clavicle. As the skin and superficial structures are cut and the deep fascia opened, the superficial veins will be cut, hence the first anatomical fact to be borne in mind is the probable location of the veins. The most important of these is the external jugular. The internal jugular below the hyoid bone lies under the sternomastoid muscle and therefore is protected until the deeper dissection is begun. The external jugular runs about in a line from the angle of the jaw to the middle of the posterior edge of the sternomastoid muscle and thence downward to about the middle of the clavicle. Therefore an incision along the posterior edge of the sternomastoid will divide it at about the middle of the muscle, and the surgeon should be prepared to guard against an undue loss of blood when it is cut. Opening into the external jugular posteriorly between the middle of the sternomastoid muscle and the cla\'icle below are the posterior jugular, the transverse cervical, and the suprascapular veins. These latter open into the external jugular i or 2 cm. above the clavicle and are almost certain to be cut in operations in the supraclavicular fossa. An incision along the anterior edge of the sternomastoid low down will cut the anterior jugular vein a short distance above the sternum as it winds beneath the sternomastoid to empty into the external jugular. An incision along the anterior border of the sternomastoid from its middle up is bound to cause free hemorrhage. The external jugular behind the angle of the jaw communicates with the facial, which empties into the internal jugular; hence division of the external jugular at this point also drains the blood almost directly from the internal jugular. A carelessly deep incision may wound the internal jugular itself in the region posterior to the hyoid bone. The internal jugular is more superficial at this point than it is lower down. The temporomaxillary and posterior auricular veins will also be cut behind the ramus of the jaw. Not only are veins cut but also nerves. The middle of the posterior edge of the sternomastoid is the point of departure of several nerves. The superficial cervical runs directly transversely inward toward the thyroid cartilage. The auricularis magnus goes up to the lobe of the ear, and the occipitalis minor follows the posterior edge of the muscle up to the occiput. These three nerves are nerves of sensation and if they are divided only a certain amount of temporary anaesthesia will be produced over the parts they supply, hence their division is not a matter of much moment. The auricularis magnus is the largest of the three. The descending branches of the cervical plexus, which leave the posterior edge of the sternomastoid muscle immediately below the nerves just mentioned, proceed down under the deep fascia and will be seen only in a deeper dissection. The nerve which it is absolutely important to avoid is the spinal accessory. This enters the sternomastoid muscle on its under surface some little distance back of its anterior edge and 3 to 5 cm. below the mastoid process. It sends a branch to the muscle and leaves its posterior edge about its middle. It then passes downward and outward across the posterior cervical triangle under the deep fascia to enter the deep surface of the trapezius. If this nerve is divided, paralysis of the trapezius will certainly follow and as it is a motor nerve the shoulder of that side will drop considerably. This will be a permanent deformity because motor nerves do not seem to have their functions restored by time as so usually occurs when the nerves of sensation are divided. If the nodes to be removed are superficial ones there are no other structures to be feared and the operation will be an easy one. If they lie deeper, then the sheath of the sternomastoid muscle is to be divided and the muscle pulled outward. Just above the level of the cricoid cartilage a small artery, the sternomastoid branch of the superior thyroid, enters the muscle and it will be divided. As the sternomastoid is raised and pulled outward care must be taken to avoid wounding the spinal accessory nerve. As this nerve enters the muscle from 3 to 5 cm. below the mastoid process and some distance back from the edge of the muscle, if it is necessary to divide the muscle it is best done high up above the entrance of the nerve, or low down. By so doing the nerve supply (from the spinal accessory) and blood supply are not interfered with and the function of the muscle is not so much impaired as it would be if divided near the middle. The nodes not only possess their own capsule but also a covering from the connective tissue in which they lie. Therefore to remove them they must be detached and separated from it usually by blunt dissection. When these strands of fibrous tissue from the nodes to the surrounding parts are strong they have to be caught with forceps and cut. They are to be clamped, to avoid possible bleeding. When the angle of the jaw is reached the communicating branch between the facial and external jugular veins must be clamped and cut. The parotid gland is to be pulled upward and inward. The nodes may stick to the jugular vein and carotid artery. The vein is on the outside and is likely to be the first encountered. When distended it overlies the artery. If collapsed its presence may not be suspected. Feel for the pulsation of the carotid artery and avoid the structure just to its outer side. The jugular vein may be so mvolved in the mass as to necessitate its removal. In such a case remember that posteriorly between it and the carotid artery is the pneumogastric nerve. second and third vertebrae. Working still higher, the transverse process of the atlas or first cervical vertebra will be felt and seen below and to the inner side of the mastoid process. The connective tissue adherent to the nodes is attached to this transverse process and may have to be cut loose or scraped away. In doing so keep to the outer edge because the jugular vein and internal carotid artery lie on its anterior surface. Beneath the sternomastoid runs the anterior scalene muscle and on it, coming from the third, fourth, and fifth cervical nerves, is the phrenic nerve; so that it is not permitted to dig into and disturb the muscular mass to the outer side of the common carotid artery on which these nodes frequently lie. In operating in the submental regioji there is nothing to fear. The space between the two anterior bellies of the digastric muscles on the sides, the hyoid bone below, and down to the anterior surface of the mylohyoid muscle beneath, can be cleared out with impunity. Fig. 182. — Superficial and deep structures of the back of the neck, showing the suboccipital triangle, formed by the rectus capitis posticus major, obliquus superior and obliquus inferior: the suboccipital nerve emerges from just beneath the art. vertebralis. In the submaxillary jrgion remember that the fascia covering the submaxillary gland is thin, so that the gland will probably be exposed as soon as the superficial structures are raised. As the facial artery and vein cross the mandible just in front of the masseter muscle, the vein is posterior. The artery goes under the gland and is adherent to it, so that as the gland is raised the artery is brought up also. The facial and lingual veins usually empty into the internal jugular, but, as shown in Fig. 168, they may receive a communicating branch from the external jugular and the anterior jugular and continue down as the anterior jugular to empty into the external jugular low down in the neck, beneath the sternomastoid muscle. The hypoglossal nerve will be seen lying on the hyoglossus muscle, but it is readily avoided. The lingual artery is beneath the hyoglossus muscle anteriorly but both it and the facial must be looked for as one nears the posterior belly of the digastric. In the lozver cervical region, opposite the cricoid cartilage, the omohyoid muscle will be met. It will sometimes be necessary to divide it. The sternohyoid and sternothyroid muscles and the thyroid gland are to be drawn inward and the sternomastoid outward. One should always keep away from the thyroid gland, as the recurrent laryngeal nerve runs behind it and on the oesophagus near the trachea. Cutting it will probably, cause a permanent alteration in the voice. If the internal jugular vein has been removed, as it may be on one side, but not on both, beneath it one is liable to encounter the inferior thyroid artery below Chassaignac's tubercle on the sixth cervical vertebra, and further out the phrenic nerve on the scalenus anticus muscle, and lower down the transverse cervical and suprascapular arteries. The inferior thyroid veins usually run downward to empty into the innominate veins, but the lower portion of the anterior jugular vein and the middle thyroid veins will probably have to be ligated. The course of the various veins is quite irregular and large venous branches may be encountered at any place. 1)1 the posterior cervical triangle the spinal accessory nerve must be avoided as it runs down and back from the middle of the posterior edge of the sternomastoid muscle. The external jugular, posterior jugular, transverse cervical, and supra^ scapular veins may all require ligation. Beneath the deep fascia (superficial layer) are the descending or supraclavicular branches of the cervical plexus from the third and fourth cervical nerves. Care should be taken not to mistake them for the spinal accessory nerve. If the nerve has been divided it should be sutured together again at the completion of the operation. It is hardly necessary to caution against wounding the subclavian vein; it is in front of the anterior scalene muscle. The artery is behind the muscle. Do not dig under it. It rests on the pleura, a wound or tear of which may mean a septic pleurisy and death. In the angle formed by the junction of the internal jugular vein and subclavian on the left side is the thoracic duct. If wounded death may ensue through persistent leakage of lymph, but not infrequently healing eventually occurs. Wounding of the corresponding lymphatic duct on the right side is not considered so serious, the chyle being carried by the left duct. The cords of the brachial plexus run down and across the posterior cervical triangle above the subclavian artery, but a little care will enable one to avoid them. This is one of the regions of the body in which exact surgery is essential. The pharynx may be opened just below the hyoid bone, — stibkyoidean pharyngotoviy. The larynx may be opened in the median line, — thyrotomy. The cricothyroid membrane may be opened, — laryngotoiny. The trachea may be opened, — tracheotomy . Subhyoidean pharyngotomy is the entering of the pharynx by means of an incision below the hyoid bone. This is an extremely rare operation. It may be performed for the removal of foreign bodies or tumors. The incision may be made just below the hyoid bone and parallel to its border. This will divide the commencement of the anterior jugular vein, perhaps near the median line, perhaps toward the side. A transverse vein usually runs from one anterior jugular vein to the other across the median line at this point. Attached to the hyoid bone nearest to the median line is the sternohyoid muscle, then farther out the omohyoid, and still farther out the thyrohyoid. A small artery, the thyrohyoid, a branch of the superior thyroid, or sometimes of the lingual, will be divided. The thyrohyoid membrane being incised, access is obtained to the fatty tissue at the base of the epiglottis. If the incision is carried directly backward the epiglottis will be cut through at its base. If, however, it is kept close to the hyoid bone and made upward, the pharynx will be entered in front of the epiglottis and at the root of the tongue. If the incision is carried too far toward the sides the superior thyroid artery and e\'en the external carotid itself will be cut ; if carried too low down on the thyrohyoid membrane, then the superior laryngeal artery and nerve may both be wounded. Attention has already been called to the thvrohyoid branch. Thyrotomy is the division of the thyroid cartilage in the median line. The sternohyoid muscles almost touch in the median line. The division should be exactly in the median line. This will avoid wounding the anterior jugular veins. If not in the median line the incision will wound one of the vocal cords. Impairment of the voice certainly follows this operation; it is only performed for the removal of foreign bodies or growths. bodies, etc. There is not sufficient room between the cricoid and thyroid cartilages to do this operation properly until puberty has been reached and the larynx has enlarged. The cricoid cartilage is narrow in front but wide behind. Its upper edge rises rapidly as it passes backward, forming an upper crescentic border, the concavity being upward. The lower edge of the thyroid is concave downward. Thus the two edges make an oval opening in front which in children is too small to hold the tracheotomy tube. The nearness to the vocal cords is also a serious objection. Performing a laryngotomy is the easiest and quickest way to enter the air-passages. Both the thyroid and cricoid cartilages in the median line are practically subcutaneous. A longitudinal incision of the skin is usually advised, after which a transverse incision is employed for opening the cricothyroid membrane. The tube is to be shorter than the one ordinarily used for tracheotomy. The cricothyroid artery, running across the membrane, is usually too insignificant to cause any trouble ; it is nearer the thyroid cartilage, therefore the cut through the membrane should be close to the cricoid cartilage. Tracheotomy is the opening of the trachea. There are two varieties, the high and the low, according as the tube is inserted above or below the isthmus of the thyroid gland. When in the adult male the neck is in line with the axis of the body the lower border of the cricoid cartilage is about 4 cm. (i}4 in.) above the sternum. When the head is tilted far back the larynx is drawn upward and the lower border of the cricoid is 6 cm. (about 2^ in.) above the sternum. Hence in doing a tracheotomy the head is to be tilted far back. The total length of the trachea is 10 to 12 cm. (Morris, Hensman), beginning opposite the sixth cervical vertebra, — upper border in the child and lower in adults, — and ending opposite the fifth dorsal. About half of it is above and half below the top of the sternum. It is composed of 14 to 20 rings. In the adult the isthmus of the thyroid gland covers the second, third, and fourth rings. There are about eight rings above the sternum. A knowledge of the size of the trachea is necessary in order to select a tracheotomy tube of a size suitable to the particular case. The liability is to select too large a tube for young children, particularly infants. If this is done it may be very difftcult to introduce the tube, or the trachea may even be torn in the attempt. In operating, an incision 2.5 to 3 cm. long is to be made in the median line. This may cut the anterior jugular vein. If carried near to the sternum it will certainly divide the communicating branch between the anterior jugulars at that point. The top of the incision in a child will be over the cricoid cartilage, and as soon as the skin has been divided the finger is to be inserted and the cricoid cartilage felt and recognized. This will show how deep the trachea lies. In very young children the isthmus of the thyroid gland is liable to come up to the cricoid cartilage and the difficulty of displacing it far enough down to allow the tube to be inserted is such that it may be best to divide it. Therefore after the skin and deep fascia have been divided and the cricoid recognized by the finger the soft tissues covering the trachea immediately below the cricoid are grasped on each side with a haemostatic forceps and divided between them. These tissues may embrace the isthmus of the thyroid gland, the edges of the sternohyoid muscles, some veins, branches from the superior and inferior thyroids, and the fascia covering the gland and overlying the trachea. The trachea should be cleared before openiijg it. A sharp hook is inserted into the cricoid cartilage to steady it and an incision is made into the trachea from below upward. In making this incision the utmost care must be taken not to cut through the trachea and wound the oesophagus behind. The trachea of a child is not the hard resisting structure of the adult. It is a soft tender tube easily compressed and readilytorn by roughness, or punctured with a knife. Forceps do not readily hold in it and stitches through it are liable to tear out. Only the very tip of the point of the knife should be allowed to enter the tube. The utmost care must be taken to keep in the median line. This is to be accomplished by using the cricoid cartilage as a guide and by seeing that the position of the head is straight. Cutting to either side of the trachea will cause wounding of the common carotid arteries. Below the isthmus of the thyroid gland and running down on the trachea are the inferior thyroid veins. The superior and middle thyroid veins empty into the internal jugular vein, but the inferior thyroids go downward to empty into the innominate. These veins will be cut if a low tracheotomy is done. In the infant the innominate artery and sometimes, though rarely, the left carotid encroach on the suprasternal notch and may be wounded if the incision is carried too low. The left innominate vein as it crosses to the right side is liable, especially in very young children, to show quite plainly above the sternum and would certainly be cut if the deep incision was carried as far down as the top of the sternum. An anomalous artery, the thyroidea ima, a branch of the innominate, sometimes passes upward on the trachea. On account of the presence of all these vessels it is not allowable to do any cutting of the deep parts just aboA-e the sternum; they are simply to be depressed by blunt dissection and kept out of the way with retractors while the trachea is being incised. The cricoid cartilage is never to be incised. It is far more firm and resistant than the trachea and it serves to keep the trachea from collapsing. The proximity of the tracheotomy tube to the vocal cords would result in interference with their function. The method of Bose consists in dividing the fascia o\'erlying the trachea near the cricoid cartilage and pushing it down, carrying the isthmus and veins with it, and introducing the tube into the space so cleared. This is so difificult that it is better to divide the isthmus, as already described. OPERATIONS ON THE THYROID GLAND. The operations which are done on the thyroid gland are ligation of its arterial supply and complete or partial removal. These necessitate a knowledge particularly of its blood supply and structure. approach nearer to the cricoid cartilage. The lateral lobes lie under the sternohyoid and the sternothyroid muscles. They rise as high as the oblique line on the sides of the thyroid cartilages which marks the insertion of the sternothyroid muscles. The lobes descend to the level of the sixth ring of the trachea, which is two rings below the isthmus, about two centimetres above the sternum. The inferior constrictor of the pharynx is beneath the gland. The thyroid gland is covered by the pretracheal faseia and possesses a capsule of its own besides. This fascia envelops the gland and its capsule, and from its posterior surface is prolonged do^\•n on the trachea and envelopes the thyroid veins are in the pretracheal fascia. As the fascia leaves the gland at the sides one portion of it blends with and helps to form the sheath of the vessels. The other or deeper portion continues around the pharynx and oesophagus, forming the buccopharyngeal fascia. In freeing the gland and its capsule from the overlying pretracheal fascia care must be taken, as pointed out by James Berry (" Diseases of the Thyroid Gland," p. 269), not to be led by this fascia too far posteriorly and therefore wound, as has been done, the pharynx or trachea. The veins of the gland are more prominent and dangerous than the arteries. Thev ramifv beneath the capsule and as long as the capsule is not torn the bleeding is slight. The arteries of the thvroid gland are the superior and inferior thyroids and sometimes the thyroidea ima. The superior thyroid comes off the external carotid just above the bifurcation. It rises almost to the greater horn of the hyoid bone and then descends to the thyroid gland, which reaches to the level of the oblique line on the thyroid cartilage; it supplies the upper portion of the gland, particularly the anterior portion, but also sends a branch down the posterior surface. The vessels crossing the median line, contrary to what is often the case in the arteries of the lip and even the scalp, are very small. The superior thyroid is superficial and presents no special difficulty in ligation. The vein runs beneath it on its course to the internal jugular. The inferior thyroid artery, a branch of the thyroid axis, crosses behind the common carotid artery about the level of the seventh cervical vertebra, about on a line with the lower edge of the isthmus. It enters the gland from the side and not from below and ramifies on its posterior surface often as a single large trunk beneath the capsule gi\ing off branches to the parenchyma. Usually it is in front of the recurrent laryngeal ner\-e, but the middle cervical ganglion of the sympathetic lies on it. Sometimes the artery breaks into branches before it enters the gland. In such cases the recurrent laryngeal nerve may run between these branches and so be injured in removing the gland. The thyroidea iiiia artery when present enters the gland from below, coming up on the trachea usually from the innominate, in which case the innominate is apt to come off more to the left side and so bring the common carotid closer to the trachea than usual. It may also spring from the aorta or from the right carotid artery. The Veins. — There are three sets of veins, a superior, a middle, and an inferior thyroid, and, as Kocher has pointed out, an accessory thyroid between the middle and inferior ones. The veins ramify under the capsule and form a plexus, which in goitre is much enlarged and communicates freely across the median line at the upper and lower portions of the isthmus. The superior and iniddle thyroids pass outward to empty into the internal jugular. Still lower is the accessory i^iferior thyroid, which may empty into the internal jugular, as do the two above it, or it may pass down, as does the inferior thyroid vein, and empty into the innominate. The iiiferior thyroid vein does not follow the artery of the same name but with its fellow of the opposite side passes directly downward in front of the trachea to empty into the innominate vein. Its importance in operations on the trachea has already been alluded to in speaking of tracheotomy. In removing the gland the superior thyroid artery is found at the upper outer angle, the ligature should be placed sufficiently far out to include the branch to the posterior surface of the gland. In ligating the inferior thyroid arteries they are to be sought at the lower portion of the sides of the gland and are to be ligated either close to the gland or isolated by pulling the carotid artery outward, and tied as they make the bend at the edge of the anterior scalene muscle. Betu^een these two points lies the recurrent laryngeal nerve, usuallybehind the artery. Halsted advises that each separate branch be ligated as it enters the gland to a\-oid those supplying the parathyroids. The gland is covered by the omohyoid, sternohyoid, and sternothyroid muscles. If these cannot be drawn aside they should be divided near their upper ends in the same manner as already advised in the case of division of the sternomastoid in removing tuberculous nodes. The sternomastoid muscle will have to be drawn outward. THE PARATHYROID BODIES. The parathyroid bodies are usually four in number, but rarely there may be five or six. They are 6 to 7 mm. long, 3 to 4 mm. broad, and 1.5 to 2 mm. thick. The most constant site of the superior parathyroid is at the middle or junction of the upper and middle thirds of the posterior edge of the thyroid gland opposite the cricoid cartilage. The lower parathyroid is near the lower pole, but may be below it. They are small brownish bodies in the meshes of the loose connective tissue forming the outer capsule of the gland. Often they are quite distinct from the gland, but sometimes they lie in a cleft in the gland and thereby escape recognition. They possess a separate capsule. They are supplied by a separate artery, the parathyroid, a branch of the inferior thyroid. This latter usually gives off two parathyroid arteries, one to each body. Ginsburg {Univ. Penna. Med. Bulletin, Jan., 1908) has demonstrated a free anastomosis with the vessels of the opposite side. In many cases it is practically impossible to avoid wounding or removing the parathyroids in operations — Halsted has sucgested three means of avoiding their removal, viz. : (i) sHce off and leave the piece of thyroid gland supposed to contain the parathyroids; (2) ligate the superior and inferior thyroids, and a week or two later perform a subcapsular enucleation of the thyroid : (3) search for each parathyroid by following out the ramifications of the inferior thyroid artery — this is the best method of finding them in post-mortem examinations. The oesophagus runs from the level of the cricoid cartilage to the stomach. The cricoid is opposite the sixth cervical vertebra and the cardiac or oesophageal end of the stomach is opposite the lower border of the tenth thoracic vertebra. It is in the median line above, then curves slightly to the left until the root of the neck is reached, when it returns to the median line opposite the fifth thoracic vertebra. It is in front of the spine and the prevertebral fascia. The layer of fascia between Its anterior surface and the trachea is extremely thin. On each side are the common carotid arteries and the sheath of the vessels. The right recurrent laryngeal nerve winds around the commencement of the first portion of the subclavian, and passes the trachea and cesdphagus in which it ascends to the larynx. On the left side the recurrent laryngeal nerve winds around the arch of the aorta and ascends in the groove on the left side between the trachea and oesophagus. The left carotid artery is closer to the oesophagus than the right. The narrowest point of the lumen is at the cricoid cartilage. Its next narrow point is where it crosses the aorta and left bronchus. This is opposite the upper part of the second piece of the sternum or the upper border of the fifth thoracic vertebra. The third narrow portion is the cardiac opening into the stomach. Mouton (Tillaux, "Anat. Topograph.," p. 418) gives the diameter of the oesophagus at each of these three points as 14 mm. and the second rib, so that the foreign body is either at the root of the neck or just below the top of the sternum. If it passes the two upper constrictions it will probably pass the third, because the cardiac constriction is caused by the diaphragm, which relaxes and allows the body to enter the stomach. CEsophagotomy. — In operating, an incision is made along the anterior border of the left sternomastoid muscle from the sternoclavicular joint upward. The anterior jugular vein will be cut. After opening the deep fascia the sternomastoid is to be pulled outward. The omohyoid is to be drawn up and out and also the lower portion of the sternohyoid and perhaps the sternothyroid. The middle thyroid and perhaps an accessory thyroid vein are divided and the thyroid gland and trachea drawn inward. The trachea is to be identified by the sense of touch. The inferior thyroid artery is behind the sheath of the vessels and is so high that it is not likely to be injured. The recurrent laryngeal nerve must be looked for between the oesophagus and trachea, and avoided. In going deep down care must be taken not to injure the innomhiate vein, which comes well up towards the top of the sternum. CUT THROAT. The most frequent site of the incision in cases of cut throat is between the hyoid bone and thyroid cartilage. If above the hyoid bone, the incision will divide the mylohyoid, geniohyoid, geniohyoglossus, and hyoglossus muscles, and perhaps the dio-astric and stylohyoid. If it goes far back it may wound the submaxillary gland or duct, the facial or lingual arteries and veins, and the hypoglossal nerve. The commencement of the anterior jugular will certainly be divided and the external iuo-ular may also be wounded. The cut passes through the base of the tongue and the upper portion of the epiglottis. The tip of the epiglottis is sometimes entirely cut off. If in the thyrohyoid space, the incision passes a short distance above the \'ocal cords. The sternohvoid, omohyoid, and thyrohyoid muscles are divided. If prolonged backward the pharyn.x will be opened and perhaps the arytenoid cartilages wounded. The superior thyroid artery is likely to be cut. This is the vessel most often divided in suicidalw'ounds. The carotid arteries and internal jugular veins are deep and far back, lying under the edge of the sternomastoid muscle, and are rarely wounded. If these are cut, death usually rapidly ensues from hemorrhage. The superior laryngeal nerve may be injured as it pierces the thyrohyoid membrane. This nerve is sensory and its division is followed by anaesthesia of that half of the larynx to which it is distributed. This favors the entrance of food and liquids into the larynx and so may cause a fatal septic pneumonia. If through the thyroid cartilage the incision may wound the vocal cords. They lie just beneath the most prominent part of the thyroid cartilage and just below its median notch. If through the trachea, the incision may wound the thyroid gland, which reaches from about the sixth ring of the trachea to the oblique line on the thyroid cartilage. Bleeding from the wounded thyroid, if the gland is normal in size, is not likely to be excessive. Below the cricoid cartilage the oesophagus may be wounded, above it the pharynx may be opened. The two large sternomastoid muscles being put on the stretch tend to protect the large vessels beneath. Suppuration not infrequently accompanies these wounds of the neck in which the air and food passages are involved and may give rise to collections of pus which may travel between the fascias, as previouslv described. In treatment it is customary to cleanse the wounds and approximate the \'arious injured tissues as carefully as possible, and feed by a stomach tube. are either lateral or median in location. The lateral originate from the visceral (branchial) clefts, while the median are connected with the thyroglossal duct. The visceral clefts are depressions between the visceral arches. These arches, five in number, spring forward from each side of the embryo to form the neck region. Sometimes these arches are called branchial arches from the fact of their going to form the branchiae or gills of fashes and some of the other lower orders of animals. The first visceral arch divides into two parts, a maxillary part forming the upper jaw and a mandibular part forming the lower jaw. Defects in the maxillary arch producing harelip and cleft palate have already been described. Two of the ear bones, the incus and malleus, are also formed by the mandibular portion of the first visceral arch. The second visceral arch forms the stapes, the styloid process, the stylohyoid ligament, and the lesser horn of the hyoid bone. side of the neck. The first visceral clefit, called the hyomandibular cleft from its being between the hyoid bone and the mandible, forms the middle ear and Eustachian tubes from its inner portion and the external auditory meatus from its outer portion. The membrana tympani is the remains of the membrane which stretched across from one arch to the other. Cervical fistulae are formed by the persistence of a visceral cleft. As the first visceral cleft persists normally in the structures already named, it in itself does not form pathological fistuke, but congenital fistulae are sometimes encountered in the external ear which are the remains of the clefts between the tubercles of which the ear is formed. Cervical fistulae or sinuses may extend either completely through, from the surface to the pharynx, or may open internally or externally, or be closed at both ends, in which last case the contents accumulate and form a cervical cyst. down nearer the sternoclavicular articulation in front of the sternomastoid muscle and internally in the sinus pyriformis. The persistence of the third and fourth visceral clefts internally may produce pharyngeal diverticula, as already noted in discussing that region. visceral clefts it is evident that as they are lined with a secreting epithelium this must be destroyed or removed, or a recurrence will take place. In attempting to dissect them out one must be prepared to follow them through the structures of the neck to the pharynx inside. It is needless to say this may be a serious procedure. pharynx. These cysts and fistuke may be noted at birth or may develop later in life. Hydrocele of the Neck. — There are other cystic tumors of the neck which are congenital, being noticed at birth, and which grow to a large size. They are often wide-spread, extending not only between the tissues of the neck below the deep fascia but even into the axilla. Their walls are thin, consisting sometimes only of a layer of lining epithelium and the surrounding tissues. On this account it is impossible to dissect them out. The use of injections and setons has been abandoned as too dangerous. They rarely require treatment, as they tend to disappear spontaneously. Mr. J. Bland Sutton ascribes their origin first to congenitally dilated lymph-spaces; second ^as resembling the cervical air-sacs that exist in the howling monkeys; and third that possibly some of them may be related to a persistence of some portion of a branchial cleft. THE THORAX. 171 tongue through to the posterior surface of the hyoid bone and thence downward and forward to the isthmus of the thyroid gland. It begins to atrophy in the fifth week and is obliterated by the eighth. According to Sutton these cysts are never congenital but occur soon after birth or as late as the fourteenth year. They appear as rounded, cystic tumors just below the hyoid bone or over the thyroid cartilage. They either inflame and break of their own accord, discharging externally, or are opened by the surgeon and, contrary to what is the case in hydroceles of the neck, never tend to disappear, but a sinus remains. At times it almost heals, then the contents accumulate and a cyst forms, this again breaks and a sinus results as before. In attempting a cure by operation the sinus should be followed up behind the hyoid bone. In one case after two failures of attempted excision a cure was obtained by destroying the tract by introducing a small galvanocautery point. Unless every portion of the lining membrane be completely destroyed the cells will go on secreting and reproduce, in a short time, the original condition. Failure to cure these sinuses and cysts by excision often occurs, notwithstanding the exercise of the greatest care. The lower portion of the thyroglossal duct may persist in the form of the pyramid or third lobe of the thyroid gland, which arises from the isthmus or from the left side and ascends as far as the hyoid bone, to which it is attached. The thorax or chest is that portion of the trunk which lies between the neck and the abdomen. It is composed of a bony framework reinforced by soft parts, and contains the main organs of circulation and respiration. The oesophagus, an organ of the digestive tract, simply passes through it to the regions below. The chest-walls as well as the parts contained within them are affected by wounds and disease, especially the heart and its associated great vessels, and the lungs and pleurae. It is an example of bones performing a protecting function in addition to a supporting one. The functions of the heart and lungs are influenced by constitutional diseases in addition to their own local affections, hence they serve as guides to the general bodily condition, and the condition of the respiration and circulation is continually being examined for the purposes of diagnosis, prognosis, and treatment, even when the heart and lungs themselves are not involved. To make these examinations intelligently, necessitates a knowledge of the organs themselves and their relation to one another and the surrounding parts. This is essential for the physician even more than the surgeon. and covered by soft parts. The bones of the chest consist of the stermun, ribs, and thoracic vertebrcs. The clavicle and scapula compose the shoulder-girdle and belong to the upper extremity. The human skeleton is divided into an axial portion and an appendicular portion. The axial portion embraces the skull, the vertebral column, including the sacrum and coccyx, the hyoid bone, the sternum, and the ribs. The appendicular portion consists of the shoulder-girdles and upper extremities and the pelvic girdles and lower extremities. ment, and to deformities due to these causes. Shape of the Chest. — The chest is conical in shape, being small above and large below. In transverse section it is kidney-shaped, the hilus of the kidney being represented by the vertebrae. In the foetus the anteroposterior diameter is greater than the transverse, thus resembling the thorax in the lower animals. After birth and in infancy the two diameters are nearly equal, hence we have the rounded chest of the child. As growth and development progress the transverse diameter increases more than the anteroposterior, so that at about the second year the chest has become oval ^nd in adults the transverse diameter is one-fourth greater than is the anteroposterior. sternum. If the sternum projects markedly it constitutes what is known as pigeon breast^ the chest in such a condition being longer from before backward than from side to side. In this disease also there may be a depression on each side of the sternum, junction of the ribs and cartilages are enlarged, this latter constituting what is known as beading of the ribs. These beads are felt as rounded enlargements at the sternal extremities of the ribs and form a line parallel to the sternum above and sloping outward below. This line of beads has been called the " rachitic rosary." From the level of the ensiform cartilage a groove passes out toward the sides ; this has been called '■' Harrisoyi' s groove" (see Fig. 193). Sometimes the lower end of the sternum is pressed inward, forming a deep funnel-shaped depression constituting the deformity known as ''funnel chest" or the '' Trichterbrnst" of the Germans. This condition of the chest, with the exception of the beading, is also produced in children by obstruction to the breathing from enlargement of the tonsils, from the presence of adenoid growths in the pharynx, and from hypertrophy of the turbinate bones, all of which interfere particularly with nasal respiration. Diseases of the lungs and pleurae alter the shape of the chest. In emphysema and when distended by plural effusions, the thorax becomes more rounded in shape, forming what is called the ' ' barrel-shaped chest. ' ' In phthisis the wasting of the tissues and contraction of the lungs causes the chest to collapse. The ribs slope more sharply downward and the chest becomes longer and flatter, the anteroposterior diameter being diminished. The angle made by the lower ribs as they ascend to the sternum is called the costal angle ; this becomes decreased in phthisis. This form of chest is known as the ' 'phthisical chest. ' ' ward and its anteroposterior diameter is increased. The abdominal contents are crowded up into the chest and push the sternum and lower ribs forward. Associated with this deformity is oftentimes a lateral deviation of the parts above the site of the disease. In scoliosis, or lateral curvature of the spine, the distortion is une\'en, being a compression of the thorax from above downward and a twisting around a vertical axis. The deformity is frequently so severe as to cause the lower ribs to rest on the iliac crests. It is in order tO' detect these diseases in their early stages that a knowledge of the shape of the normal chest is so essential. THE STERNUM. The sternum consists of three pieces: the mamibrium or presternum, gladiolus or mesosternum, and xiphoid cartilage or metasterniwi. It is developed in two lateral halves. Should these fail to unite an opening is left in the bone through which the pulsations of the heart have been seen and felt. The junction of the first and second pieces of the sternum is opposite the second rib. The se\enth is the last rib to articulate with the sternum directly. The first and second pieces of the sternum are connected by a joint which persists to advanced age. The projection caused by this joint is called the angulus sterni or angle of Liidnng. Fractures pass either through this joint, opposite the second rib, or through the bone just below it. They are produced by both direct and indirect force. Usually the upper fragment is beneath the lower one. It is however more true to state that the lower fragment is displaced anteriorly. Any marked posterior displacement of the upper fragment would tend to press on the trachea and interfere with breathing; the trachea iDifurcates opposite the joint. As the pleura; and lungs of the two sides almost or quite touch behind the second piece of the sternum, they may be wounded and emphysema may occur. The heart also maybe wounded. Suppuration has followed these injuries, in which case it will be necessary to trephine the sternum to give exit to the pus. The necessity of avoiding wounding of the pleurae in such a procedure is evident, as it would be followed by collapse of the lung and empyema. THE RIBS AND COSTAL CARTILAGES. The ribs are frequently fractured, sometimes they become affected with caries, and in operating the chest is frequently opened between them or portions of them are excised. They are both elastic and movable, and difficult to break; hence fracture is almost always due to direct violence, and this violence may be so great as sometimes to cause death. Normally there are twelve ribs on each side, but sometimes there is an extra cervical or lumbar rib. These are both rare, the latter the more so. The seven upper ribs are called tr^ie ribs because they articulate with the sternum. The remaining five are called yfl/.y^ ribs, the eleventh and twelfth \i€\\\^ floating ribs. The eighth, ninth, and tenth ribs each articulate by their cartilages with the rib above. The tenth forms the lower margin of the thorax. The eleventh and twelfth ribs are attached only by their posterior extremities, their anterior portion being imbedded in the soft parts; hence they are called floating ribs. The ribs slope downward and forward. This obliquity increases until the ninth rib, after which it decreases. The first rib in front corresponds to the fourth behind, the second, third, fourth, fifth, sixth, and seventh in front correspond each to the fourth rib lower behind. The first rib is the nearest horizontal in regard to its surface and, being well protected by the clavicle, is rarely broken. The intercostal spaces are broader in front than behind and broader above than below. The third is the largest. as far back as the angle, from which point it occupies the middle of the space. The extent of the intercostal spaces is considerably influenced by position — flexion of the body brings the ribs together, extension and bending to the opposite side separates them. This point is of importance in reference to the operations of paracentesis and empyema. The first costal cartilage unites directly with the sternum, there being no joip.t present. The second and sometimes the third cartilage is joined to the sternum by a ligament with a synovial joint above and below it. The other costal cartilages are abscesses in pyaemic infections. Cervical ribs spring from the body and transverse process of the seventh cervical vertebra. They may be long enough to reach to the sternum, but usually are much shorter. One case of this affection was seen by the writer in a man twenty-seven years of age. There was an abnormal fulness above the scapula posteriorly, and above the clavicle anteriorly, just to the inner side of the external jugular vein, a distinct bony process could be felt. This did not move with the scapula or clavicle but did move somewhat with respiration. A skiagraph showed it to be attached to the spine. The patient was seen again five years later, when the same condition of affairs existed, with the exception that movement on respiration was not so marked. A knowledge of the possible presence of a cervical rib is important in diagnosis, otherwise it may be thought to be a bony or malignant new growth and treatment advised accordingly. The subclavian artery may pass over the cervical rib above and may have its circulation seriously interfered with. Fracture of the Ribs. — The ribs are almost always broken by direct violence; fractures from indirect force, as from coughing, sneezing, and other forms of muscular exertion, are rare. Fracture from compression of the chest is also rare. The site of the fracture is most frequently on the anterior portion of the chest and not the sides or back. The fourth, fifth, sixth, and seventh ribs are most often broken. The first rib is well protected from direct blows by the clavicle. Lane, however, has shown that it can be broken by pressure of the clavicle when the shoulder is depressed. The eleventh and twelfth, being floating ribs, are rarely broken. The twelfth rib is the least frequently so. In one case we saw the eighth, ninth, tenth, eleventh, and twelfth all broken by the passage of a wheel. The soft parts attached to the fragments prevent much displacement, but there is alwavs some, due to the respiratory movements. Hence callus is always present and it may be so abundant as to join adjacent ribs (see Fig. 199)- As already stated, death frequently follows fracture of the ribs and is due to wounding of the chest contents. Rarely the intercostal arteries may be wounded and produce haemothorax. Wounding of the lung is frequent. Emphysema of the surface of the body may ensue, but is not dangerous. Pneumothorax, which may be accompanied by infiltration of air into the lung tissue, is more dangerous, favoring collapse of the lung. The object of treatment is to keep the chest-walls from moving. This is accomplished by strapping the chest with adhesive plaster, which is usually laid on almost in the direction of the ribs ; but as the chest moves with respiration, the ribs rising, and as they slope downward and forward, I have preferred to lay the straps on from in front downward and backward, this tends to prevent the ribs from rising in inspiration. The thoracic or dorsal vertebrae are twelve in number and are so articulated with one another as to form a single, regular curve with its concavity forwards and convexity backward. Any sudden change in the direction of the curve is an evidence of disease; this is seen in the angular curvature of Pott's disease or caries of the spine. The ribs are connected with the vertebrae by the articulation of the head of the rib with the body of the vertebra, and the tubercle of the rib with the tratisverse process. The trans\'erse process is connected with the body by the pedicle and with the spinous process by the lamina. The spinal cord is exposed in operations by removal of the spinous process and laminae, hence the name laminectomy. The spinous processes are the guides which indicate the position and condition of the vertebrae. Their tips are not covered by muscles but lie close beneath the skin and are readily felt and any abnormality detected. In the normal body the grooves on each side of the spinous processes are filled up with muscle, but in certain diseases, as in infantile paralysis and lateral curvature, they become atrophied and the spine becomes twisted, hence on the convex side of the abnormal lateral curve, to the outer side of the spines, the projection formed by the transverse processes and tubercles of the ribs can be both seen and felt. The external curve formed by the tips of the spinous processes of the thoracic region in the normal person is not so great as is the curv^e formed by the anterior portion of the bodies of the thoracic vertebrae. This is because the spinous processes at the upper and lower portions of the chest project out almost at right angles to the long axis of the body, while those of the middle portion slope downward. Hence the tips of the spinous processes of the seventh cervical, first dorsal, and twelfth dorsal vertebrae are opposite the bodies of the same vertebrae, while the others are opposite the bodies of the vertebrae next below. (The spine will be considered more at length in the section devoted to the Back. ) The exter^ial intercostal muscles run downward and forward. They begin at the tubercles of the ribs posteriorly and end at the costal cartilages anteriorly. They are continued forward to the sternum by the anterior intercostal membrane, formed by the fusing of the outer and middle intercostal fascias. The internal intercostal muscles go downward and backward. They begin at the sternum and end at the angles of the ribs. They are continued to the spine by the posterior intercostal membrane, formed by the fusing of the middle and internal intercostal fascias. The intercostal arteries come from both anteriorly and posteriorly. The ayiterior intercostals come from the internal mammary for the upper five or six spaces and from the musculophrenic artery for the remainder. They arise either as a single trunk or as separate superior and inferior branches. At first they are between the pleura and internal intercostal muscle, but they soon perforate that muscle and run between it and the external intercostal, the superior branch running along the lower edge of the rib and the inferior branch running along the upper edge of the rib below. The aortic or posterior intercostal arises as a single trunk which passes between the external intercostal muscle and the pleura. Arriving opposite the angle of the ribs it divides into superior and inferior branches which unite with those from the internal mammary ( atieria mamniaria iyiternci). From the vertebrae out to the angle of the ribs the intercostal artery lies about midway between the ribs, hence it is liable to be wounded in paracentesis if the puncture is made too far back. It is for this reason that operations for draining the pleurae are performed anterior to the costal angles. The superior intercostal branches are larger than the inferior ones. They run under the lower edge of the rib above the space and are therefore protected from injury, particularly stab-wounds. In opening the chest for empyema it is best to go about midway in the intercosal space and not too close to the lower edge of the rib on account of the liability of wounding the superior intercostal. The inferior branch is usually quite small and causes no serious hemorrhage. Intercostal bleeding may cause a harmothorax if the wound is small. It may be controlled, if the vessel is cut in performing the operation of paracentesis for empyema, by clamping with haemostatic forceps. If these are allowed to remain on a few minutes the bleeding often does not recur on their removal. If desired a ligature can be applied. If it is undesirable to rely on the clamp or ligature then the wound may be firmly packed with gauze or a piece of gauze may be depressed through the wound into the pleural cavity and then stuffed with more gauze, after which the tampon so formed is pulled firmly outward against the bleedinsr tissues. Covering the chest anteriorly are the pectoralis major and pectoralis minor muscles. The serratus anterior imagnus) winds around its side and posteriorly, above is the trapezius and below the latissimus dorsi. Beneath them are the erector spines {sacrospiyialis) inuscles on each side of the spinous processes. aponeurosis of the external oblique muscle and sheath of the rectus muscle. It inserts into the outer lip of the bicipital groove. It is to be noted m regard to this muscle that it is attached onlv to the inner half of the clavicle and that the clavicular breast for carcinoma one separates the muscle by passing through this cleft and detaching the part below. It forms the anterior fold of the axilla and by following this fold to the chest-wall it leads to the fifth rib, as it is at that rib that the muscle leaves the chest-wall. The serratus anterior Cmagnus) muscle (Fig. 202) passes from the side of the chest to the vertebral or posterior border of the scapula, arising by nine or ten digitations from the eight or nine upper ribs, the second having two. The slip arising from the sixth rib is the one most prominently seen on raising the arm away from the side, it passes the farthest forward. The slips into the fifth, seventh, and eighth ribs may also be seen. This muscle passes across the axilla from in front backward, respiratory nerve of Bell. It is supplied by the posterior thoracic nerve from the cervicals. This nerve is also called the long external The internal respiratory nerve is the phrenic, which comes from the third, fourth, and fifth cervical nerves. One of the main functions of this muscle is to keep the scapula applied to the chest and to aid in rotating it in elevation of the arm. When it is paralyzed the arm cannot be raised beyond a right angle and the scapula projects, particularly at its lower angle and posterior edge. This condition is called ' ' ivinged scapula. The trapezius muscle (Fig. 203) has the shape of a triangle, its apex being out on the acromion process and its base in the median line. It arises posteriorly from the inner third of the superior curved line of the occiput, the occipital protuberance, ligamentum nuchse, and the spines of the se\enth cervical and all the thoracic vertebrae. It inserts into the outer third of the clavicle and the acromion and spinous processes of the scapula. It aids in rotating the scapula and elevating the shoulder; its paralysis is followed by marked dropping of the shoulder. It is supplied by the spinal accessory nerve, \\\\\c\\ is sometimes injured in operations for tumors involving the posterior cer\ical triangle. The latissimus dorsi muscle arises from the spinous processes of the lower six thoracic vertebrae, from the posterior layer of the lumbar fascia, the outer lip of the posterior third of the iliac crest and by digitations from the lower three or four ribs. Sometimes it is attached to the angle of the scapula. It unites with the tendon of the teres major muscle to be inserted into the bottom of the bicipital groove and extends somewhat higher than the tendon of the pectoralis major. A bursa, which may become inflamed, sometimes lies between the muscle and the inferior angle of the scapula. The latissimus dorsi and teres major muscles form the posterior axillary fold. The erector spinae (sacrospinalis) muscle fills up the hollows on each side of the spinous processes. As the various muscular bundles are inserted into the vertebrae by innumerable small tendinous slips, in exposing the vertebrae in performing laminectomy it is necessary to cut them with a knife or scissors. One should not attempt to separate them by blunt dissection. These muscles become atrophied in cases in which the spine becomes distorted. On looking at the chest one should note whether or not it appears normal. It may show the rounded form of emphysema or the flat form of phthisis. One side may be larger than the other, suggesting pleural effusion. The intercostal spaces may be obliterated, indicating the same condition. This may be local instead of over the whole chest. Note whether Harrison's groove, funnel and pigeon breast, or beading of the ribs, already described, are present. Aneurism affecting the great vessels may cause a bulging in the upper anterior portion, and cardiac disease may produce marked changes in the ape.x beat. This may be displaced to the right side by pleural effusion. The clavicle belongs to the shoulder-girdle and hence will be described with the upper e.xtremity. Both it and the sternum are subcutaneous and can readily be felt beneath the skin. The point of junction of the first and second pieces of the sternum is opposite the second costal cartilage. It forms a distinct prominence, which is readily felt and is a most valuable landmark. It is called the aiigulus sterni or angle of Louis. There is usually a palpable depression at the junction of the second piece of the sternum and xiphoid cartilage. The tip of the xiphoid or ensiform cartilage can be felt about 4 cm. below the joint between it and the second piece of the sternum. The top of the sternum is opposite the lower edge of the second thoracic vertebra. The angulus sterni is opposite the fifth vertebra, the lower end of the second piece of the sternum is opposite the tenth, and the tip of the ensiform cartilage is opposite the eleventh thoracic vertebra. Abo\-e its upper depression or epigastric fossa, sometimes called the scrobiciilus cordis. With the upper end of the sternum articulate the clavicles. The sternoclavicular ioint possesses an interarticular cartilage between the clavicle and the sternum. This separates them sufficiently to allow the formation of a distinct depression, which can readily be felt. From the sternum to the acromion process the clavicle is subcutaneous. Below the inner end of the clavicle the first rib can be often seen and felt. At the middle of the clavicle it is so deep from the surface as not to be accessible and here the second rib is the one which shows just below the clavicle. In children the point of junction of the cartilages and ribs can often be distinguished; this is particularly so in cases of rachitis. The line of junction between the body of the sternum and the ensiform cartilage can be distinguished, and to each side of it is felt the cartilage of the seventh rib the last that articulates with the sternum. The tenth rib is the lowest which is attached anteriorly, the eleventh and twelfth being shorter and floating ribs. The intercostal spaces are wider anteriorly than posteriorly and the third is the widest. The nipple is usually in the fourth interspace or on the lower border of the fourth rib and on a line a little to the outer side of the middle of the clavicle. In women its position is variable, owing to the breasts being pendulous. The mammary gland reaches from the third to the seventh rib. As the pectoralis major muscle does not arise lower than the sixth rib it is seen that the mammary gland projects beyond it, an important fact to be remembered in operations for removal of the breast. Immediately to the outer side of the upper edge of the pectoralis major, beginning at the middle of the clavicle and below it, is a hollow. This is the interval between the pectoralis major and deltoid muscles. At its upper end it is equal in width to one- sixth the length of the clavicle, because the deltoid is attached only to the outer third of the clavicle. Immediately beneath the edge of the deltoid muscle and about 2.5 cm. below the clavicle is the coracoid pTocess. On abducting the arm the scapula is rotated and the serratus anterior muscle is put on the stretch; this makes its four lower serrations visible. The serration attached to the fifth rib is the highest, the sixth is the most prominent and extends farthest forward, while below are the last two attached to the seventh and eighth ribs. The operation of paracentesis, or tapping for pleural effusion, is most often done in the sixth interspace in the midaxillary line. This will be about on a level with the nipple. The apex beat of the heart is felt in the fifth interspace, about 2.5 cm. (i in.) to the inner side of the hne of the nipple. Running down behind the costal cartilages and crossing the intercostal spaces about a centimetre from the edge of the sternum is the internal mammary artery. When it reaches the sixth interspace it divides into the superior epigastric, which goes downward in the abdominal walls, and the musadophrejiic, which passes to the attachment of the diaphragm along the edge of the chest. ( The relations of the organs of the chest to the surface will be discussed later. The nervous supply to the surface of the chest is of interest mainly as indicating the probable location of the lesion in cases of fracture of the spine, and it will be described in the section devoted to the Back.) THE MAMMA OR BREAST. The name mammary gland is often oriven to the breast, yet the latter is composed not only of glandular tissue but also of fibrous and fatty tissue, with the usual vessels, nerves, and lymphatics. In the virgin female adult it is more spheroidal. Above the nipple it is flattened and below it is rounded. Its general shape is circular and it covers the chest-wall from the upper border of the third rib to the sixth interspace. Laterally it reaches internally almost to the sternum and externally it overlaps the edge of the pectoralis major. It lies imbedded in the superficial fascia. In its development it is simply a modified sebaceous gland. Beginning by a finger-like growth from the skin it burrows its way into the superficial fascia. — The secreting structure of the breast. (Piersol.) rests on the fascia covering the pectoralis major muscle. This is why we find almost no adipose tissue beneath the gland but mostly between the glandular structure and the skin and around its edges. The shape of the virgin breast is due mainly to its adipose tissue and not to its glandular structure. In those who have borne children the breasts become enlarged, lax, and pendulous. After lactation is completed they again retract but rarely regain their former shape. During lactation the fatty portion of the breast may disappear and leave it apparently in a shriveled condition, yet such a breast may be functionally quite active. Therefore the size of the breast is no criterion of its milk-producing powers. The secreting structure, racemose in character, is divided into ten to sixteen lobules each of which has its duct. These lactiferous ducts begin in the acini and end in the nipple. Beneath the nipple they are dilated, each forming a sinus or ampulla. While the shape of the breast is regular in its outline the glandular tissue is not so. It possesses three projections or cusps. One of these projects inward nearly or quite to the sternum, while the other two project toward the axilla and side, one being lower than the other. These are the most common According to H. J. Stiles {Ed. Med. Journ., 1892, p. 1099;, the secreting structure may extend posteriorly into the retromammary tissue between the layers of the pectoral fascia. Anteriorly it is prolonged with the fibrous tissue {ligaments of Cooper) almost to the skin. The nipple, located below and to the inner side of the centre of the gland, has connected with it some circular and longitudinal unstriped muscular fibres. The longitudinal ones are attached to the lactiferous ducts and serve to retract the nipple, the circular ones to erect it. Surrounding the nipple is the areola. It is pink in the virgin and about 2.5 cm. in diameter. After pregnancy its hue becomes brownish. The tubercles of Montgojnery are the numerous elevations found on the areola. They are more or less modified sebaceous glands and enlarge- during pregnancy. As they secrete a milky fluid, they are often regarded as accessory milk ducts. There is no fat in the nipple or areola. The fibrous structure of the gland envelops the adipose and glandular tissue. It is simply a continuation of the fibrous septa of the superficial fascia. These septa are attached to the skin above, envelop and pass between the fatty and glandular lobules, and form a thin covering for the under surface of the gland. The breast is sometimes spoken of as having a capsule, but that simply refers to the fibrous tissue just described. This fibrous tissue follows largely the ducts, hence when affected with carcinoma it contracts and draws the nipple in. This forms the retracted nipple of that disease. The fibres that go to the skin have been named the ligaments of Cooper. The fibrous tissue forms a net-work in the meshes of which are packed the glandular structure and fat-lobules. It is this which gives the firmness and shape to the virgin breast. In lactation, the fibrous tissue softens and stretches to accommodate the increase in the glandular structure and this, with the loss of fat, causes the breast to become lax and pendulous. In palpating a normal breast between the fingers and the thumb, this firmness may feel like a foreign growth; hence this method of examination is not to be relied on. A better way is to have the patient recline, and lay the fingers flat on the breast, compressing it on the chest-wall beneath. This flattens the glandular structure and any mass can be more surely detected. The fibrous tissue between the glandular structure and the pectoralis beneath is quite thin and loose, with large spaces in it which have been called the submammary bursa. Pus readily spreads in this loose submammary tissue, but in the gland itself only with difficulty. Blood Supply. — The breast is supplied witn blood from above by the pectoral branch of the acromial thoracic artery, v\hich leaves the axillary artery at the inner border of the pectoralis minor muscle. The pectoral branch descends between the pectoralis major and minor and anastomoses with the intercostals and long thoracic. It sends branches through the pectoralis major muscle, and in carcinoma of the gland it may be seen much enlarged running downward on the chest- wall beneath the muscle. From the inner side come \k\& peif orating branches of the internal mammary artery from the second to the sixth rib; the second, third, and fourth are the largest and may bleed freely in detaching the pectoralis major. To the outer side and below is the long thoracic artery, also called the external mammary; it descerds along the outer edge of the pectoralis minor, sending branches inward aroun' ne edge of the pectoralis major to the mammary gland. The inicrcostal arteries also contribute somewhat to the blood -'Lpply of the gland. Lymphatics. — Thi breast is exceedingly well supplied with lymphatics. They are composed of a aeep set around the lobules and ducts, and a superjicial s&i which together with the deep lymphatics forms a plexus around the nipple called the subareolar plexus. They drain mainly toward the axilla into the lymph-nodes along the edge of the pectoralis major but also communicate with the nodes around the subclavian artery and those in the anterior mediastinum which accompany the internal mammary artery. The axillary nodes are in three sets: one along the edge of the pectoralis major muscle {pectoral nodes), another further back along the anterior edge of the scapula {scapular nodes), and a third following the course of the a.xillary artery (^humeral nodes). In additic to these there are some infraclavicular or subclavian 7iodes between the deltoid and ^ ^ctoralis major and at the inner ed^J, jf th( oectoralis minor muscles; these are comparatively rarely involved primarily. The axillary nodes are continuous and communicate with the subclavian and supraclavicular nodes, and these latter are frequently enlarged subsequent to the axillary infection. The anastomosis of the lymphatics across the median line has been thought to account for the occurrence of the disease in the opposite breast or axilla. As shown by Sappey, some if not all of the lymphatics of even the sternal portion of the breast drain into the axilla and not into the anterior mediastinum, thus accounting for the axillary involvement when the inner portion of the breast is affected. These five sets of nodes communicate with each other, and any one may be alone involved. The supraclavicular set do not become involved primarily because no vessels run directly from the breast to them; they are affected secondarily to involvement of the axillary or subclavian sets. The deep lymphatics of the breast, according to Sappey, follow the ducts to the areola, there anastomosing with the superficial Ivmphatics to form what he called the S2ibareolar plexus, which drains by two trunks into the axilla. The lymphatics of the breast anastomose with those of the surrounding structures; hence in certain cases the pectoraUs muscles and even the pleura may be affected, and when the disease is widely disseminated by the lymph-channels on the chest- walls there is produced the thickei ', brawny, infiltrated condition known as the cancer " <?« cuirasse'^ of Velpeau. Nerves. — The breast and the skin over it are supplied from the descending branches of the cervical plexus, by thoracicbra'^ches from the brachial plexus, and by the second, third, fourth, fifth, and sixth intercostals. These are not of so much practical importance as the lateral branches of the second and third intercostal nerves. . That of the second is called the intejxostobrachialis (^humeral ) nerve ; it crosses the axilla, anastomoses with the medial brachial {lesser internal) cuta7ieous nerve, and supplies the skin of the inner and upper portion of the arm. The third intercostal anastomoses with the second and gives a branch to the arm and to the dorsum of the scapula. These nerves are certain to be seen in clearing out the axilla. Their division is accompanied by no paralysis, but disturbance of them accounts for some of the pain and discomfort following the operation. Abscess of the Breast. Suppuration in the mammary gland is usually due to infection which has entered the gland either through the lymphatics or the lactiferous ducts. The starting point of the infection is thought to be an ulcerated crack or fissure of the nipple. Infection travelling into the gland by way of the lymphatics would cause pus primarily in the pericanalicular tissue but it would soon involve the lactiferous ducts and then pus might exude from the nipple. Infection travelling up the ducts might reach the ultimate lobules and therefore give rise to widespread and multiple abscesses. Suppuration in this gland resembles that in the parotid gland, already described. When the body of the gland is involved it is apt to be so in more than one spot. The infection follows the branching of the ducts and usually there are several small abscesses instead of one large one. If there is a large collection of pus it is not contained in one cavity but more likely in several. This is so often the case that in treating these abscesses it is advised that they should not only be incised but the finger should then be introduced and the partitions separating the various abscess cavities broken through. In its incipiency a lymphatic infection may cause a single collection of pus, but this soon breaks through into the canaliculi and infects and involves the glandular structure. In an early stage of duct infection several inflammatory areas may start up about the same time. The pus soon breaks through the canaliculi and involves the periglandular tissue so that in each mode of infection the condition soon becomes the same. It is for this reason that it is difificult to . ay whether the infection originated in the lymphatics or the ducts. When the ducts are inflamed the pus often finds a vent at the nipple. The frequency of this is the reason why direct infection of the ducts is regarded as the more common mode. In incising a mammary abscess the incisions should follow the course of the du'^ts, that ^s, they should be made in a direction diating from the nipple towards the circi iferei ce and not transversely, otherwise healthy ducts will be divided. Submammary Abscess (for subpectoral abscess see page 264). — As has been pointed out some of the glandular tissue dips down to the pectoral fascia, hence when some of these deepest lying lobules are inflamed the pus instead of breaking laterally into the adjoining lobules or tissue breaks into the submammary tissue and bursa. Here it spreads rapidly beneath the gland and raises the gland above it. As the pus accumulates it sinks downward and works its way outward to the lower outer quadrant along the edge of the anterior axillary fold. Here is where it should be opened. As the cavity is single one incision is sufficient to drain it. years. They are not in any way dangerous. They are composed of a number of dilated acini. Another form is degenerative in character, occurring in the dechne of life, and consists of a large number of various sized, usually small, cysts located mostly toward the deep surface of the gland. They contain mucoid and degenerated material produced by the lining membrane of the acini. The whole breast is apt to be studded with small shot-like cysts and both breasts are usually involved. This affection in itself is not malignant, but it may become so by intracanalicular growths springing up from the walls of the cysts. AdoiomatoHS growths are encapsulated, usually single, and are composed of three distinct elements. These are glandular tissue more or less normal in character, glandular tissue cystic in character, and fibrous tissue. The fibrous tissue forms the capsule as well as the stroma in the meshes of which latter glandular tissue, nearly normal, occurs. These are called fibro-adenomata and if the glandular tissue is quite abundant they may be called adenomata. If the glandular acini are dilated so as to overshadow the fibrous portion, then it is called a cystic adenoma. These cystic growths may be quite large. mata or carcinomata. Sarcomata originate from the fibrous stroma of the breast surrounding the ducts and acini. As it increases in size it may irritate the glandular structure and obstruct the ducts, thus forming cysts which may be quite large. Such a growth has been called a cystic sarcoma. It also shows itself as a single tumor, which may be large but solid. The lymph-nodes are rarely affected. The disease when it wanders from the seat of the primary growth shows itself in some of the internal organs. It is disseminated by the blood and not by the lymphatics. Carcinomata originate from the epithelium lining the ducts and acini. For our purposes we may divide them into two classes, those that grow into the ducts {intracanalicular) and those that break through the ducts and invade the surrounding tissues, of these scirrhiis is the type. hitracanalicnlar groivths have by many authors been considered nonmalignant on account of the rarity of their producing general infection. They grow at times rapidly and produce tumors of considerable size. On section they contain many cysts and into these cysts, which are derived from the dilated milk-ducts, protrude outgrowths from the walls. Sometimes the cavity of the cyst has its liquid contents replaced by the solid tumor which has grown into it. A discharge of bloody serum from the nipple is common in these growths. Scirrhiis is the ordinary form of cancer of the breast. It starts in the epithelial structures of the gland, breaks through the basement membrane and involves the structures immediately adjacent to it, and is disseminated more widely by the lymphatics. Pagef s disease is a true carcinoma which begins as an eczema or ulceration around the nipple and later becomes disseminated. Carcinoma follows the gland structure, and readily involves the pectoral fascia covering the pectoralis major muscle. Anteriorly, the gland structure in places follows the ligaments of Cooper to the skin above, hence the frequency with which the skin is involved. The scirrhus variety does not involve the ducts in the same manner as does the intracanalicular variety, hence bloody discharges from the nipple are not so common as in that affection. The disease, when affecting the region of the nipple, has been considered more dangerous because of the greater development of the lymphatics, particularly the subareolar plexus of Sappev, at that point. Carcinomatous disease extends especially by way of the lymphatics. These follow the fibrous and canalicular structure, therefore on section the cancerous tissue can be seen extending like roots into the surrounding gland. This tissue shrinks, contracts, and becomes harder as the disease progresses, that is why retraction of the nipple and dimpling of the skin occurs. The most free lymphatic drainage occurs toward the axilla, not toward the mediastinal nodes. The first nodes to show infection are those lying along the edge of the pectoralis major muscle about the level of the third rib. Later, the nodes at the anterior edge of the scapula accompanying the subscapular artery become involved, or those along the axillary vessels. Still later and farther inward behind the sternomastoid muscle low down. In rare instances the disease may be carried superficially to the subclavian nodes in the infraclavicular triangle between the deltoid and pectoralis major muscles. Should the disease spread, it may be carried by the lymphatics to the opposite breast directly across the median line. If it involves the lymphatics of the chest- wall generally there is produced the brawny condition of the skin called cancer ' V?z C2iirasse'' of Velpeau already alluded to. A cancerous nodule beyond the edge of the pectoralis major muscle is not necessarily an enlarged node, but may be due to the involvement of one of the cusps of the gland, which sometimes extend even into the axilla. Removal of the Cancerous Breast. — The origin of cancer is now believed to be local and not general and the more complete its removal the greater is the hkelihood of cure. Therefore every effort is made to excise every possible infected tissue. This has led to the performance of very extensive operations. The incision is made so large as to include nearly or quite all of the skin covering the glandular tissue; this is because of the intimate connection of the two, as already pointed out. It is carried out to the arm; this is to facilitate clearing out the axilla and all its contents. The incision is kept close to the skin; this is to avoid any glandular structure which may possibly be beneath. The pectoral fascia covering the pectoral muscle is always removed. Often both the pectoralis major and minor muscles are removed. In excising them the slight interspace between the clavicular and sternal fibres of the pectoralis major muscle is entered and the muscle detached from the anterior extremities of the ribs and sternum. In so doing the anterior intercostal arteries, particularly those of the second, third, and fourth spaces, are liable to bleed freely. As the pectoralis major is detached and turned outward, the acromial thoracic artery is seen at the inner edge of the pectoralis minor muscle with its pectoral branch running down the surface of the chest. This may be ligated, the finger slipped beneath the pectoralis minor, and this muscle cut loose from the coracoid process above and the third, fourth, and fifth ribs below. At this stage some operators clear the subclavian and axillary vessels of all loose tissues and lymph-nodes. The vessels are followed out on the arm. When the insertion of the pectoralis major is reached it is detached and the whole mass turned outward and pared loose along the anterior edge of the scapula. Thus it is removed in one piece. The part of the chest-wall which has been cleared ofl embraces from the middle or edge of the sternum to the anterior edge of the scapula and from near the lower edge of the chest below to the clavicle above. The vessels have been cleared off from the insertion of the axillary folds on the arm to underneath the clavicle. Many operators make an additional incision above the clavicle and clear out the supraclavicular fossa even if no enlarged glands can there be detected. Sometimes the long thoracic artery and thoracicalis longus (long external thoracic) nerve may be wounded, but they need not be. (See note, page 191.) Two nerves will be seen crossing the axilla from the chest to the arm. They are the lateral branches of the second and third intercostal nerves. The second is called the intercostobrachialis (humeral) nerve. If they can conveniently be spared it is to be done, otherwise they are divided. In clearing the axillary vessels, small veins and even arteries may be divided close to the main trunks. These may be expected to bleed freely but are usually readily secured. Care should be taken not to wound unnecessarily the subscapular artery and particularly the vein as they wind around the anterior edge of the scapula 2 to 3 cm. below its neck. Some operators prefer to detach the breast from without in instead of from within out as described. THE MEDIASTINUM. The mediastinum is the middle space of the chest between the spine behind, the sternum in front, and the pleurae to each side. It is subdivided into a superior mediastinum, which is the part above Ludwig's angle, between the first piece of the sternum in front and the vertebrae from the first thoracic to the upper portion of the fifth behind. The part below is divided into the anterior mediastinum, the middle mediastinum, and \h& posterior mediastimcm. Superior Mediastinum. — The upper level of the superior mediastinum is oblique, as it runs from the upper edge of the sternum to the first thoracic vertebra. The lower level of the superior mediastinum runs from the junction of the first and second pieces of the sternum to the upper border of the fifth (or lower border of the fourth ) thoracic vertebra. Laterally it is bounded by the pleurce and apices of the lungs. The distance from the anterior surface of the spine to the posterior surface of the sternum is quite small, being only 5 to 6 cm. (2 to 25^ in.). Through this pass most important structures. The trachea and oesophagus are in the median line as well as the remains of the thymus gland. To each side are the great vessels, the innominate artery being on the right and the subclavian and carotid on the left. The left innomi7iate vein crosses transversely just below the top of the sternum to meet the innominate vein of the right side and form the superior vena cava. Into the innominate veins empty the inferior thyroid, vertebral, superior intercostal, i)iternal mammary, and pericardial veins ; and into the descending vena ca\-a empties the vena azygos major. On the posterior surface of the oesophagus and afterwards to its left side passes the thoracic duct. The trachea bifurcates opposite the junction of the first and second pieces of the sternum, and the transverse portion of the arch of the aorta rises as high as the middle of the manubrium. The phrenic nerves lie against the pleura, the right having the vena cava to its inner side. The right vagus { pne^imogastric') nerve comes down between the innominate artery and vein and passes downward on the posterior surface of the oesophagus. It gives its recurrent laryngeal branch off at about the right sternocla\'icular joint. The left vagus nerve comes down to the outer side of the left carotid artery and goes over the arch of the aorta, giving of? its recurrent laryngeal branch, and thence proceeds to the anterior surface of the oesophagus. The presence of the trachea in the median line and the edges of the lungs which meet opposite the second rib give a resonant percussion note to the first piece of the sternum. With all these important structures crowded in the small space between the vertebrae and sternum it is easy to see why tumors in this region should cause serious symptoms. Aneurism in\-olving the arch of the aorta and the great vessels is common. Tumors, such as sarcoma, carcinoma, and glandular, though rare, do occur. Abscess from high dorsal Pott' s disease has been known to cause serious effects. The symptoms of all these affections resemble one another to a considerable extent. Interference with the blood-current, usually in the veins, almost never in the arteries, is marked. Alteration in the voice is produced by pressure on the recurrent laryngeal nerves. Dyspncea from the pressure on the trachea and difificulty in swallowing also occur, as well as interference with the circulation and the presence of dulness over the region of the manubrium. Anterior Mediastinum. — This is the space below the second costal cartilages, between the sternum in front, the pericardium behind, and the two pleurae on the sides. It is only a narrow slit in the median Hne abo^'e from the second to the fourth costal cartilage; from here the right pleura is prolonged obliquely down and outward to the seventh costal cartilage, which it follows. On the left side the pleura leaves the median line about the fourth cartilage and passes out about 2 cm. to the left of the sternum and then down to the seventh costal cartilage, uhich it follows. The triangularis sterni musc/e arises from the under surface of the lower third of the sternum and from the xiphoid cartilage and passes upward and outward to insert into the costal cartilages of the second to the sixth ribs inclusive. The 7nuscle lies in front of the anterior mediastinum and the internal mammary artery runs down between it and the bone about i cm. distant from the edge of the sternum. There are a few lymphatic nodes in the anterior mediastinum on the diaphragm below and in the superior mediastinum on the arch of the aorta and left innominate vein above. A chain of nodes also accompanies the internal mammary artery along the edge of the sternum between the pleura and chest wall. Absct'ss of the anterior mediastinum may result from infection due to injury or punctured wounds. It may break into the pleurae on the sides, into the pericardium posteriorly, work its way down toward the abdomen, or point in the intercostal spaces at the edge of the sternum. Paracentesis pericardii is performed in the sixth interspace close to the sternum; also, the fifth and sixth cartilages may be resected, the internal mammary artery ligated, and the pericardium opened and even drained. If one attempts to pass a trochar into the pericardium by a puncture through the fifth or sixth interspace sufficiently far out to avoid wounding the internal mammary artery the pleura is apt to be wounded, as it passes farther toward the median line than does the lung. The Middle Mediastinum. — The middle mediastinum is limited in front by the anterior wall of the pericardium and behind by the posterior wall of the pericardium and roots of the lungs. It contains the heart with the lower half of the descending vena cava and the vena azygos major emptying into it, and the ascending aorta; dium and pleurae anteriorly. The bronchial lymphatic nodes are numerous between the structures forming the roots of the lungs. It is these nodes that are so often enlarged in diseases of the lungs. They are aflected in malignant disease as well as in tuberculosis, etc. Enlargements of the heart pressing on the vessels, particularly the vena azygos major, are sometimes thought to cause pleural effusions, especially if one-sided. to side. Posterior Mediastinum. — The posterior mediastinum extends from the pericardium and roots of the lungs anteriorly to the vertebrae posteriorly. The pleurae are on each side. Behind the pericardium runs the (esophagus, lying in front of the ao7'ta, which rests on the vertebrae. In the chink between the aorta and bodies of the vertebrae lies the thoracic duct and immediately to its right side is the vena azygos the seat of aneurism. Mediastinal Tumors. — Cancer is the most frequent malignant new growth, then sarcoma and lymphoma. Great enlargement of the lymph-nodes occurs in Hodgkin s disease and is probably a factor in causing a fatal issue. Enlargements also result from tuberculosis and other diseases. They give rise to pressure symptoms. Dyspnoea may be due to pressure on the trachea or heart and great vessels. The circulation may be so much impeded that the enlargement of the collateral veins, especially those of the surface, may be \'ery marked. There may also be difficulty of swallowing due to pressure on the oesophagus. Pleural Effusions. — Serous effusions into the pleurae are also known to accompany heart disease and have been attributed in some instances to obstruction of the circulation. They are apt to be unilateral and are most often found affecting the right pleural cavity. Baccelli attributed the efiusion to obstruction of the blood current through the vena azygos major ; the enlarged heart pulling the superior vena ca\'a down drew the vena azygos major tightly over the right bronchus, as is well shown in Fig. 210. Steele ( Univ. Med. Mag., 1897 \ Jonrn. Am. Med. Asso., 1904) and Stengel ( C/niv. Penna. Med. Bulletin, 1901 j held that the dilated right heart by extension upward exerts pressure on the root of the right lung and indirectly pinches the azygos major vein as it curves over the right bronchus to enter the superior vena cava. Fetterolf and Landis (^Atn. Journ. Med. Sciences, 1909) believe that the fluid comes from the visceral pleura and not from the parietal pleura, and that the outpouring, so far as the pressure factor is concerned, is caused by dilated portions of the heart pressing on and partly occluding the pulmonary veins. They point out that Miller (Am. Joicrn. of Anat., vii) has shown that the veins draining the visceral pleura empty into the pulmonary veins ; therefore, if these latter are obstructed, transudation may ensue ; this may occur on either side. They point out that if the right atrium (auricle) dilates, it expands upward and backward and compresses the left auricle and root of the right lung; and of the parts composing the root the pulmonary veins are the most anterior, and, therefore, the ones most liable to be compressed. Left-sided effusions are accounted for by compression of the left pulmonary vein by the dilated left atrium (which is the most posterior of the four chambers) and its appendix. The greater frequency of right-sided effusions is due to the more common occurrence of dilatation of the right side of the heart. [W. S. Handley {Brit. Med. Journ., Oct. i, 1904) claims that the principal method of dissemination of carcinoma of the breast is not by the lymph stream or blood current but by spreading peripherally along the coarser meshes of the lymphatic channels which exist in the deep pectoral fascia. These are continuous downward with the surface of the recti muscles. He therefore advises that the lower end of the usual skin incision be prolonged downward and inward so ' ' that every particle of the origin of the great pectoral from the rectus sheath, and the surface of the latter, on both sides of the middle line, should be most carefully cleared ' ' as far as two to three inches below the tip of the ensiform cartilage. ] In the middle of the surface of the chest anteriorly there are three regions: I. The suprasternal region is the part above the sternum between the sternomastoid muscles. It is the suprasternal notch. the third rib. 3. The mammary region, from the upper edge of the third to the upper margin of the sixth rib. This extends from the edge of the sternum to the anterior axillary fold and has the nipple nearly in its centre. The pleurae form closed sacs which line the thorax (parietal pleura) and cover the surface of the lungs (visceral pleura). As the lungs expand and contract, the pleurse are only completely in contact with the lungs when the latter are fully distended. In ordinary breathing the lungs are not completely expanded, hence the edges of the pleurae fall together and so prevent the formation of a cavity. This collapsing of the pleurae takes place mainly along its anterior and lower edges. The apex of the pleura is prevented from collapsing by its attachment to the first rib, and also, as pointed out by Sibson, by the attachment to it of an expansion of the deep cervical fascia and some fibres of the scalenus anticus muscle. Posteriorly the chest wall is unyielding. Anteriorly when the lungs are collapsed they fill out the pleura as low down as the fourth costal cartilage ; below that, in front of the heart. a space or sinus is left unoccupied by lung. It is called the costomcdiastinal sinus. Likewise between the diaphragm and chest-walls is another space, in which the parietal or costal and visceral layers of the pleura are in contact, called the cosiophrenic sinus or complcmcntal space of Gerhardt. From these facts it follows that the outlines of the pleune and lungs are identical posteriorly, superiorly, and anteriorly, as low as the fourth costal cartilage. Here they diverge, the pleurae descending lower than the lungs. The top of the pleura is about on a plane with the upper surface of the first rib. This makes its posterior portion at the head of the first rib 5 cm. higher than its anterior portion at the anterior end of the first rib. The upper border of the clavicle is level with a point midway between the anterior and posterior ends of the first rib. This, therefore, shows the pleura to extend 2.5 cm. (i in.) above the level of the upper surface of the clavicle. The top of the pleura does not project into the neck in the form of a cone, but resembles a drum-head, being stretched in the form of a plane almost or quite level with the top of the first rib. Its upper surface is strengthened by fibres from the deep fascias of the neck and, according to Sibson, by some fibres from the scalene muscle. The pleura then slopes forward behind the sternoclavicular joint to meet the pleura of the opposite side at the level of the second costal cartilage, a little to the left of the median line. They then descend until opposite or a little below the fourth costal cartilage, when they each diverge toward the side, reaching the upper border of the seventh costal cartilage near its sternal junction. They then slope down and out, reaching the lower border of the seventh rib in the mammary line, the ninth rib The scapular line intersects the lower edge of the pleura at about the eleventh rib. In operations involving the lumbar region, if the incision is carried high up posteriorly the pleura may be opened along the lower border of the posterior portion of the twelfth rib. It soon recedes from the costal margin and in the axillary line is about 6 cm. (2^ in.) above it. THE LUNGS The lungs entirely fill the pleural sacs when completely distended, but only partly so in quiet, ordinary respiration. They are encased in a bony cage that is open below, on account of which, when the lungs distend, they expand mostly downward. To a less extent they expand, in forced respiration, both laterally and anteroposteriorly, due to the elevation of the ribs owing to the traction of the muscles upon them. Ordinary breathing is performed mainly by the diaphragm. It acts like the piston of a cylinder and as it descends the air is drawn into the trachea and lungs. As the diaphragm falls a negative pressure is produced within the chest and were it not for its bony framework, it would collapse. The framework is sufficiently strong to retain its shape in spite of this pressure if the breathino- is normal and the chest-walls are healthy. When, however, obstruction of the airpassages is present, perhaps from enlarged pharyngeal or faucial tonsils or nasal hypertrophies, then the deformities known as funnel-breast, pigeon-breast, etc., already described, arise. They are also produced if there is no obstruction to the breathing but only a weakness in the bony thorax, as occurs in rickets. Two of the most common of the diseases of the lungs produce changes in the shape of the thorax ; they are emphysema and phthisis. Pneumonia, though a frequent enough disease, does not produce any changes, as it is too short in its duration. In emphysema the lungs are in a state of hyperdistention, hence they fill the chest to its greatest capacity and tend to make the soft parts bulge between the ribs. In phthisis the lungs are contracted, hence the intrathoracic pressure becomes a negative one and the soft parts sink in between their bony support. In emphysema the anteroposterior diameter increases and the chest assumes the barrel-form already described. In phthisis it becomes lessened in its anteroposterior diameter and we have the flat chest. Enlargement of the chest posteriorly is impossible on account of the support of the ribs, vertebrae, and strong back muscles. Enlargement downward is allowed by a descent of the diaphragm ; hence the fulness of the abdomen in those affected with emphysema and conversely the flatness of the abdomen in those having phthisis. In the region of the apices the thorax is closed by the deep fascia, which spreads from the trachea, cesophagus, muscles, and great vessels and blends with the pleura to be attached to the first rib. In the normal condition this is level with the plane of the first rib and rises little if at all above it. Even in disease it is not materially altered. This is certainly so in phthisis and probably so in emphysema. The apparent fulness of the supraclavicular fossae and intercostal spaces in emphysema and the increased depth of these hollows in phthisis are not due so much to a bulging or to a retraction of the lungs at these points as to the atrophy of the fatty and muscular tissue in phthisis and to the muscular tension in emphysema. In coughing, the apex of the lung does not jump up into the neck above the clavicle as it appears to do, but remains nearly or quite below the plane of the top of the first rib. The appearance of bulging is caused by the movements of the trachea in the median line and the muscles laterally. This is noticeable particularlv in the case of the platysma and omohyoid muscles. In quiet breathing the posterior belly of the omohyoid lies about level with the clavicle, but in coughing it rises i or 2 cm. above it. The intercostal membranes and muscles are kept tense by the constant elevation of the ribs due to the muscular tension. OUTLINE OF THE LUNGS. Apex. — The apex of the lung has its highest point opposite the posterior extremity of the first rib. It then follows the plane of the top of the first rib down to the sternoclavicular joint, immediately above the junction of the cartilao-e of the first rib with the sternum. The anterior end of the first rib is 5 cm. lower than the posterior. The upper edge of the clavicle is 2. 5 cm. or one inch, above the anterior end of the first rib and 2.5 cm. below the head of the first rib, hence the apex of the lung rises 2.5 cm. (i in.) above the clavicle, and it lies behind its inner fourth. This distance will vary in different individuals with the obliquity of the ribs. The more oblique the ribs the greater will be the distance between the le\'el of the top of the clavicle and that of the neck of the first rib. Anterior Border. — From the sternoclavicular joint the borders of the lungs pass downward and inward until they almost or quite touch in the median line at the angle of Ludwig opposite the second costal cartilage. They continue downward almost in a straight line until opposite the fourth costal cartilage, where they begin to diverge. The border of the right lung proceeds downward and begins to turn outward opposite the sixth cartilage. The left lung on reaching the level of the fourth costal cartilage curves outward and downward across the fourth interspace to a point about 2.5 cm. to the inner side of the nipple in the fourth interspace. From this point it goes downward and inward across the fifth rib and interspace to the top of the sixth rib about 3 cm. to the inner side of the nipple line. This isolated tip of lung just above the sixth rib over the apex beat of the heart is called the lingula. Lower Border. — The lower edge of the lung varies in different individuals and in the same individual according to the amount of inflation. In quiet respiration it is about opposite the sixth cartilage and rib from the sternum to the mammary line, opposite the eighth in the midaxillary line, the tenth in the scapular line, and the eleventh near the vertebrce. The right lung has two fissures and three lobes, an upper, a middle, and a lower. The fissure of the left lung begins above and posteriorly opposite the root of the spine of the scapula; this is level with the fourth rib and third dorsal spine. It passes downward and forward, ending at the sixth rib in the parasternal line. It crosses the fourth in the midaxillary line. The lower lobe of the right lung is of the same size as that of the left side. The lung above it is divided into a middle and upper lobe. The main fissure of the right lung corresponds in its course almost exactly with that of the left lung. It begins above and posteriorly at the root of the spine of the scapula and passing downward crosses the fourth rib in the midaxillary line and ends at the sixth rib in the mammary line (instead of the parasternal line as in the left). The subsidiary fissure of the right lung leaves the main fissure at the posterior axillary line opposite the fourth rib and follows this rib in an almost horizontal direction to its junction with the sternum. In order to recognize and appreciate the changes which occur in the lungs in lobar pneumonia it is necessary to know the outlines and limits of the various lobes of the lungs. A knowledge of the exact course of the fissures of the lungs is not only necessary to outline the lobes, but it. is of service in the diagnosis of pleural effusions. These effusions often are limited to certain localized areas instead of being general. Pleurisy may affect the lung bordering the fissures. When such is the case, the effusion, serous or purulent, may be in the fissure itself and embrace but little of the general pleural cavity. Dry taps from failure to hit the purulent or serous collection are not infrequent, and the possibility of its being interlobar should be borne in mind. CxENERAL CONSIDERATIONS. From what has been said it follows that a knowledge of the extent and outlines of the lungs and of the location and course of the fissures is essential to the proper diagnosis and treatment of affections of both the lungs and pleurae. The extent of the lungs is determined in the living by percussion. The apex of the lungs forms an oblique plane rimning upward and backward from just below the lower edge of the inner extremity of the clavicle to the neck of the first rib above and posteriorly. The level of these two points will vary according to the inclination of the ribs, which in turn is influenced by the direction (vertical ) of the spine. Ordinarily the distance is 5 cm. (2 in.). It may be even as much as 7 or 8 cm. The top edge of the clavicle passes across the middle of this distance so that the top of the lung is about 2.5 cm. (i in.) above the clavicle. The highest point of the lung is not in the middle of the space enclosed by the first rib, but is at its posterior border, at the neck of the first rib. backward. If the patient is standing erect the first rib will slope downward and forward at an angle of 65 degrees, or more, with a vertical line. The spine will slope downward and backward from the same vertical line in a normally straight back about 20 degrees. In people with straight backs and flat chests (often seen in phthisis), the sloping downward of the ribs is marked; in those with rounded backs the chest is apt to be round, as in emphysema, and then the ribs are more horizontal. Another point to be noticed is the lateral extent of the apex of the lung in relation to the length of the clavicle. The lung does not extend farther out on the clavicle than one-fourth its length. The clavicular origin of the sternomastoid muscle extends out one-third of the length of the clavicle, so that the lung is behind the clavicular origin of the sternomastoid and care should be taken not to percuss too far out. If the finger is laid in the supraclavicular fossa in percussion it should be pressed downward and inward, not backward. Posteriorly the scapula rises to the second rib and its spine has its root opposite the fourth rib or spinous process of the third thoracic vertebra. Therefore a small portion of the lung is above the upper edge of the scapula and percussion in the supraspinous fossa gives a clear resonant note. pleural effusion. inward from the sternoclavicular joints to meet nearly or quite in the median line and so continue to the level of the fourth rib; hence it follows that the percussion note on the sternum nearly down to this point is resonant and if it be found to be dull one should look for an aneurismal or other tumor which is displacing or covering the lungs and trachea at this point and thereby subduing their resonance. In performing abdominal operations, as those involving the gall-bladder and kidney, the surgeon may be tempted to prolong his incision upward into the lower edge of the chest-walls, and it is necessary to know how far he can proceed without opening the pleural cavity. This necessitates his knowing how far from the lower edge of the chest the pleura lies. It reaches to the seventh rib in the mammary line, the ninth in the axillary line, and the twelfth posteriorly, extending to its extreme lower edge. In emphysema the lung, being- distended, occupies more nearly the outlines of the pleura and its area of resonance is increased. In pleural effusion it is compressed and even sometimes collapsed. As it shrinks it recedes inward and backward and is pushed from the chest-wall by the layer of fluid (Fig. 217). The pressure of the fluid within causes the intercostal spaces to be obliterated and sometimes even to bulge instead of being depressed. As the expansion of the lung is prevented, the chest does not move on the affected side, or expand with the respiration, as it does on the healthy side. This can be demonstrated by measuring the two sides of the chest. At the end of expiration the affected side will be from i to 3 cm. greater in circumference than the healthy one. If the pleural effusion is on the right side it may push the heart to the left and raise its apex beat and cause it to pulsate beyond the nipple line and even in the axilla. If it is on the left side the costomediastinal sinus (page 196) becomes distended with fluid or plastic lymph and this obscures or conceals the heart's impulse. If the effusion is very large the heart is pushed over toward the right and its apex beat is seen in the third or fourth interspace on the right side even so far over as the mammary line. Should the effusion be purulent it may perforate the chest- wall, or open into the pericardium anteriorly, the oesophagus posteriorly, and into the stomach or peritoneal cavity below. If it perforates the chest- wall it usually does so anteriorly between the third and sixth interspaces, most often in the fifth. an aspirating needle or trocar. For diagnostic purposes a hypodermic syringe needle is often used, as the chestwalls are usually thin enough to allow this to be done, particularly if a suitable spot is chosen and the patient is a cnild. Care should be exercised not to strike a rib. The spot chosen for puncture may be indicated by dulness on percussion. It may be anywhere, but when a choice is permissible the puncture should be made in the sixth interspace about in the middle or postaxillary line. Another preferred spot is in the eighth interspace, below the angle of the scapula. The sixth interspace may be determined in several ways, viz. : 1. Begin at the angulus sterni (angle of Ludwig) and follow out the second rib to the parasternal or midclavicular line, thence count down to the sixth rib and follow it to the midaxillary line. fifth rib. Follow it to the axillary line and go two spaces lower. 8. By raising the arm the serrations of the serratus anterior muscle attached to the fifth, sixth, seventh, and eighth ribs become visible; that attached to the sixth rib is the most prominent and is attached farthest forward. Empyema. — When the pleural effusion is purulent, tapping is not sufficient, ana drainage is resorted to. It is not considered necessary to open the pleural cavity at its lowest part but the sites chosen are usually the sixth or seventh interspace in the mid- or postaxillary line. The movements of the scapula are apt to interfere with drainage immediately below its angle, hence the opening is usually made farther forward. The surgeon may or may not resect a rib. Incision for Empyema. — In certain cases the condition of the patient may demand that as little as possible be done, and that quickly. The point c)f operation is selected by one of the guides already given, perhaps the level of the nipple. THE PERICARDIUM. 201 While the finger of one hand marks the interspace, an incision 4 cm. {i}4 in.) long is made along the upper edge of the rib, this is deepened by a couple of strokes which detach the intercostal muscles and carefully penetrate the pleura. As the pus makes its appearance the knife is withdrawn and the finger is laid on the opening. A drainage-tube held in a curved forceps is then slid along the finger into the chest. Sometimes a rubber tracheotomy tube is used for drainage purposes. Any bleeding will be from the small intercostal branches and can readily be stopped by gauze packing. artery running along the lower edge of the rib is the larger. Resection of a Rib for Empyema. — For the removal of a part of a rib a more formal operation is necessary. The incision is made directly on the rib down to the bone and five or more centimetres in length. The skin being retracted, the periosteum is incised and detached from the rib with a periosteal elevator which is passed down its posterior surface, pushing the pleura away from the rib. When the elevator reaches the lower border of the rib an incision is made down on it through the intercostal muscles, keeping as close to the rib as possible to avoid wounding the intercostal artery, which lies close to its lower edge. The rib is then divided either with a cutting forceps like Estlander's, or a Gigli saw. The rib, having been divided at one end of the incision, is then lifted up, the pleura stripped off, and divided at the opposite end. Should the intercostal artery bleed, and it is often sufficiently large to spurt quite actively, it can be caught with a haemostatic forceps and secured with a ligature if necessary. This is safer than to trust to packing, on account of the lack of support due to the removal of the rib. After the incision is completed, the pleura is incised and the tube introduced. In ligating the intercostal artery, care should be taken not to include the nerve which lies close to but below it; that is, farther away from the rib. drainage is instituted. The pericardium in shape is somewhat conical. Its base rests on the central tendon of the diaphragm and its apex envelops the great vessels, as they emerge from the base of the heart, for a distance of 4 to 5 cm. The attachment to the diaphragm is most firm at the opening of the inferior vena cava. As the fibrous layer of the pericardium proceeds upward it becomes lost in the fibrous tissue (sheath) covering the great vessels. This is continuous above with the deep cervical fascia, especially with its pretracheal layer. Anteriorly the pericardium is attached above and below to the sternum by the so-called sternopericardiac ligameiits (Fig. 218). In front of it above are the remains of the thymus gland and triangularis sterni muscle of the left side from the third to the seventh costal cartilages. The internal mammary arteries, running down behind the costal cartilages about a centimetre from the edge of the sternum above and somewhat more below, are separated from the pericardium by the edges of the lungs and pleurae, these latter reaching nearly or quite to the median line. The triangularis sterni muscle also lies beneath the artery and farther from the surface. As the left pleura slopes more rapidly toward the side than does the right there is a small portion of the pericardium uncovered by the pleura at about the sixth intercostal space close to the sternum. The incisura of the left lung leaves a space where the pericardium is separated from the chest-walls only by the pleura. Owing to the fibrous nature of the pericardium it will not expand suddenly. While only about a pint of liquid can be injected into the normal pericardial cavity after death, if a chronic effusion exists in a living person as much as three pints may be present. Sudden effusion occurring in the living patient will cause obstruction of the circulation at the base of the heart; it may by pressure on the bronchi at the bifurcation produce suffocative symptoms and by pressure on the oesophagus difificulty in swallowing. The lungs are displaced laterally, and the stomach and liver downward. The largest effusions are slow in their formation. The part of the pericardium in contact with the chest-wall which is never covered by pleura is small. It embraces the space between the two pleurie from the fourth to the seventh ribs. This may be defined by three lines, one in the midline, another from the middle of the sternum opposite the fourth rib to the costosternal junction of the seventh rib, and a third joining these two passing through the articulation of the xiphoid cartilage (Fig. 219). The left pleural sac may be i cm. distant from the left edge of the sternum. Thus it is seen that there" is hardly a point where a needle can be introduced with the certainty of avoiding the pleura. The safest point is probably close to the left edge of the sternum in the sixth interspace. This interspace may not extend to the sternum, but even if the cartilages are in contact a needle could probably be introduced at this point. As the pericardium is distended it carries the lungs and to a less extent the pleura outwards and increases the area available for puncture both upward and downward as well as to the sides. When greatly distended the pericardium may reach to the first interspace above, 2.5 cm. f i in.) to the right of the sternum, to the seventh cartilage below, and to the left nipple line or even beyond. The arching of the diaphragm causes a sternophrenic sinus behind the sternum analogous to the costophrenic sinus at the lower edge of the chest. This becomes distended by pericardial effusions in the same manner as does the costophrenic sinus in pleural effusions. A puncture in the sixth space close to the left edge of the sternum enters this sinus. The increased area in cases of distention from pericardial effusions has led Osier to advise tapping in the fourth interspace, either at the left sternal margin or 2.5 cm. from it, or at the fifth interspace 4 cm. (i}4 in.) from the sternal margin ; or bv thrusting the needle upward and backward close to the costal margin in the left costoxiphoid angle. been overestimated, but when drainage is to be employed the danger is certain. Drainage of the Pericardium. — To drain the pericardium requires the removal usually of at least one of the costal cartilages. A drainage-tube can sometimes be introduced by first making a short incision in the fifth or sixth interspace close to the left edge of the sternum, then puncturing the pericardium, dilating the puncture with forceps, and introducing the tube. The costal cartilages usually lie so close together as to interfere with the proper introduction of a tube, hence the necessity of resection. A flap may be made or a straight incision. The latter is sometimes made over the fifth costal cartilage, which is then resected. If desired the sixth and seventh cartilages are also removed and even a piece of the left edge of the sternum. The intercostal muscles having been raised, the cartilages are removed. When the internal mammary artery is seen lying beneath, it is to be either ligated or drawn to one side. The triangularis sterni muscle is either incised or drawn to the outer side along with the edge of the left pleura. The pericardium can then be lifted with forceps and incised and the drainage-tube introduced. In size the heart is somewhat larger than the clenched fist. It measures 12.5 cm. (5 in.) in length, 7.75 cm. (3^ in.) in width, and 6.25 cm. {2}^ in.) in thickness. Its weight in the adult male is 250 to 300 Gm. (8 to 10 oz. ), in the female it is 60 Gm. (2 oz. ) less. It lies enclosed in its pericardium in the middle mediastinum between the sternum (from the upper edge of the third costal cartilage to the sternoxiphoid articulation) in front, and the bodies of the fifth, sixth, seventh, and eighth thoracic vertebrae behind. Laterally it reaches from two centimetres to the right of the sternum nearly to the left nipple line. On each side of it are the lungs, from which it is separated by the pleurae and pericardium with the phrenic nerves between. Above are the great vessels and below it rests on the central tendon of the diaphragm. In shape the heart resembles an acorn, the atria (auricles), forming the upper right portion and the ventricles the lower left portion. It lies with its right side resting on the diaphragm and its apex pointing forward and to the left. The base of the heart is opposite the upper border of the third costal cartilage. It is here that the superior vena cava ends and the aorta begins. It extends from 1.25 cm. (^^ in.) to the right of the sternum to 2.5 cm. (i in.) to the left of the sternum. The right border of the heart extends from 1.25 cm. (^ in.) to the right of the sternum at the upper border of the third costal cartilage in an outwardly cur\'ed line to the junction of the seventh rib and the sternum. In the fourth interspace it may reach 2.5 cm. (i in. ) beyond the right edge of the sternum. The lower border passes from the seventh right chondrosternal junction across the sternoxiphoid joint outward in the fifth interspace to the apex beat, which is 4 to 5 cm. ( I ^ in. to 1 3^ in. ) below and to the inner side of the nipple and about 8.75 cm. (3j^ in.) to the left of the median line. This marks the extreme left limit of the heart. In children the apex is higher — -it is in the fourth interspace. In old people it is lower. The atrio- (auriculo-) ventricular groove or line of junction between the atria (auricles) and ventricles runs from the sixth right chondrosternal junction upward and to the left to the third left chondrosternal junction. The atria lie above and to the right of this line and the ventricles below and to the left. The right atrium (auricle) and right ventricle lie anteriorly and the left atrium and left ventricle lie posteriorly. In the right atrioventricular groove runs the right coronary artery. As it lies on the anterior portion of the heart it is liable to be injured in stab-wounds and give rise to fatal bleeding, as may also the inter\entricular branch of the left coronary artery as it passes down near the left border of the heart between the right and left ventricles. The Portion of the Heart Uncovered by Lung-tissue. — When the lungs are distended the right lung covers the heart to the median line. The left lung leaves the median line at the level of the fourth costal cartilage and curves outward and downward to about the apex beat in the fifth interspace, 2.5 cm. to the inner side of the nipple line. At this point a small piece of the lung, the lingiila, sometimes curves around in front of and below the extreme tip of the heart. As the air leaves the lungs they retract and their anterior borders ha''dly reach the edges of the sternum. Area of Cardiac Dulness. — The area of cardiac dulness corresponds to the area uncovered by lung and in contact with the chest-wall. This is the area of absolute dulness. It begins opposite the fourth costal cartilage and extends down the sternum, between the median line and left edge, to the liver dulness below opposite the sixth costal cartilage. Toward the left side it arches from the fourth left costosternal junction to the apex beat. The area of so-called relative dulness caused byoverlapping of the lungs extends along the right edge of the sternum to opposite the upper border of the third rib above, and to the left follows parallel to the left border of the heart to the tip of its apex. Below it blends with the liver dulness (Fig. 221). area of dulness becomes increased. Cardiohepatic Angle (Ebstein). — This is the angle formed by the right border of the heart as it meets the liver. It is a more or less resonant area in the fifth right intercostal space. Below it is the liver dulness and above and towards the median line is the heart. VALVES OF THE HEART. There are two types of valves in the heart: the bicuspid (mitral') and U'icuspid between the atria (auricles) and ventricles, and the two sets of semiltinar valves at the entrance of the pulmonary artery and aorta. (See Fig. 220.) The bicuspid valve is the most important and is the deepest seated. It lies at the edge of the left border of the sternum opposite the fourth costal cartilage. It separates the left atrium and ventricle and lies nearly transversely. The tricuspid valve lies in the middle of the sternum opposite the fourth intercostal space. It runs obliquely downward and to the right from the third left intercostal space to the fifth right costal cartilage. It separates the right atrium and ventricle. The pulmonary semilunar valve lies opposite the sternal end of the third left costal cartilage. It is the most superficial valve and the one highest up on the sternum. It pre\-ents regurgitation of the blood into the right ventricle from the lungs. The aortic semilunar valve lies under the left side of the sternum about level with the lower edge of the third costal cartilage. It is just below and to the right of the pulmonary valve, and above and to the left of the bicuspid valve. position of the valves, but are as follows. The bicuspid sound is heard most distinctly at the apex of the heart as far inward as the parasternal line and as high as the third interspace. It is transmitted around the chest toward the axilla. The aortic sound is best heard in the second right intercostal space and the cartilage above is called the aortic cartilage. The aortic sounds are transmitted up the neck in the direction of the great blood-vessels. VARIATION IN SIZE AND POSITION OF THE HEART. The heart becomes enlarged both by being dilated and by being hypertrophied, usually both conditions are present; and its position is often changed by disease both of itself and of adjacent organs. It is apt to enlarge unequally. In emphysema and bicuspid regurgitation the right side becomes enlarged, the pulmonary circulation being impeded. In aortic disease, arteriosclerosis, muscular exertioi, or any cause impeding the course of the blood through the arteries there is produced an enlargement of the left side of the heart. The average weight of the healthy heart is in the male 280 Gm. (9 oz. ), and in the female 250 Gm. (8 oz. ). These may be doubled in cases of enlargement. When the heart is enlarged the apex beat changes its position; it may occupy the sixth, seventh, or eighth interspace instead of the fifth, and may be as far as 5 to 7.5 cm. (2 to 3 in. ) to the left of the nipple line. When it enlarges upward, instead of the absolute dulness beginning opposite the fourth costal cartilage, it is opposite the third or even the second interspace. Toward the right side the absolute dulness may extend a couple of centimetres beyond the right edge of the sternum, instead of being near its left edge as is normal. The heart is readily displaced by pressure from the surrounding structures. If there is abdominal distention by gas or ascites, or if the liver or spleen is enlarged, the heart is pushed upward. Enlargement of the liver may likewise depress the heart, if the patient is in an upright position, by the weight of the liver dragging it down. Aneurisms of the arch of the aorta, tumors, or emphysema may also depress it. In the aged the apex beat may be normally in the sixth interspace. Lateral displacement occurs in cases of pleural effusion. Osier says (" Pract. of Med.," p. 594), this is not due to a twisting of the heart on its axis but to a positive lateral dislocation of the heart and pericardium. Pneumothorax or tumors on one side may also push the heart toward the opposite side. It may be pulled to one side by pleural adhesions and in those cases of fibroid phthisis in which the lung becomes markedly retracted. Abscess or tumors of the mediastinum also displace it. The position of the pulsation of the heart is not always an indication of the position of the apex. In pleural eflusion the pulsation may be one, two, or three interspaces higher than normal, while the apex itself may not be elevated. Wounds of the heart are usually immediately fatal, but sometimes they are not so. The pleuree are very liable to be wounded at the same time. The right ventricle, on account of lying- anteriorly, is the part most often involved. The atria lie more posteriorly and are most apt to be wounded in stabs through the back. Not only may the substance of the heart itself be injured but also its blood-vessels. The right coronary artery lying in the atrioventricular groove and the anterior interventricular branch of the left coronary running between the two ventricles anteriorly are the vessels most liable to injury. Owing to the heart being enclosed in the pericardium,— a closed sac, — if blood accumulates in it the action of the heart is inter- closed, or distention of the pericardium may ensue. Wounds of the heart have been sutured successfully. In order to reach the heart, a portion of the chest-wall would have to be resected and turned to one side as a flap. This will probably require the opening of the pleural cavity. The pleurae will in all likelihood already have been involved and found to be filled with blood, as has occurred in at least one case. The aorta, as it leaves the left \entricle, begins under the left portion of the sternum opposite the lower border of the third left costal cartilage. This is the location of the aortic semilunar valves as already given. It passes upward toward the right for 5 cm. and then forms an arch, extending backward toward the left, to reach the spine on the left side of the body of the fourth thoracic vertebra. The arch is continued down in front of the spine as the thoracic aorta and pierces the diaphragm in the median line, between the two crura of the diaphragm, opposite the twelfth thoracic \ertebra. The ascending aorta begins behind the left half of the sternum on a level with the lower border of the third costal cartilage. It proceeds upward toward the right until it reaches the level of the lower border of the right second costal cartilage, where the arch begins. Immediately above its commencement it has three enlargements, called the shuises of the aorta (Valsalva), which correspond to the semilunar valves. Of the three semilunar vah'es two are anterior and one is posterior. From behind the two anterior \'alves come the right and left corona)-}' arteries. dilated, forming the great sinus of the arch of the aorta. The right limit of the aorta is about even with the right edge of the sternum; sometimes it projects slightly beyond. When it does so it is liable to be wounded by a stab in the second interspace close to the edge of the sternum. On account of the proximity of the aorta to the second interspace, it is here that the stethoscope is placed to hear aortic murmurs. The aorta at this ])oint is covered only by the thin border of the right lung and pleura and the slight remains of the thymus gland. Below, its commencement is o\'erlapped on the right by the anricnia dextra (right auricular appendix) of the atrium and on the left by the commencement of the pulmonary artery. upper right anterior portion. If the aneurism enlarges anteriorly it will show itself first in the second or third interspace. It will bulge the ribs outward in this region. The right lung will be pushed outward and the two layers of the pleura pressed together. It may break externally through the surface or open into the pleural cavity. If it tends to the right it presses on the descending cava and right atrium, thus interfering with the return of the blood from the head and neck and both upper extremities. If it enlarges to the left or backward it may press on the right pulmonary artery and interfere with the free access of blood to the lungs. The first portion of the aorta is not united with the pericardium, but simply loosely covered by it, so that this portion of the arch is weaker than the other portions, and rupture, with extravasation of blood into the pericardial sac, is not uncommon. An aneurism may also rupture into the superior vena cava. The arch of the aorta passes anteroposteriorlv from the upper border of the second right costal cartilage in front to the left side of the body of the fourth thoracic vertebra behind. It is about 5 cm. {2 in.) long. Its under surface is level with the angle of the sternum (angle of Ludvvig), opposite the second costal cartilage. Its upper surface rises as high as the middle of the first piece of the sternum, which is opposite the middle of the first costal cartilage, about 2.5 cm. (i in.) below the top of the sternum. Relatio7is. — In front of the arch the right lung and pleura cover it slightly, but the left more so; the remains of the thymus gland is between them. The left superior intercostal vein crosses its upper portion to empty into the left innominate vein. The left phrenic and vagus nerves also cross it, the phrenic being the farther forward and the vagus crossing almost in front of the point of origin of the left subclavian artery. Behind lie the trachea, oesophagus, and thoracic duct, also the left recurrent laryngeal nerve. The bifurcation of the trachea is directly behind and below the lower portion of the arch and the left bronchus passes beneath it. The oesophagus lies THE AORTA. compressed between the trachea and vertebrae with the thoracic duct immediately to the left. The left recurrent laryngeal leaves the pneumogastric on the front of the arch, then winds around it and ascends between the trachea and oesophagus to reach the larynx above. Above, from the upper surface of the aorta, are given off the innominate, left carotid, and left subclavian arteries. The left innominate vein crosses above its upper edge to unite with the right innominate to form the superior cava. Below is the left bronchus coming off from the bifurcation of the trachea, and winding around the arch is the left recurrent laryngeal nerve. Beneath the arch and in front of the bronchi are the right and left pulmonary arteries. From the latter the ductus arteriosus goes to the arch. The cardi^-c branches of the pneumogastric and sympathetic nerves lie on the anterior, inferior, and posterior sides of the arch. The ductus arteriosus at birth is about i cm. long and runs from the pulmonary artery to the arch of the aorta below the left subclavian artery. It serves in the foetus to carry the blood from the trunk of the pulmonary artery direct to the aorta instead of passing into the lungs. When, after birth, the lungs are used the ductus arteriosus becomes obliterated and is found later in life as a cord running to the under side of the arch of the aorta. Congenital defects in the heart are a frequent cause of death at birth and in infancy and childhood. They cause an undue mixture of the venous and arterial blood and give the surface a dusky, bluish hue, hence the term ' ' blue baby ' ' as applied to this condition. It is due to an absence of a part or the whole of the septa between the atria and ventricles; to a patulous condition of the foramen ovale of the right atrium ; and also to a persistent patulous condition of the ductus arteriosus. Children so aftected, if they outlive infancy, usually die before reaching adult age. Aneurism. — This portion of the aorta is also a favorite seat of aneurism. The symptoms produced will depend of course on the direction which the tumor takes. If it tends anteriorly it would involve the lungs and pleurae and the phrenic and vagus nerves, also the svmpathetic. The displacement of the left lung would be the more marked. Involvement of the recurrent laryngeal nerve might make a change in the voice, or there might be disturbances of the pupil of the eye due to implication of the sympathetic. Should the tumor enlarge posteriorly the pressure on the trachea would interfere with the breathing. If the tumor is large this pressure would involve the oesophagus and there might be difificultv in swallowing. Compression of the thoracic duct is said to have led to rapid wasting. If the aneurism bulges downward it impinges on the left bronchus, which may lead to its dilation and cause bronchon-htea. A large tumor could also interfere with the flow of blood through the pulmonary arteries and so give rise to congestion and dyspnoea. An enlargement upward would involve the innominate and left carotid and subclavian arteries and also the left innominate \ein. Interference with the arteries and veins of the neck and upper e.xtremity frequently gives rise to changes in the pulse on the affected side and also to xenons congestion or even oedema. Changes in the voice or even its loss also occur. The sac as it passes upward may show itself in the suprasternal notch. In all aneurisms of the arch cough is apt to be a prominent symptom. It is often paroxvsmal. It is to be accounted for by pressure on the trachea or laryngeal nerves. Difiticulty in breathing and swallowing may arise in deep-seated small tumors growing backward and downward. This may be somewhat relieved by sitting up or leaning forward, while reclining or lying on the back may be unendurable. The great amount of distress which these aneurisms of the arch of the aorta may give rise to is readily appreciated when one recalls that there is only a distance of 5 or 6 cm. (2^ in.) between the upper edge of the sternum and the anterior surface of the vertebral column, a space already filled with important structures. The Descending Aorta. — The remaining portion of the aorta, from the lower border of the fourth thoracic vertebra down, is called the descending aorta. It is divided into the thoracic and abdominal portions. The thoracic aorta begins at the lower border of the fourth and ends at the lower border of the twelfth thoracic vertebra. At its beginning it lies on the left side of the vertebral column, but as it descends it comes somewhat forward but does not reach the middle line. It lies in the posterior mediastinum more toward the left side than toward the right. Relations. — In front above are the pericardium, the pulmonary artery, left bronchus, left pulmonary veins, and oesophagus. Behind is the vertebral column. To the j'ight are the oesophagus above, the vena azygos major, and the thoracic duct. To the left are the left lung and the pleura, which it grooves, and a quite small portion of oesophagus below. Aneurism, when involving the thoracic aorta, tends to cause absorption of the vertebrae and ribs, and to present posteriorly; as the space is not so restricted as is the case higher up the tumor has a freer opportunity to expand and the suffering is not so great nor are the symptoms so marked. It may rupture into the left pleura or oesophagus and may erode through the bodies of the vertebrae into the spinal canal. THE OESOPHAGUS. The oesophagus begins at the lower edge of the cricoid cartilage, opposite the lower border of the sixth cervical vertebra, and ends at the cardiac opening of the stomach, opposite the eleventh thoracic vertebra. It is 25 cm. (10 in.) long and begins 15 cm. (6 in.) distant from the teeth. In the neck it inclines to the left, hence oesophagotomy is performed on that side. It reaches the farthest point to the left at the level of the top of the sternum or opposite the second thoracic vertebra. It then inclines to the right, reaching the median line opposite the fifth thoracic vertebra. It then again inclines to the left, to pierce the diaphragm in front of the aortic opening and to the left of the median line opposite the tenth thoracic vertebra, and ends in the cardiac opening of the stomach entirely to the left of the median line and opposite the eleventh thoracic vertebra or tenth dorsal spine. In its passage through the diaphragm it is accompanied by the continuation of the two vagi nerves. At its termination it grooves the posterior surface of the liver. Lumen. — The lumen of the oesophagus is narrowed at three points, Ti) its commencement; (2) where it crosses the aorta and left bronchus; and (3) near its end as it passes through the diaphragm. The average diameter of the lumen is 2 cm., which at the upper and lower constrictions is reduced to 1.5 cm. The middle constriction is not quite so marked. The lower constriction is most marked at the point of the passage of the oesophagus through the diaphragm; it enlarges slightly as it enters the stomach. This part of the oesophagus is quite distensible. The next most distensible part is opposite the left bronchus. This is on a level with the middle of the first piece of the sternum and the third thoracic vertebra. The upper constriction at the cricoid cartilage is the least distensible part of the tube, so that a body passing it may pass entirely down. In both living and dead bodies the lumen of the oesophagus is sometimes open and sometimes closed. In the neck the pressure of the soft parts usually keeps it closed, but frozen sections of the dead body show it sometimes closed and sometimes open. Mikulicz in using the oesophagoscope has found the lumen open in the living patient and been able to see down the remainder of the tube when the instrument has only been passed beyond the second constriction. In passing an oesophageal bougie, one should not be used of a larger diameter than 18 mm. (^ in.). It will enter the oesophagus opposite the lower border of the cricoid cartilage about 15 cm. (6 in.) from the teeth. It will pass the second constriction 7 cm. (2 3/^ in.) farther on, opposite the middle of the first piece of the sternum or 2.5 cm. (i in.) below its upper border, and meet the third constriction 15 cm. (6 in.) lower down, or 37 cm. (14.4 in. ) from the teeth, and enter the stomach 3 cm. below, or 40 cm. (16 inches) from the teeth and opposite the eleventh dorsal vertebra. Relations. — In the neck the oesophagus rests on the longus colli muscle and vertebrae behind and has the trachea in front. On the left side it Ues close to the carotid sheath, the lobe of the thyroid gland, and the thoracic duct. The left recurrent laryngeal nerve is in closer relation to it than the right on account of the latter coming over from the right subclavian artery. The left nerve lies on its anterior surface near the left edge. The right carotid artery lies farther from it than does the left. The left inferior thyroid artery is also in closer relation to it than the right on account of the inclination of the oesojAagus to the left side. its bifurcation in front and the aorta behind. In front it has the bifurcation of the trachea and encroaches more on the left than on the right bronchus. The arch of the aorta and the left carotid and subclavian arteries also pass in front of it and in the posterior mediastinum the pericardium and diaphragm are anterior to it. Laterally it is in relation with the left pleura above and the right below and the vena azygos major runs along its right side posteriorly. The arch of the aorta winds around its left side at the root of the lung. The right vagus nerve runs down posteriorly and the left anteriorlv. forming a plexus on its surface. Dilatation and Diverticula. — In certain rare cases the oesophagus becomes dilated ; this may in\-ol\-e the whole length of the tube or only its lower end. Obstruction low down may be a cause. It has been known to accompany a largely dilated aorta which pressed the oesophagus against the diaphragmatic opening and so hindered the passage of food. Regurgitation of food is a prominent svmptom and liquids may regurgitate from the stomach and even enter the mouth. Di\-erticula are usually acquired and are but seldom congenital. The point of junction with the pharynx just behind the cricoid cartilage is the most frequent seat. A sac is formed which descends posteriorly behind the part of the tube below and as it increases in size it presses forward and may obstruct its lumen. Obstruction from foreign bodies, stricture, or disease of the cardiac end of the stomach may be a cause. \'omiting is a prominent symptom and the vomited material does not show any evidences of digestion or the presence of acid. The existence of a tumor which forms only on deglutition and which can be emptied by pressure f^ -'"f^.- W is said to be pathognomonic of an oesophageal diverticulum. a gastrostomv. Carcinoma and Stricture. — Carcinoma is usually of a flatcelled epitheliomatous type and may surround the oesophagus like a ring. The walls are thickened, a tumor forms, and the internal surface may become ulcerated. Stricture of the affected part may lead to the formation of a dilation or diverticulum above, and ulceration and abscess may perforate and enter surrounding organs. Dyspnoea may arise from pressure on the air-passages and pus may even penetrate them. Hemorrhage is also sometimes a symptom. It may come either from the inside or outside. In the latter case it may come from the large vessels in the neighborhood. and lungs. Foreign Bodies. — Foreign bodies may become imj^acted at any part of its course; this is particularly the case if they are hard and rough with irregular outlines. If they are smooth and soft and more or less rounded thev are apt to lodge at the constricted parts of the tube. These points are, as already stated, at its commencement, where it crosses the aorta and left bronchus, and where it passes through the diaphragm. The upper constriction is 1.5 cm. (or f in. ) in diameter, and is least distensible. It will dilate to the width of 2 cm. , and thus will allow a body of about 3/^ inch diameter to pass. The two lower constrictions are more distensible and a body that passes the oesophagus can usually pass the ileocaecal valve, so that the upper end of the oesophagus acts as a gauge to pre\ent the entrance of substances too large for the rest of the alimentary tract. The bodies which become lodged are usually those which have been pushed down beyond the opening of the oesophagus by the contraction of the muscles of the pharynx, and then on account of their irregular form become caught by the contraction of the tube below. With the head moderately extended, the first constriction will be 15 cm. (6 in.) from the teeth. A foreign body at this point will be opposite the cricoid cartilage at the level of the sixth cervical vertebra. The second constriction is opposite the middle of the first piece of the sternum. This is 7 cm. (2^ in. ) below the cricoid cartilage. Therefore a foreign body lodged just above it would be just below the top of the sternum. distensible than the two above it. Maurice H. Richardson was able, after introducing the hand mto the stomach, to put two fingers into the cardiac opening from below, and so dislodge some impacted false teeth. Foreign bodies are dangerous on account of the ulceration into the various organs which they cause and also on account of pressure. Pressure on the left bronchus and trachea has caused suffocation. Ulceration may cause fatal hemorrhage by involving the carotid arteries, more likely the left, the inferior thyroids, the innominate, and even the aorta itself lower down. Low down in the chest the pericardium is in front of the oesophagus, and has been perforated. On the left side above and the right side below, the pleurae have been perforated and the lungs involved. Abscesses may occur from the ulcerative process and they are particularly dangerous, as the distance between the upper portion of the sternum and anterior portion of the bodies of the vertebrae is so small that compression of the air-passages and suffocation is readily produced. THE THORACIC DUCT. The thoracic duct carries not only lymph but also r//)'/<^ which is emptied into the venous system and goes to nourish the body. Therefore a wound of the duct with the escape of its fluid may result fatally from inanition. The lymph coming from all parts of the body is collected into two ducts, the right lymphatic duct and the thoracic duct. Of these two the right lymphatic died is the smaller. It collects the lymph coming from the right side of the head and neck, right upper extremity, right side of the thorax and the upper convex surface of the liver. The several lymphatic branches unite to form a duct, one to two centimetres long, which empties into the venous system at the junction of the right internal jugular and subclavian veins. At its point of entrance it is guarded by a pair of valves. As this duct contains no chyle, and lymph of only a portion of the body, wounds of it have not proved serious. The cisterna or receptaculum is 5 to 7.5 cm. long and 7 mm. wide. It receives not only the lymph from the parts below but also the chyle from the intestines. It passes through the aortic opening in the diaphragm with the aorta to the left and the vena azygos major to the right. In the posterior mediastinum it lies on the bodies of the seven lower thoracic vertebrae, with the pericardium, the oesophagus, and the arch of the aorta in front. The thoracic aorta is to its left and the vena azygos major and right pleura to its right. Above the fifth thoracic vertebra it ascends between the oesophagus and left pleura, behind the first portion of the left subclavian artery. On reaching the level of the seventh cervical vertebra it curves downward over the left pleura, subclavian artery, scalenus anticus muscle, and vertebral vein to empty at the junction of the internal jugular and left subclavian veins. It passes behind left internal jugular vein and common carotid artery. At its termination it lies just external to the left sternoclavicular joint and just below the level .of the upper border of the clavicle. A punctured wound at this point would injure the duct. Accompanying the veins of the neck are numerous lymph-nodes which not infrequently become enlarged and require removal. It is in operating on these nodes that wounds of the thoracic duct have been most often produced. When divided, its lumen has appeared to be of the size of a "knitting needle." In some instances the thin walls of the duct have been ligated. In other cases of injury either the oozing point has been clamped with a haemostatic forceps which has been left in position for a day, or else the wound has been packed with gauze. Recovery usually ensues. skeleton and the appendicular skeleton. The axial skeleton embraces the bones of the head, the spine, the ribs, the hyoid bone, and the breast bone. In the spine are included not only the vertebrae of the cervical, thoracic, and lumbar regions, but likewise the sacrvmi and coccyx. ity in man is an organ of prehension. As such, mobility is its chief characteristic. To permit of this mobility the bones and joints are many, and the latter are comparatively loose; the muscles, also, are both numerous and complex. Hence it is that slight injuries are frequently followed by considerable disturbance of function. They are readily produced and with difficulty repaired, either by nature or by art. Orthopaedic surgery has done much for the disabilities and deformities of the lower extremities, but comparatively little for those of the upper. An artificial leg in many cases satisfactorily substitutes the natural one, but an artificial arm is comparatively useless. The hand is the essential part of the upper extremity, and the rest of the limb is subsidiary. If the forearm were lacking and the hand were attached to the end of the humerus it would still be a very useful appendage, far more so than the stump which is left after the hand has been amputated. The extremities proper are joined to the trunk by what are called girdles. The upper extremity is attached through the medium of the shoulder-girdle and the lower extremity by the pelvic girdle. The interposition of these girdles adds to the mobility of the extremities, and as the upper extremity is more mobile than th j lower we find the shoulder-girdle composed of two bones instead of one as in the pelvic girdle ; also, as the lower extremity bears the weight of the body it requires strength in addition to mobility, hence we find that it is joined to the trunk by a single big strong bone, the innominate, instead of by two comparatively slight, narrow bones like the clavicle and scapula which form the shoulder-girdle. The extremities are termed appendicular because and^runrfo;;;Tn^^hTax°aVstie?on ^^ey are simply appendages to the essential part, and those of the upper and lower ex- which is the head and trunk: a person can live with- The upper extremity is joined to the trunk by the shoulder- girdle, which is composed of the clavicle and scapula. The main movements are anteroposterior, as in swinging the arm, those of abduction and adduction, as in raising and lowering it sidewise, and rotation. teres minor and major, and subscapularis muscles. The clavicle is developed mainly from membrane, partly probably from cartilage, and is the first bone in the body to ossify. It keeps the shoulder out away from the body and increases the range of motion of the upper extremity. It owes its existence to the function of abduction. Without a clavicle abduction is practically wanting and when in man the clavicle is broken, he is temporarily reduced to the condition of those animals which have no clavicles; he is able to move the arm backward and forward but not to elevate it properly, and this is an important diagnostic symptom of that injury. The clavicle is lacking in the ungulates or hoofed animals. These have an anteroposterior movement, but little abduction. A horse or cow moves its fore-legs back and forward, but not out away from the body. Hence its helplessness v.hen these movements are essential. It is also lacking in seals and whales. In the carnivora, as the lion and the tiger, which possess rudimentary clavicles, sufficient adducting power is present to enable them to hold their food while tearing it apart. In man, apes, bats, rodents, and insectivora the clavicle exists as a well-formed bone; hence they can raise the arm well out from the body and even higher than the shoulder. In the rodents, as the squirrel, they are enabled to hold a nut firmly in the paws while eating it. When, as in some of the lower orders, the function of abduction is all important, we find not only the clavicles present and, as in the common fowl, joined, forming the "wish-bone," but in addition, in birds, there is a precoracoid bone formed by the coracoid process, which is enlarged and continued forward to articulate with the sternum; thus in fiying animals there are practically two clavicles on each side. by the bones, these receive the principal injuries and they are often broken. Fractures of the clavicle dispute with those of the radius the distinction of being the most numerous. Contusions produce more or less complete paralysis of the muscles, not infrequently through lesions of the nerves. The laxity of the joint favors the dislocations to which it is so frequently subject. It likewise becomes the seat of tuberculous disease requiring resection. Crushes of the arm sometimes require its removal at the shoulder-joint, and occasionally as the result of injury or disease operations may be required on the axillary lymph-nodes, nerves, or blood-vessels. In order to determine the character and extent of injuries to the shoulder, its surface anatomy must be thoroughly known. In order to treat them, a knowledge of the deeper structures and their relation to one another is essential. the humerus. The clavicle is a comparativelv long and slender bone that acts as a prop to keep the point of the shoulder out from the trunk. The inner extremity is large and rests with its flat surface on the upper outer edge of the sternum, with the interposition of a disk of hbrocartilage. Its outer extremity is tiattened ; it articulates by means of a gliding joint with the acromion process of the scapula, and it is connected with the base of the coracoid process beneath by ligaments. It is double cun.-ed, the large curve having its convexity forward and embracing the inner two-thirds of the bone, and the small curve having its concavity forward, forming the outer third. At the deepest part of the concavity of the anterior edge, about at the junction of its outer and middle thirds, is a small rough eminence called the deltoid tubercle because of the attachment to it of the deltoid muscle. At a corresponding point on the posterior and under surface of the bone is a prominent projection called the conoid ti{bercle ; to this is attached the conoid ligament. Running for\\-ard and outward from this tubercle on the under surface is a rough line which ser^'es as the point of relation to the fractures of this bone. The middle third of the bone is its weakest part. Attached to the clavicle on its anterior surface are the deltoid muscle on its outer third and the pectoralis major on its inner half. On its posterior and upper surfaces are the trapezius at its outer third, and the clavicular head of the sternomastoid on its inner third. The subclavius muscle is attached to its under surface. It will thus be seen that there is a space equal to one-sixth of the length of the bone inferiorly and one-third of the bone superiorly which is free from muscular attachments, and it is here that it is most frequently fractured. The Scapula. — The scapula is spoken of as having a body, neck, spine, and acromion, glenoid, and coracoid processes; an upper, an anterior, and a posterior border; and an upper and a lower angle. It is not often spoken of as possessing a head, the glenoid process or that portion being sometimes so called in which the glenoid cavity or fossa for the articulation of the humerus is situated. The constriction surrounding the head of the scapula is known as the anatomical neck, in contradistinction to the surgical 7ieck, which name has been gi\en to that portion indicated by a Hne drawn through the suprascapular notch and passing beneath the spine and to the inside of the attachment of the long head of the triceps muscle just below the lower edge of the glenoid cavity. The body of the scapula on its under surface is flat and rests on the thorax from the second to the seventh and nearly to the eighth rib. Its movements on the chest are free and follow those of the arm. It rises and falls, glides forward and backward, and also rotates on an anteroposterior a.xis. When using any portion of the scapula as a landmark it is customar)- to have the arm hanging by the side: if it is otherwise the position of the bone will be changed, and the relations of its projections to the surrounding parts are altered. The scapula is sometimes fractured directly across its body below the spine. One should endeavor to fi.x in mind especiallv the relation of the acromion and coracoid processes to the head, with its glenoid cavity, and the rest of the bone. The head is comparati\-ely small and cup-shaped, with the glenoid fossa on its surface for the head of the humerus. It is joined to the body of the bone by a narrow constricdon called the neck. Fractures through this neck are rare. Above and posterior to the glenoid fossa is the acromion process and spine of the scapula, and above and anterior is the coracoid process. The spine of the scapula runs upward and forward across the upper and posterioi surface of the bone. Its commencement at the posterior edge of the bone is called its root; this is over the fourth rib and opposite the third thoracic spine. The posterior edge of the scapula opposite the root of the spine projects backward, but this is not the superior angle, which is still higher up. The spine of the scapula ends anteriorly in the acromion process. This projects far beyond the glenoid cavity, overhangs the head of the humerus, and forms the point of the shoulder. The acromion process is not so often fractured as one would expect. It articulates with the clavicle and the bones are not infrequently luxated at this point. The coracoid process projects forward underneath the clavicle to the upper and inner side of the head of the humerus. It is about 2.5 cm. (i in.) below the clavicle and just to the outer side of the junction of its middle and outer thirds. It lies just underneath the inner edge of the deltoid muscle, hence it is not always easily felt. It is almost never fractured, but is especially valuable as a landmark in injuries and operations on the shoulder. muscle and is covered by the trapezius which inserts into the spine and thus obscures its outline. The inferior angle is crossed by the upper edge of the medium of the anatomical neck. The head projects in^^■ardly from the shaft at an angle of 1 20 degrees to it. The lesser tuberosity has inserted into it the subscap2ilaris muscle; it presents forward. To its outer side and separating it from the greater tuberosity is the bicipital groove for the long tendon of the biceps muscle. To the outer side of the groove is the greater tuberosity with its three facets for the supraspinatus, infraspinatus, and teres minor muscles. The greater tuberosity projects considerably beyond the acromion process and therefore forms the most prominent part of the shoulder. Immediately below the tuberosities is the surgical neck. It is described as being the portion between the tuberosities above and the insertions of the pectoralis major and latissimus dorsi muscles below. It is a common site for fractures. Half way down the shaft on its outer side is the rough deltoid eminence for the insertion of the deltoid muscle. f) Sternoclavicular Joint. — The ligaments uniting the inner end of the clavicle to the thorax at the upper end of the sternum are the intorlavicular, which passes from one clavicle to the other across the top of the sternum, the anterior 3.x\d posterior sternoclavicular, and the rhomboid or costoclavicular ligament which passes from the clavicle downward and forward to the first rib. ' This last one limits displacement in cases of luxation. There is a fibrocartilaginous disk between the clavicle and sternum, forming two distinct joint cavities. The line of the joint slopes downward and outward. Acromioclavicular Joint. — The outer end of the clavicle articulates with the acromion process by a joint whose surface inclines down and inward, thus favoring displacements of the clavicle upward. The ligaments joining them are called the superior and inferior acromioclavicular. In reality they are simjjly the thickened portions of the capsular ligament. This capsular ligament is ruptured in the not infrequent cases of lu.xation which occur here. Running from the under surface of the clavicle, a short distance from its outer end, to the coracoid process below, is the deformity to which attention will be called in describing the fractures of the clavicle. From the coracoid process the coraco-acromial ligament runs outward and upward to the acromion process, the coracohumeral outward and downward to the neck of the humerus, and the costocoracoid ligament inward to the first rib at its cartilage. (> The Shoulder-joint.— The upper extremity being an organ of prehension and not of support, the shoulder-joint, which is the articulation which connects it with the trunk through the shoulder-girdle, is constructed with the idea in view of favoring and permitting motion, and not of supporting weight or resisting force. Hence we find it to be a ball-and-socket joint, the one which allows of the freest movements. The glenoid cavity is a shallow excavation, not a deep cup, as in the hip. The articulating surface of the head of the humerus is extensive but not so large as it would have been had the scapula not been made to move on the thorax. The clavicle keeps the joint well out from the side of the body; hence the neck of the humerus is short. The movements of the arm are so extensive and free that we do not have the tuberosities of the humerus so large and set so far away from the articular surface as is the case with the femur and its trochanters. If the upper portion of the femur was like the upper end of the humerus, the lower extremity would be continually rolling in or out, making walking or running at least difificult if not impossible. Thus we see that the shape of the bones is dependent on the character of their functions. The ligaments of the joints are inelastic tissues; hence those that enter into the construction 01 a movable joint must be loose, and the more movable a joint is the more does its security depend not on its ligaments, but on its muscles. The shoulder-joint, like other joints, has a capsular ligament which is attached to the adjacent bones and serves to keep the lubricating synovial fluid applied to the articulating surfaces. In certain positions this ligament may also serve to a limited extent to keep the ends of the bones of the joint in contact. to those on the other. The muscles and their tendons pass across the capsule and sometimes blend with it, so that there is an intimate relation between the muscles and their tendons and the hgaments; finally, there is a third structure called the glenoid ligament, which is in reality a fibrocartilage that serves to deepen the glenoid cavity. The capsidai' ligament is attached on one side to the edge of the glenoid cavitv the anatomical neck of the scapula, and the rim of the glenoid ligament. On the other side it is attached above or externally to the anatomical neck of the humerus just at the edge of the articulating surface, but on the lower or inner surface it is attached some distance below the articular surface (approximately i cm.) and then turns upward toward the edge of the articular cartilage. Thus a fracture through the anatomical neck might pass outside of the joint above, and inside of it below. The positions assumed by the capsule in abduction and adduction are sho^ra in Figs. 237 and 238. The capsular ligament, per se, has not much strength. There are two openings in it — one is for the long tendon of the biceps and the other is the opening of the bursa beneath the subscapularis muscle. Sometimes there is a synovial extension beneath the supraspinatus tendon and rarely, in old people, a communication with the subacromial bursa. It is evident that in case of suppuration within the joint the pus would tend to find ^•ent first through these openings. Fig. 239. — View of the left scapula and outer end of the cla\'icle from in front, shoT^dng the ligaments passfrom the coracoid process to the clavicle and acromion process, the glenoid ligament, and attachments of the I heads of the biceps and triceps muscles. cles are paralyzed the weight of the arm causes the head to fall away and a depression is seen beneath the acromion process. The capsule is strengthened b}- two definite and separate ligamentous bands called the coracohumeral and the glenohumeral ligaments. The coracoJuimeral ligament passes from the root of the coracoid process to the anterior portion of the greater tuberosity. It is supposed by Sutton to be a regression of the tendon of the pectoralis minor muscle. the tendon of the subclavius muscle and homologous with the ligamentum teres in the hip. It is also called the superior glenohumeral ligament, in contradistinction to some bands on the lower anterior part of the capsule which are called by some anatomists the middle and inferior glenohumeral ligaments. Between the superior above and the middle and inferior below is the opening by which the bursa of the subscapularis muscle communicates with the joint. The glenoid ligament is the wedge- or cup-shaped ring of fibrocartilage which deepens the glenoid fossa. It is attached around its edge to the rim of the fossa and at its upper end receives the long tendon of the biceps, which divides and blends with it on each side. At its lower part when it is attached to the bone it blends with the anterior edge of the long tendon of the triceps. comprising the remainder of the clavicle and all of the scapula and bearing the weight of the whole upper extremity, hangs from and is supported and moved by the^muscles which pass from it to the \'ertebree posteriorly and to the skull, hyoid bone, and ribs anteriorly. Antcriorlv the clavicle has attached to its upper inner third the clavicular origm of the sternomastoid muscle; and on its under surface is the subclavius muscle, which arises from the cartilage and anterior end of the first rib. These muscles aid in moving the clavicle. Running from the third, fourth, and fifth ribs to the coracoid process is the pectoralis minor imiscle ; and on the side of the chest, passing to the posterior edge of the scapula, is the serrahis anterior {niagJins) muscle. It will be alluded to again. levator scapulce, and the two rhomboid muscles. The trapezius arises from the superior curved line of the occiput, the ligamentum nuchae, and the spines of the seven cervical and all of the thoracic vertebrae. It inserts into the upper surface of the outer third of the clavicle, acromion process, and spine of the scapula to near its root. Its upper fibres directly aid in sustaining the weight of the upper extremity. It is not infrequently paralyzed, and then falling of the shoulder is marked. It also tends to pull the scapula backward toward the spine, and rotates it. The levator scapulae arises from the transverse processes of the upper four cervical vertebrae and passes downward to insert into the posterior edge of the scapula between its upper angle and the root of the spine of the scapula. The scapula is supported largely by this muscle; hence when the trapezius is paralyzed, as occurs in division of its motor nerve, the spinal accessory, this muscle is utilized in counteracting its loss. The rhomboid muscles arise from the low^er part of the ligamentum nuchae and the spines of the seventh cervical and upper five thoracic vertebrae and insert into the posterior edge of the lower three-fourths of the scapula. The serratus anterior (magnus) muscle (Fig. 202), lies beneath the scapula and arises from nine slips from the outer surface of the upper eight or nine ribs; the second rib receives two slips. It passes backward and upward and inserts into the posterior edge of the scapula from its upper to its lower angle. on the side of the chest. The omohyoid muscle arises posteriorly from the upper border of the scapula, just behind the suprascapular notch, and then runs upward and forward to the under surface of the body of the hyoid bone. It is a digastric or two-bellied muscle and its middle tendon is attached by a pulley-like process of the deep cervical fascia to the first rib. While the muscles above enum.erated comprise all those directly attached to the shoulder-girdle and trunk, they are of course assisted to some extent by the muscles forming the axillary folds, viz., the pectoralis major anteriorly and the latissimus dorsi and teres major posteriorly. The shoulder-girdle is elevated by the upper fibres of the trapezius, levator scapulae, rhomboidei, sternomastoid (clavicular origin), and omohyoid. It is depressed by the lower fibres of the trapezius, latissimus dorsi, lower fibres of the serratus anterior (magnus), pectoralis major, pectoralis minor, and subclavius. It is drawn forward by the pectoralis major, minor, subclavius, serratus anterior, omohyoid, and, if the arm is fixed, by the teres major muscles. It is drawn back by the trapezius, rhomboidei, and latissimus dorsi muscles. Circumduction is eft'ected by a combined action of various parts of these muscles. from the trunk, so that the arm hangs free. It has as its framework three bones the clavicle and scapula above, forming the shoulder-girdle, and the humerus below. They radiate from the region of the joint, the clavicle toward the front, the scapula toward the back, and the humerus downward, forming the basis of the shape of the shoulder, which is modified by the muscles, fat, and skin. The skin and fat bridge over and tend to obliterate the hollows and to a less extent obscure the prominences. This is more the case as applied to the muscles than the bones, hence the bones form the better landmarks or guides. In children the bones are but slighdy developed and their prominences not marked. Fat is usually abundant and it is often no easy task to recognize by the sense of touch the various anatomical parts and determine whether or not they have been injured. For this reason one should endeavor to increase his skill by taking advantage of every opportunity that offers for examination. In the case of women the same thing usually exists, but to a less degree. In the somewhat emaciated adult male the structures can be recognized to best ad\'antage. Its large, knob-like inner extremity projects considerably above the upper edge of the sternum, which can be felt at the suprasternal notch. Take particular notice of its size and compare it with the one on the opposite side so as not to be misled as to its being diseased or luxated. Follow the bone to its outer extremity, which is higher than the inner, more so when lying down than when standing. A prominent ridge marks its outer extremity ; if it is difificult to recognize, as will often be the case, then continue directly outward to the point of the shoulder, which is formed by the tip of the acromion process. Having recognized this point, the end of the clavicle will be found about 2.5 to 3 cm. ( i to i^in.) directly inward from it. In the median line above the sternum is the suprasternal notch with the prominent sternal origins of the sternomastoid muscles on each side. Just to the outer edge of these tendons lie the sternoclavicular joints. The one on the right side marks the ending of the innominate artery and the commencement of the right common carotid and subclavian. That on the left marks the left carotid with the subclavian directly to its outer side and a little posteriorly. The inner two-thirds of the clavicle is convex forward. Above this portion is the subclavian triangle in the supraclavicular fossa. The oute}- third of the clavicle is convex backward and from its upper surface the trapezius muscle can be felt proceeding upward. This leaves the middle third of the bone free from muscle. Under the middle of the bone passes the subclavian artery. It cur\-es upward about 2. 5 cm. ( i in. ) above the clavicle to descend again to the sternoclavicular joint. The arch so formed indicates the apex of the lung because the subclavian artery rests on the pleura. The internal jugular vein passes down opposite the interval between the sternal and clavicular heads of the sternomastoid muscle. Just above the clavicle, a little internal to its middle, and behind the clavicular origin of the sternomastoid muscle is seen the external jugular vein. It terminates in the subclavian vein, which lies to the inner (anterior) side of the artery. To the outer side of the artery the cords of the brachial plexus pass upward and inward. They become prominent in emaciated subjects when the head is turned forcibly toward the opposite side. The posterior belly of the omohyoid muscle varies much in its position, sometimes it lies behind the clavicle, at others two or three centimetres above it. Immediately below the clavicle is the infracla\'icular fossa. At its inner extremity can be felt the first rib. As it is exceedingly easy to mistake the ribs, it is best, in counting them, to locate the second rib by recognizing the angle of the sternum, (angle of Ludwig) to which it is opposite, on the surface of the sternum about 5 cm. (2 in.) below its upper edge. Attached to the lower edge of the inner half of the clavicle is the pectoralis major muscle and to the outer third the deltoid muscle. This leaves one sixth of the lower edge of the clavicle free from muscular attachments. This forms the base of the subcla\-icular triangle and its two sides are formed by the adjacent edges of the pectoralis major and deltoid muscles. Beneath this triangle runs the first portion of the axillary artery with the vein to its inner side and the cords of the brachial plexus to its outer side. Deep pressure at this point can compress it against the second rib, but not so effectively as above the clavicle. Just to the outer side of the junction of the middle and outer thirds of the clavicle, in front of the deepest part of the concavity of the clavicle and about 2. 5 cm. ( I in. ) below it, is the coracoid process. It is better felt by pressing the fingers flat on the surface than by digging them in. It is somewhat obscured by the edge of the deltoid muscle, which covers it. Running from the coracoid to the acromion process is the sharp edge of the coraco-acromial ligament. An incision midway between the two processes would open the joint and strike the long biceps tendon as it winds over the head of the humerus to reach the upper edge of the glenoid cavity. Beneath the acromion process is felt the greater tuberosity of the humerus. If the arm is placed alongside of the body with the palm facing forward, a distinct groove can be felt to the inner side of the acromion process passing downward on a line with the middle of the arm. It is the bicipital groove for the long tendon of the biceps muscle. The bony process of the humerus to its outer side is the greater tuberosity and that to its inner side, between it and the coracoid process, on a slightly lower level, is the lesser tuberosity. It will be noted that the greater tuberositv projects beyond the acromion process and forms the prominence of the shoulder. On rotating the arm the tuberosities can be distinctly felt moving under the deltoid muscle. Following the acromion process around toward the back it turns abruptly where it joins the spine of the scapula, forming a distinct angle. This angle is quite prominent, can be readily seen and felt, and can be used as a landmark for measuring the length of the humerus. If the spine of the scapula is followed still farther it ends in its root at the posterior border of the bone opposite the upper edge of the fourth rib and third thoracic spine. This marks the upper extremity of the fissure of the lung; with the arm to the side, the lower angle of the scapula lies over the seventh interspace. Axilla.— On raising the arm directly out from the body the armpit and axillary folds become visible. The rounded edge of the anterior axillary fold is formed by the pectoralis major muscle. It follows the fifth rib and its upper end merges with the lower edge of the deltoid muscle. If firm pressure is made along the inner or lower edge of the outer extremity of the anterior axillary fold the upper end of the biceps muscle can be felt, and lying along with it, to its inner side, is the swell formed by the coracobrachialis muscle. Along the inner edge of the coracobrachialis muscle lies the axillary artery with its vein to the inner side. This is a little anterior to the middle of the axilla. The artery can be felt pulsating along the inner edge of the coracobrachialis and can be compressed by pressure made in an outward and backward direction against the humerus. The line of the axillary artery is from the middle of the clavicle down along the inner edge of the coracobrachialis muscle, which will be anterior to the middle of the axilla. The posterior fold of the axilla is formed by the latissimus dorsi and teres major muscles. By deep pressure in the axilla, posterior to the vessels, the arm being abducted, the rounded head of the humerus can be felt. terior circumflex artery and circumflex nerve. Hence a blow at this point may injure the nerve and cause paralysis of the deltoid muscle. The line of fracture of the surgical neck of the humerus would also lie at this point. DISLOCATIONS OF THE CLAVICLE. Dislocation of the Sternal End of the Clavicle. — The sternal end of the clavicle is most commonly dislocated forward. Other dislocations, which may be upward or backward, are very rare. The range of movement of the clavicle approximates 60 degrees. The bone is lowest when the elbow is brought forward across the front of the body and highest when the arm is raised and placed behind the neck. The luxation is produced by the shoulder being violently depressed and pushed backward, as in falling on it; in some cases an inward thrust may be added. As the clavicle descends its under surface comes into contact with the first rib, which acts as a fulcrum, and the inner extremity is lifted upward and forward, rupturing the sternocla\^icular ligaments. The rhomboid ligament remaining intact prevents a wider displacement of the bone. As regards treatment, to reduce the luxation the shoulder should be elevated and drawn outward and backward. While pressure is made on the protruding bone the arm is used as a lever and the bone tilted into place. Usually reduction can be readily accomplished, but most people have found it difficult to retain the parts in fulcrum and the clavicle as a lever. place. The only sure way of doing so is to keep the patient in bed on his back. Stimson, following Velpeau and Malgaigne, advises the application of an anterior figure eight bandage of plaster of Paris; Hamilton says deformity remains after any method of treatment, but that function will be but little impaired. In upward dislocations the case of R. W. Smith has shown that the end of the bone passes behind the sternal origin of the sternomastoid muscle. In backward dislocations pressure on the trachea and oesophagus have caused difficulty in breathing and swallowing; cyanosis due to pressure on the internal jugular vein has been observed in one case. When one recalls the function of the clavicle in keeping the shoulder out from the body, it is readily seen that when the security of its inner attachment has once been destroyed displacement is favored by the weight of the upper extremity as well as by the action of all the muscles which pass from the head, neck, and trunk to the shoulder-girdle and humerus. In these dislocations of the sternal end of the clavicle the fibrocartilaginous disk of the joint sometimes is carried out with the clavicle and sometimes remains attached to the sternum, more often it follows the clavicle. back of the shoulder driving the acromion down and inward. The clavicle not only Fig. 244. — Luxation of the outer end of the clavicle upward, showing the coracoid process acting as a fulcrum. As the outer end of the clavicle rises, the lower angle of the scapula is carried toward the median line and the acromion process is depressed and torn loose from the clavicle above. rises but also goes backward, or the scapula comes forward, so that the end of the clavicle may rest on the acromion process. In this dislocation the base of the coracoid process, on which the clavicle rests and to which it is bound by the conoid and trapezoid ligaments, acts as a fulcrum. The scapula rotates on an anteroposterior axis, passing through the base of the coracoid process, and as the inner portion of the bone rises, its outer portion, — that is, the acromion process, — descends and is torn from the outer end of the clavicle. The deformity produced by the upwardly projecting end of the clavicle is typical. The luxation may be complete or incomplete. When incomplete the injury is confined to the acromioclavicular joint; when complete the conoid and trapezoid ligaments are partially or wholly ruptured. The joint usually possesses a poorly developed fibrocartilage and inclines upward and outward so that the inclination favors the rise of the clavicle. When the conoid and trapezoid ligaments are not ruptured they serve as the axis on which the scapula rotates forward so that the outer end of the clavicle slips backward on the acromion process. This led Hamilton to describe these luxations as backward luxations. In rare instances the end of the clavicle seems to be displaced posteriorly without rising above its normal level. We reported one such case in the Annals of Surgery several years ago. Reduction of the displacement is easily effected, but the same difBculty in keeping the bone in place has been experienced in this dislocation as in dislocations of the inner extremity. Bandages going over the shoulder and down the arm and under the elbow are commonly employed. The only sure way of keeping the clavicle in its proper position is to operate and fasten it to the acromion with wire or chromicised catgut. W^hen the patient is put in bed the bones are readily replaced. Doiumuard dislocation though rare does seem to ha\'e sometimes occurred. From the fact of the under surface of the clavicle resting almost or quite on the coracoid process it is difilicult to see how it is possible for this injury to take place. It must take place while the scapula is violently twisted on the clavicle. The displacement is readily reduced and shows but little tendency to recurrence. The dislocations of the shoulder are to be studied from the anatomical and not from the clinical standpoint. A knowledge of the anatomical construction of the various parts involved is to be applied to the explanation and elucidation of the methods of production, the signs and symptoms obser\'ed, and the procedures necessary for reduction. edge of the glenoid cavity. Posterior Dislocation. — A posterior luxation is one in which the head goes posterior to the glenoid cavity and usually rests beneath, the spinous process of the scapula, hence this is called subspinous dislocation. ANTERIOR DISLOCATION OF THE SHOULDER. The head of the bone almost always comes out through the anterior portion of the capsule and slips beneath the coracoid process. From this point it may shift its position either a little farther inward, when it is called a subclavicular luxation, or a little farther downward and outward, when it receives the name of subglenoid. As a matter of fact the head usually comes to rest beneath the coracoid process and permanent fixation of the bone either in the subclavicular or subglenoid positions is very rare. As the symptoms and methods of treatment are identical they will all be included under the one head of subcoracoid luxations. What are commonly regarded as subglenoid luxations are really subcoracoid. Method of Production of A^iterior Luxations. — Anterior luxations are produced by the arm being hyperabducted, rotated outward, and the head of the bone pushed or pulled in toward the body. Rotation may not be essential, but it is largely responsible for the wide detachment of the capsule which is present in these injuries. When the arm is raised from the body much beyond a right angle the greater tuberosity strikes the acromion process. If the hyperabduction is continued the acromion process acts as a fulcrum and the head of the bone is lifted from its socket, tearing away the capsule of the joint in front of and below the glenoid cavity. acromion process as a fulcrum the head is levered out of the socket. If now the arm rotates, the capsule is still farther detached and if the force continues to act, as in those cases in which a person is thrown forward and alights on the outstretched arm, or if the axillary muscles contract, the head is thrust from its socket. After once leaving the socket, subsequent movements may cause the head to assume various positions around the glenoid cavity; as a matter of fact it is almost always below the coracoid process. Parts Injured. — When the luxation occurs the arm is hyperabducted and, owing to the acromion process being somewhat posterior to the glenoid cavity, pointing backward, this places it up almost or quite alongside of the head. The force which thrusts the bone out acts downward toward the axilla and inward toward the body. The posterior border of the scapula is prevented from descending by the levator scapulae and rhomboid muscles, hence it is the joint which descends and tears loose the capsule already stretched tighdy over the head of the humerus. tudinally acting force that does it. When the transverse force acts it is expended on the anterior portion of the joint because the joint is at the anterior portion of the scapula. Posterior to the joint the scapula rests on the chest, so it is its anterior portion which is forced inward, thus rupturing the capsule at this point. The fulcrum, or acromion process, is also posterior to the midline of the joint. By a combination of these two forces (longitudinal and transverse) the capsule is ruptured at its lower and especially its anterior portion. Its tearing is favored by a twisting or external rotation of the humerus. The attachment of the capsule is torn from the rim of the glenoid cavity, not from the humerus, and a fragment of the bony rim frequently comes with it. The opening is large and embraces nearly or Fig. 246. — Surface view: subcoracoid dislocation of the humerus, showing the elevation of the shoulder. abduction of the arm, prominence of the displaced head below the coracoid process, flattening of the shoulder, and tense fibres of the deltoid muscle. quite half the circumference of the joint. It is limited above by the coracoid process. The coracohumeral and superior glenohumeral ligaments lying in front of the long tendon of the biceps also limit the tear upwards. If the tear does not e.xtend so high it is because the subscapularis muscle, instead of being torn, is wedged in between the head and the coracoid process. Below, the tear is limited by the insertion of the long head of the triceps. As the head luxates it cannot pierce the triceps tendon, so it slips behind it in a posterior luxation and in front of it in an anterior luxation. Signs and Symptoms. There is (i) at first elevation then lowering of the shoulder, (2) flattening of the deltoid muscle, (3) projection of the elbow away from the side. (4) The norrnal hollow below the outer third of the clavicle is filled up; the head, covered by the deltoid, may sometimes even make a rounded prominence at this point which can frequently be felt. (5) If the elbow is raised and the hand placed on the opposite shoulder and held there the elbow cannot be brought flat on the chest (Dugas's sign), (6) with the arm to the side the distance from the acromion process to the external condyle is increased, with the arm abducted to a right-angle, the same distance is decreased as compared with the previous position as well as when compared with the arm of the opposite side (see Fig. 248). it from forcing the head upward in its displaced position. 2. Flattening of the shoulder is due to the head and tuberosities being displaced inward, thus leaving the socket empty. A marked depression can be felt with the fingers below the prominent acromion process. 3. Projection of the elbow from the side is due to tension of the deltoid muscle because the head is lower than normal. In its natural position the top of the head is about level with the coracoid process; when luxated it is below it. where the head lies. It may form a distinct prominence and when the arm is rotated Fig. 248. — Subcoracoid dislocation of the shoulder. The head of the humerus has slipped off its pedestal or shoulder-girdle onto the side of the thorax. This shows how the arm is shortened and why it is necessary to make traction in order to replace the humerus up again on the shoulder-girdle. form a prominence. 5. In Dugas's test the elbow cannot be brought to the chest because the outer end of the humerus is held close to the chest-wall. On account of the thorax being rounded like a barrel it is necessary for the outer end of the bone to rise as the inner end falls. Treatment. Reduction of an anterior luxation of the shoulder can be accomplished in two ways, viz. , the direct, in which the head is pulled or pushed back into the socket, and the indirect, in which it is levered back. Direct Method. — This consists in first placing the arm in approximately the position it occupied when luxated (abduction) and then pulling or pushing the head toward and into the socket while the arm is rotated to relax the capsule and allow the head to enter. The usual obstacle to reduction of a recent luxation is muscular contraction. The main muscles acting are the deltoid, pectoralis major, latissimus dorsi, and teres major. To effect reduction the action of these muscles must either be held in abeyance or overcome by force. This may be accomplished in several ways, viz. , by the use of general anaesthesia, by such gentle manipulations as will not incite the muscles to contraction, by a quick movement accomplishing the object before the muscles are able to contract, or, finally, by overcoming the muscular action by steady continuous traction. General anaesthesia is the surest way of obviating muscular contraction. The question of muscular contraction having been solved by one or more of these expedients the actual replacement is to be accomplished by dragging or pushing the head back over the route it took in coming out. The opening in the capsule is below and anterior, therefore the arm is to be strongly abducted, and traction made upward and backward. This drags the head upward and backward over the rim of the glenoid cavity into its socket. If it does not enter readily it is because of tension of the untorn part of the capsule; this is to be remedied by gently rotating the arm, when the proper position will be revealed by the slipping of the head into place. Rotation in either direction beyond the proper point narrows the tear in the capsule and keeps the head from entering. Traction is necessary in order to replace the head of the humerus on its pedestal or shoulder-girdle from which it has fallen onto the side of the chest (see Figs. 248 and 250). If it is desired "to tire the muscles out, the plan of Stimson is best. Place the patient in a canvas hammock and allow the arm to hang downward through a hole in the can\'as. Fasten a ten-pound weight to the wrist and inside of six minutes the weight will have dragged the head of the humerus into place. This same object can' be carried out, but not so well, by having the patient lie on the floor and pulling the arm directly upward by means of a rope and pulley. Here the weight of the body acts as the counter force. Other means, such as the heel in the axilla, etc. , may be found described in works on surgery, but it is to be remembered that the objects to be sought are (i) to overcome the action of the deltoid by abducthig the arm, (2) to overcome the axillary muscles — pectoralis major, latissimus dorsi, and teres major — by traction, and (3) to loosen the capsule and open the tear to its widest extent by rotation while the head is pushed with the hand toward and over the lower and anterior edge of the socket. Fig. 250. — Diagram to show how rotation influences the size of the rent in the capsule. The square represents the rent in the capsule and the circle the head of the humerus. If the humerus is rotated too much in the direction of the arrows, either to the right or left, the opening in the capsule is so narrowed as to obstruct the passage of the head. Indirect Method. — The indirect or lever method has been best systematized by Kocher of Berne, although Henry H. Smith, a former professor of surgery in the University of Pennsylvania, taught a similar method previously (see H. H. Smith's "Surgery," 11 vols., also Packard's " Minor Surgery," p. 204, and Ashhurst's "Surgery," 2d Ed., Phila. 1878, p. 284). Kocher's method is as follows: First Step. — Flex the forearm until it forms a right angle with the arm, then, with the elbow touching the side of the body, rotate the arm outward 90 degrees until the forearm points directly outward (Fig. 251). This causes the head of the bone to rotate outward and leave the side of the chest to take a position close to the glenoid cavity. Second Step. — The arm being held in this position, the elbow is raised forward until Fio. 251. — Kocher's method of reducing dislocation of the shoulder: First step — Flex the forearm at a right angle to the arm; bring the humerus alongside the chest, the elbow nearly touching the side, and rotate outward as far as the arm will go without undue force. it forms a right angle or a little more with the long axis of the body. This relaxes the coracobrachialis muscle, releases the lesser tuberosity, which may be caught against it, and allows the head to pass outward and ascend from its low position up into the glenoid cavity (Fig. 252). T///rd Step. — Carry the arm obliquely inward, place the hand on the opposite shoulder and bring the elbow down to the surface of the chest, the humerus pointing diagonally downward and inward as in the Velpeau position for fractured clavicle (Fig. 253). The mechanism, as readily demonstrated on the cadaver, is as follows: The head lies to the inner side of the glenoid cavity with the tense posterior portion of the capsule passing backward. When external rotation is made the capsule is wound around the head and upper portion of the neck and the head moves out. In some instances the head will not only move out but will likewise move up and be drawn at once into place. Bringing the arm forward and upward relaxes the coracobrachialis muscle, while bringing it across the chest in the last step assists the head over the rim of the glenoid ca\-ity and restores the member to its normal position. Prof. H. H. Smith brought the elbow forward before making the external rotation instead of after, as did Kocher. This is probably the better way because persistence in rotating outward when the lesser tuberosity is caught beneath the tense coracobrachialis muscle is one cause of the frequent fracture of the humerus in attempting to carry traction or to jamming of the head between the scapula and side of the chest. This method can be used without anaesthesia, but it is at times exceedingly painful and savors of cruelty. It is particularly applicable for old and severe cases. It depends for its efficienc}^ on the integrity of the posterior portion of the capsule, if this has been torn loose the method fails and the head simply rotates in situ. If this latter is the case, reduction can readily be effected by direct traction and manipulation. Posterior dislocations are always beneath some portion of the spine of the scapula, hence they have been called subspinous. When the head lies anteriorly under the posterior portion of the acromion process they have been called subacromial. Posterior luxations are rare. They occur either when the arm is abducted with strong internal rotation or by direct violence, such as a blow on the anterior portion of the shoulder, which forces the head out of its socket backward. The posterior portion of the capsule is torn and the head lies posterior to the glenoid cavity with its anatomical neck resting on the rim and the lesser tuberosity in the glenoid fossa. The arm is inverted and abduction and rotation impaired. The capsule is ruptured by internal rotation while the arm is in a position of abduction, and then a push sends the head posteriorly. We have seen it as a congenital affection resulting from injury in childbirth. and short head of biceps Fig. 254. — Raising the arm to a vertical line or a little more relaxes the tendon of the coracobrachialis and short head of the biceps muscle and allows the lesser tuberosity of the humerus to pass beneath it when the arm is rotated inward to place the hand on the opposite shoulder. The infraspinatus, teres minor, and sometimes the subscapularis muscles are ruptured and frequently there are accompanying fractures of the tuberosities or some part of the scapula. The head makes a prominence posteriorly and the arm hangs to the side and in a position of inward rotation. Reduction, if the injury is recent, is Hkely to be easily effected by pushing the head directly forward into its socket. in its inner third. Fracture of the Inner Third of the Clavicle. — This is the rarest fracture of the clavicle and has its main anatomical interest in relation to the costoclavicular ligament. This ligament runs obliquely upward and outward from the upper surface of the cartilage of the first rib to the lower surface of the clavicle, a distance of 2 cm. (\|- in.). Immediately in front of the outer portion of this ligament is the insertion of the tendon of the subclavius muscle. The line of the fracture may be either transverse or oblique; if oblique it follows the same direction as do the fractures of the middle third of the bone, viz. , from above, downward and inward. The displacement of the inner fragment is upward and of the outer fragment downward. The displace- ment of the inner fragment upward is promoted by the attachment of the clavicular origin of the sternomastoid muscle: it is opposed by the costoclavicular (rhomboid) ligament and to a less extent by the subclavius muscle. Fracture of the Middle Third of the Clavicle. — The clavicle is most frequently broken in the outer half of its middle third. The bone at this part is most slender; it is here that the anterior curve passes into the posterior; and, finally, it has fewer muscular attachments at this situation. The upper surface has arising from its inner third the clavicular origin of the sternomastoid muscle. Its middle third has no muscular attachments, and on its outer third is the trapezius muscle. On the lower or anterior surface on its inner half is the clavicular origin of the pectoralis major and on its outer third is the deltoid. This leaves the outer half of the middle third free from muscular attachments, with the exception of the subclavius on its under surface. It is through this part of the bone that fractures occur. oblique and always in the direction from above downward and inward. The displacement of the inner fragment is upward, and of the outer fragment downward and inward. This produces the deformity seen in Fig. 256. The inner fragment is pulled up by the clavicular origin of the sternomastoid muscle. The support of the clavicle being gone, the shoulder falls down and in. It is impelled in that direction, first, by the weight of the upper extremity, and, secondly, by the action of the axillary fold muscles, — pectoralis major and minor anteriorly and teres major and latissimus dorsi posteriorly, and by the subclavius to some extent. The anterior edge of the scapula rotates inward and its posterior edge tilts outward. In this manner overlapping is produced, and measurements of the injured and healthy sides taken from the sternoclavicular to the acromioclavicular joint will show some shortening on the injured side. As the continuity of the shoulder-girdle has been destroyed and its prop-like action lost, its function of abduction ceases, and the patient is unable properly to elevate the arm. Sometimes the brachial plexus or subclavian vessels are injured by the inner end of the outer fragment. The artery passes beneath the middle of the bone, the vein being to its inner side and the the outer fragment. brachial plexus to its outer side. We have operated on one such case of injury to the brachial plexus; and cases of hsematoma arising from injury to the veins and aneurism from injury to the artery ha^'e been recorded. way of combating its occurrence is to place the patient in bed on his back. This is the best way of removing the weight of the arm, of quieting the muscles, and by pressure of the scapula close to the thorax of levering the shoulder out (see Fig. 258). Fracture of the Outer Third of the Clavicle. — Attached to the outer third of the clavicle on its under surface, extending not quite to its end, are the coracoclavicular (conoid and trapezoid) ligaments. The conoid inserts into the conoid tubercle near the posterior edge of the clavicle, while the trapezoid is broader and passes from the conoid tubercle outward and anteriorly not quite to the extremity of the bone (see Fig. 267). The bone may be fractured either through the part to which the conoid and trapezoid ligaments are attached, or between them and the end of the bone, a distance of about 2 cm. (i in.). The line of the fracture is either transverse or inclines backward and outward (see Fig. 259). The displacement of the outer fragment is downward and inward. If the fracture is through the ligaments the displacement is not marked. If beyond the ligaments, the shoulder drops, carrying down the outer fragment, and the inner fragment may be elevated slightly above the outer one, but the up-and-down displacement is not latissimus dorsi, and teres major muscles. conspicuous. In many cases the anteroposterior displacement is very marked and peculiar. The outer fragment is bent sharply inward at the site of fracture, producing a deformity which is pathognomonic. It is caused by the curved shape of the bone at this point, by the weight of the arm, and by the action of the muscles passing from the shoulder to the trunk, especially the pectoralis major (see Fig. 259). in reference to the scapula and its muscles which are worth calling attention to. The scapula is liable to be fractured more or less transversely through the body below the spine ; the acromion and coracoid processes have been broken ; it has also been fractured through the surgical neck, and the glenoid process has been chipped off. Fracture Through the Body. — The scapula has attached to its under surface the subscapularis muscle, along its posterior border is the serratus anterior (magnus) and rhomboids, to its dorsum and edge below the spine are attached the infraspinatus, teres minor, and teres major muscles. These are covered by a strong, tough fascia which dips between them to be attached to the bone. Bearing these facts in mind it is readily appreciated why in many of these fractures, which usually tra\'erse the bone below its spine from the axillary to the vertebral border, the displacement is slight, and why healing occurs with some appreciable deformity but with little disability. If, however, the fracture is low down, breaking off the lower angle, then the teres major and lower portion of the serratus anterior (magnus j nuiscles displace the fragment toward the axilla, and this is to be borne in mind in treating the injury. Fracture of the acromion process is more rare than would be expected. It is the result of direct violence, and the displacement and disability resulting from the injury are slight. The acromion is covered by a dense fibrous expansion from the trapezius above and the deltoid below, and these prevent a wide separation of the fragments. Fracture of the coracoid process is also rare and may occur from muscular contraction or direct violence, as in luxation of the shoulder. It might be thought that owing to the action of the pectoralis minor, coracobrachialis, and short head of the biceps muscles, which are attached to it, it would be widely displaced, but this is not so, for the conoid and trapezoid ligaments still hold it in place. Fractures through the surgical neck are not common. They pass down through the suprascapular notch and across the glenoid process or head, in front of the base of the spine and behind and parallel with the glenoid fossa. The tendency of the outer fragment to be dragged down by the weight of the arm is resisted by the coraco-acromial and coracoclavicular (conoid and trapezoid) ligaments as well as by the inferior transverse ligament, which runs from one fragment to the other from the base of the spine, on the posterior surface, to the edge of the glenoid cavity. These ligaments all remain intact. Fracture through the glenoid process, chipping off a greater or less portion of the articular surface, is rarely diagnosed. It occurs sometimes in cases of luxation. The long head of the triceps muscle may be fastened to the detached fragment and is liable to pull it downward and therefore some interference with the functions of the joint would be apt to remain and prevent complete recovery. FRACTURES OF THE UPPER END OF THE HUMERUS. Fractures of the upper end of the humerus may occur through the anatomical neck, through the tuberosities, detaching one or both, and through the surgical neck just below the tuberosities. These fractures are frequently associated with luxation of the head of the bone. Fracture through the Anatomical Neck. — This occurs as the result of direct violence and most often, though not always, in old people. The line of fracture does not always follow exactly the line of the anatomical neck, but may embrace a portion of the tuberosities. The fracture may or may not be an entirely intracapsular one. The capsule in its upper or outer portion is thickened at its humeral end by more or less blending with the tendons of the muscles which pass over it. The capsule at this point is attached to the anatomical neck almost or quite up to the articular surface. On the under side to the contrary it passes about a centimetre below the articular surface and doubles back to be attached somewhat closer to it (see Fig. 266, page 253). In consequence of this arrangement, a fracture which follows the anatomical neck would be within the joint below and just outside of it above. As a matter of fact, some of these fractures are intra- and some partly extracapsular. This influences the amount and character of the displacement and the course of healing. If the fracture is entirely intracapsular, bony union may not occur, as no callus may be thrown out by the upper fragment and atrophy of the fragment may ensue. The fragment is apt to be much displaced, being tilted and lying to the inner side anteriorly. Sometimes it is entirely extruded from the joint. In one case we have seen it lodged in front under the anterior axillary fold. The signs and symptoms will vary much, according to the position of the head, and a positive diagnosis may be impossible. A thorough knowledge of the surface anatomy is essential in these cases and a careful comparison should be made with the opposite healthy shoulder. Impaction sometimes occurs, and is said to be most often of the upper fragment into the lower, sometimes splitting it and detaching to a certain extent one of the tuberosities. Sometimes it is the lower fragment which is impacted into the upper. Fractures through the Tuberosities. — Like the former these are often accompanied by luxation, especially if one or both of the tuberosities is detached. These fractures are frequently blended with fracture through the anatomical neck. In this fracture, however, the influence of the muscles is to be remembered. The supraspinatus, infraspinatus, and teres minor insert into the greater tuberosity, and the subscapularis into the lesser. The line of fracture may pass through their insertions and the displacement may be slight. The upper fragment is, however, liable to be tilted outward by the contraction of the supraspinatus muscle, which is attached to the upper portion of the upper fragment, while there is no muscle attached below to counteract it. In this case the shaft of the humerus is drawn vip and out by the deltoid and is felt beneath the acromion process. There is but little rotatory displacement of the upper fragment because the subscapularis anteriorly is neutralized by the infraspinatus and teres minor posteriorly. In those instances in which there is not much displacement of the upper fragment, the lower one may be drawn inward and forward by the action of the muscles of the axillary folds. Fractures detaching the tuberosities are almost always accompanied by luxation. If the greater tuberosity alone is detached, it is drawn up beneath the acromion by the supraspinatus. In all these fractures the subsequent disability is often great and the prognosis is unfavorable. They are amongst the hardest in the body to correctly diagnose. They are farther on. Fractures of the Surgical Neck, — These are the most common fractures of the humerus. The surgical neck of the humerus is usually defined as the portion between the lower part of the tuberosities and the upper edge of the tendons of . the pectoralis major and latissimus dorsi muscles. Often, however, the tendons of these two muscles continue almost or quite up to the tuberosities, hence there is little or no interval here and the line of fracture then passes through the upper part of these tendons. the force has probably something to do with the displacement of the fragments. Displacement. — It can readily be seen that if a blow is received on the humerus below the tuberosities while the arm is in a somewhat abducted position the head will be supported by the glenoid process (head) of the scapula and the bone will be fractured through the surgical neck and driven in towards the body, and, as the scapula is supported posteriorly, the movable lower fragment is displaced anteriorly. After the fracture has occurred, and possibly in some cases aided by the peculiar direction of the fracturing force, the lower fragment is drawn upward by the muscles running from one side of the fracture to the other. These are the deltoid, biceps, coracobrachialis, and the long head of the triceps. The typical displacement is for the upper fragment to be abducted and some say rotated out — this latter is not without doubt. The lower fragment is certainly in front and to the inside of its normal position. behind nearly or quite balance each other, thus causing little or no lateral displacement. The displacement inward and anteriorly of the lower fragment, is due to the action of the violence as already detailed and is aided by the action of the pectoralis major, the teres major, and latissimus dorsi muscles, all of which pass from the lower fragment just below the seat of fracture inward to the trunk. The longitudinal displacement is peculiar. As the lower fragment is drawn up its upper end may be felt through the deltoid muscle below and toward the inner side of the acromion. While the displacement in most cases is not marked, in some the lower fragment can readily be felt in the axilla (Fig. 261 ). and teres major Fig 261 —Fracture of the surgical neck of the humerus. The upper fragment is held out by the supraspinatus, while the lower fragment is drawn in by the pectoralis major, latissimus dorsi, and teres major muscles and the arm abducted by the deltoid. rotating the arm the head of the bone is found to lie stationary. Treatment. — The ideal treatment is extension with the patient in bed and the arm abducted. As the upper fragment cannot be brought in, an effort may be made to bring the lower one out. As these are usually treated as walking cases a common dressing employed is a shoulder-cap with the arm bound to the side; sometimes an axillary pad is used to keep the arm away from the body. In cases of fracture associated with luxation of the head of the bone, replacement can sometimes be effected by traction in the abducted position and pressure on the head, general anaesthesia being used (see description of direct method of reduction under dislocation of the shoulder, page 236). Separation of the Coracoid Epiphysis. — The coracoid process has three separate centres of ossification which fuse with the body of the bone from the fifteenth to the twentieth year. Therefore displacements occurring before the latter age may be separations of the epiphysis and not true fractures, particularly if the line of separation runs through the base of the coracoid. Separation of the Acromion Epiphysis. — The acromion process is cartilaginous up to the fifteenth year. Then two centres appear and the epiphysis unites with the rest of the spine of the scapula about the twentieth year or later. The epiphyseal line runs posterior to the acromioclavicular joint, just behind the angle of the spine of the scapula. It has been suggested that many cases diagnosed as sprains and contusions of the shoulder are really epiphyseal separations of the acromion process. Separation of the Epiphysis of the Upper End of the Humerus. — The upper end of the humerus has three centres of ossification, one for the head and one each for the greater and lesser tuberosities. These three centres are blended by the seventh year, and the whole epiphysis unites with the shaft at about the age of twenty-five years. The epiphyseal line follows the lower half of the anatomical neck and then passes outward to the insertion of the teres minor muscle. This brings the outer end of the epiphyseal line some distance away from the joint, while the inner portion of the line is within the joint. Disease of this region may therefore follow the epiphyseal cartilage into the joint. A separation of the epiphysis from injury will implicate the joint. The surgical neck of the humerus lies a short distance below the epiphyseal line and farther away on the outer side than on the inner. The line of the epiphysis rises higher in the centre of the bone than on the surface, making a sort of cap for the end of the diaphysis. The symptoms of epiphyseal separation are almost exactly the same as those of fracture of the surgical neck (seepage 245). ■ The supraspinatus is the main agent in tilting the upper fragment outward, while the muscles inserted into the bicipital ridges, — the pectoralis major into the outer ridge and the latissimus dorsi and teres major into the inner, — draw the lower fragment inward. The relati\'e position of the fragments when the lower is displaced outward is seen in Fig. 262. The Flap Method. — One large flap may be made to the outer side and a short one to the inner side CDupuytren) or they may be made anteroposteriorly (Lisfranc). The flap operations were done with long knives by transfixion, as they originated before the discovery of general anesthesia and by them the member was removed with great rapidity fFig. 263). just below the posterior portion of the acromion process (its angle) then passing under the acromion to emerge in front at the coracoid process. This flap was turned up, the capsule and muscles divided, the bone turned out, and while an assistant compressed the remaining tissues they were divided transversely. Lisfranc s method consisted in transfixing the posterior axillary fold from below upward, entering the knife in front of the tendons of the latissimus dorsi and teres major muscles and bringing it out a litde in front of the acromion. The joint was opened posteriorly, the'bone luxated, and an anterior flap cut from within outward. Sir William Fergusson, probably the most skilful operator of his day, was partial to this operation. from which the upper portion of the incision starts. Larrey s Method. — The operation usually ascribed to Larrey consists in starting the incision at the anterior end of the acromion process and continuing it straight down the arm for three centimetres (i^^ in.). It then parts, one branch sweeping gradually in a curved line to the anterior axillary fold and the other to the posterior axillary fold, an incision, through the skin only, passes across the inner surface of the arm joining the two branches. ' The flaps having been turned anteriorly and posteriorly, the joint is opened by cutting on the head of the bone, first posteriorly, then above, and then anteriorly. Tilting the head outward the inferior portion of the capsule is divided and the bone loosened from the soft parts. These are compressed by the fingers of an assistant and cut. Speyice' s Method. — A modification of Larrey's procedure, attributed to Spence by the British and to S. Fleury by the French, consists in commencing the incision just outside of the coracoid process in the interval between it and the acromion process. This modification is probably the best form of procedure for this locality and is the one which will be discussed here. It will be noticed, however, that it practically changes the operation of Larrey from one with anteroposterior flaps to one with a single external flap, as in the method of Dupuytren. (Fig. 263). The incision begins just below the coraco-acromial ligament and lies deep in the hollow formed by the anterior concave surface of the outer third of the clavicle. It divides the fibres of the deltoid muscle longitudinally a short distance from its anterior edge. It will be recalled that the deltoid muscle covers the coracoid process and extends just to its inner side to be attached to the outer third of the lower surface of the clavicle. Between it and the adjoining edge of the pectoralis major muscle runs the cephalic vein. This passes downward and outward along the inner edge of the deltoid until it reaches the outer edge of the biceps muscle alongside of which it passes down to the elbow. This vein will be cut as the inner branch of the incision is made. The bicipital groove, when the palm of the hand faces forward, lies almost directly below the coraco-acromial ligament. While the incision is being made the arm is kept rotated slightly outward. As the knife descends it runs along the inner side of the bicipital groove and divides the tendon of the pectoralis major muscle. As soon as this tendon is cut the incision is inclined laterally. The incision having been carried down to the bone, except on the inside of the arm, the deltoid flap is raised upward and backward. It carries with it the circumflex nerve and posterior circumflex artery. The disarticulation of the bone is apt to be bungled unless one knows the construction of the parts. It is to be borne in mind that the capsular ligament is to be divided together with the tendons of the muscles inserted into the tuberosities. The capsule does not pass across the anatomical neck to be inserted into the tuberosities beyond, and the mistake is often made of cutting on the anatomical neck and therefore frequently the capsule still remains attached to the proximal side. The cut may be commenced posteriorly and should be made 07i the head of the bone just above the anatomical neck. The arm is to be adducted and rotated inward and the muscles inserting into the greater tuberosity cut in their order, first the teres minor, then the infraspinatus and supraspinatus with the joint capsule beneath them. Then comes the long head of the biceps, and the arm now being rotated outward, the tendon of the subscapularis is divided. In cutting the muscles and capsule across the top of the joint, the arm is to be kept close to the side of the body so as to tilt the upper portion of the capsule out beyond the acromion process. The head of the bone can now be drawn out sufificiently to allow the knife to be introduced behind it to divide the inferior portion of the capsule. This should be detached close to the bone so as to avoid wounding the axillary artery and especially the posterior circumflex artery and the circumflex nerve, which wind around the surgical neck immediately below and are to be pushed out of the way. The division is completed by cutting the remaining muscles passing from the trunk to the shaft of the bone. On the inner side may be an uncut portion of the pectoralis major, the coracobrachialis, and short head of the biceps ; below is the long head of the triceps and on the outer side are the teres major and latissimus dorsi. On examining the face of the stump, posteriorly is seen the bulk of the deltoid muscle with the triceps below, and then the latissimus dorsi and teres major tendons lying next to the artery. Anteriorly is the cut edge of the deltoid and pectoralis major with the coracobrachialis and short head of the biceps lying next to the artery. To the outer side of the artery lie the median and musculocutaneous nerves. To the inner side are the ulnar and lesser internal cutaneous nerves {cutaneus brachii medialis) and the axillary vein. Posteriorly are the musculospiral and axillary (circumflex) nerves. The axillary artery is divided below the origin of the anterior and posterior circumflex arteries. The bleeding in the first cut will be from the cephalic vein (which runs between the pectoralis major and deltoid), muscular branches of the posterior and anterior attempted. The avoidance of serious hemorrhage is usually accomplished by clamping the small \essels as the operation proceeds, and before the final division of the axillary vessels slipping the fingers behind the bone and compressing them. Esmarch's tube has been used by encircling the shoulder as close to the trunk as possible, the tube being kept from slipping by a bandage passed beneath it and fastened to the opposite side. Wyeth's pins have been used for the same purpose. One is inserted through the lower edge of the anterior axillary fold a little internal to its middle and brought out abo\'e in front of the acromion process, the other is entered at a corresponding point of the posterior fold and brought out above just behind the angle of the s])ine of the scapula or acromion process. Excision of the Clavicle. — Excision of the clavicle in the living body, Hke tracheotomy, is much more difficult than when practiced on the dead body; this is due to the condition of the parts for which operation is undertaken. It has been often excised for malignant growths. On the upper anterior surface are attached the clavicular origin of the sternomastoid, the deep cervical fascia, and the trapezius muscle. Crossing the clavicle near its middle is the jugulocephalic \ein which sometimes connects the cephalic with the external jugular. It is likewise crossed by the superficial descending branches of the cervical plexus. The external jugular vein, about 2.5 cm. (i in.) above the middle of the clavicle, pierces the deep fascia and turns inward to empty into the internal jugular just behind the outer edge of the sternomastoid muscle; just below it empties the thoracic duct at the junction of the internal jugular and subclavian veins. The subclavian vein is directly behind the clavicle and the left innominate vein crosses behind the left sternoclavicular joint and passes across the posterior surface of the sternum just below or on a level with its head turned to the opposite side, is drawn upward above the clavicle. Behind the upper portion of the clavicle is the suprascapular artery and above it runs the transverse cervical artery, a branch of the thyroid axis. Both these vessels cross o\'er the scalenus anterior muscle on which, toward its inner edge, is lying the phrenic nerve. In front of the scalenus anterior runs the subclavian vein and behind it is the subclavian artery with the cords of the brachial plexus above and to its outer side. Below and in front are attached the pectoralis major and deltoid muscles; the space between them forms the subclavicular triangle and occupies the outer half of the middle third of the bone. The cephalic vein pierces the costocoracoid membrane at this point to enter the subclavian vein. On the under surface of the bone is the subclavius muscle, covered with a strong membrane. To the inner side of this muscle is the costoclavicular ligament. Beneath the clavicle, about its middle, passes the subclavian artery, separated from the vein in front by the scalenus anterior muscle. Below and beneath the subclavian artery, which rests directly on it, is the pleura. The internal mammary artery passes behind the inner extremity of the clavicle opposite the cartilage of the first rib. The clavicle is the first bone in the body to ossify, and it has one epiphysis at its sternal end which appears about the seventeenth year and joins the shaft from the twentieth to the twenty-fifth year. In removing the bone it is first loosened at its outer extremity by dividing the acromioclavicular and coracoclavicular (conoid and trapezoid) ligaments. Excision of the Scapula. — The removal of the scapula necessitates the division of a large number of muscles, for which see pages 226 and 227. The subscapular artery at the anterior border, about 2. 5 cm. ( i in. ) below the head or glenoid process, and the suprascapular at the suprascapular notch, are to be ligated before removing the bone. Skirting the posterior edge is the posterior scapular, the continuation of the transverse cervical artery; it is to be avoided when detaching the muscles. The acromial branches of the acromial thoracic artery ramify over the acromion process; they are not so large as those already mentioned. Mr. Jacobson suggests that if safety permits one should allow the acromion process to remain, as it preserves the point of the shoulder and to some extent, the functions of the trapezius muscle. Excision of the Head of the Humerus. — The incision for the removal of the head of the humerus should be commenced just outside of the coracoid process and be carried 10 cm. (4 in.) downward in a direction toward the middle of the humerus, where the deltoid inserts. This incision may be made while the arm is somewhat abducted but it does not go in the groove between the deltoid and pectoralis major muscles. This groove contains the cephalic vein and the humeral branch of the acromial thoracic artery, and hence is to the inner side of the coracoid process and as the incision is to the outer side, it passes through the deltoid near its anterior edge (Fig. 265). The incision goes through the muscle and exposes the capsule of the joint. The sides of the wound are to be retracted and, if the long head of the biceps muscle is not recognized by sight, the finger is inserted and the arm rotated. The bicipital groove can be felt and the tendon identified. The capsule is to be incised along the outer edge of the long tendon of the biceps and as the arm is rotated inward the supraspinatus, infraspinatus, and teres minor muscles are to be detached from the greater (posterior) tuberosity. The biceps tendon is again brought into view by rotating the arm outward and its sheath (transverse ligament) slit up and the tendon luxated inward. The attachment of the capsule and subscapularis muscle to the lesser (anterior) tuberosity is then divided while the arm is rotated outward. The biceps tendon lies in the bicipital groove between the two tuberosities. When the arm is lying with the palm upward, in a supine position, the bicipital groove looks directly anteriorly in a longitudinal line passing midway between the two condyles of the lower end. The position of the head and groove can be told by observing the position of the condyles. The head is directly above the internal condyle and the groove is on the anterior surface above a point midway between the condyles. After the capsule has been opened and the attachments of the muscles to the greater and lesser tuberosities divided and the tendon of the biceps luxated inward, the head is thrust direcdy upward and out of the wound and sawed off as low as desired. Immediately below the lower edge of the tuberosities is the surgical neck. On it anteriorly winds the anterior circumflex artery, and posteriorly the circumflex (axillary) nerve and posterior circumflex artery. These should not be disturbed, for the artery will bleed and injury of the nerve will cause paralysis of the deltoid muscle. Posterior and transverse incisions have been suggested for this operation but they are not to be advised. The circumflex nerve and posterior circumflex artery are almost certain to be injured and the functions of the deltoid are liable to be seriously impaired or altogether lost. Bicipital groove Fig. 26s. — Resection of the shoulder- joint. The arm has been rotated outward so as to put the tendon of the subscapularis on the stretch. The long tendon of the biceps has been dislocated from the bicipital groove and is held to the inner side by a hook. acromion process and turned down. This does not interfere with its nerve supply. The circumflex nerve going to the muscle crosses the humerus at about the junction of the upper and middle thirds of the deltoid or a finger's breadth above its middle. After resection of the bone the deltoid can again be brought up and sewed to its previous attachment. The character of the operation depends on the nature and extent of the disease. The operator should be familiar with the epiphyseal line, which runs from the inside upward and outward in the line of the anatomical neck as far as the middle of the bone, and then slopes slightly downward and outward to reach the surface almost on a level with the lower (inner) edge of the articular surface. As this is the site of most active growth of the humerus in young subjects this epiphyseal cartilage should be spared as much as possible. The disability arising from a free resection is so great, owing to the loss of movements resulting from the detachment of muscles and interference with the epiphyseal cartilage, that formal resections are rarely performed, but, instead, the diseased parts are simply gouged away and as much allowed to remain as possible. It is to be remembered that rotation inward is mostly performed by the subscapularis and outward rotation by the infraspinatus and teres minor. The supraspinatus aids abduction. A too free excision is hable to be followed by a flail-joint, in which case the limb hangs helplessly by the side with the dorsum pointing forward. The axillary fold muscles insert on the anterior surface of the bone and hence turn the arm inward and draw it in toward the body, they do not compensate for the loss of the muscles attached to the tuberosities. The bleeding in the operation will be mainly from the acromial branches of the acromial thoracic artery and the bicipital branch of the anterior circumflex artery, which runs in the bicipital groove. nor so elaborate. Traumatism may give rise to a synovitis, an inflammation of the synovial membrane, or an arthritis involving the entire joint structures. Sprains and other injuries are not uncommon. A sprain will be caused by a force which acts to a greater extent than the normal movements of the joint will allow. Movements of the Joint. — In abduction the capsule becomes tense at its lower portion when the arm is at 90 degrees to the trunk, greater abduction is resisted by the greater tuberosity impinging on the acromion process and the scapula begins to revolve. Adduction is resisted both by the muscles and by the ligaments. When the ligaments only remain, the head can be separated for 2 cm. or more from the glenoid cavity (see Fig. 266). Marked adduction is usually limited by the arm coming in contact with the side of the body. If the humerus is brought diagonally across the chest the scapula begins to move and its posterior edge and lower angle turn forward. As the humerus is adducted the deltoid and supraspinatus are made tense and the head is drawn up in its socket. When the muscles are paralyzed the weight of the upper extreniity allows the head to fall and a distinct depression can be seen beneath the acromion process. In paralysis of the deltoid this is particularly noticeable. If traction is made on the arm, the muscles are the resisting agents. If the arm is in a position of adduction, those going from the humerus to the scapula, as the deltoid, supraspinatus, biceps, and triceps, act. If in abduction, then also those from the humerus to the trunk, like the pectoralis major and latissimus dorsi, are brought into play. The part played by the deltoid and trapezius should be noted. If the arm is down by the side and traction is made on it, the force is transmitted from the humerus in a direct line through the deltoid and the upper fibres of the trapezius to their attachment to the spine and superior curved line of the occiput. If, on the contrary, the traction is made while the arm is raised abo\'e the level of the shoulder, the force is transmitted through the axillary fold muscles as well as by the deltoid and continued through the lower fibres of the trapezius. In either case the muscles are the resisting agents and not the ligaments. Abduction to more than a right angle is resisted by the contact of the greater tuberosity with the under surface of the acromion process and coraco-acromial ligament and the under side of the capsular ligament is made tense. The raising of the arm to 90 degrees is performed by the supraspinatus and deltoid muscles of the scapula and beyond this by the serratus anterior and other muscles. Inward rotation is limited by the infraspinatus and teres minor muscles and by tension of the upper portion of the capsule. Outward rotation is limited by the subscapularis and upper portion of the capsule. The humerus rotates on its long axis 97° (Macalister). Subacromial Bursa. — Separating tlie greater tuberosity from the deltoid muscle, the acromion process, and coraco-acromial ligament, is the large subacromial bursa. It does not communicate with the joint, except rarely in old people. Effusions into it cause an increased prominence of the deltoid muscle, and pus seeking an outlet is likely to show itself at the anterior edge of the muscle and less often at its posterior edge. These effusions, which are liable to be present from contusions, sprains, etc. , should not be mistaken for intra-articular accumulations. Biceps Tendon. — The long tendon of the biceps muscle enters the joint throuph the bicipital groove between the two tuberosities. With the arm hanging by the side it points directly forward; it passes over the head of the humerus and under the coraco-acromial ligament about midway between the coracoid and acromion processes to insert into the upper edge of the glenoid cavity. It is covered by a synovial sheath which passes with it through the opening in the capsule and a short distance along the bicipital groove. As this sheath does not communicate with the joint the tendon is in one sense extra-articular. It is held in the groove by a fibrous expansion, extending from the pectoralis major tendon below to the capsule above, called the transverse humeral ligament. This ligament is so strong that luxation of the tendon is uncommon; even when the humerus is luxated the tendon is rarely displaced. Subscapular Bursa. — Beneath the tendon of the subscapularis there is a bursa which frequently communicates with the joint. This opening tends to weaken the capsule and it is at this point and just below that the head bursts through in dislocations. Infraspinatus Bursa.— The capsule of the joint and the synovial membrane may be prolonged beyond the rim of the glenoid cavity under the tendon of the infraspinatus, or a bursa at this point may communicate with the joint. Other bursae may be present, but are unimportant. One is between the coracoid process and the capsule and another under the combined tendon of the coracobrachialis muscle and the short head of the biceps. Effusions in the Shoulder-joint. — Liquid accumulations occur both from injury and disease. The liability of confounding them with those in the subacromial bursa has been alluded to above.' As a result of disease, most often osteo-arthritis or tuberculosis, considerable liquid may accumulate in the joint. As the tension increases the arm becomes abducted about 50 degrees and the effusion tends to escape through the openings in the capsule (Fig. 268). A distention of the joint will cause the deltoid to be more prominent. If the affection is in an old person, as is liable to be the case in osteo-arthritis, there is apt to be a communication with the subacromial bursa and this will become distended. If the liquid is purulent it has a tendency to work its way laterally under the deltoid and break through at its anterior or posterior borders and show itself at the folds of the axilla. In osteo-arthritis {arthritis deformans) the long tendon of the biceps as it passes through the joint may be dissolved and the belly of the muscle then contracts and forms a lump on the middle of the arm anteriorly. and shows itself just at the edge of the anterior axillary fold near the middle of the arm. If the pus passes out by way of the subscapular bursa it passes below the subscapular tendon and into the axilla anteriorly. If it passes backward it may emerge through the bursa beneath the infraspinatus muscle, and then either work its way downward into the posterior portion of the axilla, or if it works upward may travel either above or below the spine of the scapula and show itself on the dorsum. The axilla is a wedge-shaped space with its apex upward, formed between the arm and chest at their junction. It serves as a passage-way for the arteries, veins, nerves, and lymphatics passing between the trunk and the upper extremity. It is frequently the site of growths and abscesses, requiring operations which necessitate a knowledge especially of its blood-vessels and lymphatics. Extent. — Its apex lies between the clavicle and scapula above and the first rib beneath. Its base is formed by the skin and fascia stretched between the anterior and posterior axillary folds. It is spoken of as having four walls: inner, outer, anterior, and posterior. The Older wall is nothing more than the chink formed by the union of the two axillary folds. Above is the lesser tuberosity of the humerus and subscapularis tendon, lower down are the coracobrachial and biceps muscles. latissimus dorsi muscles below. Axillary Fascia. — The name a.xillary fascia is given to the fascia which closes the axillary space and forms its base. It is stretched across from the lower edge of the pectoralis major in front to the lower edge of the teres major and latissimus dorsi behind. On the inner wall it is continuous with the fascia covering the serratus anterior (magnus) and side of the chest; when it reaches the vessels at the apex of the axilla it is reflected around them to form the sheath. On the outer wall it passes from the pectoralis major in front, over the coracobrachialis muscle beneath, blends with the sheath of the vessels, and then passes to the posterior wall, covering the subscapularis above and the teres major and latissimus dorsi below. At the lower edge of this latter muscle, which is a little lower than the pectoralis major, it passes across the axilla (Fig. 269). Anteriorly the fascia covers the pectoralis major muscle; at its lower edge it splits to cover the pectoralis minor muscle and forms a sheath for it. As the axillary fascia approaches the apex of the axilla where the superficial vessels enter, it becomes cribriform in character, the fascia itself being Wide-meshed and containing fat in the interstices. If the handle of the scalpel is inserted in the apex of the axilla and worked backward and forward two arches of fascia are readily formed, one convex toward the chest, and called the " Achselbogen," and the other convex toward the arm, called the " Armbogen " (Langer, Oester. med. Wocli., 1846, Nos. 15 and 16). with the costocor-acoid membrane which goes up to the clavicle, where it splits to enclose the subclavius muscle and to be attached to the anterior and posterior borders of the clavicle. The upper portion of this costocoracoid membrane is thickened and forms a firm band which runs from the coracoid process to the cartilage of the first rib, and is called the costocoracoid ligament. Between this ligament above and the upper edge of the pectoralis minor below, and piercing the costocoracoid membrane, are the acromiothoracic artery and vein, the cephalic vein, the superior thoracic artery, external anterior thoracic nerve, and a few lymphatics derived from the breast. The superior thoracic artery is often a branch of the acromiothoracic and passes behind the vein to supply the serratus anterior and intercostal muscles and side of the chest. Teres major and latissimus dorsi Fig. 269. — Axillary fascia. At the apex of the axilla the fascia is almost lacking, forming a curved arch on the side toward the chest, called the axillary arch or " Achselbogen." The curved edge toward the arm, less distinct than that toward the chest, is called the " Armbogen." surface of the subclavius muscle and the deep fascia of the neck. This portion of the fascia is not sufficiently strong to form an absolute barrier between the neck and axilla, consequently abscesses forming in the neck will break through it and passing under the clavicle appear in the axilla, and abscesses starting in the axilla may burrow under the cla\-icle and up beneath the deep fascia of the neck. The axillary artery and vein are both important. The avoidance of hemorrhage in operations in this locality requires skill and knowledge, and venous bleeding is more apt to be troublesome than arterial. Wounds of the \'essels, whether artery or vein, of those portions of the body like the axillae, groins, or base of the neck are particularly dangerous; the blood current is both large and rapid. The axillary vein drains the whole upper extremity and part of the chest, while the axillary artery carries all "".he blood going to those parts. The veins being so much weaker and thinner walled than the arteries is the reason of their being more frequently injured. Ligation of the artery, or vein, or both, may cause gangrene of the extremity and require amputation. The Axillary Artery. — The axillary artery begins at the lower border of the first rib and ends opposite the lower border of the folds of the axilla (teres major). If the arm is lying by the side of the body the artery describes a cur^'e with its convexity outward. If the arm is placed straight out away from the body, the artery is straight. If the arm is abducted above the level of the shoulder, the artery again becomes curved but with its con\'exity downward. The line of the artery is straight only when the arm is out from the body, when its course is represented by a line drawn from the middle of the clavicle to the anterior surface of the elbow, midway between the two condyles. It passes down along the inner side of the coracoid process and the coracobrachialis muscle about at the junction of the anterior and middle thirds of the axilla. It is di\-ided into three parts by the pectoralis minor muscle (Fig. 270). A. H. Young has pointed out that, with the arm out from the body, the upper border of the pectoralis minor is nearly or quite level with the lower border of the first rib, but the muscle leaves the side of the chest to go to the coracoid process and that makes an interspace, more than 2.5 cm. long, above its upper edge and between it and the lower edge of the subclavius muscle, in which the artery can be ligated. In the first portion the axillary artery above the pectoralis minor lies too deep to be compre.ssed, being on a lower level than the pectoralis major, therefore it is better to compress the subclavian above the clavicle. The sziperior thoracic comes off posteriorly and winds around behind the axillary vein to supply the under surface of the pectoralis minor, intercostal muscles, serratus anterior, and side of the chest. It is a small vessel. The acromiothoracic {thoraco-acromialis) is a short large trunk which comes off anteriorly, winding around the edge of the pectoralis minor and piercing the costocoracoid membrane to dixide into four branches: an acromial, to the acromion process; a humeral, which follows the cephalic vein between the deltoid and pectoralis major; a pectoral, which supplies the under surface of the pectoralis major and gives branches to the mammary gland; and a clavicular, to supply the subclavius muscle. Relations. — Posteriorly, \\'\^ artery lies on the first intercostal space and muscle, the second and part of the third serrations of the serratus anterior, the posterior thoracic nerve (or external respiratory of Bell), and the internal anterior thoracic nerve to the pectoralis minor and major. hiternally. — To the inner side of the artery and somewhat anteriorly is the axillary vein; between the two runs the internal a^iterior thoracic nerve. As the artery and vein ascend they become separated, the artery to pass behind and the vein in front of the scalenus anterior muscle. brachial plexus. Anteriorly. — In front of the artery are the skin and superficial fascia, the edge of the pectoralis major muscle and fascia covering it, the costocoracoid membrane pierced by the acromiothoracic artery, cephalic vein, and external anterior thoracic nerve, which goes to supply the pectoralis major muscle. Ligation of the First Portion of the Axillary Artery. — The artery lies deep in the infraclavicular triangle, between the pectoralis major and deltoid muscles. It can be approached by either a transverse or a longitudinal incision. If the former is used it should be made through the skin only, immediately below the clavicle, reaching from just outside the sternoclavicular joint to the coracoid process. angle of the wound the cephalic vein and acromiothoracic artery are to be found. The deltoid muscle is to be detached or pushed outward to expose the coracoid process, this being recognized, the costocoracoid membrane is to be opened to its inner side, between it and the cephalic vein. The acromiothoracic artery if isolated will lead to the artery, while the cephalic vein goes direct to the subclavian vein. The vein and costocoracoid membrane are closely united and great care is necessary to avoid wounding the former in opening the latter. The cords of the brachial plexus are to the outer side of the artery and care is to be exercised not to mistake one of them for the arter^'. As the vein is the most dangerous structure, it is to be displaced inward and the aneurism needle passed between it and the artery from within outward. pectoralis major muscle, if it is seen it should be avoided and not injured. If it is desired to use a longitudinal instead of transverse incision, it should commence just outside the middle of the clavicle and follow the groove between the deltoid and pectoralis major muscles downward for 10 cm. (6 in. ). Great care is then necessary to avoid wounding the cephalic vein and acromiothoracic artery, which lie in this groove. Second Portion. — The second portion of the axillary lies beneath the pectoralis minor muscle. It is 3 cm. ( i >< in. ) long and while never ligated at this point it is nevertheless frequently exposed while clearing out the axilla for malignant growths of the breast. Owing to its being covered by the pectoralis minor and major muscles the artery cannot be compressed at this point in its course. Branches. Its branches are the alar thoracic and long thoracic. The long thoracic or external mammary is of considerable importance on account of its size and because it is encountered in operations on the breast and axilla. It passes down along the lower (outer) border of the pectoralis minor, giving branches to it and the pectoralis major; some branches go to the axilla and serratus anterior, and others, which may be of considerable size in the female, wind around the lower portion of the pectoralis major or pierce it to supply the mammary gland. Posterior Relations. — Anteriorly is the pectoralis minor muscle, superficial to which is the pectoralis major and skin. Posteriorly lie the posterior cord of the brachial plexus, the fat of the axilla, and the subscapularis muscle; internally is the axillary vein, with the inner cord of the brachial plexus separating the two. Externally is the outer cord of the plexus and farther out is the coracoid process. Third Portion. — This is about 7.5 cm. (3 in.) long and runs from the lower border of the pectoralis minor to the lower border of the teres major. Its upper portion is under the pectoralis major but its lower portion is subcutaneous because the teres major, forming the edge of the posterior fold of the axilla, extends lower than the anterior fold. It is here that the axillary artery is most easily reached and most often ligated. and the posterior circumflex. The stibscapular artery is of considerable practical importance; it is the largest branch of the axillary and is given off opposite the lower border of the subscapularis muscle. It follows the lower edge of this muscle down the axillary or outer border the terminal branches of the transverse cervical from the thyroid axis. Four centimetres (i^ in.) from its origin the subscapular gives off the dorsalis scapulcB, which is as large or larger than the continuation of the artery downward. The position of this artery should be borne in mind in operating. It winds around the outer edge of the scapula between it and the teres minor muscle to supph' the muscles posteriorly. The subscapular artery is accompanied by the long subscapular nerve to its inner side. (The first or short subscapular nerve supplies the subscapularis muscle, the second supplies the teres major and the third or long subscapular supplies the latissimus dorsi muscle. ) The posterior axillary chain of lymph-nodes accompanies the subscapular artery, hence it is involved in operations for their removal. The point at which the dorsalis scapulae winds around the axillary border of the bone is at or just above the level of the middle of the deltoid muscle and below the level of the posterior circumflex artery. The anterior circumflex artery is comparatively insignificant. It winds anteriorly around the surgical neck of the humerus beneath the coracobrachialis muscle and both heads of the biceps and gives off an ascending bicipital branch which ascends in the bicipital groo\'e and a small descending branch to the tendon of the pectoralis major. As pointed out by Walsham, the anterior circumflex artery on account of the closeness with which it hugs the bone may be difficult to secure if wounded in the operation of resection of the humerus. The. posterior circumflex artery is much larger than the anterior. It runs around the surgical neck posteriorly, below the teres minor, abo^'e the teres major, and •between the long head of the triceps and the humerus. It is accompanied by the circumflex (axillary) nerve and they run transversely around beneath the deltoid muscle on a level with the junction of its upper and middle thirds. It is to avoid wounding these two important structures that the operation of resection is done anteriorly instead of posteriorly. Being covered only by the skin of the axilla and the superficial and deep fascias, it can readily be compressed by pressure directed outwardly against the humerus along the inner edge of the coracobrachialis muscle. Relations. — Posteriorly the third portion of the axillary artery lies on the subscapularis, the latissimus dorsi, and teres major muscles, with the musculospiral and circumflex (axillary) nerves between the muscles and the artery. Anteriorly it is covered by the skin and fascia, the pectoralis major aboAe, and deep fascia of the arm below. The inner root of the median nerve crosses it and sometimes the outer vena comes. former the more anterior. Ligation of the Third Portion of the Axillary Artery. — The arm being placed out from the body, palm upward, the incision for ligating the axillary artery in the third portion of its course is laid along the inner border of the coracobrachial muscle, at about the junction of the anterior and middle thirds of the axilla and on a line joining the middle of the clavicle and a point at the bend of the elbow midway between the two condyles of the humerus. the axilla. The deep fascia having been opened, the coracobrachial muscle with the musculocutaneous nerve piercing it is pulled outward. Lying on the artery to its outer side is the median nerve; it is to be drawn outward. The needle is passed from within outward. The artery at this point may be crossed by some muscular fibres coming from the latissimus dorsi and crossing the axilla. The axillary vein is the continuation of the basilic from the lower border of the teres major upward. Of the two venae comites of the brachial artery the inner one blends with the basilic at the lower border of the teres major; the outer one crosses the artery to empty into the axillary vein on the opposite side. The axillary vein receives the subscapular, circumflex, long thoracic, acromiothoracic, alar, and cephalic, and contains a pair of valves opposite the lower border of the subscapularis muscle. Collateral Circulation after Ligature of the Axillary Artery. — If the first portion of the axillarv is tied, the acromiothoracic artery comes of? so low down (under the edge of the pectoralis minor muscle almost) that the ligature is placed above it, in which case the collateral circulation is similar to that of the subclavian (see page 149). The second portion of the axillary, lying beneath the pectoralis minor, is not subject to ligation. In the third portion the subscapular and anterior and posterior circumflex arteries come of? so close together that the ligature will be placed either just below or just above them (Fig. 274). axillary region, the axillary nodes proper and the subclavian nodes. The number of the nodes varies from about ten or twelve to twenty or more. When enlarged they are readily seen, but after the surgeon has carefully dissected away all the nodes he can possibly find disease may subsequently reveal the existence of others. Hence it is impossible ever to be absolutely sure that all nodes have been removed. The subclavian nodes, about two or three in number, lie in the infraclavicular triangle between the pectoralis major and deltoid muscles and on the front of the subclavian vein above the pectoralis minor muscle. They receive radicles from the mammary gland as well as from the axillary groups. The axillary nodes proper are composed of three sets, humeral or external, thoracic or anterior, and scapular or posterior, accompanying the three vessels, axillary, long thoracic, and subscapular. are so firmly attached that the vessels are injured in their removal. The atiierior or thoracic set accompany the long thoracic arterv along the lower border of the pectoral muscles. They are not so numerous as the humeral set, perhaps four or five in number, and drain the anterior upper half of the chest above the umbilicus, including the mammary gland (Fig. 275). The posterior or scapular set accompany the subscapular artery along the posterior portion of the axilla. They are about as numerous as the anterior set and drain the upper posterior portion of the chest, the scapula and lower portion of the neck. These lymphatic nodes communicate with one another, so that it does not of necessity follow that if the part ordinarily drained by a certain set is affected the nearest nodes will be involved. It usually is so, but not always. The infection may pass by or through one set of nodes and involve a neighboring communicating set. It happens in carcinoma of the breast that sometimes the posterior or scapular set are involved and the anterior or thoracic set escape. This has already been alluded to in the section on the mammary gland (see page 184). These three sets drain into the subclavian nodes and then empty into the subclavian vein near its junction with the jugular. Abscess of the Axilla. — Pus forms in the axillary region from ordinary pyogenic organisms which may or may not be associated with specific organisms like the tubercle bacillus. Abscesses may be either superficial or deep. The skin of the axilla is thin, loose, and abundantly supplied with sebaceous glands connected with the hair-follicles and sweat-glands. These glands are in the deeper layer of the skin and are superficial to the axillary fascia, hence abscesses originating from them tend to break externally; usually they do not become large nor extend deep into the axilla. Abscesses originating from the lymphatics, on the contrary, may be either deep in the axilla along the axillary, pectoral, or subscapular vessels, or they may be in the axillary fat and" tend to point toward the skin. If the lymphatics along the axillary vessels are the point of origin, the abscess may follow them down under the deep fascia to the elbow. If the nodes high up are involved, the abscess may work up under the clavicle into the neck. If, however, the nodes near the apex of the axilla form the starting-point then the abscess bulges through the cribriform portion of the axillary fascia (between the " Armbogen " and " Achselbogen " ) into the axilla and tends to discharge through the skin. Abscesses originating in the pectoral group of lymphatics point at the lower margin of the anterior axillary fold. The attachment of the serratus anterior to the side of the chest pre\'ents them from working towards the back. Abscesses involving the subclavian nodes may cause a subpectoral abscess (Fig. 276). The pus collects superficial to the costocoracoid membrane and clavipectoral fascia and pushes the pectoralis major muscle outward, forming a large rounded prominence below the inner half of the clavicle. The pus cannot extend upward or toward the median line on account of the attachment of the pectoralis major muscle. It can burrow through the intercostal spaces and involve the pleural cavity, or break through the fibres of the pectoralis luajor anteriorly or between the pectoralis major and deltoid, or, as is most commonly the case, work its way under the pectoralis major muscle, over the pectoralis minor, until it reaches the border of the pectoralis major at the anterior fold of the axilla. fold and a tube introduced beneath the pectoralis major. Incision for Axillary Abscess. — In opening an axillary abscess one should bear in mind that the important veins and nerves accompany the arteries and that the arteries lie in three places, viz. , externally along the humerus, anteriorly along the edge of the pectoral muscles, and posteriorlv along the edge of the sca]:)ula; therefore these three localities are to be avoided and an incision made in the middle of the axilla and short enough not to endanger the brachial vessels on the outside or the long thoracic or subsca])ular on the inside near the chest-wall. Axillary abscesses, if of slow formation and unopened, tend to burrow and follow the vessels upward beneath the clavicle and appear in the supraclavicular space beneath the deep cervical fascia, and they may even enter the superior mediastinum. They may also descend the arm under the fascia covering the coracobrachialis muscle. Axillary Tumors. — Tumors of the axilla are almost always due to involvement of the lymph-nodes. They may be either benign and inflammatory in character, forming the ordinary axillary adenitis, or tuberculous, or they may be malignant. As they are due to disease of the lymph-nodes, the parts which the glands drain should be searched for the starting-point of the affection. Aneurism or abscess may be mistaken for a new growth and an inflamed aneurism may readily be thought to be an abscess. The excision of axillary tumors is difhcult. If the tumor is of an inflammatory origin it maybe closely adherent to the veins or arteries or nerves, and the same condition may exist in malignant cases. The blood supply of the axilla is so free that nothing is to be gained by saving small vessels, therefore in paring a tumor off the axillary vessels the various small branches are ligated and divided and the main vessels left bare. This applies to the veins as well as the arteries. The subscapular artery is so large that it is often allowed to remain. When working in the posterior portion of the axilla it is to be remembered that the posterior circumflex artery is opposite the surgical neck of the humerus, above the tendon of the latissimus dorsi muscle, and that the subscapular artery is on the opposite side of the axillary artery a little higher up. The large subscapular vein will bleed profusely if wounded and it should be looked for at the axillary border of the scapula below the subscapularis muscle. Wounds of the axillary vein are particularly dangerous on account of the admission of air. The attachment of the vein to the under side of the pectoralis minor and costocoracoid membrane keeps it from collapsing; hence the danger. Nerves of the Axilla. — The brachial plexus is above the first portion of the axillary artery. In the second portion one cord is to the inner side, one to the outer, and one behind. In the third portion the median nerve is anterior and a little to the outer side of the artery, being formed by two roots, one from the inner and the other from the outer cord of the brachial plexus. The musculociitaneoiis nerve is to the outer side of the artery, leaving the outer cord to enter the coracobrachialis muscle. The ulnar, internal cutaneous {cuta?ieus antebrachii medialis^ , and lesser internal cittaneoiis {cictaneus brachii medialis^ come from the inner cord and lie to the inner side of the artery. From the posterior cord come the axillary {circumflex^ and r-adial {jmtsculo spiral') nerves. On the inner vv^all of the axilla behind the long thoracic artery is the N. thoracalis longus (long thoracic, or external respiratory nerve of Bell); it is a motor nerve and supplies the serratus anterior (magnus) muscle, hence it is not to be injured in clearing out the axilla. Still farther posteriorly, accompanying the subscapular artery, is the tho7'acodorsalis or long subscapular nerve. It also is a motor nerve supplying the latissimus dorsi muscle; therefore it is to be spared. Crossing the axilla from the second intercostal space to anastomose with the cutaneus brachii medialis nerve is the intercostobrachial {humeral) nerve. It is a nerve of sensation and need not be spared. Sometimes another branch from the third intercostal nerve also crosses the axilla; it is also sensory and can be cut away. the deltoid may ensue. The various nerves of the brachial plexus are often injured by pressure resulting from the use of crutches (" crutch palsy"). It is liable to affect any or several of the nerves, the radial (musculospiral) probably the most frequently. Neuritis is common and, as in injuries, the nerves affected are recognized by the motor or sensory symptoms produced. The arm — or upper arm — is formed by a single bone surrounded by muscles, which, with the exception of the biceps, are attached to it. The main vessels and most of the important nerves run down its inner side. It receives from the trunk the insertions of the muscles which move it, and gives origin to the muscles which move attachment of muscles. the forearm. It is more subject to injury than to disease; infection, caries, and rickets may attack the bone and rarely new growths may occur, but its common affections are wounds involving the muscles, blood-vessels, or nerves, and fractures of the bone. Severe injuries occasionally necessitate amputation. The humerus is a long bone with a large medullary cavity. Its shaft is composed of compact tissue and its ends of cancellous tissue. In shape it is like the letter f, that is, convex anteriorly above and concave anteriorly below. At the middle of the bone on its external surface is the rough deltoid eminence for the insertion of the deltoid muscle. Anterior Surface. — Separating the tuberosities above and running down the anterior surface is the bicipital groove. Its external Hp receives the insertion of the pectoralis major muscle, its inner lip and floor those of the latissimus dorsi above and the teres major below. On its inner side at and a little below its middle, is the insertion of the coracobrachialis muscle. On the anterior surface from the deltoid Posterior Surface. — On the posterior surface, running obliquely across the bone downward and outward, below the insertion of the deltoid, is a shallow groove, called the viusculospiral groove {sulcus radialis). It holds the musculospiral i radial) ne^'ve and the superior profunda artery. Above the groo\'e and to its outer side is the origin of the outer head of the triceps extensor muscle and the insertion of the deltoid. To its inner side, below, is the origin of the inner head of the triceps. Therefore the groove separates the inner head of the triceps muscle from the outer (Fig. 278). MUSCLES OF THE ARM. In order to operate intelligently it is necessary to know the muscles and interspaces, for the latter carry important structures. The arm possesses four sets of muscles. One, an external set, abducts it, the deltoid ; another, or internal set, adducts it (and rotates it in ward j, the pectoralis major, teres major, latissimus dorsi, and coracobrachialis ; another, anterior set, flexes the forearm, the biceps, and the brachialis anticus; and the last, or posterior set, extends the forearm, the triceps, with, sometimes, the suba?iconeus beneath it. shoulder region. The deltoid forms the large rounded prominence of the shoulder. At its insertion the bone is nearest the surface and can be most readily felt. The posterior edge can be plainly seen when contracted running upward and inward and crossing THE ARM. 269 The coracobrachialis arises from the coracoid process and tendon of the short head of the biceps and inserts on the inner surface of the humerus for a distance 5 to 7.5 cm. (2 to 3 in.) opposite the insertion of the dehoid, but extending a Httle lower. In its course from the coracoid process, in its lower part, it is subcutaneous and produces a distinct muscular prominence along the anterior border of the axilla. It occupies about one-third of the width of the axilla and is a guide to the brachial artery. Below the edge of the anterior axillary fold it dips down to insert into the bone and is covered by the biceps muscle. The inner edge of the coracobrachialis is continuous with the inner edge of the biceps. When it contracts it adducts the humerus and brings it forward. The pectoralis major, forming the anterior axillary fold, inserts into the external lip of the bicipital groove from the greater tuberosity above to the insertion of the deltoid below. The tendon is twisted on itself so that the lowest fibres at its origin are inserted the highest, and the highest in origin are the lowest at their insertion. comparatively low down. latissimus dorsi inserts into the bottom of the bicipital groove higher up than the teres major. Hence near the humerus the lower edge of the posterior axillary fold is formed by the teres major and its lower border marks the lower limit of the axillary and the beginning of the brachial artery. The biceps has no attachment to the humerus. It spans the bone and is attached to the scapula above and to the radius and deep fascia of the forearm below. In the lower half of the arm it lies on the brachialis anticus. The long head runs up in the bicipital groove, and is covered by the tendon of the pectoralis major up to the tuberosities, above that by the transverse humeral ligament up to the capsule, which it perforates, and, crossing over the head of the humerus, is attached to the upper edge of the rim of the glenoid cavity (Tig. 280). firmly held in place by the transverse humeral ligament. Pus, in findino; an exit from, the joint, follows the long tendon of the biceps and passes under the transverse humeral ligament, then beneath the tendon of the pectoralis major to appear on the anterior aspect of the arm at its lower border. Luxation of the tendon outwardly would be opposed by the insertion of the pectoralis major, therefore it is only displaced inwardly. Rupture of the long tendon may occur from violent muscular contraction; or, in rheumatoid arthritis of the shoulder, the tendon may become partly dissolved and break. When this occurs the belly of the muscle contracts and forms a large protuberance on the front of the arm (Fig. 281). attached with it to the coracoid process on its outer portion. The pectoralis minor is the third muscle attached to this process. The biceps forms the large muscular swell on the front of the arm between the anterior fold of the axilla and elbow. At its lower end the biceps inserts by a strong tendon into the posterior border of the bicipital tubercle of the radius. An example of its rupture is shown in Fig. 282. Between it and the bone is a bursa, which does not communicate with the elbow-joint. The bicipital fascia is given off from the tendon and passes downward and inward to blend with the deep fascia covering the flexor group of muscles. The biceps not only flexes the radius on the arm but also acts as a powerful supinator. The brachialis anticus covers the lower three-fifths of the humerus and begins with two slips, one on each side of the insertion of the deltoid tendon. It inserts into the inner and lower part of the anterior surface of the coronoid process of the ulna. As the articulation of the ulna and trochlear surface of the humerus is a pure hinge-joint the muscle acts solely as a flexor. cular mass on the posterior surface of the arm is formed solely by the triceps muscle. It arises by three heads and inserts by a single tendon into the olecranon process of the ulna. Its three heads are the long, external, and internal. The long head arises from the lower edge of the glenoid cavity and the scapular border below it for 2.5 cm. (i in.). It blends with the capsule of the joint and tends to strengthen it at this point. When the arm is abducted, this tendon is closely applied to the capsule and head of the humerus, and when the head escapes in luxation, it slips out anterior to the tendon. The external head arises from the humerus above the musculospiral groove and from the external intermusclilar septum; the internal head arises from the humerus below the musculospiral groove and from the internal and the lower part of the external intermuscular septum (Fig. 283). At its lower end the triceps inserts into the olecranon process, the upper third of the ulna, and the deep fascia of the back of the forearm. The expansion of fascia from the olecranon on the inner side is thin and insignificant, but that on the outer side, on the contrary, is thick and strong, and when fracture of the bone occurs is an important factor in preventing separation of the fragments. THE INTERxMUSCULAR SEPTA. The deep fascia of the arm completely encircles it, like a tube. It is continuous above with the fascia covering the deltoid, pectorahs major and teres major muscles, and axillary fascia. Below, it is continuous with the fascia of the forearm and is attached to the olecranon and internal and external condyles. On each side of the lower half of the humerus, extending from the condyles and the bone above outward to the deep fascia, are two fibrous partitions. They are the interjial and external intermiiscidar septa. The space in front of them is filled by the flexors, the biceps, and brachialis anticus, and the space behind contains the triceps extensor. The external septum begins at the external condyle and extends above to the tendon of the deltoid, with which it blends. The internal septum begins below at the internal condyle and extends above to the coracobrachialis. The radial (musculospiral) nerve and anterior terminal branch of the (superior) profunda artery, as they wind around the humerus below the insertion of the deltoid, pierce the external septum. The internal septum is pierced high up by the ulnar nerve and superior ulnar collateral (inferior profunda) artery as they emerge at about the level of the lower portion of the insertion of the coracobrachialis to pass down behind the internal condyle. These intermuscular septa are of importance in operative procedures because they indicate the limits of the muscles and position of nerves and vessels. Inasmuch as the movements of the elbow-joint are anteroposterior only and not lateral, the muscles are principally on the front and back and not on the sides. Hence on looking at an arm a rounded mass is seen anteriorly and posteriorly, and separating them on the sides can be seen in a spare, muscular individual, distinct furrows called the internal and external bicipital fiirrows. If these furrows are obscured by fat, one can still feel that the bone is nearer the surface at these points than elsewhere. The anterior muscle mass is formed by the biceps and brachialis anticus muscles, the posterior mass by the triceps, felt at the insertion of the deltoid at the middle of the outer side of the arm. From this point directly down to the external condyle passes the external intermuscular septum and external bicipital furrow. Winding around from the posterior edge of the insertion of the deltoid is the radial {niusculo spiral ) nerve and {superior) pj-ofimda artery. They pierce the external intermuscular septum and pass downward in the groove formed by the brachioradialis (supinator longus) and extensor muscles on the outside and the brachialis anticus on the inside. On the inner side of the arm the bicipital furrow, between the biceps in front and the triceps behind, is quite evident and marks the internal intermuscular septum, which extends to the medial (internal) condyle. In front of it lie the brachial artery and veins, and median and medial antebrachial {internal) cutaneous nerve. At the upper portion of the inside of the arm can be seen the swell formed by the coracobrachialis muscle. The inner or posterior border of the coracobrachialis is continuous with the inner border of the biceps, and the brachial artery follows them. The coracobrachialis muscle ends just below the level of the insertion of the deltoid, and, of course, can neither be seen nor felt below that point. It is here that the iibiar nerve leaves the artery to pierce the internal intermuscular septum in company with the superior iilnar collateral {inferior profunda) artery to reach the groove behind the internal condyle. The brachial artery is covered only by the skin and superficial and deep fascia, and can be felt pulsating along the inner edge of the biceps muscle and tendon; it can be compressed against the bone by pressure directed outwardly above and inclining more posteriorly as the artery progresses down toward the bend of the elbow. It is on the inner side of the arm in the upper two-thirds, and is more anterior in the lower one- third (Fig. 284). The cephalic vein runs up the external bicipital furrow and the basilic up the internal. At the junction of the middle and lower thirds of the arm the basilic pierces the deep fascia and from that point runs up beneath it and joins with the iyitemal vena comes opposite the lower border of the teres major or subscapularis. THE BRACHIAL ARTERY. The arm being abducted, the course of the brachial artery is indicated by a line drawn from the inner edge of the coracobrachialis muscle, at the junction of the anterior and middle thirds of the axilla, above, to a point just inside the tendon of the biceps at the bend of the elbow, below, midway between the two condyles of the humerus. This lies in the internal bicipital furrow along the inner edge of the biceps muscle. The artery is superficial in its entire course. It is accompanied by two small venae comites, which closely embrace it. The basilic vein runs along its inner side. The median nerve lies on the artery to its outer side above, then directly on it and a Uttle to its inner side at the middle, and passes to its inner side at the bend of the elbow. The medial antebrachial (internal) cutaneous nerve, much smaller than the median, passes down along the inner side of the artery between it and the basilic vein to pierce the fascia about the middle of the arm (Fig. 285). The ulnar nerve lies to the inner side of the artery above and is posterior to the basilic vein. About opposite the insertion of the coracobrachialis it diverges from the artery to pierce the internal intermuscular septum. . In Front. — The branches of the brachial artery are the profunda (superior), the superior ulnar collateral (inferior profunda), the nutrient, muscular, and inferior ulnar collateral (anastomotica magna). Not infrequently the brachial artery instead of di\ iding into the radial and ulnar opposite the neck of the radius divides higher up. This is called a high division and is seen most often in the upper third of the arm. The two vessels may follow the usual course in the arm, or the radial may run under the biceps tendon, instead of over it, and the ulnar may accompany the median nerve in front of the medial condyle or the ulnar nerve behind it. T\\eprofmTda is given off just below the lower edge of the posterior fold of the axilla (teres major). It accompanies the radial ( musculospiral) nerve around the arm to its outer side; it sends one branch, the radial collateral, to the front of the muscle. It is much smaller than the profunda and with the ulnar nerve pierces the internal intermuscular septum. The nidricnt artery comes off close to the origin of the superior ulnar collateral (inferior profunda) or is a branch of it. It passes downward in the bone in a direction toward the (anastomotica magna) is given on 5 cm. (2 in.) above the elbow and passes inward over the brachialis anticus to divide into, two branches, one going down in front and the other behind the elbow. Ligation of the Brachial Artery. — In ligating the brachial artery. Heath strongly ad\'ises that the arm be held by an assistant in an abducted position with the hand supine and not allowed to rest on anything. The object of this is to avoid having the artery overlapped by the triceps being pushed up and thus becoming obscured. The incision is to be made in the line from the inner edge of the coracobrachialis to a point midway between the tips of the condyles. The deep fascia is to be opened and the inner edge of the biceps muscle is to be sought for, recognized, and held outward. The pulsation of the artery may indicate its position in the li\'ing; if not, it is to be sought for to the inner side of the edge of the biceps. The median nerve is not to be mistaken for it. It will lie either over its middle or to its inner side if low down and to its outer side if high up (Fig. 286). The ulnar nerve lies on the inner side of the artery as far as the middle of the arm, it then leaves the artery. Below the middle, if the search is made too far posteriorly, the ulnar nerve and basilic vein will be encountered. The ulnar nerve should not be seen, the basilic vein and median nerve — and above the middle of the arm the medial antebrachial (internal) cutaneous nerve — are to be displaced to the inner side. The needle is to be passed from within outward. Care must be taken not to mistake a large superior or inferior profunda for the main trunk. A high division of the brachial may give two vessels of approximately equal size. Of course, in such a case both must be ligated. Collateral Circulation. — If the ligature is placed above the profunda (superior) branch, the anterior and posterior circumflex will anastomose with the profunda (superior) and superior ulnar collateral (inferior profunda) below. If the ligature is placed between the profunda and superior ulnar collateral arteries, the profunda (superior) will anastomose below with the radial recurrent and posterior interosseous recurrent on the outer side and will also communicate with the inferior ulnar collateral (anastomotica magna) and superior ulnar collateral (inferior profunda) on the inside (Fig. 287). If below the superior ulnar collateral (inferior profunda) then the profunda (superior) would anastomose with the radial and posterior interosseous recurrents on the outside, and the superior ulnar collateral (inferior profunda) with the inferior ulnar collateral (anastomotica magna) and the anterior and posterior ulnar recurrents. AMPUTATION OF THE ARM. In amputation one has to deal with a part of the body that is approximately cylindrical in shape and that contains only a single bone entirely surrounded by soft parts. The circular method is more applicable to amputation of the arm below the insertion of the deltoid than to any other part of the body, but nevertheless in some cases, particularly in muscular arms, difficulty may be experienced in turning back the cuff. In such cases the cuff is slit by the surgeon and the operation becomes one of square skin flaps. For this reason flap amputations are usually to be preferred. The arm may be amputated at any place, high up or low down. Artificial appliances for the upper extremity are comparatively useless; hence the height of division of the bone is determined by the injury. As it is desirable to retain the head of the bone and tuberosities, if possible, in order to preserve the shape of the shoulder and retain the attachment of the muscles, amputation may be done through the surgical neck. This is just below the epiphyseal line. In performing a flap amputation the soft parts should cover or cap the bone like a hemisphere : therefore the total length of the flaps should be equal to one-half the circumference of a sphere whose diameter is the diameter of the limb at the point of section of the bone. If the diameter of the limb is 4 inches, then the total length of the flaps should be approximately 6 inches. If the flaps were of equal length then each would be 3 inches long. If there was only one flap, it would be 6 inches long. It is an axiom in surgery that in flap amputations the artery should be contained in the shorter flap. The operator should accurately know the course of the artery and avoid making his flaps in such a manner as to bring the vessel in the angle of the wound. Otherwise the artery is liable to be split. In a high amputation the external flap may be long and the internal short. In the middle of the arm anteroposterior flaps are preferred and the artery is included in the posterior flap. If the amputation is in the lower third and the flaps are anteroposterior, then the artery of necessity is in the anterior flap. Above the middle of the arm the deltoid, coracobrachialis, and biceps muscles are free and therefore retract markedly when cut. In the middle the biceps only is free and the same is the case in the lower third. The triceps and brachialis anticus are attached to the bone and therefore retract but little when cut. Surgeons ha\^e called attention to the necessity of being careful to see that the radial (musculospiral) nerve is properly divided, otherwise it may be torn by the saw. The groove in which it lies may be unusually deep and necessitate a special effort to divide it. On the face of the stump the artery is to be looked for to the inner side of the bone in the upper two-thirds of the arm and anteriorly in the lower third. Lying on it will be the median nerve and to its inner side the ulnar nerve. At the level of the insertion of the deltoid the radial ( musculospiral) nerve, accompanied by the (superior) profunda artery, will be posterior or toward the outer side. The superior ulnar collateral (inferior profunda) artery is given off at the level of the insertion of the coracobrachialis muscle, which is about opposite the insertion of the deltoid. It accompanies the ulnar nerve. A nerve may be seen lying between the biceps and brachialis anticus. It is the musculocutaneous which becomes superficial just above the bend of the elbow (Fig. 288) . Fractures of the Shaft of the Humerus. — There seems to be but little doubt that in many cases the character of displacement of the fragments in fracture of the shaft of the humerus is due to the mode of injury and not to muscular action. This being so accounts for there being less uniformity in these fractures than in those higher up, which have already been considered. There are some cases, however, in which muscular action does play a part and the possible influence of the muscles should be understood. The line of fracture is usually more or less oblique, in rare cases nearly transverse, but the displacement is often not marked. Notwithstanding this latter fact, non-union of fracture of the shaft of the humerus is one of the most frequent of any in the body. tion of the deltoid and below it. Fracture above the Insertion of the Deltoid. — The bone may be fractured immediately above the deltoid insertion. In this case the powerful axillary fold muscles, pectoralis major, teres major, and latissimus dorsi, being attached to the upper fragment, tend to draw it toward the body, while the deltoid tends to draw the lower fragment out. The influence of the other muscles, biceps, coracobrachialis, and triceps, would be to increase the overlapping (Fig. 2S9;. Fracture below the Deltoid Insertion. — This is the more common site of fracture. The line of fracture is most apt to be from above downward and outward. The upper fragment is displaced anteriorly by the coracobrachialis and anterior portion Fig. 289. — Fracture of the shaft of the humerus just above the insertion of the deltoid and below the insertion of the axillary fold muscles. The lower fragment is seen to be drawn outward by the deltoid; the upper fragment is seen to be drawn inward by the pectoralis major, latissimus dorsi, and teres major. Non-Union. — The humerus has muscles attached to it almost throughout its entire length, and when the sharp ends of the fragments are displaced they probably become fixed in the surrounding muscle, and proper apposition of the fragments is prevented, hence non-union. Hamilton believed that lack of proper fixation was also a prominent cause. The Radial (Musculospiral) Nerve. — In fracture of the shaft of the humerus, paralysis of the extensors due to injury of the radial nerve is comparatively common. It also occurs from pressure due to the use of crutches, to sleeping on the arm, etc. The other nerves are too far remo\'ed from the bone to be injured, but the radial (musculospiral) lies on the bone in the radial ( musculospiral) groove in approximately the middle third of the bone. It comes into contact with the bone posteriorly above the insertion of the deltoid and leaves the bone on its outer anterior surface to pass between the brachialis anticus and brachioradialis (supinator longus)muscles. Paralysis may be caused ( i) by direct injury to the nerve at the time the fracture is received. (2) By subsequent changes in the nerve due to its being stretched over the sharp edge of a fragment. (3) Bv being included in callus. The last is probably much more rarely the case than the two former (Fig. 291). Paralysis should be examined for early in the course of treatment. Too often it is detected only after the splints have been removed, and then it is apt to be ascribed to improper treatment or to misapplied pressure. The symptoms of in\oh'ement of also some sensory changes in the dorsum of the hand and forearm. This nerve is frequently paralyzed from pressure in cases in which there is no fracture, as from sleeping on the arm, the use of crutches, and also in certain systemic affections, such as lead poisoning. It supplies the triceps, part of the brachialis anticus, brachioradialis (supinator longus), and extensor carpi radialis longior muscles in the arm, and then proceeds to the forearm. The branch to the triceps is given of? before the nerve enters the musculospiral groove, hence is not often injured, and loss of extension of the forearm is not often present; even paralysis of the other muscles mentioned is not common, the forearm muscles being mostly affected. The branch to the inner head of the triceps also supplies the anconeus. Caries or necrosis of the humerus may necessitate operative interference at almost any part of the arm. The same may be said of wounds. In operative procedures it is sometimes desirable to avoid important structures and at others to find them. The important structures run lengthwise, hence transverse incisions are not to be used. Most of the large vessels and nerves pass down the inner side of the arm, hence this region is usually avoided. The bone can readily be reached by an incision downward from the insertion of the deltoid, but no operation is to be done in this region without a thorough familiarity with the course of the musculospiral nerve, A line drawn on the posterior surface of the arm from behind and above the insertion of the deltoid to the groove on the anterior surface between the brachialis anticus and brachioradialis (supinator longus) just above and to the inner side of the external condyle will indicate its course. If exposed during an operation bleeding from the accompanying (superior) profunda artery may be expected. The median and ulnar nerves give of? no branches in the upper arm. The median can be readily located by its relation to the artery. It lies to the outer and anterior side of the brachial artery above, then in front, and then to its inner side below. The ulnar nerve lies to the inner side of the artery and between it and the vein posteriorly. In the middle of the arm, it leaves it to pierce and pass beneath the internal intermuscular septum and thence behind the medial (internal) condyle. Operations involving it would be accompanied by bleeding from its companion the superior ulnar collateral artery (inferior profunda). In operations on the lower portion of the bone the position of the inferior ulnar collateral (anastomotica magna), 5 cm. (2 in.) above the elbow, should be borne in mind. It runs on the brachialis anticus muscle and towards the inner and not the outer side. Incisions on the outer side will encounter the cephalic vein in the external bicipital furrow. Incisions on the inner side will encounter the basilic vein ; at the junction of the lower and middle thirds of the arm it pierces the deep fascia. The elbow is so named because at this point the arm is usually bent. A joint is here inserted which permits of flexion and extension ; when the arm is fully extended the "elbow" might be said to have disappeared. The lower end of the humerus forms the proximal portion of the joint and the upper ends of the ulna and radius form its distal portion. Ligaments join these bones together to form the joint, and the blood-vessels and nerves change in character in this region as they pass from the arm to the forearm. The bones are frequently subject to fractures which are of an exceedingly puzzling and disabling character. The joint becomes luxated and the vessels and nerves are not infrequently injured. A thorough knowledge of the anatomy of the region is absolutely essential to the proper treatment of these affections. BONES OF THE ELBOW. Humerus. — The lower end of the humerus broadens laterally and is slightly concave on its anterior surface ; this causes the articular surfaces to look downward and forward and not backward. It carries two articular surfaces: one, the trochlea, for the ulna, and the other, the capitelhim, for the radius. The trochlea, descending lower than thecapitellum, causes the line of the joint to incline downward and inward instead of being directly transverse, thus producing the " carrying angle" (Fig. 294). Extending from the edges of the articular surfaces outward, one on each side, are the condyles, medial {internal) and lateral (extej-nal). Chaussier gave the name epicondvle to the condyles. He called the medial condyle the epitrochlea and the lateral (external) condyle the epicondyle. Henle called the internal condyle the epicondvlus medialis and the external condyle the epicondyhis lateralis. The name epicondyle is now quite generally employed by both surgical and anatomical writers to designate the projecting extra-articular portion of the condyles, so that the terms are practically synonymous (Fig. 293). From the condyles two ridges run upward. The lateral {external) siipracondylar ridge is the more marked of the two and gives origin to the brachioradialis (supinator longus) and the extensor carpi radialis longior muscles, and passes posterior to the deltoid eminence to be continuous with the posterior lip of the radial (musculospiral) groove. The medial {internal) supracondylar j-idge is much less prominent than the lateral and soon blends with the shaft of the bone. Above the trochlea and capitellum anteriorly are two fossae, the coronoid and the radial, to receive the coronoid process and head of the radius when the arm is in complete flexion. On the posterior surface there is another depression, the olecranon fossa, to receive the olecranon process in extreme extension. The projecting hook-hke shape of the median condyle causes it to be more frequently fractured than the less prominent lateral condyle. The two condyles are readily felt directly beneath the skin and are the only points of the humerus that are really subcutaneous. Ulna. — The upper extremity of the ulna articulates above with the trochlea of the humerus and on its outer side with the radius. Its upper end is the olecranon process. The posterior portion of this process is called the tip of the olecranon and is continuous with the posterior surface of the ulna, which is subcutaneous. Immedi- ately in front of the olecranon is a large hollow, which receives the trochlea. It is called the greater- sigmoid cavity. The anterior margin of the cavity is called the coronoid process. On the outer side of the coronoid process is a hollow called the lesser sigmoid cavity, which receives the head of the radius. Fracture of the bone frequently occurs through the narrow portion of the olecranon process into the greater sigmoid cavity. Radius. — The radius ends above in a flat rounded head. The upper surface of this head articulates with the capitellum. The lateral surface articulates internally with the lesser sigmoid cavity of the ulna. The remainder of the circumference of the head is embraced by the orbicular ligament. Immediately below the head is the constricted neck and bicipital tuberosity. To the posterior half of this latter the tendon of the biceps is attached, but its anterior portion is smooth and provided with a bursa. The head of the radius is subcutaneous posteriorly, but the rest is too much covered by muscles to be readily palpated. By the term elbow-joint is meant the articulation between the humerus above and the uhia and upper surface of the radius below. The articulation between the upper end of the radius and the ulna forms the superioi' 7-adio-ulnar articulation and does not belong to the elbow-joint proper. As has already been pointed out, the ulna articulates with the trochlea and the radius with the capitellum. The elbow-joint is a pure hinge-joint. The articulation between the trochlea and ulna is so shaped as to allow no lateral motion, but only an anteroposterior one. The articulation between the capitellum and upper surface of the head of the radius is, on the contrary, a ball-and-socket joint. The socket, it is true, is shallow, but it is perfectly spherical, made so by the rotary movement of the radius in pronation and supination. Hence it follows that the shape and continuity of the upper extremity depends upon the articulation of the ulna with the humerus: it further follows that if the radius be removed from the elbow -joint the forearm would still be held in its proper relation to the arm, but if the ulna be removed the stability of the joint would be lost and the forearm would move in any direction, laterally as well as anteroposteriorly. It is for this reason that injuries involving the medial condyle and trochlea are more liable to be followed by serious disability than are those of the lateral condyle and capitellum. The movement of the joint takes place around a transverse axis, which passes from side to side below and in front of the condyles. The forearm can be extended to an angle of i8o degrees, or a straight line, with the arm. It can be flexed to an angle of 30 to 40 degrees. Sometimes it cannot be flexed so much, so that if after an injury to the joint the patient can flex the elbow to half a right angle, or 45 degrees, he may be regarded as having regained a normal amount of motion. Carrying Angle. — The axis of motion of the joint is not exactly transverse, but slopes slightly from the outside downward and inward. The effect of this is to give a slight obliquity to the motions of flexion and extension. This obliquity is not noticeable except in extreme extension and flexion. When the forearm is completely extended it is seen to lie not in the axis of the arm but to bend outward from the elbow at an angle of 170 degrees. This angle is called the ' ' carrying angle, ' ' because by resting the elbow against the side, any article which is carried in the extended hand is kept away from the body. Sometimes the line of the forearm is almost straight with that of the arm, at others the deflection may amount to 15 degrees. It may vary on the two sides and 10 degrees may be considered an average; Woolsey gives 6 degrees as the average. This carrying angle becomes lost in certain cases of fracture of the elbow, as will be pointed out later. As the elbow is flexed the carr}ing angle disappears (see Hg. 294). When flexion is complete the ulna instead of coming up toward the head of the humerus inclines inward at an angle of 10 degrees. Morris states that the hand has a tendency to point to the middle of- the clavicle, which would make an angle of 20 degrees. This we believe to be too great. Fk;. 294. — The carrying angle; formed by the deviation outward of the axis of the forearm from the axis of the arm. lateral, and external lateral. In all joints there are two kinds of ligaments. One kind serves to retain the synovial fluid; it is a capsular ligament and is usually thin; the other kind is thick, firm, and strong, and is intended to bind the bones together and prevent their displacement and to limit movem.ent. These two kinds of ligaments often blend together so that it is impossible to say where one begins and the other ends; at other places they are quite distinct. If an elbow-joint is distended with eftusion (or wax) the distinction is readily seen. The capsule becomes distended in front and behind, while at the sides the ligaments remain closely applied to the bones ; hence we learn that the anterior and posterior ligaments are capsular in their function while the lateral ligaments are retentive. These will be considered more in detail later. Fig. 295. — The external lateral ligament of the elbow-joint, showing its A shape. Its upper end is attached to the external condyle of the humerus: its lc(wer ends are attached to the ulna. The circular fibres surrounding the head of the radius are called the orbicular ligament. associated with it that it cannot be ignored. The head of the radius, in addition to its movements of flexion and extension on the humerus, possesses a motion of rotation. In order that it may rotate properly the ligaments are arranged in a peculiar manner. Its motion in respect to the ulna is a purely rotary one, so that it is bound to the ulna by a ligament which encircles its head, called the orbicular ligament. The bulk of the ligament encircles three-fourths of the head of the radius and is attached at its ends to the anterior and posterior edges of the lesser sigmoid cavity of the ulna. Its lower fibres are continuous below the lesser sigmoid cavity, forming a complete circle. The upper edge of this orbicular ligament blends with the anterior ligament in front, the posterior behind, and the external lateral at the side. We thus see that as the anterior and posterior ligaments are capsular in their function the radius is kept in place by the external lateral ligament, which branches below in the form of the letter Y to blend with the orbicular ligament. When we consider that these fibres are hardly inserted at all into the radius, but pass over it to the ulna, it is evident that this part of the joint is comparatively weak and not an excessive amount of force would be required to pull the head of the radius from beneath the orbicular ligament and strengthens the joint somewhat. The external lateral ligament is a strong band which is attached above to the lower portion of the lateral (external) condyle, blends with the orbicular ligament and is attached below to the ulna along the anterior and posterior edges of the lesser sigmoid cavity (Fig. 295). The internal lateral ligament is a strong band attached above to the lower and anterior portion of the medial (internal) condyle, the groove beneath, and descends in the shape of a fan to insert into the inner edge of the coronoid process and olecranon (Fig. 296). sides and is attached above to the upper edge of the coronoid fossa and below to the coronoid process and orbicular ligament. It sometimes possesses a few coarse fibres passing downward and outward, but it is mostly very thin, in places barely covering the lining membrane. The posterior ligament resembles the anterior. It blends on each side with the lateral ligaments and is attached above across the upper portion of the olecranon fossa and below to the olecranon and posterior portion of the orbicular ligament. It also has some cross fibres; but, especially at its upper attachment, it is very weak. The elbow-joint is interposed between the long bones of the forearm below and the long humerus above. The arm muscles come down and pass over the joint to insert close to it in the bones of the forearm. The muscles of the forearm in a similar manner cross the joint and are attached comparatively near it to the humerus above. Thus we see the joint strengthened by the crossing of the various muscular insertions. The elbow having only an anteroposterior motion, the muscles must of necessity be in two main groups, one in front and the other behind the joint. Lateral Muscles. — It is true that there are lateral muscles but they have little or no influence on the movements of the elbow-joint. The medial (internal) condyle gives origin to the flexor muscles of the forearm and the pronator radii teres, and the lateral (external) condyle gives origin to the extensor muscles; but the bony attachment of both these sets of muscles coincides too closely with the axis of motion to allow of their aiding to any marked extent either flexion or extension of the elbow. Their function as far as the elbow is concerned is to aid and strengthen the lateral ligaments of their special sides. The Anterior or Flexor Muscles. — These comprise the biceps, brachialis a?iticus, brachioradialis, and extensor carpi radialis longior. It will be observed that the first two muscles come from above and cross the joint, while the last two arise just above the joint to pass down the forearm (Fig. 297). elbow-joint. It passes over the joint and inserts into the base or lower and inner part of the coronoid process. It does not insert into the tip, but some distance below. Its function is purely flexion. The biceps arises from the upper rim of the glenoid cavity by its long head and from the coracoid process by its short head. It inserts into the posterior edge of the bicipital tubercle of the radius. Between it and the tubercle is a bursa. About 4 cm. ( I Y-z in. ) above its insertion its tendon gives off a fibrous expansion which passes inward to blend with the deep fascia covering the flexor group of muscles. This is called the bicipital or semilunar fascia. The biceps tendon passes almost in the middle between the two condyles. Along its inner side is the brachial artery, which is covered by the bicipital fascia; over this fascia passes the_ median basilic vein, sometimes used for transfusion. The insertion of the biceps is into the radius, which is the movable bone, and not into the ulna, which is less so. As a consequence, in addition to its function of flexion it acts also as a powerful supinator of the radius. of the supracondyloid ridge and inserts into the base of the second metacarpal bone. The brachioradialis or supinator longus arises from the upper two-thirds of the lateral (external) supracondyloid ridge above the preceding muscle and as high as the insertion of the deltoid. It inserts into the base of the styloid process of the radius. upper outer portion of the humerus from the greater tuberosity above to the radial (musculospiral) groove below; by its internal or medial head from the posterior surface of the humerus below the radial groove. It inserts into the posterior part of the upper surface of the olecranon. Just above its insertion it is separated from the bone by a bursa. It is continuous from the outer edge of the olecranon as a firm fascia which passes down over the anconeus to be attached to the upper fourth of the ulna and the deep fascia. This is an important structure in fractures of the olecranon. The anconeus passes downward and backward from the lateral (external) condyle to insert into the side of the olecranon and upper fourth of the ulna. Its fibres are practically continuous with the lower fibres of the triceps and it may be considered as a fourth head of that muscle. It covers the posterior portion of the head of the radius and overlaps somewhat the supinator (brevis) muscle. When the elbow is fully extended the bony projections are obscured by the soft tissues, hence in examining an elbow it should be flexed at approximately a right angle. The fi.rst object to strike the eye is the prominent olecranon process. It is subcutaneous and the bony ulna beneath can be felt and followed down the back of the forearm. From the tip upward for a couple of centimetres can be felt the upper surface of the olecranon into which the triceps inserts. To feel this distinctly the forearm should be slightly extended to relax the triceps; the outline of the upper portion of the olecranon then becomes perfectly distinct. Projecting on each side of the elbow are the two condyles of the humerus. These bony projections do not belong to the forearm. The two condyles are nearly on the same level. The medial (internal) is much more prominent and has the appearance of being a trifle higher and slightly anterior. A line joining them crosses the long axis of the humerus at an angle of 90 degrees, but makes an angle of only 80 degrees with the forearm. By deep pressure the lateral (external) supracondylar ridge can readily be felt running up the arm somewhat posteriorly from the lateral (external) condyle. The medial (internal) supracondylar ridge is much less easily felt though the intermuscular septum is more evident on this side. When the elbow is flexed at a right angle a line drawn parallel with the humerus and prolonged through the two condyles will cut the tip of the olecranon. If the forearm i? extended the olecranon passes slightly posterior to this line; if the forearm is flexed, the olecranon passes somewhat in front of it. Hence in examining the elbow for injury it is desirable to determine the relation of these points when the elbow is bent at a right angle. The coronoid process lies anteriorly, deep in the flexure of the elbow, and cannot be distinctly felt. If, now, the elbow is extended, the tip of the olecranon can still be felt with the medial (inner) condyle to its inner side. Between the two is a deep groove in which lies the ulnar nerve. To the outer side of the olecranon is a deep pit or short groove; the bone marking its outer edge is the lateral (external) condyle. In the bottom of this pit at its lower portion, about 2.5 cm. (i in.) below^ the tip of the olecranon, can be felt the head of the radius. If the thumb is placed on it and the hand rotated, the head of the radius can be felt turning beneath. Immediately above the head of the radius, lying to the outer side of the olecranon, if the elbow be again flexed to a right angle, can be seen and felt the bony projection of the capitellum covered by the strong expansion from the triceps. By careful palpation a groove can be felt between the lower edge of the capitellum and the head of the radius which marks the limits and point of articulation of the two bones. On the posterior aspect of the joint the ulnar nerve is the most important structure; there is, however, a bursa between the upper or posterior surface of the olecranon and the skin and also another on its inferior surface, extending downward, which from its exposed position is frequently injured and enlarged. Such an enlargement occurs from chronic irritation in certain occupations, hence the name ' ' miners' elbow. ' ' With the elbow flexed at a right angle there is seen on its anterior surface a crease which runs from one condyle across to the other. If a knife were held parallel with the forearm and entered at this crease, it would strike the humerus above the level of the joint line, that is, the line of contact of the bones. This joint line runs from 1.25 cm. ()^ in.) below the lateral (external) condyle to 2.5 cm. (i in.) below the medial (internal) condyle. Anteriorly the muscular masses form prominent landmarks. In the middle of the crease can be felt the tendon of the biceps muscle. The muscular swell above the crease is formed by the biceps muscle with the brachialis anticus beneath. The sharp upper edge of the bicipital fascia can be distinctly felt when the muscle contracts. The limits of the biceps can be felt as two lines, radiating like the letter V from the biceps tendon upward. These are the commencing bicipital furrozvs or grooves. The outer branch marks the depression between the outer edge of the biceps and the swell forming the supinator group of muscles. The inner branch marks the inner edge of the biceps, and between it and the medial condyle can be felt a muscular mass which is formed by the inner portion of the brachialis anticus. In the middle of the flexure of the elbow below the crease is a depression called the antenibital fossa. To its outer side is the muscular prominence of the extensors and supinator. To its inner side is the muscular prominence of the flexors and pronator. The inner muscular swell ends at the medial (internal) condyle, but the external one passes well up on the arm. The muscles so prolonged upward are the extensor carpi radialis longior for about 5 cm. (2 in.) above the lateral (external) condyle, and the brachioradialis (supinator longus) for 10 cm. (4 in.) higher. The outer limit of the antecubital fossa is formed by the inner edge of the brachioradialis. The inner side is formed by the pronator radii teres muscle. To the inner side of the biceps tendon lies the brachial artery, which bifurcates opposite the neck of the radius, approximately 2 cm. or a finger's breadth below the crease of the elbow. Still farther to the inner side lies the median nerve. In the groove between the biceps and brachialis anticus on the inner side and brachioradialis (supinator longus) and extensor carpi radialis longior on the outer side lies the radial (musculospiral) nerve; it divides above or opposite the lateral (external) condyle into the superficial branch and posterior interosseous nerve The flexure of the elbow is occupied by a number of veins which are of importance from the fact that they are frequently used for purposes of saline infusion, sometimes for blood-letting, and not infrequently they are wounded and give rise to troublesome hemorrhage. They are made more prominent by allowing the arm to hang and by tying a bandage firmly above the elbow. The larger part of the blood from the parts below is carried by the superficial veins; hence the largest veins lie direcdy beneath the skin and can be seen through it. Their arrangement is not always regular but they follow a more or less general plan. The blood from the radial side of the wrist and forearm is carried by the radial vein. The median vein brings the blood from the anterior surface of the wrist and parts above. There are two veins on the ulnar side, an anterior 2Md. 2, posterior. The anterior carries the blood from the anterior ulnar aspect and the posterior ulnar from the posterior ulnar aspect of the wrist and forearm. All these ^-eins contain vah-es at intervals of a few inches. The median vein passes up the middle of the anterior surface of the forearm, and just below the lower edge of the bicipital fascia communicates with the deep veins accompanying the radial and ulnar arteries. This communication is large, distinct, and always present (Fig. 300 ). biceps to the external bicipital furrow. Three or four centimetres abo\-e the bifurcation of the median, the median cephalic vein is joined by the radial, and from that point up it is called the cephalic vein. The two ulnar veins just below the medial (internal) condyle or sometimes just above it empty into the median basilic vein, which from this point is called the basilic vein. Sometimes the two ulnar veins, anterior and posterior, unite and empty, into the median basilic by a common trunk. The median basilic vein passes over the bicipital fascia, which separates it from the brachial artery which lies directly beneath. The median basilic \ein (or cephalic when more prominent; is usually chosen for purposes of saline infusion. It lies to the inner side of the biceps tendon and no important structures are liable to be wounded. The terminal filaments of the musculocutaneous nerve pass under the median cephalic vein and are not liable to be wounded. If the median basilic is chosen for infusion or venesection care must be taken not to cut through the bicipital fascia, otherwise a wound of the brachial artery may be produced which may result in the formation of a varicose aneurism or aneurismal varix. When these veins are wounded the bleeding may be very free. Not only are the superficial parts drained but likewise the deep parts through the communication with the median. We saw one case in which death nearly resulted from such a wound made by a piece of tin. When saline infusion is practised the vein selected is made visible by compressing it above. It is then cut directly down upon and isolated, and the cannula inserted. It is beneath the bicipital or semilunar fascia felt opposite the crease. In the lower third of the arm the median nerve lies close to the artery, but as the bend of the elbow is reached it diverges and becomes separated from it by the coronoid head of the pronator radii teres muscle. Superficial to the deep fascia is the median basilic vein, crossed at its upper portion by the cutaneous antebrachii medialis (internal cuta- the elbow. Ligation of the Brachial Artery at the Bend of the Elbow. — The incision is laid along the inner edge of the biceps tendon. The median basilic vein is usually more prominent than the median cephalic and can be seen obliquely crossing the artery to reach its inner side. This vein is encountered as soon as the skin is divided, hence care is necessary to avoid wounding it. It should be displaced to the inner side along with a filament of the cutaneous nerve if this is present. The incision is then deepened through the upper portion of the bicipital fascia and the artery found beneath, lying in loose fatty tissue and accompanied by two venae comites. The median nerve lies to the inner side but may be sufficiently removed not to be exposed. The needle is passed from the inner towards the outer side (F"ig. 301). Collateral Circulation. — On the outer side the profunda (superior) anastomoses with the interosseous recurrent (a branch of the posterior interosseous) and radial recurrent. On the inner side the superior ulnar collateral (inferior profunda) and inferior ulnar collateral (anastomotica magna) anastomose with the anterior and posterior ulnar recurrent arteries (Fig. 302). In dislocation of the elbow the bones of the forearm are most commonly displaced backward. More rarely they may be partially displaced either inwardly or outwardly and with or without an accompanying backward displacement. The lateral ligaments are strong, the anterior and posterior weak. The formation of the bones permits anteroposterior movement and resists lateral movement; hence the frequency of anteroposterior and the rarity of lateral luxations. To understand and recognize these dislocations and distinguish between them and fractures requires a knowledge of the shape of the bones, the position of the _ articulations, and especially of the relations and significance of the various bony prominences, in other words, surface anatomy. In doubtful cases compare the normal with the injured elbow. Backward Dislocation of the Elbow. — In backward dislocation the radius and ulna are pushed backward and the lower end of the humerus comes forward. It is most commonly caused by falls on the outstretched hand and not by direct injury to the elbow. from the olecranon process to the humerus, and with the periosteum may be hfted up but not ruptured. This is especially the case with the periosteum above the external condyle, as shown by Stimson. The amount of tearing of the muscles depends on the amount of displacement. The flexor muscles may be partly torn from the internal condyle or the extensors from the external. The brachialis anticus probably will be somewhat torn near its insertion in front of the coronoid process. The biceps is not torn but may in some cases be caught behind the external condyle. The orbicular ligament remains intact and holds the radius in its proper relation to the ulna. Viewing the elbow from the side, the anterior portion of the arm abo\-e the crease is fuller than is normally the case. Posteriorly the olecranon is seen projecting, and above it is a distinct hollow. On the outer side of the joint immediately in front of the olecranon is seen a prominent projection caused by the head of the radius. It is to be recognized by placing the thumb on it and rotating the hand. Almost directly above it may be felt,— though it is not at all distinct,— the external condyle (b igs. 303 and 305 ) . On the inner side are seen two rounded bony eminences. The posterior and upper of these is the larger; it is the internal condyle. Below and anterior to this is another; it is the inner edge of the trochlear articulating surface (Figs. 304 and 306). Measurements from the condyle to the acromion process show that they are the same on the injured and the healthy sides. Measurements from the condyle to the styloid process of the ulna show shortening on the injured side. As the lateral ligaments are torn there is abnormal lateral mobility. If the forearm is placed at right angles to the arm, it is seen that the tip of the olecranon no longer lies on a plane drawn through the long axis of the arm and the two condyles, but is considerably posterior to it. The diagnosis as pointed out by Stimson should be based on the positive recognition of the position of the olecranon, the two condyles, and the head of the radius. Treatment. — The lower end of the humerus rests in front of the coronoid process Crarelv fractured ). When the forearm is flexed the triceps becomes tense and holds position of the bones as viewed from the inner side. relaxed by extending the forearm to an angle of about 120 degrees, thus lowering the coronoid process, and extension is to be made on the forearm and counterextension on the arm. Usually an anaesthetic is not required (Fig. 307). outer to the inner surface of the trochlea. The outer condyle then becomes prominent while the inner becomes confused with the olecranon. The identity of the condyles is always to be established by tracing them up the humerus. This dislocation is always incomplete. ulna outward. Outward Dislocation of the Elbow. — In outward dislocation the concave surface of the olecranon rests on the capitellum and in the groove between it and the trochlea. The head of the radius projects far to the outer side of the external condyle. The inner condyle and trochlea become quite prominent and can be readily recognized. Treatment. — Slight flexure of the forearm. Traction and pressure on the radius inward and on the internal condyle and lower end of the humerus outward. Radius. — The ulna alone is rarely luxated (when displaced it would practically be a backward and inward luxation of the elbow) but the head of the radius is not infrequently pulled out of place (Fig. 30S). The accident occurs in children, particularly young ones who, in walking with their elders, are frequently lifted or helped along by a pull on the hand. The pull, accompanied by hyperextension of the elbow and some adduction of the hand, draws the head of the radius from beneath the orbicular ligament and then the tension of the biceps drags it forward. The displacement may be either marked or slight. A marked displacement in the well-developed arm of an adult is readily recognized, but in the fat, chubby, undeveloped arm of an infant it is easily overlooked. Diagnosis. — Pain attracts attention to the part. There is apt to be inability to flex the arm beyond a right angle, due to the radius impinging on the lower end of the humerus. Careful palpation reveals a hollow below the lateral (external) condyle which should be normally occupied by the head of the radius. The outer side of the forearm at the bend of the elbow may be abnormally full and pressure here may detect the head of the radius displaced forward (Figs. 309 and 310). Treatment. — The forearm is to be extended almost to a straight line. Pressure is to be made with the thumb to force the head of the radius back into place. While this is done the forearm is to be flexed on the arm and if the head is replaced the diagnosis and treatment are both difficult and the result sometimes unsatisfactory. The bony processes are less distinct in children than in adults and fractures sometimes pass unrecognized, being considered sprains, until the persistent disability or marked deformity betrays their presence. Luxations and fractures are at times mistaken for one another. For these reasons a working knowledge of the anatomy of the region is indispensable. The fractures that occur in this region are transverse fractures above the condyles and oblique fractures through the condyles, which may either involve the condyles proper (epicondyles so called) and be extra-articular, or involve the articular surface of the trochlea or capitellum. Both condyles may be detached by a T- or Y-shaped fracture: the olecranon may be fractured and also the head or neck of the radius. Transverse Fracture of the Humerus above the Condyles (Supracondylar).— This is the most frequent fracture of the lower end of the humerus. The mechanism of its production is not settled. There is little doubt but that it can be produced by hyperextension, as the bone fractures at this point when luxation does not occur. Hamilton regarded a blow on the elbow as the cause. The line of fracture runs transversely across the bone just above the condyles and obliquely from behind downward and forward (Fig. 311, page 296). Signs. — The overriding of the fragment produces shortening of the humerus as measured from the acromion to the lateral (external) condyle. The olecranon projects backward, causing a hollow above which resembles that produced in backward luxation. The flexure of the elbow is fuller than normal. The relation of the condyles to the tip of the olecranon is not altered. The condyles may, however, lie posterior to a line drawn down the middle of the humerus in its long axis. The sharp edge of the lower fragment can sometimes be felt posteriorly. tension of either the anterior or posterior muscles tends to favor overlapping and to prevent replacement. Full flexion renders the triceps tense. To relax both sets of muscles a position at about right angles is probably best. Stimson has shown that gunstock (angular) deformity frequently follows this injury, hence especial care should be taken to guard against it. It is caused by a tilting of the lower fragment. Instead of a line joining the condyles being at right angles to the long axis of the humerus, it may be oblique, owing to one condyle being higher than the other. Practically it is not possible to recognize this displacement when the arm is bent at a right angle. The splints will fit the part and everything appears satisfactory, but on removal of the splints and extension of the forearm it may be found that the carrying angle has been destroyed and that a gunstock deformity is present. This accident is to be avoided by extending the arm during the earlier periods of treatment before the fragment becomes fixed by callus, and Olecranon Fig. 311. — Transverse fracture of the lower end of the humerus above the condyles. The upper fragment is seen to be displaced forward and the lower fragment with the olecranon is displaced backward. This posterior displacement is increased by tension of the triceps muscle. posterior splints with the elbow bent at a right angle or sometimes acutely flexed. Fractures Involving the Condyles. — The condyles (page 280) have been described as the lateral bony projections of the lower end of the humerus which are extra-articular. Therefore the trochlea and capitellum are not parts of the condyles, and the epicondyles are simply the tips of the condyles. Bearing this in mind it is evident that fractures involving the condyles may be confined to them and not implicate the articular surfaces. They are then extra-articular fractures of the condyles, or they can with some reason be called fractures of the epicondyles. Other fractures may not only implicate the condyles, but pass through them into the articular surfaces. These will be called intra-articular fractures of the condyles. The internal epicondyle (epicondylus medialis) is sometimes called the epitrochlea. process, while the lateral (external) condyle is low, flat, and not prominent. For these reasons fractures of the medial condyle not involving the joint are more common than those of the lateral condyle. In fact extra-articular fractures of the lateral condyle (detachment of the epicondylej are almost unknown, but they have been proven to exist. In extra-articular fractures of the medial condyle, the fragment has been displaced downward by the flexor muscles which arise from it. To counteract this tendency the arm is treated in a flexed position. As the ulnar nerve runs in the groove on the posterior surface of the condyle it has also been injured, and vesicles and impairment of sensation in the course of the nerve have been observed. As the articular surfaces are not involved, no serious deformity or disability need be expected. Intra-artiadar Fractures of the Condyles. — The line of fracture in these injuries usually starts above the epicondyle and passes toward the middle of the bone, chipping off a portion of the trochlear surface or the capitellum. Fractures involving the lateral are probably more frequent than those involving the medial condyle. Intra-articidar Fracture of the Medial Condyle. — The line of fracture passes obliquely through the condyle, entering just above its tip and emerging on the articular surface of the trochlea either in the groove separating the two portions of the trochlea or the groove between the trochlea and capitellum. As already explained (page 282), the integrity of the joint and the line of the arm depend on the trochlea and not on the capitellum, therefore the farther over toward the capitellum the line of fracture goes the more likely is there to be lateral mobility (Fig. 312). The fragment may be pushed up; this carries the ulna up with it while the radius is prevented from following by the capitellum. Therefore the forearm bends inward, making a lateral deformity. The carrying angle (page 282) becomes obliterated and what is known as giinstock deformity or citbitits varus is pro- The deformity is difificult to detect when the elbow is flexed. The condyles and olecranon and shaft of the humerus may all be in the same straight line and still the medial (internal) condyle be higher than normal. If the injury is treated with a right-angled splint the radius and ulna remain in their proper positions but the ulna and medial condyle may both be higher than normal. If this is the case, then, when the forearm is extended, instead of it making an angle of 10 degrees outwardly with the line of the humerus, it may incline 10 degrees or even 20 degrees inwardly : thus it may deviate as much as 30 degrees from the normal direction. To guard against this deformity AUis advised treating the injury with the arm in full extension. Any tendency to lateral deformity will then be at once evident and can be corrected by additional lateral support. Certain it is that no serious fracture of the elbow ought to be treated without frequent examinations of the arm in full or almost complete extension being made from time to time, so as to be sure this deformity is not becoming established. The treatment of fractures involving the joint by placing the elbow in a position of complete flexion has been strongly advocated and as a rule is best, although it has not entirely superseded other methods in all cases. Intra-articidar Fracture of the Late7^al {Fxter7ial) Condyle. — This is also a fairly common injury. The line of the fracture passes from above the tip of the lateral condyle down into the joint through the capitellum or between it and the trochlea. As is to be expected, this does not show the same tendency to lateral deformity as does fracture of the trochlea. When lateral deformity does occur it is because the fracture is so extensive as to also involve the trochlea. This, like the other fractures of this region, is to be diagnosed by grasping the fractured part and detecting crepitus and excessive mobihty. The medial (internal) condyle is felt firmly attached to the humerus and the olecranon to the ulna, but the lateral (external) condyle is felt to move independently of the others. It is efiticiently treated by an anterior (not internal) angular splint. Intercondylar or T Fracture. — When both condyles are detached there is produced what is known as a T fracture. In this injury both condyles are detached from each other and from the shaft of the humerus. The line of fracture may vary. Sometimes there is a transverse fracture above the condyles with a second line passing longitudinally into the joint like the letter T. In other cases the lines may be like the letter V or Y (Fig. 313). In all these cases the mobility is very marked and the limb can be bent at the elbow in any direction. The diagnosis is to be made by grasping the shaft of the humerus with one hand and moving each condyle separately with the other. Having determined that each is detached from the humerus, then one condyle is grasped in each hand and they are moved on one another, thus establishing the fact of a fracture between them. In treatment the same care must be exercised to detect the occurrence of gunstock deformity as has already been advised in fractures of the medial condyle. In these fractures the fragments are frequently rotated on one another, and disability and deformity so often result that in some cases it is advisable to fix the fragments in place by some operative means. Fracture of the Olecranon Process. — The olecranon process may be fractured either close to its extremity near the insertion of the triceps tendon, through approximately the middle of the greater sigmoid cavity, or toward the coronoid process. The second is the more common. The fracture which occurs nearer the insertion of the triceps is liable to occur from muscular action, the triceps contracting and tearing off the piece of bone into which it is inserted. The shape of the process should be noted. In the bottom of the greater sigmoid cavity near where the process joins the shaft it is constricted and weakened by a groove which sometimes passes nearly or quite across its surface. This is the weakest point and is most often the site of fracture. The triceps muscle inserts not only into the upper surface of the olecranon but also along its sides. In addition it sends off a fibrous expansion to each side ; the one to the medial condyle is thin, but the one to the lateral condyle forms a broad, tough, fibrous band which stretches from the olecranon to the lateral condyle and passes down over the anconeus to be attached to the outer edge of the upper fourth of the ulna (Fig. 314). In cases of fracture the fragment is only slightly displaced upward by the contraction of the triceps. The reason is that the fibrous expansion of the triceps usually is not sufificiently torn to allow of the retraction of the fragment. The amount of separation of the fragments is directly proportional to the amount of tearing of the lateral fibrous expansion of the triceps tendon. By extending the forearm the triceps is relaxed and by pushing the fragment down crepitus can often be elicited. Treatment. — Fracture of the olecranon process is usually treated with the elbow slightly flexed. Complete extension is not commonly employed. The slight flexion allows for the effusion into the joint and leaves the arm sufficiently extended to relax the triceps. plete and weak. Fracture of the Coronoid Process and Upper End of the Radius. — Fracture of the coronoid process does occur but it is exceedingly rare. The brachialis anticus does not insert into its tip, but at the lower part of its anterior surface. The fracture is most liable to occur in cases of luxation, the process being knocked of? as the humerus comes forward. upper end of the ulna Portion of the tendon of the triceps which inserts into the posterior surface of the upper fourth of the ulna usually longitudinal and a portion of the head is chipped off. The fragment is liable to become displaced, and either creates inflammation and suppuration or becomes fixed and greatly interferes with motion. For these reasons the fractured head has been frequently excised. A similar displacement may occur when the neck of the radius is fractured. forwards. The classical specimen in the Mutter Museum of the College of Physicians of Philadelphia is usually instanced as an example of this action. The possibility of its occurrence suggests the treatment of the injury with the elbow flexed to relax the biceps muscle. trochlea, and inner portion of the trochlea, appear at the twelfth, third, and twelfth years and fuse and unite with the shaft at about the sixteenth year. The fourth, for the internal condyle, appears at the fifth and unites about the seventeenth or eighteenth year. The epiphyseal line runs close to the edge of the articular surface and is below the level of a transverse line joining the upper edges' of the two condyles (Fig. 315). A true epiphyseal separation would thus be intra-articular and would in\-oh-e comparati\'ely only a thin shell of the articular surface. As already stated most of the cases regarded as epiphyseal separations are probably true supracondylar fractures. Destruction or removal of the epiphyseal cartilage is, of course, if possible, to be avoided in operations in young children, as otherwise interference with the growth of the bone will occur. Ulna. — Most of the olecranon process is a direct outgrowth from the shaft of the ulna. At about the tenth year a thin shell forms at its extremity which unites at the sixteenth year. Therefore fractures which pass through the bottom of the greater sigmoid cavity are not separations of the epiphysis but true fractures. Radhis. — The upper articular surface of the radius has a centre of ossification which appears from the fifth to the seventh year, and unites at the eighteenth to twentieth year. DISEASE OF THE OLECRANON BURSA. Between the skin covering the olecranon process and the bone is a bursa, which, from its exposed position, is not infrequently diseased. It lies in the subcutaneous tissue and resembles in all respects the bursa in front of the patella. In those whose occupation causes them to rest frequently on the elbow, this bursa becomes enlarged, hence the name "miner's elbow." The bursa lies on the posterior surface of the bone and extends from the tip of the olecranon downward in the direction of the forearm. Excision is the most efficient treatment. There are no dangerous structures to be encountered in the operation because the bursa does not communicate with the joint. The position of the ulnar nerve should be borne in mind. It can readily be avoided and usually is not seen. There is sometimes another bursa on the upper surface of the olecranon just below the insertion of the triceps. It is rarely affected. The elbow-joint, like others, is affected with rheumatoid and tuberculous disease. The former frequently causes ankylosis, while the latter frequently causes suppuration. The joint becomes distended and enlarged. The bonv prominences of the elbow, while they may not be visible, ne\'ertheless can usually be recognized by palpation. The lateral ligaments are stronger than the anterior and posterior, hence the swelling is most marked in front and behind. As the internal lateral ligament is stronger than the external lateral, swelling will be more marked on the outer side and the medial (internal) condyle will be more easily recognized than the lateral (external). Pus first works its way posteriorly up behind the tendon of the triceps and then sideways and along the intermuscular septa. As the external supracondylar ridge is nearer the surface than the internal, pus will show itself sooner above the lateral (external) condyle. It may form a protrusion on each side of the triceps tendon and olecranon process. Later it may show itself anteriorly ; when it does so it appears more to the outer than to the inner side, being deflected outwardly through the antecubital space by the attachment of the brachialis anticus to the coronoid process, by the tendon of the biceps and by the bicipital fascia which passes from the tendon over the muscles attached to the medial (internal) condyle. carried down to the bone on the posterior surface of the ulna. The attachment of the triceps to the inner side is then dissected off and the ulnar nerve raised from its groove without injuring it. The medial (internal) condyle is then to be cleared of the muscles attached to it. The parts external to the incision are now to be raised. By means of periosteal elevators aided by the knife the external part of the triceps is detached from the bone as closely as possible, following exactly the edge of the ulna. The anconeus is raised with the triceps and the broad fibrous expansion passing from the olecranon to the lateral (external) condyle and thence over the anconeus to be continuous with the deep fascia is preser^'ed intact. On the care with which this is done depends the amount of subsequent muscular control. As the triceps is turned aside the muscles attached to the lateral condyle are raised in the same manner. The soft parts being drawn to each side the bones are protruded and the remaining soft parts anteriorly can be detached. A flat spatula is then passed beneath the bones and the humerus sawed through opposite the upper edge of the medial (internal) condyle above and the radius and ulna opposite the lower edge of the head of the radius below. The insertions of the biceps and brachialis anticus are not distnrbed.^ In raising the supinator (brevis) from the upper portion or the radius care should be exercised not to wound the posterior interosseous nerve. It runs between two planes of muscular fibres in the substance of the supinator (brevis j. It is a nerve of motion supplying all the extensor muscles with the exception of the anconeus, brachioradialis (supinator longus), and extensor carpi radialis longior; hence its injury will be followed by serious paralysis. Almost no vessels require ligation (Fig. 316). Amputation at this joint is peculiar from the fact of the width of the lower end of the humerus. The skin is loose and show's a marked tendency to retract, especially on the anterior surface. This, combined with the large, expanded end of the humerus, requires ample flaps to be made or difficulty will be encountered in properly covering the end of the humerus. The irregularity of the line of the joint makes disarticulation somewhat difificult 'Fig. 317). A long anterior flap w'ith or without a short posterior one is usually advised. On account of the tendency to retraction the ends of the incision are not carried up to the condyles but are kept at least 2.5 cm. (i in. ) below them. If the flap is cut by transfixion the line of the articulation must be borne in mind. Inasmuch as the trochlear surface projects farther down than the capitellum it is customary to incline the knife dow^nward and inward. Also, as the trochlear portion is thicker, wider, and projects farther than the capitellum, the inner side of the flap is made longer than the outer. The skin on the anterior surface is loose and retracts freely as soon as cut ; hence the muscles are often cut by transfixion. The skin on the posterior surface is not so loose and does not exhibit the same tendency to retraction. After the anterior muscles have been raised and the short posterior skin flap turned back the joint is to THE FOREARM. 303 be opened. The line of the joint runs from i. 25 cm. below the lateral Text. ) condyle to 2.5 cm. below the medial (int. j condyle and is most readily recognized on the outer side, hence the division of the ligaments is to be made from the outer toward the inner side. The point at which to enter the knife is to be found by first feeling the head of the radius in the pit below the lateral (external; condyle posteriorly and then by pressure just above the head recognizing the groove between the upper edge of the head and capitellum. The knife passes directly traversely along between the head of the radius and capitellum, then across the inner portion of the trochlea and is then directed downward and inward around the projecting inner portion of the trochlea. Division of the internal lateral ligament allows the forearm to be bent back and the triceps attachment becomes exposed and can be divided from the front. The appearance of the stump will depend on the manner in which the flaps have been cut. On each side will be the muscular masses from the internal and external condyles. Between them will be the tendons of the biceps and brachialis anticus. The median and ulnar nerves are to be found, the former to the inner side of the biceps tendon and the latter behind the medial (internal) condyle. They are to be shortened. The radial f musculospiral) has already divided into its superficial (radial) and deep (posterior interosseous) branches. The ulnar and radial arteries will probably be found di\ided well anterior on the face of the stump. Some bleeding may be present from the terminal branches of the profunda in front of the lateral condyle, from the superior ulnar collateral f inferior profunda) behind the medial condyle, or from the interosseous or recurrent branches. It is usually not necessary to apply ligatures to the larger superficial veins. The forearm is intimately associated with the functions of the hand. It ser\-es as a sort of pedestal or support, enabling the hand to be carried away from the body, and, by possessing certain movements of its own, — those of pronation and supination, — it increases greatly the range and character of the movements which the hand is capable of executing. The hand is the essential part of the upper extremity and the forearm is subsidiary. Hence we find that, hke the neck, the forearm possesses nerves and blood-vessels much larger than its own proper functions would require and which are destined for the more important parts beyond. It is composed of two bones, the radius and the ulna, which act as the bony support of the part, of a few muscles which move these bones and many more which move the hand and fingers beyond, and of certain ner\^es and blood-vessels that not only supply it but also the parts beyond. The forearm contains two bones, instead of one as in the arm. One of these bones, the ulna, is direcdy continuous with the humerus; the other, the radius, is continuous with the hand. In other words, the ulna is associated with the movements of the arm, and the radius with those of the hand. The large end of the ulna articulates Avith the humerus and its small end is at the wrist, while the large end of the radius is articulated with the hand and its small end with the humerus. The ulna is the bone which acts mainly as a support. It articulates with the humerus by a pure hinge-joint; hence its only motion is one of extension and flexion. It is the fixed bone and does not take part in the movements of pronation and supination, but serves as an anchoring part for the attachment of the muscles which moAe the radius as well as the hand. At its upper extremity it has attached to it the brachialis anticus, triceps, and anconeus muscles, which flex and extend it. At its upper extremity on its outer side is the lesser sigmoid cavity for the articulation of the radius. Its lower extremity ends in a head tipped with a styloid process. The ulna gradually decreases in size from above downward until its lower fourth is reached, when it is slightly enlarged to end in the head. At its lower end, the lateral aspect of the head of the ulna rests in a cavity in the radius to allow of the movements of pronation and supination (Fig. 318). ' The radius is small above and gradually increases in size until its lower extremity is reached, where it is largest. Its upper portion is composed mainly of compact bone with a medullary cavity; lower down as the bone becomes larger it becomes more cancellous. Hence it does not follow that it is strongest where it is largest; on the contrary it is most often fractured at its lower extremity. About two centimetres below the head of the radius is a tubercle. The biceps tendon is inserted into its posterior portion and a bursa covers its anterior part, over which the tendon of the biceps plavs. The radius is the movable bone and to it is attached the hand. hand are transmitted somewhat to the ulna. On its anterior surface run the anterior interosseous miery and nerve. About 2.5 cm. (i in.) above its lower end the artery pierces the membrane to go to the back of the wrist. MOVEMENTS OF PRONATION AND SUPINATION. The radius revolves on the ulna about an axis which passes through the centre of the head of the radius above and the stvloid process of the ulna below, which line if prolonged would pass through the ring finger fFig. 319). In pronation, the hand lies with the palm down and the radius is crossed diagonallv over the ulna; the bones are close together (Fig. 320). In supination the hand lies with the palm up, the bones lie parallel to one another and widely separated (Fig. 321). In the midposition the radius lies above the ulna and the space between them is at its maximum. The difference in this respect between midpronation and complete supination is slight. The head of the radius rotates in the orbicular ligament, the lower end of the radius revolves around the head of the ulna and rests on the interarticular triangular fibrocartilage. The range of movement is from 140 degrees to 160 degrees. The radius is pronated by the pronator teres and pronator quadratus muscles. It is supinated by the brachioradialis, supinator (brevis), and biceps muscles. Some of the other muscles also aid slightly in these movements, especially the flexor carpi radialis in pronation. In fractures the preservation of the interosseous space is essential for the proper performance of pronation and supination; hence anything influenced by the position of the hand, is to be guarded against. The muscles of supination are much stronger than those of pronation ; for this reason instruments intended to be used in a rotary manner turn from the inside toward the outside; that is, in the direction of supination. The screw-driver is an example. The movements of the hand and fingers are so intricate and complex as to necessitate a large number of muscles for their performance. It is probably easiest in order to understand the construction of the forearm to study these muscles in reference to their functions. The muscles which occupy the forearm form three groups, which have separate functions: (r) to flex and extend the fingers; (2) to flex and extend the wrist; (3) to pronate and supinate the hand. I. THE FLEXORS AND EXTENSORS OF THE FINGERS. The finders are moved by two sets of muscles, a long set arising from the forearm and a short set which is confined to the hand. At present we are concerned only with the long extensors and flexors which are found in the forearm. The flexors of the fingers consist of three separate groups of muscles: (i) the fiexor profundus digitorum and flexor longus pollicis, which insert into the distal phalanges; (2) the flexor sublimis digitorum; (3) the palmaris longus which, spreading out into the palmar fascia, is attached to the heads of the metacarpal thumb. The flexor profundus arises from the anterior surface of the ulna and interosseous membrane while the flexor longus pollicis arises from the anterior surface of the radius and interosseous membrane. Their tendons pass through slits in the flexor sublimis digitorum opposite the proximal phalanges to insert into the bases of the distal phalanges. 2. The flexor sublimis digitorum arises from the medial (internal) condyle of the humerus, the coronoid process, the intermuscular septa, and the oblique line of the radius and divides into four tendons which split in front of the proximal phalanges to allow the profundus to pass through and then unite again and insert into the sides of the middle phalanges. There are only four instead of five slips, because the thumb has no middle phalanx but only proximal and distal ones (Fig. 323). 3. The palmaris longus arises from the medial (internal) condyle of the humerus and intermuscular septa and inserts into the palmar fascia, which is attached to the base of the proximal phalanges, to the heads of the metacarpal bones, and blends with the capsules of the metacarpophalangeal joints. It is thus seen to be a perforated muscle exacdy like the flexor sublimis, which it also resembles in function; its attachment is not so far forward. Traction on it tends to flex the proximal phalanx. septa. Three separate slips forming the extensor longus pollicis, extensor brevis poUicis, and extensor ossis metacarpi pollicis go to the thumb. The longus inserts into the distal phalanx, the bre\is into the proximal, and the ossis into the metacarpal bone of the thumb. The extensor communis digitorum divides into four slips, one for each finger. The slip to the index is reinforced by an additional one called the extensor indicis proprius muscle. The slip to the little finger is reinforced by the extensor minimi digiti (ext. digiti quinti proprius; muscle. They divide on the dorsum of the proximal phlanges into three parts, the middle one inserts into the base of the middle phalanx, while the two lateral slips insert into the base of the distal phalanx. The muscles which flex and extend the fingers of course also move the hand as a whole, but in addition to these muscles there are five others, — two flexor muscles and three extensor muscles, — which are inserted into the bones of the metacarpus and not into the phalanges. When these muscles contract they tend to move the whole hand and not the fingers alone. They are the flexor carpi radialis, flexor carpi iihiaris, extensor carpi radialis longior, extensor carpi radialis brevior, and extensor carpi idnaris. The palmaris longus has already been described as a flexor of the fingers. Flexors of the Wrist. Flexor Carpi Radialis. — The two flexors of the wrist, the flexor carpi radialis and the flexor carpi ulnaris, are both superficial muscles lying directly beneath the skin. The flexor carpi radialis arises from the medial (internal) condyle of the humerus and intermuscular septa and lies between the pronator radii teres externally and the palmaris longus internally. It runs obliquely across the forearm, striking the wrist at about the junction of the middle and outer thirds. It lies next to and to the outer side of the palmaris longus tendon and to the ulnar side of the radial artery and inserts into the front of the base of the second metacarpal bone (Fig. 324). Flexor Carpi Ulnaris. — The flexor carpi ulnaris arises by two heads, one from the common tendon of the medial (internal ) condyle and the other from the olecranon process and upper two-thirds of the ulna. The two heads are separated by the ulnar nerve, which passes down in the groove between the medial condyle and olecranon process. The muscle passes straight down the anterior and inner surface of the ulna to insert first into the pisiform bone and unciform process and then to continue over to the base of the fifth metacarpal bone. The pisiform bone is a sesamoid bone in the tendon of the flexor carpi ulnaris muscle. arises^tVom X V^'^' Radialis Longior. The e.xtensor carpi radialis longior arises trom the ower third ol the external supracondylar ridge and the lateral rexternal; condyle and inserts into the back of the base of the second metacam!l bone. When it contracts it tends to tilt the hand toward the rXl side as7eU joint, it also aids in flexing the elbow. Extensor Carpi Radialis Brevior. — The extensor carpi radialis brevior arises from the common tendon of the lateral condyle and fascia, and, running down parallel to the longior muscle, inserts into the base of the third metacarpal bone. It is covered by the extensor carpi radialis longior muscle and lies on the supinator rbre\-is). It acts as a pure extensor of the wrist (Fig. 325). Extensor Carpi Ulnaris. — -The extensor carpi ulnaris arises by two heads, one from the lateral (external; condyle and the other from the posterior surface of the ulna through the fascia common to it, to the flexor carpi ulnaris, and to the flexor profundus digitorum. It inserts into the base of the fifth metacarpal bone. It extends the wrist and tilts the hand toward the ulnar side. 3. PRONATORS AND SUPINATORS OF THE HAND. The movements of pronation and supination have already been described (page 304). They are performed by five muscles, two pronators and three supinators. The pronators are the pronator radii teres and the pronator quadratus. The supinators are the brachioradialis {supinator longus), the supinator {brevis), and the biceps. Pronators of the Hand. Pronator Radii Teres (Rotind Pronator). — The pronator radii teres arises by two heads, one from the medial (internal) condyle and the other, much smaller, from the inner surface of the coronoid process. The median nerve passes between these two heads. The muscle crosses the forearm obliquely and inserts by a flat tendon into the middle of the outer surface of the radius. It rotates the radius inward and tends to draw it toward the ulna and flex it on the humerus. The influence of this muscle is marked in displacing the radius when fractured. Pronator Quadratus {Square Pronator). — The pronator quadratus arises from the volar (palmar) surface of the lower fourth of the ulna and inserts into the lateral and anterior surface of the radius. By its contraction it rotates the radius toward the ulna and in cases of fracture tends to draw the bones together and thus endanger the integrity of the interosseous space (Fig. 326). Brachioradialis {Supinator Longus) . — The brachioradialis arises from the upper two-thirds of the lateral (external) supracondylar ridge of the humerus and inserts into the base of the styloid process of the radius. When the hand is in a state of pronation contraction of the brachioradialis will tend to supinate it. It also acts as a flexor of the elbow, as has already been pointed out. It is superhciai and is an important guide both to the radial (musculospiral) ner\'e and to the radial artery. Supinator {Brevis). — The supinator arises from the lateral condyle, the external lateral and orbicular ligaments, and the triangular surface of the ulna below the lesser sigmoid cavity. It winds around the posterior and external surfaces of the radius and inserts into the upper and outer portion, covering its head, neck, and shaft as low down as the insertion of the pronator radii teres muscle. It lies deep down beneath the mass of extensor muscles and supinates the radius. It is pierced by the deep branch of the radial (posterior interosseous) nerve which bears the same relation to it as does the external popliteal ner\'e to the peroneus longus muscle in the leg. Biceps Muscle. — The biceps muscle has already been described. Arising by its long head from the upper edge of the glenoid ca\-ity and by its short head from the coracoid process it inserts into the posterior portion of the tubercle of the radius. While its main function is that of flexion of the elbow, still, from the manner in which it winds around the tubercle of the radius, it acts as a powerful supinator when the hand is prone and it is a disturbing factor in the displacements which occur in fractures of the bones of the forearm. The forearm has the shape of a somewhat flattened cone, being large above and small below. This is because the belUes of the muscles lie above and their tendons below. Most of the muscles of the forearm go to the hand and fingers. The prehensile functions of the hand require a strong grasp; hence it is that we find the fle.xor muscles on the anterior surface of the forearm much larger and more powerful than the extensors posteriorly, and the bones of the forearm, the radius and ulna, nearer the surface posteriorly. subcutaneous fat and the degree of development and contraction of the individual muscles. The skin of the forearm is loose and thin. Through it can be seen anteriorly, the median vein going up the middle and the radial \-ein winding around the back of the wrist and crossing the outer edge of the radius about its middle. On the inner side near the elbow the anterior and posterior ulnar veins are visible passing posteriorly. Sometimes there is a slight depression on the inner side below the medial (internal) condyle which is caused by the bicipital fascia holding the muscle down. The biceps tendon can be felt at the bend of the elbow, and immediately below it for the distance of 5 cm. (2 in. ) can be felt a hollow, the antecubital fossa. The mass of muscles between it and the ulna on the inside and posteriorly are the flexors and pronator radii teres; the mass of muscles on the outer side between it and the radius posteriorly are the extensors, supinator (brevis), and brachioradialis. The inner edge of the brachioradialis is indicated by a line drawn from the outer side of the biceps tendon to the outer surface of the styloid process of the radius. A hne from the medial (internal) condyle running obliquely across the forearm to the middle of the radius indicates the pronator radii teres muscle. A line from the medial condyle to the middle of the wrist indicates the palmaris longus muscle; it is sometimes absent. Another line from the same point above to a centimetre to the radial side of the palmaris longus tendon at the wrist indicates the flexor carpi radialis muscle. The tendons of both these muscles can readily be seen. A hne drawn from the medial (internal) condyle to the pisiform bone at the wrist indicates the anterior edge of the flexor carpi ulnaris muscle. Having located the superficial muscles the arteries and nerves can be traced. The brachial artery bifurcates about a finger' s breadth below the bend of the elbow. A line drawn from the inner edge of the biceps tendon, or a point midway between the two condyles, to the anterior surface of the styloid process of the radius indicates the course of the radial artery. In the upper half of the forearm it is overlapped by the edge of the brachioradialis. In the lower half it is uncovered by muscle and lies in the groove formed by the brachioradialis on the outer side and the flexor carpi radialis on the inner. The ulnar artery describes a marked curve to\vard the ulnar side until it reaches the middle of the forearm, when it passes down in a straight line from the medial T internal) condyle to the radial side of the pisiform bone. The median nerve runs down the middle of the forearm, lying beneath the groove separating the palmaris longus and flexor carpi radialis tendons. The ulnar nerve runs from the groove between the medial ( internal j condyle and olecranon process above to the radial or outer side of the pisiform bone below. It lies to the ulnar side of the ulnar artery in the lower half of the forearm. The rounded muscular mass between the edge of the flexor carpi ulnaris and the palmaris longus is formed by the flexor sublimis digitorum muscle (Fig. 327). Posterior Surface. — The posterior surface differs from the anterior in the bones being mere conspicuous — they are subcutaneous. Of the two the ulna is the more evident. At the elbow the olecranon and the capitellum to its outer side are well marked and some distance inwardly is the medial (internal) condyle. By palpation the ulna can be traced down the forearm almost subcutaneous, running from the olecranon process, in a gentle curve toward the median line, down to its styloid process at the back of the wrist. It is covered only by the skin and superficial and deep fascias. About 3 cm. (i}( in. ) to the outer side of the olecranon can be felt the lateral (external) condyle and capitellum. If the elbow is extended a dimple is seen just below the capitellum ; it marks the position of the head of the radius, and by pressure the groo\e separating the head from the capitellum can be felt. By placing the thumb of one hand in the dimple on the head of the radius, and rotating the hand of the patient with the other, one can feel the bone rotate and thus be assured that the radius is intact. Whenever fracture of the radius is suspected this is the procedure resorted to in order to determine whether or not it is broken. The radius can be followed only for an inch or so below the dimple, when it disappears beneath the muscles to again become subcutaneous on the outer side of the forearm, about its middle, from thence it can be followed more or less distinctly down to the styloid process on the outer side of the wrist. the olecranon down the back of the forearm to the styloid process. The line of the ulna is usually marked by the presence of a groove. To the ulnar side of the groove lie the flexor carpi ulnaris and the other flexors; to the radial side lie the extensor carpi ulnaris and the other extensors (Fig. 328). From the dimple marking the head of the radius a groove in the muscles can be felt which runs to the middle of the outer surface of the radius. Anterior or to the palmar side of this groove lie the brachioradialis and extensor carpi radialis longior with the supinator (brevis) beneath. The muscles posterior or between the groove and the ulna are the extensor carpi radialis brevior, extensor communis digitorum, and extensor carpi ulnaris. Passing over the lower third of the outer side of the radius are the tendons of the e.xtensor ossis metacarpi poUicis and extensor brevis pollicis muscles. As they are here subcutaneous, this is the point at which creaking can be felt when they are affected with tenosynovitis. some hemorrhage which they cause when wounded. At the bend of the elbow, a finger's breadth below the crease and opposite the neck of the radius, the brachial artery dixides into the 7'adial and 2ilnar arteries. These are continued through the forearm to enter the hand, the ulnar anteriorly over the annular ligament and the radial posteriorly through the " anatomical snuf5-box." The ulnar artery is larger than the radial and in its upper half it describes a curve with its convexity toward the ulnar side passing beneath the pronator radii teres and superficial flexor muscles arising from the medial (internal ) condyle. It is accompanied by vense comites but not by any nerve in this portion of its course. Just above the middle of the forearm the ulnar nerve joins the artery, lying to its ulnar side, and accompanies it down into the hand. In the lower half of its course the ulnar artery lies to the radial side of the flexor carpi ulnaris muscle, being slightly overlapped by it. The flexor sublimis on the radial side also tends to overlap it. The covering of the artery, partially at least, by these muscles, together with the thickness of the deep fascia and the lack of a proper bony support beneath, cause the pulse from the ulnar arterv to be less distinctly felt than that from the radial. When the artery passes beneath the pronator radii teres muscle it is crossed by the median nerve, which lies superficial to the artery, and is separated from it by the deep head of the muscle. The branches of the ulnar artery in the forearm are the anterior and posterior ulnar recurrents, the common interosseous, muscular, nutrient, and anterior and posterior ulnar carpal branches (Fig. 329). The common interosseo2is arterv comes off from the ulnar about 2 to 3 cm. from its origin and di\ides into the volar (anterior) and dorsal (posterior) interosseous arteries. The anterior gives a branch to the median ner^•e — the comes nervi median! — a nutrient branch to the radius, and, on reaching the upper edge of the pronator quadratus, sends a posterior terminal branch through the membrane and an anterior terminal branch into the muscle. The posterior interosseous passes beneath the oblique ligament to the back of the forearm and gives off the interosseous recurrent, which runs up between the lateral (external) condyle and the olecranon and then gives branches to the various muscles. The radial artery, though smaller than the ulnar, seems to be a direct continuation of the brachial because it proceeds in the same general direction while the ulnar branches off to one side. It is divided into three parts according to the region it traverses, viz., the forearm, the wrist, and the hand. It describes a slightly outward curved line from a finger's breadth below the middle of the crease of the elbow to a point on the front of the radius at the wrist, i cm. (f in.) inside of its styloid process. It is superficial in nearly its entire extent, being overlapped only by the edge of the brachioradialis (supinator longus) in its upper third. This muscle lies to its outer side all the way down to the styloid process. In the middle third the cutaneous branch of the radial nerve lies close to the outer side of the artery, but in the lower third the nerve leaves it to become subcutaneous, passing more toward the dorsum. To the inner side of the artery is the pronator radii teres muscle in its upper third and the flexor carpi radialis for the rest of its course. At the wrist it rests on the anterior surface of the radius, a centimetre to the inner side of its styloid process. By compressing the vessel against the bone its pulsations can be readily felt, and here is where the finger is applied in taking the pulse. radial nerve, in the groove between the brachialis anticus and brachioradialis. The anterior carpal is a small branch which joins with the corresponding branch of the ulnar and anterior terminal branch of the anterior interosseous to form a socalled anterior carpal arch which anastomoses with branches of the deep palmar arch to supply the bones and joints of the carpus. The superficial volar leaves the radial artery just before it crosses the external lateral ligament. It pierces the muscles of the thumb to anastomose with a superficial branch of the superficial palmar arch. Sometimes this artery is so large that it can be seen pulsating as it passes over the thenar eminence from the wrist downward. Ligation of the Ulnar Artery in the Forearm. — The ulnar artery between the elbow and wrist is so large that when wounded it may require ligation in any part of its course. On account of the artery being deep beneath the flexor muscles in the upper part of the forearm, the middle and lower portions are to be preferred for ligation (Fig. 330). Ligation in the Upper Third. — This is done only for wounds. The superficial incision may be made in a line from the medial (internal) condyle to the middle of the outer border of the radius. The fibres of the pronator radii teres are to be parted, not cut, and the artery searched for crossing the wound almost at right angles, on a line from the bifurcation of the brachial artery to the middle of the inner border of the ulna. The artery is to be found lying between the superficial flexor muscles arising from the medial condyle and the deep muscles arising from the two bones and the interosseous membrane. It lies beneath the ulnar head of the pronator radii teres, which separates it from the median nerve, which is superficial to it and nearer the median line. Ligation in the Middle Third. — The ulnar artery reaches the inner edge of the ulna at its middle and from thence downward runs in a straight line from the medial (internal) condyle to the radial side of the pisiform bone. It lies directly under the deep fascia and along the radial or outer edge of the flexor carpi ulnaris muscle, which can be made tense by extending and abducting the hand. In the upper part of its middle third the artery lies under the edge of the flexor sublimis digitorum and the ulnar nerve lies a short distance to its ulnar side. In the lower part of the middle third the artery and nerve lie close together, the nerve being next to the tendon of the flexor carpi ulnaris. The tendon^ to the radial side of the artery is one of the slips of the flexor sublimis digitorum. If difificulty is found in recognizing the edge of the flexor carpi ulnaris after the skin incision has been made the hand should be extended and abducted: this may make the muscle tense. Sometimes the intermuscular space is marked by a white or yellow (fatty) line or by some small blood-vessels coming to the surface at this point. The edge of the flexor carpi ulnaris is more likely to be to the radial than to and artery from the ulnar toward the radial side. Ligation i?i the Lozuer Third. — The relations of the artery are practically the same as in the lower part of the middle third. In the superficial fascia one of the branches of the anterior ulnar vein may be encountered. It should not be mistaken for the artery. The artery lies beneath the deep fascia ; the edge of the flexor carpi ulnaris muscle should be clearly recognized. The deep fascia is apt to have t\vo lavers. one passing from the edge of the flexor carpi ulnaris over the flexor sublimis while the other, more superficial, goes more to the anterior surface of the annular NERVES OF THE FOREARM. Injuries of the large ner\es of the forearm are followed by much disability. When these nerves are divided in wounds it is desirable to unite the ends immediately. The reunion of nerve-trunks which have been divided some time previously is also occasionally necessary. These operations demand on the part of the surgeon an accurate knowledge of the topography of the part. For our purpose we may consider the nerves of the forearm as beino- of two kinds — trunks and branches. There are two main trunks — the median and the uhiar ; the superficial (radial), and deep (interosseous) branches of the radial (musciilospiral), and forearm branches of the median and ulnar form the second class. The main trunks simply traverse the forearm to be distributed in the hand, therefore injury to them shows itself by disabilities of the hand. The branches supplying the forearm, if of sensation, rarely give rise to any serious effects requiring surgical interference. The motor branches enter the muscles of the fore- arm so high up that paralvsis usually is seen only when the nerves are injured in the region' of the elbow or above. The high entrance is caused by the bellies of the muscles being above and the part below being tendinous (Fig. 331). The Median Nerve.— The median nerve at the elbow-joint lies internal to the brachial artery, which lies next and internal to the biceps tendon. It lies on the brachialis anticus muscle and under the bicipital fascia. It crosses the ulnar artery obliquely a short distance below its origin. The artery curves toward the ulnar side while the nerve has a slight curve toward the radial side; between the two passes the ulnar head of the pronator radii teres muscle. The nerve then proceeds downward between the superficial and deep layers of muscles. It lies on the flexor profundus digitorum and is covered by the flexor sublimis ; about 5 cm. above the annular ligament it becomes more superficial and lies in the interval between the palmaris longus and flexor carpi radialis tendons and touching them. It then passes under the annular ligament to enter the palm of the hand. A branch of the anterior interosseous artery called the comes nervi mediani accompanies the nerve in the forearm. and palmar cutaneous branches, besides those in the hand. The superficial flexor muscles, with the exception of the flexor carpi ulnaris, are supplied by branches directly from the main trunk near the elbow ; the one to the pronator radii teres usually comes off above the elbow. The deep flexor muscles, v/ith the exception of the inner half of the flexor profundus digitorum, are supplied by the volar ('anterior) interosseous branch. The volar {anteraor) interosseous nerve leaves the main trunk of the median just below the elbow and accompanies the volar (anterior) interosseous artery, lying on the interosseous membrane between the flexor longus pollicis and the flexor profundus digitorum. It supplies the flexor longus pollicis and radial half of the flexor profundus muscles as well as the pronator quadratus. The palmar cntaneoiis branch is given off just above the annular ligament and comes to the surface between the palmaris longus and flexor carpi radialis tendons. It passes over the annular ligament to be distributed to the thenar eminence and palm of the hand. W^ounds of the Median Nerve. — The median nerve may be wounded in any part of its course in the forearm, but it is superficial only in its lower portion for about 5 cm. above the wrist. From this point up it is covered by the flexor sublimis, the flexor carpi radialis and the pronator radii teres. While these muscles tend to protect it from injury, if the traumatism is extensive enough to divide it they render it all the more difficult to treat. Accompanying the nerve, especially in the middle third of the forearm, is the comes nervi mediani artery, which may cause annoying bleeding. Careless attempts to secure the artery may injure the nerve. Should the nerve be divided, paralysis ensues of all the superficial flexor muscles except the flexor carpi ulnaris, and of the deep muscles, except the inner half of the flexor profundus. This includes the pronator radii teres and pronator quadratus, so that the power of pronating the forearm is impaired as well as the ability to flex the hand. The flexor carpi ulnaris and outer half (that going to the ring and little fingers) of the flexor profundus digitorum are the only flexor muscles not paralyzed. The paralyzed flexor muscles atrophy and the size of the forearm is much reduced. There will also be impairment of the functions of sensation and motion in the hand, which will be alluded to later. Operations. — To find the nerve in the ^Lpper third of the forearm an incision may be made at the inner side of the biceps tendon and brachial artery. The median- nerve will be found to the inner side of the artery and may be followed down. When the pronator radii teres is reached it must either be drawn to the ulnar side or divided. The fascial expansion covering the flexor sublimis is next reached; it must be slit up and the muscular fibres parted to reach the nerve lying between it and the flexor profundus, with the volar (anterior) interosseous nerve alongside. To reach the nerve in the middle third of the forearm the guide should be the palmaris longus tendon. The nerve lies in a line joining the outer edge of the palmaris longus tendon at the wrist and the brachial artery at the inner side of the biceps tendon at the elbow. If an incision is made in the middle of the forearm one comes down on the belly of the flexor carpi radialis muscle and it is necessary to part its fibres as well as those of the flexor sublimis beneath. If one goes a little lower down and places the incision between the palmaris longus and flexor carpi radialis the latter may be drawn outward, but the fascia covering the flexor sublimis will still have to be incised. The comes nervi mediani artery will be found accompanying the nerve. tendon of the palmaris longus or between it and the flexor carpi radiaHs. The incision should be made between the muscles. A layer of deep fascia will be found beneath them, which must be incised. From this point the nerve can be followed up beneath the flexor sublimis or downward beneath the annular ligament. Care is to be taken not to disturb the tendons of the flexor sublimis at the wrist. The Ulnar Nerve. — The ulnar nerve passes downward in the groove on the back of the medial (internal) condyle and between the condyle and olecranon process. It passes between the two heads of the flexor carpi ulnaris muscle and is covered by it, lying on the flexor profundus digitorum ; when half way down the forearm it becomes superficial and lies under or at the edge of the flexor carpi ulnaris muscle with the ulnar artery and flexor sublimis muscle to its outer or radial side. The ulnar artery joins the nerve just above the middle of the forearm. Just below the elbow the artery gi\'es off the posterior ulnar recurrent branch, which passes up with the nerve behind the medial condyle. From the middle of the forearm to the wrist the ulnar nerve lies behind and to the ulnar side of the artery. Brayiches. — It gives muscular branches in the upper third of the forearm to the flexor carpi ulnaris and ulnar half of the flexor profundus digitorum muscles. It gives small articular branches to both the elbow-joint and wrist-joint. It also gives oft anterior and posterior cutaneous branches. The anterior, one or two, come off about the middle of the forearm ; one supplies the anterior surface of the ulnar side of the forearm, while another, called the palmar cutaneous, runs down the front of the artery to be distributed to the palm. The dorsal or posterior cutaneous branch is given oft' about 5 cm. (2 in.) above the wrist and passes downward and backward beneath the tendon of the flexor carpi ulnaris, across the interval between the pisiform bone and styloid process of the ulna, over the tendon of the extensor carpi ulnaris, and thence to the fingers. Wounds. — This nerve in the forearm is not infrequently wounded. It is especially liable to injury in resecting the elbow-joint. From what has been said of its course and branches it will be seen that in order for paralysis of any of the muscles of the forearm to be produced it must be injured high up in its upper third. Then the flexor carpi ulnaris and inner half of the flexor profundus digitorum will be paralyzed. If injured lower down the only muscular paralysis which will ensue is that of the short muscles of the hand which it supplies. If the nerve is divided above the middle of the forearm the anterior cutaneous nerves will be involved. If divided between that point and 5 cm. above the wrist the anterior cutaneous escapes but the dorsal cutaneous branch is paralyzed. Below this latter point the dorsal cutaneous branch escapes and the muscular and sensory disturbances produced are on the palmar surface (except the dorsal interossei muscles). Operations. — In all operations on the nerve it should be remembered that its course is a straight line from the medial condyle to the radial edge of the pisiform bone. In the lower half of its course it lies along the outer (radial) edge of the flexor carpi ulnaris and this tendon will serve as a guide to it. It is here covered only by skin and superficial and deep fasciae, though it may be overlapped by either the artery or the edge of the tendon. If it is desired to reach the nerve in its upper half it can be followed either from abo\-e downward or from below upward, the fibres of the flexor carpi ulnaris muscle which cover it being split to the extent necessary for proper exposure. Below the middle of the forearm the ulnar artery lies to its radial side. Near the elbow the posterior ulnar recurrent artery accompanies it upward, but the nerx-e is far removed from the ulnar artery in this part of its course. The Volar Interosseous Nerve and the Superficial and Deep Branches of the Radial (Musculospiral j. — In addition to the large nerve-trunks of the median and ulnar the forearm contains the volar (anterior) interosseous, and the deep and superficial branches of the radial (musculospiral) nerve. The volar {anterior) interosseous nerve leaves the median opposite to or below the bicipital tubercle of the radius ; it lies on the interosseous membrane to the ulnar side of the accompanying volar interosseous artery. It supplies the outer half of the flexor profundus digitorum and the flexor longus pollicis muscles, between which it lies, and the pronator quadratus muscle. It is rarely wounded alone. The deep and superficial branches are the continuation of the radial ('musculospiralj which divides in the groove between the brachioradialis (supinator longus) and brachialis anticus muscles just above the elbow. The deep branch {posterior inferosseoics ) is the larger and is a muscular ner\'e ; the superficial branch (radial; is smaller and is solely sensory. The deep branch passes down under the brachioradialis and extensor carpi radialis longior and brevior muscles and then enters the substance of the supinator (brevisj through which it passes to supply the extensor muscles on the back of the forearm and terminates in a gangliform enlargement on the back of the wrist. It supplies all the muscles on the back of the forearm except the anconeus, brachioradialis, and extensor carpi radialis longior, which are supplied directly from the radial (musculospiral) ner\-e. In removing the head of the radius, in resection of the elbow, the supinator Tbrevis j is to be carefully raised from the bone so as to carry the nerv^e with it and a\'oid injuring it. Injury to this nerve causes paralysis of the extensors, and wrist-drop follows. It passes down almost in a straight line and lies to the outer side of the radial artery at the junction of its upper and middle thirds. It lies alongside of the artery to its outer side in its middle third and then, about 7 or 8 cm. (3 in.) above the wrist, quits the arter)', passes beneath the tendon of the brachioradialis, and divides into two branches which supply sensation to the dorsal (radialj side of the hand and fingers (Fig. 374, p. 36 1). Fractures of the forearm may involve either the radius or ulna, or both. The radius is the bone most often broken. The preservation of the interosseous space and functions of pronation and supination are prominent points in treatment. Fractures of Both Bones.— These fractures occur either from a direct blow on the part or are due to violence in falling on the outstretched hand. They usuallv occur in the middle or lower third. The character of the displacement depends more on the manner in which the injury is produced than on the action of the muscles, though in some cases they also have some influence. The main function of the forearm in addition to that of ser\ang as a pedestal or support for the hand is to perform the movements of pronation and supination. It is these movements that are most apt to be impaired in cases of fracture. When both bones are fractured the interosseous membrane still remains, running transverselv from one bone to that of the opposite side. Therefore, while it is common enough to find the fractured ends displaced toward one another, thus narrowing or obliterating the space between them, one never sees a displacement of the fragments producing a widening of the interosseous space. In fracture of both bones four types of deformity or combinations of these types are found. 1. The fractured ends of the distal or proximal fragments may preser\'e approximately their normal position to one another but be displaced either anteriorly or posteriorly or else to one side. When this is the case the displacement is one simplv of overlapping. If the fragments are displaced laterally from one another then the tension of the muscles draws the fragments together and causes them to overlap. There is no special direction which this displacement may take. The lower fragments may be either in front or behind or to either side of the upper ones. The position of the fragments varies according to the direction of the fracturing force. This displacement is to be remedied by traction on the hand to o\'ercome the muscles and bring the broken ends opposite one another, and then by direct pressure pushing them as completely as possible back into their normal position. The shafts of both bones have muscles arising from them on both their anterior and posterior surfaces and the sharp fractured ends of the bones not infrequently get stuck in the muscular fibres and so pre\-ent proper approximation; non-union mav be produced by this cause. the bones are intact they rest on one another at their ends, leaving a space between across which stretches the interosseous membrane. The action of this membrane in preventing a separation of the fragments has already been pointed out, and the influence on the fragments of pronation and supination will be discussed further on. The two bones, — radius and ulna, — traverse the forearm from the elbow to the wrist like two bridges, when they are broken they naturally fall inward toward one another. This approximation of the fragments is aided by the muscles, particularly the pronators and the brachioradialis. The pronator quadratus and teres both pass from the ulna to the radius, the one at the lower and the other at the upper portion of the forearm. When they contract they naturally tend to draw the bones toward one another. The brachioradialis, arising from the lateral (external) supracondylar ridge of the humerus and inserting into the base of the styloid process of the radius, by its contraction tends to tilt the upper end of the lower fragment toward the ulnar side. Pressure on the bones by bandages wound around the part likewise causes them to encroach on the interosseous space, hence the desirability of splints which are wider than the forearm so that lateral pressure on the bones by the bandages is prevented. 3. The fragments may be rotated on one another in the direction of pronation or supination and, becoming united m this misplaced position, render the normal movements of rotation either much restricted or altogether impossible. This axial rotary displacement is due either to the lower fragments being dressed in a position of pronation or to muscular action. As has already been pointed out (see movements of pronation and supination, page 314), in performing the movements of pronation and supination the ulna is the fixed bone and the radius is the movable one. When the hand is pronated the radius crosses the ulna obliquely and lies almost or quite in contact with it, thus obliterating the interosseous space. When the hand is in a position of middle or full supination the bones are widely separated. When fractures are treated in the prone position it is recognized that the callus may bind the bones together in their approximated condition and a loss of motion will result. This is one reason why it is always required to treat these fractures with the hand midway between supination and pronation or in complete supination, in which position the bones are widely separated. The influence of the supinator muscles, as was pointed out by Lonsdale, is also important. As has already been stated, the supinators are stronger than the pronators. When the fracture occurs above the insertion of the pronator radii teres the upper fragment is rotated outward by the biceps and supinator (brevis). There are no muscles to oppose them. On this account it is necessary to dress the fracture with the hand supinated. When the bones are broken below the middle of the forearm the pronator radii teres remains attached to the upper fragment and tends to oppose the supinating action of the biceps and supinator (brevis). Therefore the fracture is treated with the hand midway between pronation and supination. A diminution or loss of the power of pronation and supination is a common sequel of fractures of the forearm and is due either to an interference with the movement of the bones by callus or displaced fragments or by supination of the upper fragment. It is favored by treating the arm in an unfavorable position. 4. The fragments may be inclined toward one another, producing an angular deformity. Simple bending at the site of injury produces this displacement. It is liable to occur if a narrow band or sling is used to support the injured member. If the hand is supported by the sling the arm sags at the seat of fracture. If the forearm is supported at the site of fracture the hand falls and an angular deformity again occurs. Treatment of the fracture with the hand in a supine position on a splint with a long sling reaching and supporting the entire length of the forearm will obviate and prevent the deformity. Fractures of the Shaft of the Radius. — Fractures of the shaft of the radius are not common. They are j^roduced by both direct and indirect injury. The hand is attached to and articulates mainly with the radius, so that in falls on the hand the force is transmitted to the radius, and the shaft of the bone is not infrequently fractured in this manner. These fractures are of interest from an anatomical point mainly on account of the influence of rotation and muscular action in displacing the fragments. The forearm possesses the movement of rotation; the radius is the movable bone and rotates around the ulna, hence when it is broken its fractured ends are readily displaced. Fractures of this bone are to be treated with the hand in half or full supination because in these positions the interosseous space is preserved. In pronation the radius crosses the ulna obliquely and lies close upon it and is then most liable to be bound to it by callus. A certain amount of callus or deformity may occur without interfering with the ulna opposite. It should also not be forgotten that most muscles have more than one action. The biceps is both a flexor and supinator. The brachioradialis flexes, supinates, and exerts a directly upward traction on the outer surface of the lower end of the radius. The fractures of the shaft of the radius may be divided into those abo\'e and those below the insertion of the pronator radii teres. This muscle inserts by a comparatively small tendon into the outer and posterior surface of the middle of the radius. Fractures above the Insertion of the Pronator Radii Teres. — When the bone is fractured above the pronator radii teres insertion, and below the tubercle, the upper fragment is drawn forward and rotated outward by the biceps. If the fracture is down close to the upper edge of the insertion of the pronator radii teres the supinator (brevis) will assist in the supination. The lower fragment will be pronated by the pronator radii teres and quadratus. It will be drawn toward the ulna by the teres, quadratus, and also by the action of the brachioradialis. The pronator radii teres will also tend to draw the lower fragment anteriorly. The injury is to be treated with the elbow flexed to relax the biceps and in a fully supinated position (Fig. 332). Fractures below the hisertion of the Pronator Radii Teres. — When the fracture is below the insertion of the pronator radii teres and above the pronator quadratus we have the lower fragment The upper fragment is displaced anteriorly by the flexing action of both the biceps and pronator radii teres. The supinator (brevis) and biceps both tend to supinate it and the pronator radii teres to pronate it. This tends to place the upper fragment Pronator quadratus Fig. 332. — Fracture of the shaft of the radius above the insertion of the pronator radii teres muscle. The upper fragment is rotated outward by the biceps and supinator muscles. midway between pronation and supination. All fractures of the radius are to be treated with the elbow flexed to relax the biceps muscle. It is to be marked that the position of the lower fragment follows the position of the hand in pronation and supination. Also that by bending the hand toward the ulnar side the lower fragment tends to be tilted awav from the ulna and thus the interosseous space is increased. Fig. 33.?. — Fracture of the radius iust below the insertion of the pronator radii teres muscle. The upper franment is displaced directly forward in a position midway between pronation and supination. p,Q 33 J — Fracture below the middle of the shaft of the ulna, the lower fragment drawn toward the radius by the pronator quadratus muscle. osseous space and to some extent to counteract the action of the brachioradialis. On account of the upper fragment assuming a middle position the _ fracture is dressed in this position with the thumb upward— an internal angular splint is used. Some surgeons prefer using the position of full supination. ■ ■ t u The "difference in the width of the interosseous space when the hand is in full supination and when it is in semisupination, though it may be slighdy m favor of the latter position, is too little to give it any preference on that account. Fractures of the Shaft of the Ulna. — The shaft of the ulna is more often broken by direct violence than is the shaft of the radius. When the arm is raised to ward off a threatened blow the thumb is toward the body and it is the ulna which is presented externally to receive the impact of the blow, hence its more frequent injury. There are two main sites of injury, one just below its middle and the other a short distance below the elbow-joint, about at the junction of its middle and upper thirds. The former results from the fact that the bone below the middle is smaller and weaker than it is above and is not so well covered by muscles. Fractures jiist Beloza the Middle of the Shaft of the Ulna. — The bones of the forearm act as props to separate the hand and elbow. The hand is attached to the radius and the radius rests on the capitellum of the humerus, therefore even when the ulna is fractured as long as the radius and attachments of the hand are intact there is usually but little overlapping of the fragments. The upper fragment articulating with the humerus by a pure hinge-joint cannot be displaced laterally, but the radius and hand can move bodily toward the ulna, being favored in so doing by the pronator radii teres. Thus it is seen that both obliterate the interosseous space and interfere with rotation. As to whether the lower or upper fragment will be nearer to the radius will depend upon the direction of the line of fracture. If this is from within downward and outward, as is the more usual, then the lower fragment will be to the radial side of the upper one. The treatment of fractures in this locality should be with the hand placed in the position of full supination. Hamilton ("Fractures and Dislocations,'" page 319) stated that he had three times seen supination lessened in this injury but never pronation. The ulna is to be pushed away from the radius by pressure made between them with the thumb and fingers and the hand bent toward the radial side. Fracture at the Upper Third. — The radius articulates with the upper end of the ulna in the lesser sigmoid cavity. Immediately below this is a depression in the ulna called the bicipital hollow, intended to accommodate the bicipital tubercle when the forearm is pronated. At this point the bone is slightly narrowed and then widens again toward the middle. This constricted part is 7 or 8 cm. (3 in.) below the tip of the olecranon process and the spot where fracture is likely to occur. When fracture does occur here, if displacement is marked, it produces characteristic lesions. The upper fragment may be displaced either posteriorly or anteriorly. The carrying angle (page 282) formed by the Hne of the arm with the hne of the forearm, depends on the integrity of the humerus and ulna and their proper articulation. If the ulna is broken high up the forearm is deprived of its support on the inner side and it sags inward, thus approximating the bones, obliterating the interosseous space, and diminishing the carrying angle. In treatment care should be taken that the forearm be not allowed to incline toward the inner side. Displacement Posterior. — Wh^n the displacement is posterior the lower end of the upper fragment is tilted backward by the contraction of the triceps muscle. This causes a marked projection on the back of the forearm below the dbow (Fig. 335). In treating this injury the forearm should be placed in at least partial extension (complete extension is usually not necessary) so as to relax the triceps muscle. Displacement Anterior. — When a person recei\'es a blow in the region of the junction of the upper and middle thirds of the ulna on its posterior surface the fragments are pushed forward and an angular deformity is produced, the apex of the angle pointing toward the anterior surface. The force of the blow is not expended entirely on the ulna but, having broken it, continues and pushes or dislocates the radius forward (Fig. 336). In these injuries the fracture of the ulna is readily recognized, but the dislocation of the head of the radius is often overlooked. If the dislocation is not reduced subsequent flexion of the elbow will not be possible much if any beyond a right angle. The contraction of the biceps not only favors this luxation by pulling the radius forward but tends to cause it to recur after replacement. Reduction is to be attempted by supinating and flexing the forearm to relax the biceps and making direct pressure anteroposteriorly on the radius to force the head back into place. The radius may be kept in place by dressing the arm with the elbow in a position of complete flexion. Fig. 336. — Fracture of the upper third ot the ulna, with anterior angular displacement of the fragments and anterior dislocation of the head of the radius. The lower half of the forearm is so largely tendinous that musculocutaneous flaps are unsuitable ; by the time the tendons are cut short there is little tissue left but skin, superficial and deep fascia, and a few muscular fibres. Amoutation should be performed as low down as one can so as to save as much as possible. Artificial appliances, so useful in the lower extremity, are, practically, of little value in the upper. The preservation of the power of pronation and supination is to be accomplished when the condition permits. The pronator radii teres has its insertion in the middle of the radius and if the division of the bone is below that point rotary movements will be preserved. The surgeon should be acquainted with the position of the main arteries and nerves. Four arteries will require ligation : the radial, ulnar, volar (anterior), and dorsal (posterior) interosseous. Their position as well as that of the nerves will vary accordingly to the site of the amputation. The median and ulnar are the only nerves that require shortening. The forearm may require to be operated on for disease or injuries of the bones, tumors, foreign bodies, wounds, etc. In operating on this region of the body it is to be constantly borne in mind that it contains a multitude of structures each of which is essential to the proper performance of some special function. Injury to these structures is followed by a corresponding functional disability. Attempts at brilliant operating are out of place and the surgeon should be exact, careful, and ev^en tender in his handling of the various structures. radial and ulnar pass through it to nourish the hand. These latter are to be avoided. The nerves that supply the forearm are given of? high up near the elbow, hence they are not usually in danger of injury. The median, ulnar, and superficial branch of the radial nerve pass to the hand and they, if possible, are to be avoided. It is therefore evident that as far as the arteries and nerves are concerned operations in the lower part of the forearm are less dangerous than those in the upper. With the muscles it is just the opposite. In the lower half the muscles become tendinous and soon form groups or masses of tendons. These tendons are separated by thin connective-tissue sheaths or synovial membrane which allow them to move freely as the muscles contract. Any interference with these sheaths or their contents causes an outpouring of inflammatory material that binds them together and fetters their action. As healing takes place contraction sets in and the patient is left with a useless claw-like hand. For these reasons large incisions and displacements and interference with tendons are to be avoided whenever possible. As the muscles mostly run longitudinally the incisions should also be longitudinal. Division of the superficial veins is not liable to cause trouble, but the large radial, median, or ulnar veins on the anterior surface may be plainly visible and then the incision should be made so as to avoid wounding them. The only superficial nerve to be so avoided is the superficial branch of the radial. It is alongside of the radial artery in its middle third, but about 7 or 8 cm. (3 in. ) above the wrist it leaves the artery and winds under the brachioradialis to go" down the outer and posterior surface of the radius. It is here to be looked for and avoided, as it furnishes sensation to the thumb, index, middle, and half of the ring fingers. If it is desired to penetrate the muscles their direction is to be remembered. The superficial flexor muscles arise from the internal condyle, hence the incision should point upward toward it. The direction of the pronator radii teres is from the internal condyle to the middle of the radius. The deep flexors are parallel with the bones. Posteriorly the extensor group of muscles tends toward the external condyle. A third group on the radial side comprises the brachioradialis and the extensor carpi radialis longior and brevior. The tendon of the first lies on the outer surface of the radius with the other two immediately posterior to it. Crossing the posterior and outer surface of the radius in its lower third are the extensor ossis metacarpi pollicis and extensor brevis pollicis tendons. If it is desired to reach the bones the ulna can be exposed posteriorly where it is subcutaneous in its entire length by an incision between the flexor carpi ulnaris and extensor carpi ulnaris. The deep fascia is attached to the bone at this point. If it is desired to expose the radius, H. Morris ( Clin. Soc. Titans., vol. x, p. 138) has advised going in between the brachioradialis and the extensor carpi radialis longior. He used the superficial branch of the radial nerve as a guide to the desired interspace. If an incision were made upward from the outer surface of the styloid process of the radius one would first encounter the tendons of the extensor brevis pollicis and extensor ossis metacarpi pollicis muscles. These being displaced posteriorly would reveal the brachioradialis tendon crossing from beneath the posterior border of the radius; 5 to 7 cm. (2 to 3 in.) above the styloid process would be the superficial branch of the radial nerve. Following the nerve and edge of the brachioradialis tendon would lead to the interspace between it and the extensor carpi radialis muscle posteriorly. When the middle of the forearm was reached the insertion of the pronator teres would be encountered, and from that point up the bone would be covered by the supinator Tbrevisj. In operations involving the upper third of the radius the deep branch of the radial (posterior interosseous) ner\'e is liable to be wounded as it passes through the supinator (brevis) muscle. It is best avoided by elevating the muscle from the bone and raising the nerve along with it, for it does not rest immediately on the bone but has some muscular fibres intervening. PUS BENEATH THE DEEP FASCIA. The deep fascia of the forearm is continuous with that of the arm. It forms a complete covering for the muscles and sends septa between them. It is especially strong posteriorly. It is attached to the medial and lateral condyles of the humerus, the sides of the olecranon process and the whole length of the ulna posteriorly. Below the medial condyle anteriorly it is strengthened by the bicipital fascia. In the antecubital fossa it is pierced by a large communicating vein which connects the superficial and deep veins. Toward its lower end posteriorly, it is strengthened by transverse fibres and becomes attached to the longitudinal ridges on the radius and blends with the posterior annular ligament. Below anteriorly it is thin and forms a covering for the tendons of the palmaris longus and flexor carpi radialis muscles and at the wrist blends with the annular ligament beneath. This latter, as pointed out by Davies Colley ("Morris's Anatomy," page 311;, is a continuation of the layer of fascia covering the flexor sublimis digitorum. When infection involves the deep tissues of the forearm the pus, being hindered from going externally by the fibrous septa between the various layers of muscles as 'well as the deep fascia itself, tends to burrow up and down the arm. If in the upper portion of the forearm, it tends to point in the antecubital fossa. If lower down, it tends to come to the surface on the radial side between the flexor carpi radialis and brachioradialis or toward the ulnar side between the palmaris longus and flexor carpi ulnaris. The three structures, — the tendons of the palmaris longus and flexor carpi radialis and the median nerve, — form a solid barrier anteriorlv which inclines the pus to one side. Above posteriorly it may w'ork its w^ay upward behind the internal condyle, following the ulnar nerve. The fibrous septa of the various muscles hinder the progress of pus laterally, and the attachment of the deep fascia to the ulna prevents its passing around the arm at that point. The many pockets formed by the pus in its burrowing between the muscles render these abscesses dilftcult to drain and tedious in healing. Should infection from the thumb travel up the flexor longus poUicis tendon, when it reaches above the wrist it is directly beneath the tendon of the flexor carpi radialis. In such a case an incision should be made along the radial (outer) edge of the tendon, taking care not to wound the radial artery still farther out. If pus infects the forearm by following up the flexor tendons of the fingers beneath the anterior annular ligament, it shows itself above the wrist between the palmaris longus and flexor carpi ulnaris tendons and can here be incised. If it is desired to introduce a drain beneath the flexor muscles, an incision mav be made along the side of the ulna and a forceps passed under the flexor tendons and made to project under the skin of the radial side where a counter opening can be made and the drain inserted. (For a discussion of the treatment of purulent affections of the hand and forearm see A. B. Kavanel : "Surgery, Gynecology, and Obstetrics," 1909, p. 125, vol. viii. No. 3.) Suppuration around these tendons is very serious, as the effusion binds together the tendons and irritates the nerves and produces disabling contractures which are exceedingly difficult to remedy. By the wrist is meant the constricted portion of the upper extremity by which the hand is joined to the forearm. We will include in its consideration the lower portion of the forearm for about 4 cm. (lYz in.) above the radiocarpal joint, and the joint itself. The wrist is so constructed as to permit of the movements of pronation and supination of the bones of the forearm, to serve as a support for the hand, and to allow movements of the hand in various directions. Of the bones of the forearm — the radius and ulna — we have seen that at the elbow the ulna is the larger of the two. This is because the main function of the ulna is to act as a support to the parts beyond. The radius is intended mainly as a means of enabling the hand to perform the functions of pronation and supination. At the wrist we find the radius supporting the hand and consequently its lower end is large and well developed. The ulna, on the contrary, contributes but little to the support of the hand and does not even enter directly into the wrist-joint, as does the radius at the elbow-joint, but serves as a fixed point around which the radius rotates. The functional value of the ulna at the wrist is so much less than that of the radius as amply to account for its diminished size. Lower end of the Radius. — The lower end of the radius is large and spongy. The compact tissue forms a quite thin superficial layer (Fig. 33S). Its anterior surface is hollowed out to receive the pronator quadratus muscle, with a prominent articular edge to which is attached the anterior ligament (Fig. 339). The posterior surface is convex and marked with a number of ridges with grooves between them which lodge the extensor tendons (Fig. 340). In its middle is a prominence, the dorsal radial tubercle, which marks the position of the extensor longus pollicis muscle. On its inner side is a concave articular facet, the idnar notch {sigmoid cavity^, for articulation with the ulna; it is plane from above downward, thus showing that it permits movement in one direction only, like a hinge. The lower or radiocarpal articular surface slopes downward and outward to end in the styloid process, which is thereby placed lower than the styloid process of the ulna. The articular surface is divided into two facets: the outer is the smaller, is triangular in shape, and articulates with the navicular {scaphoid) bone; the inner or larger is quadrilateral and articulates with the Innate {semilunar) bone. The styloid process at its base or upper outer portion has inserted into it the tendon of the brachioradialis muscle. To its tip is attached the external lateral ligament. _ The Ulna. — The lower extremity of the ulna is rounded in shape, forming its head, with the styloid process projecting downward on its inner and posterior aspect To its tip is attached the internal lateral ligament. On its outer side is a rounded smooth surface for articulation with the ulnar notch of the radius. The inferior or articular surface is flat and rests on the flat interarticular fibrocartilage. The navicular (scaphoidj, lunate (semilunar), cuneiform, and pisiform bones form the first row of the carpal bones. The pisiform rests on the anterior surface of the cuneiform and does not enter into the articulations between the hand and bones of the forearm. the upper surface of the triangular fibrocartilage. This latter is attached by its apex to a depression on the outer side of the root of the styloid process of the ulna, and by its base to the rough line on the radius separating the radio-ulnar from the radiocarpal articulation (Fig. 34 O. The Interarticular Triangular Fibrocartilage. — This serves as the main bond of union between the lower ends of the radius and ulna. It is strong and blends with the internal lateral ligament. Thus the hand has an attachment to the inner side of the radius by means of the internal lateral ligament and triangular cartilage. The Capsular Ligament. — The capsular ligament serves to retain the synovial fluid in the joint. It is thin and filmy and possesses no strength, and therefore is useless in limiting movements. strong enough to be efficient in limiting movements of the bones. Movements. — As has already been pointed out T page 304) the movements of pronation and supination have as their axis a line drawn through the middle of the head of the radius, the styloid process of the ulna, and the ring finger. They embrace in ordinary use a range of about 140 degrees which can be increased by forced effort to 160 degrees (Fig. 342). These movements are limited by various factors, the most prominent being in pronation the contact of the soft parts and bones, as the radius obliquely overlies the ulna, and in supination by the biceps (the most powerful of the supinators) having reached the dead centre. There is no communication between the radio-ulnar joint above and the radiocarpal joint below, except when, as occasionally happens, the triangular cartilage has a perforation. During pronation and supination the lower end of the radius moves with the hand, but the lower end of the ulna remains at rest: hence it is that the styloid process of the radius always retains the same position in relation to the hand. When it is desired to identify the styloid process of the radius, one needs only to follow the metacarpal bone of the thumb up to the snuff-box at the upper edge of which the styloid process can always be felt. Also, to identify the styloid process of the ulna, one must not use the hand as a guide because the hand changes its position in relation to the ulna; but, as the ulna remains quiet, its styloid process can be found by following the posterior surface down to its extremity. As the interarticular triangular cartilage is fastened by its base to the ulnar edge of the radius and by its apex to the base of the styloid process of the ulna, it travels with the hand in the pronation and supination. The wrist-joint is formed by the radius and triangular cartilage above and the navicular (scaphoid), lunate (semilunar), and cuneiform bones below. These are joined by the anterior, posterior, internal and external lateral, and capsular ligaments. The two lateral ligaments are strong, well-defined bands, the anterior and posterior ligaments are weaker and are fused with the capsular ligament. The internal lateral ligament is attached above to the tip of the styloid process of the ulna and the tip of the triangular cartilage ; below it is attached to the border of the cuneiform bone and is continued on to the pisiform bone. process of the radius and below to the base of the tubercle of the navicular bone. The capsular ligament of the wrist-joint is composed of an anterior and a posterior portion strengthened by the two lateral ligaments just described. The anterior ligament has the bulk of its fibres running downward and inward from the edge of the radius to the palmar surface of the navicular, lunate, and cuneiform bones. It is stronger than the posterior. The posterior ligament likewise has its fibres running downward and inward to be attached to the first row of carpal bones. Movements.- — The wrist is classed as a biaxial diarthrosis or condyloid joint. This means that it is a double hinge-joint having movements around two axes, one anteroposterior and the other transverse. A combination of these movements results in circumduction, but it has at least no voluntary movement of rotation. When rotation of the hand occurs it is accompHshed by pronating or supinatingthe forearm. If the wrist-joint posssssed this latter movement it would be a balland-socket or enarthrodial joint. The hand can be flexed and extended through an arc of approximately 140 degrees and adducted and abducted about half as much. The position assumed by the bones in flexion and extension is shown in Figs. 343 and 344. _ accounts, at least in part, for this. The lateral ligaments check the movements of abduction and adduction, and in addition the contact of the styloid process of the radius with the trapezium prevents further outward movement. The extent of the movements of the wrist of course varies much in different individuals. The laxness of the joints in children, women, and those not accustomed to hard manual labor is well known. and extensors of the thumb and fingers. The first set is composed of the flexor carpi radialis and flexor carpi ulnaris, with which we may perhaps include the palmaris longzis, — although it properly belongs with the finger muscles, — and of the extensor carpi tdnaris, extensor carpi radialis longior, and extensor carpi radialis brevior. If the fingers are clinched and the extensors of the fingers contract they aid the three carpal extensors to bend the hand backward. If the fingers are held extended and the flexors of the fingers contract they aid the carpal flexors to bend the hand forward. Contraction of the flexor and extensor carpi ulnaris adducts the hand and contraction of the flexor carpi radiaHs and extensor carpi radiahs longior and brevior, aided by the short extensor of the thumb and extensor ossis metacarpi polHcis, abducts the hand. In the affection known as wrist-drop all the extensor muscles are paralyzed. It is due to injury, usually from pressure on the radial (musculospiral) nerve, either in the groove of the humerus or in the axilla. Although there are a number of synovial bursae around the joint in connection with the tendons none communicate with it. Muscles. — The flexor tendons cover the wrist anteriorly and the extensors posteriorly. With the flexor group we may consider the pronator quadratus. A third or radial group comprises the extensor carpi radialis longior and brevior and the brachioradialis. Anteriorly. — The tendons on the front of the wrist occupy four different planes or levels. The most superficial layer embraces the flexor carpi radialis, the palmaris longus, and the flexor carpi ulnaris. Of these three the palmaris longus is the nearest to the skin as it inserts in the palmar fascia in front of the annular ligament. The flexor carpi radialis slips under the upper portion of the annular ligament to insert into the base of the second metacarpal bone. The flexor carpi ulnaris inserts wrist, hence the desirability of being able to recognize and locate them. The Deep Fascia and Anterior Annular Ligament. — The deep fascia covering the anterior muscles of the forearm is comparatively thin. As it approaches the wrist it divides into two layers. The superficial layer is thin and runs o\-er the tendons of the palmaris longus and flexor carpi radialis muscles and the ulnar artery and nerve. It is continuous below with the palmar fascia. To the ulnar side it passes over the flexor carpi ulnaris muscle to be continuous with the posterior annular ligament. It is not attached to the ulna, but slides over it as it follows the move^ ments of the hand in pronation and supination (Fig. 345). The deep layer of the deep fascia covers the flexor subUmis digitorum and passes downward' beneath the flexor carpi radialis and brachioradialis muscles. It is continuous below with the anterior annular ligament. The deep layer blends with the superficial layer to the radial side of the flexor carpi radialis, and then merges with the posterior annular ligament to form the sheath of two of the extensor muscles of the thumb. terior annular ligament. The anterior annular ligament is attached on the ulnar side to the pisiform bone and unciform process of the unciform bone and on the radial side to the trapezium and tuberosity of the navicular (scaphoid). Over the anterior annular ligament pass the ulnar artery and nerve, ■ Braciiioradiaiis (supinator longus) the Superficial vokr artery, and the nerve. Beneath the annular ligament pass the median nerve, the flexor sublimis, flexor profundus, and flexor longus pollicis tendons. These tendons are embraced in two sheaths, one for the flexor longus poUicis and the other for the flexors of the other four fingers, the sheath for the little finger extending to the insertion of the profundus tendon into the distal phalanx. The tendinous sheaths accompany the tendons for a distance of 2.5 to 5 cm. (i to 2 in.) above the annular ligament. Posteriorly. — On the posterior surface of the . wrist the tendons may be divided into two groups, an extensor group and a radial group. The extensor group is divided into a superficial and deep set. The superficial set is composed of the extensor communis digitorum, the extensor minimi digiti and the extensor carpi ulnaris. The deep set is composed of the extensor ossis metacarpi poUicis, extensor brevis poUicis, extensor longus pollicis, and extensor indicis. The radial g7'oiip, on the posterior and outer surface of the radius, is composed of the extensor carpi radialis longior, the extensor carpi radialis brevior, and the brachioradialis (Fig. 346). The first two lie beneath the deep extensor muscles, thus practically forming a third layer. All the tendons of the posterior and radial group of muscles, with the exception of the brachioradialis, pass beneath the posterior annular ligament into the hand. The brachioradialis inserts into the base of the styloid process of the radius. Posterior Annular Ligament. — As the tendons pass down over the posterior surface of the radius and ulna they are bound down by processes of the deep fascia which form canals in which they run. The deep fascia of the posterior surface of the forearm in the neighborhood of the wrist is strong, and forms the posterior annular ligament. Its lower border is about level with the upper border of the anterior annular ligament. It is attached externally to the posterior and outer edge of the styloid process of the radius and internally to the posterior surface of the styloid process of the ulna, the internal lateral ligament, the pisiform, and adjacent carpal bones. Beneath this posterior annular ligament are six compartments. From the radial toward the ulnar side they are : (i) One on the outer side of the styloid process of the radius for the extensor ossis metacarpi pollicis and extensor brevis pollicis; (2) for the extensor carpi radialis longior and brevior, then comes the posterior radial tubercle in the middle of the radius, and passing close along its ulnar side is (3) the extensor longus pollicis. To the ulnar side of this tendon is a comparatively broad sheath for (4) the extensor communis digitorum and the extensor indicis muscles. In the interval between the radius and ulna lies (5) the tendon of the extensor minimi digiti, and on the posterior side of the styloid process of the ulna is (6) the tendon of the extensor carpi ulnaris (Fig. 347). Each of these six compartments is lined with a separate sheath which extends under the annular ligament from a centimetre or two above the joint to about the bases of the metacarpal bones on the dorsal surface of the hand. The Anatomical Snuff-Box (la tabatiere anatomique, of Cloquet"). — On the outer dorsal aspect of the wrist, just below the radius, is a depression particularly noticeable when the thumb is abducted (Fig. 351, page 341). It is triangular in shape with its base upward. The styloid process of the radius forms its base ; the extensor brevis polhcis with the extensor ossis metacarpi poUicis forms its radial or outer side, and the tendon of the extensor longus polhcis forms its ulnar or inner side. Its floor is formed by the navicular (scaphoid) and trapezium bones. Through it, lying on these bones and the external lateral ligament, passes the radial artery on its way to the first interosseous space. Superficial to the artery lies a vein and some fine branches of the radial nerve. In ligating the artery at this point, The bellies of many of the muscles, mainly the superficial ones, cease as they become tendinous about the middle of the forearm. Hence the rapid decrease in size as one descends. When the wrist is reached there is a swelling on each side caused by the expanded lower end of the radius on the outer side and the head of the ulna on the inner. The medial Tinner) prominence is rendered more marked by abducting the hand, the lateral Touter) prominence by adducting it. Just beyond these there is a constriction as the wrist passes into the hand. REGION OF THE WRIST. 339 Above the wrist on the anterior and outer part can be feh the radius. Its lower 2 or 2.5 cm. ( I in.; is sharp and prominent — this is the anterior border of the styloid process. On the outer side at its base is the point of insertion of the brachioradialis tendon. Following the bone down on its outer side, at the upper margin of the anatomical snuff-box, one feels the tip of the styloid process, a most important landmark. On the outer surface of the radius beginning below between the tip of the styloid process and its sharp anterior border are the extensor ossis metacarpi pollicis and extensor brevis pollicis tendons. They can readily be seen and felt when the thumb is extended as they cross obliquely over the lower end of the radius. The sheaths of these tendons frequently become inflamed from injuries, causing what is termed tenosynovitis . If the hand is laid on the lower portion of the radius of a patient so affected, and he is told to move the thumb, a characteristic creaking can be felt as the tendons move in their inflamed sheaths. The edge of the articular surface of the radius can be indistinctly felt from the tip of the styloid process to the edge of the flexor carpi radialis internally and across the back of the wrist in an upwardly cur^-ed line toward the ulna. On the inner side of the wrist can be felt and seen the prominence made by the head of the ulna. The ulna is subcutaneous and can be followed up the forearm posteriorly its entire length. It is not covered by muscles on its inner border, but on its anterior surface is the flexor carpi ulnaris tendon beneath which is the flexor profundus digitorum, this latter being separated from the bone by the origin of the pronator quadratus. If the posterior surface of the ulna is followed downward the styloid process forming its extremity can be distinctly felt, especially if the hand is placed in the supine position and slightly flexed. Overlying the head of the ulna posteriorly is the tendon of the extensor carpi ulnaris muscle going to the base of the fifth metacarpal bone. This tendon follows the mo\'ements of the hand in pronation and supination, but the styloid process of the ulna, remains stationary. When the hand is pronated the tendon lies to the anterior side of the styloid process, but when the hand is supinated it lies toward its posterior side. This tendon cannot be readily recognized. The inner and posterior surface of the cuneiform bone can be felt immediately below the head of the ulna. Some difficulty may be experienced in distinguishing one from the other; if, however, the hand is abducted and adducted the cuneiform bone can be felt to move while the ulna remains stationary. On the palmar surface of the wrist, immediately below the ulna, can be felt the distinct bony prominence formed by the pisiform bone. The flexor carpi ulnaris inserts into it. About 2 to 2.5 cm. (\ in.; below and to the radial side of the pisiform bone is the unciform process of the unciform bone. It is best detected by laying the ball of the thumb over the spot and making deep pressure with a rolling motion. On the radial side of the anterior surface, directly in line with the tendon of the flexor carpi radialis, is the prominent tubercle of the navicular (scaphoid; bone; a centimetre farther on, in line with the thumb, is the ridge of the trapezium. The anterior annular ligament is attached to its outer surface about 2.5 cm. ( \ in. ; below the styloid process of the radius ; a bony prominence formed by the trapezium marks its junction with the metacarpal bone of the thumb in front. The ability to locate the carpometacarpal joint of the thumb is of importance in reference to the diagnosis of fractures and other injuries. On comparing the two styloid processes it will be seen that the styloid process of the radius extends i cm. (f in. ; lower than that of the ulna. This is best observed with the hand in a prone position. Across the front of the wrist there are two transverse lines. The proximal or upper one corresponds with the radiocarpal joint or wrist-joint. The distal or lower one corresponds with the joint between the two rows of carpal bones and marks the upper edge of the anterior annular ligament. On the posterior surface of the wrist, one-third of the width of the wrist across from the edge of the radius, can be felt a bony prominence. It is the posterior radial tubercle. If the thumb is extended the tendon of the extensor longus polUcis leads directly to the tubercle and lies along its ulnar border. This tubercle marks the middle of the posterior surface of the radius. The radius passes two-thirds across the wrist and the ulna the other third ; by firm pressure the inten,-al between them can be felt. It the hand is firmly clenched and flexed on the forearm the tendons on the anterior surface of the wrist become prominent. The most evident is the palmans longus which though sometimes absent, usually stands out clear and sharp. Lying along its radial border is the tendon of the flexor carpi radialis; between the^^^^^^^^ a lower level lies the median nerve. In front of the uhia and gomg d rectly down ward to the pisiform bone, is the tendon of flexor carpi ulnaris (Fig. 349)- T J^ u^1 ^^""^ ■' ^f ^^^^f ^ the tendon of the flexor carpi ulnaris stands out clearly. In the hollow to Its lateral (outer; side lie the ulnar nerve and artery A rounded muscular swell fills the space between the ulnar artery and the tendon of the oalmaris longus,— It is caused by the flexor sublimis digitorum (see Fio- ..q) It is here that abscesses show when they travel up from the hand & oj /• Between the outer edge of the flexor carpi radialis 'tendon and the anterior outer edge of the radius is a groove in which runs the radial artery. The position of the extensor ossis metacarpi pollicis and extensor brevis pollicis which run together over the outer surface of the radius can best be determined by abducting the thumb and so making these tendons prominent (Fig 351;. In the same manner the extensor longus pollicis tendon can be made prominent and followed to the posterior radial tubercle. By firm pressure the uoper hmits of the tirst and second interosseous spaces can be felt. They mark the bases of the metacarpal bones. The extensor carpi radialis longior passes across the snuff-box to insert into_ the radial side of the base of the second metacarpal bone. The radial artery as it dips down between the first and second metacarpal bones Hes just to Its outer side. Crossing under the tendon of the extensor longus pollicis is the extensor carpi radialis brevior, which proceeds to the top of the second interosseous space to insert into the adjoining sides of the second and third metacarpal bones extensor communis digitorum and extensor indicis muscles. Passing over the head of the uhia to insert into the base of the fifth metacarpal bone is the tendon of the extensor carpi ulnaris. It is best felt just beyond the extremity of the ulna when the hand is drawn toward the ulnar side. It inserts into the base of the fifth metacarpal bone. Fractures of the radius which occur at the wrist possess certain distinct characteristics and were for a long time confounded with dislocations of the wrist. These fractures are generally grouped by modern surgeons under the name of Colics' s fracture. This fracture was first correctly described, according to both Hamilton and Stimson, by Pouteau ("CEuvres Posthumes," t. 11, p. 251, 1783; also Nelaton, " Chirurgie Path.," t. i, p. 739). Mr. Colles, a Dublin surgeon, described the injury most carefully in the Edinburgh Medical and Surgical Journal, April, 18 14, but it is largely due to Robt. W. Smith's "Treatise on Fractures in "the Vicinity of Joints," Dublin, 1847, that the name Colles's fracture has become generally accepted. Mr. CoUes placed the injury lyi inches (about 4 cm.) above the joint. Mr. Smith placed it from }{ in. to i in. (6 to 25 mm.; above the joint. Most recent writers include all fractures within 4 cm. ( I }^ in. ) of the lower edge of the radius under this name, though some few go still higher. When the line of fracture lies more than 4 cm. above the joint it loses the characteristics of a Colles's fracture and partakes of those of fractures of the shaft ; hence we will not go beyond that limit. The line of fracture is most commonly found, as stated by Robt. W. Smith, from 6 to 25 mm. i^Ys^ to i in.) above the joint. It passes almost transversely across the bone or inclines slightly downward to the ulnar side. It also lies nearer the joint on the anterior surface and inclines backward and upward toward the elbow. Hence the direction is from above downward and forward (Fig. 353). The lower fragment is displaced upward and backward on the shaft of the radius. This causes it to be tilted backward so that the articular surface is rotated on a transverse axis more in the direction of the dorsum than normal and the hand is also carried toward the radial side. The dorsal displacement is due to the direction of the violence and not to muscular action. The radial side of the fragment is displaced upward more than the ulnar because the triangular fibrocartilage retains its radio-ulnar attachments. This prevents the ulnar side from rising, while the radial side is pulled up by the radial flexor and extensor muscles. If the fracture is not extremely close to the joint the brachioradialis will pull the lower fragment toward the radial side and up toward the elbow. As the hand is attached to the radius it follows the lower fragment ; the extensor muscles of the thumb, the flexor carpi radialis, and the two extensor carpi radialis muscles all tend to aid the brachioradialis in producing the displacement toward the radial side (Fig. 354). The lower fragment is displaced toward the dorsum and the upper fragment toward the palmar surface. This produces the ' ' silver fork deformity' ' of Velpeau. This dorsal projection is sometimes increased by the presence of the "carpal tumor," a swelling due to effusion almost directly above the joint. The projection of the upper fragment toward the palmar surface and the effusion in the sheaths of the flexor tendons cause a protrusion on the anterior surface of the wrist and a marked increase in the lower anterior radiocarpal crease. To reduce the deformity the upper fragment is firmly grasped with one hand while with the other the hand of the patient is forcibly adducted (toward the ulnar side) and then sharply flexed. This drags the distal fragment down and forward of? of the proximal one. To retain the fragments in position some surgeons use a pistolshaped splint to hold the hand turned toward the ulnar side and place a graduated compress on the palmar surface with its base opposite the line of fracture and its apex upward and another pad on the dorsal surface with its apex downward over the hand. Other surgeons place the hand in a flexed position, allowing it to hang. Separation of the Lower Epiphysis of the Radius. The lower radial epiphysis fuses with the shaft at about the twentieth year ; therefore epiphyseal separation can occur up to that time. The epiphyseal line passes across the bone from the base of the styloid process to the upper edge of the radio-ulnar joint (Fig. 355). The displacement, symptoms and treatment are the same as in Colles's fracture and it is quite possible that many cases diagnosed as Colles's fracture may be epiphyseal separations. Displacement Forward. This fracture, though rare, occasionally occurs, and if union has taken place the deformity is marked and the injury is liable to be diagnosed as a luxation. It has been particularly described by Dr. John B. Roberts ("A Clinical, Pathological, and Experimental Study of Fracture of the Lower End of the Radius with Displacement of the Carpal Fragment toward the Flexor or Anterior Surface of the Wrist, ' ' Phila. , 1 897 ) . On account of the difficulties in diagnosis it is well to examine its anatomical peculiarities. Displacement. — The lower fragment is tilted forward toward the palmar surface of the wrist, carrying the radial side of the hand with it (Fig. 356). Signs. — The line of the radius can be followed and felt to curve at its lower portion toward the palmar surface. The hand descending with the displaced fragment causes a groove to appear across the dorsum from one styloid process to the other. The dorsal surface of the lower part of the forearm is on a higher plane than that of the carpus. As the hand is lower than normal this causes the lower end of the ulna to project much higher than it should. On account of the tension of the extensor carpi radialis longior and brevior the hand is held level with the forearm and does not droop as in Colles's fracture. Displacement to the radial side may or may not be marked. Previous to the use of the X-rays for diagnostic purposes, fracture of the lower end of the ulna was considered extremely rare. Fractures of the ulna above the head resemble practically those of the shaft. Fracture of the styloid process was observed by D. H. Agnew in one case which was followed by deformity. Inasmuch as the deep fascia slides over the ulna it is readily seen that if it is perforated one or other of the fragments may be caught in the rent. This is probably the explanation of the deformity which occurred in Agnew' s case. He advised treatment with the hand bent toward the ulnar side to relax the extensor carpi ulnaris tendon. Fracture of the styloid process of the ulna has been shown by the X-rays to be a more frequent accompaniment of Colles's fracture than was formerly thought to be the case, — it tends to favor displacement of the hand toward the radial side. DISLOCATIONS AT THE WRIST. The dislocations at the wrist may be due to traumatism or may occur spontaneously. There may be either a displacement of the carpus at the radiocarpal joint or of the ulna at the inferior radio-ulnar articulation. These luxations are very rare. It is to Dupuytren that we owe the recognition of the fact that what were previously regarded as luxations of the wrist were really cases of fracture, usually of the radius. True luxations are exceedingly rare ; they may be either backward or forward and are often compound. They are usually the result of great violence and the ends of the radius and ulna in many cases protrude on the palmar or dorsal surface. Backward luxation is the more common of the two. The question of diagnosis is most important in relation to this injury. Many cases which have been diagnosed as luxations afterwards prove to be fractures. In backward luxation the deformity resembles that of CoUes's fracture, with the following differences : the palmar swelling in dislocation extends farther down toward the hand than is the case in Colles's fracture, — this is owing to the displacement occurring at the joint instead of some distance above, as in fracture ; in luxation the protrusion forming the hump on the dorsal surface has an abrupt upper edge which is lacking in cases of fracture, and both styloid processes — of the radius and the ulna — remain attached to the shaft of the bones. Anterior luxation may occur from injury, but more commonly it is seen in the form of a subluxation which occurs slowly and spontaneously usually between the ages of 1 6 and 25 years. It was first described by Dupuytren and later by Madelung. The ulna projects markedly toward the dorsal surface while the radius is somewhat less prominent; there is a marked hollow on the palmar surface of the forearm just above the hand. Fig. 357, from a girl 18 years of age, shows these points clearly. The ulna may be dislocated forwards or backwards. When associated with fracture of the radius it is not so rare, but otherwise it is seldom seen. Posterior luxation is the most common. The internal lateral ligament and triangular cartilage both usually remain attached to the lower end of the ulna, which projects markedly on the dorsal surface. The injury has been produced by falls on the hand and forced pronation. In recent cases reduction can usually be accomplished by direct pressure and rotation of the hand, with traction. The secret of success in the diagnosis of these obscure fractures and luxations in the region of the wrist lies in knowing the surface anatomy and in being able to recognize the various deeper structures by the sense of touch. Formal excisions of the wrist are undertaken for tuberculous disease. It is desirable that all the affected tissues be removed. To do this is difficult, on account of the number and extent of the various carpal bones and joints as well as the danger of injuring the important arteries, nerves, and tendons by which they are surrounded. To remove the diseased parts without inflicting avoidable injury requires an exact and skih'ul operator who has a precise knowledge of the anatomy of the region. Interference with the sheaths of the tendons will result in stiffness and loss of control and power in the hand. Maisonneuve, Boeckel, and Langenbeck operated through a single dorsal incision along the radial side of the extensor indicis tendon. As this incision was found to give insufficient room, Lister, in 1865, advised an additional incision along the ulnar border. Oilier, of Lyons, modihed Lister's radial incision by carrying it radial incision and the dotted line the palmar ulnar incision. nearer the extensor indicis tendon to better avoid injuring the radial artery and the insertion of the extensor carpi radialis brevior tendon. Oilier also carried his incision somewhat higher on the wrist and raised the tissues with a periosteal elevator, and divided no tendons. Ollier's Operation. — Radial Incision. — From a point on the dorsum of the wrist midway between the styloid processes, downward and outward alongside of the extensor indicis tendon to the junction of the middle and lower thirds of the metacarpal bone of the index finger (Fig. 358). When making the radial incision, branches of the radial nerve may be seen in the lower part of the incision and should if possible be avoided. In making the ulnar incision a cutaneous branch of the ulnar nerve should be avoided as it verges toward the dorsal surface below the styloid process. The extensor indicis tendon is pulled aside and the extensor carpi radialis "brevior beneath detached with the periosteum from the base of the third metacarpal b)one. The incision is then extended higher up the wrist, care being taken not to injure the tendon of the extensor longus polHcis at the posterior radial tubercle. The periosteum is to be detached over the lower end of the radius, the radiocarpal joint opened, and the carpal bones removed one after another. The pisiform bone, unciform process, and trapezium are left when possible. In removing the unciform process the deep branch of the ulnar nerve should be avoided. If the trapezium is removed care must be taken not to wound the radial artery as it goes over the bone to dip between the first and second metacarpal bones, and also to avoid the flexor ■carpi radialis tendon as it crosses to the inner side of the ridge of the trapezium on its palmar surface. The articular ends of the ulna and radius may be removed with a small saw if necessary. As Jacobson says, this operation is a tedious and difficult one, and we might add that it is liable to be an inefficient one, owing to the inability to remove all of the diseased tissue. Operations of Studsgaard and Mynter. — Studsgaard of Copenhagen in 1891 (" Hospitalstidenden," Jan. 7, 1891) suggested, and Herman Mynter of Buflalo ( Transactions of the American Orthopedic Association, 1894, vol. vii, p. 253) carried out the method of splitting the hand on the dorsum from the web between the second and third fingers to the lower edge of the radius, and on the palmar ■surface to the base of the thenar eminence. Dr. Wm. J. Taylor {Annals of Surgery, vol. xxii, 1900, p. 360) modified the operation by employing only the dorsal incision. This operation gives full access and exposure to the parts, and all disease can most readily be recognized and removed with the scissors or other instruments. It is probably the best method of •exposure and operation when simple incision and curetting does not suffice. When it is possible to do so the interarticular fibrocartilage over the lower end of the ulna is not to be interfered with. The lower radio-ulnar joint is therefore not injured and the movements of pronation and supination are preserved. long palmar flap is preferred. Incision. — On account of retraction, the knife is entered i cm. (\| in.) below the radial styloid process — the thumb being abducted to render the tissues tense, and, if the left hand is being operated on, the knife is carried straight down well on the thenar prominence. It is then curved abruptly across the palm on a level almost or quite as low as the web of the thumb. It is continued to the ulnar side and up to within i cm. of the styloid process of the ulna. The flap should be an almost square one with rounded ends. The incision goes down to but does not divide the flexor tendons (Fig. 359.) This flap, embracing the palmar fascia and part of the thenar and hypothenar muscles, is at once raised from the flexor tendons, care being taken not to catch the knife on the unciform and pisiform bones. The flaps being reflected and the hand flexed, disarticulation is begun by entering the knife on the uhiar side of the dorsum, beneath the styloid process. The joint is followed around to the radial side, bearing in mind that it curves markedly upwards. If the right hand is being operated on and the knife is entered transversely it will strike the scaphoid bone, therefore it must be at once inclined obliquely upward. Section of the flexor muscles and anterior ligament completes the disarticulation. The radial artery will be cut in the snuff-box. The ulnar will be seen on the inner side of the palmar flap, and on the outer side may be seen the superficial volar. Some small branches of the anterior and posterior carpal and interosseous arteries may require ligation. Some operators remove the styloid processes of the radius and ulna. If this is done, care is to be taken not to go so high as to injure the insertion of the brachioradiaUs on the radius and the attachment of the triangular cartilage on the ulna. Usually the styloid processes are not interfered with, in order to avoid impairing the movements of pronation and supination. hand to dip between the first and second metacarpal bones and the two heads of the abductor indicis muscle. The course of the artery is indicated by a line drawn from the tip of the styloid process of the radius to the upper end of the first interosseous space (see Fig. 348, p. 338). The incision is usually made in the direction of the tendons from the styloid process down. As soon as the skin is divided there may be exposed in the superficial fascia some branches of the radial nerve and the radial vein. These being pushed aside, the deep fascia is opened and the artery found with its two companion veins lying deep down on the external lateral ligament and trapezium. The most common error in this operation is mistaking the superficial vein for the artery and not searching deep enough. If the radial artery is wounded as it passes through the snuff-box bleeding will be very free. It is almost impossible to ligate the divided ends in the wound because the proximal end retracts under the short extensor tendons of the thumb and the distal end retracts through the first interosseous space deep into the palm of the hand so that they cannot be reached. When such is the case it is necessary either to ligate the ulnar and radial arteries on the anterior surface just above the wrist or, as we did in one case, pack the wound with antiseptic gauze and keep the hand well elevated. As has already been stated, the hand is the essential part of the upper extremity, and mobility is its main characteristic. It terminates in five digits which possess a bony support or framework. In order that the fingers may perform their many complicated movements numerous joints are inserted which necessitate a still greater number of bones. The movements of the hand and fingers are accomplished not only by the long flexors and extensors of the fingers and the flexors and extensors of the carpus, which, as has already been shown, come down from the forearm, but in addition by numerous short muscles situated in the hand itself. An especial peculiarity of the human hand is the ability to oppose the thumb to the other digits. convex above and the lower row is convex below. The upper row, beginning on the radial side, is composed of the navicular (^scaphoid) , lunate, cuneiform, and pisiform. The three first-named articulate with the radius and triangular cartilage, forming the radiocarpal joint, but the pisiform is separate. It is perched on the cuneiform bone and is practically a sesamoid bone developed in the tendon of the flexor carpi uhiaris muscle. The anterior end of the navicular (scaphoid) has on its palmar surface a tuberosity which can be felt immediately below the flexor carpi radialis tendon at the wrist ; this tendon passes along the palmar surface to insert in the base of the second metacarpal bone (Fig. 360). The lower row, beginning on the radial side, is composed of the trapeziiim, trapezoid, os magjiitm, and unciform. The first three articulate with the first three metacapal bones but the unciform, like the cuboid in the foot, articulates with twometacarpal bones — the fourth and fifth. The unciform bone has a hook-like (unciform) process on its palmar surface. It can be felt by deep pressure 2 cm. (about ^ in.) below and to the radial side of the pisiform bone. This process and the pisiform bone give attachment to the ulnar side of the anterior annular ligament. The Metacarpal Bones. — The metacarpal bones have their bases at the carpus and their heads toward the phalanges. The shafts are small as compared with the extremities, and hence are not infrequently fractured. On each side of the head is a small projecting tubercle, which, when the bone becomes luxated, catches in the tissues and hinders reduction. On the palmar surface of the base of the second metacarpal bone is inserted the flexor carpi radialis and into the base of the fifth the plexor carpi nlnaris, which is continued onward from the pisiform bone. On the dorsal surface, into the base of the second, is inserted the extensor carpi radialis loiigior ; into the base of the third (and part of the second) is inserted the extensor cmpi radialis brevior, and into the base of the fifth, the extensor carpi iclnaris (Fig. 361). extensor of the latter, the carpus remaining immovable. The Phalanges. — -The thumb has two phalanges and the fingers each three. These are called the proximal, viiddle, and distal phalanges, also the Jirst, second, and third phalanges. The thumb has only 2. proximal and a distal phalafix. Into the middle phalanges on their palmar surfaces are inserted the flexor sublimis digitorum tendons and into the distal the flexor profu7idus (Fig. 362). There is only one long flexor to the thumb and it is inserted into the distal phalanx. (Fig. 363). On the dorsum of the proximal phalanx the tendon splits into three parts. The middle slip inserts into the bases of the middle phalanges, while the two lateral slips, after receiving the insertions of the lumbricales and part of the insertions of the interossei, insert into the bases of the distal phalanges of the fingers (Fig. 364). The thumb has two separate extensors, the extensor brevis pollicis and the extensor longzcs pollicis. Into the bases of the proximal phalanges are inserted the remaining portion of the tendons of the interossei muscles, which move the fingers toward and from one another, and slips from the palmar fascia. The main function of the interossei and lumbrical muscles is to extend the distal and middle phalanges and to flex the proximal ones. When, therefore, most of them are paralyzed, as occurs when the ulnar nerve is divided, the distal and middle phalanges are flexed and the proximal phalanges extended, forming the claw-hand (main griffe) of Duchenne. nected by interosseous ligaments. The three bones of the first row are joined by two ligaments near their proximal surfaces which prevent any communication of the radiocarpal with the midcarpal articulations. The four bones of the second row are joined together by interosseous ligaments (fibrocartilages, Morris) which are not complete. That between the os magnum and the unciform is attached more toward the palmar surface, while that between the os magnum and trapezoid is more toward the dorsal surface. The interosseous ligament between the trapezium and trapezoid is usually lacking (Fig. 365). Synovial Membrane. — From the above description it will be seen that the joints of the carpus (with the exception of the pisiform) all communicate with one another and with the carpometacarpal joints, and that the synovial membrane is practically continuous ; hence suppuration implicating the synovial membrane at any glenoid ligament, but no posterior ligament. Movements. — While the amount of motion between the individual carpal bones is limited to a slight gliding on one another, still, when taken together, a very considerable range of movement is allowed. The hand can be flexed and extended, abducted and adducted, and circumducted, but not rotated. If the bones of the forearm at the wrist are held immovable it is impossible to rotate the hand. The radiocarpal joint bends more freely posteriorly (extension) than anteriorly, while the midcarpal iDends more freely in the opposite direction (Fig. 343, 344, p. 334), adduction (toward the ulnar side) is more extensive than abduction. The movement between the two rows of carpal bones is quite extensi\'e. The movements of the inner four carpometacarpal joints are both of flexion and extension, mainly toward the palmar surface, and a lateral flexion and extension which enables a person to "hollow" the hand and so grasp round objects. The palmar flexion of the fourth and fifth metacarpal bones is more marked than that of the index and middle ones. The middle metacarpal bone is the least movable. The metacarpal bone of the thumb articulates with the trapezium by a saddle-shaped joint which allows flexion, extension, abduction, adduction, and circumduction, but little or no rotation. Abduction, adduction, and circumduction of the thumb occur at the carpometacarpal articulation and not at the metacarpophalangeal articulation. This latter is a pure hinge-joint and possesses the movements of flexion and extension only. The metacarpophalangeal articulations of the fingers are practically saddle-shaped joints resembling somewhat the ball-andsocket joints with all their movements except that of rotation. They can be flexed to an angle of 90 degrees. The interphalangeal joints are hinge-joints and capable only of flexion and extension. The second joint can be flexed to an angle of 150 degrees and the end joint to about a right angle. Fig. 366. — Showing how. when the fingers are flexed, the prominence of the knuckles is formed by the projection of the proximal bone. The hand contains not only the tendons of the long muscles which descend into it from the forearm, but also some short muscles. They may be divided into three sets, viz : a middle set, embracing the interossei and htmbricales ; an external set, embracing the thumb muscles and forming the thenar eminence ; and an internal set, embracing the little finger muscles and forming the hypothenar eminence. The Middle Set. — The interossei muscles arise from the adjacent sides of the metacarpal bones; the lumbricales arise from the tendons of the flexor profundus digitorum. They all insert into the fibrous expansion of the long extensor tendons at the sides of the proximal phalanges (Fig. 367). When they contract they flex the proximal phalanx and extend the middle and distal phalanges. The interossei have a second insertion into the sides of the base of the proximal phalanx. By their action the fingers may be separated one from the other, or approximated. When the fingers are straight the palmar interossei act as adductors, while the dorsal interossei act as abductors. . The External Set. — The thenar or thumb eminence has four muscles, the abductor pollicis, opponcns, flexor brevis, and adductor. This latter is usually divided into two parts called the adductor transversus and adductor obliquus (Fig. 368). The flexor brevis has two heads, an outer and an inner. The outer head is inserted into the base of the proximal phalanx on its outer side along with the abductor. The inner head, called by some the first volar interosseous, is inserted into the inner side along with the adductor; between the two heads runs the tendon of the long flexor of the thumb. The opponens inserts into the outer anterior border of the shaft of the first metacarpal bone. muscle, the palmaris brevis, which is superficial to the palmar fascia and, passing transversely across the hypothenar eminence, inserts into the skin. It makes a dimple on the ulnar side when the hand is hollowed. The abductor and flexor brevis minimi digiti muscles insert on the ulnar side of the proximal phalanx, hence when they contract they tend to hollow the hand, as does also the opponens minimi digiti, which inserts on the ulnar side of the fifth metacarpal bone. The hand is twice as long as it is broad. The length of the middle finger from the metacarpophalangeal joint to its extremity is equal to the distance from the metacarpophalangeal joint to the radiocarpal joint. If the hand is turned with the palm up, the thumb diverges from the median line at an angle of 40 degrees. The palm IS hollow, with a muscular mass on each side. That on the thumb side is called the thenar eminence ; it is formed by the abductor, opponens, and outer head of the flexor brevis pollicis. The prominence on the ulnar side of the hand is called the hypothenar eminence and is formed by the abductor, opponens, and flexor brevis minimi digiti The palmans brevis muscle overlies them transversely The nalm is marked by four creases Xxxo longitudinal and two transverse. One loneitudinal crease begins at the midd e of the wrist between the thenar and hypothenar eminences to end on the radial side of the mdex finger, opposite the head of its metacarpal bone It is caused by adduction of the thumb. The other longitudinal crease runs somewhat parallel to the first, starting near the wrist and endfng in the web between the index and middle fingers. It is formed by hollowing the hand The upper transverse crease begins on the radial side of the index finfer where the first hyStar eX:r^%T^ r' 2'^^^^>^ ^^^^- ^^^ P-^- to^he middl 'of the ind^ex and Xre ?r- ' ^' ^r'"''^ ^^ '^^ ^^^^^°^ °^ '^' ^^g^^^' ^^P^^iallv the mark: ?he low/.t f 'f u ^'^^ ^?^'^ '^'°"^^ '^^ "^^^dle of the middle finger opposite to thr^''^"/ ?if ^"'f "'f^ ''f''' ^^^^^^^^^ ^y ^ ^^"^ drawn across the palm Es on the Lnn^T. ' ' '^"""^ '"^ ^"^."^" ^"-^^- The lower transverse crease ann formed b^^lT "'^'^?^^ ^PP^^^^e the head of the fifth metacarpal bone tudinal crease which passes to the web between the index and middle fingers. Midway between the crease and the webs of the fingers lie the joints of the middle, ring, and little finger. More stress is apt to be laid on a knowledge of these creases than they deserve (Fig. 369). The position of the metacarpophalangeal joints is best determined by feeling for them on the dorsum of the hand and then taking a corresponding point on the palmar surface. They are sufiiciently accurately located by taking a point 2 cm. (3/^ in.) behind the web of the fingers. The creases for the middle phalangeal joints are directly opposite the articulations. The creases for the end phalangeal joints are to the proximal side of the articulations. The deep palmar arch lies about 1.5 cm. (f in. ) closer to the wrist than the superficial. The digital arteries from the superficial palmar arch pass downward with the digital nerves, superficially, in the spaces between the metacarpal bones, to the webs of the fingers. About i cm. (\| in.) behind the web they sometimes receive branches from the deep palmar arch, and then divide to go to each lateral palmar side of the fingers. The palmar fascia di\-ides into its four slips just below the line of the superficial palmar arch, opposite the web of the thumb. On the dorsum of the hand the extensor tendons can be seen. Accessory slips usually connect the tendon of the ring finger with that of the little finger and middle finger. A slip also usually passes from the tendon of the middle to that of the index finger. The slip from the tendon of the ring to that of the little finger has been thought to restrict the freedom of the movement of the ring finger, hence in musicians it sometimes has been divided. The operation is done by firet flexing the fingers, which brings the slip well forward near the knuckle, and then introducing a thin knife longitudinally beneath it and cutting toward the skin. The procedure has not found favor among musicians. The metacarpal bones are subcutaneous and can readily be felt their entire length. The muscular prominence on the dorsum of the hand seen when the thumb and forefinger are approximated is due to the abductor indicis muscle. At its upper extremity the radial artery passes between its two heads to enter the palm. When the thumb is extended the snuff-box becomes evident and the extensor longus poUicis tendon is distinctly seen leading to the ulnar side of the posterior radial ( thecal ) tubercle on the middle of the dorsum of the radius. The tendons on the radial side of the snuff-box are the extensor brevis and extensor ossis metacarpi pollicis. When the fingers are flexed, the prominence of the knuckles is formed by the proximal bones; the distal phalanges fold under the proximal ones and the joint line is about I cm. (f in. ) below the dorsal surface of the metacarpal bones (Fig. 366, page 353). THE PALMAR FASCIA. The palmar fascia is the continuation downward of the palmaris longus tendon. It consists of a thick triangular middle portion and two thin lateral portions which cover the thenar and hypothenar eminences. The triangular iniddle portion can be divided into two layers. Its under layer is composed of transverse fibres, and blends with the anterior annular ligament ; its upper layer is composed of longitudinal fibres, the continuation of the palmaris longus, and when it reaches the middle of the palm it divides into four slips which blend with the sheaths of the flexor tendons and lateral ligaments of the metacarpophalangeal joints to insert into the sides of the base of the proximal phalanges, and aid in flexing them. The digital arteries and nerves lie between these slips on their way to the webs of the fingers. The superficial surface is intimately adherent to the skin abo\'e, especially at the webs of the fingers, where its fibres form the superficial transverse ligament. The intimate attachment between the skin above and fascia beneath binds these two structures so closely and firmly together that pus cannot travel for any distance between them. It either burrows deeper, or perforates the skin, or collects beneath the epiderm, forming a bleb. A strong band from the palmar fascia frequently goes to the thumb also, and when the palmaris longus contracts it tends to bring the thumb forward. The lateral portions covering the thenar and hypothenar eminences are thin and are prolonged beneath the long flexor tendons to become attached to the third and fifth metacarpal bones (Fig. 370). The hand receives its blood supply mainly from the radial and ulnar arteries, the amount which it receives from the anterior and posterior interosseous being comparatively insignificant. The continuation of the ulnar in the hand forms the superficial palmar arch and the continuation of the radial forms the deep palmar arch (Fig. 371). inner or ulnar side. As it enters the hand it lies just to the radial side of the pisiform bone with the nerve interv^ening. Both the artery and nerve lie on the anterior annular ligament. As soon as they pass the pisiform, bone they go under the small palmaris brevis muscle and the palmar fascia, and lie on the flexor tendons. The artery then describes a curve across the palm of the hand toward the web of the thumb. It crosses the middle of the third metacarpal bone at or a little above the level of the web of the thumb and continues on to the radial side of the metacarpal bone of the index finger. Here it receives the superficial volar artery from the radial as well as a communicating branch from the princeps pollicis and radialis indicis. When one of these branches is large the other two are smaller or lacking altogether. Not infrequently the communication with the radial at this point is in the form of a large branch which passes superficially across the web of the thumb and index finger, and its pulsations can be both seen and felt (Fig. 372;. Branches. — As soon as the ulnar arterv' passes the pisiform bone it gives off its deep branch which passes down between the abductor and flexor brevis minimi digiti to join the termination of the radial and form the deep palmar arch. From the convexity of the superficial arch four palmar digital arteries are given off. One goes to the ulnar side of the littie finger while the other three go down between the metacarpal bones to the webs of the fingers. Here they may recei\-e a small communicating branch derived from the deep palmar arch, and about I cm. Tf in. ) back from the web divideinto collateral digital branches which run along the palmar sides of the fingers. The digital nerves as they accompany the digital arteries are superficial to them. The Radial Artery and Deep Palmar Arch. — The radial artery reaches the wrist between the brachioradialis and flexor carpi radialis tendons. It then turns sharply toward the dorsum around the extremity of the styloid process of the radius. It crosses the external lateral ligaments and the scaphoid and trapezium bones to enter the palm between the bases of the metacarpal bones of the thumb and index finger. It then passes across the palm to the fifth metacarpal bone, where it receives Branches. — The radial artery at the wrist gives off a posterior carpal branch which anastomoses with the posterior carpal branch of the ulnar to form a posterior carpal arch. From this arch descend three posterior interosseous arteries. The dorsal interosseous artery lying to the radial side of the index finger is called the dorsalis indicts. It comes ofi" separately from the radial, and may be a branch from the radialis indicis. As the radial artery enters the palm it gives off a large branch to the thumb called the princeps poUicis, and one to the palmar side of the index called the radialis indicis. Farther on, three palmar interosseous branches are given of! which communicate at the webs of the fingers with the palmar digital arteries from the superficial arch. The deep palmar arch also sends a few recurrent branches up on the anterior surface of the carpus and three perforating branches between the metacarpal bones to the back of the hand. The hand is supplied by the median, ulnar, and radial (musculospiral) nerves. They are of clinical importance on account of the paralysis of the muscles or disturbance of sensation which accompany their injury (Fig. 374). encountered. Dislocations of the Bases of the Metacarpal Bones. — Dislocations sometimes occur toward the dorsal surface. The bases of the second and third metacarpal bones in the uninjured hand form a bony prominence on the dorsum of the The bases of the metacarpal bones and carpometacarpal joints are best recognized bv following up the interosseous spaces by making firm pressure with the fino-ers between the bones ; when the upper limit of the space is reached the joints can be located 1.25 cm. ('i in.) above. Dislocations of the Phalanges on the Metacarpal Bones. — These dislocations occur with moderate frequency. Dislocation of the thumb occurs most frequently and is well known. The little finger is next in frequency, while the other three are rarely luxated. When luxation of the proximal phalanx of the little finger occurs it acts precisely as does that of the thumb (as I have seen in one case, Fig. 375). As the thumb dislocation is the most troublesome it alone will be described. Dislocation of the Proximal Phalanx of the Thumb. — This displacement occurs when the thumb is hyperextended on its metacarpal bone fFigs. 376 and 377), and it is often impossible to reduce it without di\ision of the resisting structures. ^ The head of the metacarpal bone is much larger than the shaft immediately behind it and projects especially on its palmar surface toward each side, forming two tubercles. The ioint has two lateral ligaments and an anterior or glenoid ligament. These are more firmly attached to the phalanx than to the metacarpal bone, so that in dislocation they are torn from the latter. Insertino- into the outer side of the base of the proximal phalanx are the tendons of the abductor and outer head of the flexor brevis poUicis. They blend with the lateral ligament and ha\'e de\'eloped in them a sesamoid bone which rides on the tubercle. Inserting into the inner side of the base of the proximal phalanx are the inner head of the flexor brevis and the adductor obliquus and transversus pollicis muscles. They blend with the lateral ligament and contain a sesamoid bone which rides on the and sesamoid bones. When the thumb is hyperextended the glenoid and lateral ligaments are torn loose from the metacarpal bone and carry with them the tendons and sesamoid bones already described. The head of the metacarpal bone projects forward in the palm and can be felt beneath the skin ; the flexor longus pollicis tendon slips to the inner side of the bone. As the head pierces the capsule the latter, strengthened by the tendons of the short muscles of "he thum-b, contracts behind it like a collar and prevents reduction. Reduction is to be attempted by extending the phalanx until it is at right angles with the metacarpal bone and dragging its base forward over the head of the metacarpal bone and then flexing. wound or subcutaneously, the lateral ligament and tendons on one side (the radial) are loosened from the base of the phalanx, which can then be brought forward. This, of course, divides the tendinous collar which prevents reposition (Fig. 377). Dislocations of the Middle and Distal Phalanges. — These frequently occur in playing ball games. In attempting to catch the ball the tip of the finger may be struck and the phalanx hyperextended and thereby luxated (Fig. 378). These luxations are usually readily reduced by simple traction and flexion. Sometimes, however, reduction is not complete, or there is a concomitant fracture, hence the crippled and deformed fingers so often seen in the case of base-ball players. Fractures of the carpal bones are often only suspected or detected by means of a skiagraph. They are quite rare and are ahnost impossible to distinguish clinicallv from ordinary sprains. Fractures of the metacarpal bones are more common. The bones are subcutaneous on the dorsum of the hand and can be readily felt throughout their entire length. They are not infrequently broken by a blow on the end of the bone in fighting. Hamilton states that in every case in which the fracture has been produced by a blow on the knuckles the distal end of the distal fragment has been drawn toward the palm and its proximal end projected toward the dorsum. This is accounted for by the greater strength of the flexor muscles. The first, third, and fourth metacarpophalangeal joints have one extensor tendon, the extensor communis digitorum. The second and fifth have in addition the extensor indicis and the extensor minimi digiti. There are two powerful flexors, the sublimis and profundus, and these are aided by the palmaris longus, interossei, and lumbricales muscles. In one case Hamilton saw a dorsal projection of the proximal fragment which he believed to be due to the action of the extensor carpi radialis muscle because the deformity became less marked when the hand was bent backward and the tendon relaxed. On anatomical grounds one would expect this dorsal displacement to occur in fractures of the third metacarpal bone. It has only one carpal tendon inserting into it, the extensor carpi radialis brevior. The second has the flexor carpi radialis inserting on its palmar surface and the extensor carpi radialis longior on its dorsal surface. The fifth metacarpal bone has the flexor carpi ulnaris on its palmar surface and the extensor carpi ulnaris on its dorsal surface. Hence it would be expected that the flexor and extensor muscles would neutralize each other. In order to relax the parts as well as to allow for the concavity of the palmar surface of the metacarpal bones a rounded pad is to be placed in the palm and the hand placed on a splint ; sometimes an additional flat pad and small dorsal splint is of service. Care should be taken not to displace the fragments laterally by constricting the hand with the bandage. Fractures of the Phalanges. — These are frequently compound, necessitating amputation. Fracture of the proximal phalanx necessitates a splint extending into the hand, but for the middle and distal phalanges a short splint is suliftcient. The action of the interossei and lumbricales through their insertion into the extensor tendon is liable to draw the distal fragment toward the dorsum if the fracture is left untreated. Wounds of the hand, owing to the free blood supply, heal rapidly. An exception, however, is to be made in the case of the tendons. These frequently slough. If the tendons are divided they are to be immediately united with sutures, otherwise they retract into their sheaths. If nerves are divided where they are large, as near the wrist, they should be sutured, because they are partly motor and supply the short muscles of the hand ; but if the digital nerves are divided they need not be sutured as they are only sensory. The median nerve enters the palm to the radial side of the median line, and its position can be determined by following down the interval between the tendons of the palmaris longus and flexor carpi radiaHs muscles. The ulnar nerve lies immediately to the radial side of the pisiform bone. Bleeding from wounds of the hand is not infrequently troublesome. The deep arch may be injured in a wound about 2. 5 cm. f i in. ) below the lower crease on the anterior surface of the wrist. Its position can also be approximately determined by THE HAND. 365 feeling for the upper end of the first interosseous space on the dorsum of the hand and selecting- a spot at a corresponding level on the palmar surface. It lies deep beneath the palmar fascia and flexor tendons and nerves, and necessitates too great a disturbance of the parts to expose it for ligation ; hence, when wounded, bleeding from it is checked by packing the wound with antiseptic gauze. A curved line, convex downward, from the radial side of the pisiform bone to the web of the thumb, describes approximately the course of the superficial palmar arch. It lies immediately beneath the palmar fascia, and if it bleeds freely can be exposed by an incision and tied. The incision should preferably be a longitudinal one to avoid wounding the digital arteries and nerves. The superficial palmar arch lies superficial to the tendons and they should not be disturbed. The digital nerves come down beneath the palmar arch, so that they need not be wounded in ligating it. As they reach the webs of the fingers the nerves become superficial to the arteries, and in the fingers they lie anterior and nearer the median line. The fingers are usually supplied with blood from the superficial palmar arch, and the digital arteries between the palmar arch and webs of the fingers may be quite large. Sometimes the fingers are supplied by large digital branches from the deep palmar arch, then those from the superficial will be correspondingly small. Purulent collections in the palm of the hand are located either beneath the palmar fascia or are connected with the sheaths of the flexor tendons. When the fingers are affected the pus may be either in the sheaths of the tendons or in the cellular tissue beneath the skin. Abscess Beneath the Palmar Fascia. — As a result of infected wounds pus may accumulate beneath the palmar fascia. The construction of this fascia (see page 357) limits the spread of the pus in some directions and favors it in others. Pus originating beneath the thick middle triangular portion will tend to point to either side, and it may show on the inner side at the hypothenar eminence, or work toward the outer side and point in the web of the thumb (Fig. 379). carpal bones and shows on the back of the hand. Sometimes the pus works directly toward the surface through small gaps in the fascia. In such cases a small amount of pus may accumulate above the palmar fascia and between it and the skin ; so that there is a collection of pus both above and below the fascia, communicating through a hole in the fascia. This is called an hour glass abscess, or the abces en bissac of the French. more serious one. In incising palmar abscesses the only safe way is to limit the incision to the skin and open the deep parts by inserting a closed pair of forceps and then separating its blades. Incisions should not be made nearer to the wrist than on a le\'el with the web of the thumb, or the superficial palmar arch may be cut. The spaces between the metacarpal bones are occupied by the digital arteries and nerves ; hence any longitudinal incisions should be made over the tendinous sheaths and metacarpal bones. Usually it is not necessary to carry the incision so deep as to open the sheaths. Incisions over the second, third, and fourth metacarpal bones are tolerably certain to avoid the digital arteries, but an incision over the fifth is liable to wound the artery going to the ulnar side of the little finger as it crosses over from the superficial palmar arch. These arteries of the palm are also liable to be more or less irregular in their location, hence it is better to avoid using the knife in the deeper structures. Suppuration in the Sheaths of the Tendons. — If the sheath of the tendons of the hand or lingers become infected, either by being penetrated by a foreign body or by extension from the surrounding tissues, the pus tra\els along the tendon as far as the sheath extends. The sheaths of the tendons vary in their extent. The fiexor profundus and subhmis tendons he together in single sheaths, which commence at the base of the distal phalanx. That of the thumb follows the long flexor tendon up the thumb, beneath the annular ligament, to 3 or 4 cm. (i}4 in.) above the wrist; that of the little finger passes up to almost opposite the level of the web of the thumb and then spreads over toward the radial side and envelops the remaining tendons of the other three fingers, forming the great carpal bursa which extends up under the annular ligament to 3 or 4 cm. above the wrist (Fig. 3S0). tend to find an exit. a space of about 2 cm. ( 2^ in. ) intervening between the proximal ending of the tendon sheaths of the middle three fingers and the great carpal bursa. This is the usual arrangement, but not infrequently the sheath for the little finger ends, as do the other three, opposite the head of the metacarpal bone, or it may go up the entire way to the wrist as a separate sheath, in which case the great carpal bursa en\'elops only the tendons of the index, middle, and ring fingers. When suppuration occurs in the sheath of the thumb or little finger it is much more serious than in the other three, because the pus tends to travel directly upward and involve the palm, and go even above the wrist. When suppuration involves the index, middle, or ring fingers it stops when it reaches the vicinity of the metacarpophalangeal joints and involves the palm and carpal bursa only by breaking through its own sheath and breaking into the carpal sheath. This it is not likely to do unless the infection is virulent and the suppuration abundant. Suppuration Involving the Fingers. — When suppuration occurs in the middle or proximal phalanx the pus may occupy the tissue between the skin and tendon and not involve its sheath, hence is not liable to extend rapidly. When the end phalanx is affected the affection is known as panaris, zuhitloiu, felon, etc. The pulp of the finger resembles that of the heel, the scalp, the palm of the hand, etc., in the fact that the under surface of the skin sends off firm fibrous bands or fibrils which are attached to the parts beneath. The spaces between these fibrils are filled in with fatty tissue and vessels, nerves and lymphatics (Fig. 381 )._ Infection begins in the skin through some small wound, as the tearing of the nail, pin-punctures, etc., and involves the fatty tissue beneath. If exit is not given to the pus it is often unable the distal phalanx. to break through the hard skin on the surface. Since the fibrous bands prevent swelling to any extent, it burrows deeper and involves the periosteum along which it proceeds to the region of the joint, here it may enter the sheath of the tendon when it rapidly proceeds upward as far as the sheath extends. The hand and fingers are abundantly supplied with lymphatics which begin in a plexus around the matrix of the nail and the pulp of the fingers and unite to form lymphatic trunks which proceed up the wrist and forearm. There are both superficial and deep sets, which communicate at the wrist. sometimes possesses a few nodes in the forearm and one at the flexure of the elbow. The superficial set, both anteriorly and posteriorly, concentrates in the supratrochlear nodes and thence proceeds to the axilla. Some of the lymphatic vessels pass by the supratrochlear nodes and empty direct into the axillary nodes (Fig. 382). In infections of the fingers or hand the infection follows the lymphatic trunks, which can be seen as red lines running up the forearm. Suppuration may involve the supratrochlear and, later, the axillary nodes. As some of the lymphatic trunks pass by the supratrochlear nodes to empty direct into the axillary nodes there may be infection of the latter without any implication of the former. Enlargement and inflammation of the occasionally present deep lymphatic nodes of the forearm is clinically unknown, so it may be said that practically there are no lymphatic nodes below the supratrochlear ones. In these amputations it is particularly necessary to be able to accurately locate the joints. The distal phalanx when flexed always passes under the proximal one. When the flexor and extensor tendons are cut they should be sewed either to their sheaths or united to one another over the ends of the bone. Distal Phalanx. — In removing the distal phalanx the joint is opened by an incision across the dorsum in a line with the middle of the side of the proximal phalanx. A long flap is to be cut from the palmar surface. As the flexor and extensor tendons are inserted into the base of the distal phalanx, it will be an advantage to retain it if possible. The digital arteries may even here require ligation. Metacarpophalangeal Amputation. — Lateral flaps are usually used. They are often made too short because the joint is thought to be higher than it really is. By flexing the thumb to a right angle the joint can be felt on the dorsum about 8 mm. (ys in. ) below the top of the knuckle. The flaps must be cut as far forward as the middle of the phalanx. The two digital arteries on the palmar surface will require torsion or ligation. If the base of the phalanx can be retained the attachments of the short muscles of the thumb are preserved and additional control is o-iven to the stump. Carpometacarpal Amputation. — The upper limit of the metacarpal bone may often be difficult to recognize. The best way to locate it is to feel for the snuffbox and then feel for the joint a centimetre (say a half inch) in front of it. The ^Extensor communis digitorum is easier to amputate through the joints, it is better to cut through the bone and save part of the phalanx, because much better control over the. movements is obtained on account of the insertion of the tendons into the base and sides of the phalanges. Into the base of the distal phalanx is inserted the common extensor and flexor profundus digitorum. Into the base of the middle phalanx on its dorsal surface is inserted the extensor communis digitorum, which is reinforced by the lumbricales and interossei ; on its palmar surface is inserted the flexor sublimis digitorum. Into the bases of the proximal joint of the index finger and between the proximal and middle phalanges of the middle finger. phalanges are inserted the interossei muscles. The lines of the joints are to be recognized by remembering that the distal phalanx always flexes beneath the proximal one, therefore the prominence is always formed by the head of the proximal bone. The joint is to be opened by an incision across its anterior surface when flexed, and not on its dorsal surface. Anterior or palmar flaps are always used, except at the metacarpal joints. The digital arteries lie on the lateral palmar surface on each side of the flexor tendons and may require torsion or ligation. The fingerjoints have lateral ligaments and a palmar or glenoid ligament. On the dorsal surface there is no ligament, its place being filled by the extensor tendon (Fig. 383). Metacarpophalangeal Amputations. — Lateral flaps are used in disarticulating at the metacarpal joints. In a well-developed hand the line of the joint will be 1.25 cm. {}4 in.) below the dorsal surface of the metacarpal bone (Fig. 384). In consequence of not first recognizing the position of the joint the flaps are often cut too short. The incision must not involve the webs of the fingers but should reach as far forward as the middle of the phalanx. If this is not done it will necessitate resection of the head of the metacarpal bone, which will materially weaken the hand. The two palmar digital arteries will require ligation, and the tendons should be sutured over the face of the bone or to their sheaths, closing them. THE ABDOMEN. The abdomen comprises that part of the body anterior to the spine and erector spin« and quadratus lumborum muscles, and from the diaphragm above to the rim of the pelvis below. The true pelvis is not included. The peritoneal cavity embraces the cavity of the abdomen and also that of the peh-is. An accurate knowledge of the topographical anatomy of the abdomen with its various contained organs is absolutely essential to both the physician and the surgeon for diagnostic purposes, and especially to the latter in carrying out his operative procedures. The surface of the abdomen should be studied with reference to physical diagnosis ; its ivalls, because herniae frequently protrude through them, and because they must be traversed in obtaining access to the structures within; its contents, in order to properly carry out necessary operative measures. The rounded form of the abdomen is influenced by its bony support, by the muscles and fascias attached to these bones, and by the organs within. In the upper portion of the abdomen the tip of the ensiform cartilage can be felt — it is opposite the eleventh dorsal vertebra. Immediately above the ensiform cartilage is its junction with the second piece of the sternum, which is opposite the tenth dorsal vertebra,— the sixth and seventh costal cartilages meet at this point, — the seventh, eighth, ninth, and tenth cartilages can be followed down to the lower border of the chest ; just below this, one free rib, the eleventh, can be distinguished and sometimes in thin people the twelfth; but the twelfth is often not palpable because it is buried beneath the erector spinae muscles. The most certain way of identifying any particular rib is to count from the sternal (Ludwig's) angle, opposite the second rib. Below, the crest of the ilium can be followed back to the posterior superior spine of the ilium and in front to the anterior superior spine. The spines of the pubes can be recognized, as well as the upper edge of the pubic bones. The depressions for the linea alba, lineae semilunares, and lineae transversie are all more marked above the umbilicus. The timbilicns lies on the disk between the third and fourth lumbar vertebrae, about 2. 5 cm. ( i in. ) above a line joining the highest points of the crests of the ilia. It is just below the midpoint between the symphysis and ensiform cartilage. Regions. — -For clinical purposes the abdomen has been divided into regions, so that the location of tumors, signs, etc. , can be readily indicated. The most convenient division is into nine regions by two transverse and two longitudinal lines. The vipper transverse line passes from the tip of the tenth rib — which corresponds to the lower end of the thorax — on one side to that of the other. The lower transverse line passes from the anterior superior spine of the ilium on one side to that of the opposite ; it is on a level with the second sacral vertebra. The two longitudinal lines pass directly up on each side from the middle of Poupart's ligament. They strike the cartilages of the eighth ribs, but at too indefinite a point to serve as a guide. The middle regions are the epigastric, the junbilical, and the hypogastric, or p7ibic. The lateral regions are the right and left hypochondriac, the right and left lumbar, and the right and left iliac. The abdomen is sometimes divided into four quadrants by a longitudinal median line and a transverse line through the umbilicus. .This mode of di\'ision is used more by physicians than by surgeons. , The lower transverse line is drawn by Ouain and Cunningham from the top of the crest of one ilium to that of the other, but as the umbilicus is often lower than usual this line may pass above it. Anderson (Morris's "Anatomy") suggests using the lincce semilunares instead of the usual longitudinal lines, but as yet this modification has not been generally accepted. Lima Alba. — The linea alba passes in the median line from the ensiform cartilage to the symphysis pubis. It is formed by the fusion of the sheaths of the recti muscles. A little over half way down is the umbilicus. The linea alba is broad and distinct above the umbilicus, separatino- the recti muscles a half centimetre ( \ in. ) or more ; below, it diminishes and almost or quite disappears, leaving the recti muscles almost in contact with each other. Its fibres run longitudinally, obliquely, and transversely. The transverse fibres are the strongest and not infrequently have gaps between them which allow the subperitoneal fat to protrude and form a Jiernia in the median line which can be felt under the skin as a small, firm, rounded body. When these hernias are operated on they are found to be masses of subperitoneal fat with a somewhat constricted pedicle which emero-es from a transverse slit in the linea alba. The peritoneum is not protruded. Some of the fibres of the linea alba are prolonged into the subcutaneous tissue and skin, thus binding it down and forming a groove distinctly visible above the umbilicus but disappearing below it. It does not long prcA-ent extravasated urine from passing from one side to the other (Fig. 385). The Umbilicjis. — The umbilicus lies over the disk between the third and fourth lumbar vertebrae, and 2. 5 to 4 cm. ( i to i ^ in. ) above a line joining the tops of the crests of the ilia. In the foetus it transmits the iimbilical vein, the two itmbilical arteries, and the remains of the vitelline dicct and stalk of the allantois. The umbilical vein becomes the round ligament of the liver and is the only structure passing into the upper half of the umbilicus. The umbilical arteries within the body form the obliterated hypogastric arteries, being continuous -with the superior vesicals. The vitelline duct in fetal life passes from the umbilical vesicle to the small intestine. Normally it entirely disappears. If its proximal extremity persists it forms a Meckel s diverticuluiii, a projection 3 to 7 cm. long from the small intestine i to 3 feet abo\'e the ileoc^ecal valve. It may persist up to the umbilicus and cause a fistula through which feces may discharge, or form a fibrous cord which may cause a fatal strangulation of the intestine. The stalk of the allantois ends as a fibrous cord, called the urachics, running down to the fundus of the bladder. If the urachus remains patulous urine may be discharged through the umbilicus. LinecE Semilunares. — There are two lineae semilunares, which pass from the spines of the pubes in a cur\-e upward and outward along the outer edges of the recti muscles to strike the chest at the ninth costal cartilage. Ordinarily they are 6.25 to 7.5 cm. (2^^ to 3 in. ) to the outer side of the umbilicus and midway between the anterior superior spine of the ilium and the median line. The fibrous tendon of the external oblique muscle passes on to the surface of the rectus muscle to blend with its sheath a short distance internal to its lateral border, while the internal oblique blends with the transversalis in the linea semilunaris; so that an incision through the latter would traverse two fibrous layers — one the expansion of the external oblique and the other the blended internal oblique and transversalis. The upper end of the right linea semilunaris indicates the position of the gall-bladder. The point where a line from the umbilicus to the right anterior superior iliac spine is crossed by the linea semilunaris is 2.5 cm. above the root of the appendix and just inside of McBurney's point, or the usual site of greatest tenderness in appendicitis. LinecB Transversa:. — In thin muscular people when the rectus muscle contracts grooves are seen on its surface which indicate the position of the fibrous lines called the lineae transversae. One is just above the umbilicus, a second opposite the tip of the ensiform cartilage, a third midway between these two, and sometimes a fourth below the umbilicus. The one opposite the umbilicus is the most marked. They are adherent to the sheath of the rectus anteriorly, but pass only part way through the muscle, so that the rectus muscle can be lifted off of the posterior but not off of the anterior portion of its sheath. This fact is to be remembered in operating. THE POSITION OF THE ABDOMINAL MSCERA. Liver. — Upper Border. — The highest point of the liver is on the right side just to the inner side of the nipple v»here it rises to the middle of the fourth interspace. To the left it crosses the xiphosternal articulation to follow the lower border of the heart to a little beyond its apex, but hardly to the nipple line, where it reaches the lower border of the sixth rib. Its highest point on the left side is under the fifth rib posteriorly. On the right side it reaches the upper border of the fifth rib in the mammary line, the eighth rib in the midaxillary line, and the tenth rib in the scapular line (Tyson, " Physical Diagnosis," p. 51 j. In the median line it is about opposite the tenth thoracic spine (Fig. 386). Lower Border. — From just below and to the inner side of the left nipple the lower border of the liver passes across the left eighth costal cartilage, then across the median line midway between the xiphoid articulation and the umbilicus to reach the right ninth costal cartilage, and then follows the edge of the ribs posteriorly. In the upright position, and in women, the liver may project a centimetre or two below the edge of the chest. In the aged it may be slightly retracted. Liver Dulness. — On percussion the liver dulness in the right mammary line extends from the upper border of the sixth rib to the lower edge of the chest. In the a.xillary line it reaches the upper border of the eighth and in the scapular line the upper border of the tenth rib. From these limits it extends downward to the edge of the ribs. Gall-Bladder. — The gall-bladder reaches the surface at the anterior end of the right ninth costal cartilage, just to the outer edge of the rectus muscle. This is the upper end (^f the right linea semilunaris. Stomach. The cardiac end lies under the cartilage of the seventh rib, 2.5 cm. Ci in.) from the edge of the sternum and about 10 cm. (4 in.) from the surface. When the stomach is empty the pylorus lies in the median line 2.5 to 5 cm. (i to 2 in.) below the tip of the xiphoid or ensiform cartilage; when distended the pylorus moves 3 to 5 cm. to the right. The fundus rises in the left nipple line to the lower edo-e oi the fifth rib. The lower border of the stomach crosses the median line to 7. S cm. (2 to 3 in. ) above the umbilicus. In the old it may reach as low as the umbilicus, and when dilated may go far below it. Pancreas. — The pancreas lies beneath the stomach and transverse colon, stretchino- across from the duodenum on the right of the spine to the spleen on the left. Itsbody lies over the first and second lumbar vertebrae. This would bring its SpLen!— The spleen lies under the ninth, tenth, and eleventh ribs of the left side Its long axis follows the tenth rib. Its anterior end is at the midaxillary Ime, while its posterior end reaches to within 4 cm. {1% m. ) of the median hne. Kidneys.— The lower edge of the right kidney reaches to withni an inch of the level of the umbilicus; this is about opposite the level of the third lumbar spme The left is 1.25 to 2 cm. {% to V^ in.) higher. This leaves about 4 cm (i^ m ) between the lower edge of the kidneys and the highest point of the iliac crests. Their upper edge is almost or quite up to the level of the tip of the xiphoid cartilage. The pelvis of the kidney and commencement of the ureter are 5 cm (2 in. ) from the median line, about on the level of a line joining the upper ends of the i^eae semilunares. Posteriorly the right kidney rises to the lower border of the eleventh rib the left kidney to the upper border. The outer edge of the kidney is a litde beyond the outer borders of the erector spinae and quadratus lumborum muscles. Small Intestine. — Duodenum. — The duodenum begins at the pylorus and curves first upward and then downward along the right of the spine to the body of the third lumbar vertebra; it then crosses and ascends to the left side of the body of the second. This places it just above the umbilicus in the median line and behind the transverse colon. Mesentery. — The upper extremity of the root or attachment of the mesentery begins 2.5 cm. (i in.) to the left of the median line and 7.5 cm. (3 in.) above the umbilicus. It runs obliquely downward and to the right for about 15 cm. (6 in.) to a point below and to the right of the umbilicus, over the right sacro-iliac joint, and 8 to 10 cm. (3 to 4 in. ) above the middle of a line joining the anterior superior spine and the symphysis pubis. anterior superior iliac spine on a line to the umbilicus. Appendix. — The base of the appendix is 2 cm. (^ in.) below the ileocaecal valve. This is a little (i in.) below the point where the linea semilunaris is crossed by a line drawn from the anterior iliac spine to the umbilicus, and is opposite the level of the anterior spine. to the level of the eighth costal interspace. Bladder. — When empty the bladder sinks into the pelvis. When distended it rises toward the umbilicus, carrying the peritoneal fold with it so as to leave a space of 2.5 to 5 cm. f I to 2 in. ) between it and the top of the pubis. Abdominal Vessels. — The aorta bifurcates on the body of the fourth lumbar vertebra 2 cm. ( 3,^ in. ) below and to the left of the umbilicus. A line from this point to the middle of one drawn from the anterior superior spine to the symphysis pubis indicates the course of the iliac arteries. The upper third of this line is the common iliac and the lower two-thirds the external iliac. The ureters cross the points of bifurcation of the common iliac arteries. The cceliac axis lies just below the tip of the ensiform cartilage. The renal arteries are about 5 cm. (2 in. ) lower. The iliac veins lie along the inner side of the iliac arteries, and the ascending cava runs along the right side of the aorta. The deep epigastric arteries run lengthwise at or a little outside of the middle of the recti muscles. They pass beneath the edge of the recti a little below the level of aline joining the umbilicus and middle of Poupart's ligament. versalis fascia, subperitoneal tissue, and peritoneum. Skin. — The skin of the abdomen is moderately thin and lax. It is adherent at the linea alba. In making incisions care is to be taken not to think it thicker than it is and so open the abdominal cavity and perhaps wound the intestines. This is especially liable to occur in the median line — where the subcutaneous fat is not so abundant as elsewhere — and over hernial protrusions, particularly umbilical, where the thinned and distended skin may lie in contact with the peritoneum. on this fibrous layer but are too small to cause troublesome hemorrhage; a few minutes' compression with haemostatic forceps serves to stop bleeding from them. This layer is attached at the linea alba, but not sufficiently closely to pre\-ent extra vasated urine from crossing and reaching both flanks. It is also attached to the fascia lata just below Poupart's ligament, and here it does prevent urine from passing downward on the thigh. It passes inward over the spermatic cord and is continuous with the dartos of the scrotum and its septum. It is attached to the spines of the pubes and to the symphysis in the median line. This leaves a space or abdominoscrotal opening over the pubic bone on each side of the median line through which extravasated urine rises from the perineum and scrotum to reach the surface of the abdomen. The muscles of the abdomen are arranged in two distinct groups : a longitudinal group embracing the recti and pyraniidales and a transverse group embracing the external and internal oblique and the transversalis of each side. Sheath of the Rectus.— T\\^ rectus muscle is enclosed in a fibrous sheath formed by the external and internal oblique and transversalis muscles. The anterior layer is attached to the surface of the muscle by the linear transversee already described (p. 372). The edge of the sheath on one side blends in the median line with that of the other side to form the linea alba. Above the umbilicus, an incision in the median line passes through fibrous tissues only and the muscles on each side are not may expose the edges of both. The lateral edge of the sheath is formed primarily by the splitting of the tendon of the internal oblique muscle, one part going in front and the other behind the muscle. The tendon of the external oblique blends with the anterior layer of the tendon of the internal oblique a little to the medial side of the edge of the rectus, and as the pubes is approached the external oblique has its attachment nearer and nearer to the linea alba, so that close to the pubes the external oblique is separated from the internal oblique and goes to form the internal pillar of the external ring and has the conjoined tendon behind it (Fig. 388). The tendon of the transversalis blends with the posterior layer of the internal oblique tendon until the lower fourth of the rectus is reached, when they both pass in front of the rectus to form the conjoined tendon. The medial portion of the sheath of the rectus is attached to tlie symphysis and crest of the pubis ; its lateral portion, forming the conjoined tendon, is attached from the spine of the pubis along the iliopectineal line for the distance of 4 cm. (i)4 in.). It lies behind the external abdominal ring. The lower edge of the posterior portion of the sheath of the rectus is called the semilunar fold of Douglas; the deep epigastric artery ascends beneath this fold about its middle, or a little to its outer side. From this arrangement it will be seen that an incision over or near the lateral edge of the rectus below the umbilicus will pass through two aponeurotic layers, viz. , the external oblique and the blended tendons of the internal oblique and transversalis (Fig. 388). If it is desired to examine the rectus muscle, its sheath can be opened at its edge and the muscle lifted up from the posterior layer, but it cannot be detached from the anterior layer above the umbilicus unless dissected loose from the lineae transversse. The external oblique arises from the eight lower ribs. Its posterior portion passes almost directly downward to insert into the anterior half of the crest of the ilium. It is crossed obliquely by the anterior margin of the latissimus dorsi muscle a short distance above the crest, thus leaving a triangular space between them called Petit' s triangle (trigomcm himbale) (see page 394). As the external oblique approaches the hnea semilunaris and anterior superior spine it becomes tendinous, its fibres being nearly but not quite parallel with Pouparf s ligament. Its lower edge forms Poicparf s ligament (ligamentum inguinale) and continues down on the thigh as the fascia lata. Its inner portion, above and external to the spine of the pubis, divides to form the external abdominal ring for the passage of the spermatic cord. The outer side of the opening is called the external pillar or column; it is continuous with Poupart's ligament, inserts into the spine of the pubis, and is prolonged along the iliopectineal Hue for a short distance (2 cm.) to form Gimbernat' s ligament. Sometimes it is continuous upward and inward to the median line on the sheath of the rectus, forming what has been called the triangular fascia (Colles). The inner side is called the internal pillar or column. It inserts into the crest of the pubis. The transverse fibres passing from one pillar or column to the other are called inter columnar fibres. The internal oblique (Fig. 389) arises from the lumbar aponeurosis, the anterior two-thirds of the crest of the ilium, and the outer half of Poupart's ligament. It inserts into the lower three ribs and, through the sheath of the rectus and conjoined tendon, into the linea alba, the crest and spine of the pubis, and iliopectineal line for about 4 cm. The fibres arising from the lumbar aponeurosis and the posterior portion of the iliac crest pass upward and inward. Those from the region of the anterior superior iliac spine radiate like a fan ; the lower ones, together with the fibres arising from the outer half of Poupart's ligament, arch over the cord and end in the conjoined tendon. Some fibres are continued down over the cord, forming the cremaster muscle. The cremaster muscle usually arises from Poupart's ligament, beneath the spermatic cord, from the lower edge of the internal oblique to near the spine of the pubes, thus obliterating the space usually shown to the under side of the cord, between it and Poupart's ligament. The fibres of the cremaster hang in loops on the cord, and are attached by their distal extremity to the pubic bone in the neighborhood of the spine. The transversalis muscle arises from the six lower ribs, through the lumbar fascia from the trans\'erse processes of the five lumbar vertebrae, and from the anterior two-thirds of the iliac crest and outer third of Poupart's ligament. It inserts through the sheath of the rectus in the linea alba and crest of the pubis, and through the conjoined tendon into the spine of the pubis and iliopectineal line for about 4 cm. (i ^^ in. ). The transversalis does not come down so low as the internal oblique, because it arises from the outer third of Poupart's ligament instead of the outer half, as does the internal oblique. As already stated, the blended tendons of the external and internal oblique and transversalis muscles all pass in front of the rectus in its lower fourth. As the umbilicus is below the middle of the linea alba, this point, where the fold of Douglas is formed, is nearer to the umbilicus than it is to the symphysis (Fig. 390). VESSELS OF THE ABDOMINAL WALLS. The vessels of the abdominal walls comprise arteries, veins, and lymphatics. The arteries are superficial and deep ; of these the deep are the more important. The arterial twigs in the subcutaneous tissue are small. The superficial epigastric runs in a line from the femoral artery toward the umbilicus. The superficial circumflex iliac runs to its outer side toward the iliac spine, mostly below Poupart's ligament. Branches of these vessels may require the temporary application of a haemostatic forceps in the operations for hernia or appendicitis. The superior epigastric artery is one of the two terminal branches of the internal mammary. The other is the musculophrenic, which skirts the edge of the thorax. The internal mammary divides opposite the sixth interspace, and the superior epigastric, leaving the thorax at the lower edge of the seventh rib, enters the sheath of the rectus muscle and a few inches lower down enters the substance of the muscle, speedily breaking up into small branches. It is only large in size up toward the thorax, where we have seen it cut by a stab-wound, causing dangerous hemorrhage. It may also be wounded in operations and is to be sought for between the muscle and its posterior sheath, on a line continued downward from a point one centimetre to the outer side of the edge of the sternum. fascia. Fig. 39 1. — The nerves and blood-vessels of the anterior abdominal wall. The nerves are seen piercing the posterior layer of the sheath of the rectus to enter the muscle. The external and internal oblique have been removed exposing the nerves lying on the transversalis. at Poupart's ligament with the umbilicus. Opposite the fold of Douglas (linea semicircularis) it reaches the middle of the rectus, pierces the transversalis fascia, and enters the substance of the muscle. It sends branches to the outer edge of the muscle which are quite large and bleed freely when cut. It anastomoses above with the superior epigastric. It is a most important artery, as it is liable to be wounded in operations for appendicitis, etc. If cut it will require a ligature, and if pierced by a needle will bleed freely. As it passes upward from Poupart's ligament it lies to the upper and outer side of the femoral canal and may be wounded if the herniotomy knife is turned in that direction. A little higher it crosses the inguinal canal almost midway between the internal and external abdominal rings. An oblique inguinal hernia enters the canal to the outer side of this artery and a direct hernia to its inner side. The fold of the obliterated hypogastric artery is to its inner side. between the transversalis fascia and the peritoneum. When it reaches the anterior superior spine it passes between the transversahs and internal obHque muscles, and just above the crest divides into an ascending branch which goes upward toward the ribs and a posterior branch passing backward to anastomose with the iliolumbar. The ascending branch is large and bleeds freely when cut. It is not infrequently divided in operations for appendicitis in which the incision is carried far back. Its depth from the surface, between the transversalis and internal oblique muscles, should not be forgotten. Superficial Abdominal Veins. — The upper part of the abdomen is drained by small branches emptying into the superior epigastric, the intercostal, and laterally into the axillary veins. Below, there are the superficial epigastric and superficial circumflex iliac veins. In cases of obstruction to the flow of blood in the large deep veins the superficial veins become visible; thus a branch often becomes visible on the side running from the axillary vein to the superficial epigastric or femoral vein, — it is called by Braune (" Das Venensystem des menschlichen Kbrpers," 1884, JoesselandWaldeyer, Topog. chirurg. Auat., pp. 22, 147) the vena thoracica cpigastrica longa tcgumentosa (Fig. 392). Other small veins around the umbilicus become very much enlarged, and, branching in various directions around the umbilicus, have given rise to the term caput McdiiscB. Kelly (" Operative Gynecology," p. 48) describes two small veins running from the symphysis up to the umbilicus in the subcutaneous tissue on each side of the linea alba, and calls them celiotomy veins. Deep Veins of the Abdominal Walls. — The superior epigastric, deep epigastric, and circumflex iliac arteries are accompanied by veins. There is also a vein in the round ligament of the liver emptying into the portal vein, called by Schiff, and later by Sappey, the vena paninidilicalis {^lexnoires de I'acad. denied.", 1859). In some cases two small veins can be seen on the interior of the abdominal wall, running up to the umbilicus from the symphysis on each side of the median line, and two coming down to the umbilicus on each side of the median line. Lymphatics. — The superficial parts above the umbilicus are drained by lymphatics which empty into the axillary nodes; the vessels below the umbilicus empty into the oblique set of nodes in the groin. The lymphatics of the deep surface of the abdominal wall above the umbilicus drain into the mediastinal nodes, while those below drain into the pelvic lymphatics along the iliac arteries. Nerves. — The front and sides of the abdomen are supplied by the anterior and lateral cutaneous branches of the sixth, seventh, eighth, ninth, tenth, and eleventh intercostal nerves, the twelfth thoracic or subcostal, and the iliohypogastric and ilioinguinal branches of the first lumbar. The sides of thq abdomen are supplied by the lateral cutaneous branches which supply the skin as far forward as the rectus muscle. The recti muscles and skin overlying them are supplied by the anterior branches. These pass forward between the internal oblique and transversalis muscles to enter the sheath of the rectus, and, after supplying the muscle, pierce the anterior layer and are distributed to the integument above. The sixth and seventh supply the infrasternal region, the eighth about half way down to the umbilicus, the ninth just above the Fig. 392. — Obstruction of the right iliac vein from phlebitis. The vena thoracica epigastrica longa is seen running from the groin up to the axilla. above the pubes. The iliohypogastric emerges through the external oblique about 2 or 3 cm. above the external ring, while the ilio-inguinal emerges through the external rinoand supplies the parts adjacent. From this distribution it is evident why disease posteriorly, such as caries of the spine or pleurisy, will cause pain to be complained of in the corresponding distribution anteriorly. Incisions through, or along the outer edge of the rectus, will divide the nerves supplying it, and cause paralysis of the muscle. Incisions made across the lateral muscles of the abdomen "cannot be efficiently repaired by sewing the cut muscles together, because this does not restore the function of the nerves which have been divided. essarily wounding the muscles, arteries, and nerves. It having been found that mcisions through fascia alone are more liable to be followed by hernia than those through muscles, incisions through the Hnea alba and lineae semilunares are to be avoided. Incisions through the recti muscles are best made near their inner edge. If made in the outer edge the nerves supplying th muscle will be divided, causing subsequent paralysis and weakness. If made through the middle, only the nerves supplymg the inner half will be divided, but the main trunks of the 'deep and superior epigastric arteries will be cut and cause troublesom.e bleeding. There is least harm done by making the incision through the inner edge of the muscle. If the method of Battles is resorted to, of dividing the outer edge of the sheath of the rectus longitudinally and displacing the muscle inward, or of dividing the muscle itself longitudinally, then not only are large branches of the deep epigastric arteries met but in dividing the posterior layer of the sheath the nerves are divided. If the rectus is divided transversely (as Kocher advises in operations on the gall-bladder) care must be taken to avoid wounding the nerves ; he claims that the scar acts only as an additional linea transversa and does not injure the functions of the muscle. Injury to the nerves and rectus muscle both can be avoided by incising the sheath transversely and then pulling the rectus to one side (Weir), or by dissecting up the sheaths of both recti transversely and separating the muscles in the median line ( Pfannenstiel and Stimson). Incisions through the transverse muscles if made in the same direction through all three muscles are bound to cut some in a direction more or less transverse to their fibres. The incision of McBurney — for appendicitis — avoids wounding the muscles. He separated the external oblique in the direction of its fibres downward and inward, crossing a line from the anterior superior spine to the umbilicus, 4 to 5 cm. (i^ to 2 in. ) to the inner side of the spine. The internal oblique and transversalis are then separated in the direction of the fibres and drawn in the opposite direction. This method is applicable where small openings suffice ; but when large incisions are essential, as in bad suppurating cases of appendicitis and in operations to expose the kidney and ureter, it is customary with many to incise all the muscles in the line of the fibres of the external oblique. Should nerves be encountered they are if possible to be drawn aside. In this incision the internal oblique and transversalis are incised nearly transversely, and bleeding from the deep circumflex iliac artery which runs between them will be encountered. Edebohls exposes the kidney by incising alongside of the outer edge of the erector spinte muscle. The latissimus dorsi is separated in the direction of its fibres, the lumbar aponeurosis is incised and kidney exposed. A normal kidney can be delivered through this incision, but not one much enlarged. When the kidney is much enlarged the incision is to be prolonged anteriorly along the crest of the ilium (see page 396). The relation of the pleura is to be borne in mind: it crosses the twelfth rib about its middle to reach its lower edge posteriorly. Hence the upper end of the incision should always be kept anterior to it (see section on Pleura). HERNIA. Abdominal herniae occur most often in the umbilical and inguinal regions. Sometimes the recti muscles separate and a median protrusion results ; or they may occur at the site of a previous operation. Umbilical herniae are of three kinds, congenittd, infantile, and acquired. Congenital timbilical /ier?iia"\s due to a developmental defect. In the embryo the umbilicus transmits ( i ) the viteUine duct, passing from the umbilical vesicle to the small intestines; (2) two umbilical arteries, w^hich inside the abdomen are called hypogastric and pass to the internal iliacs through the superior vesicals; (3) one umbilical vein passing to the liver through the round ligament; (4J the stalk of the allantois, which, on entering the abdomen, is called the urachus, and passes down to the bladder. At birth ihese structures, with a myxomatous tissue called Wharton's jelly, are covered with amniotic tissues and form the umbilical cord. If development is interfered with, a cleft is left in the umbilical region into which intestine or other organs may protrude. If only intestine protrudes, it pushes up into the umbilical cord, and constitutes a congenital umbilical hernia. If the intestine is included when the cord is ligated, death from strangulation will ensue; hence the danger of this form of herniae. If the urachus remains patulous it may form a urinary fistida. The hypogastric arteries become obliterated and, opposite Poupart's ligament, have twc fossae, one to their outside and one to their inside. Into these fossae direct ingiinal hernicC may pass. The persistence of the vitelline duct may cause a finger-like projection, called Meckel's diverticn/uni, on the ileum, about 2 or 3 feet abo\'e the ileocaecal vahe. Sometimes a band passes from Meckel's diverticulum to the umbilicus and causes strangulation of other coils of the intestine. We have operated on one such case. The umbilical vein becomes obliterated and the small vein found in the round ligament of adults, called by Schifi the pai^umbilical, is a new formation, and not the original fetal umbilical vein. Infantile umbilical hernia is the common form which appears soon after birth. It does not contain omentum so constantly as does adult hernia, because it does not hang so low, nor is it so well developed. Acquired umbilical hernia is the form seen in adults. The presence of the urachus and hypogastric arteries so strengthens the lower edge of the umbilical ring that hernial protrusions make their exit above, hence the hard edge of the ring is nearer the lower end of the hernial sac. These herniae almost always contain omentum, and either transverse colon or small intestine. The contents of the herniae are usually matted together and are adherent. The coverings are very thin, consisting of skin and peritoneum, with a small amount of transversalis fascia and scar-tissue between. Unless extreme care is exercised in operating, the first cut will pass into the sac and wound the intestines or omentum. There are two modes of operating on these herniae. In one operation the sheaths of the two recti muscles are opened and the muscular fibres and sheaths are brought together and sewed in the median line; in the other, two flaps ally or transversely. Inguinal Hernia. — There are two forms of inguinal hernia, the congenital and the acquired. These are subdivided into several varieties which can only be understood by having a knowledge of the development and construction of the parts invoh'ed. Development and Descent of the Testis. — The testicle originates in the lumbar region inside of the abdomen about the third month. It is behind the peritoneum and has a fold of peritoneum, the plica vascidaris , passing upward from it, containing the spermatic artery and veins, and a fold passing downward to the inguinal region and into the scrotum called the gubernacnlum. By the fifth or sixth month the testicle has reached the abdominal wall at the internal ring, after which it enters the inguinal canal to pass into the scrotum in the eighth or ninth month of fetal life. A process of peritoneum — the vaginal process — precedes the passage of the testicle into the scrotum. The neck of the vaginal process is called the funicular process. Soon after birth the vaginal process becomes occluded, first at the internal ring, and thence downward until the testicle is reached, where the unobliterated portion forms the tunica vaginalis testis. Congenital Hernice and Hydrocele. — There are several forms of congenital herniae. They are so named, not because they exist from birth, but because they are caused by developmental defects which exist at birth (Fig. 394). Vaginal he7'nia into the processus \aginalis, commonly known as congenital hernia, is where the vaginal process remains entirely open and the intestine passes down to the testicle. In this form the testicle is found protruding into and at the bottom of the hernial sac. Funicular Hernia. — In this form the vaginal process is occluded just above the testicle, but the funicular process above remains open and the intestine descends into it. Encysted Hernia. — Here the vaginal process is occluded at the internal ring only, the remainder forming a continuous sac below containing the testicle. When the intestine descends it pushes this septum, like the finder of a glove, down into the cavity containing the testicle. In operation, two serous layers would be incised, within one of which is the testicle and within the other the intestine. Infantile Hernia. — In this form also the vaginal process is occluded only at the internal ring. As the intestine descends it forms a sac posterior to the point through in exposing the intestine and the sac is posterior to the testicle. Hydrocele. — Hydrocele is an accumulation of fluid in the tunica vaginalis testis. It is usually an acquired affection of adult life, and then does not appear to be dependent on congenital anomalies. Encysted Hydrocele of the Cord. — This consists of a cystic collection in the course of the spermatic cord. It makes its appearance in infancy and childhood, and is due to some portion of the funicular or \'aginal process failing to become obliterated. Serum accumulates in this unoccluded portion, forming a small serous cyst. Sometimes a small opening furnishes a communication with the abdominal cavity, forming a congenital hydrocele. In this case the contents of the cyst can be pressed back into the abdominal cavity only to reappear. Should the communicating opening become dilated by a descending coil of intestine, a hernia into the funicular process would be the result. Hydrocele of the Canal of Nicck. — The inguinal canal in the female transmits the round ligament, and sometimes a finger-like extension of the peritoneum resembling the vaginal process in the male. Accumulation of fluid may occur in this in the same manner as hydrocele of the cord is formed in the male. It is then called hydrocele of the canal of Nuck. Acquired Inguinal Hernia. — Acquired inguinal herniae may be either of the indirect or direct kind. To understand them one must know the construction of the inguinal canal and spermatic cord. The Spermatic Cord. — As the testicle descends it leaves in its wake the vas deferens, the essential part of the spermatic cord. It carries with it the spermatic artery, from the aorta, the pampimforin plexus of veins, and the artery of the vas from the superior vesical. The vas deferens with its artery lies posteriorly and the spermatic artery and pampiniform plexus are anterior. The cremasteric branch of the deep epigastric supplies the cremaster muscle. Inguinal Canal (^Canalis Inguinalis^. — This runs from the external to the internal abdominal ring and is about 4 cm. ( 1 3/^ in. ) in length. The external rijig {^annulus ijiguinalis subcutaneus^ (Fig. 395) barely admits the tip of the finger ; it lies immediately to the outside and above the spine of the pubis. It is formed by a splitting of the fibres of the external oblique aponeurosis into two columns or pillars. The external column {^crus inferius) blends with Poupart's ligament, passes beneath the cord, and inserts into the spine of the pubis. The internal column (^crus superius') inserts into the crest and anterior surface of the body of the pubis. The fibres running across from one column to the other are the intcrcolumnar fibres (Jibrcs intercruralis) and are prolonged over the cord as the intcrcolumnar fascia (Fig. 395). The internal ring {annnlus inguinalis abdominalis) is the opening in the transversalis fascia where the cord enters the canal. It is 1.25 to 2 cm. (^ to ^ in. ) above the middle of Poupart's ligament. This brings it to the outer side of the external iliac artery. The body being upright, the inguinal canal has an anterior and a posterior wall and a roof and floor. The anterior wall (nearest to the skin) is formed by the aponeurosis of the external oblique, and by the internal oblique muscle for its outer third and sometimes even its outer half. The posterior zcall is nearest to the vertebral column. It is formed by the transversalis fascia and at its inner third the con- joined tendon. The I'oof, nearest to the head, is formed by the arching fibres of the internal oblique muscle and — still farther above — the transversalis. The Jloor is nearest to the feet. The cord rests on Poupart's ligament with some of the fibres of the cremaster muscle. To the inner side of the internal ring and almost midway between it and the external ring runs the deep epigastric artery, it is between the transversalis fascia and peritoneum, in the subperitoneal fat. Coverings of an Indirect or Oblique Hernia. — As the intestine descends to form an oblique inguinal hernia it pushes in front of it the following structures : peritoneum, subperitoneal fat, transversalis (infundibuliform) fascia, internal oblique muscle (cremaster), external oblique aponeurosis (intcrcolumnar fascia), subcutaneous tissue, and skin. These structures are therefore cut in opening the sac to expose the intestine. The hernia always descends in front of the cord and testicle, hence these are posterior. The site of strangulation may be either at the external ring as the hernia passes through the external oblique muscle or at the internal ring as it passes through the trans\'ersaHs fascia. The deep epigastric artery is always alono- the inner side of the neck of the sac, therefore division of the striciiire must be either upward or up and out, never inward (Fig. 397). Operation for Radical Cure. — This has been systematized by Bassini of Padua. The neck of the sac having been exposed by incising the aponeurosis of the external oblique, and the cord separated from it, the intestine is to be replaced and the sac ligated as high as possible and cut away. The cord is then raised and the arching fibres of the internal oblique (and transversalis) are sutured beneath it to Poupart's ligament. The cord is to be replaced, and the cut edges of the external oblique are sewed together down to the external ring, leaving sufficient room for the exit of the cord (Fig. 398). Direct Inguinal Hernia. — This is so called because it comes directly through the abdominal walls, and not obliquely down through the inguinal canal. It makes its appearance in the neighborhood of the external ring (Figs. 399 and 400). Hesselbach' s Tria7igle. — Hesselbach's triangle is seen from the interior of the abdomen; it has on its outer side the deep epigastric artery, on its inner side the edge of the rectus muscle, and as its base Poupart's ligament. Direct inguinal hernia pierces the abdominal walls through this triangle. On looking at the abdominal wall from the inside, five folds are seen. In the median line the urachus passes from the umbilicus to the top of the bladder; farther out are the folds formed by the obliterated hypogastric arteries (plica hypogastrica) ; and still farther out the folds containing the deep epigastric arteries (plica epigastrica). The fossa between the urachus and hypogastric artery is called the internal ingidnal fossa (fovea supT-avesicalis) ; that between the hypogastric and deep epigastrrc arteries, the middle inguinal fossa (fovea ingninalis medialis), and that to the outside of the epigastric artery the external ingiiijial fossa (fovea ingiiiyialis lateralis). An indirect or oblique inguinal hernia enters the abdominal walls at the external inguinal fossa, to the outer side of the epigastric artery. A direct hernia almost always enters the middle inguinal fossa between the hvpogastric and epigastric arteries. The hypogastric fold passes up behind the middle of the external ring close to the outer Coverings of a Direct Inguinal Hernia. — The conjoined tendon is prolonged outward from the edge of the rectus muscle two-thirds of the distance to the epigastric artery, and sometimes more. A direct hernia piercing the abdominal wall to the inside of the hypogastric artery (very rare) will push in front of it the peritoneum, subperitoneal fat, transversalis fascia, conjoined tendon, and intercolumnar fascia, making its exit at the inner side of the external abdominal ring. The common site is just to the outer side of the obliterated hypogastric artery, and it pushes in front of it the conjoined tendon and intercolumnar fascia, and makes its appearance at the outer side of, or through, the external abdominal ring (Fig. 400; . If it pierces the middle inguinal fossa farther out, and just to the inside of the epigastric artery, it passes to the outside of the conjoined tendon, and is covered instead by the cremaster muscle. Division of the strichirc which occurs here must be made upward and inward, because to its outer side lie the epigastric vessels. Radical Cure of Direct Inguinal Hernia.— When the conjoined tendon is sufficiently thick and strong it is brought down and sewed to Poupart's hgament beneath and behind the cord, thus closing the hernial opening. When it is very weak and thin, the edge of the rectus muscle is dragged downward and out\\ard and sewed to Poupart's ligament (Bloodgood), then the conjoined tendon (Fig. 401) is brought down in front of it and sewed to Poupart' s ligament, and the external ring narrowed so Fig. 402. — Radical cure of direct inguinal hernia. The aponeurosis of the external oblique has been divided and drawn back. The conjoined tendon has been drawn upward toward the median line. The transversalis fascia covering the rectus has been incised and the edge of the muscle has been drawn out and down and sewed to the edge of Poupart's ligament (Bloodgood). The operation is completed by sewing the conjoined tendon to Poupart's ligament, replacing the cord on it, and stitching the edges of the external oblique together down to the external ring. Femoral Hernia. — Femoral hernia is always acquired and descends through the femoral canal beneath Poupart's ligament to make its appearance at the saphenous opening on the thigh. Beneath the inner end of Poupart' s ligament is the iliopectineal line of the horizontal ramus of the pubic bone. The two form an angle with the spine of the pubis as its apex. Gimbernat's ligament is the prolongation of Poupart's ligament from the spine of the pubis for about 2 cm. (^ in.) out on the iliopectineal line. From the iliopectineal line the pectineus muscle proceeds downward and outward beneath Poupart's ligament to below and behind the lesser trochanter of the femur. Farther out beneath Poupart's ligament run the femoral vein and artery, the latter being to the outer side of the vein. Between the femoral vein and Gimbernat's ligament is left a space i to 2 cm. ( \| to i in.) wide. This space is called the femoral canal. It is through this canal or opening that femoral hernia descends. T\\q fenioj'al sheath is the continuation downward of the transversalis fascia which is prolonged from the interior of the pelvis over the femoral artery and vein and between the vein and Gimbernat's ligament so as to form three compartments. The outer contains the femoral artery, the middle the femoral vein, and the inner is the femoral canal. The femoral canal is from i to 2 cm. ( i to 4 in. ) long and runs from the abdominal side of Poupart's ligament to the upper edge of the saphenous opening and lies between the femoral vein and Gimbernat's ligament. Its lower extremity is closed by the meeting of its sides. Above, or superficial to it, is Poupart's ligament, and beneath it is the horizontal ramus of the pubis and pectineal fascia covering the pectineus muscle. It is filled with loose connective tissue, fat, and lymphatics, and sometimes contains a lymphatic node, forming all together what has been called the septum crurale. It will thus be seen that the septum crurale is continuous with the subperitoneal fatty tissue (Fig. 403). Coverings of a Femoral Hernia. — When a femoral hernia descends, the intestine pushes in front of it the peritoneum, septum crurale (subperitoneal tissue), and the femoral sheath (transversalis fascia) and makes its appearance at the saphenous opening. The cribriform fascia closing the saphenous opening gives it a covering, and also the subcutaneous tissue and skin above. Saphenous Opening. — This has its centre 4 cm. (i^/^ in.) below and to the outer side of the spine of the pubis. Its margin blends above with Poupart's ligament to proceed to the spine of the pubis. Its outer and upper edge is marked, forming tha falciform process or ligament (of Burns ). The upper inner portion of the falciform process is attached to the iliopectineal line and spine of the pubis and, blending with Poupart's ligament above, is called Gimber)iat's ligament (ligamentum lacunare) (Fig- 404)' The part of the fascia lata forming the falciform process thins out over the femoral artery and becomes the cribriform fascia {fascia cribrosa) as it passes from the inner side of the femoral artery on to the femoral vein to blend with the pubic fascia to the inner side. The superficial epigastric, superficial circumflex iliac, and superficial external pudic arteries and veins all pierce this cribriform fascia, as do also the superficial lymphatics and the long or internal saphenous vein. Division of Stricture. — If Gimbernat's ligament is the constricting band the incision is to be made in an upward and inward direction. If the upper portion of the falciform process is the constricting part the incision should be made directly upward into Poupart's ligament. around the neck of the sac, the stricture is best cut from without inward. Radical Cure of Femoral Hernia. — The intestine and omentum having been replaced, the neck of the sac is ligated as high up as possible and cut away or, preferably, the two ends of the ligature are brought up through the aponeurosis of the external oblique and tied on its surface just above Poupart's ligament. To close the femoral canal two or three sutures are inserted as follows: If the hernia is on the right side, the needle is passed downward through the inner end of Poupart's ligament, close to the spine of the pubis, into the pectineal or pubic portion of the fascia lata, and brought out alongside of the femoral vein. It is then inserted again through the edge of the falciform process and the suture tied, thus pulling the falci- form process and the lower edge of Poupart's ligament down on the fascia covering the pectineal muscle. Two or three sutures are all that are required. Another way of inserting the sutures is longitudinally, instead of transversely. The first would be close in to Gimbernat's ligament, the second a little farther out, and the third as close to the femoral vein as possible (Fig. 406). Muscles. — The quadratus lumborum muscle arises from the transverse processes of the lower four lumbar vertebrce. the iliolumbar ligament, and 5 cm. (2 in.) of the iliac crest. It inserts into the posterior half of the last rib and transverse processes of the upper four lumbar vertebrae. The erector spinae is the muscular mass which fills the groove to the outer side of the spinous processes. It arises from the spines of the lumbar vertebrae, the back of the sacrum, the sacrosciatic and sacroiliac ligaments, and about the posterior fourth of the crest of the ilium. It inserts into the posterior portion of the vertebrae and ribs above. The latissimus dorsi arises from the spinous processes of the lower six thoracic \'ertebrae and the vertebral aponeurosis, which is attached to the spinous processes of the lumbar vertebrae, the posterior surface of the sacrum, and the posterior third of the crest of It will thus be seen that while the direction of the outer fibres of the latissimus dorsi is from below upward and forward, the direction of those of the quadratus lumborum is upward and backward. It will also be observed that the attachment of the quadratus lumborum is farther out on the crest of the ilium than is that of the latissimus dorsi, reaching about its middle (Figs. 408, 409 and 410). Fascias. — The lumbar fascia (fascia lumbodorsalis), so called, is the continuation backward of the posterior aponeurosis of the transversalis and internal oblique muscles to the spine. When the aponeurosis, from which these two muscles spring, reaches the outer edge of the quadratus lumborum, it splits; one thin layer goes on its \'entral surface to be attached to the roots of the transverse processes of the vertebra; the other thick posterior layer, on reaching the edge of the erector spinae muscles di\-ides into two, the anterior of which covers the dorsal surface of the quadratus lumborum and the ventral surface of the erector spinse to attach itself to the tips of the transverse processes, while the posterior layer' passes over the dorsal surface of the erector spinae to be attached to the spinous processes of the lumbar vertebrae. These three layers are called the anterior, middle, and posterior layers of the lumbar fascia (see Fig. 410). The anterior layer is attached to the tip of the twelfth rib and arches inward to the transverse process of the first or second lumbar vertebra, to form the external arcuate ligament of the diaphragm. It is practically continuous with the transversalis fascia. Petit's Triangle (trigonum lumbale i. — Above the middle of the crest of the iUum is a small triangular space formed by the edge of the external oblique in front, of the latissimus dorsi behind, and the crest of the ilium below. Its floor is formed by the internal oblique muscle, and it is called the triangle of Petit. It forms a weak point in this region through which collections of pus or, more rarely, \'entral herniae, may make their appearance (Fig. 407). Fascial Triangle. — h bove and a little posterior to Petit' s triangle is another triangular space. Its base is the twelfth rib, its anterior side is the posterior edge of the internal oblique, and posterior side is the outer edge of the quadratus lumborum. It is also called the triangle of Grynfelt and Lesshaft. The lower portion of the kidney lies immediately beneath it and the latissimus dorsi covers it (Figs. 408 and 409 J. Lumbar Abscess. — Pus in the lumbar region usually originates from caries of the vertebrae, from calculus or other renal or perirenal affections, or, if on the right side, sometimes from disease of the appendix. Empyemas may likewise point in this region. Pus starting from the vertebrae may push its way outward under the transversalis aponeurosis (anterior layer of the lumbar fascia ) and perforate the transversalis muscle where the iliohypogastric, ilio-inguinal, and last thoracic nerves enter and thus reach the under surface of the internal oblique and perforate this muscle to find its exit at Petit's triangle. Pus may also perforate the floor of the fascial triangle and follow the anterior surface of the latissimus dorsi down until it points in the angle between the posterior portion of the crest of the ilium and the spine. The quadratus lumborum muscle is thin, and its outer edge, which is not covered by the erector spinae muscle, is readily pierced by pus. The erector spina is a thick muscle covered both anteriorly and posteriorly by the thick middle and posterior layers of the lumbar fascia, hence pus does not pierce it but always goes around its outer side. Lumbar incisions are made to evacuate pus or to operate on the kidney. Incisions to evacuate pus should be made obliquely from the outer edge of the quadratus lumborum in order to avoid wounding the nerves. Lo7igitudinal Incisioyi. — If it is desired to expose the kidney, a straight incision 10 cm. (4 in.) long may be made between the last rib and middle of the crest of the ilium along the outer edge of the quadratus lumborum. This may sometimes necessitate cutting the last thoracic nerve near the rib and the iliohypogastric and ilio-inouinal nerves near the crest. They should if possible be pulled aside, but ii cut are to be stitched together again. This gives only sufficient room to bring a normal-sized kidney out of the wound; if the kidney is enlarged, Edebohls recommends prolonging the incision along the crest of the ilium. This longitudinal incision lies just back of the external oblique, traverses in its upper part the latissimus dorsi (the fibres of which may be parted by blunt dissection; then the lumbar fascia or anterior edge of the quadratus lumborum muscle, and lastly the transversalis fascia behind the peritoneum (Fig. 411). Oblique Incision. — When an incision for enlarged kidneys, tumors, or abscesses is desired it can be made obliquely downward and forward from the twelfth rib — anterior to its middle — toward the anterior portion of the crest of the ilium. This parts the fibres of the external oblique and di\ides the fibres of the transversalis muscle obliquely, and those of the internal oblique almost transversely, but the nerves (twelfth thoracic and iliohypogastric) are more readily drawn aside than if the longitudinal incision is used. Care is to be taken not to go farther back than the middle of the twelfth rib, because the pleura usually crosses at that point to reach the lower edge of the rib, or even a little below it at its posterior extremity. As it is sometimes difficult to identify the twelfth rib, because it may be so short as to be hidden beneath the muscles, the most certain way is to count downward from the angle of the sternum opposite the second costal cartilage. There may be some bleeding at the lower portion of the wound from the ascending branch of the deep circumflex iliac artery near the anterior portion of the crest of the ilium. THE INTERIOR OF THE ABDO.MEX. The abdominal ca\itv extends only to the brim of the pelvis; the pelvic cavity is separate. The peritoneal cavity is not synonymous with the abdominal ca\ity: some of the abdominal organs project comparatively little forward into it and, as in the case of the kidneys, may be only partly covered with the peritoneum. The peritoneal cavity includes the pelvis, so that an infection of the pelvic peritoneum of necessity in\-olves a part of the general peritoneal cavity. various abdominal and pelvic organs grow. As the organs increase n size they push farther into the abdominal cavity and the peritoneum covers more \ A their surface, until in some cases the two layers (anterior and posterior) meet; thus the organ is left hanging by its peritoneal pedicle. The peritoneum covering the organs is called the visceral peritoneum, that lining the walls of the abdominal cavity the parietal peritoneum. Those parts of the peritoneum joining the visceral and parietal layers receive various names. Sometimes they are called ligaments, — thus we have the various ligaments of the liver, the coronary, lateral, and suspensory ; of the spleen ; of the uterus; bladder, etc. Sometimes they are called omenta, — thus we have the greater omentum, the lesser or gastrohepatic omentum and the gastrosplenic omentum. Sometimes they receive the name of mesentery, which is applied to the small intestine, and mesocolon, as applied to the large intestine. From this arrangement it is evident that there is some portion of every abdominal and pelvic organ that is not covered by peritoneum. In some organs, as the small intestines, the uncovered part is very small, being at the attachment of the mesentery. In other organs, as the kidneys, it is very large, embracing all their posterior surface. In operating on the abdominal or pelvic organs these attachments are of importance, as a knowledge of them enables the surgeon — for example, in operating on the kidney for renal calculus— to complete his procedures without wounding the peritoneum or opening the peritoneal cavity. The upper and lower limits of the peritoneum are also important, as it is liable to be wounded in operations on the chest and the organs of the pelvis. is of service both in diagnosis and operative procedures. Viewing the body in an a7iteroposterior section (Fig. 412), and beginning at the umbilicus, the peritoneum is seen to pass upward on the posterior surface of the anterior abdominal wall until it reaches the under surface of the diaphragm, which it covers, to the upper posterior surface of the liver, where it forms the coronary ligament on the right side ard the left lateral ligament on the left. It then covers the upper or parietal surface of the liver and curves around the anterior edge and the under or visceral surface as far as the transverse fissure. Thence it proceeds to the stomach, forming tne anterior layer of the lesser or gastrohepatic omentum. After covering the anterior wall of the stomach, it leaves the greater curvature to form the anterior layer of the greater omentum. It next passes to the transverse colon, which it covers and passes back to the spine at the lower border of the pancreas. It then goes downward, covering the transverse portion of the duodenum and forming the anterior layer of the mesentery. Ha\'ing covered the small intestine, it goes back to the spine, forming the posterior layer of the mesentery, and descends until it reaches the rectum. From the rectum it is reflected forward to the upper part of the \'agina and uterus in the female, forming the reeto-tderine pouch (or pouch of Douglas^ or on the bladder in the male, being at this point about 7.5 cm. (3 in.) distant from the anus. After covering the fundus and body of the uterus, it is reflected at the level of the internal os to the bladder, forming the uterovesieal fold. From the top of the bladder it passes up the abdominal wall to reach the umbilicus. The peritoneum lining the lesser cavity can be followed upward from the anterior surface to the pancreas. It ascends on the posterior abdominal wall to the under surface of the liver, forming the under layer of the coronary and left lateral ligaments. and at the transverse fissure is reflected to the posterior surface of the stomach, forming in its course the posterior layer of the gastrohepatic omentum. From the greater curvature it passes downward and then upward to the colon, forming the posterior layer of the greater omentum. From the posterior edge of the transverse colon it passes to the anterior surface of the pancreas, having in its course formed the upper (cephalad) layer of the transverse mesocolon. Viewing the body in transverse section. — On examining a transverse section made below the foramen of Winslow, the peritoneum is seen coming from the parietes and passing over the ascending colon, leaving its posterior surface uncovered. Thence it passes over the vena cava and spine, to go to the mesentery and small intestines. Returning to the spine, it passes over the aorta, and out over the descending colon, usually leaving a portion of its posterior surface uncoAcred. Thence it returns to the anterior parietes. In a section made passing through the foramen of Winslow (Fig. 413), the mode of formation of the lesser ca\ity of the peritoneum and the relation of the peritoneum to the stomach, spleen, and kidneys will be more readily understood. Beginning on the anterior abdominal wall, at the median line and proceeding to the right, the peritoneum is seen to enclose the round ligament of the liver, forming a mesentery for it named the falciform ligament. Continuing around, the peritoneum lines the inner surface of the anterior and lateral abdominal walls, covers the anterior surface of the right kidney, and, after forming the posterior wall of the foramen of Winslow, covers the vena cava, aorta, spine, and pancreas; it then passes over the left kidney THE ABDOMINAL VISCERA. 399 to go to the spleen, forming the anterior layer of the lienorenal ligament. It is then reflected from the spleen to the posterior surface of the stomach, forming the posterior layer of the gastrosplenic omentum. From thence it passes forward on the stomach, past the pylorus to the upper surface of the first portion of the duodenum. Here it winds around the hepatic artery, portal vein, and common bile duct to reach the anterior surface of the stomach. This reflection forms the free anterior edge of the foramen of Winslow. From the fundus of the stomach it passes to the spleen, forming the anterior layer of the gastrosplenic omentum. It winds around the outer or costal surface, and the inner or renal surface of the spleen, and thence passes to the left kidney, forming the posterior layer of the lienorenal ligament. After covering the outer portion of the kidney, it is reflected to the abdominal wall which it follows to the median line. The Transversalis Fascia. — Superficial to the peritoneum and between it and the structures which it covers is a layer of fibrous tissue which varies in thickness. The part which lines the muscles of the abdomen is called the transversalis fascia. It is thickest and most marked in the lower portion of the abdomen and accompanies the femoral vessels down the thigh. Subperitoneal Fat. — In certain locations there is more or less fatty tissue between the transversalis fascia and the peritoneum, and sometimes it is impossible to differentiate them. They blend in the region of the kidneys, the mesenteries, inguinal regions, etc. In the femoral canal the transversalis fascia is continuous with the sheath of the vessels and the subperitoneal fat with the septum crurale. The protrusion of this subperitoneal fat in the median line usually above the umbilicus forms the fatty herniae alluded to on page 371. The abdominal contents should first be studied as to their positions and general relations, so that they can be readily found and identified, and then studied as to their intimate relations to the immediate surrounding structures. By knowing the first, an operator is enabled to expose quickly the affected part, and by knowing the second he is enabled to carry out the desired procedures. While it is true that the presence of tumors or enlargement of the various organs may distort and displace them and so render their exposure and recognition difficult, nevertheless a knowledge of the normal relations is essential in order to solve the difficulties which arise in operating for or studying the various abdominal diseases and injuries. It must be borne in mind that the extent and position of the various organs is not always the same, even though they are not diseased; it is easier to find a distended than a contracted stomach; in some people the liver though not diseased may be lower than in others, etc. When the abdominal cavity is freely opened the general relation of the organs is visible as in Fig. 414. In the upper portion is seen the liver. Its edge usually is inclined upward toward the left, but sometimes it passes alm.ost transversely across. In the male its lower edge should be about even with the lower edge of the thorax (tenth rib) but in females it may be a finger-breadth lower. Its anterior edge i^ marked by the gall-badder and roujid ligament. The gall-bladder is liable to be a littl to the outside of its normal position at the upper extremity of the right hnea semilunaris. The round ligament reaches the liver not at the median line but 2.5 to 4 cm. (i to ly-z in.) to its right. The point at which the Hver crosses the median line is approximately 4 cm. (i^ in.) below the tip of the ensiform cartilage. The stomach is seen to the left of the liver, between it and the left costal cartilages. Frequently the stomach is seen to pass a little to the right of the median line, particularly if it is distended. A small portion only, 2.5 to 4 cm. (i to i^ in.), is seen in the median line and its lower border slopes up and to the left to disappear under the edge of the ribs. Immediately below the stomach lies the transverse colon, concealed beneath omentum. The omentum hangs down from the lower edge of the stomach and spreads over almost the whole of the abdomen below. It is almost always encountered in operating for appendicitis and is often found in a hernia. T\|ie gallbladder is almost the only organ below the liver and stomach which it is not liable to cover Not infrequently the omentum is not found spread out, but from the movements of the intestines it may lie between their coils or be displaced largely to the left The transverse colon passes upward and to the left ; it crosses the median line iust below the stomach and may reach as low as the umbilicus. Not infrequently, however there may be a coil of small intestine between the level of the umbilicus Fig. 414.— View of the abdominal organs in situ. Beneath the ensiform process is seen the liver with the round li^^ament to the right of the median line, below come the stomach, then the transverse colon, and lower down [hrsmafnXstinesov^ which i! spread the great omentum. In the right iliac region is seen the ascending colon and in the left the termination of the descending colon. of it and show itself between the stomach above and the transverse colon below. The Cizcu??i ,and the commencement of the ascendifig colon are almost always seen superficially in the right iliac fossa. The lower end of the caecum may reach as far forward as the middle of the inguinal (Poupart's) ligament, but when the ascending colon reaches the upper edge of the iliac crest it sinks backward out of The descending colon and sigmoid flexure are usually seen lying close to the abdominal wall somewhere between the left iliac crest and approximately the middle of Poupart's ligament. The amount visible is variable, — sometimes a considerable length is seen, at others only a single knuckle. Their presence and location are more uncertain than are those of the caecum and ascending colon on the right side. The small intestines fill the rest of the visible space. They enter the pelvis, usually are found in hernial sacs, and cover both the ascending and descending colon in the flanks. The coils in the upper and left portions of the abdomen are more likely to be jejunum, those in the lower and right portions are more likely to be ileum. Either may be found in the pelvis. upper two-thirds are more longitudinal, the lower third more transverse, the two parts making an angle of 60 to 70 degrees. The part just adjoining the pylorus is slightly enlarged when the stomach is distended, and is called the antrum. The stomach is spoken of as having anterior and posterior walls, but they could just as truthfully be called superior and inferior, especially when the organ is distended. When it is relaxed it tends to hang in a more vertical position, but when it is distended it rotates on a tranverse axis, the greater curvature coming forward, and the organ assumes a more horizontal plane. When the stomach is empty it may not be relaxed but contracted. This contraction is liable to be very marked toward the middle of the organ, producing the hour-glass stomach. At other times the contraction proceeds a variable distance from the pylorus toward the cardiac extremity. In such cases instead of being pear-shaped the stomach becomes more or less tubular so as to resemble the remainder of the intestinal canal. It then differs but little in appearance from the duodenum, and the position of the pylorus is not readily recognized. If, as may normally occur, the contraction extends well over toward the cardiac end, then liquids do not lodge in the stomach but pass almost immediately through it 26 / into the small intestine beyond. When this condition is found to exist, the stomach is to be recognized by its position, its attachments, and the thickness of its walls. It hangs suspended by its cardiac extremity from the oesophagus. This is beneath the seventh left costal cartilage, about an inch from the edge of the sternum and lo cm. (4 in.) from the surface; this brings it opposite the eleventh dorsal vertebra immediately in front of the aorta. The pvlorus lies just under the edge of the liver, either in the median line when the stomach is empty or, as is more often the case, 2.5 cm. (i in.) or more to the right of the median line — a little higher up than the gall-bladder or opposite the eighth right costal cartilage and on a level with the first lumbar vertebra. The pylorus is usually a little higher in women than in men. If the liver is contracted the pylorus and adjacent portion of the stomach may be in direct contact with the anterior abdominal wall. The lesser curvature is 7.5 to 12.5 cm. (3 to 5 in.) long and passes downward, forward, and to the right. In front are the diaphragm, abdominal parietes, and liver. Above are the lesser or gastrohepatic omentum, liver, and diaphragm. Below is the gastrocolic omentum, transverse colon, and gastrosplenic omentum. Percussion. — In physical diagnosis the size of the stomach is outlined by percussion, it being filled with air or gas to distend it. In the median line its resonance above will be limited by the edge of the liver; below, while usually 5 to 7,5 cm. (2 to 3 in.) above the umbilicus, it is not con.sidered to be dilated, especially in old people, unless it reaches below the umbilicus. It leaves the left costal margin opposite the ninth or tenth costal cartilage. In the left mammary line stomach resonance may reach up to the fifth or sixth rib, while farther to the left it reaches the spleen about in the midaxillary line. Traiibe' s semilunar space is limited above by the edge of the left lung, indicated by the sixth interspace ; externally bv the spleen, indicated by the midaxillary line; and internally by the costal margin. Normally this area is resonant from the presence of the stomach beneath, but pleural effusion causes it to be dull on percussion. THE STOMACH. 403 Blood Supply. — The aeliac axis gives off the gastric, hepatic, and splenic arteries, all of which give branches to the stomach. The gastric (or coronary) gives branches to the cesophagus and cardiac end and then runs along the lesser curvature to unite with the pyloric branch of the hepatic. It lies in the gastrohepatic omentum and sends branches anteriorly and posteriorly over the surface of the stomach (Fig. 416). The hepatic artery as it nears the pylorus gives off a pyloric branch which passes to the left along the lesser curvature, and a gastroduodenal branch, which divides into the superior pancreaticoduodenal to supply the duodenum and head of the pancreas, and the right gastro-epiploic artery which passes to the left along the greater curvature of the stomach. of the gastroduodenal artery. The more the stomach is distended the closer do the arteries of its greater and lesser curvatures lie to its walls. The fundus is supplied by the vasa brevia, small branches which leave the splenic artery in the gastrosplenic omentum. The veins follow the course of the arteries. The right gastro-epiploic empties into the superior mesenteric and the left into the splenic; they then enter the portal vein. The pyloric and coronary veins empty into the portal vein direct. The latter receives branches from the cesophagus which become varicose in cirrhosis of the liver. Lfymphatics. — The lymphatic nodes of the stomach are found principally around the regions of the pylorus — -inferior gastric nodes, and the lesser curvature and cardiac extremity — superior gastric nodes. The inferior nodes drain the greater curvature toward the pylorus while the superior nodes drain the lesser curvature and cardiac end. The fundus is drained by radicles which empty into the nodes which accompany the splenic artery. While some nodes may be found along the greater curvature toward the pyloric end, Cuneo and Poirier state that it is rare to find nodes in the middle portion of the greater curvature and quite exceptional to meet with them in the region of the fundus. of ulcer and carcinoma. Contracted stomach occurs either as a normal or pathological condition; it has already been alluded to on page 401. The contraction of the middle, producing the hour-glass shape, results from cicatrices and adhesions due to gastric ulcer. In cases of cesophageal stricture the contraction may be marked. It then embraces mainly the right third of the organ and the affected portion resembles the adjoining duodenum. Abstention from food in the course of an illness may also cause a contracted condition which one should be prepared to encounter in case of operation. A normal contracted condition of the right end of the stomach, often of a more or less hour-glass shape, is frequently encountered in autopsies when death has been- caused by disease of other organs (Fig. 417;. Dilation results from functional diseases as well as obstructive affections, such as ulcer or carcinoma, involving the pylorus. Distention causes the pylorus to pass from the midline 2.5 to 7.5 cm. (i to 3 in.) to the right. The organ becomes more horizontal and descends so that its lower border sinks below the umbilicus — its extreme normal level. Sometimes the greater curvature alone is lowered, while in others the gastrohepatic omentum is stretched and the pylorus as well as the greater curvature descends. This is called gastroptosis. The amount of distention is recognized by percussion, as pointed out on page 402, or by administering bismuth and examining by the Rontgen rays. Ulcer occurs most frequently along the lesser curv-ature; then the posterior wall, the region of the pylorus, the anterior wall, cardiac end, fundus, and greater curvature, in the order of frequency. The ulceration may open an artery, producing hemorrhage, or there may be adhesions to neighboring organs, resulting in the formation of abscess, or direct communication with the greater or lesser peritoneal cavity may be produced. Healing of ulcers near the pylorus may cause stenosis resulting in distention. Hemorrhage may occur from the vessels of the stomach walls or the vessels along the lesser curvature, the splenic or hepatic arteries or even the portal vein. One reason why the arteries along the curvatures are not still more frequently af?ected is because they often lie a short distance away from and not in immediate contact with the stomach walls. Adhesions to surrounding organs are least liable to form when the perforation is on the anterior wall. Then the larger peritoneal cavity is infected and a general peritonitis quickly ensues. A perforation on the posterior wall involves the lesser cavity of the peritoneum, and the infection must tra\^el first through the foramen of Winslow before a general peritonitis develops. Abscesses may form between the under surface of the liver and the stomach, and they have been known to penetrate the pleura, pericardium, and transverse colon. an actual specimen. 15 per cent, in other portions of the organ. Cuneo has shown that extension occurs in the lymphatic nodes along the lesser curvature, in those of the greater curvature along the right third of the stomach adjacent to the pylorus, and in the nodes around the pylorus and head of the pancreas. It has been noticed that there is no tendency to extension to the region of the duodenum. It will thus be seen that a line drawn from the junction of the right and middle thirds of the greater curvature to the cardiac extremity would have nearly all the nodes to the right. It is this portion which is removed in pylorectomy and partial gastrectomy; owing to the extension of the disease up the lymphatics of the oesophagus, enlarged nodes may sometimes be present in the left supraclavicular fossa or even in the left axilla. The tumor is usuallv felt in or near the median line, a variable distance above the umbilicus ; it may drag the pylorus lower down than normal. If the stomach is distended the tumor may be carried 5 to 7.5 cm. (2 to 3 in. ) to the right of the median line. If, as is not uncommon, the disease infiltrates the walls of the stomach, the tumor can be felt passing to the left side, disappearing under the costal margin. Adhesions and ulceration are common. They are so marked that peritonitis from acute perforation is moderately rare. The adjacent organs are matted togetherand purulent collections are liable to occur. The ulceration may open into adjacent organs, as the colon. The colon may be adherent to the stomach and the large omentum contracted into a roll. The adhesions and pressure from the growth often interfere with the biliary ducts, and jaundice ensues ; interference with the portal vein and vena cava causes ascites, and thrombosis of the veins sometimes occurs. In this disease, as in gastric ulcer, adhesions are least liable to form on the anterior wall, and here perforation requiring operation is most likely. The following operations are performed on the stomach : gastrotomy, or the opening of the stomach to remove foreign bodies or to treat ulcers ; gastrostomy^ or the making of a gastric fistula to introduce food , pyloroplasty, or the widening of a constricted Y>y^or\x'i; pyloredomy, for the removal of cancerous or strictured pylorus; gastrectomy, or the removal of a part or the whole of the stomach; gastroplicaiion, or the folding of the walls to reduce its size; 2xvdi gastro-enterostomy, or the establishing of a fistula between the stomach and the small intestine. Technic. — The incision for gastrostomy is 4 cm. (i^ in.) long, over the outer third of the left rectus muscle, beginning 2 cm. ( ^ in. ) below the edge of the ribs. The fibres of the rectus are to be parted by blunt dissection from above downward, as this is less apt to tear the lateral branches of the superior epigastric artery than if made in the opposite direction. The incisions for pyloroplasty and partial or complete gastrectomy are made in or near the median line and reach from the tip of the ensiform cartilage to the umbilicus. That for pyloroplasty is placed usually to the right of the median line, all others to the left. In incising to the right of the median line the incision should not be carried down to the umbilicus or the round ligamen- will be cut. The incisions are placed to one side of the median line in order to open the sheath of the rectus and pass through the muscular fibres, thus allowing of a more secure closure of the wound and diminishing the liability to hernia. In incising the posterior layer of the sheath of the rectus and peritoneum one should avoid wounding the edge of the liver, which crosses the median line midway between the xiphosternal articulation and umbilicus, being higher or lower according to its size. The stomach is recognized as lying immediately below and in contact with the under surface of the left lobe of the liver. If in doubt, follow the under surface of the liver to the transverse fissure, thence over the lesser or gastrohepatic omentum to the lesser curvature of the stomach. The omentum may present in the wound instead of the stomach. It is to be pushed downward and the stomach sought for under the liver. The transverse colon should not be mistaken for the stomach. It lies under the omentum and can be identified by its longitudinal bands. In operating on the pylorus it may be found lying in the median line or 5 cm. (2 in.) or even 7.5 cm. (3 in.) to the right. The normal pylorus will readily admit the index finger. The incision advised by Finney for pyloroplasty is 15 to 20 cm. (6 to 8 in.) long through the right rectus muscle. Partial gastrectomy is the operation usually done for carcinoma. Pylorectomy is too incomplete and total gastrectomy is too dangerous. In performing a partial gastrectomy, as done by the Mayo brothers, an incision just to the left of, or in, the median line is made from the ensiform process to the umbilicus. The gastrohepatic omentum is then ligated from the pyloric end toward the cardiac end, well beyond the limits of the tumor. The ligatures are to be placed close to the liver and sufiiciently far away from the lesser curvature to allow of the removal of the lymphatic nodes lying along it. The gastric artery is ligated below the cardiac opening, where it reaches the lesser curvature (see Fig. 416, page 402). The pyloric branch of the hepatic is ligated as it reaches the stomach. Ligate the gastroduodenal artery behind the pylorus and the gastro-epiploica sinistra on the greater curvature; the gastrocolic omentum is then to be ligated between the two. Care is to be taken not to ligate the colica media in the transverse mesocolon beneath or gangrene of the colon will result. The duodenum is then clamped and cut, and also the stomach. in what has been called the Hartmann-Mikulicz line (Fig. 416), which will remove most of the lesser curvature and at least a third of the greater curvature. The two cut ends are then closed with sutures and the lowest portion of the remainder of the stomach connected with the ileum either anteriorly or posteriorly. In performing a gastro-entcrostomy the upper portion of the jejunum is brought up and anastomosed with the anterior or posterior wall of the stomach. If the omentum is not seen at once on opening the peritoneum it will, perhaps, be found lying rolled up along the lower border of the stomach. It is to be brought out of the wound and turned upward. On its lower surface is seen the colon running transversely from right to left. Follow the transverse mesocolon down to the spine and the commencement of the jejunum will immediately be felt and can be seen coming through the mesocolon, with the ligament of Treitz running from its upper border to the parietal peritoneum. Follow the jejunum down for 40 cm. (16 in.) and bring it up in front of the great omentum and colon and anastomose with the lower border of the stomach anteriorly, preferably near the pyloric end. If it is Duodenojejunal flexure Fig. 418. — Posterior gastro-enterostomy. The omentum and colon have been turned up and the two openings shown in the stomach and commencement of jejunum are to be sewn together along their edges, thus establishing a communication between the stomach and small intestine. desired to do a posterior gastro-enterostomy the transverse mesocolon is divided and the stomach pushed forward through the opening (Fig. 418). The commencement of the jejunum as it emerges from the transverse mesocolon is then brought up and anastomosed with the posterior wall of the stomach. THE SMALL INTESTINE. The small intestine begins at the pylorus and ends at the ileocaecal ^•al\'e. It has an average length of 6.75 metres (22 ft. 6 in.) in the adult, independent of the age, weight, and height of the individual (Treves). Jonnesco gives its length as 7.5 metres (24 ft. 7 in.) and Sappey as S metres (26 ft. 3 in.). The duodenum is about 25 to 30 cm. (10 to 12 in. ) long, and two-fifths of the remainder, or about 8^ ft., is jejunum, and three-fifths, or about I2j4 ft., is ileum. The duodenum is the thickest, widest, and most fixed portion of the small intestine. Its diameter is from 3.75 cm. to 5 cm. (i^ to 2 in. ) and its muscular and mucous coats are thicker than those of the jejunum or ileum. It also possesses in its upper half the glands of Br2inna' {glandiilce duodenalcs^ in the submucous coat It is thus seen that in its structure it resembles more the stomach than the intestine and, like the stomach, is especiallv prone to ulcer. While carcinoma frequently originates at the pylorus and extends to and involves other parts of the stomach, it does not tend to involve the duodenum. This is probably due to the lymph stream from the pylorus running toward the stomach and away from the duodenum. The duodenum is also of interest in consequence of its intimate relation to the biliary passages and gall-bladder as w^ell as to the pancreas and its ducts. Inflammations, such as accompany gall-stones, frequently give rise to adhesions, to relieve which operations are performed. The second portion of the duodenum is sometimes opened in order to extract a biliary calculus impacted in the ampulla of Vater at the mouth of the common bile-duct. The upper portion of the duodenum in Finney's operation for pyloroplasty is slit down from the strictured pylorus and sewed to a corresponding slit in the stomach, thus making a large communication between the duodenum and the stomach and eliminating the stricture. In shape the duodenum resembles a horseshoe. It begins on the right side of the body of the first lumbar vertebra and ends on the left side of the body of the second lumbar vertebra. At its commencement it is suspended from the liver by The duodenum is composed of four portions. The first portioti (superior; begins at the pylorus and ends at the neck of the gall-bladder. It is about 5 cm. (2 in. ) long, and runs backward along the body of the first lumbar vertebra. The second portio7i (descending) is about 10 cm. (4 in.) long, and runs down the right side of the bodies of the lumbar vertebrae to the lower border of the third. The third portio7i (variously called ascending, transverse, or inferior) runs diagonally upward across the body of the third lumbar vertebra to its left side and then the fourth portion ascends to the left side of the second, where it takes a sharp turn and is continued as the jejunum (Fig. 419). Relations. — First portion: Above and in front are the quadrate lobe of the liver and the gall-bladder; below is the pancreas; and behind, from left to right, lie the gastroduodenal artery, the portal vein, the common bile-duct, and the vena cava. Second portion : lii front is the liver, the neck of the gall-bladder, and the transverse colon. Behind are" the renal vessels, ureter, right kidney, and psoas muscle. To its inner side lie the pancreas and vena cava. The common bile-duct runs on the inner side between the duodenum and the pancreas; at the middle of this portion of the duodenum the bile-duct joins with the pancreatic duct to empty into the duodenum through the ampulla of Vater, about 10 cm, (4 in.) from the pylorus. Third portion: In front are the superior mesenteric artery and root of the mesentery; behind He the vena cava, aorta, and left psoas muscle. Above, it lies in contact with the pancreas. The termination of the duodenum is usually on the left of the aorta, but Dwight (Journal of Anatomy and Physiology, vol. xxxi, p. 576) in fifty-four cases found it twenty-six times on the right of the aorta until just before its terminal flexure. It was wholly on the right side six times, in front of the aorta ele\'en times, and had crossed the aorta eleven times. Peritoneal Covering. — ^First part: The pyloric half is almost completely covered by peritoneum, but the distal half only on its anterior surface. Second part: No peritoneum on its inner and posterior surfaces, and only on its outer and anterior where not covered by the transverse colon. Third and fourth parts: The anterior and left sides are covered by peritoneum except where crossed by the root of the mesentery and superior mesentric \'essels. JEJUNUM AND ILEUM. The jejunum is about 83^ ft. long and the ileum about 12^ ft. They are bound to the spinal column by the mesentery, which extends from the left side of the body of the second lumbar A-ertebra to the right sacro-iliac joint. jejunal fie xnre. The beginning of the jejunum passes downward, forward, and usually toward the left. If the transverse colon is thrown upward and the jejunum is pulled sharply to the right, a folded edge of peritoneum containing some muscular fibres is seen passing from the flexure to the parietal peritoneum. This is called the siispensojy ligament or mnscle of Treitz. The fossa which is behind it is the superior duodenojejunal fossa of Treitz while that below is the ijferior duodenal fossa. Below the fossa runs the inferior mesenteric artery and near the left edge of the ligament runs the inferior mesenteric vein. Into the fossae, if abnormally large, the intestines may enter and produce a retroperitoneal hernia. If the constricting band, which is the ligament of Treitz, is cut, there is danger of di\iding the inferior mesenteric vein (see Fig. 420). The walls of the jejunum are thicker, redder, and more vascular than those of the ileum and the valvulse conniventes are better developed. The ileum is thinner, narrower, paler and, particularly when diseased, the large Peyer's patches can be seen. abdomen. The ileum is more in the right lower quadrant of the abdomen. According to Treves, the intestine from six to eleven feet from its commencement has the longest mesentery and is apt to be found in the pelvis. The lower end of the ileum is also usually found in the pelvis, and rises over its brim to join the caecum. There is no certainty, however, of finding a definite piece of the small intestine under any special point on the surface, because the varying distention and movements cause frequent changes of position. Meckel's Diverticulum. — In the embryo the vitello-intestinal duct passes from the umbilicus to the lower end of the small intestine. Normally this disappears, but sometimes a portion of it remains and there is found, one to three feet above the ileocaecal valve, a finger-like projection from the side of the ileum, 5 to 7.5 cm. (2 to 3 in.) long. This is called Me eke V s diverticulum, and may become the site of disease the same as the Peyer's patches (noduli lymphatici aggregati) are most numerous in the lower portion of the ileum. They are ulcerated in typhoid cases and are frequently the site of perforations. These patches are from i to 2.5 cm. (}^ to i in.) wide and 2.5 to 7.5 cm. ( I to 3 in. ) long. When affected in typhoid ^^^-''-'-^^^luthS'^Jk^chl""'' ^^^"^ fever they can readily be seen through the intestinal valvulae conniventes can readily be seen. The perforations in typhoid fever occur usually within three feet of the ileocaecal valve, though occasionally they may occur, as we have seen, in the appendix, or higher up in the small intestine, or even in the large intestine. to on page 406. On opening the abdomen, if it is desired to find the upper end of the small intestine, the omentum is pulled out, drawing with it on its under surface the transverse colon. The hand is to be passed backward on the under surface of the transverse mesocolon until the spine is reached; on its left side will be felt the duodenojejunal flexure. On drawing the jejunum to the right, the ligament of Treitz will be seen. A loop 40 cm. (16 in. ) down may be taken and brought up in front of the omentum and used for an anterior gastro-enterostomy, or the intestine immediately below the flexure may be used for a posterior gastro-enterostomy (see page 406). If one desires to find the lower end of the small intestine, then a search is made for the colon in the right iliac region. It is recognized by its longitudinal bands and is followed down to the ileocaecal junction. If the case is one of typhoid fever, a rapid examination is then made from the ileocaecal valve upward for perforations. It is desirable at times to determine which is the proximal and which the distal end of an intestinal loop. The best way to do so is to follow the loop down to the mesenteric attachment, as advised by Monks ; if the mesentery proceeds up and to the left you have the proximal end; if, however, it is passing down to the right you have the distal end. The intestine receives its nourishment from the mesentery and will die when detached, hence it is necessary to avoid injury or detachment of the mesentery or its vessels ; when this detachment has occurred the involved portion of intestine is resected and removed. Root of mesentery The mesentery extends from the left side of the body of the second himbar vertebra to the right sacro-iHac joint. It is from 15 to 20 cm. (6 to 8 in. ) long at its root and spreads out like a fan, to be attached to the small intestine. It is comparatively thick, especially toward its root, and contains the superior mesenteric artery and veins, nerves, and lymphatics. The mesenteric lymphatic nodes are numerous, from 130 to 150 (Quain) in number. They are frequently involved in carcinoma and tuberculosis, and may form masses which may be mistaken either for independent tumors or outgrowths from other organs. They are sometimes inflamed, and even cause abscess, being mistaken for appendix disease. They become calcareous and by the Rontgen rays may cast shadows which ha.yQ been mistaken for calculi of the urinary organs. The mesentery has its vessels sometimes ruptured by violence or blocked by emboli or thrombi. This is likely to cause gangrene of the intestine to which they are distributed. In abdominal operations the greatest care is to betaken not to ing from the left and lower quadrants tends to pass under the intestines toward the left iliac fossa. In searching the abdomen through a large median incision for the source of a concealed hemorrhage, the intestines are first to be pushed down and to the left, and the right side of the abdominal wall lifted with retractors. This will expose to view the upper surface of the small intestines, the ascending and transverse colon, the right kidney, liver, stomach, and head of the pancreas. Should additional search be necessary the small intestines are to be raised and turned upward and to the right (Fig. 422), being brought out of the wound if necessary. This will expose the under side of the small intestines and mesentery, the sigmoid flexure, descending colon, left kidney, spleen, and tail of the pancreas, with the left end of the stomach and left lobe of the li\'er above. The intestines are never to be turned downward to the right nor upward to the left. The mesentery attains its greatest length, according to Treves, from 6 to 1 1 feet below the duodenum, where it measures 25 cm. (10 in.) In hernia the mesentery is lengthened to allow of the descent of the gut. Rarely openings are present in the mesentery which may allow the entrance and strangulation of a coil of the intestine. Fig. 422. — ^The mesentery' is seen running downward toward the right sacro-iliac joint; the index finger is below it and the other three fingers above. The small intestines have been raised on the hand and turned upward thus exposing the pelvis and entire left lower half of the abdomen for examination. The large intestine comprises (i) the ccEciim and appendix, (2) ascending coloyi, (3) transverse colon, (4) desce^iding colon, (5) sigmoid fiexiire, composed of the ihac colon and pelvic colon, and (6) the rectum and anal canal. The length of the large intestine exclusive of the rectum and anal canal is 135 cm. (4 ft. 6 in.) in the female, and 140 cm, (4 ft. 8 in.) in the male. If the anterior abdominal wall is removed the csecum and part of the ascending colon are visible but in the upper part of the lumbar region the colon disappears, being overlaid by the small intestine. Having turned at the hepatic flexure, it again comes into view below the lower edge of the liver and passes superficially across the abdomen to disappear under the left costal margin to form the splenic flexure. It is not visible again until it reaches the region of the crest of the ilium, where it once more becomes superficial and follows the inguinal (Poupart's) ligament down to near its lower end, where it turns backward and upward to form the sigmoid loop which descends along the sacrum. In operating it is necessary to be able to distino-uish large from small intestine. Size. — The large intestine at its commencement at the caecum mav have a diameter of 7.5 cm. (3 in.), but it decreases in size, and, especially if empty, the descending colon and sigmoid flexure may only be 2. 5 cm. ( i in. ) in diameter. A distended part of the small intestine will be larger than a contracted part of the colon. Inasmuch as operations are frequently done for obstructive conditions which greatly enlarge the involved parts, it is unreliable to depend on size as distino-uishinothe large intestine. There are three longitudinal bands {teenies coli) on the colon from 6 to 12 mm. (^ to ^ in. ) wide, according to the amount of distention. One is anterior, another postero-external, and the third postero-internal. On the transverse colon they ha\'e the same relative position when the great omentum and colon are raised and turned upward. They all begin at the appendix and tra\'erse the large intestine until the rectum is reached, where they blend together, formino- a longitudinal layer which is v/eak at the sides and strong anteriorly and posteriorly. Sacculation of the colon is produced by the longitudinal' bands being onesixth shorter than the rest of the tube. While sacculation tends to becorne less marked on distension, it is still a valuable means of identification. Dividino- the longitudinal bands will cause the sacculation to disappear and the gut to leno-then. Appendices epiploicse or the small tags of peritoneum containing fat, are found along the large intestine as far as the rectum. They are most numerous alonothe inner longitudinal band and the transverse colon. The csecum is the blind pouch of the large intestine which extends bevond the opening of the ileum. It is about 7.5 cm. (3 in.) broad and 6.25 cm. (2^4 in.) long. Its three longitudinal bands converge to the appendix and are continued over it. It lies in the right iliac fossa on the iliacus and psoas muscles, more on the latter, and reaches nearly or quite to its inner edge. It is in contact Avith the abdominal wall above the outer half of the inguinal (Poupart's) ligament. In fetal life the caecum is cone-shaped and passes gradually and regularly into the appendix. It increases in size more rapidly on its outer side, so that the appendix, which was before opposite the long axis of the gut, becomes placed to the inside just below the ileocaecal valve. Four varieties of csecum are given by Treves: (i) the conical or fetal type, (2) a globular or quadrilateral type, in which the de\'elopment of both sides is even, (3) the adult type, in which the outer side is much larger than the inner, (4) an irregular type, in which there is an excess of development of the outer side and an atrophy of the inner side resulting in placing the root of the appendix close to the lower and posterior portion of the ileocecal junction. The ileocaecal valve marks the emptying of the ileum into the large intestine. On the surface of the body it corresponds to a point 2.5 cm. (i in.) below the middle of a line joining the anterior superior spine and the umbilicus and the same distance above the middle of a transverse line drawn from the anterior superior spine to the median line. This point is about on the linea semilunaris and directly above the point where the external iliac artery passes under Poupart's ligament. Normally the ileocaecal vah-e will allow of the passage of gas from the colon into the ileum, as in Senn's hvdrogen test for perforation, but not of liquids or solids. much, both in length and diameter. In health its average length may be given as from 8.75 cm. (t,}4 in.) to 10 cm. (4 in. ) and its diameter as 6 mm. (^ in.). It is pale in color and soft in consistence, with its blood-vessels barely visible. In disease it becomes hard and red and the injected vessels are distinctly seen. It becomes much increased in diameter, equalling in size a finger or thumb, and lengthens to 15 cm. (6 in.) or even more. It possesses a serous peritoneal coat, a longitudinal muscular, a circular muscular, a submucous and a mucous coat. The lumen of the appendix has been found to be partially occluded in at least one-fourth of all adults. This occlusion occurring toward its distal extremity is not regarded as pathological, but constrictions occurring elsewhere in the length of the tube are probably the result of previous disease. The opening of the appendix in the caecum is about 2.5 cm. (i in.) below and a little behind the ileocaecal opening. The fold of mucous membrane guarding it has been named the va/ve of Gcrlach but it is not generally regarded as a distinct valve. The root of the appendix is only about 2 cm. (3^ in. ) below the lower edge of the ileum and is often even closer on account of the lower surface of the ilium being in contact with the caecum at that point. It corresponds to a point on the surface of the body where the right semilunar line crosses a line joining the two anterior superior spines (Fig. 423). The meso-appendix (mesenteriolum) comes of? the lower surface of the mesentery. It is shorter than the appendix, hence the twisting and curling of the latter. It usually, but not always, extends to the tip and contains toward its left or free border the appendicular arterv. The ileocolic artery, from the superior mesenteric, as it approaches the ileocaecal junction divides into five branches: (i) the colic, distributed to the colon; (2) the ileal, to the upper surface of the ileum; (3) the an fe?'io?' ileoccecal branch, to the front of the caecum, passing through the ileocolic fold;' (4) ihe posterior ileocecal artery, to the posterior part of the caecum; (5) the appendicular artety. The appendicular artery descends behind the ileum to enter the meso-appendix and, after sending one recurrent branch to the root of the appendix and another to the ileocaecal fold, passes along the left or free edge of the meso-appendix, and, if this is short, it may be continued on the surface of the appendix to its extremity (Fig. 424). Fig. 423. — The relations of the appendix. The ileoca-cal junction is seen to be about one inch below the middle of a line joining the anterior superior spine and umbilicus or where this line crosses the linea semilunaris. The base of the appendix is under the point of crossing of the linea semilunaris and the middle of a horizontal line running from the anterior superior spine to the mid-line of the body; it is one inch below the ileocaecal junction. The veins of the appendix and the caecum end in the ileocolic vein, which joins the superior mesenteric vein and helps to form the portal vein. Hence infection is carried by the blood stream from the appendix and caecum directly to the liver. Position of the Appendix. — The position and direction of the appendix have been variously described and much discussed. This has arisen from the fact that it is so curled, curved, and twisted on itself that it is impossible to say that it points in any definite direction, and that, being so mobile, it may be found in almost any position, swinging around with its point of attachment to the caecum as the axis. We agree with Cunningham when he says that it runs generally in one of three directions: (i) over the brim into (or towards) the pelvis; (2) upward behind the caecum; (3) upward and inward toward the spleen. As he says, each of these has been considered the normal position by one or more observers. It is evident that, as the appendix comes off close to the ileum, this is its most fixed and constant point. In certain cases the caecum retains its high fetal position and then the appendix will be higher than usual. If the appendix is long and straight, its tip may reach to or beyond the median line; it may lie in contact with the rectum, ovary, tube, or bladder; it may lie low down close to Poupart's ligament or curved upward behind the colon, reaching in front of the kidney and nearly or quite to the liver. When retrocaecal it lies on the quadratus lumborum; when lower it may lie on the iliacus or psoas muscle. If it goes over the brim of the pelvis it lies on the external iliac artery. The external iliac vein is below and to the inner side and is largely protected from injury in operating by the stronger and tougher artery. the peritoneum in the neighborhood of the caecum. I. The superior ileocecal {ileocolic) fold runs from the upper surface of the mesentery jusc above the ileum to the upper anterior surface of the caecum. In it runs the ileoc(Scal {anteiior) artery. Beneath it, with its opening toward the left, is the superior ileoccBcal fossa (Fig. 424). 2. The inferior ileoc(Zcal fold passes from the termination of the ileum to the front of the meso-appendix ; it contains a small recurrent branch of the appendicular artery. Beneath it and between it and the meso-appendix is the inferior ileocecal fossa, which may sometimes contain the appendix. 3. The reirocolic fold is not constant and may be multiple. It passes from the lower and outer surface of the caecum to the peritoneum beneath. It binds down the end of the caecum and not infrequently must be divided before the caecum and appendix can be raised; the fossae on each side of it are called the retrocolic fossa;. Lymphatics of the Caecum and Appendix. — The lymphatics of the Ccscum and appendix drain into a group located in the mesentery of the ileocaecal angle, accompanying the ileocolic artery. According to Poirier and Cuneo there are three sets: an anterior caecal, a posterior caecal, and an appendicular. after traversing three to six small nodes, empty likewise into the ileocaecal group. The appendicular lymphatics form four or five trunks which accompany the artery between the layers of the meso-appendix. They then pass across the posterior surface of the ileum to empty into the ileocaecal group. Poirier and Cunto state that these lymph-trunks from the appendix pass through one to three nodes placed in the retro-ileal portion of the meso-appendix, but Kelly and Hurdon state that in the majority of cases these trunks empty into one or two nodes some distance above the ileum in the ileocaecal angle, forming a part of the ileocaecal chain. These latter authors state that there are three sets of lymphcapillaries in the appendix : a superficial or subperitoneal set, another between the submucous and muscular layers, and a deep set in the mucosa around the glands of Lieberkuhn. The three great lymph-streams, anterior caecal, posterior caecal, and appendicular, are quite distinct from each other and from the surrounding lymphatics of the pelvis and colon; when these latter are involved it is not by a lateral extension from these three streams but by direct infection from the regions which they themselves drain. From the ileocaecal nodes the lymphatics follow the arteries to the nodes at the root of the mesentery and empty into the receptaculum chyli. They do not follow the veins to the liver, hence infection of the li\'er is not caused through the Ivmph-channels in appendicitis. Appendicitis. — Diagnosis. — The most fixed part of the appendix is its root. This corresponds to a point on the linea semilunaris opposite to the anterior superior spine of the ilium. The painful tip of the appendix may be anywhere in a circle around this point 10 cm. (4 in.) in radius. It may be lying posterior and simulate calculus or other kidney trouble; it may be up toward the liver or gall-bladder; it may be toward the left, even beyond the midline; it may be in Douglas's cul-de-sac ancl be confounded with disease of the uterus, tubes, and bladder. It overlies the ureter and may be mistaken for calculus therein. An enlarged gall-bladder can ha\'e its painful apex at McBurney's point. Typhoid ulcers occur close to and, as we have observed, may involve the appendix. All these relations must be remembered. McBurney placed the most tender point 4 to 5 cm. ( i ^ to 2 in. ) from the anterior superior spine in a direction toward the umbilicus. Personally we would place it near the root of the appendix at least 2.5 cm. ( i in.) lower down and a little farther in. Operation. — An incision for appendicitis often used is a longitudinal one over the edge of the rectus muscle, either going directly through it or drawing it to one side (Fig. 425). In McBurney's operation the external oblique is split in the direction of its fibres and the internal oblique and transversalis are parted upward and inward in the direction of their fibres, thus making a square hole through which the appendix is removed. The writer {Annals of Surgery, Jan. 1906, p. 106) uses a transverse incision with its centre over the linea semilunaris opposite to or 2.5 cm. (i in.) above the anterior superior spine. The sheath of the rectus is di\'ided transversely and the muscle displaced toward the median line. The outer portion of the incision As soon as the peritoneum is opened the omentum may present itself. This is to be displaced to the left. Some coils of small intestine if present are to be pushed also to the left. The intestine then presenting will be the colon or caecum, because rectus Fig. 42s. — Incisions used for operations on the appendix. The longitudinal operation passes through and separates the fibres of the rectus muscle. The oblique operation (that of McBurney) separates the external oblique, internal oblique, and transversalis muscles in the direction of their fibres. it is fastened to the posterior wall and cannot be moved away. The longitudinal bands will also identify it. Another way is to pass the finger down the inside of the abdominal wall and the floor of the iliac fossa and bring up the caecum. Always work from the outer toward the inner side, because (see Fig. 422) the ascending The caecum is to be drawn up and turned toward the head. The longitudinal bands, all of which lead to the appendix, are to be followed down over the caecum until the appendix is reached. If the bands are not visible, identify the ileocaecal junction and about 2 cm. ( 34; in. ) or less below and behind it will be the root of the appendix; its tip may be anywhere. It can be enucleated from its root out to its tip. A lio-ature is to be placed around the meso-appendix because the appendicular artery, especially its recurrent branch, may bleed quite freely. The root of the appendix may sometimes be at, instead of below, the ileocsecal junction. The small intestine and caecum almost always overlie the appendix. THE COLON. The ascending colon lies in contact with the anterior abdominal wall from its lower end to above the iliac crest ; here it dips down to lie on the kidney and form the hepatic flexure above (Fig, 427). At this point some of the coils of the small intestine may lie in front of the hepatic flexure, between the beginning of the transverse colon above and the ending of the ascending colon below^ The ascend- the transverse colon turned upward. The pelvic colon and iliac colon together form the sigmoid flexure. ing colon lies on the quadratus lumborum muscle and kidney behind and has the psoas to its inner side. It has no mesentery or peritoneum on its posterior surface in 64 per cent, of the cases (Treves) and in tumors of the kidney it may be pushed forward and across their anterior surface. This is a point to be remembered in diagnosis. The transverse colon passes diagonally up and to the left across the abdomen. It starts at the hepatic flexure on the under surface of the liver to the outer side of the gall-bladder. It runs parallel with the lower edge of the liver and stomach and its lower border may reach nearly or quite to the level of the umbilicus. The great omentum passes ovei the transverse colon, so that to see the latter it is necessary to raise the omentum and look on its under surface. The omentum as it passes from the colon to the stomach forms the gastrocoHc omentum and the two organs may be either close together or some distance apart. The transverse colon instead of running upward and to the left may form a large cur\^e downward, reaching almost to the pelvis. In cases of dilatation and descent ''ptosis j of the stomach the transverse colon descends with it. The transverse mesocolon passes backward and one layer goes up and covers the pancreas while the other goes down to the mesenter}'. Its importance in gastro-enterostomy has been pointed out (page 406). Tumors and cysts of the pancreas may push fonvard abo\e it, or below it, or it mav cross directly o\-er the surface of the growth. The descending colon at its commencement at the splenic flexure is much higher and more deeply situated than is the hepatic flexure. It follows the stomach upward and backward and lies against the spleen. From here it descends and is entirely covered by small intestine, the sigmoid flexure coming to the front in the left iliac fossa. The descending colon is much smaller in size than the ascendine colon, and like it m the majority Ttwo-thirdsJ of cases has no mesentery-. In doing a colostomy through the loin, the external border of the quadratus lumborum muscle is the guide to the descending colon. It lies 1.25 cm. (J^ in.) behind the middle of the crest of the ilium. or omega loop of Treves. The iliac colon is about 12.5 to 15 cm. (5 to 6 in.) long, and runs from the crest of the ilium to the inner edge of the iHopsoas muscle. It has no mesenters* in 90 per cent, of the cases TJonnesco), and usually comes into contact with the abdominal wall to the inner side of the anterior superior spine sometimes as far down as the middle of Poupart's ligament. In doing an inguinal colostomy this is the portion of the colon it is desired to find. It is then followed down until a part is reached which has sufficient mesentery^ to allow of its being drawn out of the wound. The pelvic colon is about 40 to 42.5 cm. ^16 to 17 in. ) long and runs from the edge of the psoas muscle to the level of the third sacral vertebra. It makes a large horseshoe-shaped loop, from which it was named bv Treves the omega loop, and has a mesenter}^ from 3 to 8 cm. {\}i to 3^ in.) long. The length of the loop as well as its mesenter}^ and its position all vary considerably. Its terminal portion usually -runs longitudinally down to end in the rectum, but its intervening portion mav pass over the bladder to the right side, or high above the svmphvsis, or even extend well up in the abdominal canity. On the under or left side of the loop between its branches is the inter sigmoid fossa (see Fig. 422, page 410) ; sometimes it forms a constricted pouch in which a knuckle of intestine has been known to become strangulated. THE LIVER. The liver is wedge-shaped and has three surfaces. These are superior, inferior, and posterior. The posterior forms the base of the wedge and its anterior edge is the apex. The liver is di^^ded into five lobes by five primar}- fissures and has five ligaments (Fig. 428). The lobes of the liver are: (i) left, (2) right, (3) quadrate, (4) Spigelian, (5) caudate. The left lobe is one-sixth the size of the right. It comprises that part to the left of the falciform ligament abo\'e and the umbilical and ductus venosus fissures below. The right lobe comprises that part to the right of the falciform ligament above and the fissures of the gall-bladder and A-ena ca^-a below. The quadrate lobe is the anterior, small, square-shaped lobe betn'een the fissure of the gall-bladder on the right and the umbilical fissure on the left. It extends from the anterior edge back to the portal fissure. The Spigelian lobe is best seen posteriorly, extending from the vena cava on the right to the fissure of the ductus venosus on the left. The caudate lobe or process is the name given to the liver tissue running from the lower end of the Spigelian lobe to the right lobe. It passes behind the portal fissure and between it and the vena ca\-a. RiedeV s lobe is the name gd\en to an abnormal, tongue-like projection of liver tissue from its anterior edge, which may extend downward either over the eall-bladder or external to it. Mavo Robson has seen it extend to the caecal reeion and an inflamed gall-bladder being directly beneath caused pain to be experienced 'at McBurney's point. This condition is liable to be mistaken for appendicitis. The fissures of the liver are best understood by examining its under surface, where they can be seen arranged in the form of the letter H. They are as follows: ( i ) The wnbilical fissure, running from the umbilical notch on the anterior edge to the left end of the portal (transverse) fissure; it contains the round ligament. (2) Th^ fissure of the ductus venosi/s, running upward from the left end of the portal fissure between the left and Spigelian lobes; it contains the remains of the fetal ductus venosus. (3) The fissjcre of the gall-bladder, separating the quadrate from the right lobe and ending at the right extremity of the portal fissure; in it lies the gall-bladder. (4) T\\e fissure of the vena cava, between the Spigelian and right lobes, lodging the vena cava. (5) T\ve portal fissure, — this forms the transverse bar of the H. Its left end receives the umbilical and ductus venosus fissures and its right end the fissures of the gall-bladder and vena cava. It contains the portal vein, hepatic artery, hepatic diict, nerves and lymphatics; attached to its sides is the lesser or gastrohepatic omentum. The portal fissure is also called the transverse fissure, and the name lojigitudinal fissure is sometimes applied to the combined umbilical and ductus venosus fissures. (In the recent anatomical nomenclature these fissures are called fossae.) (Fig. 429.) The ligaments of the liver are five in number: (i) the coronary, (2) the triangular, (3) the falciform, (4) the round, and (5) the ligament of the ductus venosus. The coronary ligament surrounds the posterior surface which is not covered by peritoneum. It is 4 to 6 cm. (i>^ to 2>4 in.) wide and extends from the vena cava 7.5 to 10 cm. (3 to 4 in.) to the right, terminating in a pointed end which has been called the right lateral ligament. The triangjilar ligament, also called the left lateral, extends as far to the left of the falciform ligament as the coronary does to the right. It is attached to the diaphragm in front of the oesophagus, while the coronary is attached to the back of the diaphragm. The falciform ligament starts near the umbilicus, passes to the umbiHcal notch of the liver 2.5 to 4 cm. (i to I y^ in. ) to the right of the median line and thence over the top of the liver to near its posterior edge, where it blends in front of the vena cava on the right side with the coronary ligament and on the left with the triangular ligament. The roicnd ligament is the round cord in the free edge of the falciform ligament which runs from the umbilicus to the umbilical notch and thence to the portal fissure to join the left branch of the portal vein. It is the remains of the fetal umbilical vein. The ligament of the ductus venosus runs from the left branch of the portal vein to the vena cava in the fissure of the ductus venosus. The ductus venosus, like the umbilical vein, becomes obliterated at birth. Position of the Liver.— The liver rises to the fourth costal interspace on the right side, to or slightly above the xiphosternal juncdon in the midline, and the lower border of the fifth rib on the left side, to its extremity, just beyond the apex of the heart, at the lower border of the sixth rib. Its lower border passes from this point to the eighth left cartilage, crosses the middle line about midway between the xiphoid articulation and umbilicus to the ninth right costal cartilage, and thence follows the edge of the ribs posteriorly, being about 2.5 cm. (i in.) lower in women. The upper limits of its percussion dulness are the upper border of the sixth rib in the right mammillary line, the eighth in the axillary, and the tenth in the scapular. Relations of the Liver. — The superior surface lies in contact with the diaphragm, except the portion extending about 7.5 cm. (3 in.) below the xiphosternal junction in the median line and sometimes the small projecting edge beyond the ribs, which lies in contact with the abdominal wall. The postei'-ior surface lies over the tenth and eleventh thoracic vertebrae, the crura of the diaphragm, the oesophagus, aorta, vena cava, and right suprarenal gland. The inferior surface to the left rests on the cardiac end and upper surface of the stomach and gastrohepatic omentum. Beneath the quadrate lobe is the pylorus and beginning of the duodenum. Beneath the caudate lobe is the foramen of IVinslozc, of which it forms the upper boundary. Farther to the right are the depressions for the hepatic flexure of the colon and the right kidney and suprarenal gland (Fig. 430). The size of the liver varies, being small in atrophic diseases and much enlarged in others; therefore, alterations in the area of dulness are frequent. It moves with respiration and sometimes hangs lower than normal (ptosis). Wounds and Injuries of the Liver. — The liver is frequently ruptured in falling- or by being struck by some body from without. The rupture may involve its anterior edge or upper surface. In all examinations it should not be forgotten that the right and left sides are separated completely by the falciform ligament. On account of the walls of the vessels being imbedded in the liver tissue they do not readily collapse and hemorrhage is often fatal. Rupture of the posterior nonperitoneal surface is not so dangerous as elsewhere. Abscesses may be either one or two large ones or multiple small ones. Pus on the upper surface of the liver, between it and the diaphragm, is called subdiaphragmatic abscess. It may originate either from the liver or other viscera below, or the lung and pleura above. Maydl gives gastric ulcer as the most frequent cause and then affections of the intestines and appendix ; we have seen it arise from calculous disease of the kidney. The pus may discharge outward between the ribs, or upward into the pleural cavity, lung, or pericardial sac. In incising for subdiaphragmatic abscess the tenth rib in the axillary line can be resected without opening the pleura, but if the eighth or ninth is chosen the pleural sac may be opened and the two layers of pleura should be stitched together before the incision through the diaphragm into the abscess cavity is made. If the abscess points at the inferior surface it may break into the stomach, duodenum, or colon. It may be reached by an incision through the abdominal walls to the right of the median line. The position of the falciform ligament, about 4 cm. ( i ^ in. ) to the right of the median line, should be remembered, and if the left lobe of the liver is to be treated the incision should be made to the left of the ligament. Multiple abscesses are started in the liver by conveyance of infection through the portal vein, as occurs in appendicitis, or by direct extension up the common duct from the intestine, or from an inflamed gall-bladder or bile-ducts through the hepatic duct and its ramifications. Portal Obstruction. — The veins of the portal system have no valves. The portal vein is formed by the union of the splenic and superior mesenteric veins and the gastric, pyloric, and cystic veins. The splenic receives the blood from the spleen, the stomach, and pancreas, the descending colon, sigmoid flexure, and rectum. The superior hemorrhoidal vein drains the rectum and empties into the inferior mesenteric, which passes into the splenic and finally into the portal vein. The superior mesenteric vein drains the remainder of the large and small intestine. In cirrhosis, carcinoma, and occasionally gall-stones, the flow of blood through the portal \'ein is interfered with ; hence arise congestions of the various parts which it drains. In the abdomen ascites is produced ; the distended and varicose veins of the stomach sometimes rupture, causing hcematemesis ; cliarrhcea may occur, and dilatation of the hemorrhoidal veins produces hemorrhoids. Especially when there also is pressure on the vena cava the superficial and deep veins of the abdominal wall become enlarged (see page 380). The main anastomoses are : ( i ) between the gastric (coronary) vein of the stomach and the oesophageal veins which empty into the vena azygos major; (2) between the epigastrics (superficial and deep) below and the terminal branch of the internal mammary above; (3) between the epigastric veins and portal vein through the para-umbilical vein (caput medusae, page 380); (4) through the thoracico-epigastrica between the axillary and epigastric (see Fig. 392, page 380) ; (5) between the superior hemorrhoidal and the middle hemorrhoidal, emptying into the internal pudic. The gall-bladder lies in the fissure of the gall-bladder, with its fundus just about level with the edge of the liver and its body pointing inward, upward, and backward; its neck, which is S-shaped, is near the right end of the portal fissure. It is 7.5 cm. (3 in.) long and 2.5 to 3 cm. (\ to \y^ in.) in diameter. It holds one to one and a half ounces. Below, it rests on the transverse colon and first part of the duodenum. It is attached to the liver, but not very strongly, by connective tissue and the peritoneum. According to Brcw^er { Annals of Surgery, 1899, vol. xxix, page 723) one-third to one-fourth of its surface is uncovered by peritoneum : in 5 cases in 100 it had a distinct mesentery. Tlie tip (fundus) of the gall-bladder lies in contact with the abdominal wall at the tip of the ninth costal cartilage, where the right Imea semilunaris strikes the costal margin, and just at the outer edge of the rectus muscle, which is about 7-5 cm. (3 in.) from the median Une (Fig. 431). Hepatic, Cystic, and Common Ducts. — The hepatic duct is formed by the union of the right and left branches in the portal fissure. It is about 2.5 cm. (i in.) lono- and 6 mm. (^yi in. ) wide. The cystic dtict is smaller in diameter than the hepatic and'3 to 4 cm. (1% to ij^ in.) long and joins it as it emerges from the portal fissure. Both the neck of the gall-bladder and the cystic duct contain constrictions of the mucous membrane — Robson and Moynihan call them valves — which obstruct the passage of a probe or stone. Hence gall-stones are frequently found impacted or lodo-ed in the neck of the gall-bladder or somewhere in the course of the duct. The cystic artery lies above the duct. The common duct is formed by the union of the hepatic and cystic ducts at the edge of the portal fissure, and empties into the duodenum about the middle of its second portion on its inner wall. It is 7.5 cm. (3 in.) lono- and 6 mm. (^ in.) or more in width. It passes almost directly downward. inclining a little to the right, between the folds of the lesser omentum, in front of the foramen of Winslow, behind the first portion of the duodenum, and then between the pancreas and the inner wall of the second portion of the duodenum. It is, at this part, in two-thirds of the cases, completely surrounded by pancreatic tissue. As it passes through the duodenum, which it pierces obliquely, it expands into the ampulla of Vater and receives the pancreatic duct, or duct of Wirsung. Abo\'e, it lies directly on the portal vein, with the hepatic artery to its left. About half of the duct, 3 to 4 cm. (i i^ to i^ in.), is above the duodenum and half behind it. The hepatic artery passes along the upper edge of the pancreas, to which it gives branches; it then gives off the superior pyloric to the lesser curvature of the stomach, the gastroduodenal (see page 403), and finally right and left terminal branches. The left supplies the left lobe of the liver, the right crosses usually behind but sometimes in front of the bile-ducts and terminates in the right lobe, after first giving off the cystic artery. This runs between the cystic and hepatic ducts and has superficial branches which ramify on the surface of the gall-bladder and deep branches which run up the grooves on each side between the , gall-bladder and liver. It is these branches which bleed when the gall-bladder is removed. One of the deep arteries may be much larger than the other or altogether lacking. Some very fine branches come directly from the li\'er. The kidney pouch is a name given to the space in front of the right kidney. The foramen of Winslow opens into it from the left and the abdominal wall is to its right. The liver is above and the duodenum and transverse colon below. _ Liquids from the lesser peritoneal cavity and bile-passages flow into this hollow, which can be drained by a tube inserted through a "stab-wound" made through the abdominal wall just to the outside of the right kidney. Gall-Stones. — These and carcinoma are the main affections of the biliary passages. The latter is almost always secondary to pyloric cancer and invokes the lymphatic nodes; metastatic deposits may also exist in the liver itself. The diagnosis between the two aflections is sometimes difiticult. Gall-stones are most frequent in the gall-bladder, next in the common duct, and lastly in the hepatic duct. Obstructive symptoms are not often observed from gall-stones in the hepatic duct alone. Obstruction of the common duct causes jaundice, but this is rare in obstruction of the cystic duct ; practically, jaundice is only seen in obstruction of the common duct. Gall-stones usually form in the gall-bladder and, as the cystic duct is smaller than the common duct, if a stone gets out of the former it is frequently passed into the intestine. On account of the contracted opening of the common duct into the duodenum, stones are liable to be retained in the ampulla of \'ater. This causes a damming back of the bile, and the common duct increases to the size of a finger. \'ery large gallstones may cause ulceration into the duodenum or colon or may press on the portal vein and vena cava, and produce ascites. In operating for gall-stones, Mayo Robson incised through the middle of the right rectus muscle and prolonged the upper part along the edge of the ribs to the outer side of the ensiform cartilage. Where more room was desired Be\-an added a transverse cut outward from its lower end. Kocher made a curved incision 4 cm. (i i< in.) below the edge of the ribs (see page 382). In order to make the liver project a hard roll is placed beneath the back. To bring the gall-ducts to the surface the liver is dragged down and its edge turned up over the upper extremity of the wound. The gall-bladder can be drawn out and this straightens the curves in the cystic duct. By placing one or two fingers in the foramen of Winslow the thumb can palpate the cystic and the common duct until it disappears behind the duodenum. Gall-stones in the second (retroduodenal) pordon of the duct or in the ampulla of Vater can often be felt through the walls of the duodenum. If it is desired to gain access to this portion of the duct, the peritoneum on the outer side of the second portion of the duodenum, binding it to the posterior abdominal wall, must be divided. The duodenum is then turned to the left and the common duct followed down if necessary through the pancreas to the ampulla of Vater. Stones impacted in the ampulla of Vater can be removed by incising the front of the second portion of the duodenum and then cutting down on the stone through the papilla. In some cases it may be impossible to pass a probe down the cystic duct owing to its being caught by the valve-like folds of the mucous membrane. In removing the gall-bladder, bleeding will be less if the cystic artery be first clamped. If this is not possible, then the bleeding will occur from the branches on one or both sides of the gall-bladder. The peritoneum is to be cut through, not torn. Bleeding from the liver substance is slight and readily stopped by pressure. In incising the common duct for calculi the relation of the portal vein behind and the hepatic artery to the left should be remembered. These can be avoided by cutting down on the calculus. The pancreas is composed of two portions joined at right angles to each other. Together they measure about 20 cm. (8 in.). It is divided into a head, neck, body, and tail. The neck is about 2 cm. (34 in.) broad, while the head and body are each about 3 cm. (i}( in.). The head is about 5 to 6.25 cm. (2 to 2}4 in.) long and lies parallel to the vertebral column on its right side. The body is about 12.5 cm. (5 in. ) long and runs transversely from the first portion of the duodenum across to the spleen. The flexure joining the head and body constitutes the neck. It is 2.5 cm. (i in.) long. The tail is simply the extremity of the body ; this is omitted in some descriptions. The body crosses the first lumbar vertebra, while the head lies on the right side of the second and third (Fig. 432). Pancreatic Ducts. — The pancreas has two ducts, a main one called the pancreatic duct, or duct of JVirsujig-, and an accessory one called the dicct of Santorini. The duct of Wirsung runs nearly the whole length of the gland, and, bending somewhat downward at the neck and joining the common bile-duct at the ampulla of Vater, pierces the duodenum obliquely and empties in a common orifice on its mucous surface. It is 3 to 4 mm. {yi \.o yi in.) in diameter at its termination. The accessory duct of Santorini comes mainly from the lower portion of the head of the pancreas and empties separately in the duodenum 2 cm. ( 3/^ in. ) above and a little anterior to the biliary papilla. It communicates with the duct of Wirsung in the substance of the pancreas. Relations. — Posteriorly, the head lies on the vena cava while the body crosses the aorta, renal vessels, suprarenal gland, and left kidney. Anteriorly, it is covered with peritoneum and on it lies the stomach ; inf eriorly , is the attachment of the transPortal vein verse mesocolon, beneath which comes the duodenojejunal flexure. Immediately to the right of this flexure and between it and the head of the pancreas issue the superior mesenteric vessels. At the extreme left is the splenic flexure of the colon. Pancreatic Cyst and Abscesses. — The pancreas is the subject of inflammation f hemorrhagic) which may cause necrosis and abscess; it also is affected with cysts and new growths. Calculus may also occur. Suppuration may produce a sub-diaphragmatic abscess or perforate the diaphragm and form an empyema. In cases of abscess protruding anteriorly, instead of opening through the peritoneum in front, the pus may be evacuated through a posterior incision made in the right or left costovertebral angle. If the pus has been evacuated through an anterior incision the finger may be introduced into the abscess cavity and used as a guide for a posterior incision. Pancreatic growths tend to project forward in one of three general directions — viz. : (i) between the liver above and the stomach below; (2) between the stom.ach above and the transverse colon below; (3) below the transverse colon. The second is the most frequent. When the enlargement comes forward opposite the attachment of the transverse mesocolon it may grow between the layers of the mesocolon and push the transverse colon in front of it instead of going below or above it. After the cyst has been evacuated it may be stitched to the edges of the incision anteriorly and a counter opening made posteriorly on the left side beneath the twelfth rib. THE SPLEEN. The spleen lies high up in the left posterior corner of the abdomen in contact with the diaphragm. It follows the direction of the tenth rib, being covered by the ninth, tenth, and eleventh ribs and extending from a point 4.5 to 5 cm. (i^ to 2 in.) external to the median line posteriorly to the midaxillary line anteriorly. Its upper end is opposite the tenth dorsal vertebra, or ninth spine (see Fig. 433). Relations. — -It has four surfaces: a posterior one, which lies in contact with the diaphragm; an anterior one toward the stomach; an inferior small one, resting on the splenic flexure of the colon; and an internal one, in contact with the left kidney at its upper anterior portion. The hilum is on its anterior or gastric surface and posterior to it is a depression in which is lodged the tail of the pancreas. Ligaments. — The spleen is covered with peritoneum except at the hilum, which is on its anterior surface ; here two ligaments are given of^ — a posterior one, the lieiiorenal, going from the spleen to the kidney and containing the blood-vessels, and an anterior one, t\\Q gastrosplenic (also called omentum) going to the stomach. The lienophrenic ligament ( suspensory ligament) runs from the left crus of the diaphragm to the upper inner edge of the spleen and blends with the two former ligaments. These three ligaments form a pedicle from which the spleen swings, and it is by their stretching that the spleen at times descends and is detected below the edge of the ribs. A fourth ligament, the phrenocolic (costocolic^ runs from the diaphragm opposite the tenth and eleventh ribs to the splenic flexure of the colon. The upper surface of the colon is concave, forming a fossa (splenic fossa) in which the spleen rests and which, of course, aids in supporting it. Splenic Enlargement. — The spleen is enlarged in many diseases, such as malaria, leukcemia, typhoid fever, and others. This enlargement is to be detected by palpation and percussion. The normal spleen lies under the ribs, therefore it can be palpated only when it enlarges and projects beyond the costal margin or when its pedicle (ligaments) becomes stretched and allows it to wander down. Normal percussion dulness extends anteriorly to the midaxillary line; posteriorly it merges into the kidney dulness and cannot be limited. From above down the dulness would be from the ninth to the ele\enth rib in the posterior axillary line. Wounds of the Spleen. — The upper portion of the spleen rises as high as the tenth dorsal vertebra or ninth spine ; as the lung posteriorly descends at least one vertebra lower and the pleura still another lower, it follows that a penetrating wound entering the ninth costal interspace in the line of the angle of the scapula would wound first the pleura, then the lung, then the diaphragm, then the spleen, and finally the stomach. If it entered one interspace below — the tenth— it would open the pleural cavity but would probably escape the edge of the lung. longer. They lie in the lumbar regions under the lower portion of the thoracic wall. Their upper ends are nearer the midline than the lower and the inner edges point forward and inward, thus one surface is antero-external and the other posterointernal. Relations to the Surface. — X'iewed posteriorly the right kidney has its upper edge opposite the eleventh dorsal spine and the lower edge of the ele\enth rib. Its lower edge is opposite the upper edges of the third lumbar spine and vertebral body and about 4 cm. (i^ in.) above the highest point of the crest of the ileum, which is opposite the fourth spine (Fig. 433). The left kidney is usually 1.25 cm. {y2 in. ) higher, but being a little longer than the right, its lower limit may not be quite that much higher. The kidney is slightly lower in women and children than in men. The inner border reaches 10 cm. (4 in.) and the hilum 4 to 5 cm. (1% to 2 in. ) from the median line, the latter being in front of the interval between the first and second lumbar spines (H. J. Stiles j. Viewed anteriorly, the lower edge of the right kidney is 2.5 cm, (i in.) above a transverse line through the umbilicus, the left being a little higher. The upper edge is opposite approximately the tip of the ensiform cartilage. The upper end approaches within 3 cm. (i}( in.) of the median line. About two-thirds of the kidney lies to the inner side and one-third to the outer of a line drawn longitudinally through the middle of Poupart' s ligament. The hilum would be 4 to 5 cm. (i}4 to 2 in. ) out from the middle of a line joining the upper extremities of the two semilunar lines. Deep Relations. — The posterior surface at its upper portion rests on the diaphragm; beneath, its lower portion, from within out, rests on the psoas, quadratus lumborum, and transversalis muscles. Between the kidney and the quadratus lumborum run the last thoracic, the iliohypogastric, and the ilio-inguinal nerves. The transversalis fascia as it leaves the body of the first lumbar \ertebra arches over the psoas muscle, forming the internal arcuate ligament, and is attached to the trans- verse process of the first lumbar vertebra. It then proceeds out over the quadratus lumborum to be attached to the outer portion of the twelfth rib, forming the external arcuate ligament. It then blends with the tendon or fascia, giving origin to the internal oblique and transversalis muscles. Between the fibres of the diaphragm which arise from the external arcuate ligament — over the quadratus lumborum muscle — and the fibres arising from the twelfth rib, a triangular space exists with its base downward. It is called the hiatus and if marked allows the pleura and the kidney to come in contact without any muscular fibres intervening. This favors the passage of pus from the region of the kidney into the pleural cavity and lung. The anterior surface relations differ on the two sides. On the right side above is the suprarenal gland, then a large area where it is in contact with the liver, then below to the inner side the descending or second part of the duodenum, and below and to the outer side the hepatic flexure of the colon. On the left side above and to the inner side is the left suprarenal gland. Beneath it is a small area for the stomach, and still lower a larger one for the left end of the pancreas. On the outer flexure of the colon and jejunum. The hilum is the name given to the notch in the inner edge of- the kidney. It contains the pe/vis and commencement of the ureter and the renal vessels and nerves. The sinus is the cavity of the kidney. The edges of the pelvis are attached to the borders, or rim, of the hilum. Renal Vessels. — The renal arteries come off opposite the first lumbar vertebra. The right one, a little the longer and higher, passes out beneath the vena cava, head of the pancreas, and second portion of the duodenum. The left one passes behind the pancreas. On reaching the kidney they break into three or four (sometimes more) branches. One of these branches usually proceeds down and enters the kidney on the lower posterior side of the pelvis. The other branches enter anteriorly. The renal vein on leaving the kidney is formed by several branches which pass either in front or posterior to the arterial branches. Greig Smith held ("Abdominal Surgery," vol. ii., p. 799) that the veins were posterior to the arteries. The jjelvis is posterior; hence in searching for stone if it is desired to open the pelvis of the kidney it should be incised posteriorly. The usually accepted order is, pelvis posterior, then the arteries, and lastly the veins most anterior (Fig. 434). The blood-vessels of the anterior portion pass out toward the cortex and on passing its middle encroach a little on the posterior side. For this reason incisions through the kidney substance are made on its convex border about i cm. (f in.) posterior to its middle (¥\g. 435). Renal Capsules. — There are two capsules of the kidney — a fibrous one and a fatty one. The fibrous capsule covers the outside of the kidney and is prolonged into the hilum and lines the sinus. It can be stripped from the kidney, but when the organ is diseased it brings small portions of the kidney substance with it. T\\q. fatty capsule surrounds the kidney, being more abundant around its edges and not so much on its anterior and posterior surfaces. The kidney lies comparatively loose in this fatty capsule, slipping backward and forward. The fatty capsule is continuous below with the subperitoneal fat. Perirenal Fascia of Gerota. — Covering the fatty capsule is the perirenal fascia, composed of two layers — anterior and posterior. The anterior is continuous with that of the opposite side over the vertebral column. It proceeds outward over the vessels, ureter, and kidney, and fatty capsule, blending at the outer and upper border with the posterior layer ; below, it fades away in the subperitoneal tissue of the iliac fossa. The posterior layer passes inward behind the kidney from its outer and upper borders, to be attached to the sides of the vertebral column. Above, these layers are attached to the diaphragm ; below, they are continuous with the subperitoneal tissue of the iliac fossa. There is also some perirenal fat behind the perirenal fascia, between it and the muscles beneath (Fig. 436). Incisions into the organ are to be made as indicated on the posterior surface just back of the prominent edge. by intra-abdominal pressure. Normally it cannot be felt beneath the edge of the ribs. It, however, readily becomes displaced and slides down so as. to be felt below the costal margin; it is then called a movable kidney. If the displacement becomes more marked it may descend into the iliac fossa or even toward the median line; then it is called -^floating or wandering kidney. In some instances it slides around without pushing the peritoneum markedly fonvard, hence it then has no mesentery or pedicle. In other cases it stretches the peritoneum in front of it and has sulificient of a mesentery to allow it to come in contact with the anterior abdominal wall. Tumors. — As the kidney enlarges it does so in a forward and downward direction. As it comes forward it may go to the outer side of the colon, to its inner side, or carry the colon directly in front of it. Greig Smith ("Abdominal Surger}-," p. 868) states that on the right side the ascending colon passes over the front and to the imier side of the growth, while on the left side the descending colon passes to the front and a little to the outer side. Renal tumors mav be mistaken for tumors of the liver and gall-bladder, spleen, and ovaries. A longitudinal coil of resonant intestine passing over the tumor is prima facie evidence of its being renal in character. Renal growths appear as more or less spherical tumors which can in some cases be palpated around their entire circumference. If one portion only can be felt, the remainder leads towards the loin ; in gall-bladder tumors (cysts) the base of the growth leads toward the liver and is in contact with the abdominal wall, overlying the colon and small intestine. In splenic tumors a notch can sometimes be felt and the growth makes its appearance from above, down under the left costal margin. Abscesses. — The kidney is frequently involved in suppurative affections. Calculi and tuberculous diseases are of that nature, and pyogenic infection may creep up from the bladder, producing pyelonephritis, or surgical kidney. The pus may be extrarenal, involving the adipose capsule and perirenal fascia ; it commonly points in the loin. As this fascia is open below and to the inner side the pus may descend to the iliac fossa or follow inside the sheath of the psoas muscle beneath Poupart's ligament. It may work its way up along the psoas under the ligamentum arcuatum internum and empty through the lung, or perforate the diaphragm at the hiatus and so reach the lung (page 425). We have seen it work along the under surface of the liver and point anteriorly at the costal margin. It may also rupture into the duodenum or colon. Sometimes it goes posteriorly and perforates the lumbar fascia to appear at the outer edge of the latissimus dorsi and erector spinae muscles in the iliocostal space, or at the triangle of Petit (page 394). Access to the kidney is demanded for fixing it in place when movable, for the removal of calculus, for the treatment of cystic conditions, abscesses, growths, and even for the entire removal of the organ, which sometimes is greatly enlarged. Incision. — Lumbar incisions have already been discussed (see page 395). There are three things to be borne in mind, viz. : the direction of the muscular fibres and position of the muscles, the position of the nerves, and, last, the pleura. This latter begins 2 cm. ( ^ in. ) below the last rib, at the edge of THE KIDXEYS. 429 the erector spina; muscle and passes downward and forward almost or quite parallel to the twelfth rib, toward the anterior extremity of the crest of the ilium. Mayo Robson {Lancet, May 14, 1898J made an incision from the inner edge of the anterior superior spine of the ilium to the tip of the last rib. The fibres of the external oblique were then split and retracted. Then the fibres of the internal oblique and transversalis were split, and retracted in the opposite direction. For this method it is claimed that no muscles, nerves, or vessels are divided, and the patient can be operated on while lying on the back. T Consult the Lumbar Muscles, page 392 ; Fascia, page 393; and Incisions, page 395). Nerves. — The nerves to be avoided in making lumbar incisions are the last thoracic, the iliohypogastric, and the ilio-inguinal. The last thoracic nerve, accompanied by the first lumbar artery, runs parallel to the last rib a short distance below — 1.25 cm. (J^ in.) — and thence pursues a direct course toward a midpoint between the umbilicus and top of the pubes. It emerges from beneath the external arcuate ligament about the middle of the kidney, crossing the quadratus lumborum, pierces the tendon of the transversalis muscle and runs between it and the internal oblique to pierce the sheath of the rectus and be distributed to the skin midway between the umbilicus and top of pubes and supply the pyramidalis muscle. This portion of the nerve will be injured only if the incision is carried up to the twelfth rib. When it is about opposite the tip of the eleventh rib it gives off a lateral (or iliac) branch which goes downward and slightly forward to pierce the internal and external oblique muscles above the crest of the ilium, about 5 cm. {2 in.) posterior to the anterior superior spine. This branch will be cut in making the incision, — but it is only a sensory nerve, not a motor. The iliohypogastric and ilio-inguinal nerves, from the first lumbar, come out together from beneath the psoas muscle opposite the lower third of the kidney, cross the quadratus lumborum, and pass downward and forward toward the crest of the ilium a little in front of its middle. The iliohypogastric is above the ilio-inguinal, and, piercing the transversalis muscle, divides into the hypogastric and iliac branches. The former pierces the external oblique 2.5 cm. (1 in.) above and a little to the outer side of the external inguinal ring. The latter goes over the crest of the ilium to the gluteal region. The ilio-inguinal pierces the transversalis and enters the inguinal canal to go to the genitals and anterior inner portion of the thigh. posterior and not visible. Pleura. — The pleura reaches the lower border of the posterior portion of the twelfth rib; it crosses the rib posterior to its middle, if the rib is of normal length, to pass to the eleventh rib. Therefore, to avoid the pleura the incision must not touch the twelfth rib posterior to its middle. One must not forget that the ribs are irregular in number and especially in length. It is necessary to identify the twelfth rib, this may be extremely difficult, and unless the greatest care is used a mistake is liable to occur. If the eleventh rib is mistaken for the twelfth the pleura comes so much farther forward that it is almost certain to be wounded, as has once occurred, producing a fatal result. The ribs may be counted down from the second at the angle of the sternum (Ludwig), remembering the possibility of there being, as we have seen, fourteen ribs on a side, or thirteen, or only eleven. The twelfth rib is frequently so short as to be completely concealed by the muscles; in that case only one floating rib would be seen. in contact with the pleura, and scrape off the periosteum from before backward. Delivering the Kidney. — After getting through the abdominal wall one comes down on the fat surrounding the kidney and its capsules. The kidney is to be felt inward and backward toward the spine. Ha\'ing been located by touch the perirenal fascia and the fatty capsule are to be opened and the kidney pushed and lifted into the wound. Do not go anterior, because there the colon or peritoneum may bulge forward. Once freed from its fatty capsule the normal-sized kidney is sufficiently movable to be lifted clear out of the wound onto the surface. If it is too large the wound must be enlarged downward. Incisions into the kidney substance should be made only when the organ is freely accessible, preferably when out on the surface, and in the manner described on page 426. The frequent existence of an additional artery supplying the lower (or other) portion of the kidney should be borne in mind. If it is desired to open the pelvis it should be sought on the posterior surface, because the veins and arteries are in front of it. The Suprarenal Glands. — The right gland is more on the upper anterior surface of the kidney, while the left is more on the upper inner surface above the hilum. The gland rests on the adipose capsule and is not attached to the kidney, so that when the fatty capsule is stripped off in removal of the kidney the suprarenal fland is left behind. They lie opposite the eleventh and twelfth dorsal vertebree and are 5 to 6 cm. (2 to 2^^ in.) apart. A needle thrust into the eleventh interspace close to the spine would penetrate the suprarenal. The right one lies behind the foramen of Winslow. Ureter, a7id Renal Pelvis. — The pelvis of the kidney is the upper expanded end of the ureter. It is not simply funnel-shaped, but it branches like a tree. The lower portion joining the ureter is called the common pelvis, and this divides into the superior and inferior pelves; these latter divide into eight or nine calyces which embrace the apices of the pyramids. The deposition of salts in the pelvis causes the formation of renal calculi, which are of the shape of the pelvis in which they occur. The arteries and veins which enter the kidney do so on the anterior surface of the pelvis; hence the incision for the removal of calculi which is sometimes made in the pelvis itself instead of through the Isidney substance, is made posteriorly instead of anteriorly. In making the incision care is to be taken to avoid any unusual veins or arteries which may cross the pelvis, especially at its lower portion. " Cunningham's Anatomy "). The left ureter is a Httle the longer because the left kidney is the higher. They are flattened tubes with a lumen of 3 mm. ( }i in.; and possess muscular and fibrous walls. The contraction of the marked muscular walls explains the intensity of renal colic. The back-fiow of urine from the bladder in diseased conditions may distend the ureters until they approach in size the small intestine. Course. — The ureter is in two parts, an abdominal, extending to the brim of the pelvis, and a pelvic part, which is about 2.5 cm. {1 in.; longer than the abdominal. The abdominal portion extends from 4 cm. T i ^ in. ) to the outside of the median line opposite the second lumbar vertebra to 3 cm. ( i ^ in. ) outside of the median line on a line joining the anterior superior spines of the ilia. It descends on the psoas muscle almost parallel to the median line but inclining a little inward and crosses the brim of the pelvis at the bifurcation of the common ihac artery (the right being sometimes a little lower). It will be observed that at this point the right ureter lies immediately to the inner side of the base of the appendix. There are three narrowed parts; the first or superior isthmus is 7 cm. {2)4. in.; below the hilum, where the ureter turns forward on the psoas muscle; the second or inferior isthmus is at the pelvic brim; and the third is where it enters the bladder. Calculi may lodge at any of these points. If this occurs at the brim in the right ureter the case may be mistaken for one of appendicitis, for the location of the two affections would be almost identical. The abdominal ureter does not possess as distinct a sheath as does the pelvic ureter. It is stuck, however, by fibrous tissue to the peritoneum, so that when the latter is raised it comes up with it. The ureters are crossed about their middle and accompanied by the spermatic or ovarian vessels.. Just below the middle of the abdominal portion of the ureters the genitocrural nerve emerges from the psoas muscle and passes beneath the ureters from within out. This explains the genital pain in cases of calculi. Operations. — The abdominal portion of the ureter can be reached for operative purposes by prolonging the oblique incision used in kidney procedures downward. It should pass about 2. 5 cm. (i in. ) in front of the anterior spine and the same distance above Poupart' s ligament. To find the ureter, Frederick C. Herrick advises carrying the finger to the bifurcation of the common iliac artery and then turning it up against the under surface of the peritoneum where, closely adherent to the peritoneum and covered by some of its reflected fibres, will be found the ureter. After cutting these fibres, traction on the ureter will cause it to stand out as a ridge extending to the base of the bladder. Access to the ureter through the abdominal cavitv is not satisfactory because of the presence of the duodenum and, when distended, the ascending colon on the right side and the sigmoid and distended descending colon on the left. The surest way of recognizing the ureter in operations is to follow it downward from the hilum of the kidney or to ha\'e it contain an ureteral catheter introduced upward into it from the bladder. The ureter (with the kidney) is most often excised for tuberculous disease; therefore, instead of its having its normal size of 5 mm. (4 in.) when distended, its diameter may be increased to 12 mm. or 18 mm. (y^ to ^ in.). Excision has been most often done in women, as in them the pelvic portion is much more accessible. It can be reached through an incision in the anterior vaginal wall at its upper portion instead of using an oblique incision through the abdominal muscles. Konig advised a transverse incision between the lower edge of the ribs and the crest of the ilium. Bovee {Jouryial of Am. Med. Assoc, Oct. 23, 1909) gives the following technic: The cer\'ix uteri is to be drawn downward with a volsellum. On the anterior \-aginal wall, at the uterovesical juncture, a small dimple will be seen. From the outer side of this dimple an incision from one to one and a half inches in length is made downward and outward. By careful blunt dissection the ureter can be exposed, brought down with a hook, and traction made to liberate it as it passes through the broad ligament. Its lower end may then be ligated and divided. At this stage of the operation the pelvic portion of the ureter may be resected or not as desired. Then a transverse incision, four inches or longer, is made through the extraperitoneal portion of the abdominal wall, opposite the lower pole of the kidney (Konig); its inner end need not go beyond the semilunar line. Through this wound the kidney is liberated and brought out and the ureter separated by gentle traction and freeing with the finsrers. THE PELVIS. The pelvis is composed of the two in)iominatc bones, the sacrum, and the coccyx. It is constructed with a view to connecting the lower extremities with the trunk, to support the weight of the trunk and to promote locomotion, to act as a receptacle and protector of the pelvic viscera and to fulfil the function of parturition. developed, the bladder and uterus are almost entirely in the abdomen, and the rectum is almost straight. As the child begins to use its lower limbs for locomotion the pelvis increases progressively with the growth of the lower extremities, and with the advent of puberty its development is completed. The structure of the pelvis in viscera and their functions. That part of the pelvis above the iliopectineal line has been called the false pelvis, while that below is the true pelvis. The inlet of the pelvis is formed anteriorly by the crest and spine of the pubes, the iliopectineal lines on the sides, and the base of the sacrum with its promontory posteriorly. The outlet is formed by the pubic arch anteriorly with the symphysis in the middle, the rami of the pubes and ischia on the sides, and the great sacrosciatic ligaments and coccyx posteriorly. The viscera above the inlet are abdominal, those below are pelvic. When the body is vertical the inlet forms an angle of 60 degrees with the horizon, and the promontory of the sacrum is 9 to 10 cm. (314 to 4 in.) above the upper edge of the symphysis. The male pelvis is fashioned preeminently for locomotion : it is both heavier and rougher ; the false pelvis is broad and shallow, while the true pelvis is deep and narrow and its capacity is less. The inlet is heart-shaped, the tuberosities closer together, and the pubic arch narrower. The obturator foramen is oval (see Figs. 438 and 439). The Female Pelvis. — In addition to the functions common to the two sexes the female has that of child-bearing. To fullil this the female pelvis is different from that of the male. It is smoother, its bony prominences not being so mariced (see Fig. 440). The extreme width of the pelvis does not differ much in the two sexes, some authorities giving them as of equal size and some stating that the female is slightly narrower. Its cavity is larger and shallower. The symphysis pubis is narrower and the sacrum is shorter and less curved. The acetabula are set wider apart as are also the tuberosities. This causes the thyroid foramen to be triangular in the female while it has a long diameter parallel with the long axis of the body in the male. It also causes the subpubic angle to be greater in the female, forming an angle of about 90 degrees as against 65 degrees to 70 degrees in the male. The inlet of the female pelvis is more oval and not so heart-shaped. The cavity is largest at a level between the second and third sacral vertebrae posteriorly and the middle of the symphysis anteriorly. It is smallest between the sacrococcygeal articulation behind and the lower third of the symphysis in front, and the spines of the ischia on the sides. There are three diameters of the pelvis used in obstetrics. Sacro-iliac Articulation. — The sacrum is wider in front than behind and larger above than below. This causes it to be wedged between the two ilia where it is firmly held by the sacro-iliac ligaments, the irregularity of the joint surfaces and the thinness of the cartilaginous layer. A small amount of movement is possible in most cases : it takes place around a transverse axis about opposite to the second sacral foramina. If relaxation of the ligaments occurs through pregnancy, osteo-arthritis or the stress of strains due to occupation, etc. , symptoms of looseness and discomfort appear which demand relief. Flexion produces pain. Treatment consists in fixing the joints by firm belts around the pelvis or applying a low plaster of Paris jacket or spinal corset or brace which both compresses the pelvis and fixes the lumbar spine and prevents movements in both antero-posterior and lateral directions. The cavity of the pelvis is narrowed somewhat by the soft parts on its sides. The blood-vessels, nerves, and obturator muscles are placed laterally and so usually escape injury. In pregnancy the venous flow is most often interfered with. The first evidence of this is the dusky hue of the vagina; hemorrhoids and varicosities of the veins of the external genitals and lower extremities are common. The rectum and bladder being placed more anteroposteriorly, interference with their functions is frequent. The peculiarities of the female pelvis are evident from birth and are not solely acquired with age. Pelvic Walls. — On looking laterally at the inside of the pelvis, the iliopectineal line is seen separating the abdominal from the pelvic portion. On the iliac or abdominal portion lie the iliacus and psoas muscles. Below the iliopectineal line anteriorly is the body of the pubis with the symphysis in the median line. The descending ramus of the pubis passes down to be continuous with the ramus of the ischium to the tuberosity. A short distance above the tuberosity is the spine of the Ischium. Posteriorly are the five vertebrae of the sacrum and the four of the coccyx. Passing vipward from the tuberosity of the ischium to the sacrum is the great sacrosciatic ligament ( Hgamentutn sacrotuberostun) ; passing backward from the spine of the ischium to the sacrum and coccyx is the lesser sacrosciatic ligament (ligamentimi sacrospinosum) . The large opening above the lesser sacrosciatic ligament is the great ■sacrosciatic foramen. Through it pass the pyriformis muscle, with the gluteal vessels and superior gluteal nerve above, and, below, the sciatic vessels and nerves, the internal pudic vessels and nerve, the inferior gluteal nerve, and the nerves to the obturator internus and quadratus femoris. The smaller opening below the lesser sacrosciatic ligament is the lesser sacrosciatic foramen, through which passes the tendon of the obturator internus, the nerve to it, and the internal pudic vessels and nerve. In front of these two foramina is a third, the obturator. It is closed by a membrane except at its upper inner portion, which gives exit to the obturator vessels and nerve. Attached to the inner surface of this membrane is the origin of the obturator internus muscle and to its outer surface the obturator externus (Fig. 441). Pelvic Floor. — The pelvic outlet is closed by two muscles, the levator ani and coccygeus. These on each side constitute the pelvic floor. The coccygeus is a comparatively small muscle passing from the spine of the ischium to the coccyx. The levator ani is the main muscle which supports and retains the pelvic and abdominal viscera in their normal positions. It arises from the " white line" — which is a thickening of the pelvic fascia extending from the posterior surface of the pubes in front to the spine of the ischium behind — and descends to be attached to the coccyx posteriorly, then around the lower portion of the rectum just above the external sphincter and, farther front, surrounds the vagina of the female or the prostate gland in the male. The part surrounding the prostate has been called the levator Pelvic Herniae. — Hernial protrusions of the pelvic contents may occur through the upper portion of the obturator membrane, following the vessels and nerve. This is called an obturator hernia. The sac is usually to the medial or inner side of the vessels and nerve. It makes its appearance in Scarpa's triangle and is covered by the pectineus muscle. Death has frequently occurred in these cases from strangulation. Sciatic hernia is the name given to those forms in which the intestine escapes through the great sciatic notch, passing just above or just below the pyriformis muscle. Perineal hernice are those which work their way downward in' other places. Thus the sac may push down between the rectum and bladder and bulge in the perineum. It may pass between the coccygeus and levator ani muscles or between the fibres of the latter and bulge into the ischiorectal fossa or forward into the labium of the female. loosened and turned down. aflection and if marked may drag down the peritoneum so that some coils of small intestine may be around the prolapsed part. In childbirth the pelvic outlet is frequently torn and the vagina prolapses and may drag the uterus down with it, or, the support being lost, the uterus descends and drags the vagina with it and everts it. The vaginal outlet, if much relaxed, allows the rectum to bulge downward and forward, forming a rectocele, or the bladder may bulge downward and backward, forming a cystocele (see Fig. 466, page 463). The Pelvic Fasciae. — As the iliac fascia passes over the brim of the pelvis it covers the internal obturator muscle on the walls of the pelvis, hence it is called the obturator fascia. From the upper posterior surface of the arch o\ the pubes anteriorly to the spine of the ischium posteriorly this obturator fascia is thickened, forming the '' white line'' to give origin to the levator ani muscle. At the white line the obturator fascia gives off a visceral layer— the rectovesical fascia— which covers the inner or upper surface of the levator ani, then a second layer, the anal fascia, covering the under or outer surface of the levator ani muscle, while the obturator fascia itself is continued down on the obturator internus muscle to form the outer wall of the ischiorectal space. The rectovesical fascia passes downward and inward over the levator ani muscle to cover the pyriformis and coccygeus muscles behind, then the rectum, vagina, and bladder in front. In the male it covers the prostate gland, forming its sheath, and at its anterior portion forms the deep or posterior layer of the triangular ligament of the perineum. This pelvic fascia acts as a barrier between the abdominal and pelvic cavities above and the perineal region below. Pus originating above it tends to form an abscess which rises toward the abdominal cavity, and pus originating below it tends to work toward the surface in the perineum. Iliac Vessels. — The iliac arteries commence at the bifurcation of the aorta on the left side of the disk between the third and fourth lumbar vertebra;. This is 2 cm. (^ in.) below and to the left of the umbilicus and on a le\el with a line joining the highest points of the iliac crests. They run in a line drawn from this point to midway between the anterior superior spine of the ilium and the symphysis pubis. This is to the inner side of the middle of Poupart's ligament. They are about 15 cm. (6 in.) in length, the upper third, 5 cm. {2 in.), being the common iliac and the lower two-thirds, 10 cm. (4 in.), being the external iliac arteries. The internal iliac comes off opposite the sacro-iliac joint on or a little above a line joining the anterior superior spines. The right common iliac artery is a little the longer because it comes from the left side of the vertebral column, and the left common iliac vein is the longer because it goes to the right side. The left iliac veins lie to the inner side of the left iliac arteries in their entire course. The light iliac vein starts at the inner side of the right external iliac artery and then passes behind it to reach the vena cava on the right side of the vertebral column. The ureters cross the iliac arteries at their bifurcation, and in the female are accompanied by the ovarian arteries and veins. The genitocrural nerve passes downward on the external iliac artery and goes with it beneath Poupart's ligament. Lymphatic nodes accompany the iliac vessels and drain the lower extremity, the abdomen below the umbilicus and the pelvic \'iscera. Ligation of the Iliac Arteries. — The iliac arteries can be reached for ligation through an incision 2 cm. above and parallel to Poupart's ligament, reaching from the inner side of the external iliac artery to above the anterior superior spine if necessary. If the external iliac only is to be ligated this can be done through a comparatively small incision, but if it is desired to reach the internal or common iliac then the incision must be quite large. When the peritoneum is reached it is lifted up from the iliac fascia beneath and the external iliac artery followed up as far as desired. When the peritoneum is raised the ureter is usually lifted with it; it will be encountered crossing the point of bifurcation of the common iliac into the external and internal iliacs. The relation of the ^•eins to the iliac artery on the two sides is to be borne in mind when passing the needle (Fig. 443). Ligation of the iliac arteries by a transperitoneal instead of subperitoneal route has been advocated by Dennis {Medical News, Phila., 1SS6). This lessens the danger of wounding the deep circumflex iliac and deep epigastric arteries, the vas deferens, the ureter, puncturing the veins and loosening up the subperitoneal tissue. Treves has used a median incision from the umbiUcus to the pubes. RECTUM AND ANAL CANAL. The rectum extends from the level of the third sacral vertebra to where it pierces the levator ani muscle, 3. 7 cm. ( i j^ in. ) in front of the tip of the coccyx, but at a lower level, and opposite the lower and anterior part of the prostate. It is 8.75 cm. (2>}4 in. ) long and passes into the anal canal ; this latter is 2.5 to 4 cm. ( I to I ^ in.) long-, and extends to the skin border (Fig. 445). When collapsed the rectum appears as a nearly straight tube following the curve of the sacrum, but when distended it becomes distinctly sacculated It possesses an external longitudinal and internal circular layer of muscular fibres. The longitudinal fibres are continuous with those on the colon but instead of being composed of three bands are fused together into two bands, anterior and posterior. On the sides the longitudinal fibres' are not so abundant. The circular fibres are continuous on the anal canal as the internal sphincter. For the distance of 4 cm. ( i >^ in. ) between the tip of the coccyx and its termination, the rectum lies on the two levator ani muscles, which join in the median line. The lower portion of the rectum is larger than the upper and is called the ampulla. The anterior surface of the rectum at the ampulla lies against the posterior surface of the prostate but is not intimately adherent to it. At the apex of the prostate the anterior rectal wall makes a more or less sharp turn backward. At this part the rectum and the prostate are embraced by the fibres of the levator ani muscle, which practicallv blend with the compressor urethrae muscle and surround the membranous urethra. ' The muscular fibres passing from the longitudinal layer of the rectum to the membranous urethra have been called by Proust the redo-urethralis vinscle ; they keep the louver extremity of the ampuha of the rectum in close approximation to the apex of the prostate. This is the part of the rectum which has been frequentlywounded in the operations of perineal lithotomy and prostatectomy. In the latter operation division of this band allows the rectum to be pushed back and exposes the apex of the prostate. The sacculation of the rectum is produced by three creases or crescentic folds, called the 7'ectal valves or valves of Houston {^Dublin Hospital Reports, 1830). Of these the middle is the largest. It springs from the right anterior quadrant about 5 to 6 cm. (2 to 2]/^ in.) above the margin of the anal canal. The superior and inferior valves spring from the left posterior quadrant a short distance above and below the middle valve. At the juncture of the rectum and sigmoid flexure there is another fold on the anterior wall which tends to obstruct the view in making examinations. These valves are composed of connective tissue and circular muscular fibres covered with mucous membrane. Peritoneal Relations. — The posterior portion of the rectum has no peritoneal covering, the mesosigmoid ceasing opposite the third sacral vertebra, about 12.50 cm. (5 in. j from the anus. From this point the peritoneum slopes downward and forward, covering the sides and anterior surface of the rectum 5 cm. (2 in.) lower. The peritoneum is here reflected forward o\er the bladder in the male forming the rectovesical pouch and over the vagina and uterus in the female form.ing the pouch of Douglas. It is within 7.5 to 8.5 cm. (3 to 3}^ in.) of the anus. This leaves 2.5 cm. ( I in. ) or more above the prostate which is not covered by peritoneum. It was through this space that the bladder was formerly tapped with a trocar to relieve it when distended. The peritoneum on the sides is less firmly attached to the rectum and pelvic colon than it is on its anterior surface. Rectal Examination. — The finger can palpate the anal canal and rectum for a distance of 10 cm. (4 in. ) from the surface. Anteriorly as soon as the finger passes the sphincters the apex of the prostate can be felt ; also the membranous urethra, particularly if it contains a bougie or sound. The prostate can be outlined and its size determined. If the prostate is not enlarged the base of the bladder above can be palpated and the tip of the finger will reach the rectovesical pouch. From the upper or posterior edge of the prostate and extending from near the midline upward and outward are the seminal vesicles, sometimes the seat of tuberculous disease. Just to the outer side of the upper end of the seminal vesicles are the lower ends of the ureters. Should a ureteral calculus become impacted at this point it might possibly be felt through the rectum. Posteriorly the coccyx and the hollow of the sacrum can be felt. The segments of the coccyx frequently are luxated or fractured and it is the seat of pain — coccygodynia — for which excision is done. These injuries cause either an ankylosis or a deformity of the coccyx which can often readily be detected by a finger internally and the thumb externally. Laterally the finger can explore the region of the spine of the ischium, the sacrosciatic foramina, and the tuberosities. If a patient is placed in the knee-chest position and a speculum is introduced the rectum immediately distends with air and its interior is visible as far as the promontory of the sacrum. By means of extra long tubes even the sigmoid loop can sometimes be seen. The valves of Houston are readily seen through the speculum. the peritoneal cavity. The Anal Canal. — This extends from the rectum to the anus or its opening on the skin, a distance of 2.5 to 4 cm. (i to i^ in.). It begins at the level of the levator ani muscles and has the apex of the prostate directly in front of it and the tip of the coccyx behind and a little above. With the body vertical the anal canal has its axis inclining upward and forward toward the bladder; as soon as the sphincter ani is passed the axis of the rectum changes to upward and backward toward the hollow of the sacrum. In intruducing a speculum it should always be inclined first anteriorly and then posteriorly. Opposite the level of the levator ani the circular muscular fibres increase to form the internal sphincter. This extends down the anal canai for a distance of approximately 2.5 cm. (i in. ) and ends above the skin margin or, as it has been called, the "white line of Hilton." The external sphincter surrounds the lower part of the canal and stretches in a spindle shape from the tip of the coccyx to the central point or tendon of the perineum. Anteriorly it blends with the fibres of the levator ani and the other muscles of the perineum. It is a thick, powerful, voluntary muscle and extends outward from the white line of Hilton or mucocutaneous junction. Mucous Membrane. — The upper half of the mucous membrane of the anal canal has six or eight longitudinal ridges or folds called the columns of Morgagni or GlisS071. Between the lower ends of these columns are small hollows called the crypts of Morgagni, and the free edges of the mucous membrane guarding the crypts are the a7ial valves. teric. It descends in the pelvic mesocolon until it reaches the rectum, when it divides into two lateral branches. These descend on its surface to about its middle, when they subdivide into six or eight branches which pierce the muscular coat and descend in the submucosa, one beneath each column of Morgagni. At the lower end of the rectum and anal canal they anastomose with the terminal branches of the middle and inferior hemorrhoidal arteries. The middle hemorrhoidal arteries, one on each side, come from the anterior branch of the internal iliac. They descend on the lower part of the rectum and supply the posterior portion of the bladder and vagina, or prostate and seminal vesicles, the lower anterior half of the rectum and upper part of the anal canal, and anastomose with the superior hemorrhoidal branches above and the inferior hemorrhoidal below. The inferior hemorrhoidal arteries, two or three on each side, are given ofl from the internal pudic while in Alcock's canal, at the outer posterior portion of the ischiorectal fossa ; they pass inward and downward to supply the outer surface of the levator ani and internal and external sphincters and lower portion of the rectum and anal canal. They anastomose with the middle and superior hemorrhoidals. They are distributed more to the posterior portion of the lower part of the rectum and anal canal while the middle is distributed more to its anterior portion. The middle sacral artejy passes down in the median line from the bifurcation of the aorta to the tip of the coccyx, where it ends in Luschka's gland. It gives a few branches to the rectum at its upper part but they are supposed not to go deeper than the muscular coat. It anastomoses with the superior hemorrhoidal. Veins.— The veins of the rectum and anal canal accompany the corresponding' superior, middle, and inferior hemorrhoidal arteries. They form two plexuses, an internal submucous plexus and an external plexus on the surface of the rectum. The internal plexus in the submucous coat begins at the anus in fine venous capillaries which pass upward, mainly in the columns of Morgagni, where they form small dilatations or pools and unite into larger branches which pierce the muscular walls about the middle of the rectum to empty into the main superior hemorrhoidal veins and thence into the inferior mesenteric. of the sphincters and levator ani muscles and pass thence to the internal pudic veins. The middle hemorrhoidal vein drains the blood from the external hemorrhoidal plexus on the outer surface of the lower half of the rectum and empties into the internal ihac. It anastomoses with the superior hemorrhoidal above, at about the middle of the rectum, and the inferior hemorrhoidal below, at the upper portion of the anal canal. It is thus seen that the interior of the lower half of the rectum is drained by the superior hemorrhoidal and its exterior by the middle hemorrhoidal. The blood from the upper part of the anal canal drains into the superior hemorrhoidal, that from its lower part into the inferior hemorrhoidal. The blood from the superior hemorrhoidal veins empties into the portal system through the inferior mesenteric, and the blood from the middle and inferior into the general venous system through the internal pudic, internal iliac, and inferior cava. These veins are usually regarded as being without valves, though the opposite view is held by some. Lymphatics, — According to Poirier andCuneo there is a superior group accompanying the superior hemorrhoidal vessels and draining the mucous membrane of the anal canal and rectum and terminating in the nodes of the pelvic mesocolon after traversing the pararectal lymph-nodes ; also a middle group partly communicating or, as it has been called, the "white line of Hilton." The external spJiincter surrounds the lower part of the canal and stretches in a spindle shape from the tip of the coccyx to the central point or tendon of the perineum. Anteriorly it blends with the fibres of the levator ani and the other muscles of the perineum. It is a thick, powerful, voluntary muscle and extends outward from the white line of Hilton or mucocutaneous junction. Mucous Membrane. — The upper half of the mucous membrane of the anal canal has six or eight longitudinal ridges or folds called the colutnns of Morgagni or Glisson. Between the lower ends of these columns are small hollows called the crypts of Morgagni, and the free edges of the mucous membrane guarding the crypts are the a7ial valves. teric. It descends in the pelvic mesocolon until it reaches the rectum, when it divides into two lateral branches. These descend on its surface to about its middle, when they subdivide into six or eight branches which pierce the muscular coat and descend in the submucosa, one beneath each column of Morgagni. At the lower end of the rectum and anal canal they anastomose with the terminal branches of the middle and inferior hemorrhoidal arteries. The middle hemorrhoidal arteries, one on each side, come from the anterior branch of the internal iliac. They descend on the lower part of the rectum and supply the posterior portion of the bladder and vagina, or prostate and seminal vesicles, the lower anterior half of the rectum and upper part of the anal canal, and anastomose with the superior hemorrhoidal branches above and the inferior hemorrhoidal below. The infei'ior hemorrhoidal arteries, two or three on each side, are given of? from the internal pudic while in Alcock's canal, at the outer posterior portion of the ischiorectal fossa ; they pass inward and downward to supply the outer surface of the levator ani and internal and external sphincters and lower portion of the rectum and anal canal. They anastomose with the middle and superior hemorrhoidals. They are distributed more to the posterior portion of the lower part of the rectum and anal canal while the middle is distributed more to its anterior portion. The middle sacral ai'tery passes down in the median line from the bifurcation of the aorta to the tip of the coccyx, where it ends in Luschka's gland. It gives a few branches to the rectum at its upper part but they are supposed not to go deeper than the muscular coat. It anastomoses with the superior hemorrhoidal. Veins.— The veins of the rectum and anal canal accompany the corresponding superior, middle, and inferior hemorrhoidal arteries. They form two plexuses, an internal submucous plexus and an external plexus on the surface of the rectum. The internal plexus in the submucous coat begins at the anus in fine venous capillaries which pass upward, mainly in the columns of IMorgagni, where they form small dilatations or pools and unite into larger branches which pierce the muscular walls about the middle of the rectum to empty into the main superior hemorrhoidal veins and thence into the inferior mesenteric. The middle hemorrhoidal vein drains the blood from the external hemorrhoidal plexus on the outer surface of the lower half of the rectum and empties into the internal iliac. It anastomoses with the superior hemorrhoidal above, at about the middle of the rectum, and the inferior hemorrhoidal below, at the upper portion of the anal canal. It is thus seen that the interior of the lower half of the rectum is drained by the superior hemorrhoidal and its exterior by the middle hemorrhoidal. The blood from the upper part of the anal canal drains into the superior hemorrhoidal, that from its lower part into the inferior hemorrhoidal. The blood from the superior hemorrhoidal veins empties into the portal system through the inferior mesenteric, and the blood from the middle and inferior into the general venous system through the internal pudic, internal iliac, and inferior cava. These veins are usually regarded as being without valves, though the opposite view is held by some. Lymphatics. — According to Poirier andCuneo there is a superior group accompanying the superior hemorrhoidal ^•essels and draining the mucous membrane of the anal canal and rectum and terminating in the nodes of the pehic mesocolon after traversing the pararectal lymph-nodes \ also a middle group partly communicating with the above through the pararectal lymph-nodes while the remainder accompany the middle and infer'ior hemorrhoidal vessels and drain the lower part of the anal canal above the white line. A third group comes from the skin of the margin of the anus and drains into the inguinal nodes. The pararectal (anorectal of Gerota; nodes may become enlarged in cases of nonmalignant ulcer and can be felt in the region of the ampulla by the finger introduced through the anus, thus leading to a mistaken diagnosis of carcinoma (Fig. 447). Nerves. — The anus is supplied by the inferior hemorrhoidal branch of the internal pudic ner\e, which, as shown by Hilton, crosses the ischiorectal space on the outer surface of the levator ani muscle and passes between the internal and external sphincters to emero-e between them at the white line, from whence it sends filaments up on the mucous membrane and down on the skin. This explains the great sensitiveness of the region. It also supplies the external sphincter, hence the association of spasm with pain. AFFECTIONS OF THE RECTUM AND ANUS. Examination. — If the buttocks are drawn aside the mucous membrane of the anus is everted and a considerable portion of the anal canal becomes visible. The lower part of the columns and crypts of Morgagni and the anal valves are seen. If the patient strains or bears down, the mucous membrane of the anal canal is brought into view in almost its entire length. One is thus enabled to see dilated veins or hemorrhoids, ulcers, fissures, foreign growths, both benign and malignant, and the openings of fistulae. By means of a speculum the entire anal canal can be seen. It should be introduced pointing obliquely anteriorly, and if it is desired to view the interior of the rectum above after it has passed the internal sphincter it is to be directed obliquely upward and backward. In digital examination the first resistance encountered is that of the external sphincter; as its edge is passed a sulcus can often be felt, immediately following which the internal sphincter is passed and the finger enters the rectum. The sulcus is about opposite the crypts of Morgagni and is formed by the interval between the contraction of the external sphincter below and the internal sphincter blended with the insertion of the levator ani above. It is just above Hilton's white line. Imperforate Anus. — In an early stage of the development of the embryo the cloaca is the common termination of the genito-urinary system and the intestinal canal. A depression in the skin called the anal pit appears opposite the rectum and the membrane between disappears in the fourth month. This membrane is produced by the growing together of the ectoderm and entoderm, the mesoderm being pushed aside. The failure of this membrane to perforate forms imperforate anus. The method of development explains the various malformations of these parts. The anal pit may be absent ; the membrane may not perforate ; the rectum may end in a blind pouch some distance up from the anus ; or it may discharge through a sinus into the bladder or vagina. Hemorrhoids. — Hemorrhoids or piles are varicosities or dilatations of the veins of the anus or anal canal. The middle hemorrhoidal veins are not enlarged because they do not drain the mucous membrane, they are not inside but outside the rectum. When the inferior hemorrhoidal veins are dilated they form external hemorrhoids and are situated at the margin of the anus below the white line and external sphincter, and they cannot be replaced in the rectum. When the superior hemorrhoidal veins are dilated they form internal piles (Fig. 448). There is a natural tendency for external piles to be covered almost wholly by skin and for internal piles to be covered solely by mucous membrane. Inflamed internal piles can be pushed back in the rectum. If an internal pile is continued down over the white line or an external pile is continued up over the white line then they are called intero-external piles. Hemorrhoids consist almost wholly of dilated venous sinuses. The existence of arterial hemorrhoids is now denied although small arterial branches are sometimes encountered in the ordinary venous pile. The strawberry pile is composed of venous capillaries instead of the larger venous canals usually present. They bleed more freely than does the ordinary venous pile. When external hemorrhoids are operated on they are usually thrombosed. They are then incised and the clots turned out; at other times when not inflamed they are excised and the edges stitched with catgut or the wound packed. Internal piles are either ligated or treated with the clamp and cautery. In applying the ligature the base of the pile is loosened below near the white line and detached for some distance above and then ligated. This is facilitated by the loose attachment of the mucous membrane. Bleeding is not marked because the blood-vessels enter the pile from above. In Whitehead's operation, or excision of the pile-bearing area, the mucous membrane is readily separated by blunt dissection from the parts beneath owing to the laxity of the submucous tissue; it is then excised and the cut edge sewn to the skin at the anus. Fistula. — Fistula in ano may start as an ischiorectal abscess which perforates internally into the rectum or anal canal and externally through the skin. It may also start as an ulcer of the mucous membrane of the rectum or crypts of Morgagni and then produce an ischiorectal abscess which finally opens on the skin. The most common site of the internal opening is just above the anus and below the insertion of the levator ani. This is in the groove between the external and internal sphincters. Sometimes, however, the tistula pierces the levator ani and opens into the ampulla of the rectum. As the external opening is usually to the outer side of the external sphincter this latter is divided in operating, as is also a part or all of the internal sphincter if the opening is high up. Incontinence of faeces is usually avoided if the sphincter is only divided at one place and at right angles to its fibres, not obliquely. a hemorrhoid. Its location, involving the white line, explains its great pain. Excision of the Rectum. — The rectum can be removed either by the perineal or sacral route. In the perineal operation the incision is made from near the base of the scrotum to the coccyx, surrounding the anus. If the incision is made near the white line the external sphincter is saved and turned to each side with the skin flap. The external sphincter is split anteriorly as far as the central point of the perineum and posteriorly to the coccyx. The rectum being drawn forward the levator ani muscle is cut through on its sides and posterior surface about 4 cm. (i ^ in.) above the anus, the coccyx, if necessary, being excised. The rectum is then drawn back, the finger slipped beneath the anterior portion of the levator ani, which is farther from the surface than the posterior, and it is divided. These fibres practically constitute the recto-urethralis muscle of Proust. This is near the apex of the prostate ; from here up to the peritoneal reflection or rectovesical pouch the rectum is loosely attached but at that point it is necessary to divide the rectal fascia (a part of the rectovesical fascia, p. 435) on the sides, where it passes as two strong fibrous lateral pelvi-rectal bands below the level of the ureters to the fourth sacral foramina, after which the rectum can be drawn still further down. If it is desired to go still higher the peritoneum may be pushed up off the rectum or it may be opened and the mesorectum detached close to the sacrum so as not to injure its vessels. The detached rectum is then brought down, cut off, and its divided end sutured to the skin. In approaching the rectum by the sacral route an incision is made across the sacrum opposite the third sacral segment and from its right extremity (Tuttle) down to beyond the tip of the coccyx. The bone is chiselled through opposite the fourth sacral foramina and the flap turned down (Fig. 449). The lateral and middle sacral arteries may ha\-e to be ligated. The peritoneum, which is visible in the upper portion of the wound, may then be incised close to the rectum to avoid wounding the ureters, and the mesorectum detached close to the sacrum. This loosens the rectum, which can then be brought out and the opening in the peritoneum sewed THE BLADDER. When fully distended the normal bladder contains approximately 500 c.c, or a pint. Its capacity varies much, and it is capable of great distention without rupture. In cases of retention of urine it may reach up to the umbilicus and contain a quart or more, while if its walls are thickened it may be contracted and hold only a few ounces. The shape of the bladder is dependent on the amount of dilatation and its attachments. Position. — In front of the bladder is the symphysis and body of the pubes, below and in front is the prostate gland. Beneath is the posterior portion of the prostate, the seminal vesicles, the termination of the ureters, and the rectum. The upper and posterior surfaces are covered by peritoneum and small intestines, which fill the rectovesical pouch. In the female the bladder rests on the upper half of the vagina and the uterus as far as the internal os. Attachments. — The bladder is fixed at its upper and lower portions. It has true ligaments of fascia and false ligaments of peritoneum. The pelvic fascia is reflected from the levator ani muscles onto the bladder and prostate. Its reflection from the levator ani onto the bladder occurs at its upper portion on each side and is called the latei^al true ligaments (Fig. 450) . The reflection from the anterior part of the bladder and prostate which goes to the posterior surface of the pubes is called the puboprostatic ligament or anterior true ligament of the bladder. The urachus forms a ,superior ligament. The false ligaments are simply the peritoneal reflections. That •over the urachus is the anterior false ligament, and those on the sides, which are reflected from the bladder at about the level of the white line are called the lateral false ligaments. When the urachus above is detached the bladder is comparati\'ely loose. Its firmest attachment is at its neck to the prostate and to the rectum above the prostate at the rectovesical pouch. It is this firm attachment which causes the mucous membrane of the base of the bladder to remain smooth while the rest is corrugated. Shape. — The shape of the bladder is influenced by its attachments. As we have just seen these are the urachus in front, the neck below, and the rectovesical pouch behind ; therefore, as the bladder collapses it assumes a conical shape with its apex at the neck and its base running from the top of the symphysis anteriorly to the highest point of attachment to the rectum posteriorly. The bladder never sinks entirely below the top of the symphysis, because the urachus holds it there; as its top or fundus descends it sinks behind the svmphysis and slopes back to the rectum. If the bladder-walls are actively contracted or much thickened it cannot readily collapse, and then retains a more elongated shape. As it distends it becomes oval and rises toward the umbilicus (Fig. 451). Peritoneum. — In children the bladder is practically an abdominal organ ; when it is empty the peritoneum sinks about to the level of the top of the symphysis, but when distended it rises from 2.5 to 6.25 cm. (i to 2^ in.) above. In the adult the top of the bladder is held to the top of the symphysis by the urachus, and as it becomes empty the upper surface descends until a curved line is formed from the top of the symphysis downward and backward to the rectovesical pouch, which is opposite the insertion of the ureters and corresponds to a point just below Fig. 451. — The bladder in its empty and distended state. When distended the peritoneal reflection un the anterior abdom.inal wall is seen to be raised. The posterior or rectovesical reflection remains nearly or quite unchanged. posterior border of the prostate. As held by Greig Smith, the main factor in raising the peritoneum from the front of the bladder above the upper edge of the symphysis is its distention, and 450 to 600 c.c. (15 to 20 oz. ) will raise the fold 2.5 to 5 cm. (i to 2 in. ). When the body is placed in the Trendelenburg posture the contents of the bladder gravitate toward the diaphragm, and therefore push the peritoneum up or away from the upper border of the symphysis : hence this position is usually employed when the bladder is to be opened for operative purposes. The use of a rubber bag in the rectum distended with water has been found to raise the peritoneal folds so little that its use has been abandoned in favor of the Trendelenburg posture. Posteriorlv the rectovesical pouch is approximately 8.75 cm. (3J4 in.) from the anus, but it may be as little as 7.5 cm. (3 in.), or as much as 10 cm. (4 in.). As has already been stated the attachment of the rectovesical pouch to the rectum is so firm that whether the bladder is distended or collapsed its distance from the prostate is but little altered. It does not change its position markedly as does the peritoneum abo\-e the pubes. Waldeyer (Joessel and Waldeyer, Topog. Chiriug. AjiaL, vol. ii, p. 554) gives 1.5 to 2 cm. (f to i in.) as the greatest possible variation. is influenced as just detailed above. In front of the anterior bladder wall and between it and the posterior surface of the symphysis and transversalis fascia is the space of Retzius, filled with loose connective tissue. Care is to be taken not to infect it in operative procedures. It readily becomes infiltrated in extravasation of urine. Rupture of the bladder occurs most often through the peritoneum of its posterior surface when the bladder is distended. Extraperitoneal ruptures may occur when it is empty, and are usually the result of wounds by foreign bodies or spicules of bone in fractures. Base of the Bladder, — On the interior of the base of the bladder the ureters open about 2.5 cm. (i in.) posterior to the urethral orifice, and the same distance (or more if the bladder is distended) from each other. The included triangular space is called the trigone. Its mucous membrane is without the rugae possessed by the rest of the bladder and, if it is distended, is not quite so pale in color. The ureters pass obliquely through the walls a distance of 1.25 cm. (y^ in.) and cause slight ele\-ations of the mucous membrane called the plicce lortericce or ureteric folds. Joining the two ureteral orifices is a fold of mucous membrane called by Kelly the interureteric ligament. The part immediately posterior to this fold is xhe postprostatic pouch or bas-fond. It becomes enlarged in prostatics, and then contains residual urine. Calculi also tend to lodge there (Fig. 452). Bladder "Walls. — The bladder is composed of a muscular wall covered externally by the peritoneum and internally by the submucous and mucous coats. In the undistended bladder blood-vessels can be seen in the mucous membrane, which is in folds. These folds and vessels diminish or disappear when the bladder is distended. The membrane at the trigone is more firmly connected to the muscle beneath than elsewhere in the bladder, hence its smoothness and increased color. The muscular coat is composed of two longitudinal layers with one more or less transverse layer between. The external layer is continuous with the ureters, and over the prostate to be attached to the lower posterior part of the pubes under the name of pubovesical muscle. The circular fibres are continued around the opening of the urethra, forming the internal sphincter. The openings of the ureters are not closed by muscular action, but by the interior pressure. When the bladder is distended, if the ends of the ureters are thickened they do not close as the urine accumulates, but allow it to back up and distend the ureters and pelvis and even cause the kidney itself to become enlarged. Thus infection ascends from the bladder to the kidney and the ureters become distended until they may equal in size the small intestine. The fibres of the muscular coat pass in various directions, more or less in the form of bundles. W^hen these bundles become hypertrophied they can be seen as distinct ridges on the interior of the bladder. In sounding they can be felt and recognized by the tip of the sound. Such a condition is called a ribbed bladder. If the bladder becomes hyperdistended the fibres become separated and the mucous membrane bulges out, forming a sac. It is then called a sacculated bladder. These sacs are favorite lodging places for \'esical calculi. From diseases of the prostate and urethra the muscular coat becomes thickened. It is then called a hypertrophied bladder ; such a one is usually contracted. The bladder walls ordinarily are quite thin, about 3 mm. {yi in.) thick. When hypertrophied they are three or four times as thick. W^hen the bladder is viewed in life in abdominal operations it usually appears as a somewhat flaccid sac. It does not assume the globular form until considerably distended and must contain a moderately large amount of urine before showing above the symphysis. The commonly flaccid condition of the bladder leads one to think that its emptying is largely favored by the pressure of the intestines compressing it against the floor of the pelvis, and that it is mainly in case of considerable distention or the pressure of irritation or disease that its own muscular coat is utilized for the purpose. This view is strengthened by the increase in flow when coughing and by the occurrence of bladder troubles (prolapse, etc. ) so soon as the integrity of the pelvic floor is injured, as occurs in rupture of the perineum from childbirth. The laxit}^ of the bladder walls allows it to spread sidewise to the neighborhood of the inguinal rings, and it has frequently been found in the inguinal canal and has been wounded in operating for hernia. The urethral orifi.ce in the male is about 6.25 cm. (^2^ in. j from the surface at the upper margin of the symphysis in a downward and backward direction: with the body in a vertical position it might be said to lie on a level with the middle of the symphysis if the bladder is empty, lower if the bladder is distended, and slightly higher if the rectum is distended. It is therefore within easy reach of the finger inserted through a suprapubic incision. The Bladder in the Female. — In the female the vesico-uterine pouch reaches the level of the internal os and the bladder is in contact with the cer\-ix from there down to the cervicovaginal junction or anterior fornix. From here it is in contact with the anterior vaginal wall along its upper half. The trigone extends from the middle of the anterior vaginal wall, which marks the internal orifice of the urethra, to 2 cm. (3^ in.; below the cervicovaginal junction, the spot where the ureters enter the bladder walls. The absence of the prostate causes the bladder to be lower in the female and the level of the internal urethral orifice is opposite the lower border of the symphysis. It also is smaller in the female and does not show itself so readily above the symphysis on distention. \'esicovaginal fistulse frequently occur as the result of injuries during childbirth, cancerous ulceration, etc. They are located on the anterior wall of the vagina above its middle. Calculi can be extracted through an incision in the median line of the anterior vaginal wall above its middle. The commencement of the ureters can also be palpated on each side of the cer\-ix anteriorly and impacted calculi may be removed at that point. The bladder is connected with the cervix and vagina posteriorly by comparatively loose connective tissue so that they can be readily separated by blunt dissection as far up as the internal os. Cystoscopic Examination. — The shortness and distensibility of the female urethra make the examination of the interior of the female bladder much easier than that of the male. For purposes of examination it is distended either with air or water. In order to distend it with air it is either injected directly with a rubber bulb or the patient is put in the knee-chest position, or. if on the back, the pelvis is elevated, so that the intestines gravitate toward the diaphragm. If a speculum is then introduced and the obturator withdrawn the bladder at once distends. The walls of the bladder are whitish in color with small vessels running over them. The base (trigone) of the bladder is redder than the surrounding walls. The muscular fasciculi are often seen as distinct ridges and the mucous membrane may be thrown into folds. The internal orifice of the urethra in the female is just below the lower border of the symphysis. The ureteral orifices can be seen as slightly ele\-ated papillae 2. 5 cm. or more behind the urethral orifice and 30° to its side, the trigone, when the bladder is not distended, making an equilateral triangle, with the urethra and ureteral papilke at its angles (Fig. 453). Operations. — Most of the operations on the bladder are done from above. To relieve distention tapping is done with a fine trocar or aspirating needle. It is to be inserted close to the upper margin of the symphysis and passed downward and back- FlG. 453. — The picture on the left demonstrates a normal mucous membrane and ureteral orifice. On the right the ureteral orifice will be observed to be small, round, atrophic, and functionless. (Drawn from a case of Dr. Benj. A. Thomas* by Mr. Louis Schmidt.) ward. Cystotomy is performed through the median line. In making the incision three layers of fat are divided; first, the superficial fascia between the skin and muscles; second, the fattv pad between the posterior surface of the muscles and the transversalis fascia; and third, the prevesical fat of the space of Retzius beneath the transversalis fascia and between the anterior wall of the bladder and the symphysis pubis. Tumors. — Growths and prostatic enlargements are often operated on suprapubicallv. These are usually easily within reach of the finger. In incising the bladder the anterior vesical veins are to be avoided by keeping in the median line. THE PROSTATE. The normal prostate gland is of the shape of a large chestnut. It is 3 to 4 cm. (i 14^ to xYo in. ) wide, 2. 5 to 3 cm. ( i to 1 14^ in. ) long, and 3 cm. ix]/^ in. ) thick. An indistinct furrow on its under surface separates it into two lateral lobes. There is no median lobe, as the prostatic tissue is continued uninterrupted across the median line. For clinical purposes we may consider the prostate as having an apex, a vesical surface or base, and a rectal or posterior surface. ejaculatory ducts. These enter close together near the median Hne and pass upward and forward to enter the under surface of the prostatic urethra about its middle. It is to the part of the prostatic tissue between the ejaculatory ducts below and the interior of the bladder above, just posterior to the urethral orifice, that the name middle lobe has been applied. This part contains a collection of glands called by Albarran (Albarran and Motz: Annales des Mai. Genito-Urinaires, July, 1902) the prespermatic group. Just beneath the mucosa behind the urethra is another group which he calls the subcervical group. In so-called enlargements of the middle lobe these glands form the bulk of the tissue. A slight enlargement produces a bar, a considerable enlargement produces a projecting growth which may even be pedunculated. The glandular portion of the prostate in addition to that just described posterior to the urethral orifice is located centrally, and the fibromuscular part of the gland is mostly outside of the glandular portion, surrounding it and passing across cross the median line posteriorly, forming an indistinct posterior commissure. Sheath and Capsule. — The prostate is surrounded by a distinct firm fibrous sheath which is continuous with the rectovesical fascia (aponeurosis of Denonvilliers). At the upper portion this blends with the fascia covering the bladder, anteriorly it forms the puboprostatic ligaments, below it is continuous with the deep layer of the triangular ligament of the perineum, posteriorly it is continuous with the rectovesical fascia and covers and binds the seminal vesicles to the bladder. The prostatic plexus of veins is imbedded in this fibrous sheath. (J. W. Thomson Walker, Brit. Med. Jour., July 9, 1904.) (Fig. 454). Between the veins and the glandular tissue, and covering the latter, is what has been called by Sir Henry Thompson and W. G. Richardson ("Development and Anatomy of the Prostate Gland ' ' ) the capsule. It is a comparatively thin layer of fibrous tissue, insignificant and incomplete in places, which penetrates the substance of the gland. It adheres to and is removed with the lobes of the enlarged prostate in prostatectomy. Relations. — Tlie apex rests on the posterior layer of the triangular ligament I to 2 cm. (J-3 to 3/^ in.) behind and a little below the subpubic angle and just inside the upper end of the anal canal. This is about 3 to 4 cm. {i}^ to i}4 in.) above the white line of Hilton and the prostate is immediately felt by the finger as soon as it enters the rectum. The prostate lies on the rectum, so that it is readily accessible. Its apex being about 3 cm. (i}{ in.) from the mucocutaneous white line, its upper edge would be 6 cm. (2i/^ in.) and the rectovesical pouch 8.75 cm. (31-^ in.) above this line. Thus all these structures are usually within reach of the finger. In the median line, extending to each side, the vasa deferentia and seminal vesicles, if diseased, as they sometimes are in tuberculous affections, can readily be felt, but when healthy are too soft to be easily distinguished. On each side is the levator ani muscle, which embraces the prostate as far forward as the membranous urethra, where it practically blends with the deep transverse perineal and compressor urethrae muscles (see recto-urethralis muscle — Perineum, page 475). Structure. — The greater portion of the prostate is composed of unstriped muscular tissue, which is not only arranged peripherally but sends prolongations inward, forming spaces in which the glandular tissue is lodged. There is also a layer surrounding the vesical opening of the urethra. The action of this latter muscle is probably to act as a true sphincter to retain the urine in the bladder. It also by its contraction prevents the regurgitation of the semen into the bladder. Veins. — In the urethral and vesical portions of the prostate are numerous veins. These in the old become varicose, hence the frequency of bleeding in old prostatic cases. Around the anterior portion of the prostate and laterally posteriorly lies the prostatic venous plexus. Into it anteriorly empties the dorsal vein of the penis; from above it receives the vesical veins, and in those advanced in age it communicates also with the hemorrhoidal plexus posteriorly. Fenwick has shown (Jour, of Anat. xix. 1885) that in the young these veins possess valves which become incompetent as age supervenes. The prostatic plexus unites in a single large vein on each side which empties into the internal iliac vein. Hypertrophy. — This is the most common affection of the prostate. According to Mansell Moullin it always begins in the glandular elements. It is of two kinds, fibrous and glandular. Both start as glandular but the former in some cases predominates and the glandular element atrophies and leaves a comparatively small hard fibrous prostate. The glandular character of median growths has already been explained on page 449 as originating from the prespermatic and subcervical groups of Albarran. Glandular hypertrophy of the lateral lobes forms the ordinary large prostates for which prostatectomy is performed. The bleeding, which is so common in these cases of enlarged prostate, is due to the varicose condition of the veins around the posterior portion of the urethra and vesical mucous membrane. ments. It is performed either suprapubically or through the perineum. When done through a suprapubic incision a median enlargement (so-called median lobe) can readily be removed by dividing the mucous membrane with the finger-nail or scissors and shelling the growth out with the finger. In this case there is practically no sheath to go through and the amount of bleeding will be proportionate to the varicose condition of the veins. If large lateral growths are to be removed then there is still no fibrous sheath to be entered, but only the thin, filmy capsule and fibromuscular layer of prostatic tissue covering the hypertrophied glandular masses: hence for its division Freyer uses his finger-nail only. As the fibrous sheath is not divided there is no bleeding from the prostatic venous plexus in its layers. In perineal prostatectomy two methods are used. In the first the membranous urethra is opened by a median incision and then a lateral cut made into the enlarged prostate on each side. The finger is then introduced and the hypertrophied glandular masses enucleated with the finger. In the second method a curved or A-shaped incision is made from the central tendon of the perineum toward each side between the rectum and tuberosities. The sphincter ani is then detached from the central tendon and pushed back while the transverse perinei muscles are pulled forward. The muscular fibres between the rectum and membranous portion of the urethra (page 438, recto-urethralis muscle) are then divided and the rectum pushed back (Fig. 455). This exposes the prostate; its outer capsule or sheath is then incised and the growth removed with the finger or forceps. In order to pre\'ent injury to the eiaculatory ducts Young enucleates through two lateral incisions, thus leaving a middle strip in which the ejaculatory ducts are contained. According to Gosset and Proust (^Manuel de la Prosiatectomie, Paris, 1903) the fascia between the prostate and rectum (aponeurosis of Denonvilliers) is composed of two layers, an anterior one on the prostate— its sheath — and another posterior one on the rectum. When the rectourethralis muscle is divided the incision should likewise divide the posterior or rectal layer, which is then pushed back with the rectum. Thus is formed the ' ' espace External sphincter ani Fig. 455. — The parts involved in prostatectomy. The external sphincter ani has been divided at the central point of the perineum and with the lower portion of the rectum has been drawn back, thus putting the recto-urethralis muscle on the stretch and exposing the prostate to each side. Abscess. — Inflammation and abscess of the prostate follow injury and infection from the introduction of catheters or bougies and also from gonorrhoea. The hot and enlarged gland can readily be felt through the rectum. The bladder and rectal symptoms are marked. Pus tends to discharge either into the urethra or rectum, more rarely it may point in the perineum behind the triangular ligament and in front of the anus. Abscesses breaking into the urethra may leave a large cavity, which becomes a receptacle for pus, urine, and calculi, and hastens a fatal issue. When breaking into the rectum intractable fistulae may result. Prostatic abscesses should be opened by an incision in the perineum just anterior to the anus, the finger being introduced into the rectum to avoid wounding it. THE SEMINAL VESICLES. The seminal vesicles are about 5 cm. (2 in.) long and lie on the bladder above the prostate. They diverge on each side toward the ureters, which they overlap and which intervene between the vesicles and bladder wall. The vasa deferentia run along the inner border of the vesicles and join the ducts from the vesicles to form the common eiaculatory ducts just before entering the posterior portion of the prostate. Their upper portion is covered by the peritoneum of the rectovesical pouch. They are fastened to the bladder by the rectovesical fascia, and are in close relation with the prostatic plexus and vesical veins. They are within reach of the finger introduced through the anus and may be massaged and their contents expressed. They have been excised for tuberculous disease. When normal they are not readily recognized by touch, but in disease are easily felt. Operations on them are conducted like those of perineal pros- muscle and pulling the rectum forcibly back. tatectomy, but, as they lie higher, beyond the prostate, it is almost impossible to bring them well into view for operative purposes. The seminal vesicles are nothing more than blind diverticula from the vasa deferentia and partake of its diseases. The epididymis, vas deferens, seminal vesicles, and prostate are all frequently involved in tuberculosis of the genito-urinary tract (Fig. 456). THE VAS DEFERENS. When the vas deferens leaves the internal abdominal ring it winds around the outer side of the deep epigastric artery and dips down over the brim of the pelvis 4 or 5 cm. (i>^ to 2 in. ) posterior to the pubic spine. It then runs downward and backward on the side of the pelvis, under the peritoneum, crossing superficially the THE UROGENITAL SYSTEM. obliterated hypogastric artery, the obturator vessels and nerve, the vesical arteries, from the inferior of which it receives the artery of the vas, and finally the ureter. In its pelvic course the vas deferens is not often the subject of surgical interference except in cases of undescended testis. In these cases it is often loosened from the firm but thin fibrous bands which retain it in place, after which it is readily drawn forward to allow the testicle to descend. In the early stages of development of the human embryo there arises from the parietal mesothelium on each side a tube known as the Wolffian duct with a collection of tubules known as the Wolffian body. This reaches its full development in the seventh week. On one side of the Wolffian body develops the sexual gla^id, which later becomes either a testicle or ovary. At the caudate extremity of the Wolffian body develops the kidney by the end of the second^month. At this time the bladder is connected by the urachus with the stalk~of the allantois. The lower end of the bladder is connected with the extremity of the intestinal tract through a dilatation FEMALE called the urogenital sinns. The union of the urogenital sinus and intestine forms the cloaca. At the time the Wolffian body is developing there appears alongside of it a tube called the duct of Midler. It atrophies in the male but in the female becomes the Fallopian tube, uterus, and vagina. The ureter is developed and becomes connected with the lower portion of the bladder (Fig. 457). The Wolffian duct and duct of Miiller, until about the third month, empty into the urogenital sinus. Differentiation of the sexes begins about the third month and is well advanced in the fifth. The sexual gland in the male becomes the testicle and passing from its lower end is seen the gubernaculum. In the femak it becomes the ovary and the round ligament passes from its lower end. The Wolffian body after performing temporarily 'the functions of a kidney disappears, leaving sometimes a small cyst attached to the upper part of the epididymis in the male and in the broad ligament near the ovary in the female, known as t\ie hydatid of Morgagni {stalked hydatid). Its lower portion has as its remains some short closed tubes in the tail of the epidid-' ymis known as the paradidymis or organ of Giraldes in the male and the paroophoron of the broad ligament in the female. The Wolffian duct, while forming the vas deferens and part of the epididymis in the male, forms the atrophied paroophoron in the female to the inner side of the ovary. Tho. parov a) 7111)1 or organ of RosenmiiUer is the remains of the middle set of Wolffian tubules and in the male forms the epididymis. In the female it is almost always present as a horizontal tube with shorter tubes connected with it, between the layers of the broad ligament near the o\ary. The Wolffian duct may persist as a small tube in the broad ligament close to the uterus and vagina and known as^ the duct of Gartner. The ducts of Miiller in the male atrophy and form the sinus pocularis of the prostate. Part of them may persist patulous as the duct of Rathke. In the female they form the Fallopian tubes, uterus, and vagina. A knowledge of the development of the urogenital tract enables one to understand how many of its congenital deformities and subsequent aflections are produced. Extrophy of the bladder, epispadias, hypospadias, and various forms of hermaphroditism result when the walls of the bladder and urethra and external genitals fail to develop in the median line. Should the urachus not close, a fistulous tract leads from the bladder to the umbilicus from which urine discharges. Cysts may also form in its course. Should the partition between the rectum within and the dimple of the anus without not become absorbed there is formed one of the varieties of imperforate anus. In some cases the rectum empties into the urethra or bladder, thus forming a cloaca. Should the testicle become arrested in its descent from the region of the kidney it forms what is known as undescended testicle. It may be arrested within the abdominal ca\ity, in the inguinal canal, or near the external abdominal ring. The paroophoron gives rise to cysts which have a tendency to develop between the layers of the broad ligament and are papillomatous inside. The parovarium also gives rise to cysts which likewise tend to burrow between the layers of the broad ligament. Cysts arising from Gartner's duct are sometimes found in the vagina. In the male, cysts arising from the Wolffian duct are : ( i ) encysted hydrocele of the testicle ; and (2) general cystic disease of the testicle. Cysts arising from the persistence in the male of the duct of Miiller have also been observed in the prostate and seminal vesicles, but they are exceedingly rare. THE FEMALE GENERATIVE ORGANS. The female pelvic organs are so often the subject of operative procedures that an exact knowledge of the relations of the uterus, vagina, ovaries, Fallopian tubes, round and broad ligaments, and ureters is of great importance. The normal unimpregnated uterus is approximately 7.5 cm. C3 in.) long, 5 cm, (2 in.) broad, and 2.5 cm. (i in.) thick. It consists of a fundus, body, and neck. Its fundus is that part above a line joining the two openings of the Fallopian tubes at the cornua. The neck of the uterus or cervix embraces 2.5 cm. (i in.) of its lower portion. Between the neck and fundus is the body. The cavity of the uterus is small, its anterior and posterior walls being almost in contact, while laterally it extends toward the Fallopian tube openings. The opening through the cervix is the cervical canal ; it opens into the vagina by the external os and into the uterus by the internal os ; it is round in shape. The external os in the nullipara is round but in those who have borne children it is a trans\erse slit. The cer\ical canal is narrowed at both the internal os and the "external os while it is larger between ; hence in passing instruments into the uterus they traverse with difficulty the external os and the internal os but pass readily between the two and into the uterine cavity beyond. Position. — The uterus is most firmly fixed to the vagina and its upper portion is the most movable. Lying between the bladder anteriorly and intestines and rectum posteriorly its position varies with the condition of those organs. Normally it inclines anteriorly (anteversion j. It lies in contact with the bladder, no intestines intervening. With an empty bladder it may point almost horizontally just above the top of the symphysis pubis, the external os being almost at the same level. As the bladder distends and the rectum becomes empty the fundus rises more and more until the axis of the uterus may coincide with that of the vagina, or even pass beyond ; and then it is said to be retroverted. The uterus is normally almost straight or slightly bent forward. As the result of disease it becomes more or less sharply bent at the region of the internal os either forward or backward. It is then said to be antefiexed or retroflexed. When retroflexed the fundus can frequently be felt as a round hard mass behind the upper posterior portion of the vagina. Attachments. — In addition to being attached to the vagina the uterus has certain folds or ligaments which pass from it to the surrounding parts. Anteriorlv the peritoneum is reflected from the uterus at the level of the internal os to the bladder, forming the titerovesical fold. Posteriorly the peritoneum descends from the uterus over the posterior surface of the upper portion of the vagina for i or 2 cm. (^ in.) and thence onto the rectum constituting the rectovagiyial or 7'ecto-titerhie fold. The deep pouch so formed is called Douglas' s pouch. On each side are three ligaments; the broad ligament is the largest and most important. The two broad ligaments and uterus form a diaphragm which extends from one side of the pelvis directly across to the other, thus dividing it into anterior and posterior compartments. On the side of the uterus the broad ligament extends from the round ligament and Fallopian tube above down to below the level of the internal os. The anterior layer blends with the uterovesical fold at the level of the internal os, while the posterior goes to the bottom of the pouch of Douglas. It passes outward to be attached to the sides of the pelvis from the external iliac vein above down to the floor of the pelvis. Between the two peritoneal layers of the broad ligament at its top is the Fallopian tube, a little lower on the posterior surface is the ovary, going to the ovary are the ovarian vessels; lower still is the round ligament ; and running in the base of the broad ligament are the uterine artery and ureter. At its pelvic attachment the broad ligament widens out, having the round ligament as its anterior edge and the infundibulopelvic or suspensory ligament of the ovary as its posterior edge. This latter runs not to the uterus but to the fimbriated extremity of the Fallopian tube and ovary and contains the ovarian vessels. A little posterior is the uterosacral ligament (recto-uterine); it point it is crossed by the uterine artery. It then incHnes somewhat inward and forward along the sides and anterior wall of the vagina to enter the bladder. Its opening in the bladder is about 2. 5 cm. ( i in. ) below the level of the external os, which is almost as far down as the middle of th^ anterior vaginal wall. The ureters run in the bladder wall obliquely for about 2 cm. (^ in.) and their openings are from 2.5 cm. to 5 cm. (i to2 in. ) apart according to the amount of vesical distention (Fig. 460). The uterine artery comes from the internal iliac and passes almost horizontally inward toward the lower portion of the cervix. As it approaches the cervix it gives off a cervicovaginal branch passing to the upper part of the vagina. At this point it has just crossed in front of the ureter and is about level with the external os. It then inclines upward, reaching the side of the uterus at its junction with the vagina. It passes up the side of the uterus, in nulliparae a short distance away from its side, but in multiparae close to it, until it reaches the cornu above. It here is continuous with the ovarian artery. the male. It crosses the brim of the pelvis in front of the ureter, enters the infundibulopelvic or suspensory ligament of the ovary and runs horizontally towards the uterus in the broad ligament between the round ligament and the ovary. It gives branches to the ovary and tube and as it reaches the cornu of the uterus it crosses in front of the round, ligament and joins the uterine artery. As the uterine and ovarian arteries are continuous with each other either one may be the larger and they vary considerably in size. ease of the ovaries and tubes. Lymphatics (According to Poirier and Cuneo). — The cervix has three sets of lymphatics. The first passes outward and upward along the side of the pelvis anterior to the ureter to empty into the nodes along the external iliac artery. The second set passes backward behind the ureter to empty into a node on the anterior division of the internal iliac artery. The third set passes from the posterior surface of the cervix almost directly backward in the uterosacral ligaments to empty, some into the lateral sacral nodes high up in the hollow of the sacrum and some into the nodes of the promontory (Fig. 461). The Umphatics of the body of the titer us communicate with those of the cen-ix below and at the cornu pass out as four or ti^■e trunks along the broad ligament between the o\-ary and Fallopian tube, being joined by branches from the ovar\-. They pass through the infundibulopelvic (suspensory) ligament and follow the ovarian vessels to empty into the aortic nodes below the kidney. The ovarian lymphatics form four to six trunks which ascend with the ovarian vessels to end in the lower aortic nodes. Opposite the fifth lumbar vertebra they communicate with the trunks from the body of the uterus. Pelvic Examinations. — In making a digital examination the introduced finger recognizes that in the nullipara the vagina is narrow, admitting only, one finger, and rugous on its anterior and posterior walls. In multiparae it is smooth and admits two fingers. As the pulp on the palmar surface of the finger is used and not the side, the finger is to be directed posteriorly into the hollow of the sacrum and then brought anterior (Fig. 4621. As the cervix enters the anterior wall and therefore, if normal, points down and back, and is about 6. 5 to 7.5 cm. (2^ to 3 in. j from the vulvar orifice, it is usually within reach of the tip of the finger. In the nullipara it is felt to be hard, rounded, and projecting distinctly into the vagina with a small os In multiparse it is larger, softer, not so prominent, its os is wider and often irregular in shape from lacerations. The uterus is often displaced so that the os may look forward or to one side. The normal uterus is not firmly fixed but is movable and can be readily moved up and down by the examining finger. If it is in a normal anteverted position it can be felt between the finger of one hand within and firm pressure with the tips of the fingers of the opposite hand from without just above the symphysis pubis. When the uterus retains its normal almost straight shape and falls either forward or backward it is said to be in a position of anteversion or retroversion. If the uterus is bent on itself in the shape of a cun-e it is then said to be anteflexed or retroflexed. In anteversion the external os points down and back, and the fundus can be felt with the other hand abo\e the pubes. In retroversio7i the os looks downward and forward and the body of the uterus cannot readily be made out by bimanual palpation. If anteflexed instead of anteverted it is more difficult to feel the uterus through the abdominal walls but its fundus can be felt through the anterior \-aginal wall in front of the anterior lip of the cer\ix. If retroflexed its projecting rounded fundus can readily be felt in Douglas's sac just behind the cervix. By a digital examination one determines the amount of mobility of the uterus, its size, its position, the condition of the cervix, whether or not it is the seat of indurations such as occur from cicatrices and cancer, whether it is lacerated, etc. Growths like fibroid tumors projecting from the anterior or posterior walls can also be felt. Particularly in thm subjects relaxed by anaesthesia the broad ligaments can be followed to the sides and ■even normal ovaries be recognized. When prolapsed they fall into Douglas's pouch and can be felt posterior to the cervix. Enlarged Fallopian tubes can be feit as distinct masses either fixed to one side of the uterus or prolapsed into Douglas's pouch. Renal calculi impacted in the ureter at its vesical end can be felt between the middle and upper end of the vagina to one side or the other. OPERATIONS ON THE FEMALE PELVIC ORGANS. The most usual operations are the removal of the uterus, — hysterectomy, — removal of the ovary, — oophorectomy, — removal of the Fallopian tubes, — salpingectomy. The ovaries are often removed with the diseased tubes and also in cases of hysterectomy. These operations are usually done through an abdominal incision near the median line between the umbihcus and the symphysis pubis. Not infrequently thev are done through the vagina. After the abdomen is opened it is important to be able to recognize and isolate the individual organs, this is much facilitated by elevating the pelvis so that the intestines gravitate toward the diaphragm — Trendelenburg's position (Fig. 463). The incision having been made and the abdomen opened the lirst structure seen is the great omentum. This often extends as low as the svmphvsis. As it hangs from the transverse colon it is to be displaced upward and not toward the sides. The next structures exposed are either the small or large intestines. The transverse colon normally should not come below the umbilicus but it often does come lower and may even descend to the level of the symphysis. It likewise should be these structures are bound to the posterior abdominal walls and may often be covered in front by coils of small intestine. Quite frequently however, the caecum on the right and iliac colon on the left come in contact with the anterior abdominal walls in the iliac fossa in the neighborhood of the anterior iliac spines and may extend part way down Poupart's ligament. The sigmoid colon if distended may bulge anteriorly but more usually it lies posteriorly covered by the small intestines. If it or the caecum aie encountered they are to be pushed upward and to the side. The small intestines are to be displaced upwards. In the median line anteriorly is now seen the bladder and directly behind it the uterus. If the uterus is drawn to one side the broad ligament of the opposite side is made tense and the round ligament is seen running to the internal ring anteriorly and, more posteriorly, the Fallopian tube. On the posterior surface of the broad ligament below the outer end of the Fallopian tube is seen the ovary. Farther posteriorly, in the hollow of the sacrum, is the rectum, with Douglas's pouch between it and the uterus in front. If it is desired to recognize the structures by touch instead of sight then the anterior abdominal wall is followed down over the bladder and the fundus of the uterus recognized as a hard rounded mass. This can be grasped between the thumb and fingers and followed laterally past the cornu to the broad ligaments. If the tubes and ovaries are enlarged they may be found lying posterior to the uterus in Douglas's pouch instead of laterally. Hysterectomy (abdominal). — The uterus is to be drawn to one side and the posterior portion of the broad ligament is grasped out toward the pelvic wall. As the ovarian artery and veins run along the top of the broad ligament, a ligature is passed through it below them, but posterior or above the round ligament. A clamp may be placed on the side toward the uterus to prevent bleeding from the other side. The ligament is then divided between the ligature and clamp ; sometimes the ovaries are allowed to remain, but usually they are removed with the uterus. A ligature is then placed around the round ligament and it is divided ; often the round ligament is included in the first ligature. The incisions in the broad ligament are then carried through the peritoneum around the front of the uterus at the vesicouterine junction and also posteriorly. The bladder being loosely attached can be separated by blunt dissection down to the level of the external os. A clamp close to the side of the cervix controls bleeding from the sides of the uterus, and by pushing away the connective tissue outwardly the uterine artery can be recognized, ligated, and divided. The ureter lies below and behind i to 2 cm. (}4 to ^ in.) distant from the cervix. The cervix is then detached from the vagina, and the bleeding from the small vaginal vessels controlled tirst by clamps and then by sutures. Oophorectomy. — In removing ovarian tumors any adhesions present are first loosened, and then the tumor raised up and its pedicle ligated. The Fallopian tube is usually adherent to and removed along with the tumor. The pedicle is formed by the utero-ovarian ligament on the inside and the infundibulopelvic on the outside ; also the Fallopian tube and part of the broad ligament and branches or trunks of the ovarian artery and veins. As the ovarian vessels run horizontally, if the ligature is not placed low they may not be included, but only the branches which come off from them and proceed to the tumor. Salpingectomy. — In removal of the Fallopian tubes for purulent or other conditions, adhesions are frequently encountered owing to previous inflammation. To remove such a tumor it is better usually to do it by sight rather than by touch alone. If the patient is placed in the Trendelenburg (elevated pelvis) posture the intestines fall out of the pelvis and are kept back by gauze pads. Any coils which are stuck fast to the adjacent organs can then be carefully dissected and peeled loose and the tumor exposed. It will be found either posteriorly in Douglas's pouch, or laterally between the uterus and side of the pelvis, pushing the former toward the opposite side. The distended, enlarged tube with the ovary adherent to it can then be isolated by inserting the finger between it and the pehic wall, beginning at the posterior edge of the broad ligament and following it around posteriorly, loosening it from the rectum and Douglas's pouch until the uterus is reached. The finger is then passed beneath the tumor and it is peeled off the pelvic floor, it can then be raised up and its base ligated much like the pedicle of an ovarian tumor. If this is carefully done the parietal peritoneum will not be broken through and there will be little or no bleeding. Tumors of the Broad Ligament (intraligamentary tumors). — Certain tumors originating either from the structures of the broad ligament or ovary, c side of the uterus, grow between the layers of the broad ligament. Parovarian cysts arising from the remains of the Wolffian body are of this character. These intraligamentary cysts are retroperitoneal. The Fallopian tube is spread over and adherent to their upper surface. As they grow down they come in contact with the ureter, which becomes adherent to the bottom and sides of the growth. The liability of injury to the ureter is the greatest danger in these cases, and can only be escaped by searching for, recognizing, and avoiding it. These growths are exposed by splitting the peritoneum covering them and then shelling them out. At times they are large and formidable and extremely difficult to remove. Extra-Uterine Pregnancy. — The most dangerous factor in operating for extra-uterine pregnancy is hemorrhage. The tumor is usually tubal in position. The bleeding comes from the sac, therefore loosening and isolating it should be done with the greatest care to avoid rupturing it. If already ruptured the blood is to be rapidlv sponged out, the uterus recognized and grasped with the hand, which is then slid outward until the ruptured tumor is felt and drawn up. The blood comes to the tumor from the ovarian artery and uterine artery. To control the former a clamp is placed on the broad ligament close to the pelvic wall. To control the latter a clamp is placed low dow^i on the broad ligament close to the uterus. The active bleeding then ceases. thrqugh the vagina when, as is the case in multiparce, it is lax and capacious. The cervix is grasped and drawn down to the vulva and the mucous membrane incised in the anterior fornix and posteriorly close to the uterine tissue. The bladder is pushed up and separated from the cervix by dry dissection with occasional snipping of fibrous bands by scissors until the peritoneum at the level of the internal os is reached. The peritoneum, which from this point up is adherent to the uterus, is opened and divided to the broad ligaments on each side. Douglas's sac is next opened posterior to the cervix and close to it, and the opening enlarged with the finger to the broad ligaments. A clamp is now placed on each broad ligament low down to control the uterine arteries. By hooking the finger above the fundus it can be brought back and down and out, the ovaries usually coming with it. The remaining portion of the broad ligaments is then either clamped or tied to control the ovarian arteries. Some operators use clamps alone, others use ligatures. \'aginal branches which bleed are grasped with haemostats and ligated. The ureters, which lie 1.5 to 2 cm. (J^ to ^ in.) away from the cervix, are pushed outward when the opening in Douglas's sac is enlarged, and will be avoided by not placing the clamps too far away from the cervix. Laceration of the Cervix. — The cervix is made accessible for operation by grasping it with tenaculum forceps and drawing it down to the \-ul\-a. It is there held to one side, which renders the laceration easily accessible for excision and the introduction of sutures. Bleeding is controlled by the sutures. The /adia minora di\'ide anteriorly to form the prepuce abo\'e the clitoris and the frccnum on its lower surface. Posteriorly they fade away into a thin crescentic fold of mucous membrane called ih^foiirchette. The space between the labia minora is the vestibule. The vieatus or urethra is in the vestibule 2.5 cm. fi in.) behind the clitoris. It is surrounded by a ring of mucous membrane and in introducing the THE FEMALE EXTERNAL GENITALS. catheter it can be recognized by the sense of touch and so locaHzed. The openings of the para-iirethral ducts are just below and to the outside of the meatus. The vulvovaginal glands (of BarthoHn) empty on the inner side of the labia minora in the sulcus between them and the hymen. The openings of the ducts are just visible to the naked eye. The openings are about opposite the middle of the vaginal oririce on each side of the lower end of the vagina. The hymen partly occludes the lower end of the vagina across its posterior portion. The caruncidce hynie?iales are the remains of the ruptured hymen. The fossa tiavicularis is the space between the hymen and the fourchette. — The external genitals are well supplied with veins, and in pregnancy or pelvic growths they may become enlarged and varicose, especially over the labia majora. The fourchette and perineum frequently become ruptured in deli^'ery, the tear, if complete, going into the rectum. The meatus is sometimes the seat of a papillo-angiomatous growth called urethral caruncle. It is treated by removal. The vulvovaginal glands are the seat of cysts and abscesses. They appear as swellings alongside the posterior portion of the vaginal opening. The former are to be carefullv and completely e.xcised and the latter opened and packed. The vulvar slit is anteroposterior, the vagina forms a transverse slit and the hymen is placed at the point of transition. In making a vaginal examination (dorsal decubitus) the index finger is to be held A-ertically until the vestibule is entered. It then is passed horizontally into the \'agina and turned palmar surface Cystocele. — As a result of the relaxation following childbirth the bladder may prolapse through the vaginal orifice. When the uterus prolapses it also drags the bladder down with it. It is to be recognized by passing a sound through the urethra into it. It is treated by excising the mucous membrane co\-ering the cystocele and sewing the sides of the wound together, thus crowding the mucous lining of the bladder up into position (Fig. 466). perinei muscles from each side and the bulbocavernosus muscles from the front. The ischiocavernosus muscles lie along the rami of the pubes. These superficial muscles are reinforced by the deep transverse perinei muscle, which comes from the ramus of the ischium on the side to insert by its anterior fibres around the urethra (compressor urethr^e), its middle fibres into the vaginal wall, and its posterior fibres at the central point of the perineum. Also the levator ani muscle inserts into the lower end of the vagina anteriorly, then into the central point of the perineum, next into the lower end of the rectum, and finally into the coccyx. The deep layer of the superficial fascia (Colics' s fascia) and the triangular ligament being pierced by the vagina are not so marked as in the male — between them lie the ischiocavernosus, bulbocavernosus, and superficial transverse perinei muscles (Fig. 467). Rupture or Laceration of the Perineum. — When the tear goes only part way through the perineum it is called an incomplete laceration ; when it goes through into the rectum it is a complete tear. In an incomplete tear the bulbocavernosus muscles (called also sphincter vaginae) are separated behind and consequently their function of holding the labia majora together is lost and the vulva gapes. In a complete tear all the muscles helping to form the perineum are divided: they are the bulbocavernosus, the superficial and deep transverse perinei, and the levator ani and external sphincter ani muscles. They draw the sides of the wound apart, sometimes forming a dimple on each side, and thus enlarge the vaginal outlet and allow the anterior wall of the rectum as well as the posterior wall of the bladder to prolapse (Fig. 468). higher up than the lower end of the labium minus on one side and carrying it down and then up to a corresponding point on the opposite side. From the extremities of this incision two more are made extending 2.5 to 5 cm. (i to 2 in.) up the vagina and meeting in the median line. Emmet carried the denudation up each lateral sulcus. The mucous membrane so marked out is then dissected away; to close the wound some operators introduce and bring out the stitches all on the skin surface, while others introduce and tie half of them on the vaginal surface and the other half on the skin surface. The needle is to be carried well out toward the rami of the ischium so as to include a large mass of tissue. before the perineal tissues are approximated. Fig. 468. — Rupture of the perineum. The vulva gapes, showing the rectum bulging forward; the two dimples, one on each side of the anus, are caused by the retracted muscles. Penis. — The penis is composed of the two corpora cavernosa attached posteriorly to the rami of the ischia and pubes and terminating in blunt ends anteriorly, and the corpus spongiosum, commencing at the bulb, at the central point of the perineum posteriorly, and ending in the glans anteriorly. The glans is the extended corpus spongiosum and covers the ends of the corpora cavernosa. Its extended rim is called the corona glandis and the groove immediately behind, the neck, or colhwi glandis. In the centre of each corporus cavernosum runs an artery (Fig. 469). The skin is thin, loose, free from hair except at the root, and has beneath it some fibres of the dartos. It projects over the glans, forming the prepiice and is attached at the neck or collum glandis and underneath as far forward as the urethra, forming ^^frcsnum. The connective tissue beneath the skin is loose and free from fat. A fibrous sheath (Buck's fascia) surrounds the corpora cavernosa and corpus spongiosum and binds the three together. It is continuous posteriorly with the suspensory ligament and the deep layer of the superficial fascia (Colics' s fascia). Anteriorly it ends at the coUum glandis. The corpora cavernosa and corpus spongiosum have each a separate fibrous sheath which separates the two corpora cavernosa forming the septum pcctiniforvie: it is incomplete anteriorly, allowing the blood of the two corpora cavernosa to mingle. The separate sheath of the corpus spongiosum is not as marked as those of the corpora cavernosa. The single dorsal vein of the penis runs in the median line with an artery to each side and the dorsal nerves still farther out. They all lie between the fascial covering of the corpora cavernosa beneath and the fibrous sheath above. The lymphatics of the prepuce and skin drain into the inguinal nodes, those of the glans empty into the nodes in and just above (inside the abdomen) the crural canal; one radicle enters through the inguinal canal running posterior to the cord. As the lymphatic radicles anastomose at the root of the penis a lesion on one side of the organ may inx-olve the lymphatic nodes in the opposite inguinal region. Practical Considerations. — The opening of the prepuce is often constricted, so that the glans cannot be uncovered. This condition is c?\\^<\ phimosis. A certain amount is normal in young children. At times the prepuce becomes adherent to the glans but it can usually be separated by a blunt instrument without cutting. When the sulcus is reached an accumulation of smegma is seen. This is produced by the subaceous glands of the corona and coUum glandis and under surface of the prepuce. In performing circjimcision the prepuce should not be drawn too far forward or too much of the skin and not enough of the mucous surface will be removed; a common mistake. It is sufficient to remove the skin and mucous membrane two-thirds of the way back to the sulcus and then bring the ends of the incision gradually down and forward to meet at the lower angle of the meatus (Fig. 470) . By doing this the fraenum is not cut and troublesome bleeding from the little artery it contains is avoided. The laxity _ of the skin, especially of the prepuce, favors stricts the veins and the part beyond the constriction swells rapidly. This is called paraphimosis. To relieve it an incision is made through the skin directly across the constricting band and the prepuce can then be pulled forward over the glans. not invade the glans because the sheath stops at the collum glandis. Fracture or rupture of the corpora cavernosa may occur from violence. The extravasated blood is absorbed and the laceration heals with a scar. In erection this part does not expand, hence deformity and distortion with interference of function may result. Chordee. — When the urethra is inflamed the exudate may involve the corpus spongiosum surrounding it and prevent it from expanding. In erection the organ assumes a downward curve, a condition designated as chordee. It disappears with the subsidence of the inflammation. Amputation of the Penis. — The penis is frequently amputated for carcinoma, which disease is favored in the aged by the irritation resulting from a long-existing phimosis. In operating two things are to be guarded against, bleeding and subsequent contraction of the meatus. Bleeding may come from the dorsal arteries or the artery which runs in the middle of each corpus cavernosum. They can first be controlled by a circular rubber band and then later readily ligated. To prevent contraction of the new meatus three methods are available: ( i) A long dorsal and short under flap may be cut and the urethra dissected out from the under flap and allowed to project beyond the cut corpora cavernosa. The long dorsal flap is brought down, pierced, and the urethra drawn through. It is then slit up and sewed on each side. A few sutures are then used to unite the upper and lower flaps below the urethra. (2) Two lateral flaps may be made and the split urethra sewed in the line of union between the two flaps. (3) {V^x\\.^x' 'i, University Medical Magazine, ]2XiW?iXY,\%C)^.') The arteries being tied, the two outer edges of the corpora cavernosa are brought together in the median Hne with three catgut sutures. The urethra is then sHt up in three places, one below and two above; the three square flaps so formed are then turned back and their corners cut off. This makes three small triangular flaps which when spread out form one large triangle. The skin is then sutured accurately to the edges of this triangle and no raw surface is left (Fig. 471). Scrotum, Testicles, and Spermatic Cord. — The SCROTUM is the bag in which the testicles are contained. It consists of skin and dartos. The remaining tissues covering the testicles are derived from the layers of the abdominal wall and belong properly to them. The ski?z is thin, loose, wrinkled, and contains sebaceous glands which frequently become occluded, forming small tense cystic tumors. The dartos is composed of loose connective tissue and unstrlped muscular fibres. It is intimately connected with the skin but moves freely on the parts beneath. It is continuous with the general superficial fascia and with its deep layer or Scarpa's fascia of the abdomen and Colles' s fascia of the perineum. It dips between the testicles, forming an incomplete septum (Fig. 472). penis. Mucous membrane of urethra everted, cut in triangular form and sewed to the skin to avoid cicatrical contraction. (Author's metiiod.) if primary union is desired particular care must be taken to approximate accurately the skin edges and prevent their inversion. The raising of the testicles is done by the cremaster muscle and not by the dartos except incidentally as the scrotum contracts. The scrotum is supplied by blood through the perineal branches of the internal pudic artery, and by the external pudic. On account of the looseness of the skin attachment, oedema and extravasation of blood and urine may be very extensive and violent. They readily impair the blood circulation and gangrene not infrequently results. It is for this reason that urinary infihrations are to be at once incised, and in operations the greatest care is exercised to stop every bleeding vessel. Infec tion of this region is particularly troublesome and a strict technic is necessary in operating to avoid it. In some cases of varicocele with pendulous scrotum a portion of the scrotum is excised in order to support the testicles. Descent of the Testes. — The testis is covered by peritoneum, which is prolonged at its upper and lower ends. The lower reaches down to the internal ring and later contains fibrous and muscular tissue and passes through the inguinal canal to the lower part of the scrotum: it is called the gubcrnaculuui testis. It reaches its highest development in the sixth month and its remains attach the testicle to the lower part of the scrotum as the ligament of the scrotum. As the testicle descends, the upper peritoneal band covers the spermatic vessels from the region of the kidney down. The lower portion of the gubernaculum sends branches to the regions of the pubes, perineum, and saphenous opening. The testicle is preceded in its descent through the inguinal canal by a fold of peritoneum — the vaginal process — which forms the tunica vaginalis over the testicle, the part above atrophying. Practical Applications. — The testicle may be arrested in some portion of its course, forming an undescended testicle, or it may be displaced, as has been suggested, by an abnormal development of one of the subsidiary bands of the gubernaculum. Hence it may be found, not in the scrotum, but in the perineum, in the femoral region, or in the pubic region. It may go through the femoral canal instead of the inguinal. If it is undescended it may be arrested in the abdominal cavity, in the inguinal canal, or at the external ring. The vaginal process may not entirely close, so that the peritoneal fluid passes down to the tunica vaginalis covering the testicle; this is called a congenital hydrocele. If the opening is large enough for intestine to enter, it forms a congenital hernia (see page 383). If the opening is closed above, usually at the external ring, and fluid accumulates in the tunica vaginalis it forms an infantile hydrocele. If a portion of the vaginal process persists somewhere along the spermatic cord between the internal ring and top of the testis it forms a cyst and is called an encysted hydrocele of the cord. The vaginal process closes at its upper portion just before birth and in those cases which are patulous after birth (congenital hernia and hydrocele) there is a tendency to spontaneous closure, hence operative measures are usually deferred. The vaginal process also descends into the inguinal canal in the female and a hydrocele of it is called a hydrocele of the canal of Nuck. Size, Position, etc. — The normal testicles are 4 cm. (i^4 in.) long, 2.5 cm, (i in.) wide, and 2 cm. (f in.) thick. They are firm to the touch. If larger they are either hypertrophied or diseased. If hypertrophied their consistence is not materially altered, if diseased they are usually harder. If smaller they are usually atrophied and besides the lessening of size are also softer and flabby in consistency. They lie attached at the inner posterior portion of the scrotum and their long axis points upward, slightly forward, and outward. In all cases of hernia and hydrocele the testicle is to be felt for at the inner posterior aspect of the swelling. In rare instances the testicle is placed anteriorly instead of posteriorly and is liable to be wounded in introducing a trocar into the tunica vaginalis to empty a hydrocele. To avoid this accident the position of the testicle can be determined not only by touch but also by seeing the outline of the testicle by means of a light placed on the opposite side of the scrotum. As the testicle is almost always low down the puncture should be made higher up and preferably on the outer side. Epididymis. — The vas deferens descends to the lower end of the testicle and becoming much convoluted forms the globus minor or tail, thence ascends, forming the body, and finally at the top, receiving the efferent ducts, forms the globus major or head. Between the body of the epididymis and testis is a pocket or depression called the digital fossa. Attached to the upper end of the testis is a small flat body in front of the globus major and attached to the globus major itself is a small cystic pedunculated growth. Both are known as the hydatids of Morgagni, and the former is the remains of the duct of Miiller, while the latter is derived from the Wolffian bodv. Practical Application. — Inflammation of the testis proper is called orchitis; of the epididymis, epididymitis. When the testicle as a whole is enlarged, if it is due to syphilis or new growth, the testis itself is mainly affected and it is then called sarcocele. Inflammations, the result of injury, may produce a true orchitis, but when arising from infections they involve the vas deferens and epididymis and produce an epididymitis. This is the case in gonorrhoea and tubercle, and to a less extent in mumps. An enlarged epididymis can be outlined by careful palpation as being distinct from the testis proper. Advanced tubercle may invade the testis subsequently. Cystic disease is fairly frequent ; it involves the epididymis, especially the globus major. The cysts may be very numerous and may spring either from the ducts of the globus major or from the hydatids of Morgagni. Coverings of the Testicle. — The tunica \-aginalis comes from the peritoneum, the tunica albuginea is the continuation of the transversalis fascia (infundibuliform fascia); it is strong, dense, and inelastic. Over this are a few cremasteric fibres from the internal oblique and the intercolumnar fascia from the external oblique. The dartos is continuous with the fascia of Scarpa of the abdomen. Application. — The tunica \-aginalis being a closed sac may become distended with serum, forming a hydrocele. The precautions to be taken in tapping it have been alluded to above. It is treated radically by excising the parietal layer and lea\-ing the visceral layer co\"ering the testicle and epididymis. The questions of hemorrhage and skin inversion have also been discussed. Inflammation causes intense pain on account of the unyielding character of the tunica albuginea. To relieve it multiple fine punctures are sometimes made. Abscess (tuberculous) of the testicle opens the tunica albuginea and the testicular tissue protrudes, forming a hernia testis. Such testicles are often excised, but if not the hernia eventually shrinks and reduces itself (Holden). Spermatic Cord. — The left spermatic cord is longer than the right, hence the left testicle hangs lo^\■er. The cord is composed of the vas deferens with its artery, a branch of the superior vesical, and veins; the spermatic arter)^ with its veins; the cremasteric arter}-; and the layers derived from the abdominal wall (the same as possessed by the testicle). It also possesses ner\-es, the genital branch of the genitocrural, and branches of the sympathetic, and lymphatics. The vas deferens is a small, round, hard cord lying posteriorly. It can be seen when the elements of the cord are separated and can be distinctly felt even through the scrotum. The deferential artery accompanies and lies on the cord. The deferential veins go with the arterj'. They unite and form three or four trunks (pampiniform plexus) which pass through the inguinal canal to join and form at the internal ring one large vein, the spermatic, which accompanies the spermatic artery; the right empties into the vena cava, while the left empties into the left renal vein. They possess but few vah-es, which are imperfect. The spermatic artery, from the aorta, descends in front of the vas deferens and is accompanied by the pampiniform plexus of veins. It lies in the plexus with most of the veins in front of it. These vessels lie in loose, fattv connective tissue derived from the subperitoneal tissue along with the atrophied remains of the peritoneum (ligament of Cloquet). These structures are covered by the sheath of the cord, composed ( i ) of the transversalis fascia (infundibuliform fascia), (2) cremasteric fibres and fascia from the internal oblique, and (3) intercolumnar fascia from the external oblique. Applicatio7i. — The cord is involved in operations for varicocele, hernia, and castration. In varicocele after the skin incision is made a second incision is required to open the sheath of the cord. This having been done the pampiniform plexus of veins, which are the ones enlarged (varicose) in varicocele, come into view. As many of these as desired are then drawn out, ligated at both ends, and removed. In doing this the spermatic artery may likewise be tied. The circulation is afterwards carried on by the artery and veins of the vas, the cremasteric artery being in the sheath externally. It is wise not to remove all of the enlarged veins. The vas deferens is recognized posteriorly both by sight and touch and is not to be disturbed. In hernia the vas deferens sticks close to the sac, on the posterior and inner side. It must be sought for and carefullv isolated. In castration the testicle is so movable that it can be pushed up into the inguinal region and the incision through the skin for its removal made in that locality. If done for malignant disease a large portion of the vas is removed. This can be done by incising up to the internal ring and drawing tlie vas out after freeing it of any restraining fibrous bands. All bleeding vessels are to be ligated and the cord securely held. If the cord slips before all the vessels are secured, the stump may retract in the abdomen and dangerous bleeding result before it can again be secured and the vessels ligated. The male urethra is variable in length, as it can be stretched, therefore only average measurements can be given. Its length is 20 cm. (8 in.) in the adult, 8 to 10 cm. at 5 years, and 10 to 12 cm. at puberty. Of this, 3 cm., (i^ in.) is prostatic, 0.5 cm. ( \ in. ) being in the bladder wall ; i cm. ( \| in. ) is membranous; 16 cm. (a little over 6 in. ) is penile. Its calibre varies, being narrowest at the meatus and next narrowest at the membranous portion. The internal meatus is a little larger than the membranous portion. The meatus admits a No. 24 French sound (often larger), the membranous portion a 26 to 28. The prostatic portion is the largest, admitting a No. 32 sound. The bulbous is almost or quite as large, admitting a 30 to 32. Therefore a sound which passes the meatus should find no further obstruction. The fossa navicularis just beyond the meatus is larger than the urethra beyond (Fig. 473). Distensibility. — The meatus and membranous portions are the least distensible. The former is fibrous in character and will not stretch. In the membranous portion the support of the superficial and deep layers of the triangular ligament prevent dilatation. The prostatic is the most dilatable portion and the bulbous urethra next. Relations. — The internal urethral meatus lies about 6. 25 cm. {2\ in.) from the surface just behind the middle of the symphysis, if the body is in a vertical position. The membranous portion pierces the triangular ligament, 2.5 cm. (i in. ) or a little less below the subpubic ligament. The urethra then rises slightly, o. 5 cm. (i in.), and finally drops to the meatus. The subpubic curve of the urethra has a radius of about 5 cm. (2 in.) and urethral instruments are made with approximately this curvature, though nous urethra can be palpated at the apex of the prostate by the finger in the rectum. Structure. — The urethra is composed of an external laver of erectile tissue covering a muscular layer which is continuous with that of the prostate and bladder. Beneath the muscular layer is the submucous, rich in blood-vessels, on which is laid the mucous layer. This latter is covered with flat, pavement epithelium in the fossa navicularis, and columnar epithelium beyond. The urethra contains small mucous glands opening on its surface— ^/a/z^^ of Littre — and small pockets or recesses, called the lacimce of Morgagjii, into which the glands of Littre sometimes empty. The lacunae are mostly in three rows on the roof of the penile portion and open forward toward the meatus. A large one lacuna magna — opens in the posterior portion of the roof of the fossa na^-icularis, a couple of centimetres behind the meatus. The glands of Cowper open into the bulbous urethra just in front of the triangular ligament. The racemose glands of the prostate open into the sides of the floor of the prostatic urethra, and the ejaculatory ducts open near the middle line just in front of the urethral crest (verumontanumj, with the utricle (prostatic sinus) between. The mucous walls of the urethra are normally in contact, making a vertical slit at the external meatus, a transverse one in the penile portion, horseshoe shape in the prostate, and again transverse just before the bladder is reached. Urethral Muscles. — There are two sets of muscles in connection with the urethra; one set might be said to aid in expelling the urine and the other in retaining it. The expulsors are the longitudinal and circular fibres surrounding the urethra just outside the mucous membrane and the accelerator urhicB or bidbocavernosus ?nuscle. The sphincters are the compressor tu-ethrcB or external sphincter muscle, and the internal sphincter at the neck of the bladder, composed of fibres continued from the bladder and prostate. The portion of these fibres surrounding the internal meatus just beneath the mucous membrane is called the anmihis 2Lrethralis. It has been supposed that if the bladder becomes distended the internal sphincter involuntarily relaxes and allows the urine to enter the prostatic urethra, and it is then stopped by the voluntary contraction of the external sphincter, which is the true sphincter. Leedham Green {Brit. Med. fojtr., August, 1906) claims that the internal sphincter holds tight in the living subject e\en when the bladder is overdistended. Sections made of formalin-hardened bodies seem to support this view. Practical Applications. — A knowledge of both the length and calibre of the urethra is essential in the use of both catheters and bougies or sounds. If urine begins to flow when a catheter is introduced 20 cm. we know the urethra is of normal length. Urine may flow when the bladder is distended as soon as the catheter passes the membranous portion, about 17 cm. (63/^ in.) from the meatus. In hypertrophy of the prostate the prostatic urethra is much increased in length and it may be impossible to reach the bladder by an ordinary catheter. It may require one 25 or 30 cm. (10 to 12 in.) long. The position of a stricture is located by its distance from the meatus. If a sound is stopped by a stricture inside of 15 cm. (6 in.) from the meatus we know it is anterior to the triangular ligament. Strictures are most frequent where the subpubic curve is lowest, viz. , at the bulbomembranous region. They are then called deep strictures. They are next most frequent toward the anterior portion, while strictures of the prostatic portion are almost unknown. Passage of Sounds and Catheters, — In passing a catheter or sound its beak should be kept applied to the roof of the urethra, otherwise its point will catch in the dilated bulbous portion and strike on the triangular ligament below the opening for the urethra. To aid the beak to follow the subpubic curve the handle is depressed. In difficult cases the index finger of the opposite hand is introduced in the rectum and the beak is felt at the membranous portion a short distance in front of the apex of the prostate and guided upward into the bladder (Fig. 474). If the penis is grasped near the glans and drawn up the instrument, the urethra may so stretch that the sound will not reach to the bladder. To avoid this it should be grasped lower down toward the scrotum. The urethra is so flexible and loose that straight instruments, such as cystoscopes, can readily be passed by skilful hands. In hypertrophy of the prostate, long instruments, with big curves if of metal, are essential. Many rubber catheters are too short for this purpose. In passing small, filiform bougies they are to be directed at first toward the floor of the urethra to avoid the lacunae on the roof. If they do catch they are allowed to remain and so prevent the ones subsequently introduced catching in the same place. The vascular net- work in the submucous tissue bleeds readily and the skill evinced by the surgeon in passing urethral instruments is in inverse ratio to the amount of bleeding produced. Otis claimed that a penis 3 in. in circumference had a normal urethra admitting a No. 30, French scale, sound; 2,% '"• ^'o- S^; SH ^^- No. 34; 334; in. No. 36, and 4 in. No. 38. White and Martin state that a 3 in. circumference admits a No. 26 to No. 28; 31^ in. Nos. 28 to 30; 3^4 in. Nos. 30 to 32; 3^ in. Nos. 32 to 34; and a 4 in. Nos. 34 to 36. We agree with the latter, and often the meatus though normal in appearance must be incised to admit the above sizes. The distensibility of the urethra is such, especially in its deeper portions, that after incision of the meatus very large sounds can be introduced. For this reason urethrotomes should not cut to the full size. Teevan's urethrotome only cuts up to 22 French and the additional size is obtained by stretching with sounds. This instrument in one case was made to cut to 26 French but death followed from hemorrhage and a return was made to No. 22. It cuts on the roof, and the dorsal artery of the penis or the artery to the bulb was probably divided. To avoid hemorrhage, deep strictures are treated by dilatation or external urethrotomy and penile strictures only are cut internally. Keegan has shown that the calibre of the urethra in small children is sufhcient to allow the use of the lithotrite and so avoid a cutting operation. Spasmodic stricture results from contraction of the urethral muscles due to some irritation. This irritation may be from the urine, from organic stricture, fissure of the anus, hemorrhoids, etc. It causes retention of urine, which can be relieved by passing a full-sized catheter, or by hot baths, etc. Notice the firmness with which the urethra grasps a sound as it is withdrawn. Traumatic Stricture. — This is usually located in the bulbous portion, just in front of the triangular ligament. The urethra is compressed between the pubic bone and the vulnerating body. It is treated by passing in a full-sized catheter either with or without the aid of a perineal incision. THE MALE PERINEUM. The name perineum in its broad sense is applied to the structures of the outlet of the pelvis, superficial to the le\'ator ani muscle. In its restricted anatomical sense it is applied to the subpubic triangle as far back as a line joining the anterior portions of the tuberosities. In its clinical sense it is the space between the anus and scrotum in the male and anus and vulva in the female. Bony Landmarks. — On examining the pelvic outlet the symphysis pubis is seen anteriorly with the descending rami of the pubes and ascending rami of the ischia on the sides, leading to the tuberosities. Posteriorly is seen the coccyx, with the spines of the ischia on each side comparatively close to it. The greater sacrosciatic ligament runs from the sacrum to the tuberosity of the ischium, the lesser from the sacrum to the spine of the ischium. Taken together a diamond-shaped space is formed. In the female the pubic arch is wider, the tuberosities further apart, the spines of the ischia do not project so markedly inward, and the coccyx is more movable. Perineal and Ischiorectal Regions. — A line drawn from the anterior portion of one tuberosity to that of the opposite side passes 1.25 cm. ( J^ in.) in front of the anus, and divides the outlet into the urogenital triangle or perineum in front, and the anal triangle or ischiorectal region behind. The central point of the perineum is in the median line 2 cm. f j.^ in.) in front of the anus; it marks the posterior edge of the triangular ligament in the median line, and is the point of junction of the anteroposterior and transverse muscles. Perineal Fascias. — There are four perineal fascias, \iz. : (i) the superficial la/er of the superficial fascia ; (2) the deep layer of the superficial fascia, called also Colles's fascia ; (3) the superficial layer of the deep fascia, or triangular ligament ; and (4) the deep layer of the triangular ligament or pehic fascia (Fig. 475). The superficial layer of the superficial fascia is the subcutaneous fatt}' tissue, and is continuous with that of the surrounding parts and the dartos. When thick it makes operations on the deeper structures more difiicult and sometimes impossible. The deep layer of the superficial fascia or Colles' s fascia is the fibrous under surface of the fatt}* superficial layer. Posteriorly it unites with the posterior edge of the triangular ligament; laterally it is attached to the ischiopubic rami; and anteriorlv it is continuous with the under surface of the dartos of the scrotum, passes fon\-ard to form the suspensory ligament and fibrous sheath (Buck's fascia) of the penis, covers the spermatic cord, and is continuous with Scarpa's fascia (deep laver of the superficial fascia) of the abdomen. The anterior layer of the triangidar ligament is a firm fibrous membrane stretching from one tuberosity to the other, and attached to the ischiopubic rami on the sides fonvard to the pubic arch. Between its upper edge and the symphysis runs the dorsal vein of the penis, the dorsal arter\- and ner\-e piercing it a litde lower and to the outer side; 2.5 cm. (i in.) below the symphysis is the urethral opening v.ith the opening for Cowper's ducts close to it below, and those for the vessels to the bulb close to it above. The superficial perineal vessels and ner\"es pierce its posterior edge. The posterior edge of the triangular ligament blends with the posterior edge of the deep layer of the superficial fascia (Colles). The deep layer of the triangular ligament is a continuation downward of the pelvic fascia. It begins above on the inside of the pehis, co\ering the obturator muscle as the obturator fascia ; it then passes onto the levator ani muscles as the recto-\-esical fascia. As the levator ani muscles do not meet in front, the gap between them is filled in at the median line below or posteriorly by the termination of the longitudinal fibres of the rectum ( prerectalis muscles of Henle, recto-urethralis of Roux, Kalischer, Holl, Proust, and others — see page 438, Rectum j, at the sides by the deep transverse perinei and compressor urethrae muscles, and anteriorly by the continuation of the rectovesical fascia. From the deep transverse perinei muscles forward the rectovesical fascia is called the deep layer of the triangular ligament rFig. 476). Perineal Spaces. — There are two perineal spaces, one superficial space between the triangular ligament (superficial layer) and the deep layer of the superficial fascia (CoUes's fascia), and the other, the deep perineal space, between the superficial layer of the triangular ligament and its deep layer. Superficial Perineal Space. — The superficial space has on each side the crura of the penis attached to the ischiopubic rami and co\'ered by the ischiocavernosus (erector penis) muscles. In the median line anteriorly lies the urethra with its erectile tissue covered by the bulbocavernosus (accelerator urinae) muscle. The posterior portion lying on the triangular ligament is called the bulb, and reaches back to the central point of the perineum. From the central point the superficial transverse perineal muscles pass outward and somewhat backward to the rami of 'the ischia, and the sphincter ani passes back to the coccyx. ^\\(t internal pudic artery comes forward from the spine of the ischium through Alcock's canal on the outer wall of the ischiorectal fossa, 4 cm. ( i ^2 in. ) above the lower edge of the tuberosity ; when it reaches the posterior edge of the triangular ligament it gives off the superficial perineal arterv, which p;erces it and enters the superficial perineal space, where it gives off the small transverse perineal artery, and then continues anteriorly to the base of the scrotum. The pudic nerve sends two branches forward in this space, the posterior or internal superficial perineal toward the middle, and the anterior or external along the outer side of the space accompanying the superficial perineal artery forward to the scrotum. The Deep Perineal Space. — This lies between the anterior and posterior layers of the triangular ligament. It contains the compressor urethrae (external vesical sphincter) muscle surrounding the urethra. Embedded in this muscle is Couper's gland. Its duct, 2 cm. (\|- in. ) long, pierces the anterior layer of the triangular ligament to empty into the bulbous urethra. Immediately behind the compressor urethrae is the deep transverse perinei muscle passing across from one ischiopubic ramus through the central point of the perineum to the other. Running along ths outer side of the space is the continuation of the internal pudic artery. It gives ofi the artery to the bulb about 3 cm.^ (ij{ in. ) in front of the^nus, and then about 1.25 cm. {)4 in.) below the subpubic ligament pierces the anteriorlayer of the triangular ligament and divides into the artery to the corpus cavernosum and artery to the dorsum of the penis ; it is accompanied by the pudic nerve, which divides in like manner. Posteriorly this space is open, not being closed by any fascia except that lining the under or superficial surface of the levator ani muscle in the ischiorectal fossa. In the mid-line the continuation of the longitudinal fibres of the rectum called the prerectal or recto-urethralis muscle blend with the fibres of the deep transverse perineal muscle. Practical Application. — The perineum is involved in extravasations of blood and urine in cases of rupture of the urethra ; also in operations on the deep urethra and bladder for the retention of urine from stricture ; also in operations for vesical calculus, enlarged prostate, and disease of the seminal vesicles. Extravasation of Uj'ine and Blood. — Urinary extravasation results most often from stricture and occurs almost always in front of the anterior layer of the triangular ligament. The urine enters the superficial perineal space and is confined superficially by Colles's fascia and beneath by the triangular ligament. It is prevented from going back into the ischiorectal space by the union of Colles's fascia and the triangular ligament posterior to the superficial transverse perineal muscles ; it is prevented from extending laterally by the attachment of Colles's fascia to the ischiopubic rami ; hence it works its way forward, distends the scrotum, and follows the spermatic cord up over the crest of the pubis between the spine of the pubis and the median line. Reaching the surface of the abdomen it is prevented from descending on the thigh by the attachment of the deep layer of the superficial fascia (Scarpa's fascia) just below Poupart's ligament, so it flows laterally and makes a collection in the flank of each side above the iliac crests. The septum in the median line of the abdomen, perineum, and scrotum hinders but does not prevent the passage of the urine from one side to the other. In treating it, numerous free incisions are made down to the deep fascia. Rupture of the Urethra. — This is produced by falling astride a hard object and jamming the urethra against the subpubic arch, or it results from stricture. The rupture almost always involves the urethra just in front of the triangular ligament and sometimes a part of the membranous urethra. The superficial perineal space becomes infiltrated with blood, and if urine is passed it follows the blood, collecting between Colles's fascia and the triangular ligament. If the membranous urethra is ruptured the blood and especially the urine may escape into the deep perineal space between the layers of the triangular ligament. It may break or leak through the anterior layer and enter the superficial perineal space ; it may work backward into the ischiorectal regions ; it may work up and back between the prostate and rectum or breaking through the deep layer of the triangular ligament it may work up and anterior behind the symphysis pubis, in the prevesical space (of Retzius) between the peritoneum and transversalis fascia (see Fig. 476). Ruptured urethra is treated by perineal section or by a retained catheter. Perineal Section and Median Lithotomy. — In these operations the bladder is entered through an incision in the median line into the bulbomembranous urethra. They are done to divide deep strictures, to allow the urine to escape in extravasation and rupture of the urethra, to remove foreign bodies and calculi from the bladder, and to remove enlargements of the prostate gland. The incision is to be made through the raphe in the median line ; ordinarily it does not begin farther forward than 3 cm. (15^ in. ) in front of the anus. As the central point of the perineum is 2 cm. in front of the anus the incision passes through it and divides the posterior fibres of the bulbocavernosus muscle but involves little if at all the erectile tissue of the bulb. There is little bleeding if the incision is kept in the median line. The urethra is entered about 2.5 cm. (i in.) from the surface, and the knife passed upward and back through the membranous and prostatic urethra into the bladder, a distance of 6. 25 to 7. 5 cm. (2 5^ to 3 in. ) from the surface. In fat people or those with enlarged prostates one may be unable to reach the interior of the bladder with the finger. The membranous and prostatic urethra is distensible, so that when the former is opened the finger can be introduced and pushed into the bladder. In children the urethra may be too small to permit the entrance of the finger and a blunt guide is introduced, along which forceps may be passed to extract any foreign body. In Cock' s operation for retention of urine the index finger of one hand is introduced through the rectum and its tip placed at the apex of the prostate. (For removal of enlarged prostate see page 450. ) Lateral Lithotomy. — The incision is begun to the left of the median line 3 cm. {_\% in.) in front of the anus and carried outward and back midway between the anus and tuberosity of the ischium. The knife is pushed steadily on until it enters the groove in the staf! and thence backward into the bladder. The artery to the bulb is to be avoided by not going more than 3 cm. in front of the anus. The rectum is to be avoided by having it empty, by hooking the staff in the urethra well up to the pubic arch, thus drawing the urethra up, and by inclining the knife obliquely outward. The internal pudic artery is to be avoided by keeping away from the ramus Jf the ischium. Too free an incision of the prostate is bad because urinary infiltration is liable to occur in the pelvic fascia, also an accessory pudic artery, which if present may run along the side of the prostate, may thus be wounded. Usually the bleeding is slight and comes from the division of the superficial transverse perineal and branches of the inferior hemorrhoidal arteries and the prostatic plexus of veins. (For Perineal Prostatectomy see page 450 and Seminal \'esicles page 452.) Anal Triangle and Ischiorectal Region. — The anal triangle is made by the superficial trans\-erse perineal muscles forming its base and the tip of the coccyx its apex. It contains the anal canal with the ischiorectal fossae on each side. The ischiorectal fossa is wedge-shaped, its base, extending between the tuberosity of the ischium and the anus, is about 2.5 cm. (i in.) in breadth, and its apex extends up 5 to 7.5 cm. (2 to 3 in.), to the junction of the levator ani and internal obturator muscles. Its inner wall is formed by the le\-ator ani and coccygeus muscles and its outer wall by the obturator internus muscle. Its deepest extreme posterior portion constitutes th.e posterior recess. This communicates superficially, beneath the coccygeal attachment of the external sphincter, with the fossa of the opposite side (see Fig. 475, page 473). The anterior recess (pubic, Waldeyer) runs forward between the prostate gland internally and the ischiopubic ramus externally ; the deep and superficial transverse perinei muscles and the deep layer of the triangular ligament are superficial to it. The internal pudic vessels and pudic ne^-ve lie on the internal obturator muscle and ramus of the ischium in a fibrous canal formed by the obturator fascia. It is called AlcocJc s canal 2ind is 4 cm. (1J2 in.) above the tuberosity. The inferior hemorrhoidal vessels and nerves enter the ischiorectal fossa at its posterior and outer side and run on the surface of the levator ani muscle toward the anus. The superficial perineal x^ssfAs and nerves enter the fossa anteriorly and immediately pierce the posterior edge of the superficial perineal (Colics' s) fascia to supply the structures between it and the superficial layer of the triangular ligament. Practical Application. — The principal aflection of the ischiorectal fossa is abscess. This is probably started by violence and infected from the rectum. It commonly tends to point through the skin or open into the rectum. On account of its tendency to burrow it is to be opened early. This is done by making an incision of ample size through the skin and then opening the abscess by blunt dissection in order to empty all pockets. Bleeding is usually slight because the vessels lie deep and escape being wounded. Should the abscess not break externally it may do so internally. If superficial it pierces the anal canal between the external and internal sphincters and makes an opening at about the white line. If it is very deep it may open into the ampulla of the rectum above the internal sphincter (see page 443)It is more common for pus to burrow down into the ischiorectal space through the levator ani than it is for it to burrow up from the ischiorectal fossa (Tuttle). Therefore in extensive ischiorectal abscesses communicating with the interior of the pelvis one should look for the origin of the trouble above. An abscess on one side is liable to be followed by one on the other and pus quite commonly crosses the median line posterior to the anus. On examining the back of a person standing upright a median furrow is seen (Fig. 477 ). In the bottom of this the tips of the spinous processes can be felt. If the back is bent these processes can be distinctly seen; they should form a straight line. The second cervical spine can be felt by deep pressure in a relaxed neck. The sixth is usually the hrst one visible and the seventh cervical and first dorsal are ^■ery prominent, often the latter the more so. The furrow ends abruptlv at the top of the sacrum. From this point down to near the top of the gluteal fold is a triangiclar space with its base above and apex downward. Its apex marks the third sacral spine, and just above this latter, opposite the second sacral spine, on each side can be felt the posterior superior iliac spines. The e7'ector spines (sacrolumbalis) muscles form elevations on each side of the furrow, most marked in the lumbar region. In muscular people the erector spinse is seen to consist of Xwo parts : an inner longissimus dorsi muscle, and an outer iliocostalis. Abo\-e, the projections of the scapulce are visible. If the arms are by the sides the posterior border of the scapula is parallel to the median line. The root of the spine of the scapula in a muscular person makes a depression. It is opposite the third dorsal spine or the body of the fourth thoracic vertebra, and marks the upper end of the fissure of the lungs. The spine of the scapula is subcutaneous and can be traced out to the acromion process. The lower angle of the scapula is opposite the upper border of the eighth rib; the upper angle covers the second rib but its tip is level with the tirst. In the lumbar region the erector spinae muscle forms a clearly marked prominence. The twelfth rib usually projects beyond its outer edge, which is marked by a depression separating it from the abdominal muscles in front. It is through this depression that operations on the kidney are performed (see page 428). The distance between the twelfth rib and crest of the ilium is usually 6.25 cm. {2% in.) but it mav be more and is often less. Just above the middle of the crest of the ilium is Petit" s triangle (page 394); and to the inner side of the lower third of the poste- rior edge of the scapula is another small triangle. Its upper side is formed by the trapezius, its lower by the latissimus dorsi, and its outer by the posterior edge of the scapula. As the lung is nearest the surface at this point it is often chosen for physical examination, puncture, etc. THE VERTEBRAL COLUMN. Normally the spinal column is composed of seven cervical, twelve dorsal, five lumbar, five sacral, and four to five coccygeal vertebrae. The sacral vertebrae tend to fuse together, forming a single bone, the sacrum. This fusion is complete at the twenty-fifth year. The coccygeal vertebrae join later, fusion occurring in middle life. Sometimes in ad\'anced age the coccyx and sacrum fuse together. The cervical vertebrae are almost always seven in number, but both the dorsal and lumbar vary much more frequently than is usually supposed. The occurrence of thirteen instead of twelve ribs on a side is not uncommon and I have seen skeletons with only eleven. A rudimentary cervical rib also occasionally occurs. The tips of the spinous processes of the cervical \'ertebrae, the first two dorsal, and last four lumbar, pass almost horizontally backward and are therefore nearly opposite the bodies of the vertebrae to which they are attached. The tips of the spines from the third to the last dorsal inclusive, however, are opposite the bodies of the next vertebrae below them, being inclined downward, while the tip of the first lumbar is about opposite the inter\-ertebral disk beneath. Curves. — At the third month of intra-uterine life there is only one large curve, convex posteriorly. At birth there are two curves, each convex posteriorly, a dorsal and sacral, probably to accommodate the thoracic and pelvic viscera; after the erect position is assumed the cervical and lumbar curves become established. The cervical passes into the dorsal curve at the middle of the second thoracic \-ertebra and the dorsal into the lumbar at the middle of the last thoracic vertebra. (Fig. 478). Laterally, there is a slight curve in the dorsal region with its convexity to the right, probably due to the increased use of the right hand. Movements. — Flexion and extension are free in the neck and lumbar region, rotation is slight in the cervical region, free in the upper portion of the dorsal, and gradually diminishes to be absent in the lumbar region. The weight of the head is borne on the condyles of the occiput, and a perpendicular let fall from the condyles passes through the points where the spinal curves pass one into the other and thence through the anterior edge of the promontory of the sacrum. Hence if one curve is altered by injury or disease it is of necessity accompanied by a corresponding change in the curve on the opposite side of the perpendicular line. The first is called the primary curve and the other the secondary one. In anteroposterior curvatures these curves are exaggerations of the normal curves but in lateral curvatures they are newly formed because there is, practically, Kyphosis. ^The vertebrae are supported one above another by two points of contact, a posterior one, formed by the articular processes, and an anterior one, formed by the bodies of the vertebrae separated by the intervertebral disks. Of these two supports, that afforded by the bodies and disks is the more important. The laminae and pedicles with their attached articular processes are frequendy fractured, but the shape of the vertebral column is but little altered; even after laminectomy the spine remains comparatively straight. When, however, the bodies of the vertebra are destroyed, as occurs in tuberculous disease and crushing injuries, the anterior portion of the spine collapses and the parts bend, the spines projecting backward forming a hump (Fig. 479). Thus the angular character of the deformity is explained by the method of construction of the spine. Besides this a7igidar kyphosis there is another form, due to general weakness. This is seen in rachitic children ; owing to a weakness of all the tissues the normal curves become increased and, as in young children, the normal spine has one long general curve with its convexity posteriorly, we find this curve greatly increased, forming a rachitic kyphosis. Lordosis. — When a child is born and for some time thereafter the spine possesses a slight dorsal and a pelvic curve. When it sits up and begins to hold its head erect and look around, the cervical curve develops. Still later when it begins Fig. 479. — Kyphosis or angular anteroposterior curvature, usually due to caries of the bodies of the vertebrae. vature of the spine. to walk the lumbar curve develops. An increase in the lumbar curve, or lordosis, is caused by general weakness as just described for rachitic kyphosis, or it results from some disease or injury interfering with the lower extremities and thus disturbing the centre of gravity. This occurs in congenital luxation of the hips (Fig. 4S0), in which the heads of the femurs are set too far back, and also in rachitic deformities of the lower extremities, hip disease, etc. Likewise, if the abdominal \'iscera are unduly prominent, the thoracic region is carried further back to maintain the balance, and hence a hollow back is produced. Ankylosis of the hip in a flexed position causes lordosis when the limb is brought straight down as in walking. Therefore in cases of lordosis one should remember that it is a secondary condition dependent on diseased conditions of the viscera or extremities and is comparati^'ely rarely an independent affection. Scoliosis. — A normal spine is either absolutely straight or very slightly convex to the right in the dorsal region, probably due to the increased use of the right hand. While scoHosis is called lateral curvature of the spine, it is not a simple lateral bending, but is a complex distortion (Fig. 481). R. W. Lovett has shown that a flexible straight rod can be bent in one plane either anteroposteriorly or laterally, but that a curved rod cannot be bent laterally without twisting or rotating, Inasmuch as the human spine is curved convexly backward in the dorsal region and convexly forward in the lumbar region, lateral bending is accompanied by rotation of the vertebrae and their attached ribs. The bodies of the vertebrae are carried toward the side of the convexity of the curve and the ribs on that side project backward, producing a marked hump and often an elevation of the shoulder. As a primary curve forms, an attempt is made to restore equilibrium by bending the remaining portion of the spine in the opposite direction, hence the curves, if of long duration, are double or compound, and these secondary curves are called compensating curves. Marked lumbar curves are usually accompanied by prominence of the hip on the side of the convexity, but the pelvis usually remains level. Should the length of the limbs be unequal, allowing tilting of the pelvis, the prominence of the hip would be on the side of concavity. It is obvious that the weight of the body tends to aggravate these pathological curves. The treatment of scoliosis is directed to correcting these faulty curves by exercises and appliances intended to support and stretch the body on the contracted or depressed side and restore the tone and power to the relaxed muscles and tissues of the opposite side. arching over and uniting posteriorly. This union begins in the dorsal region and progresses towards the head and sacral regions. Failure of union constitutes spina bifida. It is most frequent in the lumbar and sacral regions. Usually a sac formed of the spinal membranes protrudes and contains the spinal cord flattened out like a strap passing down on its posterior surface, but sometimes the sac contains no nervous elements. Frequently the sac is so thin that it soon inflames, ruptures, and allows escape of the cerebrospinal fluid, and death ensues from meningitis. The parts below are not infrequently paralyzed and hydrocephalus may coexist. Operative procedures have been frequently successful in mild cases, but in extensive lesions they have been quite fatal, and even when primarily successful may be followed by the development of hydrocephalus. COLUMN. Caries of the Spine. — While caries of any part of the vertebrae may occur from injury, it is almost always the result of tuberculous disease in the bodies ; the pedicles, laminae, and processes remain unaffected. As the bodies become destroyed the anterior portion of the spine collapses, and this causes a projection of the spines of the affected vertebrae posteriorly or kyphosis. This projection of one or more spinous processes is the surest indication of spinal caries or Pott's disease. There is also rigidity of the affected region. This is recognized by the attitude assumed and by having the patient, if an adult, bend the back anteroposteriorly. Small children should be placed flat on a table, face down, and then gradually raised by the feet. If the spine is normal the child will readily bend in the lumbar and lumbodorsal regions. The movable regions, embracing the cervicodorsal and dorsolumbar vertebrcC, are the sites most frequently affected. Distention of the abdomen Fig. 482. — Psoas abscess originating from spinal caries of the dorsolumbar vertebnc and following the psoas muscle to the groin. (From a sketch by the author of a specimen in the Mutter Ivluseum of the College of Physicians). and pain occur from involvement of the spinal nerves. The tenth dorsal nerve arrives anteriorly at the level of the umbilicus, the twelfth is midway between the umbilicus and symphysis and also sends an iliac cutaneous branch a couple of inches behind the anterior superior spine to the skin of the buttock, and below and in front of the great trochanter. The abdomen above the external inguinal ring is supplied by the hypogastric branch of the iliohypogastric from the first lumbar. Psoas abscess is common. The psoas muscle arises from the lower border of the body of the twelfth dorsal and the bodies of all the lumbar vertebra. The prevertebral fascia covering the bodies of the vertebrae is continued downward over the psoas muscle as its sheath. Therefore when pus forms in the bone it enters the sheath and follows it downward under Poupart's ligament, usually just outside, but sometimes, as it gets still lower down, to the inside of the femoral vessels (Fig. 482). At other times it works its way backward and points in the angle between the erector spinae muscle and the twelfth rib, or along the edge of the erector spinae lower dowm, or a little farther out above the top of the middle of the crest of the ilium at Petit' s triangle (see page 394). It may also find an exit through the great sacrosciatic notch and point on the posterior aspect of the thigh. Pus originating in the cervical region produces retropharyngeal abscesses, which, if involving the second to the fifth cervical vertebrae, may either point in the pharynx or work outward to the posterior edge of the sternomastoid muscle (see page 156). The vertebrae may be dislocated and fractured. Dislocation is rarer than fracture ; it is most common in the cervical region. The cervical vertebrae have their articular facets sloping downward and backward, hence dislocation occurs when the upper vertebrae are pushed in front of the lower. process. The cervical spine normally has but slight rotation, hence when luxated one articular surface is rotated or pushed over and in front of the one below, the opposite articular surface acting as the axis and the distance between the two articulations as the radius of the arch in which the luxated parts move. The elevation of the luxated articular process over the one below is favored by the bending of the spine above toward the opposite side. The head is rotated and inclined toward the uninjured side. Bilateral luxation is rare without associated fracture. It is produced by anterior flexion, and the head and neck are inclined forward while the lower vertebra of the dislocated joints inclines backward, producing a kyphotic condition. Luxation affects most often the fourth, fifth, and sixth cervical vertebrae. The atlas may be dislocated forward or backward by rupture of the transverse ligament, fracture of the odontoid process, or by a slipping of the process under the ligament. extension is made and the head gently rotated. Fracture of the spine is frequently associated with luxation. It is most frequent low down in the cer\ical region and at the junction of the dorsal and lumbar vertebrae, these being the places where the more fixed dorsal portion passes into the more mo\able cervical and lumbar portions (Fig. 485). The vertebrae are supported at three points — the bodies and the two articular processes. The spinous and articular processes are rarely fractured alone; they may be broken, however, by direct violence. The laminae on each side of the articular processes may be broken and the detached part with the spinous process may be pushed inward, injuring the cord. Fracture of the bodies is most frequent and is due to anterior flexion. The bodies and intervertebral disks are compressed, crushed, and torn. This is accompanied by either luxation or fracture of the articular processes, and occurs most often in the region of the lower dorsal vertebrae. Injury to the cord is common. The parts are not often fixed in a markedly displaced position, as is the case with luxations of the neck, hence attempts at reduction are rarely necessar}' and fixation is to be aimed for in treatment. The site of injury is determined not only by an examination of the spinous processes but also by the extent of interference with the functions of the cord (see page 483). SPINAL CORD AND IT.S MEMBRANES. The spinal cord in the male is 45 cm. ( iS in.) long. In the foetus of three months the cord extends to the end of the spinal canal; at birth it has risen to the third lumbar \ertebra, and in the adult it is opposite the lower border of the first. It will thus be seen that the point of exit of the spinal nerves from the cord is always some distance higher up than their exit from the intervertebral foramina. The cord is enlarged in the cervical and lumbar regions, the cer\-ical enlargement ending opposite the second dorsal, and the lumbar enlargement beginning about opposite the tenth dorsal vertebra and decreasing gradually. These enlargements correspond with the origin of the ner\es to the upper and lower extremities. The spinal cord is divided into so-called segments. These are thirty-one in number ; eight are cervical, twelve thoracic, five lumbar, five sacral, and one coccygeal. Each segment embraces that portion of the cord which gives e.xit to one pair of anterior or motor root fibres and receives one pair of posterior or sensory root fibres. These segments are a variable distance above the point of exit of the nerves from the bony spinal column. Besides motor and sensory functions they exercise control over certain reflex movements and functions. The control of the bladder and rectum is located in the fifth and sixth sacral segments; the cremasteric reflex is governed by the first and second lumbar ; the plantar or Babinski reflex by the first to third sacral, as is also ankle clonus; and the patella reflex by the second and third lumbar segments. They likewise exert a trophic influence, and the appearing of bed or pressure sores without ample cause is presumptive evidence of a spinal lesion of the segments supplying the part. TRANSVERSE SPINAL LESIONS. In endeavoring to localize transverse lesions of the cord, such as result from traumatism, tumors, etc., one must bear in mind that the spinal nerves originate from segments in the cord some distance above where they make their exit from the spinal . , .■^^.^- 486. — Diagram of distribution of cutaneous nerves, based on figures of Hasse and of Cunningham. On T/i T/9 T^' ^j^^^ supplied by indicated nerves are shown; on left side, points at which nerves pierce the deep fascia. ^ .' \^ ' ^^.' divisions of fifth cranial nerve; GA, great auricular; GO, SO, greater and smaller occipital; SC, superncial cervical; St. CI, Ac. sternal, clavicular, and acromial branches of supraclavicular (Scl); Ci. circumflex; Mi>, musculqspiral; IH, intercostohumeral; LIC, IC, lesser internal and internal cutaneous; EC, external foramina. Chipault ("quoted by Starr) gives the following practical rule: "In the cervical region add one to the number of the vertebra, and this will gi\-e the segment opposite to it. In the upper dorsal region add two; from the sixth to the eleventh dorsal vertebra add three. The lower part of the eleventh dorsal spinous process and the space below it are opposite the lower three lumbar segments. The twelfth dorsal spinous process and the space below it are opposite the sacral segments. ' ' The spinal cord ends at the lower part of the first lumbar vertebra. Other mtnnsic muscles of the hand J In fractures of the dorsal region Thorburn has shown that the lesion is usually two vertebra higher than the nerve coming out from below the displaced vertebra. They cause paralysis of the abdominal muscles, legs, bladder, and rectum. According to Starr, fractures in the region of the last two dorsal vertebrae cause anesthesia up to Poupart's ligament, and if the patient recovers the thighs remain paralyzed. In fractures of the upper part of the lumbar region the paralysis may be Hmited to the legs below the knees but involves the bladder and rectum. Recovery leaves the patient with some power of getting about on crutches with the aid of apparatus to keep the ankles and knees firm, as the thighs are under voluntary control. Lesions below the first lumbar, those of the cauda equina, give paralysis of the feet and peronei, loss of control of the bladder and rectum, and anaesthesia in the saddle-shaped area on the buttocks, about the anus, and on the posterior part of the genitals. The diagnosis between lesions of the cauda equina and lower portion of the cord is not always possible. The prognosis of lesions of the cauda equina is, of course, much better than when the cord itself has been injured. has a dura mater, arachnoid, and pia mater. Dura Mater. — The outer or endosteal layer of the cerebral dura mater ends posteriorly at the edge of the foramen magnum but anteriorly at the third cervical vertebra. The inner or meningeal layer continues dowmward as a tough fibrous tube from the foramen magnum to the second or third sacral vertebra, and thence is prolonged downward as a fibrous cord (coccygeal ligament) to be attached to the periosteum over the coccyx. The dura mater in the spine does not, as in the skull, act as a periosteum. The vertebrae have a separate periosteum in addition. Between the dura mater and the bodies of the vertebrae is a somewhat loose space filled with fat, fibrils of connective tissue, and a venous plexus. In injuries these vessels are ruptured and bleed and give rise to clots; the blood, however, does not get inside the membranes and the effusion rarelv assumes a sufficient size to produce compression of the cord. These veins pierce the bVamentum subflavum and thus communicate with the dorsal spinal veins. The dura mater is almost never torn in injuries even though the cord may be crushed (Fig. 4S7). of the spinal cord is a stouter membrane than the cerebral arachnoid. Above it is continuous with the cerebral arachnoid at the foramen magnum. Below it blends with the dura at about the level of the third sacral vertebra. Thus it is seen that while the cord itself ends at the lower border of the first lumbar vertebra the subarachnoid cavity is prolonged nearly or quite to the third sacral. As in the brain, the cavity between the arachnoid and the dura above is slight, the two membranes being practically in contact, so that there is almost no subdural space. Between the arachnoid and pia, however, there is a considerable cavity which is continuous with the same space beneath the cerebral arachnoid. It communicates with the fourth ventricle just above the calamus scriptorius by the foramen of Magendie in the median line, and at the sides by the foramina of Key and Retzius, and also by slits at the descending horns of the lateral ventricles. Hence it is that the ventricular fluid can be drained by a lumbar puncture. Through this subarachnoid space pass the septum posticum behind and the ligamenta denticulata on each side from the pia to the dura mater. It is also tra\'ersed by the anterior and posterior roots of the spinal nerves, the former being in front and the latter behind the ligamentum denticulatum. The arachnoid contains neither vessels nor nerves (Fig. 488). mater is thin and closely invests the cord. It carries the blood-vessels of the cord and sends prolongations posteriorly to the dura as the septum posticum, laterally as the two ligamenta denticulata, and also around the anterior and posterior roots of the spinal nerves. teries supplv the spinal cord, an anterior spinal in the median line of the anterior surface and two posterior Coccyx Fig. 487. — Spinal cord enclosed in unopened dural sheath lying within vertebral canal: neural arches completely removed on right side, partially on left, to expose dorsal aspect of dura; first and last nerves of cervical, thoracic, lumbar, and sacral groups are indicated by Italic figures; corresponding vertebrse by Roman numerals. (Piersol.) spi7iar]usi behind the posterior spinal roots (Fig. 489). The veins are more numerous. They consist of three sets or plexuses, one on the cord in the meshes of the pia mater, another in the spinal canal between the dura mater and the bone, and the third on and around the outside of the vertebrae.^ The veins on the cord in the anterior and posterior median fissures communicate above with the veins of the medulla. The lateral veins empty through the radicular veins which accompany the spinal nerve roots. The veins in the spinal canal form anterior and posterior plexuses between the dura and bone and communicate with the extraspinal plexuses around the laminae and spinous processes posteriorly (dorsispinal veins) and the plexus around the bodies anteriorly. hemorrhages, though sometimes caused by disease, are usually the result of injury. They frequently accompany fractures and dislocations. They may be either extradural, intradural, or in the cord — hfematomyelia. They exist either coincident with the original injury or appear within a few hours. Spinal hemorrhages are rarely large and those in the substance of the cord are the more common. They are usually venous. Extradural hemorrhage comes from the plexuses between the dura and bone and the clot may extend through the intervertebral foramina. It is usually of small extent and practically does not produce paralysis from pressure on the cord, hence operation for its relief is useless. Intradural hemorrhage comes from the vessels of the pia and may invade not only the subarachnoid but also the subdural space. It may remain localized at the site of injury or the blood may sink and fill a considerable portion of the spinal canal. Owing to the looseness of the cord in its dural sheath the hemorrhage spreads and does not usually give rise to pressure symptoms, hence operation is rarely advisable. Large hemorrhage sometimes comes down from cerebral apoplexy or injuries. Hcematomyelia. — Hemorrhage into the substance of the cord may be caused by extension or accompany the contusion due to dislocation or fracture. The paralysis which follows serious injuries of the spine is usually due to hemorrhage into the gray or white matter of the cord. The gray matter being the softer is the more frequently affected, the blood penetrating it for quite a distance. Hemorrhage into the gray matter destroys it and produces an incurable paralysis. When into the white matter restoration of function through absorption may occur in from four to six weeks. In either case operation usually is of no service. The location of the hemorrhage will be revealed by the interference with the functions of the cord. The hemorrhage can occur in the form of a column of blood infiltrating the gray matter of several segments in one or both directions from the starting-point. The longer extension is usually toward the brain. It is usually limited to one side of the cord. Generally in small and sometimes in large hemorrhages the effect is mainly mechanical, but especially large hemorrhages may be surrounded by areas of softening. -Upper part of spinal cord within dural sheath, which has been opened and turned aside; ligamenta denticulata and nerve-roots are shown as they pass outward to dura. (Piersol.) FUNCTIONS OF THE CORD AND SPINAL LOCALIZATION. The direct or anterior pyramidal tract is motor; the impulse coming from the cerebral cortex passes down the spinal cord on the same side and thence to the anterior horn of the opposite side to supply mainly the muscles of the arm and trunk. The crossed or lateral pyramidal tract transmits motor impulses coming from the cortex which cross in the lower part of the medulla and descend on the opposite side. It supplies muscles on the same side as that on which the tract is. The direct cerebellar tract conveys impressions of equilibrium. The anterolateral tract (ascending tract of Gowers) conveys impressions of temperature and pain. The vestihclospinal tract — (descending tract of Lowenthal) is an indirect motor path. Lissauer s tract is composed of ascending fibres from the posterior nerve-roots. The posterolateral (column of Burdach) conveys common sensation. The posteromediaji (column of Goll) conveys muscular sense. One Lateral Half. — Brown-Sequard syndrome ; complete loss of power below on the same side as lesion and slight loss of power below on opposite side ; anaesthesia complete on opposite side below lesion. secondary resuks of the paralysis. Syringomyelia is an acquired enlargement of the central canal or the formation of new canals in the gray matter. It produces motor, sensory, and trophic disturbances which \ary according to the part of the cord attacked. Progressive Muscular Atrophy (Duchenne's Disease). — The atrophy begins most often in the hands and extends to other parts of the body. Then occurs an atrophy of the gray substance of the anterior horns which may extend to the brain ; even the white substance of the direct and crossed pyramidal tracts may also show degeneration. There is a type in which there is a lack of demonstrable cord lesions. Among its various forms are those called pseudomuscular hypertrophy, progressive muscular dystrophies (Erb), and primitive progressive mvopathies (Charcot). Arthritic Muscular Atrophy.. — Disease of the joints often results in marked disturbance of the gray matter of the cord, which in turn is followed by muscular atrophy (Church: Church and Peterson, Nervous and Mental Diseases, page 38). Lesi07is Affecting Principally the White Matter of the Cord. — The principal lesions affecting the white matter are lateral sclerosis, locomotor ataxia, combined posterolateral sclerosis, Friedreich's ataxia, and hereditary spastic paraplegia. Lateral sclerosis, or spastic paraplegia, is almost unknown as a primary affection. It is a sclerosis of the pyramidal tracts. It occurs as a secondary degeneration, the result of cerebral disease, producing the spastic paraplegia of infants — Little's disease — and also follows transverse lesions of the spine from tumors, caries, fractures, etc. Locomotor ataxia, or tabes dorsalis, when advanced may affect the entire portion of the cord between the posterior horns and the commissure, from the filum terminale to the medulla. It begins in Clarke's column (a group of cells in the posterior horn of the cord extending from the seventh cervical to the second lumbar nerves) and may involve the direct cerebellar tracts and Gowers's ascending anterolateral tracts and also the posterior nerve roots. It produces both motor and sensory disturbances as well as trophic changes. Combined Posterolateral Sclerosis — (Ataxic Paraplegia of Cowers). — This produces symptoms combining spastic paraplegia and locomotor ataxia. The following structures are affected: columns of Burdach, Goll, crossed pyramidal tract, direct pyramidal tract, and not always the ascending tract of Gowers. often appearing through many generations. There is a sclerosis of the columns of Goll and Burdach, crossed pyramidal tract, Gowers's tract, direct cerebellar tract. Lissauer's tract, and often atrophy of the cells of Clarke's column. Hereditary Spastic Paraplegia. — This is a degeneration of the pyramidal tracts, columns of Goll and Burdach, and direct cerebellar tract. The disease has been traced through many generations, purpose of producing spinal anaesthesia. The lumbar region is usually selected and the puncture made in the median line or to one side and _ either above or below the spine of the fourth lumbar the crest of one ilium to that of the opposite side passes through the lower part of the spine of the fourth lumbar vertebra. The puncture should always be made below the upper border of the second lumbar vertebra, because the spinal cord extends down to that point (Fig. 490). The lumbar spines are nearly or quite horizontal and do not incline downward as do those of the cervical space between the vertebrae posteriorly is increased. The needle used should be from 6.25 cm. (2}^ in.) to 10 cm. (4 in. J lono-, according to the age and size of the patient. It should be introduced in the median line and pushed upward. In its entrance it pierces the muscles, then the ligamentum subflavum, which passes from one lamina to the other, and finally the dura mater and arachnoid. Failure is liable to occur either from the patient straightening the spine when the puncture is made or from failure to enter the spinal membranes owing to pushing the dura in front of the cannula. A needle enters more readily and surely than does a small trocar with its cannula. The shoulder formed by the cannula, particularly if not well made, is apt to push the tough dura ahead of it instead of puncturing. Laminectomy. — The laminae pass from the transverse and articular processes to the spinous processes. On each side of the median line the erector spina; muscles form thick masses and the spinous processes lie in the groove between them. Hence, in doing a laminectomy, the depth at which the laminae lie is apt to be found much greater than is expected. An incision is first made directly on the spinous processes and continued down on each side to the laminae. With a chisel-like periosteal elevator the attachments of the muscles and periosteum are detached from the base of the spinous processes and laminae as far out as the transverse processes. The bleeding from the muscles is controlled by packing. The laminae may be divided with a saw inclined inward or the supraspinous, interspinous, and subfiava ligaments may be divided, the spinous processes cut close to their base and removed, and finally the laminae removed with bone forceps. When the laminae are removed the dura mater is found separated from the bone by fat and connective tissue. The veins here encountered may bleed freely but cease on pressure being made. If necessary the dura may be opened, in which case the portion of the body toward the head may be lowered to prevent too great loss of cerebrospinal fluid. The roots of the spinal nerves will be found passing out laterally and should if possible be avoided. If the posterior or sensory root is divided it has the same tendency to re-unite as do sensory nerves elsewhere, but division of the anterior root causes permanent motor paralysis. The dura and other structures are then sutured without drainage. We saw that prehension, characterized by mobiHty, was the distinguishing feature of the upper extremity and that the shoulder-girdle was composed of two bones,was loosely joined to the trunk, and held the upper extremity out away from it. The lower extremity on the contrary has two functions, it must bear the weight of the body and must move this weight around from place to place; hence strength is essential and a less amount of mobility suiifices. To meet these changed conditions the lower extremity differs in its construction from the upper in the following respects: The pelvis is composed of the pelvic girdle on each side (innominate bones), and the sacrum and coccyx posteriorly. It serves two purposes. It supports and protects the abdominal and pehic viscera, and serves as the connection between the trunk and the lower limb. It is divided into two parts — the false pelvis, above the ihopectineal line, and the true pelvis, below the iliopectineal line. The false pelvis serves to support the abdominal viscera, as its name indicates, like a basin. In man it is large and flaring- because his normal position is upright, but in the lower animals, as the quadrupeds, whose normal position is horizontal, it is smaller and less prominent. The true pelvis contains and protects the pelvic organs and also serves as the connecting link between the trunk above and the extremity below; hence, as it has a double function, it has of necessity a composite structure. In order to contain and protect the pelvic viscera it is made hollow, and in order to support the weight of the body on the legs it is made strong. The pelvic contents are not exposed to injury to the same extent as is the brain; therefore, instead of having a complete covering of bone, like the skull, the bony pelvis is merely a framework comprised solely of those parts essential to strength. MECHANISM OF THE PELVIS. As was pointed out by Henry Morris ("The Anatomy of the Joints of Man," p. 115), the bony pelvis is composed of arches. The two main arches are the femorosacral and the ischiosacral. These are strengthened by subsidiary arches which join the extremities of the main arches so as to strengthen and fix them. Fig. 491. — The femorosacral arch. The main arch passes upward from one hip-joint to the other through the sacrum : the subsidiary arch passes downward from one hip-joint to the other through the pubes. Fig. 492. — The ischiosacral arch. The main arch passes upward from one tuberosity of the ischium through the sacrum down to the opposite tuberosity; the subsidiary arch passes forward from one tuberosity of the ischium through the pubes and back to the opposite tuberosity. Femorosacral Arch. — This arch extends from the acetabula on the sides to the sacrum in the middle, which is its keystone. The weight of the body is transmitted downward through the spine to the sacrum, and then through the two sides of the femorosacral arch to the heads of the femurs. For an arch to be effective its two extremities must be firmly anchored, so that they do not separate when pressure is made on it. In artificial arches, as used in bridges, this separation is guarded against by a rod running from one extremity to the other, forming a chord of the arc. In the pelvis this mechanism is impossible, because this " tie-rod" would infringe on the cavity of the pelvis, and it is to obviate this that a counter arch is introduced. This secondary arch is formed by the rami and bodies of the pubic bones, and passes anteriorly from one acetabulum to the other on the opposite side. It is much weaker than the primary arch (Fig. 491). Ischio-sacral Arch. — In sitting, the pelvis, viewed laterally, is in much the same position as in standing, being in both almost vertical and beneath the spinal column. The thighs, however, are horizontal and the bulk of the weight is supported by the tuber ischii. From the keystone or sacrum the weight is transmitted through the ilium and body of the ischium to the tuberosities on each side. This primary arch is strengthened by the secondary arch formed on each side by the ramus of the ischium and the descending ramus and body of the pubis. Notice that this likewise is weaker than the primary arch (Fig. 492). The flaring wings or alae of the ilium are not infrequently fractured by direct violence. The line of fracture is usually transverse (Fig. 493). The displacement is slight on account of the muscular attachments of the iliacus muscle inside and the glutei muscles outside. The anterior third of the crest of the ilium is subcutaneous and prominent, hence by manipulating it crepitus can usually be elicited and the diagnosis made. Recumbency and the support afforded by adhesive plaster is all the treatment necessary. The more serious fractures, however, are those of the true pelvis. The pelvic cavity is somewhat heart-shaped; the sacrum projects anteriorly and is so strong that it is rarely fractured. At or just outside of the sacro-iliac joints is, however, one weak point; between the acetabulum and the pubes, through the rami of the pubes and ischium and thyroid foramen, is another; and at the symphysis is a third. The most frequent fracture passes through the pelvic ring twice, anteriorly through the rami of the pubis and ischium and thyroid foramen and posteriorly through or just external to the sacro-iliac joint. Whenever a fracture of the pelvis is suspected, search for this fracture. Examine the rami of the pubes. Pressure made along Poupart's ligament just external to the spine of the pubes will usually reveal a tender spot and may elicit crepitus. A digital examination through the rectum or vagina may likewise indicate the site of the fracture. The bladder is frequently wounded, the rectum almost never and the urethra rarely. The symphysis, while comparatively a weak part is rarely the site of injury. In childbirth the attachment of the pubes to each other becomes relaxed and a slight physiological separation occurs. Fig. 493. — Diagram illustrating fracture of the pelvis; one fracture is seen passing through the ilium; the other passes through the sacro-iliac articulation posteriorly and the thyroid foramen anteriorly. TRUNK. The human body usually occupies one of three positions: standing, sitting, or lying. The functions of the lower extremity are to afford support to the body and accomplish locomotion, therefore any disturbance of the normal relation of the extremities to the trunk interferes with the carrying out of those functions and proper support is not given and locomotion is imperfect. In such cases the positions assumed in standing, sitting, and lying are abnormal, often to an extent sufficient to constitute serious deformities, and locomotion, as in walking or running, is seriously impaired or rendered impossible. The connection of the lower extremities with the trunk is through the means of the pelvic girdle and spinal column; therefore the pelvis and ^■ertebrae above exert a marked influence on the extremities below and must be taken into consideration. The normal upright position of man is obtained by maintaining a proper balance. This balance can be disturbed either anteroposteriorly or laterally. The lower limbs are placed laterally, one on each side; this gives greater stability in that direction, so that when a person falls it is usually in a forward or backward direction rather than toward the side. Anteroposterior Equilibrium. — In the upright position the highest joint is that between the occiput and atlas and the lowest that of the ankle; to enable the body to be in a state of rest, in the upright position, with the use of the least amount FiR. .4. — The body in the erect position; the centre of gravity c is about in the upper lumbar region; d-e is the base of support. The vertical line a-h through the centre of gravity c passes through the occipito-atloid joint above.in front of the sacro-iliac joint g. the hip-joint /}, the knee-joint i and the ankle-joint ;' and falls between the points of support d-e, passing through the astragaloscaphoid joint. Hyperextension of the hip and knee is prevented by ligaments. Fig. B. — W'hen the trunk is inclined forward by bending at the hip- joint, the increased projection of the head and upper portion of the trunk in front of the centre of gravity is counterbalanced by the increased projection of the hips and lower portion of the trunk posteriorly. The vertical line through the centre of gravity still cuts the base of support d-e and the body remains in a state of equilibrium. equilibrium and it falls. Fig. D. — If the body, as occurs in some diseases and injuries, is inclined so far forward as to bring the vertical line a-h through the centre of gravity c. in front of the base of support d-e. then it is in a state of unstable equilibrium and additional support is used, in the form of a cane, to prevent falling forw^ard. of muscular exertion these joints are placed almost vertically one above the other. For the same reason if any part of the skeleton lies in front of a line joining the condyle of the occiput with the astragalo-scaphoid joint it is counterbalanced by a projection toward the opposite side. Thus the anterior curve of the cervical region is followed by the posterior curve of the dorsal; the anterior of the lumbar, by the posterior of the sacral. The hip-joint has its centre of motion slightly behind the centre of gravity as has also the knee. A vertical line through the center of gravity must fall within its base of support. This latter is formed by the arch of the foot ; its two ends are the tuberosity of the calcaneum posteriorly and the head of the first metatarsal bones anteriorly. The body is in the position of greatest stability when the centre of gravity is midway between those two points, which is when it passes through the astragalo-scaphoid joint. As the line of gravity passes from the centre of the arch toward the ends, equilibrium becomes more unstable until, when it passes beyond them, it is lost and the body begins to fall. In maintaining a normal erect posture hyperextension of the hip-joint is prevented by the anterior or iliofemoral ligament; hyperextension of the knee is prevented by the lateral, posterior, and crucial ligaments (Fig. 494, A). The main muscular efforts required are those of the muscles of the back of the neck to hold the head level, owing to the head being heavier anterior to the condyles, and the muscles of the back of the leg to prevent the dorsal flexion at the ankle, due to the centre of gravity falling in front of the anklejoint. When a person falls asleep in the erect posture the head drops forward and when a soldier is shot his calf muscles give way and he falls forward on his face. Deformities of the spine affecting its curves have already been alluded to (page 478). When the spine is the part affected it is usually the case that the secondary curve fully compensates for the increased primary one, hence there is no necessity Fig. C. — If the relative length of the two legs is altered, as by placing a block beneath one of them, the pelvis and upper portion of the body inclines to the opposite side, until a vertical line a-b through the centre of gravity c falls beyond the extremity of the base of support d-e and the body is in a position of unstable equilibrium. muscular effort. for any change in the position of the joints below, and we find people with marked deformities of the spine who are normal from the waist down and who stand and walk perfectly well. Occasionally a case presents itself in which the secondar\^ curve has not entirely compensated the primary one and then the body is bent at the hips until the centre of gravity is brought o\-er the base of support (Fig. 494, B). If the deformity throws the centre of gravity too far back, by bending the hips it will be brought forward, but if for any reason, such as ankylosis, flexion is impossible, then it cannot be corrected at the hip-joint, and therefore in such cases equilibrium is unstable and the body falls (Fig. 494, C). If from deformity the centre of gravity is thrown so far forward as to fall beyond the base of support then a cane or crutches is required (Fig. 494, D). When the hip-joint is involved it is never affected by hyperextension (the iliofemoral ligament prevents that), but alwavs bv flexion. This throws the centre of gravity forward; to bring it back a secondary cur\-e is produced in the lumbar region, and we have a condition of lordosis established: if this is insufficient then the knees may be partly flexed, and if both are insufl^cient then artificial support or criitclies must be used. This is the reason why flexion is sought to be avoided in the treatment of coxalgia, and why osteotomy is done when the hip is ankylosed in a flexed position. Practically speaking there is no efficient compensation occurring at the sacro-iliac joints, the pelvis moving with the lumbar vertebrae. Lateral Equilibrium. — In the upright position the centre of gravity falls midway between the ankles of the two feet. The fact of there being two points of support adds to the stability, which increases as the feet are separated. Hence it is that falls in an anteroposterior direction are more common than sideways. In standing the weight is transmitted from the spine through the femorosacral arches (page 490) to the hip-joint, thence downward through the femur and leg-bones to the astragalus. Here we have to deal with straight lines and angles rather than curves. The spine is normally straight; the line from the spine to the hip-joint is practically straight (no bending being possible), and from the hips to the feet is likewise straight, and the centre of gravity falls midway between the ankles (see Fig. 495, A). The two innominate bones and the sacrum form practically one solid bone, therefore the two hip-joints always maintain the same relative position to each other. When the leg is completely extended there is no lateral movement at the kneejoints. There is a marked more or less lateral movement in the subastragaloid joint which allows the leg to be inclined to one side without moving the foot. From these facts it is evident that lateral equilibrium can be disturbed by a deviation of the spine above the sacrum to one side (Fig. 495, B), and also by anything that affects the length of either leg (Fig. 495, C). The femorosacral arch is rarely affected, the most usual affection being sacro-iliac disease, or fracture, or relaxation of the sacro-iliac joint, especially in pregnancy. The lateral equilibrium is maintained almost solely by muscular force except when a position of rest is assumed. The hip-joint is capable of both abduction and adduction, and in the erect position the ligaments on both the upper and lower surfaces of the joint are lax and do not contribute any support. When, however, a position of rest is desired the hips are moved laterally so that the centre of griavity falls on one leg, which is kept extended, the opposite hip then descends until further adduction is stopped by the ligaments on the top of the hip of the other side (Fig. 495, D). These ligaments are the outer limb of the iliofemoral (Y) ligament and the reinforcing tendinotrochanteric band, an offshoot from the rectus tendon, the iliotrochanteric band, and by the iliotibial band from the crest of the ilium to the outer tuberosity of the tibia. Balance. — For the movements of the body to be properly performed a definite normal relation of the parts to one another must be maintained, whether the body is in a state of motion or at rest. During movement the position of the bones is controlled by the muscles ; when at rest, the muscles relax and the position of the bones is controlled by the ligaments. The weight of the body acts as a constant force pressing downward. For this constant pressure not to do harm it is nicely balanced on the bones and ligaments aided by the muscles. If any one of these three is disturbed the balance is altered and disability and ultimate deformity results. A distortion of a bone, as a badly united fracture, throws the weight and muscular action too much to one side and first the action of the part is impaired and then, if use is persisted in, deformity increases. When a person who is standing becomes tired they assume a position of rest, that is, their muscles relax, their joints are extended and the weight is borne on the ligaments. If, now, as in adolescents, these ligaments are weak, they give way. If in the foot, flat-foot results ; if in the knees, then knockknee ; if in the back, scoliosis or lateral curvature. If it is the bones which are the primary cause of the lack of proper balance, the surgeon by osteotomy, excisions, etc. , will restore them to their proper direction. If it is the muscles, as in infantile and other paralyses, transplantations, or the taking of a tendon from the strong side and placing it on the weak side, will be resorted to. If it is mainly the ligaments, these will be aided in their function by the use of apparatus, while by means of exercises the muscles are aided in regaining their normal power. The conservative surgery of the extremities has as its underlying principle the restoration of equilibrium to a part whose balance has been disturbed. DEVIATIONS OF THE SPINE ABOVE THE SACRUM. When, as in lateral curvature or scoliosis, there is a pathological curve developed, the centre of gravity is shifted from the midline to one side and it falls nearer the foot of the side toward which the trunk is inclined (see Fig. 496, A). This makes the equilibrium unstable so that to restore stability the hips are inclined to the opposite side and the centre of gravity is brought once more midway between the ankles (Fig. 496, B). This condition is produced when there is a single incomplete curve or deviation to one side; if, however, the curve is complete and again reaches the median line, as is often the case in scoliosis, then the centre of gravity is not disturbed and there is no lateral shifting of the pelvis (see Fig. 496, C). If the primary curve is accompanied by a secondary curve, both being complete and crossing the median line, then also there is no shifting of the pelvis (Fig. 496, D). If, however, the curves are so irregular as to shift more of the weight to one side than the other, then the pelvis shifts (Fig. 496, £). This causes the hip on the side opposite to the been restored. Fig. C. — If the deviation of the lower part of the trunk to the left is counterbalanced by a deviation of the upper part to the right then the vertical a-b through the centre of gravity c falls within the base of support d-e and the body remains in stable equilibrium. Fig. D. — If a complete curve in the lumbar region is compensated by a complete curve in the dorsal and cervical regions above, then the centre of gravity c is not shifted and a vertical line through it still falls within the base of support d-e, and the body remains in stable equilibrium. Fig. E. — If the curves are irregular, shifting more of the weight of the upper part of the body to the right, the pelvis is shifted to the left until the centre of gravity c is again brought within the base of support d-e and stable equilibrium is again restored. inclination to appear higher than the other, but it is not really so and the pelvis still remains level. It is therefore evident that it is unnecessary and unwise to attempt to correct the deformity by raising the apparently low hip by a high shoe. All these conditions occur in the lateral curvatures or scolioses of childhood and adolescence as well as the deviations which occur from empyema, sciatica, Pott's disease, and other affections. A knowledge of the principles involved is essential to comprehending their production and to directing the exercises and applying the apparatus used in their correction. The hip-joint is capable of flexion, extension, adduction, abduction, and rotation. From the hip to the foot is a straight hue; it can be shortened by disease or injury of the bones of the thigh or leg, and in rare cases it can be lengthened by disease at the epiphyses producing a more rapid growth than normal. It is almost unknown for hyperextension of the hip to exist, because if the femur is intact the iliofemoral ligament prevents it. If the head is gone then the upper end of the femur luxates upward and backward. Rotation likewise produces little effect on the position of the greater trochanter. Deformities due to flexion, abduction, adduction, and shortening are common. Increased Flexion. — Fig. 497, ^4 shows the normal position; Fig. 497, i9 shows hyperflexion at the hip. The increased forward bend of the pelvis necessitates an increase in the lumbar curve in order to maintain the anteroposterior equilibrium. increased hollowing of the back and an increased protrusion of the buttocks. Fig. C. — The left thigh is adducted and the right abducted. If the left hip is ankylosed in a position of adduction, as shown, then the pelvis is tilted down on the right, inclining the spine immediately above in the same direction. This moves the centre of gravity to the right, but is compensated by a shifting of the pelvis to the left, thus bringing the vertical through the centre of gravity within the base of support. If the right hip is ankylosed in abduction, the same condition results. In order to compensate for the uneven lengths of the limbs produced by tilting the pelvis, the knee of the apparently lengthened limb is bent. Fig. D. — The solid outline shows the position assumed when the right leg is shorter than the left. By placing a block under the short right leg the pelvis is raised to a horizontal line and the curves of the spine are straightened, as shown by the dotted outline. Thus lordosis is produced with the accompanying hollowing of the back and projection of the buttock. This is common in coxalgia and congenital luxations of the hip. Hyperadduction and Hyperabduction. — If there is hyperadduction, as when one hip is ankylosed in a position of adduction, as shown in the left limb (Fig. 497) 0> the pelvis is carried up toward the left; to restore the balance the spine is inclined to the right. If, however, the right limb is hyperabducted or fixed in a position of abduction, then in assuming the upright posture the right hip descends and the spine is inclined toward the side of the affected limb, as seen in the right hip of Fig. 497, C. In treating these conditions the spine can be brought straight by raising the rt-Mucted limb, but doing so will increase their inequality still more and shift the pelvis too far to the left. For this reason raising the shoe is not ad\-isable, but an osteotomy and removal of the adduction or abduction is the proper treatment. Effects of Shortening or Lengthening of a Lower Extremity. — The shortening of one limb produces the same effect as the lengthening of the opposite one: in other words it is the inequality of the limbs that counts. In Fig. 497, D the right extremity is the shorter; this causes the pelvis to till to the right, carrying the lower part of the spine with it and producing a right convex curve which is most marked in the lumbar region. To restore the equilibrium the parts above are carried to the left. Thus a lateral curvature is produced, which, contrary to those which originate in the spine, is accompanied by tilting of the pelvis. In these cases the deformity may be great. If the spinal curvature extends high the shoulders may be uneven, the hips are uneven in height and one projects farther out than the other, the legs may be visibly unequal in length, and there is marked limping of gait. The remedy is obvious. The short limb is to be made equal to the long one by raising the shoe or by other means. MEASUREMENT OF THE LOWER LIMBS. The ability to determine accurately the length of the lower extremities is essential to diagnosis and important in treatment. It is a difhcult thing to do and requires knowledge, care, and practice. It may be accepted as a fact that the limbs are nor- Fig. 498. — Measurements of the lower limbs, viewed from the front, a, left anterior superior spine; b. right anterior superior spine; c. left trochanter; ci, right trochanter; e, left internal malleolus; /, right internal malleolus; g, umbilicus; h, lower end of median line. Fig. B. — The limbs in this figure are of equal length but the pelvis is tilted. The pelvis a-b is tilted up on the left and down on the right. Apparent shortening of the left leg is seen by comparing g-e with g-f. Actual measurement shows a-e to be a trifle longer than h-f and a-c longer than b-d. Fig. D. — Legs unequal, pelvis tilted down on the side of the short leg. The apparent lengths g-e and g-f, taken from the umbilicus g, show the legs apparently equal, but the distance b-f is longer than a-e and the absolute or actual amount of shortening is only to be found by levelling the pelvis as in Fig. C, when the apparent and actual amount of shortening will be found to agree. mally equal in length. It is true that in rare cases there may be a slight inequality, but an amount of inequality readily detected by measurement will usually produce an unevenness in the gait, a slight limp. To measure accurately, bony landmarks are preferable to the soft parts, such as the umbilicus; these bony points must be carefully identified, they must be in their normal position, and the tape-measure must be accurately applied. shortening, while the former shows the apparent shortening. To identify the tip of the internal malleolus is usually easy enough, but the anterior superior spine is not so evident. The anterior portion of the crest of the ilium should be followed forward until its anterior superior spine can be distinctly felt. In applying the tape it is better not to rest it on the superficial surface of the spine nearest the skin but rather on its inferior surface nearest the feet. It should be placed below the spine and then pushed firmly upward and backward against its lower surface. The superficial surface of the anterior superior spine is often so rounded or flat as to make it an uncertain point to measure from. To put the parts in their normal position it is necessary to see that a line joining the two anterior superior spines is at a right angle with the long axis of the body, otherwise the tilting of the pelvis will vitiate the results. Fig. 498, A, front view, shows the normal relation; g- is the umbilicus; £'-/i, the median line; a, left anterior spine; 3, right anterior spine; c, left trochanter; d, right trochanter; e, left internal malleolus; /, right internal malleolus. The line ad is to be at right angles to ^--/i. Then a-e = b-f znd g-e = g-f. Fig. 498, B shows the effect of tilting of the pelvis, the legs being of equal length. a-b instead of being at right angles to g-h is inclined upward on the left side and down on the right. Apparent shortening is seen by comparing g-f with g-e. Actual measurement shows a-e to be a trifle longer than b-f. This is accounted for by the tilting causing b-d to approach each other while a-c have separated. If one hip is ankylosed its femur should be moved laterally until the line joining the two anterior superior spines is at right angles to the median line of the body; the opposite limb is then to be abducted to a similar degree and the measurements of the two limbs can then be compared. When the legs are unequal the pelvis is tilted down on the side of the short leg (Fig. 498, D). Apparent length taken from the umbilicus shows the legs equal, but the distance b-f will be found to be longer than a-e. This will not give accurately the actual amount of shortening because of the tilting of the pelvis. It can only be determined by levelling the pelvis so as to make the distances a-c and b-d equal. The length of the extremity below the neck of the femur can be determined by feeling for the tip of the greater trochanter on its upper posterior border and measuring to the external malleolus and comparing with the opposite side. WALKING. As locomotion is one of the main functions of the lower extremity, derangements of this function are to be explained by a knowledge of the normal action of its mechanism. The means by which support is accomplished have already been explained in the maintenance of equilibrium. Locomotion embraces walking, running, jumping, etc. Of these walking is the fundamental movement, and the others are only amplifications and modifications of it. In slow normal walking on a level surface the thigh moves on the pelvis, the leg on the thigh, the foot on the leg, and the toes on the rest of the foot. These movements are almost solely in an anteroposterior direction, there being almost no lateral or rotary movements ; these begin only when the actions become violent and irregular, such as are necessary in running, overcoming obstacles, etc. It is for this reason that a person may have no limp when walking slowly, but a very perceptible one when walking rapidly. There is always a small amount of lateral motion present which varies with the inclividual and the sex. by viewing the body laterally. In ordinary walking the body inclines forward 5 degrees, in fast walking 10 degrees, and in running about 22 degrees (Weber). In walking (Fig. 499, A) the body is inclined forward and at the same time one leg begins to advance (the right). This causes flexion of the left ankle and flexion of the right hip (Fig. 499, /? and C). As the right foot touches the ground it extends and the right knee flexes to avoid the shock of impact (Fig. 499, D), the left knee begins to flex and flexes more than the right in order for the left foot to swing clear of the ground while being advanced; if this was not done it would be necessary to raise the hmb by tilting the pehis up on that side. The left continues to advance tiexed while the right gradually extends (Fig. 499, E), and finally when the right is fully extended the left is likewise fully extended (Fig. 499, F) and strikes the ground with the foot about at a right angle to the leg. The object of flexion of all three joints is, first, to avoid shock in impact, and, secondly, to raise the free foot and allow it to swing forward clear of the ground. The object of extension is to push the body forward. Part Played by the Various Joints. — The hip-]o\vX flexes to an extent proportionate to the length of the step (Fig. 499, A). If this joint is put out of use by being ankylosed, first, the shock of impact is more severe, no flexion being possible; second, the limb can only be brought forward by bending the pelvis on the opposite hip, and, to a certain extent, the trunk above backward; third, to aid still more to advance the foot forward the pelvis will be rotated laterally on the opposite hip. This causes a swaying of the trunk backward and forward and a side swing or waddle of the pelvis. Fourth, the forward propulsive force is weakened by the loss of the hip extensors. The knee, like the hip, lessens the shock of impact by flexing. It raises the foot clear of the ground as it is swung forward, and it aids propulsion by extension. If ankylosed, shock is increased, onward propulsive force is lost, and it is necessary to tilt the pelvis upward in order to raise the foot from the ground and allow it to swing forward. This abducts one or both legs and causes marked waddling. The a?ikle also reduces shock and gives propulsion ; if ankylosed, shock is increased and propulsion weakened. This is the least necessary of the three joints and to substitute it artificial appliances are useful, so that in quiet walking limp may be almost lacking, but violent and complicated movements are to a large extent impossible. The toes, especially the big toe, aid in propelling the body forward. The hip is that portion of the body joining the lower extremity to the trunk. It differs in construction from the shoulder, because it is designed for strength as well as mobility; hence it is that the bones are heavier, stronger, with their processes more marked, and that the muscles also are bigger and more powerful. It is often the seat of injury and disease, the bones being fractured, the joint luxated, and frequently affected with tuberculosis and other diseases. The bones of the hip are the innominate bone and femur. The innominate bone has its shape determined by its relation to the trunk, being adapted to support and protect the viscera, while the femur has its shape determined by its relation to the extremity, being in the nature of a pole to support it. The innominate bone (Figs. 500 and 501) is composed of the ilhim. ischmm, and pubis. These are united in the acetabulum by the triangular cartilage and become ossified about the sixteenth year. The ilium has a crest which serves for the attachment of the transverse abdominal muscles. At its anterior extremitv is the anterior superior spine, and at its posterior extremity the posterior superior spine. Its larg^e flat portion, called the ala, gives origin from both its inner and outer sides to muscles running to the thigh below. The glutei muscles are attached to its outer surface and the iliacus to its inner. Immediately below the anterior superior spine is the anterior inferior spine ; to it is attached the rectus femoris tendon. The ischium is below and behind the acetabulum; its tuberosity gives attachment to the hamstring muscles — biceps (outer), semitendinosus, and semimembranosus (inner). Along the inner surface of the ramus of the ischium, in a fibrous canal (Alcock's), run the internal pudic vessels and nerve on their way to the perineum. They lie 4 cm. (i>^ in.) from the surface. The pubis lies below and anterior to the acetabulum. Its upper inner edge forms the iliopectineal line, M-hich is continued back to form the brim of the true pelvis. The superior or horizontal ramus goes to the ihum, while its inferior or descending ramus goes to the ischium. The upper surface of the superior ramus gives origin to the pectineus muscle; it is over this muscle that femoral hernia descends. The symphysis pubis is the junction of the two pubic bones in the median line. The crest is the upper anterior edge and gives attachment to the rectus and pyramidal muscles (for muscular Tuberosity of ischi Fig. 502. — Innominate bone, resting on its inner side, to show the wedge-shaped formation of its outer sur face. The apex of the wedge is Nelaton's line, running from the anterior superior spine to the tuberosity of the ischium; the anterior plane inclines downward and forward toward the pubis and the posterior plane inclines downward and backward on the ilium, attachments see Figs. 43S and 439, page 432). The outer extremity of the crest is the spine of the pubis. To it is attached the inner extremity of Poupart's ligament. The obturator foramen, if the body is in an upright position, is just below and a little anterior to the acetabulum; it is closed by a membrane which is incomplete above to give passage to the obturator vessels and nerve. — Anterior view of the upper end of the femur with muscular attachments. of the membrane gives origin to the obturator externus muscle and the inner surface to the obturator internus. This latter passes out of the pelvis through the lesser sacrosciatic notch just below the spine of the ischium. Through the greater sacrosciatic notch, above the spine, comes the pyriformis muscle and great sciatic nerve. The acetabulum is located at the junction of the ilium, ischium, and pubis, and lies a little to the outer side of the middle of Poupart's ligament, with the femoral artery passing nearer its inner than its outer edge. The obturator foramen is below and a little anterior to the acetabulum when the body is upright and more anterior when it is horizontal. The bottom of the acetabukim has a large fossa, to the upper portion of which is attached the ligamentum teres, while the lower portion contains a pad of fat. This fossa opens by a large notch, called the cotyloid notch, on the side toward the obturator foramen; therefore the bony socket is incomplete at this point. O. H. Allis has pointed out that a line passing from the anterior superior spine to the tuberosity, called the Roser-Nelaton line, forms the apex of a wedge, the ilium sloping down on one side while the ischium and pubes pass down the other. It divides the innominate bone into two parts, an anterior plane and a posterior plane The femur has its neck coming off from the shaft at an upward angle of about 127 degrees (125 degrees to 130 degrees). The head and neck do not lie in the same transverse plane as the line joining the two condyles, but are inclined slightly forward (about 12 degrees). Therefore the neck passes upward, inward, and a little forward. As the result of deformities or disease, the inclination of the neck to the shaft may be reduced, being 90 degrees or less. This condition is known as coxa vara. It may be increased, constituting coxa valga. The articular surface of the head forms slightly more than a hemisphere and has a pit below and posterior to its centre for the attachment of the ligamentum teres. At the outer upper extremity of the neck where it joins the-shaft is the greater trochanter. Its tip or most prominent point is toward its posterior surface and is just about opposite the centre of the hip-joint. Downward and inward from the greater trochanter, on the inner and posterior surface of the shaft, is the lesser trochanter. Between the trochanters anteriorly and posteriorly run the intertrochanteric lines. The great trochanter and the part immediately below and posterior gives attachment to the three glutei muscles, the short rotators (Fig. 504), the pyriformis, the obturators, internus with its two gemelli and externus, and the quadratus femoris. The lesser trochanter gives attachment anteriorly to the psoas and the iliacus and immediately below to the pectineus. The muscles of the hip are numerous and their action is often intricate: many muscles are usually used to produce a single movement. Some muscles not only cross the hip-joint but another joint as well. Thus the psoas crosses the hip-joint and pelvis to reach the spine. The hamstring muscles, the rectus femoris, gracilis, and sartorius cross both the hip-joint and knee-joint, as does practically the tensor fasciae femoris through its prolongation, the iliotibial band. The movements of the hip are flexion, extension, adduction, abduction, and rotation. Circumduction is a combination of the first four movements. rius, gluteus medius, and gluteus minimus. When fiexed the short rotators also aid. Internal rotation is produced mainly by the tensor fasciae femoris and the anterior portion of the gluteus medius and minimus; three muscles only. The iliopsoas acts as a weak internal rotator if the femur is in a position of extreme external rotation. External rotation is mainly due to the short external rotators — pyriformis, gemelli, obturators, quadratus femoris, the adductors, and the posterior portion of the three gluteals. To a slight extent the sartorius, iliopsoas, pectineus, and biceps may also aid at times. The crest of the ilium can be palpated in its entire length. In very thin people it causes an elevation of the surface, but usually it is marked by a depression. Its anterior third is subcutaneous and is more easily seen and felt than the posterior two thirds. A line joining the highest point of the crests passes through the fourth lumbar spine. A line joining the anterior superior spines in front passes below the promontory of The posterior superior spine, marked by a dimple, is best recognized by following the crest of the ilium to its posterior extremity. It is opposite the middle of the sacroiliac joint and the second sacral spine. The posterior inferior spine is 4 to 5 cm. ( I ^ to 2 in. ) directly below the posterior superior spine. The spine of the ischium, which marks the position of the pudic and sciatic arteries, is 8 to lo cm. (3 to 4 in.) below the posterior superior spine and the tuberosity of the ischium is 12 to 15 cm. (5 to 6 in. ). Running forward from the posterior inferior spine for a distance of 4 to 5 cm, (i^ to 2 in. ) is the great sciatic notch ; through it pass the pyriformis muscle, gluteal artery and nerves, and sciatic nerve. A line joining the posterior superior spine and the tip of the greater trochanter may be named the posterior iliotrochanteric line (iliotrochanteric line of Farabeuf). It marks roughly the posterior edge of the gluteus medius muscle and goes through the upper edge of the gluteus maximus. The gluteal artery and superior gluteal nerves cross this line at the junction of the upper and middle thirds, this being about opposite the posterior inferior spine. A line joining the tuberosity of the ischium and tip of the greater trochanter may be called the ischiotrochanteric line : it is crossed at the junction of its inner and middle thirds by the sciatic nerve. The greater trochanter is marked by an eminence in thin people and a depression in the plump and fat. Its anterior upper edge is crossed by the tendon of the gluteus medius and cannot be readily outlined. Its upper posterior extremity or tip is readily distinguished and is the spot used for measurements. This point is called the tip of the greater trochanter and must be searched for posteriorly. It is opposite the centre of the head of the femur and is on a level with the spine of the pubis. The Roser-Nelaton li^ie is one drawn from the anterior superior spine to the tuberosity of the ischium. It passes through the tip of the greater trochanter. It is of importance in fractures and dislocations (Fig. 507). Bryant's triangle (" Bryant's Surgery", vol. ii, p. 412) is to be drawn while the patient is lying on his back. One side is a perpendicular let fall from the anterior superior spine to the table, the other side is one joining the anterior superior spine and the tip of the greater trochanter, the base is a line running horizontally from the tip of the greater trochanter to the perpendicular line (Fig. 507). If the tip of the trochanter becomes elevated, as in fractures of the neck of the femur, it shortens the base of the triangle on the aflected side as compared with the base of the triangle on the sound side. The anterior iliotrochanteric line may be designated as a line joining the anterior superior spine and the tip of the greater trochanter. In normal individuals it slopes downward and backward, forming an iliotrochanteric angle (^b a c, Fig. 507) of about 30 degrees. In cases of fracture or luxation this angle becomes reduced as the shortening increases until the tip reaches the level of the anterior superior spine. A rough estimate of this angle by sight and palpation usually enables one to decide immediately as to the presence of shortening from fracture or luxation without the trouble of erecting Bryant's triangle. The anterior iliotrochanteric line forms the anterior side of Bryant's triangle and the anterior half of the Roser-Nelaton line. The gluteal cleft separates the buttocks. In its lower portion can be felt the coccyx. The glnteal {gluteofeinoral) fold is formed mainly by the subcutaneous fatty tissues and passes horizontally outward from the lower part of the gluteal cleft. A shortening of the leg on either side causes the corresponding fold to incline downward. It is marked in extension and gradually lessens on flexion and disappears when 90 degrees is reached. It is crossed obliquely downward and outward at about its middle by the lower edge of the gluteus maximus. Its disappearance in coxalgia is caused by the flexion incident to that affection. Ligation of the Gluteal, Sciatic, and Internal Pudic Arteries. — To ligate the gluteal artery incise the skin and part the fibres of the gluteus maximus in the upper two-thirds of a line joining the posterior superior spine and the top of the great trochanter (Fig. 508). Pull the lower edge of the gluteus medius up and the artery and superior gluteal nerve will be seen coming out between it and the pyriformis. To ligate the sciatic and internal pudic arteries an incision parallel to the one Fig. 507. — View of the outer surface of the bones of the hip showing Roser-Nelaton line {a-d), Bryant's triangle (a be), iliotrochanteric line, (a c) and the iliotrochanteric angle (b a c). just described but about 7.5 cm. (3 in.) lower is made through the gluteus maximus, and just below the edge of the pyriformis from without inward will be found the great sciatic nerve, lesser sciatic nerve, sciatic artery, and the internal pudic nerve and internal pudic artery crossing the spine of the ischium. The hip-joint, like the shoulder, is a ball-and-socket joint, and, like it, moves in all directions. The main function of the shoulder is mobility, but the functions of the hip are mobility and support. To give the necessary support and security, the band-like ligaments uniting the bones are strong and the extent of the movements is restricted. Macalister ("Text Book of Human Anatomy," p. 179) points out that while the shoulder has 118 degrees of motion around a sagittal axis, abduction and adduction, the hip has only 90 degrees; around a coronal axis, flexion and extension, the shoulder has 170 degrees and the hip only 140 degrees. In the vertical axis the shoulder rotates 90 degrees, while the hip rotates only 45 degrees. In the upright position the centre of gravity falls in front of the axis of rotation of the hip-joint. The head of the femur is 5 cm. (2 in.) in diameter and forms f of a sphere. Below and behind its centre is the depression for the attachment of the ligamentum teres. The acetabulum is much deeper than the glenoid cavity of the shoulder-joint and its depth is increased by the cotyloid ligament around its edge. This makes the joint air-tight and holds the femur in place by suction, hence it is called by AUis ("An inquiry into the difficulties encountered in the reduction of dislocations of the hip," Philadelphia, 1896) the sucker ligament. The acetabulum is incomplete at its lower anterior edge, forming the cotyloid notch. The cotyloid ligament bridges extremity of the ligamentum teres, which is attached to the ischium just outside. Running up in the floor of the acetabulum from the cotyloid notch is a depression in which is lodged the ligamentum teres and a pad of fat called the Haversian gland. The ligamentum teres is composed of synovial and connective tissue. It is not strong and ruptures at about 14 kilos; the small artery it contains affords nourishment for itself alone, only a very small amount of blood going to the head of the femur. Bland Sutton regards it as a vestigial structure and a regression of the pectineus muscle. It is too weak to add much to the strength of the joint, and the view of Allis that its function is to distribute the synovial fluid and act as a lubri- eating agent is probably correct. The great pressure to which the articulating surfaces of the hip-joint are subjected requires special lubrication and this is furnished by the ligamentum teres and Haversian gland. Iliofemoral Ligament (Bertins' ligament or Y ligament of Bigelow). — This is the strongest ligament in the body. The single stem of the Y ligament is attached to the upper edge of the rim of the acetabulum just below the anterior inferior spine. Its two branches are attached below to the anterior intertrochanteric line. Its upper edge is reinforced by a band from the ilium to the trochanter, the iliob'ochanteric band, and one from the reflected tendon of the rectus, the tendinotrochanteric band (Henry Morris) (Fig. 509). outward into the capsule from the horizontal ramus of the pubes. It is quite weak. Ischiofemoral Ligament. — Allis describes this ligament as follows: " It arises from the ischial portion of the rim of the socket and sends its fibres to the capsule to be blended with them. As its fibres extend upward they separate like two fingers or terminal processes, the one extending forward to the base of the oblique (posterior) line, the other running backward to the digital fossa (Fig. 510)." Capsular Ligament. — The capsule of the joint is composed of a thin sac strengthened by the band-like ligaments just described. Wherever there is no reinforcing band the capsule is weak. The posterior and lower portion is weaker than the anterior and upper portion. There is a weak spot between the arms of the iliofemoral ligament anteriorly, a branch of the circumflex artery usually entering here. Between the pubofemoral and inner edge of the ihofemoral ligament is another weak point. A bursa here separates the iliopsoas from the joint and often communicates with the joint. A third weak spot is on the lower posterior part of the neck between the two branches of the ischiofemoral ligament (Fig. 511 ). Injections into the joint Fig. 510.— The ischiofemoral or posterior Yligament. The stem of the Y is attached at the base of the tuberosity of the ischium and one branch is seen going toward the greater trochanter and the other toward the lesser, leaving a weak spot between them half-way down the neck of the bone. Fig. 511. — Hip-joint distended with wax; the capsule ends posteriorly half-way down the neck and is seen distended by the injection material protruding between the two arms of the ischiofemoral ligament. protrude very markedly at this point. The weakest part of the joint is the lower anterior, below the pubofemoral ligament and opposite the cotyloid notch; the strongest part is the upper anterior part. Classification. — Dislocations of the hip are either anterior or posterior (AUis)'. If the innominate bone is held horizontally it will be seen that the RoserNelaton line from the tuberosity to the anterior superior spine passes through the acetabulum. It forms the apex of a wedge the two sides of which pass down, one anteriorly and the other posteriorly (Fig. 512). Therefore when the head of the either an anterior or a posterior luxation. The attachment of the iliofemoral ligament immediately above the acetabulum and of the ischiofemoral directly below also tend to prevent the head's emerging at these places and favor its going anteriorly or posteriorly. Anterior luxations may be either low or high. The primary luxation is a low one into the thyroid foramen. Fig. si 2. — Innominate bone, resting on its inner side, to show the wedge-shaped formation of its outer surface. The apex of the wedge is Nelaton's line, running from the anterior superior spine to the tuberosity of the ischium; the anterior plane inclines downward and forward toward the pubis and the posterior plane inclines downward and backward on the ilium. If then the thigh is rotated outward the head rises, and it becomes a pubic luxation. Posterior luxations may also be either high or low. The primary luxation is a low one either on the spine of the ischium or in the sciatic notch, and by rotation of the thigh inward it becomes a high one on the dorsum of the ilium (Fig. 513). In certain very rare cases in which there has been an excessive amount of twisting the rotation is extreme and a form of dislocation called inverted is produced; it will be explained later. Mechanism of the Production of shaft an angle of approximately 128 degrees. 2. In speaking of inward and outward rotation is meant inward and outward rotation ■of the shaft of the femur. Thus if the head (and neck) is pointing inward and we rotate the shaft inward, the head rotates outward posteriorly. If, however, we rotate the shaft inward while the head is pointing outward then the head moves inward anteriorly. Thus it is seen that in rotating the shaft inward the head is moved inward or outward according to its original position. 3. That while actually the axis of the head and neck does not coincide with a line drawn transversely through the condyles, but inclines forward at an angle of 10 or 12 ■degrees, nevertheless for practical purposes we may consider that it does so coincide and normally points directly inward. lever action of the femur as its neck strikes the rim of the acetabulum and its greater Fig. 514. Luxation of the hip by indirect or leverage action. The shaft of the femur, from the greater trochanter out is the long arm of the lever, the head and neck form the short arm and the upper edge of ttie acetabulum and ihum immediately above is the fulcrum. When the femur is abducted the head is lifted out of its socket rupturing the capsular ligament. trochanter the ilium above. The head and neck are the short arm of the lever, the rim of the acetabulum or ilium is the fulcrum, and the shaft and distal extremity of the femur are the long arm. The head rises from the socket, ruptures a part at least of the capsular ligament, and then a thrusting force is added which pushes the head forward, producing a thyroid luxation (Fig. 514). If while the limb is hyperabducted the shaft of the femur is rotated out and the Fig. 515. — Posterior luxation of the hip produced bv rotation and direct thrust. The femur is seen to be flexed on the pelvis, adducted and rotated inward; a thrust in the direction of the arrow then sends the head out of the acetabulum onto the posterior plane. limb brought straight down, parallel with that of the opposite side, then likewise the head may pass forward into the thyroid or pubic position. If while the head is ort the anterior plane the thigh is fiexed and the shaft rotated inward, then the head follows around the outer edge of the acetabulum and passes from a thyroid to a dorsal position, forming a posterior luxation. Luxation by Adduction. — If the thigh is flexed and adducted the angle of the neck and shaft prevents any bony fulcrum from forming. If now the shaft is strongly rotated inward the iliofemoral or Y ligament becomes tense. It is wound around the neck of the bone and acts as a ligamentous fulcrum. The shaft revolves on its long axis, and as it turns inward the head turns outward and presses against the lower posterior part of the capsule, which ruptures, and a dorsal luxation is produced. A backward thrust in the long axis of the femur also favors the production of the luxation (Fig. 515)- . . By outward rotation of the shaft the head can be conducted around the edge of the acetabulum until it lies in the thyroid foramen on the anterior plane, thus changing a primary dorsal into a secondar)- thyroid luxation. The Rent in the Capsule. — The capsule ruptures at its lower anterior or posterior portion according to whether it is primarily an anterior or a posterior luxation. If, however, the limb is rotated while the head is out of its socket, as in the production of a secondary position, then the capsule is torn still further, but the Y ligament is practically never torn either when the original luxation occurs or the secondary. Fig. 516. — Showing the sciatic nerve caught around the neck of the femur. (After an illustration by Dr. Allis in his prize essay on the hip.) The rent in the capsule through which the head emerges has been proven both by Robert Morris and Dr. Allis to be always equal in size to the head of the femur and never a slit. Therefore in every case there exists a rent in the capsule large enough to allow of returning the head, provided it is not closed or obstructed by a rotation or malposition of the limb, or by some foreign substance such as torn muscle or infolding of the capsule. Injuries to the Muscles. — When the thigh is abducted the adductor muscles are made tense, and if it is hyperabducted they are torn ; these overstretched muscles, some of which may be ruptured, are the three adductors, the pectineus, and the gracilis. If the luxation is an anterior one the obturator externus will be torn because it arises from the outer surface of the thyroid membrane. If a posterior seen by comparing the position of the knees, the thigh is adducted and rotated inward. one the internal obturator may be injured. Allis has pointed out that when the head passes from one plane to another it may tear the obturator externus, quadratus femoris, and upper fibres of the adductor magnus. The tearing of these muscles usually exerts but little influence on the reduction of the luxation. Injuries to the Nerves. — Rarely the anterior crural nerve may be injured by being stretched over the head of the femur. The sciatic nerve has been injured, and Allis has shown how, when a dorsal is rotated into a thyroid luxation, the sciatic nerve is likely to be caught around the neck of the femur (Fig. 516). This is favored by making a large circle while circumducting the knee, and also by extending the leg on the thigh, thus making the nerve tense and causing it to lie closer to the socket. To detect this accident Allis advises that while an assistant pushes upward on the knee in the direction of the long axis of the femur, the surgeon by flexing and extending the knee will find the nerve alternately made tense and relaxed in the popliteal space. Signs of Luxation. — When \\xx^\ed posicrior/y the foot is inverted whether it is a low or high dorsal. The thigh is adducted, bringing the knee of the affected side in front of the sound one. The thigh is usually slightly flexed. There is shortening, and the higher the position of the head- the greater the shortening and the farther up the trochanter is above the Roser-Nelaton line. Shortening is best seen with the thighs flexed to a right angle (Fig. 517). marked. The thigh is abducted; this is more marked in the thyroid and less in the pubic. The thigh is flexed in the thyroid but may be straight in the pubic. There is no shortening but there may be a slight lengthening difficult to demonstrate (Fig. 518). Reduction. — As in the shoulder there are two methods of reducing a dislocated hip, the direct and the indirect. The direct consists in placing the head in "as favorable a position as possible and then directly pushing or pulling it towards the socket. The indirect consists in using the thigh as a lever and rotating the head into place. These methods may be used in combination. tions.— Patient flat on the floor on his back. Flex the knee on the thigh, and the thigh on the abdomen; this brings the head down from a high position to a low one below the acetabulum. Adduct the thigh slightly; this relaxes the Y ligament and prevents the head catching on the rim of the acetabulum. Grasp the ankle with one hand, then place the other hand or arm beneath the bent knee and lift upward and inward thus raising the head over the rim of the acetabulum into the socket. If the head does not enter rotate the thigh gently, first out and then in, lifting at the same time. This rotation is to open the rent in the capsule to its widest extent. Too much rotation narrows the rent and obstructs the entrance of the head. An assistant may at the same time endeavor with his hands to push the head up towards the socket. Another way of using the direct method (Stimson) is to place the patient face downward on a table with the thigh flexed at a right angle hanging over its end. The leg is then flexed at the knee and pressure made directly downward, gently moving or rotating the head from side to side. This is a safe and efiticient method. Direct Method for Anterior Luxations. — In pubic luxations first slightly abduct the thigh and rotate the shaft of the femur inward so as to transform the pubic to a thyroid luxation. For thyroid luxations flex the knee to a right angle, and then flex the thigh on the abdomen to a right angle or even more and slightly abduct (Allis). Then with one hand grasp the ankle and with the other hand or arm in the Fig. S18. — Thyroid luxation on tlie anterior plane. The thigh is flexed and abducted; the toes pointing forward. (From a photograph by Dr. Chas. F. Nassau.) small cut. knee in a small circle with e.xternal rotation, when the knee reaches the point of starting bring the limb down straight. Allis cautions against describing too large a circle with the knee on account of the liability of catching up the sciatic nerve. Fig. S20. — Reduction of a posterior (high) dorsal luxation by the indirect (lever) method of circumduction. The thigh is flexed and adducted; the knee describes the circle shown by the dotted line while the head pursues the course shown in the smaller cut to the right. The Indirect or Lever Method for Thyroid Luxations. — Slightly flex the thigh, about to half a right angle, and rotate outward. Slightly abduct or adduct if necessary to relax the capsule before rotating outward. Reversed Luxations. — In certain few cases, either from the pecuHar character and direction of the primary injury or from an ordinary anterior or posterior luxation becoming subsequently more widely displaced, there result what are known as reversed luxations. They are of two kinds, reversed thyroid and reversed dorsal. Reversed Thyroid. — In a thyroid luxation the toes point forward ; if now the leg is forcibly twisted until the toes point directly backward a reversed thyroid is produced (Fig. 521). In reducing it the head must be first rotated back to its original thyroid position and then reduced by the usual methods. Reversed Dorsal. — In a dorsal luxation the foot is inverted ; if now the leg is forcibly twisted outward until the foot is e\'erted, a reversed (or everted) dorsal luxation is produced (Fig. 522). To reduce it the leg must be rotated inward until the head resumes its original position posteriorly and then it may be reduced by the usual dorsal methods. In the production of both these reversed luxations the ligaments are torn still more and the iliofemoral ligament may even be partially detached from its insertion in the femur. ing the entrance of the head. Fragments of muscle may act likewise. To clear the socket Allis advises first, rotation to tighten the Y ligament and pressing the head firmly in ; second, to rock the head backward and forward and so clear the obstructing material out. To Release the. Sciatic Nerve. — If the sciatic nerve is caught around the neck of the femur and cannot be otherwise released, Allis advises extending the leg and cutting down on the nerve at the upper part of the popliteal space. It is then grasped and pulled taut, this releases it from the neck and the thigh can then be flexed and the head replaced : of course, if preferred, an incision can be made directly down on the nerve at the hip. To Reduce a Dislocation Complicated by Fracture. — To accomplish this Allis advises first a trial of the usual direct method of traction and pressure on the head and, if this fails, then while the head is held as near to the socket as possible by an assistant the thigh is brought down and traction is made downward. Congenital Luxations of the Hip. — In congenital luxations the acetabulum may be shallow, the head deformed, and the neck somewhat twisted on its shaft. These luxations are usually posterior. Sig7is. — There is no eversion, no flexion on lying down in young cases, but lordosis is seen on standing (Fig. 523) and in old cases, also on lying down. The main point for diagnosis is shortening. The limb is shorter, measured from the anterior superior spine, and the anterior iliotrochanteric angle (page 505) is diminished or lost ; the tip of the trochanter is above the Roser-Nelaton line, and the base of Bryant's triangle is lessened or even obliterated on the affected side. By careful palpation it can be recognized that the head is absent from its normal position beneath the femoral artery. Frequently the top of the trochanter is on a level with the anterior superior spine. The use of the X-ray is necessary to ascertain accurately the position of the head and as to whether or not the bones possess their normal shape. Rediiction. — As the head is usually more or less fixed in its abnormal position, force has to be used to replace it. Paci of Pisa was the first to reduce them systematically by a modification of the circumduction method. He flexed the thigh on the abdomen, then firmly abducted, rotating outward, and used the edge of the table as a fulcrum. Lorenz used Konig's padded, wedge-shaped block under the trochanter as a fulcrum to pry the head forward. The writer combined the direct and indirect methods by placing the child face down on a table with the aflected hip on a sand pillow and the leg and thigh hanging over the side. The operator or an assistant then raises (flexes) the knee, bringing it toward the patient's axilla, while the operator presses with his hands and body-weight down on the trochanter. By gradually raising the knee and keeping it close to the body and pushing the head forward it eventually slips from the posterior to the anterior plane and into place (Fig 524). When the head has been brought onto the anterior plane it is usually impossible to extend the knee, on account of tension of the hamstring muscles, as pointed out by Lorenz. After being reduced the thigh cannot be brought down at once to its normal position, as by so doing the head jumps out of its socket ; so it is put up algia). — Disease of the hip in its early stage is characterized by pain, limitation of motion, and limping. The pain is either a local one in the hip itself or a referred one. The hip is supplied by branches of the anterior crural, sciatic, and obturator nerves, and as these also supply the region of the knee, disease of the hip causes pains to be felt around the knee, most often on its inner side. In an early stage the limitation of motion is due to muscular contraction and it disappears under anaesthesia. The limb is held in a position of flexion, abduction, and slight external rotation. The joint is more or less rigid. The loss of motion is only complete in extreme cases. In mild cases the limitation is only present as a reduction in the normal extent of movements, the joint may move freely and without constraint over a limited arc. The abnormal changes produced are to be recognized by careful inspection, measurements, and comparison with the opposite healthy limb. Attitude.— 0\\\r\g to the pain in the affected Hmb the weight of the body is borne mainly on the healthy limb. Viewing the patient anteriorly in an early case of the disease the external rotation is readily seen in the eversion of the foot. If the foot itself is normal, rotation takes place at the hip-joint and not at the knee or ankle ; therefore a foot that is abnormally turned out indicates that there is something 'in the hip to cause it to turn out. The affected limb is seen to be held in a position of abduction, out away from the healthy one. The flexion is evidenced by the affected limb being placed a litde in advance of the other and bv the bending at the groin. If the feet are placed together there may also be flexion of the knee (Fig. 525). Tilting of the pelvis may or may not be apparent, but it exists and can be demonstrated by a careful examination. Viewed posteriorly, besides the position of the limb as seen from in front, there is in addition a change in the gluteal folds and buttock. The gluteal fold on the affected side is lowered in position and shorter than on the healthy side and the buttock is flattened. The flattening of the buttock is caused by the flexion of the hip. This flexion likewise tends to obliterate the gluteal fold. The difference in height of the gluteal folds is caused by the tilting down of the pelvis on the affected side. An inequality in the lower limbs, whether due to shortening or to malposition, such as flexion, will be visible at once by an inequality of the gluteal folds, one being higher than the other. Flexion deformity is recognized when the patient is standing by the bending at the hip-joint and by the lordosis or hollowing of the back. When the patient is recumbent on a flat surface and both legs are brought straight down so that both knees are in contact with the table, then if flexion is present it causes the lumbar vertebrae to arch and the back to rise from the table. If now the thigh of the affected side is elevated until the back again touches the table the degree of elevation necessary to accomplish this will be the measure of flexion. Measuroncnts. — The child being flat on its back the pelvis is to be made level by seeing that a line joining the two anterior spines is at right angles to the median line. If abduction is present the limb points away from the median line. It cannot be brought straight down parallel with the sound leg without tilting the pelvis. If measured from the umbilicus to the internal malleolus the affected leg measures more than the sound one. This is called apparent lengthening. If when both limbs are placed in the same degree of abduction and are measured from the anterior spine to the internal malleolus they measure the same, there is no real shortening. In advanced disease adduction is more common than abduction. This produces an apparent shortening, as shown by measurement from the umbilicus to the internal malleolus ; if the sound limb is placed in the same degree of adduction as the affected one, the distances from the anterior spines will show no actual shortening unless there Is a loss of bone or displacement at the hip-joint. The peh'is, instead of being tilted down on the diseased side, is tilted up. Flexion is usually more marked and the foot is usually inverted instead of everted. Hip-Abscess. — Tuberculosis of the hip probably begins in the neighborhood of the epiphyseal line of the femur and involves the joint secondarily. The epiphysis of the head begins above near the edge of the articular cartilage and runs obliquely across upward and inward- It is thus entirely within the capsule and when Fig. 525. — Early stage of coxalgia, showing the afi'ected left limb abducted, thus lowering the pelvis on that side; slightly flexed, thus obliterating the gluteofemoral fold, and slightly everted. pus forms it first perforates the articular cartilage and enters the joint and then perforates the capsule to point externally. There are three favorite places of exit, viz. : ( I ) on the posterior surface of the neck between the branches of the ischiofemoral ligament; (2) on the lower anterior surface beneath the ihopsoas tendon, between the pubofemoral and iliofemoral ligaments, through the bursa found here which may communicate with the joint ; and (3) at the cotyloid notch. The head and neck of the femur and also the acetabulum become carious. Pus may find an exit at other places besides those mentioned. It may perforate the acetabulum and show above Poupart's ligament at its outer side, or may break through the upper posterior portion of the capsule. Not often does it break through between the branches of the iliofemoral ligament. When it does break through anteriorly it points in Scarpa's triangle, commonly to the inside of the vessels; when it breaks through pos- ., . thigh. Coxa Vara. — The normal angle which the head and neck make with the femoral shaft may vary according to Humphry {Jour. Anat. and Phys. , xxiii, 236) from 1 10 to 140 degrees. Sometimes as a result of injury or disease the neck makes a more acute angle than normal, coming off at an angle of 90 degrees or less. This is called coxa vara (Fig. 526). In some cases it is due to a bending of the neck caused by softening of the bone, as in rachitic affections, or to fracture. The limb is shortened, the trochanter raised above the Roser-Nelaton line, and abduction and flexion are restricted. To rectify it Whitman's operation of wedge-shaped resection is done. A wedge of bone with a base of 2 cm. (^ in.), apex inward, is removed at a point opposite the lesser trochanter. The femur is then placed in abduction and the bone allowed to heal. When the limb is brought down the angle of the head and neck will be much increased and the deformity and disability will have been removed. been applied to the opposite condition, when the neck is nearly parallel with the shaft ; it is rarer and of less importance than is coxa vara. Orthopaedists regard 135 degrees as the normal limit of the angle between the neck and shaft of the femur, but Humphry placed it at 140 degrees. Fig. 526. — Normal angle of the head and neck to the shaft of the femur with the alteration in position in coxa valga and coxa vara shown, by dotted lines. The operations on the hip are usually done either for hip-disease or congenital luxations. More rarely traumatic or pathological luxations or intracapsular fractures may be operated on. The joint may be approached either anteriorly or laterally. Lateral operations are the more mutilating, while anterior ones are often sufficient and less serious. Lateral Operations. — In approaching the joint from the side the incision of Langenbeck is preferred. It begins well up on the buttocks on a line with the posterior superior spine (page 500) and is continued down over the great trochanter in the axis of the thigh. If made with the limb flexed the line of incision will be straight. The muscular fibres and tendon of the gluteus maximus are cut in the line of the incision. This exposes the posterior edge of the gluteus medius, which is to be pulled forward, and the pyriformis, which is to be drawn backward or loosened from its insertion into the trochanter. The capsule can then be incised and the joint examined. Further exposure may be obtained by loosening the gluteus medius and gluteus minimus from their insertion in the top of the trochanter and pushing them forward. The hgamentum teres is often destroyed by the disease. Removal of the head of the femur enables the acetabulum to be examined and carious bone curetted away if necessary. The incision through the gluteus maximus muscle will be almost parallel to its fibres and near its anterior edge. Care is to be taken not to go too high up between the pyriformis and gluteus medius because the main trunks of the gluteal artery and superior gluteal nerve make their exit there from the great sacrosciatic notch. The principal bleeding will come from branches of the gluteal artery descending from that point. This operation is practically limited to cases of extensive caries in which it is desired to do a radical operation (Fig. 527). Boeckmann, of St. Louis, made a large horseshoe-shaped flap over the greater trochanter. Its base was upward and it consisted of skin and superficial fascia. This flap was raised and a chain-saw passed underneath the muscles inserting into the top parts involved. of the greater trochanter, and the latter was then sawed of? and turned up as a flap. This exposed the upper surface of the head and neck of the femur. The operation was done for intracapsular fracture, the fragments being pinned together with ivory pegs and the trochanter brought down and again fastened in place with ivory pegs. The skin-flap was also brought down and sutured. While good exposure can be obtained by this method, it is almost too severe and has not been generally adopted. Lorenz, in congenital luxations, incised from the anterior superior spine down and out toward the trochanter. The tensor fasciae femoris is pushed forward and the glutei muscles backward. Hoffa modified this operation by making his incision along the anterior edge of the greater trochanter. As the hip-joint is nearer the anterior than the lateral surface of the body we believe it to be better to approach it from the front rather than from the side. Anterior Operations. — Lucke made an incision from just below the anterior superior spine running downward and inward along the inner margin of the sartorius. The sartorius and rectus muscles were displaced outward and the ilioosoas inward. Hiiter, Parker, and Barker made the incision directly downward from the anterior superior spine and pulled the sartorius and rectus inward and the tensor fasciae femoris and gluteus medius and minimus outward (Fig. 528). The method of Hiiter, Parker, and Barker, is not difficult. The only vessel encountered is a branch of the external circumflex. One should not go too low, or some muscular branches of nerves going to the vastus externus will be wounded. No muscles are divided. The writer has used this method with satisfaction in cases of hip disease and intracapsular fracture. If additional room is desired the fascia lata may be divided laterally and the tensor fasciae femoris and gluteus medius muscles may be detached from the spine of the ilium and back along the crest, as done by Codivilla. They are to be again sewed back into place before closing the wound. muscle was then drawn downward and the pectineus upward and the joint exposed. The writer prefers to make an incision along the inner side of the femoral vein. The vessels are then to be drawn upward and outward and the pectineus downward and inward and the capsule is at once evident. The blood-vessels and nerves not only supply the structures of the thigh itself, but also serve as channels for the transmission of blood and nervous impulses to and from the parts beyond, hence their large size. composed of the rectus feino7'is, vastus inicrnus, vastiis extermis and crureus {vastus intermedins), and we might add also the sartorius. The quadriceps of the thigh is homologous with the triceps extensor of the arm, the fourth head of the latter muscle being the anconeus. The sartorius normally has no homologue in the upper extremity, but is sometimes represented by a slip from the latissimus dorsi to the triceps (dorsiepitrochlearis — MacaUster). The rectus arises by an anterior or straight head from the anterior inferior spine of the ilium and a posterior or reflected head from the upper surface of the rim of the acetabulum. The tendon formed by the union of these two heads passes downward directly over the head of the femur and, in operating on the joint from in front, it must be deflected to one side. The belly of the muscle is separate and not attached to the other muscles (Fig. 529). The vastus externus (vastus lateralis) forms the muscular mass on the outer surface of the thigh. A bursa separates it from the gluteus maximus above. Superficially it is readily separated from the crureus (vastus intermedius) but blends with it close to the bone. The line separating the two muscles is directly upward from the outer edge of the patella. The vastus internus (vastus medialis) arises from the inner edge of the linea aspera as high up as the lesser trochanter. Its outer edge blends with the crureus. The sartorius in the middle third of the thigh lies directly over Hunter's canal. It inserts into the tibia below and internal to its tubercle, hence it spans both the hip-joint and knee-joint. It flexes the thigh on the pelvis and the leg on- the thigh. It also rotates the thigh outward and the leg inward especially when the latter is flexed. biceps cruris, the scniitendinosus, and the seminienibranosus. The short head of the biceps arises from the outer lip of the linea aspera. Above, the long head is blended with the semitendinosus and arises from the great sacrosciatic ligament and the lower inner part of the tuberosity of the ischium. The semimembranosus arises from the tuberosity just above and external to the biceps and sernitendinosus. The biceps, arising by its long head from the tuberosity, lies first to the inner side of the sciatic nerve, and then, as it crosses obliquely to reach the The adductor muscles are the adductor brevis, adductor longiis, adductor magnns, and gracilis ; for chnical purposes the pcctineiis may also be included, although it is morphologically simply a detached portion of the iliacus. The quadratus femoris and obturator extcrnus belong morphologically to the adductor group, but from a clinical standpoint they are associated more with the external rotators of the hip than the adductors of the thigh. The adductor muscles separate the flexor and extensor groups on the inner side of the thigh. The adductor longus arises by a strong tendon from the body of the pubis just below its spine and inserts into approximately the middle third of the femur in the linea aspera (Fig. 531). When the thigh is abducted the tense edge of its tendon is evident, and if followed upwards it leads to the spine of the pubis. It lies on the same plane as the pectineus, which is immediately above; sometimes, especially in the female, an interval exists between the two through which the adductor brevis may be visible. Near its insertion it forms part of the floor of Scarpa's triangle and the upper part of the floor of Hunter's canal. The adductor brevis arises from the descending ramus of the pubis just below the origin of the adductor longus and inserts into the femur from the lesser trochanter to the linea aspera. It lies directly behind the upper portion of the adductor longus and in front of the adductor magnus. The adductor magnus arises from the ramus of the ischium, from the adductor brevis in front to the hamstring tendons on the tuberosity behind. It is inserted into nearly the whole length of the linea aspera, and by a distinct tendinous band into the adductor tubercle at the upper edge of the internal condyle. Its upper portion is sometimes called the adductor minimus. It is pierced near the bone by the perforating branches of the profunda femoris artery and near its lower portion by the femoral artery and vein. It forms part of the floor of Hunter's canal. Its homologue in the upper extremity is the coracobrachialis muscle. The gracilis arises from the pubis just to the inner side of the adductor brevis and passes straight down the thigh to insert into the tibia, beneath the sartorius and above the semitendinosus. It is sometimes represented in the upper extremity by a slip from the lower border of the pectoralis major called the chojidro-epitrochlcaris. If the thigh is flexed and rotated outward the sartorius is seen crossing it obliquelv, and Scarpa's triangle is evident as a depression downward from Poupart's ligament. The muscular mass of the upper inner portion of the thigh is composed of the gracilis and adductor muscles. Immediately above the patella is the flat tendon of the rectus, and above and to the inner side of the patella is a rounded mass formed by the vastus internus (Fig. 532). Running upward and inward from the outer edge of the patella to the middle of the thigh is a groove which separates the rectus and vastus externus. On the outer side a flat groove is formed by the iliotibial band of the fascia lata. At its posterior border is the external intermuscular septum between the vastus externus and biceps. Scarpa's Triangle. — This occupies approximately the upper third of the thigh. Its base is formed by Poupart's ligament, its outer side by the sartorius muscle, and its inner side by the adductor longus. Its floor is formed by the iliacus, psoas, pectineus, sometimes a portion of the addiictor brevis, and the adductor longus muscles. It contains the femoral artery and vein, the anterior crural nerve, the long saphenous vein, and numerous lymphatics (Fig. 533). At its upper and inner part is the saphenous opening, at which femoral herniae make their appearance. Psoas abscesses follow the tendon of the psoas muscle down and make their appearance in Scarpa's triangle, sometimes to one side and sometimes to the other of the artery. Pus from hip-joint disease likewise comes to the front at the upper part of the triangle on one side or the other of the femoral artery. The apex of Scarpa's triangle is a favorite site for ligation of the femoral artery. Femoral Artery. — The line of the femoral artery is from a point midway between the anterior superior spine and the symphysis pubis (this brings it to the inner side of the middle of Poupart's ligament J to the adductor tubercle at the inner upper part of the internal condyle. Just below Poupart's ligament it gives of! four small branches; the superficial external circumflex, superficial epigastric, and superficial and deep external pudic. About 4 cm. ( i yi in. ) down it gives off the profunda femoris, which is almost as large as the parent trunk. On reaching the edge of the sartorius it passes beneath it to enter Hunter's canal, and at the junction of the middle and lower third of the thigh it pierces the adductor magnus to become the pophteal. At Poupart's ligament the femoral vein lies to the inner side of the artery, but at the apex of the triangle it lies behind it. Ligation of the Femoral Artery. — In ligating the femoral artery an incision is made in the line given above, and the artery sought for beneath the fascia lata. Ligatures are not placed high up, on account of the proximity of the deep femoral; lower down at the apex of the triangle is the preferred point. The crural branch of the genitocrural nerve lies on the artery for a short distance below Poupart's ligament; it is small in size. Just to the outer side of the artery, and sometimes touching it, is the anterior crural nerve, and running down its outer side are the internal cutaneous and internal saphenous branches. The femoral vein, which above was internal to the artery, at the apex of the triangle lies posterior to it (Fig. 534). The profunda femoris artery comes off 4 cm. (ii< in.) below Poupart's ligament. Its branches are the external (lateral) and internal (medial) circumflex, and four perforating. The last perforating is terminal. The external circnmflex passes outward over the iliacus and under the sartorius and rectus and divides into three branches; the ascending branch follows the anterior intertrochanteric line and gives off a branch which enters the joint between the limbs of the iliofemoral or Y ligament. The transverse branch goes outward to the upper part of the vastus externus; and the descending branch supplies the muscle lower down. The ascending and transverse branches lie beneath the incision, which is made in operating on the hip-joint anteriorly, and may be cut during the operation. The internal circumflex winds inwardly between the psoas and pectineus, then between the adductor brevis and obturator externus, and then between the adductor magnus and quadratus femoris to anastomose with the external circumflex, sciatic, and superior perforating. The ionx perforating arteries wind around close to the bone from within outward and terminate in the hamstring and vastus externus muscles. They perforate the adductor muscles and send large anastomotic branches to one another near the linea aspera. In operations on the femur, when the soft parts are detached from the posterior portion of the bone, the bleeding from these perforating branches is liable to be very free and on account of their depth difficult to control. It is this which renders operations like those for ununited and compound fractures dangerous. Hunter's Canal. — Hunter's canal occupies approximately the middle third of the thigh. It has an outer wall formed by the vastus internus muscle; a floor formed above by the adductor longus, and below by the adductor magnus; and a roof formed by a layer of fascia running from the adductor longus and magnus below to the vastus internus on the outer side. The canal runs from the apex of Scarpa's triangle to the opening in the adductor magnus muscle. The sartorius muscle lies on the roof of the canal (Fig. 533). The Femoral Artery in Hunter s Canal. — The femoral artery in Hunter's canal has the vein, to which it is closely bound by fibrous tissue, first posterior and then slio'htly to its outer side. The internal or long saphenous nerve crosses the artery in front from its outer to its inner side. At the beginning of the canal the nerve to the vastus internus runs alongside of the long saphenous nerve, but it soon leaves it to enter the muscle. The long saphenous nerve leaves the artery as the latter perforates the adductor magnus and passes downward under the sartorius muscle to "be distributed to the leg lower down, and to the inner side of the ankle. Ligation of the Femoral Artery in Hnnter s Canal. — In ligating the artery the incision is made over the sartorius muscle, which is to be pulled to the outer side; this exposes the roof of the canal, which is then opened. There is no need of including the long saphenous nerve in the ligature. Just before the femoral artery pierces the adductor magnus it gives off the anastomotica magna, whose superficial branch follows the long saphenous ner\'e, while its deep branch supplies the \-astus internus muscle. This latter branch may be the source of troublesome hemorrhage in supracondylar osteotomy. Collateral Circulation. — After ligation of the femoral artery below its profunda branch the external circumflex artery anastomoses with the muscular branches of the femoral, anastomotica magna, and superior articular arteries. The perforating arteries anastomose with the muscular branches below the ligature and with the superior articular arteries (Fig. 535). Long or Internal Saphenous Vein. — The long saphenous vein begins in the venous arch on the dorsum of the foot and passes upward Just in front of the internal malleolus, then along the inner posterior edge of the tibia, accompanied by the long saphenous nerve, then along the posterior border of the internal condyle and up in almost a straight line to the saphenous opening, 4 cm. (_ i ^ in. ) below and to the outer side of the spine of the pubis, where it empties into the femoral vein. It is this vein which is involved in varicose veins of the leg, and is frequently operated on. The blood from the inner and outer portions of the thigh collects into two veins which empty into the long saphenous before the saphenous opening is reached, or else join the \ein at the saphenous opening, or else open separately mto the femoral vein. There are then sometimes two Or three veins at the saphenous opening coming from below, instead of one. This is important to bear in mind when operating here, otherwise one of the side veins may be ligated or excised under the impression that it is the main trunk. Every opportunity should be utilized to impress on one's rnind the exact course pursued by the vein, as otherwise it may not be readily found if not rendered conspicuous by distention or disease. Lymphatics of the Groin. — The lymphatic nodes of the groin are frequently the seat of infection necessitating operative measures. They are superficial and deep. For clinical purposes there is no better division of the superficial nodes than into an oblique set along Poupart's ligament and a longitudinal set along the blood-vessels (Fig. 536). While as a general rule it may be stated that the nodes drain the region they are nearest to, this is frequently not the case. Therefore it is not always possible to infer the source of the infection from the location of the infected lymph node. The nodes of the groin drain the lower anterior half of the abdomen, the genitalia, lower limb, and the anal, gluteal, and lumbar regions. They vary from 10 to 20 in number, and their efferent vessels either pass through the femoral canal to the nodes inside of the abdomen, or may terminate in the deep lymphatic nodes of the femoral canal. ' The deep lymphatics consist of one to three nodes in the femoral canal internal to the femoral vessels. They are not constant, and one which is sometimes found at the upper end of the femoral canal is known as the gland or node of Cloquet. They receive the deep lymphatics of the thigh, as well as sometimes a communication from the superficial lymphatics. They rarely become the seat of infection, but if inflamed may be mistaken for strangulated femoral hernia. Excision of Inguinal Nodes. — The inguinal nodes frequently become inflamed and swollen (bubo) from infection transmitted from the parts which they drain. For this they are frequently excised. The superficial nodes are located on the fascia lata around the saphenous opening, and at that point are intimately associated with and surround the veins. On this account it is easy to wound the veins, and the hemorrhage may be so free and so hard to control as to endanger the life of the patient. I know of one such fatal case. This accident is to be avoided by freeing the edge of the mass below the saphenous opening and isolating the long saphenous vein, which is then followed up and exposed at its entrance into the femoral vein. The diseased mass is then to be dissected loose from each side, away from the vein, and removed. The fenjoral vein itself at this point is superficial, and if the saphenous opening is cleaned out it will of necessity be exposed. The other veins emptying into the femoral at the saphenous opening above the long saphenous — the superficial circumflex iliac, epigastric, and external pudic- — are usually too small and easily secured to cause trouble. Sciafic Nerve. — The sciatic nerve in its descent crosses a line joining the tuberosity of the ischium and greater trochanter at the junction of its inner and middle thirds. It then descends toward the middle of the popliteal space. It di\'ides into the internal and external popliteal nerves at about the middle of the thigh (Fig. 537). Rarely it divides lower down, but more frequendy higher up. It is said that it will bear a weight of 183 lbs., but Symington {Lancet, 1S78 — Treves) has pointed out that it \yill tear out from its spinal attachment before this limit is reached. In exposing it the incision should be made high up at the gluteal fold, to the outer side of the tuberosity of the ischium. At this point it lies to the outer side of the biceps and on the adductor magnus; a little lower down it disappears beneath the biceps, and, if the incision is made here, the muscle must be displaced and it may only be found with dilificulty. Fig. 536. — Superficial lymphatic vessels of lo\Yer limb; semidiagrammatic. (Based on figures of Sappey.) Sciatica may be caused by injury to the sacral plexus in the pelvis, as by labor, or by injury to the nerves as they issue from the spine, as in fractures, luxations, bony outgrowths or tumors. The pain affects the back of the thigh and outer side of the leg. and unsatisfactory in treatment. The signs peculiar to this fracture are due to the displacement of the fragments. Some shortening occurs in all fractures of the femur (Fig. 538). Comparative measurements to ascertain this will be of no value if the pelvis is tilted (see page 497). If by measurement the limb is shorter than the opposite one, then if the dfstance from the tip of the greater trochanter to the external malleolus is the same on both sides, the injury must be higher up, or in the neck. Fig. 538. — Intracapsular fracture of the neck of the femur showing the shortening. The dotted Hne represents the outline of the normal bone. Fig. 539. — View of the outer surface of the bones of the hip, showing Roser-Nelaton line (ad); Bryant's triangle (a be — be being its base) ; the iliotrochanteric line (a c) and iliotrochanteric angle {bac). base of Bryant's triangle will be shorter on the injured side (Fig. 539). If the extended limb is rotated the arc described by the greater trochanter will be smaller on the injured side because the shaft rotates on its axis instead of rotating in the acetabulum. The trochanter of the injured side is usually not so prominent as on the sound side. The iliotibial band is relaxed. the knee of the sound side will be found to be higher than that of the injured one. In all fractures of the thigh the foot is placed by gravity in eversion. The rise of the greater trochanter, being nearer to the crest of the ilium, produces a slight fulness in the outer portion of Scarpa's triangle which is absent on the healthy side. Line of Fracture. — The neck is fractured in one of two places, near the head, or near the trochanter. The former is intracapsular entirely, the latter partly intracapsular and partly extracapsular. As the capsule anteriorly descends as low as the intertrochanteric line and posteriorly only half way down the neck, the high fractures are entirely intracapsular and the low fractures intracapsular in front and extracapsular behind. This causes a marked difference in healing; complete intracapsular fractures do not unite firmly, but the fractures close to the trochanters not infrequently unite firmly with resulting good function. Impaction. — Impaction of the other fragment by the neck of the bone is not rare, and firm union may occur. If the fracture is close to the head, the neck is impacted into and penetrates the head, but if the fracture is close to the trochanters the neck penetrates the trochanters, frequently splitting them. gastrocnemius Mode of Injury. — In old people the bone is weakened by atrophy and the neck is often fractured by indirect violence, as by twisting, etc. Then the fracture is a high one; if, however, the fracture is by direct violence, as by falling and striking the hip, then the fracture is apt to be close to the trochanters and the prognosis better. Hence the importance of ascertaining the history of the injury. Fracture also occurs in young adults and children, usually from direct injury. Treatmeyit. — The injury is treated ( i ) by widely abducting the thigh, which elevates the lower fragment to the upper; (2) by adhesive plaster extension combined with lateral weight traction pulling the upper part of the thigh out, which renders tense the capsule and so brings the fractured surfaces in apposition; or (3) by Thomas's splint which is of metal and extends from the level of the axilla to below the knee; this ensures immobility and facilitates handling of the patient. chanters.— This is almost always the result of a direct injury or blow on the hip. Impaction is almost the rule, the upper fragment being driven into the lower. Shortening and other symptoms are usually not so marked as in the other fractures and almost any method of treatment is followed by good results. These may be in the upper, middle, or lower third. They all have a common displacement. The upper fragment is displaced forward and outward and the lower fragment backward and usually inward. The foot is usually everted. Fractures of the Upper Third. — The displacement of the upper fragment forward and outward is usually marked. It is caused by the iliacus, psoas, and pectineus pulling it forward and rotating it out and the gluteus minimus and medius abducting it. The lower fragment is pulled in by the adductors and posteriorly by the gastrocnemius and plantaris (Fig. 540). This is a troublesome fracture and is treated either by a double inclined plane or anterior wire spHnt with the limb in a flexed and abducted position or else the fragments are to be wired or pinned together. the leg abducted. Fractures of the Lower Third — Supracondylar. — This is a particularly dangerous fracture because the lower fragment is drawn backward by the gastrocnemius and plantaris, and the popliteal vessels and internal popliteal nerve may either be wounded primarily or stretched over its sharp upper edge (Fig, 541). The artery lying deepest is the most liable to injury, then the vein, and finally the nerve. Gangrene necessitating amputation has occurred. Of course in attempting to replace the fragments the knee should be flexed to relax the gastrocnemius and plantaris. Some cases can be treated by ordinary extension with the knee straight, others with the knee flexed, but others may require operation and fixing by pins or wiring. William Bryant divided the tendo Achillis for the purpose of relaxing the pull of the gastrocnemius. Fig. 541. — Supracondylar fracture of the femur. The lower fragment is seen to be drawn back into the popliteal space by the gastrocnemius and plantaris. The vessels are stretched over the sharp edge of the lower fragment. AMPUTATION. Amputation at the Hip-Joint. — In amputating- at the hip-joint, hemorrhage is especially to be guarded against. This comes from two sources, the femoral artery anteriorly and the branches of the internal iliac posteriorly. The most reliable way of controlling bleeding is probably by the use of the elastic tourniquet held in place by WyetJi s pins. These are two steel pins 5 mm. Ty^ in.) in diameter and 25 cm. (loin. )long. One is entered 6 mm. {y{ in.) below the anterior superior spine and slightly to its inner side and traverses the tissues on the outer side of the hip for about 7.5 cm. (3 in.) from the point of entrance; the other is entered through the skin and tendon of the adductor magnus 1.25 cm. ()^ in.) below the perineum and made to emerge 2.5 cm. (i in.) below the tuber ischii. The elastic tube is to be wound around the hip above the pins, which prevent its slipping down (Fig, 542). The amputation is then performed as desired. Compression of the aorta or common iliac by instrumental means is obsolete. Sometiuies the common iliac is compressed laterally by the linger introduced through an incision in the in some operations the head of the femur is disarticulated before the flaps are made. In this case the first part of the operation is like a resection of the hip by the Langenbeck straight incision. obturator, and internal pudic arteries, derived from the internal iliac. Amputation of the Thigh. — In amputation of the thigh by the flap method care must be taken to avoid splitting the femoral artery. Its position in the various portions of the thigh should be borne in mind. Anteroposterior flaps are to be preferred to lateral ones, and a short anterior flap is to be avoided because the scar is drawn posteriorly (Fig. 542). The muscles of the posterior part of the thigh, the hamstrings, are not attached to the bone, with the exception of the short head of the biceps, they therefore retract when cut and later pull the scar behind the bone. The crureus and vastus externus and internus anteriorly are attached to the bone, and hence cannot draw back either at the time of the operation or afterwards. The position of the femoral artery will depend on the point at which the amputation is made. It does not lie close to the bone until the popliteal space is reached. Bleeding from the perforating arteries along the linea aspera should, however, be looked for and the sciatic nerve should be isolated and cut short. The patella is pointed below where the tendo patellae is attached, is slightly convex on its upper border, and its lateral edges are prominent, especially the outer. It usually has little tissue over it. With the limb extended and quadriceps relaxed the patella can cle is contracted the tense tendo patellse becomes evident, when relaxed the soft fatty pad beneath the tendon can be felt. patella and tubercle of the tibia on each side can be felt a groove which indicates the line of the joint and the location of the semilunar cartilages. On the outer side posteriorly opposite the level of the tibial tubercle can be felt the head of the fibula. Running upward from it is the tendon of the biceps. In front of the biceps can be seen and felt the iliotibial band. It is difficult to distinguish the joint-line on the sides, therefore it is better to locate it by recognizing the sulci anteriorly on each side of the tendo patellse; flexing the knee makes these depressions more distinct. The joint on the outer side is about 2 cm. (^ in. ) above the head of the fibula. tended, the condyles of the femur can readily be outlined; the inner is the more prominent. The upper edge of their articular surfaces can be felt on firm pressure at the sides, and the inner leads to the adductor tubercle, into which the adductor magnus tendon is inserted — this tendon can likewise frequently be felt. The tubercle of the tibia can best be seen and felt when the tendo patellae is relaxed. It is about 4 cm. (i}4 in.) below the patella. Just above and to its outer side, about 4 cm. (ij4 in.) distant, is the external tuberosity of the tibia; into it is inserted the lower end of the iliotibial band. To the outer side at a little lower level can be seen and felt the head of the fibula. On the inner side is the flat rounded internal tuberosity of the tibia. Posteriorly is seen the fulness of the popliteal space; on its outer side the tendon of the biceps is readily felt and running with it is the external popliteal As the functions of the lower extremity are support and mobility, it is evident that in order to obtain mobility without unduly weakening the limb the ligamentous connection of the bones must be exceptionally strong. The knee is placed half way down the extremity, hence it has the bulk of the body above to support ; also, the bones on each side of the joint are the longest in the body, hence their lever action is exceptionally great, which likewise necessitates that the joint be firmly braced by ligaments. degrees) and flexed until the thigh and upper portion of the leg come in contact, at about 45 degrees or even less. The movement is a combined gliding and rolling one. According to Morris (" Joints," p. 375), as extreme extension ends the leg rotates a little outw^ard through a longitudinal axis, passing through the middle of the outer condyle of the femur, and as flexion begins it rotates inward. These rotatory movements are, however, slight, and may practically be ignored. When flexion has proceeded to 1 50 or 155 degrees, the joint becomes comparatively loose, and this increases as the joint is flexed, until a rotation of 36 degrees (Morris) is allcvved. This is of decided practical importance because injuries and treatment are intimately associated with the presence of rotatory movements. No rotation is possible when the knee is fully extended, the bones being then immovable. The knee-joint is between the femur, the tibia, and the patella; the fibula does not enter into it (Fig. 544). The patella is only a sesamoid bone developed in the quadriceps tendon, and is not essential. In some of the lower animals it has a synovial membrane separate from the knee-joint proper. The joint between the femur and tibia is built up of two separate lateral " parts; the condyle and tuberosity of each side forming practically a separate joint and having a crucial ligament as one of its lateral ligaments. The object of thus combining two joints side by side to form one joint is to add to its strength and lateral stability. The condyles of the femur have their articular surfaces prolonged up on its anterior surface, not to aid in flexion and extension, but simply to facilitate the action of the patella. The outer condyle is the higher, to prevent external luxation of the patella. Patella The articular surfaces of the condyles are not perfect arcs of a circle. If they were the motion would be solely a gliding- one and the lateral ligaments and crucial ligaments would be equally tense in all positions, which is not the case, for, particularly in flexion, they become slighdy relaxed. The upper surface of the tibia is slighdy hollow and its spine projects upward between the condyles, thus adding to the lateral stability of the joint. The patella is divided by a longitudinal ridge into two articular facets, the outer for the external condyle being the larger; the ridge lies in the intercondylar space. The inner part of the patella is thicker than the outer because tures, the torn fibrous fringes are never on the articular surface but always on its superficial surface. The patella has its that subluxations take place. The knee possesses the usual capsular ligameiit but so hidden by strengthening bands and tendinous expansions that but little of it is seen. Anteriorly the capsule is strengthened by the tendon of the quadriceps, the patella, and the tendo patellae (Fig. 545). Viewing these structures as a whole we see that their lower end is firmly attached at the tibial tubercle, but above their attachments are far removed from the joint. They are so strong and thick that pus from within does not tend to go through but goes around them. Their upper attachment is muscular, so they do. not act to restrain movements except when the muscle is contracted; hence flexion is limited by contact of the soft parts posteriorly rather than by tension of the ligaments anteriorly. In complete extension the bulk of the patella rises above the articular surface, and connecting its upper edge with the anterior surface of the femur is only the thin capsular ligament, hence effusions into the joint bulge upward at this point. Extending about 5 cm, (2 in.) above the patella is the subfemoral bursa; this in 8 out of lo cases coirmunicates with the joint, and effusions readily distend it. The patella normally lies in contact with the femur but when there is effusion in the joint it is pushed or raised up and is called a floating patella. Pressure on it causes it to strike on the femur beneath, which is readily felt and enables one to diagnose effusions within the joint. Posteriorly the capsule is thick, being strengthened by an expansion, called the posterior ligament or ligamentum Winslowii, which goes upward and outward from the tendon of the semimembranosus rnuscle at the upper edge of the tibia. It is pierced by the branches of the azygos articular artery. The capsular ligament is weak below at the margin of the tibia and here pus may find an exit. It is less liable to come out above, but the bursa under the inner head of the gastrocnemius frequently (17 per cent., Mac- lunar cartilage Fig. 546. — ^View of the inner side of the kneejoint; the capsule has been cut away from the edge of the patella to the internal lateral ligament, exposing the interior of the joint. Fig. S47. — View of the outer side of the knee-joint. The capsule has been cut away from the edge of the patella to the external lateral ligament. alister) communicates with the joint and is usually the origin of the ganglion so often seen in the popliteal region. When the joint becomes subluxated by disease the tibia is drawn backward and this posterior capsular ligament may shorten and prevent reposition forward. So strong is it that forcible attempts are liable to cause fracture. Internally the capsular ligament is strengthened by the lateral expansion from the side of the patella and from the fascia lata over the vastus internus; these go to the inner tuberosity of the tibia and strengthen the lower part of the joint, Internal Lateral Ligament. — A band of the capsule to which the name internal lateral ligament has been applied runs from beneath the adductor tubercle to the tibia below the internal tuberosity; it is strengthened by fibres from the tendon of the semimembranosus and has the internal articular vessels and nerves passin-^ between it and the tibia. It will be noted that it lies toward the posterior portion of the joint, hence it limits extension (Fig. 546; . Externally the capsule has likewise the fibrous expansion of the quadriceps from the side of the patella and the fascia lata. This latter is the strong iliotibial band and goes downward to insert into the outer tuberosity of the tibia TFig. 547). There are likewise two band-like ligaments on the outer side, the long and short external lateral ligaments. The long external lateral ligament arises from a tubercle just below and in front of the outer head of the gastrocnemius muscle. It is about 5 cm. (2 in.) long and is attached below to the fibula, anterior to its styloid process. It is embraced on each side by the split tendon of the biceps. Beneath it pass the popliteus tendon in its sheath and the inferior external articular vessels and nerve. Note that this is likewise at the posterior portion of the joint and therefore it too limits extension. The short or posterior of the two external lateral ligaments is often not to be recognized as a distinct structure, it passes from the styloid process of the fibula over the popliteus tendon to blend W'ith the posterior capsular ligament on the external condyle. The lateral ligaments check extension and outward rotation of the tibia. Crucial Ligaments. — These pass from the tibia, the anterior being attached in front of and the posterior behind the spine, upward to the intercondylar notch of the femur. The anterior or external passes upward, outward, and backward. The posterior or internal passes upward, inward, and forward (Fig. 548 j . They are never very lax in any position of the joint, but the anterior is most tense in extension and the posterior in flexion. The anterior tends to prevent displacement of the tibia forward and the posterior ligament displacement of the tibia backward. The posterior crucial ligament blends with the posterior capsule and in resecting the knee care should be taken in dividing this ligament that the popliteal artery is not wounded. A ligamentous band runs from the posterior crucial ligament to the external semilunar cartilage ; it is called the ligament of Wrisberg. The knee-joint in some of the lower animals is composed of two separate joints, one for each condyle, and the crucial ligaments of man are simply the remains of lateral ligaments when separate joints exist. They check inward rotation. Semilunar Cartilages, Coronary a)id Transverse Ligaments. — The semilunar cartilages are used to deepen the joint in the same manner as the cotyloid of the hip and glenoid of the shoulder. It is their method of attachment that is important. The external is nearly circular, the internal is semi-elliptical. The ends are fibrous and are attached in front of and behind the spine of the tibia. The transverse ligament is a band passing across the front from one semilunar cartilage to the other (Fig. 549) " As Macalister has pointed out, there is no true coronary ligament. It is the part of the capsular ligament running from the semilunar cartilages to the tibia. The semilunar cartilages are attached by their outer edges to the capsular ligament. This attachment is less in extent in the case of the external, because its outer surface is obliquel}^ grooved by the tendon of the popliteus muscle, but it has an additional attachment in the ligament of Wrisberg, as stated under the posterior crucial ligament. Humphry ("Human Skeleton, ' ' 546) has pointed out that the semilunar cartilages in flexion and extension move with the tibia, but in pronation and supination (rotation) move with the femur. S7(m. — Below the patella is a pad of fat extending under the upper portion of the tendo patelke; a bursa is under the lower portion. Passing up from this pad to the intercondyloid notch and crucial ligaments is the ligamentum mucosum; below, it is continuous with the synovial fringes at each side of the lower edge of the patella which form the ligamenta alaria. the ligamentum teres does for the hip, viz. : act as a swab to distribute the synovia over the articular surfaces. are a number of bursse about the knee-joint, but they are not all of importance. Anteriorly there are the prepatellar, suprapatellar, and deep and superficial infrapatellar. The /';r/>(7/<'//<7r bursa lies in the subcutaneous tissue between the skin and patella. It is often enlarged, constituting "housemaid's knee" (Fig. 550). The bursa is almost always present, but often irregular in shape and character. Injuries frequently cause it to inflame, as do also rheumatoid affections. Sometimes the tendon of the quadriceps over the patella is ossified clear to the surface, which is often irregular and rough, and is felt immediately beneath the skin with apparently no subcutaneous tissue intervening. In these cases the bursa may be very irregular or loculated in shape, or there may be more than one. The sac of the bursa is usually very thin, but becomes thick and distinct as the result of irritation. Excision is usually the quickest way of curing housemaid's knee, but often the easier way of simple incision and drainage with a wick of gauze is sufficient. The suprapatellar or subfemoral bursa extends from 5 to 7.5 cm. (2 to 3 in.) above the patella beneath the crureus muscle. It is liable to be injured by stabs or punctures, and thereby infect the joint with which it communicates in 8 out of 10 cases. It becomes distended in intra-articular effusions. The infrapatellar burses are one between the skin and tibial tubercle and the other between the under surface of the tendo patellae and the upper end of the tibia — they are unconnected with the joint and are not often diseased. Posteriorly. — On the outer side of the joint there may be present (i) a bursa beneath the external head of the gastrocnemius which may communicate with the bursa between the popliteus tendon and external lateral ligament. (2) One between the biceps tendon and external lateral ligament, (3) another between the popliteus tendon and external lateral ligament, and (4) one beneath the popliteus, usually an extension of the synovial membrane of the joint. On the inner side : (i) one beneath the internal head of the gastrocnemius, which usually communicates with the joint and sends a prolongation between the gastrocnemius and the semimembranosus. This is the most important posterior bursa. (2) There is one beneath the tendons of the sartorius, graciUs, and semitendinosus muscles. (3) One beneath the tendon of the semimembranosus, between it and the tibia; it rarely communicates with the knee-joint. (4) One between the tendons of the semimembranosus and the semitendinosus. Ganglion. — Sometimes a rounded tumor that is called a ganglion appears in the popliteal space. When the knee is flexed it is felt as a round, movable tumor which is hard and cystic. If the knee is extended it slides inward to the edge of the inner condyle and becomes hard and fixed. It usually originates from the bursa beneath the inner head of the gastrocnemius, is prolonged between it and the semimembranosus, and, when the knee is flexed, it either disappears entirely by its contents going into the joint or it can still be felt in the popliteal space. It may be a difficult matter to excise these cysts on account of their ramifications, and when this is impossible it is better to open them up, clean them out, and then sew the wound shut in order to avoid infecting the joint. Care should be taken not to mistake them for solid tumors or enlarged lymph-nodes, both of which are less common than ganglion. Fracture by hidirect Violence. — As pointed out by Humphry, when the knee is fully flexed only the upper third or fourth of the articular surface of the patella is in contact with the condyles of the femur — the remaining two-thirds or three-fourths of the projecting portion of the bone resting on the pad of fat. When semi-flexed the greater part of its surface is in contact with the condyles, or at least the whole of its middle third. In full extension only the lower third or fourth or even less remains in contact. When semi-flexed the patella is subjected to the greatest leverage strain; hence it is that fractures most often occur in this position and that the fracture occurs so frequently at the junction of the lower and middle portions. When the bone is fractured by indirect force (muscular) the line of fracture traverses its whole thickness and consequently the joint is always involved. Usually there are but two fragments. The extent of separation depends on the amount of laceration of the capsule on each side of the line of fracture (Fig. 551). On each side of the patella the fibrous expansion of the quadriceps tendon, fascia lata, and joint capsule, if intact, will prevent separation of the fragments. If it is ruptured widely it will permit a separation of about 2.5 cm. (i in.). It is rare that the primary injury produces a wider separation, and those cases in which the fragments are wider apart are usually those in which the upper h'agment has been subsequently pulled up by the contraction of the quadriceps. A fracture which when recent may have had only i cm. separation may subsequently show 7.5 to 10 cm. (3 to 4 in.). When the union is fibrous subsequent stretching may occur, also refracture increases the tendency to wide separation. Fracture by direct violeiice is due to the direct impact of a blow or a crushing of the patella between the femur and some foreign body. In this case the capsule on the sides is but little torn and although there may be several fragments they do not become widely separated. character of the injury. When the fracture is from indirect force, means must be employed not only to hold the fragments together, but also to repair the rent in the capsule. Obviously the limb is to be kept in the extended position to relax the quadriceps. The rectus, on account of taking its origin from the pelvis, is also to be relaxed by elevating the limb. A common method of treatment is by open operation. First a flap is raised, exposing the fracture, then the fragments are approximated with wire or other sutures and the rent in the capsule closed with chromic catgut or silk. In fractures by direct violence, when separation is not marked, the lateral fascial expansion remains untorn and no open operation is necessary ; in others, when separation is more marked, and especially if the fracture is compound, a flap may be turned back and the patella surrounded with a strong suture of chromic gut or silk and the fragments thereby drawn together; the suture may also be introduced subcutaneously. By open operation the blood and clots which usually fill the joint can be removed as well as any fibrous tissue from the tendon of the quadriceps \\hich may lie between the fragments. Dislocation of the Patella.^The articular surface of the patella is di\ided by a longitudinal ridge into an outer and inner part, which articulate with the corresponding condyles of the femur. The outer surface for the external condyle is much the larger. The outer condyle is also much higher than the inner and thus tends to prevent luxations. The lateral fibrous expansions on each side of the patella also help to hold it in place. Favoring dislocation is the inclination inward of the knee and the oblique pull of the quadriceps. When a person is standing upright with the feet together the femurs diverge from the knee as they approach the hip, the knees forming an angle of 165 degrees with its apex in. When the quadriceps muscle contracts it tends to straighten this angle and so pull the patella out. If the ligaments are normal and the pull not too violent, luxation does not occur. When, however, from long disuse or disease the ligaments become relaxed, then a sudden and perhaps unusual contraction of the quadriceps will dislocate the patella. This also occurs if the outer condyle is abnormally flat or if the muscular contraction lifts the patella off or above the condyles, as occurs when the tendo patellae is too long. In these, as in almost all other cases, the patella is dislocated outward (Fig. 552). Inward dislocation is almost unknown. Direct injury also produces dislocations, practically always outward. The most common form is for the articular surface of the patella to rest on the outer surface of the external condyle. Other forms, which are more rare, are for the inner edge of the patella to rest against the outer surface of the condyle; for the inner edge to be jammed into the upper portion of the intercondyloid notch with its outer edge sticking up; for the patella to be reversed with its articular surface forward and its anterior surface resting on the condyles. For treating the affection in slight cases an elastic knee-cap may be of ser\-ice, but a cure is probably best achieved by the operation of Goldthwait {Boston Med. and Surg. Joicrji., Feb. 13, 1904). In this the tendo patellae is split longitudinally and its outer half detached from the tibial tubercle, passed under the remaining half, and sewed fast to the periosteum and expansion of the sartorius at the inner side of the anterior surface of the tibia. This shifts the pull of the quadriceps more inward and the shortening of the tendon holds the outer edges of the patella more firmly against the edge of the external condyle. Simple folding of the inner part of the capsule Las been unsuccessful. knee is rarely luxated and then only by •such extreme trauma as sometimes to rupture the popliteal vessels and require amputation. It is frequently compound. The tibia may be luxated anteriorly (the most frequent), posteriorly, to either side, or it may be rotated on the femur. These displacements are usually due to hvperextension and rotation. The laceration of the surrounding tissues is so extensive that replacement is usually easy by direct traction and manipulation. As a result of weakening of the ligaments bv disease the hamstring tendons frequently pull the tibia backward, producing a subluxation often difficult to replace (Fig. 553). Dislocation of the Semilunar Cartilages. — The semilunar cartilages do not become displaced in their entirety, but a portion of one of them is torn partly or completely loose and in moving about gets caught between the bones and produces the characteristic symptoms. The joint becomes useless at once and the patient may caused by either a direct blow on the part or by a twisting of the partly flexed ,. . limb. Use of the limb cannot be re- sumed until the caught cartilage is released. This is most readily achieved by extending the leg and then sharply flexing it. Sometimes the loosened cartilage instead of remaining attached at one end is free in the joint and may make its appearance alongside of the patella. In one of my cases one end of the semilunar cartilage was attached to the crucial hgament while the other was attached to the capsular ligament, thus allowing the part between to stretch across the surface of the condyle and be compressed in walking. These floating cartilages form the "■ gelenkrnaus'' of the Germans. These two conditions were first described by Hey under the name of internal derangements of the knee-joint. Synovial disease may also produce symptoms closely resembling those of detached cartilage. Epiphyseal Separations. — The epiphyseal line marking the lower epiphysis of the femur starts at the adductor tubercle, at the upper edge of the internal condyle, and passes across transversely just above the edge of the articular surface. It joins with the shaft between the twentieth and the tiventy-second year, sometimes as late as Fig. 553. — Subluxation of the knee from tuberculous disease, showing the relation of the bones. (From an original sketch by the author.) These epiphyseal separations are produced either by direct violence, by force applied laterally, or by twisting— a common way is for the leg to be twisted by being caught between the spokes of a revolving wheel. They nevei occur later than the age of twenty years and usually occur several years before that age has been reached. Often the displacement is not serious and is corrected before the patient is seen by the surgeon. Occasionally, especially when the lower epiphysis of the femur is affected, displacement is marked, and the fractured surface of the fragment may lie on the anterior surface of the shaft of the femur. Sometimes the injury is compound and the vessels so injured that amputation is required. In spite of the fact that the greater part of the growth of the lower extremity occurs from the bones adjacent to the knee-joint epiphyseal separations almost never interfere with it. This is so true that epiphysiolysis or the deliberate separation of the lower epiphysis of the femur by bending the knee laterally over the hard edge of a table is the preferred operation with some surgeons for the correction of lateral deformities of the knee, especially knock-knee. The injury is usually treated as a simple fracture and heals without incident. making the skin incision care should be taken to carry it back sufificiently far to allow of division of the lateral ligaments; in so doing, however, one should not divide the long saphenous vein and nerve at the posterior edge of the internal condyle. It is essential to recognize the joint-line; it is just below the lower edge of the patella and thence extends laterally about a finger-breadth above the head of the fibula. It is customary to carry the incision from near the posterior edge of the femur on the inner side to the posterior edge on the outer side at the joint-line, passing over the middle of the tendo patellae so as to allow this latter to be readily sutured later if desired. Care is to be taken to avoid wounding the popliteal artery. This lies close to the posterior part of the capsule; hence the latter is not to be divided transversely but is to be separated by keeping the knife close to the bone. Finally, inasmuch as the bulk of the growth of the lower extremity occurs in the upper end of the tibia and lower end of the femur, it is essential to avoid removing the entire epiphyseal cartilages. For this reason formal resections have been abandoned in young children, and in adolescents as little tissue as possible is removed. The epiphyseal line in the femur runs transversely on a line with the adductor tubercle and passes close to the upper edge of the articular surface. The epiphyseal line in the tibia lies rather close to the articular surface, being 1.5 cm. (f^ in.) below in adults and less in children; it slopes down in front to embrace the tibial tubercle (see Fig. 554). When the disease encroaches on the epiphyseal line, rather than remove it the affected parts are to be curetted away and the remainder left. In those cases where the knee is much contracted, either enough of the bone must be removed to allow of straightening or the hamstring tendons must be cut; if this latter is done the external popliteal nerve which runs on the inner posterior surface of the biceps tendon must not be wounded. Tuberculous Disease of the Knee-joint. — The disease begins usually in the epiphyses adjacent to the joint and involves the joint secondarily. The tibia is more frequently the seat than the femur. The swelling and hypertrophy of the synovial membrane and involvement of the adjacent soft parts obliterate the hollows on each side of the patella and cause a bulging below the patella. The knee looks round and swollen, and the condition was formerly called white swelling from the surface being white in color. If liquid accumulates in the joint it becomes distended and flexed, assuming an angle of 120 degrees. The patella is raised from the condyles; it ' ' floats ' ' and if depressed by the finger can be felt striking on the femur beneath, thus demonstrating the presence of liquid in the joint. The swelling extends above the patella to an extent depending on whether or not the subfemoral bursa is involved and whether or not it communicates with the joint. If pus forms it tends to find an exit beneath the lower edge of the posterior ligament or on either side of the patella at the upper end of the tibia. As the disease progresses the ligaments become weakened. The joint, being already flexed at approximately 120 degrees, is flexed still more by the hamstring muscles, and the head of the tibia in old cases becomes drawn backward in a position of subluxation (see Fig. 553, page 541). The pull of the biceps tendon while the leg is flexed rotates the leg outward and this position may persist: a condition of knock-knee is also sometimes marked. The disease is treated conservatively by apparatus, but in exceptional cases the lesser operation of erasion or the greater of resection (see above) is done. Knock-knee and Bow-legs. — These conditions most frequently result from rachitis or paralysis. Bowing inward of the knee is called knock-knee or genu valgum. Bowing outward is called bow-legs or in some instances, when the deformity is in the joint, as when the condyles are unequal in length, genu varum. Knock-knee {Genu Valgi0}t'). This condition has its point of bending most marked at the knee-joint. When caused by rickets the joint surfaces are often not much altered and the deformity is produced by a bending of the tibia or femur close to the joint; hence when an osteotomy is performed just above the condyles of the femur the joint is again brought level and resumes its functions normally (Fig. 555). When deformities of the foot or the malpositions due to paralyses produce knock-knee, then often a certain amount of flexion and external rotation of the leg coexist with perhaps lengthening of the internal condyle. In these cases osteotomy of the femur must often be supplemented or substituted by suitable apparatus, operations on the foot, etc. point of greatest bending is sometimes low down toward the ankles or close up to the knee-joint, or the whole diaphysis of the bones may be curved. They are often curved anteroposteriorly as well as laterally (Fig. 556). When the point of greatest bending is close to the knee-joint it has been called genu varum, but the condyles remain of equal length and the epiphyseal line still remains parallel with the joint line. As knock-knees and bow-legs so commonly occur in the actively growing period, from the second to the fifth year, apparatus is often of benefit, but frequently forcible straightening by means of an osteoclast or by the hand or epiphysiolysis (see page 542) or osteotomy is resorted to for their correction. Osteotomy. — In osteotomy of the femur the bone is to be divided, as advised by Macewen, a finger-breadth, at least, above the adductor tubercle and 1.25 cm. (^ in.) in front of the adductor magnus tendon. In knock-knee many surgeons prefer dividing the bone from the outside of the limb instead of the inside as advised by Macewen. This incision avoids the epiphyseal line, which is opposite the adductor tubercle, and also the anastomotica magna and superior articular arteries. The popliteal vessels are also to be ax^oided by knowing their position and not directing the osteotome toward them. In performing osteotomy of the bones of the leg the tibia is to be divided by the aid of the chisel, and the fibula is to be broken by manual force. Wedge-shaped resections of bone are commonly not to be advised. They are difficult to do, liable to complications, and, under the most favorable circumstances, are very long in healing and do not give any better results than simple osteotomy or osteoclasis. Ligation of the Popliteal Artery. — In the middle of its course the popliteal artery lies deep between the condyles of the femur and on the posterior capsule and gives off the articular arteries. For these reasons ligation in this part of its course is not performed. To ligate it in the zipper part of its course an incision is to be made along the outer edge of the semimembranosus muscle near the middle of the upper part of the popliteal space. The muscle being drawn inward the internal popliteal nerve is first seen and drawn outward, then the vein beneath is also drawn outward and the artery found beneath and a little to the inner side. Don't mistake the semitendinosus for the semimembranosus. The former is a round tendon, the latter is muscular. Another method consists in making the incision immediately behind the adductor magnus tendon. The semimembranosus and semitendinosus are then to be drawn backward and the artery located by its pulsation and the aneurism needle passed from within out. The nerve and vein, being more to the outer side, are not disturbed (Fig. 557). To ligate the popliteal artery in its loicer third, make an incision in the midline between the heads of the gastrocnemius muscle, avoiding the short saphenous vein and nerve. Open the deep fascia, draw the internal popliteal nerve to the inner side, the popliteal vein to the outer side, and pass the needle from without in. Flexing the knee will relax the gastrocnemius and enable the artery to be more readily exposed. Amputation through the Knee-joint. — Disarticulation at the knee-joint is usually done either with a long anterior and short posterior or two lateral flaps. This amputation differs from others in the fact that a large rounded mass of bone — the condyles — with no muscles is to be covered by the flap. Therefore the flaps must be ample and if they are not a piece of the femur must be resected. The internal condyle is larger and projects more than the external. The cicatrix is drawn posteriorly by the hamstring muscles and the resultant stump is good for pressure bearing. If possible the semilunar cartilages should be left on the femur, the incision for disarticulation being made between them and the tibia. The object of so doing is to prevent the retraction of the soft parts and the resultant protrusion of the bone. The extremities of the incision should be well back, so that the lateral ligaments can be readily divided, and should not extend higher than the edge of the tibia. If infection follows, pus may collect in the suprapatellar (subfemoral) bursa. The leg having to support the weight of the body has its bones strongly made. The tibia bears nearly all the weight because it articulates with the femur above and astragalus below and transmits the pressure directly from one to the other. The fibula is slight compared to the tibia and lies posterior to it and to the outer side. The leg bones receive the insertion of the thigh muscles above and give attachment to the muscles which move the foot. The leg therefore is capable of being influenced by the movements of the foot below and the thigh above. At the upper end of the leg can be felt the two tuberosities of the tibia. The lower edge of the tuberosities is on a line with the upper edge of the tubercle. The head of the fibula is almost level with (a little above) the tubercle of the tibia and is situated far posteriorly. Attached to the head of the fibula above is the biceps tendon accompanied by the external popliteal (fibular) nerve and the long external lateral ligament. The tendo patellae is attached to the tibial tubercle. The tibia is triangular in shape, with a sharp edge — the crest or shin — forward, thus forming two surfaces, an internal and an external. The posterior surface is covered by muscles and is inaccessible. The internal surface is subcutaneous and leads down to the internal malleolus. The external surface has the extensor muscles between it and the fibula. The fibula a short distance below its head becomes covered by the peronei muscles and only becomes subcutaneous in its lower anterior fourth. The upper portion of the leg is largely muscular, but at its lower portion it is mainly tendinous. By placing a finger over the muscles while the foot is moved one is enabled to determine whether or not they are paralyzed (.Fig*. 558). It will thus be seen that the extensor and flexor groups are composed of precisely similar muscles only on opposite sides of the leg. They tend to move the foot and toes forward and backward and balance each other. The abductors form a group around the fibula on the outer side of the leg and they abduct the foot. They tend to pronate it. The most active agents in adduction are the tibialis anterior and tibialis posterior. The muscles of the calf form a separate posterior group designed centre of motion at the ankle and its shortness posteriorly. The extensor group lies between the tibia and fibula anterior to the interosseous membrane. The abductor group forms a mass over the fibula, and the flexor group lies between the tibia and fibula on the posterior surface of the interosseous membrane. The muscles of the calf constitute a superficial layer of muscles which end below in the tendo calcaneus (Achillis). The soleus, with the two heads of the gastrocnemius, is known as the triceps surae muscle. It is absolutely essential to understand the grouping of these muscles of the leg because thereby its construction is rendered evident and their influence on distortions of the foot can be appreciated. FASCIA OF THE LEG. The deep fascia of the leg is attached above to the tubercle of the tibia, the tuberosities of the tibia, and the head of the fibula. It gives off two septa from its under surface, one in front separating the abductor or peroneal group from the extensor o-roup, and another posterior which separates the abductor group from the soleus posteriorly. This latter covers the deep flexors and separates them from the muscles of the calf and is continued across to be attached to the medial (internal) edge of the tibia. The deep fascia of the leg blends with the periosteum over the medial (internal) surface of the tibia and also with that of the lateral (external) surface of the fibula in its lower fourth. At the ankle the deep fascia is continued on through the annular ligaments. oneal. The popliteal artery divides into the anterior and posterior tibial at the lower border of the popliteus muscle just below the lower eds^e of the tibial tubercle. / Two and a half cm. ( i in.), or a little the posterior tibial. The Anterior Tibial Artery. — Ligation.— The line of the anterior tibial artery may be taken as from just internal to the head of the fibula to a point on the front of the ankle midway between the malleoli. The anterior tibial artery pierces the interosseous membrane, but the anterior tibial nerve winds around the head of the fibula and joins the artery 5 to 7 cm. (2 to 3 in. ) or more lower down on its outer side. In the Upper Third. — The artery lies between the tibialis anterior and the extensor longus digitorum muscles. This interspace is better recognized by touch than by sight, though a yellowish line of fat or the presence of some small \'essels may indicate its position. The tendency is to make the incision too close to the tibia. This mistake will be avoided if the line of the artery has been marked and the incision made in it. After separating the muscles, the outer edge of the tibia can be felt and on the membrane close to it is the artery with venae comites to each side and the ner\'e farther out. The needle is passed from without inward, and the veins may In the Middle Third. — The incision having been made in the line of the artery, the septum between the tibialis anterior and e^ctensor longus digitorum is usually visible as a depressed line. Flex the foot to relax the tendons, and on drawing the extensor digitorum outward the upper part of the extensor longus hallucis is seen, it also is drawn outward and the artery is found lying on the membrane with the nerve in front of it. with a thin fascia. The ligature is passed from without inward. Low Down in the Leg. — The incision may be made midway between the mner edge of the tibia and the edge of the tendo calcaneus (Achillis). The artery lies beneath the deep fascia on the flexor longus digitorum muscle with the nerve to the outer side. The muscle has fibres as low down as the malleolus and the artery is to the outer side of its tendon. If the artery is sought behind the ankle then it has the a high division. Peroneal Artery. — The peroneal artery is given off from the posterior tibial 2.5 cm. (i in.) below the lower edge of popliteus muscle. It follows the inner edge of the fibula beneath or in the fibres of origin of the flexor longus hallucis. If it is desired to ligate it, the incision is to be made over the inner edge of the fibula, the edge of the soleus is drawn inward, the fibres of the flexor longus hallucis divided, and the artery found at the junction of the inner edge of the fibula and interosseous membrane. At the lower extremity of the interosseous membrane the artery pierces it to be distributed to the outer anterior portion of the tarsus and ankle. On the dorsum of the foot is a venous arch which unites with the inner dorsal digital vein to form the commencement of the internal or long saphenous vein. The outer extremity unites with the outer dorsal digital vein to form the commencement of the external or short saphenous vein. The internal or long saphenous vein begins just in front of the internal malleolus, ascends on the inner surface of the tibia, passes along the posterior border of the internal condyle and thence up to the saphenous opening. In the leg it communicates with the deep anterior and posterior tibial and external saphenous veins and in the thigh with the femoral. At or near the saphenous opening it receives the external superficial femoral vein from the outer anterior surface of the thigh and the internal superficial femoral vein from the inner posterior portion of the thigh. Not infrequently one of these lateral branches may be almost as large as the internal saphenous itself and may be mistaken for it. From the knee down the internal saphenous vein is accompanied by the internal saphenous nerve. The external or short saphenous vein begins behind the external malleolus, ascends alongside the tendo calcaneus (Achillis), thence over the gastrocnemius to empty into the popliteal vein. Its branches anastomose with those of the internal saphenous on the inner side of the leg and it communicates through the deep fascia with the deep veins. It is accompanied by the external saphenous nerve. Varicose Veins of the Leg. — A varicose condition of the veins of the leg is very common. Often the cause cannot be ascertained, but not infrequently pelvic tumors, and especially pregnancy, produce the condition by obstructing the bloodcurrent. The veins become distended and the valves, of which there are manv, become insufiicient. This destroys the valvular support of the blood column and the veins become tortuous and inflamed, the walls thicken and may become adherent to the skin. The walls in places give way, causing hemorrhages. They may become thin and sacculated and thrombi may form and suppurate. The treatment consists in Hgating and excising as many of the affected veins as possible. The internal saphenous is especially to be excised, beginning a short distance below the saphenous opening and extending for the greater portion of its length CFig. 563 ). The operation of Max Schede, of circular incision around the leg just below the knee, dividing everything down to the deep fascia, is usually effective, but we have seen recurrences even after it, due to regurgitation from the deep veins. Sometimes there are one or two lymphatic nodes at the upper extremitv of the anterior tibial artery but usually the first to be encountered are around the popliteal vessels, — below that point are only lymphatic radicles or vessels. Fractures of the bones of the leg are most often due to direct violence, but sometimes to indirect. The tibia is rarely broken alone, but either it or the fibula may be fractured by a direct blow. On account of the tibia being subcutaneous these fractures are frequently compound. The shafts of the bones, being of compact tissue, are usually broken obliquely. When the fibula is broken above its lower fourth there is usually little displacement because the attached muscles hold it in place. Fractures of the tibia whether accompanied or not by fracture of the fibula most often occur at the junction of the middle and the lower thirds. The line of fracture is downward, forward, and inward. The displacement of the lower fragment is backward, upward and slightly outward. It is produced mainly by the muscles of the calf pulling on the tendo calcaneus (Achillis). The upper fragment is pulled forward by the quadriceps femoris (Fig._564;. The difficulty usually encountered in treatment is a persistent projecting forward of the upper fragment with a drawing up and turning outward of the lower fragment and foot. The displacing action of the tendo calcaneus ( Achillis j is more powerful than that of the quadriceps. On this account the first attempt at correction should be to place the leg in the in some cases to allow of the displacement being remedied. If this fails extension may be tried or tenotomy of the tendo calcaneus should be done and the fragments will at once come into good position. Woolsey has pointed out that the weight of the foot tends to its outward displacement but another reason is that the insertion of the tendo calcaneus is not beneath the middle of the ankle-joint but more towards its outer side, so that when it contracts it carries the foot outward. The flexor and extensor muscles of the leg balance each other, but the peronei muscles on the outer side have no additional corresponding opponents on the inner side; hence another reason for displacement of the foot and lower fragment outward. length to the stump below the knee and allows sufificient space below for the instrument maker to place the mechanism of the artificial leg which operates the foot. The sharp projecting edge of the crest of the tibia tends to produce ulceration of the tissues or skin in front of it, therefore it is to be cut off. obliquely. The fibula, if divided at the same level as the tibia and especially if anteroposterior fiaps are used, tends to project too prominently on the outer side, hence it is preferable to divide it at a higher level than the tibia. Surface Anatomy. — A knowledge of the contour of the ankle aids considerably in determining the character of its diseases and injuries. The malleoli form prominences with distinct hollows above and below them. The sharp anterior edge of the tibia if followed down leads to the tibialis anterior tendon. On the medial (inner) side the malleolus is large and flat. It is subcutaneous and can be readily palpated. At its anterior edge is the commencement of the internal saphenous vein which runs up and slightly back to reach the posterior edge of the tibia 5 to 6 cm. (2 to 2^ in.) above the tip of the malleolus. About 4 cm. ( i^ in. ) below and in front of the internal malleolus is the prominent tubercle of the scaphoid. The external malleolus is small and somewhat pointed, and is placed a fingerbreadth below and behind the level of the internal malleolus. For a distance of about 7.5 cm. (3 in.) above its tip the fibula is subcutaneous and readily palpated. It is here that it is most often fractured. The transverse line of the joint is level with the upper limit of the swell of the internal malleolus — about 2.5 cm. (i in.) above the tip of the external malleolus. The ankle is covered in front and behind by tendons, most of which, especially in thin people, can be felt and seen when they are put on the stretch. Anteriorly the innermost tendon is the tibialis anterior, next the extensor longus hallucis, and then the extensor longus digitorum. Sometimes close to the outer side of the extensor of the little (fifth) toe the contraction of the peroneus tertius tendon can be felt as it goes to be inserted into the fifth metatarsal bone near its base. Running directly downward along the posterior edge of the external malleolus and fibula are the peroneus longus and brevis tendons, the former being the more superficial. About 2.5 cm. (\ in.) below and a little in front of the external malleolus is the peroneal tubercle of the calcaneum ; the peroneus brevis passes in front of it to be inserted into the prominent tuberosity of the fifth metatarsal bone. The long tendon passes behind the tubercle, winds around the cuboid, and crosses the sole to insert into the internal cuneiform and base of the first metatarsal bone. Posteriorly the tendo calcaneus (Achillis) is large and prominent — along the anterior edge of its lateral (external) side run the external (short) saphenous vein and nerve. Running upward from the posterior border of the internal malleolus the tibialis posterior tendon can sometimes be seen and felt. Posterior to it runs the flexor longus digitorum muscle, then the posterior tibial artery, accompanied by venae comites, then the posterior tibial nerve, and lastly the flexor longus hallucis. The artery can be felt pulsating midway between the tendo calcaneus and the internal tuberosity of the calcaneum. The anterior tibial artery can be felt pulsating to the lateral (outer) side of the flexor longus hallucis. grees extension. The tibia and fibula above articulate with the surface of the body of the astragalus below. The articular facet for the fibula is about twice as long from above downward as is that for the internal malleolus. The hollow below the internal malleolus is filled by the internal lateral ligament and the tendon of the tibialis posterior. The inferior tibiofibular joint is sometimes practically lacking, there being almost no continuation of the ankle-joint up between the tibia and fibula. The junction of these two bones is very strong, the ligaments being an anterior, posterior, interosseous, and a transverse inferior tibiofibular ligament which passes across the back of the ankle-joint reinforcing the posterior portion of the capsular ligament. The upper surface of the astragalus is one-fourth wider in front than behind, so that in extension it is not so firmly locked between the malleoli as in flexion (Fig. 568). Its upper surface is slightly concave. Flexion and extension take place on a transverse axis passing through the body of the astragalus at the tip of the external malleolus. This axis is not exactly transverse but is slightly oblique, so that on extension the foot is pointed slightly outward. The ankle has a capsular ligament which is very thin in front and behind the joint. Posteriorly it is reinforced above by the transverse inferior tibiofibular ligament. The flexor longus hallucis also supports it posteriorly. The internal and external lateral ligaments are strong, the internal being the stronger. The internal lateral or ligamentum deltoideum runs from the malleolus above to the scaphoid, astragalus, and calcaneum below. It is crossed on its surface by the tendons of the tibialis posterior and flexor longus digitorum muscles (Fig. 569). The external lateral ligament has three fasciculi: an anterior one to the astragalus; a middle one to the side of the calcaneum, and a posterior one to the posterior part of the astragalus (Fig. 570). In both extreme flexion and extension the edges of the tibia come in contact with the astragalus and hence limit further movement. The ligaments also aid in restricting motion. Fig. 568. — The upper articular surface of the astragalus, showing it to be slightly concave and one fourth wider in front than Vjehind. Distention of the Joint.— Fluid tends to find exit from the joint first anteriorly under the extensor tendons, next it tends to exude posteriorly and makes its appearance as a swelling on each side of the tendo calcaneus fAchillis;. The anklejoint is a comparatively tight one and in acute inflammations holds but httle eflusion. When injected it assumes the position of a right angle and flexion- does not occur as in other joints (Fig. 571). The rounded appearance of the ankle in tuberculous and other affections is not due so much to effusion within the joint as to inflammatory and tuberculous exudate in the tissues around the joint. external lateral ligament case other of the tarsal bones are also frequently involved. In the latter an extraarticular operation on the tibia above the internal malleolus may cure the disease, but the motion in the joint often remains impaired. eased bone away. If it is desired to excise the joint it can be done by Konig's incisions, one along the anterior edge of the internal malleolus and the other along the anterior edge of the external malleolus. Through these incisions all that is necessary can usually be done. Sprain of the Ankle. — In what is usually called a sprain of the ankle the injury is not alvvaj's confined to the ankle-joint and its ligaments. It has been shown that in many cases there is a tearing off of small fragments of bone, hence the name fracture-sprain (Callender). The ankle-joint has an anteroposterior motion, but the lateral motion of the foot takes place mainly in the subastragaloid joint with some additional movement allowed by the other tarsal joints. Inasmuch as sprains are usually the consequence of a lateral displacement, the resultant injury is frequently J in the subastragaloid and sometimes in the is located below and in front of the ankle rather than around the ankle itself. The sprain is more often the result of inversion than of eversion of the foot. In eversion the plantar ligaments are so strong that the foot moves as a whole and the force is transmitted directly to the ankle and leg bones, and most likely results in the production of a Pott's fracture of the fibula with or without a tearing off of the internal malleolus or rupture of the ligamentum deltoideum (internal lateral). Treatment. — The principle of treatment in sprains is to prevent the ruptured ligaments and strained tissues being again irritated and kept from healing by subsequent movements of the injured parts. A small degree of movement is usually painless and unharmful, but a more extensive, and often accidental, movement causes the pain and disability to persist. The failure to apply an efficient dressing which properly limits motion until the primary effect of the injury has passed is the reason of these disabilities becoming chronic. Sometimes fixed dressings like plaster of Paris or silicate of soda are applied for two weeks. Fixation by adhesive plaster has been found very efficient. Gibney demonstrated this. Inasmuch as the injury is usually produced by inversion, the plaster is applied especially to prevent inversion and likewise to give general support. Gibney' s method consisted in applying alternate narrow strips of adhesive plaster, one set beginning on the inner side of the foot and going well up on the outer side of the leg, and the other running parallel with the sole of the foot from the heel to the dorsum. Another method consists in taking a long strip of plaster 7.5 cm. (3 in.) wide, and beginning high up the leg on the inner side, carrying it down under the sole and drawing it firmly up and fastening on the outer side of the leg almost to the knee. This is reinforced by encircling strips around the ankle and instep. The foot may be dislocated from the leg in nine different manners. 1. The foot as a whole may be carried outward. This is almost always associated with fracture of the fibula, and sometimes of the internal malleolus, constituting Pott's fracture (see page 557). 9. The astragalus may be pushed up between the bones of the leg. In Numbers i and 2 inward and outward displacement the foot is not immediately beneath the leg, but is to one side of the leg. The outward luxation when accompanied with laceration of the inferior tibiofibular ligaments or tearing off of a small portion of the tibia and fracture of the internal malleolus and fibula constitutes Dupuytren's or Pott's fracture. In Numbers 3 and 4 the foot remains beneath the leg bones and is not displaced much laterally. Numbers i and 3 are usually grouped together as outward luxations, and 2 and 4 as inward luxations. Numbers 5 and 6 are very rare. The foot is rotated so that one side looks forward and the other backward. Number 7 backward luxation is the most common, with the exception of Number i. When associated with Pott's fracture, backward luxation is produced by hyperextension followed by a thrust and is often compound. The leg is bent backward until the anterior and lateral ligaments rupture, and then the thrust sends the tibia forward on the instep. The articular surface of the astragalus being wider in front opposes the luxation, and fracture of one or both malleoli may result. Numbers 8 and g forward and upward luxations are extremely rare, the former on account of the difficulty in the application of the dislocating force, — the flexion and thrust, — and the latter on account of the extreme strength of the inferior tibiofibular ligaments. Treatment. — In attempting reduction of these luxations the principal thing is to relax the tendo calcaneus (Achillis) by flexing the knee. If this is not sufficient, tenotomy should be practiced. Simple extension with slight rotation and manipulation will then accomplish reposition. Fractures of the ankle are usually the result of a force applied laterally, though sometimes a turning of the foot on the vertical axis of the leg may assist. The force applied causes fracture by inversion or eversion of the foot. Pott's Fracture or Fracture by Eversion. — This is named after Sir Percival Pott, Surgeon to St. Bartholomew's Hospital, London, who described the injury, and was himself a victim of it. The French call it Dupuytren's fracture. It is produced by forcing the foot outward, or by having the foot firmly fixed and then bending the limb outward, thus breaking it at the ankle. The fibula is broken 4 to 7.5 cm. (ij5^ to 3 in. ) above its lower end and the ligamentum deltoideum (internal lateral) is either ruptured or the internal malleolus is torn ofT. Rarely the outer portion of the articular surface of the tibia may be torn off and displaced outward with the lower fibular fragment. It is to be noted that in this fracture the foot, with the small fragments of tibia and fibula, is practically loosened from the bones of the leg, and the muscles of the calf being unopposed pull the foot backward and upward. Therefore the displacement of the foot is not only outward, but also backward and upward (Fig. 573.) Fracture iDy Inversion. — This is practically the opposite of the former and is not so frequent. The fibula is fractured by the traction of the external lateral ligaments which remain intact; it may break either above or below the strong inferior tibiofibular ligaments. The internal malleolus may also be torn ofl. The displacement is toward the inner side and upward and backward (Fig. 574). fibula by inversion of the foot. tibia. The deep fascia of the leg is attached to the fibula and its sharp broken ends may get so fastened or caught in this fascia as to require an open incision before they can be freed sufficiently to allow of their proper replacement. Another difificulty is in the reduction of both the lateral and posterior displacement. Here it is necessary first to relax the muscles of the calf by flexing the leg on the thigh, then by pulling and direct pressure the foot can often be replaced, "if this fails tenotomy of the tendo calcaneus (Achillis) is to be done, which relaxes the parts still more by releasing the pull of the soleus, the gastrocnemius and plantaris being already relaxed by flexion of the knee. This is sometimes necessary to prevent the persistent of retention is sufficient. In other cases it is better to place the leg in the Pott's position, viz., lying on its outer side with the knee flexed. For similar injuries, Dupuytren advised placing the leg on a straight internal lateral splint on a pad which extended from near the knee down to the seat of fracture. The leg was fastened near the knee to the upper part of the splint, and the foot which projected beyond the pad was drawn by bandages toward the lower part of the splint. nearer the posterior than the anterior edge of the bone) to the opposite point on the inner side, which will be rather below the tip of the internal malleolus." The extremities of this incision are connected by another directly across the front of the anklejoint. The anterior capsule is then divided and the lateral ligaments divided from within outward. The foot being bent down, the tendo calcaneus is cut close to the bone and the calcaneum dissected out. The malleoli are then to be cleared and sawn of! with a thin slip of the articular surface of the tibia (Fig. 575). be divided and the integrity of the flap threatened. In clearing the calcaneum it is rather an advantage, especially in young people, to take off a thin slice of bone with the tendo calcaneus. In removing the slice from the tibia as little as possible (in growing patients) should be removed, to avoid injuring the epiphyseal cartilage. In dissecting back the flap of the heel, the point of the knife is to be kept close to the bone to avoid cutting the vessels in the flap itself. Pirogoff's Amputation. The anterior incision is made across the front of the joint and the foot disarticulated by dividing the capsular and lateral ligaments. The foot is then bent down and the calcaneum sawn through the line of the sole incision. A slice is to be removed from the tibia and fibula and the sawn surface of the calcaneum brought up and sutured with chromic catgut (or other) sutures to the sawn surface of the tibia (Fig. 576). In bringing up the calcaneum to the tibia it may be found difficult to approximate them without undue tension on the tendo Achillis. To provide against this common diiificulty it is customary to place the saw on the upper surface of the calcaneum well behind (a finger-breadth) the joint. Also to dissect back the heel-flap .50 to I cm. (^ to y^ in.) so that more of the calcaneum can be removed. A larger slice is also taken from the tibia than in Syme's amputation. If the tension remains too great on the tendo calcaneus it is to be divided. The foot is intended for support and locomotion. The locomotion takes place in the upright position and, in moving, the weight is shifted from one foot to the other. . Hence we see that if the foot is to fulfil its function of support it must have strength, because on it rests the weight of almost the whole of the body. If a person is at rest in a standing position the foot is subject to a continuous static pressure which, if any part of the foot is abnormal, whether from congenital or acquired qualities, will eventually result in distortion and impairment of function. If a person is moving about, the foot is subjected to a pressure which is dynamic (movable) in character, and is much greater in amount than is the static pressure of the body at rest. The movements of the foot in locomotion are not always slow, sometimes they are exceedingly rapid. A person treads on an uneven or unstable surface and the foot must adapt itself instantly or injuries will result; failure to do so results in sprains, fractures, and luxations. In running rapidly the changes in position of the component parts of the foot are instantaneous, otherwise rapid running is impossible. In jumping especially the dynamic pressure plus the inertia causes an enormous strain on the foot. The mobility demanded of the foot is not so great, however, as that of the hand because the movements are neither so intricate nor so numerous. A consideration of these facts enables one to understand: first, the method of construction of the foot; second, its injuries, diseases and deformities; third, the means necessary to employ in preventing and curing them and m obviating to as great extent as possible their consequences. The Construction of the Foot. — The foot is constructed with a view of possessing strength and mobility. Strength is obtained by the bones being short and solid, well compacted together in the form of a double arch, joined by strong ligaments, and supported by powerful muscles. The double arch forms the together there is formed a ' ' dome-shaped space ' ' arching anteroposteriorly from the internal tuberosity of the calcaneum to the head of the first metatarsal bone, and laterally from the inner to the outer edge (Fig. 577). Mobility is obtained by the bones and joints being numerous and the muscles highly specialized. Diseases and Injuries of the Foot. — Disease weakens the foot — sometimes, as in adolescents, the foot is weakened without any apparent disease. In other cases the bones and ligaments become affected, as in rickets, rheumatism, gout, and tuberculous disease. In still others the muscles become affected, either contracted, as in spastic diseases, or relaxed, as in infantile paralysis. When the bones and ligaments are involved they fail to bear the body weight, the arch is crushed and flat-foot and eversion results. Hence valgus is almost always a disease of weakness. If muscles become affected by spasm or paralysis all kinds of deformities are produced. There are many muscles controlling the foot and frequendy only one or a few are paralyzed ;. this leaves the balancing muscles unopposed and they drag the part toward the healthy side. Anything that disturbs the equilibrium or balance of the various muscles results in distortions and deformities. Injuries impair the efficacy of the mechanism of the foot. A crush of the head of the first metacarpal bone destroys the anterior support of the arch and the resultant weakness is marked. The Treatment of Affections of the Feet. — The foot is exceptionally 'accessible both for diagnosis and treatment. The bones and joints are accessible often to both sight and touch, and one should know where to look and feel for them. Exploratory operations in this portion of the body are out of place. An accurate knowledge'of the structures of the foot is absolutely essential to intelligent treatment. The deformities are dependent on muscular action, and one should know the position of the tendons and the influence of the muscles. In amputating, a knowledge of the joints is essential. The problems presented are largely of a mechanical nature, to be solved by a thorough knowledge of the structures and the application of mechanical principles to living tissues. pathology. The bones of the foot are numerous, so as to give it mobility and to lessen shocks. If the bones become ankylosed the footing becomes insecure, balancing is difficult, the gait is altered, and great care is necessary in locomotion to avoid straining and injury. The foot is triangular in shape, being broad across the toes and narrow at the heel. Its bones compose the tarsus, metatarsus, and phalanges. Of these the first two are essential, but the third is less so. Phalanges are more or less for prehensile uses, and as man, as we see him, encases his foot in shoes he makes but little use of the toes, hence they are the least im- . portant part of the foot. They are used somewhat in walking, and to a greater degree in balancing, climbing, running, etc. They add to the efficiency of the foot, but their loss does not impair it to a great extent. Intricate and delicate movements may be interfered with, but the more deliberate firmer movements, as in walking, may remain almost normal. The big toe has only two phalanges and this increases its strength at the cost of mobility. The remaining portion of the foot is composed of the metatarsus and tarsus — five bones of the former and seven of the latter. weight of the body is transmitted through the interyial set, which is in relation with the tibia. It consists of the astragalus {talus), scaphoid {navicular) , the three cuneiform^ and the inner three metatarsal bones with their corresponding phalanges (Fig. 578). The external set is in relation with the fibula, and is composed of the os calcis, cuboid, and outer two metatarsals with their corresponding phalanges. the external portion is balance. They suggest that from a functional standpoint the foot may be divided into an internal portion composed of all the tarsal bones and the first metatarsal bone with its phalanges, and an external portion consisting of the outer four metatarsal bones and phalanges. They show that in dis- Astragalus of division passes between the first and second metatarsal bones; the first metatarsal is usually displaced inwardly, while the second, third, fourth, and fifth metatarsal bones are practically always displaced outwardly, there being a considerable separation between the metatarsal bone of the big toe and the second metatarsal bone adjacent. When there is congenital absence of the tibia the foot bones related to it are also lacking, and when the fibula is lacking there are no bones of the external set. In man both sets contribute to support, but the tibial or inner set is the more important, the fibular or outer astragalus, scaphoid, three cuneiform and inner three metatarsal bones. The highest point of this arch is the midtarsal joint between the astragalus and scaphoid (Fig. 579). The oider arch is composed of the os calcis, cuboid, and outer two metatarsal bones. It is much lower than the inner arch. The highest point is between the cuboid and os calcis, and when weight is borne on the foot this outer arch becomes obliterated and comes in contact with the ground. The transverse arch has its outer end supported by the outer edge of the foot, which through the medium of the soft parts is in contact with the ground. Its inner end is supported by the inner edge of the foot which is some distance above the ground. Thus it is seen that the weight of the body is transmitted from the body of the astragalus in three directions, viz. , backward to the tuberosities of the os calcis, forward to the heads of the metatarsal bones, and laterally toward the base of the fifth metatarsal bone. The posterior pillar of the anteroposterior arch is short, thick, and composed of only two bones, the astragalus and os calcis. It is stiff and strong, but having only two parts is comparatively immovable. The anterior pillar of the arch is longer and has more bones and, while it is not so strong against static pressure as the posterior pillar, is, on. account of its elasticity and mobility, far more eflective against dynamic (active) pressure. Thus it is that when a person jumps from a height and ahghts on the sole of the foot the astragalus or os calcis of the posterior pillar is fractured while the bones of the anterior pillar escape. The internal part of the foot is more liable to give way than the external part because the external part is practically in contact with the ground while the internal part has as its support ligaments and muscles, and when these latter give way it is the inner side of the foot which sinks. This is still more favored by the position of the tuberosities of the os calcis with reference to the ankle-joint; they are not directly beneath it, but somewhat to its outer side. THE JOINTS AND LIGAMENTS OF THE FOOT. The amount of movement that takes place between the bones of the foot is not as great as would be expected from their number. It is only in the subastragaloid joint that any considerable motion takes place, while a less amount occurs at the midtarsal joint. The contiguous tarsal bones are joined by numerous band-like, capsular, and interosseous ligaments which allow a limited amount of movement between them. In the aggregate these movements are considerable and make the foot as a whole quite flexible. The Subastragaloid Joint (Articulatio talo-calcaneo-navicularis). — This is a horizontal joint formed by the astragalus abo\e and the os calcis and navicular (scaphoid) below and in front. It runs obliquely forward and inward. The astragalus is not wedged in between the os calcis and scaphoid like the keystone of an arch, but the foot moves freelv beneath it. It has an inward motion of adduction around an anteroposterior or longitudinal axis with internal rotation around a vertical axis, and an outward motion of abduction with external rotation. The abduction and adduction movements cannot occur independently of rotation, they are combined. The astragalus is joined to the os calcis below and scaphoid below and in front by short fibrous bands which help to form the capsule. The under surface of the subastragaloid joint is formed first by the surface of the scaphoid, next by the inferior calcaneoscaphoid ligament, then by the upper surface of the sustentaculum tali, then by the interosseous ligament, and finally by the posterior surface of the os calcis. The inferior calcaneoscaphoid ligament is the most important one in maintaining the integrity of by the superincumbent body weight, the joint is strengthened bv three ligaments, viz. : 1. The interosseous astragalo-calcaneal iigauient, which runs obliquely forward and outward between the os calcis and astragalus and divides the subastragaloid joint into an anterior and posterior portion. It is very strong (Fig. 582). its deep part from the tibia above to the side of the astragalus below and likewise to the scaphoid in front, and by its superficial part to the sustentaculum tali (Fig. 5S3 ). 3. The external lateral ligament of the ankle, the anterior and posterior fasciculi of which are both attached to the astragalus and the middle fasciculus of which goes to the os calcis below (Fig. 584). When the weight of the body is transmitted to the foot it tends to flatten the anteroposterior arch. If the arch descends it can only do so either by pushing the astragalus up — luxating it — or by the ligaments of the arch stretching or rupturing and allowing the two pillars of the arch to separate. In disease the ligaments elongate and by violence they may be ruptured, the arch in each case falls. If the ligaments supporting the astragalus remain intact then excessive lateral movement ruptures those on the side and a sprain of the subastragaloid joint is produced which is often called a sprain of the ankle. The Midtarsal Joint (Chopart's Joint). — This is composed anteriorly of the scaphoid and cuboid bones and posteriorly by the astragalus and os calcis. The movements are not extensive and consist of flexion with inward rotation of the sole, and extension with outward rotation of the sole. The joint is separated into an inner and outer portion by an interosseous ligament where the cuboid, astragalus, and os calcis meet. various bones composing it are bound together not only by the short ligaments passing between contiguous bones, but the arch is strengthened by three special ligamentous structures. They are the inferior calcaneoscaphoid ligament, the plantar ligaments, long and short, and the plantar fascia. The inferior calcaneoscaphoid ligament {^ligamentuin calcajieonariculare plantare^ runs from the lower inner portion of the scaphoid, posterior to its tubercle, to the sustentaculum tali. It is an extremely strong fibrocartilaginous band. Anteriorly and above it blends with the internal lateral ligament (deltoid) of the ankle. Together with the posterior surface of the scaphoid it forms a socket for the head of the astragalus. This ligament fills the long gap left in the inner arch of the foot between the scaphoid and os calcis. Running vmder and supporting it is the tendon of the tibialis posterior (Fig. 585). The long plantar or long calcaneocuboid ligame?it {ligamentiun plantare longum) is attached to the under surface of the os calcis in front of its tubercles and thence runs to the peroneal ridge on the cuboid bone and continues onward to for the peroneus longus tendon, which runs beneath it. The shor't plantar or short calca7ieocuboid ligament {ligamentnui calcaneocuboidcnm plantare^ lies beneath the long ligament and is separated from it by a small amount of fatty tissue. It runs obliquely forward and inward from the under surface of the calcaneum to the posterior portion of the cuboid. The Plantar Fascia (aponeurosis plantaris). — The middle portion of the plantar fascia runs anteriorly from the inner tubercle of the os calcis to be attached to the sides of the metatarsophalangeal articulations and bases of the proximal phalanges. It is a thick, strong triangular band. The outer portion is a strong band running from the external tubercle to the tuberosity of the fifth metatarsal bone. The inner portion is thin and weak (Fig. 586). , . , ,. , r These three ligamentous structures, the calcaneoscaphoid ligament, plantar ligaments, and plantar fascia are all large, strong, fibrous structures. They jom the anterior and posterior pillars of the arches like the string of a bow and prevent them from separating. When a person is standing at rest these are the mam ligaments which bear the weight of the body. The static weight is borne by the ligaments but the dynamic weight (movements) is borne by the muscles. THE xMUSCLES OF THE FOOT. The foot is acted upon by long muscles which come down from the leg and short muscles which arise in the foot itself. Of these the long muscles are the more important because they influence the position of the foot itself, whereas the short muscles act on the toes ; as stated the movements of the toes are of secondary importance (page 562). The functions of the muscles are active or dynamic in character. They bear the weight of the body when in motion and direct the movements of the foot in locomotion. Their function and structure are to be studied together, as one explains the other, and a knowledge of them explains many deformities and indicates their treatment. The loyig muscles have three distinct actions on the foot: (i) they support the arch of the foot; (2) they fle.x; and extend the foot; (3) they abduct and adduct the foot — this latter being associated with a certain amount of rotation. The action of the individual muscles is not a simple one. They act on two joints, the ankle and subastragaloid. If the former is stationary they abduct and adduct, if the latter is stationary they flex and extend, but if both move then a combined action of the muscles is necessary. The Action of the Muscles in Supporting the Tarsal Arch. Tibialis Anterior. — The tendon of the anterior tibial descends along the anterior edge of the internal malleolus and inserts into the lower inner surface of the internal cuneiform bone and base of the first metatarsal bone. Tibialis Posterior. — Its tendon passes down close behind the posterior edge of the internal malleolus, crosses the internal lateral • ligament of the ankle, passes under the inferior calcaneonavicular (scaphoid ) ligament and in front of the sustentaculum tali to insert into the tubercle of the navicular (scaphoid). From the tubercle its tendon sends slips to all the tarsal bones except the talus (astragalus) and to the bases of the second, third, fourth, and sometimes fifth metatarsal bones. Flexor Longus Digitorum. — Its tendon passes behind the internal malleolus immediately posterior to the tibialis posterior and then curves around the sustentaculum tali to enter the foot, passing forward to insert into the base of the terminal phalanges of the outer four toes. Flexor Longus Hallucis. — This tendon descends across the middle of the posterior part of the ankle-joint and curves forward under the sustentaculum tali. It is the most posterior of the structures running behind the internal malleolus. It lies deeper than the tendon of the flexor longus digitorum, and as it crosses it gives to it a small slip. It then inserts into the base of the terminal phalanx of the big toe. Peroneus Longus. — This tendon overlies the tendon of the peroneus brevis as it passes down immediately behind the external malleolus. It then winds around the outer surface of the os calcis behind the peroneal tubercle to pass obliquely inward and forward across the sole of the foot, in a canal formed by the long plantar ligament and a groove in the cuboid bone, to insert into the base of the first metatarsal bone and internal cuneiform. Peroneus Brevis. — This tendon passes down behind the external malleolus beneath and a little anterior to the tendon of the peroneus longus. It passes in front of the peroneal tubercle and then goes forward to insert into the tuberosity of the fifth metatarsal bone. inserts into the upper surface of the fifth metatarsal bone near its base. The other muscles of the leg do not support the tarsal arch. In consideringthe insertions of these tendons it will be seen that the tibialis anterior, peroneus tertius, and peroneus brevis are practically inserted into the convexity of the tarsal arch and tend to support it by pulling it upward. The flexor longus hallucis and flexor longus digitorum run longitudmally beneath the arch and so directly support it. The tibialis posterior and peroneus longus, one from the inner and the other from the outer side, meet and cross on the sole of the foot, thus forming a double sling immediately beneath the arch on which it rests when those muscles contract. If these muscles, on which the arch directly relies for its support when subjected to the strain of locomotion, are unable to meet the demands made upon them then the strain falls on the ligaments, and as these are intended for static and not dynamic purposes they weaken and give way and the arch descends. To cure such a condition over use must be avoided and the strength of the muscles is to be restored by exercise, massage, electricity, etc. The peroneus group of muscles exert so little influence on flexion and extension that in many cases they may be ignored. The peroneus tertius flexes the ankle, while the longus and brevis extend it. The common movements of the foot when great strength is not required are performed by the flexor and extensor groups of muscles ; the muscles of the calf are not so much for adding to the kind of movements as to the amount. The powerful calf muscles have the function of aiding the body in maintaining the iipright posture and especially in lifting and propelling it forward in locomotion. When most of the flexors and extensors are paralyzed the foot hangs loose from the leg, the so-called flail-foot. Weakness of the flexor group (tibialis posterior, flexor longus digitorum, and flexor longus hallucis) tends to favor a descent of the arch with consequent pronation or eversion. Weakness of the extensors causes toe-drop and inversion or supination. Paral3'sis of the calf muscles deprives the posterior pillar cf the arch of its support and the action of the flexors and extensors elevates the arch while the heel descends, so that a condition of hollow foot is produced. Paralysis of the calf muscles is not rare, while that of the deep flexors is less common. The question of paralysis must be studied with reference to each individual case, because the affected muscles are not always completely paralyzed, neither are all the muscles of a group. movements of the foot are comparatively weak when compared with those of flexion and extension. They are intended largely to maintain the balance or equilibrium and to adapt the position of the foot to uneven surfaces, etc. Three muscles act very distinctly as abductors ; they are the peroneus longus, brevis, and tertius. Two act as distinct adductors, viz. : the tibialis anterior and the tibialis posterior. The muscles of the calf act more as abductors than adductors, because the insertion of the tendo calcaneus (Achillis) is not directly behind the ankle-joint but more to its outer side. When the foot is deformed in the position of inversion, as in club-foot, the tibialis anterior and posterior are usually contracted, but when in the position of eversion, as in flat-foot, then spasm of the peronei or calf muscles is frequent. Plantar flexion of the foot is a far more powerful movement than extension — flexion is associated with adduction or inversion and extension with abduction or eversion ; hence it is that inversion is the position of strength and eversion of weakness. Feats of strength and agility cannot be performed by those who have markedly everted feet. For the clinician and operator an exact knowledge of surface anatomy is absolutely essential. It can readily be acquired because the various bony points and tendons are usually evident both to touch and sight. Bony Landmarks. — There are five prominent bony points : they are the internal and external malleoli, the tubercles of the OS calcis and navicular {scaphoid) and the tuberosity of the fifth metatarsal bone. The interyial malleolus is large and flat and has a somewhat rounded lower edge. It is above and anterior to the external malleolus. Immediately in front of its anterior edge runs the commencement of the long saphenous vein. Around its lower posterior border runs the tendon of the tibialis posterior muscle on its way to the tubercle of the scaphoid. The external malleolus is more prominent than the internal, smaller, and more pointed. The fibula above for its lower fourth is subcutaneous. The tip of the external m_alleolus is 2 cm. (^ in.) below and behind the internal. Around its posterior and lower edge run the peroneus longus and brevis tendons. The hibercles of the os calcis can be felt posteriorly and at the sides. The external surface can be followed forward, but the internal is buried beneath the soft tissues. Of the two tubercles on its under surface the internal can be felt by firm pressure. to the posterior edge of the external malleolus. The peroneal spine (tubercle) can be felt indistinctly as a small bony prominence 2.5 cm. (i in.) below and a little in front of the external malleolus. In front of it runs the peroneus brevis and behind it the peroneus longus. The tibialis posterior, on strongly abducting the foot, can often be seen and felt along the posterior border of the internal malleolus and between the latter and the tubercle of the scaphoid, into which it inserts. The tibialis anterior is the tendon nearest the anterior edge of the internal malleolus. It runs down to the internal cuneiform bone about 2.5 cm. (i in.) in front of the tubercle of the scaphoid. can often be made prominent by flexing the big toe. The extensor longns digitoriun tendons at the ankle lie close together just outside of the extensor longns hallucis. The peroneiis tertins runs from them to the dorsum of the fifth metatarsal bone a little in front of its base. T\\e peroneal tendons can usually be made visible by sharply adducting the foot. The brevis is then seen running back to the peroneal spine 2.5 cm. (i in. ) below and a little in front of the external malleolus and from this point up to behind the malleolus; in thin people both the brevis and longus can be seen and followed up the lower part of the fibula. nal malleolus. The niidtarsal (Chopart's) joint is best found on the inner side of the foot; here it passes immediately behind the tubercle of the scaphoid. On the outer side it is approximately at the middle of a line joining the external malleolus and tuberosity of the fifth metatarsal bone. At this point there is frequently a bony prominence formed by the anterior edge of the os calcis. it and the cuboid. Its inner extremity can be found either by following up the first metatarsal bone from its head for about 5 cm. (2 in.) when a ridge of bone will be felt on its base, the joint being immediately behind it; or by identifying the tubercle of the scaphoid and allowing 2.5 cm. (i in.) from its anterior edge for the internal cuneiform bone. Its exact location is to be recognized by pressing with the edge of the thumb at the suspected spot and moving the metatarsal bone with the opposite hand. The dorsalis pedis artery runs from the middle of the front of the ankle to the base of the first metatarsal interspace. The extensor longus hallucis tendon is on the medial side and the extensor longus digitorum on the lateral. An incision made midway between these tendons exposes the muscular fibres of the extensor brevis digitorum; this is pulled to the outer side and the artery will be found lying on the bone beneath. The extensor brevis digitorum crosses it near its termination. its pulsation in order to determine whether the artery above is intact. The Plantar Arteries. — The tibialis posterior divides into the internal and external plantar arteries at a point midway on a line joining the internal malleolus and internal tubercle of the os calcis. From this point the internal plantar artery runs forward along the medial side of the flexor longus hallucis in the groove between the abductor hallucis and flexor brevis digitorum. It is much the smaller of the two plantar arteries (Fig. 591). The external plantar artery runs from the same point as the internal to the inner side of the base of the fifth metatarsal bone. To this point it lies beneath the flexor brevis digitorum and above the accessorius. It then dips deeper, lying on the interossei, and curves inward to end in the communicating artery which pierces the base of the first metatarsal space to anastomose with the dorsalis pedis. minimi digiti. Formal ligation of the plantar arteries is not often required. If wounded the bleeding can be stopped by packing the wound, applying pressure, and elevating the foot as high as possible. Care is to be exercised in making incisions in the sole of the foot in the grooves to the inner and outer side of the flexor brevis digitorum for iear of wounding the plantar arteries. The external plantar is, however, not liable to be wounded if the incision is made back toward the tubercle of the os calcis. The plantar arteries usually escape division in operating subcutaneously on the plantar fascia because the plantar fascia is above the flexor brevis while the arteries are below. It is so difficult to ligate bleeding arteries in the foot that it is usually better to pack the wound with an antiseptic gauze and elevate the limb. The foot may be amputated through the midtarsal or tarsometatarsal joints. Ordinarily they give unsatisfactory stumps owing to the heel being pulled up by the tendo calcaneus (Achillis), and the shape of the inner part of the tarsal arch. This causes the patient to walk on the end of the stump, which soon becomes painful. To perform these operations skilfully it is essential that one be familiar with the lines of the joints. Plantar flaps are used because the skin of the sole is tougher than that of the dorsum and the cicatrix is out of the line of pressure. of the foot. inside and the ridge on the anterior end of the os calcis, midway between the external malleolus and the fifth metatarsal bone, on the outer side. A short dorsal and a long plantar flap are cut. The plantar flap is longer on its inner side to allow for the greater thickness of the foot on that side. It is easier to begin the disarticulation on the inside, going in just behind the tubercle of the scaphoid (navicular). This part of the joint is convex forward. On reaching the outer edge of the astragalus (talus) care should be taken not to slip posteriorly between the astragalus and os calcis, but to continue laterally. The extensor tendons are to be sutured to the end of the stump and frequently the tendo calcaneus (Achillis) is cut in an attempt to prevent subsequent elevation of the heel. (Fig. 592). Tarsometatarsal (Lisfranc's) Amputation. — The guide to this joint is the tuberosity of the fifth metatarsal bone on the outer side and the ridge on the base of the first metatarsal on the inner side. This latter is about 4 cm. (i 3^ in. ) in front of the highest point of the tubercle of the scaphoid. The joint is best entered from the outer side. The knife is to be passed first forward and then carried inward. Trouble is usually experienced when the base of the second metatarsal is to be disarticulated. It lies behind the others and some surgeons advise skipping it and opening the first metatarsal joint and then completing the disarticulation by opening the second last. The sawing off of the projecting internal cuneiform bone as proposed by Hey is objected to on account of weakening the attachment of the tibialis anterior tendon. The same precaution is to be taken of making the plantar flap longer on its inner side, as was advised in Chopart's amputation, on account of the greater depth of the foot on this side. The line of the joint is best understood by reference to the position of the bones (Fig. 578). Tenotomy of the tendo calcaneus (Achillis) is not so often resorted to in this amputation as in that through the midtarsal joint (Fig. 593). wounds, or by the extension of infection from wounds of the toes, etc. The plantar fascia lies on the flexor brevis digitorum while the long flexor tendons lie beneath it. A punctured wound may perforate the plantar fascia and penetrate the flexor brevis which arises from its under surface, yet if this muscle is not entirely traversed by the wound the tendons of the long flexors beneath escape infection and the pus accumulates beneath the plantar fascia. In the superficial form of plantar abscess the pus tends to point in four directions: (i) it may come directly up through gaps between the fibres of the plantar fascia and make an hour-glass abscess, a small amount of pus being above the plantar fascia, between it and the skin, while a larger collection is beneath the fascia in the substance of the muscle; (2) it may burrow its way forward showing between the tendons in the direction of the webs of the toes; (3) it may appear in the groove on the outer side of the foot between the flexor brevis and abductor minimi digiti; (4) it may appear on the inner side of the foot between the abductor hallucis and flexor brevis (Fig. 594). Deep Plantar Abscess. — In deep infection the pus accumulates around the deep flexor tendons and beneath the flexor brevis muscle. Its greatest tendency is to extend up the leg by following the flexor tendons behind the internal malleolus. It may also show itself in the grooves on either side of the flexor brevis, or between the tendons at the webs of the toes. Incision of Plantar Abscess. — The safest way to open these abscesses is by the method of Hilton, The skin is first incised and the abscess opened by inserting a pointed haemostatic forceps and opening its blades, or using some similar blunt instrument. This is done to avoid wounding the arteries. If necessary the whole through from one side to the other. Incisions should not be made over bony points where they would be subjected to pressure. Hence the heads of the metatarsal bones and the prominent outer edge of the foot are avoided. Incisions in the hollow of the foot and between the forward ends of the metatarsal bones are to be preferred. In opening a subcutaneous collection one should not be satisfied with simply incising the skin, but the fascia should be widely split to guard against a larger collection of pus beneath. Collections which present to the outer side of the flexor brevis are to be opened a little distance behind the base of the fifth metatarsal bone because the external plantar artery becomes somewhat superficial at its inner side. The common deformities of the foot are those in which the parts affected are deformed or turned to an abnormal degree in the direction of their normal movements. Thus in talipes varus the foot is turned inward, hyperadducted; ialipas valgus and flat-foot, turned out, hyperabducted ; talipes eqidnus or hyperextended, talipes calcaneus or hyperflexed, and talipes car us or increase of the arch of the foot. These deformities may be either congenital or acquired, and it is not always easy to separate the two. A deformity may be thought by the parents to have existed from birth, when it may have been caused by an infantile paralysis occurring before the period of walking. are those of paralysis or weakness and contraction or strength. They are usually associated but sometimes separate. There can be a paralysis without contraction, but inasmuch as the muscular system is built on the principle of balance it is obvious that if one muscle or set of muscles is paralyzed it is only a question of time until the opposing muscles become contracted. In a similar manner if contraction exists as the most prominent element and perhaps the primary one, it will usually be found that the opposing muscles and ligaments are stretched and weakened. These conditions furnish the indications for treatment. Where weakness is the predominant feature then Fir.. 595.— Talipes equinovarus. support is to be givcn and Contraction of the relaxed tissue favored. Where strength and contraction is predominant then operations and forcible measures are necessary to overcome them. Also, when in a contracted case the contracted tissues have been overcome, there still remains the weakness of the opposing tissues to be remedied. It may be possible to bring the foot to a perfectly normal position, but until the previously weaken^ and overstretched tissues have regained their tone normal function will not be possible. While the deformities may be simple they are usually compound ; thus an equinus may be associated with a varus or valgus, and is then called an equinovarus or equinovalgus. Cavus or hollow-foot and calcaneous or lowering of the heel are often associated, so that it is difficult to draw a line separating them. Talipes Varus. — Talipes varus in its most common form is congenital and i? often associated with equinus or a drawing up of the heel. The prevailing deformity is one of adduction, with a certain amount of inward rotation (Fig, 595). The muscles favoring it are the tibialis anterior and tibialis posterior ; therefore the tendons of these muscles are sometimes cut to prevent their drawing the foot upward and inward. Division of the plantar fascia is also often necessary. The main principles of treatment are to stretch the contracted tissues forcibly, either by manual or instrumental force, and then maintain the foot in its corrected position, often at first by plaster of Paris and later by apparatus, until the weakened opposing muscles have resumed their functions. This often takes so long that transplanting of tendons has been resorted to; thus the tendon of the tibialis anterior has been detached from its insertion on the inner side of the foot and transplanted to the outer side, so that the contracting force on the inner side of the foot is weakened, while the correcting force of the abducting muscles has been increased. stretching of it allows the heel to descend. Talipes Valgus. — In talipes valgus the foot is abducted or everted. It is sometimes associated with equinus and sometimes with calcaneus. It is more usually an acquired than a congenital deformity. It is a deformity that has weakness as its primary cause and most marked characteristic. This weakness is either a more or less general one affecting the ligaments and muscles, as shown by its occurring in adolescents, or else primarily a muscular one caused by spinal infantile paralysis (anterior poliomyelitis) (Fig. 596). by an eversion of the foot called the pronated foot which is followed by a descent of the tarsal arch or flat-foot and later by a more complete eversion or pes valgus. They are the three stages of the same process. When a young person with apparently normal feet is subjected to excessive strain, as by long standing, etc., the muscles and ligaments are unable to bear the burden. The muscles give way first and the foot everts, mainly at the subastragaloid joint, thus is produced the pronated foot. The patient, unable to support the body weight sufficiently on the weakened muscles, rela.xes them and allows the body weight to be borne on the ligaments. This excess of weight on the ligaments supporting the arch causes them to give way and the arch descends and flat-foot results. The process often stops here in the adolescent form or even if rheumatism is the weakening element (Fig. 597). When paralysis — usually of the extensors and tibialis posterior — is the cause, then the ligaments not being so much affected may maintain the arch intact, but the whole foot is drawn outward by the peroneal and flexor muscles, aided also by the centre of gravity being shifted inward. The deformity is increased by walking and a true valgus results. In the pronated foot and flat-foot of adolescents pain is often marked so that the relaxation of the inverting muscles is often accompanied by spasm of the everting muscles and the peronei muscles are frequently found markedly contracted. In paralytic valgus the eversion of the foot relaxes the peronei and they gradually shorten. It should be noted that the contraction of the peroneal muscles in one case is active, in the other passive. Treatment. — In painful pronated and flat feet the contracted muscles can be relaxed by perfect rest in bed. Next the arch can be supported by pads or plates beneath the instep and the weakened muscles strengthened by massage, electricity, or appropriate exercises while the exciting cause of overwork is removed. In paralytic valgus, the foot may be brought straight by forcible stretching and held there by appropriate apparatus; or an artificial ankylosis (arthrodesis) of the subastragaloid tendons, on the outer side of the foot, may be transplanted to the inner. Talipes Equinus. — This sometimes exists as a pure form but it often accompanies varus and sometimes valgus. It is caused by a paralysis of the extensor muscles. The tendo calcaneus is contracted and the patient walks on the toes. By div'ision or lengthening of the tendo calcaneus and forcible flexion of the foot the heel may be brought down but the foot will ' ' flop' ' in a more or less flail-like condition from the leg. To remedy this either an apparatus is employed or sometimes the peroneal muscles or some of the flexor tendons are brought forward and the effort made to have them fulfil the function of the paralyzed extensors, which latter may also be shortened TFig, 598). If the calf muscles are paralyzed the contraction of the tibialis anterior and tibialis posterior pull up the arch and the contraction of the flexor brevis digitorum pulls the pillars closer together, therefore the heel descends, the arch ascends, and the plantar ligaments contract. If the extensor muscles are also paralyzed the toes drop and the anterior deformity is increased. The treatment of this condition is as yet not entirely settled. The plantar fascia must be divided and the pillars of the arch separated and the arch depressed by forcible manual or instrumental means. To retain the foot in its corrected position the tendo calcaneus is sometimes shortened. Jones makes an arthrodesis (ankylosis) of the midtarsal and ankle-joints ; Whitman excises the astragalus, pushes the foot back, and transplants the peroneal and posterior tibial tendons into the os calcis. The writer makes a trans\-erse section through the subastragaloid joint, pushes the foot back, and if necessary transplants the peroneal and posterior tibial tendons into the os calcis. Hallux valgus is a subluxation of the big toe outward. There is usually a deformity of the bone, the joint surface of the head of the first metatarsal being inclined obliquely out. As the toe becomes displaced outward the extensor hallucis longus by its contraction tends to increase the deformity. On the side of the head of the protruding metatarsal bone a bursa develops and becomes painful, forming a bunion. This bursa sometimes suppurates (Fig. 6oi). In some cases hallux valgus is due apparently to ill-shaped shoes, but in many cases, and these the worst, a rheumatic-gouty condition is the main factor.. In treatment the articular surface of the head of the first metatarsal bone is first resected. If desired a fascial flap can be interposed. This enables the toe to be brought straight. To keep it straight the tendon of the extensor hallucis is displaced inward and sewed in position with catgut, so that by its contraction it keeps the toe from again going outward. The toes are shorter than the fingers and are not so often injured. When injured or diseased healing may be delayed by the constant motion to which they are subjected. For this reason rest should be enforced in obstinate cases by the application of bandages or splints. Ingrown Nail. — This usually affects the big toe. It is caused commonly by the irritation and pressure of badly-shaped shoes. To cure it the side of the nail is sometimes removed. In so doing the nail should be removed well beyond the skin margin at the matrix otherwise it is reproduced in a distorted form. It requires several months for a new nail to grow out from the matrix. Packing cotton soaked in a solution of nitrate of silver, lo grains to the ounce, beneath the edge of the nail destroys the infection, lessens the pressure, and usually relieves the acute trouble in a few days. Hammer Toe. — This is a contraction of one of the toes, most often the second. The deformity is usually consecutive to the use of badly fitting shoes. Walsham (" Deformities of the Human Foot"), Shattock, and Anderson believe it to depend on a contraction of the plantar fibres of the lateral ligaments and glenoid ligament on the under side of the joint. Others hold it to be a contraction of the tendons. In treatment both conditions have to be considered. On pulling the toes the extensor tendon is put on the stretch, it should be divided, the remaining contractures are then either cut or broken by forcible stretching and the toe kept straight by band- Luxation of the Toes. — The big toe may become dislocated by direct violence; the lesion is often compound. The displacement is most often backward on the dorsum of the metatarsal bone. When the injury is not compound the same difficulty may be experienced in reducing it as occurs in dislocation of the thumb. The cause is the same. The head of the metatarsal bone becomes caught in the fibrous tissues of the capsule and between the two heads of the flexor brevis hallucis muscle. These each contain a sesamoid bone. The detachment of one of these heads from the base of the first phalanx may be necessary before replacement can be effected. Dislocation of the other individual toes is not nearly so rare as it is thought to be. It results from jumping from a height and landing, perhaps on an uneven surface, with the toes. The proximal phalanx may be displaced upon the metatarsal bone and the resulting pain is often considered to be merely a sprain. The head of the affected metatarsal bone can be felt projecting in the sole, the toe is shortened and the space between it and the adjacent one usually increased; but the diagnosis is difficult and is best established by means of a skiagraph. Reduction is difficult and even when accomplished is not apt to remain (Fig. 603). Resection may be required. Metatarsalgia or Morton's Disease. — This is a painful affection of one of the metatarsophalangeal joints, usually the fourth. Its pathology is not settled, but treatment is based on the supposition that the heads of the metatarsal bones become pressed together, usually by tight shoes. Relief is often afforded by separating the toes with cotton; by winding adhesive plaster — several thicknesses — around the affected toe; by supporting the arch by pads or plates; by inserting a narrow longitudinal pad; or by resection or amputation. Resection of the Metatarsophalangeal Joint. — In hallux valgus resection of the head of the metatarsal bone may give rise to a stiff joint. If the ankylosis is in a somewhat extended position, walking may not be impaired. Fig. 603. ^Dorsal luxation of the proximal phalanx of the second tee. Notice the shortening of the toe, its separatiDn from the third toe. and the fulness over the head of the metatarsal bone. (From a sketch by the author.) Excision of these joints may, and often does, give rise to a flail-like condition. The affected toe is deprived of its support and becomes displaced. Sometimes it gets beneath the adjoining toes and pain is caused by their superincumbent pressure. In other cases the toe is squeezed up above the level of the adjoining ones and is rubbed by the shoe above, causing painful corns. In either case the toe affected is a source of misery and not infrequently may require to be amputated. For these reasons excisions are seldom resorted to except in cases of hallux valgus. disarticulating. Amputation of the outer four toes at the metatarsophalangeal joint is a difficult operation because, unless one is well informed, it will be hard to strike the joint. It should be sought about i cm. (\| in.) behind the web on the dorsal aspect, and if approached on the plantar aspect especial care is to be exercised not to go too far back and search for it on the neck of the metatarsal bone (Fig. 604). _ As in the hand so also in the foot when the proximal phalanx is bent the prominence (or knuckle) is formed by the head of the proximal (metatarsal) bone. muscles of, 568 action of, as abductors and adductors, 570 action of, as flexors and extensors, 569 action of, in supporting tarsal arch, 568 plantar abscess, 575 extensors and flexors of fingers, 306 extensors and flexors of wrist, 308 pronators and supinators of hand, 310 nerves of , 3 1 7 Mayo incision for gastrectomy, 405 Mayo Robson's incision for kidney, 429 McBurney's incision for appendix, 382, 414 point, 374, 414 auditory, 20 auricularis magnus, 44, 52, 139 auriculotemporal branch of fifth, 3, 52 axillary (see Nerve, circumflex) circumflex, 265	318,873	common-pile/pre_1929_books_filtered	appliedanatomyco00davi	public_library	public_library_1929_dolma-0024.json.gz:1825	https://archive.org/download/appliedanatomyco00davi/appliedanatomyco00davi_djvu.txt
EnhuuM9R55gyk_nD	Finding the Invisibles: A True Story	1 Mind Control Mind Control What are we dealing with? Inbred psychopaths who are anti-human? Some ancient cult who has always been around – carefully tending the herds of slaves. We think we are free? When this book started a few years ago, I was naive. There were others like me who noticed something weird is going on. Some one or some thing is playing with us. WHY? Oh, it’s probably like a James Bond movie: a bad guy (Goldfinger) is trying to destroy a huge portion of the population. He’s a bad guy with unlimited money and lots of fancy technology. We just know he is alive and evil. Even high tech, as his weapons, right? But the real James Bond spyguys (and MI5) do exist. Maybe those movies were trying to tell us something? Maybe? We’re not told that is a possibility. We are raised with hope. Things will surely get better? Someone will save us? There is no safety in this system. None at all. Never has been. Not since 4500BC. (That is only a guess on when it began.) “The nasty situation we face is that we have long been ruled by a blood sacrifice cult, tied to slave ownership.” – Martin Geddes 2022 PSYCHOPATHS? “I was just thinking about the Matrix movie; how it gave you an idea of a system that co-exists within another system, manufactured by “outsiders” to serve their own purpose, where people like you and me are raised to be batteries, because “they” take energy from people to run their whole system in the Matrix. And it’s not too far from the truth in a certain way, like an analogy, because everything comes from us (you and me). Take all these multi-billionaire dollar corporations, and we really do have multi-trillionaires at the very, very top. That’s what Covid is; it’s an excuse under a wartime scenario to take over and change the whole system on behalf of those who already really rule it, and make it more efficient for them.” —Alan Watt (see Chapter 7) The Invisibles are my words to describe “them.” They reportedly have lived in the area on the map. They: Ancients, Minoans, Ancient families of Venice Who were the Venetian families? “Considering how some families had more than one Doge (Lord or Ruler), an even higher concentration is evident as EIGHT FAMILIES: Contarini, Badoer-Partecipazio, Mocenigo, Sanudo-Candiano, Memmo-Monegario, Morosini, Dandolo and Corner.” https://nobilitytitles.net(Doges of Venice were elected for life by the city-state’s aristocracy.) “They call themselves nobility.” They wereare the richest slave traders, bankers and merchants on the planet. Yes, in 2022. INVISIBLES? Where are they now? They are the invisible mega super-rich. Beyond your wildest dream – they are mega mega rich. Some call them Elite, or a Cabal. It’s only a handfull of people. They use exoteric and esoteric sorcery on us because it works. We cannot actually see them. The Invisibles are richer than the top one percent of the Elites we know about… over MANY centuries this group plundered, enslaved, amassed obscene wealth: they are unseen flying in private jets, living on islands, on yachts, in guarded palaces and kingdoms, and they are literally invisible. (There are two kinds of people: us and them, kings and serfs/slaves. Have’s and have nots.) They are responsible for genocides. They regularly change their names, every 100 years or so. Every 100 years or so, there is a new war or genocide ethnic cleansing. They are truly EMPIRE. They rule countries and governments. They control everything. They are ruthless. And they are looters and killers. [Esoteric means “not public or common knowledge” while exoteric refers to “knowledge or practices commonly taught or shared.” For example, mystical, magical, or occult practices are typically described as esoteric, while everything taught in public school is exoteric!] Killers? Psychopathic? Don’t believe me? I am not kidding around here. What would you do to stay in power (for centuries)? “Circles within circles, as Carroll Quigley talked about, that’s what you have, interconnecting circles, just like the symbol by the way of the Olympics; that’s what you’re seeing there. See how they connect? And that’s the symbol, the five, of course, it’s always the five, the five points interconnect that way. And that’s how you do it. You need five of them for different parts of controlling society. That’s what it stands for. “And that’s always been the foremost of an Elite’s agenda, is depopulating “unwanted” people. The useless eaters, as Lord Bertrand Russell called us all, basically. If you weren’t essential to the system, then they shouldn’t live.”—Alan Watt, Sept. 6, 2020 https://alanwattarchive.com/transcript-1792/ FYI: The Invisibles “Mafia” is owned and controlled as the wing that will do what can’t be done out in the open. BIG OIL and their BANKERS “There has been a well-founded notion since America’s inception that the European Rothschild-led Illuminati bankers have sought to bring America to its knees and return it to the fold of the Crown of England—whose power is derived from oligarchical remnants of the Roman Empire. Could a new global financial/military alliance—organized by the Eight Families—be emerging? The Rothschilds are the planet’s wealthiest clan, worth an estimated $100 trillion. They control Royal Dutch/Shell, BP, Anglo-American, BHP Billiton, Rio Tinto, Bank of America and scores of other global corporations and banks. They are the largest shareholders in the Bank of England, the Federal Reserve and most every private central bank in the world. They needed a footprint in the Middle East to protect their new oil concessions, which they procured through Four Horsemen fronts like the Iranian Consortium, Iraqi Petroleum Company and Saudi ARAMCO.”—Author Dean Henderson, Big Oil & Their Bankers(2007) https://www.amazon.com/Big-Their-Bankers-Persian-Gulf/dp/1453757732 and read “We are living in a world today in which the struggle between knowledge and ignorance, civilization and desecration, creation and destruction, is raging.”— Albert Litewka, Chairman of the Board, Los Angeles Review of Books If he reads this book, he’ll know why! From the John Trudell Documentary: Earth is a living entity. It is not in man’s destiny to destroy the Earth. That’s arrogance. We as human beings, if we take responsibility for our lives, and live our lives in a coherent manner, as coherent as we possibly can, anyway, then we will have an influence in curing this disease. But Earth will not allow (our complete destruction)… the antibiotic will come, in a planetary sense. If it means opening up the ozone [layer] and letting it wipe out civilized man, then the Earth will do that. The Earth will continue on. Maybe we should be developing our loyalties to this planet, this Earth, our future and our descendants, more than we should be to the governing political systems that have created all these problems. Most people are trying to find solutions to the problems, but they’re trying to do it within the confined abstractions of democracy. If we’re not willing to think objectively about our responsibilities towards our own descendants, then we will come up with no solutions. That will only perpetuate the enslavement and feeding.”—visit: johntrudell.com FINDING THE INVISIBLES How did this happen to us and why don’t we know anything about “them”? First: None of this has anything to do with religion. They use religion. Second: It has everything to do with army, arms, slaves, money, control and power. Over thousands and thousands of years, they are still hiding out. They move around. Drugs and oil cartels come later. We don’t know “them” because if we did know, things might turn bad for them, ugly, obviously. We’d find them. We’d hunt them down. You are going to get an ancient history lesson next: One group of “They” were given the name MINOANS by a rich bone collector from the UK. I call this “Minoan” civilization the beginning of the INVISIBLES but it may not be. It looks like it started with the Cycladic Civilization, an early Bronze Age culture on the Cyclades Islands in the Aegean Sea around 3200 BC. (more later) A few hundred years later, the Minoan Civilization” emerged” on the island of Crete. How does someone emerge or are they the same people who just MOVED? It looks like I am right actually. The Minoans are still considered the first advanced civilization in Europe because the diggers found evidence of them, according to what I read. A million years ago? Yes. Minoans? Who are THEY? The rich Minoans loved the “good life,” swimming, sports, enjoyed boxing, leaped giant bulls and built the world’s first ARENA. They were able to perfect and make obsidian daggers/knives and traded them widely. They made exquisite gold leaf jewelry, too. They also invented the MINOAN ECLIPSE CALCULATOR (that looks like terracotta frying pans with star designs) but the calculator’s precision is as exact as modern astronomy. [watch https://www.youtube.com/watch?v=qN8x2y5Zptk] THOUSANDS of YEARS AGO! Yep, they were busy for centuries building ocean-worthy sailing ships, huge palaces, cities and a language (Linear A) found on tablets that are still not deciphered. Someone from an earlier time taught them stuff, but who? Some say Egyptians. Some say they are Egyptians. Alert: Minoans aren’t GREEK! Yes, the island of Crete was once inhabited by a people named Minoans. A Welsh guy with a shovel and lots of money, Sir Arthur Evans conducted “digs,” aka excavations between 1900-1931, unearthing a palace, a large section of the Minoan city, and cemeteries. Evans purchased the land from its Turkish owners, which is interesting. Since then, more were excavated by the British School of Archaeology at Athens (in Greece.) The diggers interpret and report the findings to their liking, of course. Various items from these “digs” can be found at THE MET in New York City and online: www.metmuseum.org. [Sir Evans wasn’t the first to suspect that ancient ruins might be lying beneath the ground he dug up at Knossós, but he was the first to have a free hand at digging there, having bought most of the property from its Turkish owners during the 1890s. The Ottoman authorities had required such purchases, deliberately making them difficult to complete as a means of stalling off western archaeologists. They may have feared that the discovery of archaic ruins might increase Europe’s interest in knocking Crete loose from their empire.] BC is BIRTH OF CHRIST, you know that of course. AD is After Jesus Dies. I imagine Christ is wandering in dry deserts in sandals, not in thriving cities and civilizations. (Yet again: control the message: control the history.) I am pretty smart so I’ll keep using BC instead of how many millions of years ago this was. It’s my attempt to make all this understandable. Why was it called Minoan? Its name derives from Minos, either a dynastic title or the name of a particular ruler of Crete who has a place in Greek legend. No one really knows. This civilization was astonishingly advanced artistically and technologically and flourished from about 3000 BC to about 1100 BC. (Dates vary.) The Minoans were also the first literate people of Europe, so they claim. The Phaistos Disk is a disk of fired clay from the Minoan Palace of Phaistoson on Crete. It was discovered in 1908 and it possibly dates to the middle or late Minoan Bronze Age. This unique archaeological find remains an enigma; its purpose and meaning and even its original geographical place of manufacture remain disputed, making it one of the most famous mysteries of archaeology. The Minoans use Linear A symbols. The Minoan Palace Knossos was first discovered in 1878 by Greek archealogist Minos Kalokairinos. He found intensive habitation occurred in Crete with the first and second Minoan palaces, built along with luxurious houses, a hospice and various other structures: the South House, the House of the Chancel Screen, the Small Palace, the Caravanserai, the Royal Villa and the Temple-Tomb. The Minoans were traders who exported timber, olive oil, wine and dye to nearby Egypt, Syria, Cyprus and the Greek mainland. They imported metals and other raw materials, including copper, tin, ivory and precious stones. Read: https://www.history.com/topics/pre-history/bronze-age “Around 1900 BC, during the Middle Minoan period, Minoan civilization on Crete reached its apogee with the establishment of (city) centers, called palaces, that concentrated political and economic power, as well as artistic activity, and may have served as centers for the redistribution of agricultural commodities. Major palaces were built at Knossos and Mallia in the northern part of Crete, at Phaistos in the south, and at Zakros in the east. These palaces are distinguished by their arrangement around a paved central court and sophisticated masonry. The walls and floors of the palaces were often painted, and colorful frescoes depicted rituals or scenes of nature. There were sanitary facilities (bathrooms) as well as provisions for adequate lighting and ventilation. Living quarters of the palaces, like the better Minoan houses, were spacious.”— Colette Hemingway, independent researcher (www.metmuseum.org) THEIR NEIGHBORS? Around 1600 BC, the Mycenaean Civilization rose (arrived) on the Greek mainland, and their culture flourished too. Mycenaean power centers included Mycenae, Thebes, Sparta and Athens. People do migrate and move around and apparently DNA data is helping people finally realize this. ANY EMPIRE really really had to have their sorcery and army of priests-kings/lords working overtime—probably a carry-over from some earlier group of control-freak Elites and their magicians. After the Minoans dissolve (No one dissolves), Mycenaean Greece, the Hittite Empire in Turkey and Ancient Egypt “fall” within a short period of time. (They move!) Ancient cities were abandoned, trade routes were lost and literacy declined throughout the region. Some scholars believe a combination of natural catastrophes brought down several Bronze Age empires. (Not really!) Archaeological evidence suggests a succession of severe droughts in the eastern Mediterranean region over a 150-year period from 1250-1100 BC likely figured prominently in their collapse. Earthquakes, famine, and invasion by nomadic tribes may also have played a role. (Or they simply packed up and sailed to a new area, like Italy or Portugal or Spain. Why not? Think about it.) Evidence from sunken ships is painting a new picture of their movements. (Finally!) Before 2600 BC there are few known facts about how the Minoans lived….since that is a very long time ago. (Now the Greeks are making these sites their designated World Heritage Sites.) After seeing a painting with Minoans leading a pack of slaves (from Libya, it said) I am certain we are looking at yet another culture that practiced barbaric slavery. Handed down, of course. Who do you think built those palaces and served these people? “Until 1900 BC, the Minoans were not united under the yoke of any powerful landlords or centralized authority,” according to historian-blogger Hercynian Forest. In other words, Minoan Crete resembled the Near East and Nile Valley more than anything else. It’s also important to stress the fact that Minoans weren’t Greek at all: the Nile people first arrived at the scene that was the Aegean around 2000 BC, whereas the former had lived on Crete since roughly around 2900 BC.” [https://hercynianforest.medium.com] Forest writes: “In their early tholos tombs, no hierarchical differentiation was made between people. The Minoans pretty much kept to themselves in separate tribes and village communities.” Then something changed! After 1900 BC, the civilization gets a real kickstart. (Hint: Mycenaeans arrive) The Minoans began establishing colonies on Thera (Santorini), Kithira, Melos, Rhodes, Kea and other Aegean islands. The first king also came to power during this period. Ancient Crete was one of the first larger Thalassocracies, a maritime colonial empire with holdings attached to the coastline and to other islands.” Apparently elites keep merging, moving, rebuilding, still needing their palaces, slaves and cities—EMPIRE always does. What can we learn from the Minoan Empire? The Minoans are what led to Europe gaining much of the technology needed for basic civilizations, and are dubbed the “the first link in the European chain” by historian Will Durant. They built fortresses, great palaces with plumbing and heating, vast trade networks, a sports arena, and their own writing system. Wait… Someone had to teach them all this “technology.” (Hey, there are people who don’t have indoor plumbing now!) 👇 My thoughts Number One: They were given their name MINOAN by a rich British guy with a shovel. It’s a guess. Number two: I think they forget that, during the Bronze Age, the Minoans became very, very wealthy from copper trade—a key ingredient to Bronze Age. Number three: There is growing evidence that the copper they needed was actually traded from (possibly) Native Americans who mined surface copper deposits in the upper peninsula of Michigan. Ships go both ways—ancient Native people had boats, too. There is matching Minoan DNA evidence in some Ojibwe tribes, as well as Greek words in some Native American languages, and the coppers purity matches. So think about it… [Or the REAL evidence was burned up in library of Alexandria along with evidence of Minoan relations in South America and the “INVISIBLES” as nasty Romans destroyed all traces in order to fortify their own mighty Empire expansion in their fight against UK—until Rome was sacked. By then they forgot all about South America.] (Read Stannard’s book AMERICAN HOLOCAUST about the advanced civilizations just like the Minoans but in Central and South American that the Spaniards describe in detail.) Number four: The palace at Knossos was four stories high (incredible!) and the urban area around it was inhabited by 18,000 people in 2000 BC, leading it to be called the oldest city in Europe. At its peak three centuries later, a whooping 100,000 inhabitants lived in the palace and surrounding city. They even had paved roads! We have a HUGE mystery here with more questions than answers. Archaeologists and anthropologists dig through dirt, take bones, study DNA samples, examine (and loot) artifacts, write giant expensive history books, and attempt to construct a picture of our ancestors. Do they write it wrong on purpose, too? Nothing taught in high school even mentions Minoans. Did the Sea People exist? Yes. Sea People could be any of the groups of aggressive seafarers who invaded eastern Anatolia (Turkey today), Syria, Palestine, Cyprus, and Egypt toward the end of the Bronze Age, especially in the 13th century BC. They are held responsible for the destruction of old powers such as the Hittite Empire. Hmmm…Virtually nothing is known about the Sea People, with the only evidence of their existence coming from sparse contemporary sources, although the evidence is interpretive at best, and often debated by scholars. The historical narrative for identifying the Sea People stems primarily from seven Ancient Egyptian sources (with some information from Hittite sources), which names nine ancient cultures possibly responsible: the Denyen, the Ekwesh, the Lukka, the Peleset, the Shekelesh, the Sherden, the Teresh, the Tjeker, and the Weshesh (further proposals from narratives in other civilisations includes the Etruscans, Trojans, Philistines, Mycenaens, and even Minoans). (That would require someone to write a new book on those nine ancient cultures.) [https://www.heritagedaily.com/2020/10/who-were-the-sea-people/135782] QUESTIONABLE The Prehistoric Period—or when there was human life before records documented human activity—roughly dates from 2.5 million years ago to 1200 BC. It’s categorized in three archaeological periods: the Stone Age, Bronze Age and Iron Age. The earliest and longest period of the Stone Age is called the Paleolithic Age. This comes from the Greek word Palaios, meaning “long ago” or “old,” and lithos, meaning “stone.” At the beginning of the Old Stone Age, approximately 4.4 million years ago, the first human ancestors made their appearance on earth, so they say. (I am beginning to seriously doubt this… and all their timelines.) The oldest (tin alloy) BRONZES date back to around 4500 BC and were found at an archaeological site, Pločnik in the country called Serbia today. Before this, the most common tool 6500 years ago was the stone axe. This replacement of stone tools with bronze was an important indicator of the start of the Bronze Age in different parts of the world. The bronze casting process allowed for more possibilities to manufacture weapons and tools. SIX THOUSAND YEARS AGO—are you comprehending this? We are living in two different worlds even today. (That was their plan.) Some things do not add up—and the BC dates are simply calculations (a good guess)… What we can be sure of, there is definite archaeological evidence Minoan settlements and palaces were obliterated and suffered material damage from fire. Theories surrounding the downfall of Minoan Crete: societal structure breaking down due to fierce competition for wealth, natural environmental havoc and invading Mycenaeans, and the volcanic eruption of Thera somewhere between 1642 and 1540 BC. (Or they simply packed up and moved on… and we know they did!) Sci-Fi and Hollywood movies (especially) corrupted any real ancient history we think we may know (or any we’d re-examine) making them into fictions and myths (all by design). Confused? I am. With historians, it’s all guesses, conjecture and theories, and calculation based on burials and artifacts that are also theories. Fishy, I’d say. And also confusing… and sometimes boring. Try and find ONE ACCURATE BOOK on Minoans… I wish you luck. THEM, too? Slavers? MINOAN INCOME: The recorded history of SLAVERY in Ancient Greece begins during the Mycenaean civilization (1600-1100 BC), as indicated in numerous tablets unearthed at Pylo . QUITE TELLING: Greek slaves came from the different cities of Greece, while others came from Egypt and Persia. Servitude was widespread in Greek antiquity. Athens alone was home to an estimated 60,000–80,000 slaves during the fifth and fourth centuries BC, with each household having an average of three or four enslaved people attached to it. https://greekreporter.com/2021/06/18/slavery-ancient-greece/ MINOAN UPDATE (my comments) The Palace of Knossos is Crete’s most visited historical tourist attraction and was the capital of Minoan Crete. (Indeed) Its ruins were discovered in 1900 by the British archaeologist Sir Arthur Evans. (wrong) He spent 35 years excavating and reconstructing it. (After he bought it, sure he was digging.) The reconstruction continues to be controversial because many archaeologists believe that he sacrificed accuracy during the project. (Of course he did that) The lies they tell us… OMG. 5000 YEARS AGO? I thought we were all hairy primitive hunter-gatherers not able to communicate with each other!?! Highlights of The Palace of Knossos include the fresco of a charging bull in the North Entrance, the Grand Staircase (four flights of gypsum steps to the royal apartments in the eastern wing, the Queen’s Megaron; the queen’s bedroom that features a dolphin fresco and a sophisticated bathroom and drainage system, the Fresco Room with views of the palace grounds from the west wing’s upper floor and copies of the palace’s most famous art works, the Giant Pithoi or massive clay jars that were used to store wine, oil, and grain, the Prince of the Lilies Fresco that depicts a young man adorned in lilies and peacock feathers, and the South Portico; a palace entrance anchored by a massive open staircase decorated with frescoes. Size of ancient Minoan leaping bulls? Archaeological evidence has now uncovered that the type of bull used by ancient Minoan bull leapers was a cross-breed giant aurochs bull, now extinct in Europe. It had a shoulder height of over 6 feet and a hoof size similar to the size of a human head. Phaestos is Crete’s second most important Minoan palace city after Knossos. It has a similar layout to Knossos and was also built atop a previously destroyed older palace. The Central Court is well preserved and conveys the magnificence of the palace. Views of the Mesara Plain and Mt. Psiloritis can be seen from Phaestos. Agia Triada was most likely a small palace or a royal villa. The setting provides mountain and sea views. Many masterpieces of Minoan art can be found here. The Palace of Malia includes a series of storage rooms to eight circular pits believed to have been grain silos. Past the silos is the palace’s Central Court. In the ground is the Kernos Stone, a disc that may have had a religious function. The most important rooms include the Pillar Crypt, the Grand Staircase and the Loggia, most likely used for ceremonial purposes. Buildings north of the central court held workshops and storage rooms. Read more: https://www.greekboston.com/travel/minoan-sites-crete/ AMAZING NEWS April 17, 2022 : A team of experts from the Ephorate of Underwater Antiquities, University of Geneva, and Swiss School of Archaeology were looking for remnants of the oldest village in Europe. They were hoping for a tiny 8,000-year-old town. Instead, they found a 12-acre settlement approximately 4,500 years old. The settlement had stone defensive structures, paved surfaces, towers, and many other artifacts. Archaeologists stated that these defensive structures were more complex than any seen in Bronze Age ruins. For this reason, they believe they found a city ahead of its time. As University of Geneva Professor Julien Beck stated, the foundations were “of a massive nature, unknown in Greece until now.” This indicates there might be a lot more depth and complexity to ancient Greek civilization than we know. (you think?) Greek Reporter (photo source) recently published an article on the city of Pavlopetri, discovered off the southern tip of the Peloponnese. The city lies just 13 feet underwater. Archaeologists have recreated what the 5,000 year old city may have looked like using modern technology. This has led them to realize that the sunken lost city was a quite complex urban center at its time. [www.greekreporter.com] Experts estimate Pavlopetri was built around 3000 BC, and sunk around 1100 BC due to earthquakes common to this region. This timeline is why archaeologists have found the city to be extremely significant. Pavlopetri is the only found underwater city that sunk before Plato’s story of Atlantis (just a theory). Archaeologists marveled at the city’s sophisticated urban planning. Pavlopetri had roads, two-story houses with gardens, a water management system, and even a central town square. As manager of the Pavlopetri Underwater Archaeology Project, Dr. Jon Henderson said, “there are older sunken sites in the world but none can be considered to be planned towns such as this, which is why it is unique.” Despite all our modern technology, only 1% of the ocean floor has been surveyed. Imagine how many sunken cities still layout there, waiting to be found. READ: https://greekreporter.com/2022/04/17/ancient-cities-lost-under-aegean-sea-greece/ FYI: When I was a kid, the first fiction book I checked out of the library was MOONSPINNERS by Mary Stewart, a mystery novel set in Crete. I always wanted to go there, especially after reading that book as a kid. PLOT: A teenager encounters romance, intrigue and a search for stolen jewels during her visit to the island of Crete. The main character Nicola Ferris stumbles across a murderous crime involving a young English woman and a group of people tied together by blood. Google Books Originally published: 1962. The moonspinners were there, out on the track, walking the mountains of Crete, making the night safe, spinning the light away.—Mary Stewart BULL: Minoan Terracotta vase in the form of a bull’s head ca. 1450–1400 B.C. Minoan This vase is a type of rhyton, or libation vase. The offering was poured through the hole in the animal’s muzzle. The vase was filled either by immersion in a large container or through the hole on the head. Using the principle of the siphon, liquid would not flow out as long as the opening at the top was closed with the thumb. May 2022: The entire month I will be posting Minoan history at : https://dwellerhome.blogspot.com/ “See, one of the reasons I do what I do is to try to break some of the trash-demon spells the Sorcerarchy are constantly spewing out at us. Another is a vain and probably hopeless quest to warn people that the spirit world is very, very real and is not your personal Disneyland. The supernatural (and sorcery) is very real and very not to be trifled with, as I keep shouting helplessly into the void.—Author Christopher Knowles, Secret Sun blog Mind Controllers: A Primer on Oligarch Empire Writer David Gosselin— https://davidgosselin.substack.com Excerpt Indeed, a lot of the Empire’s strategy is quite simple. One can trace the metamorphosis of this slime mold across the ages. The Anglo-American system today is in fact a historical outgrowth of what was once the Venetian Empire. The Anglo-American system is simply the latest expression of that, which emerged from the old British Empire system, which was itself a result of the ancient families of Venice having to migrate from the lagoons around the Adriatic Sea for strategic purposes. The Modern American “Deep State” is really just a continuation of that system. But America was founded as a refuge from the old degenerate European aristocratic system. While that memory is waning, there is still some faint glimmer. The American population has in many ways become the most dumbed-down, but that’s largely because it was the population most subjected to psychological warfare and social engineering. The European nations still never really shook off the old oligarchical forms of thinking. This time, it’s just technocratic feudalism. One of the main differences with previous empires and the old colonial model is the more systemic use of social engineering and epistemological warfare. Much of the empire is not an empire of boots on the ground enforcement, it’s an Empire of the Mind. The elite schools like the London School of Economics, Oxford, and all their Ivy League counterparts in the USA and elsewhere constitute a web of nodes which spread the ideas that ultimate create an ideologically very indoctrinated managerial class. These are the ivy-league graduates, “Rhodes Scholars” and related ideological spawn. For example, most of the economic theories excreted by these institutions, “Free Trade,” “globalization,” “supply-side economics,”etc. are all just essentially variations on the old British East India company model of controlling finance, trade, etc. Not much has changed. The private merchant banking system is the great fraud of our current financial architecture. That being said, these imperial systems do always crash, and they always end up having to cannibalize their host populations in order to keep the looting system going. We’re seeing that now with the current zombie banking system and the infinite money-printing now required to keep the Trans-Atlantic banking system alive. “The Great Reset” and related “Fourth Industrial Revolution” vision are just the latest Utopian wet dream these oligarchs have cooked up in order to keep their system going. It is very simple: they want to force a massive contraction of the industrial world i.e. the economic and technological platforms required to sustain our current level of population, and bring the population down to around 1 billion people. They have computer “models” and “experts” which tell us this is the carrying capacity for the planet. It’s all based on an axiomatically closed-system outlook on the universe. While they try to convince everyone of pseudo-scientic ideas like “carrying capacity,” they are adamantly against Fusion power and all advanced forms of atomic energy for the simple reason that it would mean the end of their reign over the third world countries, which are supposed to be kept backwards with little infrastructure, little access to science and technology, and therefore remain cheap labor producers for the “advanced” technocratic utopias they hope to maintain. To really defeat this imperial system, the Malthusian outlook needs to be defeated. The Malthusian system* simply dictates a law of universal entropy, a zero sum game, where everyone is stuck warring over limited resources. As a result, it can’t allow for the kinds of fundamental breakthroughs that overturn their geopolitical chess board and the artificial limits of their closed system. This is the great fraud, and one of the main ideologies being used to advance a “Great Reset” global depopulation agenda. Most of what they say is just a cover for this. It’s pretty simple. [Source: https://davidgosselin.substack.co] * The main features of the farce of Malthusian theory are: That population was growing at a geometrical progression while food production was growing at arithmetical progression. That there is a tendency for all living things to grow beyond the food available to them. ( MORE LATER) Why Is NOBODY Talking About the Mass Resignations of Major CEOs? One strange thing about all the CEO’s stepping down is that most of those companies stood to gain “bigly” from the pandemic lockdowns and yes, many did. Some 195 CEOs stepped down in the first two months of 2021, according to recruiting firm Challenger, Gray & Christmas. To date by July 2020, well over 1300 CEOs from massive corporations throughout the world had stepped down from their positions in the preceding twelve months. (2022) CEO PSYCHOPATHS “…Those who run the world financially, the dominant MINORITY, are a hereditary group (Invisibles) who will employ psychopaths and put them in place as CEOs. The intelligent-type psychopaths are savvy as to what’s going on; they’re careful not to end up afoul of the law if possible. But they’re dedicated psychopaths. If you pay them well, they’ll serve you well. They can join very important private clubs. They might even get knighted. A lot of them actually did in the past. If you look at the people who got knighted in Britain for the last maybe 150 years, most of them were merchant bankers, people who, believe you me, were in a real tough business. Nice folk just don’t get ahead. It doesn’t happen that way. You’ve got to be ruthless. And there are folk who are psychopaths who definitely are ruthless, who are very successful in the business world, ruthlessly lending to governments. Often Britain knighted them and they’d end up being up there amongst the lords and ladies, so they’d intermarry each other. So, the psychopaths marrying into the psychopathic realm have a good chance, especially in the lifestyle and the culture within the hereditary family groups of raising another good psychopath to takeover. Intergenerational psychopathy is very important. All countries have it too.” —the late author Alan Watt, https://alanwattarchive.com/transcript-1792/ ALAN WATT: The Deceit of the Elite (2020) “I’ve mentioned it before; there’s a freezing of the mind that comes into play when real danger starts to seep into your mind that you might be done for. With a lot of folk actually, it’s paralytic. They think, “This cannot be happening in real life to me. We live in a civilized society.” They still know that there’s massive, massive fields in different parts of the Soviet Union, with layers and layers and layers of bodies that were mass executed. The people’s army did it. You know the people’s army: On behalf of the people. They always take over the same authority. It’s for the good of the people, so on behalf of the people, we will execute you, because you are enemies of the State. You are enemies of the people. “And I knew this stuff was coming, because I’d given talks back in the 90s on the incredible psychological studies that had already been done on us, and other authors, long before even Quigley came out in the 50s and 60s on television, talking about the studies on the public that were pretty well perfected. And they knew that using techniques back then, they could really drastically, and very quickly alter human behavior, and make us do things that perhaps we shouldn’t to do. Or make us accept things we shouldn’t accept. But today, it’s massive. I mean, your own tax money throws millions and billions across the world to these think tanks and study groups in universities that all do these joint projects with those that eventually grab the patents, whatever they discover, and new techniques: they have patents on techniques, by the way, for those who don’t know it, on ways to manipulate you. And they do. And it’s very, very effective, and incredibly effective, when you understand that most folk will take the path of least resistance at all times.—Alan Watt CTTM (Blurb, i.e. Educational Talk) “The Deceit of Elite” Sept 6, 2020 It’s all a game——to them, anyway… TLH What about the psychopaths of Eugenics? “Several U.S. foundations financed eugenic research, including the Carnegie Institution and Rockefeller Foundation, which gave grants in the 1930s for eugenic research at the Galton Laboratory at University College in London and to the Cornell Medical School in New York. The term “eugenics” was first described in the psychological work of Francis Galton. A prominent British statistician during the late 19th century, Galton analyzed the variation and distribution of mental characteristics in groups of individuals in Great Britain. Heavily influenced by the evolutionary theory of his half-cousin, Charles Darwin, Galton believed that genius was inherited, that could be traced from one generation to the next. In 1883 that he introduced the concept of “eugenics”: the breeding of the intelligent elite to improve the overall mental and physical quality of a human population’s stock.”—Yale Scholar John Doyle [https://elischolar.library.yale.edu] Read his paper! The Bush family joined John D. Rockefeller and the British Royal Family in sponsoring the eugenics initiatives that gave rise to Hitler’s racial hygiene programs. Prescott Bush was later found guilty of trading with the Nazis during WWII. According to court records, the Rockefeller family and their Standard Oil Company supported Hitler more than they did the allies during the war. In fact, one judge declared Rockefeller guilty of treason. Dr. Gary Glum documented the insidious eugenics programs to create a “superior race,” which were initially sponsored not by Adolph Hitler, but by the American elite like the Rockefeller, Carnegie, Harriman, Morgan, DuPont, Kellogg and Bush families. In 1952, Frederick Osborn, an officer of the American Eugenics Society, assisted John D. Rockefeller III in organizing the Population Council and served as its first administrator. [http://www.renewamerica.com/columns/spingola/100128#fn8#fn8] Once upon a time, whatever your religion, Armageddon was the Property of the Gods… until August 6, 1945, that is, when a lone B-29 bomber, the Enola Gay (named after its pilot’s mother), dropped the first atomic bomb on the city of Hiroshima, essentially obliterating it. Thought of another way, however, we humans took the power to end the world (at least as we’ve known it) out of the hands of the gods in the 19th century when the fossil-fuel based industrialization of Planet Earth began in earnest in Great Britain. In other words, credit our cleverness. In the space of a mere 200 or so years, we’ve developed two different ways of devastating or even ending our life on this planet. Consider that a genuine accomplishment for humanity.—Tom Englehart, https://tomdispatch.com A Recovering Environmentalist (Me, too) “Humanity has lost the battle against climate change. That is what Paul Kingsnorth thinks. The former environmental activist believes that we can’t stop climate change anymore. Kingsnorth has withdrawn to Ireland on a unspoilt part of the earth. You could say that he lives now at the end of the world. A portrait of an end-time thinker who nevertheless does not give up hope and continues to believe in the power of nature. Kingsnorth stood early on the barricades as a conservationist. He resisted the insatiable hunger of the globalized world for more land, resources and things in England and on the other side of the world in Papa New Guinea. But at some point, he came to terms that he had to revisit his belief that humanity could save the world. In his bundled essays “Confessions of a recovering environmentalist” (2017) he describes how some weak-kneed accountants of this world hollowed out the “green movement” from the inside and exchanged the barricades for ties and conference tables. Limiting CO2 emissions became the new gospel because it was measurable and countable. But according to Kingsnorth, that is an illusion. He thinks that in his victory rush, the green movement of today exchanges the remaining wild nature for a wind or solar panel farm. The battle is lost. He founded the “Dark Mountain Project” in which writers, poets and artists are looking for a different view of the end of the world, based on the connection between man and nature. He exchanged his clenched fist and protesting voice for an inner, literary search for the question of what makes us human and what our place is on this magical planet. PLEASE WATCH: https://youtu.be/Q_s8Vo00Xug PAUL’s website: https://www.paulkingsnorth.net $813 BILLION? WAR MAKES MONEY FOR BANKERS William Astore writes in 2022: “If you’re an American 21 years of age or younger, you’ve never known a time when your country hasn’t been at war, even if, thanks to the end of the draft in the previous century, you stand no chance of being called to arms yourself. You’ve never known a time of “normal” defense budgets. You have no conception of what military demobilization, no less peacetime might actually be like. Your normal is only reflected in the Biden administration’s staggering $813 billion Pentagon budget proposal for the next fiscal year. Naturally, many congressional Republicans are already clamoring for even higher military spending.” https://tomdispatch.com/what-would-it-take-for-military-spending-in-america-to-go-down Remember: The US federal government is free to print all the money it needs to pay its own government debts. THINK: The Invisibles, curses, churches, mind control, magic, secrecy, slavery, sorcery hierarchy, mental illness, psychopaths, demonology: it’s all so similar, isn’t it? I wouldn’t pooh-pooh things that easily if I were you.	8,927	common-pile/pressbooks_filtered	https://pressbooks.pub/cosmicglue/chapter/chapter-1/	pressbooks	pressbooks-0000.json.gz:29300	https://pressbooks.pub/cosmicglue/chapter/chapter-1/
tY7hz1gXNZaN7a-6	High masonry dams / by John B. McMaster, C. E. ...	No. 23.-THE FATIGUE OF METALS UNDER REPEATED STRAINS, with various Tables of Results of Ex periments. From the German of Prof. Ludwig Spangenberg. With a Preface by S. H. Shreve No. 24.-A PRACTICAL TREATISE ON THE TEETH OF WHEELS, with the Theory of the Use of Robin son's Odontograph. By Prof. S. W. Robinson. E. Waring. Jr. No. 32.-CABLE MAKING FOR SUSPENSION BRIDGES, as exemplified in the construction of the East River Bridge. By Wilhelm Hildenbrand, C. E. PREFACE. In the preparation of the following treatise three points have been constantly in view, to avoid as far as possible all purely theoretical discussion, to discover the most economical forms of profiles consistent with perfect strength, and to consider none that have not, after repeated practical application demon strated their excellence, even under the severest tests. To treat the subject, however, in a logical way, it has been found best to begin with a theoretical determination of the strongest and at the same time least expensive form of profile, and afterwards to modify this to meet the re quirements that arise in actual construction. The theoretical type is, as I have attempted to show, that composed of a vertical face on the inner, and a concave surface on the outer side. Of this, there are, of course, an almost unlimited number of possible modifications. But when we impose the condition of economy, the number of really useful ones dwindle down to less than half a dozen. Those treated of in the present work number four. The first (il lustrated in Fig. 9), is, beyond all doubt, the very best. It has indeed, been often urged against this type of profile, that it is difficult to determine with accuracy the equations of the logarithmic curves forming the bounding faces, as also to cut the facing stones to such a curve. As to the first objection, no equations can surely be simpler than those we have given, while the second is a difficulty most easily removed, not by argument, but by de termination. The three other types are also profiles of equal resistance, and are treated of so fully in the work as to call for no remark here. It will also be observed that I have touched very lightly on the sliding of dams on their founda tion, or of any portion of them along a hori zontal joint. This has been done, because, though I have examined as fully as possible the causes that have led to the destruction of dams of all style of profile and of all heights, both abroad and in this country, I have been able to find extremely few that may justly be said to have yielded by sliding. It has almost in variably been by revolving about an axis near the outer face, caused by taking too great a limit of vertical pressure, and thus throwing the line of resistance, when full, too far out ward from the centre of thickness. HIGH MASONEY DAMS, THE subject proposed for consideration in the following work is that of the pro file of masonry dams of such height, breadth and general dimensions as would be required for reservoir purposes, or for impounding the waters of rivers and large streams for mill or irrigation use. We would observe, however, at the out set, that as this matter has already been treated with such fullness by several writers, and especially by MM. Delocre and Sazilly — to whose excellent "me moirs " we are greatly indebted — we can hope to add little that is really new, but shall endeavor, by drawing from many sources, to supply our own deficiency, to diminish the errors of others, and thus obtain results very much more accurate on ourselves. Before, however, we take up the con sideration of the matter of the form of profile that shall combine the greatest strength with the least amount of mate rial, there are a number of important points to be considered somewhat in de tail. Thus, it is necessary, in the first place, that we should know the forces to which dams are subjected, their kind? whether constant or variable, the meth ods of determining their direction and calculating their intensity, and the ef fects they are likely to produce, and these matters being known, we may pass to the consideration of the conditions of stability, first when the dam has only its own weight to support, and, secondly, when it has to withstand both its own weight and the pressure of the water. We may then deduce a theoretical profile of equal resistance, and, finally, adopt one so modified by the requirements of practice and suggestion of experience, that it shall serve as a profile type, ful- filling to the utmost the requirements of great strength and stability, beauty of outline and economy of material. Now, it becomes evident, after a mo ment's consideration, that there are but two forces that may at any time be re garded as acting with vigor on a dam, and these are, the weight of the mason ry, cement and other material composing the structure, and the pressure or thrust of the water whose flow it checks. The first becomes, to all intents and purposes, a constant quantity as soon as the dam is finished, and continues so for ever after, acting vertically downwards through the centre of gravity of the mass. But, on the other hand, the latter force is one of great variability. For, as its intensity at any moment depends on the depth or head of water behind the dam, increasing as the water deepens and1 decreasing as the water falls, and the head of water, especially in reservoirs used for mill or irrigation purposes, be ing subject to frequent rise and fall, it follows that this thrust must be consid- ered as a variable quantity and treated accordingly. It is, moreover, to be ob served, that this thrust acts horizontally, and unlike the weight, is not distributed uniformly over the entire face of the dam, being almost, if not quite, zero at the point where the water cuts the masonry, and growing greater and greater as we descend towards the foot of the dam. The weight, it is true, also increases as we go from the top to the bottom, yet, if we suppose the dam to be at any point . ten feet thick, the pressure on any hori zontal section taken at that point will be everywhere the same, and this is by no means the case if we take an area ten feet square on the water face of the dam, and against which the fluid presses. In order that the dam may not yield under the first force, and be thrown down by the greatness of its own weight, it is necessary, should the structure be of such height, or the material of such heaviness, that the pressure per unit of surface at any horizontal section is in excess of the "limit of pressure" for masonry, that the surface of the section be increased so that the pressure being distributed over a more extended area the load at each unit of surface shall be less. The second force, or thrust of the water, is resisted at any point by the weight of the masonry above that point, and by the friction of the stones, which is of course dependent on the weight. Some resistance is indeed afforded by the bonding power of the hydraulic mortar used in setting the stones, but this is so ^small that precautions of safety require that it shall in all calculations be disre garded entirely. But these two forces, the weight act ing vertically downwards and the thrust of the water acting horizontally, counter act each other to a certain extent, and give rise to a third power or resultant, the position of which, as regards the base, will determine the stability of the dam. To illustrate, let A B C D (Fig. 1) repre sent the profile of a dam composed of horizontal courses of masonry bedded on each other, and K the centre of gravi- FIG, I. ty of the mass, lying above the line E F. Represent by K G the direction and in tensity of the weight of AF, and by KP the direction and intensity of the thrust of the water from D to F. Then, constructing in the usual way the paral lelogram P K Gr R, we shall have for the resultant of KP and KG, the line KR. Now, supposing the dam to be perfectly secure as to its weight, the force P of the water can demolish the wall only, when, exceeding the weight and friction K G, it shoves the mass AF along the joint E F, or causes it to rotate about an axis through E. Which of these motions, the slipping or rotating, shall take place depends entirely on the magnitude and direction of the resultant K R. If the pressure of the water is so large com pared with the weight that the angle RK G, which the resultant makes with the vertical, is larger than the angle of friction (32° for masonry on masonry), the mass A F will then slide along the line EF; while if the position of the re sultant is such that it passes without the base B C, then rotation will take place about the axis of E. Of these two mo tions, the latter is in practice the most likely to occur, inasmuch as in nine cases out of ten when rotation does take place it does so about some point as E', nearer the resultant than E, because the press ure concentrated at E, breaks off the stone, and thus throws the axis of rota tion nearer the resultant. The condition of stability then, in dams that do not transmit laterally to the sides of the valley, the pressure they sus tain (and this is the ease in all large dams) is, that they must resist this press- ure at every point by their own weight. If the material employed were of con siderable resisting power, as well as the soil of the foundation, and if there were between them an unlimited degree of adhesion, the only condition of stability to be fulfilled would be, as we have just seen, to give the wall such a profile that the resultant of the thrust of the water and the weight of the dam shall pass within the polygon of the base. But this condition is not found sufficient in practice ; the material and the soil of the foundation will, in fact, support only a limited pressure (depending on their nature), and they have not between them an unlimited degree of adhesion. Hence, the two following indispensable conditions : 1° The several courses of masonry in the wall must be incapable of slipping the one over the other, and the wall in capable of sliding on its base. 2° In no point of the structure may the material employed, or the soil of the foundation be required to bear too great STABILITY AS TO SLIPPING. We shall take up first the condition of stability as to the slipping of the va rious courses of masonry, and then pass to that of the entire dam. The first thing to be now determined, is the hori zontal thrust of the water. Suppose A B C D (Fig. 2) to represent the face of a dam pressed by water, and let h=A J denote the height; a= J C the projection of the slope of the dam on the horizon tal plane; and, finally, let 1= A B denote the length of the dam, and b= A G is breadth across the top. Then will the vertical pressure of the water on the face A B C D be expressed by tained as follows : Let E P, in Fig. 2, represent the nor mal pressure of the water on the surface A C, which we will call F, and resolve it into two components, one vertical E P', and one horizontal E P", and call them respectively P' and P". Then expressing the angle P E P" made by the horizontal component P" and the normal E P, by a Now, let a projection A'B' C D, of the surface A B 0 D, be made on a plane at right angles to P", and call the area of the projected surface F'. Then will F' = F cos AC A', or since the angle of inclination A C A' of the surface to its projection is equal to the angle P E P" = a, between the normal to A C, and the perpendicular to A7 C, we shall From the principles of mechanics, we know that the pressure P of water on any given area is the product of the area,^the height h of the water, and its density y, so that in the present instance F being the area of the surface A B C D, we shall have for the value of P the ex pression P=F h y, and this substituted in equation 4 gives Therefore is the pressure with which water presses against a surface in a given direction equal to the weight of a column of water, which has for its base the pro jection of the surface pressed, and for height the depth of the centre of gravi ty of the surface below the top of the water. We see, moreover, from the above, that since the projection at right angles to the vertical is the horizontal, and the projection at right angles to the horizontal is the vertical projection, the vertical component of the pressure of water against a surface may be found if the horizontal projection, or its trace, be considered as the surface pressed, and, on the other hand, the horizontal com ponent may be found if the vertical pro jection of the surface, or its trace, be considered as the surface pressed. Applying these two principles to the case of Fig. 2, and replacing F' in equa tion 5, by its value 111, we shall have for the horizontal thrust of the water on the face A B C D of the dam the equation P" — ^hly, and in the same way the vertical component will be found to be equal to P'— -J a h I y. Now, b being the breadth of the dam, and ar the projec tion of the slope G K, and y' the density of the masonry composing the dam, it is evident that the area of K C E G will water, or We have seen, however, that the force which tends to counteract the push of the water, and on which the stability as to slipping must therefore depend, is equal to this weight of the dam increas ed by the friction of the stones. De noting this co-efficient of friction by/, we shall then have for the force to push the dam forward the expression In order therefore that the dam may not be pushed away by the water, we must have one of the two following conditions fulfilled ; either For safety, we may further assume that the base of the dam is quite per meable, in which case there is (on the principle that a pressure in one direction produces an equal pressure in the oppo site direction) a pressure from below up wards equal to (2 b + a + af) Ihy, equal the weight of the dam, and as this is, of course, to be subtracted from the above, we have finally, only to the sliding of the entire dam on its foundation, but also to any particular layer of stone at any point in the dam. The value of the co-efficient of friction f will of course be very different in cases where we consider the stability of differ ent parts of the wall, from that in cases where we consider the dam to slide on an earthty foundation. In the former case, it is that of masonry on masonry, in the latter, that of masonry on earth, and in general clay. In fact, it may be restricted almost solely to clay, because in a sandy, porous or yielding soil, it is better, on principles of economy, not to build a dam, but a dyke. For masonry on masonry, or, indeed, bricks on bricks, we may with safety take the co-efficient of friction as equal to .67 ; for masonry on dry clay .51; but for masonry on wetted clay the co-efficient falls to .33. A few examples may, perhaps, serve to illustrate the above remarks. We shall confine ourselves first to the case of rotation about one of the joints, as that is really the most likely one to arise in practice : FlG.U. A D dam, constructed say of brickwork weighing 112 pounds per cubic foot. Let the thickness on top be 10 feet, and that at the base 20 feet, required to find the perpendicular height, the dam must have in order that, when the water stands at the brim, the wall shall be just on the point of turning about the point B under the pressure of the water. Denote by h the height of the dam, or the quantity we are in search of, = C D. Now, by Ibs., and the moment of this pressure with reference to the point B is 1680 h XBE. Before we can obtain this mo ment, then, we must find the value of B E, and this is found as follows : Again, preserving the same dimensions, let it be required to find the " modulus of stability" of a masonry dam of the profile, shown in Fig. 1, the stone weigh ing 200 pounds per cubic foot. Draw from the middle of the top A D to the middle of the base B C the line R Y, and take its length as 45 feet, and the depth of the water behind the dam, 44 feet. The value of N g we have just found. VS is evidently equal toYC— SO, or 10 — 5 = 5. In the triangle RYS, we also have R S'=R V'-VS2, or RS3= (45)2-(5)2; hence RS=44.38. Substi tuting these values in the above propor tion, we shall have : The weight or pressure of the wall acting through the centre of gravity g of the dam is, as we have already seen, and that of the water 44X1X^X62.5 = 60500 Ibs. If now we denote by P the " centre of pressure " of the water, that is to say, that point where a single pressure will counterbalance the thrust of the water against the entire face D C of the dam, then P=C P=^=14.6 feet. The quantity we are in search of, the modulus of stability of the wall is the ratio of T B to T O. The value of T B we have already, and may obtain that of T O from the proportion that the press ure of the dam is to the height of the centre of pressure (P) of the water above the base of the dam as the press ure of the water is to the entire pressure of the water acting on its centre of press ure P. Thus : In a well built structure, this quantity should never be less than .5, hence, as in the present case, the modulus is somewhat above this value, we are justified in re garding the dam as a perfectly stable structure, when the water is not over 44 feet in depth. In these considerations, we have taken no account of the resistance offered by the adhesion of the mortar. Should this be taken into account — and it is al ways best that it should not — then equa tion 9 will require to be modified some what as follows : Let H equal the dis tance of the centre of gravity of a layer of stones below the top of the dam. The shove of the water tending to throw down this portion of the dam is, as we 6 is merely a short notation for ly. The forces resisting this shove are the friction of the two layers sliding on each other, and the adhesion of the masonry. The first is proportional to the weight of the masonry above the stratum in question, and the second or adhesion of the mason- ry is proportional to the thickness of the dam at this point. Representing as before the co-efficient of friction by/, by c the cohesion of the mortar per unit of surface, by s the area of the upper sur face of the course next below, and by 5 the thickness of the dam at this section, we shall have for the resistance R to sliding : the dam on its foundation will rarely, if ever arise, when the dam is founded on a rock, for in that case the value of the co-efficient of friction will be the same for the horizontal section of the founda tion as for any section of the masonryIt is, however, very likely to arise when ever circumstances will not enable us to lay the foundation on bed rock. In such cases the soil will almost always be of an argillaceous nature, for, should it prove to be of a gravelly, sandy or very permeable character, the employment of some common form of dyke will be much preferable to the construction of a dam. We may, therefore, reasonably assume that in all cases where the foundation course does not rest on a rock surface, it will be laid on argillaceous soil, and as this will readily give, under the action of water, a slippery slimy surface, we must assume a co-efficient of friction very much less than that used for masonry on masonry. With this point kept clearly in view, the conditions of stability will be given by the above equations. Yet there are one or two other considerations that must not be overlooked. Thus, as the stability will depend in large meas ure on the lateral resistance of the soil, it is not sufficient 'to be sure that this resistance is large enough to prevent the sliding of the wall, but is also necessary to be assured that at any point of the front of the foundation wall, the normal pressure does not exce'ed the limit R/ of which the soil or the wall is susceptible. Again, in order to prevent any slipping likely to arise from the lateral compres sion of the earth, it is not necessary to interpose any packing between the face of the wall and that of the ditch, and, finally, that in all cases it never comes amiss to " step " the rock or the earth on which the foundation course rests, a mat ter to be considered more in detail here after. SECOND CONDITION OF STABILITY. To return now to the second condition of stability, namely, that in no point of the structure may the material employ ed, or the soil of the foundation, be re- sent the profile of a dam. Then from the principles we have already establish ed, it follows that any section of this, equal in length to a lineal unit, may be considered as subject to the action of two forces, which are, respectively, the vertical component P of the resultant of the weight of the structure above that unit, and the horizontal pressure or thrust of the water, and the horizontal component F of the thrust of the water. In the section A B C D, these two forces act through the centre of gravity G, and produce a resultant of their own which cuts the A B at E. This latter resultant R may therefore be regarded as applied directly to the point E, and resolved into two components, one vertical and equal to the force P, and one horizontal and equal to the force F. The horizontal force tends to slide the wall along the base AB. This we have considered. The vertical spread^ itself over the base from the extremity B, which is nearest the point of application of the resultant, according to the well known decreasing law. Now, in all works on mechanics, we have given a formula which applies to a homogenous rectangle, pressed by a force acting upon one of the symmetri cal axis, and this is : and , 1 Where N is the entire load or pressure, and D, the entire area of the surface pressed. In the case we are considering, the quantity 1ST in equations cc and /?, is, of course, represented by P the vertical component. iQ, by I, if by this letter we designate the breadth of the base A B, and if we denote the distance E B by u, then will the quantity n in equations oc is the same thing when ^^< J L We have seen that the condition of stability re quires that some limit, R', should be placed on the pressure each superficial unit is expected to bear. The pressure at the point B, must therefore be less or never greater than R', and we shall have according as u is greater or less than J 19 And this condition is to be fulfilled for each section made in the profile, neglect ing the force of cohesion of the mortar which is unfavorable to resistance. yet further modification, if we introduce into the calculation the maximum height A that may be given to a wall with ver tical faces, so that the pressure upon^the base shall not exceed the limit B/ of safety. Indeed, if we represent the den sity of the masonry, or the weight per cubic yard by d, we shall have R' = tf'A, and the above equation become : 3 u ud The conditions expressed in these equations would be quite sufficient if the water was always up to the top of the dam, but as this is by no means always the case, the wall must be capable, even when the dam is quite empty, of sup porting its own weight without being subject at any point to a pressure per unit of surface exceeding the limit d'A. In this case the resultant of all the forces acting on the wall is reduced to the weight P', and denoting by K A, the distance from the resultant passing through the centre of gravity of Fig. (3) to the nearest extremity A of the base, by u, the pressure at A, will be given according to circumstances by equations 11 or 12, and the stability of the wall will require that one of the relations ex pressed in equations 15 or 16 be satisfied when P' is substituted for P. OWN WEIGHT TO CAEEY. In order to study under all conditions, the question we are now about to con sider, it is perhaps well to inquire, in the first place, what form it is most conven ient to give a dam having only its own weight to carry, in order that each point of the masonry shall not be subjected to a pressure larger than the limit of safety, and then to determine the alterations which economy require to be made in this assumed profile. It is evident, to begin with, that when the height of the dam is such that it does not go over the limit A (i. e. the greatest height we can give to a vertical wall, without the press ure on the base becoming larger than H', we shall be quite justified in giving the dam vertical facings, and that, in such case, the load for each unit of sur face at the lower part will be somewhat less than d'A, or at least, never greater. Again, we know that whenever the press ure on a horizontal surface of masonry is larger than the limit of safety, we may correct this, by enlarging the area of the surface pressed, and so lessen the load on each superficial unit. And these are the two fundamental principles of dam construction, and may be summed up in brief as follows : If we are construct ing a dam of a height equal to or less than A, and having only its own weight to support, it is a safe practice to give it vertical facings from top to bottom. If, however, we are constructing a dam of a height greater than A, yet having only its own weight to support, we must make the faces vertical for a distance from the top equal to A, and from this point to the base slope them outward. A dam constructed on this latter prin ciple would give a profile similar to that in Fig. 4. From the summit A B to the section C D, the pressure per superficial therefore from A to C the face is verti cal, but below C D, the load exceeds the limit and increasing at each section to the base, and hence from C to Y the face is sloping. And just here we are met by the great question in dam construction that of profile. Should the bulging portion C Y Y'D, be bounded by right lines as in Fig. 4, should it be stepped, should it be curved, and if so, should the bound ing curves be logarithmic curves, simple or compound ? these are questions we propose to consider. It is an easy matter to determine the force to be given to the facing, so that the condition that the load per unit of horizontal surface shall never go over the limit tf'A, shall be satisfied. To do this, we may choose arbitrarily one face and then determine the other, but if we desire to use the minimum of material consistent with perfect safety, then the wall must be symmetrical as to its axis. In such a case as that illustrated in Fig. 4 — that of a high masonry dam, whose height is greater than A — the slopes D N Y' and C M Y, ought to satisfy the 'requirement that, if in any section, as M 1ST, the load per surface unit is equal to any given quantity, the pressure will be the same for any other section as m' ri ', infinitely near to it. This will be fulfilled, if the increase given to the base is proportional to the increase of press ure, or as the profile is to be made sym metrical to the axis O S, if the increase of the half surface L 1ST or L M is pro portional to the increase of load on that half surface. If we denote by P the pressure on L 1ST, arising from the weight of the structure above, and a the surface of this section, then, it is evident, the above condition will be expressed by K.da. . . . 17. In which K is a constant quantity, and denotes the limit of pressure on the unit of surface or d'A. Again, by #, de note the dimensions of the dam in the direction perpendicular to the section we are concerned with, and by x the length of the half section LN, or, to express it mathematically, the abscissa of the curve or line sought (i.e. DN Y'), and finally, by y, the distance of MN from a horizontal line taken as the axis of x. Then the surface a will equal to bx, and consequently an increase of surface as da in equation 17, will be expressed by Now, from this equation we see that, the curve being referred to rectangular axes, one of the co-ordinates is equal to the logarithm of the other, and, hence, the curve must be a logarithmic curve. Here then we have one property of the curve D N Y. To find in the next place the origin of its co-ordinates, we may make in the foregoing equations #0 = A, in which case we shall have : From this last relation it is quite ap parent that the origin of co-ordinates is to be taken at a point where the value of x is equal to that of A, and in this point the tangent to the curve makes an angle of 45° with the axis of x. Re turning now to equation 19, let us replace y0 and x0 by their respective values, given in equation 20, when we shall have : This curve, when constructed, will give the form of the facing of a wall of in definite height for which the pressure per unit of surface equals the limit of pressure K. It is not to be forgotten in in making use of equation 21, that the direction in which ?/'s are usually esti mated has been reversed ; in other words, y when positive is to be estimat ed downwards, and when negative up wards, or in the direction of L O. Fig. 5 represents this curve constructed, by assuming the pressure limit or K as 132,000 Ibs., and the density of the masonry as double that of water. In such a profile, as Fig. 4 has, the sloping faces below C D being bounded by right lines, we may obtain the neces sary breadth of the base Y Y', as soon as we have determined the height and * We may also pass from the Naperian to the common system, by multiplying the Naperian logarithm by the modulus of the common system, which is 0.434294. Its logarithm is 9.63TT84. Fic.5. the breadth at top. Denote by 1) the breadth at top A B ; by h the distance AC=A, and by h' the distance from C to the base Y Y'; by $' the density of the masonry, and by x the quantity we are seeking for, or the base YY'. Then we shall have : The quantity h in this equation, which is merely another expression for the quantity A,, has been determined by a number of investigators, but the most reliable results are those obtained by the French engineers,* who, in the construc tion of their great masonry dams, such as Furens, have taken the limit of press ure K at 60,000 kilogrammes, or about 132,000 Ibs. per square metre, and K being equal to tf'A, and tf' being equal to 2,000 kilogrommes, A becomes equal to 30 metres. As we shall hereafter see, however, the limit of pressure varies for the outer and inner face of the dam. If, again, the profile adopted be such as is illustrated in Fig. 3, that is to say, if the faces of the dam slope continu ously from the top to the bottom, then the thickness or breadth of the base will evidently be obtained by dividing the product of the height of the wall and its thickness on top by the difference be tween 2 A and the height. For dr A or the limit of pressure is equal to the area of the profile, multiplied by the density of the masonry divided by the thickness of the base. In the figure, the area is plainly equal to half the sum of the two parallel sides by the altitude, and denot ing this latter by H, we shall, therefore,, have : The conditions which govern the con struction of such a dam, and the height to which it is safe to build it, become from this equation quite apparent, should and the base of the wall would spread out to infinity. Should we, upon the other hand, make H greater than 2 A, then A would become negative, and hence it follows that the greatest height we can give to a masonry dam with straight sides equally inclined from the summit and not go over the limit of re sistance for masonry, is equal to twice that of a wall with vertical sides. Yet, within this limit, such a profile for a masonry dam of any height, occasions a gross waste of material. This becomes strikingly apparent, if we compare the breadth of base of a dam constructed with inclined faces from top to bottom, with that of a dam of the same height, but having a profile such as that of Fig. 4. Suppose each dam to be 30 metres high and 5 metres thick on top; required the thickness at the base. For the first ease, using equation 23, we have : For the second form of profile, we use equation 22, and have, since the quantity h equals A, the same value, or x = 5 metres. The saving thus affected when the dams are of great height becomes simply enormous. The difference, however, be tween the profile when the dam below C D (Fig. 4) is bounded by right lines, and when bounded by logarithmic curves, such as shown in Fig. 6, is not so marked as in the cases just considered, yet is considerable. To take but one case in illustration, a dam of a profile such as Fig. 6 illustrates, with the faces below CD bounded by curves, would require (equation 21) a breadth of base equal to 9.739 metres, the height and thickness at top being as before, 50 and 5 metres respectively, while, as we have just seen, if the faces below C D were right lines, the base would be 10 metres. Such, in brief , is the relative merit of these three forms of profile, for a dam having nearly its own weight to support. In practice, however, such a dam can, of course, never exist, and it thus becomes necessary to take into consideration the second condition, or that of a dam sup porting a charge of water. PRESSURE OF WATER. And here, again, we are to throw aside, at first, all practical considerations, and determine a theoretical profile of equal resistance, one in every part of which the pressure shall not be greater than the limit R'. For this purpose we return to the two equations, deduced some time back, which express the conditions of stability for a dam resisting the thrust of water, and neglecting the signs > and < and the values corresponding to them, take only those corresponding to the sign of =. We then have the two following equations : 49 , If we now replace the quantities w, I and P, by their respective values, ex pressed in functions of the height of the dam, we may readily deduce two equa tions which, on examination, will show two things. 1°. That the profile offering the least thickness, consistent with the conditions of stability, is one in which the side turned towards the water, has a vertical face, and the side turned from the water, or the outer face of the wall, a concave face. 2°. That as the height increases, the thickness increases less rapidly, so that in a wall constructed with a vertical face on the water side and a curved face on the other side, and so planned that it shall satisfy the conditions of stability as to its base will present an excess of strength for the surplus of height. Fig. 7 is the profile of a dam of this description. It will be observed, more over, that in this form of profile the thickness of the wall at the top is zero This, of course, in practice is never ad- missible, inasmuch as it presupposes the water to be at all times in a perfectly quiescent state, and thus makes no al lowance for the very considerable force of the waves raised by the wind. It is, therefore, necessary, whatever the profile, to give the dam quite a thickness at the summit, in general, about fifteen feet, is a good width, as it thus enables us to construct a footpath and roadway on the top of the dam, which is quite a conven ience. Before we consider any other modifi cations, it may be well to determine as nearly as possible the co-ordinates of the concave curve forming the outer face. For this purpose we will take the verti cal face A B as the axis of #, and for the axis of y, a perpendicular to this pass ing through the point A, and call it AD. Anywhere on the curve we will take a point C, and denote its co-ordinates B C •=y and C e=x ; then the relation exist ing between x and y will give the equa tion of the curve. Now, as we have already seen, the wall is subject to the action of two forces, the weight of the - dam P, which acts vertically downwards through the centre of gravity and the horizontal thrust T of the water. These two forces produce a resultant R, which cuts the base of the dam in this case at the point H. This resultant, therefore, may be regarded as applied directly to the point H and resolved into two com ponents, HP and H 0, respectively, par allel to O P and O T. We have also seen by equation 5 that the horizontal thrust of the water is equal to And in the same way Returning now to equations 24 and 25, we find that the quantity I is equal to y, and that we have therefore to determine the value of u in functions of x and of y. Now u equals H C and H C = K C - K H. The triangles O P R and O K H, moreover, being equiangular triangles are similar, and have their like sides proportional, and Replacing in the 29th equation the values of T and P, as obtained in the 27th and 28th equations, we have : But KG is evidently equal to y— B K, in which B K is the distance from the centre of gravity of the surface ABC to the vertical axis of x or A B. This distance is equal to the sum of the mo ments of the areas such as a b c d, or Thus, then, we have the value of u in functions of x and y, and substituting this value for u in equation 24, and re membering that 1= 7/, we have : But here a new difficulty presents it self, for no sooner do we attempt to in tegrate equations 34 and 35, than we see it is quite impossible to perform the in tegration by any exact method. We may, however, obtain an approximately correct solution by finding the value of y in a series of functions x. Treating equation 34 by this method we obtain, says M. Delocre, for y the value These equations, as it is quite apparent, are of no earthly value for practical pur poses, and we shall, therefore, drop all further consideration of them. Indeed, if it were possible to obtain the equations of the curve AmC, by a' short and sim ple process of integration, a moment's reflection will show that such a profile as that illustrated in Fig. 7 would not be suitable for practical use. For this pro file has been calculated on the hypothesis that the dam is always to support a head of water equal to its height, and in this case the pressure on any horizontal sec tion as m n will, it is quite true, not ex ceed the limit R. But as it happens that the dam is very likely to be at times empty, the profile must be such that, full or empty, the pressure on any section as m n shall not be greater than R. We know that this limit will not be exceeded for the face of the wall bounded by A m C, and it thus remains to consider only the vertical face A B. On reference to the calculations we have made rela tive to the profile of walls having only their own weight to support, it becomes noticeable that the limit will soon be passed if the wall is slightly raised. Supposing this limit to be reached at the point n^ we are forced for the sake of stability to depart from the vertical be low this point, to give the water face a swelling or bulging surface, and -thus adopt a profile similar to that illustrated in Fig. 8. This profile is supposed to fulfill the conditions that, at any section as de, taken below mn^ the pressure at the point e, the dam being full, will be same limit of pressure, R. This last modification, moreover, is one of no small importance, as it enables us to correct some of the chief errors in which the theoretical consideration has unavoidably led us, and thus to approach nearer to the end in view ; the determi nation of a profile of equal resistance suit- able to practical requirements. If the two curves mel> and ndT) could be readily obtained by the above formula^he profile of Fig. 8 would answer almost all necess ary conditionsas testability and economy; but they cannot. It therefore remains to do the next best thing, and to replace the curved surfaces, by polygonal surfaces of as small sides as possible — in order that they may approach reasonably near to the curves — and then determine the equations of these sides of the polygons; or to adopt a similar method to find the equations of the two curves in question. This we shall now endeavor to do. It is, howrever, to be remarked that there are two notable instances of the use of the form of profile, shown in Fig. 8 ; that of the dam at Furens, and that con structed on the Ban, a tributary of the Gier, by M. Mongolfier. Each of these we shall consider later. As this form of profile, therefore, has been illustrated, and its economy, dura bility and strength fully tested in the case of the dam at Furens, and in that over the Ban, we shall now under take its investigation, and determine a series of formulae for the calculation of the logarithmic curves forming the inner and outer face of the dam, and, finally, the establishment of a profile type suitable for dams of various heights. Our investigation, moreover, is to be based on the practical experience of MM. Graeff and Mongolfier, in the con struction of the dams of Furens and over the Ban, and the brief but thorough report of Professor Rankine on this form of profile, to many parts of which we are greatly indebted. In the first place, as to the limit of pressure, two questions naturally present themselves: first, what shall be the great est limit of pressure we may with safety assume ? and secondly, is the same limit to be adopted for the inner as for the outer face of the structure ? As regards the first question, it becomes evident at a glance that the limit R', to which any point in the dam may be subjected with out thereby endangering stability, will de- pend, to no small extent, on the nature of the stone, cement, or mortar used. Yet here, as in other cases where mason ry is used, it is possible to assign a gen eral limit, based upon practical experi ence, which should not in any case be overstepped, and if possible rarely equal ed. In the two dams to which we have above alluded, the limit of the pressure was taken at 6 kilogrammes per square centimetre, or 60,000 kilogrammes to the square metre, or taking the kilogramme as equal to 2.20485 pounds, 132.291 Ibs. per square metre, which in turn is equal to 1.1954 square yards. In Spain, how ever, and indeed, we believe in some in stances in France, the limit of pressure has been taken so high as 14 kilogrammes per centimetre,and the dam found to stand well, but in the majority of cases at from 6 k. to 8.50k., generally at 6 k., per square centimetre. We may express this press ure in another form much more familiar to English engineers, and take as the limit of pressure for each square foot or square yard, a column of masonry hav- ing that area for a base and a height of 160 feet. This is also based on experi ence, as it is well known that good rubble masonry will, when laid in strong hy draulic cement, bear with safety the pressure arising from the weight of a column 160 feet in height. Taking,, again, the density of masonry as double that of water, this pressure would be equaled by a water column 320 feet high, or a pressure per square foot of 20,000 pounds. The next question as to whether the limit of pressure should be the same, both for the inner and outer face of the dam, seems to be viewed very differently by different engineers, and to admit in practice of a variety of solutions. In the dams constructed by M. Graeff and M. Mongolfier, and in the theoretical profiles offered by M. de Sazilly and M. Delocre, the same limit of pressure was adopted for each face, and the discussion of the formulae thus much simplified. Yet there seems to be much ground for departing from this observance and for adopting two limits, one for the outer and one for the inner face, provided that the dam has such a logarithmic curve of profile as that we are considering. It is evident that the vertical pressure along these two faces is, at different times, un equal ; that when the water is of great depth behind the dam the outer face is more severely strained than the inner, and that when the water is very low, and the dam has little more than its own weight to resist, directly the opposite re sult takes place and the severest strain is found along the inner face. It is like wise evident that the pressure at any point along these faces must, in all cases, be of necessity in the direction of the tangent to the surface at that place. If the face is vertical, the quantity we de rive by the usual equations is the true vertical pressure, or rather the entire pressure. But when the surface slopes off from the vertical, as it does in this case, the pressure is in the direction of the tangent, is inclined to the vertical, and the quantity which the formula gives us is not the entire pressure, but only its vertical component. The whole or real pressure of course, exceeds this vertical component, by a ratio which grows greater and greater as we pass down the face of the dam to parts where the bat ter, or slope of the face, departs more and more largely from the vertical. But the outer face has a very much greater batter than the inner, and the water be ing high, is subjected to a much greater strain, so that, to equalize matters, and not allow the outer face, when the dam is full, to suffer a- greater strain than the inner face when the dam is empty, it becc mes most expedient to take a lower limit for the vertical pressure at the out er than we do for the intensity of the vertical pressure at the inner face. Adopting this view, it remains to fix these two limits of vertical pressure. On the inner face, it is clear, where the slope deviates so very little from the vertical that, for all intents and purposes, it may be safely neglected, we may take that we have already fixed upon, namely, the 67 . weight of a column of masonry 160 feet high. For the outer face, we may take a pressure whose vertical component is represented by the weight of a masonry column 120 feet high, a pressure which has been deduced from the practical ex amples of M. Graeff. The next matter to be taken into account is that of tension, which must, so far as possible, be avoided in every portion of the dam. And this brings us to the consideration of the " lines of re sistance," of which in structures subject ed to such varying pressure, there are of necessity two ; one for the condition that the dam or reservoir is full of water, and one for the condition that it is empty. As in the case of earth retaining walls and buttresses, these are lines passing through the centre of gravity of each course of masonry, and may, when the faces of the dam are rectilinear, be found by any of the formulas used for such purposes. They bear, therefore, intimate relations to the stability of the dam, the latter decreasing as they depart from the centre of thickness and near the faces. They also bear relation to the tension, and in order that the latter may not be come appreciable in any part of the structure, they must not deviate at any point from the line passing through the centres of thickness, either outward when the dam is full, or inward when empty, by a distance greater than onesixth of the thickness at that point. FOR BOUNDING FACES. Let Fig. 9 represent the profile of a dam bound by logarithmic curves, the various equations relative to which we wish to find. Let the vertical line A S represent the asymptote of the curves, and taking the origin of co-ordinates at the top of the dam, represent by x all horizontal, and by y all vertical measurements, by b the breadth or thickness of the dam across the top, and by b' the breadth at any other place lower down. Also let s represent the sub-tangent common to the two curves, and represented in the figure by that part of the asymptote contained between F and G. As to the lines of resistance let their deviation from the middle of the thickness when the dam is full and empty be expressed by the letters r and r' re spectively, and by R and R/ denote the limits of pressure ; the first for the out er, the second for the inner face. Now, adopting Professor Rankine's method of procedure, it becomes evident that if the thickness across the top be expressed by #, then the thickness at any other portion of the dam lower down, and at a distance y below the top, will be expressed by the equation in which e is the modulus of the common system of logarithms, or 0.434294. To apply this equation therefore to practice, it is necessary to know the value of the sub-tangent, the thickness across the top and the vertical distances of different points on the face of the dam below the axis of X. These latter points are, of course, assumed at random, and have in the present case been taken five feet apart. As to the thickness at the top it has been taken at eighteen feet. In the dams already alluded to (those of MM. Sazilly and Mongolfier) with the height of 50 and 42 metres respectively, and a limit of pressure of 60,000 kilogrammes per square metre, the thickness across the top is, in the former, five, and in latter, five and seven-tenths metres, which, expressed in feet, gives for the one 16.4 and for the other 18.6 feet. But in this instance we have slightly enlarged on the thicknesses used by thflse engi neers, in order to produce a profile suit ed for a dam required to resist not only the thrust of water, but also that of ice when carried down by spring freshets. The determination of the sub-tangent s is not so obvious, but may be found by mate value of , which substituted in the formula of Prof. Rankine, gives a corrected value of V, and a sub-tangent equal to 80 feet. If, then, adopting this breadth of 18 feet on top, we desire to find that at a point thirty feet below, we may write equation : which is to be measured off in such wise that thirteen-fourteenths of it shall lie on the down stream or outer side of the asymptote, and the remaining one-four teenth on the up stream or inner side. Taking other values for y and proceed ing in precisely the same way, we thus obtain any desired number of points through which must pass the logarithmic curves that form the faces of the dam. This done and the curve drawn, the next step is to determine the lines of resist- ance when the dam is full and when it is empty. To begin with the latter case, the dam being empty, the deviation of the line of resistance from the middle of the thickness will evidently be inward or towards the up stream side of the dam. This deviation we have expressed by the letter r' ', and if we wish to find its value for a horizontal section of the dam taken 50 feet below the top, we pro ceed as follows. Let z denote the dis tance hg or the deviation of the centre line of the thickness outward from the axis A S, and by zf the deviation of the same line from the same axis at the top of the dam. Referring to Fig. 9, the distance we wish to find is evidently equal to g h minus the deviation of the centre of thickness of the top of the dam from A S, divided by 2, or Because the dam having only its own weight to carry, the line of resistance must cut the line ghiu a point vertically of the structure above g A. The thickness of the dam where y is fifty feet is found from equation 39 to be 33.63 feet ; the centre of thickness 16.81, and the value of z or the devia tion of this centre from the axis A S is 14.41 feet. That of zr or the deviation at the summit of the dam is 7.72 feet, from which it follows that (eq. 40) r' = 3.35 feet. It is in this way that the values of r', given below in Table A, have been calculated. It is next necessary to determine an equation from which to find the values of r, or the amount by which the line of resistance deviates outward from the centre of thickness when the dam is full. It is evident this deviation will depend upon three things, the moment of the horizontal thrust of the water, above the section at which we wish to find r, the weight of the dam above this same sec tion, and the amount by which the line of resistance is moved inward when the dam has only its own weight to carry, so that if we divide the moment of the thrust by the weight, and subtract the quantity r', we shall at once have the value of r. The thrust of the water above any horizontal section of the dam is, as we have already seen by equation what is the same thing, if we express by w the ratio in which the masonry is heavier than the water, and take, as is usual, this ratio as 2, we shall have for the moment (expressed by m) of the horizontal thrust of the water, Qw 12 The weight of any lineal unit of the dam above the section may be found most simply by the calculus. Thus giv ing to y and b the same signification as before, and taking the weight of a cubic unit of masonry as the unit of weight, This equation gives for the value of r at the distance fifty feet below the top, the quantity 5.18 feet, which, as it falls below one-sixth of the thickness at this point, we are justified in considering the ly consistent with stability. But, to make assurance doubly sure, we may apply a final test as to stability, by calculating the amount of vertical pressure at various points along both the inner and outer faces, and comparing the results with the limit of pressure, which, it will be remembered, has been fixed for the inner face at weight of a column of masonry 160 feet in height, and for the outer face at that of a col umn 120 feet high. This matter we have already considered at length, and have deduced two equations, 13 and 14, which as they are perfectly suited to the present case, we shall not delay to deduce others, but alter them to suit the notation of Fig. 9. Thus altered they are, calling p and p' the pressures at the outer and inner face respectively, and P and P' the lim it at these same faces — While for pr we have two others precise ly similar, with the exception that P in equation 45 is changed to P'. It may, perhaps, be well to again remark that the first or second value of p in equtaion 45 is to be used according as the value of it is greater or less than one-third of the thickness, and that in all such pro files as that of Fig. 9, the quantity u de notes the distance from the outer face to the line of resistance when the dam supports a charge of water, and from the inner face to the line of resistance when the dam or reservoir is empty. To illus trate by one example, let it be required to find the vertical pressure at the point C, on the outer face of the dam (Fig. 9), situated fifty feet below the top. By re ferring to Table A, we see that b' is equal to 33.63 feet, that the outward deviation of the line of resistance is 4.98 feet, and that u must therefore be 11.83 feet. The quantity W=s (£' — £) is 1250.4. Since 33.637 33.63 Thus showing that the pressure is but a little more than half the limiting press ure. Precisely the same operation re peated, with u equal to 13.46 feet, will give the amount of vertical pressure at the inner face at a point fifty feet below the top, the dam supporting only its own weight. This pressure is thus found to be equal to a column of masonry 59.4 feet in height. The area of the entire profile or of any portion of it, included between two horizontal sections, may be found by tak ing the difference between the thickness of the dam at these two sections, and multiplying the difference by the subtangent. For it is evident from the figure that, if b equals the thickness of a point y feet from the top, then this thickness multiplied by the differential of the height and integrated between the limits y and zero, is the area, and the expression for the area becomes s (bf — b). In the notation we have used b means the thickness of the dam across the top, but in calculating the area of any portion of the profile not bounded by the top thickness, the quantity b is to be understood to mean the smaller of the two thicknesses which bound the area. That is to say, if we wish to find the area of that portion of the profile included between horizontal sections taken at thirty and eighty feet below the top, b represents the thickness at the former section, and we have 80 (48.93 — 26.19) = 1819.2 square feet. Having the area, the solid contents and weight for any length of the dam are of course readily found. The areas for sixteen dif ferent sections of the profile, each hav ing the top of the dam for one side, have been calculated in this way, and will be found entered in the last column of Table A. The first column of this table gives the distances in feet of the sec tions estimated from the top downwards, the second the thickness of the dam at these sections, the third the deviation of the line of resistance outward when the reservoir is full, the fourth the deviation inward when empty, and the last the areas. 9200.00 It is perhaps unnecessary to call at tention to the fact, that this form of profile has been calculated with a view to its serving as a profile type for dams of any height, great or small, whose faces are logarithmic curves. For a dam, then, of which the height is thirty feet, that portion of Fig 9, above the line marked 30, is the proper* profile : for one eighty feet in height, that por tion above the line marked 80, and so for each succeeding section. It presents again many strong points not found in dams of the usual rectilinear profile, which are especially deserving of con sideration when damming a river or valley of great breath and depth. Of these not the least is its economy of material, which, as we shall hereafter see, is very great as compared with that of stepped or sloping profiles ; while the curves of the two faces are so gradual that no great mechanical difficulty can arise in cutting the facings. Another matter, which, in the dams of Furens and the Ban was not taken into account, that of tension, has here been considered and the profile so determined that when the reservoir is full the tension on the outer face shall not at any point be greater than it is on the inner face when empty. Ban, a tributary of the Gier, in Fig. 11. The former has a height of fifty metres with a breadth on top of 5.70 metres, FIG. 11. and a limit of pressure of six kilogrammes per square centimetre. The latter has a height of forty-two metres, a thickness on top of five metres, with the same limit of pressure as the Furens dam. By a comparison however, of the profile of the former with that part of the profile of the Furens which lies above the limit A B we see that the thickness has been very considerably reduced, while if we extend the profile to fifty metres and then compare it with the Furens, we find that the pressure nowhere exceeds 8 kilogrammes to the square centimetre. To return now to the modifications of which this type of profile is susceptible. PROFILE. On a moments inspection of Fig. 8, it is readily seen that, as the inner curve does not anywhere depart very far from the asymptot AS, the first and simplest modification of this curve is to replace it by a right line and thus make the inner face vertical from top to bottom. But the outer curve if treated in like manner, and replaced by a right line, would give us a form of profile which, though it possessed no more thickness at the bot tom than was absolutely necessary to withstand the vertical pressure, would at every other point, possess a thickness greatly in excess of the requisite amount, and thus occasion a prodigious waste of masonry. We must therefore, break this continuous slope and substitute for one long line two or more shorter ones each of which makes a different angle with the vertical. Limiting our atten tion for the present to the first case, and replacing the two logarithmic curves in Fig. 9 by lines, — the inner curve by one vertical, and the outer by two inclined — we have produced for us a profile of the form illustrated in Figs. 12 and 13. The question that first presents itself in the discussion of such a profile, is evidently how far down the outer face the point C is to be taken. It comprises indeed, the entire discussion. Of course, it is a great advantage, so far as the saving of ma terial is concerned, to throw this point as low as possible, but this is limited by the condition, so necessary to secure stability, that when the reservoir is full the vertical pressure at C shall not be greater than the limiting quantity R. Having determined the thickness across the top, which preserving our previous notation, we will call b, the quantities to be determined are first, the vertical dis tance of the point C below the top, and second the thickness of the dam at this point, or what is perhaps more easily obtained the excess of the thickness at C over the thickness at the top, A B. The the total thickness D C we will represent by 5', and express the excess of thickness by v. By W, denote the weight of the part A B C D (Fig. 14), and by F, the horizontal thrust of the water above D. These two forces act through the centre of gravity O, the former vertically downward and represented in Fig. 14 by the line O P ; the latter horizontally and represented in direction and inten sity by O F. These two produce a re sultant which cuts the base at V, and this point may therefore be regarded as the point of applica tion. From this relation, as we have K C may be found by the equation ex pressing the relation that the moment of the weight of A B C D, with respect to C, is equal to the sum of the moments of the two parts ABVD and BVC into which the area of A B C D may be divided. The moment of the weight of A B C D, with respect to C, is evidently of these equations express the relation that when the reservoir is full the verti cal pressure at the point C (Fig. 14) shall be equal to the limit K. But we must also take into consideration the inner face, and find an equation express ing the relation that the reservoir being empty, the pressure at Dr shall not ex ceed the limit R. In this case, the face being vertical, the pressure of the water does not exist, and the force P, or the weight of this portion of the dam, acts downwards through the centre of gravi ty, and By combining 51 and 54, or 52 and 55, we may readily obtain the value of y and v, which are the two quantities we wish to find. It is moreover to be re marked that A in the above equations is found by dividing the limit of vertical pressure at 0 and D by the ratio in which the masonry is heavier than water. Thus in calculating the profile of Fig. 12, we have first reduced the limit of vertical pressure per unit of surface from pounds to kilogrammes, and taking the density of water, as given in the French tables, as 1000 kilo grammes and the density of masonry as double that of water or 2000 kilo- very simple number, whereas had we re tained the pressure as expressed in pounds, we would have had a much larger one to handle. In Fig. 13 how ever, in order to produce a profile of what may be considered as a type of the greatest boldness consistent with safety, we have taken the limit of vertical pressure at 14 kilogrammes per square centimetre, which as we have already stated has been used in several instances in France and Spain. This increases the value of A to 70. The thickness across the top is in each case the same as in that of the profile illustrated in Fig. 9 ; namely, eighteen feet, but the height of that in Fig. 12 has been reduced to ninety feet. The height AD of the upper part A B C D and the value of v corresponding to it have been found by combining equations 51 and 54. The lower part, by the same equation, by substituting for y the difference between the height A D of the upper part and the entire height of the dam. The deviation of the line of resistance when the reservoir is full may also be found as follows. Let A B C D in Fig. 15, represent either the upper or lower part of the dam whose profile is given in Fig. 13, and let it be desired to find the amount of deviation at any section as E F. By O represent the centre of. gravity of A B F E, then will O B, repre sent the resultant of the two forces act ing on this portion of the dam, and the distance we wish to find will be E S. We will suppose also, in order to cover all cases that the water stands at X. Also let A B = 5 ; A X = Z. AE = y ; E S = a; ; E W = A ; and the inclination of the sloping side B C, to the vertical be denoted by cc ; by # the density of the masonry and by 6' that of the water. Then by the similar triangles O P R and O W S, we have : of pressure (T) of a rectangular plane surface sustaining the pressure of water, is at a point two-thirds the depth of its immersion. Hence T E = J (y — I). PR or the horizontal thrust of the water on XE is, as we know, expressed by This value of & is, of course, to be measured off from the vertical side. When the water stands at the top of the dam, the value of /, is zero, but when the reservoir is empty, then I, is equal to the entire height of the dam. The simplest way, however, to find the devia tion, is by means of Equation 50, ob serving that the value of £^, when found is to be laid off from the outer or slop ing face of the dam ; and corresponds to the distance FS in Fig. 15. theoretical profile of equal resistance, consists in replacing the outer curved face by a broken one composed of two planes inclined at different angles to the horizon. The principles, however, which justify us in the use of such a modifica tion, may be carried still further, and the inner and vertical face replaced by one almost a fac simile of the outer broken one. Indeed the only essential dif ference between them lies in the degree of slope which we give to their two plane surfaces. On the one side both are sloping ; on the other that portion of the face from the summit of the dam to a point below, (where the pressure on each unit of surface equals the assumed limit of pressure,) the wall is vertical, and from here to the base slope out ward. This latter point moreover, must be directly opposite that point on the outer face at which the two sloping lines of the profile intersect. Of a profile thus constructed, some idea may be had from the sixteenth figure. It does not present any merit either as to beauty, strength, stability or economy of material not possessed by that illustrated in Figs. 12 and 13. As to economy indeed, the amount of material consumed is if any thing greater in former than in the two latter forms of dams, and it may be justly doubted whether the additional stability thus obtained, is a fair recom pense for the additional outlay for material and for cutting facing stones for a third sloping face. As to the mathematical calculations of such a profile they are rather lengthy than difficult. For the upper portion A B C D, Fig. 16, we have already discussed the principles at length, and obtained in equations 51 to 55 the necessary formulae. The value of A B or b is of course known, as also that of AD or a' which is assumed, and is not to be greater than A or the greatest height we can with safety give to a wall with vertical faces. That of the lower portion C D E F, may also be conducted on the principles previously laid down, and as it necessi tates several eliminations of somewhat startling length we shall consider it A B merely in outline. Knowing the total height of the dam, and the distance A D, we of course know D G, or the height of that portion of the dam C D E F, whose breadth of base E F, we wish to find. We also know from equations 51 and 54, the breadth D C , and projecting this on the base we at once obtain that portion of it between GandH. What there re mains to be found is G E, and H F. The former of these unknown quantities we will denote by y, and the latter by z ; the breadth E F, of the base by b,' the part G H, which is also equal to C D, by #'; the height D G, of the lower section of the dam by a, and that of the upper section, or A D, by af. Returning now to the equations 15 and 16, which are the general equations of stability for a dam supporting the pressure of a head of water, we find that the three unknown quantities for which we wish to find values in term of the known quantities we possess are it, I, and p. The value of £, or the thickness E F, of the base is, when expressed in terms of the above notation. While P is of course the area of the ir regular polygon A B C F E D multiplied by the weight per unit of volume, plus the vertical component of the weight of the water resting on the sloping face Again, to find the value of u^ the first step is to construct the diagram of forces, as illustrated in the figure, O P representing in direction and intensity the vertical component P, or the weight of the dam and the water, and O F the horizontal component or the outward thrust of the water behind the dam. Then will F T represent u which is clearly equal to HI is to be obtained in precisely the same manner as K C was obtained from Fig. 14, by expressing the relation that the moment of weight P (which includes, it is to be remembered, that of the dam and that of the water pressing on the inclin ed face D E), with respect to the point F is equal to the sum of the moments of the components of this force. Obtaining these moments in the same manner as we obtained those for the equations de duced from Fig. 14, and putting them equal to the expression P X IF, or P x (IH-f^), we have after reduction, the equation In which oc is a short expression for the area of A BCD, and § the distance from C to the point where the perpen dicular of the centre of gravity of A B C D cuts C D, and this replaced in equation 60, gives for the value of u Eq. 61. The quantities P, u and I, being thus obtained in terms of &', y, z, a and a', a substitution in equations 15 and 16, will furnish us with two equations of great length, from which, by the process of elimination, the values of x and y are readily found. To take but one example of this form of profile, let it be required to calculate the dimensions of such a profile for a masonry dam one hundred and seventy feet in height and eighteen feet broad on top, the limit of pressure being taken at 132,000 pounds. For this purpose we have to determine beforehand the height a! of the part A B C D. This, in the present case, is taken at 80 feet, and may in all cases be assumed arbitrarily. Now, since the dam has one vertical face, we have to determine but one quantity v, or the difference between the thickness of the dam at AB and that at CD, and this value of v is readily obtained from equation 51, which, modified to suit the present notation, becomes And replacing the quantities by their values,remembering that A equals 98.4 ft., and 9 (or the ratio in which the mason ry is heavier than water) equals £, the result finally obtained is, 53.52 feet. With this value of b' we return to the equations expressing the values of x and y as deduced from equations 15 and 16, after the substitution of the value of u given in equation 61, and find that the value of bff=x + b' + y is 178.42 feet. Once more, we may carry this princi ple one step further and produce a pro file which is little more than a modifica tion of that given in Fig. 16. If, for instance, while preserving the same height of structure, we divide each of the three sloping faces into two parts, and give to each part thus produced a face inclined to the horizon, we shall then have a profile of such shape as that illustrated in the seventeenth figure. two preceding profiles, and that there fore the principles to be observed in the calculation of its parts are those already discussed. The entire profile may thus be considered as divided into three pieces ; — that from A to D, in which the inner face is vertical throughout, and the outer made up of two inclined faces, constituting a profile exactly similar in design to that of Fig. 12 : that from D to F, and that from F to H, in each of which both the outer and inner faces are sloping. The first part is, therefore, to be calculated in the same manner as we would calculate the thickness of a dam having the profile of Fig. 1 2, and each of the two remaining portions by the equations deduced from Fig. 16. To illustrate this by a case in point, let it be required to find the thickness at various points of a masonry dam, having such a profile as that we are discussing, its thickness across the top being 18 feet, and the total height 170 feet. The first thing that claims attention is the determination of the vertical distances between the points B and C ; C and E ; E and G ; and finally G and I. These may, of course, be chosen at pleasure, just as we may select the number of parts that each face is to be composed of, and as in the present case the dam is 170 feet high, and the outer face divided into four parts, we will for convenience divide the dam first into two equal parts, then divide the lower of these again into two equal parts, and the upper also into two, but two unequal parts. The verti cal distances between the sections will then be, beginning at the bottom and going up G I = 42,5 feet; E G = 42.5 feet ; C E = 45 ; and B C = 40 feet. Had the dam, however, been one hundred and fifty, or one hundred and eighty feel high, or indeed any other number, then the best arrangement would again have been, to make the second vertical dis tance — that from C to D — longer than the remaining three, so that, if the dam was one hundred and fifty feet high, the best arrangement would be BC — 30 ; CE = 60; and E G and GI each thirty feet ; if the height had been one hund red and eighty feet, then B C = 40; CE = 50 ; and the others each forty-five feet. Although this arrangement may seem to be somewhat arbitrary, it is in reality based upon fixed principles,which clearly show that where such a number of divisions and such a profile as that used in the present instance are employ ed, the second part should be decidedly longer than either of the other three. Those portions, moreover, which are bounded on both sides by sloping faces are in almost all cases made of equal depth, nor does there seem to be any reason whatever for not adhering to this method. With these distances thus determined, we return to equations 51 and 54, and from the first of these find the value of v, as was done for equation 63, and sub stituting for ar the value 40, and for b the quantity 18 feet, we have And, consequently, #' = £ + ^ = 21.37 feet. To find the value of b', however, it is necessary to use equations 51 and 54, from which by the common method of elimination we may find an expression from which by the substitution of the proper values we obtained for a final value of //, or the thickness of the base of this section, £"=54.64 feet, or ^ = 33.27 feet. The next step is to find the values of x and ?/for the third section. As this, and also the last section have both faces slop ing, by substituting the value of u given in equation 61, in equations 15 and 16, and reducing and then eliminating, we obtain two expressions for x and y, from which we derive the thickness GF = 100.36, and by a similar process find that for I H to be 152.22 feet. It is thus apparent, that as there is al most no limit to the number of sections into which a dam may, on this principle, be divided, there are a great number of different forms of profile, each of which, satisfy the conditions of stability, but vary somewhat as to economy. Theo retically the dam whose outer face con sists of the greatest number of these sloping faces is the most economical, because in that case its face approaches nearest to the logarithmic curve which bounds the theoretical profile of equal resistance, and it therefore contains very little more masonry than is absolutely necessary to insure safety. In practice, however, such a dam would, in all proba bility prove much more costly than one consisting of a less number of section, though containing more masonry, be cause the angle of inclination of the different sections of the outer face changing so frequently would greatly increase the cost of cutting the facing stone. To avoid the mechanical difficul ties also likely to arise in such cases, it is sometimes well to depart altogether from this style of profile, and instead of slop ing the outer and inner faces, cut them into notches or steps. THE STEPPED PEOFILE. The stepped profile has been reserved to the last for consideration, because, while it is a natural outgrowth of the preceding modifications, it possesses many merits whose importance cannot be fully appreciated till a comparison is instituted between it and the forms just treated of. In point of simplicity of construction for instance, it would be difficult to find any design of profile that can surpass it. Wherever the faces of the dam are curved as in Fig. 9, or made up of a series of sloping surfaces of various inclination as in Figs. 12, 16 and 17, the dimensions of every facing stone that is set have to be most care fully determined beforehand by the rules of stereography, and this, when the dam is an high one and the number of stones consequently large, is of itself a work of no small difficulty. In the stepped dam however, all this is done away with, as every facing stone, (unless the dam is curved) possesses only a ver tical or, if it happens to form the edge of the step, a vertical and horizontal face, and thus requires no pattern for the stone cutter. A further advantage to be derived from it, is, that it enables us to approach much nearer the curved form of profile than we can in any other profile type. Indeed, when well designed it is in reality nothing but the logarith mic curved profile cut into steps or notches, so that should we draw a con- tinuous line through the upper edges of all the steps, or through the lower edges of their vertical faces, this line would form a logarithmic curve. Here, as in the calculation of the previous profiles, it is quite allowable to assume arbitrarily either the breadth or height of the step and from this one de termine the other. Yet it is by far the best plan to assume the vertical height of the step and calculate the breadth. For, it must be apparent, that by this method of procedure, the quantity we calculate is really the abscissa of the curve, which we lay off at regular inter vals perpendicularly to the vertical axis of the dam, and in this way we are enabled to preserve very closely the logarithmic profile. The general appear ance of the dam is, moreover, much more pleasing when this arrangement is ob served than when we assume a constant breadth and calculate the depth, because the breadth of the steps near the summit of the dam is then very narrow and in creases gradually as they approach the bottom, and the departure from the curve is thus scarcely perceptible ; but when the breadth is everywhere the same and the depth varies, the whole face of the dam has an extremely broken appearance, which is anything but agreeable. In this profile, as in all the others, the inner face is made vertical for as great a distance as the limit of pressure will al low, and from that point down it is stepped. The outer face is likewise made vertical for a distance which de pends in all cases on the thickness across the top, being as a general thing very nearly twice that dimension. In the de termination of the following formulae, the depth of the step has been assumed as the same throughout the entire dam, and the breadth has been taken as the unknown quantity. Fig. 18 then rep resents a portion of the profile of a dam bound by a curved or sloping face, which we wish to change into a stepped profile. ABDC represents this section, and if H F be taken as the vertical height of the step, then will C H F represent the element with which we are especially concerned, and its base CH the quantity we are in search of, — the breadth of the step. The height B D of the section we will denote by h\ and the density of the •masonry by d r; and the greatest thick ness FT or HD of the known element ABTDHF by t\ from which three quantities we may obtain an expression for the weight P, of this element, which must of course be accurately known, in- as much as the object of making the step at this point being to lessen the amount of vertical pressure on each superficial unit, the breadth of the step will depend very largely on the weight of that por tion of the dam which is above it. The weight which is plainly equal to a is the height of the step F H, and b the breadth C H. The point of applica tion of the thrust of the water is T situated at two-thirds the depth of im mersion. T' and T2 are the horizontal and vertical components respectively. Then will P represent the direction of the re sultants of P and T2; V V the resultant ment C H F, while the general resultant of all the forces is R. Now, in this case, as in the previous ones, the whole solu tion of the problem depends on finding the value of C R, or the distance from the outer edge C to the point where the resultant cuts the base, and this we will express as heretofore by the letter u. Then from the figure M denoting the moment of P' with re spect of H. As to C H, its value is &, the quantity we are in search of. Re placing these quantities in the equation expressive of the value of u, we have Having thus obtained an equation for the value of u, the next step is to find by means of it an expression for b the breadth of the step. For this purpose draw from R, the point at which the general resultant of all the acting forces outs the base, a perpendicular R N" to the resultant, and from N a perpendicular to the base C D, thus forming a triangle R N O. Then, since the two triangles R Y Y and R 1ST O have their bases on the same right line C D, and the side YR of the one perpendicular to the side NR of the other, and the sides YY and NO parallel, the angles at Y and N are equal and the triangles are similar. But by the relation existing between the sides of such similar triangles, we have the pro portion in which /is the distance R O. But we have another pair of similar triangles which gives yet another value for N O, which must be deduced and made equal to that just found. These triangles are CO 1ST and C H F, and the proportion derived from the relation of their sides is, Substituting for u its equivalent value as given in equation 65, and dividing both members of the resulting equation by the common factor 2 P + d' b a, there re sults which is the expression for the breadth of the step. As to the meaning of the letters it may once more be stated, that P is the weight in pounds of A B D H F, and d' the density of the masonry. The vertical height (F H), which we de termine to give the step, is expressed by a, that of the entire dam from the top to the base of the step by A, and the moment of the weight P, with respect to the vertical F H forming the rise of the step by M ; while by A, we mean, as in all previous formulae, the greatest height to which we can raise a vertical wall without the pressure per unit of surface on the base, becoming larger than the limit R' of pressure ; and by $, the ex pression — „ or the ratio in which the density of the masonry exceeds that of water. This value of 0, is safely taken at £. As to the height to be given to the step, this is of course to be assumed at pleasure, but the most pleasing effect is produced when it is taken at six or seven feet, for then, even in dams of one hundred and sixty feet in height, con- structed of the heaviest stone, the breadth of the step will rarely at any point be materially greater than the rise. The point on the outer face at which the first step should begin, or in other words the distance A B, in Fig. 19, is deterA mined, as in the other instances, by the relation which the breadth on top bears to the height. If the thickness t, across the summit be assumed then When that point on the inner face is reached, at which it becomes necessary to begin stepping, the breadths l> and &', of the outer and inner steps respectively, may be had by substituting the value of u, in equations 15 and 16, and from the two resulting equations, finding by elimination two expressions for b and V . This calculation may, however, be avoid ed, and considerable expense for cutting facing stone saved, by making the inner face vertical from top to bottom. Indeed the matter of expense for dressing stone is, perhaps, the most serious objection to dress both faces of the step. As regards the use of the formulae for this form of profile, it is to be borne in mind, that P includes the weight of the water as well as the weight of the masonry, so that in determining the breadth of the fourth step, the weight of the three columns of water resting, one on the first, one on the second and one on the third step, is to be added to the pressure of the masonry. The press ure of the water is readily obtained from equation 1. The principles that have now been es tablished in connection writh the four types of profiles treated of, are all that are required to calculate the parts of any profile that is ever likely to arise in practice. They have, moreover, been determined without regard to the length of the dam, so that the structure will be one of equal resistance, and withstand the thrust of the water solely by its own weight. There is, therefore, no valid reason why a dam constructed with a profile of equal resistance should be curved into the form of an arch, and this holds good, whether it be high or low, whether it obstructs a broad valley or a narrow one. The only thing that can be accomplished by curving a dam, is to relieve it from severe strains, by transmitting as large a part of the thrust to the sides of the valley, but where the profile is such that the dam is every where equally strong, and equally capa ble of resisting by its own weight the severest strain it is ever subjected to, there is surely nothing to be gained by increasing its length in order to transmit this thrust laterally to the sides of the valley. It is true that in deep and nar row valleys, some saving of material may be affected by curving the dam, which being thus relieved from a goodly por tion of the thrust, may be diminished in thickness. But in long dams, it is an open question whether the saving thus affected is not more than balanced by the increased length. One other matter which deserves the most careful attention, and which in deed unless it is carefully attended to will render the very best profile of no account, it is the binding of the stones, and the character of the inner filling. As to the bond, it is undoubtedly the wisest plan if the dam is to resist a great pressure, to avoid laying the stones in horizontal courses wherever such a thing is practicable, and to place binders in every possible direction. For assuredly, if it is necessary for the stability of all walls bearing a vertical load, that there should be no continuous joints in the direction of the pressure, it is just as important that a dam should have no continuous horizontal joints, because in the case of such structures almost every ounce of thrust they have to resist is horizontal, and thus exactly coincides with the joints. If the dam is curved, then this matter of broken horizontal joints is not of such vital importance, because no layer can then slide until some one of the stones has been crushed, yet even here it cannot be too rigidly adhered to. By a strange inconsistency on the part of engineers, we often see this matter both regarded and disre garded in the same dam. Many struc tures of this class could be named, in which the rock foundation is stepped with the utmost care to preclude any possibility of sliding where sliding is of all places the least likely to occur, while the courses from the foundation to the top are laid with the most perfect kind of horizontal joints. The filling again must not be of too different a character from the facing. Where masonry consists of dressed stone and rubble work, the amount of settling is so different in each case that nothing like a bond can be preserved. The affect of such settling, we constantly see illustrated in the most striking way in canal locks. As is well known these are generally cut stone facings with rubble backing, but the latter settling more than the former become detached from the facings, when the water penetrating between the two kinds of masonry, the cut stone facings fall with the first frost. A good filling is that made of large rough blocks of stone, set at regular in tervals apart, (the distance increasing as the top is approached) and the spaces between and over them filled in with beton of the first quality, a method, we believe, lately adopted in the construction of one of the Croton dams in this state. But perhaps a yet better one is to replace the beton by the French mixture known as beton coigmt. Both of these fillings, however, are good, as when well rammed, they form a close connection with the facing stones, and do away entirely with joints of any kind. NEW YORK. FRANCIS. Lowell Hydraulic Experiments, being a selection from Experiments on Hydraulic Motors, on the Flow of Water over Weirs, in Open Canals of Uniform Rectangular Section, and through submerg ed Orifices and diverging Tubes. Made at Lowell, Massachusetts. By James B. Francis, C. E. 2(1 edition, revised and enlarged, with many new experi ments, and illustrated with twenty-three copperplate engravings, i vol. 4to, cloth $15 oo ROEBLING (J. A.) Long and Short Span Railway Bridges. By John A. Roebling, C. E. Illustrated with large copperplate engravings of plans and views. Imperial folio, cloth 25 oo CLARKE (T. C.) Description of the Iron Railway Bridge over the Mississippi River, at Quincy, Illi nois. Thomas Curtis Clarke, Chief Engineer. Illustrated with 21 lithographed plans, i vol. 410, cloth 7 50 TUNNER (P.) A Treatise on Roll-Turning for the Manufacture of Iron. By Peter Tunner. Trans lated and adapted by John B. Pearse, of the Penn- ISHERWOOD (B. F.) Engineering Precedents for Steam Machinery. Arranged in the most practical and useful manner for Engineers. By B. F. Isher\yood, Civil Engineer, U. S. Navy. With Illustra tions. Two volumes in one. 8vo, cloth $2 50 GILLMORE (Gen. Q. A,) Practical Treatise on the Construction or Roads, Streets, and Pavements. By Q. A. Gillmore, Lt.-Col. U. ^ Corps of Engineers, Brevet Major-Gen. U. S- Army, with 70 illustra tions. i2mo, cloth 2 oo Francis Campin. 8vo, with plates, cloth 2 oo COLLINS. The Private Book of Useful Alloys and Memoranda for Goldsmiths, Jewellers, &c- By James E. Collins. i8mo, cloth 75 CIPHER AND SECRET LETTER AND TELE GRAPHIC CODE, with Hogg's Improvements. The most perfect secret code ever invented or dis covered, impossible to read without the key. By C. S. Larrabee. i8mo, cloth i oo Colburn, C. E. i vol 12010, boards 60 CRAIG (B. F.) Weights and Measures. An account of the Decimal System, with Tables of Conversion for Commercial and Scientific Uses. By B. F. Craig, M.D. i vol. square 32mo, limp cloth 5° NUGENT. Treatise on Optics; or, Light and Sight, theoretically and practically treated ; with the appli cation to Fine Art and Industrial Pursuits. By E. Nugent. With one hundred and three illustrations. i2mo, cloth 2 oo HOWARD. Earthwork Mensuration on the Basis of the Prismoidal Formulae. Containing simple and la bor-saving method of obtaining Prismoidal contents directly from End Areas. Illustrated by Examples, and accompanied by Plain Rules for Practical Uses. By Conway R. Howard, C. E., Richmond, Va. Il lustrated, 8 vo, cloth i 50 GRUNER. The Manufacture of Steel. By M. L. Gruner. Translated from the French, by Lenox Smith, with an appendix on the Bessamer process in the United States, by the translator. Illustrated by Lithographed drawings and wood cuts. 8vo, cloth.. 3 50 AUCHINCLOSS. Link and Valve Motions Simplified. Illustrated with 37 wood-cuts, and 21 lithographic plates, together with a Travel Scale, and numerous useful Tables. By W. S. Auchincloss. 8vo, cloth. . 3 oo VAN BUREN. Investigations of Formulas, for the strength of the Iron parts of Steam Machinery. By J. D. Van Buren, Jr., C. E. Illustrated, 8vo, cloth. 2 oo Gearing. Illustrated, 8vo, cloth 2 oo GILLMOKE. Coignet Beton and other Artificial Stone. By Q. A. Gillmore, Major U. S. Corps Engineers. 9 plates, views, &c. 8vo, cloth 250 cloth 2 oc BOW. A Treatisa on Bracing, with its application to Bridges and other Structures of Wood or Iron. By Robert Henry Bow, C. E. 156 illustrations, 8vo, doth j 50 BARBA (J.) The Use of Steel for Constructive Pur poses; Method of Working, Applying, and Testing Plates and Brass. With a Preface by A. L. Holley, C. E. i-zmo, cloth i 50 DIEDRICH. The Theory of Strains, a Compendium ' for the calculation and construction of Bridges, Roofs, and Cranes, with the application of Trigonometrical Notes, containing the most comprehensive informa tion in regard to the Resulting strains for a perman ent Load, as also for a combined (Permanent and Rolling) Load. In two sections, adadted to the re quirements of the present time. By John Diedrich, C. E. Illustrated by numerous plates and diagrams. Svo, cloth t 5 QQ WILLIAMSON (R. S.) On the use of the Barometer on Surveys and Reconnoissances. Part I. Meteorology in its Connection with Hypsometry. Part II. Baro metric Hypsometry. By R. S. Wiliamson, Bvt Lieut. -Col. U. S. A., Major Corps of Engineers. With Illustrative Tables and Engravings. Paper No. 15, Professional Papers, Corps of Engineers. i vol. 4to, cloth... > 15 oo POOK (S. M.) Method of Comparing the Lines and Draughting Vessels Propelled by Sail or Steam. Including a chapter on Laying off on the MouldLoft Floor. By Samuel M. Pook, Naval Construc tor, i vol. Svo, with illustrations, cloth 5 oo ALEXANDER (J. H.) Universal Dictionary of Weights and Measures, Ancient and Modern, re duced to the standards of the United States of Ame rica. By J. H. Alexander. New edition, enlarged, i vol. Svo, cloth 3 50 WANKLYN. A Practical Treatise on the Examination of Milk, and its Derivatives, Cream, Butter and Cheese. By J. Alfred Wanklyn, M. R. C. 8., izmo. cloth i oo RICHARDS' INDICATOR. A Treatise on the Rich ?rds Steam Engine Indicator, with an Appendix by <?. W. Bacon, M. E. i8mo, flexible, cloth x oo PORTER (C. T.) A Treatise on the Richards Steam Engine Indicator, and the Development and Applica tion of Force in the Steam Engine. By Charles T. Porter. Third edition, revised and enlarged. Svo, D. VAN NOSTKAND S PUBLICATIONS. POPE. Modern Practice of the Electric Telegraph. A Hand Book for Electricians and operators. By Frank L. Pope. Ninth edition, revised and enlarged, and fully illustrated. 8vo, cloth $2 oo " There is no other work of this kind in tha English language that con tains in so small a compass so much practical information in the appli cation of galvanic electricity to telegraphy. It should be in the hands of everyone interested in telegraphy, or the use of Batteries for other pur poses.'' EASSIE (P. B.) Wood and its Uses. A Hand -Book for the use of Contractors, Builders, Architects, En gineers, and Timber Merchants. By P. B. Eassie. Upwards of 250 illustrations. 8vo, cloth i 50 SABINE. History and Progress of the Electric Tele graph, with descriptions of some of the apparatus. By Robert Sabme, C. E, Second edition, with ad ditions, i2mo, cloth i 35 BLAKE. Ceramic Art. A Report on Pottery, Porce lain, Tiles, Terra Cotta and Brick. By W. P. Blake, U. S. Commissioner, Vienna Exhibition, 1873. 8vo, cloth 2 oo BE NET. Electro-Ballistic Machines, and the Schultz Chronoscope. By Lieut. -Col. S. V. Benet, Captain of Ordnance, U. S. Army- Illustrated, second edi tion, 4to, cloth o 3 oo MICHAELIS. The Le Boulenge Chronograph, with three Lithograph folding plates of illustrations. ByBrevet Captain O. E. Michaelis, First Lieutenant Ordnance Corps, U. S. Army, 410, cloth „. . . . 3 oo ENGINEERING FACTS AND FIGURES An Annual Register of Progress in Mechanical Engineer ing and Construction, for the years 1863, 64, 65, 66 67, 68. Fully illustrated, 6 vols. i8mo, cloth, $2.50 per vol., each volume sold separately HAMILTON. Useful Information for Railway Men. Compiled by W. G. Hamilton, Engineer. Sixth edi tion, revised and enlarged, 562 pages Pocket form. Morocco, gilt 2 oo STUART (B.) How to Become a Successful Engineer. Being Hints to Youths intending to adopt the Pro fession. Sixth edition. i2mo, boards 50 ELIOT AND STORER. A compendious Manual of Qualitative Chemical Analysis. By Charles W. tiiot and Frank H. Storer. Revised with the Co operation of the authors. By William R. Nichols, Professor of Chemistry in the Massachusetts insti tute of Technology Illustrated, i2mo, cloth $i 50 RAMMELSBERG. Guide to a course of Quantitative Chemical Analysis, especially of Minerals and Fur nace Products. Illustrated by Examples By C. F. Ramn?elsberg. Translated by J. Tovvler, M. D. 8 vo, cloth 2 23 DOUGLASS and PRESCOTT. Qualitative Chemical Analysis. A Guide in the Practical Study of Chem istry, and in the Work of Analysis. By S. H. Doug lass and A. B. J'rescott, of the University of Michi gan. New edition. 8vo. In pre&8. WATT'S Dictionary of Chemistry. New and Revised edition complete in 6 vols 8vo cloth, $62.00 Sup plementary volume sold separately. Price, cloth. . . 9 oo illustrated. i2mo, cloth 200 SILVERSMITH. A Practical Hand-Book for Miners, Metallurgists, and Assayers, comprising the most re cent improvements in the disintegration amalgama tion, smelting, and parting of the > recious ores, with a comprehensive Digest of the Mining Laws Greatly augmented, revised and corrected. By Juiius Sliversmith Fourth edition. Profusely illustrated. i2mo, cloth 3 oo THE USEFUL METALS AND THEIR ALLOYS, including Mining Ventilation, Mining Jurisprudence, and Metallurgic Chemistry employed in the conver sion of Iron, Copper, Tin, Zinc, Antimony and Lead ores, with their applications to the Industrial Arts. By Scoffren, Truan, Clay, Oxland, Fairbairn, and JOYNSON. The Metals used in construction, lion, Steel, Bessemer Metal, etc., etc. By F. H. Joynson. Illustrated, 1 2mo, cloth $o 75 VON COTTA. Treatise on Ore Deposits. By Bernhard Von Cotta, Professor of Geology in the Royal School of Mines, Freidberg, Saxony. Translated from the second German edition, by Frederick Prime, Jr., Mining Engineer, and revised by the au thor, with numerous illustrations. 8vo, cloth 4 oc GREENE. Graphical Method for the Analysis of Bridge Trusses, extended to continuous Girders and Dra1 Spans. By C. F. Greene, A. M., Prof, of Civil Eng: folding plates, 8vo, cloth BELL. Chemical Phenomena of Iron Smelting. An experimental and practical examination ot the cir cumstances which determine the capacity of the Blast Furnace, The Temperature of the air, aiid the proper condition of the Materials to be operated upon. By 1. Lowthian Bell. 8vo, cloth ........... 600 ROGERS. The Geology of Pennsylvania. A Govern ment survey, with a general view of the Geology of the United States, Essays on the Coal Formation and its Fossils, ai;d a description of the Coal Fields of North America and Great Britain. By Henr\ Dar win Rogers, late State Geologist of Pennsylvania, Splendidly illustrated with Plates and Engravings in the text. 3 vols , 410, cloth with 1 ortfolio of Maps. 30 oo BUKGH. Modern Marine Engineering, applied to Paddl2 and Screw Propulsion Consisting of 36 colored plates, 259 Practical V\ cod tut Illustrations, and 403 pa^es oi descriptive matter, the whole being an exposition of the present practice of James Watt & Co.. J & G Rennie, R. Napier & Sons, and other celebrated firms, by N. P. Burgh, Engi neer, thick 4to, vol., cloth, $25.00; halfmor ....... 30 oo BOURNE. Treatise on the Steam Engine in its various applications to Mines, Mills, Steam Navigation, Railways, and Agriculture, with the theoretical in vestigations respecting the Motive Power of Heat, and the proper proportions of steam engines. Elabo rate tables of the right dimensions of every part, and Practical Instructions for the manufacture and man agement of every species of Engine in actual use. By John Bourne, being the ninth edition of " A Treatise on the Steam Engine," by the " Artizan Clubo" Illustrated by 38 plates and 546 wood cuts. 4to, cloth ,,..$15 oc STUART. The Naval Dry Docks of the United Spates. By Charles B. Stuart late Engineer-in-Chief of the U. S. Navy. Illustrated with 24 engravings with in Coal Mines. i8mo, boards 50 FOSTER. Submarine Blasting in Boston Harbor, Massachusetts. Removal of Tower and Corwin Rocks. By J. G. Foster, Lieut -Col. of Engineers, U. S. Army. Illustrated with seven plates, 4to, cloth 3 50 BARNES Submarine Warfare, offensive and defensive, including a discussion of the offensive Torpedo Sys tem, its effects upon Iron Clad Ship Systems and in fluence upon future naval wars. By Lieut. -Com mander J. S. Barnes, U. S. N., with twenty litho graphic plates and many wood cuts. 8vo, cloth.. . . 5 oc HOLLEY. A Treatise on Ordnance and Armor, em bracing descriptions, discussions, and professional opinions concerning the materials, fabrication, re quirements, capabilities, and endurance of European and American Guns, for Kaval, Sea Coast, and Iron Clad Warfare, and their Rifling, Projectiles, and Br eech- Loading ; also, results of experiments against armor, from official records, with an appendix refer ring to Gun Cotton, Hooped Guns, etc., etc. By Alexander L. Holley, B. P., 948 pages, 493 engrav ings, and 147 Tables of Results, etc., 8vo, half roan. 10 oo AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. and Use. By Arthur V. Abbott. RECENT PROGRESS IN DYNAMO- ELECTRIC MA CHINES. Being a Supplement to Dynamo-Elec tric Machinery. By Prof. Silvanus P. Thompson. - • — '-1-L-i.E cORTw . . _ ..TCN 0^ V* T:> .x iSICAL FORO'E; I By Prof. Gteo* OT I.D., of Yale College. 86 p^. Paper Covci TV.— ON THE F~ XX HESIS OF F/{ Physical and Af#U,j y$i\al. By Proi' COPE, 12mo., 72 pp. >apsr Covers, pr thoda and Tendvncif.s of Physical /> Baz* and D> . 8. C<r>, the tictenUf nation. By Prof. JO^N TYNDALL, F.K. pp. Paper Covers. Price 25 cents. Flex. ( TO MAN. By ALFRED RITSSELT, WAI_ pamphlet treats (1; of the Development Haces under the^aw of selection ; (2) thelii ural Selection a? applied" to man. 54 pp. Pi	25,203	common-pile/pre_1929_books_filtered	highmasonrydamn00mcmarich	public_library	public_library_1929_dolma-0013.json.gz:584	https://archive.org/download/highmasonrydamn00mcmarich/highmasonrydamn00mcmarich_djvu.txt
jT-B1iByDrTSg_w-	Introduction to the Sustainable Development Goals (SDGs)	Week 11 Monitoring, Evaluation, Reporting In the previous lecture we learned about achieving the SDGs through planning and implementation at all levels of government with collaboration from civil societies, business, and partnerships. This week we will be looking at how the indicators and their targets form the basis of monitoring SDG implementation. We will look at how countries are doing this including evaluation indices and progress reporting. You will recall the sustainable development goals include a list of 169 targets. In 2017, the UN General Assembly also approved the global indicator framework, a list of 232 indicators which are divided across the 17 goals and relate to their corresponding targets. Working together, the indicators and their targets form the foundation for monitoring the success of the SDGs. The indicators are tools to help governments and institutions create implementation and monitoring strategies. They are appropriate for the local, regional, and national level to help establish priorities for governments and others working towards the SDGs. They function as a report card to evaluate programmes and policy progress and success. They are essential for showing Member State progress on achieving 2030 Agenda commitments, as individual countries are encouraged to adapt the global targets and indicators to national conditions, reflecting the priorities in their National Development Plans. Let’s look at an example of how targets and indicators measure the success of an SDG Remember – targets are something to be achieved that is measurable, while indicators show the measurement by which those targets can be judged or assessed. We will use SDG #1 – End Poverty in all its forms everywhere, as our example. SDG # 1 is supported by 7 targets and 12 indicators. Target 1: By 2030, eradicate extreme poverty for all people everywhere, currently measured as people living on less than US$1.90 a day. Indicator 1: Proportion of population below the international poverty line, by sex, age, employment status and geographical location (urban/rural). The first target is to eradicate extreme poverty for all people everywhere by 2030. The indicator for this target is to assess the proportion of the population below the international poverty line (less than US$1.90 a day), by sex, age, employment status and geographical location (urban/rural). Using this example, we can track the percentage of the global population living below the international poverty line. This data can be tracked over time and allows progress towards this goal to be reportable.[1] In the example above, the target and corresponding indicator are for a global measurement, using the international poverty line. We mentioned SDG #1 has 7 targets. Target #2 measures poverty at the national level, see below. SDG #1 Target 2: - - by 2030, reduce at least by half the proportion of men, women and children of all ages living in poverty in all its dimensions according to national definitions. SDG #1 Indicator 2: - - Proportion of population living below the national poverty line, by sex and age - Proportion of men, women and children of all ages living in poverty in all its dimensions according to national definitions SDG target 2 and indicator 2 allows for differences between countries. Although target 1 refers to extreme poverty, currently measured as the international poverty line at US $1.90 a day, target 2 focuses on “national definitions” and encourages all countries to half the proportion of people affected. As you will recall from the week three lecture, Canada’s official poverty line is defined based on the Market Basket Measure (MBM), which is the number of people who do not have enough income to purchase a specific basket of goods and services in their community. Measuring progress There are many challenges regarding measuring SDG progress, with data collection proving to be a difficult task. This is especially true for measuring change at the local community level, nationally, and globally. For some indicators, data is relatively easy to acquire because of well-established methodologies and already existing collection practices. For other indicators, there are no clear established methodologies, or the data is not widely collected internationally. To tackle this issue an expert group created the global indicator framework, where the SDG indicators were divided into three categories: Tier 1: Indicators with easy to find data and clear and established methodologies Tier 2: Indicators with clear and established methodologies but the data might be difficult to find as it is not regularly produced by all countries Tier 3: Internationally established methodologies or standards are not yet available for the indicator, but the methodology/standards are being (or will be) developed or tested This was an important step for generating internationally-comparable data. National statistical collectors (i.e. Statistics Canada) have the central responsibility of compiling credible data. They then make this data available for regional, national, and global evaluation and reporting. Despite national and international cooperation, there remain challenges for SDG monitoring and evaluation. There are indicators that lack agreed-upon methodologies or available official data. Some countries national statistical offices lack the capacity to produce relevant data. There are issues related to the use of unofficial sources of data, such as data produced by private companies, which provide opportunities for measuring crucial SDG indicators, but lack a role in the formal reporting system. To fully understand progress on the SDGs, policy-makers and stakeholders at all levels need access to data that is reliable, relevant, and user-friendly to make meaningful, and measurable progress on the SDGs. Video In this 10-minute video made available from the SDG Academy, Dr. Guido Schmidt-Traub (Executive Director of the Sustainable Development Solutions Network) introduces the SDG Index and Dashboards, reviewing its history and development since 2015, and the unique role it plays in measuring progress toward achieving the SDGs. SDG Index and Dashboard for Canada Exercise Discussion Question - Share your reflections from above with another learner. Compare and contrast your discoveries. Comprehension Questions Recommended Reading - The Sustainable Development Report is a global assessment of each countries progress towards achieving the SDGs. It is a complement to the official SDG indicators and the voluntary national reviews. - United Nations. (2021). The Sustainable Development Goal Report, 2020. ↵ - United Nations. (2021). The 2021 Sustainable Development Goal Report: The Decade of Action for the Sustainable Development Goals. ↵	1,346	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/sdgintro/chapter/monitoring-evaluation-reporting/	pressbooks	pressbooks-0000.json.gz:18165	https://ecampusontario.pressbooks.pub/sdgintro/chapter/monitoring-evaluation-reporting/
zXw_nd4utywgd47l	1.0: Prelude to Exploring College	How do you feel about your ability to meet the expectations of college? These questions will help you determine how the chapter concepts relate to you right now. As we are introduced to new concepts and practices, it can be informative to reflect on how your understanding changes over time. We’ll revisit these questions at the end of the chapter to see whether your feelings have changed. Take this quick survey to figure it out, ranking questions on a scale of 1 – 4, 1 meaning “least like me” and 4 meaning “most like me.” Don’t be concerned with the results. If your score is low, you will most likely gain even more from this book. I am fully aware of the expectations of college and how to meet them. I know why I am in college and have clear goals that I want to achieve. Most of the time, I take responsibility for my learning new and challenging concepts. I feel comfortable working with faculty, advisors, and classmates to accomplish my goals. “As students transitioning to college, responsibility is an inherent component of self-advocacy. As someone accepted on full funding to a 4-year university, but whose life’s circumstances disallowed attending college until years later, I used to dream of a stress-free college life. The reality is, college can be a meaningful place, but it can also be challenging and unpredictable. The key is to be your own best advocate , because no one else is obliged to advocate on your behalf. “When I began my community college studies, I knew what I wanted to do. Cybersecurity was my passion, but I had no understanding of how credits transfer over to a 4-year university. This came to haunt me later, after I navigated the complex processes of transferring between two different colleges. Not everyone involved volunteers information. It is up to you, the student, to be the squeaky wheel so you can get the grease. Visit office hours, make appointments, and schedule meetings with stakeholders so that you are not just buried under the sheaf of papers on someone’s desk.” —Mohammed Khalid , University of Maryland About this Chapter In this chapter, you will learn about what you can do to get ready for college. By the time you complete this chapter, you should be able to do the following: Recognize the purpose and value of college. Describe the transitional experience of the first year of college. Discuss how to handle college culture and expectations. Identify resources in this text and on your campus for supporting your college success. Reginald Madison Reginald has, after much thought and with a high level of family support, decided to enroll in college. It has been a dream in the making, as he was unable to attend immediately after high school graduation. Because it has been almost a decade since he sat in a classroom, he is worried about how he will fit in as an adult learner returning to college. Will his classmates think he is too old? Will his professors think he is not ready for the challenges of college work? Will his family get tired of his long nights at the library and his new priorities? There is so much Reginald is unsure of, yet he knows it’s a step in the right direction. It has been only three months since Madison graduated from high school. She graduated in the top 10 percent of her class, and she earned college credit while in high school. She feels academically prepared, and she has a good sense of what degree she wants to earn. Since Madison was 5 years old, she’s wanted to be an engineer because she loved building things in the backyard with her father’s tools. He always encouraged her to follow her dreams, and her whole family has been supportive of her hobbies and interests. However, Madison is concerned that her choice of major will keep her from dance, creative writing, and other passions. Furthermore, Madison is heading to a distant college with no other people she knows. Will she be able to find new friends quickly? Will her engineering classes crush her or motivate her to complete college? Will she be able to explore other interests? Madison has a lot on her mind, but she aims to face these challenges head-on. While Reginald and Madison have had different experiences before and certainly have different motivations for enrolling in college, they have quite a bit in common. They are both committed to this new chapter in their lives, and they are both connected to their families in ways that can influence their commitment to this pursuit. What they don’t know just yet—because they haven’t started their classes—is that they will have even more in common as they move through each term, focus on a major, and plan for life after graduation. And they have a lot in common with you as well because you are in a similar position—starting the next chapter of the rest of your life. In this chapter, you will first learn more about identifying the reason you are in college. This is an important first step because knowing your why will keep you motivated. Next, the chapter will cover the transitions that you may experience as a new college student. Then, the chapter will focus on how you can acclimate to the culture and meeting the expectations—all of which will make the transition to a full-fledged college student easier. Finally, the chapter will provide you with strategies for overcoming the challenges that you may face by providing information about how to find and access resources.	1,220	common-pile/libretexts_filtered	https://socialsci.libretexts.org/Bookshelves/Counseling_and_Guidance/College_Success_(OpenStax)/01%3A_Exploring_College/1.00%3A_Prelude_to_Exploring_College	libretexts	libretexts-0000.json.gz:27995	https://socialsci.libretexts.org/Bookshelves/Counseling_and_Guidance/College_Success_(OpenStax)/01%3A_Exploring_College/1.00%3A_Prelude_to_Exploring_College
p6UmFH0Y4EhPaKBx	Advanced Procedural Skills	Venipuncture - To ensure the quality of test results, it is essential that the correct type of specimen is collected from the correct patient and labelled properly. The blood specimen must be handled correctly and delivered in a timely manner to the appropriate lab area for testing. - Providers must be aware of sites in which venipuncture is not recommended (i.e., scars, tattoos, mastectomy, etc.) and chose alternatives appropriately. - The median cephalic vein is located in the antecubital fossa and is the most desirable site for venipuncture. - The tourniquet should be removed within one minute to avoid hemoconcentration (an increase in cellular elements).	136	common-pile/pressbooks_filtered	https://pressbooks.pub/pcnp/chapter/key-takeaways-18/	pressbooks	pressbooks-0000.json.gz:17802	https://pressbooks.pub/pcnp/chapter/key-takeaways-18/
1V200VoF9R57RTVF	2.7A: Structure, Type, and Location of Cartilage	2.7A: Structure, Type, and Location of Cartilage - - Last updated - Save as PDF Cartilage is an avascular, flexible connective tissue located throughout the body that provides support and cushioning for adjacent tissues. LEARNING OBJECTIVE Differentiate among the types of cartilage Key Takeaways Key Points - Cartilage is a flexible connective tissue that differs from bone in several ways; it is avascular and its microarchitecture is less organized than bone. - Cartilage is not innervated and therefore relies on diffusion to obtain nutrients. This causes it to heal very slowly. - The main cell types in cartilage are chondrocytes, the ground substance is chondroitin sulfate, and the fibrous sheath is called perichondrium. - There are three types of cartilage: hyaline, fibrous, and elastic cartilage. - Hyaline cartilage is the most widespread type and resembles glass. In the embryo, bone begins as hyaline cartilage and later ossifies. - Fibrous cartilage has many collagen fibers and is found in the intervertebral discs and pubic symphysis. - Elastic cartilage is springy, yellow, and elastic and is found in the internal support of the external ear and in the epiglottis. Key Terms chondroitin sulfate : An important structural component of cartilage that provides much of its resistance to compression. connective tissue : A type of tissue found in animals whose main function is to bind other tissue systems (such as muscle to skin) or organs. It consists of the following three elements: cells, fibers, and a ground substance (or extracellular matrix). hyaline cartilage : A type of cartilage found on many joint surfaces; it contains no nerves or blood vessels, and its structure is relatively simple. temporal mandibular joint : A joint of the jaw that connects it to the temporal bones of the skull. Chondrocytes : Cells that form and maintain the cartilage. What is Cartilage? Cartilage is a flexible connective tissue that differs from bone in several ways. For one, the primary cell types are chondrocytes as opposed to osteocytes. Chondrocytes are first chondroblast cells that produce the collagen extracellular matrix (ECM) and then get caught in the matrix. They lie in spaces called lacunae with up to eight chondrocytes located in each. Chondrocytes rely on diffusion to obtain nutrients as, unlike bone, cartilage is avascular, meaning there are no vessels to carry blood to cartilage tissue. This lack of blood supply causes cartilage to heal very slowly compared with bone. The base substance of cartilage is chondroitin sulfate, and the microarchitecture is substantially less organized than in bone. The cartilage fibrous sheath is called the perichondrium. The division of cells within cartilage occurs very slowly, and thus growth in cartilage is usually not based on an increase in size or mass of the cartilage itself. Articular cartilage function is dependent on the molecular composition of its ECM, which consists mainly of proteoglycans and collagens. The remodeling of cartilage is predominantly affected by changes and rearrangements of the collagen matrix, which responds to tensile and compressive forces experienced by the cartilage. Cartilage types: Images of microscopic views of the different types of cartilage: elastic, hyaline, and fibrous. Elastic cartilage has the most ECM; hyaline a middle amount; and fibrous cartilage has the least amount of ECM. Types of Cartilage There are three major types of cartilage: hyaline cartilage, fibrocartilage, and elastic cartilage. Hyaline Cartilage Hyaline cartilage is the most widespread cartilage type and, in adults, it forms the articular surfaces of long bones, the rib tips, the rings of the trachea, and parts of the skull. This type of cartilage is predominately collagen (yet with few collagen fibers), and its name refers to its glassy appearance. In the embryo, bones form first as hyaline cartilage before ossifying as development progresses. Hyaline cartilage is covered externally by a fibrous membrane, called the perichondrium, except at the articular ends of bones; it also occurs under the skin (for instance, ears and nose). Hyaline cartilage is found on many joint surfaces. It contains no nerves or blood vessels, and its structure is relatively simple. If a thin slice of cartilage is examined under the microscope, it will be found to consist of cells of a rounded or bluntly angular form, lying in groups of two or more in a granular or almost homogeneous matrix. These cells have generally straight outlines where they are in contact with each other, with the rest of their circumference rounded. They consist of translucent protoplasm in which fine interlacing filaments and minute granules are sometimes present. Embedded in this are one or two round nuclei with the usual intranuclear network. Fibrocartilage Fibrous cartilage has lots of collagen fibers (Type I and Type II), and it tends to grade into dense tendon and ligament tissue. White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the fibrous tissue, and its elasticity to the cartilaginous tissue. It is the only type of cartilage that contains type I collagen in addition to the normal type II. Fibrocartilage is found in the pubic symphysis, the annulus fibrosus of intervertebral discs, menisci, and the temporal mandibular joint. Elastic Cartilage Elastic or yellow cartilage contains elastic fiber networks and collagen fibers. The principal protein is elastin. Elastic cartilage is histologically similar to hyaline cartilage but contains many yellow elastic fibers lying in a solid matrix. These fibers form bundles that appear dark under a microscope. They give elastic cartilage great flexibility so it can withstand repeated bending. Chondrocytes lie between the fibers. Elastic cartilage is found in the epiglottis (part of the larynx) and the pinnae (the external ear flaps of many mammals, including humans).	1,225	common-pile/libretexts_filtered	https://med.libretexts.org/Courses/Okanagan_College/HKIN_110%3A_Human_Anatomy_I_for_Kinesiology/02%3A_The_Skeletal_System/2.07%3A_Cartilage/2.7A%3A_Structure_Type_and_Location_of_Cartilage	libretexts	libretexts-0000.json.gz:20580	https://med.libretexts.org/Courses/Okanagan_College/HKIN_110%3A_Human_Anatomy_I_for_Kinesiology/02%3A_The_Skeletal_System/2.07%3A_Cartilage/2.7A%3A_Structure_Type_and_Location_of_Cartilage
8aC9GqMkZdUA9fZz	Nursing Pharmacology-2e	8.12 Learning Activities Exercises Case Study 1 Mrs. Jones is a 65-year-old woman who has been diagnosed with major depressive disorder. She has been prescribed venlafaxine, an antidepressant medication, by her psychiatrist. She presents to the outpatient clinic with complaints of headaches, nausea, and dizziness. She reports that she has been taking venlafaxine for two weeks. Questions: - What is venlafaxine, and how does it work? - What are the common side effects of venlafaxine? - What are the potential drug interactions with venlafaxine? - What should be done if a client experiences side effects from venlafaxine? Case Study 2 Mr. Harshung is a 70-year-old man who has been diagnosed with Parkinson’s disease. He has been taking levodopa/carbidopa for the past year, but his symptoms have been worsening, and he has developed motor fluctuations. His neurologist has prescribed selegiline as an adjunct therapy to improve his symptoms. Questions: - What is selegiline, and how does it work? - What are the common side effects of selegiline? - What are the potential drug interactions with selegiline? - What should be done if a client misses a dose of selegiline? Note: Answers to the Case Studies can be found in the “Answer Key” sections at the end of the book. Test your clinical judgment with this NCLEX Next Generation-style bowtie question: CNS Assignment 1.[1] Test your clinical judgment with this NCLEX Next Generation-style bowtie question: CNS Assignment 2.[2]	306	common-pile/pressbooks_filtered	https://wtcs.pressbooks.pub/pharmacology2e/chapter/8-12-learning-activities/	pressbooks	pressbooks-0000.json.gz:83729	https://wtcs.pressbooks.pub/pharmacology2e/chapter/8-12-learning-activities/
fiR7wQx2ZgaxhFHm	The Diesel engine.	SAINT Louis, U. S. A. THE BUSCH-SULZER BROS. -DIESEL ENGINE COMPANY OWNS THE GOOD WILL AND ALL AMERICAN DIESEL ENGINE RIGHTS AND EXPERIENCES OF THE FOLLOWING: R. RUDOLF DIESEL of Munich, Germany, the distinguished inventor of the Diesel Engine. By agreement with Dr. Diesel this Company has the exclusive right to his services as a director and in a consulting capacity for the United States and Canada. He has given this Company power of attorney to defend the name DIESEL against all infringements. HE first American Diesel Engine. Built in Saint Louis and completed September 19, 1898, from designs acquired by Mr. Adolphus Busch, with all American patents and manufacturing rights. It developed sixty horse-power in two cylinders, while the first commercial Diesel built abroad, in the same year, developed but twenty-five in one cylinder. Installed at the AnheuserBusch Brewery it was the first Diesel to be placed under regular operating conditions. HISTORICAL HE Diesel engine was brought to the attention of the engineering world in 1 897, when our associate, Dr. Rudolf Diesel, completed his first successful engine at Augsburg, Germany. Among the first to realize the possibilities of the invention was Mr. Adolphus Busch, who immediately sought the professional advice of Col. E. D. Meier, later president of the American Society of Mechanical Engineers, as to its future. Mr. Busch and Col. Meier spent several weeks testing the engine at Augsburg, coming to the conclusion that Dr. Diesel's new engine was destined to exert an epoch making influence in the prime mover field, as it showed a thermal efficiency three times that of any steam plant then in operation. Subsequently a meeting was arranged at Cologne with Dr. Diesel, where a contract was signed which secured to Mr. Busch the entire and complete control of all Dr. Diesel's existing and future patents in the United States, its possessions, and Canada. Upon Mr. Busch's return to the United States he organized the Diesel Motor Company of America, but this company was soon superseded by the American Diesel Engine Company, it being found that the word motor as used in America was a misnomer when applied to large engines. Both these companies completed a large amount of successful experimental work, endeavoring during this period to maintain correspondence relative to such engineering problems as arose with other lessees then developing the Diesel engine abroad. This correspondence, however, netted practically insignificant results. Our predecessors, therefore, perfected our American type of Diesel to meet the peculiar conditions of American practice, in this manner developing some important elements of design since followed almost universally in Europe. The first engine constructed under our American rights was completed on September 19th, 1898. It was built in St. Louis and is illustrated on page 1 0. It operated in the Anheuser-Busch Brewery until superseded by larger units. In February, 1911, Mr. Busch, who had become the purchaser of the American Diesel Engine Company organized the present Company, the Busch-Sulzer Bros.Diesel Engine Co., thus associating his Diesel interests with the Gebriider Sulzer, of Winterthur, Switzerland. The Gebriider Sulzer are recognized as among the foremost builders of high-class machinery in the world, and without a peer in the development of the Diesel engine. tion to combine the long experience and only experience of Diesel building in America with the best that Europe affords in Diesel engineering, manufacturing and experiSulzer Brothers and Dr. Diesel thus becoming interested, both financially and as directors, with Mr. Busch. Our St. Louis plant, representing an investment of a million dollars, is equipped with every device and convenfor the proper handling of Diesel manufacture, AT VARIOUS LOADS HIS curve shows the results obtained under actual working conditions, and brings out the remarkable maintenance of efficiency, from full load down to half load, which is the unique characteristic of the Diesel Engine. DIESEL EFFICIENCY AND ECONOMY HE thermo-dynamic efficiency of the Diesel Engine, based on net useful output, varies between 32 per cent, and 35 per cent.; that of the simple Corliss or 4-valve engine is about 6 per cent.; the Corliss compounded, 9 per cent; the triple expansion engine, rarely 18 per cent. The very high efficiency of the Diesel makes it economically possible to purchase more expensive fuel than for steaming, and still show a handsome profit by its operation — and this without the necessity of considering its other advantages, which in many cases are as important as its extraordinary fuel economy. Diesel economy of space, fuel and attendance; its elimination of all stand-by expense; its fuel consumption from half load to 1 0 per cent, overload, almost in direct proportion to the load carried; and its readiness to start cold at a moment's notice — these are responsible for its unprecedented efficiency and magnificent economy. Diesel engines eliminate coal bunkers, stacks, boiler room and boiler room auxiliaries. They eliminate incompetent and careless stoking, firing, draft and water regulation— losses which, even in well regulated steam plants commonly amount to from 1 5 to 30 per cent, the value of the coal. They eliminate the varying factors to which coal itself is subject — its varying percentages of moisture, ash and oxygen; also calorific deterioration due to storage, which in half a year may amount to 1 2 per cent. — changes in composition which require careful changes in handling, if efficient combustion is to be approximated. plants of like power. A shortage of motive fluid, which sometimes occurs in steam plants, due to unexpected increases in load, where requirements cannot be anticipated, is a failing unknown to Diesel installations. No such shortage is possible where Diesels are installed. Furthermore, it is not possible to waste Diesel fuel through an unlocked for return to lighter loads. We guarantee the economy of the Diesel under everyday commercial conditions, although no builder of steam engines or accessory equipment will guarantee his product either as to steam or fuel consumption, except for brief full-load tests under exact specific limitations. It is an inherent failing of steam plants that they have factors which must be left to the discretion of attendants, factors which can be judged only by men skilled in analyzing temperature and draft records, flue gas, coal and ash analyses, water consumption, etc., etc. — variable factors to be constantly and intelligently analyzed if steaming efficiency is to be approximated. Diesel economy is not dependent on ceaseless vigilance and unerring judgment. It is controlled solely by means of a sensitive governor by which the rate of fuel injection is instantly modified to meet momentary load requirements. This it accomplishes with such precision that the conditions of parallel operation of alternators is controlled solely and perfectly by the regulation of fuel consumption. remarkable fuel saving of our Diesel engines : We have installed a plant in the middle west, consisting of two units of 240 B.H.P. each, which is saving its owner $10,500 a year in fuel or more than $30 per brake horse -power-year over the fuel cost of the old superseded steam equipment, which consisted of a condensing Corliss engine. This Diesel installation carries a steady, heavy mill drag twenty-four hours daily, together with the frequent intermittent service of an elevator of 350,000 bushels capacity. We refer the reader to section entitled "EVIDENCE" for numerous other examples. GUARANTEES HE Company guarantees the Diesel against defective parts due to faulty material or workmanship, and will replace such parts free of charge. The Company guarantees that the variation in speed of its engines will come within the close limits required for the parallel operation of 60-cycle alternating current generators. economy of fuel consumption. Copies of the guarantees which this Company offers and the tests by which the same are demonstrated will be cheerfully furnished to prospective purchasers. Every engine, before shipment, is carefully and thoroughly tested in our shops, at one-quarter, one-half, three-quarters, full and overload ; and a certified copy of the results is furnished with each engine. See sections of this general catalogue entitled "REPRESENTATIVE DIESEL INSTALLATIONS" and "EVIDENCE" for records which Diesels are making under everyday operating conditions. LIFE OF THE DIESEL T is not unusual to find steam engines and steam pumps which have been in service thirty years, maintained in fair state of up-keep by repairs and renewals — the frame, shaft, flywheel and foundation, representing a large part of their original cost, continuing in service. However, the engine and pumps represent less than forty per cent, of the cost of a steam installation — approximately sixty per cent, being in the boilers, heaters, condensers, stack and piping. Some of these features, the boilers notably, each year show a marked deterioration and loss in efficiency. None of these features exist in the Diesel, and its life will compare most favorably with the entire equipment of a steam plant, its efficiency throughout its life remaining practically unimpaired. The story of the Diesel Engine is quite different from that of gradual obsolescence of the old steam plant. Ten, even fifteen years ago, when the Diesel was first built, it showed the same extraordinary efficiency. No builder of Diesels abroad, nor do we here, expect to increase its thermal efficiency to a very great extent. Diesel progress has been one of increasing refinements, a lengthening of its life, an increasing of its reliability and facility in handling, in its close governing under varying loads, etc. In these it is unapproached by any other type of prime mover. The heavily designed frame, the shaft, and connecting rods, the massive fly wheel, etc., form a much larger proportionate cost of Diesel equipment than these parts do in a steam installation, and since these non-wearing parts form the larger cost, those parts which wear and deteriorate most, of necessity, form the smaller and a lesser proportionate part of Diesel equipment than they do with steam equipment. It is easy to realize this — if one will recall that the entire boiler equipment with all its auxiliaries is eliminated, and that wear and tear is confined to parts which represent less than one-third of the original Diesel investment. In the steam engine and in all explosive and hot-bulb types of internal combustion engines, leaky valves and worn cylinders result in reduced efficiency, the cause of which is not always apparent, and if the engine is not loaded to capacity may not be detected until much damage has been done and much money lost in poor efficiency. The Diesel, depending upon perfect compression for its ignition, does not permit a continuance of such losses; if compression fails ignition ceases and the engine stops. In other words such conditions as militate against the life of engines and their economy absolutely cannot exist long enough in the Diesel to do serious damage, or eat up fuel in useless effort. Another feature of the Diesel which adds to its life, and which sets the Diesel apart from all explosive types, is the absence of any sudden rise in pressure at instant of combustion. Gradual introduction of fuel during ten per cent, to twelve per cent, of the combustion stroke results in a more uniform stress and longer life. There are two 225 B.H.P. Diesel engines in a Texas power house, installed nine years, during which period they have operated on an average eighteen hours per day. Cylinders of these engines have never been rebored, show negligible wear and are smooth and bright as glass. With the same handling in the future as they have had in the past, they should outlive a steam plant of like capacity. CONSTRUCTION IFTEEN years of Diesel building have shown us one conspicuous fact in relation to construction which we deem fundamental; that if a Diesel were built and operated under average conditions, with no more care given to material and construction than is usual in steam engine practice, Diesel efficiency would be greatly impaired and operation would not be reliable. Our close scrutiny of details, and our strict adherence to the highest type of engineering are responsible for the success which has attended the type constructed by this Company. We commenced building Diesel engines in 1898, in the same year commercial development began in Europe, and have since given our best attention to the perfection of a design in consonance with American practice which would embody all those features found by experience to increase the remarkable reliability of Diesel operation. Our type, characterized by compact simplicity of design, embodies great convenience with highest efficiency. Our methods assure perfect interchangeability of parts, all of which are liberally proportioned, with workmanship, material and design standardized and in strict conformity with our general practice, determined by an experience in Diesel building extending from its introduction to the present time. 1TARTING the Diesel in an United States Naval Torpedo Station. A twist of the wrist does it. In less than three minutes a Diesel will take on full load. OPERATION HE Diesel Engine, if designed and built in accordance with the lessons of practical experience is absolutely dependable for the severest service and the longest non-stop operation. Our customers operate Diesel Engines over regular periods of six weeks to two months without shut-down. They operate them without realignment or other major adjustment for periods of years. Even for the severest service our Diesel engines require less attendance than any other type of prime mover. The duties of attendance during operating periods consist principally of watching lubrication, seeing that the flow of cooling water is uninterrupted and in keeping the engine clean. A first-class mechanic or steam engineer is amply qualified for this service and may be easily trained to operate the Diesel intelligently. The various duties during shut-down periods should be divided between examination and adjustment. Periodic inspections should occur at regular intervals more or less frequent, depending upon the severity of the service. The actual work involves grinding valves, adjusting boxes, packing glands, and the renewal of lubricating oil — the same sort of duties found in every steam plant. There are, of course, no boiler tubes to replace, boiler scale to remove, flues to clean, heat insulation and grates to renew, brick work to be patched or the like. So that, more than anything else, Diesel operation and attendance mean watchfulness, as there is an almost complete elimination of manual effort. As it is with steam, procrastination is the root of most trouble, and the test of the fitness of an operating engineer. The Stationary Diesel which we build belongs to the four-stroke cycle type of internal combustion engine, the cycle of each cylinder being completed in two revolutions of the crank or four strokes of the piston; (first) INDUCTION of pure air, (second) COMPRESSION of pure air, (third) COMBUSTION of oil sprayed in the compressed air, and EXPANSION of the products of this combustion; (fourth) EXPULSION of exhaust gasses. 4. EXHAUST. The Diesel does not contain an explosive mixture at any time, no explosion ever occurs in its cycle of operation, and the Diesel never was and never will be subject to preignition, as air only is compressed. No carburetor, no vaporizer, no hot -bulb, flame, or electrical ignition apparatus is ever used. Combustion of the oil spray is due solely to the heat generated by compression on the second (COMPRESSION) Stroke of the cycle. The spraying of the oil into the cylinder covers from 1 0 per cent, to 1 2 per cent, of the COMBUSTION stroke. It is a gradual burning, continuing for a considerable time after all the fuel has been injected — a non-explosive, internal combustion resulting in uniform stress and long life — the Diesel is the only engine which has it. COMBUSTION RUDE Oil, or residuum, commonly known as fuel oil, burning temperature 120° to 300° Fahrenheit, forced through an atomizer by an air blast, enters the combustion space of the cylinder at the point of highest compression when the air, drawn in on the suction stroke, has been compressed to 460 pounds and thereby raised in temperature to 1000° F. This is a temperature 3 to 8 times that required for ignition. Instant combustion follows, and every combustible particle burnt. Diesel combustion is combustion in incandescent atmosphere under ideal conditions insuring perfect combustion, smokeless exhaust, and the highest thermal efficiency known. DIESEL FUEL HEAP fuel oils containing non-combustible substances, or high percentages of sulphur are not always the most economical Diesel fuels. Such oils are bad for all internal combustion engines regardless of their type or design, although there are sometimes market conditions under which they may be used profitably. Will the saving, amounting to the difference in cost between such oils and those free from such impurities, warrant the cost of frequent replacements of those parts attacked by the sulphur and worn by the non-combustible matter which the cheaper contain? This is the sum and substance of the fuel problem, and varies in no respect, except in degree, from that confronting every plant manager, no matter what type of prime mover he may operate. As to degree — coals for steaming vary greatly in heat units per pound, cost of handling, etc.; oils for hot bulb and explosion type engines are available only between certain narrow limits; as to oils for the Diesel, there is the greatest latitude in choice, oils from practically all fields having been used successfully, their thermal value never entering as a factor in their purchase or cost. Unlike coal, which has a calorific value ranging from 8,000 to 1 4,500, all heavy oils, such as Diesels consume, have approximately the same high heat value — namely 1 9,000 B.T.U. per pound. The Company will advise its customers and interested inquirers as to the availability of any particular oil and invites their correspondence on this subject. Fuel easily handled and stored. Larger quantities of reserve fuel easily stored. No depreciation on stored fuel. No losses of fuel in transit. AT LIGHT LOADS HIS chart shows the range of load common to Central Stations. It shows that where the Diesel consumes five barrels of oil the condensing steam engine consumes twenty-five barrels and the simple steam engine forty-five barrels. This gives an economy in favor of the Diesel of one to five and one to nine. -. The chart shows a day load of 75 H.P. rising at dusk to a peak of approximately 200 H.P. falling to an after midnight load of 93 H.P. The Diesel carries this day load of 75 H.P. on six gallons of oil per hour. Ask your engineer to compare this record with your results. How much fuel do you use per hour during off-peak periods? How much per day? CENTRAL STATION PRACTICE N December, 1 907, Diesel engines to the amount of 9,665 brake horse-power were operating in Central Station plants in the United States. Of the plants operating this Diesel power, 75 per cent, have bought additional units, their re-orders, in brake horse-power, amounting to 155 per cent, of the original amount purchased on first order, 55 per cent, re-ordering after original purchases had shown five years or more of successful, economical operation. The horse-power sold on re-order to these Central station plants now amounts to 68 per cent, of all the horse-power they had in operation in 1907. That sold on re-order up to and including December, 1907, was 29 per cent, of that installed at the time; while that bought on re-order at this date is 38 per cent, of that now in operation. Smallest equipment operated in a Diesel central station is of 75 B.H.P., largest 1 1 25 B.H.P. All the above figures refer to strictly central stations deriving all income from such service. This Company has equipped central stations of more than double the size of largest indicated above, but which are engaged in other lines also, as in manufacturing, mining and street railway operation — all of which have ordered additional Diesel units. Of those which have re-ordered, 24 per cent, have made three distinct purchases, each in a different year, and one power and light company, with Diesels installed in two of their plants, has made four purchases: 225 B.H.P. in 1912 These repeat orders over so many years, show that the Diesel is well adapted to Central Station requirements of regulation, reliability and continuous operation. PARALLEL OPERATION Diesel speed regulation under change of load ranks with that of the best types of automatic steam engines. No difficulty is experienced in the operation of generating units in parallel. Reference can be given to large numbers of such plants operating in parallel with other Diesel units, steam equipment and water power, in different parts of the country. RELIABILITY AND CONTINUOUS OPERATION In the Diesel Engine, combustion by the heat of compression does away with ignition devices, mixers, carburetors and back firing, limiting the cause of stoppage to a cessation of fuel or injection air. Any part working out of adjustment gives such ample notice of a fault, that, generally, attenion may be deferred to regular shut-down periods. One 225 horse-power Diesel Engine installed in an electric light plant in Illinois, operated without reserve power, 24 hours per day — 6f days per week — for 2^ years with but two minor shut-downs. In the opinion of operating engineers, who have had several years experience, the Diesel is fully as reliable as steam. UNDER VARIABLE LOAD CONDITIONS The refinements of coal handling machinery, superheaters, economizers, and labor saving devices commonly found in large modern steam plants are not economically introduced into small central stations, where the varying load condition is most marked. Therefore, the kilowatt costs several times as much in the small steam installation as in the large well equipped station. In contrast to this the small Diesel installation shows a kilowatt cost which compares very favorably with that obtained in the larger plants operated by Diesels or the most refined steam equipment. The installation of small Diesel units allows a gradual increase in capacity to meet growing load conditions, and has the additional advantage that the factor of safety for continuous operation increases with the number of units installed — any necessity for repairs or adjustments affecting a smaller percentage of the total capacity of the plant. FLOUR MILL DRIVES IESELS are installed in flour mills which have both electrical and line shaft drives. With both types Diesel Engines are showing an economy which has amply justified their installation. A mill and elevator company operating a 320 HP. and an 80 HP. Corliss, both running condensing, changed over to Diesel equipment. An 800 barrel mill is now driven by a 250 HP. motor, a 400 barrel mill by a 125 HP. motor, the cleaning machines by a 50 HP. motor, and the elevator by 7 motors aggregating 200 HP. This mill, located in the middle west, burned an average of 55 barrels of oil per day under boilers, the lowest consumption recorded having been 48 barrels. It is now consuming in its Diesel engines an average of 1 2 barrels. It cost this mill more than 4i times as much to run formerly as now — for fuel alone. Add to this great Diesel economy in fuel, the saving in labor, and the showing is well worth investigating. The owner of this mill will tell you that he is saving over $ 1 0,500.00 per year in fuel alone. Figuring the oil at 2\ cents per gallon, the local price, the fuel cost is only 1 0^ mills per barrel of flour. As the efficiency of the smallest Diesel more nearly approaches that of the largest, than does the efficiency of a small steam plant that of a large one, a flour mill requiring only 1 20 B.H.P., Diesel operated, would show a proportionately greater saving. in Texas. The first Diesel to be used in a flour mill was installed in 1905, and has been in successful economical operation ever since. This engine is clutch-connected to line shaft. In the REPRESENTATIVE DIESEL INSTALLATIONS section, under Kansas and Texas, two roller mill installations will be found illustrated. LTHOUGH the Diesel turns to useful account approximately twice as much of the heat value of fuel as do steam engines or turbines, yet, with about 32 per cent, to 35 per cent, of the heat transformed into useful mechanical energy, there remains 43 to 40 per cent, not available to that purpose — turned into heat. In this installation the exhaust gases from the Diesels pass through exhaust gas heat economizers (illustrated and described on page 46). The returns from the hot water heating system of this plant pass through three of them, arranged in parallel, one for each engine. After absorbing the heat of the gases, with a consequent rise in temperature, the water passes from them to heaters which are supplied with steam coils heated by the steam of high pressure boilers, used also for the operation of the steam hammers in the forge shop. From the steam heaters the water again passes out and re-circulates through the buildings. The cooling water from the cylinder jackets, at a temperature of about 140 degrees, runs into a hot well, this water being utilized as boiler feed and in lavatories. In this manner the system employed in this plant, the first in this country to utilize heat from both these Diesel sources, conserves to heating purposes at least 60 per cent, of the heat value of the fuel not transformed into mechanical effort. The result is a very decided economy in fuel for winter heating, an economy which, when added to that of the Diesel as a prime mover, makes for an overall fuel economy which is superb. Another important economic feature of this plant is automatic machine tool control. While this is not a feature which can be used only with Diesel engines, individual motor drive with automatic control is, however, one of those important items subsidiary to the Diesel making for general manufacturing economy. It is a system which necessarily has a maximum variation in load, as current is consumed only during periods of actual productive work. Constant voltage is its only requisite to successful operation, and this is easily provided by the Diesel, any increase or decrease in load being immediately reflected in a changed rate of fuel consumption, always in proportion to the productive work being done. The Diesel engine equipment of this plant consists of three 4-stroke cycle Diesel units of 225 B.H.P. each, running at 164 R.P.M., direct connected to 160 K.W. 1 1 5-230 volt direct current generators. The fuel oil storage tanks, of which there are two, are buried at the side of a private railroad siding adjacent to the power house. Oil flows into these tanks from tank cars by gravity. Oil fired boilers are used in the power house — they supply the major portion of the heat required for shop heating in the winter and the steam for the operation of the steam hammers in the forge shop. Diesel exhaust is noiseless, colorless and odorless, and as induced draft is used in conjunction with the boilers this installation is without visible stacks of any kind. No coal is used on the premises. Even in the forge shop oil has been substituted throughout on account of its ease in handling, its economy and the precision of its control. This company considers that the use of the Diesel engine, together with such heat conserving equipment as is employed in this plant, assures to all plants having a heating problem which will install Diesels, an overall economy which cannot be approached by any other type of prime mover. ICE AND REFRIGERATION E have installed Diesels in a number of ice and refrigeration plants. Some are operated in conjunction with electric light stations, some with water works, some with breweries, some as distinct plants. These Diesels are connected to load by belted and electrical drives and are particularly well adapted to ice manufacture, showing a reduction in fuel cost of 40 per cent, to 80 per cent, and an operating expense closely proportioned to output. Inasmuch as the fuel consumption of the Diesel is in direct proportion to load requirements, between half and full load, it follows that, with one Diesel engine, the same fuel cost per ton of ice will be realized at half as at full capacity; with two Diesels, at one quarter to full capacity, etc. This flexibility is appreciated in off seasons. In the summer when ice making continues twenty-four hours daily the Diesel is reliable for full capacity, twenty-four hours per day, for the full season, with one or two shut downs for inspection and possible adjustments. Six years ago when an ice plant in the south installed its first Diesel engine it was consuming under its boilers an average of $500 worth of fuel per month. One year later, after its second Diesel was installed and the steam plant abandoned, and the business had increased, the fuel consumption averaged only $75 monthly. The third Diesel this company purchased was installed in 1912, five years after they had bought their first, ample time for them to have discovered whether or not the Diesel fully met the requirements of ice and refrigeration service. Their Diesels operate two 125 K.W. and one 1 5 0 K.W., A. C. generators of 2300 volts, which are direct connected. Their equipment, including the forty ton ice plant, is operated on twenty-four hour service by one chief engineer and two assistant engineers — more help not required. The Diesel enabled this company to produce a raw water can ice which their competitors could not equal and which captured every retail dealer in town, forcing their rivals to retail their own ice. This plant produces cakes weighing over six hundred pounds without flaw or blemish which are described as blocks of crystal. Two views from the largest Diesel ice and refrigeration plant, which is situated in New York, are reproduced herewith. It is equipped with six Diesels aggregating 1245 B.H.P. and has a capacity equivalent to 455 tons of ice ; its ice machines, pumps and hoists being operated by motors. gress of Ice and Refrigeration held at Chicago, M September 17-25, 1913, written by Messrs. R. H. Tait and L. C. Nordmeyer of the firm of TaitNordmeyer Engineering Company, Saint Louis. It has been recast for us by the authors — use being made of the parallel column method of comparison in such manner as to insure the most vivid and ready conception of their estimates, the calculations by which they figured them and the conclusions they reached. It is a technical bulletin on the use of the Diesel Engine in ice plants. We will cheerfully send this bulletin to anyone with a power problem in his ice or refrigerating plant. It contrasts simple steam, compound condensing steam, and Diesel engined 60 ton ice and 1 2 ton refrigeration capacity plants. It gives the building and operating costs of each and other valuable information to the man who is confronted with a power problem. MISCELLANEOUS DIESEL DRIVES NTIRELY aside from the great economic advantage of the Diesel, it is wonderfully well adapted to high pressure fire service, or any other emergency service which requires instant readiness to start, ability to make long non-stop runs, and absolute reliability. In such plants stand-by expense is often the largest single item and the Diesel eliminates it. If prepared for starting, when shut down, the Diesel can take on full load in less than one minute from notice to start. These characteristics entitle it to the most serious consideration of all having such requirements. In the foregoing pages there has been described the economic advantages of the Diesel in central stations, refrigeration plants, flour mills and factories. The horsepower thus employed represents 76 per cent, of the total installed. On the following pages we mention a number of different lines of industry in which Diesels have been running over a period of years — they will give you an idea as to the great range of application to which they have been put. Our Sales and Engineering Departments would take pleasure in giving a prospective power purchaser all the special information within their experience as to the Diesel's availability under any specific conditions. DIESEL INDUSTRIAL APPLICATIONS OLLOWING is a list of installations illustrating the Diesel's applicability to various lines of industry. A representative installation of either the oldest or largest of each industry is here referred to by its date of installation and location by state. Thirty per cent, of the total Diesel horse-power sold has been on re-order; and the re-orders have amounted to more than the original purchases. On an average those firms which have added Diesels to their first purchases, have more than doubled their plants by fifteen per cent. One central station plant has re-ordered three times, six years after the original purchase, one year after the second, and one year after the third, making four distinct purchases in eight years, which clearly indicates the satisfaction which the Diesel gives to those who have come to know it well. All installations here referred to have been in successful operation since the date mentioned. and application, but there are fine installations in eight more states — Arkansas, Iowa, Louisiana, Missouri, New Hampshire, South Carolina, South Dakota and Tennessee — some of which are illustrated elsewhere in this catalogue. EXHAUST GAS HEAT ECONOMIZERS XHAUST Gas Heat Economizers which extract the heat of exhaust gases and transfer the same to water find economical uses in such industries as require hot water, as in the washing of raw materials or finished products, in hot water heating systems for buildings and shops, in lavatories, or as boiler feed. At small expense for the equipment and its installation these economizers in conjunction with the engine jackets, will save at least sixty per cent, of the heat which would otherwise be wasted, or 2800 British thermal units per brake horsepower-hour, giving the Diesel an unapproached overall economy. The following figures are taken from a test in a Sulzer built installation of 300 B.H.P. in a woolen mill at Biirglen, Switzerland, where the heat recovered is used in heating the factory and in the washing of wool and yarns. The tests were made by Prof. J. Cochand, of Lausanne and Engineer M. Hottinger, of Winterthur, Switzerland, their report being published in the Zeitschrift des Vereines Deutscher Ingenieure, of March 23rd, 1912. Two economizers of 325 square feet heating surface each were used, connected in series so that the exhaust traveled through one then the other. The water, on leaving the engine, passed through them on the counter current principle, in the opposite direction to the flow of the gases. 1 232 gallons of water passed through the heaters per hour entering at 1 23.8 degrees F. and leaving at 1 67.9 degrees F. The temperature of the water as it entered the cylinder jackets — 70 degrees F. Deducting the 1 8 per cent, lost this gives an overall fuel economy of 82 per cent., which is not equalled by any other type of prime mover. As the amount of heat recovered by the economizers and from the cooling water amounts to 48.5 per cent, it may be readily seen that for every $1,000 spent in Diesel fuel but $515.00 worth can be charged to the generation of power. $485.00 worth, or that saved from these sources is utilized in the form of heated water. 48.5 per cent, is a large saving, especially so, considering the small cost of the equipment. But the saving is really much greater. $485.00 worth of oil burnt under a boiler would not come within 20 per cent, to 25 per cent, of the heat recovered and utilized by the exhaust gas heat economizers of this Biirglen plant. This Company employs this system of heat conservation in its Saint Louis works and is prepared to contract for similar installations in conjunction with all Diesel engined plants. INSTALLATIONS FORTY INSTALLATIONS IN TWENTY-THREE STATES ARE REPRESENTED IN THE FOLLOWING VIEWS OF DIESEL POWER PLANTS. SPECIFIC INFORMATION CONCERNING OUR NUMEROUS INSTALLATIONS FURNISHED PROSPECTIVE PURCHASERS ON APPLICATION. IN ONE PART OF THE COUNTRY OUR DIESELS ARE LOCATED IN MINES; IN ANOTHER, FACTORIES AND CENTRAL STATIONS; IN ANOTHER, AS AUXILIARIES TO WATER POWER— ONE SELLING ANOTHER. DIESEL APPLICATIONS COVER FIFTY- EIGHT DIFFERENT LINES OF INDUSTRY. IN EVERY LOCALITY WHERE SOLD, INSTALLATIONS HAVE MULTIPLIED. DIESEL POWER PLANTS, SUCCESSFUL AND ECONOMICAL IN OPERATION, ARE OUR BEST SALES AGENTS. ARIZONA IHIS double unit consists of two 225 B.H.P. Diesel engines. It is located at a copper mine at an elevation of 5,000 feet. It is connected by rope drive to a positive pressure blower. As IRST Diesel installed 75 B.H.P., second 225 B.H.P. They operate at altitude of 5300 feet. Larger, operating triplex pumps, is direct connected to 150 K.W., 240 volt, D.C. generator. It runs under an average load of 400 amperes, 24 hours daily, making non-stop runs, amounting to forty days. This engine, in spite of the high altitude and an average load factor of 0.8, consumes only nine gallons fuel oil per hour, equivalent to 9.4 gallons per 100 K.W. hours, or 6.2 gallons per 100 B.H.P. hours assuming a generator efficiency of 87 per cent. CONNECTICUT OTAL assets of this municipal plant $200,331.59, all paid for out of earnings, except $22,500, representing initial bonded debt. Never required help by taxation, although operating at lowest rates in the State. First Diesel bought in 1905, second 1907, third 1910, no steam equipment bought since first Diesel was installed. The General Superintendent, writing to prospective power purchasers, claims for his Diesels: quick response to variations in load, taking full rating without apparent effort; regulation as close FLORIDA \|IGHT, twin triple-cylinder, engines, 450 B.H.P. each. They operate the largest phosphate mines in Florida. They say the Diesel makes oil the cheapest fuel in this State. ILLINOIS E installed one 225 B.H.P. Diesel about a year ago, operate twenty-four hour service, shutting down Sundays for five hours, and in the year's run, our service has been shut down but once, for two hours. This speaks for itself. We have been pleasantly surprised at the performance of the engine, and the fuel consumption is below the guarantee of the builders." Since old steam plant was discarded by the receivers and the INDIANA POWER station supplying a city of 5,000 and four small towns within fourteen miles. Current used for lighting, power and in water works. The two engines shown are 225 B.H.P. each, direct connected to alternating current generators. A twenty-four hour service is maintained, one engine running continuously, the other on peak loads. Daily fuel consumption 200 gallons. KANSAS mEN thousand five hundred dollars represents the yearly saving in fuel of these Diesel Units over the old superseded steam equipment. A greater saving will be made when the third unit, now on order, is installed. The equipment consists of two 240 B.H.P. units, direct connected to generators, which furnish power to a 1,200 barrel mill and a 350,000 bushel elevator. nHIS Diesel consumes daily 45 gallons of fuel oil, \vhereas the old steam equipment consumed 280 gallons on the same schedule, under the same load conditions. Sixty-cycle alternating current is generated and used for lighting, miscellaneous power requirements, and for driving water works pumps. Its success has lead two other Kansas municipalities to install Diesel equipment. LOUISIANA HIS installation consists of two Diesel engines of 120 B.H.P. each, driving 60 cycle alternating current generators; 100 gallons of fuel oil consumed daily furnishing the city, of 5,000 inhabitants, with all its water, electric light and commercial service. The electrically driven pumps are shown below. Two neighboring cities after watching these engines operate for a year, installed Diesels in their plants — proof of Diesel economy and reliability. MARYLAND llpllIANOS, of one of the most noted makes, are made in \|l^ l\| this factory, operated by the Diesel unit illustrated. It has been operating steadily for the past eight years, developing 225 B.H.P. at a speed of 165 RP.M. It is direct connected to a 150 K. W. direct current generator. MASSACHUSETTS HIS large cotton mill employs its 450 B.H.P. double unit on a mill drive. Direct connected to alternator, it has been in daily operation for three years and has proven a most reliable source of power, ready at a moment's notice. Its ability to carry a steady, heavy mill drag and its freedom from smoke and soot, makes the Diesel a very desirable prime mover for the operation of textile mills. It occupies small space, requires very little attendance, consumes its fuel in proportion to requirements, and has no external flame or fire about it. have been in closer touch with this Massachusetts plant, consisting of 900 B.H.P. in three Diesel units than with any other, each week receiving a full operating report. Average fuel consumption 8.24 gallons per 100 net K.W. hours — equal to 6 gallons per 100 net B.H.P. hours. We do all we can to co-operate with Diesel owners and operators by maintaining a staff of inspecting engineers. HIS municipal plant, in a city of 5,000 inhabitants, started in 1903 with two Diesels of 120 B.H.P. each, shown in foreground, adding one of 225 B.H.P. in 1906 and another of like size in 1911 — which speaks well for the satisfaction this city finds in Diesel operation. They operate 60 cycle generators in parallel, having a combined capacity of 500 kilowatts. The plant has 460 customers, to whom it supplies light and power for 310 H.P. of motors. It serves the city free, and is a paying institution without any account being taken of its municipal load. MINNESOTA HERE are three installations of Diesels in this State which are auxiliary to water power. Two installed on showing of first. Writing to parties investigating our claims an engineer of one of these plants wrote: "We think the Diesel is more durable and dependable than steam. In answer to second part, I beg to advise steam cost for fuel $26.00 for 24 hours; Diesel, $3.40 for fuel and $0.50 for lubricating oil on -f load. We do not now charge any more when using engine than for water power, 10 cents per K.W.; when using steam we always had to raise price to 12 cents and it was hard to get even at that rate." MISSOURI FllIRST Diesel built in America and the first to be placed l\| under regular commercial load, here or abroad, was installed in the Anheuser-Busch Brewery, Saint Louis, in 1 898. It operated in the bottling department until 1911, when it was superseded by the larger modern units shown. \|HIS little Diesel Central Station of two units of 120 B.H.P. each, located under the shadow of one of the big distributing stations of the great Keokuk Dam water power plant, is generating and selling electric current for less than its big rival and making money. WHEN THE RIVERS RUN DRY HE manager of this plant in writing to the company which had sold the electrical apparatus used in conjunction with its Diesels stated : "I will say that as an auxiliary I consider the Diesel the best proposition that can be installed. * * * We are operating our Diesel units in parallel with our Hydro-Electric plant, located seventeen miles away, and we have never had the slightest difficulty. Another nice feature, where there is sufficient storage capacity, is the fact that from a 300 K.W. Diesel set, you can generate at least 7,000 K.W. hours in a twenty-four hour run, holding back sufficient water to take care of the peak loads. * * * We are buying two more engines, after having had nearly three years' experience with our other two." NEW JERSEY [JT^TJIOOLEN fabrics are manufactured in this mill, which \|l l\| is operated by the 1 70 B.H.P. Diesel engine shown. Transmission is by rope drive. The engine has been in service ten to twelve hours every week day for eight years, having been installed in 1905. Oil consumption for this period is calculated by the mill at less than 7 gallons per 100 net B.H.P. hours. NEW MEXICO \|N the irrigated sections of the Southwest central station plants find a good business furnishing electric current to farmers to run their irrigation pumps. This is what the 450 B.H.P. plant shown does besides lighting the streets and furnishing current for commercial purposes in a rapidly growing city in New Mexico. NEW YORK IN ideal installation. It consists of two 120 B.H.P. Diesels installed in 1907 and a third of 225 B.H.P. 1912. These engines operate 60 cycle alternators in parallel. Their exhaust is passed into pits for muffling and reaches the atmosphere through the vent shown. Diesel owners dare to operate without spare units, making long continuous runs. Many Diesel plants are operated without shutting down for periods of over six weeks. Massive construction, finest materials, best of workmanship— these are the Diesel's guarantee of reliability. KITING a prospective purchaser of Diesels, the manager of this Company stated: "We have not been without use of the engine any hour when required. It has never given us any trouble, and requires scarcely any attention. The entire expense of maintenance would not be more than $200.00 for the seven years that we have had it, and of that $200.00 we have spent, we have got half the parts in stock now for emergency. When we need additional power there will be nothing considered except another Diesel." IN ice and refrigeration plant of 455 tons capacity equipped with six Diesel units aggregating 1245 B.H.P., two of which are belt connected to ammonia compressors driven at constant speed, while two compressors are driven by variable speed motors. Raw water block ice is manufactured. Plant operates at very low cost and with great economy in space. Send for bulletin on this plant. DIESEL located in a piano factory and surrounded by inflammable material, in the heart of New York's congested fire district. 1 70 B.H.P. free from fire risk. HE installation of this 225 B.H.P. engine required no changes to the old steam plant with which it operates. As is often the case, the existing engine room proved large enough to accommodate it. In many plants, as in the largest in the country producing encaustic tiling, Diesels supplement steam, utilizing to the best and most economical advantage available or idle space. Owing to the high economy of the Diesel, it is generally found most economical to load it to full capacity and let it carry the brunt of the power burden, leaving the steam installation to make up balance of requirements or carry peak loads. This makes an excellent arrangement, sufficient power being developed by the steam plant to supply the requisite exhaust steam for winter heating or manufacturing requirements. ROM December 1905 to May first, 1906, according to published reports to tax payers, old steam plant caused a deficit of $6,714.49, met by taxation. From May twelfth, 1 906, to October first, 1 907, their two Diesels earned a surplus over all operating expenses of $3,928.71, thus turning a village liability into an asset. It was calculated by their engineer that during this period the Diesels saved $9,984.49 for fuel and $1,700.00 for day and night labor in boiler room — a total of $ 1 1 ,684.49. OKLAHOMA NE of the most difficult and most dusty drives imaginable is that found in a cement manufacturing plant. Large heavy machinery such as rock crushers are constantly in use, causing heavy vibrations in the transmission and a very fluctuating load. In such plants extra precaution is taken in filtering the air which is admitted to the cylinders so as to prevent scoring and wear. This is the only precaution necessary on such a drive, the engine caring for this class of service perfectly. This installation, installed in 1912, consists of one 170 B.H.P. Diesel unit, belted to line shaft. PENNSYLVANIA HE three Diesels included in this plant, which manufactures city gas, are direct connected to alternating current generators. The power is used in manufacture and distribution by means of individual motor drives. This was one of the first plants in the country to use Diesel engines, having purchased two units of 75 HP. in 1904, which are now supplemented by the modern units shown; in operation since 1907. flThe Diesel was introduced into this plant, where gas was available at cost, solely because of its magnificent fuel economy. MODERN Diesel installation in which the first two Diesels were installed in 1911 and additional units in 1912 and 1913. The plant now consists of six Diesels developing 1,350 B.H.P., operating crushers, grinders, chasers and finishers used in the manufacture of chocolate. Independent motor driven compressors have the advantage of great flexibility, being independent of the particular Diesel units in operation. \|HIS school for girls, which is located in the open country, belongs to the correctional system of institutions maintained by Pennsylvania. The state installed this Diesel of 120 B.H.P. on its showing as an economical power unit, which requires a minimum of attendance. This installation operates without regular attendance, generating a dependable direct current lighting and power supply to the entire satisfaction of the officials. 450 B.H.P. Diesel unit, direct connected to A. C. generator. In service eight years. No depreciation while idle, no stand-by expense. Starts any time in two or three minutes and maintains constant speed under variable loads. This unit used in the manufacture of silverware has been in constant service since 1 905. It is operated in parallel with older steam equipment. RHODE ISLAND \|rT~]\| CENTRAL Station in which Diesels began immedi\|ll\| ately to demonstrate their great economy. First Diesel installed in 1906. Use of steam discontinued and second Diesel installed 1907. Good profits and reliable service developing new business, three more were added in 1911. Plant now serves several neighboring towns and villages with 1 125 B.H.P. SOUTH DAKOTA \|\|ryi\|\|HIS plant operated one Diesel unit of 225 B.H.P. for ILLJI one year. Then having become convinced of the Diesels advantages, reliability and economy, the owners added an additional unit of 225 B.H.P. It is one of numerous steam plants in which Diesels have superseded steam altogether. TENNESSEE HE municipal electric plant of a progressive little town of 3,000 inhabitants, which in 1912 installed its first Diesel of 225 B.H.P. direct connected to a 200 K.V.A. alternator. As can be seen, the city fathers wisely put their money into the engine instead of into the building. 675 B.H.P. central station. 3 phase, 2300-volt, 60cycle. Average yearly cost of current 6.78 mills per K. W.H. — oil at $ 1 .05 per bbl. Compressors direct coupled. IESELS are now operating several flour mills and elevators in different parts of the country with eminently satisfactory results. Economy of operation is the one big factor in such [PACE economy of Diesel installations strikingly shown. A belted 225 B.H.P. Diesel. Plant capacity: Refrigeration 35 tons, Ice 25 tons; Electric power 50 K.V.A. THREE locomotive and car shops in this State have Diesel installations, operating traveling cranes, heavy machine tools and lighting buildings and yards. The plant illustrated installed two 120 B.H.P. Diesels in 1907, an additional unit of 225 B.H.P. being added in 1909. The Superintendent of Motive Power and Rolling Stock of one of these plants wrote a brother official in another state: "I consider the Diesel Engine one of the most satisfactory and economical power plants obtainable. It is possible that the very close attention which this engine has received since it has been installed has resulted in its very successful operation both in point of economy as to fuel and repairs. The repairs which have been necessary are of so slight a nature that we have kept no special record as to the cost, but it is very low." WISCONSIN •T1 HE first municipal water and light plant to install * l\| Diesels in the world; operates four engines; 600 B.HP. installed in 1905-1 1-13. Eighty arc lamps at $28.00 per lamp year cover operating cost — all other municipal lighting and 1 46,000,000 gallons pumpage free. UNITED STATES NAVY HE pontoon crane shown is used at a United States Navy Yard on the Atlantic Coast. The crane is of 1 50 tons capacity, and is operated by the 225 B.H.P. Diesel engine shown. This installation has been in successful operation one year. A duplicate of the above installation is serving the government at Pearl Harbor, Hawaii. THIS COMPANY WISHES TO STATE THAT THE LARGE NUMBER OF ENGINES SOLD MAKES IT POSSIBLE TO RENDER TO ITS CUSTOMERS EXCEPTIONAL SERVICE. IT MAINTAINS A STAFF OF ERECTING AND OPERATING ENGINEERS OF LONG AND VARIED EXPERIENCE ENGAGED SOLELY IN VISITING OUR CUSTOMERS' INSTALLATIONS. THE COMPANY MAINTAINS A CONSTANT INTEREST IN ALL DIESELS SOLD AND ENDEAVORS AT ALL TIMES TO SEE THAT THEY HAVE PROPER ATTENTION. EVIDENCE THE FOLLOWING STATEMENTS RELATIVE TO THE MERITS OF THE DIESEL ENGINE WERE MADE BY DIESEL OWNERS AND OPERATORS IN LETTERS WHICH THEY WROTE AT THE SOLICITATION OF PROSPECTIVE PURCHASERS OF POWER WHO WERE CONDUCTING THEIR OWN INVESTIGATIONS. THE STATEMENTS ARE CLASSIFIED UNDER FIFTEEN HEADINGS, VIZ.: ECONOMY, RELIABILITY, MAINTENANCE, REGULATION, OPERATION, LONG NON-STOP OPERATION, PARALLEL OPERATION AND INTERCHANGE OF CURRENT, OVERLOAD CAPACITY, CONSTRUCTION, REPAIRS, ATTENDANCE, MUNICIPAL INSTALLATION, DIESEL VERSUS STEAM AND WATER POWER, OUR CUSTOMERS RE-ORDER, SATISFACTION. ECONOMY "Our lubrication for two engines for 1911 was $472.75, and our cost per K.W., including repairs, fuel and lubrication, was $0.00253." They operate two 225 B.H.P engines. "As to comparative cost of operation, we figure that all things considered, we are operating for about 25 per cent, of what it would cost us to do the same work with steam. We figured that we could afford to junk our engines once every six years and come out better than even. "We have had one in use now upwards of seven years. It has given perfect satisfaction in every respect. The cost of repairs have been nominal, much less we believe than with a steam engine for the same length of time, and it has never been out of order except in one instance, where we were without its use for a few hours. The economy of operation of this engine is remarkable. We run our plant nine hours per day and we use ^ anywhere from 63 to 70 gallons of oil per day, and our average load is fully 100 HP." "We also find the fuel consumption to be almost in direct proportion to the work done; this, and the fact that there are no stand-by losses with this engine, have proved to be very important in our plant, as our load is a varying one and the peak load of short duration." "Our average running record for these engines, under all load conditions and averaged up by the month, is from 9£ K.W. > to 1 0 K.W. of electricity at the switchboard for every gallon of fuel oil consumed." "Our Chief Engineer states that the cost per H.P. per hour to operate the engines is about 2.07 mills. This is based on the price of Gas Oil at .0245 per gallon." "We clean the interior of the engines about twice a year and the work is done in the intervals when the engine would be shut down anyway. They require a little more careful ^ attendance than a steam engine and perhaps a little more work to keep up, but we do not employ any more than we would have to operate the same number of steam units. The service is as reliable and satisfactory and our fuel cost is about 80 per cent, less than to develop the same horse-power with steam. For our use the Diesel has proven a complete success." "Our experience with these engines, under such long service, enables us to know them very thoroughly. Their regulation is fine; they are safe and reliable; the uniform efficiency and unvarying economy in the use of fuel oil gives them an excellent endorsement in this important factor." "The Diesels have given us very reliable and satisfactory service at an efficiency that is remarkable. We are highly pleased with them. The fuel consumption of the engines has never at any time exceeded the guarantee of the Company, and for our conditions we have saved about 85 per cent, of the cost of fuel over what our fuel would have been, using steam." "We certainly appreciate the reliability and economy of these engines. The fuel consumption being almost in direct proportion to the power delivered, thus enabling us to pull through our light load season with a profit, which we are certain could never have been accomplished with a steam plant." " Both engines are directly connected to alternating current generators from which we operate all pumps, air compressor, ice hoist and ice machine with motors. This gives a very flexible outfit, as we can operate installations in the plant with either or both engines as the case may require. We also furnish all city and commercial lights for the town and find that the engines come well within the guarantee of builders. We find that the engines are almost as efficient at half load as at full load so the fuel bill is in proportion to the power delivered." RELIABILITY "As you state, the fuel economy is conceded and we find in our experience that their reliability compares very favorably with other types of power. While we would not like to guarantee that any engine would give absolutely continual service, we feel that our experience is in favor of the oil engine in this respect, and if we were in your position would install them in preference to other power." "In our plant we have two of these engines, one of 225 H.P. and one of 1 70 H.P. We have never had any shut-down due to any fault of the engine, and as to our economy, they certainly have been the means of putting this plant on its feet." for either a Diesel or Oil Engine and asked you which you found to be the most reliable and gave the least trouble. We are in receipt of your wire stating that the Diesel was the most reliable and gave the least trouble, and was the least expensive to maintain. Please accept our thanks for your prompt reply. We closed a contract with the Diesel Engine Company for two of their 225 H.P. Engines to operate our mill. We were more favorably impressed with their engine from the start." "This plant has to operate all the time without shut-downs, except by accidents, which are extremely rare, as it not only supplies the entire commercial public lighting service of this city, but supplies electric power for the local manufacturing and industrial undertakings of a large scale — a large majority of which have no other source of power." "We have experienced no inconvenience or delay from any failure on the part of these engines. I do not hesitate in recommending them to anyone for any class of service whatsoever, provided, however, that they do not expect the engine to pull more than its rated H.P. We have, however, at times run our engines over-loaded, but I do not consider such operation good practice. The only precaution I would suggest, is to have a firstclass engineer in charge of the Diesel Engine, and this however, I think is applicable to all engines." MAINTENANCE "As regards breakage, it has been very slight in our plant, having never experienced a shut-down on account of any fault of the engine. It is our practice to use only one man on a shift, although the Chief Engineer who has other duties is about the plant more or less during the day time. And when taking up bearings, etc, a helper from another part of the plant is called to assist." "We have experienced very little difficulty in keeping these engines in good operative condition and the writer being a practical engineer had rather take care of the Diesel than steam engines. Our experience has been that the upkeep of these engines is nothing out of the ordinary." "Our maintenance cost has been $30.00 to $35.00 per engine per year and we have never had to renew any large parts on the engine, only piston rings, needle valves, springs and such small parts. Neither engine has even broken a valve spring for 1 8 months." "The upkeep of these engines we find to be only a very little more than that of a first-class steam equipment, while the economy is far superior, costing less than half that of steam." "In our opinion these engines are as reliable as the steam engine and we have experienced no unnecessary delays in service due to their failure. Our properties have been operating a Diesel plant at Sherman, Texas, for about seven years, and the first engines installed there are now doing as good service as new ones. The upkeep of the old engines last year in that plant amounted to less than 2 per cent, of the original cost." "In a report from the office of the City Clerk of a city in the State of Wisconsin, we find this item: 'Repairs on engines, average for 5 years, $125.00.' This plant operates three Diesel Engines." REGULATION "The engines are used for driving three phase alternators for city lighting and power work and we find that they develop their rated H.P. to indicating instruments on the switchboards, and at no time have they exceeded the fuel consumption stated by the manufacturers. The speed regulation is good and the service reliable, in the years that we have had the engines. The engines need somewhat more careful attention than is usually given a steam engine, but there is no reason why an attendant who is even reasonably diligent can not operate the engines without trouble. "You ask — 'Is the regulation as good as that of the ordinary Corliss Engine?' Yes, we consider it fully as good. The engines regulate entirely automatically, no throttling, but simply by a sensitive governor which varies the fuel supply to meet the exact load and speed requirements." "They are also very regular in speed, being perfectly adaptable to the operation of electric generators — for which purpose they are used in this plant, in connection with a number of steam engines." "When the last Diesel was installed, an extra foundation was built ready for another. The Diesel regulation also is excellent, and as for stopping from sudden breakage of its parts, it certainly will stop if things are not right, which is not to its discredit, but it is as reliable as good steam practice in every day service. Because the Diesel Engine embraces so many time saving advantages, is so safe to run and in many ways quite simple, it sometimes suffers from neglect, but if it is in good condition it will deliver its rated horse-power easily." "As to variations in motor load, they are considerable, especially when power and lighting lap, but we find the Diesels just as quick to respond as the steam engines. Roughly speaking, the load factor of the Diesels is about 75 per cent, with quite wide extremes during a 24-hour run according to demands, and they take up their full rating without apparent effort under proper operating conditions. "Our Diesel engines carry the bulk of our load, though we have five steam engines which fill in on peak loads and extra service as required. All of our engines are directly connected to generators and the long runs are considerable, as the plant operates all the time, and, aside from a heavy commercial lighting load, has a connected load of about 1 100 electric motors in the local factories, in addition to the street lighting service." "Our first engine was installed in February, 1 906, and has been in operation ever since, running nights only. We have this year completed the installation of the second unit of 225 H.P. and believe that our new engine will fully come up to the excellent standard of service which the first one has given us." "Our Diesel engine handles this Ice Compressor, which is of 20 ton capacity, and in addition carries an electric load of about 300 amperes at 220 volts. We are satisfied that the engine is developing its full rated H.P. and the speed regulation for the 24 hours is so perfect as to procure the very best results from the Ice Machine." "Since that time, some eighteen months, we have depended absolutely on one engine to furnish light and power on a 24hour schedule, allowing a weekly shut-down of about five hours ested in the engine, but they would only give us a guarantee of 36 hours continuous running. It would take that long for the combustion chamber to fill with carbon and then the engine would have to be shut down and this chamber replaced with a clean one." "From our experience with these engines, we can recommend them for the service of which you speak. We have in cases of necessity, run one of these engines six weeks continually without ever stopping it, although this is not a good policy with any engine, as they should be shut down and examined once a week at least." INTERCHANGE OF CURRENT "Replying to your inquiry with reference to Diesel engines, have to say that on January 13, 1911, we started our Diesel Engines Nos. 293 and 294, which are three cylinder 1 6 inches by 24 inches direct connected to General Electric Company, three phase alternators. We have had no trouble even at the first trial to parallel these generators nor have we had any trouble at any time since then in putting them in parallel, and as to interchange of current between machines, it all depends upon the management of the engines. If furnished fair fuel and valves are kept in proper condition the interchange of current is negligible, and I consider the parallel operation of the Diesel thoroughly established and successful." "Replying to yours of the 12th inst., with reference to Diesel engines ; beg to advise you that we are at present operating three of the 250 HP. units directly connected to 187K.V.A., 60 cycle, 2 phase alternators, running at 1 64 revolutions per minute. We are operating these units in parallel and are getting most satisfactory results from same." "Our small engine has been operating at an overload much of the time for the past year and for this reason we have purchased additional (Diesel) equipment." "The writer some years ago had charge of a plant which was equipped with Diesel engines, direct connected to generator, and it was our practice there to carry 150 K.W., on the switchboard, with the 225 H.P. engine when it was carrying its own compressor, although at times we were obliged to carry as high as 190K.W." "When building the foundation for the engine the management did not think it necessary to follow the plans, but followed their own ideas. Instead of excavating to solid rock, they were satisfied to build the foundation on rotten surface rock. The foundation was made of concrete. Sometime after starting the engine, same was found to be in motion and the concrete foundation also, wobbling up and down like on a pivot. This increased with time to pretty near an inch and brought the engine out of line with air compressor. The 1 70 H.P. engine, weighing about 34,000 pounds, caused a pressure and vibration in the rotten rock underneath, whereby same was disrupted and crushed. This mistake we have now corrected at an expense of over $500.00, when it would not have cost more than $50.00 if the plans had been followed. It is a wonder to us here that the engine, with all its fine mechanism, did not fall to pieces. We have had enough of steam and would not trade our Diesel for all the steam engines there are." "The engines are well built and are very massive in construction, and after six years of continuous work our oldest engine is still giving perfect satisfaction. They wear well and we do not find that the cost of upkeep amounts to more than that of any first-class steam engine." REPAIRS "We have had one in use now seven years and it has been perfectly satisfactory in every respect. It requires scarcely no attention whatever, and our repair bills or expenditures for new parts have been very small indeed and we have not been without the use of the engine any hour when it was required." "It is rather difficult to give you an approximate yearly repair cost as this has varied with us according to the work done and parts replaced. Last year our repairs did not foot up to $50.00, but a year ago were over $300.00. Even if an unexpected accident should make the repair cost exceedingly high, the low cost of operation will make you the gainer in the long run." "We do not find that it requires an expert to operate these machines but we do advise that care should be taken in selecting a man of ordinary intelligence, who is careful, trustworthy and faithful." "There is no reason why one man should not operate two engines with their generators and the switchboard, that is while running. Of course when there is adjustment, cleaning or repairs to be done more help will be necessary. There are no jobs about starting or running the engine that one man cannot do." "Will state that we think the best recommendation that we can give them is the fact that we are now installing our third unit after having one in use for nearly five years. In the engine room we have two assistant engineers and one chief. It is their duty to look out for the machinery of the electrical plant as well as a 20 ton ice plant, which we also operate. We are now increasing the ice plant to a 40 ton output and the same crew will be able to care for it. One man runs the whole outfit at night." "It has been my experience that, with the great economy of these engines, we can well afford to pay the price for a good man; we are then taking no chance of a cheap man destroying a high priced machine, and, in the end, we are way ahead of the game over a steam driven plant." "You should have an engineer of some intelligence to take care of the engines and keep them up, the same as with any firstclass steam engine, but, after once started, the engines are almost automatic, requiring only an attendant to watch them and see that they get proper lubrication. We do not find that their upkeep is any greater than a steam plant. Of course, engines in duplicate guard against any shut-down in case of accident, but we ran one unit for more than two years and are satisfied that it gave as good, if not better, service than any single unit steam plant in the state operating continuously. On one occasion we ran the engine six weeks, day and night, without stopping once." MUNICIPAL INSTALLATION * * * This is an actual monthly report of the electric light and waterworks of this city, showing a cost of 8 mills per K. W. hour on the switchboard. The waterworks pumps are motor driven in duplicate. We sell commercial service enough to make the street lighting and water service free to the city." And again: "***This plant pays. Come and see us, we like to show what we have. The above is an actual report of the total cost of operating the water and lighting plant of this city with Diesel engines, which is approximately $28.00 per lamp year for 80 arc lamps, with 1 46,000,000 gallons pumpage gratis." "In our opinion Municipal Ownership of the Public Utilities, particularly the lighting system in this case, is the best possible solution of the problem. But a short time ago a proposition was made in the Village by a corporation, to purchase the Municipal Lighting Plant, but on being placed before the people was beat nearly two to one. A year later the proposition was brought up for additional power in the Municipal System and was carried by a vote of about 200 to 5. This is the best testimonial which we can give for the Municipal Ownership. You can easily see that this is what we would advise." "To argue these matters in a letter is almost impossible and I would therefore advise you to have your committee come here and look over our plant and see our Diesel engine. 1 think it would be more profitable for your city to install a Diesel engine and have a plant of your own." "Now as to our plant; it was built in 1892 and will complete a continuous record of success next month, covering a period of 20 years. It represents an investment of about $200,000, of which all but $22,500 has been paid from profits, since commercial lighting and power were added to the original street-lighting plant in 1898, and at the present rate the entire debt will be wiped out within a year. Our rates have always been the lowest in this state, and nearly all the factories of this city are operated by the power of this plant — about 1 200 connected H.P. in motors — not to mention a heavy lighting load. As to fuller details, we take pleasure in sending you our last annual report of nearly a year ago under separate cover, and trust that we will thus supply you with the information desired." This plant installed its first Diesel in 1905 and has added no additional steam equipment since then. DIESEL vs. STEAM AND WATER POWER "Another great advantage of the Diesel engine over steam is that we do not have to wait half a day or more for results ; we can start our engine in less than three minutes, and pull the load from the start. As to maintenance, we can find no reason why the expense should be very great. Our expenses with the old steam engine were numerous and heavy. The engine is durable — there is no question about that." "You say you are now operating steam engines and think of buying a new engine. We have gone through the same ordeal and hesitated and figured and figured and hesitated and studied up on different kinds of engines, so I know how you feel. We would not here go back to the old steam or have any other power next to our water-power than the Diesel engine." "Right here I would like to say that about the time of my taking charge of this plant, the financial condition of the Company was such that if we had a steam plant we could never have pulled through, and, when in need of more power, we will install another Diesel." "We have found the Diesel engine remarkably efficient in the use of fuel oil, having placed our first one in service in 1905, another in 1 907 and the last one in 1910, with a foundation ready for still another, so that our experience has been considerable. We also have steam engines in service, but have not added to our steam equipment since the first Diesel was installed." "After running this engine for two years, our business had increased so that it was necessary to purchase a second engine of the same size, and this Spring we installed a third unit of 225 H.P. When installing the first engine we discarded a steam outfit, and the fact that we have continued to buy Diesel engines as our business increased, should convince you of our faith in them." "We will take our Diesel in preference to steam every time and if you get the engines manufactured by the Busch-Sulzer Bros.-Diesel Engine Co., St. Louis, we know that they will deliver the goods every time if you take care of them. You can also rest assured that these engines will fulfill every guarantee made by their builders." "We have been using Diesel engines in our plant for the past six years and we are well pleased with the service they have given. Our first engine was of 1 70 H.P. and was the only unit we had for three years. At the end of that time business had increased to such an extent that we found it necessary to duplicate our outfit with another 1 70 H.P. unit. We continued to grow, and last year installed the third unit of 225 H.P." A superintendent writes to his management: "The present engine is doing very good work, is not giving any trouble at all since we fixed up the starting cam, four months ago, and I still believe the Diesel unit is the most reliable, as well as the most economical outfit, that ever generated current. I am decidedly of the opinion that the installation of another engine is a step in the right direction and will effect large economies in our operation." "When our load became so great that we were unable to handle it with an engine of this size, we immediately installed a second machine of 225 H.P., which has been giving excellent service since March 1 st last, when it was placed in service. This fact answers your question as to whether we would buy Diesel "As to our experience with the Diesel engine, we have much to commend and very little to say of a negative nature regarding it; the fact that we have purchased three of them in succession and have a foundation built for another, speaks of what our faith has been in them." "We have now ordered a third and larger engine which will be installed next February, and while we are building we are making our power house large enough to accommodate the fourth unit when it is needed. We think they are the greatest thing out." From telegram : "Sixty K.W. generator over six years, at 1 0 hours full load and over, fuel consumption less than Diesel Company's guarantee. Besides two engines seventy-five each, seven years, we have one two hundred twenty-five, running five months very satisfactorily." SATISFACTION Every extract exhibited in EVIDENCE testifies to the satisfaction Diesel users are getting from their engines — hut here are some more: "We further have this to say — that the Diesel Oil Engine has made it possible for this plant to succeed. Our experience with this engine compels us to speak very highly of it, and we do not hesitate to say that we believe it to be the most economical and reliable engine on the market today." a conversation a few days ago, that the results obtained from the Diesel engine were away beyond his highest expectations, and that he intended installing them in several of the electrical plants which he owns." "We have had enough of steam and would not trade our Diesel for all the steam engines there are. You can tell the people of Belleville that we believe the Diesel engine to be the best and cheapest power produced in the world today, as I see from your letter that your intention is to install a municipal plant. Corporations have tried to buy our plant, but we are glad that we were not ensnared." "As to your natural inquiry — 'Is the engine entirely satisfactory?'— we will simply say that our reason for adopting it was because we were looking for something more satisfactory than steam, although we already had an excellent steam plant. Now we are looking for something better than the Diesel and if there is anything that will beat it in fuel economy, speed regulation, safety and many other essential features, we would like to know where to find it." "These engines are both 3-cylinder engines of the 4-cycle type, one of 170 and one of 225 B.H.P., which have been in operation for the last seven years, and are still giving perfect satisfaction. We are highly pleased with these engines, both as to reliability and economy; in fact in every respect. We can certainly recommend this engine very highly and suggest, before purchasing your prime mover you write to the makers of this engine for detailed information." POWER FACTOR On an alternating-current electric circuit, the product of the readings obtained simultaneously from a volt-meter and an ammeter indicating the apparent power, may be more than the reading obtained at the same time on a wattmeter which indicates the true power. The power factor is the ratio of the wattmeter reading to the product of the voltmeter and ammeter readings and is never greater than one. In any case the power factor is the ratio of true power to apparent power. This ratio is usually expressed in percent and can never be greater than 1 00 per cent. If true power is expressed in kilowatts (kw.) and apparent power expressed as the product of kilovolt amperes (kva.), then the following formula can be used: For estimating purposes, the following may be assumed as average values of power factors in their respective circuits: Incandescent lighting load, no motors, 95 per cent.; Incandescent lighting and induction motors, 85 per cent; induction motors only, 80 per cent; arc lamps 70 per cent The true power, in kw., equals the average volts between line terminals, multiplied by the average amperes line current, multiplied by the power factor (expressed as a decimal fraction), divided by 1 000, and multiplied by : 1.732 for three phase Although the current, equivalent to the difference between the apparent and true powers, imposes practically no load upon the prime mover (engine); this, so called "wattless current," produces in the generator a heating greater than that due to the equivalent true power, and the generator must, therefore, be proportioned to take care of this current without over-heating. MINERAL OILS The characteristics of Crude Mineral Oils and their products vary greatly in different localities; but the following general information may be of interest. "Asphaltum," as applied to a constituent of some mineral oils, is a most indefinite term, as its definition and the method of its determination have not been standardized. Until some standard is agreed upon, it would be better to compare "Asphaltum base oils," for use in Diesel engines, on the basis of the percentage of weight remaining after reduction to constant weight in a closed furnace at a definite temperature, say 300 deg. Centigrade. The Beaume hydrometer is an instrument for determining the density of liquids. The graduations are in numbers, termed "degrees", of an arbitrary scale. CONCRETE FOUNDATIONS Concrete for foundations to be 1 part Portland Cement, 2i parts clean, sharp sand, and 5 parts clean, broken stone. Stone to pass through a 2-inch ring. To be mixed wet, and rammed every 8-inch depth until water appears on surface. Templets to be made open to permit ramming. Concrete must not be allowed to set hard before other concrete is placed on it, otherwise sound bonding between portions cannot be had. Around each fundation bolt a wooden box, 4 inches square at lower end, with increasing taper of i-inch per foot, and at least 4 feet long, must be placed. As the concrete sets boxes to be rapped loose and withdrawn. If preferred, 4-inch diameter galvanized spouting may be used and left in foundation, projecting not more than J-inch above concrete. Grouting to be equal parts Portland Cement and clean sand, mixed wet enough to flow readily. Grouting must fill spaces around foundation bolts. LEATHER BELTING The size of leather belting, suitable for any given work, depends upon so many factors that it is practically impossible to prepare a simple table which will meet all requirements. The table given below, however, is safe for all ordinary conditions. The thickness of belt assumed is: Single Belt — 3/ie-in. minimum. Double belt — n/32-in. minimum. Triple Belt — 1/2 -in. minimum. ately corrected. The most satisfactory belt speed, all things considered, is between 60 and 70 feet per second, although the most economical speed is about 1 00 feet per second, which is, however, too high for ordinary iron pulleys. The distance between pulley centers should vary with the thickness and width of the belt, and the pulley ratio. No definite rules for this have ever been formulated, and there is considerable diversity of opinion. It will, however, be found advisable to make the distance between pulley centers NOT LESS THAN proportionate to the following table, for a pulley ratio of 1 to 1 . For a pulley ratio of 6 to 1 this distance should be increased 20 per cent., and proportionately between the 1 to 1 and the 6 to 1 ratios. In ordering a belt it is well to inform the belt manufacturer of the following conditions, and to require him to furnish a guarantee that the belt will satisfactorily perform the required work under the stated conditions: TABLE FOR EQUALIZING PIPES The size of main pipe is given in the column at the left. The number of branches is given in the line on top, and the proper size of branches is given in the body of the table on the line of each main and beneath the desired number of branches. In commercial sizes the nominal 1 i-inch pipe is generally over-size; often as large as 11. It is safe to call it 1 .3 inches, and it is so figured in the table. Exact sizes are given for branch pipes. The designer of the pipe system can thus better select the commercial sizes to be used. 0.11 34 cubic feet. One foot head of water, equals 0.4335 pounds per square inch. One pound per square inch equals 2.307 feet head of water. One foot head of water equals 0.8826 inches of mercury. One inch column of mercury equals 1 . 1 33 feet of head of water.	18,862	common-pile/pre_1929_books_filtered	dieselengine00buscrich	public_library	public_library_1929_dolma-0018.json.gz:172	https://archive.org/download/dieselengine00buscrich/dieselengine00buscrich_djvu.txt
wgim-VGGwDy4JVhN	Macroeconomics	37 Changes in Equilibrium Learning Objectives - Create a graph that illustrates equilibrium price and quantity - Predict how economic conditions cause a change in supply, demand, and equilibrium (using the four-step process) Finding Equilibrium using the Four-Step Process We know that equilibrium is the place where the supply and demand curves intersect, or the point where buyers want to buy the same amount that sellers want to sell. Let’s take a closer look at how to find the equilibrium point using the four-step process. These steps explain how to first, draw the demand a supply curves on a graph and find the equilibrium. Next, consider how an economic change (e.g. a natural disaster, a change in production technology, a change in tastes and preferences, income, etc.) might affect supply or demand, then make adjustments to the graph to identify the new equilibrium point. Step 1. Draw demand and supply curves showing the market before the economic change took place. Think about the shift variables for demand, and the shift variables for supply. Using this diagram, find the initial equilibrium values for price and quantity. Step 2. Decide whether the economic change being analyzed affects demand or supply. In other words, does the event refer to something in the list of demand shift variables or supply shift variables? Step 3. Determine whether the effect on demand or supply causes the curve to shift to the right or to the left, and sketch the new demand or supply curve on the diagram. In other words, does the event increase or decrease the amount consumers want to buy or the amount producers want to sell? Step 4. Identify the new equilibrium, and then compare the original equilibrium price and quantity to the new equilibrium price and quantity. Let’s consider one example that involves a shift in supply and one that involves a shift in demand. Then we will consider an example where both supply and demand shift. Exercise 1: Good Weather for Salmon Fishing Let’s suppose that during the summer of 2015, weather conditions were excellent for commercial salmon fishing off the California coast. Heavy rains meant higher than normal levels of water in the rivers, which helps the salmon to breed. Slightly cooler ocean temperatures stimulated the growth of plankton, the microscopic organisms at the bottom of the ocean food chain, providing everything in the ocean with a hearty food supply. The ocean stayed calm during fishing season, so commercial fishing operations did not lose many days to bad weather. How did these climate conditions affect the quantity and price of salmon? Let’s consider this situation using the four-step process and the data below. \| Table 1. Salmon Fishing \| \|\|\| \|---\|---\|---\|---\| \| Price per Pound \| Quantity Supplied in 2014 \| Quantity Supplied in 2015 \| Quantity Demanded \| \| $2.00 \| 80 \| 400 \| 840 \| \| $2.25 \| 120 \| 480 \| 680 \| \| $2.50 \| 160 \| 550 \| 550 \| \| $2.75 \| 200 \| 600 \| 450 \| \| $3.00 \| 230 \| 640 \| 350 \| \| $3.25 \| 250 \| 670 \| 250 \| \| $3.50 \| 270 \| 700 \| 200 \| Let’s walk through the four steps together using this example, and see how the graph changes. Use the interactive activity below by clicking on the arrows at the bottom of the activity to navigate through the steps. Click here for a text-only version of the activity. In short, good weather conditions increased supply of the California commercial salmon. The result was a higher equilibrium quantity of salmon bought and sold in the market at a lower price. Exercise 2: Newspapers and the Internet According to the Pew Research Center for People and the Press, more and more people, especially younger people, are getting their news from online and digital sources. The majority of U.S. adults now own smartphones or tablets, and most of those Americans say they use them in part to get the news. From 2004 to 2012, the share of Americans who reported getting their news from digital sources increased from 24 percent to 39 percent. How has this trend affected consumption of print news media and radio and television news? Figure 1 and the text below illustrate the four-step analysis used to answer this question. Step 1. Draw a demand and supply model to think about what the market looked like before the event. The demand curve D0 and the supply curve S0 show the original relationships. In this case, the curves are drawn without specific numbers on the price and quantity axis. Step 2. Did the change described affect supply or demand? Show Answer A change in tastes, from traditional news sources (print, radio, and television) to digital sources, caused a change in demand for the former. Step 3. Was the effect on demand positive or negative? Show Answer A shift to digital news sources will tend to mean a lower quantity demanded of traditional news sources at every given price, causing the demand curve for print and other traditional news sources to shift to the left, from D0 to D1. Step 4. Compare the new equilibrium price and quantity to the original equilibrium price. Show Answer The new equilibrium (E1) occurs at a lower quantity and a lower price than the original equilibrium (E0). The decline in print news reading predates 2004. Print newspaper circulation peaked in 1973 and has declined since then due to competition from television and radio news. In 1991, 55 percent of Americans indicated that they got their news from print sources, while only 29 percent did so in 2012. Radio news has followed a similar path in recent decades, with the share of Americans getting their news from radio declining from 54 percent in 1991 to 33 percent in 2012. Television news has held its own during the last fifteen years, with the market share staying in the mid to upper fifties. What does this suggest for the future, given that two-thirds of Americans under thirty years old say they don’t get their news from television at all? Try It	1,328	common-pile/pressbooks_filtered	https://library.achievingthedream.org/sacmacroeconomics/chapter/changes-in-equilibrium/	pressbooks	pressbooks-0000.json.gz:81466	https://library.achievingthedream.org/sacmacroeconomics/chapter/changes-in-equilibrium/
FDPu2ev_DXJ3HMMJ	Introduction to College Research	Conclusion This chapter outlined how your library organizes materials and provided guidance on how you can search for resources that the library physically owns. Even though there are standards such as the Dewey Decimal System that libraries use to organize their materials, you may find that your college library has some unique and different ways of providing access to their physical collection. So, explore your library shelves and ask a librarian if you’re unsure how to find an item. After familiarizing yourself with the library, it will become much easier to access those resources that you will need to complete your course assignments successfully. Sources Image: “Rainbow Frequency” by Ricardo Gomez Angel is in the Public Domain, CC0	153	common-pile/pressbooks_filtered	https://opentextbooks.uregina.ca/introtocollegeresearch/chapter/conclusion-library-materials/	pressbooks	pressbooks-0000.json.gz:9762	https://opentextbooks.uregina.ca/introtocollegeresearch/chapter/conclusion-library-materials/
B6gCg-Wj837j7tmi	Cost of railroad transportation, railroad accounts, and governmental regulation of railroad tariffs / by Albert Fink ...	The following table may be of some interest, showing the number of tons of freight carried over the Main Stem and branches from 1865-66 to 1871-72, and over the Main Stem, branches, and Memphis Line from 1872-73 to 1873-74; also the gross revenue, cost, and net revenue per ton per mile, and .the percentage of net to gross earnings: PERCENTAGE OF NET TO GROSS EARNINGS NO CRITERION OF ECONOMY. The information contained in this table illustrates the error which is often committed in using the percentage of the net to the gross earnings as a criterion of the economy with which a railroad is operated. In 1865-66 the net freight earnings were 43.3 per cent and in 1873-74 only 33.1 per cent of the gross earnings. It would be erroneous to conclude from this that the road was operated with less economy in the past year. It will be observed that the gross earnings per ton-mile in 1865 were 5.37 cents; in 1874 they were only 2. 11 cents. Had the gross earnings per ton-mile in 1874 been the same as in 1865, the net earnings would have been 74 per cent instead of 33.1 per cent of the gross earnings. It would, however, be equally erroneous to conclude that in 1865 less economy was exercised in the operation of the road than in 1874. The differences are accounted for by other reasons. In 1865 the bulk of the freight was local, carried over short distances of the road ; since that time it has become mainly through business, which goes over the whole length of the road. The latter is transacted at less expense. Since 1865 the amount of business on the Main Stem has more than trebled. This increase causes a reduction in the operating expenses. There is a certain class of operating expenditures that do not increase with the amount of business; they are fixed expenses which have to be incurred whether a small or a large business is transacted. It follows that when only one third of the number of tons of freight were moved in 1865 as compared with 1874, the cost per ton-mile for this class of expenditures would be three times greater than in 1874. In order to make a just comparison between the economy of operation in two different years, it becomes necessary to take into consideration the amount as well as the character of the business, whether through or local, and also the cost of labor and material prevailing during these years. But even then the comparison gives no correct results. We have further to discriminate between the expenditures made during one year due to that year's operation, and the RAILROAD TRANSPORTATION. 5 expenditures made due to the operation of former years. The expenditures on account of renewal of rails, cross-ties, bridges, rolling-stock, etc., do not always, I may say hardly ever, represent the exact cost of making good the wear and tear caused by the business of the year in which they were incurred. For the first few years of the operation of a new road, for example, the expenditures on the accounts just named would be very small, and afterward they must become correspondingly large. If we therefore fail to ascertain correctly the operating expenses for each year, the net earnings as shown in the annual reports for any one year do not form a proper basis for estimating the value of railroad property. The results of some years' operations lead to hope and others to disappointment, either of which may not be justified by the facts. To illustrate this subject further, the following estimate of the expenditures during the year on the Main Stem of the Louisville & Nashville Railroad which are not chargeable to last year's business is submitted. For Repairs of Iron Rails. — The gross ton-miles moved over the Main Stem during the year were 307,483,718. Taking the average number of tons of iron worn out by 100,000 gross ton-miles, as shown in Table XIX (0.95 tons), the amount of iron worn out by the last year's business was 2,921 tons. The actual cost of renewing this iron will be, including labor. This estimate is based upon the average wear of iron. But there are now 72 miles of steel rails on the Main Stem: estimating their wear at four times that of iron and the cost ^20 per ton more, we find that instead of 1,094 tons of iron only 273.5 tons of steel rails were worn out. The difference in cost of renewal amounts to For Repairs of Cross-ties. — The cost of replacing cross -ties per year on the Main Stem since the road was first built has been, as per statement XX, $257.11 per mile. For Bridge Repairs. — The average cost of bridge repairs for the last eight years has been $141.24 per mile per year. During the past year the expenditures on this account were unusually heavy, $250.26 per mile. The condition of the bridges is at present such that the cost of repairs will hereafter be much less than the average for the last eight years; but estimating it to be the same, the expenses incurred last year were greater than the average, 185 X (250.26 — 141.24) = $20,168.70, and the total amount for iron ties and bridges not chargeable to last year's operation is $111,088.87. This large amount of money expended during the last year (as well as similar amounts in the two preceding years) was due to the operation of former years. In the coming year, on account of the excellent condition in which the road now is, these expenditures can be reduced at least to the average, if not below it, and large reductions will be made on account of the reduced wages and cost of material, so that we may confidently expect larger net earnings. It is fortunate that the heavy expenditure required to make good the wear of former years had been incurred before the effects of the panic of 1873 upon the business of the road were felt. In the near future we must expect the business of the company to be comparatively light. Fortunately no heavy expenditures will have to be made. It will appear from what has been said above that it is impossible to judge of the economy of railroad operation from the annual reports of a railroad company for any one year without estimating the expenditures that are really due to each year's operation. Large net earnings may be shown in one and much smaller in another year, yet the road may have been operated with the same degree of economy in both years. To make the annual reports of a railroad company of value, the accounts of the company should be so kept as to show the expenses due to that year's operation. For that purpose an account should be opened which might be called "renewal account," and to which should be credited or charged the difference between the estimated cost of the operating expenses due to the year's work and the operating expenses actually incurred during the year. This account would have to be credited when the actual cost is less and charged when it is more than the estimated cost. The balance of this account at the end of the year will be a proper charge against the revenue account. It is true that these balances can only be estimated ; but as railroad tracks, ties, bridges, etc., are never made entirely new again, there always will be a certain amount charged to this renewal account which will represent the depreciation of the property, and the owner of the property will have a clearer idea of its value than if no such account had been kept, although it may not be entirely correct. I have purposely pointed out the difficulties encountered in forming correct estimates of the economy of railroad operations, because, on account of the effects of the general stagnation in business upon the value of railroad property, greater interest is felt in this subject than heretofore. It is surprising to find that so deceptive a criterion as the percentage of operating expenses to gross revenue is still used by many intelligent persons (among whom are not only stockholders, but bankers and financiers) to judge of the economy of railroad operations. In addition to what has been said as to the impossibility of basing any judgment upon such data, the following table is submitted, which shows the percentage of operating expenses to gross earnings, also the revenue and cost per ton-mile and per passenger per mile on the several roads operated by the Louisville & Nashville Railroad during the year 1873-74: These seven roads from which the above results are obtained are under the same management, and whatever may be the degree of economy exercised in their operation, it is the same on all; yet the proportion of operating expenses to gross earnings vary from 63.8 to 101.4 per centjthe cost per ton-mile of freight from 1.32 to 8.23 cents, and per passenger from 2.5 to 4.34 cents. TABLES OF ANNUAL REPORT. If the percentage of operating expenses to net earnings, or the cost of one ton of freight or one passenger transported one mile, can not be used as an absolute measure of economy, or even as a measure of comparison, and we have seen it can not, the question arises. What is the proper course to pursue in ascertaining whether a railroad is economically operated or not? To this the answer must be given that the only mode of ascertaining this fact thoroughly is to make an examination of each item of expenditure incurred in the operation of a railroad, and see whether this has been reduced to a minimum and the service rendered for it to a maximum. To make this investigation requires of course a thorough and practical knowledge of railroad operations, of the cost of material and labor, of the quality of the same, and of the best results that can be obtained therefrom. But even that knowledge would be of little avail unless the accounts of the operating expenditures of railroads are kept in such a manner as to exhibit in detail not only the expenditures, but also the amount of work performed for each item of expenditures. In the annual reports of this company I have endeavored, as far as practicable, to present the accounts of the expenditures in such a manner and for the purpose set forth. I propose to call special attention to the information contained in this report, because of the great interest which is now manifested in the subject of railroad transportation, and the necessity that both the owners of railroad property and the people should possess correct information regarding it. =^= These tables are published in the Annual Report of the Louisville & Nashville Railroad Company for 1873-74. The "Headings of Accounts" of tables II and III are printed on page 47 in this pamphlet, and should be referred to by the reader instead of these tables. the operating expenses and statistical information regarding the same ; the second class, from XXVI to XLV, contains statements of the amount and character of the freight and passenger traffic, with the revenue derived therefrom. Table I contains in a condensed form, under one hundred and two heads for each road, the general results of the operation of the Main Stem and branches and leased lines, both as regards expenses and revenue. Table II contains statements of the operating expenses under seventy-seven subaccounts for each road. The total sums expended on each account are shown in this statement ; but from this no opinion can be formed as to the economy or judiciousness of the expenditure. In order to aid in analyzing the expenditures, with the view of forming such an opinion, the following tables are prepared, showing the expenditures for certain units of work performed. Table III shows the expenditures per mile of road and per trainmile. The figures in the first column designate the same accounts as are indicated by the same figures in Table II. The items i to 29 show the cost per mile of road for maintenance of roadway, buildings, general expenses, etc. ; items 30 to 74 the cost per train-mile. There are some accounts, however, for which the cost " per mile of road " or "per train-mile" can not be used as a criterion of economy, because the expenditures on these accounts are independent of the number of miles of road operated or the number of miles run by trains. For this reason it becomes necessary to present these accounts in some other manner, so that they may show the amount and character of the work done, as well as the expenditures incurred. The following tables have been prepared for that purpose. Table IV shows in detail the expenditures incurred at stations. 'J'he total amounts expended were shown in items 30 to 35, tables II and III. The number of tons of freight handled and the cost per ton at each station are shown in this table. Station expenses form a very large proportion of the operating expenses of a railroad, and when their aggregate amount is only known it is impossible to tell whether this branch of the business was conducted with economy or not. But by showing the cost per ton of freight handled a measure is obtained by which a proper check can be put upon this class of expenditures. This, however, to be of use has to be done from month to month, and for that purpose monthly statements are made out showing the cost of conducting the business at the principal stations. Table V is such a statement, showing the cost per car-load of freight forwarded from and received at Louisville for each of the following items: Labor (loading and unloading freight), clerks (receiving and delivering freight;), agents, cashiers, office-clerks, and watchmen (general expense); yardmen and switchmen; expenses of switching-engines. With close attention to the management of the business of a station for a few months the minimum cost at which freight can be handled can be readily ascertained. This being known, it requires only some clerical labor in order to obtain a check over a very im- ' portant class of expenditures, amounting on the Main Stem of this road to about 25 per cent of the total operating expenses, and of such a character that very little personal supervision can be exercised over the same. Tables VI, VII, VIII, and IX show the cost of repairs of each bridge, depot-building, shop-building, water-station, and section-house oh all the roads. The total amount of expenditures on these accounts are shown in Table II, items 15 to 19. The expenditures detailed in these tables belong to that class which can not be tested as to their economy by using the mile of road operated or the number of train-miles run over it as a measure of cost. Hence the cost of the repairs of each individual structure is shown, from which, with a knowledge of its condition at the beginning and at the end of the year, an opinion can be formed as to the judiciousness of the expenditures. The tables of course contain only the total amounts expended on each structure. When further information is desirable the books, which contain accounts in detail with each structure, must be consulted. While it is comparatively easy to trace the expenditures just named, and obtain a proper check over the same, it is more difficult to do so with another account, usually designated "road repairs." The work performed in maintaining the roadway and track is of a complicated character, and in order to establish some unit of measure of cost and work it becomes necessary to classify the expenditures according to each special character of work, and apply the proper measure to each class separately. For that purpose the general account of road repairs has been subdivided in the reports of this company as follows (the figures indicate the same accounts as those in tables II and III) : which is the proper unit of measure to be applied to cost and work. 42. The cost of refiewal of rails varies with the tonnage passed over the rails, the speed of trains, and the quality of the iron. To ascertain what should be the wear of rails under a certain usage requires careful observation during many years upon the different classes of iron in the track. The general results obtained during the last eighteen years on the Louisville & Nashville Railroad have been recorded in statement XIX, which will be referred to hereafter more fully. From this statement it appears that on the Main Stem 100,000 gross tons passed over one mile of road wore out 0.95 tons of rail (60 lbs.), while on the Memphis Branch the same gross weight wore out 1.5 tons. On the Knoxville & Bardstown branches no deduction can as yet be drawn, as there has not been sufficient wear of the iron. The rails on the Memphis Branch were of the tubular form. and proved in comparison with those on the Main Stem very inferior. By examining further the wear of each particular brand of iron under the tonnage we find that of some brands only 0.75 tons were worn out by 100,000 tons of gross weight on one mile of road, while of others 1.75 tons, showing a very great difference in the quality of iron. On account of this great inequality it is impossible to fix upon any positive measure of wear and predetermine very accurately what should be the cost per gross ton-mile or per train-mile for repairs of iron. But, using the average result obtained from the experience of many years, we may at least make approximate estimates. The most valuable use to which the information obtained by keeping accurate records of the wear of iron inay be put is to aid us in selecting the best quality of iron, to determine the best mode of manufacturing it, and to decide when it becomes advantageous to use steel rails; all of which are important questions in the economy of railroad operation, which can not be intelligently answered without such information. The amount of money involved in selecting good or inferior iron may be estimated on the Louisville & Nashville Railroad as follows: The total gross tonnage that passed over all the roads operated by this company in the past year was equal to 614,882,166 tons carried over one mile. If the whole road was laid with the best iron that we have used, there would be required per annum under this tonnage 4,611 tons of iron, and if with the most inferior iron which we have used, 10,760 tons, a difference of 6,148 tons, which at the present low price of iron, including labor of relaying — say $50 per ton — would amount to $307,400. The next item of expense incurred in keeping a road in repair is the labor of replacing rails, the cost of which can be properly measured by the number of tons of new rails laid. The same holds good approximately as regards the cost of jomt-fastenings, spikes, and the hauling of iron. If the minimum cost of these several classes of work is once ascertained by special observation, a check over a large amount of expenditure can be readily established. Renewal of cross-ties (items 11, 12, 13, tables II and III). — The average number of ties in one mile of road, the rate at which they decay per annum, the minimum cost of ties, labor of replacing, and hauling are the principal elements which determine the amount wliich should be expended per year on this account. The accounts of this company have been so kept as to exhibit all this information. The results of the experience for the last fifteen years regarding the durability of ties and the number required per annum, the cost of labor per tie, etc., have been recorded in statement XX. Adjustment of track (items i and 41, tables II and III). — In this account is charged the cost of keeping the track in i)roper adjustment as regards line and surface, and necessarily includes the cost of bedding the ties for the purpose of sustaining the rails in their proper place. The cost of this work depends upon the nature of the roadbed, the action of the weather, and the amount and character of the traffic. In order to obtain a measure of economy we have to divide this account into two parts, in accordance with the cause which makes the expenditures necessary : {a) The cost of bedding ties and adjusting track, so far as this work may be required, regardless of the extent of the use that is made of the road, depends on the character of the road-bed, the influence of climate, etc., and cost of organization for the purpose of attending to this work. passage of trains over it. The proper measure for the expenditure referred to under (a) is the "mile of road," and under {b) the number of tons passed over the track, or approximately the number of "train-miles." The cost of this work must necessarily differ on different roads. No general rule can be adopted that will apply to all roads ; yet by an observation for several years in each individual case the minimum cost per mile of road and per train-mile for each class of work may be ascertained and used as a check upon this class of expenditures. In tables II and III this account (adjustment of track) has been divided in accordance with the result obtained from observation made on this road during the last fifteen years. The cost per mile of road is shown in item i, tables II and III, and the cost per train-mile in item 41. The division of this account becomes also necessary when wc desire to ascertain the relations existing between the cost of additional tonnage passing over the road and the cost that has to be incurred 3. Cost of ditching differs with the nature of the soil, climate, and amount of rainfall. With observations extending over a number of years the minimum cost per mile of road may be approximately ascertained in each individual case, and may be used as a check on this class of expenditure. The same may be said of the cost of repairs of ballast (2), road-tools (7), repairs of hand and dump-cars (6), and general expenses of road department (9). The cost of extraordinary repairs includes the cost of repairing damage to road-bed caused by freshets, slides, etc. These are accidental causes, hence no measure can be applied to this except that based upon experience for a great number of years. This analysis of the various subaccounts which are usually comprised under one general account, called "road repairs," shows how impossible it is to apply to the general account one measure — such, for example, as the "mile of road" or "train-mile" — and use it to ascertain the economy with which the work was done, or to make comparison between different roads. The many elements of cost of different nature must be separately considered and compared. Thus we could not compare the cost of adjustment of track of a mile of road over which forty trains pass with the cost of a mile over which only one train passes without separating the expenses incurred on account of tonnage from those which are independent of the tonnage. We have now ascertained the various accounts from i to 46, tables II and III, and established proper measures that- can and should be applied to each, to determine the judiciousness of the expenditures. We will now proceed to examine the other accounts from 47 to 73. kept with each locomotive. 53. Engineers a7id firemen; 55. Conductors and brakenien. — The elements determining expenses on these accounts are the wages paid to each class of employees per day, and number of miles to be run by them constituting one day's work. The total expenses under this account should not exceed the cost per mile so ascertained, multiplied by the total number of miles run. 49 and (iT)' Oil and waste and fuel used by locomotives can be readily checked by the number of miles run. It is necessary to ascertain from direct observation the most economical results that can be secured under existing conditions, and apply it as a measure to the whole year's work. The expenses for fuel form so large a portion of the operating expenses of railroads that accurate accounts must be kept of the consumption of each engine, and these accounts must be balanced with the total amount of fuel bought. Without such check the detailed statement can not be relied upon as correct. Inventories of the fuel on hand are taken every six riionths, and all the fuel bought is fully accounted for. Table XII contains a yearly balance-sheet of fuel account, in which is shown the amount of fuel bought and consumed during the year, and for what purpose used, cost of same, etc. Table XIII. Car repairs. — The unit of comparison of this work is the number of miles run by the several classes of cars. This table contains the mileage made by each class of cars, and cost of repairs per mile. The expenditures shown in items 66-72 depend principally upon accidental causes, and no fixed measure of economy can be adopted for the same. I have now examined the several items constituting the operating expenses of the road, and in a general way pointed out the mode in which the accounts should be kept in order to enable the managers to obtain proper checks and control over the expenditures, and to aid others in the investigation of the economy with which the road has been operated. There are some additional tables attached to this report which give details of expenditure and other statistical information relating thereto, to which I will now refer. Tables XIV and XV are balance-sheets of the iron- and brassfoundry accounts, showing the amount of castings made, material bought, cost of making castings, and material and castings on hand July I, 1874. Table XVI shows the operating expenses of the steamer "Dick Johnson" on the Tennessee River. This steamer was put on the Tennessee River to secure business from that river which we could not obtain otherwise, with the view of increasing our tonnage in the direction in which it is now lightest, adding to the revenue without much additional expense. Satisfactory arrangements have been made with the E. & T. P. Co. to run in connection with our road after July ist, and from that time the company will discontinue to operate its own steamer. Table XVII shows in detail the amount expended for new rollingstock acquired during the year, and for other improvements which have increased the value of the road, and which are not properly chargeable to the operating account. The following tables contain further statistical information. Table XVIII shows the cost of road repairs per mile of road and per train-mile from the time the roads named were completed or came into the possession of this company until the pfesent day ; also the amount of new iron used during each year. Table XIX shows the cost of renewing iron on four roads since their construction ; also the number of tons of gross weight due to the passenger and freight traffic passed over the iron since it was laid. This tonnage is given in three different modes: i. The actual gross tonnage passed over the road, including switching and construction service ; 2. The gross weight of passenger and freight revenue-trains alone ; 3. The gross weight of the freight revenue-trains, and double the gross weight of the passenger revenue-trains. It is presumed, as data for comparison, that the wear of one gross ton of a passengertrain moved over the iron at double the speed of a freight-train is equal to the wear of two gross tons of a freight-train. In order to ascertain the wear of iron by the tonnage passed over it from the time the iron was new up to the present time it is necessary to take in account the depreciated condition of the iron at present and the estimated cost to make the track new again. These estimates are Table XX shows the number of cross-ties used on the various roads since their construction up to date, the cost of same, the cost of labor relaying and hauling per tie. It was also necessary to make the estimates of the number of ties required to make the road new, as the average number of ties used per year up to this time does not represent the full wear of the ties per year. CLASSIFICATION OF OPERATING EXPENSES. Before leaving this subject attention is called to the classification of accounts in tables II and III. It will be observed that the accounts are divided into three classes : I will now refer more particularly. Those in the first class are not affected by the amount of business transacted, within certain limits to Idb referred to hereafter. The roadway must be kept in good order. Cross-ties when decayed must be renewed, bridges kept in repair, and a certain organization of officers and men must be kept up, whether one or more trains are to pass over the road. bridges to be kept in repair, the nature of the soil, the climate, and many other local conditions. They will also vary with the amount of business, but only to the extent to which an increase of business requires more extensive accommodation, such as depot - buildings, side-tracks, etc., which have to be kept in repair. On a road with an established business, and having suitable accommodation for the same, considerable variation in business may take place without affecting this class of expenditures. The second class of expenditures are incurred at stations in keeping up an organized force of agents, laborers, etc., for the purpose of receiving and delivering freight, the selling of tickets, etc. One portion of these expenditures does not vary with the amount of business ; another portion does. A certain number of agents have to be employed, whether there is more or less work to be done ; but the number of persons employed to handle freight may be varied in proportion to the number of tons of freight to be handled. This whole class of expenditures, however, is entirely uninfluenced by the length that either freight or passengers are hauled, or, in other words, by the work of transportation performed. Freight or passengers may be hauled five or two hundred miles, the station expenses incurred on their account being the same. that vary with the number of trains run. On roads on which there is sufficient freight business to fill all trains that are run from one terminus of the road the amount of freight transported will be nearly in proportion to the number of freight train-miles ; and hence on such roads this third class of expenditures will be nearly in proportion to the amount of business. It is this class of expenditures alone which possesses that characteristic. On roads, however, upon which freight-trains have to be run at stated times, whether fully loaded or not, this class of expenditures does not vary with the business, but very nearly with the number of trains run. The expenditures and amount of freight transported in this case are irrelative, the cost of transporting freight being dependent entirely upon the loads as accidentally offered for transportation. To the three classes of expenditures just named, and which have been shown separately and in detail in tables II and III, must be added a fourth, not shown in these tables, but which forms a large interest on the capital invested. This class is mainly uninfluenced by the amount of work done. Only so far as an increase of business involves the necessity of additional investments for its accommodation is it influenced by the amount of business. In the consideration of the subject of the cost of railroad transportation it is of the greatest importance to discriminate between the expenditures which vary with the amount of work performed and those which are entirely independent thereof. The latter form so large a proportion of the total operating expenses of railroads that it becomes impossible to make the amount of work performed a criterion or measure of the cost. The fixed or inevitable expenses which attach to the operation of railroads, and which are the same whether one or many trains are run over a road, have to be ascertained separately in each individual case. These expenditures are in the nature of a tax upon the business of the road ; the smaller the business the larger the tax. What the tax may or should be per ton of freight or per passenger carried in any one case can not be predetermined by any general rule or law, but can only be ascertained after the two elements on which it depends — (i) the fixed expenditures, and (2) the amount of work done — are actually known. These elements vary on all roads ; it would be a singular accident to find them alike on any two. The disregard of these facts in estimating the cost and the value of railroad transportation with a view of judging of the reasonableness of railroad tariffs has led to many erroneous conclusions, which appear to be now fixed in the public mind. It is of great importance to the owners of railroad property at this present time — more so perhaps than heretofore — to possess correct information upon the subject of the cost of railroad transportation. It may therefore not be considered out of place here to show how the cost of transportation varies upon the various roads operated by the Louisville & Nashville Railroad, and the reasons therefor. The following table (A) shows the percentage of the four classes of expenditure above referred to, of the total' operating expenses on the seven roads operated by the Louisville & Nashville Railroad Company. The move^nent expenses, the cost of conveying freight from one place to another after it is loaded in the cars — the transportation expenses proper — are 41.3 per cent on the Main Stem, and only 17.6 on the Richmond Branch, of the total operating expenses. We have therefore in one case 5 8. 7, in the other 82.4 per cent of the total operating expenses, vi'hich are entirely uninfluenced by the amount of work performed as measured by weight and distance, or ton-miles. Movement expenses (comprised of items 41-73, tables II and III). — It appears that on the first four roads this class of expenditures varies from .73 cents to .97 cents per ton-mile; on the last three named from 1.50 cents to 5.49 cents per ton-mile. The first four roads belong to that class on which fully loaded freight-trains can be started from one terminus of the road ; on the last three named trains are started at regular times, regardless of the amount of load that is to be carried. Hence we find greater agreement in the cost of moving one ton one mile on the first four roads than on the latter, on which the cost depends altogether upon accidental causes. If on the first four roads the grades, curves, and the cost of labor and material were the same, and also the character of the business, then the cost per ton-mile should be the same; but as these elements of cost differ, uniformity in the cost even in the movement expenses can not be expected. twice as much as on the Knoxville Branch. On the first-named road a large amount of freight is carried over its whole length; while on the latter, which is a mere local road, it only passes over a portion of its whole length. The capacity of the locomotive and train can not therefore be as fully utilized on the latter as on the former road. On the Main Stem the tonnage in one direction is 73 per cent of the tonnage in the other direction, while on the Knoxville Branch it is only 21 per cent; hence more empty cars have to be run on the latter than on the former road. The result is that an average of 135 tons of freight is being carried per train on the Main Stem, while only 77 tons can be carried on the Knoxville Branch; yet the same attention is paid on both roads to secure maximum loads to each train. On roads on which there is not sufficient business to secure full loads to the trains from one or the other of the terminal stations the difference in the movement expenses per ton is found still greater. It is on account of the small loads carried on the Glasgow Branch per train (4.9 tons) that the movement expenses are so much larger than on the other branches, on which the trains carry from 18.2 to 24 tons. Supposing that the cost of handling freight per ton were the same on all roads and at all stations of a road, then the cost per ton-mile of freight would vary according to the length of haul. For each particular length of haul there would be a different cost per ton-mile for this service. By reference to Table IV it will be seen that the average cost of station expenses per ton of freight handled on the Main Stem of the road is 23 cents. For freight that passes over the whole length of the line, say between Louisville and Memphis, the cost per tonmile would be ^3.^-=^o.\2 cents, and for freight carried only five miles it would be ^-"3--^= 9. 2 cents. We have therefore a difference between the cost per ton-mile from 0.12 to 9.2 cents, although the actual cost of performing the work was the same in both cases; thus showing that the ton-mile is not a proper unit of measure of cost of this service. one ton of freight at various stations, as will appear from an examination of Table IV, which shows the station expenses per ton and the number of tons of freight handled at each station. We can ascertain from this table, in connection with Table XXVII, the average cost per ton-mile of freight handled at each station. The latter table gives the number of ton-miles of freight received and forwarded from each station. Dividing the number of tons into the number of ton-miles gives the average haul, and dividing this into the cost per ton for handling gives the average cost per ton-mile for handling freight. For example, take Brooks Station. Number of tons of freight received and forwarded (Table IV), 654; freight to and from Brooks Station was carried 14,335 utiles (Table XXVII) ; therefore the average haul ^^•?\|-^=2i.8 miles; station expenses per ton at Brooks Station (Table IV), 71 cents; cost per ton-mile JJ;g-=3.26 cents. To this has to be added the expenses at the station from or to which the freight was forwarded. If both stations are known, the cost per ton-mile for station expenses can be readily ascertained from Table IV. For example, for freight shipped between Louisville and Brooks Station, distance 9.2 miles : This example sufficiently illustrates the great variety in cost, and the impossibility of making the ton-mile the measure of cost of or compensation for this service. The ton handled would be a more correct measure, although there is necessarily much variety even in this cost, as we have seen, and as will still further appear from an examination of Table IV. It must therefore be evident that it is impossible to predetermine the cost per ton-mile of freight for handling without taking into consideration the length of the haul and the conditions under which the station service has to be performed. The following table shows the cost of maintenance of roadway and general expense per mile of road on the seven roads operated by the Louisville & Nashville Railroad Company during the last year, and the average number of tons of freight passed over one mile of each road ; also the cost per ton-mile : Part of the cost of maintenance of roadway and buildings is chargeable to the passenger traffic. The division of charges between the two classes of traffic has been made in proportion to train-miles. It follows from this that the cost per ton-mile of freight is in a measure affected by the relative use made of a road by the passenger and freight traffic. From this statement will be noticed the great difference in cost of maintaining one mile of road, buildings, etc. On the Main Stem this cost is $1,857.87, on the Glasgow Branch $262.73 per mile. An examination of the items from i to 28, Table III, will show in what particulars these differences occur. A few may be mentioned here. The cost per mile on the Main Stem and Glasgow Branch is as follows: difference is caused from the fact that on one road greater expenditures were made during this year than was due to the year's business; on the other road less. It will be remembered that the yearly depreciation of cross-ties on the Main Stem was found to be for i6j^ years at the rate of $257.11 per mile, while during the past year there was expended $368.89 on the Main Stem, and on the Glasgow Branch only $32.96 per mile; the first sum more, the latter considerably less than is required to make good a year's depreciation. There are great differences in other expenses, such as repairs of bridges, on the two roads. On the Main Stem, as has been mentioned before, the cost of bridge repairs during the last year was unusually heavy, while on the Glasgow Branch, with only one small bridge, the cost is very small. The general expenses of administration on the Main Stem are not incurred on the Glasgow Branch, which is also exempt from taxation. Hence the great difference in cost of maintenance of road and buildings and general superintendence between the two roads. When we examine into the differences existing in regard to the amount of business transacted in one year over one mile of road — the other element named which enters into the cost of one ton per mile — we find the variation still greater. On the Main Stem 433,662 tons, on the Glasgow Branch only 6,137 tons, pass over one mile of road per year. We can therefore not be surprised that the cost on the Main Stem for maintenance of road is only one fourth of a cent per ton-mile and on the Glasgow Branch 1.8 cents. hiterest account. — The original cost of the road and the rate of interest form one element and the amount of business transacted the other which determines the cost per ton-mile. The cost of roads per mile and the business transacted over the same vary so much that the cost per ton-mile for interest can not be expected to be the same in any two cases. It is impossible to predetermine what is a proper charge for interest on any particular road until these elements — viz., the cost of road and the amount of business — are known. On the Main Stem of the Louisville & Nashville Railroad, dividing the number of ton-miles of freight carried into the interest chargeable to the freight business, the cost per ton-mile is 0.46, while on the Richmond Branch it is 10.86 cents, over twenty times as much. On the We have now considered the variation in each class of expenditures and the causes therefor per ton-mile. When we find so much variation in the elements which make up the cost of transportation we can not expect to find uniformity in the total cost. From Table B it appears that the variation in the total cost per ton-mile is from 1.78 cents on the Main Stem to 19.09 cents on the Glasgow Branch. The work performed — viz., the movement of one ton of freight one mile — is the same on all roads, yet the cost of performing is ten times more on one road than on the other. Great as this variation is on the seven roads under the same management, the variation of the cost per ton-mile is still greater even on the same road, depending as it does upon the different conditions under which the service has to be performed. It would lead here too far to thoroughly analyze the cost of railroad transportation in all its details, and I will only state that a careful investigation shows that under the ordinary conditions under which transportation service is generally performed the cost per ton-mile in some instances may not e'xceed one seventh of a cent and in others will be as high as 73 cents per ton-mile on the same road. The lower cost applies to freight carried in cars that otherwise would return empty; the higher cost to freight in small quantities carried short distances. It is impossible to predetermine the cost of carrying freight on any one road unless the conditions under which it is to be carried, as far as they affect the cost of transportation, be previously known. In order to estimate the cost of transportation under the various conditions that occur it is necessary to classify the expenditures, and to separate those that increase with the amount of work done from those that are fixed and independent of it; and to ascertain the ratio of increase of cost with the increase of work. Without such an analysis of the cost it is impossible to solve the question of cost of transportation that arises in the daily practice of railroad operation. A mere knowledge of the average cost per ton-mile of all the expenditures during a whole year's operation is of no value whatever in determining the cost of transporting any particular class of freight, as no freight is ever transported under the average condition under which the whole year's business is transacted. We can therefore not make the average cost per ton-mile the basis for a tariff, if it is to be based upon cost; but we must classify the freight according to the conditions affecting cost, and ascertain the cost of each class separately. COMPARISON BETWEEN RAILROAD AND OTHER TRANSPORTATION. The problem of ascertaining the cost of railroad transportation is"* not quite so simple as it may at first sight appear. It is much easier to determine the cost of wagon, canal, or steamboat transportation. The common carrier by wagon or canal knows the exact amount of toll he has to pay, and assumes no risk of an investment in an expensive roadway. Nature furnishes a roadway to the carrier by steamboat, and keeps it in repair free of charge. Hence in estimating the cost of transportation by wagon, canal, or steamboat two of the most uncertain and changeable elements, and at the same time the costliest, of railroad transportation are eliminated from the calculation. Railway companies are not only common carriers ; they are also proprietors of a roadway. Their tariff charges are not only for transportation service proper, for the service rendered as common carriers, but also for the use of the roadway, for its maintenance, and. for the risk assumed in the investment. Notwithstanding this distinctive character of railroad service, as compared with that performed by other common carriers, it is sought to regulate the tariffs of railroads and to judge, compare, and criticise the same by the same measure or rule that applies properly only to the service of common carriers; viz., the measure of weight of freight and distance to which it is carried. The idea prevails that the cost of transportation of a ton of freight on one railroad should not materially differ from that on others, and that the cost of moving freight should be in exact proportion to the distance to which it is carried. These rules might be applied with some degree of justice to the cost of moving freight, although even here discrimination between different roads and different lengths of haul must be made; but the measure of weight and distance — the ton-mile — can not be used as a measure of cost incurred by railroad companies as proprietors of the roadway. This service must be measured by different rules. The cost of the roadway, the rate of interest and discount in obtaining money. form the proper data for calculation. On the seven roads operated by the Louisville & Nashville Railroad Company the cost of maintenance of road and interest on investment, when distributed over the number of ton-miles carried over the roads, is as follows (see Table B, page 20) : 12.6492 This statement shows the great difference in cost, from 0.7 cents to 12.6 cents per ton-mile, although the service rendered is exactly the same : the use of the roadway for one mile for the purpose of moving over it one ton of freight. Were these roads owned by one party and used by another (the latter common carriers merely), the toll, or the charge for the use of the roadway, would have to be made according to these figures, in order to reimburse the proprietor for the cost of the service. If the .common carrier would then charge separately for his services for moving the freight by the ton-mile, and for handling, warehousing, and taking care of it by the ton, the difference between the charges for the service as common carriers on the different roads would not be so great. If the charges for railroad transportation were thus subdivided, the reasonableness of the same could be more readily explained and understood. The confusion which exists in the minds of some people on the subject of railroad tariffs arises from the prevailing practice of combining the charges for three distinct services in one, and applying a measure to the whole which only can properly be. applied to a portion of it. So strong has become the conviction in the public mind that there should be uniformity in the cost of railway transportation that it has found expression in some of the states in legislative acts enforcing uniformity in compensation, while the natural laws governing cost, causing, as we have seen, so great a difference, are allowed to operate undisturbed. The ton-mile, without further inquiry as to its adaptability, is made the measure of cost. If by comparing the tariffs of different roads, or the tariff for different services on the same road, a difference be dis- ticing extortion and unjust discrimination. Upon such evidence as this laws have been enacted in some states for the purpose of preventing extortion, and which affect injuriously railroad property and the rights of a great many innocent people. GOVERNMENTAL REGULATION OF RAILROAD TARIFFS. It can not be denied that a law forcing railroad companies to furnish the use of their roads and to transact the business of a common carrier for less than cost is simply a law of confiscation, no matter under what pretext of authority it is enacted. It can hardly be maintained, in the light of our knowledge of human nature, that at the time the contracts between some of the states and the builders of the roads were made the latter were given to understand, as distinctly and clearly as they are now made to understand, that the state reserved the right to confiscate their property at pleasure. It appears that the interpretation of the law by one party to the contract was a great surprise to the other, originating as it did many years after the contract was made, during which time the construction now put upon it was not thought of or sought to be enforced. In ordinary cases the true meaning of a contract, if not unequivocally expressed, is determined from the manner in which the same has been executed through a long period of time ; but this does not seem to hold good when railroads are parties to the contract. The question as to the right and the extent of the right of the government of a state or the national government to prescribe fixed compensation for specific transportation services, or to regulate in a more general manner the railroad tariffs, is one of great interest and importance to all owners of railroad property. The relations of the Louisville & Nashville Railroad Company to the states in which it is located are well defined by the several charters ; yet the national government, at least one branch of it, has lately claimed jurisdiction over railroad tariffs, on the plea of having the power under the constitution to regulate commerce between the states; and there prevails a general tendency in the public mind that something must be done in the way of railroad legislation. to carry way freight (including the cost of handling it) at a rate not exceeding 25 per cent over the lowest rate per mile charged at the same time for through freight. A full explanation of the chartered rights of the company, and of the bearing and effect of such a law upon the railroads of the state and upon public interests, was made to the intelligent committees of both legislative branches, and this was sufficient to prevent the final enactment of that law. In the legislature of the state of Tennessee several laws on the subject of railroad tariffs passed through one and some through the other branch of the legislature, and only failed at the close of the session for want of time. property of that state. It is true that such legislation could be clearly proven illegal and void, both under our charters and under the constitutions of the states, yet during the time required to do so great losses might be inflicted upon the stockholders, and expensive and troublesome litigation would follow. All of which can be avoided by a more thorough knowledge of the subject on the part of the people and their representatives. It can be readily shown that many of the difficulties of what is called the railroad problem are only apparent. They have their existence in the ignorance of the people upon this subject, and as soon as the facts appear in their full and true light most of them will vanish without the aid of legislative interference. report at so great length. Nine tenths of the stockholders of the Louisville & Nashville Railroad and its leased lines are citizens of the states in which their roads are located ; the question of legislative control of railroads in this instance is not a mere party question between the people and "soulless corporations," but it is a question between the people who furnish the transportation and the people who use the roads. To a great extent they are the same, a great portion of the road being owned by cities and counties. A careful study therefore by the people of the facts and questions involved becomes almost a matter of necessity in the preservation of their own property. The subject of legislative enactments regarding the tariffs of railroads not owned by the government must be considered in two aspects — first, as to the abstract right of the government to establish tariffs; and second, as to the practicability of establishing and enforcing the same so as to accomplish the object for which the control is undertaken. The first question is one of law, and must be decided by the courts in accordance with contracts, charters, and constitutions; but the second is a question for the consideration of experts in the management of railroads, and must be decided from a knowledge of the facts and the natural laws controlling the subject. Should the courts decide that the government has the right to establish or control railroad tariffs, and it be found in the nature of the case that the exercise of that right necessitated the violation of other fundamental laws, the question as to the abstract right would become of secondary importance. There is a decision on record that bears upon this subject. It is not reported in the law-books, but has been universally approved. A certain citizen of Venice was given the right under the law to take one pound of flesh from a fellow-citizen. He found it impossible to obtain It without also taking blood, and probably life, to which he had no lawful claim; and the judgment therefore remained unexecuted. The right of the government to establish and enforce railroad tariffs does not carry with it the right to confiscate the property of railroad c ompanies. If a tariff can not be established and enforced unless the property of railroad companies is used without due compensation and without their consent, then this right ought not to be exercised, unless it be contended, as it has been by some, that "might is right." But even then it would soon be discovered that to deal unjustly with railroad companies will react sooner or later injuriously upon the public interest, and that to act in accordance with the dictates of justice in this as in all other cases will prove the best policy. The question as to the right and policy of governmental interference with railroad tariffs practically resolves itself into this question : whether it be possible for the legislature to undertake this control without the violation of other laws and the rights of parties interested, and in such a manner as to fully accomplish the object for which this control is undertaken. This question I will now consider. The first principle that should guide the formation of railway tariffs stands written in the good book — " the laborer is worthy of his hire." Those furnishing transportation for others should be reimbursed for at least the cost. Had this principle not been recognized at the time the roads were built, few would now be in existence, and if it is to be repudiated now, few will be constructed hereafter. The proper basis of railroad tariffs is therefore the cost of the transportation service. I have shown in this report the great variation in the cost of railway transportation on different roads, and the causes which necessarily bring about this result. From it necessarily follows the impossiblity of enacting general laws establishing tariffs applicable to more than one road. What is reasonable compensation for railway transportation service, or what constitutes just or unjust discrimination in railway charges, is not a question that can be decided a priori, or that can be formulated into a general law. It can only be decided in each individual case, when all the conditions under which the service is performed and the elements controlling' its cost are known; in most cases it can only be decided correctly after the service has been performed. It would be just as sensible to predetermine by legislation what shall be the cost of raising a bushel of corn as to predetermine the cost of carrying a ton of freight. The action of the sun and rain upon the growth of the corn and the quantity of the yield are no less uncertain elements than some of the elements which enter into the cost of transportation, service. The average cost of moving one ton one mile on the Main Stem of the Louisville & Nashville Railroad is 1.78 cents; on the Glasgow Branch 19.09 cents. What justice would there be in establishing a law requiring both roads to work for the same compensation ? Nor would it be more just to classify the railroads and enact a special tariff for each class, as no general laws exist or have as yet been discovered under which such classification could be made; the various combinations of elements of cost are different on and peculiar to each road, controlled as they are by local causes. The great difference in cost referred to in this report occurs in the average cost per ton-mile of transportation during the period of a whole year; but there is still greater difference in the cost of transportation of one ton one mile on the same road, varying with the conditions under which the service is performed, according to the length of haul, the quantities in which freight is transported, and whether the freight is carried in cars that would have to return empty or in special trains. I have mentioned that according to these and other conditions it may cost one seventh of a cent only in some cases and seventy-three cents in others to transport one ton of freight one mile. The labor therefore of forming a tariff based strictly upon cost is very intricate, and not of such a character that it can be properly performed by legislative bodies as at present constituted. The only mode in which they could act would be to appoint competent officers, whose duty it would be to ascertain the cost of transportation on each individual road, and to establish a tariff accordingly. If this duty could be properly performed, few railroad companies would complain, as the majority work for less than cost. A tariff so established strictly upon the basis of cost would, however, be of little use unless it be accompanied by a law forcing the people to ship over the road a certain quantity of freight at the established rates. If they are left free to select other modes of transportation that may be cheaper, then it would soon become apparent that the railroad would be of use only to a very limited number of people ; as the number of shippers is decreased, the cost of transportation would be increased in many cases to such an extent that the -turnpike would furnish a cheaper mode of transportation. The fact would soon become evident that railroad tariffs can not be based upoji the cost of transportation alone. Other elements enter into their formation that can not be ignored, if it be intended to develop fully the usefulness of railroad property both to its owners and to the public. The question that greatly controls railroad tariffs is what is the service worth, not what does it cost; and this is a mere commercial question, uncontrollable by acts of legislation. The relative value of an article at the place from and to which it is shipped determines the charges for transportation it can bear. If a greater charge is made than the difference in these values, the article can not be moved. It may therefore become necessary to charge on some articles less than the full cost of transportation in order to enable it to be moved at all; and this necessitates again to charge more on others which can bear higher charges. An element is here necessarily introduced of a purely commercial character, and which requires a knowledge of the value of articles in the different markets of the country between which they are to be exchanged, situated often far beyond the limits of any one state. This element must necessarily work constant changes in tariffs, and it would therefore be impossible to predetermine the same or fix them by legislative action. There is another disturbing element that prevents fixed railroad tariffs. // is competition. The simple question requires to be answered. Will you carry freight and passengers for the same that other transportation lines charge, either by rail or river, or will you not carry them at all ? All that has to be known by the railroad manager to answer this question is the minimum cost at which the service can be performed. K the obtainable rate exceeds cost, no matter how little, it becomes his interest to accept the terms offered. The important question to be decided is what is the minimum cost? In the statements I have given on page 20 the average cost of transportation per ton-mile for four different classes of expenses were given. Two of these classes are not affected by the work done, but are fixed; viz., the cost of maintenance of road and the interest on the investment. On the Main Stem of the Louisville & Nashville Railroad they amounted to 0.72 cents per ton-mile, or 40 per cent of the whole cost, and the expenses for moving and handling freight were 1.06 cents per ton-mile. Now it follows that when freight is to be carried at a rate fixed by competition, and can not be carried at all if a greater rate is demanded, the Louisville & Nashville Railroad Company can carry the same at the rate of 1.06 cents per ton-mile, and not lose thereby; if it could obtain more, the additional receipts would be just so much profit, applicable to lowering the rate on other freight. Yet if the Louisville & Nashville Railroad Company was to be forced by law to do all their business at this low rate, the expenses would exceed the income by 40 per cent, and the road could not be operated at all. Tlic company would prefer to abandon the competitive business and arrange the tariff for way business, by charging, when this is possible, as much more as the profit on the competitive business would have amounted to. From this it will be seen that the transaction of this competitive business, apart from the indirect benefits which it may exercise, is more to the advantage of the shipper whose location does not give him competitive privileges than to the railroad company. Notwithstanding this fact, the carrying of competitive freight at low rates> k the most fruitful source of complaint on the part of the shipper who pays higher rates. It has given rise to the charges so commonly preferred against railroad companies of making unjust discriminations in their tariffs, and against which legislative protection has mainly been invoked. It is maintained that to carry freight between distant competitive points at lower rates than between intermediate points where no competition exists is an act of injustice to the shippers at the latter points. This conclusion is based upon the assumed principle that common carriers are bound to serve their customers alike. The application, however, of a general principle to complicated transactions, such as take place in the business of common carriers, without taking into account a// the facts bearing upon the same, is apt to lead to erroneous conclusions, as it does in this case. I will illustrate this subject by a special case which is a representation of many. Louisville and Memphis are connected by navigable rivers, and in the exchange of commodities between the two cities they have always had the benefit of low rates of river transportation. A railroad 377 miles long is built connecting the two cities, passing through a number of interior places, which had before only imperfect communications. Suppose one of these places, called A, be located on the line of this road, 100 miles from Memphis and 277 from Louisville ; how is it affected by the construction of the road? Before the road was built freight from Louisville destined to A was shipped to Memphis by river and then by wagon to A. Since the road has been built there are two routes from Louisville to A, one by river to Memphis and, thence by rail, and the other by rail direct to A. Taking the first route, the charge for shipping to A is made by adding to the river rate from Louisville to Memphis the rail rate for 100 miles from Memphis to A. This latter rate is much below the rate formerly charged by wagon, and to the extent of this difference the shipper at A has been benefited by the construction of the road, not to mention the greater convenience and saving in time of which he now gets the benefit. This ought and would be satisfactory if the road stopped at A ; but the fact that a new route is opened to him, direct from Louisville, only 277 miles, causes all the trouble. The railroad is obliged to carry freight from Louisville to Memphis at the low river rate, which is much below the average cost of railroad transportation; but it derives from this rate a small profit, for reasons fully explained on page 34. It is obliged for the same reasons to charge its customer at A more per ton-mile for the distance of 277 miles than is charged to Memphis; but this can in no case exceed the sum of the river and rail rates from Louisville to A via Memphis, for if it did, the latter route would be the preferred one. Now the fact that the railroad carries freight from Louisville to Memphis through A at a lower rate than it carries it from Louisville to A is considered an act of injustice to the shipper at A, and he demands that he be put on the same, or even a better, footing with the shipper at Memphis, who always had the advantage of lower rates of transportation before the road was built. His demand amounts to this, that the railroad company having expended millions of dollars in the construction of a railroad connecting the interior places, which were without the improved modes of transportation, with two cities upon navigable rivers, conferring thus a great benefit upon those interior places, shall, in consideration of having done so much, do still more, and secure for them the same advantages possessed by the places situated upon the banks of navigable rivers. It is rather surprising that some courts have decided this position to be right. They have declared it unjust discrimination for railroad companies to charge higher rates of transportation to intermediate than more distant points, a decision based upon the improper application of the principle that common carriers must not make any distinction among shippers. the common carrier who creates the same arbitrarily, but the nature of things makes them necessary. To pursue anotlier course than that indicated would result to the disadvantage of all concerned and benefit no one. Were the low competitive freight to be refused, the cost of carrying other freight would be increased. If the same rate was to be charged to all interior points as to the competitive points, the railroad could not be operated at all. Different localities are more or less favored in regard to transportation facilities, either by nature or the enterprise of man. It can not be maintained that it is the duty of the common carrier to equalize these existing inequalities at his own expense. All that is required of him is not to create them himself arbitrarily. He must treat all alike that are situated alike ; but he can not be bound to wipe out existing differences. He may be obliged to carry freight at a lower rate to some localities than to others, but this in itself does not constitute an injustice or injury to the shipper in a less favored locality, as long as the charges made are reasonable in themselves and alike to all in the same situation. Discriminations are the necessary result of competition, and competition is the best protection against extortionate charges — much more efficient than any artificial legislative device. To take away the right from railroad proprietors to establish their tariffs upon the recognized principles that guide all other commercial transactions, and substitute fixed tariffs or arbitrary rules on which they must be based, would destroy the great usefulness of railroads. It may be and has been asserted that the effect of competition is not felt upon way business for which no direct competition is possible. This, however, is an erroneous view. When there is competition at any one point upon a railroad it makes itself felt over some portion of the road, more or less, according to the situation of the competing line. The truth of this can be illustrated by again referring to the case already cited. The rate from Louisville to an intermediate station on the road from Louisville to Memphis is established, as I have shown, by adding to the river rate to Memphis the railroad rate frorti Memphis to this intermediate station, which I have called A. The rail rate is limited by the charter, which prescribes maximum rates, or where this is not the case it would be limited by the consideration as to what constitutes a reasonable compensation for loo miles of rail transportation, and could in no case exceed the rates charged for transportation by other modes that might be available from Memphis to A. It is therefore the competitive river rate from Louisville to Memphis that influences and establishes the rate to this interior point. As the number of competitive points is multiplied on any one road the rates to a greater number of interior points are influenced, and this to a greater extent. Thus the Memphis Line from Bowling Green, where it diverges from the Main Stem to Memphis, 259 miles in length, is crossed by two navigable rivers and four other railroads, establishing thus six competing points. The shippers over this line can therefore always avail themselves of the competitive rates to the nearest point. They can in no case be charged more from Louisville direct to any station of the road than the competing rate and the rate of the short rail haul added, no matter what may be the distance from Louisville to the interior point. The consequence is that all the interior points enjoy the benefit of whatever competition there is; but it also follows that the tariff" upon such a line can not be constructed upon a mileage basis, but must make more or less discrimination between the different localities according as they are affected by competition. It may necessarily require freight to be hauled over a longer distance for much less than it is carried for a shorter distance. It is either this or the abandonment of competitive business. If railroad companies could agree among themselves to stop competition to junction points, one of the most fruitful causes of complaint against discrimination in railroad tariffs would at once be remedied; but it would be at the expense of the benefit of competition. The same result must follow if the rates to competing points are determined by the legislature of the state in which they are situated. But in this case competitors by river and railroads in other states should also be compelled to maintain these rates; otherwise the roads over which the state has complete control could not do business at all at competing points. Surely the people could not be benefited by such a course; it would be much better to let the natural laws of competition have their full force. To interfere with them is certainly not to regulate but to obstruct commerce, for which there is no authority in the constitution of the United States. and difficult problem ; but the more complicated we find it to be, the more reasonable it is to assume that it can better be solved by those who are directly interested, who practically devote their whole time and attention to it, than by members of a legislature, a majority of whom may be presumed to be utterly ignorant of this special subject. It is generally supposed that the right to establish their own tariffs gives great power, liable to abuse, into the hands of railroad managers, but upon closer investigation it will be found that the extent of this^ power is generally much overrated. Enlightened self-interest dictates its exercise reasonably, and in a spirit of liberality; competition, especially with water transportation, circumscribes it into the narrowest limits, if it does not nullify it altogether. On the roads operated by the Louisville & Nashville Railroad Company the maximum legal rates authorized by the charter vary from 7 to 10.2 cents per ton per mile. The average actual charge made is 2.172 cents. Why does not the company charge more, having an undoubted right to do so? Other causes than the mere will of the managers limit the charges. In one case it is competition, in another the freight is of such a character that it can not bear higher charges, or both of these causes are in operation at the same time. I can assert from my personal experience that on 920 miles of railroads, stretching in all directions over a large territory of country, the managers have no more to do with the making of the tariffs than to study the conditions and limitations to which I have referred, and to conform to the same. The result is that the tariff charges on these road= arc b^it from 20 to 30 per cent of the maximum authorized by law. I can also affirm that a similar state of affairs exists in regard to the large number of railroads with whose affairs I am acquainted. If the mere will of the managers, w.ich'jckcu by other considerations, had absolute control over railroad tariffs, would it be likely that so many roads in the United States would be in the hands of receivers; so many more unable to pay dividends to stockholders; so comparatively few paying the usual interest on the cost of construction; and so few paying a larger interest? Any one who asserts that the railroads in this country as a whole are guilty of extortion only shows his own ignorance of the facts, easily accessible, and exhibited by the statistics in regard to the financial result of railroad operation in the United States. The truth is that than its cost, at the expense of the owners of railroad property. The general practice of citing one or two cases of unreasonable railroad charges, or a few cases where railroad companies pay dividends upon watered stock, and basing upon this the charge that all or the great majority of railroads in the country are doing this, is manifestly unjust. If the charge is made against the railroad system as a whole, it stands refuted by the general result of its operations as a * whole. That errors are committed by railroad managers in arranging their tariffs, especially in details, can not be denied (and this is equally true in other important human avocations), nor can it be wondered at, if we bear in mind the complications and difficulties of this work. But as the interests which are intended to be served necessarily suffer from these errors, it should be presumed that they are the result of ignorance rather than evil intent, and the only correction in this matter is better information, sounder judgment, and greater intelligence. If these requirements could be supplied by legislation, the end would be accomplished. Much might be done by instituting intelligent inquiry and investigation of the facts bearing upon the subject, and by disseminating the result among the people. In this direction legislative influence should first be exercised. First, that such control can not be exercised by general laws establishing fixed railroad tariffs without a violation of the rights of the parties ownir.^ Cw.^ p.op'^'rty. confirms the correctness of these conclusions. Mr. Charles F. Adams sums up the result of his thorough investigations of the subject of governmental interference with railroad tariffs in the report of the railroad commissioners to the legislature of the state of Massachusetts. Referring especially to Great Britain, he says, "Nowhere has the system of special legislation been more And again: "The result of thirty years of successive and wholly abortive efforts in this direction in England has been that Parliament has at last settled down in the conviction that the developments and necessities of trade in practice always have nullified, and inevitably must nullify, the special acts, no matter how carefully and skillfully they may be prepared." It is only surprising that it should have required thirty years to establish a fact that must appear evident at once if we thoroughly analyze the nature of the object sought to be attained, and the instruments and means available for its attainment, and still more surprising when we consider that the object of all the efforts referred to could be simply reached by enforcing the commo?i law, which prohibits common carriers from making unreasonable charges for transportation. Let the parties guilty of a violation of this law alone be held responsible. This course has been deemed sufficient heretofore to prevent wrong-doing, and if followed and adhered to, should also be sufficient to prevent extortion on the part of railroad companies. It has been urged against the efficiency of the law that the expense of litigation deters individuals from seeking redress. To remove this objection the state could provide an indictment against offending railroad companies, and throw the cost of litigation upon the commonwealth. It has also been urged that it is difficult, if not impossible, to make proof of the unreasonableness of railroad charges. Several plans have been proposed to remove this objection. The House of Representatives of the United States proposed a law by which nine commissioners were to guess at the rates which should be considered reasonable. I say guess, because it would be entirely impossible for nine men to ascertain what are reasonable rates, upon correct principles, for all roads in the United States. The legislatures of some states have adopted arbitrary tariffs, which are to be considered reasonable until proved otherwise. The object of these measures is simply to throw the burden of proof as to the reasonableness of transportation charges upon the railroad companies. But in so doing it raises fictitious issues; it declares certain things reasonable which are not so, and makes an untruth the basis upon which a legal action is to be brought. It is difficult to perceive why all this complicated machinery was invented to reach an object that can be simply reached by enacting a law which shall throw at once the burden of proof upon the railroad companies. Such a law would be perfectly just and proper. It is the business of the common carrier to know when he establishes a tariff that it is in accordance with the requirements of law; and having all the facts bearing upon the question in his possession, he should have no difficulty in making the proof. A rigid and frequent application of the law as above suggested to railroad carriers would soon prove whether the many complaints made are based upon facts or upon fiction. The judicial investigation in a number of cases, aided by the testimony of experts in railroad management, would soon bring to light and establish the proper principle upon which questions as to extortionate rates and unjust discriminations should be decided ; and it would not be long before people would learn to understand and look upon the subject in its proper light. The present persecution of railroads, which in some parts of the country has become a mania, is not unlike the persecution of witchcraft in former years. It must cease as soon as intelligence has taken the place of ignorance. When this point has been reached many of the supposed difficulties of the railroad problem will be solved. I propose now, after having referred to the subject of railroad transportation in general, to complete the report of the operations of the Louisville & Nashville Railroad during the past year. The contents of tables I to XXV, relating to the expenditures, were referred to on pages 8 to 17. I wish now to refer to the remaining tables, from XXVI to XLV, containing information in regard to the tonnage and number of passengers transported, and the revenue derived therefrom, and showing also the sources from which the business is derived, character of the freight, etc. Table XXVI shows the number of tons and ton-miles of local and through freight transported ; the total revenue received from freight; also the revenue and the operating expenses per ton-mile on each road. Table XXXVI shows the revenue from freight and passengers at each station of the road, and the tons of freight and number of passengers carried one mile from and to each station. Table XXXVII shows the tonnage of and revenue from freight carried between Louisville and Nashville, coming from or destined to Louisville and all points North, or coming from or destined to Nashville and all points South. Table XXXVIII shows the tonnage of and revenue from freight carried between Louisville, Memphis, and all junction points on the Memphis Line, arriving from and destined to Louisville, Memphis, and points beyond. The preceding tables contain full information in regard to the competitive freight business, the sources from which derived, and its value to the company. The rates at which each separate class of business is carried and the net profits derived from each can be ascertained, and the question decided how profitable it is to the company or when it ceases to be so. through passengers, and the average revenue per mile. Table XLIII shows the number of local passengers on Main Stem and branches, and revenue derived from same on each road. This table shows the interchange of local passenger traffic between the various roads. ESTIMATES OF THE VALUE OF BRANCH ROADS TO MAIN LINE. From tables XLIV and XLV we are enabled to make estimates of the value of the branch roads and extensions of the main line as feeders to it. One of the principal feeders is the Memphis Line. Its business passes over ii8 miles of the Main Stem. From Table XLIV it appears that the gross earnings of the Main Stem from passenger business coming from or going to the Memphis Line are $145,995.40. At 29.13 per cent the net earnings of the Main Stem — its total net earnings on account of this business — were 42,528 46 From Table XLV it appears that the gross freight earnings on the Main Stem derived from that line were $368,588.69, and net earnings, 39.20 per cent 144,486 76 the Main Stem may be estimated as follows : Proportion of gross passenger earnings on Main Stem from business coming from or going to these two branches (Table XLIV) on ^536,937.42 at 29.13 per cent net profit is iO)7S9 87 Recapitulating the results of the above estimates, we have the proportion of the net earnings which the Main Stem has derived from the business of the extension and branches as follows : But we must consider that in the above estiinate of the net earnings we have only taken the average net earnings. The large amount of business thrown on the Main Stem by these feeders has greatly reduced the operating expenses. The reduction so made may be estimated as follows: The operating expenses on the Main Stem were 63.8 per cent of the gross earnings. The operating expenses on account of the $415,525.96 net earnings derived on the Main Stem from the business of the branch roads can therefore be estimated at \|\|;\| X Twenty per cent of these expenses belong to that class which are fixed and independent of the amount of business (see Table A, p. 20, interest excluded), so that without the business that was brought to the Main Stem by its feeders the expenses of transacting the other business This estimate shows that branch roads and extensions, although they may not be profitable in themselves, may become so by the influence they exercise upon the net revenue of the main line. It may occur even that a whole system of roads — main line and branches — is not remunerative, yet the final financial result that must be considered the test of the judiciousness of the investment in branch roads — the proportion of the net revenue to the capital invested — may be greater with than without the branches. It is therefore not possible to judge correctly of the judiciousness of such investments unless correct estimates can be made showing the net earnings directly and indirectly obtained on account of branch roads and extensions.	19,327	common-pile/pre_1929_books_filtered	costofrailroadtr00fink	public_library	public_library_1929_dolma-0023.json.gz:4611	https://archive.org/download/costofrailroadtr00fink/costofrailroadtr00fink_djvu.txt
jy3ibAIGAVrsCBXW	ReStorying Education	5 What Do We Know: Assessment of Teaching and Learning Loren Jones; Shannon Kane; Sarah Morris; and Margaret Peterson Before We Read Before we read, reflect on how assessments have impacted your learning. What aspects of assessments did you find helpful? Challenging? What qualities do you think make an assessment effective? Take a few minutes to skim the chapter headings and subheadings and consider what you already know about assessment. What are the different types and purposes of assessment? How can assessments be used to inform and improve teaching and learning? What are some ethical considerations when designing and implementing assessments? Finally, consider the different stakeholders involved in assessment (teachers, students, parents, administrators, district leaders). What are their perspectives on assessment? By engaging with these questions before diving into the chapter, you will activate your prior knowledge and be better prepared to understand the complex concepts related to assessment. Critical Questions For Consideration As you read, consider these essential questions: What are some ethical considerations when designing and implementing assessments? How can educators work to limit assessment bias? And consider the different stakeholders involved in assessment (teachers, students, parents, administrators). What are their perspectives on assessment? Defining Assessment and Its Challenges Assessments in public schools have long been a topic of discussion and debate, with stakeholders ranging from policymakers to educators, parents, and students expressing various opinions and concerns. Recently, the media has played a significant role in shaping public discourse around assessments and their impact on the education system. For example, consider the Edweek headline, “Two Decades of Progress, Nearly Gone: National Math, Reading Scores Hit Historic Lows” (Edweek, October 24, 2022), or NPR’s headline U.S. reading and math scores drop to lowest level in decades. These headlines, though, portray a distorted public perception of teaching and learning in today’s classrooms. One might read this headline and believe our school systems, administrators, and teachers are “not good enough,” but the truth is much more complicated. Rather than capturing the day-to-day functioning of the classroom, high-stakes assessments are generally imposed upon teachers rather than created by them. As such, the assessments and headlines don’t accurately capture the progress and performance of our students. When reading headlines related to schools and assessments, it is essential to be critical consumers of media messages. Consider that the headline examples above, and many others, label schools as “failing” based on a single metric–a standardized test score. However, the focus is just on specific numbers and not a nuanced understanding of factors that influence these numbers, such as socioeconomic background, limited English proficiency, or special needs students. These complexities are rarely addressed and considered. Also, remember that standardized tests are snapshots in time, not measures of long-term progress. A school might slightly dip in scores one year but steadily improve overall. The media rarely considers these trends or highlights schools that are making significant gains year after year. Additionally, changes in test scores can have multiple explanations. Media portrayals often paint a simplistic picture of progress or decline. A score dip could be due to a temporary disruption or a shift in curriculum focus, not necessarily a failing school system. Media outlets might also select data points that fit a pre-existing narrative. For instance, they might focus on a single grade level’s decline or highlight achievement gaps without acknowledging progress in other areas. An unfair and inaccurate picture of performance is given by cherry-picking data and excluding information that discredits the narrative being told. Finally, as also discussed in chapter one, media portrayals often pit schools against each other or blame teachers. These actions can create a hostile environment and distract from the real work of improving education. Focusing on collaboration and solutions, rather than negativity and finger-pointing, would be far more productive. Assessment data should be an important tool for educators, but it can and often is misinterpreted by the media. The inaccurate or misinterpreted use of data by the media has historically led to a distorted public perception of the teaching and learning going on in classrooms. Typically, what’s highlighted in the news is external to the day-to-day functioning of a school or classroom. It is generally imposed upon teachers rather than created by them. The assessments discussed by mainstream media are not used to inform/shape classroom instruction. Instead, the type of data focused on by the media and splashed across headlines is often tied to the academic status of schools and districts, regardless of accuracy. We’ll discuss some kinds of assessments and their uses in the following sections. Norm-referenced versus Criterion-referenced Assessments Teachers and educational researchers use various assessment tools to gauge student learning and inform instructional decisions. However, these tools differ in their fundamental purpose and how they interpret performance. Two of the main approaches are norm-referenced assessments and criterion-referenced assessments. Norm-Referenced Assessments: - Focus: Compare a student’s score to the performance of a specific group (norm group). - Interpretation: Scores indicate percentile ranks or standardized scores (e.g., z-scores), revealing how students stand relative to their peers. - Examples: DIEBLS, ITBS SAT, ACT, State Achievement Tests - Strengths: Useful for ranking students, identifying gifted students, and making placement decisions. - Weaknesses: Do not directly measure mastery of specific learning objectives, are susceptible to test bias and anxiety, and have limited information about individual strengths and weaknesses. For some norm-referenced assessments, teachers do not receive scores until the summer or early fall the following year which means the data cannot be used to inform instruction. Additionally, the gap between the assessment and receiving scores fails to account for student progression or regression that may have occurred. Criterion-Referenced Assessments: - Focus: Compare a student’s score to a predetermined standard or criterion (learning objective). - Interpretation: Scores indicate mastery or non-mastery of specific skills or knowledge domains. - Examples: Rubrics, performance assessments, portfolios, exit tickets, and quizzes/tests aligned to learning objectives. - Strengths: Provide direct information about individual learning progress, guide instructional planning, inform targeted interventions, and promote mastery learning. - Weaknesses: Less useful for comparing students to peers, requires careful development of clear criteria, and may be subjective. Choosing the Right Tool Selecting the ‘right’ approach depends on the assessment’s specific goals and intended purpose(s). Norm-referenced assessments offer valuable insights for large-scale comparisons and rankings, while criterion-referenced assessments provide targeted feedback for personalized learning. Issues typically arise not from the assessment type but from the misuse or misrepresentation of the information gathered. When used correctly, both types of assessments can provide different pictures of student performance that support instructional planning. Formative and Summative Assessments Working to create learning environments that foster growth and understanding is a primary goal of all educators. Assessments can provide valuable insights into student learning and support creating a robust learning environment. However, successfully navigating the world of assessments means understanding key concepts, such as formative and summative, and how each plays a distinct role in effective teaching. Formative assessments are informal, ongoing checks for understanding. The main goal of formative assessments is to identify areas of strength and weakness in students’ grasp of the material. This allows you to adapt your teaching strategies quickly, providing targeted support and differentiated instruction to address individual needs. Examples include exit tickets, quick quizzes, observations, and peer feedback. The key is providing timely and specific feedback that helps students progress. By providing constructive and timely feedback, we can adjust our teaching strategies to address individual needs and ensure everyone stays on track. Summative assessments measure student learning at the culmination of a unit, grade/course. They aim to measure student achievement against predetermined learning objectives and standards. Examples include exams, projects, presentations, or standardized tests. While summative assessments can provide valuable data on overall learning outcomes, they often occur after the learning has already happened, limiting the opportunity to influence the learning process directly. The key to success lies in integrating both forms of assessment. Formative assessments inform your teaching, allowing you to individualize instruction, differentiate learning activities, and provide targeted support. This targeted support ultimately leads to improved performance on summative assessments, providing a comprehensive picture of student learning at the end of the learning cycle. Here are some practical takeaways related to formative and summative assessment: - Embed formative assessments regularly: Use various strategies to gather ongoing information about student learning. - Focus on feedback: Provide clear, actionable feedback to help students better understand both their strengths and areas for improvement. - Use formative data to inform instruction: Adapt your teaching based on student needs identified through formative assessments. - Balance formative and summative assessments: Utilize both to create a holistic picture of student learning and growth. Assessments should not simply be about collecting data or assigning grades; they are about using data to inform and improve the learning process for every student. By strategically employing formative and summative assessments, you can create a dynamic learning environment where feedback, support, and growth go hand in hand. \| Formative Assessment \| Feature \| Summative Assessment \| \| Identify areas of understanding \| Purpose \| Measure overall achievement \| \| Throughout instruction \| Timing \| End of unit/course/program \| \| Informal (e.g., discussions, exit tickets) \| Formality \| Formal (e.g., exams, projects) \| \| Low or no stakes \| Grading \| High stakes (often contribute to grades) \| \| Immediate and targeted \| Feedback \| May be delayed or general \| Connecting Assessment and Instruction Ideally, assessment and instruction should not be considered separately but instead viewed as two interconnected concepts that support student learning. Though assessment typically conjures images of tests and grades, it should instead be thought of as the ability to inform and guide instruction that supports student learning and mastery. Unlike summative assessments that gauge final achievement, formative assessments provide continuous feedback. Through observations, discussions, quizzes, and self-reflections, formative assessments provide teachers with insights into students’ strengths, weaknesses, and misconceptions. Ideally, this data informs instructional decisions, allowing teachers to: - Differentiate instruction by providing targeted support for struggling students and challenging activities for advanced learners. - Modify lesson plans to incorporate different teaching strategies, catering to diverse learning styles and preferences. - Identify and clarify misunderstandings before they solidify, preventing knowledge gaps from widening. - Encourage students to reflect on their learning. Effective assessment goes beyond simply collecting data; it’s about providing meaningful feedback. Meaningful feedback needs to be timely, specific, and actionable. Feedback can: - Focus on particular strengths, weaknesses, and areas for improvement rather than simply assigning grades. - Provide concrete suggestions for students to apply in their learning. - Be specific to individual student needs. When students are actively involved in the assessment process, they can take greater ownership in their learning. This can be achieved through: - Empowering students to reflect on their learning progress and set personal goals. - Creating space for students to give and receive peer feedback fosters critical thinking and communication skills. - They are utilizing collaborative assessments where students work together. The connection between assessment and instruction should not be a one-time event but a continuous cycle. Teachers use assessment data to inform instruction and refine their assessment practices. This iterative process ensures that assessments remain aligned with learning objectives and provide meaningful feedback for both teachers and students. Assessment and instruction should not be considered independent entities but two sides of the same coin. Teachers create an effective learning environment that informs instruction and refines assessment by leveraging formative assessment, providing effective feedback, and fostering student involvement. Assessment Driven Instruction In order for assessments to act as a guide for planning and teaching, teachers must first be clear about, and then plan for, what students will actually learn in a lesson or unit. Then, teachers must be clear about what assessment of that learning actually measures. Assessments begin with planning for teaching and learning, meaning that during planning, a clear “criterion for success” needs to be specifically named. Knowing the criterion for success means that a teacher can envision what mastery of a particular skill looks like and ways mastery can be illustrated by a learner. Too often planning falls short of naming specifically enough how a learner can illustrate mastery of a concept, and sometimes that leads to assessments that do not do a good job of measuring the actual learning sought. For example, a lesson objective states that at the end of the lesson, a student should be able to skip count by 3’s to 99. Then within the lesson students practice skip counting orally from 3-99. The assessment for that lesson should match the learning sought, so if students are asked to fill in the multiples of 3 on a chart, this isn’t an exact match for the learning in the lesson. A written assessment of the skill of skip counting adds in assessment of number formation, or the ability to place the numbers in a chart. This keeps this assessment from providing a good snapshot of student learning, because of the mismatch between what and how students learned something and how they are asked to show they have learned it. In the late 1990s, Researchers Grant Wiggins and Jay McTighe called the idea of planning for teaching by first thinking about learning, Backwards Design. They described this kind of planning as a way to foreground what students would know or be able to do at the end of a learning segment. They argued that the “output” of learning and teachers’ assessments of it, were far more important than planning that focused on what the teacher would do in a lesson. This may not sound like a groundbreaking perspective, but it is an important perspective shift to be able to foreground learning (the output) rather than teaching (the input). For teachers, this means that before planning begins, they must “think a great deal, first, about the specific learnings sought, and the evidence of such learnings” (Bowen, 2017). The evidence of learning is the basis for thinking about how a teacher can assess student learning to provide meaningful information. This shift to foregrounding learning also means that we plan for learning “before thinking about what we, as the teacher, will do or provide in teaching and learning activities” (Bowen, 2017). So, for teachers in the field, this means there is a need to become more specific about what real evidence of learning looks like; what is actually being assessed, in order to create classrooms that are assessment driven and where student learning can be seen. Overview of Assessment – Common Assessments in Classrooms Considering the importance of assessment and the many ways it is used to both guide and gauge progress in teaching and learning, we’ll turn now to common classroom assessments and to the types of learning they are designed to assess. We’ve divided these assessments into two categories here. The first category encompasses assessment of knowledge and skills related to content; the second category encompasses assessments of learner attitudes, beliefs and self awareness of how they relate to a content or topic. \| Assessing Content Related Knowledge and Skills \| Purposes \| Common Classroom Examples \| \| Assessing Prior Knowledge, Recall, and Understanding What do students already know or believe about this topic? \| Guiding of planning, teaching and pacing, grouping of students. \| KWL, entrance ticket, mind map around the focus topic, soliciting oral responses to questions \| \| Assessing Skill in Analysis and Critical Thinking Do students understand the related parts, concepts, issues of the content they are learning? \| Guiding of teaching, formative assessment of content, formative assessment of depth or complexity of understanding. \| Schematic drawings, process maps, webs and extended mind maps, short writing about the topic, outlines \| \| Assessing Skill in Synthesis and Creative Thinking Do students understand, and can they apply knowledge of the content in their own ways? \| Guiding of teaching, formative assessment of content, formative assessment of depth or complexity of understanding, formative assessment of mastery. \| Reenactments, synthesis and summary writing, essay, creating a play illustrating the content, creating illustrations of the content, extending a story, comparing two ideas or situations. \| \| Assessing Skill in Problem Solving Do students have skills to identify types of problems they are solving? Do students have multiple algorithms, or strategies for solving the problem? Can students solve the problems by applying solutions in novel ways? \| Guiding of teaching, formative assessment of skill development, assessment of content, formative assessment of depth and complexity of understanding, practice of application of strategies. \| Student Think Aloud, solving problems and showing your work, collaborative work to solve problems and explain thinking behind problem solving. \| \| Assessing Skill in Application and Performance Can students apply skills in new settings, can they use a number of skills together to accomplish a task, even when skills are learned in a new setting? \| Guiding of long-term planning, Summative assessment of content, summative assessment of application of new knowledge and skills. \| Performance based tasks including writing, demonstrating, performing, reenactment, explanations, posters, reports, presentations \| \| Assessing Learner Attitudes, Beliefs, Values and Self Awareness \| Purposes \| Common Classroom Examples \| \| Assessing Students’ Awareness of Their Attitudes and Values \| Aid student to see what they must “unlearn” to begin to develop new knowledge and skills. Consider beliefs, biases and attitudes that will make it more difficult for students to learn new skills and develop new knowledge. \| Interest surveys and inventories, KWL charts, reflective writing, class discussion, conferences, ratings \| \| Assessing Students’ Self-Awareness as Learners \| Helps students to know about themselves as learners. Builds student skills in gauging their successes as learners. \| Student surveys, reflections on learning,learning target discussions, evaluative discussion of models, discussing and co-creating criteria \| \| Assessing Course-Related Learning and Study Skills, Strategies, and Behaviors \| Help students to develop strategies to strengthen learning of specific skills and application of skills and knowledge \| Student surveys and inventories, reflective writing, discussion and explication of learning processes \| Validity, Reliability of Assessment Validity and reliability are two key concepts related to assessment. These terms indicate the quality and accuracy of measurement tools, ensuring that the data collected is meaningful, trustworthy, and helpful in making informed decisions. Understanding these concepts is fundamental for creating assessments that accurately measure their intended purpose. Validity refers to how accurately a conclusion or measurement reflects what is being assessed. In other words, does the assessment assess the construct or concept it claims to assess? For example, if a literacy test claims to measure students’ comprehension skills, its validity would be questioned if it primarily tests phonics. Validity can be assessed through various methods, such as criterion-related and construct validity. Criterion-related validity examines the relationship between the assessment scores and some external criterion, such as performance in real-world situations. Construct validity evaluates whether the assessment accurately measures the underlying theoretical construct it is designed to measure. Reliability is the extent to which a set of results or interpretations can be generalized over time, across tasks, and among interpreters of assessment information. A reliable assessment tool produces consistent results when repeatedly administered under the same conditions. It should yield similar scores for individuals with the same trait or ability level. Reliability can be determined through different methods such as test-retest reliability and parallel forms reliability. Test-retest reliability involves administering the same assessment to a group on different occasions and looking for consistency of scores across administrations. Parallel forms reliability involves administering two equivalent forms of the same assessment to the same group of individuals and examining the consistency of scores between the two forms. Valid and reliable assessments are essential for accurately evaluating students’ knowledge, skills, and abilities in education. They inform teachers about students’ strengths and weaknesses, guide instructional planning, and facilitate evidence-based decision-making. Valid and reliable assessments also play a crucial role in research, ensuring that the data collected is credible and can be used to draw meaningful conclusions and advance knowledge in various fields. By upholding high standards of validity and reliability, practitioners can enhance the credibility, utility, and effectiveness of assessment tools in their classrooms. Some Common Assessments In this section, you will learn about some assessment tools that are commonly used in K-12 classrooms. Some of these are assessments you may even have completed yourself as a student. Some are used nationally across many K-12 districts, such as DIBELS and WIDA Access testing, and some are specific to states, and are used, as required by federal laws, as large scale assessments to try to measure and track educational achievement in specific subject areas, such as reading or math. DIBELS First developed by researchers at the University of Oregon in the 1970’s, DIBELS assessments were initially designed to help show beginning phonemic awareness in kindergarten through 3rd grade. Additional subtests developed over decades now focus on assessing many foundational skills for reading in kindergarten through 8th grade students. In one test students are asked to identify the sounds heard at the beginning of common words; to sound out and decode nonsense words, but all DIBELS assessments are designed to “detect risk,” meaning to monitor the ongoing progress of readers and identify gaps in foundational literacy skills. DIBELS have been redesigned to assess all of the foundational skills needed for reading development, identified by the National Reading Panel in 2000 (Learning Point, 2004). DIBELS seeks to assess students’ ongoing proficiency with the foundational skills of phonemic awareness, phonics. fluency, vocabulary development and comprehension. Though this assessment is still used widely, it’s important to note that there have been many critiques of DIBELs over the years including the fact that the tests are designed to assess extremely specific skills readers use, but that exist within complicated processes for learning to read. For example one of DIBELS assessments asks students to decode made up syllables, which critics say may remove contexts of language, and motivation for a reader, adding to miscues and over identification of reading delays or need for remediation. WIDA Access Testing WIDA stands for World-class Instructional Design and Assessment, and comes from researchers at the University of Wisconsin, Madison and their ACCESS test is widely used in the US to assess English language proficiency levels for students identified as English Language Learners (ELL). The assessment is used to help to discern several key pieces of language learning, including listening, speaking, reading and writing. Scores are used to help identify the kinds of instruction that an ELL will need to increase their English proficiency across all of the language domains. ACCESS testing is designed to show the progress a student has made and is given at the beginning of a school year and near the end of a school year to help provide important information about how, and in what language domain, a student is progressing well, or not. ACCESS scores, which range from 1 or “entering” and 6 or “reaching,” are used to determine when and if a student can “exit” services mandated as English for Speakers of Other Languages (ESOL). Though several states use a lower score to allow students to stop receiving ESOL services. The designation as an English Language Learner, most often decided by scores on a WIDA Access test, means that a student is legally entitled to receive ESOL services and can not be denied those services until they are able to show they have gained the necessary skills for proficiency in English. Though, it should be noted that several states use a lower score to allow students to stop receiving ESOL services. Advanced Placement Testing Developed at the end of World War II, the goal of both the AP test and the introduction of college level coursework to high school classrooms was part of an effort to better and more quickly prepare students for college and career. In 1955 the College Board took over the administration of AP courses, and the AP tests themselves. From the original 11 topics; Mathematics, Physics, Chemistry, Biology, English Composition, Literature, French, German, Spanish, and Latin, the College Board now offers AP tests in 34 subject areas. Many colleges and universities recognize and will award college credit for scores above a 3 or 4 on AP tests for commensurate coursework. These credits may not count for degree completion in some cases and at several elite colleges, scores don’t count at all. For example, Brown University, Dartmouth, Williams, and Cal Tech do not award credit for any AP test. As a result some high schools have begun to phase out, or have completely abandoned AP coursework. For example, in 2018, eight prestigious high schools including Georgetown Day, Holton-Arms, Landon, Maret, National Cathedral, Potomac, St. Albans and Sidwell Friends, announced they would completely phase out AP courses by 2022. Criticism of the Advanced Placement program has long centered around controversy that the tests are racially biased and that the coursework does not allow students and teachers to go in-depth into topics in ways a college course might. Standardized Tests – A Lay of the Land – Looking Forward All states in the United States that receive federal funds for education, which includes all states as well as the DODEA and Bureau for Indian Education and the District of Columbia, are required to gauge student achievement through the use of standardized tests of student learning. These tests are standardized in that they use a similar set of questions, and tests agreed upon skills. These tests are, to varying degrees, aligned with state curricula, to assess students at several points during elementary school and in multiple subjects during secondary public education. There have been many efforts over the years to work to make education more a part of the federal standardized system and laws such as the ESEA, or Elementary and Secondary Education Act, have provided systems of rewards, and or penalties for states to support federal requirements. For a period of time beginning in 2010, the United States Department of Education worked to create a national set of standards called College and Career Readiness Standards, that also required a standardized test called by its acronym PARCC, or the Partnership for Assessment of Readiness for College and Careers. States could opt into the consortium and at its most popular, 22 states had signed on to use this common assessment and its constituent curriculum. PARCC is now in use in only the District of Columbia, The Bureau of Indian Education and in DODEA, and there does not seem to be political will to build more standardization across states for assessments. A quick look at what standardized tests each state is using to gauge student achievement shows that many states have created their own state made and state administered tests including the Colorado Measures of Academic Success (CMACS) and the Florida Assessment for Student Thinking (FAST). But many states, including California, Connecticut and Nevada have again signed on to a consortium of states using the Smarter Balanced Test which aligns with the older College and Career Readiness Standards and was developed with input from both teachers and higher education on test questions and content. Standardized tests, while meant to show student learning, have been used in many states as a way of trying to assess teaching, with some states connecting teacher evaluations and pay to student outcomes on standardized tests. These models are flawed in multiple ways, as standardized test scores are positively correlated to family levels of education and socioeconomic status. Again assessments and tests, even large scale standardized tests are, at best, a snapshot of student learning and can tell us very little about instruction, or future achievement of students. Conclusion As we have discussed in earlier sections, tests and test scores often hold outsized influence on the lives of humans inside of classrooms. Teachers may be paid or promoted based on students’ standardized test scores. Students may be retained at a specific grade level, or not gain admission to a college based on a test score. And though we know that tests used to gauge student learning often don’t provide definitive information on student knowledge or learning, and that scores are often skewed based on race, socioeconomic status and on family educational attainment, teachers must become critical consumers of tests and assessments. Meaning that it is important to question test questions, to research who is profiting from tests and testing materials, and to be skeptical of results that disadvantage students. Still assessing is one of the most important skills any teacher can develop. Guided by questioning, as ongoing assessments of learning, quizzes, observations, and meaningful and qualitative evaluation of student work are all very important data needed to guide both teaching and learning, to identify risks to student learning and to help to remediate and enrich student learning. Meet A Scholar Sonia Nieto: Championing Equity in EducationDr. Sonia Nieto (1943- ), a leading scholar in multicultural education and advocate for educational equity, has played a crucial role in shaping critical conversations around educational assessments. Her work has helped draw attention to and highlight standardized tests’ limitations and potential biases related to students from diverse backgrounds. While not directly involved in developing assessments, her work has profoundly influenced how educators approach and interpret these tools, emphasizing the importance of equity and fairness in assessments and advocating for approaches that accurately reflect individual strengths and needs. The ‘one-size-fits-all’ approach to traditional assessments creates the potential to perpetuate educational inequities by disadvantaging students from marginalized backgrounds due to inherent biases. These biases can stem from cultural assumptions embedded in the language, content, and scoring criteria, leading to inaccurate representations of students’ authentic abilities. Similar to instructional strategies, assessment methods should consider students’ diverse learning styles and cultural backgrounds and allow students to demonstrate their understanding in meaningful ways. This overall approach to teaching and learning emphasizes the importance of: - Utilizing authentic materials: Assessments should reflect students’ cultural backgrounds and lived experiences, making them more relatable and engaging. - Incorporating multiple assessment methods: Employing varying assessment tools, including performance-based tasks, portfolios, and self-reflection, to provide a well-rounded perspective beyond test scores of student learning. - Considering cultural context: Recognizing the influence of cultural background on learning styles and communication preferences is crucial for interpreting assessment results accurately and avoiding misinterpretations. Sonia Nieto has played a significant role in promoting inclusive and equitable education, including assessments. Her work continues to inspire educators and inform policymakers to create instructional systems that accurately reflect the diverse potential of all students. To learn more about Dr. Nieto’s work on linguistic diversity, visit Chapter 5. Critical Discussion Questions - What are the unintended consequences of current assessment practices, and how can we mitigate them? - How can we effectively assess the complex skills and dispositions valued in 21st-century learning? - How can we create assessment systems that are culturally responsive and address the diverse needs of all learners? - How can we involve students in the assessment process to promote self-reflection, ownership of learning, and a growth mindset? Reflection, Metacognition, and Alternative Assessments One concern with assessment in many school forms is authenticity. As we have discussed in this chapter, assessment can serve many purposes: it can be used to classify and divide students into groups; it can be used to drive instruction; it can be used to shape curriculum; it can be used to generate revenue for textbook and educational resource companies. Assessment can be standardized and aligned with state or national curriculum. But our students aren’t all the same. They learn differently. What are we doing to assess those differences? And what are multiple ways students can SHOW their learning? In what ways can we use assessment to provide learners with more information about how they learn, so they can make choices and have agency in their learning? Some scholars and teachers focus on metacognition and self-assessment as ways for students to be in charge of their own learning. Metacognition is, on a basic level, “thinking about thinking,” or learning to understand one’s own thought processes (Flavell, 1979). More specifically, metacognition requires learners to reflect and self-regulate in order to understand what they have learned and how they have learned it (Darling-Hammond, Austin, Cheung, and Martin, 2003). Reflection, as John Dewey claimed in 1933, is what generates learning, more so than experience alone. Metacognition and reflection can bring awareness and intentionality to learning and assessment of learning. As Taczak and Robertson (2017) argue, “when cognition and metacognition are accessed together through reflection, students are able to assess themselves,” and this assists transfer of skills and knowledge to other settings and fields (p. 212). Metacognitive assessments, then, allow learners to review their work, reflect on their progress toward goals, and predict their learning outcomes based on their performance and understanding. They also allow learners to self-regulate by setting goals and plans for future learning. Portfolios are one example of metacognitive assessment, one that is holistic, student-centered, and developed over time. In this section, we will discuss a few types of alternative assessments, ones that include students’ own thinking, self-assessment, and reflection. Alternative Assessments Portfolios. Often used in writing classrooms, portfolios are purposeful collections of work that students curate along with reflection and analysis of their progress. Often portfolios are designed in collaboration between and among students and teachers, can be individualized for each learner, and show student growth and development toward learning goals over time. In the writing classroom, portfolios emphasize revision and the writing process over the final product. Students must review, categorize, analyze, organize, and plan how to show a reader not only what they learned, but how they learned it (Reynolds and Davis, 2014). In some situations, students are asked to document revisions, and most writing portfolios incorporate some element of reflective writing in order to describe, narrate,and explain the texts within the portfolio, considering a student’s work as evidence of their growth (Yancey, 1998). Accompanied by other means of assessment, such as those recommended by the National Council of Teachers of English (1993), including “narrative evaluations, written comments, dialogue journals, and conferences” portfolios can be individualized to each learner and involve the student as a participant in their own learning and assessment, thereby assisting in developing agency. Alongside portfolios as assessment, some teachers work with their students to design assignments and develop guidelines for assessment to counter typical classroom power structures (Reif, 1992). Doing so challenges the notion that teachers control the criteria for defining “good” work. Student Designed Rubrics. We have discussed rubrics (and critiques of them) earlier in this chapter. Now, let’s consider rubrics in which students have a say in design, evaluative criteria, and values. Grounded in constructivist principles, the act of designing a rubric as a class dwells in process space (rather than product focus) and relies on students effectively analyzing conventions of the genres they read and are expected to write, and then translating into their own words those conventions, aiding in transfer to their own writing. In assisting in identifying and defining assessment criteria, students are given agency and participate in co-constructed understandings that are made more powerful within the discourse community. When combined with other strategies for writing, reflection, and revision within a discourse community, and used formatively over time, not only do student designed rubrics assist in reflection, self-assessment, and deep reading, they promote transfer. In the foundational text “Writing as a Mode of Learning,” Janet Emig (1977) suggests that writing seeks “self-feedback,” in that the process of writing, when students learn to write in a “familiar and available medium,“ they are better able to give themselves feedback (p. 125). The process of designing a rubric together can make visible the kind of “self-feedback” unique to writing and bring it into a collective sense of response, creating a shared understanding of process, genre convention, and mode. In addition, the rubric becomes its own genre, that students can more easily access as readers in other contexts. Put together, different forms of alternative assessments resist what Peter Elbow (1993) calls “forms of judgment” in classrooms, or practices that seek to rank, rather than truly evaluate and value the work that students do. Anti-racist Assessment Practices In recent years, and in the wake of highly visible and racially motivated violence against people of color, school systems and higher education institutions have begun engaging in open discussion about how pedagogical practices feed systemic racism. While this is a developing conversation, there are some currently agreed-upon principles and practices recommended to help teachers ground assessment in anti-racist practice. In this section, we will introduce a few of those practices, with the expectation that readers will use these ideas as a springboard for further investigation. First, and perhaps most importantly, researchers suggest that teachers begin to implement anti-racist pedagogy by becoming critically reflective themselves. This means interrogating one’s own biases, developing an awareness of students’ individualities and backgrounds, and adjusting curriculum to convey diverse perspectives and meet learning needs. Assessments are one aspect of the curriculum that will need to be adjusted. As we have discussed, often, grades measure behaviors and compliance instead of actual learning. In redesigning assessments to foster anti-racist principles, we can make a few adjustments to instruction that make a difference in transparency, learning, and student agency. Teach what you’re trying to measure. First, we can align our assessments with course goals and objectives, so that we teach what we are trying to test. For example, if we’re asking students to write to show understanding of content in a social studies course, but we grade grammar and mechanics heavily without teaching grammar and mechanics, a student may have a clear understanding of the content but be penalized for errors in the technical aspects of writing. Give students practice and choice. Second, when we have taught something, we can facilitate transfer and ensure student learning by giving them direct, relevant practice and feedback on that practice. Allowing choice about how to show mastery is critical here, too, as it increases student investment in the learning. For example, if we want students to be able to write thesis statements, we must follow direct instruction in identifying and writing thesis statements with independent practice in the student’s own draft, on a topic of their choice. To further show mastery, students might select their own “best” thesis to share from several papers at the end of the assessment period. Allow for revision and reflection. Third, when assessments have a reflective component, students can identify and discuss how well they have mastered learning goals, with their own work as a kind of evidence. Given the opportunity to show not just what they know, but how they know they know it, students can better identify, define, and make an argument for their own learning. Likewise, the opportunity to revise assignments allows students to strategically apply new ideas and learning over time, which emphasizes learning as a process rather than assessment as a product. Two specific approaches to antiracist assessment are ungrading and contract grading. Ungrading is a feedback centered approach that counters the traditional grading system, which tends to rank, sort, and categorize students and their work. While there are many different approaches to ungrading, most include self-assessment, collaboration, reflection, and revision and are used across the curriculum in a variety of ways to foster justice and equity in an unjust system (Blum, 2020). Contract grading requires students to deeply self-assess using agreed-upon measures for mastery and allows students to choose projects and assignments that best meet their own learning needs and goals within the context of a course. Some educators, like Asao Inoue (2015, 2019), argue that labor based grading contracts are a tangible way to resist institutional racism by upending embedded power structures. APPLICATION Case Study: Multilingual learners across the nation (42 states are part of the WIDA consortium) complete the WIDA ACCESS assessment annually to monitor their growth in English across the four domains – speaking, writing, reading, listening. The images below capture two ACCESS Online Sample Items from Grades 4-5 in the domain of Reading for a selection titled “Let’s Go Shopping.” - Review the two assessment prompts – the questions, answer selections, and corresponding images. - Based on the information presented in this chapter, would you identify this as an effective assessment? - What is being assessed here? Does that align with the purpose of the assessment? - What can a teacher learn from the results of this assessment? - What might be some consequences of this assessment, both short term and long term? Post-Reading Activities on Assessment: - Design Your Ideal Assessment: Reflect briefly on the chapter’s key points on assessment methods and their strengths and weaknesses. Think of a learning scenario where you need to assess someone’s understanding of a topic and create your own assessment method for this scenario. Consider sharing your designed assessment to a partner. Be sure to consider factors like: - What learning objectives are you assessing? - What type of knowledge or skills do you want to measure? - What format would be engaging and effective (e.g., project, presentation, game)? - How would you ensure the assessment is fair and unbiased? - Learning Reflection: Think back to a recent learning experience (e.g., a class, workshop, online course) and reflect on the assessment methods used in that experience. Did they effectively measure your learning? What were the strengths and weaknesses of the assessments? How could they have been improved? Consider how the different assessment methods discussed in the chapter could be applied to your chosen learning experience. Which methods would be most appropriate and beneficial and why? - Assessment in the Real World: Think about a field or activity you are interested in, such as sports, music, or business. Identify and consider the different types of assessments used in your chosen context. For example, in sports, there might be performance evaluations, skill tests, and game statistics. Write a short reflection on the following questions: How do these assessments contribute to the overall goals of the activity or field? What are the potential benefits and drawbacks of these assessments? Are there alternative assessment methods that could be considered? References Blum, S. (2020). Ungrading : Why Rating Students Undermines Learning (and What to Do Instead). West Virginia University Press. Bowen, R. S. (2017). Understanding by Design. Vanderbilt University Center for Teaching. Retrieved [May 29, 2024] from https://cft.vanderbilt.edu/understanding-by-design/. Darling-Hammond, L., Austin, K., Cheung, M., & Martin, D. (2003). Thinking about thinking: Metacognition. The learning classroom: Theory into practice. Stanford University School of Education. Dewey, J. (1933). How we think: A restatement of the relation of reflective thinking to the educative process (2nd ed.). Heath. Elbow, P. (1993). Ranking, Evaluating, and Liking: Sorting out Three Forms of Judgment. College English, 55(2), 187–206. https://doi.org/10.2307/378503. Emig, J. (1977) Writing as a Mode of Learning. College Composition and Communication, 28; 2, 122-128. Flavell, J. H. (1979) Metacognition and cognitive monitoring: A new area of cognitive-development inquiry. American Psychologist, 34, 906-911. Inoue, A. (2015). Antiracist Writing Assessment Ecologies: Teaching and Assessing Writing for a Socially Just Future. The WAC Clearinghouse; Parlor Press. https://doi.org/10.37514/PER-B.2015.0698 Inoue, A. (2019). Labor-based grading contracts: Building equity and inclusion in the compassionate writing classroom. Fort Collins, CO: WAC Clearinghouse. Learning Point Associates. (2004). ERIC. Retrieved June 14, 2024 from https://files.eric.ed.gov/fulltext/ED512569.pdf. NCTE Executive Committee. (1993). Resolution on Grading Student Writing. National Council of Teachers of English. https://ncte.org/statement/gradingstudentwrit/. Reynolds, N., & Rice, R. (2014). Portfolio Teaching A Guide for Instructors (3rd ed.). Bedford/St. Martin’s. Rief, Linda. (1992). Seeking Diversity: Language Arts with Adolescents. Portsmouth, NH: Heinemann. Taczak, K., & Robertson, L. (2017). Metacognition and the reflective writing practitioner: An integrated knowledge approach. In P. Portanova, J. M. Rifenburg, & D. Roen (Eds.), Contemporary perspectives on cognition and writing (pp. 211–229). The WAC Clearinghouse, University Press of Colorado. University of Oregon. (2024). DIBELS: Dynamic Indicators of Basic Early Literacy Skills. https://dibels.uoregon.edu/about-dibels. Yancey, K.B. (1998). Reflection in the writing classroom. Utah State University Press. Glossary Backwards Design: A way to design units and lessons that begins at the desired results based on learning goals or content, or literacy, standards and then gathers evidence of learning based on performance or project-oriented assessments. Criterion-Related Validity: This is the extent to which an assessment is related to a purported outcome. For example, SAT and ACT exams claim validity because the scores correlate, or predict, college GPA. Construct Validity: How accurately a test measures a concept that the test designed to measure. Capacity measures like the Cattell Culture Fair Intelligence Test claim to have a construct validity in that the test creators claim the test measures cognitive abilities free from co-variants like sociocultural or environmental factors.	9,660	common-pile/pressbooks_filtered	https://restoryingeducation.pressbooks.sunycreate.cloud/chapter/what-do-we-know-assessment-of-teaching-and-learning/	pressbooks	pressbooks-0000.json.gz:86138	https://restoryingeducation.pressbooks.sunycreate.cloud/chapter/what-do-we-know-assessment-of-teaching-and-learning/
jxlvFWInDFsPkhH6	Western Civilization I	55 Reading: The Grand Duchy of Moscow The Formation of Russia Ivan III became Grand Prince of Moscow in 1462 and proceeded to refuse the Tatar yoke, collect surrounding lands, and consolidate political power around Moscow. His son, Vasili III, continued in his footsteps marking an era known as the “Gathering of the Russian Lands.” LEARNING OBJECTIVES Outline the key points that led to a consolidated northern region under Ivan III and Vasili III in Moscow KEY TAKEAWAYS Key Points - Moscow had risen to a powerful position in the north due to its location and relative wealth and stability during the height of the Golden Horde. - Ivan III overtook Novgorod, along with his four brothers’ landholdings, which began a process consolidating power under the Grand Prince of Moscow. - Ivan III was the first prince of Rus’ to style himself as the Tsar in the grand tradition of the Orthodox Byzantine Empire. - Vasili III followed in his father’s footsteps and continued a regime of consolidating land and practicing domestic intolerance that suppressed any attempts to disobey the seat of Moscow. Key Terms - Muscovite Sudebnik: The legal code crafted by Ivan III that further consolidated his power and outlined harsh punishments for disobedience. - Novgorod: Moscow’s most prominent rival in the northern region. - boyars: Members of the highest ruling class in feudal Rus’, second only to the princes. Gathering of the Russian Lands Ivan III was the first Muscovite prince to consolidate Moscow’s position of power and successfully incorporate the rival cities of Tver and Novgorod under the umbrella of Moscow’s rule. These shifts in power in the Northern provinces created the first semblance of a “Russian” state (though that name would not be utilized for another century). Ivan the Great was also the first Rus’ prince to style himself a Tsar, thereby setting up a strong start for his successor son, Vasili III. Between the two leaders, what would become known as the “Gathering of the Russian Lands” would occur and begin a new era of Russian history after the Mongol Empire’s Golden Horde. Ivan III and the End of the Golden Horde Ivan III Vasilyevich, also known as Ivan the Great, was born in Moscow in 1440 and became Grand Prince of Moscow in 1462. He ruled from this seat of power until his death in 1505. He came into power when Moscow had many economic and cultural advantages in the norther provinces. His predecessors had expanded Moscow’s holdings from a mere 600 miles to 15,000. The seat of the Russian Orthodox Church was also centered in Moscow starting in the 14th century. In addition, Moscow had long been a loyal ally to the ruling Mongol Empire and had an optimal position along major trade routes between Novgorod and the Volga River. However, one of Ivan the Great’s most substantial accomplishments was refusing the Tatar yoke (as the Mongol Empire’s stranglehold on Rus’ lands has been called) in 1476. Moscow refused to pay its normal Golden Horde taxes starting in that year, which spurred Khan Ahmed to wage war against the city in 1480. It took a number of months before the Khan retreated back to the steppe. During the following year, internal fractures within the Mongol Empire greatly weakened the hold of Mongol rulers on the northeastern Rus’ lands, which effectively freed Moscow from its old duties. Moscow’s Land Grab The other major political change that Ivan III instigated was a major consolidation of power in the northern principalities, often called the “Gathering of the Russian Lands.” Moscow’s primary rival, Novgorod, became Ivan the Great’s first order of business. The two grand cities had been locked in dispute for over a century, but Ivan III waged a harsh war that forced Novgorod to cede its land to Moscow after many uprisings and attempted alliances between Novgorod and Lithuania. The official state document accepting Moscow’s rule was signed by Archbishop Feofil of Novgorod in 1478. Any revolts that arose out of Novgorod over the next decade were swiftly put down and any disobedient Novgorodian royal family members were removed to Moscow or other outposts to discourage further outbursts. In addition to capturing his greatest rival city, Ivan III also collected his four brothers’ local lands over the course of his rule, further expanding and consolidating the land under the power of the Grand Prince of Moscow. Ivan III also levied his political, economic, and military might over the course of his reign to gain control of Yaroslavl, Rostov, Tver, and Vyatka, forming one of the most unified political formations in the region since Vladimir the Great. This new political formation was in contrast to centuries of local princes ruling over their regions relatively autonomously. Ivan the Great also greatly shaped the future of the Rus’ lands. These major shifts included: - Styling himself the “Tsar and Autocrat” in Byzantine style, essentially stepping into the new leadership position in Orthodoxy after the fall of the Byzantine Empire. These changes also occurred after he married Sophia Paleologue of Constantinople, who had brought court and religious rituals from the Byzantine Empire. - He stripped the boyars of theirlocalized and state power and essentially created a sovereign state that paid homage to Moscow. - He oversaw the creation of a new legal code, called Muscovite Sudebnik in 1497, which further consolidated his place as the highest ruler of the northern Rus’ lands and instated harsh penalties for disobedience, sacrilege, or attempts to undermine the crown. - The princes of formerly powerful principalities now under Moscow’s rule were placed in the role of service nobility, rather than sovereign rulers as they once were. - Ivan III’s power was partly due to his alliance with Russian Orthodoxy, which created an atmosphere of anti-Catholicism and stifled the chance to build more powerful western alliances. Vasili III Vasili III was the son of Sophia Paleologue and Ivan the Great and the Grand Prince of Moscow from 1505 to 1533. He followed in his father’s footsteps and continued to expand Moscow’s landholdings and political clout. He annexed, Pskov, Volokolamsk, Ryazan, and Novgorod-Seversky during his reign. His most spectacular grab for power was his capture of Smolensk, the great stronghold of Lithuania. He utilized a rebellious ally in the form of the Lithuanian prince Mikhail Glinski to gain this major victory. Vasili III also followed in his father’s oppressive footsteps. He utilized alliances with the Orthodox Church to put down any rebellions or feudal disputes. He limited the power of the boyars and the once-powerful Rurikid dynasties in newly conquered provinces. He also increased the gentry’s landholdings, once more consolidating power around Moscow. In general, Vasili III’s reign was marked by an oppressive atmosphere; he carried out harsh penalties for speaking out against the power structure or showing the slightest disobedience to the crown. Ivan the Terrible Ivan IV, or Ivan the Terrible, reigned from 1547 to 1584 and became the first tsar of Russia. His reign was punctuated with severe oppression and cultural and political expansion, leaving behind a complex legacy. LEARNING OBJECTIVES Outline the key points of Ivan IV’s policies and examine the positive and negative aspects of his rule KEY TAKEAWAYS Key Points - Ivan IV is often known as Ivan the Terrible, even though the more correct translation is akin to Ivan the Fearsome or Ivan the Awesome. - Ivan IV was the first Rus’ prince to title himself “Tsar of All the Russias” beginning the long tradition of rule under the tsars. - Lands in the Crimea, Siberia, and modern-day Tatarstan were all subsumed into Russian lands under Ivan IV. - The persecution of the boyars during Ivan IV’s reign began under the harsh regulations of the oprichnina. Key Terms - Moscow Print Yard: The first publishing house in Russia, which was opened in 1553. - boyar: A member of the feudal ruling elite who was second only to the princes in Russian territories. - oprichnina: A state policy enacted by Ivan IV that made him absolute monarch of much of the north and hailed in an era of boyar persecution. Ivan IV successfully grabbed large chunks of land from the nobility and created his own personal guard, the oprichniki, during this era. Ivan IV Ivan IV Vasileyevich is widely known as Ivan the Terrible or Ivan the Fearsome. He was the Grand Prince of Moscow from 1533 to 1547 and reigned as the “Tsar of all the Russias” from 1547 until he died in 1584. His complex years in power precipitated military conquests, including Kazan and Astrakhan, that changed the shape and demographic character of Russia forever. He also reshaped the political formation of the Russian state, oversaw a cultural Renaissance in Russia, and shifted power to the head of state, the tsar, a title that had never before been given to a prince in the Rus’ lands. Rise to Power Ivan IV was born in 1530 to Vasili III and Elena Glinskaya. He was three when he was named the Grand Prince of Moscow after his father’s death. Some say his years as the child vice-regent of Moscow under manipulative boyar powers shaped his views for life. In 1547, at the age of sixteen, he was crowned “Tsar of All the Russias” and was the first person to be coronated with that title. This title claimed the heritage of Kievan Rus’ while firmly establishing a new unified Russian state. He also married Anastasia Romanovna, which tied him to the powerful Romanov family. Domestic Innovations and Changes Despite Ivan IV’s reputation as a paranoid and moody ruler, he also contributed to the cultural and political shifts that would shape Russia for centuries. Among these initial changes in relatively peaceful times he: - Revised the law code, the Sudebnik of 1550, which initiated a standing army, known as the streltsy. This army would help him in future military conquests. - Developed the Zemsky Sobor, a Russian parliament, along with the council of the nobles, known as the Chosen Council. - Regulated the Church more effectively with the Council of the Hundred Chapters, which regulated Church traditions and the hierarchy. - Established the Moscow Print Yard in 1553 and brought the first printing press to Russia. - Oversaw the construction of St. Basil’s Cathedral in Moscow. Oprichnina and Absolute Monarchy The 1560s were difficult with Russia facing drought and famine, along with a number of Tatar invasions, and a sea-trading blockade from the Swedes and Poles. Ivan IV’s wife, Anastasia, was also likely poisoned and died in 1560, leaving Ivan shaken and, some sources say, mentally unstable. Ivan IV threatened to abdicate and fled from Moscow in 1564. However, a group of boyars went to beg Ivan to return in order to keep the peace. Ivan agreed to return with the understanding he would be granted absolute power and then instituted what is known as the oprichnina. This agreement changed the way the Russian state worked and began an era of oppression, executions, and state surveillance. It split the Russian lands into two distinct spheres, with the northern region around the former Novgorod Republic placed under the absolute power of Ivan IV. The boyar council oversaw the rest of the Russian lands. This new proclamation also started a wave of persecution and against the boyars. Ivan IV executed, exiled, or forcibly removed hundreds of boyars from power, solidifying his legacy as a paranoid and unstable ruler. Military Conquests and Foreign Relations Ivan IV established a powerful trade agreement with England and even asked for asylum, should he need it in his fights with the boyars, from Elizabeth I. However, Ivan IV’s greatest legacy remains his conquests, which reshaped Russia and pushed back Tatar powers who had been dominating and invading the region for centuries. His first conquest was the Kazan Khanate, which had been raiding the northeast region of Russia for decades. This territory sits in modern-day Tatarstan. A faction of Russian supporters were already rising up in the region but Ivan IV led his army of 150,000 to battle in June of 1552. After months of siege and blocking Kazan’s water supply, the city fell in October. The conquest of the entire Kazan Khanate reshaped relations between the nomadic people and the Russian state. It also created a more diverse population under the fold of the Russian state and the Church. Ivan IV also embarked on the Livonian War, which lasted 24 years. The war pitted Russia against the Swedish Empire, the Polish-Lithuanian Commonwealth, and Poland. The Polish leader, Stefan Batory, was an ally of the Ottoman Empire in the south, which was also in a tug-of-war with Russia over territory. These two powerful entities on each edge of Russian lands, and the prolonged wars, left the economy in Moscow strained and Russian resources scarce in the 1570s. Ivan IV also oversaw two decisive territorial victories during his reign. The first was the defeat of the Crimean horde, which meant the southern lands were once again under Russian leadership. The second expansion of Russian territory was headed by Cossack leader Yermak Timofeyevich. He led expeditions into Siberian territories that had never been under Russian rule. Between 1577 and 1580 many new Siberian regions had reached agreements with Russian leaders, allowing Ivan IV to style himself “Tsar of Siberia” in his last years. Madness and Legacy Ivan IV left behind a compelling and contradictory legacy. Even his nickname “terrible” is a source for confusion. In Russian the word grozny means “awesome,” “powerful” or “thundering,” rather than “terrible” or “mad.” However, Ivan IV often behaved in ruthless and paranoid ways that favors the less flattering interpretation. He persecuted the long-ruling boyars and often accused people of attempting to murder him (which makes some sense when you look at his family’s history). His often reckless foreign policies, such as the drawn out Livonian War, left the economy unstable and fertile lands a wreck. Legend also suggests he murdered his son Ivan Ivanovich, whom he had groomed for the throne, in 1581, leaving the throne to his childless son Feodor Ivanovich. However, his dedication to culture and innovation reshaped Russia and solidified its place in the East. The Time of Troubles The Time of Troubles occurred between 1598 and 1613 and was caused by severe famine, prolonged dynastic disputes, and outside invasions from Poland and Sweden. The worst of it ended with the coronation of Michael I in 1613. LEARNING OBJECTIVES Outline the distinctive features of the Time of Troubles and how they eventually ended KEY TAKEAWAYS Key Points - The Time of Troubles started with the death of the childless Tsar Feodor Ivanovich, which spurred an ongoing dynastic dispute. - Famine between 1601 and 1603 caused massive starvation and further strained Russia. - Two false heirs to the throne, known as False Dmitris, were backed by the Polish-Lithuanian Commonwealth that wanted to grab power in Moscow. - Rurikid Prince Dmitry Pozharsky and Novgorod merchant Kuzma Minin led the final resistance against Polish invasion that ended the dynastic dispute and reclaimed Moscow in 1613. Key Terms - Feodor Ivanovich: The last tsar of the Rurik Dynasty, whose death spurred on a major dynastic dispute. - Dmitry Pozharsky: The Rurikid prince that successfully ousted Polish forces from Moscow. - Zemsky Sobor: A form of Russian parliament that met to vote on major state decisions, and was comprised of nobility, Orthodox clergy, and merchant representatives. The Time of Troubles was an era ofRussian history dominated by a dynastic crisis and exacerbated by ongoing wars with Poland and Sweden, as well as a devastating famine. It began with the death of the childless last Russian Tsar of the Rurik Dynasty, Feodor Ivanovich, in 1598 and continued until the establishment of the Romanov Dynasty in 1613. It took another six years to end two of the wars that had started during the Time of Troubles, including the Dymitriads against the Polish-Lithuanian Commonwealth. Famine and Unrest At the death of Feodor Ivanovich, the last Rurikid Tsar, in 1598, his brother-in-law and trusted advisor, Boris Godunov, was elected his successor by the Zemsky Sobor (Great National Assembly). Godunov was a leading boyar and had accomplished a great deal under the reign of the mentally-challenged and childless Feodor. However, his position as a boyar caused unrest among the Romanov clan who saw it as an affront to follow a lowly boyar. Due to the political unrest, strained resources, and factions against his rule, he was not able to accomplish much during his short reign, which only lasted until 1605. While Godunov was attempting to keep the country stitched together, a devastating famine swept across Russian from 1601 to 1603. Most likely caused by a volcanic eruption in Peru in 1600, the temperatures stayed well below normal during the summer months and often went below freezing at night. Crops failed and about two million Russians, a third of the population, perished during this famine. This famine also caused people to flock to Moscow for food supplies, straining the capital both socially and financially. Dynastic Uncertainty and False Dmitris The troubles did not cease after the famine subsided. In fact, 1603 brought about new political and dynastic struggles. Feodor Ivanovich’s younger brother was reportedly stabbed to death before the Tsar’s death, but somepeople still believed he had fled and was alive. The first of the nicknamed False Dmitris appeared in the Polish-Lithuanian Commonwealth in 1603 claiming he was the lost young brother of Ivan the Terrible. Polish forces saw this pretender’s appearance as an opportunity to regain land and influence in Russia and the some 4,000 troops comprised of Russian exiles, Lithuanians, and Cossacks crossed the border and began what is known as the Dymitriad wars. False Dmitri was supported by enough Polish and Russian rebels hoping for a rich reward that he was married to Marina Mniszech and ascended to the throne in Moscow at Boris Godunov’s death in 1605. Within a year Vasily Shuisky (a Rurikid prince) staged an uprising against False Dmitri, murdered him, and seized control of power in Moscow for himself. He ruled between 1606 and 1610 and was known as Vasili IV. However, the boyars and mercenaries were still displeased with this new ruler. At the same time as Shuisky’s ascent, a new False Dmitri appeared on the scene with the backing of the Polish-Lithuanian magnates. An Empty Throne and Wars Shuisky retained power long enough to make a treaty with Sweden, which spurred a worried Poland into officially beginning the Polish-Muscovite War that lasted from 1605 to 1618. The struggle over who would gain control of Moscow became entangled and complex once Poland became an acting participant. Shuisky was still on the throne, both the second False Dmitri and the son of the Polish king, Władysław, were attempting to take control. None of the three pretenders succeeded, however, when the Polish king himself, Sigismund III, decided he would take the seat in Moscow. Russia was stretched to its limit by 1611. Within the five years after Boris Godunov’s death powers had shifted considerably: - The boyars quarreled amongst themselves over who should rule Moscow while the throne remained empty. - Russian Orthodoxy was imperiled and many Orthodox religious leaders were imprisoned. - Catholic Polish forces occupied the Kremlin in Moscow and Smolensk. - Swedish forces had taken over Novgorod in retaliation to Polish forces attempting to ally with Russia. - Tatar raids continued in the south leaving many people dead and stretched for resources. The End of Troubles Two strong leaders arose out of the chaos of the first decade of the 17th century to combat the Polish invasion and settle the dynastic dispute. The powerful Novgordian merchant Kuzma Minin along with the Rurikid Prince Dmitry Pozharsky rallied enough forces to push back the Polish forces in Russia. The new Russian rebellion first pushed Polish forces back to the Kremlin, and between November 3rd and 6th (New Style) Prince Pozharsky had forced the garrison to surrender in Moscow. November 4 is known as National Unity Day, however it fell out of favor during Communism, only to be reinstated in 2005. The dynastic wars finally came to an end when the Grand National Assembly elected Michael Romanov, the son of the metropolitan Philaret, to the throne in 1613. The new Romanov Tsar, Michael I, quickly had the second False Dmitri’s son and wife killed, to stifle further uprisings. Despite the end to internal unrest, the wars with Sweden and Poland would last until 1618 and 1619 respectively, when peace treaties were finally enacted. These treaties forced Russia to cede some lands, but the dynastic resolution and the ousting of foreign powers unified most people in Russia behind the new Romanov Tsar and started a new era. The Romanovs The Romanov Dynasty was officially founded at the coronation of Michael I in 1613. It was the second royal dynasty in Russia after the Rurikid princes of the Middle Ages. The Romanov name stayed in power until the abdication of Tsar Nicholas II in 1917. LEARNING OBJECTIVES Explain the rise of power of the House of Romanov and the first major Russian Tsars of this dynasty KEY TAKEAWAYS Key Points - The Romanovs were exiled during the Time of Troubles but brought back when Romanovs Patriarch Philaret and his son Michael were politically advantageous. - Michael I was the first Romanov Tsar and began a long line of powerful rulers. - Alexis I successfully navigated Russia through multiple uprisings and wars and created long-lasting political bureaus. - After a long dynastic dispute, Peter the Great rose to power and changed Russia with the new capital of St. Petersburg and western influences. Key Terms - Old Believers: Followers of the Orthodox faith the way it was practiced before Alexis I convened the Great Moscow Synod and changed the traditions. - Duma chancellory: The first provincial administrative bureau created under Alexis I. In Russian it is called Razryadny Prikaz. - Rurikid: A descendent of the Rurik Dynasty, which dominated seats of power throughout Russian lands for over six centuries before the Romanov Dynasty began. The House of Romanov The House of Romanov was the second major royal dynasty in Russia, and arose after the Rurikid Dynasty. It was founded in 1613 with the coronation of Michael I and ended in 1917 with the abdication of Tsar Nicholas II. However, the direct male blood line of the Romanov Dynasty ended when Elizabeth of Russia died in 1762, and Peter III, followed by Catherine the Great, were placed in power, both German-born royalty. Roots of the Romanovs The earliest common ancestor for the Romanov clan goes back to Andrei Kobyla. Sources say he was a boyar under the leadership of the Rurikid prince Semyon I of Moscow in 1347. This figure remains somewhat mysterious with some sources claiming he was the high-born son of a Rus’ prince. Others point to the name Kobyla, which means horse, suggesting he was descended from the Master of Horsein the royal household. Whatever the real origins of this patriarch-like figure, his descendants split into about a dozen different branches over the next couple of centuries. One such descendent, Roman Yurievich Zakharyin-Yuriev, gave the Romanov Dynasty its name. Grandchildren of this patriarch changed their name to Romanov and it remained there until they rose to power. Michael I The Romanov Dynasty proper was founded after the Time of Troubles, an era between 1598 and 1613, which included a dynastic struggle, wars with Sweden and Poland, and severe famine. Tsar Boris Godunov’s rule, which lasted until 1605, saw the Romanov families exiled to the Urals and other remote areas. Michael I’s father was forced to take monastic vows and adopt the name Philaret. Two impostors attempting to gain the throne in Moscow attempted to leverage Romanov power after Godunov died in 1605. And by 1613, the Romanov family had again become a popular name in the running for power. Patriarch Philaret’s son, Michael I, was voted into power by the zemsky sober in July 1613, ending a long dynastic dispute. He unified the boyars and satisfied the Moscow royalty as the son of Feodor Nikitich Romanov (now Patriarch Philaret) and the nephew of the Rurikid Tsar Feodor I. He was only sixteen at his coronation, and both he and his mother were afraid of his future in such a difficult political position. Michael I reinstated order in Moscow over his first years in power and also developed two major government offices, the Posolsky Prikaz (Foreign Office) and the Razryadny Prikaz (Duma chancellory, or provincial administration office). These two offices remained essential to Russian order for a many decades. AlexisI Michael I ruled until his death in 1645 and his son, Alexis, took over the throne at the age of sixteen, just like his father. His reign would last over 30 years and ended at his death in 1676. His reign was marked by riots in cities such Pskov and Novgorod, as well as continued wars with Sweden and Poland. However, Alexis I established a new legal code called Subornoye Ulozheniye, which created a serf class, made hereditary class unchangeable, and required official state documentation to travel between towns. These codes stayed in effect well into the 19th century. Under Alexis I’s rule, the Orthodox Church also convened the Great Moscow Synod, which created new customs and traditions. This historic moment created a schism between what are termed Old Believers (those attached to the previous hierarchy and traditions of the Church) and the new Church traditions. Alexis I’s legacy paints him as a peaceful and reflective ruler, with a propensity for progressive ideas. Dynastic Dispute and Peter the Great At the death of Alexis I in 1676, a dynastic dispute erupted between the children of his first wife, namely Fyodor III, Sofia Alexeyevna, Ivan V, and the son of his second wife, Peter Alexeyevich (later Peter the Great). The crown was quickly passed down through the children of his first wife. Fyodor III died from illness after ruling for only six years. Between 1682 and 1689 power was contested between Sofia Alexeyevna, Ivan V, and Peter. Sofia served as regent from 1682 to 1689. She actively opposed Peter’s claim to the throne in favor of her own brother, Ivan. However, Ivan V and Peter shared the throne until Ivan’s death in 1696. Peter went on to rule over Russia, and even style himself Emperor of all Russia in 1721, and ruled until his death in 1725. He built a new capital in St. Petersburg, where he built a navy and attempted to wrest control of the Baltic Sea. He is also remembered for bringing western culture and Enlightenment ideas to Russia, as well as limiting the control of the Church.	5,799	common-pile/pressbooks_filtered	https://pimaopen.pressbooks.pub/westciv1/chapter/reading-the-grand-duchy-of-moscow/	pressbooks	pressbooks-0000.json.gz:88687	https://pimaopen.pressbooks.pub/westciv1/chapter/reading-the-grand-duchy-of-moscow/
vb1BX_URw5z_i3Hs	U.S. History	Chapter 11: A Nation on the Move: Westward Expansion, 1800–1860 Review Questions 1. As a result of the Adams-Onís Treaty, the United States gained which territory from Spain? - Florida - New Mexico - California - Nevada 2. The Long Expedition established a short-lived republic in Texas known as ________. - the Lone Star Republic - the Republic of Texas - Columbiana - the Republic of Fredonia 3. For what purposes did Thomas Jefferson send Lewis and Clark to explore the Louisiana Territory? What did he want them to accomplish? 4. A proposal to prohibit the importation of enslaved people to Missouri following its admission to the United States was made by ________. - John C. Calhoun - Henry Clay - James Tallmadge - John Quincy Adams 5. To balance votes in the Senate, ________ was admitted to the Union as a free state at the same time that Missouri was admitted as a slave state. - Florida - Maine - New York - Arkansas 6. Why did the Missouri Crisis trigger threats of disunion and war? Identify the positions of both southern slaveholders and northern opponents of the spread of slavery. 7. Texas won its independence from Mexico in ________. - 1821 - 1830 - 1836 - 1845 8. Texans defeated the army of General Antonio Lopez de Santa Anna at the battle of ________. - the Alamo - San Jacinto - Nacogdoches - Austin 9. How did Texas settlers’ view of Mexico and its people contribute to the history of Texas in the 1830s? 10. Which of the following was not a reason the United States was reluctant to annex Texas? - The United States did not want to fight a war with Mexico. - Annexing Texas would add more slave territory to the United States and anger abolitionists. - Texans considered U.S. citizens inferior and did not want to be part of their country. - Adding Texas would upset the balance between free and slave states in Congress. 11. According to treaties signed in 1818 and 1827, with which country did the United States jointly occupy Oregon? - Great Britain - Spain - Mexico - France 12. During the war between the United States and Mexico, revolts against U.S. control broke out in ________. - Florida and Texas - New Mexico and California - California and Texas - Florida and California 13. Why did Whites in California dislike the Chinese so much? 14. The practice of allowing residents of territories to decide whether their land should be slave or free was called ________. - the democratic process - the Wilmot Proviso - popular sovereignty - the Free Soil solution 15. Which of the following was not a provision of the Compromise of 1850? - California was admitted as a free state. - Slavery was abolished in Washington, DC. - A stronger fugitive slave law was passed. - Residents of New Mexico and Utah were to decide for themselves whether their territories would be slave or free. 16. Describe the events leading up to the formation of the Free-Soil Party.	665	common-pile/pressbooks_filtered	https://pressbooks.online.ucf.edu/osushistory/chapter/review-questions-11/	pressbooks	pressbooks-0000.json.gz:70669	https://pressbooks.online.ucf.edu/osushistory/chapter/review-questions-11/
4VN9bGO0EJfVCQoV	Douglas College Physics 1104 Custom Textbook - Winter and Summer 2020	Chapter 15 Electric Current, Resistance, and Ohm’s Law 15.7 Nerve Conduction–Electrocardiograms Summary - Explain the process by which electric signals are transmitted along a neuron. - Explain the effects myelin sheaths have on signal propagation. - Explain what the features of an ECG signal indicate. Nerve Conduction Electric currents in the vastly complex system of billions of nerves in our body allow us to sense the world, control parts of our body, and think. These are representative of the three major functions of nerves. First, nerves carry messages from our sensory organs and others to the central nervous system, consisting of the brain and spinal cord. Second, nerves carry messages from the central nervous system to muscles and other organs. Third, nerves transmit and process signals within the central nervous system. The sheer number of nerve cells and the incredibly greater number of connections between them makes this system the subtle wonder that it is. Nerve conduction is a general term for electrical signals carried by nerve cells. It is one aspect of bioelectricity, or electrical effects in and created by biological systems. Nerve cells, properly called neurons, look different from other cells—they have tendrils, some of them many centimeters long, connecting them with other cells. (See Figure 1.) Signals arrive at the cell body across synapses or through dendrites, stimulating the neuron to generate its own signal, sent along its long axon to other nerve or muscle cells. Signals may arrive from many other locations and be transmitted to yet others, conditioning the synapses by use, giving the system its complexity and its ability to learn. The method by which these electric currents are generated and transmitted is more complex than the simple movement of free charges in a conductor, but it can be understood with principles already discussed in this text. The most important of these are the Coulomb force and diffusion. Figure 2 illustrates how a voltage (potential difference) is created across the cell membrane of a neuron in its resting state. This thin membrane separates electrically neutral fluids having differing concentrations of ions, the most important varieties being [latex]\boldsymbol{\textbf{Na}^+}[/latex], [latex]\boldsymbol{\textbf{K}^+}[/latex], and [latex]\boldsymbol{\textbf{Cl}^-}[/latex] (these are sodium, potassium, and chlorine ions with single plus or minus charges as indicated). As discussed in Chapter 12.7 Molecular Transport Phenomena: Diffusion, Osmosis, and Related Processes, free ions will diffuse from a region of high concentration to one of low concentration. But the cell membrane is semipermeable, meaning that some ions may cross it while others cannot. In its resting state, the cell membrane is permeable to [latex]\boldsymbol{\textbf{K}^+}[/latex] and [latex]\boldsymbol{\textbf{Cl}^-}[/latex], and impermeable to [latex]\boldsymbol{\textbf{Na}^+}[/latex]. Diffusion of [latex]\boldsymbol{\textbf{K}^+}[/latex] and [latex]\boldsymbol{\textbf{Cl}^-}[/latex] thus creates the layers of positive and negative charge on the outside and inside of the membrane. The Coulomb force prevents the ions from diffusing across in their entirety. Once the charge layer has built up, the repulsion of like charges prevents more from moving across, and the attraction of unlike charges prevents more from leaving either side. The result is two layers of charge right on the membrane, with diffusion being balanced by the Coulomb force. A tiny fraction of the charges move across and the fluids remain neutral (other ions are present), while a separation of charge and a voltage have been created across the membrane. The separation of charge creates a potential difference of 70 to 90 mV across the cell membrane. While this is a small voltage, the resulting electric field ([latex]\boldsymbol{E = V/d}[/latex]) across the only 8-nm-thick membrane is immense (on the order of 11 MV/m!) and has fundamental effects on its structure and permeability. Now, if the exterior of a neuron is taken to be at 0 V, then the interior has a resting potential of about –90 mV. Such voltages are created across the membranes of almost all types of animal cells but are largest in nerve and muscle cells. In fact, fully 25% of the energy used by cells goes toward creating and maintaining these potentials. Electric currents along the cell membrane are created by any stimulus that changes the membrane’s permeability. The membrane thus temporarily becomes permeable to [latex]\boldsymbol{\textbf{Na}^+}[/latex], which then rushes in, driven both by diffusion and the Coulomb force. This inrush of [latex]\boldsymbol{\textbf{Na}^+}[/latex] first neutralizes the inside membrane, or depolarizes it, and then makes it slightly positive. The depolarization causes the membrane to again become impermeable to [latex]\boldsymbol{\textbf{Na}^+}[/latex], and the movement of [latex]\boldsymbol{\textbf{K}^+}[/latex] quickly returns the cell to its resting potential, or repolarizes it. This sequence of events results in a voltage pulse, called the action potential. (See Figure 3.) Only small fractions of the ions move, so that the cell can fire many hundreds of times without depleting the excess concentrations of [latex]\boldsymbol{\textbf{Na}^+}[/latex] and [latex]\boldsymbol{\textbf{K}^+}[/latex]. Eventually, the cell must replenish these ions to maintain the concentration differences that create bioelectricity. This sodium-potassium pump is an example of active transport, wherein cell energy is used to move ions across membranes against diffusion gradients and the Coulomb force. The action potential is a voltage pulse at one location on a cell membrane. How does it get transmitted along the cell membrane, and in particular down an axon, as a nerve impulse? The answer is that the changing voltage and electric fields affect the permeability of the adjacent cell membrane, so that the same process takes place there. The adjacent membrane depolarizes, affecting the membrane further down, and so on, as illustrated in Figure 4. Thus the action potential stimulated at one location triggers a nerve impulse that moves slowly (about 1 m/s) along the cell membrane. Some axons, like that in Figure 1, are sheathed with myelin, consisting of fat-containing cells. Figure 5 shows an enlarged view of an axon having myelin sheaths characteristically separated by unmyelinated gaps (called nodes of Ranvier). This arrangement gives the axon a number of interesting properties. Since myelin is an insulator, it prevents signals from jumping between adjacent nerves (cross talk). Additionally, the myelinated regions transmit electrical signals at a very high speed, as an ordinary conductor or resistor would. There is no action potential in the myelinated regions, so that no cell energy is used in them. There is an [latex]\boldsymbol{IR}[/latex] signal loss in the myelin, but the signal is regenerated in the gaps, where the voltage pulse triggers the action potential at full voltage. So a myelinated axon transmits a nerve impulse faster, with less energy consumption, and is better protected from cross talk than an unmyelinated one. Not all axons are myelinated, so that cross talk and slow signal transmission are a characteristic of the normal operation of these axons, another variable in the nervous system. The degeneration or destruction of the myelin sheaths that surround the nerve fibers impairs signal transmission and can lead to numerous neurological effects. One of the most prominent of these diseases comes from the body’s own immune system attacking the myelin in the central nervous system—multiple sclerosis. MS symptoms include fatigue, vision problems, weakness of arms and legs, loss of balance, and tingling or numbness in one’s extremities (neuropathy). It is more apt to strike younger adults, especially females. Causes might come from infection, environmental or geographic affects, or genetics. At the moment there is no known cure for MS. Most animal cells can fire or create their own action potential. In fact, nerve and muscle cells are physiologically similar, and there are even hybrid cells, such as in the heart, that have characteristics of both nerves and muscles. Some animals, like the infamous electric eel (see Figure 6), use muscles ganged so that their voltages add in order to create a shock great enough to stun prey. Electrocardiograms Just as nerve impulses are transmitted by depolarization and repolarization of adjacent membrane, the depolarization that causes muscle contraction can also stimulate adjacent muscle cells to depolarize (fire) and contract. Thus, a depolarization wave can be sent across the heart, coordinating its rhythmic contractions and enabling it to perform its vital function of propelling blood through the circulatory system. Figure 7 is a simplified graphic of a depolarization wave spreading across the heart from the sinoarterial (SA) node, the heart’s natural pacemaker. An electrocardiogram (ECG) is a record of the voltages created by the wave of depolarization and subsequent repolarization in the heart. Voltages between pairs of electrodes placed on the chest are vector components of the voltage wave on the heart. Standard ECGs have 12 or more electrodes, but only three are shown in Figure 7 for clarity. Decades ago, three-electrode ECGs were performed by placing electrodes on the left and right arms and the left leg. The voltage between the right arm and the left leg is called the lead II potential and is the most often graphed. We shall examine the lead II potential as an indicator of heart-muscle function and see that it is coordinated with arterial blood pressure as well. Heart function and its four-chamber action are explored in Chapter 12.4 Viscosity and Laminar Flow; Poiseuille’s Law. Basically, the right and left atria receive blood from the body and lungs, respectively, and pump the blood into the ventricles. The right and left ventricles, in turn, pump blood through the lungs and the rest of the body, respectively. Depolarization of the heart muscle causes it to contract. After contraction it is repolarized to ready it for the next beat. The ECG measures components of depolarization and repolarization of the heart muscle and can yield significant information on the functioning and malfunctioning of the heart. Figure 8 shows an ECG of the lead II potential and a graph of the corresponding arterial blood pressure. The major features are labeled P, Q, R, S, and T. The P wave is generated by the depolarization and contraction of the atria as they pump blood into the ventricles. The QRS complex is created by the depolarization of the ventricles as they pump blood to the lungs and body. Since the shape of the heart and the path of the depolarization wave are not simple, the QRS complex has this typical shape and time span. The lead II QRS signal also masks the repolarization of the atria, which occur at the same time. Finally, the T wave is generated by the repolarization of the ventricles and is followed by the next P wave in the next heartbeat. Arterial blood pressure varies with each part of the heartbeat, with systolic (maximum) pressure occurring closely after the QRS complex, which signals contraction of the ventricles. Taken together, the 12 leads of a state-of-the-art ECG can yield a wealth of information about the heart. For example, regions of damaged heart tissue, called infarcts, reflect electrical waves and are apparent in one or more lead potentials. Subtle changes due to slight or gradual damage to the heart are most readily detected by comparing a recent ECG to an older one. This is particularly the case since individual heart shape, size, and orientation can cause variations in ECGs from one individual to another. ECG technology has advanced to the point where a portable ECG monitor with a liquid crystal instant display and a printer can be carried to patients’ homes or used in emergency vehicles. See Figure 9. PhET Explorations: Neuron Stimulate a neuron and monitor what happens. Pause, rewind, and move forward in time in order to observe the ions as they move across the neuron membrane. Section Summary - Electric potentials in neurons and other cells are created by ionic concentration differences across semipermeable membranes. - Stimuli change the permeability and create action potentials that propagate along neurons. - Myelin sheaths speed this process and reduce the needed energy input. - This process in the heart can be measured with an electrocardiogram (ECG). Conceptual Questions 1: Note that in Figure 2, both the concentration gradient and the Coulomb force tend to move [latex]\boldsymbol{\textbf{Na}^+}[/latex] ions into the cell. What prevents this? 2: Define depolarization, repolarization, and the action potential. 3: Explain the properties of myelinated nerves in terms of the insulating properties of myelin. Problems & Exercises 1: Integrated Concepts Use the ECG in Figure 8 to determine the heart rate in beats per minute assuming a constant time between beats. 2: Integrated Concepts (a) Referring to Figure 8, find the time systolic pressure lags behind the middle of the QRS complex. (b) Discuss the reasons for the time lag. Glossary - nerve conduction - the transport of electrical signals by nerve cells - bioelectricity - electrical effects in and created by biological systems - semipermeable - property of a membrane that allows only certain types of ions to cross it - electrocardiogram (ECG) - usually abbreviated ECG, a record of voltages created by depolarization and repolarization, especially in the heart Solutions Problems & Exercises 1: 80 beats/minute	2,761	common-pile/pressbooks_filtered	https://pressbooks.bccampus.ca/practicalphysicsphys1104/chapter/20-7-nerve-conduction-electrocardiograms/	pressbooks	pressbooks-0000.json.gz:43354	https://pressbooks.bccampus.ca/practicalphysicsphys1104/chapter/20-7-nerve-conduction-electrocardiograms/
hNsSDJVuQmNHeCwE	Round worms in poultry : life history and control / by W.B. Herms and J.R. Beach.	By W. B. HERMS AND J. R. BEACH Round worms, while among the most abundant and widespread intestinal parasites of fowls, may be easily controlled. Methods for treatment of affected birds and the prevention of further spread and infestation are outlined in the pages following. Flocks infested with round worms are exceedingly unprofitable. The birds are emaciated, unthrifty, appear unkempt and suffer from diarrhea or constipation. Young fowls are most severely affected. To combat successfully and to eradicate round worms, it is desirable that one recognize the worms and understand their life history as well as have a knowledge of the mode of spread from fowl to fowl. The round worm, Ascaris inflexa, when full grown is about one millimeter (%5 inch) in diameter near the middle, tapering at both ends, the mouth end terminating in three circular lips or papillae. The worms are yellowish to pinkish white and measure from 55 to 80 mm. (about 214 to 314 inches) in length in the female and from 40 to 55 mm. (about iy2 to 2^4 inches) in the male. These parasites inhabit the lower part of the small intestine of the fowls and often occur in enormous numbers, indeed they may be so abundant as to literally fill the lumen as shown in figure 1. LIFE HISTORY OF THE WORM The adult worms deposit vast numbers of very minute eggs in thr intestine of the infested bird. The eggs are only visible with the aid of a microscope. They pass out of the intestine of the bird with the droppings, are very resistent to dryness and ordinarily do not hatch until taken into the alimentary canal of the next fowl. There is some evidence that eggs may hatch in the droppings under certain condi- tions. Infection is brought about by means of food or drink which has been contaminated with egg-laden droppings. Thus one infested bird may soon infect an entire flock. In examining the intestine of an infested fowl it will be seen that the larval worms occur mainly at the gizzard end and that the worms become longer at the lower end of the intestine; thus the mature worms are found at the lower end, except when present in large numbers, in which case the entire intestine ma}^ be filled as though stuffed with straw. Development from newly hatched larvae to full-grown males and females is attained in from three to four weeks. If infection has lasted the required length of time the droppings of an infested fowl will be seen to harbor great numbers of the tiny worm eggs. CONTROL It is evident that a campaign to control the round worms involves both treatment of the fowl in order to expel the worms, and disinfection and sanitation of the coops and runways to prevent reinfection. An extensive series of experiments was conducted by one of us ( J. R. B.) in order to test the value of certain anthelmintics and other remedies, such as powdered areca nut, powdered pomegranate root bark, turpentine, gasoline, iron sulphate and tobacco. These were given both alone and in various combinations, in the form of pills or mixed with the food. A physic consisting of either Epsom salts or Glauber's salts was given either together with or following the administration of the drug. For these experiments lots of from 6 to 12 fowls were used, and kept in cages provided with wire net bottoms to exclude the possibility of their becoming reinfected and to enable better observations of the results. Areca nut, although highly recommended by many, proved of little value either when given in the form of a pill or mixed with the mash. Few worms were expelled and postmortem examinations after a few doses were given, showed many of the worms still in the intestines. Furthermore, the fowls would not eat the mash containing areca nut unless they were starved for several days and then ate very sparingly. Powdered pomegranate root bark gave somewhat better results and was eaten more readily by the fowls, but is not effective enough to be of value. Turpentine, while in some cases expelling quite a number of the worms, proved valueless in others. Moreover, a number of fowls died from the effects of this treatment. It is also difficult to induce the birds to eat food treated with turpentine. Openings made in the wall of the intestine show extent of infestation. Tobacco stems, when finely chopped, steeped in water for two hours and mixed with the mash, were readily eaten by the fowls and gave uniformly good results. The fowls which were very badly infested with round worms, were, in most instances, entirely free from these parasites after two doses. DIRECTIONS FOR TOBACCO TREATMENT For one hundred fowls take one pound finely chopped tobacco stems ; steep these for two hours in enough water to keep them covered, mix this liquid, also the stems, with ground feed sufficient for one-half the usual feeding. Before this is fed the fowls should be prepared by reducing the feed of the previous evening to one-half the customary ration. On the day of treatment no feed should be given until 2 o'clock p.m., when the medicated mash is fed, care being taken that each fowl gets its share. Two hours later give about one-fourth the usual ration of ground feed mash made with water in which Epsom salts (eleven ounces per one hundred fowls) has been dissolved. The treatment should be repeated in seven days. Chicks may receive the same treatment, the normal ration of food for the different ages taking care of their proportion of tobacco. Epsom salts rather than Glauber's salts is given as a physic for the reason that the former dissolves much more rapidly, makes a permanent solution (the latter crystallizes on standing) and is apparently eaten more readily than is the latter. DISINFECTION OF YARDS The treated fowls must now be removed to yards free from infection, i.e., free from living round worm eggs. In order to ascertain the value of certain chemicals in the destruction of worm eggs the following experiment was conducted. Three brooder yards in which worm-infested fowls had been kept were selected. Microscopic examination of the soil from these yards revealed the presence of large numbers of round worm eggs to a depth of two inches below the surface. No eggs could be demonstrated in soil removed from a greater depth. swept up and hauled away. One of the yards was then sprinkled with a 1 to 1000 solution of bichloride of mercury (corrosive sublimate, one ounce to eight gallons of water), and the other with a 5 per cent solution of copper sulphate (blue stone). The third yard was not treated. It was found that at least one gallon of the disinfectant for every ten square feet of ground was necessary to penetrate the soil to a sufficient depth, namely, two inches. doubtful, hence it is not recommended for this purpose. In addition to the yards, the houses connected therewith were also thoroughly cleaned and disinfected as above and fitted with roosts, beneath which a wire netting was placed so as to exclude fowls from the droppings. examination of certain individuals, and assuming the rest to be so, these were divided into two equal lots, one placed in the yard treated with bichloride of mercury and the other in the untreated yard. (No fowls were placed in the yard treated with copper sulphate). The birds in the treated yard increased in size rapidly, while those in the untreated yard showed no material improvement in condition nor increase in size. At the end of three weeks certain of the poorest looking birds in the treated lot were examined by post mortem examination and found to be absolutely free from round worms, while a similar examination of birds from the untreated yards showed in their intestines many round worms in all stages of development. as easily with an ordinary sprinkling can. Persons using the bichloride of mercury must take into account its very poisonous nature. Open vessels of the solution must not be accessible to dogs, cats, poultry or other domesticated a7iimals. Keep vessels (wood receptacles should be used) containing the disinfectant well covered and properly labelled "poison." TO HANDLE BROODER CHICKS It is of great importance to keep brooder chicks free from the worms inasmuch as young growing fowls are more severely affected than are the mature ones, and retarded growth is the result. It is recommended that before the chicks are put in the brooder in the spring all loose dirt in the yards be swept up and removed and the yards sprinkled with a 1 to 1000 solution of bichloride of mercury, using at least one gallon for every ten square feet of yard. Great care should be taken to prevent infection from being carried in from other yards on the feet of attendants or by other means. In case the chicks become infected even after all precautions have been taken the yards should be treated as directed above and the fowls given the tobacco treatment. OTHER PRECAUTIONS All sweepings and droppings from the infected yards and houses should be removed to a place to which fowls do not have access. There is evidence that the worm eggs in the droppings may remain alive for at least a year, hence the practice of using infected droppings for fertilizing purposes on ground to which chicks have access is an important cause for repeated worm infection. The exact length of time eggs may remain alive in a compost heap is a matter which must be determined by further experiment; however, it is believed that the droppings should be allowed to lie in a compost heap for at least a Size Grade for Ripe Olives. The Calibration of the Leakage Meter. Cottony Rot of Lemons in California. A Spotting of Citrus Fruits Due to the Action of Oil Liberated from the Rind. Experiments with Stocks for Citrus. Growing and Grafting Olive Seedlings. Phenolic Insecticides and Fungicides. chines. The Practical Application of Improved Methods of Fermentation in California Wineries during 1913 and 1914.	2,209	common-pile/pre_1929_books_filtered	roundwormsinpoul150herm	public_library	public_library_1929_dolma-0001.json.gz:4097	https://archive.org/download/roundwormsinpoul150herm/roundwormsinpoul150herm_djvu.txt
arNcMAfE6Db-jgYR	7.3: Combinations	7.3: Combinations - Distinguish between permutation and combination uses. - Compute combinations. - Apply combinations to solve applications. In Permutations, we studied permutations, which we use to count the number of ways to generate an ordered list of a given length from a group of objects. An important property of permutations is that the order of the list matters: The results of a race and the selection of club officers are examples of lists where the order is important. In other situations, the order is not important. For example, in most card games where a player receives a hand of cards, the order in which the cards are received is irrelevant; in fact, players often rearrange the cards in a way that helps them keep the cards organized. Combinations: When Order Doesn’t Matter In situations in which the order of a list of objects doesn’t matter, the lists are no longer permutations. Instead, we call them combinations . For each of the following situations, decide whether the chosen subset is a permutation or a combination. - A social club selects 3 members to form a committee. Each of the members has an equal share of responsibility. - You are prompted to reset your email password; you select a password consisting of 10 characters without repeats. - At a dog show, the judge must choose first-, second-, and third-place finishers from a group of 16 dogs. - At a restaurant, the special of the day comes with the customer’s choice of 3 sides taken from a list of 6 possibilities. - Answer - - Since there is no distinction among the responsibilities of the 3 committee members, the order isn’t important. So, this is a combination. - The order of the characters in a password matter, so this is a permutation. - The order of finish matters in a dog show, so this is a permutation. - A plate with mashed potatoes, peas, and broccoli is functionally the same as a plate with peas, broccoli, and mashed potatoes, so this is a combination. Decide whether the following represent permutations or combinations: On Halloween, you give each kid who comes to your door 3 pieces of candy, taken randomly from a candy dish. Your class is going on a field trip, but there are too many people for one vehicle. Your instructor chooses half the class to take the first vehicle. $\frac{12!}{{10!}$ $\frac{8!}{{4!4!}$ Counting Combinations Permutations and combinations are certainly related, because they both involve choosing a subset of a large group. Let’s explore that connection, so that we can figure out how to use what we know about permutations to help us count combinations. We’ll take a basic example. How many ways can we select 3 letters from the group A, B, C, D, and E? If order matters, that number is . That’s small enough that we can list them all out in the table below. \| ABC \| ABD \| ABE \| ACB \| ACD \| ACE \| \| ADB \| ADC \| ADE \| AEB \| AEC \| AED \| \| BAC \| BAD \| BAE \| BCA \| BCD \| BCE \| \| BDA \| BDC \| BDE \| BEA \| BEC \| BED \| \| CAB \| CAD \| CAE \| CBA \| CBD \| CBE \| \| CDA \| CDB \| CDE \| CEA \| CEB \| CED \| \| DCA \| DAC \| DAE \| DBA \| DBC \| DBE \| \| DCA \| DCB \| DCE \| DEA \| DEB \| DEC \| \| EAB \| EAC \| EAD \| EBA \| EBC \| EBD \| \| ECA \| ECB \| ECD \| EDA \| EDB \| EDC \| Now, let’s look back at that list and color-code it so that groupings of the same 3 letters get the same color, as shown in Figure 7.9: After color-coding, we see that the 60 cells can be seen as 10 groups (colors) of 6. That’s no coincidence! We’ve already seen how to compute the number of permutations using the formula To compute the number of combinations, let’s count them another way using the Multiplication Rule for Counting. We’ll do this in two steps: Step 1: Choose 3 letters (paying no attention to order). Step 2: Put those letters in order. The number of ways to choose 3 letters from this group of 5 (A, B, C, D, E) is the number of combinations we’re looking for; let’s call that number (read “the number of combinations of 5 objects taken 3 at a time”). We can see from our chart that this is ten (the number of colors used). We can generalize our findings this way: remember that the number of permutations of things taken at a time is . That number is also equal to , and so it must be the case that . Dividing both sides of that equation by gives us the formula below. ${ }_n C_r=\frac{n!}{r!(n-r)!}$ Compute the following: 1. ${ }_8 C_3$ 2. ${ }_{12} C_5$ 3. ${ }_{15} C_9$ - Answer - 1. $ { }_8 C_3=\frac{8!}{3!(8-3)!}=\frac{8 \times 7 \times \mathbf{6} \times \mathbf{5 !}}{\mathbf{3} \times \mathbf{2} \times \mathbf{1} \times \mathbf{5 !}}=8 \times 7=56 $ 2. ${ }_{12} C_5=\frac{12!}{5!(12-5)!}=\frac{12 \times 11 \times 10 \times 9 \times 8 \times 7!}{5 \times 4 \times 3 \times 2 \times 1 \times 7!}=11 \times 9 \times 8=792$ 3. ${ }_{15} C_9=\frac{15!}{9!(15-9)!}=\frac{\mathbf{1 5} \times 14 \times 13 \times \mathbf{1 2} \times 11 \times 10 \times \mathbf{9 !}}{\mathbf{9 !} \times \mathbf{6} \times \mathbf{5} \times 4 \times \mathbf{3} \times \mathbf{2} \times 1}=\frac{14 \times 13 \times 11 \times 10}{4}=5,005$ Compute the following: $_6{C_4}$ $_{10}{C_8}$ $_{14}{C_5}$ - In the card game Texas Hold’em (a variation of poker), players are dealt 2 cards from a standard deck to form their hands. How many different hands are possible? - The board game Clue uses a deck of 21 cards. If 3 people are playing, each person gets 6 cards for their hand. How many different 6-card Clue hands are possible? - Palmetto Cash 5 is a game offered by the South Carolina Education Lottery. Players choose 5 numbers from the whole numbers between 1 and 38 (inclusive); the player wins the jackpot of $100,000 if the randomizer selects those numbers in any order. How many different sets of winning numbers are possible? - Answer - - A standard deck has 52 cards, and a hand has 2 cards. Since the order doesn’t matter, we use the formula for counting combinations: - Again, the order doesn’t matter, so the number of combinations is: - There are 38 numbers to choose from, and we must pick 5. Since order doesn’t matter, the number of combinations is: - A standard deck has 52 cards, and a hand has 2 cards. Since the order doesn’t matter, we use the formula for counting combinations: At a charity event with 58 people in attendance, 3 raffle winners are chosen. All receive the same prize, so order doesn’t matter. How many different groups of 3 winners can be chosen? A sorority with 42 members needs to choose a committee with 4 members, each with equal responsibility. How many committees are possible? The notation and nomenclature used for the number of combinations is not standard across all sources. You’ll sometimes see instead of . Sometimes you’ll hear that expression read as “ choose ” as shorthand for “the number of combinations of objects taken at a time.” Although combinations weren’t really studied in Europe until around the 13th century, mathematicians of the Middle and Far East had already been working on them for hundreds of years. The Indian mathematician known as Pingala had described them by the second century BCE; Varāhamihira (fl. sixth century) and Halayudha (fl. 10th century) extended Pingala’s work. In the ninth century, a Jain mathematician named Mahāvīra gave the formula for combinations that we use today. In 10th-century Baghdad, a mathematician named Al-Karaji also knew formulas for combinations; though his work is now lost, it was known to (and repeated by) Persian mathematician Omar Khayyam, whose work survives. Khayyam is probably best remembered as a poet, with his Rubaiyat being his most famous work. Meanwhile, in 11th-century China, Jia Xian also was working with combinations, as was his 13th-century successor Yang Hui. It is not known whether the discoveries of any of these men were known in the other regions, or if the Indians, Persians, and Chinese all came to their discoveries independently. We do know that mathematical knowledge and sometimes texts did get passed along trade routes, so it can’t be ruled out. The student government at a university consists of 10 seniors, 8 juniors, 6 sophomores, and 4 first-years. - How many ways are there to choose a committee of 8 people from this group? - How many ways are to choose a committee of 8 people if the committee must consist of 2 people from each class? - Answer - - There are 28 people to choose from, and we need 8. So, the number of possible committees is . - Break the selection of the committee members down into a 4-step process: Choose the seniors, then choose the juniors, then the sophomores, and then the first-years, as shown in the table below: Class Number of Ways to Choose Committee Representatives senior junior sophomore first-year The Multiplication Rule for Counting tells us that we can get the total number of ways to complete this task by multiplying together the number of ways to do each of the four subtasks. So, there are possible committees with these restrictions. How many ways are there to choose a hand of 6 cards from a standard deck with the constraint that 3 are $\spadesuit$, 2 are $\heartsuit$, and 1 is $\clubsuit$? Check Your Understanding - Suppose you want to count the number of ways that you can arrange the apps on the home screen on your phone. Should you use permutations or combinations? - Your little brother is packing up for a family vacation, but there’s only room for 3 of his toys. If you want to know how many possible groups of toys he can bring, should you use permutations or combinations? - Compute $_{12}{C_{10}}$. - Compute $_{16}{C_3}$. - You’re planning a road trip with some friends. Though you have 6 friends you’d consider bringing along, you only have room for 3 other people in the car. How many different possibilities are there for your road trip squad? - You’re packing for a trip, for which you need 3 shirts and 3 skirts. If you have 8 shirts and 5 skirts that would work for the trip, how many different ways are there to pack for the trip?	2,319	common-pile/libretexts_filtered	https://math.libretexts.org/Bookshelves/Applied_Mathematics/Contemporary_Mathematics_(OpenStax)/07%3A_Probability/7.03%3A_Combinations	libretexts	libretexts-0000.json.gz:43602	https://math.libretexts.org/Bookshelves/Applied_Mathematics/Contemporary_Mathematics_(OpenStax)/07%3A_Probability/7.03%3A_Combinations
vgrJJvDQNNd0Tlcx	The psychology of advertising in theory and practice; a simple exposition of the principles of psychology in their relation to successful advertising, by Walter Dill Scott ...	WALTER DILL SCOTT, Ph.D. Professor of Applied Psychology and Director of the Psychological Laboratory, Northwestern University; President of the Scott Company, Associate Director of the Bureau of Salesmanship Research, Carnegie Institute of Technology, Former President of the National Association of Advertising Teachers, Colonel, U.S.R.; THE AUTHOR RESPECTFULLY DEDICATES THIS VOLUME TO THAT INCREASING NUMBER OF AMERICAN BUSINESS MEN WHO SUCCESSFULLY APPLY SCIENCE WHERE THEIR PREDECESSORS WERE CONFINED TO CuSTOM. INTRODUCTION Some good "doctoring" was done when men "picked up" their knowledge of medicine from their practice. To-day the state laws require that every physician shall have a basis of theory for his practical knowledge. He must know the exact chemical constituents of the drugs used. He must know the anatomy and the physiology of the human organism. He must be a theoretical man before he can be a practical one. If the laws did not prohibit it, he might pick up a good deal in actual experience and might do a good deal of excellent work. The state laws, however, will not allow us to run chances with such people. We would not call upon an architect to construct a modern office building unless he knew something of the theory of architecture. We would not call upon a lawyer to defend us before the courts unless he knew something of the theory of law. Some states audacities require teachers to pass examinations on the theory of teaching before they are allowed to give instruction. In this day and generation we are not afraid of theories, systems, ideals, and imagination. What we do avoid is chance, luck, haphazard undertakings, parrot or rule-of-thumb action, and the like. We may be willing to decide on unimportant things by instinct or by the flipping of a coin, but when it comes to the serious things of life we want to know that we are trusting to something more than mere chance. of to-day. It is estimated that the business men of the United States are spending $800,000,000 a year in printed forms of advertising. Furthermore one authority claims that seventy-five per cent, of all this is unprofitable. Every business man is anxious that no part of these unprofitable advertisements shall fall to his lot. The enormity of the expense, the keenness of competition, and the great liability of failure have awakened the advertising world to the pressing need for some basis of assurance in its hazardous undertakings. I have attempted to read broadly on the subject of advertising ; I have taken an active part in various kinds of advertising; I have been in intimate contact with manufacturers, salesmen, publishers, professional advertisers, etc., and in all that I have read, and in all my conversations, I have never seen or heard any reference to anything except psychology which could furnish a stable foundation for a theory of advertising. Nothing else is ever suggested as a possibility. Ordinarily the business man does not realize that he means psychology when he says that he "must know his customers' wants — what will^catch their attention, what will impress them and lead them to buy," etc. In all these expressions he is saying that he must be a psychologist. He is talking about the minds of his customers, and psychology is nothing but a stubborn and systematic attempt to understand and explain the workings of the minds of these very people. In Printers^ Ink for October, 1895, appeared the following editorial : Probably when we are a little more enlightened, the advertising writer, like the teacher, will study psychology. For, however diverse their occupation may at first sight appear, the advertising writer and the teacher have one great object in common — to influence the human mind. The teacher has a scientific foundation for Ms work in that direction, but the advertising writer is really also a psychologist. Human nature is a great factor in advertising success, and he who writes advertisements without reference to it is apt to find that he has reckoned without his host. In Publicity^ March, 1901, appeared an article which is even more suggestive than the editorial in Printers^ Ink. The following is a quotation from that article : The time is not far away when the advertising writer will find out the inestimable benefits of a knowledge of psychology. The preparation of copy has usually followed the instincts rather than the analytical functions. An advertisement has been written to describe the articles which it was wished to place before the reader; a bit of cleverness, an attractive cut, or some other catchy device has been used, with the hope that the hit or miss ratio could be made as favorable as possible. But the future must needs be full of better methods than these to make advertising advance with the same rapidity as it has during the latter part of the last century. And this will come through a closer knowledge of the psychological composition of the mind. The so-called "students of human nature" will then be called successful psychologists, and the successful advertisers will be likewise termed psychological advertisers. The mere mention of psychological terms — habit, self, conception, discrimination, association, memory, imagination and. perception, reason, emotion, instinct, and will — should create a flood of new thought that should appeal to every advanced consumer of advertising space. Previous to the appearance of this article (March, 1901) there had been no attempt to present psychology to the business world in a usable form. As far as the advertiser could see all psychologies were written with a purely theoretical end in view. They contained a vast amount of technical material devoid of interest to the layman who struggled through the pages. This condition made it quite difficult for the business man to extract that part of the subject which was of value to him. 4 THE PSYCHOLOGY OF ADVERTISING Several of the leading advertising magazines and advertising agencies sought to father a movement which would result in such a presentation of the subject of psychology that it would be of use to the intelligent and practical advertiser. These efforts on the part of the advertis'ers were successful in stimulating several professional psychologists to co-operate with practical advertisers in applying psychology to advertising. Psychological laboratories were fitted up to make various tests upon advertisements. Elaborate investigations were undertaken and carried through to a successful issue. Psychologists turned to the study of advertisings in all its phases while, on the other hand, intelligent and successful advertisers began to devote attention to a systematic study of psychology. Investigators in the various parts of the country and among different classes of society united in their efforts to solve some of the knotty problems which are ever before the business man who desires publicity for his commodity. Addresses were made before advertising clubs upon the specific topic of the psychology of advertising. The leading advertising journals in America and Europe sought and published articles on the subject. The changed attitude of the advertising world became apparent in a few years. As typical of this change should be considered such statements as the following, taken from Printers' Ink, the issue of July 24, 1907: "Scientific advertising follows the laws of psychology. The successful advertiser, either personally or through his advertising department, must carefully study psychology. He must understand how the human mind acts. He must know what repels and what attracts. He must know what will create an interest and what will fall flat. . . . He must be a student of human nature, and he must know the laws of the human mind." Although italics were not used in the original, the word ^^must" is here put in italics to draw attention to the actual emphasis used by the author. In articles appearing on the subject before the last few years, all persons had spoken of the study of psychology as something which might be brought about in the future. At the present time the writers are asserting that the successful advertiser must study psychology and that he must do it at once. The Bibliography at the end of this volume contains the names of the important contributions made to the psychology of advertising during the last twenty-four years. Although the attitude of the advertising world has changed and even though much has been done to present psychology in a helpful form to the advertisers, the work of the psychologist is not yet available to the business world because the material has not been presented in any one accessible place. Contributions are scattered through the files of a score of American and European publications. Some articles appearing under this head are of minor significance, while others are so important that they should be collected in a place and form such that they would be available to the largest possible number of readers. The psychology of advertising has reached a stage in its development where all that has thus far been accomplished should be reconsidered. The worthless should be discarded and the valuable brought out into due prominence in systematic arrangement. In view of this condition of affairs the author has assumed the pleasing task of systematizing the subject of the psychology of advertising and of presenting it in such a form that it will be of distinct practical value to all who are interested in business promotion. PERCEPTION Between our minds and bodies there is the closest possible relationship. The basis of this relationship is the nervous system. For our present purposes the nervous system may be thought of as consisting of three parts : the brain, the nerve endings (sense organs), and the fibers connecting the brain to these nerve endings. The brain fills the skull and is about one-fortieth of the weight of the entire body. The nerve endings are found in the so-called sense organs, that is, the eyes, the nose, the mouth, the ears, and the skin, and also in the joints and muscles. The nerve fibers are white, threadlike bands, which connect each nerve ending with a particular part of the brain, e.g., the optic nerve is such a bundle of nerve fibers and it connects the various nerve endings in the eye with specific portions of the back part of the brain. The function of the nervous system may be likened to the transmitter, connecting wire, and receiver of a telephone. The similarity is striking in the case of all the nerve endings, but particularly so in the case of the ear. If air waves of a certain quality and of sufficient intensity strike against the transmitter of a telephone, electric currents are set up. They are propagated along the line till they reach the receiver. Here they reassume the form of air waves, and when heard are what we call sound. If air waves, vibrating from fourteen to forty thousand times a second, strike against our ear, a corresponding wave is propagated along the auditory nerve to the brain, where by some unknown process a sensation of sound is awakened which corresponds to the air wave. It will be sufficient to regard this and all other sensations as the direct result of the contact of the outer world with our nerve endings and particularly with our sense organs. The more intense the contact the more intense the sensation, and the quality of the sensation changes with the quality of the contact. The first time a child opens its eyes the ether waves strike against the retina in which the nerve endings are located. Here a current is set up which is propagated to the brain. Then a pure sensation of sight occurs. The nature of the sensation depends entirely on the nature of the light and the current which it sets up. There is no recognition of the light, there is no comparison of it with other sensations, and no fusing of it into former sensations. This is the only really pure sensation of sight which the child will ever have, for its next sensation of sight will be seen in relation to the first sensation. It would be affirming too much to say that the child recognizes or compares this second sensation, but it is quite certain that this second sensation is to a very limited degree modified because of the preceding one. The second experience is added to from the previous one and so is not a pure sensation, but is a perception. A perception is a fusion of sensations with former experiences and embraces comparison, recognition, etc. When the term "perception" is used, special reference is intended to the sensation or sensations which are received through the sense organs and which enter into the total product called a perception. In the case of a young child, perceptions are largely sensational, while former experiences play a small part. When we come into contact with new objects or come into new experiences, we depend upon sensations to form a large part of our perceptions, and the former experiences add relatively a small part to the total product. The first time we saw an orange, we saw it merely as an object of a particular color. Then we touched it, and our perception of it became the perception of an object with a particular color and a particular shape and touch. Then we tasted and smelt it, and each of these new sensations added a new element to our perception. Now, as we see an orange in the distance, we perceive it as an object having a certain color, touch, taste, odor, weight, etc. The only sensation that we have, as the orange is in the distance, is one of sight, but our perception contains these other elements which we add from our former experience. Little by little the elements added to perception by sensation decrease and the elements added by former experience increase till we can get a good perception of an orange even if it is at a great distance from us and if it is in poor light. The process continues and we begin to use symbols for the object and our perceptions are of symbols rather than of objects. One of the first symbols to be perceived is the spoken word, later the^ picture, and then the printed word. The spoken word "orange'' becomes associated with the sight, touch, taste, etc., of the fruit. Whenever we hear the word "orange" we immediately think of the fruit with its special appearance, touch, taste, etc. Our awareness of the absent object is called an "idea," awareness of objects present to the senses is called a "perception." The symbol has no symbolic signification, and becomes the object of the sensation itself unless it typifies to the persons something which they have met in their former experience. Thus a Chinese letter is to me no symbol, but is a group of lines. As I look at it I receive the same sensation that a Chinaman does, but the perception is ditferent because he adds more from his former experience than I do. The letter awakens in his mind an idea of some object or event which is symbolized by the letter. The letter awakens in my mind no idea because it has not been associated in my experience with any object or event. A cartoon of Woodrow Wilson awakens in me an idea of the man rather than a perception of the few curved and straight lines composing the symbolic cartoon. The distinction between the terms ^^perception" and ^^idea^' is very small. If an orange is before me, I perceive the orange. If a symbol of an orange is before me, I may merely perceive the symbol that is present or the symbol may awaken in my mind an idea of the absent orange. Whether we are thinking of present or absent objects,— whether our thought is in the form of perceptions or of ideas, — it is certain that a large part of our thinking is determined by the sensations which come to us through eye and ear, and the other sense organs. We first become acquainted with objects through the sensations which we receive from them, and when we think of them afterward we think in terms of sensations. If I should try to learn about a new kind of fruit which was discovered in Africa, I could acquire the knowledge of it in two different ways: I could secure some of the fruit and then receive all the sensations from it possible. I would look at it, touch it, lift it, smell it, bite it, taste it. This would be the best way to learn of it. If this were impossible I might read descriptions and see pictures of it and then I would think of it (have ideas of it) in terms of touch, weight, smell, and taste which were taken from former experiences in which similar objects were present to my senses. Whether we think by means of perceptions or by means of ideas, the original material of thought and the forms of thought come to us in sensations. The original, easiest, and surest method of acquiring knowledge is through perceptions, in which the sensations play a leading part. In many instances the object of thought cannot be present to the senses and, furthermore, the processes of thought are made more rapid by substituting symbols for the original. Thus, early in the history of the race, a spoken language was developed in which spoken words were symbols for objects of thought. Later, a pictorial writing was invented in which crude portraits were made to symbolize objects. The latest products of civilized humanity in this direction are, first, more perfect portraits land, second, a form of printed language in which the original symbolic spoken word is represented by a sym]t>ol. This second form is the most convenient and is the one in ordinary use, but it should be observed that our printed words are nothing but symbols of symbols. The printed word is an uninteresting thing in itself and is only used because it assists perception on account of its simplicity and ease of manipulation. It is easy to describe a scene or a commodity and to reduce the description to printed form that will be accessible to thousands. It would be extremely difficult to deliver the scene and the commodity directly to these same people. The description and illustration are, however, not so clear, distinct, and interesting as is the original thing described The great danger with the printed symbol is that it will lose in perspicuity and interest what it gains in convenience. The printed word has almost no interest for us in itself. It becomes interesting only in so far as it symbolizes interesting things to us. The more the printed page has to say and the easier it is for us to interpret it, the more interesting it becomes. Whether fortunately or unfortunately, the advertiser is compelled to rely on symbols in exploiting what he has to offer. He cannot, ordinarily, provide the possible customer with that which he has to offer and thus allow him to become acquainted with the goods in the normal and direct way. He is compelled to substitute the symbol for the thing symbolized. He has a choice between two kinds of symbols — printed words and pictorial illustrations. The first form of writing was picture writing, but was abandoned because it was not so convenient as are the phonetic characters now in use. Picture writing could not be written or read so easily and quickly as the writing in the characters now in use and it was therefore discarded. According to the standard of ease of interpretation, all forms of type must be judged. Type forms must not be regarded as a production of artistic demands, but as a product of the demands of convenience. Hundreds of styles of "artistic type" have been brought forth, but they have not remained in use, for they are confusing to the eye and are not artistic in the full sense of the term. Those forms of type and of illustration best perform their proper functions which are so easy of interpretation that they are not noticed at all. There is no advantage in emphasizing the symbol, but there is a great advantage in emphasizing the thing symbolized. In using printed forms, the adver- tiser supplies a very small part to the total idea whicli lie desires to create, and he should therefore make this little mean as much as possible. A series of experiments were carried on to determine whether white or black type made the more attractive display in magazine advertisements. Experiments were made with over five hundred persons. The background for the white type was gray in some cases, but in most cases it was black. The results show that the ordinary reader is more likely to notice display type which is black than a display type of the same sort which is white. A series of laboratory experiments were made on the same subject. Specially prepared pages were shown for one-seventh of a second. On part of the sheets black letters on white background and white letters on black background were shown. In other cases one half of the sheet had a black background, with words in wiiite type, and the other half of the sheet had a white background with words in black type. Scores of cards were constructed in which all the possible combinations of white and black were made and shown to a number of persons for such a short space of time that no one could perceive all there was on any sheet. Under these circumstances the subjects s;aw what first attracted their attention and what was the easiest to perceive. It seems quite certain that, other things being equal, tliose advertisements will be the most often read which are printed in type which is the most easily read. The difference in the appearance of the type in many cases may be so small that even persons experienced in the choosing of type may not be able to tell which one is the more legible, and yet the difference in their values may be great enough to make it a matter of importance to the advertiser as to which type he shall use. If the matter of the proper use of type is of importance to the advertiser, it is even more important that he should make a wise use of the illustration, which is the second form of symbol at his disposal. The illustration is frequently used merely as a means of attracting attention, and its function as a symbolic illustration is disregarded. In a few cases this may be wise and even necessary, but when we consider the value of an illustration as a symbol, we are surprised that illustrations are not used more extensively as well as more judiciously. The first form of writing, as stated above, was picture writing, and the most simple and direct form of graphic representation is through the picture and not through the printed word. At a single glance we can usually read about four words; that is to say, the width of perception for printed words is about four. At a single glance at an illustration we can see as much as could be told in a whole page of printed matter. The width of perception for Illustrations is very much more extensive than it is for printed forms of expression. The illustration may perform either one or both of two functions. It may be a mere picture used to attract attention or it may be an "illustration" and a real aid to perception by assisting the text to tell the story which is to be presented. In the first case it would be called an irrelevant illustration; in the second case it is relevant. There have been several investigations carried on to determine the relative attention value of relevant and irrelevant illustrations. Although the results thus far reached are not so decisive as might be desired, yet it seems certain that the attention value of relevant illustrations is greater than had been supposed and that the irrelevant ^'picture" is frequently not so potent in attracting attention as a relevant illustration would be. Under these circumstances it seems that, in general, the illustration in an advertisement should have the double function of attracting attention and assisting perception. Which one of these functions is the more important might be a profitable question for discussion, but when these two functions can be united in the same illustration, its value is enhanced twofold. Irrelevant illustrations are produced merely because they are supposed to attract attention, when in reality they may attract the attention of no one except the person who designed them and of the unfortunate man who has to pay for them. Similarly there are many illustrations produced and inserted in advertisements because they are supposed to assist the perception. They are supposed to tell the story of the goods advertised and to be a form of argumentation. The designer of the illustration and one familiar with the goods knows what the picture stands for, and so for him it is a symbol of the goods and tells the story of the special advantages of the goods. To one unacquainted with the illustration and with the goods advertised, the illustration is no illustration at all. When we want to teach a child the letters of the alphabet, we do not secure some "sketchy" and artistic looking letters,, but we secure those which are simple in outline and of a large size. We choose those which make a very decided sensation, for in that way we help determine the perception. When the child becomes more familiar with the alphabet, he can read small letters and those which are not printed so plainly. In forming perceptions there must at first be a large element furnished by sensation, whether the perception be formed from an object directly or indirectly from a symbol. Those who forget this principle are likely to construct illustrations which do not illustrate. Their symbols are only symbols for those who are well acquainted with the goods advertised. As an example of this sort of illustrations we reproduce herewith an illustration from magazine advertising. This advertisement for F. P. C. wax (No. 1) seems to be an attempt to tell a great deal about the goods by means of an illustration. It took me some time to translate it, and after I had interpreted it as far as possible, I showed it to some ladies who were magazine readers. None of them had ever taken the pains to figure it out. One of them thought that it was an advertisement of Bibles. When my attention was called to it, I saw the resemblance between the cut as a whole and the cover of an ordinary Bible. The white space is evidently intended to look like the bottom of an iron and the border containing the words "F. P. C Wax" is intended for a cut of a stick of the wax. None of the ladies had interpreted the cut in that way, but when their attention was called to it, they agreed with me that that was probably what the "artist" had intended. We were unable to interpret the white dots and the heavy black border. To those familiar with the advertisement the sensation aroused by the cut is sufficient to produce the desired perception. It has nothing which it seems to be trying to tell to those who turn over the pages of the magazine, and so does not attract their attention. We notice those illustrations which have something to say and say it plainly. We disregard in general those things which do not awaken in us a perception. The sensation which does not embody itself into a perception is of such little interest to us that we pay no attention to it at all. The advertiser desires to produce certain perceptions and ideas in the minds of the possible customers. The material means with which he may accomplish this end are printed words and illustrations, which in the first instance awaken sensations; these in turn embody themselves into perceptions and ideas. These sensations seem so unimportant that they are frequently ing the desired perceptions and ideas is disregarded. This second advertisement of F. P. 0/ wax (No. 2) appeared several months later than the one given above, and is inserted here to illustrate how an advertisement may be improved in the particular point under discussion. The newer cut is really an illustration. It helps perception by giving a sensation which is more decided and more easily interpreted. It furthermore attracts attention and tells the story better than could be done by any text. The advertiser is so familiar with what he has to offer that he cannot appreciate the difficulty the public has in getting a clear and complete perception by means of his advertisements of the goods advertised. It is almost impossible to err on the side of clearness. A sketchy illustration may appear artistic to the designer, but there is danger that it will be regarded as meaningless scrawls by the laity, and so it will not receive a second thought from them. The text and the illustration should, first of all, be clear and should in every way possible assist the mind of the possible customer in forming a correct idea of the goods being exploited. Anatomy is the science which divides the human body into its constituent parts, and is a completed science when it has all of these parts correctly described and labeled. Physiology is the science which describes and explains the different functions of the human body. It supplements anatomy by showing the function of each of the bones, muscles, and organs, and by showing their mutual relations. In anatomy we divide the body into distinct divisions, and in physiology we discover different functions. We often try to think of mind after the analogy of the body, and by so doing are led into confusion. The attempt has been made to divide the mind into a definite number of separate faculties (anatomy). The function of each faculty has been described as something quite different from the other faculties, and an attempt was made to define these faculties exactly and to describe their functions completely (physiology). The attempt has failed and has been abandoned. The mind is not a bundle of faculties. It is not composed of memory, reason, association, etc., but it is a unit which remembers, reasons, feels, etc. No one function is carried on to the exclusion of all others at any one time. During all of its conscious existence the mind feels, knows, wills, etc., but at certain times it is employed in reasoning more than at others, and at one time it may be feeling more intensely than at others, but no one function ever totally occupies the field. When the mind recognizes an event as having occurred in tlie past, it is said to remember, but feeling, attention, and association of ideas may have entered into this process of memory. No one mental process is a thing existing apart and independent of other processes. The anatomical method can never be applied to the mind. The functions of the mind are not independent activities of the mind, but in every function memory, perception, suggestion, and many other functions play a more or less important part. We have no "apperceiving" faculty which is to be distinguished from all other faculties, and which carries on an independent process. The mind does act in a particular and well-known manner, which we have called "apperception." The term has been used for two centuries, and is applied to a well-known process, or function, of the mind which is of great practical and theoretical importance. It includes sensations, perceptions, assimilation, association, recognition, feeling, will, attention, and other actions of the mind, and yet is a very simple and well-known process. It can best be understood if discussed and illustrated from its various aspects. The first thing to be said about apperception is that it is the act of the mind by which perceptions and ideas become clear and distinct. I may look at my ink bottle on the middle of the table. I see it very clearly and distinctly. I can also see, at the same time, other objects on the table, and even some which are not on it at all. As long as I continue to look at the ink bottle the objects distant from the table are not visible. The ink bottle is very clear and the objects near it are comparatively so ; those a few feet away are very indistinct or entirelv invisible. I am said to apperceive the bottle, but to perceive the more distant objects. Certain parts of the bottle are not noticed particularly, while some of the objects on the table stand out plainly. It is quite evident that ^^clearness" does not draw a set line between the various objects, but there are all grades of clearness, from the most clear to the most obscure. We feel that the mental process connected with the ink bottle and that connected with the other objects are different and yet there is an uninterrupted gradation from one to the other. When considered from this point of view apperception is simply an act of attention, for what we attend to becomes clear and distinct to us, while that which is not attended to remains indistinct. Furthermore, there are all degrees of attention. Certain things demand our greatest attention, while others are entirely disregarded. Most things, however, are of the intermediary class. We pay a certain amount of attention to them, but they might easily receive more or less. Some things catch our attention so slightly (are so slightly apperceived) that we are not aware that we have noticed them at all. I did not know that I had ever noticed the walls of the barber shop which I patronize, but as soon as I entered it recently I knew that changes liad been made, and I missed certain details which I had frequently seen, but to which I had paid so little heed that they were merely perceived and could not be said to have been apperceived at all. The second thing to remark about apperception is that it is more than mere attention. It is attention of a particular kind. Our attention to an object or event is an act of apperception if the attention is brought about by means of the relationship of this object or event to our previous experience. Apperception has been defined as the bringing to hear what has been retained of past experience in such a way as to interpret^ to give weight to the new experience. This aspect of apperception has been most clearly brought out in the following quotation from Dexter and Garlack : "A child who has not learned any physiology, and who has not previously looked through a microscope, looks at a drop of blood under the microscope. He probably says that he sees nothing. "Another child who has, we will suppose, studied botanical sections under the microscope, looks at the same drop of blood and says that he sees some small round bodies. "A third child who has learned a little physiology, looks through the microscope, recognizes the small round bodies as corpuscles, notes that the majority are reddish, looks for and perhaps finds a white corpuscle, and so comes to the conclusion that it is a drop of blood that he sees. "In the three instances everything is the same except the children. The differences in the results of the acts of observation must be due to the differences in the minds of the children. The reason that the third child saw more than the other two was that he was fitted by previous training to see more. In order that we may see a thing properly it is not sufficient that rays of light should come from the object to the eye and nerve vibrations travel along the optic nerve to the brain. The mind must be in a position to interpret, to understand these vibrations. To sensations coming from without the mind adds imagination (i.e.^ image-making) working from within. This combination of action of object on mind and the reaction of mind on object is known as apperception.^^ ception is that it increases our knowledge by gradually adding new elements to pur previous store of experience. In the use of the microscope, as cited above, ^acli child added to its store of knowledge in proportion to the amount of previous training which could be brought to bear at this point. The first child had had no previous training in this or in any related work, and so was unable to profit by this experience. He did not focus his eye correctly, and could not direct his attention to what the third child saw. An object, event, or situation which has no relation to our previous experience fails to attract our attention, — is not apperceived, — makes no impression on us, and adds nothing to our store of knowledge. Nothing is regarded worthy of our consideration which does not relate itself to our previous experience. In fact, we can imagine nothing which is out of relation to all our previous experiences. Things and events are only significant in so far as they signify relationships which we know. The slight difference between the letters "O" and "Q" is immediately noticed by us, but would not be seen by any one unfamiliar with our alphabet. There are many important characteristics about the Chinese alphabet which we never observe, because they mean nothing to us. They are unimportant for us because they do not unite themselves with our previous stock of ideas. We interpret all things by our own standards (our stock of ideas) — we observe only those things which have significance for us, we increase our store of ideas not by adding new and independent ones, but by uniting the old with the new. We are not capable of forming entirely new ideas, but must content ourselves with adding new elements to our stock in trade. All our so-called new ideas are composed very largely of old elements. The practical importance of this subject for the advertiser is found in the three aspects of the process as discussed above. In the first place, some advertisementsnever stand out clearly and distinctly in the minds of the possible customers. We may turn over the pages of a magazine and see every advertisement there, but our seeing may be of the sort of those of whom it was said, "having eyes they see not.'' I frequently turn over £he pages of publications and direct my eyes toward advertisements and hold them there long enough to have noticed all the striking characteristics of them, and yet in ten minutes afterward I do not know that these particular advertisements are in the publication at all. I had perceived them, but had not apperceived them. The designers of these advertisements had not been successful in concentrating my mind on any particular thing which had a special reference to my previous experience, and which would therefore be apperceived by me. We cannot apperceive a large number of things at the same time. An advertisement which is constructed upon the principle that all parts of it should be attractive at the same time will so divide the attention that no part of it will stand out prominently, and so it will not be noticed at all. A superfluity of details should be strenuously guarded against in both the text and the illustration. If a single point of an advertisement is apperceived it serves as an opening wedge for the entire advertisement. If, however, there are too many details the attention may be so distracted that none of it will be apperceived, although it may all be seen (perceived). The things which we perceive do make a slight impression on us, but they are so unimportant in comparison with the things that we apperceive that we may almost disregard them entirely. The second point for the advertiser to consider is that the apperception value (identical with attention value in this case) of the advertisement does not depend so much on what the reader receives from the advertisement, but what he adds to it. Your advertisement and all other printed matter is composed of a few straight lines and" a few curved ones, of a few dots, and perhaps one or more colored surfaces. These, when seen, cause a sensation of sight, but that is the smallest part of the result of your advertisement. These visual sensations are immediately enforced by the previous experience of the reader. The value of your advertisement depends almost entirely on the number and kind of former experiences which it awakens. The advertisement is not a thing which contains within itself the reason for its existence. In and of itself it is perfectly worthless. The aim of the advertisement is to call forth activity in the minds of its readers — and, it might be added, action of a particular sort. The advertisement which is beautiful and pleasing to its designer, and which begets activity in his mind, may be perfectly worthless as an advertisement. The drop of blood in the microscope brought forth no activity on the part of the first child who looked at it, as cited above. The child had nothing in its former experience which was suggested by the appearance of the drop of blood, and so it was not interpreted and was not connected with the child's former life, and so made no impression on him. That which happened to the children in looking through the microscope happens every day to the readers of advertisements. The same advertisement will call forth different amounts of activity from different readers. Some advertisements have a meaning to those who are well acquainted with them, and to such they tell their story accurately and quickly. To some readers they tell a confused or erroneous story ; to others they have nothing to tell at all. As an example of such advertisements we have reproduced the advertisement (No. 1) of Whitman's chocolates. This looks like a very neat advertisement, but it fails at the two crucial points — ^it neither attracts attention nor assists in forming a correct perception of the goods advertised. As a proof of this statement it is but necessary to refer to the result obtained with this advertisement in a series of tests recently made. The magazine containing this advertisement was shown to 516 yonng people between the ages of ten and twenty-five. After they had looked at all the advertisements they were asked to write down all the advertisements which they had noticed and could remember. One girl remembered that she had seen an advertisement of candy, but could not remember whose it was or what the advertisement was. One boy remembered that "Whitman^s candy'^ was advertised, but thought the advertisement had the picture of a lady eating a piece of candy. The first of the two probably referred to Huyler's advertisement (Huyler advertised in the same issue) and the second certainly confused the two advertisements. Besides these two none of the 516 persons noticed the advertisement sufficiently to remember that it was there at all. This second advertisement (No. 2) of Whitman's appeared in a later issue of the same magazine. I have made no tests of this advertisement, but feel sure that if the 516 had seen this instead of the other advertisement a very large per cent, of them would have noticed it and have remembered it. It attracts attention and tells more at a glance than could be told in many well-formed sentences. It would create a desire on the part of many of these young people to send for or to purchase a box of such desirable looking candy. It is an illustration which illustrates by helping perception, and it also attracts attention because it has something to tell. The third thing for the advertiser to observe in connection with apperception is that advancement in knowledge is made by joining the new on to the old. The pedagogical maxim of advancing from the known to the unknown finds its justification here. their previous experience, i.e., they cannot apperceive it. This makes it very difficult to introduce a new article on the market. Old firms find it difficult to introduce a new brand, and new firms find it difficult to get themselves noticed at all. Frequently firms have resorted to questionable means to get the public even to notice them. It seems to be impossible for them to get a hearing for the details of their propositions until they have let the public become familiar with their names and know who they are. The promoters of Omega Oil have been severely criticised for their goose, but the goose has introduced them to the public, and now they are in a position to get a hearing and to present the arguments for their commodity. It is quite possible that the expense of keeping the goose before the public was an unnecessary luxury, but they have been wise in not advancing their argument faster than the public was willing to hear it. They have taken but one step at a time. They first let the public know that there was such a thing as Omega Oil, and they took great pains to make this new fact known, and in doing this they were acting in accordance wdth the principles of apperception. They first gave the public some experience of Omega Oil, and then tried to get the public to interpret their arguments in the light of that previous experience. It is not always necessary or even wise to attempt to present all the arguments for a commodity at a single time. It is frequently wise to carry on an educational campaign and to present single arguments. In this way the mind of the possible customer is not crowded with a lot of new and disconnected facts, but each argument has time to be assimilated and to form a part of his experience, and is called up to strengthen and impress each succeeding argument. In writing an advertisement the public to be reached must be carefully studied. In exploiting a new commodity the writer should ask himself what there is about his goods which will fall into "prepared soil'^ on the part of the reader. The reader must first be appealed to by something which he already knows, and thus activity on his part is awakened, and this activity may be made use of for presenting the new elements, which, if presented at first, would have met with no response whatever/ Nothing should be presented as something absolutely new, but as an improvement or substitute for something which is well known. The reader's interest can be best awakened by appealing to his past experiences. ILLUSIONS OF PERCEPTION If there is anything in the world that we feel snre of, it is that our senses (eyes, ears, etc.) do not deceive us, but that they present the outside world to us just as it is. Some have been so impressed with the truthfulness of their senses that they have discredited all other sources of knowledge and are unwilling to accept anything as true which they cannot see. "Seeing is believing," and nothing is so convincing as our perceptions. Many centuries ago it was discovered that under certain conditions even our senses deceived us. This discovery was emphasized and the certainty of any and all our knowledge was questioned till the extremest sort of skepticism prevailed. Such a condition was abnormal and transient, but it certainly is a great shock to us when we discover that under certain conditions our senses are not to be depended upon. All the sense organs are the product of a long evolution in which the various organs were developed as instruments of communication by means of which we might adjust ourselves to our environments. Of all the sense organs the eye is the most highly developed, and yet it was not one of the first to be developed. It is marvelously well adjusted for the functions which it has to perform, but it has certain weaknesses and defects which are surprising. of some of the most striking illusions of the eye. One of the most glaring of the so-called "optical illusions" is the illusion as to the length of lines. We judge distances by the amount of eye movement which is necessary to look from one extremity of the line to the other. Lines or distances over which the eye moves readily are underestimated, while those over which the eye moves with difficulty are overestimated. No. 1 shows two lines of equal length. The line at the top seems much shorter and the explanation is as given above. The arrowheads which are turned in stop the eye movement before the end of the line is reached. The arrowheads which are turned out invite the eye to go even further than the end of the line. I have conducted experiments with very finely constructed instruments which showed that as I looked at the bottom line my eye moved further than it did when I looked at the upper line. When out walking, we are inclined to judge the distance traversed by the amount of effort we have put forth in covering the distance. Any one who has had occasion to walk on railroad ties knows that the distance which he thought he had covered was much greater than the distance which he had actually covered. In walking on the railroad ties, every tie must be noticed and its distance from the next tie must be roughly estimated. There is a constant starting and stopping which calls for the putting forth of an excessive amount of energy. When we walk over a smooth and well-known path there is no starting and stopping at all, but movement is continuous and easy. In the case of these walks the distance covered is judged according to the amount of energy which the limbs must put forth to cover the distance. A similar illusion occurs when the eye is called upon to judge of distances which, roughly speaking, correspond to the railroad ties and the smooth path. moves over it readily and without any delays. B is a space bounded by two dots broken by three others, and, although the eye seems to run over them smoothly, there is a slight tendency to notice each dot, and this stopping and starting at each dot requires more energy than it does to move the eye over an empty space of the same size. As seen' extents are estimated according to the amount of energy necessary to move the eye over them, B is judged to be greater than A. The other illusions than E or G. In No. 3 the two squares are of eqjial size, but the left-hand one appears to be much the larger. As the eye passes over the left square there is a tendency to stop at each cross line, and these stoppings and startings cause us to overestimate the size of the square. Nos. 2 and 3 are but a few of the examples which might be given to show that filled space is overestimated and that empty space is underestimated. In every case the cause of the illusion is found in the fact that we base our estimation of extents upon the eye movements which are necessary to look over the field or extent being estimated. All eye movements are made by means of the three pairs of muscles which are attached to each eye. They are so adjusted that they can move the eye in any direction, but the pairs of muscles are not symmetrically placed, and as a natural consequence it is harder to move the eyes in certain directions than in others. If you move your eyes from right to left and from left to right, you will observe that it is much easier than it is to move them up and down. Our conclusion from this would be that if we judge distances by eye movement, vertical sides were longer than its horizontal ones. No. 5 combines several different causes of illusions, and the result is very striking. Measurements made along the dotted lines show the horizontal line to be about one-sixth longer than the vertical line. The explanation of this illusion is more difficult to find than that of the figures above given, but it is quite certain that all the explanations given above apply here, and in addition we must mention the "error of expectancy." We expect to see the horizontal arms of a cross shorter than the height of it, and so we are inclined to see it that way even when the reverse is true. The error of expectancy will be more fully discussed in the next chapter. No. 6 shows straight lines which seem to be decidedly warped. The four horizontal lines are two pairs of straight and parallel lines. The explanation of this illusion is that we underestimate the size of large angles and overestimate the size of small ones. Each horizontal line is crossed by a number of oblique lines and each oblique line forms two acute and two obtuse angles with each horizontal line. As we overestimate the size of the acute angles and underestimate the size of the large ones, the straight lines must appear crooked to allow for these misjudgments. No. 7 shows two identical figures, but the lower one appears to be much smaller than the upper one. The explanation of this illusion is somewhat different from the explanation of the other illusions as given above. In comparing the size of two objects we ordinarily judge by the comparative size of adjoining areas. In the figures shown the large side of one is next to the small side of the other. We involuntarily compare these adjoining sides, and so the illusion occurs. There is another class of illusions which do not depend upon eye movement, but upon the way the different rays of light affect the retina of the eye. We "see" objects when the rays of light reflected from them fall upon the retina of the eye. From large objects more light is reflected than from small objects. Because of this we have come to judge objects not only from the eye movement, but also from the size of the object as it is reflected upon the eye. The rays of light reflected from some colors spread themselves out, or "irradiate,'' and so the image of the object as it is reflected in the eye is greater than the image of an object of the same size but of a color which does not irradiate. For this reason white objects appear larger than black ones. The stock buyers of the West are often compelled to guess at the weight of animals. I am told that they always, reduce their "guess" on white animals and add to the apparent size (fl black ones. Nor is this illusion confined to white and black. Red, orange, and yellow objects look larger than objects of the same size which are green and blue. Corpulent people dress themselves in black or in the darker shades of blue or green. Small, thin people dress in white, red, orange, or yellow. Another source of errors is found in the fact which, technically expressed, is that the eye is not corrected for chromatic aberration. The result of this defect in the eye is that certain colors look closer than others. Thus red objects look closer than green ones. I remember looking at a church window which had a red disk in a green background. The red appeared to stand out from the green in such a remarkable manner that I was not satisfied till, after the service was over, I went to the window and felt of it. The red and the green were in the same plane, but, as the red might have stood out, the illusion was not counteracted by my knowledge of the perspective and was very striking. know how to cover defects and to produce the desired appearances. Corpulent ladies are not found wearing checks, nor are tall ladies in the habit of wearing vertical stripes. As far as the writer knows, advertisers have never made a conscious effort to profit by illusions in their illustrations and construction of display. It is not the function of this article to suggest how the principles here enunciated might be applied to any particular concrete case, but the ingenious advertiser will find the application. The Purina Mills put up their goodc in checkerboard packages, which make the packages look larger than they really are. This illusion is illustrated in No. 3. Ordinarily the illustration in advertisements of fountain pens represents the pen in a horizontal position. I have recently noticed some of the illustrations in which the pen is represented in a vertical position. This makes the pen look larger, as is indicated in No. 4. If the designer of an advertisement desires to give the impression of bigness to an article which he is presenting, he might make use of some or all of the illusions given above. The cut of the article might be so constructed that the eye would move completely over it or even beyond it, as is shown in the lower figure of No. 1. It might be of such a nature that the eye would not move over it readily, as is the case with B, D, E, and G in No. 2. It might be checkered like the left-hand square of No. 3. It might have its dimensions indicated by vertical and not by horizontal lines. It might take advantage of the error of expectation, as is shown in No. 5. Its size might be made to appear greater by the introduction of acute angles, as is shown in No. 6, in which the distance between the two parallel lines is increased and decreased by acute and obtuse angles. The cut might be brought into contrast with some other figure which would give the impression of great size, as is done in the upper figure of No. 7. Finally, the part of the cut which is to look large might be colored red, orange, yellow, or white. If several of these principles of illusions could be employed in a single cut the effect would be astonishing. As will be seen, the cause of all illusions of perception is found in some maladjustment of our normal sense organs. The advertiser is perfectly justified in taking advantage of this defect of ours, and in some cases this could be done to advantage. In Evanston, Illinois, two grocery firms are accustomed to advertise on hand-bills which are placed in the morning papers before they are delivered by the carriers. A friend of mine, who was the head of a family, had frequently noticed these bills in his morning paper and, having noticed at some time the name of "Robinson Brothers" on que of the advertisements, had come to the conclusion that all these hand-bills were from Robinson Brothers. On a certain morning Winter's Grocery offered to sell several lines of standard goods at a very great reduction from the ordinary price. As my friend was going down town that morning his wife handed him the hand-bill and asked him to order quite an extensive quantity of the special bargains offered that morning. He took the advertisement, checked off what his wife wanted, and went down town. As he entered Robinson Brothers' store he held Winter's advertisement in his hand and read off to the clerk the order which he was commissioned to make. When the goods were delivered he was taken to task by his wife for ordering the goods at the wrong store and thereby failing to save the special reductions for that day. It so happened that the advertisement was still in his pocket. As he took it out and looked at it again he was very much surprised to see "Winter's Grocery" in plain type at the bottom. It was not comforting to him either to remember the w^ay the clerk had smiled when he had held the advertisement in his hand and ordered the goods. He even believed he remembered that the cashier stopped work and scanned him and the advertisement while the order was being given. jt a niininium of expense, t otibmes perfect on of fit and S-ish , -H Tinsomblcn'if of p-K' Thf •« Is 'o r-h.r biph r'^ic unJc atarso inc< 2ine, the Oneita goods occupied three-fourths of the page and the Munsing goods one-fourth. It seems that there should be no confusion about this, but such has not been the case. The Munsing people received a number of letters of inquiry concerning the Oneita union suits. For persons desiring union suits this full-page advertisement was all supposed to be an advertisement issuing from the manufacturers of the Munsing underwear. An advertising manager of a progressive magazine saw^ this page and, like many other readers, supposed that it was all one. He wrote to the Munsing people, making them rates on the full-page advertisement, and enclosed the page from which the half-tone was made as shown above. Confusions often arise between advertisements which present the most dissimilar kinds of goods. It might seem surprising that the advertisements for portable houses should be confused with the advertisement of pens, but the following illustration will show how naturally such an error could occur : In the reduced reproduction of the full-page advertisement (No. 2) the Conklin Pen Company occupies the upper right-hand quarter page and the lower lefthand quarter page. The upper right-hand quarter is of such a nature that it arrests the reader's attention as he turns over the page. It is of such an indefinite nature that it does not direct the attention to anything in particular, but merely arrests it and causes one to look dowm. It does not draw attention .to the lower left-hand quarter more than it does to the lower righthand quarter. Under these circumstances the lower quarter which appeals to the reader the most strongly receives the most attention. We may for the present assume that the two lower quarters are equally attractive. Under these circumstances it will depend upon the reader himself as to whether he will see the portable houses or the pens. If he has been thinking of portable houses — if he wants a portable house — ^his attention will immediately be attracted by the advertisement of Mershon & Morley, and he will take it for granted that Merslion & Morley have used the entire right-hand half of the page. This conclusion is not merely hypothetical, for Mershon & Morley have positive proof as to very many such confusions and they are of the opinion that they have received as much benefit Company has. Department store advertising lead^ to very many more illusions of apperception than are ordinarily detected. Mandel Brothers of Chicago advertised a special brand of writing paper one morning and during the day Mar- shall Field & Company received forty orders for this brand from people who believed that Field's and not MandePs were advertising it. Field's roughly estimated that they receive as many as thirty orders weekly which are known to be due to illusions of apperception in which Field's receive the benefit of competitors advertising. Of two hat firms of Chicago one puts great emphasis on its own name and address, the other emphasizes the style of the hat sold. For convenience' sake we shall call the first firm "A" and the second ^^B." Hatter A has made his name so well known that when a possible customer sees an advertisement of hats he at once begins to think of A. Last summer Hatter B advertised a particular style of hat very extensively. His name was on all the advertisements, of course. The name, however, was not the important or the emphasized thing. After they had read the advertisement through many persons still supposed that it w^as A's advertisement. Hatter A is not willing to have his name or that of his competitor mentioned, for he does not desire to see the present condition changed. His position can be appreciated when w^e learn that he sold over twenty dozen hats last summer to persons who thought they were getting tlie hat which they had seen advertised by B. I have frequently observed that people misread advertisements. In some cases the mistakes are astonishing. After a young lady had completed "looking through" a magazine, I asked her to write down as full an account as possible of some of the advertisements in the magazine. Here is what she wrote: "What sensations are more agreeable after exercise than a hard rub with a towel and a rub with Armour's toilet soap, and a dash of water? Armour's soap may not be very valuable, but it is very refreshing after exercise. Armour's soap may be bought at any store at five or ten cents a bar." What she had read was the following : "What sensations are more agreeable than those following some good, quick exercise, a rub with a rough towel, a scrub with Ivor}^ soap and a dash of cold water? . . . If the Ivory soap is not positively essential, it is at least delightfully cleansing," etc. I asked several hundred persons to write down a description of the advertisements which they had just read. This confusion of Armour's and Ivory soap is but one of scores of similar confusions w^hich I discovered. All those present were much interested in the structure and functions of the brain. Many of them, at first sight, saw nothing unusual about the picture, but observed the position of the various convolutions and fissures of the brain. Later it dawned upon them that it was not a photograph of the brain at all, but was a group of naked babies. I have since that time shown the picture to various per- to see the babies at once. The first time I saw this photograph of a brain I did not notice the babies for several seconds ; then for some time I could see it as either a brain or a group of babies. Now I find that I cannot see it as a brain at all, but every time I look at it I see the babies and there is scarcely any resemblance to a brain there. If I look away from it and think how it should be to represent a duck and then turn my eyes upon it, behold — it is a duck. If I think how it should be to represent a rabbit and then look at it, it ceases to look like a duck and is the likeness of a rabbit. The figure itself may represent equally well either a rabbit or a duck, but cannot possibly suggest both to me at the same time. If I continue to look at it steadily for some minutes it changes from a rabbit to a duck and then back to a rabbit. When I see it as one it does not seem possible that it could ever look like the other, for the two things are so totally different in appearance. ticulars. The one given above is seen equally well in either of two ways, and we seem to have no preference as to which way we shall see it. The one given below can be seen in at least four different ways, but we see it much more readily in one way than in any other. The easiest way to interpret this figure is to regard it as a representation of a staircase as seen from above. It is quite possible, however, to see it as a representation of the same stairs as seen from below. This latter interpretation is made easier if you think just how the stairs would look if seen from below, and if at the same time you direct your eye to the point marked "a" in the cut. It is possible to interpret the cut, not as a staircase at all, but as a strip of cardboard bent at right angles like an accordion plait and situated in front of the apparent background. It is difficult to "see" the figure this way. It is still more difficult to see the figure as a plane surface composed of straight lines without any perspective. This fourth interpretation is the one that would apparently be the most natural, for it is the one which takes the cut for just what it is and adds nothing to it. It might be added that the angles in the staircase figure may be seen as right angles, acute angles, or oblique angles. No. 6 is like the previous illustrations in that it can be seen in more than one way, but it is different in that the figure seems to change under the eye more rapidly pearances in a very few seconds. These changes are assisted by moving the eye from one part of the figure to another. In looking at solid figures or bodies our eyes usually rest on the nearest edge or surface. It comes about in this way that the lines at which we look are very likely to appear to be the nearest edge or surface of the solid. No. 7 consists of a group of either six or seven blocks. If it is looked at steadily for some seconds, the blocks seem to fall and to arrange themselves in a new way. If at first there were but six blocks, there may be seven there after they have fallen. Many people find it very difficult to count the blocks, for while they are counting, the number chiJUges. If you look at No. 7a and hold an image of 'it in your mind while you count the blocks in No. 7 you will probably find six blocks. If, however, 3^ou first look at No. 7& and retain its image in your mind you will be able to find seven blocl^s in No. 7. If the cover alone is visible. To some it will appear as if the book was opened toward them and as if two of the pages w^ere visible. If we try to think how a book should look when opened and turned away from us, and if we then look at the figure, it will appear to represent the book of which we are thinking and also in the position in which we imagined it. that one appeared as a solid. If we cover up the shaft and head of the arrow as shown in this figure, we can then see the top of the figure as a book. If we think of it as the end of an arrow it is flat, but if we think of it as a book it immediately appears as a solid drawn in perspective. If I put on red glasses and then look at a landscape, all objects appear red to me. If I put on green glasses all objects appear green. The objects are colored by the glasses which were before my eyes. In a similar way, by apperception, the thoughts which are in my mind color all the objects at ivhich I looh. We see things through our own eyes and with our own minds. This is equivalent to saying that all we see is changed by the thoughts which are in our minds when we look. It is also equivalent to saying that we see everything in relation to our own previous experience. Although the grass is green I am unable to see it as green till I remove the red glasses. The rose may be red, but it will not appear so to me till I take off the green glasses. In a similar way I fail to see the green grass when I am thinking of the red rose and I fail to see the red rose when I am thinking of the green grass, although both are present all the time. We see most easily those things of which we happen to he thinking or of which we have had previous experience, hut we see with difficulty those things of which we have had no previous experience. For the practical advertiser the theoretical discus sion of the illusions of apperception has a special importance, as it assists him to discern the causes of sucli illusions and to avoid them in his advertisements. The principal cause of all illusions of apperception is found in the fact that the mind of the reader is not prepared for the reception of the case as presented. The second cause of such illusions is that the presentation of the case is not as clear and distinct as it should be. The first of these facts is the peculiar and distinctive cause of most illusions of apperception. The reader's mind may be unprepared either because it is distracted by a competing thought or because the material presented is entirely new. The presentation may be lacking in clearness because in some particular it is ambiguous. By observing the part which these two causes played in the illusions given above we are better prepared to understand and therefore to avoid such illusions. The householder who misread Robinson for Winter had his mind preoccupied with the thought of Robinson. Winter had not succeeded in occupying a place in his mind, while Robinson had. On the other hand, Robinson's and Winter's advertisements look as much alike as two peas and neither has a characteristic feature which would help to identify it. The readers of Everybody's Magazine looked at the lower right-hand corner of the page and read "The N. W. Knitting Company, Minneapolis." With this thought in mind they looked at the Oneita goods, but failed to notice that they were not sold by the N. W. Knitting Company. The Oneita people are in part responsible for the illusion in that they allowed their advertisement to appear without an address and on a page with a similar advertisement which has an address. The more recent advertisements of the Oneita union suits have an address given and therefore are not so subject to illusions of this sort. The confusion by which readers supposed that the portable houses were presented by a full half -page advertisement is a typical illusion of apperception. The readers had their minds preoccupied by the thought of portable houses, and so the attention went to portable houses, and not to "The Pen That Fills Itself." The Conklin Pen Company did not make it perfectly clear that the hand was pointing to their space. In the confusion of hats referred ta, Hatter A had made his name so familiar to the residents of this city that when they read a hat advertisement they did it with their minds preoccupied with the thought that it was A's advertisement. It came about in this way that when they read B's advertisement they read it as A's and failed to notice B's name, which was given at the bottom. It is quite possible tliat B might have greatly reduced upon his own name and address. The young lady who misread Armour's for Ivory had been influenced by extensive advertisements of Armour's which had appeared in her town. She had associated the name of Armour and soap so closely together that when she read of soap she naturally assumed that it was Armour's and failed to see Ivory, just as the inexperienced proofreader reads the proof as he thinks it ought to be and fails to observe some of the most glaring errors. It should also be observed that the soap advertisement did not emphasize the name of Ivory at all. The figures given above illustrate the same principles of illusions of apperception, but they make it clearer than any confusion of concrete advertisements can possibly do. In most, if not in all, of the figures the reader can voluntarily preempt his mind with a thought and then can see in the figure that of which he is thinking. He can in this way interpret each figure in two or more ways. By means of these figures we can see the part the mind adds to a sensation when it. interprets a written, printed, or drawn symbol. These figures also show the need of clear and distinct presentation. They aie extremely ambiguous, and can with equal ease be interpreted in two or more ways. With slight changes all of these figures could be remodeled so that it would be much more difficult to interpret them in any way except the one which the author desired. • That firm which does the most and the best advertising is the one that preempts the minds of the possible customers and so gets the benefit of more advertisements than it pays for. The firms that advertise extensively and do not fail to put the proper emphasis on their names and addresses are the firms that profit most by confusions. New firms and firms that put little emphasis on their names and addresses would be much surprised if they knew how many possible customers read their advertisements and still fail to notice who they are. Many advertisers believe that they should put all their emphasis on the quality of the goods. They assume that if any one wants the goods thus presented they will take the trouble to ascertain the brand of the goods, the name of the firm, and its address. Such a theory sounds well, but the instances of confusion cited above indicate the weakness of the theory when applied to specific advertisements. In this chapter we have confined our attention to illusions in which the reader has confused one advertisement or one figure for another. Ordinarily illusions do not go to this extreme, but are confined to confusions and misunderstandings as to the specific arguments of the advertisements. Since we have positive evidence that these extreme illusions are not uncommon, w^e can well believe that illusions of a less extreme but serious nature are of all too frequent occurrence. The number of such illusions would be materially decreased if the writers of advertisements would see to it that the minds of the possible customers are prepared for the argument which they are about to write and if they would present their arguments clearly and distinctly. IMAGERY Yesterday I looked in at a shop window where the current magazines were displayed. I saw the front outer cover of over a score of them. Now, as I sit in my study, miles away from that window, I can still see the magazines with my "mind's eye" ; that is to say, I can form a mental image of the window and the magazines. I can describe some of the covers accurately as to color, shape, type, etc. I know that there were several magazines off to the left side of the window, but all I can see of them now is the barest outline. They are so indistinct that I cannot tell what they are at all. My mental image of them is very indistinct. But recently I was talking with a friend while a company of young people in an adjoining room was playing on the piano and violin and singing college songs. As I sit here I can imagine how my friend's voice sounded ; I can hear in imagination how the piano and the violin sounded ; I can hear in imagination the tunes which they were singing ; that is to say, I can form a mental image of the sounds which I had previously heard. I notice, however, that my mental image is not so distinct and pronounced as the original perception. I cannot form a mental image of some of the notes which I heard from the violin. Only the more striking parts of the tunes seem to be plain, and even they seem to be quite low and of much less volume than the originals. DIFFERENCES IN MENTAL IMAGERY 57 taste of the coffee were at that time very pleasing to me. Now I can imagine how it smelt and tasted, but the images of it are not very vivid and are not strong enough to give me any pleasure in recalling them. Last night I was on the ice playing hockey. The exercise was very vigorous and exciting. At the time I did not stop to think how it felt to "put the puck/' but I must have felt the exertion of my muscles as I performed the act. Now I can form a mental image of the act ; I can feel my muscles as they make the strain necessary for the performance. I was perspiring when I left the pond and soon my woolen underwear became excessively unpleasant. I felt the unpleasant contact on my skin at that time, and now I can form a mental image of the sensation, which is so strong that it makes me want to stop writing to scratch. As is indicated by the examples given above, I can form a mental image of that which I have seen, heard, tasted, smelt, felt (in my muscles), or touched (with my skin) . In general it might be said that we can form a mental image of anything which we have ever perceived. There are many exceptions to this statement, as w^ill be shown later. Almost all of our dreams and reveries and a large part of our more serious thinking are composed of a succession of these mental images of things which we have previously experienced. We cannot see the images in the mind of our neighbor, but we are likely to suppose that his thinking is very much like our own. It was formerly supposed that such was the case. It was assumed that the normal mind could form images of everything which it had experienced. It was further assumed that there were no personal differences as to the clearness and vividness of such mental images. In 1880 Francis Galton discovered that there was a great difference in individuals in their ability to form these mental images. He found that some persons could form mental images which were almost as vivid and strong as the original perception, while for others the past was veiled in indistinctness. Thus, one man could not imagine how his friends looked when he was absent from them ; another could not imagine how a piano sounded when the piano was out of his hearing. Prof. William James, of Harvard University, continued the investigations begun by Mr. Galton. He collected papers from hundreds of persons in which each one described his own image of his breakfast table. One who is a good visualizer writes : "This morning's breakfast table is both dim and bright : it is dim if I try to think of it when my eyes are open upon any object; it is perfectly clear and bright if I think of it with my eyes closed. All the objects are clear at once, yet when I confine my attention to any one object it becomes far more distinct. I have more power to recall color than any other one thing ; if, for example, I were to recall a plate decorated with flowers, I could reproduce in a drawing the exact tones, etc. The color of anything that was on the table is perfectly vivid. There is very little limit to the extent of my images: I can see all four sides of a room ; I can see all four sides of two, three, four, or even more rooms with such distinctness that if you should ask me what was in any particular place in any one, or ask me to count the chairs, etc., I could do it without the least hesitation. The more I learn by heart the more clearly do I see images of my pages. Even before I can recite the lines I see them so that I could give them very slowly, word for word, but my mind is so occupied in looking at my printed page that I have no idea of what I am saying, of the sense of it, etc. When I first found myself doing this, I used to think it was merely because I knew the lines imperfectly, but I have quite convinced myself that I really do see an image. The strongest proof that such is really the fact is, I think, the following : "I can look down the mentally seen page and see the words that commence all the lines, and from any one of these words I can continue the line. I find this much easier to do if the words begin in a straight line than if there are breaks. Example : Those who are poor visualizers are likely to suspect the writer of ^the above paper as exaggerating the vividness of his visual images, yet there is every reason to suppose that there is no exaggeration about it. ber any particular event is not by any distinct images, but a sort of panorama, the faintest impressions of which are perceptible through a thick fog. I cannot shut my eyes and get a distinct image of any one, although I used to be able to a few years ago, and the faculty seems to have gradually slipped away. In my most vivid dreams, where the events appear like the most real facts, I am often troubled with a dimness of sight which causes the image to appear indistinct. To come to the question of the breakfast table, there is nothing definite about it. Everything is vague. I cannot say what I see; could not possibly count the chairs, but I happen to know that there are ten. I see nothing in detail. The chief thing is a general impression that I cannot tell what I do see. The color is about the same, as far as I can recall it, only very much washed out. Perhaps the only color I can see at all distinctly is that of the tablecloth, and I could probably see the color of the wall-paper if I could remember what color it was.'' Every year I ask each of my students in psychology to write out in full a description of his mental image of his breakfast table, a railroad train, and a football game. In these papers are examples of as good and as poor visualizers as those given from the papers collected by Professor James. I have found that there is not only a personal difference in the ability to form visual images, but that the same differences exi«t for the other classes of perceptions. One student who has strong auditory imagery writes as follows : ^^When I think of the breakfast table I do not seem to have a clear visual image of it. I can see the length of it, the three chairs, — though I can't tell the color or shapeof these, — the white cloth and something on it, but I can't see the pattern of the dishes or any of the food. I can very plainly hear the rattle of the dishes and of the silver and above this hear the conversation, also the other noises, such as a train which passes every morning while we are at breakfast. Again in a football game I distinctly hear the noise, but do not see clearly anything or anybody. I hear the stillness when every one is intent and then the loud cheering. Here I notice the differences of pitch and tone." I had read that some people were unable to imagine sounds which they had heard, but it had not impressed me, for I had supposed that such persons were great exceptions. I was truly surprised when I found so many of my students writing papers similar to those from which extracts are here given : "My mental imagery is visual, as I seem to see things and not to hear, feel, or smell them. The element of sound seems practically never to enter in. When I think of a breakfast table or a football game I have a distinct image. I see colors, but hear no sound." writes : "I am not able to state whether I hear the train or not. I am inclined to think that it is a noiseless one. It is hard for me to conceive of the sound of a bell, for instance. I can see the bell move to and fro, and for an instant seem to hear the ding, dong ; but it is gone before I can identify it. When I try to conceive of shouts I am like one groping in the dark. I cannot possibly retain the conception of a sound for any length of time." "When I recall the breakfast table I see it and the persons around it. The number of them is distinct, for there is only one of them on each side of the table. But they seem like mere objects in space. Only when I think of each separately do I clearly see them. As for the table, all I see is a general whiteness, interspersed with objects. I hear nothing at all, and indeed the whole thing is so indistinct it bewilders me when I think of it. My mental imagery is very vague and hazy, unless I have previously taken special notice of what I now have an image. For instance, when I have an image of a certain person, I cannot tell his particular characteristics unless my attention was formerly directed to them.'' Another writes : "There is no sound in connection with any image. In remembering I call up an incident and gradually fill out the details. I can very seldom recall how anything sounds. One sound from the play ^Robespierre,' by Henry Irving, which I heard about two years ago and which I could recall some time afterward, I have been unable to recall this fall, though I have tried to do so. I can see the scene quite perfectly, the position of the actors and stage setting, even the action of a player who brought out the sound." As they think of a football game all the players are standing stock still; they are as they are represented in a photograph. They are in the act of running, but no motion is represented. Likewise, the banners and streamers are all motionless. They find it impossible to think of such a thing as motion. Others find that the motions are the most vivid part of their images. What they remember of a scene is principally movement. One writes : "When the word ^breakfast table' was given out I saw our breakfast table at home, especially the table and the white tablecloth. The cloth seemed to be the most distinct object. I can see each one in his place at the table. I can see no color except that of the tablecloth. The dishes are there, but are very indistinct. I cannot hear the rattle of the dishes or the voices very distinctly ; the voices seem much louder than the dishes, but neither are very clear. I can feel the motions which I make during the breakfast hour. 1 feel myself come in, sit down, and begin to eat. I can see the motions of those about me quite plainly. I believe the feeling of motion was the most distinct feeling I had. When the word ^railroad train' was given, I saw the train very plainly just stopping in front of the depot. I saw the people getting on the train; these people were very indistinct. It is their motions rather than the people themselves which I see. I can feel myself getting on the train, finding a seat, and sitting down. I cannot hear the noise of the train, but can hear rather indistinctly the conductor calling the stations. I believe my mental imagery is more motile [of movement] than anything else. Although I can see some things quite plainly, I seem to feel the movements most distinctly.'' A very few in describing their images of the breakfast table made special mention of the taste of the food and of its odor. I have discovered no one whose prevailing imagery is for either taste or smell. With very many the image of touch is very vivid. They can imagine just how velvet feels, how a fly feels on one's nose, the discomfort of a tight shoe, and the pleasure of stroking a smooth marble surface. It is a well-observed fact that different classes of society think differently and that arguments which would appeal to one class would be worthless with another. A man's occupation, his age, his environment, etc., make a difference in his manner of thinking, and in the motives which prompt him to action. In appealing to people we ordinarily think of these conditions and formulate our argument in accordance with these motives. That is to say, we address ourselves to a particular social or industrial class. The study of mental imagery makes it evident that there are personal differences apart from differences due to environment, but which are inherent in the individual. Some well-educated persons are so destitute of visual images that they are utterly unable to appreciate the description of a scene when it is described in visual terms. Many persons find themselves bored even by Victor Hugo's description of the scene of the battle of Waterloo. To them the whole scene is unimaginable and therefore unintelligible and uninteresting. I have been interested in observing that the authors which are read with universal delight are those who appeal to all the various classes of mental imagery. Dickens, Sir Walter Scott, Tennyson, Washington Irving, and many of the authors who are universally appreciated, appeal to and awaken many auditory images as well as images of taste, smell, touch, and motion; Browning appeals most often and most exclusively to visual images. It is quite certain that a person can best be appealed to through his dominating imagery. A person who has visual images that are very clear and distinct appreciates descriptions of scenes. A person with auditory imagery delights in having auditory images awakened. The same holds true for the other classes of mental imagery. Of all the writings of Washington Irving "The Legend of Sleepy Hollow'' is one of the favorites. One element of strength in this is the manner in which the author succeeds in awakening the different classes of mental imagery in the reader. Take, for example, the following passages, in which the "eye-minded'' reader sees the scene while the "ear-minded" reader hears that which is being described : ^^Not far from this village, perhaps about two miles, there is a little valley, or rather lap of land, among high hills, which is one of the quietest places in all the world. A small brook glides through it, with just murmur enough to lull one to repose; and the occasional whistle of a quail, or tapping of a woodpecker, is almost the only sound that ever breaks in on the uniform tranquility. ... I had wandered into it at noontime, when all nature is peculiarly quiet, and was startled by the roar of my own gun as it broke the Sabbath stillness around and was prolonged and reverberated by the angry echoes.'' As an example of the way in which Washington Irving could awaken images of taste and of odor, examine the following, taken from the same selection : "The pedagogue's mouth watered as he looked upon this sumptuous promise of luxurious winter fare. In his devouring mind's eye he pictured to himself every roasting pig running about with a pudding in his belly and an apple in his mouth ; the pigeons were snugly put to bed in a comfortable pie, and tucked in with a coverlet of crust; the geese were swimming in their own gravy, and the ducks pairing cosily in dishes, like snug married couples, with a decent competency of onion sauce. In the porkers. he saw carved out the future sleek side of bacon and juicy, relishing ham ; not a turkey but he beheld daintily trussed up, with its gizzard under its wing and peradventure, a necklace of savory sausage," etc. This author is not regarded as one of the greatest^ but certainly the fascination for his writings is found in part in the fact that in his imagination he could see the woodland, he could hear the murmur of the brook, he could taste the pies, he could smell the fragrance of the orchards, he could feel the bumps as Ichabod Crane rode the old horse Gunpowder, he could feel the muscle contract in the brawny arms of Brom Bones. Having all these images distinct himself, he depicted them so well that similar images are awakened in us in as far as we are capable of imagining what he described. It is not to be supposed that Washington Irving intentionally tried to awaken in his readers these various classes of images, but he did unconsciously what it might be wise for us to do consciously. An advertiser, as well as any other author, might do well to examine his own writings to see what sort. of images he is appealing to. It is in general best to appeal to as many different classes of images as possible, for in this way variety is given and each reader is appealed to in the sort of imagery in which he thinks most readily and by means of which he is most easily influenced. The young men and women of to-day are accused of being poorer spellers than their parents. The reasons for this may be many, but one has direct bearing upon our subject of discussion. Formerly children in school spelled orally. They saw the word printed in their books; they did more or less writing, and then felt the movements of their hands and arms as they wrote; they were called upon to spell the word in class orally, and so heard how it sounded. They thus had three "cues" for the word — they saw it, they felt it, and they heard it. When they were called upon to spell a word they had all of these three cues to assist them in remembering how it was spelled, i.e.^ to assist them in forming an image of it. Some years ago oral spelling was displaced by written spelling. In this way one of the cues was abandoned, — the oral one, — and it was found that pupils made more mistakes in writing than those who had spelled orally. Because of this fact oral spelling is being brought back to the schoolroom. An attempt is being made to have the scholars see, hear, and feel the word, and, in this way, their spelling will be better than if they omitted one of the three processes. The scholar knows the word better and can form a more distinct image of it if he has these three cues to assist him. hibited his wares. The buyer saw the goods, heard of them, tasted them, smelt them, felt, and lifted them. He tested them by means of every sense organ to which they could appeal. In this way the buyer became acquainted with the goods. His perception of them was as complete as it could be made. In these latter days the market place has given way to the offit^e. The consequent separation of buyer, seller, and commodity made the commercial traveler with his sample case seem a necessity. But, with the growing volume of business, and with the increased need for more economical forms of transacting business, the printed page, as a form of advertisement, has superseded the market place, and is, in many cases, displacing the commercial traveler. In this transition from the market place and the commercial traveler to the printed page, the advertiser must be on his guard to preserve as many as possible of the good features of the older institutions. In the two older forms of barter all the senses of the purchaser were appealed to, if possible, and in addition to this the word of mouth of the seller was added to increase the impressions and to call special attention to the strong features of the commodity. In the printed page the word of mouth is the only feature which is of necessity entirely absent. Indeed, the printed page cannot appeal directly to any of the senses except the eye, but the argument may be of such a nature that the reader's senses are appealed to indirectly through his imagination. One of the great weaknesses of the present-day advertising is found in the fact that the writer of the advertisement fails to appeal thus indirectly to the senses. How^ many advertisers describe a piano so vividly that the reader can hear it? How many food products are APPLICATION OF MENTAL IMAGERY 69 SO described that the reader can taste the food? How many advertisements describe a perfume so that the reader can smell it? How many describe an undergarment so that the reader can feel the pleasant contact with his body? Many advertisers seem never to have thought of this, and make no attempt at such descriptions. The cause of this deficiency is twofold. In the first place, it is not easy in type to appeal to any other sense than that of sight. Other than visual images are difficult to awaken when the means employed is the printed page. In the second place, the individual writers are deficient in certain forms of mental imagery, and therefore are not adepts in describing articles in terms which to themselves are not significant. This second ground for failure in writing effective advertisements will be made clear by the following examples taken from good and from poor advertisements. "Good'' and "poor'' are used here in a very narrow sense. For convenience' sake these advertisements are called good which are good according to the single standard here under consideration. A piano is primarily not a thing to look at or an object for profitable investment, but it is a musical instrument. It might be beautiful and cheap, but still be very undesirable. The chief thing about a piano is the quality of its tone. Many advertisers of pianos do not seem to have the slightest appreciation of this fact. As a first example of this, read the following advertisement (No. 1), in which an entire advertisement of the Emerson piano is reproduced exactly, with the single exception that the word "incubator" is substituted for "piano." of its deficienc}'. In fact, the majority of piano advertisements are equally poor. The following advertisement of the Vose (No. 2) belongs to the same class. In it the word "camera" is substituted for "piano." than an EMERSON costs, you had better buy it — but make sure it is "■ just as good." A reputation for reliable goods is better than a reputation for low prices. Our prices, however, must be right or there would not be to-day over 76,000 Emerson Incubators in use! What has been said of these two advertisements would hold true of the advertisements in the current issues of the magazines of the Gabler piano, and of many others. sages, and would be equally poor if used to advertise any of them. They are not specific, and do not describe or refer in any way to the essential characteristic of a piano. They awaken no images of sound; they do not make us hear the piano in our imagination. By our easy payment plan, every family in moderate circumstances can own a vose camera. We allow a liberal price for old instruments in exchange, and deliver the camera in your house free of expense. You can deal with us at a distant point the same as in Boston. Send for catalogue and full information. depicts the joy derived from the rhythm of music, but it awakens no images of tone. The advertisement represents a Carola as superior to a drum because it is easier to play. The little antiquated advertisement of the Blasius (No. 4) was an attempt in the right direction. The musical scale suggests music specifically; the picture of the piano recalls the sounds of the music to a certain extent; the lady at the piano suggests music, for she is IS first aid and best aid. You who already have a piano of the rarely used type, have gone a long way toward owning an Inner-Player. Your instrument, with a few monthly payments added, would bring to your home " ..ediatelv the Nf odem Piano— the piano which even a child can play — AND PLAY WITH EXPRESSION. The mmHAjnrnm-mmm Piano has two keyboards. On one, you play by hand, as a perfect piano. On the other, inside and out of sight, the eighty-eight flexible fingers strike with the accuracy of a trained pianist, and with the delicate touch of an artist. No other Player-Piano has this Miniature Keyboard. not turning around to be looked at (cf. an advertisement of Ivers & Pond pianos in the current magazines), but is intent upon her playing. The text also uses words whose sole function is to awaken images of sound. These expressions appear in the advertisement: "Excellent tone," "the sweetest tone I ever heard,'' "sweet and The man who cannot appreciate the tone of a musical Instrument, and who can form but indistinct images of musical tones, is not a good man to write the advertisements for a music house. He might improve his style of writing by reading selections in which the author shows by his writing that he hears in imagination what he describes and his descriptions are so vivid that he makes us hear it too. In determining which foods I shall eat it is a matter of some importance to know how the goods are mantlfactured, what the price is, how it is prepared for the table, and whether it is nourishing or harmful to my system. The one essential element, however, is the taste. When I look over a bill of fare I seek out what I think will taste good. When I order groceries I order what pleases and tickles my palate. Under these circumstances all other considerations are minimized to the extreme. is what one demands m a piano. The Packard tone is singularly rich and of great endurance. " Practice " will not destroy it. Becomes ampler and more sympathetic with use. Superior materials and skillful workmanship insure this permanence of tone-loveliness. In advertisements of food products I have been surprised to note that many foods are advertised as if they had no taste at all. One would suppose that the food was to be taken by means of a hypodermic injection and not by the ordinary process of taking the food into the mouth and hence into contact with the organ of taste. The advertisers seem to be at a loss to know what to say about their foods, and so have, in many cases, expressed themselves in such general terms that their advertisements could be applied equally well to almost any product whatever. The two reproduced advertisements (Nos. 6 and 7), taken from recent issues of household periodicals, are samples of such meaningless generalities. Adulterations not permitted. Use of most Improved machinery. Standard ol merit— our watchword. Endless watchfulness during manufacture. have been changed in each case. I would suggest to these firms that they might improve their advertisements by leaving off the name of the goods entirely and then offer a prize to the person who could guess what they were advertisements of, or else offer the prize for the one who should suggest the largest list of goods which could be equally well presented by these advertisements. Some advertisers of food are evidently chronic dyspeptics and take it for granted that all others are in the same condition. They have nothing to say about their foods except that they have wonderful medicinal properties. To me a food which is only healthful savors scribe foods in such a way that we immediately want what they describe. Of all the advertisements in current magazines jjerhaps the one of the National Biscuit Company reproduced herewith (No. 8) presents their product in the most tempting manner. According to this advertisement "Nabisco'' is something to he eaten, and it is presented in such a way that it would seem that one cannot read of it without being convinced that it is good and something that he wants — and the quicker he gets it the better. This advertisement has character and individuality. Its statements could not be applied to anything but foods or, indeed, to anything but Nabisco. They do not say that Nabisco is wholesome, but when I read them I feel sure that Nabisco would agree with me. and it is the organ which gives more "comfortable'' and "uncomfortable" feelings than any other. Having experienced touch, pressure, cold, heat, and the comforts and pains connected with our skin, we should be able No. 10 to imagine such sensations, and to seek the pleasant and to avoid tlfe unpleasant. Some people are very deficient in imagining the sensations which we receive from the skin, and, strange to say, not a few of these deficient individuals have been put in charge of the advertisements which have to do with these very sensations. One of the prominent characteristics of all bodies. Shoes are sold for different prices; therefore the price is to be considered. They are things that wear out sooner or later; we therefore must consider their durability. They are things that we see with our eyes; therefore their appearance — style — must be considered. Lastly, — but not last considered by the purchaser, — shoes come into close contact with our skins, and sensations that are either pleasant or painful result ; we must therefore consider the fit and comfort of the shoe. A very common deficiency in shoe advertisements is found in the failure of the advertiser to imagine the comfort of the shoe advertised, and to express it in his argument. As a typical advertisement of this sort consider the advertisement of the Crawford shoe (No. 9). It might well be the advertisement of a leather pocketbook, if a few insignificant changes were made. In the advertisement of the Crossett shoes (No. 10) the text matter is most excellent. The writer is one who can appreciate the comfort of a good-fitting and easy shoe; he has been able to imagine the sensation, and he has described it so vividly that the reader feels in imagination the comfort of a Crossett shoe. Omega Oil is a liniment that is supposed to increase the pleasant sensations which we receive through the skin. The writer of this advertisement seems to have been able to imagine the uncomfortable feeling of sore feet, and of the comfort which his oil would secure. The artist who drew the sore feet (No. 11) surely could appreciate the situation in a striking manner. The artist does not depict and the author does not describe what he cannot imagine. Omega Oil is not only a thing which can be applied to and felt by the skin, but it is also a thing that can be seen and smelt. To many it might seem a little thing If yoii want to realize how heavy that . pick up something about those weights and see now long your hands and arms «an bear the strain but it does not go far enough The strained, tired-out muscles aivl lignnients call for something strengtheninft just .is your stomach calls for food. found in Omega Oil. Give your feet a good bathing in wanil wafer, and get all the impurities out of th» pores. Then rub the feet thoroughly with On)ega Oil. The Oil will go in through the cleaa open pores, and strengthen and comfort your feet m a manner that will a-^tonil^ you that Omega Oil is green, but that single advertisement, "It's Green" (No. 12), has done a great deal to help the readers to form a distinct image of the liniment. The man who cares but little for odors would not have taken so much space to say that it "smells nice" (No. 13). In these three advertisements and others like them the advertiser of Omega Oil has shown his appreciation of the human mind to which he has been ap- Omega. Oil is its green color. Some people think it is colored green to make it look nice, but that is not so. Omega Oil is green because Nature makes it green It contains a powerful green herb that gives it its color, and it is this same herb that Wops pain in pcople',s bodies. -There are plenty of white, brown and yellow liniments, but there is only one Omega Oil, and' it is green There is nothing like Omega Oil for curing pain, just as there is nothing like the sun for fnkking rcsl daylight. ^ pealing. It may, however, be questionable whether such minor considerations for liniment as color and odor should receive so much emphasis as is given them here. As was shown in the preceding chapter, many people are deficient in certain forms of imagery. Most people can imagine with some degree of satisfaction how things look. Not quite so many can imagine how things sound or feel. Very many have difficulty in imagining how things taste and smell. This would be sufficient ground for appealing especially to visual images if the commodity was primarily a thing of sight. When the objects advertised are things primarily perceived by other senses than the eye, the greatest care should be taken to awaken those more difficult images, i.e., those of sound, touch, taste, smell, etc. The man who is blind and deaf is greatly handicapped. He cannot perceive color or hear sound, and (if always blind and deaf) cannot imagine sights and sounds. The sense organs have been called the windows of the soul. The more sensations we receive from an object the better we know it. The function of the nervous system is to make us aware of the sights, sounds, feelings, tastes, etc., of the objects in our environment. The nervous system which does not respond to sound or to any other sensible qualities is defective. Advertisements are sometimes spoken of as the nervous system of the business world. That advertisement of musical instruments which contains nothing to awaken images of sounds is a defective advertisement. That advertisement of foods which awakens no images of taste is a defective advertisement. As our nervous system is arranged to give us all the possible sensations from every object, so the advertisement which is comparable to the nervous system must awaken in the reader as many different kinds of images as the object itself can excite. It might be well for a young man who expects to make a profession of writing advertisements to make a test of his own mental imagery. If he finds that he is peculiarly weak in visual imagery he should seek employment with a firm that handles goods other than those which are particularly objects of sight, e.g., pictures. The man who cannot imagine how a musical instrument sounds should hesitate to write the advertisements of a musical house. The man who cannot imagine how foods taste will be greatly handicapped in attempting to write advertisements for food products. Forms of mental imagery may, to a limited extent, be cultivated, and, by giving special attention to the sub- ject, one with a weak form of imagery may greatly improve upon his former efforts, in which he followed out his natural bent without considering the forms of mental images which could be appealed to by his particular class of goods. ASSOCIATION OF IDEAS Every one has wondered how it happens that a thought or idea has suddenly and unexpectedly entered his mind. Not infrequently the particular idea had not been entertained for years, — perhaps it had no apparent connection with the present line of thought, — and yet here it is, seemingly unaltered and as distinct as it had been years before. If anything in the world has tlie appearance of lawlessness, it certainly is the flight of thought in these minds of ours. We can go from Chicago to Peking; from the present moment to the building of the pyramids or the creation of the universe. We can jnck out any object or event included within the borders of space or time. We can go from any one of these objects or events to any other in an instant of time, and whole multitudes of them may be passed in review in scarcely more than a single second. It would be difficult to imagine anything less confined and apparently less subject to laws than the human mind. manner in which they think. However hopeless the task may seem at first sight, it ' is nevertheless true that from the time of Aristotle down to the present day great thinkers have been engaged in trying to find laws according to which the mind acts. They have not been content with the surprise which they have felt when an idea has unexpectedly entered their minds, but they have gone further and sought for the laws which regulate this sudden appearance. Much progress has been made, and the mind is gradually being recognized as consistent and law-abiding as are all other things in the universe. In many cases we can readily see why we are thinking of particular things at a specified time. As I walk down a busy street, unless I am oblivious to my surroundings my thought is determined for me by the objects which sm^round me. My eye is caught by an artistically decorated window in which sporting goods are displayed. My mind is fully occupied for the time with the perception of these articles. The perception of one object is superseded by the perception of another, and in most cases nothing but the present objects are thouglit of, and this perception of present objects does not recall to my mind any objects which I liave seen at other times. It happens, however, that as I see a sweater I think of the sweater which I used to wear, and then of the circumstances which attended its destruction. My mind is next occupied with the perception of clothing,- millinery, etc., as these objects, one after the otlier, meet the direct gaze of my eyes. At the sight of shoes I am reminded of my need for a new pair; then of the particular make of shoes which I ordinarily wear; then of the pair which I purchased a few months ago and of the circumstances attending the purchase. So I may go on for hours, and in a large part my thoughts will be limited to the perception of objects and events which surround me, but in certain cases {e.g.y sweater and shoes) the perception suggests a previous experience. In the case of simple perception the mind seems to act under the ordinary laws of cause and effect. The objects on the street affect me and the perceptions are the result. What my objects which affect my sense organs. Under other circumstances the mind seems to be independent of surrounding objects and to supply the food for thought from former experiences. This is especially true in dreams, sleepless nights, and reveries. Its working is clearly seen in all cases where we are not distracted by external objects and do not attempt to direct the thought along any particular line. Some time ago I read President Roosevelt's decision concerning the Sampson- Schley controversy. After retiring for the night I found that I was thinking of the Rocky Mountains, New Orleans, the Boer war, an Evanston dining-room, the siege of Peking, the recent action of the dowager empress, the American army and navy, and then of the Sampson- Schley controversy again. The interesting part of each idea tends to suggest, or to recall to the mind some previous experience with which this interesting part had been previously associated. As I thought of the Sampson- Schley controversy, the interesting thing just then was that it had been reviewed by President Roosevelt. The interesting thing about President Roosevelt just then was that he had hunted in the Rockies. The interesting thing about that was that he had ridden a horse. In a similar manner the horse suggested New Orleans, where recent shipments of horses had been made to South Africa. This suggested the Boer war, this a conversation on war by a young lady who had returned to Evanston from China. She suggested Peking ; Peking suggested the dowager empress; she suggested her recent actions; these changed conditions suggested the American army and navy ; and they suggested Sampsoji and Schley, and they the controversy. As I walk along the street the action of my mind, even when not conlined to bare perceptions, seems different from its action on the sleepless nighf. As far as the association of ideas is concerned, however, the action is practically identical. In the first case the perceptions of external objects (sweater and shoes) are effective in calling up ideas or experiences with which they had formerly been associated. In the second case the ideas are effective in calling up other ideas with which they had formerly been associated. The statement of the law as it applies to both cases and expressed in general terms is: "'Whenever there is in consciousness one element of a previous experience, this one element tends to bring hack the entire experience.^^ Things thought together oj in immediate succession become ^'associated," or welded together so that when one returns it tends to recall the others. The sight of a shoe suggested the entire "shoe experience," in which I had entered a store, purchased a pair of shoes, carried on a conversation with the proprietor, etc. The thought of President Roosevelt suggested an entire "Roosevelt experience," i.e., President Roosevelt mounted on a horse, attired in a particular costume, amid particular scenery, etc. But I had had many other "shoe experiences" and many other "President Roosevelt experiences." How did it happen that the shoe suggested the particular shoe experience which it did, and not tennis shoes which I had purchased recently, or the wooden shoes which I had examined years before? Why did not President Roosevelt suggest his trip to see his sick son, or his African exploration, or his death, or his literary productions? Each "one element in a previous experience" has been one element in many previous experiences. of interest to us. If we knew a person's past history completely, and if we knew the present external stimulus and the present condition of his mind, we could tell with some degree of certainty what the next idea would be which is to enter his mind. The laws upon which this certainty is based are the three following : The first law is that of habit based on repetition. According to this law the idea next to enter the mind is the one which has habitually been associated with [the interesting part of] the one present to the mind. The sight of a shoe, the printed word "shoe," the spoken word "shoe," and the«felt need of a shoe, each calls to my mind this particular make of shoes with which I have been familiar for years. I have perceived a shoe as a "Douglas"; I have seen "Douglas" and "shoe" printed together; I have heard "Douglas" and "shoe" spoken together; I have seen the portrait of Mr. Douglas and a cut of his shoe appearing together; I have met my need for shoes wdth a "Douglas." All these associations have been frequent and have become so welded together with constant use that when shoe enters my mind, it draws its habitual associate, Douglas, with it. The second law is that of recency. If two things have been recently connected in the mindy when one is thought of again it suggests the other also. One day I read and thought of the exportation of horses from New Orleans. I do not know that horses and New Orleans were ever associated in my mind but this single time, but the next day as I thought of President Roosevelt as mounted on a horse, the thought of horse immediately suggested its recent associate, New Orleans. The recency of this association made it effective. If I had read of this exportation a month before instead of on the preceding day, it is not probable that this associate would have been suggested. The third law is that of vividness or intensity. If my present thought has been associated with a thousand different ohjects, that one will he suggested with which it has been most vividly associated. When I thought of the Boer war, war suggested the siege of Peking because the lady who had returned from China described the siege of Peking in such a thrilling manner — war and the siege of Peking were so intensely associated — that when I thought of war, war suggested this particular association. The association between war and Peking was not only vivid, but was also habitual and recent, even if these latter elements do not seem so prominent. Psychologists are practically agreed that these are the three special laws of the association of ideas and that the "idea which shall come next" conforms to these three simple formulae. The law; of habit is very much more important than the other two. When one element has been associated with one experience habitually, with another recently, and with still another vividly, the chances are that the habitual experience (associate) will be recalled. If, however, the one element has been associatecj with a certain experience habitually, recently, and vividly, this one element will certainly call up this particular experience and none of the multitudes of other experiences with which it had been associated. gested whenever his class of goods is thought of. Let the reader of this article test the truthfulness of the preceding analysis. Test it and see whether the laws of habit, recency, and vividness cover all the cases of association of ideas in your own mind. Think over your possible needs in wearing appareh Where would you go to supply that need, and what quality or make would you get? As you think of tliese possible needs what names, brands, or qualities are suggested? Now analyze these ideas and see if they do not all conform to the three law^s given above. You are probably surprised to see how many of the ideas are those which you have habitually associated with that class of goods. Try the same experiment with articles of food, luxury, investment, etc., and you will be convinced that the advertisements which are the most often seen have a great advantage over those which are less often seen. Long years ago you formed the habit of putting your coat on in a particular way. Perhaps you put the right sleeve on first, perhaps the left. You have formed the habit of putting it on just one way and you will put it on just that way as long as you live. If you put on the right sleeve first this morning, you will put it on the same way to-morrow morning and every other morning. Of course you could change and put the left sleeve on first, but you won't do it. Tlie mind forms habits of thought and when they are once established they are controlling factors in the action of the mind. As a boy I associated certain names with certain articles of merchandise. I saw a particular soap advertised in various ways. Perhaps it was used in my home — I am not sure about that. This name and soap were so habitually associated in my mind as a boy that when I think of soap this particular soap is the kind I am most likely to think of even to the present time, although it has not been called to my mind so often of recent years as other kinds of soap. As far as the association of ideas is concerned, tliat advertisement is the most effective which is most often thought of in connection with the line of goods advertised, but the associations formed in youth are more effective than those formed in later years. Their effectiveness is lasting and will still have influence as long as the person lives. Hence goods of a constant and recurrent use might well be advertised in home or even in children's papers, and the advertisements might be so constructed that they would be appreciated by children. Whenever 1 think of photographical instruments I think of one particular make of cameras. If I should feel a need of buying a camera, I would find immediately that I was thinking of this particular make. If I were called upon to recommend a camera, this one would always suggest itself to me first. It is suggested immediately and involuntarily. In my particular case this advertisement of cameras is successful and for me has a decided prestige over all other cameras. If I try to think out the reason why this particular one is suggested whenever I need or think of cameras, it seems to me that it is because it complies with both the laws of habit and vividness. I do not remember to have noticed any advertisement of cameras recently, nor have I had any occasion to think of tliem for some time. I do know, however, that for several years I saw this advertisement repeatedly — therefore it is with me an habitual association. I also remember that at one time I read a booklet published by this company and that it impressed me profoundly— therefore it is for me a vivid association. If you made the test recommended above, you found that in some eases goods were suggested that were not the ones habitually thought of, but those which had been recently in the mind. Perhaps they had only been brought to your attention this single time. Although the effectiveness of habitual associations is all the more lasting the longer the advertisement is maintained, it gradually diminishes unless the repetition is continued. The recent associates are brought back to the mind with the greatest readiness, and in some cases they prevail over the merely habitual. This emi:)hasizes the necessity of keeping up the repetition to make the habitual most effective, to form the most recent associate, and thus take advantage of the prestige gained by former advertising. Only by frequent advertising are the habitual associations formed and the recent associates constantly made. You also noticed in your experiments that certain goods were suggested of which you had not recently thought and of which, perhaps, you had thought but once in your life. This one time you had seen a very striking advertisement, or had heard the goods highly recommended by a friend, or had seen and used the goods. For instance, one vivid and intense association of hats and Smith was so strong that at the very thought of hats Smith's name presented itself too. You thought of Smith and hats at the same time, and the two thoughts were so vivid that they became welded together by the white heat of the mind, and so when hats are in the mind Smith must come with them. This show.s that sometimes doing extraordinary things in advertising may succeed when it is desired to make a great impression and to have the associations formed under this white heat. It may be admitted that this sort of ad- vertising has been successful in some cases. The law is that the mind is in general gradually molded. Lines of thought are developed and not suddenly formed. The advertiser who attempts suddenly to take the world by storm has "to go against nature" and is consequently at a very great disadvantage. The entire subject of association of ideas may be made clearer and more definite if, in conclusion, its action in another concrete case is given. For years I have seen the statement that the Burlington Railroad goes to Colorado. I have thus thought Burlington and Colorado together, and every time they have entered my mind together they have become more tightly welded together, or associated, until now Colorado is no sooner in my mind than I find that Burlington is also there. When I analyze this association to see how it has been formed, I find, in the first place, that for years I have seen the words Burlington and Colorado together. I have thought the two ideas together repeatedly, and the association has become habitual. In the second place, I find that but yesterday I saw the words Burlington and Colorado together and thought the two thoughts together and so the association was recent. In the third place, I remember that some weeks ago I had been attracted by the Burlington advertisement in which a book about Colorado was offered for six cents. This advertisement impressed me, and I gave it a large amount of attention or active thought and so the association became vivid or intense. If the merchant can make his name or brand to be the habitual, recent, and vivid associate with his class of goods^ he will have such a pfestige over all others that his success seems assured. The securing of this result should be one of the aims of the wise advertiser. FUSION Some years ago I was spending my Christmas vacation at my old home. One morning I was sitting in the library reading short stories. While I was reading, jny sister went to the piano and began playing some of the tunes which she had played years before, and which I had particularly enjoyed. I did not notice the fact that she was playing at all, but I thought the stories were peculiarly beautiful. The next day I remarked about them and had occasion to refer to them. I was greatly disappointed upon reading them the second time to find that they were very commonplace and that ordinarily they would not have pleased me at all. If I liad paid strict attention to the short stories alone, they would have proved themselves to be very uninteresting. As it was, I paid partial attention to each and fused the music and the reading into one total impression which was extremely pleasing. On certain occasions when friends are together all have a jolly good time. A spirit of good fellowship reigns, and every one is happy and contented. The stories told are appreciated and applauded. The jokes all seem so fitting and pertinent. Even if they have been heard before, they are so well told and so apropos that they are as good as new. The next day one is often chagrined when he tries to relate the stories and jokes, and to tell why he had enjoyed the occasion so well. The place, the stories, the jokes, the refreshments, the amusement, and the occasion all united their influences to make a total impression. They were fused together, and their total-product was what had so delighted us. Any one of these things taken singly would have been insufficient to produce an3\ pleasant result, but when taken collectively each shines in a borrowed light. If I hold a lead-pencil vertically in my hand directly in front of my nose, the name of the manufacturer printed on the pencil will be barely visible, if it is on the extreme right side of the pencil. If, however, I close my right eye, the name disappears. If I make a mark on the pencil directly opposite the name of the manufacturer and hold the pencil as before, both the mark and the name are visible. If I close the right eye, the name disappears. If I close the left eye, the mark disappears. As I look at the pencil with my right eye I get a slightly different impression than I do when I look with my left eye, and vice versa. We are not conscious of these two partial impressions, for we fuse them into one total impression, which gives us a better perception of the pencil than is contained in the mathematical sum of the two partial perceptions. A discussion of the result of this fusion of the two impressions made upon the two eyes would be out of place at this point, but it might be remarked that among these results are accurate judgments of the distance and of tlie thickness of the pencil. At any point of time we may be receiving impressions of sight through the eyes, impressions of sound through the ears, impressions of hunger or thirst from the body, and at the same time we may be thinking of former experiences. All these impressions, sensations, ideas, etc., are fused together and have no separate existence. Each plays a part in determining the whole conscious impression or condition, but the parts do not exist alone. It is a general law of psychology that all things tend to fuse and only those things are analyzed that must he analyzed. In the beginning we perceive objects as concrete wholes and then later analyze the wholes into parts. If the first animal which a child sees should be a dog, it would see the dog as a very different thing from what it would later appear to him. It would be a dog, but his idea of it would be so indefinite that he would not notice whether it had four or six legs, whether it had ears or trunk, nose or bill, or whether it was white or black. By later experience the child would learn that the dog was of a particular color, had four legs, two ears, that it barked, ate, and that it had certain other peculiarities and characteristics. The expert in natural history and the dog fancier each notice certain things about the dog thiat the rest of humanity never sees at all. We grasp everything as a concrete whole first, and then by later experience we analyze this whole and add to it. The point to be emphasized is that we do not first perceive' the parts and unite them to form the greater wholes, hut that we first perceive the wholes and only after the process of analysis has heen completed do ice perceive the parts. There are certain products of fusion which by most of us are never analyzed at all. This is the case with the sensations which we receive whenever we breathe. With every breath the diaphragm contracts and expands, the muscles raise and lower the ribs, the lungs receive and discharge a volume of air, the air passages in the nose and windpipe enlarge and contract. All these play a part in making the total sensation which we call breathing, but we cannot with ease analyze the different parts. They are fused together, and as it would be of no particular benefit to analyze the product we have never done so, and we never would have known that the feeling was the product of these elements unless we had reasoned it out first. We know of no object which is independent of all other things. In fact, the value of all objects depends upon the relationships which they have to other things. We think of things only in their relations, and these relationships fuse and constitute the object as we know it. Anthracite or bituminous coal," yellow clay and black loam, can all be thought of as pure and clean, but under certain conditions they become dirt. None of these are dirt in themselves, but in certain abnormal positions they are nothing but filth. When bituminous coal is on the face of the coal heaver it is almost impossible to think of it as coal. It has ceased to be coal and has become dirt because of the abnormal environment into which it has come. The manner in which the environment fuses with an article and determines its value is well illustrated by food in a restaurant. The food may be of the very best quality and the preparation may have been faultless, yet if the service is poor, — if the waiter's linen is dirty and his manner slovenly, — the food does not taste good and is not appetizing. You may reason out that the waiter has nothing to do with the preparation of the food and that his linen has not come into contact with it, but all your reasoning will do you but little good. The idea of dirty linen and this particular food are in your mind indissolubly united, and now, instead of thinking of food in the abstract, you are compelled to think of food in this appetizing. The same thing is illustrated in all places of business. Stores and offices have a tone or atmosphere about them, and everything they have to offer is seen through this atmosphere. I heard a gentleman say recently that he had gone to a particular store to bu}^ a certain article. The store was recommended to him and he was convinced that it was the best place to buy the merchandise desired. When he entered the store he found such a shoddy tone to the entire establishment that he could not believe that the goods which were shown him were desirable. If he could have seen the goods in another store he would have purchased them at once, but he could not convince himself that the goods shown him there were what he wanted, so he left without purchasing them. We are not able to look at things impartially and abstractly, but we judge of everything in the light of its environment — it fuses with its environment and the environment becomes a part of it. The principle of fusion is a subject which should be carefully considered in placing an advertisement. If we could think quite analytically and see the advertisement just as it is, and as a thing independent of its environment, it might be profitable to place our advertisements on garbage boxes and in cheap and disreputable publications. As we are constructed, however, such a course would be suicidal, even for a house dealing in disreputable and cheap articles. The medium gives a tone of its own to all tJie advertisements contained in it. Personally I feel inclined to respect any firm that advertises in a high-class magazine, and unless there is some particular reason to the contrary am willing to trust its honesty. I have always regarded handbills as advertised in this way as belonging to the same category. In tlie course of a conversation, a very intelligent lady recently said to me that she never read the advertisements in any of the magazines excepting in her home religious paper. Here she read not only all the reading matter, but all the advertisements as well. I asked her why she read these advertisements, and she said that she knew they could be depended upon. She had the utmost confidence in the editor and believed that he knew every firm advertising, and that by accepting its advertisement and publishing it he thereby gave it his stamp of approval. No advertisement appearing in this periodical w^as compelled to stand on its own merit alone, so far as she was concerned, but had added to it the confidence inspired by this publication. The advertisement and her confidence fused and formed a whole in which the lady never suspected that any other element entered than those which were in the advertisement itself. The lady referred to did not read the advertisements in other magazines as a usual thing. I have seen her turn over the advertising pages of other magazines to see whether there was anything there that interested her. She reads the advertisements in her favorite magazine and merely looks over the others. In choosing the publications in which he should place his advertisement, the advertiser should not only consider the circulation and the kind of circulation, but he should also consider the tone which each publication would add to his particular advertisement. It is well to have a large number of persons read your advertisement ; it is better to have those read it who are interested in it and have the means to purchase the goods advertised; but it is still better to have a large number of the right kind of persons see your advertisement in a publication which adds confidence and recommends it favorably to your prospective customers. Your advertisement will, to a greater or less extent, fuse with the publication in which it appears, and the product will not be your advertisement as it was prepared by you, but as it comes out of the mold into which you inserted it. The statement that a man is known by the company he keeps is not often challenged, and yet the statement would have been equally true if asserted of an advertisement. If a man is seen frequently in the company of rascals, we think at once that he has become a rascal, but do not suppose that he has reformed his associates. The honorable man loses his reputation by associating with dishonorable persons. An honest firm which advertises in a disreputable sheet and brings its advertisement into association with advertisements of a disreputable character lays itself open to suspicion. The firm may be so well known that it would not be greatly injured by such a course, and it might by its presence raise the standard of the other advertisements. Such a work of philanthropy is too expensive and dangerous to recommend itself to the better known firms. If, on the other hand, a disreputable firm should place its advertisement in a high-grade publication and among honest advertisers, it would for a time at least enjoy the confidence inspired by the publication and by the other advertisements. Every honest firm which adver^ tises should insist, however, that all dishonest advertisements be rejected, for, unless this is done, the honest men lose and the dishonest ones gain. The advertisements of a publication are in the mind of the public all classed together, and if it is known that one of them cannot be trusted, all are brought into disrepute. Because of this principle of fusion^ it is imperative that the advertiser should see that the make-up of the publication is not detrimental to his particular advertisement. Your advertisement would be injured, if, in the make-up, your advertisement of diamonds was placed among advertisements of a questionable character. If I should see an advertisement of an investment scheme that guaranteed unusually large profits, I would suspect fraud at once and would assume a skeptical attitude. If the next instant I should read your advertisement of diamonds, I would be suspicious and would hardly know why I was so. If the next moment I should read the advertisement of a medicine that cured all sorts of incurable diseases, my suspicions would be confirmed, and I would be sure that your diamonds were paste. If, on the other hand, I should see your advertisement placed among those which I knew to be reliable, I would be inclined to classify yours with the others, and would think that it was at least worth while to investigate the matter. The cut here shown (No. 1) is a good illustration of the violation of the proper consideration of the principle of fusion in the make-up of the advertisements of a daily paper. In a Chicago daily for June 22, 1902, appeared three partial columns giving announcements of deaths and burials. Inserted in the middle column was this advertisement for Dr. Sleight's fat-reducing tablets. It might be said that this advertisement would attract attention because of its position, but the effect of the atmosphere of death and burials upon the fat-reducing tablets is too apparent to need comment. Many of those who choose illustrations for their advertisements follow the philosophy of the Irish boy who said that he liked to stub his toe because it felt so good when it stopped hurting. Many of us are unable to see how the boy had made any gain after it was all over, but he was satisfied and that was sufftcient. The philosophic disciples of the Irish boy are found in advertisers who have certain things to dispose of which will not do certain harmful things. First they choose an illustration which will make you believe that what they have to sell BXL1,MAN--Imie 18, 1B02. Bntlim L, fcelsVM wife of Aodrew Bellm&n ftnd mother of Mrs. Hkmie fiuneilzke, £dwftrd. JohD uid Cbailet 1802. and alster cf Frank B. Metzingar. Ura A^isflral (rota her late re^dcnce. 4150 Artesian ar., to St. Agnes' Gtarrcb. to Forty-ninth St. and Ashland ar., tbeacaTjy can to Mount Olivet, to-day. Vuneral from family . residence, 6415 XomiKl ar., ,^to-day at 10 a. m. Interment at Mount Hope. CLARK— John 8., June 19, beloved brother of ':<Bry«n H. and Alice Clarit and Mrs. L. 0. Mc- Marguerite Darric (nee Granuau). runaral Monday at »a5 a._.ln. Trom hu late rral»-^ncf, 1154 Bourooy at.. Sj Prtsentatlon CUurcii; theask by carriages to Calvary Cemetery. is just what you do not want, and then in the text they try to overcome this false impression, and to show you that what they have to offer is not so bad after all. Most of us are unable to see how the advertiser has gained, even if he has succeeded in giving us logical proof that his goods are not so bad as we were at first led to think. We are not logically inclined, and we take the illustration and the text and combine the two. The best that the text can do is to destroy the evil effect of the illustration. Of course, when we read in the text that the illustration does not correctly represent the goods, we ought to discard the illustration entirely and think only of the text, but, unfortunately, we are not constructed that way. The impression made by the illustration and that made by the text fuse and form a whole which is the result formed by these two elements. The line of his argument would seem to be the exhibition of a picture of the skull of a person killed by his insect powder. He then confidentially assures you that his The Swan Foantaln Pen etarts wrltliig jDBtaDt U toucbei paper, w'"- ,dyev»n flow of ink. Tbe feed ( Illy adjusted to meet the needt powder is 'non-poisonous to human." Most people who notice the advertisement see the picture of the skull, but fail to see the ^'non^poisonous to human." The ^^ad-smith^' of No. 3 is trying to convince the public that his fountain pen will not blot. He shows us a cut of his pen doing just what he wants us to believe it will not- do. If we could look at the cut, then forget it entirely and read the text without being biased by the cut, this form of argumentation might be successful, but that is not the way in which we think. Advertisement No. 4 apparently illustrates the proprietor of the rug company as an escaped convict. The text makes no reference to this fact, but tries to impress we should deal. Advertisement No. 5 is the advertisement of a sweetsmelling cigar. The way the designer of the advertisement goes about it to convince us that his cigars are all on the hsb. If it's Rngs, that's onr spectaltT; la fact, we make it a point to fur^b homes complete with floor coverings that are proper, and we do not dupU' cate fine patterns. sweet smelling is to show us Uncle Sam smoking a cigar which evidently has a very bad odor. In small type he. asserts that his cigars are not so bad, but I would not have read that part of the advertisement unless I had had an abnormal interest in poor advertisements. Advertisement No. 6 represents the ^^restful racycle," and does so by displaying a lady on such a wheel being chased by an infuriated bulldog. One of the most un- pleasant things that can happen to a bicycle rider, and one of the things which might deter some ladies from buying a bicycle, is this fact that bicycle riders are liable to be chased by dogs. The writer of this advertisement, by means of this illustration, practically tells every pos- annlTersary yott don't want a 'stinkadora.. Do honor (o your country, in' a' d.eJlclouB and sweet smoke on July 4th by smoking one of odr exquisitely! flavored Billy Walton's 6c Straight iod Grand Duchesse Cigars They are tiie t)est cigars 'to be found In twwa and^ aw just what you want for a hT)lIday treat for your friends. Try thein by ftU means. sible customer to hesitate before she buys this wheel, because, if she buys it, she is likely to be chased by dogs. In advertisement No. 7 the author is trying to bring out the point that insects do not infest this particular brand of rolled oats. In his illustration he shows great crowds of insects swarming about it. If you examine the advertisement you see that, although the insects do have a particular liking for this kind of oats, they cannot get at them till the can is once opened. To my mind this brand of rolled oats and insects are so firmly united that I cannot think of the food without thinking of the insects. Ordinarily the Quaker Oats advertisement has been identified by the presence of the good Quaker. He looks strong, hardy, clean, and honest. In No. 8 we have a portrait of a man who is disgusting in appearance. He For Sale by Grocers Everywhere The careful preparation given the contents of this package, justifies the manufacturers in claiming that it will keep indefinitely in good condition, and upon serving, present a flavor and bouquet, unequaled by any cereal ever offered to the public fuses with oats, and the product is something which is not appetizing and is a food wiiich I do not care to taste. I have always thought of Quaker Oats as something particularly clean and healthful, and my idea was determined in part by associating the food with the Quaker. When this advertisement is before me, I think that Quaker Oats are fit to eat only on condition that I abstract the thought of the food from that of this filthylooking specimen of humanity. digestion cannot withstand the weakening effects of laboratory foods. j Only a short-sighted man will deny that natural digestion most be relied on after all for asslmilatiolk ef the food elements which the body demands, — and the better the digestion the better the prospect ot liealth. The way to preserve the strength of natural digestion it to offer it only natural food. parable to the waiter in a restaurant. We know that the waiter does not prepare the food, yet he is the representative of the kitchen, and we will not enter a restaurant if the waiter looks repulsive. In a similar manner we know that the cut in an advertisement has nothing to do with the food advertised, but the cut is food if its representative looks repulsive. All the advertisements here reproduced seem to be co^nstructed in total disregard to the great principle of fusion which plays an important part in all our thinking. In all these advertisements the cut and the text {e.g.y in the first advertisement the deaths and funerals and the tablet advertisement) fuse, and each plays its part in forming the total impression. We are not able to think of the text without thinking of or being influenced by the illustration. The ordinary man and woman are not accustomed to critical logical thinking. They are not accustomed to consider an object or argument on its own merits and independent of all other things. They are more inclined to take objects, arguments, and events in their entirety. They fuse all the impressions of a particular situation into one total impression, and are influenced by events in their totality without being able to analyze the elements which have united to form the w^hole. If those who construct and place advertisements would consider this principle of fusion, they would be more careful in their choice of mediums, in the association of advertisements, in the make-up and in the construction of the individual advertisements. MEMOKY Impressions once received leave traces of themselves, so that, ill imagination, we can live over the same experiences and can recognize them as related to our past. This knowledge of former impressions, or states of mind, which have already once dropped from consciousness, is what is l^nown as memory. I can imagine how the jungles of Africa must look. This is an act of productive imagination. Yesterday I was on the corner of Fifth avenue and Lake street in Chicago. I heard the sliouts of teamsters, the rattle of passing vehicles, and the roar of elevated trains ,^ I saw the people, the wagons, and the cars. To-day I can, in imagination, live over the same experience, and as I do so I recognize the experience as belonging to my past. I am therefore remembering my past experience: As I try to recall the street scene of yesterday I find that many of the details have escaped me. I cannot remember how the teamsters looked nor what sort of cries they were uttering. I remember that there were teamsters and that they w^ere shouting at their horses, but I cannot, in my imagination, see their faces or hear their voices as I did yesterday. In short, my memory has faded, and has faded rapidly. It is not likely that any memory is so vivid as the original experience, neither does it contain all the details of the actual experience. Immediately after crossing the street I could A year hence I shall probably have forgotten all about it. Our memories gradually fade with time. Professor Ebbinghouse, of Germany, was the first to try to find out exactly hoAv fast our memories do fade. Since he published his thesis many others have taken up the work, and his and their results are fairly well established and definite. They have found that our memories are at their best two seconds after the experience has taken place. After two seconds the memory fades very rapidly, so that in twenty minutes we have forgotten more of an experience than we shall forget in the next thirty days. We forget very rapidly during the first few seconds, minutes and hours. What we remember a day is a very small part of our experiences, but it is the part which persists, as the memory fades very slowly after the first day. What we remember for twenty minutes and what we can get others to remember for that time is of great concern, for it is what we and they remember for longer times also. It is not possible for a person with a poor memory to develop a good one, but every one can improve his memory by the observance of a few well-known and thoroughly established principles. The first principle is repetition. If you want to make sure that you will remember a name, say it over to yourself. Repeat it in all the ways possible — say it over aloud, write it, look at it after it is written, think how it sounded w^hen until it has become thoroughly fixed in your mind. The second principle is intensity. If you want to remember a name, pay the strictest possible attention to it. If you apply the first principle ami repeat the name, then you should pay the maximum amount of attention to every repetition. In this way the process of learning will be so reduced that a single repetition may be enough, and still the name may be retained, for a long period of time. The third principle is that of association. The things which we think over, classify and systematize, and thus get associated with our previous experience, are the things which we commit most easily and retain the longest. As a boy at school I learned by repetition that Columbus discovered America in 1492. At that time this was to me an entirely disconnected fact. It was not associated with anything else, and so cost me great effort of attention and frequent repetition before I had it thoroughly memorized. At a later time I was compelled to learn the approximate date of the fall of Constantinople, the application of the compass to navigation, the invention of printing, the time of the activity of Copernicus, Michelangelo, Titian, Dtirer, Holbein, etc. Such a list of unconnected dates would have cost me much unprofitable effort if I had been compelled to learn them separately. As it was, I connected them all with the date of the discovery of America, and saw that these men and these events were all contemporaneous and together made what is known as the Renaissance. are not soon forgotten. A man may have no trouble from forgetting the details of his business or profession, yet may have a poor memory for all events not thus associated. The fourth principle is that of ingenuity. I remember the name of Miss Low, for she is a short woman. I remember a friend's telephone, which is 1391, by thinking how unfortunate it is to have such a number to remember — 13 is supposed to be an unlucky number, and 91 is seven times 13. This method is applicable only to disconnected facts which we find difflculty in remembering by the methods given before. It is, however, a method which was used by the Roman oratojs and has been used more or less ever since. There is probably no one who does not make frequent use of it in attempting to remember names, dates, figures, and similar data. We all appreciate the value of a good memory, and are willing to pay any one w^ho will tell us how to train ours. This condition of affairs has made "memory training" a profitable business for the fakir. It is fairly well established now that one's native retentiveness is unchangeable. One who has an unretentive memory cannot possibly change it by any method of training. All he can do is to improve on his method of acquiring and recording knowledge. one by far of the most importance. The fourth principle is the one of least general application; indeed if an attempt is made to apply it too frequently, it becomes worse than useless, yet it is the principle used by most persons who have "memory train Ing" to sell. MEMORY 115 vertisement so that the reader cannot forget it, we find that the question is answered by the proper application of the principles enunciated above. The advertisement that is repeated over and over again at frequent intervals gradually becomes fixed in the memory of the Wheat. Has been used more than thirty years by thousands of active business men and women, from whom sustained, vigorous application of brain and nenous power is required, promptly relieving the dc pression from overwork, worry, nervous exciteinent, and sleeplessness, increasing activity and vital force by feeding the brain and nerves with the exact food they require for their nutrition and normal action. If not found at DrvogMX aent by maa {$lMfiCROSBY'S COLD AND CATARRH CURB. Tb« best ^emedr In existence for cold In the head and i By mall, 60 cents. but it seems to be effective. This method gailis added effect by repeating one or more characteristic features, and by changing some of the features at each appearance of the advertisement. Thus the reproduced advertisement of Vitalized Phosphites (No. 1) is frequently repeated in identical form. We cannot forget this advertisement, but it has taken too many repetitions to secure the desired results. The reproduced advertisement of Cream of Wheat (No. 2) is but one of a series of advertisements in all of which the colored chef appears prominently. This characteristic feature causes us to associate all of the series, and hence the effect of repetition is secured. At the central feature, but always in a new form. the same time, there is sufficient diversity, because the colored chef is never represented in the same way in any two of the advertisements as they appear from month to month. Similar statements could be made of a host of other excellent advertisements. few examples will serve to make the method plain. Bright colors impress us more than dull ones. The bright-colored inserts and advertisements run in colors are remembered better than others, because they make a greater impression on us. In any experience it is the first and the last parts of it that impress us most and that get fixed most firmly in our memories. The first and the last advertisements in a magazine are the most effective. Likewise the first and the last parts of any particular advertisement (unless very short) are the parts that we remember best. The back cover-page is valuable because when the magazine is lying on a table the back cover-page is likely to be turned up, but in addition to that it is a valuable page because it is likely to be the first or the last seen by most readers. The second cover-page is valuable because it is so likely to be seen first, and even to be seen by those who do not look at the advertisements in the back of the magazine — if such persons still exist! The intensity of the impression which an advertisement makes is dependent upon the response which it secures from the readers. The pedagogue would call this action the "motor response," even though it were nothing more than the writing of a postal card. Such action is vital in assisting the memory of the readers. An advertisement which secures a response sufficient to lead to the writing of a postal card has a chance of being remembered which is incomparably greater than that of other advertisements. The advertisement of Pompeian Massage Cream (No. 3) will not soon be forgotten by those who are induced to send the name of their dealer to the Pompeian Manufacturing Company. Rhymes and alliterations are rhetorical forms which seem to be of great assistance when we attempt to commit verses, and even when we do not want to remember them the rhythm may make such an impression that we can't forget them. The "Spotless Town'' is an illus- There is. much poor advertising being done at the present time in a futile attempt to produce a successful imitation of the "Spotless Town." The rhythm and the' alliteration must be excellent, else they make the whole attempt seem ridiculous, and the advertisement falls flat. Anything humorous or ridiculous — even a pun — is hard to forget. But unless the attempt is successful, the result is ludicrous and futile. Furthermore, that which impresses one person as funny may seem silly to another. The reproduced advertisement of Gold Dust (ISO. 4) seems funny to some, but does not to others. The reproduced advertisement of Rough on Rats (No. 5) impresses some persons as silly, while others think it funny. valuable when well done. That which excites an emotion is not easily forgotten, and hence is a good form of advertising, if it can convince the reason at the same time that it stimulates the feelings. The advertisement of Gold Dust (No. 4) pleases me and convinces me that the product is good. The advertisement of Rough on Rats (No. 5) amuses me because it is so excessively silly. It does not please me, does not convince me of the desirability of the goods. I find that both advertisements have made such" an intense impression on me that they have stuck in my memory, and I see no prospect of being able to forget them soon. The writer of advertisements must consider the principle of association, and ordinarily does so, even if he does it unconsciously. He should present his argument in such a form that it will naturally and easily be asso- elated by the reader with his own former experience. This is best done by appealing to those interests and motives which are the ruling principles of the reader's thinking. Personally, I should forget a recipe for a cake before I had finished reading it, but to a cook it is full of interest, and does not stand out as an isolated fact, but as a modification or addition of something already in his mind. The statement that the bond bears four per cent, interest is not forgotten by the capitalist ; for he immediately associates the bond of which this statement is made with the group of similar bonds, and so the statement is remembered, not as an isolated fact. constantly before his mind. The arguments of an advertisement should be such as are easily associated with the personal interests and with the former experience of the majority of the readers. Here Is the opportunity to give your boy a lesson In the value of money and the growth of interest Stocking Co. (ISo. 6) is in direct violation of this principle. The advertisement was evidently written by a man, and appeals to men as being a good advertisement. It would be remembered by men, and if they were the purchasers of boys' stockings, it would be an excellent advertisement. In reality the men do not buy the stockings, and so the advertisement appeals to those who have nothing to do with the business — except those who pay for the advertisement. manufacturer, but not to a mother : ^^Five per cent, gold bonds/' ^'Clip your coupons and make money," '^Give your boy a lesson in the value of money and the groAvth of interest," "This is one per cent, more than any bank pays, and allows you the use of the principal, allowing you a share of our profits," etc. The principle of ingenuity can liave but an occasional application, but there are instances when it has been employed with great effectiveness. Thus "Uneeda" is a name which cannot be forgotten. It pleases by its very ingenuity, although most of the attempts in this direction have been futile. Thus "Uwanta" is recognized as an imitation, and is neither impressive nor pleasing. "Keen Kutter" is a name for tools which is not easily forgotten. "Syrup of Figs" is a name for a patent medicine which is easily remembered, although the product contains no figs. A tailor in Chicago advertised himself and his shop in such an ingenious way that no one could read his advertisement and forget the essential features of it. His street number was 33, his telephone number was the same. There were 33 letters in his name and address. He sold a business suit for \|33. The number 33 stood out prominently as the striking feature of his advertisement and impressed many as being unique, and at the same time fixed in their minds his name and address, and the cost of his suits. The four principles enunciated above for impressing advertisements on the minds of possible customers are capable of unlimited application, and will not disappoint any; for they are the laws which have been found to govern the minds of all persons as far as their memories are concerned. THE FEELINGS AND THE EMOTIONS We all know what is meant by pleasure and pain, by joy and grief. These feelings and emotions are not better understood after we have attempted to define them. They are known only by experience, and we are all familiar with them. In the present chapter we are interested in the effect which pleasure and pain and the different emotions have upon the mind and the body of the person experiencing them. These effects are not sufficiently recognized and yet they are of special significance to the advertiser. For the sake of brevity we shall use the word "pleasure" not merely to express such simple pleasures as tasting an appetizing morsel, but also to express such pleasurable emotions as joy, love, benevolence, gratitude, pride, etc. The word "pain'' or "displeasure" will likewise be used to express simple painful sensations and also emotions which involve pain, such as fear, hate, jealousy, antipathy, etc. Every pleasurable and every painful experience has a direct reflex effect on the bodily functions and also on the action of the mind. These effects are widespread and important. Some of these changes, even though significant, are not directly detected without the use of delicate recording instruments. Pleasures actually cause the limbs to increase in size, and, accompanying the physical change, is a feeling of expansiveness which depression. Under the influence of pleasure the efficiency of the heart-action is greatly enhanced. This increase of blood supply gives us a feeling of buoyancy and increased vitality, which greatly enhances the already pleasing experience. Displeasure, on the other hand, interferes with the normal action of the heart. This gives us a feeling of sluggishness and depression. Pleasure assists the rhythmical action of the lungs and adds to the depth of breathing. These changes serve but to add to the already pleasing experience. Pain interferes with the rhythm of breathing, makes the lung action less deep, and gives a feeling of being stifled, hindered, and checked in carrying out our purposes. Pleasing experiences, increase our muscular strength and cause us to feel like men. We feel more like undertaking great tasks and have more faith in our ability to accomplish them. Pain decreases muscular strength and gives us a feeling of weakness and lack of confidence. Pleasures not only give greater strength to the voluntary muscles, but they affect directly the action of all the voluntary and involuntary muscles of the body. In pleasure the hands go out from the body, the shoulders are thrown back and the head elevated. We open up and become subject to the influences in our environment. Being pleased with what we are receiving, we become receptive and expand that we may take in more of the same sort. In pain the hands are drawn in towards the chest and the whole body draws in within itself as if to protect itself against outside influences. These actions of the body are reflected in the mental attitude. In pleasure our minds expand. We become extremely sug- gestible, and are likely to see everything in a favorable light. We are prompt to act and confident of success. In pain we are displeased with the present experiences and so withdraw within ourselves to keep from being acted upon. We refuse to receive suggestions, are not easily influenced, and are in a suspicious attitude toward everything which is proposed. When in pain we question the motives of even our friends and only suspicious thoughts are called up in our minds. These brief statements of facts serve to call to the reader's attention the mental attitude in which the person is placed by the influence of pleasure and pain. Keen observers of men have not been slow in profiting by these facts. In ^Tickwick Papers," speaking from the viewpoint of the defendant, Dickens says : "A good, contented, well-breakfasted juryman is a capital thing to get hold of. Discontented or hungry jurymen always find for the plaintiff." Here Dickens expresses the fact that man is not pre-eminently logical, but that his thinking is influenced by his present state of feelings. If the juryman were discontented and hungry, he would be feeling pessimistic and suspicious and would believe in the guilt of the defendant. The modern business man does his utmost to minister to the pleasure of the customers in his store. He knows they will place a larger order if they are feeling happy than if they are feeling otherwise. The American slang expression, "jolly up," means the pleasing by flattery of the one from whom it is desired to obtain a favor. The merchant attempts to please the customer by the appearance of the store, by courteous treatment, and by every other possible method. The same pains must be taken by the advertiser in his attempts to please those to whom his appeals are made. The methods open to the means should be employed most assiduously. In the present chapter the importance of pleasing the advertiser by appealing to his esthetic sense will be emphasized, and suggestions will be given of concrete methods which are available to the advertiser in appealing to the sense of the beautiful. To be beautiful a thing must possess certain characteristics which awaken a feeling of appreciation in. the normal person. It is true that the artistic judgment is not possessed equally by all, or at least it is not equally developed in all. There are, however, certain combinations of sounds which are universally called harmonies and others which are called discords. There are certain combinations of colors which are regarded as pleasing and others which are displeasing. There are likewise certain geometrical forms or space arrangements which are beautiful, and others which are displeasing. The musician knows what tones will harmonize and which ones will not. The man without a musical education does not possess such knowledge, but he appreciates the harmony of tones when he hears it. The colorist knows how to produce pleasing effects with colors. He has acquired this knowledge which others do not possess, although they are able to appreciate his work. The artist knows how to produce pleasing effects with symmetry and proportion of space forms. The uninitiated does not possess such knowledge or ability, although he is able to appreciate the work of the artist and can distinguish it from the work of the novice. Perhaps the simplest thing that could be suggested which would have an element of esthetic feeling connected with it is the bisection of a straight line. It seems almost absurd to suppose that the position of the point of division in a straight line would have anything to do with a feeling of pleasure. Such, however, is certainly the case, but, as might be expected, the esthetic feeling is not very pronounced. As an illustration, look at No. 1. Here we have a series of straight vertical lines divided by short cross lines. Look at the lines carefully and you will probably feel that the lines A, B, and C are divided in a more pleasing manner than F, G, and H. In other words, if a straight vertical line is to be divided into two unequal parts, you prefer to an altogether unimportant discovery. In judging of vertical distances, we overestimate the upper half. For this reason the line E, which is divided into two equal parts, appears to be divided into two slightly unequal parts and the lower section seems to be the smaller. The line D is divided at a point slightly above the middle, but it appears to be divided into two exactly equal parts. Many persons would say that the line D is more pleasing than E, for' D appears to be divided into two equal parts, while E appears as if an unsuccessful attempt had been made to divide the line into two equal parts. Line D seems to be perfectly symmetrical — its two parts appear equal. The symmetry about this division pleases us, and most persons would say that this line, which is divided symmetrically, is more pleasing than A or H, which are not divided symmetrically. The two parts of the lines A, B, C, and H appear too unequal and the two parts of line E appear too nearly equal. Lines C and F are very pleasing. They have divisions which do not seem to be too much alike, so the divisions give diversity. The parts are not so different that they destroy the feeling of unity in the line. A line is pleasing if its two parts are not too much alike and not too different. The ratio of the smaller section of the line to the larger section in C and F is approximately that of 3 to 5. That is to say, if a vertical line is eight inches long, the result is pleasing if the line is divided into two sections which are respectively 3 and 5 inches long. Exact experimentation and measurements of artistic productions show that there is a remarkable preference for this ratio, which is known as the "golden section.'' The exact ratio is that of 1 to 1.618, which is approximately that of 3 to 5. A line is divided most artistically, if the lower section is 1.618 times as great as the upper. Although this fraction seems very formidable, it is the arithmetical expression of a simple proportion which is this : the short section is to the longer section as the longer section is to the sum of both sections. Any division of a line which approximates this golden section is pleasing, but a division which approxi- If you hold No. 1 sideways, the lines will all be changed from vertical to horizontal. The divisions will now assume a new relation. The divisions of lines A, B, and C cease to be more pleasing than those of F, G, and H. E now seems to be divided symmetrically and is more pleasing than D. In fact, for most persons the symmetrical divisions of E seem to be more pleasing than those of even C and F, which are divided according to the ratio of the "golden section." The most pleasing division of a horizontal line is that of perfect symmetry and the next most pleasing is that of the "golden section." In these divisions of straight lines into two equal parts unity is secured ; in the divisions according to the ratio of the golden section diversity is secured, and the unity is not entirely lost. Unity and diversity are essential elements in all esthetic pleasures. In vertical lines we seem to prefer the emphasis on the diversity, while in horizontal lines the exact symmetry, or unity, is most pleasing. The discovery of the most pleasing proportion between the parts of straight lines w^ould be of decidedly more importance if we should find that the same ratio holds for the parts of more complicated figures. Is a rectangle more pleasing than a square? (For the sake of brevity of expression we disregard the fact that a square is a particular form of a rectangle.) Men have been called on to decide this question times without number. By investigating a very large number of sucli decisions we may be able to discover something of value. The architect is called upon to decide this question every time he constructs a building in which the artistic effect plays any part — and it always should. Think of the temples, palaces, cathedrals, cottages, museums, and all other structures in which the artistic element plays a large part. In a great proportion of these the height is not equal to the width. The individual rooms not infrequently bear the same ratios as the height and width of the entire building. Careful measurement of such structures has revealed a striking tendency to approximate what we have learned as the ^'golden section." In fact, it was originally called the "golden section of architecture'/' because it was discovered so uniformly in architecture. the picture frames which you have ever seen, of window panes, mirrors, playing cards, sheets of paper, envelopes, books, periodicals, and all other objects in which the shape is determined to a greater or less extent by artistic demands. In most of these objects we find a very decided tendency to make the height equal the width, or else the height is to the width approximately as 3 is to 5. Look at the square and the rectangle in No. 2. The height of the rectangle is to its base as 3 to 5. Most persons say that the rectangle is the more pleasing ; some have a preference for the square. In the square we have a very decidecj symmetry. Each line is equal to every other line. A straight line drawn through the center of the figure from any angle divides the figure into two equivalent parts. In the rectangle the height is not equal to the length, but a line drawn through the center of the figure divides it into two equivalent parts. The square seems to possess much symmetry but little diversity. The rectangle possesses both unity and diversity. A very careful investigator of the esthetic value of the different space forms gives some interesting results as the fruits of his labors. Thus, a rectangle whose base is three per cent, greater than the height is more pleasing than the perfect square. This is accounted for because we overestimate the height of a square about three per cent. Thus the rectangle whose base is three per cent, greater than its height appears to be a perfect square and so is more pleasing than the perfect square. If the height of a rectangle is approximately eighteen per cent, greater or less than its base, the figure is displeasing because it looks like an imperfect square. If the difference in the two. dimensions of the rectangle becomes as great as forty per cent., the effect is pleasing because the difference is great enough to make it evident that the figure was not meant for a square. If one dimension of the rectangle exceeds the other approximately sixty per cent., we have the ratio of the "golden section," and the result is more pleasing than it is for any other ratio of base to height. If one dimension of a rectangle exceeds the other by more than two hundred and fifty per cent., the result is not satisfactory. The difference between the two dimensions seems to become too great and the unity of the figure is weakened. effect, we are not surprised that we find exceptions to the conclusions reached in the foregoing, but the surprising thing is the lack of more exceptions. Buildings that exceed in height the ratio as given here do not look beautiful, and if the disproportion becomes great because of the excessive height, we call the buildings skyscrapers and regard them as eyesores to the American cities. That which has been said of the square and the rectangle holds equally true for the circle and the ellipse. A circle is a pleasing form which pleases because of its symmetry and regularity. An ellipse that is too much like a circle is much less pleasing than an ellipse in which the smaller diameter is to the greater one as 3 is to 5. The same holds true of a triangle also. The space used by an advertiser is usually a rectangle. In choosing this space, does the advertiser take into consideration the relation of the height and width which will produce the most pleasing effect? He certainly does and the space he chooses meets the conditions of esthetic pleasure as given above, although he may be entirely unconscious of any such intention. Thus in an ordinary niagazine the full page and the ordinary quarter-page (the upper right, upper left, lower right, and lower left) approximate most nearly the "golden section." Next in .the approximation to the standard is the division into upper and lower halves; next comes the horizontal quarter, and last the division into right and left halves. This order of esthetic effect is also the order of frequency of choice of space. The fact that a right or left half-page may be next to reading matter makes this division more popular than it otherwise would be. Turn over the pages of advertisements in any magazine and look at the different spaces to see which class of spaces pleases you most and which least, and you will probably choose the spaces in the order as indicated above. ( No mention has been made of small advertisements, but what has been said of the larger spaces holds true of the smaller also.) Some advertisers have used narrow spaces which extend entirely across the page. The effect has not been pleasing, although such shapes might be striking, because of their oddity. It is to be hoped that no publisher will allow the pages of his magazine to be chopped up into vertical quarters, for the effect would be most inartistic. The artistic subdivisions of spaces follow the laws of symmetry and proportion as given above. Almost every artistic production can be sub-divided into two equivalent parts by drawing a vertical line through the middle of it. Such symmetry as this is called bilateral symmetry. As a typical example of bilateral symmetry as well as pleasing proportion in an advertisement we reproduce herewith the advertisement of the Butler Paper Company (No. 3). The line drawn vertically through this advertisement divides it into two symmetrical parts. Every subdivision of the display and of the text is centered. The horizontal divisions are strictly bilateral symmetry. Dotted lines are drawn to indicate the vertical divisions. In this we see that the subdivisions are not equal, but increase from the bottom upward in a pleasing proportion. A marked display is found in the words "Snow Flake,'' which serve^to divide the text into two unequal divisions which are related to each other in a pleasing proportion. Such an arrangement of the vertical subdivisions is certainly more pleasing large number of figures w^hich are symmetrical and many more which are arranged on the ratio of the "golden section.'^ As a reswlt, pleasing unity and diversity are both secured. The symmetry is pronounced in the twenty-four crystals or stars which are used as a decoration in the border.. There are twelve different kinds of stars, but each star has six main subdivisions and six minor subdivisions. There are enough stars to give diversity, and the stars are sufficiently alike to give unity to the border as a whole. The white rectangle on which the text is found is slightly too long to be in the exact ratio of the golden section, while the darker border is too wide to meet the conditiop, but these rectangles are as near to the ratio of the golden section as could be produced in such a complicated figure as this. It is no accident that the conventional ellipse at the top of the advertisement is in the same ratio as the rectangles, i.e.y that of the golden section. If this advertisement w:ere either lengtliened or shortened, its proportions would vary from that of the "golden section,"' and the results would be recognized by the ordinary observer as less satisfactory. It is not necessary to exaggerate the importance of these laws of symmetry and proportion. They contribute an appreciable amount to the beautification of the advertising page and hence to the production of pleasure in the mind of every possible customer who sees the advertisement. Inasmuch as the pleasure of the customer is of such fundamental importance the advertiser cannot afford to neglect any element which contributes to the total pleasurable effect. There are other laws which are of importance in giving a pleasing effect to a page. Among such laws might be mentioned' ease of comprehension, ease of eye-movement, appropriate point of orientation and utility. Space will not admit of a presentation of these principles, but the purpose of this chapter has been attained if the reader has become impressed with the importance of pleasing the possible customer and with the sig- nificance of such simple laws as that of proportion and symmetry in accomplishing -the desired result. These laws are of universal application in laying out advertisements and in choosing spaces, and an appreciation of their importance by the advertisers of the land would lead to a beautification of the advertising pages of our publications and hence to an increase in their value to the advertiser. SYMPATHY In the last chapter we saw the significance of pleasure and pain in inducing the proper attitude in the minds of the customers. We also saw how a pleasing effect could be produced by the judicious use of the laws of symmetry and proportion in constructing advertisements. In the present chapter we shall continue the general discussion of the benefit of awakening the feelings and emotions and will confine the discussion to a single emotion, namely, that of sympathy. By sympathy we mean in general a particular mental attitude which is induced by the realization of the fact that some one else is going through that particular form of experience. Thus I laugh and feel happy because those about me are rejoicing, and I weep because I see my friends weep. To a certain extent we seem to imagine ourselves as in the condition actually experienced by those about us and hence feel as we assume they must feel. The feelings awakened sympathetically are intense enough to cause weeping, laughing, and all the ordinary forms of expressing the emotions. We are not indifferent as to the objects upon which we bestow our sympathy. I feel no sympathy with the tree that is struck by the woodman's axe nor for the stone that is crushed under the wheels of a traction engine. I may feel sympathy for the mouse whose nest is destroyed or for the horse that is cruelly treated. I sympathize with animals because I believe that they have feelings similar to mine. I feel more sympathy for the higher animals (dogs and horses) than I do for the lower animals, for I believe that their feelings are more like mine. I have a certain amount of sympathy for all humanity, ntxcellencc, is Egypt, easily and directly reached ; by many luxurious Transatlantic linrr^ from New York and Boston to Alexandria. Cook's Nile Steamers from Cairo to the First' and Second Cataracts, (for the Sudan, Khartoum, etc..) leave lour times weekly November to March. ;^ Select Tours and high class Cruises from New^York, January," February and March. ,\Thirty Spring and^Summer /Tours to Europe (of season 1904. For plan>_ofi>liamersprJDl£d.ji)atter,i»nci to Jtcure Jserlhs appl^ jo' but I sympathize most with those of my own set or clique, with those who think the same thoughts that I think and who are in every way most like myself. After those of this inner circle of acquaintances, my sympathy is greatest for those whom I might call my ideals. If I desire to be prosperous, I feel keen sympathy with the man 'who appears to be prosperous. If I am ambitious to be a well-dressed man, I feel sympathetically towards those who are well dressed. If I desire to attain a certain station in life, I feel sympathetically with those who appear to have attained my ambition. In the advertisement of Thomas Cook & Son (No. 1) I do not think of the old lady and gentleman as being of 'my class. They are not my ideals and I therefore have comparatively little sympathy with them. They are enjoying themselves immensely and probably never had a better time in all their lives than they are having as members of this touring party, but as I look at them I am not pleased at all. Their pleasure is not contagious so far as I am concerned. I seem to be immune from all their pleasures. I have no desire to imitate their actions and become a member of Cook's touring party. In»contrast with this first advertisement of Thomas Cook & Son their advertisement of "Magara to the Saguenay" (No. 2) should be considered. The two persons depicted in this second advertisement approximate my ideals. They seem to be enjoying the trip immensely. I believe that they have good taste and if they choose this cruise for their vacation the same trip would be desirable for me too. In every case of sympathy we imitate to a certain degree the persons with whom we sympathize. The action of these young people stimulate me to imitate their action by purchasing a ticket from Cooks and starting on the trip. No. 3 is a reproduced advertisement of a fat-reducing compound. The illustration is supposed to be ludicrous, but to me it is ridiculous. The fat lady in the illustration does not seem to make the best of a bad situation. She dresses in plaids, which, as every corpulent person THE SACUENAY Fourteen Delightful Vacation Days, including such points of interest as Toronto, Alexandria Bay; among the Thousand Islands by daylight and moonlight; down the noble St. Lawrence and its thrilling rapids to Montreal. Then on the magnificent steamship "Cape Eternity"— exclusively reserved — to the Saguenay River! Quebec, Lakes Champlain and George and the Hudson River conclude a tour of beautiful scenic routes unparalleled on this continent. Tours start from Chicago July 17th and 31st, August 14th and 28th. From Niagara Falls one day later. Early reservations advisable. Ask for Particulars of Escorted and Individual Tours to CANADIAN ROCKIES— ALASKA— PACIFIC COASTNATIONAL PARKS— EUROPE— BERMUDA— SOUTH AMERICA— JAPAN— CHINA knows, serve but to increase the apparent size. Both the lady and the gentleman are the kind of people whom we do not admire, who are far from our ideals and who present but few elements of likeness to ourselves. The material advertised might be good for such persons as I beheves it lo be only tenH ponry, antil he mddenly reakze&' that he lias routed iiiany poupdl and DO reincdy appears lo be (orthcoiituig. loyou.wholiavedi tiled into iliis Situation, we can offet truiJis tliat are beyond the sliadow ol questioning. We an brinf; down your weight, not bv elaborate and expensive reauciioa remedies, but by simple treatment (hat brings health and strength int its train. Our hies are filled wiiU hundreds, yes thousands of iesr\r nonob to this effect, and art th^ best guarantees ol our signal success Hereare tv»oof many. Mrsi S. Mann. o( LaMoite. la., writes : Ml X r ears ago t l<M( TO lby VThrte years ago 1 took a lour month* ueatment and wa»\ 'reductd 4 0 lbs. m weight. 1 have DOt gained any in wcighi »uice." We are giving away barrels line of action. No. 4 is a reproduction of an advertisement of a fatreducing tablet, and the illustration is that of a lady who at once begets my sympathy. She is apparently making the best of a bad condition. If she is going to On receipt of k. quest we will send you oat book on ob<:'-ity, which gi%es crii.t.>. atid f.icts of the new cii=.co\,t-ry— a cure by at>sorplio!i to secure such relief. The tragedy and the comedy are forms of literature and of dramatic representations which have always been popular. There is scarcely a tragedy without its comic parts, but frequently there are comedies without any element of the tragic. There are probably more great tragedies than comedies, but it is true that the ordinary men and women read more comedy (including the comic in a so-called tragedy) than tragedy, and that the same holds true for their attendance upon dramatic representations. In a comedy the rollicking fun may be introduced immediately, and the reader or the spectator may be brought into the spirit of the whole at once without danger of any shock to the sensibilities because of the suddenness of the introduction of the emotional element. In tragedy the reader or the spectator is usually inr troduced gradually into the emotional tone of the whole. The hero (if it be the hero who suffers) is first introduced, and then after we feel acquainted with him and have an interest in him, we are called upon to enter into his sorrows and to feel with him. In a political campaign the politician may relate the instances of wrong and oppression for which the opposing party is responsible, or else he may tell of the prosperity and good cheer brought about by his own party. In raising money to found a charitable institution the philanthropist may tell of the squalor and misery of the persons in the district in which the institution is to be located, or else he may tell of the joys which the institution will bring into the lives of the persons concerned. In appealing for funds to carry on the missionary work in Africa the minister may describe the deplorable and' almost hopeless condition of the natives, or else he may tell of the wonderful successes of the missionaries already on the field, and appeal for funds to continue the already successful work. It certainly is questionable which method the politician, the philanthropist, the minister, etc., should follow. As far as my personal observations go, it seems to me that when sympathy for sorrow is successfully awakened, it is more effective in bringing about the desired action than is sympathy for the joys of the persons concerned. It must be remembered, however, that the persons for whom the appeal is being made in all these cases are those for whom the hearers have more than a passing interest, and the creating of this interest may be the product of a long process of education. It may also be true that these most successful pathetic appeals would be avoided in the future by the very persons who had been moved most effectively. The depiction of the darker sides of life may be very effective, but the depiction of the rosier hues is more attractive to most people. It is said that savages laugh more loudly than persons in civilized countries, and in general loud or boisterous expressions of pleasure are not regarded as in good taste. Culture and good breeding have decreed that we shall not express our griefs in the sight or hearing of others. In fact, it is not in good form to express grief at all. We are not allowed to parade our sorrows before the gaze of the public. It seems to be assumed that every one has sorrows enough of his own and therefore should not be called upon to share the sorrows of others. This attitude towards expressions of grief seems to be quite universal, and is taken so much as a matter of course that we feel offended when persons seek to awaken our sympathy by any form of external manifestation. Even in dramatic representations the expressions which accompany sorrow or pain are largely subordinated to apparent attempts to stifle such manifestations. We weep more readily with those who seem to have great cause for weeping, but restrain it, than for those who give way to their feelings. This attitude towards the manifestations of sorrow often causes us to be offended by manifestations of suffering. Thus in No. 5 there is an appeal made to our sympathy in such a rude manner that we feel angry toward the advertiser, if not with the publisher, for allowing us to be insulted by such an audacious attack upon our sensibilities. One function of representations of feelings and emo- Th«se are sAioBi coodiUoas, which, if ootpraapitr conect«d, mil aZect tou laogs asd io a ihort UiM Toa wUi be on tb« roaa to eouamptioal There ia a tare core for a coM aod all the abo««: aitmenta, erea indpieot co&auniptioii,,in Dr. Biiir» Cough STTop. Ida ksoini the world orer aa a famovi docuir's prescripUoa that haa cured thooaaada ft cues. It ia prescribed bf phyaiciasa beeaoa* tbaf ! know it haa aared many people from an earlr fnn,' Poo't delay ; gae bow before too lat« the cewmllA' ' ( eaotbt a bsd oo14. I'^sraboadrnft.asathiabll cUliF, I »u troabled nrj badir vltn li, aod noibvould f1>e me relief I oouiDed ap pbl<(iB anJ wu\|ued uiou righl aloDf Ploailf a tr1«o4 liiTlMi me Of IT a twiUe or Dr. BulVi C«a\|b Brnip. I did mI haro tPDCb (aJth Io Itatflrvi bo«<Ter, »bca I took laa foonh do«. I be^aa Co mtnd. and witbla a jhortUoaa coniulsriog the KTlooaii«» of tnj caK. I vat esUrel cored br i5l! miv^elAia rtmrdT I tbul oeTcr be wlif I)r. Bttll'aCoagh Sn ip w.ll core yoor long trouble. It will do it wilhont faD. KootkeC i^w^AVLTk'^ eqoal.^ it ia caratife-qBaUties, aod for this ruaoa joa cannot afford (• •xportaeal with other remeJiea. sibility. tions is to attract attention. Thus No. 6 is one of the most attractive advertisements in the current issue of our magazines. The smile is very contagious and the whole effect is so clear and so pleasing that I can scarcely turn the page without stopping to look at it. As far as the attention value is concerned, equally good results may be secured by representations of sorrow. Thus in No. 7 sorrow is depicted in such a way that it succeeds in attracting the attention of the most casual reader of advertisements. He knows it is the highest quality, most perfect fountain pen in tb" v/orld, a ceatury ahead of the dropocr Clliii^ kjtids; the only fountain pen that c-.'.n be tilled autoraa'ticf Uy or that succcsbtuily feeds copyiHK lUE. cm FREE HOOKS teive farther «>oriviacjn^ evKJonco. and Ufty ori>tmal i>aK'^rf>ttii>n« forcor rvctiCfj common errori U\ ha-ivdw niinijr. pleasure. which represent the opposite sorts of feelings, and each awakens its appropriate kind of sympathy, and yet it is difficult to tell which advertisement has the greater attentive value. Personally, I enter into the pleasure of the smiling young man more fully than I enter into the sorrow of the grief-stricken one. These examples are sufficient to show that appeals to the sympathy, either for pleasure or for pain, may be used with great profit by the advertiser. We are not cold, logical machines, but we are all human beings, with hearts in our breasts and blood in our veins, and we sorrow. enjoy the depictions of real life with all its joys and sorrows. Whether the dark or the bright side of life offers the most material for the advertiser may be questionable, but there is certainly no question as to the advisability of appeals to the sympathies. carefully as the pages of the literary department. The advertising manager should not only refuse objectionable advertisers, but he should refuse all objectionable advertisements. It is quite possible that an advertisement which might be good for the individual advertiser would be injurious to the many who are occupying space in the same publication. The advertisement reproduced in No. 5 may be good for the firm placing it. It may be attractive to such persons as need the cough syrup, but it may be so disgusting to all other persons that it renders them antagonistic and unsympathetic to all the advertisements seen for minutes after they have looked at this one. It might be a very profitable advertisement for Dr. Bull, but the advertising manager, by accepting it, has reduced the value of all other advertising spaces. The effect which would be produced on adjoining spaces by such advertisements as are shown in Nos. 1, 3, and 7 might also be questionable. If you knew that one magazine carried advertisements which were pathetic in their illustrations and descriptions and that another magazine carried only bright and cheerful advertisements, which one would you pick up and look through? I believe that most persons would choose the magazine advertisements that present only the more cheerful aspects of life. If such is the case, it is the duty of advertising managers to see that the advertising pages of their publications are rendered attractive. HUMAN INSTINCTS We are all accustomed to think of the actions of animals as instinctive, but we are inclined to object to the application to human actions of anything which would obliterate the distinctions between human and animal actions, and we do not usually speak of the actions of man as being instinctive. No one can carefully observe the actions of animals without being impressed witli both the similarities and the differences between human and animal actions. In his native and ordinary environment the animal shows a cleverness of action which is hardly to be distinguished from that of a man. In a new environment and in the presence of unfamiliar objects, on the other hand, the animal displays a stupidity which is most astounding. The animal has but few instincts, and these few are sufficient for his ordinary environment, but in the presence of environments unusual to his species he is at a loss as to his actions. Man possesses many more instincts than the animal and in addition has reason, which can control his instinctive actions and thus obliterate their instinctive appearance, although such actions are fundamentally instinctive. An instinct is usually defined as the faculty of acting in such a way as to produce certain ends, without foresight of the ends, and without previous education in the performance. It is in this sense that the term is used throughout this discussion. undoubtedly prove of interest : ^^NoWy why do the various animals do what seem to us such strange things^ in the presence of such outlandish stimuli? Why does the hen, for example, submit herself to the tedium of incubating such a fearfully uninteresting set of objects as a nestful of eggs, unless she has some sort of a prophetic inkling of the results? We can only interpret the instincts of brutes by what we know of instincts in ourselves. Why do men always lie down, when they can, on soft beds rather than on hard floors? Why do they sit around the stove on a cold day? Why do they prefer saddle of mutton and champagne to hard- tack and ditch-water? Why does the maiden interest the youth so that everything about lier seems more important and significant than anytliing else in the world? Nothing more can be said than that these are human ways, and that every creature likes its own ways, and takes to following them as a' matter of course. Science may come and consider these ways, and find that most of them are useful. But it is not for the sake of their utility that they are followed but because at the moment of following them we feel that that is the only appropriate and natural thing to do. Not one man in a billion, when taking his dinner, ever thinks of utility. He eats because the food tastes good and makes him want more. The connection between the savory sensation and the act it awakens is for him absolute and needs no proof but its own evidence. It takes, in short, what Berkeley calls a mind debauched by learning to carry the process of making the natural seem strange, so far as to ask for the why of any instinctive human act. To the metaphysician alone can occur such questions as: Why do we smile, pleased, and not scowl? Why are we unable to talk to a crowd as we talk to a single friend? Why does a particular maiden turn our wits so upside-down? The common man can only say, ^Of course we smile, of course our heart palpitates at the sight of the crowd, of course we love the maiden, that beautiful soul clad in that perfect form, so palpably and flagrantly made from all eternity to be loved !■ "And so, probably, does each animal feel about the particular things it tends to do in the presence of particular objects. To the lion it is the. lioness which is made to be loved; to the bear, the she-bear. To the broody hen the notion would probably seem monstrous that there should be a creature in the world to whom a nestful of eggs was not the utterly fascinating and precious and never-to-be-too-much-sat-upon object which it is to her. "Thus we may be sure that, however mysterious some animals' instincts may appear to us, our instincts will appear no less mysterious to them. And we may conclude that, to the animal which obeys it, every impulse and every step of every instinct shines with its own sufficient light, and seems at the moment the only eternally right and proper thing to do. It is done for its own sake exclusively. '^ Every instinctive action is concrete and specific, and is the response of an individual directed toward some object. There is a great diversity in the methods of classifying instincts, and any method is justifiable if it is true and if it is helpful in making clear the nature of instincts, or is of service in any way. The classification we propose is justified in that it is true to the facts, secured may be utilized. As was said above, every instinctive action is directed toward some object, but the effect of the action is to bring the object into a relation which will make it helpful toward the preservation or furtherance of the interests of the individual or of the species. Thus when an animal acts according to his ^'hunting instinct" he acts ioward his victim in such a way that he makes the victim serve his interests in providing food for himself and, perhaps, for others of his species. If instincts may be classified according as they tend toward the preservation and furtherance of the interests of the individual, our classification will be based upon the interests of the individual, which are preserved and furthered, rather than upon the manner of the preservation and furtherance. The first interest of the individual which is instinctively preserved and furthered is his material possessions. The individual acts instinctively toward every material thing which he may call ^^my'^ or ^^mine/^ Of all the material things to which I apply the term my or mine, there is nothing to which the term seems so applicable as to my body. This is so intimately mine that the distinction between it and myself or me cannot be definitely drawn. I avoid extremes of temperature, not because I think that thus I can preserve and further the development of the body, but because it is pleasant for me to act that way. I do not refuse to drink stagnant water and seek running water because I think it is best for my bodily health to do so, but because I like the taste of running water and not of stagnant water. I do not refuse grass, green fruit, and decayed vegetables and seek beefsteak, ripe fruit, and fresh vegetables merely or principally because the former are injurious and the latter beneficial to my bodily health. I decide on what I shall eat and drink according as it pleases or displeases me in the eating. The lower animals probably never do anything for the sake of the preservation and furtherance of their bodies, but their instincts guide them so accurately that it seems to us they must do some of these things with that in view. They choose the right food, the right drink, the right companions, etc., etc., because these things seem pleasant to them. Herbert Spencer was of the opinion that mankind could follow instinct in the choice of food, drink, rest, exercise, temperature, etc., and that under normal conditions the choice would be such as would most certainly conduce the highest preservation and development of the body. He believed that our instincts are so strong and so true that, when not perverted, they will act wisely in the presence of the appropriate stimuli, and that the bodily interests will best be furthered by passively following such instincts. He would hold that if that which is good for the body be presented in the proper light, we shall, of necessity, choose it and make the appropriate effort to secure it. If I think anything would taste good, I cannot keep from desiring it. I do not stop to consider whether it would be good for me or not. If it tastes good, that is sufficient. Nature has provided me with an instinctive desire to eat any and every thing that tastes good, and, in general, such an instinct works wholly good. I am a reasoning creature, and it might be supposed that I would select from the different foods those which were best for my health, irrespective of their tastes. I find that my instinct is stronger than my reason in choosing what I shall eat. In the advertisement of Karo (No. 1) is this sentence : '^ . . it makes you eat," and also this: ". . . gives a relish you can't resist.'' I should buy Karo at once if I believed it would be so enticing that it would make me go contrary to my reason and eat it even if my better judgment told me I should not. Irtuoi^si^iiai being emphasized less. The senses (the organs of sight, sound, taste, smell, temperature, and touch) are the guardians of the body, and whatever appears good to these sentinels is instantly desired, and ordinarily such things tend to the preservation and furtherance of the welfare of the body, but we choose them simply because they appear pleasing and not for ulterior ends. My clothes are in a special sense mine. We come to think of them almost as of our very bodies. In our modern forms of civilization this instinct is weakened by the fact that we have so many clothes and change them so often that we hardly have time to become attached to any article of raiment before it is discarded. The close personal attachment which we have for our clothing is beautifully brought out by Professor James : "We so appropriate our clothes and identify ourselves with them that there are few of us who, if asked to choose between having a beautiful body clad in raiment perpetually shabby and having an ugly form always spotlessly attired, would not hesitate a moment." We are all greatly attracted by the protection and ornamentation supplied by clothing. The amount of time which most women and some men spend on the subject of dress might seem absurd to a critic, but such are our human ways, and they seem good to us. Magazines devoted to fashions, shop-windows decorated with beautiful garments, advertisements of clothing — all these have an unending attraction for us. Clothing advertisements are read with avidity, and it has been discovered that all forms of clothing can be advertised with profit by means of the printed page. The most careful observers of the actions of bees assure us that the little industrious bee gathers and stores away the honey simply because she enjoys the process, and not because she foresees the necessity for the honey which will come upon her during the wintry months. To say that the young bee has a prophetic insight of the coming winter is to attribute to it wisdom which is far above human wisdom. them away simply because that is the very action which is in itself more delightful than any other possible action. The squirrel does not store the nuts so that he will have them to eat during the winter, but when the winter comes on and nothing better is at hand of course he will eat them. If he had not stored them he would have starved during the winter, but he did not store them in order that he might not be reduced to starvation. As far as the individual squirrel is concerned, it was purely accidental that his storing the nuts provided against starvation. There are many species of animals which thus collect and store away articles, and in some cases — in an unusual environment — the results are very peculiar. Professor Silliman thus describes the hoardings of a woodrat in California made in an empty stove of an unoccupied house : "I found the outside to be composed entirely of spikes, all laid with symmetry, so as to present the points of the nails outward. In the center of this mass was the nest, composed of finely divided fibers of hemp-packing. Interlaced with the spikes were the following : About two dozen knives, forks, and spoons ; all the butcher's knives, three in number ; a large carving knife, fork and steel ; several large plugs of tobacco; an old purse containing some silver, matches, and tobacco; nearly all the tools from the tool-closets, with several large augers, all of which must have been transported some distance, as they were originally stored in different parts of the house. The outside casing of a silver watch was disposed of in one part of the pile, the glass of the same watch in another, and the works in still another.^ girls who make collections of buttons become exceedingly enthusiastic in their endeavors to make large collections, and, of course, if possible, to secure the most beautiful. If all the girls of the neighborhood are making collections too, the interest is greatly heightened. It is rather remarkable how all the children of a neighborhood may become interested in collecting such things as cancelled postage-stamps. Such a thing would hardly be possible if the children did not have an instinctive desire to make collections. Making collections and hoarding is not confined to children, but is common to all adults. Occasionally some individual becomes absorbed in the process more than others and the results seem to us to be ludicrous, but they are instructive rather than ludicrous. The following is a description of the hoardings of a miser's den which was emptied by the Boston City Board of Health : ^^He gathered old newspapers, wrapping-paper, incapacitated umbrellas, canes, pieces of common wire, cast-off clothing, empty barrels, pieces of iron, old bones, battered tinware, fractured pots, and bushels of such miscellany as is to be found only at the city ^dump.' The empty barrels were filled, shelves were filled, every hole and corner was filled, and in order to make more storage-room, ^the hermit' covered his store-room with a network of ropes, and hung the ropes as full as they could hold of his curious collections. There was nothing one could think of that wasn't in that room. As a wood-sawyer, the old man had never thrown away a saw-blade or a woodbuck. The bucks were rheumatic and couldn't stand up, and the saw-blades were worn down to almost nothing in the middle. Some had been actually worn in two, but the ends were carefully saved and stored away. As a coal-heaver, the old man had never cast off a worn-out basket, and there were dozens of the remains of the old things, patched up with canvas and rope-yarns in the store-room. There were at least two dozen old hats, fur, cloth, silk and straw, etc/' The man who could make such a collection as this is a miser, and he is despised for being such. He had too great a zeal for collecting and hoarding, and he allowed his zeal to obliterate the other possible interests of life. We all seem inclined to keep bits of useless finery and pieces of useless apparatus. The desire is often not yielded to, and the objects are thrown away because their presence becomes a nuisance. We all like to collect money, and the fact that it is useful and that others are making collections too merely tends to increase the instinctive desire to collect. The octogenarian continues to collect money with unabated zeal, although he may be childless and the chief dread of his life is that his despised relatives may secure his money when he is gone. He does not desire that which money will secure, but the obtaining and holding the money is sufficient stimulus to him, even if every acquired dollar makes his difficulties greater by adding new responsibilities. No miser is aware of the fact that he collects for the pleasure he gets out of the collecting and the keeping. He imagines that he collects these things because of their usefulness. He may think that each thing he collects will come handy in some emergency ; but that is not the ground of his collecting, although it may increase the tendency, and also make it seem reasonable to himself. It might be insulting to' a business man to tell him that he was laboring for money merely because of the pleasure he receives in the gathering and keeping of it. Indeed, such a statement would ordinarily be but partially true, for, although the proprietary instinct may play a part, it cer- where are tempted by a possibility of gain. Our proprietary instincts may be made use of by the advertiser in many ways. The irresponsible advertiser has been able to play upon this instinct of the public by offering something for nothing, as is so frequently done in the cheaper forms of advertising media. The remarkable thing about this is that the public should be deluded by such a pretense. The desire to gain seems to overcome the better judgment of the more ignorant public and they become the victims of all sorts of treachery. The reputable advertiser should not disregard this instinct, and might often make it possible to minister to it with great profit, both to himself and to the public, which he might thus interest in what he has to offer. The following advertisement of the American Reserve Bond Co. (No. 2) is an attempt to appeal to this instinct. Why will a man endure hardship for days, endanger his life, and incur great expense, merely for the chance of a shot at a poor inoffensive deer? It certainly is not because of the value of the venison or of the hide. It is not uncommon for a sportsman to give away his game as soon as he has killed it. What he wanted was t-he pleasure of killing the game. Why will a man wade in streams from morning till night, or hold a baited hook for hours in the burning sun? It certainly is not because fish are valuable ; neither does he do it because he believes that it is good for his health. While engaged in the act he is perfectly indifferent to his health, and such a thought would be incongruous to the whole situation. We like to hunt and to fish because we have inherited the hunting instinct from remote ancestors. For the civilized man such an instinct is often worthless, but to our ancestors it was necessary for the preservation of life. The charm which a gun or a fishing tackle has for a civilized man is a most remarkable thing. The annual sale of rifles, revolvers, fishing tackle, fishing boats, and Making Money If you have a $10.00 "nest eggr"and want to see your money grow rapidly, draw large semi-annual dividends, and earn a handsome Surplus, our plan will interest you. > This i3 a great clearing house for savings-profits. We have taught over 200,000 people how to make savings ^rtw and yield la>ge dlVld^nds. The earning power oF Boney is so' much greater than 3% a year, that a banker who has the 'use of savings for that paltry sum, soon grows rich from the profits mat pile up on top of the amount given you iot your share. He turns it over and over, and it grows with every turn; — Because he has inside knowledge of its earning power, and ho •uses that knowledge for'his own private gain. Company in the World. We are guided by the experience of over fourteen years in the handling of savings investments. Our business is under the direct coutrol of various stale laws and subject to periodical official examinations. U you honestly want to save, we stand ready to start you on the right road to financial independence. etc., is beyond anything which could be attributed to their practical need. The hunting instinct shows itself in our fiendish desire for conflict. The more ferocious the animal and the "gamier'^ the fish, the greater is our delight. The conflict may be with a man, and then the fiercer the struggle the better we like it. A street- brawl never fails to attract a crowd. The prize-fighter is always accompanied by the admiring glances of the populace. The accounts of atrocious crimes are read by those who are ashamed to confess it. The advertiser of guns, revolvers, fishing tackle, etc., meets with a ready response from the youth because he appeals directly to his powerful instincts. The following advertisement of Stevens Rifles (No. 3) is a good illustration of an appeal to the hunting instinct : The constructive instinct shows itself in a well-known manner in the bee and the beaver. The sam« instinct is common to man, but the results are not so uniform. We all like to construct things; if they are already constructed, then we want to remodel or improve them. There is hardly a man who at least once has not been .conscious of a strong desire to build a house. If he purchases one already constructed, then he is not content till he has remodeled it in some way. Indeed, if he has built it himself he may make improvements upon it annually. If it is not so that he can make more changes the home loses interest, and is likely to be abandoned. As soon as the possibility of improving a liome has passed going north or south or traveling abroad. In our urban civilization the men are deprived of one of the great pleasures of life. We are shut in as children, and are not allowed to "make a muss'' by our attempts at construction, and in our maturity the in- constructing instinct. stinct is held in check by lack of exercise. If we had some opportunity to make things with our hands we should secure the best possible form of recreation and diversion from the anxieties of business life. The women have all sorts of fancy-work with which they may amuse themselves. Manual-training and domestic science are offering an opportunity to school -children to use their The advertiser can appeal in many ways to this instinct, and is sure to find ready attention and a willingness to pay for the opportunity to exercise this muchneglected instinct. The preceding advertisement of Golden Fleece yarn is such that it makes a woman's fingers tingle with a desire to knit. One of the most striking instincts in the entire animal kingdom is that of maternal love. The mother of one of the higher animals or of the human infant is willing to sacrifice all for her infant. The description which a German by the name of Schneider wrote of this instinct is clearly German, but is an excellent description of the facts : ^'As soon as a wife becomes a mother her whole thought and feeling, her whole being, is altered. Until then she had only thought of her own well-being, of the satisfaction of her vanity; the whole world appeared made only for her; everything that went on about her was only noticed so far as it had personal reference to her ; she asked of every one that he should appear interested in her, pay her the requisite attention, and as far as possible fulfil her wishes. Now, however, the center of the world is no longer herself, but her child. She does not think of her own hunger; she must first be sure that the child is fed. It is nothing to her that she herself is tired and needs rest, so long as she sees that the child's sleep is not disturbed ; the moment it stirs she awakes, though far stronger noises fail to arouse her now. She has, in one word, transformed her entire egotism to the child, and lives only in it. Thus, at least, it is in all unspoiled, naturally bred mothers, and thus it is with all the higher animal mothers. "She does not herself know why she is so happy, and why the look of the child and the care of it are so agreeable, any more than the young man can give an account of why he loves the maiden, and is so happy when she is near. Few mothers, in caring for their children, think of the proper purpose of maternal love for the preservation of the species. Such a thought may arise in the father's mind ; seldom in that of the mother. The latter feels only that it is an everlasting delight to hold the being which she has brought forth protectingly in her arms, to dress it, to wash it, to rock it to sleep, or to still its hunger." (Condensed from James's "Psychology.") Anything that will administer to the needs of the child is a necessity in the eyes of the mother. The matter of expense has to be considered by many mothers, but as men think lightly of expense when satisfying their hunting instincts, so the mothers look upon expense as of secondary importance when supplying the needs of their children. An article which in any way administers to the appearance or comfort of children needs but to be brought to the attention of mothers and it is sure to be desired by them with a desire which is much more than a passing fancy, for it is enforced by the maternal instinct as inherited from countless generations. Advertisers are very successful in appealing to this instinct. The advertisement of Cream of Wheat (No. 5) is but one of many advertisements which thus appeal most forcibly to all mothers. No one chooses solitude for a long period of time. We prefer the best of companionship, but in the absence of the best we accept the best available. Robinson Crusoe took great comfort in the companionship of his man Friday. Solitary confinement is a severer form of punishment than any other employed by civilized nations. We are gregarious and want to be able to see other human beings. Not only do we want to see others, but we want to be seen and noticed by them. instinct. Why should I care for myself as I appear in the minds of other people? It is not necessary for me to explain the origin of such a regard for the opinion of others, but it would hardly have been possible for the race to have developed without such a preference. Indeed, if an in- dividual should become wholly oblivious to the opinion of others, it is doubtful whether he would be able to survive for any considerable period of time. The young man seems compelled to attempt to be at his best before the young lady, but he does not know why. The young boy always tries to "show off" in the presence of young girls. When he comes into the presence of the young girl he seems compelled to undertake something bizarre which is sure to attract her attention. We are all afflicted as the young man and the boy. We consult not only our preference but also the opinion of others in purchasing our clothes and our homes, and in choosing our friends and our professions. We seem compelled to strive for those things which will make us rise in the estimation of others, and in purchasing and choosing we select those things which are approved by those whose esteem we most covet. It is possible for the advertiser of all classes of clothing to take advantage of this characteristic of human nature and to present his garments as if they were being worn by this preferred set. Indeed, at the present time, there are many classes of goods which are being presented as the preferred of the "veritable swells.'' When, on the contrary, an advertiser represents his goods as that preferred by a despised class of individuals, the effect produced is distinctly harmful. The reproduced advertisement of Gage Millinery ( No. 6) makes us believe that by selecting a Gage hat we should be brought, in the eyes of our acquaintances, into the class of persons here represented. The advertisements of Regal Shoes (No. 7) and of White Star Coffee (No. 8) make us avoid them, for we do not want to be considered as in the class with frogs and peasants. The coffee and shoes may be all right, but if, by using them, I am to be thought less of by my acquaintances, I will have none of them. class with this fellQW. Our limbs would be useless unless with them we inherited a desire to exercise them. We do not exercise our limbs in order that we may develop them ; but, nevertheless, the chief value of such exercise may be the development of the limbs. With every" organ we inherit a desire to exercise it in a way which makes for its development. The child^s mind is but a potential affair. It must be exercised in order that it may develop. If the child exercised only when it realized that such exercise was necessary for the development of the body, it is adult again. Along with our bodies we have inherited a psychical nature with all its diversified possibilities. The psychical nature is, however, but little more than a possibility which needs vigorous exercise for its realization. We have a moral nature, which, in the beginning, is in the crudest possible form, but we have an inherited liking for the consideration of moral questions. This consideration may be of the actions of the hero in a story, of the nation's leaders, of a seller of merchandise, or of No. 8. — A poor advertisement. What would my acquaintances think of me if I preferred the same brand of coffee as that which delights the frogs? a personal friend. Such consideration of actions of others is most beneficial in the development of the moral sense, and when moral questions are presented in a true light, they are intensely interesting to all classes of persons. . Socrates believed that all persons would prefer the right whenever they saw it, and that all evil actions were from ignorance. Such a view is evidently an exaggeration, but we certainly do prefer what we regard to be the right, and reject what we regard to be the wrong. This is especially true in regard to the actions of others. We are disgusted and repulsed by what we regard as wrong in others. If an advertiser's argument, illustration, and condition of purchase are such that they offend the moral sense of the reader, the advertisement is of little or no value. It may be difficult to appeal especially to the moral judgment of the possible customer in presenting most goods, but any offense to such a moral judgment must be scrupulously avoided. In the advertisements of books, periodicals, and schools, the moral judgment can safely be counted on. Whether the religious nature be developed from the moral or not, it certainly is true that the two are very closely connected, and that they must both be regarded with care by the advertiser, whether they be appealed to directly by the advertisement or not. The avidity with which we seek things which appeal to our religious nature is illustrated by a circumstance related in the September, 1904, issue of the Atlantic Monthly. A book was offered to the public with the title, "The Wonders of Nature," but the sales were disappointing. The title was changed to "The Wonders of Nature, the Architecture of God," and the sales were immediately increased and a second edition was necessary. We have even as children an embryonic, esthetic nature. Things beautiful have a fascinating effect upon the unperverted individual. We need but to have objects of beauty brought to our attention and we desire them without being taught their desirability. Furthermore, the beautiful affects us without our knowledge of the fact. We stop and look at a beautiful advertisement, but may not be aware that it is the beauty that attracts us at all. The best works of art are such that the attention is drawn wholly to what is represented, and not to the manner of the representation. The advertisement which is most artistic may be one which never affects the public as being artistic at all, but it is the one which will be most effective in impressing the possible customer. One reason why so much attention is given to the advertising pages of our magazines is that they are so artistic. We have an intellectual nature, but in the case of the child the intellect is little more than a spark which, however, is sufficient to indicate the presence of that which may be 'developed into a great light. The child is prompted by curiosity to examine everything that comes into its environment. It tears its toys to pieces that it may learn of their construction. At a later age the youth takes delight in the acquisition of knowledge independent of the utility of such knowledge. The curiosity of the human race is the salvation of its intellect, and at the same time makes a convenient point of attack for the advertiser. The public wants to know what is offered for sale. It wants to hear the story which the advertiser has to tell. There are other stories to hear, and the advertiser must not have the most uninteresting one if he expects to take advantage of this instinctive desire of the individual to become acquainted with all novel objects and to learn all he can concerning new aspects of familiar ones. Occasionally this characteristic of curiosity may be made use of by the advertiser in what might seem to be an absurd manner, and yet the results be good. As an illustration, observe the reproduced advertisement of "What did the woggle bug say?'' (No. 9). This advertisement seems to be extremely absurd, and yet, in some way, it has been able to arouse the curiosity of many readers, and it is quite possible that it has been a successful advertisement. We have seen above that we have instinctive responses to act for the preservation and furtherance of (1) our bodies, clothes, homes, personal property, and family (also the hunting and constructing instincts which are more complex than others of this class) ; (2) ourselves as we exist in the minds of others ; (3) our mental faculties. We have seen that to secure action along these lines it is not necessarv to show the value of such action designed to arouse curiosity. or the necessity of it, but merely to present the proper stimulus, and the action is forthcoming immediately. The advertiser should study human nature to discover these hidden springs of action. He desires to produce the maximum of action along a certain line with the minimum of effort and expense to himself. If he can find a method whereby his efforts are seconded by some of the most powerful of the human instincts, his task will be simplified to the extreme. The discovery of such a method is a task for the leaders of the profession of advertising. SUGGESTION The mental process known as '^Suggestion" is in bad repute because, in the popular mind, it has too often been associated on the one hand with hypnotism and on the other with indelicacy and vulgarity. Hypnotism in the hands of the scientist or of the fakir is well known to be a form of suggestion. A story which does not specifically depart from that which conforms to the standards of propriety but which is so constructed that it leads the hearers to conceptions that are "off color'' is said to be suggestive. In this way it has come to pass that the whole subject of suggestion has been passed by with less consideration than is due it. There is no uniformity in the meanings that are attached to the term suggestion even among the most careful writers. If I were sitting in my office and considering the advisability of beginning a certain enterprise, I might say that one idea "suggested" a second and this second a third, etc. A scientific definition would not allow this use of the term but would substitute the expression "called up" for "suggested." Thus I should say that one idea "called up" the second, etc. Suggestion must he brought about by a second person or an object. In my musings and deliberations I should not say that one idea suggested another, but if the same idea were called forth at the instigation of a second person or upon the presentation of an object, I should then call it suggestion — if it met the second essential condition of suggestion. This second condition is that the resulting conception^ conclusion^ or action must follow with less than the normal amount of deliberation. Suggestion is thus a relative term, and in many instances it might be difficult to say whether or not a particular act was suggestion. If the act followed a normal amount of consideration after a normal time for deliberation it would not be suggestion, while if the same act followed too abruptly or with too little consideration it might be a true case of suggestion. Every normal individual is subject to the influence of suggestion. Every idea of which we think is all too liable to be held for truth, and every thought of an action which enters our minds is likely to result in such action. I do not think first of walking and then make up my mind to walk. The very thought of walking will inevitably lead to the act unless I stop the process by the thought of standing still. If I think of an object to the east of me my whole body sways slightly in that direction. Such action is so slight that we ordinarily do not discover it without the aid of accurate recording instruments. Almost all so-called mind-reading exhibitions are nothing but demonstrations of the fact that every thought which we think expresses itself in some outward action. Thought is dynamic in its very nature and every idea of an action tends to produce that action. The most perfect working of suggestion is to be seen under hypnosis and in crowds. In hypnosis the subject holds every idea presented as true, and every idea sug:: gested is acted out with no hesitation whatever. Here the mind is so narrowed by the artificial sleep that no contradictory or inhibiting idea arises, and hence no idea can seem absurd and no action seems out of place. There is no possible criticism or deliberation and so we have the extreme case of susceptibility to suggestion. The effect of a crowd upon an individual approaches that of the hypnotizer. The individual is affected by every member of the crowd and the influence becomes so overpowering that it can hardly be resisted. If the crowd is a ^'lynching party" the whole atmosphere is one of revenge, and everywhere is suggested the idea of ^^lynch the culprit." This idea is presented on all sides. It can be read from the faces and actions of the individuals and is heard in their cries. No other idea has a chance to arise in consciousness and hence this one idea, being dynamic, leads to its natural consequences. It was once supposed that suggestion was something abnormal and that reason was the common attribute of men. To-day we are finding that suggestion is of universal application to all persons, while reason is a process which is exceptional, even among the wisest. We reason rarely, but act under suggestion constantly. There was a great agitation some years ago among advertisers for "reason why" copy. This agitation has had some value, but it is easily overemphasized. Occasionally customers are persuaded and convinced, but more frequently they make their purchases because the act is suggested at the psychological moment. Suggestion and persuasion are not antagonistic ; both should be kept in mind. However, in advertising, suggestion should not be subordinated to persuasion l)ut should be supplemented by it. The actual effect of modern advertising is not so much to convince as to suggest. The individual swallowed up by a crowd is not aware of the fact that he is not exercising a normal amount of deliberation. His actions appear to him to be the result of reason, although the idea, as presented, is not criticised at all and no contradictory or inhibiting idea has any possibility of arising in his mind. In the same way we think that we are performing a deliberate act when we purchase an advertised commodity, while in fact we may never have deliberated upon the subject at all. The idea is suggested by the advertisement, and the impulsiveness of human nature enforces the suggested idea, hence the desired result follows in a way unknown to the purchaser. Some time ago a tailor in Chicago was conducting a vigorous advertising campaign. I did not suppose that his advertising was having any influence upon me. Some months after the advertising had begun I went into the tailor's shop and ordered a suit. While in the shop I happened to fall into conversation with the proprietor and he asked me if a friend had recommended him to me. I replied that such was the case. Thereupon I tried to recall who the friend was and finally came to the conclusion that this shop had never been recommended to me at all. I had seen his advertisements for months and from them had formed an idea of the shop. Later, I forgot where I had received my information and assumed that I had received it from a friend who patronized the shop. I discovered that all I knew of the shop I had learned from advertisements and I doubt very much whether I ever read any of the advertisements further than the display type. Doubtless many other customers would have given the same reply even though, as in my case, no friend had spoken to them concerning the shop. Ideas which have the greatest suggestive power are those presented to us by the actions of other persons. The second most effective class is probably the ideas suggested by the words of our companions. Advertisements that are seen frequently are difficult to distinguish in their force from ideas which are secured from the words of our friends. Advertising thus becomes a great social illusion. We attribute to our social environment that which in reality has been secured from the advertisements which we have seen so often that we forget the source of the information. Street railway advertising is especially effective at this point because the suggestion is presented so frequently that we soon forget the source of the suggestions and end by attributing it to the advice of friends. In advertising some commodities argumentation is of more importance than suggestion, and for such things booklets and other similar forms of advertising are the most effective. Such commodities are, however, the exception and not the rule. In the most successful advertising argumentation and forms of reasoning are not disregarded, but the emphasis is put upon suggestion. Inasmuch as more of our actions are induced by suggestion than by argumentation, advertising conforms, in this particular, to the psychological situation. It puts the emphasis where the most can be accomplished and subordinates those mental processes which hold a second place in determining our actions. As stated above, those suggestions are the most powerful which we receive from the actions and words of other persons. The successful advertiser seems to have worked upon this hypothesis in constructing many advertisements. He has also taken advantage of the fact that we soon forget the person who originally suggested the idea and become subject to illusions upon the matter. Thus, in the reproduced advertisements of Jap-a-lac (No. 1), as I see this young lady using Jap-a-lac the suggestion to do the same thing is overpowering. Many a woman who has looked at these pictures has been immediately overcome by a desire to do the same thing- and has put her desire into execution. If I had seen these and similar cards for a few months, even though I had never seen any one actually using the paint, I should assume that "every one is using Jap-a-lac." The suggestion would thereupon be in an extreme form and be liable to cause me to imitate what I assumed every one else was doing. As a matter of fact I was affected in just this manner. When occasion arose to purchase some paint for household use I called for Jap-a-lac under the assumption that I had seen it used frequently. The can looked familiar, and it seemed to me that I was running no risks, for Jap-a-lac had been a household commodity for years. Soon after the purchase I began to write this chapter and I am unable to recall any instance of having seen Jap-a-lac in use. I had seen pictures of the Jap-alac paint can and had seen pictures of persons using the paint, but I know of no other source of information concerning this paint, although at the time of the purchase of the paint my knowledge of it seemed to me perfectly adequate. Apparently I had never heard an argument in favor of the paint but had acted upon mere suggestion. Women are, in general, more susceptible to suggestion than men, and I feel sure that many women are convinced of the adequacy of this paint by these same advertisements, reproduced above, even though nothing more than the display and the picture is noticed. It seems that no form of action can be suggested by an advertisement that does not successfully challenge the reader to do what is proposed. The suggested idea haunts one, and even though the action may be absurd, it is difficult to resist. The four following reproduced advertisements depend upon suggestion and are said to be extremely successful. Many persons doubtless feel the suggestion to be irresistible to rub the end of the first finger when looking at this advertisement of Lucas Tinted Gloss Paint. What could be more absurd thanWesterf eld's advertisement? The fact that this advertisement was highly successful is sufficient justification for its use. Kerr's studio was flooded with answers to the suggestion of "Guess who?" The Yucatan sign language does not affect me, but I cannot look at the beautiful girl saying "Yu"-"ca"-"tan" without a pro- nounced tendency to imitate her. The suggestions in these four advertisements lead the readers to desire to act in the ways suggested, and that of necessity leads to an interest in the goods advertised. As stated above, the words of our friends have strong suggestive power. We are not cold, logical machines, who take data in and then, by a logical process, come to a reasonable conclusion. On the contrary, we are so highly susceptible to suggestion that the words of our companions are ordinarily held for true and the actions proposed by them are hastily carried out. The suggestiveness of the words of companions is a force available to the advertiser. He places before the public a state- mend Arrow collars. ment and then, to give greater suggestive power, he shows the likeness of a person whose face indicates the possession of a judgment we should be willing to take. The advertiser does not state that the words are those of the person depicted, but this relationship seems to be suggested and it adds greatly to the value of the advertisement. Thus in the reproduced advertisement of Postum Food Coffee the picture of the venerable doctor becomes associated in our minds with the statement, "If coffee don't agree, use Postum Food Coffee." Later these words seem to have issued from a responsible person and come to have undue weight with us all. Likewise in the reproduced advertisement of Arrow collars the genial washerwoman seems to assure us that " Arrow Collars don't shrink in the wash." In the case of the Calox advertisement I am convinced when this power of this advertisement. beautiful girl points lier finger at me and seems to say, " Yes, you ought to use Calox.'' As I happen to need more tooth powder just now, I don't wait for further evidence but accept uncritically the words which she is HAND SAPOLIO by ^a^ method of its own cleans the pores, aids the natural changes of the skin, and imparts new vigor and life. C, Don't argue, Don't infer. Try it! CIt's a lightning change from office to parlor with Hand Sapolio. gestion is subordinated to argumentation. represented as using. When we stop to think of it, it is absurd to place credence in these words of the advertiser simply because of the presence of an appropriate picture, but the absurdity of the situation does not detract from the practical value of such forms of suggestion. y^OU have been entertained by a gracious hostess — a little dinner party perhaps to which you have been invited by a business friend. A gift of flowers next day will express the appreciation you feel. The girl you danced with, who was good to you in finding other partners — a gift of flowers next day is the tribute you owe. For every occasion when some thoughtful attention on your part is hard to express in words — " Say it with Flowers," the gift acceptable. Your local flonst, withtn a few hours, can deliver fresh f overs in any city or town in the United States and Canada through the Florists' Telegraph Delivery Service. The florist displaying the sign " Say it with Flowers " is a member of the Society of American Florists, which enables liim to serve you better when you buy flowers. The reproduced advertisement of the Society of American Florists (No. 9) is one in which suggestion is used successfully. The picture tends to beget imitation. " Say it with Flowers " is one of the cleverest phrases in current advertising. The reminder of occasions demanding a gift of flowers becomes an irresistible suggestion. Many forms of suggestion, in addition to those presented above, are available to^the advertiser. There* is also no necessary divorce between suggestion and the presentation of arguments. Indeed, the application of the two in the same advertisement often increases the value of each. Thus in the reproduced advertisement of Hand Sapolio (No. 8) the direct suggestion, " Hand Sapolio should be on every washstand," is strengthened by the " reasons why,'' and the reasons why are strengthened by this suggestion. These reproduced advertisements are presented as mere illustrations of a few of the many ways in which suggestion may be used by the advertiser. We have but to consider the millions of persons who at least glance at advertisements, to be impressed by the possibilities opened to the man who can present his advertisement in a form that suggests powerfully the purchase or use of his commodity. THE WILL: AN ANALYSIS During all the waking hours of the day there is something about which we are thinking; we have a particular tone of feeling^ and there is something for which we are striving. We know something, we feel somehow, and we strive for something not yet attained. Knowing, feeling, and willing are the three universal aspects of all our mental activities. As I sit in my chair I am conscious of the furniture in the room, the line of thought which I am carrying out, and the necessity of completing my task in a given time ; I feel pleased with the comfort of the situation and the excitement of composition ; I am putting forth activity of w ill in striving to accomplish a certain end and to express myself on a typewriter. Sometimes our condition is one of intense feeling, at another it is primarily intellectual grasp of a situation, and at other times it is especially a putting forth the will in attempting to accomplish some end or to reach some conclusion. Although each of the three aspects of consciousness may for a time predominate, yet it is probable that all three activities are present at all moments of our conscious existence. Under the will may be included all the active processes of the mind. This activity may express itself either in bodily movements or in some such mental processes as attention or volition. Under the bodily activities are such as impulsive, instinctive, and voluntary actions. At this time it will be well to confine our attention to but a part of these activities of the will, viz., voluntary actions. A definition of volition would not make the subject any clearer to us, but here the term is used in an untechnical sense and includes such -things as decision, choice, voluntary actions, and all actions performed after consideration. It includes a mental procesl and the resultant, bodily activity. It is probably true that a majority of our actions are performed without such consideration, but it is because of the existence of voluntary action that the advertiser finds it necessary to proceed logically and to appeal to the reason of his customer. A careful consideration of the elemental processes involved in such actions is of great advantage in enabling the advertiser to bring about the decision desired. Voluntary actions may be analyzed into (a) an idea of two or more attainable ends, ( & ) an idea of the means to attain these ends, ( c ) a feeling of the value of worthiness of the different ends, {d) sl comparison of the values of the different ends and of the difficulties of the means, and, finally, (e) a choosing of one of the ends and striving to attain it. These ^ye processes in a voluntary action may be illustrated as follows : (a) I think of a suit that I might buy, the trip that I might take, and of the debt that I might pay; (6) I think of the trouble of going to the tailor shop, the inconvenience of waiting for the train, and the distance to be covered to reach the creditor; (c) I feel in imagination the pleasure of possessing the new suit, the delights connected with the trip, and the satisfaction of having the debt paid; (d) I compare the difficulties of possessing each and the pleasures derivable from the possession; {e) I decide to take the trip and start for the ticket office. question which naturally arises in the mind of the advertiser is this: What can be done to cause the largest number of persons to decide in favor of my particular goods? Suppose that the article of merchandise under consideration be a piano : now how may the advertiser proceed in accordance with the analysis presented above? (a) The piano must be brought before the public in such a manner that the idea of it will be clear and distinct in the minds of the potential purchasers, (h) The public must be informed exactly what is necessary to secure the piano, (c) The piano must be presented in such a manner that its value seems great. (d) The value of the piano must be presented in such a way that, when compared with other forms of action, the purchase of the piano seems the most desirable. The means of securing the piano must be made to appear easy, (e) Pressure must be brought to bear to cause immediate decision and action on the part of the public in favor of the particular piano. Elaborations of each of these five points will suggest themselves to any thoughtful advertiser. That the idea of the piano may be clear and distinct (a) illustrations may be used to advantage; the language used should conform to the mode of thinking of the public appealed to; the type used should be easily read; the description should be as brief as is possible for completeness of presentation of essential features. In order that the public may know exactly how to secure the piano (h) the exact cost must be presented; the method of sending the money, the delivery and setting up in the home might well be included in the statement of the advertisement. The feeling of value may be awakened for the piano (c) by advertising it in the highest class of media, by having a beautiful advertisement, by empha- sizing the elegance of the instrument and the perfection of the tone, by indicating what a joy it is in a home, and by any other means which would tend to associate the piano with feelings of pleasure. It is assumed that other pianos will be considered by the possible purchas- ' ers and that when others are considered they will suffer by comparison (d). That this may be true it will be necessary to describe the strong points of the piano in such a way that the value of the piano seems great, and the cost of it and the means of securing it seem less burdensome than those connected with competing pianos. That the choice may be made at once and effort put forth to secure the piano (e) reasons for avoiding delay might be presented or the suggestion to action might be so strong that the tendency to procrastinate would be overcome. Although every customer who is induced to select any particular line of goods after consideration must inevitably perform the five processes as described, and although an ideal advertisement would be so constructed that it would assist the customer in completing each of the five processes, yet it is not to be assumed that each advertisement should be constructed so that it would be well adapted to promote each of the five processes. On the other hand, it is quite true that many advertisements are ineffective because the writer has not paid attention to these fundamental psychological processes of voluntary actions". In the reproduced advertisement of Triscuit (No. 1) the first step of the act of volition (a) is emphasized. 'This advertisement gives the reader a clear and vivid idea of the product advertised. No one can read the advertisement without knowing what the product is made of, how it looks, how it is manufactured, and what it is good for. The reproduced advertisement of Holbrookes Sauce (No. 2) occupied the cover page in a British magazine which is about twelve by sixteen inches in size. In all this space nothing is shown or said which gives us an idea of the real nature of the product advertised. After examining this advertisement carefully I am still at a ing them. loss to know the real nature of the product. Such a use of space can be justified only on the assumption that the public is already familiar with the sauce, or that this is to be but a single link in the chain and that later or preceding advertisements supply what is deficient in this single advertisement. for securing the goods advertised. The advertiser is so familiar with his goods and the means of securing them that he forgets that others know nothing of them. It is needless to reproduce any particular advertisement to illustrate this point. are widely distributed are advertised on the assumption that everybody knows that they are to be secured at all dealers. It is not wise to assume any such knowledge on the part of the general public. In the advertisement of Triscuit no mention is made of the fact that it can be secured from all first-class grocers, and many persons assume that Triscuit can be had only at the address given at the foot of the advertisement. In the adver- tisement of Holbrook's Sauce (No. 2) no address is given and nothing is said of the place where it can be secured. The writers of the advertisements have assumed that the public knows more of these goods than the facts warrant. The reproduced advertisement of Jap-a-lac (No. 3) securing the goods. leaves no doubt in the mind of the public as to the means of securing the paint. "For sale by painty hardware and drug dealers. All sizes from 15c to $2.50.'^ This statement is sufficient for most persons, but not for all, and we find this statement in addition : "If your dealer does not keep Jap-a-lac, send us his name and 10c and we will send free sample/' This advertisement gives us a clear idea of the means necessary for securing the advertised goods and hence facilitates the second process in a voluntary action and increases the chances of securing the desired action. No advertisement should ever appear which leaves any doubt in the minds of possible customers as to where and how the goods advertised can be secured. The absence of such information is very common and impresses the writer as one of the weakest points in modern advertising. The third process in our analysis of voluntary action is the feeling of worthiness or value (c) . It is not sufficient to have a clear idea of an end and a definite idea of the means of securing it unless there is an accompanying feeling of value. The advertiser is thus compelled to make his commodity appear valuable. This fact is accomplished by most advertisers but not by all. The reproduced advertisement of Nabisco (No. 4) presents the product as particularly worthy. The advertisement is intrinsicall}^ beautiful. The cut and the copy harmonize completely. The young girl depicted could be described as "a fairy," and "airy lightness and exquisite composition'' is characteristic of the entire cut. The copy appeals to our instinctive desires for savory viands in a most enticing manner, and also appeals to the feminine social instinct by the following words : ". . . to afford the hostess opportunity for many original conceptions in the serving of desserts." The greatest feeling of worth attaches itself to those things which are the objects of our most fundamental instinctive desires. A feeling of worth inevitably attaches itself to every savory viand, to every beautiful object, and to every agency which furthers our social instincts. parison of competing ends as to value and means of acquisition. When an advertiser realizes that the public to which he is appealing will compare his goods with those of his competitor, he is tempted to resort to the questionable method of showing the weak points of his competitor's merchandise or method of sales. There may be instances in which this method is justifiable and even necessary, but ordinarily it is self-destructive. The* act of comparison {d) is a process in volition that the advertiser should not seek to encourage. It is a hindrance to the advertiser and his function is to minimize it. If I, as an advertiser, am offering goods in competition with other goods, I know that my goods will be compared with the others, and it is my place to give the reader such a clear and vivid idea of my goods (a) and to make the means of securing them so plain (&) that my goods will not suffer by comparison. My purpose is best served by holding my goods up to the attention of the potential purchaser and not by emphasizing the weaknesses of those of my competitor. I must emphasize the strong points of my merchandise and especially those points in which my goods are superior to competing goods, and in this way I get attention to those points at which my goods will gain by comparison. The last point in the analysis of the process of volition (e) is that of choosing one of the ends and striving to attain it. All the other stages of the process are but subsidiary to this. What can the advertiser do to secure or to facilitate this part of the process? It is a wellknown psychological fact that at the moment of final decision all competing ideas are usually banished from the mind and attention is centered on the idea (the merchandise) which is chosen. At the moment of final choice we do not hold competing lines of action before us and then choose the one that seems the best. The process is one of elimination preceding the choice. We compare different lines of action and eliminate one after another till but one is left. This one has seemed better than the others and it is held to and acted upon. The acting upon it is often a part of the choice. The one line of action is before us and the very act of attending to the one idea results in the appropriate action. There may have been no conscious choice preceding the action, but now that the action has commenced the competing ideas are kept from the mind and the action gets put into fulfillment. There are therefore two distinct things which the advertiser can do to facilitate this final step. In the first place he fills the mind of his potential customers with thoughts of his own particular goods, and in the second place he suggests immediate action. The mind of the customer is filled by the processes described in (a), (h), and (c). Immediate action is suggested by ( & ) and by some such device as the return coupon, the direct command, etc. ( For a fuller discussion of this point see chapters V and VI of "The Theory of Advertising.") The advertiser who fails to state the method of securing his goods fail^ to give one of the strongest possible suggestions to action. If it were even possible that every reader of the advertisement of Jap-a-lac already knew the price of it and where it could be secured, still the advertisement is strengthened by giving these details in that it gives the suggestion to action as nothing else could do. The suggestion to action might be strengthened by additional details but not by substituting for them. THE WILL: VARIETY IN ACTION In the preceding chapter an analysis of a typical action was given without reference to the fact that actions are not ordinarily typical. No two acts are exactly alike. Individuals are different and employ divers methods in performing their acts. In the case of a single individual the most diverse methods are employed at different times and under diffe^^ent circumstances. The personal differences in methoa^ of deciding questions and resultant actions have been so beautifully expressed by Prof. William James that it seems useless to attempt any improvement upon his presentation of the five methods of deciding or choosing : ^'The first method may be called the reasonable type. It is that of those cases in which the arguments for and against a given course seem gradually and almost insensibly to settle themselves in the mind and to end by leaving a clear balance in favor of one alternative, which alternative we then adopt without effort or constraint. . . . The conclusive reason for the decision in these cases usually is the discovery that we can refer the case to a class upon which we are accustomed to act unhesitatingly in a certain stereotyped way. . . . The moment we hit upon a conception which lets us apply some principle of action which is a fixed and stable part of our Ego, our state of doubt is at an end. Persons of authority, who have to make many decisions in the day, carry with them a set of heads of classification. each bearing its volitional consequence, and under these they seek as far as possible to range each new emergency as it occurs. It is where the emergency belongs to a species without precedent, to which consequently no cut-and-dried maxim will apply, that we feel most at a loss, and are distressed at the indeterminateness of our task. As soon, however, as we see our way to a familiar classification, w^e are at ease again. . . . The concrete dilemmas do not come to us with labels gummed on their backs. We may name them by many names. The wise man is he who succeeds in finding the name which suits the needs of the particular occasion best. "A ^reasonable' character is one who has a store of stable and worthy ends, and who does not decide about an action till he has calmly ascertained whether it be ministerial or detrimental to any one of these. In the next two types of decision, the final fiat occurs before the evidence is all ^in.' It often happens that no paramount and authoritative reason for either course will come. Either seems good, and there is no umpire to decide which should' yield its place to the other. We grow tired of long hesitation and inconclusiveness, and the hour may come when we feel that even a bad decision is better than no decision at all. Under these conditions it will often happen that some accidental circumstance, supervening at a particular moment upon our mental weariness, will upset the balance in the direction of one of the alternatives, to which we then feel ourselves committed, although an opposite accident at the same time might have produced the opposite result. "In the second type our feeling is to a great extent that of letting ourselves drift with a certain indifferent acquiescence in a direction accidentally determined from without, with the conviction that, after all, we might as are in any event sure to turn out sufficiently right. ^^In the third type the determination seems equally accidental, but it comes from within, and not from without. It often happens, when the absence of imperative principles is perplexing and suspense distracting, that we find ourselves acting, as it were, automatically, and as if by a spontaneous discharge of our nerves, in the direction of one of the horns of the dilemma. But so exciting is this sense of motion after our intolerable pent-up state that we eagerly throw ourselves into it. ^Forward now!' we inwardly cry, 'though the heavens fall.' "There is a fourth form of decision, which often ends deliberation as suddenly as the third form does. It comes when, in consequence of some outer experience or some inexplicable inward change, we suddenly pass from the easy and careless to the sober and strenuous moody or possibly the other way. The whole scale of values of our motives and impulses then undergoes a change like that which a change of the observer's level produces on a view. The most sobering possible agents are objects of grief and fear. When one of these affects us, all ^light fantastic' notions lose their motive power, all solemn ones find theirs multiplied many fold. The consequence is an instant abandonment of the more trivial projects with which we had been dallying, and an instant practical acceptance of the more grim and earnest alternative which till then could not extort our mind's consent. All those ^changes of heart,' ^awakenings of conscience,' etc., which make new men of so many of us may be classed under this head. The character abruptly rises to another 'level,' and deliberation ^omes to an immediate end ^^In the fifth and final type of decision, the feeling that the evidence is all in, and that reason has balanced the books, may be either present or absent. But in either case we feel, in deciding, as if we ourselves by our own wilful act inclined the beam: in the former case by adding our living effort to the weight of the logical reason which, taken alone, seems powerless to make the act discharge; in the latter by a kind of creative contribution of something instead of a reason which does a reason's work. The slow dead heave of the will that is felt in these instances makes a class of them altogether different subjectively from all the four preceding classes. If examined closely, its chief difference from the former cases appears to be that in these cases the mind at the moment of deciding on the triumphant alternative dropped the other one wholly or nearly out of sight, whereas here both alternatives are steadily held in view, and in the very act of murdering the vanquished possibility the chooser realizes how much in that instant he is making himself lose." These five methods of deciding are methods which we all use to a greater or less extent. Every one has probably experienced each of them at some time, yet some people habitually decide by one method and others by another. The man who habitually waits in deciding till all the reasons for and against a line of action are before him belongs to the first class. The man who "flips a copper" whenever anything is to be decided belongs to the second class. The man who is impulsive and who acts "intuitively," but who does not know w^hy he acts so, belongs to the third class. These three classes are known to us all. There is probably no one who decides questions habitually after the manner described in Professor James' fourth and fifth classes. Of these five methods of decision some are of little significance to the advertiser although of primal significance to the psychologist. The fifth, then, is of no significance to the advertiser except that it is the form which he seeks to obviate. He tries to get the public to dismiss all thought of competing articles. To accomplish this he makes no mention of competitors, but confines his argument to his own commodity. In the fourth of Professor James' divisions the person, in deciding, passes from the easy and careless to the sober and strenuous mood. This accounts for the fact that certain advertisements may be seen and read frequently with no effect for years, then suddenly this same advertisement becomes all-powerful. This is true in advertising such things as life insurance, homes, good books, and other forms of merchandise which appeal to the higher nature of man. The reproduced advertisement of Modern Eloquence (No. 1) might not appeal powerfully to readers while they are in a careless and easy mood, but when the mood is changed the same advertisement might be most effective. In the third type, which is mainly a form of suggestion, the decision is dependent upon a sudden spontaneity of an emotional nature and leaves but little for the advertiser to do. Women decide after this fashion more frequently than men. Here the advertiser can do most by appealing to the artistic and sentimental natures of the possible customers. The appearance of the advertisement, of the store, or of the salesman is not recognized by the woman as the deciding element, although in reality it is. If a lady were debating the question as to which goods she should order, an appeal to the artistic and sentimental might awaken her emotional nature sufficiently to cause her to decide, and the reader. ing type, but is one which approaches action upon suggestion and hence anything which the advertiser can do to suggest action aids in securing the results which come under this class. This class of persons will not, at the critical moment, search through the back files of maga- zines to find an advertisement, neither will tliey exert themselves to find a store not centrally located if a more convenient one is passed at the critical moment of decision. If I belong to this second of Professor James' classes, and if I am trying to decide which watch I shall successful. buy, I will purchase the one which presents itself to me at the psychological moment, whether the presentation be by advertisement, salesman, or store. An extensive advertiser recently said that any kind of advertising would succeed if the advertisements were large and if they appeared frequently enough. This statement is certainly not true but it does find some justification based on the decisions of such persons as are assigned to eJames^ second type. The reproduced advertisement of Pears' Soap (No. 2) is so exceedingly poor that it would be defended by but few. If a man were debating which sort of soap he shoulc^ purchase and if at the critical moment he should see this advertisement it might possibly induce him to order Pears'. The reproduced advertisement of Cook's Flaked Rice (No. 3) is similar to that of Pears' Soap. If these two advertisements (and others equally poor) were given extensive publicity they would undoubtedl}^ increase the sale of the goods advertised simply because so many persons decide according to Professor James' second class and because so many unimportant questions are decided by us all according to this method. This is no justification of poor advertising, but it helps to explain why poor advertisements are sometimes successful. Professor James' first method of decision is of the greatest significance to advertisers of all sorts of merchandise, but especially to those who offer goods of a high price and of such a nature that the same person purchases but once or a few times during his life. Among such goods would be included pianos, life insurance, automobiles, and many other advertised articles. Furthermore, the persons who frequently use this first method of deciding are so numerous that it is essential to appeal to the " reason " of the public in exploiting any kind of merchandise. The great diversity in individuals and the numerous motives which influence the same individual, added to the apparent complete freedom of the human will, would seem, combined, to make an insuperable obstacle to reasoning with groups of people by any such means as the printed page. Human choice has always been assumed to be unknown, to be the one indeterminable factor in the universe. In spite of all this we have come to see that human action is governed by known laws and that by carefully studying the nature of so- ciety and the influences at work prophecies may be made within certain limits which are sufficiently accurate for all practical purposes. Under given political, social, and industrial conditions the number and character of crimes remain constant. The suicides distribute themselves in a most remarkable manner, even as to the age, occupation, and sex of the person and the manner of committing tlie crime. The number of marriages each year is more regular than the number of deaths. Famine increases the number of crimes against property and decreases the number of marriages. The wise merchant knows to a certainty from the political, social, and industrial condition of the country that there will be increased or decreased demand for individual lines of goods. Despite all the uncertainty of human choice he knows that there are certain conditions which determine the number who will choose his commodity and take the^ains to secure it. The advertiser is the diplomat of the commercial and industrial world. It is his duty to know the commodity to be exploited and the public to be reached. Even though the commodity to be sold may seem very simple, in reality it is not so. The essential thing in every object is the relations which it has and the functions which it fulfills. The presentation of these relationships and functions in a way that will cause the possible purchaser to respond is a task that is not likely to be overestimated. The same goods may be presented in a score of different ways. The goods remain the same, but the manner of presentation meets with marked differences in the response of the public. One presentation may invite suspicion and another confidence. Suspicion is nothing but an exaggerated tendency to call up possible evil consequences, and confidence is an unusual absence of the same tendency. The text and illustration of the advertisement, the make-up, and the reputation of the medium, etc., all unite to increase or decrease this tendency to hesitate and call up possible evil consequences. The advertiser cannot be too careful in scrutinizing every- thing that goes to make up an advertisement to see that nothing is present which would increase the tendency to recall from the past experience evil consequences which have accompanied other actions. The advertising manager of a publication should refuse not only all dishonest advertisements, but also all those which would tend to make readers suspicious, even if such suspicions were ungrounded. A publication which has been taken in the home for years, which has become trusted because of long years of reliable service, is inestimable in its value to the advertiser. We frequently hesitate to allow time for the suggestion of possible evil consequences, but if such consequences do not suggest themselves in too great a number and with too great vividness, action may follow. Thus persons often respond to advertisements long after they first read them. They could not be induced to respond at once but at a later time they do respond, although there has been no additional ground given for such action. We are all a little suspicious of hasty actions, and the older we grow the more suspicious we become. It is frequently wise not to attempt to secure immediate response, for it requires more effort than it would if the public were given a longer time in which to allay their suspicions. Advertisers are frequently surprised by the few responses which they receive at first from their advertisements and by the great response which they secure at a later time, although the first advertisement was in every way as good as the second. There are persons who will answer an advertisement the first time they see it, but there are many others who will not do so. There are some who will answer the first advertisement but will wait a week or so to answer, others will wait till they see the second or third of the series and then answer. The first time they saw the advertisement there was a personal desire for the goods advertised, but the fear of hasty action was enough to restrain action. At a later time such fear is diminished, and the mere fact that the advertisement had begotten a desire upon its first appearance serves to increase the desire upon the second reading of the same or a similar advertisement. Continuous consecutive advertising ineets the method of response both of those suggestible creatures who act without hesitation and also of those who are too cautious to respond till after sufficient time has elapsed for all the evil consequences to present themselves. It was pointed out above that deliberation often occurs because the presentation of one line of action suggests to our minds another similar and incompatible action. This sort of deliberate action, as also that resulting from a suggestion of evil consequences, is common in actions where large interests are at stake. In purchasing an article that costs some hundreds of dollars most persons would deliberate and consider other goods of the same class. Thus in purchasing a piano or an automobile it is to be expected that no one would be satisfied with the presentation of one make, but would consider each make in relation to others. Although this is true, yet it is the function of the advertiser to get the public to think of one particular article, and the advertiser should in general make no references to competing goods. The buyer may, indeed, think of such goods as might be purchased, instead of those presented in the advertisement, but the advertiser cannot afford to occupy space in furthering this tendency. If the advertisement can be so constructed that it holds the reader's attention to the goods advertised and does not suggest competing goods, it has done much to shorten the period of deliberation and secure decision in favor of the goods advertised. Every slur and every remark intended to weaken the opponent's argument serves to call attention to the goods criticised and thus to divide the reader's attention and so keep the advertisement from having its due weight. It is possible to hold two lines of action before us and, with both thus attended to, to decide for the one and against the other. Such a decision is made with conscious effort, is unpleasing and is not common. We may debate between two courses of action and hold both clearly in mind for some time, but at the moment of decision one course has usually occupied the mind completely and the other, by dropping from the attention, loses the contest, and action in favor of the object occupying the mind is commenced. What the advertiser must do, therefore, is to help the reader to get rid of the necessity of decision by effort, and he can do this by so presenting his goods that they occupy the attention completely. Under such circumstances decision becomes easy and prompt. The parts of an advertisement may weaken instead of strengthen each other. One part of the advertisement may offer a substitute which causes us to hesitate about acting upon another part. It is possible to present two articles which seem equally desirable because too little description is given of the articles advertised. In such a case the reader is unable to make up his mind, and hesitation and procrastination follow until the initial desire for the goods has vanished. " He who hesitates is lost " is a frequent quotation, but it would be more applicable if we should change it to, "The possible customer who is caused to hesitate is lost.^' A single advertisement should not present competing goods unless sufficient argument is given to make it possible for the reader to make up his mind and to act at once. Not only must the advertiser avoid presenting suggestions of evil consequences and possible substitutes for his own commodity, but he must use the greatest skill to discover the conception which in any particular case will lead to action. In Professor James' five methods presented above, the most significant thing in the discussion is the following: ^'The conclusive reason for the decision in these cases usually is the discovery that we can refer the case to a class upon which we are accustomed to act unhesitatingly in a stereotyped way. The moment we hit upon a conception which allows us to apply a principle of action which is a fixed and stable part of our Ego, our state of doubt is at an end." Recently an attempt was made to discover the conceptions which actually are effective in leading persons to answer advertisements and to purchase advertised goods. Upon this point the statements of several thousand perso'ns were examined. The result was most interesting and instructive. Among the effective motives or conceptions the following were prominent : Of these seven reasons it will be observed that the second and last should not be included in the reasoning type. In the second the goods were suggested at the time they were needed and the purchase followed without further consideration. In the seventh the pur- It!' ■'^^toikt take gre.ii satisiat,.;- :. ... ^,,_,., .;,.„a,-P i , ■■ niitl. Fine, «moo!l; texture arte deligJilful to the skin, Jj'!;' . .'-'Soap nmf, iost;iTit(y, leaving a clean absence o\| vertisement. If the right conception is presented at the right time, the desired action will follow. In the reproduced advertisement of Ivory Soap (No. 4) it is assumed that women purchase the soap and that for many of them, including such as the one shown in the cut, the which will sell it. With very many persons it was found that a good investment is the conception which leads to immediate action. Therefore if radiators are presented satisfactorily as a good investment, the question is settled at once and the radiators are purchased. The reproduced advertisement of the American Radiator Company (No. 5 ) , appearing in women's magazines, was evidently constructed on this principle. PuUed Down fUll. «l rtOed as coffM to aucb to luep nu ap, tuvtac pteo told lliu llvUk ••M •ttmalint,' that I hardly knew what to do when I foood il oaa raally pulliDg OM do«» bill. Uy tieep wa> badly broken at ni(hl and I wat all aotUna\|, cxcMdin(lj oonoott •ad breakme down (a«t. My work U teaching acboot. -When it became evident tliit I trai in a very bad condition, I »u induced to lean oS coffee and try Pojlum Food Coffee. Mother made it Snt, but none of ua could ndura It, it wai so flat and laiteleea She proposed to throw the package away, but I aaid, ■ Suepeod judgment until wa have made it ttrictly according to directions.' 11 teeau ahu had made the Poitum like the always made coffee, taking it off the stove as soon aa it began to boiL 1 got titter to make tba Pottum neat morning ttrictly accordia\| to dIcMtloau, that is, allow it to boil full Sflaao minutes after the boiling begins. _ -We were all amaxed at the difference. Sitter taid il wat better ettf, Co bar taa«% than the old, and father, who it an elderly gentleman and had uaed nffea all his tife, appeared to relish the Postum as well aa my UtU* brother, who look lo it from lh« trat We were all greatly improved in health and m now strong advocatea ol Poelum Food Coffee. Please om.l my n.me from pobllcaUon." fUjle, CoL NUM CU b* \|hf« b} Pottttm Ccrtal Co. Ltd., Bsiile Creek, Micb. the efiEectiveness of the conception, health. The reproduced advertisement of Postum Cereal (No. 6) is open to severe criticism. It should be remembered, however, that there are many persons to whom the conception of health is all-powerful. For such this advertisement might be irresistible. enjoyed by their possessors. It is a wise advertiser that can select the conceptions that will fit into the principles of action of the greatest number of possible customers. The term "habit'' has been so frequently confined to a few questionable or bad habits that the broader significance of the term is ordinarily lost. We are all creatures of habit and have some good and some bad ones. It is an interesting study for any one to observe his own actions and thoughts and to see what he does habitually. I tried recently to make such a study of myself, but found that if I should be compelled to record all my liabitual actions and thoughts it would keep a stenographer busy all day and a camera would have to be directed toward me for every move I made. I found that I got out of bed in the morning in a way peculiar to myself. I put on my clothes in a stereotyped order. I put my left shoe on first — I always do. I put my coat on by putting on my right sleeve first, and when I tried to reverse the order I found it very difficult. I picked up the morning paper and glanced over the first page ; then I turned to the last page and from there looked through the paper from the last to the first page and so ended where I had begun. This is my habitual method of reading the morning paper, although I had not observed the fact till that time. I put sugar on my breakfast food first and added cream later. The manner in which I rose from the table, put on my hat and left the house was peculiar to myself. My manner of walking was such that my friends, seeing me in the distance, knew me. I walked down town by the same street wiiich I had been going over for years, although there were several other streets equally good and convenient. I addressed my friends in such a manner that they recognized me even when they did not see me. I took up my work and went through it in a regular routine. The actions as described above were not reasoned out and followed because they were the most rational. I observed my brother's actions at all these points and found that at every point his habits were different from mine. His actions were as reasonable as mine but not more so. Throughout the day I found that the great majority of my actions and thoughts were merely habitual and were performed without conscious desire or deliberation. The fact of habit has been a matter of marvel and wonder for centuries, but an explanation of the phenomenon has been left to modern psychology. If I bend a piece of paper and crease it, the crease will remain, even if the paper is straightened out again. The paper is plastic, and plasticity means simply that the substance offers some resistance to adopting a new form, but when the new form is once impressed upon it, it retains it. Some effort is required to overcome the plasticity of the paper and to form the crease, but when the crease is once formed the plasticity of the paper preserves the crease. There is a most intimate relation between our brains and our thoughts. Every time we think there is a slight change taking place in the delicate nerve cells which compose a large part of the brain. Every action among these cells leaves its indelible mark, or " crease," for the nerve substance is plastic. It is easy HABIT 217 for the paper to bend where it has been creased and it is likewise easy for action to take place in the brain where it has taken place before. That is why it is so easy to think our old habitual thoughts and why it is so hard to think new thoughts or to perform new movements. When a thought has been thought or an action performed many times, the crease becomes so well established that thinking and acting along that crease are easier than other thoughts or actions, and so these easier ones are said to have become habitual. In a very real sense the thoughts and the actions form the brain, and then when the brain is formed its plasticity is so great that it determines our future thinking and acting. This is well shown in the case of language. It is ordinarily true that no one ever learns a language after he is twenty-five years old so well that he can speak it without an accent. As far as language is concerned a person seems to be fixed or creased by the time he is twenty-five and he can never get rid of his former habits of speech. Few men ever learn to dress well unless they have acquired the art in their youth. We all know men who have acquired wealth in middle life and who have tried to be good dressers, but in vain. They go to the best tailors, but something about them betrays their former habits. In all these things we see that we first form our brains, and then when they are once formed (creased) they determine what we shall do and be. This relationship of the mind to the brain in the formation of habits may be illustrated by the paths in a forest. In the densest forest there are still some paths where you can walk with ease. Some person or some animal walks along in a particular direction and breaks down some of the weeds and briars. Some one else follows, and every time that any one walks in this path it becomes easier. Here the weeds and briars are trampled on and kept out of the way. In all the other places the briars have grown up and made it almost impossible to walk through them. Every thought we think forms a pathway through our brains and makes it easier for every other similar thought. We think along certain lines and that is the same as saying that we have formed certain pathways of thought through our brains. It is easy now to think these habitual thoughts, but to think a new thought is like beating a new path through a forest, while to think along the old lines is like following the old paths where advance is easy. We know how easy it is to take the old path and how hard it is to form a new one. We see how easy it is to think the old thoughts and to do the old things and how difficult the new ones are. As habits play such a large part in all of our thinking and acting it is important that the advertiser should understand what habits are and how he can make the most of the situation. He should observe the working of the laws of habit in his own life. If he could realize that everything he does leaves on his brain an impression which is to be a determining factor in all his future, he would, be extremely careful as to what he thinks and what he does, even in private. The success of the advertiser depends to an exceptionally great degree upon the confidence of the public. If we know that a man acts uniformly in an honest manner we have such confidence in him that we call him an honest man and we believe that he will not break his habit of honesty in the future and we are therefore willing to trust him. Thus, whether we think of single actions as determining our future characters or whether we think of them as determining the estimation in which we shall be held by others, there are no incentives to right actions comparable with the inflexible laws of habit when these laws are fully appreciated. The advertiser is likely to " get into a rut " in his line of thinking and consequently in his presentation of his commodity before the public. He should see to it that he does not allow his habits gradually but surely to make impossible to him new forms of expression and new lines of thinking and writing. It takes great and determined effort to overcome an old habit or to form a new one, but the advertiser should in many cases make the necessary effort ; otherwise he is doomed to become an " old fogy.'' The public which the advertiser addresses, is subject to the same laws of habit as the advertiser. Each of the potential customers has formed a rut in his thinking and thinks along that particular line or lines. The advertiser must know his customers. He must know their habits of thought, for it is too difficult to attempt to get them to think along new lines. He must present his commodity in such a way that the readers can understand it without being compelled to think a new thought. The advertisement should conform to their habitual modes of thought, and then the customers can read it and understand it with ease. Habit gives regularity and persistence to our actions. Some people have formed the habit of looking at the last pages in magazines before they look at the others. Some people look more at the right page than at the left. Some glance first at the top of the page, and if that does not look interesting the page is passed by without a glance at the bottom or middle. The wise advertiser his discovery. When game is plentiful and hunters few, any marksman may be successful in bagging- game. As soon, however, as competition becomes keen only that marksman is successful who understands the habits of the game sought and who plans his method of approach according to the habits of the game. When advertising was more primitive than it is to-day and when competition was less keen, any printer or reporter might have been successful in advertising, but to-day no man can be successful who does not plan his campaign according to the habits of the public which he must reach. The action of habit gives great value to advertising by making the effect of the advertisement to be not merely transient but permanent. If an advertisement can get persons started to purchasing a particular brand of goods it has done much more than sell the goods in the immediate present ; for when people do a thing once it is easier to get them to do it again, and habits are formed by just such repetitions. In the first instance the purchaser may have been induced to act only after much hesitation, but after a few repetitions the act becomes almost automatic and requires little or no deliberation. Habitual acts are always performed without deliberation, and there is a uniformity and a certainty about them which differentiates them from other forms of actions. One great aim of the advertiser is to induce the public to get the habit of using his particular line of goods. When the habit is once formed it ^cts as a great drivewheel and makes further action easy in the same direction. It often takes extensive advertising to get the public into the habit, and the amount of sales may not warrant the expense during the first year, but since a habit formed is a positive asset such campaigns may be profitable. The advertiser of Pears' Soap quoted a great truth when he put this at the head of his advertisement, "How use doth breed a habit.'' If he could by advertising get persons to using Pears' Soap he would get them into the habit of using it, and so the advertisement would be an active agent in inducing the customers to continue to buy the soap even long years after the advertisement had ceased to appear. Many advertisers work on the theory that as soon as they have got the public into the habit of using their goods they can stop their advertising and the sales will go right on. There is much truth in this but also a great error. It takes so much effort to form the habit that when it is once formed it should be made the most of. This can best be done by continuing the advertising, thus taking advantage of the habit by securing prompt responses and at the same time taking care to preserve the habit. As was shown in the preceding chapter, we are all creatures of habit. One of the habits which most of us have acquired is that of reading advertisements. The fact that this has become habitual gives it a permanence and regularity similar to that of our other habits. Like other habits, too, we are frequently not conscious of it. I had formed a fixed habit of putting on my right sleeve before the left one, and yet for years I did not know it — would have denied it. People have told me that they never look at the advertising pages of a magazine, when, in fact, they scarcely ever take up a magazine without "glancing" at the advertisements. One lady told me that she was sure she never paid any attention to advertisements, and yet within an hour after making such a statement she was engaged in a conversation about articles which she knew only from statements appearing in the advertising columns of her periodicals. I observed her reading magazines and found that she seldom slighted the advertisements. Thousands of magazine readers read advertisements more than they are aware. I asked several professional advertising men as to the number of persons who read advertisements and the time which people in general devote to them. Some of these men assured me that all persons who pick up a magazine look at the advertisements, and that they put READING ADVERTISEMENTS 223 in as much time in reading them as they do in reading the body of the magazine. I felt convinced that the advertising men were as wide of the mark as the group first mentioned. It is not possible to find out how much other people read advertisements by observing one's self, by asking personal friends, or by asking those engaged in the business of advertising. To know whether people in general read the advertisements or not it is necessary to watch a large number of persons who are reading magazines, to keep an accurate account of the number who are reading the advertisements and of those who are reading the articles in the body of the magazine. The observation should be made on different classes of persons, in homes, clubs, libraries, on trains — wherever and under whatever conditions people are in the habit of reading publications whkh contain advertisements. Some months ago I visited the reading-room of the Chicago Public Library. ^ In this room several hundred men are constantly reading newspapers and magazines— principally magazines. At almost any hour of the day one hundred men may be found there reading magazines. There is a very large number of magazines to choose from, the chairs are comfortable and the light is good. In front of some of the chairs are tables on which the magazine may be rested. There are no conveniences for answering a mail-order advertisement at once, but that might not detract from the reading of such advertisements. Some of the men who read there have but a few minutes to stay, while others are there to spend the day. As I looked over the room to see how many were reading advertisements, it seemed to me that a large part of them were thus engaged. moment, the following plan of investigation was followed. I began at the first table and, unobserved by the readers, turned my attention to the first man. If he w^as reading from the body of the magazine, I took what data I wanted from him, jotted them down in my notebook and then turned to his neighbor and took the data from him, etc. A man was reported as reading the advertisements if he was reading them the very first moment I turned my attention to him„ In every case this first observation determined the points in question. Thus, if I turned my attention to a man who was looking at the last page of the advertisements, and if the very next moment he turned to the reading matter, he was still reported as reading advertisements. On the other hand, tf at my first observation he was just finishing his story in the body ©f the magazine and if during the next few minutes he was engaged in reading advertisements, he was still reported as not reading advertisements. By this system the same results are secured as we should get by taking a snap-shot of the room. We get the exact number who are reading advertisements at any moment of time. Where there was a single column of advertisements next to a single column of reading matter at which the subject was looking, it was sometimes impossible to tell what he was reading. In all cases of doubt the man was not counted at all. There were, however, but few such cases. I made six visits to the library, going on different days of the week, different seasons of the year, and different hours of the day. At each visit I made observations on one hundred men w^ho were reading magazines. Of the first hundred observed, eighty-eight were reading from the body of the magazine and twelve were reading advertisements. Of the second hundred, six were read- ing advertisements. Of the third hundred, fifteen were reading advertisements. Of the fourth hundred, sixteen were reading advertisements. Of the fifth htindred, only five were reading advertisements. Of the sixth hundred, eleven were reading advertisements. Making a summary of the six hundred magazine readers, I found sixty-five reading advertisements and four hundred and thirty-five reading from the body of the magazine. That is to say, 10% per cent, of all the men observed were reading advertisements. At my request a gentleman made similar tests at the same library, and his final results were in remarkable harmony with those given above. Of all the men he observed, exactly ten per cent, were reading advertisements. The fact that only ten per cent, of the men were reading advertisements at any one point of time is not at all equivalent to saying that only one-tenth of them read — or glanced at — the advertisements. A large part of them turned over the advertising pages, but they turned them hastily and did not stop to read them unless in some way they were particularly interesting. Some of the men were looking at the pictures in the advertising pages; some of them were glancing at the display and reading nothing which was not particularly prominent ; others were reading the complete argument of the advertisement. As far as I could tell, most of those who were looking through the advertisements were not engaged in any serious attempt to understand the argument, and were reading in a hasty and indifferent manner. Indeed, it was the exception rather than the rule that any advertisement was read from beginning to end. or proportion of time which the general public devotes to the advertising columns of periodicals. It is quite generally believed that women read advertisements more than men, but in all the tests referred to above, the data were secured only from men. In the second place, it is true that the regular subscribers to periodicals read them more nearly from cover to cover than readers who drop into a library to read. Magazine readers on a train frequently have but a single copy of a magazine at hand, and as trips are usually somewhat prolonged, the traveler frequently not only reads the text matter, but reads many of the advertisements completely. Another element which enters into the question, as here investigated, is found in the fact that among such abundance of periodicals the reader becomes somewhat bewildered, tries to glance through many papers and does not read so carefully as he would ordinarily do under other circumstances. Under these circumstances the data at hand cannot show more than certain general tendencies and certain specific facts as to how one class of readers is in the habit of reading the advertisements in magazines under the conditions mentioned above. The tendency to rush through the advertising jDages of magazines, which was so clearly present in the Chicago Public Library, is, I believe, a general tendencj^ Many people turn every page of the advertising columns of a magazine and read none of the advertisements through. It would not be fair to assume from the data on hand that the average magazine reader spends tenfold as much time on the text as he does on tlie advertisements, but it is quite certain that lie spends a comparatively short time on the advertisements. If the readers in libraries spend anything like tenfold as much time on the text as on the advertisements, and if there is a general tendency with most readers to rush through or glance at the advertisements, it behooves the advertiser to recognize the actual conditions and to construct his advertisements according to the habits of magazine readers. If the presentation of his goods is to be seen but a fraction of a second, that fraction must be made to count. The cut used should be not a mere picture, but an illustration. The cut should be made to speak for I used as'a blind or an awnln^ajr I be pulled up out of (Iglit ll_de_ sired. Slats open and close. 1 Adml(~alir> #Idudr»an. ^ronie SupportlngTapes, non-corroding and most durable. Ordensboold » placed NOW fer J ' H'lLot-i llmdz hax( b,fi J„rnuh,.1 la !),,■)„„„„ cf Charity Lanur, J. P. Morpan. A.G. P'ar.dtrMi, Cii'fUt Ma, lay, i/'« C. H'hiln,,, ff M. FUghr, Mr,. R. Cambrtll, J. Sj Kinntdf, C. ttJ/arJ £U,r, Jam(t C-Cctiali^ O. Harriman, Jr, anijnan/ otktrt\ itself and to tell the story so distinctly that at a glance the gist of the advertisement is comprehended. Thus, in the advertisement of Wilson's Outside Venetians (No. 1), reproduced herewith, the illustration shows just how the ware looks and what it is good for. Even in the most hasty glance the reader is enabled to get a good idea of the appearance and use of this commodity. If he is interested in such goods at all, this knowledge will often lead him to read the entire advertisement. If he passes the goods advertised. but it tells nothing about the goods advertised. I know nothing more about Venus Drawing Pencils after seeing this picture than I did before. Many people look at this picture as they turn the pages of the magazine, and yet they never discover that it has anything to do with pencils. They remember the picture, but do not take the trouble to notice what it is supposed to advertise. Taught by Send today for free test blank «rbfcb enabfes us to advise you wbaC your prosp<^t3 are for success. This (3 the largest, most successful and most tnfluea' tiai institutioQ ti^acbai^tbe science, art andprac* tice of £ulvertisins. Successful stud'-nts everywhere earning doame previous Incomes who learned at home by giving spare time OOly for from three to six months. the gist of the whole matter. Every one who glances at the advertisement understands it. If he sees nothing more than the display of type, he has seen enough to understand what it is all about and to be influenced in favor of the idea there presented. The next time he turns over the pages of a magazine containing this advertisement his attention will be attracted by this familiar display. Every time he sees this advertisement the suggestion in favor of it becomes stronger and yet the reader himself may not be conscious of such influence. Neighborhood About Their Summer Homes. . J[ want a man— or rather three or four men with $3,000 to $4,000 each, who care as much for a beautiful summer home as I do, td) fwrJte me and let me tell them of a property I am holdmg in the most beautiful part of Michigan, for myself and for them, I an» not a real estate agent. I am Just what I here profess to be. a keeker for a beautiful summer home for myself, with good neighlx)rs. ' It won't cost you anything to write to me and let me send: you some photographs and details. And write now, please, as I do not care to advertise this again. Ceorge Mills Rogers, ipoWashmgton St., Chicago, III. In the advertisement reproduced herewith, the type display, "Wanted — Good Neighbors" (No. 4), does not indicate in any way that the. advertisement is one of real estate. A person coi^ld glance at this advertisement a score of times, but he would know no more about it when he had seen it the last time than he did after he had seen it the first time. It has nothing to say to the casual reader, and would be weakened rather than strengthened by repetition. tention, but must tell a story and tell it quickly. The display type and the picture which merely attract and do not instruct are in many cases worthless, for in attracting attention to themselves they divert the attention from the thing advertised. The picture and the meaningless headline will interest some people so much that they will stop and read the advertisement through to try to figure out what it all' means. But the great majority of the readers will not stop at any particular advertisement, and unless they get something at a glance they get nothing at all. A large number of magazine readers see each advertisement, but only a few of them will stop to read it through. The advertiser must learn to make the best possible use of this casual glance of the multitude. Since many see the display and but few read the argument, an attempt should be made to construct a display that will not merely attract attention to itself, but be so constructed that it will beget interest in the goods advertised. Few peoi^le will admit that they are greatly influenced by advertising. I have discussed the question with many persons, and I have yet to find the first one who believes that he is materially influenced by magazine advertising in the purchases which he makes. One great cause for this personal delusion is found in the habit which they have formed of glancing through the advertising pages. They turn the pages rapidly and the individual advertisement makes so little impression that it is not remembered by them as having been seen at all. To say that the advertisement is forgotten is not equivalent to saying that it has not made a lasting impression. If I should glance at the same advertisement in different magazines for each month for a number of years, it is quite possible that these single glances would be forgotten. I might not remember ever having seen an advertisement, and yet my familiarity with the goods advertised might seem so great that I should believe that some of my acquaintances had recommended them to me or that I had used the goods years before. The following instance, which was also referred to in the chapter on Suggestion, illustrates this point perfectly. For years I have seen the advertisements of a certain tailor. Recently I entered his shop and ordered a suit of clothes. It so happened that the proprietor, who was conducting a vigorous advertising campaign, waited on me himself. As he took my order he asked me whether he had been recommended to me. I promptly replied that he had. I then began to try to recall who had recommended him, but found that I could not recall any such recommendation. I had seen his advertisement so often that I had forgotten the particular advertisements, but had retained the information which they had imparted. I had evidently confused the source of my information, for I fully believed that I had heard from some of my friends that this particular tailor was especially trustworthy. If he had asked me whether I had been influenced by his advertisements or not, I might have answered that they had had nothing to do with it, although in fact they were the only source of my information about him and evidently were entirely responsible for the sale. The oftener we see an advertisement, the fewer are the chances that we will remember where we saw it, but the greater becomes our feeling of familiarity with the goods advertised. As soon as we become familiar with the goods in this way and unmindful of the source of the familiarity, we are likely to be subject to this delusion of supposing that we have heard our friends recommend the goods. Most people still are prejudiced against advertisements, and would not purchase the goods if they realized that their only source of information about the firm and about the goods was the advertisement ; but as soon as they forget the source of the information they are perfectly willing to buy the goods, although they would repudiate the statement that they had been influenced by the advertisements. If a merchant should ask his customers whether they had been influenced largely by his advertisements or not, he would certainly receive a very discouraging report, and would be inclined to give up his advertisements as worthless, when, in fact, nothing but his advertisements had induced them to come to his store. The habit which the public has formed of reading advertisements so hastily makes it difficult for the advertisement writer to construct his advertisements to meet the emergency of the case; it makes it difficult for the merchant to discover the direct results of his advertising campaign, and, on the other hand, it makes the right sort of advertising peculiarly effective, by making the reader more susceptible to confusion as to the source of his information. THE DIEECT COMMAND ^'SiMON says, ^Thumbs up !' '' used to be a favorite game with children. In this game one person is "it." He turns his thumbs up and calls out, "Simon says, ^Thumbs up !' " At this command all must obey and turn thumbs up. The one who is "it" next calls out, "Simon says, ^Thumbs down !' " This is the signal for all to turn the thumbs down. If, however, the one who is "it" fails to say "Simon says," he must not be obeyed, and the one who does obey becomes "it" himself. "Simon says" is the reason for obedience, but obedience under any other condition is, in a mild way, punishable. Those of us who have played the game remember that it was impossible for us not to obey the command, even when the "Simon says" was left out. We were commanded to turn our thumbs up or down, as the case might be, and we obeyed before we thought whether the reason for obeying, namely, "Simon says," was given or not. When in our early "teens," my brother and I slept in a room which was not heated. One cold winter night my. brother went to bed first, succeeded in warming his side of the bed, and went to sleep. About an hour afterward, I went to bed and was appreciating the fact that the temperature of the room was below zero, when the thought struck me to play a trick on my brother. I merely said, "John, get over on the other side of the bed." He obeyed immediately and rolled over to the cold side of the bed. I began to laugh and John awoke. It is needless to say what liappened. He knew that he had obeyed me and had done what he did not want to do, and the very thought angered him. • When a person is being hypnotized and is told that he cannot and must not open his eyes, he frequently struggles against the suggestion, but at last succumbs to it. Certain persons are so refractory that they struggle till they '^aw^aken" themselves, unless they are well under the control of the hypnotist. All persons, in all stages of hypnosis, obey the commands of the hypnotist, or are compelled to struggle, to keep from it. The natural and easy thing for them to do is to obey; the unnatural and difficult thing is to keep from obeying. The schoolteacher commands a room full of mischievous children and they obey her, although she could not convince them with reason or compel them with force. They obey simply because they are commanded. The demagogue uses more than flattery, threats, and bribes; he commands his followers absolutely as to what they shall do and what they shall not do. He not only says, "Smith is your friend and Jones your enemy,'' but he gives the command, "Vote for Smith." When certain commands have been obeyed habitually, they attain such a power over our wills that we can scarcely keep from obeying. "There is a story," says Professor Huxley, "which is credible enough, though it may not be true, of a practical joker who, seeing a discharged veteran carrying home his dinner, suddenly called out, ^Attention!' whereupon the man instantly brought his hands down, and lost his mutton and potatoes in the gutter." This soldier obeyed the command until obedience had become almost automatic. He obeyed immediately and without any consideration whatever. In the game alluded to ( "Simon says, ^Thumbs up !' " ) ? in sleep, in hypnotism, and in the cases of the teacher, the demagogue, and the soldier, we have extreme cases. Here the force of the command is so overpowering that obedience is involuntary. These illustrations are useful in indicating the real nature of a command, and in showing how effective it may be when not hindered by competing thoughts. Although commands do not ordinarily secure involuntary obedience, there is a strong tendency in us all to obey them. We have probably all felt ashamed of ourselves for obeying and doing things merely because we w^ere commanded to do so. Stubbornness is the exception and obedience the rule. It often happens that those things which are apparently the most simple are, in fact, the most difficult to comprehend. What could be more simple than the raising of your hand or the turning of your head? If you attempt to analyze the process involved in the simplest movement you find that it is too difficult for your comprehension. We do know something of the psychology of movement, but much is yet to be found out about it. When I want to raise my hand, I do not say, "Hand, come up !" but I know of no way to express what goes on in my mind better than that. I do think of the movement and there is in the thought itself something akin to a command. When I turn my thumbs up, I think of my thumbs turning up, and the thought is the command which I give to my thumbs and which they obey. If the thought is not hindered by a competing thought, — ^if it is allowed to take its own course, — it will be effective in raising the thumbs. In a direct command one person originates the thought and suggests it to another person. Thus in "Simon says, ^Thumbs up !' " I suggest the thought of "thumbs up'' to another person. The thought of ^'thumbs up" enters his mind — is suggested to him, — and unless he hinders the action of the thought it will be obeyed, and up will come his thumbs. One advantage of the direct command is that it suggests a thought in such a way that it will bring forth the action suggested unless hindered by a previous suggestion or by an action originated by the person himself. It is, of course, true that many actions are suggested which are not carried out, because the impelling power of the thought is not sufficiently strong. The impelling power of a thought is in direct proportion to the amount of attention which it secures; and so the impelling power of a command is also in direct proportion to the amount of attention which it receives. If a direct command could occupy the attention completely, it would be the best possible form of argumentation, because it puts the thought in such a shape that its impelling nature will secure the desired results. The command relieves the one commanded from the trouble of making up his mind. It makes up his mind for him, and so makes action easy. A command is a direct suggestion, and as such has inherent value. It is the shortest and simplest form of language, and is the easiest to be understood. It bears with it authority and weight by expressing action explicitly and distinctly. It calls for immediate action and meets with ready response. Mankind as a whole is influenced more by commands than by logical processes of thought, for, as previously stated, we are suggestible rather than reasonable. The command, if not obtrusive, is of such a nature that it has its legitimate uses in advertisements and should not be discarded, as has been frequently asserted. We are not only suggestible and obedient, but we are also obstreperous, obstinate, stubborn, and self-willed. We delight in following our own sweet wills and object to having any one dictate to us. There must, then, be certain limitations put on the use of commands. They must be used with such discretion that they do not arouse opposition ; otherwise we would refuse obedience, even if it were to our best interests to obey. Although we do obey commands, we are unwilling to admit it. We like to think of ourselves as independent beings, who act only because it is the reasonable thing to do and because we want to. It is very difficult for us to analyze our actions and to give the motives which have prompted us to do many of the things that we have done. We act from habit, imitation, insufficient reason, or because the idea of the action has been suggested. It is but rarely that the ordinary person weigh's all the evidence before he acts. After he has acted, he may think over the motives which anight have prompted him, and may even deceive himself into thinking that he acted because he had weighed the evidence, when, in fact, no such motives entered his mind at the time of action. I have frequently suggested to persons that they should do a certain thing. At the time they have refused to do it. The idea was, however, implanted in their minds. Later they have done exactly what I had previously suggested. They had forgotten who had suggested the idea, but the idea itself was retained, so they were perfectly honest in supposing that they had originated the thought, and that they had performed the deed independently. No one would be willing to admit that he had used Pears' Soap simply because he had read the command, "Use Pears' Soap." It is, however, quite probable that many persons have used Pears' Soap for no other reason. The idea of using the soap was had originated it themselves. We are perfectly willing to obey as long as we are unconscious of the fact. But let any one see that he has been commanded and his attitude is changed; he becomes obstinate instead of pliant. Every wise leader of men recognizes this fact. He does not cease to command, but he covers his commands in such a way that each one thinks that he is doing just what he wants to, and that he is not following commands at all. The correct wording of the command is a matter of importance, yet it is difticult to formulate any rules or principles to guide us here. Such an expression as "Use Pears' Soap" is not as suggestive as "Let the Gold Dust twins do your work." The first is a bald command and as such has a certain value, but the second has the added value of supplying, or implying, a reason for obedience. It is implied that the Gold Dust twins will save you labor, and so the command is supplemented by an appeal to a personal interest. Furthermore, this latter command is worded in such a way that it is hardly recognized as a command at all, and so would not beget opposition on the part of an;5C one. As a further proof of the importance, but difficulty, of clothing the command in the best possible form, take the "catch-lines" of four advertisements of advertising schools as they appear in the magazines, which are reproduced upon the following page. The first, "Be an ad-writer," is short, but rather bald and indefinite. The second, "Learn to be an ad writer," suggests that I should become something, and implies that, by a process of learning in connection with their school, this end could be attained. The third, "Learn to write advertisements," suggests that I should learn to do something, and implies that I could learn this by a course of instruction at their school. Personally, learning to do seems more definite than learning to become^ but it is quite possible that it would impress others differently. The fourth, "Advertising writing taught,'' is not a command, and seems to me to be much inferior to the preceding ones. It supplies me with certain information, but does not help me to make up my mind to take the course at their school. It informs me of the fact that they teach advertising, but has nothing to say about action on my part. To have action in another person suggested is not so impressive as it is to have my own action, or action on my part, suggested. The direct personal element is lacking in the last, which is present in the first three. As the young man reads over these four displays his attention will certainly be drawn more forcibly by the first three than by the last one. It might be question- able, however, which one of the first three would appeal most to him. "Learn to write advertisements'' appeals to me most strongly, and would probably appeal to more persons than any of the others. The value of the form of expression in the headlines is clearly seen when we read over the commands which were used as display in American Magazine for April, 1920. Some are good and some are poor, as will be recognized by every one who reads the list. Taking them in the order in which they appeared, they are the following : expressed. Another factor of even greater importance than the verbal expression is the personality of the one giving the command. The spoken command is enforced by the personality of the speaker to an extent impossible in written commands. The difference is, however, not so great as might be supposed. Van Dyke expressed a truth when he said, "Help me to deal very honestly with words and people, for they are both alive." The person who can move men by spoken words can move them by written words. This is so true that many have prophesied that the press would render the preacher and the orator useless. The printed page is a living force which is more appreciated to-day than ever before. There are men who are obeyed whether they speak or write, whether they are at the head of a regiment or in the privacy of their own homes, whether they are addressing their employees in person or presenting certain lines of action to the public by means of printed advertisements. Certain persons can command us and we obey readily, but if the same commands were given by other persons, we should regard it as presumptuous and refuse obedience. A firm that is just beginning its first advertising campaign does not secure as much attention to its advertisements as the older firms. Furthermore, reliable firms which are well established and well known through advertising could give commands with impunity which would injure a new or unknown firm. Persons who are used to obeying take obedience as a matter of course and obey almost from second nature or instinct. Those who are not used to being commanded are more inclined to resent the attempt and so refuse to obey, even if the command is in accord with their interests, and if they had at first been at the very point of obeying. A form of expression which would prove highly successful with one class of society might fail with another class. Commands would have a greater efficiency in cheap than in higher-priced periodicals, because the poorer classes are more in the habit of obeying commands. They are more in the habit of doing things that are directly suggested to them. All classes of society are moved by a direct command if it is properly worded, and if it appears in their favorite or most highly appreciated publication. action. There is nothing which attracts the attention so much as movement or action. When we want to attract the attention of a friend, we wave to him instinctively. We know that he will see the wave of the hand or of the handkerchief when he would not notice us at all apart from such movements. Our eyes are so constructed that we can distinguish a movement of an object before we are able to distinguish the object itself. Movements please and attract us in whatever form they may be presented. A shop window that has in it a live animal or anything else that moves will attract the attention of the pedestrian as he passes by. A command ordinarily calls for action. As we read a command we think of the action suggested and it attracts our attention in much the same way that actual movements do. In the first case we see with the imagination what we see in the second case with the sense of sight. A command in good display type at the beginning of an advertisement may express in a few words the intent of the entire advertisement. It expresses it in such a living, moving manner that it attracts our attention and makes us feel in sympathy with it, so that we feel like doing what is suggested at once. This tendency to action on our part brings us into sympathetic, personal relation with the advertisement, and so gets us interested enough in the advertisement to start us to reading it. The argument should be so constructed that it brings us into closer relationship with the proposition offered. It should take us into the confidence of the firm and make us feel that the firm back of the advertisement can be trusted. We then feel in sym- pathy with the offer made by the firm, our self-will is suspended, and we are in a condition to do w^hat is suggested. The argument may have been extensive, the illustrations may have been interesting and suggestive, but now what is wanted is immediate action. The advertisement should focus at this point. An attempt should be made to hold our attention to what is desired of us. The value of a direct command at this point should not be overlooked, as it expresses in a few w^ords and in living form all that the advertisement has desired to bring about. It sums up the entire argument and puts it before us in the form of a direct suggestion to action. Outdoor advertising must of necessity be very brief and very suggestive. There is no opportunity to present extensive arguments, yet something must be done to attract attention and to beget immediate action. Direct affirmation as to the value of the goods offered may, in general, be the most effective form of expression, but the direct command could be used with profit because of its superior value in attracting attention and in begetting immediate action. The above chapter on '^The Direct Command" as a form of argumentation appeared in substantially the present form in Makings Magazine. Soon after its publication the Editor received a letter from the Franklin Mills Company, saying that they were going "to try out the theory'' in their advertising. Some time later the following letter was received, stating the results of their experiment with the advertisement reproduced herewith (No. 2) : We wish to say that our February advertisement, embodying "the direct command" advised by Professor Scott, is bringing far greater returns than any advertisement we have ever before published, and this is surprising in the face of the fact that the public are overloaded with free samples of hundreds of what they want. Another instance of the successful application of this principle appeared in a recent issue of Printers^ Ink. It is entitled, "A Story of Progress," and gives the history of the wonderful growth of the Delineator: period, cMefly to spread the well-known catch-phrase, "Just get the Delineators^ This phrase originated with Mr. Thayer, who, in speaking about it, said: "I had tried more than a year to hit upon a suitable phrase, but nothing would come to me. One day I read an article by Professor Scott in Mahin's Magazine, in which he showed that if the words 'Cut this coupon out and mail it to-day' were used instead of 'Use this coupon' there would be a larger number of replies. It is his theory that people will follow a definite direction of this sort, and the theory appealed to me. So I formulated my phrase in the belief that its suggestion would be followed, especially by women. Results have proved that it is an effective phrase. To my own personal knowledge the catch-line has tantalized even men until they bought copies to see the publication for themselves." RETUEN COUPON. The return coupon, which is the product of a long evolution in which necessity and practical experience were the prime moving factors, has of recent years been greatly improved by those who have been able to analyze it and to appreciate its possibilities. Before the days of the coupon, the advertiser met with great difficulty in trying to keep tab on the various publications in which he advertised. The "Please mention this magazine^' was frequently disregarded, and so the idea was conceived of having something returned to the advertiser which would indicate the publication in which the sender had seen the advertisement. At first it was the whole advertisement which was to be returned, and we find at the end of some of the old advertisements this statement, "Please cut this advertisement out," etc. Then it was conceived that it was not necessary to return the entire advertisement, but merely a blank for the name and address, and so the coupon was evolved. The return coupon was, then, in the beginning a keying device and was not intended to have any value as a means of securing replies. It was not to induce the reader to answer the advertisement, but was intended as an assistance to the advertiser in keeping tab on the various publications in which he advertised. Later it was discovered that the coupon had a greater value than had been supposed — that it was in itself a strong induce- ment to action and that its value was therefore psychological. The coupon appeals directly to the reader and induces more to answer the advertisement than would do so if the coupon were not there. it attracts attention. In their original form these coupons (No. 1) were something different from anything that had previously appeared in advertisements, and attracted attention by way of contrast to ordinary advertisements. They also attracted attention because the ruled blank lines and open spaces were in contrast with the rest of the advertisement. The coupon is so familiar now that it does not offer so strong a contrast to other advertisements as formerly, but is still in contrast to the rest of the advertisement in which it is con- VALUE OF THE RETURN COUPON tained. To make this latter contrast stronger, the whole advertisement, as well as the coupon itself, has been greatly modified. The chief alteration was in the coupon, which was changed from the square or oblong to the triangle (No. 2). All the lines of reading matter are horizontal, but the little three-cornered coupon has one or more oblique lines, and the oblique lines run in a Mr. Ralph Tilton states /,// ^ that this was the first tri- //Y f ) angular coupon ever used.] Ay/ M I asked a large group of persons to think of some number. Very many more of them thought of three than of any other number. I have asked other groups to think of some geometrical figure, and more think of a triangle than of any other figure. I have exposed, for a very short interval of time, various geometrical figures, and the triangle catches their attention more than any other figure. The number three and a figure with three sides possess a peculiar interest for us. It seems^ then, that the triangle is more attractive than a square, and oblong, or parallel lines, and so it attracts our attention to itself and indirectly to the advertisement in which it is contained. The shape of the entire advertisement and particularly the shape of the border has been changed to make the contrast with the three-cornered coupon greater. By certain leading advertisers the border has been constructed of figured designs composed of broken curved lines, or of continuous curved lines, or else the border has been discarded entirely (No. 3). These changes make the bold, straight lines of the coupon stand out in marked contrast, and are almost sure to attract the attention as one turns over the page. The contrast between the coupon and the rest of the advertisement (not to mention the contrast with other advertisements) is not the only source of attention value of the coupon. A second attractive feature is found in We've a pamphlet, prepared by the publishers of rtie history, which Idls just what ibe work is, how it came to be written, and the tort of readers it aims to entertain and interest. This pamphlet also conums specimens of the illustrations and feat pages, and ii fOuYe interested, and mail us the coupon, we'll send it to vottl btt of cost Reading that pamphlet will settle in your mind, < lor all, whether you need the history or not ; and you best settle it ^0W, for this is our last aitvertlMneat of Ridpatb'* History M bait prUe. the direct command ordinarily placed between the body of the advertisement and the coupon. The expressions "Cut this corner off,'' "Cut along this line," etc., have a decided value in attracting attention. ( See chapter on "The Direct Command as a Form of Argumentation.'') Another source of attention value in this kind of advertising is in the dotted line indicating the place at which the coupon should be cut off. This dotted line suggests action, and as such is interesting and attracts the attention. If the dotted lines could give the impression of perforated paper, the results would be better. Where possible it would be well to have the paper perforated along the line where the coupon is to be torn ofe. Another source of attention value in this kind of advertising in its modified form is found in the devices employed (No. 4) to direct the attention to the dotted line or to the "Cut this corner off.'' The index fingers, all pointing to the same thing, give one the impression that there must be something very special at that point, and many persons look to see what the fingers are pointing at, when otherwise they would pass the entire advertisement by without noticing it. In addition to its power in attracting attention, the return coupon has a further psychological value in that it gives the reader something definite mid specific to do. I have frequently observed in teaching that if pupils or students are given definite and specific tasks to perform, they perform them with alacrity. If, however, the tasks are made general and assigned as something which they might do sometime, no impression is made on their minds and nothing is done. A necessary characteristic of a teacher is the ability to make his students know just what he wants them to do. A prime requisite of an advertisement, when direct evidence of attention is desired, is that it should give the reader something definite and specific to do at once, i.e.^ that the reader should open a correspondence with the firm. With our present knowledge there could probably be no better way of making that end clear than by the use of the return coupon. Its function is much like that of a sun-glass. The rays of the sun falling on a piece of paper will warm it, but will not cause it to burn. If the rays are allowed to shine through the sun-glass and to focus at one point of the paper, the whole will soon be ignited. The argument in an advertisement may be good, it may even make the reader 'Varm'' with the desire to secure the goods, but his desire may not result in action. The heat was not focused at one point. The return coupon concentrates all this desire or ^'warmth" at one point; it overcomes procrastination and secures the necessary action. There are persons who will climb the Matterhorn because of the difficulty of the ascent. There are those who will spend hours and even days trying to solve difficult puzzles. These are but apparent exceptions to the universal rule that mankind as a class prefers the lipe of least resistance. We desire the best results, but we want to secure them with the least possible labor. We refuse to take two steps when one is sufficient. Business men recognize this fact and place their merchandise where it can easily be secured by the buyer. They choose a site for their stores where they will be the most accessible. They arrange their goods so that they may be most easily seen and secured by the public. They send out their representatives to display the goods and leave nothing to the purchaser but to indicate what he wants. In short, everything possible is done to make it easy for the customers. The traveling salesman made it so easy for the customer that he undoubtedly gave orders for goods which he would not have purchased if he had been obliged to go after them or even to write a letter for them. For a mail-order house, the return coupon supplements or takes the place of a traveling salesman. It presents itself to the possible customer, and all he has to do is to fill it out and return it, and the goods are forthcoming. Even for the experienced business man it is easier to fill out a blank than it is to dictate or write a letter. But all are not experienced business men. There are those who make good customers, but whose only formula for letter writing is, ^'I take my pen in hand to let you know that I am well and hope that this will find you the same.'' For such a person to compose a business letter is a task of no small importance. He does not know whether to begin with ''Dear Sir" or with ''Gentlemen" ; he does not know whether he should close with "Yours truly" or "Affectionately yours." The betrayal of his ignorance and the effort of composition are hindrances of such magnitude that he is frequently deterred from securing the desired goods. To be relieved from this embarrassment and toil is for him a veritable boon. The return coupon makes answering easier for all, whether with or without experience in writing business letters. It makes ansAvering easy not only because it has the return letter already composed, but also because the composed letter is easily accessible. Some advertisers do not seem to appreciate this latter advantage and so allow the coupon to be placed near the middle of the page and on the inside of it — next to the binding. The following reduced reproduction is an example of such a blunder ( No. 5 ) . This makes it unnecessarily difficult to get at, and so places an obstacle in the way of every one who desires to answer. Many would surmount the difficulty, but some would not. It certainly is bad business policy to put such a needless obstruction in the path of every "would-be customer." The three-cornered coupon can be cut or torn off more easily than any other. If placed on one of the four outer corners of a publication it can be severed with a single cut of the scissors or torn off with a single tear. It is more accessible than it would be if in any other shape ; it makes the answering of the advertisement easy, and to that extent is the best possible shape for a return coupon. The task recently devolved on me of purchasing a baby carriage. I had never been interested in them before and did not know where I had ever seen them in stores, and so did not know where I should go to secure one. I turned at once to the advertisements in the morning paper and saw baby carriages advertised at a certain down-town store. I went there at once and asked the floor-walker where they kept them, and he politely informed me that they did not handle them. I assured him that I had seen their advertisement in the paper that morning and that they must therefore have them. He made further inquiries and found that they did have them, and I secured my desired article. Having seen the advertisement in the paper, it was easy for me to find what I wanted. All advertisements make it easy for the purchaser to know where the class of goods is kept which he desires to secure. It will readily be seen that . one of the great functions of any advertisement is in this way to make it easy for the purchaser to find what he wants. The coupon has the additional value of being of such a nature that the purchaser can secure the goods desired without going out after them and even without the trouble of composing and writing a letter. Some of us are not so lazy as others, but we are all procrastinators. We often decide that we want a thing, but we put off the purchase till the desire has gone and so we never secure what we wanted. Procrastination is so easy that we put off till to-morrow what would cause us trouble to do to-day. With the coupon, the task of ordering the goods is so easy that there is almost no excuse for procrastination, even if we are somewhat lazy. An advertisement should make it as easy as possible for the purchaser to secure the goods he desires and should take away every possible ground for hesitation. In these particulars the coupon is especially strong. We have now seen that the coupon attracts attention because of its novelty or contrast, because of its triangular shape, because of the direct command and the index finger which frequently accompanies the return coupon. We have seen that it is psychologically strong because it is specific and direct in its appeal. We have also seen its strength in that it makes answering the advertisement easy and calls for immediate action. All these advantages are but supplementary and subsidiary to the great function of the return coupon. Its real value is to be found in the fact that it suggests to the reader that he should sign his name, tear out the coupon and send it to the address given. The prime value of the coupon is lost unless this is attained. The coupon does attract attention, but that is of value merely because in attracting attention it brings the suggestion to the mind of the reader and keeps it there. It is specific atid direct, but that is of value only because it holds before the mind the one specific suggestion which is desired. It makes action easy and that is good, because Check the edition of Price List you wish sent (will send bodi tf desired), also articles whfch you handje or use, so that we can send samples and special inforsaMon fr«n time to time. then no barrier is placed in the way of the suggestion. It calls for immediate action and that is essential, because unless the suggestion is acted upon at once it grows weaker and would fail of its purpose. pons there should be some mention made of other similar devices for suggesting action. Among these latter are the return postal card, the money envelope, the money card, etc. There seems to be no end to the number of such devices that skill and ingenuity may discover. They are used with great profit by their inventors, but when the novelty has worn off, they are less valuable, and other forms are then demanded. This chapter in substantially its present form appeared first in a magazine article. One of the readers of the magazine decided to make an experiment in applying the principle to his own business. He noticed this sentence, ^They are used with great profit by their inventors, but when the novelty has worn off, they are less valuable, and other forms are then demanded." He tried to preserve the psychological value of the return coupon, but to present it in a new form and in such a way that it would be adapted to his demands. The result of his labor is seen in No. 6. Evanston, 111.: Dear Sir, — I am sending you under separate cover copy of the "Ballot" advertisement, which we got out recently along the lines suggested by your articles in Mahin's Magazine, and are pleased to report that the returns are very satisfactory. Over 50 per cent, of the sheets were returned, making a very valuable mailing list, but we do not consider this as important as the psychological value of having the retail dealers make a special request for our monthly price list. As a test case, we mailed thirty of these sheets to dealers to whom we had been sending our catalogues and other advertising material regularly for a number of years, but had never received any returns. Of these seventeen were returned, three containing special requests for prices, one of which resulted in an immediate order. I find the knowledge of the psychological principles of advertising very helpful in planning my advertising work, and will be pleased to give you any further data in regard to the results obtained that you may wish. J. C. WOODLEY. At the time this chapter was prepared for publication in magazine form (May, 1902) there were but few return coupons appearing in the current magazines, and those appearing were placed with but little regard to position. Thus in Miinsey's Magazine for May, 1902, there were but three return coupons, and one of them was so placed that it came next to the binding and would be hard to detach. In McCliire's for the same month there appeared four return coupons and one of them was next to the binding. In the Century Magazine for the same month there appeared but a single return coupon. Since that date the number of return coupons has increased enormously. Very often a hundred return coupons appear in a single issue. ATTENTION What does the advertiser seek to accomplish by his advertisements? The answers to this question differ merely as to form of expression or point of view. One says, "The aim of advertising is to attract attention and to sell goods." Another statement would be that the purpose of advertising is to attract attention to the goods and to create such a favorable impression for them that the reader will desire to possess them. Whatever the statement may be, this seems certain — one aim of every advertisement is to attract attention. Therefore, the entire problem of attention is one of importance to the advertiser, and an understanding of it is necessary for its wisest application as well as for a correct understanding of advertising. When we turn to the question of attention, the first thing that impresses us is that our attention is narrow, that we are unable to attend to many things at once. Out of all the multitude of things competing for place in our attention, the great majority is entirely disregarded. At the present time you are receiving impressions of pressure from your chair and from your clothing, impressions of smell from flowers and from smoke, impressions of sound from passing vehicles and from your own breathing, impressions of sight from your hand that holds this book and from the table on which the book rests. As I mention them they are noticed one after the other, Before T mentioned them you were totally oblivious of them. You cannot say how many distinct things you can attend to at once. This was formerly a question of frequent debate. Some asserted that we could attend to but one thing at a time, but others, with equal vehemence, insisted that a score of things could be attended to at once. The question has been removed from the realm of mere probability, for it has been investigated according to scientific methods in the psychological laboratories, and definite results have been obtained. Ordinary observers under favorable conditions can attend to about four visual objects at once. ^^Object" here is used to indicate anything that may be regarded as a single thing. About four letters, four simple pictures, four geometrical figures or easy words are as much as we can see or attend to at once. As you look at this page the light is reflected to your eyes from each individual word, so one might say that you receive an impression from each of the words on the page, but if you look at the page closely you will find that you can attend to but about four words at once. If, then, there are multitudes of things to be attended to and we are unable to attend to more than four at once, why do we attend to certain things and disregard all the rest? What characteristics must anything have that it may force itself into our attention? Since advertisements are part of the things which may or may not be attended to, we may be more specific and put the question in this form: What must be the characteristics of an advertisement to force it into the attention of the possible customer? If I am interested in guns, take up a magazine, look for the advertisements of guns and read them through, my attention is voluntary. If, while looking for guns, something else catches my eye for a moment and I think "that is an advertisement for clothing/' then my attention is involuntary. In the first case I sought out the advertisement with a conscious purpose. In the second there was no such conscious purpose, but the advertisement thrust itself upon my attention. Psychology is the newest of the experimental sciences and the investigations of involuntary attention are as yet far from satisfactory. The complete analysis of it as applied to advertising has to my knowledge never been made. With its complete analysis the following six principles will appear: of counter attractions. Other things being equal, the probabilities that any particular thing will catch our attention are in proportion to the absence of competing attractions. This may be demonstrated in a specific case as follows : I had a card of convenient size and on it were four letters. This card was exposed to view for one twenty-fifth of a second, and in that time all the four letters were read by the observers. I then added four other letters and exposed the card one twenty-fifth of a second as before. The observers could read but four letters as in the previous trial; but in this exposure there was no certainty that any particular letter would be read. I then added four more letters to the card and exposed it as in the previous trials. The observers were still able to read but four letters. That is to say, up to a certain point all could be seen; when the number of objects {i.e., letters) was doubled, the chances that any particular object would be seen were reduced to fifty per cent. When the number of objects was increased threefold, the chance of any particular object being seen was reduced to thirty-three per cent. If I should place any four particular letters on the right-hand page of any magazine, and also the same four letters on the opposite page, and have nothing else on these pages, it is safe to say that the letters would be seen, with more or less attention, in one or both cases by every one who turns over the pages of the magazine. This follows, because at the ordinary reading distance the field of even comparatively distinct vision is smaller than a single page of ordinary magazine size, and as one turns the pages the attention is not wider than the page and therefore the letters have no rivals and would of necessity fill or occupy the attention for an instant of time, or until the page was turned over. If one hundred of these letters were placed on each of the pages, the chances that any particular letter would be seen are greatly reduced. This seems to indicate that, other things being equal, the full-page advertisement is the "sure-to-be-seen^' advertisement, and that the size of an advertisement determines the number of chances it has of being seen. This principle, which holds for the parts of a page, might not hold for adjoining pages. Thus it might not be to the advantage of an advertisement to be the only advertisement or the only one of a certain class of goods in any periodical. If there were eight advertisements of automobiles on a single page, the casual reader would probably see but one or two of them. If there were eight full-page advertisements of automobiles on adjoining pages of the same magazine, even the casual reader would be likely to see them all. Whether each of these eight full -page advertisements would be as effective as one would be if it were the only one in and will be taken up at a later time. If on a single page there are but few words set in display type, and if these words stand out with no competitors for the attention of the reader, the chances Colorado the ideal country for seekers after health and pleasure Send for our "Handbook of Colofadp." A trip to Colorado costs but littla. Our handbook tells all about th» \|>rices for board and the attractions at different places. ' Send for a copy TO-DAT. No charge. At the same time I will mail you a circular telling about the very cheap tickets we are selling to Colorado. Round trip fron» Chicago, $25 and $30; from St. Louis, $21 and $25, according to the data. It takes but one night on the road from either Chicago or St. Louis to Denver. jP. 8. EUSTIS. PaMenger Traffic Mwtagv C. B. & Q. R/. Co.. Chicago. are in favor of any particular person reading this much of the advertisement. Thus, in the advertisement of the Burlington Railroad reproduced herewith (No. 1), the words "Cool off in Colorado" stand out without having to compete with any counter attraction. If this idea causes the reader to stop but for a second he will next see the display "Burlington Route'' and then "Send for our Handbook of Colorado." No one of these displays competes with the other, but each assists the other. In the advertisement of Dr. Slocum, as reproduced herewith (No. 2), there is so much put in display type and in so many styles of type that nothing stands out clearly and distinctly. Each individual display seems to screech at the reader as he turns the page. The result is that the ordinary reader feels confused, and turns away from such a page without any definite idea as to what it is all about. Each display is a counter attraction to each other one, and so the effect of all is weakened. the sensation aroused. The bright headlight of the locomotive and the red lanterns which are used as signals of danger arouse such strong sensations that we simply must see them. Moving objects produce a stronger sensation than objects at rest. This accounts for the introduction of all sorts of movement in street advertising. Certain colors attract attention more than others. Prof. Harlow Gale has made some experiments to determine what the attention value of the different colors is. He has found that red is the color having the greatest attention value, green is the second, and black is the third. Large and heavy types not only occupy a large amount of space and so force attention to themselves by excluding counter attractions, but, in addition to this, they affect the eye and give a strong sensation and thereby attract the attention. Experiments have been made to' find the attention value of the differentsized type. It has been found that, within the limits of the experiments, the attention value of display type increases in almost exact proportion to the increase of its size. The eye is like a photographer's camera. If it is focused for any particular object, all others appear through it to be blurred and indistinct. My hand, held to the extreme right or left, is then seen so indistinctly that I cannot count the fingers. Objects that fall under the direct gaze of the eyes make stronger visual impressions than those which fall out of the focus. The former ordinarily attract the attention, the latter seldom do. As one turns over the pages of advertisements, those which fall directly within the focus of the eye have the best chance of attracting the attention. An important question for the advertiser is : Where does the ordinary reader direct his eyes as he turns the pages of a magazine? Does he begin at the front or at the back of the magazine? Does he turn his eyes first to the top or to the middle or to the bottom of the page? Are his eyes turned more to the right or more to the left of the page? These questions have been the subject of frequent discussion, but they never have been subjected to sufficiently extensive investigation. The third principle is that the attention value of an object depends upon the contrast it forms to the object presented with it^ preceding or following it. The contrast produced by a flash of lightning on a dark night, or by the hooting of an owl at midnight, is so strong that the attention is absolutely forced, and there is no one who can disregard them. Novel things and sudden changes of any sort are noticed, while familiar things and gradual changes are hardly noticed at all. This is a matter of common experience, but has been strikingly illustrated with frogs. The following quotation is taken from a recent work of the director of the psychological laboratory at Yale University: "Although a frog jumps readily enough when put in warm water, yet a frog can be boiled without a movement if the water is heated slowly enough. In one experiment the water was heated at the rate of .0036 of a degree Fahrenheit per second; the frog never moved and at the end of two and one-half hours was found dead. He had evidently been boiled without noticing it." My explanation of these results is that at any point of time the temperature of water was in such little contrast with the temperature a moment before that the attention of the frog was never attracted to the temperature of the water at all ; so the frog was actually boiled to death without becoming aware of the fact ! As we turn the pages of a magazine we do not see each page as an independent unit, but we see it in relation to what has gone before. If it is in marked contrast to the preceding there is a sort of shock felt which is in reality the perception of the contrast. This element is a constant force in drawing the attention. What has been said of the full page is equally true of the parts of it. In the case of magazine or newspaper advertising, the responsibility for making effective contrasts is shared alike by the individual advertiser and by the "make-up." Contrasts may be so harmoniously formed that the things contrasted are mutually strengthened, just as is the case when red and green are placed in juxtaposition. The red looks redder and the green looks greener. But if the contrast is incongruous the value of each is impaired. Thus if two musical but mutually discordant tones are sounded together or one after the other, the beauty of each is lost. No one has been conscious of this principle of contrast to a greater extent than the advertiser. He has introduced all sorts of things into his advertisements merely to attract attention through contrast : He has inserted his advertisements upside down; he has had the lines of the reading matter run crosswise ; he has substituted black background for the ordinary wliite. The inherent skill of the American advertiser has been made manifest by this ingenuity in devising novel, ever-changing, and striking contrasts. Indeed, some have followed this principle too far and have produced novelties and contrasts, but their work has not been successful, because they have violated other equally important principles. Thus the advertisement of the Burlington Route employs the principle of contrast successfully. The advertisement of Dr. Slocum makes use of the same principle, but the result is nothing short of a botch. The three principles as given above are important and are the three methods which the practical advertiser uses most to attract attention. The three which shall be given next are methods which are of almost equal importance, but which are frequently disregarded by the writers of advertisements. The fourth principle is that the power which any object has to attract our attention, or its attention value, depends on the ease with which we are able to comprehend it. This principle is one which is often neglected by the advertiser. A few illustrations will help to make it clear. A child in turning over the pages of a book or magazine does not have his attention attracted at all by the printed words. Even the pictures do not attract his attention unless they are in bright colors or represent something which he can understand. The same thing is true with adults. We will turn our attention to nothing unless it speaks to us in terms which we can interpret with comparative ease. It is difficult to comprehend an entirely new thing or function. From this it follows that a new article should be introduced as a modification of a familiar one, or as something performing a well-known function. The pedagogical maxim of always advancing from the known to the unknown is so well established that its violation must be regarded as more or less suicidal. Styles of lettering that are not easily read and cuts that are not easily interpreted are not so attractive as lettering and cuts that are more simple and transparent in their meaning. background that the whole is an indistinct blur. As an example of an advertisement that is good as to individual details but poor as to the entire effect, we have reproduced herewith (No. 3) an advertisement of the Purina Mills. Cloth not so fine may not wear quite so long: an out-of-style bonnet is xinwearable. If you cannot afford mahogany, maple will do; but poor varnish is death to the beauty of anything. it would otherwise be. The name or brand of goods often makes them difficult to advertise. Thus Orangeine does not suggest what the Orangeine Chemical Company would have it suggest. People do not know what it is, and so fail to be attracted by the advertisement simply because it is meaningless to them. Many advertisers have used certain forms of expression and illustrations which bear no necessary relation to the rest of the advertisement or to the goods advertised. They have been called "irrelevant words'' or "irrelevant cuts," as the case might be. Their function is presumably that of attracting attention. As they stand, they are not easily comprehended, and actual experiment has shown that they do not attract the attention of one hastily looking at the page of the magazine as often as relevant words or relevant cuts. The advertisement of the Murphy Varnish Company, as reproduced on page 271 (No. 4), has made use of a form of display which we would call "irrelevant words." This display has nothing particular to do with varnish. It could be used equally well with almost any advertisement appearing in magazines to-day. It would, however, be equally poor in any case. It does not increase the reader's knowledge concerning the proposition which the varnish company has to offer, and the ordinary reader would not be likely to be attracted by any such "catch-words" as these. The advertisers of the White Star Coffee (No. 5) have filled up one-half of their space with the picture of a slimy frog. When one is thinking of frogs he is not in condition to listen to the arguments in favor of any coffee. But, aside from such considerations, I believe that there is no proof that such an open attempt to force the attention of the reader is advisable or successful. The advertisement of the American Lead Pencil Company, as reproduced herewith (No. 6), has made use of cuts that illustrate. Such an illustration is called a relevant cut. The casual reader sees at a glance what this advertisement is all about, and such advertisements attract us instantly. The great majority of all advertisements appearing at the present time make use of words in display type which indicate in brief what the entire advertisement is about. Such headings are called relevant words. The picture which tells the story is more easily comprehended than any possible expression in words. This is one reason why the picture is the most attractive form of advertising- diction to the third principle. A thing which is in contrast to all other things and yet frequently repeated meets both conditions. The psychological explanation of the value of repetition is somewhat involved, but the fact is seen by every careful observer. The questions concerning repetition as applied to advertising are as yet unsettled. In the case of goods having an equal sale all the year, if a given advertisement is to appear one hundred times, is it best to insert it in one hundred different magazines once, so that the reader can see it in all his periodicals for a few days, or is it better to have the same advertisement appear in one hundred different issues of the same magazine? In other words, are repetitions more effective if they follow rapidly one after the other, or if they are separated by a longer period of time? Another question is this : How much of an advertisement should be repeated? Some advertisements have unchangeable characteristics which are always repeated and which serve to identify all the advertisements of a particular house. Others are completely changed as to all prominent features with every issue, and the casual observer would not notice that the two successive advertisements were for the same goods — he certainly would not notice that they were from the same house. Still other advertisements have certain prominent features which are constantly changing, but which are always recognizable as representing the same firm. The advertisement which is the same from year to year is lacking in contrast. It is not necessarily ineffective, but it takes^ time to accomplish its results. The frog that was boiled without noticing it succumbed at last to the slowly rising temperature. The man who sees the same advertisement month after month will at last purchase the goods advertised without ever having paid any particular attention to the advertisement and would be unable to say why he purchased those particular goods. The advertisement which is changed completely with every issue is lacking in repetition value and would be good only when it is of such a nature that a large per cent, of the intended purchasers would read it thoroughly enough to supply the missing links and to unite it to the others of the series. The advertisement with a constant recognizable feature that varies in detail from time to time allows for both change and repetition, and is to that extent the best advertisement. I Print niy Own Cards Circulars, Newspaper. Press ^5. r,nrger size, 918. Money saver. lUg profits printing for others. Type setting easy, rules sent. Write for catalog* presses, type, paper, etc., to factory. This advertisement of a printing press company (No. 7) has, so far as I know, never been changed. It is just the same in all publications in which the firm advertises, and is the same year in and year out. It has doubtless been more or less successful. Would it have been more effective if the copy had been changed? The two advertisements of the Franklin Mills (Nos. 8 and 9) have nothing in common. No one but a careful reader would know that they were advertisements of the same firm. This same firm has been careful to have the wheat border in all advertisements of Wheatlet. The seal containing the 'portrait of Franklin is also often present in the advertisements of Wheatlet. Would it not be advisable to retain this wheat border or the seal in all advertisements issuing from this firm? If certain readers had become interested in the advertisements of Wheatlet, for instance, and had become familiar with the characteristic seal, they would be attracted by the other advertisements of this firm if they saw the seal down in the corner of the advertisement. Very many firms are at the present time changing their copy frequently, but they retain some characteristic feature so that we can recognize the new advertisements as old friends in a new form. Thus the Cream of Wheat advertisements are identified by the Wheatlet the best cereal. Whether you lead a strenuous life or not. Wheatlet will do you more good than any breakfast food you can ent. Start the New Year right. "All the JJ'Jiratthafs Fit to Eat," f^Ixl g,^70QSpringarden St.. LocKPORT. N Y. $200 is to be given Children. Write, us. genial colored chef. I have come to like that chef, and am attracted by every advertisement in which he appears. If he were left out, I should not be so likely to notice the advertisement as I am with him in it. Each of their advertisements is in a sense new and in contrast with all their other advertisements, but this col- Attention is not merely a process in which the mind grasps a certain fact, but it is also a process in which we feel. It is either a pleasurable or a painful feeling. That a thing may attract our attention it must not affect us indifferently, but must either please or dis- please us. At this point the work of the true artist becomes essential. In the ideal advertisement the emotions and sensibilities of the possible customers must be appealed to. In all advertisements the esthetic feelings may be aroused by at least the harmonious combinations of color and form. Curiosity, pride, sympathy, ambition, and many other feelings and emotions have been awakened by the skillful advertiser. With certain advertisers the desire seems to have been merely to attract attention regardless of the emotion awakened. They have been successful in attracting attention, but their advertisements are so obtrusive and repulsive that their value, as a means of selling goods, is inconsiderable. The man who confines himself to the simple statement of facts may not be subject to the mistakes that befall the man who attempts more difficult things. The photographer presents all the details of a scene, but he does not appeal to the emotions and the heart of the public as the artist does. The work of the photographer may be truer to the facts, but the work of the artist attracts our attention more readily. We do not understand the feelings and emotions of the human breast, and yet it is often advisable to run the risk of attempting appeals to the emotions. There are scores of advertisers who attempt to appeal to the joyful emotions. It should be remembered that joy is but one of the emotions. The visitor to an art gallery is at once struck by the frequent appeal to the sadder emotions. It is not at all easy to find in our magazine advertising any appeal or any reference to the more pathetic aspects of life. The following is a reproduction (No. 10) of an advertisement of the Prudential Insurance Company. This advertisement does not ap- -pear in recent magazines, yet it is certainly much better than many highly approved advertisements of insurance companies. The skillful advertiser should be able to appeal to more than one emotion and he should be able ris hard enou^-h on a woman to be thrown on her own resootcft. The death of the husband and father is quite enoug;h by itself. If the burden of debt and want be added to it, the woman's life is hardly worth the living. Comparatively few men in America are able to accumulate any money. Perhaps not one in a hundred does it.- It is this that makes life insurance an imperative necessity. Nobody can take the insurance money away from tlie one to whom you make it payable. It will not assuag;e the grief, Jiut ■t will increase the comfort of those who are living. It discharges, to some extent, the obligation every man incurs when he marries. Our two forms of life insurance, the "Industrial" (for policies of $tOOO or less, on weekly payments) and the "Ordinary" (for policies of $1(XX) and more, quarterly, semi-annual, and annual payments), are clearly explained in our booklets — sent free on request. offered. The designer of advertisements must be something more than a skilled artisan; he must be an artist and must be able to put soul into his work, so that his production will appeal to the sentiment as well as to the art demands the work of an artist. Such is in brief the discussion of the six fundamental principles underlying the psychology of involuntary attention in general, and the psychology of involuntary attention as applied to advertising in particular. The purpose of this chapter is to present in an introductory manner the psychology of a part of advertising, i.e.^ involuntary attention, and with special reference to magazine and newspaper advertising. What is the comparative attention value of advertisements next to reading matter and of advertisements segregated at the beginning and the end of magazines? What is the comparative attention value of space among classified advertisements and of space among unclassified advertisements, or advertisements of a different class of goods? Is the additional attention value secured by tinted paper, colored type, and colored cuts sufficient to warrant their increased introduction? How does repetition affect the attention value of an advertisement? How complete should the repetition be and how often and how rapidly should the advertisement be repeated to secure the best results? Such is a brief syllabus for future investigation upon involuntary attention as applied to advertising. These questions can probably all be answered, some easily and others only after difficult and extensive investigations. It is quite plain that investigation on these questions would be of the greatest practical value to the advertiser. OF LAEGE SPACES There are certain things which seem to force themselves upon us whether we will or not. We seem to be compelled to attend to them by some mysterious instinctive tendency of our nervous organization. Thus moving objects, sudden contrasts, large objects, etc., seem to catch our attention with irresistible force. Again there are certain conditions which favor attention and others which hinder it. Among the conditions favoring attention the following is, for the advertiser, of special significance. The power of any object to compel attention depends upon the absence of counter-attraction. In the preceding chapter appeared the following paragraph : ^^Other things being equal, the probabilities that any particular thing will catch our attention are in proportion to the absence of competing attractions. This may be demonstrated in a specific case as follows : I had a card of convenient size and on it were four letters. This card was exposed to view for one twenty-fifth of a second, and in that time all the four letters were read by the observers. I then added four other letters and exposed the card one twenty-fifth of a second as before. The observers could read but four of the letters as in the previous trial, but in this exposure there was no certainty that any particular letter would be read. I then added four more letters to the card and exposed the letters as in the previous trials. The observers were still able to read but four letters. That is to say, up to a certain point all could be seen. When the number of objects (i.e.y letters) was doubled, the chances that any particular object would be seen were reduced fifty per cent. When the number of objects was increased threefold, the chances of any particular object being seen were reduced to thirty-three per cent. If I should place any particular four letters on the right and also the same letters on the left hand page of any magazine and have nothing else on the page, it is safe to say that the letters would be seen, with more or less attention, in one or both cases by every one who turns over the pages of the magazine. This follows because at the ordinary reading distance the field of even comparatively distinct vision is smaller than a single page of ordinary magazine size, and as one turns the pages the attention is ordinarily not wider than the page, and therefore the letters have no rivals and would of necessity fill or occupy the attention for an instant of time, or until the page was turned over. If one hundred of these letters are placed on each of the pages the chances that any particular letter will be seen are greatly reduced. This seems to indicate that, other things being equal, the full-page advertisement is the ^ sure-to-be-seen ' advertisement and that the size of an advertisement determines the number of chances it has of being seen." Even a casual reader of advertisements is aware of the fact that full-page advertisements attract attention more than smaller advertisements. Every advertiser knows that if he should occupy full pages he would secure more attention than if he should occupy quarter SMALL AND LARGE SPACES 285 pages, yet one of the most perplexing questions which any advertiser has to deal with is the adequate amount of space for any particular advertisement or for any particular advertising campaign. The question is not as to the superiority of full pages in comparison with smaller spaces. All- feel sure that any advertisement would be more valuable if it occupied a full page than if it occupied only half of it. But the real question is whether it is twice as valuable, for it costs practically twice as much. A quarter-page announcement is valuable, but a half-page is worth more — ^is it worth twice as much? It is of course conceded that some advertisements are unprofitable regardless of the space occupied, and that others are profitable when filling various amounts of space. It is also conceded that certain advertisements require a large space and that others are profitable as an inch advertisement but would be unprofitable if inflated to occupy a full page. There are exceptions and special cases, but the question can be intelligently stated as follows: Of all the advertisements being run in current advertising, which is the more profitable, in proportion to the space occupied, the large or the small advertisement? Since profitableness is a very broad term and depends upon many conditions, we will for the present confine ourselves to one of the characteristics of a profitable advertisement, i.e.y its attention value. The quotation presented above was deduced from a theoretical study of attention, before opportunity had been offered to verify it by means of experiments with advertisements. To investigate the question the following tests were made : I handed each of the forty students in my class a copy of the current issue of the Century Magazine. I then asked them to take the magazines and look them through, just as they ordinarily do, but not to read any poetry or long articles. Some of them put in all their time reading advertisements ; some glanced through the advertisements, read over the table of contents and looked over the reading matter; a few failed even to look at the advertisements. At the end of ten minutes, I surprised them by asking them to lay aside the magazines and write down all they could remember about each of the advertisements they had seen. I sent the same magazines to other persons in other parts of the country and had them use the magazines in the same way in which I had used them. In this way tests were made with over five hundred persons mostly between the ages of ten and thirty. These results were carefully tabulated as to the exact number of persons who mentioned each individual advertisement. We then got together all references to each particular advertisement and so could compare the different advertisements, not only as to the fact of bare remembrance, but also as to the amount of information which each had furnished, the desire it had created to secure the goods, etc. At the present time we shall consider all advertisements mainly from the standard of attracting attention sufficiently to be recalled by those who saw them. Out of the ninety-one full-page advertisements, sixtyfour of them are advertisements of books and periodicals, while of the half-page, quarter-page, and small advertisements there is a total of about five pages devoted to books and periodicals. To compare the full-page advertisements with the other advertisements in this particular magazine would be to compare advertisements of books and periodicals with advertisements of other classes of goods. To obviate this difficulty, we shall di- books and periodicals. The twenty-seven full-page advertisements of goods other than books or periodicals were remembered (mentioned in the reports of the five hundred persons tested) five hundred and thirty times, which is an average of approximately twenty for each advertisement. The sixty-four full-page advertisements of books and periodicals were remembered six hundred and six times, which is an average of nine times for each advertisement. The thirty-nine half-page advertisements of goods other than books or periodicals were mentioned three hundred and fifty-eight times, which is an average of nine times for each advertisement. The sixty-seven quarter-page advertisements, other than those of books or periodicals, were mentioned two hundred and twenty-three times, which is an average of three for each advertisement. The three quarter-page advertisements of books and magazines were mentioned only twice, which is an average of less than one for each advertisement. As less than a single quarter-page of small advertisements was of books and periodicals, it is useless to consider such advertisements separately. There are ninety-eight small advertisements, and these were mentioned but sixty-five times, which is an average of much less than one for each advertisement. The inefficiency of the small advertisement is made more striking when we consider that for all advertisements other than for those of books and periodicals a full page was mentioned approximately twenty times, a half -page nine times, a quarter-page three times, and a small advertisement less than a single time. As is shown in the following table of all advertisements other than those of books and periodicals, a quarter-page advertisement was mentioned thirty per cent, of tener than a quarter-page of small advertisements; a half-page advertisement was mentioned eighty per cent, oftener than a half-page of small advertisements; and a full-page advertisement was mentioned ninety per cent, oftener than a full page of small advertisements. When we consider the advertisements for books and periodicals, the differences are enormous. A half-page advertisement was noticed fifty per cent, oftener than two quarter-page advertisements, and a full-page advertisement was mentioned two hundred and fifty per cent, oftener than four quarter-page advertisements. An advertisement was regarded as "remembered" if it was mentioned at all. In some instances the illustration alone was remembered and the person mentioning it was unable to tell what advertisement the illustration was used with. In a few instances the illustration of one brand of goods was interpreted as an advertisement of the competing brand. On the other hand the results were frequently astounding in their revelation of the effectiveness of the advertisements in imparting the essential information and creating a desire for the goods. The cut (No. 1) is a reproduction of the sessing great attention value. report of one of the pupils in Minneapolis, made after she had looked through the magazine for ten minutes without the knowledge that she would be called upon to report on what she had read. The advertisement described by this pupil was mentioned more than any other and is reproduced herewith as No. 2. vised to see whether similar results would be secured from a more diversified list of advertisements and from the class of persons for whom the advertisements were especially written. We took the binding wires out of a large number of magazines and thus were able to make a collection of advertising pages without tearing the margins of the leaves. We made use of magazines of different years and of different kinds, but all used were of uniform magazine size. From these leaves we chose one hundred pages of advertisements, being careful to choose as many different styles of advertisements as possible. We had in these pages advertisements of almost everything which has been advertised in magazines of recent years. We had all the different styles of display, of type and illustration, of colored cuts and tinted paper, etc. We had these hundred pages bound up with the body of a current magazine, and the whole thing looked like any ordinary magazine. Indeed, no one suspected that it was "made up" as he looked at it. This specially prepared magazine was handed to fifty adults. A large number of them were heads of families, readers of magazines, and purchasers of the goods advertised. Thirty-three of them were women and seventeen men. Some of. them lived in a city and some in a country town. As we had tried to choose all the different kinds of advertisements possible, so we tried to get all kinds and conditions of people for subjects. With three exceptions, the subjects knew nothing of the nature of the experiment. Some of them knew that it was for experimental purposes, but some of them merely took the magazine and looked it through, supposing that it was the latest magazine. Each one was requested to look through the magazine and, in every case tabulated, all the hundred pages of advertisements were turned. Some of the subjects turned the pages rapidly and got through in three minutes, others were thirty minutes in getting through. The average time for the fifty subjects was a little over ten minutes. As soon as each subject had completely looked through the magazine it was taken away from him and he was asked to "mention'^ all the advertisements which he 'had seen, and to tell all about each of them. What he said was written down, and then the subject was given the magazine again and asked to look it through and indicate each advertisement which he recognized as one which he had seen but had forgotten to mention. There was very great diversity in individuals in their ability to mention the advertisements which they had just seen. Some of them mentioned as high as thirty different advertisements; one man was unable to mention a single advertisement which he had seen, although all the one hundred pages of advertisements had been before his eyes but a moment before. There was also great diversity in subjects in their ability to recognize the advertisements when they looked through the magazine the second time. Some of them recognized as high as one hundred advertisements when looking through the second time and were surprised that they had forgotten to mention them. Others, in looking through the second time, were surprised to see how unfamiliar the magazine looked. One subject, who mentioned but three advertisements, could recognize only three others. He had no recollection of having seen any of the others. This would seem to indicate that certain persons may turn over the advertising pages of a magazine and yet hardly see the advertisements at all. The forty-three pages of full-page miscellaneous advertisements were mentioned two hundred and eightyone times .and recognized five hundred and forty-four times. That is, each of these advertisements was mentioned on an average of 6\|f times and recognized on an average of 12\|\| times in addition. The thirty-one full-page advertisements of books and periodicals were mentioned eighty-five times by the fifty subjects, which is an average of 2\|\| times for each advertisement. The thirty-one full pages were recognized (upon looking through the magazine a second time) two hundred and seventy-six times by the fifty subjects, in addition to the ^^mentions." Each of these advertisements was thus recognized on an average almost nine times. The fifteen half-page advertisements of miscellaneous advertisements were mentioned forty-one times, which is an average of 2^^ times for each. The fifteen advertisements were recognized one hundred and eighteen times in addition, which is an average of 7yf times for each one. There are but four half -page advertisements of books and periodicals, and only one of them was mentioned by any of the fifty, and that but once. That gives an average of one-fourth mention for each advertisement. They were recognized by twenty-four, which is an average of six for each advertisement. The thirty-six quarter-page miscellaneous advertisements were mentioned thirty-nine times, which is an average of 1^2^ times for each advertisement. They were recognized one hundred and twenty-two times, which is an average of 3f g^ times for each. There are six quarter-page advertisements of books and periodicals. These six were mentioned only three times, which is an average of one-half for each advertisement. The ninety-three small miscellaneous advertisements were mentioned fourteen times, which makes an average of fourteen ninety-thirds. They were recognized thirtyfour times, which is an average of thirty-four ninetythirds for each advertisement. Of the small advertisements, only seven were of books and periodicals; these seven were mentioned once, which is an average of oneseventh for each. The seven were recognized only twice, or on the average of two-sevenths. As is shown by the foregoing, for all kinds of advertisements, with but one exception, a full-page advertisement was mentioned oftener than two half-page advertisements, two half -page advertisements were mentioned oftener than four quarter-page advertisements, and four quarter-page advertisements were mentioned oftener than a full page of small advertisements. The exception referred to is the half-page advertisements^ of books which fell below all other-sized advertisements, but as the number of "recognized'^ is very large, the apparent exception should not be emphasized. Although an advertisement had not impressed the reader sufficiently to enable him to mention it after he had closed the magazine, yet it may have made such an impression on him that he could recall it if a need or something else should arise to suggest it to his mind. Thus, to find out how many of the advertisements had made any appreciable impression, we had each subject see how many of the advertisements in the magazine he could recognize a few minutes after he had looked through it for the first time. The results given aJ)ove indicate that a quarter-page advertisement was recognized oftener than a quarter-page of small advertisements; that a half-page advertisement was recognized oftener than two quarter-page advertisements; but that the full-page advertisements in three instances were recognized less often proportionately than smaller advertisements, i.e., half -page and quarter-page miscellaneous advertisements and half-page advertisements of books and periodicals. These three exceptional instances are of no significance inasmuch as the full-page advertisements had been previously mentioned and therefore had been excluded from those that could be merely recognized. The report given by each subject was carefully analyzed to see how many times each advertisement impressed a subject sufficiently so that he would know at least what general class of goods the advertisement represented. Upon comparing the reports upon the different advertisements at this point, it was found that the subject knew what class of goods the full-page advertisement represented much better than what the half-page represented; that the half -page was better than the quarterpage, and that the quarter-page was better than the small advertisement. Results were then compiled as to the comparative values of the different-sized advertisements in impressing upon the subjects the individual brand or name of the goods advertised. It was found that this information was imparted much better by the larger advertisements. In a similar way, results were compiled as to the name and address of the firm, the price of the goods offered and the line of argument presented by the advertiser. In all of these cases it was found that the full-page advertisement was more than twice as effective as a half-page advertisement ; a half-page was more than twice as effective as a quarter-page, and a quarter-page was more effective than a quarter page of small advertisements. ^ The full-page advertisements, which were mentioned by the greatest number of subjects were Ivory Soap (mentioned twenty-four times and reproduced herewith as No. 3), In-er-Seal (mentioned twenty-three times), and Pears' Soap (mentioned twenty times, reproduced herewith as No. 4). Of the twenty-four persons who mentioned Ivory Soap (No. 3), but sixteen knew that it was an advertisement of soap at all, and only fourteen as mere display advertising. knew that it was an advertisement of Ivory Soap. Of the twenty- three persons who mentioned In-er-Seal, only sixteen knew that it referred to biscuits, while but nine knew that it was an advertisement of In-er-Seal goods. The advertisement in question is the familiar one of a boy in a raincoat putting packages of In-er-Seal in a cupboard. Of the twenty persons who mentioned Pears' Soap (No. 4), every one of them knew that it was an advertisement of Pears' Soap. Only five of the full-page advertisements were mentioned by none of the fifty subjects. These five were of the New York Central Railroad (No. 5), Egyptian Deities Cigarettes, Waltham Watches (No. 6), Equitable Life Assurance Society, and the Lyman D. Morse Advertising Agency. There TThe New'YorV G^nfr.-il does not chim to be ih* only railtoad in the world — "rhere jre others . ii is. however, the gre^t Four-trjck Trunk line of the United States. And. has earned the title given it by press and people on both '5ides of ihe Atlantic, of "America's Greatest Railroad." The New York Central is the direA Line between the American metropolis and Ni.>g.?r.i F.ills. hy w.iu of Ihe historic Hudson River and through the beautiful Mohawk Valley. "The entire Main Line of theNew York Centr.ii, between New York and.BuflUIo and Niagara Falls, is proteifled by the most pet1fe<3Lsystem of block signals in the world." were very many half-page, quarter-page, and small advertisements which were mentioned and recognized by none of the fifty persons tested. The results indicated a very great difference between individual advertisements which filled the same space. Quality is more important than quantity. Certain styles of advertisements ( depending upon the goods advertised as well as on other things) are effective in any space, and others are comparatively worthless, even if filling a full page. An advertiser should certainly give more heed to the quality of his advertisement than to its size, yet the size is an important element. but little attention value. In the case of these one hundred pages of typical advertisements, the size of the advertisements affected their value materially. In the number of times the advertisement was mentioned from memory, in the number of times it was recognized when the magazine was looked at for the second time, and in the number of times that the advertisement conveyed definite information as to the general class of goods advertised, the specific name or brand of the goods, the name of the firm, the address of the firm, the price of the goods, and the argument presented in favor of the goods — in all of these points (disregarding the exception mentioned above) the full-page advertisement was more than twice as effective as the half-page ; the half-page was more than twice as effective as the quarter-page ; the quarter-page was more effective than a quarter page of small advertisements. - In other words, at all points considered in the two investigations described above, the value of an advertisement increases as the size of the advertisement increases, and the "increase of value is greater than the increase in the amount of space filled. In the preceding chapter it was shown that the larger advertisements attract the attention much more than the smaller ones. The larger ones also offer more opportunity for relevant text and appropriate illustrations. The larger advertisements are best for imparting the desired information and for making a lasting impression on the possible customers. Many business men, however, believe that the small advertisement is safer than the larger one and that the larger spaces are luxuries reserved for those who are able to incur losses without serious consequences. If the users of large spaces are reckless and the users of small spaces cautious and conservative, we should naturally suppose that the more conservative firms would be the ones which would stay in business longest and which might be looked for in each successive year in the advertising pages of certain magazines. There is a tradition that the users of advertising space are, as a whole, rather ephemeral, that they are in the magazines to-day, and to-morrow have ceased to exist. There are, on the other hand, persons with perfect faith in advertising who believe that all a firm has to do is to advertise and its success is assured. This chapter presents the results of extensive investigations carried on to ascertain more definitely the stability of advertisers and to discover which sizes of advertisements seem to be the safest and most profitable. MORTALITY RATE OF ADVERTISERS 303 Buffalo and advertising in the Ladies' Home Journal for a period of eight years. All firms were grouped together which had appeared in this magazine but one of these years, all which had appeared two of the years, all which had appeared three of the years, etc., up to and including all of the firms which had appeared the eight years under consideration. After a careful analysis had been m^de the following significant results were secured : 600 lines This would seem to indicate that in general if a firm uses fifty-six lines annually in the Ladies' Home Journal the results will be so unsatisfactory that it will not try it again. If it uses one hundred and sixteen lines annually it will be encouraged to attempt it the second year, but will then drop out. If, on the other hand, it uses six hundred lines annually the results will be so satisfactory that it will continue to use the same magaziiie indefinitely. (A very large number of the firms who continued in eight years continued in for a longer time. ) There were but 1,247 firms included in the data presented above. Other data were secured from the entire number of firms advertising in the Ladies' Home Journal, the Delineator^ Harper^s, and Scrihner^s for certain periods, but inasmuch as the data from all these merely confirm those presented above they are not added here. Advertisers are in general wise business men and are usually able to tell whether their advertising pays or not. If it pays, they continue it ; if it does not pay, they cease to advertise. Every one can think of an occasional exception, but in general the statement is correct. That class of advertising which is the most successful is the class most likely to be continued. That class which is the least successful is the least likely to be continued. The survival of the fittest is as true in advertising as it is in organic nature. If large spaces are more valuable in proportion to their size than small spaces, we should expect to find the larger spaces surviving. If the smaller spaces are more valuable in proportion to their size we should expect to find the small spaces surviving. What has been the experience of advertisers — especially of magazine advertisers — on this point? It is a debated question whether there is a growing tendency toward larger or smaller advertisements. In articles in magazines for business men the statement is often made that we are finding it unnecessary to use large spaces, but that small spaces well filled are the more profitable. To find out definitely what the tendency is in regard to the use of space, several investigations have been carried on. We shall, however, confine the discussion to the question as it manifests itself in the Century Magazine. We have chosen the Century because it is one of the best advertising mediums, because it has had one of the most consistent histories, and because all the files have been made available from the first issue of the magazine. We have conducted similar investigations, but in a less thorough manner, with several of the leading advertising mediums in America. In each one of these investigations we have secured results similar to those presented below from the Century. The following data, therefore, show a general tendency ; so the data and discussion are not to be interpreted as having any special reference to the Century Magazine. In preparing the tabulation, school announcements and announcements made by the publishers of the magazine were disregarded. In the following table the first column indicates the year, the second column the total number of pages devoted to commercial advertising during that year in the Century Magazine, the third column the total number of firms advertising in the magazine that year, the fourth the average number of lines used by each firm during the year, the fifth the average number of lines in each advertisement appearing in the magazine for that year, the sixth the average number of times each firm advertised in the Century for that year. Several things in this tabulation are worthy of careful consideration. The total number of pages devoted to advertising has been increasing very rapidly till now there are over one thousand pages devoted to advertising annually as compared with two hundred pages which was the approximate amount during the first ten years of the existence of the magazine. With the exception of the years of financial distress in the nineties almost every year has shown an increase over the preceding year. The growth has been so constant and has been sustained for so many years that it would seem to be nothing more than a normal growth. The increase is seen to be greatest in the years of prosperity, while during the years of depression there is usually a decrease. The second point to be considered in the tabulation is the number of firms which advertised in the magazine in the years from 1870 to 1907. It will be noticed that during the first ten years there were about two hundred firms advertising. From 1880 to 1890 the increase was extremely rapid. In 1880 there were but two hundred and ninety-three firms, while in 1890 there were nine hundred and ten firms advertising in the same magazine. From 1890 there has been a rapid falling off till in 1907 there were but three hundred and sixty-four firms advertising in the magazine. During the year 1907 fewer firms were advertising in this magazine than for any year for a quarter of a century. Although the decrease has been but slight during the recent prosperous years, we can but wonder what will happen when a period of years comes which is less prosperous, such years, for instance, as those of the early nineties when the number of firms was so greatly reduced. The question naturally arises as to the possibility of nine hundred firms advertising successfully during a single year in the same magazine. Perhaps it is possible, but it certainly has not been attained in 18901907; otherwise the firms would not have discontinued their contracts. Certain advertising managers have seen the difficulty of crowding so many advertisements into the two groups at the front and the end of the magazines and have sought to avoid the difficulty by scattering the advertisements through the reading matter. In this way all advertisements are in some magazines placed "next to reading matter." The proof is not conclusive that this method of scattering the advertisements is of any great advantage. The point made clear by the fourth column of the table is that of the increase in the amount of space used annually by each advertiser. The fifth and sixth columns show that this increase is not due to the more frequent insertion of advertisements, but to the increased size of the individual advertisements. Until indicated. About the year 1890 the real struggle for existence set in among advertisements, and that is the time to which we must look for the survival of the fittest. If the small advertisements had been the most profitable, then the users of small spaces would have survived and would have appeared in the following years. Such, however, is not the case. In that fierce struggle the small spaces proved to be incapable of competing with the larger spaces, and we find in the succeeding years that the users of small spaces grew gradually less. This is shown by the fact that although the number of advertisers has decreased, the amount of space used has increased. This process is still continuing. The year 1907 was almost identical with the year 1890 as to the total advertising space, but showed a decrease of sixty per cent, in the number of firms advertising, while the average amount of space used by each advertiser has increased one hundred and fifty per cent. This pronounced increase in space and decrease in the number of advertisers is perhaps the most astounding fact observed in the development of advertising in America. It is not to be assumed that the size of a poor advertisement will keep it from failure any more than the age of a consumptive will be of supreme moment in determining his probable length of life. Neither is it to be assumed that all classes of merchandise can use full pages with profit and that no classes of business can be more successful when using small spaces than when using larger ones. The point which should be emphasized is that the size of an advertisement is one of the vital elements and that every advertising agent or manager should be an advertising expert and should be able to give advice as to the size of an advertisement ticular firm with any particular text and illustration. The advertising agents and managers should not only be experts, able to give such advice, but they should have such confidence in their own judgments that they would refuse to handle the business of any firm which insisted on using spaces which court failure. Every failure is an injury to the advertising medium, and the results of a failure should be looked upon as such a serious matter that periodicals which proved unprofitable in a large proportion of cases would be avoided. Physicians are regarded as experts along a certain line, and if patients refuse to follow their advice they not infrequently refuse to treat them further. The lawyer is an expert along another line and he assumes his client will take his advice, and is ordinarily correct in his assumption. There is no good reason why the advertising manager or agent should not be looked upon in the same way. If he is sincere in his judgments, and if he has taken account of the advertising experience of the many and not of the few, he should be able to assist the prospective advertiser in avoiding the pitfalls which have been the destruction of a very large proportion of all firms that have attempted to advertise. Advertising can no longer be said to be in its infancy. It has now reached mature years, and it is high time that the professional advertising men should awake to their responsibility and display the same wisdom that is displayed by the physician and the lawyer. A physician prides himself not only in the number of his patients, but also in the low death-rate of his patients. I believe that the day is soon coming, and indeed is now here, when the advertising managers of our periodicals will pride themselves in the low mortality-rate of their adver- tisers rather than in the total number of advertising pages appearing monthly. , In the end the magazine which has the lowest mortality-rate will of course be the most profitable both to the buyer and to the seller of space. Because of the psychological effect produced by the larger spaces, and because of the comparative values of large and of small spaces as given above, it is evident that one of the duties of the advertising manager and agent is to insist on the use of adequate space and to be able to advise what is adequate space in any particular case. NEXT TO READING MATTER One of the most perplexing and widely discussed problems in magazine advertising to-day is this : Is advertising space segregated at the two ends of the magazine more valuable or less valuable than space next to reading matter? Among my friends who are advertisers or who are in advertising agencies there was neither a consensus of opinion nor sufficient data for reaching a satisfactory conclusion. For the purpose of securing more data, the following letter was sent to the leading advertisers and agencies using space in American magazines : Northwestern University, August 23. Dear Sir, — Certain influential manufacturers with national distribution are convinced that an advertisement placed next to reading matter (such as an interesting story) is placed in a preferred position. Other manufacturers prefer to have their advertisement located in the section of the publication set aside for advertisements. Their conviction is based on the theory that good reading matter and good advertising matter on the same page conflict. Both parties to the dispute seem to base their faith upon opinion rather than upon fact. The question is one of such great importance to the science of advertising that I feel justified in asking for your co-operation in an attempt to secure the truth. 1. Do you know of any evidence (facts and not opinions) that advertising next to reading matter is of greater value to the advertiser than advertising space massed at the two ends of the magazine? tory to you. A letter similar to this is being sent to some of the leading advertisers in America. If you so desire I will report to you an analysis of the answers, so far as is consistent with the confidential nature of the replies. Eeplies were received from five hundred and eighty advertisers and from one hundred and ninety-six agencies. In some instances several members of the firm sent separate answers. Each of these is listed as an independent reply. Of the five hundred and eighty advertisers, thirty -four, or almost six per cent., present facts to prove that advertising space in the segregated advertising sections is of more value than space next to reading matter. Of the five hundred and eighty advertisers, sixty, or almost ten per cent., present facts to prove that space next to reading matter is more valuable than space in the segregated advertising sections. Of the five hundred and eighty advertisers, fifty-four, or a little less than ten per cent., present no facts, but express the opinion that space in the segregated advertising sections is more valuable than space next to reading matter. Of the five hundred and eighty advertisers, one hundred and thirty-one, or a little over twenty-two per cent., present no facts, but express the opinion that space next tising sections. Of the five hundred and eighty firms, three hundred and one, or almost fifty-two per cent., assert that there is no difference in the value of space in the two classes of magazines ; that they are undecided in their opinion, or fail to include in their reply any facts or expression of opinion bearing on the topic. Of the one hundred and ninety-six advertising agency respondents, twelve, or a little over six per cent., present facts to prove that space in the segregated advertising sections is more valuable than space next to reading matter. Of the one hundred and ninety-six advertising agency respondents, twenty-seven, or a little less than fourteen per cent., present facts to prove that space next to reading matter is more valuable than space in the segregated advertising sections. Of the one hundred and ninety-six agency respondents, nine, or a little less than five per cent., present no facts, but express the opinion that space in the segregated advertising sections is of more value than space next to reading matter. Of the one hundred and ninety-six agency respondents, fifty-four, or twenty-eight per cent., present no facts, but express the opinion that space next to reading matter is more valuable than space in segregated advertising sections. Of the one hundred and ninety-six agency respondents, ninety-nine, or almost fifty-one per cent., present no facts, but express the opinion that there is no difference in value between space in segregated sections and that next to reading matter; that their evidence is not conclusive; or they present neither facts nor opinions. Of the one hundred and ninety-six agency respondents, five present data from one group of clients indicating the superiority of segregated space, and from another group of clients indicating the superiority of space next to reading matter. These five firms are, of course, included in both the six per cent, and the fourteen per cent, as presented above. dred and one, as five presented data on toth sides of the debate. Extracts are presented herewith from typical examples of the thirty-four letters from advertisers who present facts to prove the superiority of space in segregated advertising sections. Taking the magazines on our list in which it is customary to put the advertising matter next to reading matter, such as Leslie's, Literary Digest, and McClure's, and comparing the returns from these magazines with the ones in which the advertising pages are grouped in the back and front of the magazine, such as the World's Work, System, Review of Reviews, Cosmopolitan, Outlook, etc., I find that each sale from the magazines in which advertising appeared next to reading matter cost us 9.7 per cent, more than in the other group. Also, that the cost per inquiry increased 57.4 per cent, in the next-to-reading magazines. I further find that the average number of inquiries received from magazines which group the advertising increased 41.1 per cent, over the average number of inquiries received from magazines in which the advertising appears next to reading matter. In the magazines which figured in the above statistics we used the same series of advertisements, each advertisement appearing once in each of the magazines, but not necessarily in the same month. The whole series was run in each of the mediums, though. (Insurance.) In the standard magazines which carry a large advertising section, such as Everybody's and System, we have found that our advertisements when massed with the advertisements of the business world in a definite advertising section, that is, not cut up with reading matter, have proved to be more effective and more powerful to get results. We have reason to believe that in the standard magazine size publications of this nature, the policy of massing the advertisements in a bunch is much better for both the reader and the advertiser. (Typewriters.) The only evidence on which we can base our opinion is that of the number of inquiries which we receive from advertisements. In the Post, for instance, in which our advertisement was placed next to reading matter, the inquiry cost was $7.50, and in the Literary Digest, in which the advertisement was placed next to reading matter, the cost was $3.50. In the Cosmopolitan the cost per inquiry was $3.41. In this magazine, as you know, the advertisements are all together. You will probably be interested in the attached summary covering our advertising for the fiscal year beginning July, 1914, and ending June, 1915. The following extracts are from the sixty letters of advertisers presenting facts indicating the superiority of advertising space next to reading matter : Referring to your circular letter of the 23d, in answer to your question number one: We consider an advertisement placed next to reading matter has at least fifty per cent, more value than a similar advertisement buried in the midst of a heavy advertising section. , Second: Our records are in such shape that we cannot very well give you the data concerning this, but we have found invariably that the replies from any given advertisement are much greater when situated as above than when buried in the advertising section. (Fountain Pen.) In 1914 we made up our list on an entirely different basis than in previous years. We used twenty-nine publications and we made effort to secure positions next to reading matter. Publications such as the Cosmopolitan and Everybody's we had used for years, but we dropped them from our list on the theory that very few readers would take the trouble to wade through one hundred or more solid pages of advertising. We give preference to publications that run reading matter and advertising matter on the same page, although we used McClure's where the advertising was opposite reading matter. With a few exceptions, among them Harper's and World's Work, we stuck to our specifications. Eesults: We received many times the largest volume of inquiries we had received in any one previous year and they came in over a longer period. Our direct sales to consumers in towns where we had no dealer distribution showed four thousand per cent, increase. (Underwear.) Our records of mail orders received show that the magazines running their advertisements next to reading matter produced mail orders at half the cost of the standard magazines. This was not only so in one case, but out of the three or four magazines we used running ads next to reading it held out in every case against about five different standard magazines we used. The following extracts are from the fifty-four letters of advertisers expressing the opinion that space in the segregated advertising sections of magazines is superior to the space next to reading matter : Personally, I lean to the idea that advertising should all be placed in one section of the magazine, as when a man is reading a s'tory, he is not interested in advertising. I myself pick up a magazine and look over the advertisements with as much interest as I take in the reading matter, but I do not like it all mixed in together. (Furniture.) From my own personal standpoint, would state in my opinion, advertising is more effective when placed in the proper part of a paper or magazine, and not next to reading matter, for people who are reading are not looking for advertising matter, and persons looking for ads are not looking for reading matter. Personally I have lost faith in advertising next to reading matter to quite an extent, especially where the advertisements appear alongside of the stories continued from forward part of magazine, for the reason that one is most generally too interested in the story to stop to look or even notice the ads. The following extracts are from the one hundred and thirty-one letters of advertisers expressing the opinion that space next to reading matter is more valuable than space in segregated advertising sections : My opinion is that advertising is always very much more effective Avhen placed next to reading matter, and that its efficiency is very much decreased by its being in the middle of an advertising section of many pages. (Steel.) Sorry to have to advise you that I have no definite evidence to submit in this connection although I have a very definite opinion to the effect that an advertisement is much more valuable when next to reading matter than when buried in the back pages in a magazine. (Trunks.) nor decided opinions : It has been our policy in the class of publications such as Country Life, House Beautiful, etc., to place our copy in the advertising section, inasmuch as it is our belief that the readers of this class of publications quite frequently gather their information from the advertising pages. On the other hand, in tlie popular women's publications, like the Ladies' Home Journal and Woman's Home Companion, we prefer space alongside of the reading matter. Perhaps this is due to the diversity of advertising matter in such popular publications, and because a large number of readers are not interested in one 'particular line, as are the readers of such publications as Country Life. This practice of ours is based entirely upon our o^vn impressions and advertising counsel, and not upon data. (Chinaware.) To your circular letter dated August 23d, we do not know of any evidence that advertising next to reading matter is of greater value to the advertiser than the advertising space massed at the two ends of the magazine. Nor have we any facts to show the contrary to be true. It is our opinion that the matter of location does not affect the power of the advertisement to influence the reader. It is all in the ad and the medium. (Underwear.) The following are extracts from the twelve letters from agencies possessing facts indicating that space in the segregated advertising sections of magazines is more valuable than space next to reading matter : From our experience, particularly with keyed mail-order copy, we would say that advertising space massed at the two ends of a magazine is of greater value to the advertiser than advertising distributed through the reading pages. The publications which use the former arrangement generally pay better for us. This may be due, however, to the intrinsic value of the mediums rather than to the position of the advertising. It seems to us that the points you mention in your letter of August 23d could best be cleared up by taking the experience of manufacturers who expect direct results from their advertising, such as mail-order houses. number of propositions happens to be standard size. In a textile account which received about one hundred thousand replies per year on an advertising expenditure of fifteen or twenty thousand dollars, a standard magazine — with advertising at the front and back of the book and not next to reading matter — brought returns direct at a lower cost than any of the next-to-reading-matter magazines. All the magazines were cut off that did not bring replies at less than 20c. each. The goods were intended for women. The various women's publications brought returns at from 14c. to 18c. each. The standard size women's publications brought returns at about 13c. Looking over records of returns covering several years, a sporting-goods account has always had its lowest-cost returns from a standard-shape publication. For several years a toilet-goods manufacturer has gotten his lowest returns from general magazines, from two magazines of standard size. The next-to-reading-matter magazines have not been able to overtake these two publications in the pro rata low cost of direct replies. A manufacturer of supplies used by business houses to handle the details of their business got his lowest cost of replies from a standard-size magazine with the advertising not running next nor opposite reading matter. The second and third magazines were standard-size magazines in the low cost of direct replies. The following extracts are from the twenty-seven letters from agencies presenting facts to prove that space next to reading matter is superior to space in the segregated advertising sections : In a number of our advertising campaigns where the results are carefully tabulated I have found repeatedly that the magazines, when placed in the order of their showing in results, give strong evidence in favor of those which place advertisements next to reading matter. The magazines in the front of the list are nearly all of this character, whereas those that bulk the advertising in the back of the book without reading matter almost always fall to the bottom of the list. On several mail order lists we have in this office, we have found, over a number of years' test, that most all of the publications that do the best are those which carry advertising next to reading matter. The evidence we have to offer that advertising next to reading is of greater value than if massed in the front or back of the magazine, is that our mail-order advertising accounts actually produce a lower cost of inquiry and of sale in publications where position is given next to reading; this where rate for quantity of circulation is proportionately the same. A canvass of lists used for three or four years back shows that on mailorder accounts approximately ninety per cent, of the papers were those where advertising was given position alongside reading and ten per cent, where advertising was bulked in the front or back of the magazine. The following extracts are from the nine letters from agencies expressing the opinion that space in the segregated advertising sections is superior to space next to reading matter : Our belief is that people have becpme accustomed to reading advertisements from force of habit, and not by accident. And an advertisement placed alongside of reading matter that might attract attention would either detract from the article being written, or might be forgotten after the story is finished, and the reader would not take the trouble to go back and locate the advertisement. When a reader opens a magazine and starts reading the advertising section, his mind is in a receptive mood for the opportunities offered, and the advertisement, we believe, is much more effective as a result of this. I have your interesting letter of August 23d, and regret to say I can throw no definite information on the point you raise, as I have never been able to check up the pulling quality of advertising next to reading matter. My opinion, and it is only an opinion, is that it does not matter where the advertisement is. Personally, I would rather have it away from reading matter, if it is so set up, or in such a position as to attract the attention of the reader. I am further of the opinion that when the mind is engaged in following the thought conveyed by the type pages, the force of the advertising appeal is weakened when it is next to reading matter, for the mind is diverted from the idea of the letterpress to the foreign idea of the advertisement. The segregation of advertisements, as in the magazines, has become a tradition. People know where to find the printed appeal to buy, Buy, Buy; and prepare an elastic mind ready to absorb. Folks examine an advertising section of a magazine as they would look for the title-page of a book or the index thereof. The following extracts are from the fifty-four letters from agencies expressing the opinion that space next to reading matter is more valuable than space in the segregated advertising sections. Everything after all comes back to a matter of opinion. I have worked with advertisers for twenty years, and I have found that, without exception, all advertisers have a predilection for position next to reading and for other preferred positions such as back cover, first page facing reading, or top of column next reading in newspapers. Whether this is a tradition handed down, or whether it is a hunch based upon some actual scientific facts, I do not know. My own personal opinion is that an advertisement next to reading is enhanced, not so much by the interest of the reader in the reading matter, but by the display given to contrast between the advertisement and the uniform gray of straight matter. stinctive feeling is that in the majority of cases this is true. In reply to your recent letter addressed to a member of our staff on the question, whether advertisements placed in magazines next to reading matter enjoy preferred position, that is, are more valuable to advertisers viewed from the point of results, we wish on the strength of experience of years, to answer affirmatively. Such positions are undoubtedly preferable to those of ads massed at the two ends of a magazine. We ourselves have not collected data on this subject, but from cases where we had occasion to learn of advertisers' experience, we have found that ads with preferred position have always brought not only better results, but were of immediate action. Logically this stands to reason, for magazines are not bought primarily for the advertising they contain, but for the reading matter they contain. The reader's first attention goes to the articles, essays and stories, and then if he is not tired out, he begins to look to the ads. If, hoAvever, an ad is next to reading matter, it attracts the reader's attention at once. It actually forces itself upon the reader. The following extracts are from the ninety-nine letters from advertisers who present neither facts nor opinions as evidence for either side of the controversy. I have no evidence that advertising next to reading matter is of greater value to the advertiser than advertising space massed at the two ends of the magazines. The tendency of standard magazines to alter their forms so as to place more advertisements next to reading, seems to point to the fact that it is easier to sell space next to reading matter than it is among solid advertising. We have no facts to present with regard to the general problem because any conclusions we have reached in this regard have proven themselves to be fallacious in some way. conditions there is a clear difference in the value of space in segregated advertising sections and space next to reading matter. For schools, books, railroads, resorts, and investments, space in segregated sections is more valuable than space next to reading matter. Space next to reading matter is more valuable than space in the segregated advertising sections for advertisements of silk if the advertisement, is placed next to an article on dresses or internal household decorations ; for advertisements of seeds if placed next to an article on gardening ; for advertisements of almost any class of goods if placed next to an article dealing with the use of the goods advertised. Second: Space in some standard magazines is more valuable than space in certain flat magazines for almost any class of goods ; but space in some flat magazines is more valuable than space in certain standard magazines for almost any class of advertising. Third: The conflicting evidence in the data and in the opinions presented by the experts, and the absence of conviction on the part of so many of them, make it evident that segregated vs. next to reading matter is not the controlling factor in value of advertising space. The quantity and quality of the circulation, the responsiveness developed in the readers, and other contributing factors, must be considered in each instance before any definite conclusion can be reached as to the value of advertising space in any particular magazine. PSYCHOLOGICAL EXPEEIMENT The introduction of the experimental method is a modern innovation in the case of all the sciences. Occasional experiments had been made in each of the sciences before experimental laboratories were established, but with the founding of laboratories for experimental purposes, physics, chemistry, geology, physiology, and botany became established on a new and firmer basis. Occasional and haphazard experiments had been made in psychology ever since the days of Aristotle, but. no systematic attempt had been made to apply experimental methods to psychology till 1880. At this date Professor Wundt, of Leipzig, established the first psychological laboratory. Since that date similar laboratories have been established in all the leading universities of the world. To avoid error as to the conception of the function of a psychological laboratory, it should be held firmly in mind that psychological laboratories have nothing to do with telepathy, spiritism, clairvoyance, animal magnetism, mesmerism, fortune-telling, crystal-gazing, palmistry, astrology, witchcraft, or with any other of the relics of the cults of medieval superstition. It is true' that the question of occult thought transference in its various forms has been put to the test in a few of the laboratories, but as none of these superstitions have been able to stand the test they have been discarded as worthless hypotheses. Quite extensive and elaborate tests have been made with telepathy, but as the results secured were so meager, it is safe to say that there is not a director of any psychological laboratory in Germany or America ( most of the laboratories are in these two countries) who has any faith in it. In frequent association with the cults mentioned above are certain other phenomena which have proven themselves to be worthy of consideration and which do occupy a place in a laboratory. Among such phenomena are hypnotism and what might be classed as prodigies or ^'freaks." To-day no one doubts the existence of hypnotism, but it is understood as something so different from what it was formerly supposed to be that it is robbed of its mysterious and uncanny connections. A mathematical prodigy is not regarded as an individual who holds relationship with an evil spirit, but as a person abnormally developed in a particular direction. Hypnotism and prodigies play such a subordinate part in the workings of a laboratory that it would not be worth while to mention them at all if it were not for the fact that they are so frequently associated with the theories which were mentioned above and which can show no good reason for their existence. Psychological experiments are most frequently carried on in laboratories especially constructed for this purpose. The laboratory for some experiments may be merely a convenient place for meeting and a place free from undesirable disturbances, or it may be rooms fitted up with the most elaborate sort of instruments needed. In experiments in which the element of time enters, instruments are employed which record one one-thousandth of a second with the greatest accuracy. The nature of the experiment determines the kind of apparatus needed, the number of persons who should take part, the method to be pursued, and the place to be chosen. Great ingenuity has been shown in constructing apparatus, devising methods, and controlling the conditions of experiments. The experiment may be simple and call for almost no equipment, or it may be intricate and call for years of investigation and an enormous expenditure of money to create the necessary conditions for its successful investigation. In general a psychological experiment is a psychological observation made under "standard conditions." Standard conditions are those which may be repeated and that are of such a nature that the various conditions are under the control of the experimenter. This makes it possible for one investigator to perform an experiment and to have his work verified by others or to show wherein the first experimenter has erred. Standard conditions are ordinarily of such a nature that they may be varied, that non-essential and confusing conditions may be eliminated, the various causes investigated one by one, and the real causes given and the object of the experiment explained. The nature of a psychological experiment (the kinds of problems that may be attacked, the method of investigation, the kind of results secured, and the treatment of the result) can be understood better by giving a concrete example than by any complete description. The following example is given because it is one that is of special significance to the readers of these pages and because it is so simple that it can be fully described in few words. style of type that the white space made the type stand out plainer and that it could be read more easily. The advocates of the heavy-face type argued that that style of type looked larger, that it used more ink, and that the figures could therefore be more easily read. It was im^ possible to decide which was the more legible without putting them to an authoritative test. For this purpose specimens of both styles were sent to the psychological laboratory of the Northwestern University, with the request that each style be tested as to its relative legibility. The method adopted was to have pages taken from the time-table set up in both styles of type. A number of persons were then requested to read the pages as fast as possible. The manner of reading was the same as that ordinarily employed by the traveling public with the exception that the reading was done aloud and that the entire page was read instead of a part of it. I conducted all experiments, was provided with duplicate sheets, recorded all errors, and took the exact time of reading with a stop watch. Two full pages were taken from the time-table and each page was set up in both styles of type, thus making four sheets, of which two were set up with small-face type and two with large. Each sheet was marked with a letter, and the four sheets are indicated as Exhibit C, Exhibit D, Exhibit E, and Exhibit F, respectively. Exhibits C and F have small-face type, as shown in Table I. Exhibits D and E have large-face type, as shown in Table II. The first four subjects are indicated by initial letters of their names, viz., R. C, N. Z., J. S., and D. W. The order in which the pages were read, the time required, and the number of errors made are indicated by the following table : Two additional persons were tested and each read over the list of stations and tried reading parts of the pages before beginning the experiment. After this preliminary drill they read the sheets as described above, but read only the first half of each sheet. The order in which the sheets were read, the time required, and the number of errors made are indicated in the following table. The persons are indicated by C. W. and E. S. respectively: Of the first four subjects R, C. is an employee in the general passenger department of the railroad for which the folder was being investigated. He was familiar with the names of the stations and was accustomed to reading this particular time-table. The first page which he read was one with the small type. The other subject who began with the small type was my brother (J. S.). He knew what the experiment was and was determined to read the page in less time than any of the others. He made very many mistakes, but read the first half of the first sheet (F) in six minutes and fifty-two seconds. None of the other four subjects even approximated such a speed or made so many mistakes — thij^ty-three. He found that he could not maintain such a speed throughout the experiment. The two of the four subjects who began with the large-face type, namely, ^. Z. and D. W., were entirely unfamiliar with the time-table and lost time in getting well under way. Under these circumstances it seems fair to regard the first page, which each of the first four read, as merely practice sheets and to eliminate them in the final results. face type. It should be added that two of the six persons complained that the small type was hard on their eyes, and three thought that tlie small-face type was much harder to read than the large-face type. The test with R. C. was made in the office of the president of the railroad concerned, and twice during the experiments R. C. was interrupted by persons calling at the door. The duplicate copy used with him was not accurate, and so the number of errors which he made in reading was not secured with certainty. With the other five persons tested no such interruptions occurred, and the number of errors made could be accurately recorded. These five were tested in quiet rooms, free from all distractions. than the figures show. The figures given above are the results secured during the last ten days. Some weeks before sheets had been secured, printed in both styles of type — a page of one time-table set up in one style of type and a different page set up in the other style. The total number of trains in the two pages were almost identical, and the names of the stations were apparently equally difficult to pronounce. So far as I could judge, the results secured with these pages were trustworthy, but to remove any possibility of doubt I had the pages prepared as described in the experiment above. The results secured in the two cases are in general the same. The experiment as described is therefore a verification of the first experiment. We thus have the results secured from twelve subjects instead of from six. The total result secured from th.e first six persons showed that the heavy type could be read 12f per cent, faster than the lighter-face type. The increase secured with the last six subjects was 13i per cent. These results are more uniform than might have been expected. Two of the twelve subjects read the small-face type faster than the large-face. As great a number of abnormal results as two out of twelve may ordinarily be expected. To overcome such errors a large number of persons should take part in the experiment and then in the general average single exceptions are less disturbing. The marked contrast in the results secured from the two kinds of faces of the same size type is found in the number of errors which the readers made, the difference being forty-five per cent, or more. The errors were ordinarily in misreading tlie time. Frequently the time was connected with the wrong station. One person, for example, read that the train leaves Cream Ridge at 7.52, when in fact the train leaves there at 7.25 and leaves Chillicothe at 7.52. . An error of that kind would cause the would-be passenger to miss his train. Mistaken pronunciation and similar minor mistakes were not recorded as errors. trains, and when it is discovered that the lighter-face type increases the chance of errors forty-five per cent, and increases the time necessary to read any part of the time-table thirteen per cent., it then becomes evident that such minor differences as that of the two faces here given are details which should be carefully considered. Those who construct time-tables try to get them up in such form that it will be easy and pleasant for the public to read them. The smaller-face type is harder to read, as is shown by the two facts of increase of time and increase of number of errors in reading it. The smallerface type is also less pleasant reading than the heavierface, as is shown by the fact that several of the persons complained that the small-face type was hard on their eyes. Time-tables are often read at night and by poor light. This fact makes it essential that the type should be of such a nature that it does not unnecessarily strain the eyes. The results of this experiment are not of more importance to the advertising manager of a railroad than they are to other advertisers who are limited to the use of type for the exploiting of what they have to offer to the public. The easier and more pleasant the type is to read, the greater are the chances that it will be read and have the desired effect. ADVERTISING The taste of foods is partially a matter of sentiment and imagination. This is largely true of all foods, but is particularly applicable to foods as served by our modern chefs. Our rural ancestors were engaged long hours of the day in strenuous toil in the open air. For them eating was merely to relieve the pangs of hunger. Pork and beans would cause their mouths to "water/' and would be a more tempting morsel to them than are the best-prepared dishes of our gastronomic artists to us. Times have changed. We have turned from a rural population living out of doors into an urban population of sedentary habits. This change is manifesting itself yearly in the alterations which are being wrought in our food consumption. The cruder, grosser, and unesthetic foods are finding fewer consumers, while those foods are finding a readier market which are more delicate in texture and more elegant and esthetic in appearance. Tlie garniture of a food is becoming a more and more important factor in its consumption. The reproduced advertisement of Sunkist ( No. 1 ) presents a good illustration of this principle. The appetite of our modern urban population is much more a matter of sentiment and imagination than was that of our rural ancestors. We all think that we prefer turkey to pork because the taste of the turkey is better than that of the pork. We should question the esthetic judgment of a man who would be so bold as to say that the taste of chicken is as good as that of quail. Even if I have such a cold in my head that I can smell nothing, I should greatly prefer maple sirup to sorghum molasses. It seems absurd that there should be any possibility of hesitation in choosing between these articles. The facts are that in each of these alternatives as to choice we are unable to distinguish the difference between the two by taste at all. The ''tasting game" has proved itself to be extremely interesting to both old and young. In this game portions of food are given to blindfolded subjects who are then asked to identify the food by eating it. In arranging for this game, the foods should be carefully prepared. The meats should be chopped fine and no seasoning or characteristic dressing of any sort should be used. If these conditions are observed, and if in no extraneous manner the name of the food is suggested, the blindfolded subjects will make the most astounding mistakes in trying to name the most ordinary articles of diet. The following are some of the mistakes which will actually occur: Strawberry sirup may be called peach sirup or sugar sirup. Beef broth may be called chicken broth. The liquid in which cabbage has been boiled may be said to be the liquid from turnips. Malt extract may be called yeast or ale. Veal broth may be called the broth of mutton, beef, or chicken. Raw potatoes chopped fine may be thought to be chopped acorns. White bread may be called whole-wheat bread. Boston brown bread may be called corn-meal cake. Beef, veal, I3ork, turkey, chicken, quail, and other meats will be confused in a most astounding manner. of taste. We are at once led to inquire for the reasons why we choose one article of food and reject another if their tastes are so similar that we cannot tell them apart when our eyes are closed or blindfolded. Why do we prefer turkey to pork? Of course there' are certain cuts of pork which do not resemble certain parts of turkey, but the question has to do only with those parts of turkey and pork which cannot be easily discriminated with closed eyes. The correct answer to the question is that we prefer turkey to pork because turkey is rarer than pork and because there is a certain atmosphere or halo thrown about turkey which is not possessed by pork. We are inclined to think of pork as ^'unclean/' gross, and unesthetic. Turkey has enveloped itself in visions of feasts and banquets. It is associated with Thanksgiving and all the pleasant scenes connected therewith. We have seen pictures in which turkey was so garnished that it looked beautiful. Grossness and sensuousness naturally attach themselves to the unesthetic process of eating and to the unesthetic articles of food, but turkey associates itself with our most pleasing thoughts and does not stand out in all its nudity as dead fowl. Again it may be asked, Why do we prefer quail to chicken? This can be answered in terms similar to those in which we explained the preference for turkey as compared with pork. Quail is rarer than chicken. Furthermore, the quail is associated in our minds with the pleasures of the chase, the open fields, pure air, the copse of woods, vigorous exercise, days spent in agreeable companionship and exhilarating sport. Our ancestors lived by the chase, and we seem to have inherited a fondness and even love for everything connected there- with. It might also be added that quail is served in a more elegant form than chicken. The garnish is a large part of a quail, but chicken is likely to be served in its nudity. There is a delicacy and yet a plumpness about the quail which is not to be found in a chicken. It will be noticed that all these points of superiority of quail over chicken are independent of taste ; yet they all have a part in determining our final judgment as to the taste of the meat. The American people have been long years in creating this sentiment in favor of the turkey and the quail, but it is well established, and it will cause turkey and quail to be desired even when other meats equally good in taste are rejected. The man who has foodstuffs to sell would be fortunate if he could get his commodity in a class with turkey and quail. Such a result would insure him constant sales at a profitable price. Just as we are willing to pay more for turkey and quail than we are for pork and chicken, so we would be willing to pay more for any article of food which could be presented to us in such an appetizing atmosphere as they are. The questions which naturally arise in the mind of the advertiser are. Can I create such a sentiment in favor of my commodity that it will be seen enshrined in sentiment? Has a glamour ever been created for an article of merchandise by advertising? This last question must certainly be answered in the affirmative. If the advertisements of Ivory Soap (No. 2) have accomplished anything, it is this very thing. All of these advertisements have been of one class for a quarter of a century. They all bring out the one point of spotless elegance. These advertisements have created an atmosphere, and when I think of Ivory Soap, a halo of spotless elegance envelops it, and I do not think of it merely as a prosaic chunk of fat and alkali. I have had this idea of spotless elegance so thoroughly associated with Ivory Soap by means of these many advertisements that I actually enjoy using Ivory Soap more than I should if the soap had not thus been advertised. The advertising of this soap not only induces me to buy I have bought it. Another advertising campaign which is to be likened to that of Ivory Soap is that of the Chickering Piano (No. 3). These advertisements, like those of Ivory Soap, often seem to say so little and at times it really seems that they squander their space by filling almost the entire page with the illustration and by saying so little directly about their merchandise. They are alike in that the goods advertised are not thrust out into the foreground of the illustration. The ChicJ^ering Piano may, indeed, be the central part of the cut, but No. 3. — This advertisement attempts to associate with the Chickering Piano an atmosphere of sumptuous elegance. other articles of furniture, etc., are emphasized in a manner which seems to detract from the piano. Many advertisements of the Chickering Piano are evidently devised to represent the piano as an article of furniture in a home which is most sumptuously and tastefully furnished. We are left to draw the conclusion foa' ourselves that if persons with such elegant homes choose the Chickering it must be good enough for us. The piano is set most artfully in this atmosphere of cultured refinement and elegance. Most pianos are advertised merely as pianos^ and I can think of them as such, but I find that my thought of the Chickering is biased by this air of elegance which hovers over it. of romance and sentiment. of Ivory Soap and Chickering Pianos is quite comparable to that which exists in favor of turkey and quail. So far as I am concerned, no advertiser of foodstuffs has quite equaled Ivory Soap and the Chickering Piano in creating a favorable sentiment or atmosphere in favor of his commodity. The firm which has come the nearest to it is the National Biscuit Company. Their adver- tisements of Nabisco (No. 4) are most excellent in that they create an atmosphere which is exactly suited to the article advertised. Delicacy and purity, even bordering on the romantic and sentimental, are the qualities which we all feel as we look at the advertisements or read them. These advertisements have been so successful with me that when I eat a Nabisco I seem "Land o CaKes" is a name frenoertly given to Scotland where meal cakei form an imporlanl artcle of diet • The phrase was rr^de famous by Robert Bums in >:«<» in his poem Oh CaptaiH ft may ell be thai some later poe» wiH sng of Amcnca as the Land of BisodI, for m the past ■five years the Amencan peooie have consijjied (fex three hundred mJIon pacJiiiges <J, phere of patriotism. to get a sentimental or romantic taste out of it. If while in the dark I were given a new flavor of Nabisco, and if I did not know what it was, it would not taste so good as it would under normal conditions. I enjoy Nabisco wafers more. because of these advertisements than I should if I had not seen them. Sentiment is not easily or quickly engendered, but if this style of advertising is continued I anticipate that Nabisco sugar appearance of a good advertisement. A soda-cracker is one of the most prosaic things imaginable, and nothing kills the flavor of an article of diet more than this feeling of the commonplace and for food. the lack of poetical or esthetic sentiment. The National Biscuit Company is undertaking a big task when it attempts to weave poetical associations about Uneeda Biscuit (No. 5). The attempts thus far have been but half-hearted and infrequent. The reproduced illustration shown herewith (No. 5) is a very good attempt to give the Uneeda Biscuit a connection with man's higher nature. If the firm is able to create a sentimental setting, or to associate the soda-cracker with something patriotic, or with something of that sort, it will add immensely to the "taste" of the commodity. There are a few advertisers of food products who are trying to create an appetizing halo and to spread it over their goods, but in geneml, food advertisements are woefully weak at this point. If my appreciation of a soap or a piano can be increased by advertising, then most assuredly there is a great field for profitable endeavor for the advertiser of foodstuffs. Nothing is influenced by sentiment and imagination more than the sense of taste. Whether I like an article of food or not often depends upon what I think of the food before I taste it. Here is the advertiser's opportunity. He is able to influence me to buy the goods, and then his ad'Vertisements may make me like the taste of the goods after I have bought them. Whether his goods will be classed with "pork" or with "turkey" depends not only on the real taste of the foodstuff, but also upon the efficacy of the advertisements in creating the favorable atmosphere. When we are pleased we are open to suggestions and are easily induced to act. When we are displeased, we become insensible to appeals, and are overcautious in our actions. One of the functions of the advertiser is to please the prospective customers and in every way possible to knit agreeable suggestions about the product offered for sale. Most persons choose their foods wholly upon the standard of taste. They choose that which tastes good while they are eating it, and refuse that which is displeasing to the palate. The savory morsel is eaten without thought as to its chemical constituents. Perhaps in no form of advertising is it so necessary to please the prospective customer as in food advertising. Pleasure stimulates the appetite, and pleasure is the standard of choice. The advertiser of food products should therefore present only the most pleasing suggestions, and he should depict his food product in the most appetizing manner possible. It is true that certain foods are bought because of their medicinal properties, but such foods should be regarded as medicine rather- than as food. The trend of our diet is not dependent upon any one thing. A careful study of the changed food fashions will discover many agencies at work, but among others will certainly be found the appearance of the foodstuff. The package, can, bag, basket, bottle, or whatever is used to encase the goods as sold and delivered, must be regarded as an integral part of the foodstuff, and as an efficient factor in determining whether the goods will be consumed in increasing or decreasing quantities. How much more appetizing are crackers packed in a box than the same crackers sold in bulk! Who will say how much is due to the form of the box in the enormous increase of crackers in America during the last few years ! Would the American public ever have taken kindly to the cereal breakfast food if we had been compelled to buy it in the bulk? The housewife purchases the provisions for the table. In her mind the package is intimately associated with the contents. She knows that a meal does not taste good unless the linen is spotless and the service more or less formal and ceremonious. The package in which the goods are delivered is as surely associated with the food as is the linen of the table and all the other articles of service. The modern housewife is insisting on a beau- tiful dining-room, the best of linen and artistically decorated china. The glassware must be cut-glass and the silver of the most improved pattern. The table must be decorated and the individual dishes garnished. The housewife who is insisting on all these details is the one the merchant should have in mind when he is planning for the sale of his goods. She wants those articles of food which come in neat packages and which can be served in neat and elegant form. In her mind the appearance is an essential part of the taste, and she does not believe that a food can be appetizing unless it looks as if it were. This same modern housewife predetermines her choice of foods by what she knows of them in advance. Her ideas may be molded by advertising, for this process is at work daily in all our homes. Like the housewives, we all form an idea of a food by the advertisements of it which we have seen, even 'if- we have not read them. If the advertisement looks pleasing and if the food is there presented in an appetizing manner, we believe that the food itself will be all right and we are prejudiced in favor of it. One thing that spoils the looks of food products is having them piled up in a confused mass. A table which contains many articles of food at once is not inviting to the epicure. We like to have our meals served in courses, and prefer many light courses rather than a few heavy ones. The same principle holds with advertisements. Many advertisements which would otherwise be strong are weakened by overcrowding of good things. The reduced advertisement of Wheatlet (No. 6) as reproduced herewith is not appetizing, for the appearance of the whole thing is ruined by the multitude of fruits which are thrown promiscuously into the illustration. I think I might like Wheatlet if it were served with any one of these frmts, but if it should be presented in such a confusion as this it would not be eaten at all. the appearance of the package. ploy in purchasing foods must be a factor in determining the appropriate form of advertising. In some instances householders make written lists of the goods desired; the order is placed without looking at the goods at all. In other instances the order is sent by telephone or by a messenger. In perhaps the most cases the purchaser enters the grocery store in person. She has her list of purchases but imperfectly made out. As she enters the store she is confronted by rows and tiers of bottles, cans, and boxes. Out of this bewildering multitude of packages she is pleased to see certain ones which are known to her. These familiar packages catch her attention more than the scores of unknown ones. The known ones are the packages which she is most likely to purchase, as they catch her attention just at the time she is trying to recall the things of which she may be in need. Of the two advertisements (Wheatlet and Egg-o-See), the last-mentioned emphasizes the appearance of the package, while the advertisement of Wheatlet omits the presentation of the package. At the moment of making the purchases for the week these two commodities might be on the shelf before the purchaser. The reproduced advertisement of Egg-o-See is such that it has made her familiar with the package as it appears on the shelves and it would thus be called to her attention at the critical moment. The advertisement of Wheatlet is not such as would have assisted in familiarizing her with the appearance of the package, and thus it does not assist in attracting her eye to the goods advertised at the moment of decision. While in the grocery store the purchaser does not taste the various articles, but tier upon tier of different goods are presented to her sense of sight. It is by sight that she recognizes the various packages, and an advertising campaign that familiarizes the housekeepers of the nation with the distinguishing appearance of any particular package has done much to increase its sale. While the public is being made familiar with the food or the food container, a pleasing appeal should also be made to the esthetic nature of the possible customers. to be reminded of the fact. We refuse to use the terms "cow-fiesh," "hog-flesh/' and ^'sheep-flesh.'' Our abhorrence of such ideas is registered in our language, and so we use the terms "beef," "pork," and "mutton." It is not pleasing to think of eating the flesh of the smaller animals and of fowls, still it is not so abhorrent as the thought of eating the flesh of the larger and domestic animals. Accordingly we still use the same word to denote the live animal and the flesh in such instances as "rabbit," "squirrel," "chicken," "goose," etc. It is quite conceivable that the sight of a dead carcass would whet the appetite of a hyena. The sight of an animal, whether dead or alive, is not very appetizing to the civilized man or woman. We know that beef is nothing but the flesh of dead cattle, but we refuse to entertain the idea at mealtime. Indeed, we have become so cultured that we like to have our meats garnished till they cease to have the appearance of flesh at all. There are whole nations which refuse to eat meat, and vegetarianism in our own country is but an indication of the revolt of the human mind against our carnivorous habits. As a nation our wealth is increasing rapidly and consequently we are better able to purchase meats now than fifty years ago, yet the government statistics shov a great decrease per capita in the consumption of meats. We have changed from a rural to an urban population and hence require less meat foods, and what we do eat must always be presented in a pleasing manner and in a way which jars as little as possible against our refined and cultivated natures. In advertising meats, the fact should never be emphasized that the meat is the flesh of an animal. That point should be taken for granted and passed over as lightly as possible. Thus the tract of beef. secured from the carcasses of beautiful steers. This advertisement makes no one hungry for Liebig Company's extract of beef. The advertisement is intended to make the public familiar with the Liebig trademark^ and the criticism is therefore directed against the choice of such a trademark rather than against this special advertisement, which is but a presentation of the trademark. The reproduced advertisement of Armour & Co. (No. 9) does not present an animal in its entirety, but it represents too much of it. The carcasses as shown in the advertisement are too large to tempt our appetites and the general effect is rather disgusting. If meat with the carcasses of dead animals. pleasing advertisements of meats that has appeared in our magazines. No one can look at the advertisement without being impressed with the desirability of these products. The meat is presented in small pieces and is garnished till it is hardly recognizable. Such an advertisement creates a demand for the goods and prejudices the customers in their favor, and the ham and ox tongue will taste better to the customer after he has seen this advertisement. This would be a better adver- tisement for Armour & Co. if the can were shown in which this meat had been purchased. The border might include a cut of the container and the total effect be rendered none the less artistic. nivorous but we object to having animals connected in any way with our foods. The reproduced advertisement of White Star Coffee (No. 11) is in every way disgusting. Frogs are inherently uncanny to most persons, and to see them here as the representatives of a particular brand of coffee serves but to instil a dislike and even abhorrence for the product. This advertisement never made any one eager for a cup of coffee. It does not create a demand for coffee and in the cases where the demand already exists it does not convince the casual observer that White Star Coffee is particularly desirable. It is one of the most silly and destructive adver- tisements appearing in our current magazines. The other reproduced advertisement of the same brand of coffee (No. 12) is in no way objectionable and is a great improvement in point of display over the first one. Ordinarily we feed the animals what we do not care to eat ourselves, and the assumption is that that which tising. is good enough for the beasts is not fit for men and women. In the reproduced advertisement of Korn Krisp (No. 13) the food is represented as being fed to the fowls. The assumption would be that it is a food especially adapted to their taste, and I should not want to eat it myself. Even the young goose seems to be disgorging the food for some unexplained reason! Here we have evidence of an amateur advertiser who was enamoured with his play on the words, "it fills the bill," and who was willing to pay for the exploitation of his joke under the pretense of an advertisement. It may be possible that under very exceptional circumstances it would be advisable to introduce an animal in an advertisement of a food product, but it should be don^ only with great caution and with full realization of the dangers incurred because of the inevitable association between the animal and the food advertised. The advertiser must seek to associate his food only with purity and elegance. In a sense the advertisement is the representative of the food, and if the advertisement is associated with disgusting or displeasing objects the food is the loser thereby. The advertising pages of many of our cheaper periodicals are nothing better than chambers of horrors. The afflictions of mankind are here depicted in an exaggerated form. The paper is poor, the ink is the cheapest, and the make-up is without taste. They are altogether a gruesome sight. Food advertisements in such papers are practically worthless. Even in these papers a few food advertisements are found, but, unfortunately, there are only a few. In these cheaper forms of publications the majority of advertisements are likely to be of patent medicines or of forms of investments. The medicines are advertised by depicting the unwholesome aspects of life, and the investments are usually of a questionable sort. These advertisements of patent medicines and investment schemes make the readers suspicious and hence they ar-e in a condition of mind which leads them to suspect the foods advertised as being adulterated and impure. American dailies. The food advertisements are here associated with "skin diseases/' "asthma/' "consumption/' "blood poison/' "whirling spray douche/' "pimples/' "eruptions/' "backaches/' and other ills and un- appetizing suggestions. What value is the advertisement of Malt Marrow and of Armour's Star Ham in such an environment? Until the daily papers have more to offer than such position as is indicated by No. 14 they certainly are not preferred media for food advertisers. THE LAWS OF PROaEESSIVE THINKING In acquiring simple acts of skill we all use in the main the ^'trj, try again'' method. This is technically known as the ^^trial and error" method. We simply keep trying till we happen to hit it right, and then w^e imitate our successes till finally the skill is acquired. The first correct response may have been reflex, instinctive, or merely accidental. When, however, w^e attempt to develop acts of skill or ideas in advance of our fellows this simple method of trial and error does not suffice. It is of course true that most of the actions of all of us and all the acts of many of us are not progressive in the sense here intended. By progressive thinking we mean the conception of new ideas, the invention of new methods of doing work, the construction of a new policy or a new instrument, or something of a kindred nature. For such thinking the essential mental process involves nothing totally different from ordinary thinking, but it involves the ordinary processes in a more complete and efficient form. The processes referred to are the following four : observation, classification, inference and application. The laws of progressive thinking are derived from these processes and are nothing more than a demand for the complete carrying out of these four processes. The thinking of the advertiser does not differ from that of others; and in what follows the discussion will be confined to the advertiser and his problems, inasmuch as such a concrete problem seems more definite than a general discussion. ers have eyes, but they do not all use them equally well. Observation should begin at home. The advertiser should analyze his own response to advertisements, but unfortunately he is likely to become so prejudiced or hardened to advertisements that his own judgment must be taken with great caution. How does this advertisement or this part of the advertisement affect me? How does it affect my wife, my mother, my sister? How does it affect the persons who ride on the train with me or who pass by the billboards with me? This is the territory which is so near at home that we disregard it. Such observations must, of course, be supplemented by tests carried on by means of keying the advertisement, by consulting the sales department, etc. None of us are ideal observers. We can't tell just how certain advertisements affect us or what element of the advertisement is the most effective. We do not observe accurately how advertisements affect those about us. We see only those things which we have learned to see or which have been pointed out to us. We are not skillful in discovering new methods of securing new data and so our observations are neither so accurate nor so extensive as they should be. The advertiser has an extensive field of observation and but little direction as to the best method. He must observe his goods in order to know the possible qualities which may be presented with greatest force. He must observe the public to which he is to make his appeal. He must be a practical psychologist. He must also be an advertising expert according to the narrow and fallacious use of that term. In the past the advertiser has not been required to know his commodity or his public, but he has felt satisfied if he was an expert in the construction of advertisements, the choice of mediums, the keying of advertisements, and similar strictly technical accomplishments. The observations are not complete unless they include these three fields, i.e.^ the goods, the public, and the advertisements. The second step in the method, logically speaking, is that of classification. The observations must be classified. The scattered data must be brought together before they can be utilized. Great skill is necessary to make the right classifications. In any large office care must be used in filing away material to see that the general heads are not only correct but that they are the most usable ones. Likewise in filing away our observations, in getting them into shape so that we can use them, the greatest care is necessary in choosing the right heads and in getting all the data under their appropriate general heads. All the data must be analyzed and classified and reclassified, for new observations require new classifications, so that the classification is never complete and the generalizations based on the classifications are continually increasing. For instance, every advertiser has a certain amount of data concerning the effectiveness of advertisements without illustrations in publications in which the text matter is largely illustrated. But how many advertisers have grouped this data and formed any general statement concerning it? The process of classification involves that of analysis, and the difficulty of forming new analyses is much greater than would be supposed by those who have not studied the process. In order that new classifications may be made, the data must be worked over and thought of in all the possible relations. The man who makes the best use of his knowledge is the one who has it best analyzed and classified. Advertisers have sent me two different advertisements which were carefully keyed, one of which was successful and the other one unsuccessful. In some cases the advertisements are very similar and the differences at first sight seem non-essential, yet the differences are great enough to secure success in one case and failure in another. Lender some circumstances it might be practically impossible to deduce the cause of the differences. Recently an advertiser sent me two such advertisements. One had been unsuccessful and the other had been extremely successful. The illustrations were very similar and the arguments were largely identical throughout. The two had been run in the same sizes and in the same and also in different publications. It seemed quite evident that the difference must lie in the advertisements themselves and not in any extraneous matter. I think that I was correct in inferring that the difference lay in the display of the illustration and text matter, but not in the quality of either of them. In the unsuccessful advertisement there was no restingplace for the eye and no point or line of orientation. (The line of orientation is the line which the eye follows in observing an illustration.) In the successful advertisement the eye rested naturally at the point from which the advertisement looked the most artistic and from which the content of the advertisement could best be understood. Furthermore, the line of orientation was such that the eye naturally followed the order which made the argument and display mutually strengthening, and so the eye rested, at the conclusion, at the point which was most inducive to immediate action. Any trained artist, or even any one who had studied the theory which underlies artistic productions, might very naturally have looked for this resting-place for the eye or for the appropriate place for the line of orientation, but unless these features were taken into consideration the wrong conclusion would have been drawn as to the cause of success or failure in the case of these two advertisements. The fourth step in the mental process of the progressive advertiser is that of applying the deductions drawn from the former experience. The laws concerning the force called electricity are known to thousands, but it takes an Edison or a Marconi to make a new application of these same laws. If Edison and Marconi had not a comprehensive grasp of these laws they would not be inventors. Others have as good a knowledge of all the phenomena connected with electricity as they and yet are unable to make a practical use of their knowledge. Science can formulate the laws of the phenomena as far as they have been discovered and applied, but it cannot lay down rules or suggest infallible methods for further discoveries and inventions. This does not minimize the value of science, but it emphasizes the need of originality and ingenuity in the man who strives to lead his profession and to invent new methods and to make new applications of those he has learned. Certain keen students of advertising have prophesied but little benefit to advertising from the science of psychology, because a science cannot lay down rules for things which are not yet discovered. This criticism has weight with any who should be so foolish as to suppose that every accomplished student of the human mind would of necessity be a successful advertiser. To suppose that a great psychologist would of necessity be a successful innovator in advertising is just as sane as to suppose that every one who understands electricity as well as Edison would have as great a record as he at the patent office. If Edison had known nothing of the science of physics, it is quite certain that he never would have been heard from. Science does not produce inventors, but it is of great assistance to a genius and may cause him to become a great discoverer. Psychology is of assistance to every advertiser in helping him to observe widely and accurately, in teaching him how to classify or group his observations systematically : it should help him in drawing the correct conclusions from his classified experience. If psychology could do no more it would be of inestimable value, but as applications or new discoveries depend so largely on the formation of correct deductions and hypotheses, psychology may even be of benefit in this last and most difficult step in the mental process of the innovator. The most successful advertisers are those who observe most widely and accurately, who classify their observations and group them in the most usable form, who then think most keenly about these classified observations so as to draw the most helpful conclusions, and lastly who have the greatest ability in utilizing these deductions in their advertising campaigns. They are the active men, those who are seeking better methods of observation and of classification and who are never content with their past deductions or their applications. To show what I mean at this point I will illustrate from methods employed by one of the leading advertisers of America. In observing the effect which advertisements produce upon a community it is much easier to learn which advertisements are effective than what it is in the particular advertisements which makes them interesting. Mr. B., as an aid in making observations at this latter point, secured several thousands of letters from readers of issues of the magazine of which he was the advertising manager. In these letters the writers told which advertisements they were the most interested in and what it was in each particular advertisement which interested them. Mr. B. could have turned to the pages of his magazine and have made a personal observation as to the way the different advertisements affected him and what it was in any particular advertisement which interested him most, but by the method described he multiplied his observations a thousand fold, and all within the commodity with which he has to deal. When he had read over the letters he had the data before him but it was in chaotic and worthless condition. The next step was to bring order out of chaos. It was easy to tabulate the results and find out how many were especially interested in each particular advertisement. But when it came to classifying the reasons — and often women's reasons at that — for being interested in each advertisement, the task proved itself to be one of great difficulty. The data were turned over to me for such classification, and though this is not the place to give in full the general heads and the sub-heads under which the classification was finally made, it may be interesting to know that t4ie reasons for advertisements proving interesting were in the order of their frequency: first, reliability; second, financial consideration; third, the construction of the advertisement ; and fourth, the present need of the reader. Thus of the letters received one month, 607 affirmed that they were most interested in their chosen advertisement because they believed that the firm or the medium or the goods were strictly reliable. In some cases they had tried the goods adver- tised ; in some they had dealt with the firm ; in some they noticed the testimonials or the prizes taken, etc. In the same month 508 were particularly interested because of money considerations. Some because they could get the goods advertised more cheaply than elsewhere; some because the advertisements offered a chance to get something for service instead of for cash, etc., etc. In the same month 418 were most interested in the construction of the advertisement. Some were most interested, for instance, in the Nestle's Food advertisement, because it was very artistic and was run in colors. In the same month 408 were most interested in a particular advertisement because it presented goods which they needed at that particular time. To recapitulate the results : 607 for reliability, 508 for money considerations, 418 for the construction of the advertisement, and 408 because of the present need. It is not necessary to say that from the classifications of these data certain conclusions have been drawn and that attempts are being made to apply the conclusions to the planning of advertising campaigns. These experimental applications will furnish new data; these will in turn be classified, new conclusions deduced, and further attempts at practical application will follow. In this way we have an endless chain of observation, classification, inference, and application. This method is applicable not only to writing advertisements but to every detail of the profession. Indeed it is the method of progressive thinking in every line of human endeavor. The four steps are not fully differentiated in our actual experience, but are presented here as distinct for the sake of clearness. STEEET EAILWAY ADYEKTISING Every form of advertising has its particular psychological effect, and the medium which the merchant should choose depends upon many conditions. Foremost among such conditions are expense, the class of persons to be reached, the quality of goods to be presented, the width of distribution of goods, etc., etc. Equal with these conditions, however, the advertiser should consider the peculiar psychological effect of each particular form. The monthly magazine, the weeklies and the dailies carry authority which is lacking in other forms. These publications are held in high repute in the household, and advertisements appearing in them are benefited by this confidence which is bestowed upon everything appearing in them. Posters, bill-boards, painted signs, and similar forms of advertising admit of extensive display within a prescribed area and have great attention value. Booklets, circulars, and similar forms of advertising admit of complete descriptions and may be put in the hands of only those who are interested in the commodity offered for sale. They appeal to the reason in a way not surpassed by any form of printed advertising. The psychological effect of street-car advertising is not generally recognized, and in this presentation there is no attempt to praise one form of advertising and to decry all others, but inasmuch as the psychological effects of other forms are recognized and that of streetcar advertising is frequently not recognized, this latter is selected for fuller presentation. Our minds are constantly subjected to influences of which we have no knowledge. We are led to form opinions and judgments by influences which we should reject if we were aware of them. After we have decided upon a certain line of action, we frequently attempt to justify ourselves in our own eyes, and so we discover certain logical reasons for our actions and assume them to have been the true cause, when in reality they had nothing to do with it. The importance of these undiscovered causes in our every-day thinking and acting may be illustrated by the following example. Lines A and B are of equal length, although A seems longer. Now why do we reach the conclusion that A is longer than B, when in reality such is not the case? If they are the same length, and we see them in a clear light, we should expect that they would appear to be as they actually are. The accepted explanation of this illusion is that there are, entering into the judgment, certain imperceptible causes which make us see the lines as of different length. This explanation was not discov- ered till recent years, but it has been proved to be correct. In judging the length of lines we run our eyes over them, and so get a sensation from the contraction of the muscles of the eyes. We judge of the length of lines by the amount of this sensation derived from contracting the muscles which move the eyes. If two lines are the same distance from us and are the same length, our eyes w^ill ordinarily move equal distances in traversing their lengths. If two lines are equally distant from us, and one longer than the other, we ordinarily have to move our eyes farther in estimating the length of the longer one than in estimating the length of the shorter one. We are not aware of the sensations received from these movements of our eyes, and yet we estimate lengths of lines by them. The peculiar construction of the lines A and B induces the eye to move farther in estimating the length of A. We therefore assume that A is longer than B because our eyes move farther in estimating its length than in estimating the length of B. The street-railway advertiser controls an unrecognized force which is similar to that just described in the estimation of the length of lines. The arrow pointing toward the line as shown in A causes us all to overestimate the magnitude of the line ; and there is a factor present in street-railway advertising which causes us to be influenced by it more than would seem possible. There has been much poor street-railway advertising, and yet the results have been phenomenally great. Some recent tests of the extent to which passengers had been influenced by such advertising showed most conclusively that there was an unrecognized power in it. A study of the situation discloses the fact that this unconscious influence is none other than TIME which manifests itself in three phases as presented below. As a result of investigations upon magazine and newspaper advertising the conclusion was reached that on the average only ten per cent, of the time devoted to newspapers and magazines was spent in looking at the advertisements. .( For a fuller account of the investigation see Chapter XXIX. ) As a conclusion deduced from these results it was recommended that advertisements should be so constructed that the gist of each could be comprehended at a glance, for most advertisements in newspapers and magazines receive no more than a glance from the average reader. The ordinary reader of newspapers and magazines glances at all of the advertising pages and sees all the larger and more striking advertisements. There are many exceptions to this. There are persons who read all the advertisements and there are others who glance at but few of them. Magazines and newspapers have become so numerous and the daily duties so pressing that we cannot take time to read al] the advertisements, and so we devote but few minutes to them, and in those few minutes we see a great number. We cannot afford the time to do more. * The case is different with street-railway advertising. Here there is no shortage of time. There is sufficient opportunity to see every person in the car and to devote as much time to the process as good breeding will allow. Thereafter one is compelled to look at the floor or else above the heads of the passengers. One cannot read a newspaper on a crowded car — I am acquainted only with crowded cars. Neither is it practicable to read a book or magazine on a jolting car — I am acquainted only with such. In defence of one's good breeding and to drive away the weariness of the ride many a passenger is compelled to turn his gaze on the placards which adorn the sides of the car. The passenger has for once an abundance of time. He reads the card and then reads it again because he has nothing else to do. This may be very silly, but what of it? It offers a diversion, and anything is better than looking at the floor, counting the number of passengers, or watching the conductor ring up the fares. America is far beyond the conception of most persons. The electric railways of the United States carry about fourteen billion, five hundred million passengers annually. This does not include the electric divisions of certain steam roads which carry advertising. All cars carrying advertising in the United States carry about fifteen billion riders annually. The population of the United States living in towns on or adjacent to electric railway systems is about fortyfive million people. The percentage of passengers carried daily to the total population of these cities averages approximately one hundred per cent. There are no data available for the length of time consumed by an average street-car ride. Fifteen minutes may be regarded as a fair estimate. Upon this estimate each inhabitant of our cities spends on the average about fifteen minutes a day in a street car. These rides become very monotonous ; the passengers' minds are not occupied, and very much more time is whiled away by looking at the advertisements than we are aware of. One young lady asserted that she had never looked at any of the cards in the cars in which she had been riding for years. When questioned further, it appeared that she knew by heart almost every advertisement appearing on the line (Chicago and Evanston line), and that the goods advertised had won her highest esteem. She was not aware of the fact that she had been studying the advertisements, and flatly resented the suggestion that she had been influenced by them. Some of the goods advertised were known to her only by these advertisements, yet she supposed that they had nothing to do with her esteem of the goods. She supposed that she had always known them, that they were used in her home, or that they had been recommended to her. She did not remember when she had first heard of them. It has been said that we have learned nothing per* fectly until we have forgotten how we learned it. This has a special application to advertising. An advertisement has not accomplished its mission till it has instructed the possible customer concerning the goods and then has caused him to forget where he received his instruction. This is especially important in street-car advertising. The information which we receive from the card in the street car soon becomes a part of us, and we forget where we received it. This forgetfulness of the source of our information is due to the interval which has elapsed between the first time the advertisement was seen and the present. The more frequently the advertisement is seen, the more rapidly will the memory of the first appearance fade and leave us with the feeling that we have always known the goods advertised, and that the advertisement itself is no essential part of our information. [This point is more fully developed in Chapter XIV, Suggestion.] The element of time as it enters the problem of advertising is recognized to a limited extent in the two phases thus far discussed, but there is another phase and one of even more importance which has., to the writer's knowledge, never been mentioned in connection with advertising. We devote the most time to those subjects which we regard as the most important. My profession takes most of my thought, the lacing of my shoes very little. Ideas which impress me as important cause me to think of them for lengthy periods of time. Ideas which seem insignificant are dismissed immediately from my mind. This element is recognized by every skillful public speaker. He speaks rapidly that which he wishes us to consider as of little importance. He speaks slowly that which he wishes us to regard as of special significance. We weigh the importance of his statements and estimate their value in terms of the time which he gives to each. In poetry, thoughts which are trivial or of minor importance are expressed by rapid movements. Ideas which are of more importance and which are suppbsed to call forth much thought from the reader are expressed in slow movements. This same principle holds in music. Music which means much — which suggests many thoughts, which is sublime, deep, or large — all such music is written in slow time. The so-called "rag-time" is assumed to have no meaning; it is not supposed to suggest lines of thought. It has no intrinsic importance and is consequently appropriately expressed in fast time. In the case of the orator, the poet, and the musician the effect is produced by this unrecognized element of time. That which holds our thought for a longer time seems to us to be important; that which we hurry over seems unimportant. The orator, the poet, and the musician have simply accommodated themselves to our intuitive method of thinking and have been successful because method of thought. As was shown above, the passengers on street railways have but little to distract their attention. They go over the same road so frequently that the streets passed through cease to be interesting. Since newspapers and magazines cannot be easily read, the cards have but few rivals for attention. Even those who have but little interest in the advertisements find that they glance at the cards frequently and that the eyes rest on a single card for a considerable length of time. The same card may be read or glanced at daily for as long a time as the card is left in the car. The sum total of the time thus devoted to the card is as great as the amount of time that we devote to many of our important interests. Under ordinary circumstances we bestow thought upon objects in proportion to their importance. This is not an absolute rule, of course, but it expresses a principle. The reverse of this principle is not recognized by us at all and yet it is of primal importance. That which occupies our minds for a great amount of time assumes thereby an importance which may be out of all proportion to its real value. Illustrations of this fact are to be found on every hand. The mother is likely to think the most of the child which has caused her the most thought. The sickly child occupies her mind more than the well one, and this accounts for the fact that she attributes to the sickly child an importance far beyond its real worth. Our old schoolbooks, upon which we were compelled to bestow so many hours of study, in later years assume a value in our eyes far in excess of their real merit. The goods which through their advertisements have occupied our minds for long periods of time assume in our minds an importance which is often far in excess of anything which would have been anticipated by one who was not familiar with the peculiar power here described. In estimating the relative values of two competing lines of goods, I assume that my judgment is based on the goods themselves as they are presented to my reason. I am not aware of the fact that I am prejudiced in favor of the goods that have occupied my mind the longest periods of time. Yet it is as certain that this element of time has biased my judgment of the relative values of the goods as it is that the eye movement influences my judgment of the lengths of lines. Advertisements in newspapers and magazines are seen by a great number of the readers, but the time devoted to any particular advertisement is very small, unless there is a special interest in the advertisement. There is indeed no form of advertising which is presented to such a large number of possible purchasers for such a long period of time and so frequently as is the advertising in street-railway cars. In most other forms of advertising we devote to any particular advertisement only as much time as we think it is worth. In streetrailway advertising we devote longer time than we really think is due to the advertisements, and then we turn around and estimate the value of the goods advertised by the amount of time that we have devotied to the advertisement. This is the psychological explanation of the amazing potency of this particular form of advertising. ILLUSTRATED BY AN INVESTIGATION UPON NEWSPAPERS Experience is the best teacher. Methods that enable one to make the greatest use of one's own experience are valuable. Methods that make the experiences of others also available are even more valuable. One of the functions of every science is to develop methods that are useful for investigating problems which concern that particular science. One of the methods that modern psychology has developed is the so-called Questionnaire Method. This method has many defects, but it has the inestimable value of assisting the investigator to take advantage of the experiences of a great number of individuals. The Questionnaire Method is used to secure the consensus and the diversity of many individual opinions. A single question or a set of questions is presented to any desired group of persons. The answers to the questions are derived from the experiences of those who are to answer them. If the questions call for the description of simple unemotional events, reliance may be put in the answers received from all sincere respondents. If the answers call for a difficult analysis of motives and interests, less reliance can be placed in any single answer and greater caution must be used in drawing conclusions based upon the replies. available. A single illustration will indicate how such questions arise, how they may be investigated, and will also present a mass of information concerning newspapers that is of interest and profit to advertisers. A prominent advertising man was planning copy to be used on street-car cards designed to secure new subscribers to newspapers. The campaign was to be conducted in different American cities in the interest of local papers, but in each case the attempt was to be made to reach the best citizens of the city. The two following questions naturally suggested themselves: What is there in the modern newspaper that appeals to the better classes of society ^ and what motives should he appealed to in inducing them to begin a subscription? The problems here raised are clearly psychological and subject to the Questionnaire Method, which was employed in investigating them. A carefully selected list was prepared containing the names of four thousand of the most prominent business and professional men in Chicago. An attempt was made to include what could fairly be said to be the best citizens of Chicago. The number was so large that it contained a fully representative group. For the purpose of comparison, another list of one thousand names was prepared. This list contained the names of men from very different classes of society, but all, with few exceptions, were adult men. The questionnaire as reproduced herewith was mailed to the five thousand names constituting the two lists. III. State in order the five features of your paper which interest you most. (For example, politics, society, finance, sporting, foreign news, local news, special articles, ro- Answers to these questions are desired from the selected persons to whom they are mailed. The answers are needed in solving a psychological question of interest and may be placed in the stamped envelope enclosed herewith and mailed at once. They will be gratefully received by the sender. Yours respectfully, Eeplies were received from about two thousand, three hundred of the representative business and professional men. The replies from the one thousand are disregarded in the present chapter ; and inasmuch as but approximately two thousand answered each of the questions, the two thousand, three hundred are hereafter referred to as "the two thousand." Those receiving the questionnaire seemed much interested in the research, and although they are very busy men, the answers indicate careful deliberation and the utmost sincerity. Al- though no place was provided for signatures, a good proportion signed their names to the paper or enclosed a personal, signed letter. A large number of the slips were carefully keyed, and even when no signature was attached, the author of the replies was known. In all the slips the key indicated at least to which one of the numerous groups the respondent belonged. In case of doubt as to whether the replies were filled out personally by the man to whom the questionnaire was sent, they were rejected as not authentic. No proxies were desired. Over fifty per cent, of those receiving the questionnaire took pains to fill out the blank. This proportion is unusually large and is to be attributed to several causes. A stamped return envelope was enclosed. The subject under investigation was personally interesting. The answers were sought for as a means of "solving a psychological question," and psychology is very popular just at present. The investigator, owing to his university connection, was assumed to be honest and desirous of securing only the facts. The advertiser might have great difflculty in selecting a group of persons whose answers would be significant and yet who would be willing to fill out the blanks. Doubtless in many cases the list would have to be confined to business associates or to personal friends. Haphazard, voluntary answers received in competition for a prize or for the gaining of a paltry reward are not to be compared in value to voluntary replies from a carefully selected list. The difficulty of securing trustworthy replies is so great that the advertiser will usually be compelled to have the investigation carried on by a disinterested person, as it was done in the present instance. QUESTIONNAIRE METHOD 379 fact should never be forgotten in estimating the results. In the questionnaire reproduced herewith, the amount of space left for answering the first question suggested that the names of but one or two papers were to be written. This doubtless affected the results. Also in connection with the third question a series of answers was suggested. The number of suggestions was made so large that no particular one would have much more effect than the others, and as all probable answers were suggested the results were certainly not greatly changed thereby. The fact that each individual reads or scans a number of papers daily was brought out clearly by the answers to the first question. ( I. What Chicago daily or dailies do you read?) Eighty-six per cent, reported themselves as reading more than a single paper. The space in the questionnaire left for writing the names of the papers read was but a little over one inch in length. In spite of this fact the respondents took pains to write in a number of papers. As stated above, it is quite probable that the inadequate space and, in some cases, the haste of writing the names caused an understatement of the actual number of papers read. As reported, the figures are as follows : attention; These subsidiary papers contain a large part of the advertisements that are also contained in the preferred papers, which command the most attention. The same advertisement seen in two or three papers may be more effective than if seen in but one; but most advertisers are convinced that.it is not worth three times as much to have an advertisement seen in three papers as it is to have it seen in one. The duplication of circulation represents a loss. If the advertiser could pick out the papers that command the most confidence of a relatively large number of readers, he could afford to neglect the subsidiary papers entirely. A decided majority seemed to consider fifteen minutes a fair estimate of the time spent in reading the daily papers. Four per cent, answered that they spent less than fifteen minutes daily. Twenty-five per cent, reported a greater amount of time. A few reported as much as two hours, but "just about fifteen minutes" was by far the most common answer. The writers were frequently careful to state that this fifteen minutes was the total time spent in reading all the papers and not the amount spent in reading each of the several papers read. Considering together the total number of papers read and the total amount of time spent in reading them, we reach the conclusion that a very decided majority of these representative business and professional men spend but approximately from five to ten minutes reading any particular paper. These few minutes admit of but the most cursory reading. A favorite program, as reported, is the reading of the head lines, the table of contents, the weather reports, etc. Then if time admits or if any- thing especially interesting is discovered, attention may be turned for a few seconds or minutes to a more leisurely reading of the articles discovered in the preliminary search. The papers are glanced through so hurriedly that an advertisement, in order to be seen at all, unless sought for, must be striking in appearance and must announce something in which the reader is particularly interested. Advertisements may be divided into two groups : classified and display advertisements. The classified are read only by those who search for them. The display advertisements are glanced at by a very large number of persons who pick up the paper. The advertisement must tell its story quickly if at all. If the message which it is capable of imparting to those who glance at it is inviting, the advertisement may be selected and read from beginning to end. The advertiser should attempt, however, to construct his advertisement so that a single glance at it may be effective in imparting information and in making an impression even though the advertisement is not to be under observation for more than a few seconds. A majority of the respondents answered the second question, naming the preferred paper. (II. Which one do you prefer?) A very respectable minority, however, confessed that they had no preference. Many answered that one paper was preferred for general news, another for cartoons, another for special articles, another for moral tone, etc. Others refused to go on record as preferring any paper and so expressed themselves by saying that one paper was "less objectionable," "less yellow," "less venal," etc., than the others. Particular groups of men displayed considerable uniformity in their preference for a single paper ; e.g., the one hundred pro- fessional men connected with one educational institution preferred one paper; the business men who were members of an athletic club showed a decided preference for another paper; the business and professional men who were members of one of the most prominent clubs preferred with equal uniformity still a different paper. The circulation of the evening papers in Chicago is greater than that of the morning papers, and it is probable that they are preferred in more cases than are the morning papers. For business and professional* men the reverse is true; among them the morning papers are read in larger numbers and are preferred in more instances than the evening papers. With these men the evening papers are often to be regarded merely as subsidiary. The laboring classes have no time to read a morning paper, but "after the day's work is over, the evening paper is read and doubtless much more than fifteen minutes is devoted to it. Many business and professional men prefer evening papers and many laboring men prefer the morning papers, but such instances are exceptions rather than the rule. A majority of business and professional men fail to see advertisements appearing in evening papers and are not greatly affected by those that they do see. Likewise, probably a majority of the laboring class are unaffected by advertisements appearing in the morning papers. If these statements did not have so many exceptions the advertiser's task would be comparatively simple when it comes to choosing a medium for any particular advertisement. If he wanted to reach the better classes, he would use the morning papers ; if he wanted to reach the laboring class, he would employ the evening papers. of a uniformity in their selection of a preferred paper, but the most surprising thing was the lack of uniformity. This particular group could not be reached by using anything less than all the papers. Perhaps one-half of them could be reached by a single paper, three-fourths by two papers, and over nine-tenths of all by using half the papers. The chief interest in the investigation centers in the answers to the third question. (III. State in order the five features of your paper which interest you most. ) To reduce the answers to some sort of a comprehensible unit, the following plan was adopted. A feature that was mentioned as first choice was credited with five points ; one mentioned as second choice, four points ; one mentioned as third choice, three points ; one mentioned as fourth choice, two points; one mentioned as fifth choice, one point. The sum of all these points was arbitrarily assumed to represent the sum total of interest. It was then found what per cent, of this total interest had been credited to politics, editorials, and all other features mentioned by any of the respondents. As thus found, the total result for all papers and all respondents is as follows : Humor 05 Inasmuch as these figures represent the distribution as found for all the papers combined, it would, of course, be anticipated that the same order would not hold exactly for any individual paper. In most particulars there is a pronounced similarity in the distribution of interest in the different papers. This is true, for in* stance, in the case of local news. In one paper it monopolizes 19.5 per cent, of the interest and in the others 18.8 per cent., 18.3 per cent, 17.6 per cent, 14.9 per cent., 13.8 per cent., 12.8 per cent., and 12.1 per cent., respectively. In some features the diversity between papers is very great Thus in one paper 19 per cent, of the interest is in sporting news, in another but 2 per cfent. In one paper 19.7 per cent, of the interest is in financial news, in another but 6.9 per cent. These last illustrations from sporting news and finance are exceptional instances, and even in these the extremes are found in the papers that were least often mentioned as the preferred papers. For all the papers and for all the different groups into which the business and professional men were divided the striking fact was the uniformity of interests. Features that were interesting to any group in any paper were usually found to be interesting in all the papers and to all the groups. The features that were most uniformly interesting were the news items, which possessed over seventy-five per cent, of the total interest. All other features were low in interest with most of the groups and in most of the papers. As is indicated in the tabulation above, advertisements did not seem to attract much attention. These results make it clear that the Chicago dailies are valued as NEWS papers and as little else. Local news, general news, foreign news, financial news, political news, and sporting news, — these monopolize the interest of business and professional men. Editorials, storiettes, book reviews, art, music, drama, society, — all these combined do not possess so much interest as local news alone. Every one seemed interested in news, and when cartoons and editorials were mentioned the writers were frequently careful to add that they were interested in these because they were a summary or index of some important news. Advertisements aiming to secure new subscribers to a newspaper should give most importance to the description of the news service of that particular paper. Other features might be mentioned, but the uniformity with which all groups expressed their interest in the news in each of the papers makes it quite certain that here we have the vital feature of the newspaper and that which gives it its name. The third question should be considered in connection with the fifth. (V. What induced you to begin the subscription of the paper or papers which you are now taking?) Immediately following the statement of the third question, as printed in the questionnaire, suggestive answers were presented. This list of examples acted as a constant suggestion and made it moi^e likely that the answers cited would be given than any original ones. No such suggestions were added to the statement of the fifth question and hence answers to this latter question are more reliable. While it resulted in the presentation of many different answers, still the uniformity with which the news items were mentioned — observed in the answers to the third question — is even greater here. Of all the motives that could be classified, the following show what per cent, of the total number of times each motive was mentioned : scattering mention. It is a significant fact that sixty-five per cent, of the business and professional men united in stating that the motive in first subscribing to their chosen papers was the desire to keep informed concerning current events. The following expressions were frequently used and are most suggestive: "to keep in touch with current events,'' "desire to be informed,'' "to be informed as to what is going on," "to be up to the times and not a back number," "to be en rapport with the world." In comparison with this desire for news of current events all other motives seem insignificant. News service is the desideratum. If a choice is to be made be- become the deciding factor. In waging a campaign to increase the circulation of newspapers the fact should be constantly before the advertiser's mind that people are interested primarily in the news. A description of the methods used by any great paper to secure the news would be a most powerful argument for securing new subscribers. A presentation of all the means employed to avoid mistakes, and hence to present the news accurately, would furnish a theme for further advertisements. A truly educational campaign carried on in the interests of the two theme» — completeness of news service and care to present the truth — would increase the circulation of any of the better metropolitan dailies. The questionnaire invited no criticisms of daily papers and yet many of these business and professional men volunteered criticisms which they inserted on the sheets of questions or else wrote them in personal letters that were enclosed. There are but few criticisms of the less important features of the papers. There are almost no criticisms of the storiettes, the society notes, the book reviews, the funny columns, etc. All these seem to be as good as desired ; nor does the reader express himself as aggrieved by the poor quality or even by the absence of any of them. In the main the criticism centered about the news service, the editorials, and the general lack of integrity of the papers. There was no criticism of the newspapers for failure to know the facts ; they were criticised rather for the failure to present an unbiased report. The same sort of criticism is made of the editorial columns. The editor is believed to be unduly influenced by the business manager. The phrase "the potent censorship of Big Business/^ or some analogous expression, occurred so often that it seemed to express a general lack of confidence. The present research was not devised to ascertain the degree of confidence in newspapers, and one would not be justified in asserting that the lack of confidence is general unless other grounds for the statement were at hand. The newspaper that would be preferred by the representative business and professional men might not be popular with other classes of society. Judging from the answers of two thousand men the conviction is forced upon one that they do not care to have a newspaper serve as interpreter, defender, or advocate of the truth. All that is desired is a brief but comprehensive publication of the news. That editor will be the most appreciated who selects the news most wisely and presents the unvarnished truth in all matters in which the constituency are interested. Some persons have no interest in the sporting pages; others never admit reading crimes and casualties. .Individual interests are so varied that no paper can expect general circulation without criticism from many readers because of the events emphasized in news gathering. However, the readers do not complain generally because of the presence of pages of material that they never read. The man who is not interested in finance, sports, etc., does not complain because of the presence of these things. He does complain because in place of a short and accurate account of things interesting to him, he finds long and inaccurate accounts of them. The ideal paper would have to do only with facts. The news would have to be well written, but the interest would be mainly in the news itself cerning it. There are many persons who read neither books nor monthly or weekly magazines. For them the daily newspaper must supply the place of all these. The storiette is their only literature. The editor and the reporter must interpret the daily events. The unbiased presentation of these daily events would not be adequate. For the business and professional man the circumstances are different. All of the two thousand business and professional men answering my questionnaire read much besides the daily papers. Their literary entertainment is found in books and magazines. The whole reading world desires to secure pleasure from literature, to read articles which champion its rights, and to follow some great leader in interpreting current events. That all these functions are performed in many instances by the daily press cannot be doubted. That the better class of society has passed beyond this condition is likewise apparent. The results as presented above make it quite evident that for the vast majority the daily paper is merely a news paper. For this class the ideal paper would be the one that serves this interest most perfectly. Cartoons would find a place in such papers but they would not be the same sort of cartoons that appear in the monthly comic papers. Editorials would find a place but they would be in the main concise statements concerning important events. Special articles would be in place in such a paper but they would deal in the main with current events. The ideal daily would put its emphasis on the field that is not covered by the weeklies and monthlies. It would also present the events of the day in such form that they could be read in fifteen minutes; for the busy man does not devote more than that time to any daily paper. The question which the advertiser is sure to raise in this connection is, What sort of advertisements could be valuable in what might be an ideal paper for the socalled better classes? If the ideal paper is fully ditferentiated from the weeklies and monthlies in its ^^literary departments/' has it not surrendered to them also the field of advertising except for the announcement of local sales and other similar events? Has it not ceased to be a competitor for national advertising? This conclusion does not follow ; for the ideal newspaper, which had the full confidence of its readers, would be a powerful medium for all classes of advertisements. Success in advertising is based on confidence, and one reason why advertising rates are higher in weeklies and monthlies for a proportionate amount of circulation is the fact that at the present time people have more confidence in these than in the dailies. Potential customers are not coldly logical and analytic in estimating commodities. An advertisement seen on garbage boxes may be a good advertisement and may announce real bargains but it possesses little influence. The same advertisement seen in a cherished household publication carries all the respect and trust that has been created by the other departments of the publication. We do not appreciate even good food if served upon dirty dishes. We are not influenced even by a good advertisement appearing in daily papers if they seem to us to be in any way unreliable. The present research was not undertaken to discover the value of newspapers as advertising media for the better class of society, but to ascertain which motives would appeal most profoundly to this class of society in inducing them to subscribe for newspapers. Incidentally the fact is revealed that the newspapers do not have the confidence of many of this particular class of society. If later researches discover the fact that the lack of confidence is general with this class of society, the results may be disquieting to the publishers, but it will result in the production of some newspapers which conform to the demands of this great and influential body of citizens. The sensational newspaper may possess the confidence of the lower classes of society and hence be a good advertising medium for reaching that class. Unless the newspapers are a valuable medium with the better classes, they are not serviceable for many of the most influential advertisers. The hope for relief from sensational journalism is to be found only in the discovery of the fact that a very influential class of business and professional men cannot be influenced by advertisements appearing in sensational publications. That this hope will be realized may be confldently anticipated if we may judge from the similar results which have been brought about of recent years in our best weeklies and monthlies. A few years ago all these publications contained advertisements of patent medicines, questionable financial schemes, etc. Many readers were interested in these advertisements and the space was well paid for. The significant fact was discovered, however, that more advertising space could be sold in high-grade magazines that did not accept such advertisements. The space in the cleaner publications was worth more, simply because such publications secured the confidence of the class of society that had the money necessary to purchase the advertised goods. The value of a publication as an advertising medium is in a large degree determined by the particular class of citizens whose confidence it possesses. This is shown in monthlies, weeklies, and dailies. For instance, for every thousand of circulation the advertising space in the Century Magazine is worth one hundred and seventyeight per cent, more than that in the Popular Magazine; and likewise, space in Collier's Weekly sells for two hundred and thirty-three per cent, more than space in Hearsfs Sunday Magazine. The Chicago evening papers are not able to secure so much for advertising space as the morning papers, circulation considered. The results of the investigation concerning the opinions of the two thousand Chicago business and professional men show that the Chicago paper which was most often preferred in proportion to its total circulation is the paper that secures, in proportion to circulation, a larger price than any of the others for its advertising space. That paper which was the least often preferred is the one which is compelled to sell its advertising space the cheapest, circulation being considered in both particulars. It will not be necessary for the better classes of society to boycott the firms advertising in the sensational newspapers — although such action might hasten the day of relief. If a large proportion of the better classes of society lack confidence in newspapers, then these publications are not so valuable as advertising media as they might be. Sooner or later the publishers will find out the facts. Newspapers are sure to conform to the demands of the people because any other policy would be suicidal on the part of the publishers. Probably from fifty to ninety per cent, of the total income from afiy newspaper is derived from its advertising pages. Anything which makes these pages valuable will be diligently sought for even though the policy adopted may reduce the total subscription list. the newspapers would ever be better than at present. The sentiment seemed to be common that they were getting worse. Two facts, however, render this pessimistic conclusion at least uncertain if not improbable. The first fact is that the newspapers are primarily dependent for their life upon the income from their advertising. The second fact is that the value of these pages is largely determined by the confidence which the public has in the paper as a whole ; for lack of confidence in one part is unconsciously extended to all parts. The better American metropolitan daily is a wonderful embodiment of enterprise. If it would be strengthened as an advertising medium by an increased confidence on the part of the better classes of society, it is quite certain that the publishers will be equal to the emergency and will produce a paper that meets the enlightened and cultured demands. The Questionnaire Method is available in securing data valuable in planning an advertising campaign. If the questions asked are reasonable and interesting and if the motives of the person carrying on the research are not questioned, a large proportion of business and professional men will fill out the blank. Most business and professional men read more than one daily and hence may be reached by an advertisement even though it is not inserted in all the papers. Advertisements inserted both in the best and also in the poorer papers are largely lost in the latter because of duplication of circulation. Most business and professional men spend about fifteen minutes daily reading papers. The amount of time spent in reading advertisements must be very small. Hence advertisements should be so constructed that they will carry their message at a single glance. Business and professional men subscribe for dailies because of the desire for news. Prizes, editorials, storiettes, etc., are of secondary importance in inducing these men to subscribe for any particular paper. These business and professional men lacked confidence in their preferred daily papers. Hence advertisements seen in such publications do not have the greatest possible influence. The newspaper is, from the publisher's point of view, primarily an advertising medium and can attain its maximum value only when it secures the full confidence of its readers. This fact may lead to an improvement in the ethical standards of our daily papers. THE SOCIAL SERVICE OF ADVERTISING The most widely known advertiser of the past generation worked on the assumption that the American public likes to be humbugged. The advertising of the late P. T. Barnum is still thought of by many as typical of all advertising. His style might be characterized as consummate skill in the use of bombast, hyperbole, and deceit. By glare of color, by exaggeration of description, and by grandeur of parades it bamboozled many innocent citizens into attending the menagerie, the circus, and the side shows. Such methods of advertising are so far removed from the methods pursued by continuous and successful advertising of to-day that it seems unjust to assign the same name to both. The advertising of Barnum was founded on the fact that he could hoodwink the public with profit to himself. Such advertising should be called hamboozling the public rather than advertising. The best advertising campaigns of to-day are founded on the assumption that the confidence of the public can be won by service rendered and when secured is the business man^s most valuable asset. Such advertising might properly be designated as the modern form of salesmanship. As human beings we are so organized into groups and subgroups that no one person can act in any way without affecting the other members of the group of which he is a member. If one negro commits a nefarious crime, all his race fall in our estimation. If one black man develops into a Booker T. Washington, we are likely to expect unprecedented evolution of his entire race. If by chance we come into contact with a Chinese gentleman of unusual intellectual and moral worth, we are inclined to look for the orientalization of the world. As our opinion of a whole race is prejudiced by a few individuals of that race, so too is our judgment of the classes within the race biased by a few examples. One notorious slugger and dynamiter prejudices a million against all laborers. One corrupt capitalist awakens a popular distrust of the well-to-do classes. If a single person can affect the reputation of his entire nationality, and if each member of a group can affect the reputation of the entire group, a single advertiser has to an extreme degree the power to affect the reputation of all advertisers. A dishonest advertiser is a double menace to all of his associates, not only because he actually deceives and defrauds the unwary, but also because by his wide publicity he subjects all advertisers to the scorn of the sophisticated. Modern advertising has the important and difficult task of overcoming the prejudice created by the exploiters of the past generation and perpetuated by the few disreputable advertisers of the present time. Of that number 17,855 asserted that they made use of advertisements. The remaining 3,965 declared that they never had answered advertisements, or else had ceased to do so. Of the 3,965 who did not answer advertisements, the overwhelming majority said they did not trust the statements of the advertisers. Practically all would have been glad to make use of advertisements and would have done so if it were not for this element of distrust. Of the 17,855 who had answered advertisements, over ninety per cent, of them reported that their experience had been perfectly satisfactory. This fact comes out in the results of the research: Although it is lack of confidence that makes the public hesitate to ansiver advertisements y yet the number of persons who, are disappointed in answering advertisements has become relatively small. 'No class of society, no professional, industrial, or commercial group can win and retain the confidence and respect of the public without adequate cause. In a recent research in social psychology, one hundred adults of experience were asked their judgments on these two questions: Fifty years ago, which group held most completely the respect and confidence of the American public, — ^^the lawyer, the physician, the business man, the minister, or the professor? To-day which group holds most completely the respect and confidence of the American public, — the lawyer, the physician, the business man, the minister, or the professor? The general consensus of opinion of the one hundred respondents was that the business man was clearly not the most respected fifty years ago, but that during these past five decades he had been progressing until to-day he outranks all his competitors in gaining the respect and confidence of the public. Fifty years ago the advertiser was one of the least respected members of one of the least respected classes of society. To-day he is one of the most highly respected members of the most highly respected class of society. Such a remarkable change in social status cannot be accidental, but is the result of a psychological law that will continue to control the further evolution of advertising. In general, society has given its most profound respect and confidence to that class of society which renders the service which is felt as the most insiste^it and most vital. Because of this fact the holders of social prestige differ from nation to nation and from age to age according as these needs change from time to time and from place to place. The most highly respected class in Germany previous to November, 1918, was clearly not the commercial class. Germany was comparatively a small country territorially and was surrounded on all sides by nations jealous of her and supposedly desirous of humiliating her. The most pressing need of the German was supposed to be protection from these dreaded foreign foes. The German army satisfied this need. The military man was therefore looked upon in Germany as the one indispensable member of society. He alone could perform the task which the patriotic Germans most desired to have accomplished. Because of this fact, the social prestige in Germany was held by the military class. Where possible, the German traced his ancestor to a man of military achievement. If a father, his ambition for his sons was that they might become officers in the army; his highest ambition for a daughter was that she might become the wife of a soldier. Every German took off his hat when he met an army officer. This homage was Fatherland. From the sixth to the thirteenth century, Europe was inhabited by peoples submerged in ignorance and superstition. The blight of the crop, the destruction of the cattle, the hurricane, disease, pain, and death were all looked upon as the working of unseen and supernatural powers. Their most pressing felt need was deliverance from these malign forces. Such a' deliverance was offered by the priest. The priest not only offered escape from future eternal punishment, but he interceded for the living individual as well, and freed him from the dread of unfriendly supernatural forces. The priest thus rendered the service which the individual felt as the profoundest necessity. As a result of such services, the priestly class was given the place of social prestige. The Emperor bowed down to the' Pope, and one-third of the soil of Europe passed by free-will offerings into the hands of the clergy. In every land and in all ages there is a felt need for the formulation, adjudication, and execution of laws. The criminal must be restrained, justice between citizens secured, and the rights of the individual protected. When the ruling class renders such service, society grants to the political ruler and to his associates unrivaled social prestige. From 1865 to 1900 the United States passed through a period of unprecedented commercial and industrial expansion. The most pressing felt need of the nation was the building of railroads, the stretching of wires, the sinking of wells, the digging of mines, the construction of manufacturing plants, and the organization of industry on a national and international scale. This was a service that the capitalist could and did render. Hence it was that during the period from 1865 to 1900 the capitalist was the American idol. We looked up to him and permitted him to dictate our laws and our national policy. Mothers discarded the traditions of Achilles, of David, and of King Arthur, but awakened the ambitions of their sons by narrating the achievements of the captains of industry. But, suppose a German army did preserve the nation from the fear of foreign aggression and did win the confidence and respect of the German; suppose the priesthood did free the medieval Europeans from the dread of unseen forces and thus secured the first place in the estimation of the inhabitants of the continent of Europe; suppose the ruling classes in many ages and nations have protected their peoples from injustice and oppression and thus won the fealty of their subjects ; suppose the capitalists in America 'have enabled the nation to organize her activities on a more extensive plan and have thus received in return the homage of all America, — what of all this? What has it to do with advertising? It has ordinarily been assumed that no man goes in for advertising except to make money, that it is not his purpose to shield the citizen from foreign aggressions, vj to protect the ignorant from unseen enemies, to banish fraud, or to organize industry for the benefit of the public in any way. The twentieth-century conception is that, although no man goes in for advertising unless he expects to find it profitable, the only way to make money in advertising is to render social service. Occasionally an ancient pirate retained his booty to the end. We all know of instances where by fraud and corruption fortunes have been amassed. Highwaymen, counterfeiters, forgers, and def rauders are not always restrained, yet we all agree that in business, honesty is the best polieyi Advertising is the outcome of a social evolution. The advertiser is, in the last analysis, the servant of the ultimate consumer. Only in so far as he proves to be an efficient servant does he receive the respect and confidence of his master, the ultimate consumer. To-day we have come to see that the crucial estimate of the work of the advertiser is service to the ultimate consumer. By approximating this standard the advertiser has arisen in social prestige. But until his advertising is conducted strictly in the interest of the ultimate consumer he will never win the complete confidence of the public and occupy the position of prestige to which he may possibly attain. But few, if any of us, to-day believe that the position of the United States among the nations of the earth is to be effected by military force. We are not likely to be invaded by a hostile army, and we are not likely to better our condition by conquest. Our national struggle is to be economic and not military. The greatest menace to America's prosperity to-day is the high cost of living. We have largely solved our problems of production and manufacture, but our problem of distribution is with the future. The cost which is added to the product, after it leaves the producer or manufacturer, and before it reaches the ultimate consumer, is so enormous that it would seem no people could continue to pay it year after year and not become impoverished. One single item in the distribution of merchandise is general advertising. America's annual contribution to such advertising is commonly estimated at \|800,000,000. It has been stated by various advertising experts that much of this adtertising is so unwisely done, that three-fourths of it is lost annually. The annual expense for traveling salesmen is said to approximate $1,600,000,000, or double that for general advertising. It is possible that if advertising were sufficiently well done, the number of traveling salesmen could be decreased so that the expense for such salesmen would be reduced to $800,000,000 annually; that is to say, $800,000,000, the expense of traveling salesmen, would be made equal to the amount now expended annually for advertising. This economy alone would save the American people $800,000,000 annually. Such an amount, if spent for food, and applied to the right places, would probably be sufficient to drive want from the home of every needy family in America. Every dollar squandered in distribution is lost to the ultimate consumer. On the other hand, the ultimate consumer receives the benefit from every dollar that is wisely spent on advertising, because efficient advertising is the most economical form known of distributing merchandise. One of the favorite questions for debate in the oldfashioned debating society was. Which is mightier, the pen or the sword? In Germany the soldier was better trained than the advertiser, the soldier's service was more important in the eyes of the patriotic citizen, and the soldier was esteemed more highly than the advertiser. But in Germany the new generation is less enthusiastic for war and more enthusiastic for commercial efficiency. In America the advertiser is as well trained as the soldier. The distribution of the necessities of life is recognized as a greater social service than intimidating Indians and strikers or parading on Decoration Day. If the advertiser renders a greater social service than the soldier, society will be willing to award him honor and fitting remuneration. the mightier influence for the prosperity of America than a musket in the hands of a national volunteer. Society ultimately rewards those who render needed service and it is no surprise that the advertiser is coming to his own in the estimation and esteem of our people. Until the last century the typical American family lived in the country or in a small village. The needs of the family appear to us to have been pathetically few. Practically all the provisions for the table were raised in the family garden or purchased from producers in the vicinity. If the flour was had from the miller, he was a neighbor known personally to all of his customers. Every man in the community knew the quality of wheat used for grinding and had watched the process of manufacture from the time the wheat left the bin until it was tied up as flour in the sack. The purchaser knew the products as well as did the manufacturer himself. The clothing was not infrequently spun and made up in the home. When garments were purchased, the buyer was in a position to judge of the quality and price of the goods, for the source of material and the method of manufacture were known to him. The principal method of transportation was by means of the horse. Every purchaser of a horse knew the weak and the strong points of the animal. Not infrequently he had known the horse by name from the time it was a colt. The seller and the buyer were on equal footing and the joy of trading horses was recognized among our ancestors. If any form of investment were to be made, it might be the purchase of real estate in the vicinity, a part interest in a neighboring industry, or perhaps a government bond. typical wants of our ancestors. The seller and the buyer possessed equal knowledge of the merchandise. This fact was recognized by law under the principle caveat emptor. Translated in simple English this legal term means, Let the purchaser beware. The legal assumption was, that if the purchaser exercised due precaution he would not be cheated. If he was cheated, no one was to blame but himself. Alas, alas, that the day of the self-sufficient and competent purchaser has passed ! You and I look with pity on the medieval European who, surrounded with the mysteries of pain and death, and oppressed with the dread of unseen powers, turned to the priest for guidance and protection. It is necessary but to call your attention to the fact that the ultimate consumer in America is in a position quite comparable to that of his or her ancient European ancestor. When the woman of the house steps to the telephone to order provisions for the morrow she is haunted with the visions of the unseen world — microbes, poison, adulterations, and substitutions. These are horrors and monsters of which personally she can have no knowledge and over which she can have no control. When she orders clothing for her household she fears that the prints are not permanent, that the woolens are cotton, and that the leather is paper. It is quite beyond her power to judge of the quality or the value of all her purchases. The buyer of an automobile, the holder of a ticket on a railroad or a steamboat, is unable to judge for himself as to the quality of material and workmanship that goes into the construction of his vehicle of transportation. tion in whose securities they invest their earnings. They are not in a position to investigate the business for themselves, nor can they afford to secure the services of competent attorneys or experts to make independent reports for them, because the cost of this investigation would as a rule far exceed the amount of the investment. The ultimate. consumer in America, in making his purchases, is in a peculiarly dependent condition. In case of need, society seeks a protection. At the present juncture the honest distributor, and particularly the honorable advertiser, is assuming the responsibility of protecting the ignorant. The publishers of some of our best magazines allow no advertisement to appear in their pages unless the firm placing the advertisement is financially and otherwise responsible, and unless the advertisement contains only statements deemed to be truthful. A few of the best advertising agencies refuse to give their advice to firms conducting questionable business. Such agencies refuse business on the ground that the merchandise offered for sale renders no social service — it neither reduces the cost of living nor adds to the richness of life. Our best mercantile houses exercise the greatest precaution to see that their advertisements in no way deceive the readers or arouse false hope. The advertisements are written, not mainly to dispose of a particular line of goods, but to provide possible customers with store news and to create good will. Likewise the advertising campaigns of our best "bond houses are planned, not primarily to sell any particular securities^ hut to educate the public to discriminate between sound and unsound investments. By such educational campaigns the public is being taught to be wary of investments exploited by promises of inordinately high income return or hy promises of certainty of rise in value. When the public is thus educated it avoids the tipster, the tout, and the man of the sure-thing gamble, and it seeks out the house that offers investment service, that offers a diversity of sound investment, that places safety above speculation, principle above high interest, and bases its business on its ability to keep its customers rather than on its ability to continue to get a lot of new business. One of the principal services rendered society by the political ruler and his associates is the creation of laws, their adjudication and execution. This service is tendered primarily in the interests of social justice. In the present state of the commercial world, our governmental powers are unable to render such service in any adequate degree. Mr. R. S. Sharp, Chief Post-Office Inspector, reports that during a recent year the American public handed over 177,000,000 to men who were later convicted of fraud. A large part of this \|77,000,000 was secured as a result of fraudulent advertising. Each year there is a new brood. The Post-Office Department is unable to prevent fraudulent advertising. The best it can do is to punish a few of the worst offenders after they have defrauded the public of millions of dollars annually and made the public suspicious of all advertisers. There is no force in America that can suppress fraudulent advertising and thus win the confidence of the public in advertisements except the advertisers themselves. The honest advertisers of America are awakening to the fact that they alone possess the power to eliminate the fraudulent advertiser. No advertising publication can flourish unless it receives the patronage of the reputable advertisers. When, therefore, the reputable advertisers refuse to buy space in publications carrying questionable advertisements the fraudulent advertiser is forced from the field. When reputable manufacturers refuse to place their accounts with agencies handling the business of any questionable firms, the criminal destroyers of public confidence are unable to exploit their commodities. In so far as educational advertising campaigns teach the public to discriminate between the honest merchant and the faker, the houses conducting,the campaigns not only gain customers, they also render a social service of incalculable value. During the last six or seven decades the capitalist has made possible the expansion of American industries. He has supplied the plant and the equipment. The railroads, the rural route, the irrigating ditch, the wells and the mines are now realities, and should be utilized in the service of the public. Expansion would be useless unless a comprehensive and economical method of distribution were provided. Because of these services, the capitalist has won our esteem, but the greater task of distribution is left to the advertiser. There is no real service in scientific manufacture on a large scale unless there can be a final reduction in cost to the ultimate consumer. When the cost of distribution shall have been lessened as has the cost of production, then, not the capitalist, but the advertiser will be heralded as the captain of industry. The advertiser in the past may have been the exploiter of the public, but the new generation of advertisers are becoming more and more the protectors of society. In the past they may have in all too many instances misled the unwary, but the successful advertisers of to-day are becoming the trusted guides of the ultimate consumer. The fraudulent advertiser has not yet become extinct, nevertheless the great body of advertisers in America is to-day one of the most substantial forces in protecting the public from fraud. BIBLIOGRAPHY The literature on the subject of advertising has enormously increased since the last revision of this work. The books cited in the following list have been carefully selected, and although some of them are of relatively minor significance, a familiarity with them is well worth the while of all vitally concerned with the science or the art of advertising; In view of the size of the present list it has seemed necessary to omit reference to the studies of specific forms of advertising such as bank advertising, drygoods advertising, etc. The prices given are neither complete nor vouched for as final. ADVERTISING AND ITS MENTAL LAWS. Macmillan Co., NeW York, 1916, pp. 333, $1.50. A psychological interpretation of advertising. A thoroughgoing attempt to reduce the complexities of printed advertisements to their elements. Scientific and reliable. Allen, Frederic J. ADVERTISING AS A VOCATION. Macmillan Co., New York, 1919. An excellent study of the subject of advertising. Traces its historical development. Describes carefully the methods and mediums of retail and manufacturing advertising. THE UNREACHED MILLIONS. American Association of ForeignLanguage Newspapers, New York, 1909, pp. 55. A short pamphlet which contains some interesting ideas on the advertising directed toward foreigners in this country. American Printer. THE AMERICAN MANUAL OF TYPOGRAPHY. The Oswald Publishing Co., Neiv York, 1905, pp. 105, $Jf.OO. An exhaustive exposition of the various phases of type-composition. This volume is prepared by a number of experts and represents the best, to date, in typography. LA PUBLICITE LUCRATIVE ET RAISONNEB. SON ROLE DANS LES AFFAIRES. Bihliotheque des ouvrages pratiques, 1909, pp. Jf36. The author claims this as the first work written in French on the subject. He describes it as a. study of advertising, its place, its methods, and its results. It is illustrated by accounts of the launching of notable advertising campaigns in France. Barsodi, William. advertising cyclopedia of selling phrases; short talks by merchants and advertisement writers, classified to facilitate the expression of ideas and assist merchants in general lines of business and specialists in the preparaTION OF ADVERTISING COPY. The Advertiscrs Cyclopedia Co., New York, 1909, pp. 1360, $15.00. Bates, Charles Austin. THE ART AND LITERATURE OP BUSINESS. Bates Advertising Co., New York, 1902, 6 volumes, pp. 2221, $25.00. The work contains no table of contents, and the index fills the entire sixth volume of 324 pages. The work is intended to be an encyclopedia of advertising although this is not made clear by the title. It is in the main a most creditable production and in spite of minor deficiencies should be a part of every advertiser's library. Bellamy, Francis, Editor. EFFECTIVE MAGAZINE ADVERTISING. With an introduction ''The Science of Advertising Copy," Mitchell Kennerley, New York, 1909, pp. 361, $5.00. Bird, Thomas Alexander. SALES PLANS. The Merchants' Record Co., Chicago, 1906, pp. 282, $2.50. A book filled with schemes for increasing business. A collection of three hundred and thirty-three successful ways of getting business, including a great variety of practical plans that have been used by retail merchants to advertise and sell goods. Breitwieser, Joseph Valentine. psychological advertising. Apex Book Co., Colorado Springs, 1915, pp. 167, $0.80. Evidently intended as a beginners' text-book. Touches lightly upon a number of topics. Bridgewater, Howard. advertising; or the art of making known: a simple exposition OF THE PRINCIPLES OF ADVERTISING. I. Pitman & Son, New York, 1910, pp. 102. A short book on the principles of advertising especially as applied to conditions in England. Bunting, Henry S. the premium system of forcing sales i its principles, laws, AND USES. Novelty News Press, Chicago, 1913, pp. 180, $2.00. A study of premium systems of various kinds and a plea for their use as an advertising device. Novelty News Press, Chicago, 1913, pp. 188. Written for the "business man" and deals with some of the recognized topics of advertising, such as media, circulation, appeal, etc. 1915, pp. 363, $2.00. A revision which has amounted to a complete rewriting of his earlier work, "Modern Advertising." Intended to "show briefly the work of those who deal in advertising." Casson, Herbert Newton. ads and sales '. a study of advertising and selling from the standpoint of the new principles of scientific manageMENT. A. C. McClurg & Co., Chicago, 1911, pp. 167, $2.00. A series of a dozen popular talks on advertising and salesmanship with practical illustrations. Castarede, L. de. MONEY-MAKING BY AD-WRITING. NeufYian and Castarede, London, 1905, pp. 367, 10s., 6d. This book is intended for beginners in advertising and contains the following chapters: Composition and Style in Writing Advertisements; Technical Proof and Press Corrections ; Block Type ; Illustrations; Small Advertisements; Newspaper Advertising; Magazine Advertisfng; Circularising; Eatio of Advertising to Eeturns; Poster Advertising; How to "Key" Advertisements; The Psychology of Advertising; also several other chapters of less importance. The author makes much use of the American contributions to the literature of advertis- ing. This is especially apparent in the chapter on "The Psychology of Advertising" which consists almost entirely of quotations from "The Theory of Advertising," by Scott, though no mention of this fact is made by the author. Cherrington, Paul Terry. advertising as a business force! a compilation of experiENCE RECORDS. Douhledap, Page d Co., Garden City, N.Y., 1913, pp. 569, $2.00. A thoroughgoing study of the practical problems of advertising, such as distribution, media, advertising for the retail and wholesale trades, premium systems, trademarks, disposals of costs, etc. Prepared as a text for the Educational Committee of the Associated Advertising Clubs of America. THE ADVERTISING BOOK. Douhlcday, Page & Co., Garden City, N.Y., 1916, pp. 604, $2.00. Prepared, like his earlier work, for the A. A. C. of W. Its chief purpose, the author states, is "to put into form for convenient reference some of the available records of recent progress in advertising methods." Highly instructive and entertaining reading. Clifford, William George. building your business by mail: a compilation of successful direct advertising campaigns drawn from the experience records of 361 firms representing every line op busiNESS. Business Research Puhlicity Co., Chicago, 1914, pp. 443, $2.00. A plea for direct advertising and its specific application to many kinds of merchandising. Cody, Sherwix. how to do business by letter and advertising*. a practical and scientific method of handling customers by written SALESMANSHIP. Cofistahle & Co., London, 1911, pp. 288, $1.50. A collection and explanation of sample letters to be used in general business procedure, sales and advertising campaigns. how to deal with human nature in business '. a practical book on doing business by correspondence, advertising, and SALESMANSHIP. Funk & Wagncills Co., New York, 1915, pp. 488, $2.00. An amplification of Ms earlier work, "How to do Business by Letter and Advertising." Contains additional chapters on tlie principles of salesmanship. Coleman, Edgar Werner. ADVERTISING DEVELOPMENT. PuhUsked by tlw author, Milwaukee, 1909, pp. 449' An account of the progressive development of advertising. Interestingly written. Curtis Publishing Company. SELLING FORCES. The Curtis Publishing Co., Philadelphia, 1913, pp. 288. Deals with the history of advertising, and with its present efficiency, machinery, and methods, and the consumer toward whom it is directed. Debower, Herbert Francis. ADVERTISING PRINCIPLES. Alexander Hamilton Institute, New York, 1917, pp. 330. One of a series of texts prepared for the Alexander Hamilton Institute. Treats of the pur- pose of advertising; the methods of getting the advertisement seen, read, understood, and acted upon; and the various instruments employed, such as trademarks, slogans, catalogs, etc. Deuch, Ernest Alfred. ADVERTISING BY MOTION PICTURES. The Standard Publishing Co., Cincinnati, 1916, pp. 255, $1.00. A study of the comparatively new method of motion-picture advertising. Takes up the respective values of slides and films and their application to different types of advertising; DeWeese, Trauman A. THE principles OF PRACTICAL PUBLICITY. The MatthewsNorthrup Works, Buffalo, 1906, pp. 2JfJf. A treatise on the art of advertising. Sold only as a part of Business Man's Library System Co., Chicago. The following are the chapter titles: Modern Commercial Publicity; What is Advertising? Mediums Employed by General and Direct Publicity; What is Good Advertising Copy? The Bull's-eye Method in Advertising; "Keason-Why Copy"; The Magazine and the Newspaper; Kelative Values of Magazine Pages; Mail-Order Advertising; Follow-up Systems; The Booklet in Mail-Order Advertising; "Keying" Mail-Order Advertisements; Bank Advertising; Street Car Advertising; Railway and Steamship Advertising; Outdoor Advertising; Planning an Advertising Campaign; The Advertising Agency. This is one of the best books on the subject of advertising. Dunn, Arthur., KEEPING A DOLLAR AT WORK. The New York Evening Post, New York, 1915, pp. 176, $1.00. Fifty short talks devoted to the importance of the newspaper in successful advertising and merchandising. SCIENTIFIC SELLING AND ADVERTISING. Industrial Publishing Co.f New York, 1919, pp. 119. Short exposition of some oftrepeated axioms of advertising. Eldridge, Harold Francis. MAKING ADVERTISING PAY. The State, Columbus, S.C., 1918, pp. 231. Deals with the economic and social side of advertising, with the application of psychological principles, and details specific methods adapted to retail and wholesale merchandising. THE TYPOGRAPHY OF ADVERTISEMENTS THAT PAY. D. AppletOH d Co., New York, 1918, pp. 282, $2.25. A classification of type faces and their application to certain general styles of advertising, e.g., the hand-lettered, the poster, the department store, etc., together with chapters on the combinations of types, of type with pictures, borders, margins, etc. A plea for a more thorough knowledge of typography among advertising men. Farrington, Frank. RETAIL ADVERTISING COMPLETE. The Byxhee Publishing Co., Chicago, 1910, pp. 270, $1.00. A dozen chapters, informally written, on methods of retail advertising such as windowtrimming, media, special sales, etc. 1880, pp. 160, $2.00. This volume treats of the same general subjects as the author's encyclopedia. This later book is, however, more adequate and is the product of later years. HOW TO advertise: a guide to DESIGNING, LAYING OUT, AND COMPOSING ADVERTISEMENTS. DouMeday, Page & Co., Garden City, N.Y., 1917, pp. 279, $2.00. Written for the A. A. C. of W. Shows the principles adopted from graphic arts, optics, and psychology that are behind effective advertising. Demonstrates the waste in advertising by concrete examples of ads that have made or missed their mark. Gale, Harlow. ON the psychology op ADVERTISING. PiihUshed by the author, Minneapolis, 1900, pp. 32, $0.75. The author of this pamphlet seems to have been the first to apply experimental methods to the subject. Galloway, Lee. ADVERTISING AND CORRESPONDENCE. Alexander Hamilton Institute, New York, 1913, pp. 606. Written as a text for the Alexander Hamilton Institute. Deals with the history of advertising; the pisychological factors involved in writing ads ; the technique of advertising, typography, illustrations, arrangement, etc., advertising media of all sorts ; sales and follow-up letters. Gerin, Octave Jacques, et Espixadel, C. la publicite suggestive, theorie et technique, avec preface DE M. WALTER DILL SCOTT. H. Dufiod and E, Pinat, Paris, 1911, pp. W. A thorough exposition of the subject of advertising. Treats of its history, its national characteristics, its value to the public, its theoretical laws, — suggestion, etc.; its practical laws, — optic, spacial, etc.; its media; its special devices such as trademark, mail order, houseorgan, etc.; and its legal regulations. GOODALL, G. advertising: a study op a modern business power. With an Introduction hy Sidney Wehh, Constable & Co., London, 191Jf^ pp. 91. A short treatise on advertising as an economic factor. Hawkins, George Henry H. NEWSPAPER advertising: BEING A SERIES OF TALKS ON THE VALUE AND USE OF THIS GREATEST OF ALL LOCAL ADVERTISING MEDIUMS — THE NEWSPAPER — WITH REPRODUCTIONS OF OVER 1,000 ACTUAL ADVERTISEMENTS. ALSO INCLUDES READY-MADE ADVERTISEMENTS, HEADINGS, AND CATCH PHRASES FOR EVERY LINE OF RETAIL BUSINESS, AND 58 PAGES OF INSERT REPRODUCTIONS OF ACTUAL ADVERTISEMENTS, WITH COMMENTS. Advertisers' Publishing Co., Chicago, 191^, pp. 119, $4-00. Henderson, R. Henderson's sign painter. Published by the author, Newark, N.J., 1906, pp. 112, $3.00. A compilation of the very best creations from the very best artists in their specialties, embracing all the standard alphabets; also all the modern Hess, Herbert Williams. PRODUCTIVE ADVERTISING. J. B. Lippificott, Philadelphia, 1915, pp. 358, $2.50. A general book on advertising. Includes chapters on the history of advertising; the part played in it by sense experience, instinct, imagination, attention; the technique of advertising; and other items of general interest. High AM, Charles Frederick. SCIENTIFIC DISTRIBUTION. NesMt d Co., Lofidon, 1916, pp. 170. A study of publicity as an economic factor. Describes the matter and manner of advertising, and offers suggestions as to its wider application. Hollixgsworth, Harry Levi. advertising and selling : principles of appeal and response. D. Appleton d Co., New York, 1913, pp. 310, $2.00. An investigation of the mental processes involved in the response to the advertising appeal as demonstrated by actual advertisements, and an attempt to anticipate by laboratory methods the effectiveness of new ones. A reliable and scientific study. Contains topical references for further study. HoYT, Charles Wilson. THE PREPARATION OF A MARKETING PLAN. Aft addrcss delivered before the Department of Business Administration of Yale University, 1917, pp. 22. Outlines a complete working plan for the marketing of a product by advertising. Concise and lucid. International Correspondence Schools.. RETAIL ADVERTISING. International Textbook Co., Scranton, Pa., 1905, 2 volumes, each of over JfOO pages, $4.00 per volume, hut not to he had except in sets of 5 volumes. The following are the chapter heads: Copy and Proof; Supplementary Advertising; Retail Advertising Management; Conducting an Advertising Office; Department Store Advertising; Advertisement Illustration; Advertisement Construction; Principles of Display; Illustrations in Newspaper Advertisements; Engraving Process; Advertisements for Various Businesses; Cyclopedia of Retail Advertisements and Selling Points; Printing-House Methods; Exhibit of Advertising Types and Borders. Each chapter is written by an expert. Chapters are being added from time to time and the whole "course" bids fair to be the best encyclopedia of advertising. LETTERING AND SIGN PAINTING. International Textbook Co., Bcranton, Pa., 1902, pp. 237, $4.00, but to be had only in connection with If other volumes {as above). SHOW-CARD writing. International Textbook Co., Scranton, Pa., 1903, pp. 172; in addition many pages of illustrations, $Jf.OO, but to be had only in connection with Jf other volumes {as above). FORM letters AND FOLLOW-UP SYSTEMS, CATALOGS, BOOKLETS, AND FOLDERS, MANAGEMENT OF GENERAL CAMPAIGNS, MISCELLANEOUS DETAILS OF MANAGEMENT, THE ADVERTISING AGENCY, advertising: copy for advertisements: correct and faulty diction: punctuation and editing: type and type measurements: layouts: proofreading. International TexthooTc Co., Scranton, Pa, advertiser's pocket book. International Textbook Co., Scranton, Pa., 1911, pp. JflS. A book of reference dealing with plans, copy, typography, illustration, media, management, and other details of advertising practice. TO become ACQUAINTED WfTH THE PRINCIPLES AND PRACTICES OF ADVERTISING. Pitman d Son, New York, 1912, pp. 133. Intended for the use of manufacturers planning an advertising campaign. Deals with the various practices of advertising, outdoor, press, etc. Kastor, E. ADVERTISING. La Salle Extension University, Chicago, 1918, pp. 317. Written for the business man and contains practical information on such topics as appeal, copy, layout, media, advertising agencies, etc. SI, $1.00. A short paper on the relation of different styles of type, spacing, etc., to the thought they are intended to convey. Illustrated by pages of sample type. QUENZEN. PfalziscJie Verlagsanstaldf, Neustadt a.d. Haardt, 1912, pp. 288. A general study dealing with the theory of advertising, its appeal, its value, and the relative merits of its various forms. Macdonald, J. Angus. SUCCESSFUL advertising: how to accomplish IT. The Lincoln Publishing Co., Philadelphia, 191)2, pp. JfOO, $2.00. The book contains the following five chapters: Advertisement Building; Eetail Advertising all the Year Around; Special Features in Eetail Advertising; Mail Order Advertising; Miscellaneous Advertising. The book contains much advice, numerous illustrations of good ways of saying things, and is altogether a helpful book for the beginner in advertising. Mahin, John Lee. advertising: selling the consumer. Douhleday, Page & Co., Garden City, N.Y., 1919, pp. 298, $2.00. Written for the A. A. C. of W. Describes the commercial status of advertising; its value; its tools; its media; the method of building and testing an advertisement; and takes up such specific topics as trademarks, mail order business, etc. Contains chapter references for supplementary reading. Martin, Mac. planning an advertising campaign for a manufacturer. Bulletin of the University of Minnesota, 1914, pp. 99. Maps out an advertising campaign by a thoroughgoing analysis of the product, its markets, channels of distribution, media, and the construction of its ads. advertising campaigns. Alexander Hamilton Institute, New York, 1917, pp. 338. Written as a text-book for the Alexander Hamilton Institute. Starts a campaign from the beginning with an analysis of the demand for the product, competition to be encountered, costs, methods of giving identity to the product, advertising technique, mediums and ways of estimating their value, testing success by sampling and other means. Mataja, Victor. die reklame. fine untersuchung "user ankundigungswesen UND werbetatigkeit im geschaftsleben. Duncker d Humhlot, Leipzig, 1910, pp. 489. An exhaustive study treating of the laws and principles of advertising, media, technique, and the legal regulations of advertising. SALES THROUGH RETURN POSTCARDS. DRAWN FROM THE EXPERIENCES AND RECORDS OF OVER 100 FIRMS REPRESENTING PRACTICALLY EVERY LINE OF BUSINESS. Selling Aid, Chicago, 1917, pp. 39. Moran, Clarence. THE BUSINESS OF ADVERTISING. Mcthucn & Co., Londoti, 1905, pp. 191, 2s. 6d. net. The book contains the following chapters: Advertising and its Utility; History of Advertising; Manual of Advertising; Advertising in the Press; Advertising by Circular; The Pictorial Poster (other chapters and appendices are purely local in interest). Opdycke, John Baker. news, ads and sales: the use of english for commercial PURPOSES. Macmillan Co., New York, 1914, pp. 193. A study of the ncAvspaper as an advertising medium. A comparison of it with other forms of advertising. ADVERTISING AND SELLING PRACTICE. A. W. Shaw Co., Chicago, 1918, pp. 230, $2.65. A clear exposition of the principles, practices, and methods of advertising and selling. Contains an extensive bibliography. THE PRACTICAL PHASES OF THE KIND OF ADVERTISING WHICH ANALYZES. Hausauer-Jones Printing Co., Buffalo, 1915, pp. 135, $2.00. Popular chapters on such topics as : How Best to Attract the Eye; How to Advertise the Half -Wanted Product, etc. Powell's practical advertiser. Published by the author, New York, 1905, pp. 229, $5.00. A practical work for advertisement writers and business men, with instructions on planning, preparing, placing, and managing modern publicity. With cyclopedia of over one thousand useful advertisements. Richards, William Hurst. POWER in ADVERTISING. Empire Printing Co., Kansas City, Mo., 1915, pp. 27 Ji, $2.00. A second book of the same general style as the first by this author. Richardson, A. O. THE POWER OF ADVERTISING. Lambert Publishing Co., New York, 1913, pp. 300. An interesting work on the social and economic value of advertising as well as its principles and technique. Co., Chicago, 1914, pp. 288, $3.25. About ten chapters are devoted to a study of the trademark as an advertising device and the methods of safeguarding same. EOGERS, W. S. A BOOK OF THE POSTER. Greening d Co,, London, 1901, pp. 158, 7s. 6d. Illustrated with examples of the work of the principal poster artists of the world. RowELL, George Presbury. FORTY YEARS AN ADVERTisixG AGEXT, 1865-1905. Printers' Ink PuUishing Co., New York, 1906, 517 pp., $2.00. The book contains no table of contents, but is subdivided into fiftytwo "papers"; the contents of the book are mainly reminiscence, but the style of the author is so pleasing that the papers will be found interesting even by those who have never known the author personally. Ruben, Paul. die reklame. ihre kunst und wissenschaft. herausge^ gebex von paul ruben, unter mitarbeit bekannter fachLEUTE, JURISTEN UND KUNSTLER. Verlag fUr Sozialpolitik, volumes 1 and 2, 1913-1^. A symposium in two large volumes of articles written by a dozen or more authors, on such topics as: The Makeup and Details of Advertising; American and German Advertising; Advertising in the Cigarette Industry; What we Accomplished in America through Advertising; Science in Advertising, etc. Sammons, Wheeler. MAKING more OUT OF ADVERTISING. A. W. Skaw Co., GMcago, 1919, pp. 285, $3.25. Describes the practical problems and details of advertising and how to handle them. Applies especially to the business of retail advertising. Sampson, Edith. ADVERTISE. D. C. Heath d Co., Boston, 1918, pp. 240. Interesting little book dealing with what ihe author terms the ten commandments of advertising. a history of advertising from the earliest times. chatto d Windus, London, 187^, pp- 616, 7s. 6d. Illustrated by anecdotes, curious specimens and biographical notes. The book is exactly what the title asserts and has supplied many an interesting story or illustration for speakers before advertising clubs. Scott, Walter Dill. THEORY of advertising. Small, Maynard & Co., Boston, 1903, pp. 2JtO, $2.00, net. A Simple Exposition^ of the Principles of Psychology in Their Kelation to Advertising. This book is the first volume in which psychological principles are thus applied, and hence the book may be said to have created a new era in the science of advertising. The book contains the following chapters: The Theory of Advertising; Attention; Association of Ideas; Suggestion; The Direct Command; The Psychological Value of the Eeturn Coupon; Psychological Experiment; Perception; Illusions of Perception; Illusions of Apperception; Personal Differences in Mental Imagery; Practical Application of Mental Imagery; Conclusion. Shaw, A. W., Company. HOW TO WRITE ADVERTISEMENTS THAT SELL. HOW TO PLAN every step in your campaign — USING SALES POINTS, SCHEMES, AND INDUCEMENTS. HOW TO WRITE AND LAY OUT COPY — CHOOSING PROSPECT LISTS AND MEDIUMS — TESTS AND RECORDS THAT Sherbow, Benj. MAKING TYPE WORK. Ceutury Co., New York, 1916, pp. 129, $1.25. A study of the part played by different forms of type in commanding attention, shifting the emphasis of attention, overcoming monotony, etc. Discusses also the matter of sub-heads, side-heads, margins, etc. ANALYTICAL ADVERTISING. Busifiess Service Corporation, Detroit, 1912, pp. 228. A discussion of psychology as it applies to advertising. Treats of such topics as sensation, attention, suggestion, reason, interest, habit, imagination. Shryer, W. a. sixteen hundred business books. h. w. whsou & co., New York, 1917. A bibliography, prepared by the Newark (N.J.) Free Public Library for the A. A. C. of W. The books are listed according to author, title, and subject. THE ART OF PUBLICITY AND ITS APPLICATION TO BUSINESS. T. F. Unwin, London, 1910, pp. 166. General discussion of tile subject of advertising covering such topics as: How to Attract and Eivet Attention; Cost; Media; Follow-up Letters; and Advertisement Construction. Co-operative Co., Madison, Wis., 1910, pp. 67, $1.00. A working outline of the factors involved in successful advertising, with topical references and suggestions for further study. Thorough and concise. Starch, Daniel. advertising : its principles, practice, and technique. scott, Foresman d Co., Chicago, 191Jf, pp. 281, $1.25. The author states this is an attempt "to combine the practical and theoretical aspects of the subject in such a way that the practical experiences of business houses, which are quoted at length, may illustrate the underlying principles, and that the discussion of principles may illuminate the practical results of business." A scientific and reliable treatment of the subject. One of the best books on the market. THE ART OF ADVERTISING. T. B. Brownc, Londofi, 1899, pp. 151, 3s. 6d. This is one of the best foreign books, but is not up to the American standard. THE RELATIVE MERITS OF ADVERTISEMENTS, A PSYCHOLOGICAL AND STATISTICAL STUDY. The Scieuce Press, New York, 1911, pp. 81. A careful study by laboratory methods of the relative values of certain well-known advertisements. Taylor, Henry C. what an advertiser should know: a handbook for every ONE WHO ADVERTISES. Browfie d Howcll, Chicago, 1914, PP95, $0.75. A short book on the practical problems of advertising. tative organs and liow to use tliem. The book is in the main a register of newspapers and other publications with a statement of the supposed circulation of each and the advertising rate. The book is published in the interests of an advertising agency and presents numerous illustrations of the work of the agency. Incidentally much information concerning advertising is presented. ADVERTISING, ITS PRINCIPLES AND PRACTICES. The Rofiald PVCSS, New York, 1915, pp. 575, $6.00. One of the most complete works on the subject of advertising. Considers the subject under the four headings : Economic Factors in Advertising ; Psychological Factors in Advertising; Practical Factors in Advertising; and The Technical Details of Advertising. the principles of advertising: a text-book. The Ronald Press Company, Neiv York, 1920, pp. 376, $3.50. This is a so-called "text edition," intended for school use and might be thought of as a later edition of "Advertising: Its Principles and Practices." Tregurtha, C, and Frings, J, W. the craft of silent salesmanship: a guide to advertisement construction. Pitman & Son, London, 1917, pp. 97. A thorough study of the process of preparing an ad for the press. Takes up such details as the "command" versus the "question" heading, sub-headings, admonition, signature, etc. AND Domestic Commerce. foreign publications for advertising AMERICAN GOODS, ADVERTISING RATES, circulation, SUBSCRIPTION PRICE, ETC. Government Printing Office, Washington. A list of foreign news Wilson, George Frederick. THE house-organ — HOW TO MAKE IT PRODUCE RESULTS. Washington Park Publishing Co., Milwaukee, 1915, pp. 199, $2.00. A study of the house-organ as a business asset. Gives technical details of its make-up and shows where it is most effective. Advertising Age and Mail Order Journal, Chicago, monthly. Advertising Club News, New York, monthly. Advertising and Selling, New York, monthly. Advertising World, Columbus, Ohio, monthly. Associated Advertising, New York, monthly. Bulletin (American Association of Newspaper Managers), Chicago, monthly. Business Digest and Investment Weekly, New York, weekly. Class (advertising in class publications), Chicago, monthly. Editor and Publisher, New York, weekly. Exclusive Distributor, Columbus, Ohio, monthly. Fourth Estate, New York, weekly. Independent Advertising, New York, monthly. Mailbag, Cleveland, monthly. THE STORY OF THE MIND. D. Applcton & Co., New York, 1901, pp. 232, small, $0.35. An excellent little book and is found by business men to be of interest and value. PSYCHOLOGY, BRIEFER COURSE. Henry Holt d Go., New York, 1900, pp. 478, $1.60. This is in many ways the most significant volume that has yet been written in English on psychology. The general reader may begin his reading of the book at page 134, as the first 133 pages involve a knowledge of physiology. TALKS TO TEACHERS ON PSYCHOLOGY. Henry Holt & Go., New York, 1901, pp. SOI, $1.50. Although this book was written primarily for teachers, it will be found valuable to business men. EMPLOYMENT PSYCHOLOGY. Macmillan Co., New York, 1919, pp. JfJfO, $2.50. A description of the application of scientific methods to the selection, training and grading of employees, as practiced by the author in large industrial plants. history and manual of personnel work in the u. s. army. U. S. Government Printing Office, Washington, D.C., 1919, 2 vols., $1.00 for the set. This work was written by the various members of the Committee on Classification of Personnel in the Army and is an authoritative account of the methods employed by the War Department in handling personnel in the world war. Terman, Lewis M. the measurement of intelligence i an explanation of and a complete guide for the use of the standard revision and extension of the binet-simon intelligence scale. Houghton Mifflin Co., New York, 1916, pp. 358, $2.10. Thorndike, Edward Lee. THE HUMAN NATURE CLUB. Longmans, Green & Co., New York, 1902, pp. 235, $1.25. The readers of this elementary work would doubtless desire some of the author's more advanced works after the completion of this introductory one. ARMY MENTAL TESTS. Henry Holt & Co., New York, 1920, pp. 303, $1.50. A complete account of mental testing in the army during the world war, including the forms used, the methods, and the practical applications of the results.	131,101	common-pile/pre_1929_books_filtered	advertpshycho00scotrich	public_library	public_library_1929_dolma-0009.json.gz:2559	https://archive.org/download/advertpshycho00scotrich/advertpshycho00scotrich_djvu.txt
dppYHU99HhqzWFuY	Radio Shack TRS-80 Expansion Interface: Operator's Manual Catalog Numbers: 26-1140, 26-1141, 26-1142	Produced by Gerard Arthus, Diane Monico, and the Online Distributed Proofreading Team at http://www.pgdp.net [Illustration: Radio Shack TRS-80 EXPANSION INTERFACE] Radio Shack TRS-80 EXPANSION INTERFACE _SEE CAUTION INSIDE COVER_ Catalog Numbers 26-1140 26-1141 26-1142 =Operator's Manual= CUSTOM MANUFACTURED IN U.S.A. FOR RADIO SHACK [TC] A DIVISION OF TANDY CORPORATION INTRODUCTION The TRS-80 Expansion Interface (see Figure 1) consists of the Case, a DC Power Supply, a Ribbon Cable, a Cassette Recorder Jumper Cable and an additional Cassette Recorder Cable for Cassette Recorder number 2. Notice that the DC Power Supply is not installed in the Case upon receipt. It must be installed using the procedures under the heading "SETTING UP" and as illustrated in Figure 2. The Case houses the Expansion Interface Printed Circuit Board (PCB), two DC Power Supplies and provides a housing area for an additional expansion PCB. The Expansion Interface utilizes a real-time clock and contains sockets for the addition of up to 32K of RAM in 16K increments. One DC Power Supply provides power to the PCB. The other one supplies power to the TRS-80. The Power Supplies are interchangeable. The ribbon cable has 40-pin connectors on both ends and is used to connect the Expansion Interface to the TRS-80. You received hoods for these connectors which are covered later in this manual. The Cassette Recorder Jumper Cable has 5-pin audio DIN connectors on both ends. It connects between the Expansion Interface Tape input/output (I/O) and the TAPE connector on the right rear of the TRS-80 Microcomputer. The Cassette Recorder Cable is provided to connect the Expansion Interface to Cassette Recorder number 2. CAPABILITIES AND ADVANTAGES The Interface allows you to add the following Radio Shack modules to your system: 1. Screen Printer (26-1151) 2. Line Printer (26-1150) 3. Mini-Disk System (26-1160/26-1161) 4. Cassette Recorder number 2 (14-841) The Screen Printer and Line Printer allow you to obtain hard copy (printed) information generated by your TRS-80. The TRS-80 Mini-Disk System is a small version of the floppy disk. It provides vast storage space and much quicker access time than tape. The number 1 disk contains about 80,000 bytes of free space for files. Each additional disk has 89,600 bytes of file space. The Disk System has its own set of commands that allow manipulation of files and expanded abilities in file use. The TRS-80 Mini-Disk System uses sequential or random access. The disks will allow use of several additional LEVEL II commands. =IMPORTANT NOTE= Because of the presence of a Disk Controller in the Expansion Interface, the computer will try to input the additional commands. When the Expansion Interface is connected to the computer, it assumes that a Mini-Disk is connected. To use the Expansion Interface without a Mini-Disk, press the BREAK key on the TRS-80 keyboard. This will override the Mini-Disk mode and allow normal LEVEL II operation. The use of two cassettes allows a much more efficient and convenient manner of updating data stored on tape. For example, if you have payroll data stored on tape, the information can be read, one item at a time, from Cassette Recorder number 1, then changed or added to and written out on Cassette Recorder number 2. The example cited is a very simple application; however, very powerful routines can be constructed to allow input and output of data using two tapes simultaneously. CAUTION This unit is designed to be used with Level II only. =Do not use with level I.= [Illustration: FIGURE 1. Expansion Interface.] Catalog Number Description RAM 26-1140 TRS-80 Expansion Interface 0K 26-1141 TRS-80 Expansion Interface 16K 26-1142 TRS-80 Expansion Interface 32K SETTING UP =Power Supplies and PCB Housing= (see Figure 2) Remove the Power Supply Door (top right side). First connect one DC power cord (DIN connector) to the Power connector on the PCB. Now install the two DC Power Supplies as illustrated. Route the remaining cords out the rear of the case. Be sure the power cords are seated in the door cutouts before replacing the Door. To gain access to the future expansion PCB Housing, remove the Expansion Door from the top left side of the module. [Illustration: FIGURE 2. Power Supplies and Future Expansion PCB Locations. (Illustration shows the following parts:) POWER SUPPLY DOOR EXPANSION DOOR RECESSES RECESSES HOUSING FOR FUTURE EXPANSION BOARD TRS-80 DC POWER SUPPLY REAR EXPANSION INTERFACE DC POWER SUPPLY AC POWER CORD DC POWER CORD NOTE: INSTALL EXPANSION INTERFACE DC POWER SUPPLY =FIRST=.] =NOTE= The term "port" as used in this manual refers to the openings into which the Cable connectors are inserted to provide an interconnection between the TRS-80 and the Expansion Interface modules. The ports, with the exception of the Expansion Interface port, are also covered by removable Doors. To remove these Doors, press on the right side of the Door and it will pivot slightly. Grasp the left side of the Door and pull out (see Figure 3 for locations). [Illustration: FIGURE 3. Expansion Interface, Front View--Doors Removed. (Illustration shows the following parts:) DOOR--MINI-DISK DOOR--LINE PRINTER PORT DOOR--FUTURE EXPANSION PORT DOOR--SCREEN PRINTER PORT] =Electrical Connections= (see Figure 4) Turn the TRS-80 so that it faces away from you. Locate the port Door (1400083); it's at the right end of the rear panel. To remove the Door, raise it up and slide it to the right--then lift it up and away from the TRS-80. Place the TRS-80 and Expansion Interface Hoods (14000217 and 14000214) on the Ribbon Cable Connectors as shown in Figure 4. The Hoods replace the Door on the TRS-80 and fill the opening on the Expansion Interface. These Hoods are designed so that it is not possible to insert the connectors upside down. They function as keyways for the connectors. Now connect the Ribbon Cable between the left front Expansion Interface port and the TRS-80 port. Connect the DC Power Cord (DIN connector) to the POWER connector on the right rear of the TRS-80 and connect both AC Power Cords to standard 120 VAC outlets. The interconnect cable for an expansion module is provided with that unit. See Figure 4 for Hood Assembly and Installation. Connect the Cassette Recorder Cable (DIN plug on one end and three plugs on the other) to the Tape I/O connector that is located on the rear of the Expansion Interface nearest the Power Cord exits. (Refer to Figure 5). Of the three plugs on the other end of the Cable: 1. Connect the black plug to the EAR jack on the side of the Cassette Recorder. 2. Connect the larger gray plug to the AUX jack. 3. Connect the smaller gray plug to the REM jack. =NOTE= A Dummy Plug is provided with your Cassette Recorder. Plug it in to the MIC jack. This Plug disconnects the built-in microphone so it won't pick up sounds while you are loading tapes. [Illustration: FIGURE 4. Front View--Interface Connections. (Illustration shows the following parts:) HOOD CONNECTOR AND CABLE TELEPHONE-TYPE CABLE LINE PRINTER EDGE CARD CONNECTOR WITH HOOD AND CABLE (ASSEMBLED) LINE PRINTER PORT (EDGE CARD) HOOD CONNECTOR AND CABLE FUTURE EXPANSION PORT (EDGE CARD) FUTURE EXPANSION EDGE CARD CONNECTOR WITH HOOD AND CABLE SCREEN PRINTER EDGE CARD CONNECTOR AND CABLE (ASSEMBLED) SCREEN PRINTER PORT (EDGE CARD) TRS-80 INTERFACE PORT (EDGE CARD) TRS-80 INTERFACE PORT HOOD CONNECTOR AND CABLE HOOD CONNECTOR AND CABLE DOOR - TRS-80 EXPANSION PORT TRS-80 PORT EDGE CONNECTOR HOOD CONNECTOR AND CABLE] Connect the Cassette Recorder Jumper Cable to the center DIN connector on the rear of the Expansion Interface. Connect the other end to the TAPE connector on the right rear of the TRS-80. Connect the Video Cable from the Video Display to the VIDEO connector on the right rear of the TRS-80. =NOTE= Your Cassette Recorders may be powered by batteries or from a 120 VAC source. Thus, AC power cords are optional. The TRS-80 Expansion Interface has been designed to support the Video Display module. Set the feet of the Video Display in the recesses in the Power Supply and PCB Housing Doors. (Refer to Figure 6). OPERATION =NOTE= The Power switch is recessed into the front of the Expansion Interface to prevent accidental loss of power. Activate the switch with the eraser-end of a pencil or small tool of similar size. Apply power to the Expansion Interface. Notice that when power is off, the end surface of the switch is white and when power is on, it changes to orange. CONCLUSION Possibly, you will not need all of the expansion modules that are available but, we have supplied you with Hoods for cable connectors for a complete expansion system. Use the Hoods as illustrated to prevent accidental mismatch between the edge connectors on the PCB and the cable connectors. In the event that you lose a Door or Hood and want to replace it, we have given you a Parts List. You may refer to the Parts List and exploded diagrams to determine its Part Number. You can order replacement parts through your local Radio Shack store. You must have a LEVEL II BASIC TRS-80 Microcomputer to utilize the TRS-80 Expansion Interface, the Line Printer and the Mini-Disk modules. If you have a LEVEL I BASIC machine, it must be modified to accept LEVEL II programs. The Screen Printer is the only expansion module that may be connected directly to the TRS-80 Microcomputer and that will operate with LEVEL I machines. We are continually improving and updating our TRS-80 Microcomputer System. You will be kept informed through our Newsletters (you are on the mailing list), addenda and revisions to the Manual. For the complete Electrical Connections Block Diagram, see Figure 7. [Illustration: FIGURE 5. Rear View--Interface Connections. (Illustration shows the following parts:) MINI-DISK HOOD CONNECTOR AND CABLE DOOR (MINI-DISK PORT) 5-PIN AUDIO DIN (FEMALE CONNECTORS) 5-PIN AUDIO DIN (MALE CONNECTORS) TO TRS-80 TAPE CONNECTOR] [Illustration: FIGURE 6. Placement of Expansion Interface.] +---------------+ +-----------+ \| VIDEO DISPLAY \| \| DC POWER \| \| \| \| SUPPLY \| +------+--------+ +----+------+ \| \| \| +---------------+ \| \| OPTIONAL +---------+ +------+-----+--+ +-----------+ __ \| SCREEN \|_________\| \|_______\| CASSETTE \|___/ \|= \| PRINTER \| \| TRS-80 \| \| RECORDER \| \__\|= +---------+ +---------------+ +-----------+ TRS-80 Microcomputer System Without Expansion Interface.] +---------+ \| SCREEN \|______SCREEN PRINTER ________ \| PRINTER \| INTERFACE CABLE \| +---------+ \| +---------+ \| +----------+ \| LINE \| LINE PRINTER \| \| CASSETTE \| _ \| PRINTER \|-------INTERFACE CABLE--+ \| +----\| RECORDER \|__/ \|= +---------+ P/N 6000910 \| \| \| \| (NO. 1) \| \_\|= \| \| \| +----------+ / \| \| \| / +---------+ +------+---+----+ \| OPTIONAL / \|MINI-DISK\|_________________\| EXPANSION \|--+ (CASSETTE___/ \|(NO. 1) \| \| \| INTERFACE \| RECORDERS \ +---------+ MINI-DISK +--\| 26-1140 \|--+ MAY BE \ MULTI CABLE \| +-+-----+-----+-+ \| OPERATED WITH \ P/N 6000911 \| \| \| \| \| BATTERIES) \ +---------+ \| \| \| \| \| \| \ \|MINI-DISK\| \| \| \| DC \| \| +----------+ \ \|(NO. 2) \|--+ \| \| POWER \| \| \| CASSETTE \| _ +---------+ \| FUTURE-+ \| SUPPLY \| +----\| RECORDER \|__/ \|= \| EXPANSION \| CORD \| \| (NO. 2) \| \_\|= \| CABLE \| \| \| +----------+ +---------+ \| \| \| \| \| \|MINI-DISK\| \| \| INTERFACE \| AUDIO DIN \|(NO. 3) \|--+ \| CABLE \| TO +---------+ \| \| ASSEMBLY \| AUDIO DIN \| \| P/N 6000907 \| P/N 6000909 \| \| \| \| \| +---------+ \| \| +-+-----+-----+-+ +---------+ \|MINI-DISK\| \| \| \| \| \| VIDEO \| \|(NO. 4) \|--+ FUTURE \| TRS-80 \|__VIDEO___\| DISPLAY \| +---------+ APPLICATIONS \| \| CABLE \| 26-1201 \| +---------------+ +---------+ TRS-80 Microcomputer System with Expansion Interface (maximum system). FIGURE 7. Electrical Connections Block Diagram.] PARTS LIST EXPANSION INTERFACE Door, Mini-Disk 1400212 Door, Line Printer 1400212 Door, Screen Printer 1400216 Door, Future Expansion Board 1400216 Hood, Mini-Disk 1400213 Hood, Line Printer 1400213 Hood, Screen Printer 1400218 Hood, Future Expansion Board 1400218 Hood, TRS-80 Microcomputer System 1400214 TRS-80 MICROCOMPUTER SYSTEM Door 1400083 Hood 1400217 LIMITED WARRANTY Radio Shack warrants for a period of 90 days from the date of delivery to customer that the computer hardware described herein shall be free from defects in material and workmanship under normal use and service. This warranty shall be void if the computer case or cabinet is opened or if the unit is altered or modified. During this period, if a defect should occur, the product must be returned to a Radio Shack store or dealer for repair. Customer's sole and exclusive remedy in the event of defect is expressly limited to the correction of the defect by adjustment, repair or replacement at Radio Shack's election and sole expense, except there shall be no obligation to replace or repair items which by their nature are expendable. No representations or other affirmation of fact, including but not limited to statements regarding capacity, suitability for use, or performance of the equipment, shall be or be deemed to be a warranty or representation by Radio Shack, for any purpose, nor give rise to any liability or obligation of Radio Shack whatsoever. EXCEPT AS SPECIFICALLY PROVIDED IN THIS AGREEMENT, THERE ARE NO OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AND IN NO EVENT SHALL RADIO SHACK BE LIABLE FOR LOSS OF PROFITS OR BENEFITS, INDIRECT, SPECIAL, CONSEQUENTIAL OR OTHER SIMILAR DAMAGES ARISING OUT OF ANY BREACH OF THIS WARRANTY OR OTHERWISE. RADIO SHACK [TC] A DIVISION OF TANDY CORPORATION USA.: FORT WORTH, TEXAS 76102 CANADA: BARRIE, ONTARIO L4M 4W5 TANDY CORPORATION AUSTRALIA 280-316 VICTORIA ROAD RYDALMERE N S W 2116 BELGIUM PARC INDUSTRIEL DE NANINNE 5140 NANINNE U K BILSTON ROAD WEDNESBURY WEST MIDLANDS WS10 7JN 478-PERKCO-2980084 PRINTED IN U.S.A.	4,670	common-pile/project_gutenberg_filtered	27469	project gutenberg	project_gutenberg-dolma-0003.json.gz:2325	https://www.gutenberg.org/ebooks/27469.txt.utf-8
C081gZqhE5IggSFP	22.2A: Enteric Nervous System	22.2A: Enteric Nervous System The enteric nervous system (ENS) is a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system. - Describe the structure and function of the enteric nervous system (ENS) Key Points - The enteric nervous system (ENS), which is embedded in the lining of the gastrointestinal system, can operate independently of the brain and the spinal cord. - The ENS consists of two plexuses, the submucosal and the myenteric. The myenteric plexus increases the tone of the gut and the velocity and intensity of contractions. The submucosal plexus is involved with local conditions and controls local secretion, absorption, and muscle movements. - While described as a second brain, the enteric nervous system normally communicates with the central nervous system (CNS) through the parasympathetic (via the vagus nerve ) and sympathetic (via the prevertebral ganglia) nervous systems, but can still function when the vagus nerve is severed. - The ENS includes efferent neurons, afferent neurons, and interneurons, all of which make the ENS capable of carrying reflexes and acting as an integrating center in the absence of CNS input. - The ENS contains support cells, which are similar to the astroglia of the brain, and a diffusion barrier around the capillaries surrounding the ganglia, which is similar to the blood –brain barrier of cerebral blood vessels. Key Terms - enteric nervous system : A subdivision of the peripheral nervous system that directly controls the gastrointestinal system. EXAMPLES The second brain of the enteric nervous system is the reason we get butterflies in our stomach or need to use the restroom more frequently when we are nervous and/or under stress. The gastrointestinal (GI) system has its own nervous system, the enteric nervous system (ENS). Neurogastroenterology is the study of the enteric nervous system, a subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system. The ENS is capable of autonomous functions such as the coordination of reflexes. Although it receives considerable innervation from the autonomic nervous system, it can and does operate independently of the brain and the spinal cord. The ENS consists of some 100 million neurons, one-thousandth of the number of neurons in the brain, and about one-tenth the number of neurons in the spinal cord. The enteric nervous system is embedded in the lining of the gastrointestinal system. Ganglia of the ENS The neurons of the ENS are collected into two types of ganglia: - The myenteric (Auerbach’s) plexus, located between the inner and outer layers of the muscularis externa - The submucosal (Meissner’s) plexus, located in the submucosa The Myenteric Plexus The myenteric plexus is mainly organized as a longitudinal chains of neurons. When stimulated, this plexus increases the tone of the gut as well as the velocity and intensity of its contractions. This plexus is concerned with motility throughout the whole gut. Inhibition of the myenteric system helps to relax the sphincters —the muscular rings that control the flow of digested food or food waste. The Submucosal Plexus The submucosal plexus is more involved with local conditions and controls local secretion and absorption, as well as local muscle movements. The mucosa and epithelial tissue associated with the submucosal plexus have sensory nerve endings that feed signals to both layers of the enteric plexus. These tissues also send information back to the sympathetic pre-vertebral ganglia, the spinal cord, and the brain stem. Neural control of the gut : An illustration of neural control of the gut wall by the autonomic nervous system and the enteric nervous system. Function and Structure of the ENS The enteric nervous system has been described as a second brain. There are several reasons for this. For instance, the enteric nervous system can operate autonomously. It normally communicates with the central nervous system (CNS) through the parasympathetic (e.g., via the vagus nerve) and sympathetic (e.g., via the prevertebral ganglia) nervous systems. However, vertebrate studies show that when the vagus nerve is severed, the enteric nervous system continues to function. In vertebrates, the enteric nervous system includes efferent neurons, afferent neurons, and interneurons, all of which make the enteric nervous system capable of carrying reflexes and acting as an integrating center in the absence of CNS input. For instance, the sensory neurons report mechanical and chemical conditions, while the motor neurons control peristalsis and the churning of intestinal contents through the intestinal muscles. Other neurons control the secretion of enzymes. The enteric nervous system also makes use of more than 30 neurotransmitters, most of which are identical to the ones found in the CNS, such as acetylcholine, dopamine, and serotonin. More than 90% of the body’s serotonin is in the gut, as well as about 50% of the body’s dopamine, which is currently being studied to further our understanding of its utility in the brain. The enteric nervous system has the capacity to alter its response depending on factors such as bulk and nutrient composition. In addition, the ENS contains support cells that are similar to the astroglia of the brain, as well as a diffusion barrier around the capillaries that surround the ganglia, which is similar to the blood–brain barrier of the cerebral blood vessels. Regulation of ENS Function The parasympathetic nervous system is able to stimulate the enteric nerves in order to increase enteric function. The parasympathetic enteric neurons function in defecation and provide a rich nerve supply to the sigmoid colon, the rectum, and the anus. Conversely, stimulation of the enteric nerves by the sympathetic nervous system will inhibit enteric function and capabilities. Neurotransmitter secretion and direct inhibition of the enteric plexuses cause this stall in function. If the gut tract is irritated or distended, afferent nerves will send signals to the medulla of the brain for further processing.	1,244	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/22%3A_Digestive_System/22.02%3A_Nervous_System_of_the_Digestive_System/22.2A%3A_Enteric_Nervous_System	libretexts	libretexts-0000.json.gz:45951	https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/22%3A_Digestive_System/22.02%3A_Nervous_System_of_the_Digestive_System/22.2A%3A_Enteric_Nervous_System
FPJlVsDdshdDdzxi	Bird Day; How to prepare for it	Produced by Bryan Ness, Sankar Viswanathan, and the Online by the Library of Congress) BIRD DAY HOW TO PREPARE FOR IT BY CHARLES A. BABCOCK, A.M., LL.B. _Superintendent of Schools, Oil City, Pennsylvania_ SILVER, BURDETT AND COMPANY NEW YORK BOSTON CHICAGO COPYRIGHT, 1901, BY SILVER, BURDETT AND COMPANY THIS BOOK IS DEDICATED TO THE LOVERS OF CHILDREN AND OF BIRDS AUTHOR'S NOTE The aim of this book is to assist school children in the accurate study of a few birds. It is believed that if this be attained, further study of birds will take care of itself. Thanks are due the Audubon Society, ornithologists, educators, and legislators, for the generous approbation and assistance which they have given the Bird Day movement. Special thanks are due the Department of Agriculture for permission to use the illustrations in this volume. Those on pages 65, 67, 69, 71, 73, 75, 77, 79, 85, 87, 89, 93, and 95 are printed from electrotypes from the original illustrations appearing in "Farmer's Bulletin," No. 54. Those on pages 81 and 83 are from the Yearbook of the Department for 1899, and that on page 91 from the Yearbook for 1898. All these publications are issued by the Department. CONTENTS I. HISTORY OF THE MOVEMENT FOR "BIRD DAY" II. THE VALUE OF BIRDS III. THE DESTRUCTION OF BIRDS IV. PLAN OF STUDY V. FURTHER SUGGESTIONS VI. DIRECTIONS FOR WRITTEN WORK VII. PROGRAMS FOR BIRD DAY VIII. THE POETS AND THE BIRDS IX. OBJECTS AND RESULTS OF BIRD DAY X. SOME REPRESENTATIVE BIRDS PART I BIRD DAY. HOW TO PREPARE FOR IT BIRD DAY HOW TO PREPARE FOR IT HISTORY OF THE MOVEMENT FOR "BIRD DAY" In the spring of 1894 the writer's attention was attracted to the interest of the children in that part of their nature study which related to birds. Their descriptions of the appearance and habits of the birds they had observed were given with evident pleasure. They had a strong desire to tell what they had seen, not in the spirit of rivalry, but with the wish of adding to the knowledge of a subject in which all were equally interested. It was thought that this work would be done with even more effectiveness if a day were appointed to be celebrated as "Bird Day." With the hope of making a memorable occasion of the day for those taking part in it, several of the noted friends of birds were asked to write something to the children, and to give their opinion of the introduction of "Bird Day" into the schools. Secretary J. Sterling Morton, the father of "Arbor Day," responded with the following earnest letter, which was at once given to the public through Washington dispatches, and later was sent out from the Department of Agriculture, in circular No. 17:-- WASHINGTON, D. C., April 23, 1894. MR. C. A. BABCOCK, SUPERINTENDENT OF SCHOOLS, OIL CITY, PA. _Dear Sir_,--Your proposition to establish a "Bird Day" on the same general plan as "Arbor Day," has my cordial approval. Such a movement can hardly fail to promote the development of a healthy public sentiment toward our native birds, favoring their preservation and increase. If directed toward this end, and not to the encouragement of the importation of foreign species, it is sure to meet the approval of the American people. It is a melancholy fact that among the enemies of our birds two of the most destructive and relentless are our women and our boys. The love of feather ornamentation so heartlessly persisted in by thousands of women, and the mania for collecting eggs and killing birds so deeply rooted in our boys, are legacies of barbarism inherited from our savage ancestry. The number of beautiful and useful birds annually slaughtered for bonnet trimmings runs up into the hundreds of thousands, and threatens, if it has not already accomplished, the extermination of some of the rarer species. The insidious egg-hunting and pea-shooting proclivities of the small boy are hardly less widespread and destructive. It matters little which of the two agencies is the more fatal, since neither is productive of any good. One looks to the gratification of a shallow vanity, the other to the gratification of a cruel instinct and an expenditure of boyish energy that might be profitably diverted into other channels. The evil is one against which legislation can be only palliative and of local efficiency. Public sentiment, on the other hand, if properly fostered in the schools, would gain force with the growth and development of our boys and girls, and would become a hundredfold more potent than any law enacted by the State or Congress. I believe such a sentiment can be developed, so strong and so universal that a respectable woman will be ashamed to be seen with the wing of a wild bird on her bonnet, and an honest boy will be ashamed to own that he ever robbed a nest or wantonly took the life of a bird. Birds are of inestimable value to mankind. Without their unremitting services our gardens and fields would be laid waste by insect pests. But we owe them a greater debt even than this, for the study of birds tends to develop some of the best attributes and impulses of our natures. Among them we find examples of generosity, unselfish devotion, of the love of mother for offspring, and other estimable qualities. Their industry, patience, and ingenuity excite our admiration; their songs inspire us with a love of music and poetry; their beautiful plumages and graceful manners appeal to our æsthetic sense; their long migrations to distant lands stimulate our imaginations and tempt us to inquire into the causes of these periodic movements; and finally, the endless modifications of form and habits by which they are enabled to live under most diverse conditions of food and climate--on land and at sea--invite the student of nature into inexhaustible fields of pleasurable research. The cause of bird protection is one that appeals to the best side of our natures. Let us yield to the appeal. Let us have a Bird Day--a day set apart from all the other days of the year to tell the children about the birds. But we must not stop here. We should strive continually to develop and intensify the sentiment of bird protection, not alone for the sake of preserving the birds, but also for the sake of replacing as far as possible the barbaric impulses inherent in child nature by the nobler impulses and aspirations that should characterize advanced civilization. Respectfully, J. STERLING MORTON, _Secretary of Agriculture._ Other friends of the birds responded cordially to the request, as will be seen by the following letters:-- WEST PARK, N. Y., April 22, 1894. _Dear Sir_,--In response to yours of the seventeenth, I enclose a few notes about birds to be read upon your "Bird Day"--just an item or two to stimulate the curiosity of the young people. The idea is a good one, and I hope you may succeed in starting a movement that may extend to all the schools of the country. Very truly yours, JOHN BURROUGHS. 628 HANCOCK STREET, BROOKLYN, N. Y., April 25, 1894. MR. C. A. BABCOCK. _Dear Sir_,--Yours of the nineteenth is received. I am delighted to know that your school children are to have a "Bird Day." I wish I could be there to tell them something of the delight of getting acquainted with their little brothers in feathers; how much more interesting they are when alive and doing all sorts of quaint and charming things than when dead and made into "skins" or stuffed; and how much greater is the pleasure of watching them to see how they live, where they get their dinner, how they take care of themselves, than of killing them, or hurting them, or even just driving them away. If the boys and girls only try keeping still and watching birds to see what they will do, I am sure no boy will ever again want to throw a stone at one, and no girl ever to have a dead bird on her hat. Very truly yours, OLIVE THORNE MILLER. CLINTON, April 30, 1894. _My Dear Sir_,--It strikes me that your idea is a particularly happy one. Should you institute a "Bird Day," the feathered tribe ought to furnish music for the occasion. A chorus of robins and thrushes and a few other songsters would be more appropriate than an orchestra. With thanks for your cordial good wishes, I am, Yours faithfully, CLINTON SCOLLARD. From the Department of Public Instruction of Pennsylvania this encouraging letter was received:-- HARRISBURG, April 27, 1894. SUPERINTENDENT C. A. BABCOCK. _Dear Sir_,--In your plan to inaugurate a "Bird Day" you have struck a capital idea. When in the name of agriculture a scalp act can be passed resulting in a year and a half in the payment of $75,000 by the county treasuries of Pennsylvania for the destruction of birds that were subsequently proved to belong to the feathered friends of the farmer, it is high time to make our pupils acquainted with the habits and ways of the feathered tribes. Some birds remain with us the whole year, others are summer sojourners, still others are only transient visitors. How much of the beauty of our environment is lost by those who never listen to the music of the birds and never see the richness of their plumage! May success attend you in carrying out your new idea of a "Bird Day." Very truly yours, NATHAN C. SCHAEFFER, _Superintendent of Public Instruction_. Bradford Torrey gives an additional title to the day, showing his appreciation of it:-- WELLESLEY HILLS, MASS., April 21, 1894. _Dear Mr. Babcock_,--Your young people are to be congratulated. "Bird Day" is something new to me--a new saints' day in my calendar, so to speak. The thought is so pleasing to me that I wish you had given me its date, so that in spirit I might observe it with you. Tell your pupils that to cultivate an acquaintance with things out of doors--flowers, trees, rocks, but especially animate creatures, and best of all, birds--is one of the surest ways of laying up happiness for themselves; and laying up happiness is even better than laying up money, though I am so old-fashioned a body and so true a Yankee as to believe in that also. All the naturalists I have known have been men of sunny temper. Let your boys and girls cultivate their eyes and ears, and their hearts and minds as well, by the study of living birds, their comings and goings, their songs and their ways; let them learn to find out things for themselves; to know the difference between guess-work and knowledge; and they will thank you as long as they live for having encouraged them in so good a cause. With all good wishes for the success of your first "Bird Day"--and many to come after it, Very truly yours, BRADFORD TORREY. The first observance of "Bird Day," May 4, 1894, is briefly set forth in the following paragraph from the _New England Journal of Education_:-- The day was observed in the Oil City schools with a degree of enthusiasm which was good to see. The amount of information about birds that was collected by the children was simply amazing. Original compositions were read, informal discussions were held, talks by teachers were given, and the birds in literature were not forgotten or overlooked. The interest was not confined to the children, one gentleman surprising the classes in which his children celebrated the day by presenting to them artistic programs of the exercises. It seems to those interested that the idea simply needs to be made known to meet with a warm welcome, akin to that with which we greet our first robin or song sparrow in the spring. II THE VALUE OF BIRDS Probably few people understand the value of birds or comprehend how closely and yet how extensively their lives are interwoven with other forms of life. The general sentiment in regard to them, at the best, has been that they are harmless, even interesting and beautiful creatures; but the idea that they are one of the most important classes of creation, a class upon which the existence of many other classes depends, has never been widely prevalent. Suppose we were asked which is of more use to man, the fishes of our waters or the birds of our forests and fields? Many of us would unhesitatingly answer in favor of the fishes. If all of these denizens of the rivers, lakes, and seas should be destroyed, it would be a stupendous calamity. Mankind would universally deplore it; and if the nations of the world should, at any time, become convinced that such a thing might occur, how quickly they would take all possible means to prevent it! All civilized people now have laws to preserve this food supply and are making expensive and laborious efforts to increase it. Any one who should destroy thousands of tons of these edible swimmers, simply for their heads and tails, or fins and scales, would be regarded as a dangerous person. But if our supposition were realized, if every fin and gill were to disappear from the waters of the globe, what would be the result? A misfortune, truly, for the fins represent a large part of the world's supply of food, and this loss would be felt more deeply as time went on, because the ocean will not raise its rent, however crowded may be the population of its shores. The effort to secure the fish might be applied, however, in other directions and be equally remunerative. Harvest would still follow seedtime; the gold of autumn still reward the shallow mines of spring. But suppose we were forced to the dreadful alternative of choosing between the birds and the quadrupeds, again, the most of us would probably decide against the birds. If the four-footed beasts should disappear from the earth, it would be a much greater disaster than the destruction of the fishes. A much larger fraction of the food supply would be lost; while many of these animals contribute to man's comfort and necessities in almost innumerable ways. Most nations have learned to cherish their friends with hoofs and horns, and even some of those with claws. Cruelty to animals is now generally forbidden by law; and their wanton destruction would be regarded with horror. No one would be permitted to slaughter large numbers of them because he might wish to sell their horns or ears or the tips of their tails. By the departure of the quadrupeds the life of man would be rendered much more difficult, but would still be possible. From fish and fowl he could obtain a supply of meat limited in variety, yet sufficient for his needs. The treasures of the vegetable world would still be his, though he would miss the help of his animal allies in securing them; but his ingenuity would help him to supply this loss, in part, at least. Consider now what would be the effect of the total destruction of birds. Birds are nature's check to the amazing power of insects to increase. If insect life were allowed free course, it would soon overpower vegetation; and plant life--and, therefore, animal life, including that of man--would be impossible upon this globe. This is an astounding conclusion, but it is sustained by the judgment of every man of science who has investigated the subject. How long could the ravages of insects be stayed were the birds gone? We should have to depend upon a few predaceous beetles, the bats, and upon the sprayers and squirtguns which throw insecticides. Think of the æsthetic loss in substituting these agencies for the "sweet spirits" of the wood and field! Besides not being musical or charming in action, they would not prove efficient. Birds are therefore essential to the life of man. Their preservation is not merely a matter of sentiment, or of education in that high and fine feeling, kindness to all living things. It has a utilitarian side of vast extent, as broad as our boundless fields and our orchards' sweep. The birds are nature's guarantee that the reign of the crawlers and spinners shall not become universal. The "plague of locusts" shall be upon those who sin against them. THE DESTRUCTION OF BIRDS From almost all sections of the country comes the plaint that the song birds are fast disappearing. Less and less numerous are the yearly visitations of the thrushes, warblers, song sparrows, orioles, and the others whose habits have been so delightful and whose music has been so cheering to their open-eyed and open-hearted friends. Many, who when listening to the hymn-like cadences of the wood thrush have felt that the place was holy ground, are now keenly regretting that this vesper song is so rare; the honest sweetness of the song sparrow mingles with the coarser sounds less often in the accustomed places. Not many now find "the meadows spattered all over with music" by the bobolink, as Thoreau did. John Burroughs says that the bluebird is almost extinct in his section of country. The writer, though a frequent visitor to the fields and woods, has succeeded in seeing only one pair of these beautiful birds in two seasons, where they were abundant a few years ago, when almost every orchard bore a good crop of them. A friend who is a good observer has had the same experience. A careful exploration of the country within a radius of five miles resulted in the discovery of only two pairs of bobolinks, having their nests luckily in the same field. The males sang together in friendly rivalry. The sparkling, tinkling notes seemed to come in a rippling tumble, two or three at a time, from each throat. Each started his song with his feet barely touching his perch, his body quivering, his wings half extended, as if he were almost supported by the upward flow of his melody. After circular flights he alighted first upon one frail, swinging perch, then upon another, the wonderful sounds not ceasing, as if he were tracing magic rings of song round his home, and making them thick in places. It was a musical embodiment of the love of life and of its joyousness. The brown thrush is also absent from places where once there were many. A farmer in this neighborhood states that a few years ago the treetops near his house seemed to be filled with these fine singers. Now he hears only one or two during the season. Last May the writer found three nests at least a mile apart, but they were destroyed before the time of hatching, and the birds went about silent as if brooding upon their trouble. It is doubtful if they will build next season in that vicinity. No doubt the clearing away of the forests and the settling up of the country are responsible for the scarcity of the birds in part, but only in part. If they were let alone, many of the most interesting and useful birds would build near even our city homes, and our gardens and fields would again become populous with them. The wearing of feathers and the skins of birds for ornament is the chief cause of the final flight of many of our songsters. It is stated that a London dealer received at one time more than thirty thousand dead humming birds. Not only brightly colored birds, but any small birds, by means of dyes, may come at last to such base uses. It is estimated by some of the Audubon societies that ten million birds were used in this country in one season. All these bodies, which are used to make "beauty much more beauteous seem," are steeped in arsenical solutions to prevent their becoming as offensive to the nostrils of their wearers as they are to the eyes of bird lovers. The use of dead birds for adornment is a constant object lesson in cruelty, a declaration louder than any words that a bird's life is not to be respected. It is currently reported that a million bobolinks were destroyed in Pennsylvania alone last year to satisfy the demand of the milliners. If this "garniture of death" is in good taste, then our North American Indian in his war paint and feathers was far ahead of his time. Let us hope that some oracle of fashion will decree that if the remains of animals must be used for adornment, the skins of mice and rats shall be offered up. Their office seems to be principally that of scavengers, and their gradual but certain extinction would not matter if the Christian nations should become, _pari passu_, more cleanly. The squirrel could also be used effectively, mounted as if half flying, with his hind feet fastened to the velvet pedestal, or sitting upon his haunches with a nut between his fore paws. The squirrel's main concern seems to be to prevent the undue extension of the nut-bearing trees--an office man has already well taken upon himself--and besides, he destroys fruit, injures trees, and is a great enemy of birds. His gradual extinction would be tolerated by a civilized nation. All these things may take the hues of the rainbow and are capable of infinite variety of arrangement. There certainly seems to be no good reason why in a few years some combination of them may not be considered as effective as a row of dead humming birds. The world may be saved in this way from presenting a spectacle that should excite the pity of gods and men--the spectacle of the destruction of one of the most beautiful, the most harmless, and the most useful classes of creation, at the command of the senseless whims of fashion. Then, too, the sportsmen's guns and the small boys' slings and shooters of various sorts are constantly bringing down numbers of the feathered songsters. In many parts of our country men and boys roam the fields, shooting at every bird they see, and their action is tacitly approved by the community. This survival of the barbarous instinct to kill is condoned as "sport." If these people were to spend this time in following the birds with opera glass and notebook to study them, they might not be so readily understood--they might even be taken for mild lunatics, so utterly is public sentiment perverted on this subject. A little consideration shows this destruction to be more disastrous than at first appears. According to the latest biological science, every species of animals must have long ago reached the limit beyond which it could not greatly increase its numbers. However great its tendency to increase might be, its natural obstacles and enemies would increase in like proportions till at last the two would balance each other, and there could be no further increase in the number of individuals of that species. All classes of animals in a state of nature must have reached this balanced condition generations ago. This is true of the birds. Their natural enemies are capable of preventing their increase; that is, they can and do destroy every year as many as are hatched that year. Now if man be added as a new destructive agency, the old enemies, being still able to destroy as many as before, will soon sweep them out of existence. Warnings have been sent out by the United States Department of Biology that several species of birds are already close to extinction. We know that this is true of the passenger pigeon. This bird used to come North in flocks so extensive as sometimes to obscure the sun, like a large, thick cloud. Now they come no more. Italy is practically songless, we are told. If man would right the wrong that he has done, he must not only stop destroying the birds, but he must take all possible means to preserve them and to protect them from their natural foes. Laws for bird protection have been passed in many of our states; but these have been found effective only where they were not needed. They are, however, right, and will help in the development of correct sentiment. What is most needed is knowledge of the birds themselves, their modes of life, their curious ways, and their relations to the scheme of things. To know a bird is to love him. Birds are beautiful and interesting objects of study, and make appeals to children that are responded to with delight. Children love intensely the forms of nature--the clouds, the trees, the flowers, the animals--all of the great beautiful world outside of themselves, and it is their impulse to become acquainted with this world; for this they feel enthusiasm and love. Marjorie Fleming, the little playmate of Scott, who at the age of six could recite passages from Shakespeare and Burns so that the great bard would sob like a child or shout with laughter, may be taken as the universal voice of childhood. She writes in her diary, "I am going to a delightful place where there is ducks, cocks, hens, bubblejacks, two dogs, two cats and swine which is delightful." In another place she says, "Braehead is extremely pleasant to me by the company of swine, geese, cocks, etc., and they are the delight of my soul." The waste of time in our public schools has been commented upon and some of the causes have been pointed out; but is not the chief reason the fact that much of the work of the school is unrelated to the world of the child? At least the child does not see the connection. He leaves at the threshold the things which he loves and desires intensely to investigate, and begins his intellectual development with abstractions, with "the three R's." It is said that teachers cannot succeed unless they love their work. How can we expect children to succeed and not waste time, not become disheartened at work that, so far as they can discover, has little more relation to their interests than to the mountains of the moon? We look to nature study to supply the missing links between the child's life and his school work; to afford opportunities for the interested observation of things, and to furnish a strong impulse toward expression. It has been well said that the best result of the primary schools is the power to use correctly one's own language. The chief obstacle in the development of this power is the want of an impulse to express. What can afford a stronger tendency to describe than the attempt to report observations that have been made with interest, even with delight? IV PLAN OF STUDY Begin as soon after the first of January as possible. Assign two periods a week of from ten to twenty minutes each for bird study in the school. Continue the work during these periods until after the celebration of Bird Day in May. If no other bird is to be found, the English sparrow will answer. Place the following questions upon the blackboard:-- THE ENGLISH SPARROW How long is this bird from the tip of its beak to the end of its tail? What is the color of its head? Of its throat? Of its breast? Of the underparts of its body? Of its back? Of its wings? What is the length, shape, and color of its bill? What is the color of its legs and feet? How many toes upon each foot, and which way do they point? Does it walk, hop, or run upon the ground? Is its tail square, or notched? Is its flight even and steady, or bounding? What is the difference in appearance between the male and female? The children should be directed to answer these questions from their own observation, at the next period of study. For the lowest grades two or three questions will be enough for the first attempt, and even then the variety of answers will be surprising. No other questions should be taken until the first are answered correctly. The teacher should have an opera glass or a small field glass with which to make her own observations. It is obvious that the more glasses there are among the children, the better. It is advisable for the teacher to make short excursions with the children to the streets to assist them in answering these questions. These can be made at the close of school. As a preparation, have some crumbs or seeds scattered where the birds have been seen. Continue work with these questions until each one can give a reasonably accurate description of the appearance of the bird and of its movements. Have the older pupils write this. It will make a good language lesson. The next questions should have reference to the life and characteristics of the bird. What does it eat? Put out crumbs or scraps of meat and see if the bird will eat them. What sounds does the bird make? Does it sing? Imitate as many of its sounds as you can. Determine from its actions what its disposition is. For example--Is it courageous? Is it quarrelsome? Is it inclined to fight? Is it selfish? Frequently a single incident in a bird's life will furnish an answer to several of these questions. Two sparrows were seen attempting to take possession of the same straw. Each held firmly to his end of the straw. A regular tug of war ensued. They pulled one another about for some time on the top of an awning, and finally, becoming tired of this, they dropped the straw and furiously attacked each other. They fought with beak and claw, paying no attention to the spectators, and fell exhausted to the sidewalk, where they lay upon their backs until able to hop slowly away from each other. It was some little time before they recovered strength to fly in opposite directions, conquering and unconquered. Early in March advise the children to watch the direction of the sparrows' flight. They will discover that some of them are carrying straws or feathers or other material for nest building. Notice the position and style of these nests. Those built early in the season are always in protected places, under the eaves of houses or in holes in trees or in bird boxes. Some of those built later are in exposed places, clumsy affairs, but well thatched with straw, having an entrance on one side. This nest building may be watched during the entire season, for the English sparrow raises more broods than any other of our birds. The interpretation of the actions which indicate any of a bird's characteristics is a valuable part of the study on account of its exercise of the imagination and the reason. A plan similar to the foregoing should be followed with each bird that is studied. With almost all other birds the study will be far more interesting. The English sparrow may be considered as the A B C of birds in his appearance and in the kind of life he leads. He is therefore a good subject to begin with. But even he will be found to exhibit unexpected individuality. After a few days of this study, or at least before the spring birds begin to arrive, direct the children to try the following experiments. Scatter crumbs where they may be seen from the windows. Nail cups in the trees containing sugar and water, and others containing seeds. Nail up a bone or two, and a piece of suet as large as your two hands. This last will be relished by the birds, for it provides the kind of food most needed in cold weather. Watch carefully the birds that are attracted by the food. After feeding awhile they will become quite tame and may be closely approached. Write a description of each bird upon the plan used for the English sparrow. Encourage the children to add any observations of their own which throw light upon the habits and character of the birds, since one object of this study is the development of right feeling toward them. Among the first to arrive will probably be the blue jay, chickadee, or black-capped titmouse, and one or more of the woodpeckers. These all show individual character and are well worth studying. The blue jay by his striking appearance and outlandish voice challenges attention. He will be found to possess some gentlemanly traits. To illustrate, a number of blue jays were seen taking turns, waiting in line, to feed upon a bone where there was room for only one at a time. There was no scramble, no hurrying of the one who was eating. The blue jay is a most devoted parent, though not considered a good citizen by other birds. Contrary to the usual belief, he has a beautiful song. It is sweet and low and almost as varied as the catbird's, and can be heard only a short distance. It has a reminiscent character, as if he were thinking of past joys. The black-capped titmouse or the chickadee is noticeable for his sprightliness and cheeriness, and for his trim, tailor-made appearance. Emerson's poem worthily celebrates his brave spirit. He flits around a limb and clings to it with his head up or down, with his feet up or down, as if his movements were not physical exertions, but mental efforts. His simple little song rings out at all hours of the coldest day. The woodpecker gives himself freely to study. One winter we frequently counted from twelve to fourteen children standing under the tree on which a little sapsucker was at work. The upturned faces of the children did not disturb him at all, although he was only a little above their heads. He drilled away as if his work in the world was the work which must be done. A downy woodpecker with a slightly wounded wing was brought into one of our schoolrooms, where he lived contentedly for several days, pecking a dead treetop, which the boys brought in for him after a good deal of thought and several excursions. The only food he seemed to like was sweetened water, although the children brought him a great variety to choose from. No visitor to a schoolroom ever produced a better effect. His presence, instead of interfering with the regular order, pleased the children, and they did their work even better than usual. When his wing was healed he was dismissed from school through the window, and his flight to a neighboring treetop was anxiously watched. Upon many other occasions wounded birds have been brought into our schools. Some recovered and others died, but each visit was an epoch in the life of the school. The other birds most likely to visit this feast during January are the flicker, crow, purple finch, song sparrow, white-breasted nuthatch, snow-flake; American crossbill, white-throated sparrow, tree sparrow, junco, winter wren, golden-crowned kinglet, brown creeper, and even the solitary robin. The sparrow hawk and the sharp-shinned hawk may visit the vicinity to feed upon the other feeders. On the first of January I saw a sparrow hawk sitting on the spire of a church in the heart of a city of eighteen thousand people. After selecting a victim from the sparrows on the street below, he calmly spread his wings and pounced upon him, or with no effort at concealment chased the bird whose flight was nearest. A female sparrow hawk wintered in the eaves of an apartment house in Morningside Park, New York City. English sparrow was its principal diet, and every morning and afternoon an observer might have seen the hawk soar to the park grounds on its hunting trips. A few years ago a sharp-shinned hawk visited our yard. Apparently he lived upon the sparrows there for several days. There was no skill in his hunting or effort to take the game unawares. When he wanted a bird he simply left his perch and captured it by speed of wing. His ease of flight was remarkable; as a little boy said, "He just opened his wings and sailed away." He stayed until the sparrows left the neighborhood. As the season advances the birds will come in greater numbers. On the first of April a little girl in one of our schools had identified and described seventeen different species of birds which she had seen in her yard. The same child fed a family of chipping sparrows; they became so tame that they would come to meet her when she came with crumbs, and would pick them up even when they dropped close to her feet. The next year this family evidently came again and raised another brood and brought them along to be fed, for seven and sometimes eight would come when she called. The English sparrow came also, and the little maid drove them away without the chippies being disturbed. A boy from one of our schools was even more fortunate. In his yard were a number of trees in which ample provision had been made for the birds. Late in April, with other kinds a pair of scarlet tanagers and a pair of rose-breasted grosbeaks visited the trees. These stayed and soon seemed to feel quite at home. To the great delight of their neighbors, the house-dwellers, they built their nests, the grosbeaks in a tree near one side of the porch, the tanagers in one near the opposite side. They became so friendly that sometimes when the boy came out upon the porch and played softly on a mouth organ, the grosbeak's silvery warble and the tanager's loud, clear voice joined him. Brief written descriptions should be made by the pupils, similar to the following:-- BLUEBIRD.--Length, six and a half inches; extent of wings, about twelve inches; color, back, azure blue; throat, breast, and sides, dull crimson; underpart, white; bill and legs, blackish; eye, brown; arrives early in March; leaves in late November. Song, soft and pleasing warble; sings both in flight and at rest; nests in holes of trees or posts, or in bird houses. CHICKADEE.--Length, about five and a half inches; extent of wings, about eight inches; legs, bluish gray; bill, black; back, brownish gray; throat, chin, and top of head, black; sides of head, white; underparts, whitish; wing and tail feathers margined with white; nests in holes in trees and stumps. The common name arises from their familiar note of "chic-a-dee-dee." CATBIRD.--Length, nine inches; extent of wings, eleven and a half inches; bill and feet, black; eye, brown; color, slate color, somewhat lighter beneath; top of head and tail, black; reddish under the wings; arrives in May, leaves in October; nests in bushes; lives in gardens and woodside thickets; has a sharp cry not unlike the mewing of a cat, but is a gifted songster. MEADOW LARK.--Length, about ten and a half inches; extent of wings, about sixteen and a half inches; female is smaller; body, thick and stout; legs, large; hind toe reaches out beyond the tail, its claw twice as long as the middle one; bill, brown, lighter at the base, dark towards the point; feet and legs, light brown; throat, breast, and edge of wing, bright yellow; breast with a large black crescent; nests on the ground in the open field; clumsy in flight and in walking; song, a plaintive whistle; arrives in March, leaves in October. BARN SWALLOW.--Length, six and three fourths inches; spread of wings, twelve and a half inches; bill, black; legs and feet, light brown; color, upper parts glossy steel blue; tail, very deeply forked, outer tail feathers much longer and narrower than the others; forehead, chin, and throat, deep chestnut; rest of the underparts lighter; nests usually in barns. WOOD THRUSH.--Length, eight inches; spread of wings, thirteen inches; legs and feet, flesh-colored; bill, blackish, lighter at base; upper parts cinnamon brown, brightest on top of the head, and shading into olive near the tail; lower parts white and marked with roundish, dusky spots; arrives the first of May, leaves in October. Song consists of sweet, ringing, bell-like notes. Later these outlines should be expanded into free descriptions, containing all that the pupil has learned about the bird, his habits, his character, and his life. Each school should aim to possess a bird manual, for the identification of the species. The following are recommended as sufficient for the purpose: "Birds of the United States," by A. C. Apgar; "Birds of Eastern North America," by Frank M. Chapman; "Bird Craft," by Mabel Osgood Wright; "Birds of Pennsylvania," second edition, by Warren (this may possibly be obtained at second-hand bookstores); "Our Common Birds and How to Know Them," by Grant. The report of your own state upon birds, if there is one, will also furnish valuable information. V FURTHER SUGGESTIONS Direct the children to put up boxes for martins, bluebirds, and wrens. These may be also put up around the schoolhouses, if fortunately there is a yard with trees. Boxes for the martins should be large, containing fifteen or more compartments, each ten inches high by eight wide and eight deep, and each having a separate entrance. The martin box or house should be placed twenty feet from the ground, upon the top of a strong post or platform sustained by four smaller posts. If vines are planted at the foot of the supports, they will be ornamental and will make the houses more attractive to the birds. The English sparrows will occupy these compartments; but if the martins conclude to take possession they will push out the sparrows and their belongings without assistance. Every spring I am amused in watching the summary process of ejectment which the martins serve upon the sparrows that have taken possession of their houses. In the morning the sparrows may be in undisturbed possession, but by afternoon the martins occupy their old quarters, having pushed out the nests of the sparrows with their eggs or young. The boxes for bluebirds and wrens should be smaller and have only one compartment. They should be nailed in the tops of trees. If the English sparrows build in them their nests should be broken up; and this repeatedly, so long as they persist in building. If this is not done the wrens and bluebirds will not come. They are incapable of coping with the sparrows. Note when the different birds arrive in the spring, making in this way a bird calendar. Notice also when the birds gather together into flocks in the late summer or autumn, preparatory to taking their leave. The last bird of his kind to leave should be as carefully noted as the first to arrive in your calendar. Distinguish carefully the birds of passage that stop only a short time to rest on their journeys north and south, and those that stay and help to make the summer. You will need to make frequent excursions afield, always taking your notebook. Take first a small area and master the birds in that; then gradually extend your territory. You can take no more healthful or happy exercise. It will greatly increase the interest of children in all their school duties if their teachers make occasional bird journeys with them. Limit the size of the party to that number which will keep still as a mouse while in bird-land. Encourage the children also to make frequent excursions by themselves, in parties of three or four. Instruct them to have the sun at their backs and to carry if possible one glass with each party. Reports of these excursions can be made in school, while particular attention should be given to the exchange of the knowledge of bird haunts. This can be done during the period devoted to bird study. Direct the party of excursionists to observe the same birds, notebook in hand, and let each one immediately put down what he actually sees. Afterward compare results. In this way improvement will be made in rapidity and accuracy of observing. There are two ways by which birds may be closely approached. The first is to go to some locality where birds have been seen and to stand or sit in perfect quiet and wait for them to come. We have known some of the shyest wood birds to come within a few feet of the motionless observer. It is not an uncommon thing for one who waits to be able to look directly into the eyes of the American redstart, the chestnut-sided and golden-winged warbler, the wood thrush, catbird, and of almost any other of the birds. If one can imitate the owl and make a fair "hoot," otherwise keeping still, he may attract many birds that will feel bound to settle the question of his identity. A young friend of mine, by a good imitation of a blue jay's quack, finds many little woods' folks peering at him from the trees which he might not otherwise see. The "smack" which is produced by violently kissing the back of the closed fingers will call many birds from their hiding places, especially during the nesting season. The sound is similar to that of a bird in distress. The second method is to follow a bird very quietly and slowly, being careful not to make any motions which would startle him. In this way a shore lark has been followed all over a field, the observer gradually coming near enough to the bird to see what he was doing, and to watch his movements as he pulled the larvæ of beetles out of the ground, cracked their cases, and ate the contents. All birds that feed in the fields, the meadow larks, the plovers, and the sparrows, may be studied in the same way. It is commonly thought to be difficult to get close to the veery. On one occasion, while the writer and a companion were resting from a long ramble, the air was suddenly suffused with the songs of veeries. The music seemed to fill the woods, as an organ seems to fill the church with sound. It was weird and suggestive and never to be forgotten. The still, deep woods seemed like enchanted ground where nothing evil could come. After some search we saw one of the birds in a tree not far from us. As we approached him he flew to another tree. We humbly followed on foot from tree to tree, when to our surprise he stopped on a low tree on the outskirts of the wood and allowed us to come almost within reach of him, and to stand wonder-stricken while he sang in answer to his companions. We stayed for twenty minutes motionless. It was difficult to believe that this bird was singing. His notes had a ventriloquous effect, his beak was scarcely parted, and it was only by the trembling of the feathers of his throat that we were sure the song came from him. Since this time we have frequently found the veeries; in fact one locality is known to us as Veeryville. It is not necessary to live in the country in order to be a bird student and to carry out the suggestions here given. All the large cities have parks where birds may be observed and be encouraged to become friendly to the observer. Central Park in New York is the home of a great variety of birds. Bronx Park is said to be a paradise for them. On Boston Common most of the birds which come to that latitude have been seen. There is no city so poor that it cannot boast of a few birds in its vicinity. Great interest and delight may be added to the study of birds by the use of the camera. If the teacher or one of the older pupils is so fortunate as to have a kodak and will take it when visiting the woods, or will focus it upon birds in the dooryard, the pictures may possess much value. To attempt to "take" a bird in flight is, of course, a difficult matter, though it may be done; but birds upon the nest, birds feeding their young, or in the trees above the nest, evidently protecting it, have been successfully taken. Birds' nests with the eggs in make most fascinating pictures. At an entertainment given by the Pennsylvania Audubon Society in Philadelphia in December, 1898, the audience with one accord cheered the picture of a nest which was thrown upon a screen. Work of this kind is especially adapted for high schools, and there are sure to be several painstaking amateurs among the pupils. To possess genuine value from the point of view of the naturalist, the pictures should not be touched up, no matter how much artistic beauty might thus be given to them; they should be entirely true to nature. On no account should children be encouraged to make collections of birds or of eggs. The only objection the author has felt to the very fine bird manuals before the public is that they contain minute directions for the preparation of dead birds for purposes of mounting and preservation, and also for the collection and preservation of birds' eggs. If this were to cause the school children of the country to set out to make collections of birds and of eggs in order to study them, the study would better be omitted. Nothing more deadly than an opera glass should be aimed at a bird for a generation. The utility of a collection is not so great; a dead bird's plumage is not as beautiful as in life, and he loses every attitude and movement which makes him an individual. A corpse is not a bird. Persons who can identify birds by one glimpse of them through the trees, or by a few notes of their song, or by their flight are frequently at a loss to identify the same birds when they are dead, unless they are familiar with the dead birds. The only collection the children should be encouraged to make is that of nests after the birds are through with them; and especially of nests with whose family history they are acquainted. These may be brought into the schoolroom. In one of our school yards the children discovered a pair of red-eyed vireos building. The nest was so situated that it could be seen from one of the upper schoolroom windows. After the young had left, the nest was taken down, and to the pleasure which the children had enjoyed in watching its builders and their family was added another. They found in the bottom of the nest little bits of the papers they had used in school with their letters and figures upon them. VI DIRECTIONS FOR WRITTEN WORK Have the children give anecdotes about birds that they have observed. Let them describe actions which they saw them perform, paying particular attention to the ways of birds in eating. For example, sparrows were observed carrying hard crusts of bread to a little pool of water, formed in a dent in a tin roof, to soften before attempting to eat them. Day after day crusts were put out, and the water was renewed. _Written descriptions of birds feeding their young._--Young birds live entirely upon insect life. It has been computed that a bird during the first few weeks of its life consumes nearly one and one half times its weight of insects daily. Note the amazing amount of insect life that will be destroyed by the birds of a neighborhood in a single season. Give, if possible, illustrations from your own observation. A robin was noticed feeding one of its young, which sat on a limb with its mouth open, crying for more, except when it was stopped with food. The parent came with her beak filled with worms twenty-seven times in less than as many minutes, and then left her child seemingly as hungry as ever, for he complained and hopped along the limb, keeping a sharp lookout for several minutes. That chick must have been as full of worms as a fisherman's bait-box. Picture the condition of our lawns, gardens, and groves if all the birds were suddenly banished and the insects held full sway. In this connection, the writer should study and make quotations or abstracts from "The Birds of Killingworth," by Longfellow. In a recent lecture, Prof. Witmer Stone, of Philadelphia, cited many facts to show that birds are nature's great check on the excess of insects, and that they keep the balance between plants and insect life. Ten thousand caterpillars, it has been estimated, could destroy every blade of grass on an acre of cultivated ground. In thirty days from the time it is hatched an ordinary caterpillar increases 10,000 times in bulk, and the food it lives and grows on is vegetable. The insect population of a single cherry tree infested with aphides was calculated by a prominent entomologist at no less than twelve million. The bird population of cultivated country districts has been estimated at from seven hundred to one thousand per square mile. This is small compared with the number of insects, yet as each bird consumes hundreds of insects every day, the latter are prevented from becoming the scourge they would be but for their feathered enemies. Mr. E. H. Forbush, Ornithologist of the Board of Agriculture of Massachusetts, states that the stomachs of four chickadees contained 1,028 eggs of the cankerworm. The stomachs of four other birds of the same species contained about 600 eggs and 105 female moths of the cankerworm. The average number of eggs found in twenty of these moths was 185; and as it is estimated that a chickadee may eat thirty female cankerworm moths per day during the twenty-five days which these moths crawl up trees, it follows that in this period each chickadee would destroy 138,750 eggs of this noxious insect. A pamphlet issued by the Department of Agriculture of the United States says that the cuckoo, which is common in all the Eastern States, has been conclusively shown to be much given to eating caterpillars, and, unlike most birds, does not reject those that are covered with hair. In fact, cuckoos eat so many hairy caterpillars that the hairs pierce the inner lining of their stomach and remain there, so that when the stomach is opened and turned inside out, it appears to be lined with a thin coating of hair. This bird also eats beetles, grasshoppers, sawflies, and spiders. It turns out from the investigations of the department that the suspicion with which all farmers look upon woodpeckers is undeserved by that bird. These birds rarely leave an important mark upon a healthy tree, but when a tree is affected by wood-boring larvæ the insects are accurately located, dislodged, and devoured. In case the holes from which the borers are taken are afterward occupied and enlarged by colonies of ants, these ants are drawn out and eaten. Woodpeckers are great conservators of forests, and to them more than to any other agency is due the preservation of timber from hordes of destructive insects. The department defends the much-abused crow and states that he is not by any means the enemy of the farmer, in which rôle he is generally represented. The pamphlet shows that he is known to eat frogs, toads, salamanders, and some small snakes, and that he devours May beetles, June bugs, grasshoppers, and a large variety of other destructive insects. It is admitted that he does some damage to sprouting corn, but this can be prevented by tarring the seed, which not only saves the corn, but forces the crow to turn his attention to insects. _Insects injurious to vegetation._--Essays may be written describing some of the insects injurious to fruit trees; also the birds that feed largely upon these insects--the warblers, thrushes, orioles, wrens, woodpeckers, vireos, and others. Tell, if possible, from your own observation, of their curious, but effective, ways of finding their food. Describe how the birds inspect the trees, limb by limb and bud by bud, in their eager search for the eggs, larvæ, and mature forms of insects. Note, especially, the oriole as he runs spirally round a branch to the very tip, then back to the trunk, treating branch after branch in the same way, till the whole tree has been thoroughly searched, almost every bud having been in the focus of those bright eyes. It is hard to describe which is the more beautiful--their brilliant, flaming colors or their bugle-like bursts of music. Is the woodpecker's drumming, and apparent listening with the side of his head turned to the tree, all for fun, and nothing for reward? _Birds that feed upon the potato beetle._--The grosbeaks and the tanagers. Describe these. Why are these and other brightly colored birds so shy? What has been the effect of the extensive killing of them for ornament, and the equally cruel practice of securing their young to be kept in cages? Note how much more attractive our fields and gardens would be if these beautiful beings were common in them, and by their quaint ways were "teaching us manners." _Personations of birds._--Ask the children to write "personations" of birds, as if the writer were the bird. Give them the following directions: Write in the first person. Describe yourself as accurately as you are able, without telling your name. Tell of your habits and manner of life, your summer and winter homes, your home cares--your nest building, your parental joys and anxieties, the enemies you have to avoid. Mention at some length the trouble you take to give your little ones a good start in life, and to enable them to earn their own living. Describe your songs, and try to indicate why they differ, and what you mean by each one. Try to present a somewhat complete picture of the bird and its life, from the bird's point of view. At the close of your personation the hearers may vote upon the name of the bird presented. A family of birds may also be described, as if they were persons,--and are they not? A very fine model of this kind of work is "Our New Neighbors at Ponkapog," by T. B. Aldrich. Have essays written upon the following subjects:-- Are there birds that do not sing? What is the attitude of other birds to the owl? Is any country too cold, or any too warm, for birds? Have birds individuality? What is the largest bird of North America? The smallest? What laws has your state made about birds? Ought the "government to own" the birds? (That is, make laws for their protection.) Is the blue jay wicked? What birds walk? Do birds travel at night, during their migrations? Beginning in March, note for several days the different kinds of birds you see, which were not seen the day before. Make at least two observations daily, one in the morning and one after school. When is the greater number of new birds seen, in the morning or in the afternoon? Or, if you live in a comparatively quiet neighborhood, even in a large city, go out at night and listen for bird sounds in the air. You need not go far to make this trial--your own back door "opens into all outdoors." What states have established a Bird Day by law? Is woman cruel or only thoughtless? Do robins raise more than one brood in a season? If so, do they use the same nest twice? If they raise two broods, what becomes of the first, while the mother is sitting upon the eggs for the second? Watch for a robin leading out his family. Notice the feeding, after the birds are large enough to run and fly fairly well. The young birds are placed apart, and kept apart by the parent, who visits each one in turn, and rebukes any who tries to be piggish, sometimes rapping it with his bill when it runs out of turn. Notice this parent teaching the young to sing. It is a very interesting sight. What birds have you heard sing at night? More birds sing at night than is commonly supposed. The female robin calls to her mate frequently during the night, and he responds with a song. The catbird also sings at night. Last May one was heard to sing three nights in succession from eleven o'clock until daylight in response to little complaining calls from his mate. The song sparrow, warblers, and many other birds sing at night. Their songs at these times sound as if the bird were sleepy and reluctant to sing, or as if he were startled and were hurrying through the performance. Make a note of songs heard at night and try to determine the cause. Learn to distinguish the call of the female from the song of the male. _The kinds of nests._--What birds are weavers? What ones are masons or plasterers? What ones are tailors, in the construction of their nests? Find a pair of birds engaged in nest building; robins may generally be found. Learn to distinguish the male from the female in appearance, as well as voice. Notice what materials they are using. Which bird takes the lead in building? What does the other bird do? Does he ever carry material, or does he simply act as escort? Does he ever protect his mate from other birds? Write this out, carefully drawing your conclusions from your own observations. After the young birds have left the nest and have no further use for it, you may take the nest and examine it closely. You will find that while there is a similarity in the nests of the same kind of birds, they differ considerably in the materials of which they are composed. For example, the typical robin's nest consists of straws and hairs plastered together with mud and lined with some soft material, but others have been found made entirely of raveled rope; others of carpet rags. The bird evidently is not guided in this matter by blind instinct, but uses its reason in adapting materials that are at hand. If you are fortunate you may find a pair of orioles building their nest. Place some bright-colored yarn or string in pieces of convenient length where the birds will see them. Some of them are almost sure to be woven into the nest. The oriole's nest may be attached to a limb by two or more cords; if it is, notice how it is prevented from swinging by side ropes. You will find it guyed against the prevailing winds. The oriole frequently ties several twigs together, and so uses these to suspend his nest. Notice the nest pouch; those built near houses are quite shallow; those near forests are much deeper. Can you tell why? _The wings of birds._--Describe the different kinds, as short and round, or long and slender, and the effect of the wing-shape upon the bird's motion in the air. Describe the flights of different birds. _Songs of birds._--Write the syllables which seem to you to express the different songs of birds. Notice the different songs of the same bird. A song sparrow was observed to have twelve different songs. He sang each one several times over, as if each song had a number of verses. Then changing his position, he would sing another. To most ears the robin's song is always the same, but close attention discovers that there are variations. Many birds are genuine musicians and compose as they sing, not having formal songs. _Free description of birds._--Write description of some bird of your acquaintance, noting the following:-- _Its appearance._--Color, gait, flight, size from tip of beak to end of tail, spread of wings. _Its common name._--Why given? _Time of arrival and departure._ _Character._--Is it trustful, or shy and retiring? _Song._--Season when song is most frequent, also times of day. Does it consist of many or only a few notes? Is it cheery, like the robin's, or tuneful, like the thrush's, or rollicking and rapturous, like the bobolink's, or a Romanza, like the catbird's? Notice the different emotion sounds, the notes of fear, of parental or conjugal reprimand, of joy, of anger, of deep sorrow, made by the bird at times. _Food._--Insects (kinds), seeds, fruit, etc. _Nest._--Where placed, how made? _Incidents._--From the writer's knowledge of the bird. _This bird in literature._--What writers have described, what poets have immortalized him? How did they characterize him? Some of the following books are almost indispensable to one who wishes to know the birds:-- "Wake Robin," John Burroughs; "Birds and Poets," John Burroughs; "The Birds and Seasons of New England," Wilson Flagg; "Upland and Meadow," Charles C. Abbott; "Bird Ways," Olive Thorne Miller; "Birds through an Opera Glass," Florence A. Merriam; "Birds in the Bush," Bradford Torrey; "The Birds About Us," Charles C. Abbott; "From Blomidon to Smoky," Frank Bolles. Recent magazines should be searched and the current ones scrutinized for articles by any of the above-named writers. _Destruction of birds._--Find out how many birds are annually slaughtered in the United States, and for what purposes. In the report of the American Ornithologist Union published in 1886, it was estimated that about five million birds were annually required to fill the demand for the ornamentation of the hats of the American women. In 1896 it was estimated that the number thus used was ten million. "The slaughter is not confined to song-birds; everything that wears feathers is a target for the bird butcher. The destruction of 40,000 terns in a single season on Cape Cod, a million rail and reed birds (bobolinks) killed in a single month near Philadelphia, are facts that may well furnish food for reflection. The swamps and marshes of Florida are well known to have become depopulated of their egrets and herons, while the state at large has been for years a favorite slaughter ground of the milliners' emissaries." An article in _Forest and Stream_, speaking of the destruction of birds on Long Island, states that during a short period of four months 20,000 were supplied to the New York dealers from a single village. The Audubon Society of Massachusetts has looked up the figures and reports that "it is proved that into England alone between 25,000,000 and 30,000,000 birds are imported yearly, and that for Europe the number reaches 150,000,000. Hence, the fashionable craze has annually demanded between 200,000,000 and 300,000,000 birds. From the East Indies alone a dealer in London received 400,000 humming birds, 6,000 birds of paradise, and 400,000 miscellaneous birds. In an auction room, also in London, within four months, over 800,000 East and West Indian and Brazilian bird skins, besides thousands of pheasants and birds of paradise, were put up for sale." This demand for birds has been going on for a quarter of a century, and billions of rich-plumaged creatures have been slaughtered to meet it, and several of the feathered tribes have been exterminated. Write to the following for literature upon the destruction of birds:-- Humane Education Committee, 61 Westminster Street, Providence, R. I.; George T. Angell, Boston, Mass.; Secretary of the Massachusetts Audubon Society, Boston, Mass.; Secretary of the New York Audubon Society at New York; Secretary of the Department of Agriculture, Washington, D. C.; Secretary of the Audubon Society of Pennsylvania at Philadelphia; also write to the Department of Agriculture of your own state. VII PROGRAMS FOR BIRD DAY A Bird Day exercise, in order to have much value educationally, should be largely the result of the pupils' previous work, and should not be the mere repetition of a prepared program taken verbatim from some paper or leaflet. It is, of course, better to have the pupils recite this leaflet or list of statements than it would be to have it ground out of a phonograph. The program should be prepared by the pupils under direction of the teacher. The following general suggestions are offered:-- 1. For the first observance of this day by a school it would be well to have some pupil read Senator Hoar's petition of the birds to the Legislature of Massachusetts. PETITION OF THE BIRDS _Written by Senator Hoar to the Massachusetts Legislature_ The petition which was instrumental in getting the Massachusetts law passed, prohibiting the wearing of song and insectivorous birds on women's hats, was written by Senator Hoar. The petition read as follows:-- To the Great and General Court of the Commonwealth of Massachusetts: We, the song birds of Massachusetts and their playfellows, make this our humble petition. We know more about you than you think we do. We know how good you are. We have hopped about the roofs and looked in at your windows of the houses you have built for poor and sick and hungry people, and little lame and deaf and blind children. We have built our nests in the trees and sung many a song as we flew about the gardens and parks you have made so beautiful for your children, especially your poor children to play in. Every year we fly a great way over the country, keeping all the time where the sun is bright and warm. And we know that whenever you do anything the other people all over this great land between the seas and the Great Lakes find it out, and pretty soon will try to do the same. We know. We know. We are Americans just the same as you are. Some of us, like you, came across the great sea. But most of the birds like us have lived here a long while; and the birds like us welcomed your fathers when they came here many, many years ago. Our fathers and mothers have always done their best to please your fathers and mothers. Now we have a sad story to tell you. Thoughtless or bad people are trying to destroy us. They kill us because our feathers are beautiful. Even pretty and sweet girls, who we should think would be our best friends, kill our brothers and children so that they may wear our plumage on their hats. Sometimes people kill us for mere wantonness. Cruel boys destroy our nests and steal our eggs and our young ones. People with guns and snares lie in wait to kill us; as if the place for a bird were not in the sky, alive, but in a shop window or in a glass case. If this goes on much longer all our song birds will be gone. Already we are told in some other countries that used to be full of birds, they are now almost gone. Even the nightingales are being killed in Italy. Now we humbly pray that you will stop all this and will save us from this sad fate. You have already made a law that no one shall kill a harmless song bird or destroy our nests or our eggs. Will you please make another one that no one shall wear our feathers, so that no one shall kill us to get them? We want them all ourselves. Your pretty girls are pretty enough without them. We are told that it is as easy for you to do it as for a blackbird to whistle. If you will, we know how to pay you a hundred times over. We will teach your children to keep themselves clean and neat. We will show them how to live together in peace and love and to agree as we do in our nests. We will build pretty houses which you will like to see. We will play about your garden and flower beds--ourselves like flowers on wings, without any cost to you. We will destroy the wicked insects and worms that spoil your cherries and currants and plums and apples and roses. We will give you our best songs, and make the spring more beautiful and the summer sweeter to you. Every June morning when you go out into the field, oriole and bluebird and blackbird and bobolink will fly after you and make the day more delightful to you. And when you go home tired after sundown, vesper sparrow will tell you how grateful we are. When you sit down on your porch after dark, fifebird and hermit thrush and wood thrush will sing to you; and even whip-poor-will will cheer you up a little. We know where we are safe. In a little while all the birds will come to live in Massachusetts again, and everybody who loves music will like to make a summer home with you. The signers are:-- Brown Thrasher, Robert o' Lincoln, Hermit Thrush, Vesper Sparrow, Robin Redbreast, Song Sparrow, Scarlet Tanager, Summer Redbird, Blue Heron, Humming Bird, Yellowbird, Whip-poor-will, Water Wagtail, Woodpecker, Pigeon Woodpecker, Indigo Bird, Yellowthroat, Wilson's Thrush, Chickadee, Kingbird, Swallow, Cedar Bird, Cowbird, Martin, Veery, Chewink, Vireo, Oriole, Blackbird, Fifebird, Wren, Linnet, Pewee, Phoebe, Yoke Bird, Lark, Sandpiper. It should be noted that the result of this petition was the passage of a law by the Legislature of Massachusetts forbidding the wearing of parts of wild birds. A bill forbidding the transportation of feathers or the skins of birds from one state to another was also introduced by Senator Hoar in the United States Senate. 2. At this first exercise it would be well to have read "Our New Neighbors at Ponkapog," by T. B. Aldrich. 3. The best essays that have been written by the pupils during their preliminary study may be given. If the school has not made this preliminary study, select subjects and have essays written according to the directions already given, allowing as much time as possible for original observations. 4. Have recitations from the poets. These will add a peculiar charm to the occasion. A short list of suitable poems will be given. Many others may be found in a book called "Voices of the Speechless," published by Houghton, Mifflin & Co. The works of John Burroughs, Bradford Torrey, Maurice Thompson, Mrs. Olive Thorne Miller, and Dr. C. C. Abbott abound in passages which are excellent for recitation. It is surprising how familiar the best-known novelists have been and are with birds. In appreciation of them they are second only to the poets. Charles Reade's description of the lark's song in the mines of Australia, in "Never Too Late to Mend," is an inspiring recitation. 5. Short quotations from well known authors should be given, if possible, by every pupil in the school. We give a few taken almost at random:-- Away over the hayfield the lark floated in the blue, making the air quiver with his singing; the robin, perched on a fence, looked at us saucily and piped a few notes by way of remark; the blackbird was heard, flute-throated, down in the hollow recesses of the wood; and the thrush, in a holly tree by the wayside, sang out his sweet, clear song that seemed to rise in strength as the wind awoke a sudden rustling through the long woods of birch and oak.--WILLIAM BLACK, in _Adventures of a Phaeton_. We seemed to hear all the sounds within a great compass--in the hedges and in the roadside trees, far away in woods or hidden up in the level grayness of the clouds: twi, twi, trrrr-weet!--droom, droom, phloee!--tuck, tuck, tuck, tuck, feer!--that was the silvery chorus from thousands of throats. It seemed to us that all the fields and hedges had but one voice, and that it was clear and sweet and piercing.--WILLIAM BLACK, _Ibid._ Silvia could hear the twittering of the young starlings in their nests as their parents went and came carrying food, and the loud and joyful "tirr-a-wee, tirr-a-wee, prooit, tweet!" of the thrushes, and the low currooing of the wood pigeon, and the soft call of the cuckoo, that seemed to come in whenever an interval of silence fitted. The swallows dipped and flashed and circled over the bosom of the lake. There were blackbirds eagerly but cautiously at work, with their spasmodic trippings, on the lawn. A robin perched on the iron railing eyed her curiously and seemed more disposed to approach than to retreat.--WILLIAM BLACK, in _Green Pastures and Piccadilly_. A jay fled screaming through the wood, just one brief glimpse of brilliant blue being visible.--WILLIAM BLACK, _Ibid._ And as they came near to one dark patch of shrubbery, lo! the strange silence was burst asunder by the rich, full song of a nightingale.--WILLIAM BLACK, _Ibid._ A sudden sound sprang into the night, flooding all its darkness with its rich and piercing melody--a joyous, clear, full-throated note, deep-gurgling now, and again rising with thrills and tremors into bursts of far-reaching silver song that seemed to shake the hollow air. A single nightingale had filled the woods with life. We cared no more for those distant and silent stars. It was enough to sit here in the gracious quiet and listen to the eager tremulous outpouring of this honeyed sound.--WILLIAM BLACK, in _Strange Adventures of a House-Boat_. Shoot and eat my birds! The next step beyond, and one would hanker after Jenny Lind or Miss Kellogg.--HENRY WARD BEECHER. There on the very topmost twig, that rises and falls with willowy motion, sits that ridiculous, sweet-singing bobolink, singing as a Roman candle fizzes, showers of sparkling notes.--_Ibid._ This poet affirms that our bobolink is superior to the nightingale:-- Bobolink, that in the meadow, Or beneath the orchard's shadow, Keepest up a constant rattle Joyous as my children's prattle, Welcome to the North again, Welcome to mine ear thy strain, Welcome to mine eye the sight Of thy buff, thy black and white. Brighter plumes may greet the sun By the banks of Amazon; Sweeter tones may weave the spell Of enchanting Philomel; But the tropic bird would fail, And the English nightingale, If we should compare their worth With thine endless, gushing mirth. --THOMAS HILL. The mocking bird is a singer that has suffered much from its powers of mimicry. On ordinary occasions, and especially in the daytime, it insists on playing the harlequin. But when free in its own favorite haunts at night, it has a song, or rather songs, which are not only purely original, but are also more beautiful than any other bird music whatsoever. Once I listened to a mocking bird singing the livelong spring night, under the full moon, in a magnolia tree; and I do not think I shall ever forget its song. The great tree was bathed in a flood of shining silver; I could see each twig, and mark every action of the singer, who was pouring forth such a rapture of ringing melody as I have never listened to before or since. Sometimes he would perch motionless for many minutes, his body quivering and thrilling with the outpour of music. Then he would drop softly from twig to twig till the lowest limb was reached, when he would rise, fluttering and leaping through the branches, his song never ceasing for an instant until he reached the summit of the tree and launched into the warm scent-laden air, floating in spirals, with outspread wings, until, as if spent, he sank gently back into the tree and down through the branches, while his song rose into an ecstasy of ardor and passion. His voice rang like a clarionet in rich, full tones, and his execution covered the widest possible compass; theme followed theme, a torrent of music, a swelling tide of harmony, in which scarcely any two bars were alike. I stayed till midnight listening to him; he was singing when I went to sleep; he was still singing when I woke a couple of hours later; he sang through the livelong night.--THEODORE ROOSEVELT. Amid the thunders of Sinai God uttered the rights of cattle, and said that they should have a Sabbath. "Thou shalt not do any work, thou, nor thy cattle." He declared with infinite emphasis that the ox on the threshing-floor should have the privilege of eating some of the grain as he trod it out, and muzzling was forbidden. If young birds were taken from the nest for food, the despoiler's life depended on the mother going free. God would not let the mother-bird suffer in one day the loss of her young and her own liberty. And he who regarded in olden time the conduct of man toward the brutes, to-day looks down from heaven and is interested in every minnow that swims the stream, and every rook that cleaves the air.--DEWITT TALMAGE, D.D. And how refreshing is the sight of the birdless bonnet! The face beneath, no matter how plain it may be, seems to possess a gentle charm. She might have had birds, this woman, for they are cheap enough and plentiful enough, heaven knows; but she has them not, therefore she must wear within things infinitely precious, namely, good sense, good taste, good feeling. Does any woman imagine these withered corpses (cured with arsenic), which she loves to carry about, are beautiful? Not so; the birds lost their beauty with their lives.--CELIA THAXTER. I walked up my garden path as I was coming home from shooting. My dog ran on before me; suddenly he went slower and crept carefully forward as if he scented game. I looked along the path and perceived a young sparrow, with its downy head and yellow bill. It had fallen from a nest (the wind was blowing hard through the young birch trees beside the path) and was sprawling motionless, helpless, on the ground, with its little wings outspread. My dog crept softly up to it, when suddenly an old black-breasted sparrow threw himself down from a neighboring tree and let himself fall like a stone directly under the dog's nose, and, with ruffled feathers, sprang with a terrified twitter several times against his open, threatening mouth. He had flown down to protect his young at the sacrifice of himself. His little body trembled all over, his cry was hoarse, he was frightened to death; but he sacrificed himself. My dog must have seemed to him a gigantic monster, but for all that, he could not stay on his high, safe branch. A power stronger than himself drove him down. My dog stopped and drew back; it seemed as if he, too, respected this power. I hastened to call back the amazed dog, and reverently withdrew. Yes, don't laugh; I felt a reverence for this little hero of a bird, with his paternal love. Love, thought I, is mightier than death and the fear of death; love alone inspires and is the life of all.--IVAN TOURGUENEFF. The first sparrow of spring! The year beginning with younger hope than ever! The faint, silvery warblings heard over the partially bare and moist fields from the bluebird, the song sparrow, and the redwing, as if the last flakes of winter tinkled as they fell!--H. D. THOREAU. I heard a robin in the distance, the first I had heard for many a thousand years, methought, whose note I shall not forget for many a thousand more,--the same sweet, powerful song as of yore.--_Ibid._ Walden is melting apace. A great field of ice has cracked off from the main body. I hear a song sparrow from the bushes on the shore,--_olit, olit, olit--chip, chip, chip, che char--che wis, wis, wis_. He, too, is helping to crack the ice.--_Ibid._ The bluebird carries the sky on his back.--_Ibid._ 6. One of the most interesting features of a Bird Day program will be the personations of birds. The following was given by a boy in the seventh grade:-- One day in February a gentleman and his wife stopped beside the wall of old Fort Marion, in St. Augustine, to listen to my song. The sun was shining brightly, and little white flowers were blooming in the green turf about the old fort. It was not time yet to build my nest, so I had nothing to do but sing and get my food and travel a little every day toward my Northern home. I am about as large as a robin, and although there is nothing brilliant in my plumage I am not a homely bird. I like the songs of other birds and sometimes sing them. I frequently sing like my cousins, the catbirds and robins and thrushes. But I have my own song, which is unlike all the others. My mate and I build a large nest of small sticks, pieces of string, cotton, and weeds, in thick bushes or low trees. We have five eggs that are greenish blue and spotted with brown. We eat many beetles, larvæ, and many kinds of insects which we find feeding upon plants. The worst enemy we have is man. He steals our children almost before we have taught them to sing, and puts them in cages. He is a monster. Many poems have been written about me. One of the finest is by Sidney Lanier, in which he calls me "yon trim Shakespeare on the tree." Any one who has heard my song can never forget me. What is my name? 7. Bird facts and proverbs form a valuable part of a program and may be given by some of the children. Let the pupils search for them and bring some similar to these:-- Birds flock together in hard times. A bird in the bush is worth two in the hand. The American robin is not the same bird as the English. The bluebird and robin may be harbingers of spring, but the swallow is the harbinger of summer. The dandelion tells me to look for the swallow; the dog-toothed violet when to expect the wood thrush.--JOHN BURROUGHS. It is not thought that any one bird spends the year in one locality, but that all birds migrate, if only within a limited range. A loon was caught, by a set line for fishing, sixty-five feet below the surface of a lake in New York, having dived to that depth for a fish. The wood pewee, like its relative, the phoebe, feeds largely on the family of flies to which the house fly belongs. The birds of prey, the majority of which labor night and day to destroy the enemies of the husbandman, are unceasingly persecuted. Seventy-five per cent of the food of the downy woodpecker is insects. The cow blackbird lays its eggs in other birds' nests, one in a nest. What happens afterwards? Why should not a man love a bird? If the palm of one could clasp the pinion of the other, there would come together two of the greatest implements God and nature have ever given any two creatures to explore the world with, and when two bipeds gaze at each other, eye to eye, the intelligence in the one might well take off its hat to the subtle instincts in the other.--JAMES NEWTON BASKETT. A bird on the bonnet means so much less bread on the table. A bird in the orchard is a sort of scavenger and pomologist combined, and does his share in giving you a dish of fruit for dinner. The scarlet tanager looks like a living ruby in a green tree; but--I speak bluntly--it looks like a chunk of gore on a woman's bonnet. In behalf of good taste and the birds, I enter my protest against this barbarous Custom.--LEANDER T. KEYSER. What does it cost, this garniture of death? It costs the life which God alone can give; It costs dull silence, where was music's breath; It costs dead joy, that foolish pride may live. Ah, life, and joy, and song, depend upon it, Are costly trimmings for a woman's bonnet. --MAY RILEY SMITH. The program may be diversified by songs about birds. Many suitable for this occasion will be found in a collection called "Songs of Happy Life," made by Sarah J. Eddy. It is published by the Nature Study Publishing Company, of Providence, R. I. VIII THE POETS AND THE BIRDS "The birds are the poets' own," says Burroughs. How could it be otherwise? The bird, with his large brain, quick circulation, and high temperature, is possessed of a tropical, ecstatic soul that blossoms into music as naturally as a bulb bursts into bloom and fragrance. He is a creature of marvelous inheritance. Poetry is a true bird-land, where you shall hear the birds as often as in any meadow or orchard on a May morning. All poets have been their lovers, from the psalmist of old, who knew "all the birds of the mountains," to our own Lowell with his "Gladness on wings--the bobolink is here." The poets, who voice our deepest thoughts, have studied birds with the utmost care. It is astonishing to note the mention made of them in the pages of Browning, Tennyson, and in fact of every great maker of verse. Not merely as adjuncts of the landscape are they mentioned, but with intensity of feeling, as in William Watson's poem on his recovery from temporary loss of mind--one of the most pathetic poems ever written--where he thanks the Heavenly Power for letting him feel once again at home in nature and again related to the birds and to human life. Dr. Van Dyke's wish that, when his twilight hour is come, he "may hear the wood note of the veery" finds response in the heart of every one who has listened to that song. Frequently the poet seems to have entered into the life of the bird and to have found his inner secret, as Keats in the "Ode to a Nightingale":-- Immortal bird, thou wast not born for death, No hungry generations tread thee down. Sometimes the words seem to have caught the rhythm and ripple of the song, as in Browning's reference to the thrush:-- The wise thrush, he sings each song twice over, Lest you think he never could recapture That first fine careless rapture. Or the bird's voice may be so suggestive as to lead the seer to the very limits of thought and aspiration, like Shelley's "Skylark." As we need the help of the naturalists, who see more accurately than we, we also need the assistance of the poet's clearer vision, with its wider and deeper sweep. How completely Sidney Lanier summed up the mocking bird! and how much more pleasing is the bird in the tree because of the bird in the poem:-- Superb and sole, upon a plumèd spray That o'er the general leafage boldly grew, He summed the woods in song; or typic drew The watch of hungry hawks, the lone dismay Of languid doves when long their lovers stray, And all birds' passion plays that sprinkle dew At morn in brake or bosky avenue. Whate'er birds did or dreamed, this bird could say. Then down he shot, bounced airily along The sward, twitched in a grasshopper, made song Midflight, perched, prinked, and to his art again. Sweet science, this large riddle read me plain:-- How may the death of that dull insect be The life of yon trim Shakespeare on the tree? Recitations from the poets should be a prominent feature of Bird Day exercises. Readings and studies of poems about birds may be very profitably made a part of the literary work of the year. The following poems are suitable for recitation and study:-- "The Birds' Orchestra," Celia Thaxter; "The Robin," Celia Thaxter; "The Song Sparrow," Celia Thaxter; "The Blackbird," Alice Cary; "The Raven's Shadow," William Watson; "On Seeing a Wild Bird," Alice Cary; "What Sees the Owl?" Elizabeth S. Bates; "Lament of a Mocking Bird," Frances Anne Kemble; "The Snow-bird," Dora Read Goodale; "To a Seabird," Bret Harte; "The Rain Song of the Robin," Kate Upson Clark; "The Swallow," Owen Meredith; "A Bird at Sunset," Owen Meredith; "The Titlark's Nest," Owen Meredith; "The Dead Eagle," Campbell; "Ode to a Nightingale," John Keats; "What the Birds Said," John Greenleaf Whittier; "The Sandpiper," Celia Thaxter; "The Blackbird and the Rooks," Dinah Mulock Craik; "The Canary in his Cage," Dinah Mulock Craik; "The Falcon," James Russell Lowell; "The Titmouse," Ralph Waldo Emerson; "The Stormy Petrel," Barry Cornwall; "To the Skylark," Percy Bysshe Shelley; "The O'Lincoln Family," Wilson Flagg; "To a Waterfowl," William Cullen Bryant; "Robert of Lincoln," William Cullen Bryant; "The Return of the Birds," William Cullen Bryant, "The Eagle," Alfred Tennyson; "To the Eagle," James G. Percival; "The Forerunner," Harriet Prescott Spofford; "The Skylark," James Hogg; "To the Skylark," William Wordsworth; "Sir Robin," Lucy Larcom; "The Pewee," J. T. Trowbridge; "The Yellowbird," Celia Thaxter "The Dying Swan," Alfred Tennyson; "Story of a Blackbird," Alice Cary; "The Blue Jay," Mrs. A. D. T. Whitney; "The Song Sparrow," Mrs. A. D. T. Whitney; "The Catbird," Mrs. A. D. T. Whitney; "Sparrows," Mrs. A. D. T. Whitney; "The Ovenbird," Mrs. A. D. T. Whitney; "The Vireos," Mrs. A. D. T. Whitney; "The Ovenbird," Frank Bolles; "Whip-poor-will," Frank Bolles; "The Veery," Henry Van Dyke; "The Song Sparrow," Henry Van Dyke; "The Wings of a Dove," Henry Van Dyke; "The Whip-poor-will," Henry Van Dyke; "To the Cuckoo," William Wordsworth; "Secrets," Susan Coolidge; "The Falcon," James Russell Lowell; "The Mocking Bird," Sidney Lanier; "Forbearance," Ralph Waldo Emerson; "The Mocking Bird," Clinton Scollard; "The Mocking Bird," Maurice Thompson; "The Mocking Bird," R. H. Wilde; "The Mocking Bird," A. B. Meek; "The Mocking Bird," Albert Pike; "The Song of the Thrush," Edward Markham. This list can of course be indefinitely extended. IN CHURCH Just in front of my pew sits a maiden-- A little brown wing on her hat, With its touches of tropical azure, And sheen of the sun upon that. Through the bloom-colored pane shines a glory By which the vast shadows are stirred, But I pine for the spirit and splendor That painted the wing of the bird. The organ rolls down its great anthem; With the soul of a song it is blent; But for me, I am sick for the singing Of one little song that is spent. The voice of the curate is gentle: "No sparrow shall fall to the ground;" But the poor broken wing on the bonnet Is mocking the merciful sound. --_Anonymous._ IX OBJECTS AND RESULTS OF BIRD DAY The general observance of a "Bird Day" in our schools would probably do more to open thousands of young minds to the reception of bird lore than anything else that can be devised. The scattered interests of the children would thus be brought together, and fused into a large and compact enthusiasm, which would become the common property of all. Zeal in a genuine cause is more contagious than a bad habit. The first Bird Day in the schools was celebrated on the first Friday in May, 1894. This is as good a date as any for the sections not in the extreme North or South. It would better come a little after the birds begin to arrive. The afternoon session will be found sufficient to devote to the special exercises. The date should be announced some time beforehand, so that the children may prepare for it. They will not only prepare themselves, but will have the whole community aroused by the sharp points of their inquisitorial weapons. Exercises should be held in all grades, from the primary to the high school. We quote the following from circular No. 17 sent out by the United States Department of Agriculture:-- OBJECT OF BIRD DAY From all sides come reports of a decrease in native birds, due to the clearing of the forests, draining of the swamps, and cultivation of lands, but especially to the increasing slaughter of birds for game, the demand for feathers to supply the millinery trade, and the breaking up of nests to gratify the egg-collecting proclivities of small boys. An attempt has been made to restrict these latter causes by legislation. Nearly every State and Territory has passed game laws, and several States have statutes protecting insectivorous birds. Such laws are frequently changed and cannot be expected to accomplish much unless supported by popular sentiment in favor of bird protection. This object can only be attained by demonstrating to the people the value of birds, and how can it be accomplished better than through the medium of the schools? Briefly stated, the object of Bird Day is to diffuse knowledge concerning our native birds and to arouse a more general interest in bird protection. As such it should appeal not only to ornithologists, sportsmen, and farmers, who have a practical interest in the preservation of birds, but also to the general public, who would soon appreciate the loss if the common songsters were exterminated. It is time to give more intelligent attention to the birds and appreciate their value. Many schools already have courses in natural history or nature study, and such a day would add zest to the regular studies, encourage the pupils to observe carefully, and give them something to look forward to and work for. In the words of the originator of the day, "the general observance of a Bird Day in our schools would probably do more to open thousands of young minds to the reception of bird lore than anything else that can be devised." The first thing is to interest the scholars in birds in general and particularly in those of their own locality. Good lists of birds have been prepared for several of the States, and popular books and articles on ornithology are within the reach of every one. But the instruction should not be limited to books; the children should be encouraged to observe the birds in the field, to study their habits and migrations, their nests and food, and should be taught to respect the laws protecting game and song birds. VALUE OF BIRD DAY When the question of introducing Arbor Day into the schools was brought before the National Educational Association in February, 1884, the objection was made that the subject was out of place in the schools. The value of the innovation could not be appreciated by those who did not see the practical bearing of the subject on an ordinary school course. But at the next meeting of the Association the question was again brought up and unanimously adopted--to the mutual benefit of the schools and of practical forestry. With the advent of more progressive ideas concerning education there is a demand for instruction in subjects which a few years ago would have been considered out of place, or of no special value. If the main object of our educational system is to prepare boys and girls for the intelligent performance of the duties and labors of life, why should not some attention be given to the study of nature, particularly in rural schools where the farmers of the next generation are now being educated? The study of birds may be taken up in several ways and for different purposes; it may be made to furnish simply a course in mental training or to assist the pupil in acquiring habits of accurate observation; it may be taken up alone or combined with composition, drawing, geography, or literature. But it has also an economic side which may appeal to those who demand purely practical studies in schools. Economic ornithology has been defined as the "study of birds from the standpoint of dollars and cents." It treats of the direct relations of birds to man, showing which species are beneficial and which injurious, teaching the agriculturist how to protect his feathered friends and guard against the attacks of his foes. This is a subject in which we are only just beginning to acquire exact knowledge, but it is none the less deserving of a place in our educational system on this account. Its practical value is recognized both by individual States and by the National Government, which appropriate considerable sums of money for investigations of value to agriculture. Much good work has been done by some of the experiment stations and State boards of agriculture, particularly in Illinois, Indiana, Massachusetts, Michigan, Nebraska, and Pennsylvania. In the United States Department of Agriculture, the Division of Biological Survey (formerly the Division of Ornithology) devotes much attention to the collection of data respecting the geographic distribution, migration, and food of birds, and to the publication and diffusion of information concerning species which are beneficial or injurious to agriculture. Some of the results of these investigations are of general interest, and could be used in courses of instruction in even the lower schools. Such facts would thus reach a larger number of persons than is now possible, and would be made more generally available to those interested in them. If illustrations of the practical value of a knowledge of zoölogy are necessary they can easily be given. It has been estimated recently that the forests and streams of Maine are worth more than its agricultural resources. If this is so, is it not equally as important to teach the best means of preserving the timber, the game, and the fish, as it is to teach students how to develop the agricultural wealth of the State? In 1885 Pennsylvania passed its famous "scalp act," and in less than two years expended between $75,000 and $100,000 in an attempt to rid the State of animals and birds supposed to be injurious. A large part of the money was spent for killing hawks and owls, most of which belonged to species which were afterwards shown to be actually beneficial. Not only was money thrown away in a useless war against noxious animals, but the State actually paid for the destruction of birds of inestimable value to its farmers. During the last five or six years two States have been engaged in an unsuccessful attempt to exterminate English sparrows by paying bounties for their heads. Michigan and Illinois have each spent more than $50,000; but, although millions of sparrows have been killed, the decrease in numbers is hardly perceptible. A more general knowledge of the habits of the English sparrow at the time the bird was first introduced into the United States would not only have saved this outlay of over $100,000, but would also have saved many other States from loss due to depredations by sparrows. Is it not worth while to do something to protect the birds and prevent their destruction before it is too late? A powerful influence for good can be exerted by the schools if the teachers will only interest themselves in the movement, and the benefit that will result to the pupils could hardly be attained in any other way at so small an expenditure of time. If it is deemed unwise to establish another holiday, or it may seem too much to devote one day in the year to the study of birds, the exercises of Bird Day might be combined with those of Arbor Day. It is believed that Bird Day can be adopted with profit by schools of all grades, and the subject is recommended to the thoughtful attention of teachers and school superintendents throughout the country, in the hope that they will coöperate with other agencies now at work to prevent the destruction of our native birds. T. S. PALMER, _Acting Chief of Division_. Approved: CHAS. W. DABNEY, JR., WASHINGTON, D. C., July 2, 1896. The results of Bird Day are noticeable in the schools in which it has been observed. The spirit of the schools has become fresher and brighter. There has been more marked improvement in the composition work and in the language of the pupils. Most of the children know the names of many of our birds and considerable of their ways of life, and wish to know more, and are their warm friends and protectors. The old relations between the small boy and the birds have been entirely changed. The birds themselves have been affected. They have become much more numerous. Many that were formerly rare visitants now nest freely in the shade trees of the city; for example, the orioles, the grosbeaks, the scarlet tanagers, and even the wood thrushes, and their nests are about as safe as the other homes. The children say that the birds know about Bird Day, and have come to help it along. The correlation of the public library and the public schools is assured in those towns where Bird Day has been introduced. If there were no other result of this new day, the demand for healthful literature would be enough. The call for Burroughs and Bradford Torrey, Olive Thorne Miller, and the other writers of our out-of-doors literature is so great as to attract attention in the libraries. In fact, in one the writer knows well there is a constant and steady demand, particularly from the boys. Frank Bolles is a great favorite with them. The excursions to the woods have a new and æsthetic interest. What would Emerson have thought when he wrote that matchless bit-- Hast thou named all the birds, without a gun? Loved the wood-rose and left it on its stalk? if he had known that the boys of another generation would be able to answer as he would have liked to have them! The effect upon teachers is not less marked. The trip to the woods in the early morning and at sunset, sometimes with the children and sometimes in parties by themselves, has resulted in physical and mental good. A new and charming relation has sprung up between teachers and children. The tie of community of interests is a strong one. A taste in common is always conducive to friendship. The surprising thing about this new departure in nature study is that once taken up it will never be abandoned. There is something fascinating in it. One may love trees and flowers, but their processes and habits of growth are in a way unrelated to us; but our "little brothers in feathers" are kin to us in their hopes and fears. "When I think," said a bright woman the other day, "that this summer I have learned to know by plumage and by song twenty birds, and when I realize the delight the knowledge has given me, I feel as if I ought to go out as a missionary to the heathen women in my neighborhood." She did not exaggerate the feeling of every bird lover. So much is lost to life and good cheer by this ignorance. Now that the Bird Day idea is being taken up and spread by the United States Government in the interests of economy, it will do much to sweeten the lives of the coming generation. The natural impulse to love and watch the birds will be encouraged instead of being disregarded. Hast thou named all the birds, without a gun? Loved the wood-rose, and left it on its stalk? O, be my friend, and teach me to be thine! --EMERSON. No longer now the winged inhabitants That in the woods their sweet lives sing away, Flee from the form of man, but gather round, And prune their feathers on the hands Which little children stretch in friendly sport Towards these dreadless partners of their play. --_Extract from_ SHELLEY'S _Queen Mab_. PART II NOTES ON REPRESENTATIVE BIRDS KINGBIRD (_Tyrannus tyrannus_) CALLED ALSO BEE BIRD, BEE MARTIN, AND TYRANT FLYCATCHER Length, about eight and one-half inches; spread of wings, fourteen and one-half inches. The upper parts of body are a blackish ash; top of head, black; crown with a concealed patch of orange red; lower parts pure white, tinged with pale bluish ash on the sides of the throat and across the breast; sides of the breast and under the wings rather lighter than the back; the wings dark brown, darkest towards the ends of the quills; upper surface of the tail glossy black, the feathers tipped with white. This bird is a common summer resident of the Middle States, where it usually arrives the last of April. The name _tyrannus_ given to it is descriptive of the character of the male, since during the breeding season he is anxious to attack everything wearing feathers. His particular aversion is hawks and crows, which he assails by mounting above his adversary and making repeated and violent assaults upon his head. He will even drive the eagle from his vicinity. The farmer could have no better protection for his corn fields than the near-by nest of a pair of kingbirds. They eat some honeybees, but for every bee thus taken they destroy ten noxious insects. They can be easily frightened away from the vicinity of the hives without being killed. The kingbird's nest is made of slender twigs, weed stalks, and grasses, and is placed among the branches of trees, fifteen to twenty-five feet from the ground. There are usually four or five eggs, white, spotted with brown. They have generally two broods a year. [Illustration: KINGBIRD] FLICKER (_Colaptes auratus_) CALLED ALSO YELLOW-HAMMER, PIGEON WOODPECKER, HITTOCK, AND YUCKER Length, twelve and one-half inches; extent, about twelve inches. The back and wings above are of a dark umber, cross marked with streaks of black; parts surrounding the eyes, a bright cinnamon color; upper part of head, dark gray; strip of black on each side of the throat about one inch long; a narrow crescent-shaped spot of a vivid red upon the back of the head. The breast is ornamented with a broad crescent of black; under parts of the body, white, tinged with yellow, and having many round spots of black; the lower side of the wing and tail, a beautiful golden yellow; the rump, white. This bird may be easily distinguished by the white rump and the bright yellow under the wings seen in flight. Its food consists largely of wood lice, ants, of which it is very fond, and of other insects which it finds upon the ground or upon trees. The female differs from the male in appearance, the black strips upon the sides of the throat being very indistinct or wanting entirely. The flicker's nest, like those of other woodpeckers, may be found in maples, oaks, apple trees, and occasionally pines or birches. They are more frequently built in clusters of trees than in exposed places, and from ten to thirty feet from the ground. The male has been noticed coming to the ground and throwing chips about, so that the nest-building might not be observed. The eggs are plain white. [Illustration: FLICKER] RED-HEADED WOODPECKER (_Melanerpes erythrocephalus_) Length, nine and one-half inches; extent, eighteen inches. The head and neck are crimson; a narrow crescent of black on the upper part of the breast; back, outer part of the wings, and tail, black glossed with blue; rump, lower part of the back, inner part of the wings, and the whole under parts, from the breast downwards, white; legs and feet, bluish green; claws, light blue. Like all woodpeckers, the tail feathers are sharp and stiff and help the bird to sustain itself upon the tree. It can strike hard blows with its bill, and drill into the hardest wood with rapidity and apparent ease. It will locate accurately the position of a grub or an insect that is within the wood of a tree, drill a hole to the inmate, and pull it out with its long, sticky tongue. The female is like the male in appearance, except that her colors are somewhat fainter. Woodpeckers as a class are beneficial, and do much to preserve trees from destructive insects. The red-headed woodpecker builds its nest at the bottom of a tunnel in a tree, dug by other birds, or adapted to use from an already existing cavity. The nest is a mere heap of soft, decaying wood, more attention being paid by the bird to securing protection against rain than in having the nest clean and nice. The eggs are white, speckled with reddish brown, and are usually six in number. [Illustration: RED-HEADED WOODPECKER] BLUE JAY (_Cyanocitta cristata_) Length, twelve inches; extent, seventeen inches. The head is crested; crest and upper back are a light purplish blue; wings and tail, bright blue; a collar of black proceeds from the hind part of the head, gracefully curving down each side of the neck to the upper part of the breast, where it forms a crescent; the chin, throat, and under parts are white or slightly tinged with blue; the tail is long and composed of twelve feathers marked with cross curves of black, each feather being tipped with white, except the two middle ones, which are a dark purple at the ends. The legs and bill are black. The nest of the blue jay is large and clumsily made, and is placed high in the branches of tall trees, the cedar being preferred. It is lined with fine, fibrous roots. The eggs are four or five in number, of a dull olive, spotted with brown. [Illustration: BLUE JAY] BOBOLINK (_Dolichonyx oryzivorus_) CALLED ALSO RICEBIRD, REEDBIRD, AND BOBLINCOLN Length, seven and one-fourth inches; extent, twelve and one-fourth inches. The female is a little smaller than the male. The male has the top and sides of the head and under parts black; large yellowish patch on the back of the neck; middle of back is streaked with buff; lower part of the back and upper tail feathers, grayish white; wings and tail, black; the bill is short, conical, and is blue black. The tail feathers are sharp-pointed and stiff like a woodpecker's. The female has the upper parts olive buff streaked with black; yellowish beneath; two stripes on the top of head; wings and tail, brownish; tail feathers with pointed tips. In the autumn the male puts on a dress similar to that of the female, the colors being a little more pronounced. The nest is built on the ground, of grasses. It contains from four to seven grayish eggs, spotted with blotches of brown. [Illustration: BOBOLINK] RED-WINGED BLACKBIRD (_Agelaius phoeniceus_) CALLED ALSO AMERICAN REDWING, MARSH BLACKBIRD, AND SWAMP BLACKBIRD Length, nine and one-half inches; spread of wings, fifteen and one-fourth inches. The male is of a uniform black, which glistens in the sunshine; shoulders bright scarlet bordered with brownish yellow; bill, legs, and feet black. The female is smaller than the male, and differs greatly from him in appearance. She is dark brown above, streaked with lighter and darker shades; below, gray streaked with brown; throat and edge of wing tinged with pink or yellow, but mostly pink in the summer. The young male at first resembles the female, but may soon be recognized by black feathers appearing in patches. The nests, which are composed chiefly of coarse grasses lined with finer grass, are built upon the ground or in low bushes. Those built in bushes are compact, the others are generally loosely made. The eggs number four to six, spotted and lined with black and brown. [Illustration: RED-WINGED BLACKBIRD] MEADOW LARK (_Sturnella magna_) CALLED ALSO FIELD LARK Length of male, ten and one-half inches; spread of wings, sixteen inches. The female is smaller. The feathers above are dark brown, with transverse dark brown bars across the wings and tail; the outer tail feathers, white; the throat, breast, under parts and edge of wing, bright yellow. A yellow spot extends from the nostril to the eye. The breast has a large black crescent, the points of which reach halfway up the neck; hind toes long, its claws twice as long as the middle one. The female is like the male, but duller in color. Their food is various forms of insects, beetles, grasshoppers, cutworms, larvæ, sometimes varied by the seeds of grasses and weeds, wild cherries, and berries. The nest is built upon the ground, of dried grasses, carefully concealed in tufts of grass. The eggs are oval, usually five in number; they are white, dotted with reddish brown. Both sexes engage in building the nest. [Illustration: MEADOW LARK] BALTIMORE ORIOLE (_Icterus galbula_) CALLED ALSO GOLDEN ROBIN, FIREBIRD, AND HANGBIRD Length, about eight inches; extent, twelve and one-half inches. The head, throat, and upper part of the back are black; the lower part of the back, the breast, and forward part of the wing are a brilliant orange. The base of the middle tail feathers is orange, the ends black; all the others are orange, with a black band in the middle. The female is smaller, and colors are not so bright. The nest is composed of various materials, such as grasses, plant fibers, hairs, strings, which are capable of being interwoven. It is suspended near the end of a limb. The eggs are commonly five in number. They are whitish and variously marked with black and brown spots and lines. [Illustration: BALTIMORE ORIOLE] SONG SPARROW (_Melospiza fasciata_) Length, a little over six inches; extent, about eight and one-half inches. General color of the upper parts brown streaked with black, gray, and different shades of brown; no white wing bars; the crown dull brown, with a faint grayish line in the middle; white line over the eye; under parts whitish with numerous dark brown streaks on the neck, breast, and sides; a conspicuous black spot in the middle of the breast; bill, legs, and feet are brownish. The female is the same as the male. The nest is composed of grasses, lined with finer grass. It is built in a low bush or on the ground. The eggs vary greatly both in size and in markings. They are generally five in number, and are greenish or bluish white, variously spotted with brown. These birds raise two and sometimes three broods. Not to know the song sparrow is to miss one of the delights of summer. [Illustration: SONG SPARROW] GOLDFINCH (_Spinus tristis_) CALLED ALSO YELLOWBIRD, THISTLE-BIRD, AND WILD CANARY Length, five and one-fourth inches; extent, nearly nine inches. The back and under parts are bright yellow; wings and crown cap, black; tips of the wing and tail feathers, white on their inner webs. The male in autumn loses his black cap, and his bright yellow parts change to a dull brownish yellow similar to the female; the wings and tail, however, remain darker and the white markings are more noticeable than those of the female. The female has no black cap; the wings and tail are dusky, marked with white as in the male; lower parts, yellowish gray; upper parts inclining to olive. The nest is cup-shaped, composed of plant fibers, lined with downy substances. The eggs are usually five in number, white or faintly bluish. [Illustration: GOLDFINCH] ROSE-BREASTED GROSBEAK (_Habia Ludoviciana_) Length, eight inches; extent, thirteen inches. Back, throat, and head are black; breast and under wings, rose-red; wings, black; rump, white tipped with black. The female is about the same size as the male. Her upper parts are brown, margined with buff and pale brown, with whitish line over the eye; wings and tail, dark gray; feathers of the fore wing tipped with white; under parts yellowish, streaked with brown. The nest is a thin, flat structure made of dried grasses and small twigs. The eggs are greenish white with brown spots; they are usually four in number. These birds are said to be great destroyers of potato bugs. [Illustration: ROSE-BREASTED GROSBEAK] CEDAR BIRD (_Ampelis cedrorum_) CALLED ALSO CHERRY BIRD, AMERICAN WAXWING, AND CANADIAN ROBIN Length, seven and one-fourth inches; extent, about twelve inches. The head is crested; general color, grayish brown; forehead, chin, and a line through the eye, black; tail and wings, gray; tail tipped with yellow; some of the shorter wing feathers are tipped with small oblong beads of red, resembling sealing wax. These birds are fond of cherries and berries. The fruit grower can protect his interests by planting some choke cherries, mulberries, and mountain ash trees at the edges of his orchard. Cedar birds destroy great quantities of insects, and are entitled to a part of the fruit which they have helped to save. The nest is large and loosely made of strips of bark, leaves, grasses, sometimes of mud, lined with finer materials. The eggs are usually five in number, dull gray spotted with black and brown. [Illustration: CEDAR BIRD] BROWN THRUSH (_Harporhynchus rufus_) CALLED ALSO BROWN THRASHER Length, eleven and one-fourth inches; extent, thirteen inches; tail, five and one-half inches long. The iris is yellow; upper parts, reddish or cinnamon brown; lower parts, white; feathers of middle wing edged with white; the breast and sides strongly spotted with dark brown. The nest is a carelessly made, bulky affair, composed of rootlets, strips of bark, twigs, leaves, and other material. It is generally poorly concealed in some low tree or even in the corner of a fence. For this reason it is frequently broken up. The eggs, four or five in number, are brownish mottled with darker brown. During the nesting season the bird at morning and in the afternoon ascends to the tops of trees and pours forth his wonderful song. He has even been thought to be "showing off," for he will sing almost as long as any one will stay to listen; but he is probably attracting attention to himself in order to detract it from his nest, which is always somewhere within the circle of his song. [Illustration: BROWN THRUSH] CHICKADEE (_Parus atricapillus_) CALLED ALSO BLACKCAP TITMOUSE Length, five and one-half inches; extent, eight inches. The general color of back is ashy; the top of head, throat, and chin black; no crest; under parts, whitish with buff on the sides; wing and tail feathers edged with white; legs, bluish gray; bill, black. The song of this bird is an oft-repeated _chick-a-dee_, from which it takes its name. Its call consists of two high notes, the first one a third above the second, which may be easily imitated, and the bird attracted to the vicinity of the person answering his call. Its nest is made of grasses and feathers, placed in a hole in a stump or tree; frequently in the deserted cavity made by a woodpecker. The eggs, six or seven, are white, spotted with brown about the larger end. [Illustration: CHICKADEE] CATBIRD (_Galeoscoptes Carolinensis_) Length, nine inches; extent, eleven and one-half inches. The general color is dark slate, somewhat lighter beneath; top of the head and tail, black; under side of tail near the base, chestnut; bill and feet, black; eye, brown. The female is like the male, but smaller. As a musician, this bird closely approaches the brown thrush. There are great differences in individual singers. The nest is bulky, composed of twigs, rootlets, dead leaves, strips of bark, etc. Strips of grapevine bark are quite commonly used, some nests being constructed almost wholly of this material. The eggs are generally four in number and of a greenish blue, unmarked. [Illustration: CATBIRD] BLUEBIRD (_Sialia sialis_) Length, six and one-half inches; extent, twelve and one-half inches. The upper parts, wings, and tail are bright blue; sides of the head and upper part of chin also blue; throat, breast, and sides, reddish brown; abdomen and under side of tail, white; legs and bill, blackish; eye, brown. The female is similarly marked, but the colors are duller. The bluebird's song is a continued pleasing, rich warble. The nest is loosely built of grasses, feathers, and soft material, in holes of trees, in hollows of posts, or in bird boxes. The eggs are light blue and are four or five in number. [Illustration: BLUEBIRD]	28,896	common-pile/project_gutenberg_filtered	21266	project gutenberg	project_gutenberg-dolma-0002.json.gz:1598	https://www.gutenberg.org/ebooks/21266.txt.utf-8
KcGJXzMBbNWcEiG5	8.3: Problems on Random Vectors and Joint Distributions	8.3: Problems on Random Vectors and Joint Distributions Exercise $\PageIndex{1}$ Two cards are selected at random, without replacement, from a standard deck. Let $X$ be the number of aces and $Y$ be the number of spades. Under the usual assumptions, determine the joint distribution and the marginals. - Answer - Let $X$ be the number of aces and $Y$ be the number of spades. Define the events $AS_i$, $A_i$, $S_i$, and $N_i$, $i = 1, 2$ of drawing ace of spades, other ace, spade (other than the ace), and neither on the i selection. Let $P(i, k) = P(X = i, Y = k)$. $P(0, 0) = P(N_1N_2) = \dfrac{36}{52} \cdot \dfrac{35}{51} = \dfrac{1260}{2652}$ $P(0, 1) = P(N_1S_2 \bigvee S_1N_2) = \dfrac{36}{52} \cdot \dfrac{12}{51} + \dfrac{12}{52} \cdot \dfrac{36}{51} = \dfrac{864}{2652}$ $P(0, 2) = P(S_1 S_2) = \dfrac{12}{52} \cdot \dfrac{11}{51} = \dfrac{132}{2652}$ $P(1, 0) = P(A_N_2 \bigvee N_1 S_2) = \dfrac{3}{52} \cdot \dfrac{36}{51} + \dfrac{36}{52} \cdot \dfrac{3}{51} = \dfrac{216}{2652}$ $P(1, 1) = P(A_1S_2 \bigvee S_1A_2 \bigvee AS_1N_2 \bigvee N_1AS_2) = \dfrac{3}{52} \cdot \dfrac{12}{51} + \dfrac{12}{52} \cdot \dfrac{3}{51} + \dfrac{1}{52} \cdot \dfrac{36}{51} + \dfrac{36}{52} \cdot \dfrac{1}{51} = \dfrac{144}{2652}$ $P(1, 2) = P(AS_1S_2 \bigvee S_1AS_2) = \dfrac{1}{52} \cdot \dfrac{12}{51} + \dfrac{12}{52} \cdot \dfrac{1}{51} = \dfrac{24}{2652}$ $P(2, 0) = P(A_1A_2) = \dfrac{3}{52} \cdot \dfrac{2}{51} = \dfrac{6}{2652}$ $P(2, 1) = P(AS_1A_2 \bigvee A_1AS_2) = \dfrac{1}{52} \cdot \dfrac{3}{51} + \dfrac{3}{52} \cdot \dfrac{1}{51} = \dfrac{6}{2652}$ $P(2, 2) = P(\emptyset) = 0$ % type npr08_01 % file npr08_01.m % Solution for Exercise 8.3.1. X = 0:2; Y = 0:2; Pn = [132 24 0; 864 144 6; 1260 216 6]; P = Pn/(5251); disp('Data in Pn, P, X, Y') npr08_01 % Call for mfile Data in Pn, P, X, Y % Result PX = sum(P) PX = 0.8507 0.1448 0.0045 PY = fliplr(sum(P')) PY = 0.5588 0.3824 0.0588 Exercise $\PageIndex{2}$ Two positions for campus jobs are open. Two sophomores, three juniors, and three seniors apply. It is decided to select two at random (each possible pair equally likely). Let $X$ be the number of sophomores and $Y$ be the number of juniors who are selected. Determine the joint distribution for the pair $\{X, Y\}$ and from this determine the marginals for each. - Answer - Let $A_i, B_i, C_i$ be the events of selecting a sophomore, junior, or senior, respectively, on the $i$th trial. Let $X$ be the number of sophomores and $Y$ be the number of juniors selected. Set $P(i, k) = P(X = i, Y = k)$ $P(0, 0) = P(C_1C_2) = \dfrac{3}{8} \cdot \dfrac{2}{7} = \dfrac{6}{56}$ $P(0, 1) = P(B_1C_2) + P(C_1B_2) = \dfrac{3}{8} \cdot \dfrac{3}{7} + \dfrac{3}{8} \cdot \dfrac{3}{7} = \dfrac{18}{56}$ $P(0, 2) = P(B_1B_2) = \dfrac{3}{8} \cdot \dfrac{2}{7} = \dfrac{6}{56}$ $P(1, 0) = P(A_1C_2) + P(C_1A_2) = \dfrac{2}{8} \cdot \dfrac{3}{7} + \dfrac{3}{8} \cdot \dfrac{2}{7} = \dfrac{12}{56}$ $P(1, 1) = P(A_1B_2) + P(B_1A_2) = \dfrac{2}{8} \cdot \dfrac{3}{7} + \dfrac{3}{8} \cdot \dfrac{2}{7} = \dfrac{12}{56}$ $P(2, 0) = P(A_1A_2) = \dfrac{2}{8} \cdot \dfrac{1}{7} = \dfrac{2}{56}$ $P(1, 2) = P(2, 1) = P(2, 2) = 0$ $PX =$ [30/56 24/56 2/56] $PY =$ [20/56 30/56 6/56] % file npr08_02.m % Solution for Exercise 8.3.2. X = 0:2; Y = 0:2; Pn = [6 0 0; 18 12 0; 6 12 2]; P = Pn/56; disp('Data are in X, Y,Pn, P') npr08_02 Data are in X, Y,Pn, P PX = sum(P) PX = 0.5357 0.4286 0.0357 PY = fliplr(sum(P')) PY = 0.3571 0.5357 0.1071 Exercise $\PageIndex{3}$ A die is rolled. Let $X$ be the number that turns up. A coin is flipped $X$ times. Let $Y$ be the number of heads that turn up. Determine the joint distribution for the pair $\{X, Y\}$. Assume $P(X = k) = 1/6$ for $1 \le k \le 6$ and for each $k$, $P(Y = j\|X = k)$ has the binomial ($k$, 1/2) distribution. Arrange the joint matrix as on the plane, with values of $Y$ increasing upward. Determine the marginal distribution for $Y$. (For a MATLAB based way to determine the joint distribution see Example 14.1.7 from "Conditional Expectation, Regression") - Answer - $P(X = i, Y = k) = P(X = i) P(Y = k\|X = i) = (1/6) P(Y = k\|X = i)$. % file npr08_03.m % Solution for Exercise 8.3.3. X = 1:6; Y = 0:6; P0 = zeros(6,7); % Initialize for i = 1:6 % Calculate rows of Y probabilities P0(i,1:i+1) = (1/6)ibinom(i,1/2,0:i); end P = rot90(P0); % Rotate to orient as on the plane PY = fliplr(sum(P')); % Reverse to put in normal order disp('Answers are in X, Y, P, PY') npr08_03 % Call for solution m-file Answers are in X, Y, P, PY disp(P) 0 0 0 0 0 0.0026 0 0 0 0 0.0052 0.0156 0 0 0 0.0104 0.0260 0.0391 0 0 0.0208 0.0417 0.0521 0.0521 0 0.0417 0.0625 0.0625 0.0521 0.0391 0.0833 0.0833 0.0625 0.0417 0.0260 0.0156 0.0833 0.0417 0.0208 0.0104 0.0052 0.0026 disp(PY) 0.1641 0.3125 0.2578 0.1667 0.0755 0.0208 0.0026 Exercise $\PageIndex{4}$ As a variation of Exercise 8.3.3 . , Suppose a pair of dice is rolled instead of a single die. Determine the joint distribution for the pair $\{X, Y\}$ and from this determine the marginal distribution for $Y$. - Answer - % file npr08_04.m % Solution for Exercise 8.3.4. X = 2:12; Y = 0:12; PX = (1/36)[1 2 3 4 5 6 5 4 3 2 1]; P0 = zeros(11,13); for i = 1:11 P0(i,1:i+2) = PX(i)ibinom(i+1,1/2,0:i+1); end P = rot90(P0); PY = fliplr(sum(P')); disp('Answers are in X, Y, PY, P') npr08_04 Answers are in X, Y, PY, P disp(P) Columns 1 through 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0005 0 0 0 0 0 0.0013 0.0043 0 0 0 0 0.0022 0.0091 0.0152 0 0 0 0.0035 0.0130 0.0273 0.0304 0 0 0.0052 0.0174 0.0326 0.0456 0.0380 0 0.0069 0.0208 0.0347 0.0434 0.0456 0.0304 0.0069 0.0208 0.0312 0.0347 0.0326 0.0273 0.0152 0.0139 0.0208 0.0208 0.0174 0.0130 0.0091 0.0043 0.0069 0.0069 0.0052 0.0035 0.0022 0.0013 0.0005 Columns 8 through 11 0 0 0 0.0000 0 0 0.0000 0.0001 0 0.0001 0.0003 0.0004 0.0002 0.0008 0.0015 0.0015 0.0020 0.0037 0.0045 0.0034 0.0078 0.0098 0.0090 0.0054 0.0182 0.0171 0.0125 0.0063 0.0273 0.0205 0.0125 0.0054 0.0273 0.0171 0.0090 0.0034 0.0182 0.0098 0.0045 0.0015 0.0078 0.0037 0.0015 0.0004 0.0020 0.0008 0.0003 0.0001 0.0002 0.0001 0.0000 0.0000 disp(PY) Columns 1 through 7 0.0269 0.1025 0.1823 0.2158 0.1954 0.1400 0.0806 Columns 8 through 13 0.0375 0.0140 0.0040 0.0008 0.0001 0.0000 Exercise $\PageIndex{5}$ Suppose a pair of dice is rolled. Let $X$ be the total number of spots which turn up. Roll the pair an additional $X$ times. Let $Y$ be the number of sevens that are thrown on the $X$ rolls. Determine the joint distribution for the pair $\{X, Y\}$ and from this determine the marginal distribution for $Y$. What is the probability of three or more sevens? - Answer - % file npr08_05.m % Data and basic calculations for Exercise 8.3.5. PX = (1/36)[1 2 3 4 5 6 5 4 3 2 1]; X = 2:12; Y = 0:12; P0 = zeros(11,13); for i = 1:11 P0(i,1:i+2) = PX(i)ibinom(i+1,1/6,0:i+1); end P = rot90(P0); PY = fliplr(sum(P')); disp('Answers are in X, Y, P, PY') npr08_05 Answers are in X, Y, P, PY disp(PY) Columns 1 through 7 0.3072 0.3660 0.2152 0.0828 0.0230 0.0048 0.0008 Columns 8 through 13 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 Exercise $\PageIndex{6}$ The pair $\{X, Y\}$ has the joint distribution (in m-file npr08_06.m ): $X =$ [-2.3 -0.7 1.1 3.9 5.1] $Y =$ = [1.3 2.5 4.1 5.3] Determine the marginal distribution and the corner values for $F_{XY}$. Determine $P(X + Y > 2)$ and $P(X \ge Y)$. - Answer - npr08_06 Data are in X, Y, P jcalc Enter JOINT PROBABILITIES (as on the plane) P Enter row matrix of VALUES of X X Enter row matrix of VALUES of Y Y Use array operations on matrices X, Y, PX, PY, t, u, and P disp([X;PX]') -2.3000 0.2300 -0.7000 0.1700 1.1000 0.2000 3.9000 0.2020 5.1000 0.1980 disp([Y;PY]') 1.3000 0.2980 2.5000 0.3020 4.1000 0.1900 5.3000 0.2100 jddbn Enter joint probability matrix (as on the plane) P To view joint distribution function, call for FXY disp(FXY) 0.2300 0.4000 0.6000 0.8020 1.0000 0.1817 0.3160 0.4740 0.6361 0.7900 0.1380 0.2400 0.3600 0.4860 0.6000 0.0667 0.1160 0.1740 0.2391 0.2980 P1 = total((t+u>2).P) P1 = 0.7163 P2 = total((t>=u).P) P2 = 0.2799 Exercise $\PageIndex{7}$ The pair $\{X, Y\}$ has the joint distribution (in m-file npr08_07.m ): $P(X = i, Y = u)$ \| t = \| -3.1 \| -0.5 \| 1.2 \| 2.4 \| 3.7 \| 4.9 \| \| u = 7.5 \| 0.0090 \| 0.0396 \| 0.0594 \| 0.0216 \| 0.0440 \| 0.0203 \| \| 4.1 \| 0.0495 \| 0 \| 0.1089 \| 0.0528 \| 0.0363 \| 0.0231 \| \| -2.0 \| 0.0405 \| 0.1320 \| 0.0891 \| 0.0324 \| 0.0297 \| 0.0189 \| \| -3.8 \| 0.0510 \| 0.0484 \| 0.0726 \| 0.0132 \| 0 \| 0.0077 \| Determine the marginal distributions and the corner values for $F_{XY}$. Determine $P(1 \le X \le 4, Y > 4)$ and $P(\|X - Y\| \le 2)$. - Answer - npr08_07 Data are in X, Y, P jcalc Enter JOINT PROBABILITIES (as on the plane) P Enter row matrix of VALUES of X X Enter row matrix of VALUES of Y Y Use array operations on matrices X, Y, PX, PY, t, u, and P disp([X;PX]') -3.1000 0.1500 -0.5000 0.2200 1.2000 0.3300 2.4000 0.1200 3.7000 0.1100 4.9000 0.0700 disp([Y;PY]') -3.8000 0.1929 -2.0000 0.3426 4.1000 0.2706 7.5000 0.1939 jddbn Enter joint probability matrix (as on the plane) P To view joint distribution function, call for FXY disp(FXY) 0.1500 0.3700 0.7000 0.8200 0.9300 1.0000 0.1410 0.3214 0.5920 0.6904 0.7564 0.8061 0.0915 0.2719 0.4336 0.4792 0.5089 0.5355 0.0510 0.0994 0.1720 0.1852 0.1852 0.1929 M = (1<=t)&(t<=4)&(u>4); P1 = total(M.P) P1 = 0.3230 P2 = total((abs(t-u)<=2).P) P2 = 0.3357 Exercise $\PageIndex{8}$ The pair $\{X, Y\}$ has the joint distribution (in m-file npr08_08.m ): $P(X = t, Y = u)$ \| t = \| 1 \| 3 \| 5 \| 7 \| 9 \| 11 \| 13 \| 15 \| 17 \| 19 \| \| u = 12 \| 0.0156 \| 0.0191 \| 0.0081 \| 0.0035 \| 0.0091 \| 0.0070 \| 0.0098 \| 0.0056 \| 0.0091 \| 0.0049 \| \| 10 \| 0.0064 \| 0.0204 \| 0.0108 \| 0.0040 \| 0.0054 \| 0.0080 \| 0.0112 \| 0.0064 \| 0.0104 \| 0.0056 \| \| 9 \| 0.0196 \| 0.0256 \| 0.0126 \| 0.0060 \| 0.0156 \| 0.0120 \| 0.0168 \| 0.0096 \| 0.0056 \| 0.0084 \| \| 5 \| 0.0112 \| 0.0182 \| 0.0108 \| 0.0070 \| 0.0182 \| 0.0140 \| 0.0196 \| 0.0012 \| 0.0182 \| 0.0038 \| \| 3 \| 0.0060 \| 0.0260 \| 0.0162 \| 0.0050 \| 0.0160 \| 0.0200 \| 0.0280 \| 0.0060 \| 0.0160 \| 0.0040 \| \| -1 \| 0.0096 \| 0.0056 \| 0.0072 \| 0.0060 \| 0.0256 \| 0.0120 \| 0.0268 \| 0.0096 \| 0.0256 \| 0.0084 \| \| -3 \| 0.0044 \| 0.0134 \| 0.0180 \| 0.0140 \| 0.0234 \| 0.0180 \| 0.0252 \| 0.0244 \| 0.0234 \| 0.0126 \| \| -5 \| 0.0072 \| 0.0017 \| 0.0063 \| 0.0045 \| 0.0167 \| 0.0090 \| 0.0026 \| 0.0172 \| 0.0217 \| 0.0223 \| Determine the marginal distributions. Determine $F_{XY} (10, 6)$ and $P(X > Y)$. $X$ is the amount of training, in hours, and $Y$ is the time to perform the task, in minutes. The data are as follows (in m-file npr08_09.m ): $P(X = t, Y = u)$ \| t = \| 1 \| 1.5 \| 2 \| 2.5 \| 3 \| \| u = 5 \| 0.039 \| 0.011 \| 0.005 \| 0.001 \| 0.001 \| \| 4 \| 0.065 \| 0.070 \| 0.050 \| 0.015 \| 0.010 \| \| 3 \| 0.031 \| 0.061 \| 0.137 \| 0.051 \| 0.033 \| \| 2 \| 0.012 \| 0.049 \| 0.163 \| 0.058 \| 0.039 \| \| 1 \| 0.003 \| 0.009 \| 0.045 \| 0.025 \| 0.017 \| Determine the marginal distributions. Determine $F_{XY}(2, 3)$ and $P(Y/X \ge 1.25)$. - Use a discrete approximation to plot the marginal density $f_X$ and the marginal distribution function $F_X$. - Calculate analytically the indicated probabilities. - Determine by discrete approximation the indicated probabilities. Exercise $\PageIndex{10}$ $f_{XY}(t, u) = 1$ for $0 \le t \le 1$, $0 \le u \le 2(1 - t)$. $P(X > 1/2, Y > 1), P(0 \le X \le 1/2, Y > 1/2), P(Y \le X)$ - Answer - Region is triangle with vertices (0, 0), (1, 0), (0, 2). $f_{X} (t) = \int_{0}^{2(1-t)} du = 2(1 - t)$, $0 \le t \le 1$ $f_{Y} (u) = \int_{0}^{1 - u/2} dt = 1 - u/2$, $0 \le u \le 2$ $M1 = \{(t, u):t > 1/2, u> 1\}$ lies outside the trianlge $P((X, Y) \in M1) = 0$ $M2 = \{(t, u): 0 \le t \le 1/2, u > 1/2\}$ has area in the triangle = 1/2 $M3$ = the region in the triangle under $u = t$, which has area 1/3 tuappr Enter matrix [a b] of X-range endpoints [0 1] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 400 Enter expression for joint density (t<=1)&(u<=2(1-t)) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) % Figure not reproduced M1 = (t>0.5)&(u>1); P1 = total(M1.P) P1 = 0 % Theoretical = 0 M2 = (t<=0.5)&(u>0.5); P2 = total(M2.P) P2 = 0.5000 % Theoretical = 1/2 P3 = total((u<=t).P) P3 = 0.3350 % Theoretical = 1/3 Exercise $\PageIndex{11}$ $f_{XY} (t, u) = 1/2$ on the square with vertices at (1, 0), (2, 1), (1, 2), (0, 1). $P(X > 1, Y > 1), P(X \le 1/2, 1 < Y), P(Y \le X)$ - Answer - The region is bounded by lines $u = 1 + t$, $ u = 1 - t$, $u = 3 - t$, and $u = t - 1$ $f_X (t) = I_{[0,1]} (t) 0.5 \int_{1 - t}^{1 + t} du + I_{(1, 2]} (t) 0.5 \int_{t - 1}^{3 - t} du = I_{(1, 2]} (t) (2 - t) = f_Y(t)$ by symmetry $M1 = \{(t, u): t > 1, u > 1\}$ has area in the trangle = 1/2, so $PM1 = 1/4$ $M2 = \{(t, u): t \le 1/2, u > 1\}$ has area in the trangle = 1/8\), so $PM2 = 1/16$ $M3 = \{(t, u): u \le t\}$ has area in the trangle = 1, so $PM3 = 1/2$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density 0.5(u<=min(1+t,3-t))& ... (u>=max(1-t,t-1)) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) % Plot not shown M1 = (t>1)&(u>1); PM1 = total(M1.P) PM1 = 0.2501 % Theoretical = 1/4 M2 = (t<=1/2)&(u>1); PM2 = total(M2.P) PM2 = 0.0631 % Theoretical = 1/16 = 0.0625 M3 = u<=t; PM3 = total(M3.P) PM3 = 0.5023 % Theoretical = 1/2 Exercise $\PageIndex{12}$ $f_{XY} (t, u) = 4t(1 - u)$ for $0 \le t \le 1$, $0 \le u \le 1$. $P(1/2 < X < 3/4, Y > 1/2)$, $P(X \le 1/2, Y > 1/2)$, $P(Y \le X)$ - Answer - Region is the unit square, $f_X (t) = \int_{0}^{1} 4t(1 - u) du = 2t$, $0 \le t \le 1$ $f_Y(u) = \int_{0}^{1} 4t(1 - u) dt = 2(1 - u)$, $0 \le u \le 1$ $P1 = \int_{1/2}^{3/4} \int_{1/2}^{1} 4t (1 - u) du dt = 5/64$ $P2 = \int_{0}^{1/2} \int_{1/2}^{1} 4t(1 - u) dudt = 1/16$ $P3 = \int_{0}^{1} \int_{0}^{t} 4t(1 - u) du dt = 5/6$ tuappr Enter matrix [a b] of X-range endpoints [0 1] Enter matrix [c d] of Y-range endpoints [0 1] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density 4t.(1 - u) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) % Plot not shown M1 = (1/2<t)&(t<3/4)&(u>1/2); P1 = total(M1.P) P1 = 0.0781 % Theoretical = 5/64 = 0.0781 M2 = (t<=1/2)&(u>1/2); P2 = total(M2.P) P2 = 0.0625 % Theoretical = 1/16 = 0.0625 M3 = (u<=t); P3 = total(M3.P) P3 = 0.8350 % Theoretical = 5/6 = 0.8333 Exercise $\PageIndex{13}$ $f_{XY} (t, u) = \dfrac{1}{8} (t + u)$ for $0 \le t \le 2$, $0 \le u \le 2$. $P(X > 1/2, Y > 1/2), P(0 \le X \le 1, Y > 1), P(Y \le X)$ - Answer - Region is the square $0 \le t \le 2$, $0 \le u \le 2$ $f_X (t) = \dfrac{1}{8} \int_{0}^{2} (t + u) = \dfrac{1}{4} ( t + 1) = f_Y(t)$, $0 \le t \le 2$ $P1 = \int_{1/2}^{2} \int_{1/2}^{2} (t + u) dudt = 45/64$ $P2 = \int_{0}^{1} \int_{1}^{2} (t + u) du dt = 1/4$ $P3 = \int_{0}^{2} \int_{0}^{1} (t + u) dudt = 1/2$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density (1/8)(t+u) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) M1 = (t>1/2)&(u>1/2); P1 = total(M1.P) P1 = 0.7031 % Theoretical = 45/64 = 0.7031 M2 = (t<=1)&(u>1); P2 = total(M2.P) P2 = 0.2500 % Theoretical = 1/4 M3 = u<=t; P3 = total(M3.P) P3 = 0.5025 % Theoretical = 1/2 Exercise $\PageIndex{14}$ $f_{XY}(t, u) = 4ue^{-2t}$ for $0 \le t, 0 \le u \le 1$ $P(X \le 1, Y > 1), P(X > 0, 1/2 < Y < 3/4), P(X < Y)$ - Answer - Region is strip by $t = 0, u = 0, u = 1$ $f_X(t) = 2e^{-2t}$, $0 \le t$, $f_Y(u) = 2u$, $0 \le u \le 1$, $f_{XY} = f_X f_Y$ $P1 = 0$, $P2 = \int_{0.5}^{\infty} 2e^{-2t} dt \int_{1/2}^{3/4} 2udu = e^{-1} 5/16$ $P3 = 4 \int_{0}^{1} \int_{t}^{1} ue^{-2t} dudt = \dfrac{3}{2} e^{-2} + \dfrac{1}{2} = 0.7030$ tuappr Enter matrix [a b] of X-range endpoints [0 3] Enter matrix [c d] of Y-range endpoints [0 1] Enter number of X approximation points 400 Enter number of Y approximation points 200 Enter expression for joint density 4u.exp(-2t) Use array operations on X, Y, PX, PY, t, u, and P M2 = (t > 0.5)&(u > 0.5)&(u<3/4); p2 = total(M2.P) p2 = 0.1139 % Theoretical = (5/16)exp(-1) = 0.1150 p3 = total((t<u).P) p3 = 0.7047 % Theoretical = 0.7030 Exercise $\PageIndex{15}$ $f_{XY} (t, u) = \dfrac{3}{88} (2t + 3u^2)$ for $0 \le t \le 2$, $0 \le u \le 1 + t$. $F_{XY} (1, 1)$, $P(X \le 1, Y > 1)$, $P(\|X - Y\| < 1)$ - Answer - Region bounded by $t = 0$, $t = 2$, $u = 0$, $u = 1 + t$ $f_X (t) = \dfrac{3}{88} \int_{0}^{1 + t} (2t + 3u^2) du = \dfrac{3}{88}(1 + t)(1 + 4t + t^2) = \dfrac{3}{88} ( 1 + 5t + 5t^2 + t^3)$, $0 \le t \le 2$ $f_Y(u) = I_{[0,1]} (u) \dfrac{3}{88} \int_{0}^{2} (2t + 3u^2) dt + I_{(1, 3]} (u) \dfrac{3}{88} \int_{u - 1}^{2} (2t + 3u^2) dt = $ $I_{[0,1]} (u) \dfrac{3}{88} (6u^2 + 4) + I_{(1,3]} (t) \dfrac{3}{88} (3 + 2u + 8u^2 - 3u^3)$ $F_{XY}(1, 1) = \int_{0}^{1} \int_{0}^{1} f_{XY} (t, u) dudt = 3/44$ $P1 = \int_{0}^{1} \int_{1}^{1 + t} f_{XY} (t, u)dudt = 41/352$ $P2 = \int_{0}^{1} \int_{1}^{1 + t} f_{XY} (t, u) dudt = 329/352$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 3] Enter number of X approximation points 200 Enter number of Y approximation points 300 Enter expression for joint density (3/88)(2t+3u.^2).(u<=1+t) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) MF = (t<=1)&(u<=1); F = total(MF.P) F = 0.0681 % Theoretical = 3/44 = 0.0682 M1 = (t<=1)&(u>1); P1 = total(M1.P) P1 = 0.1172 % Theoretical = 41/352 = 0.1165 M2 = abs(t-u)<1; P2 = total(M2.P) P2 = 0.9297 % Theoretical = 329/352 = 0.9347 Exercise $\PageIndex{16}$ $f_{XY} (t, u) = 12t^2u$ on the parallelogram with vertices (-1, 0), (0, 0), (1, 1), (0, 1). $P(X \le 1/2, Y > 0), P(X < 1/2, Y \le 1/2), P(Y \ge 1/2)$ - Answer - Region bounded by $u = 0$, $u = t$, $u = 1$, $u = t + 1$ $f_X (t) = I_{[-1, 0]} (t) 12 \int_{0}^{t + 1} t^2 u du + I_{(0, 1]} (t) 12 \int_{t}^{1} t^2 u du = I_{[-1, 0]} (t) 6t^2 (t + 1)^2 + I_{(0, 1]}(t) 6t^2(1 - t^2)$ $f_Y(u) = 12\int_{u - 1}^{t} t^2 udu + 12u^3 - 12u^2 + 4u$, $0 \le u \le 1$ $P1 = 1 - 12 \int_{1/2}^{1} \int_{t}^{1} t^2 ududt = 33/80$, $P2 = 12 \int_{0}^{1/2} \int_{u - 1}^{u} t^2 udtdu = 3/16$ $P3 = 1 - P2 = 13/16$ tuappr Enter matrix [a b] of X-range endpoints [-1 1] Enter matrix [c d] of Y-range endpoints [0 1] Enter number of X approximation points 400 Enter number of Y approximation points 200 Enter expression for joint density 12u.t.^2.((u<=t+1)&(u>=t)) Use array operations on X, Y, PX, PY, t, u, and P p1 = total((t<=1/2).P) p1 = 0.4098 % Theoretical = 33/80 = 0.4125 M2 = (t<1/2)&(u<=1/2); p2 = total(M2.P) p2 = 0.1856 % Theoretical = 3/16 = 0.1875 P3 = total((u>=1/2).P) P3 = 0.8144 % Theoretical = 13/16 = 0.8125 Exercise $\PageIndex{17}$ $f_{XY} (t, u) = \dfrac{24}{11} tu$ for $0 \le t \le 2$, $0 \le u \le \text{min}\ \{1, 2 - t\}$ $P(X \le 1, Y \le 1), P(X > 1), P(X < Y)$ - Answer - Region is bounded by $t = 0, u = 0, u = 2, u = 2 - t$ $f_X (t) = I_{[0, 1]} (t) \dfrac{24}{11} \int_{0}^{1} tudu + I_{(1, 2]} (t) \dfrac{24}{11} \int_{0}^{2 - t} tudu =$ $I_{[0, 1]} (t) \dfrac{12}{11} t + I_{(1, 2]} (t) \dfrac{12}{11} t(2 - t)^2$ $f_Y (u) = \dfrac{24}{11} \int_{0}^{2 - u} tudt = \dfrac{12}{11} u(u - 2)^2$, $0 \le u \le 1$ $P1 = \dfrac{24}{11} \int_{0}^{1} \int_{0}^{1} tududt = 6/11$ $P2 = \dfrac{24}{11} \int_{1}^{2} \int_{0}^{2 - t} tududt = 5/11$ $P3 = \dfrac{24}{11} \int_{0}^{1} \int_{t}^{1} tududt = 3/11$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 1] Enter number of X approximation points 400 Enter number of Y approximation points 200 Enter expression for joint density (24/11)t.u.(u<=2-t) Use array operations on X, Y, PX, PY, t, u, and P M1 = (t<=1)&(u<=1); P1 = total(M1.P) P1 = 0.5447 % Theoretical = 6/11 = 0.5455 P2 = total((t>1).P) P2 = 0.4553 % Theoretical = 5/11 = 0.4545 P3 = total((t<u).P) P3 = 0.2705 % Theoretical = 3/11 = 0.2727 Exercise $\PageIndex{18}$ $f_{XY} (t, u) = \dfrac{3}{23} (t + 2u)$ for $0 \le t \le 2$, $0 \le u \le \text{max}\ \{2 - t, t\}$ $P(X \ge 1, Y \ge 1), P(Y \le 1), P(Y \le X)$ - Answer - Region is bounded by $t = 0, t = 2, u = 0, u = 2 - t$ $(0 \le t \le 1)$, $u = t (1 < t \le 2)$ $f_X(t) = I_{[0,1]} (t) \dfrac{3}{23} \int_{0}^{2 - t} (t + 2u) du + I_{(1, 2]} (t) \dfrac{3}{23} \int_{0}^{t} (t + 2u) du = I_{[0, 1]} (t) \dfrac{6}{23} (2 - t) + I_{(1, 2]} (t) \dfrac{6}{23}t^2$ $f_Y(u) = I_{[0, 1]} (u) \dfrac{3}{23} \int_{0}^{2} (t + 2u) du + I_{(1, 2]} (u) [\dfrac{3}{23} \int_{0}^{2 - u} (t + 2u) dt + \dfrac{3}{23} \int_{u}^{2} (t + 2u) dt]=$ $I_{[0,1]} (u) \dfrac{6}{23} (2u + 1) + I_{(1, 2]} (u) \dfrac{3}{23} (4 + 6u - 4u^2)$ $P1 = \dfrac{3}{23} \int_{1}^{2} \int_{1}^{t} (t + 2u) du dt = 13/46$, $P2 = \dfrac{3}{23} \int_{0}^{2} \int_{0}^{1} (t + 2u) du dt = 12/23$ $P3 = \dfrac{3}{23} \int_{0}^{2} \int_{0}^{t} (t + 2u) dudt = 16/23$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density (3/23)(t+2u).(u<=max(2-t,t)) Use array operations on X, Y, PX, PY, t, u, and P M1 = (t>=1)&(u>=1); P1 = total(M1.P) P1 = 0.2841 13/46 % Theoretical = 13/46 = 0.2826 P2 = total((u<=1).P) P2 = 0.5190 % Theoretical = 12/23 = 0.5217 P3 = total((u<=t).P) P3 = 0.6959 % Theoretical = 16/23 = 0.6957 Exercise $\PageIndex{19}$ $f_{XY} (t, u) = \dfrac{12}{179} (3t^2 + u)$, for $0 \le t \le 2$, $0 \le u \le \text{min } \{1 + t, 2\}$ $P(X \ge 1, Y \ge 1), P(X \le 1, Y \le 1), P(Y < X)$ - Answer - Region has two parts: (1) $0 \le t \le 1, 0 \le u \le 2$ (2) $1 < t \le 2, 0 \le u \le 3 - t$ $f_X (t) = I_{[0, 1]} (t) \dfrac{12}{179} \int_{0}^{2} (3t^2 + u) du + I_{(1, 2]} (t) \dfrac{12}{179} \int_{0}^{3 - t} (3t^2 + u) du =$ $I_{[0, 1]} (t) \dfrac{24}{179} (3t^2 + 1) + I_{(1, 2]} (t) \dfrac{6}{179} (9 - 6t + 19t^2 - 6t^3)$ $f_Y(u) = I_{[0, 1]} (u) \dfrac{12}{179} \int_{0}^{2}(3t^2 + u) dt + I_{(1, 2]} (u) \dfrac{12}{179} \int_{0}^{3 - u} (3t^2 + u) dt =$ $I_{[0, 1]} (u) \dfrac{24}{179} (4 + u) + I_{(1, 2]} (u) \dfrac{12}{179} (27 - 24u + 8u^2 - u^3)$ $P1 = \dfrac{12}{179} \int{1}^{2} \int_{1}^{3 - t} (3t^2 + u) du dt = 41/179$ $P2 = \dfrac{12}{179} \int_{0}^{1} \int_{0}^{1} (3t^2 + u) dudt = 18/179$ $P3 = \dfrac{12}{179} \int_{0}^{3/2} \int_{0}^{t} (3t^2 + u) dudt + \dfrac{12}{179} \int_{3/2}^{2} \int_{0}^{3 - t} (3t^2 + u) dudt = 1001/1432$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density (12/179)(3t.^2+u). ... (u<=min(2,3-t)) Use array operations on X, Y, PX, PY, t, u, and P fx = PX/dx; FX = cumsum(PX); plot(X,fx,X,FX) M1 = (t>=1)&(u>=1); P1 = total(M1.P) P1 = 2312 % Theoretical = 41/179 = 0.2291 M2 = (t<=1)&(u<=1); P2 = total(M2.P) P2 = 0.1003 % Theoretical = 18/179 = 0.1006 M3 = u<=min(t,3-t); P3 = total(M3.P) P3 = 0.7003 % Theoretical = 1001/1432 = 0.6990 Exercise $\PageIndex{20}$ $f_{XY} (t, u) = \dfrac{12}{227} (3t + 2tu)$ for $0 \le t \le 2$, $0 \le u \le \text{min} \{1 + t, 2\}$ $P(X \le 1/2, Y \le 3/2), P(X \le 1.5, Y > 1), P(Y < X)$ - Answer - Region is in two parts: - $0 \le t \le 1$, $0 \le u \le 1 + t$ - $1 < t \le 2$, $0 \le u \le 2$ $f_X(t) = I_{[0,1]} (t) \int_{0}^{1+t} f_{XY} (t, u) du + I_{(1, 2]} (t) \int_{0}^{2} f_{XY} (t, u) du =$ $I_{[0, 1]} (t) \dfrac{12}{227} (t^3 + 5t^2 + 4t) + I_{(1, 2]} (t) \dfrac{120}{227} t$ $f_Y(u) = I_{[0, 1]} (u) \int_{0}^{2} f_{XY} (t, u) dt + I_{(1, 2]} (u) \int_{u - 1}^{2} f_{XY} (t, u) dt = $ $I_{[0, 1]} (u) \dfrac{24}{227} (2u + 3) + I_{(1, 2]} (u) \dfrac{6}{227} (2u + 3) (3 + 2u - u^2)$ $= I_{[0, 1]} (u) \dfrac{24}{227} (2u + 3) + I_{(1, 2]} (u) \dfrac{6}{227} (9 + 12 u + u^2 - 2u^3)$ $P1 = \dfrac{12}{227} \int_{0}^{1/2} \int_{0}^{1 + t} (3t + 2tu) du dt = 139/3632$ $P2 = \dfrac{12}{227} \int_{0}^{1} \int_{1}^{1 + t} (3t + 2tu) dudt + \dfrac{12}{227} \int_{1}^{3/2} \int_{1}^{2} (3t + 2tu) du dt = 68/227$ $P3 = \dfrac{12}{227} \int_{0}^{2} \int_{1}^{t} (3t + 2tu) dudt = 144/227$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 200 Enter number of Y approximation points 200 Enter expression for joint density (12/227)(3t+2t.u). ... (u<=min(1+t,2)) Use array operations on X, Y, PX, PY, t, u, and P M1 = (t<=1/2)&(u<=3/2); P1 = total(M1.P) P1 = 0.0384 % Theoretical = 139/3632 = 0.0383 M2 = (t<=3/2)&(u>1); P2 = total(M2.P) P2 = 0.3001 % Theoretical = 68/227 = 0.2996 M3 = u<t; P3 = total(M3.P) P3 = 0.6308 % Theoretical = 144/227 = 0.6344 Exercise $\PageIndex{21}$ $f_{XY} (t, u) = \dfrac{2}{13} (t + 2u)$ for $0 \le t \le 2$, $0 \le u \le \text{min}\ \{2t, 3 - t\}$ $P(X < 1), P(X \ge 1, Y \le 1), P(Y \le X/2)$ - Answer - Region bounded by $t = 2, u = 2t$ $(0 \le t \le 1)$, $3 - t$ $(1 \le t \le 2)$ $f_X(t) = I_{[0, 1]} (t) \dfrac{2}{13} \int_{0}^{2t} (t + 2u) du + I_{(1, 2]} (t) \dfrac{2}{13} \int_{0}^{3 - t} (t + 2u) du = I_{[0, 1]} (t) \dfrac{12}{13} t^2 + I_{(1, 2]} (t) \dfrac{6}{13} (3 - t)$ $f_Y (u) = I_{[0, 1]} (u) \dfrac{2}{13} \int_{u/2}^{2} (t + 2u) dt + I_{(1, 2]} (u) \dfrac{2}{13} \int_{u/2}^{3 - u} (t + 2u) dt =$ $I_{[0, 1]} (u) (\dfrac{4}{13} + \dfrac{8}{13}u - \dfrac{9}{52} u^2) + I_{(1, 2]} (u) (\dfrac{9}{13} + \dfrac{6}{13} u - \dfrac{21}{52} u^2)$ $P1 = \int_{0}^{1} \int_{0}^{2t} (t + 2u) dudt = 4/13$ $P2 = \int_{1}^{2} \int_{0}^{1} (t + 2u)dudt = 5/13$ $P3 = \int_{0}^{2} \int_{0}^{u/2} (t + 2u) dudt = 4/13$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 2] Enter number of X approximation points 400 Enter number of Y approximation points 400 Enter expression for joint density (2/13)(t+2u).(u<=min(2t,3-t)) Use array operations on X, Y, PX, PY, t, u, and P P1 = total((t<1).P) P1 = 0.3076 % Theoretical = 4/13 = 0.3077 M2 = (t>=1)&(u<=1); P2 = total(M2.P) P2 = 0.3844 % Theoretical = 5/13 = 0.3846 P3 = total((u<=t/2).P) P3 = 0.3076 % Theoretical = 4/13 = 0.3077 Exercise $\PageIndex{22}$ $f_{XY} (t, u) = I_{[0, 1]} (t) \dfrac{3}{8} (t^2 + 2u) + I_{(1, 2]} (t) \dfrac{9}{14} t^2u^2$ for $0 \le u \le 1$. $P(1/2 \le X \le 3/2, Y \le 1/2)$ - Answer - Region is rectangle bounded by $t = 0$, $t = 2$, $u = 0$, $u = 1$ $f_{XY} (t, u) = I_{[0, 1]} (t) \dfrac{3}{8} (t^2 + 2u) + I_{(1, 2]} (t) \dfrac{9}{14} t^2 u^2$, $0 \le u \le 1$ $f_X (t) = I_{[0, 1]} (t) \dfrac{3}{8} \int_{0}^{1} (t^2 + 2u) du + I_{(1, 2]} (t) \dfrac{9}{14} \int_{0}^{1} t^2 u^2 du = I_{[0,1]} (t) \dfrac{3}{8} (t^2 + 1) + I_{(1, 2]} (t) \dfrac{3}{14} t^2$ $f_Y(u) = \dfrac{3}{8} \int_{0}^{1} (t^2 + 2u0 dt + \dfrac{9}{14} \int_{1}^{2} t^2 u^2 dt = \dfrac{1}{8} + \dfrac{3}{4} u + \dfrac{3}{2} u^2$ $0 \le u \le 1$ $P1 = \dfrac{3}{8} \int_{1/2}^{1} \int_{0}^{1/2} (t^2 + 2u) dudt + \dfrac{9}{14} \int_{1}^{3/2} \int_{0}^{1/2} t^2 u^2 dudt = 55/448$ tuappr Enter matrix [a b] of X-range endpoints [0 2] Enter matrix [c d] of Y-range endpoints [0 1] Enter number of X approximation points 400 Enter number of Y approximation points 200 Enter expression for joint density (3/8)(t.^2+2u).(t<=1) ... + (9/14)(t.^2.u.^2).(t > 1) Use array operations on X, Y, PX, PY, t, u, and P M = (1/2<=t)&(t<=3/2)&(u<=1/2); P = total(M.*P) P = 0.1228 % Theoretical = 55/448 = 0.1228	6,851	common-pile/libretexts_filtered	https://stats.libretexts.org/Bookshelves/Probability_Theory/Applied_Probability_(Pfeiffer)/08%3A_Random_Vectors_and_Joint_Distributions/8.03%3A_Problems_on_Random_Vectors_and_Joint_Distributions	libretexts	libretexts-0000.json.gz:43925	https://stats.libretexts.org/Bookshelves/Probability_Theory/Applied_Probability_(Pfeiffer)/08%3A_Random_Vectors_and_Joint_Distributions/8.03%3A_Problems_on_Random_Vectors_and_Joint_Distributions
q_dFnm6H_JVGPoDw	9.11: Plagiarism and Self-Plagiarism	9.11: Plagiarism and Self-Plagiarism Plagiarism involves integrating another person’s ideas and intellectual material into your writing without giving them credit or citing them . In nursing, you will cite sources including peer-reviewed journals, textbooks, and websites. It might seem funny, but you can also plagiarize yourself: self-plagiarism is a type of plagiarism where you don’t reference ideas that you previously wrote about in other assignments. Why do people plagiarize? Sometimes a writer plagiarizes work on purpose, for example, by copying and pasting or purchasing an essay from a website and submitting it as original work. See Figure 9.2 . This may happen because the writer has not managed their time and has left the paper to the last minute, or has struggled with the writing process or the topic. This can lead to desperation and cause the writer to take credit for someone else’s ideas. In other cases, a writer may commit accidental plagiarism due to carelessness, haste, or misunderstanding. A writer may be unable to provide a complete, accurate citation because they neglected to record the bibliographical information, for example, by cutting and pasting from a website and then forgetting where the material came from. Or, a writer who procrastinates may rush through a draft, which easily leads to sloppy paraphrasing and inaccurate quotations. These careless actions can create the appearance of plagiarism and lead to negative consequences. Both types of plagiarism have serious consequences that can affect your success in your program . Turnitin Turnitin is a tool that helps instructors identify plagiarism. Your instructor may provide a link for you to submit your paper to the Turnitin website for scanning. This detection service compares your writing to a vast collection of writing (including Internet sources and other student papers) from around the world. It uses a similarity index to identify components of your writing that are similar to other sources. Don’t plagiarize – you will get caught! How to avoid plagiarism? You can avoid plagiarism by following these simple rules (also, see Film Clip 9.2 ): - Start by writing what you know about a subject, turning to sources only when you need to support your own ideas with authoritative backing or when there’s a knowledge gap you cannot fill on your own. Or, of course, to satisfy requirements required by your instructor, who may require you to cite a certain number of sources to support your writing. Even then, most of the work should be your own. - Take notes carefully. If you add source material to your work, mark it or identify it in such a way that you will know it’s from a source. Cite the work immediately and add it to your reference list. - If you use someone else’s intellectual property, you must give them credit. - Changing a few words from a source and presenting it as your own is still plagiarism. Carefully follow guidelines on how to paraphrase and quote source material, coming up on the next page. Film Clip 9.2 : Avoiding plagiarism [2:00] Student Tip Previously Graded Work Most instructors will not permit you to submit previously graded work in their course, and using your own ideas from previous assignments can place you at risk for self-plagiarism. You should try to choose a completely different topic to avoid the temptation to reuse previously submitted work. However, an instructor will sometimes ask you to build on your ideas from a previous paper; in this case, you might want to have a discussion with the instructor about self-plagiarism. Activities: Check Your Understanding The original version of this chapter contained H5P content. You may want to remove or replace this element. The original version of this chapter contained H5P content. You may want to remove or replace this element. Attribution statement The section about “Why do people plagiarize?” is an adaptation of (editorial changes): Writing for Success 1st Canadian Edition by Tara Horkoff, licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted. Download for free at: https://opentextbc.ca/writingforsuccess/ The section about “How to avoid plagiarism? is an adaptation (editorial changes) of: The Word on College Reading and Writing by Carol Burnell, Jaime Wood, Monique Babin, Susan Pesznecker, and Nicole Rosevear, licensed under a Creative Commons Attribution-NonCommercial 4.0 International License , except where otherwise noted.Download for free at: https://openoregon.pressbooks.pub/wrd/	937	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Nursing/The_Scholarship_of_Writing_in_Nursing_Education_(Lapum_et_al.)/09%3A_Academic_Integrity_and_Style_Rules_(APA_6th_edition)/9.11%3A_Plagiarism_and_Self-Plagiarism	libretexts	libretexts-0000.json.gz:332	https://med.libretexts.org/Bookshelves/Nursing/The_Scholarship_of_Writing_in_Nursing_Education_(Lapum_et_al.)/09%3A_Academic_Integrity_and_Style_Rules_(APA_6th_edition)/9.11%3A_Plagiarism_and_Self-Plagiarism
G75j0HXgq5unc-fR	6.6E: Exponential and Logarithmic Equations (Exercises)	6.6E: Exponential and Logarithmic Equations (Exercises) 38. Solve $216^{3 x} \cdot 216^{x}=36^{3 x+2}$ by rewriting each side with a common base. 39. Solve $\frac{125}{\left(\frac{1}{625}\right)^{-x-3}}=5^{3}$ by rewriting each side with a common base. 40. Use logarithms to find the exact solution for $7 \cdot 17^{-9 x}-7=49$. If there is no solution, write no solution. 41. Use logarithms to find the exact solution for $3 e^{6 n-2}+1=-60$. If there is no solution, write no solution. 42. Find the exact solution for $5 e^{3 x}-4=6$. If there is no solution, write no solution. 43. Find the exact solution for $2 e^{5 x-2}-9=-56$. If there is no solution, write no solution. 44. Find the exact solution for $5^{2 x-3}=7^{x+1}$. If there is no solution, write no solution. 45. Find the exact solution for $e^{2 x}-e^{x}-110=0$. If there is no solution, write no solution. 46. Use the definition of a logarithm to solve. $-5 \log _{7}(10 n)=5$. 47. Use the definition of a logarithm to find the exact solution for $9+6 \ln (a+3)=33$. 48. Use the one-to-one property of logarithms to find an exact solution for $\log _{8}(7)+\log _{8}(-4 x)=\log _{8}(5)$. If there is no solution, write $n o$ solution. 49. Use the one-to-one property of logarithms to find an exact solution for $\ln (5)+\ln \left(5 x^{2}-5\right)=\ln (56)$. If there is no solution, write no solution. 50. The formula for measuring sound intensity in decibels $D$ is defined by the equation $D=10 \log \left(\frac{I}{I_{0}}\right),$ where $I$ is the intensity of the sound in watts per square meter and $I_{0}=10^{-12}$ is the lowest level of sound that the average person can hear. How many decibels are emitted from a large orchestra with a sound intensity of $6.3 \cdot 10^{-3}$ watts per square meter? 51. The population of a city is modeled by the equation $P(t)=256,114 e^{0.25 t}$ where $t$ is measured in years. If the city continues to grow at this rate, how many years will it take for the population to reach one million? 52. Find the inverse function $f^{-1}$ for the exponential function $f(x)=2 \cdot e^{x+1}-5$. 53. Find the inverse function $f^{-1}$ for the logarithmic function $f(x)=0.25 \cdot \log _{2}\left(x^{3}+1\right)$.	462	common-pile/libretexts_filtered	https://math.libretexts.org/Bookshelves/Algebra/Algebra_and_Trigonometry_1e_(OpenStax)/06%3A_Exponential_and_Logarithmic_Functions/6.06%3A_Exponential_and_Logarithmic_Equations/6.6E%3A_Exponential_and_Logarithmic_Equations_(Exercises)	libretexts	libretexts-0000.json.gz:12991	https://math.libretexts.org/Bookshelves/Algebra/Algebra_and_Trigonometry_1e_(OpenStax)/06%3A_Exponential_and_Logarithmic_Functions/6.06%3A_Exponential_and_Logarithmic_Equations/6.6E%3A_Exponential_and_Logarithmic_Equations_(Exercises)
B5vUUA6h_Y6rcN_h	12.2: Examples	12.2: Examples A Croquet player hits a wooden croquet ball, of mass $m=0.450$ kg, at a speed of $v_0=3.5$ m/s, which collides, off-center, with a stationary ball of the same mass. After the collision, the first ball moves off with a speed of $v_1=3.0$ m/s at an angle of $\theta_1=10^{\circ}$ with respect to the x-axis, as shown in the figure. You may assume that this collision is inelastic. - At what angle, $\theta_2$, relative to the x-axis does the second ball move away from the collision at? - What is the final speed of the second ball, $v_2$? - What was the change in energy of this collision? Can you explain your answer? A billiard ball moving at 3.06 m/s strikes a second billiard ball, of the same mass (150 g) and initially at rest, in a perfectly elastic collision. After the collision, the first ball moves away with a speed 2.65 m/s. - What is the initial kinetic energy of the system? - What is the final speed of the second ball? - If the first ball leaves the collision at an angle of 30$^\circ$ with respect to the original direction of motion, what angle does the second ball leave the collision at? I am responsibly driving my 1360-kg Subaru Impreza through an intersection. I am traveling west, my light is green, so I proceed through at 45 mph. An irresponsible driver in a brand new Audi R8 (of mass 1678 kg) with Florida plates blows through the red light going north. He smashes into me, and our cars stick together after the collision, traveling at an angle of 65$^\circ$ north of west. - Determine both (which can be done in either order), - How fast was he traveling before he hit me? - How fast are the two cars moving together after the collision? - What fraction of the total energy of the system was lost during this collision? You are flying through empty space in your rocket, at 2000 m/s, far away from any stars, planets, or other massive bodies. However, you aren't paying very careful attention so you don't notice that there is a giant cube of ``Space-goo'' on a collision course with you! It is moving at a speed of 500 m/s in a direction perpendicular to your own, and has a mass of 3000 kg. Assuming the total mass of you and your personal rocket is 1500 kg, and you get stuck in the space-goo when you collide, what is the magnitude and direction of your final velocity after the collision? Example $\PageIndex{5}$: Collision Graph revisited Look again at the collision graph from Example 2.4.1 from the point of view of the kinetic energy of the two carts. - What is the initial kinetic energy of the system? - How much of this is in the center of mass motion, and how much of is convertible? - Does the convertible kinetic energy go to zero at some point during the collision? If so, when? Is it fully recovered after the collision is over? - What kind of collision is this? (Elastic, inelastic, etc.) What is the coefficient of restitution? Solution (a) From the solution to Example 3.5.1 we know that \begin{aligned} v_{1 i}=&-1 \: \frac{\mathrm{m}}{\mathrm{s}} & & v_{2 i}=0.5 \: \frac{\mathrm{m}}{\mathrm{s}} \\ v_{1 f}=&1 \: \frac{\mathrm{m}}{\mathrm{s}} & & v_{2 f}=-0.5 \: \frac{\mathrm{m}}{\mathrm{s}} \end{aligned} and $m_1$ = 1 kg and $m_2$ = 2 kg. So the initial kinetic energy is \[ K_{s y s, i}=\frac{1}{2} m_{1} v_{1 i}^{2}+\frac{1}{2} m_{2} v_{2 i}^{2}=0.5 \: \mathrm{J}+0.25 \: \mathrm{J}=0.75 \: \mathrm{J} \label{eq:4.17} \] (b) To calculate $K_{cm} = \frac{1}{2} (m_1 + m_2)v^2_{cm}$, we need $v_{cm}$, which in this case is equal to \[ v_{c m}=\frac{m_{1} v_{1 i}+m_{2} v_{2 i}}{m_{1}+m_{2}}=\frac{-1+2 \times 0.5}{3}=0 \nonumber \] so $K_{cm}$ = 0, which means all the kinetic energy is convertible. We can also calculate that directly: \[ K_{\text {conv}, i}=\frac{1}{2} \mu v_{12, i}^{2}=\frac{1}{2}\left(\frac{1 \times 2}{1+2} \: \mathrm{kg}\right) \times\left(0.5 \: \frac{\mathrm{m}}{\mathrm{s}}-(-1) \: \frac{\mathrm{m}}{\mathrm{s}}\right)^{2}=\frac{1.5^{2}}{3} \: \mathrm{J}=0.75 \: \mathrm{J} \label{eq:4.18} \] (c) If we look at figure 2.4.1 , we can see that the carts do not pass through each other, so their relative velocity must be zero at some point, and with that, the convertible energy. In fact, the figure makes it quite clear that both $v_1$ and $v_2$ are zero at $t$ = 5 s, so at that point also $v_{12}$ = 0, and the convertible energy $K_{conv}$ = 0. (And so is the total $K_{sys}$ = 0 at that time, since $K_{cm}$ = 0 throughout.) On the other hand, it is also clear that $K_{conv}$ is fully recovered after the collision is over, since the relative velocity just changes sign: \begin{array}{l} {v_{12, i}=v_{2 i}-v_{1 i}=0.5 \: \frac{\mathrm{m}}{\mathrm{s}}-(-1) \: \frac{\mathrm{m}}{\mathrm{s}}=1.5 \: \frac{\mathrm{m}}{\mathrm{s}}} \\ {v_{12, f}=v_{2 f}-v_{1 f}=-0.5 \: \frac{\mathrm{m}}{\mathrm{s}}-1 \: \frac{\mathrm{m}}{\mathrm{s}}=-1.5 \: \frac{\mathrm{m}}{\mathrm{s}}} \label{eq:4.19} \end{array} Therefore \[ K_{\text {conv}, f}=\frac{1}{2} \mu v_{12, f}^{2}=\frac{1}{2} \mu v_{12, i}^{2}=K_{\text {conv}, i} \nonumber \] (d) Since the total kinetic energy (which in this case is only convertible energy) is fully recovered when the collision is over, the collision is elastic. Using equation (\ref{eq:4.19}), we can see that the coefficient of restitution is \[ e=-\frac{v_{12, f}}{v_{12, i}}=-\frac{-1.5}{1.5}=1 \nonumber \] as it should be.	1,121	common-pile/libretexts_filtered	https://phys.libretexts.org/Courses/Merrimack_College/Conservation_Laws_Newton's_Laws_and_Kinematics_version_2.0/12%3A_C12)_Collisions/12.02%3A_Examples	libretexts	libretexts-0000.json.gz:11430	https://phys.libretexts.org/Courses/Merrimack_College/Conservation_Laws_Newton's_Laws_and_Kinematics_version_2.0/12%3A_C12)_Collisions/12.02%3A_Examples
WurGBT22HCw1a5Ws	Medical Terminology - 2e	Interactive Learning Activity: Label the parts of the digestive system. Interactive Learning Activity: Study digestive system medical terms discussed in this chapter using these flashcards. Interactive Learning Activity: Test yourself on these digestive related terms. Interactive Learning Activity: Test yourself on digestive system terms. Interactive Learning Activity: Using the sample documentation provided, drag the terms on the right to their appropriate spaces within the documentation. Interactive Learning Activity: Using the sample documentation provided, drag the terms on the right to their appropriate spaces within the documentation. Interactive Learning Activity: Practice identifying and defining word parts for terms discussed in this chapter. You can also print this as a Chapter 12 Practice Worksheet and check your answers with this Answer Key PDF.	157	common-pile/pressbooks_filtered	https://openwa.pressbooks.pub/medterm2e/chapter/12-8-digestive-system-learning-activities/	pressbooks	pressbooks-0000.json.gz:82176	https://openwa.pressbooks.pub/medterm2e/chapter/12-8-digestive-system-learning-activities/
C3LW_PUnUUnADq2p	Notes on the Fenland; with A Description of the Shippea Man	Produced by Chris Curnow and the Online Distributed Internet Archive) Transcriber's Note: Minor typographical errors have been corrected without note. Irregularities and inconsistencies in the text have been retained as printed. Words printed in italics are noted with underscores: _italics_. Notes on the Fenland by T. McKENNY HUGHES, M.A., F.R.S., F.G.S., F.S.A. Woodwardian Professor of Geology with A Description of the Shippea Man by ALEXANDER MACALISTER, M.A., F.R.S., M.D., Sc.D. Professor of Anatomy Cambridge: at the University Press 1916 CAMBRIDGE UNIVERSITY PRESS C. F. CLAY, MANAGER London: FETTER LANE, E.C. Edinburgh: 100 PRINCES STREET New York: G. P. PUTNAM'S SONS Bombay, Calcutta and Madras: MACMILLAN AND Co., Ltd. Toronto: J. M. DENT AND SONS, Ltd. Tokyo: THE MARUZEN-KABUSHIKI-KAISHA _All rights reserved_ CONTENTS PAGE GEOGRAPHY OF THE FENLAND 1 SUBSIDENCE OF THE VALLEY OF THE CAM 2 TURBIFEROUS AND ARENIFEROUS SERIES 3 ABSENCE OF ELEPHANT AND RHINOCEROS IN TURBIFEROUS SERIES 6 ABSENCE OF PEAT IN ARENIFEROUS SERIES 6 FEN BEDS NOT ALL PEAT 7 SECTIONS IN ALLUVIUM 7 PEAT; TREES ETC.: TARN AND HILL PEAT; SPONGY PEAT AND FLOATING ISLANDS; BOG-OAK AND BOG-IRON 13 MARL: SHELL MARL AND PRECIPITATED MARL 17 THE WASH: COCKLE BEDS (Heacham): BUTTERY CLAY (Littleport) 18 LITTLEPORT DISTRICT 18 BUTTERY CLAY 19 THE AGE OF THE FEN BEDS 20 PALAEONTOLOGY OF FENS 20 BIRDS 25 MAN 27 DESCRIPTION OF THE SHIPPEA MAN BY PROF. A. MACALISTER 30 GEOGRAPHY OF THE FENLAND. The Fenland is a buried basin behind a breached barrier. It is the "drowned" lower end of a valley system in which glacial, marine, estuarine, fluviatile, and subaerial deposits have gradually accumulated, while the area has been intermittently depressed until much of the Fenland is now many feet below high water in the adjoining seas. The history of the denudation which produced the large geographical features upon which the character of the Fenland depends needs no long discussion, as there are numerous other districts where different stages of the same action can be observed. In the Weald for instance where the Darent and the Medway once ran off higher ground over the chalk to the north, cutting down their channels through what became the North Downs, as the more rapidly denuded beds on the south of the barrier were being lowered. The character of the basin is less clear in this case because it is cut off by the sea on the east, but the cutting down of the gorges _pari passu_ with the denudation of the hinterland can be well seen. The Thames near Oxford began to run in its present course when the land was high enough to let the river flow eastward over the outcrops of Oolitic limestones which, by the denudation of the clay lands on the west, by and by stood out as ridges through which the river still holds its course to the sea--the lowering of the clay lands on the west having to wait for the deepening of the gorges through the limestone ridges. A submergence which would allow the sea to ebb and flow through these widening gaps would produce conditions there similar to those of our fenlands. So also the Witham and the Till kept on lowering their basin in the Lias and Trias, while their united waters cut down the gorge near Lincoln through a barrier now 250 feet high. The basin of the Humber gives us an example of a more advanced stage in the process. The river once found its way to the sea at a much higher level over the outcrops of Jurassic and Cretaceous rocks west of Hull, cutting down and widening the opening, while the Yorkshire Ouse, with the Aire, the Calder and other tributaries, were levelling the New Red Sandstone plain and valleys west of the barrier and tapping more and more of the water from the uplands beyond. The equivalent of the Wash is not seen behind the barrier in the estuary of the Humber, but the tidal water runs far up the river and produces the fertile estuarine silt known as the Warp. The Fenland is only an example of a still further stage in this process. The Great Ouse and its tributaries kept on levelling the Gault and Kimmeridge and Oxford Clays at the back of the chalk barrier which once crossed the Wash between Hunstanton and Skegness. The lowlands thus formed lie in the basin of the Great Ouse which includes the Fenland, while the Fenland includes more than the Fens properly defined, so that things recorded as found in the Fenland may be much older than the Fen deposits. SUBSIDENCE OF THE VALLEY OF THE CAM. During the slow denudation which resulted in the formation of this basin many things happened. There were intermittent and probably irregular movements of elevation and depression. Glacial conditions supervened and passed away. The proof of this may be seen in the Sections, Figs. 1, 2 and 3, pp. 8, 9 and 10. At Sutton Bridge the alluvium has been proved to a depth of 73 feet resting on Boulder Clay. At Impington the Boulder Clay runs down to a depth of 86 feet below the surface level of the alluvium. That means that this part of the valley was scooped out before the glacial deposits were dropped in it, and that the bottom of the ancient valley is now far below sea level. In front of Jesus College, gravel with _Elephas primigenius_ was excavated down to a depth of 30 feet below the street, while in the Paddocks behind Trinity College the still more recent alluvium was proved to a depth of 45 feet, i.e. 16 feet below O.D. These facts indicate a comparatively recent subsidence along the valley, as no river could scoop out its bed below sea level. We need not for our present purpose stop to enquire whether this depression was confined to the line of the valley or was part of more widespread East Anglian movements which are not so easy to detect on the higher ground. From the above-mentioned sections it is clear that the denudation, which resulted in the formation of the basin in the lowest hollow of which the Fen Beds lie, was a slow process begun and carried on long before glacial conditions prevailed and before the gravel terraces were formed. As soon as the sea began to ebb and flow through the opening in the barrier, the conditions were greatly altered and we see the results of the conflict between the mud-carrying upland waters and the beach-forming sea. TURBIFEROUS AND ARENIFEROUS SERIES. The Fen Beds belong to the last stage and, notwithstanding their great local differences, seem all to belong to one continuous series. Seeing then that their chief characteristic is that they commonly contain beds of peat it may be convenient to form a word from the late Latin _turba_, turf or peat, and call them Turbiferous to distinguish them from the Areniferous series which consists almost entirely of sands and gravels. When the land had sunk so far that the velocity of the streams was checked over the widening estuary and on the other hand the tide and wind waves had more free access, some outfalls got choked and others opened; turbid water sometimes spread over the flats and left mud or was elsewhere filtered through rank plant growth so that it stood clear in meres and swamps, allowing the formation of peat unmixed with earthy sediment. Banks are naturally formed along the margin of rivers by the settling down of sand and mud when the waters overflow, as seen on a large scale along the Mississippi, the Po, as well as along the Humber and its tributaries. The effect of a break down of the banks is very different. A great hole is scooped out by the outrush, and the mud, sand and gravel deposited in a fanshape according to its degree of coarseness and specific gravity. A good example of this was seen in the disastrous Mid-Level flood at Lynn in 1862[1] and the more recent outburst near Denver in the winter of 1914-15[2], of which accounts were published in contemporary newspapers. The varied accompanying phenomena can be well studied in the process of warping in Yorkshire or the colmata in Italy. [1] _Times_, _Cambridge Chronicle_, May 31, 1862. [2] _Times_, Jan. 16, 1915. This was a much commoner catastrophe in old times, before the banks were artificially raised, and, as the streams could never get back into their old raised channel, this accounts for the network of ancient river beds which intersect the Fens. The bottom of the Turbiferous alluvium is always, as far as my experience goes, sharply defined. This of course cannot be seen in a borehole or very small section. The surface of the older deposits seems to have been often washed clean either by the encroaching sea or by the upland flood waters. In saying that there is an absence of sand and gravel in the Fen Beds we must be careful not to force this description too far. For when the first encroaching water was washing away any pre-existing superficial deposits the first material left as the base of the Fen Beds must have depended upon the character of the underlying strata, the velocity of the water and other circumstances. This is well seen in the Whittlesea brickpit where an ancient gravel with marine shells rests on the Oxford Clay and over the gravel there creeps the base of the Turbiferous series. It here consists chiefly of white marl which thins out to the left of the section and above becomes full of vegetable matter until it passes up into peat, over which there is a flood-water loam. About a mile west-north-west of Little Downham near Ely, and within a couple of hundred yards of Hythe, the Fen Beds were seen in a deep cut carried close to the gravel hill which here stretches out north into the Fens. They consist at the base of material washed down from the spur of gravel and sand of the Areniferous series against which the Fen Beds here abut. This basement bed is succeeded by beds of silt and peat of no great thickness as they are near the margin of the swamp. When any considerable thickness of the older Areniferous gravels has been preserved, the base of the Turbiferous series is smooth or only gently undulating. But where only small patches or pot-holes of gravel remain, there the top of the clay has been contorted and over-folded so as often to contain irregularly curved pipes and even isolated nests of sand and gravel[3]. The base of the Areniferous gravel must generally have been thrown down upon clay which had been clean cut to an even surface by denudation without any soaking of the surface or isolated heaps of gravel sinking into the clay under alternation of dry and wet conditions, such as would puddle the surface under the heaps and allow the masses of heavy gravel to sink in pipes and troughs. These small outlying patches of gravel are sometimes so little disturbed that we leave them in the Areniferous, whereas they are sometimes so obviously rearranged that we must include them in the Turbiferous series, taking care not to include derivative bones from the older in our list of fossils from the newer series. [3] Cf. _Archaeol. Journ._ Vol. LXIX, No. 274 2nd Ser.; Vol. XIX, No. 2, pp. 205-214. ABSENCE OF ELEPHANT AND RHINOCEROS IN TURBIFEROUS SERIES. The basement beds of the Turbiferous or Newer Alluvial Fen Beds are clearly separated by their stratification from the Areniferous or Older Alluvial Terrace Beds down the sloping margin of which they creep, but there is not anywhere, as far as I am aware, any passage or dovetailing of the Fen Beds into the gravel of the river terraces, while the difference in the fauna is very marked. It is however from such sections as those just described that the erroneous view arose that the Elephant and Rhinoceros occurred in the older Fen Beds. It is true that they have been found under peat in the Fenland, but that is only where the gravel spurs of the Old Alluvial Terraces or Areniferous Series have passed under the newer Fen Beds. I saw the remains of _Rhinoceros tichorhinus_ in the gravel beds belonging to the older or Areniferous Series at Little Downham, and from the base of the gravel in the Whittlesea brickpit I obtained a fine lower molar of _Elephas antiquus_. This was, however, not in the Gravel, but squeezed into the soft surface of the underlying Jurassic Clay. There have never been any remains of Elephant or Rhinoceros found in the Turbiferous series. ABSENCE OF PEAT IN ARENIFEROUS SERIES. It is not easy to realise what the conditions were during the formation of the later Terrace Gravels (Barnwell type), and, if it is a fact, why there was not then, as in later times, a marshy peat-bearing area here and there between the torrential deposits of the upper streams near the foot of the hills and the region where the tide met the upland waters. A few plants have been found in the Barnwell gravel but they are very rare in this series. The older Terrace Gravel (Barrington type) might be expected to furnish evidence of the existence of abundant vegetation if we are right in assigning it to about the age of the peaty deposits overlying the Weybourn Crag. But at present we have no evidence of any such deposit in the Cambridge gravels. Although there are great masses of vegetable matter formed in the swamps of tropical regions, peat is essentially a product of northern climes. Pliny[4] evidently refers to peat as used in Friesland but not as a thing with which he was familiar. [4] Lib. XVI, cap. 1. FEN BEDS NOT ALL PEAT. It must not, however, be imagined that the Fen Beds consist wholly or even chiefly of peat. As we travel north from Cambridge the surface of the alluvium is brown earth for miles and only here and there shows the black surface of peat. The numerous ditches for draining the land confirm this observation, and when we have the opportunity of examining excavations carried down to great depths into the alluvium we usually find only a little peat on the surface or in thin beds alternating with silt and clay and marl. Sometimes, but only sometimes, we have evidence of the growth of peat for a long time, then of the incoming of turbid water leaving beds of clay, then again of the tranquil growth of peat. All this points to changes of local conditions and shifting channels during a gradual sinking of the area, for some of the peat is below sea level. I believe that the volume of clay is much greater than that of peat, although from the common occurrence of peat on the surface and clay in the depth the area over which peat is seen is greater. We have not, however, the data for estimating the proportion of each. In embayed corners along the river even above Cambridge we find little patches of peat, while on the other hand in deep excavations near the middle of the valley we find only thin streaks of peat or peaty silt. In the trial boreholes at the Backs of the Colleges there was only this kind of record of former swamp vegetation. SECTIONS IN ALLUVIUM. In digging the foundations for the chimney of the Electric Lighting Works opposite Magdalene College the following section was seen (Fig. 1, p. 8). Under the new Tennis Courts in Park Parade facing Mid-summer Common the section was somewhat different (Fig. 2, p. 9). While in the pit dug some years ago by Mr Bullock at the other end of the Parade at the lower end of Portugal Place in the south-east corner of the Common there was a section very similar to the last (Fig. 3, p. 10). +------ \| Made ground \| 7'-8' +------ \| Black silt \| 7'-8' +------ \| 4' Peaty silt +------ \| 4' Gravel +------ \| Gault [Illustration: Fig. 1. Section seen in foundations of chimney for Electric Lighting Works near river opposite Magdalene College, July, 1892.] These three sections, immediately north of Cambridge where the valley of the Cam opens out on to the Fens, are important as showing the variations right across the alluvium from side to side and the absence, here at any rate, of any indication of a constant sequence distinctly pointing to important geographical changes. A section seen under Pembroke College Boat House gave 16 feet of clay and peaty silt on the black gravel which here, as in the borings at the Backs of the Colleges, forms the base of the alluvium. About half way down were bones of horse and stag, but I do not believe that these are of any great antiquity, probably not earlier than mediaeval. Thickness Depth +------ \| Irregular made ground 5 \| Clayey \| Alluvium 5 +------ 4 \| Peat 9 +------ 10-12 \| Sand and Gravel 21 +------ 2 \| +------ Gravel 2 \| 25 +------ 4'6" \| Running Sand 29' 6" +------ Gault _Scale_ 8' to 1" [Illustration: Fig. 2. Section seen in digging foundations of Tennis Courts on Midsummer Common, Cambridge.] Lower down the river near Ely a most important and interesting section has recently been exposed. A new bridge was built over the Ouse near the railway station and to obtain material for easing the gradient up to the bridge a pit was sunk close to it on the east side of the river, and was carried down to the Kimmeridge Clay thus giving a clear section through the whole of the alluvium (Fig. 4, p. 11). Depth _a_ \| +------ 4' _b_ \| +------ 7' _c_ \| +------ 10' _d_ \| +------ 12' 6" _e_ \| +------ 13' 2" _f_ \| +------ 21' 2" _g_ \| +------ 23' 2" _h_ \| _a._ Dark clay, with much carbonaceous matter, scattered stones, and freshwater shells 4' 0" _b._ Tough clay 3' 0" _c._ Dark clay full of bits of wood 3' 0" _d._ Light coloured clay full of rootlets 2' 6" _e._ Rusty sand 8" _f._ False bedded gravel and sand pierced by rootlets 8' 0" _g._ Black silt and gravel 2' 0" _h._ Gault 23' 2" ====== [Illustration: Fig. 3. Section seen in Bullock's Pit in S.E. corner of Midsummer Common.] It will be noticed that there is very little peat here and all of it was below O.D. The upper four feet of the clayey peat (_f_) looked as if the vegetable matter had been transported, perhaps from peat beds being destroyed by the river higher up, and been carried down in flood with the clay, while the lower four feet of peat (_h_) was only a cleaner sample of the same, before the river had cut down into the clay. The trees in both _f_ and _h_ were not trees that had grown on the spot and had been blown down, but were broken, water-worn, and evidently transported. _a_ +----------------- _b_ +----------------- _c_ +----------------- _d_ +----------------- _e_ +----------------- _f_ \|················· _g_ +----------------- _h_ \| +----------(1)---- _i_ \| +----------------- _j_ \| +----------(2)---- _a._ Surface soil 7" _b._ Clayey alluvium 7" _c._ Peaty alluvium 9" _d._ Brown clayey alluvium 1' 6" _e._ Peaty alluvium. 9" _f._ Brown clayey peat with trees scattered throughout _g._ and lenticular beds of freshwater shells in it 4' _h._ Peat with trees to 2' diam. 4' _i._ Mottled green and grey clay with lines of sand and gravel giving out water 2' _j._ Yellow clay with springs and much rusty water at bottom. 4' 18' 2" ====== (1) Skull and a few other bones of horse. (2) Broken fragments of bone. _Scale_ 8' to 1" [Illustration: Fig. 4. Section seen in pit dug for material for making up the roadway east of the new bridge over the Ouse by the railway station. Ely, 1910.] If now we travel about 30 miles a little west of north we shall arrive near the shore of the Wash about half way across its southern coast line at Sutton Bridge. Here I had an opportunity of seeing the material of which the alluvium is composed. With a view to securing a sound base for the foundation of the piers of the Midland and Great Northern Railway bridge an excavation was made through the whole of the Fen Beds down to the Boulder Clay which as I have already stated was reached at a depth of 73 feet. The clerk of the works kindly gave me the following measurements (Fig. 5). Depth Thickness +---------- High water (12' 6" above O.D.) 12' 6" \| 12' 6" +---------- Ordnance Datum 4' 0" \| Silt and clay 16' 6" +---------- {\| {+---------- Low water (6' 0" below O.D.) {\| {\| 19' 6"{\| {\| {\| {+---------- Bed of river (17' 6" below O.D.) {\| 36' 0" +---------- 9' 0" \| Sand with shells 45' 0" +---------- 3' 6" \| Loam and sand 48' 6" +---------- 5' 6" \| Ballast with shells 54' 0" +---------- 3' 6" \| Loam with Peat 57' 6" +---------- 3' 6" \| Fine red ballast \| mixed with clay 61' 0" +---------- 5' 0" \| Blue and grey clay \| mixed with sand 66' 0" +---------- 1' 0" \| Ballast 67' 0" +---------- 4' 6" \| Silty Sand 71' 6" +---------- \| Ballast with flint 1' 6" \| and stone 73' 0" +---------- \| Stiff grey clay [Illustration: Fig. 5. Section seen at Sutton Bridge.] Here again we see that the only peat is a bed between three and four feet in thickness of mixed loam and peat more than 40 feet below mean sea level. From these sections it is clear that along the direct and more permanent outfall from Cambridge to the north, peat forms but a small part of the Fen Beds. Peat is a substance of so much value as fuel, of such importance to the agriculturist, of such commercial value in what we may call its by-products, and of such scientific interest in the history of its formation and the remains which its antiseptic properties have preserved, that it has, as might be expected, a large literature of its own. I have before me a list of more than 150 references to peat or to the Fens. PEAT; TREES AND OTHER PLANTS; TARN PEAT AND HILL PEAT; BOG-OAK AND BOG-IRON. When we turn aside into the areas cut off by spurs of gravel and islands of Jurassic rock, we find wide and deep masses of peat which has grown and been preserved from denudation in these embayed and isolated areas. Burwell Fen, for instance, protected on the north and west by the Cretaceous ridge of Wicken and the Jurassic ridge of Upware, furnishes most of the peat used in the surrounding district. If we travel about two miles to the north-west from the pit dug near the railway station (see Fig. 4, p. 11) over the hill on which Ely stands, we shall come to West Fen, where there is a great mass of peat which has grown in a basin now almost quite surrounded by Kimmeridge Clay. In this there is a great quantity of timber at a small depth from the surface. The tree trunks almost all lie with their root-end to the south-west, but some are broken off, some are uprooted, telling clearly a story of growth on the peat which had increased and swelled till the surface was lifted above the level of floods. Then some change--perhaps more rapid subsidence, perhaps changes in the outfalls--let in flood water, the roots rotted and a storm from the south-west, which was the most exposed side and the direction of the prevalent winds, laid them low. The frequent occurrence of large funguses, _Hypoxylon_, _Polyporus_, etc., points to conditions at times unfavourable to the healthy growth of timber. It is worth noting when trying to read the story of the Fens as recorded by their fallen trees that in all forests we find now and then a few trees blown down together though the surrounding trees are left. This may be the result of a fierce eddy in the cycloidal path of the storm, but more commonly it seems to be due to the fact that every tree has its "play," like a fishing rod, and recurring gusts, not coinciding with its rhythm, sometimes catch it at a disadvantage and break or blow it down. The story told by the West Fen trees is quite different from that told by the water-borne and water-worn trunks in the section by Ely station. The same variable conditions prevailed also in the more westerly tracts of the Fen Basin, but the above examples are sufficient for our present purpose. From the large numbers of trees found in some localities and from records referring to parts of the Fens as _forest_ it has sometimes been supposed that the Fens were well wooded, but forest did not generally and does not now always mean a wood, as for example in the case of the deer forests of Scotland. When Ingulph[5] says that portions of the Fenland were disafforested by Henry I, Stephen, Henry II, and Richard, who gave permission to build upon the marshes, this probably meant that they no longer preserved them so strictly, but allowed people to build on the gravel banks and islands in them. [5] _History of Croyland_, Bohn's edition, p. 282. Dugdale, recording a stricter enforcement of game-laws, quotes proceedings against certain persons in Whittlesea, Thorney and Ramsey for having "wasted all the fen of Kynges-delfe of the alders, hassacks and rushes so that the King's deer could not harbour there." He does not mention forest trees. In the growth and accidents of vegetation in a swamp there are some circumstances which are of importance to note with a view to the interpretation of the results observed in the Fens. For instance in fine weather there is a constant lifting and floating of the confervoid algae which grow on the muddy bed of the stream. This is brought about by the development of gas under the sun's influence in the thick fibrous growth of the alga. The little bubbles give it a silvery gleam and by and by produce sufficient buoyancy in the mass to tear it out and make it rise to the surface dropping fine mud as it goes and thus making the water turbid. Other plants, such as Utricularia, Duckweed, etc., have their period of flotation, and in the "Breaking of the Mere" in Shropshire we have a similar phenomenon. In the "Floating Island" on Derwentwater the same sort of thing is seen with coarser plants. All these processes are going on in the meres and in the streams which meander through the Fens and did so more freely before their reclamation. But besides this, when the top of the spongy peat is raised above the water level and dries by evaporation, then heath, ferns and other plants and at last trees grow on it, until accident submerges it all again. This at once shows why we often find an upper peat with a different group of plant remains resting upon a lower peat with plants that grow under water. The most conspicuous examples of these various kinds of peat we see in the mountainous regions of the North and West, where the highest hills are often capped with peat from eight to ten feet in thickness, creeping over the brow and hanging on the steep mountain sides. Sometimes, close by, we see the gradual growth of peat from the margin of a tarn where only water-weeds can flourish. The "Hill Peat" is made up of Sphagnum and other mosses and of ferns and heather. The "Tarn Peat" of conferva, potamogeton, reeds, etc. As Hill Peat now grows on the heights and steeps where no water can stand and Tarn Peat in lakes and ponds lying in the hollows of the mountains and moors, so the changes in the outfalls and the swelling and sinking of the peat have given us in the Fens, here the results of a dry surface with its heather and ferns and trees, and there products of water-weeds only, and, from the nature of the case, the subaerial growth is apt to be above the subaqueous. One explanation of the growth of peat under both of these two very different geographical conditions is probably the absence of earthworms. The work of the earthworm is to drag down and destroy decaying vegetable matter and to cast the mineral soil on to the surface, but earthworms cannot live in water or in waterlogged land, and where there are no earthworms the decaying vegetation accumulates in layer after layer upon the surface, modified only by newer growths. Some years ago a great flood kept the land along the Bin Brook under water for several days and the earthworms were all killed, covering the paddock in front of St John's New Buildings in such numbers that when they began to decompose it was quite disagreeable to walk that way. It reminded me of the effects of storm on the cocklebeds at the mouth of the Medway, where the shells were washed out of the mud, the animals died on the shore and the empty shells were in time washed round the coast of Sheppey to the sheltered corner at Shellness. Here they lie some ten feet deep and are dug to furnish the material for London pathways. In those cases when the storm had passed the earthworms and the cockles came again, but the Hill Peat is always full of water retained by the spongy Sphagnum and similar plants, and the Fens are or were continually, and in some places continuously, submerged and no earthworms could live under such conditions. The blackness of peat and of bog-oak may be largely but certainly not wholly due to carbonaceous matter. Iron must play an important part. There is in the Sedgwick Museum part of the trunk of a Sussex oak which had grown over some iron railings and extended some eight inches or more beyond the outside of the part which was originally driven in to hold the rails. Mr Kett came upon the buried iron when sawing up the tree in his works and kindly gave it to me. From the iron a deep black stain has travelled with the sap along the grain, as if the iron of the rail and the tannin of the oak had combined to produce an ink. The well-known occurrence of bog-iron in peat strengthens this suggestion. An opportunity of observing this enveloping growth of wood round iron railings is offered in front of No. 1, Benet Place, Lensfield Road. The trees in the Fens often lie at a small depth and when exposed to surface changes perish by splitting along the medullary rays. It is not clear how long it takes to impart a peaty stain to bone, but we do find a difference between those which are undoubtedly very old and others which we have reason to believe may be more recent. Compare the almost black bones of the beaver, for instance, with the light brown bones of the otter in the two mounted skeletons in the Sedgwick Museum. MARL. "Marl," as commonly used, is Clay or Carbonate of Lime of a clayey texture or any mixture of these. Beds of shell marl tell the same tale as the peat. Shells do not accumulate to any extent in the bed of a river. They are pounded up and decomposed or rolled along and buried where mud or gravel finds a resting place. Only sometimes, where things of small specific gravity are gathered in holes and embayed corners, a layer of freshwater shells may be seen. But to produce a bed of pure shell marl the quantity of dead shells must be very large and the amount of sediment carried over the area very small, while the margin of the pond or mere in which the formation of such a bed is possible must have an abundant growth of confervoid algae and other water plants to furnish sustenance for the molluscs. Shell marl therefore suggests ponds and meres. Of course it must be borne in mind that in a region of hard water, such as is yielded in springs all along the outcrop of the chalk, there is often a considerable precipitation of carbonate of lime, especially where such plants as Chara help to collect it, as the Callothrix and Leptothrix help to throw down the Geyserite. These beds of white marls, whether due to shells or to precipitation, are thus of great importance for our present enquiry as they throw light on the history of the Fens. We should have few opportunities of examining the marl were it not for its value to the agriculturist. As it consists of clay and lime, it is not only a useful fertiliser but also helps to retain the dusty peat, which when dry and pulverised is easily blown away. Moreover, as the marl occurs at a small depth and often over large areas, it can commonly be obtained by trenching on the ground where it is most wanted. THE WASH. We have now carried our examination of the Fen Beds up to the sea, but to understand this interesting area we must cross the sea bank and see what is happening in the Wash. There is no peat being formed there, nor is there any quantity of drifted vegetable matter such as might form peat. There are marginal forest beds near Hunstanton and Holme, for instance, and it is not clear whether they point to submergence or to the former existence of sand dunes or shingle beaches sufficient to keep out the sea and allow the growth of trees below high water level behind the barrier, such as may be seen at Braunton Burrows, near Westward Ho, or at the mouth of the Somme. What is the most conspicuous character of the Wash is that the upland waters, now controlled as to their outlet, keep open the troughs and deeps while tidal action throws up a number of shifting banks of mud, sand and gravel, many of which are left dry at low water. Along the quieter marginal portions fine sediment is laid down, and relaid when storms have disturbed the surface. On these cockles and other estuarine molluscs thrive. Before the sea banks were constructed these tidal flats extended much further inland. LITTLEPORT DISTRICT. In the light of this evidence let us examine the Fen Beds east of Littleport, a district of great interest not only from its geographical position in relation to the Fens but also from the remains recently discovered there. Looking north and west there is no high ground between us and the Wash. If we could sweep out the soft superficial deposits and abolish the sea banks the tide would still ebb and flow over the whole area. If we look north and east we see the high ground stretching from Downham Market to Stoke Ferry and sweeping round to the south by Methwold and Feltwell and the islands of Hilgay and Southery, thus enclosing a great bay into which the Wissey on the north and the Brandon River on the south deliver the waters collected on the eastern chalk uplands. The island known as Shippea Hill marks the trend of an ancient barrier blocking the northward course of the river Lark. (Fig. 6, p. 29.) Here, then, it seems probable that we might find evidence of a local change from the conditions we now see in the Wash and those which have resulted in the formation of the Fens. BUTTERY CLAY. In deep trenching in the Fen between Littleport and Shippea Hill in order to obtain clay for laying on the peaty surface a very fine unctuous deposit was found at a depth of four or five feet. The overlying Fen Beds were chiefly peat with lenticular beds of white marl and grey clay, obviously laid down from time to time in small depressions in the surface of the peat. This marl was often largely made up of, or was at any rate full of, freshwater shells but sometimes showed evidence of having been gathered on the stems of Chara which on perishing have left small cylindrical hollows penetrating the partly consolidated marl. Under these beds of peat and marl there was the unctuous clay, which is sometimes referred to as the Buttery Clay. It is an estuarine deposit like that mentioned above as occurring in the Wash off Heacham, for instance. It contains shells of _Cardium edule_, _Tellina_ (_Tacoma_) _balthica_, _Scrobicularia piperata_, and other estuarine shells, some of which had the valves adherent or rather adjoining, for the ligament had perished. Mrs Luddington has in her collection the bones of the Urus, Wild Boar and Beaver, obtained from the peat above this Buttery Clay. On the other or south-western side of Shippea Hill, which is an island of Kimmeridge Clay, we get further into the embayed and isolated portions of the Fen and we find more peat in proportion to the other deposits although it is very thin. There are still small lenticular beds of white marl similar to that nearer Littleport and the peat rests upon Buttery Clay of unknown thickness. In this part, however, no shells have yet been noticed. Near Shippea Hill the peat has recently been trenched with a view to obtaining clay with which to dress the surface of the peat and it was here, at a depth of four feet from the surface and four inches above the Buttery Clay, that the human bones described below (pp. 27-35) were found. THE AGE OF THE FEN BEDS. Now we may enquire what are the limits within which we may speculate as to the age of the Fen Beds. These Turbiferous deposits all belong to one stage, though it may be one of long duration. They are sharply separated from the Areniferous deposits, i.e. the sands and gravels of the terraces and spurs which always pass under and, in fairly large sections, can always be clearly distinguished from the resorted layers at the base of the Fen Beds. There is no definite chronological succession which will hold throughout the Fens. The variations observed are geographical--clay, marl, peat, etc., alternating in different order in different localities and subaerial, fluviatile, estuarine, and marine, having only a changing topographical significance. The Fen Beds crept over an area where the underlying formation had been undergoing vicissitudes due to slow geographical changes--changes which, being at sea level and near the conflict of tides and upland water, produced irregular but often important results. There is not in the Fens any _continuous_ record of what took place between the age in which the Little Downham Rhinoceros was buried in the gravel and that in which the Neolithic hunters poleaxed the Urus in the peat near Burwell. PALAEONTOLOGY OF FENS. Nor do we find any constant succession in the fauna and flora in the sections in the Fens any more than we find a uniform distribution of plants and animals over the surface to-day. The most numerous and largest specimens of the Urus I have obtained from near Isleham: the best preserved Beaver bones from Burwell. Modern changes of conditions have limited the district in which the fen fern (_Thelypteris_) or the swallow-tailed butterfly may now be seen; but nature in old times produced as great changes in local conditions as those now due to human agency. When we compare the fauna of the Areniferous Series with that of the Turbiferous, although there is not an entire sweeping away of the older vertebrate and invertebrate forms of life and an introduction of newer, there is a marked change in the whole facies. There is plenty of evidence about Cambridge of the gradual extermination of species still going on. Indeed, I feel inclined to say that there is no such thing as a Holocene age. I remember land shells being common of which it is difficult now to find live specimens, and my wife[6] has shown how the mollusca are being differentiated in isolated ponds left here and there along the ancient river courses above the town. [6] "On the Mollusca of the Pleistocene Gravels in the neighbourhood of Cambridge," by Mrs McKenny Hughes. _Geol. Mag._ Decade 3, Vol. V, No. 5, May 1888, p. 193. But we have not in older beds of the Turbiferous or newer beds of the Areniferous Series any suggestion of continuity between the two. There must have been between them an unrepresented period of considerable duration in which very important changes were brought about. Perhaps it was then that England became an island and unsuitable for most of the life of the Areniferous age. Not only have we in the Turbiferous as compared with the Areniferous Series a change of facies but we have many "representative forms," a point to which that keen naturalist, Edward Forbes, always attached great importance. We have for instance in the Fen Beds the Brown Bear (_Ursus arctos_) with his flat pig-like skull, instead of the Grizzly (_Ursus ferox_) of the Gravels with his broad skull and _front bombé_. If we turn to the horned cattle we shall find a confirmation of the view that there was not an entire break between the Turbiferous and Areniferous fauna for the Urus (_Bos primigenius_) occurs in both. This species became extinct in Britain in the Turbiferous period and before the coming of the Romans, for no trace of it seems to have been found with Roman remains in this country; and indeed when we remember the numerous tribes, the dense population and high civilisation of the natives of Britain in Roman times it seems improbable that they can have tolerated such a formidable beast as this wild bull around their cultivated land. Some confusion has arisen as to the description and the names of the Urus and the Bison. Caesar, who was not a big game hunter and probably never saw either, has given under the name Urus a description which evidently mixes up the characters of both. Both existed on the continent down to quite recent times and the Bison is still found in Poland, but later writers also have evidently confounded them. For instance, the Augsburg picture of the Urus is correct, but Herberstein's, which also is said to represent the Urus, is obviously that of a Bison. I have gone into this question more fully elsewhere[7]. [7] "The Evolution of the British Breeds of Cattle," _Journ. R. Agric. Soc._ Vol. V, Ser. 3, pp. 561-563, 1894. "On the more important Breeds of Cattle which have been recognised in the British Isles in successive periods, and their relation to other archaeological and historical discoveries," _Archaeologia_, Vol. V, Ser. 3, pp. 125-158, 1896. Cf. also Morse, E. W., "The Ancestry of domesticated Cattle," _Twenty-seventh Annual Report of the Bureau of Animal Industry_, 1910, Department of Agriculture, U.S.A. The Urus (_Bos primigenius_) is common in the Fen Beds and is of special importance for our present enquiry, as there is in the Sedgwick Museum a skull of this species found in Burwell Fen with a Neolithic flint implement sticking in it. The implement is thin, nearly parallel sided, rough dressed, except on the front edge which is ground, and it is made of the black south-country flint. It is very different in every respect from the thick bulging implements with curved outlines, which being made of the mottled grey north-country flint or of felstone or greenstone suggest importation from a different and probably more northerly source. This gives us a useful synchronism of peat, a Neolithic implement of a special well-marked type, and the Urus. The Bison is the characteristic ox of the Gravels and never occurs in the Fen Beds; while the Urus, as I have pointed out above, occurs in both the Turbiferous and Areniferous deposits. _Bos longifrons_ is the characteristic ox of the Fen Beds and never occurs in the Gravels. It is the breed which the Romans found here, and we dig up its bones almost wherever we find Roman remains. I cannot adduce any satisfactory evidence that it was wild, that is to say more wild than the Welsh cattle or ponies or sheep which roam freely over wide tracts of almost uninhabited country. This species, like the Urus, has horns pointing forward, but the cattle introduced by the Romans had upturned lyre-shaped horns, as in the modern Italian, the Chillingham or our typical uncrossed Ayrshire breed, and soon we notice the effect of crossing the small native cattle (_Bos longifrons_) with the larger Roman breed. The Horse appears to have lived continuously throughout Pleistocene times down to the present day and to have been always used for food. Unfortunately the skull of a horse is thin and fragile and therefore it has been difficult to obtain a series sufficiently complete to found any considerable generalisations upon it. The animal found in the peat and alluvium appears to have been a small sized, long faced pony. The appearances and reappearances of the different kinds of deer is a very interesting question, but it will be more easily treated when I come to speak of the Gravels of East Anglia. I will only point out now that neither of the deer with palmated antlers properly belongs to the Turbiferous series. The great Irish Elk (_Cervus megacerus_) has not been found in the Fen Beds. Indeed it is not clear that in Ireland it occurs in the peat. The most careful and trustworthy descriptions seem to show that its bones lie either in or on top of the clays on which the peat grew. The other and smaller deer with palmated antlers, namely, the Fallow deer (_Cervus dama_), were reintroduced, probably by the Romans, and although some of them have got buried in the alluvium or newer peat in the course of the 1500 years or so that they have been hunted in royal warrens in East Anglia, they cannot be regarded as indigenous or indicative of climate or other local conditions. Remains of the Red deer (_Cervus elaphus_) and of the Roe deer (_Cervus capreolus_) are common in the Fen Beds; both occur in the Gravels also; and both are still wild in the British Isles. Unlike the Red deer, which lives on the open moorland, the Roe deer lives in woods and forests. And this is an interesting fact in its bearing upon our inferences as to the character of the country before the reclamation of the Fens and the destruction of the plateau forest. The open downs and the spurs and islands of the fenlands offered the Red deer a congenial feeding ground, while the thickets on the edge of the upland forest and the bosky patches along the margins of the lowland swamps provided covert for the Roe deer. Sheep and goat are found in the peat and the alluvium, but it is not easy to tell the age of the bones. They do generally appear to be of that lighter brown colour which is characteristic of remains from newer peat as compared with the black bones which seem to belong to the older and more decomposed peat. The sheep is probably a late introduction and is never found in the Terrace Gravel (see _Geol. Mag._ Decade 2, Vol. X, No. 10, p. 454). The Wild Boar (_Sus scrofa_) is fairly common. It is remarkable that we get very few remains of Wolf, although it is not much more than 200 years since the last was killed. There is in the Sedgwick Museum one fairly complete skeleton, found a long time ago in Burwell Fen and I have recently obtained another from the same locality. There do not seem to be any obvious and constant characters by which we can distinguish a wolf from a dog, and Britain was celebrated for its large and fierce dogs. The bones of the Eskimo dogs are very wolf-like, but they are frequently crossed with wolf. Perhaps the most interesting animal whose remains are found in the Fens is the Beaver. Why do we not find here and there a beaver dam? Perhaps it is because we have not been on the look-out for it, and the peat-cutters would not have seen anything remarkable in the occurrence of a quantity of timber anywhere in the Fens. We must suppose that the peat which often contains whole forests of trees and even canoes would have preserved the timber of the beaver dam. It is an animal too which might have contributed largely towards the formation of the Fens by holding up and diverting meandering streams. Perhaps it did not make dams down in the Fens, and the skeletons we find are those of stray individuals or of dead animals which have floated down from dams near Trumpington or Chesterford; very suitable places for them. We want more evidence about the fen beaver. I have heard that there are beavers in the Danube which do not make dams, but among those introduced into this country in recent years the dam building instinct seems to have survived the change. The beavers on the Marquis of Bute's property in Scotland cut down trees and built dams as did the beavers in Sir Edmund Loder's park in Sussex, and even in the Zoological Gardens they recently constructed a "lodge." We have not found the beaver in the Gravels. Part of the skull of a Walrus was brought to us a long time ago and said to have been found in the peat. But it is a very suspicious case. It does not look like a bone that had been long entombed in peat, and we are not so far from the coast as to make it improbable that it was carried there by some sailor returning home from northern seas. Bones of Cetaceans are thrown up on the shore near Hunstanton, and Seals are still not uncommon in the Wash, so that we need not attach much importance to the occurrence in marine silt of Whale, Grampus, Porpoise, and such like. BIRDS. We have paid much attention to the birds of the Fens, partly because of the occurrence of some unexpected species, and also because of the absence, so far as our collection goes, of species of which we should expect to find large numbers. Perhaps the most interesting are the remains of Pelican (_P. crispus_ or _onocrotalus_)[8]. Of this we have two bones, not associated nor in the same state of preservation. The determination we have on the authority of Alphonse Milne Edwards and Professor Alfred Newton. One of the bones is that of a bird so young that it cannot have flown over but shows that it must have been hatched or carried here. [8] _Annales des Sciences Naturelles, Zool._ (5), Vol. VIII, Pl. 14, pp. 285-293. _Ibis_, 1868, pp. 363-370, _Proc. Zool. Soc._ 1868, p. 2. _Trans. Norfolk and Norwich Naturalists Soc._ Vol. VII, Pt. 2, 1901. _Geol. Mag._ No. 447, N.S. Dec. 4, Vol. VIII, No. 9, p. 422. Of the Crane (_Grus cinerea_) we have a great number of bones but of the common Heron not one. I have placed a recent skeleton of heron in the case to help us to look out for and determine any that may turn up. Bones of the Bittern (_Botaurus_ or _Ardea stellaris_) are quite common, as are those of the Mute or tame Swan (_Cygnus olor_) as well as of the Hooper or wild Swan (_Cygnus musicus_ or _ferus_). Goose (_Anser_) and Duck (_Anas_) are not so numerous as one might have expected. The Grey Goose (_Anser ferus_) and the Mallard (_Anas boscas_) are the most common, but other species are found, as for instance _Anas grecca_. We have also the Red Breasted Merganser (_Mergus serrator_), and the Smew (_Mergus albellus_), the Razor Bill (_Alea tarda_), the Woodcock (_Scolopax rusticola_), the Water Hen (_Gallinula chloropus_) and a few bones of a Limicoline bird, most likely a lapwing. We have found the skull, but no more, of the White-tailed or Sea Eagle (_Haliaetus albicilla_). The whole is a strangely small collection considering all the circumstances. We find in the Fens of course everything of later date, down to the drowned animals of last winter's storm, or the stranded pike left when the flood went down. It is a curious fact and very like instinct at fault that in floods the pike wander into shallow water and linger in the hollows till too late to get back to the river, so that large numbers of them are found dead when the water has soaked in or evaporated. An old man told me that he well remembered when pike were more abundant they used to dig holes along the margin when the flood was rising and when it went down commonly found several fine pike in them. This explains why we so often find the bones of pike in the peat, but where did the pike get into a habit so little conducive to the survival of the species? Although we notice at the present day a constant change in the mollusca, their general continuity throughout the long ages from pre-glacial times is a very remarkable fact. The presence of _Corbicula fluminalis_ and _Unio littoralis_ in the Gravels characterized by the cold-climate group of mammals such as _Rhinoceros tichorhinus_ and _Elephas primigenius_, the absence of those shells from the deposits in which _Rh. merckii_ and _E. antiquus_ are the representative forms, and their existence now only in more southern latitudes, as France, Sicily or the Nile, but not in our Turbiferous Series, lay before us a series of apparent inconsistencies not easy of explanation. MAN. Every step in the line of enquiry we have been following, from whatever point of view we have regarded the evidence, has forced upon us the conclusion that a long interval elapsed between the Areniferous and Turbiferous series as seen in the Fens; and yet, having regard to the geographical history of the area with which we commenced, we cannot but feel that the various deposits represent only episodes in a continuous slow development due to changes of level both here and further afield and the accidents incidental to denudation. But the particular deposits which we are examining happen to have been laid down near sea level where small changes produce great effects. We may feel assured that over the adjoining higher ground the changes would have been imperceptible when they were occurring and the results hardly noticeable. If the Fen Beds include nearly the whole of the Neolithic stage the idea that glacial conditions then prevailed over the adjoining higher ground is quite untenable. So far everything has taught us that the Fens occupy a well-defined position in the evolution of the geographical features of East Anglia and also that the fauna is distinctive, and, having regard to the whole facies, quite different from that of the sands and gravels which occur at various levels all round and pass under the Turbiferous Series of the Fens. We will now enquire what is the place of these deposits in the "hierarchy" based upon the remains of man and his handiwork. No Palaeolithic remains have ever been found in the Fen deposits. We must not infer from this that there is everywhere evidence of a similar break or long interval of time between the Palaeolithic and Neolithic ages. There are elsewhere remains of man and his handiwork which we must refer to later Palaeolithic than anything found in the Areniferous Series just near the Fen Beds, and there are, not far off, remains of man's handiwork which appear to belong to the Neolithic age, but to an earlier part of it than anything yet found in association with the Fen Beds. The newer Palaeolithic remains referred to occur chiefly in caves and the older Neolithic objects are for the most part transitional forms of implement found on the surface in various places around but outside the Fens and in the great manufactures of implements at Cissbury and Grimes Graves, in which we can study the embryology of Neolithic implements and observe the development of forms suggested by those of Palaeolithic age or by nature. The sequence and classification adopted in these groups, both those of later Palaeolithic and those of earlier Neolithic age, are confirmed by an examination of the contemporary fauna; the Areniferous facies prevailing in the caves and the Turbiferous facies characterising the pits and refuse-heaps of Cissbury and Grimes Graves. It is interesting to note that these ancient flint workings, in which we find the best examples of transitional forms, have both of them some suggestion of remote age. The pits from which the flint was procured at Cissbury are covered by the ramparts of an ancient British camp and the ground near Grimes Graves has yielded Palaeolithic implements _in situ_ in small rain-wash hollows close by--as seen near "Botany Bay." Palaeolithic man came into this area sometime after the uplift of East Anglia out of the Glacial Sea and was here through the period of denudation and formation of river terraces which ensued and the age of depression which followed. But Neolithic man belongs to the later part of that period of depression when the ends of some of the river gravels were again depressed below sea level and the valleys had scarcely sufficient fall for the rivers to flow freely to the sea. In the stagnant swamps and meres thus caused the Fen deposits grew, and in this time the Shippea man met his death mired in the watery peat of the then undrained fens. Human bones have not been very often found in the Fen, and when they do occur it is not always easy to say whether they really belong to the age of the peat in which they are found or may not be the remains of someone mired in the bog or drowned in one of the later filled up ditches. That they have long been buried in the peat is often obvious from the colour and condition of the bone. By the kindness of our friends Mr and Mrs Luddington my wife and I received early information of the discovery of human bones in trenching on some of their property in the Fen close to Shippea Hill near Littleport and we were able to examine the section and get some of the bones out of the peat ourselves (Fig. 6). A deposit of about 4' 6" of peat with small thin lenticular beds of shell marl here rested on lead colored alluvial clay. In the base of the peat about four inches above the Buttery Clay a human skeleton was found bunched up and crowded into a small space, less than two feet square, as if the body had settled down vertically. _b_ +-----+ / \ [Greek: ph] --------------/ \-------------- _c_ ···_d_ / \ _d´_··· _c_ / \ + -----------/ _a_ \----------- _e_ / \ _e´_ ---------+-------------------+--------- _a._ Kimmeridge Clay forming Shippea Hill, on which monastic buildings in connection with Ely Cathedral formerly stood. _b._ Patches of rusty flint gravel. _c._ Peat with bones of beaver, boar, urus, etc. _d._ Shell Marl, occurring in lenticular beds of limited extent in the upper part of the peat, sometimes in one bed as at _d_ and sometimes in several distinct beds as at _d´_. _e._ "Buttery Clay"; full of cockleshells etc. at _e_, but at _e´_ containing only freshwater shells and pieces of wood. + Position of skeleton. [Greek: ph] Dressed flint flake on surface. [Illustration: Fig. 6. Diagram Section across Shippea Hill.] Some of the bones were broken and much decayed, while others, when carefully extracted, dried and helped out with a little thin glue, became very sound and showed by the surface markings that they had suffered only from the moisture and not from any wear in transport. The most interesting point about them is the protuberant brow, which, when first seen on the detached frontal bone, before the skull had been restored, suggested comparison with that of the Neanderthal man. Much greater importance was attached to that character when the Neanderthal skull was found. When I announced the discovery of the Shippea man the point on which I laid most stress was that, notwithstanding his protuberant brow, he could not possibly be of the _age_ of the deposits to which the Neanderthal man was referred. I stated "my own conviction that the peat in which the Shippea man was found cannot be older than Neolithic times and may be much newer" and, believing that similar prominent brow ridges are not uncommon to-day, I suggested that he might be even as late as the time of the monks of Ely who had a Retreat on Shippea Hill. The best authorities who have seen the skull since it has been restored by Mr C. E. Gray, our skilful First Attendant in the Sedgwick Museum, refer it to the Bronze Age which falls well within the limits which I assigned. This skull is unique among the few that I have obtained from the Fens. Dr Duckworth has described[9] most of these, and I subjoin a description of the Shippea man by Professor Alexander Macalister. [9] Duckworth and Shore, _Man_, No. 85, 1911, pp. 134, 139. DESCRIPTION OF THE SHIPPEA MAN BY PROF. A. MACALISTER. "The calvaria is large, dark coloured and much broken. The base, facial bones and part of the left brow ridge and glabella are gone. The sutures are coarsely toothed and visible superficially although ankylosis has set in in the inner face. The bone is fairly thick (8·10 mm.), and on the inner face the pacchionian pits are large and deep on each side of the middle line especially in the bregmatic part of the frontal and the post-bregmatic part of the parietals. The superior longitudinal groove is deep but narrow, and, as far as the broken condition allows definite tracing, the cerebral convolution impressions are of the typical pattern. [Illustration: Fig. 7.] "The striking feature is the prominent brow ridge due to the large frontal sinus. The glabella was probably prominent and the margins on each side are large and rough and extend outwards to the supraorbital notches. The outer part of the supraorbital margin and the processus jugalis are thick, coarse and prominent (Fig. 7). "In norma verticalis the skull is ovoid-pentagonoid euryme-topic with conspicuous rounded parietal eminences, slight flattening at the obelion and a convex planum interparietale below it (Fig. 8). [Illustration: Fig. 8.] "In norma lateralis the brow ridges are conspicuous; above them is the sulcus transversus from which the frontal ascends with a fairly uniform curve to the bregma. The frontal sagittal arc above the ophryon measures 112 mm. and its chord 116. Behind the bregma the parietals along the front half of the sagittal suture have a fairly flat outline to the medio-parietal region, behind which the flattened obelion is continued downwards with a uniform slope to the middle of the planum interparietale whence it probably descended by a much steeper curve to the inion, which is lost. The parietal sagittal arc, including the region where there was probably a supra-lambdoid ossicle, was about 140 mm. and its chord 121 but the curve is not uniform. "In norma occipitalis the sagittal suture appears at the summit of a ridge whose parietal sides slope outwards forming with each other an angle of 138°, as far as the parietal eminences. From these the sides drop vertically down to the large mastoid processes. The intermastoid width at the tips of the processes is 115, but at the supramastoid crest is 148 (Fig. 9). [Illustration: Fig. 9.] "In norma frontalis the conspicuous feature is the brow ridge. This gives a kind of superficial suggestion of a Neanderthaloid shape, but the broad and well arched frontal dispels the illusory likeness. The jugal processes jut out giving a biorbital breadth of 115 mm. while the least frontal width is 97 and the bistephanic expands to 125. There is a slight median ridge on the frontal ascending from the ophryon, at first narrow but expanding at the bregma to 50 mm. The surface of this elevated area is a little smoother than that of the bone on each side of it. "The other long bones are mostly broken at their extremities. The femora are strong and platymeric. The postero-lateral rounded edge, which bears on its hinder face the insertion of the gluteus maximus, taken in connexion with the projection of the thin medial margin of the shaft below the tuberculum colli inferior causes the upper end of the shaft to appear flattened. The index of platymeria is ·55. The femoral length cannot have been less than 471 mm. The man was probably of middle stature, not a giant as was the Gristhorpe man. The tibiæ are also broken at their ends, they are eurycnemic (index ·80) with sharp sinuous shin and flat back, the length may have been between 335 and 340 mm. The humeri are also bones with strong muscular crests, and the ulnæ are smooth and long. The fibula was channelled. There is nothing in the bone-features which is inconsistent with the reference of the skull to the Brachycephalic Bronze Age race. [Illustration: Fig. 10.] "In the following Table are recorded the measurements of the different regions. The two crania which I have selected to compare with it are (1) a Round-barrow skull from near Stonehenge (No. 179 in our Collection) and (2) the Gristhorpe skull, to both of which it bears a very strong family likeness. Shippea Stonehenge Hill (No. 179) Gristhorpe Maximal length 194 185 192 Maximal breadth 153 153 156 Auricular height 135 132 133 Biorbital width 115 112 117 Bistephanic width 128 132 133 Least frontal width 97 103 106 Biasterial 120 127 125 Auriculo-glabellar radius 116 113 114 Auriculo-ophryal radius 113 111 105 Auriculo-metopic radius 134 127 124 Auriculo-bregmatic radius 137 132 134 Auriculo-lambdoid radius 104 102 115 Length and breadth index 78·87 82·7 81·25 "The resemblance to the two Round-barrow skulls of the Bronze Age is too great to be accidental, so we may regard this as a representative of that race, possibly at an earlier stage than the typical form of which the two selected specimens are examples (Fig. 10). "The mandible also resembles that of the Gristhorpe skull in general shape of angle and prominence of chin. "The measurements are as appended: Shippea Stonehenge Hill (No. 179) Gristhorpe Condylo mental length 131 -- 130 Gonio mental length 100 -- 99 Bigoniac 115 -- 116 Bicondylar 139 -- 141 Chin height 32 -- 33" Cambridge: PRINTED BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS	18,668	common-pile/project_gutenberg_filtered	43597	project gutenberg	project_gutenberg-dolma-0007.json.gz:1053	https://www.gutenberg.org/ebooks/43597.txt.utf-8
6jaVo62JZFANgzN7	Literature Reviews for Education and Nursing Graduate Students	Chapter 6: Documenting Sources Learning Objectives At the conclusion of this chapter, you will be able to: - Select a citation management system that works for you - Record and organize relevant material in a citation management system 6.1 Overview of documenting sources A graduate-level literature review is a significant undertaking and will require some decisions about information organization, record-keeping, and notes management. Make these decisions before you begin your intensive review of the literature. Some of the decisions you will need to make include things like document-naming conventions, choosing a citation management tool that fits your needs, and setting up journal alerts. Once you have identified and located materials for your literature review, you will organize, analyze, and synthesize them as the next step in literature review process. Here are some general guidelines for how you treat the articles at this stage: - Skim the articles as you gather them to get an idea of the general purpose and content. Focus on the abstract, introduction, first few paragraphs, and the conclusion. - Record notes and impressions on the article directly in the citation management tool you choose. Record specific aspects or significant keywords of the article that are relevant to your review. General remarks, such as ‘good source’ or ‘interesting idea,’ won’t help you later on. - Pay special attention to major trends or patterns, possible gaps in the literature, and relationships among studies, especially noting or highlighting landmark studies that led to subsequent ones in the same area. - Group the articles into categories or folders, such as topics and subtopics. Also group articles that you have placed within these categories chronologically. You can print out each article and organize the paper copies into categories or you take advantage of technology by using citation management software to store and organize your articles. Begin to group sources into broad categories and then organize chronologically or alphabetically by author’s last name. Broad general categories might include: - Themes or Concepts - Theories - Policies - Programs - Populations - Methodologies - Questions for further research Other broad organization schemes might relate to the PICO or SPICE models mentioned in Chapter 3. We will discuss organization and synthesis in more detail in Chapter 7. - Develop a standardized naming convention for folders and files. Names should be kept as short as possible whilst also being meaningful, concise, and standardized. For example, PolicyCttee2017 or GuidelinesRegulationsHarrison is more useful than LitReviewArticle1. Other useful file naming conventions can be found The University of Edinburgh Records Management Office (2017). Examples include: - Avoid unnecessary repetition and redundancy in file names and file paths. - Use capital letters to delimit words, not spaces or underscores - When including a personal name in a file name give the family name first followed by the initials. - Avoid using common words such as ‘draft’ or ‘letter’ at the start of file names, unless doing so will make it easier to retrieve the record. - Order the elements in a file name in the most appropriate way to retrieve the record. - Avoid using non-alphanumeric characters in file names. Take the time to think about your organizational system before you begin researching and compiling sources in earnest. “Organizing now will save much time and heartache later.” (Machi & McEvoy, 2012, p. 31). 6.2 Citation Management Tools One of your first decisions – after selecting your topic – will be to determine which citation manager will work the best for you. Citation managers are software packages, such as EndNote or Zotero, used to create personalized databases of citations and notes. Citation management tools help users: - import citations from databases, websites, and library catalogs - create bibliographies - format citations in a variety of styles such as APA, MLA, Chicago, and more - manage, categorize, and organize citations and documents - attach PDFs, images, and notes to citations in your collection. While most current citation managers are generally similar, individual workflow may determine which tool to use. For example, if you will be working from multiple computers and locations, a web-based tool such as RefWorks and Mendeley will work better for you than a client-based or centrally hosted website. Other needs to consider when evaluating different citation managers: - I need to work offline. - I’ll be doing a lot of my research on freely available websites and need to be able to save copies of webpages. - I’m working on a group project and need to share my references with others. - I’m not so comfortable with technology and may potentially need a lot of help with my tool. - I will be working on a mobile device. 6.2.1 Tips for choosing the right tool There are many tools to choose from and you want to experiment with a few as well as discuss with professional colleagues, fellow students, or faculty before making a final decision on which to use. Choosing a tool ultimately depends on your personal workflow preferences and your needs. General tips for choosing the right citation management tool: - Consult Wikipedia’s detailed and updated comparison chart of citation management tools to determine if any tool is clearly the best fit for you. - Talk to people in your department. Do individuals in your discipline tend to use one tool more often than another? Does your department or university already provide access to a specific tool? - Talk to your subject librarian; s/he can recommend a tool based on your needs. - Critically assess your technology skills and interests. Although all the tools advertise ease of use, there is a learning curve. Take a look at the free tutorials, help documents, and instruction manuals and rate your level of understanding and confidence. Choose your citation management tool carefully. Try some out. Talk to colleagues. Once you’ve chosen a tool and started using it, changing to a different tool is problematic on several levels. If you save citations in two different products, it can be difficult to keep track of citations. Learning a new product or migrating information from one citation tool to another when you are in the middle of a project can also be difficult, time-consuming, and stressful. Choose carefully, but do choose and then stick with it. 6.2.2 Alerts Alerts are an excellent way to keep up with the literature of your discipline. Alerts allow you to stay up to date with current research relevant to your topic. Once an alert is set up, you will automatically receive an email when an author’s publication, keywords, affiliations, or other search criteria appear in a database. You will be able to connect to the citation, download the citation and full text (when available) from the alert, and (if relevant) save to your citation manager. Alerts are a way to save time AND stay up-to-date in your topic area. <IP_ADDRESS> Why use alerts? - Do you ever feel overwhelmed by the amount of time it takes to stay aware of the latest research and trends in your discipline? - Do you have so many articles and journals in your “to read” pile that they end up being irrelevant by the time you get to them? - Do you have a due date for your literature review, but can’t find time to check back for the latest updates on the topic? If you answered yes to any of these questions, note that a number of database aggregators like ProQuest and EBSCO, as well as individual databases, such as ERIC and CINAHL, offer free alert services informing you of new journal issues, recently published articles related to your interests, and more. Most databases and journals use e-mail alerts to inform users of new content. Many researchers set up alerts through Google Scholar. For tips on how to set up alerts in Google Scholar, see the help page at: https://scholar.google.com/intl/en/scholar/help.html#alerts <IP_ADDRESS> Types of alerts - Table of Contents (TOC) Alerts – These alerts inform users about new journal issues. Depending on the database and your preferred method of delivery, you will receive a table of contents for the issue or links to the full-text articles. Most TOC alerts are delivered via email, but they can also be subscribed to via RSS. A directory of thousands of current and scholarly TOCs is browsable at http://www.journaltocs.hw.ac.uk/. For a short 2 minute tutorial on how to set up journal alerts through PubMed, see https://www.nlm.nih.gov/bsd/viewlet/myncbi/jourup/index.html - Saved Searches – A saved search alert will notify you when the database identifies new articles related to a customized search. You can specify how often you would like to receive updates (weekly, monthly, etc.). - Citation Alerts – These alerts will inform you when a specified article is cited in a new publication. Within your citation manager, you can set up custom folders to not only store new articles but also to share both alerts and articles with colleagues or fellow students researching similar topics. 6.3 Bibliographic citation format Once you begin gathering sources for your literature review, you will need to organize and document them. Citations document the source of an idea, statement, or study. A uniform citation style helps both the reader and the writer. A standardized editorial style removes the distraction and confusion of puzzling over the correct punctuation for every reference or the proper formatting for numbers and other data in text. Those elements are codified in the rules of the format style, allowing the reader to focus energy on the substance of the research, rather than how the paper is constructed. An author writing for publication must follow the rules established by the publisher to avoid inconsistencies. Without established rules of style, each manuscript might use different spellings, notations, and citations, which would confuse and distract readers. The need for a consistent style becomes more apparent and more visible when complex material is presented, such as tables or statistics. Without standardized rules for presentation of data, the reader would spend too much time and energy looking for meaning among the structure. Likewise, a systematic and standardized bibliographic citation format helps the writer of the literature review keep track of references as they accumulate and find them more efficiently later in the process. “You will be rewarded for your hard work, if not in heaven, then certainly when you come to write your report. You will be able to locate information easily, to regroup and reclassify evidence and to produce referenced quotations to support your arguments.” (Bell, 2005, p. 74). There are numerous different bibliographic citation format styles. APA (American Psychological Association), MLA (Modern Language Association), Chicago, Turabian, ACS (American Chemical Society), AMA (American Medical Association) , and IEEE (Institute of Electrical and Electronic Engineers) are some of the more common formats in use, but there are many more. The different styles, and different versions within each style, are a source of stress for generations of students and researchers in all disciplines, including those in the health sciences and education. In the social sciences, APA style is frequently used as the default citation style. Your department or discipline may require another format and, if so, that is the one you should accustom yourself with using to document your sources. As there are over a dozen different citation styles and different disciplines prefer different styles, always check to see if your instructor requires a particular style. Also because the rules for citation styles can change and can be extensive, it is best to refer to the official handbooks/style guides when you can. (Teaching & Learning, 2015, p. 6). Whatever citation style and format you decide to use, now is the time to make that decision. Consistently documenting your sources as you read is another way to plan and organize information as you go along, rather than at the end or in the middle. In addition to print and online manuals detailing the specifics of each citation style, there are numerous websites and other resources that provide document citation formatting help. The Online Writing Lab (OWL) at Purdue University, for example, can answer most questions about APA, MLA, and Chicago style. University writing labs and subject specialist librarians may also help with correctly documenting sources and formatting style. A useful open resource for graduate students in the social sciences is Professional Writing in the Health Disciplines by Sandra Collins (2016). In addition to discussing how to structure a graduate-level paper, a chapter on APA citation and reference formatting provides extensive detail on how to document sources. Additionally, Choosing & Using Sources: A Guide to Academic Research (Teaching & Learning, 2015) provides examples and advice for documenting sources using APA style formatting. Practice - Review a short introductory tutorial or brochure from each of these 4 citation management tools: - Decide which citation management tool you are going to use and request a free trial or download/install a free version to test. - Using the JournalTOCs website (www.journaltocs.hw.ac.uk), create an account, locate a journal in your topic area, and set up an email alert. Test Yourself See the Answer Key for the correct response. QUESTION 1 – Choose a good folder and file naming convention: - MyLitReview/Miscellaneous1 - RandomTheories/Supporting - Guidelines/State - Regulations/OtherStuff QUESTION 2 – The advantage of choosing and using a citation management program is: - import citations from databases, websites and library catalogs with a few clicks - create bibliographies in APA style - format citations in APA style - manage, categorize and organize citations - attach PDFs, images and other files to citations - add notes, highlight text, share with colleagues - all of the above QUESTION 3 – In APA style documentation, what is the correct in-text, parenthetical format for a direct quotation? - (Barrett, 1991, p. 17) - (Barrett, p. 17, 1991) - (Barrett : 17) - (M.P. Barrett [1991]: 17) QUESTION 4 – For journal articles included in the References list, does citation 1 or citation 2 use the correct APA format style: - Poortman, Ann-Rigt. “How Work Affects Divorce: The Mediating Role of Financial and Time Pressures.” Journal of Family Issues 26.2 (2005): 168-180. - Poortman, A. (2005). How work affects divorce: The mediating role of financial and time pressures. Journal of Family Issues 26(2), 168-180. QUESTION 5 – Select the answer that best describes the function of the reference page - Sources cited in the paper must appear on the reference page in alphabetical order. - Books and articles read, but not cited in the paper, should be included on the reference page. - Videos and blogs should be cited in the paper, but not included on the reference page. - Sources listed on the reference page do not need to be cited within the paper. For more practice deciphering APA citations, see the self-test exercises in Choosing & Using Sources.	3,203	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/literaturereviewsedunursing/chapter/chapter-6-documenting-sources/	pressbooks	pressbooks-0000.json.gz:19770	https://ecampusontario.pressbooks.pub/literaturereviewsedunursing/chapter/chapter-6-documenting-sources/
R7Sso51O0PsHmRkF	A Great Marketing Textbook	1.4 The Marketing Concept Learning Objectives You’re probably very skilled at recognizing the signs of marketing. We’ve all had the experience of being on the receiving or customer end of marketing efforts—whether through advertising or sales tactics. In this section you’ll get to understand the marketing orientation, or marketing concept, from the standpoint of setting priorities and doing business. You’ll learn that the marketing orientation is a mindset grounded in one thing: knowing and satisfying the customer. Not all businesses follow a marketing orientation, however—some are focused on other priorities, such as product and production. In this section you’ll see what sets the marketing concept apart. - Reading: The Marketing Concept	144	common-pile/pressbooks_filtered	https://pressbooks.pub/agreatmarketingtextbook/chapter/outcome-marketing-concept/	pressbooks	pressbooks-0000.json.gz:37330	https://pressbooks.pub/agreatmarketingtextbook/chapter/outcome-marketing-concept/
q2nTN68c3omZqpkL	Oklahoma Brunken Cousins	Family lore I heard as a child has that our great-grandfather, Carsten Petersen, Sr., after the death of his first wife, placed his children with relatives and neighbor families and went to Denmark/Germany to find and bring back a second wife. To explore the basis of this story, I followed the time line of events and his travel back to Nebraska with Ida Lucia Martensen. - Carsten’s first wife, Margaretha (Hollman) Petersen, died 24 Apr 1886 nine days after a difficult birth of her seventh child on 15 Apr 1886. The child, a boy named Johan Henry Petersen, died a month later on 21 May 1886. - On 31 Jan 1887, Carsten’s father, Carsten Petersen, died in Joldelund, Schleswig-Holstein, Germany (formerly a part of Denmark). - Carsten traveled to Germany – When he began his travels is not known (Possibly there are newspaper articles or other records not yet found that show when Carsten left Nebraska for Germany and how he traveled.) - Carsten Petersen, Sr. and Ida Lucia Martensen sailed on the steamship Australia (see Ship/Line Notes below) from Hamburg, Germany on 4 Mar 1887 and arrived in New York, New York, USA on 22 Mar 1887 (18 days at sea). - Carsten and Ida arrived in Platte County, Nebraska less than a week later. - Carsten and Ida were married on 30 Mar 1887 in Columbus, Nebraska. The following are records of Carsten Petersen, Sr.’s return trip with Ida Lucia Martensen: Record of their departure from Hamburg, Germany \| Name: \| Ida Martensen \| \|\|\|\| \| Departure Date: \| 4 Mrz 1887 (4 Mar 1887) \| \|\|\|\| \| Estimated Birth Year: \| abt 1859 \| \|\|\|\| \| Age: \| 28 \| \|\|\|\| \| Gender: \| weiblich (Female) \| \|\|\|\| \| Marital Status: \| ledig (Single) \| \|\|\|\| \| Residence: \| Jordlund, Schleswig (Schleswig-Holstein) \| \|\|\|\| \| Ship Name: \| Australia \| \|\|\|\| \| Captain: \| Franck \| \|\|\|\| \| Shipping Line: \| Edward Carr \| \|\|\|\| \| Shipping Clerk: \| Hamburg-Amerikanische Packetfahrt-Actien-Gesellschaft \| \|\|\|\| \| Ship Type: \| Dampfschiff (Steamship) \| \|\|\|\| \| Accommodation: \| Zwischendeck (which is “steerage”, or between-deck, often shortened to “tween-deck”) \| \|\|\|\| \| Ship Flag: \| Deutschland \| \|\|\|\| \| Port of Departure: \| Hamburg \| \|\|\|\| \| Port of Arrival: \| New York \| \|\|\|\| \| Household Members: \| \| \|\|\|\| \| Source Citation: \| Staatsarchiv Hamburg; Hamburg, Deutschland; Hamburger Passagierlisten; Volume: 373-7 I, VIII A 1 Band 058 A; Page: 111; Microfilm No.: K_1735. \| \| Name: \| Karsten Petersen \| \|\|\|\| \| Departure Date: \| 4 Mrz 1887 (4 Mar 1887) \| \|\|\|\| \| Estimated Birth Year: \| abt 1850 \| \|\|\|\| \| Age: \| 37 \| \|\|\|\| \| Gender: \| männlich (Male) \| \|\|\|\| \| Residence: \| Omaha, USA \| \|\|\|\| \| Occupation: \| Landmann(Farmer) \| \|\|\|\| \| Ship Name: \| Australia \| \|\|\|\| \| Captain: \| Franck \| \|\|\|\| \| Shipping Line: \| Edward Carr \| \|\|\|\| \| Shipping Clerk: \| Hamburg-Amerikanische Packetfahrt-Actien-Gesellschaft \| \|\|\|\| \| Ship Type: \| Dampfschiff (Steamship) \| \|\|\|\| \| Accommodation: \| Zwischendeck (which is “steerage”, or between-deck, often shortened to “tween-deck”) \| \|\|\|\| \| Ship Flag: \| Deutschland \| \|\|\|\| \| Port of Departure: \| Hamburg \| \|\|\|\| \| Port of Arrival: \| New York \| \|\|\|\| \| Household Members: \| \| \|\|\|\| \| Source Citation: \| Staatsarchiv Hamburg; Hamburg, Deutschland; Hamburger Passagierlisten; Volume: 373-7 I, VIII A 1 Band 058 A; Page: 111; Microfilm No.: K_1735. \| Record of their arrival in New York, New York \| Name: \| Karston Petersen \| \| Arrival Date: \| 22 Mar 1887 \| \| Birth Date: \| abt 1850 \| \| Age: \| 37[1] \| \| Gender: \| Male \| \| Ethnicity/ Nationality: \| Russian[2] \| \| Place of Origin: \| Russia[2] \| \| Port of Departure: \| Hamburg, Germany \| \| Destination: \| Miperto[3] \| \| Port of Arrival: \| New York, New York \| \| Ship Name: \| Australia \| \| Source Citation: \| Year: 1887; Arrival: New York, New York; Microfilm Serial: M237; Microfilm Roll: 504; Line: 36; List Number: 303. \| - On the manifest, Carsten’s age is listed as being 34 years old – a transcription mistake. - The manifest clearly states that Carsten’s place of origin is USA not Russia – passengers on the list ahead of him are listed as being from Russia – a transcription mistake. - Carsten’s destination “Miperto” is not defined. - Carsten has been assigned quarters in the lower decks of the ship. - Carsten’s occupation is farmer. - Carsten was shipping a significant amount of baggage. \| Name: \| Sila Martensen[1] \| \| Arrival Date: \| 22 Mar 1887 \| \| Birth Date: \| abt 1859 \| \| Age: \| 28 \| \| Gender: \| Female \| \| Ethnicity/ Nationality: \| Prussian (German) \| \| Place of Origin: \| Prussia \| \| Port of Departure: \| Hamburg, Germany \| \| Destination: \| New York \| \| Port of Arrival: \| New York, New York \| \| Ship Name: \| Australia \| \| Source Citation: \| Year: 1887; Arrival: New York, New York; Microfilm Serial: M237; Microfilm Roll: 504; Line: 6; List Number: 303. \| - On the ship manifest, Ida’s first name is Ida and not Sila – a transcription error. - Ida’s occupation or calling is listed as servant. - Note that the location Ida’s apartment is on the Topp (German for Masthead) Deck I – a desirable location. Arrival in Nebraska Carsten and Ida traveled from New York, New York to Platte County, Nebraska in less than a week. Carson Peterson returned home from Germany last week, accompanied by his better half, whom he is introducing to his many friends. SOURCE: The Columbus Journal., March 30, 1887, page 2 Marriage Carsten and Ida were married on March 30, 1887 in Columbus, Nebraska. Mr. Carson Peterson and Miss Eda Mertin were joined in matrimony at the M.E. church at 3 o’clock p. m. last Wednesday. After the ceremony the bridal party and friends served refreshments at the residence of J. H. Johannes. We all wish them much joy and a happy and prosperous life. Citizen. SOURCE: The Columbus Journal, April 06, 1887, page 3 I am somewhat surprised that the bride would not have wanted to be married in the presence of her family. Possibly Ida already had family in Nebraska – several of Ida’s brothers and cousins did immigrate to Nebraska: - Mathilda Louise “Tillie” (Hansen) Petersen, a first cousin of Ida, immigrated to Nebraska in 1888. - Claus Heinrich “Henry” Martensen, brother of Ida, immigrated to Nebraska in 1891 (1900 US Census), 1881 (1910 US Census), 1893 (1920 US Census), 1881 (1930 US Census). - Christian Lorenz “Christ” Martensen, brother of Ida, immigrated to Nebraska in 1892 (1900 US Census), 1893 (1910 US Census), 1892 (1920 US Census). Other than possibly her brother, Claus Heinrich “Henry” Martensen, there appear to have been no immediate family members already in Nebraska at the time that Ida immigrated. (As may be noted above, the census record is mixed and leaves doubt that Ida’s brother Claus immigrated before she did.) So why did Ida and Carsten not get married in Germany? Possibly Ida was being brought over as a housekeeper and to care for Carsten’s children (Note that ship manifest on the arrival to New York has her occupation listed as servant – or maybe that was what she was in Germany) but on the way, Ida and Carsten fell in love? Or, was Ida possibly reserving her decision until she met Carsten’s children and she could see first hand what the situation really was before committing to marriage? Motivating factors to consider It is likely that Carsten would have been considering finding a new wife or at least obtaining help in raising his five young children ranging in age from two years old (my Grandma Brunken) to twelve years old.Ida was 28 years old at the time she made the trip to the USA from Germany. Several questions still remain How did Carsten and Ida meet? I suspect that a relative acted as matchmaker for Ida either being Carsten’s housekeeper or wife. Possible indirect evidence of this is that a year after Carsten brings Ida to Nebraska, Carsten’s niece (Esther Petersen) accompanies Mathilda Louise Hansen from Germany to Nebraska. Mathilda married Andreas “Andrew” Petersen, Carsten’s brother who is living in Nebraska. (Was this an arranged marriage?) Family connections are even closer as the mothers of Ida and Mathilda (Christina Maria (Thönsen) Martensen and Johanna (Thoensen) Hansen) were sisters and thus Ida and Mathilda were first cousins. Did Carsten go to Germany after his father’s death 31 Jan 1887 to pay his respects and possibly handle estate matters and then just happen to meet/find a prospective second wife? Or did he travel to Germany for the primary purpose of finding a new wife? We will probably never know the answer. What is known, is that Carsten did not immediately leave his children after his first wife died and go looking for a new wife as the family lore might imply. When he actually traveled to Germany is not known but it was almost a year before he remarried. Ship/Line Notes - Carr Line – “Established in Hamburg in 1879-80 as a tramp ship company, they expanded into the emigrant business in 1881 with a fleet of cargo liners. Speed was not a consideration and most westbound passages to New York took 17-19 days.” This compared to sailing ships which took around 40 days. http://www.theshipslist.com/ships/lines/carr.shtml Downloaded: October 10, 2014. - Hamburg America Line – “By offering cheaper fares, Carr Line entered into cut throat competition with other Atlantic passenger companies and in 1886 amalgamated with Robert Sloman’s Union Line under the title Carr-Union Line. In 1888 the Hamburg America Line purchased four Carr Line ships (including the Australia), together with their half interest in the Union Line.” http://www.theshipslist.com/ships/lines/carr.shtml Downloaded: October 10, 2014. - Australia – Ship Picture and Source Information: Ancestry.com. Passenger Ships and Images [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2007. Original data: Various maritime reference sources. Downloaded October 10, 2014. - Australia – Ship Description: Built by C. Mitchell & Co., Newcastle, England. Tonnage: 2,119. Dimensions: 297′ x 37′. Single-screw, 10 knots. Compound engines. Iron hull. - Australia – Ship History: Put into service in 1881 by the Carr Line. Acquired by Hamburg America Line from Carr Line in 1888. Wrecked near Antwerp in 1902. - Australia – Ship Picture Date: The Carr Line funnel was black with a broad white band. The Hamburg-American Line funnel was black on all ships (1854-1889) then buff on passenger ships (1889-1927). Hence the picture was taken 1888-1889.	2,317	common-pile/pressbooks_filtered	https://pressbooks.pub/oklahomabrunkencousins/chapter/ida-lucia-martensen-immigration/	pressbooks	pressbooks-0000.json.gz:51855	https://pressbooks.pub/oklahomabrunkencousins/chapter/ida-lucia-martensen-immigration/
mlJmtZLEnK_wxw1F	How to make pictures: easy lessons for the amateur photographer. By Henry Clay Price.	INTRODUCTORY CHAPTER. “ Seems ? — nay, is.” This was the compliment given to stereoscopic pictures when they were first made, so realistic did they seem. From the dim outline, the faint image discovered by Daguerre, photography has risen to be an art. Instead of unreal likenesses, portraits can now be made which speah through the perfectly reproduced expression of the face, and the sentiment indicated by the pose. Marvelously, too, are the beauties and glories of nature mirrored. The latest and most rapid advance in the art is due to the discovery of the sensitiveness of a gelatine film. This knowledge has been practically applied in the introduction of plates prepared with such a coating. These are called “ dry plates,” to distinguish them from plates which must pass through the silver bath and be used while wet. Gelatine plates are now in general use for taking pictures of out-door scenes, such as landscapes, houses, groups of people, and all animated subjects. INTRODUCTION. ever these plates are used. Vessels under full sail, horses speeding around a race course, and even trains under full headway, have been depicted by the gelatine film, as though all motion were instantly suspended. To the amateur the dark tent with its hidden mysterious manipulations was forbidding. It is no longer necessary for him to be encumbered with it. The poisonous chemicals of the old process, wdiich soiled the dress and stained the fingers, were odious. These and the dusty burdensome camera can be put with the relics of the deacon’s one hoss shay.” An equipment consisting of a tripod, lens and camera, dry platens and holders, are all that need now be carried by the view taker, weighing so little as not to be counted burdensome to any one. Naturally amateur photography has been given a wonderful impetus by these improvements, which make it a pleasant accomplishment ; and its scope and mission are well worthy of consideration. As a recreation, compare practice with a camera and the search for good picture subjects, to archery, rowing, lawn tennis, and other sports. Is it not as pleasant, profitable, and cultivating ? To saunter through green fields or by the river side with the eye alert for picturesque panoramas, to select what is worthy to be produced and treasured, ever comparing, criticising, and admiring, will be found to be no mean diversion, and will educate any one to look with keener eye and greater zest for the beautiful in nature. The exercise I commend is exhilarating, and there will not be the danger from over-exertion to be found in some sports. Besides the giving of health, there are studies made, perhaps uncon sciousl)?-, adventures sure to be met with, and the results of the sport to bring home. Our country presents scenes of as great beauty as any other, with the diversity that all can offer. Torrid, temperate, or frigid, plains, hills, and mountains — all are ours. There is scope enough for the amateur. As an aid to the work of the artist the camera has already been promoted by some who have won national fame as landscape painters. Do they disdain the methods of the old masters” in their art ? ^ot by any means. This is a time for progression, and art will not sulk and frown upon an innovation that helps out in its tasks, and gives a standard to judge the correctness of outline, perspective, and shading. The camera, in adding to the number of pictures an artist can produce, will not detract from the merit of the productions. The artist’s model poses for him as a pattern of loveliness to be glorified in his ideal. The lines of beauty are not a lesson of a day: many times must the study be repeated. Bare is the memory that can disdain all helps, and therefore I commend to the artist a portfolio, containing not alone crude sketches with colors faultily limned, but also with photographic productions, such as landscapes, groups of animated objects, marine views, as the fancy inclines. Combining relaxation with the gathering of tliese finished suggestions, work for a wliole season in the studio could in a short time be obtained. At the time of writing an artist is journeying and gleaning views along the Amazon. He took with his easel a portable photographic outfit, and when he returns it will be with a satchel packed with reminders of tropical luxuriance of verdure to be transferred to canvas. If the novice and the baffled student of art find it hard to delineate nature, or to make their fancies real, let them be wise and compare their pictures with those made by the servitor camera. By its use copies of the rare paintings of the old world can be made and brought home to be companions of the studio. The teaching of object drawing could well be supplemented by days in the field with this docile instrument, and as the result botanical specimens would receive better representation on paper, and more appreciation. There are many who are connoisseurs of art : artists they would be, but cannot, not even the pencil will do their bidding. Commend to them the camera, which will produce what they desire. Poor is the traveler in foreign lands who does not return with mementoes for himself and those he loves, in part to prove what he saw, and also to keep the scenes alive in memory. What more fitting, and what can tell the story like a collection of views ? the ladies. This improvement is noticeable in the dwellings of nearly all, whether of high or low degree. How that a photographic outfit can he so easily carried about, and pictures so readily made by the gentler sex, this means of aiding decorative work will be sure to be used by them. Cheap prints and crude crayon work must he put away in garrets and he superseded by photographed views, scenes of the old hillside homestead, pictures made in distant countries, or reminders of the summer liolidays. Set in tasteful frames adorning the walls, or bound between covers, the claim to ownership would he a double one, that of creation and possession. Oil paintings of rare merit would not be supplanted. There is room for both. Does a student want for satisfying pleasure ? Let him try the camera. It will aid him in the practical researches of botany, entomology, mineralogy, and what not ? — and also prepare him by the stimulation of exercise for the better study of each. By representations of the specimens captured, he can compare results with his instructors, or men more learned than himself. A scholar’s time will not be thrown away, if he in tliis manner courts only health. The explorer overcomes obstacles of travel to give the result of his discoveries to others ; but how can he make it real to them in a story or lecture ? It is a he has seen. These may be bound in liis books. How much better Bayard Taylor’s works would be could he have illustrated them ! Or the same pictures can be transferred to magic lantern slides and thrown on to a white screen, holding the keen attention of an audience. A missionary in the center of China is now supplementing his report to the home secretary by scenes reproduced from his daily experience among the pagans, showing their wretched condition serving heathen deities, and the awakened desire for a refinement of living as the result of the gospel’s mission. Pages of description will not tell as much as a few of such pictures. To tlie exile for Christianity’s sake, the use of an amateur viewing outfit will be a welcome addition to the privileges he enjoys. The farmer can find use for the camera to display the progress of cultivation in his fields. It will not bo an expensive luxury, and why should his life be all work and no play ? I think he will find greater satisfaction if he can look up from his toil long enough to analyze that which surrounds him, and rewards his efforts. Utility is in the spirit of the times, and our friend, the camera, would join with it. The practical part it is destined to play is now beginning to be foreseen. and good illustrations will be the result for the future, beside which some of the old productions of imagination will hide in shame. Correspondents for papers, or in mercantile business, may, at times, tind a pocket camera almost invaluable to give a finish to descriptions. Government surveys and all topographical records are now more complete because our modest friend has noiselessly performed its part. The wares of the merchant or manufacturer can henceforth be better and more cheaply illustrated in catalogues and price lists. In order not to be outdone, the example of some of the leading representatives of these branches of industry must be followed. This is not chimerical ! The camera is now assigned to regular duty, midst the din of toil — this silent worker ! To show a house, a bit of real estate, cattle, horses, or a pile of logs; a piece of mechanism or macliinery ; any new design of furniture, hangings, carpets, or ten thousand other objects, by a picture representation, when other methods would be quite expensive or unavailable, is a happy subterfuge. Architects with a neatly arranged collection of exteriors and interiors are the more inspired. Their patrons would be aided in selection by a more extensive number than they usually have, especially by pictures showing more of detail in the separate parts that make up dwellings. In the drawing up of their speciiications, or, in fact, in those drawn up by any craft or profession, ample illustrations would make biao:e. It is a wise rule adopted by insurance companies, to ascertain not only the nature of the goods on which the risk is to be assumed, but also that of the surroundings. One man hired to make such surveys of property, quick to see and apply an idea, adopted a pocket camera to verify his conclusions concerning the desirability of the risks offered. The appointed agent sent out to appraise property for a savings bank and loan association followed his example. With the trust deeds and abstracts of title are filed away his representations of real, not speculative and visionary securities. That recreation is more needed in this country is not denied ; nay, it is preached for, and the pen is vigorously used to agitate the subject. The nation will outgrow the hurry of youth. What shall be taken up as a respite from toil ? In the rationale of pleasure the camera is destined to play a sensible part, as well as an aesthetic. These many suggestions of its service -are given to lead the current of thought to its varied capacities, some of which may not have yet been dreamed of. Pictures were the symbols earliest used to express thought unuttered, and they ever have been the language universal of the world. How to make them, what purpose they can serve, and what pleasure they will afford, should be the theme of a pen most eloquent. DESCRIPTION OF APPARATUS. It has been tlie fortune of the writer to instruct many pupils in the lessons of amateur photography, and all of the success that has been attained I believe to be due to the use of simple but explicit language. In these chapters I shall try to leave nothing to be guessed at, nor any chance for doubt ; but beyond the line of actual experience and knowledge I shall not venture, hence the apparatus or other parts of an outfit here described or mentioned will be such as I am familiar with through use, and known to me to be reliable — perfectly so ! In selecting such articles — having learned by experience the importance, the necessity^ of a good equipment — I ask every amateur to purchase what is warranted by a house of known standing and veracity, and not to get what may be cheaper, but really worthless. HOW TO MAKE PICTUKES. In taking pictures tlie negative is first secured. This passes tlirough the various stages of development, and then the prints are made, which are mounted upon card-board to suit tlie taste. The first operation — that of producing tlie negative — is all that need be done at once. ing illustration shows all that is needed to be carried about, and the comfort and ease wfith which it is done. wayside orchards. By way of contrast with the carelesss, easy attitude of the figure just shown, I present one of the old veterans who toiled along. lieavily laden, to practice Iiis beloved art. If seen now with his old time luggage, it would be averred that he had been detained by a twenty years’ sleep with Hendrick Hudson’s crew. A good Apparatus Outfit, —Less than a year ago it was announced that a good outfit, every article of it warranted, consisting of a camera, with accompanying double dry plate holder, for making pictures 4x5 inches, a single achromatic lens, a carrying case in which to stow away and transport the camera, plate holders, and lens, and a tripod, would henceforth be sold for $10.00. The price astonished every one, photographers especially, although the outfits of this kind were designed particularly for the use of amateurs. Worthless toys have been offered for a trifle, which will not take a picture ; but all these lenses are guaranteed. Since the introduction of the cheap outfits, I have seen in the busy city of Waterbuiy pile upon pile of lens tubes bearing the name “ Waterbury ” as a brand, every one of them nickel-plated, and perfect in finish. When brought into use and tested by experts these lenses have proved to be possessed of something more than beauty. Hot one of the Waterbury lenses has ever been sent back to the maker as falling short of what it is guaranteed to do, and therefore I give this part of the outfit particular mention. Naturally, when one has discovered the object or chosen the scene that he is desirous of photographing, the carrying case is set down, and then follows the undoingand setting np of the tripod on which the camera is to be placed and fastened. Figure 1 represents the top and one of the three legs of a common tripod. First, the part D of each is iindoiibled as far as the brass band C will allow, and the button on the leg is turned, which makes it straight and rigid. The two upper of the three sticks forming a leg have holes on the inner side which slide on to the pins in the ears E E^ belonging to the tripod top ; and by pushing the loose end of the brace B into the slot in the opposite stick, the two pieces are sprung and held apart. Fern ember to have the brass piece G on the leg face out. In like manner put up the other two legs, and catch them on to the top. When set up the tripod will appear as shown in figure 2. Figure 3 shows a camera and lens. When not in use tl)e tripod screw is kept, as pictured here, screw^ed into the bed. Take it off, set the camera on the tripod top, pass the screw up through the hole in the tripod top, and screw it into the brass plate on the under side of the camera. A few turns of the screw will bind the camera fast to the tripod. Kelease the hook holding the ground glass frame, and if the lens is in the body of the camera, take it out, or out of the carrying case, if stowed there, and screw mahogany. In eyery respect these cameras are neat, good, and serAuceable. So it is Avith the rest of the outflt* The jury at the American Institute haye examined them in connection with the more showy apparatus, . and the award of excellence coA'ers both grades. Extract from the judge’s report at the Institute, concerning the apparatus just described: Fothing tention given to outfits for amateurs, their benefit to tlie young, especially in the direction of encouraging art studies, and a better appreciation of nature’s beauties. For this, as well as the whole exhibit, we recommend that a medal of superiority be awarded,” etc., etc. Many an amateur makes a beginning with one of the cheap outfits, and, having achieved success, chooses something finer and higher priced. Some there are who have but little time for recreation, and they will not care to expend more than a small sum ; but amateur photography is a luring art, and the desire is easily awakened for the gems of the camera makers’ skill. A feeling of pride concerning the equipment used, and emulation similar to that which has led to the construction of superbly finished yachts is sure to be aroused among the patrons of culture, leisure, or wealth. Such tastes and fancies may be gratified. Description of the finest Apparatus, — The wise maxim, always get the best, certainly applies to cameras. At the outset they cost more, but less in the end, because the best satisfies. Spanish mahogany, finished in French polish, is used in their construction. This wood is chosen as it wears well, and chiefly because it will resist the effects of moisture longer than any other. A camera that has not the property of resistance to dampness, cannot be depended upon while passing from one climate to another. The camera made of common wood in a moist region swells, and its movements become clogged and do not work well ; while in a dry, warm country the wood contracts, and seams open, through which light penetrates, working its baneful effect on a gelatine plate. The result is what is commonly called “ fogging,” a term which will be duly defined. I will suppose the amateur to have purchased a superb first quality outfit, and feel sure that he will not be disappointed in it. The camera forming part of it is provided with a front board that can be moved up or down, for the purpose of regulating the amount of sky and foreground taken in the picture. One of the two front boards buttoning on to the 5x8 size camera has a lens screwed to tlie flange on its face, which combination is used when a picture the full size of the ground glass is desired. This front may be shifted b}^ a lateral movement, and it comes in use when tlie box is clamped by its side to the tripod. The second front board lias on its flnished side two flanges, upon which are screwed a pair of matched lenses to be brought into use when stereoscopic pictures are to be taken ; a diaphragm or divider is set up so that two pictures of equal size will be made on a 5 x 8 gelatine plate. photographic parlance as a ‘‘swing back.” The set screw is turned down upon the brass guide on top of the camera to regulate the incline of the back. Still another feature worthy of notice is, that the ground glass frame is hinged at the bottom, so that, instead of taking it ofl when the plate holder is in use, the catch at the top is drawn aside and the frame is swung down on to the bed of the camera, as illustrated by figure 5. Hinges are also put on the bed, allowing it to be doubled over against the back of the camera when the hitter is to be packed. In focusing the brass guides on the bed, keep the back and front of the camera parallel to each other; when the back is drawn out far enough, a turn of the patent cam fastens it. Such cameras els with telescopic covers accompany the finest outfits. In them are carried, the camera, lens or lenses, dry plate holders, focusing cloth, focusing glass, and tripod top. Leather handles are attached to these carrying cases, but a shoulder strap can be fastened to them, and they may be carried at the side of the amateur after the fashion set by English tourists. One of these canvas cases, containing a 4 x 5 camera and one double holder, is eight inches long, the same height, and five and one half inches broad. The weight of all is but three and one half pounds. A 5 x 8 camera, double holder, and canvas case, together weigh five and three quarter pounds, and the case measures eight and one half inches long, eight and three quarter inches high, and six inches broad. holes in the outer joints. Of course this is repeated with each leg. Then press together the two nearly parallel pieces and hold the brass top (which is usually packed inside of the carryingcase) fiat side up, so that two of its pins will enter the holes or sockets on the outer side of the joints; release the pressure, and you will find the leg fastened to the top. Thus also arrange the two remaining legs, and the tripod is ready for its burden, jprovided you have the flat surface of the brass top iippermost. Fasten the tripod and camera together by the thumb-screw, passing it through the hole in the tripod top up into the plate in bottom of the camera bed. used for securing instantaneous exposures. The drop adopted for the Rapid Group Lens consists of a thin strip of brass, about three times the diameter of the lens in length, and wide enough to prevent light passing through the tube. The piece of brass A has a square hole cut in its center, about equal to the -diameter of the largest aperture of the tube, leaving a plain surface both above and below the hole, the lower portion shutting otf the light before exposing, and the upper after exposure. placed, by which the drop is held in position (the bottom of drop resting on the same) the lower portion of the drop stopping off the light ; the part with the square hole, • and the upper blank portion, projecting above the tube. When this button is thrown to one side, the drop is released, and it will naturally fall by gravi- tation, and an exposure occurs equal to the time it would take the length of the hole in the drop to pass the opening in the lens. The upper portion of the drop falling shuts olf the light. If the exposure is required to be still more rapid, a rubber band placed around the tube and stretched up and over the knob E on top of the drop, will accelerate its action. If you wish to copy a painting, engraving, or lettering, this lens will meet the requirements. For landscape and stereo-work, I recommend the use of the American make of Wide-Angle view Lenses, shown by figure 9. These favorite Lenses are perfectly achromatic^ and abso- ings of which are adapted to the focal length of their respective lenses. Where only a limited field is required, the full aperture may be used, while with the smaller stops, perfect definition is obtained to the margin of the plate. In selecting lenses of this description, the shorter focused lenses are especially adapted for street and other views in confined situations. will be found most useful for the amateur. To aid amateurs in the selection of these view lenses, I append the following table showing the height of image produced on the focusing glass, with a few sizes, by an object twenty-five feet high, at a distance of fifty feet. FILLING THE PLATE HOLDERS. Before starting out to take pictures, the plate holders must be filled with gelatine plates. Some of them hold two, and hence, if but two views are to be taken before the return, it will be best to fill but a single holder. If the amateur thinks to secure more than two picture impressions, he must govern himself accordingly in putting sensitive plates into the holders. As it is essential that this operation of filling, the holders should be done in a room or closet where all other than ruby light is excluded ; bear this fact in mind before leaving your base of supplies. It frequently occurs that an amateur is gone from home for a considerable length of time, and has, while away, no chance of darkening a room sufficiently in which to develop the exposed plates, or to refill his holders. In this case he must provide himself before starting with a number of holders filled with gelatine plates. The exclusion of white light from the room in which the plates are either placed in the holder, or afterward developed, should be both emjphasized and italicised. After you have closed the door, and believe the room to be dark, do not rest satisfied ; stuff the chinks and crannies. Overhead, nnderneatli, everywhere, stop out wliite light. Look through the keyhole ! there may not be a reporter outside, but there is as great an inquisitor, who must be barred out, and it can be done effectually. Having .faithfully attended to the imperative duty of securing black darkness, welcome the light which will not injure the sensitive film on the plates. This* can be admitted from without by light shining through a pane of ruby glass, or ruby paper over white glass ; but the more common and preferable light is that which is diffused from one of the ruby lanterns designed especially for this purpose (see figure 10), and I will suppose you are provided with one.* brand or label on the cover of the box. Take the telescopic lid off the box, lift out the package inside, undo the other paper wrapper, and you have now come to the glass plates with * Another dry plate lantern has just been introduced, more expensive than the one here illustrated, but with far greater illuminating power. Without question, it is the best one made, for home or stationary purposes, but it is less portable than the other. 11, which is tlie proper way, and dust oft' its glossy sensitive surface very gently with a caniel’s-hair brush. This is done to guard against the possibility of any speck or particle of dust being on its surface, the presence of which would eventually both sides of the plate. If you cannot detect the surface having the coating of gelatine otherwise, hold the plate between yon and the ruby lantern, and you will then perceive which side has been coated. Be careful, and forget not to keep every thing but the camel’s-hair brush away from the surface of the gelatine plate. Figure 13 represents the end of a liolder, and the shaded portion depicts the sensitive plate, while the dark lines denote the position of tlie sensitive surface during the time it is going to the scene of action, when it is exposed to white light to receive the image, and while it returns trophy-laden to the place where the victory is to be commemorated. That is anticipating, just as the amaFiG. 13. teur will be wont to do. Take up another gelatine plate, or rather, handle it now like an expert, and place it in the remaining unfilled outside groove of the holder. Be sure to ]iave,the sensitive side face outward. Insert the slide C in the central groove of the holder, as indicated in figure 12, and push it clear in to the stopper. If the springs on this piece catch on the edges of the plates, bring a slight pressure to bear on them with the thumb and forefinger of the left hand, which will remove the trouble and permit the slide to be forced in to its hilt, or so called “ stopper.” See if the slides B B (thus denoted in figure 12) are pushed in also. The purpose of the slide C is to keep light from passing through from one plate to the other during the time the first plate is going through the operation commonly called taking the picture.” Fogging is thus again avoided. Back to back the plates are placed and each has its own time appointed for seeing the light and treasuring what is seen. Another mission of the slide C is to keep the plates in focus by means of the springs on its surface. When all of the slides are pushed in as far as they were designed to go, the holder should be absolutely light-tight. It should not only be so when it is sold, but it ought to remain so, and there’s the rub ” with a cheap holder. A good holder is a prime factor of an outfit of sterling worth. Better have none at all than a poor one. But to recur, the slide C should only be taken out in order to remove gelatine plates ready for development, or to place fresh ones in the holder, and the slides only drawn out during an exposure. There is a screw or pin you will observe on the upper side of the holder. By its side is stamped the figure (1) one. Invert the holder and in the same position behold the figure 2. Bemember about these figures when you have the plate holder in use. Give number two a chance to see the light. Number one will overdo and be spoiled if used twice. After filling the plate holder, or, if you so choose several of them, rewrap the remaining gelatine plates of the undone package, put them in the card-board box, replace the cover, and hide away the plates from their arch enemy, white light, so great a blessing elsewhere. It is time to come out of seclusion, so throw open the door and put out the lantern light. There are worlds you are sighing to conquer. Away ! be back to them, and study what each horizon bounds. Learn like the photographer in his study of physiognomy, that there is nothing duplicated under the sun. TAKING THE PICTURE. With the position chosen from which to take the picture — this, by the way, should be selected so that the sunlight will shine from the rear, or at one side of the camera, never in front — you set up the camera and tripod, and in doing this be sure that the top of the camera is level. the legs of the tripod to lower the camera. If you cannot wdth your eye determine about the true position of the camera, it would be well to carry wdth you a spirit level of vest pocket size. There are times when the camera may be pointed at a small angle upward or downward from the plane of the horizon as a variation from the rule just given, to offset which swing the ground glass to a vertical position. Let me emphasize the command not to have the camera incline either to one side or the other. If the upright sides of the ground glass frame lean to one side, so will the picture. The camera may be swung round by loosening the screw which binds it to the tripod. When swung far enough, turn the thumb screw until the camera is again fastened tightly to its support. From out of the carrying case or some other receptacle pull the focusing cloth, throw it over the top of the camera, and gather it tightly at its sides. Under the hood thus formed thrust your head. Do not cover the lens with the cloth. The object of the hood is to shut out light excepting that which enters through the lens and throws a reversed picture on the ground glass, which acts like a semi-transparent mirror. Uncap the lens and draw the back of the camera toward you. After a moment your eyes will become accustomed to the situation, and the picture will seem to have already been secured. It is not a permanent impression, but like that of the mirror. Continue to draw the back of the camera toward you, and the image will appear more distinctly on the ground glass. When you see the image most clearly you have obtained the right focus ; neither the word nor the operation is difficult ; a little practice will master both. While standing in the same position look all around the edges of the ground glass, and make sure that the picture is as clearly defined there as it should be. Photographers would speak of securing “ good definition.” Having made sure of this, fasten the back of the camera by a turn of the clamp screw. How lay aside the focusing cloth where it will be safe. Spring back the catch shown in figure 3, and put the ground glass and frame out of the way. Be careful not to break the former. Place the cap on the lens. Take a double dry plate holder, and turn it so that the heads of the dark slides face to the right (see fig. 14, showing holder in proper position). dark slide B be drawn out, one side of the sensitive plate would necessarily catch the light before the other, with a result not at all favorable. Or, on the other hand, a longer exposure than is desirable might be given. There is a proper time to doff the cap. It is after you have pulled out the dark slide B nearest the camera (which please lay on top of the camera), and also after you have decided how long the sensitive plate should receive light through the lens in order to get the best results on the film. trees, houses, and a pond — the atmosphere clear, and the sun brightly shining. The sky will be photographed on the him very quickly, the pond not quite as rapidly, the impression of the bright colored houses will follow next, and lastly the dark green foliage. You have in use an achromatic lens of six inch back focus, and a stop of a quarter inch o]:)ening. (Do not be alarmed at these words, for you will or may ascertain such points about a lens when you purchase one.) The gelatine plates in use we will suppose to be what are called rapid, hence you decide upon hfteen seconds’ exposure, as denoted by your watch. Uncap the lens by a quick movement, but do not jar the camera, and as soon as the allotted time has passed recap the lens, replace the watch in your pocket, and push in the dark slide. Y ery soon an amateur can learn to mark off seconds without having to verify the count by a time-keeper. A little practice of counting off the flight of seconds, when one has nothing else to do, wdll learn the* lesson. Take out your pencil and note book, and make the following or the befitting record of observations : years of experience in photography. They make frequent reference to the notes, and from them deduce calculations of the length of exposure to be given under similar circumstances. Then again the notes enable them to compare observations with others. So, amateur friend, do not forget your note book, at least you will be driven to it to find out the numbers of the plates that have been exposed, and to thus avoid using them again. The plate holder can now be put in the carrying case, and indeed the whole outfit be folded into its most compact form, or the tripod and camera may be carried shoulder arms ” if the amateur expects to pitch the tripod, and give battle to another surrendering scene not far distant. Ah ! by way of diversity, here is a fine marine view with the blue sky, the broad expanse of the sea, boats at anchor, and a small dock to give the picture a finish. This is a treat ! When you have secured the right focus, and start to substitute the plate holder in place of the ground glass, recall the fact that plate number one has on it a picture impression, and must not be used again, so the holder should be • inverted, and figure 2 be on the uppermost side. Also remember about the dark slides facing to the right. Before uncapping the lens again, calculate how long the cap should be ofi. The sky casting down direct, and the water giving back reflected light, action on the sensitive film will be more rapid than in the former view, and you therefore decide upon ten seconds’ exposure. Draw out the dark slide nearest the camera. Have you got hold of the right one? ’ Tis well! lay it on the camera. Uncap the lens, count (lo) sec- onds, and recap. Replace the dark slide, and return the holder, with its two hidden trophies, to the carrying case. Have your note book tell the story of the capture, and where it took place. By this time perchance you are hungry enough to “ eat a bear ; ” you did not think that a luncheon would be needed, so little appetite did you have before starting, but now you are certain that you will go home and see that dinner is served promptly this day at least. DEVELOPMENT OF THE PLATE. It is not essential that the operation next in order with the gelatine plate shall follow at once, or the same day, or week. The amateur can suit his convenience in the matter. Dry plates have been exposed in the arctic regions, and developed in England. They have been used in Africa, and brought home over six thousand miles after months of travel to be developed. For the above manipulation the following list of accessories are requisite : Two vulcanite trays, one fourth ounce glass graduate, a set of five inch Japanese scales and weights ; and of chemicals, say one ounce bromide potassium, one ounce sulphuric acid c. p., one pound neutral oxalate potash, one pound protosulphate of iron, one pound hyposulphite cf soda, and one pound alum. These accessories will probably fie kept where the dry plates also are stored. Into this closet or room are taken the dry plate holders containing the exposed plates, the door of the room is shut, and again all white light is barred, thrust, and stuffed out. The seance can now go on by ruby light. from a holder, which latter please grasp with the left hand as shown in figure 15, and holding the right hand to within an inch of the opened end, tilt forward or raise the other end of the holder so that the gelatine plates will slide 11, and at the same time the holder is so inclined that the other plate will slide back into its former place. The holder can now be set aside. Lower the gelatine plate into a vulcanite tray, and Tcee^ the sensitive side upjpermost. Look to this ! Put the slide (7 back into the holder. From a pitcher or glass pour clean water into the tray until it is half filled. Leave the plate in this cold water bath, and mix your developer solution ^ as follows : With a graduated glass, in appearance like figure 16, measure out two ounces of oxalate of potash solution, which is made by the following formula: bromide of potassium. If tlie solution does not turn blue litmus paper red, then add a few drops of a saturated solution of oxalic acid until it does. This solution will keep indefinitely. Pour the solution from the graduated glass into a tumbler kept for this use. Pinse out the graduate, and pour into it one quarter ounce tions of the tumbler will mix the two. Set the tumbler down, and pour off the water in the tray, using care that the gelatine plate does not slide out, and also that its surface is not handled. When the water has been drained off, pour the developing solution from the tumbler into the tray. Should any air bubbles form a slight touch of the finger will displace them. Bring the ruby lantern close to the side of the pan (see ligure 17), so that you may better note the action of the developer upon the gelatine him. If the latter after a short time shows no sign of a change taking place, consider that you did not give the plate too long an exposure, and such being the case flow the developer hack into the tumbler, and to it add another quarter ounce of the iron solution. Shake the tumbler a few times, and pour the new solution into the tray. Watch the plate, but restrain impatience. Along its edge a dark streak appears, which indicates that the sky is developing. Soon the outlines of a building with windows, and general details appear, and lastly the foliage — such would be the order if the ])icture possessed these features. Allow the gelatine plate to remain in the developer until what is of a milky whiteness begins to turn gray in color, and the image seems to fade away, then pour the developer into the tumbler,riind flow clean water on to the plate. Replace it with fresh, raising the plate so that the water may wash the under as well as the upper side of it : again renew with fresh water, and prepare for the next process, which is termed fixing the plate. Pour into the unused tray enough to half till it of the hyposulphite of soda solution, the formula for preparing which is as follows : than a hyposulphite of soda solution. Remove the plate from the tray where it lies, handling it just as has been illustrated, and place it in the fixing solution contained in the second tray. Again be sure to have the sensitive or film side up. Keep the plate in this solution until all the milky whiteness has disappeared from the back of the plate : this will be noted by raising the plate with the finger, and examining the lower side. If any white patches remain, replace the plate in the solution. Patches must thus artistically be hidden from view, so allow a little additional time before taking out the plate, to be sure that they have all disappeared. Then take the plate out of the solution, and wash it thoroughly. White light will not now darkened room. Every particle of hyposulphite of soda should be removed from the film and plate. The washing is done by permitting a gentle stream of water to flow over each side of the plate. Do not permit the fingers to touch the film, as thus the negative would be marred. After carefully and completely cleansing the plate, rinse out the developing tray and pour it half full of the alum solution, wdiich is mixed according to the formula presented here : Place the plate, film side up, into the new bath, and permit it to remain there five minutes, while 3^011 cleanse \mur hands from an}^ adhering soda solution. Remove the plate from the tra}^, wash it for a few seconds, and set it up to dry, which may require a number of hours. Do not use heat to dry the plate, as you would thus melt the film, and so cause the gelatine to run about or off the plate. Then your picture would resemble ‘‘castles in Spain,” nothing more defined, everything depending on the power of imagination. I present in the following illustration, figure 18 (page 46), a very convenient receptacle for holding gelatine plates when drying, which is called a negative rack. Set the plate in this, or where it will not be disturbed while drying. Plate number two can now be put through the course of development and fixing, and into the negative rack. Before doing this, however, that is, handling plate number two, empty the rinse out also. If the ruby lantern light has been extinguished, relight it. Once more, banish all white light from the closet. Briefiy permit me to enumerate what plate number two is to pass through. 1st, take the plate out of the holder. 2d, place it in the developing pan, and pour water on it. 3d, pour off the water, and replace it with the mixed developing solution. 4th, wash and fix the plate. 5th, wash and place the plate in the solution of alum. 6th, again wash the plate, and set it in the negative rack to dry. The presumption in this summary is that the gelatine plate was given the proper length of exposure. exposure lias been given. To correct the effects of this it will be necessary to reduce the developer with water; say one ounce of water to two ounces of the oxalate solution, add to this dilution an eighth of an ounce (that is one dram) of the iron solution, and two or three drops of a sixty grain solution of bromide of potassium, which is made by dissolving sixty grains of bromide potassium in one ounce of water. sure, the solution is drawn upw^ard into the tube. On removing the tube and pressing the cap, as shown at (7, one or more drops may be expelled according to requirement. A Stock Developing Dottle. — While pursuing the subject of development it will not be amiss to call the attention of the amateur to a very convenient receptacle illustrated by figure 20 (page 48). This is a bottle, B, with an outlet near the bottom, which opens into the end of a rubber tube having the other extremity guarded by a clip. Into this bottle pour twenty-four ounces (one and a half pints) of oxalate of potash solution. Pour on enough paraffine oil A to cover the oxalate to tlie depth of half an inch. Measure out three ounces of the protosulpbate of iron solution ficiently, remove the plate, w^ash it, and place it in the fixing solution. While the plate rests there a funnel C with a filter inside is placed with its small end in the neck of the stock bottle. impurities. After this, remove the funnel and cork the bottle. With the stock bottle you may have a developing solution ready for use at any time, and the developer can be used over and over again. The oil is pou)’ed on the surface of the solution to keep air away from it, and prevent precipitation. If after awhile the developer does not seem to act with energy, add a quarter of an ounce of the iron solution. If many plates have been developed with this solution, I should advise that to each ounce of the solution remaining two grains of bromide of potassium be added. Label this bottle “ Old Developer and in the same kind of a bottle mix a fresh developer as before compounded, viz., oxalate of potash, twentyfour ounces, with the oil on top, then three ounces of the iron solution. This is the one to be used next in developing your plates. Yon ask, perhaps, for a method to tone up a negative that is weak, but has good detail. The manipulation should proceed in this manner. After your regular developer has brought out the detail, showing alack in strength, pour the developer back into its bottle, then flood the plate with some of the old developer containing the extra bromide of potassium. In this way the negative will acquire strength. From this description, chemical manipulation may seem complicated, but the processes are not really so. Rather than have the amateur grope along trying to discover wliat will bring success, and wliat will lead to error, 1 have endeavored to mark out each step to be taken. Still, if the amateur hesitates and wavers, not trusting his own ability to manipulate a plate, he can have the development done by a professional photographer, and also the printing, toning, and mounting of the picture. I do not recommend this. To go it alone ” is the true American way. If doubts arise, consult with some one of experience, and believe in your ability to do what other amateurs have done. VARNISHING THE NEGATIVE. We left the negative in tlie rack drying, and it must be thoroughly done before tlie next process is attempted. My plan is to leave the negative in the rack over night to dry. It follows next in order that a coating of varnish (prepared and sold for this purpose) should be put over the film on the negative to preserve and protect it. So warm the plate slightly ; do not use much heat, only just sufficient to give the plate an indication of warmth. Grasp the plate by the corner with the left hand in the manner shown in figure 21. Have the film side up. With the right hand remove the cork from the bottle of varnish, and, taking it up, pour enough on the plate to make a pool, which can be spread over the surface of the plate, but not so much that the varnish will run off at the edge. Figure 21 illustrates the act of pouring out the varnish. Incline the plate so that the varnish will flow to the upper right hand corner, vary the inclination, and send the varnish to the upper left hand corner, then around to the corner held by the hand, and finally to the lower right hand corner. It will of course be surmised that the object of these movements is to coat the film on the plate over evenly with varnish. When the varnish has reached the lower right hand corner, the bottle should be placed as indicated by figure 22, so that it will catch the surplus varnish. Gradually the corner distant from the bottle is raised so that all the excess of varnish will run off the plate, to accelerate which give the plate a slight rocking motion to and fro from right to left. As soon as the varnish ceases to run off, remove the bottle, cork it, and draw the lower corner of the plate over a bit of paper to wipe off any drops clinging to the edge. Warm the plate to dry the varnish, using only sufficient heat to cause it to dry with glossy brilliancy. Set aside the varnished negative for a few hours to cool and harden, and then it will be ready for the printing frame. When a number of negatives have been developed and varnished, there are two methods of preserving them from the dust, and from scratches. One is by putting them in In other words producing a positive picture on paper from a negative. For this purpose are needed two porcelain trays, one printing frame, some ready sensitized paper, a bottle of chloride of gold, a quarter pound acetate of soda, one ounce chloride of lime, one pound hyposulphite of soda. This is a fair proportion of chemicals. Before commencing to print, determine how many pictures you want from each negative, and cut the proper amount of sensitized paper into pieces the size of the negative. There are in each sheet sixteen pieces, four by live inches in size. Use an ivory paper cutter, and do not allow your fingers to touch the sensitive, or glossy side of the paper. Put the pieces of sensitive paper in a large envelope, which please place in a shallow paper box and conceal in a dry and dark place until wanted for use. Sensitized paper should be handled onlj^ in a weak light. also dust off the negative. The outside of tlie frame may not be harmed by the same operation. Put tlie negative in the printing frame so tliat tlie film side is up, and upon it place a piece of sensitized paper with its glossy side down. Replace the back board in the printing frame. Note that the paper underneath is smooth. Fasten the springs by sliding the ends under the buttons on the frame, using gentle pressure to avoid breaking the glass negative under- PIG. 24. neath. The placing of the sensitized paper in the frame must be done in a subdued light. Carry the printing frame, when all closed up, to the window, lay it upon the sill, and let the light fall upon the front of the frame. Occasionally remove the frame from the window, stepping back into the room to examine the print. Loosen one of the springs, raise one half of the back to a perpendicular position, as shown in figure 24, bend back the sensitized paper and see how the printing is getting on. When the print looks darker than you wish the finished picture to appear, remove it from the frame and place it awa)^ from the light ; a drawer or box is a good receptacle. Put another piece of sensitized paper in the frame and continue as before, until you have secured the desired number of prints from this negative. The following cautions will not come amiss at this point. Never drop your negatives into the printing frame, but rather lower them in gently. Some negatives may require continuously the full benefit of the sun’s rays on the printing frame, but the greater number do better in a more subdued light. Never permit anything to throw a reflection on your frame while printing with it. Although toning is the next operation, you will naturally prepare the toning and fixing solutions before proceeding to make the prints. The formula for preparing the stock toning solution is as follows : Into 7^ ounces of water dissolve 15 grains chloride of gold and sodium.^ then add to it 300 grains acetate of soda ^ and 7 drops of a saturated solution of cJdoride of lime. You now have a solution, which should be made twenty-four hours before using: being a stock solution it will keep, and is alway ready when wanted. Pour clean water into one of the porcelain trays and into this bath place the prints. Toning should be done in a weak light. Do not get too near a window, but have sufficient light to see distinctly without requiring guesswork. After the prints have soaked awhile in the water, pour it off and renew with fresh. This should be repeated a number of times, and at the last change permit the prints to soak while you prepare the toning bath according to the following formula. Take of the stock toning solution one half ounce^ pour it into the unused porcelain tray^ add to it seven ounces of water and agitate the tray in order to mix them well. The water is now drained off the prints, and they are placed in the solution just mixed face downward, one at a time, pressing them down into it with the fingers. When you have finished this, commence leisurely to turn them over, and this reversal or turning over should continue while they remain in this solution, in order to secure even tones. The prints are presumed to be toned sufficiently when on examination by transmitted light, the whites are found to be clear, and by reflected light the pictures have a purple tint. Keniove the prints from the toning solution (which preserve for future use), and wash them well in clear water, using the now empty dish for the purpose. Prepare this solution the day before it is to be used, or warm to ninety degrees. Put the prints in the fixing solution to remain twenty minutes. (This should be used but for one lot of prints). After fixing the prints wash them thoroughly and well, and then hang them up to dry. As stated TONING THE PRINTS, AND FIXING THEM. 59 before it is necessary to have all trace of the hyposulphite of soda removed from the prints. This is accomplished by long washing in running water. In the photographic galleries this washing is continued all night, which would not in all cases be convenient for the amateur. Some five years ago Mr. H. J. ^Newton, a well known amateur, brought before the photographic community a simple and effectual means of removing the hyposulphite of soda from the prints with far less washing, to wit: First prepare a stock solution by dissolving two ounces of acetate of lead in sixteen ounces of water. After the prints are fixed, wash them in three or four changes of clear water, allowing them to remain in each change a short time. While in the last change measure out four quarts of water, to which add two ounces of the above lead solution. This addition wdll give the water a milky appearance; add acetic acid until the solution clears up, and place the prints in this solution, leaving them there from five to ten minutes. Then remove and vrash in several changes of clear water, and hang them up to dry. This ended, they are ready for mounting, which can be done to suit the taste. Blue Prints. — There is another method of producing a positive picture on paper, which is very simple ; it is called the process, and is adapted the printing frame, film side up, upon it lay a piece of ferro-prussiate paper, colored side down. After fastening in the back, carry the printing frame to the window, and turn the front side out to receive sunlight upon it, for from three to ten minutes. Occasionally take in the frame to examine the printing, and as soon as the image is distinctly seen on the paper, place the print in a pan of clean water for from fifteen to thirty minutes, or until the whites of the picture are clear, when you will have a permanent blue print on white paper. The handling of this paper should be done in a very weak light until after it is washed. Lamp or gaslight will not hurt it. TRIMMING AND MOUNTING PRINTS. Prints can be trimmed, one at a time, by laying a ruler over them, and cutting along the straight edge with a very sharp knife, but the more scientific method is to use glass forms, as the picture can be seen through them, cut all around the edges. Better than a knife for this purpose is one of the straight trimmers illustrated by figure 25, as it makes a clean cut edge, not a rough or uneven one. Mounting the Prints, — When through trimming the prints my plan is to dampen a light of glass, at the same time making sure that it is clean. Then I take each print separately, and immerse it in water until it lies flat. (By this time you realize that prints, as well as negatives, must accept the doctrine of total immersion.) Then place it face down upon the light of glass ; on top of it put another print facing down, and so continue until all of them have been dampened and thus piled up. Drain off the surplus water so that the prints will not be too wet. The paste used for mounting must be sweet. Sour paste will spoil your prints. Do not forget this fact, and }mu will not after a while have to lament about the fading and staining of some choice view. Parlor paste is the best for an amateur’s use, as it keeps well, and is always ready for service. It is only essential to see that the bottle or jar containing it is corked (when not in use) to keep out dust. With this paste keep a bristle brush — a two inch brush is best — as a large surface can be spread over with paste in a short time, and it will do the work evenly. After wetting the brush, and squeezing out the water, dip it in the paste, and apply this to the upper surface or back of the top print on the pile, passing the brush backward and forward until an even coating is put on. See that the edges are not neglected. With a knife blade lift one corner of this print, grasp it with the Anger and thumb of the left hand, and raise it off the other prints ; at the same time take hold of the lower edges and turn it in such a manner that the print Avill be suspended paste side down between the two hands. Now bring it over to the card-board or mount, and poise it over the middle. Gently lower the center of the print down to tlie mount, and carefully push one edge, and then the other down to tlie carboard surface. Place a clean piece of paper on the print, and, commencing at the center, rnb with the hand toward one end and then toward the otlier, to press out all air from underneath tlie print. If it appears to be smoothly pasted on, lay the mount aside. After jmii have finished mounting prints, wash off the glass, and cleanse the brush. Please set the mounts up separately to dry. Let me suggest at this point, before I forget it, a handy appliance for mounting, or, in other words, rolling down your prints after they have been pasted. It consists of a round turned stick, over Avhich a piece of rubber tubing has been drawn to cover the surface, and to fit tightly. Six inches would be a convenient length for tlie stick and tubing. Put a three quarter inch screw in the center of each end of the stick. Bend a piece of stout wire in a half circle, and then twist the two ends, so that the screws will go into the rings thus made as tar as their heads. Passing the screw up to the heads, through these two ends, and turning them into the ends of the stick, you will have a handy implement for rolling dowm the prints after they are laid on the mount. Should the occasion arise when you desire to mount a picture on very thin card-boaid or on paper, the following special material should be used if you would have the prints when dry, lay flat and be free from puckers. Take of ISTelson’s No. 1 gelatine four ounces : water, sixteen ounces. Allow the gelatine to soak in the water for ten minutes, then set the bottle containing it in hot water to make the gelatine dissolve, after which add one ounce of glycerine, and then five ounces of alcohol. With the paste thus made there will be no trouble about mounting prints according to the pre- pair of covers made with expanding backs, so that from six to twentyfour pictures may be inserted in one cover. Figure 26 represents the cover, with perforations in the back through which the spreading clasps ot the paper fastener bind the whole together. The pictures are mounted in the usual way, and strips of linen or strong paper of the proper width are pasted on one edge, through holes in which, as jnst intimated, paper fasteners are inserted. These can easily be put in, or taken out. The whole arrangement is simple and will be comprehended at a glance. For binding together views, a series or set of landscapes, or photographs of any kind, they are very serviceable. negative before drying. Do not use the fixing pan for any other purpose than to hold the hypo solution ; label the pan so that there will be no mistake. plate. After removal from the fixing solution, the negative must have the hyposulphite of soda thoroughly washed out of the film. This is important. Should you pour too much iron solution into the oxalate solution it will cause a yellow precipitate to form. Always add the iron to the oxalate, and do not reverse the order, or the same trouble will ensue. ITEMS TO BE BORNE IN MIND. Never fail to pour clear water over the plate before developing. If you follow' this direction, disagreeable markings, resulting from a stoppage in tlie flow of tlie developer, wdll be avoided, and at the same time air bubbles, wdiich cause transparent spots in the negative, will be prevented. By taking an extra ground glass wdien going far way from a base of supplies, should the one in use get broken, the second one w"ill be a w'elcome substitute. Under exposure gives strong and clear shadow"S, but the picture produced from the negative is w"anting in detail, and has a hard appearance. Dust off the surface of gelatine plates wdth a soft camel’s hair brush. The so-called pin holes in the negative are caused by dust. In this connection it will be w'ell to add, keep the camera, lens, and holder well dusted out, for no evil effect will result from it. Quite the reverse. PHOTOGRAPHY FOR LADIES. Although the art beautiful has some conspicuous and skillful devotees in an amateur way among the ladies, the time and appliances have not been ripe until now for popularizing this recreation among them. To have mastered a science or art, when the difficulties surrounding it have not been conquered by genius, is praiseworthy, and therefore much credit is due to the pioneer picture makers of the fair sex. The same results that they achieved, and better, can now be obtained by perfected appliances which I am about to describe. If amateur photography is pleasant with the environment shown in the illustration on the following page, can the gentler sex resist an accomplishment which henceforth may combine the maximum of grace and fascination? Here, as well as abroad, amateur photography is destined to be taken up by ladies of rehnement and quick artistic perception. The “ tyrant man ” will not be needed to carry about a pocket outfit, consisting of a 4 x 5 camera, accompanying dry plate holder, and an extension tripod, weighing complete but three and three quarters pounds. Figure ~No. 27 depicts a pocket camera when folded np. Such cameras are made in two sizes, viz., 4x5 and 5x8 inches. This recently patented pocket camera is provided with brass pieces hinged to the frame of the camera, and movable, so that they may be either folded down upon the side of the camera, or swung out to button on to the camera front, when it is drawn out and the bellows extended. No little pains and ingenuity w^ere expended to combine utility with compactness. The resulting apparatus looks so simple that one is tempted to exclaim, “any one could have contrived that.” Many have tried to make pocket cameras, but have succeeded only in name, not in reality. This 4x5 pocket camera when folded up compactly is but one and three quarters inches thick, wdiich is not more space than an ordinary book occupies. No case is needed to stow it in and take it about. The aforesaid being of the sterner sex will undoubtedly put such a camera away in one pocket, and the plate holders in another. It would be quite recherche for the ladies to use for this purpose a hand satchel or velvet bag. The latter especially might be made very handsome, and at the same time so as to be used for a focusing cloth. Another new pocket camera, for which application for a patent has been made, is provided with lazy tong levers^ which permit the front to be drawn out for focusing, to be swung up or down ; there is also considerable freedom of motion to one side or the other. Either style of camera is made of mahogany, tinished in the finest style. The bellows are of a purplish hue, wonderfully harmonizing with the mahogany and polished brass work of the camera. The fiange on the front board has a thread cut inside in such a manner as to permit the lens, when not in use, to be screwed on inside, and thus to be neatly sto’wed away in the camera. American lenses are the best to use in connection with pocket cameras. Accompanying the pocket cameras are single dry plate holders which will deserve mention. Figure 28 illustrates one of them. Upon the stopper to the slide a catch is set which hooks into an eye on the frame of the holder. At the pleasure of the initiated amateur the catch may be unset, and the slide drawn out. The movable back of this incomparable plate holder has rabbeted edges, which slide under grooves in the edge of the frame, and a spring at the top of the plate holder holds the back in place. Another spring on the under surface of the back keeps the plate in focus, and also serves to throw out the back after it has, by upward pressure of the hands on its outer surface, been moved far enough to allow the rabbeted edge to slide out from under the edge of the holder. This holder will serve alike for use in the studio, and for out-door work. The tripod, devised especially for use with pocket outfits, is not intended to be put in any pocket, unless it be those possessed by people of the stature of feet and nine inches. Glance at figure 29. The button on each leg may be turned at pleasure, thus shortening or lengthening them, and giving with celerity any incline needed for the cam- sess such cameras. Ladies and gentlemen alike or together might share in their use, and the pleasure they may afford. Some of the Amateur Photographic Societies now forming will do a graceful act by inviting ladies to This is called rilling P Should it show itself at any stage of the manipulation, immediately remove the recalcitrant plate and flow over its surface a saturated solution of alum, wash the plate, and proceed from the point where you left off. A strong solution of hyposulphite of soda often causes frilling, so do warm solutions, and treating the negative with a weak solution of acids. make weak prints. If the edge of the plates, which were protected by the grooves in the holder, remain clear, then fogging comes from lack of care in developing. clear but weak. Negatives which require a long time to fix show one of two things ; either the hyposulphite of soda solution is too strong or too weak. About one ounce of the soda to six ounces of water, is a safe rule to go by in making this solution. Negatives from which a number of prints are required must be varnished, or otherwise they will turn red from a combination of the free silver in the sensitized paper with the gelatine film of the negative. Exposed plates may be kept some weeks before developing, but the better plan is to do this as soon as possible after taking the view. Should a plate by accident be exposed to light, it may possibly be recovered for service in the following manner : In two ounces of water dissolve twenty grains bichromate of potash. Into this solution lay the light-struck plate for five minutes : of course this is done in the darTc room. At the expiration of the time, it is taken out of the solution and washed in several changes of fresh water, and set up to dry b}^ ruby light. When dry the plate is ready to be placed in a plate holder and exposed. If not to be used, pack the plate away where concealed from light. When a plate is exposed in the camera and you are certain that the result is not good, as for instance ' in taking a group of which one or more of the figures moved, put the plate through the mild course of treatment just prescribed, and it may be rejuvenated for use a second time with a more successful result. Mistakes in timing an exposure are man3^ The professional photographer may err. If the calculation cannot be made with certainty, have the error on the side of over rather than under-exposure, as the former can be controlled in the development. USEFUL INFORMATION. Too much density in a negative can be reduced by flowing over the fllm, after it has been washed with water, the following solution: Water six six ounces, chloride of iron one drachm-. If the reduction is to he only a slight one, make the proportion of water greater. After a brief period wash the negative and place it in the flxing solution once more, then wash it well to remove the hypo, and set the negative up to dry. Should only small portions of the negative require reducing, wash the plate, after which, with care, apply the reducer to the parts requiring it with a soft brush, and then wash the plate and put it in the flxing solution. Density in a negative may be increased in this way. After the detail is brought out with the oxalate developer you are using, pour it off and flow over the plate an old oxalate developer mentioned on page 49, containing three grains to the ounce of bromide of potassium. It after this treatment you still lack the density you desire, fix the plate in a solution made up as follows : Dissolve one ounce of proto-sulphate of iron in three ounces of water. In another bottle dissolve one ounce of hyposulphite of soda in three ounces of water. Mix the two solutions in a tray, permit them to stand a while, and then immerse the negative in the mingled solutions. After flxing, wash and dry the negative. Notebooks aftbrd a means of recording everything essential relating to the exposure of a plate in the camera. Do not fail to make use of them, as ad- monished in a previous cliapter. Compare the results and try to avoid a repetition of the least desirable ones, ^^umber your negatives to correspond with the book. How to Make Transparencies,— lu the dark room illuminated by ruby light, place a negative film side up in the printing frame ; on the surface of the negative lay a gelatine plate of the slow kind film side down. (For this purpose special plates are prepared and sold.) Put the back in the printing frame, fasten the springs and cover the frame with the focusing cloth, taking it into a room where a gas or kerosene light is burning. Hold the frame with the negative towards the light, and distant about twelve inches from it. Take off the focusing cloth, give a few seconds exposure, re-cover the printing frame and return to the dark room. Develop the gelatine plate the same as if it had received an exposure in the camera. The result should be a fine positive picture or transparency, which is fixed, washed, and dried, and then is ready to be put in a nickel-plated frame with a ground glass at the back, and hung where the light shines through it — probably to adorn a window. Fogging,— Yoggmg, as defined by Lake Price, “is an opaque film covering a negative, which obliterates the forms, preventing them from being clearly distinguished in whatever direction they may be viewed.” Thomas Sutton writes thus concerning it: ‘‘When a precipitate is thrown over the entire plate by the action of the developer, so as to obscure in the deepest shadows the transparency of the glass when looked through, it is fog.'’ The causes of fog are many. It may result from white light falling on the sensitive plate. silver about it. When troubled with fog examine the gelatine plate, and if the edges which were protected by the rabbeted edge of the holder, are clear, the fault is chargeable to the development, as the plate was evidently over-exposed and the developer not moditied to meet the case. If the fog is all over the plate it may have come from Avliite lights, from an alkaline oxalate, from under-exposure and forcing the development. The above weights are those usually adopted in formulas, and are what are used in the foregoing chapters. As the amateur advances in the picture making art he will without doubt read up in photographic literature, a course which cannot be too highly commended. He will also be inclined to experiment a little. It is an undisputed fact that to the amateur, photography owes fully as much for progress and inventive skill as to the professional photographer. Photography in England is indebted during many years past for improvements and discoveries almost wholly to the amateur’s researches and experiments. It is safe to assert that the amateur in this country of ingenuity. In trying different formulas, many of which are written by the French standard of weights and measures, the following tables will save a considerable amount of figuring, bother and failure. French Fluid Meastires,—^\iQ cubic centimetre usually represented by c. c.” is the unit of the French measurement for liquids. It contains nearly seventeen minims of water; in reality, it contains 16.896 minims. The weight of this quantity of water is one gramme. Hence it will be seen that the cubic centimetre and the gramme bear to each other the same relation as our drachms for solids and the drachms for fluids, or as the minim and the grain. The following table will prove to be sufficiently accurate for photographic purposes : The Conversion of French into English Weight, — Although a gramme is equal to 15.4346 gi’ains, the decimal is one which can never be used by photographers ; hence in the following table it is assumed to be 15-^ grains, which is the nearest approach that can be made io practical accuracy: Measuring with a Glass Graduate, — Qn the graduated glass you will find lines and figures as shown by the diagram below. The figures 1, 2, 3 and 4, on the left hand of the center line, represent ounces, and so also does the mark 5 designate the same. The short lines between the ounce lines, 1, 2, 3, 4, represent half ounces. On the lower right hand side of the center line you will find the figures 2, 4, 6 and 8. These represent drachms ; and the mark or character 3 is used to denote drachms. Example : To measure two ounces and six drachms, fill the graduate to the line with figure 2 at left hand side, pour this out into the vessel designed for the solution, then fill the graduate to the line with figure 6 on the I’ight hand side ; this is six drachms. Add this to the two ounces just measured, which gives you two ounces and six drachms. INSTANTANEOUS PHOTOGRAPHY. Considerable is heard about instantaneous photography at the present time. It is a subject that interests every one. When made practicable the photographer eagerly seized hold of the lightning process, applied it in taking the pictures of babies and restless children, and in many other ways. It is enough to lure any one into amateur photography, the very thought of picturing animated objects distinctly with all of the appearance of motion instantly arrested. The amateur may infer that the appliances for securing instantaneous pictures are very complicated. Not at all ! It is necessary to use gelatine plates of great sensitiveness. These are regularly kept on hand by dealers in photographic goods. The second requisite is that the lens used on the camera should be provided with a drop, as shown in figure 8, and described on page 26 ; or else that instantaneous shutters be fitted on to the lens or camera. The day chosen for taking the picture should be a bright one, and the time between ten a.m. and two p.M. is much to be preferred. See that the object to be photographed is brightly illuminated on the side toward the camera. Suppose a passing steamboat first calls into use the instantaneous drop on a lens you possess. Your ambition is suddenly awakened when the boat looms up in the distance, and you plant the tripod and point the camera toward where it will soon pass. Judge how far it will be away from you as it glides by, and obtain an approximate focus for this distance. If possible focus upon an object as remote as the steamboat will be in passing the point where the picture is to be taken. Secure the focus by this method, or by using your own judgment. If the drop is not already in the lens put it in, and hold it up by a turn of the button underneath the lens. Substitute a holder for the ground glass. As the steamboat is now near at hand, draw out the dark slide, separating the sensitive plate from the camera, and lay it on top of the latter. Stand behind the camera grasping the cord attached to the button holding up the instantaneous drop. Keep cool as an old hunter, glance your eyes over the top of the camera, and when the boat arrives at a point directly in the line that the lens points to, pull the cord. As the opening in the drop passes through the lens the light flashes through the aperture to the gelatine plate, and the image is impressed there. Is there any other demonstration needed of the rapidity with which light travels ? The amateur may have been nervous, and have pulled the cord too soon. Instead of the whole steamboat, he finds but the forward half of it when the picture is brought out, or, on the other liand, only tlie stern and the wake of the boat may be caught. Sport, like shooting at birds in their flight, cannot be more exciting and exhilarating. If the amateur shoots ” at a steamboat with his camera and hits a barge, lie will succeed better upon the next trial. The fall of the instantaneous drop by the law of gravitation will do for the first attempt; after a time the amateur will scheme and contrive by the use of an elastic band over the top of the drop, or by some other device, to shorten the exposure. The ambition to reduce the time from J-g- to ^ second and less, is racers excel all previous records of time. Shootino^ vachts that are dashin^: alone: throuo:h the waves under full sail, is a favorite accomplishment of the full fledged amateur. The beauty and life of the yacht may be portrayed perfectly. The only cautions I have to give, are, do not attempt too much at first in instantaneous work ; and the other piece of advice relates to the development of gelatine plates exposed but for a fractional part of a second. More care is needed than for the ordinary plates. My plan is to mix a fresh developer for each plate, consisting of two ounces of oxalate of potash solution, and a quarter of an ounce of the iron solution ; should this prove too weak, more iron solution may be added, but do not put in too much. When the details are brought out, pour ofl the developer, and flow over the plate some of the old oxalate developer as described on page 49. This will give density without danger of fogging the plate. Wash and fix, then wash and dry. After tlie negative is dry, if on examination it requires to be strengthened, proceed as follows: Lay the plate, film side up, in a tray containing clear water, while you mix the intensifying solution. In thirty-two ounces of water (one quart) dissolve one ounce of chloride of ammonia, and one ounce chloride of mercury. Pour off the water from the plate, and cover it with some of the above mercury solution diluted one half with water (that is, an equal part of the solution and water). Leave this on the plate until it has uniformly whitened, wliich will take but a lew seconds, then pour it off and wash the plate well; also rinse out the tray, into which replace the plate, film side up. Take four ounces of water, and to it add one drachm of liquid ammonia ; pour this on the plate, so it flows quickly and evenly over it. The negative will turn dark brown. As soon as it has done so, remove it from the tray, wash, and set it up to dry. the tray. Allusion was made in the introductory chapter to taking pictures of horses while they were speeding around the race track. The method by which this , was accomplished has been so often described that repetition is unnecessary. Some achievements last summer of the well known veteran photographic journalist, Mr. J. Traill Taylor, deserve mention. From the deck of a steamer plying out to a pleasure retreat on Long Island Sound, he ‘‘ shot ” at and secured the pictures of yachts skimming along in an opposite course. Again, on Boston Bay, in a little steamer that tossed about like a cockle sheli, the temptation to point his lens at some passing boats could not be resisted, so he did not try to withstand the allurement. It \vas of no use to fasten the camera on to the tripod ; better sea legs were required, and these were supplied by the photographic litterateur. Placing the camera under one arm, at the right moment he touched the trigger, releasing the instantaneous drop, light flashed through the lens, and fixed upon the sensitive plate the impression of an animated marine view. Pity the man who could not appreciate such sport. In his journalistic capacity, Mr. Taylor may be called upon to record many skillful instantaneous shots made by men who, after reading this, will strive to outdo him with feats more wonderful than his. STEREOSCOPIC PICTURES. How to Make and Mount Them, — The camera used to make stereoscopic pictures should take a 5 x 8 inch plate in the holder, have an upright division through the center, and upon the front board a pair of matched view lenses screwed into the flanges. Such are the requisites for this special service. Make sure that the central partition called a stereo-division, is fastened in place. Some discerameiit is needed in selecting the subject for a stereo-view. If the camera points to a distant hillside and there is no near object included in the range, the view will appear flat when seen through the stereoscope, and will not seem to stand out from the mount. There should be included in the image reflected on the ground glass a near as well as the more remote view. Some shrubbery, the stump of a tree, or any distinct and still object will answer. Stereo pictures made upon this principle have the most seeming actuality about them. If the two pictures seen upon the ground glass are exactly alike, it is a proof that the lenses in use are well matched. After focusing put the plate holder up in place of the ground glass. . As it is essential to success that the exposure of the two lenses should be made at the same time, place the focusing cloth on top of the camera, falling over to cover the lenses, and keep the cloth tightly drawn over them. Pull out the dark slide, and as usual lay it on top of the camera. Now all is in readiness. Paise the focusing cloth quickly. Do this so that light will enter the apertures in the lenses simultaneously. After a proper length of exposure, drop the focusing cloth over the lenses, and replace the dark slide. Follow directions in Chapter lY. for the development of the plate, but use care not to get one side of it more intense than the The distance between each of the lines and the perpendicular D (7, should be inches, and from the base line to the crown of both arches 3\| inches. over the right hand form pencilled thereon, and vice versa. Take in the best portion of the subject. With care move the negative so that the line A B will pass through similar objects in both halves; also adjust the negative to have the perpendicular 0 D pass through defined lines or objects in the right half. With a sharp pointed instrument scratch on the negative, using a straight edged ruler, the line A B, also the line B. Shift the negative so that the perpendicular 0 D will intersect points or objects corresponding to those in the otlier half ; at the same time the scratched base line must coincide with, or be directly above the line A B on the gronnd glass. Now scratch the left hand line and the negative will be ready for printing. All of the prints made will show a black base line, and the two outside ones E E. Turn the prints face downward and upon the back of the right hand half mark with a pencil the letter Z, and on the left hand picture the letter E. Now reverse the prints to have the face upwards. It is to be hoped that you have available a glass form 3i inches wide by 3s inches high, with an arch top. Set down this form upon each print alternately so that the lower edge will be on the line A B^ and one side on one of the lines EJ. With a sharp knife or a Robinson trimmer cut closely around the form. The Robinson triiiimer is suggested because it is so desirable that it has the commendation of photographers everywhere. Always cut the prints on a light of glass. In mounting the prints on the card, put the one marked L on the left hand side, and the one marked R on the right side, and have the two edges meet in the center of the card ; also have an equal margin above and below the pictures. If you can avail yourself of a printing press or hand stamp with movable type, and chose to do so, you can print on tine tissue paper the name of the picture or locality of the view. In printing from the negative this piece of tissue paper is laid on the face of the negative in one corner so that the lettering will copy on to the print in the place shown by dotted lines on figure 27. Thin tissue or onion skin paper will not prevent the printing of any part of the negative ; the effect is to make the operation a slower one. The instruction contained in this chapter will be pronounced quite elementary by men of experience ; the reasons why have not been given, but enough is stated to enable the amateur to secure good results. Indeed the same is true of all that precedes, and I do not imagine that any one will think that he has mastered all there is in photography after fortifying by experience the teachings of this book. - The purpose is to enable the amateur to meet with success and to furnish a stepping stone by which books more technical and profound will be made intelligible and interesting to the non-professional photographer. Very few, I think, will be satisfied with the rudiments of this truly fascinating art. CHAPTER XII. Useful Information, treating on varied topics, Fogging among them, and describing how to make Transparencies ; also giving tables of Weights and Measures. ... 73 All articles cmuTierated in the preceding pages may he obtained from any of the parties named in this Directory (American Optical Co. celebrated apparatus, Scovill Manufg Co. Goods, A. M. Collins, Son eg Co, pure cardboard, etc.), and are sold at manufacturers’ prices by any of them. Dry Plate Outfits of every descrijption, and all standard vnakes of Dry Plates, at bottom prices. 1^”Evertbody is Cordially Invited to Call and Send for PRICE LISTS.	20,046	common-pile/pre_1929_books_filtered	howtomakepicture00pric_0	public_library	public_library_1929_dolma-0013.json.gz:1722	https://archive.org/download/howtomakepicture00pric_0/howtomakepicture00pric_0_djvu.txt
Q6djKEg47l0JCAvQ	12.8: Field Names and Data Types	12.8: Field Names and Data Types Learning Objectives - Discuss field name requirements - Discuss types of data used in Microsoft Access Field Names A field name should be descriptive enough to identify the purpose of the field, without being overly long to prevent excessive typing. Enter the field name by placing the pointer in the first row of the Table Design window under the Field Name column. In order to ensure a valid field name, a field name: - Cannot exceed 64 characters, - Cannot include periods (.), exclamation points (!), accent grave (`), or brackets ([]), - Cannot include spaces, - Cannot include low-order ASCII characters, - Cannot start with a blank space. Practice Question Data Types The data type must be consistent with the data to be stored in the field. The “text” type is the most commonly used data type, including numbers that will not be added like social security or street address numbers. Here is a partial list of Access data types: \| Data Type \| Description \| \|---\|---\| \| Short text \| Alphanumeric characters \| \| Long text \| Alphanumeric characters \| \| Number \| Numeric values \| \| Large Number \| Numeric values \| \| Date/Time \| Date and time data \| \| Currency \| Monetary data \| \| AutoNumber \| Automatic number increments \| \| Yes/No \| Logical values: Yes/No, True/False, etc. \| \| OLE Objects \| Pictures, graphs, sound, video \| \| Hyperlink \| Line to an Internet resource \| \| Attachment \| External files \| \| Calculated \| Stores calculations based on other fields \| \| Lookup Wizard \| Displays data from another table \| Practice Question Contributors and Attributions - Field Names. Authored by : Robert Danielson. Provided by : Lumen Learning. License : CC BY: Attribution	387	common-pile/libretexts_filtered	https://biz.libretexts.org/Courses/Lumen_Learning/Book%3A_Computer_Applications_for_Managers_(Lumen)/12%3A_Microsoft_Access_Basic_Skills/12.08%3A_Field_Names_and_Data_Types	libretexts	libretexts-0000.json.gz:49390	https://biz.libretexts.org/Courses/Lumen_Learning/Book%3A_Computer_Applications_for_Managers_(Lumen)/12%3A_Microsoft_Access_Basic_Skills/12.08%3A_Field_Names_and_Data_Types
qP8diDBqpaP0u4b-	Self-Publishing Guide	24 Resources: Only the Open If you are writing a new textbook (or other open educational resource) or adapting an existing one, it’s important that all of the content meets open-copyright licence requirements or is in the public domain. (See Licences and Tools and Copyright and Open Licences.) Is your material really open? As the author and publisher of an open textbook, you have agreed to release your work with an open-copyright licence. However, open educational resources often include materials from external sources. (See Resources: Search and Find.) And it is the licensing conditions of these items that must be carefully examined before incorporating them in your open textbook. Follow the below steps to ensure that all material you find on for your book is open. Don’t assume that any item posted on the internet is free or free to use. - Look for the copyright notice. This information lists the copyright symbol (the letter C inside a circle) or the word “copyright” followed by the year in which the work was created, and therefore copyrighted, and the name of the copyright owner. - NOTE: A copyright notice does not automatically mean that a resource is not permitted in an open textbook. In fact, most open resources are copyrighted. - Here is an example: Copyright 2018 Lauri Aesoph. - Look for a statement of rights. This statement outlines the conditions of use or permissions granted by the copyright holder — for example using a Creative Commons licence — and is part of the “copyright notice”. - If not included, it can be assumed that the copyright holder grants no permissions and that “all rights are reserved”. - Here is an example of a copyright notice that includes a statement of rights for an openly licensed resource: Copyright 2018 Lauri Aesoph. This guide is released under a Creative Common Attribution 4.0 International Licence. - If the copyright notice, and statement of rights aren’t immediately apparent on a website, look for this information on web pages marked as “Terms and Conditions”, “Permissions”, etc. - If you can’t find a copyright notice, statement of rights, or licensing information, don’t use the material. - Even if a website is labelled as open, unless the material is clearly marked with an open-copyright licence or uses a public-domain marking, don’t use it. - If a resource is in the public domain because its copyright has expired or a work has been designated to the public domain, look for language or a logo that makes this clear. (See Appendix 1: Licences and Tools.) - Don’t assume that an old image or text found online is in the public domain. It might be a secondary source or someone’s interpretation of the original item. For example, a photograph of a centuries-old painting may be copyrighted and have restricted rights. - Don’t use a resource for which one-time permission has been granted by the creator. (Creative Commons licences permit unlimited usage). Instead, if you find material that you want to use but hasn’t been released with an open-copyright licence, contact the creator and ask if they will consider doing so. - Keep track of all external resources added to your open textbook including where and when they were found. ___________________________________________________________________________ ___________________________________________________________________________	703	common-pile/pressbooks_filtered	https://ecampusontario.pressbooks.pub/selfpublishguide/chapter/resources-only-the-open/	pressbooks	pressbooks-0000.json.gz:20169	https://ecampusontario.pressbooks.pub/selfpublishguide/chapter/resources-only-the-open/
cW7EXEH63LzL-WGw	Principles and practice of agricultural analysis. Volume 1 (of 3), Soils	PRINCIPLES AND PRACTICE —OF— AGRICULTURAL ANALYSIS. A MANUAL FOR THE ESTIMATION OF SOILS, FERTILIZERS, AND AGRICULTURAL PRODUCTS. FOR THE USE OF ANALYSTS, TEACHERS, AND STUDENTS OF AGRICULTURAL CHEMISTRY. VOLUME I. =SOILS.= BY HARVEY W. WILEY, CHEMIST OF THE U. S. DEPARTMENT OF AGRICULTURE. EASTON, PA., CHEMICAL PUBLISHING CO., 1894. COPYRIGHT, 1895, BY HARVEY W. WILEY. PREFACE TO VOLUME FIRST. In this volume I have endeavored to place in the hands of teachers and students of Agricultural Analysis, and of analysts generally, the principles which underlie the science and art of the analysis of soils and the best approved methods of conducting it. In the prosecution of the work I have drawn freely on the results of experience in all countries, but especially in the matter of the physical examinations of soils, of this country. Science is not delimited by geographic lines, but an author is not to be blamed in first considering favorably the work of the country in which he lives. It is only when he can see nothing of good outside of its own boundaries that he should be judged culpable. It has been my wish to give full credit to those from whose work the subject-matter of this volume has been largely taken. If, in any case, there has been neglect in this matter, it has not been due to any desire on my part to bear the honors which rightfully belong to another. With no wish to discriminate, where so many favors have been extended, especial acknowledgments should be made to Messrs. Hilgard, Osborne, Whitney, and Merrill, for assistance in reading the manuscript of chapters relating to the origin of soils, their physical properties, and mechanical analysis. With the wish that this volume may prove of benefit to the workers for whom it was written I offer it for their consideration. H. W. WILEY. WASHINGTON, D. C., Beginning of January, 1895. TABLE OF CONTENTS OF VOLUME FIRST. PART FIRST. _Introduction_, pp. 1–27.—Definitions; Origin of soil; Chemical elements in the soil; Atomic masses; Properties of the elements; Relative abundance of the elements; Minerals occurring in rocks; Classification of minerals. _Rocks and Rock Decay_, pp. 28–43.—Types of rocks; Microscopical Structure of Rocks; Composition of rocks; Color of rocks; Kinds of rocks; Eruptive rocks. _Origin of Soils_, pp. 43–63.—Decay of rocks; Effect of latitude on decay; Action of water; Action of vegetable life; Action of worms and bacteria; Action of air; Classification of soils; Qualities and kinds of soils; Humus; Soil and subsoil; Authorities cited in part first. PART SECOND. _Taking Samples for Analysis_, pp. 65–86.—General principles; General directions for sampling; Method of Hilgard; Official French method; Caldwell’s, Wahnschaffe’s, Peligot’s, and Whitney’s methods; Samples for moisture; Samples for permeability; Samples for staple crops; Method of the Royal Agricultural Society; Method of Grandeau; Method of Official Agricultural Chemists; Method of Lawes; Instruments for taking samples; Principles of success in sampling. _Treatment of Sample in the Laboratory_, pp. 87–93.—Preliminary examination; Treatment of loose soils; Treatment of compact soils; Miscellaneous methods; Authorities cited in part second. PART THIRD. _Physical Properties of Soils_, pp. 95–101.—The soil as a mass; Color of soils; Odoriferous matters in soils; Specific gravity; Apparent specific gravity. _Relation of Soil to Heat_, pp. 102–103.—Sources of soil heat; Specific heat; Absorption of solar heat. _Determination of Specific Heat_, pp. 104–110.—General principles; Method of Pfaundler; Variation of specific heat. _Soil Thermometry_, pp. 111–115.—General principles; Frear’s method of stating results; Method of Whitney and Marvin. _Applications of Soil Thermometry_, pp. 115–116.—Absorption of heat; Conductivity of soils for heat. _Cohesion and Adhesion of Soils_, pp. 116–117.—Behavior of soil after wetting; Methods of determining cohesion and adhesion; Adhesion of soil to wood and iron. _Absorption by Soils_, pp. 117–130.—General principles; Summary of data; Cause of absorption; Deductions of Warington, Way, and Armsby; Selective absorption of potash; Influence of surface area; Effect of removal of organic matters; Importance of soil absorption; Methods of determining absorption; Statement of results; Preparation of salts for absorption. _Relations of Porosity to Soil Moisture_, pp. 131–150.—Definition of porosity; Influence of drainage; Capacity of soil for moisture; Determination of porosity; Whitney’s method; Relation of fine soil to moisture; Wolff’s and Wahnschaffe’s method; Petermann’s method; Mayer’s method; Volumetric determination; Wollny’s method; Heinrich’s method; Effect of pressure on water capacity; Coefficient of evaporation; Determination of capillary attraction; Inverse capillarity; Determination of coefficient of evaporation; Wolff’s method; Water given off in a water-free atmosphere; Porosity of soil for gases; Determination of permeability in the field. _Movement of Water Through Soils: Lysimetry_, pp. 151–170.—Porosity in relation to water movement; Methods of water movement; Capillary movement of water; Causes of water movement; Surface tension of fertilizers; Methods of estimating surface tension; Preparation of soil extracts; Lysimetry; Relative rate of flow of water through soils; Measurement of rate of percolation; Authorities cited in part third. PART FOURTH. MECHANICAL ANALYSIS. _The Flocculation of Soil Particles_, pp. 171–185.—Relation of flocculation to mechanical analysis; Effect of potential of surface particles; Destruction of floccules; Suspension of clay in water; effect of chemical action; Theory of Barus; Physical explanation of subsidence; Separation of soil into particles of standard size; Mechanical separation; Sifting with water. _Separation of Soil Particles by a Liquid_, pp. 185–207.—Classification of methods of silt analysis; Methods depending on subsidence of soil particles; Methods of Kühn, Knop, Wolff, Moore, Bennigsen, and Gasparin; Method of Osborne; Schloesing’s method. _Separation of Soil Particles by a Liquid in Motion_, pp. 207–247.—General principles; Nöbel’s Apparatus; Method of Dietrich; Method of Masure; Method of Schöne; Mayer’s method; Osborne-Schöne method; Statement of results; Berlin-Schöne method; Hilgard’s method; Colloidal clay; Properties of pure clay; Separation of fine sediments; Weighing sediments; Classification of results; Comparison of methods. _Miscellaneous Determinations_, pp. 247–281.—Mechanical determination of clay; Effect of boiling on clay; General conclusions; Distribution of soil ingredients; Percentage of silt by classes; Interpretation of silt analysis; Number of soil particles; Surface area of soil particles; Logarithmic constants; Mineralogical examination of silt; Microscopical examination; Petrographic microscope; Forms and dimensions of particles; Silt classes; Crystal angles; Refractive index; Polarized light; Staining silt particles; Cleavage of soil particles; Microchemical examination of silt particles; Petrographic examination of silt particles; Separation of silt particles by specific gravity; Separation with a magnet; Color and transparency; Value of silt analyses; Authorities cited in part fourth. PART FIFTH. _Estimation of Gases in Soils_, pp. 282–300.—Carbon dioxid; Aqueous vapor; Maximum hygroscopic coefficient; Absorption of aqueous vapors; Oxygen and air; General method of determining absorption; Special methods; Diffusion of carbon dioxid; General conclusions; Authorities cited in part fifth. PART SIXTH. _Chemical Analysis of Soils_, pp. 301–342.—Preliminary considerations; Order of examination; Determination of water in soils; General conclusions; Estimation of organic matter in soils; Estimation of humus; Estimation of carbonates in arable soils. _Digestion of Soils with Solvents_, pp. 342–352.—Treatment with water; With water saturated with carbon dioxid; With water containing ammonium chlorid; With water containing acetic acid; Treatment with citric acid; With hydrochloric acid; With nitric acid; With hydrofluoric and sulphuric acids. _Determination of the Dissolved Matter_, pp. 352–367.—Methods of the Official Agricultural Chemists; Hilgard’s methods; Belgian methods; Bulk analysis. _Special Methods of Soil Analysis_, pp. 367–428.—Determination of potash; Potash soluble in concentrated acids; Soluble in dilute acids; Estimation as platinochlorid; German Station methods; Raulin’s method; Russian method; Italian method; Smith’s method; International method; Dyer’s method; Estimation of total alkalies and alkaline earths; French method for lime; Estimation of actual calcium carbonate; Estimation of active calcareous matter; Russian method for lime; Assimilable lime; German lime method; Estimation of magnesia; Estimation of manganese; Estimation of iron; Estimation of phosphoric acid; Estimation of sulfuric acid; Estimation of chlorin; Estimation of silica; Simultaneous estimation of different elements; Estimation of kaolin in soils. _Estimation of Nitrogen in Soils_, pp. 428–458.—Nature of nitrogenous principles; Method of Official Agricultural Chemists; Hilgard’s method; Moist combustion method of Müller; Soda-lime method; Treatment of soil containing nitrates; Volumetric method with copper oxid; Estimation of ammonia; Amid nitrogen; Volatile nitrogenous compounds; Late methods of the Official Agricultural Chemists; Authorities cited in part sixth. PART SEVENTH. _Oxidized Nitrogen in Soils_, pp. 459–496.—Organic nitrogen; Nitric and nitrous acids; Conditions of nitrification; Production of nitric and nitrous acids; Production of ammonia; Order of oxidation; Occurrence of nitrifying organisms; Nitrifying power of soils; Culture of nitrifying organisms; Isolation of nitrous and nitric ferments; Classification of nitrifying organisms; Sterilization; Thermostats for cultures; Conclusions. _Determination of Nitric and Nitrous Acids in Soils_, pp. 496–531.—Classification of methods; Extraction of nitric acid; The nitric oxid process; Schloesing’s method; Warington’s method; Spiegel’s method; Schulze-Tiemann method; DeKoninck’s method; Schmitt’s process; Merits of the ferrous salt method; Mercury and sulfuric acid method; Lunge’s nitrometer; Utility of the method; The indigo method. _Determination of Nitric Nitrogen by Reduction to Ammonia_, pp. 531–542.—Classification of methods; Method of the Official Agricultural Chemists; German method; Devarda’s method; Stoklassa’s process; Sievert’s variation; Variation of the sodium-amalgam process; Schmitt’s method; Process of Ulsch; Reduction by the electric current; Copper-zinc and aluminum-mercury couples. _Iodometric Estimation of Nitric Acid_, pp. 543–548.—Method of DeKoninck and Nihoul; Method of Gooch and Gruener. _Estimation of Nitric and Nitrous Acids by Colorimetric Comparison_, pp. 548–570.—Delicacy of the process; Hooker’s carbazol method; Phenylsulfuric acid method; Estimation of nitric in presence of nitrous acid; Metaphenylenediamin method for nitrous acid. Sulfanilic acid test; Naphthylamin process; Use of starch as indicator; Method of Chabrier; Ferrous salt method; Potassium ferrocyanid method; Collecting samples of rain water. _Determination of Free and Albuminoid Ammonia_, pp. 570–575.—Nessler process; Ilosvay’s reagent; Authorities cited in part seventh. PART EIGHTH. _Special Examination of Waters_, pp. 576–583.—Total solid matter; Estimation of chlorin; Estimation of carbon dioxid; Boric acid. _Special Treatment of Muck Soils_, pp. 583–591.—Sampling; Water content; Organic carbon and hydrogen; Total volatile matter; Estimation of sulfur; Estimation of phosphoric acid; Estimation of humus; Special study of soluble matters in muck. _Unusual Constituents of Soil_, pp. 580–593.—Estimation of copper; Estimation of lead; Estimation of zinc; Estimation of boron; Authorities cited in part eighth. Index, pp. 594–607. =CORRECTIONS.=—Page 112, second line from bottom, read “Fig. 14” instead of “13.” Page 158, insert “and determining soluble matters therein” after “flow” in paragraph =172=, third line. Page 468, paragraph =423=, read “calcium carbonate about 200 milligrams,” instead of “calcium carbonate, or gypsum fifty milligrams.” Page 557, read “red-yellow” instead of “blue” in seventh line from bottom. ILLUSTRATIONS TO VOLUME FIRST. Page. Plate, figures 1–6. To face 29 Figure 7. Microscopic structure of sandstone 36 „ 8. Microstructure of crystalline limestone 39 „ 9. Microstructure of Gneiss 40 Plate, figure 10. View on the broad branch of Rock Creek, 48 Washington, D. C., to face Figure 11. 82 „ 12. 84 „ 13. Regnault’s apparatus for determining the specific heat 105 of soils „ 14. Soil thermometer 113 „ 15. Zalomanoff’s apparatus for determining absorption of 126 salts by soils „ 16. Müller’s apparatus to show absorption of salts by 127 soils Plate, figure 17. Capacity of the fine soil for holding moisture. 136 Method of Wolff modified by Wahnschaffe, to face Figure 18. Fuelling’s apparatus 140 „ 19. Apparatus to show capillary attraction of soils for 145 water Plate, figure 20. Apparatus for determining coefficient of 148 evaporation, to face Figure 21. Method of Heinrich 150 „ 22. Method of Welitschowsky 162 „ 23. Ground plan and vertical section of lysimeters and 166 vaults showing position of the apparatus Plate, figure 24. Deherain’s apparatus for collecting drainage 168 water, to face Figure 25. Knop’s silt cylinder 190 „ 26. Siphon cylinder for silt analysis 191 „ 27. Bennigsen’s silt flasks 195 „ 28. Nöbel’s elutriator 208 „ 29. Dietrich’s elutriator 209 „ 30. Masure’s silt apparatus 211 „ 31. Schöne’s elutriator 212 „ 32. Schöne’s elutriator outflow tube 213 „ 33. Schöne’s elutriator, arrangement of apparatus 214 „ 34. Schöne’s apparatus for silt analysis, modified by 221 Mayer „ 35. Hilgard’s churn elutriator 226 „ 36. Improved Schöne’s apparatus with relay 228 „ 37. 257 Plate, figure 38. To face 264 „ figures 39–44. „ „ figures 45–50. „ „ figures 51–56. „ Figure 57. Machine for making mineral sections 267 „ 58. Thoulet’s separating apparatus 272 „ 59. Harada’s apparatus 275 „ 60. Brögger’s apparatus 276 „ 61. Apparatus of Wülfing 277 „ 62. Schloesing’s soil-tube for collecting gases 291 „ 63. Schloesing’s apparatus for collecting gases from soil 292 „ 64. Schloesing’s apparatus for determination of carbon 293 dioxid „ 65. Knorr’s apparatus for the determination of carbon 338 dioxid „ 66. Bernard’s calcimeter 339 „ 67. Smith’s muffle for decomposition of silicates 381 „ 68. Apparatus by Sachsse and Becker 401 Plate, figures 69 and 70. To face 480 Figure 71. Sterilizing oven 491 „ 72. Autoclave sterilizer 492 „ 73. Arnold’s sterilizer 493 „ 74. Lautenschläger’s thermostat 494 „ 75. Schloesing’s apparatus for nitric acid 501 „ 76. Warington’s apparatus for nitric acid 505 „ 77. Spiegel’s apparatus for nitric acid 509 „ 78. Schulze-Tiemann’s nitric acid apparatus 511 „ 79. DeKoninck’s apparatus 514 „ 80. End of delivery-tube 514 „ 81. Schmidt’s apparatus 516 „ 82. Lunge’s nitrometer 519 „ 83. Lunge’s improved apparatus 521 „ 84. Lunge’s analytic apparatus 523 „ 85. Stoklassa’s nitric acid apparatus 535 „ 86. Variation of the sodium amalgam process 537 „ 87. McGowan’s apparatus for the iodometric estimation of 544 nitric acid „ 88. Apparatus of Gooch and Gruener 547 „ 89. Method of Chabrier 566 „ 90. Schaeffer’s nitrous acid method 568 „ 91. Retort for distilling ammonia 572 „ 92. Gooch’s apparatus for boric acid 581 „ 93. Apparatus for determining sulfur 587 PART FIRST. INTRODUCTION. =1. Definitions.=—The term soil, in its broadest sense, is used to designate that portion of the surface of the earth which has resulted from the disintegration of rocks and the decay of plants and animals, and which is suited, under proper conditions of moisture and temperature, to the growth of plants. It consists, therefore, chiefly of mineral substances, together with some products of organic life, and of certain living organisms whose activity may influence vegetable growth either favorably or otherwise. The soil also holds varying quantities of gaseous matter and of water, which are important factors in its functions. =2. Origin Of Soil.=—Agriculturally considered, the soil proper is the older and more thoroughly disintegrated superficial layer of the earth, which has been longest exposed to weathering and the influences of organic life. It is usually from six to twelve inches, but occasionally several feet in depth. The subsoil, which lies directly under this, is not as a rule so thoroughly disintegrated, since it is protected in a measure by the overlying soil. It usually contains less organic matter than the soil. There is a freer circulation of air in the soil than in the subsoil, and the metallic elements usually exist therein as higher oxids. There is usually a notable difference in color between the soil and subsoil, and frequently a very sharp color line separating the two. Geologically considered, the soil is that portion of the earth’s crust which has been more or less thoroughly disintegrated by weathering and other forces from the original rock formations, or from the sedimentary rocks, or from the unconsolidated sedimentary material. The soil has, therefore, the same essential constitution as the general mass of the earth, except that this débris has been subjected to the solvent action of water and the influence of vegetable growth. Preliminary to the proper understanding of the methods of the analysis of soils, there should be some definite knowledge concerning the composition of the earth’s crust, so that the analyst may understand more thoroughly the origin and nature of the material he has to deal with, and thereby be better equipped for his work. =3. The Chemical Elements Present in the Soil.=—The chemical elements present in the soil are naturally some or all of those which were present in the original rocks. For analytical purposes relating to agriculture, it is not necessary to take into account the rare elements which may occur in the soil, but only those need be considered which are present in some quantity and which enter as an important factor into plant growth. Of the whole number of chemical elements less than twenty are of any importance in soil analysis. These elements may be grouped into two classes, the non-metals, and the metals as follows: Non-metals. Metals. Oxygen, Aluminum, Silicon, Calcium, Carbon, Magnesium, Sulfur, Potassium, Hydrogen, Sodium, Chlorin, Iron, Phosphorus, Manganese, Nitrogen, Barium. Fluorin, Boron. =4. Atomic Masses.=—For the purpose of facilitating the calculation of results the latest revised table of atomic masses is given below. All the known elements are included in this table for the convenience of analysts who may have to study some of the rarer elements in the course of their work. This table represents the latest and most trustworthy results reduced to a uniform basis of comparison with oxygen = 16 as starting point of the system. No decimal places representing large uncertainties are used. When values vary, with equal probability on both sides, so far as our present knowledge goes, as in the case of cadmium (111.8 and 112.2), the mean value is given in the table. TABLE OF ATOMIC MASSES OF THE ELEMENTS. Revised by F. W. Clarke, Chief Chemist of the United States Geological Survey, to January 1st, 1894. ────────────┬───────┬─────── Name. │Symbol.│Atomic │ │ mass. ────────────┼───────┼─────── Aluminum │Al │ 27 Antimony │Sb │ 120 Arsenic │As │ 75 Barium │Ba │ 137.43 Bismuth │Bi │ 208.9 Boron │B │ 11 Bromin │Br │ 79.95 Cadmium │Cd │ 112 Cesium │Cs │ 132.9 Calcium │Ca │ 40 Carbon │C │ 12 Cerium │Ce │ 140.2 Chlorin │Cl │ 35.45 Chromium │Cr │ 52.1 Cobalt │Co │ 59 Columbium[A]│Cb[Nb] │ 94 Copper │Cu │ 63.6 Erbium │Er │ 166.3 Fluorin │F │ 19 Gadolinium │Gd │ 156.1 Gallium │Ga │ 69 Germanium │Ge │ 72.3 Glucinum[B] │Gl[Be] │ 9 Gold │Au │ 197.3 Hydrogen │H │ 1.008 Indium │In │ 113.7 Iodin │I │ 126.85 Iridium │Ir │ 193.1 Iron │Fe │ 56 Lanthanum │La │ 138.2 Lead │Pb │ 206.95 Lithium │Li │ 7.02 Magnesium │Mg │ 24.3 Manganese │Mn │ 55 Mercury │Hg │ 200 Molybdenum │Mo │ 96 Neodymium │Nd │ 140.5 Nickel │Ni │ 58.7 Nitrogen │N │ 14.03 Osmium │Os │ 190.8 Oxygen[C] │O │ 16 Palladium │Pd │ 106.6 Phosphorus │P │ 31 Platinum │Pt │ 195 Potassium │K │ 39.11 Praseodymium│Pr │ 143.5 Rhodium │Rh │ 103 Rubidium │Rb │ 85.5 Ruthenium │Ru │ 101.6 Samarium │Sm │ 150 Scandium │Sc │ 44 Selenium │Se │ 79 Silicon │Si │ 28.4 Silver │Ag │ 107.92 Sodium │Na │ 23.05 Strontium │Sr │ 87.6 Sulfur │S │ 32.06 Tantalum │Ta │ 182.6 Tellurium │Te │ 125 Terbium │Tb │ 160.0 Thallium │Tl │ 204.18 Thorium │Th │ 232.6 Thulium │Tu │ 170.7 Tin │Sn │ 119 Titanium │Ti │ 48 Tungsten │W │ 184 Uranium │U │ 239.6 Vanadium │V │ 51.4 Ytterbium │Yb │ 173 Yttrium │Yt │ 89.1 Zinc │Zn │ 65.3 Zirconium │Zr │ 90.6 ────────────┴───────┴─────── Footnote A: Has priority over niobium. Footnote B: Has priority over beryllium. Footnote C: Standard or basis of the system. PROPERTIES OF THE ELEMENTS. Following is a brief description of the most important elements occurring in the earth’s crust in respect of their relations to agriculture. =5. Oxygen= exists in the free gaseous state in the atmosphere of which it constitutes about one-fifth by bulk, whilst in combination with other elements it forms nearly half the weight of the solid earth, and eight-ninths by weight of water. It enters into combination with all the other elements, except fluorin, forming what are known as oxids, and with many of the elements it unites in several proportions, forming oxids of different composition. Combined with silicon, carbon, sulfur, and phosphorus, it forms an essential part of the silicates, carbonates, sulfates, and phosphates, most of which are very abundant and all of which are very widely distributed in the earth’s crust. In this form it is exceedingly stable and is rarely set free. With the exception of the oxids of silicon these oxids seldom occur uncombined with the metals as constituents of rocks or soils. The oxids of iron very commonly occur as such in rocks and soils, and play a very important part in organic life. The several oxids of iron very frequently determine the color of soils; as the iron in a soil is more or less oxidized, or as it is exposed more or less to access of air, the color of the soil changes. These oxids of iron also play an important part in the absorption capacities of soils for moisture and other physical conditions of soils, and also in the oxidation of organic matters in the soil. Many organic substances, and even the roots of growing plants when deprived of free access of air, can readily secure oxygen from the iron oxid, thus reducing the iron to a lower form of oxidation, the oxygen being used for the oxidation of the organic matter or for the needs of the growing plant; while the lower oxid of iron can more readily take up oxygen of the air and again be converted into a higher oxid, ready again to give up a part of its oxygen and thus serve as a carrier. =6. Silicon= never occurs in the free state, but combined with oxygen it forms silica, which constitutes more than one-half of the earth’s crust. The oxid of silicon occurs in the very common form of quartz, and likewise, as silicate of alumina, lime or magnesia. Silicon forms an essential part of many minerals, such as the feldspars, amphiboles, pyroxenes, and the micas, besides being an essential ingredient of many other minerals. Silica is relatively very slightly affected by the ordinary forces concerned in the decay of rocks, and even after the crystals of feldspars, micas, and other common minerals occurring in rocks have been disintegrated the silica remains as hard grains of sand, forming the bulk of most soils. By far the larger part of silicon in soils is in the form of grains of quartz or silica. This form, however, is probably chemically inert in regard to plant growth, but it plays a very important part in the physical structure of soils and in the physical relation of soils to plant growth. =7. Carbon= as an elementary substance occurs as diamond and graphite and in an impure form as anthracite and bituminous coals. In peats and mucks carbon is the chief constituent. This substance is also contained in the organic matters of the soil known as humus, and the relation of the carbon to nitrogen often throws important light upon the amount and character of the nitrogenous matters. In composition with oxygen it forms the chief food of growing plants, the carbon of the carbon dioxid of the air being elaborated into the tissue of the plants and the oxygen returned to the atmosphere. The content of carbon dioxid in the air is from three to five parts per thousand by volume. As carbonates this element helps to form some of the most important ingredients of the earth’s crust, namely, limestones, marbles, dolomites, etc., and in an organic form it is found in the shells of the crustaceans. The calcareous matter of the soil, that is, the carbonates of the earths therein found, are of the highest importance from an agricultural point of view. The carbonates in the soil not only favor the process of converting nitrogenous bodies into forms suitable for plant food, but also exert a most potent influence on the physical state of the soil and its capacity for holding water and permitting its flow to and from the rootlets of the plant. =8. Sulfur= occurs in nature in both the free and combined state. In the free state it is found in volcanic regions such as Sicily, Iceland, and the western United States. Its usual form of occurrence is in combination with the metals to form sulfids, or with oxygen and a metal to form sulfates. Sulfur and iron combine to form iron pyrites or iron disulfid (FeS₂), while sulfur, oxygen, and calcium are found in gypsum, an important fertilizing compound. Sulfur plays an important part in the nourishment of plants, being found in them both as sulfuric acid and in organic compounds. Methods for estimating the sulfur in both forms will be found in another part of this manual. =9. Hydrogen= is a colorless, invisible gas, without taste or smell. It occurs free in small proportions in certain volcanic gases, and in natural gas, but its most common form is in combination with oxygen as water (H₂O), of which it forms 11.13 per cent by weight. It also occurs in combination with carbon to form the hydrocarbons, such as the mineral oils (petroleum, etc.) and gases. Hydrogen is of no importance to agriculture in a free state, but water is the most important of all plant foods. =10. Chlorin= occurs free in nature only in limited amounts and in volcanic vents. Its most common form is in combination with hydrogen, forming hydrochloric acid, or with the metals to form chlorids. It combines with sodium to form sodium chlorid or common salt (NaCl), which is the most abundant mineral ingredient in sea water and which can usually be detected in rain and ordinary terrestrial waters. In this form, also, it exists as extensive beds of rock salt, which is mined for commercial purposes. Chlorin is found uniformly in plants and must be regarded as an essential constituent thereof. Common salt applied to a soil modifies its power of attracting and holding water. =11. Phosphorus= never occurs in nature in a free state but exists in combination in greater or less quantities in all soils. Its combinations are also found in large deposits of minerals known as phosphorite and apatite and as so-called pebble deposit and phosphate rock. Phosphorus in some sort of combination is one of the most essential elements in animal and plant food. In animals its compounds form almost all of the mineral matter of the bones, and in plants they are the chief constituents of the ash of seeds. The mineral deposits of phosphorus, as well as bones, are chiefly tri-calcium phosphate, while the slag compound resulting from the basic treatment of iron ores rich in phosphorus is a tetra-calcium salt. The pebble deposits and some rock phosphates are supposed to be of organic origin, derived from the remains of marine, terrestrial, and aerial animals. Cereal crops remove about twenty pounds of phosphoric acid per acre from the soil annually and grass crops about twelve pounds. The total phosphoric acid removed annually by the cereal and grass crops in the United States is nearly four billion pounds. Gautier[1] calls attention to the fact that the oldest phosphates are met with in the igneous rocks such as basalt, trachyte, etc., and even in granite and gneiss. It is from these inorganic sources, therefore, that all phosphatic plant food must have been drawn. In the second order in age Gautier places the phosphates of hydro-mineral origin. This class not only embraces the crystalline apatites but also those phosphates of later formation formed from hot mineral waters in the jurassic, cretaceous, and tertiary deposits. These deposits are not directly suited to nourish plants. The third group of phosphates in order of age and assimilability embraces the true phosphorites containing generally some organic matter. They are all of organic origin. In caves where animal remains are deposited there is an accumulation of nitrates and phosphates. Not only do the bones of animals furnish phosphates but they are also formed in considerable quantities by the decomposition of substituted glycerids such as lecithin. The ammonia produced by the nitrification of the albuminoid bodies combines with the free phosphoric acid thus produced, forming ammonium or diammonium phosphates. The presence of ammonium phosphates in guanos was first noticed by Chevreul more than half a century ago. If such deposits overlay a pervious stratum of calcium carbonate, such as chalk, and are subject to leaching a double decomposition takes place as the lye percolates through the chalk. Acid calcium phosphate and ammonium carbonate are produced. By further nitrification the latter becomes finally converted into calcium nitrate. In like manner aluminum phosphates are formed by the action of decomposing organic matter on clay. Davidson,[2] explains the origin of the Florida phosphates by suggesting that they arose chiefly through the influx of animals driven southward during the glacial period. According to his supposition the waters of the ocean, during the cenozoic period contained more phosphorus than at the present time. The waters of the ocean over Florida were shallow and the shell fish existing therein may have secreted phosphate as well as carbonate of lime. This supposition is supported by an analysis of a shell of _lingula ovalis_, quoted by Dana, in which there were 85.79 per cent of lime phosphate. In these waters were also many fishes of all kinds and their débris served to increase the amount of phosphatic material. As the land emerged from the sea came the great glacial epoch driving all terrestrial animals southward. There was, therefore, a great mammal horde in the swamps and estuaries of Florida. The bones of these animals contributed largely to the phosphatic deposits. In addition to this, the shallow sea contained innumerable sharks, manatees, whales, and other inhabitants of tropical waters, and the remains of these animals added to the phosphatic store. While these changes were taking place in the quaternary period, the Florida Peninsula was gradually rising, and as soon as it reached a considerable height the process of denudation by the action of water commenced. Then there was a subsidence and the peninsula again passed under the sea and was covered with successive layers of sand. The limestones during this process had been leached by rain water containing an excess of carbon dioxid. In this way the limestones were gradually dissolved while the insoluble phosphate of lime was left in suspension. During this time the bones of the animals before mentioned by their decomposition added to the phosphate of lime present in the underlying strata, while some were transformed into fossils of phosphate of lime just as they are found to-day in vast quantities. Wyatt,[3] explains the phosphate deposits somewhat differently. According to him, during the miocene submergence there was deposited upon the upper eocene limestones, more especially in the cracks and fissures resulting from their drying up, a soft, finely disintegrated calcareous sediment or mud. The estuaries formed during this period were swarming with animal and vegetable life, and from this organic life the phosphates were formed by decomposition and metamorphism due to the gases and acids with which the waters were charged. After the disappearance of the miocene sea there were great disturbances of the strata. Then followed the pliocene and tertiary periods and quaternary seas with their deposits and drifts of shells, sands, clays, marls, bowlders, and other transported materials supervening in an era when there were great fluctuations of cold and heat. By reason of these disturbances the masses of the phosphate deposits which had not been infiltrated in the limestones became broken up and mingled with the other débris and were thus deposited in various mounds or depressions. The general result of the forces which have been briefly outlined, was the formation of bowlders, phosphatic débris, etc. Wyatt therefore classifies the deposits as follows: 1. Original pockets or cavities in the limestone filled with hard and soft rock phosphates and débris. 2. Mounds or beaches, rolled up on the elevated points, and chiefly consisting of huge bowlders of phosphate rock. 3. Drift or disintegrated rock, covering immense areas, chiefly in Polk and Hillsboro counties, and underlying Peace River and its tributaries. Darton,[4] ascribes the phosphate beds of Florida to the transformation of guano. According to this author two processes of decomposition have taken place. One of these is the more or less complete replacement of the carbonate by the phosphate of lime. The other is a general stalactitic coating of phosphatic material. Darton further calls attention to the relation of the distribution of the phosphate deposits as affecting the theory of their origin, but does not find any peculiar significance in the restriction of these deposits to the western ridge of the Florida peninsula. As this region evidently constituted a long narrow peninsula during early miocene time it is a reasonably tentative hypothesis that during this period guanos were deposited from which was derived the material for the phosphatization of the limestone either at the same time or soon after. Darton closes his paper by saying that the phosphate deposits in Florida will require careful, detailed geologic exploration before their relations and history will be fully understood. According to Dr. N. A. Pratt the rock or bowlder phosphate had its immediate origin in animal life and to his view the phosphate bowlder is a true fossil. He supposes the existence of some species in former times in which the shell excreted was chiefly phosphate of lime. The fossil bowlder, therefore, becomes the remains of a huge foraminifer which had identical composition in its skeleton with true bone deposits or of organic matter. Perhaps the most complete exposition of the theory of the recovery of waste phosphates, with especial reference to their deposit in Florida, has been given by Eldridge.[5] He calls attention to the universal presence of phosphates in sea water and to the probability that in earlier times, as during the miocene and eocene geologic periods, the waters of the ocean contained a great deal more phosphate in solution than at the present time. He cites the observations of Bischof, which show the solubility of different phosphates in waters saturated with carbon dioxid. According to these observations apatite is the most insoluble form of lime phosphate, while artificial basic phosphate is the most soluble. Among the very soluble phosphates, however, are the bones of animals, both fresh and old. Burnt bones, however, are more soluble than bones still containing organic matter. Not only are the organic phosphates extremely soluble in water saturated with carbon dioxid, but also in water which contains common salt or chlorid of ammonium. The presence of large quantities of common salt in sea water would, therefore, tend to increase its power of absorbing lime phosphates of organic origin. It is not at all incredible, therefore, to suppose that at some remote period the waters of the ocean, as indicated by these theories, were much more highly charged with phosphates in solution than at the present time. According to Eldridge, the formation of the hard-rock and soft phosphates may be ascribed to three periods: First, that in which the primary rock was formed; second, that of secondary deposition in the cavities of the primary rock; third, that in which the deposits thus formed were broken up and the resulting fragments and comminuted material were redeposited as they now occur. “The first of these stages began probably not later than the close of the older miocene, and within the eocene area it may have begun much earlier. Whether the primary phosphate resulted from a superficial and heavy deposit of soluble guanos, covering the limestones, or from the concentration of phosphate of lime already widely and uniformly distributed throughout the mass of the original rock, or from both, is a difficult question. In any event, the evidence indicates the effect of the percolation of surface waters, highly charged with carbonic and earth acids, and thus enabled to carry down into the mass of the limestone dissolved phosphate of lime, to be redeposited under conditions favorable to its separation. Such conditions might have been brought about by the simple interchange of bases between the phosphate and carbonate of lime thus brought together, or by the lowering of the solvent power of the waters through loss of carbonic acid. The latter would happen whenever the acid was required for the solution of additional carbonate of lime, or when, through aeration, it should escape from the water. The zone of phosphate deposition was evidently one of double concentration, resulting from the removal of the soluble carbonate thus raising the percentage of the less soluble phosphate, and from the acquirement of additional phosphate of lime from the overlying portions of the deposits.” “The thickness of the zone of phosphatization in the eocene area is unknown, but it is doubtful if it was over twenty feet. In the miocene area the depth has been proved from the phosphates _in situ_ to have been between six and twelve feet.” The deposits of secondary origin, according to Eldridge, are due chiefly to sedimentation, although some of them may have been due to precipitation from water. This secondary deposition was kept up for a long period, until stopped by some climatic or geologic change. The deposits of phosphates thus formed in the Florida peninsula are remarkably free from iron and aluminum, in comparison with many of the phosphates of the West Indies. The third period in the genesis of the hard rock deposits embraces the time of formation of the original deposits and their transportation and storage as they are found at the present time. The geologic time at which this occurred is somewhat uncertain but it was probably during the last submergence of the peninsula. In all cases the peculiar formation of the Florida limestone must be considered. This limestone is extremely porous and therefore easily penetrated by the waters of percolation. A good illustration of this is seen on the southwestern and southern edges of Lake Okeechobee. In following down the drainage canal which has been cut into the southwest shore of the lake the edge of the basin, which is composed of this porous material may be seen. The appearance of the limestone would indicate that large portions of it have already given way to the process of solution. The remaining portions are extremely friable, easily crushed, and much of it can be removed by the ordinary dredging machines. Such a limestone as this is peculiarly suited to the accumulation of phosphatic materials, due to the percolation of the water containing them. The solution of the limestone and consequent deposit of the phosphate of lime is easily understood when the character of this limestone is considered. Shaler, as quoted by Eldridge in the work already referred to, refers to this characteristic of the limestone and says that the best conditions for the accumulation of valuable deposits of lime phosphate in residual débris appear to occur where the phosphatic lime marls are of a rather soft character; the separate beds having no such solidity as will resist the percolation of water through innumerable incipient joints such as commonly pervade stratified materials, even when they are of a very soft nature. Eldridge is also of the opinion that the remains of birds are not sufficient to account for the whole of the phosphatic deposits in Florida. He ascribes them to the joint action of the remains of birds, of land and marine animals and to the deposition of the phosphatic materials in the waters in the successive subsidences of the surface below the water line. =12. Nitrogen= as a mineral constituent of soils, is found chiefly in the form of nitrates, but, owing to their solubility, they can not accumulate in soils exposed to heavy rain-falls. The gaseous nitrogen in the soil is also of some importance, since it is in this material that the anaerobic organisms which accumulate on the rootlets of some plants probably act in the process of the fixation of atmospheric nitrogen in a form accessible to plants. Nitrogen in the free state, it is believed, is not directly absorbed into the tissues of plants. It is necessary that it be oxidized in some way to nitric acid before it can be assimilated. The importance of nitrogen as a plant food can not be too highly estimated. It is as necessary to plant growth and development as water, phosphoric acid, lime, and potash, and far more costly. While a large quantity of nitrogen exists in the air in an uncombined state, it is, nevertheless, one of the least abundant of the elements of high importance in plant nutrition. The conservation and increase of the stores of available nitrogen in the soil is one of the chief problems occupying the attention of agricultural chemistry. Nitrogen, which is not immediately available for the growth of plants, is conserved and restored by natural processes in various ways. The waste nitrogen finds its way sooner or later to the sea, and is restored therefrom in many forms. Sea-weeds of all kinds are rich in recovered nitrogen. Many years ago Forchhammer[6] pointed out the agricultural value of certain fucoids. Many other chemists have contributed important data in regard to the composition of these bodies. Jenkins[7] has shown from the analyses of several varieties of sea-weeds that in the green state they are quite equal in fertilizing value to stall manure, and are sold at the rate of five cents per bushel. These data are fully corroborated by Goessmann.[8] Wheeler and Hartwell[9] give the fullest and most systematic discussion which has been published of the agricultural value of sea-weeds. Sea-weed was used as a fertilizer as early as the fourth century, and its importance for this purpose has been recognized more and more in modern days, especially since chemical investigations have shown the great value of the food materials contained therein. To show the commercial importance of sea-weed, it is only necessary to call attention to the fact that in 1885 its value as a fertilizer in the State of Rhode Island was $65,044, while the value of all other commercial fertilizers was $164,133. While sea-weed, in a sense, can only be successfully applied to littoral agriculture, yet the extent of agricultural lands bordering on the sea is so great as to render its commercial importance of the highest degree of interest. A large amount of nitrogen is also recovered from the sea in fishes. It is shown by Atwater[10] that the edible part of fishes has an unusually high percentage of protein. In round numbers, about seventy-five per cent of the water free edible parts of fish are composed of albuminoids. Some kinds of fish are taken chiefly for their oil and fertilizing value, as the menhaden. Squanto,[11] an American Indian, first taught the early New England settlers the manurial value of fish. Immense quantities of waste nitrogen are further secured, both from sea and land, by the various genera of birds. The well-known habit of birds in congregating in rookeries during the night and at certain seasons of the year tends to bring into a common receptacle the nitrogenous matters which they have gathered and which are deposited in their excrement and in the decay of their bodies. The feathers of birds are particularly rich in nitrogen, and the nitrogenous content of the flesh of fowls is also high. The decay of remains of birds, especially if it take place largely excluded from the leaching of water, tends to accumulate vast deposits of nitrogenous matter. If the conditions in such deposits be favorable to the processes of nitrification, the whole of the nitrogen, or at least the larger part of it, which has been collected in this débris, becomes finally converted into nitric acid and is found combined with appropriate bases as deposits of nitrates. The nitrates of the guano deposits and of the deposits in caves arise in this way. If these deposits be subject to moderate leaching the nitrate may become infiltered into the surrounding soil, making it very rich in this form of nitrogen. The bottoms and surrounding soils of caves are often found highly impregnated with nitrates. While for our purpose, deposits of nitrates only are to be considered which are of sufficient value to bear transportation, yet much interest attaches to the formation of nitrates in the soil even when they are not of commercial importance. In many of the soils of tropical regions not subject to heavy rain-falls, the accumulation of these nitrates is very great. Müntz and Marcano[12] have investigated many of these soils to which attention was called first by Humboldt and Boussingault. They state that these soils are incomparably more rich in nitrates than the most fertile soils of Europe. The samples which they examined were collected from different parts of Venezuela and from the valleys of the Orinoco as well as on the shore of the Sea of Antilles. The nitrated soils are very abundant in this region of South America where they cover large surfaces. Their composition is variable, but in all of them carbonate and phosphate of lime are met with and organic nitrogenous material. The nitric acid is found always combined with lime. In some of the soils as high as thirty per cent of nitrate of lime have been found. Nitrification of organic material takes place very rapidly the year round in this tropical region. These nitrated soils are everywhere abundant around caves, as described by Humboldt, caves which serve as the refuge of birds and bats. The nitrogenous matters, which come from the decay of the remains of these animals, form true deposits of guano which is gradually spread around, and which, in contact with the limestone and with access of air, suffers complete nitrification with the fixation of the nitric acid by the lime. Large quantities of this guano are also due to the débris of insects, fragments of elytra, scales of the wings of butterflies, etc., which are brought together in those places by the millions of cubic meters. The nitrification, which takes place in these deposits, has been found to extend its products to a distance of several kilometers through the soil. In some places the quantity of the nitrate of lime is so great in the soils that they are converted into a plastic paste by this deliquescent salt. The theory of Müntz and Marcano in regard to the nitrates of soils, especially in the neighborhood of caves, is probably a correct one, but there are many objections to accepting it to explain the great deposits of nitrate of soda which occur in many parts of Chile. Another point, which must be considered also, is this: That the processes of nitrification can not now be considered as going on with the same vigor as formerly. Some moisture is necessary to nitrification, inasmuch as the nitrifying ferment does not act in perfectly dry soil, and in many localities in Chile where the nitrates are found it is too dry to suppose that any active nitrification could now take place. The existence of these nitrate deposits has long been known.[13] The old Indian laws originally prohibited the collection of the salt, but nevertheless it was secretly collected and sold. Up to the year 1821, soda saltpeter was not known in Europe except as a laboratory product. About this time the naturalist, Mariano de Rivero, found on the Pacific coast, in the Province of Tarapacá, immense new deposits of the salt. Later the salt was found in equal abundance in the Territory of Antofogasta and further to the south in the desert of Atacama, which forms the Department of Taltal. At the present time the collection and export of saltpeter from Chile is a business of great importance. The largest export which has ever taken place in one year was in 1890, when the amount exported was 927,290,430 kilograms; of this quantity 642,506,985 kilograms were sent to England and 86,124,870 kilograms to the United States. Since that time the imports of this salt into the United States have largely increased. According to Pissis[14] these deposits are of very ancient origin. This geologist is of the opinion that the nitrate deposits are the result of the decomposition of feldspathic rocks; the bases thus produced gradually becoming united with the nitric acid provided from the air. According to the theory of Nöllner[15] the deposits are of more modern origin and due to the decomposition of marine vegetation. Continuous solution of soils, gives rise to the formation of great lakes of saturated water, in which occurs the development of much marine vegetation. On the evaporation of this water, due to geologic isolation, the decomposition of nitrogenous organic matter causes generation of nitric acid, which, coming in contact with the calcareous rocks, attacks them, forming nitrate of calcium, which, in presence of sulfate of sodium, gives rise to a double decomposition into nitrate of sodium and sulfate of calcium. The fact that iodin is found in greater or less quantity in Chile saltpeter is one of the chief supports of this hypothesis of marine origin, inasmuch as iodin is always found in sea and not in terrestrial plants. Further than this, it must be taken into consideration that these deposits of nitrate of soda contain neither shells nor fossils, nor do they contain any phosphate of lime. The theory, therefore, that they were due to animal origin is scarcely tenable. =13. Boron= occurs chiefly in volcanic regions, but is much more widely distributed in the soil than formerly believed. It is a regular constituent of the ash of many plants,[16] and is, therefore, thought to be a true plant food. It is one of the least abundant of the elements, not occurring in sufficient quantity to find a place in the table showing their relative abundance, which is to follow. Boracic acid is used to some extent as a preservative. =14. Fluorin= does not occur free in nature, but it exists chiefly in combination with calcium, forming fluorspar, and traces of it are found in sea water. It occurs in bone, teeth, blood, and the milk of mammals. It is the only element that does not combine with oxygen, and it can be isolated only with the greatest difficulty. Only very small traces of it are found ordinarily and it is usually not considered in the chemical analysis of soils. Fluorin is found, however, in considerable quantities in certain phosphate deposits. =15. Aluminum= is, probably, next to oxygen and silicon, the most abundant element of the earth’s crust, of which it is estimated to form about one-twelfth. It has never been found, in nature, in the free state, but commonly occurs in combination with silicon and oxygen, in which form it is an abundant constituent of feldspar, mica, kaolin, clay, slate, and many other rocks and minerals. By the weathering of feldspar, mica, and other minerals containing aluminum, kaolin or true clay is formed, which is of the greatest importance in the constitution of the soil. The compounds of aluminum are not so important as plant food as they are as the constituents of the soil, forming a large part of its bulk, and modifying in the most profound degree its physical properties. It is the custom of some authors to use the word clay to designate the fine particles of soil which have in general the same relations to moisture and tilth as the particles of weathered feldspar, etc. In a strict chemical sense, however, the term clay is applied only to the hydrated silicate of alumina formed as indicated above. The fertility of a soil is largely dependent on the quantity of clay which it contains, its relations to moisture and amenability to culture being chiefly conditioned by its clay content. The determination of the percentage of clay in soils is an operation of the highest utility in forming an opinion of the value of a soil on analytical data alone. =16. Calcium= is one of the commonest and most important elements of the earth’s crust, of which it has been estimated to compose about one-sixteenth. It does not occur free in nature, but its most common form is in combination with carbon dioxid, forming the mineral calcite, marble, and the very abundant limestone rocks. In this form it is slightly soluble in water containing carbon dioxid, and hence lime has become a universal component of all soils and is very generally found in natural waters, in which it furnishes the chief ingredient necessary for the formation of the shells and skeletons of the various tribes of mollusca and corals. In combination with sulfuric acid calcium forms the rock gypsum. Lime is not only a necessary plant food, but influences in a marked degree the physical condition of the soil and the progress of nitrification. Many stiff clay soils are rendered porous and pulverulent by an application of lime, and thus made far more productive. On account of its great abundance and low price, it has not commanded the degree of attention from farmers and agricultural chemists which its merits deserve. It forms an essential ingredient of plants and animals, in the latter being collected chiefly in the bones, while in plants it is rather uniformly distributed throughout all the tissues. =17. Magnesium= occurs chiefly in combination with carbon dioxid or with lime and carbon dioxid in the mineral dolomite. It is intimately associated with calcium and a trace of it is nearly always found where lime occurs in any considerable quantity. The bitter taste of sea water and some mineral waters is due to the presence of salts of magnesia. In combination with silica it forms an essential part of such rocks as serpentine, soapstone, and talc. Magnesia is not of much importance as a plant food nor as a fertilizing material. =18. Potassium= combined with silica is an important element in many mineral silicates as, for instance, orthoclase. Granitic rocks usually contain considerable quantities of potassium, and on their decomposition this becomes available for plant food. In the form of chlorid, potassium is found in small quantities in sea water, and as a nitrate it forms the valuable salt known as niter or saltpeter. Potassium, as is the case with phosphorus, is universally distributed in soils, and forms one of the great essential elements of plant food. Under the form of kainite and other minerals large quantities of potassium are used for fertilizing and for the manufacture of pure salts for commercial and pharmaceutical purposes. The ordinary potassium salts are very soluble and for this reason they can not accumulate in large quantities in soils exposed to heavy rain-fall. In the form of carbonate, potassium forms one of the chief ingredients of hard wood ashes, and in this form of combination is especially valuable for fertilizing purposes. Potash salts, being extremely soluble, are likely to be held longest in solution. Some of them, are recovered in animal and vegetable life, but the great mass of potash carried into the sea still remains unaccounted for. The recovery of the waste of potash is chiefly secured by the isolation of sea waters containing large quantities of this salt and their subsequent evaporation. Such isolation of sea waters takes place by means of geologic changes in the level of the land and sea. In the raising of an area above the water level there is almost certain to be an enclosure, of greater or less extent, of the sea water in the form of a lake. This enclosure may be complete or only partial, the enclosed water area being still in communication with the main body of the sea by means of small estuaries. If this body of water be exposed to rapid evaporation, as was doubtless the case in past geologic ages, there will be a continual influx of additional sea water through these estuaries to take the place of that evaporated. The waters may thus become more and more charged with saline constituents. Finally a point is reached in the evaporation when the less soluble of the saline constituents begin to be deposited. In this way the various formations of mineral matter, produced by the drying up of enclosed waters, take place. The most extensive potash deposits known are those in the neighborhood of Stassfurt, in Germany. The following description probably represents the method of formation of these deposits:[17] “The Stassfurt salt and potash deposits had their origin, thousands of years ago, in a sea or ocean, the waters of which gradually receded, leaving near the coast, lakes which still retained communication with the great ocean by means of small channels. In that part of Europe the climate was then tropical, and the waters of these lakes rapidly evaporated but were constantly replenished through these small channels connecting them with the main body. Decade after decade this continued, until by evaporation and crystallization, the various salts present in the sea water were deposited in solid form. The less soluble material, such as sulfate of lime or ‘anhydrite,’ solidified first and formed the lowest stratum. Then came common rock salt with a slowly thickening layer which ultimately reached 3000 feet, and is estimated to have been 13,000 years in formation. This rock salt deposit is interspersed with lamellar deposits of ‘anhydrite,’ which gradually diminish towards the top and are finally replaced by the mineral ‘polyhalite,’ which is composed of sulfate of lime, sulfate of potash, and sulfate of magnesia. The situation in which this polyhalite predominates is called the ‘polyhalite region’ and after it comes the ‘kieserite region,’ in which, between the rock salt strata, kieserite (sulfate of magnesia) is imbedded. Above the kieserite lies the ‘potash region,’ consisting mainly of deposits of carnallite, a mineral compound of muriate of potash and chlorid of magnesia. The carnallite deposit is from 50 to 130 feet thick and yields the most important of the crude potash salts and that from which are manufactured most of the concentrated articles, including muriate of potash.” “Overlying this region is a layer of impervious clay which acts as a water-tight roof to protect and preserve the very soluble potash and magnesia salts, which, had it not been for the very protection of this overlying stratum, would have been long ages ago washed away and lost by the action of the water percolating from above. Above this clay roof is a stratum, of varying thickness of anhydrite, and still above this a second salt deposit, probably formed under more recent climatic and atmospheric influences or possibly by chemical changes in dissolving and subsequent precipitation. This salt deposit contains ninety-eight per cent (often more) of pure salt, a degree of purity rarely elsewhere found. Finally, above this are strata of gypsum, tenacious clay, sand, and limestone, which crop out at the surface.” “The perpendicular distance from the lowest to the upper surface of the Stassfurt salt deposits is about 5000 feet (a little less than a mile), while the horizontal extent of the bed is from the Harz Mountains to the Elbe River in one direction, and from the city of Madgeburg to the town of Bernburg in the other.” According to Fuchs and DeLauny[18] the saline formation near Stassfurt is situated at the bottom of a vast triassic deposit surrounding Madgeburg. The quantity of sea water which was evaporated to produce saline deposits of more than 500 meters in thickness must have been enormous and the rate of evaporation great. It appears that a temperature of 100° would have been quite necessary, acting for a long time, to produce this result. These authors therefore admit that all the theories so far advanced to explain the magnitude of these deposits are attended with certain difficulties. What, for instance, could have caused a temperature of 100°? The most reasonable source of this high temperature must be sought for in the violent chemical action produced by the double decompositions of such vast quantities of salts of different kinds. There may also have been at the bottom of this basin some subterranean heat such as is found in certain localities where boric acid is deposited. Whatever be the explanation of the source of the heat it will be admitted that at the end of the permian period there was thrown up to the northeast of the present saline deposits a ridge extending from Helgoland to Westphalia. This dam established throughout the whole of North Germany saline lagoons in which evaporation was at once established, and these lagoons were constantly fed from the sea. There was then deposited by evaporation, first of all a layer of gypsum and afterwards rock salt, covering with few exceptions the whole of the area of North Germany. But around Stassfurt there occurred at this time geologic displacements, the saline basin was permanently closed and then by continued evaporation the more deliquescent salts, such as polyhalite, kieserite, and carnallite, were deposited. These theories account with sufficient ease for the deposition of the saline masses, but do not explain why in those days the sea water was so rich in potash and why potash is not found in other localities where vast quantities of gypsum and common salt have been deposited. It may be that the rocks composing the shores of these lagoons were exceptionally rich in potash and that this salt was, therefore, in a certain degree, a local contribution to the products of concentration. =19. Sodium= is never found free in nature, but its most common form is in combination with chlorin as common salt, an important ingredient of sea water. Combined with silica sodium is an important element in many silicates. Sodium, although closely related to potassium chemically, cannot in any case be substituted therefor in plant nutrition. In combination with nitrogen it forms soda or Chile saltpeter which is a valuable fertilizer on account of its content of nitric acid. =20. Iron= is the most abundant of the heavy metals, and occurs in nature both free and combined with other elements. In the free state it is found only to a limited extent in basaltic rocks and meteorites, but in combination with oxygen it is one of the most widely diffused of metals, and forms the coloring matter of a large number of rocks and minerals. In this form, too, it exists as the valuable ores of iron known as magnetite and hematite. In combination with sulfur it forms the mineral pyrite, FeS₂. The yellow and red colors of soils are due chiefly to iron oxids. It is an important plant food, although not taken up in any great quantity by the tissues of plants. =21. Manganese=, next to iron, is the most abundant of the heavy metals. It occurs in nature only in combination with oxygen, in which form it is associated in minute quantities with iron in igneous rocks or in the forms known mineralogically as pyrolusite, psilomelane and wad. As the peroxid of manganese it occurs in concretionary forms scattered abundantly over the bottom of the deep sea. It is found in the ash of some plants but is not believed to be an essential to plant growth. =22. Barium= occurs in nature combined with sulfuric acid, forming the mineral barite, or heavy spar, or with carbon dioxid forming the mineral witherite. It is of small importance from an agricultural standpoint. =23. Relative Abundance of the More Important Chemical Elements.=—It will be of interest to the agricultural analyst to know as nearly as possible the relative abundance of the more important chemical elements. This subject has been carefully studied by Prof. F. W. Clarke in a paper read before the Philosophical Society of Washington.[19] The materials considered in these calculations are the atmosphere, the water, and the solid crust of the earth to the depth of ten miles below the sea level. Of these materials the relative quantities of the three constituents named are as follows: Per cent. Atmosphere 0.03 Water 7.08 Solid crust of the earth to the depth of ten miles 92.89 According to these calculations the relative abundance of the important elements composing the atmosphere, the water of the ocean and the solid crust of the earth to the depth given is as follows: Solid crust, Ocean, seven per Mean, including ninety-three per cent. air. cent. Oxygen 47.29 per cent. 85.79 per cent. 49.98 per cent. Silicon 27.21 „ „ „ „ 25.30 „ „ Aluminum 7.81 „ „ „ „ 7.26 „ „ Iron 5.46 „ „ „ „ 5.08 „ „ Calcium 3.77 „ „ 0.05 „ „ 3.51 „ „ Magnesium 2.68 „ „ 0.14 „ „ 2.50 „ „ Sodium 2.36 „ „ 1.14 „ „ 2.28 „ „ Potassium 2.40 „ „ 0.04 „ „ 2.23 „ „ Hydrogen 0.21 „ „ 10.67 „ „ 0.94 „ „ Titanium 0.33 „ „ „ „ 0.30 „ „ Carbon 0.22 „ „ 0.002 „ „ 0.21 „ „ Chlorin 0.01 „ „ 2.07 } „ „ 0.15 „ „ Bromin „ „ 0.008} „ „ „ „ Phosphorus 0.10 „ „ „ „ 0.09 „ „ Manganese 0.08 „ „ „ „ 0.07 „ „ Sulfur 0.03+ „ „ 0.09 „ „ 0.04+ „ „ Barium 0.03 „ „ „ „ 0.03 „ „ Nitrogen „ „ „ „ 0.02 „ „ Chromium 0.01 „ „ „ „ 0.01 „ „ —————— ——————— —————— 100.00 „ „ 100.000 „ „ 100.00 „ „ =24. Fluorin= is not mentioned in this table but it is stated that its probable percentage is 0.02 to 0.03 making it thus slightly more abundant than nitrogen. One of the chief points of interest in connection with this table is that the nitrogen which is regarded by most persons as one of the most abundant of the elements is almost the least abundant of those mentioned. THE MINERALS OCCURRING IN ROCKS. =25. The Soil=, as before stated, being comprised almost exclusively of decayed rocks, its characteristics would naturally be determined by the character of the minerals contained in the rocks. A rock may be composed of a single mineral or an aggregation of several minerals. According to the authority of the National Museum[20] it may occur, either in the form of stratified beds, eruptive masses, sheets or dikes, or as veins and other chemical deposits of comparatively little importance as regards size and extent. The mineral composition of rocks is greatly simplified by the wide range of conditions under which the commonest minerals can be formed. Thus quartz, feldspar, mica, the minerals of the hornblende, or pyroxene group, can be formed from a mass cooling from a state of fusion; they may be crystallized from solution, or be formed from volatilized products. They are therefore the commonest of minerals and are rarely excluded from rocks of any class, since there is no process of rock formation which determines their absence. Most of the common minerals, like the feldspars, micas, hornblendes, pyroxenes, and the alkaline carbonates possess the capacity of adapting themselves to a very considerable range of compositions. In the feldspars, for example, lime, soda, or potash may replace one another almost indefinitely, and it is now commonly assumed that true species do not exist, but all are but isomorphous admixtures passing into one another by all gradations, and the names albite, oligoclase, anorthite, etc., are to be used only as indicating convenient stopping and starting points in the series. Hornblende or pyroxene, further, may be pure silicate of lime and magnesia, or iron and manganese may partially replace these substances. Lime carbonate may be pure, or magnesia may replace the lime in any proportion. These illustrations are sufficient to show the reason for the great simplicity of rock masses as regards their chief mineral constituents. Whatever may be the conditions of the origin of a rock mass, the probabilities are that it will be formed essentially of one or more of a half a dozen minerals in some of their varieties. But however great the adaptability of these few minerals may be they are, nevertheless, subject to very definite laws of chemical equivalence. There are elements which they cannot take into their composition, and there are circumstances which retard their formation while other minerals may be crystallizing. In a mass of rock of more or less accidental composition formed under these widely varying conditions it may, therefore, be expected that other minerals will form, in considerable numbers, but minute quantities. It is customary to speak of those minerals which form the chief ingredients of any rock, and which may be regarded as characteristic of any particular variety, as the essential constituents, while those which occur in but small quantities, and whose presence or absence does not fundamentally affect its character, are called accessory constituents. The accessory mineral which predominates, and which is, as a rule, present in such quantities as to be recognizable by the unaided eye, is the characterizing accessory. Thus a biotite granite is a stone composed of the essential minerals quartz and potash feldspar, but in which the accessory mineral biotite occurs in such quantities as to give a definite character to the rock. =26. Classification Of Minerals.=—The minerals of rocks may also be conveniently divided into two groups, according as they are products of the first consolidation of the mass or of subsequent changes. This is the system here adopted. We thus have: (1) The original or primary constituents, those which formed upon its first consolidation. All the essential constituents are original, but on the other hand all the original constituents are not essential. Thus, in granite, quartz and orthoclase are both original and essential, while beryl and zircon or apatite, though original, are not essential. (2) The secondary constituents are those which result from changes in a rock subsequent to its first consolidation, changes which are due in great part to the chemical action of percolating water. Such are the calcite, chalcedony, quartz, and zeolite deposits which form in the druses and amygdaloidal cavities, of traps and other rocks. Below is given a list of the more common, original and secondary minerals occurring in rocks. It will be observed that the same mineral may, in certain cases, occur in both original and secondary forms. The tables following were prepared by Dr. George P. Merrill. ORIGINAL MINERALS. 1. Quartz, SiO₂. 2. The Feldspars: 2a. Orthoclase. Anhydrous silicate of alumina with varying amounts of lime, potash, or soda and rarely barium. 2b. Microcline. „ 2c. Albite. „ 2d. Oligoclase. „ 2e. Andesite. „ 2f. Labradorite. „ 2g. Bytownite. „ 2h. Anorthite. „ 3. The Amphiboles: 3a. Hornblende. Anhydrous silicates of lime and magnesia with iron and alumina in the dark varieties. 3b. Tremolite. „ 3c. Actinolite. „ 3d. Arfvedsonite. „ 3e. Glaucophane. „ 3f. Smaragdite. „ 4. The Monoclinic Pyroxenes: 4a. Malacolite. Anhydrous silicates of magnesia and lime with alumina and iron in the dark varieties. 4b. Diallage. „ 4c. Augite. „ 4d. Acmite. „ 4c. Aegerite. „ 5. The Rhombic Pyroxenes: 5a. Enstatite (bronzite). Silicates of magnesia and iron. 5b. Hypersthene. „ 6. The Micas: 6a. Muscovite. Anhydrous silicates of alumina with potash, soda, and iron. 6b. Biotite. „ 6c. Phlogopite. „ 7. Calcite, 8. Dolomite. 9. Gypsum. 10. Olivine. 11. Beryl. 12. Tourmaline. 13. Garnet, variable common form. 14. Vesuvianite. 15. Epidote. 16. Zoisite. 17. Allanite. 18. Andalusite. 19. Staurolite. 20. Fibrolite. 21. Cyanite. 22. Scapolite. 23. Apatite. 24. Elaeolite and Nepheline. 25. Leucite. 26. Cancrinite. 27. The Sodalite Group: 27a. Sodalite. 27b. Haüyn (noseau). 28. Zircon. 29. Chondrodite. 30. Cordierite. 31. Topaz. 32. Corundum. 33. Titanite (sphene). 34. Rutile. 35. Menaccanite. 36. Magnetite. 37. Hematite. 38. Chromite. 39. The Spinels: 39a. Pleonast. 39b. Picotite. 40. Pyrolusite. 41. Halite (common salt). 42. Fluorite. 43. The Elements: 43a. Graphite. 43b. Carbon. 43c. Iron. 43d. Copper. 44. The Metallic Sulfids: 44a. Galena. 44b. Sphalerite. 44c. Pyrrhotite. 44d. Marcasite. 44e. Pyrite. 44f. Chalcopyrite. 44g. Arsenopyrite. SECONDARY MINERALS. 1. Quartz: 1a. Chalcedony. 1b. Opal. 1c. Tridymite. 2. Albite. 3. The Amphibole Group: 3a. Hornblende. 3b. Tremolite. 3c. Actinolite. 3d. Uralite. 4. Muscovite (sericite). 5. The Chlorites: 5a. Jefferisite. 5b. Ripidolite. 5c. Penninite. 5d. Prochlorite. 6. Calcite (and aragonite). 7. Wollastonite. 8. Scapolite. 9. Garnet. 10. Epidote. 11. Zoisite. 12. Serpentine. 13. Talc. 14. Kaolin. 15. The Zeolites: 15a. Pectolite. 15b. Laumontite. 15c. Prehnite. 15d. Thomsonite. 15e. Natrolite. 15f. Analcite. 15g. Datolite. 15h. Chabazite. 15i. Stilbite, 15k. Heulandite. 15l. Harmotome. 16. Magnetite. 17. Hematite. 18. Limonite. 19. Siderite. 20. Pyrite. 21. Pyrrhotite. ROCKS AND ROCK DECAY. =27. Types Of Rocks.=—Rocks may be divided in reference to their structure into four types: First, crystalline; second, vitreous; third, colloidal; fourth, fragmental. Of these classes there may be selected, as types of the first order, granite and crystalline limestone. The second class is typically represented by obsidian. Rocks of this kind are confined to a volcanic origin. The third class of rocks is completely amorphous in its structure and is less common than the others. It is found only in rocks of chemical origin. Types of this class are the siliceous sinters, opals, flint nodules, and many serpentines. Of the fourth class of rocks, sandstone is typical, being comprised wholly of fragments of rocks pre-existing. The particles may be held together either by cohesion or by a cement composed of silica, iron oxids, carbonate of lime or clayey matter. =28. The Microscopical Structure of Rocks.=—A great deal more light is thrown upon the nature of rock materials by microscopical study than by their study in bulk. The requisites for a microscopical study of rock are that the material should be cut into extremely thin laminae with parallel sides and polished so as to transmit the light freely. The study of the crystalline structure of the material is then conducted by means of a microscope furnished with polarizing and analyzing appliances. The light before passing through the mineral film is polarized by a Nicol prism. After passing through the film it is analyzed by a second Nicol prism. In this way the crystalline structure of the rock as affecting polarized light is distinctly brought out. The thickness of the films examined should be from ¹⁄₅₀₀ to ¹⁄₆₀₀ of an inch. FIG. 1. Microstructure of granite. FIG. 2. Microstructure of micropegmatite. FIG. 3. Microstructure of quartz porphyry. FIG. 4. Microstructure of porphyritic obsidian. FIG. 5. Microstructure of trachyte. FIG. 6. Microstructure of serpentine. ] The method of rock study by thin microscopic sections is one of comparatively recent origin. It is scarcely more than a dozen years since the process was fairly adopted by mineralogists. The value of the method is based upon the fact that every crystalline mineral has certain definite optical properties. Therefore, when a crystalline mineral is distorted or misshapen so as to be incapable of identification by the ordinary method, it can be at once identified by its optical examination in the manner just described. In this way not only can one mineral be distinguished from another, but the crystalline system to which it belongs can be accurately pointed out. The value of the method is well summed up by Merrill,[21] who says that it is not merely an aid in determining the mineralogical composition of a rock, but also, which is often much more important, its structure and the various changes which have taken place in it since its first consolidation. Rocks are not the definite and unchangeable mineral compounds they were once considered, but are rather ever varying aggregates of minerals which even in themselves undergo structural and chemical changes almost without number. Another valuable result of such a study is illustrated by the discovery that the structural features of a rock are not dependent upon its chemical composition or geologic age, but upon the conditions under which it cooled from the molten magma. Portions of the same rock may vary all the way from a wholly crystalline to a pure vitreous form. Some typical microstructures of crystalline rocks are shown in the accompanying figures 1–6.[22] Although this method of study has thus far been confined mainly to crystalline rocks, its efficiency is by no means limited to them. The fragmental rocks and their decomposed débris to which the name soil is given are equally worthy of study by this method. Indeed, the full value of a chemical analysis of any rock or soil can not be ascertained unless such an analysis is accompanied by a microscopic examination. It is desirable to know not merely what there is in any soil, but in what form these compounds exist. To this latter question the chemical analysis as ordinarily made will give no clew. In Germany a beginning has been made in this line of work, and American scientists are beginning to realize its importance. An outline of this method of analysis will be given in the proper place. =29. Specific Gravity.=—Much information in regard to the properties of a rock, or mineral constituent thereof, may be derived from its specific gravity. The internal structure of a rock may have much to do with its apparent specific gravity. As an instance of this, it may be stated that an obsidian pumice will float upon water, buoyed up by the air contained in its vesicles, while a compact obsidian of the same composition will sink immediately. A careful discrimination must, therefore, be made between apparent and true specific gravity. In general it may be said that crystalline rocks have a higher specific gravity than those of a vitreous nature. The specific gravity is, therefore, largely dependent upon chemical and crystallographic properties; for instance, among siliceous rocks those which contain the largest amount of silica are the lightest, while those with a comparatively small amount, but rich in iron, lime, and magnesia, are heaviest. =30. Chemical Composition of Rocks.=—Rocks are often classified with respect to the chief mineral constituent which they contain. Rocks which are composed largely of lime are termed calcareous; of silica, siliceous; of iron, ferruginous; and of clay, argillaceous. In respect of eruptive rocks, it is customary to speak of those which show above sixty per cent of silica as acidic, while those containing less than fifty per cent of silica and a correspondingly larger amount of iron, lime, and magnesia, are spoken of as basic. Illustrations of the classification of rocks on the above principles are given below.[23] STRATIFIED ROCKS. ──────────────────────────┬──────────────┬───────────────────────────── Kind. │ Specific │ Composition. │ Gravity. │ ──────────────────────────┼──────────────┼───────────────────────────── Calcareous: │ │ Compact limestone │ 2.6 to 2.8 │ Carbonate of lime. Crystalline limestone │ „ │ „ │ │ Compact dolomite │ 2.8 to 2.95 │ Carbonate of lime and │ │ magnesia. Crystalline dolomite │ „ │ „ │ │ Siliceous: │ │ Gneiss │ 2.6 to 2.7 │ Same as granite. Siliceous sandstone │ 2.6 │ Mainly silica. Schist │ 2.6 to 2.8 │ 60 to 80 per cent silica. │ │ Argillaceous: │ │ Clay slate (argillite) │ 2.5 │ Mainly silicate of alumina. ──────────────────────────┼──────────────┼───────────────────────────── │ │ ERUPTIVE ROCKS. ──────────────────────────┬──────────────┬───────────────────────────── │ Specific │ Per cent silica. │ Gravity. │ ──────────────────────────┼──────────────┼───────────────────────────── Acidic Group: │ │ Granite │ 2.58 to 2.73 │ 77.65 to 62.90 Liparite │ 2.53 to 2.70 │ 76.06 to 67.61 Obsidian │ 2.26 to 2.41 │ 82.80 to 71.19 Obsidian pumice │ Floats on │ 82.80 to 71.19 │ water. │ │ │ Intermediate Group: │ │ Syenite │ 2.73 to 2.86 │ 72.20 to 54.65 Trachyte │ 2.70 to 2.80 │ 64.00 to 60.00 Hyalotrachyte │ 2.4 to 2.5 │ 64.00 to 60.00 Andesite │ 2.54 to 2.79 │ 66.75 to 54.73 │ │ Basic Group: │ │ Diabase │ 2.66 to 2.88 │ 50.00 to 48.00 Basalt │ 2.90 to 3.10 │ 50.59 to 40.74 Peridotite │ 3.22 to 3.29 │ 42.65 to 33.73 Peridotite (iron rich) │ 3.86 │ 23.00 Peridotite (meteorite) │ 3.51 │ 37.70 ──────────────────────────┴──────────────┴───────────────────────────── =31. Color Of Rocks.=—The color of rocks is determined chiefly by the oxids of metals which they contain and the degree of oxidation of the mineral in each particular case. There are, however, many colors of rocks which seem to depend not upon any particular mineral ingredient which they contain, but upon some particular crystalline structure or physical condition. The chief coloring matters in minerals are those which form colored bases such as iron, manganese, chromium, etc. The yellow, brown, and red colors, common to fragmental rocks, are due almost wholly to free oxids of iron. The gray, green, dull brown, and even black colors of crystalline rocks are due to the presence of free iron oxids or to the prevalence of silicate mineral rich in iron, as augite, hornblende, or black mica. Rarely copper and other metallic oxids than those of iron are present in sufficient abundance to impart their characteristic hues. As a rule, a white or light-gray color denotes an absence of an appreciable amount of iron in any of its forms. The bluish and black colors of many rocks, particularly the limestones and slates, are due to the presence of carbonaceous matter. In still other cases, and particularly the feldspar-bearing rocks, the color may be due in part to the physical condition of the feldspar. Inasmuch as the color of rocks is due so largely to metallic oxids, it is easy to see that they may undergo changes when exposed to weathering, or the degree of oxidation may change, and either, together with changes in the physical structure of the rock, may cause a distinct change in color. Luster is often considered in connection with color, and is due almost exclusively to physical conditions. =32. Kinds of Rocks.=—The rocks which form any essential part of the earth’s crust are grouped under four main heads, the distinction being based upon their origin and structure.[24] Each of the main divisions may be subdivided into groups or families, the distinction being based mainly upon chemical composition, structure, and mode of occurrence. The four chief families are: First, aqueous rocks, formed mainly through the agency of water as chemical precipitates or as sedimentary beds. Second, aeolian rocks formed from wind-drifted materials. Third, metamorphic rocks, changed from their original condition through dynamic or chemical agencies, and which may have been partly of aqueous and partly of igneous origin. Fourth, igneous or eruptive rocks, which have been brought up from below in a molten condition, and which owe their present structural peculiarities to variations in composition and conditions of solidification. =33. Aqueous Rocks.=—Aqueous rocks may be divided into the following general classes: First, rocks formed as chemical precipitates. Second, rocks formed as sedimentary deposits and fragmental in structure. The second class may again be subdivided into rocks formed by mechanical agencies and mainly of inorganic materials; and second, rocks composed mainly of the débris of plant and animal life. In regard to the first form of aqueous rocks, namely, those formed as chemical precipitates, it may be said that while their quantity is not large they are yet of considerable importance from an agricultural point of view. They embrace those substances which, having once been in a condition of vapor or aqueous solution, have been deposited or precipitated, either by cooling or by the evaporation of the liquor holding them in solution, or by coming in contact with chemical substances capable of precipitating them. The influence of water as a solvent is perhaps not fully appreciated. Its solvent influence will be noted particularly under the head of weathering or decay of rocks. Its importance, however, in producing stratified rocks has been very great. Water, especially when under great pressure and at a high temperature, has the power of dissolving many minerals. This power is often greatly increased by the mineral matter previously in solution in the water or by the gases which it may contain. As an illustration of the latter property, the solvent action of water charged with carbon dioxid on limestone may be cited. When mineral matters have been dissolved by the water in the ways mentioned and carried with the water beyond the condition where the solution has taken place, new conditions are found favorable to the precipitation of the dissolved matters. The water, which before may have been very hot, may reach a place where it cools, and being a supersaturated solution, the excess of the material is thrown down as the water cools. On the other hand, if the solution be due to the presence of carbon dioxid and the water reach a place where it is exposed to the air or where the pressure under which the abundance of the gas has been due is diminished, the carbon dioxid will escape and the mineral matters which have been dissolved thereby will be precipitated. The incrustations which often appear round the mouth of springs and the occurrence of stalagmites and stalactites in caves are illustrations of this action. In respect of the formation of rocks as precipitates from a state of vapor we have scarcely any illustrations excepting in volcanic regions. Rocky materials with which we are generally acquainted are practically non-volatile at the highest temperature which can be secured on the earth’s surface, but it is possible that in the interior of the earth the temperature may be so high as to maintain many substances in a state of vapor. They may, in this case, become disassociated so that the compounds or elements exist distinctly in a vaporous condition. Such a vapor transported to regions of diminished temperature would first of all on cooling permit a union of the chemical elements forming new compounds less volatile, which, of course, would be at once precipitated. The rocks and minerals formed in this way which are of some agricultural importance may be classified as follows: Oxids, carbonates, silicates, sulfur, sulfids, sulfates, phosphates, chlorids, and hydrocarbon compounds, the most important from an agricultural point of view being the phosphates. The second group of rocks, namely those formed as sedimentary deposits, differ from those just described in that they are comprised mainly of fragmental materials derived from the breaking down of pre-existing rocks. The formation of fragmental rocks includes, therefore, the same processes as are active in the formation of arable soil. They are deposited from water, and are as a rule distinctly stratified. Through the action of pressure and the heat thereby generated, or simply through the chemical action of percolating solutions, such rocks pass over into the crystalline sedimentary forms known as metamorphic. All metamorphic rocks, however, are not of a sedimentary origin. For instance, by pressure, heat, and the chemical changes thereby induced, granite may be changed into gneiss and the latter would then be a metamorphic rock. This group of sedimentary rocks and of sedimentary material, either unchanged or metamorphosed, is of vast extent and includes materials of widely varying chemical and mineralogical nature. They form by far the greater portion of the present surface of the earth, even the mountain ranges being composed mainly of this sedimentary material. Indeed, in the whole of this country there is only a comparatively very small extent of igneous or irruptive rocks. They are of great importance from a purely scientific, as well as agricultural standpoint, since they contain the fossil records of past geologic ages. From them it is possible to study the variations in climate, the meteorological conditions in circumstances and periods far remote, and thus form some idea of the process by which the crust of the earth has been modified by natural forces from its original form to the present time. The sedimentary rocks may be divided, with sufficient accuracy for our purposes, into two great classes: First, rocks formed by mechanical agencies and mainly of inorganic materials. These are subdivided again as follows: (a) The arenaceous group. (b) The argillaceous group. (c) The volcanic group. The second class of sedimentary rocks is formed largely, or in part at least, by mechanical agencies, but is comprised chiefly of the débris of plant and animal life. It may be subdivided as follows: (a) The siliceous group, such as infusorial earth. (b) The calcareous group, fossiliferous formations, limestone, etc. (c) The carbonaceous group, such as peat, lignite, coals, etc. The different classes of rock described above are distinguished by special qualities represented largely by the name. The first division, the arenaceous group, is composed mainly of the siliceous or coarsely granular materials derived from the disintegration of older crystalline rocks, which have been rearranged in beds of varying thickness through the mechanical agency of water. They are, in short, consolidated or unconsolidated beds of sand and gravel. In composition and texture they vary almost indefinitely. Many of them having suffered little during the process of disintegration and transportation are composed essentially of the same materials as the rocks from which they were derived. The sandstones, which are the type of these rocks, vary greatly in structure as well as in composition, in some the grains being rounded while in others they are sharply angular. The microscopic structure of sandstone is shown in figure 7.[24] The material by which the individual grains of a sandstone are bound together is usually the material of some of the other classes. The calcareous, ferruginous, and siliceous cements being the chief ones. This cementing substance is deposited among the granules forming the sandstone by percolating water. The colors of sandstone are dependent usually upon iron oxids. Especially is this true of the red, brown, and yellow colors. In some of the light grey varieties, the color is that of the minerals comprising the stone. Some of the darker colored sandstones contain organic matter. FIG. 7. Microscopic Structure of Sandstone. ] The rocks of the argillaceous group are composed essentially of a hydrous silicate of alumina, which is the basis of common clay, and varying amounts of free silica, oxids of iron and manganese, carbonates of lime and magnesia, and small quantities of organic matter. They may have originated _in situ_ from the decomposition of feldspars or as deposits of fine mud or silt at the bottom of large bodies of water. The older formations of these rocks are known as shales, argillites, and slates and the fissile structure which enables this to be split into thin sheets is probably due to the conditions under which they have been formed and not to any properties of the clays themselves. One of the purest forms of this rock is kaolin, which is almost a pure hydrous silicate of alumina formed from the decomposition of feldspathic rocks from which the alkalies, iron oxids and other soluble constituents have been removed by water. Under the volcanic group are included the materials ejected from volcanic vents in a more or less finely comminuted condition and which through the drifting power of atmospheric currents may be scattered over many miles of territory. Various names are applied to such products, names dependent in large part upon their state of subdivision. Volcanic dust and sand, or ashes, includes the finer dust-like or sand-like materials, and lapilli, or rapilli the coarser. The general name tuff includes the more or less compacted and stratified beds of this material, while trass, peperino, and pozzuolano are local varietal names given to similar materials occurring in European volcanic regions. The second division, namely sedimentary rocks composed of the débris of plant and animal life includes many forms of great agricultural importance. The first subdivision of this group is the infusorial or diatomaceous earth. It forms a fine white or yellowish pulverulent rock composed mainly of minute shells, or tests of diatoms, and is often so soft and pliable as to crumble readily between the thumb and fingers. According to Whitney the beds are of comparatively limited extent and for this reason are of little agricultural value, although the weathering of this diatomaceous material gives rise to a light yellow clay forming very fertile agricultural lands. The second subdivision of this group includes the rocks of a calcareous nature derived from animal life; that is to say, what are properly called limestones. They vary in color, structure, and texture almost indefinitely, and include all possible grades of materials from those which can be used only as a flux, or for lime burning, through ordinary building materials to the finest marbles. These rocks are world-wide in their distribution and limited to no one particular geologic horizon, but are found in stratified beds among rocks of all ages from the most ancient to the most recent. Owing to the fact that their chief constituent, carbonate of lime, is soluble in ordinary meteoric waters, the rocks have undergone extensive decomposition, their lime being removed, while their less soluble constituents or impurities remain to form soil. A single ton of residual soil represents not infrequently a loss of 100 tons of original rock matter. As this mass of lime carbonate is removed by solution the residual soil settles, and as the limestone rocks are more soluble than the adjacent rock formations limestone formations usually form valley lands with ridges on either side. Caves are frequently found in such formations. Furthermore, as the lime is almost all in the form of the easily soluble lime carbonate it can be very completely removed and the fertile “limestone soils” are often very deficient in lime and respond readily to an application of burnt lime, which, not infrequently, is quarried from the same field. From an agricultural standpoint this group is of very great interest and importance. The third subdivision of this group, namely, that of vegetable origin, includes peat, lignite, coals, etc. Rocks of this group are made up of more or less fragmental remains of plants. In many of them, as the peats and lignites, the traces of plant structure are still apparent. In others, as the anthracite coals, these structures have been wholly obliterated by metamorphisms. Plants when decomposing on the surface of the ground give off their carbon to the atmosphere in the shape of carbon dioxid gas leaving only the strictly inorganic or mineral matter behind. When, however, they are protected from the oxidizing influence of the air, by water or by other plant growth, decomposition is greatly retarded, and a large portion of the carbonaceous and volatile matters is retained, and by this means together with pressure from the overlying mass, the material becomes slowly converted into coal. When this process goes on near the surface of the earth, and without much pressure, peat or muck is the product. The fourth subdivision of this group, the phosphatic, forms a class of rocks limited in extent but of the greatest economic importance. Guano, coprolites, and phosphatic rocks (the phosphorites) come under this head. =34. Aeolian Rocks.=—This class of rocks is of less importance than the others, either geologically or agriculturally. It is formed from materials drifted by the winds and this material has various degrees of compactness. Usually the components of these drifts form rocks or deposits of a friable texture and of a fragmental nature. The very extensive deposits of loess in China, forming their most fertile lands, are admitted now to have been formed in this way, but it is now generally admitted that similar deposits in this country are of subaqueous origin. Chief among these rocks, are the volcanic ashes which are often carried to a long distance by the wind before they are deposited and consolidated into rock masses. Many loose soils may be carried to great distances by the wind, the deposits forming new aggregates. This is particularly the case in arid regions. =35. Metamorphic Rocks.=—This class of rocks includes all sedimentary or eruptive rocks, which, after their deposition and agglomeration, have been changed in their nature through the action of heat, pressure, or by chemical means. Sometimes these changes are so complete that no indication of the character of the original rocks remains. At other times the changes may be found in all the stages of progress, so that they can be traced from the original fragmental or irruptive to the completely metamorphosed deposit. This is especially true of rocks containing large quantities of lime. In those containing silica, the changes are less readily traced. FIG. 8. MICROSTRUCTURE OF CRYSTALLINE LIMESTONE. (West Rutland, Vermont.) ] The metamorphic rocks may be divided into two subclasses, namely, stratified or bedded, and foliated or schistose. The rocks of the first class are represented by the crystalline limestones and dolomites. The microstructure of a crystalline limestone is shown in Fig. 8.[25] When lime and magnesia occur together in combination with carbon dioxid, the substance is known as dolomite. The chemical nature of these rocks and their soil-forming properties are the same as those of the ordinary, non-metamorphosed limestones and dolomites to which reference has already been made. The subject need not, therefore, be further dwelt upon here. FIG. 9. MICROSTRUCTURE OF GNEISS. (West Andover, Massachusetts.) At _a a_ are shown plagioclase crystals broken and rounded by the sheering force producing the foliation. ] The second variety of metamorphic rocks is represented by the gneisses and crystalline schists. Gneiss has essentially the same composition as granite and can frequently hardly be distinguished from it, except by a microscopic study of its sections, and even thus it is sometimes difficult to determine. Frequently a number of new minerals is formed in the metamorphic changes. The microstructure of a gneiss is shown in Fig. 9.[26] The schists include an extremely variable class of rocks, of which quartz is the prevailing constituent, and which, as a rule, are deficient in potash and other important ingredients. =36. Rocks Formed Through Igneous Agencies, or Eruptive Rocks.=—This group includes all those rocks, which, having been at some time in a state of igneous fusion, have been solidified into their present form by a process of cooling. It may be stated, as a general principle, that the greater the pressure under which a rock solidifies and the slower and more gradual the cooling the more perfect will be found the crystalline structure. Hence, it follows that the older and more deep-seated rocks which are forced up in the form of dikes, bosses, or intrusive sheets, into the overlying masses, and which have become exposed only through erosion and removal of the overlying rocks, are the more highly crystalline. The eruptive rocks are divided into two main groups, _viz._: (a) Intrusive or plutonic rocks, and (b) Effusive or volcanic rocks. Among the more important of the first division of the plutonic form, from an agricultural point of view, are the granites. The essential constituents of granite are quartz, potash feldspar, and plagioclase. One or more minerals of the mica, amphibole or pyroxene groups are also commonly present, and in microscopic proportions apatite and particles of magnetic iron. The more valuable constituents, from an agricultural standpoint, are the minerals potash feldspar, and apatite, which furnish by their decomposition the essential potash and phosphoric acid. In addition to the granites, which have already been mentioned, the group includes the syenites, the nepheline syenites, the diorites, the gabbros, the diabases, the theralites, the peridotites, and the pyroxenites. The second group, the effusive or volcanic rocks, includes those igneous rocks, which, like the first group, have been forced up through the overlying rocks, but which were brought to the surface, flowing out as lavas. These, therefore, represent, in many cases, only the upper or surface portions of the first group, differing from them structurally, because they have cooled under little pressure more rapidly, and hence are not so distinctly crystalline. These comprise the following groups: (a) Quartz porphyries. (b) Liparites. (c) Quartz-free porphyries. (d) Trachytes. (e) Phonolites. (f) Porphyrites. (g) Andesites. (h) Melaphyrs and augite porphyrites. (i) Basalts. (j) Tephrites and Basanites. (k) Picrite porphyrites. (l) Limburgites and augitites. (m) Leucite rocks. (n) Nepheline rocks. (o) Melilite rocks. It is, in most cases, impossible to state which of the above classes is of most importance from an agricultural standpoint, since, in the process of soil formation, both chemical and physical processes are involved, whereby the character of the resultant soil is so modified as to but remotely resemble its parent rock. In most soils, the prevailing constituent is but the least soluble one of the rock mass from which it was derived. Thus a limestone soil may contain upwards of ninety per cent of silica and alumina, while the original limestone itself may not have carried more than one or two per cent of these substances. Of course, if a rock mass contains none of the constituents essential to plant growth, its resultant soil must by itself alone be quite barren. It does not absolutely follow, however, that those rocks containing the highest percentages of valuable constituents will yield the most fertile soils, since much depends on the manner in which they have been formed, the amount of leaching, etc., they may have undergone. Nevertheless, the study of the composition of the rocks in their relation to soils, is an extremely interesting and by no means unimportant one. A comparative table of rock compositions is here given. It will be observed that there is a considerable range of variation even among rocks of the same class, a fact due to the varying abundance of their mineral constituents. The figures given are not those of actual analyses on any one particular rock, but are selected from a number of comparatively typical cases; and, it is thought, fairly well represent the composition of the class of rocks indicated. COMPOSITION OF ROCKS.—THE FIGURES INDICATE PARTS PER HUNDRED. ──────────────────────┬────────┬────────────┬────────────┬──────── │ SiO₂. │ Al₂O₃. │ Fe₂O₃. │ MgO. │ │ │ FeO. │ ──────────────────────┼────────┼────────────┼────────────┼──────── Granite │ │ │ │ Quartz poryhyries} │ 63–78 │ 10–15 │ 2–3 │0.3–0.5 Liparite │ │ │ │ │ │ │ │ Syenite │ │ │ │ Orthoclase porphyries}│ 55–73 │ 12–16 │ 5–7 │ 2–6 Trachyte │ │ │ │ │ │ │ │ Nepheline syenites} │ 54–56 │ 16–22 │ 4–6 │0.4–0.88 Phonolites │ │ │ │ │ │ │ │ Diorites │ │ │ │ Porphyrites} │ 52–65 │ 16–20 │ 7–10 │ 5–7 Andesites │ │ │ │ │ │ │ │ Gabbros │ │ │ │ Norites} │ 48–55 │ 12–20 │ 8–15 │ 2–7 Melaphyrs │ │ │ │ │ │ │ │ Theralites │ │ │ │ Tephrites} │ 43–47 │ 15–23 │ 9–18 │ 1–6 Basanites │ │ │ │ │ │ │ │ Peridotites │ │ │ │ Picrite porphyrites} │ 23–43 │ 1–10 │ 10–15 │ 15–45 Limburgites │ │ │ │ │ │ │ │ Pyroxenites} │ 50–55 │ 0.5–4 │ 4–10 │ 20–25 Augitites │ │ │ │ │ │ │ │ Leucite rocks │ 48–50 │ 15–20 │ 7–10 │ 1–2 │ │ │ │ Nepheline rocks │ 40–45 │ 8–20 │ 10–20 │ 1–13 ──────────────────────┴────────┴────────────┴────────────┴──────── ──────────────────────┬─────┬────────┬───────┬─────────── │CaO. │ Na₂O. │ K₂O. │P₂O₅. │ │ │ │ ──────────────────────┼─────┼────────┼───────┼─────────── Granite │ │ │ │ Quartz poryhyries} │ 1–2 │ 2–3 │ 4–5 │ 0.05–0.15 Liparite │ │ │ │ │ │ │ │ Syenite │ │ │ │ Orthoclase porphyries}│ 3–5 │ 2–6 │ 4–7 │ trace. Trachyte │ │ │ │ │ │ │ │ Nepheline syenites} │ 2–4 │ 3–7 │ 4–6 │ 0.15 Phonolites │ │ │ │ │ │ │ │ Diorites │ │ │ │ Porphyrites} │ 5–7 │ 2–4 │ 1–2 │ 0.1–0.3 Andesites │ │ │ │ │ │ │ │ Gabbros │ │ │ │ Norites} │6–10 │ 2–4 │ 0.5–2 │ 0.1–0.33 Melaphyrs │ │ │ │ │ │ │ │ Theralites │ │ │ │ Tephrites} │6–10 │ 5–7 │ 2–4 │ trace. Basanites │ │ │ │ │ │ │ │ Peridotites │ │ │ │ Picrite porphyrites} │ 1–4 │ 0–4 │trace. │ 0.0 Limburgites │ │ │ │ │ │ │ │ Pyroxenites} │8–15 │ │ │ Augitites │ │ │ │ │ │ │ │ Leucite rocks │5–10 │ 3–5 │ 5–7 │ 0.5–2 │ │ │ │ Nepheline rocks │4–10 │ 4–8 │ 1–3 │ 0.2 ──────────────────────┴─────┴────────┴───────┴─────────── =37. Origin of Soils.=—The soils in which crops grow and which form the subject of the analytical processes to be hereinafter described have been formed under the combined influences of rock decay and plant and organic growth. The mineral matters of soils have had their origin in the decay of rocks, while the humic and other organic constituents have been derived from living bodies. It is not the object of this treatise to discuss in detail the processes of soil formation, but only to give such general outlines as may bear particularly on the proper conceptions of the principles of soil investigation. =38. The Decay of Rocks.=—The origin and composition of rocks are fully set forth in works on geology and mineralogy. Only a brief summary of those points of interest to agriculture has been given in the preceding pages. The soil analyst should be acquainted with these principles, but for practical purposes he has only to understand the chief factors active in securing the decay of rocks and in preparing the débris for plant growth. The following outline is based on the generally accepted theories respecting the formation of soils.[7] The forces ordinarily concerned in the decay of rocks are: 1. Changes of temperature, including the ordinary daily and monthly changes, and the conditions of freezing and thawing. 2. Moving water or ice. 3. Chemical action of water and air. 4. Influence of vegetable and animal life: (a) Shades the rock or soil surface. (b) Penetrates the rock or soil material with its roots, thus admitting air. (c) Solvent action of roots. (d) Chemical action of decaying organic matter. 5. Earth worms. 6. Bacteria. =39. The Action of Freezing and Thawing.=—In those parts of a rock stratum exposed near the surface of the earth the processes of freezing and thawing have perhaps had considerable influence in rock decay. The expansive force of freezing water is well known. Ice occupies a larger volume than the water from which it was formed. The force with which this expansion takes place is almost irresistible. The phenomenon of bursted water pipes which have been exposed to a freezing temperature is not an uncommon one. While the increase in volume is not large, yet it is entirely sufficient to produce serious results. The way in which freezing affects exposed rock is easily understood. The effect is unnoticeable if the rock be dry. If, on the other hand, it be saturated with water, the disintegrating effect of a freeze must be of considerable magnitude. This effect becomes more pronounced if the intervals of freezing and thawing be of short duration. The whole affected portion of the rock may thus become thoroughly decayed. But even in the most favorable conditions this form of disintegration must be confined to a thin superficial area. Even in very cold climates the frost only penetrates a few feet below the surface, and therefore the action of ice cannot in any way be connected with those changes at great depths, to which attention has already been called. Nevertheless, certain building stones seem very sensitive to this sort of weathering, and the crumbling of the stone in the Houses of Parliament is due chiefly to this cause. On the whole it appears that the action of ice in producing rock decay has been somewhat overrated, although its power must not by any means be denied. But on the other hand a freeze extending over a long time tends to preserve the rocks, and it therefore appears that the entire absence of frost would promote the process of rock decay. At best it must be admitted that frost has affected the earth’s crust only to an insignificant depth, but its influence in modifying the arable part of the soil is of the utmost importance to agriculture. =40. The Action of Glaciers.=—The action of ice in soil formation is not confined alone to the processes just described. At a period not very remote geologically, a great part of our Northern States was covered with a vast field of moving ice. These seas of ice crept down upon us from more northern latitudes and swept before them every vestige of animal and vegetable life. In their movement they leveled and destroyed the crests of hills and filled the valleys with the débris. They crushed and comminuted the strata of rocks which opposed their flow and carried huge boulders of granite hundreds of miles from their homes. On melting they left vast moraines of rocks and pebbles which will mark for all time the termini of these empires of ice. When the ice of these vast glaciers finally melted the surface which they had leveled presented the appearance of an extended plain. No estimate can be made of the enormous quantities of rock material which were ground to finest powder by these glaciers. This rock powder forms to-day no inconsiderable part of those fertile soils which are composed of glacial drift. The rich materials of these soils probably bear a more intimate relation to the rocks from which they were formed than of any other kinds of soil in the world. The rocks were literally ground into a fine powder, and this powder was intimately mixed with the soils which had already been formed _in situ_. The melting ice also left exposed to disintegrating forces large surfaces of unprotected rocks in which decay would go on much more rapidly than when covered with the débris which protected them before the advent of the ice. The area of glacial action extended over nearly all of New England and over the whole area of the northern tier of States. It extended southward almost to the Ohio river, and in some places crossed it. The effect of the ice age in producing and modifying our soil must never be forgotten in a study of soil genesis. It is not a part of our purpose here to study the causes which produced the age of ice. Even a brief reference to some of the more probable ones might be entirely out of place. Before the glacial period it is certain that a tropical climate extended almost, if not quite, to the North Pole. The fossil remains of tropical plants and animals which have been found in high northern latitudes are abundant proofs of this fact. In the opinion of Sterry Hunt,[27] rock decay has taken place largely in preglacial and pretertiary times. The decay of crystalline rocks is a process of great antiquity. It is also a universal phenomenon. The fact that the rocks of the southern part of this country seem to be covered with a deeper débris than those further north is probably due to the mechanical translation of the eroded particles towards the south. The decay and softening of the material were processes necessarily preceding the erosion by aqueous and glacial action. It is possible that a climate may have existed in the earlier geologic ages more favorable to the decay of rocks than that of the present time. =41. Progress of Decay as Affected by Latitude.=—Extensive investigations carried on along the Atlantic side of the country show wide differences in the rate of decay in the same kind of rocks in different latitudes. In general, the progress of decay is more marked toward the south. The same fact is observed in the great interior valleys of the country; at least, everywhere except in the arid and semi-arid regions. Wherever there is a deficiency of water the processes of decay have been arrested. Where the rock strata have been displaced from a horizontal position the progress of decay has been more rapid. This is easily understood. The percolation of water is more easy as the displacement approaches a vertical position. A most remarkable example of this is seen in the rocks of North Carolina.[28] A kind of rock known as trap is found in layers called dikes in the Newark system of rocks in that State. These dikes have been so completely displaced from the horizontal position they at first occupied as to have an almost vertical dip. The edges thus exposed vary from a few feet to nearly 100 feet in thickness. The trap rock in those localities is composed almost exclusively of the mineral dolerite, which is so hard and elastic in a fresh state as to ring like a piece of metal when struck with a hammer. In building a railroad through this region these dikes were in some places uncovered to a depth of forty feet and more. At this depth they were found completely decomposed and with no indications of having reached the lower limit of disintegration. The original hard bluish dolerite has been transformed into a yellowish clay-like mass that can be molded in the fingers and cut like putty. Similar geologic formations in New Jersey and further North do not exhibit anything like so great a degree of decomposition, thus illustrating in a marked degree the fact that freezing weather for a part of the year is a protection against rock decay. The ice of winter at least protects the rocks from surface infiltration, although it can not stop the subterranean solution which must go on continuously. Other things being equal, therefore, it appears that as the region of winter frost is passed the decay of the rocks has been more rapid than in the North, because the chief disintegrating forces act more constantly. =42. The Solvent Action of Water.=—The water of springs and wells is not pure. It contains in solution mineral matters and often a trace of organic matter. The organic matter comes from contact with vegetable matter and other organic materials near the surface of the earth. The mineral matter is derived from the solvent action of the water and its contents on the soil and rocks. The expressions “hard” and “soft” applied to water indicate that it has much or little mineral matter in suspension, as the case may be. When surface and spring waters are collected into streams and rivers they still contain in solution the greater part of the mineral matters which they at first carried. When well or spring waters have more than forty grains of mineral matter per gallon they are not suitable for drinking waters. Mineral waters, so called, are those which carry large quantities of mineral matter, or which contain certain comparatively rare mineral substances which are valued for their medicinal effects. The analysis of spring, well, or river waters will always give some indication of the character of the rocks over which they have passed.[29] The vast quantities of mineral matters carried into oceans and seas are gradually deposited as the water is evaporated. If, however, these matters be very soluble, such as common salt, sulfate of magnesia, etc., they become concentrated, as is seen with common salt in sea waters. In small bodies of waters, such as inland seas, which have no outlet, this concentration may proceed to a much greater extent than in the ocean. As an instance of this, it may be noted that the waters of the Dead Sea and Great Salt Lake are impregnated to a far greater degree with soluble salts than the water of the ocean. The solvent action of water on rocks is greatly increased by the traces of organic or carbonic acids which it may contain. When surface water comes in contact with vegetable matter it may become partially charged with the organic acids which the growing vegetable may contain or decaying vegetable matter produce. Such acids coming in contact with limestone under pressure will set free carbon dioxid. Water charged with carbon dioxid acts vigorously on limestone and other mineral aggregates. If such solutions penetrate deeply below the surface of the earth their activity as solvents may be greatly increased by the higher temperature to which they are subjected. Hence, all these forces combine to disintegrate the rocks, and through such agencies vast deposits of original and secondary rocks have been completely decomposed. The gradual passing of the firm rock into an arable soil is beautifully shown in Fig. 10, a print from a negative taken by Mr. Geo. P. Merrill, near Washington, D. C. FIGURE 10. View on the Broad Branch of Rock Creek, Washington, D. C. The fresh but badly decomposed granitic rock is shown passing upward into material more and more decomposed until it becomes sufficiently pulverulent and soluble to support plant life. The roots showing in the upper part of the picture formerly penetrated the decomposed rock, but have been exposed through quarrying operations. Photograph by George P. Merrill, 1891. ] =43. Action Of Vegetable Life.=—The preliminary condition to vegetation is the formation of soil, but once started, vegetation aids greatly in the decomposition of rocks. Some forms of vegetation, as the lichens, have apparently the faculty of growing on the bare surface of rocks, but the higher order requires at least a little soil. The vegetation acts by shading the surface and thus rendering the action of water more effective, by mechanically separating the rock particles by means of its penetrating roots and by the positive solvent action of the root juices. The rootlets of plants in contact with limestone or marble dissolve large portions of these substances, and while their action on more refractory rocks is slower, it must be of considerable importance. The organic matter introduced into the soil by vegetation also promotes decay still further both directly and by the formation of acids of the humic series. This matter also furnishes a considerable portion of carbon dioxid which is carried by the water to assist in its solvent action. =44. Action of Earth-Worms.=—Of animal organisms those most active in the formation of soil are earth-worms. The work of earth-worms has been exhaustively studied by Darwin.[30] The worms not only modify the soil by bringing to the surface portions of the subsoil, but also influence its physical state by making it more porous and pulverulent. According to Darwin the intestinal content of worms has an acid reaction, and this has an effect on those portions of the soil passing through their alimentary canal. The acids, which are formed in the upper part of the digestive canal are neutralized by the carbonate of lime secreted by the calciferous glands of the worms thus neutralizing the free acid and changing the reaction to alkaline in the lower part of the canal. There is a fair presumption that the acids of the worm are of a humic nature. The worms further modify the composition of the soil by drawing leaves and other organic matter into their holes, and leaving therein a portion of such matter which is gradually converted into humus. Stockbridge[31] gives a striking illustration of this process due to an experiment by von Hensen. Darwin estimates that about eleven tons of organic matter per acre are annually added to the soil in regions where worms abound. A considerable portion of the ammonia in the soil at any given time may also be due to the action of worms, as much as 0.18 per cent of this substance having been found in their excrement. It is probable that nearly the whole of the vegetable matter in the soil passes sooner or later through the alimentary canals of these ceaseless soil builders, and is converted into the form of humus. =45. Action of Bacteria.=—The intimate relations which have been found to subsist between certain minute organisms and the chemical reactions which take place in the soil is a sufficient excuse for noting the effect of other similar organisms in the formation of soils. In addition to the usual forces active in decomposing rocks Müntz[32] has described the effects of a nitrifying bacillus contributing to the same purpose. According to him the bare rock usually furnishes a purely mineral environment where organisms cannot be developed unless they are able to draw their nourishment directly from the air. Some nitrifying organisms belong to this class. It has been shown that these bodies can be developed by absorbing from the ambient atmosphere carbonate of ammonia and vapors of alcohol, the presence of which has been determined in the air. According to the observations of Winogradsky, they assimilate even the carbon of the carbon dioxid just as vegetables do which contain chlorophyl. Thus even in the denuded rocks of high mountains the conditions for the development of all these inferior organisms exist. In examining the particles produced by attrition, it is easily established that they are uniformly covered by a layer of organic matter evidently formed by microscopic vegetations. Thus we see, in the very first products of attrition, appearing upon the rocky particles the characteristic element of vegetable soil, viz., humus, the proportion of which increases rapidly with the products of disaggregation collected at the foot of declivities until finally they become covered with chlorophyliferous plants. In a similar manner the presence of nitrifying organisms has been noted upon rocky particles received in sterilized tubes, and cultivated in an appropriate environment where they soon produce nitrification. The naked rocks of the Alps, the Pyrenees, the Auvergnes and the Vosges, comprise mineralogical types of the most varied nature, _viz._, granite, porphyry, gneiss, micaschist volcanic rocks and limestones and all these have shown themselves to be covered with the nitrifying ferment. It is known that below a certain temperature these organisms are not active; their action upon the rock is, therefore, limited to the summer period. During the cold season their life is suspended but they do not perish, inasmuch as they have been found living and ready to resume all their activity after an indefinite sleep on the ice of the glaciers where the temperature is never elevated above zero. The nitrifying ferment is exercised on a much larger scale in the normal conditions of the lower levels where the rock is covered with earth. This activity is not limited to the mass of rock but is continued upon the fragments of the most diverse size scattered through the soil and it gradually reduces them to a state of fine particles. It is therefore a phenomenon of the widest extension. The action of these micro-organisms according to Müntz is not confined to the surface but extends to the most interior particles of the rocky mass. Where, however, there is nothing of a nitrogenous nature, to nitrify such an organism must live in a state of suspended animation. When the extreme minuteness of these phenomena is considered there may be a tendency to despise their importance, but their continuity and their generality in the opinion of Müntz place them among the geologic causes to which the crust of the earth owes a part of its actual physiognomy and which particularly have contributed to the formation of the deposits of the comminuted elements constituting arable soil. The general action of nitrifying organisms in the soil, the nature of these bodies, and the method of isolating and identifying them will be fully discussed in another part of this work. =46. Action of the Air.=—The air itself takes an active part in rock decay. Wherever rocks are exposed to decay, there air is found or, at least, the active principle of air, _viz._, oxygen. The air not only penetrates to a great depth in the earth, but is also carried to much greater depths by water which always holds a greater or less quantity of air in solution. The oxygen of the air is thus brought into intimate contact with the disintegrating materials and in a condition to assist wherever possible in the decomposing processes. The oxygen acts vigorously on the lower oxids of iron, converting them into peroxids, and thus tends to produce decay. There are other constituents of rocks which oxygen affects injuriously and thus helps to their final breaking up. It is true that, as a rule, the constituents of rocks are already oxidized to nearly as high a degree as possible, and on these constituents of course the air would have no effect. But on others, especially when helped by water with the other substances it carries in solution, the air may greatly help in the work of destruction. In a general view, the action of the air in soil formation may be regarded as of secondary importance, and to depend chiefly on the oxidation of the lower to the higher basic forms. These processes, while they seem of little value, have, nevertheless, been of considerable importance in the production of that residue of rock disintegration which constitutes the soil. =47. Classification of Soils According to Deposition.=—In regard to their deposition soils are divided into five classes: 1. Those which are formed from the decomposition of crystalline or sedimentary rocks or of unconsolidated sedimentary material _in situ_. 2. Those which have been moved by water from the place of their original formation and deposited by subsidence (bottom lands, alluvial soils, lacustrine deposits, etc.). 3. Those which have been deposited as débris from moving masses of ice (glacial drift). 4. Soils formed from volcanic ashes or from materials moved by the wind and deposited in low places or in hills or ridges. 5. Those formed chiefly from the decay of vegetable matter, (tule, peat, muck). =48. Qualities of Soils.=—In respect of quality, soils have been arbitrarily divided into many kinds. Some of the more important of these divisions are as follows: 1. _Sand._ Soils consisting almost exclusively of sand. 2. _Sandy Loams._ Soils containing some humus and clay but an excess of sand. 3. _Loams._ Soils inclining neither to sand nor clay and containing some considerable portions of vegetable mold, being very pulverulent and easily broken up into loose and porous masses. 4. _Clays._ Stiff soils in which the silicate of alumina and other fine mineral particles are present in large quantity. 5. _Marls._ Deposits containing an unusual proportion of carbonate of lime, with often some potash or phosphoric acid resulting from the remains of sea-animals and plants. 6. _Alkaline._ Soils containing carbonate and sulfate of soda, or an excess of these alkaline and other soluble mineral substances. 7. _Adobe._ A fine grained porous earth of peculiar properties hereinafter described. 8. _Vegetable._ Soils containing much vegetable débris in an advanced state of decomposition. When such matter predominates or exists in large proportion in a soil the term tule, peat or muck is applied to it. With the exception of numbers six, seven and eight these types of soil are so well-known as to require no further description for analytical purposes. The alkaline, adobe and vegetable soils on the contrary demand further study. =49. Alkaline Soils.=—The importance of a more extended notice of this class of soils for analytical purposes is emphasized by their large extent in the United States. Chiefly through the researches of Hilgard attention has been called to the true character of these soils which are found throughout a large part of the Western United States and which are known by the common name of alkali. The following description of the origin of these soils is compiled chiefly from Hilgard’s papers on this subject. Wherever the rain-fall is scanty, and especially where the rains do not come at any one time with sufficient force to thoroughly saturate the soil and carry down through the subsoil and off through the drainage waters the alkali contained therein, favorable conditions exist for the production of the alkaline soil mentioned above. The peculiar characteristic of this soil is the efflorescence which occurs upon its surface and which is due to the raising of soluble salts in the soil by the water rising through capillary attraction and evaporating from the surface, leaving the salts as an efflorescence. Soils which contain a large amount of alkali are usually very rich in mineral plant food, and if the excess of soluble salt could be removed, these lands under favorable conditions of moisture would produce large crops. The formation of the alkali may be briefly described as follows: By the decomposition of the native rocks, certain salts soluble in water are formed. These salts in the present matter are chiefly sodium and potassium sulfates, chlorids and carbonates. The salts of potash together with those of lime are more tenaciously held by the soil than the soluble salts of soda, and the result of this natural affinity of the soil for soluble potash, lime and magnesian salts is seen in the formation at the surface of the earth, by the process of evaporation above described, of a crust of alkaline material which is chiefly composed of the soluble salts of soda. In countries which have a sufficient amount of rain-fall, these soluble salts are carried away either by the surface drainage or by the percolation of water through the soil, and the sodium chlorid is accumulated in this way in the waters of the ocean. But where a sufficient amount of rain-fall does not occur, these soluble salts carried down by each shower only to a certain depth rise again on the evaporation of the water, reinforced by any additional soluble material which may be found in the soil itself. The three most important ingredients of the alkali of the lands referred to are sodium chlorid, sulfate, and carbonate. When the latter salt, namely, sodium carbonate, is present in predominant quantity, it gives rise to what is popularly known as black alkali. This black color is due to the dark colored solution which sodium carbonate makes with the organic matters or humus of the soil. The black alkali is far more injurious to growing vegetation than the white alkali composed chiefly of sodium sulfate and chlorid. This black alkali has been very successfully treated by Hilgard[33] by the application of gypsum which reacting with the sodium carbonate produces calcium carbonate and sodium sulfate, thus converting the black into the white alkali and adding an ingredient in the shape of lime carbonate to stiff soils which tends to make them more pulverulent and easy of tillage. This method of treatment, however, as can be easily seen, is only palliative, the whole amount of the alkaline substances being still left in the soil, only in a less injurious form. The only perfect remedy for alkaline soils, as has been pointed out by Hilgard, is in the introduction of underdrainage in connection with irrigation. The partial irrigation of alkaline soils, affording enough moisture to carry the alkali down to and perhaps partially through the subsoil, can produce only a temporary alleviation of the difficulties produced by the alkali. Subsequent evaporation may thus increase the amount of surface incrustation. For this reason in many cases the practice of irrigation without underdrainage may completely ruin an otherwise fertile soil by slowly increasing the amount of alkali in the soil by the total amount of the alkaline material added in the waters of irrigation. As Hilgard has pointed out, if a soil can be practically freed from alkali by underdrainage connected with a thorough saturation by irrigation, it may be centuries before the alkali will accumulate in that soil again when ordinary irrigation only is practiced. It may thus become possible to reclaim large extents of alkaline soil little by little by treating them with an excess of irrigation water in connection with thorough underdrainage. The composition of the alkali on the surface of the soil due to the causes above set forth is thoroughly illustrated by the analyses of Hilgard and Weber, which follow: TABLE SHOWING COMPOSITION OF ALKALI SALTS IN SAN JOAQUIN VALLEY. ═════════════╤════════════════════════════════════════════ │ FRESNO COUNTY. ─────────────┼──────────────────────────────────────────── │ Sections 13 and 24 T. 14 S. R. 19 E., 4 │ miles S. W. from Fresno. │ ─────────────┼────────┬─────────────────────────────────── │ Alkali │ Alkali Spot, 1889. │ soil, │ │ 1888. │ ─────────────┼────────┼────────┬────────┬────────┬──────── │ „ │ 1 inch │ 18 │ 26 │ 42 │ │surface.│ inches │ inches │ inches │ │ │ bel. │ bel. │hardpan. │ │ │surface.│surface.│ ─────────────┼────────┼────────┼────────┼────────┼──────── Soluble salts│ │ 0.76 │ 0.20 │ 0.18 │ 0.16 in 100 │ │ │ │ │ parts soil │ │ │ │ │ Potassium │ │ │ │ │ sulfate │ │ │ │ │ [D]Potassium │ │ │ │ │ nitrate │ │ │ │ │ Potassium │ │ │ │ │ carbonate │ │ │ │ │ (Saleratus)│ │ │ │ │ Sodium │ large │ small │ small │ very │ very sulfate │ │ │ │ slight │ slight (Glauber’s │ │ │ │ │ salt) │ │ │ │ │ Sodium │ very │ large │ small │ large │ large carbonate │ slight │ │ │ │ (Sal-soda) │ │ │ │ │ Sodium │chiefly │moderate│chiefly │moderate│moderate chlorid │ │ │ │ │ (Common │ │ │ │ │ salt) │ │ │ │ │ [D]Sodium │ │ │ │ │ phosphate │ │ │ │ │ Calcium │moderate│ small │ very │ very │ very sulfate │ │ │ slight │ slight │ slight (Gypsum) │ │ │ │ │ Magnesium │ │ │ │ │ sulfate │ │ │ │ │ (Epsom │ │ │ │ │ salt) │ │ │ │ │ Organic │ │ │ │ │ matter │ │ │ │ │ ─────────────┴────────┴────────┴────────┴────────┴──────── ═════════════╤══════════════════════════════════════════════════ │ FRESNO COUNTY. ─────────────┼────────────────┬────────────────┬───────┬──────── │ Miss Austin’s │ N.W. Cor. N ½ │Easton.│Emigr’nt │ Ranch, Central │Sec. 20 T. 14 S.│ │ Ditch. │ Colony. │ R. 21 E. │ │ ─────────────┼───────┬────────┼───────┬────────┼───────┼──────── │Surface│Surface │Surface│Surface │ „ │ „ │ soil, │ soil, │ soil. │ soil. │ │ │No. 1. │ No. 2. │ │ │ │ ─────────────┼───────┼────────┼───────┼────────┼───────┼──────── │ „ │ „ │ „ │ „ │ „ │ „ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ─────────────┼───────┼────────┼───────┼────────┼───────┼──────── Soluble salts│ 3.54 │ 1.90 │ 1.20 │ 2.69 │ │ in 100 │ │ │ │ │ │ parts soil │ │ │ │ │ │ Potassium │ small │moderate│ │ │ │ sulfate │ │ │ │ │ │ [D]Potassium │ │ small │ │ │ │ nitrate │ │ │ │ │ │ Potassium │ │ │ │ │ │ carbonate │ │ │ │ │ │ (Saleratus)│ │ │ │ │ │ Sodium │ large │ large │ much │moderate│ large │ sulfate │ │ │ │ │ │ (Glauber’s │ │ │ │ │ │ salt) │ │ │ │ │ │ Sodium │ small │chiefly │ small │ small │ │chiefly carbonate │ │ │ │ │ │ (Sal-soda) │ │ │ │ │ │ Sodium │chiefly│ large │chiefly│chiefly │ large │ little chlorid │ │ │ │ │ │ (Common │ │ │ │ │ │ salt) │ │ │ │ │ │ [D]Sodium │ │ │ │ │ │ phosphate │ │ │ │ │ │ Calcium │ small │moderate│ small │ small │ much │ sulfate │ │ │ │ │ │ (Gypsum) │ │ │ │ │ │ Magnesium │ │ small │ │ │ much │ sulfate │ │ │ │ │ │ (Epsom │ │ │ │ │ │ salt) │ │ │ │ │ │ Organic │ │ │ │ │ │ matter │ │ │ │ │ │ ─────────────┴───────┴────────┴───────┴────────┴───────┴──────── Footnote D: Very generally present, but not always in quantities sufficient for determination. ═════════════════════╤═════════════════════════════════════════════════ │ TULARE COUNTY. ─────────────────────┼───────┬───────┬────────┬───────┬────────┬─────── │Goshen │Peopl’s│ Near │Visalia│Lemoore │Tulare │ │ Ditch │ Lake │ │ │ Exp’t │ │ │ Tulare │ │ │Station ─────────────────────┼───────┼───────┼────────┼───────┼────────┼─────── │Surf’ce│Alkali │Surf’ce │Surf’ce│ Alkali │Alkali │ soil │ crust │ soil │ soil │ crust │ crust ─────────────────────┼───────┼───────┼────────┼───────┼────────┼─────── Soluble salts in 100 │ 1.40│ │ 0.83│ 1.26│ │ parts soil │ │ │ │ │ │ Potassium sulfate │ │ │ │ │ │ small [E]Potassium nitrate │ │ │ │ │ │ small Potassium carbonate │ │ │ │ 18.80│ │ (Saleratus) │ │ │ │ │ │ Sodium sulfate │ 44.24│ 1.22│31.30[F]│ 13.4│chiefly │ 32.8 (Glauber’s salt) │ │ │ │ │ │ Sodium carbonate │ 32.98│ 88.09│ 18.2│ 45.3│ │ 36.16 (Sal-soda) │ │ │ │ │ │ Sodium chlorid │ 16.74│ 1.00│ │ 4.4│ little │ 31.16 (Common salt) │ │ │ │ │ │ [E]Sodium phosphate │ 1.97│ │ 0.22│ 10.4│ │ Calcium sulfate │ │ │ │ │ little │ (Gypsum) │ │ │ │ │ │ Magnesium sulfate │ │ │ │ 8.1│moderate│ (Epsom salt) │ │ │ │ │ │ Organic matter │ 1.59│ 9.21│ 7.5│ │ │ 5.37 ─────────────────────┴───────┴───────┴────────┴───────┴────────┴─────── ═════════════╤════════════════════════════════════════════════════════ │ KERN COUNTY. ─────────────┼──────────────────────────────────────────────────────── │ Alkali crusts from the Smyrna artesian belt. Townships │ 25 and 26 R. 23 E. W. S. W. from Delano, S. P. R. R. ─────────────┼─────┬────────┬────────┬────────┬─────┬─────┬─────┬───── │No. 1│ No. 2 │ No. 3 │ No. 4 │No. 5│No. 6│No. 7│No. 8 │ │ │ │ │ │ │ │ ─────────────┼─────┼────────┼────────┼────────┼─────┼─────┼─────┼───── Soluble salts│ │ │ │ │ │ │ │ in 100 │ │ │ │ │ │ │ │ parts soil │ │ │ │ │ │ │ │ Potassium │ │ │ │ │ │ │ │ sulfate │ │ │ │ │ │ │ │ [E]Potassium │ │ │ │ │ │ │ │ nitrate │ │ │ │ │ │ │ │ Potassium │ │ │ │ │ │ │ │ carbonate │ │ │ │ │ │ │ │ (Saleratus)│ │ │ │ │ │ │ │ Sodium │small│moderate│moderate│moderate│large│small│small│small sulfate │ │ │ │ │ │ │ │ (Glauber’s │ │ │ │ │ │ │ │ salt) │ │ │ │ │ │ │ │ Sodium │ │ │ │ │ │ │ │ carbonate │ │ │ │ │ │ │ │ (Sal-soda) │ │ │ │ │ │ │ │ Sodium │large│moderate│ large │ large │small│large│small│large chlorid │ │ │ │ │ │ │ │ (Common │ │ │ │ │ │ │ │ salt) │ │ │ │ │ │ │ │ [E]Sodium │ │ │ │ │ │ │ │ phosphate │ │ │ │ │ │ │ │ Calcium │small│ small │ small │ small │small│small│small│small sulfate │ │ │ │ │ │ │ │ (Gypsum) │ │ │ │ │ │ │ │ Magnesium │small│ small │ small │ small │small│small│small│small sulfate │ │ │ │ │ │ │ │ (Epsom │ │ │ │ │ │ │ │ salt) │ │ │ │ │ │ │ │ Organic │ │ │ │ │ │ │ │ matter │ │ │ │ │ │ │ │ ─────────────┴─────┴────────┴────────┴────────┴─────┴─────┴─────┴───── ═════════════╤══════════════ │ KERN COUNTY. ─────────────┼───────┬────── │Summer.│ Kern │ │Island ─────────────┼───────┼────── │Alkali │Alkali │ crust │crust ─────────────┼───────┼────── Soluble salts│ │ in 100 │ │ parts soil │ │ Potassium │ │ 4.72 sulfate │ │ [E]Potassium │ │ nitrate │ │ Potassium │ │ carbonate │ │ (Saleratus)│ │ Sodium │ 19.20│ 70.61 sulfate │ │ (Glauber’s │ │ salt) │ │ Sodium │ │ 14.82 carbonate │ │ (Sal-soda) │ │ Sodium │ 37.14│ 4.13 chlorid │ │ (Common │ │ salt) │ │ [E]Sodium │ │ phosphate │ │ Calcium │ 0.96│ 0.08 sulfate │ │ (Gypsum) │ │ Magnesium │ 18.31│ sulfate │ │ (Epsom │ │ salt) │ │ Organic │ 20.87│ matter │ │ ─────────────┴───────┴────── Footnote F: Common and Glauber’s salts. =50. Adobe Soils.=—In many parts of the arid regions of this country which can be recovered for agricultural purposes by irrigation the soil has peculiar characteristics. The name adobe as commonly used applies to both the sundried bricks of the arid regions of the West and Southwest, and to the materials of which they are composed. The material is described by Russell[34] as a fine grained porous earth, varying in color through many shades of gray and yellow, which crumbles between the fingers, but separates most readily in a vertical direction. The coherency of the material is so great that vertical scarps will stand for many years without forming a noticeable talus slope. _Distribution._—The area over which adobe forms a large part of the surface has not been accurately mapped, but enough is known to indicate that it is essentially co-extensive with the more arid portions of this country. In a very general way it may be considered as being limited to the region in which the mean annual rain-fall is less than twenty inches. It forms the surface over large portions of Colorado, New Mexico, Western Texas, Arizona, Southern California, Nevada, Utah, Southern Oregon, Southern Idaho, and Wyoming. Adobe occurs also in Mexico and may there reach a greater development than in the United States, but observations concerning it south of the Rio Grande are wanting. In the United States it occurs from near the sea-level in Arizona, and even below the sea-level in Southern California, up to an elevation of at least six or eight thousand feet, along the eastern border of the Rocky Mountains, and in the elevated valleys of New Mexico, Colorado, and Wyoming. It occupies depressions of all sizes up to valleys having an area of hundreds of square miles. Although occurring throughout the arid region, it can be studied to best advantage in the drainless and lakeless basins in Nevada, Utah, and Arizona. _Composition._—When examined under the microscope, the adobe is seen to be composed of irregular, unassorted flakes and grains, principally quartz, but fragments of other minerals are also present. An exhaustive microscopic study has not been made, but the samples examined from widely-separated localities were very similar. The principal characteristics observed were the extreme angularity of the particles composing the deposit and the undecomposed condition of the various minerals entering into its composition. It is to be inferred from this that the material was not exposed even to a very moderate degree of friction, and had not undergone subaerial decay before being deposited. Adobe collected, at typical localities is so fine in texture that no grit can be felt when it is rubbed between the fingers; in other instances it contains angular rock fragments of appreciable size. The composition of the material is illustrated by the following analyses: ANALYSES OF ADOBE. BY L. G. EAKINS. Constituents. No. 1. No. 2. No. 3. No. 4. Sante Fe, New Fort Wingate, Humboldt, Salt Lake Mexico. New Mexico. Nevada. City, Utah. SiO₂ 66.69 26.67 44.64 19.24 Al₂O₃ 14.16 0.91 13.19 3.26 Fe₂O₃ 4.38 0.64 5.12 1.09 MnO 0.09 trace 0.13 trace CaO 2.49 36.40 13.91 38.94 MgO 1.28 0.51 2.96 2.75 K₂O 1.21 trace 1.71 trace Na₂O 0.67 trace 0.59 trace CO₂ 0.77 25.84 8.55 29.57 P₂O₅ 0.29 0.75 0.94 0.23 SO₃ 0.41 0.82 0.64 0.53 Cl 0.34 0.07 0.14 0.11 H₂O 4.94 2.26 3.84 1.67 Organic matter 2.00 5.10 3.43 2.96 ————— ————— ————— —————— 99.72 99.97 99.84 100.35 =51. Vegetable Soils.=—The heavy soils whose origin has been described are essentially of a mineral nature. The quantity of organic matter in such soils may vary from a mere trace to a few per cent, but they never lose their mineral predominance. When a soil on the other hand is composed almost exclusively of vegetable mold it belongs to quite another type. Such soils are called tule, peat or muck. In this country there are thousands of acres of peat or muck soils; the largest contiguous deposits being found in Southern Florida. The origin of these soils is easily understood. Whenever rank vegetation grows in such a location as to secure for the organic matter formed a slow decay there is a tendency to the accumulation of vegetable mold in shallow water or on marshy ground and where conditions are favorable to such accumulations. In Florida the muck soils have been accumulated about the margins of lakes. During the rainy season the marshes bordering these are partly covered with water, but the vegetation is very luxuriant. The water protects the vegetable matter from being destroyed by fire. It therefore accumulates from year to year and is gradually compacted into quite a uniform mass of vegetable mold. The composition of the muck is illustrated in the following table which shows the character of the layers at one, two and three feet in depth:[35] Carbon. Hydrogen. Nitrogen. Volatile matter. 1 foot 57.67 per cent 4.48 per cent 2.24 per cent 90.60 per cent 2 feet 47.07 „ 5.15 „ 1.40 „ 72.00 „ 3 feet 8.52 „ 0.53 „ 0.31 „ 15.00 „ In this sample, No. 3, the muck was only three feet deep, resting on pure sand. As the bottom of the deposit is approached the admixture of sand becomes greater and the percentage of organic matter less. No reliable estimate of the time which has been required to form these deposits can be given, but in the Okeechobee region in Florida the deposit of vegetable mold in some places exceeds ten feet in depth. The purest muck or peat soils contain only small quantities of potash and phosphoric acid, and especially is this true of the Florida mucks which have been formed of vegetable growth containing very little mineral matter. It is not at all probable that the flora now growing on any particular area of virgin peat contains all the plants that have contributed to its formation. The principal vegetable growths now going to make up the muck soils of Florida are the following: Common names. Botanical names. Saw grass Cladium effusum Yellow pond lily Nymphea flava Maiden cane grass Panicum Curtisii Alligator Wampee Pontederia cordata Sedge Cyperus species Fern brake Osmunda „ Mallow Malva „ Broom sedge Andropogon „ Arrow weed Sagittaria „ The above are only the plants growing in the greatest profusion and do not include all which are now contributing to increase the store of vegetable débris. =52. Humus.=—The active principle of vegetable mold is called humus, a term used to designate in general the products of the decomposition of vegetable matter as they are found in soils. In peat and muck are found a mixture of humus with undecomposed or partially decomposed vegetation. According to Kostytchoff[36] vegetable matter decays under the influence of molds and bacteria. Molds alone produce the dark colored matters which give soils rich in vegetable matter, their color. One chief characteristic of humus is its richness in nitrogen. Black Russian soil contains from 4 to 6.65 per cent of nitrogen. This soil is estimated to contain sixty million organisms per gram and much of the nitrogen which it holds must be in the form of proteids. The first development in decaying vegetable matter is of bacteria and there is a tendency of the decaying matter to become acid. This causes a decay of the bacteria and the ammonia produced by this neutralizes the acid. The various kinds of mold grow when the reaction becomes neutral. Afterwards the bacteria and the molds develop together. This statement of Kostytchoff is not a very satisfactory explanation of even our limited knowledge of the decomposition of organic matters in the soil. Ammonia and ammonia salts are formed not by the decay of some forms of bacteria but by the activities of other forms. Warington found that in nitrification there were three distinct forms of bacteria concerned in the final products of ammonia, nitrites, and nitrates. Humus always contains easily decomposable matter and consequently the rate of decay at any observed periods is nearly the same. In humus which is produced above the water-level Kostytchoff states that all trace of the vegetable structure is destroyed by the leaves being gnawed and passed through the bodies of caterpillars and wire-worms. Under the water-level the vegetable structure is preserved and peat results. The decay of humus is most rapid in drained and open soils. For this reason the presence of clay in a soil promotes the accumulation of humus. Inferior organisms are the means of diffusing organic matter through the soil. The mycelia of fungi grow on a dead root for instance, ramify laterally and thus carry organic matter outward and succeeding organisms extend this action and the soil becomes darkened in proportion. Humic acid in black soil is almost exclusively in combination with lime. A more common view of the difference between the formation of humus above and below the water-level is that above the water-level there is a very free access of air and even the harder parts of the leaf skeleton can be oxidized through the agency of bacteria, while under the water-level there is a very limited supply of air and this oxidation cannot proceed as rapidly. The harder parts of the leaf skeleton are preserved, and from the freer access of air humus is oxidized more readily in drained and open soils, and accumulates in clay soils where there is less circulation of air. The real composition of humus is a matter which has never been definitely determined. Composed of many different but closely related substances it has been difficult to isolate and determine them. Stockbridge[37] gives the following composition of the bodies which form the larger part of humus: Ulmin and Ulmic Acid. Carbon 67.1 per cent Corresponding to C₄₀H₂₈O₁₂ + H₂O. Hydrogen 4.2 „ „ Oxygen 8.7 „ „ Humin and Humic Acid. Carbon 64.4 per cent Corresponding to C₂₁H₂₄_O₁₂ + 3H₂O Hydrogen 4.3 „ „ Oxygen 31.3 „ „ Crenic Acid. Carbon 44.0 per cent Corresponding to C₁₂H₁₂O₈? Hydrogen 5.5 „ „ Nitrogen 3.9 „ „ Oxygen 46.6 „ „ Apocrenic Acid. Carbon 34.4 per cent Corresponding to C₂₄H₂₄O₁₂? Hydrogen 3.5 „ „ Nitrogen 3.0 „ „ Oxygen 39.1 „ „ He further states that there are, aside from these humus compounds, others still less known and the action of which is not yet understood; among them xylic acid, C₂₄H₃₀O₁₇, saccharic acid, C₁₄H₁₈O₁₁, glucinic acid, C₁₂H₂₂O₁₂, besides a brown humus acid containing carbon, 65.8 per cent, and hydrogen, 6.25 per cent, and a black humus acid yielding carbon, 71.5 per cent, and hydrogen, 5.8 per cent. According to Mulder humic acid has the following composition, C₆₀H₅₄O₂₇, while Thenard[38] ascribes to it the formula, C₂₄H₁₀O₁₀. At the present time we can only regard the various forms of humus bodies as mixtures of many substances mostly of an acid nature and resulting from a gradual decomposition of organic matter under conditions which partially exclude free access of oxygen. For analytical purposes it is only necessary to separate these bodies by the best approved processes. A further knowledge of their composition can then be derived by determining the percentages of carbon dioxid and water which they yield on combustion. =53. Soil and Subsoil.=—Many subdivisions have been made of the above varieties of soil, but they have little value for analytical purposes. For convenience in description for agricultural purposes, the soil, however, is further divided into soil and subsoil. In this sense the soil comprises that portion of the surface of the ground, usually from four to nine inches deep, containing most of the organic remains of plants and animals and in which air circulates more or less freely for the proper humification of the organic matter, which usually gives a darker color to the soil than to the subsoil. The subsoil proper lies below this, and has usually more characteristic properties, especially in respect of color and texture, as it has been less influenced by artificial conditions of cultivation and the remains of vegetation. The subsoil extends to an indefinite depth and is limited usually by deposits of undecomposed or partly decomposed rock matter, or by layers of clay, sand or gravel. Inasmuch, however, as the influence of the subsoil on growing crops is of little importance below the depth of eighteen inches the analysis of samples from a greater depth has more of a geologic than agricultural value. Hilgard regards as subsoil whatever lies beneath the line of change, or below the minimum depth of six inches. But should the change of color occur at a greater depth than twelve inches, the soil specimen should nevertheless be taken to the depth of twelve inches only, which is the limit of ordinary tillage; then another specimen from that depth down to the line of change, and then the subsoil specimens beneath that line. The depth to which the last should be taken will depend upon circumstances. It is always desirable to know what constitutes the foundation of a soil to the depth of three feet at least, since the question of drainage, resistance to drought, etc., will depend essentially upon the nature of the substratum. But in ordinary cases ten or twelve inches of subsoil will be sufficient. The sample should be taken in other respects precisely like that of the surface soil, while that of the material underlying this subsoil may be taken with less exactness, perhaps at some ditch or other easily accessible point, and should not be broken up like the other specimens. In the method of soil sampling adopted by the Royal Agricultural College of England, the soil is regarded as that portion of the surface of the ground which is reached by ordinary tillage operations, generally being from six to nine inches deep; the subsoil is that portion which is ordinarily not touched in plowing. AUTHORITIES CITED IN PART FIRST. Footnote 1: Comptes rendus, Tome 110, p. 1271. Footnote 2: Wyatt, Phosphates of America, p. 66. Footnote 3: Engineering and Mining Journal, August 23, 1890. Footnote 4: American Journal of Science, Vol. 41, February, 1891. Footnote 5: Preliminary Sketch of Florida Phosphates, Author’s edition, pp. 18, et seq. Footnote 6: Journal für praktische Chemie, 1st series, Band 38, S. 388. Footnote 7: Annual Report Connecticut Experiment Station, 1890, p. 72. Footnote 8: Annual Report Massachusetts Experiment Station, 1887, p. 233. Footnote 9: Bulletin 21, Rhode Island Experiment Station, 1893. Footnote 10: Chemical Composition of Food-Fishes. Report of U. S. Commissioner of Fish and Fisheries, 1888, pp. 679 et seq. Footnote 11: G. Brown Goode, American Naturalist, Vol. 14, July, 1890. Footnote 12: Comptes rendus, Tome 101, 1885, pp. 65, et seq. Footnote 13: Royal Agricultural Society Journal, Vol. 13, 1852, pp. 349 et seq. Footnote 14: Gîtes Mineraux, par Fuchs et DeLauny, Tome 1, p. 425. Footnote 15: El Salitre de Chile; René F. LeFeuvre y Artūro Dagnino, 1893, p. 12. Footnote 16: Crampton, American Chemical Journal, Vol. II, 1890, p. 227. Footnote 17: Potash, pamphlet of German Kali Works, pp. 3, 4. Footnote 18: Gîtes Mineraux, p. 429. Footnote 19: Bulletin of the Philosophical Society of Washington, Vol. II, p. 142. Footnote 20: Handbook for the Department of Geology of the U. S. National Museum, by Geo. P. Merrill. Footnote 21: Vid. supra, p. 506. Footnote 22: Vid. supra, Plate 120. Footnote 23: Merrill, op. cit. p. 521. Footnote 24: Merrill, op. cit. p. 536. Footnote 25: Merrill, op. cit. p. 545. Footnote 26: Merrill, op. cit. p. 547. Footnote 27: Mineral Physiology and Physiography, p. 251. Footnote 28: Bulletin No. 52, United States Geological Survey, p. 16. Footnote 29: bis (p. 48), Vid. supra, p. 38. Footnote 30: The Formation of Vegetable Mold through the Action of Worms. Footnote 31: Rocks and Soils, pp. 131–2. Footnote 32: Comptes rendus, Tome 110, p. 1370. Footnote 33: Bulletin No. 83, California Experiment Station. Footnote 34: Geological Magazine, Vol. 7, No. 6, pp. 291–92. Footnote 35: Wiley, Agricultural Science, 1893, pp. 106 et seq. Footnote 36: Travaux de la Société des Naturalistes St. Petersburg, Tome 20, 1889. Footnote 37: Rocks and Soils, p. 134. Footnote 38: Beilstein’s Handbuch der Organischen Chemie, Band I, Ss. 891–2. PART SECOND. TAKING SAMPLES OF SOIL FOR ANALYSIS. =54. General Principles.=—It would be unwise to attempt to give any single method of taking soil samples as the only one to be practiced in all circumstances. In the methods which follow it is believed will be found directions for every probable case. The particular method to be followed will in each case have to be determined by circumstances. The sole object in taking a sample of soil should be to have it representative of the type of soils to which it belongs. Every precaution should be observed to have each sample measure up to that standard. The physical and chemical analyses of soils are long and tedious processes and are entirely too costly to be applied to samples which represent nothing but themselves. The particular place selected for taking the samples as well as the method employed are also largely determined by the point of view of the investigations. The collection of samples to illustrate the geologic or mineralogical relations of soils is quite a different matter from gathering portions to represent their agricultural possibilities. In a given area the sum of plant food in the soil would only be determined by the analyses of samples from that particular field, while samples illustrating geologic relations could or should be taken at widely distant points. Again the chemist is content with a sample of a few grams in weight while the physicist would require a much larger quantity. Much popular ignorance exists respecting the importance of the collection of soil samples. As an illustration of this may be cited a recent instance in which a sample of soil was received by the author with a request for a complete analysis and a statement of the kinds of crops it was suited to grow. No data relating to the locality in which the sample was taken accompanied this request. The sample itself, which weighed a little less than 3.6 grams, was not a soil at all in an agricultural sense but a highly ferruginous sand. The collector of samples who understands the purpose for which he is working will find among the approved methods which follow some one or some combination of methods, by means of which his work can be made successful. In these cases it is the collector rather than the method on which reliance must be placed to secure properly representative samples. =55. General Directions for Sampling.=—The locality having been selected which presents as nearly as possible the mean composition of the field a square hole is dug with a sharp spade to the depth of eighteen inches. The walls of this hole should be smooth and perpendicular. The soil to the depth of six to nine inches is then removed from the sides of the hole in a slice about four inches thick; or the sample of soil may be taken to the depth indicated by a change of color. Any particles which fall into the bottom of the hole are carefully collected and added to the parts adhering to the spade. The whole is thrown into a suitable vessel for removal to the laboratory. The sample of soil having been thus secured, the subsoil is taken in the same way. To insure uniformity in the samples, it is well to take several of them from the same field. Where more than one sample is taken it is advisable to mix all the sub-samples in the field, remove large sticks, stones, roots, etc., and take a general sample of from three to five kilograms. The character of the débris, etc., removed should be carefully noted. It is sometimes desirable to take samples of the subsoil to a greater depth than eighteen inches. A post-hole auger or large wood auger will be found very useful for this purpose. It is rarely necessary to take samples of subsoil to a greater depth than six feet. In taking samples the geologic formation and the general topography of the field should be noted, also the character of the previous crops, kind and amount of fertilizers employed, character of drainage and any other data of a nature to give a more accurate idea of the forces which have determined the physical and chemical properties of the sample. =56. Method Of Hilgard.=—Hilgard[39] recommends that samples should not be taken indiscriminately from any locality you may chance to be interested in, but that you should consider what are the two or three chief varieties of soil which, with their intermixtures, make up the cultivable area of your region, and carefully sample these first of all. As a rule, and whenever possible, samples should be taken only from spots that have not been cultivated, or are otherwise likely to have been changed from their original condition of virgin soils and not from ground frequently trodden over such as roadsides, cattle paths, or small pastures, squirrel holes, stumps, or even the foot of trees, or spots that have been washed by rains or streams, so as to have experienced a noticeable change, and not be a fair representative of their kind. He further suggests that the normal vegetation, trees, herbs, grass, etc., should be carefully observed and recorded, and spots showing unusual growth be avoided whether in kind or quality, as such are likely to have received some animal manure or other outside addition. Specimens should be taken from more than one spot judged to be a fair representative of the soil intended to be examined as an additional guarantee of a fair average. After selecting a proper spot pull up the plants growing on it, and scrape off the surface lightly with a sharp tool to remove half-decayed vegetable matter not forming part of the soil. Dig a vertical hole, like a post-hole, at least 20 inches deep. Scrape the sides clean so as to see at what depth the change of tint occurs which marks the downward limit of the surface soil, and record it. Take at least half a bushel of the earth above this limit, and on a cloth (jute bagging should not be used for this purpose, as its fibers, etc., become intermixed with the soil) or paper break it up and mix thoroughly, and put up at least a pint of it in a sack or package for examination. This specimen will, ordinarily, constitute the soil. Should the change of color occur at a less depth than six inches the fact should be noted, but the specimen taken to that depth nevertheless, since it is the least to which rational cultures can be supposed to reach. In case the difference in the character of a shallow surface soil and its subsoil should be unusually great, as may be the case in tule or other alluvial lands or in rocky districts, a separate example of that surface soil should be taken, besides the one to the depth of six inches. Specimens of salty or alkali soils should, as a rule, be taken only toward the end of the dry season, when they will contain the maximum amount of the injurious ingredients which it may be necessary to neutralize. Whatever lies beneath the line of change, or below the minimum depth of six inches, will constitute the subsoil. Should the change of color occur at a greater depth than twelve inches the soil specimen should nevertheless be taken to the depth of twelve inches only, which is the limit of ordinary tillage; then another specimen from that depth down to the line of change, and then the subsoil specimen beneath that line. Hilgard justly calls attention to the fact that all peculiarities of the soil and subsoil, their behavior in wet and dry seasons, their location, position and every circumstance in fact, which can throw any light on their agricultural qualities or peculiarities should be carefully noted and the notes sent with the samples. Unless accompanied by such information, samples can not ordinarily be considered as justifying the amount of labor involved in their examination. =57. Whitney=[40] suggests that a geologic map of the region to be sampled should always be at hand and that all samples should be rejected from spots showing local discrepancies, washings or other disturbances. The kind of analyses to which a sample is to be subjected also largely determines the method to be pursued in selecting it: For instance, a sample to be used for determining the size of the particles therein, may be taken in quite a different manner from that designed only for the determination of moisture. =58. In= the directions collated by Richards[41] and which have been largely followed by the correspondents of the Department of Agriculture, it is recommended to select in a field, four or five places, at least, per acre, taking care that these places have an homogeneous aspect, and represent as far as possible the general character of the whole ground. If the field, however, present notable differences, either in regard to its aspect or its fertility, the samples gathered from the different parts must be kept separate. The sampling of arable soil should be made only after the raising of the crop and before it has received any new manure. In other soils the sample should be taken only from spots that have not been cultivated. =59. In= the method of soil sampling adopted by the German Experiment Stations[42] it is directed that the samples of soil should be taken according to the extent of the surface to be sampled, in three, five, nine, twelve or more places at equal distances from each other. They should be taken in perpendicular sections to the depth turned by the plow; and for some studies of the subsoil to a depth of sixty to ninety centimeters. The single samples can be either examined separately or carefully mixed and an average portion of the mixture taken. =60. Method of the Official French Commission.=—The official French commission[43] emphasizes the fact that the sample of soil taken for analysis, should represent a layer of equal thickness through the total depth of its arable part. An analysis of the subsoil taken in the same way, will often be useful to complete the data of the soil study. First of all, according to this authority, it is necessary to determine the point of view from which the sample is to be taken. If the object is a general study, having for its aim the determination of the general composition of the soils of a definite geologic formation, the sample should be taken in such a way that the different characteristics of the soil alone should enter into consideration without paying any attention to its accidental components, which have been determined by local causes, such as are produced by continued high cultivation, the application of abundant fertilizers, or the practice of a particular line of agriculture. The samples of soil therefore, with such an object in view, should be taken on parts of the earth which are beyond the reach of the causes mentioned above and which tend to modify the nature of the primitive soil. In such a case it is the soil which has not been modified, or better still, virgin soil, such as is found in the woodlands and prairies, which should be taken for a sample, choosing those places in which the geologic formation is most perfectly characterized. In such a case a soil taken in one spot corresponding to the conditions before mentioned, would be the best for the purposes in view. The sample would thus represent a true type to be studied, not one of a mean composition got by taking samples from different localities and mixing them into a homogeneous parcel. This last method of proceeding could introduce into the sample earth modified by culture or by influences purely accidental. However, it would be wise, in a region characterized by the same geologic formation, to take a certain number of samples in different localities, and examine singly each one of them in order to be assured that there is a uniformity of composition in the whole of the soils. If, on the contrary, it is the purpose of the investigation to furnish information to the cultivator concerning the fields which are worked, it is necessary to approach the problem from a different point of view. In this case the earth which is under cultivation should be first of all considered with all the modifications which nature causes or practical culture has caused, in it. But it often happens that upon the same farm the natural soil is variable, caused either by the washings from the adjacent soils, by the accumulation at certain points of deposits formed from standing water, or from other reasons. In such a case it would be necessary to take samples from every part of the field which exhibited any variation from the general type, in order to get a complete mean sample of the whole. It is necessary to be on guard against making a mixture of these different lots which would neither represent the different soils constituting the farm nor their mean composition. It would be better to examine each of these samples alone and then from those parts which appear to have a similar composition, to take a general sample for the mean analysis. Most often it is necessary to confine our studies to the really important part of the farm the composition of which would have a practical interest. The aspect of the spontaneous vegetation in such a case, will often serve as a guide to determine the parts of the farms which are similar in nature. The sample should represent the arable layer, properly so-called, that is, that part of it which is stirred by the agricultural implements in use and in which the root system of the plant takes its greatest development and which is the true reservoir of the fertilizing materials. When a trench is dug in the soil it is easy to distinguish the arable layer from the subsoil. In the first place, its color is different, generally being modified by vegetable débris which forms the supply of humus. The depth of the arable layer is variable, but it is most frequently between 200 and 300 millimeters. In the analysis the depth and layers should be indicated since the chemical composition of the earth varies according as the sample is taken to a greater or less depth. As an example of this it may be said that the quantity of nitrogen decreases in general in proportion as the depth of the layer is increased. The sample, therefore, should be limited exactly to the arable layer of soil. =61. Caldwell=[44] advises that according to the purpose of the analysis samples be taken: _a_, from one or from several spots in the field, in order to subject each sample to a separate analysis; or _b_, for an average representation of the soil of the whole field; in this case, several portions of earth are taken from points distributed in a regular manner over the field, all of which are most carefully mixed together, and 4–6 kilograms of the mixture, free from any large stones, are preserved as the average sample. An excavation in the soil 30–50 centimeters deep, or through to the subsoil, and 30–50 centimeters square, with one side as nearly vertical as possible is made and a slice taken from this side of uniform thickness throughout, weighing 4–5 kilograms. If the subsoil is to be examined, a sample of it should be taken out in the same manner as directed for the upper soil, to the depth of about 60 centimeters. If the character of the soil varies materially in different parts of the field, samples from several spots should be analyzed separately. A small portion of the sample should be put at once in a well-stoppered bottle; the remainder may be allowed to become air-dried, by exposing it in a thin layer, in summer, to the common temperature in the shade, or, in winter, to that of a warm room, or a moderately warm drying-chamber, heated to 30°–40°; in either case it should be carefully protected from dust. At the time of taking the sample of the soil, observations should be made in regard to the following points: _a._ The geognostic origin of the soil. _b._ The nature of the underlying strata, to the depth of 1–2 meters, if practicable. _c._ The meteorology of the locality, by consulting meteorological records, if possible; otherwise, by the general opinion of the neighborhood; in this connection, the height of the locality above the level of the sea should be noted also. _d._ The management and rotation of crops in previous years. _e._ The character of the customary manuring. _f._ The amount of the crops removed in the preceding year, and, if possible, the average amount of each of the more important crops yielded by the field. _g._ The practical judgment of neighboring farmers in regard to the field. Caldwel’s method is practically identical with that of Wolff[45] which was one of the earliest of the systematic schemes for taking soil samples. =62. Wahnschaffe=[46] insists on rather a fuller preliminary statement to accompany soil samples but gives essentially the method of Wolff with some unimportant variations which add little to the value of the process. =63. Method Of Peligot.=—According to Peligot[47] the taking of samples of soil of which the physical and chemical properties are to be determined is a delicate operation. These samples should represent as nearly as possible both the good and bad qualities of a soil. In the field selected are chosen a certain number of places at least four or five per hectare. The spots selected should have a homogeneous appearance—resembling as nearly as possible the general aspect of the field. By means of a spade a few kilograms of earth are removed to the depth of the subsoil being careful to include in the sample no accidental detritus which the upper part of the soil especially may contain. The samples should be taken immediately after the crop is harvested and before any fresh fertilizer is applied. The samples are carefully mixed and placed in a glass bottle or flask. The sample of subsoil is obtained in the same manner. If the field presents notable differences in surface or fertility all the samples taken should be examined separately. =64. Method of Whitney.=[48]—An ordinary wood auger, 2½ inches in diameter is so arranged as to admit of additions to the stem to enable the operator to take samples at different depths. It may be fitted with a short piece of gas pipe for a handle and the several pieces of which it is composed may be taken apart and carried in a knapsack. In taking a soil sample the boring is continued until a change in color shows that the subsoil has been reached. The auger cuts a very clean sample save in excessively sandy soil. After the soil sample is secured the hole is cleaned out and the sample of subsoil taken by the same instrument. The soil is conveniently preserved in heavy cloth bags of which the usual size is 6 by 8½ inches. Where larger samples are required the size of the bag is correspondingly increased. Each bag is to be tagged or labeled to correspond with the entry in the note book. Samples to determine the amount of empty space in a soil are taken as follows: The sampler is a piece of brass cylinder about nine inches long and about 1½ inches in diameter. A piece of clock spring is soldered in one end and sharpened to give a good cutting edge. This arrangement permits the sample to pass into the cylinder without much friction. The area enclosed by the clock spring is accurately determined and a mark is placed in the cylinder six inches from the cutting edge. The cylinder is driven into the soil to a depth of six inches, a steel cap being used to prevent the hammer from injuring the cylinder. The earth is next removed from about the cylinder with a trowel, and the separated cylinder of earth is cut smoothly off by a sharp knife and removed together with its brass envelope. The sample is taken to the laboratory in a cloth bag, dried and weighed. =65. Taking Samples for Moisture Determination.=—A number of brass tubes is provided nine inches long and ¾ inch in diameter and with a mark six inches from the bottom. The tube is pushed down into the soil to the mark and the sample of soil removed with the tube. There is but little danger of the sample dropping out of the tube even in sandy soils. When the tube is withdrawn each end is capped with a rubber finger tip making a perfectly air tight joint. The tubes containing the samples can be kept several days with no fear of losing moisture. This method is especially useful in having samples taken by observers in different localities who can enclose the tubes in a cloth sack and send them to the laboratory by mail daily or at stated intervals. A tube of the size given holds about fifty grams of soil. =66. Taking Samples to Determine the Permeability of Soil to Water or Air.=—Whitney[49] determines the permeability of soil or subsoil to water or air in the following manner: An excavation two feet square and eighteen inches deep is made in the soil. On one side of this hole the sample of soil or subsoil is taken by means of a narrow saw blade and a sharp carving knife. The sample of soil taken should be two inches square and 3½ to 4 inches long. It is placed in a brass cylinder three inches long and 3¼ inches in diameter. The open space in the cylinder is filled with paraffin heated just to its melting point. As the paraffin cools the upper surface should be kept stirred to prevent the mass when set from receding from the square column of soil. Care must be taken to keep the paraffin from the ends of the soil columns and these should be left, as far as possible in their natural condition. The rate of percolation of the water may be determined at the time the sample is taken. For this purpose an additional section of brass tube two inches deep is secured to the one holding the sample by a rubber band. An iron rod is driven into the earth carrying a retort stand ring supporting a funnel filled with fine gravel. The lower end of the soil column in the brass cylinder is placed on this gravel. Water is next carefully poured upon the top of the sample of soil being careful not to disturb the surface. The surface of the sample may be protected with a little fine sand. The water should be poured on the paraffin thus affording an additional protection to the soil surface. When the water begins to drop from the funnel a graduated glass is set under it and the time required for a given volume to pass through under an initial pressure of two inches is noted. The volume required represents one inch in depth over the four square inches of soil surface, _viz._: four cubic inches. =67. Sampling of Soil for Staple Crops.=—Some variations from the usual methods are recommended by Whitney when the samples are taken from fields growing staple crops. The immediate object of the work, for which these samples are desired, is to make a thorough study of the physical and chemical properties of a number of typical soils adapted to the different staple crops, such as grass, wheat, truck, and the different types of tobacco. They should be taken for a careful study of the texture of the soils, the relative amount and arrangement of sand and clay, the relation of the soils to moisture and heat, and the ease with which they can maintain a proper water supply for the different staple crops under existing climatic and cultural conditions. The ultimate object of such a study is to see how these conditions can be changed so as to make the soils more productive, and make them yield a better quality of crop, or to change the conditions in other soils, which differ from these, so that the culture of the different staple crops can be extended over wider areas by improved methods of cultivation and manuring. The soil selected for sampling for these investigations should be typical, should represent fairly well a considerable area of land. It should represent either the very best type of land for the staple crop or crops of the locality, or the very poorest lands for these same crops. Both of these extremes are desired for contrast. For example, if the staple crop of the locality is wheat or a certain type of tobacco, select the soil best adapted to this staple crop, and another soil, if possible, in the same locality, representing considerable area of land upon which this staple crop cannot be successfully grown on account of the inferior yield, quality, or the time of ripening of the crop. The soil sampled should be, or should recently have been, under actual cultivation in the crop or crops best adapted to it, so that the real agricultural value of the land can be accurately known. The samples should be taken inside the field, some distance away from fences, roads, or trees. If there are plants growing in the field, the sample should be taken about midway between two plants. The samples should be taken where they will typify fairly well the average soil of the field and of the large area of land which they are to represent. The samples are taken in some one of the ways described herein. Each sample should be carefully labelled at the time of taking. The following blank form will be found convenient for this purpose: │Locality: LABORATORY No.: │ ────────────────────────┼────────────────────────────────────────────── No. of sack: │Description: (virgin or cultivated). │ (_a_) Natural herbage: │ (_b_) Crops best adapted to land (grass, │ wheat, tobacco, truck, barren). │ „ ------------------------│ „ Date: │ „ │ „ ------------------------│ „ Collector: │ „ │ „ ------------------------│------------------------ Depth of sample: │ (Soil or Subsoil?) │Geologic formation: ... in. to ... inches. │ =68. Method of the Royal Agricultural Society.=[50]—Have a wooden box made, six inches long and wide, and from nine to twelve inches deep, according to the depth of soil and subsoil in the field. At one of the selected places mark out a space of twelve inches square; dig around it in a slanting direction a trench, so as to leave undisturbed a block of soil, with its subsoil, from nine to twelve inches deep; trim this block to make it fit into the wooden box, invert the open box over it, press down firmly, then pass a spade under the box and lift it up and gently turn it over. In the case of very light, sandy, and porous soils, the wooden box may be at once inverted over the soil and forced down by pressure, and then dug out. Proceed in the same way for collecting the samples from all the selected places in the field, taking care that the subsoil is not mixed with the surface soil. The former should be sampled separately. In preparing the plot for the gathering of the sample, take care to have it lightly scraped so as to remove any débris which may be accidentally found there. The different samples thus procured are emptied on a clean, boarded surface, and thoroughly mixed, so as to incorporate the different samples of the same field together. The heap is then divided into four divisions, and the opposite quarters are put aside, taking care to leave the two remaining ones undisturbed; these are thoroughly mixed together, the heap divided into quarters, and the opposite ones taken away as before. This operation of mixing, dividing into quarters and taking away the opposite quarter is continued until a sample is left weighing about ten or twelve pounds. Thus is obtained the average sample of the soil. Of course where only a single sample is taken from the field this method of quartering is not resorted to, but the bottom of the box is nailed directly on and sent to the laboratory, where the soil is to be analyzed. =69. Grandeau=[51] suggests that in taking soil samples there are two cases to be considered; first a homogeneous soil and second, a soil variable in its appearance and composition. First, if the soil is homogeneous, being of the same geologic formation it will be sufficient to take a mean sample in accordance with the following directions: The field is first divided by diagonals or by transverse lines the direction of which need not be fixed in advance but as inspection of the form and configuration of the field may indicate. In the ordinary conditions, of homogeniety (marly, granite, argillaceous or silicious soils) it will be sufficient to select about five points per hectare from which the samples are to be taken. These points having been determined the surface is cleaned in such a way as to remove from it the detritus which may accidentally cover it; such as dry leaves, fragments of wood, foreign bodies, etc. The surface having been prepared, (five to six square meters) a hole is dug four-tenths of a meter long and as wide as the spade employed. The sides should be as nearly vertical as possible. As to depth it varies with the usage of the country in regard to tillage. The layer of arable earth is what in effect properly constitutes the soil. It ought not to be mixed with any fragments of the subsoil. When the hole is properly cleaned the samples are secured with a spade from the sides of the excavations. About five kilograms are taken. The soil is placed in a proper receptacle as it is removed from the hole. This operation is repeated on as many points as may be necessary to obtain a mean sample of the soil of the whole field. All the samples are now collected on a table sufficiently large, and intimately mixed together. Two samples, each of about five kilograms, are then taken from the mixed material. One sample is immediately placed in bottles and carefully stoppered and sealed; the other is dried in the sun or on the hearth of a furnace. When sufficiently dry the second sample is also placed in bottles and well stoppered. While mixing the samples, pebbles, etc., of the size of a nut and larger are removed, the weight of the rejected matter being determined. The nature of the pebbles should also be noted; whether silicates, limestone, etc. The sample of subsoil is taken in exactly the same manner, using the same holes from which the samples of soil were taken. The nature, the arrangement and the appearance of the strata will indicate the depth to which the subsoil should be taken. In general, a depth equal to that of the sample of soil will be sufficient. The depth to which the roots of cultivated plants reach is also a good indication in taking a sample of the subsoil. In forests the sample of subsoil should be taken from four to five-tenths of a meter below the surface. If the soil in respect of its geologic formation, its fertility or its physical aspect presents great differences, special samples should be taken in each part in accordance with the directions given above. =70. Method of the Official Agricultural Chemists.=—In the directions given by the Association of Official Agricultural Chemists[52] it is stated that the soil selected should be as far as possible in its natural condition, not modified by recent applications of manure, or changed by the transporting action of water or wind. Surface accumulations of decaying leaves, etc., should be removed before taking the sample. To eliminate accidental variations in the soil, select specimens from five or six places in the field which seem to be fair averages of the soil, remove two or three pounds of the soil, taking it down to the depth of nine or ten inches[53] so as to include the whole depth. Mix these soils intimately, remove any stones, shake out all roots and foreign matter, and dry the soil until it-becomes friable.[54] Break down any lumps in a mortar with a wooden pestle, but avoid pulverizing any mineral fragments; pass eight to ten pounds of the soil through a sieve, having circular perforations one twenty-fifth of an inch in diameter, rejecting all pebbles and materials too coarse to pass through the sieve. Once more mix intimately the sifted soil. Expose in thin layers in a warm room till thoroughly air dry (or dry it in an air-bath at a temperature of 40°), place six to eight pounds in a clean bottle, with label of locality and date, and cork the bottle containing the soil, for analysis. The soil is rapidly dried to arrest nitrification; it is not heated above 40° lest there should be dissipation of ammonia compounds, or a change in solubility. The normal limit to which the soil may be heated in place by the sun’s rays should not be exceeded in preparing a sample for an agricultural chemical analysis. The relative amount of fragments too coarse to pass through the sieve should be made a matter of record. They are soil material, but not yet soil, so far as agricultural purposes are concerned. =71. Method of Lawes.=—In a late method of sampling proposed by Sir J. B. Lawes[55] a steel frame ten by twelve inches, and nine inches deep open at top and bottom is driven into the earth until its upper edge is level with the surface of the soil. All above-ground vegetation is then cut off as closely as possible with scissors. The soil within the frame is then removed exactly to the depth of the frame, and immediately weighed. It is then partially dried, and mechanically separated by a series of sieves, all visible vegetable matter being at the same time picked out. The stones and roots and the remaining soil are thus separated, and the determinations of dry matter, nitrogen, etc., are made in the separated soil after being finely powdered. The loss of water at each stage of preparation and on drying the samples as analyzed is also carefully determined. This method, which requires the soil to be taken to an arbitrary depth of nine inches, could not be used when samples of strictly arable soil are to be taken. =72. In taking= a sample by the French commission[56] method it is necessary to remove from the surface, the living and dead vegetation which covers the soil. With a spade a square hole is then dug to the depth of about 500 millimeters; in other words, to a depth considerably exceeding that of the arable layer. Afterwards on each of the four sides of the hole there is removed by the spade, a prismatic layer of the arable portion of a thickness equal to its depth. The samples thus obtained are united together and carefully mixed for the purpose of forming a sample for analysis. If there are large stones they are removed by hand and their proportion by weight determined. In all cases it would prove useful to take a sample of the subsoil which is far from playing a secondary rôle. The rootlets bury themselves deeply in it and seek there a part of their nourishment. The subsoil, therefore, furnishes an important addition to the alimentation of the plants. For taking a sample of the subsoil a ditch is dug of sufficient depth, say one meter, and the arable soil carefully removed from the top portion. Afterwards pieces are taken from the four sides of the hole at variable depths, which should always be indicated, and which should extend in general, from six to eight-tenths of a meter below the arable soil since it is demonstrated that the roots of nearly all plants go at least to this depth. The analysis of the subsoil, however, is less important than that of the soil, properly so-called, because the agronomist does not act directly upon it and takes no thought of modifying it and enriching it as he does the layer of arable soil. But the composition of the subsoil is a source of information capable of explaining certain cultural results and capable sometimes, of leading to the correct way of improving the soil, as in cases where the subsoil can be advantageously mixed with the superficial layer. =73. Wolff=[57] suggests that a hole thirty centimeters square be dug perpendicularly and a section from one of the sides taken for the sample. To the depth of thirty centimeters the sample shall be taken as soil and to the additional depth of thirty centimeters as subsoil. The thickness of the section taken may vary according to the quantity of the sample desired. For analytical purposes, five kilograms will usually be sufficient. When culture experiments are also contemplated a larger quantity will be required. =74. Method of Wahnschaffe.=—The method of sampling advised by Wahnschaffe[58] is but little different from that of Wolff already mentioned. A square sample hole is dug with a spade having its sides perpendicular to the horizon. The soil which is removed is thrown on a cloth and carefully mixed. From the whole mass a convenient amount is next removed care being taken not to include any roots. In a similar manner it is directed to proceed for the sample of subsoil. At first the subsoil should be removed to a depth of two to three decimeters. The number and depth of subsequent samples will depend chiefly upon the character of the soil. Where samples are taken to the depth of two meters the use of a post-hole auger is recommended. The samples taken should not be too small. In general from two to three kilograms should remain after all preliminary sampling is finished. =75. Method of König.=—The directions given by König[59] for taking soil samples are almost identical with those prescribed by Wahnschaffe and do not require any further illustration. =76. Special Instruments Employed in Taking Samples.=—In general a sharp spade or post-hole auger is quite sufficient for all ordinary sampling but for certain special purposes other apparatus may be used. The instrument which is used by King[60] consists of a thin metal tube of a size and length suited to the special object in view, provided with a point which enables it to cut a core of soil smaller than the internal bore of the tube and at the same time make a hole in the ground larger than its outside diameter. Its construction is shown in figure 11, in which A B represent a soil tube intended to take samples down to a depth of four feet. A′ is a cross-section of the cutting end of the tube, which is made by soldering a heavy tin collar, about three inches wide, to the outside of a large tube allowing its lower end to project about one-half an inch. Into this collar a second one is soldered with one edge projecting about one-quarter of an inch and the other abutting directly against the end of the soil tube. Still inside of this collar is a third about one-half an inch wide which projects beyond the second and forms the cutting edge of the instrument. FIGURE 11. ] The construction of the head of the tube is shown at B′. It is formed by turning a flange on the upper end of the tube and then wrapping it closely with thick wire for a distance of about three inches, the wire being securely fixed by soldering. The soil tube should be of as light weight as possible not to buckle when being forced into the ground, and the cutting edge thin. The brass tubing used by gas fitters in covering their pipes has been found very satisfactory for ordinary sampling. With a one inch soil tube four feet long it is possible to get a clear continuous sample of soil to that depth by simply forcing the tube into the ground with the hand and withdrawing it, or the sample may be taken in sections of any intermediate length. Later in the season when the soil becomes dryer it is necessary to use a heavy wooden mallet to force the tube, and this should be done with light blows. The closeness with which it is possible to duplicate the samples in weight by this method will be seen below, where from each of four localities three samples were taken from the surface to a depth of four feet. SHOWING VARIATIONS IN THE DRY WEIGHT OF TRIPLICATE SAMPLES OF SOIL. ─────────────────────────┬──────────┬──────────┬────────── │ A. │ B. │ C. ─────────────────────────┼──────────┼──────────┼────────── I. Surface to four feet│716.6 gms.│715.5 gms.│710.3 gms. II. Surface to four feet│715.4 gms.│687.1 gms.│731.2 gms. III. Surface to four feet│654.0 gms.│688.3 gms.│709.0 gms. IV. Surface to four feet│714.0 gms.│687.8 gms.│719.3 gms. These four series of samples were taken at the four corners of a square twelve feet on a side and serve to show how much samples may vary in that distance. The large difference shown in III, A is due to the fact that the soil tube penetrated a hole left by the decay of a rather large root as shown by the bark in the sample. =77. Auger for Taking Samples.=—It has already been said that the ordinary auger used for boring fence post-holes may be used to advantage in taking soil samples. Large wood augers can also be used to advantage for the same purpose. For special purposes, however, other forms of augers may be used. Norwacki and Borchardt[61] have described a new auger for taking samples of soil for analytical purposes. FIGURE 12. ] In figure 12, A, B and C show the general exterior and interior form of the instrument. The handle is hollow and made of iron gas pipe covered with leather. On the inside of this, in the middle, is fixed a wooden plug a, which leaves two compartments, one in each end for holding the brass plug bb,’ and the wicker lubricating wad cc.’ The stem of the auger a, is heavy and made of eight-sided steel and the under end is strengthened with a heavy casting fitting into the auger guide g g. The end of the auger I I′ is triangular and hardened. The auger guide g g, is made out of a single piece of drawn steel tubing. Above it is strengthened by a ring-shaped piece of iron or copper and its lower end is furnished with saw teeth as shown in K and is hardened. The fixing key e, is bent in the form of a hook and can be passed through the two holes o o, of the auger stem and through the one hole o′ in the strengthened part of the auger guide. It permits the auger guide to be fixed upon the auger stem in two different positions, higher and lower. On one end it is cut squarely across and on the other provided with a conical hole drilled into it. It fits on the one hand exactly in the auger guide and on the other loosely plays in the cavity of the handle at b, designed to hold it when not in use. The cap d′ is made of heavy sheet brass and is fastened upon the end of the handle at c c′ after the manner of a bayonet. The wicker cartridge is made of rolled and sewed wicker-work. At the upper end it is provided with a metallic button and before use it is saturated with paraffin oil. It fits on the one side firmly in the auger guide and on the other in the cavity, of the handle c where it is kept when not in use. The union h is made of a brass tube which below is closed with a piece of solid brass upon the inside of which a hole is bored. In this hole rests the end of the auger stem when the union is placed firmly upon the auger guide. The auger is placed together as is shown in A B, the union h is taken off and it is driven with gentle blows, turning it back and forth, to the proper depth into the soil. After the key is loosened the auger is lifted high enough so that the second hole appears and then it is fixed in position by the key. Then the boring is continued, turning the auger to the right, by which the auger, eating its way with its saw teeth, presses deeper into the ground and withdraws the material for analysis. After the auger guide has been filled through any desired length, say five to ten centimeters with the sample of soil, the whole auger is drawn out of the soil, the key removed, the auger stem withdrawn from the auger guide, the apparatus opened by turning the bayonet fastening of the stopper on the handle, the brass plug placed in the end and then with the smooth part forward, from above, it is allowed to fall into the auger guide until it reaches the soil. The auger stem is then put back, the point of it fitting into the hole of the plug and the sample of soil shoved out of the auger guide. The auger guide is again fixed on the auger stem by the key and then the apparatus is ready for a second operation. When the borings cease the wicker cartridge is drawn out of the handle and shoved, the soft end forward, from above, into the auger guide and the brass plug after it and pushed through with the auger stem. By this process the wicker cartridge gives up a sufficient amount of paraffin oil to completely grease the inside of the auger guide and to protect it from rust. After use the instrument should be cleaned on the outside by means of a cloth, the plug and wicker wad replaced in their proper positions, the cap fixed on the handle and the union on the point of the instrument. The length of the whole apparatus may reach one meter or more; the internal diameter sixteen millimeters. The apparatus weighs with a length of one meter, together with all its belongings, about two kilograms. For the investigation of peat and muck soils as well as sand, instead of the steel auger guide one of brass or copper can be used. For this purpose the length of the apparatus may reach three to four meters. In comparison with other apparatus which are used for taking samples, it appears without doubt that with the one just described a better and less mixed portion of the soil can be obtained at great depths. The apparatus is said to have many advantages over a similar one known as Fraenkel’s, and is much more easy to clean. The advantages of the apparatus are said to be the following: The farmer with this piece of apparatus in a short time can go over his whole farm taking samples to the depth of ninety centimeters since a single boring does not take more than one minute. Geologists and others interested in the soil at greater depths can use an apparatus three to four meters in length and obtain unmixed samples from these lower depths. These are also interesting from a bacteriologic point of view. The entire apparatus is especially valuable for the investigation of the lower parts of peat and muck soils. The apparatus has been tried in the collection of samples for the laboratory of the Department of Agriculture and is too complicated to be recommended for ordinary use. When however samples are to be taken at great depths as in peat soils it is highly satisfactory. =78. Soil Sampling= depends for its success more on the judgment and knowledge of the collector than on the method employed and the apparatus used. One skilled in the art and having correct knowledge of the purpose of the work will be able to get a fair sample with a splinter or a jack-knife while another with the most elaborate outfit might fail entirely in collecting anything of representative value. There are some special kinds of soil sampling, however, which cannot be left to the method of the individual and it is believed that with the descriptions given above nearly all purposes for which samples are desired may be served. For the study of nitrifying organisms, however, special precautions are required and these will be noted in a more appropriate place. In taking samples for moisture determinations the method of Whitney is recommended as the best. For the general physical and chemical analytical work the standard methods are all essentially the same. The principles laid down by Hilgard will be found a sufficient guide in most cases. TREATMENT OF SAMPLE IN THE LABORATORY. =79. The Sample=, or mixed sample, taken by one of the methods above described, is placed on a hard smooth board, broken up by gentle pressure into as fine particles as possible and all pieces of stone and gravel carefully removed and weighed; all roots, particles of vegetable matter, worms, etc., are also to be weighed and thrown out. This can be done very well by using a sieve of from one to two millimeter mesh. Care should be taken that the soil be made to pass through, which can be accomplished by subjecting the lumps to renewed pressure with a rubber-tipped pestle. In the above operation the soil should be dry enough to prevent sticking. The relative weights of the pebbles, roots, etc., and the soil should be determined. =80. Order of Preliminary Examination.=—Hilgard[62] commences the examination of a soil sample by washing about ten grams of it into a beaker with a water current of definite velocity, stirring meanwhile actively the part carried into the vessel. The residue not carried by the current is examined macro- and microscopically to determine the minerals which may be present, and the condition in which the fragments exist—whether sharp or rounded edges, etc. This examination will give some general idea of the parent rocks from which the sample has been derived and of the distance the particles have been transported. Next follows the hand test, _viz._, rubbing the soil between the thumb and fingers first in the dry state and afterwards kneading it with water and observing its plasticity. Following this should come a test of the relations of the sample to water, _viz._, its capacity for absorbing and retaining moisture. Finally the separation of the soil into particles of definite hydraulic value and a chemical examination of the different classes of soil concludes the analytical work. =81. Air Drying.=—The sifted soil should be thoroughly mixed and about one kilogram spread on paper and left for several days exposed in a room with free circulation of air and without artificial heat. The part of the sample to be used for the determination of nitrates should be dried more quickly as described in another place. The sample is then placed in a clean, dry glass bottle, corked, sealed, and labeled. The label or note book should indicate the locality where the sample was taken, the kind of soil, the number of places sampled, and other information necessary to proper description and identification. =82. Caldwell=[63] directs that having taken the sample to the laboratory, the stones and larger pebbles should be separated from the finer parts by the hand, or by sifting with a very coarse sieve, and examined with reference to their mineralogical character, weight and size, making note, in this last respect, of the number that are as large as the fist or larger, the number as large as an egg, a walnut, hazel-nut, and pea, or give the percentage of each by weight. Pulverize the air-dried soil in a mortar with a wooden pestle, and separate the fine earth by a sieve with meshes three millimeters wide; this sieve should have a tightly fitting cover of sheepskin stretched over a loop, and it should be covered in the same manner underneath, so that no dust can escape during the process of sifting. Wash the pebbles and vegetable fibers remaining on the sieve with water, dry and weigh the residue; the water with which this gravel was washed should be evaporated to dryness at a temperature not exceeding 50° towards the close of the evaporation, and the residue mixed with what passed through the dry sieve. The sifted fine earth is reserved for all the processes hereinafter described, and is kept in well-stoppered bottles, marked air-dried fine earth. The sieve mentioned above is too coarse for the more modern methods of analysis. =83. Wolff=[64] directs that the air-dried earth (in summer dried in thin layers at room temperature, in winter in ovens at 30° to 50°) be freed from all stones, the latter washed, dried, and weighed. The soil is next passed through a three millimeter mesh sieve, the residual pebbles and fiber washed, dried and weighed. The fine earth passing the sieve is used for all subsequent examinations. It is air-dried at moderate temperatures and preserved in stoppered glass vessels. =84. The French=[65] commission calls especial attention to the method of subsampling, and prescribes that the sample of earth which has been taken in the manner indicated, and of which the weight should be greater as the material is less homogeneous should not be analyzed as a whole. It should be divided into two parts. The first includes the finer particles constituting the earth, properly so-called, with the elements which alone enter into play in vegetable nutrition and on which it is necessary to carry out the analysis. The second embraces the coarser particles to which only a superficial examination should be given and which may have a certain importance from a physical point of view but which cannot take any part from a chemical point of view, in the nutrition of plants. It is, however, useful to examine its mineralogical constitution and to look for the useful elements such as lime, potash, etc., which it may be able to furnish to the earth, and in proportion as it is decomposed, finer particles which may be useful in plant nutrition. How are we to distinguish between the fine and coarse elements? All grades of fineness are observed in the soil, from the particles of hydrated silica so small that with the largest magnifying power of the microscope it is scarcely possible to distinguish them, up to grains of sand which are of palpable size and visible to the naked eye, and extending to pebbles of varying sizes. All intermediate stages are found between these and if it should be asked what is the precise limit at which it is necessary to stop in distinguishing the fine from the coarse elements of the soil, the answer is that this can only be determined by a common understanding among analysts. In general, it may be said, that the mark of distinction should be the separation which can be secured with a sieve having ten meshes per centimeter. =85. Loose Soils.=—Having agreed upon a sieve of the above size, the process of separation in loose soils is as follows: The earth is exposed to the air and when the touch shows that it is sufficiently dry the conglomerated particles should be simply divided without breaking the rocky material which exists in a state of undivided fragments. There are some special precautions to be taken. Rubbing in a mortar must be forbidden since it reduces the earth to particles which are unnatural in size, by securing the breaking up of the fragments consisting of the débris of rocks. When it is possible the earth should be rubbed simply in the hand and after having separated that which passes the sieve, the large particles which have not passed should be again rubbed with the hand, until all the particles which can be loosened by this simple treatment have passed the sieve. The separation should be as complete as possible in order that a sample of the particles passing the sieve should represent as nearly as possible, a correct sample of the fine particles of the soil. In regard to the pebbles, they should be washed with water upon the sieve in order to carry through the last of the particles of earth adhering to them. They are then dried and their weight taken. The fine part of the earth is also weighed. On an aliquot part, say 100 grams, the moisture is determined and then by simple calculation the whole sample of the air-dry soil can be calculated to the dry state. The sample is then placed in a glass flask. The pebbles are examined with a view of determining their mineralogical constitution; as for instance, on being touched with a little hydrochloric acid it can be determined whether or not they are carbonate of lime. The nature of the rock from which they have been derived is often to be determined by a simple inspection. =86. Compact Soils.=—If the soils are not sufficiently loose to be treated as before described, it is necessary to have recourse to other means of division, which should not, however, be sufficiently energetic to reduce the rocky elements to fine particles. For this purpose the earth may be broken by means of a wooden mallet, striking it lightly and separating the fine elements from time to time by sifting. A wooden roller may also be used with a little pressure, for breaking up the particles or a roller made out of a large glass bottle. These methods will permit of a sufficiently fine division of the soil without breaking up any of the pebbles. Sometimes, however, a soil can not be broken up by such treatment. It is then necessary to have recourse to the following process: The soil is thoroughly moistened and afterwards rubbed up with water. The paste which is thus formed, is poured upon the sieve and washed with a stream of water until all the fine particles are removed. The wash water and the fine particles are left standing until the silt is thoroughly deposited when the supernatant water is poured off and the deposited moist earth is transferred into a large dish and dried on a sand or water-bath. In this way a firm paste is formed which can be worked up with the hand until rendered homogeneous and afterwards an aliquot portion be taken to determine moisture. =87. Method of Peligot.=—The method recommended by Peligot[66] for the preparatory treatment of the sample is essentially that already described. The sample is at first dried in the air and then in an oven at 120°. When dry and friable 100 grams are placed in a mortar and rubbed with a wooden pestle. It is then passed through a sieve of ten meshes per centimeter. The largest particles which remain in the sieve should have about the dimensions of a pin’s head. The stones are separated by hand. They should be shaken with water in order to detach any pulverulent particles adhering thereto. The turbid water resulting from this treatment is added to that which is used in separating the sand from the impalpable part of the soil. =88. Wahnschaffe= prescribes[67] in the further preparation of the sample for analysis that the coarse pieces up to the size of a walnut be separated in the field where the sample is taken and their relative weight and mineralogical character determined. The soil sample is then to be placed in linen or strong paper bags and carefully labelled. In order to avoid any danger of loss of label the description or number of the sample should be put on the cloth or paper directly. The sample when brought to the laboratory should be spread out to dry, in a room free of dust. In the winter the room should be heated to the usual temperature. The air drying should continue until there is no sensible loss of weight. The samples then are to be placed in dry, glass-stoppered glass bottles where they are kept until ready for examination. This method of keeping the samples avoids contact with ammonia or acid fumes with which a laboratory is often contaminated. =89. The Swedish= chemists[68] direct that samples which are to be used for chemical examination in the manner described below, are most conveniently brought to such a condition of looseness and humidity that the soil feels moist when pressed between the fingers without, however, sticking to the skin. To prepare the sample in this manner, spread it in a large porcelain dish or on a glass plate in a place where it is not reached by the laboratory atmosphere; stir it frequently till it assumes the mentioned humidity (if the sample when sent is too dry, moisten it with distilled water till its condition is as indicated); then pulverize carefully between the fingers and finally sift through a sieve with five millimeter holes. In this way free the sample from stones, undecayed roots and similar parts of plants, pieces of wood, and other matter strange to the soil, which remain on the sieve; mix the sample carefully and put it into a glass bottle provided with a stopper well ground in; keep it in a cool place. Samples prepared in this way will usually contain 20–30 per cent moisture; boggy soils 60–80 per cent and peat soils 50 per cent. =90. Petermann=[69] follows the method below in preparing samples of soil for analysis. The soil is gently broken up by a soft pestle and all débris if of organic nature, cut fine with scissors. About 2500 grams of this soil are passed through a one millimeter mesh sieve. The organic débris is removed by forceps, washed free of adhering earth dried at 120° and weighed. The nature of the organic débris should be noted as carefully as possible. The pebbles and mineral débris not passing the sieve are worked in a large quantity of water by decantation. They are also dried at 120° and weighed. This débris is examined mineralogically and thus some idea of the origin of the soil obtained. =91. The= various methods for the preliminary treatment as practiced by the best authorities have been somewhat fully set forth in the foregoing résumé. The common object of all these procedures is to get the soil into a proper shape for further physical and chemical examination and to determine the comparative weights of foreign bodies contained therein. The essential conditions to be observed are the proper sifting of the material and avoidance of mechanical communition of the solid particles too large to pass the meshes of the sieve. If possible the material should be passed through a sieve of one millimeter mesh. In cases where this is impracticable a larger mesh may be used, but as small as will secure the necessary separation. Before final chemical analysis a half millimeter mesh sieve should be employed if the soil be of a nature which will permit its use. Over-heating of the sample should be avoided. Rapid drying is advisable when the samples are to be examined for nitrates. The method recommended by the French commissions seems well adapted to the general treatment of samples, but the analyst must be guided by circumstances in any particular soil. AUTHORITIES CITED IN PART SECOND. Footnote 39: Bulletin 38, pp. 61–2. Footnote 40: Ms. communication to author. Footnote 41: Bulletin No. 10. Footnote 42: Landwirtschaftliche Versuchs-Stationen, Band 38, Ss. 309 et seq. Footnote 43: Annales de la Science Agronomique, Tome 1, Part 2, p. 240. Footnote 44: Agricultural Chemical Analysis, p. 166. Footnote 45: Zeitschrift für analytische Chemie, Band 3, S. 87. Footnote 46: Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 17. Footnote 47: Traité de Chimie Analytique, p. 149. Footnote 48: Bulletin 35, p. 108. Footnote 49: Op. cit. Footnote 50: Bulletin 10, p. 33. Footnote 51: Analyse des Matières Agricoles, p. 131. Footnote 52: Bulletin 38, p. 200. Footnote 53: This in some instances would include a part of the subsoil. Footnote 54: All soils do not become friable on drying. Footnote 55: Journal of the Royal Agricultural Society, (2), Vol. 25, p. 12. Footnote 56: Annales de la Science Agronomique, Tome 1, Part Second, pp. 240 et seq. The personnel of the commission is as follows: MM. Risler, Grandeau, Joulie, Schloesing, and Müntz. Footnote 57: Vid. 7. Footnote 58: Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 17. Footnote 59: Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, S. 5. Footnote 60: Seventh Annual Report of the Wisconsin Agricultural Experiment Station, p. 161. Footnote 61: Deutsche Landwirtschaftliche Presse, Band 19, No. 35, Ss. 383–4. Footnote 62: Journal American Chemical Society, Vol. 16, p. 36. Footnote 63: Agricultural Chemical Analysis, p. 168. Footnote 64: Vid. 7. Footnote 65: Vid. 16. Footnote 66: Vid. 9. Footnote 67: Vid. 8, p. 19. Footnote 68: Methods of Analysis of Soils, Fertilizers, etc., adopted by the Swedish Agricultural Chemists, translated for the author by F. W. Woll. Footnote 69: L’Analyse du Sol, p. 14. PART THIRD. PHYSICAL PROPERTIES OF SOILS. =92. The Soil as a Mass.=—The soil constituted as indicated in the preceding pages, is now brought to the analyst for investigation. The properties with which he first becomes acquainted are those which impress his senses as mass characteristics. There is a perception of color, consistence, weight and other features which the soil possesses as a whole. The several constituents of the soil must first be considered as molecular and mole aggregates. In other words, the soil in its natural state is a mechanical mixture of particles which must first be considered as a whole. The physical properties of the soil, therefore, should engage the attention of the analyst before he proceeds to the investigation of the properties of its several constituents as classified by the relative size or hydraulic value of the particles of which they are composed, or to a chemical determination of the compounds or elements therein contained. DETERMINATION OF PHYSICAL PROPERTIES. =93. Color.=—The color of a soil depends chiefly upon the proportion of organic matter and iron compounds which it contains and the state of subdivision of its particles. When a soil contains a large amount of organic matter, especially when this organic matter is in an advanced state of decay, it assumes more or less a black color when moist. This black color is to be distinguished from the black alkali tint which is produced by the action of carbonate of soda on organic matter. The naturally black color of a soil containing a large amount of organic matter depends, however, either upon the action of mineral matters upon this organic matter, as in the case of the black alkali mentioned, or upon the blackish color of carbon resulting from the slow combustion of the organic matter during the period of decay. The presence of a large amount of ferric oxid in soil gives the well-known red color so well-marked in the soils of southwestern Kentucky and other portions of the United States. The preponderance of sand in a soil tends to produce a light yellow or whitish tint, while certain kinds of clay have a bluish tint probably due to the presence of ferrous salts. The influence of the color of the soil upon the color of the vegetation is also well-marked, the black soils as a rule producing a much deeper green tint of foliage than the light colored soils. This effect should not be attributed to color alone for as a matter of fact highly colored soils are usually very close and very retentive of moisture, which is one reason, probably, for their not being more highly oxidized. Such soils will produce a more vigorous and ranker growth of vegetation, but it is the texture of the soil and the more moist condition which it maintains, rather than the color, which produce the deeper green tint of foliage. The color of a soil is also used as an index of its fertility, the black and red soils being usually the most fertile. It may be well to add here the probable reason as given by Whitney for this, _viz._, that the deeper color shows that the oxids of iron and the organic compounds have less oxygen and indicate that the soils are quite retentive of moisture and rather tend to the exclusion of air, so that part of the oxygen of the iron compounds and of the organic matters has been used up in the oxidation processes within the soil. It is known, for example, that wood oxidizes much more rapidly around a rusty nail than where it is simply exposed to the air, the iron oxid acting as a carrier between the oxygen of the air and the organic matter. In a sandy soil, on the contrary, where there is usually less moisture and much freer circulation of air, the iron compounds have more oxygen and usually have a light yellow color. If this sand is heated, however, with the exclusion of air, and especially in the presence of organic matters, part of this oxygen will be given off and there will be the same red color as in the heavier clay soils. It is frequently noticed, also, in compact clays that where air gains access through cracks or root-holes, the color is altogether modified. =94. Determination of Color.=—There is no process which will give experimentally and accurately the color of a soil sample. The changes which the color of a soil undergoes in passing from a saturated to an anhydrous state are well-marked. The analyst will have to be content with giving as nearly as possible a description of the color of the sample when taken and the changes which it undergoes in air drying or on heating in a bath to 100°–110°, or in heating to redness with or without exclusion of the air. These changes in color will give some indication of the character of the organic and mineral matters present. =95. Odoriferous Matters in Soil.=—It is known that the soil emits a peculiar odor which is not disagreeable except when it has been recently wet, for instance, after a short rain. Several attempts have been made to discover the nature of this odor. These researches have established the fact that the essential principle of this odor resides in an organic compound of a neutral nature of the aromatic family and which is carried by the vapor of water after the manner of a body possessing a feeble tension. The odor is penetrating, almost piquant, and analogous to that of camphorated and quite distinct from other known substances. In regard to the quantity of this substance, it is extremely minute and can be regarded as being only a few millionths of a per cent. According to Berthelot and André[70] this new principle is neither an acid nor an alkali nor even a normal aldehyd. It is, in a concentrated aqueous solution, precipitable by potassium carbonate with the production of a resinous substance. Heated with potash it develops a sharp odor similar to the aldehyde resin. It does not reduce the ammoniacal nitrate of silver. Treated with potash and iodin it gives an abundant formation of iodoform, which, however, is a property common to a great number of substances. For the qualitative and quantitative estimation of the odoriferous matter the following process is employed: About three kilograms of the soil are mixed with sand containing a small amount of carbonate of lime and some humic substance; after having freed it from all organic débris which is visible, it is placed in a glass alembic. The soil should contain from ten to twelve per cent of water at least. The alembic is placed in a sand bath and is kept at 60° for several hours. The water evaporated is condensed until about seventy-five cubic centimeters are distilled over. This distilled water is again rectified so as to obtain in all about twenty cubic centimeters. The odoriferous matter appears to be nearly all contained in this twenty cubic centimeters. The liquid thus obtained shows an alkaline reaction; it contains some ammonia and reduces ammoniacal silver nitrate. This last reaction is due to some pyridic alkali or analogue thereof, and is cause for it to be distilled anew with a trace of sulfuric acid which gives a neutral liquor deprived of all reducing action but which preserves the odor peculiar to the soil. The twenty cubic centimeters obtained as before are subjected to two additional distillations and in the final one only one cubic centimeter of liquid is distilled over. The peculiar odor is intensified proportionately as the volume of the liquid is decreased. To this one cubic centimeter, is added some pure crystallized potassium carbonate. The liquor is immediately troubled and some hours are required for it to become clear again. Meanwhile there is formed upon its surface a resinous ring almost invisible, amounting at most to from ten to twenty milligrams of a matter which has not been identified with any known principle. The reactions described above, however, permit of its general character being known. This resinous matter contains the odoriferous principle, the composition of which is not yet definitely known. =96. Specific Gravity.=—The density of a soil depends on its composition, the fineness of its particles and upon the packing which it has received. It has in other words an apparent and a real specific gravity. It is easy to see that a soil in good tilth would weigh less per cubic foot than one which had been pressed closely together, as in a road or well-pastured field. Ordinary soils in good tilth have an apparent specific gravity of about 1.2, and when entirely free from air, a real specific gravity of about 2.5. If the apparent specific gravity of a soil sample were 1.2 and the air were removed, leaving a vacuum in the interstices of the soil, the apparent specific gravity would not be sensibly increased. The figure 1.2 is the apparent specific gravity of a mixture of soil material which is about 2½ times heavier than water, and of an extremely small proportion by weight of air which is about 1000 times lighter than water. The figure 2.5 is about the true specific gravity of the real soil material, and shows that this material is about 2½ times heavier than an equal volume of water. The weights of a cubic foot of different kinds of soil as given by Schübler[71] are as follows; Pounds. Sand 110 Sand and clay 96 Common arable soil 80 to 90 Heavy clay 75 Vegetable mold 78 Peat 30 to 50 In general the specific gravity of soil decreases inversely as its content of humus. =97. Determination of Specific Gravity.=—The ordinary method of proceeding to determine the true specific gravity is by means of a pyknometer. The pyknometer should have a capacity of from twenty-five to fifty cubic centimeters. From ten to fifteen grams of earth dried to constant weight at 100° are taken, boiled for a time with a few cubic centimeters of water to remove air and poured into the pyknometer. All soil particles are washed out of the vessel in which the boiling took place into the pyknometer with freshly boiled distilled water and after cooling to the temperature at which the calibration took place, the pyknometer is filled with distilled water at the given temperature and weighed. If the soil contain materials soluble in water, alcohol of definitely known specific gravity may be employed and the number thus obtained calculated to a water basis. The calculations when water is used are made as follows: Grams. Weight of pyknometer 13.4789 „ „ pyknometer full of distilled water at 20° 62.8934 „ „ water in pyknometer 49.4145 „ „ dry soil taken 10.0000 „ „ pyknometer + dry soil + filled with water at 20° 67.9834 „ „ soil and water 54.5045 „ „ water 44.5045 „ „ water displaced by ten grams soil 4.9100 Then specific gravity = 10.000 ÷ 4.9100 = 2.04. =98. Specific Gravity of Undried Soils.=—It is often desirable to determine the specific gravity of an undried portion of the soil. For this purpose a portion of the sample is dried at 100° to determine its percentage of moisture. The specific gravity is then determined on a ten gram sample of the undried soil as just given. The actual weight of soil taken is calculated from the percentage of moisture obtained in the first instance. In the case given if the percentage of moisture at 100° be ten then the actual weight of dry soil taken is nine grams. This number is therefore used in making the calculations. In all statements of specific gravity taken in the manner described the temperature at which the pyknometer is calibrated should be stated and all weighings where water is involved made at that degree. =99. Volume of Soil.=—If it be desired to calculate the volume occupied by a soil it is easily done by dividing the weight of water displaced by the weight of one cubic centimeter of water of the temperature at which the determination took place. In the case given one cubic centimeter of water at 20° weighs 0.998259. Then 4.9100 ÷ 0.998259 = 4.9186 cubic centimeters = volume occupied by ten grams of dry soil excluding interstitial spaces between particles. =100. Volumetric Methods.=—The water displaced by a given weight of soil may also be measured volumetrically by the method of Knop.[72] Place 200 grams of the soil in a flask of from three to five hundred cubic centimeters capacity. Add a measured quantity of water, and shake thoroughly to eliminate air, and fill up to the mark from a burette. The quantity of water required to complete the volume subtracted from the number expressing the volume of the flask will give the volume of water displaced by the earth. Another method consists in thoroughly shaking about thirty grams of the soil in a graduated cylinder with fifty cubic centimeters of water containing a little ammonium chlorid and after twenty-four hours recording the volume occupied by the whole. The increase in volume over fifty cubic centimeters shows the quantity of water displaced. This method may also be used to determine the volume occupied by a soil when saturated with water. The above methods are only to be used when approximately correct results are all that are desired. =101. Apparent Specific Gravity.=—The apparent specific gravity of a soil is obtained by dividing its volume, interstitial spaces included, by the weight of an equal volume of water. The real and apparent specific gravities of six samples of soil are given below.[73] Real specific gravity 2.5445, 2.6315, 2.6508, 2.6400, 2.7325, 2.6603 Apparent specific gravity of air-dried soil 1.0940, 1.1710, 1.3570, 1.2810, 1.4060, 1.2730 Apparent specific gravity of soil dried at 125° 1.0990, 1.1770, 1.3750, 1.2910, 1.4640, 1.2850 It is to be noted that in computing the apparent specific gravity of a soil dried at 125° the volume occupied by the water is assumed to occupy the same space as if it existed in a free state. The volume of this water is therefore to be subtracted from the contents of the flask before proceeding with the computations. =102. Determination of Apparent Specific Gravity.=—Place in small quantity portions of the air-dried sample properly prepared, into an open glass cylinder, holding one liter, and about 170 millimeters high (if the height is exactly the mentioned one, the diameter of the cylinder will be 86.6 millimeters); pack the sample by striking the bottom of the cylinder hard against the palm of the hand after each new filling; close the cylinder thus filled by a glass plate and weigh on a balance sensitive to 0.1 gram; deduct the weight of the cylinder and glass plate, and the weight of one liter of soil in approximately similar conditions as it is found on the dry land prepared for cultivation, is thus ascertained. The weight of one liter of the soil in grams multiplied by 2000 will give in kilograms the weight of the surface soil from a hectare (2.47 acres) of the field from which the sample is taken when the depth of this is calculated at twenty centimeters.[74] RELATION OF THE SOIL TO HEAT. =103. Sources of Soil Heat.=—The heat of the soil comes from three sources, _viz._: solar heat, as the sun’s rays, heat of chemical and vital action within the soil, and the original heat of the earth’s interior. The latter is sensibly a constant quantity, and of great value to plants. The heat of chemical and vital action is not great in amount except in a few special cases but is often, as in germination, of the greatest importance to plant growth. The sun, therefore, remains the greatest source of heat of practical importance in relation to the production of crops. Dark-colored soils, absorbing most and radiating the fewest rays, must attain the highest temperature. Schübler’s classical researches on soil temperatures, show that there is at times a difference of over 7° in temperature between white and black soils, all other conditions being alike. Schübler’s researches, being made on dry soils in the laboratory, do not, however, apply wholly to conditions in the field. =104. Influence of Specific Heat.=—The heat which a soil receives and retains is largely due to the specific heat of the soil. The specific heat of a body is expressed by a number which shows the amount of heat necessary to raise a given weight of the body 1° of temperature, as compared with the amount necessary to raise the same weight of water 1°. The specific heat of the soil is usually between 0.20 and 0.25, while that of water taken as the standard is unity. =105. Influence of Moisture.=—The moisture of the soil possesses great influence on the soil temperature, so much so that a dry, light-colored soil may attain a greater degree of warmth than a moist, dark-colored one. The action of water in reducing soil temperature is easily explained. In our latitude, we see the water in all its forms, solid, liquid, and gaseous, and we know that these forms are the direct result of temperature. The changing of water from the solid to the liquid or gaseous form is performed at the expense of heat; the more water evaporated from the soil the more heat must be used for the evaporation. Therefore, the more water contained in the soil at any given time the lower must be its temperature during subsequent exposure to sun heat because of the greater evaporation. The experiments of Liebenberg, Pattner, Schübler and Dickenson have practically settled all the questions of soil temperatures. The radiation of heat from the soil, and the consequent cooling propensity of the latter, are directly proportional to the absorptive power of the soil. Two soils of like absorptive power towards heat possess, as a rule, equal radiating power. In a general way, it can be said the greater the heating capacity and conductivity of a soil the more readily and rapidly does it give off its heat and become cooled. =106. Absorption of Solar Heat.=—The quantity of heat absorbed from the sun by the earth is an important factor in the growth of vegetation. As has been established in the physics of heat, a black surface, other things being equal, will absorb a larger amount of heat than one of any other color; so, other things being equal in the physical and chemical composition of a soil, variations in the amount of organic matter producing greater or less black coloration will affect the heat absorption. Thus, black soils, in the conditions above mentioned, will absorb more heat than lighter colored soils. As a result, the vegetation in such soils gets an earlier start in the Spring and matures more rapidly. As an illustration of this it may be noted that the black prairie soils of Iowa produce uniformly crops of maize which are matured before the early frosts, while crops grown on lighter soils much farther South often suffer injury from that source. DETERMINATION OF SPECIFIC HEAT. =107. General Principles.=—The quantity of heat stored in any given weight of soil is capable of being measured and compared with the quantity stored in an equal weight of water at the same temperature. The ease, however, with which disturbing influences operate during the determination makes the manipulation somewhat difficult. The specific heat of the containing vessels must be carefully determined. Fortunately this has been done for most materials and the data thus obtained are recorded in standard works on physics. The material operated on must be protected from thermal influences from sources not controlled by the experiment and even the heat of the operator’s body may often disturb the conduct of the work. The general conditions which should control the experiment as well as the details thereof are given in the following method which, however, the ingenious analyst may profitably simplify. =108. Method of Pfaundler.=—The process of estimating the specific heat of soils by the method of mixture, is essentially that of Regnault and is described as follows by Pfaundler[75]. The apparatus used is illustrated in Fig. 13. A and A′ show the heating apparatus. It consists of a vessel of sheet iron in which a test tube E is fixed by means of a cork. The test tube holds the soil whose specific heat is to be determined. The apparatus contains water, which is brought to the boiling point by means of a lamp, and the excess of steam is conducted away, as indicated in the figure, through one of the axes of the apparatus; the opposite axis is, of course, closed. It requires about thirty-five minutes boiling to bring the contents of the test tube to the temperature of the aqueous vapor. The exact temperature at which the water boils is determined by observing the barometer at the time and consulting a table of the boiling temperature of water at different barometric pressures. The calorimeter is shown in the figures B and B′. It consists of a wooden box closed on one side by a glass plate G and on the other to the heighth F by a small board on which a calorimeter of ordinary construction is placed. The cylinder of the calorimeter is seventy millimeters high and forty-seven millimeters in diameter. FIGURE 13. REGNAULT’S APPARATUS FOR DETERMINING THE SPECIFIC HEAT OF SOILS. ] This part of the apparatus is supported by triangular pieces of cork. A delicate thermometer is fastened to the top of the box of the calorimeter and the value of the degrees is so arranged that about twelve of them correspond to about one degree C. The scale of the instrument can be arbitrarily fixed and the temperature of any part of it determined by comparison with a delicately graduated thermometer. Near the thermometer in the calorimeter is a stirrer made of a very thin copper disk with a bent rim. This stirrer is operated by means of a silk cord moved by appropriate machinery. The reading of the thermometer is made through a glass plate and this should be protected from the heat of the body of the observer by a paper screen. The test tube E is first filled with the substance, whose specific heat is to be determined, and weighed. It is then placed in the water bath until constant weight is reached. After constant weight has been obtained the apparatus is again dried and the exact weight of the moisture lost thus determined. The test tube is then placed in the apparatus A closed with a well-fitted cork, the top covered with cotton and heated in the aqueous vapor for about one hour. The heating apparatus should be far removed from the calorimeter so that the temperature of the latter cannot be influenced thereby. Meanwhile the calorimeter is filled with water which has stood in the room for a long time until it has acquired, as nearly as possible, the room temperature. The quantity of water is such that the water value of the whole of the calorimeter together with the immersed portions of the thermometer and stirrer shall amount to exactly 100 grams. A few minutes before bringing the substance into the calorimeter, the stirring apparatus is put in motion and the temperature observations are commenced. These should be at intervals of twenty seconds and should be continued until ten observations have been made. Meanwhile the height of the barometer is also read. A few seconds before the tenth interval the apparatus A is brought quickly to the calorimeter and its contents emptied into it at the moment of the tenth interval. The apparatus A should be removed as quickly as possible after its contents are emptied. After the introduction of the substance and its thorough incorporation with the water of the calorimeter by the stirring apparatus, the thermometer is again read, at intervals of twenty seconds, until its maximum has been reached and as much longer thereafter as may be necessary to show that an appreciable fall of temperature has taken place. The test tube, in which the substance was heated is weighed and the exact quantity of the added substance thus determined. In order that the sample of soil may be easily removed from the test tube in which it is heated, it is best to have it molded into appropriate forms before being placed in the heating tube. This is easily accomplished by pressing it into molds of convenient shape and of a size so that six or eight pieces (best of cylindrical shape) will be necessary to give the quantity sufficient for the experiment. Since some soils will not retain their shape after molding, the molds may be made of zinc foil whose water values in the calorimeter are previously determined and they can be placed with their contents in the calorimeter thus securing the total immersion of all the particles of soil in the water. With very dusty materials, it is necessary that these little cylinders should be closed with pieces of foil at the ends in order to prevent the particles of dust from escaping and rising to the surface of the water. Another source of error consists in the solution of the soluble salts which the soil may contain. This is avoided by the use of turpentine instead of water. If the cylinder containing the soil be made water-tight, this danger from the solubility of the salts in water is avoided. Another method of correcting these errors is in making a blank experiment in which a quantity of the earth taken is kept at the temperature of the water in the calorimeter until both are of the same temperature. The earth is then mixed with the water and the change of temperature produced noted. In this way the corrections made necessary by the solution of the salts in water and other causes are determined. =109. Method of Calculating Results.=—Let t represent the mean temperature of the beginning period of the experiment, and v equal the loss in heat per interval. Let t′ and v′ represent the same values for the end period. Let θ₁, θ₂, θ₃, etc., represent the temperature at the end of the first, second and third intervals of the middle period and θ₀ the temperature at the beginning of the middle period and θₙ the end temperature of of the middle period. Let τ₁, τ₂, τ₃, ... τₙ, represent the mean temperature of the single intervals; then τ₁ = (Θ₀ + Θ₁)/(2); τ₂ = (Θ₁ + Θ₂)/(2), and τₙ = (Θ_{n–1} + Θₙ)/(2). The constant C represents the correction which must be applied in order to determine the true increase of temperature in the calorimetric system. The expression θₙ − θ₀ + C represents the true temperature increase of the calorimetric system which we may represent by Δθ and θₙ + C represents the true maximum, that is, the end temperature, which by exclusion of external influences is reached. The correction C, as already indicated, is to be added to θₙ − θ₀ when it is positive and is to be subtracted therefrom when it is negative. The numerical value of C is usually very small, and, in the experiments indicated, varied between zero and one division of the thermometer employed, that is it seldom exceeded one degree. =110. Illustration.=—The method of determining value of specific heat is best illustrated by an example: In one determination the water value of the calorimetric system, including stirrer and thermometer was 2.50 grams, the weight of water added was 97.50 grams and the total water value of the system 100 grams. The substance was dried at 100° and weighed in five envelopes: Total weight 31.423 grams. The envelopes alone weighed 10.654 „ Weight of the soil taken 20.769 „ The envelopes holding the soil were made of brass with zinc ends, the specific heat of which is 0.0939 and the water value of the whole of the envelopes was 1.0004 grams. Since, however, the ends were soldered on with zinc the true water value was somewhat smaller being equal to 0.8692 gram. The data of the observations were as follows: Corrected height of barometer 699.6 millimeters. Intervals between the observations 20 seconds. No. of Temperature on the Observations. arbitrary scale of the thermometer. First Period { 0 162°.6 „ {10 162°.9 = θ₀ (Moment of immersion.) Second Period {11 185°.0 „ {12 200°.0 „ {13 206°.1 „ {14 209°.5 „ {15 210°.7 „ {16 211°.3 „ {17 211°.5 Differences. „ {18 211°.5 0 „ {19 211°.5 0 „ {20 211°.5 0 „ {21 211°.5 0 „ {22 211°.4 –0°.1 = θₙ –0°.1 –0°.1 Third Period {23 211°.3 „ {24 211°.2 –0°.1 „ {25 211°.1 –0°.1 „ {26 211°.0 –0°.1 „ {27 210°.9 –0°.1 „ {28 210°.8 –0°.1 „ {29 210°.6 –0°.2 „ {30 210°.5 –0°.1 From the twenty-second interval, the regular fall of temperature begins and 211°.4 is therefore taken as θₙ. The mean temperature of the beginning period is therefore (162°.6 + 162°.9)/(2) = 162°.75 = t. The value of v is (162°.6 − 162°.9)/(10) = –0°.03. For the end period the value of t′ is (211°.4 + 210°.5)/(2) = 210°.95 and the value of v′ is (211.4 − 210.5)/(8) = + 0.11. Then the sum of the observations from eleven to twenty-one inclusive = Σ′_{n–1}θ = 2280.1 (θ₀ + θₙ)/(2) = 187.15 The sum = 2467.25 nt = 1953.00 Difference 514.25 This difference multiplied by v − v′ = 0.14 gives a product equal to 71.995 This product divided by t′ − t = 48.20 gives a quotient equal to 1.49 nv = –0.36 The sum = 1.13 = C Then Δθ = θₙ − θ₀ + C = 211°.4 − 162°.9 + 1°.13 = 49°.63. The true end temperature = θₙ + C = 212°.53. The zero point of the thermometer = 24°.70, and the actual rise of temperature = 187°.83. The rise of temperature due to the proximity of the warming apparatus at the beginning was found by experiment to be equal to 0°.1 of the division of the scale. On comparing the thermometer used with a standard centigrade scale it was found that one division of the calorimetric thermometer was equal to 0°.0858. Converting these numbers into expressions of the centigrade scale we have the following summary: The true rise of temperature, Δθ = 4°.25 The true end temperature, θₙ + C = 16°.10 The temperature of the steam, as determined by the height of the barometer, was equal to 97°.70 From these data the specific heat is calculated according to the following formula: Σ = 1/20.769 × ((100 × 4.25)/(97.70 − 16.10) − 0.8692) = 0.2089. From this formula the following rule for calculating specific heat is deduced: Multiply the water value of the calorimetric system by the true rise in temperature in degrees Celsius and divide the product by the difference between the temperature of boiling water under the conditions of the experiment and the true end temperature. From the quotient subtract the water value of the envelopes holding the soil sample. Divide the remainder by the weight of soil taken. =111. Variations in Specific Heat.=—Different soils deport themselves very differently in respect of specific heat. In a large number of soils examined by Pfaundler, the specific heats were found to vary from 0.19 to 0.51. The highest specific heat was observed in the case of a peaty soil. Next to peaty soils came those soils which were highest in humus, and in general it was found that the specific heat varied directly with the humus content. SOIL THERMOMETRY. =112. General Principles.=—The measurement of the temperature of the soil at stated depths is often of use in analytical processes connected with agricultural chemistry and physics. The general principles on which the process rests, depend on bringing the bulb of the thermometer into as intimate contact as possible with the particles of soil at the depth required, disturbing as little as possible the normal state of the soil particles. In the thermometer chiefly used for this purpose in this country, the stem is strong and carries the degrees figured on the glass. The whole is inclosed in a wooden case which is cut away to expose the face of the scale. The scale is about eleven inches long. The part which enters the soil is of varying lengths, according to the depth at which the temperature is desired. =113. Method of Procedure.=—An excellent method of determining soil temperatures and of recording results is well illustrated by Frear.[76] The thermometers are set in niches cut in a trench, the earth being afterwards carefully tamped about the bulbs to secure a good contact, the trench being filled at the same time. The surface of the soil is freed from vegetation and kept in good tilth. The depths at which observations are made are at the surface and one, three, six, twelve, and twenty-four inches. The soil tested was moderately dark and loamy to a depth of seven inches and below that a stiff clay. Solid rock existed at from five to seven feet below the surface. Readings were made three times a day. =114. Method of Stating Results.=—The individual readings of the thermometers should be entered at the time they are made. At the end of each month the mean of the readings should be determined, together with the maxima and minima, and a comparison made between the mean readings of the temperature of the air and maxima and minima. As a sample of the method of stating these mean results the data are given for the month of May, 1891, for the atmosphere, surface, and for the depths mentioned above: MAY. T° Fahrenheit. ATMOSPHERE. Monthly mean 57.1 Maximum 85.0 Minimum 31.0 Mean daily range 22.5 Greatest daily range 32.0 Least daily range 8.0 SURFACE. Monthly mean 56.7 _Extremes._ Maximum (10th of month) 77.0 Minimum (5th) 36.0 Mean maximum 65.2 Mean minimum 49.9 _Range._ Monthly 41.0 Mean daily 14.9 Greatest daily (19th) 25.0 Least daily (21st) 4.0 ONE INCH. Monthly mean 56.8 _Extremes._ Maximum (10th) 74.5 Minimum (5th) 36.5 Mean maximum 62.9 Mean minimum 49.5 _Range._ Monthly 38.0 Mean daily 11.9 Greatest daily (10 and 19) 20.0 Least daily (23rd) 1.0 THREE INCHES. Monthly mean 56.7 _Extremes._ Maximum (31st) 71.0 Minimum (6th) 40.0 Mean maximum 60.9 Mean minimum 49.7 _Range._ Monthly 31.0 Mean daily 9.3 Greatest daily (19th) 15.5 Least daily (23rd) 1.5 SIX INCHES. Monthly mean 56.3 _Extremes._ Maximum (31st) 66.0 Minimum (6th and 7th) 43.0 Mean maximum 56.7 Mean minimum 53.2 _Range._ Monthly 23.0 Mean daily 4.65 Greatest daily (8 and 19) 8.5 Least Daily (5th) 1.0 TWELVE INCHES. Monthly mean 55.6 _Extremes._ Maximum (31st) 64.0 Minimum (6th and 7th) 46.0 Mean maximum 56.6 Mean minimum 54.4 _Range._ Monthly 18.0 Mean daily 2.18 Greatest daily (8th) 4.5 Least daily (3rd and 20th) 0.0 TWENTY-FOUR INCHES. Monthly mean 53.1 _Extremes._ Maximum (31st) 58.0 Minimum (6th and 8th) 48.0 Mean maximum 53.4 Mean minimum 52.8 _Range._ Monthly 10.0 Mean daily 0.48 Greatest daily (23rd) 2.0 Least daily (on 12 days) 0.0 FIG. 14. SOIL THERMOMETER—Whitney and Marvin. ] =115. Method of Whitney and Marvin.=[77]—The thermometer devised by Whitney and Marvin is shown in Fig. 14. The principle on which this modification depends is as follows: A mercurial thermometer of the ordinary construction is liable to give wrong indications of the temperature because it is difficult to determine the temperature of the column of mercury from the bulb to the surface of the ground. To avoid this source of error the thermometer figured was constructed. The bulb of the thermometer is made quite small and a slender portion of the stem extends into its spherical portion. The top portion of the thermometer stem does not differ in any essential respect from the stem of an ordinary thermometer. The bulb is almost wholly filled with alcohol, which acts as the principal thermometric fluid and has the advantages of a high coefficient of expansion. The thermometer bulb and the stem of the thermometer up to a point convenient for graduation, are filled with mercury. In the drawing the mercury is represented by the heavy black marking in and just above the small bulb. The peculiar construction at this point is for the purpose of retaining the mercury about the point of the slender capillary stem inside the bulb and preventing the entrance of alcohol into the stem when the thermometer is horizontal. In order to register the maximum and minimum temperatures a short column of alcohol is placed in the upper portion of the stem, above the mercury, and within this are arranged two small steel indexes, so constructed that they will not slide in the tube of their own weight, but are easily pushed upward by the mercury column or pulled downward by the top meniscus of the alcohol column. The indexes are set by means of a small magnet, the one being drawn down upon the top of the mercurial column and the other raised up against the meniscus of the alcohol column. The rise of the mercury carries its index upward, leaving it to register the highest point reached, while the alcohol meniscus withdraws the other index and leaves it at a point representing the minimum temperature. It remains only to mention that the graduations are fixed in the usual way, having reference only to the positions of the mercurial column. Beyond the highest point supposed to be reached by the mercury, say about 120°, the graduations are extended in an arbitrary manner. The scale numbers represent temperatures by the mercurial column and are continued in regular sequence beyond the 120°. On this plan the readings for minimum temperatures are on a purely arbitrary scale and are converted into true degrees of temperature by use of a table prepared for each thermometer, which table embodies as well all the corrections for instrumental error. The arrangement of the alcohol columns above the mercurial column and the indexes are shown enlarged at one side of the illustration. The readings of the maximum temperature are made from the bottom end of the index next to the mercurial column. The minimum temperature is the reading of the top of the uppermost index. Thus in the figure the maximum temperature indicated is 76.5°, and the minimum 125.7°, which, by reference to the table of correction for this thermometer, No. 10, is found to be 53.3°. The use of mercury in the stem of the thermometer not only admits of the use of the index for registering the maximum temperature, but possesses the additional advantage of reducing the error due to uncertain temperature of the stem to about one-sixth what it would be if alcohol were used. Moreover, if necessary, as in the case with thermometers for greater depths than that figured, the ungraduated portion of the stem can be made of very much finer bore than the graduated portion, the effect of which is to diminish the objectionable error to a comparatively unimportant quantity. The chief objection to thermometers of this construction is the liability of alcohol getting from the bulb into the stem during the processes of construction, graduation and subsequent handling, and the difficulty of safely shipping them. When once set up, however, there seems to be little or no possibility of derangement and the error common to mercurial thermometers due to rise of the freezing point with age does not apply owing to the high coefficient of expansion of the alcohol used in the bulb. APPLICATIONS OF SOIL THERMOMETRY. =116. Estimation of the Absorption of Heat by Soils.=—A cubical zinc box, six centimeters square, is filled with the sifted air dried soil. The box, one side of which is left open, is encased snugly in a wooden cover, exposing only the open end, and placed for a few hours in the direct rays of the sun. The temperature is then taken at a given depth. The box may be provided with thermometers at different depths, the bulbs thereof extending to the center. In this case the box should be covered with thick felt instead of wood. The temperature of the layers of soils of different depths can thus be read off directly. The air temperature directly above the box should be accurately noted while the experiment continues. Any other kind of box well protected against all heat save the direct sunlight on the open surface of the soil will answer as well as the one described. To determine the action of moist earth in similar conditions the soil may be previously moistened; the per cent of moisture being determined in a separate portion of the soil or the amount of water added to the air-dried soil being noted. =117. Estimation of the Conductivity of Soils for Heat.=—The bulb of a thermometer is placed in the middle of a mass of fine earth which is then exposed, best in a metallic box painted with lamp black, in a warm place. The time required for the thermometer to reach a certain degree is noted. By reversing the experiment and placing the mass of earth heated to a given degree in a cool place the conductivity can be determined by the time required for the mercury in the thermometer to fall to any given point. The experiment may also be made by packing the soil by gently jolting it in a glass tube six to eight centimeters in diameter. One end of the tube is closed with a piece of metal or fine wire gauze painted with lamp black and is exposed to the source of heat. The bulb of a thermometer is placed at a given distance from the end of the tube and the time for the mercury to be affected observed. COHESION AND ADHESION OF SOILS. =118. Behavior of Soil After Wetting.=—The deportment of a soil when thoroughly wet in respect of its physical state on drying out is a matter of great practical concern to the agronomist. Some soils on becoming dry fall into a pulverulent state and are easily brought into proper tilth; others become hard and tenacious, breaking into clods and resisting ordinary methods of pulverization. The physical laws which determine these conditions depend largely on the principles of flocculation soon to be described. The present task is to describe briefly some of the methods of estimating the force of cohesion and adhesion. =119. General Method.=—The fine earth, air-dried, is mixed with enough water to make a paste and molded into forms suitable for trial in a machine for testing strength of cement, etc. The forms most used are cakes three to five centimeters in length and one to two centimeters thick. These are used for determining crushing power. For longitudinal adhesion the paste may be molded in prismatic or cylindrical shape.[78] The prisms should show one to two centimeters in cross section or the cylinder be one to two centimeters in diameter. Before use they are to be exposed for several days until thoroughly air-dried. The force required to separate or crush these prepared pieces will measure the adhesive or cohesive property of the sample. A great number of trials should be made and the mean taken. =120. Method of Heinrich.=[79]—This process consists in mixing the air-dried earth with water until its aqueous content is fifty per cent of the highest water capacity determined by experiment. The sample is next placed between two pieces of sheet iron of ten centimeters square, each of which in its middle point is provided with a hook. The thickness of the layer between the two pieces of iron should be about five to ten centimeters. The exuding particles of soil are cut off with a knife. The upper piece of sheet iron is next suspended by a cord in such a way that the iron piece occupies a horizontal position. A small basket is attached to the lower surface and sand added thereto, little by little, until the column of earth is separated. The sand basket and iron plate are weighed, and the total weight gives the power necessary to separate a column of soil ten centimeters square in cross section. The iron plates may be roughened so that the adhesion thereto of the soil is greater than its cohesive force. =121. Adhesion of Soil to Wood, Iron, Etc.=—The adhesive power of moist soil for wood, iron, etc., is measured by Heinrich[80] in the following way: The soil is mixed with water, as above, until it contains just fifty per cent of its total water-holding content. It is then placed in a large vessel and the upper surface made as smooth as possible. A plate of wood, iron, etc., of ten centimeters square is then pressed on the surface until a complete contact is secured. This plate, by means of a hook and cord passing over a pulley, is then subjected to stress by weighting the cord which carries a basket for that purpose. The basket should be of the same weight as the plate in contact with the soil. The weight added to the basket necessary to separate the plate from the soil is taken to represent the cohesive force. The author of the method appears to take no account of the pressure of the air on the plate caused by the exclusion of the air from its under surface. THE ABSORPTIVE POWER OF SOILS FOR SALTS IN SOLUTION. =122. General Principles.=[81]—It is a fact of every-day observation that soils have a particular property of absorbing certain materials with which they come in contact. If it were not for this property all our wells would soon become unwholesome from the reception of decayed animal and vegetable matter carried to them in the drainage water from the surface. It is also a well-known fact that burying dead bodies prevents the gaseous products of decomposition from reaching and vitiating the atmosphere. Besides this well-known power of soils to absorb the decomposition products of animal and vegetable matter, they also possess a property which is of far greater importance in plant economy; that is, the power of withdrawing and retaining certain mineral constituents from their solutions. As far back as the sixteenth century mention is made by Lord Bacon of a process for obtaining pure water on the seashore by simply digging a hole in the sand and allowing it to fill with filtered sea water, which by this means is deprived of its salt. Although certain facts were observed by some of the earlier writers in regard to soil absorption, no systematic researches were conducted with a view of demonstrating the extent and cause of this power until within a comparatively few years. In 1850 Prof. Way published in the _Journal of the Royal Agricultural Society of England_, the results of a thorough and most excellent investigation of the subject. Since then many distinguished chemists, such as Henneberg, Stohmann, Peters, Heiden, Knop, Ullik, Pillitz, Biedermann, Tuxen, and others have given their attention to this matter. =123. Summary of Data.=—If a solution of a soluble sulfate, chloride or nitrate of an alkali or an alkaline-earth metal be placed in contact with a soil, the result is that the soil takes up a part of the base but none of the acid. This absorption of base is attended with the liberation of some other base from the soil which combines with the acid of the solution. Any alkali or alkaline earth base has the power of replacing any other such base. However, if soluble phosphates and silicates of these bases be placed in contact with the soil both the base and the acid are removed from the solution. Peters[82] has shown that the amount of absorption depends upon the concentration of the solution, the relation between the quantity of solution and the soil and the kind of salt used. He treated 100 grams of earth with 250 cubic centimeters of solutions of different potash salts with the following results: Strength of solution. ⅒ Normal. ¹⁄₂₀ Normal. Grams Grams Salt Used K₂O absorbed. K₂O absorbed. KCl 0.3124 0.1990 K₂SO₄ 0.3362 0.2098 K₂CO₃ 0.5747 0.3154 Biedermann[83] proves that, for phosphoric acid at least, the absorption increases with the temperature. It has also been found that the amount of absorption depends upon the time of contact between the soil and solution. Way found that the absorption of ammonia was complete in half an hour, while Henneberg and Stohmann[84] noticed that the phosphoric acid continued to be fixed after the expiration of twenty-four hours. It is a very important fact that the absorption of a base is never complete; no matter how dilute the solution it will still carry a small portion of the base with it. Peters states that it requires about 28,000 parts of water to remove one part of absorbed potash and Stohmann found that it required about 10,000 parts of water to remove one part of absorbed ammonia. With phosphoric acid, the resulting compound seems to be much more insoluble. According to Tuxen[85] the presence of salts of soda and potash in solution decreases the power of a soil to absorb ammonia compounds and the presence of sodium salts decreases the power of a soil to absorb potash. On the other hand the presence of potassium compounds considerably increases the absorption of phosphoric acid. He further affirms that the compounds of potash, phosphoric acid, etc., formed in the soil, are decidedly more soluble in sodium salts than in pure water. =124. Cause of Absorption.=—The withdrawing and fixing of phosphoric acid from solutions by the soil is not very difficult to understand as this acid forms insoluble compounds of iron, lime, and magnesium, some or all of which are present in all soils. As to the absorption of the alkalies, the explanation is far more difficult as nearly all of their ordinary compounds are readily soluble in water. As lime is usually found combined with the acid part of an alkali salt, from which the base has been absorbed by the soil, it might naturally be supposed that the absorptive power of the soil would depend upon the amount of lime present. Way found, however, that the addition of chalk in no way influenced the absorption of ammonia by a soil which contained but a small amount of lime. This fact was also confirmed by Knop[86] who found that chalk exerted no influence on the absorption of ammonia salts. These facts would seem to point to the conclusion that lime was present in sufficient quantity in these experiments, or that it is not essential to the phenomena of absorption. However, as any alkali or alkaline-earth base can replace any other such base, the presence of lime in the filtrate is probably more of an accidental occurrence, owing to the comparatively large amount of that substance in most soils, than a necessary condition, as any other base would doubtless answer in the absence of lime. =125. Warington=[87] has shown that hydrated oxides of iron and aluminum, and especially the former, are capable of absorbing potash and ammonia, and as more or less of these hydrates exist in nearly all soils, a part, at least, of absorptive phenomena is to be ascribed to them. =126. Way= tried to determine which of the constituents of a soil exercised chiefly the absorptive power. He passed a solution of ammonia through tubes containing pure sand and found that it came through apparently unaltered from the first, while a soil treated in the same way removed the ammonia for a considerable time. He concluded from this that the absorptive power does not exist in the sand. He next oxidized the organic matter in a soil with nitric acid and then treated it with ammonia in the same way. The first portions of the filtrate showed no ammonia in any form, hence he concluded that organic matter is not essential to the act of absorption. He further showed that clay alone is capable of causing absorption phenomena, by treating powdered clay tobacco pipes with ammonia. Having shown that clay was the main constituent in a soil which caused the absorption of alkalies, he tried next to trace out the particular compound which caused the absorption. Having tried various natural silicates he at last succeeded in producing a hydrated silicate of aluminum and soda which exhibited displacement and absorptive properties very similar to those shown by the soil. As Way had succeeded in producing an artificial hydrated silicate possessing absorptive properties, Eichorn[88] thought of trying natural hydrated silicates or zeolites and found that they exhibited the same power as Way’s artificial preparation. It has also been shown by Biedermann,[89] Rautlenberg,[90] and Heiden[91] that the absorptive power bears a close relation to the amount of soluble silicates present. In view of these facts it is now generally accepted that the absorption of salts of the alkalies, accompanied by the change of base, is due chiefly to the presence of decomposed zeolite minerals in the soil. Besides the purely chemical absorption of salts by the soil, we have a physical absorption of various substances similar to the action of charcoal when used as a filter. =127. Conclusions of Armsby.=—The data connected with the absorption of bases by a soil have also been reviewed by Armsby.[92] He shows that the absorption is accompanied by a chemical reaction between the salt whose base is absorbed and some constituent of the soil, and this change seems to be due particularly to certain zeolitic silicates, although Liebig and others were disposed to credit this absorption largely to physical causes. Knop advances the idea that the soil has the power of disintegrating salts in the presence of some substances like calcium carbonate which can unite with the acid. In experiments made with hydrous silicates it was shown that the absorption resembled in all cases like phenomena in the soil; hence the supposition already advanced in regard to the influence of such silicates is doubtless true. In respect of absorption in general, the following conclusions were reached: 1. The absorption of combined bases by the soil consists in an exchange of bases between the salt and the hydrous silicates of the soil. 2. This exchange, which is primarily chemical, is only partial, its extent varying (a) with the concentration of the solution, and (b) with the ratio between the volume of the solution and the quality of soil used. 3. The cause of these variations is probably the action of mass or the tendency of resulting compounds to re-form the original bodies, the absorption actually found in any case marking the point where the two forces are in equilibrium. =128. Selective Absorption of Potash.=—As a rule more potash is absorbed from the sulfate than from the chlorid. This fact would seem to point to the advisability of using sulfate as a fertilizer in preference to chlorid. However, as with the exception of nitrates, the absorptive power of a soil, for the salts used as fertilizers, is many times greater than it is ever called upon to exert in fixing applied fertilizers, we need not trouble ourselves in regard to the absorption of phosphoric acid, potash or ammonia, in so far as the practical side of the matter is concerned. For example, an acre of soil to the depth of nine inches weighs about 900 tons. Now it has been found by Huston,[93] that 100 parts of a soil experimented upon absorbed over 0.25 part of P₂O₅, hence 900 parts would absorb over 2.25 parts of P₂O₅; or an acre of this soil to the depth of nine inches would absorb over two and one-fourth tons of phosphoric acid. 500 pounds per acre is a large dressing of a phosphatic fertilizer for field crops and 500 pounds of a high grade fertilizer would contain about 100 pounds of P₂O₅; hence the power of such a soil to absorb phosphoric acid is more than forty-five times as great as it is ever likely to be called upon to exert in fixing the phosphoric acid added to it as a fertilizer. Huston has further shown that an acre of soil nine inches deep will absorb more than 2.7 tons of potash (K₂O) from potassium chlorid from which salt less potash is absorbed than from the sulfate. Now one-tenth ton of potassium chlorid per acre would be a large dressing of potash, hence this soil possesses the power of absorbing more than twenty-seven times as much potash as is ever likely to be applied as a fertilizer. In like manner it may be shown that the power of an acre of soil nine inches deep to absorb ammonia from ammonium sulfate is more than thirty-two times as great as it would be called upon to exert in fixing the ammonia from a dressing of one-quarter ton of ammonium sulfate per acre. With sodium nitrate, however, there is no absorption; hence great care is necessary in the application of nitrogen as a nitrate, for, if it be put on in large quantities, at a season when the plant is not prepared to assimilate it, or during a period of heavy rains, there must unavoidably result loss from drainage. The best time to apply a nitrate is evidently during the active growing season. =129. Whitney=[94] places great emphasis on the surface area of soil particles in respect to their power to absorb solutions of salts. The approximate surface area of a cubic foot of each of the different typical soils of Maryland is as follows: Pine barrens 23,940 square feet. Truck lands 74,130 „ „ Tobacco lands 84,850 „ „ Wheat lands 94,540 „ „ River terrace 106,260 „ „ Limestone subsoil 202,600 „ „ It will be seen that there are about 24,000 square feet of surface area in a cubic foot of the subsoil of the pine barrens, no less then 100,000 square feet or two and three-tenths acres of surface area in a cubic foot of the subsoil of the river terrace, and 200,000 square feet of surface area in a cubic foot of the limestone subsoil. These figures seem vast, but they are probably below rather than above the true values, on account of the wide range of the diameters of the clay group. This great extent of surface and of surface attraction, which has been described as potential, gives the soil great power to absorb moisture from the air, and to absorb and hold back mineral matters from solution. A smooth surface of glass will attract and hold, by this surface attraction, an appreciable amount of moisture from the surrounding air. A cubic foot of soil, having 100,000 square feet of surface, should be able to attract and hold a considerably larger amount of moisture. It might have been added that if the potential of the surface, separating the solution from the soil, be greater than the potential in the interior of the liquid mass, there will be a tendency to concentrate the liquid on this surface of separation. It has been shown that certain fluids have greater density on a surface separating the fluid from a solid. On the other hand, if the potential were low there might be no tendency for this concentration, and even the reverse conditions would prevail and the soluble substance could be readily washed out of the soil. =130. Removal of Organic Matters.=—It is probably largely due to this straining power that organic matters are removed from solutions in percolating through the soil. Whitney[95] has observed that the organic matter may be coagulated and precipitated from solution by the soil constituents, and held in the soil in loose flocculent masses, while the liquid passes through nearly free of organic matter. =131. Importance of Soil Absorption.=—The importance of the absorptive power of the soil can hardly be overestimated. By means of this power those mineral ingredients of plant food, of which most soils contain but little, are held too closely to allow of rapid loss by drainage, and still sufficiently available to answer the needs of vegetation, provided the store is large enough. The only important plant food liable to be deficient in the soil which does not come under the influence of absorption is nitrogen in the form of salts of nitric acid, and nature has made a wide provision for this element by binding it in the form of organic bodies which nitrify but slowly, and by supplying each year a small quantity from the atmosphere. By means of the absorptive power of soils the farmer, if he puts on an excess of potash or phosphoric acid as a fertilizer, does not lose it but is able to reap some benefits from it in the next and even in succeeding crops. If it were not for this power the best method for applying fertilizers would be a much more complicated problem than it is at present; and it would be necessary to apply them at just the proper season and in nicely regulated amounts to insure against loss. =132. Method of Determining Absorption of Chemical Salts.=—The soil which is to be used for this experiment should be treated as has been indicated and passed through a sieve the meshes of which do not exceed half a millimeter in size. From twenty-five to fifty grams of the fine earth may be used for each experiment. The fine earth should be placed in a flask with 100 to 200 cubic centimeters of the one-tenth to one-hundredth normal solution of the substance to be absorbed. The flask should be well shaken and allowed to stand with frequent shaking twenty-four to forty-eight hours at ordinary temperatures. The whole is then to be thrown upon a folded filter and an aliquot part of the filtrate taken for the estimation. The methods of determining the quantities of the substances used will be found in other parts of this manual. It is recommended to conduct a blank experiment with water under the same conditions in order to determine the amount of the material under consideration abstracted from the soil by the water alone. The difference in the strength of the solution as filtered from the soil, corrected by the amount indicated by the blank experiment, and the original solution will give the absorptive power of the soil for the particular substance under consideration. If it should be desired to determine the absorptive power of the soil for all the ordinary chemical fertilizing materials at the same time, a larger quantity of the sample should be taken corresponding to the increased amount of the standard solutions used. About 500 cubic centimeters of the mixed salt solution should be shaken with 125 grams of the earth and the process carried on in general as indicated above. The absorption coefficient of an earth for any given salt according to Fesca,[96] is the quantity of the absorbed material expressed in milligrams calculated to a unit of 100 grams of the soil. =133. Method of Pillitz and Zalomanoff.=—It is recommended by Pillitz and Zalomanoff[25] to reject the old method, _viz._, shaking the soil with the solution in a flask, and substitute the filtration method both because it gives a more natural process and because the results are more constant. The apparatus is shown in Fig. 15. FIGURE 15. ZALOMANOFF’S APPARATUS FOR DETERMINING ABSORPTION OF SALTS BY SOILS. ] Two cylinders are placed vertically, one over the other. The lower cylinder is graduated in cubic centimeters, the upper cylinder is closed at each end by perforated rubber stoppers A and B through the openings of which the glass tubes _c_ and _d_ pass. Within the cylinder A the opening of the small tube _d_ is closed with a disk of Swedish filter paper. The lower part of the small tube is _d_ connected by means of a rubber tube carrying a pinch-cock C, with another small tube _e_ which passes through the stopper _f_. In carrying out the process the weighed quantity of soil is placed in the upper cylinder and afterwards the measured quantity of the solution, the whole thoroughly mixed and the cylinder closed. The valve C is then opened, a given quantity of the solution, but not all, is made to drop into the lower cylinder and the valve C is then closed. The liquid which has passed into the lower cylinder as well as that which remains in the upper cylinder, is thoroughly stirred and the quantity of the material remaining in both liquids determined and the absorbing power of the soil estimated from their difference. It does not appear that this method of estimation of the absorption power possesses any special advantages over the old and far simpler method of shaking in a flask. FIGURE 16. MÜLLER’S APPARATUS TO SHOW ABSORPTION OF SALTS BY SOILS. ] =134. Method of Müller.=—The method of Müller[97] for illustrating absorption is carried out by means of the apparatus shown in Fig. 16. A glass cylinder A about 750 centimeters long and four to five centimeters wide is closed at each end with rubber stoppers with a single perforation. The cylinder A is for the reception of the soil with which the experiment is to be made. Before using, the lower part of it is filled with glass pearls or broken glass and above this a layer of glass wool is placed about one centimeter thick. The object of this is to prevent the soil from passing into the small tube below. As soon as the soil has all been placed in the cylinder A the upper part of the tube is also filled with glass wool. The cylinder A is connected with the pressure bottle B by means of a rubber tube and the small glass bulb tube shown in the figure. The bottle B should have a content of about two liters. It is filled with the standard solution of the material of which the absorption coefficient is to be determined. At _c_ the rubber tube is connected with a glass T one arm of which is provided with a piece of rubber tubing which can be closed by means of a pinch-cock. At _c_ a screw pinch-cock is placed which can be used to regulate the flow of the solution from B to A. By opening the pinch-cock at _e_ on the short arm of the T piece, a sample of the original liquid can be taken and this can be compared with the part which runs to _b_. If it is desired for instance, to show that potassium carbonate has been absorbed by the soil the two bulbs shown on the small glass tubes connecting with A can be filled with red litmus paper. This paper will at once be turned blue in the lower bulb while in the upper one it will retain its original color because the liquid in passing through the soil will have lost its alkaline reaction. The solutions used should be very dilute. The apparatus is designed for lecture experiments and not for quantitative determinations. =135. Method of Knop.=—For rapid determination of the absorption coefficient of the soil Knop’s method may be used.[98] The fine earth which is employed is that which passes a sieve with meshes of half a millimeter. From 50 to 100 grams of this soil are mixed with from five to ten grams of powdered chalk and with about twice the weight of ammonium chlorid solution of known strength, _viz._, from 100 to 200 cubic centimeters. The ammonia solution should be of such a concentration that the ammonia by its decomposition for each cubic centimeter of the liquid evolves exactly one cubic centimeter of nitrogen. This solution is prepared by dissolving in 208 cubic centimeters of water one gram of ammonium chlorid. With frequent shaking the solution is allowed to stand in contact with the soil for forty-eight hours. The whole is now allowed to settle and the supernatant clear liquid is poured through a dry filter. From the filtrate twenty to forty cubic centimeters are removed by a pipette, and evaporated to dryness in a small porcelain dish, with the addition of a drop of pure hydrochloric acid. The ammonium chlorid remaining in the porcelain dish is washed with ten cubic centimeters of water into one of the compartments of the evolution flask of the Knop-Wagner azotometer. It is decomposed with fifty cubic centimeters of bromin lye and the nitrogen estimated volumetrically. The difference between the amount of nitrogen in this material and that of the original material will give the amount of absorption exercised by the fine earth. This number, without any further calculation, can be taken as the coefficient of absorption. =136. Method of Huston.=—The salt solutions recommended by Huston[99] are sodium phosphate (Na₂HPO₄), potassium chlorid, potassium sulfate, ammonium sulfate and sodium nitrate. The solutions should be approximately tenth normal, the actual strength in each case being determined by analysis. The phosphorus is determined as magnesium pyrophosphate in the usual way, the potash as potassium platinochlorid, the ammonia by collecting the distillate from soda in half normal hydrochloric acid and titrating with standard alkali, and the nitrate by Warington’s modification of Schlösing’s method for gas analysis. The details of these methods of determination will be given later. One hundred grams of the sifted, air-dried soil are placed in a rubber stopped bottle and treated with 250 cubic centimeters of the solution to be tested. The digestion is continued for forty-eight hours in each case, the bottles being thoroughly shaken at the end of twenty-four hours. At the end of the treatment the solutions are filtered and the salts determined in aliquot portions. The details of this method are essentially those already described. =137. Statement of Results.=—Duplicate analyses should be made and the tabulation of the data is illustrated in the following analyses by Huston: Na₂HPO₄ cubic Weight of Weight of P₂O₅ Salt centimeters Mg₂P₂O₇ in Mg₂P₂O₇ in absorbed removed filtrate taken. twenty-five filtrate. by 100 per cubic grams cent. centimeters of soil. the solution. (a) 25 0.1368 gram 0.0962 gram (b) 25 0.0963 „ 0.2589 29.6 gram —————— Mean 0.0963 „ KCl cubic Weight of Weight of K₂O Salt centimeters K₂PtCl₆ in K₂PtCl₆. absorbed removed filtrate taken. twenty-five by 100 per cubic grams cent. centimeters of soil. solution. (a) 25 0.6154 gram 0.4505 gram (b) 25 0.4540 „ 0.3161 26.5 gram —————— Mean 0.4523 „ K₂SO₄ cubic Weight of Weight of K₂O Salt centimeters K₂PtCl₆ in K₂PtCl₆. absorbed removed filtrate taken. twenty-five by 100 per cubic grams cent. centimeters of soil. solution. (a) 25 0.6113 gram 0.4426 gram (b) 25 0.4371 „ 0.3324 28.0 gram —————— Mean 0.4399 „ (NH₄)₂SO₄ cubic Number cubic Half normal acid N absorbed Salt centimeters centimeters neutralized. by 100 absorbed filtrate taken. one-half normal grams per acid neutralized soil. cent. by fifty cubic centimeters of solution. (a) 50 10.00 7.25 grams (b) 50 7.25 „ 0.0964 27.5 gram ———— Mean 7.25 „ NaNO₃ cubic Number cubic Cubic centimeter N absorbed Salt centimeters centimeters N₂O₂ N₂O₂ at 0° and by 100 absorbed filtrate taken. afforded by ten 1000 grams per cubic millimeters. soil. cent. centimeters of solution at 0° and 1000 millimeters pressure. (a) 10 16.63 16.77 grams (b) 10 16.70 „ none 00.00 ————— Mean 16.73 „ Upon comparing the figures it will be found that the absorption, passing from the greatest to the least, is as follows: phosphoric acid (P₂O₆), potassium sulfate, ammonium sulfate, potassium chlorid and sodium nitrate. It will be seen that there was no absorption in the case of the nitrate, while with each of the other salts there was quite a marked absorption. It will also be noticed that the percentages of absorption are not very different, and especially is this true of the potassium and ammonium salts, the P₂O₅ being somewhat higher. Whether this fact is merely an accidental occurrence or is due to the law of combination by equivalents could hardly be predicted from the single soil experimented upon; but taking into consideration the possibility of difference in solubility of the resulting compounds in the saline solutions used, and of other varying conditions, the percentages are evidently not far enough apart to exclude the possibility of the bases uniting in equivalent proportions. =138. Preparation of Salts for Absorption.=—The salts employed in the foregoing determinations are conveniently prepared, in fractional normal strength. In grams per liter the following quantities in grams are recommended, _viz._, 5.35 g NH₄Cl; 10.11 g KNO₃; 16.40 g Ca(NO₃)₂; 24.60 g MgSO₄ + 7H₂O; 23.4 g CaH₄(PO₄)₂, etc. The ammonium chlorid, potassium nitrate and magnesium sulfate can be weighed as chemically pure salts and the standard solution be directly made up. Calcium nitrate is so hygroscopic that a stronger solution must be made up, the calcium determined and the proper volume taken and diluted to one liter. Monocalcium phosphate is prepared as follows: A solution of sodium phosphate is treated with glacial acetic acid and precipitated with a solution of calcium chlorid. It is then washed with water until all chlorin is removed. The fresh precipitate is saturated with pure, cold phosphoric acid of known strength. After filtering the solution is placed in a warm room and left for two or three weeks until crystallization takes place. The crystals are pressed between blotting papers and finally dried over sulfuric acid and washed with water-free ether, and again dried. Since this salt is decomposed in strong solutions it should be used only in one hundredth normal strength, viz., 2.34 grams per liter. POROSITY AND ITS RELATIONS TO MOISTURE. =139. Porosity.=—The porosity of a soil depends upon the state of divisibility and arrangement of its particles, and upon the amount of interstitial space within the soil. If a soil be cemented together into a homogeneous mass, its porosity sinks to a minimum; if it be composed, however, of numerous fine particles, each preserving its own physical condition, the porosity of the soil will rise to a maximum. The porosity of a soil may be judged very closely by the percentage of fine particles it yields by the process of silt analysis to be described further on. In general, the more finely divided the particles of a soil, the greater its fertility. This arises from various causes; in the first place, such a soil has a high capacity for absorbing moisture and holding it; thus the dangers of excessive rain-falls are diminished, and the evil effects of prolonged drought mitigated. In the second place, a porous soil permits a freer circulation of the gases found in the soil. The influence of lime in securing the proper degree of porosity of a soil is very great, especially in alluvial deposits and other stiff soils. It prevents the impaction which will necessarily follow in a soil which is too finely divided. In general, the porosity of the soil may be said to depend on three factors, _viz._: 1. Upon the state of divisibility or the number of particles per unit volume; 2. Upon the nature and arrangement of these particles; 3. Upon how much interstitial space there is in the soil. =140. Influence of Drainage.=—Good underdrainage increases the porosity of a soil by removing the excess of water during wet seasons and rendering the soil more suitable to capillary attraction which will supply moisture during dry seasons. The influence of tile drainage on the production of floods has been carefully studied by Kedzie,[100] who shows that surface ditching in conjunction with deforesting may increase floods and contribute to droughts, and that tile-draining may increase flood at the break-up in spring, when the water accumulated in the surface soil by the joint action of frost and soil capillarity during the winter, and the surface accumulations in the form of snow are suddenly set free by a rapid thaw. He also points out that during the warm months tile-draining tends to prevent flood by enabling the soil to take up the excessive rain-fall and hold it in capillary form, keeping back the sudden flow that would pass over the surface of the soil if not absorbed by it, and it mitigates summer drought by increased capacity of the soil to hold water in capillary form and to draw upon the subsoil water supply. =141. Soil Moisture.=—The capacity of a soil to absorb moisture and retain it depends on its porosity and is an important characteristic in relation to its agricultural value. The following general principles relating to soil moisture are adapted from Stockbridge:[101] During dry weather plants require a soil which is absorptive and retentive of atmospheric moisture. The amount of this retention is generally in direct ratio to two factors, _viz._, the amount of organic matter and its state of division. The capillary water of the soil is very closely related to its percolating power, since all waters in the soil are governed in their movements by what is known as capillary force. Liebenberg has shown that this movement may be either upwards or downwards, according as the atmosphere is dry or supplies soil-saturating rain. The water absorbed by the roots passes into the plant circulation, and the greater part is evaporated from the leaves. Where the supply of water is insufficient, the plant wilts, and if the evaporation long continue in excess of the supply obtained from the soil, the plant must die. The experiments of Hellriegel have shown that any soil can supply plants with all the water they need, and as fast as they need it, so long as the moisture within the soil is not reduced below one-third of the whole amount that it can hold. The quantity of water required and evaporated by different agricultural plants during the period of growth has been found to be as follows: One acre of wheat exhales 409,832 pounds of water. „ „ „ clover „ 1,096,234 „ „ „ „ „ „ sunflowers „ 12,585,994 „ „ „ „ „ „ cabbage „ 5,049,194 „ „ „ „ „ „ grape-vines „ 730,733 „ „ „ „ „ „ hops „ 4,445,021 „ „ „ Dietrich estimates the amount of water exhaled by the foliage of plants to be from 250 to 400 times the weight of dry organic matter formed during the same time. Cultivation conserves soil moisture. It must be remembered that this water contains soil ingredients in solution. Hoffmann has estimated that the quantity of matter dissolved from the soil by water varies from 0.242 to 0.0205 per cent of the dried earth. The experiments of Humphrey and Abbott have shown that about one-sixth of the total sediment of the Mississippi river is soluble in water. =142. Determination of the Porosity of the Soil.=—The porosity of the soil is fixed by the relative volume of the solid particles as compared with the interstitial space. It is most easily determined by dividing the apparent by the real specific gravity. Let the real specific gravity of a soil be 2.5445 and the apparent specific gravity of the same soil be 1.0990. The porosity is then calculated according to the following ratios, _viz._: 2.5445 : 1.099 = 100 : X Whence X = 43.2 = per cent volume occupied by the solid particles of the soil. The per cent volume occupied by the interstitial space is therefore 56.8. =143. Method of Whitney.=—The total volume of interstitial space within the soil, in which water and air can enter, is best determined by calculation from the specific gravity and the weight of a known volume of soil. To determine this in the soil in its natural position in the field, a sample is taken in the following way: A brass tube, about two inches in diameter and nine inches long, has a clock spring securely soldered into one end, and this end turned off in a lathe to give a good cutting edge of steel. The area enclosed by this steel edge is accurately determined, and a mark is placed on the side of the tube exactly six inches from the cutting edge. A steel cap fits on top of the brass cylinder to receive the blows of a heavy hammer or wooden mallet. The cylinder is driven into the ground until the six-inch mark is just level with the surface. The whole is then dug out, care being taken to slip a broad piece of steel under the cylinder before it is removed, so as to prevent the soil which it contains from falling out. The cylinder is then carefully laid over on its side, and the soil is cut off flush with the cutting edge of steel. The soil is then removed from the cylinder, carried to the laboratory and properly dried and weighed. The object of the steel inserted in one end of the cylinder is to reduce the friction on the inside of the tube to a minimum, and thus prevent the soil inside the cylinder being forced down below the level of the surrounding earth. The volume of the soil removed with this sampler can readily be determined by calculation, as the area of the end of the tube is known and the sample is six inches deep. In a sampler, such as described here, this volume is about 300 cubic centimeters. From the weight of soil and the volume of the sample, the volume of interstitial space may be found by the following formula: S = ([V − W/ω] × 100)/V S is the per cent by volume of interstitial space, V is the volume of the tube in cubic centimeters, W is the weight of soil in grams, and ω is the specific gravity of the soil. The specific gravity can be determined for each soil, or the factor 2.65 can be used, which is sufficiently accurate for most work. The per cent by volume of interstitial space in the undisturbed subsoil is found to range from about thirty-five for sandy land, to sixty-five or seventy for stiff clay lands. For the determination of the amount of water an air-dried soil will hold, if all the space within it is completely filled with water, an eight-inch straight argand lamp chimney, with a diameter of about two inches, can be conveniently used. A mark is placed on the side of the tube, six inches from one end, and the volume of the tube up to this mark is found by covering the end with a piece of thin rubber cloth, or by pressing the chimney down firmly on a glass plate, and making a water-tight joint with paraffin or wax. Water is then poured into the tube up to the six-inch mark, and the weight or volume of water determined. The tube can then be dried, a piece of muslin tied tightly over the top and the whole then weighed. Soil is carefully poured in and the tube gently tapped on a soft support until the soil is six inches deep in the tube, and has the desired degree of compactness. The weight and volume of the soil can thus be determined, and the volume of the interstitial space from the formula already given. This can also be determined directly by introducing water from above, or by immersing the cylinder of soil up to the six-inch mark in water, and allowing the water to enter the soil from below. With such a short depth of soil, very little water will flow out when the cylinder is suspended in the air. The amount which will flow out when the cylinder is thus suspended, will depend both upon the texture and the depth of soil. It is impossible, however, by this method, to completely remove the air or to completely fill the space within the soil with water; for as the water enters the soil, a considerable amount of air becomes entangled in the capillary spaces, and this could not be removed except by boiling and vigorous stirring, which would altogether change the texture of the soil. The amount of water held by the soil, or the amount of space within the soil into which water and air can enter, will evidently depend upon the compactness of the soil, and this is best expressed in per cent by volume of space. =144. Capacity of the Fine Soil for Holding Moisture.=—The soil, as it is taken from the field, may have quite a different water coefficient from the same soil after it has been passed through a fine sieve or been dried at air temperatures or at 100° or 110°. The method of determination which depends upon adding excess of water to a given weight of fine earth, and afterwards eliminating the excess by percolation or filtration, is apt to give misleading results. If, however, the results are obtained by working on the same weight of soil, and in the same conditions, they may have value in a comparative way. The comparison between soils must be made with equal weights, in like apparatus and with the same manipulation, to have any value. These determinations, however, cannot have the same practical value as those made in the samples in a natural condition as has just been described. =145. Method of Wolff Modified by Wahnschaffe.=[102]—A cylindrical zinc tube (Fig. 17), sixteen centimeters long and four centimeters internal diameter, is used, the cubical capacity of which is 200 cubic centimeters. The cylinder is graduated by placing the moist linen disk on the gauze and tying a piece of rubber cloth over the bottom. Water is now poured in until the level is even with the gauze bottom. Add then exactly 200 cubic centimeters of water, mark its surface on the zinc, throw out the water, and file the zinc down to the mark. The bottom of the tube is closed with a fine nickel-wire gauze. Below this a piece of zinc tubing, of the size of the main tube, is soldered; pierced laterally with a number of holes. Before using, the gauze bottom of the cylinder is covered with a moist, close fitting linen disk, and the whole apparatus weighed. It is then filled with the fine earth, little by little, jolting the cylinder on a soft substance after each addition of soil to secure an even filling. When filled even full the whole is weighed, the increase in weight giving the weight of soil taken. FIGURE 17. CAPACITY OF THE FINE SOIL FOR HOLDING MOISTURE. METHOD OF WOLFF MODIFIED BY WAHNSCHAFFE. ] A large number of cylinders can be filled at once and placed in a large glass crystallizing dish containing water and covered with a bell jar (Fig. 17). The water should cover the gauze bottoms of the cylinders to the depth of five to ten millimeters. More water should be added from time to time as absorption takes place. The cylinders should be left in the water until when weighed at intervals of an hour no appreciable increase in weight takes place. The temperature and barometer reading should be noted in connection with each determination. With increasing temperature the water coefficient is diminished. The method of Wolff, as practiced in the laboratory of the Chemical Division of the U. S. Department of Agriculture, has given very concordant results. Five determinations were made on a sample of vegetable soil with the Wolff cylinders, which were weighed at intervals of ten, twenty, and thirty days, with the following results: No. 1. Water absorbed after ten days 106.25 per cent „ 2. „ „ „ „ „ 105.68 „ „ „ 3. „ „ „ „ „ 105.86 „ „ „ 4. „ „ „ „ „ 106.11 „ „ „ 5. „ „ „ „ „ 105.83 „ „ —————— Mean 105.95 „ „ No. 1. Water absorbed after twenty days 106.44 per cent „ 2. „ „ „ „ „ 105.98 „ „ „ 3. „ „ „ „ „ 106.56 „ „ „ 4. „ „ „ „ „ 106.52 „ „ „ 5. „ „ „ „ „ 106.38 „ „ —————— Mean 106.38 „ „ No. 1. Water absorbed after thirty days 108.35 per cent „ 2. „ „ „ „ „ 107.60 „ „ „ 3. „ „ „ „ „ 108.32 „ „ „ 4. „ „ „ „ „ 107.86 „ „ „ 5. „ „ „ „ „ 107.87 „ „ —————— Mean 108.00 „ „ The data obtained show that there was a very slight increase in the amount of moisture absorbed after the tenth day. As will be seen, however, from the following data, the soil within the cylinder does not contain in all parts the same percentage of moisture, the lower portions of the cylinder containing notably larger proportions than the upper parts. The cylindrical soil column was divided into four equal parts and the moisture determined in each part. Beginning with the top quarter the percentages of moisture were as follows: First quarter 97.52 per cent Second „ 105.91 „ „ Third „ 112.83 „ „ Fourth „ 116.48 „ „ =146. Method of Petermann.=[103]—The method of Wolff as practiced by the Belgian Experiment Station, at Gembloux, is essentially the same as described above. Petermann recommends the use of tared cylinders twenty to twenty-five centimeters long and six to eight centimeters in diameter. The cylinder is to be filled with the fine earth, little by little, with gentle tapping after each addition. The bottom of the cylinder is closed with a perforated rubber stopper on which is spread a moistened disk of linen. The cylinder, thus prepared and filled, is weighed and afterwards placed in a vessel containing distilled water, to such a depth as to secure a water level about two centimeters above the lower surface of the soil in the cylinder. The level of the water is kept constant as the contents of the cylinder are moistened by capillarity. When the earth appears to be thoroughly moistened, as can be told by the appearance of the upper surface, maintain the contact with water for about five or six hours. The cylinder is then removed, the upper surface covered to avoid evaporation, allowed to drain for a few hours, wiped and weighed. The cylinder is again placed in water to see if any increase in weight takes place. The weight of the fine earth and of the absorbed water being known, the percentage of absorption is easily calculated. =147. Method of A. Mayer.=[104]—A glass tube, one and seven-tenths centimeters in diameter, composed of two pieces, seventy-five centimeters and twenty-five centimeters in length, is united by a piece of rubber tubing. The lower free end of the seventy-five centimeter piece is closed with a piece of linen. The tube is filled, with gentle jolting, to the depth of one meter with fine earth, the earth column thus extending twenty-five centimeters above the point of union of the two pieces. Thus prepared, a quantity of water is poured into the upper tube sufficient to temporarily saturate the whole of the soil. During the sinking of the water in the tube there is thus effected a moistening of the material before it is wholly filled with water. After waiting until the water poured on top has disappeared the tube is separated at the rubber tube connection and a sample of the moist soil taken at that point. This is at once weighed and then dried at 100°. The loss in weight gives the water absorbed. The number thus obtained is calculated to the standard by volume, by use of the number representing the apparent specific gravity of the fine earth. For sand of different degrees of fineness the following numbers were found: Degree of fineness 2 3 4 Per cent water absorbed 7.0 13.7 44.6 The numbers thus obtained are taken to represent the absolute water capacity of a mineral substance in powder. The full water capacity, _i. e._, the power of holding water when the powder is immersed in water, the excess of which is then allowed to flow away is much greater than the absolute number. This difference is shown in the following data: Quartz, size three. Clay, size three. Full water capacity 49.0 per cent 46.8 per cent Absolute water capacity 13.7 „ „ 24.5 „ „ In general the absolute is markedly inferior to the full water capacity. Only in the finest dust do the two numbers approach each other. =148. Volumetric Determination.=—A convenient apparatus for this determination has been devised by Mr. J. L. Fuelling, of the Chemical Division, Department of Agriculture. It is shown in Fig. 18. It consists of an ordinary percolator the diameter of which decreases slightly towards the lower end, a thick-wall rubber tube and an ordinary burette, divided in tenths. A rubber stopper is fitted to the mouth of the percolator and perforated twice—in the middle and at the side, the former for a small tube provided with pinch-cock and the latter for the neck of a small funnel. The whole is supported on a convenient stand, the clamp holding the percolator being placed above that supporting the burette, both clamps arranged to slide on the stand-rod. FIGURE 18. FUELLING’S APPARATUS. ] The method is as follows: A mark is placed upon the projecting tube at the lower end of the percolator, and the tube at this point may be drawn out sufficiently to decrease the width of meniscus to one-eighth inch. Into the percolator is first introduced a small disk of wire gauze or perforated porcelain, with heavy wire pendant in the tube. Through the rubber stopper a small glass tube is passed and its lower end pressed firmly upon the wire or porcelain disk, its upper end being curved and supplied with a pinch-cock. Into the percolator is now poured one inch of fine shot (No. 20) and then one inch of fine sand which has been previously digested with hydrochloric acid and well cleaned of dust by washing. _The zero._—After the shot and sand have been shaken even, the burette is filled with water and raised above the level of the sand, wetting the percolator for four inches of its length. The burette is lowered and the shot and sand bed allowed to drain by opening the pinch-cock of the inner tube. The burette is raised and the shot-sand flooded repeatedly until, by lowering the burette until the zero mark of the percolator tube is reached, a uniform reading on the burette is secured. Thus the shot-sand bed is completely charged with water. The water level is now made zero on the percolator stem, the burette filled to its zero mark and the apparatus is prepared for introduction of the soil. _The Determination._—From 100 to 200 grams of soil, previously dried free of moisture, are weighed, the burette raised until the water level is three inches above the sand, and the soil gently dropped through a funnel into the water. When the soil has been introduced and wetted completely the water level is raised above the soil and allowed to remain thus two hours. The burette is then lowered and the water allowed to drain from the wetted soil. Four to six hours are usually given the draining, the reading taken on the burette after establishing the zero on the percolator stem, the volume of absorbed water thus ascertained and divided by the weight of soil multiplied by 100; the result expresses the water absorbed per hundred of soil. Example: Water required to saturate disk, etc. 0.50 cubic centimeter. Weight of air-dried soil taken 20.00 grams. Moisture at 105° therein 14.25 per cent. Weight water in soil 2.85 grams. Reading of burette after saturation 10.75 cubic centimeters. Less water required for disk, etc 9.25 „ „ Temperature 20°.00 Weight of 9.25 cubic centimeters H₂O at 20° 9.22 grams. Total weight of water retained by soil 12.07 „ Per cent water retained by soil 60.35 per cent. For general analytical work the correction for variations in the weight of water for different temperatures is of no practical importance. =149. Accuracy of Results.=—A sample of soil from the beet sugar station, in Nebraska, gave the following duplicate results: First trial 45.75 per cent water. Second trial 44.85 „ „ „ Muck soils from Florida, containing varying proportions of sand, gave the following numbers: Soil number one, 144.85 per cent, and 145.43 per cent; soil number two, 109.13 per cent, and 107.93 per cent; soil number three (very sandy), 46.86 per cent, and 46.51 per cent. =150. Method of Wollny.=[105]—A zinc tube, ninety centimeters long and four centimeters internal diameter, carries at each end, at right angles to the axis, a flattened rim 1.5 centimeters broad. The lower end of the tube is closed with a strong piece of coarse linen. The soil to be examined is then filled in little by little, with gentle tamping. On the upper end two glass tubes are placed, each ten centimeters long and four centimeters internal diameter. These tubes are furnished at each end with cemented brass cylinders which are expanded to a circular, evenly ground rim, 1.5 centimeters wide, also at right angles to the axis of the main tube. These rims are greased and placed together, one on the other, and held together by wooden clamps. The glass tube in immediate connection with the zinc tube is also firmly filled with the soil sample, while the second tube is only partly filled, so that any settling which may take place in the soil on the addition of water may still find the first glass tube full of the sample. The empty part of the upper glass tube is now filled with water and additional quantities of water are added from time to time until the soil is saturated. In order to be able to observe when this takes place there is a slit at the lower end of the zinc tube which is closed with a piece of glass. This slit should be about two centimeters broad and ten centimeters long. The lower end of the zinc tube is set on a glass plate to prevent evaporation. As soon as the water shows itself at the lower end of the zinc tube, the excess of water in the upper glass tube is at once removed by a pipette and a stopper inserted through which a glass tube passes drawn out into a fine point above. The object of this is to avoid evaporation on the upper surface. The apparatus is then left at rest for thirty-six hours. At the end of this time the clamps are removed and the column of moist earth cut with a piece of platinum foil, and the two ends of the glass tube, next to the zinc tube, covered with glass plates. It is then weighed and the weight of moist earth determined by deducting the weight of the tube and its glass covers. The moist earth is carefully removed to a large porcelain dish and dried at 100°. Before weighing it is allowed to stand twenty-four hours in the air. The data obtained are used to calculate the water content to volume per cent. The volume of the glass tubes should be determined by careful calibration. =151. Method of Heinrich.=[106]—The soil to the depth turned by the plow is dug out and in the hole a lead vessel without bottom, twenty centimeters in diameter and forty centimeters high, is placed. The soil is then thrown back around and outside the lead vessel until the latter appears buried in the fragments. The rest of the soil is passed into the lead vessel, through a sieve having four meshes to the centimeter, using for this purpose enough water to thoroughly moisten it. Care should be taken not to use enough water to cause any separation of the fine from the coarse particles. By this process all coarse stones, sticks, etc., are separated. In sandy soils the flask is left for a few hours while in clay soils a much longer time is necessary. When the excess of water has disappeared the lead cylinder is removed, and a piece cut out of the center of it placed in a weighed drying flask and dried at 100°. =152. Effect of Pressure on Water Capacity.=[107]—The increasing capacity of soil to hold water developed by shaking or pressure, is determined by Henrici in the following way: Into a glass cylinder of twenty millimeters internal diameter are poured twenty cubic centimeters of water. A given quantity of soil is next added, and after standing until thoroughly saturated, the residual water is measured by pouring off, or better, by graduations on the side of the tube. The increase in the volume of the clear water is also measured, after shaking, in the same way. The data of a determination made as above described follow: Water in cylinder 30 cubic centimeters. Water and saturated soil 40 „ „ Volume of unsaturated soil = e = 10 „ „ Volume of saturated soil = e + w = 20.5 „ „ Water contained therein = w = 10.5 „ „ By repeated shaking the volume of e + w, the content of w therein, and the relative values of e/w were found to be as follows: Cubic Cubic Cubic Cubic centimeters. centimeters. centimeters. centimeters. e + w 20.5 16.0 15.7 15.0 w 10.5 6.0 5.7 5.0 ───────────────────────────────────────────────────────── w/e 1.05 0.60 0.57 0.50 If e′ represent the volume of the saturated soil then e′ = e + w, and this gives the relation to the volume of dry earth represented by the equation e′/e = 1 + w/e. This indicates that the relative volume of the saturated soil is equal to unity increased by the relative content of water. =153. Coefficient of Evaporation.=—At an ordinary room temperature in the shade, samples of soil, if they are subjected to experiment in tolerably thin layers have nearly an equal coefficient of evaporation. That is, the absolute quantity of water evaporated in a given time is almost entirely conditioned upon the magnitude of the surface exposed and the temperature of the surrounding air. Only when exposed in conditions as nearly as possible natural in thin layers to the action of the sunlight and shade do the soils show their peculiarities in respect of the evaporation of moisture. In order to see these peculiarities, samples of soil which have been previously examined must be subjected to examination at the same time with the soil whose properties are to be determined. The zinc box, before described, should be protected with a well fitting cover of thick paper, and the different samples of soil which are to be tested placed therein. This should now be placed in a wooden box, the top of which is exactly even with the top of the zinc vessel. This box containing the vessel should be exposed to the sunlight. After twenty-four hours the zinc boxes can be taken away from position and their loss in moisture determined, and these weighings, according to the condition of the atmosphere, can be continued from fourteen days to three weeks, the temperature of the air of course being carefully determined at each time. At first, all the different soils being saturated with moisture, it will be observed that the loss of moisture is proportionately the same for all. Soon, however, the rapidity of the evaporation in the samples of soil rich in humus and clay will be decreased as compared with the sandy soils, and in general, those which possess a high capillary power capable of bringing the moisture rapidly from the deeper layers to the surface. There soon comes a point when the difference in evaporation is at its greatest; and then there will be a gradual diminution until the samples lose no further moisture. This point, for the different soils, can be determined by frequent weighings of the vessel. =154. Determination of Capillary Attraction.=—Long glass tubes graduated in centimeters may be used for this determination, or plain tubes so arranged as to admit of easy measurements with a rule. The tubes may be from one to two centimeters internal diameter and about one meter long. The fine earth should be evenly filled in little by little, with gentle jolting. The lower end of each tube, before filling, is closed with a piece of linen. The tubes, after filling, are supported in an upright position by a frame AE, Fig. 19, in a vessel B containing water in which the linen covered ends D dip to the depth of two centimeters. The height of the water in the several tubes should be read or measured at stated intervals. The water contained in the supply vessel should be kept at a constant height by a Mariotte bottle. FIGURE 19. APPARATUS TO SHOW CAPILLARY ATTRACTION OF SOILS FOR WATER. ] The observations may be discontinued after one hundred and twenty hours, but even then the water will not have reached its maximum height. It is recommended by some experimenters to cut the tubes, after the above determination is completed, into pieces ten centimeters in length, and to determine the per cent of water in each portion. =155. Statement of Results.=—The following table illustrates a convenient method of tabulating the observed data as given by König.[108] Number of sample 1 2 3 4 5 6 ─────────────────────────────────────────────────────────────────────── Height of 24 hours. 27.3 38.0 16.7 36.4 8.0 28.8 centimeters. moisture column after: „ 48 „ 35.9 50.8 24.5 49.2 11.9 40.5 „ „ 72 „ 41.5 59.5 30.0 57.9 15.2 49.1 „ „ 96 „ 44.4 66.2 33.5 63.8 17.5 55.2 „ „ 120 „ 46.7 70.0 36.3 68.5 19.2 60.5 „ =156. Inverse Capillarity.=—In tubes filled with fine earth, as described in paragraph =154=, water is quickly poured, the same quantity into each tube of the same diameter, or such quantities in tubes of different diameters as would form a water column of the same depth over the surface of the sample. The rate at which the water column descends in each tube, the time of the disappearance of the water at the surface and the final depth to which it reaches, are the data to be entered. =157. Statement of Results.=—The points to be observed in the determination of inverse capillarity are the number of hours required for the total absorption of a column of water of a given height, the depth of the moisture column at that moment, and the total depth to which the moisture column finally reaches. The data of observations with six samples with a water column four centimeters high are given by König[109] as follows: Number of sample 1 2 3 4 5 6 ───────────────────────────────────────────────────────────────────────── Number of hours required for water to disappear 4.3 1.8 10.3 3.0 21.0 4.3 Depth of moisture at time of disappearance of water 11.0 12.0 11.4 13.3 11.7 12.0 centimeters. Total depth of moisture 13.0 18.1 13.0 19.0 12.0 16.5 „ =158. Determination of the Coefficient of Evaporation.=—The coefficient of evaporation is the number of milligrams of water evaporated from a square centimeter of soil surface in a given unit of time. It is evident that this number will vary with the physical state of the soil, the velocity of the wind, the saturation of the air with aqueous vapor and the temperature. In all statements of analyses these factors should appear. The process may be carried on first (a) with soil samples kept continually saturated with water and (b) with samples in which the water is allowed to gradually dry out. _Method a._—The determination may be made in the shade or sunlight. _In the Shade._—A zinc cylinder (Z Fig. 20), fifteen centimeters in diameter and 7.5 centimeters high, with a rim one centimeter wide and one centimeter from top, is covered at one end with linen or cotton cloth and filled with fine earth, with gentle jolting, until even with the top. It is then placed in a zinc holder H, into the circular opening of which it snugly fits as in A. This holder is twenty centimeters in diameter and 7.5 centimeters deep. It has an opening at O through which water can be added until it is filled so as to wet the bottom of Z when in place. As the water is absorbed by the soil more is added and, the top being covered, the apparatus is allowed to stand for twenty-four hours. At the end of this time the soil in the zinc cylinder is saturated with water to the fullest capillary extent. The whole apparatus, after putting a stopper in O, is now weighed on a large analytical balance and placed in an open room, with free-air circulation, for twenty-four hours. At the end of this time it is again weighed and the loss of weight calculated to milligrams per square centimeter. Where large and delicate balances can not be had, the apparatus can be constructed on a smaller scale suitable for use with a balance of the ordinary size. _In the Sunlight._—The apparatus described above is enclosed in a wooden box having a circular opening the size of the soil-zinc cylinder. In the determination of the rate of evaporation, the apparatus, charged and weighed as above described, is exposed to the sun for a given period of time, say one hour. On the second weighing the loss represents the water evaporated. The time of year, time of day, velocity of wind and temperature, and degree of saturation of the air with aqueous vapor, should be noted. The data obtained can then be calculated to milligrams of water per square centimeter of surface for the unit of time. _Method b._—As in method a the determination may be made in the shade or in the sunlight. The rate of evaporation is, in this method, a diminishing one and depends largely on the reserve store of water in the sample at any given moment. The same piece of apparatus may be used as in the determinations just described. After charging the sample with moisture all excess of water in the outer zinc vessel is removed and the rate of evaporation determined by exposure in an open room or in the sunlight, as is done in the operations already described. _Alternate Method._—The zinc cylinders used in determining saturation coefficient, paragraph =145=, may also be employed in determining the rate of evaporation. Each cylinder should be wrapped with heavy paper or placed in a thick cardboard receptacle, and all placed in a wooden box, the cover of which is provided with circular perforations, just admitting the tops of the cylinders, which should be flush with the upper surface of the cover. Arranged in this way the cylinders previously weighed are exposed in the shade or to direct sunlight and reweighed after a stated interval. On account of the small surface here exposed in comparison with the total quantity of soil and moisture it is recommended to weigh the cylinders once only in twenty-four hours. The weighings may be continued for a fortnight or even a month. In soils fully saturated with water the rate of evaporation is at first nearly the same on account of the surface being practically that of water alone. As the evaporation continues, however, the rate changes markedly with the character of the soil. =159. Rapid Method of Wolff.=—In order to expose a larger surface to evaporation and to secure the results in a shorter period of time, Wolff[110] fills square boxes, having wire-gauze bottoms, with fine earth, and after saturating with moisture weighs and suspends them in the open air. The wire-gauze bottoms are previously covered with filter paper to prevent loss of soil. FIGURE 20. APPARATUS FOR DETERMINING COEFFICIENT OF EVAPORATION. ] =160. Estimation of Water Given up in a Water-Free Atmosphere.=—The air-dried sample, in quantities of from five to ten grams in a thin layer on glass, is placed over a vessel containing strong sulfuric acid. It is then placed on a ground glass plate and covered with a bell jar. The sample is weighed at intervals of five days until the weight is practically constant. This method is valuable in giving the actual hygroscopic power of a soil depending on its structure alone. =161. Estimation of the Porosity of the Soil for the Passage of Gases.=—Some further notion of the physical state of the soil known as porosity, may also be derived by a study of the rate at which it will admit of the transmission of gases. A method for estimating this has been devised by Ammon.[111] Air is compressed in two gas holders by means of a column of water of proper height to give the pressure required. The tubes through which the air passes out of the gas holders are each furnished with a stop-cock and united with a glass tube having a side tube set in at right angles for carrying off the air. The use of two holders makes it possible to carry on the experiment as long as may be desired, one holder being filled with air while the other is emptying. The common conducting tube is joined with a meter which is capable of measuring, to 0.01, the volume of air passing through it. The pressure is regulated by means of the stop-cocks. The air passing from the meter is received in a drying tube filled with calcium chlorid. From the drying tube the air enters a drying flask filled below with concentrated sulfuric acid and above with pumice stone saturated therewith. Next the dried air passes through a worm, eight meters long, surrounded with water at a given temperature. The dried air of known temperature next enters the experimental tube. This tube is made of sheet zinc 125 centimeters in length and five centimeters in internal diameter. It is placed in an upright position, and about six centimeters from its upper end carries a small tube at right angles to the main one for connection with a water-filled manometer. The upper and lower ends of the tube are closed with perforated rubber stoppers carrying tubes for the entrance and exit of the air. In the inside of the zinc tube are found two close-fitting but movable disks, of the finest brass wire gauze, between which the material to be experimented upon is held. The layer of fine soil is held between these disks and may be of such a depth as is required for the proper progress of the experiment. With soils of firm texture opposing a great resistance to the passage of the air the column of earth tested should be shorter than with light and very permeable soils. The experimental tube is surrounded with a water jacket, which may also be made of sheet zinc, carrying small tubes directed upwards for holding thermometers. The water jacket should be kept at the same temperature as the air which is used in the experiment. The process of filling the tube, the amount of pressure to be used and the air and soil temperature, will naturally vary in different determinations. The volume of air at a given pressure and temperature which passes a column of soil of a given length in a unit of time will give the coefficient of permeability. =162. Determination of Permeability in the Open Field.=—A method for determining the rate of transmission of a gas through the soil in the field has been devised by Heinrich.[112] A box C (Fig. 21) is made of strong sheet iron and has an opening below, ten centimeters square, and a height of about twenty centimeters. At exactly ten centimeters from the bottom, the box has a rim at right angles to its length so that it can be placed only ten centimeters deep in the soil. The box holds a volume of earth equal to 1,000 cubic centimeters. FIGURE 21. METHOD OF HEINRICH. ] The part of the box above ground is connected with the bottle B by a glass tube as indicated in the figure. The bottle B should have a capacity of about ten liters. The air in B is forced out through C by water running in from the supply A and the pressure in B is recorded by the manometer D. The experiment should be tried on a soil thoroughly moist. In measuring the pressure in B the water pressure should be cut off by the pinch-cock between A and B, and the pressure on the manometer observed after the lapse of one to two minutes. MOVEMENT OF WATER THROUGH SOILS: LYSIMETRY. =163. Porosity in Relation to Water Movement.=—The intimate relation which water movement in a soil bears to fertility makes highly important the analytical study of this feature of porosity. A soil deficient in plant food, in so far as chemical analysis is concerned, will produce far better crops when the flow of moisture is favorable than a highly fertile soil in which the water may be in deficiency or excess. Aside from the actual rain-fall the texture of the soil, in other words its porosity, is the most important factor in determining the proper supply of moisture to the rootlets of plants. Even where the rain-fall is little, a properly porous soil in contact with a moist subsoil will furnish the moisture necessary to plant growth. This fact is well illustrated by the beet fields in Chino Valley, California. In this locality most excellent crops of sugar beets are produced without irrigation and almost without rain. =164. Methods of Water Movement=—The translocation of soil water is occasioned in at least two ways; namely, 1. By changing the porosity of a given stratum of soil. 2. By changing the amount of water a given stratum contains. The following experiment by King[113] illustrates a convenient method of studying this movement of water: On a rich fallow ground of light clay soil, underlaid at a depth of eighteen inches by a medium-grained sand, water, to the amount of two pounds per square foot on an area of eight by eight feet, was slowly added with a sprinkler, samples of soil having been previously taken in six-inch sections down to a depth of three feet. The samples were taken along a diagonal of the square under experiment and one foot apart. The middle sample of the line being from the center of the area. The sampling and wetting occurred between one and three P. M., on July 22, and on the evening of the 23 a corresponding series of samples was taken along a line parallel to the first but eight inches distant. The changes in the percentages of water in the soil are given in the following table, showing the translocation of water in soil due to wetting the surface: PER CENT OF WATER. DIFFERENCE. Inches. Before After In per cent. In pounds per wetting. wetting. cu. ft. 0–6 14.00 22.23 +8.23 +2.873 6–12 15.14 15.71 +0.57 +0.199 12–18 16.23 15.75 –0.48 –0.213 18–24 17.70 16.92 –0.78 –0.347 24–30 16.76 14.41 –2.35 –1.032 30–36 15.51 15.21 –0.30 –0.132 The figures given in the last column of the table are computed from the absolute dry weights of the upper three feet of soil as determined in a locality some rods from the place of experiment, and are therefore only approximations, but the error due to this cause is certainly small. It will be seen that while only two pounds of water to the square foot were added to the surface, the upper six inches contained 2.87 pounds per square foot more than before the water was added, and the second six inches contained 0.199 pound more, and this too in the face of the fact that the evaporation per square foot from a tray sitting on a pair of scales close by, was 0.428 pound during the interval under consideration. Similar experiments were made by taking the samples of soil at 5.30 P. M. in one-foot sections down to four feet, at four equally distant places along the diagonal of a square, six by six feet, and having the ground sprinkled. At the same time four similar sets of samples were taken on lines vertical to each of the sides of the square but four feet distant from them. The amount of water the soil contained was then determined, and at 11.30 A. M., nineteen hours later, another series of samples was taken at points about four inches distant from the last and the amount of water determined with the result given below. TRANSLATION OF WATER OCCASIONED BY WETTING THE SURFACE. ─────────────┬─────────────────────────────────────────────────────── Depth of │ samples. │ WET AREA. ─────────────┼───────────────────────────╥─────────────────────────── „ │ Before wetting. ║ After wetting. ─────────────┼─────────────┬─────────────╫─────────────┬───────────── „ │ │ Pounds of ║ │ Pounds of │ Per cent of │ water per ║ Per cent of │ water per │ water. │ cubic foot. ║ water. │ cubic foot. ─────────────┼─────────────┼─────────────╫─────────────┼───────────── 0–12 inches │ 16.86│ 11.78║ 20.15│ 14.06 12–24 „ │ 17.76│ 15.79║ 19.71│ 17.52 24–36 „ │ 16.76│ 14.73║ 17.72│ 15.58 36–48 „ │ 15.01│ 14.03║ 16.47│ 15.40 ─────────────┼─────────────┼─────────────╫─────────────┼───────────── Averages │ 16.59│ 14.08║ 18.51│ 15.64 │ │ ║ │ Total amount │ │ ║ │ of water │ │ 56.33║ │ 62.56 Amount of │ │ ║ │ change │ │ ║ │ +6.23 ─────────────┴─────────────┴─────────────╨─────────────┴───────────── ─────────────┬─────────────────────────────────────────────────────── Depth of │ samples. │ AREA NOT WET. ─────────────┼───────────────────────────╥─────────────────────────── „ │ First samples. ║ Second samples. ─────────────┼─────────────┬─────────────╫─────────────┬───────────── „ │ │ Pounds of ║ │ Pounds of │ Per cent of │ water per ║ Per cent of │ water per │ water. │ cubic foot. ║ water. │ cubic foot. ─────────────┼─────────────┼─────────────╫─────────────┼───────────── 0–12 inches │ 17.72│ 12.38║ 18.27│ 12.75 12–24 „ │ 19.18│ 17.05║ 19.94│ 17.72 24–36 „ │ 16.97│ 14.92║ 17.52│ 15.40 36–48 „ │ 15.49│ 14.48║ 15.16│ 14.17 ─────────────┼─────────────┼─────────────╫─────────────┼───────────── Averages │ 17.34│ 14.71║ 17.71│ 15.01 │ │ ║ │ Total amount │ │ ║ │ of water │ │ 58.83║ │ 60.04 Amount of │ │ ║ │ change │ │ ║ │ +1.21 ─────────────┴─────────────┴─────────────╨─────────────┴───────────── The above data show sufficiently well the method of investigation to be pursued in studies of this kind. =165. Capillary Movement of Water.=—The method of investigation proposed by King[114] consists in taking samples of soil at intervals of one, two, three, or four feet in depth, and determining the amount of moisture in each in connection with the amount of rain-fall during the period. The quantity of water contained in a given soil, at various depths and on different dates, is shown in the following table: Depth in Date. Per cent Pounds per Increase or decrease. feet. water. cubic foot. Pounds per cubic foot. 1 March 8th 24.33 16.98 1 April 18th 22.37 15.61 –1.37 2 March 8th 15.80 14.05 2 April 18th 21.64 19.24 +5.19 3 March 8th 11.16 9.81 3 April 18th 16.24 14.27 +4.46 4 March 8th 7.87 7.36 4 April 18th 11.19 10.46 +3.10 The rain-fall during the interval was 4.18 inches, equal to 21.77 pounds per square foot. =166. Lateral Capillary Flow.=—To determine the lateral capillary flow of water in a soil the following method, used by King[115] may be employed: A zinc lined tray, six by six feet in area and eight inches deep, is filled with a soil well packed. In one corner of this tray a section of five inches of unglazed drainage tile, having its lower end broken and jagged, is set and the dirt well filled in round it. By means of a Mariotte bottle water is constantly maintained in the bottom of this tile, three-quarters of an inch deep, so that it will flow laterally by capillary action into the adjacent soil, the object being to determine the extent and rate of capillary flow laterally. The water content of the soil is determined at the time of starting the experiment, on the circumferences of circles described with the tile as a center, the distance between the circles being one foot. At stated periods, usually at intervals of one day, the content of moisture is again determined at the same points. The investigations show that the lateral movement of water in the soil is not rapid enough to extend much beyond three feet in thirty-one days, for beyond that distance the soil was found to be drier than at the beginning of the experiment. A record is to be kept of the amount of water delivered to the soil by weighing the supply bottle at intervals, and the rates given at which the soil takes up the water in grams per hour and pounds per day. Also the amount of flow per square foot of soil section together with the mean daily evaporation should be noted. The mean flow per foot of soil section is computed on the assumption that the outer face of the zone of completely saturated soil is the delivering surface. In King’s work this point, as nearly as could be determined, was twelve inches from the corner of the tray and hence the figures at best can only be regarded as approximations. The method of stating results is shown in the following table: SHOWING THE RATE OF LATERAL CAPILLARY FLOW OF WATER IN CLAY LOAM. Date. No. Total mean, Total mean, Mean daily flow Mean daily of hourly flow, daily flow, per square evaporation, days. grams. pounds. foot, pounds. pounds. Jan. 28 to 5 70.70 3.73 2.38 Feb. 2 Feb. 2–7 5 85.98 4.54 2.91 Feb. 7–12 5 79.33 4.19 2.64 Feb. 12–17 5 79.41 4.19 2.64 0.598 Feb. 17–22 5 70.79 3.74 2.38 0.534 Feb. 22–28 6 59.89 3.16 2.01 0.451 Feb. 28 to 6 60.74 3.21 2.04 0.458 March 6 Mar. 6–13 7 60.37 3.14 2.00 0.448 ─────────────────────────────────────────────────────────────────────── Means 2.38 0.498 From this table it will be seen that the flow of water in the soil varied in rate, being slower during the first five days than in the succeeding fifteen days. After twenty days the flow dropped again to the beginning rate and then fell below, but remained quite constant during the following nineteen days. For the sake of uniformity in units of measure the daily quantity of flow should be given in kilograms when the hourly flow is given in grams. =167. Causes of Water Movement in the Soil.=—The movement of water in a soil as explained by Whitney[116] is due to two forces, _viz._, gravitation and surface tension. The force of gravitation in a given locality is always uniform, both in direction and magnitude per unit volume of water. Surface tension is the tendency of any exposed water surface to pull itself together. It may act in any direction, according to circumstances, and may thus sometimes help and sometimes antagonize the force of gravitation. According to the law of surface tension any particle of moisture tends to assume the smallest possible area. This tendency is a constant definite force per unit of surface at a given temperature. In the soil this constant strain on the free surface of water particles serves, in a high degree, to move them from place to place, in harmony with the requirements of the different portions of the field. When a soil is only slightly moist the water clings to its grains in the form of a thin film. When these soil particles are brought together the films of water surrounding them unite, one surface being in contact with the soil particles and the other exposed to the air. If more water enter the soil the film thickens until finally, when the point of saturation is reached, all the space between the soil particles becomes filled with water, and surface tension within the soil is thus reduced to zero. Gravity then alone acts on the water and with a maximum force. In a cubic foot of ordinary soil the total surface of the soil particles will be at least 50,000 square feet. It follows that when the soil is only slightly moist the exposed water surface of the films surrounding the soil particles approximates that of the particles themselves. If such a mass of slightly moist soil be brought in contact with a like mass saturated with water, the films of water at the point of contact will begin to thicken in the nearly dry soil at the expense of the water content of the saturated mass. The water will thus be moved in any direction. During evaporation the surface tension near the surface of the soil is increased, and water is thus drawn from below. In like manner, when rain falls on a somewhat dry soil, the surface tension is diminished and the greater surface tension below pulls the moisture down even when gravitation would not be sufficient for that purpose. Certain fertilizers have the faculty of modifying surface tension and thus change the power of the soil in its attraction for moisture. In this way such fertilizers act favorably on plant growth, both by providing plant food and by supplying needed moisture. =168. Surface Tension of Fertilizers.=—Whitney gives the following data in respect of the surface tension of aqueous solutions of some of the more common fertilizing materials. It is expressed in gram meters per square meter, _i. e._, on a square meter of liquid surface there is sufficient energy to lift the given number of grams to the height of one meter. SURFACE TENSION OF VARIOUS FERTILIZING SOLUTIONS. Solution of— Specific gravity. Gram meters per square meter. Salt 1.070 7.975 Kainite 1.053 7.900 Lime 1.002 7.696 Water 1.000 7.668 Acid phosphate 1.005 7.656 Plaster 1.000 7.638 Ammonia 0.960 6.869 Urine 1.026 6.615 Magnesium chlorid 1.1000 7.964 Basic slag 1.0012 7.890 Marl 1.0013 7.855 Potassium chlorid 1.1000 7.853 Ammonium sulfate 1.1000 7.834 Dried blood 1.0001 7.764 Ground bone 1.0007 7.749 Sodium nitrate 1.1000 7.730 Sodium sulfate 1.1000 7.730 Wood ashes 1.0038 7.674 Potassium nitrate 1.1000 7.661 Potassium sulfate 1.0830 7.658 Ammonium nitrate 1.1000 7.656 Dried fish 1.0026 7.594 Stable manure 1.0013 7.464 Cotton-seed meal 1.0054 6.534 Tankage 1.0169 4.844 Cotton seed 1.0070 4.788 SURFACE TENSION OF SOIL EXTRACTS. Kind of Soil. Specific gravity. Surface tension. Kentucky blue grass 1.000 7.244 Triassic red sandstone 1.000 7.244 Wheat soil 1.000 7.098 Garden soil 1.000 7.089 =169. Method of Estimating Surface Tension.=—The determination of surface tension is made by measuring the rise of the liquid in a capillary tube. A short piece of thermometer tubing is used, the diameter of the bore being determined by careful microscopic measurements with a micrometer eyepiece. The diameter of the tube should be about 0.5578 millimeter. The tube is very thoroughly cleaned after each observation, or set of observations, with a strong caustic potash solution, and, after washing, is allowed to stand for some time in a saturated solution of potassium bichromate in strong sulfuric acid. The height of the rise in the capillary tube is measured with a cathetometer. The following formula is used for the calculation of the results: T = (_h d_ ω)/(4 cos. _a_) Where T is the surface tension, _d_ is the diameter of the tube in centimeters; _h_ the height to which the liquid rises in the capillary tube in centimeters; ω is the specific gravity of the solution; and 4 cos. _a_ refers to the angle of the liquid with the sides of the glass tube. For a tube of the size given above, 5° 24′ is the value of this edge angle. In regard to saline solutions, Quincke[117] says, that the edge angle appears to increase a little with augmenting concentration of the saline solution, but otherwise to differ only inconsiderably from the edge angle of pure water. =170. Effect of the Solutions on Surface Tension.=—The mineral fertilizers, as a rule, increase the surface tension of water, while organic matters in solution decrease it. But it must not be forgotten in this connection that but little of the organic matter in the fertilizers employed for the experiment passes into solution. Moreover, with these substances, the accuracy of the work is impaired somewhat by the increased viscosity. In general, the results of the experiment are in harmony with the well-known effect of magnesium, sodium, and potassium chlorids, and sodium nitrate, to make the soil more moist in dry weather, and the opposite effect produced by the application of organic matter. =171. Method of Preparing Soil Extracts.=—The soil extracts used in determining the surface tension, as given in the above table, are prepared as follows: Ten grams of the soil are rubbed up with fifteen to twenty cubic centimeters of distilled water and allowed to stand for twenty-four hours with frequent stirring. Any fine particles not removable by a filter are neglected, although they may give a turbid appearance to the solution. =172. Lysimetry.=—The process of measuring the capacity of a soil to permit the passage of water and of collecting and determining the amount of flow and determining soluble matters therein is known as lysimetry. In general, the rate at which water will pass through a soil depends on the fineness and approximation of its particles. Water will pass through coarse sand almost as rapidly as through a tube, while a fine clay may be almost impervious. The study of the phenomena of filtration through soil, and the methods of quantitatively estimating them, are therefore closely related to porosity. Two cases are to be considered, _viz._: First, percolation through samples of soil prepared for analysis, and second, the passage of the water through soil _in situ_, whether it be virgin or cultivated. The determination of the rate of flow through a soil in laboratory samples, gives valuable information in respect of its physical properties, while the same determination made on the soil _in situ_, has practical relations to the supply of moisture, to growing plants, and the waste of valuable plant food in the drainage waters. The determination of the rate of flow of water through a small sample, disturbed as little as possible in its natural condition, is classed with the first divisions of the work, inasmuch as the removal of a sample of soil from a field, and its transfer to the laboratory, subjects it to artificial conditions, even if its texture be but little disturbed by the removal. =173. Calculation of the Relative Rate of Flow of Water Through Soils.=—There will evidently be one space, or opening, into the soil for every surface grain, as pointed out by Whitney,[118] and the approximate number of grains, or of openings, on a unit area of surface may be found by the following formula: N = (√((M × W)/(V))^⅔ where N is the number of grains, or openings, on one square centimeter of surface, M is the approximate number of grains in one gram of soil, W is the weight of soil, V is the total volume of the soil grains and the empty space. If the grains are assumed to be symmetrically arranged and the spaces between them cylindrical in form, the radii of the spaces can be found by the following formula: _r_ = √(V₁)/(πNL) where _r_ is the radius of a single space, V is the total volume of the empty space, N is the number of grains or spaces on one square centimeter of surface, and L is the depth of the soil. If the space within the soil is completely filled with water the relative rate of flow of water through the soil will be according to the fourth power of the radius of a single space multiplied by the number of spaces on the unit area of surface, as shown by the following formula: T₁ = (N(_r_)⁴T)/(N₁(_r_₁)⁴) where N-N₁ are the numbers of spaces, and _r_-_r_₁ are the radii of single spaces in the respective soils, and T-T₁ the times required for a unit volume of water to flow through the soils under the same head or pressure. The space within the soil is rarely filled with water in agricultural lands, and the most favorable amount of water for the soil to hold, as Hellriegel and others have shown, is from thirty to fifty per cent of the total amount of water the soil can hold if all the space within it were filled. If the space within the soil be only partly filled with water, as in most arable lands, the water will move in a thin film surrounding the soil grains and according to the fourth power of the thickness of the film. The mean thickness of the film surrounding the soil grains may be theoretically determined by the following formula, which is based on the conception that the film is cylindrical and of uniform size throughout: _t_ = _r_(1 − √(_s_)/(_s_ + _p_)) where _s_ is the per cent by weight of water which the soil will hold when the empty space is filled with water, _p_ the per cent of water actually contained in the soil, _r_ the radius of a single space, and _t_ the mean thickness of the film surrounding the soil grains. The relative rate of flow of water through the soils will then be according to the following formula: T₁ = (N(_t_)⁴T)/(N₁(_t_)₁⁴)) It must be remembered that these formulæ give only approximate and comparative values for comparing one soil with another. The structure of the soil is altogether too intricate to expect ever to obtain absolute values. If the observed rate of flow varies widely from the relative rate calculated from the mechanical analysis, it will indicate a difference in the arrangement of the soil grains, or in the amount or condition of the organic matter in the soils. In the older agricultural regions of the United States, south of the influence of the glacial action, the great soil areas appear to have sensibly similar arrangements of the soil grains, and sensibly uniform conditions of organic matter, save where these have been modified by local conditions. =174. Measurement of Rate of Percolation in a Soil Sample.=—In order to measure the power of the soil for permitting the passage of water, a box, about twenty-five centimeters high and having a cross section of about three centimeters square, is used. Below, this box has a funnel-shaped end with a narrow outlet tube, which at its lower end is closed with cotton, in such a way that a portion of the cotton extends through the stem of the funnel. A little coarse quartz sand is scattered over the cotton and afterwards the funnel part of the apparatus filled with it. The sand and the cotton are saturated with water and the apparatus weighed. The box is then filled with the fine sample of earth, with light tapping, until the depth of earth has reached about sixteen centimeters. The apparatus, after the addition of the air-dried earth, is again weighed to determine the amount of earth added, and the soil is then saturated by the careful addition of water. After the excess of water has run down the funnel, the total quantity of absorbed water is determined by reweighing the apparatus and the total water-holding power of the soil is determined. There is carefully added, without stirring up the surface of the soil, a column of water eight centimeters high, making in all from sixty to seventy grams. The time is observed until the water ceases to drip from the funnel. The dripping begins immediately after the water is poured on and ceases as soon as the liquid on the surface of the soil has completely disappeared. On the repetition of this operation a longer time for the passage of the water is almost always required than at the first time. The experiment, therefore, must be tried three or four times and the mean taken. =175. Method of Welitschowsky.=[119]—The soil is placed in the vessel _a_, Fig. 22, which is cylindrical in shape and five centimeters in diameter. The lower end of the cylinder is closed with a fine wire-gauze disk and the upper end is provided with an enlargement for the reception of the tube _b_, which is connected to _a_ with a wide rubber band. The lower end of the tube _b_ is also closed with a wire-gauze disk. These tubes may be conveniently made of sheet zinc. The tube _b_ carries on the side, at distances of ten centimeters, small tubes of fifteen millimeters diameter. On the opposite side it is provided with a glass tube set into a side tube near the bottom for the purpose of showing the height of the water. The side tube carrying the water meter is provided with a stop-cock as shown in the figure. FIGURE 22. METHOD OF WELITSCHOWSKY. ] In conducting the experiment, after the apparatus has been arranged as described, the small lateral tubes are, with one exception, closed with stoppers. On the open one, _d_, a rubber tube is fixed for the purpose of removing the water. The required water pressure is secured by taking the lateral opening corresponding to the pressure required. Water is introduced into the apparatus slowly through the glass tube _f_. The water rises to _d_ and then any excess flows off through _e_. By a proper regulation of the water supply the pressure is kept constant at _d_. The water flowing off through _a_ is collected by the funnel and delivered to graduated flasks where its quantity can be measured for any given unit of time. Since the rate of flow at first shows variations, the measurement should not be commenced until after the flow becomes constant. In general, the experiments should last ten hours, and, beginning with a water pressure of 100 centimeters, be repeated successively with pressures of eighty, sixty, forty, and twenty, centimeters, etc. In coarse soils, or with sand, one hour is long enough for the experiment. =176. Statement Of Results.=—In the following tables the results for ninety centimeters, seventy centimeters, etc., are calculated from the analytical data obtained for 100 centimeters, eighty centimeters, etc. MATERIAL—QUARTZ SAND. │ │ LITERS OF WATER PASSING IN TEN │ HOURS. No. Diameter of│ of sand │ Exp. particles │ Water in │pressure in Thickness of Soil Layer. mm. │ cm. 10 cm. 20 cm. 30 cm. 1. 0.01–0.71 │ 10 0.244 0.187 0.151 „ „ │ 20 0.282 0.198 0.154 „ „ │ 30 0.320 0.209 0.158 „ „ │ 40 0.358 0.220 0.161 „ „ │ 50 0.396 0.231 0.165 „ „ │ 60 0.434 0.242 0.168 „ „ │ 70 0.472 0.253 0.172 „ „ │ 80 0.510 0.264 0.175 „ „ │ 90 0.548 0.275 0.179 „ „ │ 100 0.586 0.286 0.182 2. 0.071–0.114│ 10 2.194 1.724 1.425 „ „ │ 20 2.898 2.012 1.578 „ „ │ 30 3.602 2.300 1.731 „ „ │ 40 4.306 2.588 1.884 „ „ │ 50 5.010 2.876 2.037 „ „ │ 60 5.714 3.164 2.190 „ „ │ 70 6.418 3.452 2.343 „ „ │ 80 7.122 3.740 2.496 „ „ │ 90 7.826 4.028 2.649 „ „ │ 100 8.530 4.316 2.802 Similar sets of data have been collected with powdered limestone, clay and humus. The general conclusions from the experiments are as follows: 1. Clay (kaolin) and humus (peat) are almost impermeable for water, and fine quartz and limestone dust are also very impermeable. 2. The permeability of a soil for water increases as the particles of the soil increase in size, and when particles of different sizes are mixed together the permeability approaches that of the finer particles. 3. The quantity of water passing through a given thickness of soil increases with the water pressure but is not proportional thereto, increasing less rapidly than the pressure. 4. The quantity of water passing under a given pressure is inversely proportional to the thickness of the soil layer when the particles are very fine and the pressure high. =177. Method of Whitney.=—To determine the permeability of the soil or subsoil to water or air, in its natural position in the field, the following method, due to Whitney, can be recommended: A hole should be dug, and the soil and subsoil on one side removed to the depth at which the observation is to be made. A column of the soil or subsoil, two inches or more square, and four or five inches deep, is then to be carved out with a broad bladed knife, or a small saw can be conveniently used for cutting this out. A glass or metal frame, a little larger than the sample and three or four inches deep, is slipped over the column of soil, and melted paraffin is run in slowly to fill up the space between the soil and the frame. The soil is then struck off even with the top and bottom of the frame, preferably with a saw, or at any rate taking care not to smooth it over with a knife, which would disturb the surface and affect the rate of flow. The frame is then placed upon some coarse sand or gravel, contained in a funnel, to prevent the soil from falling out and to provide good drainage for the water to pass through. Another similar frame can then be placed on top and secured by a wide rubber band. A little coarse sand, which has been thoroughly washed and dried, is then placed on the soil, and water carefully poured on until it is level with the top of the frame. When the water begins to drop from the funnel more water must be added to the top, so as to have the initial depth of water over the soil the same in all the experiments. A graduated glass is then pushed under the funnel, and the time noted which is required for a quantity of water to pass through the soil. The quantity usually taken for measurement is equivalent to one inch in depth over the soil surface. In taking the sample, root and worm-holes are to be avoided, and these are particularly troublesome in clay lands. =178. Measurement of Percolation through the Soil in Situ.=—If lateral translocation could be prevented, the measurement of the quantity of water descending in the soil through a given area would be a matter of simplicity. But to secure accurate results all lateral communication of a given body of soil with adjacent portions must be cut off. Various devices have been adopted to secure this result. An elaborate system of lysimetric measurements is illustrated by the apparatus erected by the Agricultural Experiment Station, of Indiana. The plan and section of the apparatus are shown in Fig. 23. Each lysimeter box, when finished, resembles somewhat a hogshead with one head out. The sides, however, are perfectly straight inside, having a slight thickening in the center, on the outside, for making them stronger. The sides and bottom of the apparatus are constructed of oak and lined with sheet copper carefully soldered so as to be water-tight. Six inches above, and parallel to the bottom of each of the boxes, is a perforated copper tube, which extends entirely across the lysimeter, and passing through one of the sides connects the box with an underground vault in which the observations are taken. These tubes give an outlet to the drainage water, as described further on. The lysimeters are made of any required depth, the two which are shown in section being three and two-thirds and six and two-thirds feet deep, respectively. The following method is employed for filling them with soil: There are first placed in the bottom of each lysimeter six inches of fine sand, sifted and washed, which fills them up to the level of the drainage tubes. The lysimeters are then filled with fine, sifted surface soil, to the depth of three and six feet, respectively, making a complete pair of lysimeters, and leaving two inches of the lysimeter boxes projecting above the surface of the soil so that each one will receive exactly its proper share of the rain-fall. The lysimeters of the other pair, which are the same size as the first, are filled in a different way. The lysimeters are first constructed and placed over vertical columns of soil _in situ_, which are obtained by digging away all the surrounding soil and leaving the columns standing. The shorter lysimeter is sunk in this way to within two inches of its entire length. It is then tipped over carrying the column of soil with it. Six inches of the subsoil are then removed, when the drainage tube and sand are put in, as in the first pair, and the bottom of the tube soldered in place. The lysimeter is thus filled with the natural soil in place. The longer box is in the same way filled, as far as possible, with the soil in place, but a gravelly nature of the soil may render it impossible to do the filling with a single column unbroken, so the gravel and sand from the lower portion of the soil are to be filled in separately. The drainage tube and bottom of sand are placed in the longer lysimeter in the same way as in the shorter. FIGURE 23. GROUND PLAN AND VERTICAL SECTION OF LYSIMETERS AND VAULTS SHOWING POSITION OF THE APPARATUS. 1, 1, 1, 1, Lysimeters. 2, 2, 2, 2, Receiving bottles. 3, 3, Supplying apparatus. 4, 4, Skylights. 5, 5, 5, 5, Wall of vault. 6, 6, Brick walls. 7, Entrance Steps. 8, Vault. ] The purpose of placing sand at the bottom of each lysimeter is to offer a porous stratum in which free water may collect and rise to the level of the perforated copper tube, which would prevent any further rise by conveying the surplus above into the vault as drainage water. The soil above the tube will therefore be constantly drained and the sand below constantly saturated, unless the water be drawn up by the capillary action of the soil as the result of evaporation from the surface. By means of a proper arrangement within the vault, of a kind of Mariotte’s bottle, the water may be caused to flow back through the drainage tube into the lysimeter to take the place of that lost by evaporation, and thus maintain the level of free water just below the drainage tube. The water flowing back to the lysimeter, and the amount of drainage water, are carefully measured by a system of graduated tubes. The lysimeters thus constructed represent tile-drained land; in one case the tile being three feet below the surface and in the other six feet below. The drainage waters collected in the receiving bottles can be measured and analyzed from time to time, as occasion may require, to determine the amount of plant food which is removed. =179. Improved Method of Deherain.=[120]—Deherain’s earlier experiments were made in pots containing about sixty kilos of soil. These vases serve very well for some kinds of plants, but there are other kinds which do not grow at all normally when their roots are imprisoned. For instance, in pots, even of the largest size, wheat is always poor, beets irregular, maize never acquires its full development, and the conclusions which can be drawn from the experiments can not be predicated of the action of the plant under conditions entirely normal. It is necessary therefore to carry on the work in an entirely different way, and to construct boxes so large as to make the conditions of growth entirely normal. The arrangement of these boxes is shown in Fig. 24. They are placed in a large trench, two meters wide, one meter deep, and forty meters long. There are twenty boxes in this trench, the upper surface of each containing four square meters area. The boxes are one meter deep, and therefore can contain four cubic meters of soil. The sides and bottoms of the boxes are made of iron lattice work, covered with a cement which renders them impervious to water. The bottom inclines from the sides towards the middle, and from the back to the front, thus forming a gutter which permits of the easy collection of the drainage. The drainage water is conveyed, by means of a pipe and a funnel, into a demijohn placed in the ditch in front of the apparatus, as shown in the figure. These receptacles stand in niches under the front of the cases, and are separated by the brick foundations. Access to them is gained by means of the inclined plane shown in the figure, and this plane permits the demijohns in which the drainage water is collected, to be removed with a wheelbarrow for the purpose of weighing. This apparatus is especially suitable for a study of the distribution of the nitrogen to the crop, the soil and the drainage waters. The loss in drainage waters of potash and phosphoric acid is insignificant in comparison with the loss in nitrogen. The cases having been placed in position they are filled with the natural soil, which is taken to the depth of one meter, in such a way that the relative positions of the soil and subsoil are not changed. While the soil is transferring to the cases it is carefully sampled in order to have a portion representing accurately the composition of both the soil and subsoil. These samples are subjected to analysis and the quantities of nitrogen, phosphoric acid, and potash contained therein carefully noted. One or two cases should be left without crop or fertilizer to determine the relations of the soil and subsoil to the rain-fall. Three or four cases should be kept free of vegetation and receive treatment with different fertilizer, in order to determine the influences of these on the deportment of the soil to rain-fall. The rest of the cases should be seeded with plants representing the predominant field culture of the locality, and some of them should be fertilized with the usual manures used in farm culture. FIGURE 24. DEHERAIN’S APPARATUS FOR COLLECTING DRAINAGE WATER. ] AUTHORITIES CITED IN PART THIRD. Footnote 70: Comptes rendus, Tome 112, p. 598. Footnote 71: Stockbridge, Rocks and Soils, p. 153. Footnote 72: Die Landwirtschaftlichen Versuchs-Stationen, Band 8, S. 40. Footnote 73: König, Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, S. 48. Footnote 74: Methods of Swedish Agricultural Chemists, translated for author by F. W. Woll. Footnote 75: Poggendorff’s Annalen, Fifth Series, Band 9, Ss. 102, et seq. Footnote 76: Pennsylvania Agricultural Experiment Station Report, for 1891, pp. 194, et seq. Footnote 77: Agricultural Science, Vol. 8, pp. 28, et seq. (Correction. For Fig. 13, second line from bottom of page 112, read Fig. 14.) Footnote 78: Haberland. Forschungen auf der Gebiete der Agricultur-Physik, 1878, S. 148. Footnote 79: Grundlagen zur Beurteilung der Ackerkrume, Weimar, 1882. Footnote 80: Vid. supra, 10. Footnote 81: These general principles are taken chiefly from a résumé of the subject by Prof. H. A. Huston. Indiana Agricultural Experiment Station, Bulletin 33, pp. 46, et seq. Footnote 82: Knop’s Agricultur Chemie, Abteil II. Footnote 83: Beiträge zur Frage der Bodenabsorption. Footnote 84: Henneberg’s Journal, 1859, S. 35. Footnote 85: Die Landwirtschaftlichen Versuchs-Stationen, Band 27, S. 107. Footnote 86: Die Bonitirung der Ackererde, S. 49. Footnote 87: Journal Chemical Society of London, 1868. Footnote 88: Landw. Central-Blatt, Band 11, S. 169. Footnote 89: bis Die Landwirtschaftlichen Versuchs-Stationen, Band 12, Ss. 21–50. Footnote 90: Jour. f. Landw., 1862, Band 3, Ss. 49–67. Footnote 91: Ann. d. Landw., Band 34, S. 319. Footnote 92: American Journal of Science, Vol. 14, p. 25. Footnote 93: bis (p. 122). Ms. communication to author. Footnote 94: Maryland Agricultural Experiment Station, Fourth Annual Report, p. 282. Footnote 95: Bulletin No. 4, U. S. Weather Bureau, p. 80. Footnote 96: bis (p. 125), Beiträge zur Agronomische Bodenuntersuchung, S. 31. Footnote 97: Zeitschrift für angewandte Chemie, 1889, S. 501. Footnote 98: Die Landwirtschaftlichen Versuchs-Stationen, Band 17, S. 85. Footnote 99: Ms. communication to author. Footnote 100: Proceedings of the Ninth Meeting of the Society for the Promotion of Agricultural Science, p. 51. Footnote 101: Rocks and Soils, pp. 155 et. seq. Footnote 102: Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 137. Footnote 103: Analyse du Sol, p. 13. Footnote 104: Landwirtschaftliche Jahrbücher, Band 3, Ss. 771. Footnote 105: Forschungen auf dem Gebiete der Agricultur-Physik, 1885, Ss. 177, et seq. Footnote 106: Vid. supra, S. 259. Footnote 107: Poggendorf, Annalen, Band 129, Ss. 437, et seq. Footnote 108: König, Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, S. 59. Footnote 109: Vid. 37, S. 60. Footnote 110: Landwirtschaftliche Jahrbücher, Band 2, S. 383. Footnote 111: Forschungen auf dem Gebiete der Agricultur-Physik, 1880, S. 218. Footnote 112: Beurteilung der Ackerkrume, S. 222. Footnote 113: Wisconsin Agricultural Experiment Station, Seventh Annual Report, pp. 134, et seq. Footnote 114: Vid. supra, pp. 139, et seq. Footnote 115: Wisconsin Agricultural Experiment Station, Seventh Annual Report, p. 145. Footnote 116: Bulletin No. 4, Weather Bureau, pp. 13, et seq. Footnote 117: Philosophical Magazine, 1878. Footnote 118: Weather Bureau, Bulletin No. 4. Footnote 119: Forschungen auf dem Gebiete der Agricultur-Physik, 1891, S. 11. Footnote 120: Annales Agronomiques, Tome 16, p. 337; Tome 17, p. 49; Tome 18, p. 237; Tome 19, p. 69. PART FOURTH. MECHANICAL ANALYSIS OF SOILS. THE FLOCCULATION OF SOIL PARTICLES. =180. Relation of Flocculation to Mechanical Analysis.=—The tendency of the fine particles of silt to form aggregates, which act as distinct particles of matter, is the chief difficulty connected with the separation of the soil into portions of equal hydraulic value by the silt method of analysis. This tendency has been discussed fully by Johnson[121] and Hilgard.[122] =181. Illustration of Flocculation.=—A sediment, consisting of particles of a hydraulic value, equal to one millimeter per second, is introduced into an ordinary conical elutriating tube placed vertically, in which the current of water entering below performs all the stirring which the particles receive. A current of water corresponding to a velocity below one millimeter per second will, of course, not carry any of the particles out at the top of the cylindrical tube, but will keep them moving through the conical portion of the tube. If now the current be increased until its velocity is greater than one millimeter per second after having run at the slower velocity for fifteen or twenty minutes, very little of the sediment will pass over, although theoretically the whole of it should. Even at a velocity of five millimeters per second, much of the sediment will remain in the tube. This, of course, is due to the coagulation of the particles into molecular aggregates having a higher hydraulic value even than five millimeters per second. These aggregates can be broken up by violent stirring or moderate boiling, and the sediment reduced again to its proper value. The conclusions which Hilgard derives from a study of the above phenomena are as follows: 1. The tendency to coagulation is, roughly, in an inverse ratio to the size of the particles. With quartz grains it practically ceases when their diameter exceeds about two-tenths of a millimeter having a hydraulic value of eight millimeters per second. The size of the aggregates formed follows practically the same law as above. Sediment of 0.25 millimeter hydraulic value will sometimes form large masses like snow-flakes on the sides of the elutriator tube. 2. The degree of agitation which will resolve the aggregates into single grains is inversely as the size of the particles; or, more properly perhaps, inversely as their hydraulic value. 3. The tendency to flocculation varies inversely as the temperature. So much so is this the case that Hilgard at one time contemplated the use of water at the boiling point in the mechanical analysis of soils, in place of mechanical stirring. 4. The presence of alcohol, ether, and of caustic or carbonated alkalies, diminishes the tendency to flocculation, while the presence of acids and neutral salts increases it. 5. As between sediments of equal hydraulic value, but different densities, the tendency to flocculation seems to be greater with the less dense particles. In regard to the mechanical actions which take place between the particles, Hilgard considers them as irregular spheroids, each of which can at best come in contact at three points with any other particle. The cause of aggregation cannot therefore be mere surface adhesion independent of the liquid, and the particles being submerged there is no meniscus to create an adhesive tension. Since experiment shows that the flocculative tendency is measurably increased by the cohesion coefficient of the liquid, it seems necessary to assume that capillary films of the latter interposed between the surfaces of solids create a considerable adhesive tension even in the absence of a meniscus. =182. Effect of Potential of Surface Particles.=—Whitney suggests that this is due to the potential of the surface particles of solids and liquids.[123] The potential of a single water particle is the work which would be required to pull it away from the surrounding water particles and remove it beyond their sphere of attraction. For simplicity, it may be described as the total force of attraction between a single particle and all other particles which surround it. With this definition, it will be seen that the potential of a particle on an exposed surface of water is only one-half of the potential in the interior of the mass, as half of the particles which formerly surrounded and attracted it were removed when the other exposed surface of water was separated from it. A particle on an exposed surface of water, being under a low potential, will therefore tend to move toward the center of the mass where the potential, _i. e._, the total attraction, is greater, and the surface will tend to contract so as to leave the fewest possible number of particles on the surface. This is surface tension. If, instead of air, there is a solid substance in contact with the water, the potential will be greater than on an exposed surface of the liquid, for the much greater number of solid particles will have a greater attraction for the water particles than the air particles had. They may have so great an attraction that the water particle on this surface, separating the solid and liquid, may be under greater potential than prevails in the interior of the liquid mass. Then the surface will tend to expand as much as possible, for the particles in the interior of the mass of liquid will try to get out on the surface. This is the reverse of surface tension. It is surface pressure, which may exist on a surface separating a solid and liquid. Muddy water may remain turbid for an indefinite time, but if a trace of lime or salt be added to the water the grains of clay flocculate, that is, they come together in loose, light flocks, like curdled milk, and settle quickly to the bottom, leaving the liquid above them clear. Ammonia and some other substances tend to prevent this and to keep the grains apart if flocculation has already taken place. If two small grains of clay, suspended in water, come close together they may be attracted to each other or not, according to the potential of the water particles on the surface of the clay. If the potential of the surface particle of water is less than that of the particle in the interior of the mass of liquid, there will be surface tension, and the two grains will come together and be held with some force, as their close contact will diminish the number of surface particles in the liquid. If, on the other hand, the potential of the particle on the surface of the liquid is greater than of the particle in the interior of the mass, the water surface around the grains will tend to enlarge, as there will be greater attraction for the water particles there than in the interior of the mass of liquid, and the grains of clay will not come close together and will even be held apart, as their close contact would diminish the number of surface particles in the liquid around them. =183. Influence of Surface Tension.=—Hilgard supposes that the surface tension which is assumed to exist between two liquid surfaces must exert a corresponding influence between the surfaces of solids and liquids, apart from any meniscal action. It is then to be expected that the adhesion of the particles constituting one of these floccules will be very materially increased whenever the formation of menisci between them becomes possible by the removal of the general liquid mass. Suppose one of the floccules to be stranded, it will, in the first place, remain immersed in a sensibly spherical drop of liquid. As this liquid evaporates, the spherical surface will become pitted with menisci forming between the single projecting particles, and as these menisci diminish their radius by still further evaporation, the force with which they hold the particles together will increase until it reaches a maximum. As the evaporation progresses beyond this point of maximum, the adhesion of the constituent particles must diminish by reason of the disappearance of the smaller menisci, and when finally the point is reached when liquid water ceases to exist between the surfaces, the slightest touch, or sometimes even the weight of the particles themselves, will cause a complete dissolution of the floccule, which then flattens down into a pile of single granules. In regard to natural deposits from water, Hilgard supposes that they are always precipitated in a flocculated state. The particles of less than two-tenths millimeter diameter are carried down with those of a larger diameter having much higher hydraulic value. Thus the deposition of a pure clay can take place under only very exceptionable circumstances. Whitney, on the other hand, suggests that grains of sand and clay carry down mechanically the particles of fine silt and clay as they settle in a turbid liquid in a beaker; and it is often difficult to wash out a trace of fine material from a large amount of coarse particles, for this reason, although there may be no trace whatever of flocculation. =184. Destruction of Floccules.=—The destruction of the natural floccules is seen in the ordinary process of puddling earth or clay. It is also the result of violent agitation of water or of kneading or boiling, or, finally, to a certain extent, of freezing. All these agencies are employed by the workers in clay for the purpose of increasing the plasticity which depends essentially upon the finest possible condition of the material to be worked. As an illustration of this, Hilgard cites the fact that any clay or soil which is worked into a plastic paste with water, and dried, will form a mass of almost stony hardness. If, however, to such a substance one-half per cent of caustic lime be added, a substance which possesses in an eminent degree the property of coagulating clay, the diminution of plasticity will be obvious at once, even when in a wet condition. If now the mass be dried, as in the previous case, it is easily pulverized. This is an illustration of the effect of lime upon stiff lands, rendering them more readily pulverulent and tillable. The conversion of the lime into a carbonate in the above experiment by passing bubbles of carbonic acid through the mass while still suspended in water does not restore the original plasticity, thus illustrating experimentally the fact known to all farmers that the effect of lime on stiff soil lasts for many years, although the whole of the lime in that time has been converted into carbonate. =185. Practical Applications.=—The practical application of this is, according to Hilgard, that the loosely flocculated aggregation of the soil particles is what constitutes good tilth. For this reason the perfect rest of a soil, if it is protected from the tamping influence of rains and the tramping of cattle, may produce a condition of tilth which cannot be secured by any mechanical cultivation. As an illustration of this, the pulverulent condition of virgin soils protected in a forest by the heavy coating of leaves may be cited. On the contrary, as pointed out by Hilgard, there are some kinds of soil in which a condition of rest may produce the same effect as tamping. These are soils which consist of siliceous silt without enough clay to maintain them in position after drying. In such a case, the masses of floccules collapse by their own weight or by the least shaking, and fall closely together, producing an impaction of the soil. This takes place in some river sediment soils in which the curious phenomenon is presented of injurious effects produced by plowing when too dry, which is the direct opposite of soils containing a sufficient amount of clay and which are injured by plowing too wet. It is further observed that the longer a soil has been maintained in good tilth, the less it is injured by wet plowing. This is doubtless, according to Hilgard, due to the gradual cementation of the floccules by the soil water which fixes them more or less permanently. Whitney believes that the arrangement of the grains, or the condition of flocculation in the soil, or the distance apart of the soil grains, is determined, to a large extent, by the potential on the surface of the grains; and he suggests that by changing this the exceedingly fine grains of silt and clay can be pulled together or can be pushed further apart, and so alter the whole texture of the land. The action of alkaline carbonates in preventing flocculation, and thus rendering tillage difficult or impossible, is pointed out by Hilgard in the case of certain alkali soils of California. The soils which are impregnated with alkaline carbonates are recognized by their extreme compactness. The suggestion of Hilgard to use gypsum on such soils has been followed by the happiest results. This gypsum renders any phosphates present insoluble, and thus prevents loss by drainage, and yet leaves the plant food in a sufficiently fine state as to be perfectly available for vegetation. =186. Suspension of Clay in Water.=—The suspension of clay in water and the methods of producing or retarding flocculation and precipitation have also been studied by Durham.[124] His experiment is made as follows: In a number of tall glass jars fine clay is stirred with water, and the results of precipitation watched. In all cases it will be noticed that the clay rapidly separates into two portions, the greater part quickly settling down to the bottom of the jars, and the smaller part remaining suspended for a greater or less length of time. The power which water possesses of sustaining clay is gradually destroyed by the addition of an acid or salt; a very small quantity, for instance, of sulfuric acid, is sufficient to precipitate the clay with great rapidity. In solutions of sulfuric acid and sodium chlorid of varying strengths, suspended clay is precipitated in the order of the specific gravity of the solutions, the densest solutions being the last to clear up. This may be due to the greater viscosity of the denser liquids. The power which water possesses of sustaining clay is gradually decreased by the addition of small quantities of certain salts and of lime. =187. Effect of Chemical Action=—Brewer[125] emphasizes the importance of chemical action in the flocculation of clays. As expressed by him the chemical aspects of the phenomena of sedimentation have either been lightly considered or entirely ignored. Brewer is led to believe that the action of clay thus suspended is analogous to that of a colloidal body. Like a colloid, when diffused in water, the bulk of the mass is very great, shrinking enormously on drying. He therefore concludes that clays probably exist in suspension as a series of hydrous silicates feebly holding different proportions of water in combination and having different properties so far as their behavior to water is concerned. Some of them he supposes swell up in water much as boiled starch does, and are diffusible in it with different degrees of facility, and that the strata observed on long standing of jars of suspended clay represent different members of this series of chemical compounds which hold their different proportions of combined water very feebly and are stable under a very limited range of conditions. These compounds are probably destroyed or changed in the presence of acids, salts and various other substances, and are stable only under certain conditions of temperature, those which exist at one temperature being destroyed or changed to other compounds at a different temperature. =188. Theory of Barus.=—Brewer’s hypothesis, however, is not in harmony with the demonstration of Barus, who proves that a given particle of clay has the same density in ether as in water. The physical and mathematical aspects of sedimentation have also been carefully studied by Barus.[126] The mathematical conditions of a fine particle suspended in a liquid and free from the influences of flocculation are described by Barus in the following equations. If P be the resistance encountered by a solid spherule of radius r, moving through a viscous liquid at the rate x, and if k be the frictional coefficient, then P = 6πkrx. Again, the effective part of the weight of the particle is P´ = ⁴⁄₃πr³ (ρ-ρ´)g, where g is the acceleration of gravity and ρ and ρ´ the density of solid particle and liquid, respectively. In case of uniform motion P = P´. Hence x = 2/9kr² (ρ-ρ´)g ... (1). In any given case of thoroughly triturated material the particles vary in size from a very small to a relatively large value; but by far the greater number approach a certain mean figure and dimension. An example of this condition of things may be formulated. To avoid mathematical entanglement let y = Ax^{³⁄₂}e^{-x²} ... (2) where y is the probable occurrence of the rate of subsidence x. If now the turbidity of the liquid (avoiding optical considerations) be defined as proportional to the mass of solid material particles suspended in unit of volume of liquid, then the degree of turbidity which the given ydx particles add to the liquid is, _caeteris paribus_, proportional to r³ydx, where r is the mean radius. Hence the turbidity, T, at the outset of the experiment (immediately after shaking), is T = T₀∫₀^∞r³ydx = T₀, where equations (1) and (2) have been incorporated. If the plane at a depth d below the surface of the liquid be regarded, then at a time after shaking the residual turbidity is (3) ... T_{d} = T₀∫^{d/t}₀r³ydx = T₀(1 − (1 + (d²/t² × e^{-d²/t²})) The equation describes the observed occurrences fairly well. The phenomena of stratification observed by Brewer are explained by Barus from the above formula: In proportion as the time of subsidence is greater, the tube shows opacity at the bottom, shading off gradually upward, through translucency, into clearness at the top. If, instead of equation (2), there be introduced the condition of a more abrupt maximum, if, in other words, the particles be very nearly of the same size, then subsidence must take place in unbroken column capped by a plane surface which at the time zero coincided with the free surface of the liquid. Again, suppose one-half of the particles of this column differ in some way uniformly from the other half. Then at the outset there are two continuous columns coinciding, or, as it were, interpenetrating throughout their extent. But the rate of subsidence of these two columns is necessarily different, since the particles, each for each, differ in density, radius and frictional qualities, by given fixed amounts. Hence the two surfaces of demarcation at the time zero coincided with the free surface. In general, if there be n groups of particles uniformly distributed, then at the time zero n continuous columns interpenetrate and coincide throughout their extent. At the time t, the free surface will be represented by n consecutive surfaces of demarcation below it, each of which caps a column, the particles of which form a distinct group. From a further discussion of the mathematical condition under which the subsidence of the particles takes place, Barus is of the opinion that Durham’s theory of suspension being only a lower limit of solution is rapidly gaining ground, yet without being attended with concise experimental evidence which will account for the differences in the rate of subsidence. On the contrary, Brewer’s hypothesis of colloidal hydrates is more easily subjected to experimental proof. The test shows that the particles retain their normal density, no matter how they are suspended or circumstanced. Further, in the explanation of the phenomenon of sedimentation, the following principle may be regarded as determined; namely, if particles of a comminuted solid are shaken up in a liquid, the distribution of parts after shaking will tend to take place in such a way that the potential energy of the system of solid particles and liquid, at every stage of subsidence, is the minimum compatible with the given conditions. According to Barus it is necessary, in order to pass judgment on the validity of any of the given hypotheses, to have in hand better statistics of the size of the particles relatively to the water molecule, than are now available. Inasmuch as the particles in pure water are individualized and granular, it is apparently at once permissible to infer the size of the particles from the observed rates of subsidence. His observations show that the said rate decreases in marked degree with the turbidity of the mixture. Hence the known formulæ for single particles are not rigorously applicable, though it cannot be asserted whether the cause of discrepancy is physical or mathematical in kind. It follows that special deductions must be made for the subsidence of stated groups of particles before an estimate of their mean size can fairly be obtained. Rowland[127] reaches a closer approximation for the fall of a single particle by showing that the liquid, even at a large distance from the particle, is not at rest. In the case of water, however, it is noticed that despite the large surface energy of the liquid, subsidence takes place in such a way that for a given mass of suspended sediment the surfaces of separation are a maximum. On the other hand, in case of subsidence in ether or in salt solutions, the solid particles behave much like the capillary spherules of a heavy liquid shaken up in a lighter liquid with which it does not mix. In other words, the tendency here is to reduce surfaces of separation to the least possible value, large particles growing in mass and bulk mechanically at the expense of smaller particles; in other words, exhibiting the phenomenon of flocculation. =189. Physical Explanation of Subsidence.=—Whitney[128] thinks that the phenomena of the suspension of clay in water may be explained on purely physical principles, and that neither the partial solution nor hydration hypotheses are necessary, or will explain the suspension of clay in water, for the solution, or hydrated substance, would still have a higher specific gravity than the surrounding liquid. He calls attention in the first place to the fact, that in a turbid liquid, which has been standing for weeks and which is only faintly opalescent, the grains in suspension are still of measurable size, if properly stained as in bacteriological examinations and viewed through an oil emersion objective. He gives a value of 0.0001 millimeter, as the lower limit of the diameters of these particles of “clay,” which are usually met with in agricultural soils. He refers to the fact that fine dust and ashes, and even filings of metals, may remain in suspension in the air for days and even months in very apparent clouds, or haze, although they may be a thousand times heavier than the surrounding air. Particles of clay, no smaller than the limits which have been assigned, should remain in suspension in the much heavier fluid, water, for an indefinite time, for the volume or weight of the particles (⁴⁄₃)(πr³) decreases so much more rapidly in proportion than the surface (4πr²), that there is, relatively, a larger amount of surface area in these fine clay particles, and a great deal of surface friction in their movement through a medium, and they would settle very slowly. Under ordinary conditions, however, the mean daily range of temperature is about twenty degrees, the mean monthly range is fifty degrees, and the yearly range 100° F., and the ordinary convection currents, induced by the normal change of temperature, would be sufficient of itself to keep these fine particles in suspension in the liquid for an indefinite time, as it is known that currents of air keep fine particles of dust and ashes in suspension. If the volume or weight of a fine gravel, having a diameter of one and five-tenth millimeters, be taken as unity, then for a particle, having a diameter of 0.00255 millimeter, which is the mean diameter for Whitney’s clay group, the volume decreases in the ratio 1:0.000000004853, and the surface decreases only in the ratio 1:0.000286. =190. Practical Applications.=—The action of mineral substances in promoting flocculence has been taken advantage of in later times in the construction of filters for purifying waters holding silt in solution. In these filters the introduction of a small quantity of alum, or some similar substance, into the water usually precedes the mechanical separation of the flocculent material. In the same way the action of iron and other salts on sewage waters has been made use of in their purification and in the collection of the sewage material for fertilizing purposes. =191. Separation of the Soil Into Particles of Standard Size.=—The agronomic value of a soil depends largely on the relative size of the particles composing it. The finer the particles, within a certain limit, the better the soil. The size of the particles may be estimated in three ways: (1) by passing through sieves of different degrees of fineness; (2) by allowing them to subside for a given time in water at rest; (3) by separating them in water moving at a given rate of speed. The first method is a crude one and is used to prepare in a rough way, the material for the second and third processes. =192. Separation in a Sieve.=—The soil should be dry enough to avoid sticking to the fingers or to prevent agglutination into masses when subjected to pressure. It should not, however, be too dry to prevent the easy separation of any agglutinated particles under the pressure of the thumb or of a rubber pestle. The sieve should have circular holes punched in a sheet of metal of convenient thickness to give it the requisite degree of strength. Sieves made of wire gauze are not so desirable but it is difficult to get the finer meshes as circular perforations. Such sieves cannot give a uniform product on account of the greater diagonal diameter of the meshes and the ease with which the separating wires can be displaced. It is convenient to have the sieves arranged _en batterie_; say in sets of three. Such a set should have the holes in the three sieves of the following dimensions; _viz._, 1st sieve 2 millimeters diameter. 2nd „ 1 millimeter „ 3rd „ 0.5 „ „ Coarser single sieves may be used to separate the fragments above two millimeters diameter if such a further classification be desired. Each sieve fits into the next finer one and the separation of a sample into three classes of particles may be effected by a single operation. In most cases, however, it is better to conduct each operation separately in order to promote the passage of agglutinated particles by gentle pressure with the thumb or with a rubber pestle. In no case should a hard pestle be used and the pressure should never be violent enough to disintegrate mineral particles. There is much difference of opinion concerning the smallest size of particles which should be obtained by the sieve. Most analytical processes prescribe particles passing a sieve of one millimeter mesh (¹⁄₂₅ inch). There is little doubt, however, of the fact that a finer particle would be better fitted for subsequent analysis by the hydraulic method. For this purpose a sieve of 0.5 millimeter circular mesh is preferred. =193. Sifting with Water.=—In soils where the particles adhere firmly the sifting should be done with the help of water. In such cases the soil is gently rubbed with a soft steple or the finger in water. It is then transferred to the sieve or battery of sieves which are held in the water, and rubbed through each of the sieves successively until the separation is complete. After the filtrate has stood for a few minutes the supernatant muddy liquor is poured off, the part remaining on the sieve is added to it and the process repeated until only clean particles larger than 0.5 millimeter are left on the sieve. These particles can be dried and weighed and entered on the note book as sand. The filtrate should be evaporated to dryness at a gentle temperature and when sufficiently dry be rubbed up into a homogeneous mass by a rubber pestle. The sieve recommended by the Association of Official Agricultural Chemists[129] for the preparation of fine earth for chemical analysis has circular openings ¹⁄₂₅ inch (one millimeter) in diameter. Wahnschaffe[130] directs that a sieve of two millimeters mesh be used in preparing the sample for silt analysis and that the residue after the silt analysis is finished, which has not been carried over by a velocity of twenty-five millimeters per second, be separated in sieves of one millimeter and 0.5 millimeter meshes respectively. Hilgard objects to leaving this coarse material in the sample during the process of churn elutriation on account of the attrition which it exerts and therefore directs that it be separated by sieve analysis before the elutriation begins. =194. Method of the German Experiment Stations.=[131]—In the method recommended for the German Agricultural Stations an attempt is made to secure even a finer sieve separation than that already mentioned. Sieves having the following dimensions are employed; sieve No. 1, square meshes 0.09 millimeter in size, diagonal measure 0.11 millimeter; sieve No. 2, square meshes 0.14 to 0.17 millimeter in diameter, diagonal measure 0.22 to 0.24 millimeter; sieve No. 3, square meshes 0.35 to 0.39 millimeter in diameter, diagonal measure 0.45 to 0.50 millimeter; finally a series of sieves one, two and three millimeters circular perforations. Five hundred grams of the soil (in the Halle Station only 250) are placed in a porcelain dish with about one liter of water and allowed to stand for some time with frequent stirring, on a water bath. After about two hours, when the soil is sufficiently softened so that with the help of a pestle it can be washed through the sieves, the process of sifting is undertaken in the following manner: Sieve No. 3 is placed over a dish containing water, the moistened soil placed therein and the sieve depressed a few centimeters under the water and the soil stirred by means of a pestle until particles no longer pass through. After the operation is ended the residue in the sieve is washed with pure water and dried. The part passing the sieve is thoroughly stirred and then washed with water into sieve No. 2 and treated as before. The product obtained in this way is brought into sieve No. 1 and carefully washed. All the products remaining on each of the sieves are dried at 100° and weighed. The portion passing sieve No. 1 is either dried with its wash water or estimated by loss by deducting from the total weight taken, the sum of the other weights obtained. If a more perfect separation of the first sieve residue be desired it can be obtained by passing it through sieves of the last series which may have meshes varying in size, _viz._: one, two, or three millimeters in diameter. Each sieve of the same class should have holes uniformly of the same size. The sieve products are characterized as follows: The part passing a three millimeter sieve is called fine earth, while the part remaining is called gravel. The fine earth is separated into the following products: The part that passes through the three millimeters opening and is left by the two millimeters opening is called _steinkies_. The product from the two millimeters opening and the residue from the one millimeter opening is called _grobkies_. The product from the one millimeter opening and the residue on the sieve No. 3 is called _feinkies_. The product from the sieve No. 3 and the residue from the sieve No. 2 is called coarse sand. The product from sieve No. 2 and the residue from sieve No. 1 is called fine sand. The product from sieve No. 1 is called dust. The dust can be further separated into sand, dust, and clay. For the examination of the clay the Kühn silt cylinder as modified by Wagner, is recommended. The cylinder has a diameter of eight centimeters and a height of thirty centimeters, and is furnished with a movable exit tube reaching to its bottom. =195. General Classification of the Soil by Sieve Analysis.=—The classification recommended by the German chemists is satisfactory but the following one is more simple. All pebbles, pieces of rock, etc., should first be separated by a two millimeters circular mesh sieve, dried at 105° and weighed. The result should be entered as pebbles and coarse sand. The finer sand may be separated with a sieve of one millimeter circular openings. The still finer sand is next separated with the sieve of 0.5 millimeter circular openings as indicated above. The sample may now be classified as follows: 1. Coarse pebbles, sticks, roots, etc., separated by hand. 2. Pebbles and coarse sand not passing a two millimeters sieve. 3. Sand not passing a one millimeter sieve. 4. Fine sand not passing a 0.5 millimeter sieve. 5. Fine earth passing a 0.5 millimeter sieve. =196. Classification of Orth.=[132]—As fine silt are reckoned those particles which range from 0.02 to 0.05 millimeter; as fine sand the groups from 0.05 to 0.2 millimeter; as medium sized sand those ranging from 0.2 to 0.5 millimeter and for large grained sand those particles ranging from 0.5 to 2 millimeters in diameter. Particles over two millimeters form the last classification. SEPARATION OF THE EARTH PARTICLES BY A LIQUID. =197. Methods of Silt Analysis.=—The further classification of the particles of a soil passing a fine sieve can best be effected by separation in water. The velocity with which the current moves or with which the particles subside will cause a separation of the particles into varying sizes. The slower the velocity the smaller the particles which are separated. There is, however, a large and important constituent of a soil which remains suspended in water, or in a state of seeming solution. This suspended matter would still be carried over by a current of water moving at a rate so slow as to make a subclassification of it impossible. This suspended matter passing off at a given velocity may be classed as clay, and it consists in fact chiefly of the hydrated silicate of alumina, or other particles of equal fineness. The laws which govern its deposit have already been discussed. The apparatus which have been used for silt analysis may be grouped into four classes. (1) Apparatus depending on the rate of descent of the particles of a soil through water at rest. The apparatus for decanting from a cylinder or a beaker belong to this class. (2) Apparatus which determine the rate of flow by passing the liquid through a vessel of conical shape. The system of Nöbel is a good illustration of this kind of apparatus. (3) Apparatus in which the elutriating vessel is cylindrical and the rate of flow determined by a stop-cock or pressure feed apparatus. The system of Schöne represents this type. (4) Apparatus in which the above system is combined with a device for mechanically separating the particles and bringing them in a free state into the elutriating current. The system of Hilgard is the type of this kind of apparatus. In practice the use of cylindrical apparatus with or without mechanical stirring and the method by decantation have proved to be the most reliable and satisfactory procedures. Between the beaker and churn methods, of separation there is little choice in regard to accuracy. Which is the superior method, is a question on which the opinions of experienced analysts are divided. The various processes will be described in the order already mentioned. =198. Methods Depending on Subsidence of Soil Particles.=—The simplest method of effecting the further separation of the soil particles is without doubt that process which permits them to fall freely in a liquid sensibly at rest. The practical difficulties of this method consist in the trouble of securing a perfect separation of the particles, in preventing flocculation after division and in avoiding currents in the liquid of separation. For the separation of the soil particles for this method boiling and wet pestling are the only means employed. The flocculation of the separated particles may be partially prevented by adding a little ammonia to the water employed. The author has also tried dilute alcohol as the separating liquid but the results of this method are not yet sufficiently definite to find a place in this manual. Evidently the practical impossibility of avoiding convection currents prevents the use of water at a high temperature for this separation, although the tendency to flocculation almost disappears as the temperature approaches 100°. The general method of avoiding the errors due to flocculation in the subsidence method consists in repestling the deposited particles and thus subjecting them as often as may be necessary to resedimentation. These principles are well set forth by Osborne,[133] who states that when a soil is completely suspended in water by vigorous agitation, particles of all the sizes present are to be found throughout the entire mass of liquid. When subsidence takes place, the larger particles will go down more rapidly than the smaller ones, but some of the small particles that are near the bottom will be deposited sooner than some of the larger ones which have a much greater distance to travel. Thus, independently of the fact that the larger particles in their descent are somewhat impeded by the smaller, the smaller being at the same time somewhat hastened by the larger, the sediment that reaches the bottom at any moment is a more or less complex mixture of all the mechanical elements of the soil. The liquid, however, above this sediment at the same moment will have completely deposited all particles exceeding certain dimensions of hydraulic value, determined mainly by the time of subsidence. If now the aforesaid first sediment be suspended in pure water, and allowed to subside for the same time as before, the larger part of it will be again deposited, but some will remain in suspension, consisting of a considerable part of the finer matter of the first sediment. By pouring off these suspended particles with the water and agitating the sediment again with clear water as before, another portion of fine particles will be suspended and may be decanted from it. On continuing this process of repeated decantations it will soon be found that the soil has been separated into two grades. It is evident that in this way a separation can be made, but it is perhaps not so clear that such a separation would be sharp enough for the purposes of a mechanical soil analysis. If, for instance, the separation is to be made at 0.05 millimeter diameter, it is evident that by repeated decantations all below 0.01 millimeter can be washed out of that above 0.05 millimeter, but it may not appear so probable that all below 0.045 millimeter can be removed without removing some above 0.055 millimeter. Such a result may be easily attained, however, if the following principle be adhered to: Make the duration of the subsidence such that the liquid decanted the first few times shall contain nothing larger than the desired diameter. Then decant into another vessel, timing the subsidence so that the sediment shall contain nothing smaller than the chosen diameter. This can not be done without decanting much that is larger than the chosen diameter, but the greater part of the particles greater and less than the chosen diameter can be removed and an intermediate product obtained, the diameters of whose particles are not very far from that desired. If this intermediate portion be again subjected to the same process, two fractions may be separated from it, one containing particles larger than the chosen diameter and another containing particles smaller than this diameter, while a new intermediate product will remain which is less in amount than that resulting from the first operation. By frequent repetitions of this process this intermediate product can be reduced to a very small amount of substance the particles of which have diameters lying close to the chosen limit and may then be divided between the two fractions. The principles of the separation described by Osborne set forth with sufficient clearness the purposes to be achieved by the analysis. The chief methods of manipulation practiced will be found below. =199. Kühn’s Silt Cylinder.=—A simple form of apparatus for the determination of silt by the sedimentation process is the one described by Kühn.[134] The cylinder should be about twenty-eight centimeters high with a diameter of 8.5 centimeters. At the lower end of the cylinder five centimeters from the bottom it carries a tube 1.5 centimeter in diameter furnished with a pinch-cock and held in position by a rubber stopper. In carrying out the process thirty grams of sifted soil (two millimeters mesh sieve) are boiled with water for an hour and after cooling the soil and water are washed into the separating cylinder. The cylinder is then filled with water with constant shaking. After standing for ten minutes the stop-cock is opened and the water with its suspended matter allowed to flow into a porcelain dish. The cylinder is then again filled with water and the process is continued until the water drawn off is practically clear. The fine particles having been separated in this way the next coarser grade of particles is separated by repeating the process at intervals of five minutes. By these two operations it is considered that the clay is entirely removed. The residue remaining in the cylinder is dried and weighed. The relative proportions of clay and residue in the sample are thus determined. The residue is then separated into two portions by sieves of one millimeter and 0.5 millimeter mesh. The soil is thus separated into the following parts: 1. By the first sifting coarse quartz larger than two millimeters diameter. 2. Fine quartz two millimeters, to one millimeter diameter. 3. Coarse sand one millimeter, to 0.5 millimeter diameter. 4. Fine sand finer than 0.5 millimeter diameter. 5. Silt, clay, humus, etc., separated by the water. =200. Knop’s Silt Cylinder.=—The cylinder recommended by Knop[135] is essentially that of Kühn being furnished with four lateral tubes instead of one (Fig. 25). FIGURE 25. KNOP’S SILT CYLINDER. ] The sample of soil, twenty-five to thirty grams, after passing a two millimeters mesh sieve, and long boiling, is washed through a series of sieves of the following diameters of mesh respectively; _viz._, one millimeter, 0.5 millimeter, 0.25 millimeter, and 0.1 millimeter. The part which passes the finest sieve is placed in a Knop’s cylinder, the cylinder filled with water one decimeter above upper tube and well shaken. The cylinder is allowed to rest for five minutes when the upper cock is opened and the water drawn off. After five minutes more the next tube is opened and so on with equal intervals for the three upper tubes. The operation is repeated with fresh water until the water drawn off is clear. Finally the lowest tube is opened and all the water poured off of the sandy residue. The space between each tube is one decimeter. The dust remaining is dried and weighed and the weight of material carried over as silt determined by difference. =201. Siphon Silt Cylinder.=—Instead of the tubulated cylinder one furnished with a siphon can be employed[136] (Fig. 26). It should be about forty centimeters high and six centimeters internal diameter. The cylinder first receives twenty-five to thirty grams of the well boiled fine earth and then water until there is but a small space between it and the stopper when the latter is inserted. The cylinder is marked exactly 200 millimeters below the surface of the water with a narrow strip of paper at _a_, stoppered, inverted and well shaken. The cylinder being again placed in normal position the soil particles under the influence of gravity tend to sink with greater or less rapidity according to their size. The siphon _a b c_ is filled with water, the cock at _c_ closed and the opened end _a_ placed in the cylinder A just at the mark 200 millimeters below the surface of the water, and the water thus transferred to B when desired. If the suspended matter is allowed to stand for 100 seconds the particles of more than two millimeters hydraulic value will have fallen below the open end of the siphon. If allowed to stand 1,000 seconds the silt value of the particles will be 0.2 millimeter per second. Whatever the number of seconds may be, the operation is continued until the water removed is practically clear. The open end of the siphon _a_ should be bent upwards so that no disturbing current may bring the particles below the line into the liquid discharged into B. FIGURE 26. SIPHON CYLINDER FOR SILT ANALYSIS. ] While the results obtained by this method are satisfactory as compared with other similar processes it cannot be highly recommended because of the time and trouble required to get a complete separation and by reason of the difficulty of collecting the separated silt. =202. Wolff’s Method.=[137]—As modified by Wolff the Knop process is conducted as follows: Fifty grams of fine earth are boiled with water and then the entire mixture is passed through three sieves with openings of one millimeter, 0.5 millimeter, and 0.25 millimeter in diameter, respectively. The finest part is mixed with water to a height of eighteen centimeters in a bottle twenty centimeters high and having a capacity of one liter and thoroughly agitated, after which it is left to rest, and finally the turbid liquid is drawn off with a siphon, the bottle refilled with water, agitated, and left to rest, and the process repeated as long as the water carries any suspended matter after a definite time. Wolff proposes for the first three periods of rest one hour, for the second three, a half an hour, for the third three, a quarter of an hour, and for the fourth three, five minutes. =203. Moore’s Modification of Knop’s Method.=[138]—The sample of soil is first passed through a sieve having round perforations three millimeters in diameter. The weight of the particles remaining on the sieve is then determined, and likewise that of the portion passing through, which is known as fine earth. The last named portion constitutes the material for all subsequent operations of mechanical and chemical analysis. Thirty grams of the fine earth are boiled rapidly with water until the lumps are disintegrated and clayey portions separated from the sand. The material is then successively washed through perforated metal sieves, the holes of which are respectively 1, 0.5, and 0.25 millimeter in diameter. The portions retained on the sieves are severally dried, ignited and weighed, and the finest portion, or that passing through the 0.25 millimeter sieve, is then submitted to the following process of separation: The sediment and water passing through the 0.25 millimeter sieve are placed in a glass cylinder fifty centimeters long and thirty-seven millimeters in internal diameter. The cylinder is closed at the bottom and is provided with a lateral tube inserted six centimeters above the bottom. Three other lateral tubes are inserted at intervals of ten centimeters above the first tube, and a ring is etched into the cylinder ten centimeters above the uppermost tube. The lateral tubes are closed with rubber tubes compressed by spring clips. The sediment being placed in the cylinder, water is added to the mark or ring, the cylinder closed with a rubber stopper, and vigorously shaken until the contents are thoroughly mixed. It is then placed upright, the stopper removed, and after standing undisturbed for five minutes the clip on the uppermost tube is opened and the water allowed to flow into a beaker. After five minutes further standing, the second clip is opened and the water drawn off into the same beaker; in the same manner the water is drawn off from the other tubes at intervals of five minutes until the level of the lowest tube is reached. The cylinder is then refilled with water to the mark, thoroughly shaken after inserting the stopper and the water again drawn off at intervals of five minutes, as before; the operation being repeated until the water drawn off is almost free from turbidity. The sediment remaining in the cylinder from this process of washing by subsidence is termed by Knop, fine sand, the material flowing off in suspension in the wash waters, dust, and the process of separation by Knop’s original method ends here. In order to remedy the imperfect separation into definite particles secured by the above method, Moore proposes the following device: The fine sand from the first series of subsidences is placed in a separate vessel, the washings are allowed to remain undisturbed for twelve hours, the turbid liquid decanted and the sediment returned to the cylinder. Water is then added to the mark, the whole shaken, and the liquid drawn off at intervals of five minutes, as in the first series. The sediment from this operation is placed in a separate beaker, the washings returned to the cylinder, and again allowed to subside as before; the sediment from this second subsidence is added to that from the preceding operation, and the washings again returned to the cylinder, the operation being repeated as long as any sediment can be obtained from renewed treatment of the washings; the final washings are then placed in a separate vessel for subsequent microscopic measurements. The collective sediments from the last series of operations are then returned to the cylinder and allowed to subside with fresh additions of water, as in the case of the first series; the fine sand thus obtained being added to that from the first series, and the washings being collected in a large beaker. The latter are left at rest for twelve hours, and the sediment returned to the cylinder and treated as before until no further separation can be effected. The fine sand resulting from all of these operations is then dried, ignited and weighed; the weight of the portion removed by the washing being determined by difference, as it is, owing to its excessively slow rate of subsidence, found impracticable to collect it for direct weighing. The size of the particles of fine sand is then determined by micrometric measurement. Similar measurements are made on the material obtained by long subsidence from the washings from the foregoing operations. The average diameter of the largest particles should not exceed 0.01 millimeter. =204. Statement of Results.=—The results of the analyses on three soils from the localities indicated in the table, and the method of stating them, are given in the following table: New Milford, Clarksville, Granville, Conn., per Tenn., per N. C., per cent. cent. cent. Particles larger in diameter 8.55 0.32 0.23 than 3.0 millimeters Particles of diameter from 3.0 4.96 0.45 15.04 millimeters to 1.0 millimeter Particles of diameter from 1.0 4.43 0.96 33.43 millimeter to 0.5 millimeter Particles of diameter from 0.5 11.86 1.25 18.82 millimeter to 0.25 millimeter Particles of diameter from 0.25 60.54 61.58 23.59 millimeter to 0.01 millimeter Particles smaller in diameter 9.66 35.44 8.89 than 0.01 millimeter ─────────────────────────────────────────────────────────────────────── Total 100.00 100.00 100.00 =205. Method of Bennigsen.=—The silt flasks recommended by Bennigsen[139] are shown in Fig. 27. The glass flask _b_ carries a long cylindrical neck _a_ the upper part of which is graduated in cubic centimeters. Ten grams of the fine soil are shaken with water in the flask, the neck of which is closed with a rubber stopper. The flask is then inverted bringing the soil and water into the neck. The flask is hung up and sedimentation is assisted by imparting a pendulous motion to the neck for ten minutes. After an hour the soil particles have separated into a coarse layer below and a fine layer above. The relative volumes of the two layers are then read off in cubic centimeters. While this method may be useful in helping to form a speedy judgment concerning the character of a soil it can lay no claim to being an accurate method of silt separation. FIGURE 27. BENNIGSEN’S SILT FLASKS. ] =206. Method of Gasparin.=—The method of Gasparin only gives a very primitive separation of the various components of the earth according to their fineness. It is conducted as follows: Ten grams of sifted earth are put into a beaker, water is added and strongly agitated; after five minutes the water is decanted into another vessel, the first vessel is filled anew with water, agitated, decanted, and this process is repeated until the liquid remains perfectly clear. Only two portions are weighed, _i. e._, the pebbles which remain in the sieve and the coarse sand which remains in the beaker; while the argillaceous portion drawn off with the water is determined by the difference. =207. The Italian Method.=—The following modification of Gasparin’s process is practiced by the Italian chemists:[140] Twenty grams of earth are passed through a sieve having openings of one millimeter in diameter, then the sifted part is mixed with 100 cubic centimeters of water in a 200 cubic centimeters beaker and left to rest for some hours, then strongly agitated and after ten seconds the turbid liquid is poured into another vessel of half a liter capacity. This manipulation is repeated until the liquid is clear. The decanted liquid is thoroughly agitated, then left to stand until the movement shall be completely arrested, after which the supernatant liquid is poured into another vessel holding two liters. To the residuum is added more water; it is agitated, decanted, and this process is repeated until the water is no longer turbid. =208. Method of Osborne.=—In the foregoing paragraphs the methods of silt separation by subsidence as practiced in different countries have been outlined. The good points of the various methods are combined in the process as carried out by Osborne.[141] The details of this method will be given with sufficient minuteness to make its practice possible by all analysts. _Selecting the Sample._—Several pounds of air-dried, fine earth are secured by passing the soil through a sieve, the holes of which are three millimeters in diameter. _Sifting._—Thirty grams of the above fine earth are stirred with 300 to 400 cubic centimeters of water and then thrown successively upon sieves with circular holes of 1, 0.5, and 0.25 millimeter diameter respectively. By means of successive additions of water and the use of a camel’s hair brush, all the fine material is made to pass through the sieves and these at the last are agitated under water in a shallow dish in such a way that the soil is immersed. The finest sieve should be well wet with water on its lower surface just before using. The finest particles which render the water turbid are easily washed through. The turbid water is kept separated from the clear water which comes off with the last portions that pass the sieves. The turbid water usually does not amount to more than one liter. _Elutriation._—The elutriation should be carried on so as to secure three grades of silt; the diameters of the particles ranging in the first grades from 0.25 to 0.05 millimeter, in the second grade from 0.05 to 0.01 millimeter, and in the third grade from 0.01 millimeter to the impalpable powder. The term sand is applied to the first grade, silt to the second, and dust to the third. After the turbid liquid from the sifting has stood a short time it is decanted from the sediment and after standing until a slight deposit is formed, is again decanted and the sediment examined with a microscope. If sand be present, the subsidence of the turbid liquid is continued until no more sand is deposited. As the sand subsides rapidly there is no difficulty in altogether freeing the liquid first decanted from this grade of particles. The sediment thus obtained contains all the sand, a part of the dust and much silt. As only dust and the finest silt render the water turbid the sediment is stirred a few times with a fresh quantity of water and decanted after standing long enough to let all the sand settle. When the water decanted is free from turbidity, the last portions of the soil passing through the sieve with clear water are added to the sediment and the decantations continued so as to remove most of the silt. When no more silt can be easily removed from the sediment without decanting sand, the decantations are made into a different vessel and the subsidences so timed as to remove as much of the silt as possible. By using a little care, at least three-quarters of the sand are thus obtained free from silt. The rest of the sand is mixed with the greater part of the silt which has been decanted into the second vessel. The size of the smallest particles in this vessel is determined with the microscope, to make sure that its contents are free from dust as they usually will be if, after settling for a few moments, they leave the water free from turbidity. The soil is thus separated into three portions, one containing sand, one sand and silt, and the other silt, dust, and clay. The sand and silt are separated from each other by repeating the subsidences and decantations in the manner just described. In this way there is removed from the sediment, on the one hand, a portion of silt free from sand and dust, and on the other hand a portion of sand free from silt. Thus is obtained a second intermediate portion consisting of sand and silt, but less in amount than the first and containing particles of diameters much more nearly approaching 0.05 millimeter. By repeating this process a few times, this intermediate portion will be reduced to particles whose diameters are very near 0.05 millimeter and which may be divided between sand and silt, according to judgment. The amount of this is usually very small. As soon as portions are separated, which the microscope shows to be pure sand or pure silt, they are added to the chief portions of these grades already obtained. The same process is applied to the separation of silt from dust. When all the silt has been removed from the dust and clay, the turbid water containing the dust and clay is set aside and allowed to settle in a cylindrical vessel for twenty-four hours. The vessel is filled to a height of 200 millimeters. According to Hilgard, the separation of the dust from clay during a subsidence of twenty-four hours, will give results of sufficient accuracy, although the clay then remaining suspended will not be entirely free from measurable fine particles up to 0.001 or 0.002 millimeter diameter. Small beakers and small quantities of distilled water are used at first for the decantations, as thus the duration of subsidence is less and more decantations can be made in a given time than when larger quantities of water are employed. Beakers of about 100 cubic centimeters capacity are convenient for the coarser grades, but it is necessary to use larger vessels for the fine sediments from which turbid water accumulates that cannot be thrown away, as may be done with the clear water, from which the coarse sediments settle out completely in a short time. It is best to keep the amount of water as small as possible in working out the dust since loss is incurred in using too large quantities. It is also necessary in most cases to subject the various fractions obtained during elutriation, to careful kneading with a soft rubber pestle so that the fine lumps of clay may be broken up and caused to remain suspended in the water. This treatment with the pestle should be done in such a way as to avoid as far as possible all grinding of the particles, the object being merely to pulverize the minute aggregations of clay and extremely fine particles which always form on drying a sample of soil after removing it from the ground. _Measurement of the Particles._—To determine the size of particles in suspension, a small glass tube is applied to the surface of the liquid in such a way as to take up a single drop which is transferred to a glass slide. This drop will contain the smallest particles in the liquid. To obtain a sample of the coarsest particles the liquid is allowed to stand long enough to form a very slight sediment and a portion of this sediment is collected with a glass tube. To determine the diameter of the particles in a sediment it is stirred vigorously with a little water and the pipette at once applied to the surface of the water. On decanting the greater part of the sediment, the large particles remain at the bottom of the beaker and may be easily examined. _Time._—The time required to make the separations, above described, is about two hours for each, so that an analysis including the sittings, is made in five or six hours, exclusive of the time necessary for collecting the dust and separating the clay, for which a subsidence of twenty-four hours is allowed. _Weighing the Sediments._—The sediments are prepared for weighing by allowing them to subside completely, decanting the clear water as far as possible, rinsing them into a weighed platinum dish and igniting. The dish is cooled in a desiccator. _Effect of Boiling._—The analyses show a very decided increase in the particles smaller than 0.01 millimeter diameter at the expense of coarser particles as the result of boiling. The surfaces of the coarser particles are seen to be polished and of a lighter color than those not boiled. The surfaces of the unboiled particles are coated with a film of fine material probably cemented to them by clay. When these coarse particles which have not been boiled, are violently stirred with water for a short time, no fine particles are detached from them; and a careful examination under the microscope fails to reveal in any of the sediments more than an occasional grain exceeding the 0.05 millimeter limit by so much as 0.01 millimeter, or the 0.01 limit by as much as 0.005 millimeter. It would, therefore, appear that these small particles thus set free by long boiling are really a part of the larger ones and should be treated as such in a mechanical analysis of these soils. =209. The French Method.=—The Schloesing method[142] as practiced by the French agricultural chemists[143] differs essentially from those already described in attempting to first free the silt from carbonates and organic matter. It is conducted as follows: One kilogram of the soil previously dried in the air, is taken and passed through a sieve of which the meshes are five millimeters. The agglomerated particles of earth are broken up by the hand. The pebbles are also taken out and weighed. The pebbles are then treated with hydrochloric acid until all effervescence is over. The insoluble part is dried and again weighed. The difference in weight gives the quantity of calcium carbonate contained on the external surface of the pebbles. The earth which passes the sieve of five millimeters mesh is next passed through a sieve having ten meshes to the centimeter. The masses on the sieve are broken up with the hand or with a pestle, in such a manner as to separate the fine agglomerated particles. The material which remains upon the sieve after being dried at 100°, is weighed. This gives the coarse sand. This is treated with hydrochloric acid as were the pebbles before, washed and the residue dried and weighed. The difference in weight gives the quantity of calcium carbonate adhering to the surface of the coarse sand. The mechanical analysis is continued with the matter which has passed the sieve with ten meshes to the centimeter and which consists of the soil, properly so-called. Ten grams of this are taken, dried at 100° until no further loss takes place and the moisture thus determined. Another ten grams are taken and placed in a capsule with a flat bottom, and from nine to ten centimeters in diameter. This is moistened with a small quantity of water in such a way as to make a paste. This paste is rubbed with the finger in fifteen cubic centimeters of water. Ten seconds after the stirring is completed the supernatant liquid is poured into a precipitating jar of about 250 cubic centimeters capacity, taking great care not to allow any particles to pass over which have been deposited during that time. This operation is repeated in the same way waiting about ten seconds each time before decanting, until the decanted liquor is almost perfectly clear. In this way the particles of different fineness are separated. The decanted portions contain the fine sand and clay. The remaining portion contains the sand and particles of medium fineness. This last part is dried, being kept at 100° until it has a constant weight. It is afterwards treated with dilute nitric acid to dissolve the calcium carbonate. When the carbonate is abundant, it is sufficient to determine it by difference which is done by washing the material, drying and weighing. But when the proportion of carbonate is very small and in consequence when its exact determination acquires a greater importance, it is better to determine the lime directly. For this purpose the part soluble in dilute nitric acid is collected, treated with ammonia and acetic acid and precipitated with ammonium oxalate. Details of this operation will be given in another part of this manual. In regard to the matter which is insoluble in nitric acid, it is composed chiefly of silica or silicates, and sometimes also of vegetable débris. The vegetable matter is determined by the incineration of the material which has been previously dried. The loss of weight gives the proportion of vegetable or organic débris contained in the soil and of combined water. The portion which has been decanted, the volume of which should not exceed 500 cubic centimeters, is treated with nitric acid until effervescence ceases. It is then left to digest for some time, in order to permit the whole of the carbonate to dissolve. It is next thrown upon a smooth filter about one decimeter in diameter. After filtration it is washed to secure the complete elimination of the soluble lime salts. The lime is determined in the filtered liquid. The insoluble portion contains the fine sand, the clay and humus bodies. In order to separate the three elements the precipitate which was received upon the filter, is rubbed with water, the filter is broken and all its contents washed through. The volume of wash water is made up to 200 cubic centimeters; two or three cubic centimeters of ammonia are added and the whole left to digest for two or three hours. The volume of the liquid is then made up to one liter with distilled water, vigorously shaking in such a way as to put all the matter in suspension. It is then left to settle for twenty-four hours. At the end of this time the supernatant liquid is decanted by the aid of a siphon. To the residue are added two cubic centimeters of ammonia and one liter of water. The matter is again brought into suspension and allowed to settle for twenty-four hours. The supernatant liquid is again decanted with a siphon, and added to the liquid previously removed. For ordinary soils two decantations are generally sufficient but when the soils contain a large quantity of clay it is convenient to decant three or four times. By an examination of the supernatant liquid it is easy to tell if the washings have been sufficiently prolonged. The decanted liquors contain the organic matter and that which it is convenient to call clay, which is constituted of very fine particles of sand and colloidal clay which play, in arable soil, a rôle somewhat like that of cement. These matters are estimated in the following manner: The liquor is first treated with nitric acid and the clay and the humic matters are precipitated together. They are collected upon a smooth filter one decimeter in diameter and washed with water. By means of a washing bottle all the solid matters which have stuck to the sides of the filter are finally collected in the bottom of it. Since the last washings pass the filter very slowly, they can be removed after the complete deposition of the matter they contain, by means of a pipette. When all the liquid is removed the filter is placed upon blotting paper, great care being taken to avoid desiccation, having in view only the elimination of the excess of humidity. The folds in the filter are then carefully smoothed out with the finger. The matter which has collected upon the filter is then removed completely with a washing bottle, placed in a dish and dried at 100° and weighed. After weighing, the mass is incinerated in a muffle in order to destroy the humic bodies. The difference in weight before and after incineration, gives the total weight of the humic bodies and since the diminution in weight comprises not only the weight of the humic bodies, but also the weight of the combined water which is lost during the process of incineration, there should be subtracted from the total loss of weight ten per cent of the weight of the residual mineral matter, which represents the water of composition of the hydrated silicate. =210. Statement of the Analysis.=—Schloesing in his original paper[144] recommends that the analysis be commenced with 1,000 grams of soil. The data of the analysis and the method of arrangement are illustrated by the following example. The physical examination of the earth having been completed as above, the results can be tabulated as follows: taken, 1,000 grams of dry earth, digested in water, thoroughly worked by hand, sifted, and passed through the meshes of the sieve by a stream of water, the meshes having a diameter of one millimeter. Dry residue, fifty-five grams, contains Pebbles │ 21 grams. „ Gravel │ 33 „ „ Organic débris│ 1 „ Sifted earth by difference, 1000 − 55 = │ 945 „ │———— │1000 grams. Humidity of the homogeneous paste, twenty-seven per cent. Then 945 grams of the dry sifted earth correspond to (945)/(1.00 − .27) = 1294.5 of paste. The analysis, therefore, should be carried on upon this weight or some aliquot part say 0.01 thereof; _viz._, 12.945 grams. 12.945 grams of the │1st.—Coarse sand dry │Noncalcareous 3.05 grams. paste after successive│giving by treatment │sand kneadings and │with acid and │ decantations furnish │ignition. │ dry: │ │ „ │ „ │Calcareous 1.19 „ │ │sand „ │ „ │Organic 0.08 „ │ │débris │2nd.—Fine elements decanted with the water, „ │their weight calculated by difference, 9.45 − │4.32 = 5.13 grams. _Treatment of the Fine Elements._—Treated by nitric acid until a complete decomposition of the calcareous matter is secured, filtered, washed, the residual matter collected upon a filter, and the liquid received in a two-liter flask, a little ammonia added, allowed to digest, the flask filled with distilled water, left for twenty-four hours at repose, and decanted: The decantation furnishes│1st.—A deposit of fine calcareous│3.14 grams. │sand weighing dry │ „ │2nd.—Clayey liquid giving after coagulation │by acid, filtration and drying 0.85 grams of │clay. │ │ Then: Total fine elements │5.13 grams. Fine elements determined │Fine calcareous sand 3.14│3.99 „ directly. │ │ „ │Clay 0.85│ „ │ │———— Fine calcareous sand by difference │1.14 „ Calculating these results to the original quantity of 1,000 grams the following data are obtained: RÉSUMÉ. One thousand grams of dry earth contain: Pebbles 21 grams. Gravel 33 „ Organic débris 1 gram. Fine earth 945 grams. ———— Total 1000 „ 945 grams of │Coarse sand 432 gms. │Noncalcareous sand 305 gms. fine earth │ │ contain: │ │ „ │ „ │Calcareous sand 119 „ „ │ „ │Organic débris 8 „ „ │ „ │Fine elements 513 gms.│Fine, noncalcareous sand 314 gms. „ │ „ │Clay 85 „ „ │ „ │Fine calcareous sand 114 „ │ │ —— │ │Total 1000 „ There are counted as clay all the elements which have remained in suspension in the water after a period of repose of twenty-four hours. In fact, these elements comprise a notable proportion of very fine sand which is not deposited during that time. In order that the liquid should become entirely freed from this sand it would be necessary to wait several weeks and even several months. Such a prolongation of the analysis is evidently inadmissible. The period of twenty-four hours of repose therefore has been adopted. This is merely conventional, in the same way that the period of ten seconds adopted for the precipitation of the gravel is conventional. But this convention is justified by the fact that the substance which is called clay presents, when it has a proper degree of humidity and cohesion, a plasticity entirely analogous to that property of natural clay. Moreover, as has already been said, that which is chiefly important in these analyses is the employment of processes always comparable among themselves in their results and generally followed. =211. The Belgian Method.=—The method of estimating the percentage of sand and clay practiced at the Gembloux Station[145] is essentially that recommended by Schloesing with a few minor modifications. With the ball of the thumb or with the finger, 100 grams of fine earth are rubbed with water in a porcelain capsule or mortar with a capacity of about 250 cubic centimeters. The suspended particles are poured off with the wash water and the process repeated five or six times, using in all about 200 cubic centimeters of water. The water containing the sediment is rendered slightly acid (hydrochloric acid) adding the acid in minute particles with constant stirring for about an hour in order to dissolve all the carbonate and to separate the organic acids from the bases with which they are combined. The liquid is allowed to remain at rest for five or six hours and a part of the liquor decanted to remove any supernatant particles of organic matter which may have passed the sieve in the original preparations of the sample. Filter through a smooth filter about twelve centimeters in diameter, wash until the chlorin has disappeared, and throw the filtrate away. Break the filter paper over the vessel in which the soil was treated with hydrochloric acid and wash all the contents of the filter into this vessel with as little water as possible (about 100 cubic centimeters), add five cubic centimeters of strong ammonia water, allow to stand for three hours, shaking from time to time and with distilled water make the volume up to 250 cubic centimeters. Stir vigorously with a glass rod or spatula, take this out and wash any adhering particles back, leave at rest for twenty-four hours, siphon the turbid liquid into a two-liter vessel. Make the volume up again to 250 cubic centimeters and treat as above described and repeat the operation until the water becomes clear after standing for twenty-four hours. Usually eight or ten washings are necessary. Wash the residual sand into a weighed dish, evaporate to dryness, ignite and weigh. The weight obtained divided by the weight of the original sample gives the per cent of sand. The sand is separated by sieves of varying fineness into coarse, fine, and pulverulent sand. Add to the ammoniacal liquor collected in the two-liter flask some powdered potassium chlorid (five grams per liter) to hasten the coagulation and rapid deposit of the clay. After twenty-four hours siphon the clear liquor, collect the deposited clay in a smaller vessel, allow to remain at rest and decant as much of the clear liquor as possible. Pass through a plain tared filter about nine centimeters in diameter, dry at 150° and weigh the clay. =212. The Italian Method.=—Schloesing’s method as carried out by the Italian chemists[146] is as follows: A kilo of earth dried in the air is passed through a sieve the threads of which are separated a distance of five millimeters; and with this the small pebbles are separated. With another sieve having spaces of one millimeter, the coarse sand is separated. The pebbles and sand are dried, weighed, treated with hydrochloric acid and again weighed in order to find the quantity of calcareous matter contained in them. In ten grams of this fine earth the humidity is determined by drying at 100°. Ten grams are mixed in a capsule with fifteen to twenty cubic centimeters of water and after eight to ten seconds the supernatant liquid is poured into a beaker having a capacity of 250 cubic centimeters. The same operation is repeated until there are contained in the beaker the fine sand and the clay, while the coarser sand remains in the capsule. This last is then dried and weighed and the quantity of calcium carbonate determined by treating it with diluted nitric acid. By means of calcination the organic matter is determined. The liquid decanted in the beaker, the volume of which must not surpass 200 to 250 cubic centimeters, is treated with nitric acid, filtered after some time, washed and the calcium is directly determined by precipitating the solution with ammonium oxalate. The part in the filter which contains the fine sand, the clay, and the humus material is mixed with water to a volume of about 200 cubic centimeters; there are then added to it two to three cubic centimeters of ammonia and after two or three hours it is diluted to a liter and strongly agitated. After twenty-four hours of rest it is decanted and the residuum is treated a second time with diluted ammonia, decanting after twenty-four hours. Ordinarily these two treatments suffice, if, however, the earth is very argillaceous, this operation should be repeated three and even four times. The clay which is found in the liquid suspended in colloidal form coagulates and is precipitated by adding thirty to forty cubic centimeters of a saturated solution of potassium chlorid, while the humus substance, under the influence of the ammonia remains dissolved. Sestini found that the method of Schloesing was the only one which indicated exactly the quantity of clay in the soil. He modified this method by reducing the time of rest from twenty-four hours, as proposed by Schloesing, to only twelve hours, a reduction which in his opinion does not in the least impair the exactness of the method. Sestini also proposes twelve treatments instead of six. SEPARATION OF THE SOIL PARTICLES BY A LIQUID IN MOTION. =213. General Principles.=—The laws, already discussed, applying to the subsidence of a solid particle in a liquid, are equally applicable to the separation of the particle by imparting a motion to the liquid at a given rate. If a solid particle subside in a given liquid at the rate of one millimeter per second it follows that this particle will remain at rest if the liquid be set in motion upward with a like velocity. If the velocity be greater the particle will be carried upward and eventually out of the containing vessel. Such a particle is said to have a hydraulic value of one millimeter per second. If there be a perfect separation of a soil into its constituent particles and no subsequent flocculation, all the particles of one millimeter hydraulic value and less will be separated by a current of the velocity mentioned. The general principles on which the separation rests, therefore, are the securing of the proper granulation of the sample and the maintenance of a fixed velocity of the current until the separation is finished. The separation must be commenced with a period of subsidence so as to remove first of all the suspended clay or impalpable particles. The velocity can then be increased in a certain fixed ratio to secure a separation into particles of any required hydraulic value. =214. Nöbel’s Apparatus.=—One of the earliest methods of separating the soil particles by a moving liquid is that of Nöbel.[147] The apparatus is shown in Fig. 28. The four separating vessels 1, 2, 3, 4 are of glass, pear shaped, and have a relative capacity of 1³, 2³, 3³, 4³, or 1 : 8 : 27 : 64. No. 4 has an outlet tube leading to the beaker B, of such a capacity as to allow the passage of just nine liters of water in forty minutes, constant pressure being maintained by means of a Mariotte’s bottle or of the constant level apparatus A, _a_, _b_, which is connected with the main water supply through the tube _a_ by means of a rubber hose. The reservoir C should hold about ten liters. The sample of soil to be separated should be previously boiled and passed through a sieve having circular openings one millimeter in diameter. The flask in which the sample is boiled is allowed to stand for some time when the muddy supernatant liquid is poured into elutriator No. 2 and the remaining sediment washed into No. 1. No. 1 is filled with water by connecting it with the water supply and opening the pinch-cock _p_. The water is carefully admitted until the air is all driven out and Nos. 1 and 2 connected. The cock _p_ is then opened and the vessels all filled, and the water allowed to run into B for forty minutes, the level being maintained uniformly at A. FIGURE 28. NÖBEL’S ELUTRIATOR. ] Of the water used, four liters are found in the elutriating vessels and nine liters in the receiving vessel No. 5. The apparatus is left standing for an hour until the liquid in the elutriators is clear and the portions in each vessel are received on weighed filters dried at 125°, and the weight of each portion determined. It is recommended that the loss on ignition of each part be also determined. The separated particles thus secured are classified as follows: No. 1. Débris and gravel. No. 2. Coarse sand. No. 3. Fine sand. No. 4. Clayey sand. No. 5. Finest parts or clay. Although the method of Nöbel has been much used, the results which it gives are entirely misleading. The convection currents produced in the conical vessels by the passing water and the flocculation of the soil particles prevent any sharp separation into classes of distinct hydraulic value. The process may be useful for a qualitative test, but its chief claim to a place in this manual is in its historic interest arising from its use in the first attempts at silt analysis. =215. Method of Dietrich.=[148]—The difficulties attending the silt separation by the Nöbel method, led Dietrich to construct an apparatus in which the sides of the elutriating vessels were parallel, but these vessels, with the exception of the first, were not set in an upright position. FIGURE 29. DIETRICH’S ELUTRIATOR. ] The apparatus (Fig. 29) consists of a series of cylindrical vessels connected by rubber tubing. The elutriators are of the following dimensions: No. 1. Seventeen centimeters long, 2.8 centimeters in diameter, position upright. No. 2. Thirty-four centimeters long, four centimeters in diameter, inclined 67°.5. No. 3. Fifty-one centimeters long, 5.2 centimeters in diameter, inclined 45°. No. 4. Sixty-eight centimeters long, 6.4 centimeters in diameter, inclined 22°.5. The rubber tubes passing from one vessel to the other are furnished with pinch-cocks so that each one of the elutriating vessels can be shut off from the others and independently removed from the circuit. The stream of water is made to pass through the apparatus under a constant pressure of one meter. Only the fine earth, boiled with water or hydrochloric acid, is to be placed in the apparatus. The part coming through a sieve with a mesh 0.67 millimeters is to be used and placed in No. 1. About thirty grams of soil, are employed for each elutriation. Before adding the soil, the air is completely removed from all parts of the apparatus by connecting it with the water supply and allowing it to be filled with water. The rate of flow is controlled by the orifice of the last effluent tube and the analyst is directed to continue the operation until the effluent water collected in the beaker glass (5) is clear. The particles then remaining in each of the vessels are collected separately. The author of the method claims that in respect of likeness of particles the results are especially gratifying and that duplicate analyses give results fully comparable. The process, however, has not commended itself to analysts, but it marks a distinct progress toward the principles of later investigators. Had each of the elutriating vessels been placed upright and the rate of flow determined, the apparatus of Dietrich would have served, to a certain extent, for the more rigid investigations of his successors. =216. Method of Masure.=—The sifted earth, from ten to fifteen grams, is carefully mixed with 200 cubic centimeters of water. It is then introduced into a doubly conical elutriator B, Fig. 30, of about 250 cubic centimeters capacity. A current of distilled water is allowed to flow from a Mariotte’s bottle, A, which secures a regular and constant flow. The bottle A is joined to the elutriator B by means of a rubber tube and the vertical glass tube D, the top of which is expanded into a funnel for the purpose of receiving the water from the Mariotte flask. The current of water flowing upward through the elutriator B carries in suspension the most finely divided particles of clay, and these are collected with the emergent water in the receiver C. The sand and coarser particles of clay remain in the elutriator. The water flows out by the tube F, the diameter of which should be less than that of D. When the emergent water becomes limpid the operation is terminated. After the apparatus is disconnected, the water is decanted from the sand in the elutriator, and the whole residue is weighed after drying for two hours at 110°. FIGURE 30. MASURE’S SILT APPARATUS. ] The fine soil collected in C may also be separated and weighed, for control, after drying as above. The pebbles and coarse sand separated by the sieves should also be weighed. By this process the soil is separated into four portions; _viz._, (1) Pebbles. (2) Coarse sand. (3) Fine sand and other materials not carried off by the current of water. (4) Fine soil, carried into the receiver C. =217. Method of Schöne.=—The method of Schöne[149] is based on the combination of a cylindrical and conical separatory tube through which the flow of water is regulated by a piezometer. If, in the process of silt separation, the water move perpendicularly upward with a given velocity, _e.g._ = v the separation is dependent: (1) On the volume of the silt particles, (2) On their specific gravity, and, (3) On their state of disintegration. If it be assumed that the silt particle is a sphere with a diameter = d, then according to Newton’s law of gravity, the following formula would be applied: d = v² ((3Z)/(4g (S − 1))). FIGURE 31. SCHÖNE’S ELUTRIATOR. ] In the above formula Z = a coefficient which depends on the condition of the surface against which the hydraulic pressure or resistance works, in this case a sphere; g = the acceleration of gravity equivalent to 9.81 meter; and S = the specific gravity of the particle. This expression signifies that in a given case, the velocity of the current in the apparatus is just sufficient to counteract the tendency of a given particle to sink. All particles of a smaller diameter, in such a case, will be carried on by the current, while all of a greater diameter would separate by sedimentation. These theoretical conditions are not met with in practice where silt particles of all shapes and degrees of aggregation abound. These particles, whatever their shape, may be said to have the same hydraulic value when carried by the same current. It is necessary, therefore, to secure some uniform standard of expression to assume a normal form of particle and a normal specific gravity. For the form, a sphere is evidently the normal which must be considered and for specific gravity that of quartz is taken; _viz._, 2.65. The mean coefficient for Z may also be placed at 0.55, although slightly different values are ascribed to it. Substituting these values in the formula, it is reduced to the expression; d = v² × 0.0000255 millimeters. It can, therefore, be said that by this or that velocity of the current, silt particles will be removed of this or that diameter, it being understood that all particles of equal hydraulic value to spherules of quartz of the given diameter are included in each class. In order to have the theoretical formula agree with the results of analysis it is necessary to modify it empirically to read d = v^{⁷⁄₁₁} × 0.0314 millimeters. This formula is found to agree well with the results obtained for all velocities between 0.1 millimeter and twelve millimeters per second, the ordinary limits of silt separation. _The Apparatus._—The conic-cylindrical elutriating vessel A, B, C, D, E, F, G, Fig. 31, is of glass. The part B, C, is cylindrical, ten centimeters in length and as nearly as possible five centimeters in diameter. The conical part C, D, is fifty centimeters in length. Its inner diameter at D must not be greater than five centimeters nor smaller than four centimeters. The bend, D, E, F, should have the same diameter; _viz._, four to five centimeters. The part A, B, C, D, and D, E, F, G, may be made of separate parts and joined by a rubber tube. _Outflow Tube and Piezometer._—The outflow tube and piezometer, H, J, K, L, is constructed as shown in Fig. 32. It should be made of barometer tubing having an internal diameter of about three millimeters. The tube is bent at J at an angle of forty to forty-five degrees. The knee J must be as acute as possible not to interfere with the inner diameter. The form and especially the magnitude of the outlet are of great importance. It must be circular and nearly 1.5 millimeter in diameter. It must not be larger than 1.67 millimeter nor smaller than 1.5 millimeter. The opening should be so made as to direct the stream of outflowing liquid in the direction shown by the arrow. FIGURE 32. SCHÖNE’S ELUTRIATOR, OUTFLOW TUBE. ] The piezometer L, K is parallel to the arm H, J, of the delivery tube. Its graduation has its zero point in the center of the outlet K. It commences with the one centimeter mark. From one to five centimeters it is divided into millimeters, from five to ten centimeters into one-fourth centimeter, from ten to fifty centimeters into one-half centimeter, and from fifty to 100 centimeters into centimeters. The dimensions given are those required for ordinary soils and for velocities ranging from two-tenths millimeter to four millimeters per second. For greater velocities, a delivery tube with a larger outlet must be used and the piezometer must be of greater internal diameter than indicated. FIGURE 33. SCHÖNE’S ELUTRIATOR, ARRANGEMENT OF APPARATUS. ] _Arrangement of the Apparatus._—The apparatus is conveniently mounted as shown in Fig. 33, giving front and side views of all parts of apparatus in position ready for use. When numerous analyses are to be made much time is saved by having a number of apparatus arranged _en batterie_. _The Sieve._—The soil, before being subjected to elutriation, should be passed through a sieve of which the meshes are 0.2 millimeter square. _The Process._—To measure the diameter of the cylinder, two marks are made with a diamond upon the glass which are distant from each other a certain space, for instance, _h_ centimeters. The space between these two marks is filled with water exactly measured. Suppose that a cubic centimeters were used, then the diameter is determined by the formula: D = √(4_a_)/(π_h_) centimeters. In order to determine that the elutriating cylinder is strictly comparable in all its parts this measurement should be made upon several parts thereof. The apparatus should now be tested in regard to the quantity of liquid which it will deliver under a given pressure in the piezometer. By means of the stop-cock H the flow of water is so regulated that the outflow at _c_ can be measured at a given height of the water in the piezometer. Suppose that _a_ cubic centimeters of water flow in _t_ seconds, then the quantity which would flow in one second is determined by the formula, Q = a/t cubic centimeters. Since according to the law of hydraulic outflow the quantities are proportional to the square root of the height of the column it is easy to compute from any given height the quantity which will flow from any other one desired. For the retardation due to capillary attraction, it is sufficient, in general, to take it in a constant quantity; if this constant quantity be represented by C, the observed height of the water in the piezometer by _h_, and the quantity of water flowing out by Q, the data required for any given velocity can be calculated from the following proportion: √(_h_₁ − C) : √(_h_₂ − C) = Q₁ : Q₂. It is necessary to compute the magnitude of this constant C which is to be subtracted. This is accomplished by measuring the quantity of water which flows out at two different heights of the column in the piezometer. From the foregoing proportion, the value of C is as follows: C = (Q₁² _h_₂ − Q₂² _h_₁)/(Q₁²) − Q₂²) centimeters. The value of C can be the more exactly determined as _h_₁ is greater and _h_₂ smaller. It is best to choose the lowest height from which an exact reading can be made; that is, by which the regular rise and fall of the level of the water in the piezometer (in consequence of the formation of drops) just begins to disappear. This usually takes place when _h_₂ = 1.5 centimeter to 1.7 centimeter. For the higher value _h_₁ it is best to take about 100 centimeters. Suppose, for example, the following results are obtained: Height of column to be Observed height. Observed quantity of subtracted outflow. due to capillary attraction. _h₂_ _h₁_ Q₁ cubic Q₂ cubic centimeters. centimeters. centimeters. centimeters. centimeters. 80 1.6 5.53 0.406 1.21 100 1.6 6.13 0.484 1.17 80 1.8 5.53 0.406 1.19 100 1.8 6.13 0.484 1.19 The same quantity of water which flows out in a unit of time passes also at the same time over a cross section of the elutriating cylinder. The diameter of this cylinder being D the equation is derived _v_ = Q(4)/(πD²) centimeters. Since the velocity in the elutriating cylinder v is directly as the quantity of water overflowing so is _v_ : _v_ₙ = √(_h_ − C) : √(_h_ₙ − C); then _v_ₙ = √(_h_ₙ − C) (_v_)/(√(h − C)) and _h_ₙ = _v_ₙ²((_h_ − C)/(_v_²) + C. The constant (_h_ − C)/(_v_²) is obtained from the means of a number of estimations; for example as illustrated in the following data: Observed Corresponding velocity quantity of in elutriating cylinder Constant. Observed height, outflow, cubic of 4.489 centimeters (_h_ − centimeters. centimeters. diameter, millimeters. C)/(2) 1.6 0.406 0.0257 621 1.8 0.484 0.0306 652 80.0 5.530 0.3490 647 100.0 6.130 0.3870 660 ——— Mean 645 Then are obtained the following values of _h_ₙ and _v_ₙ: _h_ₙ = 645(Vₙ²) + 1.19 centimeters. and _v_ₙ = √(_h_ₙ − 1.19) × 0.0394 centimeters. In order to be able easily and rapidly to judge under what pressure the outflow has taken place in any particular instance, a larger number of values are computed with the help of the formula given and placed together in tabular form. As an example the following table may serve which was computed for one of the apparatus used. Usually it will be sufficient to test the apparatus for four different heights and then to interpolate the values for all the others. The numbers marked with a star in the table are those which were determined by experiment; the others were calculated. Height of column Velocity in the elutriating Corresponding diameter of in piezometer. cylinder of 4.489 silt particles. _d_ = _h_ centimeters diameter. _v_ v(⁷⁄₁₁)0.0314 millimeters. centimeters. Observed, Calculated, millimeters. millimeters. millimeters. 1.5 0.222 0.220 0.0120 1.6 0.257* 0.252 0.0131 1.7 0.284 0.281 0.0140 1.8 0.306* 0.307 0.0148 1.9 0.323 0.332 0.0155 2.0 0.346 0.355 0.0162 2.5 0.427 0.451 0.0185 3.0 0.531 0.530 0.0210 3.5 0.577 0.599 0.0227 4.0 0.650 0.660 0.0236 4.5 0.694 0.717 0.0254 5.0 0.751 0.769 0.0265 6.0 0.850 0.864 0.0286 7.0 0.942 0.950 0.0304 8.0 1.050 1.028 0.0320 9.0 1.120 1.101 0.0334 10.0 1.170 1.169 0.0347 15.0 1.490 1.460 0.0400 20.0 1.730 1.710 0.0441 25.0 1.940 1.920 0.0476 30.0 2.100 2.110 0.0506 35.0 2.310 2.290 0.0532 40.0 2.460 2.450 0.0556 45.0 2.610 2.610 0.0578 50.0 2.770 2.750 0.0598 60.0 3.030 3.020 0.0635 70.0 3.290 3.270 0.0667 80.0 3.490* 3.500 0.0697 90.0 3.710 3.710 0.0724 100.0 3.870* 3.920 0.0749 Suppose the problem is by means of the apparatus tested above, to separate into a number of groups a mixture of silt particles, whose hydraulic values are found between the following diameters: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07 millimeters. The table will show at once under what pressure of water the piezometer must be placed in order to give the values; _viz._, 1.4, 2.8, 7.0, 15.0, 29.0, 53.0, and 83.0 centimeters respectively. The apparatus described above, is adapted for velocities in the elutriating cylinder varying from two-tenths millimeter to four millimeters per second. The largest silt particles which can be separated by the velocities given above, have approximately a diameter of 0.08 millimeter. For the separation of larger particles a sieve can take the place of the silt apparatus. If, however, it be desired to subject larger particles to silt analysis, the dimensions of the elutriating cylinder and of the outlet of the delivery tube must be changed accordingly. _Preparation of Sample._—The conduct of silt analysis of natural soils must, in certain cases, be preceded by a special treatment of the sample. If the latter be rich in humus the organic substance must previously be separated as completely as possible. With sandy soils this can be accomplished by ignition. With clayey soils, on the contrary, it is to be performed by boiling the soils at least one hour with water which contains from one to two per cent of free alkali. Soils which contain lime must also be subjected to treatment with dilute hydrochloric acid, and the hydrochloric acid must be as carefully removed, as possible before the sample is subjected to elutriation; afterward follows the boiling of the sample in the ordinary way with water. This, of course, can be omitted when it has already been treated with boiling dilute alkali. It is also important to remove the larger particles by a sieve before the elutriation begins. It is well to pass a sample through a sieve after it has been boiled, by which all particles of a larger diameter than 0.2 millimeter are removed. This will usually require about one liter of water and this water should be allowed to rest from one to two hours and poured off with the suspended material which it contains. Only what subsides should be brought into the apparatus. In rinsing the sample as much water must be used as will fill the apparatus up to its cylindrical portion. After the sample has been placed in the apparatus, the water is allowed slowly to enter, being careful to avoid reaching more than the lowest required velocity, until the outflow begins. The water then is so regulated by the stop-cock as to bring it to the desired height in the piezometer. This being accomplished, the different velocities which have been decided upon for separating the particles of silt are used one after the other, as soon as all the silt which can be removed at each given velocity, has been secured. From three to five liters of water will be required for the separation of each class of particles. Sometimes the reading of the height of the water in the piezometer is difficult; as, for instance, when foam or bubbles accumulate therein. These bubbles can be removed by simply blowing into the tube, or dropping into it a little ether. The outflow of water can be received in vessels, beaker glasses, or cylinders, in which it is allowed to subside. The finest particles which remain in suspension in the water are best determined by difference. If it be desired to weigh them directly, the water can be treated with ammonium bicarbonate until it contains from one to two per cent thereof. The precipitation then takes place in a few hours. The collection and weighing of silt particles are accomplished in the usual way. That which finally remains in the elutriating vessel is taken out after the end of the operation by closing the stop-cock, removing the stoppers with the piezometer tube, pouring the contents of the elutriating vessel into a beaker glass and rinsing out carefully all adhering particles. Examples of the working of the apparatus follow: The soil was taken from the Imperial Russian Agricultural Experimental Institute at Gorki. It was a fine clay sand and was carefully treated with hydrochloric acid. The results of the analysis are given in the following table: Velocities Largest diameter of the Percentage of silt product employed in collected particles in obtained in repeated millimeters. millimeters. elutriations. 0.25 0.012 13.4 12.6 11.9 0.5 0.020 9.1 8.7 9.5 1 0.032 21.0 21.4 20.8 2 0.050 30.4 29.8 31.7 3 0.063 16.7 16.1 15.5 4 0.076 5.3 5.5 5.5 Residue 4.2 4.9 3.8 ————— ———— ———— Total 100.0 99.0 98.7 Holthof modifies the apparatus of Schöne by putting into the lower mouth of the elutriator a little mercury so that the particles of earth are deposited upon its surface and are thus better agitated and washed by the current of water. =218. Mayer’s Modification of Schöne’s Method.=—An improvement of Schöne’s apparatus in the direction of greater simplicity has been tested by Mayer[150] with satisfactory results: The apparatus, (Fig. 34), consists of a glass vessel having a glass stop-cock at the bottom for admitting the water. For a distance of twenty centimeters the sides of the tube are parallel and the diameter about one centimeter. Next for a distance of fifty centimeters the tube is conical expanding at a regular rate until the internal diameter reaches five centimeters. For a distance of ten centimeters the vessel is again strictly cylindrical and it is in this cylindrical portion that the separation of the different constituents takes place. The vessel is then rapidly narrowed until it carries the stopper A two centimeters in diameter. This stopper carries two glass tubes, one F bent downward to conduct the overflow into the receiving vessels, and one H for the purpose of regulating the rate of overflow by the height of the column of water therein. The orifice of the overflow tube F should be so regulated that with a pressure of five centimeters water in H, one liter shall pass over in ten minutes. FIGURE 34. SCHÖNE’S APPARATUS FOR SILT ANALYSIS, MODIFIED BY MAYER. ] If the separation be conducted in an apparatus thus mounted and graduated with a pressure of two centimeters in H all that portion of the soil which can properly be called clay will pass over. The fine earth, that is, earth in which all coarse particles have been removed by proper sifting, is used in ten-gram lots for each experiment. The residue, after the separation is complete, consists of pure sand or at least pure sand mixed with humus. Before the fine earth is placed in the apparatus, the calcium carbonate therein is removed with hydrochloric acid. The treatment with hydrochloric acid, however, is not to be recommended in soil containing many undecomposed particles of calcium carbonate or dolomite for then large additions to the silt output might be made from these particles, which could not be regarded as coming from the soil as it actually exists. For alluvial soil, however, previous treatment with hydrochloric acid is recommended unconditionally. =219. Schöne’s Method as Practiced by Osborne.=—The apparatus used by Osborne[151] was obtained from Germany and was similar to that described by Schöne in his original paper, except that it was furnished with a second elutriating tube as suggested by Orth. The modification made by Orth consists, essentially, of a second elutriating tube with straight sides into which the bulk of the soil is introduced, only the final part being carried over into the Schöne’s tube proper. Water is supplied to the apparatus under constant pressure by means of a Mariotte’s bottle. The preliminary treatment recommended by Schöne is omitted, as these steps have been shown to be undesirable, on account of affecting the accuracy of the results. Twenty grams of the air-dried soil are passed, under water, through a sieve of one-fourth millimeter mesh. That part of the soil which remains in suspension after being sifted is placed at once in the Schöne’s tube of the apparatus, the coarser portion being rinsed into the Orth tube. The current is regulated so that the largest particles of quartz carried off have an average diameter of 0.01 millimeter. When all is carried off that can be removed at this rate the current is increased until the largest quartz grains passing off have a diameter of 0.05 millimeter. As noticed by Hilgard with Schulze’s apparatus, secondary currents are formed during the process of elutriation which descend along the walls of the conical portion of the Schöne’s tube and some distance along the sides of the cylindrical portion. The tendency of these currents is to produce globular aggregates of particles which fall to the bottom. They are broken up from time to time by increasing the velocity of the current but even this method fails to disintegrate a considerable quantity of them. =220. Statement Of Results.=—Two samples of soil from the garden of the experiment station analyzed by Schöne’s method gave the following proportions of sediment. In the table the term clay is used to designate all that part of the soil which has diameters less than 0.01 millimeter and which remains suspended after twenty-four hours standing in water having a depth of 200 millimeters. SOIL, FROM GARDEN OF THE EXPERIMENT STATION.—NOT BOILED. Analyses with the Schöne-Orth Elutriator. _A._ _B._ _C._ Above 0.25 millimeter 48.82 48.82 48.82 0.25–0.05 27.36 29.94 22.37 0.05–0.01 millimeter 8.63 6.07 13.70 0.01 millimeter and less depos. 7.36 7.31 7.20 Clay (by difference) 1.00 1.03 1.08 Loss on ignition 6.83 6.83 6.83 —————— —————— —————— 100.00 100.00 100.00 The last column _C_ represents the average of three direct beaker elutriations according to the method of Osborne. The differences which these figures show are found to be due to imperfect separation of the finer grades from the coarser and even when the various fractions separated by the Schöne method are subjected to beaker elutriation and the portions separated from them added to the grades to which they properly belong the Schöne elutriator was found to effect far less exact separations than the beaker method. Samples of prairie soil from Mercer County, Ill., not boiled, were examined by the two methods with the following results: Schöne-Orth Beaker elutriation. method. Above 0.25 millimeter 0.76 0.62 0.25–0.05 millimeter 11.25 2.42 0.05–0.01 millimeter 52.65 43.58 0.01 millimeter and less deposited 14.84 31.58 Clay 4.44 5.81 Loss on ignition 14.49 14.49 ————— ————— 98.43 98.50 In this case it is seen that Schöne’s method varies considerably from the beaker method and if the beaker method be regarded as correct the Schöne method is evidently less reliable. In the next table are given the data of the examination of brick clay from North Haven, Conn., by the two methods. BRICK CLAY FROM NORTH HAVEN, CONN. Schöne-Orth elutriation. Beaker method. Above 0.25 millimeter 1.02 1.02 0.25–0.05 millimeter 3.91 0.76 0.05–0.01 millimeter 29.63 20.95 0.01 millimeter and less 58.58 71.01 Loss on ignition 6.60 6.60 ————— —————— 99.74 100.34 The failure of the Schöne method to give the results obtained by the beaker method is ascribed to the fact that it is impossible for the current of the strength used to disintegrate the clay and further that the particles after they are once separated tend to coalesce by the currents produced by the elutriating process. =221. The Berlin-Schöne Method.=—Osborne has also made a study of the Schöne method as modified by the Bodenlaboratorium of Berlin. The directions for the analysis by this laboratory method are as follows: Five hundred grams of the soil are sifted through a sieve with circular holes two millimeters in diameter. Of the earth passing the sieve from 30 to 100 grams are boiled in water with constant stirring from one-half to one hour or longer, according to the character of the soil. The finer the texture of the soil the smaller the quantity taken and the longer the time of boiling. Treatment with acids or alkalies is not practiced. The finer portion of the soil remaining suspended in the water, after boiling, is poured into the Schöne tube, the remaining coarse part is rinsed into the Orth tube. The clay, together with the finest sand, is collected in a separate vessel, the water in which it is suspended is evaporated and the residue after drying in the air is weighed. The rest of the operation is carried out as previously described except that the products of elutriation are not ignited but weighed air dried, in order that they may be further examined, chemically if desired. By proceeding in this manner the following results were obtained: SOIL, FROM GARDEN OF THE EXPERIMENT STATION, BOILED FORTY-FIVE MINUTES. Separations by the Berlin-Schöne method. Air-dried. Ignited. Above 0.05 millimeter 72.63 71.76 0.05–0.01 millimeter 14.17 12.53 0.01 millimeter and less 12.97 9.38 Loss on ignition 6.83 ————— ————— 99.77 99.50 For the sake of comparing the mechanical separation attainable by this procedure with those yielded by other methods, the air-dried products were ignited and again weighed and examined. By subtracting from the ignited portion above 0.05 millimeter, 49.37 per cent, the amount of this soil that remained on a 0.25 millimeter sieve, the fraction between 0.25 millimeter and 0.05 millimeter is found, and the separations in this analysis may be compared with those previously obtained by the beaker method as follows: SOIL FROM GARDEN OF EXPERIMENT STATION. │ │ Beaker Method. │ ——————————————————————————————————————— Berlin-Schöne,│ Boiled Pestled, not Not boiled boiled │ twenty-three boiled. nor pestled, forty-five │hours, average average of minutes. │ of four three │ analyses. analyses. │ Above 0.25 49.37│ 47.77 48.82 48.82 millimeter │ 0.25–0.05 21.39│ 20.75 22.44 22.37 millimeter │ 0.05–0.01 12.53│ 11.18 12.55 13.70 millimeter │ <0.01 clay 9.38│ 13.47 9.36 8.28 included │ Loss on 6.83│ 6.83 6.83 6.83 ignition │ ───────────────────────────┼─────────────────────────────────────────── 99.50│ 100.00 100.00 100.00 Osborne concludes from the above facts that the Berlin-Schöne method, while showing close agreement with the beaker method, does not give results which are identical with that method. On subjecting portions separated by the Berlin-Schöne method to the beaker analysis additional separations were secured. In the case of heavy loams the inability of the Berlin-Schöne method to effect even a rough or approximate separation of the several grades becomes very conspicuous. =222. Method of Hilgard.=—Two important principles lie at the foundation of this method; _viz._, 1, the use only of separating vessels of true cylindrical shape and 2, the employment of a mechanical stirrer to break up the floccules formed during the process of separation. The points in the apparatus to be considered are uniformity of the cross section of the elutriator at every point, exact perpendicularity of position, careful control of the rate of flow and continuous operation of the mechanical stirrer. According to Hilgard’s observations the stirring due to the current of water alone is not sufficient to break up the floccules unavoidably formed during the separation, while any inclination of the sides of the elutriating vessel from the perpendicular due either to a conical shape or false position favors in the highest degree the formation of floccules due to reflex currents formed in the body of the liquid. In order to carry out the idea suggested by Türschmidt of substituting for the accidental and indefinite products usually appearing in the statements of silt analyses sediments of known and definite hydraulic value a constant head of water is used, secured by means of a Mariotte’s bottle connecting with the tube delivering the current through a cock provided with an arm moving on a graduated arc. According to Hilgard the separation of sediments by the method of subsidence does not possess the analytical accuracy of the moving liquid method, especially when the latter is combined with mechanical stirring. The subsidence method requires close and continuous attention and in the case of fine sediments tending to flocculation the difficulties of the method are greatly increased. The views of Hilgard in respect of the laboriousness of the subsidence method lose, however, some of their force since the modifications of Osborne have come into use. The simplicity and cheapness of the apparatus required for subsidence give it at the start many advantages over the more elaborate process with a churn elutriator. For rigid scientific investigation, however, the method of Hilgard is commended as a standard of comparison in all cases. FIGURE 35. HILGARD’S CHURN ELUTRIATOR. ] =223. The Elutriator.=—The instrument devised by Hilgard[152] for the purpose of breaking up these flocculent aggregates is shown in figure 35, together with the simpler form, a Schöne’s elutriator, figure 36, which can serve for grain sizes above eight millimeters hydraulic value. The latter is conveniently selected so as to have half the cross-section of the former, so that with the same position of the index lever the velocity will be just doubled. The cylindrical glass tube, of about forty-five millimeters inside diameter at its mouth, and 290 to 300 millimeters high, has attached to its base a rotary churn consisting of a brass cup, shaped like an egg with point down, so as to slope rather steeply at base, and triply perforated; _viz._, at the bottom for connection with the relay reservoir, and at the sides for the passage of a horizontal axis bearing four grated wings. This axis, of course, passes through stuffing boxes, provided with good thick leather washers, saturated with mutton tallow. These washers, if the axis runs true, will bear a million or more revolutions without material leakage. When a beginning is noted additional washers may be slipped on without emptying the instrument, until the analysis is finished. For the finest sediments, from five to six hundred revolutions per minute is a proper velocity, which may be secured by clock work, turbine or electric power. The driving pulley should not be directly connected with the axis, both because it is liable to cause leakage, and because it is necessary to be able to handle the elutriator quickly and independently. This is accomplished by the use of “dogs” on the pulley and churn axis. For the grain sizes of one to eight millimeters hydraulic value lower velocities are sufficient; too low a velocity causes an indefinite duration of the operation and may be recognized by the increase of turbidity as the velocity is increased. As the whirling agitation caused by the rotation of the dasher would gradually communicate itself to the whole column of water and cause irregularities, a wire screen of 0.8 millimeter aperture is cemented to the lower base of the cylinder. The relay vessel should be a thick, conical test glass with foot; its object is to serve as a reservoir for the heavy sediments not concerned at the velocity used in the elutriator tube, and whose presence in the latter or in its base, the churn, would only cause abrasion of the grains and changes of current velocity, such as occur in the apparatus of Schöne, and compel the current measurement of the water delivered. It is connected above with the churn by a brass tube about ten millimeters in clear diameter, so as to facilitate the descent of the superfluous sediments, which the operator, knowing the proportion of area between the connecting tube and elutriator, can carry to any desired extent; thus avoiding the disturbance of the gauged current velocities, as well as all material abrasion. FIGURE 36. IMPROVED SCHÖNE’S APPARATUS WITH RELAY. ] A glass delivery tube should extend quite half way down the sides of the relay vessel, to insure a full stirring up of the coarse sediments when required. By means of a rubber hose, not less than twenty inches in length, this delivery tube connects with the siphon carrying the water from near the bottom of the Mariotte’s bottle, a ten-gallon acid carboy. A stop-cock provided with a long, stiff index lever, moving on an empirically graduated arc, regulates the delivery of water through the siphon. Knowing the area of the cross section of the elutriator tube, the number of cubic centimeters of water which should pass through it in one minute, at one millimeter velocity, is easily calculated, and from this the lever positions corresponding to other velocities are quickly determined and marked on the graduated arc. The receiving bottle for the sediments, also shown in the figure, must be wide and tall, so as to allow the sediment to settle while the water flows from the top into the waste pipe. The receiving funnel tube must dip nearly to the bottom of the bottle. Thus arranged, the instrument works very satisfactorily, and by its aid soils and clays may readily be separated into sediments of any hydraulic value desired. But in order to insure correct and concordant results, it is necessary to observe some precautions; _viz._, (1) The tube of the instrument must be as nearly cylindrical as possible and must be placed and maintained in a truly vertical position. A very slight variation from the vertical at once causes the formation of return currents, and hence of molecular aggregates on the lower side. (2) Sunshine, or the proximity of any other source of heat, must be carefully excluded. The currents formed when the instrument is exposed to sunshine will vitiate the results. (3) The Mariotte’s bottle should be frequently cleansed, and the water used be as free from foreign matters as possible. For ordinary purposes it is scarcely necessary to use distilled water. The quantities used are so large as to render it difficult to maintain an adequate supply, and the errors resulting from the use of any water fit for drinking purposes are too slight to be perceptible, so long as no considerable development of the animal and vegetable germs is allowed. Water containing the slimy filaments of fungoid growths and moss protonema, algae, vorticellae, etc., will not only cause errors by obstructing the stop-cock at low velocities, but these organisms will cause a coalescence of sediments that defies any ordinary churning, and completely vitiates the operation. (4) The amount of sediment discharged at any time must not exceed that producing a moderate turbidity. Whenever the discharge becomes so copious as to render the moving column opaque, the sediments assume a mixed character, coarse grains being, apparently, upborne by the multitude of light ones whose hydraulic value lies considerably below the velocity used, while the churner also fails to resolve the molecular aggregates which must be perpetually reforming where contact is so close and frequent. This difficulty is especially apt to occur when too large a quantity of material has been used for analysis, or when one sediment constitutes an unusually large portion of it. Within certain limits the smaller the quantity employed the more concordant are the results. Between ten and fifteen grams is the proper amount for an instrument of the dimensions given above. =224. Preparation of the Sample.=[153]—In some cases simple sifting will be sufficient to prepare the air-dried soil for the elutriator. In most cases, however, some mechanical aid must be invoked to secure particles of sufficient fineness. Nothing harder than a rubber pestle should be used and care must be taken not to break up any calcareous or ferruginous masses which the particles of fine soil may contain. The use of water in this mechanical attrition should be avoided, if possible, but in some heavy clay and adobe soils wetting becomes necessary. In this case the parts separated by the sieve are collected separately and the turbid mass removed by water and dried for further examination. A sieve of 0.5 millimeter mesh is recommended as the best because that is almost exactly the diameter of the particles passing off at the maximum velocity of sixty-four millimeters per second to which the elutriator is adapted. The particles passing the 0.5 millimeter mesh are called fine earth. =225. Preparation by Boiling.=—The method of preparation by boiling may be applied to all samples of fine earth. The fact pointed out by Osborne, that diffusibility of some clays is diminished by long boiling, renders it important to restrict the time of this operation as much as possible. With most soils from eight to fifteen hours will be long enough, occasionally extending to even twenty-four hours. A thin long-necked flask of about one-liter capacity should be used; filled three-quarters full with distilled water and the sample of soil added. The flask is supported over the lamp on a piece of wire gauze at an angle of 45°. It carries a cork with a long condensing tube. At first the boiling goes on smoothly, but after a time violent bumping may supervene, endangering the flask but promoting the object in view. The contents of the flask are transferred to a beaker and diluted with distilled water to one and a half liters, shaken and allowed to settle for a time necessary to allow all particles of 0.25 millimeter hydraulic value to reach the bottom. The supernatant turbid liquid is decanted and the process repeated with smaller quantities of water until no further turbidity is produced. The united decantations, of which there will be from four to eight liters, are well shaken and a proper time allowed for the 0.25 millimeter hydraulic value sediments to fall. This last step is necessary to remove any such sediments which may have been carried over mechanically in the first separation. The dilution being very great, a fairly perfect separation is thus secured and the sediments are then ready for the elutriator. =226. Separation of Clay and Finest Silt.=—The property which pure clay possesses, of remaining suspended almost indefinitely in pure water, affords a ready means of separation from the silt particles of less than 0.25 millimeter hydraulic value. But the finest silt particles subside so slowly that this method of separation is too long to become practically applicable to secure a perfect demarcation between the finest silt and so-called colloidal clay. Hilgard recommends the following procedure: The clay water from the previous separation is placed in a cylindrical vessel of such a diameter as to allow the column of water to be 200 millimeters high where it is allowed to settle for twenty-four hours. When the clay is very abundant a longer time may be allowed; _viz._, from forty to sixty hours. The line of separation between the dark silt below and the translucent clay above is sharply defined. Finally the clay water is decanted and the remaining liquid poured off leaving the sediment as sharply defined as possible. The sediment is rubbed with a rubber pestle and a few drops of ammonia water added. Distilled water is added, the beaker well shaken or stirred to break up the floccules that may have formed and subsidence permitted as before. This operation is repeated from six to nine times until the water remains quite clear after subsidence or the decanted turbid water fails to be precipitated by brine showing the suspended matter to be fine silt and not clay. The diameter of the particles of silt thus obtained is from 0.001 to 0.02 millimeter, and it is impossible to obtain it quite free from any admixture with clay. =227. Estimation of the Colloidal Clay.=—The importance of the colloidal constituent of the clay is such as to make its direct determination desirable. The volume of the clay waters at this stage of the analysis may amount to twenty liters. One method of determination consists in evaporating an aliquot portion and this method will yield good results if the sample be free from soluble salts and the quantity taken be not too small. At least 500 cubic centimeters should be used for this purpose. A better method consists in precipitating the clay by means of a saline solution. A saturated solution of salt is recommended for this purpose of which fifty cubic centimeters are sufficient to precipitate the clay from one liter of the clay water. The precipitation is hastened by heating. Each portion of the clay water should be precipitated as soon as obtained, the total volume of the precipitate at the end of twenty-four hours is thus reduced to a minimum. The clay water from the succeeding separations of the same analysis can be mixed with the precipitate which diffuses therein, thus promoting the precipitation of the rest of the clay inasmuch as the separation takes place more readily where more clay is present. When all the clay is thus collected it can be gathered on a tared filter and washed with weak brine. Pure water may not be used because of the diffusibility of clay therein. After drying at 100° and weighing it is washed with a weak solution of ammonium chlorid until all sodium is removed. The filtrate is evaporated to dryness, ignited at low redness, and weighed. The weight of the sodium chlorid thus obtained plus the weight of the filter deducted from the total weight gives the weight of the clay precipitate. Whenever the clay collected as above will not diffuse in water it may be washed with water and its weight directly obtained. An excess of iron in clay will usually allow of the above treatment. =228. Properties of Pure Clay.=—The percentage of pure clay as obtained by the procedure described is about seventy-five in the finest natural clays, forty-five in heavy clay soils, and fifteen in ordinary loamy soils. When freshly precipitated by brine it is gelatinous resembling a mixed precipitate of iron and aluminum oxids. Its volume greatly contracts on drying, clinging tenaciously to the filter, from which it may be freed by moistening. On drying, it becomes hard, infriable, and often resonant. It usually possesses a dark brown tint due to iron oxid. Under the action of water it swells up like glue, the more slowly as the percentage of iron is greater. In the dry state it adheres to the tongue with great tenacity. According to Whitney the finest particles of colloidal clay have a diameter of 0.0001 millimeter. With a magnifying power of 350 diameters, however, Hilgard states that no particles can be discerned. =229. Chemical Nature of the Fine Clay.=—The fine particles separated as above consist essentially of hydrous aluminum silicate or kaolinite. It doubtless contains, however, other colloids or hydrogels whose absorptive powers are similar to those of clay. It appears also to contain sometimes free aluminum hydroxid, and colloidal ferric hydroxid, and amorphous zeolitic compounds. While the most careful mechanical separation can give at best only approximately the really plastic kaolinite substance, yet it is far closer than that attained by determination of total alumina with boiling sulfuric acid. By the latter treatment all the lime-kaolinite particles are decomposed and the method does not lead to even an approximate estimate of the soil’s plasticity. =230. Separation of the Fine Sediments.=—The sediments remaining after the separation of the clay and fine silt are ready for separation in the churn elutriator. The apparatus mounted, as already described, is brought into use by beginning with a low velocity of the water in the upright tube. The rate of flow should be set at from 0.25 millimeter to 0.50 millimeter per second, and the churn put in motion. When the elutriating tube is partly full of water the sediments should be poured in from a small beaker which is perfectly cleaned by means of a washing flask. The stopper and delivery tube of the elutriator are then put in place. The rate of flow should be so regulated that the sediments shall have had a few seconds of subsidence before the water is within thirty millimeters of the top. At this point the required velocity for the first sedimentation should be turned on; _viz._, 0.25 millimeter per second. At first the sediment passes off rapidly and the water in the elutriator is distinctly turbid. This excess of turbidity ceases in a few hours and then some attention is necessary in order to determine when the process is complete. In fact it never is completely finished, but where no more than one milligram of silt comes off with one liter of water it may be said to be practically done. The time required for the first operation varies from fifteen to ninety hours. Downward currents in the elutriator are likely to form in spite of all precautions, and floccules of silt adhere to its walls. These should be detached from time to time with a feather in order to bring them again in contact with the churn. Hilgard has found that, practically, 0.25 millimeter per second is about the lowest velocity available within reasonable limits of time, and that by successively doubling the velocities up to sixty-four millimeters a desirable ascending series of sediments is obtained; provided always, that a proper previous preparation has been given to the soil or clay. It would seem that according to the prescription given above for the preliminary sedimentation, no sediment corresponding to 0.25 millimeter velocity should remain with the coarser portion. That such is nevertheless always the case, often to a large percentage, emphasizes the difficulty, or rather impossibility, of entirely preventing or dissolving the coalescence of these fine grain sizes by hand stirring, as in beaker elutriation. It is only by such energetic motion as is above prescribed that this can be fully accomplished, and the delivery of 0.25 and 0.50 millimeter hydraulic value really exhausted. It is desirable to run off the upper third of the column at intervals of fifteen to twenty minutes by temporarily increasing the velocity. Recent sediments, river alluvium, etc., are more easily separated than soils of more ancient formation. The second, third, etc., separations are naturally accomplished in much less time than the first. The respective velocities of the separations should be 0.25 millimeter, 0.50 millimeter, one millimeter, two millimeters, four millimeters, eight millimeters, sixteen millimeters, thirty-two millimeters, and sixty-four millimeters a second. Below a velocity of four millimeters a second the mechanical stirrer is indispensable. Above this velocity the current of water in the conical base will be sufficient to bring the desired particles into the ascending column. At this velocity also a smaller elutriating tube having one-half or one-quarter the cross-section of the first may be employed to hasten the operation and diminish the quantity of water required. The quantity of water required for a complete separation is from 100 to 120 liters. Any soft water free of organic matter may be used, but distilled water is best. Hard water should be avoided. The mean time required for the different separations is as follows: 0.25 millimeter hydraulic value, thirty-five hours; 0.50 millimeter hydraulic value, twenty hours; one millimeter hydraulic value, seven and a half hours; two to sixty-four millimeters hydraulic value, eight hours. With proper arrangements for night work, an analysis may be finished in three or four days not counting the time required for the previous separation of the clay. =231. Weighing the Sediments.=—The sediments should be dried at the same temperature used for drying the soils. Hilgard dries both at 100°. Great care should be used in weighing the exceedingly hygroscopic clay sediments. In the case of the sediment of 0.25 millimeter hydraulic value it is allowed to subside as much as possible and after removing the supernatant water the residue, twenty-five to fifty cubic centimeters, is evaporated in a platinum dish and weighed therein. The water can be completely decanted from the other sediments, and they can be dried and weighed without any unusual precautions. The loss in the separation of clays and subsoils containing but little organic matter is usually from 1.5 to 2 per cent. This loss is partly due to the fine silt which comes off during the whole of the process and which is lost in the decanted waters of the sediments of 0.25 millimeters hydraulic value and above. The procedures indicated above are not strictly applicable to soils rich in humus and other organic matters, but the destruction of these matters by ignition leaves the residual soil in a condition wholly unfit for sedimentary separation. =232. Classification of Results.=—A convenient method of stating the results of an analysis may be seen from the following classification. The percentage obtained for each of the classes is to be entered in the column provided for that purpose. No. Names of Silt Diameter of Velocity of Classes. grains in current Per millimeters. millimeters cent. hydraulic value. Sieves. 1. Grits 1 –3 2.07 „ 2. Fine grits 0.5–1 „ ─────────────────────────────────────────────────────────────────────── Elutriator 3. Coarse sand 0.50 64 0.55 without churn. „ 4. Medium sand 0.30 32 „ „ 5. Fine sand 0.16 16 „ ─────────────────────────────────────────────────────────────────────── Elutriator 6. Finest sand 0.12 8 0.21 with churn. „ 7. Coarse silt 0.072 4 1.21 „ 8. Large silt 0.047 2 2.92 „ 9. Medium silt 0.036 1 7.36 „ 10. Silt 0.025 0.5 8.86 „ 11. Fine silt separated 0.016 0.25 7.85 in elutriator ─────────────────────────────────────────────────────────────────────── Beaker 12. Fine silt separated 0.010 <0.25 35.22 sedimentation. from clay water „ 13. Clay 0.0001 <0.0023 33.16 ————— Total 99.36 The measurements of diameters in the above table is of the best formed quartz grains in each class. Naturally the actual size of the particles may vary in each class within the extreme limits of the diameter next above and below. It is not easy to indicate in popular language distinctions not popularly made but the grades of particles designated by the names grits, sand and silt, may serve, at least, to establish uniformity of expression. The term grits is thus applied to all grains above one millimeter in diameter up to gravel. Below one millimeter down to 0.1 millimeter may be called sand and below that silt may designate the particles down to an impalpable powder. =233. Influence of Size of Tube.=—The diameter of the elutriating tube exerts a sensible influence on the character of the sediments. The friction against the sides of a small tube is comparatively greater than in a large tube. Strictly speaking, no class of sediments strictly corresponds to the hydraulic value calculated from the cross section of the tube and the quantity of water supplied thereto. The sediments correspond actually to higher velocities, due to the fact that the lateral friction causes a more rapid flow in the center of the water column. This may be demonstrated by slightly diminishing the velocity while a sediment is copiously discharging. The turbid column then remains stationary while clear water is running off. =234. Statement of Results.=—A complete silt analysis of a soil, conducted by the method of Hilgard, depends largely for its practical value on an intelligible tabulation. The method of collating results is illustrated in the table of analyses of Mississippi soils shown on page 237. The character of the soils entering into the given analyses is as follows: Nos. 248, 206, 209, 397, 219, belong to the end of the drift period. No. 230 is one of the two chief varieties of soils occurring in what is known as the flat-woods, a level surface bordering on the cretaceous area, having lower tertiary clays near the surface. No. 165 is a light soil which occurs in the former in irregular strips and patches, is easily tilled, absorbs rain water readily, but is subject to drought and does not hold manure. SILT ANALYSES OF MISSISSIPPI SOILS AND SUBSOILS. ──┬─────────────┬────────────┬───────────┬────────── │ Designation │ Diameter. │ Velocity │ DRIFT │of Materials.│Millimeters.│(Hydraulic │ │ │ │ value). │ │ │ │Millimeters│ │ │ │per second.│ ──┼─────────────┼────────────┼───────────┼────────── │ „ │ „ │ „ │ „ ──┼─────────────┼────────────┼───────────┼────────── │ „ │ „ │ „ │ „ ──┼─────────────┼────────────┼───────────┼────────── │ „ │ „ │ „ │ 238 │ │ │ │ White │ │ │ │pipeclay. │ │ │ │Tishomingo │ │ │ │ Co. │ │ │ │ ──┼─────────────┼────────────┼───────────┼────────── 1│Coarse grits │ 1.0 to 3.0│ │ 2│Fine „ │ 0.5 to 1.0│ │ 3│Coarse sand │ 0.40│ 6│ 0.06 4│Medium „ │ 0.30│ 32│ „ 5│Fine „ │ 0.16│ 16│ „ 6│Finest „ │ 0.12│ 8│ 0.08 7│Dust „ │ 0.072│ 4│ 0.02 8│Coarsest silt│ 0.047│ 2│ 0.04 9│Coarse „ │ 0.036│ 1│ 0.08 10│Medium „ │ 0.025│ 0.5│ 0.08 11│Fine „ │ 0.015│ 0.25│ 2.00 12│Finest „ │ 0.008│ <0.25│ 21.15 13│Clay │ 0.0001│ <0.0023│ 74.65 ──┴─────────────┴────────────┴───────────┼────────── │ 98.16 Compactness (resistance to tillage) │ 97.80 Porosity │ 0.36 Hygroscopic Moisture (+7° to +21°) │ 9.09 Ferric Oxide │ 0.13 ─────────────────────────────────────────┴────────── ──┬─────────────┬───────────────────────────────────────────────────── │ Designation │ UPLAND. │of Materials.│ │ │ │ │ │ │ ──┼─────────────┼───────────────────────────────────────────────────── │ „ │ YELLOW LOAM. ──┼─────────────┼─────────────────────────┬─────────────────────────── │ „ │ SANDY. │ LOAM. ──┼─────────────┼─────────┬─────────┬─────┼────────┬─────────┬──────── │ „ │ 248 │ 165 │ 206 │ 209 │ 397 │ 219 │ │Tallahoma│ Lt. │Pine │ Pine │ Oxford │ Table │ │ subsoil │Flatwoods│Hill │ Hill │subsoil. │ Land │ │ Jasper │ soil. │soil.│subsoil.│Lafayette│subsoil. │ │ Co. │Chickasaw│Smith│ Smith │ Co. │ Benton │ │ │ Co. │ Co. │ Co. │ │ Co. ──┼─────────────┼─────────┼─────────┼─────┼────────┼─────────┼──────── 1│Coarse grits │ 6.94│ 2.90│ 0.36│ 0.36│ │ 0.23 2│Fine „ │ 17.65│ 6.96│ 2.98│ 0.83│ │ „ 3│Coarse sand │ 18.81│ 2.81│ 6.62│ 6.21│ 0.79│ 1.47 4│Medium „ │ 10.16│ 4.41│ 7.75│ 3.38│ „ │ 2.33 5│Fine „ │ 2.66│ 3.13│ 3.01│ 3.85│ „ │ 1.17 6│Finest „ │ 1.66│ 2.02│ 1.59│ 1.49│ 0.18│ 0.78 7│Dust „ │ 1.02│ 2.23│ 1.19│ 0.64│ 0.78│ 0.76 8│Coarsest silt│ 0.88│ 5.06│ 3.56│ 2.63│ 3.56│ 9.79 9│Coarse „ │ 1.96│ 9.67│ 6.50│ 5.40│ 13.12│ 7.26 10│Medium „ │ 7.89│ 14.18│13.97│ 7.77│ 16.64│ 13.14 11│Fine „ │ 8.40│ 22.03│14.20│ 16.65│ 27.28│ 15.07 12│Finest „ │ 15.53│ 15.62│29.36│ 37.75│ 18.87│ 26.50 13│Clay │ 8.63│ 7.86│ 4.58│ 10.70│ 17.23│ 19.19 ──┴─────────────┼─────────┼─────────┼─────┼────────┼─────────┼──────── │ 99.28│ 98.68│95.67│ 97.77│ 98.35│ 97.65 Compactness (res│ 32.56│ 45.33│48.14│ 45.10│ 63.38│ 60.82 Porosity │ 59.55│ 40.40│37.89│ 47.13│ 20.23│ 26.04 Hygroscopic Mois│ 1.80│ 3.36│ 2.48│ 7.69│ 8.79│ 7.21 Ferric Oxide │ 1.10│ 1.45[G]│ 1.25│ 4.15│ 2.53│ 5.11 ────────────────┴─────────┴─────────┴─────┴────────┴─────────┴──────── ──┬─────────────┬──────────────────────────────────── │ Designation │ UPLAND. │of Materials.│ │ │ │ │ │ │ ──┼─────────────┼────────┬─────────────────────────── │ „ │ YELLOW │ TERTIARY. │ │ LOAM. │ ──┼─────────────┼────────┴─────────────────────────── │ „ │ CLAY. ──┼─────────────┼────────┬─────────┬────────┬──────── │ „ │ 173 │ 230 │ 246 │ 196 │ │Prairie │ High │ Red │ Hog │ │subsoil.│Flatwoods│ Hills │ Wallow │ │ Monroe │ soil. │subsoil.│subsoil. │ │ Co. │Pontotoc │ Attala │ Jasper │ │ │ Co. │ Co. │ Co. ──┼─────────────┼────────┼─────────┼────────┼──────── 1│Coarse grits │ 2.10│ 0.33│ 1.97│ 0.83 2│Fine „ │ „ │ 0.35│ „ │ 1.19 3│Coarse sand │ 0.62│ │ 0.72│ 1.96 4│Medium „ │ „ │ │ 2.32│ 1.64 5│Fine „ │ „ │ │ 2.09│ 0.88 6│Finest „ │ 0.20│ 0.23│ 0.70│ 0.26 7│Dust „ │ 1.26│ 0.18│ 1.29│ 0.19 8│Coarsest silt│ 2.92│ 1.61│ 1.81│ 2.49 9│Coarse „ │ 7.36│ 2.66│ 3.60│ 3.67 10│Medium „ │ 8.81│ 9.13│ 2.73│ 5.39 11│Fine „ │ 7.85│ 26.64│ 13.30│ 10.31 12│Finest „ │ 35.22│ 32.35│ 25.33│ 24.18 13│Clay │ 33.16│ 25.48│ 40.25│ 47.03 ──┴─────────────┼────────┼─────────┼────────┼──────── │ 99.50│ 97.87│ 96.11│ 100.00 Compactness (res│ 69.77│ 84.47│ 78.88│ 81.52 Porosity │ 17.04│ 6.40│ 39.18│ 10.12 Hygroscopic Mois│ 11.35│ 9.33│ 18.60│ 14.48 Ferric Oxide │ 5.42│ 5.90[G]│ 10.50│ 4.00 ────────────────┴────────┴─────────┴────────┴──────── ──┬─────────────┬──────────────────────────────────────────────────────────────────────── │ Designation │ MISSISSIPPI BOTTOM. │of Materials.│ │ │ │ │ │ │ ──┼─────────────┼───────────────────┬──────────────────────────────────────────────────── │ „ │ Champlain. │ MODERN. ──┼─────────────┼───────────────────┼──────────────────────────────┬───────────────────── │ „ │ Swamp River. │ RIVER DEPOSIT. │ DELTA. ──┼─────────────┼─────────┬─────────┼────────────┬─────────┬───────┼──────────┬────────── │ „ │ 390 │ 237 │ 365 │ 377 │ 395 │ Southwest│ Southwest │ │Buckshot │ Loess. │Tallahatchie│Frontland│Dogwood│ Pass.│ mudlump. │ │ soil. │Claiborne│soil. Panola│subsoil. │ ridge │Plaquemine│Plaquemine │ │Issaquena│ Co. │ Co. │Sunflower│ soil. │ Par.│ Par. │ │ Co. │ │ │ Co. │Coahoma│ │ │ │ │ │ │ │ Co. │ │ ──┼─────────────┼─────────┼─────────┼────────────┼─────────┼───────┼──────────┼────────── 1│Coarse grits │ 0.09│ 0.24│ 0.09│ │ │ │ 2│Fine „ │ 0.05│ „ │ „ │ │ │ │ 3│Coarse sand │ │ 0.37│ 0.04│ 0.32│ 0.15│ 0.18│ 0.10 4│Medium „ │ 0.36│ 0.61│ 0.05│ „ │ │ „ │ „ 5│Fine „ │ │ 0.93│ 0.21│ 2.97│ │ 0.47│ 5.02 6│Finest „ │ 0.31│ 1.65│ 1.30│ 2.41│ 3.74│ 7.03│ 3.68 7│Dust „ │ 0.27│ 1.95│ 2.68│ 16.90│ 21.49│ 12.38│ 5.34 8│Coarsest silt│ 1.56│ 14.25│ 9.38│ 19.79│ 21.83│ 13.27│ 10.09 9│Coarse „ │ 2.23│ 16.20│ 9.88│ 13.90│ 14.01│ 15.87│ 5.58 10│Medium „ │ 3.68│ 20.08│ 20.37│ 4.27│ 9.93│ 8.25│ 9.54 11│Fine „ │ 8.97│ 5.59│ 19.79│ 1.89│ 9.58│ 7.26│ 8.01 12│Finest „ │ 38.19│ 33.38│ 25.30│ 30.08│ 8.65│ 19.67│ 34.46 13│Clay │ 44.30│ 2.51│ 9.64│ 5.51│ 10.35│ 12.20│ 18.18 ──┴─────────────┼─────────┼─────────┼────────────┼─────────┼───────┼──────────┼────────── │ 100.01│ 97.74│ 98.73│ 98.04│ 99.72│ 96.58│ 100.00 Compactness (res│ 89.46│ 41.48│ 54.63│ 37.48│ 28.57│ 39.13│ 60.65 Porosity │ 4.87│ 38.44│ 23.63│ 58.25│ 61.50│ 49.20│ 28.81 Hygroscopic Mois│ 14.31│ 4.18│ 6.12│ 5.68│ 3.95│ │ Ferric Oxide │ 5.82[G]│ 3.27│ 2.58│ 2.31│ 2.69│ │ ────────────────┴─────────┴─────────┴────────────┴─────────┴───────┴──────────┴────────── Footnote G: Bog ore. No. 248 is from a soil stratum three feet thick. The soil is so light that the finer particles of it are carried away by high winds. Nos. 206 and 209 are typical of the soils producing the long-leaf pine. This soil is much improved by an admixture of the subsoil No. 209, which enables it to hold manure. No. 219 is a cotton upland soil of the best quality, found in Western Mississippi and Tennessee. No. 397 is the same soil of a second rate quality. These lands are easily washed into gullies on account of their lack of perviousness to water. They also easily swell up in contact with water, and become thereby readily diffused. The denudations produced by heavy rains are rapidly destroying the lands covered by these soils. No. 173 is a sedimentary or residual subsoil of the cretaceous prairies of Northeastern Mississippi, forming a stratum from three to seven feet thick. No. 230 is a residual soil which is formed by the disintegration of the old tertiary clays. It yields good crops only in very favorable years, and is easily injured both by wet and dry seasons. No. 246 is a soil of the same origin, but is more easily tilled than the foregoing, does not crack, but becomes very hard when dried slowly. Its superiority to the former soil as regards tillage consists in the presence of the large amount of iron and lime. No. 196 is a typical heavy clay soil; is better suited for the potter than the farmer. It cracks on drying, whence its popular name. On the accession of rain the edges of these cracks crumble and fall, until finally the lumpy surface is produced which is locally known as hog wallows. No. 390, the richest soil of the Yazoo Bottom, seems to have a physical composition like the preceding one. Its superiority is due not only to the increased quantity of plant food which it contains, but to its property of crumbling on rapid drying. Even when plowed wet, on drying each clod crumbles into a loose pile resembling buck-shot; whence its name. It is strongly calcareous. As comparative data, are added the soils 365, 377, and 395, representing alluvial deposits, and two deposits from the Delta of the Mississippi. =235. Comparison of Osborne’s Method with Hilgard’s Method.=[154]—The comparative results obtained by Osborne’s method, beaker elutriation, and Hilgard’s method, churn elutriation, are given in the following tables: SOIL FROM EXPERIMENT STATION GARDEN, NEW HAVEN, CONN. SURFACE SOIL, BOILED TWENTY-THREE HOURS. Beaker elutriation. Average of four Churn elutriation. analyses. Diameter in millimeters. per cent. per cent. per cent. Removed by sieves 47.77 47.77 47.77 0.25–0.05 22.06 21.95 20.75 0.05–0.01 11.20 11.62 11.18 <0.01 9.82 9.14 10.72 Clay (difference) 2.32 2.69 2.75 Loss on ignition 6.83 6.83 6.83 —————— —————— —————— 100.00 100.00 100.00 SUBSOIL, BOILED TWENTY-THREE HOURS. Churn elutriation. Beaker elutriation. Diameter in millimeters. per cent. per cent. per cent. per cent. Removed by sieve 39.33 39.33 39.33 39.33 0.25–0.05 33.61 30.83 32.35 32.95 0.05–0.01 10.91 12.25 10.32 10.37 <0.01 7.05 8.11 8.29 7.64 Clay 5.02 5.40 5.63 5.63 Loss on ignition 4.08 4.08 4.08 4.08 —————— —————— —————— —————— 100.00 100.00 100.00 100.00 These analyses agree quite as well as could be expected from two such different methods. _Elutriation of Clayey Soils._—Hilgard found that by churn elutriation no satisfactory results could be obtained on clay without long boiling and subsequent kneading of the finer sediments. Osborne examined a sample of clay by his method after previous boiling for twenty-three hours. When the sediments were examined by the microscope they were found to contain many aggregations of particles which broke into dust under the pressure of the thin glass slide-cover. These sediments were then gently crushed in the beaker with the help of a soft rubber stopper with a glass rod for a handle, the grinding together of the particles being, as much as possible, avoided. This pestling was continued with clear water as long as it occasioned turbidity. Comparison of the analyses shows that practically identical results were obtained on this soil whether it was boiled or not and indicates that the sediments are reduced to their elements by gentle pestling alone. For such soils, therefore, it is demonstrated that pestling is a much safer treatment than boiling. The same remark may be applied to the fertile prairie soil of Mercer County, Illinois, where boiling proved quite insufficient and in which the pestling process proved completely successful. The general conclusions arrived at from the results obtained by Osborne are as follows: 1. On sands and silts of pure quartz or similar resistant material Hilgard’s method and beaker elutriation give practically identical results. 2. With coarse sands and silts upon whose grains finer matter has been cemented by silicates, etc., and with soils containing soft slaty detritus, the churn elutriator with preliminary boiling may give results too low for the coarse and too high for the finer grades. In these cases beaker elutriation with pestling yields more correct figures. 3. Some loamy soils containing no large amount of clay or of extremely fine silt, as well as prairie soils rich in humus, cannot be suitably disintegrated by twenty-four hours’ boiling, but are readily reduced by pestling. 4. Beaker elutriation preceded by sifting, gives results in five or six hours with use of two to three gallons of pure water, which, in churn elutriation, require several days and consume eight to ten gallons of pure water. 5. Hilgard found that practically 0.25 millimeter is about the lowest velocity of water current per second available within reasonable limits of time in his elutriator. Such a current carries over particles up to 0.015 millimeter diameter and hence the silts of less dimensions cannot be conveniently separated by churn elutriation. In beaker elutriation there is no difficulty in making good separations at 0.01 millimeter and at 0.005 millimeter. 6. Beaker elutriation requires no tedious boiling or preliminary treatment and with careful pestling of the sediments gives, we believe, as nearly as possible, a good separation of adhering particles and at every stage of the process carries with it, in the constant use of the microscope, the means of testing the accuracy of its work and of observing every visible peculiarity of the soil. It is not claimed that pestling may not easily go too far, but in any case a good judgment may be formed of its effects and of the extent to which it is desirable to carry it. 7. In beaker elutriation the flocculation of particles occasions little inconvenience and does not impair the accuracy of the results. =236. Comparison of the Osborne with the Schloesing Method.=—Schloesing’s method has been compared by Osborne[155] with the beaker method of elutriation with the following results: SCHLOESING’S METHOD. Per cent. Calcium carbonate 4.20 Sand 64.91 Clay 22.65 Humus none Loss on ignition 6.60 BY THE DIRECT BEAKER METHOD. Per cent. Above 0.25 millimeter diameter 1.02 0.25–0.05 millimeter diameter 0.76 0.05–0.01 millimeter diameter 20.95 Below 0.01 millimeter diameter 71.01 Loss on ignition 6.60 It is seen by the above that there is little agreement between the results of the two methods. With the prairie soil from Mercer County, Ill., the following results were obtained working on the original sample and the sand separated by the Schloesing process: SCHLOESING’S METHOD. Per cent. Calcium carbonate 0.88 Humus 1.57 Loss at 150° C. 4.42 Sand 82.86 Clay 7.86 ————— 97.59 BEAKER METHOD. Original Schloesing’s sand. soil. Dried at 150°C., Ignited, Ignited, per cent. per cent. per cent. Above 0.25 millimeter diameter 0.12 0.10 0.92 0.25–0.05 millimeter diameter 3.58 3.55 2.89 0.05–0.01 millimeter diameter 42.69 41.87 42.86 0.01–0 millimeter diameter 23.66 20.47 } 31.44 Clay 12.81 10.14 } Clay 7.40 Loss on ignition 6.73 14.49 ————— ————— —————— 82.86 82.86 100.00 Osborne says the above figures indicate that the treatment with acid has disintegrated the particles of less than 0.01 millimeter diameter so that one-third of this portion appears as clay, according to the Hilgard method of estimating clay, which is the one employed. As to the humus it may be noted that loss in the analysis by Schloesing’s method; _viz._, 2.41 per cent, plus loss at 150° = 4.42 per cent, plus humus found = 1.57 per cent, plus carbon dioxid (⁴⁴⁄₅₆ of 0.88 =) 0.69 per cent amounts to 9.09 per cent, while the loss on ignition which represents humus, carbon dioxid and water is 14.49 Per cent. The 5.40 per cent difference must evidently be, for the most part, humus which has escaped estimation by the Schloesing method, having been distributed among the sand and clay. =237. The Mechanical Determination of Clay.=—Schloesing’s method for the separation of the clay as stated by Osborne[156] is essentially one of subsidence for twenty hours from a volume of from 200 to 250 cubic centimeters of water, but of no specified height. Hilgard’s conventional method requires the same time and a height of solution of 200 millimeters. Such methods of separation assume, first, that most of the sand and, second, that little of the clay shall settle within the fixed time. That both of these assumptions are fallacious, the following experiments show. The clay obtained by twenty hours subsidence from thirty grams of brick clay is suspended in four liters of distilled water and allowed to settle out completely, which requires several days. The water is then decanted so as to remove all soluble matters, the jar again filled with distilled water, and the clay and fine sand allowed to settle again for several days. The upper three-quarters of the liquid are then decanted and made up to a volume of four liters, and this is allowed to stand several days, when a considerable sediment forms. A decantation is again made as before. The operations are repeated until the clay water has been so far freed from the clay as to become opalescent; then it first ceases to deposit any appreciable sediment. A microscopic examination of the several sediments thus collected shows them all to contain particles of sand. It appears, therefore, that only after the liquid containing the clay has become opalescent does it cease to deposit fine particles of sand as well as of clay. Furthermore, the character of the true clay itself is so changed under certain conditions that it loses the property of remaining in prolonged suspension in water. A sample of clay which has been freed from particles of sand exceeding 0.005 millimeter diameter is suspended in water and precipitated from it by freezing. It is then washed by decantation with alcohol and dried in the air. A portion of this clay is shaken with water and allowed to stand a few hours, during which time the greater part of it has settled. After decanting the water and suspended clay and repeating this process a few times, a very considerable part of the clay is left which will subside completely through 100 millimeters in a few hours. After standing under water for several months, only a small part of the clay has regained the quality of prolonged suspension. It has been found, however, that if this clay be pestled, this quality of prolonged suspension is restored to it to a very considerable degree. It is evident, therefore, that conventional methods depending on simple subsidence can give no accurate results because the ever varying amounts of finest sand and clay in different soils yield variable mixtures of the two when subjected to any simple course of treatment by elutriation and subsidence. The method of persistent pestling and repeated subsidences and decantations continued until no further separation can be effected, although extremely tedious, is the only one which has so far yielded even approximately good separations on any of the clayey soils examined by Osborne. A single subsidence of the clay water for twenty-four hours will free it from all particles of sand having a diameter greater than 0.005 millimeter, but in many cases a considerable amount of finer sand will remain in suspension for many hours or days. On the other hand, the sediment formed during the twenty-four hours subsidence will not be free from clay, as may be easily seen by suspending it in water a second time and allowing it to stand again for twenty-four hours. Both Hilgard and Schloesing direct attention to these defects, but assume that they do not usually influence the results to a sufficient extent to deprive them of value. In many cases this is undoubtedly true, as, for example, in such soils as that from the garden of the Experiment Station, at New Haven, in which there is but little clay and fine sand; but in soils of the opposite character, as in the North Haven brick clay where exact separations are most desirable, a very considerable error is thus inevitably encountered. =238. Effect of Boiling on the Texture of Clayey Soils.=—Most investigators who have worked upon mechanical soil analysis advise boiling with water in order to detach clay and sand from each other and make a good separation of the several mechanical elements practicable or possible. In general, however, the instructions as to the time and manner of boiling are rather indefinite, and no definite research as to the effects of this treatment has been undertaken. The practice of Hilgard, to boil twenty-four hours or even longer in case of adhesive clays, according to Osborne[157] appears to be objectionable in view of the dehydration and change of physical properties known to occur in case of many hydroxids, especially those of iron and aluminum, which may be present in the soil. It is a familiar fact that the hydroxids above named and many other amorphous substances when precipitated from cold solutions are more bulky and less easily washed upon a filter than when thrown down hot. It is also well known that their properties are considerably changed by warming or boiling with water. Heating with water to boiling for some hours or days gradually converts the bulky brown-red ferric hydroxid, which when precipitated cold and air-dried for eighteen days, contains thirty-eight per cent of water, into a much denser, bright red substance containing but two per cent of water. St. Gilles has also observed the partial dehydration of aluminum hydroxid from Al₂O₃.5H₂O to Al₂O₃.2H₂O by prolonged boiling. The hydrate of silica and the highly hydrated silicates are most probably affected in a similar manner, and if such be the case, boiling would evidently change the constitution of clay in a very essential degree. The following experiments throw light on this subject: Ten grams of North Haven brick clay were boiled continuously for nine days with about 700 cubic centimeters of distilled water, in a glass flask of one liter capacity and furnished with a reflux condenser. Fifteen grams were boiled in the same manner for eight and one-half days. When the boiling was concluded, the soil was found to have assumed a granular condition, the clay and fine sand being collected into a mass of small grains resembling coarse sand and settling rapidly. One portion thus boiled was elutriated by the beaker method, the other by Hilgard’s. The pestle was not used on either of those portions as it was desired to determine simply the effect of prolonged boiling. The separations thus accomplished are here compared with the elutriations of the same soil boiled twenty-three hours and of the pestled but unboiled soil. Hilgard elutriation. Beaker elutriation. Not pestled. Not pestled. Not Pestled. Pestled. Boiled Boiled eight twenty-three Boiled nine and a half hours, days, days. Not boiled. Diameter of particles. per cent. per cent. per cent. per cent. By sieves 3.36 3.24 3.63 3.49 0.25–0.05 1.21 1.11 1.91 1.29 0.05–0.01 28.27 33.04 33.61 27.02 0.01–0 56.29 48.85 54.78 52.21 Clay 4.92 3.05 1.97 10.15 Loss on ignition 5.95 5.95 5.95 5.95 —————— —————— —————— —————— 100.00 95.24 101.85 100.11 Here it is observed that the eight to nine days boiling diminished the clay as determined by Hilgard’s conventional method by seven to eight per cent, increasing the dust by two to three per cent, and the silt by about six per cent. Under the microscope small, rounded, opaque, brown granules were seen in large numbers, which when pressed under the cover glass, broke up into a multitude of very fine particles. From these experiments it would appear to be conclusively proved that too long boiling precipitates clay and thereby defeats the very object of the operation. In these experiments the time of boiling was prolonged in order to bring out unmistakably the effects of this operation. If ebullition for eight or nine days reduces clay from ten to two per cent, increasing the 0.05–0.01 millimeter diameter grades by six per cent, it is evident that boiling for one day or a shorter time becomes a questionable treatment. Further experiments[158] made by boiling clay in a platinum vessel with a platinum condenser showed that this precipitation of the clay was largely if not wholly due to the salts extracted from the soil. When the clay has once been converted into the granular condition, considerable difficulty is experienced in restoring it to the state in which it is capable of prolonged suspension in water. The results of the studies herewith reported may be summed up as follows: 1. The Berlin-Schöne method of elutriation gives fairly correct separations with sandy soils containing little clay or matters finer than 0.01 millimeter diameter, but on soils of fine texture, as loams rich in humus and clays, it gives results which are grossly inaccurate, the error on single grades amounting to from eight to fourteen per cent. 2. In respect of rapidity, economy of time, and ease of operation, the Schöne elutriation has no advantage over the beaker method. 3. Schloesing’s method on its mechanical side makes no satisfactory separations, and the chemical treatment it employs is liable to alter seriously the texture of the soil. 4. The determination of clay from a single subsidence from any conventional depth or volume of water, or for any conventional time, is not a process certain to effect even a roughly approximate separation of the finest quartz grains from true clay. 5. Boiling with water must be rejected as a treatment preliminary to mechanical analysis, because it not only abrades and reduces the coarser sediments, but may dehydrate and coagulate the true clay and thus alter essentially the texture and grain of the soil. =239. General Conclusions.=—The methods of Hilgard and Osborne have been given in detail and largely in the descriptive language used by the authors. The other methods of elutriation in use in other countries have also been described. For practical use the methods of Hilgard and Osborne are to be preferred to all others. For simplicity and speed the Osborne method has the preference over the Hilgard. For rigid control of the work the Hilgard method is to be preferred. The effect of long boiling on clay pointed out by Osborne would suggest that the boiling process preliminary to the Hilgard method be made as short as possible. It would seem that the churn attrition in the Hilgard method might well be regarded as a substitute for the soft pestling of the Osborne process, and any prolonged boiling in the former method might be safely omitted. When carefully carried out, the results of the Hilgard and Osborne method are fairly comparable. =240. Distribution of Soil Ingredients.=—The determination of the distribution of the soil ingredients in the sediments obtained in silt analysis is illustrated by the following table:[159] ────────────╥────────────╥───────────╥────────────╥──────────── Hydraulic ║ ║ ║ ║ value ║ Clay ║ <0.25mm ║ 0.25mm. ║ 0.5mm. Per cent in ║ ║ ║ ║ soil ║ 21.64 ║ 23.56 ║ 12.54 ║ 13.67 ════════════╬══════╤═════╬═════╤═════╬══════╤═════╬══════╤═════ ║ │ ║ │ ║ │ ║ │ ║ =A= │ =B= ║ =A= │ =B= ║ =A= │ =B= ║ =A= │ =B= ║ │ ║ │ ║ │ ║ │ Insoluble ║ │ ║ │ ║ │ ║ │ residue ║ 15.96│ 4.35║73.17│17.29║ 87.96│11.03║ 94.13│12.72 Soluble ║ │ ║ │ ║ │ ║ │ silica ║ 33.10│ 7.17║ 9.95│ 2.34║ 4.27│ 0.53║ 2.35│ 0.32 Potash ║ 1.47│ 0.32║ 0.53│ 0.12║ 0.29│ 0.04║ 0.12│ 0.01 Soda ║(1.70)│ ║ 0.24│ 0.06║ 0.28│ 0.04║ 0.21│ 0.02 Lime ║ 0.09│ 0.03║ 0.13│ 0.03║ 0.18│ 0.02║ 0.09│ 0.01 Magnesia ║ 1.33│ 0.29║ 0.46│ 0.11║ 0.26│ 0.03║ 0.10│ 0.01 Manganese ║ 0.30│ 0.06║ 0.00│ 0.00║ 0.00│ 0.00║ 0.00│ 0.00 Ferric oxid ║ 18.76│ 4.06║ 4.76│ 1.11║ 2.34│ 0.29║ 1.03│ 0.14 Alumina ║ 18.19│ 3.97║ 4.32│ 1.04║ 2.64│ 0.33║ 1.21│ 0.17 Phosphoric ║ │ ║ │ ║ │ ║ │ acid ║ 0.18│ 0.04║ 0.11│ 0.02║ 0.03│ 0.00║ 0.02│ 0.00 Sulfuric ║ │ ║ │ ║ │ ║ │ acid ║ 0.06│ 0.01║ 0.02│ 0.01║ 0.03│ 0.00║ 0.03│ 0.00 Volatile ║ │ ║ │ ║ │ ║ │ matter ║ 9.00│ 1.33║ 5.61│ 1.43║ 1.72│ 0.23║ 0.92│ 0.29 ────────────╫──────┼─────╫─────┼─────╫──────┼─────╫──────┼───── Total ║100.14│21.64║99.30│23.56║100.00│12.54║100.21│13.67 Total ║ │ ║ │ ║ │ ║ │ soluble ║ │ ║ │ ║ │ ║ │ matter. ║ 75.18│ ║20.52│ ║ 10.32│ ║ 5.16│ „ „ ║ │ ║ │ ║ │ ║ │ bases ║ 41.84│ ║10.44│ ║ 5.99│ ║ 2.76│ Soluble ║ │ ║ │ ║ │ ║ │ silica in ║ │ ║ │ ║ │ ║ │ crude ║ │ ║ │ ║ │ ║ │ substance.║ 0.38│ 0.01║ │ ║ │ ║ │ ────────────╨──────┴─────╨─────┴─────╨──────┴─────╨──────┴───── ────────────╥───────────╥──────────┬──────────┬──────── Hydraulic ║ ║ │ │ value ║ 1.0mm. ║ │ │ Per cent in ║ ║ Other │ Total │Original soil ║ 13.11 ║sediments.│sediments.│ soil. ════════════╬═════╤═════╬══════════╪══════════╪════════ ║ │ ║ │ │ ║ =A= │ =B= ║ │ │ ║ │ ║ │ │ Insoluble ║ │ ║ │ │ residue ║96.52│12.74║ 13.76│ 71.89│ 70.53 Soluble ║ │ ║ │ │ silica ║ │ 0.36║ │ 10.36│ 12.30 Potash ║ │ „ ║ │ 0.49│ 0.63 Soda ║ │ „ ║ │ 0.12│ 0.09 Lime ║ │ „ ║ │ 0.09│ 0.27 Magnesia ║ │ „ ║ │ 0.44│ 0.45 Manganese ║ │ „ ║ │ 0.06│ 0.06 Ferric oxid ║ │ „ ║ │ 5.60│ 5.11 Alumina ║ │ „ ║ │ 5.51│ 8.09 Phosphoric ║ │ ║ │ │ acid ║ │ „ ║ │ 0.06│ 0.21 Sulfuric ║ │ ║ │ │ acid ║ │ „ ║ │ 0.02│ 0.02 Volatile ║ │ ║ │ │ matter ║ │ „ ║ │ 3.64│ 3.14 ────────────╫─────┼─────╫──────────┼──────────┼──────── Total ║ │13.10║ │ 98.28│ 100.63 Total ║ │ ║ │ │ soluble ║ │ ║ │ │ matter. ║ │ ║ │ │ „ „ ║ │ ║ │ │ bases ║ │ ║ │ │ Soluble ║ │ ║ │ │ silica in ║ │ ║ │ │ crude ║ │ ║ │ │ substance.║ │ ║ │ │ 0.19 ────────────╨─────┴─────╨──────────┴──────────┴──────── =A.= Calculated on the amount of sediment. =B.= Calculated on the amount of soil. It is seen from the above analyses that the clay is by far the richest in mineral constituents, of all the ingredients separated in silt analysis, the amount in the clay being more than twice that of all the others combined. Its volatile matter is also the largest. The large amount of soda, however, is probably in part due to the sodium chlorid used in the precipitation of the diffused clay. The following points in regard to the distribution of the different ingredients are instructive: 1. The iron and alumina exist in almost identical relative proportions in each sediment, making it probable that they are in some way definitely correlated. 2. Potash and magnesia also exist in almost the same quantities, and their ratio to each other in all the sediments being almost constant seems to indicate that they occur combined, perhaps in some zeolitic silicate which may be a source of supply to plants. 3. Manganese exists only in the clay, a mere trace being found in the next sediment. 4. The lime appears to have disappeared in the clay, having probably been largely dissolved in the form of carbonate by the large quantity of water used in elutriation. Its increase in the coarser portions may be owing to its existence in a crystallized form not so readily soluble. 5. In a summary of the ingredients, it is seen that there is a loss in potash, magnesia and lime in the sediments as compared with the original soil; and this loss is doubtless due to the solution of these bodies in the water of elutriation. A noteworthy fact shown in this table is the rapid decrease of acid-soluble matter in the coarser sediments; even what is dissolved from so fine a sediment as 1.0 millimeter hydraulic value, equal to a diameter of 0.04 millimeter, is in this case a negligible quantity. This suggests forcibly the inutility of introducing into chemical soil analysis, grains of as large a size as will pass a sieve of one millimeter aperture. The hydraulic value of these grains would be somewhere between 150 and 200 millimeters per second. While the exact results of the above analysis may not be applicable to all soils, yet the range is so wide that the systematic exclusion from chemical analysis of inert material, by means of preliminary mechanical separation, seems likely to lead to important improvements in the interpretation of the results. =241. Percentage of Silt Classes in Different Soils.=—The adaptation of a soil to different crops depends largely on the sizes of the particles composing it and consequently on the relative percentages of the silt classes. The following table gives the mechanical analysis of some markedly different types of subsoils:[160] Diameter, Conventional Truck millimeters. names. and Grass Early small and truck. fruit. Tobacco. Wheat. wheat. Limestone. 1 2 3 4 5 6 2–1 Fine gravel 0.49 0.04 1.53 0.00 0.00 1.34 1–0.5 Coarse sand 4.96 1.97 5.67 0.40 0.23 0.33 0.5–0.25 Medium sand 40.19 28.64 13.25 0.57 1.29 1.08 0.25–0.1 Fine sand 27.59 39.68 8.39 22.64 4.03 1.02 0.1–0.05 Very fine sand 12.10 11.43 14.95 30.55 11.57 6.94 0.05–0.01 Silt 7.74 4.95 28.86 13.98 38.97 29.05 0.01–0.005 Fine silt 2.23 2.02 7.84 4.08 8.84 11.03 0.005–0.0001 Clay 4.40 8.79 14.55 21.98 32.70 43.44 ————— ————— ————— ————— ————— ————— 99.70 97.52 95.04 94.20 97.63 94.23 Org. matter, water and loss 0.30 2.48 4.96 5.80 2.37 5.77 =242. Description of the Soils.=—Number one represents the very early truck lands of southern Maryland. It is a light yellow sand, belonging to the Columbia terrace formation. Under an intense system of cultivation and heavy manuring with organic matter, good crops of garden vegetables are produced which mature very early, at least ten days or two weeks before the crops from any other part of the state. Under the prevailing meteorological and cultural conditions this soil maintains about five or six per cent of moisture, while a heavier wheat and grass soil maintains from twelve to twenty per cent. The truck soil is so loose and open in texture that the rain-fall passes through it very readily, and it is undoubtedly owing to this drier soil that the plant is forced to the early maturity which secures it from competition from other parts of the State and insures a good market price. Number two represents the later truck and fruit lands of southern Maryland. These lands contain rather more clay than those just described; they are somewhat heavier and closer in texture, and are rather more retentive of moisture. This land gives a larger yield per acre than the one just described, and in every way crops make a more vigorous growth and development, but the crop is about a week or ten days later in maturing, and for this reason it brings a lower price in the market. It is much better land than number one for small fruit and peaches. These lands are altogether too light in texture for the profitable production of wheat, and it would cost altogether too much to improve them so that even a moderate yield of wheat could be obtained. Number three is a tobacco land of southern Maryland. The finest tobacco lands of this locality come between the truck and wheat lands in texture, and contain from ten to twenty per cent of clay. The lighter the texture of the soil and the less clay it contains, the less tobacco it will yield per acre, but the finer the texture of the leaf. The tobacco yields more per acre on the heavier wheat soils, but the leaf is coarse and sappy and cures green and does not take on color. It brings a very low price in the market and does not pay for cultivation. The crop on the lighter lands is of much finer quality; there is a smaller yield per acre but the leaf takes on a fine color in curing, and brings a much better price per pound. Wheat is commonly raised on these tobacco lands to get advantage of the high manuring, and because the rotation is better for the land than where tobacco is grown continuously on the same soil. The finest tobacco lands are, however, too light in texture for the profitable production of wheat. These lands belong to the neocene formation. Number four is a type of the wheat lands of southern Maryland. These lands represent soil of about the lightest texture upon which wheat can be economically produced under the climatic conditions which there prevail. They contain from eighteen to twenty-five per cent of clay, and are much more retentive of moisture than the best tobacco lands. This type is about the limit of profitable wheat production. These soils will maintain about twelve per cent of water during the dry season. Garden truck is so late in maturing on these lands that there is often a glut in the market when the crop matures, and the crops often do not pay the cost of transportation. The lands are too light in texture for a permanent grass sod. They belong to the neocene formation. Number five represents the heavier wheat lands of southern Maryland, belonging probably to a different horizon of the neocene formation and containing about thirty per cent of clay. This soil is much more retentive of moisture and produces very much larger crops of wheat than the last sample. It is strong enough and sufficiently retentive of moisture to make good grass lands. It is too close in texture and too retentive of moisture for the production of a high grade of tobacco, or to be profitable for market truck. Number six is from a heavy limestone soil of lower Helderberg formation. It is a strong and fertile wheat and grass land. =243. Interpretation of Silt Analysis.=—The primary conceptions upon which the interpretation of the mechanical analysis is based may be briefly stated as follows:[161] The circulation of water in the soil is due to gravity, or the weight of water, acting with a constant force to pull the water downward, and also to surface tension, or the contracting power of the free surface of water (water-air surface), which tends to move the water either up or down, or in any direction, according to circumstances. There is a large amount of space between the grains in all soils in which water may be held, ranging from about thirty per cent in light sandy lands to sixty-five or seventy per cent in stiff clay soils. The relative rate of movement of water through a given depth of soil will depend upon how much space there is in the soil; upon how much this space is divided up, _i. e._, upon how many grains there are per unit volume of soil; upon the arrangement of the grains of sand and clay; and upon how this skeleton structure is filled in and modified with organic matter. It also appears that the ordinary manures and fertilizers change this surface tension, or pulling power of water; that they also change the arrangement of the grains, and consequently the texture or structure of the soil may be changed and the relation of the soil to water, through the effect of the ordinary manures and fertilizers in causing flocculation or the reverse. =244. Number of Particles in a Given Weight of Soil.=—The approximate number of particles in the soil can be calculated from the results of the mechanical analysis by the following formula:[162] (_a_/((π(_d_)³ω)/6)) ÷ A Where _a_ is the weight of each group of particles, _d_ the mean diameter of the particles in the several groups in centimeters, ω is the specific gravity of the soil, and A is the total weight of soil. For the specific gravity of ordinary soils, the constant 2.65 may be used. In using the formula the per cents are expressed as grams. Thus, if there were twenty per cent of silt, this would be taken as twenty grams, and if the results of the analysis added up ninety-seven per cent the whole weight of soil would be taken as ninety-seven grams. The diameter _d_ is taken as the mean for the extreme diameters taken for any group, for instance, for the silt this would be 0.003 centimeter, which is assumed to be the diameter of the particles in that group. This formula can only give approximate values, as the number of separations in a silt analysis must necessarily be small, amounting usually to not more than eight or ten grades, on account of the time and labor required for closer separations. There is relatively rather a wide range in the diameters of grains within any one of these grades, and absolute values could not be expected without a vast number of separations, so that all the grains in each group would be almost exactly of the same size. The clay group has relatively the widest limits, which is unfortunate, as this is the most important of all the groups on account of the exceedingly small size of the particles. The figure 0.0001 millimeter is taken as the lowest limit of the diameter of the clay particles. These particles have been heretofore assumed to be ultra-microscopic, but by the use of a microscope of high power with oil-immersion objective and staining fluids, it has been possible to define the clay particles in a turbid liquid which has stood so long as to be only faintly opalescent. Pending more exact measurements, the figure 0.00255 millimeter has been used as the diameter of the average sized particle in the clay group. The following table gives the approximate number of grains per gram in the different types of subsoils calculated from the mechanical analysis of the typical soils already given: NUMBER OF PARTICLES OF EACH CLASS IN ONE GRAM OF SOIL. ─────────────────┬─────────────────┬─────────────────┬───────────────── Silt classes. │ No. 1 │ No. 2│ No. 3 Diameter (_d_) in│ Early truck. │ Truck and small│ Tobacco. centimeters. │ │ fruit.│ ─────────────────┼─────────────────┼─────────────────┼───────────────── 0.15 │ 0│ 0│ 3 0.075 │ 85│ 34│ 102 0.0375 │ 5,511│ 4,011│ 1,900 0.0175 │ 37,230│ 54,610│ 11,890 0.0075 │ 207,500│ 199,700│ 267,900 0.003 │ 2,073,000│ 1,355,000│ 8,092,000 0.00075 │ 38,210,000│ 35,360,000│ 140,900,000 0.000255 │ 1,915,000,000│ 3,918,000,000│ 6,637,000,000 │ —————————————│ —————————————│ ————————————— │ 1,955,000,000│ 3,954,973,355│ 6,786,273,795 ─────────────────┼─────────────────┼─────────────────┼───────────────── Silt classes. │ No. 4 │ No. 5 │ No. 6 Diameter (_d_) in│ Wheat. │Grass and wheat. │ Limestone. centimeters. │ │ │ ─────────────────┼─────────────────┼─────────────────┼───────────────── 0.15 │ 0│ 0│ 12 0.075 │ 726│ 4│ 60 0.0375 │ 8,273│ 181│ 157 0.0175 │ 32,340│ 5,556│ 1,456 0.0075 │ 554,100│ 202,600│ 125,900 0.003 │ 3,962,000│ 10,670,000│ 8,231,000 0.00075 │ 73,990,000│ 154,900,000│ 199,900,000 0.000255 │ 10,150,000,000│ 14,570,000,000│ 19,430,000,000 │ ——————————————│ ——————————————│ —————————————— │ 10,228,547,439│ 14,735,778,341│ 19,638,258,585 ─────────────────┴─────────────────┴─────────────────┴───────────────── =245. Estimation of the Surface Area of Soil Particles.=—The approximate extent of surface area of the soil grains in one gram of soil can be calculated from the foregoing by the following formula:[163] π(_d_)²_n_ in which _d_ is the mean of the diameters of any group in centimeters, and _n_ is the number of particles in the group. The following table gives the approximate extent of surface area of the particles in one gram of soil calculated from the preceding table: APPROXIMATE EXTENT IN SQUARE CENTIMETERS, OF SURFACE AREA IN ONE GRAM OF SOIL. Soil number. ————— —————— —————— —————— —————— —————— Diameter, millimeters. 1 2 3 4 5 6 1.5 0.0 0.0 0.4 0.0 0.0 0.1 0.75 1.8 0.6 1.8 12.8 0.1 0.1 0.375 24.3 17.7 8.4 36.5 31.0 0.7 0.175 35.8 52.6 11.4 31.1 5.3 1.4 0.075 21.3 35.3 47.3 97.9 35.8 22.2 0.03 218.8 38.3 228.9 112.0 301.4 232.7 0.0075 67.4 62.5 248.9 130.8 273.5 353.4 0.00255 390.8 800.5 1355.0 2072.0 2976.0 3965.0 ————— —————— —————— —————— —————— —————— Total 760.2 1007.5 1902.1 2493.1 3593.1 4575.3 =246. Logarithmic Constants.=—The following logarithmic constants have been used in the calculation of the approximate number of grains per gram and of the surface area, using 2.65 in all cases as the specific gravity of the soil. Diameter. (_d_) Approximate number of grains. Surface area. log.(π(_d_)³_w_)/(6) log.(_d_)²π 0.15 centimeters \̅3.6703 \̅2.8493 0.075 „ \̅4.7674 \̅2.2473 0.0375 „ \̅5.8641 \̅3.6451 0.0175 „ \̅6.8711 \̅4.9831 0.0075 „ \̅7.7674 \̅4.2473 0.003 „ \̅8.5734 \̅5.4513 0.00075 „ \̅1̅0.7674 \̅6.2473 0.000255 „ \̅1̅1.3616 \̅7.3101 =247. Mineralogical Examination of the Particles of Soil Obtained by Mechanical Analysis.=—The principal object of the mechanical analysis of soils as has already been set forth is the separation of the soil into portions, the particles of which have the same hydraulic value. It is evident without illustration that particles of the same hydraulic value do not necessarily have the same size. The rate of flow of a liquid carrying certain definite particles does not imply that these particles are of the same dimensions. Of two particles of the same size and shape, that one which has the lower specific gravity, will be carried off at the lower rate of flow. At the end of the operation, therefore, the several portions of the soil obtained will be found composed of particles of sizes varying within certain limits, and of these particles the larger ones will tend to be composed of minerals of lower specific gravity, and the smaller ones of minerals of higher specific gravity. Of the same mineral substance, the particles which are most irregular, exposing for a given weight the largest surface will be found to pass over at a lower velocity than those of a more nearly spherical shape. The same law holds good for particles falling through a liquid at rest, _i. e._, the heavier and more spherical particles, weight for weight, will sooner reach the bottom of the containing vessel. To complete the value of a mechanical analysis, it becomes necessary to submit the several portions of soil obtained not only to a chemical but also to a mineralogical examination. Only the outlines of the methods of examining silt separates for mineral constituents can be given here and special works in petrography must be consulted for greater details.[164] It is evident that the methods of separation and examination from a mineralogical point of view about to be described can only be applied to silts of the largest size. The finer silts can not be separated into portions of different specific gravities by separating liquids of varying densities on account of the slowness with which they subside, thus tending to adhere to the sides of the separating vessels and to form floccules which are not all composed of the same kind of mineral particles. While, therefore, these processes are more appropriately described in connection with the silts obtained by hydraulic elutriation, they can be applied with greater success to the fine particles passing the different sieves used in the preparation of the soil for analysis or to the finely pulverized soil as a whole. The minerals which have contributed to soil formation, moreover, are better preserved in the larger silt particles and therefore more easily identified. While the desirability of securing like determinations in the finer silts is not to be denied, in the present state of the art the analyst must be content with the examination of the larger particles. =248. Methods of Investigation.=—The chief points to be observed in the examination of the fine particles of soil are the following: (1) the size and shape of the particles; (2) measurement of crystal angles; (3) separation into classes of approximately the same specific gravity; (4) separation by means of the magnet; (5) determination of color and transparency; (6) determination of refractive index; (7) examination with polarized light; (8) examination after coloring; (9) chemical separation. For many of the optical studies above noted, it is first necessary to prepare thin laminae of the mineral particles and properly mount them for examination. For the purposes of this manual only those processes will be described which are essentially connected with a proper understanding of the nature of the soil particles. For the more elaborate methods of research the analyst will consult the standard works on mineralogy and petrography. =249. Microscopical Examination.=—The direct examination of the silt particles with the microscope should attend the progress of separation. Unless the particles obtained have the same general appearance, the separation is not properly carried on. Especially is the microscope useful to determine that the value of the silt separation is not impaired by flocculation. Unless flocculation be practically prevented during the separation of the finest particles, many of these will be left as aggregates to be brought over subsequently with particles of far different properties. No special directions are necessary in the use of the microscope. The silt particles are removed with a few drops of water by means of a pipette, a drop of the liquid with the suspended particles is placed on the glass, covered and examined with a convenient magnification. A micrometer scale should be employed in order that the approximate sizes of the particles may be determined. A _camera lucida_ may also be conveniently used for the purpose of delineating the form of particles of peculiar interest. =250. Petrographic Microscope.=—Any good microscope furnished with polarizing apparatus may be used for the examination of the silt particles and sections. For directions in manipulating microscopes the reader is referred to works on that subject. A special form of microscope for petrographic work is made by Bausch and Lomb of Rochester. The stand of this instrument is shown in Fig. 37. The base, upright pillars and arm are made of japanned iron. The stage is made in two forms, first, plain revolving, having silvered graduates at right angles and second, a mechanical stage with silvered graduations on the edge with vernier and graduations for the rectangular movements. The mirror bar is adjustable and graduated and the mirror is of large size, plane and concave. The double chambered box in the main tube carries the upper Nicol prism (analyzer). The lower Nicol prism (polarizer) is mounted in a cylindrical box beneath the stage to which it is held by a swinging arm. It is adjustable also up or down and is provided with a compound lens for securing converged polarized light. In revolving the prism a distinct click shows the position of the crossed Nicols. FIGURE 37. ] =251. Form and Dimensions of the Particles.=—In order to study the contour of the fine silt particles, it is well to suspend them in a liquid whose refractive index is markedly lower than that of the particles themselves, and for this purpose pure water is commonly used. Care must be taken that not too many particles are found in the drop of water which is to be placed on the object holder and protected with a thin, even glass. The tendency to flocculation in these fine particles will make the study of their form difficult if they are allowed to come too close together. The size of the particles, or linear diameter, is to be determined by means of an eye-micrometer. This consists of a glass plate on which a millimeter scale is engraved with a diamond, or photographed. The millimeter scale is the one usually employed, each millimeter being divided into tenths. On microscopes designed especially for photographic work the micrometer is fastened to the eyepiece, and so adjusted as to read from left to right, or at right angles thereto. Sometimes an eyepiece-micrometer has two scales at right angles so that dimensions may be read in two directions without change. With an eyepiece-micrometer, not the dimensions of the object, but those of its magnified image are read, and the degree of magnification being known, the actual size of the object is easily calculated. The actual measurements may also be obtained by placing in the field of vision, a stage-micrometer and determining directly the relation between that and the eyepiece-scale. If, for example, the stage-micrometer is ruled to 0.01 millimeter, and the eye-micrometer to 0.1 millimeter, and one division of the stage-rule should cover three divisions of the eye-rule, then the one division of the eye-micrometer would correspond to an actual linear distance of 0.0033 millimeter in the object. If the two lines of division in the two micrometers do not fall absolutely together, the calculation may be made as follows: suppose that six divisions, 0.6 millimeter, in the eyepiece correspond to nearly five divisions, 0.25 millimeter, in the stage piece. To get at the exact comparison, take ninety-six divisions of the eye-scale and they will be found to be somewhat longer than eighty-one and somewhat shorter than eighty-two divisions of the stage-scale. It follows therefore that one division of the eye-scale >0.008438 millimeter, and „ „ „ „ „ „ <0.008541 „ ; and, hence, one division of the eye-scale corresponds almost exactly to 0.008489 linear measure. =252. Illustrations of Silt Classes.=—In figure 38 are shown the relative sizes and usual forms of a series of silt separates made by the Osborne beaker method. The photomicrographs were made by Dr. G. L. Spencer from specimens furnished by Prof. M. Whitney. The soil represented by the separates is from a truck farm near Norfolk, Virginia. The particles represented in each class are not all strictly within the limits of size described. For instance, in the largest size (No. 1) are two particles at least which show a diameter of more than one millimeter. The particles in general, however, are within the limits of the class; _viz._, one-half to one millimeter, and this general observation is true of all the classes. In the case of the finer particles, especially of clay, the tendency to flocculation could not be overcome in the preparation of the slides for the photographic apparatus. The clay particles are so fine as to present but little more than a haze at 150 diameters of magnification. The particles seen are clearly, in most cases, aggregates of the finer clay particles. The larger particles show the rounded appearance due to attrition and weathering. It would have been more instructive to have had the particles of the different classes all photographed on the same scale, but this is manifestly impossible. The lowest power which shows any of the clay particles to advantage is at least 150 diameters, and with the larger particles such a magnification would have been impracticable. =253. Measurement of Crystal Angles.=—The fine silt particles rarely retain sufficient crystalline shape to permit of the measurement of angles and the determination of crystalline form thereby. The rolling and attrition to which the silt particles have been subjected have, in most cases, given to the fragments rounded or irregular forms which render, even in the largest silts, the measurement of angles impossible. For the methods of mounting minute crystals and the measurement of microscopic angles, the analyst is referred to standard works on mineralogy and petrography. =254. Determination of the Refractive Index.=—For a study of the theory of refraction, works on optics should be consulted. The general principles of this phenomenon which concern the determination of the refractive power of fine earth particles are as follows: if a transparent solid particle is observed in the microscope imbedded in a medium of approximately the same refractive power and color, its outlines will not be clearly defined, but the imbedded particle will show in all of its extent the highest possible translucency. If, therefore, the form or perimeter of the particle is to be studied with as much definiteness as possible, it should be held in a medium differing as widely from it as possible in refractive power. For minerals, water is usually the best immersion material. On the other hand, when the internal structure of the particles is the object of the examination, it should be imbedded in oil, resin (Canada balsam), etc., or in some of the liquids mentioned below. If particles of different refractive powers and the same character of surface be studied in the same medium, they will not all appear equally smooth on the field of the microscope. Some of the surfaces will seem smooth and even, others will appear rough and wrinkled. Those particles whose refractive index is equal to or less than that of the liquid appear smooth, because all the emergent light therefrom can pass at once into the environing medium. On the other hand, the surfaces of those particles which have a higher refractive power than the medium will appear roughened, because, on account of the unavoidable irregularities on the surface, many of the emergent rays of light must strike at the critical angle and so suffer total reflection, and consequently those portions of the surface will be less illuminated, producing the phenomenon of apparent roughness above noted. In the case of any given particle, liquids of increasing refractive power can be successively applied until the change in the appearance of the surface of the particle is noticed. The refractive index of the liquid being known, that of the particle is in this way approximately to be determined. The following liquids, having the indexes mentioned, are commonly employed: Substance. Refractive index. Water 1.333 Alcohol 1.365 Glycerol 1.460 Olive oil 1.470 Canada balsam 1.540 Oil of cinnamon 1.580 Oil of bitter almonds 1.600 Oil of Cassia 1.606 Concentrated solution of potassium and mercuric iodid 1.733 Concentrated solution of barium and mercuric iodid 1.775 The solution of potassium and mercuric iodid may also be used for all refractive indexes from 1.733 to 1.334 by proper dilution with water. The mineral particle may also be imbedded in Canada balsam and over it a drop of a liquid of known refractive power placed. By a few trials one of the liquids will be found having practically the refractive index of the particle under examination. =255. Examination with Polarized Light.=—The internal structure of a mineral particle can often be determined by its deportment with polarized light. The theory of polarization is fully set forth in works on optics and will not be discussed here. The principle on which the utility of polarized light in the examination of soil particles rests is found in the information it may give in respect of crystalline structure. The structure of mineral particles which make up the bulk of an ordinary soil is, as a rule, so thoroughly disintegrated that all trace of its original form is lost. Some particles may exist, however, in which there is no determinable element of shape and which yet possess an internal crystalline structure which the microscope with polarized light may be able to reveal. =256. Staining Silt Particles.=—The finer silts and clays before microscopic examination should be colored or stained. The methods used in staining bacteria may be employed for the clay particles. Evaporation to dryness with a solution of magenta will often impart a color to the clay particles which is not removed by subsequent suspension in water. The harder and larger silt particles are not easily stained, especially if they be firm and undecomposed. On the other hand, if the particles be broken and seamed, and well decomposed, the stain will be taken up and held firmly in the capillary fissures. Valuable indications are thus obtained respecting the nature of the silt particles. Particles of mica, chlorite and talc are easily distinguished in this way from the firmer and less decomposed quartz grains. The staining of the particles after ignition and treatment with acids gives better results than the direct treatment. Particles of carbonate which are stained with difficulty before ignition take the stain easily afterwards on account of the decomposition produced by the loss of carbon dioxid. This is the case also with particles containing water of composition or crystallization. =257. Cleavage of Soil Particles.=—A microscopic examination of the cleavage of soil particles may be useful in determining their mineral origin. The course followed by cleavage lines and their mutual position is dependent on the direction in which the separation of the mineral fragment takes place. The character of the microscopic fragments produced by crushing a soil particle is determined primarily by the system of crystallization to which it belongs. Perhaps the most distinguishing cleavage marks in soil particles will be found in fragments of mica and orthoclase. These characteristic forms are shown in Figs. 39 and 40. The first (Fig. 39) shows the pinacoidal cleavage in a fragment of mica. Fig. 40 illustrates the appearance of the cleavage lines in a fragment of orthoclase. Figs. 41 and 42 show the characteristic cleavage lines in fragments of epidote and titanite. =258. Microchemical Examination of Silt.=—The methods of quantitative chemical examination of silts will be given in another part of this manual. Certain qualitative and microchemical tests, however, are useful in identifying silt particles. For instance, any soluble iron mineral will be detected, even in minute quantity, by the blue coloration of the solution produced by the addition of potassium ferrocyanid. Manganese will be revealed by fusion with soda and saltpeter on platinum foil, in the oxidizing flame, producing the well-known green coloration due to the sodium manganate formed. More valuable indications of the character of the fragments examined are obtained by microchemical processes. The best method of decomposing the silt particles for this purpose is by treatment with hydrofluosilicic acid. When the particles are composed of silicates, pure hydrofluoric acid is to be preferred. The method of treatment is essentially that of Boricky.[165] The slide used is protected by a film of Canada balsam, and a few of the silt particles are placed thereon, and fixed in place by slightly warming the balsam. Each particle is then treated with a drop of hydrofluosilicic acid, care being taken not to let the drops flow together. The acid must be pure, leaving no residue on evaporation. The acid should be prepared by the analyst from a mixture of barium fluorid, sulfuric acid and quartz powder, or the commercial article should be purified by distillation before using. The acid should be kept in ceresin or gutta-percha bottles and must be applied with a ceresin or gutta-percha rod. Each particle should be as completely dissolved as possible by the acid, and the rate of solution may be hastened by gentle warming, provided the heat is not great enough to remove the balsam and allow the acid to attack the glass. The bases present in the silt particles crystallize on drying as fluosilicates. In case of a too rapid crystallization, the mass may be dissolved in a drop of water or of very dilute hydrofluosilicic acid, and allowed to evaporate more slowly. Some fragments need more than one treatment with acid to secure complete solution, and particles of mica may even resist repeated applications. In such a case the decomposition may be made in a platinum crucible with hydrofluoric acid, adding afterwards an excess of hydrofluosilicic acid and evaporating to dryness. The crystals may then be dissolved in a little water and a drop of the solution allowed to crystallize on the slide. =259. Special Reactions.=—The number of microchemical reactions is very great, but there will be given here only some of the more important for silt identification. _Sodium._—Sodium mineral fragments dissolved in hydrofluosilicic acid and dried give the combinations shown in Fig. 43. With sodium and aluminum the forms shown in Figs. 44 and 45 are obtained. With an increasing amount of lime in the mineral, the crystals tend to become longer. For microscopic work it is not advisable to try to produce the tetrahedral crystals of the double uranium sodium acetate because the commercial uranium acetate often contains sodium and even the pure article will often take up sodium from the bottles. _Potassium._—Fragments containing potash give isotropic clear cubes, or octahedra of low refracting power, or combinations of these forms with each other and with rhombic dodecahedra. These crystals have the composition K₂SiF₆. Their forms are shown[166] in Figs. 46 and 47. In case much sodium be present, the first crystals obtained may be strongly double refractive rhombohedra, but on dissolving in water and allowing to recrystallize, the normal forms will be obtained. If the crystals be dissolved in hydrochloric or sulfuric acids, and treated with platinum chlorid, the characteristic yellow octahedral crystals of K₂PtCl₆ will be obtained. Ammonium and cesium compounds also give this reaction. _Lithium._—When fragments containing lithium are treated with the solvent mentioned, monoclinic crystals are produced on drying. These crystals dissolved in sulfuric acid and freed from calcium sulfate by treatment with potassium carbonate give aggregates of lithium carbonate resembling a snowflake. At a high temperature lithium solutions treated with sodium phosphate give spindle-shaped crystals of lithium phosphate. The double lithium aluminum silicofluorid is shown in Fig. 48. The ease with which traces of lithium may be detected by the spectroscope renders unnecessary any further description of its microchemical reactions. _Calcium._—Nearly all mineral particles, save quartz grains, contain calcium. When these particles are dissolved by treatment with hydrofluosilicic acid, they form on drying hydrated monoclinic crystals of calcium silicofluorid (CaSiF₆ + 2H₂O). These crystals assume many forms, some of which are shown in Figs. 49 and 50. These crystals are easily decomposed by sulfuric acid, the well-known long prismatic crystals of gypsum taking their place. On treatment of silt particles containing lime with hydrofluoric and sulfuric acids, only a part of the lime passes into solution if the content thereof be large. Where but little lime is present and the sulfuric acid is in large excess, all the lime passes into solution and the characteristic gypsum crystals appear as in Fig. 51. _Magnesium._—Rhombohedral crystals of magnesium silicofluorid separate from the solution of particles containing magnesium in hydrofluosilicic acid. They have the composition MgSiF₆6H₂O and their common forms are shown in Fig. 52. Quite characteristic also are the crystals of struvite (NH₄MgPO₄ + 6H₂O), which are produced in a very dilute solution of the magnesium compound first obtained by carefully adding ammonium hydroxid and chlorid until a faint alkaline reaction is produced, and then placing a drop of dilute sodium phosphate at the edge of the solution. The crystals should be allowed to form slowly in the cold. Their form is shown in Fig. 54. FIGURE 38. PHOTOMICROGRAPHS OF SILT PARTICLES. ] No. Diameter in mm. Name. Magnification. Diameters. 1 1.0–0.5 coarse sand ×10 2 0.5–0.25 medium sand ×10 3 0.25–0.1 fine sand ×10 4 0.1–0.05 very fine sand ×30 5 0.05–0.01 silt ×30 6 0.01–0.005 fine silt ×150 7 0.005–0.0001 clay ×150 Figures 39–42, show examples of the various degrees of perfection and relative positions of cleavage lines. Figure 39, illustrates pinacoidal cleavage in mica from granite. Magnified thirty diameters. Figure 40. A cleavage of orthoclase from augite syenite magnified twenty-seven diameters. Figure 41. Cleavage of epidote magnified sixty diameters. Figure 42. Cleavage of titanite magnified seventy-five diameters. Figure 43. Sodium fluosilicate crystals magnified seventy-two diameters. Figure 44. The same with aluminum fluosilicate magnified twenty-seven diameters. Taken from Rosenbusch, Mikroskopische Physiographie. ] Figure 45. Sodium and aluminum silicofluorid crystals magnified 100, 140 and 160 diameters. Figure 46. Potassium silicofluorid crystals magnified 130 diameters. Figure 47. Another preparation of the same magnified 140 diameters. Figure 48. Lithium and aluminum silicofluorid crystals magnified 100 diameters. Figure 49. Calcium silicofluorid crystals magnified 45 diameters. Figure 50. Another preparation of the same magnified 42 diameters. ] Figure 51. Calcium sulfate crystals magnified twenty diameters. Figure 52. Magnesium silicofluorid crystals magnified thirty diameters. Figure 53. Cesium aluminum sulfate crystals magnified twenty diameters. Figure 54. Ammonium magnesium phosphate crystals magnified ten diameters. Figure 55. The same crystallized from dilute solution magnified thirty diameters. Figure 56. Ammonium phosphomolybdate crystals magnified 140 diameters. ] _Barium._—From solution of barium bearing minerals in hydrofluosilicic acid fragments, no characteristic crystals, are obtained. Treated with hydrofluoric and sulfuric acids the barium is left as sulfate. If this salt be dissolved in boiling oil of vitriol and a drop of the solution placed on the slide, a mixture of rectangular tablets and St. Andrew’s cross-shaped growths will be separated before any crystals of gypsum which may be present appear. When strontium is present, the barium sulfate residue obtained by treatment with hydrofluoric and sulfuric acids should be fused with sodium and potassium carbonate, washed with water until the sulfuric acid is removed, the residue dissolved in hydrochloric or nitric acids, and the solution treated with potassium chromate. Pale yellow crystals of barium chromate are thus obtained, which resemble in form those secured by dissolving the barium sulfate in oil of vitriol. Strontium is not precipitated by this treatment. If potassium ferrocyanid be used instead of barium chromate with the hydrochloric acid solution, crystals of barium potassium ferrocyanid are formed of a bright yellow color and rhombohedric shape. _Strontium._—From a hydrofluosilicic acid solution, strontium crystallizes in columns or tablets of the monoclinic system as strontium silicofluorid, SrSiF₆. On treating these with sulfuric acid, rhombic plates of strontium sulfate are formed, which serve to distinguish this element from calcium. On treatment of the particles of the original mineral with hydrofluoric and sulfuric acids, the strontium remains in the insoluble residue. When this residue is treated with boiling oil of vitriol, rhombic plates of celestine are separated. If the residues above mentioned be dissolved by fusion with the alkaline carbonates, washed with water, dissolved in hydrochloric acid and treated with oxalic acid, octahedral crystals of strontium oxalate are formed. _Iron._—Mineral particles containing iron give crystals, when treated as is first described above, which are fully isomorphous with those obtained from magnesium. By moistening the crystalline mass with potassium ferrocyanid, the presence of iron is at once revealed by the blue coloration produced. _Aluminum._—No crystals containing aluminum are formed from the mineral particles containing this substance when dissolved in the solvent already mentioned. If, however, the gelatinous mass be dissolved in a little sulfuric acid and a fragment of a cesium salt added, beautiful crystals of cesium alum are obtained, illustrated in Fig. 53. _Phosphorus._—When a mineral fragment containing phosphorus is treated according to the usual analytical methods for securing the ammonium magnesium phosphate, crystals are obtained of the form shown in Figs. 54 and 55. A phosphatic fragment of silt may be identified when soluble by treatment with nitric acid and ammonium molybdate. On slowly drying, rhombohedral crystals are produced, yellow by reflected, and green by transmitted light. Their form is shown in Fig. 56. =260. Petrographic Examination of Silt Particles.=—The larger silt particles and the minute fragments of minerals in the soil can best be studied in thin sections. For this purpose the following plan, proposed by Thoulet, may be used. Mix the soil minerals in considerable proportion—Thoulet recommends ten per cent, but a greater percentage is often better—with zinc oxid and make into a paste with sodium silicate. The paste should be worked to the consistence of putty and then rolled into little tablets about one-eighth of an inch thick and an inch in diameter. After drying a day or two without heating, the tablets become hard enough to mount and grind like rock sections. These tablets are mounted in Canada balsam on glass slides and ground as thin as possible with fine emery on the turn-table or glass plate, as rock sections are treated. As these tablets are not as strong as rock sections usually are, they require care in this treatment. Some of the grains also are apt to be torn out in the process of grinding and to compensate for this loss a number of slides should be prepared with each lot of soil minerals. When this operation has been successful, the optical properties of the various minerals can be studied as in rock sections. As the iron oxid contained in the soils obscures the transparency of the minerals, it is well to treat a portion of the material under examination with hot hydrochloric acid for a short time to remove this oxid and then prepare slides with the cleansed material and compare results with the untreated. As the acid will dissolve phosphates and carbonates, and will partly or wholly decompose some other minerals, the operator must be guided by his judgment in its use. =261. Machine for Making Mineral Sections.=—A convenient apparatus for this purpose has been described by Williams[167] and is represented in Fig. 57. It is supported on a substantial table provided underneath with electric batteries and a motor for driving the cutting disks seen on the top. The table is three feet six inches square and two feet nine inches high. FIGURE 57. MACHINE FOR MAKING MINERAL SECTIONS. ] The grinding apparatus consists of two circular disks of solid copper, nine inches in diameter, and three-eighths inch thick, which may be used alternately as different grades of emery are required. They are attached either by a screw or square socket to a vertical iron spindle which revolves smoothly in a conical bearing. The grinding disk is surrounded when in use by a large cylindrical pan of tin, which is not shown in the cut, which has an opening in its center to allow of the passage of the spindle. The sawing apparatus consists of a horizontal countershaft placed on a different part of the table and connected with the motor by a separate belt. It carries at one end a vertical wheel of solid emery, and at the other an attachment, level-table and guide for the diamond-saw. A small water-can with spout, not shown in the cut, is suspended over the edge of the table to keep the saw wet when it is in use. The machine is very conveniently driven by a storage battery when street circuits cannot be drawn on. For the details of making mineral sections, the works on petrography may be consulted. =262. Separation of Silt Particles by Specific Gravity Solutions.=—In silt separates the specific gravity of the different mineral particles present may vary from graphite (1.9–2.3) to hematite (5.2–5–3). The following list gives the specific gravities of some of the more common minerals which may be met with in soils: Gypsum 2.31 Albite 2.56–2.63 Quartz 2.65 Talc 2.74 Chlorite 2.78 Muscovite 2.85 Calcite 2.5–2.78 Dolomite 2.90 Tourmaline 2.94–3.3 Biotite 3.01 Apatite 3.16 Pyroxenes 3.22–3.5 Epidote 3.39 Titanium Minerals 3.48–4.75 Iron oxids 5.2–5.3 The finest particles of silt are separated by gravity with great difficulty, inasmuch as they tend to remain suspended in the solutions for an indefinite period. With the coarser silts, however, useful data are often obtained by this method. The separation is preceded by extraction of the particles with hydrochloric acid to remove encrusted soluble matter, and by ignition to destroy any traces of organic matter. Those mineral matters which are soluble in acid or are changed by ignition must, of course, be sought for in separate portions of the silt, =263. Thoulet’s Solution.=[168]—The standard solution is of such a density that particles of 2.65 specific gravity-will just float thereon, using for this purpose a solution of about 2.7 specific gravity. The solution from which the above standard is prepared is made as follows: One part of potassium iodid is weighed and placed in a beaker and one and one-quarter part of mercuric iodid is placed on top of it. Then water is added in the proportion of ten cubic centimeters to 100 grams of the mixture, and after some time (twelve to twenty-four hours), with occasional stirring, the salts will nearly completely dissolve. Filter from the undissolved residue and evaporate in a porcelain dish until crystals form on the surface of the liquid. Allow to cool, pour off the liquid from the crystals and evaporate the liquid for another crop. The first solution, after cooling, has a specific gravity between 3.10 and 3.20, the second a specific gravity of 3.28, practically the limit of density of the solution. The solution of 2.7 specific gravity and other densities are made by cautiously adding a few drops of water at a time and ascertaining the specific gravity by the Westphal balance or other convenient method. The strong solution, according to Goldschmidt,[169] may be prepared directly by using potassium iodid and mercuric iodid in the ratio of 1 : 1.24. Twenty-five cubic centimeters of water, 210 grams of potassium iodid, and 280 grams of mercuric iodid afford a solution of 3.196 specific gravity at 15°, on which fluorspar fragments will float. =264. Klein’s Separating Liquid.=—A solution of cadmium borotungstate, of the composition 2H₂O,2CdO,B₂O₃,9WO₃ + 16H₂O, has been proposed by Klein[170] for separating silt particles. This salt is obtained by dissolving pure sodium tungstate in five times its weight of water, adding one and a half parts of boric acid and boiling until, complete solution takes place. On cooling; the borax is separated in crystalline form. The mother-liquor after the removal of the crystals is carefully concentrated by boiling. By stirring the cold solution, there is a further separation of sodium borate and polyborate. This operation is continued until glass will float on the mother-liquor. The salt in solution then has the following composition: 4Na₂O,12WO₃,B₂O₃. To this boiling concentrated solution, is added a boiling saturated solution of barium chlorid, in the proportion of one part of the chlorid to three parts of the original double tungstate. An abundant pulverulent precipitate is formed, making the whole mass mushy. The mass is filtered under pressure and well-washed with hot water. The residue is then suspended in hot water containing one part in ten of hydrochloric acid of 1.18 specific gravity. It is then evaporated to dryness in the presence of an excess of hydrochloric acid and decomposed, by which process hydrated tungstic acid is separated. The boiling mass is taken up with water and the boiling continued for two hours with occasional addition of water to take the place of that evaporated, and the tungstic acid separated by filtration. From the solution, beautiful quadratic crystals separate having the composition 9WO₃,B₂O₃,2BaO₂H₂ + 18H₂O. These are purified by several recrystallizations and freed from any scales of boric acid by washing with alcohol. Any reducing action, revealed by a violet coloration of the crystals, can be avoided by adding a few drops of nitric acid. From a boiling solution of these crystals, the cadmium salt desired is obtained by treatment with the proper amount of cadmium sulfate solution to precipitate the barium. The barium sulfate is separated by filtration. The cadmium borotungstate is soluble in less than ten parts by weight of water. From this solution it is obtained in pure form by evaporation under a vacuum, or by carefully concentrating on a water-bath and cooling. A saturated solution of these crystals at 15° has a bright yellow color and a specific gravity of 3.28. If a dilute solution of the above salt be carefully evaporated on a water-bath, any violet color which may be present disappears when the specific gravity reaches 2.7. If the evaporation be continued until a crystal of augite will float on the hot liquid, crystals may be obtained on cooling which, dissolved in as little water as possible, make a solution which will almost support olivine. If the two solutions be united, the specific gravity of the mixture is 3.30–3.36. The highest attainable specific gravity; _viz._, 3.6, is produced by continuing the evaporation on a water-bath until the liquid will support olivine, and then allowing to stand in a closed place for twenty-four hours. The crystals of cadmium borotungstate thus obtained are freed as much as possible from the mother-liquor by drainage and then melted at about 75° in their own water of crystallization. A liquid is thus obtained on which spinel will float. The same concentration may also be obtained by careful heating on a water-bath. At its highest specific gravity this solution has an oily consistence and this renders its practical use in the separation of fine particles somewhat restricted. By filtering the liquor when a crystalline crust begins to form during evaporation, a cold solution of 3.360–3.365 specific gravity is obtained which is found practically useful. It has a higher specific gravity than Thoulet’s mixture, is not injurious to any of the mineral particles, not even of iron with which it is brought into contact, but the trouble of preparing it is far greater than that of the mixture of mercuric and potassium iodids. =265. Rohrbach’s Solution.=—The solution of barium mercuric iodid recommended by Rohrbach[171] for this purpose was originally prepared by Suchsin. The solution must be rapidly prepared on account of the tendency of the barium salt to decomposition. The solution is prepared by weighing rapidly 100 grams of barium and 130 grams of mercuric iodid, mixing the two salts well in a dry flask and adding twenty cubic centimeters of water. The mixture is raised to a temperature of 150°–200° on an oil-bath. The formation and solution of the double salt are promoted by constant stirring. After solution, the liquor is boiled for a few minutes and then evaporated on a water-bath until it will bear a crystal of epidote. On cooling, a small quantity of a yellow double salt is separated by crystallization and the resulting mother-liquor is dense enough to carry a fragment of topaz. Inasmuch as the liquor is filtered with difficulty, the clear mother-liquor should be separated by decantation after standing for several days. This solution has the disadvantage of not being dilutable with water, the addition of which causes a separation of red mercuric iodid. Were this solution not so easily decomposed, it would prove of high value in silt separation. =266. Braun’s Separating Liquid.=—In many respects the separatory solution proposed by Braun[172] is superior to those already mentioned. It is the commercial methylene iodid, CH₂I₂, which has at 16° a specific gravity of 3.32, at 5° of 3.35, and at 25° of 3.31. It is a strongly refractive liquid having a refractive index of 1.7466 for the yellow ray. As a separating medium the liquid is open to two objections; _viz._, first, it cannot be diluted with water and, second, it turns brown on heating or on long exposure to the sunlight. When dilution is necessary, it should be accomplished with benzene or xylene. To bring the diluted liquor again to its maximum density, the benzene must be removed by evaporation, which causes a considerable loss in the liquid. When this substance becomes opaque, the transparency may be restored by removing the separated iodin by shaking with potash lye, washing with pure water, drying by the addition of pieces of calcium chlorid and filtering. The same result may also be reached by freezing and separating the liquid portion. The frozen portion on melting will have the density of the original liquid. =267. Method of Bréon.=—Instead of a solution of a salt, Bréon[173] has proposed to use salts in a fused state for separating mineral particles. Lead and zinc chlorids may be used for this purpose in a melted state, having the specific gravities of 5.0 and 2.4, respectively. By mixing the molten salts in different proportions, any desired specific gravity between the extremes mentioned may be secured. The fusion is accomplished at 400° in a test-tube. The silt is added gradually with constant stirring until a sharp separation is secured between the sinking and floating particles. After cooling, the tube is broken, the two parts separated, and the silt recovered by dissolving the mixed salts in hot water containing a little nitric acid. Only the coarser silts can be separated by this method. Fused silver nitrate, melting point 198°, specific gravity 4.1, has also been used for separation. =268. The Separation.=—Forty cubic centimeters of the solution in the Thoulet process are placed in the separatory tube A, Fig. 58, together with from one to two grams of the silt and the stopper F inserted. The tube G is connected with a vacuum apparatus by means of which any air particles adhering to the mineral fragments are removed. The silt which sinks in the solution is removed after G has been disconnected by opening the cock C and sucking through B at I. The cock C is closed and the separated particles washed into a beaker at H after opening D. Water is next added to the materials left in A in quantities previously determined to secure a given specific gravity and thus a second, a third, etc., separation secured. An intimate mixture of the solutions in A can be effected by closing D, opening C, and blowing through B in such a way that no liquid is allowed to pass through C. FIG. 58. THOULET’S SEPARATING APPARATUS. ] The quantity of water to be added in each case to secure a given specific gravity is determined by the formula _v_₁ = (_v_(D − _d_))/(_d_ − 1), in which _v_ is the volume of the solution, D its specific gravity, and _d_ and _v_₁ the specific gravity desired and volume of the water to be added. _Example._—Let the specific gravity of the original solution be 3.2, its volume thirty cubic centimeters, and the desired specific gravity of the new solution 2.85. Then _v_₁ = (30(3.2 − 2.85))/(2.85 − 1) = 5.68. The desired specific gravity is therefore secured by adding 5.68 cubic centimeters of water, which is easily accomplished by means of the graduations on the tube. According to Rosenbusch,[174] the calculated specific gravity as made above is not wholly reliable on account of the contraction which takes place. An empirical process is rather to be commended which consists in introducing a fragment of mineral of known or desired specific gravity and then adding water drop by drop until the fragment remains suspended in the mixture. Should too much water be added, the necessary increase in density can be secured by adding a little of the strong solution. =269. Method of Packard.=—A separatory funnel, according to Packard,[175] may be safely used to hold the solution while separation is going on. As the lighter minerals form the bulk of soils, the heavier constituting only a small percentage, it is well to use a wide funnel holding as much as one-half liter for quantitative separations, because a large quantity of soil, say 100 grams, is necessary from which to recover the small quantity of heavy particles satisfactorily. The soil is introduced into the solution contained in the funnel, agitated, stirred with a glass rod, and allowed to stand some time. This operation may be repeated as often as desired. Separation is not absolute by this operation, the heavy and light particles being sometimes so united that they sink or float together according as one or the other preponderates. There are also particles having so nearly the same specific gravity as the solution that they remain indifferent to its action in any position. After separation has been effected, the heavy portion is drawn off through the stop-cock of the funnel and the lighter is skimmed off the top. Both must be thoroughly washed from the adhering heavy solution for further examination with the microscope, and by chemical, microchemical, and blow-pipe tests. One who has familiarized himself with the appearance of minerals in minute fragments under the microscope, in ordinary and polarized light, will be able to determine some minerals in that way. But for certain identification it is necessary to ascertain their optical properties as is done in the case of the minerals in thin sections of rocks. _Illustration._—The following example from the work of Packard will serve to illustrate the results of separating a soil by the specific gravity method: One hundred grams of soil, residual clay from the Trenton limestone, were placed in the Thoulet’s solution contained in the large separatory funnel. The heavy portion, after washing and drying, weighed 0.6886 gram, or 0.69 per cent. Of this, the magnet removed 0.1635 gram, or 0.16 per cent. This heavy material consisted of rounded yellowish and brown grains up to twenty-five millimeters in diameter, mingled with lustrous angular black grains which were seen under the microscope to be cubes with striated faces, cubes penetrating each other and aggregations of cubes. Combinations of cubes with octahedra and instances of the pentagonal dodecahedron were also observed. These forms, characteristic of pyrites, were also seen in the fine sand obtained as a residue on elutriating the same soil. As these crystals dissolved in hydrochloric acid, giving a strong iron solution, they were regarded as pseudomorphs of iron oxid after pyrites. The yellowish grains on treatment with acid left a grayish residue which contained some grains of quartz but was not wholly quartz. The lighter portion of the soil, over ninety-nine per cent, which floated in the Thoulet’s solution of 2.8 was next examined. It was colored red by the iron oxid which coated and adhered to the other minerals. It contained all the quartz, the feldspars if present, and the other minerals whose specific gravity is less than 2.8. It was examined by the microscope and found to consist largely of irregular grains of a mineral which acted on polarized light, obscured somewhat by the iron oxid, and was apparently quartz; and another mineral which was yellowish-brown in color and seemed to be dull and not transparent. Besides there was a large quantity of indistinguishable amorphous material. To clean these minerals the material was treated with hydrochloric acid to remove the iron oxid and other matter soluble in acid, when the quartz grains appeared transparent and gave interference colors in polarized light. But mingled with these were grains of the other mineral which now appeared grayish, dull, and without action on polarized light. The character of this mineral substance could only be determined by chemical analysis. =270. Harada’s Apparatus.=—Although it has been affirmed by some analysts that in the subsidence of small particles it is advisable that the containing vessels have parallel sides, yet in the method just given, and in those about to be described, good results are obtained in a funnel or pear-shaped holder. FIGURE 59. HARADA’S APPARATUS. ] In the apparatus of Harada,[176] Fig. 59, the separating vessel _a_ is made of thick glass furnished with a glass stopper above and a glass stop-cock _h_ below. The separating liquid and silt are placed in the pear-shaped vessel _a_, the stopper inserted, and the whole well-shaken. As soon as a ring of clear liquid is seen between the sinking and floating silt, the lower end of the apparatus is brought near the bottom of a conical glass _b_, the cock _h_ opened and the heavy silt allowed to fall out. Very little of the liquor will flow out because of the air pressure. Should an air bubble enter the apparatus and be held at the stop-cock, it should be made to ascend by gently tapping. When all the heavy silt has passed into the conical glass, the cock _h_ is closed and some water poured over the solution and silt in _b_. The separatory apparatus is now raised until the beveled end of it is in the water layer, when the water at once rises to _h_ and thus washes all the silt particles adhering to the glass into _b_. The liquid in _a_ may then be diluted by inverting the apparatus, adding the required amount of water through _h_, again shaken after closing _h_, and another separation secured as before. This apparatus is somewhat easier to manipulate than Thoulet’s but does not admit of the same quantitative dilution of the separating liquid. FIG. 60 a. FIG. 60 b. FIG. 60 c. BRÖGGER’S APPARATUS. ] =271. Apparatus of Brögger.=—All silt separations in narrow tubes are open to the objection of permitting more or less flocculation. Some of the lighter particles are thus carried down by the heavier, and, on the other hand, some of the heavier float with the lighter. This disturbing action Brögger[177] seeks to avoid by the following device, Fig. 60, a, b, c. The length of the apparatus is forty-six centimeters, and its greatest diameter 3.5 centimeters. The opening in the large stop-cock A is the same diameter as that of the apparatus at that point. The cubical content of the apparatus with A open and B closed is about seventy-five cubic centimeters. In conducting the separation the cock B is closed, the separating liquid and silt introduced, A being open, the stopper K inserted and the whole well-shaken. In the first separation, the silt S, lying over B is contaminated with some of the lighter particles S′₂, while the lighter particles above A, S₂, are mixed with some of the heavier particles, S′₁. After closing A the apparatus is again well-shaken and inverted as in Fig. 60 b. The two parts of the silt will now undergo another separation as indicated. The apparatus is now carefully inclined as in c, when the various grades of silt will flow in the directions indicated by the arrows, but without mixing, passing each other on opposite sides of the apparatus. When the movement is complete, A is carefully opened, the apparatus still being held as in c, and the light silt formerly between A and B will flow above A, while the heavy silt above A will flow down and join the silt collected over B. This operation may be repeated until a perfect separation is effected. Finally B is opened and the heavy silt collected in a beaker, and the lighter silt then removed from the upper part of the apparatus. FIGURE 61. APPARATUS OF WÜLFING. ] =272. Method of Wülfing.=—A somewhat more convenient method of purifying the silt segregates and freeing them of mechanically occluded particles of differing specific gravities has been proposed by Wülfing.[178] An elliptical ring of heavy glass tubing carries glass stop-cocks A and B, Fig. 61, at the two extremities of the ellipse, each arm of which is provided with a lateral glass-stoppered neck. The perforation in the stop-cocks has the same diameter as the sides of the ellipse. The apparatus has an interior cubical content of about forty cubic centimeters. Thirty cubic centimeters of the separating fluid are introduced through one of the lateral apertures and brought to the same height in the two arms by opening the cock B. The silt is then introduced in equal quantities into each of the arms. The stoppers having been inserted, the whole is well-shaken. At the beginning of the separation, the apparatus being held in position 1, the lighter soil above and the heavier soil below are somewhat mixed by reason of flocculation and mechanical entanglement. At this point B is opened and the apparatus placed in the inclined position 2. The heavier particles S + l, on the right arm, are thus united with the same class of particles in the left arm making 2S + 2l. This operation is hastened by opening A and allowing the higher column of liquid in the right arm to pass into the left. The liquid in the left arm is allowed to rise to A. After all of S + l in the right arm has passed into the left B is closed, the apparatus then placed back in position 1 and inclined in the opposite direction until L + s in the top of the left arm has been transferred to the L + s in the top of the right, and the same quantity of liquid is found in each arm. The operation is then repeated and this continued until all S + s is found in the bottom of the left arm and all L + l in the top of the right arm. =273. Separation with a Magnet.=—Particles of magnetic iron oxid are easily separated from the fine soil particles by means of a magnet. A strong bar or horseshoe magnet may be used. Electro-magnets are rarely necessary except for the separation of particles of feeble magnetic power. Particles of iron which may be found would owe their origin to the mortars in which the soil had been pulverized, or they might come from a recently crushed meteorite. Some minerals, as limonite, after ignition are attracted by the magnet and it is advisable to subject a part of the sample to this treatment. The best method of separation consists in spreading the particles evenly on paper and gradually bringing the magnetic particles to one side by moving the magnet underneath. =274. Color and Transparency.=—But little can be learned from the color and transparency of the smallest silt particles, but these properties in the larger grains have considerable diagnostic value. Many minerals of distinct color appear wholly colorless in petrographic sections or in silt particles, as for instance, highly-colored quartz. On the other hand, even the smallest particle of chlorite will show its distinctive tint. The colors in some minerals are due to occluded matter not essential to their structure, and these foreign bodies would naturally escape when the crystal mass is reduced to an almost impalpable powder. =275. Value of Silt Analyses.=—As in the case of chemical analyses a silt analysis of a soil which is not typical or representative has little value. On the other hand, a systematic separation of soils into classes of particles can not fail to reveal a definite correspondence of mechanical composition to soil properties. The production of a crop is the result of certain functions, chief among which are temperature, moisture, and plant food. In a given soil the temperature is markedly affected by its physical state. It has been demonstrated in previous paragraphs that the circulation of moisture in the soil and its capacity to be held therein are chiefly functions of the state of aggregation of the soil itself. The availability of plant food in a soil is not measured by its quantity alone, but rather by its state of subdivision. It is not therefore a matter of surprise that the fertility of a soil is found, _caetèris paribus_, to be commensurate to a certain limit with the percentage of fine silt and clay which it contains. It is true that two soils quite different in fertility, may have approximately the same silt percentages, but in such a case it is demonstrable that even in the poorer soil the measure of fertility is largely the percentage of fine particles and not its actual content of plant food. In other words, almost all soils, even the poorest, have still large quantities of plant food, but these stores, owing to certain physical conditions, are not accessible to the rootlets of plants. An illustration of this is seen in the use of concentrated fertilizers. It might seem absurd to suppose that the addition of 100 pounds of sodium nitrate would prove useful to a plat containing already many tons of nitrogen; but the nitrate is at once available and its beneficial influences are easily seen. The full value of silt analysis will only be appreciated when many typical soils from widely separated areas are carefully studied in respect of their chemical and physical constitution and the character of the crops which they produce. AUTHORITIES CITED IN PART FOURTH. Footnote 121: Annual Report, Connecticut Agricultural Experiment Station, 1887. Footnote 122: American Journal of Science, March 1879, p. 205. Footnote 123: Bulletin, No. 4, United States Weather Bureau, p. 19. Footnote 124: Chemical News, Vol. 30, August 7, 1874, p. 57. Footnote 125: American Journal of Science, Vol. 29, 1885, p. 1. Footnote 126: American Journal of Science, Vol. 37, (1889), p. 122. Footnote 127: Proceedings National Academy of Science, Baltimore Meeting, 1892. Footnote 128: Manuscript communication to author. Footnote 129: Division of Chemistry, Bulletin 38, p. 200. Footnote 130: Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 23. Footnote 131: Die Landwirtschaftlichen Versuchs-Stationen, Band 38, Ss. 309, et seq. Footnote 132: Berichte der deutschen chemischen Gesellschaft, Band 15, S. 3025. Footnote 133: Connecticut Agricultural Experiment Station, Annual Report, 1886, pp. 141, et seq. Footnote 134: König, Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, S. 7. Footnote 135: Wahnschaffe, Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 25. Footnote 136: Vid. 15, S. 24. Footnote 137: König, op. cit. 14, S. 13. Footnote 138: Tenth Census of the United States, Vol. 3, pp. 872–3. Footnote 139: Wahnschaffe, op. cit. 15, S. 26. Footnote 140: Le Stazioni Sperimentali Agrarie Italiane, Vol. 17, pp. 672, et seq. Footnote 141: Vid. 13. Footnote 142: Encyclopedie Chimique, Tome 4, pp. 155, et seq. Footnote 143: Annales de la Science Agronomique, 1891, Tome 1, Seconde Fasicule, pp. 250, et seq. Footnote 144: Vid. 22. Footnote 145: Petermann, L’Analyse du Sol., p. 15. Footnote 146: Vid. 20. Footnote 147: Zeitschrift für analytische Chemie, Band 3, Ss. 89, et seq. Footnote 148: Zeitschrift für analytische Chemie, Band 5, Ss. 295, et seq. Footnote 149: Bulletin de la Société des Naturalistes de Moscou, Tome 40, pp. 324, et seq. Footnote 150: Journal für Landwirtschaft, Band 38, Theil 2, S. 162. Footnote 151: Connecticut Agricultural Experiment Station, Annual Report, 1887, pp. 145, et seq. Footnote 152: Division of Chemistry, Bulletin No. 38, pp. 60, et seq. The figures are from original drawings under the direction of Prof. Hilgard. Footnote 153: Op. cit. supra, pp. 65–69. Footnote 154: Op. cit. 13, p. 150. Footnote 155: Op. cit. 31, p. 152. Footnote 156: Op. cit. 31, p. 157. Footnote 157: Op. cit. 31, p. 159. Footnote 158: Connecticut Agricultural Experiment Station, Annual Report, 1888, p. 154. Footnote 159: Loughridge, Proceedings American Association for the Advancement of Science, Vol. 22, p. 81. Footnote 160: Whitney, United States Weather Bureau, Bulletin No. 4. Footnote 161: Whitney, op. cit. 40. Footnote 162: Vid. 40. Footnote 163: Vid. 40. Footnote 164: Vid. Anleitung zur Mineralogischen Bodenanalyse von Franz Steinreide; and Mikroskopische Physiographie von H. Rosenbusch. Footnote 165: Elemente einer neuen Chemisch-Mikroskopischen Mineral und Gesteinsanalyse, 1877. Footnote 166: Rosenbusch, Mikroskopische Physiographie, Plate 11, Fig. 3. The figures of crystals of potassium, sodium, calcium, magnesium, etc., are taken from the same work, Plates 10, 11, and 12. Footnote 167: Williams, American Journal of Science, February 1893, p. 203. Footnote 168: Op. cit. 46, S. 231. Footnote 169: Op. et., loc. cit. 48. Footnote 170: Op. cit. 46, S. 233. Footnote 171: Op. cit. 46, S. 235. Footnote 172: Op. cit. 46, S. 236. Footnote 173: Op. cit. 46, S. 237. Footnote 174: Op. cit. 46, S. 232. Footnote 175: Manuscript Communication from R. L. Packard. Footnote 176: Op. cit. 46, S. 241. Footnote 177: Op. cit. 46, S. 242. Footnote 178: Op. cit. 46, S. 243. NOTE.—The analyses on page 237 are by Hilgard and Loughridge from Proceedings American Association for the Advancement of Science, Portland Meeting, 1873. PART FIFTH. ESTIMATION OF GASES HELD IN SOILS. =276. Relation of Soil Composition to Gases.=—The power of a soil for occluding gases rests primarily on its composition as determined by silt analysis. The discussion of this part of the subject is so nearly related to that of the physical properties of the soil that it might properly have been included in that part of the work. Since, however, we deal in this part more with the determination of the gas constituents of the soil, it was deemed preferable to place it after the silt analysis and as introductory to the general estimation by more strictly analytical processes of the chemical constituents of the soil. =277. Occurrence of Carbon Dioxid.=—The amount of organic matter in the soil, according to Wollny,[179] is no indication of the quantity of carbon dioxid when the organic matter is in excess. The percentage of carbon dioxid is only proportional to the amount of organic matter when this is in small quantities. Large quantities of organic matter do increase the amount of carbon dioxid, but the increase is not a proportional one, since a larger quantity of this gas in the air of a soil reduces the activity of the organisms which produce oxidation. Water and temperature have a greater influence on the oxidation, and act in an opposite direction to that of the organic matter. The amount of free gas in the soil affords no indication either of the intensity of the action of oxidation or of the amount of organic matter. The addition of liquid manure to the soil results in a reduction of the decomposition of the organic matter when the quantity of the salts therein contained is greater than that already present in the soil. But if the liquid manure is dilute, and the absorptive power of the soil for salts is great, then the decomposition is promoted. =278. Absorption of Aqueous Vapor.=—The power of a soil to resist drought depends largely upon its coefficient of absorption for aqueous vapor. Hilgard has shown[180] that at temperatures between 7° and 21°, the amount of aqueous vapor absorbed by a thin layer of a clay or soil not unusually rich in humus, in a saturated atmosphere, is sensibly constant. In general, clay soils are more absorbent than sandy ones, yet there is no direct connection between the amount of clay present and the absorbent power of the soil. Evidently the hygroscopic coefficient is largely controlled by the presence with the clay of the powdery ingredients which determine its looseness of texture, and it is found that the finer silts themselves possess a considerable absorbing power. According to Whitney this is largely dependent upon the extent of the surface area of the soil grains and upon the size and arrangement of these grains. Again, the presence of hydrated ferric oxid materially influences this power, so that the amount of iron present must always be taken into consideration. =279. Methods of Study.=—The study of the deportment of a soil with vapors or gases may be divided into two general classes. The first depends on the subjection of a sample of soil to the saturating influence of a given vapor or gas and measuring the amount thereof absorbed, either directly by increase of weight, or by the diminution in the amount of gas originally supplied. The maximum absorbent capacity of a soil under given conditions for a gas or vapor is in this way determined. In the second class the determination consists in accurately estimating the amount of gas which is absorbed by a soil in natural conditions or _in situ_, thus giving the natural percentages of the gaseous constituents of the soil. In the first case in general, the principle of the method depends upon the exposure of the soil for a given time under given conditions, to an atmosphere of the gas to be absorbed. The principle of the second class of determinations depends upon the extraction, usually by means of suction, from a given mass of soil of the gaseous matters therein contained. The general details of the methods of procedure for the first class are found in the following directions for manipulation: =280. Determination of the Maximum Hygroscopic Coefficient.=—The fine earth, in Hilgard’s method, is exposed to an atmosphere saturated with moisture for about twelve hours at the ordinary temperature (60° F.) of the cellar in which the box should be kept. The soil is sifted in a layer of about one millimeter thickness upon glazed paper, on a wooden table, and placed in a small water-tight covered box, twelve by nine by eight inches, in which there is about an inch of water; the interior sides and cover of the box should be lined with blotting paper, kept saturated with water, to insure the saturation of the air. Air-dried soil yields results varying from day to day to the extent of as much as thirty to fifty per cent, nor have we any corrective formula that would reduce such observations to absolute measure. Knop’s law, that the absorption varies directly as the temperature, while applicable to low percentages of saturation, is wide of the truth when saturation is approached. The ordinary temperature of cellars will serve well in these determinations without material correction. After eight to twelve hours the earth is transferred as quickly as possible, in the cellar, to a weighed drying tube and weighed. The tube is then placed in a paraffin bath; the temperature gradually raised to 200° C. and kept there twenty to thirty minutes, a current of dry air passing continually through the tube. It is then weighed again and the loss in weight gives the hygroscopic moisture in saturated air. The reason for adopting 200° C. as the temperature for drying instead of 100° is that water will continue to come off from most soils at the latter temperature for an indefinite time, a week or more, before an approach to constancy of weight is attained; and that up to 200° only an arbitrary limit can be assigned for the expulsion of hygroscopic moisture. Moreover, the great majority of soils, especially those poor in humus, will reabsorb moisture from a saturated atmosphere to the full extent of that driven off at 200° C. =281. Estimation of the Absorption Power of Soils for Aqueous Vapors.=[181]—_Method A._—The fine earth, ten to twenty grams, is spread out on a surface of about twenty-five square centimeters, and left for several days with the observation of the temperature of the air and the loss of weight determined from time to time. This evaporation is continued until the weight remains practically constant. Afterwards by drying the sample at 100° the amount of hygroscopic moisture is determined. A similar result can be reached if the sample is first dried at 100°, or over sulfuric acid at ordinary temperatures, and then the increase in weight observed which the sample acquires on being exposed for several days to the atmosphere under ordinary conditions. Soils with about the same content of humus show variations in the power to absorb aqueous vapors which are almost proportional to the amount of clay which they contain. With the increase of humus substance, the power of the soil for absorbing moisture is increased, so that a sandy soil which is rich in humus often will retain as much moisture in an air-dried state as a clay soil which is poor in humus. If the experiment is carried on by drying over sulfuric acid instead of at 100°, the sample should be left from four to seven days in order that a constant weight may be reached. Even after this time the loss in weight is 0.2 to 1.5 per cent less than when the sample is dried at 100°. _Method B._—In order to determine the amount of aqueous vapor which a soil will absorb in an atmosphere saturated with the vapor the following method is used: The sample of air-dried soil in a flat dish of given surface; _viz._, about twenty grams of soil to twenty-five square centimeters surface is placed in a vessel over water without contact with the water, and the whole of the apparatus is covered with a glass bell-jar. The sample is weighed at intervals of six or eight hours until no appreciable increase of weight is observed. An empty vessel of the same size and character as that containing the soil is kept under the bell-jar, also in the same conditions, so that any increase in weight by the deposition of moisture on this vessel may be determined. This increase in weight is to be deducted from the total increase in weight of the vessel and the soil. Sandy and loamy soils become saturated in this manner in the course of the first twenty-four hours and remain after that unchanged in weight. Very clayey soils, and also those which are very rich in humus, require a much longer time, three or four days even. In this case it is better to take a smaller sample of the soil; _viz._, ten grams. The temperature of the air within the glass vessel, of course, must be taken into consideration. _Method C._—The same flat dish and the same quantity of soil as in the other methods are taken in this one. The sample is left out over night where it can be fully saturated with dew. The amount of dew which appears on the bushes should be noted and also the temperature of the air and the percentage of clouds in the sky. An experiment should also be made on spots of earth which are entirely free from vegetation in order that the difference in the amount of water absorbed in places practically devoid of dew and in places where the dew is abundant may be observed. _Method D._—Deeper flat dishes should be used for this determination so that the depth of soil contained in them shall be from one to three, or even six centimeters. The sample of soil should be completely air-dried and in a state of fine subdivision. The vessels containing the soil should be placed in a locality saturated with aqueous vapor or in the open air during the night where they are subjected to the influence of the cooling of the atmosphere and the deposition of dew. Note should be made of the different amounts of moisture absorbed by the layers of earth of different thicknesses in a given time. Observation should also be made of the depth to which the moisture sinks in the sample of soil under consideration. =282. Estimation of the Absorption Power of the Soil for Oxygen and Atmospheric Air.=[182]—From fifty to one hundred grams of air-dried soil are placed in a glass vessel of about 500 cubic centimeters capacity, and the flask closed with a stopper after the addition of enough water to make the percentage of moisture in the soil about twenty. After from eight to fourteen days the air contained in the vessel is analyzed for oxygen, nitrogen, and carbon dioxid, with special reference to the determination of how much oxygen has disappeared and how much the carbon dioxid has been increased. As an alternative method, twenty-five grams of the soil may be moistened with tolerably concentrated potash lye in a small glass vessel, which is itself joined with air-tight connections to an azotometer in which a known volume of air is confined by quicksilver. The glass vessel is frequently shaken during the progress of the experiment. The diminution of the volume of air in the apparatus after from one to four days gives approximately the quantity of oxygen absorbed. =283. General Method of Determining Absorption.=—This method, due to Freiherrn von Dobeneck,[183] is as follows: The soil, in a state of fine powder, is dried at 100° to 105° to a constant weight. It is then placed in an absorption tube of the following construction: The absorption tube consists of a =ᥩ= shaped wide glass tube, both ends of which are supplied with small glass tubes sealed upon the end of the =ᥩ= tube, and those are furnished with tightly-ground glass stop-cocks. Above these stop-cocks these small tubes are bent in opposite directions at right angles. On the bend of the =ᥩ= is sealed another tube which is furnished with a ground glass stopper. Through this opening the =ᥩ= tube can be filled with the sample of soil. When the tube is filled, the glass stopper inserted, and the two stop-cocks on the small tubes closed, the contents of the tube are completely excluded from the external atmosphere. Many of these tubes can be used at once so as to hasten the progress of the work. The tubes after being filled are placed in a drying oven with the stop-cocks open. The stop-cocks are then closed before the tubes are removed, when they are placed in a desiccator for cooling preparatory to weighing. The weighed tubes are held in a tin box which can be placed in a water-bath which is kept at a given temperature by means of a thermostat. The top of the tin box should be hinged and made of a thick non-conducting material so as to prevent any rapid change of temperature within. On the inner side of the box a small thin-walled glass tube is carried around four times. One end of this tube passes through an opening in the side of the box by means of which it can be connected with the gas apparatus outside. The other end of it is connected directly with the absorption tubes. The absorption tubes are so connected among themselves that when ammonia or carbon dioxid is employed the gas passes through one of the tubes before it can reach the next, and so on. For experiments with water-gas, however, that is, air charged with aqueous vapor, the arrangement must be different. While in the case of ammonia and carbon dioxid the composition of the gas is not changed by passing through the samples of soil, the case is quite different when air charged with aqueous vapor passes through. In the latter case the amount of aqueous vapor in the air would be notably lessened in passing from sample to sample on account of the retention of a part of the aqueous vapor by the soil. In this case, therefore, the saturated air, after it has passed through the glass tube around the inside of the box in order to reach the proper temperature, is conducted into a receptacle of glass which has a number of connections equal to the number of absorption tubes so that the saturated air can pass directly into each one of them. The gases which are to be used for the experiments are prepared in proper apparatus and are forced through the samples of soil, either by pressure as in the case of ammonia or carbon dioxid, or by means of aspirators as in the case of air saturated with aqueous vapor. The carbon dioxid employed is purified by passing over sodium carbonate and calcium chlorid. The ammonia is prepared by the action of finely powdered lime on ammonium chlorid, and is dried by passing over lime and sticks of potassium hydroxid. The air which is to be saturated with aqueous vapor, in order to purify it from dust, carbon dioxid, and ammonia, is passed through two flasks in which are contained respectively, diluted sulfuric acid and potash lye. It is afterwards thoroughly saturated with aqueous vapor at the temperature desired. Various kinds of soil material may be employed as follows: (1) Pure quartz sand.—Freed from all fine particles by subjection to silt analysis, afterwards boiled with hydrochloric acid and washed with water to free it from all clayey materials. The sand prepared in this way should be passed through different sieves in order to prepare it in different states of fineness. (2) Quartz powder.—Prepared from pure quartz crystals by grinding in an iron mortar. (3) Kaolin.—Material such as is used in the manufacture of the finest porcelain which, after being freed of all foreign matter, is rubbed to a fine powder in a porcelain mortar. (4) Humus.—Washed with ether and alcohol, boiled with hydrochloric acid, washed, dried and reduced to a state of fine powder. (5) Iron oxid. (6) Calcium carbonate.—Precipitated, washed, and dried. (7) Soil mixtures.—Prepared artificially by mixing the kaolin, quartz, and humus, above mentioned. The quantity of gas absorbed by each of these materials is determined by filling the tubes, as above mentioned, with the dried material. The content of each tube is previously determined by filling with mercury and weighing. Having determined the weight of the substance to the exclusion of the air contained within its pores, it is treated with the gas in the apparatus described above and weighed from time to time until no further increase of weight takes place. The method of calculating the results is shown in the following scheme: V = content of the absorption tube obtained by filling with mercury and weighing. P′ = weight of the empty tube filled with air at 100°. pl = weight of the air in the tube (pl = V × specific gravity of the air at 100°). pt′ = weight of the tube (pt′ = P′ − pl). P² (second weighing) = weight of the tube filled with the substance with the included air at 100°. v^s = volume of the substance calculated according to the formula v^s = (P² − P′)/(s^s − specific gravity of air). s^s = specific gravity of the substance. vl = volume of the air in the flask filled with the substance (vl = V − v^s). pl′ (weight of this included air) = vl × specific gravity. p^s = weight of the substance (pl = p² − pt′ − pl) P³ = weight of the apparatus at the end of the experiment. sg = specific gravity of the gas employed for saturation. pg (weight of the gas remaining over the substance) = vl × sg. pa (weight of the absorbed gas) = P³ − pt′ − p^s − pg. p^s gram of substance absorbs pa gram of the gas and 100 grams of substance would absorb (100 × pa)/(p^s) grams. The specific gravities of the gases employed are calculated from the tables given by Landolt and Börnstein in “Physical and Chemical Tables,” page 5. The specific gravity of the quartz sand employed was 2.639; of the quartz powder, 2.622; of the kaolin, 2.503; of the humus, 1.462; of the iron hydroxid, 3.728; and of the calcium carbonate, 2.678. One liter of ammonia, at a pressure of 760 millimeters of mercury and a temperature of 0°, weighs 0.7616 gram; one liter of carbon dioxid, 1.9781 grams; one liter of aqueous vapor, 0.8064 gram; and one liter of dried air, 1.2931 grams. At a pressure of 720 millimeters, and at 20° temperature, a liter of air saturated with aqueous vapor at 0° weighs 1.1383 grams; saturated at 8.6°, 1.1362 grams; saturated at 10°, 1.1358 grams; saturated at 14°, 1.1340 grams; saturated at 18.2°, 1.1330 grams; saturated at 20°, 1.1321 grams; saturated at 30°, 1.1313 grams. The general results of the experiments are as follows: ABSORPTION AT 0°. Aqueous vapor Ammonia. Carbon dioxid. from saturated air. Grams. Cubic Grams. Cubic Grams. Cubic cm.[H] cm.[H] cm.[H] 100 grams quartz 0.159 197 0.107 145 0.023 12 „ „ kaolin 2.558 3,172 0.721 947 0.329 166 „ „ humus 15.904 19,722 18.452 24,228 2.501 1,263 „ „ Fe₂(OH)₆ 15.512 19,236 4.004 5,275 6.975 3,526 „ „ CaCO₃ 0.224 278 0.256 320 0.028 14 Footnote H: Reduced to 0° and 760 millimeters pressure mercury. The foregoing methods will suffice to show the procedures to be followed in estimating the maximum amount of any common gas or vapor a given quantity of soil may be made to absorb. We pass next to consider the quantities of gases or vapor soils _in situ_ may hold. =284. Method of Boussingault and Lewey.=[184]—This method is the oldest and most simple procedure for estimating the nature of the gases held in a soil _in situ_. For the purpose of collecting the sample of gas from the soil a hole, thirty to forty centimeters in depth, is dug, and a tube placed in it in a vertical position, having on its lower extremity a bulb perforated with fine holes. The hole is filled and the earth closely packed around the tube which is left for twenty-four hours. At the end of that time the tube is slowly aspirated until a volume of gas approaching from five to ten liters is obtained. _Estimation of Carbon Dioxid._—The carbon dioxid in the sample of gas is estimated by allowing it to bubble through a solution of barium hydroxid. _Estimation of the Oxygen._—The oxygen is estimated in a separate sample of the gas by means of potassium pyrogallate. The chief objection to this simple process is the uncertainty of being able to obtain an average sample of the occluded gas. In digging the hole and refilling, there must evidently be a considerable disturbance of the original distribution of the gas or vapor. The methods of Pettenkofer[185] and Aubry[186] are essentially like that just described. Pettenkofer found the largest quantities of carbon dioxid in the earth gases in July, August, and September, and the smallest quantities in the winter months. No greater detail concerning these methods of the direct aspiration of the air is considered necessary inasmuch as the methods about to be described, while more elaborate, are superior in accuracy to the older methods mentioned. In general, in these experiments, it is deemed sufficient to determine the carbon dioxid only. FIGURE 62. SCHLOESING’S SOIL-TUBE FOR COLLECTING GASES. ] =285. Method of Schloesing.=—The apparatus used by Schloesing[187] in the collection of the soil gases consists of a steel tube (Fig. 62) a little over one meter in length, ten millimeters in external diameter, and one and one-half to two millimeters in internal diameter. The end which penetrates the soil is made slightly conical for a distance of twenty-five to thirty centimeters. By reason of the shape of the tube, when it is driven into the soil all connection between the orifice in the point of the tube and the external air is prevented. The obstruction of the internal canal of the tube is prevented by introducing a thread of steel which penetrates the whole length of the tube. This thread, represented by A, B, C, D, is flush with the interior extremity of the tube at D. It extends for about three centimeters above the upper end of the tube in order to be easily handled when it is to be removed. For the purpose of driving the tube into the soil its upper part is covered with a cylindrical piece of steel, EF, in the interior of which are freely engaged H and A. This head piece rests upon a ring of steel, K. This ring is fastened solidly into the tube. On striking the piece EF the tube and the steel wire in the center are driven together into the soil. The tube is flattened at L and L′ in order to be embraced by the key MM, the employment of which is necessary in order to revolve the tube around its axis when it is being driven into the soil. When the tube has been driven to the depth desired, the steel wire is withdrawn and it is immediately connected at H with the rubber tube N (Fig. 63) belonging to the system PQT, and furnished with a pinch-cock X. The system PQT comprises the following elements: PQT made of a capillary glass tube in the form of a T. The lower end of the tube P is closed by the larger glass tube O, sealing the end of P with a little mercury. O is held to P by the cork S, which is attached firmly enough to prevent O from dropping off, but is furnished with a canal in order to allow the air to flow in or out freely. This system is connected with the system UV by the rubber connection T. U is a glass vessel having the constrictions as indicated in its stem above and below the bulb. V is a glass vessel of convenient size connected with U by the rubber tubing as indicated. The capacity of the cylindrical portion of U should be from fifteen to eighteen cubic centimeters. FIGURE 63. SCHLOESING’S APPARATUS FOR COLLECTING GASES FROM SOIL. ] To take a sample of soil gas, V is lifted above U. The air is driven from U and escapes through O, which acts as a true valve. When the mercury has completely filled U the pinch-cock X is opened and V depressed gradually. The gas coming from the soil is thus collected in U. A few cubic centimeters of the soil gas are collected in this way, the pinch-cock X is again closed and V is raised in order to drive the whole of the contents of U again through O. In this way the whole of the air which the capillary vessel originally contained is removed and all parts of it remain filled with soil gas. Two or three operations, using from five to ten centimeters of soil gas in all, will be sufficient to completely free the apparatus from its original content of air. U is then entirely filled by depressing V, and it is then hermetically sealed at the two constricted points by means of an alcohol lamp. The sealed tube can then be transported to the laboratory and its contents subjected to eudiometric analysis. Without displacing the tube from the soil, several samples of gas can be taken from the same spot. A sufficient number of the bulbs V should be at hand to hold the required number of samples. Instead of submitting the sample to eudiometric analysis it is usually sufficient to determine the quantity of carbon dioxid which it contains, inasmuch as numerous experiments have shown that in 100 parts of soil gas the oxygen and carbon dioxid together constitute twenty-one parts. No appreciable trace of marsh gas, or other combustible gas, has yet been detected in ordinary arable soils. These gases have only been found in special soils from marshes, in the neighborhood of gas wells, etc., and not in arable soils. FIGURE 64. SCHLOESING’S APPARATUS FOR DETERMINATION OF CARBON DIOXID. ] =286. Apparatus for Estimating the Carbon Dioxid.=—The apparatus used for determining the carbon dioxid in Schloesing’s work consists of the apparatus shown in Fig. 64. A represents a glass vessel surrounded by a jacket of glass, full of water, and sealed on its lower part to the tube BC of about six millimeters internal diameter. On its upper part it is sealed to the capillary tube D. The tube BC is graduated from C in hundredths of the volume of DAC, which volume is about twelve cubic centimeters. On its lower part it is connected by a rubber tube with a reservoir F which is capable of being raised or lowered. GHK are capillary tubes connected together by the rubber tubes L and M, which are furnished with pinch-cocks. The tube G is connected to a vacuum by the rubber tube N. The rubber tube should be of very small internal diameter and from forty to fifty centimeters in length. To the tube H are sealed, at right angles, the branch D and another branch O. This last dips into a little mercury which the tube P contains. It serves as a valve, permitting the exit of the gases but not their entrance. The tube K carries some lines engraved on its inferior part and is sealed to the system of the two bulbs Q and R. The bulb Q contains a concentrated solution of potash. It carries a number of pieces of glass tubing for the purpose of increasing the surface of the potash solution. All the parts of the apparatus are fixed upon a rectangular board, nineteen centimeters broad by twenty centimeters long. This forms one of the faces of a wooden box to which it is hinged and which serves for the transportation of the apparatus in a vertical position. The graduation of the tube BC is recorded behind this tube upon a card fixed upon the board. By means of these two graduations, the height of the mercury in the tube BC is most easily read, even when the tube is not perfectly vertical. Each one of the pinch-cocks L and M, on its upper part is fixed in a sort of guard which prevents it from being displaced laterally during the processes of the manipulation, thus avoiding all danger of breakage. After the operation is finished a little air is sent into Q in such a manner as to sensibly lower the level of the solution of potash, and the upper extremity of R is closed with a rubber stopper. Afterward, the apparatus can be transported without any danger of the potash becoming engaged in the tube K and reaching the measuring tank A. To proceed to the analysis, a stake is driven into the soil to which all of the apparatus can be fixed. At the side of the stake the apparatus for taking the sample, already described, is driven into the soil and this apparatus is connected by the tube N with the apparatus for determining the carbon dioxid. The pinch-cocks L and M being closed, F is lifted until the mercury which runs from it fills A and approaches D. During this time the air which the apparatus contains has been driven out through O. The tube NGD is freed from air by opening the pinch-cock L, lowering F and drawing into A the gas coming from the soil; afterward closing L and driving out the gas through O. After two or three rinsings of this kind, which employ altogether only ten to twelve cubic centimeters, the gas which is to be analyzed is sucked into A. For this purpose F is lowered until the mercury in the tube BC is very near C. The pinch-cock L is closed and M opened. The reservoir F is displaced little by little by pressing lightly against the rectangular board in order to give it greater firmness in such a way as to fix the level of the mercury exactly at C, and the line is noticed where the solution of potash in K stands. The gas contained in the apparatus is under a pressure, the difference of which from the external pressure is represented by the column of the potash solution between the mark just noticed and the level of the same solution in the bulb R. In order to absorb the carbon dioxid, F is lifted until the mercury stands between D and E. The gas thus passes from A into Q. It gives up immediately its carbon dioxid to the potash solution. It is then made to come again into A, and afterward a second time into Q in order to free it from the last trace of dioxid. Finally it is made to return to A and F is kept at such a height that the potash solution maintains in the tube K the same level as at the commencement of the operation. The gas is then at the same pressure to which it was subjected before absorption. The level of the mercury is then read on BC. At the time the apparatus is used, the measuring tube A should be slightly moist. If it is not so, a small quantity of water should be introduced which is afterward rejected, but which leaves a sufficient quantity of moisture upon the internal walls of A. In this way the gas will always, before or after absorption of carbon dioxid, be saturated with vapor of water, and the figure read in the last place upon the tube BC represents the percentage of carbon dioxid in 100 parts of the gas extracted from the soil supposed to be saturated with vapor at the temperature of the experiment. During the course of the analysis, the temperature of the measuring flask, which is almost entirely surrounded with water, does not vary sensibly, but in a series of experiments which are executed at different times, the temperature of the measuring apparatus, which is that of the ambient air, may change much. It may oscillate between 10° to 25°, and exceptionally between 0° and 30°, whence there are notable variations in the tension of the vapor of the gas measured. If it should be desired to calculate to 100 parts of dry gas the observations made at 30° upon 100 parts of saturated gas, it would be necessary to increase the percentage of carbon dioxid by about ¹⁄₂₅ of its value. It is noticed that with the apparatus described above, the gas upon which the estimation is really conducted comprises not only that which the measuring apparatus contains from E to C before the absorption of the carbon dioxid, but also the small quantity which remains in the capillary tube KME at the moment when closing the pinch-cock M, after the second rinsing, the gas from the soil is aspired into EAC. On the other hand, there is left in the same tube KME, when the final reading is made, some gas which belongs to that which has been measured at the end. These two small gaseous portions which we consider in the tube KME to be sensibly equal, do not contain any carbon dioxid and may be left out of consideration. That is why the volume of the measuring apparatus is limited to E and the graduation of the tube BC is in hundredths of the volume comprised from E to C. In reality the two portions are not absolutely equal because the two successive levels of the potash solution, which limit them in the tube K, are not absolutely identical. These two levels can differ in such a manner as to correspond to a volume of about ¹⁄₁₀₀₀ of the measuring apparatus. Thus the estimation is really made upon a volume of gas which may be greater or less by ¹⁄₁₀₀₀ than the volume of EAC; whence there might result an error of ¹⁄₁₀₀₀ in the estimation of the carbon dioxid, an error which is wholly negligible. As a result of numerous analyses it is concluded, first, that the oxygen exists normally in the atmosphere of soils in large proportion; second, very probably the gaseous atmosphere of arable soils, to a depth of sixty centimeters, contains scarcely one per cent of carbon dioxid and about twenty per cent of oxygen; third, the highest percentages of carbon dioxid correspond to epochs of highest temperature and periods of greatest calm; fourth, the proportion of carbon dioxid increases ordinarily with the depth at which the samples are taken. This disposition of the carbon dioxid would appear almost necessary, since near the surface the internal atmosphere is almost constantly diluted by external air by virtue of diffusion. Fifth, from one epoch to another the composition of the atmosphere of the soil can undergo considerable variation. =287. Determination of Diffusion of Carbon Dioxid in Soil.=—The method proposed by Hannén[188] is a convenient one to use in studying the rate of diffusion of carbon dioxid in soils. A large Woulff’s bottle with three necks serves for the reception of the gas. The two smaller outer necks of the bottle carry two glass tubes bent outwards and provided with stop-cocks. One of these passes to near the bottom of the bottle and the other just through the stopper. The middle tubule of the bottle is of a size to give in section an area of about twenty-two square centimeters. It is made with a heavy rim two centimeters wide and plane ground. This rim carries a plane-ground glass plate with a circular perforation in one-half of it, of the size of the opening in the central tubule of the bottle. A glass cylinder, carrying a fine wire-gauze diaphragm near the lower end, fits with a ground-glass edge air-tight, over this aperture, being held in position by a brass clamp. The ground-glass plate moves air-tight between the cylinder and the bottle, so that the cylinder can be brought into connection with the bottle or cut off therefrom without in any way opening the bottle to the air. The plate and all ground movable surfaces should be well lubricated with vaseline. The experiment is carried on as follows: The glass cylinder is filled with the soil to be tested, closed above with a rubber stopper carrying a gas tube, and then by moving the perforated-glass plate brought into connection with the bottle. The side tube, with short arm inside the bottle, is then closed, and carbon dioxid introduced through the other lateral tube until the gas passing from the tube at the top of the cylinder is pure carbon dioxid. The lateral tube is then closed and the bottle is placed in a water-bath and kept at a constant temperature of 20°. When the temperature within and without the apparatus is the same the reading of the barometer is made, the stopper removed from the top of the cylinder, and the process of diffusion allowed to begin. After from six to ten hours the glass plate is moved so as to break the connection between the cylinder and bottle. The carbon dioxid remaining in the bottle is driven out by a stream of dry, pure air. The air is allowed to pass through the apparatus for about ten hours. The carbon dioxid driven out is collected in an absorption apparatus and weighed. The absorption apparatus should consist of a series of Geissler potash absorption bulbs and finally a =ᥩ= form soda-lime tube. In front of the absorption apparatus is placed a drying bulb containing sulfuric acid. Inasmuch as the temperature and pressure can be readily determined, the weight of carbon dioxid obtained is easily calculated to volume. The weight of 1,000 cubic centimeters of carbon dioxid at 0° and 760 millimeters pressure is 1.96503 grams. Therefore one milligram is equivalent to 0.5089 cubic centimeter of the gas. The volume of the bottle should be carefully determined by calibration with water. The results should be calculated to cubic centimeters per square centimeter of exposed surface in ten hours. The depth of the soil layer is conveniently taken at twenty centimeters. =288. Statement of Results.=— THE SOIL PACKED LOOSELY IN THE DIFFUSION TUBE. DIFFUSION TIME, TEN HOURS. Diameter of Weight of Pure carbon Carbon dioxid Cubic soil soil taken, dioxid at at end of centimeters particles, grams. beginning of experiment, of carbon millimeters. experiment, cubic cm. dioxid cubic cm. diffused for each square cm. 0.01–0.071 520 2549.4 1230.3 59.9 0.071–0.114 550 2545.9 1269.2 58.0 0.114–0.171 590 2556.4 1354.2 54.6 0.171–0.250 620 2538.9 1336.1 54.6 0.250–0.500 660 2532.0 1374.5 52.6 0.500–1.000 680 2528.2 1440.2 49.5 1.000–2.000 690 2496.6 1396.9 50.0 Mixture of 720 2514.3 1572.5 42.8 the above In greater detail the calculation and statement of the results may be illustrated by the following data: In the first experiment given in the above table the diameter of the soil particles varied from 0.010 to 0.071 millimeter. The weight of soil in the diffusion tube was 520 grams. The volume of gas, at 0° and 760 millimeters, before the diffusion began was 2549.4 cubic centimeters. The volume of carbon dioxid under standard conditions remaining after ten hours of diffusion was 1230.3 cubic centimeters. This volume is calculated from the weight of carbon dioxid obtained in the potash bulbs, each milligram being equal to 0.5089 cubic centimeter of carbon dioxid. The volume of carbon dioxid diffused is therefore 2549.4 − 1230.3 = 1319.1 cubic centimeters. The per cent of carbon dioxid diffused is 1319.1 ÷ 2549.4 = 51.74. The volume of carbon dioxid diffused for each square centimeter of cross section of the diffusion tube is 1319.1 ÷ 22 = 59.9 cubic centimeters. The carbon dioxid should be passed long enough to secure complete expulsion of the air before the determination is commenced. =289. General Conclusions.=—The general results of the experiments with the diffusion apparatus to determine the effect of the physical condition of the soil upon the rate of diffusion are as follows: 1. The diffusion of carbon dioxid through the soil is, at a constant temperature, chiefly dependent upon the pores in the cross section of the column of soil. Therefore, the absolute quantity of the diffused gas is greater the larger the total volume of the pores and _vice versa_. 2. Every diminution of the volume of the pores, whether secured by pressure of the soil or by an increase in the moisture thereof, is followed by a decrease in the volume of diffused gas. The giving up of the carbon dioxid present in the soil atmosphere to the upper atmosphere by the method of diffusion is therefore the less the finer the soil is, the more compressed the soil particles are, and the larger the water capacity of the sample and _vice versa_. 3. The quantity of diffused carbon dioxid is diminished according to the measure of compression to which the soil is subjected but is not strictly proportional to the height of the soil layer. 4. In soils in which rain water percolates slowly the diffusion of the carbon dioxid on account of this property is depressed to a greater or less extent. AUTHORITIES CITED IN PART FIFTH. Footnote 179: Proceedings of the American Association for the Advancement of Science, 1872, p. 328. Footnote 180: Die Landwirtschaftlichen Versuchs-Stationen, 1889, S. 197. Footnote 181: König, Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, Ss. 64–66. Footnote 182: König, op cit. supra. Footnote 183: Forschungen auf dem Gebiete der Agricultur-Physik, Band 15, S. 190. Footnote 184: Annales de Chimie et de Physique, Tome 37, 1853; Encyclopedie Chimique, Tome 4, p. 154. Footnote 185: Zeitschrift für Biologie, Band 7, S. 395 and Band 9, S. 250. Footnote 186: Jahresbericht für Agriculturchemie, Band 1, S. 160. Footnote 187: Annales de Chimie et de Physique, 1891, Sixième Série, Tome 23, pp. 362, et seq. Footnote 188: Op. cit. 5, 1892, Ss. 8, et seq. PART SIXTH. =290. Preliminary Considerations.=—The sample of soil intended for chemical analysis should consist of the fine earth which has passed at least a one-millimeter mesh sieve and subsequently been completely air-dried. According to Petermann the air-drying of a soil should continue for about four days for an ordinary arable soil, and about six days for one very rich in organic matter. With peat and muck soils I have found that ten or twelve days with frequent stirring, even when in thin layers, are necessary to attain approximately a constant weight. The soil is conveniently spread on a zinc or other metal sheet of sufficient area so that the layer will be only one or two centimeters in thickness. The weight before and after desiccation will give the percentage of moisture lost on air-drying, which, of course, will depend chiefly on the degree of saturation of the sample when taken and the atmospheric conditions prevailing during drying. If samples of soil are taken in very dry times it is often necessary to moisten them with distilled water in order to prepare them properly for air-drying. The quantity of hygroscopic water which the sample loses at 100°–105° should be determined, and all subsequent calculations of the percentages of the various constituents be based on the water-free material. When a soil which has been dried at 100°–105° to a constant weight is heated to 140°–150° it loses additional weight not due to loss of water of constitution. A part of this loss may be due to hygroscopic moisture which is not given off at 100°–105°, and a part may be hydrocarbons, or other easily volatile organic or inorganic bodies. Before estimating the total loss on ignition it is recommended by most chemists to dry at 140°–150°. The samples of soil, however, intended for chemical examination should never be dried beyond the point which is reached by exposure in thin layers at ordinary room temperatures. The state of aggregation, degree of solubility, and general properties of a soil, may be so changed by absolute desiccation as to render the subsequent results of chemical investigation misleading. In the methods which follow the actual processes employed have been given, which in some instances transgress the general principle stated above, but in all cases standard and approved methods are given in detail, even if some of their provisions seem unnecessary or imperfect. =291. Order of Examination.=—First of all in a chemical study of the soil should be determined, its reaction (with litmus), its water-holding power in the air-dried state (hygroscopicity), its content of combined water (giving hydrous silicates of alumina), its organic matter (humus and organic nitrogen), its content of carbon dioxid (carbonates of the alkaline earths), and the part of it soluble in acids. A determination of these values gives the analyst a general view of the type of soil with which he is engaged, and leads him to adopt such a method of more extended analysis as the circumstances of the case may demand. For this reason those operations which relate to the above determinations are placed first in the processes to be performed, while the estimation of the more particular ingredients of the soil is left for subsequent elaboration. Next follows a description of the standard methods of estimating the more important elements passing into solution on treatment of a soil sample with an acid. The method of treating the insoluble residue, and the detection and estimation of rare or unimportant soil constituents, closes the analytical study of the soils. With respect to the determination of nitrogen as nitric or nitrous acid in the soil and drainage waters, it has been thought proper to collect all standard methods relating particularly thereto into one group, and they will appear separate from the methods under nitrogen analysis in fertilizers. The question of the utility of chemical soil analyses is one which has been the subject of vigorous discussion, a discussion which finds no proper place in a work of this character. Unless, however, intelligent soil analysis be productive of some good it would be a thankless task to collect and arrange the details of the processes employed. An accurate determination of the constituents of a soil may not enable the chemist to recommend a proper course of treatment, but it will help in many ways to develop a rational soil diagnosis which will permit the physician in charge of the case, who last of all is the farmer, to follow a rational treatment which in the end will be productive of good. The analyst will find in the methods given all that are approved by bodies of official or affiliated chemists, or by individual experience, and among them some method may be found which, it is hoped, will be suited, in the light of our present knowledge, to each case which may arise. =292. Reaction of the Soil.=—In soils rich in decaying vegetable matter the excess of acid is often great enough to produce a distinct acid reaction. On the contrary, in arid regions the accumulation of salts near the surface may produce the opposite effect. The reaction of the soil may be determined with a large number of indicators among which, for convenience, sensitive litmus paper, both red and blue, stand in the front rank. A sample of the soil, from fifteen to thirty grams, is mixed with water to a paste and allowed to settle. The litmus paper is then dipped into the supernatant liquid. =293. Determination of Water in Soil.=—The following problems are presented: (a) _The Determination of Water in Fresh Samples taken in situ._—The content of water in this case varies with the date and amount of rain-fall, the capacity of the soil for holding water, the temperature and degree of saturation of the atmosphere, and many other conditions, all of which should be noted at the time the samples are taken. (b) _The Determination of Water in Air-Dried Samples._—In this case the soil is allowed to remain in thin layers, and exposed to the air until it ceases to lose weight. The quantity of water left is dependent on the capacity of the soil to hold hygroscopic water and to the temperature and degree of saturation of the air. (c) _The Determination of the Total Water by Ignition._—This process not only gives the free and hygroscopic moisture, but also combined water present in the hydrous silicates and otherwise. The estimation is complicated by the presence of carbonates and organic matter. =294. Determination of Water in Fresh Samples.=—This determination requires that the sample, when taken in the field, should be so secured as to be weighed before any loss of moisture can take place. For this purpose it can be sealed up in tubes or bottles and preserved for examination in the laboratory. According to Whitney, the relations of soils to moisture and heat are such prominent factors in the distribution and development of agricultural crops, that the determination of the actual moisture content of soils in the fields should be considered a necessary part of the meteorological observations, and of far more importance, indeed, or having far more meaning to the agriculturist than the simple record of the rain-fall. In order to determine the relation of the soil to moisture, uninfluenced by the varying conditions of cultivation and of the different size of crop, he recommends that a small plot of ground be reserved at each station, adjacent to the soil thermometers, where the samples may be taken for the moisture determinations. No crops should be allowed to grow on this area and the soil is not to be disturbed, except that weeds and grass are carefully removed by hand when necessary. Samples of the soil should be taken every morning at 8 o’clock, by correspondents in the principal soil formations from the different parts of the area under observation, and sent by mail to the laboratory. The samples should be taken as described in paragraph =65=. The locality and date are written on a label attached to the tube. The tube contains about sixty or seventy grams of soil, and the moisture determination is made on this in the laboratory in the usual way. It would be desirable to have this sample represent a depth of from six to nine inches, thus rejecting the surface three inches which are more liable to sudden and accidental changes. These tubes are very inexpensive, and a sufficient number should be purchased to keep each station supplied. The sample represents a definite depth, and it does not have to be subsampled or even transferred in the field. This record of the moisture of the soil will show the amount of moisture which the different soils can maintain at the disposal of the plants, which, together with the temperature of the soil, is believed to be a most important factor in crop distribution and development. =295. Method of Berthelot and André.=—The estimation of the water according to Berthelot and André[189] should be made under three forms; _viz._, 1. Water eliminated spontaneously at ordinary temperatures. 2. Water eliminated by drying to constant weight at 110°. 3. Water eliminated at a red heat. The water may be determined directly on a sample weighed at the time of taking and afterwards dried in the open air, and finally, if necessary, in a desiccator. For a general idea the desiccation should be made on a sample of 100 grams, for exact work on ten grams. The dish in which the drying takes place should be shallow, and during the time the sample should be frequently stirred and thoroughly pulverized with a spatula which is weighed with the dish. The drying in the air should continue several days. The data obtained are not fixed since they depend on the temperature and the degree of saturation of the air with aqueous vapor. The variations due to these causes, however, are not very wide. The process may be regarded as practically finished when successive weights sensibly constant are obtained. In this state the soils contain very little water eliminable at 110°. =296. Estimation of Water Remaining after Air-Drying.=—The sifted sample is placed in quantities of five or ten grams in a flat-bottomed dish and dried at 110° to constant weight. This treatment not only removes the moisture, but all matters volatile at that temperature. Petermann,[190] in the Agricultural Station, at Gembloux, practices drying the sample to constant weight at 150°. It is further recommended by Petermann to determine total volatile and combustible matters by igniting to incipient redness, allowing to cool, moistening with distilled water, and drying at 150°. The German experiment stations[3] estimate hygroscopic moisture for analytical calculations by drying to constant weight at 100°. In determining loss on ignition, however, the preliminary drying is made at 140°, with the exception of peaty samples where so high a temperature is not admissible. The Official Agricultural Chemists[191] place five grams of air-dried soil in a flat-bottomed and tared platinum dish; heat in an air-bath to 110° for eight hours; cool in a desiccator, and weigh; repeat the heating, cooling, and weighing, at intervals of an hour till constant weight is found, and estimate the hygroscopic moisture by the loss of weight. Weigh rapidly to avoid absorption of moisture from the air. In the German laboratories, according to König,[192] from ten to twenty grams of the fine earth, properly prepared by air-drying and sifting, for analysis, are heated at 100° to constant weight. For control, five grams are placed in a desiccator over sulfuric acid for two or three days. Wolff directs that a small portion of the well-mixed earth, for example, twenty grams, be spread out on a flat zinc plate, and its changes in weight observed through several days. These observations are continued until the variations are so slight that the means can be determined with sufficient exactness from the last weighings. The soil is then dried at 125° in a hot air-chamber. The loss in weight will give the mean hygroscopic moisture in the soil under the conditions in which the experiment is made. =297. Drying in a Desiccator.=—The sample dried as indicated previously by the method of Berthelot and André is placed in a desiccator over sulfuric acid. It is better to have the sample traversed by a current of perfectly dry air, and in this case it should be placed in a tube, which is closed while weighing, to prevent absorption of moisture. Much time is also required for this operation, and it does not possess the practical value of the method of drying in the free air. =298. Water Set Free at 110°.=—This is determined by Berthelot and André on a weight of five to ten grams of soil. The sample which has been employed for the preceding determination may be used. While this is going on in an air-bath heated to 110°, about ten times as much soil should be dried for the same time at the same temperature, and this should be preserved in a well-stoppered flask. All subsequent determinations are to be made with the soil dried at 110°. The loss of weight in a soil increases with the temperature to which it is exposed. The apparent quantity of water, therefore, determined at 140° or 180° is always greater than that obtained at 110°. But when the temperature exceeds 110° there is danger of decomposing organic bodies with the loss of a part of their constituent elements. Carbon dioxid and ammonia may also be lost, as well as acetic acid and other volatile bodies. =299. Loss on Ignition.=—The loss on ignition represents any hygroscopic moisture not removed by previous drying, all water in combination with mineral matters as water of constitution, all organic acids and ammoniacal compounds, all organic matter when the ignition is continued until the carbon is burned away, all or nearly all of the carbon dioxid present in carbonates, and, finally, some of the chlorids of the alkalies, if the temperature have been carried too high or been continued too long. The loss of carbon dioxid in carbonates may be mostly restored by moistening the ignited mass two or three times with ammonium carbonate, followed by gentle ignition for a few minutes to incipient redness, to remove excess of the reagent. The apportionment of the rest of the loss justly among the remaining volatile constituents of the original sample is a matter of some difficulty but may be approximately effected by the methods to be submitted. =300. Determination of Loss on Ignition.=—_Method of the Official Agricultural Chemists._ The platinum crucible and five grams of soil used to determine the hygroscopic moisture may be employed to determine the volatile matter. Heat the crucible and dry soil to low redness. The heating should be prolonged till all organic material is burned away, but below the temperature at which alkaline chlorids volatilize. Moisten the cold mass with a few drops of a saturated solution of ammonium carbonate, dry, and heat to 150° to expel excess of ammonia. The loss in weight of the sample represents organic matter, water of combination, salts of ammonia, etc. According to Knop[193] the total loss on ignition is determined as follows: About two grams of the fine earth are carefully ignited until all organic matter is consumed. The sample is then mixed with an equal volume of finely powdered, pure oxalic acid, and again heated until all the oxalic acid is decomposed. After cooling, the sample is weighed, again mixed with oxalic acid, ignited, cooled, weighed, and the process continued until the weight is constant. The method recommended by König consists in igniting about ten grams of the fine earth at the lowest possible temperature until all the humus is destroyed. Thereafter the sample is repeatedly moistened with a solution of ammonium carbonate and ignited after drying at 100°, until constant weight is obtained. In soils rich in carbonates some carbon dioxid may be lost by the above process. For this a proper correction can be made by estimating the carbon dioxid in the sample, both before and after the execution of the above described process. The method described by Frühling as much used in the German laboratories, consists in igniting ten grams of the fine earth, previously dried at 140° in a crucible placed obliquely on its support and with the cover so adjusted over its mouth as to give a draft within the body of the crucible. The ignition, at a gentle heat is continued until on stirring with a platinum wire no evidence of unconsumed carbon is found. The moistening with solution of ammonium carbonate, should not take place until the contents of the crucible are cool. Subsequent ignition, at a low heat for a short time, will remove the excess of ammonium salt. =301. Method of Berthelot and André.=[194]—The earth dried at 110° contains still a greater or less quantity of combined water. This is the water united with alumina, silica and certain salts, but not the water of constitution belonging to organic bodies. The exact estimation of this water offers many difficulties. The determination of loss obtained at a red heat embraces: (1) The water combined with zeolitic silicates, with alumina and with organic compounds. (2) The water produced by the combustion of the organic compounds. (3) The carbon dioxid resulting from the partial decomposition of the calcium and magnesium carbonates. (4) The carbon burned and the nitrogen lost during ignition. The measure of the loss of weight in an earth heated to redness in contact with the air is not therefore, an exact process of estimating water or even volatile matters. A better defined result is obtained in carefully burning a known weight of earth either in a current of free oxygen, or with lead chromate. The water produced in such a combustion is secured in a =ᥩ= tube filled with pumice stone saturated with sulfuric acid, the carbon dioxid being absorbed afterwards in potash bulbs and by solid potash. The weight of earth burned is chosen so as to furnish a convenient weight of both water and carbon dioxid. In general about five grams are sufficient. When the combustion is made with oxygen, the soil is contained in a boat and the products of the combustion are carried over a long column of copper oxid heated to redness. The residue left in the boat is weighed at the end of the operation, and in this residue it is advisable to determine any undecomposed carbonate. Should the sample burn badly and be mixed with carbonaceous matter at the end of the operation, it will be necessary to substitute the lead chromate method. In this case, of course, the residue left after combustion is not weighed. Whichever method is employed gives a quantity of water originally combined with the soil, plus the quantity arising from the combustion of the hydrogen of the organic matter. The details of the processes for organic combustion, will be given in a subsequent part of this manual. It is not possible to divide the water between these two sources directly, but this can be done by calculation, which gives results lying within the limits of probability. The method follows: The organic nitrogen, determined separately, by soda-lime, the method of Kjeldahl, or volumetrically, is derived from proteid principles resembling albuminoids containing about one-sixteenth of their weight of nitrogen. The nitrates contained in the earth are in such feeble proportion, as to be negligible in this calculation. The total weight of these nitrogenous principles in the soil is therefore easily calculated. The carbon contained in the proteids is then calculated on a basis of 53 per cent of their total weight, and the hydrogen on a basis of 7.2 per cent. From the weight of the total organic carbon (determined as described further on) is subtracted the carbon present in the proteids. The remainder corresponds to the organic carbon present as carbohydrates, (ligneous principles) containing 44.4 per cent carbon and 6.2 per cent hydrogen. By adding together the weight of the hydrogen contained in the ligneous principles, and the hydrogen contained in the proteids, and multiplying the sum by 9, the weight of water formed by the combustion of all the organic matter in the sample is obtained. This is subtracted from the weight of the total water obtained by direct determination as described above. The difference represents the weight of water combined with the silicates, etc., as well as with organic matters. =302. Method of Von Bemmelén.=[195]—According to the view of Von Bemmelén, the soil contains colloidal humus and colloidal silicate, which complicate the determination of water. The colloids retain water in varying quantities, depending upon the following conditions: (1) Upon their composition and state of molecular equilibrium. (2) Upon the pressure of the aqueous vapor of the room. (3) Upon the temperature. At each degree of temperature, the quantity of absorbed water which a colloid can retain in a room saturated with aqueous vapor, is different. The quantity of water which air-dried earth gives off at 100°, has therefore, no special significance unless all conditions are known. In addition to the estimation of the quantity of water which soils, in their natural condition, are capable of taking up and holding, at ordinary temperatures, the estimation of the quantity of water which they can take up in different temperatures in rooms saturated with aqueous vapor should be of interest. It follows, therefore, that there is no special value in data obtained by drying earth at 100° or 110°. For the purpose of comparison, he prefers to select that point at which the soil is dried over sulfuric acid, the point at which the tension of the water vapor in the earth, at a temperature of plus or minus 15°, approaches zero. The water which still remains in the earth under these conditions is characterized as firmly combined water. Von Bemmelén truly observes that only in soils which contain no carbonates and no chlorids and sulfids, can the loss on ignition be regarded as the sum of the humus and water content. By moistening with ammonium carbonate, the correction for lime or carbon dioxid cannot be correctly made as has been the custom up to the present time. In the first place, ignited magnesia, when it has lost its carbon dioxid, does not take this up completely on moistening with ammonium carbonate; in the second place, reactions with the chlorids may take place; and in the third place, the lime which is in the humus will be converted into calcium carbonate. Chlorids on ignition may be volatilized or oxidized. The sulfuric acid formed from the sulfids, on ignition, can expel carbon dioxid; further than this the iron of pyrites takes up oxygen on ignition. All these influences make the numbers obtained from loss on ignition extremely variable. With sea soils, Von Bemmelén has weighed the soil after the elementary analysis and estimated, in addition to the carbon dioxid, both chlorin and sulfuric acid therein. The comparison of these estimations with those of CO₂, Cl, SO₃ and S, made in the original soil, gave the necessary corrections; _viz._, for the increase in the weight through oxidation of sulfur and iron, and for the decrease in weight through the volatilization of sodium chlorid, sulfur, and carbon dioxid. A trace of chlorin was evolved as ferric chlorid, nevertheless, the molecular weight of sodium chlorid, 58.5, is scarcely different from the equivalent quantity of ferric chlorid 54.1. For this reason the estimation of loss of water, on ignition, of sea soils is less exact than that of soils which are free from carbonates and sulfids and which, as is usually the case with tillable soils, contain only small quantities of chlorids and sulfates. _The Strongly Combined Water._—Water which, at a temperature of plus or minus 15°, in a dry room, still remains in the soil, is chiefly combined according to Von Bemmelén with the colloidal bodies therein. Its estimation, presents, naturally, difficulties and is not capable of any great exactness. The quantity of strongly combined water, on the one hand is determined from the difference between the loss on ignition and the quantity of humus present, calculated from the content of carbon; on the other hand, from the difference between the water obtained by elementary analysis and the water which corresponds to the calculated quantity of humus. If the hydrogen content of humus is correctly taken and no appreciable error is introduced through the factor 1.724, both of these differences must agree. On the other hand the hydrogen content of the humus can be computed from the difference between the water found and the calculated content of the firmly combined water. The hydrogen content of humus bodies, dried at 100°, varies between four and five per cent. Eggertz has found the content from 4.3 to 6.6 per cent of hydrogen in thirteen soils which he first treated with dilute hydrochloric acid then extracted with ammonia or potash lye and precipitated this alkaline extract with acid. The method of applying these principles to soil analysis is indicated in the following scheme: A volcanic earth from Deli gave, on elementary analysis: Per cent. Carbon 2.94 Water 14.78 Nitrogen 0.28 Loss on ignition 17.54 FIRST CALCULATION. Per cent. Loss on ignition 17.54 Humus = carbon, 2.94 × 1.724 = 5.07 Difference = firmly combined water 12.47 Assuming that a humus dried over sulfuric acid contains five per cent of hydrogen, the second calculation is made as follows. SECOND CALCULATION. 5.00 humus × 5 per cent = 0.25 per cent of hydrogen in humus corresponding to 2.28 per cent of water. Per cent. Water found 14.79 Difference = firmly combined water 12.51 THIRD CALCULATION. Per cent. Firmly combined water 12.47 Water from the hydrogen in humus 2.28 Total water 14.75 Found 14.79 In this way, in three other volcanic earths and in an ordinary alluvial clay from Rembang, there were found by analysis and by calculation the following percentages of water: 1. 2. 3. 4. 5. Percentage of water calculated 14.75 7.74 8.06 4.90 6.01 „ „ „ found 14.97 7.63 8.05 4.70 6.00 On the contrary, when the calculation is made from sea-slime taken from under the water a higher content of hydrogen must be assumed; _viz._, about six per cent. In two samples of sea-slime calculated in this way the following numbers were obtained: Percentage of water calculated 8.61 3.71 „ „ „ found 8.53 3.57 It is, therefore, quite evident that the organic compounds of soil taken from under the sea-water are richer in hydrogen than those exposed to the air or in cultivation. =303. General Conclusions.=—In the foregoing paragraphs have been collected the most widely practiced methods of determining moisture in soil in both a free and combined state. The following conclusions may serve to guide the analyst who endeavors to determine the water in any or all of its conditions: (1) In determining water in fresh samples the method of Whitney is satisfactory. Although the samples taken by this method are small they may be easily secured in great numbers over widely scattered areas, and can be easily transported without change. These samples should be dried at 100° to 110° for rapid work, or where time can be spared may be air-dried. (2) For a simple determination of the water left in the soil after air-drying (hygroscopic water) the method of the Association of Official Agricultural Chemists may be followed. There is much difference of opinion in respect of the proper temperature at which this moisture is to be determined. Much here depends on the nature of the soil. An almost purely mineral soil may safely be dried at 140° or 150°. A peaty soil, on the contrary, should not be exposed to a temperature above 100°. For general purposes the temperature chosen by the official chemists is to be recommended. (3) Water of composition can only be determined by ignition. As has been fully shown, this process not only eliminates the water, but also destroys organic matter, decomposes carbonates and sulfids, and, to some extent, chlorids. Subsequent repeated treatment with ammonium carbonate may restore the loss due to carbon dioxid, but in many cases not entirely. The water which comes from organic matter may be approximately calculated from the humus content of the sample, but as will be seen further on the methods of estimating humus itself are only approximate. Nevertheless, in distributing the losses on ignition properly to the several compounds of the soil there is no better method now known than that of taking into consideration the humus content and carbonates present. The principles of procedure established by Berthelot and André, and Von Bemmelén, are to be applied in all such cases, modified as circumstances may arise according to the judgment of the analyst. =304. Estimation of the Organic Matter of the Soil.=—The organic matter in the soil may be divided into two classes. First, the undecayed roots and other remains of plant and animal life, and the living organisms existing in the soil. The study of the organisms which are active in the condition of plant growth will be the subject of a special chapter. Second, the decayed or partially decayed remnants of organic matter in the soil known as humus. Such matter may be present in only minute traces, as in barren sand soils, or it may form the great mass of the soil under examination, as in the case of peat, muck, and vegetable mold. It is with the investigation of the second class of matter that the analyst has chiefly to do at present. The problems which are to be elucidated by the analytical study of such bodies are the following: (1) The total quantity of such matter in the soil. (2) The determination of the organic carbon and hydrogen therein. (3) The determination of total nitrogen. (4) The determination of the availability of the nitrogen for plant growth. (5) The estimation of the humic bodies (humus, humic acid, ulmic acid, etc.). The importance of humus in the promotion of plant growth is sufficient excuse for the somewhat extended study of the principles which underlie the analytical methods, and the methods themselves, which follow. =305. Total Quantity of Organic Matter.=—The total approximate quantity of organic matter in the soil can be determined by simple ignition, in the manner noted in paragraphs =294= and =295=. The proper correction for free and combined water being applied by the further copper oxid or lead chromate combustion of the sample, and for carbonates and volatile chlorids, the approximate total of the organic matter of all kinds is obtained. =306. Estimation of the Organic Carbon.=—To estimate the organic carbon in an earth the sample may be burned in a current of oxygen, or after mixing with lead chromate. _In a Current of Oxygen._—When burned in a current of oxygen the sample is held in a boat and the gases arising from the combustion directed over copper oxid at a red heat. The carbon thus disappears as carbon dioxid and is absorbed and weighed in the usual way. _With Lead Chromate._—The lead chromate employed should be previously tested since it often contains other compounds, especially lead acetate and nitrate, furnishing in the one case both carbon dioxid and water, and in the other hyponitric acid. From two to ten grams of earth are employed, according to its richness in organic matter. The total carbon dioxid is obtained in this process both from carbonates and organic bodies. The water and carbon dioxid are secured and weighed in the usual manner. The oxygen method should be used in all cases possible. Although it does not always give the whole of the carbon dioxid present as carbonates, the rest can be easily estimated by treating the residue in the boat with hydrochloric acid, in an apparatus for estimating that gas. _Calculation of Results._—The whole of the carbon dioxid is determined either by direct combustion with lead chromate, or by taking the sum of the amounts by burning in a stream of oxygen and treating the residue in a carbon dioxid apparatus. The carbon dioxid contained in the original carbonates should be determined by direct treatment of the sample in the usual way. The carbon in organic compounds is determined by subtracting the carbon present as carbonates from the total. From the organic carbon contained in the soil the humus is calculated by Wolff on the supposition that it contains fifty-eight per cent of carbon. It is, therefore, only necessary to multiply the percentage of carbon found by 1.724, or the carbon dioxid found by 0.471, to determine the quantity of humus in the dried soil. =307. Details of the Direct Estimation of Carbon in Soils by Various Methods.=—(1) _Oxidation by Chromic Acid._—The method of Wolff by oxidation with chromic acid has been worked out in detail by Warington and Peake.[196] It consists in treating the soil with sulfuric acid and potassium bichromate, or by preference with a mixture of sulfuric and chromic acids, the carbon dioxid evolved being estimated in the usual way. This method is recommended by Fresenius as an alternative to a combustion of the soil with copper oxid or lead chromate. It is apparently the method which has been most generally employed in agricultural investigations. Ten grams of the finely powdered soil are placed in a flask of about 250 cubic centimeters capacity, provided with a caoutchouc stopper, through which pass two tubes, one for the supply of liquids, the other for the delivery of gas. The soil is treated with twenty cubic centimeters of water and thirty cubic centimeters of oil of vitriol; and the whole, after being thoroughly mixed, is heated for a short time in a water-bath, the object in view being the decomposition of any carbonates existing in the soil. Air is next drawn through the flask to remove any carbon dioxid which has been evolved. The stopper is next removed, and coarsely powdered potassium bichromate introduced. In the case of a soil containing three per cent of carbon, six grams of bichromate will be found sufficient, a portion remaining undissolved at the end of the experiment. The stopper is then replaced, its supply-tube closed by a clamp, and the delivery-tube connected with a series of absorbents contained in =ᥩ= tubes. The first of these tubes contains solid calcium chlorid; the second, fragments of glass moistened with oil of vitriol; the third and fourth are nearly filled with soda-lime, a little calcium chlorid being placed on the top of the soda-lime at each extremity. The last named tubes are for the absorption of carbon dioxid, and have been previously weighed. The series is closed by a guard-tube containing soda-lime, with calcium chlorid at the two ends. The flask containing the soil and bichromate is now gradually heated in a water-bath, the contents of the flask being from time to time mixed by agitation. A brisk reaction occurs, carbon dioxid being evolved in proportion as the soil is rich in organic matter. The temperature of the water-bath is slowly raised to boiling as the action becomes weaker, and is maintained at that point till all action ceases. As bubbles of gas are slowly evolved for some time, it has been usual in these experiments to prolong the digestion for four or five hours. When the operation is concluded the source of heat is removed, an aspirator is attached to the guard-tube at the end of the absorbent vessels, and air freed from carbon dioxid is drawn through the flask and through the whole series of =ᥩ= tubes. The =ᥩ= tubes filled with soda-lime are finally weighed, the increase in weight showing the amount of carbon dioxid produced. The object of the calcium chlorid placed on the surface of the soda-lime is to retain the water which is freely given up when the soda-lime absorbs carbon dioxid. The second =ᥩ= tube filled with soda-lime does not gain in weight till the first is nearly saturated; it thus serves to indicate when the first tube requires refilling. The same tubes may be used several times in succession. No increase in the carbon dioxid evolved is obtained by substituting chromic acid for potassium bichromate. The organic matter of the soil appears to the eye to be completely destroyed by the digestion with sulfuric acid and potassium bichromate; the residue of soil remaining in the flask when washed with water is perfectly white, or the dark particles, if any, are found to be unaltered by ignition, and therefore to be inorganic in their nature. Under these circumstances considerable confidence has naturally been felt in this method. The complete destruction of the humic matter of the soil does not, however, necessarily imply that the carbon has been entirely converted into carbon dioxid as has been pointed out by Wanklyn. According to his demonstration of the action of chromic acid on organic matter the oxidation frequently stops short of the production of carbon dioxid. While oxidation with chromic acid apparently leads to a complete reaction when the carbon is in the form of graphite, it would probably yield other products than carbon dioxid when the carbon exists as a carbohydrate. The doubt thus raised as to the correctness of the results yielded by the chromate method makes it desirable to check the work by the use of other methods for the determination of carbon. For this purpose Warington and Peake recommend: (2) _Oxidation with Potassium Permanganate._—In the trials with this method ten grams of soil are digested in a closed flask with a measured quantity of solution of caustic potash containing five grams of potash for each twenty cubic centimeters, and crystals of potassium permanganate. Seven grams of the permanganate are found to be sufficient for a soil containing 3.3 per cent of carbon. The flask is heated for half an hour in boiling water, and then for one hour in a salt-bath. The flask during this digestion is connected with a small receiver containing a little potash solution, to preserve an atmosphere free from carbon dioxid; distillation to a limited extent is allowed during the digestion in the salt-bath. The first part of the operation being completed a rubber stopper, carrying a delivery and supply-tube, is fitted to the flask, which is then connected with the system of =ᥩ= tubes already described. Dilute sulfuric acid is then poured down the supply-tube, a water-bath surrounding the flask is brought to boiling, and maintained thus for one hour, after which air, free from carbon dioxid, is drawn through the apparatus, the =ᥩ= tubes containing soda-lime being finally disconnected and weighed. In the first stage of this method the carbon of the organic matter is converted into carbonate, and probably also into potassium oxalate.[197] In the second stage the oxalate is decomposed by the sulfuric acid and permanganate, and the carbon existing, both as oxalate and carbonate, is evolved as carbon dioxid, and absorbed by the weighed soda-lime tubes. Both F. Schulze and Wanklyn have employed potassium permanganate for the determination of organic carbon, but they have preferred to calculate the amount of carbon from the quantity of permanganate consumed, as, however, by so doing everything oxidizable by permanganate is reckoned as carbon, it seems better to make a direct determination of the carbon dioxid formed. From the amount of carbon dioxid found, is to be subtracted that existing as carbonates in the soil, and in the solution of potash used. For this purpose an experiment is made with the same quantities of soil and potash previously employed, but without permanganate, and the carbon dioxid obtained is deducted from that yielded in the experiment with permanganate. If the potash used contains organic matter two blank experiments will be necessary, one with potash and permanganate, and one with soil alone. A further difficulty arises from the presence of chlorids in the materials, which occasions an evolution of free chlorin when the permanganate solution is heated with sulfuric acid. This error occurs also with the chromic acid method, but in that case the quantity of chlorid is merely that contained in the soil, which is usually very small; in the permanganate method we have also the chlorid present in the caustic potash, and this is often considerable. Corrections for chlorin by blank experiments are unsatisfactory, the amount of chlorin which reaches the soda-lime tubes depending in part on the degree to which the calcium chlorid tube has become saturated with chlorin. It is better therefore to remove the chlorin in every experiment by the plan which Perkin has suggested, by inserting a tube containing silver foil, maintained at a low red heat, between the flask and the absorbent =ᥩ= tubes. The amount of carbon dioxid yielded by oxidation with potassium permanganate is found to be considerably in excess of that obtained by oxidation with chromic acid; to ascertain whether these higher results really represented the whole of the carbon present in the soil, trials were next made by actual combustion of the soil in oxygen. (3) _Combustion in Oxygen._—The most convenient mode of carrying out the combustion of soil is to place the soil in a platinum boat, and ignite it in a current of oxygen in a combustion tube partly filled with cupric oxid. A wide combustion tube is employed, about twenty inches long, and drawn out at one end; the front of the tube is filled for eight inches with coarse cupric oxid, the hind part is left empty to receive the platinum boat. The drawn out end of the combustion tube is connected with a series of absorbent =ᥩ= tubes, quite similar to those employed for the estimation of carbon dioxid in the chromic acid method. Between these absorbent vessels and the combustion tube is placed a three-bulbed Geissler tube filled with oil of vitriol. The oil of vitriol is quite effective in retaining nitrous fumes. The wide end of the combustion tube is connected with a gas-holder of oxygen; the oxygen gas is made to pass through a =ᥩ= tube of soda-lime before entering the combustion tube, to remove any possible contamination of carbon dioxid. In starting a combustion the part of the combustion tube containing the cupric oxid is brought to a red heat, and oxygen is passed for some time through the apparatus. Ten grams of soil, previously dried, are placed in a large platinum boat, which is next introduced at the wide end of the combustion tube. The combustion is conducted in the usual manner, a current of oxygen being maintained throughout the whole operation. It is very useful to terminate the whole series of absorbent vessels with a glass tube dipping into water; the rate at which the gas is seen to bubble, serves as a guide to the supply of oxygen from the gas-holder, the consumption of oxygen varying, of course, with different soils, and at different stages of the combustion. At the close of the combustion, oxygen, or air freed from carbon dioxid, is passed for some time through the apparatus to drive all carbon dioxid into the absorbent vessels. One experiment can be followed by another as soon as the hind part of the combustion tube has cooled sufficiently to admit a second platinum boat. The same combustion tube can be employed for several days, if packed in the usual manner in asbestos. The presence of carbonates in the soil occasions some difficulty in working the combustion method, as a part of this carbon dioxid will, of course, be given up on ignition, and be reckoned as carbon. The simplest mode of meeting this difficulty is to expel the carbon dioxid belonging to the carbonates before the combustion commences. The method of Manning; namely, treatment with a strong solution of sulfurous acid, may be employed for this purpose. The ten grams of soil taken for combustion are placed in a flat-bottomed basin, covered with a thin layer of sulfurous acid, and frequently stirred. After a time the action is assisted by a gentle heat. When the carbonates have been completely decomposed the contents of the basin are evaporated to dryness on a water-bath; the dry mass is then pulverized, and removed to the platinum boat for combustion in oxygen. For the action of the sulfurous acid to be complete it is essential that the carbonates should be in very fine powder, since even chalk is but imperfectly attacked when present in coarse particles. =308. Comparison of Methods.=—A considerable number of soils analyzed by the chromic acid method and by the combustion, method, by Warington and Peake, with the assistance of Cathcart, shows the following comparisons: PERCENTAGE OF CARBON FOUND BY TWO METHODS IN SOILS DRIED AT 100°. Chromic acid method. Combustion method. No. Kind of Exp. 1. Exp. 2. Mean. Exp. 1. Exp. 2. Mean. Per soil. cent. yielded by chromic acid. 1. Old pasture 2.85 2.79 2.82 3.58 3.55 3.57 79.0 2. „ „ 2.83 2.79 2.81 3.57 3.53 3.55 79.1 3. „ „ 2.76 2.76 2.76 3.46 3.46 3.46 79.7 4. „ „ 2.74 2.76 2.75 3.37 3.38 3.38 81.4 5. „ „ 2.64 2.54 2.59 3.31 3.36 3.34 77.5 6. „ „ 2.51 2.43 2.47 3.15 3.15 3.15 78.4 7. „ „ 2.40 2.44 2.42 3.09 3.13 3.11 77.8 8. New pasture 1.92 1.93 1.93 2.41 2.40 2.41 80.1 9. „ „ 1.66 1.81 1.74 2.39 2.43 2.41 72.2 10. Arable soil 1.78 1.78 1.78 2.14 2.13 2.14 83.2 11. „ „ 1.21 1.14 1.18 1.40 1.43 1.42 83.1 12. Subsoil 0.28 0.27 0.28 0.37 0.38 0.38 73.7 Of the above soils the arable soils, Nos. 10 and 11, were the only ones containing carbonates in any quantity exceeding a minute trace. The two soils in question were treated with sulfurous acid before combustion, the others not. All the determinations by the chromic acid method were made by Mr. P. H. Cathcart, with the exception of Nos. 9 and 12, which were executed by another experimenter, and are seen to give distinctly lower results. Excluding these two analyses the relation of the carbon found by the two methods is tolerably constant, the average being 79.9 of carbon found by oxidation with chromic acid for 100 yielded by combustion in oxygen. The results obtained by the chromic acid method thus appear to be very considerably below the truth. Four typical soils were analyzed by the permanganate, as well as by the chromic acid and combustion methods. The results obtained were as follows: PERCENTAGE OF CARBON FOUND BY THREE METHODS IN SOILS DRIED AT 100°. Permanganate method. Kind of Chromic Yielded by soil. acid permanganate Combustion method. if carbon by method. Mean. Exp. 1. Exp. 2. Mean. combustion = Mean. Per Per Per Per Per 100. Per cent. cent. cent. cent. cent. cent. Old pasture 3.55 2.81 3.26 3.30 3.28 92.4 New pasture 2.41 1.93 2.29 2.30 2.30 95.4 Arable soil 1.42 1.18 1.28 1.33 1.31 92.3 Subsoil 0.38 0.28 0.34 0.34 0.34 89.5 Oxidation by permanganate thus gives a much higher result than oxidation with chromic acid; but even the permanganate fails to convert the whole of the carbon into carbon dioxid, the product with permanganate being on an average of the four soils 92.4 per cent of that yielded by combustion in oxygen. Wanklyn states that a temperature of 160°–180° is necessary in some cases to effect complete oxidation with permanganate and caustic potash. Such a temperature is found impracticable when dealing with soil, from the action of the potash on the silicates present; hence possibly the low results obtained. Combustion in oxygen appears from these experiments to be the most satisfactory method for determining carbon in soil, nor is this method, on the whole, longer or more troublesome than the other methods investigated. Warington and Peake have further determined the loss on ignition of the four soils mentioned above, with the view of comparing this loss with the amount of organic matter calculated from the carbon actually present. In making this calculation they have taken as the amount of carbon in the soil, that found by combustion in oxygen, and have assumed with Schulze, Wolff, and Fresenius, that fifty-eight per cent of carbon will be present in the organic matter of soils. The four soils were heated successively at 100°, 120°, and 150°, till they ceased to lose weight; the loss on ignition in each of these stages of dryness is shown in the following table: PERCENTAGE LOSS ON IGNITION COMPARED WITH ORGANIC MATTER CALCULATED FROM CARBON. Organic matter at fifty-eight Between 100° Between 120° Between 150° per cent and ignition. and ignition. and ignition. carbon. Kind of soil. Per cent. Per cent. Per cent. Per cent. Old pasture 9.27 9.06 8.50 6.12 New pasture 7.07 6.88 6.55 4.16 Arable soil 5.95 5.70 5.61 2.44 Clay subsoil 5.82 5.39 4.76 0.65 The loss on ignition is seen to be in all cases very considerably in excess of the organic matter calculated from the carbon, even when the soil has been dried at as high a temperature as 150°. The error of the ignition method is least in soils rich in organic matter, as, for instance, the old pasture soil in the above table. The error reaches its maximum in the case of the clay subsoil, which contains very little carbonaceous matter, but is naturally rich in hydrated silicates, which part with their water only at a very high temperature. The above methods of Warington and Peake have been given in detail, and in almost the verbiage of the authors for the reason that the working directions are clearly set forth, and may serve, therefore, as guides to the previous methods where only general indications of manipulation have been given. =309. Estimation of Organic Hydrogen.=—The estimation of the total hydrogen is made without difficulty either by burning the sample in a current of oxygen or with lead chromate, and weighing the water produced. This water comes from two sources, the pre-existing water and organic hydrogen. There is no direct method of distinguishing one from the other. They may, however, be estimated indirectly. The method of calculating the organic hydrogen has already been given (paragraph =299=). Experience shows that the hydrogen thus calculated is a little greater than is necessary to form water with the whole of the oxygen found in the organic matters. =310. Estimation of Organic Oxygen.=—The determination of this oxygen cannot be made directly. It is obtained by calculation, according to Berthelot and André,[198] from the oxygen in the proteid and ligneous matters. Let p represent the weight of the proteid bodies in a sample of soil. Then O = (p × 33.5)/(100) Let p′ = weight of ligneous bodies. Then O′ = (p′ × 49.4)/(100) The total oxygen = O + O′. An approximate result is thus obtained, very useful to have when account is taken of the oxidizing processes which go on in the soil during agricultural operations. =311. Estimation of Humus (Matière Noire).=—The original method of determining this substance is due to Grandeau.[199] It is carried on as follows: Ten grams of the fine earth are mixed with coarse sand previously washed with acids and ignited. The mixture is placed in a small funnel, the bottom of which is filled with fragments of glass or porcelain. The mass is moistened with ammonia diluted with an equal volume of distilled water, and allowed to digest for three or four hours. The ammonia dissolves the dark matter without attacking the silica. The ammoniacal solution is displaced by treating the mass with pure water, or water to which some ammonia has been added, and the whole of the dark matter is thus obtained in a volume of twenty to fifty cubic centimeters of filtrate. The filtrate is evaporated to dryness in a weighed platinum dish, and the weight of residue is determined and the percentage of _matière noire_ calculated therefrom. The residue is incinerated, and when in sufficient quantity the phosphoric acid is determined in the ash. In soils poor in humus a larger quantity than ten grams may be taken. If the soil be previously treated with hydrochloric acid, Grandeau recommends that the phosphoric acid be determined always in the ash of the dark matter. The method has undergone various modifications and, as given by Hilgard, is now practiced as follows: About ten grams of soil are weighed into a prepared filter. The soil should be covered with a piece of paper (a filter) so as to prevent it from packing when solvents are poured on it. It is now treated with hydrochloric acid from five-tenths per cent to one per cent strong (twenty-five and one-third cubic centimeters of strong acid and 808 cubic centimeters of water) to dissolve the lime and magnesia which prevent the humus from dissolving in the ammonia. Treat with the acid until there is no reaction for lime; then wash out the acid with water to neutral reaction. Dissolve the humus with weak ammonia water, prepared by diluting common saturated ammonia water (178 cubic centimeters of ammonia to 422 cubic centimeters of water). Evaporate the humus solution to dryness in a weighed platinum dish at 100°; weigh, then ignite; the loss of weight gives the weight of humus. The residue from ignition is carbonated with carbon dioxid, heated and weighed, thus giving the ash. It is then moistened with nitric acid and evaporated to dryness. The residue is treated with nitric acid and water, allowed to stand a few hours, and the solution filtered from the insoluble residue, which is ignited and weighed, giving the silica. The soluble phosphoric acid is determined in the solution by the usual method, as magnesium pyrophosphate. It usually amounts to a fraction, varying from one-half to as little as one-tenth of the total in the soil. While the phosphoric acid so determined is manifestly more soluble and more available to vegetation than the rest of that found by extraction with stronger acid, it is clearly not as available as that which, when introduced in the form of superphosphates, exerts such striking effects even though forming a much smaller percentage of the whole soil. Nevertheless, very striking agreement with actual practice is often found in making this determination. The estimation of humus by combustion, in any form, of the total organic matter in the soil, gives results varying according to the season, and having no direct relation to the active humus of the soil. The same objection lies against extraction with strong caustic lye. =312. Modification of Grandeau’s Method for Determining Humus in Soils.=—According to Huston and McBride[200] the function of the vegetable matter in the soil has long been a matter of contention among those interested in the science of agriculture. Two factors have contributed to the uncertainty existing in this matter: First, the very complex and varying nature of the compounds resulting from the decomposition of vegetable matter in the soils; and second, the lack of uniformity in the methods of determining either the total amount of organic matter present in a soil, or the amount that has been so far decomposed as to be of any immediate agricultural value. Prominent among these methods are the methods in which a combustion is resorted to, the substance being either burned in air or in a combustion tube with some agent supplying oxygen. The loss on ignition is no measure of the amount of organic matter present since it is practically impossible to remove all the water from the soil previous to ignition, and neither of the methods gives information regarding the extent of the decomposition of the organic matter. Pure cellulose and the black matter of a fertile soil are of very different agricultural value. Determinations of carbon in soils by oxidation with chromic and sulfuric acid, and with alkaline permanganate have been used. The method with alkaline permanganate agrees fairly well with combustion with copper oxid or lead chromate, but the chromic sulfuric acid method gives only about eighty per cent of the carbon found by combustion processes. However valuable these processes may be for determining the total carbon in the soil, they furnish no information regarding the condition of the carbonaceous soil constituents, and as the determination is really one of carbon, the organic matter must be calculated by using an arbitrary factor. Generally the organic matter of the soil is considered to have fifty-eight per cent carbon; yet different values are given from forty to seventy-two per cent. There is a general opinion that the black or dark brown material of the soil, resulting from the decay of vegetable matter, has a much higher agricultural value than the undecomposed vegetable matter. No very sharp dividing line can be drawn, for changes in the soil are continually going on, and material may be found in almost every stage between pure cellulose and carbon dioxid. The character of the intermediate products will vary according to the conditions of tillage and the supply of air and water. For agricultural purposes some means of determining the amount of decomposed matter is very desirable. Several solvents have been tried for this purpose. The earlier attempts were made by treating the soil with successive quantities of boiling half-saturated solution of sodium carbonate until the soil appeared to yield no more coloring matter to the solvent. The solutions were then united, rendered acid with HCl, which precipitated the humic acid, which was then washed, dried, and weighed. This was considered the more soluble portion of the humic acid. The soil was afterward treated with caustic potash solution in the same manner, and the humus thus extracted was called insoluble humus. This last process was really more in the nature of manufacturing humus, for sawdust treated with caustic potash yields humic acid, and the inert organic matter in the soil was decomposed to some extent by the caustic alkali. Neither of the processes provided for the separation of the humic acid from the lime, magnesia, alumina, and iron with which it is usually combined in the soil. In case results of different workers are to be compared, it is of the greatest importance that methods should be used that are of such a nature that errors resulting from difference of manipulation, and from difficulty of reproducing duplicate work can be reduced to a minimum. Hence, a simple modification of the Grandeau method has been tried which has the advantage of keeping a definite amount of the soil in contact with a definite volume of ammonia for a fixed time, the strength of the ammonia remaining constant. The process is as follows: The soil is washed with acid and water as usual. It is then washed into a 500 cubic centimeter cylinder with ammonia, the cylinder closed and well shaken and allowed to remain for a definite time, usually thirty-six hours. The material is shaken at regular intervals. The cylinder is left inclined as much as possible without having the fluid touch the glass stopper, thus allowing the soil to settle on the side of the cylinder and exposing a very large surface to the action of the ammonia. During the last twelve hours the cylinder is placed in a vertical position to allow the soil to settle well before taking out the aliquot part of the solution. The process of washing the soil with hydrochloric acid, water and ammonia, is very tedious when performed in the usual way with the wash-bottle. A simple automatic washing apparatus was devised by which a fixed volume of the washing fluid can be delivered at regular intervals, giving ample time for the thorough draining between each addition of the fluid, and requiring no attention. By this apparatus work can be continued day and night. Instead of washing on the usual form of filter paper in funnels, it is preferable with this apparatus to hold the soils on a disk of filter paper resting on a perforated porcelain disk in the bottom of the funnel. This removes the necessity of washing out the filter papers, does not permit of the accumulation of humus on the edge of the filter paper when the Grandeau process is used, and insures that all the washing fluids pass through the soil and not around it. This form of apparatus reduces the labor to a minimum and permits many determinations to be carried on at once. This form of apparatus was only lately devised and has only been used long enough to test it and to show its advantages. The reported results were obtained by the ordinary methods of washing. In all the work reported, five grams were used, as the soils contained so much humus that this amount gave enough humus for good work in the final weighings. The results obtained so far appear in the following tables: TABLE I. COMPARISON OF METHOD OF GRANDEAU WITH HUSTON’S MODIFICATION AND OF INFLUENCE OF STRENGTH OF AMMONIA SOLUTION. TIME OF DIGESTION IN MODIFIED METHOD THIRTY-SIX HOURS. Two per cent Four per cent NH₃. NH₃. Grandeau. Huston. Grandeau. Huston. 1. Peat soil, 16.40 20.06 Bogus „ 13.98 20.80 „ „ 17.43 ————— ————— Mean 15.94 20.43 2. Peat subsoil, 13.98 19.38 Bogus „ 13.85 20.30 ————— ————— Mean 13.92 19.84 3. Peat soil, 9.05 15.60 14.71 21.24 Good „ 10.27 15.88 15.34 20.20 ————— ————— ————— ————— Mean 9.61 15.74 15.03 20.72 4. Peat subsoil, 16.75 24.34 Good „ 18.60 23.52 ————— ————— Mean 17.68 23.93 5. Black soil, A 3.90 6.90 (1.86) 7.42 „ „ „ (1.67) 6.98 „ „ B 3.88 7.00 4.42 „ „ „ 4.20 ————— ————— ————— ————— Mean 3.99 6.95 (3.05) 7.20 „ 4.31 6. Clay loam, 1.86 4.20 2.40 4.26 West side, A 4.28 „ „ B 1.76 4.36 2.48 (3.40) „ „ „ (3.10) ————— ————— ————— ————— Mean 1.81 4.28 2.44 (3.76) „ 4.27 7. Clay loam, A 1.90 4.12 (1.60) (4.59) Lysimeter soil, B 1.61 4.22 (1.41) (4.58) „ „ C 1.80 4.12 „ „ D 1.95 4.04 „ „ E 1.92 3.85 „ „ F 1.95 4.08 „ „ G 1.90 3.93 „ „ H 1.90 3.80 ————— ————— ————— ————— Mean 1.76 4.17 (1.80) (4.12) „ 1.90 3.97 Seven per cent Eight per cent NH₃. NH₃. Grandeau. Huston. Grandeau. Huston. 1. Peat soil, Bogus „ „ „ Mean 2. Peat subsoil, Bogus „ Mean 3. Peat soil, 19.77 21.70 16.05 21.42 Good „ 19.85 21.90 15.40 21.80 ————— ————— ————— ————— Mean 19.81 21.80 15.73 21.61 4. Peat subsoil, Good „ Mean 5. Black soil, A „ „ „ „ „ B „ „ „ Mean „ 6. Clay loam, 2.14 4.02 1.85 4.12 West side, A „ „ B 2.13 4.48 1.90 4.40 „ „ „ ————— ————— ————— ————— Mean 2.14 4.25 1.88 4.26 „ 7. Clay loam, A Lysimeter soil, B „ „ C „ „ D „ „ E „ „ F „ „ G „ „ H Mean „ NOTE.—Numbers in parentheses indicate results, generally the earliest ones, which the authors do not consider strictly comparable with the rest of the work. They are given solely for the purpose of exhibiting all the work that has been done to date. When a mean is included in parentheses it indicates that it is calculated from all the results obtained, including those not considered strictly comparable. Bogus is a name given to a peaty soil which is very sterile. TABLE II. INFLUENCE OF TIME OF DIGESTION. FOUR PER CENT OF AMMONIA USED THROUGHOUT. HUSTON’S METHOD. Thirty-six Forty-eight Sixty-eight Ninety-eight hours. hours. hours. hours. Peat Soil, 21.24 22.28 24.04 Good „ 20.20 21.70 23.94 ————— ————— ————— Mean 20.72 21.99 23.99 Clay loam, 4.28 4.00 4.40 „ 4.26 4.01 4.85 West side (3.40) „ „ (3.05) —————— ————— ———— Mean 4.27 4.01 4.63 TABLE III. INFLUENCE OF TIME OF EXTRACTION. TIME, TEN DAYS. GRANDEAU’S METHOD, FOUR PER CENT AMMONIA. PEAT SOIL. A. B. Mean. Remarks. Per Per Per cent. cent. cent. 1st extraction, 750 cc 16.90 18.96 17.93 2nd „ 250 „ 2.80 2.38 2.59 3rd „ 250 „ 1.77 1.10 1.44 4th „ 250 „ 1.34 1.30 1.32 Stood over night. 5th „ 250 „ 0.89 0.85 0.87 6th „ 250 „ 1.41 1.65 1.53 Stood overnight. 7th „ 250 „ 2.10 1.80 1.95 Washed again with HCl for Ca. Trace found. HCl washed out, but trace of chlorids found in ash. Probably HCl absorbed from air as humus showed small quantity of a white volatile solid on evaporation. 8th „ 250 „ 0.67 0.65 0.66 9th „ 250 „ 0.57 0.50 0.53 ———— ————— ————— ————— Total 2750 „ 28.45 29.19 28.82 =313. Summary of Results.=—1. The modified method gives much higher results than the original method of Grandeau. 2. In the Grandeau method marked irregularities follow a change in the strength of the ammonia solution. These differences in results bear no relation to the strength of the solution used. They seem to be errors due to the difficulty of securing uniform and complete washing of the soil by the ammonia solution. In the modified method the change in the strength of the ammonia solution makes practically no difference in the amount of humus extracted, except in the case of the peat soil where two per cent ammonia failed to extract all the humus. But the results show no considerable increase when the strength is increased to over four per cent. 3. The factor of time has not been fully investigated, but the results so far obtained indicate that the time exerts less influence in the modified than in the Grandeau method. 4. Table III shows that considerable quantities of the peat soil are still passing into solution in the Grandeau method at the end of ten days. With ordinary soils this is not true; but in the case of soil No. 5, a black soil, the solutions were colored at the end of a week. On the peat soil the modified method extracted from ten to fifty per cent more than the Grandeau, and on the ordinary soil from two to three times as much humus. 5. In comparing duplicate results by both methods it is found that with soil No. 3, peat soil, the following differences appear calculated to percentage of the total amount involved in the determination: Per cent. Per cent. Per cent. Per cent. Strength of ammonia 2. 4. 7. 8. Modified 1.7 5. 1.0 1.8 Grandeau 13.0 4.3 0.5 3.4 Special attention was paid to this point in case of soil No. 7, an ordinary soil; taking all results into consideration the greatest difference in percentage of total amount involved was, by the modified method, nineteen per cent, and by the Grandeau, thirty per cent. In the set of six special determinations made by both methods to test this point and which are strictly comparable with each other, the maximum range was by the modified method 7.8 per cent and by the Grandeau 8.3 per cent of the total amount involved in the determination. From which it appears that the modified method is on the whole capable of yielding rather more concordant results than the Grandeau. =314. Estimation of Free Humic Acids.=—This process, due to Müntz[201] is essentially that of Huston and McBride. Twenty grams of the soil are reduced to a fine powder and saturated with fifty cubic centimeters of concentrated ammonia and allowed to digest two or three days in a warm place. The volume is then made up to one liter with water, well shaken, and set aside for one day in order to permit the subsidence of the solid matter. At the end of this time 500 cubic centimeters of the supernatant liquor are taken and acidified with hydrochloric acid in order to precipitate the humic bodies. The humus is collected on a filter, dried and weighed. It is then ignited and the weight of ash deducted from the first weight thus giving the actual weight of the humus obtained, free from mineral matter. This process gives the free humic acids. By previous treatment of the sample with hydrochloric acid as in the process of Huston and McBride, the total humus is obtained. The estimation of the free humic acids is of importance in determining the quantity of lime or marl which should be added to acid lands. =315. Humus Method of Von Bemmelén.=[202]—Von Bemmelén obtains the content of humus by the multiplication of the content of carbon in the soil by the factor of Wolff; _viz._, 1.724. The estimation of carbon, water, and of the loss on ignition is conducted in combustion tubes in a current of oxygen. The nitrogen estimation is carried on according to the method of Dumas. In soils containing calcium carbonate the carbon content is derived from the carbon dioxid taken up by the potash bulbs during combustion (a); from other carbonates not decomposed on ignition and which are subsequently determined in the residue by treatment with hydrochloric acid in a carbon dioxid apparatus, (b) and the total carbon dioxid derived from the carbonates in the soil (c). For each estimation from three to five grams of the soil are taken, because with smaller quantities the errors of analysis too strongly influence the results. The carbon is then calculated according to the formula: Carbon = ³⁄₁₁ (a + b − c). _The Carbon Dioxid of Carbonates._—It is necessary to expel the carbon dioxid at ordinary temperatures, because on heating to boiling, carbon dioxid would be formed from the humus. In a flask, as small as possible, the soil is treated at ordinary temperature, with dilute sulfuric or citric acid, the escaping gas dried over sulfuric acid and taken up with soda-lime. Behind the soda-lime is a small tube filled with pieces of glass and moistened with sulfuric acid, which retains any moisture taken out of the soda-lime. A stream of about one liter of air, free from carbon dioxid, is sufficient to drive out all of the carbon dioxid when the estimation is made at ordinary temperatures. A volcanic earth from Deli, which contained five per cent of humus, gave, at a temperature plus or minus 15°, 0.01 per cent CO₂. At boiling temperature two analyses gave 0.54 and 0.56 CO₂. This soil contained no carbonate, and the carbon dioxid found at the boiling temperature, must have come from the humus substances under the influence of the dilute acids. A heavy clay containing 6.9 per cent of humus gave, at plus or minus 15°, 3.60 per cent CO₂; at 100° without boiling, it gave an additional 0.53 per cent, and with boiling an additional 0.11 per cent, or a total of 4.24 per cent CO₂. A light clay containing 3.2 per cent of humus, gave, at 15°, 5.09 per cent CO₂; at a boiling temperature an additional 0.43 per cent, and by continued boiling an additional 0.27 per cent. =316. Estimation of Humus by the German Method.=—The German experiment stations follow the method of Loges,[203] depending on the oxidation of the humic bodies with copper oxid after evaporation of the sample with phosphoric acid. The object of the preliminary evaporation is to set the humic acids free in order that they may be better and more easily oxidized than when burned in the combined state. The sample of soil is placed in a Hoffmeister dish (Schälchen), moistened with dilute phosphoric acid and evaporated to complete dryness. The dish and its contents are rubbed up with pulverized copper oxid and placed in a combustion tube of sixty centimeters in length, open at both ends. There is then placed in the tube, and held in place by asbestos plugs, granular copper oxid to a length of twenty centimeters. The combustion tube is placed in a proper furnace and one end connected with two washing-flasks, the first containing potash lye, and the other a solution of barium hydroxid. These flasks are to free the aspirated air from carbon dioxid. The other end of the combustion tube is connected with an appropriate apparatus for absorbing the carbon dioxid. Loges recommends the Pettenkofer absorption tube and a Fresenius drying cylinder. Between the absorption apparatus and the aspirator, is also placed a washing-flask containing barium hydroxid solution, serving to detect any unabsorbed carbon dioxid. The layer of granular copper oxid is first heated, the air being slowly aspirated through the apparatus meanwhile, but not through the absorption bulbs. All the carbon dioxid is thus removed from the apparatus. The absorption system being connected, the tube is heated slowly from the front, backwards, and after the tube is well heated a slow current of air is drawn through and continued until the combustion is complete, which is usually in about three-quarters of an hour. After the tube is cool the powdered copper oxid and residue of combustion are removed, and for this reason the tube is stopped with a cork at both ends instead of being drawn out and sealed at one end. The tube can thus be refilled without disturbing the granular layer of copper oxid. The drying cylinder used between the combustion tube and the absorption system has its upper part filled with cotton to avoid the deleterious effects of the nitric oxid produced in the combustion. With this arrangement the use of metallic copper in the combustion tube to reduce the nitric oxid can be dispensed with, the moist cotton holding back the acid fumes. The per cent of humus is obtained by multiplying the per cent of carbon found by 1.724. =317. Method of Raulin for the Estimation of Humus.=[204]—The volumetric estimation of humus in soil by a solution of potassium permanganate would be convenient and practical if the combustion of the organic matter were complete, and if the browning of the liquor did not render the end of the reaction uncertain. The process of Schmidt, modified as below, has given satisfactory results. In a small flask, with flat bottom, containing about 250 cubic centimeters, are introduced ten cubic centimeters of a solution of manganese sulfate containing sixteen grams of the anhydrous salt per liter, and ten cubic centimeters of a ten per cent solution of potassium permanganate. The solution is heated for a few minutes, the liquor is decolorized and manganese bronze is precipitated. One hundred cubic centimeters of water are added, and four cubic centimeters of sulfuric acid containing 150 cubic centimeters of monohydrated acid per liter. There is now added an exactly measured volume of the humic liquid properly prepared, so that in oxidizing completely it destroys at most only half of the manganese dioxid. The mixture is submitted to gentle ebullition for eight hours, the water being kept at a constant volume. The excess of manganese dioxid remaining is dissolved hot by a measured portion of decinormal oxalic acid in slight excess, and the excess of oxalic acid is removed by a solution of potassium permanganate containing one gram per liter. The volume of oxalic acid not destroyed by manganese dioxid is calculated from the amount of permanganate consumed. The volume of oxalic acid, which corresponds to the same quantity of dioxid as the introduced humus, is also calculated by taking the difference between the volume of oxalic acid necessary to destroy all the dioxid formed by ten cubic centimeters of the ten per cent permanganate solution, and the volume of the oxalic acid which has destroyed the dioxid remaining after the action of the humus. The first volume of oxalic acid, that is to say, that which destroys the dioxid formed by ten cubic centimeters of ten per cent permanganate is determined in a preliminary titration. In regard to the humic liquor, it is prepared by treating ten grams of earth with soda solution in the usual manner. It will be easy to calculate the volume of the oxalic solution equivalent to the total volume of the humic solution, of which a determined fraction has been assayed, and consequently the volume of oxalic solution equivalent to the humus in ten grams of the dry earth. This number of cubic centimeters of the decinormal oxalic solution multiplied by 0.8 will express in milligrams the weight of oxygen necessary to burn the humus from ten grams of dry earth. Humus not being a definite compound, but a residue of complex organic matters partially oxidized, it will require as much more oxygen to complete the combustion as the previous oxidation has been less pronounced. This weight of oxygen necessary to burn the humus from ten grams of dry earth may serve to detect the total value as well as the weight of the humus itself. However, if we wish to have directly the weight of the humus, resource can be had to a table which, without being rigorous, can be regarded as sufficiently exact when the variability of the constitution of humus is taken into account. Volume of decinormal oxalic acid Corresponding humus, directly for ten grams of earth. determined. Cubic centimeters. Milligrams. 50 80 100 150 200 280 300 400 400 510 500 610 600 705 700 790 800 885 900 975 1,000 1,060 1,200 1,225 1,400 1,390 1,600 1,560 1,800 1,720 2,000 1,890 2,500 2,315 3,000 2,735 3,500 3,170 4,000 3,605 4,500 4,035 5,000 4,460 5,500 4,890 6,000 5,310 6,500 5,745 =318. Pasturel’s Method.=—According to Pasturel[205] the process of Raulin does not furnish figures that are rigorously exact only with soil of which the humus contains forty-five per cent of carbon. When the richness in organic carbon is less, the results of the estimation are too high. Pasturel modifies the process as follows: _Manganese Sulfate._—Dissolve sixteen grams of the pure anhydrous manganese sulfate in distilled water and make the solution up to one liter. _Potassium Permanganate._—Make a solution of ten grams of potassium permanganate in one liter of water; 100 cubic centimeters of the liquor just mentioned are diluted to one liter and constitute the potassium permanganate solution one to ten. _Oxalic and Sulfuric Acids._—A solution of oxalic acid is prepared containing 6.3 grams of the acid in one liter of water, and a dilute solution of sulfuric acid, by dissolving 150 grams of the monohydrated acid in one liter of water. _Humus Solution._—The solution of humus is prepared by the following process: Ten grams of fine earth are freed from all their carbonates by dilute hydrochloric acid. After washing, the filter is broken and the dirt is washed into a small flask. Not more than twenty or thirty cubic centimeters of water should be employed for this purpose. Twenty cubic centimeters of a liquor containing two grams of caustic soda are added, and the flask is placed upon a sand-bath and maintained at a boiling temperature for six hours. It is then diluted with water, filtered and washed as long as the waters are colored. The liquor is treated with dilute sulfuric acid until almost the whole of the soda is saturated. It is indispensable, however, to maintain a slight alkalinity in order that the organic matter may rest totally dissolved. The precipitation of silica which is almost always produced is without inconvenience. Afterward the volume is completed to 500 cubic centimeters and the humus solution is then ready for use. _Estimation of the Humus._—Ten cubic centimeters of the manganese sulfate are placed in a flask and ten cubic centimeters of the permanganate added, and the whole is then slightly heated, and afterward 100 cubic centimeters of water and four cubic centimeters of sulfuric acid are added. The humic liquor is now introduced in such proportion that the humus which it contains dissolves at the greatest, a half of the precipitated manganese and the rest of the process is continued as described by Raulin. =319. Estimation of Carbonates in Arable Soil.=—The principle of the determination depends on the liberation of the carbon dioxid from its compounds in the soil by acting on them with strong acid, and the desiccation, absorption, and weighing of the evolved gas. Any of the ordinary forms of apparatus for estimating carbon dioxid may be used in this determination. The apparatus of Knorr[206] has been used with satisfaction for many years in the laboratory of the Department of Agriculture. FIGURE 65. KNORR’S APPARATUS FOR THE DETERMINATION OF CARBON DIOXID. ] The apparatus consists of a flask A, Fig. 65, in which the carbon dioxid in the soil is liberated. A condenser, D, fits by means of a ground-glass joint into the neck of the flask in which the liberated gas, together with any air or aqueous vapor which may be carried forward, is cooled. This prevents any excess of vapor of water from entering the absorbing bulbs, which could easily happen at the end of the experiments when the contents of A are raised to the boiling point. The bulb B contains the acid, usually hydrochloric, which is employed for decomposing the carbonates. It is provided with a guard bulb-tube, C, which serves to absorb any carbon dioxid which might enter the apparatus with the air during aspiration at the close of the determination. The carbon dioxid is dried in the bulb-tube, E, in oil of vitriol, and absorbed in the potash solution in F. It is advisable to aspirate a slow current of air through the apparatus by means of the tube G during the whole of the operation. The quantity of the sample to be taken depends on its richness in carbonates. Many soils are so poor in carbonates as to render any attempt at exact determination nugatory. On the other hand, a comparatively small sample of marls will be sufficient. A preliminary qualitative test will indicate, in a general way, the quantity of the sample to be taken. The sample of soil, five to fifty grams, having been transferred to A, which should be perfectly dry, is made into a batter with freshly boiled distilled water. When all the parts of the apparatus are properly connected gas-tight, the cock between B and A is slowly opened and the hydrochloric (nitric) acid in B allowed to flow into A at such a rate as will secure a moderate evolution of gas. When the carbonate is entirely decomposed, a lamp is brought under A and its contents gradually raised to the boiling point. The aspiration of air, free from carbon dioxid, is meanwhile continued until all the liberated gas has been absorbed in F. Usually about fifteen minutes will be sufficient to accomplish this purpose. =320. Bernard’s Calcimeter.=—For a rapid and approximately accurate method of determining the amount of carbonate in the soil, estimated as calcium carbonate, Bernard makes use of the well-known method of the volumetric estimation of carbon dioxid. The sample to be examined should not be powdered in any way. The sample in a natural state, but well air-dried, is gently broken up by the fingers and passed through a sieve having ten meshes to the centimeter. Of the fine earth thus obtained, one gram is taken, for the determination. If the percentage of carbonate in the soil exceeds fifty then only half a gram is taken. FIGURE 66. BERNARD’S CALCIMETER. ] The apparatus employed is one well known. The small erlenmeyer C is fitted with a rubber stopper carrying an exit tube for the gas and a small thermometer. This flask is connected by means of a rubber tube and small glass tube to the measuring burette B. This burette is graduated from 0 to 100 cubic centimeters. Below, by means of a rubber tube, it is connected with the open bulb A, which, by means of a cord about its neck, can be suspended by the hook as shown in the figure. The measuring tube is filled with water through A until the level of the liquid in B is slightly above the zero mark. Meanwhile the one gram of earth has been placed in C, together with the tube D three-fourths filled with an equal mixture of water and strong hydrochloric acid. The greatest care must be taken that no part of the acid be spilled. The rubber stopper is now forced into C until the level of the water in B is just at the zero mark. Grasping C in the right hand and A in the left, the operator inclines C until the contents of D are emptied. Meanwhile as the gas is evolved, A is lowered at such a rate as to always keep the level of the water in B and A on the same plane. In a few moments the evolution of gas is complete, and the volume given off is read at once without correction. This volume multiplied by 0.4 gives the percentage of carbonate in the sample examined. It is understood that the determination is made at ordinary temperatures; _viz._, 17° to 22°. Example: One gram of a soil treated as above, gave of carbon dioxid (uncorrected) 65 cubic centimeters. 65 × 0.4 = 26.00 = per cent calcium carbonate in sample. The above method is useful in the classification of soils and in determining approximately the quantity of calcium carbonate which they contain. The practical use of this method is of great value in determining the character of fertilizer to be applied. It is well to know the percentage of carbonate in selecting mineral fertilizers. =321. Soils Deficient in Carbonates.=—When a soil contains but a small quantity of carbonates, Müller[207] has called attention to the fact that the carbon dioxid absorbed by the water in which the soil is rubbed up may vitiate the result. Instead of water a titrated solution of sodium carbonate is employed. The apparatus is composed of a flask containing the mixture of the sodium carbonate and the soil on which the hydrochloric acid is to act. The hydrochloric acid is contained in a small tube, as in Scheibler’s apparatus. The gas is received in a rubber tube 1.5 meters long and three to four millimeters interior diameter, and connected with a burette, the open mouth of which dips into the water of a cylinder of proper length. The volume of gas is read when the burette is raised or lowered in the cylinder until the liquid within and without stands at the same level. During the action of the acid on the carbonates the flask is constantly shaken. Several readings of the volume of gas are made, the evolution flask being vigorously shaken before each one. Finally, in order to allow for the variations in temperature and pressure of the exterior air which may take place between the beginning and the end of the reaction, a second flask containing air is placed by the side of the evolution flask and communicating with a narrow =ᥩ= tube half filled with water. Any variations in the volume of the air in the flask will be shown by variations in the height of the liquid in the two arms of the =ᥩ= tube, and the volume of the variation can be easily determined by having the =ᥩ= tube calibrated. If now _a_ equals the volume per cent of carbon dioxid in the atmosphere of the evolution flask at the end of the reaction, _v_ the volume of gas disengaged, and V the volume of the atmosphere in the evolution flask, the per cent of carbon dioxid contained in a given length of the rubber tube will be equal to _a_/2. This arises from the fact that the first gas which passes into the rubber tube is composed solely of air, while the last contains a per cent of carbon dioxid. By reason of the shaking of the flask the mean richness of the contents of the tube in carbon dioxid, will be sensibly _a_/2. From the above data the following equations are derived: 1. _v__a_/2 + V_a_ = _v_. 2. _a_ = _v_/(_v_/2 + V) If the weight of the carbon dioxid dissolved in V′ cubic centimeters of the liquid in the evolution flask be represented by _q_, the coefficient of the solubility of pure carbon dioxid in this liquid will be, according to the law of the solubility of a gas, equal to _k_ = (_q_)/(V′_a_) The volume of _k_ has been determined for various strengths of the sodium carbonate solution, using five cubic centimeters of hydrochloric acid containing 1.6 grams pure hydrochloric acid. For solutions disengaging from five to fifty milligrams of carbon dioxid, the mean value of _k_ was found to be 1.8 milligrams in the absence of calcium chlorid. When calcium chlorid was present in quantities varying from 0.03 to 0.07 gram per cubic centimeter of liquid in the evolution flask, the value of _k_ was 1.4 milligrams. By adopting, according to circumstances, the one or the other of the above numbers and multiplying it by V_a_, as determined by experiment, results are obtained differing only 0.2 to 0.3 milligram from those secured by direct weighing of the evolved gas. Dietrich[208] has called attention to the necessity of adding the volume of the dissolved gas to the measured volume in such determinations, and this volume or weight is easily determined by the above formulas. =322. Belgian Method.=—The method pursued at the Gembloux Station[209] consists in taking from five to fifty grams of the sample of soil, according to its content in carbonate, rubbing it up in a porcelain dish with distilled water in order to make a thin paste. The mass is worked to drive out all the air, the whole washed into a flask of 300 cubic centimeters capacity, and the amount of carbon dioxid estimated by setting free with an acid, and collecting the carbon dioxid evolved in potash bulbs. DIGESTION OF SOILS WITH SOLVENTS. =323. General Considerations.=—There are two points in connection with the determination of mineral matters in the soil which must always be kept in view; _viz._, first, the estimation of the total quantities of material in the soil, and second, the study of those materials which are more easily brought into solution and thus made available for the food of plants. It is well understood that the soil particles do not give up entirely to the plant the food materials which they contain. The practical value therefore of an analysis of a soil depends more upon the exact determination of the plant food available than upon its total quantity. From a mineral and geological point of view, on the other hand, an idea of the total composition of the soil is the object to be attained. For the determination of the available plant food, various solvents have been proposed, none of which, perhaps, imitates very accurately the natural solvent action of organic life and moisture on the soil materials. A description of the standard methods of preparing soil extracts will be the subject of a few succeeding paragraphs. =324. Estimation of the Quantity of Materials Soluble in Water.=[210]—Five hundred grams of the air-dried soil are treated in a flask with 1,500 cubic centimeters of water, less the quantity of water already contained in the air-dried soil, which is volatile at 125°. The mass is frequently shaken and, after seventy-two hours, 750 cubic centimeters of the liquid filtered. The filtrate is evaporated to dryness in a platinum dish, dried at 120° and weighed. This is then incinerated and, after treatment with ammonium carbonate and gentle ignition, is again weighed. The further examination of the residue for acids and bases is made by some of the methods hereafter described. =325. Treatment with Water Saturated with Carbon Dioxid.=—Two thousand five hundred grams of the air-dried soil are treated with 8000 cubic centimeters of distilled, and afterwards with 2000 cubic centimeters of water, which have previously, at room temperature, been saturated with carbon dioxid. The mixture is left in a closed flask for seven days, frequently shaken, after which 7,500 cubic centimeters of the liquid are filtered. The clear filtrate, after treatment with a little hydrochloric acid and a few drops of nitric acid, is evaporated to dryness. After the separation of the silica the traces of iron, alumina, lime, sulfuric acid, magnesia, potash, and soda, are estimated in the liquid in the manner hereinafter to be described. Phosphoric acid is always present in such a case, in such small quantities as to make its estimation unnecessary. =326. Treatment with Water Containing Ammonium Chlorid.=—In the flask containing the residue from the last experiment; _viz._, the soil with 2,500 cubic centimeters of liquid, are added 1,500 cubic centimeters of water saturated with carbon dioxid, and 8,000 cubic centimeters of pure water in which five grams of ammonium chlorid are dissolved. The mixture is then left for seven days, with frequent shaking, and 7,500 cubic centimeters of the liquid are then filtered, and the substances dissolved, determined in the filtrate. In addition to the usual quantities of lime and magnesia, from two to four times as much alkali is dissolved by this treatment as is found in the solution from the water containing carbon dioxid alone. =327. Treatment with Water Containing Acetic Acid.=—The acetic acid should be of such a strength that after it has fully acted on the soil it should still contain twenty per cent of free acid. 1000 grams of the soil dried at 100° are taken and the acid added in proper proportions and treated in the manner to be described for determining the solvent action of hydrochloric acid. =328. Treatment with Citric Acid Solution.=—In ascertaining the quantities of soil materials soluble in a solution of citric acid, Dyer[211] recommends the use of a carefully prepared citric acid solution. The digestion is carried on as follows: Place in a flask or bottle, holding about three liters, 200 grams of air-dried soil and two liters of distilled water, in which are dissolved twenty grams of pure citric acid. The soil is left, at room temperature, in contact with the one per cent acid for seven days, with thorough shaking several times a day. At the end of the digestion the solution is filtered and 500 cubic centimeters of the filtrate, corresponding to fifty grams of the soil, are taken for analysis for each ingredient to be determined. The digestion in citric acid is especially recommended by Dyer because of its supposed near resemblance to the methods of solution of plant food practiced by the rootlets of plants. It is evident, however, that this process is in no sense an imitation of natural methods. The solution is to be used exclusively for the estimation of potash and phosphoric acid. Dyer concludes, from a comparison of the action of a solution of citric acid on soils of known fertility, that when as little as 0.01 per cent of phosphoric acid is dissolved from a soil by this treatment it is justifiable to assume that it stands in immediate need of phosphatic manure. The methods used by Dyer to determine the phosphoric acid and potash in the citric acid solution will be given in their appropriate place. =329. Treatment with Hydrochloric Acid.=—The solutions of soils usually subjected to chemical analysis are those obtained by long treatment with hot mineral acids, among which the most common is hydrochloric. It has long been assumed by soil analysts, perhaps not with justness, that such treatment removed from the soil, all those elements of plant food which could possibly be available for the needs of the growing crop. In this connection, however, the analyst must not forget that nature, in a series of years, with her own methods may easily accomplish what he in five days, even with the help of a hot mineral acid, may not be able to secure. Since, however, this method of solution has been so long practiced it is not the place here to throw doubt on its effectiveness without being able to suggest a better way. Of the mineral acids available no one possesses solvent powers for soils in a higher degree than hydrochloric. A somewhat detailed description will therefore be given of the methods of its use. =330. Strength of Acid to be Employed.=—The fact that hydrochloric acid of nearly constant strength; _viz._, specific gravity 1.115, equivalent to 22.9 per cent hydrochloric acid, may be obtained by distillation, led Owen to use acid of this density in his classic work on soil analysis. Hilgard has lately reviewed the conditions of constant strength in the solvent with results confirming the statements of Owen.[212] He evaporated on a steam-bath, to one-half its bulk, fifty cubic centimeters of hydrochloric acid, specific gravity 1.116, obtained by using the distillate from a stronger acid after rejecting the first third. The same operation was conducted with similar acid diluted with ten per cent of water. The acid used contained 22.96 per cent hydrochloric acid. The residual acid contained 21.49 per cent hydrochloric acid. These results lead Hilgard to believe that the changes arising from evaporation in hydrochloric acid during soil digestion are insignificant, compared with those due to its action on the soluble matters, and that evaporation during digestion is effective in maintaining a definite strength in the solvent. For this reason it is contended that evaporation in a porcelain beaker covered by a watch-glass is more effective in constancy of conditions than digestion in a closed flask under pressure. =331. Influence of Time of Digestion and Strength of Acid.=—Loughridge has made an interesting study of the influence of the strength of acid and time of digestion on the extraction of soils.[213] The method of preparing the soil for the determination of the above points is as follows: The soil, having been passed through the appropriate number of sieves to obtain the fine earth is pulverized with a wooden pestle and thoroughly mixed. The hygroscopic moisture is determined, after exposing it in a place saturated with vapor, in a layer not exceeding one millimeter in thickness for twelve hours, and subsequently drying at 200° in a paraffin-bath. Of this dried substance, from two to three grams are used in the general analysis, the methods employed being in general those adopted by Peter.[214] The quantities of materials dissolved by acids of different densities are shown below. The determinations were made by methods hereafter to be described. Specific gravity of acid. Ingredients. 1.00 1.115 1.160 Insoluble residue 71.88 70.53 74.15 Soluble silica 11.38 12.30 9.42 Potash 0.60 0.63 0.48 Soda 0.13 0.09 0.35 Lime 0.27 0.27 0.23 Magnesia 0.45 0.45 0.45 Manganese oxid 0.06 0.06 0.06 Ferric oxid 5.15 5.11 5.04 Alumina 6.84 8.09 6.22 Sulfuric acid 0.02 0.02 0.02 Volatile matter 3.14 3.14 3.14 —————— —————— ————— Total 100.02 100.69 99.29 Amount of soluble matter 24.00 27.02 22.27 „ „ „ bases 13.50 14.70 12.83 From the above table it is seen that the strongest acid exerts the least soluble effect upon the substances present in the soil, while the greatest degree of solution was obtained by the acid of 1.115 specific gravity. This result indicates that while lime and magnesia are probably present chiefly as carbonates, potash as well as alumina, and to some extent lime, are present as silicates, and for that reason are not as fully extracted by acid of low strength as by that of medium concentration. In regard to the influence of the time of digestion, the acid of specific gravity 1.115 being used, the data obtained are given in the following table: Number of days digested. Ingredients. 1. 3. 4. 5. 10. Insoluble residue 76.97 72.66 71.86 70.53 71.79 Soluble silica 8.60 11.18 11.64 12.30 10.96 Potash 0.35 0.44 0.57 0.63 0.62 Soda 0.06 0.06 0.03 0.09 0.28 Lime 0.26 0.29 0.28 0.27 0.27 Magnesia 0.42 0.44 0.47 0.45 0.44 Manganese oxid 0.04 .06 0.06 0.06 0.06 Ferric oxid 4.77 5.01 5.43 5.11 4.85 Alumina 5.15 7.38 7.07 7.88 7.16 Phosphoric acid 0.21 0.21 Sulfuric acid 0.02 0.02 0.02 0.02 0.02 Volatile matter 3.14 3.14 3.14 3.14 3.14 ————— —————— —————— —————— ————— Total 99.63 100.68 100.55 100.69 99.80 Amount of soluble matter 19.67 24.88 25.57 27.02 24.87 „ „ „ bases 11.05 13.68 13.91 14.49 13.68 From this table it appears that the amount of dissolved ingredients increases up to the fifth day, the increase becoming, however, very slow as that limit is approached. It is also found that the ingredients offering the greatest resistance to this action are the same as those whose amounts were sensibly affected by the strength of the acid; namely, silica, potash, and alumina. In regard to lime and magnesia, one day’s digestion not being sufficient for full extraction, it is evident that they do not exist in the soil as carbonates or hydric oxids only, as has been supposed, but also as silicates. A comparison of the results of the five and ten days’ digestion shows that the solvent action of the acid has substantially ceased at the end of five days, there being no further increase of the amount of dissolved matter. =332. Digestion Vessels.=—Hilgard prescribes that the digestion of the sample of soil with acid be conducted in a small porcelain beaker covered with a watch-glass.[215] Kedzie, however, prefers beakers of bohemian glass, and shows that hydrochloric acid attacks the porcelain with greater energy than the glass.[216] Platinum would be the ideal material for the digestive vessels, but its great cost would exclude its general use. In most cases it will be found that the error introduced into the analysis by the use of porcelain or bohemian glass beakers is quite small and not likely to affect the quantitative estimation of soluble soil ingredients to any extent. In this laboratory some comparative tests made by Mr. W. D. Bigelow have shown that vessels of hard glass of special manufacture are less soluble in hot hydrochloric acid of 1.115 specific gravity than porcelain, thus confirming the observation of Kedzie. Following are the data showing the weights of material dissolved in fifty hours: Berlin porcelain 2.8 milligrams Bohemian glass 1.7 „ Kaehler and Martini glass 1.2 „ In each case twenty-five cubic centimeters of the acid were used. The vessels all had approximately a capacity of 200 cubic centimeters. =333. Processes Employed—Hilgard’s Method.=—The sample of soil sifted through a 0.5 millimeter mesh sieve and thoroughly air-dried, is conveniently preserved in weighing tubes. The actual content of hygroscopic and combined moisture may be previously made on a separate sample of soil. In determining the amount of material to be employed for the general analysis regard must be had to the nature of the soil. This is necessary because of the impracticability of handling successfully such large precipitates of alumina as would result from the employment of as much as five grams in the case of calcareous clay soils; while in the case of very sandy soils even that quantity might require to be doubled in order to obtain weighable amounts of certain ingredients. For soils in which the insoluble portion ranges from sixty to eighty per cent, two and a half to three grams are about the right measure for general analysis, while for the phosphoric acid determination not less than three grams should be employed in any case. It has been alleged that larger quantities must be taken for analysis in order to secure average results. It is difficult to see why this should be true for soils and not for ores, in which the results affect directly the money value, while in the case of soils the interpretation of results allows much wider limits in the percentages. Correct sampling must be presupposed to make any analysis useful; but with modern balances and methods it is difficult to see why five grams should be employed instead of half that amount, which in some cases is still too much for convenient manipulation of certain precipitates. The weighed quantity, usually of two to two and a half grams, is brought into a small porcelain beaker, covered with a watch-glass, treated with eight to ten times its bulk of hydrochloric acid of 1.115 specific gravity, and two or three drops of nitric acid, and digested for five days over the laboratory steam-bath. At the end of this time it is evaporated to dryness, first on the water-bath and then on the sand-bath. By this treatment all the silica set free is rendered insoluble. =334. Provisional Method of the Official Agricultural Chemists.=—Place ten grams of the air-dried soil in a round bottom 150 to 200 cubic centimeter bohemian flask, add 100 cubic centimeters of pure hydrochloric acid of specific gravity 1.115, insert the stopper, wire it securely, place in a steam-bath, and digest for thirty-six hours at the temperature of boiling water. Pour the contents of the flask into a small beaker, wash with distilled water, add the washings to the contents of the beaker and filter through a washed filter. The residue is the amount insoluble in hydrochloric acid. Add a few drops of nitric acid to the filtrate, and evaporate to dryness on the water-bath; take up with hot water and a few drops of hydrochloric acid, and again evaporate to complete dryness. Take up as before, and filter into a liter-flask, washing with hot water. Cool and make up to the mark. This is solution A. The residue represents the silica originally dissolved. In comparing the two preceding methods it is found that the former; _viz._, digestion in flasks covered only with a watch-glass gives a larger quantity of dissolved matter in five days than the digestion under pressure does in thirty-six hours. In comparative tests in this laboratory made by Mr. W. D. Bigelow the respective quantities of soluble and insoluble matter obtained by the two methods in two soils are as follows: Soil No. 1. Soil No. 2. Per cent. Per cent. Method of Digestion. Insoluble. Soluble. Insoluble. Soluble. Open flask 75.62 24.38 79.62 20.38 Closed flask 76.81 23.19 80.48 19.52 =335. The German Station Method.=—The method recommended by the German Stations[217] is greatly different from that described above, both in temperature and time of digestion. To one part of the soil are added two parts by volume of a twenty-five per cent hydrochloric acid solution, the quantity being increased to correspond to any excess of carbonates. The mixture is left for forty-eight hours with frequent shaking. As an alternate method, one part of soil is treated with two parts by volume of ten per cent hydrochloric acid, and heated on the water-bath, with frequent shaking, for three hours. The soluble materials are determined in the filtrate by some of the methods usually employed. =336. The Gembloux Method.=—The method of making the acid extract of the soil at the Gembloux Station does not differ greatly from some of those already described. The quantity of air-dried material taken is such that it may weigh exactly 300 grams exclusive of the moisture which it contains. It is dried at 150° for at least six hours. The drying is necessary in order to obtain an extract in hydrochloric acid of exactly 1.18 specific gravity. The dry earth is placed in a flask of two or three liters capacity to which one liter of hydrochloric acid of 1.18 specific gravity is added, being careful to take precautions to prevent frothing if much carbonate be present. The acid is allowed to act for twenty-four hours, it being frequently shaken meanwhile. After settling it is decanted and filtered upon a double folded filter, the apex of which rests upon a small funnel covered with a plain filter of strong paper. Five hundred cubic centimeters of the filtrate are taken for the estimation, and in this filtrate are estimated the silica, phosphoric and sulfuric acids, potash, soda, iron, alumina, lime, and magnesia. The filtrate is evaporated to dryness in a porcelain capsule, a few drops of nitric acid added and the liquid kept well stirred. The residue should be taken up with water, and if not perfectly bright a second and even a third evaporation with nitric acid should take place, until all the organic matter is destroyed, which will be indicated by the clear yellow or reddish-yellow color of the liquid, caused by the iron oxid. After the last evaporation the material is dried in a drying oven one hour at 110°. =337. Treatment with Cold Hydrochloric Acid.=—According to the digestion method of Wolff[218] the soil sample is treated with cold concentrated hydrochloric acid. The process is as follows: Four hundred and fifty grams of the soil dried at 100° are placed in a glass flask and treated with 1,500 cubic centimeters of hydrochloric acid of 1.15 specific gravity, corresponding to thirty per cent of gaseous hydrochloric acid. For every five per cent of calcium carbonate which the soil may contain, an additional fifty cubic centimeters of hydrochloric acid are added. With frequent stirring, the soil is left in contact with the acid for forty-eight hours and then 1,000 cubic centimeters of liquid, as clear as possible, are poured off, which corresponds to 300 grams of the soil. After dilution with water it is filtered and the filtrate treated with a few drops of nitric acid and evaporated to dryness. After the separation of the silica the solution is again made up with water to 1,000 cubic centimeters. Two hundred cubic centimeters of this solution, corresponding to sixty grams of the soil, are taken for the estimation of iron, alumina, lime, manganese, and magnesia. Four hundred cubic centimeters of the solution, corresponding to 120 grams of the soil, are left for the estimation of sulfuric acid and alkalies. This method gives from five to six times less alkalies and a much smaller quantity of iron than the treatment with hot acid. In the use of hot acid, therefore, Wolff reduces the quantity of soil acted on to 150 grams. =338. Treatment with Nitric Acid.=—For the purpose of estimating phosphoric acid Grandeau[219] directs that the soil be extracted with nitric acid. For this purpose 100 grams of the air-dried fine earth are placed in a bohemian flask and treated cautiously with nitric acid in small quantities at a time. If the soil be calcareous in its nature it should be previously moistened with water, and the acid so added as to avoid undue effervescence, the flask being inclined during the operation. Sufficient acid is added to strongly saturate the sample and it is then digested on the sand-bath for two hours; or at least until the organic matters are destroyed, which will be indicated by the cessation of evolution of nitrous vapors. When the supernatant liquid has become clear it is decanted. The residue is washed with distilled water and separated on a filter, and washed until the wash-water is colorless. The decanted portion is united with the filtrate and the whole made up to a volume of one liter. The determinations are made in portions of 200 cubic centimeters each. =339. Digestion with Hydrofluoric and Sulfuric Acids.=—When a complete disintegration of the siliceous substances in soils is desired as in analysis in bulk, the decomposition is easily accomplished by digestion with the above named acids in a platinum dish. The fine earth is saturated with a concentrated aqueous solution of hydrofluoric acid to which a few drops of sulfuric acid are added. It is then digested until nearly dry. If any undecomposed particles remain, the treatment is continued until complete decomposition is secured. The silica is thus all volatilized as hydrofluosilicic acid and the bases pre-existing in the soil are left as sulfates. This method of treatment is especially recommended when it is desired to estimate the whole quantity of any of the soil constituents with the exception of silica. The silica may, however, be determined in the distillate. Instead of using the solution of hydrofluoric acid, ammonium fluorid may be employed. In this process the sample of earth reduced to an impalpable powder by grinding in an agate mortar is mixed with four or five times its weight of the ammonium fluorid in a platinum dish and thoroughly moistened with sulfuric acid and allowed to stand at room temperature for several hours. It is then gently heated until all fumes of hydrofluosilicic acid have been driven off, but is not raised to a red heat. If any undecomposed particles remain, the above treatment is repeated. DETERMINATION OF THE QUANTITY OF DISSOLVED MATTER. =340. Substances in Solution.=—By treatment with solvents as indicated in the preceding paragraphs, greater or less quantities of the original constituents of soil are brought into solution. The total quantity of dissolved matters is determined by drying and weighing the insoluble residue and the percentages of soluble and insoluble matters should be noted; and each portion saved for further examination. In this country the common practice of soil analysis is to digest the sample with hydrochloric acid. The following paragraphs, therefore, will be devoted to the general methods of determining the matters dissolved by that treatment, leaving for later consideration the special methods of analysis. The fundamental principle on which the treatment with hydrochloric acid rests is based on the belief that such treatment practically extracts from the soil all those elements which are likely to become, immediately or in the near future, available for plant food. =341. Provisional Methods of the Official Agricultural Chemists.=[220]—(1) _The Analytical Operations_ are conducted with solution A, paragraph =334=. (2) _Ferric Oxid, Alumina, and Phosphoric Acid._—To 100 or 200 cubic centimeters, according to the probable amount of iron present, of the solution A, add ammonium hydroxid to alkaline reaction to precipitate ferric and aluminum oxids and phosphates. Expel the excess of ammonia by boiling, allow to settle, decant the clear solution through a filter; add to the flask fifty cubic centimeters of hot distilled water, boil, settle, and decant as before. After pouring off all the clear solution possible, dissolve the residue with a few drops of warm hydrochloric acid and add just enough ammonium hydroxid to precipitate the oxids. Wash by decantation with fifty cubic centimeters of distilled water, and then transfer all the precipitate to the filter and wash with hot distilled water till the filtrate becomes free from chlorids. Save the filtrate and washings which form solution B. Dry the filter and precipitate at 110°, transfer the precipitate to a tared platinum crucible, burn the filter and add the ash to the precipitate, heat the whole red hot, cool in a desiccator, and weigh. The increase of weight, minus the ash of filter and the phosphoric acid (found in a separate process), represents the weight of the ferric and aluminum oxids. (3) _Ferric Oxid._—Precipitate 100 cubic centimeters of solution A, as under (2), except that only one precipitation is made; wash with hot water; dissolve in dilute sulfuric acid; reduce with zinc and estimate as ferrous oxid by a standard solution of potassium permanganate. To prepare the potassium permanganate solution, dissolve 3.156 grams of pure crystallized potassium permanganate in 1,000 cubic centimeters of distilled water, and preserve in a glass-stoppered bottle, shielded from the light. Standardize this solution with pure ferrous sulfate, ammonium ferrous sulfate or oxalic acid. (4) _Alumina._—The calculated weight of ferric oxid deducted from that of ferric oxid and alumina with corrections for filter ash and phosphoric acid, will give the weight of alumina in two grams of air-dried soil. (5) _Phosphoric Acid._—This may be estimated in the above iron solution, if the soil is sufficiently rich, by the molybdate method, given under fertilizers; or if the quantity of soil represented in the iron solution is not sufficient, a fresh portion of solution A may be taken, and the phosphoric acid determined directly by the molybdate method. (6) _Manganese._—Concentrate the filtrate and washings (solution B) to 200 cubic centimeters or less; add ammonium hydroxid to alkalinity; add bromin water and heat to boiling, keeping the beaker covered with a watch-glass; as the bromin escapes, the beaker is allowed to cool somewhat, ammonia and bromin water again added, and heated as before. This process is continued until the manganese is completely precipitated, which requires from thirty to sixty minutes, and the solution filtered while still warm; the precipitate is washed, dried, ignited and weighed; estimate as manganese protosesquioxid. (7) _Lime._—If no manganese is precipitated, add to solution B, or the filtrate and washings from (6) twenty cubic centimeters of a strong solution of ammonium chlorid and forty cubic centimeters of saturated solution of ammonium oxalate to completely precipitate all the lime as oxalate and convert the magnesia into soluble magnesium oxalate. Heat to boiling and let stand for six hours till the calcium oxalate settles clear, decant the clear solution on a filter, pour fifty cubic centimeters of hot distilled water on the precipitate and again decant the clear solution on the filter, transfer the precipitate to the filter, and wash it free from all traces of oxalates and chlorids. Dry and ignite the precipitate over the blast-lamp until it ceases to lose weight, weigh and estimate as calcium oxid; carefully moisten with sulfuric acid, heat the inclined covered crucible gently to avoid loss, then intensely, and weigh as calcium sulfate. (8) _Magnesia._—Concentrate the filtrate and washings (from 7) to 200 cubic centimeters, place in a half-liter erlenmeyer, add thirty cubic centimeters of a saturated solution of sodium phosphate and twenty cubic centimeters of concentrated ammonium hydroxid, cork the flask, and shake violently at intervals of a few minutes till crystals form, then set the flask in a cool place for twelve hours. Filter the clear liquid through a tared gooch, transfer the precipitate to the filter, and wash with dilute ammonium hydroxid (1 : 3) till the filtrate is free from phosphates; dry and ignite the crucible, at first gently and then intensely, to form magnesium pyrophosphate. The increase of weight × 0.36024 = MgO. By using an erlenmeyer free from scratches and marks, and shaking violently instead of stirring with a glass rod, the danger is almost entirely avoided of crystals adhering to the sides of the vessel; but if crystals do adhere they are readily removed by a rubber-tipped glass rod. (9) _Sulfuric Acid._—Evaporate 200 cubic centimeters of solution A (1) nearly to dryness on a water-bath to expel the excess of acid; then add 100 cubic centimeters of distilled water, heat to boiling and add ten cubic centimeters of a solution of barium chlorid, and continue the boiling for five minutes. When the precipitate has settled, pour the clear liquid on a tared gooch, treat the precipitate with fifty cubic centimeters of boiling water, and transfer the precipitate to the filter and wash with boiling water till the filtrate is free from chlorids. Dry the filter and ignite strongly. The increase in weight is barium sulfate, which multiplied by 0.34331 = SO₃ in two grams of air-dried soil. (10) _Potash and Soda._—To another portion of 200 cubic centimeters of solution A, add barium chlorid in slight excess, and make alkaline with ammonia to precipitate sulfuric and phosphoric acids, ferric oxid, etc. Then precipitate the calcium and barium by ammonium oxalate. Evaporate the filtrate and washings to dryness, heat to a low red heat to decompose oxalates and expel ammonia salts, dissolve in twenty-five cubic centimeters of distilled water, filter and wash the precipitate; add to the filtrate and washings ten cubic centimeters of baryta water, and digest for an hour. Filter and wash the precipitate, add ammonium carbonate to the filtrate to complete precipitation of baryta, filter and wash this precipitate. Evaporate the filtrate and washings in a tared platinum dish, gently ignite the residue to expel ammonia salts, cool and weigh. The increase of weight represents the potassium and sodium chlorids in two grams of air-dried soil. =342. Hilgard’s Methods.=[221]—(1) _Soluble Silica._— The acid filtrate obtained by the process given in paragraph =333= is employed for the following determinations. After the solution obtained has been evaporated to dryness to render silica insoluble, it is moistened with strong hydrochloric acid and two or three drops of nitric acid. The mass is warmed, and after allowing to stand for a few hours on a steam-bath is taken up with distilled water. After clearing, it is filtered from the insoluble residue, which is strongly ignited and weighed. If the filtrate should be turbid the insoluble residue which has gone through the filter can be recovered in the iron and alumina determination. The insoluble residue is next boiled for fifteen or twenty minutes in a concentrated solution of sodium carbonate, to which a few drops of caustic lye should then be added to prevent reprecipitation of the dissolved silica. The solution must be filtered hot. The difference between the weight of the total residue and that of undissolved sand and mineral powder is recorded as soluble silica, being the aggregate of that set free by the acid treatment and that previously existing in the soil. The latter, however, rarely reaches five per cent. (2) _Destruction of Organic Matter._—The acid filtrate from the total insoluble residue is evaporated to a convenient bulk. In case the filtrate should indicate by its color, the presence of any organic matter, it should be oxidized by aqua regia, otherwise there will be difficulty in separating alumina. (3) _Precipitation of Iron and Alumina._—The filtrate thus prepared is now brought to boiling and treated sparingly with ammonia, whereby iron and alumina are precipitated. It is kept boiling until the excess of ammonia is driven off, and then filtered hot. (Filtrate A.) The previous addition of ammonium chlorid is usually unnecessary. If the boiling is continued too long, filtration becomes very difficult and a part of the precipitate may redissolve in washing. Filtration may be begun as soon as the nose fails to note the presence of free ammonia; test paper is too delicate. Failure to boil long enough involves the contamination of the iron-alumina precipitate with lime and manganese. (4) _Estimation of Iron and Alumina._—The iron and alumina precipitate with filter of (3) is dissolved in a mixture of about five cubic centimeters of hydrochloric acid and twenty cubic centimeters of water. Then filter and make up to 150 cubic centimeters. Take fifty cubic centimeters for the determination of iron and alumina together by precipitation with ammonia, after oxidizing the organic matter (filter) with aqua regia; also fifty cubic centimeters for iron alone; keep fifty cubic centimeters in reserve. Determine the iron by means of a standard solution of potassium permanganate after reduction; this latter is done by evaporating the fifty cubic centimeters almost to dryness with strong sulfuric acid, adding water and transferring the solution to a flask, and then reducing by means of pure metallic zinc in the usual way. The alumina is then determined by difference. This method of determining the two oxids in their intermixture is in several respects more satisfactory than the separation with alkaline lye, which, however, has served for most determinations made, until within the last ten years. It is, however, much more liable to miscarry in unpracticed hands than the other. (5) _Estimation of Lime._—The filtrate A from iron and alumina is acidified slightly with hydrochloric acid, and if too bulky is evaporated to about twenty-five cubic centimeters, unless the soil is a very calcareous one, and the lime is precipitated from it by neutralizing with ammonia and adding ammonium oxalate. The precipitation of the lime should be done in the hot solution, as the precipitate settles much more easily. It is allowed to stand for twelve hours, then filtered (filtrate B), washed with cold water, and dried. By ignition the lime precipitate is partially converted into the oxid. It is then heated with excess of powdered ammonium carbonate, moistened with water, and exposed to a gentle heat (50°–80°) until all the ammonia is expelled. It is then dried below red heat and weighed as calcium carbonate. When the amount of lime is at all considerable, the treatment with ammonium carbonate must be repeated till a constant weight is obtained. (6) _Estimation of Sulfuric Arid._—The filtrate B from the calcium oxalate is put into a bohemian flask, boiled down over the sand-bath, and the ammoniacal salts destroyed with aqua regia. From the flask it is removed to a small beaker and evaporated to dryness with excess of nitric acid. This process usually occupies four to five hours. The residue should be crystalline-granular; if white-opaque, ammonium nitrate remains and must be destroyed by hydrochloric acid. The dry residue is now moistened with nitric acid, and the floccules of silica usually present separated by filtration from the filtrate, which should not amount to more than ten or fifteen cubic centimeters; sulfur trioxid is then precipitated by treatment with a few drops of barium nitrate, both the solution and the reagent being heated to boiling. If the quantity of sulfuric acid is large it may be filtered after the lapse of four or five hours (filtrate C). If very small let it stand twelve hours. The precipitate is washed with boiling water, dried, ignited, and weighed. Care should be taken in adding the barium nitrate to use only the least possible excess, because in such a small concentrated acid solution the excess of barium nitrate may crystallize and will not readily dissolve in hot water. Care must also be taken not to leave in the beaker the large heavy crystals of barium sulfate, of which a few sometimes constitute the entire precipitate, rarely exceeding a few milligrams. Should the ignited precipitate show an alkaline reaction on moistening with water, it must be treated with a drop of hydrochloric acid, refiltered and weighed. The use of barium acetate involves unnecessary trouble in this determination. (7) _Estimation of Sodium and Potassium._—Filtrate C is now evaporated to dryness in a platinum dish; the residue is treated with an excess of crystallized oxalic acid, moistened with water, and exposed to gentle heat. It is then strongly ignited to change the oxalates to carbonates. This treatment with oxalic acid must be made in a vessel which can be kept well covered, otherwise there is danger of loss through spattering. As little water as possible should be used, as otherwise loss from evolution of carbon dioxid is difficult to avoid. Spatters on the cover should not be washed back into the basin until after the excess of oxalic acid has been volatilized. The ignited mass should have a slightly blackish tinge to prove the conversion of the nitrates into carbonates. White portions may be locally retreated with oxalic acid. The ignited mass is treated with a small amount of water, which dissolves the alkaline carbonates and leaves the magnesium carbonate, manganese protosesquioxid, and the excess of barium carbonate behind. The alkalies are separated by filtration into a small platinum dish (filtrate D), and the residue is well but sparingly washed with water on a small filter. When the filtrate exceeds ten cubic centimeters it may, on evaporation, show so much turbidity from dissolved earthy carbonates as to render refiltration on a small filter necessary, since otherwise the soda percentage will be found too large and magnesia too small. If, on dissolving the ignited mass, the solution should appear greenish from the formation of alkaline manganates, add a few drops of alcohol to reduce the manganese to insoluble dioxid. The residue of barium, magnesium, and manganese compounds is treated on the filter with hydrochloric acid, and the platinum dish is washed with warm nitric acid (not hydrochloric, for the platinum dish may be attacked by chlorin from the manganese oxid) dissolving any small traces of precipitate that may have been left behind. The filtrate D, which should not be more than ten or fifteen cubic centimeters, containing the carbonates of the alkalies, is evaporated to dryness and gently fused, so as to render insoluble any magnesium carbonate that may have gone through; then redissolved and filtered into a small weighed platinum dish containing a few drops of dilute hydrochloric acid, to change the carbonates into chlorids; evaporated to dryness, exposed to a gradually rising temperature (below red heat), by which the chlorids are thoroughly dried and freed from moisture, so as to prevent the decrepitation that would otherwise occur on ignition. Then, holding the platinum basin firmly by forceps grasping the clean edge, pass it carefully over a very low bunsen flame, so as to cause, successively, every portion of the scaly or powdery residue to collapse, without fully fusing. There is thus no loss from volatilization, and no difficulty in obtaining an accurate, constant weight. The weighed chlorids are washed by means of a little water into a small beaker or porcelain dish, treated with a sufficient quantity of platinum chlorid, and evaporated to dryness over the water-bath. The dried residue is treated with a mixture of three parts absolute alcohol and one part ether, leaving the potassium platinochlorid undissolved. This is put on a filter, and washed with ether-alcohol. When dried, the precipitate and filter are put into a small platinum crucible and exposed to a heat sufficiently intense to reduce the platinum chlorid to metallic platinum and to volatilize the greater part of the potassium chlorid. This is easily accomplished in a small crucible, which is roughened by being constantly used for the same purpose (and no other), the spongy metal causing a ready evolution of the gases. The reduced platinum is now first washed in the crucible with hot acidulated water, then with pure water; then all moisture is driven off and it is weighed. From the weight of the platinum, is calculated the potassium chlorid and the oxid corresponding; the difference between the weights of the total alkaline chlorids and potassium chlorid gives the sodium chlorid, from which may be calculated the sodium oxid. When the heating of the platinum precipitate has not been sufficient in time or intensity, instead of being in a solid spongy mass of the color of the crucible itself, small black particles of metallic platinum will obstinately float on the surface of the water in the crucible, and it becomes difficult to wash without loss. (8) _Estimation of Manganese._—The solution containing the magnesium and manganese chlorids is freed from barium salts by hot precipitation with sulfuric acid, and the barium sulfate, after settling a few hours, is separated by filtration. The filtrate is neutralized with ammonia, any resulting small precipitate (of iron) is filtered, and the manganese precipitated with ammonium sulfid, let stand twelve hours and filtered (filtrate E); wash with cold water, dry, ignite, and weigh as manganese protosesquioxid, Mn₃O₄. If preferred the manganese may be precipitated with chlorin or bromin water as dioxid; but the process requires a rather longer time and may fail in inexpert hands more readily than the other. (9) _Estimation of Magnesium._—The filtrate E from the manganese is now freed from sulfur by acidulating with hydrochloric acid, evaporating, if necessary, and filtering. From the filtrate the magnesia is precipitated by adding an equal bulk of ammonia water and then sodium phosphate. After standing at least twenty-four hours, the magnesium salt may be filtered, washed with ammoniacal water, dried, ignited, and weighed as magnesium pyrophosphate. =343. Examination of Acid Extract by the Methods of Petermann.=—_Estimation of the Silica._—The Gembloux method of estimating silica consists in taking up the dry extract obtained from the treatment of the earth, in the manner described in paragraph =336=, with water and a few drops of hydrochloric acid, heating for a short time on a sand-bath to facilitate the solution, and filtering, washing, drying, igniting, and weighing the residue obtained as silica. _Estimation of the Sulfuric Acid._—The method employed consists in heating the filtrate obtained in the estimation of silica for half an hour with a few drops of nitric acid and making the volume up to 500 cubic centimeters. One hundred cubic centimeters of this are precipitated with barium chlorid, diluted to double its volume, heated for some time, the precipitate of barium sulfate collected and weighed, and the quantity of sulfuric acid calculated therefrom. _Potash and Soda._—Potash and soda are estimated at the Gembloux Station by heating the filtrate obtained in the estimation of the sulfuric acid and precipitating the excess of barium in the hot solution after the addition of ammonia by ammonium oxalate and carbonate. The whole is allowed to digest for six hours at a gentle heat and then allowed to remain at rest for twenty-four hours, filtered, washed, and the filtrate evaporated to dryness in a large platinum dish and the ammoniacal salts driven off at a low temperature. At the end, the temperature is carried a little higher until it reaches low redness. The residue is taken up by distilled water, filtered into a weighed platinum dish, a few drops of hydrochloric acid added, evaporated, dried, heated with great care and the sodium and potassium chlorids obtained weighed together. The respective quantities of potash and soda in the earth are estimated in the usual way by precipitating the potash with platinum chlorid. _Estimation of the Iron and Aluminum Oxids._—The iron and aluminum oxids are estimated by taking twenty-five cubic centimeters of the primitive solution obtained with hydrochloric acid and adding ammonium carbonate almost to complete neutralization, that is to say until the precipitate formed is just redissolved in the feeble excess of hydrochloric acid which remains. Dilute with distilled water and precipitate with a little excess of ammonium acetate, and boil for a moment; after boiling, the basic iron and aluminum acetate and the small quantity of iron and aluminum phosphate present are easily deposited, and the supernatant liquid should be completely limpid and colorless. Wash the precipitate by decantation, boiling each time, filter, wash the filter with boiling water to which a little ammonium acetate has been added, dry, ignite, and weigh. The material obtained consists of ferric oxid, aluminum oxid, and iron and aluminum phosphates. Deduct from the whole, the phosphoric acid determined in another portion. The residue will be the sum of the iron and aluminum oxids. _Estimation of the Lime._—The filtrate from the portion used for the estimation of the iron and alumina is treated with ammonium oxalate. The mixture is kept at a low temperature for at least twelve hours, after which it is filtered, washed with hot water, dried, and ignited over a blast-lamp to constant weight and weighed as calcium oxid. _Estimation of the Magnesia._—For the estimation of the magnesia the filtrate obtained in the estimation of lime is evaporated to dryness in a platinum dish, the ammoniacal salts driven off, the residue taken up with water slightly acidified with hydrochloric acid, filtered, the filtrate saturated with ammonia and heated some time to the boiling point to precipitate any traces of iron and alumina which may have remained in solution. Filter, wash, allow to cool and precipitate the magnesia by the addition of sodium phosphate. It is then allowed to stand for twelve hours, collected on a filter, ignited, and weighed as pyrophosphate, and the quantity of magnesia calculated from the weight of salt obtained. _Estimation of the Phosphoric Acid._—The phosphoric acid is estimated by taking 100 cubic centimeters of the original solution obtained by the treatment of the soil with hydrochloric acid and evaporating it to dryness on the water-bath. The residue is taken up with water to which a few drops of nitric acid have been added and filtered. The total phosphoric acid is then obtained by precipitation with ammonium molybdate in the usual way. =344. Analysis of the Insoluble Residue.=—The insoluble residue left after digestion with hydrochloric acid is not without interest from an agricultural and analytical point of view. While it is true that the plant food, therein contained, is not immediately available, yet it must not be forgotten that the method of the chemist may not fix a limit to nature’s method of collecting nutriment for plants. In however refractory a state they may exist, it is possible that all nutritive elements may eventually become available for assimilation. For the completion of an estimate of the total nutritive power of a soil, therefore a further examination of the insoluble residue should be made. The methods of securing this are essentially those of making a bulk analysis of the soil. The principle of the method depends on the reduction of the sample to an impalpable powder and the subsequent decomposition of the insoluble portions by treatment with hydrofluoric and sulfuric acids or by fusion with the alkalies. =345. Method of Wolff for Treating Residue Insoluble in Hot Acid.=—The well-washed residue is dried with the filter, then separated therefrom, the filter burned and the ash weighed with the whole of the residue. About eight grams of the residue are ignited and serve for the estimation of the insoluble mineral matter. Another portion of ten grams of the dried, but not ignited, residue is boiled with a concentrated solution of sodium carbonate with the addition of caustic soda, and the quantity of dissolved silicic acid estimated. A third portion of about fifteen grams is treated with about five times its weight of pure concentrated sulfuric acid, and is evaporated until the mass has taken the form of a dry powder. After moistening with concentrated hydrochloric acid the mass is boiled with water, filtered, and the filtrate examined according to the ordinary methods for silicic acid, alumina, iron, lime, magnesia, and alkalies. The residue after treatment with concentrated sulfuric acid is dried, but not ignited, and boiled with a concentrated solution of sodium carbonate with the addition of a little caustic soda, filtered, heated, and the silicic acid separated from the solution. After thorough washing, the residue, after ignition, is weighed and represents the material insoluble in concentrated hydrochloric and sulfuric acids. The silicic acid found as before, together with the small quantity dissolved in the hydrochloric acid extract, gives, in connection with the alumina contained in the sulfuric acid extract, approximately the quantity of pure water-free clay contained in the soil. In six samples of soils of very different compositions which were examined by the above process, it was found that the clay had the following mean composition: Silicic acid, 55.1 to 61.5 per cent, alumina, 38.6 to 44.9 per cent; as a mean 58.05 per cent silicic acid and 41.95 per cent alumina. Finally, four or five grams of the residue, after treatment with sulfuric acid and sodium carbonate, are rubbed up in an agate mortar and completely separated into silt by water. The silt mass is dried, lightly ignited, and three grams of it spread in a flat platinum dish moistened with sulfuric acid, and subjected to the action of hydrofluoric acid in a lead oven at 60°, until a complete decomposition of the material is accomplished. In the solution all the different bases can be determined. =346. Method of the Belgian Chemists.=—The method employed by Petermann[222] at the Gembloux Station in the examination of the part of the soil insoluble in hydrochloric acid consists in washing the insoluble portion by decantation with distilled water until all acid reaction is removed. Place the contents of the flask and of the filter in a porcelain dish and dry. After a careful mixing of the mass take out about fifty grams and wash upon the filter until all reaction for chlorin has disappeared, dry, detach the mass from the filter, and incinerate. Place in a platinum crucible two grams of the ground and ignited residue and mix it, using a platinum stirring rod, with twelve grams of ammonium fluorid; heat slightly over a bunsen burner in a muffle with a good draught and regulate the flame in such a way that the operation shall continue for about one hour. After complete decomposition add about two cubic centimeters of sulfuric acid in such a way as to moisten completely the residue, drive off the sulfuric acid carefully at a low red heat and take up the residue with water slightly acidulated with hydrochloric acid and wash the whole into a flask of 500 cubic centimeters capacity. Oxidize by heating for an hour with nitric acid, make up to the mark and filter. The percentages of potash, soda, lime, magnesia, and the silicates are determined exactly as in the hydrochloric acid extract. =347. Bulk Analysis.=—It is frequently desirable to determine the total composition of a soil sample as well as the nature of that part of it soluble in any of the solvents usually employed. The latest methods for this purpose have been well studied by Packard[223] who finds that the variations which occur between duplicates are probably due to the small quantities of material taken for analysis, it being difficult to obtain average samples of a material which is not very finely powdered when small quantities are taken. Moreover, as it is likely to become of importance to know whether the proportions of lime and magnesia vary by as much as one-tenth per cent, and such small variations are within the limits of error of an analysis, and as the total proportion of lime and magnesia in highly siliceous soils, probably does not exceed one-tenth per cent, it is deemed best to take a large quantity of soil for the bulk analysis in each case. The amount adopted for the highly siliceous soils containing much quartz is ten grams. This quantity, taken after quartering down the entire sample, is ground to an impalpable powder and used for the determination of the lime, magnesia, and alkalies, the silica, iron oxid, alumina, and loss on ignition, being determined in one gram samples. The ten grams are decomposed by hydrofluoric and sulfuric acids in a large platinum dish, the solution evaporated, at first on the water-bath until all water is removed and then at a higher temperature until all the free sulfuric acid is driven off, when the residue is heated in a muffle at a low red heat for several hours. At this temperature the sulfuric acid combined with the iron oxid and alumina is driven off, leaving the remaining sulfates unchanged and the iron oxid and alumina are in the form of a powder of no great volume which is easily and quickly washed. This operation is usually successful at first but in some cases the decomposition is not complete as is shown by the appearance of a precipitate on adding ammonia to the filtrate from the aluminum and iron oxids. In such cases the precipitate is dissolved in hydrochloric acid, reprecipitated by ammonia and removed by filtration. In the filtrate from the thoroughly washed aluminum and iron oxids, lime is precipitated as oxalate and separated by filtration; the filtrate is evaporated to dryness and the ammonia salts driven off by heat; the magnesia in the unfiltered watery extract of this residue is precipitated by baryta water, which also removes the sulfuric acid with which the bases had been combined. In the filtrate from this precipitate baryta is precipitated by ammonium carbonate and removed by filtration, leaving the alkalies to be determined in the usual way after conversion into chlorids. The mixed precipitate of magnesia and barium sulfate is treated with hydrochloric acid, filtered, the baryta present removed as sulfate, and the magnesia precipitated in the filtrate from the latter as phosphate. The advantages of this method are that the large quantity of material employed gives some assurance that an average sample has been operated on, and all the bases present in small proportions are estimated in the same sample. The objection to it is the time consumed both in grinding the samples and in determining all the bases in one solution. As a small quantity of material is generally used for determining the silica, iron oxid, alumina, and loss by ignition, and a larger quantity for the remaining bases, slight differences in the unground samples are unavoidable, especially when the quartz grains are somewhat large, it being practically impossible to take two small samples of such a soil which would have the same number of quartz grains. Consequently tedious grinding of large quantities of the soils for the bulk analysis is necessary. This objection does not apply to the official analysis or assay of soils in which considerable quantities are extracted by acid and the solution analyzed, and silica is not determined. In any case, it may be said, when it becomes an object to know whether a soil contains a total of 0.1 or 0.2 per cent of lime or magnesia, of 0.7 or 0.5 per cent of potash, one analysis even of the large quantity of ten grams would be insufficient to decide the point, and at least the mean of two determinations should be taken. SPECIAL METHODS OF DETERMINATION OF SOIL CONSTITUENTS. =348. Preliminary Considerations.=—In the foregoing paragraphs the general outline of the chemical methods of soil examination have been given. There are often occasions, however, which demand a special study of some particular soil constituent. It has been thought proper, therefore, to add here some of the best approved methods of special determinations which have been approved in this and other countries. In the main, the final determination of any particular element of the soil, and its previous separation from accompanying elements, are based on the general processes already given. The variations in many instances, however, seem to require special mention. =349. Condition of Potash in Soils.=—Potash exists in the soil in very different states. That part of it which is combined with the humus material, or with the hydrated silicates, is easily set free from its combinations and is to be regarded as the more assimilable portion. The potash in the soil is found chiefly in combination with silicates, and particularly with the hydrated aluminum silicates, forming clay. As the particles with which it is combined are found in a state of greater or less fineness, the potash itself is set free under the influences of the agents which are active in the soil, with greater or less rapidity, passing into a form in which it can be utilized by plants. In silicates which are very finely divided, such as clay, the potash becomes active in a relatively short time, while in the débris of rocks in a less advanced state of decomposition it may rest for an indefinite period in an inert state. The estimation of the potash which is assimilable in the clay is quite as important for agricultural purposes as to determine that which may be present in the soil in firmer combination. Treating the sample of soil with water does not furnish any useful information in regard to the potash which it contains. Indeed, the absorbing properties of the soil tend to prevent the elimination of the potash in this way, even when it is found in the soluble state. It is therefore, necessary to employ an acid to set the potash free, but variable results are obtained, according to the employment of acids of greater or less concentration and for longer or shorter periods of contact. =350. Estimation of the Potash Soluble in Concentrated Acids.=—In the method of the French agricultural chemists[224] twenty grams of the earth are placed in a dish with a flat bottom, eleven centimeters in diameter, and rubbed up with twenty to thirty cubic centimeters of water. There is added carefully, and in small quantities, some nitric acid of 36° Baumé until all effervescence has ceased, the mass meanwhile being thoroughly stirred. When the carbonates have been decomposed, which can be told by the cessation of the effervescence, twenty cubic centimeters more of the same acid are added. The dish is heated on the sand-bath for five hours, regulating the heating in such a way that there still remains some acid at the end of the operation and the mass is not thoroughly dry. The acid mass is then taken up with hot water, filtered, and washed with hot water until the amount of filtrate is about 300 cubic centimeters. The filtrate should be received in a flask of about one liter capacity. The filtrate will contain the dissolved potash, soda, magnesia, lime, iron and aluminum oxids, and traces of sulfuric and phosphoric acids. For the elimination of the other substances, with the exception of potash, soda and magnesia, a few drops of barium nitrate are added, afterwards sufficient ammonia to render the solution alkaline, and finally an excess of ammonium carbonate in powder added in small portions. These materials are added successively and the whole is left to stand for twenty-four hours. By this operation the sulfuric acid is separated in the form of barium sulfate; the iron and aluminum oxids are precipitated, carrying down with them the phosphoric acid, and the lime is thrown down in the form of carbonate. The mass is now filtered and washed several times with hot water. The filtrate contains in addition to potash, soda, magnesia, and the ammoniacal salts which have been introduced. The ammonium salts are destroyed by adding aqua regia and evaporating the liquid to a very small volume, as described in the method for the estimation of magnesia. The mass is now evaporated in a porcelain dish with a flat bottom, of about seven centimeters diameter, and an excess of perchloric acid added. The evaporation is carried to dryness on a sand-bath, and the heating prolonged until the last white fumes of perchloric acid are disengaged. The mass is now left to cool. There are then added five cubic centimeters of alcohol, of 90° strength. The mass is triturated by a stirring rod, the extremity of which is flattened, in such a manner as to reduce it all to an impalpable powder. It is then left to settle and the supernatant liquid is decanted upon a small filter. The treatment with alcohol of the kind, quantity, and strength described, is continued four or five times. Afterwards, as there may still remain a trace of the sodium and magnesium perchlorates in the interior of the crystals of potassium perchlorate, there are added to the capsule in which all of the alkaline residue has been collected, two or three cubic centimeters of water, and it is evaporated again to dryness and taken up twice with small quantities of alcohol. There are thus removed the traces of sodium and magnesium perchlorates. By means of a jet of boiling water the stirring rod and the filter, which contains the small quantities of potassium perchlorate, are washed, and the liquid passing through is received in the capsule which contains the larger part of the salt. It is then evaporated to dryness and weighed. When there is very little magnesia present, as is generally the case, the estimation of the potash is made without any difficulty by the process just mentioned, but when the proportion of magnesia is high it is found useful to separate it before the transformation into perchlorates. The magnesia is separated by carbonating the residue as indicated in the method for the estimation of magnesia, by treatment with oxalic acid and ignition. By extracting the carbonates formed with very small quantities of water, and filtering, the alkalies are obtained free from magnesia. It is advisable to test the purity of the potassium perchlorate formed which sometimes contains a little silica. For this purpose it is dissolved in boiling water, and any residue which remains is weighed, and that weight deducted from the total weight of perchlorate. By multiplying the weight of potassium perchlorate found by the coefficient 0.339, the quantity of potash contained in the twenty grams of earth submitted to analysis is obtained. _Estimation of the Potash Soluble in Cold, Dilute Acids._—(Method of Schloesing.) Introduce 100 grams of the soil into a one or one and a half liter flask with 600 to 800 cubic centimeters of water. A little nitric acid, of 30° Baumé, is added until the carbonate is decomposed and a slight acid reaction is obtained. Afterwards five cubic centimeters of the same acid are added and it is left to digest for six hours, shaking every fifteen minutes. Instead of taking the whole of the wash-water for the examination, it is better to extract only a portion of it and so dispense with washing. This process is conducted in the following manner: The weight P of the full flask having been determined, as much as possible of the solution, is decanted by means of a very small siphon, of which the flow is moderated by fixing a rubber tube with a pinch-cock to its lower extremity. After the decantation is complete, the flask is again weighed, giving the weight of P′; the weight of liquid taken, therefore, is equal to P − P′. To determine the total weight of the liquid, throw upon a filter the earthy residue insoluble in the acid, and after washing and drying it determine its weight _r_. The weight of the empty dry flask _p_ is also determined. The total weight of the soil will be, therefore, P − _r_ − _p_. The part of the liquid which was extracted from the flask, and upon which the analytical operation is to be conducted is represented by the fraction (P − P′)/(P − _r_ − _p_). This method avoids washing and evaporation which would be of very long duration. It rests upon the supposition that the solid matter from which the liquor is separated has no affinity for the dissolved substances, and that the total of these substances has passed into the liquor, and that the solution is homogeneous. In the liquor first decanted as described before, the potash is estimated. This liquor contains in addition to potash, soda, lime, magnesia, iron and aluminum oxids, as well as phosphoric, sulfuric, and hydrochloric acids. There is first added to it a little barium chlorid to precipitate the sulfuric acid. It is then heated to about 40° in a glass flask and some ammonium carbonate added in a solution containing an excess of ammonium hydroxid. By this process the lime and baryta are precipitated in the form of carbonates; the alumina and iron as oxids, and the phosphoric acid in combination with the last two bases. The magnesium carbonate is not precipitated because it is soluble in the ammonium carbonate with which it forms a double salt. The employment of a gentle heat favors the formation of the precipitate of calcium carbonate in a granular form which lends itself easily to filtration. The contents of the flask are now thrown upon a filter and the insoluble residue washed. The filtrate contains the potash, soda, magnesia, ammonia, and nitric and hydrochloric acids. It is concentrated as rapidly as possible by heating in a flask, and afterwards the ammoniacal salts are destroyed by weak aqua regia and the whole is then transferred to a porcelain dish and evaporated to dryness. There is thus obtained a mixture of potassium, sodium, and magnesium nitrates, from which the potash is separated by means of perchloric acid in the manner already described. _Estimation of the Total Potash._—Beside the potash which can be dissolved by the boiling concentrated acids the soil contains potash combined with silicates, which becomes useful for plant life with extreme slowness. It is often of great interest to estimate the total potash contained in a soil, that is to say, the reserve for the future. In this case it is necessary to free entirely this base from its combinations by means of hydrofluoric acid. The operation is conducted upon two grams of earth previously ignited and reduced to an impalpable powder. The decomposition is conducted in a platinum capsule by sprinkling the sample with a few cubic centimeters of hydrofluoric acid, or solution of ammonium fluorid, and adding a few drops of sulfuric acid. It is then evaporated to dryness and dissolved in boiling hydrochloric acid. The part which remains insoluble is treated a second time by hydrofluoric and sulfuric and afterwards by hydrochloric acid. All of the potash is thus brought into solution. The estimation of the potash, after having obtained it in a soluble state, is conducted in the manner previously described. _Estimation of the Potash as Platinochlorid._—Instead of estimating the potash as perchlorate it can also be transformed into platinochlorid. This process gives as good results as the preceding one but it is necessary in all cases, to separate the magnesia. After having treated the soil as indicated in the case of the estimation of the potash as perchlorate, the separation of the sulfuric and phosphoric acids, of alumina and iron, of magnesia, and the destruction of the ammoniacal salts in the manner already described, there are finally left the alkalies potash and soda in the form of carbonates. These are transformed into chlorids by adding hydrochloric acid; afterwards they are evaporated to dryness and the mixture of the two chlorids weighed in order to determine what quantity of platinum chlorid it is necessary to add, in order that it be in excess. The quantity of chlorid to be added is calculated so as to be in sufficient quantity to saturate the whole of the chlorids weighed, whether they may be composed wholly of sodium or potassium. In this way there is a certainty of having an excess of platinum. The solution of platinum chlorid used should contain in 100 cubic centimeters seventeen grams of platinum. Each cubic centimeter of this solution will be sufficient for a decigram of the sodium and potassium double chlorids. After the addition of the platinum chlorid the mixture is evaporated in a capsule with a flat bottom, on a water-bath. It is important that the temperature should not exceed 100°. If the temperature should go above this there would be a tendency to form some platinum subchlorids insoluble in alcohol. The evaporation is continued until the contents of the dish are in a pasty condition and form a rather solid mass on cooling. It is necessary to avoid a complete desiccation. After cooling, the residue is taken up by alcohol of 95° strength. It is allowed to digest with alcohol of this strength for some time, after having been thoroughly mixed and shaken therewith in order to obtain a complete precipitation of the platinochlorid. This digestion should take place under a small bell-jar resting upon a piece of ground glass. The evaporation of the alcohol is thus prevented. The mass is then washed by means of alcohol of the same strength and the liquors decanted upon a small filter placed within another filter of identical weight, which serves as a tare for it on the balance. The washing is prolonged until the filtrate becomes colorless. All of the particles in the dish should be brought upon the filter by means of a hair-brush. The filters are now dried at a temperature not exceeding 95° and the platinochlorid received upon the interior filter is weighed. The precipitate may also be washed from the small filter into the capsule in which it was formed by means of a jet of alcohol. The alcohol is evaporated and the precipitate weighed in the capsule. The weighing should be made rapidly on account of the hygroscopicity of the material. The weight obtained multiplied by 0.193 gives the corresponding quantity of potash in the soil. _Purification of the Oxalic Acid._—The commercial oxalic acid used in separating the magnesia, often contains lime, magnesia, and potash. When this reagent is used in a sufficiently large quantity in the estimation of the above substances, it is indispensable to free it entirely from them. This is secured by submitting the oxalic acid to successive recrystallizations which are obtained by dissolving it in warm water, filtering and leaving to cool. The mother waters are thrown away. After two or three successive crystallizations the traces of potash and magnesia have disappeared and the oxalic acid obtained after ignition leaves no trace of residue. The purification may also be secured in the following manner: At a temperature of 60° a saturated solution of oxalic acid is made; the liquid is decanted, carried to the boiling point and filtered. Five per cent of nitric acid are added and it is allowed to cool. The crystals which are deposited are collected upon a funnel in which a plug of cotton has been placed, and are washed with a little cold water. _Purity of the Ammonium Carbonate._—The ammonium carbonate employed should not leave any residue whatever after volatilization. In general, it may be said of all the reagents employed in analyses and especially of those employed in large quantities, that it is indispensable to be sure that they contain no traces of the substances which are to be estimated. The acids, ammonia, etc., should always be examined with this point in view. _Estimation of the Soda._—It is often of interest to estimate the soda in the soil, not that it is an element of any great fertility but rather because it is hurtful when in excess. It is determined in the residue obtained in the estimation of potash and is estimated by difference. The weight of the mixture of sodium and potassium chlorids being known when the potash is determined, the weight of its chlorid is to be deducted from the weight of the two chlorids and thus the direct weight of the sodium chlorid is obtained. A better way is to make a direct estimation. The soda is found entirely dissolved in the alcoholic solution obtained by washing the potash salt as before described, for the separation of the potassium platinochlorid. This alcoholic liquor is evaporated to dryness on a water-bath, in a bohemian flask of about 100 cubic centimeters capacity. The residue obtained consists of sodium platinochlorid and a little platinum chlorid. There is now fitted to the bohemian flask a cork stopper carrying two tubes. The apparatus is placed upon a water-bath and kept at about 100°. Through the tube which reaches to the bottom of the bohemian flask, a current of pure hydrogen is passed. The hydrogen passes off through the second tube. The hydrogen completely reduces the salts of platinum. In order that the decomposition may go on more rapidly a few drops of water are added. When the whole mass in the flask has become black owing to the separation of the platinum, it is shaken, evaporated to dryness and hydrogen passed through a second time. This operation is repeated three or four times, being stopped when the water no longer shows a yellow color. There is then in the flask only a mixture of reduced platinum and sodium chlorid. No trace of sodium chlorid has been lost because the temperature has never exceeded 100°. The sodium chlorid is dissolved by washing with water and filtered. The liquor, which must be absolutely colorless, is evaporated to dryness in a platinum capsule and weighed. There is thus obtained the weight of the sodium chlorid. For verification, the sum of the weight of potassium chlorid calculated from the platinochlorid and the weight of the sodium chlorid should be equal to the initial weight of the mixture of the two chlorids. =351. Potash Methods of the German Experiment Stations.=[225]—_a._ To one volume of air-dried fine earth which is obtained by sifting through a three millimeter sieve, two volumes of twenty-five per cent hydrochloric acid are added, or more if the soil contains much carbonate. The acid is allowed to act with frequent stirring for forty-eight hours at room temperature. _b._ To one volume of the soil, as above prepared, are added two volumes of hydrochloric acid and allowed to stand for three hours with frequent shaking, at the temperature of boiling water. _c._ (Halle method.) One hundred grams of the fine earth are treated with 500 cubic centimeters of forty per cent hydrochloric acid, made up to one liter with water and allowed to stand for forty-eight hours with frequent shaking. After filtering, a large aliquot part of the filtrate is evaporated for the estimation of the potash. The evaporated residue is washed into a half-liter flask in which the sulfuric acid is precipitated with barium hydroxid the flask filled to the mark and an aliquot part of the filtrate in a half-liter flask, treated with ammonium carbonate, filtered and the potash estimated as platinochlorid by the usual method. =352. Method of Raulin for the Estimation of Potash in Soils.=[226]—The process rests upon the very feeble solubility in aqueous solution of potassium phosphomolybdate, while sodium, magnesium, calcium, iron, and aluminum phosphomolybdates are more or less soluble. The process does not require complicated separation and permits of the treatment of a small quantity of soil, since the weight of the phosphomolybdate obtained is equivalent to nineteen times that of the potash. The reagent is prepared by dissolving 100 grams of crystallized ammonium molybdate in as little water as possible and adding six and a half grams of neutral crystallized ammonium phosphate dissolved in a little water. Aqua regia is now added cold and some ammonium phosphomolybdate is precipitated. The mixture is heated, adding a little aqua regia from time to time, until the solution of the precipitate is accomplished. The whole is then evaporated to dryness, the final temperature of evaporation not being carried above 70°. Four hundred cubic centimeters of water are now added and five cubic centimeters of nitric acid, and the contents of the dish heated and filtered. The reagent is then ready for use. The liquid to be used for washing the potassium phosphomolybdate is prepared by dissolving twenty grams of sodium nitrate in one liter of water, two cubic centimeters of pure nitric acid, and a mixture of about twenty cubic centimeters of the phosphomolybdic reagent and one and a half cubic centimeters of a solution of potassium nitrate containing eighty grams per liter, slightly heated in order to saturate the liquid with potassium phosphomolybdate. The solution is shaken, allowed to rest, and the liquid decanted. For the preparation of the solution in which the potash is to be estimated, a sample of soil is carefully weighed of such magnitude as to contain about fifteen milligrams of anhydrous potash. The potash salts are dissolved by the usual processes and are separated from the largest part of the calcium, iron, and aluminum salts, and converted into nitrates. The solution is reduced to a volume of a few cubic centimeters and slightly acidulated with nitric acid. Four cubic centimeters of the phosphomolybdic reagent are added for every ten milligrams of anhydrous potash supposed to be present. The solution is evaporated to dryness at 50° and immediately brought upon very small weighed filters, of which each one is double, by using sixty cubic centimeters of the washing liquor mentioned above. The tared filter is likewise washed with the same liquid at 50° and weighed. The weight multiplied by 0.052 gives the anhydrous potash. This method for a direct precipitation of the potash salts does not have the merits of the perchlorate process and both are inferior in accuracy to the usual platinochlorid procedure. =353. Russian Method for Estimating Potash in Soils.=[227]—Ten grams of the soil are digested with 100 cubic centimeters of ten per cent hydrochloric acid on a steam-bath for twenty-four hours. After adding five cubic centimeters of nitric acid to the filtrate it is evaporated to dryness, taken up with dilute hydrochloric acid, filtered, the filtrate saturated with ammonia, the excess of ammonia driven off, again filtered, and the lime separated by ammonium oxalate. The filtrate is treated with a little barium chlorid for the removal of sulfuric acid and afterwards with ammonium carbonate in excess, and digested for twenty-four hours. After filtering, the solution is evaporated in a platinum dish, the excess of ammonia driven off, the residue taken up with water, filtered, treated with hydrochloric acid, evaporated to dryness, and ignited at low heat. The residue is again dissolved in water, filtered, and the potash precipitated with platinum chlorid and estimated in the usual way. =354. Potash Method of the Italian Stations.=[228]—The potash in the soil should be determined in three forms; _viz._, 1. Assimilable potash. 2. Potash soluble in concentrated acid. 3. Total potash. For determination of the first, 100 grams of earth are put into a retort holding a liter and digested with dilute nitric acid. For the analysis, an aliquot portion of the clear liquid is taken or weighed, and the determination of the potash is made by the common methods. For an alternate method, from twenty to fifty grams of earth are put into a retort of 500 cubic centimeters, moistened with water, and nitric acid is gradually added. After one or two hours there are added from 200 to 300 cubic centimeters of water; the liquid is poured without filtering into a retort and the residue washed by decantation. In the liquid, after the elimination of the other substances with barium chlorid, ammonium carbonate, etc., the potash is determined by the ordinary methods. In the second case, by using warm concentrated acids, a portion of the insoluble silica is decomposed, but this decomposition is always partial and the quantity of the potash extracted depends upon the temperature, upon the concentration, upon the duration of the action, and upon the nature of the acid. The method of moistening twenty to fifty grams of earth with water and adding, thereto, concentrated nitric acid of 1.20 density, in such a manner that the earth shall be completely saturated, may also be employed. Then the temperature is kept at 100° during two hours. In the solution, the potash is determined as usual. In the third case the soil is to be decomposed by hydrofluoric and sulfuric acids, or by fusion with alkaline carbonates, and the total potash determined by one of the standard methods. If it is desired to adopt a general method for the determination of the potash the following points must be carefully considered: 1. The quantity of the earth to be examined. 2. The state of humidity or dryness of the same. 3. The quantity, nature, and concentration of the acid. 4. The quantity of the water. 5. The duration of the treatment. =355. Method of J. Lawrence Smith for Potash.=—This method, designed especially for mineral analysis, has been fully approved by the general experience of analysts. The principle of the method[229] depends upon the decomposition of silicates on ignition with calcium carbonate and ammonium chlorid. The object of this mixture is to bring into contact with the mineral, caustic lime in a nascent state at a red heat, the caustic lime being soluble to some extent in calcium chlorid at a high temperature. Pure calcium carbonate, made by precipitation of marble, should be used. The ammonium chlorid should be prepared by taking crystals of pure, sublimed sal ammoniac, dissolving in water, and filtering, and evaporating the solution until small crystals are deposited, the solution being well-stirred until one-half or two-thirds of the whole has crystallized. The mother-liquor is poured off while still hot, and the crystals dried on an asbestos filter at ordinary room temperature. A special platinum crucible should be used in the Smith method, but the common crucible, especially if very deep, can be employed. The special crucible is of about double the usual length. Smith recommends a crucible ninety-five millimeters in length, diameter at top twenty-two millimeters, at bottom sixteen millimeters, and weighing thirty-five to forty grams. The object of the long crucible is to have the part of the bottom containing the silicate subjected to a high heat, while the top of the crucible is at a much lower temperature, thus preventing the loss of alkalies by volatilization. _Method of Analysis._—The samples of soil or silicate containing the alkalies are well pulverized in an agate mortar, and from one-half to one gram of the finely pulverized material taken for analysis. This is carefully mixed with the same weight of finely powdered sal ammoniac and the mineral and sal ammoniac rubbed well together in a mortar. Eight parts by weight of calcium carbonate are next added in three or four portions, and the whole intimately mixed after each addition. The contents of the mortar are emptied on a piece of glazed paper and then introduced into the crucible, which is tapped gently upon the table until the contents are well settled. It is then fixed in the furnace which is used for heating, and a small bunsen burner is placed beneath the crucible, and the heat applied just about at the top of the mixture and gradually carried toward the lower part until the sal ammoniac is completely decomposed, which requires from four to five minutes. The heat is then applied by means of a blast-lamp and the crucible kept at a bright red heat for from forty to sixty minutes. The crucible is allowed to cool, the contents detached and placed in a platinum or porcelain dish of about 150 cubic centimeters capacity, and sixty to eighty cubic centimeters of distilled water added. The solution of the flux may be hastened by heating the water to the boiling point. The crucible and its cover are also well washed with hot water until all matter adhering to them is dissolved. After the slaking of the mass it is best to continue the digestion with hot water for six or eight hours, although this is not absolutely necessary. The contents of the crucible are filtered and washed well with about 200 cubic centimeters of water. The filtrate contains in solution all the alkalies of the mineral, or soil, together with calcium chlorid and caustic lime. A solution of pure ammonium carbonate containing about one and one-half grams of the pure salt is added to the filtrate. This precipitates the lime as carbonate. The dish containing the material is placed on a water-bath and its contents evaporated to about forty cubic centimeters. Two additional drops of ammonium carbonate are added, and a few drops of caustic ammonia, to precipitate any lime which may be redissolved by the action of the ammonium chlorid solution on the calcium carbonate. Filter on a small filter and wash with as little water as possible and collect the filtrate in a small beaker. The filtrate contains all the alkalies as chlorids, together with a little ammonium chlorid. Add a drop of ammonium carbonate solution to be sure all the lime is precipitated, evaporate on a water-bath in a deep platinum dish, in which the alkalies are to be weighed. The dish should have from thirty to sixty cubic centimeters capacity, and during the evaporation should never be more than two-thirds filled. After the evaporation has been completed the dish is slowly heated and then gently ignited over a gas-flame to drive off any ammonium chlorid which may be present. During this process the platinum dish may be covered with a thin piece of platinum to prevent any possible loss by the spitting of the salt after the ammonium chlorid has been driven off. The heat should be gradually increased until it is brought to a point a little below redness, leaving the cover off. The platinum dish is again covered, and when sufficiently cooled placed on a balance and weighed. If lithium chlorid be present it is necessary to weigh it quickly as the salt being very deliquescent takes up moisture rapidly. The alkalies may now be separated in the usual way. If the sample under examination contains magnesia the residue in the capsule should be dissolved in a little water and sufficient pure lime-water added to render the solution alkaline. It should then be boiled and filtered. The magnesia will, in this way, be completely separated from the alkalies. The solution which has passed through the filter is treated with ammonium carbonate in the manner first described, and the process continued and completed as above mentioned. If it be suspected that the whole of the alkalies have not been obtained by the first fusion, the residue upon the filter can be rubbed up in a mortar with an amount of ammonium chlorid equal to one-half the weight of the mineral, mixed with fresh portions of calcium carbonate and treated exactly as in the first instance. Any trace of alkali remaining from the first fusion is thus recovered in the second one. _Method of Heating the Crucible._—The apparatus used by Smith for igniting the crucible is shown in Fig. 67. It consists of an iron filter-stand HG, a clamp, ED, carrying the muffle NC, attached by the supports AB, and heated by the lamp F. The muffle NC is a chimney of sheet iron, eight to nine centimeters long, ten centimeters high, the width at the bottom being about four centimeters on one side and three centimeters on the other. It is made with the sides straight for about four centimeters and then inclining toward the top so as to leave the opening at the top about one centimeter in width. A piece is cut out of the front of the chimney of the width of the diameter of the hole in the iron support and about four centimeters in length, being semi-circular at the top, fitting over the platinum crucible. Just above this part of the chimney, is riveted a piece of sheet iron in the form of a flattened hook, N, which holds the chimney in place by being slipped over the top of the crucible support; it serves as a protection to the crucible against the cooling effects of the currents of air. FIGURE 67. SMITH’S MUFFLE FOR DECOMPOSITION OF SILICATES. ] =356. International Method for Assimilable and Total Potash.=—In the International Congress of Chemists held in Paris in 1889,[230] the discrimination between the assimilable and total potash was declared to be of prime importance. Unfortunately no method is known by which the potash which is present in the soil in a state suited to the wants of plants can be determined with approximate accuracy. In general, that portion which is given up to weak acids may be assumed to be available. In the treatment of soils with weak acid, as pointed out in the Congress, it is demonstrable that with a 0.05 to 0.1 per cent nitric acid solution, the quantity of potash which goes into solution increases by continued stirring of the mixture with the time of action of the acid up to a certain maximum which is reached in from three to four hours, and after that, it is not changed even when the strength of the acid mixture is increased to two per cent. From this time on, concentrated acids withdraw from the soil which has already been exhausted by the weak acid, a new quantity of potash. The soils which have been exhausted by concentrated acids yield also an additional quantity of potash when they are treated with hydrofluoric acid, or melted with barium or sodium carbonate. Potash, therefore, appears to exist in the soil in various forms. First. In the form of indecomposable silicates which have, agriculturally perhaps, very little interest. Second. In the form of silicates which are more basic than those just mentioned. These silicates are attacked by strong acids and give up probably every year a portion of their potash to vegetation. Third. In a form which is easily soluble in weak acids and consequently directly assimilable by plants. In view of the fact that it would be of interest to chemists and agronomists to establish certain methods of investigation so as to be able to obtain comparative results, it was decided to adopt the original method recommended by Gasparin for the estimation of the potash decomposable by concentrated acids. This method consists in the treatment of the soil with boiling aqua regia until the sand which is not decomposed, is white. _Determination of the Fineness of the Earth which is Used for Analysis._—For the estimation of potash, the soil should be divided as finely as possible, and passed through a sieve of thirty meshes to the centimeter. The decomposition is then completed in two hours, while if a sieve of only ten perforations per centimeter is used, the acid must be allowed to work for twelve hours. The determination of the potash after solution, is accomplished by any of the standard methods. =357. Method of Tatlock as Used by Dyer.=—Attention was called in paragraph =328= to the estimation of the total plant food in the soil by extraction of the sample with citric acid. Dyer first determines the total potash by Tatlock’s method which is as follows: To determine potash ten grams of fine dry soil are treated with ten cubic centimeters of hydrochloric acid and evaporated to dryness on the water-bath, the residue taken up with another ten cubic centimeters of acid, warmed, diluted with water, boiled, filtered, and washed. The filtrate and washings are concentrated and gently incinerated to get rid of organic matter, and the residue redissolved in hydrochloric acid, and evaporated slowly with a considerable quantity of platinum chlorid. If the evaporation be conducted slowly, the potassium platinochlorid settles out well, despite the iron, aluminum, and calcium salts, and is easily washed with some more platinum chlorid solution, followed by alcohol. The application of this modification of the platinum chlorid process to solutions containing comparatively minute quantities of potash amid an overwhelming excess of iron, aluminum, and calcium salts is probably new to many chemists. It works admirably, and obviates the necessity for removing iron, aluminum, calcium, magnesium, etc., with the necessary use of ammonia, and the tedious processes of concentration and final volatilization of the ammonium salts; but, of course, the process cannot be employed if soda also is to be determined. The potash, soluble in hydrochloric acid, having been thus determined, the undissolved siliceous matter is incinerated, weighed, and finely ground in an agate mortar. A weighed portion of it is then, as in the Smith method, mixed with a large bulk of pure calcium carbonate and a little ammonium chlorid and heated, beginning with a low temperature, rising slowly to bright redness. The mass is then boiled with water, washed, incinerated, reground, mixed with some more ammonium chlorid, and again heated, boiled, and washed. The process is repeated and the filtrates from all the treatments concentrated, the calcium being removed as carbonate, and the potash determined in the filtrate, after evaporation and incineration at a low temperature, by means of platinum chlorid. Five hundred cubic centimeters of the citric acid solution of the soil, made as described in paragraph =328=, corresponding to fifty grams of soil, are evaporated to dryness in a platinum dish and ignited at a low temperature. The residue is dissolved in hydrochloric acid filtered and washed, and the filtrate again evaporated to dryness and treated again as just described. The potash is then determined as above. =358. Estimation of Total Alkalies and Alkaline Earths.=—To properly determine the exact amount of these substances in a sample of soil it is necessary first to remove the silica. This is accomplished in the process of Berthelot and André[231] by intimately incorporating with the sample, in a state of very fine powder, four or five times its weight of ammonium fluorid. The mixture, in a platinum dish, is moistened with strong sulfuric acid and allowed to stand for a few hours. It is then gently heated until all fumes of hydrofluosilicic acid have disappeared, but the mass is not raised to a red heat. If there is any doubt about the complete decomposition of the silica the treatment is repeated. At the end of the operation there remain only sulfates without excess of sulfuric acid. The sulfates likely to be present are of potash, soda, lime, magnesia, alumina, and iron. The separation of these bodies is conducted in the ordinary manner. Fusing the soil with potash does not give reliable results but it can be used in certain cases for the rapid estimation of alumina and iron. In this case after the separation of the silica in the ordinary way the iron can be determined as ferric oxid. The iron can also be directly determined by reducing to the ferrous state and titrating with potassium permanganate. _Comparison of Fluorin Method with Common Methods._—To establish the difference in the data obtained by the old and new processes samples of the same earth were treated by Berthelot and André by different methods with the following results: By the By the cold By the By fluorin dilute concentrated incineration method. hydrochloric hydrochloric and acid method. acid method. subsequent treatment with boiling hydrochloric acid method. Per cent. Per cent. Per cent. Per cent. Potash 0.886 0.021 0.149 0.176 Soda 0.211 0.024 0.033 0.042 Magnesia 0.087 0.033 0.033 0.067 Lime 1.160 0.879 1.120 1.060 Alumina 3.950 0.102 1.009 2.631 Ferric oxid 2.150 0.296 1.401 1.678 The impossibility of getting all the alkalies and oxids into solution by even the prolonged action of a boiling acid is clearly set forth in the above table. Boiling sulfuric acid might do a little better but would not give correct results. Lime alone of the elements in the soil can be correctly determined by solution in boiling hydrochloric acid, a circumstance due to the fact that lime is found chiefly as carbonate, sulfate, and phosphate in the soil, and these compounds are easily soluble in hot hydrochloric acid with the exception of the sulfate. Even lime could not be thus determined in soils containing silicates rich in lime. The other mineral elements cannot be determined by the wet method. This is due to the forms in which they occur, being mostly silicates of different composition, with excess of silica. As to the silicates they may be divided into two groups. The first of these are the hydrated silicates, resembling the zeolites, capable of being completely decomposed by boiling acids. The first group of silicates is doubtless of greater importance to vegetable life than the second since it would, doubtless, give up its alkalies with greater ease. This distinction is, however, arbitrary. It is, in fact, impossible to place on one side the soluble and on the other the insoluble silicates. This distinction represents only the unequal degrees in the speed of decomposition of the different silicates contained in the primitive rocks under the influence of atmospheric agents, the soil being nothing more than the products of the decomposition of these rocks with vegetable mold. The second group is insoluble in acids. That part of the silicates least decomposed at any given moment will be attacked more easily by acids, while that portion whose decomposition has been pushed furthest will be more slowly attacked. The action of the acid will grow more feeble as the time of contact is prolonged, and after a time a point is apparently reached where the results are nearly constant. But it is evident that this distinction is purely conventional and bears no necessary or even probable connection with the quantity of alkali really assimilable by plants. Vegetables, moreover, exert on a soil, for the extraction of its alkalies and other matters, chemical reactions peculiar to themselves, altogether distinct from the tardy action of atmospheric agents and still more distinct from the rapid action of mineral acids. It is well known with what energy, it ought to be said with what admirable instinct, plants take from the soil the least traces of phosphorus, of sulfur, of potash, of iron, and other substances necessary to their sustenance. These specific actions of vegetables on the soil merit, in the highest degree, the attention of analysts and agronomists. Their intervention plays a most important part in the restitution to the soil, by means of complementary fertilizers, the mineral elements removed by vegetable growth. =359. Estimation of Lime by the French Method.=—The quantity of lime contained in the soil varies within wide limits. Sometimes this base is entirely absent to such a degree that it is even impossible to discover feeble traces of it. Sometimes it composes almost the whole of the earthy mass. Lime is found in the soil principally in the state of carbonate. It is also found combined with organic matter under the form of humates, with sulfuric acid, etc. It is customary to estimate the lime as a whole, without distinguishing between the different states in which it exists. The quantity of material which is used in the French method[232] varies in proportion to the amount of calcareous matter contained in it. For a soil which contains a large amount of lime, one or two grams would be sufficient for the analysis. For a soil which is poor in calcareous matter ten or even twenty grams must be taken. The quantity of lime dissolved differs according to the strength of the acids employed and length of contact of the acid with the soil. The calcium carbonate, the sulfate, the nitrate, and the humate rapidly pass into solution when treated with acid as above, but this is not the case with calcium silicates which are attacked much more slowly. Sometimes the silicates give only an insignificant increase in the amount of lime, and in this case it is immaterial what process of solution is employed. For simplicity it is best to adopt the method of solution in boiling concentrated nitric acid, prolonging the boiling for a period of five hours. This method of operation is sufficient to bring into solution at one treatment, not only the lime, but also the potash and magnesia. After having heated with acid for the necessary time there are added in the capsule in which the solution took place ten cubic centimeters of nitric acid and fifty cubic centimeters of water. The mixture is heated, collected upon a filter and the residue washed. To the filtrate, the volume of which should be from 400 to 500 cubic centimeters, a sufficient quantity of ammonia is added to render it slightly alkaline. There is formed a precipitate of alumina and of iron oxid containing phosphoric acid and also sometimes a trace of the lime combined with the same acid. In order to keep the whole of the lime in solution it is necessary to add a little acetic acid, about ten cubic centimeters more than is necessary to neutralize the ammonia which has been added in excess. If the liquid is turbid on account of the presence of the iron and aluminum phosphates it is necessary to filter it. There is afterwards added a slight excess of ammonium oxalate in solution, and the whole is left for twenty-four hours in order that the calcium oxalate may deposit. Indeed, the complete precipitation is not always immediate, and especially in the presence of magnesia it takes place with slowness. The calcium oxalate is collected upon a filter and washed with hot water. To determine the quantity of the lime the best procedure consists in transforming the oxalate into carbonate by a careful ignition, and afterwards heating in a Schloesing or Leclerc furnace for four or five minutes. The oxalate for this purpose should be contained in a covered platinum crucible. By this method the calcium carbonate is transformed into calcium oxid, in which form it is weighed rapidly to avoid absorption of moisture. In laboratories which have no means of securing so high a temperature as is mentioned before, the lime may be weighed as sulfate. For this purpose the calcium oxalate is transformed into carbonate by ignition in a platinum crucible. Afterwards it is treated with nitric acid until the carbon dioxid is completely driven off. The platinum crucible is now covered with a funnel which is afterwards washed in order to bring back into the dish the small drops which have been projected in the process of boiling. An excess of sulfuric acid is added and evaporated to dryness on a sand-bath. Afterwards, in a muffle, the temperature is carried to a feeble redness until the vapors of sulfuric acid are all driven off. The lime is weighed in the form of sulfate, and the weight multiplied by 0.412 gives the lime contained in the quantity of earth analyzed. In special researches in which it is desired to avoid attacking the siliceous pebbles of the soil, the concentrated nitric acid is replaced by dilute nitric acid in slight excess, and heated for a few moments only. The calcium carbonate is then dissolved with the other calcareous salts not combined with silica in the rock products. The analysis is continued in other respects as just described. =360. Estimation of the Actual Calcium Carbonate.=—The lime which is found in the state of carbonate plays one of the most important rôles in the chemical phenomena which take place in the soil. It is often of great importance to determine it. The most certain process is to estimate the carbon dioxid which is disengaged from the carbonate under the influence of an acid and to receive this gas in a jar graduated to measure it by volume. The flask recommended by the French Commission for this purpose contains about 300 cubic centimeters. The neck of the flask is connected with a condensing tube of about one centimeter interior diameter, which is cooled by a current of water. According to the presumed richness in calcium carbonate varying quantities of earth are taken for analysis, from as little as half a gram for soils which are rich in carbonate, up to five or even ten grams for soils which are poor in carbonate. The apparatus is connected with a mercury pump for the purpose of exhausting the air as completely as possible therefrom. For this purpose the flask in which the carbonate is disengaged is made in the shape of a tubulated retort. Through the opening into the retort, a narrow tube is introduced and connected with a small funnel by means of a rubber tube supplied with a pinch-cock. When the retort has been connected with the mercury pump a slight vacuum is produced and the pinch-cock is opened and forty cubic centimeters of distilled water allowed to enter. The pinch-cock is closed soon enough to retain a portion of the water in the funnel. The retort is then heated and a vacuum partially produced by means of the pump. When the flask is boiling, the steam drives out the air. A refrigerating jacket is connected with the tube leading from the retort to the pump by means of which the steam is condensed and falls back into the flask. After some minutes of boiling, a vacuum is produced; the lamp is then taken away and a cylinder, graduated at 100 cubic centimeters and filled with mercury, is placed over the lower orifice of the pump, and there is introduced into the apparatus, by the funnel above described, some hydrochloric acid in small quantities, but sufficient only to saturate the whole of the carbonate in the sample of soil taken. Usually three or four cubic centimeters will be sufficient. The acid should be added in such quantities as to prevent the production of any large amount of foam. If frothing should be excessive a little oil can be added to the flask. The whole of the carbon dioxid produced in the reaction is withdrawn by means of the mercury pump and collected in the graduated jar. Towards the end of the operation the flask is heated anew in order to produce an ebullition which is continued for some time. The volume of gas collected is measured after making the proper corrections for pressure and temperature. Afterwards the carbon dioxid which has been produced is absorbed by two or three cubic centimeters of a solution of potash of 42° baumé. This potash is introduced into the graduated jar by means of a pipette bent into the form of a =ᥩ= in the lower portion. If the whole of the gas is not absorbed the volume which remains is read, and this is subtracted from the original volume after having made the proper corrections for pressure and temperature. The difference gives the quantity of carbon dioxid contained in the amount of earth employed. From this the actual weight of the calcium carbonate is computed. This official French method does not appear to possess any advantage in accuracy to the usual absorption method and is far more complicated. =361. Estimation of the Active Calcareous Matter in Soils.=—Like other soil elements, the calcium carbonate exists in different degrees of fineness and availability in the soil. It must be admitted that the fine particles play the most important rôle. The calcium carbonate, which exists in large fragments, presents only a circumscribed surface and remains almost inactive, although it is easily corroded by the rootlets of plants. It is possible to estimate in a rapid way, the quantity of fine carbonate in the soil, considering that in a time relatively short, feeble acids act upon calcareous matter proportionally to the surface which it presents, and that it attacks, therefore, especially the finest particles. By measuring the amount of carbon dioxid set free under the action of dilute acids it is possible to estimate the content of available calcareous matter in the soil. The apparatus of Mondesir is used for this purpose by the French chemists. It is composed of a tubulated flask of about 600 cubic centimeters capacity. The interior tubulature carries a manometer fixed by means of a stopper. This is formed of a rubber tube, terminated by a glass tube, whose extremity is united to a little rubber bag, very flexible, placed in the interior of the flask. _Graduation of the Apparatus._—If the apparatus is new it is necessary to begin by graduating it. The rubber bag is filled with water, the air being carefully excluded, in such a way that the level of the water comes just a little above the bend in the tube. There are placed in the flask 125 cubic centimeters of water and it is shaken for a few seconds. The flask and the manometer are then unstoppered and the level of the water in the manometer is made to equal the level of the water in the flask. With a rubber ring the level of the water in the manometer tube is marked. The manometer is then stoppered. There are then added to the flask two-tenths gram of pure calcium carbonate. The flask is closed and shaken for a minute. There are then added, enclosed in a little piece of filter paper, six-tenths of a gram of pulverized tartaric acid and the flask immediately closed and shaken several times. The manometer tube is then uncorked and moved until the level of the water reaches the point marked before. The difference in level after the height of the water remains constant is then read. The depression in the level observed, corresponds to two-tenths gram of pure calcium carbonate. =362. Estimation of the Available Calcareous Matter in the Soil.=—There is introduced into the flask of the apparatus a quantity of soil varying in amount in accordance with the content of carbonate which it is supposed to contain. There are added 125 cubic centimeters of water and the flask is shaken for a minute. As in the test given before, the level of the water in the manometer is then made to correspond to that of the water in the flask. The level in the manometer is marked as before with a rubber band, and the manometer is then closed. There are then added, contained in a piece of filter paper, two grams of pulverized tartaric acid and the operation is finished as described before. The amount of tartaric acid added, in general, should be three times as much as the amount of calcium carbonate supposed to be contained in the earth. The pressure in the manometer being proportional to the quantity of carbon dioxid disengaged, it is easy to calculate the quantity of calcium carbonate in a state of fine division contained in the soil taken for the test. In order to fill the rubber bag it is necessary to put it in its proper place in the apparatus. The flask is filled with water in order to flatten the rubber bag and expel the air from it. It is then closed with a cork. Afterwards, with the aid of a small funnel and with a copper wire placed in the tube, the lower extremity of which descends just to the elbow, the air in the tube is replaced by water. The operation is finished by uncorking the flask and inclining it or shaking it after a partial vacuum has been established. It is useless to attempt to drive off the last particles of the air. The rubber bag should have a content of about double the volume of the whole of the interior of the manometric tube. In the washing which is necessary between two successive operations, it is well to fill the flask entirely with water in order to expel all the carbon dioxid which it may contain. The same remark may be made of this method of determination as was made of the last one. In the present case, however, the operation is not quite so complicated. When the apparatus is once arranged, it will admit of rapid determinations. =363. Lime Method at the Riga Station.=—Ten grams of the non-ignited sample of the fine earth are digested with 100 cubic centimeters of ten per cent hydrochloric acid, in a 250 cubic centimeter erlenmeyer for twenty-four hours on the steam-bath, with frequent shaking. The filtrate, with washings after the addition of five cubic centimeters strong hydrochloric acid, is evaporated to dryness in a porcelain dish and the residue taken up with dilute hydrochloric acid. After filtering, ammonia is added in excess, the excess removed by evaporation, and the mass is again filtered. In the filtrate, the lime is thrown down with ammonium oxalate, filtered, ignited, and weighed as calcium oxid. The above method cannot give exact results chiefly because more or less lime may be carried down with the phosphoric acid. Also if manganese be present it will be thrown down with the lime. These errors are compensatory, but only by chance could the compensation lead to exactness. It would be better in all cases to remove the iron and alumina in such a way as would avoid loss of time. =364. Estimation of Assimilable Lime.=—In the determination of the total lime in soils or even of that part present as carbonate, it is not to be assumed that the quantity assimilable by plants is known; particles of lime minerals in soils are corroded only superficially by the rootlets of plants and any process which would attack only the superficies of the lime particles would thus more nearly resemble the activity of the solvent forces of plant growth. Oxalic acid is a reagent of this kind, attacking only the surfaces of lime particles. Reverdin and de la Harpe guided by this fact have based a method for determining the amount of lime present in the soil in an available state on the solvent action of oxalic acid.[233] After the total lime content has been determined, twenty grams of the soil sample are covered with 200 cubic centimeters of a solution containing in molecular proportion a known quantity of sodium oxalate and carbonate. The mixture is digested on the water-bath for one hour. By this treatment all lime minerals are converted superficially into oxalate while particles containing magnesia are not affected. After filtering and washing well, the filtrate and wash-waters are acidulated with hydrochloric acid. If any precipitate of organic matter be produced separate it by filtration. Treat the filtrate with a slight excess of sodium acetate by which process the excess of hydrochloric acid is replaced with acetic after which the oxalic acid may be separated by treatment with calcium chlorid and subsequently titrated with potassium permanganate in presence of excess of sulfuric acid. The oxalic acid obtained, deducted from the quantity originally present will give the amount consumed on the surfaces of the lime particles and consequently the amount of lime corresponding thereto which may be considered as available for plant growth. =365. Method of the Halle Station for Lime.=[234]—a. _In Phosphates, Limestones, etc._—Four grams of the prepared substance are heated with fifty cubic centimeters of hydrochloric acid and five cubic centimeters of nitric acid, in a porcelain dish on the water-bath to dryness, and left for a few hours at 105° for the purpose of separating the silicic acid. The dry residue is moistened with hot water and a few drops of hydrochloric acid, and allowed to stand for some time with frequent stirring. The contents of the dish are then washed into a half-liter flask, filled up to the mark and the separated silicic acid removed by filtration. If the silicic acid is not taken into account, the solution can be made directly in a half-liter flask. After filtration, an aliquot part of the filtrate is neutralized in a 500 or 250 cubic centimeter flask with ammonia, again acidified with a few drops of hydrochloric acid and allowed to stand six hours at least, in the cold, with ammonium acetate. For each four grams of the substance fifty cubic centimeters of an ammonium acetate solution are used, made by dissolving in one liter of water 100 grams of ammonium acetate. If phosphoric acid is present in excess, iron and aluminum oxids are precipitated completely as phosphates. If iron and aluminum oxids are in excess, the excess must be precipitated by ammonia. If it is feared that in the subsequent precipitation of the lime by ammonium oxalate there may be still some phosphoric acid in solution, before precipitation with ammonium acetate the proper amount of ferric chlorid is added and the iron is afterwards precipitated with ammonia. It is certain that in the presence of oxalic acid and phosphoric acid the lime is precipitated as oxalate, but should it be feared that traces of calcium phosphate are precipitated with the iron and aluminum phosphates the precipitate of iron and aluminum phosphates may be dissolved in hydrochloric acid, neutralized with ammonia, again acidified and a second time precipitated with ammonium acetate and the filtrate added to that first obtained. For the further estimation the filtrates are united and a quantity corresponding to a given part of the original sample, and being in volume from fifty to one hundred cubic centimeters is made slightly acid with acetic acid and while hot precipitated with dilute ammonium oxalate. The filtrate must contain acetic acid since calcium oxalate is best precipitated from a slightly acetic acid solution. The filtering of the calcium oxalate should not take place until from six to twelve hours after precipitation, and during this time it should stand in a warm place. Filter paper of the best quality should be used for the purpose. The dried precipitate is brought into a platinum crucible together with the filter; the filter is first incinerated over an ordinary bunsen and the calcium oxalate converted into calcium oxid by ignition for fifteen minutes over the blast. It is then cooled in a well-closed desiccator and weighed as oxid. If in the precipitation of the iron and aluminum phosphates sodium acetate be employed instead of ammonium acetate, the precipitation must take place hot and filtration also be accomplished on a hot filter. b. _Estimation of Lime in Soils._—For the estimation of lime in soils there may be used either the acid soil-extract, prepared as under the direction for the estimation of potash, or twenty grams of the soil may be treated with hydrochloric acid and a few drops of nitric acid, and evaporated to dryness in a porcelain dish and the silicic acid separated as described for the estimation of lime in phosphates and limestones. In the case of soils, iron and aluminum oxids can be precipitated directly with ammonia since the small quantity of phosphoric acid usually contained in soils is not sufficient to influence in any way the estimation of the lime. For example suppose there is 0.10 per cent of phosphoric acid contained in a soil. In case the whole of this phosphoric acid is taken down with the lime it would only amount to about 0.10 per cent of calcium oxid precipitated as phosphate. This case, however, is very improbable since it is much more likely that the iron and aluminum phosphates will be precipitated and the whole of the phosphoric acid be carried down with them instead of being precipitated with the lime. The precipitation of the lime and its subsequent treatment are to be conducted as just described. =366. Estimation of the Magnesia.=—Magnesia is a much more rare element in the soil than lime. It is usually necessary to operate upon considerable quantities of earth in order to determine the magnesia with any degree of precision. From ten to twenty grams of the soil are taken. The decomposition is accomplished as in the case of lime. A few drops of barium nitrate are added for the purpose of precipitating any sulfuric acid present. Some ammonia and ammonium carbonate are added to precipitate the iron and aluminum oxids, the lime and the excess of barium introduced, as well as the phosphoric acid. The operation is best conducted on a dilute solution having a volume of from 400 to 500 cubic centimeters. The solution from which the lime has been precipitated, contains with the magnesia, large quantities of ammoniacal salts which it is necessary to destroy. For this purpose the solution is concentrated in a flask until its volume is about ten cubic centimeters. About ten cubic centimeters of nitric acid are added and the whole brought to the boiling point. Afterwards a few drops of hydrochloric acid are added. Continuing the heating, hydrochloric acid is added in small portions and, from time to time, some nitric acid until the bubbles indicating the setting free of gaseous nitrogen, resulting from the action of the nascent chlorin upon the ammonia, have completely ceased to appear. The whole is then evaporated on a sand-bath in a porcelain dish in order to separate the silica. The residue is taken up by water containing a few drops of nitric acid. It is filtered and evaporated to dryness in a covered porcelain dish. Upon the residue four or five grams of oxalic acid, in a state of powder, are placed. A little water is added in such a way that the moist mass covers entirely the matter in the dish. In order to avoid all losses there is placed upon the dish a funnel which serves as a cover. The dish is heated on a sand-bath, but when the film which is formed begins to break there are added from time to time, a little more oxalic acid and water until there is no longer any disengagement of the vapor of nitric acid. Afterwards it is evaporated to dryness and the heat raised to a low redness. The magnesia is found in a free state or mixed with alkalies. It is washed with a small quantity of water and collected upon a very small filter paper. The filter paper is dried, burned, the ignition carried to redness and afterwards cooled and weighed. In order to test the purity of the magnesia it is transformed into sulfate by the addition of a few drops of sulfuric acid. The excess of sulfuric acid is driven off by heating moderately by means of a gas-burner moving it in a circular manner round the bottom of the capsule and lifting the cover from time to time in order to allow the vapors of sulfuric acid to escape. The weight of the magnesium sulfate should correspond to that of the magnesia from which it was formed. Magnesia exists most often in the soil in the state of carbonate or silicate. In this last state it is especially abundant in some soils, such as those which are derived from mica schists, serpentines, etc. In treating earth of this last quality with concentrated, nitric acid there is dissolved also a notable part of the magnesia of the silicates. If, however, it is treated for some minutes only with dilute hydrochloric acid the amount of magnesia present as carbonate alone can be estimated separately. =367. Estimation of Magnesia in Soils.=—_Method of the Halle Station._—For the estimation of magnesia the sample of soil or fertilizer is brought into solution in the same way as is given for the estimation of lime. After the separation of the silicic acid, the iron and alumina are precipitated with sodium acetate. In the case of phosphoric fertilizers, ferric chlorid should first be added in order that the excess of phosphoric acid shall be in all cases certainly combined with the iron. After this the lime is separated as usual with ammonium oxalate. After the precipitation of the lime, the magnesia is precipitated in an ammoniacal solution with sodium phosphate and the ammonium magnesium phosphate estimated exactly as in the case with the estimation of phosphoric acid, as magnesium pyrophosphate. A simpler method for the estimation of magnesia consists in precipitating it as ammonium magnesium phosphate in the presence of a solution of ammonium citrate, the other bases remaining in solution. In this case the operation is carried on in an inverse way as described under the estimation of phosphoric acid, the proper quantity of the acid solution being neutralized with ammonia and after the addition of sodium phosphate, the required quantity of citrate solution added and a further excess of ammonia supplied. =368. Estimation of Manganese.=—The estimation of manganese in the presence of Fe₂O₃, Al₂O₃, CaO, etc., presents peculiar difficulties. In ordinary alluvial clays the quantity of manganese is proportionately small and its estimation may be neglected. In volcanic clays the quantity of manganese, in proportion to the lime and magnesia, is much larger. The method used for estimating manganese is that of Carnot.[235] The hydrochloric acid extract of the soil is evaporated to dryness and heated with potassium bisulfate in order to destroy the organic substance, the neutralized solution of the residue precipitated with twenty cubic centimeters of hydrogen peroxid solution and thirty cubic centimeters of ammonia. The colorless filtrate gives, with nitric acid and bismuth peroxid, no trace of reaction for manganese. The precipitate, washed by decantation, is carried into a carbon dioxid apparatus and treated with oxalic acid and dilute sulfuric acid. From the amount of carbon dioxid obtained, the quantity of manganese is calculated on the supposition that the precipitate corresponds to the formula Mn₆O₁₁. =369. Estimation of the Manganese by the French Method.=—Manganese exists in all plants and its presence in small quantities seems necessary to vegetation. The method of estimation adopted by the French Commission is the one proposed by Leclerc and is applicable even when the base exists in small quantities. Twenty grams of the soil are taken and the organic matter destroyed by incineration. In a flask of 200 cubic centimeters capacity, are placed thirty cubic centimeters of water and, little by little, some hydrochloric acid for the purpose of decomposing the calcium carbonate. When effervescence has ceased ten cubic centimeters of the same acid are added and boiled for half an hour, filtered, washed, and the wash-water and filtrate evaporated to dryness in a porcelain dish. Afterwards there are added twenty cubic centimeters of nitric acid of one and two-tenths density, and ten cubic centimeters of water. The liquor is boiled with constant shaking. Afterwards there are thrown in, in two or three portions, ten grams of lead dioxid. The boiling is stopped just at the moment when all the lead oxid is introduced into the liquor and the mixture is then shaken vigorously. The manganese is transformed by this treatment into a highly oxygenized compound having a deep rose coloration. It is transferred immediately afterwards to a graduated cylinder of 100 cubic centimeters capacity, with the wash-waters the volume is completed to 100 cubic centimeters and it is vigorously stirred with a rod, flattened at its extremity, in order to obtain a complete homogeneity of the liquid. The stirring rod is withdrawn and the liquid left to settle. At the end of some minutes the principal part of the liquid is clear, and it is decanted by means of a pipette graduated at fifty cubic centimeters, and this quantity of the clear liquid is poured into a small glass precipitating jar to which is added immediately, with constant stirring, a solution of mercurous nitrate from a graduated burette. The addition of the nitrate is arrested at the moment when the rose color of the liquor disappears, and the volume of the mercurous nitrate employed is read from the burette. It is now necessary to determine the strength of the mercurous nitrate, that is the quantity necessary to decolorize one milligram of manganese. For this purpose dissolve by means of five cubic centimeters of hydrochloric acid 150 milligrams of manganese dioxid, which is prepared perfectly pure by means of precipitation. When the solution is complete evaporate to dryness, add one cubic centimeter of sulfuric acid and heat on a sand-bath until white fumes of sulfuric acid appear. Redissolve in water and make the volume up to 100 cubic centimeters. Each cubic centimeter of this solution should contain one milligram of manganese. Take five cubic centimeters of this solution, equivalent to five milligrams of manganese, treat in a capsule with twenty cubic centimeters of nitric acid and ten cubic centimeters of water, afterwards add ten grams of lead dioxid, carrying on the operation exactly as described above. Fifty cubic centimeters, taken as before described, are then decolorized by the solution of mercurous nitrate, and thus it is easy to calculate the quantity of manganese which corresponds to one cubic centimeter of the mercurous nitrate employed. By a simple proportion the quantity of manganese contained in the twenty grams of earth to be analyzed is calculated. The mercurous nitrate is prepared by dissolving five grams of crystallized mercurous nitrate in one liter of water; it is allowed to repose for some time and is preserved in a well-stoppered flask. =370. Estimation of Iron.=—Iron, in general, is quite abundant in the soil where it is met with, principally in the state of anhydrous sesquioxid or the hydrated sesquioxid of silicates. Some soils, however, only contain iron in small proportions and it can happen that the introduction of iron as a fertilizing element may be useful. Plants assimilate iron only in small quantities, but it appears to be indispensable to their development and to the proper functional activity of their assimilating faculties. The method of estimation which is recommended is based upon the decoloration of potassium permanganate by iron in the ferrous state. The following description, based on the method proposed by the French Commission, will illustrate the process to be followed. Ten grams of the soil are ignited in a porcelain capsule until all organic matter is destroyed. The ignited mass is then introduced into a flask of 100 cubic centimeters capacity with thirty cubic centimeters of hydrochloric acid and fifteen cubic centimeters of water. It is boiled for about half an hour. The iron oxid is dissolved and is found in solution in the form of ferric chlorid. After filtering and washing, the volume of the filtrate is reduced by evaporation to about twenty-five cubic centimeters. The liquor is afterwards placed in a flask of from 100 to 150 cubic centimeters capacity, which is closed by a stopper carrying a tube furnished with a valve destined to prevent the re-entrance of the air. Ten cubic centimeters of dilute sulfuric acid are added from a mixture containing twenty cubic centimeters of strong acid and eighty cubic centimeters of water. Afterwards the iron is reduced to the ferrous state by introducing into the flask, in quantities of about five decigrams, metallic zinc and waiting after each addition until the portion last added is dissolved before adding another. This addition of zinc is continued until the iron is all reduced. When this point is reached and the last portion of zinc added is dissolved, the contents of the flask are transferred rapidly to a precipitating glass of about one liter capacity, in which there has been placed a little lately boiled but cold water. The flask is washed several times with cold water, previously boiled, to remove from it all traces of oxygen. The volume is made up to 500 cubic centimeters, and afterwards, without any loss of time, by means of a graduated burette and with constant stirring, a solution of potassium permanganate is added which is stopped exactly at the moment when the liquor begins taking on a light rose tint. The quantity of permanganate employed is read from the burette and is proportional to the amount of iron contained in the soil. A blank operation is made for the purpose of detecting traces of iron which the zinc may contain. If, as often happens, the soil contains a large amount of iron it is advisable to use only one gram of it for this operation. The aspect of the earth will indicate in general if it be very ferruginous. _Preparation and Standardization of the Permanganate Liquor._—In one liter of water are dissolved ten grams of crystallized potassium permanganate and the quantity of iron which corresponds to one cubic centimeter of this liquor is determined. It may be well enough to remark that this liquor does not remain constant and it is necessary to titrate it from time to time. For this purpose pure iron is taken. Piano wire may be used, being almost pure iron. One-tenth of a gram of this wire is dissolved in a flask in the manner recommended for treating the soil and with the same quantities of acid and water. When the solution is complete it is transferred to the flask to be estimated. It is made up to one liter and permanganate added, just as in the case before mentioned, until the rose color persists. There is thus determined the quantity of iron which corresponds to each cubic centimeter of the permanganate, and by a simple proportion, the quantity of iron contained in the soil analyzed is determined. The Italian agricultural chemists proceed essentially in the same manner in determining the iron in soils, first igniting the sample and afterwards extracting the iron in the ferric state with boiling hydrochloric acid, reducing with hydrogen, and titrating with potassium permanganate. The following are the reactions which take place: Fe₂O₃ + 6HCl = Fe₂Cl₆ + 3H₂O. Fe₂Cl₆ + 2H = 2FeCl₂ + 2HCl. 10FeCl₂ + K₂Mn₂O₈ + 16HCl = 5Fe₂Cl₆ + 2KCl + 2MnCl₂ + 8H₂O. Sulfuric may take the place of hydrochloric acid in the above reactions. FIGURE 68. APPARATUS BY SACHSSE AND BECKER. ] =371. Method of Sachsse and Becker.=[236]—Ferric oxid (not as silicate) in soils can be estimated by reducing with hydrogen, and measuring the hydrogen which is evolved by the action of the reduced iron on an acid. The sample of soil is weighed in a platinum boat, the boat put into a wide glass tube and heated in a stream of dry hydrogen. While this is going on, water is boiled in the flask _A_ (see Fig. 68) from which the stopper has been removed, to drive out the air. When the reduction of the ferric oxid is complete, the boat is slipped out of the tube into the flask without interrupting the hydrogen evolution. In order to accomplish this without allowing the reduced iron to come in contact with the air the flask is inclined, the end of the glass tube inserted until it is covered with water and the boat is then dropped beneath the water. The flask is closed with a cork provided with a funnel tube, _B_, and a delivery tube _C_; the tap _a_ is opened, and tube _b_ connected with a carbon dioxid apparatus from which the gas is passed into _A_ until all the air is displaced. This point is determined by filling the burette _D_ with potash-lye by aspiration at _C_ and allowing the escaping gas from _C_ to enter the burette as indicated in the figure. Any residual gas in _D_ is removed by aspiration at _C_ and allowing the potash-lye in _e_ to enter in its place. The end of the tube _C_ is now placed under the measuring tube _D_, and the clamp _f_ opened and the tap _a_ closed. The funnel is filled with dilute, boiled sulfuric acid, the cork of _b_ replaced and connected with the carbon dioxid apparatus. The burner under _A_ is lighted and acid let in. By continued boiling, all the hydrogen is driven into _D_, the carbon dioxid being absorbed. The measuring tube is then placed in a tall cylinder of water, the volume of gas read and reduced to 0° and 760 millimeters barometric pressure. To be certain that all carbon dioxid is absorbed, some fresh potash-lye may be introduced into _D_ by carefully opening _d_. The iron is then computed from the volume and weight of the hydrogen by the formula (1) Fe + H₂SO₄ = 2H + FeSO₄. If the substance analyzed contains iron silicates, these may be partly decomposed with formation of ferrous sulfate, according to the reaction (2) 2Fe + Fe₂(SO₄)₃ = 3FeSO₄. This will redissolve a part of the metallic iron and yield ferrous oxid. In this case the contents of the flask are cooled in an atmosphere of carbon dioxid, made up to 500 cubic centimeters, of which 250 cubic centimeters are quickly filtered and titrated with permanganate. In order to properly distribute the iron in harmony with its previously existing states the following computations may be made: Represent the ferrous oxid corresponding to formula (1) by x and that „ „ „ (2) by z and that found by titration with permanganate by a. We have then the equation x + z = a. Since seventy-two parts by weight of ferrous oxid formed by formula (1) are equivalent to two parts by weight of hydrogen, x parts of ferrous oxid would set free x/32 parts of hydrogen; and this corresponds to the hydrogen found in _D_; _viz._, b. If a = ¹⁄₃₆ then by solving the equations: Z = a − 36b and X = 36b. The ferrous oxid arising according to formula (2), however, is derived in such a way that only one-third of it corresponds to metallic iron. Then: X + (⅓)z = (⅓)a + 24b. For computing the total ferric oxid reduced by hydrogen there must, therefore, be added twenty-four parts by weight of hydrogen for one-third of the ferrous oxid found by titration with permanganate, and this quantity of ferrous calculated to ferric oxid. Some silicates, such as the micas, give ferrous oxid with hot dilute sulfuric acid. A correction for this is made by making one or more determinations without previously reducing with hydrogen. The method of procedure above described appears to be capable of giving in an easily attainable manner some valuable indications of the state in which iron exists in a soil. While plants do not use any notable quantity of iron during their growth nevertheless its physiological importance is unquestioned. The chief points of difficulty to be considered are found in the changes which the iron may undergo even while heating in a stream of hydrogen, and the practical difficulties of obtaining carbon dioxid entirely free of air. The latter difficulty may be overcome by making blank experiments with carbon dioxid alone and estimating the volume of residual gas. The total volume of hydrogen obtained is then to be diminished by the ascertained amount. In regard to the second point it is known that both ferrous and ferric oxids when ignited with hydrated silicates partly decompose and form new silicates. Care should therefore be taken not to carry the temperature too high during the process of ignition. =372. Carnot’s Method for Estimating Phosphoric Acid in Soils.=—Carnot[237] proposes the following procedure for the estimation of phosphoric acid in soils. The principle of this method depends upon the isolation of silica by the double precipitation of phosphomolybdate. Ten grams of the sifted soil, dried at 100°, are charred if organic matter be present. The charred mass is next moistened with water and afterwards with nitric acid, until the carbonates are decomposed. Afterwards the mass is digested with ten cubic centimeters of nitric acid for two hours at about 100°, with frequent stirring and the addition of fresh acid, from time to time, to replace that which has been evaporated. After filtering and washing with hot water the filtrate is evaporated to a volume of fifty cubic centimeters and treated with five cubic centimeters of concentrated nitric acid and half a gram of crystals of chromic acid. After covering the dish with a funnel to return condensed vapors its contents are heated to the boiling point for half an hour. At the end of this time five grams of ammonium nitrate are added and afterwards fifty cubic centimeters of molybdate solution and the mixture kept at a temperature of about 100° for an hour. The precipitate obtained is washed twice by decantation with water containing one-fifth of its volume of ammonium molybdate solution. It is then dissolved in thirty cubic centimeters of ammonia diluted with an equal bulk of warm water. The solution and the washings should measure eighty cubic centimeters and the ammonia therein is neutralized with nitric acid, keeping the temperature below 40°. When the yellow precipitate formed ceases to redissolve on stirring, a mixture of three cubic centimeters of pure nitric acid and five cubic centimeters of water is added, together with the same quantity of molybdate solution. The precipitate is brought upon a filter, washed first with water containing one per cent of nitric acid and finally with a little pure water, and dried at 100° and weighed. The weight of the precipitate multiplied by the factor 0.0373 gives the quantity of phosphoric acid. The object of the second precipitation is to relieve the process of the necessity of rendering the silica insoluble, as the presence of silica in the solution as above treated does not interfere with the complete precipitation of the phosphate. This was proved by the author, by the introduction of considerable quantities of sodium silicate and these were found not to interfere with the accuracy of the operation. The results are as accurate as those obtained by the methods of the consulting committee of the agricultural stations. The coefficient employed; _viz._, 0.0373, is not the same as that recommended by the committee; _viz._, 0.043. The committee, however, itself has recognized the inaccuracy of the latter number. The composition of the compound obtained by double precipitation according to Carnot is P₂O₅24MoO₃3(NH₄)₂O + 3H₂O. =373. Method of the Halle Experiment Station.=—The available or easily soluble phosphoric acid in soils is estimated by Maercker and Gerlach, as follows:[238] Sixty grams of the air-dried soil as prepared for analysis, are placed in an erlenmeyer with 300 cubic centimeters of two per cent citric acid solution and digested for twenty-four hours in the cold. It is necessary in this time to shake the flask four or five times and to put the stoppers in loosely in order to allow the escape of any evolved carbon dioxid. Of this mixture 200 cubic centimeters are filtered and evaporated in a 300 cubic centimeter dish to dryness. There remains, in most cases, a sirupy-like mass from which even by strong heating the silica is not completely separated. In order to reach this result the residue is treated with twenty cubic centimeters of concentrated sulfuric and five cubic centimeters of fuming nitric acid and heated over a bunsen. As soon as the appearance of foam denotes the beginning of the reaction the lamp must be removed. With strong foaming and the evolution of red-brown vapors the citric acid is completely oxidized. After the reaction is ended the contents of the dish are heated for about fifteen minutes over a small flame so that a continuous, yet not too violent evolution of sulfuric acid fumes takes place. After the silicic acid and the greater part of the lime have been separated in this way the contents of the dish are diluted with water, stirred with a glass rod, washed into a 200 cubic centimeter flask, cooled, filled up to the mark, and filtered. From the filtrate 100 cubic centimeters, corresponding to twenty grams of the earth, are taken, made slightly alkaline with ammonia, acidified by a few drops of hydrochloric acid, and after cooling treated with fifty cubic centimeters of the citrate solution and twenty-five cubic centimeters of the magnesia mixture. The complete separation of the precipitate requires about forty-eight hours and shaking of the precipitate is not necessary. =374. Estimation of total Phosphoric Acid in Soils.=—In the method used at the Halle Station[239] twenty-five grams of the soil sample are boiled with twenty cubic centimeters of nitric acid and fifty cubic centimeters of concentrated sulfuric acid for half an hour. With very clayey soils only half the quantity of the sample mentioned above is used in order to avoid the too great accumulation of soluble alumina. The oxidation of the organic substances of the soils must be carried on at a moderate heat to avoid foaming. During the boiling, the flask is to be often shaken to prevent the soil constituents from accumulating too firmly at the bottom. The total volume is finally made up to 500 cubic centimeters. For the estimation, 100 cubic centimeters of the solution, corresponding to five (or two and a half) grams of the soil, are taken. In order to nearly completely saturate the acid, the solution is treated with twenty cubic centimeters of twenty-four per cent ammonia, care being taken that the precipitate of iron and alumina which is formed is again completely dissolved. The solution is cooled and treated with fifty cubic centimeters of the citrate solution, and then with twenty cubic centimeters of ammonia of above strength, and precipitated with the magnesia mixture. The filtration of the precipitate should not be made for at least forty-eight hours, during which time the flask should be often shaken to prevent the attachment of ammonium magnesium phosphate to its sides and bottom. A detailed description of the citrate method for estimating phosphoric acid will be found in the chapter devoted to this subject under fertilizers. =375. French Method for Phosphoric Acid.=—Phosphoric acid is found in the soil principally in combination with alumina and iron oxid, with organic matters, or with lime and magnesia. Whatever may be the state in which it is found all the phosphoric acid, with the exception of that which enters into the constitution of insoluble mineral particles, can be brought into solution by acids and determined by some of the approved methods. This method of solution, therefore, is capable of determining very accurately the total proportion of phosphoric acid in the soil, but it is incapable of rendering account to us of the state in which the phosphorus is found and of its aptitude to be utilized by plants. The estimation of soil phosphorus, as recommended by the French Commission, is carried on in the following way:[240] Twenty grams of the earth are submitted to ignition in a muffle heated to the temperature of redness but not higher. This calcination eliminates the organic materials, whose intervention in subsequent reactions might be able to prevent the precipitation of a part of the phosphoric acid. The calcined earth is placed in a capsule of about eleven centimeters diameter and saturated with water. There is then added in small quantities, as long as effervescence is produced, nitric acid of 36° baumé. When the effervescence has ceased, after thorough shaking and the addition of a new quantity of acid, it will be found that the whole of the calcium carbonate in the soil has been decomposed. It is necessary then to proceed to the solution of the phosphoric acid by adding twenty cubic centimeters of nitric acid and heating on the steam-bath for five hours, shaking from time to time, and avoiding complete desiccation. At the end of this time the whole of the phosphoric acid has entered into solution. It is taken up by warm water, filtered, and the insoluble residue washed with small quantities of boiling water. But from the solution obtained, which holds in addition to phosphoric acid, some oxid of iron, alumina, lime, magnesia, etc., it is necessary to separate the silica which has passed into solution. For this purpose the mass is evaporated to dryness on a sand-bath, heating toward the end of the operation with precaution and not allowing the temperature to pass beyond 110°–120°. In these conditions there is obtained a magma which sometimes remains quite sirupy when the earth is very highly impregnated with calcium carbonate, but in which the silica is insoluble. It is indispensable that it be eliminated wholly because it would introduce grave errors into the results, as will be seen later on. If the temperature be carried too high during the desiccation this silica would react upon the earthy salts and alkaline earths forming silicates and it would be found ultimately again in solution. The application of a too high temperature would also render somewhat insoluble in nitric acid the iron and aluminum oxids, and these would retain small quantities of phosphoric acid. The desiccation, therefore, requires to be conducted with great precaution. When it is accomplished there are placed in the capsule five cubic centimeters of nitric acid and five cubic centimeters of water, and the whole heated on the sand-bath until the entire amount of iron oxid is dissolved, that is to say, until there is no ferruginous deposit persisting in the liquid. The solution is then filtered and washed with small quantities of boiling water in such a way that the total volume of the filtrate will not exceed twenty-five to thirty-five cubic centimeters. Afterwards there are added twenty cubic centimeters of ammonium nitromolybdate and the whole is left at rest for twelve hours at the ordinary temperature. At the end of this time the whole of the phosphoric acid is precipitated in the form of ammonium phosphomolybdate. In order to be certain that an excess of nitromolybdate has been used in the precipitation, which is indispensable to the total precipitation of the phosphoric acid, a few cubic centimeters of the filtrate are removed by means of a pipette and are mixed with their own volume of the ammonium nitromolybdate. If, at the end of an hour or two, no precipitate is formed the operation can be regarded as terminated. In order to collect and weigh the ammonium phosphomolybdate some precautions are necessary. Two smooth filters are used, one of which serves as a counter-weight for the other on the balance. One of these filters is placed within the other and the phosphomolybdate is collected upon the inner filter. The part of the phosphomolybdate adhering to the precipitating jar is detached by the aid of a stirring rod, one of the ends of which is covered with a piece of rubber tubing. The washing is accomplished with very small quantities of water containing five per cent of its volume of nitric acid. When all of the precipitate is collected upon the filter and the washing is terminated a few drops of water are thrown upon the upper borders of the filters; this is done to displace the acid liquor which has been used in washing. The filters are then carried to the drying oven where they are dried at a temperature not exceeding 90°. The application of a higher temperature would decompose the ammonium phosphomolybdate and lead to results which would be too low. After the drying is completed the two filters are separated and placed upon the arms of the balance and the increase in weight corresponds to the ammonium phosphomolybdate. This, multiplied by the coefficient 0.043, (see page 404) gives the quantity of phosphoric acid contained in the weight of the soil which has been employed. The ammonium phosphomolybdate is pure if all the silica has been eliminated, but if a part of that has remained in solution it would furnish an ammonium silicomolybdate whose weight would be added to that of the phosphomolybdate. The elimination of the silica, therefore, should be made with the greatest care. Different processes have been proposed in order to determine the forms under which phosphoric acid should be regarded as most assimilable. Deherain has proposed acetic acid as a solvent for this purpose. Other scientists, oxalic or citric acid, and the ammonium oxalate or citrate. The solubility of phosphoric acid in these different reagents gives some information in regard to its state, but the relations which exist between this solubility and the assimilability of the acid have not yet been fixed. _Preparation of the Ammonium Nitromolybdate._—One hundred grams of molybdic acid are dissolved in 400 grams of ammonia with a density of ninety-five. The mixture is filtered, and the filtered liquor is received drop by drop in 1,500 grams of nitric acid of one and two-tenths density, constantly stirring. This mixture is left standing for some days in an unexposed locality, during which time a deposit is formed. The clear part is decanted and used. The above method of the French chemists unfortunately attempts to determine the phosphorus content of the soil by weighing the yellow precipitate and using an empirical factor for the calculation, a factor which is probably too high. Experience has shown that at this point it is far more accurate to continue the process by dissolving the yellow precipitate, and subsequently obtaining the phosphoric acid in combination with ammonia and magnesia, or according to the process of Pemberton the content of phosphoric acid in the yellow precipitate might be determined by titration. In regard to the latter method which will be given in full under fertilizers, it may be said that it has been found quite accurate by several analysts, although it is difficult to see how a precipitate which is so variable in its constitution as to be estimated with little safety by weight may yet be capable of rather exact determination by titration. =376. Petermann’s Method for the Estimation of the Phosphoric Acid Soluble in Alkaline Ammonium Citrate.=[241]—From twenty-five to fifty grams of the sample of soil are triturated with 100 cubic centimeters of alkaline ammonium citrate and placed in a flask of 250 cubic centimeters capacity, and allowed to digest for one hour at a temperature of from 35°–40°. After cooling, make up to the mark, filter, take 200 cubic centimeters of the filtrate, evaporate to dryness on a sand-bath in a platinum dish, heat lightly at first, and afterwards to a higher temperature. Take up the residue of the incineration with water and about two cubic centimeters of nitric acid, heat a few minutes gently, filter into a bohemian flask and precipitate with fifty cubic centimeters of ammonium molybdate solution, and estimate the phosphoric acid in the usual way. =377. Method of Dyer for Total and Assimilable Phosphoric Acid.=—For the determination of phosphoric acid, soluble in citric acid, secured as described in paragraph =328=, 500 cubic centimeters of the filtrate obtained, corresponding to fifty grams of the soil, are evaporated to dryness in a platinum dish, gently ignited, extracted with hydrochloric acid, again evaporated, ignited and extracted, and the phosphoric acid determined as below in the method applied to the hydrochloric acid extract of the soil itself. The total phosphoric acid is determined in each case in ten grains of the dried soil and also in twenty-five grams, the mean of the two results being taken. The numbers obtained in each case are, however, all but identical, the difference in the duplicate percentages being in most cases only a small one in the third place of decimals. The soil is incinerated and digested with hydrochloric acid, and evaporated to dryness, redigested with acid, filtered, and washed. The filtrate and washings are concentrated to a small bulk, and treated, in the cold, with excess of a solution of ammonium molybdate in nitric acid. After standing forty-eight hours, the liquor is decanted through a filter, the precipitate washed several times by decantation, first with dilute acid, then with pure water in very small doses, and finally transferred to the filter and washed free from excess of acid. The ammonium phosphomolybdate is then dissolved in ammonia, evaporated to dryness in a platinum capsule, and dried to constant weight at 100°. The residue contains three and one-half per cent of its weight of phosphoric acid. This is the method of Hehner; and for determining small quantities of phosphoric acid, such as occur in soils or in solutions of iron and steel, is in the opinion of Dyer very much to be preferred to the old-fashioned method of conversion into magnesium ammonium phosphate. The solubility of the yellow precipitate in the small quantity of wash-water used is in most cases negligible. As a matter of fact, the quantity of wash-water used in these analyses was found capable of dissolving only 0.005 gram of precipitate, of which only 0.00017 is phosphoric acid, making an error of 0.0017 per cent on the soil if ten grams be used, or of only 0.0006 if twenty-five grams be used. In the citric acid experiments the solution from fifty grams of soil is used, when the error due to solubility of precipitate shrinks to 0.0003 per cent. The correction for this solubility is, however, made in each case. It may be observed that the method of Hehner is not applicable if the molybdic solution be added to a hot liquid, since, in that case, some molybdic acid is sure to crystallize with the yellow precipitate. Moderate and careful warming to about 35° hastens precipitation, but it is preferable, when speed is not a special object, to precipitate cold, and leave the beaker standing at the laboratory temperature over night, or longer if the quantity to be determined is very minute. =378. Methods of Berthelot and André.=—The phosphorus in the soil may be found under three forms; _viz._, 1. Phosphoric acid in phosphates. 2. Phosphoric acid in ethers which alkalies decompose slowly and oxidizing agents destroy with regeneration of phosphoric acid. 3. Organic compounds or mineral compounds of phosphorus which are resolved by alkaline solutions with formation of phosphoric acid and which are not reduced to this state by the reagents employed in the wet way of decomposition except after a contact of indefinite length and uncertainty. It is, therefore, seen that the employment of oxidizing agents for the valuation of phosphoric acid in soils and vegetables is not a very reliable procedure. The same is true after incineration by which more or less phosphorus may be lost or rendered insoluble in acids. The methods used by Berthelot and André for the estimation of these forms of phosphorus are as follows:[242] _Total Phosphorus._—The sample is at first oxidized by a current of air near a red heat and the vapors are conducted over a column of sodium or potassium carbonate at the same temperature. The combustion is finished in a current of pure oxygen. All phosphorus compounds, even those which are volatile, are by this treatment converted into phosphoric acid. The part of the acid held by the carbonate is to be determined with the non-volatile portions. A less certain method of oxidation consists in mixing the material with potassium nitrate and carefully throwing it little by little into a red hot platinum crucible. _Estimation of the Phosphoric Acid Pre-existing as Phosphates._—The sample is treated with a cold dilute acid incapable of exercising an oxidizing or decomposing effect on the ethers. The dissolved acid is precipitated and weighed in the usual way. The precipitate first obtained should be ignited and the phosphoric acid taken up and reprecipitated. This is necessary to remove any organic matter or silica which the first precipitate may contain. _Estimation of Ethereal Phosphoric Acid._—The sample is boiled for some time with a non-oxidizing acid or with a concentrated solution of potash. The phosphoric acid dissolved represents that which was present as phosphates and as ethers. From this, deduct that portion pre-existing as phosphates and the remainder represents the part derived from the ethereal compounds. _Estimation of Phosphorus in Organic Compounds and Special Minerals._—From the total phosphoric acid deduct that found as phosphates and ethers. The difference represents the quantity combined as noted in the caption. Illustration. A sample of soil contained: Total phosphoric acid 0.292 per cent. ————— Of this, pre-existing as phosphoric acid 0.109 „ As ethereal phosphoric acid 0.074 „ As organic phosphoric acid 0.109 „ ————— Sum 0.292 „ =379. Method Used at the Riga Station.=—In the method pursued at the experimental station at Riga[243] the organic matter in the fine earth is first destroyed by igniting twenty-five grams in a muffle. The ignited residue is placed in a 250 cubic centimeter erlenmeyer and digested with 150 cubic centimeters of ten per cent hydrochloric acid. The digestion is continued for forty-eight hours with frequent shaking. The filtrate is evaporated to dryness in a porcelain dish to separate any dissolved silica. The residue is taken up with dilute hot nitric acid, filtered, and the phosphoric acid precipitated with ammonium molybdate. The final weighing is made as magnesium pyrophosphate, following the usual procedure in respect of precipitation and washing. Experiments show that approximately ninety-five per cent of the phosphoric acid are obtained by one extraction and five per cent by a second, conducted exactly as the first. Thoms draws the following conclusions from a long series of determinations: (1) For the simple purpose of determining the need of a soil for phosphorus fertilizer a single extraction with ten per cent hydrochloric acid is sufficient. The difference between the first and second extraction; _viz._, five to six per cent is too small to be of any value from a practical point of view. (2) A soil which has been ignited until organic matter is destroyed gives up to the hydrochloric acid solvent about fourteen per cent more phosphoric acid than a non-ignited sample would. (3) The mean temperature in the flask during extraction on a steam-bath is 74°. =380. Method of Hilgard.=[244]—The weighed quantity of soil (usually from three to five grams) is ignited in a platinum crucible, care being taken to avoid all loss. The loss of weight after full ignition gives the amount of chemically combined water and volatile and combustible matter. The ignited soil is now removed to a porcelain or glass beaker, treated with four or five times its bulk of strong nitric acid, digested for two days, evaporated to dryness, first over the water-bath and then over the sand-bath, moistened with nitric acid, heated and treated with water. After standing a few hours on the water-bath it is filtered and the filtrate is evaporated to a very small bulk (ten cubic centimeters) and treated with about twice its bulk of the usual ammonium molybdate solution, thus precipitating the phosphoric acid. After standing at least twelve hours, first at a temperature of about 50°, it is filtered and washed with a solution of ammonium nitrate acidified with nitric acid. The washed precipitate is dissolved on the filter with dilute ammonia water. After washing the filter carefully, the ammoniacal solution is treated with magnesia mixture, by which the phosphoric acid is precipitated. After allowing it to stand twenty-four hours it is filtered, washed in the usual way, dried, ignited, and weighed as magnesium pyrophosphate, from which the phosphoric acid is calculated. When a gelatinous residue remains on the filter after dissolving the phosphomolybdate with ammonia it may consist either of silica not rendered fully insoluble in the first evaporation, or, more rarely, of alumina containing phosphate. It should be treated with strong nitric acid, and the filtrate with ammonium molybdate; any precipitate formed is, of course, added to the main quantity before precipitating with magnesia solution. =381. Separation of Phosphoric Acid From Iron and Alumina.=—The following methods are suggested by Wolff[245] for the complete separation of the phosphoric acid from the iron and alumina in soil analysis, where large quantities of these bases are found in solution: 1. After the separation of the greater part of the iron and alumina the phosphoric acid is precipitated from the solution in nitric acid by molybdic acid. The process is carried on as follows: The acid extract is heated in a flask to boiling and the iron oxid completely reduced by the gradual addition of small particles of sodium sulfite. While still warm the free acid is neutralized with soda-lye, and ammonia added until the ferrous hydroxid and the aluminum hydroxid are completely separated. Acetic acid is now added in excess and until about four-fifths of the whole precipitate have passed again into solution. Then, after boiling for a moment, the whole is quickly filtered through a large filter with a cover, and the contents of the filter finally washed slightly. All the phosphoric acid is thus obtained in combination with some alumina and a very little iron. Nearly the whole of the iron and the larger part of the alumina, by this precipitation, are found in the filtrate and therefore cannot disturb the estimation of phosphoric acid in succeeding portions. The filter is now filled with boiling water and a little nitric acid added. The precipitate is dissolved and received in a beaker. The precipitation of the phosphoric acid is then accomplished by ammonium molybdate in the presence of nitric acid. After twenty-four hours all the phosphoric acid is thus precipitated and the precipitate is free from iron. 2. By the method of Schulze[246] the iron is completely, and the alumina, with the exception of a small quantity, separated, and the precipitation of the phosphoric acid is accomplished either by the addition of a small quantity of tartaric acid and afterwards magnesium sulfate, or directly by means of ammonium molybdate. The principle of the separation depends on the fact that when the hydrochloric acid is nearly neutralized with soda or ammonia, and the solution boiled after treatment with ammonium formate, the greater part of the alumina remains in solution. The precipitate is quickly filtered, washed with hot water, dried, taken from the filter and fused in a silver crucible with pure caustic alkali, either soda or potash. On solution and boiling with water, the iron is completely separated from the phosphoric acid, and from the small quantity of the alumina present the precipitation of the phosphoric acid can now be accomplished, either by saturation of the alkaline solution with hydrochloric acid and the direct addition of the magnesia solution after the addition of a little tartaric acid and ammonia, or after the addition of nitric acid by ammonium molybdate. =382. Estimation of Phosphoric Acid in Muck and Peat Soils.=—The amount of phosphoric acid obtained by extraction with hydrochloric or sulfuric acid is markedly less in these soils than that obtained after the incineration of the sample, as pointed out by Schmoeger.[247] This is due to the fact that the phosphoric acid is ordinarily combined in the form of nuclein. Extraction of the soils with ether shows that it is not present in the form of lecithin. The nuclein products, as is well known, are decomposed by heating in presence of a liquid at a high temperature for some time. The heating can either take place in an autoclave or in sealed glass tubes. The method is as follows: The sample of soil is thoroughly rubbed up in a mortar with water, and then hydrochloric acid added until one gram of the water-free peat is suspended in about ten cubic centimeters of twelve per cent hydrochloric acid. The sample is placed in a glass or porcelain vessel in an autoclave and heated to 140°–160° for ten hours. The phosphoric acid is then determined in the extract in the usual way. The percentage of phosphoric acid determined in this way is found to correspond to the amount determined by the incineration of the substance. The total phosphoric acid is determined in peats by the incineration of the sample and the estimation of the phosphoric acid in the ash. The phosphoric acid soluble in hydrochloric acid solution is determined by extracting a sample of the soil with twelve per cent hydrochloric acid in the usual way. The difference between this and the total is calculated as phosphoric acid in organic compounds. Or the total phosphoric acid is determined by treating the soil with twelve per cent hydrochloric acid, in the proportion of one gram of soil to ten cubic centimeters of the acid, and the solution is placed in an autoclave and heated for ten hours to 140°–160°, as above described. The phosphoric acid is then determined by the usual method. The difference between the total phosphoric acid as thus determined and the phosphoric acid soluble in hydrochloric acid is calculated as phosphoric acid in organic compounds. =383. Method of Goss.=—On account of the length of time required to determine the phosphoric acid in soils by the usual methods, Goss[248] has proposed the following modification which in his hands has given satisfactory results: Weigh ten grams of the air-dried soil, which has been sifted through a one millimeter mesh sieve, and transfer to a pear-shaped, straight necked, kjeldahl digestion flask, which has been marked to hold 250 cubic centimeters. Add approximately seven-tenths gram of yellow mercuric oxid and twenty to thirty cubic centimeters of concentrated sulfuric acid, as for the determination of nitrogen. Twenty cubic centimeters of acid are nearly always sufficient, but in the case of unusually finely divided clay soils containing little or no sand it is necessary to use thirty cubic centimeters to prevent caking of contents of flask. In doubtful cases twenty cubic centimeters of acid should first be added and at the end of five or ten minutes, if contents show a tendency to cake, ten cubic centimeters more should be introduced. Thoroughly mix the contents of the flask by shaking, place on a suitable support over a burner, boil for one hour, cool, add about 100 cubic centimeters of water, five cubic centimeters of concentrated hydrochloric acid, and two cubic centimeters of concentrated nitric acid, boil gently for two minutes to oxidize iron, cool, make up to volume, and filter through a dry folded paper until perfectly clear. In order to secure a clear filtrate it will usually be found necessary to pour the first portion of the filtrate back through the paper three or four times. Transfer 100 cubic centimeters of the filtrate to an ordinary flask of about 450 cubic centimeters capacity, add strong ammonia until a permanent precipitate forms, then six or eight cubic centimeters of nitric acid to dissolve the precipitate, and boil until clear. In the case of many soils it is not absolutely necessary to oxidize with hydrochloric and nitric acids, as a clear solution can be secured at this point without further oxidation. In the case of some soils, however, and especially in subsoils, the solution cannot be cleared up even by prolonged boiling with nitric acid, but if the solution have been previously oxidized, a clear solution can be secured without any difficulty whatever. Remove the flask from the lamp and after two minutes add seventy-five cubic centimeters of molybdate solution, place the unstoppered flask in an open water-bath kept at a temperature of 80° for fifteen minutes, shaking vigorously four or five times while in the bath; then remove, let stand ten minutes to allow precipitate to settle, filter through a nine centimeter filter avoiding too strong a pressure at first, wash the flask and precipitate thoroughly with ammonium nitrate solution, place the flask in which the precipitation was made under the funnel, shut off pump and close all valves to filtering jar to form an air-cushion and prevent too rapid filtration, fill paper two-thirds full of hot water, add a few cubic centimeters of strong ammonia, aid solution, if necessary, by stirring precipitate with a small glass rod. As pointed out by Hilgard, aluminum is sometimes carried down with the phosphoric acid upon precipitating with molybdate solution, in which case some of the phosphoric acid will not be dissolved in the treatment with ammonia. This will be indicated, first, by the appearance of a white precipitate upon dissolving the yellow precipitate in ammonia; and, second, by the difficulty experienced afterward in washing. If such a precipitate be present in any appreciable quantity, proceed as follows: After washing out all the ammoniacal solution in the usual manner, place a small beaker under the funnel, close all valves, fill the filter one-third full of hot water, add the same amount of concentrated hydrochloric acid, proceed as if dissolving phosphomolybdate in ammonia, and receive final solution and washings in flask used. As soon as the yellow precipitate is dissolved open the valve to filtering jar but do not turn on the pump; after the solution has all passed through rinse the filter once with a small amount of hot water; after the last portion has passed through remove the flask and place a No. 1 lipped beaker under the funnel and heat the solution in the flask to boiling. If the solutions have not been oxidized, a blue color is sometimes present upon dissolving the yellow precipitate in ammonia. This can be discharged by boiling the ammoniacal solution for a minute or two and shaking at the same time. Again pour the solution through the filter, avoiding use of pump at first, otherwise loss from spattering is likely to ensue, wash out flask and filter with a small amount of hot water, (the total filtrate should not exceed fifty cubic centimeters), add hydrochloric acid to contents of beaker while hot, until yellow color appears, then add a few drops of ammonia until solution clears, cool, add fifty cubic centimeters of filtered magnesia mixture from a burette, a drop at a time with constant stirring, let stand fifteen minutes, add twenty cubic centimeters of strong ammonia specific gravity nine-tenths, let stand over night, filter, wash precipitate with dilute ammonia, dry, ignite intensely over blast-lamp for ten minutes, cool in desiccator and weigh Mg₂P₂O₇ secured. _Time of Digestion._—Experience has shown that very little phosphoric acid is extracted from the sample by digestion with sulfuric acid after the first thirty minutes. _Time Required to Precipitate Phosphomolybdate._— When the yellow precipitate is obtained according to the method of Goss practically the whole of it will be thrown down in five minutes. _Agreement with Standard Methods._—Comparative tests of the Goss method against standard methods have shown that it gives almost identical results with them. The variations were never more than 0.02 to 0.03 per cent. While this method has not been sufficiently tried to receive unconditional recommendation it possesses merits which entitle it to the attention of analysts. =384. Estimation of the Sulfuric Acid.=—Sulfuric acid is generally present in small proportions in soils. Since the plants have need of sulfur it is proper to inquire into the presence of the compound which is its principal source. It is in combination with lime that sulfuric acid exists almost always. In addition to this there is also some sulfur combined with the organic matter of the soil. By digesting a soil for six hours with hot, concentrated nitric acid the sulfates are dissolved, and there is transformed into sulfuric acid an important part of the sulfur which is combined with the humic substances. The quantity of soil to be operated upon should be about fifty grams. After filtering and washing with hot water the filtered liquor is collected, in the French Commission method,[249] in a flask and carried to boiling, and five cubic centimeters of a saturated solution of barium chlorid or sufficient to be in slight excess are added. The boiling is continued for some minutes and the flask is allowed to stand for twenty-four hours. The filtrate is received upon a filter and washed with boiling water. The filter is dried and incinerated, allowed to cool, and as there may have been a slight reduction of the sulfate a few drops of nitric acid are added and a drop of sulfuric acid. It is now evaporated to dryness on a water-bath, heated to redness for a few moments, cooled and weighed. The weight of the barium sulfate obtained multiplied by 0.3433, gives the quantity of sulfuric acid obtained from the fifty grams of soil. If it is desired to estimate only the sulfur which exists in the form of sulfate it is necessary to treat the soil with hydrochloric acid in a very dilute state, heating for a few moments only and afterwards precipitate by barium nitrate. If, on the other hand, it is desired to estimate the total sulfur which is sometimes of great interest, it is necessary to employ the process of Berthelot and André. =385. Method of Berthelot and André.=—Sulfur may exist in the soil in three forms; _viz._, 1. Mineral compounds, consisting generally of sulfates and sometimes of sulfids. 2. Sulfur, existing in ethereal compounds or their analogues, as in urine. 3. Organic compounds containing sulfur. _Estimation of Total Sulfur._—The principle on which this operation, as described by Berthelot and André, rests is that already described for phosphorus; _viz._, oxidation in a current of oxygen and passing the vapors over a column of alkaline carbonate at or near a red heat.[250] The ordinary methods of oxidation in the wet way give generally inexact results. _Estimation of Sulfur Pre-existing as Sulfates._—The sample is treated with cold, dilute hydrochloric acid. The filtrate is treated with barium chlorid, the precipitate collected, dried, ignited, washed with a mixture of sulfuric and hydrofluoric acids to remove silica, and afterwards weighed as barium sulfate. _Estimation of Sulfur as Sulfids._—The sample is distilled with dilute hydrochloric acid, and the hydrogen sulfid produced is made to pass through an acidulated solution of copper sulfate in such a way as to transform the sulfur in the hydrogen sulfid into a sulfid, which is afterwards collected and weighed in the usual way. The use of a titrated solution of iodin is not advisable on account of the organic matter which may be present. _Estimation of Sulfur in Ethereal Compounds._—These compounds can be decomposed by boiling with a solution of potash or concentrated hydrochloric acid. The resulting sulfuric acid is precipitated with barium chlorid. Subtract from the sulfates thus obtained those pre-existing as sulfates; the difference represents the sulfur present in ethers. _Estimation of Sulfur in Other Organic Compounds._—This is estimated indirectly by subtracting from the total sulfur that present as sulfates, sulfids, and ethers. =386. Method of Von Bemmelén.=—As Von Bemmelén[251] observes, the estimation of sulfuric acid in soils presents a number of difficulties. A small part of it can be present as sulfate insoluble in water. In addition to this, there is always some sulfur in the organic bodies present. If the soil is extracted with water then the sulfuric acid can be estimated therein when only a trace of humus substance has gone into solution. On the contrary, if there is much humus substance in solution, and also iron oxid, as is the case when the extraction is made with hydrochloric acid, then both of these must be removed, otherwise the estimation is very inexact. By fusing the residue of the solution with sodium carbonate and a little potassium nitrate the organic substance is destroyed, and after treatment with water the iron oxid is separated. If any sulfur has been dissolved in the organic substance present, this is then oxidized to sulfuric acid. The estimation of the sulfuric acid and of the sulfur, therefore, remains unsatisfactory. In a sample of clay from Java, which was rich in calcium carbonate, but which contained no basic iron sulfate, there was found the following percentages of sulfuric acid: Exhausted in the cold with very weak hydrochloric acid, 0.04 per cent; the residue treated in the cold with concentrated hydrochloric acid, the solution evaporated and fused with sodium carbonate and potassium nitrate, 0.07 per cent; again, the residue treated with aqua regia to oxidize the sulfur, the solution evaporated to dryness, fused with sodium carbonate and potassium nitrate, 0.14 per cent; in all 0.25 percent. A sample of the same soil treated directly with aqua regia, and then evaporated and fused as above, gave two-tenths per cent sulfuric acid. A sample of the same soil ignited in a crucible with sodium carbonate and potassium nitrate gave 0.16 per cent of sulfuric acid. The difference between 0.04 and 0.07 per cent can be attributed to the sulfur in the organic substance which was dissolved by the concentrated hydrochloric acid; the quantity, however, is too small to draw any safe conclusion. Possibly it might have been that the very dilute hydrochloric acid did not dissolve all of the sulfate. The quantity of sulfur combined in the organic substance in the above soil may be derived from the following equation; _viz._, (0.2–0.07)/(80) × 32 = 0.05 per cent of sulfur. The estimation of the sulfur in a sample of soil from Deli was carried on with still greater exactness by three different methods. The quantities of hydrochloric acid, nitric acid, and sodium carbonate employed were measured or weighed, and the minute content of sulfuric acid therein estimated and subtracted from the final results. The methods employed were as follows: (A) Extraction with water and afterwards with very dilute hydrochloric acid. (B) Extraction with cold hydrochloric acid, one part to three of water. (C) Extraction with aqua regia. (D) Ignition with sodium carbonate and potassium nitrate. (F) Ignition in a combustion tube with sodium carbonate in a stream of oxygen. The percentages of sulfuric acid obtained by the different methods were as follows: (A) 0.058 per cent. (B) 0.070 „ „ (C) 0.140 „ „ (D) 0.125 „ „ (F) 0.106 „ „ =387. Method of Wolff.=—In regard to the sulfuric acid Wolff calls attention to the fact that in soils which have been ignited, a larger quantity of this acid is found than in soils containing humus.[252] This, doubtless, arises from the oxidation of the organic sulfur. The following special method for determining the sulfuric acid is therefore proposed: Fifty grams of fresh air-dried soil are placed in a platinum dish with a concentrated solution of pure sodium nitrate. After drying, the heat is raised gradually to redness. In this way the complete ignition of the humus present takes place. After cooling, the mass is diluted with hydrochloric acid, with the addition of a little nitric acid, and boiled. In the solution, the silicic acid is first separated and the sulfuric acid estimated in the usual way with barium sulfate. =388. Method of the Italian Chemists.=—The determination of the sulfuric acid is conducted as follows by the Italian chemists:[253] The soil is completely extracted by diluted hydrochloric acid and the sulfuric acid precipitated in the solution with barium chlorid. If a soil is very rich in calcium sulfate it should first be treated with a warm solution of sodium carbonate to decompose the calcium sulfate, and the sulfuric acid determined in the solution after having added hydrochloric acid. =389. Estimation of the Chlorin.=—The estimation of the chlorin is of great importance in certain cases. When this element is lacking in the soil, which, however, is rare, certain plants appear to suffer from its absence. The quality of the forage plants in particular is influenced by it; but when the chlorids are too abundant, which is a frequent case, they prevent or arrest completely the progress of vegetation. Salty soils are, in general, completely sterile. In the proportion of one pound in a thousand in the earth, sodium chlorid is to be regarded as injurious. It is necessary, therefore, in analysis to take account of two cases; _viz._, those of soils poor in chlorids and those of soils rich in chlorids. For soils poor in chlorids the French method directs that[254] 200 grams of the earth are to be washed on a filter with boiling water. The liquor is evaporated to dryness and gently heated to a temperature inferior to redness in order to destroy the organic matter. The residue is taken up by small quantities of water and to the filtered liquor the volume of which should not exceed forty to fifty cubic centimeters are added ten cubic centimeters of pure nitric acid and a sufficient quantity of silver nitrate to produce a complete precipitation. The precipitate is vigorously shaken and allowed to stand for a few hours in a darkened locality. The precipitate is collected upon a double filter and the silver chlorid, after proper desiccation, is weighed. When the soil is rich in chlorids it is washed as has just been described upon a filter. The wash-waters are made up to one liter and fifty cubic centimeters, equivalent to ten grams of the soil, are taken for analysis. This quantity is treated exactly as described above. =390. Wolff’s Method of Estimating Chlorin in Soils.=[255]—Three hundred grams of the soil are treated with 900 cubic centimeters of pure water containing a little nitric acid for forty-eight hours with frequent shaking. Four hundred and fifty cubic centimeters are then filtered and the clear liquid evaporated to 200 cubic centimeters. The chlorin is then precipitated with silver nitrate. The quantity obtained, corresponds to that found in 150 grams of the air-dried soil. A second method, Mohr’s, is as follows: Fifty grams of the soil are placed in a platinum dish and moistened with a concentrated solution of potassium nitrate, free from chlorin. The mass is evaporated to dryness and gradually heated to a red heat. After cooling it is moistened with water and washed into a beaker and the solid mass quickly separated. The clear liquid is poured off and the residue again washed with water. The clear liquid obtained is saturated with acetic acid, carefully evaporated to dryness and after solution in water, filtration and the addition of a little nitric acid, the chlorin therein is precipitated by a silver nitrate solution, and the precipitate collected and weighed as usual. =391. Method of Petermann.=[256]—Chlorin in the soil is estimated at the Gembloux station by digesting 1,000 grams of the sample with two liters of distilled water with frequent shaking for thirty-six hours. After allowing to stand for twelve hours with the addition of one gram of powdered magnesium sulfate to facilitate the deposition of suspended matter one liter of liquid is siphoned and evaporated in a platinum dish with the addition of a few drops of a solution of potassium carbonate free from chlorin and nitric acid. The concentrated solution is filtered, washed, and made up to 250 cubic centimeters. Take 100 cubic centimeters of the solution add some nitric acid and precipitate the chlorin with silver nitrate. The rest of the solution is reserved for the estimation of nitrate. =392. Estimation of Silicic Acid.=—_Direct Estimation._—The sample of soil in the method of Berthelot and André[257] is mixed with two or three times its weight of pure sodium carbonate and fused in a silver crucible until complete decomposition has taken place. The residue is dissolved in water and dilute hydrochloric acid. The silicates are decomposed by this treatment and the solution is evaporated to dryness on the water-bath, and when dry slightly heated. The silicic acid (silica) is by this treatment rendered insoluble. It is collected on a filter, washed, ignited, and weighed. The resulting compound should be mixed with ammonium fluorid and sulfuric acid, and after the disappearance of the silica the residue should be dried and weighed. The loss in weight represents the true silica. The loss in weight should be corrected by calculating the sulfates of the alkalies back to oxids. This correction can be neglected when the work has been carefully done, and the washing of the original silica has been well performed. _Indirect Estimation._—The total silica may be estimated indirectly by subtracting from the total weight of the sample the sum of the weights of the other constituents resulting from the separate estimation of each of them after decomposing the sample with hydrofluoric acid. =393. Simultaneous Estimation of Different Elements.=—The operations and processes for the estimation of each of the elements have been described, but it is often best to carry on an operation in such a way as to gain time by making a single decomposition upon a quantity of soil of some considerable magnitude, and using the results of the solution for the determination of the different substances. From the operations already described it will be easy to make a combination of methods by which all or nearly all the important constituents in a soil may be determined in a single sample. Of the various methods proposed, that of the commission of the French agricultural chemists may be taken as a type.[258] In the case of the estimation of lime, potash, magnesia, and sulfuric acid, in which the operation is carried on in a soil which is not incinerated, time may be saved by digesting a considerable quantity of the soil with concentrated nitric acid for a period of five hours. It is best to take 100 grams of the soil and increase proportionally the nitric acid. The filtrate, after washing, is made up to one liter and thoroughly shaken. From this amount of liquid, portions are taken corresponding to the weights of soil upon which the operation for the determination of each of the constituents would be conducted. For example, for the estimation of lime in the case of a very calcareous earth, ten cubic centimeters representing one gram of the original sample, in the case of a soil poor in carbonates 100 cubic centimeters representing ten grams, and for the estimation of potash, magnesia, and sulfuric acid 200 cubic centimeters, representing twenty grams of the soil, should be taken. This method avoids frequent weighings of the earth and separate treatments thereof by the acid. On the other hand, in the same portion of the solution, the different elements can be estimated. For example, for the estimation of the potash as has been indicated, in the place of precipitating as a whole the sulfuric acid, lime, etc., and of afterwards separating the magnesia in the sole aim of eliminating these bodies, they can be collected separately and weighed, thus securing at a single operation several determinations. At the end, some barium chlorid is added and if the barium sulfate is then collected and weighed, the estimation of the sulfuric acid is effected. To the filtrate there are afterwards added some ammonia and ammonium carbonate to precipitate, at once, the excess of barium and the iron and aluminum oxids, the lime and the phosphoric acid. This separation being effected the filtrate contains still the magnesia and the alkalies. The first can be separated by carbonation by means of oxalic acid, collected, and weighed. Finally the potash itself can be estimated in the state of perchlorate. It has thus been possible in the same suite of operations to estimate in a given quantity of the liquid, the sulfuric acid, the magnesia, the lime, and the potash. =394. Estimation of Kaolin in Soils.=—True kaolin is a hydrated aluminum silicate, having the formula H₄Al₂Si₂O₉. This substance is, even in concentrated hydrochloric acid, almost completely insoluble. It contains, theoretically, 13.94 per cent of water of combination. The following methods, due to Sachsse and Becker,[259] can be used for its determination. _Estimation of the Water of Combination._—Heat from one to two grams of kaolin, dried at 100°, for half an hour in a covered platinum crucible to a temperature which shows an incipient red heat when the crucible is partly protected from the daylight with the hand. This treatment does not quite give the whole of the water of combination but nearly all of it. A kaolin is changed by this treatment into a substance which is easily soluble in dilute hydrochloric acid. _Estimation of the Kaolin in Impure Kaolins._—Mineral kaolin, or the kaolin obtained by silt analysis, is dried at 100° to constant weight. It is then heated with strong hydrochloric acid until all the matters which will pass into solution have been dissolved. The residual kaolin is then washed thoroughly with water and ignited for half an hour at a low red heat. The residual mass is a second time extracted with hydrochloric acid until silica no longer passes into solution. The soluble silica is then estimated in the usual way and calculated to kaolin. The result will give the pure kaolin in the sample examined. The estimation may also be made as follows: Two samples of the impure kaolin are taken and dried to constant weight at 100°. One is extracted with hydrochloric acid in the manner described above and the amount of silica determined. The second is treated directly by ignition to low redness for half an hour, dissolved in hydrochloric acid and the amount of silica determined. The difference in the two percentages of silica corresponds to the silica equivalent to the pure kaolin. _Statement of Results._—It is convenient to incorporate the data obtained by the above methods with the complete mass analysis of the silicate examined. In the sample given below the analysis was made on a clay silt obtained with a velocity of two-tenths millimeter per second. The mass analysis gave the following data: Loss on ignition 10.04 SiO₂ 51.52 Al₂O₃ 17.93 Fe₂O₃ 7.42 CaO 1.57 MgO 6.27 K₂O 4.1 Na₂O 1.61 The loss on ignition was made up of the combined water and a trace of humus. On gentle ignition only 7.52 per cent of water came off. The examination of the non-ignited and the gently ignited silica by means of dilute hydrochloric acid, gave the following data: Non-ignited. Gently ignited. Difference. Water 10.04 10.04 Insoluble residue 40. 34.54 –5.46 Al₂O₃ 9.04 10. +0.96 Fe₂O₃ 5.96 7.27 +1.31 SiO₂ 25.27 28. +2.73 Alkalies and alkaline earths 9.69 10.15 +0.46 By a comparison of these data with those obtained by the mass analysis, the following representation of the distribution of the various components in the clay is obtained: 23.52 per cent SiO₂ in the form of quartz and undecomposed silicates. 2.73 per cent SiO₂ in the form of kaolin. 25.27 per cent in the form of easily decomposable silicates and of the hydrates of SiO₂. 7.93 per cent Al₂O₃ in the form of undecomposed silicates. 0.96 per cent Al₂O₃ in the form of kaolin. 9.04 per cent Al₂O₃ in the form of easily decomposed silicates and of hydrates. 0.15 per cent Fe₂O₃ in the form of undecomposed silicates. 1.31 per cent Fe₂O₃ in the form of kaolin. 5.96 per cent Fe₂O₃ in the form of easily decomposable silicates and hydrates. 3.40 per cent of alkalies and alkaline earths in the form of undecomposed silicates. 9.69 per cent of alkalies and alkaline earths in the form of easily decomposable silicates. 10.04 per cent of water, including a trace of humus. Collecting these results the following statement is obtained. The clay analyzed contained: 10.04 per cent of water, a trace of humus. 35.15 per cent of undecomposed silicates and quartz. 5.00 per cent of kaolin. 50.27 per cent of easily decomposable silicates, hydrates of SiO₂ and hydroxids. ESTIMATION OF NITROGEN IN SOILS. =395. Introductory Considerations.=—The great economic and biologic value of nitrogen as a plant food renders its estimation in soils of especial importance. It is necessary, first of all, to remember that the nitrogen present in soils may be found in three forms; _viz._, first, in organic compounds, second, as ammonia, and third, as nitric or nitrous acid. Further than this each of these classes of nitrogen may be subdivided. The organic nitrogen may be in a form easily nitrified and rendered available for plant food, or it may be inert and resistant to nitrification, as in humus, or exist in an amid state. The ammoniacal nitrogen may exist in small quantities as gaseous ammonia, or be combined with mineral or organic acids. As nitric or nitrous acid the nitrogen will be found combined with bases, or perhaps in minute quantities as free acid, in passing under the influence of the nitrifying ferment from the organic to the inorganic state. To the latter state it must finally come before it is suited to absorption by plants. In general, far the largest part of soil nitrogen, excluding the atmosphere diffused in the pores of the soil, is found in the organic state and is derived from the débris of animal and vegetable life and from added fertilizers. As ammonia, the nitrogen can only be regarded as in a transition state, arising from the processes of decay, or incomplete nitrification. As nitric acid, it is found as a completed product of nitrification, or as the result of electrical action. The processes of nitrification and the isolation and determination of the nitrifying organisms will be considered in a special chapter of this manual. By reason of the great solubility of the nitrates, and the inability of the soil to retain them, there can never be a great accumulation of nitric acid in the soil save in localities deficient in rain-fall or in specially protected spots, such as caves. The nitric acid, therefore, produced in the soil passes at once into growing vegetation, or is found eventually in the drainage waters. The formation of ammonia in soil containing much vegetable matter is thought by Berthelot and André[260] to be due to the progressive decomposition of amid principles under the influence of dilute acids or alkalies, either in the cold or at an elevated temperature. Soils of the above description, of themselves, contain neither free ammonia nor ammoniacal salts, and the ammonia which is found in the analysis of these soils comes from the reaction above indicated. The ammonia which comes from these soils, in place of what is given off to the surrounding atmosphere, comes from the same class of decompositions, and these decompositions, in this case, are effected by the water itself, and by the alkaline carbonates of the soil. The amid principles which are thus decomposed belong either to the class of amids proper, derived by the displacement of hydrogen in ammonia by acids, or to the class of alkalamids derived from nitrogenous bases, both volatile and fixed. Among these alkalamids some are soluble in water and some insoluble, and the decomposition of these last by acids or by alkalies may furnish bodies which themselves are either soluble or insoluble in water. To determine the nature of the nitrogenous principles in a soil rather rich in humus, Berthelot and André applied the following treatment: A soil containing 19.1 grams of carbon and 1.67 grams of nitrogen per kilogram was first subjected to treatment, at room temperature, with a concentrated solution of potash. By this treatment 17.4 per cent of the nitrogen content was set free under the form of ammonia. One-quarter of this was obtained during the first three days; one-eighth during the next three days. Afterward the action became much more feeble and was continued during forty days longer, and the evolution of the gas was diminished almost proportionately to the time. It appears from the above observations that the amid principles of the soil, decomposable by potash, belong to two distinct groups, which are broken up with very unequal velocities. The soil, treated on the water-bath for three hours at 100° with strong potash, showed the following behavior in respect of its nitrogenous constituents: Nitrogen eliminated in the form of ammonia, sixteen per cent; nitrogen remaining in the part soluble in potash, ten per cent; nitrogen remaining in the part insoluble in potash, seventy-four per cent. _Treatment with Acid._—The nitrogenous compounds of the soil are also decomposed by dilute acids, and often more rapidly than by the alkalies. The method of treatment is substantially the same as that set forth above. The decompositions effected either by alkalies or by acids tend in general to lower the molecular weights of the resulting products. The prolonged action of alkalies at the temperature of boiling water rendered soluble, after twenty-four hours of treatment, 93.6 per cent of the organic nitrogen found in the vegetable mould. By treating the earth successively with alkalies and acids 95.5 per cent of the total nitrogen were decomposed. These experiments show how the insoluble nitrogen in humic compounds can be gradually rendered assimilable. The action of vegetables is not assuredly identical with those which acids and alkalies exercise. However, both present certain degrees of comparison from the point of view of the mechanisms set in play by the earthy carbonates and carbon dioxid, as well as by the acids formed by vegetation. The reactions which take place naturally, while they are not so violent as those produced in the laboratory, make up by their duration what they lack in intensity. For a more detailed study of the nature of the nitrogenous elements in soil the following method of treatment, due to Berthelot and André, is recommended: _Treatment of the Soil with Alkalies._—1. Reaction with cold, dilute solution of potash. Take fifty grams of the sample, dried at 110°, and mix with a large excess of ten per cent potash solution and place under a bell-jar containing standard sulfuric acid. The mixture is left for a long time in order to secure as fully as possible the ammonia set free. Example: Fifty grams of a soil contained 0.0814 gram of nitrogen. Treated as above it gave the following quantities of nitrogen as ammonia: Nitrogen as Ammonia. After 3 days 0.0034 gram. „ 6 „ 0.0054 „ „ 11 „ 0.0065 „ „ 17 „ 0.0078 „ „ 25 „ 0.0093 „ „ 41 „ 0.0107 „ „ 46 „ 0.0141 „ It is seen that the action still continued after forty days. In the space of forty days 17.4 per cent of the total nitrogen contained in the soil had been converted into ammonia by dilute potash. According to the above observations the amid principles transformed into ammonia under the influence of dilute potash, exist in groups which are acted on with very unequal rapidity. 2. Reaction with hot dilute solution of potash. Take 200 grams of the soil sample, mix with one and one-half liters of dilute potash solution containing fifty grams of potash. Place in a flask and heat on boiling water-bath for six hours. The flask is furnished with a stopper and tubes, and a current of pure hydrogen is made to pass through the liquid, having the double object of preventing any oxidizing effect from the air and of carrying away the ammonia which may be formed. The escaping hydrogen and ammonia are passed into a bulb apparatus containing titrated sulfuric acid. The sample of soil employed contained in 200 grams, 0.3256 gram of nitrogen. There was obtained at the end of six hours’ heating, 0.0366 gram of nitrogen. In other words, 11.24 per cent of the total nitrogen in the sample appeared as ammonia. _Examination of Residue._—After the separation of the ammonia as above described, pour the residue in the flask on a filter, wash with hot water, and determine nitrogen in filtrate and in solid matter on the filter by combustion with soda-lime. The filtrate is, of course, first evaporated to dryness after being neutralized with sulfuric acid. The insoluble part contained 0.041 gram of nitrogen, _i. e._, 12.84 per cent of the entire amount. The soluble part contained 0.2411 gram of nitrogen, _i. e._, 74.05 per cent of the whole. _Summary of Data._—In the sample analyzed the following data were obtained: Of the whole. Nitrogen as ammonia 11.24 per cent. „ in insoluble part 12.84 „ „ „ „ soluble part 74.05 „ „ „ not determined 1.87 „ „ —————— Sum 100.00 „ „ The same experiment in which the heating on the water-bath was continued for thirteen hours gave the following data: Of the whole. Nitrogen as ammonia 16.03 per cent. „ in insoluble part 9.98 „ „ „ „ soluble part 74.01 „ „ —————— Sum 100.00 „ „ _Further Treatment of Matter Insoluble in Hot Dilute Potash._—A portion of the insoluble portion from the last experiment was treated for thirteen hours longer under the same conditions with dilute hot potash. The soluble and insoluble portions were determined as already described. Of the nitrogen insoluble after thirteen hours, 64.21 per cent remained insoluble after the second thirteen hours. This fact shows that slow and progressive decomposition of the alkalamids in the soil occurs under the influence of hot dilute potash. _Treatment of Matter Insoluble in Hot Dilute Potash with Hydrochloric Acid._—A part of the material insoluble in hot potash after thirteen hours is mixed with dilute hydrochloric acid, in such proportion as to have one-fifth the weight of pure hydrochloric acid to the dry solid matter. Heat in flask on a boiling water-bath for thirteen hours. Determine the nitrogen in the insoluble residue. _Example_: In the case given it was found that 54.91 per cent of the nitrogen insoluble in dilute hot potash were dissolved by the hot hydrochloric acid. This fact shows that insoluble nitrogen compounds contained in the soil are dissolved by dilute acids even more readily than by dilute alkalies at the temperature of boiling water. Several reactions appear to take place simultaneously when potash is brought into contact with the nitrogenous principles of arable earth. Some of these principles, during the first period of the action become soluble and even form compounds which are not precipitable by acids. When, however, the action of the potash is prolonged, the dissolved bodies lose little by little a part of their nitrogen as ammonia or as soluble alkalamids. They become thus changed either to compounds no longer soluble in the potash, or to those insoluble in the solution when acidified. These compounds, it is true, contain nitrogen, but are poorer in this element and have a higher molecular weight, or, in other words, are condensation products. These last principles are not absolutely stable in the presence of potash, but are decomposed much more slowly than the original principles from which they were derived. In general, it may be said that under the influence of alkalies on the nitrogenous principles of the soil there is a tendency to form two classes of bodies, the one more soluble with a lower molecular weight, the other less soluble with a higher molecular weight. The inverse relation between solubility and condensation is in agreement with what is observed in similar reactions with organic bodies in general. It certainly plays an important rôle in the transformations which an arable soil undergoes, either through the mild influences of the air and natural waters, or the more energetic action of vegetables themselves. The methods of estimating nitric nitrogen will be made the theme of a special study in connection with the chapter on nitrification. There will be considered first, therefore, the methods of determining organic and ammoniacal nitrogen with only such incidental treatment of the methods for nitric nitrogen as the processes applicable to the other forms may contain. =396. Provisional Methods of the Association of Official Agricultural Chemists.=[261]—The nitrogen compounds in the soil are usually placed in three classes. 1. The nitrogen combined with oxygen as nitrates, or nitrites, existing as soluble salts in the soil. 2. The nitrogen combined with hydrogen as ammonia, or organic nitrogen easily convertible into ammonia. The ammonia may exist as salts, or may be occluded by hydrated ferric or aluminum oxids and organic matter in the soil. 3. The inert nitrogen of the soil or the humus nitrogen. _Active Soil Nitrogen._—The material proposed for reducing the nitrates to ammonia, and at the same time to bring ammonia salts and organic nitrogen into a condition for separation by distillation, is sodium amalgam. Liquid sodium amalgam may be readily prepared by placing 100 cubic centimeters of mercury in a flask of half a liter capacity, covering the warmed mercury with melted paraffin, and dropping into the flask at short intervals pieces of metallic sodium, the size of a large pea (taking care that the violence of the reaction does not project the contents from the flask), till 6.75 grams of sodium have combined with the mercury. The amalgam contains one-half per cent of sodium and may be preserved indefinitely under the covering of paraffin. To estimate the active soil nitrogen, weigh fifty grams of air-dried soil and place it in a clean mortar. Take 200 cubic centimeters of ammonia-free distilled water, rub up the soil with a part of the water to a smooth paste, transfer this to a flask of one liter capacity, washing the last traces of the soil into the flask with the rest of the water. Add twenty-five cubic centimeters of the liquid sodium amalgam and shake the flask so as to break the sodium amalgam into small globules distributed through the soil. Insert a stopper with a valve and set aside in a cool place for twenty-four hours. Pour into the flask fifty cubic centimeters of milk of lime, and distill, on a sand-bath, 100 cubic centimeters into a flask containing twenty cubic centimeters of decinormal sulfuric acid, and titrate with decinormal soda solution, using dimethyl-orange as indicator. Estimate the nitrogen of the ammonia found as active soil nitrogen. If the ammonia produced is too small in amount to be readily estimated volumetrically, determine the ammonia by nesslerizing the distillate. _Estimation of Nitrates in the Soil._—When it is desired to estimate separately the nitrates in the soil the following method may be used: Evaporate 100 cubic centimeters of the soil extract to dryness on the water-bath, dissolve the soluble portion, of the residue in 100 cubic centimeters of ammonia-free distilled water, filtering out any insoluble residue, place the solution in a flask and add ten cubic centimeters of liquid sodium amalgam, insert stopper with valve, set it aside to digest in a cool place for twenty-four hours, add fifty cubic centimeters of milk of lime, distill and titrate as above, and estimate the nitrogen as N₂O₅. Nesslerizing may be substituted for titration when the amount of nitrates is small. An approximate estimation of the amount of nitrates will be of value in determining which method of estimation to use. This may be done by evaporating a measured quantity of the soil extract, say five cubic centimeters, on a porcelain crucible cover on a steam-bath or radiator, having first dissolved a minute fragment of pure brucin sulfate in the soil extract. When dry pour over the residue concentrated sulfuric acid, free from nitrates, and observe the color reactions produced. If the nitrate (reckoned as KNO₃) left upon evaporating the quantity of water taken does not exceed the two-thousandth part of a milligram, only a pink color will be developed by adding the sulfuric acid; with the three-thousandth part of a milligram, a pink with faint reddish lines; with the four-thousandth part, a reddish color; with the five-thousandth part, a red color. By increasing or diminishing the amount of soil extract evaporated to secure a color reaction of a certain intensity, an approximate estimate may be made of the amount of nitrates present. Blank experiments to test the acid and the brucin sulfate will be required before confidence can be placed in such estimations. _Total Nitrogen of Soils._—The total nitrogen of soils may be determined by the usual combustion with soda-lime, but this process is often unsatisfactory because of the large amount of material required when the organic matter or humus is small in amount. A modification of the kjeldahl method is more easy to carry out and gives results equally satisfactory. Place twenty grams of soil in a kjeldahl flask, and add twenty cubic centimeters of sulfuric acid (free from ammonia) holding in solution one gram of salicylic acid. If the soil contain much lime or magnesia in the form of carbonate, enough more sulfuric acid must be added to secure a strongly acid condition of the contents of the flask. Add gradually two grams of zinc dust, shaking the contents of the flask to secure intimate mixture. Place the flask in a sand-bath and heat till the acid boils, and maintain the boiling for ten minutes. Add one gram of mercury and continue the boiling for one hour, adding ten cubic centimeters of sulfuric acid if the contents of the flask are likely to become solid. Cool the flask and wash out the soluble materials with 200 cubic centimeters of pure water, leaving the heavy earthy materials. Rinse the residue with 100 cubic centimeters of water, and add this to the first washings. Place this soluble acid extract in a liter digestion flask, add thirty-five cubic centimeters of a solution of potassium sulfid, and shake the flask to secure intimate mixture of the contents. Introduce a few fragments of granulated zinc, pour in seventy-five cubic centimeters of a saturated solution of caustic soda, connect the flask with a condenser and distill 150 cubic centimeters into a flask containing twenty cubic centimeters of acid, using the same acid and alkali for titration used in the kjeldahl method under fertilizers. Enter the nitrogen found in this operation as total soil nitrogen. The difference between the total soil nitrogen and the active soil nitrogen will express the inert nitrogen of the soil. =397. Hilgard’s Method.=[262]—The humus determination will, in the case of virgin soils, usually indicate approximately the store of nitrogen in the soil, which must be gradually made available by nitrification. Ordinarily (outside of the arid regions) the determination of ammonia and nitrates present in the soil is of little interest for general purposes, since these factors will vary with the season and from day to day. Kedzie proposes to estimate the active soil nitrogen (ammonia plus nitrates and nitrites) by treatment of the whole soil with sodium amalgam and distillation with lime. The objection to this process is that the formation of ammonia by the reaction of the alkali and lime upon the humus amids would greatly exaggerate the active nitrogen and lead to a serious overestimate of the soil’s immediate resources. The usual content of nitrogen in black soil-humus is from six to eight per cent in the regions of summer rains. From late determinations it would seem that in the arid regions the usually small amount of humus (often less than two-tenths per cent) is materially compensated by a higher nitrogen percentage. It thus becomes necessary to determine the humus nitrogen directly; and this is easily done by substituting in the grandeau process of humus extraction potash or soda-lye for ammonia water, and determining the nitrogen by the kjeldahl method in the filtrate. The lye used should have the strength of four per cent in the case of potassium hydroxid, three per cent in that of sodium hydroxid. The black humus filtrate is carefully neutralized with sulfuric acid, evaporated to a small bulk in a beaker or evaporating basin, and the reduced liquid finally evaporated to dryness in the kjeldahl flask itself by means of a current of air. The beaker or basin is washed either with some of the alkaline lye, or, after evaporation, with warm concentrated sulfuric acid, which is then used in the nitrogen determination in the usual way. For the determination of nitrates in the soil it is, of course, usually necessary to use large amounts of material, say not less than 100 grams, and, according to circumstances, five or more times that amount. In the evaporated solution the nitric acid is best determined by the reduction method, as ammonia. Usually the soil filtrate is clear and contains no appreciable amount of organic matter that would interfere with the determination; yet in the case of alkaline soils (impregnated with sodium carbonate) a very dark colored solution may be obtained. In that case the soil may advantageously be mixed with a few per cent of powdered gypsum before leaching; or the gypsum may be used in the filtrate to discolor it by the decomposition of sodium carbonate and the precipitation of calcium humate. The evaporated filtrate can then be used for the nitrate determination by either the kjeldahl, griess, or the nessler process, which will, of course, include such portions of the ammoniacal salts as may have been leached out. For the separate determination of these and of the occluded ammonia, when desired, it is probably best to mix the wetted soil intimately with about ten per cent of magnesium oxid and distill into titrated hydrochloric acid. For general purposes, however, this determination is usually of little interest. =398. Müller’s Modified Kjeldahl Method.=—Numerous difficulties, as stated by Müller,[263] have attended the attempts to apply the kjeldahl method for the estimation of nitrogen to samples of soil, and he has modified the method to some extent and made comparisons of the quantity of nitrogen by this modified method and by the soda-lime method. The principal difficulty encountered by him has been in the regular heating of the mixture of fuming sulfuric acid and soil. The particles of soil are deposited at the bottom of the flask and the result is that the bottom layers become overheated, and, being poor conductors of heat, fail to transmit a sufficient quantity of heat to penetrate to the upper layers of the liquid to complete the reaction. In order to avoid this difficulty Müller heats his flask in a small stove formed with a straight vertical cylinder of iron or copper, the upper end of which is covered with a sheet of iron pierced with a hole which allows the neck of the flask to pass through, while the lower end is closed with a piece of sheet iron furnished on its upper surface with a layer of asbestos. This cylinder of metal is surrounded with a second one, concentric with the first through which passes a current of heated gases furnished by an ordinary bunsen. By heating the flask in this stove or furnace an even distribution of the heat is secured to all parts of the mixture, but the little drops of sulfuric acid, which are condensed on the cold part of the neck, sometimes lead to the fracture of the glass as they run down the sides of the flask to the hot portions. To prevent the reflux of this condensed acid, which only needs to be done near the end of the reaction, when it is necessary to heat to a very high temperature, the neck of the flask is bent at the point immediately above its emergence at the upper surface of the furnace, and carried into a flask of about seventy-five cubic centimeters capacity, which will receive the drops of sulfuric acid condensed during the operation. The furnace has the following dimensions; height, twelve centimeters; diameter of interior cylinder, five and one-half centimeters; diameter of exterior cylinder, seven and one-half centimeters. It is supported on a triangle of large iron wire and is heated by an ordinary bunsen, or by a concentric bunsen, according to the temperature which it is necessary to obtain. The proportions which should be observed between the amount of earth employed and the sulfuric acid are about as follows: Of the dry earth, fifteen grams; of the fuming sulfuric acid, thirty cubic centimeters. There should also be added to the mixture about three-tenths of a gram of pure stearic acid, or better, benzoic acid. When the soil to be analyzed does not contain carbonate, the sulfuric acid should be added in two portions. At first add about twenty cubic centimeters of the acid, and after shaking it, the other ten cubic centimeters, running it in from a burette or a pipette in such a manner as to wash thoroughly the neck and sides of the flask. If the earth contain carbonate, however, it is necessary to add the fuming acid in small portions of about five cubic centimeters at a time, waiting each time until the disengagement of the gas caused by the previous addition has ceased. A soil which contains from thirty to forty per cent of calcium carbonate should be carefully treated in a porcelain capsule with a slight excess of sulfuric acid, pure and dilute. The mixture is afterward to be evaporated to dryness upon a sand-bath and the residue heated in a drying oven to 110°. The mass is then pulverized, introduced into the flask, treated with three-tenths of a gram of benzoic acid and thirty cubic centimeters of fuming sulfuric acid, and treated as indicated above. In all cases it is necessary to continue the heating until the contents of the flask are colorless. With soils containing considerable quantities of iron, however, a slight red color will probably be observed which will not interfere with the accuracy of the tests. The heating should at first be gentle and the temperature afterward elevated little by little, and finally the heat should be sufficiently great to distill about one and one-half cubic centimeters of sulfuric acid. The operation lasts from twelve to thirteen hours. As the reaction is terminated the cooled mass is taken up with water absolutely free from ammonia. It is filtered into a flask, and washed upon the filter until the volume of the filtered liquid is about 350 cubic centimeters. Afterward an excess of soda-lye, at 50° baumé is added, then a few pieces of quartz to facilitate boiling. The flask is then connected with a condenser, the liquid distilled and received in a conical flask closed by a cork having two holes, of which one permits the entrance of the end of the condenser, and the other a glass tube which is connected with a small flask containing water, the neck of the receiving flask being inclined toward the condenser to avoid the entrainment of any of the alkaline liquid which may be distilled. The receiving flask rests upon two or three pieces of sheet iron and is heated with an ordinary burner, and ebullition is perfectly regular. From 170 to 180 cubic centimeters of the liquid are distilled in from three and one-half to four hours. The distilled liquid, treated with a few drops of litmus, is titrated by a solution of sulfuric or hydrochloric acid, of which one cubic centimeter corresponds to 0.001 cubic centimeter of nitrogen. =399. Modification of the Kjeldahl Method by Arnold and Wedemeyer.=[264]—For the oxidizing liquid a mixture of three grams of benzoic acid with forty cubic centimeters of H₂SO₄ is employed. After placing in the digestion flask with the nitrogenous body the whole is gently shaken for a few minutes to prevent clotting. The temperature is then raised until acid vapors begin to come off, when one gram of copper sulfate and one gram of mercuric oxid are added; and after ten to fifteen minutes, to avoid foaming, ten to twenty grams of potassium sulfate. The sublimate noticed on the walls of the flask is benzoic acid and does not interfere with the accuracy of the determination. This method has given good results with the alkaline nitrates, the nitrates of barium, mercury, silver, lead, and with strychnia, ammonia, pyridin, azobenzol, dinitrobenzol, and picric acid. =400. Prevention of Bumping During Distillation.=—Daffert has employed the modified kjeldahl method, but found considerable difficulty in using the same owing to the violent bumping of the liquid in the distillation. This was especially the case where the sample contained a large proportion of sand. To overcome this annoyance and danger he devised the following process:[265] Fit into the mouth of a large-mouthed distillation flask a stopper having two perforations. Through one of the perforations pass the usual distillation tube, through the other a similar tube connected with a supply of steam. Bring the contents to a brisk boil, after which a small current of steam is turned on, allowing the same to pass in a small stream throughout the distillation. By this means, not only is all danger from bumping avoided, but the time required for the distillation shortened. By the old method it usually requires from fifteen to twenty minutes, whereas the former requires from six to ten minutes. It is advisable to filter all samples of soils having a large proportion of sand. =401. Determination of Organic Nitrogen by the Soda-Lime Method.=—In the description of the method following, the directions of the French Commission of Agricultural Chemists have been taken as the basis of the analytical process.[266] This method is, in this country, almost superseded by the moist combustion process with sulfuric acid. By reason of its long use, however, and because it is still regarded as the best method by the agricultural chemists of France, Italy, and England, it merits a full description. It is recommended also by Berthelot and André,[267] by the International Congress of Chemists, held in Paris in 1889, by the Italian chemists, and by the official Belgian method,[268] in all cases where nitrates are not present in notable quantities. The nitrogen which is found in soils in the organic state is transformed into ammonia when it is heated with soda-lime. This reaction is the base of the process of analysis which has so long been used for this class of bodies. The analytical process is conducted as follows: A well-cleaned glass combustion tube, closed at one end, is used. The length of the tube is from thirty-five to forty centimeters. It is filled first to a depth of two centimeters with calcium oxalate; afterwards to a depth of five centimeters with soda-lime in small fragments; afterwards with the mixture to be analyzed; _viz._, of ten grams of the sample of soil, or twenty grams if poor in nitrogen and organic matters, with soda-lime reduced to a coarse powder. This mixture should occupy a length of about twenty centimeters in the tube. The soil and soda-lime are mixed in a mortar. Afterwards the mortar is rubbed with small quantities of soda-lime, and this, together with the copper boat which has been used in introducing the mixture, is thoroughly washed with the soda-lime, which is poured into the tube until it is filled to within four centimeters of its open extremity. The open end of the tube is then closed with a wad of asbestos packed sufficiently tight to prevent the carrying off of the soda-lime by the gas which may be generated during the combustion. The combustion should be commenced by heating the tube near the open extremity until it is red and carrying the heat progressively towards the part containing the soil mixed with the soda-lime. An ordinary gas combustion furnace should be used and the heat graduated in such a way that the bubbles of gas pass off regularly and not too rapidly. The gas is conducted into a bulb tube containing a decinormal standard sulfuric acid colored with litmus. The combustion is continued until the whole of the organic material is decomposed, care being taken not to raise the combustion tube above a low redness in order to avoid its softening. At the end, however, the temperature of the combustion tube should be raised to a bright red, and the part containing the calcium oxalate should be heated little by little for the purpose of evolving hydrogen, which is used to drive out the last traces of ammonia. After the combustion is completed, and the last traces of ammonia driven out, the standard acid which has received the evolved ammonia is removed, the tube leading to it washed, the wash-water collected with the rest of the liquid and titrated with a standard solution of lime-water, the strength of which has previously been determined against standard sulfuric acid. =402. Preparation of the Standard Sulfuric Acid.=—The sulfuric acid to be used in making the standard solutions should be previously boiled for half an hour in a platinum dish and allowed to cool in a desiccator. It should contain 61.25 grams of sulfuric acid in one liter. It is recommended that the flask which holds the sulfuric acid should be one which has been used for a long time for holding concentrated sulfuric acid, in order to avoid any action of the alkali in the glass upon the acid after its strength has been determined. The solution before described is of such strength as to have each cubic centimeter equivalent to one milligram of nitrogen. For the estimation of the nitrogen in the soil a tenth normal solution should be used, which is prepared by taking 100 cubic centimeters of the normal solution, described above, and diluting to one liter. _Preparation of the Lime-Water._—From 200 to 300 grams of slaked lime are placed in a closed flask of about five liters capacity. This is filled with water and shaken frequently, and left to deposit the matter in suspension. The water which contains the saline particles which may have been present in the lime is then poured off. Fresh water is then poured on and the flask shaken from time to time. To use this lime-water the clear part of it is decanted into a flask, avoiding, as much as possible, access to the air. The flask is closed with a cork carrying two tubes drawn out and bent at a right angle. One of these serves for pouring off the water and the other serves for the entrance of the air. These two tubes are themselves closed by means of a rubber tube carrying a pinch-cock. The strength of the lime-water is fixed by titration with the decinormal standard sulfuric acid. _Preparation of the Soda-Lime._—Six hundred grams of slaked lime in fine powder are saturated with 300 grams of caustic soda dissolved in 300 cubic centimeters of water. The whole is rubbed into a paste and introduced into a crucible which is heated to redness. The contents of the crucible, still hot, are poured out, and rapidly reduced to fragments in a copper mortar in such a manner as to have the pieces about the size of a pea, and without having too much finely powdered soda-lime mixed with it. While the matter is still hot it is placed in a flask and well-stoppered. In order that this reagent should contain no nitrogen it is indispensable to use in its preparation materials which contain no trace of nitrates. _Preparation of the Calcium Oxalate._—In a small copper vessel place 100 grams of oxalic acid and add gradually, bringing it to boiling, enough water to dissolve it. Afterwards place in the solution small portions of slaked lime in a state of powder, constantly testing it until turmeric paper indicates that there is a little lime in excess. It is then evaporated, stirring vigorously on the open fire, and the evaporation is finally finished on a steam-bath. The dried material is placed in a flask and well-stoppered. The oxalic acid which is used in this preparation should be free from every trace of nitrogen. _Preparation of the Litmus Solution._—Five grams of litmus are placed in a flask with a flat bottom. Afterwards a few cubic centimeters of ammonia are added, twenty five grams of crystallized sodium carbonate, and ten cubic centimeters of water. This mixture is left to digest for sometime, with frequent stirring, at a temperature of from 60°–80°. The digestion is finished in about four or five days, during which time, at intervals, a few drops of ammonia are added, sufficient to maintain always the ammoniacal odor. At the end of this time 200 cubic centimeters of water are added and the digestion allowed to continue several days more, still maintaining the solution alkaline with ammonia. A slight excess of hydrochloric acid is added, and the matter which is precipitated is received upon a filter where it is washed several times with cold water and allowed to dry at a low temperature. For use, from one to two grams of this dry precipitate are dissolved in 100 cubic centimeters of alcohol, and there is thus obtained a litmus solution of extreme sensibility. =403. Treatment of Soil Containing Nitrates.=—Nitrates exist in small quantities in all arable soils. When treated for nitrogen by the soda-lime method above described, a part of the nitric nitrogen is changed to the state of ammonia, while another part escapes estimation altogether, causing an error which it is important to point out. When the soils contain only small quantities of nitrates this error is insignificant and does not affect sensibly the results, but in the case of earths rich in nitrates it is necessary first to eliminate them before the determination of the nitrogen by the soda-lime method. The operation is carried on as follows: Twenty grams of the soil are washed on a small funnel, furnished with a plug of asbestos, with small quantities of pure water, in such a way as to cause thirty to forty cubic centimeters of water to pass through. The whole of the nitrate is thus removed. The soil is now dried and submitted to analysis by the soda-lime method as just described. There are removed with the nitrate only small traces of organic nitrogen, too small to influence the results of the analysis. If, however, it is desired to remove altogether this slight cause of error, evaporate the wash-waters, above described, to two or three cubic centimeters; add a few drops of a concentrated solution of ferrous chlorid and as much hydrochloric acid, and boil some minutes in order to drive off, in the state of nitrogen dioxid, all the nitric acid. The residue is evaporated to dryness and contains the traces of organic nitrogen. This is added to the soil which is to be treated by the soda-lime method. =404. Müller’s Method.=—The determination of nitrogen in the soil by soda-lime is carried on as follows by Müller:[269] Fifteen grams of fine earth, dried and mixed with a little sugar, are mixed with thirty grams of soda-lime in powder. The bottom of the combustion tube contains a little moist soda-lime, which is heated at the end of the operation at the same time that a current of pure hydrogen is made to pass through it, and the temperature of the tube is raised, little by little, to a distinct redness. The contents of the receiving bulbs are distilled, after the addition of water and soda, in the same apparatus which served in the estimation of nitrogen, by the kjeldahl method; the determinations and titrations are made also under the same conditions. Blank determinations are also made under the same conditions to determine the amount of correction to be made by the two methods. Soda-lime, heated with pure sugar, gave 0.0002 gram of nitrogen for a total weight of fifty-five grams of the soda-lime contained in the tube. The fuming sulfuric acid gave 0.0011 cubic centimeters of ammoniacal nitrogen for the volume of thirty cubic centimeters. The numbers obtained by the kjeldahl method in general, are lower than those obtained by the soda-lime method when no stearic or benzoic acid is used. The numbers obtained when stearic acid alone was used were sometimes inferior to those obtained by the soda-lime method. The numbers obtained when benzoic acid is used are, in general, about the same as those obtained by the soda-lime method. It would seem that the double distillation, outlined above, for the kjeldahl method, would not be necessary if due care were exercised in the first distillation. This variation, therefore, seems to be unnecessary. In the soda-lime method, time would be saved by the reception of the ammonia in standard acid, and its titration in the usual way, unless a further purification of the nitrogenous products of the combustion by the final distillation be desired. =405. Volumetric Determination of the Nitrogen.=—Instead of separating the nitrates, the total nitrogen in the soil can be determined directly by the classic method of Dumas, which consists in bringing the whole of the nitrogen into a gaseous state and afterwards measuring its volume. The following method illustrates the general principles of the determination: A glass combustion tube closed at one end, about one meter in length, is selected. In the bottom of this tube is placed some potassium bicarbonate in a crystalline form, in small pieces, filling the tube to a distance of about twenty centimeters. Afterwards copper oxid is placed to the depth of ten centimeters and finally a mixture of from twenty to thirty grams of the earth with thirty to forty grams of copper oxid in a fine state of subdivision, and about ten grams of metallic copper obtained by reducing the copper oxid by hydrogen. Next the tube is filled with copper oxid to a depth of from twenty to twenty-five centimeters, and afterwards with reduced copper to the depth of at least twenty-five centimeters, and after this another layer of copper oxid of about five centimeters, and finally a plug of asbestos. The combustion tube is closed with a stopper carrying a glass tube of about ninety centimeters in length, of which the extremity, bent into the form of a =ᥩ=, extends to a mercury trough. The glass combustion tube is surrounded with brass gauze, except that part which contains the potassium bicarbonate. The beginning of the operation consists in heating the tube to decompose a part of the potassium bicarbonate, until the whole of the apparatus is filled with carbon dioxid. In order to determine that the whole of the air has been expelled and that the apparatus is entirely filled with carbon dioxid, a part of the gas which is disengaged, is received into a jar filled with mercury, in which a little potash-lye has been placed. If the gas is entirely absorbed by the potash, so that there remain only unappreciable particles, the tube can be regarded as completely free of air. When assurance is given that the air is all out of the apparatus, a jar of about 300 cubic centimeters capacity, filled with mercury and containing from thirty to forty cubic centimeters of a solution of potash of a density of 42° baumé, is placed over the outlet tube. The combustion is commenced by heating the anterior part of the tube, avoiding the heating of the part containing the earth. When the first part of the tube has reached the red stage the part containing the earth is gradually heated in order to obtain a gentle evolution of gas. The temperature of the tube is carried to redness and the heating gradually carried back toward the closed extremity, but avoiding raising the temperature of the part containing the potassium bicarbonate. The red heat is continued as long as bubbles of gas are discharged into the reservoir. When the evolution of gas has ceased the apparatus is again filled with carbon dioxid for the purpose of driving out the last traces of nitrogen, by heating again the part of the tube containing the potassium bicarbonate. The evolution of the carbon dioxid should be maintained for about fifteen minutes. At the end of this time all the nitrogen will be found in the receiving jar. Sometimes a small quantity of nitrogen dioxid is formed incidentally in the operation. After waiting for a quarter of an hour, in order to permit all the carbon dioxid which may have escaped into the reservoir to be completely absorbed, the receiving jar is carried to a water-basin and the mercury allowed gradually to escape; its place being taken by the water. The gas is then transferred into an azotometer where its volume and temperature are read in the usual way. In order to absorb any nitrogen dioxid which may be admixed with the nitrogen itself, a little crystal of ferrous sulfate is introduced. The reservoir containing the nitrogen is carried to the mercury trough, and the water which it contains is nearly all run out in such a way as to be replaced with mercury, great care being exercised to avoid any escape of gas. Afterwards there is introduced over the mercury a crystal of ferrous sulfate and the azotometer is shaken until this crystal is dissolved by the water which it still contains. It is then allowed to remain for twenty hours. At the end of this time the nitrogen dioxid is absorbed and the volume of the gas is again read as before. One-half only of the total loss should be subtracted, since the volume of the nitrogen dioxid is twice the volume of the nitrogen itself. For the practice of this method, in connection with the use of a mercury pump, the directions which will be given under fertilizers may be consulted. =406. Estimation of Ammonia.=—Ammonia exists ordinarily only in very small quantities in the soil, since it is incessantly transformed into nitrate or diffused in the air. Nevertheless, it is sometimes interesting to determine its quantity. The method of determining the ammonia in soils is one of extreme delicacy on account of the small proportion therein, and the difficulty of expelling it without at the same time converting some of the organic nitrogen into ammoniacal compounds. The various methods employed for this purpose may be classified as follows: 1. Treatment of the soil with soda-lye in the cold, and the absorption of the ammonia given off by standard sulfuric acid. 2. The method of Boussingault, which consists in replacing the soda-lye with magnesia and distilling the ammonia at a boiling temperature, absorbing the distillate in a standard acid. 3. A modification of the above method, due to Schloesing, which consists first in extracting the ammonia by hydrochloric acid and subjecting the extract to distillation with magnesia. 4. The method of Knop consists in treating the soil in a closed cylinder with soda-lye containing bromin. The ammonia set free by the lye is decomposed in the presence of bromin into free nitrogen and hydrochloric acid. The nitrogen is collected and measured in an azotometer. The brom-soda-lye is prepared by dissolving 100 grams of sodium hydroxid in 1,200 cubic centimeters of water and adding twenty-five cubic centimeters of bromin. 5. The process described under 4, as shown by Baumann,[270] does not give accurate results and it has been modified by him as follows: Two hundred grams of soil are treated with 100 cubic centimeters of dilute hydrochloric acid (one part acid and four of water) free of ammonia; 300 cubic centimeters of ammonia-free distilled water are added and the whole digested for two hours with frequent stirring. If a soil contain much calcium carbonate larger quantities of acid must be used. Two hundred cubic centimeters of the filtrate are placed in an evolution flask, connected with an azotometer, with five grams of freshly burned magnesia. The mixture is then oxidized as follows: Ozone is generated by adding three parts by weight of sulfuric acid to one part of dry and powdered potassium permanganate. A stream of air is drawn through the ozone generator by an aspirator, and the ozone is conducted into a flask containing the hydrochloric acid extract of the soil and magnesia. The oxidation is completed in about ten minutes. The mixture is then brought into the evolution flask of the azotometer and the nitrogen set free and measured in the usual way. It has been shown that if asparagin or glutamin be present in the soil they are decomposed by the soda-lye and the results obtained are too high. It has been further proved that soils which contain a notable quantity of humus give, with soda-lye in the cold, a practically continuous evolution of ammonia. Moreover, soils which are rich in humus and which have been treated by distillation with magnesia give, on subsequent treatment with soda-lye, considerable additional quantities of ammonia. _Comparison of Methods of Estimating Ammonia._—Baumann has determined the ammonia-nitrogen in various soils by the soda-lime method; distillation of the hydrochloric acid extract with magnesia, and the azotometric method modified as indicated above. These methods will be designated as 1, 2, 3, respectively in the following table. METHOD. 1. 2. 3. Ammonia-nitrogen in one kilogram of soil. —————— —————— —————— No. of sample. Gram. Gram. Gram. 1 0.0448 0.02227 0.02781 2 0.0168 0.01105 0.01326 3 0.0336 0.01771 0.02214 4 0.0056 0.00443 0.00443 5 0.0280 0.02337 0.02894 6 0.0196 0.01243 0.01672 From the above figures it is seen that the method usually attributed to Schloesing gives uniformly higher numbers than either of the other processes, while the third gives slightly higher values than the second. =407. The Magnesia Distillation Process.=—If a sample of soil be distilled directly with magnesia and water, there is danger on the one side of not extracting all the ammonia, by reason of the absorbing power of these bodies, and on the other, of transforming into ammonia the nitrogen of the organic matters. It is therefore preferable to separate the ammonia from the soil in the form of chlorid, and to subject this extract to distillation. In fifty grams of the soil the humidity is determined by drying at 100° until there is no further loss of weight. The quantity of moisture being known, 200 grams of soil are taken and moistened with water, and then there is added, in small portions, some dilute hydrochloric acid, shaking frequently until the whole of the calcium carbonate present is decomposed. The liquor should remain acid at the end of the operation, but without containing a notable excess of acidity. Knowing beforehand the quantity of moisture contained in the 200 grams, water is added until the total quantity shall be equal to 500 cubic centimeters. The whole is then shaken and allowed to repose, and filtered rapidly, covering the funnel with a glass vessel and receiving the liquid which runs through in a flask with a narrow opening. Two hundred and fifty cubic centimeters of this liquor, or mixture, represent 100 grams of earth of known humidity. This quantity is introduced into a flask for determining the ammonia and five grams of calcined magnesia added. Before commencing the distillation, assurance should be had that the magnesia has completely saturated the acid in excess, and that the liquor is alkaline. If, by chance, the liquor should be still acid it would be necessary to add sufficient magnesia in order that the reaction should be manifestly alkaline. Afterwards the distillation is begun and the ammonia is received in an appropriate vessel containing one-tenth normal sulfuric acid and titrated in the usual way, or nesslerized. Inasmuch as the quantities of ammonia contained in the earth are generally very small it is necessary to be very particular in order to avoid errors. The distilled water which is employed should be deprived of all traces of ammonia by prolonged ebullition, and the hydrochloric acid should be distilled in the presence of a little sulfuric acid. The treatment with hydrochloric acid is for the purpose of destroying the absorbing properties of the soil for ammonia, and to permit this last to enter into solution as chlorid. When there is need of very great precision it is convenient to make a blank operation with the hydrochloric acid and water which are employed, in order to make a correction for the traces of ammonia which these reagents may contain. =408. Estimation of Ammoniacal and Amid Nitrogen by the Method of Berthelot and André.=[271]—Heat one hundred grams of earth for thirty hours on a steam-bath with about .500 cubic centimeters of dilute hydrochloric acid (fifteen grams of hydrochloric acid to 500 cubic centimeters of water). At the end of this time throw the contents of the flask on a filter and wash with hot water until acid reaction has ceased. Determine both the ammoniacal and amid nitrogen in the soluble, and the total nitrogen in the insoluble portion, the ammoniacal by distillation with magnesia, and the amid and total with soda-lime. _Example._ A soil contained 0.1669 per cent total nitrogen. Of this there were obtained: As ammoniacal nitrogen 13.7 per cent In the soluble part as amid nitrogen 56.2 „ „ In the insoluble part, total nitrogen 29.7 „ „ ———— Sum 99.6 „ „ _Treatment of the Insoluble Portion._—Treat the part insoluble in hydrochloric acid with a three per cent solution of potash on a steam-bath for thirty hours. Estimate the nitrogen remaining insoluble, from which the part dissolved can be determined by difference. The potash will dissolve usually about two-thirds of the remaining nitrogen. About ninety per cent of the total nitrogen present in an arable soil will be rendered soluble by successive treatment with acid and alkali. The reverse treatment will give practically the same result. It is therefore immaterial, from an analytical standpoint, whether the acid or alkali be used first. =409. Estimation of Volatile Nitrogenous Compounds Emitted by Arable Soil.=—The following method, due to Berthelot and André,[272] may be practiced: Porcelain pots, containing one kilogram of soil, are placed under bell-jars of fifty liters capacity adjusted to glass dishes designed to receive the waters of condensation. During the first period the pots are to be sprinkled from time to time, during the duration of the experiment, through the upper tubulature, so as to prevent the soil from becoming dry. The water is partly condensed on the sides of the bell-jar. It is removed each week through the inferior tubulature, treated with a little dilute sulfuric acid, and preserved for further study. A small vessel containing dilute sulfuric acid is placed near the porcelain pot for the purpose of collecting, as far as possible, the evolved ammonia. During the second period the pots are not sprinkled, the soil becomes dry and there is no longer any condensation of water on the walls of the bell-jar. The two periods should include about five months, from May to October. At the end of the second period the following determinations are to be made: 1. The ammonia absorbed by the dilute sulfuric acid. 2. The ammonia set free by distillation with magnesia, such as may have accumulated in the condensed water. 3. The organic nitrogen contained in the latter after elimination of the ammonia. This is determined by adding a slight excess of acid, evaporation to dryness, and combustion with soda-lime, or by moist combustion with sulfuric acid. Example: _Earth Employed._—One kilogram of sandy clay containing total nitrogen, 0.09 gram. Nitrogen in sprinkling water, 0.000048 gram. _Nitrogen in Exhaled Products._— FIRST PERIOD. SPRINKLING. Ammoniacal nitrogen collected in the dilute sulfuric 0.00012 gram. acid Ammoniacal nitrogen collected in the condensation waters 0.00012 „ Organic nitrogen in condensation waters 0.00220 „ ———————— Sum 0.00244 „ SECOND PERIOD. NO SPRINKLING. Ammoniacal nitrogen in dilute sulfuric acid 0.000007 gram. „ „ „ condensed water 0.000007 „ Organic „ „ „ „ 0.000040 „ ———————— Sum 0.000054 „ _Conclusions._—The exhalation of nitrogenous compounds takes place with a certain relative activity, about two milligrams in two months and a half, as long as the soil is kept moist by sprinkling. In the second period, without sprinkling, the exhalation is reduced to a mere trace. The vessel containing the dilute sulfuric acid placed near the porcelain pot absorbs only about one-half of the ammoniacal nitrogen set free. The nitrogen emitted under other forms than ammonia is, in every instance, greatly superior in quantity, and this is the most important of the observed phenomena. This is true at least with the kind of soil with which the experiment was made. With arable soil containing twenty times as much nitrogen as the soil described above this order is reversed,[273] the ammoniacal prevailing over the non-ammoniacal nitrogen volatilized. These phenomena are doubtless greatly influenced in soil under culture by microbes, and the lowest orders of vegetation to which are doubtless due the traces of non-ammoniacal volatile nitrogenous compounds, a sort of vegetable ptomaines. =410. General Conclusions.=—In the light of our present knowledge concerning the methods of nitrogen determination in the soil in the form of organic compounds and ammonia, moist combustion with sulfuric acid is to be preferred to the older soda-lime process. For the nitrogen combined as ammonia, the extraction of the sample with hydrochloric acid and subsequent distillation with an excess of freshly calcined magnesia, are recommended. For the study of the progressive decomposition of the nitrogenous compounds, the various processes devised by Berthelot and André are the best. The origin of the nitric acid in the soil, the methods of studying the various nitrifying organisms, and of estimating the nitric acid produced, will form the subject of the next part. NOTE.—At the Eleventh Annual Convention of the Association of Official Agricultural Chemists, held in Washington, August 23, 24 and 25, 1894, the following process of soil extraction was adopted as the official method: _Preparation of the Sample._—500 grams or more, of the air-dried soil, which may be either the original soil or that which has been passed through a sieve of coarser mesh, are sifted upon a sieve with circular openings one-half millimeter in diameter, rubbing, if necessary, with a rubber pestle in a mortar, until the fine earth has been separated as completely as possible from the particles that are too coarse to pass through the sieve. The fine earths thoroughly mixed and preserved in a tightly stoppered bottle from which the portions for analysis are weighed out. The coarse part is weighed and may be subjected to further examination, (as in _Bulletin 38, Div. of Chem._, pp. 65, 75 and 200.) It may sometimes be necessary to wash the soil through the one-half millimeter sieve with water, in which case proceed as directed on pp. 65 and 75 of the above _Bulletin_. The use of water is to be avoided whenever possible. _Determination of Moisture._—Heat two to five grams of the air-dried soil in a flat-bottomed, tared platinum dish; heat for five hours in a water-oven kept briskly boiling; cover the dish, cool in a desiccator, and weigh. Repeat the heating, cooling, and weighing at intervals of two hours till constant weight is found, and estimate the moisture by the loss of weight. Weigh rapidly to avoid absorption of moisture from the air. An air-bath must not be used in this determination. _Determination of Volatile Matter._—The platinum dish and soil used to determine moisture are used also to determine volatile matter. Heat the dish and dried soil to full redness until all organic matter is burned away. If the soil contain appreciable quantities of carbonates, the contents of the dish, after cooling, are to be moistened with a few drops of a saturated solution of ammonium carbonate, dried and heated to dull redness to expel ammonium salts, cooled in the desiccator and weighed. The loss in weight represents the organic matter, water of combination, ammonium salts, etc. _Extraction of Acid-Soluble Materials._—In the following scheme for soil analysis it is intended to use the air-dried soil from the sample bottle for each separate investigation. The determination of moisture, made once for all on a separate portion of air-dried soil, will afford the datum for calculating the results of analysis upon the soil dried at the temperature of boiling water. It is not desirable to ignite the soil before analysis or to heat it so as to change its chemical properties. The acid digestion is to be performed in a flask so arranged that the evaporation of acid shall be reduced to a minimum, but to take place under atmospheric pressure and at the temperature of boiling water. Any flask resistant to acids is suitable, but it is not necessary to use a condenser, as a simple bohemian glass tube eighteen inches in length will answer the purpose of preventing loss of acid. Where it is not desired to determine sulfur trioxid, an erlenmeyer fitted with a rubber stopper and hard glass tube will answer. The flask must be immersed in the water-bath up to the neck or at least to the level of the acid and the water must be kept boiling continuously during the digestion. In the following scheme, ten grams of soil are taken, this being a convenient quantity in most soils, in which the insoluble matter is about eighty per cent. If desired, a larger quantity of such soil may be taken, using a proportionately larger quantity of acid and making up the soil solution to a proportionately larger volume. In very sandy soils, where the proportion of insoluble matter is ninety per cent or more, twenty grams of soil are to be digested with 100 cubic centimeters of acid and the solution made up to 500 cubic centimeters or a larger quantity may be used, preserving the same proportions. It is very important that the analyst assure himself of the purity of all the reagents to be used in the analysis of soils before beginning the work. _Acid Digestion of the Soil._—Place ten grams of the air-dried soil in a 150 to 200 cubic centimeter bohemian flask, add 100 cubic centimeters of pure hydrochloric acid of specific gravity 1.115, insert the stopper with condensing tube, place in a water or steam-bath and digest for ten hours continuously at the temperature of boiling water, shaking once each hour. Pour the clear liquid from the flask into a small beaker, wash the residue out of the flask with distilled water on a filter adding the washings to the contents of the beaker. The residue after washing until free of acid, is to be dried and ignited as directed below. Add one or two cubic centimeters of nitric acid to the filtrate, and evaporate to dryness on the water-bath, finishing on a sand or air-bath to complete dryness; take up with hot water and a few cubic centimeters of hydrochloric acid, and again evaporate to complete dryness. Take up as before, filter and wash thoroughly with cold water or with hot water slightly acidified at first with hydrochloric acid. Cool and make up to 500 cubic centimeters. This is solution “A.” The residue is to be added to the main residue and the whole ignited and weighed, giving the insoluble matter. The determination of the various components of the solution remains essentially as described in the provisional methods of the Association which have already been given. It is directed that all results of soil analysis be calculated on the basis of the sample dried to constant weight at the temperature of boiling water. AUTHORITIES CITED IN PART SIXTH. Footnote 189: Annales de Chimie et de Physique, sixiéme serie, Tome 25, pp. 292, et seq. Footnote 190: L’Analyse du Sol, p. 14. 3. Die Landwirtschaftlichen Versuchs-Stationen, Band 38, S. 311. Footnote 191: Bulletin 38, Chemical Division United States Department of Agriculture, p. 201. Footnote 192: Untersuchung Landwirtschaftlich und Gewerblich Wichtiger Stoffe, S. 14. Footnote 193: Vid. op. cit. supra. Footnote 194: Vid. op. cit. 1. Footnote 195: Vid. op. cit. 3, Band 37, S. 279. Footnote 196: Journal of the Chemical Society, September, 1880, p. 617. Footnote 197: Wanklyn, Philosophical Magazine, Series 5, Vol. 5, p. 466. Footnote 198: Vid. op. cit. 1. Footnote 199: Traité d’Analyse des Matiéres Agricoles, p. 148. Footnote 200: Bulletin 38, Division of Chemistry, United States Department of Agriculture, pp. 84, et seq. Footnote 201: Encyclopedie Chimique, Tome 4, p. 182. Footnote 202: Die Landwirtschaftlichen Versuchs-Stationen, Band 37, S. 280. Footnote 203: Vid. op. cit. supra, Band 28, S. 229. Footnote 204: Comptes rendus, 1890, pp. 290, et seq. Footnote 205: Annales Agronomiques, 1890, p. 558. Footnote 206: Bulletin 13, Division of Chemistry, p. 590. Footnote 207: Bulletin de la Société Chimique, Serie 3, Tome 2, pp. 483, et seq. Footnote 208: Zeitschrift für analytische Chemie, Band 3, S. 165. Footnote 209: Petermann, L’Analyse du Sol, p. 20. Footnote 210: Zeitschrift für analytische Chemie, Band 3, S. 92. Footnote 211: Journal of the Chemical Society, March, 1894, p. 141. Footnote 212: Agricultural Science, January, 1894, p. 2. Footnote 213: American Journal of Science, Vol. 7, 1874, p. 20. Footnote 214: Geological and Agricultural Report of Kentucky, Vol. 3. Footnote 215: Bulletin 38, Division of Chemistry, p. 77. Footnote 216: Op. cit. supra, p. 83. Footnote 217: Die Landwirtschaftlichen Versuchs-Stationen, Band 37, S. 311. Footnote 218: Zeitschrift für analytische Chemie, Band 3, S. 92. Footnote 219: Traité d’Analyse des Matiéres Agricoles, p. 144. Footnote 220: Op. cit. 28, pp. 202, et seq. Footnote 221: Op. cit. 28, pp. 77, et seq. Footnote 222: Op. cit. 22, p. 21. Footnote 223: Manuscript communication to author. Footnote 224: Annales de la Science Agronomique, Huitiéme Année, Tome 1, p. 278. Footnote 225: Die Landwirtschaftlichen Versuchs-Stationen, Band 37, S. 311. Footnote 226: Comptes rendus, 1890, p. 289. Footnote 227: Thoms, Zur Werthschätzung der Ackererde, S. 120. Footnote 228: Le Stazioni Sperimentali Agrarie Italiane, Vol. 16, p. 679. Footnote 229: Crookes’ Select Methods in Chemical Analysis. Footnote 230: Chemiker Zeitung, Band 13, S. 1391. Footnote 231: Annales de Chimie et de Physique, serie sixiéme, Tome 15, p. 309. Footnote 232: Vid. op. cit. 37, pp. 270, et seq. Footnote 233: Chemiker Zeitung, Band 13, S. 726. Footnote 234: Die Agrikultur Chemische Versuchs-Station, Halle, a/S., S. 80. Footnote 235: Comptes rendus, Tome 107, pp. 999 and 1150. Footnote 236: Die Landwirtschaftlichen Versuchs-Stationen, Band 41, S. 453. Footnote 237: Bulletin de la Société Chimique de Paris, 1893, p. 343. Footnote 238: Die Agrikultur Versuchs-Station, Halle, a/S., S. 70. Footnote 239: Op. cit. supra., S. 68. Footnote 240: Op. cit. 37, p. 267. Footnote 241: L’Analyse du Sol, p. 20. Footnote 242: Op. cit. 1, pp. 303, et seq. Footnote 243: Op. cit. 40, S. 114. Footnote 244: Bulletin 38, Division of Chemistry, p. 80. Footnote 245: Zeitschrift für analytische Chemie, Band 3, S. 92. Footnote 246: Chemisches Centralblatt, 1861, p. 3. Footnote 247: Berichte der deutschen chemischen Gesellschaft, Band 26, S. 386. Footnote 248: Manuscript communication to author. Footnote 249: Op. cit. 37, p. 285. Footnote 250: Op. cit. 44, pp. 305, et seq. Footnote 251: Die Landwirtschaftlichen Versuchs-Stationen, Band 37, S. 284. Footnote 252: Op. et loc. cit. 58. Footnote 253: Op. et loc. cit. 41. Footnote 254: Op. et loc. cit. 37. Footnote 255: Op. et loc. cit. 58. Footnote 256: L’Analyse du Sol, p. 17. Footnote 257: Op. cit. 44, p. 308. Footnote 258: Op. cit. 37. Footnote 259: Op. cit. 64, Band 40, S. 251. Footnote 260: Bulletin de la Société Chimique, May, 1891, pp. 643, et seq. Footnote 261: Bulletin 38, Division of Chemistry, p. 204. Footnote 262: Bulletin 38, Division of Chemistry, p. 81. Footnote 263: Op. cit. 44, March, 1891, pp. 393, et seq. Footnote 264: Op. cit. 58, Band 31, S. 525. Footnote 265: Relatorio Annual do Instituo Agronomico do Estado de San Paulo (Brazil), 1892, p. 107. Footnote 266: Op. cit. 37, pp. 253, et. seq. Footnote 267: Op. cit. 44, Tome, 25, pp. 299, et seq. Footnote 268: Petermann, L’Analyse du Sol, p. 17. Footnote 269: Op. et. loc. cit. 76. Footnote 270: Die Landwirtschaftlichen Versuchs-Stationen, Band 33, Ss. 247, et seq. Footnote 271: Op. cit. 44, Tome 25, pp. 327, et seq. Footnote 272: Op. cit. 44, Tome 25, pp. 330, et seq. Footnote 273: Op. et loc. cit. supra. PART SEVENTH. THE ORIGIN AND ESTIMATION OF OXIDIZED NITROGEN IN SOILS, RAIN AND DRAINAGE WATERS. =411. Introductory Considerations.=—The estimation of oxidized nitrogen in the soil would properly find a place in the preceding part; but on account of the late progress in our knowledge of the source of this indispensable and costly plant food it has become necessary to give it especial attention. The present part will, therefore, be devoted to a brief statement of our present knowledge in respect of the origin of oxidized nitrogen, a description of the nitrifying ferments and methods for their isolation and determination and finally the most approved methods of estimating the ammonia, nitrous, and nitric acids formed thereby both in the soil and the waters pertaining thereto or proceeding therefrom. It is scarcely necessary to caution the reader not to consider this part in any sense a treatise on the bacteria active in soil chemistry. Its object is rather to place in the hands of the soil analyst data which will enable him to intelligently study the soil phenomena depending on these organisms and to determine the extent and character of their biological and chemical functions. These are matters which, up to the present time, have found no place in manuals dedicated to agricultural analysis. =412. Organic Nitrogen in the Soil.=—With the exception of the small quantities of nitric acid added to the soil directly by rain water, the whole of the supply of this substance is derived from the products of the oxidation of nitrogenous bodies. These products are either stored as the results of past nitrification or are formed synchronously with their consumption by the growing plant. Nitrogenous compounds are present as organic vegetable or animal remains and as humus. All vegetable and animal material deposited in or on the soil contains more or less of these proteid or nitrogenous matters while the amount of nitric acid supplied in this way is probably represented entirely by the quantity in the organism of the plant or animal and unabsorbed at the time of its death. In other words it is not demonstrated that nitrates or nitrites are in any sense a special product of plant growth save in the case of nitrifying organisms themselves which are supposed to be of a vegetable nature. Animal organisms do not in any sense assimilate nitric nitrogen. With most plants, the quantity of proteid nitrogen which they can deliver to the soil is in no case greater than the sum of organic and nitric nitrogen supplied in their food and they can therefore be regarded only as the carriers and conservers of this substance. On the other hand there are some plants notably those belonging to the leguminous family which permit of the development on their rootlets of colonies of bacteria which have the faculty of rendering atmospheric nitrogen available for plant growth. Whether or not there exist plants other than the micro-organisms mentioned which are capable of directly oxidizing and fixing atmospheric nitrogen is still an unanswered question. It is not probable, however, that the difficult task of oxidizing atmospheric or free nitrogen would be accomplished in nature in only one way. In fact it has already been established that organisms do exist which are capable of oxidizing free nitrogen in a manner wholly independent of other plant life and to produce weighable quantities of nitric acid when developed in media of mineral matters and pure carbohydrates to which free nitrogen has access. It is, therefore, fair to assume that the fixation of free nitrogen is a function of chemical activity quite independent of ordinary plant life and that the leguminous plants take no further part in this process than that of providing in their radical development a favorable nidus for the growth of the nitrifying organism. By the action of denitrifying organisms a portion of the nitrogen of nitric acid is constantly restored to a free state, a far larger portion, perhaps, than is fixed in the atmosphere itself by the action of electricity. Were it not, therefore, for the activity of the nitrifying ferments the stores of nitrogen available for growing plants would constantly become less. Instead of this being the case, however, it is probable that the contrary is true and that, by a wise system of agriculture, the total nitrogen at the disposal of plants may become greater and greater in quantity. =413. Development of Nitric and Nitrous Acids in Soils.=—Owing to the solubility of nitrates there can be but little accumulation of them in soils in those countries where there is any considerable amount of rain-fall. On the other hand in arid regions there may be found extensive deposits of nitrates. The occurrence of a certain quantity of nitrates in the soil, however, is essential to the growth of plants. Until within a few years little was known of the origin of nitric acid in the soil. The presence of nitrates in drainage waters was well established, likewise the consumption of nitric acid by the growing plant, but the method of its supply was unknown. In a general way it was said that the nitric acid came from electrical action and the oxidation of the albuminous bodies in the soil, but without specifying the manner in which this change takes place. The researches of Schloesing and Müntz, of Springer, Winogradsky, Frankland, Warington and others have demonstrated the fact that this oxidation is caused by means of bacteria and that the nitrates formed can be consumed and destroyed by other species of this organism. In the one case the process has been called nitrification and in the other denitrification.[274] The influence of these low organisms both in producing fertility in a soil and maintaining it in a state of fertility is of the highest importance. =414. Conditions Necessary for Nitrification.=—In order to properly understand the reasons for many of the steps in investigating a soil for nitrifying organisms, it will be useful to state the general conditions on which nitrification depends. The nitrifying organism, like every other one, first of all feels the necessity for food. In general, food which is given to microbes of all kinds consists of some organic matter together with the addition of mineral substances necessary to growth. These substances in general are phosphoric acid, potash, and lime. Of these articles of bacterial food phosphoric acid seems to be the most important. With the nitrifying organisms, however, it has been found that the organic matter can be omitted. In fact, as will be seen further on, the omission of organic matter supplies the best condition for the proper isolation of the organisms. In other words some forms of the nitrifying organisms have the property of subsisting wholly on mineral substances, _i. e._, are true vegetables. The presence of oxygen is also necessary to the growth of the common nitro-organisms. In an atmosphere deprived of oxygen or in which the oxygen is reduced to a very low percentage, the process of nitrification is retarded or stopped as the oxygen diminishes or disappears. The presence of a base with which the nitrous or nitric acid formed may unite is also essential to the proper conduct of the process. For this reason the nitrification should take place in a solution which is feebly alkaline or in the presence of a base which can be easily decomposed so that no acidity can take place. Calcium carbonate is a base well suited to favor the nitrifying process and its presence in a soil favors the rapid oxidation of proteid matter. The mistake must not be made, however, of supposing that an excess of alkali would favor nitrification. The contrary is true. A slight excess of alkali may prevent nitrification altogether when it is due to the common organisms present in an arable soil. It may be that in soils charged with alkali a different organism exists which is capable of exercising its functions when the alkali is in excess. The temperature to which the nitrifying body is subjected is also a matter of importance. The nitrifying organisms have the property of remaining active at lower temperatures than most bodies of their class. On the contrary their action is retarded and destroyed by high temperatures. The most favorable temperature for nitrification is about that of blood heat; _viz._, 37°. At 50° the organism shows very little activity and at 55° its activity ceases altogether. Nitrification, however, according to Warington, cannot be started in a solution if the initial temperature is 40°. Desiccation has the same retarding influence on nitrification that a high temperature has. Even thoroughly air-drying a soil may destroy its nitrifying qualities. Darkness is also necessary to the proper progress of nitrification. In a strong light, the activity of the organism is very much diminished or destroyed altogether. A bright light like sunshine may even stop nitrification which has set in. =415. Effect of Potassium Salts on Rate of Nitrification.=—Dumont and Crochetelle have described some experiments to determine the effect of potassium salts alone and in combination with lime on nitrification.[275] Soil rich in vegetable mold (18.5 per cent of humus and 0.29 per cent of lime) was treated with varying amounts of potassium sulfate and carbonate and kept for twenty days at 25°. In the untreated soil the amount of nitric acid produced was twenty-five parts per million. When potassium carbonate was applied in quantities of from one-tenth to six per cent the amount of nitric acid increased from forty-seven parts per million to 438 parts when four and one-half per cent of the potassium salt were used. Larger quantities caused a decrease in the amount of nitric acid produced. Very little effect, on the contrary, was produced by the action of potassium sulfate. When one-half per cent was employed the quantity of nitric acid formed rose to fifty parts per million, while with quantities as high as five per cent it fell below the normal; _viz._, twenty-five parts per million. When calcium carbonate was added to the soil in conjunction with potassium sulfate there was a marked increase in the amount of nitrogen oxidized. The activity of potassium sulfate in promoting nitrification is therefore increased by the presence of the calcium salt, potassium carbonate and calcium sulfate being formed. =416. Production of Nitrous and Nitric Acids.=—In the following pages the study of the methods of isolating the nitrous and nitric ferments will be considered as one process, the final isolation of the two classes of bodies being the result of their synchronous cultivation in appropriate media. The special process of the production of ammonia by oxidation is not so well-known, and will therefore be described in brief. It is now generally conceded that the action of the nitrous organism is precedent to that of the nitric, but the two processes go on so nearly together as to prevent the accumulation of any large quantities of the lower salt in the soil. Whether or not the formation of ammonia precedes that of nitrous acid is still a subject for experimental demonstration. Chemically, both nitrous acid and ammonia may be produced by the reduction of nitric acid. In nature, the reverse of this process may be the customary method. =417. Production of Ammonia in the Soil by the Action of Microbes.=—It is highly probable that organic nitrogen in the soil in passing into the form of nitric acid exists at some period of the process in the form of ammonia. Marchal has isolated and studied some of these ammonia-making bacteria.[276] Bacillus mycoides is the most active of these organisms. It occurs constantly in surface soils and is present in the air and in natural waters. In decomposing albumen it produces a strongly alkaline solution due to ammonium carbonate. Organic carbon, during this process, is converted chiefly into carbon dioxid, but small quantities of formic, propionic, and butyric acids are also produced. Any organic sulfur which is present is converted into acid. No hydrogen or nitrogen is eliminated in a free state. While slight alkalinity is favorable to the development of this bacterium, yet it may be propagated in a feeble sulfuric acid solution when the acid is less than one per cent. The greatest activity of this organism is manifested at 30°. Below 5° and above 42° no ammonia is produced. The bacillus will not develop in an atmosphere of hydrogen or carbon dioxid, except in solutions of organic matter and nitrate. In addition to its action on egg albumen it decomposes other proteid bodies as well as leucin, tyrosin, creatin, and asparagin. It, however, does not oxidize urea, nor does it develop in solutions of ammonium salts and nitrates, except as mentioned above. When soluble carbohydrates are present, acids are formed. It is concluded from these experiments that the final oxidation of organic nitrogenous matter is preceded by its conversion into ammonium carbonate. =418. Summary of Statements.=—All nitrogenous matters which would be naturally present in the soil may become subject to nitrification when the proper conditions are supplied. Munro has also succeeded in nitrifying ethylamin, thiocyanates, and gelatin, urea, asparagin, and the albuminoids of milk and rapeseed. The products of nitrification are ammonia, nitrous or nitric acid, carbon dioxid, and water. The ammonia and nitrous acid may not appear in soils as the final products of nitrification, as the nitric organism attacks the latter at once and converts it into nitric acid. Nitrous acid and ammonia may also be produced in soils as one of the retrograde steps in denitrification. To summarize the conditions necessary for nitrification it may be said that first, the proper material must be supplied; _viz._, an organic or inorganic nitrogenous compound capable of oxidation. In the second place, the medium must be faintly alkaline, the temperature must not be too high, the nitrifying organisms must have abundant food, and the process must take place in the dark. =419. Order of Oxidation.=—It is quite definitely determined that activity of the ammoniacal and nitrous organisms is the first step in the process, since the nitric organism appears to have no power whatever to oxidize proteid compounds; while, on the other hand, the nitrous organism can not, in any case, complete the conversion of nitrous into nitric acid. The conditions which permit certain organisms to oxidize free nitrogen have not been definitely determined. The presence of such bodies in the tubercles attached to the rootlets of certain leguminous plants has been established. Lately, Winogradsky has isolated from the soil a nitrifying organism which is capable of converting free nitrogen into forms suited to nourish plant growth. This organism is cultivated in dextrose with careful exclusion of all nitrogen, save that which exists in the air carefully freed of every trace of ammonia or oxidized nitrogen. Under the influence of the growth of this organism the sugar undergoes a butyric fermentation, and nitrogen in an oxidized form is assimilated in an amount apparently equal to about one five-hundredth of the sugar consumed. This result leads Warington[277] to remark that it is a fact of extraordinary interest, both to the physiologist and chemist, that a vegetable organism should be able to acquire from the air all the nitrogen it needs. =420. The Nitrification of Ammonia.=—The same organism which converts organic nitrogen into nitrous acid acts also on ammonia and its compounds with a similar result. In fact, the formation of ammonia may be regarded as one of the stages on the road from albuminoid to nitric nitrogen. Data have been collected by Schloesing on the nitrification of ammonia taking place in arable soil, tending to show that this phenomenon is accomplished without appreciable loss of nitrogen in the gaseous state.[278] This, however, does not hold good when the quantity of ammonium carbonate introduced into the earth is largely increased. In two experiments, conducted by Schloesing, with a larger quantity of ammonium carbonate, the loss of nitrogen was very notable. In certain conditions the production of nitrous acid may take place, and it is interesting to know whether the appearance of nitrites has any influence on the disengagement of free nitrogen. In order to determine this question a solution of calcium nitrite was prepared by decomposing silver nitrite with calcium chlorid. From the results of the experiments made it was seen that the nitrites were only the results of a retarded and partially incomplete nitrification. They are, moreover, thus an obstacle to the normal work of the nitrifying organisms. It is also established that when they are present a disengagement of gaseous nitrogen takes place, whether the nitrites are formed during the progress of the experiment, or whether they were originally present. However, it is not best to say that the nitrites themselves have been the cause of the disengagement of the nitrogen. It may happen that the disengagement of the nitrogen and the presence of nitrites are simply simultaneous and due to one and the same cause. The destruction of nitrates in the midst of reducing agents furnishes, according to the nature of these bodies and the circumstances, nitrous acid, nitrogen dioxid, nitrogen protoxid, free nitrogen, and even ammonia. This destruction of nitrates and the appearance of oxids of nitrogen and of free nitrogen are more likely to be due to the presence of a separate denitrifying ferment as pointed out by Springer than to have arisen in the manner mentioned above by Schloesing. In the present state of our knowledge, moreover, we can hardly regard the presence of nitrites as an obstacle to complete nitrification. On the other hand, it seems to be well established that the production of nitrites or ammonia is a necessary step between organic nitrogen and nitric acid. =421. Occurrence of Nitrifying Organisms.=—According to the observations of Schloesing and Müntz the nitrifying organisms are widely distributed.[279] Arable soil containing considerable humus seems to be the medium in which they grow most freely and in which they accomplish their most important functions. Sewage waters are also rich in nitrifying ferments, and, in fact, all waters containing organic matter. They are also found in running waters but not in great numbers. They affect chiefly the surface of bodies, and especially are found on the bottom of culture-flasks. These authors have not found the nitrifying organisms in normal air. They could not seed sterilized flasks by admitting air freely. The absence of these ferments from the air is explained by reason of their sensitiveness to desiccation. The method used by Schloesing and Müntz for the separation of the organism consisted in the preparation of original and subcultures in sterilized solutions containing nitrifiable matters. The proof of isolation was assumed when a given subculture contained only one kind of organism as seen with the microscope. The appearance of this organism, as described by the authors, was that of the later isolations by Warington and Winogradsky, but the method used could hardly now be regarded as decisive. =422. Determination of Nitrifying Power of Soils.=—In studying the distribution of the nitrifying organisms in a soil the general method of procedure is based on the production of nitrification in a convenient solution by the organisms present in a given sample of soil. If the solution seeded with the given portion of soil remain unaffected, it will show that there were no nitrifying organisms present in the seed used. On the other hand, the vigor of the nitrifying process when once it is started, may be taken as an evidence of the number and activity of the organisms in the soil, a sample of which was used for seed. =423. Composition of the Culture Medium.=—The solution recommended by Warington for the culture and isolation of the nitrifying ferments has the following composition: Ammonium chlorid 80 milligrams. Sodium potassium tartrate 80 „ Potassium phosphate 40 „ Magnesium sulfate 20 „ calcium carbonate about 200 „ Pure bacteria-free water to make one liter. =424. Apparatus and Manipulation.=—The experiments are conducted in short, wide-mouthed bottles. The initial volume of the solution in each bottle is 100 cubic centimeters, and the bottle should be of such size as to give a depth of liquid of from three to five centimeters. The neck of the bottle is closed with a plug of cotton and this is protected from dust by tying over it a cap of filter paper. Arranged in this way, filtered air has free access to the solution. The bottle with the solution thus protected is placed in a water-oven and kept near the temperature of boiling water for six to eight hours to destroy any organisms present. When cool, the solution is ready for use. The calcium carbonate used should be prepared by precipitation and added in a moist state. The calcium carbonate solution should be added after the sterilization of the liquid, the precipitated carbonate being boiled just before it is added. _Preparation of Seed._—The seed employed to start the nitrification should be a small quantity of fresh soil, usually about one-tenth of a gram. If a previously nitrified solution be used for seed it should be thoroughly shaken and about one cubic centimeter of the solution removed for seeding the new bottle. In introducing the nitrifying liquor into the bottle the plug should be lifted slightly and a small pipette inserted by means of which the liquor is added. The operation should be carried on in a room perfectly free from dust and to which no one but the operator has access. The greatest care should be exercised to prevent any particles of matter entering the solution except that which is purposely added. In withdrawing the liquor from the nitrifying solution cotton wool should be pressed around the top of the pipette so that the entering air may be filtered before admission to the interior of the bottle. The pipette which is used should be kept in boiling water until it is required for use. After use it should be washed and replaced in boiling water until again required. After seeding, the bottles should be placed in a dark cupboard and exposed to the ordinary temperature of the laboratory. If a higher or stated temperature be desired, the bottle should be placed in a metal box the temperature of which can be regulated to any degree. _Test of the Commencement of Nitrification._—The beginning of the nitrification can be determined in a solution by testing it with diphenylamin. One cubic centimeter of the solution withdrawn as above indicated, is placed in a small beaker, a drop of solution of diphenylamin sulfate in sulfuric acid added, and then two cubic centimeters of concentrated sulfuric acid and the contents of the beaker well shaken. The development of a violet-blue color shows the presence of nitric or nitrous acid. This test will detect one part of nitric nitrogen in twenty million of water. _Determining the Progress of Nitrification._—The progress of nitrification is determined by repeated examinations for ammonia by nesslerizing, and for nitrous acid with metaphenylenediamin. Each experiment is made with five cubic centimeters of the solution withdrawn as above indicated and placed in test-tubes, always of the same size. The reaction with the nessler solution is then made by adding it in the usual way. The colorations are recorded as, trace, small, moderate, considerable, large, and abundant. If the change produced by the organism consisted in the formation of nitrites only, the ammonia in the original solution would fall from _large_ to _trace_, while the nitrous acid would increase from _trace_ to _large_. If the nitrification consisted in the production of nitrates only, the ammonia would diminish without any corresponding production of nitrous acid. In mother solutions which contain ammonium carbonate instead of sulfate, it should not be forgotten that the ammonia might gradually disappear owing to the volatilization of the carbonate without any corresponding production of free nitrites or nitrates. The complete disappearance of the ammonia in the above experiments shows the completion of the process. =425. To Determine the Distribution of the Nitrifying Organism in the Soil.=—The principle on which the determination of the distribution of the nitrifying organism in the soil depends, rests upon seeding the growth solutions with samples of soil taken at different depths and carefully protected from the time of sampling until the time of seeding from any admixture of accidental organisms. The method of Warington is the simplest and best to follow.[280] The samples of soil are taken by digging a pit of convenient depth usually from eight to ten feet. A fresh surface is then cut on one of the sides of the pit at the spot selected for sampling. This surface is scraped with a freshly ignited platinum spatula. The spatula should then be washed, re-ignited, and cooled, and a small portion of the soil, at the depth required, detached with the spatula and transferred at once into one of the growth bottles already described. The growth solution best suited for the purpose contains four cubic centimeters of urine per liter. Each bottle should also contain some freshly precipitated calcium carbonate. In sterilizing urine solutions the calcium carbonate should be added before the heating instead of afterwards. The quantity of soil taken for each seeding should be about one-tenth of a gram. Inasmuch as the cotton stopper has to be lifted to introduce the soil, opportunity is given for the entrance of any organisms floating in the air. Experience, however, has shown that air free from soil dust very seldom contains nitrifying organisms. The seeded bottles are placed in a dark cupboard of moderate temperature as already described. =426. Sterilized Urine Solution.=—The sterilized urine solution used for the determination of the distribution of the nitrifying organisms in the soil, is made by taking four cubic centimeters of healthy urine, diluting to one liter, adding some freshly precipitated calcium carbonate, stoppering with cotton wool and heating for several hours at the boiling temperature of water. As a result of Warington’s experiments it was shown that the nitrifying organism in the soil did not exist, at least in portions of one-tenth of a gram, to a greater depth than eighteen inches. In only one case was nitrification produced from a sample of soil taken at a greater depth and this may have been due to the accidental introduction of organisms from other sources. It may be assumed that any long delay in the commencement of nitrification under favorable conditions, implies the presence of a very limited quantity of organisms in the solution. Thus a comparative study of the period of incubation and the progress of nitrification in solutions seeded with soils taken at different depths or at different places, becomes a fair index of the number and vitality of the nitrifying organisms contained therein. =427. Depth to Which Micro-Organisms are Found.=—Koch states that at the depth of about one meter, the soil is nearly free from every kind of bacteria.[281] These observations have been corroborated by Pumpelly and Smyth who find that no infection of a bacterial nature is produced in a sterilized solution from samples of clay taken at the depth of nine feet below the surface.[282] It is evident from the nature of the experiments above described that the nitrifying processes go on almost exclusively in those portions of the soil which are subject to cultivation, while in the subsoil and below the processes of nitrification are either retarded or arrested. Any stores of nitrogenous matter, therefore, in an insoluble state, resting in the subsoil, are preserved from oxidation and consequent waste until such time as they may be removed to near the surface. =428. Isolation of the Nitrous and Nitric Organisms in the Soil.=—The action of the organisms which produce nitrification either in form of nitrites or nitrates, having been thoroughly established, and the method of testing the soil therefor given, it remains to describe a method by means of which these organisms in the soil may be isolated and obtained in a state of purity. The difficulties attending this process are extremely great on account of the similarity of the two organisms. All earlier attempts to make pure cultures of the two separate organisms were attended with but little success. According to Winogradsky the method of culture on gelatin so long practiced is not to be relied upon.[283] It is very difficult to eliminate by this process the organisms which grow rapidly in gelatin and which mature their colonies in two or three days, but where they require eight or ten days to produce a colony the method is successful. In fact, by the gelatin process as it was at first practiced, a good deal was owing to chance, but sometimes by a happy accident a pure nitro-bacterium might be isolated. Formerly it was considered that a liquid could be regarded as sterile if it gave no growth upon gelatin. It has, however, now been demonstrated that a liquid may contain large numbers of nitro-bacteria and still produce no growth upon gelatin. However, for the organisms which accompany the nitro-bacteria in soils, it is regarded as certain that if no growth on gelatin is produced by them they are absent. Therefore in the case of a solution which has been seeded with a soil, if it can be brought to such a state as to produce no growth on gelatin, it may be safely assumed that it contains no bacterial organisms save those which are capable of producing nitrites or nitrates. Therefore if such a solution produce nitrification and at the same time no growth upon gelatin, it may be considered as a proof of the isolation of the nitro-organisms from all others. This method was also worked out independently by Mr. and Mrs. Frankland.[284] Winogradsky says further he confesses that he has advanced these views only provisionally and without being convinced of their infallibility. Strictly speaking, the proof of seeding gelatin is not sufficient alone because the absence of growth can not be regarded as the exclusive privilege of the nitro-bacteria. Such might be the case sometimes for an accidental mixture of microbes, introduced with any given sample of soil into the cultures, but the criterion is not absolute. Microbes, for example, of a sulfurous or ferruginous nature may be cited, for which the gelatin layer is not only unfavorable but even fatal. It may thus happen that there may be eliminated from the solution all that will grow upon gelatin without freeing it from some special kinds of cultures, refractory like the nitro-bacteria, but which might reappear if they should be resown in some favorable nutritive solution. On account of this fault in the process, Winogradsky has been impressed with the necessity of bringing out a better method. In using the gelatin media it is necessary to find the one that is suited to nourish these organisms, which would evidently be the way promising the greatest success. This having been found, and those organisms which produce colonies being easily recognizable, a great step towards the solution of the problem will have been made and the more so as the medium would be at the same time absolutely unfavorable to other forms of microbes. On account of the slow degree of development of the nitro-organisms, all others would probably have opportunity to grow and strengthen to their exclusion, unless these interfering organisms could be completely removed. =429. The Culture Solution.=—The culture-solution, first proposed by Winogradsky, had the following composition: To ten grams of gelatin or one part of agar-agar in 100 cubic centimeters of water add potassium phosphate, one-tenth of a gram; magnesium sulfate, five-hundredths of a gram; calcium chlorid, trace; and sodium carbonate, half a gram. The solution being sterilized in the usual way by heating, there are added to it a few cubic centimeters of a sterilized solution containing two-tenths per cent of ammonium sulfate. Such a solution has been proved to be very favorable to nitro-organisms. Nevertheless the experiments with such solutions gave no definite results and they were abandoned. The non-success of this method led Winogradsky to adopt a nitrifying solution which absolutely excluded all organic substances. Instead of using an animal or vegetable gelatinous substance he used one of a mineral nature, first proposed by Graham and Kühne.[285] Two of these gelatinous mineral substances were considered; _viz._, the aluminum hydroxid and the hydrate of silica. The latter was chosen. =430. Preparation of the Mineral Gelatinous Solution.=—The soluble glass which is found in commerce is generally of a thick, sirupy consistence. It is first diluted with three times its volume of water. One hundred cubic centimeters of this liquid are poured with constant stirring into fifty cubic centimeters of dilute hydrochloric acid and the mixture placed in a dialyzer. It is useless to employ a standard solution of silica. All that is necessary is to submit to dialysis a liquid with an excess of acid and sufficiently dilute not to be exposed to the danger of being spontaneously gelatinized in the dialyzer. The dialyzer is left for one day in running water and two days in distilled water, often renewed. The solution is then ready for use. This is the case when it is no longer rendered turbid on the addition of silver nitrate, showing that the hydrochloric acid has been entirely extracted. The solution is then to be sterilized by boiling, and preserved in a glass flask closed with a plug of cotton. More recent instructions by Winogradsky for preparing the gelatinous silica recommend dialyzing the soluble glass after treatment with hydrochloric acid in a parchment tube.[286] The proportions of silicate and acid are 100 cubic centimeters of the silicate solution (1.06 specific gravity) and 100 cubic centimeters of hydrochloric acid (1.1 specific gravity). With a dialyzing tube placed two days in running water and one day in distilled water frequently changed it will be found that the acid is completely removed. One hundred cubic centimeters of the residual liquor giving no reaction for hydrochloric acid are concentrated to twenty cubic centimeters. When cold there is added one cubic centimeter each of a solution of ammonium sulfate and of sodium carbonate, together with corresponding quantities of the other nutrient salts commonly employed. The ammonium sulfate should never exceed two to two and a half, and the sodium carbonate four parts per thousand. To the flask containing the above substances is added one drop of the seed-liquor, which may be a soil water or a drop from some previous culture. The flask is shaken and the mixture poured into a low circular glass dish which is covered by one slightly larger in diameter (Petri double dish). To the liquid in the dish is added a drop of a cold saturated solution of common salt, and it is then stirred with a platinum spatula. The addition of the salt greatly favors the setting of the jelly. The jelly may set in from two to three hours, but a longer time secures better results in the end. In employing these preparations as seed, after the organisms have grown, it is absolutely necessary to use the isolated cellules and not the aggregated masses (zoöglœæ). The latter are rarely free of foreign germs which adhere to their gelatinous envelope. Since the zoöglœæ can not be broken up by any artificial means it is necessary to await their spontaneous disintegration in order to separate the mobile monads. The opalescence of the culture-liquid is a sure index of this separation. The particles of mineral gelatin to be used as seed for nitrifying are best taken as follows: A glass tube is drawn out immediately preceding the operation, until the end is as fine as a hair. The surface of the mineral gelatin is magnified by means of a dissecting microscope magnifying 80 to 100, to the proper degree and the preparation table is so arranged as to give a perfect support to the right hand which should hold the filament of glass. The smallest colony is then pricked with the needle and the end of the glass is broken and dropped into the flask which is to be seeded. The seed is thus selected in as small a particle as may be desired, only a few cells, but it can always be ascertained with certainty that some of the particles have been obtained by this operation. The method of cultivation on mineral jelly is considered by Winogradsky an important resource in the study of the nitrifying organisms. It removes the chief difficulties heretofore existing in discovering and characterizing these organisms among the innumerable micro-organisms of the soil. The long series of cultures necessary to separate the organisms are rendered nugatory. By directly introducing a little of the earth into the silicic jelly the active organisms in nitrification can be at once discovered. It is preferable, however, as indicated below, to previously produce a nitrification in an aqueous solution by a trace of earth and to take from it the seed for impregnating the solid medium. In order to show at once a proof of its nitrifying character, it is only necessary to take a small bit of the mineral jelly, the size of a grain of rye, and to throw it into a little sulfuric acid which has been treated with diphenylamin. There is at once formed a blue spot equal in intensity to a saturated solution of anilin blue. In regard to the growths which nitro-organisms make in a medium of the kind described, they are far from being so marked as are those produced by ordinary micro-organisms. A nitro-bacterium is not capable of the energy of growth which is recognized for the greater number of microbes. The colonies contained in the gelatin always remain small. The largest among them are just visible to the naked eye like white points. Along the striae, on the contrary, there is formed quite a thick white crust. To the naked eye, in general, there is nothing very characteristic in the formation of colonies in a medium of this nature. But this impression changes altogether when the placques are examined with a low magnifying power. The colonies, especially those of the interior surface, reveal then an aspect so curious as to be well remembered when once seen. This mineral gelatin, as has already been noticed, is very unfavorable to the growth of microbes other than nitro-bacteria and becomes altered only under the action of the air. If the placques be carefully preserved from desiccation the culture of these organisms can be continued for several weeks. Although they do not seem to increase, the colonies, as well as the jelly, are still in a good condition at the end of that time. Nevertheless the expectation that this medium would prevent the formation of any foreign organism has not been realized. Some of the organisms which accompany the nitro-bacteria in soil, also grow upon the silicic jelly; but they do not form colonies, properly so-called, and their growth is extremely slow. They generally make their appearance before the nitro-bacteria and spread exclusively upon the surface in form of white spots, so transparent that without careful examination they would not be discovered. Having reached a certain size the spots do not change during entire weeks. This circumstance renders the operations of isolation somewhat delicate, but does not prevent them. =431. Preparation and Treatment of the Solution to be Nitrified.=—The organisms having been grown on the siliceous gelatin in the manner described they are tested for their nitrifying power as follows: The mineral solution which is to be nitrified with the above preparation is composed of ammonium sulfate, four-tenths gram; magnesium sulfate, half a gram; potassium phosphate, one-tenth gram; calcium chlorid, trace; sodium carbonate, six-tenths to nine-tenths gram; and distilled water, 100 cubic centimeters. The sulfates with the calcium chlorid on the one hand, and the phosphate and carbonate on the other, are dissolved separately and the two solutions sterilized separately and mixed after cooling. The seeding is then done as described above. =432. Isolation of the Nitrous and Nitric Organisms.=—Instead of proceeding immediately to the isolation of special organisms in the soil, the preliminary period of purification is prolonged by Winogradsky by allowing the free growth to take place of all the organisms which can be maintained in the ordinary medium.[287] The composition of the culture solution employed is as follows: Distilled water, 1,000 parts; potassium phosphate, one part; magnesium sulfate, half a part; calcium chlorid, trace. Each flask receives besides this some magnesium carbonate, freshly washed with boiling water and added in slight excess. The flasks thus charged are sterilized, and after sterilization there are added two cubic centimeters of a solution of two per cent of ammonium sulfate, which, when added to fifteen or twenty cubic centimeters of liquid give from two to two and a half parts per thousand. They are then seeded with soil. The reasons for this preliminary treatment are as follows: First, all the observations upon the enfeeblement of the oxidizing power of these organisms have been made upon cultures seeded simply by the fresh soil, and in cultures derived therefrom. In the second place, the existence of the two forms, one nitrous and the other nitric, prevents at once the isolation of a single organism. Samples of soil from Europe, Africa, Asia, Australia, and America, were used for seed for the experiments. First, the cultures were made by seeding with a small quantity of each of these samples of soil, and each one of these cultures served as a point of departure for a series of subcultures. The temperature of the cultures should be kept constantly at 30°. The method of following the nitrification adopted by Winogradsky is essentially that of Warington, the percentage of ammonia remaining at any time being determined by nesslerizing. To detect the presence of nitric acid the nitrous acid is decomposed by boiling with ammonium chlorid in excess, or with urea, and then diphenylamin is used as a reagent. By treatment with ammonium chlorid and boiling, the ammonium nitrite is resolved into free nitrogen and water as indicated by the equation NH₄NO₂ = N₂ + 2H₂O. Or the total oxidized nitrogen may be estimated by the Schloesing method or by any of the standard methods hereafter given. The nitrous acid is then determined by potassium permanganate and the nitric acid by difference. A great difference is to be noted between freshly taken earth and that which has been kept for a long while, especially when sealed. With fresh earth taken near the surface a mere trace is sufficient to produce nitrification. With samples of earth which have been kept for a long while and thoroughly dried, several grams must be added in order to secure perfect nitrification. The period of incubation with the samples of earth ranges from three to twenty days. The beginning of the phenomenon is revealed by the appearance of nitrous acid, of which the quantity is increased very rapidly, but in the end it disappears and is transformed into nitric acid. =433. Statement of the Results.=—The method of stating the results of examination of soils for nitrifying organisms is illustrated by the following example: Soil from Zurich. The culture was seeded on the 11th of October, one gram of soil being taken. On the 20th of October the nitrous acid had reached its maximum of intensity and there was no ammonia left. On the 29th of October the nitrous acid remained almost stationary and there was hardly any nitric acid present. On the 1st of November the reaction for nitrous acid began to decrease. On the 5th of November the reaction for nitric acid was very intense. On the 11th of November the nitrous acid had all disappeared except a mere trace. The above order of phenomena was observed with all the samples of soil tried, from which it is concluded with certainty that nitrifying organisms transplanted directly from their natural medium in the soil into a liquid easily nitrifiable produce at once nitrous acid in abundance. The phenomenon of nitrification is divided into two periods therefore, of which the first is devoted to the production of nitrites, and the second consists in the oxidation of the nitrites, and this does not commence until the total disappearance of the ammonia. Occasionally the formation and oxidation of the nitrites practically go on together, but never equally, the oxidation of the nitrites being always sensibly behind their formation. =434. Method for Subcultures.=—From the mother cultures described above, Winogradsky makes subcultures as follows: The solution to be nitrified is prepared as in the mother cultures. The seeding is accomplished by adding a small quantity of the liquor of the mother culture after shaking. Subcultures can be made in this way to the seventh generation. In respect of the oxidation of the nitrites the results may be entered as negative if they have not disappeared at the end of two months. To determine whether the process of oxidizing the nitrites is in progress or not the total nitrous acid is estimated, and the process repeated at the end of eight or ten days. Should there be no diminution of the nitrous acid within this time it may be considered that the further oxidizing action is not taking place. =435. Use of a Solid Medium.=—It may be justly claimed that the action of nitrifying organisms in a liquid is not to be compared with their action in a solid medium, such as a soil which is their natural habitat. It might be, therefore, that the inability of the nitrous organism to produce nitrates is due to the nature of the medium in which it is cultivated. Winogradsky in order to determine this question cultivated the organism in a solid medium of two kinds, first a silicate gelatin impregnated with an ammonium salt and second in sterilized earth. The silicate jelly is prepared as follows: Mix a jelly of silica containing some ammonium sulfate with sterilized soil. The seeding is done with one of the subcultures which no longer has the power of producing nitrates. In the case of the jelly the seeding is accomplished as follows: A minute drop of a culture liquid is taken with a capillary glass tube and applied in striae to different parts of the solid jelly; or a minute drop of the culture liquid may be mixed with the jelly before solidification. The Petri dishes in which these cultures are made can be preserved in a moist atmosphere and thus the desiccation be easily prevented for a long time. From time to time small pieces of the jelly as large as a pea can be taken and tested for the progress of nitrification. _Results._—The nitrous reaction, both in the prepared jelly and in sterilized soil, will appear in a few days. At the end of from seven to twelve days it will have attained its maximum intensity and will then remain stationary indefinitely. Sterilized soil has no power to generate the nitric from the nitrous ferment. The two organisms are, therefore, of different species. After a few generations the power of producing nitrates seems to be lost although the nitrous ferment may still be active. This suppression of the power to oxidize the nitrites is not due to any pernicious influence of the culture-medium but to the condition of the successive solutions at the time of taking the seeding samples. =436. Microscopic Examination.=—A small particle of the deposit in the culture-liquid is spread on a glass slide and dried. There is then added a drop of very dilute perfectly transparent malachite green solution. Malachite green is Bittermandelölgrün, or tetramethyldiamidotriphenylcarbinol. Use the zinc chlorid double salt or oxalate. In about half a minute it is washed and colored by a very dilute solution of gentian violet which is left to act for some time. The cells then appear distinctly colored on a colorless background. In examining in this way nitrous cultures under a moderate enlargement there are seen particles of material covered with scattered groups and massive zoöglœæ composed of cells which are, doubtless, identical. By their round or roundish forms, by their relative size and especially by their numbers and uniformity they are at once distinguished from the other vegetations which are generally of a purely bacillus shape. With the exception of some shreds of mycelium coming from some oidium in the soil the microscope reveals nothing but the organisms described. The microscopic appearance[288] of the nitrous ferment is shown in Fig. 69. Figure 69. (Upper figure.) Nitrous ferment prepared by Winogradsky from soil from Cito. Figure 70. (Lower figure.) Nitric ferment prepared by Winogradsky from soil from Cito. ] The general conclusions of Winogradsky are: 1. Each soil possesses but one organism capable of oxidizing ammonia. 2. Soils from one locality have always the same kind of nitrifying ferment. 3. Soils from different and distant countries contain nitrifying organisms which differ from one another in some respects so much so that it may be necessary to distinguish a few species or even genera in these bodies. =437. Isolation of the Nitric Ferment in Soils.=—The principle of the separation of this ferment as described by Winogradsky rests upon the fact that in culture solutions of a mineral nature free from ammonia the nitrous ferment will not grow, whereas if nitrite or nitrous acid be present the nitric ferment will grow.[289] In a few generations, therefore, the nitrous ferment will be entirely eliminated. Solution employed: Distilled water 1,000 grams. Potassium phosphate 1 gram. Magnesium sulfate 0.5 „ Calcium chlorid trace. Potassium nitrite 0.22 gram. To culture-flasks containing 100 cubic centimeters of the above mixture after sterilization about one-tenth gram of fresh soil is added. In favorable conditions the nitrous acid will disappear in about fifteen days. Subcultures are made by seeding fresh portions of the sterilized solution with one or two cubic centimeters of the mother culture. The operation is continued until the nitrous ferment is eliminated. The organisms in the deposit in the culture-flasks are then subjected to microscopic examination in the manner already described for the nitrous ferment; or proceed as follows: =438. Culture on Solid Media.=—Take a liquid which has been employed in the culture of a nitrous ferment and evaporate to one third of its bulk. Gelatinize the residue by adding double its volume of the silicic acid solution prepared as already directed. The jelly is placed in the glass vessels usually employed. The seeding may be done with a few drops of a culture-liquid containing the nitric ferment as obtained above. The first reaction will appear in from eight to ten days. In about forty-five days the nitrous acid in the jelly will have entirely disappeared. Two classes of colonies are noticed under the microscope. The first to appear are small colonies which never extend beneath the surface of the jelly. In cultures seeded with these colonies there is no oxidation of nitrous acid. The second class of colonies extends into the interior of the jelly. They are much larger than the first, of a yellowish-gray color and not spherical but rather lenticular in shape. Cultures seeded with these colonies will lose their nitrous acid in about ten days or two weeks. The growth of these organisms in a liquid scarcely merit the name of cultures. The naked eye can usually distinguish no form of vegetation. The liquid remains clear, the surface is free from any film, no flocks are deposited. Colored and examined in the microscope the organisms found are so puny as to make doubtful their oxidizing power. There is an apparent contradiction between the powerful chemical action that these organisms can produce and their apparent deficiency in physical properties. These organisms are best found by cultivating them in a very limpid solution. The bottoms of the culture boxes will be found covered with an extremely tenuous gelatinous deposit communicating to the glass a feeble grayish-blue tint. The culture bottle is inclined and the bottom scratched with a recently drawn-out capillary tube. The colonies rise in the tube together with a little of the liquid. The colonies are dried, mounted, and colored as already described and when examined with the microscope are found to be composed exclusively of masses of an organism of extreme minuteness. The organism remains attached so firmly to the bottom of the culture bottle that it can be washed several times with pure water without danger of detachment and thus rendered more pure. In old cultures which are sustained by new additions of nitrite an extremely transparent pellicle on the bottom of the flask can be distinguished. By shaking the liquid some fragments may be detached and made to float through the fluid. With a little care and patience these flocks can be captured, mounted, and colored. Since they show the nitric organism in its natural state their preparations are of the greatest interest. The best preparations are made by coloring with malachite green and gentian violet and then coloring again hot with magenta. Afterwards the preparation is washed with warm water at 50°–60° which takes almost the whole of the color from the gelatinous matter. The cells are then clearly presented colored a reddish violet on a rose background. These organisms[290] are shown in figure 70. The figure shows the cells united by a gelatinous membrane and grouped in small dense masses composed often of a single layer of organisms. The cells are generally elongated, rarely regularly spherical or oval. Their mean length does not exceed half a micromillimeter and their thickness is from two to three times less. The difference in form of the nitrous and nitric ferments is very marked and leaves no doubt of the existence of these two forms which are as distinct as could be desired in microbic discrimination. =439. Dilution Method of Warington.=—The method pursued by Warington in preparing pure cultures of the nitrifying ferment is based on the well-known principle of dilution which may be expressed as follows:[291] In a liquid containing bacterial ferments dilution may be practiced until a drop of the liquid may be taken which will contain no more than a single organism of any one kind. If now proper solutions be seeded with single drops of this solution, some of them may give colonies of pure cultures of any given organism. The solution to be nitrified employed by Warington had the following composition: Water 1000 parts. Ammonium carbonate 0.25 „ Ammonium chlorid 0.50 „ Potassium phosphate 0.04 „ Magnesium sulphate 0.02 „ Calcium sulphate 0.02 „ The ammonium chlorid is added to prevent the precipitation of magnesium and calcium phosphates. The solution is kept in wide-mouthed, stoppered bottles to prevent the loss of ammonium carbonate, the bottles being only half full. About 100 cubic centimeters are taken for each experiment. These bottles are sterilized and seeded with fresh soil in the ordinary way. They are then covered with paper caps and placed in a dark cupboard at a constant temperature of 22°. _Special Media._—A quantity of arable soil is exhausted of nitrates by washing with cold water under pressure. The soil is then boiled with water and filtered. The clear amber-colored solution obtained may be used instead of water in the above formula. _Solid Media._—(1) Ordinary ten per cent gelatin made with beef broth and peptone. (P) (2) A ten per cent urine solution solidified with six per cent of gelatin. (U) (3) A solution of one gram of asparagin, one-half gram sodium acetate, one-half gram potassium phosphate, two-tenths gram magnesium sulfate, two-tenths gram calcium sulfate, and one liter of water solidified with six per cent gelatin. (As) Other solid media may also be employed for the purpose of favoring, as much as possible, the growth of the nitrifying organisms. The first culture in the ammonium carbonate solution given above, is always made by seeding with a little unmanured arable soil. Subcultures are seeded from this mother culture by seeding new solutions with a few drops of the original. In all cases tried by Warington the subcultures produced only nitrous fermentation while the original cultures produced the nitric fermentation. =440. Microscopic Examination.=—The microscopic examination of the organisms formed is conducted as follows: The cover glasses for microscopic objects are placed at the bottom of the culture-flask, the cover glasses being previously sterilized. At the end of the nitrification the liquid is removed with a pipette and the flask containing the cover glasses dried at 35°. The cover glasses are then removed and stained. The microscopic appearance of the organisms obtained by the previous cultures showed masses of corpuscles usually of oval shape and having a length generally exceeding one micromillimeter. An immersion objective giving a magnification of 800 diameters is suitable for this work. Other forms of organisms are also met, the whole series being characterized as follows: (1) The corpuscles already mentioned. Larger ones are frequently rough in outline resembling masses of siliceous sea-sand. The smaller oval corpuscles are regular in form. (2) Some very small circular organisms often appearing as mere points and staining much more plainly than the preceding. (3) A few slender bacilli, staining faintly. All the cultures obtained by the above method give abundant growth on gelatin. =441. Trials with the Dilution Method.=—One part of the third subculture in the ammonium carbonate solution described above, is mixed with 500 parts of thoroughly boiled water and one drop from a sterilized capillary tube is added to each of five bottles containing the sterilized ammonium carbonate solution. In Warington’s experiments one of the five bottles was found to have nitrified after forty-one days. After ninety-one days two more were nitrified. Two bottles did not nitrify at all. All three solutions which nitrified gave growths on gelatin. The growths took place more speedily on gelatin U and As than on P. The organisms obtained on gelatin were seeded in appropriate liquid media but no nitrification was obtained. A subculture from solution No. 2 of the first dilution mentioned above, was diluted to one one-thousandth, one ten-thousandth, one one-hundred-thousandth, and one one-millionth. Each of these dilutions was used for seeding with five sterilized solutions of ammonium carbonate, using the method of seeding above described. At the end of 190 days not one of these solutions had nitrified. Warington supposed that the cause of failure in the method just mentioned might be due to the alkalinity of the ammonium carbonate. While this solution could be seeded in the ordinary way with fresh earth it might be that the faint alkalinity which it presented might prevent it altogether from action when the nitrifying agent was reduced to a few organisms. He therefore changed the solution to one of the following composition: Water 1,000 parts. Ammonium chlorid 0.02 part. Potassium phosphate 0.06 „ Magnesium sulfate 0.03 „ Calcium sulfate 0.03 „ The solution was divided in twenty stoppered bottles which were half filled. The bottles were divided into four series, A, B, C, D, each one consisting of five bottles, and these were respectively seeded with one drop from dilutions to one one-thousandth, one ten-thousandth, one one-hundred-thousandth, and one one-millionth of a second subculture of No. 3 in the first dilution series. After 115 days, nitrification had occurred in ten of the bottles. The other ten did not nitrify at all. Each of the nitrifying solutions was spread on gelatin, P and U being employed. Growth took place far more easily on gelatin U than on gelatin P. Of the ten nitrified solutions there were three which gave no growth on gelatin U, either when spread on the surface or introduced into the substance of the jelly. There were therefore secured nitrifying solutions which did not contain organisms capable of growing on gelatin. The supposition is therefore fair that they were pure nitrifying organisms. These fresh, pure organisms had the faculty of converting ammonia into nitrous acid only and not into nitric acid. With the organisms thus prepared a number of solutions of potassium nitrite containing phosphates and other mineral ingredients were seeded. In no case was any loss of nitrite found, which is proof that the solution contained no organisms capable of oxidizing nitrous acid. The organisms prepared as above, have the power of nitrifying organic substances containing nitrogenous bodies. The organism isolated as described and examined under the microscope is seen to contain two forms. The first one is nearly spherical in shape, the corpuscles varying in size from mere points to a diameter of one micromillimeter. The form is very striking and easily stained. The second form is oval-shaped and attains a length distinctly exceeding one micromillimeter. Sometimes it is a regular oval and sometimes it is egg-shaped. This form is stained less easily than the preceding or spherical form. =442. Method of Staining.=—The method of staining employed is as follows: A drop of the culture-liquid is placed on a glass slide and mixed with the filtered stain by means of a wire. A cover glass is placed on the drop and allowed to stand for half an hour. It is then pressed down on the slide and the liquid which exudes wiped off and hollis glue run around the cover glass. In this way the organism is stained in its own culture-fluid and can be seen in its true form without any possibility of the destruction of its shape by drying. The plate is bright and clear though colored. If the preparation is to be mounted in balsam a drop of the culture is dried in the center of a cover glass. It is then placed for some minutes in dilute acetic acid to remove matter which would cause turbidity. The cover glass with its contents is then washed, dried, and stained for some hours in methyl violet. =443. Classification of Nitrifying Organisms.=—The names proposed by Winogradsky for the various organisms are the following: For the general group of microbes transforming ammonia into nitric acid, _Nitro-bacteria_. For the nitrous ferments of the Old World Genus, _Nitrosomonas_: Species, _Nitrosomonas europaea_. _Nitrosomonas javanensis._ For the nitrous microbes of the New World: Genus, _Nitrosococcus_. Species, not determined. For the nitric ferment: Genus, _Nitrobacter_. =444. Nitrification in Sterilized Soil.=—The process of nitrification in sterilized soil, when seeded with pure cultures, is determined as follows: _Preparation of Sample._—The fresh sample of arable soil is freed from pebbles and vegetable débris and reduced to as fine a state of subdivision as is possible in the fresh state. It is placed in quantities of about 800 grams in large crystallizing dishes. One dish is set aside for use in the natural state, and the other, hermetically closed, is placed in a sterilizing apparatus and subjected to the action of steam for two and a half hours. This treatment is repeated three times on as many successive days. _Seeding of Sample._—Each of the two dishes is moistened with fifty cubic centimeters of pure water containing 500 milligrams of ammonium sulfate. The sterilized portion is then seeded with a preparation of the pure nitrous ferment, produced as before described. The seed is prepared by filtering a few cubic centimeters of the nitrous culture liquid through asbestos. The asbestos is well washed and then thrown into a flask containing a few cubic centimeters of sterilized water and well shaken. The water carrying the filaments of asbestos is poured drop by drop on the surface of the soil in as many places as possible. The two dishes of soil are kept at an even temperature of 20° in a dark place. Winogradsky found that, treated in this way, the unsterilized soil produced only nitrates, while the sterilized portions produced only nitrites.[292] =445. Variation of the Determinations.=—To vary the conditions of the experiment Winogradsky uses twelve flasks of the erlenmeyer shape, four having bottoms twelve centimeters in diameter, and eight of them five centimeters in diameter. In each of the four large flasks are placed 100 grams of fresh soil, and in each of the eight small flasks twenty-five grams. The eight small flasks are designated a, b, c, d, and a′, b′, c′, d′, and the four large flasks A, B, C, D. The flasks a, b, c, d, and a′, b′, c′, d′, are placed in a stove at 30° for several days before use, while A, B, C, and D, are kept at 22°–23° for the same length of time. The soil in the small flasks is, therefore, somewhat drier than that in the large ones. The flasks are treated as follows: a, a′, A, contain the soil as prepared above for control. b, b′, B, are sterilized at 135° and seeded with a drop of the pure nitrous culture. c, c′, C, sterilized as above and seeded with a little of the unsterilized earth. d, d′, D, sterilized as above and seeded with pure nitrous and pure nitric cultures. After sterilization there was added to the small flasks two cubic centimeters of a twenty per cent sterilized ammonium sulfate solution, and to the large ones six cubic centimeters. At the end of a month or six weeks the contents of the flasks are thrown on a filter and washed with cold water until a drop of the filtrate gives no blue color with diphenylamin. The respective quantities of nitrite and nitrate are then determined in the filtrates by the usual processes, which will be fully described further along. =446. Sterilization.=—One of the chief requisites for success in the bacteriological investigation of soils is found in the thoroughness of the sterilizing processes. The value of cultures depends chiefly on the care with which the introduction of foreign germs is prevented. In the following description a mere outline of the method of sterilization is presented, while those who wish to study more carefully the details of the process are referred to the standard works on bacteriology. =447. Sterilization of the Hands.=—It is important that the hands of the operator handling apparatus and materials for bacteriological work should be sterilized. The sterilization may be accomplished in the following way: The nails should be cut short and thoroughly cleaned with soap and brush. The hands are thoroughly washed in hot water with soap. After washing in hot water the hands should be washed in alcohol and ether. They are then dipped in the sterilizing solution. This liquid may consist of a three per cent solution of carbolic acid, which is the one most commonly employed. A solution of corrosive sublimate, however, is perhaps the best disinfectant. It should contain from one to two parts of the crystallized salt to 1,000 parts of water. It has lately been advised to use the sublimate in an acid solution. Acetic acid or citric acid may be employed, but hydrochloric acid is recommended as the best, in a preparation of one-half part per 1,000. For stronger solutions of sublimate containing more than a half per cent, equal quantities of common salt should be added. The solution should be made with sterilized water. After dipping the hands in the sterilizing solution they should be dried with a napkin taken directly from a sterilizing oven, where it has been kept for some time at the temperature of boiling water. Where only ordinary work in bacteriology is contemplated this sterilization of the hands is not necessary. It is practiced chiefly in antiseptic surgery. =448. Sterilizing Apparatus.=—With platinum instruments the most effective and easiest way for sterilizing is to hold them in the flame of a bunsen until they are red hot. Steel and copper instruments can not be treated in this way without injury. They are best sterilized by submitting them to dry heat in a drying oven at a temperature of 150°–160° for two hours. Glass and porcelain apparatus can be sterilized best in the same way. All apparatus and materials employed should be used in a space as free as possible from dust, so that any germs which might be carried in the dust can be excluded from the apparatus in transferring it from one place to another. =449. Methods of Applying Heat.=—Sterilization by means of heat may take place in several ways. _First. Submitting the Materials to Dry Heat Without Pressure._—The temperature in sterilization of this kind may vary from the temperature of boiling water at sea-level to 160° obtained by an oil-bath or by an air-oven. _Second. Sterilization in a Liquid Under Pressure._—This form of sterilization may be effected by sealing the liquid in a strong vessel and submitting it to the required temperature. If the temperature required be greater than that of boiling water the vessel can be immersed in a solution of some mineral salt which will raise the boiling-point. _Third. Sterilization in Steam Under Pressure._—This method of sterilization consists in placing the body in a proper receptacle in vessels to which the steam can have access and then admitting steam from a boiler at any required pressure. In the case of small apparatus, such as the autoclave, the steam can be generated in the apparatus itself. The variety of apparatus used in the above method of sterilization is very great, but all the forms of apparatus employed depend upon the principles indicated. =450. The Sterilizing Oven.=—The apparatus for sterilization by means of hot, dry air usually consists of a double-walled vessel made of sheet-iron, usually with a copper bottom. The apparatus is shown in Fig. 71. The temperature is controlled by means of a thermometer, T, and the gas-regulator, _R_. This is one of the ordinary gas-regulators by means of which the amount of gas supplied to the lamp is increased if the temperature should fall, and diminished if it should rise above the required degree. The best form of the sterilizing ovens is provided with a means for circulating the hot air so that the temperature may be made uniform throughout the mass. This can be accomplished by introducing a mechanical stirrer, or by the movement of the air itself. FIGURE 71. STERILIZING OVEN. ] Between the walls of the vessel may be placed water, provided the temperature of sterilization be that of boiling water. If it should require a higher temperature than boiling water, a solution of salt can be added until the required temperature is reached, or the space between the two walls may be left vacant and hot air made to circulate around the oven. The exterior of the oven, except at the bottom where the lamp strikes the copper surface, should be protected by thick layers of asbestos or other non-conducting material. To avoid danger of flying filaments, this covering should be coated with some smooth paint which will leave an even surface not easily abraded. =451. Sterilization with Steam at High Pressure.=—The apparatus used for this is commonly called an autoclave and is shown in Fig. 72. The top is movable and held in place by the clamp, _a_, which is fixed by the screw worked by the lever, _b_. The vessel itself is double-jacketed and the pressure is obtained from water in the vessel heated by means of the lamp, _c_. The actual steam pressure is indicated by the index _d_. The safety-valve, _e_, allows any excess of steam to escape above the amount required for the maintenance of the pressure. This, however, is best regulated by the lamp. The outer jacket permits the heat from the lamp to circulate around the inner pressure vessel, and the holes near the top, _oo_, are for the escape of the heated gases. Enough water is placed in the bottom of the inner pressure vessel to supply all the aqueous vapor necessary to produce the required pressure and still leave some water in excess. FIGURE 72. AUTOCLAVE STERILIZER. ] The materials to be sterilized are held on the shelves of the stand and the vessels may be of various kinds according to the nature of the material to be sterilized. The vessels containing the material being covered, the steam does not come in actual contact with it. At the end of the operation the safety-valve must not be opened to allow the escape of the steam, otherwise the remaining water would be rapidly converted into vapor and would be projected over the materials on the shelves. The lamp should be extinguished and the apparatus allowed to cool. The autoclave is not only useful for sterilizing purposes but can be made of general use in the laboratory where heat under pressure, as in the estimation of starch, etc., is required. These two forms of apparatus are sufficient to illustrate the general principles of sterilization by hot air and steam. There are, however, many variations of these forms designed for special use in certain kinds of work. For full descriptions of these, reference is made to catalogues of bacteriological apparatus. =452. Arnold’s Sterilizing Apparatus.=—A very simple and cheap steam sterilizer has been devised by Arnold. FIGURE 73. ARNOLD’S STERILIZER. ] Water is poured into the pan or reservoir, B, Fig. 73, whence it passes through three small apertures into the shallow copper vessel, A. It is there converted into steam by being heated with any convenient lamp, and rises through the funnel in the center to the sterilizing chamber. Here it accumulates under moderate pressure at a temperature of 100°. The excess of steam escapes about the cover, becomes imprisoned under the hood, E, and serves to form a steam-jacket between the wall of the sterilizing chamber and the hood. As the steam is forced down from above and meets the air it condenses and drips back into the reservoir. Such an apparatus as this is better suited to commercial purposes, as the sterilizing of milk, than for scientific uses. =453. Thermostats for Culture Apparatus.=—It is important in the culture of micro-organisms that the temperature should be kept constant during the entire time of growth. Inasmuch as some operations continue for as much as three months it is necessary to have special forms of apparatus by means of which a given temperature, during the time specified, can be maintained. This is secured by means of an oven with an automatic temperature regulator, practically built on the principle of the hot air sterilizing oven already described. The essential principles of construction are, however, that the regulator for the temperature should be delicate and that the non-conducting medium surrounding the apparatus should be as perfect as possible, so that the variations in temperature from changes in the exterior temperature, are reduced to a minimum. This delicacy is secured by introducing a drop of chloroform-ether into a confined space over the mercury of the regulating apparatus. The doors of the chamber are double, the interior one being of glass so that the exterior door can be opened for inspection of the progress of the bacterial growth without materially interfering with the interior temperature. A convenient form is shown in Fig. 74. FIGURE 74. LAUTENSCHLÄGER’S THERMOSTAT. ] The apparatus figured, is oval in shape, although circular or other forms are equally as effective. The arrangement of the lamp, _a_, thermometers, _t t t_, and gas-regulator, _g_, and the double doors, _d d_, is shown in the engraving and does not require further description. The usual temperatures for cultures range from 22° to 35°, and the apparatus once set at any temperature will remain fixed with extremely minute variations for an indefinite time. The apparatus possesses a heat zone which, by the arrangement of the regulator, is kept absolutely constant. The space between the walls of the apparatus being filled with water, the temperature is maintained even in every part. The apparatus, as constructed, is independent not only of the surrounding temperature within ordinary variations, but also of the pressure of the barometer. Three thermometers are employed to determine the temperature of the heating zone, the water space and the inner space. The arrangement of the gas-regulator is of an especial kind, as mentioned above, by means of which the consumption of gas is reduced to a minimum. This apparatus can be regulated to suit the character of the work. =454. Microscopic Apparatus Required.=—Any good microscope, capable of accurate observation, of high power, may be used for the bacteriological observations necessary to soil analysis. Preference should be given to the patterns adapted to receive any additional accessories which may be subsequently required for advanced work. The stage, in addition to being fitted with a sliding bar, should have a large circular or horseshoe opening to facilitate focusing operations. A mechanical stage is a desirable acquisition if really well made, but a plain stage is preferable for many purposes. A rackwork, centering sub-stage is essential for advanced work, and in the absence of the more complete form, there should at least be a fitting beneath the stage to take the diaphragm and condenser. An iris diaphragm will be found more useful than any other kind in practice, since the size of the opening can be increased very gradually at will. One of the best lamps is known as the paraffin lamp and is fitted with a half-inch wick. This will give even more light than is actually required, and a steady flame, perfectly under control, may be obtained. For the minute details to be observed in high-grade microscopic work, such as is required in the bacteriological examination of soils, reference must be had to the standard works on bacteriology and microscopy. =455. General Conclusions.=—The nitrogenous food of plants is provided in several ways; _viz._, (1) By the nitrogen brought to soil in rain and snow. This nitrogen is chiefly in the form of ammonia and nitric acid. The nitrogen gas in solution in rain water has no significance as a plant food. (2) By the action of certain anaerobic organisms herding in the rootlets of leguminous plants, free nitrogen may be oxidized and put into form for assimilation. (3) By the action of certain organisms on nitrogenous compounds pre-existing in the soil, ammonia, nitrous acid, and finally, nitric acid, are produced. It is believed that the plant organism, unaided by the activity of a micro-organism, is unable to assimilate nitrogen unless it be fully oxidized to nitric acid. (4) There exist micro-organisms capable of acting directly on free nitrogen independent of other plant growth, but the significance of this possible source of plant food is, at the present time, unknown. (5) The micro-organisms of importance to agriculture may be isolated and developed to the exclusion of other organisms of a similar character. This isolation is best accomplished in culture-media consisting essentially of a mineral gelatin to which is added only pure carbohydrates and the necessary mineral nourishment. (6) The nitrifying ferments consist probably of several species, of different geographic distribution. Different types of soils probably have nitrifying organisms of different properties. This is illustrated by the fact that nitrification is accomplished in dry alkaline soils under conditions in which the ordinary nitrifying organisms would fail to develop. (7) The study of typical soils in respect of the kind, activity, and vigor of their nitrifying organisms has become as important a factor in soil analysis as the usual determination of physical and chemical composition. DETERMINATION OF NITRIC AND NITROUS ACIDS IN SOILS. =456. Classification of Methods.=—The minute quantities in which highly oxidized nitrogen exists in soils render the operations of its quantitative estimation extremely delicate. On the other hand, the easy solubility of these forms of combination and the absence of absorptive powers therefor, in the soil, render the separation of them from the soil a matter of great ease. It is possible, therefore, to secure all the nitrates and nitrites present in a large quantity of earth in a solution which can be concentrated under proper precautions to a volume convenient for manipulation. The method of this extraction is the same for all the processes of determination. The methods of analysis suited to soil extracts, as a rule, may also be used in the determination of the same compounds in rain, drainage, and sewage waters, and for the qualitative and quantitative control of the progress of nitrification. The various processes employed may be classified as follows: 1. The conversion of the nitrogen into the gaseous state and the determination of its volume directly. This is accomplished by combustion with copper oxid and metallic copper. 2. The conversion of the nitrogen into nitric oxid and the volumetric determination thereof. The decomposition of a nitrate with ferrous chlorid in the presence of free hydrochloric acid is an instance of this type of methods. 3. The oxidation of colored organic solutions and the consequent disappearance of the characteristic color, or its change into a different tint. The indigo and indigotin processes are examples of this method. 4. The production of color, in a colorless or practically colorless solution, by the treatment thereof with the nitrate in presence of an acid which decomposes it with the liberation of oxidizing compounds. The depth of color produced is compared with that formed by a known quantity of a pure nitrate solution until the two colorations are alike. The methods depending on the use of carbazol or acid phenol sulfate illustrate this class of reactions. 5. The conversion of the nitrogen into ammonia by moist combustion with sulfuric acid in the presence of certain organic compounds, _e. g._, salicylic acid, and the collection of the ammonia in standard acid, the excess of which, is determined by titration. 6. The reduction of nitrates to ammonia by nascent hydrogen and the recovery of the ammonia produced by distillation and collection in standard acid. 7. The reduction of nitrates by electrolytic action and the collection of the ammonia as above. 8. The decomposition of nitrates with the quantitative evolution of a different element, and the direct or indirect measurement of the evolved substance. The quantitative evolution of chlorin on treating a nitrate with hydrochloric acid, the collection of the chlorin in potassium iodid, and the determination of the iodin set free, form a process belonging here. =457. Relative Merit of Methods.=—The processes mentioned in the classifications embraced under numbers (1) and (5) of the preceding schedule are sufficiently described in the paragraphs devoted thereto, under soil and fertilizers. In practice at the present time it is rare to determine the nitrogen in nitrates by the copper oxid method. The more rapid and equally exact processes of colorimetric comparison or reduction by nascent hydrogen are in all respects to be preferred. The indigo methods among the colorimetric processes are not so much in use now as those which depend on the development of a color. Lawes and Gilbert considered them far inferior to the Schloesing method. The developed color methods are especially delicate and are to be preferred in all cases where the detection of the merest traces of nitrates is desired. Where nitrates are present in considerable quantities the reduction method with nascent hydrogen is to be preferred over all others. In all these cases the judgment of the analyst must be exercised. The particular method to be employed in any given case can not be determined save by the intelligent discrimination of the operator. =458. The Extraction of Nitric Acid from the Soil.=—The easy solubility of nitric acid and of nitrates in water is taken advantage of in the separation of these bodies from the soil. A convenient quantity, usually about 1,000 grams of the fine soil, is taken for the extraction. Instead of freeing the soil entirely from water, it is better to determine the amount of water in the air-dried or prepared sample, and base the calculation on 1,000 grams of the water-free soil. All samples of soil, when taken for the purpose of examining for nitrates, should be rapidly dried to prevent the process of nitrification from continuing after the sample is taken. For this purpose the soil should be placed in a thin layer in a warm place, 50°–60°, until air-dried. It still contains in this case a little moisture but not enough to permit nitrification to go on. One thousand grams of soil prepared as above are treated with 2,000 cubic centimeters of distilled water, free of nitric acid, and allowed to stand for forty-eight hours with frequent shaking. One thousand cubic centimeters of the extract are then filtered, corresponding to 500 grams of the dry soil. A small quantity of pure sodium carbonate should be added to the filtrate which is then evaporated on a water-bath to a volume of about 100 cubic centimeters. Should a precipitate be formed during evaporation it should be separated by filtration, the filter washed thoroughly, and the filtrate again evaporated to a volume of 100 cubic centimeters. In taking a soil for the determination of nitrates, it is well to extend the sampling to a considerable depth. If the sample be taken only to the depth of nine inches, it should be in dry weather when the nitrates are near the surface. The temperature at which a soil is dried has also an influence on the quality of nitric nitrogen remaining after desiccation. If a wet soil be dried at 100°, the nitrates present will suffer partial decomposition. This is probably due to deoxidation by organic matter present. On the other hand, ordinary air-drying affords opportunity for continued nitrification, thus increasing the residuum of oxidized nitrogen. The above method is essentially that followed by Warington at Rothamstead. The method of drying practiced at Rothamstead, in order to secure results as nearly accurate as possible is the following:[293] The soil is broken up directly after it is taken from the field, and spread on trays in layers one inch deep. The trays are then placed in a room at 55°. The drying is completed in twenty-four hours. After drying, stones and roots are removed, and the soil is finely powdered and placed in bottles. For extracting the nitrates, a funnel is prepared by cutting off the bottom from a bottle four and a half inches in diameter. A nicely fitting disk of copper gauze is placed in the bottom of this funnel, and this is covered with two filter papers, the upper one having a slightly greater diameter than the lower. The paper is first moistened, and then from 200 to 500 grams of the dry powdered soil introduced. The funnel is connected with the receiving flask of a filter pump, and pure water poured on the soil until it is thoroughly saturated. The water is then added in small quantities. When the filtrate amounts to 100 cubic centimeters the process may be discontinued, since all the nitrates in the soil will be found in this part of the filtrate. The extract obtained above is evaporated to convenient bulk for the determination of nitric nitrogen. THE NITRIC OXID PROCESS. =459. Method of Schloesing.=—The processes for estimating nitrogen by combustion with copper oxid and by moist combustion with sulfuric acid have both been used for the determination of the quantity of nitrogen existing in a highly oxidized state. These processes will be fully discussed under the head of fertilizers. In the case of soil extracts, drainage waters, etc., it will be sufficient to discuss, for the present, only those processes adapted especially to a quick and accurate estimation of oxidized nitrogen. The principle of the method of Schloesing depends on the decomposition of nitrates in the presence of a ferrous salt and a strong mineral acid.[294] The nitrogen in the process appears as nitric oxid, the volume of which may be directly measured, or it may be converted into nitric acid and titrated by an alkali. The typical reactions which take place are represented in the following equation: 6FeCl₂ + 2KNO₃ + 8HCl = 3Fe₂Cl₆ + 2KCl + 4H₂O + 2NO. =460. Schloesing’s Modified Method.=—The Schloesing method as now practiced by the French chemists is conducted in the apparatus shown in Fig. 75.[295] The carbon dioxid is generated by the action of the hydrochloric acid in F on the fragments of marble in A. After passing the wash-bottle the gas enters the small tubulated retort, C, which contains the nitrate in solution. For ordinary soils 100 grams are placed in an extraction flask, plugged with cotton, and a layer of the same material is placed over the soil for the purpose of securing an even distribution of the extracting liquid. This liquid is distilled water containing in each liter one gram of calcium chlorid. The purpose of using the calcium chlorid is to prevent the soil from becoming compacted which would render the extraction of the nitrate difficult. The extracting liquid is allowed to fall drop by drop from a mariotte bottle until the filtrate amounts to 500 cubic centimeters. This volume is concentrated on a sand-bath until it is reduced to ten or fifteen cubic centimeters when it is transferred to a flat-bottomed dish and the evaporation finished over steam, care being taken not to allow the temperature to exceed 100°. FIGURE 75. SCHLOESING’S APPARATUS FOR NITRIC ACID. ] Another and more rapid method for dissolving the nitrate, may also be practiced. In a flask holding about one liter, place 220 grams of the soil and 660 cubic centimeters of distilled water and shake vigorously, or enough water to make 660 cubic centimeters together with the moisture remaining in the air-dried sample taken. All the nitrates pass into solution. Throw the contents of the flask into a filter and take 600 cubic centimeters of the filtrate which will contain all the nitrates in 200 grams of the sample taken. This filtrate is evaporated as described above. In the flat dish containing the dried nitrates, pour three or four cubic centimeters of ferrous chlorid solution and stir with a small glass rod until complete solution of the nitrate takes place. By means of a small funnel the solution is poured into C, and the capsule and funnel are well rinsed with two cubic centimeters of hydrochloric acid. The washing is repeated three times as above described, and once with one cubic centimeter of water, which is added cautiously so as to form a layer over the surface of the heavier liquid. The tubulated flask is then connected with the carbon dioxid apparatus, previously freed from air, and the gas allowed to flow evenly until the whole of the apparatus is completely air-free. The other details of the method are essentially the same as those adopted by the Commission of French Agricultural Chemists which will be given below. =461. The French Agricultural Method.=—The Schloesing method as practiced by the French agricultural chemists is very slightly different from the procedure just described.[296] The process with soils is carried on as follows: Five hundred grams of the soil are taken and introduced into a flask of about two liters capacity and shaken thoroughly with a liter of distilled water. The whole of the nitrates of the soil is thus passed into solution. The solution is filtered and 400 cubic centimeters of the filtrate are taken, which correspond to 200 grams of the soil. This liquid is evaporated in a flask, adding a fragment of paraffin to prevent foaming, until its volume is reduced to fifteen or twenty cubic centimeters. It is afterwards transferred through a filter into a capsule with a flat bottom in which the evaporation is finished on a steam-bath, taking care that the temperature does not exceed 100°. An important precaution is, not to allow the contact of the water with the soil to be too prolonged, to avoid the reduction of the nitrates which could take place under the influence of the denitrifying organisms which are developed with so great a rapidity in moist earth. The apparatus in which the transformation of the nitrates into nitric oxid takes place is essentially that already described (Fig. 75). The carbon dioxid generator is connected by means of a rubber tube and a small wash-bottle to the small retort in which the reaction takes place, and from which the exit tube leads to a mercury trough. The gas which is disengaged is received under a jar drawn out to a fine point in its upper part, which carries about fifteen cubic centimeters of potash solution containing two parts of water to one of potash. The operation is conducted as follows: Into the small capsule which contains the dried matter, three or four cubic centimeters of ferrous chlorid are poured. By means of a stirring rod the residue sticking to the sides of the capsule is detached with care and all the matter is thus collected in the bottom. By means of a small funnel the contents of the capsule are introduced into the retort. About two cubic centimeters of hydrochloric acid are used for washing out the materials and this acid is also introduced into the retort. The washing with hydrochloric acid is repeated three or four times, and finally the apparatus is washed with one cubic centimeter of water, which is also poured in by the small funnel with great care, so that this water may form a layer over the surface of the liquid. The apparatus is now connected and filled completely with carbon dioxid. Since it is necessary that this gas should be completely free of air, the flask, which generates it, is first filled with the acidulated water from the acid flask, and the air is thus almost totally displaced by the liquid. The evolution of carbon dioxid gas which follows, completely frees the apparatus from air. When this is accomplished the retort is connected with the rest of the apparatus and the gas allowed to pass for about two minutes until the air is completely driven out of all the connections. The current is arrested for a moment by pinching the rubber tube which conducts the carbon dioxid into the retort, and the vessel which is to receive the gas is then placed over the delivery-tube, this vessel being filled with mercury and a strong solution of potash. The communication between the retort and the carbon dioxid flask is broken and the flask is heated slightly by means of a small lamp. The first bubbles of gas evolved should be entirely absorbed by the potash. This will be an indication of the complete absence of the air. When the liquid is in a state of ebullition the nitrogen dioxid is set free. The boiling is regulated in such a way that the evolution is regular and the liquid of the retort may not, by a too violent boiling, pass into the receiver. The boiling is continued until the larger part of the liquid is distilled and only three or four cubic centimeters remain in the retort. At this time a few bubbles of carbon dioxid are allowed to flow through in order to cause to pass into the receiver the last traces of nitric oxid. The gas received is left for some minutes in contact with the potash. Afterward in a small flask, G, the neck of which is drawn out to a fine point, and carrying a bulb-tube, H, and a piece of rubber tubing, there are boiled twenty-five or thirty cubic centimeters of water for five or six minutes in order to drive all the air out of the flask, and while the boiling is continued the rubber tubing is fastened to the drawn-out part of the jar containing the nitric oxid. Within the rubber tubing the drawn-out point is broken and the vapor of water is forced into the jar and drives before it the solution of potash which has filled the capillary part of the drawn-out tube. As soon as the point is broken, the boiling of the flask is stopped and by its cooling the nitric oxid passes into it. It is necessary to press the rubber tubing with the fingers in order that the passage of the gas into the flask be not too rapid. As the solution of potash rises in the bell-jar which contains the nitric oxid near to the point where the rubber tubing covers its drawn-out portion, the fingers are removed and a clamp put in their place. There still remains a little nitric oxid in the flask and to drive this out it is necessary to introduce five or six cubic centimeters of pure hydrogen, which are allowed to pass over into the receiving flask, by releasing the clamp in the same way as the nitric oxid. The hydrogen being introduced in successive portions, finally carries all the nitric oxid into the flask without allowing any of the potash to enter. The flask containing the nitric oxid is now connected with a reservoir of oxygen. The oxygen is allowed to enter, bubble by bubble, by means of cooling the flask by immersion in water. The transformation of nitric oxid into nitric acid is not entirely complete for twenty-four hours. It is necessary, therefore, to wait that long after the introduction of the oxygen before determining the amount of nitric acid produced. The contents of the flask are placed in a titration-jar, the flask being washed two or three times and a few drops of tincture of litmus being added. The nitric acid is then determined by a standard solution of calcium hydroxid or some other standard alkali. From the titration the content of nitric acid is calculated. The French Committee further suggests that this method may be modified in the way of making it more rapid by collecting the nitric acid in a graduated tube filled with mercury and containing some potash. The volume of the gas is determined and the pressure of the barometer and the temperature observed, and the usual calculations made to reduce the volume to zero and to a pressure of 760 millimeters of mercury. Each cubic centimeter of nitric oxid thus measured corresponds to 2.417 milligrams of nitric acid. The presence of organic matter does not interfere with the determination of nitric acid by either of the methods given above. =462. Modification of Warington.=—The method of procedure and description of apparatus used, as employed by Warington, are as follows: The vessel in which the reaction takes place is a small tubulated receiver, A (Fig. 76), about four centimeters in diameter, mounted and connected as shown in the illustration. The delivery-tube dips into a jar of mercury in a trough containing the same liquid. The long supply funnel-tube _a_ is of small bore, holding in all only one-half cubic centimeter. The connecting tube F, carrying a clamp, is also of small diameter and serves to connect the apparatus with a supply of carbon dioxid. FIGURE 76. WARINGTON’S APPARATUS FOR NITRIC ACID. ] In practice, the supply-tube _a_ is first filled with strong hydrochloric acid and carbon dioxid passed through the apparatus until the air is all expelled. This is indicated when a portion of the gas collected over the mercury, is entirely absorbed by caustic alkali. At this point the current of carbon dioxid is stopped by the clamp C, and a bath of calcium chlorid, B, heated to 140° is brought under the bulb A, until the latter is half immersed therein. The temperature of the bath is maintained by a lamp. By allowing a few drops of hydrochloric acid to enter the receiver, the carbon dioxid is almost wholly expelled. The end of the delivery-tube is then connected with the tube, T, filled with mercury, and the apparatus is ready for use. The nitrate, in which the nitric acid is to be determined, in a dry state, is dissolved in two cubic centimeters of the ferrous chlorid solution (one gram of iron in ten cubic centimeters), one cubic centimeter of strong hydrochloric acid is added, and the whole is then introduced into the receiver through the supply-tube, being followed by successive rinsings with hydrochloric acid, each rinsing not exceeding one-half cubic centimeter. The contents of the receiver are, in a few moments, boiled to dryness; a little carbon dioxid is admitted before dryness is reached, and again afterwards to drive over all remains of nitric oxid. In the recovered gas the carbon dioxid is first absorbed by caustic potash, and afterwards the nitric oxid by ferrous chlorid. All measurements of the gas are made in Frankland’s modification of Regnault’s apparatus. The carbon dioxid should be as free as possible from oxygen. The carbon dioxid generator is formed of two vessels, the lower one consisting of a bottle with a tubule in the side near the bottom; this bottle is supported in an inverted position and contains the marble from which the gas is generated. The upper vessel consists of a similar bottle standing upright and containing the hydrochloric acid required to act on the marble. The two vessels are connected by a glass tube passing from the side tubule of the upper vessel to the inverted mouth of the lower vessel. The acid from the upper vessel thus enters below the marble. Carbon dioxid is generated and removed at pleasure by opening a stop-cock attached to the side tubule of the lower vessel thus allowing hydrochloric acid to descend and come in contact with the marble. A good Kipp’s generator of any approved form may also be used instead of the simple apparatus, above described. The fragments of marble used are previously boiled in water in a strong flask. After boiling has proceeded for some time, a rubber stopper is fixed in the neck of the flask and the flame removed. Boiling will then continue for some time in a partial vacuum. The hydrochloric acid is also well boiled and has dissolved in it a moderate quantity of cuprous chlorid. As soon as the acid has been placed in the upper reservoir, it is covered by a layer of oil. The apparatus being thus charged is at once set in active work by opening the stop-cock of the marble reservoir; the acid descends, enters the marble reservoir, and the carbon dioxid produced drives out the air. As the acid reservoir is kept on a higher level than the marble reservoir, the latter is always under internal pressure, and leakage of air from without, into the apparatus, cannot occur. The presence of the cuprous chlorid in the hydrochloric acid not only insures the removal of dissolved oxygen, but affords an indication to the eye of the maintenance of this condition. While the acid remains of an olive tint, oxygen is absent; but should the color change to a blue-green, more cuprous chlorid must be added. All the reagents employed should be previously boiled. In order to secure absolute freedom from air, the following modifications on the above process have been adopted by Warington: The apparatus having been mounted as described, the funnel-tube attached to the bulb retort is filled with water, and the apparatus connected with the carbon dioxid generator. Carbon dioxid is then passed through the apparatus until a moderate stream of bubbles rises in the mercury trough. The stop-cock is left in this position, and the admission of gas is controlled by the pinch-cock. The bath of calcium chlorid is so adjusted as to cause the bulb retort to be almost entirely submerged, and the temperature of the bath is kept at 130° to 140°. Small quantities of water are next admitted into the bulb and expelled as steam in the current of carbon dioxid, the supply of this gas being shut off before the evaporation is entirely completed, so as to leave as little carbon dioxid as possible in the apparatus. Previous to very delicate experiments it is advisable to introduce through the funnel-tube a small quantity of potassium nitrate, ferrous chlorid, and hydrochloric acid, rinsing the tube with the latter reagent. Any trace of oxygen remaining in the apparatus is then consumed by the nitric oxid formed; and after boiling to dryness and driving out the nitric acid with carbon dioxid, the apparatus is in a perfect condition for a quantitative experiment. =463. Preparation of the Materials to be Analyzed.=—According to Warington, soil extracts may be used without other preparation than concentration. Vegetable juices which coagulate when heated, require to be boiled and filtered or else evaporated to a thin sirup, treated with alcohol, and filtered. A clear solution being thus obtained, it is concentrated over a water-bath to a minimum volume in a beaker of small size. As soon as cool, it is mixed with one cubic centimeter of a cold saturated solution of ferrous chlorid and one cubic centimeter of hydrochloric acid, both reagents having been boiled and cooled immediately before use. In mixing with the reagents, care must be taken that bubbles of air are not entangled, which is apt to occur with viscid extracts. The quantity of ferrous chlorid mentioned is amply sufficient for most soil extracts, but it is well to use two cubic centimeters in the first experiment, the presence of a considerable excess of ferrous chlorid in the retort being thus insured. With bulky vegetable extracts more ferrous chlorid should be employed. To the sirup from twenty grams of mangel-wurzel sap, five cubic centimeters of ferrous chlorid and two cubic centimeters of hydrochloric acid are usually added. =464. Measurement of the Gas.=—The measurement of the gas was for some time conducted by the use of concentrated potash for absorbing the carbon dioxid, and ferrous chlorid for absorbing the nitric oxid. The use of the ferrous chlorid, however, was found to introduce a source of error. The treatment of the gas with oxygen and pyrogallol over potash has therefore been substituted by Warington for its absorption by ferrous chlorid. The chief source of error attending the oxygen process lies in the small quantity of carbon monoxid produced during the absorption with pyrogallol; this error becomes negligible if the oxygen be only used in small excess. The amount of oxygen employed can be regulated by the use of Bischof’s gas delivery-tube. This may be made of a test-tube having a small perforation half an inch from the mouth. The tube is partly filled with oxygen over mercury, and its mouth is then closed by a finely perforated stopper made from a piece of wide tube and fitted tightly into the test-tube by means of a covering of rubber. When this tube is inclined, the side perforation being downwards, the oxygen is discharged in small bubbles from the perforated stopper, while mercury enters through the opening. Using this tube, the supply of oxygen is perfectly under control and can be stopped as soon as a fresh bubble ceases to produce a red tinge on entering. Warington concludes his description by stating that in the reaction proposed by Schloesing the analyst has a means of determining a very small quantity of nitric acid with considerable accuracy, even in the presence of organic matter; but to accomplish this, the various simplifications consisting in the omission of the stream of carbon dioxid, and the collection of the gas over caustic soda must be abandoned, and special precautions must be taken to exclude all traces of oxygen from the apparatus. =465. Spiegel’s Modification.=—Spiegel noticed inaccuracies in the results of the ferrous chlorid method of estimating nitric acid when carbon dioxid is used, which sometimes amounted to three per cent of the nitric acid present in the sample. The following suggestions are made by him for the improvement of the process:[297] As regards the use of carbon dioxid in the operation, the first difficulty consists in obtaining it entirely free from air. By the use of small pieces of marble, which, before being placed in the Kipp apparatus, are kept for a long while in boiling water, a product is obtained which, after thirty minutes of moderate evolution, leaves only a trace of unabsorbed gas in contact with potash-lye. The apparatus used is illustrated in Fig. 77. FIGURE 77. SPIEGEL’S APPARATUS FOR NITRIC ACID. ] A is a round flask of about 150 cubic centimeters capacity, furnished with a well-fitting rubber stopper provided with two holes, one for the entrance of the funnel-tube B and the other for the delivery-tube C. The tube B ends about two centimeters above the bottom of A and carries a bulb-shaped funnel at its top capable of holding about fifty cubic centimeters. The gas-tube D is ground into the bulb of B as shown in the figure. After the flask had been filled with the solution to be examined, carbon dioxid is conducted through D and the flask is heated to boiling until the gas which escapes through C no longer contains any air. The measuring tube is brought over the end of the delivery-tube C, in the usual manner, but not shown in the figure. In the funnel of B are placed twenty cubic centimeters of previously prepared and boiled ferrous chlorid solution and this liquid is allowed to flow partly into A by lifting slightly the gas-tube, D. About forty cubic centimeters of concentrated, boiled hydrochloric acid are afterwards added to it in the same way. As soon as the liquid in the flask A is again boiling, the stream of carbon dioxid is shut off and allowed to flow again only towards the end of the operation, when the contents of the flask are reduced almost to dryness. As will be seen from the above directions no unboiled liquids of any kind are to be used as reagents in the apparatus described. If the flask A were made much smaller the efficiency of this apparatus would be increased. It appears to have few, if any, advantages over Warington’s process. =466. Schulze-Tiemann Method.=—The modification of Schulze-Tiemann in the ferrous salt method consists chiefly in the omission of the use of carbon dioxid, and in the simplified form of apparatus, which permits rapid work and gives, also, according to some authorities, very exact and reliable results.[298] The extract, representing 500 grams of the fine soil, is reduced by evaporation to 100 cubic centimeters and placed in a glass flask, _A_ (Fig. 78), of 500 cubic centimeters capacity. The flask is closed with a rubber stopper, carrying two bent glass tubes which pass through it. The tube _a b c_ is drawn out into a point at _a_ and reaches about two centimeters below the surface of the rubber stopper. The tube _e f g_ passes just to the lower surface of the rubber stopper. The two tubes mentioned are connected, by means of rubber tubes and pinch-cocks, with the tubes _d_ and _h_. The pinch-cocks at _c_ and _g_ must be capable of closing the tubes air-tight. The end of the tube _g h_ passes into a crystallizing dish, _B_, and is bent upward to a point passing two to three centimeters into the measuring tube _C_. The point within the tube is covered with a piece of rubber tubing. The measuring tube _C_ is divided into tenths of a cubic centimeter, and together with the crystallizing dish _B_, is filled with a ten per cent solution of boiled soda-lye, which is obtained by dissolving 12.9 parts of sodium hydroxid in 100 parts of water. FIGURE 78. SCHULZE-TIEMANN’S NITRIC ACID APPARATUS. ] The liquid which is to be examined for nitric acid, the pinch-cocks being opened and the tube _g h_ not dipping into the crystallizing dish, is boiled for one hour in order to drive the air out of the flask _A_. The end of the tube _e f g h_ is then brought into the crystallizing dish containing the sodium hydroxid solution so that the steam escaping from the flask _A_, escapes partly through the tube _b c d_, and partly through the tube _f g h_, not allowing, however, the bubbles to enter the measuring tube _C_. To determine whether the air is all expelled, the pinch-cock at _g_ is closed and the soda-lye will thereupon rise to _g_ in case no air interferes. It is best to close the tube at _g_ first with the thumb and finger and then the rise of the soda-lye to that point can be determined by the impulse felt. The tube is then firmly closed by means of the pinch-cock _g_. The rest of the steam is allowed to escape through the tube _a b c d_, and the evaporation is continued until the contents of the flask are evaporated to about ten cubic centimeters. The flask into which the tube _c d_ dips, is filled with freshly boiled water. The lamp is removed from the flask _A_, the pinch-cock is closed, whereupon the tube _c d_ becomes filled with the freshly boiled water. The measuring tube _C_, filled with freshly boiled soda-lye is closed with the thumb and brought into the dish _B_, care being taken that no bubble of air enters. It is placed over the end of the tube _g h_. The pressure of the external air will now flatten the rubber tubes at _c_ and _g_. The flask at the end of _c d_ holding freshly boiled water is then replaced with one filled with a nearly saturated solution of ferrous chlorid containing some hydrochloric acid. The flask containing the ferrous chlorid solution should be graduated so that the amount which is sucked into the flask _A_ can be determined. The pinch-cock _c_ is opened and from fifteen to twenty cubic centimeters of the ferrous chlorid solution allowed to flow into _A_. The end of the tube _c d_ is then placed in another flask containing strong hydrochloric acid, and the latter allowed to flow into the tube in small quantities at a time until all the ferrous chlorid is washed out of the tube _b c d_ into _A_. At the point _b_ there is sometimes formed a little bubble of hydrochloric acid in the state of gas, which by heating the flask _A_ completely disappears. The flask _A_ is next warmed gently until the rubber tubes at the pinch-cocks begin to assume their normal condition. The pinch-cock at _g_ is now replaced by the thumb and finger, and as soon as the pressure within the flask _A_ is somewhat stronger, caused by the nitric oxid gas evolved from the mixture, it is allowed to pass through the tube _e f g h_ and escape into the measuring cylinder _C_. By a manipulation of the finger and thumb at _g_, it is possible to prevent regurgitation of the sodium hydroxid into _A_, and at the same time to relieve the pressure of the nitric oxid in _A_, which would be difficult to do by means of the pinch-cock alone. The boiling of the liquid is continued until there is no longer any increase of the volume of gas in the measuring cylinder _C_. After the end of the operation the tube _g h_ is removed from the dish _B_ and the measuring tube _C_ is closed by means of the thumb while its end is still beneath the surface of the soda-lye, and it is shaken until all traces of any hydrochloric acid, which may have escaped absorption, are removed. It is then placed in a large glass cylinder filled with water at the temperature at which the volume of gas is to be read. After being kept at this constant temperature for about half an hour the volume of the nitric oxid can be read. For this purpose the measuring cylinder _C_ is sunk into the water of the large cylinder until the level of the liquids within and without the tube is the same. The usual correction for pressure of the atmosphere, as determined by the barometer, and for the tension of the aqueous vapor at the temperature at which the reading is made, is applied. The correction is made by means of the following formula: V′ = (V × 273 × (B − f)) ÷ ((273 + t) × 760) In this formula V′ denotes the volume of the gas at the temperature of zero, and at 760 millimeters barometric pressure; V the volume of the gas as read at the barometric pressure observed, B, and the temperature observed, _t_, while _f_ denotes the tension of the aqueous vapor in millimeters of mercury pressure at the observed temperature _t_. The tension of the aqueous vapor at temperatures from zero to 26°, expressed in millimeters of mercury, is given in the following table: ─────┬───────────── Temp.│ Tension in ° │mm. mercury. ─────┼───────────── 0│ 4.6 1│ 4.9 2│ 5.3 3│ 5.7 4│ 6.1 5│ 6.5 6│ 6.9 7│ 7.4 8│ 8.0 9│ 8.5 10│ 9.1 11│ 9.7 12│ 10.4 13│ 11.1 14│ 11.9 15│ 12.7 16│ 13.5 17│ 14.4 18│ 15.3 19│ 16.3 20│ 17.4 21│ 18.5 22│ 19.6 23│ 20.9 24│ 22.2 25│ 23.5 26│ 25.0 ─────┴───────────── From the gas volume reduced by the above formula the nitric acid is calculated as follows: One cubic centimeter of nitric oxid weighs at 0° and 760 millimeters barometric pressure 1.343 milligrams. Since two molecules of NO (molecular weight sixty) correspond to one molecule of N₂O₅ (108) we have the following equation: 60 : 108 = 1.343 : x. Whence x = 2.417 milligrams, the weight of nitric acid corresponding to one cubic centimeter of nitric oxid. FIGURE 79. DE KONICK’S APPARATUS. ] FIGURE 80. END OF DELIVERY-TUBE. ] =467. DeKonick’s Modification of Schloesing’s Method.=—This modification consists in an arrangement of the gas delivery-tube, whereby the regurgitation of the water in the measuring burette into the evolution flask is prevented by a device for sealing the delivery-tube with mercury.[299] The apparatus is arranged as shown in Fig. 79. The flask in which the decomposition takes place is provided with a long neck, into which a side tube is sealed and bent upwards, carrying a small funnel attached to it by rubber tubing. The piece of rubber tubing carries a pinch-cock, by means of which the solution containing the nitrate and hydrochloric acid can be introduced into the flask. The small gas delivery-tube is arranged as shown in the figure, and carries at the end next the burette a device shown in Fig. 80. The cork represented in this device has radial notches cut in it, so as to permit of a free communication between the water in the burette and in the pneumatic trough. The open end of the burette, when the apparatus is mounted ready for use, rests on the notched surface of the cork, and the end of the delivery-tube is placed in the crystallizing dish resting on the bottom of the pneumatic trough. The end of the delivery-tube, as indicated, has fused onto it a vertical tube open at both ends and six to seven centimeters in length, and carrying the notched cork already described. The crystallizing dish in the bottom of the pneumatic trough is filled with mercury until the point of union of the delivery-tube with the vertical end is sealed to the depth of a few millimeters. As the gas is evolved it bubbles up through the mercury into the measuring tube and the displaced water passes out through the notches in the cork. Should any back pressure supervene the mercury at once rises in the delivery-tube which is of such a length as to prevent its entrance into the flask. The operation can then be carried on with absolute safety. To make an estimation there are placed in the flask about forty cubic centimeters of ferrous chlorid solution containing about 200 grams of iron to the liter, and also an equal volume of hydrochloric acid of one and one-tenth specific gravity. The side tube is also filled up to the funnel with the acid. The contents of the flask are boiled until all air is expelled, which can be determined by holding a test-tube filled with water over the end of the delivery-tube. The solution containing the nitrate is next placed in the funnel, the pinch-cock opened and the liquid allowed to run into the flask by means of the partial vacuum produced by stopping the boiling and allowing the mercury to rise in the delivery-tube. All the solution is washed into the flask by successive rinsings of the funnel with hydrochloric acid, being careful to allow no bubble of air to enter. The contents of the flask are again raised to the boiling-point and the nitric oxid evolved collected in the nitrometer. The solution examined should contain enough nitrate to afford from sixty to eighty cubic centimeters of gas. Without refilling the flask, from eight to nine determinations can be made by regenerating the ferrous chlorid by treatment with zinc chlorid. Care must be exercised not to add the zinc chlorid in excess, otherwise ammonia and not nitric oxid will be produced. The side tube and funnel must also be carefully freed from zinc chlorid by washing with hydrochloric acid. =468. Schmidt’s Process.=—In the case of a water, or the aqueous extract of a soil, according to the content of nitric acid, from fifty to one hundred cubic centimeters are evaporated to thirty cubic centimeters, and the residue sucked into the generating flask of the apparatus, Fig. 81, and, with the rinsings with distilled water, evaporated again to from twenty to thirty cubic centimeters, and the flask then connected, as shown in the figure, to a Schliff measuring apparatus, B.[300] This apparatus is previously filled to _i_ with mercury, and the bulb _g_ connected with _k_ by a rubber tube. FIGURE 81. SCHMIDT’S APPARATUS. ] The apparatus is then filled with a twenty per cent, previously boiled and still warm, caustic soda solution until the bulb _g_ is partially filled when raised a little above the cock _h_. Then _h_ is closed and _g_ held, by an appropriate support, on about the same level with _h_. The cock at _b_ is then closed and _e_ opened. Meanwhile the ebullition in the flask is continued, and the air bubbles rising in the Schliff apparatus are removed, from time to time, by carefully opening _h_ and raising _g_. When bubbles no longer come over, the cock at _e_ is closed and at _b_ opened, and the steam issuing at _a_ is conducted through a mixture of ferrous chlorid and strong hydrochloric acid to free it, as far as possible, from air. When the contents of the flask have been evaporated to about five cubic centimeters, _b_ is closed and the lamp at once removed. By carefully opening _b_ about ten cubic centimeters of a mixture of ferrous chlorid and hydrochloric acid are allowed to enter the flask, when _b_ is closed and the flask slowly heated until the positive pressure is restored. The pinch-cock _e_ is then opened and the contents of the flask evaporated nearly to dryness. The cock _e_ is again closed and the flame removed. Another quantity (fifteen cubic centimeters) of ferrous chlorid and hydrochloric acid solution is sucked into the flask and the process of distillation repeated, whereby the whole of the nitric oxid is collected in _h_. The nitric oxid evolved is measured in the usual way and calculated to nitric acid, one cubic centimeter of nitrogen dioxid being equal to 2.417 milligrams of nitric acid. =469. Merits of the Ferrous Chlorid Process.=—The possibility of an accurate determination of nitrates; by decomposition with a ferrous salt in presence of an excess of acid, has been established by many years of experience and by the testimony of many analysts. The method is applicable especially where the quantity of nitrate is not too small and when organic matter is present. In the case of minute quantities of nitrate, however, the process is inapplicable and must give way to some of the colorimetric methods to be hereafter described. In respect of the apparatus modern practice has led to the preference of that form which does not require the use of carbon dioxid for displacing the air. Steam appears to be quite as effective as carbon dioxid and is much more easily employed. That form of apparatus should be used which is the simplest in construction and has the least cubical content. The measurement of the evolved gas is most simply made by collecting over lye in an azotometer, reading the volume, noting the reading of the barometer and thermometer and then reducing to standard conditions of pressure and temperature by the customary calculations. Where a very strong lye is used the tension of the aqueous vapor may be neglected. While every analyst should have a thorough knowledge of the ferrous chlorid method and the principles on which it is based it can not be compared in simplicity to the later methods with pure nitrates which are based on the conversion of the nitric acid into ammonia by the action of nascent hydrogen. In accuracy, moreover, it does not appear to have any marked advantage over the reduction methods. =470. Mercury and Sulfuric Acid Method.=—This simple and accurate method of determining nitric acid in the absence of organic matter is known as the Crum-Frankland process.[301] The method rests on the principle of converting nitric acid into nitric oxid by the action of mercury in the presence of sulfuric acid. The operation as at first described is conducted in a glass jar eight inches long by one and a half inches in diameter filled with mercury and inverted in a trough containing the same liquid. The nitrate to be examined, in a solid form, is passed into the tube together with three cubic centimeters of water and five of sulfuric acid. With occasional shaking, two hours are allowed for the disengagement of the gas, which is then measured. =471. Warington’s Modification.=—A graduated shaking tube is employed which allows the nitrate solution and oil of vitriol to be brought to a definite volume. The nitrate solution, with rinsings, is always two cubic centimeters and enough sulfuric acid is added to increase the volume to five cubic centimeters. The sulfuric acid should give no gas when shaken with distilled water. Any gas given off in the apparatus before shaking, is not expelled but is included in the final result. The persistent froth sometimes noticed where some kinds of organic matter are present, is reduced by the addition of a few drops of hot water through the stop-cock of the apparatus. The nitric oxid is finally measured in Frankland’s modification of Regnault’s apparatus. This method, accurate for pure nitrates, unfortunately fails in the presence of any considerable amount of organic matter. According to Warington’s observations the presence of chlorids is no hindrance to the accurate determination of both nitric and nitrous acids by the mercury method. This simplifies the operation as carried on by Frankland who directs that any chlorin present, be removed before the determination of the nitric acid is commenced. =472. Noyes’ Method.=—In the analyses made by Noyes for the National Board of Health, the Crum-Frankland method was employed.[302] The apparatus used was essentially that which is now known as Lunge’s nitrometer and it will be described in the next paragraph. No correction is made by Noyes for the tension of aqueous vapor in the measurement of the nitric oxid because of the moderate dilution of the sulfuric acid by the liquid holding the nitric compounds in solution. The chlorin was not removed from the dry residue of the evaporated water as its presence in moderate quantity does not interfere with the accuracy of the process. In order to obtain the amount of nitrogen in the form of nitrates, the total volume of nitric oxid must be diminished by that due to nitrites present, which must be determined in a separate analysis. The method of manipulation is given in the following paragraph. FIGURE 82. LUNGE’S NITROMETER. ] =473. Lunge’s Nitrometer.=—The apparatus employed by Noyes, in a somewhat more elaborate form, is known as Lunge’s nitrometer.[303] This apparatus is shown in Fig. 82. It consists of a burette, _a_, divided into one-fifth cubic centimeters. At its upper end it is expanded into a cup-shaped funnel attached by a three-way glass stop-cock. Below, the burette is joined to a plain tube, _b_, of similar size, by means of rubber tubing. The apparatus is first filled with mercury through the tube _b_, the stop-cock being so adjusted as to allow the mercury to fill the cup at the top of _a_. The cock is then turned until the mercury in the cup flows out through the side tube carrying the rubber tube and clamp. The three-way cock is closed, and the solution containing the nitrate placed in the cup. By lowering the tube _b_ and opening the cock the liquid is carefully passed into _a_, being careful to close the cock before all the liquid has passed out of the cup. By repeated rinsings with pure concentrated sulfuric acid, every particle of the nitric compound is finally introduced into _a_, together with a large excess of sulfuric acid. The total volume of the introduced liquid should not exceed ten cubic centimeters. The mixture of the mercury, nitric compound, and sulfuric acid is effected by detaching _a_ from its support, compressing the rubber connection between _a_ and _b_, placing _a_ nearly in a horizontal position, and quickly bringing it into a vertical position with vigorous shaking. After about five minutes the reaction is complete, and the level of the liquids in the two tubes is so adjusted as to compensate for the difference in specific gravity between the acid mixture in _a_ and the mercury in _b_; in other words, the mercury column in _b_ should stand above the mercury column in _a_ one-seventh of the length of the acid mixture in _a_. This secures atmospheric pressure on the nitric oxid which has been collected in _a_. The measured volume of nitric oxid should be reduced to 0° and 760 millimeters barometric pressure. Each cubic centimeter of nitric oxid thus obtained corresponds to 1.343 milligrams NO; 2.417 milligrams N₂O₅; 4.521 milligrams KNO₃; 1.701 milligrams N₂O₃; 2.820 milligrams HNO₃; and 3.805 milligrams NaNO₃. =474. Lunge’s Improved Apparatus.=—Lunge has lately improved his apparatus for generating and measuring gases and extended its applicability.[304] The part of it designed to measure the volume of a gas is the same in all cases. For generating the gas, the apparatus varies according to the character of the substance under examination. The measuring apparatus is shown in Fig. 83. It is composed essentially of three tubes, conveniently mounted on a wooden holder with a box base for securing any spilled mercury. The support is not shown in the illustration. The tubes A, B, C, are mutually connected by means of a three-way tube and rubber tubing with very thick walls to safely hold the mercury without expansion. In the middle of the measuring tube A, is found a bulb of seventy cubic centimeters capacity. Above and below the bulb the tube is divided into tenths of a cubic centimeter, and its diameter is such, _viz._, 11.3 millimeters, that each cubic centimeter occupies a length of one centimeter. The upper end of A is closed with a glass cock with two oblique perforations, by means of which communication can be established at will, either through _e_ with the apparatus for generating the gas, or through _d_ with the absorption apparatus, or the opening be completely closed. FIGURE. 83. LUNGE’S IMPROVED APPARATUS. ] The volume of air under the observed conditions which would measure exactly 100 cubic centimeters at 0° and 760 millimeters pressure of mercury, is calculated by the formula V = (100(273 + _t_)760)/(273(_b_ − _f_)); where _t_ equals observed temperature, _b_ the barometric pressure less the correction noted above and _f_ the tension of the vapor of water under existing conditions. For example: Let the temperature be 18° Barometric reading 755 Correction for _t_ 2 Corrected barometer 753 Vapor of water tension 16 Then V = (100(273 + 18)760)/(273(753 − 16)) = 109.9. This indicates that 109.9 cubic centimeters of air would occupy a volume of 100 cubic centimeters when subjected to standard conditions. The tubes A, B, and C are filled with mercury of which about two and a half kilograms will be required. By means of the leveling tube B, the stopper in C being opened, the mercury in C is brought exactly to 109.9 cubic centimeters. The stopper in C is then closed, mercury poured into D, which is then closed with a rubber stopper, carrying a small glass tube as indicated in the figure. The leveling tube B serves to regulate the pressure on the gas in A and this is secured by depressing or elevating it as the case may require. The tube for reducing the volume to standard conditions of temperature and pressure, _viz._, 0° and 760 millimeters of mercury, is shown in C. In its narrow part which has the same internal diameter as A it is graduated into tenths of a cubic centimeter. The upper end of C is furnished with a heavy glass neck D surmounted by a glass cup. In the neck is placed a ground-glass stopper, carrying a groove below, which corresponds to a similar groove above in the side of the neck whereby communication can be established at will between the interior of C and the exterior. The joint is also sealed by pouring mercury into D as is shown in the figure. When the stopper is well ground and greased the reduction tube may be raised or lowered as much as may be necessary without any danger of escape or entrance of gas. To determine the position of the reduction tube C the reading of the barometer and thermometer at room temperature is taken. From the reading of the barometer subtract one millimeter if the temperature be below 12°, two millimeters at a temperature from 12° to 19°, three from 20° to 25°, and four above 25°. When a gas has been introduced into the measuring tube A it is brought to the volume which it would assume under standard conditions by adjusting the tube C in such a way as to bring the level of mercury in C and A to the same point and the level of the mercury in C is exactly at 100 cubic centimeters. The gas in A is then at the volume which it would occupy under standard conditions and this volume can be directly read. This adjustment is secured by moving the tubes B and C up or down. If gases are to be measured wet, a drop of water should be put on the side of the upper part of C, and, if dry, of sulfuric acid, before the adjustment for temperature and pressure. =475. Method of Manipulation.=—By the action of mercury in the presence of sulfuric acid, the nitrogen in nitrates, nitrites, nitrosulfates, nitroses, nitrocellulose, nitroglycerol, and the greater number of explosives, may be obtained and measured as nitric oxid. The nitrogen compounds are decomposed in the apparatus shown in Fig. 84. To make an analysis, the apparatus is filled with mercury, through F, until the two openings in the cock and _i_ are entirely occupied with that liquid. The cock _h_ is then closed, and the nitrogen compound, in solution, introduced through _g_, care being taken that no air enters _g_ when F is depressed and _h_ opened to admit the sample. The funnel _g_ is washed several times with a few drops of sulfuric acid, which are successively introduced into G. The total liquid introduced should not exceed ten to fifteen cubic centimeters, of which the greater part should be sulfuric acid. The rubber tube connecting G and F is carefully closed with a clamp and G violently shaken for a few minutes until no further evolution of nitric oxid takes place. In shaking, the apparatus should be so held as to prevent the escape of the mercury from the small tube _i_ by keeping it closed with the finger or drawing over it a rubber cap. FIGURE 84. LUNGE’S ANALYTIC APPARATUS. ] After the evolution of the gas has ceased, the tube _e_, Fig. 83, is brought into contact with _i_, Fig. 84, and the two are joined by a tight-fitting piece of rubber tubing in such a way as to exclude any particle of air. The tube F, Fig. 84, is lifted and B and C, Fig. 83, depressed. On carefully opening the cocks _h_ and _b_ and bringing _i_ and _e_ into union, the gas is passed from G into A. When all the gas has entered A and the acid mixture from G has reached _b_ the latter is closed, and also _h_. The apparatus G is disconnected and removed. The gas in A is then reduced to normal conditions by manipulating the reduction tube C in the manner already described. The gas in A is measured dry by reason of having been generated in presence of rather strong sulfuric acid. Consequently, for this operation the adjustment of the volume of gas in C should be made in contact with a drop of strong sulfuric acid. In order to make the readings, a quantity of material must be taken which will give less than thirty or from 100 to 140 cubic centimeters of nitric oxid. The quantities of the different compounds of nitric acid corresponding to the number of cubic centimeters of nitric oxid, measured under standard conditions, are shown in the following table: CORRESPONDING TO ———————————— ———————————— ———————————— Cubic Weight in N₂O₃ in HNO₃ in NaNO₃ in centimeters milligrams. milligrams. milligrams. milligrams. of NO. 1 1.343 1.701 2.820 3.805 2 2.682 3.402 5.640 7.610 3 4.029 5.103 8.460 11.415 4 5.372 6.804 11.280 15.220 5 6.715 8.506 14.100 19.025 6 8.058 10.206 16.920 22.830 7 9.401 11.907 19.740 26.635 8 10.744 13.608 22.560 30.440 9 12.087 15.309 25.380 34.245 =476. Utility of the Method.=—Where it is desirable that the nitric oxid method be used, and at the same time heating be avoided, the decomposition of a nitrate by means of metallic mercury and sulfuric acid affords a convenient and accurate procedure. But, as a rule, there is no objection to the application of the lamp, and in such cases the mercury method appears to have no advantage over the ferrous chlorid process. Nevertheless, in the hands of a skilled worker the results are reliable, and the process is a quicker one, on the whole, than by distillation with ferrous chlorid and hydrochloric acid. This method, however, can not be recommended as in any way superior to the reduction methods to be hereinafter described. ESTIMATION OF NITRIC ACID BY OXIDATION OF A COLORED SOLUTION. =477. Method of Boussingault.=—The process for the estimation of nitric acid by the decoloration of a solution of indigo is due originally to Boussingault.[305] In this method the extract, obtained by washing slowly 200 grams of soil until the filtrate amounts to 300 cubic centimeters, is evaporated until its volume is no greater than two or three cubic centimeters, and it is transferred to a test-tube, with washings, and again evaporated in the tube until the volume is not greater than that last mentioned. A few drops of solution of indigo are added, and then two cubic centimeters of pure hydrochloric acid; the whole is then heated. As the color of the indigo disappears more is added. When the color ceases to fade, the liquid in the test-tube is concentrated by boiling. If concentration fail to destroy the blue or green color, another one-half cubic centimeter of hydrochloric acid is introduced. The reaction is completed when neither concentration nor fresh addition of hydrochloric acid destroys the excess of indigo present. The color produced by a small excess of indigo is a bright sap-green; this tint is the final reaction sought. The small excess of indigo necessary to produce a green color is deducted in every experiment. When more than mere traces of organic matter are present, Boussingault advises that the nitric acid be first separated by distillation and then reduced by the indigo solution. For this purpose the concentrated solution of the nitrate, two or three cubic centimeters, is placed in a small tubulated retort with two grams of manganese dioxid in fine powder. The retort is next half filled with fragments of broken glass, over which is poured one cubic centimeter of concentrated sulfuric acid. The retort is heated carefully by means of a small flame, which is kept in motion so as to successively come in contact with all parts of the bottom of the retort. The distillate is received in a graduated test-tube which is kept cool. The distillation is continued until the vapors of sulfuric acid begin to appear. The apparatus is allowed to cool, the stopper of the retort removed, two cubic centimeters of water introduced, and the distillation again made until fumes of sulfuric acid are again seen. The distillation with water is made twice in order to remove every trace of nitric acid from the retort. The distillate is neutralized with a solution of potassium hydroxid and concentrated to two cubic centimeters, and the nitric acid estimated in the manner already described. The manganese dioxid used should be previously well washed and the sulfuric must be free of nitric acid. _Preparation of the Indigo Solution._—Fifty grams of indigo in fine powder are digested for twenty-four hours, at 40°, in a liter of distilled water. The water is then poured off and replaced with a fresh supply. After the second decantation the residue is treated with 750 cubic centimeters of equal parts of water and pure concentrated hydrochloric acid and boiled for an hour. After cooling, the undissolved portion is collected on a filter and washed at first with hot, and afterwards with cold water, until the filtrate is no longer colored and is free of acid. The dried residue is treated with ether under a bell-jar, or in a continuous extraction apparatus, until the ether is only of a faint blue tint. The fifty grams of indigo at first taken will give about twenty-five grams of the purified article, which, however, will still leave a little ash on combustion. _Solution in Sulfuric Acid._—Five grams of the purified indigo are placed in a flask having a ground-glass stopper, treated with twenty-five grams of fuming sulfuric acid, and allowed to digest two or three days at a temperature of from 50° to 60°. From seventy to 200 drops of the solution thus made are placed in 100 cubic centimeters of water for use in the process. _Standardization of the Indigo Solution._—The solution as prepared above is standardized by a solution of one gram of pure potassium nitrate in 1,000 cubic centimeters of distilled water. The oxidation of the indigo solution is accomplished as described above. For this strength of standard nitrate solution two cubic centimeters are taken corresponding to two milligrams of potassium nitrate. The indigo solution for this strength should have only twenty drops of the sulfuric acid solution of indigo to 100 cubic centimeters of water. If twenty grams of potassium nitrate are taken for 1,000 cubic centimeters of the standard solution then 200 drops of the sulfindigotic acid should be used to 100 cubic centimeters of water. =478. Method of Marx.=—As usually practiced, the indigo method is conducted according to the variation described by Marx.[306] There are required for the process the following reagents and apparatus: _a._ A solution of pure potassium nitrate containing 1.8724 grams per liter. One cubic centimeter of the solution is equivalent to one milligram of nitric anhydrid (N₂O₅). _b._ A solution of the best indigo carmine in water which should be approximately standardized by solution in the manner described hereafter, and then diluted so that six to eight cubic centimeters equal one milligram of nitric acid. _c._ Chemically pure sulfuric acid of specific gravity 1.842, perfectly free from sulfurous and arsenious acids and nitrogen oxids. _d._ Several thin flasks of about 200 cubic centimeters capacity. _e._ A small cylindrical measure holding fifty cubic centimeters and divided into cubic centimeters. _f._ A Mohr’s burette divided into tenths of a cubic centimeter. _g._ A twenty-five cubic centimeter pipette or another burette. _h._ A five cubic centimeter pipette divided into cubic centimeters or half cubic centimeters. _i._ A measuring flask of 250 cubic centimeters capacity. _Preliminary Trial._—Twenty-five cubic centimeters of the sample are transferred to a flask; the fifty cubic centimeter measure is filled with sulfuric acid and the burette with indigo solution. The sulfuric acid is added to the sample all at once, shaken for a moment, and the indigo run in as quickly as possible with shaking until a permanent greenish tint is produced. If the sample do not require more than twenty cubic centimeters of indigo solution of the above strength, it can be titrated directly, otherwise it must be diluted with a proper quantity of pure water, and subjected again to the preliminary trial. _The Actual Titration._—(1) Twenty-five cubic centimeters of the sample properly diluted if necessary, are measured and poured into a flask, and as much indigo as was used in the preliminary trial, is added; a quantity of sulfuric acid, equal in volume to the liquid in the flask, is added all at once, the mixture shaken, and indigo solution run in quickly out of the burette until the liquid remains permanently of a greenish tint. (2) The last experiment is repeated as often as may be necessary adding to the water at first half a cubic centimeter less indigo than the total quantity used previously, afterwards proceeding as in (1) until the final test shows too little indigo used. (3) From the rough titration of the indigo, calculate the amount of potassium nitrate solution corresponding with the indigo solution used in (2), multiply the result by ten, transfer this quantity of the standard nitrate solution to a 250 cubic centimeter flask, fill with pure water to the mark, and titrate twenty-five cubic centimeters of this fluid with indigo as in (2). If the quantity of indigo solution used is nearly the same as that required in (2), its exact value may be calculated, but if it is not, another nitrate solution may be made up in the 250 cubic centimeter flask, more closely resembling the sample in strength, and the titration with the indigo solution must be repeated. (4) If the water contain any considerable amount of organic matter, it must first be destroyed by potassium permanganate. In this case, the estimation of the organic matter and nitric acid may be conveniently combined. The use of permanganate in the above case is likely to introduce an error as has been shown by Warington. The method therefore can not be recommended in the presence of organic matter. =479. Method of Warington.=—The modification of the indigo method as used by Warington, applicable only in absence of organic matter, is the one chiefly employed in England.[307] Instead of the ordinary indigo of commerce, indigotin is used. The normal solution of the coloring matter is made of such a strength as to be equivalent to a solution of potassium nitrate containing 0.14 gram of nitrogen per liter. Where large quantities of the coloring matter are to be used it is advisable to prepare it about four times the strength given above and then dilute it as required. Four grams of sublimed indigotin will furnish more than two liters of the color solution. The solution is prepared as follows: Four grams of indigotin are digested for a few hours with five times that weight of Nordhausen sulfuric acid, diluted with water, filtered, and made up to a volume of two liters. The strength of the indigotin solution is determined with a solution of potassium nitrate of the strength mentioned above. The process is performed as follows: From ten to twenty cubic centimeters of the standard nitrate solution are placed in a wide-mouthed flask of about 150 cubic centimeters capacity. A portion of the indigotin solution is next added, such as will be deemed sufficient for the process, and the whole is well mixed. Strong sulfuric acid is next measured out from a burette into a test-tube, in volume equal to the united volumes of the nitrate solution and indigotin. The whole of the sulfuric acid is then poured as quickly as possible, into the solution in the flask and rapidly mixed, and the flask transferred to a calcium chlorid bath, the temperature of which should be maintained at 140°. It is essential to the success of the operation that the sulfuric acid should be mixed with the greatest rapidity. It should be poured in at once and the whole well shaken without waiting for the test-tube containing the acid, to drain. The flask should be covered by a watch-glass while it is held in the bath. As soon as the larger part of the indigotin is oxidized the flask in the bath should be gently rotated. With very weak solutions of nitrate it may be necessary sometimes to keep the flask in the bath for five minutes. When the indigo color is quickly discharged it shows the presence of nitric acid in considerable excess and a considerably larger quantity of indigo must be taken in the next experiment. The experiments are continued until just the quantity of indigo necessary to consume the nitric acid is taken, the amount of indigo being in very slight excess, not exceeding one-tenth cubic centimeter of the indigo solution used. The tint produced by the small excess of indigo remaining is best seen by filling the flask with water. On substances of approximately known strength about four experiments are usually necessary to determine the amount of indigo to be taken, but with unknown substances a larger number may be necessary. Usually in determinations of this kind it is directed to use double the volume of sulfuric acid mentioned above. In this case not only is the quantity of indigo oxidized much greater than with a smaller portion of acid, but the prejudicial effect of organic matter is also greater than when the smaller quantity of acid is employed. An indigo solution standardized as above is strictly to be used for a solution of nitrate of the strength employed during the standardization. The quantity of indigo oxidized in proportion to the nitric acid present diminishes as the nitrate solution becomes more dilute. Instead of determining this during each series of experiments it may be estimated once for all and a table of corrections used. The following table is based upon experimental determinations: Strength of Indigo Difference Nitrogen Difference Difference niter required, between corresponding between the in the solution cubic amounts of to one cubic nitrogen nitrogen used. centi- indigo, centimeter of values, values for a meters. cubic indigo, gram. gram. difference centi- of one cubic meters. centi- meter in the amount of indigo, gram. ⁸⁄₆₄ Normal 10.00 0.000035000 ⁷⁄₆₄ „ 8.71 1.29 0.000035161 0.000000161 0.000000125 ⁶⁄₆₄ „ 7.43 1.28 0.000035330 0.000000169 0.000000132 ⁵⁄₆₄ „ 6.14 1.29 0.000035627 0.000000298 0.000000231 ⁴⁄₆₄ „ 4.86 1.28 0.000036008 0.000000381 0.000000298 ³⁄₆₄ „ 3.57 1.29 0.000036763 0.000000756 0.000000586 ²⁄₆₄ „ 2.29 1.28 0.000038209 0.000001445 0.000001129 ¹⁄₆₄ „ 1.00 1.29 0.000043750 0.000005541 0.000004295 The table is used as follows: Suppose that twenty cubic centimeters of water under examination have required 5.36 cubic centimeters of indigo solution for the oxidation of the nitric acid contained therein. By inspection of the table it is seen that this number is five-tenths cubic centimeter above the nearest quantity given; _viz._, 4.86 cubic centimeters. From the last column in the table it is found that the correction for five-tenths cubic centimeter of indigo solution is 0.000000149 cubic centimeter, being half that for the one cubic centimeter given in the table. This is to be subtracted from the unit value in nitrogen given in the first “gram” column of the table; _viz._, 0.000036008. It is thus seen that the 5.86 cubic centimeters of indigo solution are equivalent to 0.000035859 gram of nitrogen per cubic centimeter. The water under examination, therefore, contains nine and six-tenths parts of nitrogen as nitric acid per million. Attention must also be paid in standardizing indigo solutions to the initial temperature of the solutions. A rise in the initial temperature will be attended by a diminution in the quantity of indigo oxidized. Experiments with a room temperature of 10° and a room temperature of 20°, being the initial temperatures of the experiments, showed that at the higher temperature the amount of indigo consumed was about five per cent less when the strong solutions of nitrate were employed. The indigo solution should, therefore, be standardized at the same temperature at which the determinations are made. If twenty cubic centimeters of the standard nitrate solution employed be used in setting the indigo solution, this standard will enable the operator to determine nitric acid up to 17.5 parts of nitrogen per million in water or soil extracts. The presence of an abundance of chlorids in the water under examination tends to diminish the content of nitric acid found, and also tends to introduce an error, which is sometimes of a plus and sometimes of a minus quantity, according to the strength of the nitric acid present. The reaction is shortened in weak solutions by the presence of chlorids, and the quantity of indigo consumed is consequently increased. The error introduced by chlorids is usually of an insignificant nature. On account of the interference of organic matters with the reaction of indigo it is not of much use in the examination of nitrates washed out of soils, although in some cases the results may be quite accurate. This method must, therefore, be considered as applicable, in general, to waters or soil extracts which contain little or no organic matter. In analytical work pertaining particularly to agriculture, the use of the indigo method for determining nitric acid has been largely employed, both in the analyses of soil extracts and drainage and irrigation waters. The method, however, can hardly survive as an important one in such work in competition with more modern and speedy processes of analysis. DETERMINATION OF NITRIC NITROGEN BY REDUCTION TO AMMONIA. =480. Classification of Methods.=—When nitrogen is present in a highly oxidized state, _e. g._, as nitric acid, it may be quickly and accurately estimated by reduction to ammonia. This action is effected by the reducing power of nascent hydrogen, and this substance may be secured in the active state by the action of an acid or alkali on a metal, or by means of an electric current. The processes depending on the use of a finely divided metal in the presence of an acid or alkali have come into general use within a few years, and are now employed generally instead of the more elaborate estimations depending on the use of copper oxid or indigo. The typical reaction which takes place in all cases is represented by the following equation: 2HNO₃ + 8H₂ = 2NH₃ + 6H₂O. The method will be considered under three heads; _viz._, 1. Reduction in an alkaline solution; 2. Reduction in an acid solution; 3. Reduction by means of an electric current. In the first class of processes the reduction and distillation may go on together. In the second class the reduction is accomplished first and the distillation effected afterwards, with the addition of an alkali. In the third class of operations the reduction is accomplished by means of an electric current and the ammonia subsequently obtained by distillation, or determined by nesslerizing. These processes may be applied to rain and drainage waters, and to soil extracts. On account of the ease with which the analyses are accomplished, the short time required and the accuracy of the results, the reduction methods for nitrates have already commended themselves to analysts, and are quite likely to supersede all others for practical use where weighable quantities of nitrates are present. For the minute traces of nitrates found in rain and drainage waters, and in some soil extracts, the reduction method may also be applied, but in these cases the ammonia which is formed must be determined by colorimetry (nesslerizing) and not by distillation. The processes about to be described are especially applicable to the examination of soils and waters rich in nitrates. REDUCTION IN ALKALINE SOLUTIONS. =481. Provisional Method of the Association of Official Agricultural Chemists.=[308]— _Extraction of the Nitrates._—Place one kilogram of the dried soil, calculated to water-free substance, on a percolator of glass or tin. Moisten the soil thoroughly with pure distilled water, and allow to stand for half an hour. Add fresh portions of pure distilled water until the filtrate secured amounts to one liter. If the first filtrate be cloudy before use it may be refiltered. _Qualitative Test for Nitrates._—Evaporate five cubic centimeters of the soil extract in a porcelain crucible, having first dissolved a small quantity of pure brucin sulfate therein. When dry, add to the residue a drop of concentrated sulfuric acid free of nitrates. If the nitrate calculated as potassium nitrate does not exceed the two-thousandth part of a milligram only a pink color will be developed; with the three-thousandth part of a milligram a pink color with reddish lines; with the four-thousandth part of a milligram a reddish color; with the five-thousandth part of a milligram a distinct red color. _Estimation of the Nitrates._—Evaporate 100 cubic centimeters of the soil extract to dryness on a steam-bath. Dissolve the soluble portions of the residue in 100 cubic centimeters of ammonia-free distilled water, filtering out any insoluble residue. Place the solution in a flask, add ten cubic centimeters of sodium amalgam, stopper the flask with a valve which will permit the escape of hydrogen, and allow to stand in a cool room for twenty-four hours. Add fifty cubic centimeters of milk of lime and titrate the ammonia produced by distillation, with standard acid and estimate as nitrogen pentoxid. Where the amount of ammonia is small, nesslerizing may be substituted for titration. _Preparation of Sodium Amalgam._—Place 100 cubic centimeters of mercury in a flask of half a liter capacity; warm until paraffin will remain melted over the surface; drop successively in the paraffin-covered mercury, pieces of metallic sodium of the size of a pea until 6.75 grams have united with the mercury. The amalgam contains then 0.5 per cent of metallic sodium and may be preserved indefinitely under the covering of paraffin. =482. Method of the Experiment Station at Möckern.=[309]—The principle of this reaction is based on the reducing action exercised by nascent hydrogen on a nitrate, the hydrogen being generated by the action of soda-lye on a mixture of zinc dust and finely divided iron. Ten grams of nitrate are dissolved in 500 cubic centimeters of water. Of this solution twenty-five cubic centimeters, corresponding to one-half gram, are placed in a distillation flask of about 400 cubic centimeters capacity, 120 cubic centimeters of water added, and about five grams of well-washed and dried zinc dust and an equal weight of reduced iron. To the solution are added eighty cubic centimeters of soda-lye of 32° B. The flask is then connected with the condensing apparatus and the distillation carried on synchronously with the reduction, the ammonia being collected in twenty cubic centimeters of titrated sulfuric acid. The distillation is continued from one to two hours, or until 100 cubic centimeters have been distilled, and the remaining sulfuric acid is titrated in the usual way. Soil extracts and sewage waters should be concentrated until they have approximately the proportion of nitrates given above. =483. Method of Devarda.=—The inconvenience due to slow action and other causes, arising from the use of pure metals in the reduction of nitrates to ammonia, has been overcome, to some extent, by Devarda, by use of an alloy, in a state of fine powder, consisting of aluminum, copper, and zinc.[310] The alloy consists of forty-five per cent of aluminum, fifty per cent of copper, and five per cent of zinc. In dissolving, the copper is left in a finely divided state, which is a great help in distillation in preventing bumping. The analytical process is carried out as follows: The solution containing the nitrate, in quantity equivalent to about one-half gram of potassium nitrate, is placed in a flask having a capacity of about one liter, and diluted with sixty cubic centimeters of water and five cubic centimeters of alcohol, and then forty cubic centimeters of caustic potash solution added of specific gravity one and three-tenths. From two to two and one-half grams of the alloy, described above, are introduced, and the flask attached to a condenser with a receiver containing standard acid. The connection between the flask and the condenser is made by means of a tube having on the limb next the flask a bulb filled with glass beads to prevent the contents of the flask splashing over into the receiver, and on the other limb another bulb to prevent the acid in the receiver finding its way into the distillation flask, should regurgitation occur. When the flask has been thus connected with the condenser it is gently heated for half an hour, at the end of which time the evolution of hydrogen will have slackened or ceased, and then the distillation is begun, at first cautiously, until the zinc of the alloy has completely dissolved, and then more vigorously, the time necessary being about twenty minutes from the time when the contents of the flask begin to boil. The distillate is caught in standard acid and the ammonia determined by backward titration in the ordinary way. It is to be noted that the strength of the alkali used is of importance, as if it be too strong, the action on the alloy is unduly vigorous at the beginning of the operation, and if too weak, the contents of the flask have to be heated overmuch, the result in both cases being the formation of a fine spray of caustic solution, which is very difficult to stop, even with complicated washing attachments to the distilling flask. The test analyses on pure nitrates are satisfactory. This method has been used with satisfaction in the laboratory of the Department of Agriculture, but does not appear to have any special advantage over the process of Ulsch, to be described further on. =484. Variation of Stoklassa.=—Stoklassa has subjected the method of Devarda to a comparative test with the following methods:[311] 1. Wagner’s Schloesing-Grandeau method. 2. Lunge’s nitrometer method. 3. Stutzer’s method. FIGURE 85. STOKLASSA’S NITRIC ACID APPARATUS. ] The reduction takes place in a copper erlenmeyer, A, Fig. 85, in which, in addition to the solution containing the nitrate, are placed 200 cubic centimeters of water, forty cubic centimeters of potassium hydroxid solution of 33° B., five cubic centimeters of alcohol, and finally two and one-half grams of the finely powdered Devarda alloy. The distillate passes through a tube, B, filled with glass pearls and into the condenser D, through the bulbs, C C′. After the flask is connected with the distilling apparatus, it is gently warmed and the reduction is ended in about twenty minutes. The ammonia which is formed is then distilled into E, containing the standard acid, S, requiring about twenty minutes more. The comparative results given, show that the Devarda method is equally as accurate as any of the other methods mentioned, giving practically theoretical results. In so far, however, as speed of an analysis, is concerned the first place is awarded to the Lunge nitrometer method, with which a complete analysis can be made in from thirty to forty minutes. In the second rank, so far as speed is concerned, the Devarda method is recommended. All the methods give accurate results. =485. Method of Sievert.=[312]—Two grams of potassium or sodium nitrate are dissolved and made up to 1,000 cubic centimeters. Fifty cubic centimeters of the solution are placed in a 600 cubic centimeter flask and diluted with fifty cubic centimeters of water, and from eighteen to twenty grams of caustic alkali added. After the alkali is dissolved, seventy-five cubic centimeters of ninety-six per cent alcohol are added and a few pieces of bone-black to prevent foaming. From ten to fifteen grams of zinc or iron dust are then added to the flask which is closed and connected with a =ᥩ= tube holding about 200 cubic centimeters, which contains about ten cubic centimeters of normal sulfuric acid. This =ᥩ= tube is kept cool by being immersed in water. The whole mixture is now allowed to stand for three or four hours and then the alcohol is distilled slowly and the ammonia formed by the reduction of the nitrates is carried over with it. The distillation lasts for about two hours. The contents of the =ᥩ= tube are carefully rinsed into a dish and the excess of sulfuric acid titrated with one-fourth normal soda-lye. For soil extracts and substances containing unknown quantities of nitric acid, a preliminary test will indicate approximately the amount thereof, and this will be an indication for the quantity to be used in the analysis. The method of Stutzer differs from the foregoing in the substitution of aluminum dust instead of iron or zinc.[313] The reducing power of aluminum, however, varies greatly according to the method in which the metal has been prepared. Pure aluminum prepared by the electric method, reduces the nitric acid much less vigorously than the metal prepared by the older methods of fusion with sodium. For this reason the method of Stutzer is not to be preferred to that of Sievert. REDUCTION IN AN ACID SOLUTION. =486. Variation of the Sodium Amalgam Process.=—This method is described by Monnier and Auriol.[314] FIGURE 86. VARIATION OF THE SODIUM AMALGAM PROCESS. ] The principle of the operation depends on the reduction of the dissolved nitrate by titrated sodium amalgam in presence of an acid, and the estimation of the quantity of nitric acid present from the deficit in the volume of hydrogen. The apparatus employed is conveniently mounted as shown in Fig. 86. The brass vessel A is movable by means of the cord on the pulley B, in such a way as to be fixed at any required altitude. It is filled with water and connected by a rubber tube to the cooling tube D. Within the cooling tube there is a graduated cylinder open at its lower end. Its upper end is connected directly with the apparatus C. The cooling tube D has a small side tube, _c_, near its upper end, by means of which the air can enter or escape when the position of A is changed. The apparatus C, in which the reaction takes place, is a glass cylinder. Its upper end is continuous with the =⟙= tube provided with the stop-cocks _a_ and _b_. One arm of the =⟙= permits connection with the graduated measuring tube by means of a rubber union. The lower end of C is closed with a large hollow ground-glass stopper, carrying a small receptacle within, so that it forms two separate water-tight compartments, open at the top. The sodium amalgam is prepared as follows: In a clay crucible are heated 400 grams of mercury, and, little by little, with constant stirring, four grams of dry sodium are added. When cold, the amalgam is placed in a burette, having a ground-glass stopper, and covered with petroleum. The strength of the amalgam is established in the following manner. A small glass thimble, ground even at the top, is filled with the amalgam and struck off even with a ground-glass straight edge. In this way the same quantity of amalgam is taken for each test. This measured portion of the amalgam is placed in the inner vessel of the glass stopper to C. Ten cubic centimeters of water, containing sixty centigrams of tartaric acid, are placed on the outer ring of the glass stopper, which is then inserted, well oiled, in C, closing it air- and water-tight. The tartaric acid solution also carries a piece of litmus paper, so that its constant acidity may be insured. The vessel A is then fixed in a position which brings the water in the graduated burette and tube D exactly to the 0 mark. The cock _a_ is next closed, _b_ opened, and C is inverted until all the amalgam is poured into the solution of tartaric acid. The evolved hydrogen mixed with the air contained in the apparatus, is passed into the graduated burette. After fifteen minutes, the reaction is ended. The water level within and without the graduated tube is restored and the volume of gas evolved noted and reduced by the usual tables to 0° and 760 millimeters pressure of the barometer. An amalgam prepared as above will give about three cubic centimeters of hydrogen for each gram. The thimble should hold from twelve to fifteen grams. The estimation of nitric acid should be made in a solution containing about one-tenth per cent of nitrate. Ten cubic centimeters are taken, to which six-tenths gram of tartaric acid is added, and placed in the outer part of the glass stopper. The rest of the process is conducted exactly as described above. The deficit in hydrogen is calculated to nitrogen pentoxid. The reduction by sodium amalgam is not so convenient a form of estimating nitric acid as many of the other forms of using nascent hydrogen. As practiced by calculating from the deficit of hydrogen, however, it has some advantages by reason of the fact that no heating is required. The presence of organic neutral bodies, or even those of an acid nature, like humus, does not, therefore, interfere with the work. Likewise, mineral bodies in solution, which are not reduced by nascent hydrogen, do not interfere with the accuracy of the reaction. =487. Method of Schmitt.=—In the method of Schmitt forty cubic centimeters of glacial acetic acid are placed in a flask of 600 cubic centimeters content, and fifteen grams of a mixture of zinc and iron dust added.[315] To this a quantity of the solution containing the nitrate, representing about half a gram of the pure nitrate, is added with constant shaking, in portions which do not evolve hydrogen too rapidly. After about fifteen minutes when the evolution of nitrogen has somewhat diminished, an additional fifteen grams of the metal dust are added. If the contents of the flask should become thick they can be diluted with thirty cubic centimeters of water. The reduction is complete in from thirty to forty minutes. The contents of the flask are now saturated with enough soda-lye not only to neutralize the excess of acetic acid, but to keep the zinc hydroxid also in solution. For this purpose about 200 cubic centimeters of soda-lye of 1.25 specific gravity are necessary. The ammonia is obtained by distillation into standard acid in the usual way. =488. Method of Ulsch.=—In practice the method of Ulsch has come into general use.[316] For the determination of nitrogen by this method half a gram of saltpeter or four-tenths gram of sodium nitrate is taken and dissolved in twenty five cubic centimeters of water, in a flask with a content of about 600 cubic centimeters. Five grams of iron reduced by hydrogen, and ten cubic centimeters of sulfuric acid diluted with two volumes of water are then added to the flask. To avoid mechanical losses during the evolution of hydrogen a pear-shaped glass stopper is hung in the neck of the flask. After the first violent evolution of hydrogen has passed, the flask is slowly heated until in about four minutes it is brought to a gentle boil. The boiling is continued for about six minutes when the reduction is complete. About fifty cubic centimeters of water are then added; also an excess of soda-lye and a few particles of zinc and the ammonia is distilled and collected in standard acid in the usual way. The method of Ulsch can also be applied, according to Fricke, to the analysis of nitrates contained in drinking and drainage waters, and it is regarded by him as one of the best methods to be employed in such investigations.[317] The method of Ulsch in this laboratory has given entirely satisfactory results, and is generally used in preference to other methods in cases where a considerable quantity of nitrates is present. It is based on the following reactions: 2KNO₃ + H₂SO₄ = K₂SO₄ + 2HNO₃ 2HNO₃ + 8H₂ = 2NH₃ + 6H₂O 2NH₃ + H₂SO₄ = (NH₄)₂SO₄. REDUCTION BY THE ELECTRIC CURRENT. =489. Method of Williams-Warington.=—From the losses which naturally occur during the evaporation of water, even with all the precautions noted, Warington was led to try some method for the determination of nitrates and nitrites in waters without previous concentration.[318] The reduction of these bodies by the copper-zinc couple formed the basis of these experiments, and they resulted in the following method of manipulation, which is based on a process devised by Williams.[319] The method consists in boiling rapidly one liter of the rain water in a retort, with a little magnesia previously raised to a low red heat and then washed, until 250 cubic centimeters have distilled over. The residue is then made up to 800 cubic centimeters, transferred to a wide-mouthed, stoppered bottle supplied with strips of copper and zinc forming electric couples, and set aside, at a constant temperature of from 21°–24°, for three days. A measured portion of the solution is then distilled, and the ammonia determined in the distillate by nesslerizing. This plan has two advantages: First, the ammonia, as well as the nitrogen as nitrates and nitrites, can be determined in the course of the same operation and in the same sample of water. For this purpose it is only necessary to fit the retort to an efficient condenser and to remove all ammonia from the apparatus by boiling distilled water in the retort before introducing the rain water. The distillate of 250 cubic centimeters from the rain water, as described above, is well mixed and the ammonia determined, in from twenty-five to one hundred cubic centimeters thereof, diluted to 150 cubic centimeters with ammonia-free water. Second, the nitrogen, as nitrates and nitrites, is determined directly and alone; the error of the determination is as small as nesslerizing admits of, since it is possible, if necessary, to distill 600 cubic centimeters of the boiled rain water corresponding to 750 cubic centimeters of the original, and thus obtain a full amount of ammonia for determination, even when the rain water has been poor in nitrates. The determination of nitric nitrogen, in a given sample, by the above method gave a mean quantity of product of 0.162 part per million, while the determination, in the same lot of samples, by the modified Schloesing method gave 0.125 part per million. This result confirms the supposition that in the complete evaporation necessary to the manipulation of the Schloesing method there is a loss of nitrogen. The amount of nitrogen as nitrates and nitrites in the rain water at Rothamstead, for the twelve months ending April 1, 1888, was found, by the Schloesing method, to be 0.614 pound per acre, the total rain-fall being 21.96 inches. For the year ending April 1, 1889, by the copper-zinc method, it amounted to 0.917 pound per acre, the total rain-fall being 29.27 inches. The amounts found in other localities are quite different from the above, as for instance, the mean of seven stations in Germany for thirteen years, beginning in 1864, showed 10.18 pounds of nitrogen per acre. The average amount for ten years at the observatory of Mont Sauris, near Paris, showed 12.36 pounds of nitrogen per acre. The average for three years at Lincoln, as determined by Professor G. Gray, shows one and six-tenths pounds of nitrogen per acre per annum. At Tokio, in Japan, Kellner found, for one year, 1.02 pounds per acre. =490. Determination of the Ammonia.=—The method used at Rothamstead is to make one determination of ammonia in the whole of the distillate obtained, the strength of which is regulated by varying the amount introduced into the retort, so that it shall be equal to about two cubic centimeters of the standard ammonia solution. A 150 cubic centimeter cylinder is first filled with the rain water, and fifty cubic centimeters of nessler reagent added. The depth of tint indicates what quantity of rain water will be required for distillation. This having been determined, the appropriate volume of the rain water, provided it do not exceed 600 cubic centimeters, is placed in the retort described above, and the distillation continued until the 150 cubic centimeter cylinder is filled. The titration is made in the usual way. =491. Preparation of the Copper-Zinc Couple.=—For 800 cubic centimeters of boiled rain water, prepared as described, six strips of zinc foil, four inches long by one and a quarter inches wide, are taken and bent at right angles along their center to obtain stiffness. The couple is cleansed and coated by washing in a series of five beakers containing, respectively, dilute solution of sodium hydroxid, very dilute sulfuric acid, a three per cent solution of copper sulfate, ordinary distilled water, and distilled water free from ammonia. Through these five beakers the zinc foil is successively passed. It is rinsed both after the alkali and the acid. But after the copper has been deposited, the strips are simply drained and carefully placed in the distilled water, it being difficult to rinse without removing the copper. The couples should be entirely submerged when placed in the rain water. The strips should remain in the copper sulfate solution long enough to be well covered with copper. =492. Substitution of an Aluminum-Mercury Couple for Copper-Zinc.=—Ormandy and Cohen have proposed to use an aluminum-mercury couple for the copper-zinc in the process described above.[320] This couple acts more quickly than the copper-zinc, and the results are equally as accurate. Nitrites are reduced in about one hour by this apparatus, while the zinc-copper couple of Gladstone and Tribe requires about six times as long. Aluminum foil, free of grease, should be used. The foil should be heated over a bunsen just before amalgamation. The clean, very thin foil is coated with mercury by shaking with a concentrated solution of mercuric chlorid. It should be prepared immediately before use. The amalgamated foil is introduced into the sample of water to be analyzed, and left until all the aluminum is converted into oxid. The presence of the oxid favors the prevention of bumping during the subsequent distillation. The distilled ammonia, collected in dilute acid, is determined by nesslerizing, the free ammonia in the sample having been previously determined. The increase in ammonia is due to nitrates or nitrites reduced by the couple. IODOMETRIC ESTIMATION OF NITRIC ACID IN NITRATES. =493. Method of De Koninck and Nihoul.=—This process is applicable only in the absence of organic bodies and other reducing agents. The principle on which it rests, as applied by McGowan, is as follows:[321] When a fairly concentrated solution of a nitrate is warmed with an excess of pure, strong hydrochloric acid, the nitrate is completely decomposed, and the production of nitrosyl chlorid and chlorin is quantitative. The reaction, as shown by Tilden, is represented by the following equation:[322] HNO₃ + 3HCl = NOCl + Cl₂ + 2H₂O. One molecule of nitric acid thus yields two atoms of chlorin and one molecule of nitrosyl chlorid capable of setting free three atoms of iodin. The iodin can be estimated in the usual manner by titration with sodium thiosulfate. The nitrosyl chlorid is decomposed by the potassium iodid, nitric oxid escaping. The apparatus employed is shown in Fig. 87. A is a small, round-bottomed flask, into the neck of which a glass stopper, _x_, is accurately ground (with fine emery and oil). The capacity of the bulb is about forty-six cubic centimeters, and the length of the neck, from _x_ to _y_, ninety millimeters. The first condenser is a simple tube, slightly enlarged at the foot into two small bulbs.[323] The length from _a_ to _b_ is 300 millimeters, from _b_ to _c_ 180 millimeters, and from _e_ to _f_ thirty millimeters. The capacity of the bulb B is twenty-five cubic centimeters, and the total capacity of the two bulbs and tube, up to the top of C, forty-one cubic centimeters. This condenser is immersed, up to the level of _c_, in a beaker full of water. D is a geissler bulb apparatus, E is a calcium chlorid tube, filled with broken glass, which acts as a tower and _g_ is a small funnel, attached by rubber and clip to the branch =⟙= tube _h_. Between the =⟙= tube _i_ and the wash-bottle for the carbon dioxid is placed a short piece of glass tubing, _s_, containing a strip of filter paper, slightly moistened with iodid of starch solution. This tube _s_ is really hardly necessary, as no chlorin escapes backwards if a moderate current of carbon dioxid is kept passing, but it serves as a check. A glance at the joints _o_, _p_, and _q_, which are of narrow india-rubber tubing, is sufficient to show that, by using this arrangement, practically no rubber is exposed to the action of the chlorin. The tiny piece of rubber tubing at the joint _o_ may be done away with, the narrower tube there being accurately ground into the wider one; this makes the condensing apparatus practically perfect. FIGURE 87. MCGOWAN’S APPARATUS FOR THE IODOMETRIC ESTIMATION OF NITRIC ACID. ] The actual operation is performed in the following manner: The evolution flask is washed and thoroughly dried, and the nitrate (say, about 0.25 gram of potassium nitrate) is tapped into it from the weighing tube. Two cubic centimeters of water are now added, and the bulb is gently warmed, so as to bring the nitrate into solution, after which the stopper of the flask is firmly inserted. About fifteen cubic centimeters of a solution of potassium iodid (one in four) are run into the first condensing tube, any iodid adhering to the upper portion of the tube being washed down with a little water, and five cubic centimeters of the same solution, mixed with eight to ten cubic centimeters of water, are sucked into the geissler bulbs whilst the glass in the tower E is also thoroughly moistened with the iodid. The geissler bulbs should be so arranged that gas only bubbles through the last of them, the liquid in the others remaining quiescent. All the joints having been made tight the carbon dioxid is turned on briskly and passed through the apparatus until a small tubeful collected at _l_, over caustic potash solution, shows that no appreciable amount of air is left in it. The small outlet tube _l_, is now replaced by a calcium chlorid tube, filled with broken glass which has been moistened with the above-mentioned iodid solution, and closed by a cork through which an outlet tube passes, the object of this trap tube being to prevent any air getting back into the apparatus. The brisk current of carbon dioxid is continued for a minute or two longer, so as to practically expel all the air from this last tube. The stream of gas is now stopped for an instant, and about fifteen cubic centimeters of pure concentrated hydrochloric acid, free from chlorin, run into A through the funnel _g_ (into the tube of which it is well to have run a few drops of water before beginning to expel the air from the apparatus), and A is shaken so as to mix its contents thoroughly. A slow current of carbon dioxid is now again turned on (one to two bubbles through the wash-bottle per second), and A is gently warmed over a burner. It is a distinct advantage that the reaction does not begin until the mixed solutions are warmed, when the liquid becomes orange-colored, the color again disappearing after the nitrosyl chlorid and chlorin have been expelled. The warming should be very gentle at first in order to make sure of the conversion of all the nitric acid, and also because the first escaping vapors are relatively very rich in chlorin; afterwards the liquid in A is briskly boiled. A very little practice enables the operator to judge as to the proper rate of warming. When the volume of liquid in A has been reduced to about seven cubic centimeters (by which time it is again colorless) the stream of carbon dioxid is slightly quickened and the apparatus allowed to cool a little. The burner is now set aside for a few minutes, and two cubic centimeters more of hydrochloric acid, previously warmed in a test-tube, run in gently through _g_; there is no fear either of the iodid solution running back, or of any bubbles of air escaping through _y_ if this is done carefully. This is a precautionary measure, in case a trace of the liberated chlorin might have lodged in the comparatively cool liquid in the tube _h_. The carbon dioxid is once more turned on slowly and the liquid in A is boiled again until it is reduced to about five cubic centimeters. It is now only necessary to allow the apparatus to cool, passing carbon dioxid all the time, after which the contents of the condensers are transferred to a flask and titrated with thiosulfate. At the end of a properly conducted experiment, the glass in the upper part of tower E should be quite colorless and there should be only a mere trace of iodin showing in the lower part of the tower, while the liquid in the last bulb of the geissler apparatus ought to be pale yellow. During the operation, the stopper of A and the various joints can be tested from time to time by means of a piece of iodid of starch paper, and before disjointing it is well to test the escaping gas (say at _m_) in the same way, to make sure that all nitric oxid has been thoroughly expelled. The method is capable of giving accurate results, but it can not be preferred to the reduction or colorimetric processes. =494. Method of Gooch and Gruener.=—The principle on which this method rests depends on the decomposition of a nitrate in presence of a hot saturated solution of manganous chlorid and hydrochloric acid in an atmosphere of carbon dioxid.[324] The products of decomposition are passed into a solution of potassium iodid and the liberated iodin is titrated with standard sodium thiosulfate. The products of the reaction are chlorin, nitric oxid, and possibly nitrosyl chlorid, and under proper precautions the iodin set free is quantitively proportional to the weight of nitrate decomposed. The manganous mixture is acted on slowly at ordinary temperatures, but on heating, the nitrate is decomposed with the formation of a higher manganese chlorid and nitric oxid. When the heat is continued a sufficient length of time the chlorin from the higher chlorids is evolved and only manganous chlorid remains. During the heating the color of the solution passes from green to black and at the end the green color is restored. The apparatus employed is shown in Fig. 88. FIGURE 88. APPARATUS OF GOOCH AND GRUENER. ] A plain pipette bent as is shown in the figure serves as the generating flask and for the attachment on the one hand to the carbon dioxid apparatus and on the other to the system of absorption bulbs for containing the potassium iodid. The latter should be glass, sealed to the evolution bulb of the pipette to prevent the action of the evolved gases on organic materials. The point of the potassium iodid apparatus is drawn out so as to be pushed well into the second receiver, being held in place by a piece of rubber tubing. The third tube acts simply as a trap to exclude the air from the absorption apparatus. The first receiver contains in solution three grams, the second two, and the third one gram of potassium iodid. During the reaction the first receiver is kept cool by immersion in water. Before connecting the apparatus with the carbon dioxid generator the solution of manganous chlorid and afterwards the nitrate solution are drawn into the bulb of the pipette by gentle suction. After connecting the apparatus the current of carbon dioxid is started and kept up until all the air is expelled. Heat is then applied to the bulb of the pipette and the distillation continued until all the liquid has passed over. At the end of the reaction the contents of the receivers are united by disconnecting the apparatus from the carbon dioxid generator and passing water through the pipette. The introduction of the manganous chlorid into the mixture does not interfere with the titration of the iodin. This is accomplished in the usual way with sodium thiosulfate using starch as an indicator. The quantity of material used should contain about the amount of nitric acid that is found in two-tenths of a gram of potassium nitrate. This method, so similar to the preceding, is somewhat less complex, and, to that extent, preferable to it. ESTIMATION OF NITRIC ACID BY COLORIMETRIC COMPARISON. =495. Delicacy of the Method.=—The remarkable delicacy of those methods of chemical analysis, which depend on the production of a pronounced color, which can be compared with that produced by a known quantity of a given substance, has been long illustrated by the nesslerizing process for the estimation of ammonia. By such methods minute qualities of substances can be quantitively determined with great accuracy, when they would escape all effort for their estimation by gravimetric methods. Processes based on this principle are, therefore, peculiarly applicable to the detection and estimation of oxidized nitrogen in waters and soil extracts, whether they be present as nitric, nitrous, or ammoniacal compounds. In the following paragraphs will be given with sufficient detail for the needs of the analyst, the principles and practice of the colorimetric comparison methods which have been approved as best by the experience of analysts. These methods are applicable especially to cases in which only minute quantities of the substances looked for are present, and where celerity of determination is especially desirable. They are, therefore, of especial value in the analysis of rain, drainage, and irrigation waters, and of soil extracts poor in oxidized nitrogen. =496. Hooker’s Method.=—The quantitive action depends upon the deep green coloration given by nitric acid, when dissolved in sulfuric acid and carbazol.[325] Other oxidizing bodies, such as iron, chlorin, bromin, chromic acid, etc., give the same reaction, but not in such a prominent manner. Such bodies with the exception of chlorin and iron, are not often found in waters. In the application of the process, iron, if present in quantities greater than one-tenth part per one hundred thousand, must be removed. Chlorids also, even when present in very small quantities, interfere with the delicacy of the reaction and must be removed. Easily destructible organic matter tends to lower the result, but not materially, unless present in large excess. Calcium carbonate and sulfate, soda, and other alkalies, in the quantities in which they are usually present in water, do not affect the result. The following reagents are required: 1. Concentrated sulfuric acid. 2. An acetic acid solution of carbazol; diphenylimid, (C₆H₄\/C₆H₄/ NH.) 3. A sulfuric acid solution of carbazol. 4. Standard solutions of potassium nitrate. 5. A solution of aluminum sulfate. 6. A solution of silver sulfate. 1. The sulfuric acid, used for all purposes in the process, should be entirely free from nitrogen oxids. It may be readily tested by dissolving in it a small quantity of carbazol. If the solution be at first golden-yellow or brown, the acid is sufficiently pure; if it be green or greenish, another and better sample must be taken. It is essential also that the specific gravity of the acid be fully 1.84, and it is well to ascertain that this is really the case. 2. The acetic acid solution of carbazol is prepared by dissolving six-tenths gram in about ninety cubic centimeters of strongest acetic acid, by the aid of gentle heat. It is allowed to cool, and is then made up to 100 cubic centimeters by the further addition of acetic acid. The exact strength of this solution, is of no material importance to the success of the process, and the above proportions have been selected principally because they are convenient. The solution will remain unchanged for several months. The use of this solution merely facilitates the preparation of that next described, which will not keep, and has, consequently, to be freshly prepared for each series of determinations. 3. The sulfuric acid solution of carbazol is easily made in a few seconds, but it is advisable to allow it to stand from one and one-half to two hours before using. It is prepared by rapidly adding fifteen cubic centimeters of sulfuric acid, to one cubic centimeter of the above-described acetic acid solution. This quantity usually suffices for from two to three nitrate estimations. When freshly prepared it is golden-yellow or brown; it changes gradually, however, and in the course of one and one-half or two hours it becomes olive-green. This change is probably due to traces of oxidizing agents, which occur in the sulfuric and acetic acids, and which, although not present in sufficient quantity to act immediately, gradually bring about the reaction described. The greenish color does not interfere with the process, as might at first be supposed; on the contrary, the solution is not sensitive to small quantities of nitric acid until it has undergone the change to olive-green, and it is for this reason, that it should be prepared about two hours before required for use. This solution may be thoroughly depended on for six hours after preparation. The intensities of color produced by the more concentrated solutions of nitrates after this time, gradually approach each other and become ultimately the same. 4. The standard solutions of potassium nitrate are very readily prepared. The solutions which are to be compared directly with the waters examined, may be prepared as required, but if many determinations are to be made with a variety of waters, it will be found best to prepare a complete series, differing from each other by 0.02 part nitrogen in 100,000. This series may include solutions containing quantities of nitrogen in 100,000 parts, represented by all the odd numbers from 0.03 up to 0.39. It will be found convenient to prepare them in quantities of 100 cubic centimeters at a time, from a stock solution of potassium nitrate which contains 0.00001 gram nitrogen, or 0.000045 nitric acid in one cubic centimeter. Each cubic centimeter of this solution, when diluted to 100 cubic centimeters, represents 0.01 nitrogen in 100,000, and consequently if it is desired to make a solution containing 0.35 part nitrogen in 100,000, thirty-five cubic centimeters are taken and made up to 100 cubic centimeters, and so on. The solution of potassium nitrate (b) is best prepared from a stronger one (a) containing 0.0001 gram nitrogen to the cubic centimeter, or 0.7214 gram potassium nitrate to the liter; 100 cubic centimeters of (a) made up to one liter give the solution (b). It is obvious that the series of solutions, above described, could be made directly from (a), but by first making (b), greater accuracy is secured. 5. For purposes which will be presently described, a solution of aluminum sulfate is required, containing five grams to the liter. The salt used must be free from chlorin and iron; and the solution should give no reaction when tested with carbazol. 6. The solution of silver sulfate is required for the removal of chlorin from the water or soil extract to be examined. It is prepared by dissolving 4.3943 grams of the salt in pure distilled water and making up to one liter. The sulfate is preferably obtained by dissolving metallic silver in pure sulfuric acid. The solution should be tested with carbazol in the same way as will be presently described for water; if perfectly pure, no reaction will be obtained. As silver sulfate is often prepared by precipitation from the nitrate, it is very apt to contain nitric acid, and consequently, if the source of the salt be unknown, this test should on no account be omitted. The analytical process is carried on as follows: Two cubic centimeters of the water are carefully delivered by means of a pipette into the bottom of a test-tube; four cubic centimeters of sulfuric acid are added, and the solution thoroughly mixed by the help of a glass rod. The test-tube is then immersed in cold water, and when well cooled, one cubic centimeter of the sulfuric acid solution of carbazol is added, and the whole again mixed as before. The intensity of the color is now observed, and a little experience enables a fairly good opinion to be formed of the quantity of nitric acid present. Suppose that the water be roughly estimated to contain about 0.15 part nitrogen per 100,000; in such a case solutions of potassium nitrate containing 0.11, 0.15, 0.19 part nitrogen are selected from the series. Two cubic centimeters are taken from each, and treated, side by side, with a fresh quantity of the water, precisely as described for the preliminary experiment, the various operations being performed as nearly simultaneously as possible with each of the samples, and under precisely similar conditions. Two or three minutes after the carbazol has been added, the intensity of the color of each is observed. If that given by the water is matched by any of the standard solutions, the estimation is at an end. Similarly, if it falls between two of these, the mean may be taken as representing the nitrogen present in cases in which great accuracy is not required. If this be done, the maximum error will be 0.02 part nitrogen, or 0.09 part nitric acid per 100,000. If greater exactness be required, or it be found that the color given by the water is either darker or lighter than that given by all the standard solutions, a new trial must be made. In such a case the water must be again tested simultaneously with the solutions with which it is to be compared. This is rendered necessary principally for the reason that the shade of the solutions to which the carbazol has been added is apt to change on standing. Hence it is desirable that the water, and the standard potassium nitrate with which it is to be compared, should have the carbazol added at as nearly the same time as possible. When finally the color falls between that given by any two consecutive members of the standard potassium nitrate series, the estimation may be considered at an end, and the mean of these solutions taken as representing the nitrogen present. The greatest neatness should be observed in all steps of the analysis. The quantity of water operated upon is so small that if the greatest care be not exercised throughout, sources of error may be readily introduced. The test-tubes should be rinsed out with nitrate-free water before being used and then dried. The tint should be determined by looking through the tube and not through the length of the column of liquid. _Influence of Nitrites._—If the quantity of nitrous acid in the water is known a correction can be applied for nitrates by deducting one-fifth of the number found for nitrites when estimated as nitrates. _Influence of Iron._—Although ferrous salts give no reaction with carbazol, nitrates are apt to be overestimated in their presence. Oh the other hand, ferric compounds, like other oxidizing agents, may give a characteristic green color with carbazol. In all cases when iron is present in any considerable quantity it is best to remove it by rendering the water slightly alkaline, evaporating to dryness, and redissolving the soluble residue until the solution reaches the original volume. _Influence of Chlorids._—The presence of chlorids furnishes by far the most serious source of error in the process by intensifying the action of the nitric acid. If, however, nitrates be absent chlorids give no reaction with carbazol. The chlorids are removed by a standard silver sulfate solution, the quantity of chlorids present having been first determined by a standard silver nitrate solution. For this purpose an ordinary sugar flask can be employed marked at 100 and 110 cubic centimeters. This flask is filled to the 100 cubic centimeter mark with the water to be examined; the necessary quantity of silver sulfate is added and then two cubic centimeters of the solution of aluminum sulfate, previously described, and the contents of the flask brought up to 110 cubic centimeters by the addition of pure distilled water. The whole is shaken up and filtered, the first portion of the filtrate being rejected. The aluminum sulfate by reacting with the carbonates usually present in the water and producing the precipitation of alumina, facilitates the removal of the precipitated silver chlorid. The above-described method on account of its delicacy is not well suited to aqueous solutions of soils except where the quantity of nitric nitrogen present is extremely minute. Hooker also first suggested the use of diphenylamin for detecting the presence of nitrates,[326] a method afterwards worked out by Spiegel.[327] In the variation of the method as practiced by Rideal the standard potassium nitrate and the pure sulfuric acid mentioned below are required, and in addition, the following reagents:[328] (a) Silver sulfate solution containing 4.3945 grams per liter. (b) Aluminum sulfate solution free from chlorids and iron, five grams per liter. (c) Carbazol solution; six-tenths gram carbazol dissolved in glacial acetic acid and made up to 100 cubic centimeters with the glacial acid. For use, one cubic centimeter of this solution is withdrawn by a pipette and mixed with fifteen cubic centimeters of pure redistilled sulfuric acid. The process is carried out as follows: To 100 cubic centimeters of water the amount of chlorin which has been previously ascertained is removed by the silver sulfate solution. Two cubic centimeters of the aluminum sulfate are added and the whole made up to a convenient volume, say about 110 cubic centimeters. The liquid is filtered and two cubic centimeters of the filtrate taken for an estimation of nitrates. To the two cubic centimeters are added four cubic centimeters of concentrated sulfuric acid and the mixture cooled. One cubic centimeter of the carbazol solution in sulfuric acid is added and a bright green color appears in a few moments, if nitrates are present. Comparison is made with solutions of standard potassium nitrate. =497. Phenylsulfuric Acid Method.=—Rideal also proposes a variation of the method described by Hooker, which consists in the substitution of phenylsulfuric acid for carbazol.[329] The solutions required are: (a) A standard solution of potassium nitrate containing 0.7215 gram of the pure crystallized salt in a liter of water. (b) Phenylsulfuric acid, (acid phenyl sulfate,) prepared by dissolving fifteen grams of pure crystallized phenol in 92.5 cubic centimeters of pure, redistilled sulfuric acid free from nitrates and diluted with seven and one-half cubic centimeters of water. The process is conducted as follows: A known volume of water, from twenty-five to one hundred cubic centimeters, according to its richness in nitrates, is evaporated to dryness in a porcelain dish, one cubic centimeter of phenylsulfuric acid added then one cubic centimeter of pure water and three drops of strong sulfuric acid and the mixture gently warmed. A yellow color shows the presence of nitrates. Dilute to about twenty-five cubic centimeters with water and add ammonia in slight excess. Pour into a narrow nessler tube and add the washings and make up to 100 cubic centimeters. Imitate the color of the solution with the standard potassium nitrate treated with the same reagents. The phenylsulfuric acid should be prepared some time before use, as the fresh solution imparts a greenish tint to the yellow of the ammonium picrate formed. =498. Variation of Leffmann and Beam.=—The phenyl sulfate process, as described by Leffmann and Beam, is conducted as follows:[330] _Solutions Required._—_Acid phenyl sulfate_: 18.5 cubic centimeters of strong sulfuric acid are added to one and one-half cubic centimeters of water and three grams of pure phenol. Preserve in a tightly-stoppered bottle. _Standard potassium nitrate_: 0.722 gram of potassium nitrate, previously heated to a temperature just sufficient to fuse it, is dissolved in water, and the solution made up to 1000 cubic centimeters. One cubic centimeter of this solution will contain 0.0001 gram of nitrogen. _Analytical Process._—A measured volume of the water is evaporated just to dryness in a platinum or porcelain basin. One cubic centimeter of the acid phenyl sulfate is added and thoroughly mixed with the residue by means of a glass rod. One cubic centimeter of water, and three drops of strong sulfuric acid are added, and the dish gently warmed. The liquid is then diluted with about twenty-five cubic centimeters of water, ammonium hydroxid added in excess, and the solution made up to 100 cubic centimeters. The reactions are: Acid phenyl sulfate. Trinitrophenol (picric acid). HC₆H₅SO₄ + 3HNO₃ = HC₆H₂(NO₂)₃O + H₂SO₄ + 2H₂O. Ammonium picrate. HC₆H₂(NO₂)₃O + NH₄HO = NH₄C₆H₂(NO₂)₃O + H₂O. The ammonium picrate imparts to the solution a yellow color, the intensity of which is proportional to the amount present. Five cubic centimeters of the standard solution of potassium nitrate are similarly evaporated in a platinum dish, treated as above, and made up to 100 cubic centimeters. The color produced is compared to that given by the water, and one or the other of the solutions diluted until the tints of the two agree. The comparative volumes of the liquids furnish the necessary data for determining the amount of nitrate present, as the following example will show: Five cubic centimeters of standard nitrate are treated as above, and made up to 100 cubic centimeters, representing 0.0005 gram nitrogen. Suppose 100 cubic centimeters of water similarly treated are found to require dilution to 150 cubic centimeters before the tint will match that of the standard; then 100 : 150 :: 0.005 : 0.0075 _i. e._, the water contains seven and one-half milligrams of nitrogen as nitrate per liter. The ammonium picrate solution keeps very well, especially in the dark. A good plan, therefore, is to make up a standard solution equivalent to, say, ten milligrams of nitrogen as nitrate per liter, to which the color obtained from the water may be directly compared. The results obtained by this method are quite accurate. Care should be taken that the same quantity of acid phenyl sulfate be used for the water and for the comparison liquid, otherwise different tints instead of depths of tints are produced. With subsoil and other waters probably containing much nitrates, ten cubic centimeters of the sample will be sufficient for the test, but with river and spring waters, twenty-five to one hundred cubic centimeters may be used. When the organic matter is sufficient to color the residue, it will be well to purify the water by addition of alum and subsequent filtration, before evaporating. The method may also be used to determine small quantities of nitrates in aqueous extracts of soils when the quantity is too small for estimation by the ferrous chlorid or reduction processes. =499. Variation of Johnson.=—The ammonium picrate method has given very satisfactory results as practiced by Johnson, who varies the process as described below.[331] The standard solution of potassium nitrate is prepared by dissolving 0.7215 gram of the pure salt in a liter of distilled water. Dilute 100 cubic centimeters of this solution to one liter with distilled water. Ten cubic centimeters of this dilute solution contain nitrogen equivalent to one part as nitrates in 100,000. _The Solution of Acid Phenyl Sulfate._—This is prepared by pouring two parts by measure of pure crystallized phenol liquefied by hot water into five parts by measure of pure concentrated sulfuric acid and digesting the whole in the water-bath for eight hours. After cooling, add one and one-half volumes of distilled water and one-half volume strong hydrochloric acid to each volume of the above mixture. The analytical processes are carried on as follows: Ten cubic centimeters of the water under examination and ten cubic centimeters of the standard potassium nitrate are placed in small beakers and put near the edge of a hot plate. When nearly evaporated they are put on the top of the water-bath and left there until completely dry. The residue, in each case, is then treated with one cubic centimeter of the acid phenyl sulfate and the beakers placed on the top of the water-bath. In good water, a red color ought not to appear for about ten minutes. After standing about fifteen minutes, the beakers are removed, the contents of each washed successively into 100 cubic centimeter flasks, about twenty cubic centimeters of 0.96 per cent. ammonia added, and the 100 cubic centimeters made up by the addition of water and the yellow liquid transferred to the nessler glass and the tints appropriately compared. =500. Estimation of Nitric in Presence of Nitrous Acid.=—The detection of nitrous in presence of nitric acid can be accomplished by the method proposed by Griess, as described further on, through the development of azocolors, with metaphenylenediamin and other bodies, which are not produced under similar conditions by nitric acid. The detection and estimation of nitric in the presence of nitrous acid, however, is not so easy. Lunge and Lwoff propose brucin for this purpose, which, contrary to most authorities, does not give the red-yellow color with nitrous acid.[332] The reagent is prepared by dissolving two-tenths gram of brucin in 100 cubic centimeters of sulfuric acid, pure and concentrated. It is almost impossible to prepare a sulfuric acid which does not give a trace of color with brucin; but with the purest acids this trace may be neglected. A solution of nitrate is also prepared containing 0.01 milligram of nitrogen as nitric acid in one cubic centimeter. It is made by dissolving 0.0721 gram of pure potassium nitrate in 100 cubic centimeters of distilled water, and diluting ten cubic centimeters thereof with pure concentrated sulfuric acid to 100 cubic centimeters. Both solutions are conveniently preserved in burettes with glass stop-cocks. The liquid to be tested for nitric acid should be mixed with sulfuric acid in such a way that the mixture will have a specific gravity of one and seven-tenths. If the liquid to be tested is water, this concentration is reached by adding three times its volume of the strong acid. For the comparison of colors, cylinders of colorless glass are employed, marked at fifty cubic centimeters. They should be about twenty-four centimeters high and extend about ten centimeters above the mark. There is placed in the cylinder one cubic centimeter of the solution of nitrate in sulfuric acid, and the same quantity of the brucin mixture, and it is filled to the mark with pure sulfuric acid. The contents of the cylinder are poured into a flask and warmed at from 70°–80°, until the final yellow tint is secured, and then poured into the cylinder again. The liquid to be tested is treated in exactly the same way. The tints are then equalized by pouring out a part of the contents of the deeper colored cylinder, taking account of the volume, and filling up with pure concentrated sulfuric acid. In this manner the content of nitric acid in the liquid under examination can be compared directly with the solution of potassium nitrate of known strength. The coloration is distinctly produced with 0.01 milligram in fifty cubic centimeters of liquid, at least three-fourths of which must be sulfuric acid. =501. Piccini Process.=—The method proposed by Piccini may also be used.[333] About five cubic centimeters of the nitrite solution are placed in a small beaker, some pure urea dissolved therein and a few drops of sulfuric acid, and then held in boiling water for three minutes. The nitrous acid is thus completely destroyed. Ammonium chlorid may be substituted for urea. The reaction is given on page 478. The nitric acid present is then determined by diphenylamin or other suitable reagents. Diphenylamin reacts both with nitrous and nitric acids, producing a violet tint. Warington calls attention to a slight difference, however, in its deportment with these two acids. When the solution of the reagent is not too strong a drop of it produces but little turbidity when added to water or to a solution containing nitric acid. When, however, nitrous acid is present, a cream-colored turbidity is produced. The violet color also appears at once on adding sulfuric acid when a nitrite is present, while in the case of nitrates, more sulfuric acid is required, except when the solution is very strong. In this connection, it must not be forgotten that in heating nitrites with urea or ammonium chlorid in the presence of a slight excess of sulfuric acid a trace of nitric acid may be formed. ESTIMATION OF NITROUS ACID BY COLORIMETRIC COMPARISON. =502. Application of the Method.=—The most minute traces of nitrous acid may be detected by colorimetric methods and the determination of the quantity present may be approximated with great exactness by comparison with a solution of a nitrite of known strength. Especially in following the progress of nitrification is this method, in some of its forms, of essential importance. In delicacy and celerity it has the same advantages as the colorimetric methods for the determination of nitric acid. =503. Metaphenylenediamin Method.=—This process depends upon the development of a yellow color in water containing nitrous acid on the addition of a reagent containing metaphenylenediamin; m-C₆H₄(NH₂)₂. This variety of the phenylenediamins is readily obtained from common dinitrobenzene. It melts at 63° and boils at 287°. In order to preserve the reagent in shape for use it should be prepared in the following manner: Dissolve two grams of the chlorid in ten cubic centimeters of ammonia, and place the solution in a glass-stoppered flask. To this solution are added five grams of powdered animal-black, and the whole vigorously shaken. After allowing to settle, the shaking is repeated at intervals of an hour, three or four times, and the flask then allowed to remain at rest for twenty-four hours. The supernatant liquid is generally sufficiently decolorized by this treatment. If not, the shaking and subsidence must be repeated until a completely colorless liquid is obtained. The solution can be kept, indefinitely, in contact with the animal-black. Aqueous and alcoholic solutions of the salt can not be kept. The test is applied by mixing five drops of the reagent with five cubic centimeters of sulfuric acid. The mixture must be colorless. To the mixture add 100 cubic centimeters of the water to be tested, and heat on the water-bath for five minutes. A yellow coloration indicates the presence of nitrous acid. The metaphenylenediamin test is fairly satisfactory in perfectly colorless waters and aqueous extracts. Many waters and soil extracts, however, have a yellowish tint, and this interferes in a marked way with a proper judgment of the yellow triaminazobenzol developed in the application of the above test. The decoloration of such waters by means of sodium carbonate or hydroxid and alum, is a matter of some difficulty and not wholly without action on the nitrites which may be present. The method, therefore, is inferior to the one next described. =504. Sulfanilic Acid and Naphthylamin Test for Nitrous Acid.=—A very delicate test for the presence of nitrous acid, first described by Griess, is the coloration produced thereby in an acid solution of sulfanilic acid and naphthylamin.[334] Sulfuric or acetic acid may be used as the acidifying agent, preferably the latter. The solutions are prepared as follows: (1) Dissolve one-half gram of sulfanilic acid in 150 cubic centimeters of dilute acetic acid. (2) Boil one-tenth gram of naphthylamin with twenty cubic centimeters of water, decant the colorless solution from the residue and acidify it with 150 cubic centimeters of dilute acetic acid. The two solutions may at once be mixed and preserved in a well-stoppered flask. The action of light on the mixture is not hurtful, but air should be carefully excluded because of the traces of nitrous acid which it may contain. Whenever the mixed solutions show a red tint it is an indication that they have absorbed some nitrous acid. The red color may be discharged and the solution again fitted for use by the introduction of a little zinc dust, and shaking. The water, or aqueous solution of a soil, to be tested for nitrites, in portions of about twenty cubic centimeters, is treated with a few cubic centimeters of the mixed reagent and warmed to 70°–80°. If nitrous acid, in the proportion of one part to one million be present, the red color will appear in a few minutes. If the content of nitrous acid be greater, _e. g._, one part in one thousand, only a yellow color will be produced, unless a greater quantity of the reagent be used. Leffmann and Beam recommend the following method of conducting the determinations.[335] Solutions required: _Naphthylammonium Chlorid._—Saturated solution in water free from nitrites. It should be colorless; a small quantity of animal charcoal allowed to remain in the bottle will keep it in this condition. _Paraamidobenzene Sulfonic Acid (Sulfanilic Acid)._—Saturated solution in water, free from nitrites. _Hydrochloric Acid._—Twenty-five cubic centimeters of concentrated pure hydrochloric acid added to seventy-five cubic centimeters of water, free from nitrites. _Standard Sodium Nitrite._—0.275 gram pure silver nitrite is dissolved in pure water, and a dilute solution of pure sodium chlorid added until the precipitate ceases to form. It is then diluted with pure water to 250 cubic centimeters and allowed to stand until clear. For use, ten cubic centimeters of this solution are diluted to 100. It is to be kept in the dark. One cubic centimeter of the dilute solution is equivalent to 0.00001 gram of nitrogen. The silver nitrite is prepared in the following manner: A hot concentrated solution of silver nitrate is added to a concentrated solution of the purest sodium or potassium nitrite available, filtered while hot and allowed to cool. The silver nitrite will separate in fine needle-like crystals, which are freed from the mother-liquor by filtration with the aid of a filter pump. The crystals are dissolved in the smallest possible quantity of hot water, allowed to cool and crystallize, and again separated by means of the pump. They are then thoroughly dried in the water-bath, and preserved in a tightly-stoppered bottle away from the light. Their purity may be tested by heating a weighed quantity to redness in a tared, porcelain crucible and noting the weight of the metallic silver. One hundred and fifty-four parts of silver nitrite leave a residue of 108 parts of silver. _Analytical Process._—One hundred cubic centimeters of the water are placed in one of the color-comparison cylinders, the measuring vessel and cylinder having previously been rinsed with the water to be tested. By means of a pipette, one cubic centimeter each of the solutions of sulfanilic acid, dilute hydrochloric acid, and naphthylammonium chlorid is dropped into the water in the order named. It is convenient to have three pipettes for this test, and to use them for no other purpose. In any case the pipette must be rinsed out thoroughly with nitrite-free water each time before using, as nitrites, in quantity sufficient to give a distinct reaction, may be taken up from the air. One cubic centimeter of the standard nitrite solution is placed in another clean cylinder, made up with nitrite-free water to 100 cubic centimeters and treated with the reagents, as above. In the presence of nitrites a pink color is produced, which, in dilute solutions, may require half an hour for complete development. At the end of this time the two solutions are compared, the colors equalized by diluting the darker, and the calculation made as explained under the estimation of nitrates. The following are the reactions: Paraamidobenzene Nitrous acid. Paradiazobenzene sulfonic acid. sulfonic acid. C₆H₄NH₂HSO₃ + HNO₂ = C₆H₄N₂SO₃ + 2H₂O. Naphthylammonium Azoalphaamidonaphthalene parazobenzene chlorid. sulfonic acid. C₆H₄N₂SO₃ + C₁₀H₇NH₃Cl = C₁₀H₆(NH₂)NNC₆H₄HSO₃ + HCl. The last named body gives the color to the liquid. The method pursued by Tanner, in the preparation of the reagent, is as follows: Sulfanilic acid is prepared by mixing thirty grams of anilin slowly, with sixty grams of fuming sulfuric acid, in a porcelain dish. The brown, sirupy liquid formed is carefully heated until quite dark in color, and until the evolution of sulfurous fumes is noticed. After cooling, the thick, semi-fluid mass is poured into half a liter of cold water and allowed to stand for some hours. The liquid portion is then decanted from the nearly black undissolved crystalline mass. To the residue half a liter of hot water is added and allowed to stand until cold, and the liquid again decanted. The undissolved portion is then treated with one liter of hot water and filtered. The filtrate is treated with animal charcoal to decolorize it, and allowed to stand for twenty-four hours and again filtered, the filtrate diluted to 1,500 cubic centimeters and used as required. This solution tends to turn pink on keeping, and thus its color interferes with the delicacy of the test, and a small amount of animal-char is kept in a small bottle containing the portion for immediate use, and this bottle is filled, from time to time, from the larger one. The solution of naphthylamin hydrochlorate is made with one gram of the salt dissolved in 100 cubic centimeters of water. The solution is to be occasionally filtered, and not more than 100 cubic centimeters should be prepared at a time. The analytical operations are carried on as follows: A standard solution of pure potassium nitrite, made from the silver salt in distilled water perfectly free from nitrites, is placed in a color-glass, similar to those used in the nessler reaction, together with a second glass containing the water to be tested. These glasses should be marked to hold 100 cubic centimeters at the same depth. To each of the tubes a few drops of pure hydrochloric acid are added and two cubic centimeters of the sulfanilic solution. Afterwards, to each tube are added two cubic centimeters of the solution of naphthylamin hydrochlorate, and it is allowed to stand for twenty minutes, at the end of which time the color should be fully developed. Each tube is covered by a piece of glass in order to prevent access of air. It is unnecessary to add that the standard solutions of nitrite of different strength should be employed until the one is found which resembles, as nearly as possible, the color developed in the sample of water under examination. =505. Lunge and Lwoff’s Process for Nitrous Acid.=—The reaction of nitrous acid with α naphthylamin, first described by Griess, may be made reliable, quantitatively, by proceeding as below:[336] Boil 0.100 gram of pure white α naphthylamin for fifteen minutes with 100 cubic centimeters of water, add five cubic centimeters of glacial acetic acid, or its equivalent of dilute acid, and afterwards one gram of sulfanilic acid dissolved in 100 cubic centimeters of hot water. The mixture is kept in a well-closed flask. A slight red tint in the mixture is of no significance, inasmuch as this completely disappears when one part of it is mixed with fifty parts of the liquid to be examined. If the coloration be very strong it can be removed by adding a little zinc dust. One cubic centimeter of this reagent will give a distinct coloration with 0.001 milligram of nitrous nitrogen in 100 cubic centimeters of water. The analysis is conducted in cylinders of white glass marked at fifty cubic centimeters. One cubic centimeter of the above reagent is placed in each of two cylinders with forty cubic centimeters of water and five grams of solid sodium acetate. In one of the cylinders is placed one cubic centimeter of a normal solution of a nitrite prepared by dissolving 0.0493 gram of pure sodium nitrite corresponding to ten milligrams of nitrogen in 100 cubic centimeters of water, and adding ten cubic centimeters of this solution to ninety cubic centimeters of pure sulfuric acid. This secures a normal solution of nitrosylsulfuric acid, of which each cubic centimeter corresponds to 0.01 milligram of nitrogen. In the other cylinder is placed one cubic centimeter of the solution to be examined, and the contents of both cylinders are well mixed so that the nitrous acid in a nascent state may act on the reagent. The colors are compared after any convenient period, but, as a rule, after five minutes. The chief improvement made by Lunge and Lwoff on the method of Griess is in keeping the reagent in a mixed state ready for use, by means of which any nitrous impurities in the components thereof are surely indicated. Its advantage over the method of Ilosvay[337] consists in using the comparative normal nitrite solution as nitrosylsulfuric acid, in which state it is much more stable. =506. Estimation of Nitrous Acid with Starch as Indicator.=—The method of procedure, depending on the blue color produced in a solution of starch in presence of a nitrite and zinc iodid when treated with sulfuric acid, is not of wide application on account of the interference produced by organic matter. The soil extract or water is treated in a test-tube, with a few drops of starch solution and some zinc iodid, to which is added some sulfuric acid. The decomposition of the nitrite is attended with the setting free of an equivalent amount of iodin which gives a blue coloration to the starch solution. The depth of the tint is imitated by treating a standard solution of nitrite in a similar way until the proper quantity is found, which gives at once the proportion of nitrite in the sample examined. This process, however, is scarcely more than a qualitative one. =507. Estimation of Nitrites by the Method of Chabrier.=—In order to make the estimation of the evolved nitrous acid more definite by the iodin method, Chabrier has elaborated a plan for titrating it with a reducing agent.[338] The substance chosen for this purpose is sodium hyposulfite. In point of fact, it is not the nitrous acid which is attacked by the hyposulfite, but the equivalent amount of free iodin representing it. In the case of a soil where the quantity of nitrites is usually very small, it is well to take as much as one kilogram. The extraction should be made rapidly, with water, free of nitrites, in order to avoid any reducing action on the nitrates which may be present. In the case of water, from five to ten liters should be evaporated to a small volume. The concentration should take place in a large flask, rather than in an open dish, in order to avoid any possibility of the absorption of nitrites produced by combustion. When the volume has been reduced to about 100 cubic centimeters it is transferred to a small flask and the concentration continued until only ten or fifteen cubic centimeters are left. The residue is filtered into a woulff bottle, F, Fig. 89, of about 100 cubic centimeters capacity. One of the side tubulures carries a burette, B, containing five per cent sulfuric acid, the other one filled with a hyposulfite solution of known strength. The middle tubule serves to introduce a glass tube through which carbon dioxid or illuminating gas passes for the purpose of driving out the air from the solution and the flask. If carbon dioxid be used it should be generated by the action of sulfuric acid on marble. The cork holding this is furnished with a slot or valve to permit the exit of the air and the excess of the gas. Before inserting the middle stopper, a few cubic centimeters of potassium iodid solution and a few drops of thin starch paste are added, the potassium salt being always used in excess of the nitrite supposed to be present. FIGURE 89. METHOD OF CHABRIER. ] After the air has all been expelled from the flask the analytical process is commenced, the carbon dioxid current being slowly continued. At first, a few drops of the dilute sulfuric acid are allowed to flow into the flask. As soon as the liquid is colored blue a sufficient quantity of the thiosulfate solution is added to discharge the color. The successive addition of acid and thiosulfate is continued until another portion of the acid fails to develop the blue color, thus indicating that all the nitrite has been decomposed. From the volume of thiosulfate used the quantity of nitrite is calculated. _The Thiosulfate Solution._—The thiosulfate solution is conveniently prepared, when a large number of analyses is to be made, by dissolving twenty-five grams of pure crystallized sodium thiosulfate in 100 cubic centimeters of water and diluting any convenient part thereof to 100 or 1,000 cubic centimeters, according to the supposed strength of nitrite solution under examination. For fixing the strength of the solution dissolve 3 348 grams of pure iodin in a solution of potassium iodid and make the volume up to one liter. Each cubic centimeter of this solution corresponds to one milligram of nitrous acid. A given volume of the iodin solution is titrated against the thiosulfate, but it is best not to add the starch paste until the greater part of the iodin has been removed. The starch paste is then added and the titration continued until the blue color has been discharged. Ten cubic centimeters of the iodin solution is a convenient quantity for the titration and the thiosulfate should be diluted by adding to ten cubic centimeters of the solution mentioned above, 990 cubic centimeters of water. Each liter of this dilute solution contains two and a half grams of the sodium thiosulphate. _Example._—Let us suppose that it has required 21.3 cubic centimeters of thiosulfate to absorb ten cubic centimeters of the iodin solution; further that ten liters of water have been evaporated and titrated as described above, and that the volume of thiosulfate employed was 13.8 cubic centimeters. From this is derived the following formula: (13.8 × 10)/(21.3) = 6.48 milligrams of nitrous acid; or 0.648 milligram per liter. =508. Estimation of Nitrous Acid By Coloration of Solution of Ferrous Salt.=—This method, due to Picini is based on the production of the well-known brown color formed by the action of nitric oxid on a ferrous salt.[339] The nitrite is decomposed by heating with acetic acid while nitrates thus treated do not develop the reaction. The tint produced is imitated as above by testing against a standard solution of nitrite. Ferrous chlorid is to be preferred to other ferrous salts for the above purpose. The process should be carried on in solutions free of air. =509. Estimation of Nitrous Acid By Decomposition with Potassium Ferrocyanid.=—The method of Schaeffer was first described in 1851, but little attention has been paid to it since. The method has lately been brought into notice again by Deventer.[340] The reaction depends upon the decomposition of nitrous acid by potassium ferrocyanid in the presence of acetic acid with the formation of potassium ferricyanid and acetate, and nitric oxid. The reaction is expressed by the following equation: 2K₄FeCy₆ + 2HNO₂ + 2C₂H₄O₂ = K₆Fe₂Cy₁₂ + 2KC₂H₃O₂ + 2NO + 2H₂O. FIGURE 90. SCHAEFFER’S NITROUS ACID METHOD. ] A eudiometer with a glass stop-cock is arranged as shown in Fig. 90. The lower part of the eudiometer is closed with a rubber stopper carrying a glass tube which ends in the pan _f_ as shown at _e_. The eudiometer is filled to the stop-cock with a solution of potassium ferrocyanid of about fourteen per cent strength. The dish _f_ is also filled up to the height indicated in the figure with the same solution. The solution of nitrite is used in such quantities that the nitric oxid evolved will occupy a space of about twenty cubic centimeters. The whole eudiometer should contain about fifty-seven cubic centimeters. The nitrite solution is added to the eudiometer by means of a funnel, _a_. The vessel containing it is washed out with a little water and then with acetic acid and finally with a few cubic centimeters of strong potassium ferrocyanid solution. The last fluid flows through the solution of nitrite and acetic acid and thus mixes it with the solution already in the eudiometer. The liquids reacting on each other float together on the strong ferrocyanid solution and each one of them is at once pressed downward by the gases which are evolved. When the evolution of gas becomes slower the apparatus should be shaken for about twenty minutes, moving it back and forth without taking the bottom of it out of the dish. When there is no longer any evolution of gas, water is added through a slowly, until the heavy potassium ferrocyanid solution is almost completely driven out of the eudiometer. The opening of the tube at _e_ is then closed with the thumb, the apparatus is taken out of the dish, shaken for some time in a vertical direction and again placed in the dish. Water of any required temperature is now allowed to flow through the jacket, _g_, _h_, until the temperature is constant, when the volume of nitric oxid is read. The whole experiment can be performed in less than an hour. Operating in this way, at the end there is in the eudiometer a liquid which is not very different from water and one whose coefficient of solubility for nitric oxid is practically the same as that of water. The gas volume read is to be corrected for temperature, pressure, tension of the aqueous vapor, height of the water column in the eudiometer, and, after the end of the calculation, five per cent of the volume of water remaining in the eudiometer is to be added to the volume of gas obtained. This is to compensate for the volume of the gas absorbed by the water. The method gives good quantitive results. =510. Method of Collecting Samples of Rain Water for Analysis.=—Warington collects rain water in a large leaden gauge having an area of 0.001 of an acre.[341] Of the daily collection of rain, dew, and snow water, an aliquot part amounting to a gallon for each inch of precipitation is placed in a carboy; at the end of each month the contents of the carboy are mixed, and a sample taken for analysis. In the carboy receiving the rain for nitric acid estimation a little mercuric chlorid is placed each month with the view of preventing any change of ammonia into nitric acid. It may be doubted, however, if this precaution is necessary, as the rain water thus collected always contains a very appreciable amount of lead; and experiments have shown that on the whole, rain water more frequently gains than loses ammonia by keeping. _Preparation of the Sample._—The method first employed by Warington was to concentrate ten pounds of the rain water in a retort, a little magnesia being used to decompose any ammonium nitrite or nitrate present. Concentration by evaporation in the open air, and especially over gas, results in a distinct addition to nitrites present. When concentrated to a small bulk, the water is filtered and evaporated to dryness in a very small beaker. The nitrogen as nitrates and nitrites is then determined by means of the methods already described. DETERMINATION OF FREE AND ALBUMINOID AMMONIA IN RAIN AND DRAINAGE WATERS AND SOIL EXTRACTS. =511. Nessler Process.=—The quantities of free ammonia in rain and most drainage waters are minute, but may reach considerable magnitude in some sewages. By reason of these minute proportions, gravi- and volumetric methods are not suitable for its quantitive determination. Recourse is therefore had to the delicate colorimetric reaction first proposed by Nessler. This reaction is based on the yellowish-brown coloration produced by ammonia in a solution of mercuric iodid in potassium iodid. The coloration is due to the formation of oxydimercuric ammonium iodid, NH₂Hg₂OI, and takes place between the molecule of free ammonia and the mercuric iodid dissolved in the alkaline potassium iodid as represented by the following equation: Hg—O—Hg—I Hg / / \ O + 2H₂N = 2O NH₂I + H₂O \ \ / Hg—O—Hg—I HG _Nessler Reagent._—Dissolve thirty-five grams of potassium iodid in 100 cubic centimeters of water. Add to this solution gradually a solution of seventeen grams of mercuric chlorid in 300 cubic centimeters of water until a permanent precipitate of mercuric iodid is formed. Add now enough of a twenty per cent solution of sodium hydroxid to make 1000 cubic centimeters. The mixed solutions, at room temperature, are treated with additional mercuric chlorid until the precipitate formed, after thorough stirring, remains undissolved. This precipitate is then allowed to subside, and when the supernatant liquid is perfectly clear, it is decanted or filtered through asbestos and kept in a well-stoppered bottle in a dark place. The part in use should be transferred to a smaller bottle as required. The solution should be made for a few days before using, since its delicacy is increased by keeping. The nessler reagent should show a faint yellow tint. If colorless it is not delicate, and shows the addition of an insufficient quantity of mercuric chlorid. When properly prepared, two cubic centimeters of the reagent poured into fifty cubic centimeters of water containing 0.05 milligram of ammonia will at once develop a yellowish-brown tint. _Preparation of Ammonia-Free Water._—To pure distilled water add pure, recently-ignited sodium carbonate, from one to two grams per one liter, and distill. When one-fourth of the whole has passed over, the distillate may be regarded as free from ammonia; fifty cubic centimeters of the following distillate should give no reaction with the nessler reagent. The distillation should be continued until the residual volume in the retort is about one-fourth of the original, and the distillate free of ammonia is carefully preserved in close glass-stoppered bottles previously washed with ammonia-free water. Pure water, free of ammonia may also be obtained by distilling with sulfuric acid. _Comparative Solution of Ammonium Chlorid containing 0.00001 gram Ammonia in one cubic centimeter._—Dissolve 3.15 grams H₄NCl in ammonia-free water and make the volume up to one liter. Take ten cubic centimeters of the above solution and dilute to 1000 with water, free from ammonia. _Solution containing 0.00001 gram Nitrogen in one cubic centimeter._—Dissolve 3.82 grams H₄NCl in water, free from ammonia and dilute with same to 1000 cubic centimeters. Dilute ten cubic centimeters of the above solution to 1000. _The Distillation._—Any kind of suitable retort or flask connected with a good condenser may be used. The capacity of the retort should be from 700 to 1,000 cubic centimeters. The retort and condenser preferred by Leffmann and Beam are shown in Fig. 91. Any good lamp may be used in which the flame is under complete control. The gauze burner shown in the figure is easily controlled and distributes the heat evenly over the surface of the retort thus diminishing the danger of fracture. The apparatus having been previously rinsed with distilled water receives 500 cubic centimeters of the liquid to be tested for ammonia, together with a few pieces of recently ignited pumice stone to prevent bumping and five cubic centimeters of the twenty percent sodium carbonate solution to render its contents alkaline. The water is raised to the boiling-point and with gentle ebullition fifty cubic centimeters of distillate collected. The distillate is conveniently collected in a color-comparison cylinder of thin white glass and flat bottom, about two and a half centimeters in diameter, and marked at fifty and one hundred cubic centimeters. Two cubic centimeters of the nessler reagent are added and if ammonia be present a yellowish-brown color will be developed, the intensity of which is matched by taking portions of the ammonium chlorid solution, diluting to fifty cubic centimeters with pure water and treating with the same quantity of the nessler reagent. The process is repeated until a distillate is obtained which gives no reaction for ammonia. The sum of the quantities obtained in the several distillates gives the total amount of ammonia in the 500 cubic centimeters of the water taken. In most cases practically all the ammonia is obtained in three or four portions of the distillate. FIGURE 91. RETORT FOR DISTILLING AMMONIA. ] _Albuminoid Ammonia._—The residue from the process just described is employed for the purpose of determining the albuminoid ammonia. Two hundred grams of potassium hydroxid and eight grams of potassium permanganate are dissolved in 1,000 parts of distilled water. Fifty cubic centimeters of the solution are placed in a porcelain dish with 100 cubic centimeters of distilled water and evaporated to fifty cubic centimeters. This liquid is placed in the retort and the distillation resumed and continued until an ammonia-free distillate is obtained. The total albuminoid ammonia is determined by taking the sum of the quantities in the several distillates. =512. Nessler Reagent of Ilosvay.=—To secure greater delicacy in nesslerizing, Ilosvay uses a reagent prepared as follows:[342] Dissolve two grams of potassium iodid in five cubic centimeters of water, heat the solution gently, and add three grams of mercuric iodid. After the solution is cooled, add an additional portion of three grams of the mercury salt, and then twenty cubic centimeters of water, and wait until the precipitation is complete. After filtering, there are added to the filtrate from twenty to thirty cubic centimeters of a twenty per cent solution of potassium hydroxid. Only the limpid supernatant liquid is used in the analytical work. With this reagent, Ilosvay has been able to detect 0.02 milligram of ammonia in 110 cubic centimeters of water. AUTHORITIES CITED IN PART SEVENTH. Footnote 274: Comptes rendus, Tome 84, pp. 301, et seq. Journal of the Chemical Society, (Transactions), 1878, p. 44; 1879, p. 429; 1884, p. 637. American Chemical Journal, Vol. 4, p. 452. Proceedings of the American Association for the Advancement of Science, Vol. 41, p. 105. Annales de l’Institut Pasteur, Tome 4, pp. 218, 257, 760; Tome 5, p. 92. Footnote 275: Comptes rendus, Tome 118, p. 604. Footnote 276: Bulletin de la Academie royale de Belgique, [3], Tome 25, p. 727. Journal of the Chemical Society, (Abstracts), June, 1894, p. 248. Footnote 277: Chemical News, Oct. 13, 1893, p. 176. Footnote 278: Comptes rendus, Tome 109, p. 883. Footnote 279: Op. cit. supra, Tome 89, pp. 891, et seq. Footnote 280: Journal of the Chemical Society, (Transactions), Vol. 45, pp. 645, et seq. Footnote 281: Jahresbericht der Agricultur Chemie, 1881, S. 43. Footnote 282: Annual Report of the British Board of Health, 1883. Footnote 283: Annales de l’Institut Pasteur, 1891, S. 93. Footnote 284: Philosophical Transactions of the Royal Society of London, Vol. 181, (1890). Footnote 285: Zeitschrift für Biologie, Band 9, S. 172. Footnote 286: Archives de Science Biologique à St. Petersbourgh, Tome 1, p. 1331. Footnote 287: Annales de l’Institut Pasteur, 1891, pp. 581, et seq. Footnote 288: Op. cit. supra, 1891, Plate 18, Fig. 2. Footnote 289: Op. cit. supra, 1891, pp. 595, et seq. Footnote 290: Op. cit. supra, 1891, Plate 18, Fig. 1. Footnote 291: Journal of the Chemical Society, (Transactions), 1891, pp. 498, et seq. Footnote 292: Annales de l’Institut Pasteur, 1891, pp. 605, et seq. Footnote 293: Journal of the Chemical Society, (Transactions), 1882, p. 357. Footnote 294: Annales de Chimie et de Physique, 1854, Tome 40, p. 479. Zeitschrift für analytische Chemie, 1870, S. 24; 1877, S. 291. Die Landwirtschaftlichen Versuchs-Stationen, Band 12, S. 164. Journal of the Chemical Society, (Transactions), 1880, p. 468; 1882, p. 345; 1889, p. 537. Footnote 295: Encyclopedie Chimique, Tome 4, p. 151. Footnote 296: Annales de la Science Agronomique, 1891, pp. 263, et seq. Footnote 297: Berichte der deutschen chemischen Gesellschaft, Band 23, S. 1361. Footnote 298: Zeitschrift für analytische Chemie, Band 9, S. 24, 401. Die Landwirtschaftlichen Versuchs-Stationen, Band 9, S. 9. Berichte der deutschen chemischen Gesellschaft, Band 6, S. 1038. Footnote 299: Zeitschrift für analytische Chemie, Band 33, S. 200. Footnote 300: Apotheker Zeitung, 1891, Band 5, S. 287. Footnote 301: Sutton’s Volumetric Analysis, 3d edition, p. 316. Warington, Journal of the Chemical Society, (Transactions), 1879, p. 376. Footnote 302: Report of the National Board of Health, 1882, p. 281. Footnote 303: Berichte der deutschen chemischen Gesellschaft, Band 11, S. 432. Footnote 304: Bulletin de la Société Chimique, [3], Tomes 11–12, p. 625. Footnote 305: Encyclopedie Chimique, Tome 4, p. 154. Footnote 306: Zeitschrift für analytische Chemie, Band 7, S. 412. Fresenius, Quantitative Analysis, Grove’s translation, special part, p. 118. Footnote 307: Journal of the Chemical Society, (Transactions), 1879, pp. 578, et seq. Footnote 308: Bulletin 38, Department of Agriculture, Division of Chemistry, p. 204. Footnote 309: Die Landwirtschaftlichen Versuchs-Stationen, Band 41, S. 165. Footnote 310: Chemiker Zeitung, 1892, Band 16, S. 1952. Footnote 311: Zeitschrift für angewandte Chemie, 1893, S. 161. Footnote 312: Chemiker Zeitung, 1889, No. 15. Footnote 313: Vid. op. cit. 38, 1890, S. 695. Footnote 314: Archives de la Société Physique de Genève, Tome 31, p. 352. Footnote 315: Chemiker Zeitung, 1890, S. 1410. Footnote 316: Chemisches Centralblatt, 1890, Band 2, S. 926. Footnote 317: Vid. op. cit. 38, 1891, S. 241. Footnote 318: Vid. op. cit. 34, 1889, p. 538. Footnote 319: Op. cit. supra, 1881, p. 100. Footnote 320: Op. cit. supra, Vol. 57, p. 811. Footnote 321: Op. cit. supra, 1891, pp. 530, et seq. Footnote 322: Op. cit. supra, 1874, p. 630, and 1885, p. 86. Footnote 323: Sutton’s Volumetric Analysis, 4th edition, p. 103. Footnote 324: American Journal of Science, Vol. 44, p. 117. Footnote 325: American Chemical Journal, Vol. 11, p. 249. Footnote 326: Journal of the Franklin Institute, Vol. 127, p. 61. Footnote 327: Zeitschrift für Hygiene, Band 2, S. 163. Footnote 328: Chemical News, 1889, Nov. 29, 261. Footnote 329: Vid. op. cit. supra, p. 51. Footnote 330: Examination of Water for Sanitary and Technical Purposes, p. 28. Footnote 331: Chemical News, 1890, Jan. 10, p. 15. Footnote 332: Zeitschrift für angewandte Chemie, 1894, Heft 12, S. 347. Footnote 333: Journal of the Chemical Society, (Abstracts), 1891, p. 489. Footnote 334: Zeitschrift für analytische Chemie, Band 18, S. 597. Zeitschrift für angewandte Chemie, 1889, S. 666. Bulletin de la Société Chimique, [3], Tome 2, p. 347. Footnote 335: Op. cit. 57, p. 30. Footnote 336: Zeitschrift für angewandte Chemie, 1894, S. 349. Footnote 337: Bulletin de la Société Chimique, [3], Tomes 11–12, p. 218. Footnote 338: Encyclopedie Chimique, Tome 4, p. 262. Footnote 339: Peligot, Traité de Chimie Analytique appliqueè à Agriculture, p. 261. Footnote 340: Berichte der deutschen chemischen Gesellschaft, 1893, S. 589. Footnote 341: Journal of the Chemical Society, 1889, p. 537. Footnote 342: Op. cit. 64, p. 216. NOTE.—On page 158, paragraph 172, third line, insert, “and determining matters dissolved therein,” after “flow.” PART EIGHTH. SPECIAL EXAMINATION OF WATERS, VEGETABLE SOILS, AND UNUSUAL SOIL CONSTITUENTS. =513. Further Examination of Waters.=—Having described in the preceding part the approved methods of determining the oxidized nitrogen in waters and soil extracts there remains to be considered the examination of waters for other substances of importance to agriculture. Rain waters add practically nothing to the soil but nitric acid and ammonia, and, therefore, demand no further discussion here. In drainage and sewage waters, in addition to the oxidized nitrogen, there may be sufficient quantities of phosphoric acid and potash to make their further analysis of interest. But by far the most practical point to be considered is in the case of waters used for irrigation purposes where the continued addition to the soil of mineral matters may eventually convert fertile fields into barren wastes. In irrigated lands there is practically no drainage and the whole of the water is removed by superficial evaporation. It is easily seen how these mineral matters tend to accumulate in that part of the soil in which the rootlets of plants seek their nourishment. =514. Estimation of Total Solid Matter.=—The total solid contents of a sample of water are determined by evaporating a known volume or weight to dryness and weighing the residue. For comparative purposes a given volume of water may be taken if the solid contents do not exceed four grams in a United States gallon. The water should be measured at a temperature of about 15°.5. Where the content of mineral matter is greater it is best to weigh the water and calculate the solid contents to parts per one hundred thousand. For practical purposes in the United States it is customary to state the content of solid matter in grains per gallon. Since, however, the gallon has so many different values it is always necessary to indicate what particular measure is meant. In ordinary spring and well waters the volume to be used is conveniently taken at 100 cubic centimeters. To avoid calculation a volume in cubic centimeters corresponding to some decimal part of a gallon in grains may be taken and the weight in milligrams will then be equivalent to the grains per gallon. Thus in the imperial gallon which contains 70,000 grains of distilled water at 15°.5, seventy cubic centimeters may be taken. If the residue weigh twenty-five milligrams the water contains twenty-five grains of solid matter per gallon. The United States gallon at 15°.5 contains 58,304 grains of distilled water. In this case 58.3 cubic centimeters should be used, or double this amount and the weight in milligrams be divided by two. The evaporation may be made in a platinum, porcelain, or aluminum dish, preferably with a flat bottom; The dish does not need to hold the whole volume at once, but the water may be added from time to time as the evaporation continues. The dish, however, should, as a rule, hold not less than 100 cubic centimeters. The evaporation is best conducted over a steam-bath, and after the complete disappearance of the liquid the heating should be continued until the residue is perfectly dry. In the case of mineral waters highly impregnated with inorganic salts, a smaller volume or weight may be taken, and greater care must be exercised in drying the residue. For the purpose of qualitively determining the percentage of special ingredients, quantities of the water should be taken inversely corresponding to the content of the ingredient desired. In general, it will not be necessary to evaporate the sample to complete dryness, but only to concentrate it to a volume convenient for the application of the analytical process. Where a complete quantitive analysis of the solid residue is desired, a sufficient quantity of the water is evaporated to give a weighable amount of the least abundant ingredient. The total solid content of the water having been previously determined, the actual weight or volume of the water taken to obtain the above residue is of no importance. =515. Estimation of the Chlorin.=—The chlorin in the solid residue from a sample of water may be determined directly by dissolving the soluble salts in distilled water, to which enough nitric acid is added to preserve the solution slightly acid. After filtering and washing, silver chlorid is added, little by little, with constant shaking until a further addition of the reagent produces no further precipitate. The beaker or flask should be placed in a dark place, on a shaking apparatus which is kept in motion until the precipitate has entirely settled in a granular state. The silver chlorid is then collected on a gooch, washed free of all soluble matter, dried at 150° and weighed. If the precipitate be ignited to incipient fusion, a porcelain gooch should be used. A more convenient method is to determine the chlorin directly in the water, or, where the quantity is too minute, after proper concentration, volumetrically by means of a titrated solution of silver nitrate, using potassium chromate as indicator. As soon as the chlorin has all united with the silver, any additional quantity of the silver nitrate will form red silver chromate, the permanent appearance of which indicates the end of the reaction. This process is especially applicable to water, which in a neutral state contains no other acids capable of precipitating silver. The chromate indicator does not work well in an acid solution. =516. Solutions Employed.=—A quantity of pure silver nitrate, about five grams, is dissolved in pure water and made up to a volume of one liter. For determining the actual strength of the solution, 0.824 gram of pure sodium chlorid is dissolved in water and the volume made up to half a liter. Twenty-five cubic centimeters of this solution are placed in a porcelain dish, and a few drops of the solution of potassium chromate added. The silver nitrate solution is allowed to flow into the porcelain dish from a burette graduated to tenths of a cubic centimeter. The red color produced as each drop falls, disappears on stirring as long as there is any undecomposed chlorid. Finally a point is reached when the red color becomes permanent, a single drop in excess of the silver nitrate being sufficient to impart a faint red tint to the contents of the dish. The solution of potassium chromate is prepared by dissolving five grams of the salt in 100 cubic centimeters of water. Silver nitrate solution is added until a permanent red precipitate is produced, which is removed by filtration, and the filtrate is employed as the indicator as above described. Water with any considerable quantity of chlorin can be treated directly with the reagents; when the percentage of chlorin is low, previous concentration to a convenient volume is advisable. In waters containing bromids and iodids these halogens would be included with the chlorin estimated as above. For agricultural purposes such waters have little importance. In the case of soluble carbonates capable of precipitating silver this action can be prevented by acidifying the water with nitric acid and afterwards removing the excess of acid with precipitated calcium carbonate. In this reaction McElroy recommends the use of Congo paper, which is not affected by the carbon dioxid but is turned blue as soon as an excess of nitric acid is added. After the addition of the calcium carbonate the mixture should be boiled to expel carbon dioxid.[343] Irrigation waters from natural sources or derived from sewage rarely contain enough chlorin to make their use objectionable. On the other hand, when water is obtained for this purpose from artesian wells it may often contain a quantity of chlorin which will eventually do more harm to the arable soil than the water will do good. =517. Carbon Dioxid.=—Free carbon dioxid in water has no significance in respect of its use for irrigation purposes. Such waters, however, are usually of a highly mineral nature and thus are justly open to suspicion when used for farm animals and on the field. The presence of free carbon dioxid as has already been pointed out in paragraph =42=, gives to water, one of its chief sources of power as an agent for dissolving rocks and ultimately forming soil. The estimation of the total free carbon dioxid in a sample of water issuing from a spring or well is a matter of some delicacy by reason of the tendency of this gas to escape as soon as the water reaches the open air and is relieved from the natural pressure to which it has been subjected. The actual quantity of the gas remaining in solution at any given time is determined as follows: 100 cubic centimeters of the water are placed in a flask with three cubic centimeters of a saturated solution of calcium and two of ammonium chlorid. To this mixture is added forty-five cubic centimeters of a titrated solution of calcium hydroxid. The flask is stoppered, well shaken, and set aside for twelve hours to allow the complete separation of the calcium carbonate formed. When the supernatant liquid is perfectly clear an aliquot part thereof, from fifty to one hundred cubic centimeters, is removed and titrated with decinormal acid with phenacetolin or lacmoid as an indicator. From the quantity of calcium hydroxid remaining unprecipitated the amount which has been converted into carbonate can be determined by difference. The difference between the quantity of calcium hydroxid originally present in the solution and that remaining after the above treatment multiplied by the factor 0.0022 will give the weight of carbon dioxid present in the water in a free state or in excess of that present as normal carbonates. UNUSUAL CONSTITUENTS OF SOIL. =518. Boric Acid.=—Boron, while not regarded as an essential plant food, is yet found quite uniformly in the ashes of a large number of plants. It may, therefore, be of some interest to the agricultural analyst to determine the amount of it which may be present in a soil extract or mineral water. For this purpose the following method due to Gooch may be employed.[344] To one liter of the water supposed to contain boric acid add enough sodium carbonate to produce distinct alkalinity. After evaporation to dryness acidify the residue with hydrochloric acid, apply a piece of turmeric paper and dry at a moderate heat. The usual brown-red tint will reveal the presence of boric acid. The quantitive estimation of the acid is accomplished as follows: One or more liters of the water rendered alkaline as above are evaporated to dryness. With the aid of as small a quantity as possible of acetic acid the dry residue is transferred to a distillation flask and condenser arranged as shown in Fig. 92. About one gram of recently ignited pure lime, cooled in a desiccator and weighed accurately, is introduced into the flask at the bottom of the condenser and slaked by a few cubic centimeters of water. When the flask is attached, the terminal tube of the condensing apparatus should dip into the lime-water in the flask. The heating-bath is partly filled with paraffin at a temperature of about 120°. The paraffin-bath is raised so that the entire bulb of the flask is immersed therein and the distillation continued until all the liquid has been distilled. The bath is removed and after cooling somewhat, ten cubic centimeters of methyl alcohol are introduced by means of the stoppered funnel-tube and the process of distillation repeated. This operation with methyl alcohol is repeated five times. The boric acid passes off with the distillate and is found in the flask below the condenser as calcium borate. The contents of the distillation flask are evaporated to dryness and ignited conveniently in the same crucible in which the lime was burned. The increase in weight represents the quantity of boric anhydrid, B₂O₂ obtained. FIGURE 92. GOOCH’S APPARATUS FOR BORIC ACID. ] =519. Method Of Moissan.=—The principle of the method of Gooch, which has just been described, is applied by Moissan in a slightly modified manner.[345] In this method the generating flask is made smaller than in the Gooch apparatus, and the funnel at the top is oval and provided with a ground-glass stopper. It is closed at the bottom with a glass stop-cock, and the slender funnel-tube enters through a rubber stopper and ends about the middle of the bulb of the flask. The delivery-tube is longer than in Fig. 91, and is bent upward at its middle part in the form of an obtuse angle. The receiving flask is connected with the condenser by means of a tube-shaped funnel, which prevents any regurgitation into the generating flask. The receiving flask also has attached to it a three-bulb potash absorption tube, through which all vapors escaping from the receiving flask must pass. The bulbs contain a five per cent solution of ammonia. The receiving flask should be placed in a crystallizing dish and kept surrounded with ice-water. The boron which is to be estimated should be in the form of boric acid. This can readily be accomplished by treating the residue to be analyzed with nitric acid in a sealed tube. The mixture is introduced into the generating flask, washing with a little nitric acid, and evaporated to dryness. The heat is removed, and, by means of the funnel, ten cubic centimeters of methyl alcohol added, and distillation is renewed. This operation with methyl alcohol is repeated four times, taking care to distill to dryness in each case before the addition of a fresh quantity of alcohol. Afterwards, there is introduced into the apparatus one cubic centimeter each of distilled water and nitric acid and the distillation again carried to dryness. The treatment with methyl alcohol, as described above, is then repeated three times. To determine whether all the boric acid have passed over, the receiving flask at the bottom of the condenser is disconnected and a drop of the alcohol taken from the end of the condensing tube by means of a filament of filter paper. On burning, the flame should not show any trace of green. In case a green color is observed, the distillation with nitric acid and methyl alcohol must be repeated. The ammonia in the potash bulbs serves to arrest any of the vapors carrying boric acid which might escape from the receiving flask. The contents of the bulbs are to be mixed with the liquid in the receiving dish, and the whole poured onto a known weight of recently ignited calcium oxid contained in a platinum dish, and the mixture briskly stirred. If the liquid be very acid the platinum dish should be kept in ice-water to prevent heating. After fifteen minutes the liquid usually becomes alkaline, and it is then evaporated at a temperature below the boiling-point of methyl alcohol (66°). The mass, after the methyl alcohol has disappeared, is dried at a gradually increasing temperature, and finally, the dish is ignited over a blast, at first covered and afterwards open. The dish is covered and weighed and again ignited until constant weight is obtained. The lime used should be specially prepared by igniting calcium nitrate incompletely, and reigniting a portion of this to constant weight just before beginning each analysis. The calcium oxid is then obtained in a perfectly fresh state. It should be employed in considerable excess, for each half gram of boric acid at least eight grams of the lime. The operation is tedious but the results are quite accurate. SPECIAL TREATMENT OF MUCK SOILS. =520. General Considerations.=—Deposits of muck which are to be used as soil for cultural purposes, or marsh lands, containing large quantities of organic matter, require a special treatment in addition to the general principles of examination illustrated in the previous pages. These soils, essentially of an organic origin, do not permit of the same treatment either chemical or physical as is practiced with soils of a mineral nature. For instance, it would be useless to attempt a silt analysis with organic soils, and the extraction of them with hydrochloric acid for the purpose of determining the materials passing into solution would prove of little utility. The object of the examination is not only to obtain knowledge of the ultimate constitution of the sample, but also, and this is the practical point, to gain some idea of its stores of plant food and of the proper steps necessary to secure a supply of the deficient nutrients. The final analytical processes for the estimation of the constituents of a muck or vegetable soil are the same as those already given, but the preliminary treatment is radically different. =521. Sampling.=—First of all the geologic and meterologic conditions of the muck formations must be determined as nearly as possible. It is fair to presume that these formations are of comparatively recent origin, in fact that they are still in progress. The geologic formation in the vicinity of the deposit should be noted. Information should be given in respect of the character of the water, whether running or stagnant, fresh, salt, or brackish, and changes of level to which it is subject, should be noted. It should be particularly stated whether the vegetable growth contributing to the formation be subject to frost or freezing. The character of the growth is to be carefully noted, and observation made of any changes in vegetation due to drainage preparatory to cultivation. It is to the original vegetation that the chief vegetable accretions in the muck must be accredited. In all cases, for purposes of comparison, some samples must be taken from parts of the field which have not been under cultivation or fertilization. The original properties of the muck can thus be determined and compared with the portions which have been changed under cultivation. If the vegetation in different parts of the field vary it is an indication that the muck is not homogeneous, and in such cases all the different kinds must be separately sampled. Any alluvial deposit should be carefully separated from the muck found _in situ_, for the two layers are radically different in nature. The sampling should be made by digging a pit, if possible to the bottom of the muck formation, and taking the samples at depths of one foot from one or all of the sides. The samples from sections of even depth are to be mixed and about five kilograms of the well-mixed sample preserved. Blocks of the unbroken and unshattered material should also be taken from each section for the purpose of determining permeability to water and air. All living vegetable matter should be as fully as possible removed before the sampling begins. The nature of the subsoil must be observed, and it should be stated whether it be sand, clay, limestone, etc. Fresh samples should be taken at various depths for the purpose of determining the content of moisture in the manner described in paragraph =65=. The tubes used are made sharp at the end to be inserted in the soil, and so arranged as to cut cylinders of soil a trifle smaller than their interior diameter. By this means the sample slips easily into its place. The same care and judgment must be used in taking these samples as are required in the case of common soils. _Illustration._—Samples of muck soil taken at Runnymede, Florida. (_a_) Formation. Littoral fresh-water lacustrine deposits, varying from a few inches to four feet in depth, and from a few feet to half a mile in width. (_b_) Vegetation before drainage. Saw grass (_Cladium Mariscus_ or effusum). (_c_) Principal present vegetation (see pages 59–60). (_d_) _Kinds of Soil._—The muck shows two distinct colors, black and brown. The vegetation, however, seems to be the same in both cases. The black muck has the appearance of being more thoroughly decomposed. (_e_) _Geologic Formation._—This portion of the Florida peninsula is covered generally with sand due to marine submergence during recent geologic periods. The forest growth is pine. The drainage from the pine land is towards the muck deposits. The pine land lies from four to ten feet higher than the surface of the muck and is much less subject to frost. =522. Water Content.=—The capacity of a muck soil for retaining water is very great. In a moist state these soils are heavy and apparently quite firm. When dry they are light and fluffy and unsuited to hold the rootlets of plants. Saturated to their greatest capacity they hold considerably more than their own weight of water. Attention has already been called to the danger of drying such samples at a high temperature. As in most cases of drying exposure at the temperature of boiling water until a constant weight is obtained is a perfectly safe way. It is hard to say what comes off in addition to water at a higher temperature. All that comes off even at the temperature of boiling water is not water. The method of determination usually employed in this laboratory is the following: From four to five grams of the material are spread as evenly as possible over the flat bottom of a circular aluminum dish, about seven centimeters in diameter. The dish is exposed for three hours at the temperature of boiling water and then kept for two hours in an air-bath at 110°. At the end of this time constant weight is obtained. Additional drying at 110° for five hours, usually gives no further loss of volatile matter. The dish should be covered during weighing on account of the hygroscopicity of the residue. When well sampled the dry matter thus obtained serves as the basis of calculation for the general analytical data. _Results._—Samples of muck soil taken in brass tubes in March during the dry season had the following contents of moisture: Matter volatile at 110°, per cent. Taken near the surface 61.60 „ one foot below the surface 84.35 „ two feet „ „ „ 81.52 It is thus seen that the normal content of moisture in such a soil during the dry season, exclusive of the top layer, is about eighty per cent. =523. Organic Carbon and Hydrogen.=—The organic carbon and hydrogen in muck soils are determined on the carefully dried sample by combustion with copper oxid. This process gives not only the quantities of these bodies combined as humus, but also those in a less advanced state of decomposition and present as fatty bodies or resins. The method employed is given on pages 319–20. _Results._—The data obtained on a sample of muck soil from Florida are as follow: Per cent. carbon. Per cent. hydrogen. One foot from surface 57.67 4.48 Two feet „ „ 47.07 5.15 Three „ „ „ 8.52 0.53 The last sample was largely mixed with sand, the muck at the point when it was taken not being quite three feet deep. =524. Total Volatile and Organic Matter and Ash.=—The ignition of the sample should be very carefully conducted at the lowest possible temperature. About five grams of the air-dried sample or double that amount of the moist sample should be taken. In the latter case the calculations should be made on the basis of the dry material. The ignition should be continued with frequent stirring with a platinum wire until all organic matter is destroyed. At the same time in a large dish one or more kilograms of the sample should be ignited in order to secure an ash for analysis. The ash should be quickly weighed to avoid absorption of moisture. =525. Sulfur.=—The sulfur present in muck is combined either in an organic form or with iron. It may be estimated by the method of Fleischer.[346] From five to ten grams of the sample are ignited carefully in a hard glass tube in a stream of air or better of oxygen. The sulfur compounds escape as sulfuric or sulfurous acid. The combustion is carried on in the apparatus shown in Fig. 93. FIGURE 93. APPARATUS FOR DETERMINING SULFUR. ] The end of the tube A, next to B, is lightly stopped with a plug of glass wool, the substance introduced and held in place by a second plug of glass wool next to C. A is connected to the working flask C, containing water, as is shown in the illustration. The chief object of the flask is to control the rate of aspiration of the air or oxygen. A is also connected with the bulb-tube B, as shown in the figure. B contains potash-lye, free of sulfur. On the top of B is placed a drying tube filled with glass pearls, moistened with potash-lye. This is connected with the aspirator by a small bulb-tube bent at right angles, as indicated. The bulb of this tube contains a little neutral litmus solution, which must suffer no change of color during the progress of this analysis. The tube, thus arranged, is placed in a combustion furnace and gradually heated to redness, beginning with the part next to B. A moderate stream of air or oxygen is passed through the tube during the operation. Any product of the combustion collecting in the tube before reaching B, is driven into B by careful heating. At the end of the combustion the contents of B are acidified with hydrochloric acid, and treated with bromin to convert the sulfurous into sulfuric acid. The excess of bromin is afterwards removed by boiling, and the sulfuric acid precipitated by barium chlorid and estimated in the usual way. The total sulfuric acid having thus been determined, the sample is extracted with water and the sulfuric acid estimated in the residue. The sulfuric acid in a muck which is injurious to vegetation is classified by Fleischer, as follows: (1) Free sulfuric acid. (The residue which is obtained by calculation as sulfates of the bases in the water extract.) (2) The sulfuric acid contained as copperas (calculated from the iron oxid content of the aqueous extract). (3) Sulfuric acid arising from the oxidation of pyrites (calculated from the sulfuric acid obtained by treatment of the water-extracted sample). A better idea of the distribution of the sulfur in the sample can be obtained by estimating it according to the method given in paragraph =385=. =526. Phosphoric Acid.=—The method for determining the phosphorus in muck is given in paragraph =382=. The process given in =378= may also be used. The method of extraction with hydrochloric acid is wholly unreliable as a means of determining the available phosphoric acid in muck. There are some vegetable soils which contain so much iron and lime that the whole of the acid ordinarily used would be consumed thereby. This fact has been clearly pointed out by Wiklund in determining the phosphoric acid in a large number of peaty soils.[347] His experiments, were made with acid of only four per cent strength. In some cases, however, it may be found useful to determine the quantity of phosphoric acid which can be extracted with hydrochloric acid, and afterwards to separate the humus and determine the content of phosphoric acid therein. =527. Humus.=—In this laboratory the humus is estimated by the method of Huston and McBride, as given in paragraph =312=. In samples so rich in organic matter the method of Grandeau does not give as good results. Often more than half the weight of the dry substance is soluble in ammonia after treatment with acid. The nitrogen in the original sample and the separated humus should be estimated by moist combustion with sulfuric acid in the usual manner. =528. The Mineral Contents of Humus.=—The material obtained by precipitating the alkaline extract of a vegetable earth with an acid does not consist alone of oxygen, carbon, hydrogen, and nitrogen. The complex molecules which make up this mixture contain certain quantities of iron, sulfur, and phosphorus in an organic state. These bodies are left as inorganic compounds on ignition, provided there is enough of base present to combine with all the acid elements. Much of the sulfur and phosphorus, however, in these compounds might be lost by simple ignition. In such cases moist oxidation of these bodies must be practiced, or the gases of combustion passed over bodies capable of absorbing the oxidized materials in order to detect and determine them. The proper methods of accomplishing this have already been pointed out for vegetable soils, and the same processes are applicable in the case of extracted and precipitated humus. Another proof that both phosphorus and sulfur are present in humus in an organic state is found in the fact pointed out by Eggertz and Nilson, that the ash of muck soils is always richer in sulfuric and phosphoric acids than the solution obtained therefrom by hydrochloric acid.[348] In a sample of muck examined by them there was found in the ash 1.46 per cent SO₃, and in the acid extract only 0.05 per cent SO₃; and in the ash 0.3 per cent P₂O₅, while in the extract only 0.04 per cent P₂O₅. =529. Combustion of the Humus.=—The percentage composition of the extracted humus can be determined, after drying to constant weight, by combustion with copper oxid. There is little use in trying to assign definite chemical formulas to any of the components of the complex which we call humus. Some of the supposed formulas have been given on pages 61 and 62. =530. Ether Extract.=—Most peaty soils, when very dry, are not easily moistened with water. This is due to a superficial coating of fatty or resinous bodies which prevents the water from reaching the muck particles. In such cases water will pass between the particles and percolate to a considerable depth, but without wetting. This oily matter can be removed by treating the dry material with ether in any approved extraction apparatus. For the separation of the more purely fatty bodies, light petroleum may be used, while the total of such matters is extractable with sulfuric ether. The extracted bodies should be examined to determine their nature, whether fatty, resinous, or of other materials soluble in ether. The quantity of this material in some muck soils is remarkably high. In a Florida muck, examined in this laboratory, 18.95 per cent in the air-dried substance, which contained still 41.83 per cent of water, or about 32.5 per cent of the water-free material were found to be soluble in ether. The color of the ether extract may be almost black, showing the extraction of a part of the humus or coloring matter in the muck. This extractive coloring matter may also be a partial oxidation product of the original chlorophyl of the plant. =531. Further Examination of the Ether Extract.=—The ether extract should be first treated with petroleum ether, unless this substance be used first in extraction. Afterwards, it is to be exhausted with strong alcohol, and the quantities of material soluble in the three reagents separately determined. The nitrogen is further to be determined in the several extracts, and, for control, in the residue of the muck. The method of procedure practiced in this laboratory is to first extract the sample with petroleum ether, which will yield any free fat acids, fats, or oils, waxes, and possibly some resinous matter. A weighed portion of the sample, about two grams, is extracted quantitively by one of the methods which will be described in the second volume of this manual. From two to five kilograms of the sample are then extracted in bulk for the purpose of securing a sufficient quantity of the material to use for further analysis.[349] In each case the petroleum is followed by pure ether, and in this way the chlorophyl, resins, etc., are obtained. This extract is examined also for its several proximate constituents.[350] The treatment with ether is followed by extraction with absolute alcohol for the removal of tannins and other glucosides, resins insoluble in ether, etc., and the extract subjected to the usual examination.[351] Instead of absolute alcohol a spirit of ninety-five per cent strength, or even of eighty per cent, may be used. The final residue should be subjected to the usual determination for nitrogen, volatile matter, ash, etc., in the manner already described. The large amount of resinous and other matters soluble in petroleum and ether, which is found in the Florida muck soils, is probably due to the proximity of pine forests, the débris of which, sooner or later, find their way to these littoral deposits. Considerable portions of organic humic acids and even humus itself, may also be removed by ether and alcohol and in every case nitrogen should be determined in these extracts. RARE CONSTITUENTS OF SOILS. =532. Estimation of Copper.=—The natural occurrence of copper in many vegetables has acquired additional significance by reason of its relation to added copper in canned peas and other preserves. Formerly, copper was not regarded, in any sense, as a plant food. Even now it can scarcely be considered as more than an accidental and non-essential constituent of vegetable matter. It is by no means certain, however, that copper may not be, in some sense, in organic combination, as phosphorus and sulfur often are. It is said, also, to be found in certain animal organisms, notably in the oyster. In the estimation of copper in soils, there is first made a hydrochloric acid solution of the sample. The solution is treated with well-washed hydrogen sulfid until well saturated. The precipitate is collected at once on a gooch, and washed with water containing the precipitating reagent. The filtrate is dried, gently ignited or roasted, and dissolved in aqua regia. After evaporating to dryness on a steam-bath, water and hydrochloric acid are added, and the copper reprecipitated in the manner described above. If zinc be present in the sample the solution should be made very strongly acid with hydrochloric before the treatment with hydrogen sulfid, otherwise some zinc may be carried down with the copper.[352] If lead be present it is also precipitated with the copper and can be separated as described below. In the filtrate from the solution in nitric acid after the second precipitation the copper is precipitated as hydroxid by potash, collected in a porcelain gooch, dried, ignited, and weighed as CuO. Or the copper may be secured as sulfate and estimated electrolytically in the manner described in volume second for the gravimetric estimation of sugar. =533. Estimation of Lead.=—If the soil contain lead this metal will be thrown down with the copper as sulfid in the manner described above. In this case the mixed sulfids are dissolved in nitric acid, diluted with water, filtered, and washed. The filtrate is treated with sulfuric acid in considerable excess, and evaporated until all the nitric acid has passed off and the sulfuric acid begins to escape. After cooling, water is added and the lead sulfate collected on a porcelain gooch and washed with water containing sulfuric acid. Finally it is washed with alcohol, dried, ignited, and the lead weighed as PbSO₄. =534. Estimation of Zinc.=—If zinc be present in the hydrochloric acid extract of a soil it may be estimated as carbonate after freeing it carefully of iron. The principal part of the iron should first be separated in the usual way by sodium acetate. In the warm solution (acid with acetic) the zinc is precipitated by hydrogen sulfid in excess. The beaker in which the precipitation takes place should be left covered in a warm place at least twelve hours. After collecting the zinc sulfid on a filter it is washed with water saturated with hydrogen sulfid. In order to free the zinc from every trace of iron it is better to dissolve the precipitate in hot dilute hydrochloric acid and reprecipitate as above, and, after boiling with some potassium chlorate, saturate it with ammonia. Any remaining trace of iron is precipitated as ferric hydroxid while the zinc remains in solution. The ferric hydroxid is separated by filtration and the filtrate, after acidifying with acetic, is treated with hydrogen sulfid as above. The zinc sulfid is dissolved again in hot hydrochloric acid, oxidized with potassium chlorate, the acid almost neutralized with soda and the zinc precipitated as carbonate with the sodium salt. After precipitation, the contents of the beaker are boiled until all free carbon dioxid is expelled, the carbonate collected on a filter, washed with hot water, dried, ignited, and weighed as ZnO. =535. Estimation of Boron.=—Boron has been found in the ashes of many plants and agricultural products. Whether or not it be an essential or only accidental constituent of plants has not been determined. Its occurrence in the soil, nevertheless, is a matter which the agricultural chemist can not overlook. The boron should be dissolved from the soil by gently heating with dilute nitric acid followed by washing with hot water. Boiling should be avoided on account of the volatility of boric acid. In the solution thus obtained, concentrated on a bath at a moderate temperature to a convenient volume, the boron is to be estimated by the method given in paragraphs =518= and =519=. AUTHORITIES CITED IN PART EIGHTH. Footnote 343: Bulletin 13, Chemical Division, Department of Agriculture, p. 1021. Footnote 344: Sanitary and Technical Examination of Water, p. 60. Footnote 345: Bulletin de la Société Chimique, [3], Tomes 11–12, p. 955. Footnote 346: Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 126. Footnote 347: Mitteilungen über die Arbeiten der Moor Versuchs-Station in Bremen; dritter Bericht, S. 540. Footnote 348: Biedermann’s Centralblatt, 1889, S. 664. Footnote 349: Dragendorff’s Plant Analysis, translation by Greenish, pp. 8, et seq. Footnote 350: Vid. op. cit. supra, pp. 31, et seq. Footnote 351: Vid. op. cit. 7, pp. 38, et seq. Footnote 352: Journal für praktische Chemie, Band 73, S. 241. NOTE.—On page 557, paragraph =500=, ninth line, read “red-yellow” instead of “blue.” INDEX. A Absorption, cause in soils, 119 determination, 287 of heat, by soils, 115 water, by soils, determination, 136–143 Acetic acid, solvent for soils, 344 Acid phenyl sulfate, reagent for nitric acid, 554, 555 soluble materials, extraction, 455 Adobe, analyses, 58 soils, 57 Aeolian rocks, 38 Air, absorption, 286 action, 51 Albuminoid ammonia, estimation, 572 Alkali salts, composition, 56 Alkalies and alkaline earths, estimation, 384 Alkaline soils, 53–55 Alumina, estimation, 354, 357, 362 Aluminum, 17 -mercury couple for nitric acid, 542 microchemical examination, 266 Ammonia, determination of free and albuminoid, 570–573 estimation, 448–452 formation in soils, 429 magnesia distillation process, 450 nitrification, 466 production, by microbes, 464 Ammonium chlorid, solvent for soils, 343 Apocrenic acid, 62 Apparatus for soil sampling, 82–86 Aqueous rocks, 32–38 vapor absorption, 283, 284 Armsby, soil absorption, 121 Assimilable phosphoric acid, method of Dyer, 410 Atomic masses, table, 3 Atwater, fish nitrogen, 14 Authorities cited in Part Eighth, 593 Fifth, 300 First, 63, 64 Fourth, 279–281 Second, 93, 94 Seventh, 573–575 Sixth, 456–458 Third, 169, 170 B Bacteria, action, 50 Barium, 23 microchemical examination, 265 Barus, theory of flocculation, 177–180 Beaker elutriation, comparison with Hilgard’s method, 239 method, comparison with Schloesing’s, 241 Belgian methods for soil extracts, 361–363 Bennigsen, method of silt analysis, 194 Berlin-Schöne method, 194 Bernard, calcimeter, 339 Berthelot and André, determination of residual water, 308 method of water determination, 305 nature of nitrogen in soils, 430–434 odoriferous matters in soils, 97 phosphoric acid in soils, 411 Bigelow, solubility of digestion vessels, 348 Boric acid, 580, 581 Boron, 17 estimation, 593 Boussingault and Lewey, method of determining absorption, 290 method for nitric acid, 524–526 Braun’s separating liquid, 271 Bréon’s method, 272 Brewer, chemical action, 177 Brögger’s apparatus, 276 Brucin, reagent for nitric acid, 557 Bulk analysis, 365–367 C Calcium, 18 microchemical examination, 264 Caldwell, preliminary treatment of soil samples, 88 Capillary attraction, determination, 145 movement of water, 153 Carbazol, reagent for nitric acid, 548 Carbon, 5 comparison of methods for estimating, 321 dioxid, diffusion in soils, 297 estimation in water, 579 in soils, apparatus for estimating, 293 occurrence in soils, 289 solvent for soils, 343 estimation of organic, 315 oxidation with chromic acid, 316 permanganate, 318 Carbonates, Belgian method, 342 deficiency in soils, 340 estimation, 337 Carnot, method for manganese, 397 phosphoric acid, 403 Chabrier, method for nitrous acid, 565 Chemical analysis of soils, 301–575 order of examination, 302 preliminary considerations, 301 elements in soils, 2 Chevreul, ammonium phosphate in guanos, 7 Chile, nitrate deposits, 15, 16 Chlorin, 6 estimation, 422 in water, 577 Mohr’s method, 424 Petermann’s method, 424 Wolff’s method, 423 Citric acid, solvent for soils, 344 Clarke, relative abundance of elements, 23 Classification of soils, 52 Clay, chemical nature, 232 colloidal, 231 mechanical determination, 242 properties, 223 separation, 230 suspension, 176 Clayey soils, effect of boiling on texture, 244–246 elutriation, 239 Cleavage of soil particles, 262 Coefficient of evaporation, determination, 144–146 Cohesion and adhesion of soils, 116, 117 Colloidal clay, estimation, 231 Color of rocks, 31 soil, determination, 97 Colorimetric comparison, delicacy, 548, 559 Compact soils, 90 Conductivity of soils, 115 Copper, estimation, 591 -zinc couple for nitric acid, 540, 542 Crenic acid, 61 Crum-Frankland process, 518 Crystal angles, measurement, 259 Culture media, composition, 468, 473, 474, 476, 479, 481, 483, 484, 486 solid, 479, 481 D Darton, Florida phosphates, 9 Davidson, origin of Florida phosphates, 7 Decay of rocks, 43–52 Deherain, measurement of percolation, 167–169 Desiccator, drying, 309 Devarda’s method for nitric acid, 534 variation of Stoklassa, 535 Diffusion of gases, general conclusions, 299 Dietrich’s elutriator, 209 Digestion of soil, 456 vessels, 347 Dilution method, experiments, 483, 485 Diphenylimid, reagent for nitric acid, 549 Diphenylamin, reagent for nitric acid, 553 Distillation, prevention of bumping, 441 Dobeneck, method of determining absorption, 287–290 Drainage, influence on porosity, 132 Durham, clay suspension, 176 Dyer, citric acid solution, 344 Dyer, method for assimilable phosphoric acid, 410 E Earth worms, action, 49 Eldridge, Florida phosphates, 10 Elements, different, simultaneous estimation, 425 relative abundance, 23 Elutriating tube, 236 Eruptive rocks, 41, 42 Estimation of gases in soils, 282–299 F Ferric oxid, estimation, 353, 356, 357, 362, 399, 401 Fine soil, capacity for holding water, 135 Fish as fertilizer, 14 Flocculation, 171 effect of chemical action, 177 theory, 177 Floccules, destruction, 175 Florida phosphates, origin, 7–12 Fluorin, 17–24 Forchhammer, agricultural value of fucoids, 13 Frear, method of determining soil temperatures, 111 Freezing and thawing, 44 Fuchs and De Launy, origin of potash deposits, 21 Fuelling, determination of water absorption, 139 G Gases, collection, 291 methods of study, 283 passage through the soil, 149, 150 determination, 150 relation to soil composition, 282 Gasparin, method of silt analysis, 195 Gautier, occurrence of oldest phosphates, 7 Gelatin, culture, 471–473 mineral, 473, 474 Gembloux station, method of soil solution, 350 German experiment stations, method of soil solution, 349 Glaciers, action, 45 Glucinic acid, 62 Goessmann, analysis of sea-weeds, 13 Gooch and Gruener, method for nitric acid, 546 estimation of boric acid, 580 Goss, method for phosphoric acid, 416–418 Grandeau, method of estimating humus, 324 H Hands, sterilization, 489 Hannén, diffusion of carbon dioxid in soils, 297 Harada’s apparatus, 275 Heinrich, determination of passage of gases through soils, 150 water absorption, 143 method of determining cohesion, 116, 117 Henrici, determination of water capacity of soils, 143 Hilgard, alkaline soils, 55 digestion vessels, 347 humus estimation, 324 hygroscopic coefficient, 284 influence of surface tension, 174 method for soil solution, 348 of silt analysis, 225 methods of analysis of soil extract, 356–361 preliminary examination of soils, 87 Hilgard’s elutriator, 226 method, comparison with Osborne’s, 239 Hooker’s method for nitric acid, 548 Humic acid, 61, 62 estimation, 331 Humus, 60 combustion, 589 estimation, 324 German method, 333 method of Pasturel, 336 Raulin, 334 Van Bemmelén, 332 summary of results, 330 mineral contents, 589 Huston and McBride, humus estimation, 326 method of determining soil absorption, 128 Hydrochloric acid, solvent for soils, 344 strength, 345 time of digestion, 345 treatment of soil with cold, 350 Hydrofluoric acid, solvent for soils, 352 Hydrogen, 5 estimation of organic, 323 Hygroscopic coefficient, determination, 284 Ignition, loss, 307 Ilosvay, nessler reagent, 573 Indiana, lysimeter of agricultural experiment station, 165 Indigo method for nitric acid, 524–531 Insoluble residue, analysis, 363 Belgian method, 364 Wolff’s method, 363 Interstitial space, determination, 134 Inverse capillarity, 146 Iron, 22 and alumina, separation from phosphoric acid, 414 French method, 399, 400 method of Sachsse and Becker, 401–403 microchemical examination, 266 J Jenkins, analysis of sea-weeds, 13 Johnson, method for nitric acid, 556 K Kaolin, estimation, 426–428 Kedzie, digestion vessels, 347 influence of drainage, 132 King, apparatus for soil sampling, 82 capillary movement of water, 153 methods of water movement, 151 Knop, method of determining soil absorption, 128 Knop’s silt cylinder, 189 Knorr, apparatus for carbon dioxid, 337 Kostytchoff, origin of humus, 60 Kühn’s silt cylinder, 189 L Lateral capillary flow, 153 Latitude, effect on decay of rocks, 46 Lead, estimation, 592 Lime, assimilable, 392 estimation, 354, 357, 362, 365, 384, 386, 388–394 of active, 389 available, 390 French method, 386, 388 method of Halle station, 393, 394 Russian method, 391 Lithium, microchemical examination, 264 Logarithmic constants, 254 Loges, humus estimation, 333 Loose soils, 89 Loughridge, time of digestion, 345, 346 Lunge and Lwoff, method for nitrous acid, 563 Lunge’s nitrometer, 519 improved, 520–524 Lysimetry, 158, 165 Mc McGowan’s method for nitric acid, 543 M Magnesia, estimation, 354, 360, 362, 365, 384, 394, 396 method of Halle station, 396 Magnesium, 18 microchemical examination, 264 Magnet, separation of silt particles, 278 Manganese, 23 estimation, 354, 360, 396, 397 French method, 397–399 Marx, method for nitric acid, 526–528 Masure’s silt apparatus, 210 Matiére noire, 324 Mayer, determination of water absorption, 138 Mayer’s modification of Schöne’s method, 220 Mechanical analysis of soils, 171–179 Mercury and sulfuric acid method, Noyes’ modification, 519 Warington’s modification, 518 Metamorphic rocks, 39 Metaphenylenediamin, reagent for nitrous acid, 557, 559 Microchemical examination of silt, 262, 266 Microscopic apparatus, 495 examination of silt separates, 256 Microscopical structure of rocks, 28, 29 Mineralogical examination of silt separates, 254–278 Minerals, classification, 26 in rocks, 24–26 machine for making sections, 267 Möckern, reduction method, for nitric acid, 533 Moissan, estimation of boric acid, 581 Moisture, effect on soil temperature, 102 estimation, 454 Moore, modification of silt analysis, 192 Muck soils, alcohol extract, 590 estimation of humus, 589 phosphoric acid, 588 sulfur, 587 ether extract, 590 organic carbon and hydrogen, 586 petroleum ether extract, 590 phosphoric acid, 415 sampling, 584 special treatment, 583 total volatile and organic matter, 586 water content, 585 Mulder, humic acid, 62 Müller, method of determining soil absorption, 126 Müntz and Marcano, origin of nitrate deposits, 14 N Naphthylamin, reagent for nitrous acid, 560 Nessler’s process, 570 reagent, 570 Nitrate deposits, 14–16 Nitrates, estimation, 435 Nitric acid, classification of reduction methods, 531, 532 development in soils, 461 estimation by colorimetric comparison, 548–559 oxidation of a colored solution, 524–531 reduction to ammonia, 531–543 classification of methods, 496–498 in presence of nitrous acid, 557 extraction from soil, 498–500 ferrous salt process, 500–518 iodometric estimation, 543–548 mercury and sulfuric acid method, 518 methods, relative merit, 498 nitric oxid process, 500–524 reduction by electric current, 540–543 solvent for soils, 351 ferment, isolation, 471, 477, 481 Nitrification, apparatus and manipulation, 468 effect of potassium salts, 463 general conclusions, 496 necessary conditions, 461–463 preparation of seed, 468 progress, 469 statement of results, 478 test of commencement, 469 Nitrifying organisms, classification, 487 distribution, 470, 471 microscopic examination, 480, 484 occurrence, 467 Nitrites, destruction, 478, 558 Nitrogen, 12 active soil, 434 Arnold and Wedemeyer’s method, 440 Dumas’ volumetric method, 446–448 economic value, 395 estimation in soils, 428–456 of amid, 451 volatile compounds, 452–454 Hilgard’s method, 436 Methods of Official Agricultural Chemists, 434 Müller’s method 438–440 soda-lime method, 445 nature in soils, 430–434 order of oxidation, 465 organic, in soils, 459–461 oxidized, estimation in soils, 459–570 soda-lime method, 441–444 in presence of nitrates, 444 Nitrous acid, development in soils, 461 estimation, by coloration of a ferrous salt, 567 colorimetric comparison, 559 potassium ferrocyanid, 567 classification of methods, 496–498 iodometric method, 564–567 ferment, isolation, 471, 477 Nöbel’s apparatus, 207 Nöllner, nitrate deposits, 16 Norwacki and Borchardt, auger for soil sampling, 83 O Odoriferous matters, determination, 98 in soils, 97 Official Agricultural Chemists, latest methods, 454–456 method for reduction of nitric acid, 532, 533 of analysis of soil extract, 353–356 soil solution, 349 Organic matter, estimation, 314 influence on absorption, 124 total, 315 Origin of soils, 43 Orth, classification, 185 Osborne, Berlin-Schöne method, 224 method, comparison with Schloesing’s, 241 of silt analysis, 196 -Schöne method, 219 comparisons, 223 Oxygen, 3 absorption, 286 estimation of organic, 324 P Packard, separation of silt particles, 273 Pasturel, estimation of humus, 336 Peligot, preliminary treatment of samples, 91 Percolation, measurement, 161 soils _in situ_, 164 Petermann, determination of water absorption, 138 method for phosphoric acid, 409 preliminary treatment of samples, 92 Petrographic examination of silt particles, 266 microscope, 256 Pfaundler, specific heat method, 104–110 Phenylsulfuric acid, reagent for nitric acid, 554 Phosphoric acid, Carnot’s method, 403 estimation, 354, 362, 403–406, 409–416 French method, 406–409 Halle method, 404, 405 in muck soils, 415 method of Goss, 416–418 Hilgard, 413 Petermann’s method, 409 Russian method, 412 separation from iron and alumina, 414 Phosphorus, 6 microchemical examination, 266 state of existence in soils, 411 Piccini method for nitric acid, 558 nitrous acid, 567 Pillitz and Zalomanoff, method of determining soil absorption, 125 Pissis, nitrate deposits, 16 Polarized light, examination, 261 Porosity, 131 determination, 133 Potash, condition in soils, 367 estimation, 355, 358, 361, 365, 368, 370–372, 375–378, 381, 382 international method, 381 Italian method, 377 method of German experiment stations, 375 Tatlock and Dyer, 382 Russian method, 376 salts, deposits, 20 Smith’s method, 378–381 soluble in cold dilute acid, 370 concentrated acids, 368 Potassium, 18 microchemical examination, 263 Pratt, bowlder phosphates, 9 Q Qualities of soils, 52, 53 R Rain water, method of collecting, 569 preparation for analysis, 569 Raulin, method of estimating humus, 334 potash, 375 Reaction of a soil, 303 Refractive index, determination, 259 Rideal, method for nitric acid, 553 Rocks, aeolian, 38 aqueous, 32 chemical composition, 30 color, 31 composition, 43 decay, 43–52 eruptive, 41–42 kinds, 32 metamorphic, 39 microscopical structure, 28 minerals, 24–26 sedimentary, 35 types, 28 Rohrbach’s solution, 271 Rowland, fall of particles in liquid, 180 S Sachsse and Becker, method for iron, 401–403 Salts, preparation for absorption, 130 Samples for moisture, 74 permeability, 74 staple crops, 75 preparation, 454 for elutriation, 229 Sampling, general directions, 66 method of Caldwell, 71 German experiment stations, 69 Grandeau, 77 Hilgard, 67 Lawes, 80 Official Agricultural Chemists, 79 French Commission, 69, 80 Peligot, 72 Richards, 69 Royal Agricultural Society, 76 Wahnschaffe, 72, 81 Whitney, 68, 73 Wolff, 81 Sandstone, 35 Schaeffer and Deventer, method for nitrous acid, 567 Schloesing method, comparison with Beaker, 241 DeKonick’s modification, 514–516 for nitric acid, 500 French modification, 500–505 of collecting soil gases, 291 silt analysis, 200 Schmidt’s process, 516 Schulze-Tiemann modification, 510–514 Spiegel’s modification, 509 Warington’s modification, 505–508 Schmidt’s method for nitric acid, 539 Schöne’s elutriator, 212 Schulze-Tiemann method, 510–514 Sea-weeds, analysis, 13 Sedimentary rocks, classification, 35 Sediments, separation of fine, 233 weighing, 235 Seeding, method employed, 475 Selective absorption of soils, 122 Separation of silt particles, 272 Shaler, phosphatic limestones, 12 Sieve analysis, classification, 185 German experiment stations, 183 separation, 182 Sievert’s method for nitric acid, 536 Sifting with water, 183 Silica, 4 direct estimation, 424 estimation, 356, 361, 365 Silt analyses, value, 279 analysis, Belgian method, 204 classification of results, 235, 236 interpretation, 251 Italian method, 195, 206 method of Hilgard, 225 Osborne, 196 Schöne, 212–220 methods, 185 Moore’s modification, 192 Schloesing’s method, 200 statement of results, 194 subsidence of soil particles, 186–188 Wolff’s method, 192 classes, illustrations, 258 particles, color and transparency, 278 examination, with polarized light, 261 forms and dimensions, 257 microchemical examination, 262–266 petrographic examination, 266 separation by specific gravity, 268–277 staining, 261 percentage in soils, 249 separates, microscopic examination, 256 Mineralogical examination, 254–278 Siphon silt cylinder, 190 Soda, estimation, 355, 358, 361, 365, 374, 384 Sodium, 22 amalgam process, 537–539 microchemical examination, 263 Soil absorption, importance, 124 method of determining, 125 analyses, special methods, 367–428 definition, 1 extracts, method of preparing, 158 gases, 149, 150 heat, sources, 102 ingredients, distribution, 247 moisture, 132 particles, number, 251–253 standard sizes, 181 surface area, 253 samples, air drying, 88 preliminary examination, 87–93 treatment in laboratory, 87 sampling, general principles, 65 solutions, analyses, 352–367 temperatures, method of determining, 111 thermometry, 111–116 Soils, absorptive power, 117–131 and subsoils, 62, 63 as a mass, 95 carbon dioxid, 293 chemical elements, 2 classification; according to deposition, 52 cohesion and adhesion, 116, 117 color, 95 compact, 90 composition, relation to gases, 282 conductivity for heat, 115 deficient in carbonates, 340 digestion with solvents, 343–352 estimation of carbonates, 337 loose, 89 mechanical analysis, 171–179 method of estimating absorption of heat, 115 nitrifying power, 467 origin, 1, 43 preliminary treatment, 87–93 qualities, 52–53 reaction, 303 selective absorption, 122 specific gravity, 98 determination, 99 unusual constituents, 591–593 volume, 100 weight of one hectare, 102 Solar heat, absorption, 103 Specific gravity, 30 of soils, 98–110 apparent, 101 determination of apparent, 101 heat of soils, 102 determination, 104–110 variations, 110 Spencer, photomicrographs, 259 Squanto, manurial value of fish, 14 Staining organisms, method, 487 silt particles, 261 Stassfurt potash salts, 20 Sterilization, 489 by heat, 490 high pressure steam, 492 Sterilized soil, nitrification, 487, 488 Sterilizing apparatus, 490, 493 oven, 491 Stockbridge, composition of humus, 61 soil moisture, 132 Strontium, microchemical examination, 265 Stutzer’s method for nitric acid, 537 Subcultures, method, 479 Subsidence, physical explanation, 180 Sulfanilic acid, preparation, 562 reagent for nitrous acid, 560 Sulfur, 51 state of existence in soils, 419 Sulfuric acid, estimation, 355, 358, 361 French method, 419 Italian method, 422 method of Berthelot and André, 419 Von Bemmelén, 420–422 Wolff, 422 Surface area, influence on absorption, 123 particles, effect of potential, 172 tension, influence, 174 method of estimating, 157 of fertilizers, 156 T Thenard, humic acid, 62 Thermometry, general principles of soil, 111 Thermostats, 494 Thoulet’s solution, 268 U Ulmic acid, 61 Ulsch’s method for nitric acid, 539 V Von Bemmelén, determination of water, 310 method of humus estimation, 332 Vegetable life, action, 48 soils, 58–60 Volatile matter, estimation, 455 W Wahnschaffe, preliminary treatment of samples, 91 Warington, absorption of potash and ammonia, 120 and Peake, oxidation of carbon, 316 experiments in nitrification, 468–470, 485–488 indigo method, 528–531 Schloesing method, 505–508 Water absorption by soils, determination, 136–143 capacity of soils, effect of pressure, 143 determination at 110°, 306 general conclusions, 313 estimation after air drying, 305 in water-free atmosphere, 149 in fresh samples, 304 soils, determination, 303–314 movement, causes, 155 in soils, 151–169 methods, 151 relative flow, 159 residual amount, dried at 110°, 308 solvent, action, 47 for soils, 343 special examination, 576–583 total solid matter, 576 Way, absorptive power of soils, 118, 120 Weight of soil, 102 Welitschowsky, measurement of percolation, 161–163 Wheeler and Hartwell, analysis of sea-weeds, 13 Whitney and Marvin, method of determining soil temperatures, 112–115 causes of water movement, 155 determination of interstitial space, 134 effect of potential, 172 influence of surface area on absorption, 123 measurement of percolation, 163 relative flow of water, 159 surface tension of fertilizers, 156 theory of subsidence, 180 Williams, machine for mineral sections, 267 -Warington method for nitric acid, 540, 541 Winogradsky, experiments in nitrification, 471–483 Wolff and Wahnschaffe, method of determination of water absorption, 136 determination of coefficient of evaporation, 148 method for silt analysis, 192 preliminary treatment of soil samples, 88 Wollny, determination of water absorption, 142 occurrence of carbon dioxid, 282 Wülfing’s apparatus, 277 Wyatt, phosphate deposits, 8 X Xylic acid, 62 Z Zinc, estimation, 592 TRANSCRIBER’S NOTES 1. Silently corrected palpable typographical errors; retained non-standard spellings and dialect. 2. Corrected the items listed on p. viii. 3. Reindexed chapter footnotes using numbers and table footnotes using letters. 4. Enclosed italics font in _underscores_. 5. Enclosed bold or blackletter font in =equals=. 6. Denoted superscripts by a caret before a single superscript character or a series of superscripted characters enclosed in curly braces, e.g. M^r. or M^{ister}. 7. Denoted subscripts by an underscore before a series of subscripted characters enclosed in curly braces, e.g. H₂O.	351,584	common-pile/project_gutenberg_filtered	73302	project gutenberg	project_gutenberg-dolma-0014.json.gz:353	https://www.gutenberg.org/ebooks/73302.txt.utf-8
TaDr7H6MlNvNXpOp	6: C6) Conservation of Angular Momentum I	6: C6) Conservation of Angular Momentum I - - 6.3: Examples - In the absence of external torques, a system’s total angular momentum is conserved. The angular velocity is inversely proportional to the moment of inertia, so if the moment of inertia decreases, the angular velocity must increase to conserve angular momentum. Systems containing both point particles and rigid bodies can be analyzed using conservation of angular momentum. The angular momentum of all bodies in the system must be taken about a common axis. In this chapter we are going to move away from linear motion and start talking about angular motion. Fortunately, the physics here is exactly the same - angular momentum is conserved in precisely the way that linear momentum is conserved. However, angular momentum is often more confusing for students to deal with. This is actually very understandable, since it requires a few extra notions, as well as being something that we don't experience quite as often in real life. So in this introduction we are going to focus on some of the basic variables used to describe circular motion and momentum, and leave details about the conservation laws to later in the chapter. Just like we measured linear motion with a change in linear position $\Delta\vec{r}$, we'd like to describe rotational motion with a change in angular position, $\Delta \vec{\theta}$. You should be familiar with how to measure an angle $\theta$ (see the left picture below), but the units we use turn out to be important. The physical (S.I.) unit that corresponds to an angle measure is the radian, and is defined (again, see the figure) as \[\theta = \frac{s}{r},\] where $s$ is the arclength and $r$ is the radius of the circle in question. It's easy to see then how many radians are in an entire circle, since that corresponds to an arclength of $s=2\pi r$, so $\theta= 2 \pi r / r = 2\pi$. Of course, there is no problem with saying "an object is rotating at 3 revolutions per minute" - that's still a valid angular speed, it's just not in SI units. If we were going to calculate something, we would want to convert that into radians per second; let's do that real quick as an example: \[\frac{3\text{ rev}}{1 \text{ min}}\left(\frac{2\pi\text{ rad}}{1\text{ rev}}\right)\left(\frac{1\text{ min}}{60\text{ sec}}\right)\simeq 0.314\text{ rad/s}.\] The conversion factors here are represented as factors that you multiply the initial value by - there are $2 \pi$ radians in one revolution, and 60 seconds in one minute. So now that we know how to measure the angular position, how do we find the angular version of linear velocity, $\vec{v}=\Delta \vec{r} / \Delta t$? That's simple, since we are now just measuring the displacements in angles, and we get angular velocity 1 $\vec{\omega} = \Delta \vec{\theta} / \Delta t$. The rotational speed $\omega$ is defined the same way as the linear speed, as the magnitude of this vector quantity. So that seems easy enough, but the challenge comes when we try to go back and forth between linear and rotational quantities. Let's try to do this with the ferris wheel shown in the figure on the right. This is "The Great Ferris Wheel", built for the 1893 World's Fair, and is 140 feet (43 m) in radius. When we say "the wheel is moving at an angular speed of 1 rotation a minute", that applies to the entire object - specifically, points A and B (which is halfway out to the edge) have the same angular speed ( why? ). The same is not true of the linear speeds of different points on the wheel. For example, over one rotation, point A travels a distance $2 \pi (43\text{ m})\sim 270 \text{ m}$, while point B travels $2 \pi (43/2 \text{ m})\sim135\text{ m}$. Therefore, the linear speed of A is greater then the linear speed of B, because A is traveling a longer distance! We picked one rotation for convenience, but it would apply equally to any time period you chose. 1 Notice that we haven't talked about how to assign a direction to this velocity - all velocities have directions! You do this with "the right hand rule", which we will talk about later in this chapter.	915	common-pile/libretexts_filtered	https://phys.libretexts.org/Courses/Merrimack_College/Conservation_Laws_Newton's_Laws_and_Kinematics_version_2.0/06%3A_C6)_Conservation_of_Angular_Momentum_I	libretexts	libretexts-0000.json.gz:11398	https://phys.libretexts.org/Courses/Merrimack_College/Conservation_Laws_Newton's_Laws_and_Kinematics_version_2.0/06%3A_C6)_Conservation_of_Angular_Momentum_I
L92L7i9z_XdHruIb	Reading and Writing in College	43 Remix: “The Monkey Bars Are Burning” [Anonymous] Instructor Juliette Holder ENG 1013.06 5 December 2022 Cover Letter For this remix assignment, I reinvented my learning narrative essay entitled “The Monkey Bars Are Burning” into a visual mode by creating a painting. The essay is about how my grandfather helped me learn how to communicate and how I learned to communicate in a world without him. The essay deals with grief and isolation that comes with the loss of a loved one. My audience for this Multimodal Remix is fellow artists or those who appreciate art, which differs from the original audience; this audience is more casual and allows for a looser interpretation of the artwork. Art, specifically painting, is something very important to me. There is a line in my essay that states, “Art is an experience in which a person can relay their truths; a cathartic goodbye to whatever may haunt their lives.” I knew as soon as I was given this project that I wanted to do an art piece as to how I reconciled the loss of my grandfather. The process for creating this art piece first involved sketching. I sketched out thumbnails and listed out the materials I would need to find amongst my art supplies or go out and buy. One of the first challenges I faced while collecting my supplies was deciding what size canvas would be the most appropriate. I already had smaller canvas panels, but I concluded that the panels would be too small for the painting to be as effective in getting my message across. These are big, scary, feelings I was trying to express, which warranted a big, scary canvas. I went to a few different art stores before winding up at Walmart where there was a 24 x 20-inch canvas just waiting for me. During the time in which I was scouring various stores for art supplies, I had also contacted my parents and asked them to send me a few copies of my grandpa’s newspaper, the Falfurrias Facts, so that I could use it to create a border around the canvas. Collaging the edges of my canvas is a stylistic choice that I make with all of my art pieces and has become a staple of mine over these last few years. I find that it helps set the tone of the painting or art work. Overall, the materials I used were acrylic paint and cheap, horribly made paint brushes, and news paper. After gathering all the materials I would need I began to work on painting. I went through many phases while working on this piece. I sketched out a hand reaching out toward a monkey bar; however, this metal bar is not what it seems. The monkey bar is burning, and the Spanish phrase “si se puede” is inscribed into the scalding metal. The imagery I was trying to create was one of the most difficult things about this painting. To create the image that the monkey bar was burning required a lot of strategic thinking in the color’s placement. Same goes for the hand—I had to ask myself every time I worked on the painting: is this really what a hand looks like? I had to stop and ignore the hand for a while before coming back to it. Now creating this piece was incredibly fun, but because this piece was about something so personal, I just had to get it right. I had to make very specific choices when it came to this painting, from colors to imagery. One of the first decisions that I made once I started to actually work on the painting was what pieces of the newspaper I wanted to include in the collage. I wanted to mimic the anecdotes being told in my essay through this art piece, and in order to do that, I had to be strategic in what the newspaper clippings were telling my audience. I chose clippings from the obituary section. Death in bold letters was to be pasted across the edge of the canvas in reference to the meaning of this painting, grief. I also included ads from H-E-B and the Falfurrias Nursing & Rehabilitation, which are locations I include in my essay. The latter was where my grandpa stayed while he was in hospice. I also included black and white pictures of my grandfather on the collaged border. The stylistic choice of collaging the edges allows for me to create this storybook feel. I want the viewer to understand that there is a story being told, and the border allows for the context of the main imagery. When looking at the subject of the painting in relation to the context, I wanted my viewers to understand that this is sad or concerning. I really wanted to convey this concept that I would reach out for something that might hurt me. Grief can be very difficult to process, and when I was dealing with the loss of my grandfather, I wanted nothing more than to see him again, to hear him tell me I could do it: si se puede. I just wanted to get back on those monkey bars one more time. I painted the monkey bars green and used a lot of green in my painting as that is the color that reminds me of my grandfather. The color green is a signifier of hope and growth, which greatly reminds me of my grandfather as he had always been a source of hope and positivity for my family growing up. Another detail I wanted to point out was the red string around the wrist. In Latine culture, a red string is often worn around the wrist or ankle to ward off evil. I often wear a Mal de Ojo bracelet in my everyday life. In the painting, the Red string is untied, slowly slipping off. This symbolizes the gradual loss of grandfather, someone who guided and protected me. I really enjoyed composing in these modes because overall I really enjoy painting. I’ve been actively painting since I was in 7th grade, and to combine a passion of mine with a personal story is something I’ve always loved doing. I find it is much easier to tell a story through art than in any other mode, so at the beginning of the semester, I was troubled with writing my learning narrative essay in a way that conveyed exactly what I was feeling. Now, with my multimodal remix project, I feel very confident that I can fully extend on those ideas. This project has definitely changed my view on how words can be used and extended past just writing an essay.	1,453	common-pile/pressbooks_filtered	https://pressbooks.pub/readingandwriting/chapter/remix-the-monkey-bars-are-burning/	pressbooks	pressbooks-0000.json.gz:86011	https://pressbooks.pub/readingandwriting/chapter/remix-the-monkey-bars-are-burning/
-b4vIth-1mFTX2V3	Notes on school observation; the physical nature of the child, by Bird T. Baldwin...	EXCHANGE Cultivated mind is the guardian genius of democracy. . . . It ifi the only dictator that freemen acknowledge and the only security that freemen desire. NOTES ON SCHOOL OBSERVATION This Bulletin forms a part of the introduction to a course in School Observation which the author is giving in The University of Texas. The course may also be taken through the Extension Department of the University by principals, supervisors, and teachers who wish to carry out observations in connection with their school work. All reports and answers to the questions will be evaluated and checked by the instructor. Similar bulletins will be issued on Instinct and Play, Fatigue, Individual Differences, Discipline, and the Recitation. A series of bulletins on Practice Teaching will be published later. All of these bulletins will aim to deal with fundamental problems in an elementary manner. Teachers who wish to take this work should register in the Department of Extension. ENVIRONMENT. It is now conceded by all educators that it is very important for teachers to have a rather complete knowledge of the physical growth of school children, but the important practical problem is, "What shall the teacher observe and how shall he make the observations sufficiently definite and accurate to be of help to both teacher and pupils?" Let us first select the phases of the physical nature of the child which may be observed by any teacher who is willing to use a little perseverance and time. They are> growth in height and weight; chest girth; breathing capacity; head girth; cephalic index; symmetry of body; posture; the teeth; enlarged tonsils; adenoids; nasal obstructions; nutrition and sense defects. With a few exceptions observations may be made in a general way without personal inspection and examination, but there is no reason why a teacher should not make personal individual inspection of every child in his room and construct a record card for the sixteen headings outlined in this bulletin. The observational method of studying children which is here recommended is one that may be made just as scientific as the observer's training and opportunities permit. . It is a method which takes the physiology into the schoolroom and applies it to practical everyday problems; the directions offered are those which can be followed by the average trained teacher. The advantages of such a method are at once apparent because the material is always at hand, observations of a very practical nature may be undertaken, and the teacher is led to adjust her instruction to the individual needs of pupils. The chief difficulty involved in the method is that teachers at first find it difficult to observe their children and teach them at the same time, but principals, teachers and student observers, who have carefully undertaken the work with prepared outlines, claim they soon become very accurate observers and that there is no interference with their actual work of instruction. They learn to observe the children as they pass to and from classes, during the study period, during the intermission or rest pauses, or during special periods .in the day set aside for observing, measuring and testing. As a result teachers are soon led to see for themselves that children differ greatly from each other and from adults, and, therefore, different standards and methods are applicable. Attention is drawn to the physical and mental development and directly to the learning process. In short, the teacher is brought face to face with the problem of how children learn, which is the center of reference for all good teaching. Educational psychologists have necessarily been interested in the relationship of mind and body, but it is only recently that they have extended their study beyond the senses and noted how physical abnormalities and defects condition mental development. One is also surprised to find how little the average teacher and student observe in regard to tho physical nature of the child. Principals and teachers 6 Bulletin of The University of Texas who are college graduates with experience are found to be unable to measure children correctly, note the common signs of abnormalities or test for the acuity of the senses. The observing teachers and students will wish to supplement this general outline with some further information on the work of the medical inspector or physical director and, also, to consult freely the classified list of appended references. The main purpose is to help teachers to detect gross deformities and pronounced physical defects, to appreciate the educational significance of the relation of the body to the mind and to develop the desire to appeal to expert authority when conditions seem to require it. In no case should the teacher assume the role of the physician or the expert. This syllabus, as outlined above, is designed for students attending class exercises in training schools and universities or for teachers actively engaged in school work. The observations are divided into two groups : (A) those which are made by means of personal inspection, examination, and measurement, and (B) some general observations to be made in the school room or in the laboratory. Either group of observations may be pursued independently, but the one naturally supplements the other. No elaborate apparatus is necessary; the aim has been to keep the scope of the work within the experience of a trained teacher. The interrogative form of suggestion has been used in connection with each topic in order to arouse definite, specific questions in the mind of the observer. In nearly all cases a few answers to these questions have been given. It is not expected any student or teacher will be able to answer all the questions or to include all the observations after one or two visits. Some of the questions require consecutive observations from day to day, and a few refer to exceptional conditions. All are practical and each has been based on active schoolroom conditions. Careful notes should be recorded in a permanent note book in such a manner that they will be self-explanatory and accessible for future reference. The following order is suggested: (a) the name of the observer; (b) the name of the school; (c) the grade; (d) the subject; (e) the size of the class; (f) the time of day; (g) the date ; (h) a brief statement of the purpose of the observations, and a careful written summary of the results. Record blanks or cards similar to the one given on the last page of this Bulletin should be made so that consecutive records can be kept for the entire school life of each individual; these should be kept within easy access of the teacher's desk for ready reference. I. HEIGHT. II. WEIGHT. Height and weight are among the best indices of growth and nutrition. Observations lead us to conclude children vary according to race, sex, heredity, and stae-e of development. The latter, which is of direct concern to the teacher, varies in accordance with facts which may be observed. The growth is most rapid during- the first year of childhood, there is a slight acceleration at seven and a decided increase from twelve to eighteen, with marked sex differences at adolescence, the increase appearing with girls earlier than with boys, and the rapid growth and advent of maturity appearing first with tall boys and tall girls. (For details see table and charts on pages 8, 10, and 11. The averages here are a trifle above those found by nearly all other investigators. The children were niide in all cases.) The most rapid growth period for boys who are taller than the average is from 13 to 14 years of age, and for those below the average 14 to 15 years of age ; for girls above the average the most rapid growth is between 11% and 12% years of age ; for those below, between 12% and 13% years of age. These periods of adolescence are the periods of greatest range of differences in height for both boys and girls. The results of my investigations show marked individual differences, and prove that a composite curve of average measurements from different groups of individuals cannot give an accurate conception of growth, since the characteristics of different types of the same chronological age, but different physiological ages, tend to obliterate each other. (These conclusions, Chart I and Figures II and III are from a preliminary report of an investigation which has been extended and will be published by the United States Bureau of Education, Washington, D. C.) It is more difficult for teachers to get the weight of- children than to get their height, since scales are not often available. The weights of children fluctuate a great deal more than the heights, but in general the curves of weight follow the curves of height. The lower forms of mentally deficient children, such as idiots, imbeciles and feeble-minded, are larger than normal children at birth, but usually fall below the normal children during the school period. TABLE I. HEIGHT AND AGE DISTRIBUTION AND WEIGHT AND AGE DISTRIBUTION, UNIVERSITY OF CHICAGO ELEMENTARY AND HIGH toCHOOL AND FRANCIS W. PARKER SCHOOL CHILDREN. A. INDIVIDUAL OBSERVATION AND INSPECTION. In order to have a basis for intelligent comparison every teacher should accurately measure and weigh a few children. The height measurement may be taken with a measuring rod or tape tf no stadiometer is accessible, deductions being made for the heels of the shoes. The person measuring should be careful to see that the child is standing straight, with heels together, and heels, upper part of the back and head against the measuring rod, and in a natural position. Measurements will vary a little at different times of day and with different measurers; try to keep a standard method of procedure as far as possible. The measurements may be taken either In the English or French system of units, but the latter is more easily used in making comparative studies. If no scales are available the teacher may as a last resource ask the child its weight; this, as a rule, is not a reliable source of information. Deductions should be made for clothing if the child is weighed. physical director and with the norms in the chart on page 8. 1. Give measurements for height. For weight. Compare in tabulated form with the norms on the preceding page and note whether the child's growth is arrested or above normal. In making such comparisons keep in mind such modifying factors as race, heredity, environmental conditions, etc. CURVES OF INDIVIDUAL GROWTH IN HEIGHT AND WEIGHT. These charts represent graphically the growth in height and weight of 14 boys and 11 girls. The charts were plotted on large white sheets of linen paper, six feet by three feet, and were reduced, when photographed, to the size printed in this monograph. Originally 10 centimeters in the vertical scale equalled 10 centimeters in height, and 10 centimeters horizontally equalled 12 months in time; 10 centimeters vertically also equaled 10 pounds in weight. The Roman numbers at the beginning and end of the curves refer to individuals. There are many characteristics to be noted in these charts that are common to the growth of children in general, i. e., the advent of pubescent acceleration is directly correlated with the initial height at this period. There is a parallelism in growth which is so uniform that if the relative position of a child is known in reference to a given median at a given age it is possible to prophesy quite accurately the height to which the child will grow at any age after this and before eighteen years. The majority of normal children grow in accordance with the general trend of these curves; there are some children whose growth is more irregular than these charts would seem to indicate; there are others whose growth rates are more uniform with no acceleration at adolescence. There is a moderate decrease in increments after six or seven years of age, until the pubescent stage which varies in advent in accordance with the height of the individual. Follow each curve for height and see how individuals differ. Compare the growth in height and weight for each individual. Compare boys and girls. Number 2 in Fig. II is a tall, heavy boy. Number 1 in Fig. Ill is a tall girl who weighed 150 pounds when 12 years three months old. References: Hastings, W'm. W. A Manual of Physical Measurements, Boys and Girls, with Anthropometric Tables for each height of each age, from five to twenty years. Macmillan Co., N. Y. III. CHEST GIRTHS. IV. LUNG CAPACITY. It is highly important that teachers pay more attention to the development of the pupil's lung capacity, not only because there is a close correlation between physical growth and breathing capacity, but because the breathing capacity may be greatly increased through proper exercise. This may be accomplished through out-door gymnastics, -through systematic breathing exercises, and through correct posture. At adolescence, boys begin to have a strikingly greater capacity than girls, and the girls need special attention at this period. These measurements are so important that they are frequently referred to as indices of vital capacity. It is important the tape be kept uniformly taut around the chest just below the arms. The child should be asked to take a deep, full breath in order to get the measurement for forced inhalation and to exhale as completely as possible in order to get the measurement for forced exhalation. The lung capacity of girls falls below boys at twelve years of age; future development may be impaired by dress, posture, etc. Lung capacity is tested by means of a spirometer. If a spirometer is not at hand, a comparative method may be devised which may suggest, together with the measurements of chest expansion, unusual conditions of lung capacity. For example, try the blowing out of a wax taper or the blowing over of a light block at distances which have become standardized through experiments on normal children. These are crude and inaccurate tests, but they may help to suggest unusual cases. 3. Compare the measurements of different children at all ages and give your conclusions, taking into consideration the child's experience in taking deep breaths, the teacher's experience in measuring, and the deductions for clothing. V.. HEAD GIRTHS. VI. CEPHALIC INDEX. There is no direct evidence that the size and the shape of skull ar« closely related to intelligence, but there are limitations byond which the relationship is quite apparent. Extremes are found among mentally deficient children and are known as microcephalic, or very small Bkull, and macrocephalic, or very large skull, and hydrocephalic, or progressive development of the skull after normal growth. The circumference of the head is as a rule greater for boys than for girls. The writer and his students have observed some heads as small as sixteen inches in circumference and others as large as twenty-six inches. The average circumference of the heads of American boys and girls is about as follows: For boys at 6 years, 20% inches; for girls, 19 4/5 inches; for boys at 9 years 20 3/5 inches, for girls 20 1/5 inches; for boys at 12 years 21 inches, for girls 20 4/5 inches; for boys at 15 years 21 3/5 inches, for girls 21 1/5 inches; for boys at 18 years 22 1/5 inches, for girls 21 3/5 inches. The cephalic index is the proportion of the greatest width (bi-parietal diameter) to the greatest length (antero-posterior diameter). If head calipers are not at hand rough measurements may be made by means of a ruler and tape. The indices for long heads (dolichocephalic) are below 78 per cent, and are found among English, Irish, Negroes, etc. The broad head (brachycephalic)' has an index above 80 per cent, and is found among Germans, Russians, etc. above the eyes and ears. 1. List all measurements made and compare them with the normi that have just been given. (We recently found a very intelligent boy of 9 years with a head circumference of 20.75 inches and a cephalic index of 68.52 per cent.) Most children and adults do not have symmetrical bodies. Observe your children and see if you can find some whose bodies are symmetrical and others whose bodies are not symmetrical but asymmetrical. Do some have one shoulder lower than the other? Posture is the result of habit and it is the teacher's function to correct habits of improper bodily posture and movement. Do the children stand correctly ? Walk correctly ? If not, how may these defects be corrected? There are two ways- — vigilance on your part and correct desks. If the desks are not adjustable and adapted to the age of the pupils do not let your principal or directors rest until they get such desks, and then do not fail to see that each pupil is in the proper desk and that each desk is readjusted at least twice each term. It is very important that the teachers in the middle and upper grades of the schools pay more attention to the habits of posture for these are habits that the student may carry through their entire life, and they will be a great benefit or injury to the health and welfare of the child in general. 6. Sketch a desk which will satisfactorily permit of the three position! noted in the preceding question. (Make the desk and chair adjustable in height, forward and backward, and the top of the desk adjustable for a flat surface of varying angles.) IX. TEETH. It is estimated 85 to 95 per cent of school children have varying degrees of defective teeth. The temporary teeth are lost between the ages of six and twelve. There are no bicuspids in the temporary set, and when they appear at the age of six or seven they are frequently mistaken for temporary teeth and extracted or neglected. Table II. Number and Location of Permanent Teeth. Decayed teeth are injurious to the pupil's health and detract much from the personal appearance. You may ask the child to open his mouth, note the number of decayed, protruding and irregular teeth, and if there is no medical inspector you should notify the principal or parent that attention to the child's teeth at this time will be very beneficial. Parents are usually glad to receive any information that will be of direct benefit to their children, and if teachers use common sense and politeness in notifying them of defects, these suggestions in nearly all cases will be gladly received. X. ENLARGED TONSILS. XI. ADENOIDS. Hypertrophied tonsils are found not only to be the starting point for certain diseases, but sometimes direct conditions of mental defects. They are almost invariably associated with adenoids and the best authorities claim that at least 5 to 10 per cent of American children have them. They frequently produce nervous troubles and may lead to inattention, lack of application, etc. No teacher should ever undertake to assume the role of physician in prescribing remedies or operations. Her function is to try to learn how to recognize defects and deformities and, providing these are not due to schoolroom habits which can be corrected, report them to the proper authorities for correction or treatment. In order to observe the enlarged tonsils, -you ask the child to face the light, open his mouth, put out his tongue and say "ti." This will throw the back part of the tongue down in such a way that the throat is exposed. Try this with several children and you will soon learn to detect enlarged tonsils, which are large irregular glands on either side of the throat, sometimes almost closing it. Compare the throat with the sketches in your physiology books. Do not use a tongue depresser under any conditions unless you know it has just been sterilized. The symptoms or signs of adenoids are not differentiated from hypertrophied tonsils. Adenoids grow in the vault of the pharynx up and behind the soft palate and vary greatly in size. (See sketches, natural size.) They are difficult to observe directly and can seldom be seen with the throat mirror or felt with the finger. Under no conditions should the teacher attempt either of these methods. For the common signs of adenoids see the questions and suggestions on the following page. Naso-pharyngeal obstructions, due to adenoids, frequently affect hearing. Teachers should know the common symptoms and evil effects and have the physician consulted. The removal of adenoids is a minor operation in most instances, and should be done if recommended by a thoroughly competent physician or specialist. TONSILS. 1. Are there large irregular bunches of glands on either side of the throat, almost closing it? If so, the tonsils are enlarged. (Compare with sketch and allow for the age of the child, degree of exposure and other modifying influences.) B. GENERAL OBSERVATIONS. Several of the questions asked under A. may be continued under thl» division of general observations. Compare doubtful cases with the children in the accompanying photographs who represent type cases. McMahon, J. P. Necessity for Annual Systematic Examination of School Children's Eyes, Ears, Noses, and Throats by School Teachers. Wisconsin Med. Jour., Dec., 1907. XII. NASAL OBSTRUCTIONS. These are, as a rule, associated with enlarged tonsils and adenoids, but there may be other causes. Defects of nose and throat are among the most numerous, if we except those of the teeth. XIII. NUTRITION. An average teacher will have very little difficulty in observing marked cases of poor nutrition among school children, for such children are usually under size, have a pale and sallow complexion and are very easily fatigued. Try to find out what these children eat for lunch. See whether they have regular hours of sleep and see that they get proper exercise and plenty of fresh air during the school period. certain the causes and effects. Observe for rhachitis, where there is insufficient amount of limes and phosphates in the bones. Note crooked legs, box-like head, stooped shoulders, curvature of the spine, pale skin, "rickety rosary" of ribs. This disease is found mostly among poorer children and is not generally considered hereditary. XV. VISION. The number of weak and defective eyes rapidly increases during school age. Eye strain is very prevalent with children, and it is believed such pupils are handicapped intellectually, but we have no conclusive evidence they are retarded. The defects increase with age. All teachers should be able to observe the eyes intelligently, test the acuity of vision, note pronounced cases of astigmatism, squint, color blindness, and the lack of functioning of the grosser parts of the retina. The eyes should be examined annually by the teacher, also by an oculist in cases where probable defects exist. In many of our best school systems teachers are required to be able to test the children's vision. You should be sure to see that at least the conditions in your schoolroom are the most favorable possible for the protection of the eyes. Never have the pupils face the light under any circumstances during their study period and not during their recitation period if it is possible to avoid it. The light should always come over the left shoulder if this can be arranged. Hold a pencil over a sheet of white paper on the top of each child's desk and see whether or not the shadows interfere with the child's seeing the letters as he writes them. If the desks face the wrong way, see the principal or directors and have them placed properly. This rquires a little effort on your part, but it is of great importance to the child. Observe the pupillary reflex by asking the child to look at a light window. Place the open hand over the open eye, then draw it rapidly away and note the rapid diminishing of the size of the pupil. If the reaction is slow or not noticeable the muscles may be impaired. Ask the child to look at a distant object. Note external or internal squint (strabismus). Cover one eye and then the other and note the effect. External squint is rare among children. ACUITY OF VISION. As the eyes of children readily accommodate themselves to extreme conditions, it is almost impossible to detect defects in the acuity of vision without making special tests, which all teachers should be able to do. The best tests in common use are Snellen, Queen, MacCallie. In the normal, or emmetropic, eye the rays of light are brought to a focus on the retina; in the far-sighted, or hypermetropic, eye the rays of light meet if continued behind the retina; in the near. sighted, or myopic, eye the rays of light meet before reaching the retina, since the eye is too long. The myopic eye is not fatigued easily; hyperopia is frequently accompanied by headaches. Secure a standard test card for determining the acuity of vision. The following directions printed on the Snellen card are those formulated by Dr. Allport and are among the best. They are as follows: as he can, first with one eye and then with the other. If the child can read the majority of the letters with a line marked XX, the result should be recorded as 20/20. If he fails to read these and can read the majority of those above the result is recorded as 20/30, which means that this eye at twenty feet can see what the normal eye sees at thirty feet, and so on up the scale. Children who have one eye 20/30 or 20/40 may not know it. Astigmatism. This may be tested with cards, but constant headaches and signs of eye strain on the part of the child are for the average teacher the most satisfactory indications. Astigmatism may be due to asymmetry of the cornea or .of the lens. All eyes are slightly astigmatic and compound forms in connection with myopia and hyperopia are most common. 2. Question for headaches, pain in eyes. 3. Are the eyelids inflamed? Is the head bent forward when reading? Is the vision for near and far objects indistinct? Does the child hold its head to one side when reading? Asthenopia. Observe for possible signs where the eyes become easily fatigued for near and distant objects. Such a condition may be muscular or accommodative, and is closely related to hypermetropic eyes. Color Blindness. Test with light green, purple and red. When picking shades and tints resembling green, what will the color blind person select? Give the results for the others. Use Holmgren's tests. XVI. HEARING. Satisfactory apparatus for testing the hearing of school children is expensive, but you may be able to detect any marked defects by asking the child to close his eyes and holding a watch at varying distances from each ear. The essential point is to see that the room is perfectly quiet and that after you have tested several children a standard or normal distance at which the tick can be heard be determined. Another simple method of testing hearing is to have chil^ dren sit at certain distances from the teacher's desk while he is whispering words or asking certain questions in a whisper. uses conversational speech. The essential points for the teacher to keep in mind are : try to acquire a uniform whisper ; see that every pupil is tested for different distances and compare the pupils with one another, since the results are always relative. The test may be used with any grade of pupils of different degrees of intelligence.- The whisper test is as follows: Place eight or ten children in a row with the first child ten feet from the examiner with one ear toward the examiner. Let the other children assume the same relative "position. The examiner then whispers the numerals from one to twenty, or pronounces in a whisper twenty one-syllable words. After five words have been pronounced, or five numerals called, have each child move up one place, and the one at the head pass to the other end of the row. Each child should be provided with paper and pencil in order to record the words. After all have been tested four times for one ear, have each turn the other ear and repeat the experiment. If a child does not hear all the words when at the nearest distance, he should be tested again and referred to the medical examiner or to his local physician for treatment and further diagnosis. Try this test; it is not difficult, and, if it sounds too complex, try it with one child at a time. The writer would, however, recommend that every city school system purchase a Seashore Audiometer, which is described in the University of Iowa Studies in Psychology, 1898, II: 158-163, and may be purchased from C. H. Stoelting Co., 121 N. Green St., Chicago ; or a Pilling McCallie Audiometer, Pilling and Son, Phi] a. It is claimed about 5 per cent of school children have imperfect hearing. Test the acuity of hearing with a watch. Outline necessary precautions. Why is the whisper test better? How may a "check" be devised? Why should the pupil's eyes be closed?	6,425	common-pile/pre_1929_books_filtered	notesonschoolobs00baldrich	public_library	public_library_1929_dolma-0001.json.gz:716	https://archive.org/download/notesonschoolobs00baldrich/notesonschoolobs00baldrich_djvu.txt
GYSZ-xZbyFUIkPhp	Reorganization by F.E. Clark.	The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming, are checked below. distortion le long de la marge intdrieure Blank leaves added during restoration may appear within the text. Whenever possible, these have been omitted from filming/ II se peut que certaines pages blanches ajoutdes lors d'une restauration apparaissent dans le texte, mais, lorsque cela 6tait possible, ces pages r.'ont pas 6t6 film^es. L'Institut a microfilm^ le meilleur exemplaire c"'il lui a dt6 possible de se procurer. Les details e cet exemplaire ^ui sont peut-dtre uniques du ^wint de vue bibliographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification dans la mdthode normale de filmage sont indiqu6s ci-dessous. 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Les exemplaires originaux dont la couverture en papier est imprimis sont fi!m6s en commenpant par le premier plat et en terminant soit par la dernidre page qui comporte une empreinte d'impression ou d'illustration, soit par le second plat, selon le cas. Tous les autres exempiaires originaux sont fiim^s en commenqant par la premidre page qui comporte une empreinte d'impression ou d'illustration et en terminaut par la dernidre page qui comporte une telle emprainte. Un des symboles suivants apparaftra sur la dernidre image de chaque microfiche, selon le cas: l9 symbols — ► signifie "A SUIVRE", le symbols V signifie "FIN". apon d Maps, plates, charts, etc., may be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames as required. The following diagrams illustrate the method: Les cartes, planches, tableaux, etc., peuvent dtre film6s d des taux de reduction diffdrents. Lorsque le document est trop jrand pour dtre reproduit en un seul cliche, il est film6 d partir de I'angle supdrieur gauche, de gauche d droite, et de haut en bas, en prenant Ee nombre d'images n6cessaire. Les diagrammes suivants illustrent la mdthode. REORGANIZATION. I. Do not reorganize your society, unless there is real need of it. If almost all your members are faithful to their vowc, let the Lookout Committee see the few delinquents, and in a kindly and brotherly spirit bring them back to their duty, or show them the harm they are doing while active members, and induce them to leave the active membership, if they are incorrigible. In most societies there is no trouble, if we may believe the glowing and enthusiastic accounts that come to us at the central office, from pastors and workers all over the country. It is very rarely indeed that we hear of any serious trouble, or of any society that has been given up. So far as we can learn from statistics, more churches and Sunday schools, organized within the past seven years, have died, than Societies of Christian Endeavor. There is a vitality about these organizations that is particularly gratifying. They are doing a better and better work every month. As the principles are better understood the importance of the element of obligation is also understood, and the fact that the Society was horn and exists to bring the young people into the church and keep them at work for the church, has vastly increased the confidence of pastors and churches in the organization. Still it would be strange if there were not some cases of partial failure in accomplishing the end proposed, t. e., in the words of the constitution, "to promote an earnest Christian life among the menibfin. and to make them more unefiil in the service of God." Anything Icrk thiin the highest succeRs is purtini failure; and manv societies which are doing a good work might do a much better one. What is the trouble.' <i. It may be that some of the active members, in the first place, joined too hastily, not fuUv understanding what they were doing, or realizing their obligations. Then let all the active members sign the Reorganization Card, renewin.-; their vows. />. It may be Mat a spirit of coldness pervades the whole church, which the young people have caught, and that some who signed the constitutioii oiiginally in good faith no longer keep it. If earnest words of counsel do not avail, apply the same remedy as above, and have the active membership consist of active members who have some little heroism and Christlikeness in their characters. f. It may be that the young lady members have been discouraged from taking part in the meetings, or tb-ough some false ideas of modesty have been willing to do .lothing but repeat verses. Then let it be understood that in Societies of Christian Endeavor there are eyitnl lightf and egunl rrspoiisiIn'lities and equal privileges for all. d. It inav be that the pastor and older church-members, not understanding the organization, have been suspicious of the society, and have unintentionally or otherwise weakened it. Do not show any resentment, which will only make matters worse, but sbf^w by loyalty and faithfulness to every duty in the church, tl. . the society is no separate organization, but is a training school, which exists simply to make you more useful in the church. So far as you can, obliterate the line between "old and young." lame Christian Endeavor, the society has «ot switched o« on some de ck ,„• ..Social Knde«vor"or -Literary Kndeavor or Musical Endeavor " or - Debating Society Kndeavor." I. .... Ret U ba k on the main track again, and ren,en,.,e. that ^-'f;^^;, nrcs, as en.bodied in the prayer-mcet.ng and the comm.tttc work must be paramount. .meetings are languishing, .hen change your const.tut.on. unt /i contains the muin features of the Model ^'"-tmuum wh d. is adopted by nine-tenths of the societ.es ' -""Khout the w o d. ■and which contains this prayer-n.eet.ng clause : txery ..ctMe menU,er is expected to attend every weekly prayer-meetmg, un. less detained bv some absolute necessity, and to take -'"'« Part however slighi, in every meeting." 'Absolute "-«-'^J ^l'; revised Model Constitution defines as - son,e reason wh.ch the young disciple can conscientiously give to the Master, Jesus Christ, for non-attendance or non-participation. Then when you are sure that all the n.embers understand the constitution, and know what .hey are doing, give out cards like the following, and have for your active members only those who are willing to sign them conscientiouply : Active Membership Pledge. Trusting in the Lord Jesus Christ for strength, I promise Him that Iwi I try to d<. whatever He would like to have me do that 1 3 IL to Ilim and read the Bible every day and that ust so far as l" know how, throughout '"y ^^hole life, w.l IriJr "'! ? '"""■" "'"'"•'"'' ^''" "'' ""' <■"">"■"'• «"'' who n c .ealU „ hindrance to the npiritunl life of all present, then K"ve to every active member the following ;	1,746	common-pile/pre_1929_books_filtered	cihm_27451	public_library	public_library_1929_dolma-0000.json.gz:3117	https://archive.org/download/cihm_27451/cihm_27451_djvu.txt
HILWJfRKyTrPx0BP	Library and Information Studies	9 Field Trip and Discussion Board Assignment: Exploring Your Local Library This assignment provides you the opportunity to visit a local library near you of your choice, and then you will share your experience with your classmates in this discussion forum. Please read the following guidelines and instructions carefully. As this week’s “Determining Information Needs” tutorial explained the different types of information sources necessary to consider when doing research (books, articles, websites, etc.), it is also important to know where you can go to actually find these information sources. A great place to start is your local library! If you live in Orange County or any other major metropolitan area, you have access to many different libraries, including public libraries, college and university libraries, and special libraries (e.g., Orange County Public Law Library). Even though we will be using Santa Ana College’s Nealley Library and its many online resources for much of our research this term, you are encouraged (and it is good practice as a scholar) to use other libraries around you. As library collections differ, using multiple libraries exposes you to a variety of resources, making your research process more diverse and well rounded. In addition to the information resources available through your local libraries, you may be pleasantly surprised to learn about the community services and resources also available. Getting Started: - Select a library to visit near where you live: You may visit a public, academic (college/university), or special library. If you live near Santa Ana College, you are welcome to take this opportunity to visit the Nealley Library. If you are not sure where your local libraries are located, you can use Google Maps in the following way: Go to www.maps.google.com and in the search box, type “libraries near [insert your address]”. You are also welcome to contact me individually<EMAIL_ADDRESS>for assistance with finding a library near you - Plan your visit: Keep in mind that many libraries have limited hours and may even be closed on certain days, so visit the library’s website or call ahead to ensure you are planning to go when the library is open. - During your library visit, have fun exploring and take notes on the following: - Which library did you visit? - What is the physical address of the library and what is their website address (URL)? - What are the library’s hours? - How can you receive research assistance (in person, online, etc.)? - What types of information sources does the library offer? Include physical and online resources — e.g., print books, audiobooks, magazines, online databases, etc. You will need to look at the library’s website as well as look around the actual library building. Please be specific in your list here. - What types of community services does the library offer? For example, most public libraries offer storytimes for children and homework help for students. Again, you will need to look at the library’s website as well as look around the actual library building to find information about the different services the library offers. Again, please be specific in your list here. - How do you feel your local library can help you as a student, professional, and as a lifelong learner? IMPORTANT: Please do not ask a librarian or library staff member to answer all of these questions for you. The point of this exercise is for you to begin exploring what your local library has to offer. If you have a specific question regarding a library resource or service you learned about during your exploration it is fine to ask a librarian or library staff member for assistance. We just want to be respectful of their time and the many other patrons they serve. - Post your findings to this week’s discussion board: Share your answers for 1-7 above in the discussion board forum for this assignment. This way, we can all learn from each other about the offerings at different libraries in the area. Please also respond to two of your classmates’ posts (3 sentences minimum per response). - Extra Credit (optional): Spread the love for your local library and receive 5 extra credit points by taking a family member, friend, or any other special person in your life with you on your library visit. To receive the extra credit points, please note who you brought with you in your discussion post. Also, consider taking a picture of you with your person at the library you visited, and add the photo to our class wiki, “Libraries that Inspire Us.” This assignment is worth 20 points and is due by 11:59pm on Sunday.	999	common-pile/pressbooks_filtered	https://library.achievingthedream.org/saclibrarystudies/chapter/field-trip-and-discussion-board-assignment-exploring-your-local-library/	pressbooks	pressbooks-0000.json.gz:9880	https://library.achievingthedream.org/saclibrarystudies/chapter/field-trip-and-discussion-board-assignment-exploring-your-local-library/
ALaYjsUnMIscVnjz	American Government (3e)	18 Interpreting the Bill of Rights LEARNING OBJECTIVES By the end of this section, you will be able to: - Describe how the Ninth and Tenth Amendments reflect on our other rights - Identify the two senses of the “right to privacy” embodied in the Constitution - Explain the controversy over privacy when applied to abortion and same-sex relationships As this chapter has suggested, the provisions of the Bill of Rights have been interpreted and reinterpreted repeatedly over the past two centuries. However, the first eight amendments are largely silent on the status of traditional common law, which was the legal basis for many of the natural rights claimed by the framers in the Declaration of Independence. These amendments largely reflect the worldview of the time in which they were written. New technology, societal norms, and economic realities furnish challenges that fail to fit neatly into the framework established in the late eighteenth century. In this section, we consider the final two amendments of the Bill of Rights and the way they affect our understanding of the Constitution as a whole. Rather than protecting specific rights and liberties, the Ninth and Tenth Amendments indicate how the Constitution and the Bill of Rights should be interpreted, and lay out the residual powers of the state governments. We will also examine privacy rights, an area the Bill of Rights does not address directly. Rather, the emergence of defined privacy rights demonstrates how the Ninth and Tenth Amendments have been applied to expand the scope of rights protected by the Constitution. THE NINTH AMENDMENT We saw above that James Madison and the other framers were aware they might endanger some rights if they listed a few in the Constitution and omitted others. To ensure that those interpreting the Constitution would recognize that the listing of freedoms and rights in the Bill of Rights was not exhaustive, the Ninth Amendmentstates: “The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.” These rights “retained by the people” include the common-law and natural rights inherited from the laws, traditions, and past court decisions of England. To this day, we regularly exercise and take for granted rights that aren’t written down in the federal constitution, like the right to marry, the right to seek opportunities for employment and education, and the right to have children and raise a family. Supreme Court justices over the years have interpreted the Ninth Amendment in different ways, with some arguing that it was intended to extend the rights protected by the Constitution to those natural and common-law rights and others arguing that it does not prohibit states from changing their constitutions and laws to modify or limit those rights as they see fit. Critics of a broad interpretation of the Ninth Amendment point out that the Constitution provides ways to protect newly formalized rights through the amendment process. For example, in the nineteenth and twentieth centuries, the right to vote was gradually expanded by a series of constitutional amendments (the Fifteenth and Nineteenth), even though at times this expansion was the subject of great public controversy. However, supporters of a broad interpretation of the Ninth Amendment point out that the rights of the people—particularly people belonging to political or demographic minorities—should not be subject to the whims of popular majorities. One right the courts have said may be at least partially based on the Ninth Amendment is a general right to privacy, discussed later in the chapter. THE TENTH AMENDMENT The Tenth Amendment is as follows: “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.” Unlike the other provisions of the Bill of Rights, this amendment focuses on power rather than rights. The courts have generally read the Tenth Amendment as merely stating, as Chief Justice Harlan Stone put it, a “truism that all is retained which has not been surrendered.”64 In other words, rather than limiting the power of the federal government in any meaningful way, it simply restates what is made obvious elsewhere in the Constitution: the federal government has both enumerated and implied powers, but where the federal government does not (or chooses not to) exercise power, the states may do so. Others read this final “or” as capturing the essential question of U.S. political history: do the states who agreed to unite in a federal system remain sovereign, or once united, is it the federal government’s responsibility to protect the power of the people—including against states that might infringe upon them? At times, politicians and state governments have argued that the Tenth Amendment means states can engage in interposition or nullification by blocking federal government laws and actions they deem to exceed the constitutional powers of the national government. But the courts have rarely been sympathetic to these arguments, except when the federal government appears to be directly requiring state and local officials to do something. For example, in 1997 the Supreme Court struck down part of a federal law that required state and local law enforcement to participate in conducting background checks for prospective gun purchasers, while in 2012 the court ruled that the government could not compel states to participate in expanding the joint state-federal Medicaid program by taking away all their existing Medicaid funding if they refused to do so.65 However, the Tenth Amendment also allows states to guarantee rights and liberties more fully or extensively than the federal government does, or to include additional rights. For example, many state constitutions guarantee the right to a free public education, several states give victims of crimes certain rights, and eighteen states include the right to hunt game and/or fish.66 A number of state constitutions explicitly guarantee equal rights for men and women. Starting with Wyoming in 1869, some some states permitted women to vote before the Nineteenth Amendment secured the franchise for all women in 1920. Similarly, people aged 18–20 could vote in a few states before the Twenty-Sixth Amendment came into force in 1971. As we will see below, several states also explicitly recognize a right to privacy. State courts at times have interpreted state constitutional provisions to include broader protections for basic liberties than their federal counterparts. For example, though people do not generally have the right to free speech and assembly on private property owned by others without their permission, California’s constitutional protection of freedom of expression was extended to portions of some privately owned shopping centers by the state’s supreme court (Figure 4.18).67 These state protections do not extend the other way, however. If the federal government passes a law or adopts a constitutional amendment that restricts rights or liberties, or a Supreme Court decision interprets the Constitution in a way that narrows these rights, the state’s protection no longer applies. For example, if Congress decided to outlaw hunting and fishing and the Supreme Court decided this law was a valid exercise of federal power, the state constitutional provisions that protect the right to hunt and fish would effectively be meaningless. More concretely, federal laws that control weapons and drugs override state laws and constitutional provisions that otherwise permit them. While federal marijuana policies are not strictly enforced, state-level marijuana policies in Colorado and Washington provide a prominent exception to that clarity. GET CONNECTED! Student-Led Constitutional Change Although the United States has not had a national constitutional convention since 1787, the states have generally been much more willing to revise their constitutions. In 1998, two politicians in Texas decided to do something a little bit different: they enlisted the help of college students at Angelo State University to draft a completely new constitution for the state of Texas, which was then formally proposed to the state legislature.68 Although the proposal failed, it was certainly a valuable learning experience for the students who took part. Each state has a different process for changing its constitution. In some, like California and Mississippi, voters can propose amendments to their state constitution directly, bypassing the state legislature. In others, such as Tennessee and Texas, the state legislature controls the process of initiation. The process can affect the sorts of amendments likely to be considered; it shouldn’t be surprising, for example, that amendments limiting the number of terms legislators can serve in office have been much more common in states where the legislators themselves have no say in whether such provisions are adopted. What rights or liberties do you think ought to be protected by your state constitution that aren’t already? Or would you get rid of some of these protections instead? Find a copy of your current state constitution, read through it, and decide. Then find out what steps would be needed to amend your state’s constitution to make the changes you would like to see. THE RIGHT TO PRIVACY Although the term privacy does not appear in the Constitution or Bill of Rights, scholars have interpreted several Bill of Rights provisions as an indication that James Madison and Congress sought to protect a common-law right to privacy as it would have been understood in the late eighteenth century: a right to be free of government intrusion into our personal life, particularly within the bounds of the home. For example, one could see the Second Amendment as standing for the common-law right to self-defense in the home; the Third Amendment as a statement that government soldiers should not be housed in anyone’s home; the Fourth Amendment as setting a high legal standard for allowing agents of the state to intrude on someone’s home; and the due process and takings clauses of the Fifth Amendment as applying an equally high legal standard to the government’s taking a home or property (reinforced after the Civil War by the Fourteenth Amendment). Alternatively, one could argue that the Ninth Amendment anticipated the existence of a common-law right to privacy, among other rights, when it acknowledged the existence of basic, natural rights not listed in the Bill of Rights or the body of the Constitution itself.69 Lawyers Samuel D. Warren and Louis Brandeis (the latter a future Supreme Court justice) famously developed the concept of privacy rights in a law review article published in 1890.70 Although several state constitutions do list the right to privacy as a protected right, the explicit recognition by the Supreme Court of a right to privacy in the U.S. Constitution emerged only in the middle of the twentieth century. In 1965, the court spelled out the right to privacy for the first time in Griswold v. Connecticut, a case that struck down a state law forbidding even married individuals to use any form of contraception.71 Although many subsequent cases before the Supreme Court also dealt with privacy in the course of intimate, sexual conduct, the issue of privacy matters as well in the context of surveillance and monitoring by government and private parties of our activities, movements, and communications. Both these senses of privacy are examined below. Sexual Privacy Although the Griswold case originally pertained only to married couples, in 1972 it was extended to apply the right to obtain contraception to unmarried people as well.72 Although neither decision was entirely without controversy, the “sexual revolution” taking place at the time may well have contributed to a sense that anti-contraception laws were at the very least dated, if not in violation of people’s rights. The contraceptive coverage controversy surrounding the Hobby Lobby case shows that this topic remains relevant. The Supreme Court’s application of the right to privacy doctrine to abortion rights proved far more problematic, legally and politically. In 1972, four states permitted abortions without restrictions, while thirteen allowed abortions “if the pregnant woman’s life or physical or mental health were endangered, if the fetus would be born with a severe physical or mental defect, or if the pregnancy had resulted from rape or incest”; abortions were completely illegal in Pennsylvania and heavily restricted in the remaining states.73 On average, several hundred American women a year died as a result of “back alley abortions” in the 1960s. The legal landscape changed dramatically as a result of the 1973 ruling in Roe v. Wade,74 in which the Supreme Court decided the right to privacy encompassed a right for women to terminate a pregnancy, at least under certain scenarios. The justices ruled that while the government did have an interest in protecting the “potentiality of human life,” nonetheless this had to be balanced against the interests of both women’s health and women’s right to decide whether to have an abortion. Accordingly, the court established a framework for deciding whether abortions could be regulated based on the fetus’s viability (i.e., potential to survive outside the womb) and the stage of pregnancy, with no restrictions permissible during the first three months of pregnancy (i.e., the first trimester), during which abortions were deemed safer for women than childbirth itself. Starting in the 1980s, Supreme Court justices appointed by Republican presidents began to roll back the Roedecision. A key turning point was the court’s ruling in Planned Parenthood v. Casey in 1992, in which a plurality of the court rejected Roe’s framework based on trimesters of pregnancy and replaced it with the undue burden test, which allows restrictions prior to viability that are not “substantial obstacle[s]” (undue burdens) to women seeking an abortion.75 Thus, the court upheld some state restrictions, including a required waiting period between arranging and having an abortion, parental consent (or, if not possible for some reason such as incest, authorization of a judge) for minors, and the requirement that women be informed of the health consequences of having an abortion. Other restrictions such as a requirement that a married woman notify her spouse prior to an abortion were struck down as an undue burden. Since the Casey decision, many states have passed other restrictions on abortions, such as banning certain procedures, requiring women to have and view an ultrasound before having an abortion, and implementing more stringent licensing and inspection requirements for facilities where abortions are performed. In Whole Woman’s Health v. Hellerstedt (2016), the Court reinforced Roe 5–3 by disallowing two Texas state regulations regarding the delivery of abortion services.76 And the 2022 Dobbs v. Jackson Women’s Health Organization decision, the Supreme Court ruled that abortion is not a right and that states had power to pass laws restricting abortion—overruling Roe v. Wade. The decision did not make abortion illegal, but some states were able to begin enforcing existing abortion bans (that had been on hold based on legal challenges) while other states immediately took action to enact new abortion bans. Beyond the issues of contraception and abortion, the right to privacy has been interpreted to encompass a more general right for adults to have noncommercial, consensual sexual relationships in private. However, this legal development is relatively new; as recently as 1986, the Supreme Court ruled that states could still criminalize sex acts between two people of the same sex.77 That decision was overturned in 2003 in Lawrence v. Texas, which invalidated state laws that criminalized sodomy.78 The state and national governments still have leeway to regulate sexual morality to some degree; “anything goes” is not the law of the land, even for actions that are consensual. The Supreme Court has declined to strike down laws in a few states that outlaw the sale of vibrators and other sex toys. Prostitution remains illegal in every state except in certain rural counties in Nevada; both polygamy (marriage to more than one other person) and bestiality (sex with animals) are illegal everywhere. And, as we saw earlier, the states may regulate obscene materials and, in certain situations, material that may be harmful to minors or otherwise indecent; to this end, states and localities have sought to ban or regulate the production, distribution, and sale of pornography. Privacy of Communications and Property Another example of heightened concerns about privacy in the modern era is the reality that society is under pervasive surveillance. In the past, monitoring the public was difficult at best. During the Cold War, regimes in the Soviet bloc employed millions of people as domestic spies and informants in an effort to suppress internal dissent through constant monitoring of the general public. Not only was this effort extremely expensive in terms of the human and monetary capital it required, but it also proved remarkably ineffective. Groups like the East German Stasi and the Romanian Securitate were unable to suppress the popular uprisings that undermined communist one-party rule in most of those countries in the late 1980s. Technology has now made it much easier to track and monitor people. Police cars and roadways are equipped with cameras that can photograph the license plate of every passing car or truck and record it in a database; while allowing police to recover stolen vehicles and catch fleeing suspects, this data can also be used to track the movements of law-abiding citizens. But law enforcement officials don’t even have to go to this much work; millions of car and truck drivers pay tolls electronically without stopping at toll booths thanks to transponders attached to their vehicles, which can be read by scanners well away from any toll road or bridge to monitor traffic flow or any other purpose (Figure 4.20). The pervasive use of GPS (Global Positioning System) raises similar issues. Even pedestrians and cyclists are relatively easy to track today. Cameras pointed at sidewalks and roadways can employ facial recognition software to identify people as they walk or bike around a city. Many people carry smartphones that constantly report their location to the nearest cell phone tower and broadcast a beacon signal to nearby wireless hotspots and Bluetooth devices. Police can set up a small device called a Stingray that identifies and tracks all cell phones that attempt to connect to it within a radius of several thousand feet. With the right software, law enforcement and criminals can remotely activate a phone’s microphone and camera, effectively planting a bug in someone’s pocket without the person even knowing it. These aren’t just gimmicks in a bad science fiction movie; businesses and governments have openly admitted they are using these methods. Research shows that even metadata—information about the messages we send and the calls we make and receive, such as time, location, sender, and recipient but excluding their content—can tell governments and businesses a lot about what someone is doing. Even when this information is collected in an anonymous way, it is often still possible to trace it back to specific individuals, since people travel and communicate in largely predictable patterns. The next frontier of privacy issues may well be the increased use of drones, small preprogrammed or remotely piloted aircraft. Drones can fly virtually undetected and monitor events from overhead. They can peek into backyards surrounded by fences, and using infrared cameras they can monitor activity inside houses and other buildings. The Fourth Amendment was written in an era when finding out what was going on in someone’s home meant either going inside or peeking through a window; applying its protections today, when seeing into someone’s house can be as easy as looking at a computer screen miles away, is no longer simple. In the United States, many advocates of civil liberties are concerned that laws such as the USA PATRIOT Act(i.e., Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act), passed weeks after the 9/11 attacks in 2001, have given the federal government too much power by making it easy for officials to seek and obtain search warrants or, in some cases, to bypass warrant requirements altogether. Critics have argued that the Patriot Act has largely been used to prosecute ordinary criminals, in particular drug dealers, rather than terrorists as intended. Most European countries, at least on paper, have opted for laws that protect against such government surveillance, perhaps mindful of past experience with communist and fascist regimes. European countries also tend to have stricter laws limiting the collection, retention, and use of private data by companies, which makes it harder for governments to obtain and use that data. Most recently, the battle between Apple Inc. and the National Security Agency (NSA) over whether Apple should allow the government access to key information that is encrypted has made the discussion of this tradeoff salient once again. A recent court outcome in the United States suggests that America may follow Europe’s lead. In Carpenter v. United States (2018), the first case of its kind, the U.S. Supreme Court ruled that, under the Fourth Amendment, police need a search warrant to gather phone location data as evidence to be used in trials.79 LINK TO LEARNING Several groups lobby the government, such as The Electronic Frontier Foundation and The Electronic Privacy Information Center, on issues related to privacy in the information age, particularly on the Internet. All this is not to say that technological surveillance tools do not have value or are inherently bad. They can be used for many purposes that would benefit society and, perhaps, even enhance our freedoms. Spending less time stuck in traffic because we know there’s been an accident—detected automatically because the cell phones that normally whiz by at the speed limit are now crawling along—gives us time to spend on more valuable activities. Capturing criminals and terrorists by recognizing them or their vehicles before they can continue their agendas will protect the life, liberty, and property of the public at large. At the same time, however, the emergence of these technologies means calls for vigilance and limits on what businesses and governments can do with the information they collect and the length of time they may retain it. We might also be concerned about how this technology could be used by more oppressive regimes. If the technological resources that are at the disposal of today’s governments had been available to the East Germany Stasi and the Romanian Securitate, would those repressive regimes have fallen? How much privacy and freedom should citizens sacrifice in order to feel safe?	4,793	common-pile/pressbooks_filtered	https://openwa.pressbooks.pub/americangovscc/chapter/interpreting-the-bill-of-rights/	pressbooks	pressbooks-0000.json.gz:94688	https://openwa.pressbooks.pub/americangovscc/chapter/interpreting-the-bill-of-rights/
2UDjsFNFros-Xhli	Hymns and Spiritual Songs	E. E. Hewitt SING the wondrous love of Jesus, Sing His mercy and His grace; In the mansions bright and blessed He’ll prepare for us a place. When we all get to heaven, What a day of rejoicing that will be! When we all see Jesus, We’ll sing and shout the victory. 2 While we walk the pilgrim pathway Clouds will overspread the sky; But when travelling days are over, Not a shadow, not a sigh. 3 Let us then be true and faithful, Trusting, serving every day; Just one glimpse of Him in glory Will the toils of life repay. 4 Onward to the prize before us! Soon His beauty we’ll behold; Soon the pearly gates will open, We shall tread the streets of gold.	163	common-pile/pressbooks_filtered	https://pressbooks.pub/hymnbook/chapter/sing-the-wondrous-love-of-jesus/	pressbooks	pressbooks-0000.json.gz:96404	https://pressbooks.pub/hymnbook/chapter/sing-the-wondrous-love-of-jesus/
sBBZ6BX9YsxYwh09	Introduction to Sociology Lumen/OpenStax	Discussion: Work and the Economy This discussion can be found in Google Docs: Introduction to Sociology Discussion: Work and the Economy To make your own copy to edit: - If you want a Google Doc: in the file menu of the open document, click “Make a copy.” This will give you your own Google Doc to work from. - If you want a PDF or Word file: in the file menu of the open document, click “Download” and select the file type you would like to have (note: depending on the file type you select, the formatting could get jumbled). - Instructions for faculty to paste the content into their LMS are located in the course resource pages.	153	common-pile/pressbooks_filtered	https://pressbooks.nscc.ca/lumensociology2/chapter/discussion-work-and-the-economy-need/	pressbooks	pressbooks-0000.json.gz:66010	https://pressbooks.nscc.ca/lumensociology2/chapter/discussion-work-and-the-economy-need/
oRWko6XQmyDwnE6B	16.4: Chapter 4 Continued Learning	16.4: Chapter 4 Continued Learning The videos below provide an opportunity to expand on your learning from the chapter. As you watch the video, make a list of what you notice and what you wonder. This is a great strategy to listen purposefully, engage with the content, and look for deeper opportunities for self growth, self-reflection, and learning. What do you notice ? - How does this topic support, expand, or challenge the content in the chapter? - How does this topic connect to health topics from other chapters? - How does this topic connect with your prior learning, your experiences, your work, your family, or your life in general? - How does this topic help you to more fully understand health and wellness? What do you wonder ? - How has this topic sparked your curiosity? - What would you like to know more about? - What questions did you have as you reviewed the topic? - What other popular and scholarly sources support or refute this topic? Videos for continued learning and application Note: These videos are intended to more fully reflect on health. You might agree or disagree with the videos and that is ok! Utilize these videos to critically think through the topics and identify other sources, both scholarly and popular, to convey your learning. 3 ways community creates a healthy life Enough with the fear of fat Food revolutionarie Henna-Maria Uusitupa: How the gut microbes you’re born with affect your lifelong health How an obese town lost a million pounds Is the obesity crisis hiding a bigger problem? Obesity + hunger = 1 global food issue Teach every child about food The brain science of obesity The inaccurate link between body ideals and health What is obesity? Why are eating disorders so hard to treat?	390	common-pile/libretexts_filtered	https://med.libretexts.org/Bookshelves/Health_and_Fitness/Introduction_to_Health_2e_(Falcone)/16%3A_Continued_Learning/16.04%3A_Chapter_4_Continued_Learning	libretexts	libretexts-0000.json.gz:20933	https://med.libretexts.org/Bookshelves/Health_and_Fitness/Introduction_to_Health_2e_(Falcone)/16%3A_Continued_Learning/16.04%3A_Chapter_4_Continued_Learning
MdzlBVo1lzBKsbhe	3.E: Trigonometric Identities and Equations (Exercises)	3.E: Trigonometric Identities and Equations (Exercises) 3.1: Solving Trigonometric Equations with Identities In this section, we will begin an examination of the fundamental trigonometric identities, including how we can verify them and how we can use them to simplify trigonometric expressions. Verbal 1) We know $g(x)=\cos x$ is an even function, and $f(x)=\sin x$ and $h(x)=\tan x$are odd functions. What about $G(x)=\cos ^2 x$, $F(x)=\sin ^2 x$ and $H(x)=\tan ^2 x$? Are they even, odd, or neither? Why? - Answer - All three functions, $F,G,$ and $H$ are even. This is because $F(-x)=\sin(-x)\sin(-x)=(-\sin x)(-\sin x)=\sin^2 x=F(x),G(-x)=\cos(-x)\cos(-x)=\cos x\cos x= cos^2 x=H(-x)=\tan(-x)\tan(-x)=(-\tan x)(-\tan x)=\tan2x=H(x)$ 2) Examine the graph of $f(x)=\sec x$ on the interval $[-\pi ,\pi ]$ How can we tell whether the function is even or odd by only observing the graph of $f(x)=\sec x$? 3) After examining the reciprocal identity for $\sec t$ explain why the function is undefined at certain points. - Answer - When $\cos t = 0$ then $\sec t = 10$ which is undefined. 4) All of the Pythagorean identities are related. Describe how to manipulate the equations to get from $\sin^2t+\cos^2t=1$ to the other forms. Algebraic For the exercises 5-15, use the fundamental identities to fully simplify the expression. 5) $\sin x \cos x \sec x$ - Answer - $\sin x$ 6) $\sin(-x)\cos(-x)\csc(-x)$ 7) $\tan x\sin x+\sec x\cos^2x$ - Answer - $\sec x$ 8) $\csc x+\cos x\cot(-x)$ 9) $\dfrac{\cot t+\tan t}{\sec (-t)}$ - Answer - $\csc x$ 10) $3\sin^3 t\csc t+\cos^2 t+2\cos(-t)\cos t$ 11) $-\tan(-x)\cot(-x)$ - Answer - $-1$ 12) $\dfrac{-\sin (-x)\cos x\sec x\csc x\tan x}{\cot x}$ 13) $\dfrac{1+\tan ^2\theta }{\csc ^2\theta }+\sin ^2\theta +\dfrac{1}{\sec ^\theta }$ - Answer - $\sec^2 x$ 14) $\left (\dfrac{\tan x}{\csc ^2 x}+\dfrac{\tan x}{\sec ^2 x} \right )\left (\dfrac{1+\tan x}{1+\cot x} \right )-\dfrac{1}{\cos ^2 x}$ 15) $\dfrac{1-\cos ^2 x}{\tan ^2 x}+2\sin ^2 x$ - Answer - $\sin^2 x+1$ For the exercises 16-28, simplify the first trigonometric expression by writing the simplified form in terms of the second expression. 16) $\dfrac{\tan x+\cot x}{\csc x}; \cos x$ 17) $\dfrac{\sec x+\csc x}{1+\tan x}; \sin x$ - Answer - $\dfrac{1}{\sin x}$ 18) $\dfrac{\cos x}{1+\sin x}+\tan x; \cos x$ 19) $\dfrac{1}{\sin x\cos x}-\cot x; \cot x$ - Answer - $\dfrac{1}{\cot x}$ 20) $\dfrac{1}{1-\cos x}-\dfrac{\cos x}{1+\cos x}; \csc x$ 21) $(\sec x+\csc x)(\sin x+\cos x)-2-\cot x; \tan x$ - Answer - $\tan x$ 22) $\dfrac{1}{\csc x-\sin x}; \sec x$ and $\tan x$ 23) $\dfrac{1-\sin x}{1+\sin x}-\dfrac{1+\sin x}{1-\sin x}; \sec x$ and $\tan x$ - Answer - $-4\sec x \tan x$ 24) $\tan x; \sec x$ 25) $\sec x; \cot x$ - Answer - $\pm \sqrt{\dfrac{1}{\cot ^2 x}+1}$ 26) $\sec x; \sin x$ 27) $\cot x; \sin x$ - Answer - $\dfrac{\pm \sqrt{1-\sin ^2 x}}{\sin x}$ 28) $\cot x; \csc x$ For the exercises 29-33, verify the identity. 29) $\cos x-\cos^3x=\cos x \sin^2 x$ - Answer - Answers will vary. Sample proof: $\begin{align} \cos x-\cos^3x &= \cos x (1-\cos^2 x)\\ &= \cos x\sin ^x \end{align}$ 30) $\cos x(\tan x-\sec(-x))=\sin x-1$ 31) $\dfrac{1+\sin ^2x}{\cos ^2 x}=\dfrac{1}{\cos ^2 x}+\dfrac{\sin ^2x}{\cos ^2 x}=1+2\tan ^2x$ - Answer - Answers will vary. Sample proof: $\begin{align} \dfrac{1+\sin ^2x}{\cos ^2 x} &= \dfrac{1}{\cos ^2 x}+\dfrac{\sin ^2x}{\cos ^2 x}\\ &= \sec ^2x+\tan ^2x\\ &= \tan ^2x+1+\tan ^2x\\ &= 1+2\tan ^2x \end{align}$ 32) $(\sin x+\cos x)^2=1+2 \sin x\cos x$ 33) $\cos^2x-\tan^2x=2-\sin^2x-\sec^2x$ - Answer - Answers will vary. Sample proof: $\begin{align} \cos^2x-\tan^2x &= 1-\sin^2x-\left (\sec^2x -1 \right )\\ &= 1-\sin^2x-\sec^2x +1\\ &= 2-\sin^2x-\sec^2x \end{align}$ Extensions For the exercises 34-39, prove or disprove the identity. 34) $\dfrac{1}{1+\cos x}-\dfrac{1}{1-\cos (-x)}=-2\cot x\csc x$ 35) $\csc^2x(1+\sin^2x)=\cot^2x$ - Answer - False 36) $\left (\dfrac{\sec ^2(-x)-\tan ^2x}{\tan x} \right )\left (\dfrac{2+2\tan x}{2+2\cot x} \right )-2\sin ^2x=\cos 2x$ 37) $\dfrac{\tan x}{\sec x}\sin (-x)=\cos ^2x$ - Answer - False 38) $\dfrac{\sec (-x)}{\tan x+\cot x}=-\sin (-x)$ 39) $\dfrac{1+\sin x}{\cos x}=\dfrac{\cos x}{1+\sin (-x)}$ - Answer - Proved with negative and Pythagorean identities For the exercises 40-, determine whether the identity is true or false. If false, find an appropriate equivalent expression. 40) $\dfrac{\cos ^2 \theta -\sin ^2 \theta }{1-\tan ^\theta }=\sin ^2 \theta$ 41) $3\sin^2\theta + 4\cos^2\theta =3+\cos^2\theta$ - Answer - True $\begin{align} 3\sin^2\theta + 4\cos^2\theta &= 3\sin ^2\theta +3\cos ^2\theta +\cos^2\theta \\ &= 3\left ( \sin ^2\theta +\cos ^2\theta \right )+\cos^2\theta \\ &= 3+\cos^2\theta \end{align}$ 42) $\dfrac{\sec \theta +\tan \theta }{\cot \theta+\cos ^\theta }=\sec ^2 \theta$ 3.2: Sum and Difference Identities In this section, we will learn techniques that will enable us to solve useful problems. The formulas that follow will simplify many trigonometric expressions and equations. Keep in mind that, throughout this section, the term formula is used synonymously with the word identity. Verbal 1) Explain the basis for the cofunction identities and when they apply. - Answer - The cofunction identities apply to complementary angles. Viewing the two acute angles of a right triangle, if one of those angles measures $x$ the second angle measures $\dfrac{\pi }{2}-x$ Then $\sin x=\cos \left (\dfrac{\pi }{2}-x \right )$ The same holds for the other cofunction identities. The key is that the angles are complementary. 2) Is there only one way to evaluate $\cos \left (\dfrac{5\pi }{4} \right )$ Explain how to set up the solution in two different ways, and then compute to make sure they give the same answer. 3) Explain to someone who has forgotten the even-odd properties of sinusoidal functions how the addition and subtraction formulas can determine this characteristic for $f(x)=\sin (x)$ and $g(x)=\cos (x)$ (Hint: $0-x=-x$) - Answer - $\sin (-x)=-\sin x$, so $\sin x$ is odd. $\cos (-x)=\cos (0-x)=\cos x$, so $\cos x$ is even. Algebraic For the exercises 4-9, find the exact value. 4) $\cos \left (\dfrac{7\pi }{12} \right)$ 5) $\cos \left (\dfrac{\pi }{12} \right)$ - Answer - $\dfrac{\sqrt{2}+\sqrt{6}}{4}$ 6) $\sin \left (\dfrac{5\pi }{12} \right)$ 7) $\sin \left (\dfrac{11\pi }{12} \right)$ - Answer - $\dfrac{\sqrt{6}-\sqrt{2}}{4}$ 8) $\tan \left (-\dfrac{\pi }{12} \right)$ 9) $\tan \left (\dfrac{19\pi }{12} \right)$ - Answer - $-2-\sqrt{3}$ For the exercises 10-13, rewrite in terms of $\sin x$ and $\cos x$ 10) $\sin \left (x+\dfrac{11\pi }{6} \right)$ 11) $\sin \left (x-\dfrac{3\pi }{4} \right)$ - Answer - $-\dfrac{\sqrt{2}}{2}\sin x-\dfrac{\sqrt{2}}{2}\cos x$ 12) $\cos \left (x-\dfrac{5\pi }{6} \right)$ 13) $\cos \left (x+\dfrac{2\pi }{3} \right)$ - Answer - $-\dfrac{1}{2}\cos x-\dfrac{\sqrt{3}}{2}\sin x$ For the exercises 14-19, simplify the given expression. 14) $\csc \left (\dfrac{\pi }{2}-t \right)$ 15) $\sec \left (\dfrac{\pi }{2}-\theta \right)$ - Answer - $\csc \theta$ 16) $\cot \left (\dfrac{\pi }{2}-x \right)$ 17) $\tan \left (\dfrac{\pi }{2}-x \right)$ - Answer - $\cot x$ 18) $\sin(2x)\cos(5x)-\sin(5x)\cos(2x)$ 19) $\dfrac{\tan \left (\dfrac{3}{2}x \right)-\tan \left (\dfrac{7}{5}x \right)}{1+\tan \left (\dfrac{3}{2}x \right)\tan \left (\dfrac{7}{5}x \right)}$ - Answer - $\tan \left (\dfrac{x}{10} \right)$ For the exercises 20-21, find the requested information. 20) Given that $\sin a=\dfrac{2}{3}$ and $\cos b=-\dfrac{1}{4}$ with $a$ and $b$ both in the interval $\left [ \dfrac{\pi }{2}, \pi \right )$ find $\sin (a+b)$ and $\cos (a-b)$. 21) Given that $\sin a=\dfrac{4}{5}$ and $\cos b=\dfrac{1}{3}$, with $a$ and $b$ both in the interval $\left [ 0, \dfrac{\pi }{2} \right )$, find $\sin (a-b)$ and $\cos (a+b)$. - Answer - $\sin (a-b)=\left ( \dfrac{4}{5} \right )\left ( \dfrac{1}{3} \right )-\left ( \dfrac{3}{5} \right )\left ( \dfrac{2\sqrt{2}}{3} \right )=\dfrac{4-6\sqrt{2}}{15}$ $\cos (a+b)=\left ( \dfrac{3}{5} \right )\left ( \dfrac{1}{3} \right )-\left ( \dfrac{4}{5} \right )\left ( \dfrac{2\sqrt{2}}{3} \right )=\dfrac{3-8\sqrt{2}}{15}$ For the exercises 22-24, find the exact value of each expression. 22) $\sin \left ( \cos^{-1}\left ( 0 \right )- \cos^{-1}\left ( \dfrac{1}{2} \right )\right )$ 23) $\cos \left ( \cos^{-1}\left ( \dfrac{\sqrt{2}}{2} \right )+ \sin^{-1}\left ( \dfrac{\sqrt{3}}{2} \right )\right )$ - Answer - $\dfrac{\sqrt{2}-\sqrt{6}}{4}$ 24) $\tan \left ( \sin^{-1}\left ( \dfrac{1}{2} \right )- \cos^{-1}\left ( \dfrac{1}{2} \right )\right )$ Graphical For the exercises 25-32, simplify the expression, and then graph both expressions as functions to verify the graphs are identical. 25) $\cos \left ( \dfrac{\pi }{2}-x \right )$ - Answer - $\sin x$ 26) $\sin (\pi -x)$ 27) $\tan \left ( \dfrac{\pi }{3}+x \right )$ - Answer - $\cot \left ( \dfrac{\pi }{6}-x \right )$ 28) $\sin \left ( \dfrac{\pi }{3}+x \right )$ 29) $\tan \left ( \dfrac{\pi }{4}-x \right )$ - Answer - $\cot \left ( \dfrac{\pi }{4}+x \right )$ 30) $\cos \left ( \dfrac{7\pi }{6}+x \right )$ 31) $\sin \left ( \dfrac{\pi }{4}+x \right )$ - Answer - $\dfrac{\sin x}{\sqrt{2}}+\dfrac{\cos x}{\sqrt{2}}$ 32) $\cos \left ( \dfrac{5\pi }{4}+x \right )$ For the exercises 33-41, use a graph to determine whether the functions are the same or different. If they are the same, show why. If they are different, replace the second function with one that is identical to the first. (Hint: think $2x=x+x$) 33) $f(x)=\sin(4x)-\sin(3x)\cos x, g(x)=\sin x \cos(3x)$ - Answer - They are the same. 34) $f(x)=\cos(4x)+\sin x \sin(3x), g(x)=-\cos x \cos(3x)$ 35) $f(x)=\sin(3x)\cos(6x), g(x)=-\sin(3x)\cos(6x)$ - Answer - They are different, try $g(x)=\sin(9x)-\cos(3x)\sin(6x)$ 36) $f(x)=\sin(4x), g(x)=\sin(5x)\cos x-\cos(5x)\sin x$ 37) $f(x)=\sin(2x), g(x)=2 \sin x \cos x$ - Answer - They are the same. 38) $f(\theta )=\cos(2\theta ), g(\theta )=\cos^2\theta -\sin^2\theta$ 39) $f(\theta )=\tan(2\theta ), g(\theta )=\dfrac{\tan \theta }{1+\tan^2\theta }$ - Answer - They are different, try $g(\theta )=\dfrac{2\tan \theta }{1-\tan^2\theta }$ 40) $f(x)=\sin(3x)\sin x, g(x)=\sin^2(2x)\cos^2x-\cos^2(2x)\sin2x$ 41) $f(x)=\tan(-x), g(x)=\dfrac{\tan x-\tan(2x)}{1-\tan x \tan(2x)}$ - Answer - They are different, try $g(x)=\dfrac{\tan x-\tan(2x)}{1+\tan x \tan(2x)}$ Technology For the exercises 42-46, find the exact value algebraically, and then confirm the answer with a calculator to the fourth decimal point. 42) $\sin (75^{\circ})$ 43) $\sin (195^{\circ})$ - Answer - $-\dfrac{\sqrt{3}-1}{2\sqrt{2}}$, or $-0.2588$ 44) $\cos (165^{\circ})$ 45) $\cos (345^{\circ})$ - Answer - $\dfrac{1+\sqrt{3}}{2\sqrt{2}}$, or $-0.9659$ 46) $\tan (-15^{\circ})$ Extensions For the exercises 47-51, prove the identities provided. 47) $\tan \left ( x+\dfrac{\pi }{4} \right )=\dfrac{\tan x+1}{1-\tan x}$ - Answer - $\begin{align} \tan \left ( x+\dfrac{\pi }{4} \right ) &= \\ \dfrac{\tan x + \tan\left (\tfrac{\pi}{4} \right )}{1-\tan x \tan\left (\tfrac{\pi}{4} \right )} &= \\ \dfrac{\tan x+1}{1-\tan x(1)} &= \dfrac{\tan x+1}{1-\tan x} \end{align}$ 48) $\dfrac{\tan (a+b)}{\tan (a-b)}=\dfrac{\sin a \cos a + \sin b \cos b}{\sin a \cos a - \sin b \cos b}$ 49) $\dfrac{\cos (a+b)}{\cos a \cos b}=1-\tan a \tan b$ - Answer - $\begin{align} \dfrac{\cos (a+b)}{\cos a \cos b} &= \\ \dfrac{\cos a \cos b}{\cos a \cos b}- \dfrac{\sin a \sin b}{\cos a \cos b} &= 1-\tan a \tan b \end{align}$ 50) $\cos(x+y)\cos(x-y)=\cos^2x-\sin^2y$ 51) $\dfrac{\cos(x+h)-\cos(x)}{h}=\cos x\dfrac{\cos h-1}{h}-\sin x \dfrac{\sin h}{h}$ - Answer - $\begin{align} \dfrac{\cos(x+h)-\cos(x)}{h} &= \\ \dfrac{\cos x\cosh - \sin x\sinh -\cos x}{h} &= \\ \dfrac{\cos x(\cosh-1) - \sin x(\sinh-1)}{h} &= \cos x\dfrac{\cos h-1}{h}-\sin x \dfrac{\sin h}{h} \end{align}$ For the exercises 52-, prove or disprove the statements. 52) $\tan (u+v)=\dfrac{\tan u+\tan v}{1-\tan u \tan v}$ 53) $\tan (u-v)=\dfrac{\tan u-\tan v}{1+\tan u \tan v}$ - Answer - True 54) $\dfrac{\tan (x+y)}{1+\tan x \tan x}=\dfrac{\tan x + \tan y}{1-\tan^2 x \tan^2 y}$ 55) If $\alpha ,\beta$ and $\gamma$ are angles in the same triangle, then prove or disprove	2,293	common-pile/libretexts_filtered	https://math.libretexts.org/Courses/Las_Positas_College/Math_39%3A_Trigonometry/03%3A_Trigonometric_Identities_and_Equations/3.E%3A_Trigonometric_Identities_and_Equations_(Exercises)	libretexts	libretexts-0000.json.gz:12555	https://math.libretexts.org/Courses/Las_Positas_College/Math_39%3A_Trigonometry/03%3A_Trigonometric_Identities_and_Equations/3.E%3A_Trigonometric_Identities_and_Equations_(Exercises)
9Owg4s3Iw-_hL423	Facilitating Student Collaboration in Groups and Teams	6 “I do not like my teammates. I want to change teams.” “I cannot work with my team. They did not hand in their part of the paper on time.” “My team members did not contribute at all. I had to do all the work.” “I contributed but they never took me seriously. They just ignored my points of view.” “I wanted to contribute. But they don’t let me. They don’t give me any parts to do.” “They speak so fast. I have a hard time participating. Whenever I tried to say something, I was cut off.” “They never show me any respect.” “They speak their own language. I am excluded all the time.” “Only if my teammates would know how to do team work the way I know it”. (Chao and Purdy, 2017) Group work in the context of an internationalizing university facilitates the development of intercultural skills for both domestic and international students. The KPU 2023 Academic plan includes a mandate to “foster a culturally and globally aware curriculum, being prepared to meet the needs of an international workplace, whether in Canada or internationally”. This mandate, combined with course and program learning outcomes that include intercultural team skills, adds an additional layer to the team development process. Culturally diverse teams support creative thinking and the development of strong solutions, as team members can bring a wider range of experiences and perspectives to the task than is possible on a monocultural team (Tadmor et al., 2012). However, culturally diverse teams can also struggle with miscommunication and misundrestandings that hinder a successful team process. Intercultural teams have the potential to be most successful when intercultural skills are explicitly discussed and scaffolded in the course and project design. Considerations for intercultural teamwork Consider the relationship of intercultural teamwork with your course learning outcomes, and the ways in which the process skills involved in intercultural teams might be evaluated as a part of the group project. Nederveen Pieterse et al., (2013) found that intercultural teams with stronger learning orientations engaged with each other more effectively, whereas a focus on task performance can undermine intercultural communication in teams. In other words, if students are primarily focused on being graded on the product they submit, they may be less motivated to move through the challenging process of building intercultural team relationships. Consider including a process component in the overall assignment grade, for example, a reflective activity on intercultural skills development within the context of the team project. Consider what specific training in intercultural skills might be needed for students. Students may need support in cultivating an intercultural mindset that includes recognition and respect for differences. An intercultural mindset also includes recognition of one’s own biases, and how these impact interactions with others. Students may need support in understanding that the ways in which we communicate, organize time, work with others, and provide feedback may be shaped by prior experiences and culturally-influenced values. In the resources section of this chapter, you will find an example lesson that includes content and learning activities that support students in developing self-reflective, cognitive, and interpersonal skills for working in intercultural teams. Arkoudis et al. (2013) recommend six practices for facilitating intercultural interaction throughout courses; these practices can support students in developing the skills and relationships that will support their success in group projects. - Planning for interaction: Plan for learning activities throughout the course that bring students from diverse backgrounds together. - Creating environments for interaction: Use icebreakers, breakout rooms, and other low-stakes activities to foster intercultural interaction before assigning a larger group project. - Supporting interaction: Set clear expectations for peer interaction, modelling respect for diverse viewpoints and ways of being. - Engaging with subject knowledge: Incorporate tasks within the group project that are specifically designed to draw on learners’ diverse knowledges. - Developing reflexive processes: Support reflection and peer feedback processes. - Fostering communities of learners: Incorporate community building activities throughout the course, for example socially-oriented online forums. Consider students’ present abilities teamwork abilities. Working in an intercultural team is more complex than working in a monocultural team. If intercultural team development is not an outcome of the assignment, monocultural teams might improve student comfort. Consider the rubric below from Chao and Pardy (2017) when evaluating students’ broader competency in teamwork and how it might affect assignment design. This may involve scaffolding team assignments in a single course, or even across courses, to facilitate a structured movement from monocultural to more intentionally culturally diverse teams. Ensure that the assignment design facilitates authentic intercultural collaboration. Many group projects ask students to submit a single report with a single author voice, which may lead to a product-oriented focus, and a “divide and conquer” approach to the assignment. Chao and Pardy (2017) recommend creating assignments that require analysis from multiple perspectives, such as the analysis of a case through the perspective of multiple stakeholders. Another approach is to require the submission of a portfolio with team members submitting various integrated components, rather than a report-style assignment. Provide a team-building activity that facilitates reflection on values and practices that may be influenced by culture. Encourage team members to share their reflections and note similarities and differences; a next step may be for the team to explicitly outline their desired team culture. Build mentoring into the team process. Gunawardena et al. (2019) suggest that intercultural learning communities benefit from mentoring at a variety of levels. Mentors that support the team project can come from within the team, and be external to the team. For example: - As team members share their strengths and skills, they may identify areas in which they can provide peer mentoring to one another internally in the team. - Team members may require technical mentoring early in the process to use their communications and learning technologies well. Connecting with a peer tutor is one strategy for providing technical mentoring external to the team. - Team members may also benefit from pedagogical mentoring, or mentoring on their collaborative strategies. This type of mentoring could be instructor-provided, in scheduled office hour meetings, or achieved by connecting teams with group learning strategist sessions early in their project process. Consider building a reflection session into the course after the group assignment, where students are offered the opportunity to integrate their intercultural learning in the project. Supporting the Process Reid and Garson (2017) provide an example of a scaffolded group work process that enhanced student satisfaction with group work, and positively shifted student attitudes towards intercultural collaborations. Their process includes the following steps, which incorporate the principles discussed above. - Provide an initial orientation session where students identify the characteristics of successful teams. - Ask students to identify key strengths and skills that they can contribute to a team project. - Use information about student strengths to strategically form teams (Reid and Garson allowed students to choose one team member, but otherwise strategically formed the groups). - Use a class session to provide instruction on intercultural communication and working in diverse teams. - Ensure that the assignment grading reflects a focus on process (such as peer evaluation and self reflection). - Conclude the assignment by asking students to reflect on their experience working in a diverse team. Resources to support work in intercultural teams - Preparing to Work in a Diverse Team Example Lesson (PDF \| Word) - Team Culture Development Exercise (for culturally diverse teams) (PDF \| Word) - Suggestions for Building a Cultural Bridge (student Learning Aid) References Arkoudis, S., Watty, K., Baik, C., Yu, X., Borland, H., Chang, S., . . . Pearce, A. (2013). Finding common ground: Enhancing interaction between domestic and international students in higher education. Teaching in Higher Education, 18(3), 222-235. doi:10.1080/13562517.2012.719156 Chao, I. T., & Pardy, M. (2017). Your way or my way? Integrating cultural diversity into team-based learning at Royal Roads University. In S. L. Grundy, D. Hamilton, G. Veletsianos, N. Agger-Gupta, P. Márquez, V. Forssman, & M. Legault (Eds.), Engaging students in life-changing learning: Royal Roads University’s learning and teaching model in practice. Royal Roads University. https://learningandteachingmodel.pressbooks.com/ Gunawardena, C. N., Frechette, C., & Layne, L. (2018). Culturally inclusive instructional design: a framework and guide. Routledge. Nederveen Pieterse, A., Van Kippenberg, D., & Van Dierendonck, D. (2013). Cultural diversity and team performance: The role of team member goal orientation. Academy of Management Journal, 56(3), 782–804. Business Source Complete. Reid, R., & Garson, K. (2017). Rethinking multicultural group work as intercultural learning. Journal of Studies in International Education, 21(3), 195–212. https://doi.org/10.1177/1028315316662981 Tadmor, C. T., Satterstrom, P., Jang, S., & Polzer, J. T. (2012). Beyond individual creativity: The superadditive benefits of multicultural experience for collective creativity in culturally diverse teams. Journal of Cross-Cultural Psychology, 43(3), 384–392. https://doi.org/10.1177/0022022111435259 Attribution Statement: The quotations at the beginning of this chapter, and the Pedagogical Considerations for Diversity in Team Composition are both borrowed without changes from Chao, I. T., & Pardy, M. (2017). Your way or my way? Integrating cultural diversity into team-based learning at Royal Roads University. In S. L. Grundy, D. Hamilton, G. Veletsianos, N. Agger-Gupta, P. Márquez, V. Forssman, & M. Legault (Eds.), Engaging students in life-changing learning: Royal Roads University’s learning and teaching model in practice. Royal Roads University. https://learningandteachingmodel.pressbooks.com/ and used under a CC-BY 4.0 International License.	2,003	common-pile/pressbooks_filtered	https://pressbooks.nscc.ca/groupwork/chapter/facilitate-team-development-in-culturally-diverse-teams/	pressbooks	pressbooks-0000.json.gz:1685	https://pressbooks.nscc.ca/groupwork/chapter/facilitate-team-development-in-culturally-diverse-teams/
GfQNEOCOptaJJH1w	Business Information Skills Certificate (BISC): Research Guide	The Cost of Industry and Market Research Sally Armstrong Research is Expensive and Time-Consuming Conducting industry and market research, whether it is primary or secondary research, can be both expensive and time-consuming. Creating a survey can take quite a bit of time if you are not familiar with how to design one or how to analyze the results you have gathered. As well, purchasing industry reports can be very expensive with a single report costing hundreds if not thousands of dollars. Each year UNB Libraries pays tens of thousands of dollars in subscription costs to be able to provide you with access to top-tier industry and market research databases. It is highly recommended you take advantage of the access you have to these resources as a UNB student. The valuable information they hold can help you get a head start on your due diligence for starting a company. They will also prepare you for using these types of resources in your future career as many companies have subscriptions to these very databases. Below are examples of how much an individual report would cost from Statista, IBISWorld, and BCC Research, if you did not have access to them through the library. Take note of how expensive it can be to purchase an individual report and consider the information privilege you enjoy as a student at UNB. Terms of Use Due to the high cost of industry and market research databases, the database vendors are very protective of the information they provide to their subscribers. The result is very strict terms of use that students, staff, and faculty must follow. The terms of use are as follows: - Our licensing agreements state that access is limited to current students, faculty and staff of the University of New Brunswick. - The information within the databases is for individual, non-commercial, educational and research purposes only. - Reports cannot be shared with individuals outside of the University of New Brunswick. - The information must be analyzed, summarized and combined with research from other sources. - The information must be properly cited. You must be very careful to not share information from the industry and market research databases with individuals outside of UNB. This is also important in a co-op placement or internship situation where you might be working for a company through a UNB program requirement. You are not allowed to share access to the databases with a company or share information with them directly from the databases. Under certain circumstances, depending on the database, you may be allowed analyze, summarize, and combine the information with research from other sources when preparing work for a co-op placement or internship. If you have any questions about the proper use of the industry and market research databases available through the library please reach out to the Business Librarian.	612	common-pile/pressbooks_filtered	https://caul-cbua.pressbooks.pub/businessinforesearchguide/chapter/__unknown__-22/	pressbooks	pressbooks-0000.json.gz:24040	https://caul-cbua.pressbooks.pub/businessinforesearchguide/chapter/__unknown__-22/

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